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Sample records for pathogen-associated molecular pattern

  1. MCL and mincle: C-type lectin receptors that sense damaged self and pathogen associated molecular patterns

    Directory of Open Access Journals (Sweden)

    Mark B Richardson

    2014-06-01

    Full Text Available MCL (macrophage C-type lectin and mincle (macrophage inducible C-type lectin comprise part of an extensive repertoire of pattern recognition receptors with the ability to sense damage associated and pathogen associated molecular patterns. In this review we cover the discovery and molecular characterization of these C-type lectin receptors, and highlight recent advances in the understanding of their roles in orchestrating the response of the immune system to bacterial and fungal infection, and damaged self. We also discuss the identification and structure-activity relationships of activating ligands, particularly trehalose dimycolate (TDM and related mycobacterial glycolipids, which have significant potential in the development of TH1/TH17 vaccination strategies.

  2. Oxidation-specific epitopes are danger-associated molecular patterns recognized by pattern recognition receptors of innate immunity

    DEFF Research Database (Denmark)

    Miller, Yury I; Choi, Soo-Ho; Wiesner, Philipp

    2011-01-01

    are a major target of innate immunity, recognized by a variety of "pattern recognition receptors" (PRRs). By analogy with microbial "pathogen-associated molecular patterns" (PAMPs), we postulate that host-derived, oxidation-specific epitopes can be considered to represent "danger (or damage......)-associated molecular patterns" (DAMPs). We also argue that oxidation-specific epitopes present on apoptotic cells and their cellular debris provided the primary evolutionary pressure for the selection of such PRRs. Furthermore, because many PAMPs on microbes share molecular identity and/or mimicry with oxidation...

  3. Plum pox virus capsid protein suppresses plant pathogen-associated molecular pattern (PAMP)-triggered immunity.

    Science.gov (United States)

    Nicaise, Valerie; Candresse, Thierry

    2017-08-01

    The perception of pathogen-associated molecular patterns (PAMPs) by immune receptors launches defence mechanisms referred to as PAMP-triggered immunity (PTI). Successful pathogens must suppress PTI pathways via the action of effectors to efficiently colonize their hosts. So far, plant PTI has been reported to be active against most classes of pathogens, except viruses, although this defence layer has been hypothesized recently as an active part of antiviral immunity which needs to be suppressed by viruses for infection success. Here, we report that Arabidopsis PTI genes are regulated upon infection by viruses and contribute to plant resistance to Plum pox virus (PPV). Our experiments further show that PPV suppresses two early PTI responses, the oxidative burst and marker gene expression, during Arabidopsis infection. In planta expression of PPV capsid protein (CP) was found to strongly impair these responses in Nicotiana benthamiana and Arabidopsis, revealing its PTI suppressor activity. In summary, we provide the first clear evidence that plant viruses acquired the ability to suppress PTI mechanisms via the action of effectors, highlighting a novel strategy employed by viruses to escape plant defences. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  4. Recognition of damage-associated, nucleic acid-related molecular patterns during inflammation and vaccination

    Directory of Open Access Journals (Sweden)

    Nao eJounai

    2013-01-01

    Full Text Available All mammalian cells are equipped with large numbers of sensors for protection from various sorts of invaders, who, in turn, are equipped with molecules containing pathogen-associated molecular patterns (PAMPs. Once these sensors recognize non-self antigens containing PAMPs, various physiological responses including inflammation are induced to eliminate the pathogens. However, the host sometimes suffers from chronic infection or continuous injuries, resulting in production of self-molecules containing damage-associated molecular patterns (DAMPs. DAMPs are also responsible for the elimination of pathogens, but promiscuous recognition of DAMPs through sensors against PAMPs has been reported. Accumulation of DAMPs leads to massive inflammation and continuous production of DAMPs; that is, a vicious circle leading to the development of autoimmune disease. From a vaccinological point of view, the accurate recognition of both PAMPs and DAMPs is important for vaccine immunogenicity, because vaccine adjuvants are composed of several PAMPs and/or DAMPs, which are also associated with severe adverse events after vaccination. Here, we review as the roles of PAMPs and DAMPs upon infection with pathogens or inflammation, and the sensors responsible for recognizing them, as well as their relationship with the development of autoimmune disease or the immunogenicity of vaccines.

  5. A Broad-Spectrum Infection Diagnostic that Detects Pathogen-Associated Molecular Patterns (PAMPs) in Whole Blood.

    Science.gov (United States)

    Cartwright, Mark; Rottman, Martin; Shapiro, Nathan I; Seiler, Benjamin; Lombardo, Patrick; Gamini, Nazita; Tomolonis, Julie; Watters, Alexander L; Waterhouse, Anna; Leslie, Dan; Bolgen, Dana; Graveline, Amanda; Kang, Joo H; Didar, Tohid; Dimitrakakis, Nikolaos; Cartwright, David; Super, Michael; Ingber, Donald E

    2016-07-01

    Blood cultures, and molecular diagnostic tests that directly detect pathogen DNA in blood, fail to detect bloodstream infections in most infected patients. Thus, there is a need for a rapid test that can diagnose the presence of infection to triage patients, guide therapy, and decrease the incidence of sepsis. An Enzyme-Linked Lectin-Sorbent Assay (ELLecSA) that uses magnetic microbeads coated with an engineered version of the human opsonin, Mannose Binding Lectin, containing the Fc immunoglobulin domain linked to its carbohydrate recognition domain (FcMBL) was developed to quantify pathogen-associated molecular patterns (PAMPs) in whole blood. This assay was tested in rats and pigs to explore whether it can detect infections and monitor disease progression, and in prospectively enrolled, emergency room patients with suspected sepsis. These results were also compared with data obtained from non-infected patients with or without traumatic injuries. The FcMBL ELLecSA was able to detect PAMPS present on, or released by, 85% of clinical isolates representing 47 of 55 different pathogen species, including the most common causes of sepsis. The PAMP assay rapidly (animals, even when blood cultures were negative and bacteriocidal antibiotics were administered. In patients with suspected sepsis, the FcMBL ELLecSA detected infection in 55 of 67 patients with high sensitivity (>81%), specificity (>89%), and diagnostic accuracy of 0·87. It also distinguished infection from trauma-related inflammation in the same patient cohorts with a higher specificity than the clinical sepsis biomarker, C-reactive Protein. The FcMBL ELLecSA-based PAMP assay offers a rapid, simple, sensitive and specific method for diagnosing infections, even when blood cultures are negative and antibiotic therapy has been initiated. It may help to triage patients with suspected systemic infections, and serve as a companion diagnostic to guide administration of emerging dialysis-like sepsis therapies

  6. Associations between pathogen-specific clinical mastitis and somatic cell count patterns

    NARCIS (Netherlands)

    Haas, de Y.; Veerkamp, R.F.; Barkema, H.W.; Gröhn, Y.T.; Schukken, Y.H.

    2004-01-01

    Associations were estimated between pathogen-specific cases of clinical mastitis (CM) and somatic cell count (SCC) patterns based on deviations from the typical curve for SCC during lactation and compared with associations between pathogen-specific CM and lactation average SCC. Data from 274 Dutch

  7. Fungal Innate Immunity Induced by Bacterial Microbe-Associated Molecular Patterns (MAMPs

    Directory of Open Access Journals (Sweden)

    Simon Ipcho

    2016-06-01

    Full Text Available Plants and animals detect bacterial presence through Microbe-Associated Molecular Patterns (MAMPs which induce an innate immune response. The field of fungal–bacterial interaction at the molecular level is still in its infancy and little is known about MAMPs and their detection by fungi. Exposing Fusarium graminearum to bacterial MAMPs led to increased fungal membrane hyperpolarization, a putative defense response, and a range of transcriptional responses. The fungus reacted with a different transcript profile to each of the three tested MAMPs, although a core set of genes related to energy generation, transport, amino acid production, secondary metabolism, and especially iron uptake were detected for all three. Half of the genes related to iron uptake were predicted MirA type transporters that potentially take up bacterial siderophores. These quick responses can be viewed as a preparation for further interactions with beneficial or pathogenic bacteria, and constitute a fungal innate immune response with similarities to those of plants and animals.

  8. Viral capsid is a pathogen-associated molecular pattern in adenovirus keratitis.

    Directory of Open Access Journals (Sweden)

    Ashish V Chintakuntlawar

    2010-04-01

    Full Text Available Human adenovirus (HAdV infection of the human eye, in particular serotypes 8, 19 and 37, induces the formation of corneal subepithelial leukocytic infiltrates. Using a unique mouse model of adenovirus keratitis, we studied the role of various virus-associated molecular patterns in subsequent innate immune responses of resident corneal cells to HAdV-37 infection. We found that neither viral DNA, viral gene expression, or viral replication was necessary for the development of keratitis. In contrast, empty viral capsid induced keratitis and a chemokine profile similar to intact virus. Transfected viral DNA did not induce leukocyte infiltration despite CCL2 expression similar to levels in virus infected corneas. Mice without toll-like receptor 9 (Tlr9 signaling developed clinical keratitis upon HAdV-37 infection similar to wild type mice, although the absolute numbers of activated monocytes in the cornea were less in Tlr9(-/- mice. Virus induced leukocytic infiltrates and chemokine expression in mouse cornea could be blocked by treatment with a peptide containing arginine glycine aspartic acid (RGD. These results demonstrate that adenovirus infection of the cornea induces chemokine expression and subsequent infiltration by leukocytes principally through RGD contact between viral capsid and the host cell, possibly through direct interaction between the viral capsid penton base and host cell integrins.

  9. A Broad-Spectrum Infection Diagnostic that Detects Pathogen-Associated Molecular Patterns (PAMPs) in Whole Blood

    OpenAIRE

    Cartwright, Mark; Rottman, Martin; Shapiro, Nathan I.; Seiler, Benjamin; Lombardo, Patrick; Gamini, Nazita; Tomolonis, Julie; Watters, Alexander L.; Waterhouse, Anna; Leslie, Dan; Bolgen, Dana; Graveline, Amanda; Kang, Joo H.; Didar, Tohid; Dimitrakakis, Nikolaos

    2016-01-01

    Background: Blood cultures, and molecular diagnostic tests that directly detect pathogen DNA in blood, fail to detect bloodstream infections in most infected patients. Thus, there is a need for a rapid test that can diagnose the presence of infection to triage patients, guide therapy, and decrease the incidence of sepsis. Methods: An Enzyme-Linked Lectin-Sorbent Assay (ELLecSA) that uses magnetic microbeads coated with an engineered version of the human opsonin, Mannose Binding Lectin, contai...

  10. CARMA2sh and ULK2 control pathogen-associated molecular patterns recognition in human keratinocytes: psoriasis-linked CARMA2sh mutants escape ULK2 censorship.

    Science.gov (United States)

    Scudiero, Ivan; Mazzone, Pellegrino; D'Andrea, Luca E; Ferravante, Angela; Zotti, Tiziana; Telesio, Gianluca; De Rubis, Gabriele; Reale, Carla; Pizzulo, Maddalena; Muralitharan, Shanmugakonar; Vito, Pasquale; Stilo, Romania

    2017-02-23

    The molecular complexes formed by specific members of the family of CARMA proteins, the CARD domain-containing adapter molecule BCL10 and MALT1 (CBM complex) represent a central hub in regulating activation of the pleiotropic transcription factor NF-κB. Recently, missense mutations in CARMA2sh have been shown to cause psoriasis in a dominant manner and with high penetrancy. Here, we demonstrate that in human keratinocytes CARMA2sh plays an essential role in the signal transduction pathway that connects pathogen-associated molecular patterns recognition to NF-κB activation. We also find that the serine/threonine kinase ULK2 binds to and phosphorylates CARMA2sh, thereby inhibiting its capacity to activate NF-κB by promoting lysosomal degradation of BCL10, which is essential for CARMA2sh-mediated NF-κB signaling. Remarkably, CARMA2sh mutants associated with psoriasis escape ULK2 inhibition. Finally, we show that a peptide blocking CARD-mediated BCL10 interactions reduces the capacity of psoriasis-linked CARMA2sh mutants to activate NF-κB. Our work elucidates a fundamental signaling mechanism operating in human keratinocytes and opens to novel potential tools for the therapeutical treatment of human skin disorders.

  11. Prediction of molecular mimicry candidates in human pathogenic bacteria.

    Science.gov (United States)

    Doxey, Andrew C; McConkey, Brendan J

    2013-08-15

    Molecular mimicry of host proteins is a common strategy adopted by bacterial pathogens to interfere with and exploit host processes. Despite the availability of pathogen genomes, few studies have attempted to predict virulence-associated mimicry relationships directly from genomic sequences. Here, we analyzed the proteomes of 62 pathogenic and 66 non-pathogenic bacterial species, and screened for the top pathogen-specific or pathogen-enriched sequence similarities to human proteins. The screen identified approximately 100 potential mimicry relationships including well-characterized examples among the top-scoring hits (e.g., RalF, internalin, yopH, and others), with about 1/3 of predicted relationships supported by existing literature. Examination of homology to virulence factors, statistically enriched functions, and comparison with literature indicated that the detected mimics target key host structures (e.g., extracellular matrix, ECM) and pathways (e.g., cell adhesion, lipid metabolism, and immune signaling). The top-scoring and most widespread mimicry pattern detected among pathogens consisted of elevated sequence similarities to ECM proteins including collagens and leucine-rich repeat proteins. Unexpectedly, analysis of the pathogen counterparts of these proteins revealed that they have evolved independently in different species of bacterial pathogens from separate repeat amplifications. Thus, our analysis provides evidence for two classes of mimics: complex proteins such as enzymes that have been acquired by eukaryote-to-pathogen horizontal transfer, and simpler repeat proteins that have independently evolved to mimic the host ECM. Ultimately, computational detection of pathogen-specific and pathogen-enriched similarities to host proteins provides insights into potentially novel mimicry-mediated virulence mechanisms of pathogenic bacteria.

  12. Long non-coding RNAs as molecular players in plant defense against pathogens.

    Science.gov (United States)

    Zaynab, Madiha; Fatima, Mahpara; Abbas, Safdar; Umair, Muhammad; Sharif, Yasir; Raza, Muhammad Ammar

    2018-05-31

    Long non-coding RNAs (lncRNAs) has significant role in of gene expression and silencing pathways for several biological processes in eukaryotes. lncRNAs has been reported as key player in remodeling chromatin and genome architecture, RNA stabilization and transcription regulation, including enhancer-associated activity. Host lncRNAs are reckoned as compulsory elements of plant defense. In response to pathogen attack, plants protect themselves with the help of lncRNAs -dependent immune systems in which lncRNAs regulate pathogen-associated molecular patterns (PAMPs) and other effectors. Role of lncRNAs in plant microbe interaction has been studied extensively but regulations of several lncRNAs still need extensive research. In this study we discussed and provide as overview the topical advancements and findings relevant to pathogen attack and plant defense mediated by lncRNAs. It is hoped that lncRNAs would be exploited as a mainstream player to achieve food security by tackling different plant diseases. Copyright © 2018. Published by Elsevier Ltd.

  13. Fungal innate immunity induced by bacterial microbe-associated molecular patterns (MAMPs)

    DEFF Research Database (Denmark)

    Ip Cho, Simon; Sundelin, Thomas; Erbs, Gitte

    2016-01-01

    Plants and animals detect bacterial presence through Microbe-Associated Molecular Patterns (MAMPs) which induce an innate immune response. The field of fungal-bacterial interaction at the molecular level is still in its infancy and little is known about MAMPs and their detection by fungi. Exposin...

  14. Genetic associations for pathogen-specific clinical mastitis and patterns of peaks in somatic cell count

    NARCIS (Netherlands)

    Haas, de Y.; Barkema, H.W.; Schukken, Y.H.; Veerkamp, R.F.

    2003-01-01

    Genetic associations were estimated between pathogen-specific cases of clinical mastitis (CM), lactational average somatic cell score (LACSCS), and patterns of peaks in somatic cell count (SCC) which were based on deviations from the typical lactation curve for SCC. The dataset contained test-day

  15. A novel approach for differentiating pathogenic and non-pathogenic Leptospira based on molecular fingerprinting.

    Science.gov (United States)

    Xiao, Di; Zhang, Cuicai; Zhang, Huifang; Li, Xiuwen; Jiang, Xiugao; Zhang, Jianzhong

    2015-04-24

    Leptospirosis is a worldwide, deadly zoonotic disease. Pathogenic Leptospira causes leptospirosis. The rapid and accurate identification of pathogenic and non-pathogenic Leptospira strains is essential for appropriate therapeutic management and timely intervention for infection control. The molecular fingerprint is a simple and rapid alternative tool for microorganisms identification, which is based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In this study, molecular fingerprint was performed to identify pathogenic strains of Leptospira. Phylogenetic analysis based on 16S rRNA gene sequences was used as the reference method. In addition, a label-free technique was used to reveal the different proteins of pathogenic or non-pathogenic Leptospira. A reference database was constructed using 30 Leptospira strains, including 16 pathogenic strains and 14 non-pathogenic strains. Two super reference spectra that were associated with pathogenicity were established. Overall, 33 Leptospira strains were used for validation, and 32 of 33 Leptospira strains could be identified on the species level and all the 33 could be classified as pathogenic or non-pathogenic. The super reference spectra and the major spectra projection (MSP) dendrogram correctly categorized the Leptospira strains into pathogenic and non-pathogenic groups, which was consistent with the 16S rRNA reference methods. Between the pathogenic and non-pathogenic strains, 108 proteins were differentially expressed. molecular fingerprint is an alternative to conventional molecular identification and can rapidly distinguish between pathogenic and non-pathogenic Leptospira strains. Therefore, molecular fingerprint may play an important role in the clinical diagnosis, treatment, surveillance, and tracking of epidemic outbreaks of leptospirosis. Leptospirosis is a worldwide zoonosis that is caused by spirochetes of the genus Leptospira. Leptospirosis is a serious zoonotic

  16. Plant immunity triggered by engineered in vivo release of oligogalacturonides, damage-associated molecular patterns.

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    Benedetti, Manuel; Pontiggia, Daniela; Raggi, Sara; Cheng, Zhenyu; Scaloni, Flavio; Ferrari, Simone; Ausubel, Frederick M; Cervone, Felice; De Lorenzo, Giulia

    2015-04-28

    Oligogalacturonides (OGs) are fragments of pectin that activate plant innate immunity by functioning as damage-associated molecular patterns (DAMPs). We set out to test the hypothesis that OGs are generated in planta by partial inhibition of pathogen-encoded polygalacturonases (PGs). A gene encoding a fungal PG was fused with a gene encoding a plant polygalacturonase-inhibiting protein (PGIP) and expressed in transgenic Arabidopsis plants. We show that expression of the PGIP-PG chimera results in the in vivo production of OGs that can be detected by mass spectrometric analysis. Transgenic plants expressing the chimera under control of a pathogen-inducible promoter are more resistant to the phytopathogens Botrytis cinerea, Pectobacterium carotovorum, and Pseudomonas syringae. These data provide strong evidence for the hypothesis that OGs released in vivo act as a DAMP signal to trigger plant immunity and suggest that controlled release of these molecules upon infection may be a valuable tool to protect plants against infectious diseases. On the other hand, elevated levels of expression of the chimera cause the accumulation of salicylic acid, reduced growth, and eventually lead to plant death, consistent with the current notion that trade-off occurs between growth and defense.

  17. Microbe-associated molecular pattern (MAMP) signatures, synergy, size and charge

    DEFF Research Database (Denmark)

    Aslam, Shazia N.; Erbs, Gitte; Morrissey, Kate L.

    2009-01-01

    Triggering of defences by microbes has mainly been investigated using single elicitors or microbe-associated molecular patterns (MAMPs), but MAMPs are released in planta as complex mixtures together with endogenous oligogalacturonan (OGA) elicitor. We investigated the early responses in Arabidops...

  18. Dissecting the molecular interactions between wheat and the fungal pathogen Zymoseptoria tritici

    Directory of Open Access Journals (Sweden)

    Graeme James Kettles

    2016-04-01

    Full Text Available The Dothideomycete fungus Zymoseptoria tritici (previously known as Mycosphaerella graminicola and Septoria tritici is the causative agent of Septoria tritici leaf blotch (STB disease of wheat (Triticum aestivum L.. In Europe, STB is the most economically damaging disease of wheat, with an estimated ~€1 billion per year in fungicide expenditure directed towards its control. Here, an overview of our current understanding of the molecular events that occur during Z. tritici infection of wheat leaves is presented. On the host side, this includes the contribution of (1 the pathogen-associated molecular pattern-triggered immunity (PTI layer of the plant defence, and (2 major Stb resistance loci to Z. tritici resistance. On the pathogen side of the interaction, we consolidate evidence from recent bioinformatic, transcriptomic and proteomic studies that begin to explain the contribution of Z. tritici effector proteins to the biphasic lifestyle of the fungus. This includes the discovery of chitin-binding proteins in the Z. tritici secretome, which contribute to evasion of immune surveillance by this pathogen, and the possible existence of ‘necrotrophic’ effectors from Z. tritici, which may actively stimulate host recognition in a manner similar to related necrotrophic fungal pathogens. We finish by speculating on how some of these recent fundamental discoveries might be harnessed to help improve resistance to STB in the world’s second largest food crop.

  19. Molecular detection of human bacterial pathogens

    National Research Council Canada - National Science Library

    Liu, Dongyou

    2011-01-01

    .... Molecular Detection of Human Bacterial Pathogens addresses this issue, with international scientists in respective bacterial pathogen research and diagnosis providing expert summaries on current...

  20. Molecular surveillance of traditional and emerging pathogens associated with canine infectious respiratory disease.

    Science.gov (United States)

    Decaro, Nicola; Mari, Viviana; Larocca, Vittorio; Losurdo, Michele; Lanave, Gianvito; Lucente, Maria Stella; Corrente, Marialaura; Catella, Cristiana; Bo, Stefano; Elia, Gabriella; Torre, Giorgio; Grandolfo, Erika; Martella, Vito; Buonavoglia, Canio

    2016-08-30

    A molecular survey for traditional and emerging pathogens associated with canine infectious respiratory disease (CIRD) was conducted in Italy between 2011 and 2013 on a total of 138 dogs, including 78 early acute clinically ill CIRD animals, 22 non-clinical but exposed to clinically ill CIRD dogs and 38 CIRD convalescent dogs. The results showed that canine parainfluenza virus (CPIV) was the most commonly detected CIRD pathogen, followed by canine respiratory coronavirus (CRCoV), Bordetella bronchiseptica, Mycoplasma cynos, Mycoplasma canis and canine pneumovirus (CnPnV). Some classical CIRD agents, such as canine adenoviruses, canine distemper virus and canid herpesvirus 1, were not detected at all, as were not other emerging respiratory viruses (canine influenza virus, canine hepacivirus) and bacteria (Streptococcus equi subsp. zooepidemicus). Most severe forms of respiratory disease were observed in the presence of CPIV, CRCoV and M. cynos alone or in combination with other pathogens, whereas single CnPnV or M. canis infections were detected in dogs with no or very mild respiratory signs. Interestingly, only the association of M. cynos (alone or in combination with either CRCoV or M. canis) with severe clinical forms was statistically significant. The study, while confirming CPIV as the main responsible for CIRD occurrence, highlights the increasing role of recently discovered viruses, such as CRCoV and CnPnV, for which effective vaccines are not available in the market. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Mitochondrial damage-associated molecular patterns and vascular function†

    Science.gov (United States)

    Wenceslau, Camilla Ferreira; McCarthy, Cameron G.; Szasz, Theodora; Spitler, Kathryn; Goulopoulou, Styliani; Webb, R. Clinton

    2014-01-01

    Immune system activation occurs not only due to foreign stimuli, but also due to endogenous molecules. As such, endogenous molecules that are released into the circulation due to cell death and/or injury alarm the immune system that something has disturbed homeostasis and a response is needed. Collectively, these molecules are known as damage-associated molecular patterns (DAMPs). Mitochondrial DAMPs (mtDAMPs) are potent immunological activators due to the bacterial ancestry of mitochondria. Mitochondrial DAMPs are recognized by specific pattern recognition receptors of the innate immune system, some of which are expressed in the cardiovascular system. Cell death leads to release of mtDAMPs that may induce vascular changes by mechanisms that are currently not well understood. This review will focus on recently published evidence linking mtDAMPs and immune system activation to vascular dysfunction and cardiovascular disease. PMID:24569027

  2. Analysis of Microbe-Associated Molecular Pattern-Responsive Synthetic Promoters with the Parsley Protoplast System.

    Science.gov (United States)

    Kanofsky, Konstantin; Lehmeyer, Mona; Schulze, Jutta; Hehl, Reinhard

    2016-01-01

    Plants recognize pathogens by microbe-associated molecular patterns (MAMPs) and subsequently induce an immune response. The regulation of gene expression during the immune response depends largely on cis-sequences conserved in promoters of MAMP-responsive genes. These cis-sequences can be analyzed by constructing synthetic promoters linked to a reporter gene and by testing these constructs in transient expression systems. Here, the use of the parsley (Petroselinum crispum) protoplast system for analyzing MAMP-responsive synthetic promoters is described. The synthetic promoter consists of four copies of a potential MAMP-responsive cis-sequence cloned upstream of a minimal promoter and the uidA reporter gene. The reporter plasmid contains a second reporter gene, which is constitutively expressed and hence eliminates the requirement of a second plasmid used as a transformation control. The reporter plasmid is transformed into parsley protoplasts that are elicited by the MAMP Pep25. The MAMP responsiveness is validated by comparing the reporter gene activity from MAMP-treated and untreated cells and by normalizing reporter gene activity using the constitutively expressed reporter gene.

  3. Innate immune responses activated in Arabidopsis roots by microbe-associated molecular patterns.

    Science.gov (United States)

    Millet, Yves A; Danna, Cristian H; Clay, Nicole K; Songnuan, Wisuwat; Simon, Matthew D; Werck-Reichhart, Danièle; Ausubel, Frederick M

    2010-03-01

    Despite the fact that roots are the organs most subject to microbial interactions, very little is known about the response of roots to microbe-associated molecular patterns (MAMPs). By monitoring transcriptional activation of beta-glucuronidase reporters and MAMP-elicited callose deposition, we show that three MAMPs, the flagellar peptide Flg22, peptidoglycan, and chitin, trigger a strong tissue-specific response in Arabidopsis thaliana roots, either at the elongation zone for Flg22 and peptidoglycan or in the mature parts of the roots for chitin. Ethylene signaling, the 4-methoxy-indole-3-ylmethylglucosinolate biosynthetic pathway, and the PEN2 myrosinase, but not salicylic acid or jasmonic acid signaling, play major roles in this MAMP response. We also show that Flg22 induces the cytochrome P450 CYP71A12-dependent exudation of the phytoalexin camalexin by Arabidopsis roots. The phytotoxin coronatine, an Ile-jasmonic acid mimic produced by Pseudomonas syringae pathovars, suppresses MAMP-activated responses in the roots. This suppression requires the E3 ubiquitin ligase COI1 as well as the transcription factor JIN1/MYC2 but does not rely on salicylic acid-jasmonic acid antagonism. These experiments demonstrate the presence of highly orchestrated and tissue-specific MAMP responses in roots and potential pathogen-encoded mechanisms to block these MAMP-elicited signaling pathways.

  4. The Top 10 fungal pathogens in molecular plant pathology

    NARCIS (Netherlands)

    Dean, R.; Kan, van J.A.L.; Pretorius, Z.A.; Hammond-Kosack, K.E.; Pietro, Di A.; Spanu, P.D.; Rudd, J.J.; Dickman, M.; Kahmann, R.; Ellis, J.; Foster, G.D.

    2012-01-01

    The aim of this review was to survey all fungal pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate which fungal pathogens they would place in a ‘Top 10’ based on scientific/economic importance. The survey generated 495 votes from the international

  5. Molecular detection of pathogens in water--the pros and cons of molecular techniques.

    Science.gov (United States)

    Girones, Rosina; Ferrús, Maria Antonia; Alonso, José Luis; Rodriguez-Manzano, Jesus; Calgua, Byron; Corrêa, Adriana de Abreu; Hundesa, Ayalkibet; Carratala, Anna; Bofill-Mas, Sílvia

    2010-08-01

    Pollution of water by sewage and run-off from farms produces a serious public health problem in many countries. Viruses, along with bacteria and protozoa in the intestine or in urine are shed and transported through the sewer system. Even in highly industrialized countries, pathogens, including viruses, are prevalent throughout the environment. Molecular methods are used to monitor viral, bacterial, and protozoan pathogens, and to track pathogen- and source-specific markers in the environment. Molecular techniques, specifically polymerase chain reaction-based methods, provide sensitive, rapid, and quantitative analytical tools with which to study such pathogens, including new or emerging strains. These techniques are used to evaluate the microbiological quality of food and water, and to assess the efficiency of virus removal in drinking and wastewater treatment plants. The range of methods available for the application of molecular techniques has increased, and the costs involved have fallen. These developments have allowed the potential standardization and automation of certain techniques. In some cases they facilitate the identification, genotyping, enumeration, viability assessment, and source-tracking of human and animal contamination. Additionally, recent improvements in detection technologies have allowed the simultaneous detection of multiple targets in a single assay. However, the molecular techniques available today and those under development require further refinement in order to be standardized and applicable to a diversity of matrices. Water disinfection treatments may have an effect on the viability of pathogens and the numbers obtained by molecular techniques may overestimate the quantification of infectious microorganisms. The pros and cons of molecular techniques for the detection and quantification of pathogens in water are discussed. (c) 2010 Elsevier Ltd. All rights reserved.

  6. Elucidation of Molecular Pathogenic Mechanisms of Norrie Disease

    OpenAIRE

    Luhmann, Ulrich F.O.

    2010-01-01

    Summary Norrie disease (ND) is a rare X-linked recessive congenital blindness, sometimes associated with deafness and mental retardation. In this thesis the molecular pathogenic mechanisms of this syndrome should be elucidated using the Ndph knockout mouse model. Gene expression studies but also histology and protein biochemistry were used to characterize the affected organs, eye and brain. Gene expression analyses of eyes at p21 using cDNA subtrac...

  7. Molecular epidemiology of mastitis pathogens of dairy cattle and comparative relevance to humans.

    Science.gov (United States)

    Zadoks, Ruth N; Middleton, John R; McDougall, Scott; Katholm, Jorgen; Schukken, Ynte H

    2011-12-01

    Mastitis, inflammation of the mammary gland, can be caused by a wide range of organisms, including gram-negative and gram-positive bacteria, mycoplasmas and algae. Many microbial species that are common causes of bovine mastitis, such as Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae and Staphylococcus aureus also occur as commensals or pathogens of humans whereas other causative species, such as Streptococcus uberis, Streptococcus dysgalactiae subsp. dysgalactiae or Staphylococcus chromogenes, are almost exclusively found in animals. A wide range of molecular typing methods have been used in the past two decades to investigate the epidemiology of bovine mastitis at the subspecies level. These include comparative typing methods that are based on electrophoretic banding patterns, library typing methods that are based on the sequence of selected genes, virulence gene arrays and whole genome sequencing projects. The strain distribution of mastitis pathogens has been investigated within individual animals and across animals, herds, countries and host species, with consideration of the mammary gland, other animal or human body sites, and environmental sources. Molecular epidemiological studies have contributed considerably to our understanding of sources, transmission routes, and prognosis for many bovine mastitis pathogens and to our understanding of mechanisms of host-adaptation and disease causation. In this review, we summarize knowledge gleaned from two decades of molecular epidemiological studies of mastitis pathogens in dairy cattle and discuss aspects of comparative relevance to human medicine.

  8. MAMP (microbe-associated molecular pattern)-induced changes in plasma membrane-associated proteins.

    Science.gov (United States)

    Uhlíková, Hana; Solanský, Martin; Hrdinová, Vendula; Šedo, Ondrej; Kašparovský, Tomáš; Hejátko, Jan; Lochman, Jan

    2017-03-01

    Plant plasma membrane associated proteins play significant roles in Microbe-Associated Molecular Pattern (MAMP) mediated defence responses including signal transduction, membrane transport or energetic metabolism. To elucidate the dynamics of proteins associated with plasma membrane in response to cryptogein, a well-known MAMP of defence reaction secreted by the oomycete Phytophthora cryptogea, 2D-Blue Native/SDS gel electrophoresis of plasma membrane fractions was employed. This approach revealed 21 up- or down-regulated protein spots of which 15 were successfully identified as proteins related to transport through plasma membrane, vesicle trafficking, and metabolic enzymes including cytosolic NADP-malic enzyme and glutamine synthetase. Observed changes in proteins were also confirmed on transcriptional level by qRT-PCR analysis. In addition, a significantly decreased accumulation of transcripts observed after employment of a mutant variant of cryptogein Leu41Phe, exhibiting a conspicuous defect in induction of resistance, sustains the contribution of identified proteins in cryptogein-triggered cellular responses. Our data provide further evidence for dynamic MAMP-induced changes in plasma membrane associated proteins. Copyright © 2016 Elsevier GmbH. All rights reserved.

  9. The toll of the gridiron: damage-associated molecular patterns and hypertension in American football

    Science.gov (United States)

    McCarthy, Cameron G.; Webb, R. Clinton

    2016-01-01

    American football has unequivocally been linked to elevations in blood pressure and hypertension, especially in linemen. However, the mechanisms of this increase cannot be attributed solely to increased body weight and associated cardiometabolic risk factors (e.g.,dyslipidemia or hyperglycemia). Therefore, understanding the etiology of football-associated hypertension is essential for improving the quality of life in this mostly young population, as well as for lowering the potential for chronic disease in the future. We propose that inflammatogenic damage–associated molecular patterns (DAMPs) released into the circulation from football-induced musculoskeletal trauma activate pattern-recognition receptors of the innate immune system—specifically, high mobility group box 1 protein (HMGB1) and mitochondrial (mt)DNA which activate Toll-like receptor (TLR)4 and -9, respectively. Previously, we observed that circulating levels of these 2 DAMPs are increased in hypertension, and activation of TLR4 and -9 causes endothelial dysfunction and hypertension. Therefore, our novel hypothesis is that musculoskeletal injury from repeated hits in football players, particularly in linemen, leads to elevated circulating HMGB1 and mtDNA to activate TLRs on endothelial cells leading to impaired endothelium-dependent vasodilation, increased vascular tone, and hypertension.—McCarthy, C. G., Webb, R. C. The toll of the gridiron: damage-associated molecular patterns and hypertension in American football. PMID:26316270

  10. Molecular Diagnostics for Soilborne Fungal Pathogens

    Directory of Open Access Journals (Sweden)

    E.J. Paplomatas

    2004-08-01

    Full Text Available Several classical approaches have been developed to detect and identify soil fungal inhabitants through the years. Selective media have been devised to exclude the large number of soil organisms and allow growth of target fungi. However the advent of molecular biology has offered a number of revolutionary insights into the detection and enumeration of soilborne fungal pathogens and also has started to provide information on the identification of unknown species from DNA sequences. This review paper focuses on the application of various molecular techniques in the detection, identification, characterization and quantification of soilborne fungal plant pathogens. This is based on information from the literature and is combined with personal research findings of the author.

  11. Pathogenic Leptospira: Advances in understanding the molecular pathogenesis and virulence

    Science.gov (United States)

    Ghazaei, Ciamak

    2018-01-01

    Leptospirosis is a common zoonotic disease has emerged as a major public health problem, with developing countries bearing disproportionate burdens. Although the diverse range of clinical manifestations of the leptospirosis in humans is widely documented, the mechanisms through which the pathogen causes disease remain undetermined. In addition, leptospirosis is a much-neglected life-threatening disease although it is one of the most important zoonoses occurring in a diverse range of epidemiological distribution. Recent advances in molecular profiling of pathogenic species of the genus Leptospira have improved our understanding of the evolutionary factors that determine virulence and mechanisms that the bacteria employ to survive. However, a major impediment to the formulation of intervention strategies has been the limited understanding of the disease determinants. Consequently, the association of the biological mechanisms to the pathogenesis of Leptospira, as well as the functions of numerous essential virulence factors still remain implicit. This review examines recent advances in genetic screening technologies, the underlying microbiological processes, the virulence factors and associated molecular mechanisms driving pathogenesis of Leptospira species. PMID:29445617

  12. The Top 10 fungal pathogens in molecular plant pathology.

    Science.gov (United States)

    Dean, Ralph; Van Kan, Jan A L; Pretorius, Zacharias A; Hammond-Kosack, Kim E; Di Pietro, Antonio; Spanu, Pietro D; Rudd, Jason J; Dickman, Marty; Kahmann, Regine; Ellis, Jeff; Foster, Gary D

    2012-05-01

    The aim of this review was to survey all fungal pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate which fungal pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 495 votes from the international community, and resulted in the generation of a Top 10 fungal plant pathogen list for Molecular Plant Pathology. The Top 10 list includes, in rank order, (1) Magnaporthe oryzae; (2) Botrytis cinerea; (3) Puccinia spp.; (4) Fusarium graminearum; (5) Fusarium oxysporum; (6) Blumeria graminis; (7) Mycosphaerella graminicola; (8) Colletotrichum spp.; (9) Ustilago maydis; (10) Melampsora lini, with honourable mentions for fungi just missing out on the Top 10, including Phakopsora pachyrhizi and Rhizoctonia solani. This article presents a short resumé of each fungus in the Top 10 list and its importance, with the intent of initiating discussion and debate amongst the plant mycology community, as well as laying down a bench-mark. It will be interesting to see in future years how perceptions change and what fungi will comprise any future Top 10. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  13. Top 10 plant pathogenic bacteria in molecular plant pathology.

    Science.gov (United States)

    Mansfield, John; Genin, Stephane; Magori, Shimpei; Citovsky, Vitaly; Sriariyanum, Malinee; Ronald, Pamela; Dow, Max; Verdier, Valérie; Beer, Steven V; Machado, Marcos A; Toth, Ian; Salmond, George; Foster, Gary D

    2012-08-01

    Many plant bacteriologists, if not all, feel that their particular microbe should appear in any list of the most important bacterial plant pathogens. However, to our knowledge, no such list exists. The aim of this review was to survey all bacterial pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate the bacterial pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 458 votes from the international community, and allowed the construction of a Top 10 bacterial plant pathogen list. The list includes, in rank order: (1) Pseudomonas syringae pathovars; (2) Ralstonia solanacearum; (3) Agrobacterium tumefaciens; (4) Xanthomonas oryzae pv. oryzae; (5) Xanthomonas campestris pathovars; (6) Xanthomonas axonopodis pathovars; (7) Erwinia amylovora; (8) Xylella fastidiosa; (9) Dickeya (dadantii and solani); (10) Pectobacterium carotovorum (and Pectobacterium atrosepticum). Bacteria garnering honourable mentions for just missing out on the Top 10 include Clavibacter michiganensis (michiganensis and sepedonicus), Pseudomonas savastanoi and Candidatus Liberibacter asiaticus. This review article presents a short section on each bacterium in the Top 10 list and its importance, with the intention of initiating discussion and debate amongst the plant bacteriology community, as well as laying down a benchmark. It will be interesting to see, in future years, how perceptions change and which bacterial pathogens enter and leave the Top 10. © 2012 The Authors. Molecular Plant Pathology © 2012 BSPP and Blackwell Publishing Ltd.

  14. Homeostasis-altering molecular processes as mechanisms of inflammasome activation.

    Science.gov (United States)

    Liston, Adrian; Masters, Seth L

    2017-03-01

    The innate immune system uses a distinct set of germline-encoded pattern recognition receptors (PRRs) to initiate downstream inflammatory cascades. This recognition system is in stark contrast to the adaptive immune system, which relies on highly variable, randomly generated antigen receptors. A key limitation of the innate immune system's reliance on fixed PRRs is its inflexibility in responding to rapidly evolving pathogens. Recent advances in our understanding of inflammasome activation suggest that the innate immune system also has sophisticated mechanisms for responding to pathogens for which there is no fixed PRR. This includes the recognition of debris from dying cells, known as danger-associated molecular patterns (DAMPs), which can directly activate PRRs in a similar manner to pathogen-associated molecular patterns (PAMPs). Distinct from this, emerging data for the inflammasome components NLRP3 (NOD-, LRR- and pyrin domain-containing 3) and pyrin suggest that they do not directly detect molecular patterns, but instead act as signal integrators that are capable of detecting perturbations in cytoplasmic homeostasis, for example, as initiated by infection. Monitoring these perturbations, which we term 'homeostasis-altering molecular processes' (HAMPs), provides potent flexibility in the capacity of the innate immune system to detect evolutionarily novel infections; however, HAMP sensing may also underlie the sterile inflammation that drives chronic inflammatory diseases.

  15. Innate Immune Responses Activated in Arabidopsis Roots by Microbe-Associated Molecular Patterns[W][OA

    Science.gov (United States)

    Millet, Yves A.; Danna, Cristian H.; Clay, Nicole K.; Songnuan, Wisuwat; Simon, Matthew D.; Werck-Reichhart, Danièle; Ausubel, Frederick M.

    2010-01-01

    Despite the fact that roots are the organs most subject to microbial interactions, very little is known about the response of roots to microbe-associated molecular patterns (MAMPs). By monitoring transcriptional activation of β-glucuronidase reporters and MAMP-elicited callose deposition, we show that three MAMPs, the flagellar peptide Flg22, peptidoglycan, and chitin, trigger a strong tissue-specific response in Arabidopsis thaliana roots, either at the elongation zone for Flg22 and peptidoglycan or in the mature parts of the roots for chitin. Ethylene signaling, the 4-methoxy-indole-3-ylmethylglucosinolate biosynthetic pathway, and the PEN2 myrosinase, but not salicylic acid or jasmonic acid signaling, play major roles in this MAMP response. We also show that Flg22 induces the cytochrome P450 CYP71A12-dependent exudation of the phytoalexin camalexin by Arabidopsis roots. The phytotoxin coronatine, an Ile-jasmonic acid mimic produced by Pseudomonas syringae pathovars, suppresses MAMP-activated responses in the roots. This suppression requires the E3 ubiquitin ligase COI1 as well as the transcription factor JIN1/MYC2 but does not rely on salicylic acid–jasmonic acid antagonism. These experiments demonstrate the presence of highly orchestrated and tissue-specific MAMP responses in roots and potential pathogen-encoded mechanisms to block these MAMP-elicited signaling pathways. PMID:20348432

  16. Morphological, cultural, pathogenic and molecular variability ...

    African Journals Online (AJOL)

    Alternaria blight (Alternaria brassicae) causes severe foliar damage to Indian mustard in Uttarakhand. Ten (10) isolates of A. brassicae were collected from different hosts and characterized for cultural, morphological, pathogenic and molecular variations. A. brassicae colonies varied in their cultural behaviour ranging from ...

  17. Cultural, morphological, pathogenic and molecular characterization ...

    African Journals Online (AJOL)

    Alternaria blotch (Alternaria mali) causes severe foliar damage to apple trees in Kashmir. Twenty one (21) isolates of A. mali were collected from different locations and characterized for cultural, morphological, pathogenic and molecular variations. A. mali colonies varied in their cultural behaviour ranging from velvety to ...

  18. Investigating Ebola virus pathogenicity using molecular dynamics.

    Science.gov (United States)

    Pappalardo, Morena; Collu, Francesca; Macpherson, James; Michaelis, Martin; Fraternali, Franca; Wass, Mark N

    2017-08-11

    Ebolaviruses have been known to cause deadly disease in humans for 40 years and have recently been demonstrated in West Africa to be able to cause large outbreaks. Four Ebolavirus species cause severe disease associated with high mortality in humans. Reston viruses are the only Ebolaviruses that do not cause disease in humans. Conserved amino acid changes in the Reston virus protein VP24 compared to VP24 of other Ebolaviruses have been suggested to alter VP24 binding to host cell karyopherins resulting in impaired inhibition of interferon signalling, which may explain the difference in human pathogenicity. Here we used protein structural analysis and molecular dynamics to further elucidate the interaction between VP24 and KPNA5. As a control experiment, we compared the interaction of wild-type and R137A-mutant (known to affect KPNA5 binding) Ebola virus VP24 with KPNA5. Results confirmed that the R137A mutation weakens direct VP24-KPNA5 binding and enables water molecules to penetrate at the interface. Similarly, Reston virus VP24 displayed a weaker interaction with KPNA5 than Ebola virus VP24, which is likely to reduce the ability of Reston virus VP24 to prevent host cell interferon signalling. Our results provide novel molecular detail on the interaction of Reston virus VP24 and Ebola virus VP24 with human KPNA5. The results indicate a weaker interaction of Reston virus VP24 with KPNA5 than Ebola virus VP24, which is probably associated with a decreased ability to interfere with the host cell interferon response. Hence, our study provides further evidence that VP24 is a key player in determining Ebolavirus pathogenicity.

  19. Mechanisms of antimicrobial resistance among hospital-associated pathogens.

    Science.gov (United States)

    Khan, Ayesha; Miller, William R; Arias, Cesar A

    2018-04-01

    The introduction of antibiotics revolutionized medicine in the 20th-century permitting the treatment of once incurable infections. Widespread use of antibiotics, however, has led to the development of resistant organisms, particularly in the healthcare setting. Today, the clinician is often faced with pathogens carrying a cadre of resistance determinants that severely limit therapeutic options. The genetic plasticity of microbes allows them to adapt to stressors via genetic mutations, acquisition or sharing of genetic material and modulation of genetic expression leading to resistance to virtually any antimicrobial used in clinical practice. Areas covered: This is a comprehensive review that outlines major mechanisms of resistance in the most common hospital-associated pathogens including bacteria and fungi. Expert commentary: Understanding the genetic and biochemical mechanisms of such antimicrobial adaptation is crucial to tackling the rapid spread of resistance, can expose unconventional therapeutic targets to combat multidrug resistant pathogens and lead to more accurate prediction of antimicrobial susceptibility using rapid molecular diagnostics. Clinicians making treatment decisions based on the molecular basis of resistance may design therapeutic strategies that include de-escalation of broad spectrum antimicrobial usage, more focused therapies or combination therapies. These strategies are likely to improve patient outcomes and decrease the risk of resistance in hospital settings.

  20. A bacterial tyrosine phosphatase inhibits plant pattern recognition receptor activation

    Science.gov (United States)

    Perception of pathogen-associated molecular patterns (PAMPs) by surface-localised pattern-recognition receptors (PRRs) is a key component of plant innate immunity. Most known plant PRRs are receptor kinases and initiation of PAMP-triggered immunity (PTI) signalling requires phosphorylation of the PR...

  1. Molecular phylogeny, pathogenicity and toxigenicity of Fusarium oxysporum f. sp. lycopersici

    Science.gov (United States)

    Nirmaladevi, D.; Venkataramana, M.; Srivastava, Rakesh K.; Uppalapati, S. R.; Gupta, Vijai Kumar; Yli-Mattila, T.; Clement Tsui, K. M.; Srinivas, C.; Niranjana, S. R.; Chandra, Nayaka S.

    2016-01-01

    The present study aimed at the molecular characterization of pathogenic and non pathogenic F. oxysporum f. sp. lycopersici strains isolated from tomato. The causal agent isolated from symptomatic plants and soil samples was identified based on morphological and molecular analyses. Pathogenicity testing of 69 strains on five susceptible tomato varieties showed 45% of the strains were highly virulent and 30% were moderately virulent. Molecular analysis based on the fingerprints obtained through ISSR indicated the presence of wide genetic diversity among the strains. Phylogenetic analysis based on ITS sequences showed the presence of at least four evolutionary lineages of the pathogen. The clustering of F. oxysporum with non pathogenic isolates and with the members of other formae speciales indicated polyphyletic origin of F. oxysporum f. sp. lycopersici. Further analysis revealed intraspecies variability and nucleotide insertions or deletions in the ITS region among the strains in the study and the observed variations were found to be clade specific. The high genetic diversity in the pathogen population demands for development of effective resistance breeding programs in tomato. Among the pathogenic strains tested, toxigenic strains harbored the Fum1 gene clearly indicating that the strains infecting tomato crops have the potential to produce Fumonisin. PMID:26883288

  2. Molecular mechanisms underlying the emergence of bacterial pathogens: an ecological perspective.

    Science.gov (United States)

    Bartoli, Claudia; Roux, Fabrice; Lamichhane, Jay Ram

    2016-02-01

    The rapid emergence of new bacterial diseases negatively affects both human health and agricultural productivity. Although the molecular mechanisms underlying these disease emergences are shared between human- and plant-pathogenic bacteria, not much effort has been made to date to understand disease emergences caused by plant-pathogenic bacteria. In particular, there is a paucity of information in the literature on the role of environmental habitats in which plant-pathogenic bacteria evolve and on the stress factors to which these microbes are unceasingly exposed. In this microreview, we focus on three molecular mechanisms underlying pathogenicity in bacteria, namely mutations, genomic rearrangements and the acquisition of new DNA sequences through horizontal gene transfer (HGT). We briefly discuss the role of these mechanisms in bacterial disease emergence and elucidate how the environment can influence the occurrence and regulation of these molecular mechanisms by directly impacting disease emergence. The understanding of such molecular evolutionary mechanisms and their environmental drivers will represent an important step towards predicting bacterial disease emergence and developing sustainable management strategies for crops. © 2015 BSPP AND JOHN WILEY & SONS LTD.

  3. Molecular interactions between tomato and the leaf mold pathogen Cladosporium fulvum.

    Science.gov (United States)

    Rivas, Susana; Thomas, Colwyn M

    2005-01-01

    The interaction between tomato and the leaf mold pathogen Cladosporium fulvum is controlled in a gene-for-gene manner. This interaction has provided useful insights to the molecular basis of recognition specificity in plant disease resistance (R) proteins, disease resistance (R) gene evolution, R-protein mediated signaling, and cellular responses to pathogen attack. Tomato Cf genes encode type I membrane-associated receptor-like proteins (RLPs) comprised predominantly of extracellular leucine-rich repeats (eLRRs) and which are anchored in the plasma membrane. Cf proteins recognize fungal avirulence (Avr) peptides secreted into the leaf apoplast during infection. A direct interaction of Cf proteins with their cognate Avr proteins has not been demonstrated and the molecular mechanism of Avr protein perception is not known. Following ligand perception Cf proteins trigger a hypersensitive response (HR) and the arrest of pathogen development. Cf proteins lack an obvious signaling domain, suggesting that defense response activation is mediated through interactions with other partners. Avr protein perception results in the rapid accumulation of active oxygen species (AOS), changes in cellular ion fluxes, activation of protein kinase cascades, changes in gene expression and, possibly, targeted protein degradation. Here we review our current understanding of Cf-mediated responses in resistance to C. fulvum.

  4. Molecular aspects of avirulence and pathogenicity of the tomato pathogen Cladosporium fulvum

    NARCIS (Netherlands)

    Ackerveken, van den G.F.J.M.

    1993-01-01

    The molecular understanding of host-pathogen interactions and particularly of specificity forms the basis for studying plant resistance. Understanding why a certain plant species or cultivar is susceptible and why other species or cultivars are resistant is of great importance in order to

  5. In roots of Arabidopsis thaliana, the damage-associated molecular pattern AtPep1 is a stronger elicitor of immune signalling than flg22 or the chitin heptamer.

    Directory of Open Access Journals (Sweden)

    Lorenzo Poncini

    Full Text Available Plants interpret their immediate environment through perception of small molecules. Microbe-associated molecular patterns (MAMPs such as flagellin and chitin are likely to be more abundant in the rhizosphere than plant-derived damage-associated molecular patterns (DAMPs. We investigated how the Arabidopsis thaliana root interprets MAMPs and DAMPs as danger signals. We monitored root development during exposure to increasing concentrations of the MAMPs flg22 and the chitin heptamer as well as of the DAMP AtPep1. The tissue-specific expression of defence-related genes in roots was analysed using a toolkit of promoter::YFPN lines reporting jasmonic acid (JA-, salicylic acid (SA-, ethylene (ET- and reactive oxygen species (ROS- dependent signalling. Finally, marker responses were analysed during invasion by the root pathogen Fusarium oxysporum. The DAMP AtPep1 triggered a stronger activation of the defence markers compared to flg22 and the chitin heptamer. In contrast to the tested MAMPs, AtPep1 induced SA- and JA-signalling markers in the root and caused a severe inhibition of root growth. Fungal attack resulted in a strong activation of defence genes in tissues close to the invading fungal hyphae. The results collectively suggest that AtPep1 presents a stronger danger signal to the Arabidopsis root than the MAMPs flg22 and chitin heptamer.

  6. Whether the weather drives patterns of endemic amphibian chytridiomycosis: a pathogen proliferation approach.

    Directory of Open Access Journals (Sweden)

    Kris A Murray

    Full Text Available The pandemic amphibian disease chytridiomycosis often exhibits strong seasonality in both prevalence and disease-associated mortality once it becomes endemic. One hypothesis that could explain this temporal pattern is that simple weather-driven pathogen proliferation (population growth is a major driver of chytridiomycosis disease dynamics. Despite various elaborations of this hypothesis in the literature for explaining amphibian declines (e.g., the chytrid thermal-optimum hypothesis it has not been formally tested on infection patterns in the wild. In this study we developed a simple process-based model to simulate the growth of the pathogen Batrachochytrium dendrobatidis (Bd under varying weather conditions to provide an a priori test of a weather-linked pathogen proliferation hypothesis for endemic chytridiomycosis. We found strong support for several predictions of the proliferation hypothesis when applied to our model species, Litoria pearsoniana, sampled across multiple sites and years: the weather-driven simulations of pathogen growth potential (represented as a growth index in the 30 days prior to sampling; GI30 were positively related to both the prevalence and intensity of Bd infections, which were themselves strongly and positively correlated. In addition, a machine-learning classifier achieved ~72% success in classifying positive qPCR results when utilising just three informative predictors 1 GI30, 2 frog body size and 3 rain on the day of sampling. Hence, while intrinsic traits of the individuals sampled (species, size, sex and nuisance sampling variables (rainfall when sampling influenced infection patterns obtained when sampling via qPCR, our results also strongly suggest that weather-linked pathogen proliferation plays a key role in the infection dynamics of endemic chytridiomycosis in our study system. Predictive applications of the model include surveillance design, outbreak preparedness and response, climate change scenario

  7. Whether the weather drives patterns of endemic amphibian chytridiomycosis: a pathogen proliferation approach.

    Science.gov (United States)

    Murray, Kris A; Skerratt, Lee F; Garland, Stephen; Kriticos, Darren; McCallum, Hamish

    2013-01-01

    The pandemic amphibian disease chytridiomycosis often exhibits strong seasonality in both prevalence and disease-associated mortality once it becomes endemic. One hypothesis that could explain this temporal pattern is that simple weather-driven pathogen proliferation (population growth) is a major driver of chytridiomycosis disease dynamics. Despite various elaborations of this hypothesis in the literature for explaining amphibian declines (e.g., the chytrid thermal-optimum hypothesis) it has not been formally tested on infection patterns in the wild. In this study we developed a simple process-based model to simulate the growth of the pathogen Batrachochytrium dendrobatidis (Bd) under varying weather conditions to provide an a priori test of a weather-linked pathogen proliferation hypothesis for endemic chytridiomycosis. We found strong support for several predictions of the proliferation hypothesis when applied to our model species, Litoria pearsoniana, sampled across multiple sites and years: the weather-driven simulations of pathogen growth potential (represented as a growth index in the 30 days prior to sampling; GI30) were positively related to both the prevalence and intensity of Bd infections, which were themselves strongly and positively correlated. In addition, a machine-learning classifier achieved ~72% success in classifying positive qPCR results when utilising just three informative predictors 1) GI30, 2) frog body size and 3) rain on the day of sampling. Hence, while intrinsic traits of the individuals sampled (species, size, sex) and nuisance sampling variables (rainfall when sampling) influenced infection patterns obtained when sampling via qPCR, our results also strongly suggest that weather-linked pathogen proliferation plays a key role in the infection dynamics of endemic chytridiomycosis in our study system. Predictive applications of the model include surveillance design, outbreak preparedness and response, climate change scenario modelling and

  8. Molecular dynamics characterization of five pathogenic factor X mutants associated with decreased catalytic activity

    KAUST Repository

    Abdel-Azeim, Safwat; Oliva, Romina M.; Chermak, Edrisse; De Cristofaro, Raimondo; Cavallo, Luigi

    2014-01-01

    Factor X (FX) is one of the major players in the blood coagulation cascade. Upon activation to FXa, it converts prothrombin to thrombin, which in turn converts fibrinogen into fibrin (blood clots). FXa deficiency causes hemostasis defects, such as intracranial bleeding, hemathrosis, and gastrointestinal blood loss. Herein, we have analyzed a pool of pathogenic mutations, located in the FXa catalytic domain and directly associated with defects in enzyme catalytic activity. Using chymotrypsinogen numbering, they correspond to D102N, T135M, V160A, G184S, and G197D. Molecular dynamics simulations were performed for 1.68 μs on the wild-type and mutated forms of FXa. Overall, our analysis shows that four of the five mutants considered, D102N, T135M, V160A, and G184S, have rigidities higher than those of the wild type, in terms of both overall protein motion and, specifically, subpocket S4 flexibility, while S1 is rather insensitive to the mutation. This acquired rigidity can clearly impact the substrate recognition of the mutants.

  9. Molecular dynamics characterization of five pathogenic factor X mutants associated with decreased catalytic activity

    KAUST Repository

    Abdel-Azeim, Safwat

    2014-11-11

    Factor X (FX) is one of the major players in the blood coagulation cascade. Upon activation to FXa, it converts prothrombin to thrombin, which in turn converts fibrinogen into fibrin (blood clots). FXa deficiency causes hemostasis defects, such as intracranial bleeding, hemathrosis, and gastrointestinal blood loss. Herein, we have analyzed a pool of pathogenic mutations, located in the FXa catalytic domain and directly associated with defects in enzyme catalytic activity. Using chymotrypsinogen numbering, they correspond to D102N, T135M, V160A, G184S, and G197D. Molecular dynamics simulations were performed for 1.68 μs on the wild-type and mutated forms of FXa. Overall, our analysis shows that four of the five mutants considered, D102N, T135M, V160A, and G184S, have rigidities higher than those of the wild type, in terms of both overall protein motion and, specifically, subpocket S4 flexibility, while S1 is rather insensitive to the mutation. This acquired rigidity can clearly impact the substrate recognition of the mutants.

  10. Interfamily transfer of a plant pattern-recognition receptor confers broad-spectrum bacterial resistance

    NARCIS (Netherlands)

    Lacombe, S.; Rougon-Cardoso, A.; Sherwood, E.; Peeters, N.; Dahlbeck, D.; Esse, van H.P.; Smoker, M.; Rallapalli, G.; Thomma, B.P.H.J.; Staskawicz, B.; Jones, J.D.G.; Zipfel, C.

    2010-01-01

    Plant diseases cause massive losses in agriculture. Increasing the natural defenses of plants may reduce the impact of phytopathogens on agricultural productivity. Pattern-recognition receptors (PRRs) detect microbes by recognizing conserved pathogen-associated molecular patterns (PAMPs)1, 2, 3.

  11. Tick-Pathogen Ensembles: Do Molecular Interactions Lead Ecological Innovation?

    Czech Academy of Sciences Publication Activity Database

    Cabezas Cruz, Alejandro; Estrada-Peňa, A.; Rego, Ryan O. M.; de la Fuente, J.

    2017-01-01

    Roč. 7, 13 March (2017), č. článku 74. ISSN 2235-2988 Institutional support: RVO:60077344 Keywords : tick-pathogen interactions * transcriptional reprogramming * epigenetics * ecological adaptation * Anaplasma phagocytophilum Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 4.300, year: 2016

  12. Early immune response patterns to pathogenic bacteria are associated to increased risk of lower respiratory infections in children

    DEFF Research Database (Denmark)

    Vissing, N. H.; Larsen, Jeppe Madura; Rasmussen, Mette Annelie

    2014-01-01

    Neonatal colonisation of the airways with respiratory pathogens is associated with increased risk of lower respiratory infections (LRI) in early childhood (1). Therefore, we hypothesized that children developing LRI have an abnormal immune response to pathogenic bacteria in infancy. We aimed...... to characterise the systemic immune response to pathogenic bacteria at the age of 6 months and study the association with incidence of LRI during the first 3 years of life....

  13. Molecular assessment of bacterial pathogens - a contribution to drinking water safety.

    Science.gov (United States)

    Brettar, Ingrid; Höfle, Manfred G

    2008-06-01

    Human bacterial pathogens are considered as an increasing threat to drinking water supplies worldwide because of the growing demand of high-quality drinking water and the decreasing quality and quantity of available raw water. Moreover, a negative impact of climate change on freshwater resources is expected. Recent advances in molecular detection technologies for bacterial pathogens in drinking water bear the promise in improving the safety of drinking water supplies by precise detection and identification of the pathogens. More importantly, the array of molecular approaches allows understanding details of infection routes of waterborne diseases, the effects of changes in drinking water treatment, and management of freshwater resources.

  14. Molecular Mechanisms of Bacterial Pathogenicity

    Science.gov (United States)

    Fuchs, Thilo Martin

    Cautious optimism has arisen over recent decades with respect to the long struggle against bacteria, viruses, and parasites. This has been offset, however, by a fatal complacency stemming from previous successes such as the development of antimicrobial drugs, the eradication of smallpox, and global immunization programs. Infectious diseases nevertheless remain the world's leading cause of death, killing at least 17 million persons annually [61]. Diarrheal diseases caused by Vibrio cholerae or Shigella dysenteriae kill about 3 million persons every year, most of them young children: Another 4 million die of tuberculosis or tetanus. Outbreaks of diphtheria in Eastern Europe threatens the population with a disease that had previously seemed to be overcome. Efforts to control infectious diseases more comprehensively are undermined not only by socioeconomic conditions but also by the nature of the pathogenic organisms itself; some isolates of Staphylococcus aureus and Enterobacter have become so resistant to drugs by horizontal gene transfer that they are almost untreatable. In addition, the mechanism of genetic variability helps pathogens to evade the human immune system, thus compromising the development of powerful vaccines. Therefore detailed knowledge of the molecular mechanisms of microbial pathogenicity is absolutely necessary to develop new strategies against infectious diseases and thus to lower their impact on human health and social development.

  15. The Human Pathogen Streptococcus pyogenes Releases Lipoproteins as Lipoprotein-rich Membrane Vesicles.

    Science.gov (United States)

    Biagini, Massimiliano; Garibaldi, Manuela; Aprea, Susanna; Pezzicoli, Alfredo; Doro, Francesco; Becherelli, Marco; Taddei, Anna Rita; Tani, Chiara; Tavarini, Simona; Mora, Marirosa; Teti, Giuseppe; D'Oro, Ugo; Nuti, Sandra; Soriani, Marco; Margarit, Immaculada; Rappuoli, Rino; Grandi, Guido; Norais, Nathalie

    2015-08-01

    Bacterial lipoproteins are attractive vaccine candidates because they represent a major class of cell surface-exposed proteins in many bacteria and are considered as potential pathogen-associated molecular patterns sensed by Toll-like receptors with built-in adjuvanticity. Although Gram-negative lipoproteins have been extensively characterized, little is known about Gram-positive lipoproteins. We isolated from Streptococcus pyogenes a large amount of lipoproteins organized in vesicles. These vesicles were obtained by weakening the bacterial cell wall with a sublethal concentration of penicillin. Lipid and proteomic analysis of the vesicles revealed that they were enriched in phosphatidylglycerol and almost exclusively composed of lipoproteins. In association with lipoproteins, a few hypothetical proteins, penicillin-binding proteins, and several members of the ExPortal, a membrane microdomain responsible for the maturation of secreted proteins, were identified. The typical lipidic moiety was apparently not necessary for lipoprotein insertion in the vesicle bilayer because they were also recovered from the isogenic diacylglyceryl transferase deletion mutant. The vesicles were not able to activate specific Toll-like receptor 2, indicating that lipoproteins organized in these vesicular structures do not act as pathogen-associated molecular patterns. In light of these findings, we propose to name these new structures Lipoprotein-rich Membrane Vesicles. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Uncovering plant-pathogen crosstalk through apoplastic proteomic studies.

    Science.gov (United States)

    Delaunois, Bertrand; Jeandet, Philippe; Clément, Christophe; Baillieul, Fabienne; Dorey, Stéphan; Cordelier, Sylvain

    2014-01-01

    Plant pathogens have evolved by developing different strategies to infect their host, which in turn have elaborated immune responses to counter the pathogen invasion. The apoplast, including the cell wall and extracellular space outside the plasma membrane, is one of the first compartments where pathogen-host interaction occurs. The plant cell wall is composed of a complex network of polysaccharides polymers and glycoproteins and serves as a natural physical barrier against pathogen invasion. The apoplastic fluid, circulating through the cell wall and intercellular spaces, provides a means for delivering molecules and facilitating intercellular communications. Some plant-pathogen interactions lead to plant cell wall degradation allowing pathogens to penetrate into the cells. In turn, the plant immune system recognizes microbial- or damage-associated molecular patterns (MAMPs or DAMPs) and initiates a set of basal immune responses, including the strengthening of the plant cell wall. The establishment of defense requires the regulation of a wide variety of proteins that are involved at different levels, from receptor perception of the pathogen via signaling mechanisms to the strengthening of the cell wall or degradation of the pathogen itself. A fine regulation of apoplastic proteins is therefore essential for rapid and effective pathogen perception and for maintaining cell wall integrity. This review aims to provide insight into analyses using proteomic approaches of the apoplast to highlight the modulation of the apoplastic protein patterns during pathogen infection and to unravel the key players involved in plant-pathogen interaction.

  17. Molecular and Genomic Characterization of Enteric Pathogens Circulating during Hajj

    KAUST Repository

    Alsomali, Mona

    2016-05-01

    Hajj, the annual Muslim pilgrimage to Mecca, Saudi Arabia is a unique mass gathering event that attracts approximately 3 million pilgrims from around the globe. This diverse pilgrim population coupled with the nature of the performed activities raise major public health concerns in the host country with potential global implications. Although gastroenteritis and diarrhea are common among the pilgrims performing Hajj, the microbial etiologies of these infections are still unknown. We used molecular and antigenic approaches to identify the main pathogens associated with Hajj diarrhea. 544 fecal samples from pilgrims suffering from diarrhea whilst performing Hajj during three consecutive seasons (2011-2013) and 99 control samples from 2011 were screened for 16 pathogens that include bacterial, parasitic and viral etiologies that are commonly associated with diarrheal infections. At least one of the screened pathogens could be detected in 42% (n=228) of the samples from the diarrheal cases. Bacteria were the main agents detected in 83% (n=189) of the positive samples, followed by viral and parasitic agents detected in 6% (n=14) and 5% (n=12) respectively. We have also standardized a 16S-based metagenomic approach to identify the gut microbiome in diarrheal cases and non-diarrheal controls in 76 samples. Also, we have standardized a shotgun metagenomics protocol for the direct characterization (diagnosis) of enteric pathogens without cultivation. This approach was used successfully to identify viral (adenovirus) and bacterial causes of Enterotoxigenic E. coli diarrhea from Hajj samples. The findings in this study fill in clear gaps in our knowledge of the etiologies associated with diarrheal infections during Hajj. Foodborne bacteria were the major contributors to Hajj-diarrheal infections. This was coupled with the increased incidences of antimicrobial resistance loci associated with the identified bacteria. These findings would help the public health policy makers to

  18. Ecosystem screening approach for pathogen-associated microorganisms affecting host disease.

    Science.gov (United States)

    Galiana, Eric; Marais, Antoine; Mura, Catherine; Industri, Benoît; Arbiol, Gilles; Ponchet, Michel

    2011-09-01

    The microbial community in which a pathogen evolves is fundamental to disease outcome. Species interacting with a pathogen on the host surface shape the distribution, density, and genetic diversity of the inoculum, but the role of these species is rarely determined. The screening method developed here can be used to characterize pathogen-associated species affecting disease. This strategy involves three steps: (i) constitution of the microbial community, using the pathogen as a trap; (ii) community selection, using extracts from the pathogen as the sole nutrient source; and (iii) molecular identification and the screening of isolates focusing on their effects on the growth of the pathogen in vitro and host disease. This approach was applied to a soilborne plant pathogen, Phytophthora parasitica, structured in a biofilm, for screening the microbial community from the rhizosphere of Nicotiana tabacum (the host). Two of the characterized eukaryotes interfered with the oomycete cycle and may affect the host disease. A Vorticella species acted through a mutualistic interaction with P. parasitica, disseminating pathogenic material by leaving the biofilm. A Phoma species established an amensal interaction with P. parasitica, strongly suppressing disease by inhibiting P. parasitica germination. This screening method is appropriate for all nonobligate pathogens. It allows the definition of microbial species as promoters or suppressors of a disease for a given biotope. It should also help to identify important microbial relationships for ecology and evolution of pathogens.

  19. Convergent Evolution of Pathogen Effectors toward Reactive Oxygen Species Signaling Networks in Plants.

    Science.gov (United States)

    Jwa, Nam-Soo; Hwang, Byung Kook

    2017-01-01

    Microbial pathogens have evolved protein effectors to promote virulence and cause disease in host plants. Pathogen effectors delivered into plant cells suppress plant immune responses and modulate host metabolism to support the infection processes of pathogens. Reactive oxygen species (ROS) act as cellular signaling molecules to trigger plant immune responses, such as pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity. In this review, we discuss recent insights into the molecular functions of pathogen effectors that target multiple steps in the ROS signaling pathway in plants. The perception of PAMPs by pattern recognition receptors leads to the rapid and strong production of ROS through activation of NADPH oxidase Respiratory Burst Oxidase Homologs (RBOHs) as well as peroxidases. Specific pathogen effectors directly or indirectly interact with plant nucleotide-binding leucine-rich repeat receptors to induce ROS production and the hypersensitive response in plant cells. By contrast, virulent pathogens possess effectors capable of suppressing plant ROS bursts in different ways during infection. PAMP-triggered ROS bursts are suppressed by pathogen effectors that target mitogen-activated protein kinase cascades. Moreover, pathogen effectors target vesicle trafficking or metabolic priming, leading to the suppression of ROS production. Secreted pathogen effectors block the metabolic coenzyme NADP-malic enzyme, inhibiting the transfer of electrons to the NADPH oxidases (RBOHs) responsible for ROS generation. Collectively, pathogen effectors may have evolved to converge on a common host protein network to suppress the common plant immune system, including the ROS burst and cell death response in plants.

  20. Convergent Evolution of Pathogen Effectors toward Reactive Oxygen Species Signaling Networks in Plants

    Directory of Open Access Journals (Sweden)

    Nam-Soo Jwa

    2017-09-01

    Full Text Available Microbial pathogens have evolved protein effectors to promote virulence and cause disease in host plants. Pathogen effectors delivered into plant cells suppress plant immune responses and modulate host metabolism to support the infection processes of pathogens. Reactive oxygen species (ROS act as cellular signaling molecules to trigger plant immune responses, such as pathogen-associated molecular pattern (PAMP-triggered immunity (PTI and effector-triggered immunity. In this review, we discuss recent insights into the molecular functions of pathogen effectors that target multiple steps in the ROS signaling pathway in plants. The perception of PAMPs by pattern recognition receptors leads to the rapid and strong production of ROS through activation of NADPH oxidase Respiratory Burst Oxidase Homologs (RBOHs as well as peroxidases. Specific pathogen effectors directly or indirectly interact with plant nucleotide-binding leucine-rich repeat receptors to induce ROS production and the hypersensitive response in plant cells. By contrast, virulent pathogens possess effectors capable of suppressing plant ROS bursts in different ways during infection. PAMP-triggered ROS bursts are suppressed by pathogen effectors that target mitogen-activated protein kinase cascades. Moreover, pathogen effectors target vesicle trafficking or metabolic priming, leading to the suppression of ROS production. Secreted pathogen effectors block the metabolic coenzyme NADP-malic enzyme, inhibiting the transfer of electrons to the NADPH oxidases (RBOHs responsible for ROS generation. Collectively, pathogen effectors may have evolved to converge on a common host protein network to suppress the common plant immune system, including the ROS burst and cell death response in plants.

  1. Phenotypic and molecular typing of Vibrio harveyi isolates and their pathogenicity to tiger shrimp larvae.

    Science.gov (United States)

    Alavandi, S V; Manoranjita, V; Vijayan, K K; Kalaimani, N; Santiago, T C

    2006-11-01

    The objective of the present study was to identify the biotype(s) and molecular type(s) of Vibrio harveyi associated with pathogenicity in tiger shrimp (Penaeus monodon) larvae. Five luminescent and four nonluminescent V. harveyi isolates were subjected to phenotyping and random amplified polymorphic DNA (RAPD) fingerprinting, and pathogenicity testing to P. monodon mysis. Four isolates induced 34-41% mortality of P. monodon mysis when challenged at the rate of 10(6) CFU ml(-1) within 60 h. Sucrose-fermenting biotypes of V. harveyi appeared to be associated with pathogenicity to larval shrimp. Higher temperature and salinity appeared to play a role on the onset of vibriosis and mortality in the challenged larval shrimp. Pathogenic isolates of V. harveyi could be demarcated as revealed by their clustering in the dendrogram constructed based on the RAPD fingerprints. Nonluminescent V. harveyi also appear to be important aetiological agents of vibriosis of shrimp larvae. Sucrose-fermenting biotypes are likely to be pathogenic. High temperature may trigger onset of vibriosis. Biotyping of V. harveyi isolates and looking for traits, such as ability to ferment sucrose may be helpful in identifying the pathogenic forms, and such approach requires to be investigated further with larger number of isolates.

  2. Blood transfusion products contain mitochondrial DNA damage-associated molecular patterns: a potential effector of transfusion-related acute lung injury.

    Science.gov (United States)

    Lee, Yann-Leei; King, Madelyn B; Gonzalez, Richard P; Brevard, Sidney B; Frotan, M Amin; Gillespie, Mark N; Simmons, Jon D

    2014-10-01

    Transfusion-related acute lung injury (TRALI) is the most frequent and severe complication in patients receiving multiple blood transfusions. Current pathogenic concepts hold that proinflammatory mediators present in transfused blood products are responsible for the initiation of TRALI, but the identity of the critical effector molecules is yet to be determined. We hypothesize that mtDNA damage-associated molecular patterns (DAMPs) are present in blood transfusion products, which may be important in the initiation of TRALI. DNA was extracted from consecutive samples of packed red blood cells, fresh frozen plasma (FFP), and platelets procured from the local blood bank. Quantitative real-time polymerase chain reaction was used to quantify ≈200 bp sequences from the COX1, ND1, ND6, and D-loop regions of the mitochondrial genome. A range of mtDNA DAMPs were detected in all blood components measured, with FFP displaying the largest variation. We conclude that mtDNA DAMPs are present in packed red blood cells, FFP, and platelets. These observations provide proof of the concept that mtDNA DAMPs may be mediators of TRALI. Further studies are needed to test this hypothesis and to determine the origin of mtDNA DAMPs in transfused blood. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Dietary Patterns and Risk of Colorectal Cancer: Analysis by Tumor Location and Molecular Subtypes.

    Science.gov (United States)

    Mehta, Raaj S; Song, Mingyang; Nishihara, Reiko; Drew, David A; Wu, Kana; Qian, Zhi Rong; Fung, Teresa T; Hamada, Tsuyoshi; Masugi, Yohei; da Silva, Annacarolina; Shi, Yan; Li, Wanwan; Gu, Mancang; Willett, Walter C; Fuchs, Charles S; Giovannucci, Edward L; Ogino, Shuji; Chan, Andrew T

    2017-06-01

    Western and prudent dietary patterns have been associated with higher and lower risks of colorectal cancer (CRC), respectively. However, little is known about the associations between dietary patterns and specific anatomic subsites or molecular subtypes of CRC. We used multivariable Cox proportional hazards models to examine the associations between Western and prudent dietary patterns and CRC risk in the Health Professionals Follow-up Study and Nurses' Health Study. After up to 32 years of follow-up of 137,217 men and women, we documented 3260 cases of CRC. Among individuals from whom subsite data were available, we observed 1264 proximal colon, 866 distal colon, and 670 rectal tumors. Western diet was associated with an increased incidence of CRC (P trend pattern, we observed a RR of 0.86 for overall CRC (95% CI, 0.77-0.95; P trend  = .01), with similar trends at anatomic subsites. However, the trend appeared stronger among men than women. Among 1285 cases (39%) with tissue available for molecular profiling, Western diet appeared to be more strongly associated with some CRC molecular subtypes (no mutations in KRAS [KRAS wildtype] or BRAF [BRAF wildtype], no or a low CpG island methylator phenotype, and microsatellite stability), although formal tests for heterogeneity did not produce statistically significant results. Western dietary patterns are associated with an increased risk of CRC, particularly distal colon and rectal tumors. Western dietary patterns also appear more strongly associated with tumors that are KRAS wildtype, BRAF wildtype, have no or a low CpG island methylator phenotype, and microsatellite stability. In contrast, prudent dietary patterns are associated with a lower risk of CRC that does not vary according to anatomic subsite or molecular subtype. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

  4. Widespread molecular patterns associated with drug sensitivity in breast cancer cell lines, with implications for human tumors.

    Directory of Open Access Journals (Sweden)

    Chad J Creighton

    Full Text Available BACKGROUND: Recent landmark studies have profiled cancer cell lines for molecular features, along with measuring the corresponding growth inhibitory effects for specific drug compounds. These data present a tool for determining which subsets of human cancer might be more responsive to particular drugs. To this end, the NCI-DREAM-sponsored DREAM7: Drug Sensitivity Prediction Challenge (sub-challenge 1 set out to predict the sensitivities of 18 breast cancer cell lines to 31 previously untested compounds, on the basis of molecular profiling data and a training subset of cell lines. METHODS AND RESULTS: With 47 teams submitting blinded predictions, team Creighton scored third in terms of overall accuracy. Team Creighton's method was simple and straightforward, incorporated multiple expression data types (RNA-seq, gene array, RPPA, and incorporated all profiled features (not only the "best" predictive ones. As an extension of the approach, cell line data, from public datasets of expression profiling coupled with drug sensitivities (Barretina, Garnett, Heiser were used to "predict" the drug sensitivities in human breast tumors (using data from The Cancer Genome Atlas. Drug sensitivity correlations within human breast tumors showed differences by expression-based subtype, with many associations in line with the expected (e.g. Lapatinib sensitivity in HER2-enriched cancers and others inviting further study (e.g. relative resistance to PI3K inhibitors in basal-like cancers. CONCLUSIONS: Molecular patterns associated with drug sensitivity are widespread, with potentially hundreds of genes that could be incorporated into making predictions, as well as offering biological clues as to the mechanisms involved. Applying the cell line patterns to human tumor data may help generate hypotheses on what tumor subsets might be more responsive to therapies, where multiple cell line datasets representing various drugs may be used, in order to assess consistency of

  5. Automated Processing of 2-D Gel Electrophoretograms of Genomic DNA for Hunting Pathogenic DNA Molecular Changes.

    Science.gov (United States)

    Takahashi; Nakazawa; Watanabe; Konagaya

    1999-01-01

    We have developed the automated processing algorithms for 2-dimensional (2-D) electrophoretograms of genomic DNA based on RLGS (Restriction Landmark Genomic Scanning) method, which scans the restriction enzyme recognition sites as the landmark and maps them onto a 2-D electrophoresis gel. Our powerful processing algorithms realize the automated spot recognition from RLGS electrophoretograms and the automated comparison of a huge number of such images. In the final stage of the automated processing, a master spot pattern, on which all the spots in the RLGS images are mapped at once, can be obtained. The spot pattern variations which seemed to be specific to the pathogenic DNA molecular changes can be easily detected by simply looking over the master spot pattern. When we applied our algorithms to the analysis of 33 RLGS images derived from human colon tissues, we successfully detected several colon tumor specific spot pattern changes.

  6. Molecular diagnostics for the detection and characterization of microbial pathogens.

    Science.gov (United States)

    Procop, Gary W

    2007-09-01

    New and advanced methods of molecular diagnostics are changing the way we practice clinical microbiology, which affects the practice of medicine. Signal amplification and real-time nucleic acid amplification technologies offer a sensitive and specific result with a more rapid turnaround time than has ever before been possible. Numerous methods of postamplification analysis afford the simultaneous detection and differentiation of numerous microbial pathogens, their mechanisms of resistance, and the construction of disease-specific assays. The technical feasibility of these assays has already been demonstrated. How these new, often more expensive tests will be incorporated into routine practice and the impact they will have on patient care remain to be determined. One of the most attractive uses for such techniques is to achieve a more rapid characterization of the infectious agent so that a narrower-spectrum antimicrobial agent may be used, which should have an impact on resistance patterns.

  7. Spectrum of pathogenic mutations and associated polymorphisms in a cohort of 44 unrelated patients with long QT syndrome.

    Science.gov (United States)

    Millat, G; Chevalier, P; Restier-Miron, L; Da Costa, A; Bouvagnet, P; Kugener, B; Fayol, L; Gonzàlez Armengod, C; Oddou, B; Chanavat, V; Froidefond, E; Perraudin, R; Rousson, R; Rodriguez-Lafrasse, C

    2006-09-01

    Long QT syndrome (LQTS) is a rare and clinically heterogeneous inherited disorder characterized by a long QT interval on the electrocardiogram, increased risk of syncope and sudden death caused by arrhythmias. This syndrome is mostly caused by mutations in genes encoding various cardiac ion channels. The clinical heterogeneity is usually attributed to variable penetrance. One of the reasons for this variability in expression could be the coexistence of common single nucleotide polymorphisms (SNPs) on LQTS-causing genes and/or unknown genes. Some synonymous and nonsynonymous exonic SNPs identified in LQTS-causing genes may have an effect on the cardiac repolarization process and modulate the clinical expression of a latent LQTS pathogenic mutation. We report the molecular pattern of 44 unrelated patients with LQTS using denaturing high-performance liquid chromatography analysis of the KCNQ1, KCNH2, SCN5A, KCNE1 and KCNE2 genes. Forty-five disease-causing mutations (including 24 novel ones) were identified in this cohort. Most of our patients (84%) showed complex molecular pattern with one mutation (and even two for four patients) associated with several SNPs located in several LQTS genes.

  8. Morphological and molecular characterization of Fusarium spp pathogenic to pecan tree in Brazil.

    Science.gov (United States)

    Lazarotto, M; Milanesi, P M; Muniz, M F B; Reiniger, L R S; Beltrame, R; Harakava, R; Blume, E

    2014-11-11

    The occurrence of Fusarium spp associated with pecan tree (Carya illinoinensis) diseases in Brazil has been observed in recent laboratory analyses in Rio Grande do Sul State. Thus, in this study, we i) obtained Fusarium isolates from plants with disease symptoms; ii) tested the pathogenicity of these Fusarium isolates to pecan; iii) characterized and grouped Fusarium isolates that were pathogenic to the pecan tree based on morphological characteristics; iv) identified Fusarium spp to the species complex level through TEF-1α sequencing; and v) compared the identification methods used in the study. Fifteen isolates collected from the inflorescences, roots, and seeds of symptomatic plants (leaf necrosis or root rot) were used for pathogenicity tests. Morphological characterization was conducted using only pathogenic isolates, for a total of 11 isolates, based on the mycelial growth rate, sporulation, colony pigmentation, and conidial length and width variables. Pathogenic isolates were grouped based on morphological characteristics, and molecular characterization was performed by sequencing TEF-1α genes. Pathogenic isolates belonging to the Fusarium chlamydosporum species complex, Fusarium graminearum species complex, Fusarium proliferatum, and Fusarium oxysporum were identified based on the TEF-1α region. Morphological characteristics were used to effectively differentiate isolates and group the isolates according to genetic similarity, particularly conidial width, which emerged as a key morphological descriptor in this study.

  9. Immunity to plant pathogens and iron homeostasis.

    Science.gov (United States)

    Aznar, Aude; Chen, Nicolas W G; Thomine, Sebastien; Dellagi, Alia

    2015-11-01

    Iron is essential for metabolic processes in most living organisms. Pathogens and their hosts often compete for the acquisition of this nutrient. However, iron can catalyze the formation of deleterious reactive oxygen species. Hosts may use iron to increase local oxidative stress in defense responses against pathogens. Due to this duality, iron plays a complex role in plant-pathogen interactions. Plant defenses against pathogens and plant response to iron deficiency share several features, such as secretion of phenolic compounds, and use common hormone signaling pathways. Moreover, fine tuning of iron localization during infection involves genes coding iron transport and iron storage proteins, which have been shown to contribute to immunity. The influence of the plant iron status on the outcome of a given pathogen attack is strongly dependent on the nature of the pathogen infection strategy and on the host species. Microbial siderophores emerged as important factors as they have the ability to trigger plant defense responses. Depending on the plant species, siderophore perception can be mediated by their strong iron scavenging capacity or possibly via specific recognition as pathogen associated molecular patterns. This review highlights that iron has a key role in several plant-pathogen interactions by modulating immunity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Molecular mechanism of extreme mechanostability in a pathogen adhesin.

    Science.gov (United States)

    Milles, Lukas F; Schulten, Klaus; Gaub, Hermann E; Bernardi, Rafael C

    2018-03-30

    High resilience to mechanical stress is key when pathogens adhere to their target and initiate infection. Using atomic force microscopy-based single-molecule force spectroscopy, we explored the mechanical stability of the prototypical staphylococcal adhesin SdrG, which targets a short peptide from human fibrinogen β. Steered molecular dynamics simulations revealed, and single-molecule force spectroscopy experiments confirmed, the mechanism by which this complex withstands forces of over 2 nanonewtons, a regime previously associated with the strength of a covalent bond. The target peptide, confined in a screwlike manner in the binding pocket of SdrG, distributes forces mainly toward the peptide backbone through an intricate hydrogen bond network. Thus, these adhesins can attach to their target with exceptionally resilient mechanostability, virtually independent of peptide side chains. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  11. COXIELLA BURNETII PATHOGENICITY MOLECULAR BASIS

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    Yu. A. Panferova

    2016-01-01

    Full Text Available Coxiella burnetii is an obligate intracellular gram-negative bacterial pathogen, an ethiological agent of Q-fever, a zoonotic disease, elapsing as an acute (mostly atypical pneumonia or a chronic (mostly endocarditis form. The host range is represented by wide range of mammal, avian and arthropod species, but the main source of human infection are farm animals. The main route of infection is aerosolic. In case of contact with organism pathogen binds with phagocytal monocytic-macrophagal cell line. C. burnetii promotes maturation of specific phagolysosome-like compartment in host cell, called coxiella-containing vacuole, within this vacuole pathogen becames metabolically activated and actively replicates. Coxiella persists as metabolically inactive spore-like form in environment. Internalisation of C. burnetii occurs using actin-mediated phagocytosis and zipper mechanism. After internalization of bacteria maturation of phagolysosome-like compartment and large coxiella-containing vacuole formation occure, and vacuole can occupy nearly the whole cytoplasm of the host cell. Survivance of infected cells is important for chronic infection with C. burnetii. C. burnetii elongate the viability of host cell by two ways: it actively inhibits apoptotic signal cascades and induce pro-survival factors. Exceptthat C. burnetii involves autophagic pathway during coxiella-containing vacuole formation, and induction of autophagy promotes pathogen replication. During infection C. burnetii translocates effector substrates from bacterial cytosole to euca ryotic host cell cytosole using type IV secretion system, where effectors modulate host cell proteins. Overall approximately 130 secreted effectors of type IV transport system, but function of most of them remains unknown to date. Specific sec reted proteins for variety of strains and isolates were identified, confirmed that certain pathotypes of C. burnetii can exist. Identification and

  12. MORPHOLOGICAL AND MOLECULAR IDENTIFICATION OF Fusarium SPECIES AND THEIR PATHOGENICITY FOR WHEAT

    Directory of Open Access Journals (Sweden)

    Jelena Poštić

    2012-12-01

    Full Text Available From the root and lower stem parts of weeds and plant debris of maize, wheat, oat and sunflower we isolated 300 isolates of Fusarium spp. and performed morphological and molecular identification. With molecular identification using AFLP method we determined 14 Fusarium species: F. acuminatum, F. avenaceum, F. concolor, F. crookwellense, F. equiseti, F. graminearum, F. oxysporum, F. proliferatum, F. semitectum, F. solani, F. sporotrichioides, F. subglutinans, F. venenatum and F. verticillioides.By comparing results of morphological and molecular identification we found out that determination of 16,7% isolates was incorrect. Out of 300 isolates identified with molecular methods, 50 did not belong to the species determined with morphological determination.With pathogenicity tests of 30 chosen Fusarium isolates we determined that many of them were pathogenic to wheat and maize seedlings and to wheat heads. The most pathogenic were isolates of F. graminearum from A. retroflexus, A. theophrasti and C. album, F. venenatum from maize debris and and A. theophrasti, F. crookwellense from A. lappa. Antifungal influence of 11 essential oils on mycelia growth and sporulation of chosen Fusarium isolates determined that essential oils of T. vulgaris, P. anisum and E. caryophyllus had the strongest effect on mycelial growth. Influence of essential oils on sporulation was not statistically significant.

  13. Overlapping Patterns of Rapid Evolution in the Nucleic Acid Sensors cGAS and OAS1 Suggest a Common Mechanism of Pathogen Antagonism and Escape.

    Science.gov (United States)

    Hancks, Dustin C; Hartley, Melissa K; Hagan, Celia; Clark, Nathan L; Elde, Nels C

    2015-05-01

    A diverse subset of pattern recognition receptors (PRRs) detects pathogen-associated nucleic acids to initiate crucial innate immune responses in host organisms. Reflecting their importance for host defense, pathogens encode various countermeasures to evade or inhibit these immune effectors. PRRs directly engaged by pathogen inhibitors often evolve under recurrent bouts of positive selection that have been described as molecular 'arms races.' Cyclic GMP-AMP synthase (cGAS) was recently identified as a key PRR. Upon binding cytoplasmic double-stranded DNA (dsDNA) from various viruses, cGAS generates the small nucleotide secondary messenger cGAMP to signal activation of innate defenses. Here we report an evolutionary history of cGAS with recurrent positive selection in the primate lineage. Recent studies indicate a high degree of structural similarity between cGAS and 2'-5'-oligoadenylate synthase 1 (OAS1), a PRR that detects double-stranded RNA (dsRNA), despite low sequence identity between the respective genes. We present comprehensive comparative evolutionary analysis of cGAS and OAS1 primate sequences and observe positive selection at nucleic acid binding interfaces and distributed throughout both genes. Our data revealed homologous regions with strong signatures of positive selection, suggesting common mechanisms employed by unknown pathogen encoded inhibitors and similar modes of evasion from antagonism. Our analysis of cGAS diversification also identified alternately spliced forms missing multiple sites under positive selection. Further analysis of selection on the OAS family in primates, which comprises OAS1, OAS2, OAS3 and OASL, suggests a hypothesis where gene duplications and domain fusion events result in paralogs that provide another means of escaping pathogen inhibitors. Together our comparative evolutionary analysis of cGAS and OAS provides new insights into distinct mechanisms by which key molecular sentinels of the innate immune system have adapted

  14. Overlapping Patterns of Rapid Evolution in the Nucleic Acid Sensors cGAS and OAS1 Suggest a Common Mechanism of Pathogen Antagonism and Escape.

    Directory of Open Access Journals (Sweden)

    Dustin C Hancks

    2015-05-01

    Full Text Available A diverse subset of pattern recognition receptors (PRRs detects pathogen-associated nucleic acids to initiate crucial innate immune responses in host organisms. Reflecting their importance for host defense, pathogens encode various countermeasures to evade or inhibit these immune effectors. PRRs directly engaged by pathogen inhibitors often evolve under recurrent bouts of positive selection that have been described as molecular 'arms races.' Cyclic GMP-AMP synthase (cGAS was recently identified as a key PRR. Upon binding cytoplasmic double-stranded DNA (dsDNA from various viruses, cGAS generates the small nucleotide secondary messenger cGAMP to signal activation of innate defenses. Here we report an evolutionary history of cGAS with recurrent positive selection in the primate lineage. Recent studies indicate a high degree of structural similarity between cGAS and 2'-5'-oligoadenylate synthase 1 (OAS1, a PRR that detects double-stranded RNA (dsRNA, despite low sequence identity between the respective genes. We present comprehensive comparative evolutionary analysis of cGAS and OAS1 primate sequences and observe positive selection at nucleic acid binding interfaces and distributed throughout both genes. Our data revealed homologous regions with strong signatures of positive selection, suggesting common mechanisms employed by unknown pathogen encoded inhibitors and similar modes of evasion from antagonism. Our analysis of cGAS diversification also identified alternately spliced forms missing multiple sites under positive selection. Further analysis of selection on the OAS family in primates, which comprises OAS1, OAS2, OAS3 and OASL, suggests a hypothesis where gene duplications and domain fusion events result in paralogs that provide another means of escaping pathogen inhibitors. Together our comparative evolutionary analysis of cGAS and OAS provides new insights into distinct mechanisms by which key molecular sentinels of the innate immune system

  15. Molecular biology of Ganoderma pathogenicity and diagnosis in coconut seedlings.

    Science.gov (United States)

    Kandan, A; Radjacommare, R; Ramanathan, A; Raguchander, T; Balasubramanian, P; Samiyappan, R

    2009-01-01

    The pathogenicity of Ganoderma boninense was tested on coconut seedlings under greenhouse conditions and infection confirmed by using immunological and molecular diagnostic tools. Desiccation of older leaves and the emergence of sporophores were observed from pathogen-inoculated seedlings, whereas a control seedling does not show any pathogenic symptoms. Mature sporophores were formed within 10-13 weeks after inoculation. Polyclonal antibodies raised against mycelial proteins of Ganoderma were used for detection of Ganoderma in infected field palm and seedlings through indirect enzyme-linked immunosorbent assay technique. We adopted dot-immunobinding assay for the detection of Ganoderma from greenhouse and field samples. Under nucleic-acid-based diagnosis, G. boninense (167 bp) was detected from artificially inoculated seedlings and infected field palms by polymerase chain reaction. Apart from these, histopathological studies also support the Ganoderma pathogenicity in coconut seedlings. The pathogenicity test and combination of all the three diagnostic methods for Ganoderma could be highly reliable, rapid, sensitive and effective screening of resistance in planting material in the future.

  16. Inventory and update on argasid ticks and associated pathogens in Algeria.

    Science.gov (United States)

    Lafri, I; Benredjem, W; Neffah-Baaziz, F; Lalout, R; Abdelouahed, K; Gassen, B; Bakhouch, S; Chergui, M; Karakellah, M; Adjmi-Hamoudi, H; Bitam, I

    2018-05-01

    Argasid ticks include vectors of relapsing fevers caused by Borrelia spp. in humans, and they can transmit arboviruses and other bacterial pathogens. Knowledge about soft ticks ( Ixodida: Argasidae ) in Algeria is incomplete, and distribution data need to be updated. Here we report a series of entomologic investigations that we conducted in five different areas in Algeria between 2012 and 2015. Ticks were identified by entomologic keys and molecular tools (16S rRNA gene). Six distinct species belonging to two genera were identified, including Ornithodoros capensis s.s., Ornithodoros rupestris, Ornithodoros occidentalis, Ornithodoros erraticus, Ornithodoros sonrai and Argas persicus. The present study highlights the distribution of soft ticks, the establishment of an update inventory with nine species and associated pathogens detected in argasid ticks in Algeria.

  17. Short communication: Molecular characteristics, antimicrobial susceptibility, and pathogenicity of clinical Nocardia cyriacigeorgica isolates from an outbreak of bovine mastitis.

    Science.gov (United States)

    Chen, Wei; Liu, Yongxia; Barkema, Herman W; Gao, Jian; De Buck, Jeroen; Kastelic, John P; Liu, Gang; Ali, Tariq; Shahid, Muhammad; Han, Bo

    2017-10-01

    The occurrence of nocardial mastitis, mostly in the context of outbreaks, has been reported in many countries. However, there is a paucity of reports regarding detailed characterization of Nocardia cyriacigeorgica from bovine mastitis. Thus, herein we report characteristics, antimicrobial susceptibility patterns, molecular identification, and pathogenicity of N. cyriacigeorgica isolated from an outbreak of clinical mastitis in a dairy herd in northern China. A total of 182 (80.2%) lactating cows had clinical mastitis with severe inflammation and firmness of the udder, reduced milk production, and anorexia, with no apparent clinical response to common antibiotics. Out of 22 mastitic milk samples submitted to our laboratory, 12 N. cyriacigeorgica were isolated and characterized using standard microbiological analysis, 16S rRNA gene sequencing, random amplified polymorphic DNA PCR analysis, biochemical assays, and antibiotic susceptibility testing. Additionally, in vivo experiments were done to determine pathogenicity of these clinical mastitis isolates. All isolates were resistant to ampicillin, amoxicillin-clavulanic acid, ciprofloxacin, minocycline, rifampicin, and aminoglycosides (type VI pattern). Additionally, intramammary inoculation of mice with N. cyriacigeorgica caused chronic inflammatory changes, including hyperemia, edema, and infiltration of lymphocytes and neutrophils, as well as hyperplasia of lymph nodules in mammary glands. Therefore, we concluded that N. cyriacigeorgica was involved in the current outbreak of mastitis. To our best knowledge, this is the first report to characterize N. cyriacigeorgica isolated from cases of bovine mastitis in China. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  18. Sclerotinia sclerotiorum (Lib.) de Bary: biology and molecular traits of a cosmopolitan pathogen

    NARCIS (Netherlands)

    Bolton, M.D.; Thomma, B.P.H.J.; Nelson, B.D.

    2006-01-01

    Sclerotinia sclerotiorum (Lib.) de Bary is a necrotrophic fungal pathogen causing disease in a wide range of plants. This review summarizes current knowledge of mechanisms employed by the fungus to parasitize its host with emphasis on biology, physiology and molecular aspects of pathogenicity. In

  19. NLRP1 haplotypes associated with vitiligo and autoimmunity increase interleukin-1beta processing via the NLRP1 inflammasome

    NARCIS (Netherlands)

    Levandowski, C.B.; Mailloux, C.M.; Ferrara, T.M.; Gowan, K.; Ben, S. van der; Jin, Y.; McFann, K.K.; Holland, P.J.; Fain, P.R.; Dinarello, C.A.; Spritz, R.A.

    2013-01-01

    Nuclear localization leucine-rich-repeat protein 1 (NLRP1) is a key regulator of the innate immune system, particularly in the skin where, in response to molecular triggers such as pathogen-associated or damage-associated molecular patterns, the NLRP1 inflammasome promotes caspase-1-dependent

  20. Inventory and update on argasid ticks and associated pathogens in Algeria

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    I. Lafri

    2018-05-01

    Full Text Available Argasid ticks include vectors of relapsing fevers caused by Borrelia spp. in humans, and they can transmit arboviruses and other bacterial pathogens. Knowledge about soft ticks (Ixodida: Argasidae in Algeria is incomplete, and distribution data need to be updated. Here we report a series of entomologic investigations that we conducted in five different areas in Algeria between 2012 and 2015. Ticks were identified by entomologic keys and molecular tools (16S rRNA gene. Six distinct species belonging to two genera were identified, including Ornithodoros capensis s.s., Ornithodoros rupestris, Ornithodoros occidentalis, Ornithodoros erraticus, Ornithodoros sonrai and Argas persicus. The present study highlights the distribution of soft ticks, the establishment of an update inventory with nine species and associated pathogens detected in argasid ticks in Algeria. Keywords: Argasid, Borrelia, Ornithodoros, Rickettsia

  1. Pathogenic, morphological and molecular characteristics of Alternaria Tenuissima from soybean

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    Jasnić Stevan M.

    2011-01-01

    Full Text Available During 2008 and 2009 phytopathological isolations were done from soybean plants and seed samples from several localities in Serbia. A total of 19 isolates of Alternaria spp. were isolated, 13 from the seed and 3 from both leaf and stem. In order to determine and characterize isolates, cultural, morphological, molecular and pathogenic characteristics were thoroughly investigated. The slowest growth of the examined isolates was noted on Malt agar (MA with average colony diameter of 42.9 mm after 7 days of incubation. On other two media (V8 and PCA, colony growth was uniform and faster, with average diameter of 66.8 mm and 66.1 mm, respectively. Isolates of fungi form unbranched or poorly branched conidial chains on short unbranched conidiophores. Conidia are dark in colour, multicellular with transverse and longitudinal septae. They are of different size regarding the place of formation in the chain. Based on these characteristics, the tested isolates were determined as Alternaria tenuissima. Molecular identification with sequencing of ITS1-5.8S-ITS2 rDNA verified that investigated isolates belong to Alternaria tenuissima group. Pathogenicity test proved that all isolates were more or less virulent to soybean seed (12.5% to 40% of rotten seeds, while pathogenicity on plants was poorly expressed.

  2. Preliminary molecular characterization of the human pathogen Angiostrongylus cantonensis

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    He Ai

    2009-10-01

    Full Text Available Abstract Background Human angiostrongyliasis is an emerging food-borne public health problem, with the number of cases increasing worldwide, especially in mainland China. Angiostrongylus cantonensis is the causative agent of this severe disease. However, little is known about the genetics and basic biology of A. cantonensis. Results A cDNA library of A. cantonensis fourth-stage larvae was constructed, and ~1,200 clones were sequenced. Bioinformatic analyses revealed 378 cDNA clusters, 54.2% of which matched known genes at a cutoff expectation value of 10-20. Of these 378 unique cDNAs, 168 contained open reading frames encoding proteins containing an average of 238 amino acids. Characterization of the functions of these encoded proteins by Gene Ontology analysis showed enrichment in proteins with binding and catalytic activity. The observed pattern of enzymes involved in protein metabolism, lipid metabolism and glycolysis may reflect the central nervous system habitat of this pathogen. Four proteins were tested for their immunogenicity using enzyme-linked immunosorbent assays and histopathological examinations. The specificity of each of the four proteins was superior to that of crude somatic and excretory/secretory antigens of larvae, although their sensitivity was relatively low. We further showed that mice immunized with recombinant cystatin, a product of one of the four cDNA candidate genes, were partially protected from A. cantonensis infection. Conclusion The data presented here substantially expand the available genetic information about the human pathogen A. cantonensis, and should be a significant resource for angiostrongyliasis researchers. As such, this work serves as a starting point for molecular approaches for diagnosing and controlling human angiostrongyliasis.

  3. Molecular investigation of tick-borne pathogens in dogs from Luanda, Angola.

    Science.gov (United States)

    Cardoso, Luís; Oliveira, Ana Cristina; Granada, Sara; Nachum-Biala, Yaarit; Gilad, Matan; Lopes, Ana Patrícia; Sousa, Sérgio Ramalho; Vilhena, Hugo; Baneth, Gad

    2016-05-10

    No molecular data have been available on tick-borne pathogens that infect dogs from Angola. The occurrence of agents from the genera Anaplasma, Babesia, Ehrlichia and Hepatozoon was assessed in 103 domestic dogs from Luanda, by means of the polymerase chain reaction (PCR) and DNA sequence analysis. Forty-six dogs (44.7 %) were positive for at least one pathogen. Twenty-one animals (20.4 %) were found infected with Anaplasma platys, 18 (17.5 %) with Hepatozoon canis, six (5.8 %) with Ehrlichia canis, six (5.8 %) with Babesia vogeli, one (1.0 %) with Babesia gibsoni and one (1.0 %) with an unnamed Babesia sp. The molecular frequency of single infections taken together was 37.9 % and that of co-infections with several combinations of two pathogens accounted for 6.8 % of the animals. This is the first report of A. platys, B. vogeli, B. gibsoni, E. canis and H. canis infections diagnosed by PCR in domestic dogs from Angola. The present study provides evidence that dogs in Luanda are widely exposed to, and at risk of becoming infected with, tick-borne pathogens. Further investigation is needed, including a larger number of animals, canine populations from other cities and provinces of the country, as well as potential vector ticks, aiming at better characterizing and controlling canine vector-borne diseases in Angola.

  4. Molecular Biosensors for Electrochemical Detection of Infectious Pathogens in Liquid Biopsies: Current Trends and Challenges.

    Science.gov (United States)

    Campuzano, Susana; Yáñez-Sedeño, Paloma; Pingarrón, José Manuel

    2017-11-03

    Rapid and reliable diagnosis of infectious diseases caused by pathogens, and timely initiation of appropriate treatment are critical determinants to promote optimal clinical outcomes and general public health. Conventional in vitro diagnostics for infectious diseases are time-consuming and require centralized laboratories, experienced personnel and bulky equipment. Recent advances in electrochemical affinity biosensors have demonstrated to surpass conventional standards in regards to time, simplicity, accuracy and cost in this field. The tremendous potential offered by electrochemical affinity biosensors to detect on-site infectious pathogens at clinically relevant levels in scarcely treated body fluids is clearly stated in this review. The development and application of selected examples using different specific receptors, assay formats and electrochemical approaches focusing on the determination of specific circulating biomarkers of different molecular (genetic, regulatory and functional) levels associated with bacterial and viral pathogens are critically discussed. Existing challenges still to be addressed and future directions in this rapidly advancing and highly interesting field are also briefly pointed out.

  5. Molecular Epidemiologic Typing Systems of Bacterial Pathogens: Current Issues and Perpectives

    Directory of Open Access Journals (Sweden)

    Struelens Marc J

    1998-01-01

    Full Text Available The epidemiologic typing of bacterial pathogens can be applied to answer a number of different questions: in case of outbreak, what is the extent and mode of transmission of epidemic clone(s ? In case of long-term surveillance, what is the prevalence over time and the geographic spread of epidemic and endemic clones in the population? A number of molecular typing methods can be used to classify bacteria based on genomic diversity into groups of closely-related isolates (presumed to arise from a common ancestor in the same chain of transmission and divergent, epidemiologically-unrelated isolates (arising from independent sources of infection. Ribotyping, IS-RFLP fingerprinting, macrorestriction analysis of chromosomal DNA and PCR-fingerprinting using arbitrary sequence or repeat element primers are useful methods for outbreak investigations and regional surveillance. Library typing systems based on multilocus sequence-based analysis and strain-specific probe hybridization schemes are in development for the international surveillance of major pathogens like Mycobacterium tuberculosis. Accurate epidemiological interpretation of data obtained with molecular typing systems still requires additional research on the evolution rate of polymorphic loci in bacterial pathogens.

  6. Molecular prophage typing of avian pathogenic Escherichia coli.

    Science.gov (United States)

    Kwon, Hyuk-Joon; Seong, Won-Jin; Kim, Jae-Hong

    2013-03-23

    Escherichia coli prophages confer virulence and resistance to physico-chemical, nutritional, and antibiotic stresses on their hosts, and they enhance the evolution of E. coli. Thus, studies on profiles of E. coli prophages are valuable to understand the population structure and evolution of E. coli pathogenicity. Large terminase genes participate in phage genome packaging and are one of the cornerstones for the identification of prophages. Thus, we designed primers to detect 16 types of large terminase genes and analyzed the genomes of 48 E. coli and Shigella reference strains for the prophage markers. We also investigated the distribution of the 16 prophage markers among 92 avian pathogenic E. coli (APEC) strains. APEC strains were classified into 61 prophage types (PPTs). Each strain was different from the reference strains as measured by the PPTs and from the frequency of each prophage marker. Investigation of the distribution of prophage-related serum resistance (bor), toxin (stx1 and cdtI), and T3SS effector (lom, espK, sopE, nleB, and ospG) genes revealed the presence of bor (44.1%), lom (95.5%) and cdtI (9.1%) in APEC strains with related prophages. Therefore, the molecular prophage typing method may be useful to understand population structure and evolution of E. coli pathogenicity, and further studies on the mobility of the prophages and the roles of virulence genes in APEC pathogenicity may be valuable. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Antimicrobial-Resistant Pathogens Associated With Healthcare-Associated Infections: Summary of Data Reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2011-2014.

    Science.gov (United States)

    Weiner, Lindsey M; Webb, Amy K; Limbago, Brandi; Dudeck, Margaret A; Patel, Jean; Kallen, Alexander J; Edwards, Jonathan R; Sievert, Dawn M

    2016-11-01

    OBJECTIVE To describe antimicrobial resistance patterns for healthcare-associated infections (HAIs) that occurred in 2011-2014 and were reported to the Centers for Disease Control and Prevention's National Healthcare Safety Network. METHODS Data from central line-associated bloodstream infections, catheter-associated urinary tract infections, ventilator-associated pneumonias, and surgical site infections were analyzed. These HAIs were reported from acute care hospitals, long-term acute care hospitals, and inpatient rehabilitation facilities. Pooled mean proportions of pathogens that tested resistant (or nonsusceptible) to selected antimicrobials were calculated by year and HAI type. RESULTS Overall, 4,515 hospitals reported that at least 1 HAI occurred in 2011-2014. There were 408,151 pathogens from 365,490 HAIs reported to the National Healthcare Safety Network, most of which were reported from acute care hospitals with greater than 200 beds. Fifteen pathogen groups accounted for 87% of reported pathogens; the most common included Escherichia coli (15%), Staphylococcus aureus (12%), Klebsiella species (8%), and coagulase-negative staphylococci (8%). In general, the proportion of isolates with common resistance phenotypes was higher among device-associated HAIs compared with surgical site infections. Although the percent resistance for most phenotypes was similar to earlier reports, an increase in the magnitude of the resistance percentages among E. coli pathogens was noted, especially related to fluoroquinolone resistance. CONCLUSION This report represents a national summary of antimicrobial resistance among select HAIs and phenotypes. The distribution of frequent pathogens and some resistance patterns appear to have changed from 2009-2010, highlighting the need for continual, careful monitoring of these data across the spectrum of HAI types. Infect Control Hosp Epidemiol 2016;1-14.

  8. Autophagic clearance of bacterial pathogens: molecular recognition of intracellular microorganisms.

    Science.gov (United States)

    Pareja, Maria Eugenia Mansilla; Colombo, Maria I

    2013-01-01

    Autophagy is involved in several physiological and pathological processes. One of the key roles of the autophagic pathway is to participate in the first line of defense against the invasion of pathogens, as part of the innate immune response. Targeting of intracellular bacteria by the autophagic machinery, either in the cytoplasm or within vacuolar compartments, helps to control bacterial proliferation in the host cell, controlling also the spreading of the infection. In this review we will describe the means used by diverse bacterial pathogens to survive intracellularly and how they are recognized by the autophagic molecular machinery, as well as the mechanisms used to avoid autophagic clearance.

  9. Molecular Mechanisms of Innate Immune Inhibition by Non-Segmented Negative-Sense RNA Viruses

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Srirupa; Basler, Christopher F.; Amarasinghe, Gaya K.; Leung, Daisy W.

    2016-08-01

    The host innate immune system serves as the first line of defense against viral infections. Germline-encoded pattern recognition receptors detect molecular patterns associated with pathogens and activate innate immune responses. Of particular relevance to viral infections are those pattern recognition receptors that activate type I interferon responses, which establish an antiviral state. The order Mononegavirales is composed of viruses that possess single-stranded, non-segmented negative-sense (NNS) RNA genomes and are important human pathogens that consistently antagonize signaling related to type I interferon responses. NNS viruses have limited encoding capacity compared to many DNA viruses, and as a likely consequence, most open reading frames encode multifunctional viral proteins that interact with host factors in order to evade host cell defenses while promoting viral replication. In this review, we will discuss the molecular mechanisms of innate immune evasion by select NNS viruses. A greater understanding of these interactions will be critical in facilitating the development of effective therapeutics and viral countermeasures.

  10. Molecular characterization of double-stranded RNA virus in Trichomonas vaginalis Egyptian isolates and its association with pathogenicity.

    Science.gov (United States)

    El-Gayar, Eman K; Mokhtar, Amira B; Hassan, Wael A

    2016-10-01

    Trichomoniasis is a common human sexually transmitted infection caused by Trichomonas vaginalis. The parasite can be infected with double-stranded RNA viruses (TVV). This viral infection may have important implications on trichomonal virulence and disease pathogenesis. This study aimed to determine the prevalence of T. vaginalis virus among isolates obtained from infected (symptomatic and asymptomatic) women in Ismailia City, Egypt, and to correlate the virus-infected isolates with the clinical manifestations of patients. In addition, the pathogenicity of TVV infected isolates on mice was also evaluated. T. vaginalis isolates were obtained from symptomatic and asymptomatic female patients followed by axenic cultivation in Diamond's TYM medium. The presence of T. vaginalis virus was determined from total extraction of nucleic acids (DNA-RNA) followed by reverse transcriptase-PCR. Representative samples were inoculated intraperitoneally in female albino/BALB mice to assess the pathogenicity of different isolates. A total of 110 women were examined; 40 (36.3 %) samples were positive for T. vaginalis infection. Of these 40 isolates, 8 (20 %) were infected by TVV. Five isolates contained TVV-2 virus species, and the remaining three isolates were infected withTVV-4 variant. A significant association was found between the presence of TVV and particular clinical manifestations of trichomoniasis. Experimental mice infection showed varying degrees of pathogenicity. This is the first report on T. vaginalis infection by TVV in Egypt. The strong association detected between TVV and particular clinical features of trichomoniasis and also the degree of pathogenicity in experimentally infected mice may indicate a possible clinical significance of TVV infection of T. vaginalis isolates.

  11. Determining risk for severe leptospirosis by molecular analysis of environmental surface waters for pathogenic Leptospira.

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    Christian A Ganoza

    2006-08-01

    Full Text Available Although previous data indicate that the overall incidence of human leptospirosis in the Peruvian Amazon is similar in urban and rural sites, severe leptospirosis has been observed only in the urban context. As a potential explanation for this epidemiological observation, we tested the hypothesis that concentrations of more virulent Leptospira would be higher in urban than in rural environmental surface waters.A quantitative real-time PCR assay was used to compare levels of Leptospira in urban and rural environmental surface waters in sites in the Peruvian Amazon region of Iquitos. Molecular taxonomic analysis of a 1,200-bp segment of the leptospiral 16S ribosomal RNA gene was used to identify Leptospira to the species level. Pathogenic Leptospira species were found only in urban slum water sources (Fisher's exact test; p = 0.013. The concentration of pathogen-related Leptospira was higher in urban than rural water sources (approximately 10(3 leptospires/ml versus 0.5 x 10(2 leptospires/ml; F = 8.406, p < 0.05. Identical 16S rRNA gene sequences from Leptospira interrogans serovar Icterohaemorrhagiae were found in urban slum market area gutter water and in human isolates, suggesting a specific mode of transmission from rats to humans. In a prospective, population-based study of patients presenting with acute febrile illness, isolation of L. interrogans-related leptospires from humans was significantly associated with urban acquisition (75% of urban isolates; human isolates of other leptospiral species were associated with rural acquisition (78% of rural isolates (chi-square analysis; p < 0.01. This distribution of human leptospiral isolates mirrored the distribution of leptospiral 16S ribosomal gene sequences in urban and rural water sources.Our findings data support the hypothesis that urban severe leptospirosis in the Peruvian Amazon is associated with higher concentrations of more pathogenic leptospires at sites of exposure and transmission

  12. Gorilla gorilla gorilla gut: a potential reservoir of pathogenic bacteria as revealed using culturomics and molecular tools.

    Science.gov (United States)

    Bittar, Fadi; Keita, Mamadou B; Lagier, Jean-Christophe; Peeters, Martine; Delaporte, Eric; Raoult, Didier

    2014-11-24

    Wild apes are considered to be the most serious reservoir and source of zoonoses. However, little data are available about the gut microbiota and pathogenic bacteria in gorillas. For this propose, a total of 48 fecal samples obtained from 21 Gorilla gorilla gorilla individuals (as revealed via microsatellite analysis) were screened for human bacterial pathogens using culturomics and molecular techniques. By applying culturomics to one index gorilla and using specific media supplemented by plants, we tested 12,800 colonies and identified 147 different bacterial species, including 5 new species. Many opportunistic pathogens were isolated, including 8 frequently associated with human diseases; Mycobacterium bolletii, Proteus mirabilis, Acinetobacter baumannii, Klebsiella pneumoniae, Serratia marcescens, Escherichia coli, Staphylococcus aureus and Clostridium botulinum. The genus Treponema accounted for 27.4% of the total reads identified at the genus level via 454 pyrosequencing. Using specific real-time PCR on 48 gorilla fecal samples, in addition to classical human pathogens, we also observed the fastidious bacteria Bartonella spp. Borrelia spp., Coxiella burnetii and Tropheryma whipplei in the gorilla population. We estimated that the prevalence of these pathogens vary between 4.76% and 85.7%. Therefore, gorillas share many bacterial pathogens with humans suggesting that they could be a reservoir for their emergence.

  13. Molecular signatures of nicotinoid-pathogen synergy in the termite gut.

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    Ruchira Sen

    Full Text Available Previous studies in lower termites revealed unexpected synergies between nicotinoid insecticides and fungal entomopathogens. The present study investigated molecular mechanisms of nicotinoid-pathogen synergy in the lower termite Reticulitermes flavipes, using the nicotinoid, imidacloprid, in combination with fungal and bacterial entomopathogens. Particular focus was placed on metatranscriptome composition and microbial dynamics in the symbiont-rich termite gut, which houses diverse mixes of protists and bacteria. cDNA microarrays containing a mix of host and protist symbiont oligonucleotides were used to simultaneously assess termite and protist gene expression. Five treatments were compared that included single challenges with sublethal doses of fungi (Metharizium anisopliae, bacteria (Serratia marcescens or imidacloprid, and dual challenges with fungi + imidacloprid or bacteria + imidacloprid. Our findings point towards protist dysbiosis and compromised social behavior, rather than suppression of stereotypical immune defense mechanisms, as the dominant factors underlying nicotinoid-pathogen synergy in termites. Also, greater impacts observed for the fungal pathogen than for the bacterial pathogen suggest that the rich bacterial symbiont community in the R. flavipes gut (>5000 species-level phylotypes exists in an ecological balance that effectively excludes exogenous bacterial pathogens. These findings significantly advance our understanding of antimicrobial defenses in this important eusocial insect group, as well as provide novel insights into how nicotinoids can exert deleterious effects on social insect colonies.

  14. Molecular techniques for detection and identification of pathogens in food: advantages and limitations

    OpenAIRE

    Palomino-Camargo, Carolina; Instituto de Ciencia y Tecnología de Alimentos, Facultad de Ciencias, Universidad Central de Venezuela. Caracas, Venezuela. Magíster en Ciencia y Tecnología de los Alimentos licenciada en Biología; González-Muñoz, Yuniesky; Instituto de Ciencia y Tecnología de Alimentos, Facultad de Ciencias, Universidad Central de Venezuela. Caracas, Venezuela. Ministerio del Poder Popular para la Alimentación. Caracas, Venezuela. licenciado en Ciencias de los Alimentos.

    2014-01-01

    Foodborne diseases, caused by pathogenic microorganisms, are a major public health problem worldwide. Microbiological methods commonly used in the detection of these foodborne pathogens are laborious and time consuming. This situation, coupled with the demand for immediate results and with technological advances, has led to the development of a wide range of rapid methods in recent decades. On this basis, this review describes the advantages and limitations of the main molecular methods used ...

  15. A Systems Biology Approach to the Coordination of Defensive and Offensive Molecular Mechanisms in the Innate and Adaptive Host-Pathogen Interaction Networks.

    Science.gov (United States)

    Wu, Chia-Chou; Chen, Bor-Sen

    2016-01-01

    Infected zebrafish coordinates defensive and offensive molecular mechanisms in response to Candida albicans infections, and invasive C. albicans coordinates corresponding molecular mechanisms to interact with the host. However, knowledge of the ensuing infection-activated signaling networks in both host and pathogen and their interspecific crosstalk during the innate and adaptive phases of the infection processes remains incomplete. In the present study, dynamic network modeling, protein interaction databases, and dual transcriptome data from zebrafish and C. albicans during infection were used to infer infection-activated host-pathogen dynamic interaction networks. The consideration of host-pathogen dynamic interaction systems as innate and adaptive loops and subsequent comparisons of inferred innate and adaptive networks indicated previously unrecognized crosstalk between known pathways and suggested roles of immunological memory in the coordination of host defensive and offensive molecular mechanisms to achieve specific and powerful defense against pathogens. Moreover, pathogens enhance intraspecific crosstalk and abrogate host apoptosis to accommodate enhanced host defense mechanisms during the adaptive phase. Accordingly, links between physiological phenomena and changes in the coordination of defensive and offensive molecular mechanisms highlight the importance of host-pathogen molecular interaction networks, and consequent inferences of the host-pathogen relationship could be translated into biomedical applications.

  16. Endoplasmic reticulum-dependent redox reactions control endoplasmic reticulum-associated degradation and pathogen entry.

    Science.gov (United States)

    Walczak, Christopher P; Bernardi, Kaleena M; Tsai, Billy

    2012-04-15

    Protein misfolding within the endoplasmic reticulum (ER) is managed by an ER quality control system that retro-translocates aberrant proteins into the cytosol for proteasomal destruction. This process, known as ER-associated degradation, utilizes the action of ER redox enzymes to accommodate the disulfide-bonded nature of misfolded proteins. Strikingly, various pathogenic viruses and toxins co-opt these redox components to reach the cytosol during entry. These redox factors thus regulate critical cellular homeostasis and host-pathogen interactions. Recent studies identify specific members of the protein disulfide isomerase (PDI) family, which use their chaperone and catalytic activities, in engaging both misfolded ER proteins and pathogens. The precise molecular mechanism by which a dedicated PDI family member disrupts the disulfide bonds in the misfolded ER proteins and pathogens, as well as how they act to unfold these substrates to promote their ER-to-cytosol membrane transport, remain poorly characterized. How PDI family members distinguish folded versus misfolded ER substrates remains enigmatic. What physical characteristics surrounding a substrate's disulfide bond instruct PDI that it is mispaired or native? For the pathogens, as their disulfide bonds normally serve a critical role in providing physical support, what conformational changes experienced in the host enable their disulfide bonds to be disrupted? A combination of more rigorous biochemical and high-resolution structural studies should begin to address these questions.

  17. Molecular Detection and Characterization of Tick-borne Pathogens in Dogs and Ticks from Nigeria

    Science.gov (United States)

    Kamani, Joshua; Baneth, Gad; Mumcuoglu, Kosta Y.; Waziri, Ndadilnasiya E.; Eyal, Osnat; Guthmann, Yifat; Harrus, Shimon

    2013-01-01

    Background Only limited information is currently available on the prevalence of vector borne and zoonotic pathogens in dogs and ticks in Nigeria. The aim of this study was to use molecular techniques to detect and characterize vector borne pathogens in dogs and ticks from Nigeria. Methodology/Principal Findings Blood samples and ticks (Rhipicephalus sanguineus, Rhipicephalus turanicus and Heamaphysalis leachi) collected from 181 dogs from Nigeria were molecularly screened for human and animal vector-borne pathogens by PCR and sequencing. DNA of Hepatozoon canis (41.4%), Ehrlichia canis (12.7%), Rickettsia spp. (8.8%), Babesia rossi (6.6%), Anaplasma platys (6.6%), Babesia vogeli (0.6%) and Theileria sp. (0.6%) was detected in the blood samples. DNA of E. canis (23.7%), H. canis (21.1%), Rickettsia spp. (10.5%), Candidatus Neoehrlichia mikurensis (5.3%) and A. platys (1.9%) was detected in 258 ticks collected from 42 of the 181 dogs. Co- infections with two pathogens were present in 37% of the dogs examined and one dog was co-infected with 3 pathogens. DNA of Rickettsia conorii israelensis was detected in one dog and Rhipicephalus sanguineus tick. DNA of another human pathogen, Candidatus N. mikurensis was detected in Rhipicephalus sanguineus and Heamaphysalis leachi ticks, and is the first description of Candidatus N. mikurensis in Africa. The Theileria sp. DNA detected in a local dog in this study had 98% sequence identity to Theileria ovis from sheep. Conclusions/Significance The results of this study indicate that human and animal pathogens are abundant in dogs and their ticks in Nigeria and portray the potential high risk of human exposure to infection with these agents. PMID:23505591

  18. Molecular detection and characterization of tick-borne pathogens in dogs and ticks from Nigeria.

    Directory of Open Access Journals (Sweden)

    Joshua Kamani

    Full Text Available BACKGROUND: Only limited information is currently available on the prevalence of vector borne and zoonotic pathogens in dogs and ticks in Nigeria. The aim of this study was to use molecular techniques to detect and characterize vector borne pathogens in dogs and ticks from Nigeria. METHODOLOGY/PRINCIPAL FINDINGS: Blood samples and ticks (Rhipicephalus sanguineus, Rhipicephalus turanicus and Heamaphysalis leachi collected from 181 dogs from Nigeria were molecularly screened for human and animal vector-borne pathogens by PCR and sequencing. DNA of Hepatozoon canis (41.4%, Ehrlichia canis (12.7%, Rickettsia spp. (8.8%, Babesia rossi (6.6%, Anaplasma platys (6.6%, Babesia vogeli (0.6% and Theileria sp. (0.6% was detected in the blood samples. DNA of E. canis (23.7%, H. canis (21.1%, Rickettsia spp. (10.5%, Candidatus Neoehrlichia mikurensis (5.3% and A. platys (1.9% was detected in 258 ticks collected from 42 of the 181 dogs. Co- infections with two pathogens were present in 37% of the dogs examined and one dog was co-infected with 3 pathogens. DNA of Rickettsia conorii israelensis was detected in one dog and Rhipicephalus sanguineus tick. DNA of another human pathogen, Candidatus N. mikurensis was detected in Rhipicephalus sanguineus and Heamaphysalis leachi ticks, and is the first description of Candidatus N. mikurensis in Africa. The Theileria sp. DNA detected in a local dog in this study had 98% sequence identity to Theileria ovis from sheep. CONCLUSIONS/SIGNIFICANCE: The results of this study indicate that human and animal pathogens are abundant in dogs and their ticks in Nigeria and portray the potential high risk of human exposure to infection with these agents.

  19. Molecular Diversity of Anthracnose Pathogen Populations Associated with UK Strawberry Production Suggests Multiple Introductions of Three Different Colletotrichum Species

    Science.gov (United States)

    Baroncelli, Riccardo; Zapparata, Antonio; Sarrocco, Sabrina; Sukno, Serenella A.; Lane, Charles R.; Thon, Michael R.; Vannacci, Giovanni; Holub, Eric; Sreenivasaprasad, Surapareddy

    2015-01-01

    Fragaria × ananassa (common name: strawberry) is a globally cultivated hybrid species belonging to Rosaceae family. Colletotrichum acutatum sensu lato (s.l.) is considered to be the second most economically important pathogen worldwide affecting strawberries. A collection of 148 Colletotrichum spp. isolates including 67 C. acutatum s.l. isolates associated with the phytosanitary history of UK strawberry production were used to characterize multi-locus genetic variation of this pathogen in the UK, relative to additional reference isolates that represent a worldwide sampling of the diversity of the fungus. The evidence indicates that three different species C. nymphaeae, C. godetiae and C. fioriniae are associated with strawberry production in the UK, which correspond to previously designated genetic groups A2, A4 and A3, respectively. Among these species, 12 distinct haplotypes were identified suggesting multiple introductions into the country. A subset of isolates was also used to compare aggressiveness in causing disease on strawberry plants and fruits. Isolates belonging to C. nymphaeae, C. godetiae and C. fioriniae representative of the UK anthracnose pathogen populations showed variation in their aggressiveness. Among the three species, C. nymphaeae and C. fioriniae appeared to be more aggressive compared to C. godetiae. This study highlights the genetic and pathogenic heterogeneity of the C. acutatum s.l. populations introduced into the UK linked to strawberry production. PMID:26086351

  20. Molecular Diversity of Anthracnose Pathogen Populations Associated with UK Strawberry Production Suggests Multiple Introductions of Three Different Colletotrichum Species.

    Directory of Open Access Journals (Sweden)

    Riccardo Baroncelli

    Full Text Available Fragaria × ananassa (common name: strawberry is a globally cultivated hybrid species belonging to Rosaceae family. Colletotrichum acutatum sensu lato (s.l. is considered to be the second most economically important pathogen worldwide affecting strawberries. A collection of 148 Colletotrichum spp. isolates including 67 C. acutatum s.l. isolates associated with the phytosanitary history of UK strawberry production were used to characterize multi-locus genetic variation of this pathogen in the UK, relative to additional reference isolates that represent a worldwide sampling of the diversity of the fungus. The evidence indicates that three different species C. nymphaeae, C. godetiae and C. fioriniae are associated with strawberry production in the UK, which correspond to previously designated genetic groups A2, A4 and A3, respectively. Among these species, 12 distinct haplotypes were identified suggesting multiple introductions into the country. A subset of isolates was also used to compare aggressiveness in causing disease on strawberry plants and fruits. Isolates belonging to C. nymphaeae, C. godetiae and C. fioriniae representative of the UK anthracnose pathogen populations showed variation in their aggressiveness. Among the three species, C. nymphaeae and C. fioriniae appeared to be more aggressive compared to C. godetiae. This study highlights the genetic and pathogenic heterogeneity of the C. acutatum s.l. populations introduced into the UK linked to strawberry production.

  1. Pathogenic Leptospira spp. in bats: Molecular investigation in Southern Brazil.

    Science.gov (United States)

    Mayer, Fabiana Quoos; Dos Reis, Emily Marques; Bezerra, André Vinícius Andrade; Cerva, Cristine; Rosa, Júlio; Cibulski, Samuel Paulo; Lima, Francisco Esmaile Sales; Pacheco, Susi Missel; Rodrigues, Rogério Oliveira

    2017-06-01

    The present study aimed to investigate the frequency of pathogenic Leptospira spp. in Brazilian bats and to determine possible risk factors associated to it. Ninety two bats of 12 species were evaluated. Whole genomic DNA from kidneys was extracted and real-time PCR specific to pathogenic Leptospira spp. was applied. Association between the frequency of specimens positive for Leptospira spp. and sex, age, bat species or family, season of collection, geographic localization and feeding habits was evaluated. The results showed that 39.13% of analyzed bats were found positive for Leptospira spp. Nine bat species had at least one positive result. There was no association among the evaluated variables and frequency of pathogenic Leptospira spp. Although the limitations due to lack of Leptospira spp. isolation, leptospiral carriage was demonstrated in bats of different species from southern Brazil, which reinforces the need for surveillance of infectious agents in wild animals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Molecular identification of Lactobacillus spp. associated with puba, a Brazilian fermented cassava food

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    S.M. Crispim

    2013-01-01

    Full Text Available Puba or carimã is a Brazilian staple food obtained by spontaneous submerged fermentation of cassava roots. A total of 116 lactobacilli and three cocci isolates from 20 commercial puba samples were recovered on de Man, Rogosa and Sharpe agar (MRS; they were characterized for their antagonistic activity against foodborne pathogens and identified taxonomically by classical and molecular methods. In all samples, lactic acid bacteria were recovered as the dominant microbiota (7.86 ± 0.41 log10 CFU/g. 16S-23S rRNA ARDRA pattern assigned 116 isolates to the Lactobacillus genus, represented by the species Lactobacillus fermentum (59 isolates, Lactobacillus delbrueckii (18 isolates, Lactobacillus casei (9 isolates, Lactobacillus reuteri (6 isolates, Lactobacillus brevis (3 isolates, Lactobacillus gasseri (2 isolates, Lactobacillus nagelii (1 isolate, and Lactobacillus plantarum group (18 isolates. recA gene-multiplex PCR analysis revealed that L. plantarum group isolates belonged to Lactobacillus plantarum (15 isolates and Lactobacillus paraplantarum (3 isolates. Genomic diversity was investigated by molecular typing with rep (repetitive sequence-based PCR using the primer ERIC2 (enterobacterial repetitive intergenic consensus. The Lactobacillus isolates exhibited genetic heterogeneity and species-specific fingerprint patterns. All the isolates showed antagonistic activity against the foodborne pathogenic bacteria tested. This antibacterial effect was attributed to acid production, except in the cases of three isolates that apparently produced bacteriocin-like inhibitory substances. This study provides the first insight into the genetic diversity of Lactobacillus spp. of puba.

  3. The pathogenic persona of community-associated oral streptococci.

    Science.gov (United States)

    Whitmore, Sarah E; Lamont, Richard J

    2011-07-01

    The mitis group streptococci (MGS) are widespread in the oral cavity and are traditionally associated with oral health. However, these organisms have many attributes that contribute to the development of pathogenic oral communities. MGS adhere rapidly to saliva-coated tooth surfaces, thereby providing an attachment substratum for more overtly pathogenic organisms such as Porphyromonas gingivalis, and the two species assemble into heterotypic communities. Close physical association facilitates physiologic support, and pathogens such as Aggregatibacter actinomycetemcomitans display resource partitioning to favour carbon sources generated by streptococcal metabolism. MGS exchange information with community members through a number of interspecies signalling systems including AI-2 and contact dependent mechanisms. Signal transduction systems induced in P. gingivalis are based on protein dephosphorylation mediated by the tyrosine phosphatase Ltp1, and converge on a LuxR-family transcriptional regulator, CdhR. Phenotypic responses in P. gingivalis include regulation of hemin uptake systems and gingipain activity, processes that are intimately linked to the virulence of the organism. Furthermore, communities of S. gordonii with P. gingivalis or with A. actinomycetemcomitans are more pathogenic in animal models than the constituent species alone. We propose that MGS should be considered accessory pathogens, organisms whose pathogenic potential only becomes evident in the context of a heterotypic microbial community. © 2011 Blackwell Publishing Ltd.

  4. Pathogens associated with persistent diarrhoea in children in low and middle income countries: systematic review

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    Hart C Anthony

    2009-06-01

    Full Text Available Abstract Background Persistent diarrhoea in children is a common problem in low and middle income countries. To help target appropriate treatment for specific pathogens in the absence of diagnostic tests, we systematically reviewed pathogens most commonly associated with persistent diarrhoea in children. Methods We sought all descriptive studies of pathogens in the stool of children with diarrhoea of over 14 days duration in low and middle income countries with a comprehensive search of the MEDLINE, EMBASE, LILACS and WEB OF SCIENCE databases. We described the study designs and populations, assessed the quality of the laboratory tests, and extracted and summarised data on pathogens. For Escherichia coli, we calculated high and low prevalence estimates of all enteropathic types combined. Results across studies were compared for geographical patterns. Results Nineteen studies were included. Some used episodes of diarrhoea as the unit of analysis, others used children. The quality of reporting of laboratory procedures varied, and pathogens (particularly E. coli types were classified in different ways. As there were no apparent regional differences in pathogen prevalence, we aggregated data between studies to give a guide to overall prevalence. Enteropathic E. coli types were commonly found in children with persistent diarrhoea (up to 63%. Various other organisms, including viruses, bacteria and parasites, were detected but across all studies their prevalence was under 10%. However, these pathogens were also found in similar frequencies in children without diarrhoea. Conclusion A number of pathogens are commonly associated with persistent diarrhoea in children, but in children without diarrhoea the pathogens are found with similar frequencies. New research with carefully selected controls and standardised laboratory investigations across countries will help map causes and help explore effective options for presumptive treatment.

  5. Use of molecular hydrogen as an energy substrate by human pathogenic bacteria.

    Science.gov (United States)

    Maier, R J

    2005-02-01

    Molecular hydrogen is produced as a fermentation by-product in the large intestine of animals and its production can be correlated with the digestibility of the carbohydrates consumed. Pathogenic Helicobacter species (Helicobacter pylori and H. hepaticus) have the ability to use H(2) through a respiratory hydrogenase, and it was demonstrated that the gas is present in the tissues colonized by these pathogens (the stomach and the liver respectively of live animals). Mutant strains of H. pylori unable to use H(2) are deficient in colonizing mice compared with the parent strain. On the basis of available annotated gene sequence information, the enteric pathogen Salmonella, like other enteric bacteria, contains three putative membrane-associated H(2)-using hydrogenase enzymes. From the analysis of gene-targeted mutants it is concluded that each of the three membrane-bound hydrogenases of Salmonella enterica serovar Typhimurium are coupled with an H(2)-oxidizing respiratory pathway. From microelectrode probe measurements on live mice, H(2) could be detected at approx. 50 muM levels within the tissues (liver and spleen), which are colonized by Salmonella. The half-saturation affinity of whole cells of these pathogens for H(2) is much less than this, so it is expected that the (H(2)-utilizing) hydrogenase enzymes be saturated with the reducing substrate in vivo. All three enteric NiFe hydrogenase enzymes contribute to virulence of the bacterium in a typhoid fever-mouse model, and the combined removal of all three hydrogenases resulted in a strain that is avirulent and (in contrast with the parent strain) one that is not able to pass the intestinal tract to invade liver or spleen tissue. It is proposed that H(2) utilization and specifically its oxidation, coupled with a respiratory pathway, is required for energy production to permit growth and maintain efficient virulence of a number of pathogenic bacteria during infection of animals. These would be expected to include

  6. MICROBIAL PROFILE AND ANTIBIOTIC SUSCEPTIBILITY PATTERNS OF PATHOGENS CAUSING VENTILATOR- ASSOCIATED PNEUMONIA AT INTENSIVE CARE UNIT, SESTRE MILOSRDNICE UNIVERSITY HOSPITAL CENTER, ZAGREB, CROATIA.

    Science.gov (United States)

    Turković, Tihana Magdić; Grginić, Ana Gverić; Cucujić, Branka Đuras; Gašpar, Božena; Širanović, Mladen; Perić, Mladen

    2015-06-01

    Ventilator-associated pneumonia (VAP) is very common in many intensive care Units, but there are still many uncertainties about VAP, especially about the choice of initial empiric antibiotics. The incidence of specific pathogens with different susceptibility patterns causing VAP varies from hospital to hospital. This is the reason why empiric initial antibiotic treatment for VAP should be based not only on general guidelines (that recommend therapy according to the presence of risk factors for multidrug-resistant bacteria), but also on up-to-date information on local epidemiology. The aim of this study was to determine the microbial profile of pathogens causing VAP and their antibiotic susceptibility patterns. The study was conducted in the 15-bed surgical and neurosurgical Intensive Care Unit, Department of Anesthesiology and Intensive Care, Sestre milosrdnice University Hospital Center, Zagreb, Croatia. Retrospective data were collected from September 2009 to March 2013. All patients that developed VAP during the study period were eligible for the study. According to study results, the incidence of VAP was 29.4%. The most commonly isolated bacterium was Staphylococcus aureus (21.1%), followed by Pseudomonas aeruginosa (19.0%) and Acinetobacter species (13.6%). All Staphylococcus aureus isolates were susceptible to vancomycin and linezolid. Pseudomonas aeruginosa showed 100% susceptibility to cefepime and very high susceptibility to pip'eracillin-tazobactam (96%), ceftazidime (93%) and ciprofloxacin (89%). Ampicillin-sulbactam was highly effective for Acinetobacter species, showing resistance in only 8% of isolates. In conclusion, according to study data, appropriate empiric antibiotic therapy for patients with VAP without risk factors for multidrug-resistant bacteria is ceftriaxone and for patients with risk factors for multidrug-resistant bacteria ampicillin-sulbactam plus cefepime plus vancomycin or linezolid.

  7. Severity of Bovine Tuberculosis Is Associated with Co-Infection with Common Pathogens in Wild Boar

    Science.gov (United States)

    Risco, David; Serrano, Emmanuel; Fernández-Llario, Pedro; Cuesta, Jesús M.; Gonçalves, Pilar; García-Jiménez, Waldo L.; Martínez, Remigio; Cerrato, Rosario; Velarde, Roser; Gómez, Luis; Segalés, Joaquím; Hermoso de Mendoza, Javier

    2014-01-01

    Co-infections with parasites or viruses drive tuberculosis dynamics in humans, but little is known about their effects in other non-human hosts. This work aims to investigate the relationship between Mycobacterium bovis infection and other pathogens in wild boar (Sus scrofa), a recognized reservoir of bovine tuberculosis (bTB) in Mediterranean ecosystems. For this purpose, it has been assessed whether contacts with common concomitant pathogens are associated with the development of severe bTB lesions in 165 wild boar from mid-western Spain. The presence of bTB lesions affecting only one anatomic location (cervical lymph nodes), or more severe patterns affecting more than one location (mainly cervical lymph nodes and lungs), was assessed in infected animals. In addition, the existence of contacts with other pathogens such as porcine circovirus type 2 (PCV2), Aujeszky's disease virus (ADV), swine influenza virus, porcine reproductive and respiratory syndrome virus, Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae, Haemophilus parasuis and Metastrongylus spp, was evaluated by means of serological, microbiological and parasitological techniques. The existence of contacts with a structured community of pathogens in wild boar infected by M. bovis was statistically investigated by null models. Association between this community of pathogens and bTB severity was examined using a Partial Least Squares regression approach. Results showed that adult wild boar infected by M. bovis had contacted with some specific, non-random pathogen combinations. Contact with PCV2, ADV and infection by Metastrongylus spp, was positively correlated to tuberculosis severity. Therefore, measures against these concomitant pathogens such as vaccination or deworming, might be useful in tuberculosis control programmes in the wild boar. However, given the unexpected consequences of altering any community of organisms, further research should evaluate the impact of such measures under

  8. Severity of bovine tuberculosis is associated with co-infection with common pathogens in wild boar.

    Directory of Open Access Journals (Sweden)

    David Risco

    Full Text Available Co-infections with parasites or viruses drive tuberculosis dynamics in humans, but little is known about their effects in other non-human hosts. This work aims to investigate the relationship between Mycobacterium bovis infection and other pathogens in wild boar (Sus scrofa, a recognized reservoir of bovine tuberculosis (bTB in Mediterranean ecosystems. For this purpose, it has been assessed whether contacts with common concomitant pathogens are associated with the development of severe bTB lesions in 165 wild boar from mid-western Spain. The presence of bTB lesions affecting only one anatomic location (cervical lymph nodes, or more severe patterns affecting more than one location (mainly cervical lymph nodes and lungs, was assessed in infected animals. In addition, the existence of contacts with other pathogens such as porcine circovirus type 2 (PCV2, Aujeszky's disease virus (ADV, swine influenza virus, porcine reproductive and respiratory syndrome virus, Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae, Haemophilus parasuis and Metastrongylus spp, was evaluated by means of serological, microbiological and parasitological techniques. The existence of contacts with a structured community of pathogens in wild boar infected by M. bovis was statistically investigated by null models. Association between this community of pathogens and bTB severity was examined using a Partial Least Squares regression approach. Results showed that adult wild boar infected by M. bovis had contacted with some specific, non-random pathogen combinations. Contact with PCV2, ADV and infection by Metastrongylus spp, was positively correlated to tuberculosis severity. Therefore, measures against these concomitant pathogens such as vaccination or deworming, might be useful in tuberculosis control programmes in the wild boar. However, given the unexpected consequences of altering any community of organisms, further research should evaluate the impact of such measures

  9. Improving statistical inference on pathogen densities estimated by quantitative molecular methods: malaria gametocytaemia as a case study.

    Science.gov (United States)

    Walker, Martin; Basáñez, María-Gloria; Ouédraogo, André Lin; Hermsen, Cornelus; Bousema, Teun; Churcher, Thomas S

    2015-01-16

    Quantitative molecular methods (QMMs) such as quantitative real-time polymerase chain reaction (q-PCR), reverse-transcriptase PCR (qRT-PCR) and quantitative nucleic acid sequence-based amplification (QT-NASBA) are increasingly used to estimate pathogen density in a variety of clinical and epidemiological contexts. These methods are often classified as semi-quantitative, yet estimates of reliability or sensitivity are seldom reported. Here, a statistical framework is developed for assessing the reliability (uncertainty) of pathogen densities estimated using QMMs and the associated diagnostic sensitivity. The method is illustrated with quantification of Plasmodium falciparum gametocytaemia by QT-NASBA. The reliability of pathogen (e.g. gametocyte) densities, and the accompanying diagnostic sensitivity, estimated by two contrasting statistical calibration techniques, are compared; a traditional method and a mixed model Bayesian approach. The latter accounts for statistical dependence of QMM assays run under identical laboratory protocols and permits structural modelling of experimental measurements, allowing precision to vary with pathogen density. Traditional calibration cannot account for inter-assay variability arising from imperfect QMMs and generates estimates of pathogen density that have poor reliability, are variable among assays and inaccurately reflect diagnostic sensitivity. The Bayesian mixed model approach assimilates information from replica QMM assays, improving reliability and inter-assay homogeneity, providing an accurate appraisal of quantitative and diagnostic performance. Bayesian mixed model statistical calibration supersedes traditional techniques in the context of QMM-derived estimates of pathogen density, offering the potential to improve substantially the depth and quality of clinical and epidemiological inference for a wide variety of pathogens.

  10. Morphological and molecular characterization of Fusarium spp. associated with olive trees dieback in Tunisia.

    Science.gov (United States)

    Trabelsi, Rahma; Sellami, Hanen; Gharbi, Yâakoub; Krid, Samira; Cheffi, Manel; Kammoun, Sonia; Dammak, Mariem; Mseddi, Aymen; Gdoura, Radhouane; Triki, Mohamed Ali

    2017-05-01

    Dieback and wilting symptoms caused by complex soilborne fungi are nowadays the most serious threatening disease affecting olive trees (Olea europaea) in Tunisia and presumably in many Mediterranean basin countries. Fusarium is one of the important phytopathogenic genera associated with dieback symptoms of olive trees. The objective of the present study was to confirm the pathogenicity of Fusarium spp. isolated from several olive-growing areas in Tunisia. According to the pathogenic test done on young olive trees (cv. Chemlali), 23 out of 104 isolates of Fusarium spp. were found to be pathogenic and the others were weakly or not pathogenic. The pathogenic Fusarium spp. isolates were characterized using molecular methods based on ITS PCR. Isolation results revealed the predominance of Fusarium solani (56.5%) and F. oxysporum species (21.7%) compared to F. chalmydosporum (8.7%), F. brachygibbosum (8.7%) and F. acuminatum (4.34%). Based on pathogenicity test, disease severity was highly variable among the 23 pathogenic isolates tested (P Fusarium spp. might be a major agent causing dieback disease of olive trees in Tunisia.

  11. The HLA-B landscape of Africa: Signatures of pathogen-driven selection and molecular identification of candidate alleles to malaria protection

    Czech Academy of Sciences Publication Activity Database

    Sanchez-Mazas, A.; Černý, V.; Di, D.; Buhler, S.; Podgorná, Eliška; Chevallier, E.; Brunet, L.; Weber, S.; Kervaire, B.; Testi, M.; Andreani, M.; Tiercy, J.-M.; Villard, J.; Nunes, J. M.

    2017-01-01

    Roč. 26, č. 22 (2017), s. 6238-6252 ISSN 0962-1083 R&D Projects: GA ČR GA13-37998S Institutional support: RVO:67985912 Keywords : African populations * geographic patterns * HLA polymorphism and disease associations * human population genetics * malaria protection * pathogen-driven selection Subject RIV: AC - Archeology, Anthropology, Ethnology OBOR OECD: Archaeology Impact factor: 6.086, year: 2016

  12. Pattern Recognition via the Toll-Like Receptor System in the Human Female Genital Tract

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    Kaei Nasu

    2010-01-01

    Full Text Available The mucosal surface of the female genital tract is a complex biosystem, which provides a barrier against the outside world and participates in both innate and acquired immune defense systems. This mucosal compartment has adapted to a dynamic, non-sterile environment challenged by a variety of antigenic/inflammatory stimuli associated with sexual intercourse and endogenous vaginal microbiota. Rapid innate immune defenses against microbial infection usually involve the recognition of invading pathogens by specific pattern-recognition receptors recently attributed to the family of Toll-like receptors (TLRs. TLRs recognize conserved pathogen-associated molecular patterns (PAMPs synthesized by microorganisms including bacteria, fungi, parasites, and viruses as well as endogenous ligands associated with cell damage. Members of the TLR family, which includes 10 human TLRs identified to date, recognize distinct PAMPs produced by various bacterial, fungal, and viral pathogens. The available literature regarding the innate immune system of the female genital tract during human reproductive processes was reviewed in order to identify studies specifically related to the expression and function of TLRs under normal as well as pathological conditions. Increased understanding of these molecules may provide insight into site-specific immunoregulatory mechanisms in the female reproductive tract.

  13. Plant Responses to Pathogen Attack: Small RNAs in Focus.

    Science.gov (United States)

    Islam, Waqar; Noman, Ali; Qasim, Muhammad; Wang, Liande

    2018-02-08

    Small RNAs (sRNA) are a significant group of gene expression regulators for multiple biological processes in eukaryotes. In plants, many sRNA silencing pathways produce extensive array of sRNAs with specialized roles. The evidence on record advocates for the functions of sRNAs during plant microbe interactions. Host sRNAs are reckoned as mandatory elements of plant defense. sRNAs involved in plant defense processes via different pathways include both short interfering RNA (siRNA) and microRNA (miRNA) that actively regulate immunity in response to pathogenic attack via tackling pathogen-associated molecular patterns (PAMPs) and other effectors. In response to pathogen attack, plants protect themselves with the help of sRNA-dependent immune systems. That sRNA-mediated plant defense responses play a role during infections is an established fact. However, the regulations of several sRNAs still need extensive research. In this review, we discussed the topical advancements and findings relevant to pathogen attack and plant defense mediated by sRNAs. We attempted to point out diverse sRNAs as key defenders in plant systems. It is hoped that sRNAs would be exploited as a mainstream player to achieve food security by tackling different plant diseases.

  14. Molecular mechanisms associated with nosocomial carbapenem-resistant Acinetobacter baumannii in Mexico.

    Science.gov (United States)

    Alcántar-Curiel, María Dolores; García-Torres, Luis Francisco; González-Chávez, María Inés; Morfín-Otero, Rayo; Gayosso-Vázquez, Catalina; Jarillo-Quijada, Ma Dolores; Fernández-Vázquez, José Luis; Giono-Cerezo, Silvia; Rodríguez-Noriega, Eduardo; Santos-Preciado, José Ignacio

    2014-10-01

    Acinetobacter baumannii is an emerging pathogen worldwide that is most commonly associated with nosocomial infections and multi-drug resistance. In the present study we determined the mechanisms of carbapenem resistance and clonal diversity of A. baumannii nosocomial isolates in Hospital Civil de Guadalajara, Mexico. A total of 303 clinical isolates of A. baumannii identified during a period expanding from 2004-2011 were analyzed for carbapenem resistance using several microbiological and molecular methods. Clonal relatedness of these isolates was determined using pulsed-field gel electrophoresis. Of the 303 isolates, 84% were resistant to meropenem, 71.3% to imipenem and 78.3% the resistant isolates were positive for metallo-β-lactamases as determined by the phenotypic assay. In addition, 49.6% of carbapenem-intermediate or -resistant isolates carried the blaOXA-72 gene and 1.2% carried the blaVIM-1 gene. Efflux pump phenotype was responsible for reduced susceptibility to meropenem in 14.5% and to imipenem in 31.6% of the resistant isolates, respectively in the presence of the efflux pump inhibitor, carbonyl cyanide 3-chlorophenylhydrazone. Strains representing different carbapenem-resistant patterns exhibited reduced expression of 22, 29, 33, and 43 kDa OMPs. Among the bacterial collection studied, 48 different clones were identified, two of which were predominant and persistently transmitted. Carbapenemase production in combination with efflux pump expression, reduction in OMPs expression and the cross-transmission of clones appear to be major contributors to the high frequency of carbapenem-resistance observed in A. baumannii. To our knowledge, this is the first study to define the molecular mechanisms associated with carbapenem-resistance in A. baumannii in Mexico. Copyright © 2014 IMSS. Published by Elsevier Inc. All rights reserved.

  15. Emerging trends in molecular interactions between plants and the broad host range fungal pathogens Botrytis cinerea and Sclerotinia sclerotiorum

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    Malick eMbengue

    2016-03-01

    Full Text Available Fungal plant pathogens are major threats to food security worldwide. Sclerotinia sclerotiorum and Botrytis cinerea are closely related Ascomycete plant pathogens causing mold diseases on hundreds of plant species. There is no genetic source of complete plant resistance to these broad host range pathogens known to date. Instead, natural plant populations show a continuum of resistance levels controlled by multiple genes, a phenotype designated as quantitative disease resistance. Little is known about the molecular mechanisms controlling the interaction between plants and S. sclerotiorum and B. cinerea but significant advances were made on this topic in the last years. This minireview highlights a selection of nine themes that emerged in recent research reports on the molecular bases of plant-S. sclerotiorum and plant-B. cinerea interactions. On the fungal side, this includes progress on understanding the role of oxalic acid, on the study of fungal small secreted proteins. Next, we discuss the exchanges of small RNA between organisms and the control of cell death in plant and fungi during pathogenic interactions. Finally on the plant side, we highlight defense priming by mechanical signals, the characterization of plant Receptor-like proteins and the hormone abscisic acid in the response to B. cinerea and S. sclerotiorum , the role of plant general transcription machinery and plant small bioactive peptides. These represent nine trends we selected as remarkable in our understanding of fungal molecules causing disease and plant mechanisms associated with disease resistance to two devastating broad host range fungi.

  16. Isolation and characterization of pathogenic leptospires associated with cattle

    Science.gov (United States)

    Pathogenic leptospires colonize the renal tubules of reservoir hosts of infection, including cattle, and are excreted via urine. In order to identify circulating serovars of pathogenic leptospires in beef cattle, and their associated rates of urinary excretion, a cross sectional study was performed....

  17. Apoptosis, Toll-like, RIG-I-like and NOD-like Receptors Are Pathways Jointly Induced by Diverse Respiratory Bacterial and Viral Pathogens

    Science.gov (United States)

    Martínez, Isidoro; Oliveros, Juan C.; Cuesta, Isabel; de la Barrera, Jorge; Ausina, Vicente; Casals, Cristina; de Lorenzo, Alba; García, Ernesto; García-Fojeda, Belén; Garmendia, Junkal; González-Nicolau, Mar; Lacoma, Alicia; Menéndez, Margarita; Moranta, David; Nieto, Amelia; Ortín, Juan; Pérez-González, Alicia; Prat, Cristina; Ramos-Sevillano, Elisa; Regueiro, Verónica; Rodriguez-Frandsen, Ariel; Solís, Dolores; Yuste, José; Bengoechea, José A.; Melero, José A.

    2017-01-01

    Lower respiratory tract infections are among the top five leading causes of human death. Fighting these infections is therefore a world health priority. Searching for induced alterations in host gene expression shared by several relevant respiratory pathogens represents an alternative to identify new targets for wide-range host-oriented therapeutics. With this aim, alveolar macrophages were independently infected with three unrelated bacterial (Streptococcus pneumoniae, Klebsiella pneumoniae, and Staphylococcus aureus) and two dissimilar viral (respiratory syncytial virus and influenza A virus) respiratory pathogens, all of them highly relevant for human health. Cells were also activated with bacterial lipopolysaccharide (LPS) as a prototypical pathogen-associated molecular pattern. Patterns of differentially expressed cellular genes shared by the indicated pathogens were searched by microarray analysis. Most of the commonly up-regulated host genes were related to the innate immune response and/or apoptosis, with Toll-like, RIG-I-like and NOD-like receptors among the top 10 signaling pathways with over-expressed genes. These results identify new potential broad-spectrum targets to fight the important human infections caused by the bacteria and viruses studied here. PMID:28298903

  18. Pathogens' toolbox to manipulate human complement.

    Science.gov (United States)

    Fernández, Francisco J; Gómez, Sara; Vega, M Cristina

    2017-12-14

    The surveillance and pathogen fighting functions of the complement system have evolved to protect mammals from life-threatening infections. In turn, pathogens have developed complex molecular mechanisms to subvert, divert and evade the effector functions of the complement. The study of complement immunoevasion by pathogens sheds light on their infection drivers, knowledge that is essential to implement therapies. At the same time, complement evasion also acts as a discovery ground that reveals important aspects of how complement works under physiological conditions. In recent years, complex interrelationships between infection insults and the onset of autoimmune and complement dysregulation diseases have led to propose that encounters with pathogens can act as triggering factors for disease. The correct management of these diseases involves the recognition of their triggering factors and the development and administration of complement-associated molecular therapies. Even more recently, unsuspected proteins from pathogens have been shown to possess moonlighting functions as virulence factors, raising the possibility that behind the first line of virulence factors there be many more pathogen proteins playing secondary, helping and supporting roles for the pathogen to successfully establish infections. In an era where antibiotics have a progressively reduced effect on the management and control of infectious diseases worldwide, knowledge on the mechanisms of pathogenic invasion and evasion look more necessary and pressing than ever. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Malagasy bats shelter a considerable genetic diversity of pathogenic Leptospira suggesting notable host-specificity patterns.

    Science.gov (United States)

    Gomard, Yann; Dietrich, Muriel; Wieseke, Nicolas; Ramasindrazana, Beza; Lagadec, Erwan; Goodman, Steven M; Dellagi, Koussay; Tortosa, Pablo

    2016-04-01

    Pathogenic Leptospira are the causative agents of leptospirosis, a disease of global concern with major impact in tropical regions. Despite the importance of this zoonosis for human health, the evolutionary and ecological drivers shaping bacterial communities in host reservoirs remain poorly investigated. Here, we describe Leptospira communities hosted by Malagasy bats, composed of mostly endemic species, in order to characterize host-pathogen associations and investigate their evolutionary histories. We screened 947 individual bats (representing 31 species, 18 genera and seven families) for Leptospira infection and subsequently genotyped positive samples using three different bacterial loci. Molecular identification showed that these Leptospira are notably diverse and include several distinct lineages mostly belonging to Leptospira borgpetersenii and L. kirschneri. The exploration of the most probable host-pathogen evolutionary scenarios suggests that bacterial genetic diversity results from a combination of events related to the ecology and the evolutionary history of their hosts. Importantly, based on the data set presented herein, the notable host-specificity we have uncovered, together with a lack of geographical structuration of bacterial genetic diversity, indicates that the Leptospira community at a given site depends on the co-occurring bat species assemblage. The implications of such tight host-specificity on the epidemiology of leptospirosis are discussed. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Arthropods vector grapevine trunk disease pathogens.

    Science.gov (United States)

    Moyo, P; Allsopp, E; Roets, F; Mostert, L; Halleen, F

    2014-10-01

    Arthropod-mediated dispersal of pathogens is known in many cropping systems but has never been demonstrated for grapevine trunk disease pathogens. Arthropods from vineyards were screened for the presence of pathogens associated with Petri disease and esca using cultural and molecular techniques. The ability of the most abundant pathogen-carrying species to inoculate healthy grapevine vascular tissues was also determined. Millipedes and ants were allowed to associate with a DsRed- Express-transformed Phaeomoniella chlamydospora, after which they were exposed to freshly pruned healthy grapevines under controlled conditions and wounds were monitored for subsequent infection. In addition, the possibility of millipede excreta, commonly found on pruning wounds in the field, to act as inoculum source was determined. A diverse arthropod fauna was associated with declining grapevines and many of these carried trunk disease pathogens. However, spiders, the ant Crematogaster peringueyi, and the millipede Ommattoiulus moreleti were the most abundant pathogen carriers. The ant and millipede species fed on pruning wound sap and effectively transmitted trunk disease pathogens. Millipede excreta contained viable spores of Phaeomoniella chlamydospora and may serve as an inoculum source. Numerous arthropods, including beneficial predators, are potential vectors of grapevine trunk disease pathogens. Our results highlight the need for an integrated approach, including targeted management of ants and millipedes at the time of pruning, to limit the spread of grapevine trunk diseases.

  1. Lawrence Livermore National Laboratory Workshop Characterization of Pathogenicity, Virulence and Host-Pathogen Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, A

    2006-08-30

    The threats of bio-terrorism and newly emerging infectious diseases pose serious challenges to the national security infrastructure. Rapid detection and diagnosis of infectious disease in human populations, as well as characterizing pathogen biology, are critical for reducing the morbidity and mortality associated with such threats. One of the key challenges in managing an infectious disease outbreak, whether through natural causes or acts of overt terrorism, is detection early enough to initiate effective countermeasures. Much recent attention has been directed towards the utility of biomarkers or molecular signatures that result from the interaction of the pathogen with the host for improving our ability to diagnose and mitigate the impact of a developing infection during the time window when effective countermeasures can be instituted. Host responses may provide early signals in blood even from localized infections. Multiple innate and adaptive immune molecules, in combination with other biochemical markers, may provide disease-specific information and new targets for countermeasures. The presence of pathogen specific markers and an understanding of the molecular capabilities and adaptations of the pathogen when it interacts with its host may likewise assist in early detection and provide opportunities for targeting countermeasures. An important question that needs to be addressed is whether these molecular-based approaches will prove useful for early diagnosis, complement current methods of direct agent detection, and aid development and use of countermeasures. Lawrence Livermore National Laboratory (LLNL) will host a workshop to explore the utility of host- and pathogen-based molecular diagnostics, prioritize key research issues, and determine the critical steps needed to transition host-pathogen research to tools that can be applied towards a more effective national bio-defense strategy. The workshop will bring together leading researchers/scientists in the

  2. Exploration of Fungal Association From Hard Coral Against Pathogen MDR Staphylococcus haemolyticus

    Science.gov (United States)

    Cristianawati, O.; Radjasa, O. K.; Sabdono, A.; Trianto, A.; Sabdaningsih, A.; Sibero, M. T.; Nuryadi, H.

    2017-02-01

    Staphylococcus haemolyticus are opportunistic bacteria and as the second leading cause of nosocomial infections. It is a disease causing septicemia, peritonitis, otitis, and urinary tract infections and infections of the eye. It also a phenotype resistant to multiple antibiotics commercial. There is now an urgency to find an alternative antibiotics to combat this bacteria. It has been widely reported that many bioactive marine natural products from marine invertebrate have striking similarities to metabolites of their associated microorganisms including fungi. Hard coral associated microorganisms are among of the most interesting and promising marine natural product sources, which produce with various biological activities. The proposed work focused on the discovery of bioactive compounds and also estimated the phylogenetic diversity from fungal association of hard coral against pathogen MDR Staphylococcus haemolyticus. A total of 32 fungal association, FHP 7 which were isolated from Favia sp. capable of inhibiting the growth MDR. Molecular identification based on 18S rRNA gene sequences revealed that the active fungal association belonged 100% to the members from one of the genera Trichoderma longibrachiatum. Accession Number LC185084.1.

  3. Molecular characterization and pathogenicity of Erwinia spp. associated with pineapple [Ananas comosus (L. Merr.] and papaya (Carica papaya L.

    Directory of Open Access Journals (Sweden)

    Ramachandran Kogeethavani

    2015-12-01

    Full Text Available The Erwinia species are well-known pathogens of economic importance in Malaysia causing serious damage to high-value fruit crops that include pineapple [Ananas comosus (L. Merr.] and papaya (Carica papaya L..The 16S rRNA sequence using eubacteria fD1 and rP2 primers, identified two bacteria species; Dickeya zeae from pineapple heart rot, and Erwinia mallotivora from papaya dieback. Phylogenetic analysis based on the neighbor-joining method indicated that all the bacterial isolates clustered in their own taxa and formed monophyletic clades. From the pathogenicity test, all isolates of D. zeae and E. mallotivora showed pathogenic reactions on their respective host plants. Genetic variability of these isolates was assessed using repetitive sequence-based PCR (rep-PCR fingerprinting. The results indicated interspecies, and intraspecies variation in both species’ isolates. There were more polymorphic bands shown by rep-PCR fingerprints than enterobacterial repetitive intergenic consensus (ERIC and BOX- PCRs, however both species’ isolates produced distinguishable banding patterns. Unweighted pair-group method with arithmetic averages (UPGMA cluster analysis indicated that all Dickeya and Erwinia isolates from the same species were grouped in the same main cluster. Similarity among the isolates ranged from 77 to 99%. Sequencing of 16S rRNA using eubacteria fD1 and rP2 primers, and rep-PCR fingerprinting revealed diversity among Dickeya and Erwinia isolates. But this method appears to be reliable for discriminating isolates from pineapple heart rot and papaya dieback.

  4. The role of pathogen-associated molecular patterns and islet-derived danger-associated molecular patterns in longevity of microencapsulated pancreatic islets

    NARCIS (Netherlands)

    Paredes Juárez, Genaro Alberto

    2016-01-01

    Immunoisolation of cells by encapsulation in semipermeable membranes has been proposed as a cure for many endocrine diseases where a minute-to-minute regulation of metabolites is a requirement such as in anemia, dwarfism, kidney and liver failure, pituitary and central nervous system

  5. Dermal γδ T-Cells Can Be Activated by Mitochondrial Damage-Associated Molecular Patterns.

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    Martin G Schwacha

    Full Text Available Gamma delta T-cells have been shown to be important to the early immunoinflammatory response to injury, independent of infection. This unique T-cell population acts to regulate cell trafficking and the release of cytokines and growth factors. We propose this sterile inflammatory response is in part associated with damage associated molecular patterns (DAMPs generated by major injury, such as burn, and mediated via toll-like receptors (TLRs. It is unknown whether DAMPs can activate resident γδ T-cells that reside in skin.Gamma delta T-cells were isolated from the skin of male C57BL/6 mice by enzymatic digestion. Mitochondrial DAMPs (MTDs were generated from mitochondria isolated from mouse livers by sonication and centrifugation. Dermal γδ T-cells were incubated with MTDs (0-500 μg/ml for 24 hr and cells and supernatants were collected for analysis.MTDs activated dermal γδ T-cells, as evidenced by increased TLR2 and TLR4 expression following in vitro exposure. MTDs also induced the production of inflammatory cytokines (IL-1β, IL-6, and growth factors (PDGF and VEGF by γδ T-cells.These findings herein support the concept that MTDs released after tissue/cellular injury are capable of activating dermal γδ T-cells. We propose that the activation of this unique T-cell population is central in the initiation of sterile inflammation and also contributes to the subsequent healing processes.

  6. Molecular mapping of the cell wall polysaccharides of the human pathogen Streptococcus agalactiae

    Science.gov (United States)

    Beaussart, Audrey; Péchoux, Christine; Trieu-Cuot, Patrick; Hols, Pascal; Mistou, Michel-Yves; Dufrêne, Yves F.

    2014-11-01

    The surface of many bacterial pathogens is covered with polysaccharides that play important roles in mediating pathogen-host interactions. In Streptococcus agalactiae, the capsular polysaccharide (CPS) is recognized as a major virulence factor while the group B carbohydrate (GBC) is crucial for peptidoglycan biosynthesis and cell division. Despite the important roles of CPS and GBC, there is little information available on the molecular organization of these glycopolymers on the cell surface. Here, we use atomic force microscopy (AFM) and transmission electron microscopy (TEM) to analyze the nanoscale distribution of CPS and GBC in wild-type (WT) and mutant strains of S. agalactiae. TEM analyses reveal that in WT bacteria, peptidoglycan is covered with a very thin (few nm) layer of GBC (the ``pellicle'') overlaid by a 15-45 nm thick layer of CPS (the ``capsule''). AFM-based single-molecule mapping with specific antibody probes shows that CPS is exposed on WT cells, while it is hardly detected on mutant cells impaired in CPS production (ΔcpsE mutant). By contrast, both TEM and AFM show that CPS is over-expressed in mutant cells altered in GBC expression (ΔgbcO mutant), indicating that the production of the two surface glycopolymers is coordinated in WT cells. In addition, AFM topographic imaging and molecular mapping with specific lectin probes demonstrate that removal of CPS (ΔcpsE), but not of GBC (ΔgbcO), leads to the exposure of peptidoglycan, organized into 25 nm wide bands running parallel to the septum. These results indicate that CPS forms a homogeneous barrier protecting the underlying peptidoglycan from environmental exposure, while the presence of GBC does not prevent peptidoglycan detection. This work shows that single-molecule AFM, combined with high-resolution TEM, represents a powerful platform for analysing the molecular arrangement of the cell wall polymers of bacterial pathogens.

  7. Identification of Outpatient Urinary Pathogens and Antibiotic Susceptibility Pattern in Ahwaz, Iran 2002-2003

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    mohammad saeed Saraj

    2005-02-01

    Full Text Available Background: Urinary tract infection (UTI is a common syndrom in community, especially in females. The object of this study is to determine the prevalence of most common Bacteria causing UTI and Antibiogram pattern respectively in Ahwas population. Materials & methods: In this retrospective descriptive study we gathered all urine culture results from lab centers. Results: From 48850 cases, 34360 (70.34% and 14490 (29.66% were females and males, respectively. The most frequent pathogens were E.coli (46.29%, S.saprophyticus (25.8% and Klebsiella (16.93%. Enterobacter, Proteus citrobacter, Pseudomonas and S.epidermidis were consisted the remainder of causes. The most Susceptible Antibiotics for the most prevalent pathogens, were: Nalidixic Acid, Vancomycine, and Nitrofurantoin, respectively. Conclusion: This pattern is similar to that mentioned in textbooks and published reports from other cities in Iran.

  8. Molecular detection of blood pathogens and their impacts on levels of packed cell volume in stray dogs from Thailand

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    Supawadee Piratae

    2017-04-01

    Full Text Available Objective: To evaluate the prevalence of blood parasite infection in stray dogs by PCR technique and the association between levels of packed cell volume (PCV and blood parasitic infection in stray dogs. Methods: A total of 65 blood samples were collected from stray dogs in animal quarantine station from Mahasarakham, Thailand to evaluate the levels of PCV before molecular screening for tick-borne pathogens infection. Results: Stray dogs were positive with one or more pathogens in 44 (67.69% out of 65 blood samples. Ehrlichia canis [43.1%, 95% confidence interval (CI: 38.1–48.1] was the most common blood pathogen found infecting in stray dogs in Mahasarakham Province, followed by Anaplasma platys (29.2%, 95% CI: 24.2–34.2, Hepatozoon canis (12.3%, 95% CI: 7.3–17.3 and Babesia canis vogeli (6.2%, 95% CI: 1.2–11.2, respectively. Moreover, co-infections with two pathogens were identified in 11 (16.9% of dogs examined and two (2.9% dogs were coinfections with three pathogens. Statistically significant relationship between the PCV levels and Ehrlichia canis infection was found (P < 0.05. Conclusions: This study indicated that blood pathogens are spreading in stray dogs and they are potentially high risk of agent transmission to human via exposure with tick vectors. It was also the first report of Anaplasma platys infection in dogs in north-eastern part of Thailand.

  9. The battle in the apoplast: further insights into the roles of proteases and their inhibitors in plant-pathogen interactions

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    Mansoor eKarimi Jashni

    2015-08-01

    Full Text Available Upon host penetration, fungal pathogens secrete a plethora of effectors to promote disease, including proteases that degrade plant antimicrobial proteins, and protease inhibitors (PIs that inhibit plant proteases with antimicrobial activity. Conversely, plants secrete proteases and PIs to protect themselves against pathogens or to mediate recognition of pathogen proteases and PIs, which leads to induction of defense responses. Many examples of proteases and PIs mediating effector-triggered immunity in host plants have been reported in the literature, but little is known about their role in compromising basal defense responses induced by microbe-associated molecular patterns. Recently, several reports appeared in literature on secreted fungal proteases that modify or degrade pathogenesis-related proteins, including plant chitinases or PIs that compromise their activities. This prompted us to review the recent advances on proteases and PIs involved in fungal virulence and plant defense. Proteases and PIs from plants and their fungal pathogens play an important role in the arms race between plants and pathogens, which has resulted in co-evolutionary diversification and adaptation shaping pathogen lifestyles.

  10. Pathogen Inactivating Properties and Increased Sensitivity in Molecular Diagnostics by PAXgene, a Novel Non-Crosslinking Tissue Fixative.

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    Martina Loibner

    Full Text Available Requirements on tissue fixatives are getting more demanding as molecular analysis becomes increasingly relevant for routine diagnostics. Buffered formaldehyde in pathology laboratories for tissue fixation is known to cause chemical modifications of biomolecules which affect molecular testing. A novel non-crosslinking tissue preservation technology, PAXgene Tissue (PAXgene, was developed to preserve the integrity of nucleic acids in a comparable way to cryopreservation and also to preserve morphological features comparable to those of formalin fixed samples.Because of the excellent preservation of biomolecules by PAXgene we investigated its pathogen inactivation ability and biosafety in comparison to formalin by in-vitro testing of bacteria, human relevant fungi and human cytomegalovirus (CMV. Guidelines for testing disinfectants served as reference for inactivation assays. Furthermore, we tested the properties of PAXgene for detection of pathogens by PCR based assays.All microorganisms tested were similarly inactivated by PAXgene and formalin except Clostridium sporogenes, which remained viable in seven out of ten assays after PAXgene treatment and in three out of ten assays after formalin fixation. The findings suggest that similar biosafety measures can be applied for PAXgene and formalin fixed samples. Detection of pathogens in PCR-based diagnostics using two CMV assays resulted in a reduction of four to ten quantification cycles of PAXgene treated samples which is a remarkable increase of sensitivity.PAXgene fixation might be superior to formalin fixation when molecular diagnostics and highly sensitive detection of pathogens is required in parallel to morphology assessment.

  11. Pathogen Inactivating Properties and Increased Sensitivity in Molecular Diagnostics by PAXgene, a Novel Non-Crosslinking Tissue Fixative.

    Science.gov (United States)

    Loibner, Martina; Buzina, Walter; Viertler, Christian; Groelz, Daniel; Hausleitner, Anja; Siaulyte, Gintare; Kufferath, Iris; Kölli, Bettina; Zatloukal, Kurt

    2016-01-01

    Requirements on tissue fixatives are getting more demanding as molecular analysis becomes increasingly relevant for routine diagnostics. Buffered formaldehyde in pathology laboratories for tissue fixation is known to cause chemical modifications of biomolecules which affect molecular testing. A novel non-crosslinking tissue preservation technology, PAXgene Tissue (PAXgene), was developed to preserve the integrity of nucleic acids in a comparable way to cryopreservation and also to preserve morphological features comparable to those of formalin fixed samples. Because of the excellent preservation of biomolecules by PAXgene we investigated its pathogen inactivation ability and biosafety in comparison to formalin by in-vitro testing of bacteria, human relevant fungi and human cytomegalovirus (CMV). Guidelines for testing disinfectants served as reference for inactivation assays. Furthermore, we tested the properties of PAXgene for detection of pathogens by PCR based assays. All microorganisms tested were similarly inactivated by PAXgene and formalin except Clostridium sporogenes, which remained viable in seven out of ten assays after PAXgene treatment and in three out of ten assays after formalin fixation. The findings suggest that similar biosafety measures can be applied for PAXgene and formalin fixed samples. Detection of pathogens in PCR-based diagnostics using two CMV assays resulted in a reduction of four to ten quantification cycles of PAXgene treated samples which is a remarkable increase of sensitivity. PAXgene fixation might be superior to formalin fixation when molecular diagnostics and highly sensitive detection of pathogens is required in parallel to morphology assessment.

  12. Linking healthcare associated norovirus outbreaks: a molecular epidemiologic method for investigating transmission

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    Andrews Nick

    2006-07-01

    Full Text Available Abstract Background Noroviruses are highly infectious pathogens that cause gastroenteritis in the community and in semi-closed institutions such as hospitals. During outbreaks, multiple units within a hospital are often affected, and a major question for control programs is: are the affected units part of the same outbreak or are they unrelated transmission events? In practice, investigators often assume a transmission link based on epidemiological observations, rather than a systematic approach to tracing transmission. Here, we present a combined molecular and statistical method for assessing: 1 whether observed clusters provide evidence of local transmission and 2 the probability that anecdotally|linked outbreaks truly shared a transmission event. Methods 76 healthcare associated outbreaks were observed in an active and prospective surveillance scheme of 15 hospitals in the county of Avon, England from April 2002 to March 2003. Viral RNA from 64 out of 76 specimens from distinct outbreaks was amplified by reverse transcription-PCR and was sequenced in the polymerase (ORF 1 and capsid (ORF 2 regions. The genetic diversity, at the nucleotide level, was analysed in relation to the epidemiological patterns. Results Two out of four genetic and epidemiological clusters of outbreaks were unlikely to have occurred by chance alone, thus suggesting local transmission. There was anecdotal epidemiological evidence of a transmission link among 5 outbreaks pairs. By combining this epidemiological observation with viral sequence data, the evidence of a link remained convincing in 3 of these pairs. These results are sensitive to prior beliefs of the strength of epidemiological evidence especially when the outbreak strains are common in the background population. Conclusion The evidence suggests that transmission between hospitals units does occur. Using the proposed criteria, certain hypothesized transmission links between outbreaks were supported while

  13. Label-free molecular imaging of bacterial communities of the opportunistic pathogen Pseudomonas aeruginosa

    Science.gov (United States)

    Baig, Nameera; Polisetti, Sneha; Morales-Soto, Nydia; Dunham, Sage J. B.; Sweedler, Jonathan V.; Shrout, Joshua D.; Bohn, Paul W.

    2016-09-01

    Biofilms, such as those formed by the opportunistic human pathogen Pseudomonas aeruginosa are complex, matrix enclosed, and surface-associated communities of cells. Bacteria that are part of a biofilm community are much more resistant to antibiotics and the host immune response than their free-floating counterparts. P. aeruginosa biofilms are associated with persistent and chronic infections in diseases such as cystic fibrosis and HIV-AIDS. P. aeruginosa synthesizes and secretes signaling molecules such as the Pseudomonas quinolone signal (PQS) which are implicated in quorum sensing (QS), where bacteria regulate gene expression based on population density. Processes such as biofilms formation and virulence are regulated by QS. This manuscript describes the powerful molecular imaging capabilities of confocal Raman microscopy (CRM) and surface enhanced Raman spectroscopy (SERS) in conjunction with multivariate statistical tools such as principal component analysis (PCA) for studying the spatiotemporal distribution of signaling molecules, secondary metabolites and virulence factors in biofilm communities of P. aeruginosa. Our observations reveal that the laboratory strain PAO1C synthesizes and secretes 2-alkyl-4-hydroxyquinoline N-oxides and 2-alkyl-4-hydroxyquinolones in high abundance, while the isogenic acyl homoserine lactone QS-deficient mutant (ΔlasIΔrhlI) strain produces predominantly 2-alkyl-quinolones during biofilm formation. This study underscores the use of CRM, along with traditional biological tools such as genetics, for studying the behavior of microbial communities at the molecular level.

  14. epiPATH: an information system for the storage and management of molecular epidemiology data from infectious pathogens

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    González-Candelas Fernando

    2007-04-01

    Full Text Available Abstract Background Most research scientists working in the fields of molecular epidemiology, population and evolutionary genetics are confronted with the management of large volumes of data. Moreover, the data used in studies of infectious diseases are complex and usually derive from different institutions such as hospitals or laboratories. Since no public database scheme incorporating clinical and epidemiological information about patients and molecular information about pathogens is currently available, we have developed an information system, composed by a main database and a web-based interface, which integrates both types of data and satisfies requirements of good organization, simple accessibility, data security and multi-user support. Results From the moment a patient arrives to a hospital or health centre until the processing and analysis of molecular sequences obtained from infectious pathogens in the laboratory, lots of information is collected from different sources. We have divided the most relevant data into 12 conceptual modules around which we have organized the database schema. Our schema is very complete and it covers many aspects of sample sources, samples, laboratory processes, molecular sequences, phylogenetics results, clinical tests and results, clinical information, treatments, pathogens, transmissions, outbreaks and bibliographic information. Communication between end-users and the selected Relational Database Management System (RDMS is carried out by default through a command-line window or through a user-friendly, web-based interface which provides access and management tools for the data. Conclusion epiPATH is an information system for managing clinical and molecular information from infectious diseases. It facilitates daily work related to infectious pathogens and sequences obtained from them. This software is intended for local installation in order to safeguard private data and provides advanced SQL-users the

  15. The role of lipopolysaccharide and peptidoglycan, two glycosylated bacterial microbe-associated molecular patterns (MAMPs), in plant innate immunity

    DEFF Research Database (Denmark)

    Erbs, Gitte; Newman, Mari-Anne

    2012-01-01

    innate immune system through the action of pattern recognition receptors (PRRs). A greater insight into the mechanisms of MAMP recognition and the description of PRRs for different microbial glycoconjugates will have considerable impact on the improvement of plant health and disease resistance. Here...... to as ‘innate immunity’. Innate immunity is the first line of defence against invading microorganisms in vertebrates and the only line of defence in invertebrates and plants. Bacterial glycoconjugates, such as lipopolysaccharides (LPSs) from the outer membrane of Gram-negative bacteria and peptidoglycan (PGN......) from the cell walls of both Gram-positive and Gram-negative bacteria, have been found to act as elicitors of plant innate immunity. These conserved, indispensable, microbe-specific molecules are also referred to as ‘microbe-associated molecular patterns’ (MAMPs). MAMPs are recognized by the plant...

  16. Duplications and losses in gene families of rust pathogens highlight putative effectors.

    Science.gov (United States)

    Pendleton, Amanda L; Smith, Katherine E; Feau, Nicolas; Martin, Francis M; Grigoriev, Igor V; Hamelin, Richard; Nelson, C Dana; Burleigh, J Gordon; Davis, John M

    2014-01-01

    Rust fungi are a group of fungal pathogens that cause some of the world's most destructive diseases of trees and crops. A shared characteristic among rust fungi is obligate biotrophy, the inability to complete a lifecycle without a host. This dependence on a host species likely affects patterns of gene expansion, contraction, and innovation within rust pathogen genomes. The establishment of disease by biotrophic pathogens is reliant upon effector proteins that are encoded in the fungal genome and secreted from the pathogen into the host's cell apoplast or within the cells. This study uses a comparative genomic approach to elucidate putative effectors and determine their evolutionary histories. We used OrthoMCL to identify nearly 20,000 gene families in proteomes of 16 diverse fungal species, which include 15 basidiomycetes and one ascomycete. We inferred patterns of duplication and loss for each gene family and identified families with distinctive patterns of expansion/contraction associated with the evolution of rust fungal genomes. To recognize potential contributors for the unique features of rust pathogens, we identified families harboring secreted proteins that: (i) arose or expanded in rust pathogens relative to other fungi, or (ii) contracted or were lost in rust fungal genomes. While the origin of rust fungi appears to be associated with considerable gene loss, there are many gene duplications associated with each sampled rust fungal genome. We also highlight two putative effector gene families that have expanded in Cqf that we hypothesize have roles in pathogenicity.

  17. An Australian population study of factors associated with MRI patterns in cerebral palsy.

    Science.gov (United States)

    Reid, Susan M; Dagia, Charuta D; Ditchfield, Michael R; Carlin, John B; Meehan, Elaine M; Reddihough, Dinah S

    2014-02-01

    The aim of this study was to describe the distribution of magnetic resonance imaging (MRI) patterns in a large population sample of children with cerebral palsy (CP) and to examine associations between MRI patterns, and antenatal and perinatal variables. Data were retrieved from the Victorian CP Register for 884 children (527 males, 357 females) born between 1999 and 2006. Postneonatal MRI was classified for 594 children. For 563 children (329 males, 234 females) for whom classification was to a single MRI pattern, the frequency of each variable was compared between patterns and with the population frequency. White matter injury was the most common MRI pattern (45%), followed by grey matter injury (14%), normal imaging (13%), malformations (10%), focal vascular insults (9%), and miscellaneous patterns (7%). Parity, birth gestation, level of neonatal care, Apgar score, and time to established respiration varied between MRI patterns (ppatterns, future exploration of causal pathways might be facilitated when performed in pathogenically defined groups. © 2013 Mac Keith Press.

  18. The plant pathogen Pseudomonas syringae pv. tomato is genetically monomorphic and under strong selection to evade tomato immunity.

    Directory of Open Access Journals (Sweden)

    Rongman Cai

    2011-08-01

    Full Text Available Recently, genome sequencing of many isolates of genetically monomorphic bacterial human pathogens has given new insights into pathogen microevolution and phylogeography. Here, we report a genome-based micro-evolutionary study of a bacterial plant pathogen, Pseudomonas syringae pv. tomato. Only 267 mutations were identified between five sequenced isolates in 3,543,009 nt of analyzed genome sequence, which suggests a recent evolutionary origin of this pathogen. Further analysis with genome-derived markers of 89 world-wide isolates showed that several genotypes exist in North America and in Europe indicating frequent pathogen movement between these world regions. Genome-derived markers and molecular analyses of key pathogen loci important for virulence and motility both suggest ongoing adaptation to the tomato host. A mutational hotspot was found in the type III-secreted effector gene hopM1. These mutations abolish the cell death triggering activity of the full-length protein indicating strong selection for loss of function of this effector, which was previously considered a virulence factor. Two non-synonymous mutations in the flagellin-encoding gene fliC allowed identifying a new microbe associated molecular pattern (MAMP in a region distinct from the known MAMP flg22. Interestingly, the ancestral allele of this MAMP induces a stronger tomato immune response than the derived alleles. The ancestral allele has largely disappeared from today's Pto populations suggesting that flagellin-triggered immunity limits pathogen fitness even in highly virulent pathogens. An additional non-synonymous mutation was identified in flg22 in South American isolates. Therefore, MAMPs are more variable than expected differing even between otherwise almost identical isolates of the same pathogen strain.

  19. Rates and patterns of molecular evolution in freshwater versus terrestrial insects.

    Science.gov (United States)

    Mitterboeck, T Fatima; Fu, Jinzhong; Adamowicz, Sarah J

    2016-11-01

    Insect lineages have crossed between terrestrial and aquatic habitats many times, for both immature and adult life stages. We explore patterns in molecular evolutionary rates between 42 sister pairs of related terrestrial and freshwater insect clades using publicly available protein-coding DNA sequence data from the orders Coleoptera, Diptera, Lepidoptera, Hemiptera, Mecoptera, Trichoptera, and Neuroptera. We furthermore test for habitat-associated convergent molecular evolution in the cytochrome c oxidase subunit I (COI) gene in general and at a particular amino acid site previously reported to exhibit habitat-linked convergence within an aquatic beetle group. While ratios of nonsynonymous-to-synonymous substitutions across available loci were higher in terrestrial than freshwater-associated taxa in 26 of 42 lineage pairs, a stronger trend was observed (20 of 31, p binomial = 0.15, p Wilcoxon = 0.017) when examining only terrestrial-aquatic pairs including fully aquatic taxa. We did not observe any widespread changes at particular amino acid sites in COI associated with habitat shifts, although there may be general differences in selection regime linked to habitat.

  20. Recent Advances in Molecular Technologies and Their Application in Pathogen Detection in Foods with Particular Reference to Yersinia

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    Jin Gui

    2011-01-01

    Full Text Available Yersinia enterocolitica is an important zoonotic pathogen that can cause yersiniosis in humans and animals. Food has been suggested to be the main source of yersiniosis. It is critical for the researchers to be able to detect Yersinia or any other foodborne pathogen with increased sensitivity and specificity, as well as in real-time, in the case of a foodborne disease outbreak. Conventional detection methods are known to be labor intensive, time consuming, or expensive. On the other hand, more sensitive molecular-based detection methods like next generation sequencing, microarray, and many others are capable of providing faster results. DNA testing is now possible on a single molecule, and high-throughput analysis allows multiple detection reactions to be performed at once, thus allowing a range of characteristics to be rapidly and simultaneously determined. Despite better detection efficiencies, results derived using molecular biology methods can be affected by the various food matrixes. With the improvements in sample preparation, data analysis, and testing procedures, molecular detection techniques will likely continue to simplify and increase the speed of detection while simultaneously improving the sensitivity and specificity for tracking pathogens in food matrices.

  1. Association between selected oral pathogens and gastric precancerous lesions.

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    Christian R Salazar

    Full Text Available We examined whether colonization of selected oral pathogens is associated with gastric precancerous lesions in a cross-sectional study. A total of 119 participants were included, of which 37 were cases of chronic atrophic gastritis, intestinal metaplasia, or dysplasia. An oral examination was performed to measure periodontal indices. Plaque and saliva samples were tested with real-time quantitative PCR for DNA levels of pathogens related to periodontal disease (Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Actinobacillus actinomycetemcomitans and dental caries (Streptococcus mutans and S. sobrinus. There were no consistent associations between DNA levels of selected bacterial species and gastric precancerous lesions, although an elevated but non-significant odds ratio (OR for gastric precancerous lesions was observed in relation to increasing colonization of A. actinomycetemcomitans (OR = 1.36 for one standard deviation increase, 95% Confidence Interval = 0.87-2.12, P. gingivalis (OR = 1.12, 0.67-1.88 and T. denticola (OR = 1.34, 0.83-2.12 measured in plaque. To assess the influence of specific long-term infection, stratified analyses by levels of periodontal indices were conducted. A. actinomycetemcomitans was significantly associated with gastric precancerous lesions (OR = 2.51, 1.13-5.56 among those with ≥ median of percent tooth sites with PD ≥ 3 mm, compared with no association among those below the median (OR = 0.86, 0.43-1.72. A significantly stronger relationship was observed between the cumulative bacterial burden score of periodontal disease-related pathogens and gastric precancerous lesions among those with higher versus lower levels of periodontal disease indices (p-values for interactions: 0.03-0.06. Among individuals with periodontal disease, high levels of colonization of periodontal pathogens are associated with an increased risk of gastric precancerous lesions.

  2. Extracellular ATP acts as a damage associated molecular pattern (DAMP signal in plants

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    Kiwamu eTanaka

    2014-09-01

    Full Text Available As sessile organisms, plants have evolved effective mechanisms to protect themselves from environmental stresses. Damaged (i.e., wounded plants recognize a variety of endogenous molecules as danger signals, referred to as damage-associated molecular patterns (DAMPs. ATP is among the molecules that are released by cell damage, and recent evidence suggests that ATP can serve as a DAMP. Although little studied in plants, extracellular ATP is well known for its signaling role in animals, including acting as a DAMP during the inflammatory response and wound healing. If ATP acts outside the cell, then it is reasonable to expect that it is recognized by a plasma membrane-localized receptor. Recently, DORN1, a lectin receptor kinase, was shown to recognize extracellular ATP in Arabidopsis. DORN1 is the founding member of a new purinoceptor subfamily, P2K (P2 receptor Kinase, which is plant-specific. P2K1 (DORN1 is required for ATP-induced cellular responses (e.g., cytosolic Ca2+ elevation, MAPK phosphorylation, and gene expression. Genetic analysis of loss-of-function mutants and overexpression lines showed that P2K1 participates in the plant wound response, consistent with the role of ATP as a DAMP. In this review, we summarize past research on the roles and mechanisms of extracellular ATP signaling in plants, and discuss the direction of the future research of extracellular ATP as a DAMP signal.

  3. Genome-Wide Analysis in Three Fusarium Pathogens Identifies Rapidly Evolving Chromosomes and Genes Associated with Pathogenicity

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    Sperschneider, Jana; Gardiner, Donald M.; Thatcher, Louise F.; Lyons, Rebecca; Singh, Karam B.; Manners, John M.; Taylor, Jennifer M.

    2015-01-01

    Pathogens and hosts are in an ongoing arms race and genes involved in host–pathogen interactions are likely to undergo diversifying selection. Fusarium plant pathogens have evolved diverse infection strategies, but how they interact with their hosts in the biotrophic infection stage remains puzzling. To address this, we analyzed the genomes of three Fusarium plant pathogens for genes that are under diversifying selection. We found a two-speed genome structure both on the chromosome and gene group level. Diversifying selection acts strongly on the dispensable chromosomes in Fusarium oxysporum f. sp. lycopersici and on distinct core chromosome regions in Fusarium graminearum, all of which have associations with virulence. Members of two gene groups evolve rapidly, namely those that encode proteins with an N-terminal [SG]-P-C-[KR]-P sequence motif and proteins that are conserved predominantly in pathogens. Specifically, 29 F. graminearum genes are rapidly evolving, in planta induced and encode secreted proteins, strongly pointing toward effector function. In summary, diversifying selection in Fusarium is strongly reflected as genomic footprints and can be used to predict a small gene set likely to be involved in host–pathogen interactions for experimental verification. PMID:25994930

  4. Allopatric tuberculosis host–pathogen relationships are associated with greater pulmonary impairment

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    Pasipanodya, Jotam G.; Moonan, Patrick K.; Vecino, Edgar; Miller, Thaddeus L.; Fernandez, Michel; Slocum, Philip; Drewyer, Gerry; Weis, Stephen E.

    2015-01-01

    Background Host pathogen relationships can be classified as allopatric, when the pathogens originated from separate, non-overlapping geographic areas from the host; or sympatric, when host and pathogen shared a common ancestral geographic location. It remains unclear if host–pathogen relationships, as defined by phylogenetic lineage, influence clinical outcome. We sought to examine the association between allopatric and sympatric phylogenetic Mycobacterium tuberculosis lineages and pulmonary impairment after tuberculosis (PIAT). Methods Pulmonary function tests were performed on patients 16 years of age and older who had received ≥20 weeks of treatment for culture-confirmed M. tuberculosis complex. Forced Expiratory Volume in 1 min (FEV1) ≥80%, Forced Vital Capacity (FVC) ≥80% and FEV1/FVC >70% of predicted were considered normal. Other results defined pulmonary impairment. Spoligotype and 12-locus mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) were used to assign phylogenetic lineage. PIAT severity was compared between host–pathogen relationships which were defined by geography and ethnic population. We used multivariate logistic regression modeling to calculate adjusted odds ratios (aOR) between phylogenetic lineage and PIAT. Results Self-reported continental ancestry was correlated with Mycobacterium. tuberculosis lineage (p allopatric host–pathogen relationships and PIAT was 1.8 (95% confidence interval [CI]: 1.1, 2.9) compared to sympatric relationships. Smoking >30 pack-years was also associated with PIAT (aOR: 3.2; 95% CI: 1.5, 7.2) relative to smoking allopatric–host–pathogen relationship were more likely to have PIAT than patients with disease from sympatric–host–pathogen relationship infection. Further study of this association may identify ways that treatment and preventive efforts can be tailored to specific lineages and racial/ethnic populations. PMID:23501297

  5. Allopatric tuberculosis host-pathogen relationships are associated with greater pulmonary impairment.

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    Pasipanodya, Jotam G; Moonan, Patrick K; Vecino, Edgar; Miller, Thaddeus L; Fernandez, Michel; Slocum, Philip; Drewyer, Gerry; Weis, Stephen E

    2013-06-01

    Host pathogen relationships can be classified as allopatric, when the pathogens originated from separate, non-overlapping geographic areas from the host; or sympatric, when host and pathogen shared a common ancestral geographic location. It remains unclear if host-pathogen relationships, as defined by phylogenetic lineage, influence clinical outcome. We sought to examine the association between allopatric and sympatric phylogenetic Mycobacterium tuberculosis lineages and pulmonary impairment after tuberculosis (PIAT). Pulmonary function tests were performed on patients 16 years of age and older who had received ≥20 weeks of treatment for culture-confirmed M. tuberculosis complex. Forced Expiratory Volume in 1 min (FEV1) ≥80%, Forced Vital Capacity (FVC) ≥80% and FEV1/FVC >70% of predicted were considered normal. Other results defined pulmonary impairment. Spoligotype and 12-locus mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) were used to assign phylogenetic lineage. PIAT severity was compared between host-pathogen relationships which were defined by geography and ethnic population. We used multivariate logistic regression modeling to calculate adjusted odds ratios (aOR) between phylogenetic lineage and PIAT. Self-reported continental ancestry was correlated with Mycobacterium. tuberculosis lineage (pallopatric host-pathogen relationships and PIAT was 1.8 (95% confidence interval [CI]: 1.1, 2.9) compared to sympatric relationships. Smoking >30 pack-years was also associated with PIAT (aOR: 3.2; 95% CI: 1.5, 7.2) relative to smoking allopatric-host-pathogen relationship were more likely to have PIAT than patients with disease from sympatric-host-pathogen relationship infection. Further study of this association may identify ways that treatment and preventive efforts can be tailored to specific lineages and racial/ethnic populations. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Duplications and losses in gene families of rust pathogens highlight putative effectors

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    Amanda L. Pendleton

    2014-06-01

    Full Text Available Rust fungi are a group of fungal pathogens that cause some of the world’s most destructive diseases of trees and crops. A shared characteristic among rust fungi is obligate biotrophy, the inability to complete a lifecycle without a host. This dependence on a host species likely affects patterns of gene expansion, contraction, and innovation within rust pathogen genomes. The establishment of disease by biotrophic pathogens is reliant upon effector proteins that are encoded in the fungal genome and secreted from the pathogen into the host’s cell apoplast or within the cells. This study uses a comparative genomic approach to elucidate putative effectors and determine their evolutionary histories. We used OrthoMCL to identify nearly 20,000 gene families in proteomes of sixteen diverse fungal species, which include fifteen basidiomycetes and one ascomycete. We inferred patterns of duplication and loss for each gene family and identified families with distinctive patterns of expansion/contraction associated with the evolution of rust fungal genomes. To recognize potential contributors for the unique features of rust pathogens, we identified families harboring secreted proteins that: i arose or expanded in rust pathogens relative to other fungi, or ii contracted or were lost in rust fungal genomes. While the origin of rust fungi appears to be associated with considerable gene loss, there are many gene duplications associated with each sampled rust fungal genome. We also highlight two putative effector gene families that have expanded in Cqf that we hypothesize have roles in pathogenicity.

  7. Evolution and genome architecture in fungal plant pathogens.

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    Möller, Mareike; Stukenbrock, Eva H

    2017-12-01

    The fungal kingdom comprises some of the most devastating plant pathogens. Sequencing the genomes of fungal pathogens has shown a remarkable variability in genome size and architecture. Population genomic data enable us to understand the mechanisms and the history of changes in genome size and adaptive evolution in plant pathogens. Although transposable elements predominantly have negative effects on their host, fungal pathogens provide prominent examples of advantageous associations between rapidly evolving transposable elements and virulence genes that cause variation in virulence phenotypes. By providing homogeneous environments at large regional scales, managed ecosystems, such as modern agriculture, can be conducive for the rapid evolution and dispersal of pathogens. In this Review, we summarize key examples from fungal plant pathogen genomics and discuss evolutionary processes in pathogenic fungi in the context of molecular evolution, population genomics and agriculture.

  8. Molecular Profiling of the Phytophthora plurivora Secretome: A Step towards Understanding the Cross-Talk between Plant Pathogenic Oomycetes and Their Hosts

    Science.gov (United States)

    Fleischmann, Frank; Dalio, Ronaldo J. D.; Di Maro, Antimo; Scognamiglio, Monica; Fiorentino, Antonio; Parente, Augusto; Osswald, Wolfgang; Chambery, Angela

    2014-01-01

    The understanding of molecular mechanisms underlying host–pathogen interactions in plant diseases is of crucial importance to gain insights on different virulence strategies of pathogens and unravel their role in plant immunity. Among plant pathogens, Phytophthora species are eliciting a growing interest for their considerable economical and environmental impact. Plant infection by Phytophthora phytopathogens is a complex process coordinated by a plethora of extracellular signals secreted by both host plants and pathogens. The characterization of the repertoire of effectors secreted by oomycetes has become an active area of research for deciphering molecular mechanisms responsible for host plants colonization and infection. Putative secreted proteins by Phytophthora species have been catalogued by applying high-throughput genome-based strategies and bioinformatic approaches. However, a comprehensive analysis of the effective secretome profile of Phytophthora is still lacking. Here, we report the first large-scale profiling of P. plurivora secretome using a shotgun LC-MS/MS strategy. To gain insight on the molecular signals underlying the cross-talk between plant pathogenic oomycetes and their host plants, we also investigate the quantitative changes of secreted protein following interaction of P. plurivora with the root exudate of Fagus sylvatica which is highly susceptible to the root pathogen. We show that besides known effectors, the expression and/or secretion levels of cell-wall-degrading enzymes were altered following the interaction with the host plant root exudate. In addition, a characterization of the F. sylvatica root exudate was performed by NMR and amino acid analysis, allowing the identification of the main released low-molecular weight components, including organic acids and free amino acids. This study provides important insights for deciphering the extracellular network involved in the highly susceptible P. plurivora-F. sylvatica interaction

  9. Artemisinin resistance in Plasmodium falciparum is associated with an altered temporal pattern of transcription

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    Newton Paul N

    2011-08-01

    Full Text Available Abstract Background Artemisinin resistance in Plasmodium falciparum malaria has emerged in Western Cambodia. This is a major threat to global plans to control and eliminate malaria as the artemisinins are a key component of antimalarial treatment throughout the world. To identify key features associated with the delayed parasite clearance phenotype, we employed DNA microarrays to profile the physiological gene expression pattern of the resistant isolates. Results In the ring and trophozoite stages, we observed reduced expression of many basic metabolic and cellular pathways which suggests a slower growth and maturation of these parasites during the first half of the asexual intraerythrocytic developmental cycle (IDC. In the schizont stage, there is an increased expression of essentially all functionalities associated with protein metabolism which indicates the prolonged and thus increased capacity of protein synthesis during the second half of the resistant parasite IDC. This modulation of the P. falciparum intraerythrocytic transcriptome may result from differential expression of regulatory proteins such as transcription factors or chromatin remodeling associated proteins. In addition, there is a unique and uniform copy number variation pattern in the Cambodian parasites which may represent an underlying genetic background that contributes to the resistance phenotype. Conclusions The decreased metabolic activities in the ring stages are consistent with previous suggestions of higher resilience of the early developmental stages to artemisinin. Moreover, the increased capacity of protein synthesis and protein turnover in the schizont stage may contribute to artemisinin resistance by counteracting the protein damage caused by the oxidative stress and/or protein alkylation effect of this drug. This study reports the first global transcriptional survey of artemisinin resistant parasites and provides insight to the complexities of the molecular basis

  10. First molecular identification of the vertebrate hosts of Culicoides imicola in Europe and a review of its blood-feeding patterns worldwide: implications for the transmission of bluetongue disease and African horse sickness.

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    Martínez-DE LA Puente, J; Navarro, J; Ferraguti, M; Soriguer, R; Figuerola, J

    2017-12-01

    Culicoides (Diptera: Ceratopogonidae) are vectors of pathogens that affect wildlife, livestock and, occasionally, humans. Culicoides imicola (Kieffer, 1913) is considered to be the main vector of the pathogens that cause bluetongue disease (BT) and African horse sickness (AHS) in southern Europe. The study of blood-feeding patterns in Culicoides is an essential step towards understanding the epidemiology of these pathogens. Molecular tools that increase the accuracy and sensitivity of traditional methods have been developed to identify the hosts of potential insect vectors. However, to the present group's knowledge, molecular studies that identify the hosts of C. imicola in Europe are lacking. The present study genetically characterizes the barcoding region of C. imicola trapped on farms in southern Spain and identifies its vertebrate hosts in the area. The report also reviews available information on the blood-feeding patterns of C. imicola worldwide. Culicoides imicola from Spain feed on blood of six mammals that include species known to be hosts of the BT and AHS viruses. This study provides evidence of the importance of livestock as sources of bloodmeals for C. imicola and the relevance of this species in the transmission of BT and AHS viruses in Europe. © 2017 The Royal Entomological Society.

  11. The Emerging Role of Complement Lectin Pathway in Trypanosomatids: Molecular Bases in Activation, Genetic Deficiencies, Susceptibility to Infection, and Complement System-Based Therapeutics

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    Ingrid Evans-Osses

    2013-01-01

    Full Text Available The innate immune system is evolutionary and ancient and is the pivotal line of the host defense system to protect against invading pathogens and abnormal self-derived components. Cellular and molecular components are involved in recognition and effector mechanisms for a successful innate immune response. The complement lectin pathway (CLP was discovered in 1990. These new components at the complement world are very efficient. Mannan-binding lectin (MBL and ficolin not only recognize many molecular patterns of pathogens rapidly to activate complement but also display several strategies to evade innate immunity. Many studies have shown a relation between the deficit of complement factors and susceptibility to infection. The recently discovered CLP was shown to be important in host defense against protozoan microbes. Although the recognition of pathogen-associated molecular patterns by MBL and Ficolins reveal efficient complement activations, an increase in deficiency of complement factors and diversity of parasite strategies of immune evasion demonstrate the unsuccessful effort to control the infection. In the present paper, we will discuss basic aspects of complement activation, the structure of the lectin pathway components, genetic deficiency of complement factors, and new therapeutic opportunities to target the complement system to control infection.

  12. Rapid and Accurate Molecular Identification of the Emerging Multidrug-Resistant Pathogen Candida auris.

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    Kordalewska, Milena; Zhao, Yanan; Lockhart, Shawn R; Chowdhary, Anuradha; Berrio, Indira; Perlin, David S

    2017-08-01

    Candida auris is an emerging multidrug-resistant fungal pathogen causing nosocomial and invasive infections associated with high mortality. C. auris is commonly misidentified as several different yeast species by commercially available phenotypic identification platforms. Thus, there is an urgent need for a reliable diagnostic method. In this paper, we present fast, robust, easy-to-perform and interpret PCR and real-time PCR assays to identify C. auris and related species: Candida duobushaemulonii , Candida haemulonii , and Candida lusitaniae Targeting rDNA region nucleotide sequences, primers specific for C. auris only or C. auris and related species were designed. A panel of 140 clinical fungal isolates was used in both PCR and real-time PCR assays followed by electrophoresis or melting temperature analysis, respectively. The identification results from the assays were 100% concordant with DNA sequencing results. These molecular assays overcome the deficiencies of existing phenotypic tests to identify C. auris and related species. Copyright © 2017 Kordalewska et al.

  13. Molecular epidemiological survey of bacterial and parasitic pathogens in hard ticks from eastern China.

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    Liu, Xiang-Ye; Gong, Xiang-Yao; Zheng, Chen; Song, Qi-Yuan; Chen, Ting; Wang, Jing; Zheng, Jie; Deng, Hong-Kuan; Zheng, Kui-Yang

    2017-03-01

    Ticks are able to transmit various pathogens-viruses, bacteria, and parasites-to their host during feeding. Several molecular epidemiological surveys have been performed to evaluate the risk of tick-borne pathogens in China, but little is known about pathogens circulating in ticks from eastern China. Therefore, this study aimed to investigate the presence of bacteria and parasites in ticks collected from Xuzhou, a 11258km 2 region in eastern China. In the present study, ticks were collected from domestic goats and grasses in urban districts of Xuzhou region from June 2015 to July 2016. After tick species identification, the presence of tick-borne bacterial and parasitic pathogens, including Anaplasma phagocytophilum, Borrelia burgdorferi, Rickettsia sp., Bartonella sp., Babesia sp., and Theileria sp., was established via conventional or nested polymerase chain reaction assays (PCR) and sequence analysis. Finally, a total of 500 questing adult ticks, identified as Haemaphysalis longicornis, were investigated. Among them, 28/500 tick samples (5.6%) were infected with A. phagocytophilum, and 23/500 (4.6%) with Theileria luwenshuni, whereas co-infection with these pathogens was detected in only 1/51 (2%) of all infected ticks. In conclusion, H. longicornis is the dominant tick species in the Xuzhou region and plays an important role in zoonotic pathogen transmission. Both local residents and animals are at a significant risk of exposure to anaplasmosis and theileriosis, due to the high rates of A. phagocytophilum and T. luwenshuni tick infection. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Measuring distance through dense weighted networks: The case of hospital-associated pathogens.

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    Tjibbe Donker

    2017-08-01

    Full Text Available Hospital networks, formed by patients visiting multiple hospitals, affect the spread of hospital-associated infections, resulting in differences in risks for hospitals depending on their network position. These networks are increasingly used to inform strategies to prevent and control the spread of hospital-associated pathogens. However, many studies only consider patients that are received directly from the initial hospital, without considering the effect of indirect trajectories through the network. We determine the optimal way to measure the distance between hospitals within the network, by reconstructing the English hospital network based on shared patients in 2014-2015, and simulating the spread of a hospital-associated pathogen between hospitals, taking into consideration that each intermediate hospital conveys a delay in the further spread of the pathogen. While the risk of transferring a hospital-associated pathogen between directly neighbouring hospitals is a direct reflection of the number of shared patients, the distance between two hospitals far-away in the network is determined largely by the number of intermediate hospitals in the network. Because the network is dense, most long distance transmission chains in fact involve only few intermediate steps, spreading along the many weak links. The dense connectivity of hospital networks, together with a strong regional structure, causes hospital-associated pathogens to spread from the initial outbreak in a two-step process: first, the directly surrounding hospitals are affected through the strong connections, second all other hospitals receive introductions through the multitude of weaker links. Although the strong connections matter for local spread, weak links in the network can offer ideal routes for hospital-associated pathogens to travel further faster. This hold important implications for infection prevention and control efforts: if a local outbreak is not controlled in time

  15. Lipoteichoic acid is an important microbe-associated molecular pattern of Lactobacillus rhamnosus GG

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    Claes Ingmar JJ

    2012-12-01

    Full Text Available Abstract Background Probiotic bacteria are increasingly used as immunomodulatory agents. Yet detailed molecular knowledge on the immunomodulatory molecules of these bacteria is lagging behind. Lipoteichoic acid (LTA is considered a major microbe-associated molecular pattern (MAMP of Gram-positive bacteria. However, many details and quantitative data on its immune signalling capacity are still unknown, especially in beneficial bacteria. Recently, we have demonstrated that a dltD mutant of the model probiotic Lactobacillus rhamnosus GG (LGG, having modified LTA molecules, has an enhanced probiotic efficacy in a DSS-induced colitis model as compared to wild-type. Results In this study, the importance of D-alanylated and acylated LTA for the pro-inflammatory activity of LGG was studied in vitro. Purified native LTA of LGG wild-type exhibited a concentration-dependent activation of NF-κB signalling in HEK293T cells after interaction with TLR2/6, but not with TLR2 alone. Chemical deacylation of LTA interfered with the TLR2/6 interaction, while a moderate effect was observed with chemical dealanylation. Similarly, the dltD mutant of LGG exhibited a significantly reduced capacity to activate TLR2/6-dependent NF-κB signalling in a HEK293T reporter cell line compared to wild-type. In addition, the dltD mutant of LGG showed a reduced induction of mRNA of the chemokine IL-8 in the Caco-2 epithelial cell line compared to wild-type. Experiments with highly purified LTA of LGG confirmed that LTA is a crucial factor for IL-8 mRNA induction in Caco-2 epithelial cells. Chemical dealanylation and deacylation reduced IL-8 mRNA expression. Conclusions Taken together, our results indicate that LTA of LGG is a crucial MAMP with pro-inflammatory activities such as IL-8 induction in intestinal epithelial cells and NF-κB induction in HEK293T cells via TLR2/6 interaction. The lipid chains of LGG LTA are needed for these activities, while also the D-alanine substituents

  16. Pattern-recognition receptors: signaling pathways and dysregulation in canine chronic enteropathies-brief review.

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    Heilmann, Romy M; Allenspach, Karin

    2017-11-01

    Pattern-recognition receptors (PRRs) are expressed by innate immune cells and recognize pathogen-associated molecular patterns (PAMPs) as well as endogenous damage-associated molecular pattern (DAMP) molecules. With a large potential for synergism or convergence between their signaling pathways, PRRs orchestrate a complex interplay of cellular mediators and transcription factors, and thus play a central role in homeostasis and host defense. Aberrant activation of PRR signaling, mutations of the receptors and/or their downstream signaling molecules, and/or DAMP/PAMP complex-mediated receptor signaling can potentially lead to chronic auto-inflammatory diseases or development of cancer. PRR signaling pathways appear to also present an interesting new avenue for the modulation of inflammatory responses and to serve as potential novel therapeutic targets. Evidence for a dysregulation of the PRR toll-like receptor (TLR)2, TLR4, TLR5, and TLR9, nucleotide-binding oligomerization domain-containing protein (NOD)2, and the receptor of advanced glycation end products (RAGE) exists in dogs with chronic enteropathies. We describe the TLR, NOD2, and RAGE signaling pathways and evaluate the current veterinary literature-in comparison to human medicine-to determine the role of TLRs, NOD2, and RAGE in canine chronic enteropathies.

  17. Network Analysis Reveals a Common Host–Pathogen Interaction Pattern in Arabidopsis Immune Responses

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    Hong Li

    2017-05-01

    Full Text Available Many plant pathogens secrete virulence effectors into host cells to target important proteins in host cellular network. However, the dynamic interactions between effectors and host cellular network have not been fully understood. Here, an integrative network analysis was conducted by combining Arabidopsis thaliana protein–protein interaction network, known targets of Pseudomonas syringae and Hyaloperonospora arabidopsidis effectors, and gene expression profiles in the immune response. In particular, we focused on the characteristic network topology of the effector targets and differentially expressed genes (DEGs. We found that effectors tended to manipulate key network positions with higher betweenness centrality. The effector targets, especially those that are common targets of an individual effector, tended to be clustered together in the network. Moreover, the distances between the effector targets and DEGs increased over time during infection. In line with this observation, pathogen-susceptible mutants tended to have more DEGs surrounding the effector targets compared with resistant mutants. Our results suggest a common plant–pathogen interaction pattern at the cellular network level, where pathogens employ potent local impact mode to interfere with key positions in the host network, and plant organizes an in-depth defense by sequentially activating genes distal to the effector targets.

  18. Using next-generation sequencing to develop molecular diagnostics for Pseudoperonospora cubensis, the cucurbit downy mildew pathogen

    Science.gov (United States)

    Advances in Next Generation Sequencing (NGS) allow for rapid development of genomics resources needed to generate molecular diagnostics assays for infectious agents. NGS approaches are particularly helpful for organisms that cannot be cultured, such as the downy mildew pathogens, a group of biotrop...

  19. Detection of virulence-associated genes in pathogenic and commensal avian Escherichia coli isolates.

    Science.gov (United States)

    Paixão, A C; Ferreira, A C; Fontes, M; Themudo, P; Albuquerque, T; Soares, M C; Fevereiro, M; Martins, L; Corrêa de Sá, M I

    2016-07-01

    Poultry colibacillosis due to Avian Pathogenic Escherichia coli (APEC) is responsible for several extra-intestinal pathological conditions, leading to serious economic damage in poultry production. The most commonly associated pathologies are airsacculitis, colisepticemia, and cellulitis in broiler chickens, and salpingitis and peritonitis in broiler breeders. In this work a total of 66 strains isolated from dead broiler breeders affected with colibacillosis and 61 strains from healthy broilers were studied. Strains from broiler breeders were typified with serogroups O2, O18, and O78, which are mainly associated with disease. The serogroup O78 was the most prevalent (58%). All the strains were checked for the presence of 11 virulence genes: 1) arginine succinyltransferase A (astA); ii) E.coli hemeutilization protein A (chuA); iii) colicin V A/B (cvaA/B); iv) fimbriae mannose-binding type 1 (fimC); v) ferric yersiniabactin uptake A (fyuA); vi) iron-repressible high-molecular-weight proteins 2 (irp2); vii) increased serum survival (iss); viii) iron-uptake systems of E.coli D (iucD); ix) pielonefritis associated to pili C (papC); x) temperature sensitive haemaglutinin (tsh), and xi) vacuolating autotransporter toxin (vat), by Multiplex-PCR. The results showed that all genes are present in both commensal and pathogenic E. coli strains. The iron uptake-related genes and the serum survival gene were more prevalent among APEC. The adhesin genes, except tsh, and the toxin genes, except astA, were also more prevalent among APEC isolates. Except for astA and tsh, APEC strains harbored the majority of the virulence-associated genes studied and fimC was the most prevalent gene, detected in 96.97 and 88.52% of APEC and AFEC strains, respectively. Possession of more than one iron transport system seems to play an important role on APEC survival. © 2016 Poultry Science Association Inc.

  20. Modulation of Quorum Sensing in a Gram-Positive Pathogen by Linear Molecularly Imprinted Polymers with Anti-infective Properties.

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    Motib, Anfal; Guerreiro, Antonio; Al-Bayati, Firas; Piletska, Elena; Manzoor, Irfan; Shafeeq, Sulman; Kadam, Anagha; Kuipers, Oscar; Hiller, Luisa; Cowen, Todd; Piletsky, Sergey; Andrew, Peter W; Yesilkaya, Hasan

    2017-12-22

    We describe the development, characterization, and biological testing of a new type of linear molecularly imprinted polymer (LMIP) designed to act as an anti-infective by blocking the quorum sensing (QS) mechanism and so abrogating the virulence of the pathogen Streptococcus pneumoniae. The LMIP is prepared (polymerized) in presence of a template molecule, but unlike in traditional molecular imprinting approaches, no cross-linker is used. This results in soluble low-molecular-weight oligomers that can act as a therapeutic agent in vitro and in vivo. The LMIP was characterized by mass spectrometry to determine its monomer composition. Fragments identified were then aligned along the peptide template by computer modeling to predict the possible monomer sequence of the LMIP. These findings provide a proof of principle that LMIPs can be used to block QS, thus setting the stage for the development of LMIPs a novel drug-discovery platform and class of materials to target Gram-positive pathogens. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Current Status of Conventional and Molecular Interventions for Blast Resistance in Rice

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    Deepti Srivastava

    2017-11-01

    Full Text Available Pyricularia oryzae anamorph of Magnaporthe oryzae is one of the most notorious fungal pathogens causing severe economic loss in rice production worldwide. Various methods, viz. cultural, biological and molecular approaches, are utilized to counteract this pathogen. Moreover, some tolerant or resistant rice varieties have been developed with the help of breeding programmes. Isolation and molecular characterization of different blast resistance genes now open the gate for new possibilities to elucidate the actual allelic variants of these genes via various molecular breeding and transgenic approaches. However, the behavioral pattern of this fungus breakups the resistance barriers in the resistant or tolerant rice varieties. This host-pathogen barrier will be possibly countered in future research by comparative genomics data from available genome sequence data of rice and M. oryzae for durable resistance. Present review emphasized fascinating recent updates, new molecular breeding approaches, transgenic and genomics approaches (i.e. miRNA and genome editing for the management of blast disease in rice. The updated information will be helpful for the durable, resistance breeding programme in rice against blast pathogen.

  2. Associations between vaginal pathogenic community and bacterial vaginosis in Chinese reproductive-age women.

    Directory of Open Access Journals (Sweden)

    Zongxin Ling

    Full Text Available BACKGROUND: Bacterial vaginosis (BV is one of the most common urogenital infections among women of reproductive age that represents shifts in microbiota from Lactobacillus spp. to diverse anaerobes. The aim of our study was to evalute the diagnostic values of Gardnerella, Atopobium, Eggerthella, Megasphaera typeI, Leptotrichia/Sneathia and Prevotella, defined as a vaginal pathogenic community for BV and their associations with vaginal pH and Nugent scores. METHODS AND FINDINGS: We investigated the vaginal pathogenic bacteria and Lactobacillus spp. with species-specific real-time quantitative PCR (qPCR in 50 BV-positive and 50 BV-negative Chinese women of reproductive age. Relative to BV-negative subjects, a siginificant decline in Lactobacillus and an obvious increase in bacteria in the vaginal pathogenic community were observed in BV-postive subjects (P<0.05. With the exception of Megasphaera typeI, other vaginal pathogenic bacteria were highly predictable for BV with a better sensitivity and specificity. The vaginal pathogenic community was positively associated with vaginal pH and Nugent scores, while Lactobacillus spp., such as L. iners and L. crispatus was negatively associated with them (P<0.05. CONCLUSIONS: Our data implied that the prevalance of vaginal pathogenic bacteria as well as the depletion of Lactobacillus was highly accurate for BV diagnosis. Vaginal microbiota shifts, especially the overgrowth of the vaginal pathogenic community, showed well diagnostic values in predicting BV. Postive correlations between those vaginal pathogenic bacteria and vaginal pH, Nugent score indicated the vaginal pathogenic community rather than a single vaginal microorganism, was participated in the onset of BV directly.

  3. Characteristics in Molecular Vibrational Frequency Patterns between Agonists and Antagonists of Histamine Receptors

    Directory of Open Access Journals (Sweden)

    S. June Oh

    2012-06-01

    Full Text Available To learn the differences between the structure-activity relationship and molecular vibration-activity relationship in the ligand-receptor interaction of the histamine receptor, 47 ligands of the histamine receptor were analyzed by structural similarity and molecular vibrational frequency patterns. The radial tree that was produced by clustering analysis of molecular vibrational frequency patterns shows its potential for the functional classification of histamine receptor ligands.

  4. The Prenylflavonoid Xanthohumol Reduces Alzheimer-Like Changes and Modulates Multiple Pathogenic Molecular Pathways in the Neuro2a/APPswe Cell Model of AD

    Directory of Open Access Journals (Sweden)

    Xianfeng Huang

    2018-04-01

    Full Text Available Alzheimer’s disease (AD is a progressive neurodegenerative disorder that has proved refractory to drug treatment. Given evidence of neuroprotection in animal models of ischemic stroke, we assessed the prenylflavonoid xanthohumol from the Common Hop (Humulus lupulus L. for therapeutic potential in murine neuroblastoma N2a cells stably expressing human Swedish mutant amyloid precursor protein (N2a/APP, a well-characterized cellular model of AD. The ELISA and Western-blot analysis revealed that xanthohumol (Xn inhibited Aβ accumulation and APP processing, and that Xn ameliorated tau hyperphosphorylation via PP2A, GSK3β pathways in N2a/APP cells. The amelioration of tau hyperphosphorylation by Xn was also validated on HEK293/Tau cells, another cell line with tau hyperphosphorylation. Proteomic analysis (2D-DIGE-coupled MS revealed a total of 30 differentially expressed lysate proteins in N2a/APP vs. wild-type (WT N2a cells (N2a/WT, and a total of 21 differentially expressed proteins in lysates of N2a/APP cells in the presence or absence of Xn. Generally, these 51 differential proteins could be classified into seven main categories according to their functions, including: endoplasmic reticulum (ER stress-associated proteins; oxidative stress-associated proteins; proteasome-associated proteins; ATPase and metabolism-associated proteins; cytoskeleton-associated proteins; molecular chaperones-associated proteins, and others. We used Western-blot analysis to validate Xn-associated changes of some key proteins in several biological/pathogenic processes. Taken together, we show that Xn reduces AD-related changes in stably transfected N2a/APP cells. The underlying mechanisms involve modulation of multiple pathogenic pathways, including those involved in ER stress, oxidative stress, proteasome molecular systems, and the neuronal cytoskeleton. These results suggest Xn may have potential for the treatment of AD and/or neuropathologically related

  5. Molecular techniques for characterisation of pathogens

    DEFF Research Database (Denmark)

    Kampmann, Marie-Louise

    Pathogens have always had a major interest to humans due to their central role in sickness and death. Influenza A annually kills at least 250,000 humans, and has been the cause of millions of further deaths during pandemic years in the past. Plague (Yersinia pestis) has been the cause of the Black...... capture for the detection of Y. pestis in samples from the Justinian plague (600 AD) as an attempt to detect this pathogen as a cause of death in the victims....

  6. Profiling the extended phenotype of plant pathogens: Challenges in Bacterial Molecular Plant Pathology.

    Science.gov (United States)

    Preston, Gail M

    2017-04-01

    One of the most fundamental questions in plant pathology is what determines whether a pathogen grows within a plant? This question is frequently studied in terms of the role of elicitors and pathogenicity factors in the triggering or overcoming of host defences. However, this focus fails to address the basic question of how the environment in host tissues acts to support or restrict pathogen growth. Efforts to understand this aspect of host-pathogen interactions are commonly confounded by several issues, including the complexity of the plant environment, the artificial nature of many experimental infection systems and the fact that the physiological properties of a pathogen growing in association with a plant can be very different from the properties of the pathogen in culture. It is also important to recognize that the phenotype and evolution of pathogen and host are inextricably linked through their interactions, such that the environment experienced by a pathogen within a host, and its phenotype within the host, is a product of both its interaction with its host and its evolutionary history, including its co-evolution with host plants. As the phenotypic properties of a pathogen within a host cannot be defined in isolation from the host, it may be appropriate to think of pathogens as having an 'extended phenotype' that is the product of their genotype, host interactions and population structure within the host environment. This article reflects on the challenge of defining and studying this extended phenotype, in relation to the questions posed below, and considers how knowledge of the phenotype of pathogens in the host environment could be used to improve disease control. What determines whether a pathogen grows within a plant? What aspects of pathogen biology should be considered in describing the extended phenotype of a pathogen within a host? How can we study the extended phenotype in ways that provide insights into the phenotypic properties of pathogens

  7. A Phytophthora sojae effector PsCRN63 forms homo-/hetero-dimers to suppress plant immunity via an inverted association manner.

    Science.gov (United States)

    Li, Qi; Zhang, Meixiang; Shen, Danyu; Liu, Tingli; Chen, Yanyu; Zhou, Jian-Min; Dou, Daolong

    2016-05-31

    Oomycete pathogens produce a large number of effectors to promote infection. Their mode of action are largely unknown. Here we show that a Phytophthora sojae effector, PsCRN63, suppresses flg22-induced expression of FRK1 gene, a molecular marker in pathogen-associated molecular patterns (PAMP)-triggered immunity (PTI). However, PsCRN63 does not suppress upstream signaling events including flg22-induced MAPK activation and BIK1 phosphorylation, indicating that it acts downstream of MAPK cascades. The PsCRN63-transgenic Arabidopsis plants showed increased susceptibility to bacterial pathogen Pseudomonas syringae pathovar tomato (Pst) DC3000 and oomycete pathogen Phytophthora capsici. The callose deposition were suppressed in PsCRN63-transgenic plants compared with the wild-type control plants. Genes involved in PTI were also down-regulated in PsCRN63-transgenic plants. Interestingly, we found that PsCRN63 forms an dimer that is mediated by inter-molecular interactions between N-terminal and C-terminal domains in an inverted association manner. Furthermore, the N-terminal and C-terminal domains required for the dimerization are widely conserved among CRN effectors, suggesting that homo-/hetero-dimerization of Phytophthora CRN effectors is required to exert biological functions. Indeed, the dimerization was required for PTI suppression and cell death-induction activities of PsCRN63.

  8. Greasy tactics in the plant-pathogen molecular arms race.

    Science.gov (United States)

    Boyle, Patrick C; Martin, Gregory B

    2015-03-01

    The modification of proteins by the attachment of fatty acids is a targeting tactic involved in mechanisms of both plant immunity and bacterial pathogenesis. The plant plasma membrane (PM) is a key battleground in the war against disease-causing microbes. This membrane is armed with an array of sensor proteins that function as a surveillance system to detect invading pathogens. Several of these sensor proteins are directed to the plasma membrane through the covalent addition of fatty acids, a process termed fatty acylation. Phytopathogens secrete effector proteins into the plant cell to subvert these surveillance mechanisms, rendering the host susceptible to infection. The targeting of effectors to specific locales within plant cells, particularly the internal face of the host PM, is critical for their virulence function. Several bacterial effectors hijack the host fatty acylation machinery to be modified and directed to this contested locale. To find and fight these fatty acylated effectors the plant leverages lipid-modified intracellular sensors. This review provides examples featuring how fatty acylation is a battle tactic used by both combatants in the molecular arms race between plants and pathogens. Also highlighted is the exploitation of a specific form of host-mediated fatty acid modification, which appears to be exclusively employed by phytopathogenic effector proteins. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  9. Peritoneal cavity lavage reduces the presence of mitochondrial damage associated molecular patterns in open abdomen patients.

    Science.gov (United States)

    Martinez-Quinones, Patricia A; McCarthy, Cameron G; Mentzer, Caleb J; Wenceslau, Camilla F; Holsten, Steven B; Webb, R Clinton; O'Malley, Keith

    2017-12-01

    Mitochondrial damage-associated molecular patterns (mtDAMPs), such as mitochondrial DNA and N-formylated peptides, are endogenous molecules released from tissue after traumatic injury. mtDAMPs are potent activators of the innate immune system. They have similarities with bacteria, which allow mtDAMPs to interact with the same pattern recognition receptors and mediate the development of systemic inflammatory response syndrome (SIRS). Current recommendations for management of an open abdomen include returning to the operating room every 48 hours for peritoneal cavity lavage until definitive procedure. These patients are often critically ill and develop SIRS. We hypothesized that mitochondrial DAMPs are present in the peritoneal cavity fluid in this setting, and that they accumulate in the interval between washouts. We conducted a prospective pilot study of critically ill adult patients undergoing open abdomen management in the surgical and trauma intensive care units. Peritoneal fluid was collected daily from 10 open abdomen patients. Specimens were analyzed via quantitative polymerase chain reaction (qPCR) for mitochondrial DNA (mtDNA), via enzyme immunoassay for DNAse activity and via Western blot analysis for the ND6 subunit of the NADH: ubiquinone oxidoreductase, an N-formylated peptide. We observed a reduction in the expression of ND6 the day after lavage of the peritoneal cavity, that was statistically different from the days with no lavage (% change in ND6 expression, postoperative from washout: -50 ± 11 vs. no washout day, 42 ± 9; p abdomen. It is possible that increased frequency of peritoneal cavity lavage may lead to decreased systemic absorption of mtDAMPs, thereby reducing the risk of SIRS. Prospective study, Case Series, Level V.

  10. Susceptibility to Lower Respiratory Infections in Childhood is Associated with Perturbation of the Cytokine Response to Pathogenic Airway Bacteria.

    Science.gov (United States)

    Vissing, Nadja Hawwa; Larsen, Jeppe Madura; Rasmussen, Morten Arendt; Chawes, Bo Lund Krogsgaard; Thysen, Anna Hammerich; Bønnelykke, Klaus; Brix, Susanne; Bisgaard, Hans

    2016-05-01

    Neonatal colonization of the airways with respiratory pathogens is associated with increased risk of lower respiratory infections (LRI) in early childhood. Therefore, we hypothesized that children developing LRI have an aberrant immune response to pathogenic bacteria in infancy. The objective was to characterize in vitro the early life systemic immune response to pathogenic bacteria and study the possible association with incidence of LRI during the first 3 years of life. The Copenhagen Prospective Studies on Asthma in Childhood2000 (COPSAC2000) is a clinical birth cohort study of 411 children born of mothers with asthma. LRI incidence was prospectively captured from 6-monthly planned visits and visits at acute respiratory episodes. The in vitro systemic immune response to Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae was characterized by the production of TNF-α, IFN-γ, IL-2, IL-5, IL-10, IL-13 and IL-17 in peripheral blood mononuclear cells isolated at age 6 months from 291 infants. Data were analyzed by Poisson regression against incidence of LRI in infancy. A multivariable model including all cytokine responses from the 3 different bacterial stimulations significantly identified children at risk of LRI (P = 0.006). The immune response pattern associated with LRI was characterized by perturbed production of several cytokines rather than production of one specific cytokine, and was independent of concurrent asthma. TNF-α and IL-5 were key drivers but did not explain the entire variation in LRI susceptibility. Children at risk of future LRI present a perturbed systemic immune response upon exposure to common airway pathogens in early life.

  11. Bacillus anthracis: una mirada molecular a un patógeno célebre Bacillus anthracis: a molecular look at a famous pathogen

    Directory of Open Access Journals (Sweden)

    María E Pavan

    2011-12-01

    molecular aspects of traditional virulence factors: capsule, protective antigen, lethal factor and edema factor are described in depth, together with virulence factors recently proposed, such as the siderophores petrobactin and bacillibactin, the S-layer adhesin and the MntA lipoprotein. It is detailed the molecular organization of megaplasmids pXO1 and pXO2, including the pathogenicity island of pXO1. The genetic skeleton of these plasmids has been observed in related species, and this could be attributed to lateral gene transfer. Finally, the two anthrax toxin protective antigen receptors, ANTXR1/TEM8 and ANTXR2/CMG2, essential for the interaction of the pathogen with the host, are presented. The molecular studies performed in recent years have greatly increased knowledge in different aspects of this microorganism and its relationship with the host, but at the same time they have raised new questions about this noted pathogen.

  12. The molecular mechanisms of signaling by cooperative assembly formation in innate immunity pathways.

    Science.gov (United States)

    Vajjhala, Parimala R; Ve, Thomas; Bentham, Adam; Stacey, Katryn J; Kobe, Bostjan

    2017-06-01

    The innate immune system is the first line of defense against infection and responses are initiated by pattern recognition receptors (PRRs) that detect pathogen-associated molecular patterns (PAMPs). PRRs also detect endogenous danger-associated molecular patterns (DAMPs) that are released by damaged or dying cells. The major PRRs include the Toll-like receptor (TLR) family members, the nucleotide binding and oligomerization domain, leucine-rich repeat containing (NLR) family, the PYHIN (ALR) family, the RIG-1-like receptors (RLRs), C-type lectin receptors (CLRs) and the oligoadenylate synthase (OAS)-like receptors and the related protein cyclic GMP-AMP synthase (cGAS). The different PRRs activate specific signaling pathways to collectively elicit responses including the induction of cytokine expression, processing of pro-inflammatory cytokines and cell-death responses. These responses control a pathogenic infection, initiate tissue repair and stimulate the adaptive immune system. A central theme of many innate immune signaling pathways is the clustering of activated PRRs followed by sequential recruitment and oligomerization of adaptors and downstream effector enzymes, to form higher-order arrangements that amplify the response and provide a scaffold for proximity-induced activation of the effector enzymes. Underlying the formation of these complexes are co-operative assembly mechanisms, whereby association of preceding components increases the affinity for downstream components. This ensures a rapid immune response to a low-level stimulus. Structural and biochemical studies have given key insights into the assembly of these complexes. Here we review the current understanding of assembly of immune signaling complexes, including inflammasomes initiated by NLR and PYHIN receptors, the myddosomes initiated by TLRs, and the MAVS CARD filament initiated by RIG-1. We highlight the co-operative assembly mechanisms during assembly of each of these complexes. Copyright

  13. Melanin targets LC3-associated phagocytosis (LAP): A novel pathogenetic mechanism in fungal disease.

    Science.gov (United States)

    Chamilos, Georgios; Akoumianaki, Tonia; Kyrmizi, Irene; Brakhage, Axel; Beauvais, Anne; Latge, Jean-Paul

    2016-05-03

    Intracellular swelling of conidia of the major human airborne fungal pathogen Aspergillus fumigatus results in surface exposure of immunostimulatory pathogen-associated molecular patterns (PAMPs) and triggers activation of a specialized autophagy pathway called LC3-associated phagocytosis (LAP) to promote fungal killing. We have recently discovered that, apart from PAMPs exposure, cell wall melanin removal during germination of A. fumigatus is a prerequisite for activation of LAP. Importantly, melanin promotes fungal pathogenicity via targeting LAP, as a melanin-deficient A. fumigatus mutant restores its virulence upon conditional inactivation of Atg5 in hematopoietic cells of mice. Mechanistically, fungal cell wall melanin selectively excludes the CYBA/p22phox subunit of NADPH oxidase from the phagosome to inhibit LAP, without interfering with signaling regulating cytokine responses. Notably, inhibition of LAP is a general property of melanin pigments, a finding with broad physiological implications.

  14. Molecular epidemiology of Blastocystis

    Directory of Open Access Journals (Sweden)

    Fadime Eroğlu

    2015-12-01

    Full Text Available Blastocystis pathogenicity and classification was newly illuminated with molecular genetic studies and recently the parasite was found in the focus of many researchers. Several molecular methods such as; polymerase chain reaction (PCR, PCR-restriction fragment length polymorphism, random amplified polymorphic DNA, real-time polymerase chain reaction and DNA sequencing analyses can be used in genotyping of Blastocystis. Blastocystis parasites may cause diarrhea, abdominal pain, bloating, gas, irritability, anorexia, cramps, vomiting, dehydration, insomnia, nausea, loss of appetite, weight loss, fatigue symptoms and also could be asymptomatic cases. In this review, it was aimed to summarize the associations between Blastocystis subtypes and pathogenicity.

  15. Association of the pitch canker pathogen Fusarium circinatum with ...

    African Journals Online (AJOL)

    Association of the pitch canker pathogen Fusarium circinatum with grass hosts in commercial pine production areas of South Africa. Cassandra L Swett, Bernice Porter, Gerda Fourie, Emma T Steenkamp, Thomas R Gordon, Michael J Wingfield ...

  16. Development and assessment of molecular diagnostic tests for 15 enteropathogens causing childhood diarrhoea: a multicentre study.

    Science.gov (United States)

    Liu, Jie; Kabir, Furqan; Manneh, Jainaba; Lertsethtakarn, Paphavee; Begum, Sharmin; Gratz, Jean; Becker, Steve M; Operario, Darwin J; Taniuchi, Mami; Janaki, Lalitha; Platts-Mills, James A; Haverstick, Doris M; Kabir, Mamun; Sobuz, Shihab U; Nakjarung, Kaewkanya; Sakpaisal, Pimmada; Silapong, Sasikorn; Bodhidatta, Ladaporn; Qureshi, Shahida; Kalam, Adil; Saidi, Queen; Swai, Ndealilia; Mujaga, Buliga; Maro, Athanasia; Kwambana, Brenda; Dione, Michel; Antonio, Martin; Kibiki, Gibson; Mason, Carl J; Haque, Rashidul; Iqbal, Najeeha; Zaidi, Anita K M; Houpt, Eric R

    2014-08-01

    Childhood diarrhoea can be caused by many pathogens that are difficult to assay in the laboratory. Molecular diagnostic techniques provide a uniform method to detect and quantify candidate enteropathogens. We aimed to develop and assess molecular tests for identification of enteropathogens and their association with disease. We developed and assessed molecular diagnostic tests for 15 enteropathogens across three platforms-PCR-Luminex, multiplex real-time PCR, and TaqMan array card-at five laboratories worldwide. We judged the analytical and clinical performance of these molecular techniques against comparator methods (bacterial culture, ELISA, and PCR) using 867 diarrhoeal and 619 non-diarrhoeal stool specimens. We also measured molecular quantities of pathogens to predict the association with diarrhoea, by univariate logistic regression analysis. The molecular tests showed very good analytical and clinical performance at all five laboratories. Comparator methods had limited sensitivity compared with the molecular techniques (20-85% depending on the target) but good specificity (median 97·3%, IQR 96·5-98·9; mean 95·2%, SD 9·1). Positive samples by comparator methods usually had higher molecular quantities of pathogens than did negative samples, across almost all platforms and for most pathogens (pMolecular diagnostic tests can be implemented successfully and with fidelity across laboratories around the world. In the case of diarrhoea, these techniques can detect pathogens with high sensitivity and ascribe diarrhoeal associations based on quantification, including in mixed infections, providing rich and unprecedented measurements of infectious causes. Bill & Melinda Gates Foundation Next Generation Molecular Diagnostics Project. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. The Cell Wall of the Human Fungal Pathogen Aspergillus fumigatus: Biosynthesis, Organization, Immune Response, and Virulence.

    Science.gov (United States)

    Latgé, Jean-Paul; Beauvais, Anne; Chamilos, Georgios

    2017-09-08

    More than 90% of the cell wall of the filamentous fungus Aspergillus fumigatus comprises polysaccharides. Biosynthesis of the cell wall polysaccharides is under the control of three types of enzymes: transmembrane synthases, which are anchored to the plasma membrane and use nucleotide sugars as substrates, and cell wall-associated transglycosidases and glycosyl hydrolases, which are responsible for remodeling the de novo synthesized polysaccharides and establishing the three-dimensional structure of the cell wall. For years, the cell wall was considered an inert exoskeleton of the fungal cell. The cell wall is now recognized as a living organelle, since the composition and cellular localization of the different constitutive cell wall components (especially of the outer layers) vary when the fungus senses changes in the external environment. The cell wall plays a major role during infection. The recognition of the fungal cell wall by the host is essential in the initiation of the immune response. The interactions between the different pattern-recognition receptors (PRRs) and cell wall pathogen-associated molecular patterns (PAMPs) orientate the host response toward either fungal death or growth, which would then lead to disease development. Understanding the molecular determinants of the interplay between the cell wall and host immunity is fundamental to combatting Aspergillus diseases.

  18. Microbiological pattern of ventilator associated pneumonia

    International Nuclear Information System (INIS)

    Ali, S.; Wahid, K.; Iqbal, Z.

    2015-01-01

    Ventilator associated pneumonia (VAP) is an important and common complication of mechanically ventilated patients. It is the leading cause of morbidity and mortality in Intensive Care Units (ICU) worldwide. The aim of study was to determine the pattern of bacteria involved in VAP in intensive care unit of Jinnah hospital Lahore. Methods: It was descriptive case series study, conducted over a period of one year on mechanically ventilated 50 patients. American Thoracic Society (ATS) guidelines recommend quantitative/semi-quantitative culture of endotracheal aspirates (ETA) or bronchoscopic aspirates/washing from the infected lung segments for the diagnosis of VAP. Hence this study was conducted to identify the types of bacteria involved in VAP in our ICU. Patients enrolled were clinically and radiologically suspected VAP, admitted in the ICU of Jinnah Hospital/Allama Iqbal Medical College (AIMC) Lahore. Bronchial washings were taken with the help of Fiber optic bronchoscope. Wherever bronchoscopy was not possible, subglottic secretions were collected with the help of sterilized catheter and sucker. Collected samples were sent to the Pathology laboratory of AIMC for aerobic culture and sensitivity. Results: Major pathogenic bacteria isolated were Gram negative (74%). Among this group E. coli, Pseudomonas, Klebsiella and Acinetobacter were the commonest organisms. Gram positive bacteria were 20%, Staphylococcus aureus (MRSA) and haemolyticus streptococci were the major isolate. In 4% cases mixed growth and in 2% cases no growth was reported. Conclusion: Major pathogenic organisms of VAP in our ICU are Gram negative bacteria. The Bacteriological culture of endobroncheal aspirates is helpful in the diagnosis and management of VAP. Emperic antibiotic therapy for VAP should cover Gram negative organisms. (author)

  19. High levels of cyclic-di-GMP in plant-associated Pseudomonas correlate with evasion of plant immunity.

    Science.gov (United States)

    Pfeilmeier, Sebastian; Saur, Isabel Marie-Luise; Rathjen, John Paul; Zipfel, Cyril; Malone, Jacob George

    2016-05-01

    The plant innate immune system employs plasma membrane-localized receptors that specifically perceive pathogen/microbe-associated molecular patterns (PAMPs/MAMPs). This induces a defence response called pattern-triggered immunity (PTI) to fend off pathogen attack. Commensal bacteria are also exposed to potential immune recognition and must employ strategies to evade and/or suppress PTI to successfully colonize the plant. During plant infection, the flagellum has an ambiguous role, acting as both a virulence factor and also as a potent immunogen as a result of the recognition of its main building block, flagellin, by the plant pattern recognition receptors (PRRs), including FLAGELLIN SENSING2 (FLS2). Therefore, strict control of flagella synthesis is especially important for plant-associated bacteria. Here, we show that cyclic-di-GMP [bis-(3'-5')-cyclic di-guanosine monophosphate], a central regulator of bacterial lifestyle, is involved in the evasion of PTI. Elevated cyclic-di-GMP levels in the pathogen Pseudomonas syringae pv. tomato (Pto) DC3000, the opportunist P. aeruginosa PAO1 and the commensal P. protegens Pf-5 inhibit flagellin synthesis and help the bacteria to evade FLS2-mediated signalling in Nicotiana benthamiana and Arabidopsis thaliana. Despite this, high cellular cyclic-di-GMP concentrations were shown to drastically reduce the virulence of Pto DC3000 during plant infection. We propose that this is a result of reduced flagellar motility and/or additional pleiotropic effects of cyclic-di-GMP signalling on bacterial behaviour. © 2015 THE AUTHORS MOLECULAR PLANT PATHOLOGY PUBLISHED BY BRITISH SOCIETY FOR PLANT PATHOLOGY AND JOHN WILEY & SONS LTD.

  20. Interchromosomal Transfer of Immune Regulation During Infection of Barley with the Powdery Mildew Pathogen

    Science.gov (United States)

    Surana, Priyanka; Xu, Ruo; Fuerst, Gregory; Chapman, Antony V. E.; Nettleton, Dan; Wise, Roger P.

    2017-01-01

    Powdery mildew pathogens colonize over 9500 plant species, causing critical yield loss. The Ascomycete fungus, Blumeria graminis f. sp. hordei (Bgh), causes powdery mildew disease in barley (Hordeum vulgare L.). Successful infection begins with penetration of host epidermal cells, culminating in haustorial feeding structures, facilitating delivery of fungal effectors to the plant and exchange of nutrients from host to pathogen. We used expression Quantitative Trait Locus (eQTL) analysis to dissect the temporal control of immunity-associated gene expression in a doubled haploid barley population challenged with Bgh. Two highly significant regions possessing trans eQTL were identified near the telomeric ends of chromosomes (Chr) 2HL and 1HS. Within these regions reside diverse resistance loci derived from barley landrace H. laevigatum (MlLa) and H. vulgare cv. Algerian (Mla1), which associate with the altered expression of 961 and 3296 genes during fungal penetration of the host and haustorial development, respectively. Regulatory control of transcript levels for 299 of the 961 genes is reprioritized from MlLa on 2HL to Mla1 on 1HS as infection progresses, with 292 of the 299 alternating the allele responsible for higher expression, including Adaptin Protein-2 subunit μ AP2M and Vesicle Associated Membrane Protein VAMP72 subfamily members VAMP721/722. AP2M mediates effector-triggered immunity (ETI) via endocytosis of plasma membrane receptor components. VAMP721/722 and SNAP33 form a Soluble N-ethylmaleimide-sensitive factor Attachment Protein REceptor (SNARE) complex with SYP121 (PEN1), which is engaged in pathogen associated molecular pattern (PAMP)-triggered immunity via exocytosis. We postulate that genes regulated by alternate chromosomal positions are repurposed as part of a conserved immune complex to respond to different pathogen attack scenarios. PMID:28790145

  1. Interchromosomal Transfer of Immune Regulation During Infection of Barley with the Powdery Mildew Pathogen

    Directory of Open Access Journals (Sweden)

    Priyanka Surana

    2017-10-01

    Full Text Available Powdery mildew pathogens colonize over 9500 plant species, causing critical yield loss. The Ascomycete fungus, Blumeria graminis f. sp. hordei (Bgh, causes powdery mildew disease in barley (Hordeum vulgare L.. Successful infection begins with penetration of host epidermal cells, culminating in haustorial feeding structures, facilitating delivery of fungal effectors to the plant and exchange of nutrients from host to pathogen. We used expression Quantitative Trait Locus (eQTL analysis to dissect the temporal control of immunity-associated gene expression in a doubled haploid barley population challenged with Bgh. Two highly significant regions possessing trans eQTL were identified near the telomeric ends of chromosomes (Chr 2HL and 1HS. Within these regions reside diverse resistance loci derived from barley landrace H. laevigatum (MlLa and H. vulgare cv. Algerian (Mla1, which associate with the altered expression of 961 and 3296 genes during fungal penetration of the host and haustorial development, respectively. Regulatory control of transcript levels for 299 of the 961 genes is reprioritized from MlLa on 2HL to Mla1 on 1HS as infection progresses, with 292 of the 299 alternating the allele responsible for higher expression, including Adaptin Protein-2 subunit μ AP2M and Vesicle Associated Membrane Protein VAMP72 subfamily members VAMP721/722. AP2M mediates effector-triggered immunity (ETI via endocytosis of plasma membrane receptor components. VAMP721/722 and SNAP33 form a Soluble N-ethylmaleimide-sensitive factor Attachment Protein REceptor (SNARE complex with SYP121 (PEN1, which is engaged in pathogen associated molecular pattern (PAMP-triggered immunity via exocytosis. We postulate that genes regulated by alternate chromosomal positions are repurposed as part of a conserved immune complex to respond to different pathogen attack scenarios.

  2. Pathogen-associated molecular pattern-triggered immunity and resistance to the root pathogen Phytophthora parasitica in Arabidopsis.

    Science.gov (United States)

    Larroque, Mathieu; Belmas, Elodie; Martinez, Thomas; Vergnes, Sophie; Ladouce, Nathalie; Lafitte, Claude; Gaulin, Elodie; Dumas, Bernard

    2013-09-01

    The cellulose binding elicitor lectin (CBEL) of the genus Phytophthora induces necrosis and immune responses in several plant species, including Arabidopsis thaliana. However, the role of CBEL-induced responses in the outcome of the interaction is still unclear. This study shows that some of CBEL-induced defence responses, but not necrosis, required the receptor-like kinase BAK1, a general regulator of basal immunity in Arabidopsis, and the production of a reactive oxygen burst mediated by respiratory burst oxidases homologues (RBOH). Screening of a core collection of 48 Arabidopsis ecotypes using CBEL uncovered a large variability in CBEL-induced necrotic responses. Analysis of non-responsive CBEL lines Ws-4, Oy-0, and Bla-1 revealed that Ws-4 and Oy-0 were also impaired in the production of the oxidative burst and expression of defence genes, whereas Bla-1 was partially affected in these responses. Infection tests using two Phytophthora parasitica strains, Pp310 and Ppn0, virulent and avirulent, respectively, on the Col-0 line showed that BAK1 and RBOH mutants were susceptible to Ppn0, suggesting that some immune responses controlled by these genes, but not CBEL-induced cell death, are required for Phytophthora parasitica resistance. However, Ws-4, Oy-0, and Bla-1 lines were not affected in Ppn0 resistance, showing that natural variability in CBEL responsiveness is not correlated to Phytophthora susceptibility. Overall, the results uncover a BAK1- and RBOH-dependent CBEL-triggered immunity essential for Phytophthora resistance and suggest that natural quantitative variation of basal immunity triggered by conserved general elicitors such as CBEL does not correlate to Phytophthora susceptibility.

  3. Human NLRP3 inflammasome activation is Nox1-4 independent

    NARCIS (Netherlands)

    van Bruggen, Robin; Köker, M. Yavuz; Jansen, Machiel; van Houdt, Michel; Roos, Dirk; Kuijpers, Taco W.; van den Berg, Timo K.

    2010-01-01

    The NLRP3 inflammasome can be activated by pathogen-associated molecular patterns or endogenous danger-associated molecular patterns. The activation of the NLRP3 inflammasome results in proteolytic activation and secretion of cytokines of the interleukin-1 (IL-1) family. The precise mode of

  4. Gram-positive bacterial lipoglycans based on a glycosylated diacylglycerol lipid anchor are microbe-associated molecular patterns recognized by TLR2.

    Directory of Open Access Journals (Sweden)

    Landry Blanc

    Full Text Available Innate immune recognition is the first line of host defense against invading microorganisms. It is a based on the detection, by pattern recognition receptors (PRRs, of invariant molecular signatures that are unique to microorganisms. TLR2 is a PRR that plays a major role in the detection of Gram-positive bacteria by recognizing cell envelope lipid-linked polymers, also called macroamphiphiles, such as lipoproteins, lipoteichoic acids and mycobacterial lipoglycans. These microbe-associated molecular patterns (MAMPs display a structure based on a lipid anchor, being either an acylated cysteine, a glycosylated diacylglycerol or a mannosyl-phosphatidylinositol respectively, and having in common a diacylglyceryl moiety. A fourth class of macroamphiphile, namely lipoglycans, whose lipid anchor is made, as for lipoteichoic acids, of a glycosylated diacylglycerol unit rather than a mannosyl-phosphatidylinositol, is found in Gram-positive bacteria and produced by certain Actinobacteria, including Micrococcus luteus, Stomatococcus mucilaginosus and Corynebacterium glutamicum. We report here that these alternative lipoglycans are also recognized by TLR2 and that they stimulate TLR2-dependant cytokine production, including IL-8, TNF-α and IL-6, and cell surface co-stimulatory molecule CD40 expression by a human macrophage cell line. However, they differ by their co-receptor requirement and the magnitude of the innate immune response they elicit. M. luteus and S. mucilaginosus lipoglycans require TLR1 for recognition by TLR2 and induce stronger responses than C. glutamicum lipoglycan, sensing of which by TLR2 is dependent on TLR6. These results expand the repertoire of MAMPs recognized by TLR2 to lipoglycans based on a glycosylated diacylglycerol lipid anchor and reinforce the paradigm that macroamphiphiles based on such an anchor, including lipoteichoic acids and alternative lipoglycans, induce TLR2-dependant innate immune responses.

  5. Virulence-associated gene pattern of porcine and human Yersinia enterocolitica biotype 4 isolates.

    Science.gov (United States)

    Schneeberger, M; Brodard, I; Overesch, G

    2015-04-02

    Yersinia enterocolitica 4/O:3 is the most important human pathogenic bioserotype in Europe and the predominant pathogenic bioserotype in slaughter pigs. Although many studies on the virulence of Y. enterocolitica strains have showed a broad spectrum of detectable factors in pigs and humans, an analysis based on a strict comparative approach and serving to verify the virulence capability of porcine Y. enterocolitica as a source for human yersiniosis is lacking. Therefore, in the present study, strains of biotype (BT) 4 isolated from Swiss slaughter pig tonsils and feces and isolates from human clinical cases were compared in terms of their spectrum of virulence-associated genes (yadA, virF, ail, inv, rovA, ymoA, ystA, ystB and myfA). An analysis of the associated antimicrobial susceptibility pattern completed the characterization. All analyzed BT 4 strains showed a nearly similar pattern, comprising the known fundamental virulence-associated genes yadA, virF, ail, inv, rovA, ymoA, ystA and myfA. Only ystB was not detectable among all analyzed isolates. Importantly, neither the source of the isolates (porcine tonsils and feces, humans) nor the serotype (ST) had any influence on the gene pattern. From these findings, it can be concluded that the presence of the full complement of virulence genes necessary for human infection is common among porcine BT 4 strains. Swiss porcine BT 4 strains not only showed antimicrobial susceptibility to chloramphenicol, cefotaxime, ceftazidime, ciprofloxacin, colistin, florfenicol, gentamicin, kanamycin, nalidixic acid, sulfamethoxazole, streptomycin, tetracycline and trimethoprim but also showed 100% antibiotic resistance to ampicillin. The human BT 4 strains revealed comparable results. However, in addition to 100% antibiotic resistance to ampicillin, 2 strains were resistant to chloramphenicol and nalidixic acid. Additionally, 1 of these strains was resistant to sulfamethoxazole. The results demonstrated that Y. enterocolitica BT 4

  6. Molecular serotyping, virulence gene profiling and pathogenicity of Streptococcus agalactiae isolated from tilapia farms in Thailand by multiplex PCR.

    Science.gov (United States)

    Kannika, K; Pisuttharachai, D; Srisapoome, P; Wongtavatchai, J; Kondo, H; Hirono, I; Unajak, S; Areechon, N

    2017-06-01

    This study aimed to biotype Streptococcus agalactiae isolated from tilapia farms in Thailand based on molecular biotyping methods and to determine the correlation between the serotype and virulence of bacteria. In addition to a biotyping (serotyping) technique based on multiplex PCR of cps genes, in this study, we developed multiplex PCR typing of Group B streptococcus (GBS) virulence genes to examine three clusters of virulence genes and their correlation with the pathogenicity of S. agalactiae. The epidemiology of S. agalactiae in Thailand was analysed to provide bacterial genetic information towards a future rational vaccine strategy for tilapia culture systems. Streptococcus agalactiae were isolated from diseased tilapia from different areas of Thailand. A total of 124 S. agalactiae isolates were identified by phenotypic analysis and confirmed by 16S rRNA PCR. Bacterial genotyping was conducted based on (i) molecular serotyping of the capsular polysaccharide (cps) gene cluster and (ii) virulence gene profiling using multiplex PCR analysis of 14 virulence genes (lmb, scpB, pavA, cspA, spb1, cyl, bca, rib, fbsA, fbsB, cfb, hylB, bac and pbp1A/ponA). Only serotypes Ia and III were found in this study; serotype Ia lacks the lmb, scpB and spb1 genes, whereas serotype III lacks only the bac gene. Virulence tests in juvenile Nile tilapia demonstrated a correlation between the pathogenicity of the bacteria and their virulence gene profile, with serotype III showing higher virulence than serotype Ia. Epidemiological analysis showed an almost equal distribution in all regions of Thailand, except serotype III was found predominantly in the southern areas. Only two serotypes of S. agalactiae were isolated from diseased tilapia in Thailand. Serotype Ia showed fewer virulence genes and lower virulence than serotype III. Both serotypes showed a similar distribution throughout Thailand. We identified two major serotypes of S. agalactiae isolates associated with the outbreak in

  7. Molecular cloning, characterization and expression analysis of TLR9, MyD88 and TRAF6 genes in common carp (Cyprinus carpio)

    Science.gov (United States)

    Induction of innate immune pathways is critical for early host defense but there is limited understanding of how teleost fish recognize pathogen molecules and activate these pathways. In mammals, cells of the innate immune system detect pathogenic molecular structures using pattern recognition rece...

  8. Effector-mediated suppression of chitin-triggered immunity by Magnaporthe oryzae is necessary for rice blast disease

    NARCIS (Netherlands)

    Mentlak, T.A.; Kombrink, A.; Shinya, T.; Ryder, L.S.; Otomo, I.; Saitoh, H.; Terauchi, R.; Nishizawa, Y.; Shibuya, N.; Thomma, B.P.H.J.; Talbot, N.J.

    2012-01-01

    Plants use pattern recognition receptors to defend themselves from microbial pathogens. These receptors recognize pathogen-associated molecular patterns (PAMPs) and activate signaling pathways that lead to immunity. In rice (Oryza sativa), the chitin elicitor binding protein (CEBiP) recognizes

  9. Pathogenicity Assay of Vibrio harveyi in Tiger Shrimp Larvae Employing Rifampicin-Resistant as A Molecular Marker

    Directory of Open Access Journals (Sweden)

    . Widanarni

    2007-12-01

    Full Text Available Rifampicin-resistant marker was employed as a reporter to assay pathogenicity of Vibrio harveyi  in shrimp larvae.  V. harveyi M. G3 and G7 that difference not schizotyping as shown by Pulsed-Filed Gel Electrophoresis (PFGE used in this study. Spontaneous mutation was conducted to generate V. harveyi resistant to rifampicin. Two groups of shrimp post-larvae (PL5 were immersed for 30 min in 106 CFU/ml of mutants and wild type of V. harveyi, respectively; and then placed in a 2 liter shrimp rearing tank for five days. A control group was immersed in sterile seawater. Growth curve analysis and pathogenicity assay of V. harveyi  showed that each of the V. harveyi mutant exhibited almost identical profiles to that of the wild type parental strain and did not show alteration in their pathogenicity. Sample from dead shrimp larvae showed that the dead shrimp larvae were infected by V. harveyi RfR, indicated that rifampicin-resistant marker effective as a reporter to assay pathogenicity of Vibrio harveyi in shrimp larvae. Key words: shrimp larvae, Vibrio harveyi, rifampicin-resistant, molecular marker

  10. Lipoteichoic Acid (LTA) and Lipopolysaccharides (LPS) from Periodontal Pathogenic Bacteria Facilitate Oncogenic Herpesvirus Infection within Primary Oral Cells

    Science.gov (United States)

    Dai, Lu; DeFee, Michael R.; Cao, Yueyu; Wen, Jiling; Wen, Xiaofei; Noverr, Mairi C.; Qin, Zhiqiang

    2014-01-01

    Kaposi’s sarcoma (KS) remains the most common tumor arising in patients with HIV/AIDS, and involvement of the oral cavity represents one of the most common clinical manifestations of this tumor. HIV infection incurs an increased risk for periodontal diseases and oral carriage of a variety of bacteria. Whether interactions involving pathogenic bacteria and oncogenic viruses in the local environment facilitate replication or maintenance of these viruses in the oral cavity remains unknown. In the current study, our data indicate that pretreatment of primary human oral fibroblasts with two prototypical pathogen-associated molecular patterns (PAMPs) produced by oral pathogenic bacteria–lipoteichoic acid (LTA) and lipopolysaccharide (LPS), increase KSHV entry and subsequent viral latent gene expression during de novo infection. Further experiments demonstrate that the underlying mechanisms induced by LTA and/or LPS include upregulation of cellular receptor, increasing production of reactive oxygen species (ROS), and activating intracellular signaling pathways such as MAPK and NF-κB, and all of which are closely associated with KSHV entry or gene expression within oral cells. Based on these findings, we hope to provide the framework of developing novel targeted approaches for treatment and prevention of oral KSHV infection and KS development in high-risk HIV-positive patients. PMID:24971655

  11. A study of aerobic bacterial pathogens associated with vaginitis in reproductive age group women (15-45 years) and their sensitivity pattern

    OpenAIRE

    Sangeetha K. T.; Saroj Golia; Vasudha C. L.

    2015-01-01

    Background: Aerobic vaginitis (AV) is caused by a displacement of the healthy vaginal Lactobacillus species with aerobic pathogens such as Enterococcus faecalis, Escherichia coli and Staphylococcus aureus that triggers a localized vaginal inflammatory immune response. AV if it is not diagnosed and treated early, especially during pregnancy can place the health of both the mother and the foetus at risk as it is associated with preterm birth, premature rupture of membranes (PROM) and chorioamni...

  12. Molecular phenotypes associated with anomalous stamen development in Alternanthera philoxeroides

    Directory of Open Access Journals (Sweden)

    Zhu eZhu

    2015-04-01

    Full Text Available Alternanthera philoxeroides is a perennial amphibious weed native to South America but has now spread to diverse parts of the world. A. philoxeroides reproduces both sexually and asexually in its native range, but propagates solely through vegetative means in its introduced range. Traits associated with sexual reproduction become degraded for sexual dysfunction, with flowers possessing either pistillate stamens or male-sterile anthers. Degradations of sexual characters for loss of sexuality commonly take place in clonal plants. The underlying molecular-genetic processes remain largely unknown. We compared the gene expression profiles of abnormal stamens with that of normal stamens by RNA-Seq analysis, and identified a large number of differentially expressed genes between abnormal and normal stamens. In accordance with flower morphology, the expression of B-class MADS-box genes (ApAP3, ApTM6 and ApPI was markedly reduced in pistillate stamens. However, most of the genes involved in meiosis were expressed normally in stamens with male-sterile anthers. In addition to verifying the expression patterns of genes previously known to be related to stamen and pollen grain development, we also identified previously unknown molecular phenotypes associated with sexual dysfunction in A. philoxeroides, that is helpful for dissecting the molecular mechanisms underpinning various male-sterile phenotypes and the molecular processes underlying the transition from sexuality to asexuality in clonal plants.

  13. Methanol and ethanol modulate responses to danger- and microbe-associated molecular patterns

    Science.gov (United States)

    Methanol is a byproduct of cell wall modification, released through the action of pectin methylesterases (PMEs), which demethylesterify cell wall pectins. Plant PMEs play not only a role in developmental processes but also in responses to herbivory and infection by fungal or bacterial pathogens. Mol...

  14. Aerobic pathogenic bacteria in post-operative wounds at Moi ...

    African Journals Online (AJOL)

    Background: The emergence of bacterial antimicrobial resistance associated with acquired infections has made the choice of empirical therapy more difficult and expensive, hence the need for continuous research to determine their sensitivity patterns. Objectives: To identify the common aerobic pathogenic bacteria in ...

  15. [Genodiagnosis and molecular typing of the pathogens for plague, cholera, and anthrax].

    Science.gov (United States)

    Kutyrev, V V; Smirnova, N I

    2003-01-01

    The paper contains a survey of published data about the use of DNA-diagnostics in indicating and identifying the causative agents of highly dangerous infections like plague, cholera and anthrax. A discussion of data about the genetic relationship between strains of the mentioned causative agents isolated from different sources by using the molecular-typing methods as well as about the evolution ties between strains of different origins is in the focus of attention. Results of comparative studies of nucleotide sequences of genomes or of individual genomes in different Yersinia pestis, Vibrio cholerae and Bacillus anthracis strains, which are indicative of the evolution of their pathogenicity, are also under discussion.

  16. Manipulation of host membranes by the bacterial pathogens Listeria, Francisella, Shigella and Yersinia.

    Science.gov (United States)

    Pizarro-Cerdá, Javier; Charbit, Alain; Enninga, Jost; Lafont, Frank; Cossart, Pascale

    2016-12-01

    Bacterial pathogens display an impressive arsenal of molecular mechanisms that allow survival in diverse host niches. Subversion of plasma membrane and cytoskeletal functions are common themes associated to infection by both extracellular and intracellular pathogens. Moreover, intracellular pathogens modify the structure/stability of their membrane-bound compartments and escape degradation from phagocytic or autophagic pathways. Here, we review the manipulation of host membranes by Listeria monocytogenes, Francisella tularensis, Shigella flexneri and Yersinia spp. These four bacterial model pathogens exemplify generalized strategies as well as specific features observed during bacterial infection processes. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Transcriptional Dynamics Driving MAMP-Triggered Immunity and Pathogen Effector-Mediated Immunosuppression in Arabidopsis Leaves Following Infection with Pseudomonas syringae pv tomato DC3000.

    Science.gov (United States)

    Lewis, Laura A; Polanski, Krzysztof; de Torres-Zabala, Marta; Jayaraman, Siddharth; Bowden, Laura; Moore, Jonathan; Penfold, Christopher A; Jenkins, Dafyd J; Hill, Claire; Baxter, Laura; Kulasekaran, Satish; Truman, William; Littlejohn, George; Prusinska, Justyna; Mead, Andrew; Steinbrenner, Jens; Hickman, Richard; Rand, David; Wild, David L; Ott, Sascha; Buchanan-Wollaston, Vicky; Smirnoff, Nick; Beynon, Jim; Denby, Katherine; Grant, Murray

    2015-11-01

    Transcriptional reprogramming is integral to effective plant defense. Pathogen effectors act transcriptionally and posttranscriptionally to suppress defense responses. A major challenge to understanding disease and defense responses is discriminating between transcriptional reprogramming associated with microbial-associated molecular pattern (MAMP)-triggered immunity (MTI) and that orchestrated by effectors. A high-resolution time course of genome-wide expression changes following challenge with Pseudomonas syringae pv tomato DC3000 and the nonpathogenic mutant strain DC3000hrpA- allowed us to establish causal links between the activities of pathogen effectors and suppression of MTI and infer with high confidence a range of processes specifically targeted by effectors. Analysis of this information-rich data set with a range of computational tools provided insights into the earliest transcriptional events triggered by effector delivery, regulatory mechanisms recruited, and biological processes targeted. We show that the majority of genes contributing to disease or defense are induced within 6 h postinfection, significantly before pathogen multiplication. Suppression of chloroplast-associated genes is a rapid MAMP-triggered defense response, and suppression of genes involved in chromatin assembly and induction of ubiquitin-related genes coincide with pathogen-induced abscisic acid accumulation. Specific combinations of promoter motifs are engaged in fine-tuning the MTI response and active transcriptional suppression at specific promoter configurations by P. syringae. © 2015 American Society of Plant Biologists. All rights reserved.

  18. Genes, communities & invasive species: understanding the ecological and evolutionary dynamics of host-pathogen interactions.

    Science.gov (United States)

    Burdon, J J; Thrall, P H; Ericson, L

    2013-08-01

    Reciprocal interactions between hosts and pathogens drive ecological, epidemiological and co-evolutionary trajectories, resulting in complex patterns of diversity at population, species and community levels. Recent results confirm the importance of negative frequency-dependent rather than 'arms-race' processes in the evolution of individual host-pathogen associations. At the community level, complex relationships between species abundance and diversity dampen or alter pathogen impacts. Invasive pathogens challenge these controls reflecting the earliest stages of evolutionary associations (akin to arms-race) where disease effects may be so great that they overwhelm the host's and community's ability to respond. Viewing these different stabilization/destabilization phases as a continuum provides a valuable perspective to assessment of the role of genetics and ecology in the dynamics of both natural and invasive host-pathogen associations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Molecular structure determination from x-ray scattering patterns of laser-aligned symmetric-top molecules

    International Nuclear Information System (INIS)

    Ho, P. J.; Starodub, D.; Saldin, D. K.; Shneerson, V. L.; Ourmazd, A.; Santra, R.

    2009-01-01

    We investigate the molecular structure information contained in the x-ray diffraction patterns of an ensemble of rigid CF 3 Br molecules aligned by an intense laser pulse at finite rotational temperature. The diffraction patterns are calculated at an x-ray photon energy of 20 keV to probe molecular structure at angstrom-scale resolution. We find that a structural reconstruction algorithm based on iterative phase retrieval fails to extract a reliable structure. However, the high atomic number of Br compared with C or F allows each diffraction pattern to be treated as a hologram. Using this approach, the azimuthal projection of the molecular electron density about the alignment axis may be retrieved.

  20. Molecular epidemiology of pathogenic Leptospira spp. among large ruminants in the Philippines.

    Science.gov (United States)

    Villanueva, Marvin A; Mingala, Claro N; Balbin, Michelle M; Nakajima, Chie; Isoda, Norikazu; Suzuki, Yasuhiko; Koizumi, Nobuo

    2016-12-01

    The extent of Leptospira infection in large ruminants resulting to economic problems in livestock industry in a leptospirosis-endemic country like the Philippines has not been extensively explored. Therefore, we determined the prevalence and carrier status of leptospirosis in large ruminants using molecular techniques and assessed the risk factors of acquiring leptospirosis in these animals. Water buffalo and cattle urine samples (n=831) collected from 21 farms during 2013-2015 were subjected to flaB-nested PCR to detect pathogenic Leptospira spp. Leptospiral flaB was detected in both species with a detection rate of 16.1%. Leptospiral DNA was detected only in samples from animals managed in communal farms. Sequence analysis of Leptospira flaB in large ruminants revealed the formation of three major clusters with L. borgpetersenii or L. kirschneri. One farm contained Leptospira flaB sequences from all clusters identified in this study, suggesting this farm was the main source of leptospires for other farms. This study suggested that these large ruminants are infected with various pathogenic Leptospira species causing possible major economic loss in the livestock industry as well as potential Leptospira reservoirs that can transmit infection to humans and other animals in the Philippines.

  1. Race-Specific Adult-Plant Resistance in Winter Wheat to Stripe Rust and Characterization of Pathogen Virulence Patterns.

    Science.gov (United States)

    Milus, Eugene A; Moon, David E; Lee, Kevin D; Mason, R Esten

    2015-08-01

    Stripe rust, caused by Puccinia striiformis f. sp. tritici, is an important disease of wheat in the Great Plains and southeastern United States. Growing resistant cultivars is the preferred means for managing stripe rust, but new virulence in the pathogen population overcomes some of the resistance. The objectives of this study were to characterize the stripe rust resistance in contemporary soft and hard red winter wheat cultivars, to characterize the virulence of P. striiformis f. sp. tritici isolates based on the resistances found in the cultivars, and to determine wheat breeders' perceptions on the importance and methods for achieving stripe rust resistance. Seedlings of cultivars were susceptible to recent isolates, indicating they lacked effective all-stage resistance. However, adult-plants were resistant or susceptible depending on the isolate, indicating they had race-specific adult-plant resistance. Using isolates collected from 1990 to 2013, six major virulence patterns were identified on adult plants of twelve cultivars that were selected as adult-plant differentials. Race-specific adult-plant resistance appears to be the only effective type of resistance protecting wheat from stripe rust in eastern United States. Among wheat breeders, the importance of incorporating stripe rust resistance into cultivars ranged from high to low depending on the frequency of epidemics in their region, and most sources of stripe rust resistance were either unknown or already overcome by virulence in the pathogen population. Breeders with a high priority for stripe rust resistance made most of their selections based on adult-plant reactions in the field, whereas breeders with a low priority for resistance based selections on molecular markers for major all-stage resistance genes.

  2. Alternative Pre-mRNA Splicing in Mammals and Teleost Fish: A Effective Strategy for the Regulation of Immune Responses Against Pathogen Infection.

    Science.gov (United States)

    Chang, Ming Xian; Zhang, Jie

    2017-07-15

    Pre-mRNA splicing is the process by which introns are removed and the protein coding elements assembled into mature mRNAs. Alternative pre-mRNA splicing provides an important source of transcriptome and proteome complexity through selectively joining different coding elements to form mRNAs, which encode proteins with similar or distinct functions. In mammals, previous studies have shown the role of alternative splicing in regulating the function of the immune system, especially in the regulation of T-cell activation and function. As lower vertebrates, teleost fish mainly rely on a large family of pattern recognition receptors (PRRs) to recognize pathogen-associated molecular patterns (PAMPs) from various invading pathogens. In this review, we summarize recent advances in our understanding of alternative splicing of piscine PRRs including peptidoglycan recognition proteins (PGRPs), nucleotide binding and oligomerization domain (NOD)-like receptors (NLRs), retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) and their downstream signaling molecules, compared to splicing in mammals. We also discuss what is known and unknown about the function of splicing isoforms in the innate immune responses against pathogens infection in mammals and teleost fish. Finally, we highlight the consequences of alternative splicing in the innate immune system and give our view of important directions for future studies.

  3. A novel Arabidopsis CHITIN ELICITOR RECEPTOR KINASE 1 (CERK1) mutant with enhanced pathogen-induced cell death and altered receptor processing.

    Science.gov (United States)

    Petutschnig, Elena K; Stolze, Marnie; Lipka, Ulrike; Kopischke, Michaela; Horlacher, Juliane; Valerius, Oliver; Rozhon, Wilfried; Gust, Andrea A; Kemmerling, Birgit; Poppenberger, Brigitte; Braus, Gerhard H; Nürnberger, Thorsten; Lipka, Volker

    2014-12-01

    Plants detect pathogens by sensing microbe-associated molecular patterns (MAMPs) through pattern recognition receptors. Pattern recognition receptor complexes also have roles in cell death control, but the underlying mechanisms are poorly understood. Here, we report isolation of cerk1-4, a novel mutant allele of the Arabidopsis chitin receptor CERK1 with enhanced defense responses. We identified cerk1-4 in a forward genetic screen with barley powdery mildew and consequently characterized it by pathogen assays, mutant crosses and analysis of defense pathways. CERK1 and CERK1-4 proteins were analyzed biochemically. The cerk1-4 mutation causes an amino acid exchange in the CERK1 ectodomain. Mutant plants maintain chitin signaling capacity but exhibit hyper-inducible salicylic acid concentrations and deregulated cell death upon pathogen challenge. In contrast to chitin signaling, the cerk1-4 phenotype does not require kinase activity and is conferred by the N-terminal part of the receptor. CERK1 undergoes ectodomain shedding, a well-known process in animal cell surface proteins. Wild-type plants contain the full-length CERK1 receptor protein as well as a soluble form of the CERK1 ectodomain, whereas cerk1-4 plants lack the N-terminal shedding product. Our work suggests that CERK1 may have a chitin-independent role in cell death control and is the first report of ectodomain shedding in plants. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  4. [Development of molecular detection of food-borne pathogenic bacteria using miniaturized microfluidic devices].

    Science.gov (United States)

    Iván, Kristóf; Maráz, Anna

    2015-12-20

    Detection and identification of food-borne pathogenic bacteria are key points for the assurance of microbiological food safety. Traditional culture-based methods are more and more replaced by or supplemented with nucleic acid based molecular techniques, targeting specific (preferably virulence) genes in the genomes. Internationally validated DNA amplification - most frequently real-time polymerase chain reaction - methods are applied by the food microbiological testing laboratories for routine analysis, which will result not only in shortening the time for results but they also improve the performance characteristics (e.g. sensitivity, specificity) of the methods. Beside numerous advantages of the polymerase chain reaction based techniques for routine microbiological analysis certain drawbacks have to be mentioned, such as the high cost of the equipment and reagents, as well as the risk of contamination of the laboratory environment by the polymerase chain reaction amplicons, which require construction of an isolated laboratory system. Lab-on-a-chip systems can integrate most of these laboratory processes within a miniaturized device that delivers the same specificity and reliability as the standard protocols. The benefits of miniaturized devices are: simple - often automated - use, small overall size, portability, sterility due to single use possibility. These miniaturized rapid diagnostic tests are being researched and developed at the best research centers around the globe implementing various sample preparation and molecular DNA amplification methods on-chip. In parallel, the aim of the authors' research is to develop microfluidic Lab-on-a-chip devices for the detection and identification of food-borne pathogenic bacteria.

  5. The tomato UV-damaged DNA-binding protein-1 (DDB1) is implicated in pathogenesis-related (PR) gene expression and resistance to Agrobacterium tumefaciens

    Science.gov (United States)

    Plants defend themselves against potential pathogens via the recognition of pathogen-associated molecular patterns (PAMPs). However, the molecular mechanisms underlying this PAMP triggered immunity (PTI) are largely unknown. In this study, we show that tomato HP1/DDB1, coding for a key component of ...

  6. Ficolins and FIBCD1: Soluble and membrane bound pattern recognition molecules with acetyl group selectivity

    DEFF Research Database (Denmark)

    Thomsen, Theresa; Schlosser, Anders; Holmskov, Uffe

    2011-01-01

    as pattern recognition molecules. Ficolins are soluble oligomeric proteins composed of trimeric collagen-like regions linked to fibrinogen-related domains (FReDs) that have the ability to sense molecular patterns on both pathogens and apoptotic cell surfaces and activate the complement system. The ficolins......D-containing molecules, and discusses structural resemblance but also diversity in recognition of acetylated ligands....

  7. Human gestation-associated tissues express functional cytosolic nucleic acid sensing pattern recognition receptors.

    Science.gov (United States)

    Bryant, A H; Menzies, G E; Scott, L M; Spencer-Harty, S; Davies, L B; Smith, R A; Jones, R H; Thornton, C A

    2017-07-01

    The role of viral infections in adverse pregnancy outcomes has gained interest in recent years. Innate immune pattern recognition receptors (PRRs) and their signalling pathways, that yield a cytokine output in response to pathogenic stimuli, have been postulated to link infection at the maternal-fetal interface and adverse pregnancy outcomes. The objective of this study was to investigate the expression and functional response of nucleic acid ligand responsive Toll-like receptors (TLR-3, -7, -8 and -9), and retinoic acid-inducible gene 1 (RIG-I)-like receptors [RIG-I, melanoma differentiation-associated protein 5 (MDA5) and Laboratory of Genetics and Physiology 2(LGP2)] in human term gestation-associated tissues (placenta, choriodecidua and amnion) using an explant model. Immunohistochemistry revealed that these PRRs were expressed by the term placenta, choriodecidua and amnion. A statistically significant increase in interleukin (IL)-6 and/or IL-8 production in response to specific agonists for TLR-3 (Poly(I:C); low and high molecular weight), TLR-7 (imiquimod), TLR-8 (ssRNA40) and RIG-I/MDA5 (Poly(I:C)LyoVec) was observed; there was no response to a TLR-9 (ODN21798) agonist. A hierarchical clustering approach was used to compare the response of each tissue type to the ligands studied and revealed that the placenta and choriodecidua generate a more similar IL-8 response, while the choriodecidua and amnion generate a more similar IL-6 response to nucleic acid ligands. These findings demonstrate that responsiveness via TLR-3, TLR-7, TLR-8 and RIG-1/MDA5 is a broad feature of human term gestation-associated tissues with differential responses by tissue that might underpin adverse obstetric outcomes. © 2017 British Society for Immunology.

  8. B cells promote obesity-associated periodontitis and oral pathogen-associated inflammation.

    Science.gov (United States)

    Zhu, Min; Belkina, Anna C; DeFuria, Jason; Carr, Jordan D; Van Dyke, Thomas E; Gyurko, Robert; Nikolajczyk, Barbara S

    2014-08-01

    Individuals with T2D and PD suffer significantly from the ability of one disease to intensify the other. Disease-associated inflammation is one mechanism thought to fuel this pathogenic feed-forward loop. Several lines of evidence indicate that proinflammatory B cells promote T2D and PD; thus, B cells are top candidates for a cell type that predisposes PD in T2D. To test directly the role of B cells in T2D-associated PD, we compared outcomes from oral Porphyromonas gingivalis challenge of lean WT or B cell-null mice with outcomes from mice that were obese and insulin-resistant before challenge. Obese WT mice responded to oral P. gingivalis challenge with significant periodontal bone loss, whereas obese B cell-null mice were protected completely from PD. By contrast, lean WT and B cell-null mice suffer similar periodontal bone loss in response to oral pathogen. B cells from obese/insulin-resistant hosts also support oral osteoclastogenesis and both oral and systemic production of inflammatory cytokines, including pro-osteoclastogenic TNF-α and MIP-2, an ortholog of human IL-8. B cells furthermore impact AT inflammation in obese, P. gingivalis-infected hosts. Taken together, these data show that fundamentally different mechanisms regulate PD in lean and obese hosts, with B cells able to promote PD only if the hosts are "primed" by obesity. These results justify more intense analysis of obesity-associated changes in B cells that predispose PD in human T2D. © 2014 Society for Leukocyte Biology.

  9. Priming of the Arabidopsis pattern-triggered immunity response upon infection by necrotrophic Pectobacterium carotovorum bacteria.

    Science.gov (United States)

    Po-Wen, Chen; Singh, Prashant; Zimmerli, Laurent

    2013-01-01

    Boosted responsiveness of plant cells to stress at the onset of pathogen- or chemically induced resistance is called priming. The chemical β-aminobutyric acid (BABA) enhances Arabidopsis thaliana resistance to hemibiotrophic bacteria through the priming of the salicylic acid (SA) defence response. Whether BABA increases Arabidopsis resistance to the necrotrophic bacterium Pectobacterium carotovorum ssp. carotovorum (Pcc) is not clear. In this work, we show that treatment with BABA protects Arabidopsis against the soft-rot pathogen Pcc. BABA did not prime the expression of the jasmonate/ethylene-responsive gene PLANT DEFENSIN 1.2 (PDF1.2), the up-regulation of which is usually associated with resistance to necrotrophic pathogens. Expression of the SA marker gene PATHOGENESIS RELATED 1 (PR1) on Pcc infection was primed by BABA treatment, but SA-defective mutants demonstrated a wild-type level of BABA-induced resistance against Pcc. BABA primed the expression of the pattern-triggered immunity (PTI)-responsive genes FLG22-INDUCED RECEPTOR-LIKE KINASE 1 (FRK1), ARABIDOPSIS NON-RACE SPECIFIC DISEASE RESISTANCE GENE (NDR1)/HAIRPIN-INDUCED GENE (HIN1)-LIKE 10 (NHL10) and CYTOCHROME P450, FAMILY 81 (CYP81F2) after inoculation with Pcc or after treatment with purified bacterial microbe-associated molecular patterns, such as flg22 or elf26. PTI-mediated callose deposition was also potentiated in BABA-treated Arabidopsis, and BABA boosted Arabidopsis stomatal immunity to Pcc. BABA treatment primed the PTI response in the SA-defective mutants SA induction deficient 2-1 (sid2-1) and phytoalexin deficient 4-1 (pad4-1). In addition, BABA priming was associated with open chromatin configurations in the promoter region of PTI marker genes. Our data indicate that BABA primes the PTI response upon necrotrophic bacterial infection and suggest a role for the PTI response in BABA-induced resistance. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  10. Self-organized patterns of macroscopic quantum tunneling in molecular magnets.

    Science.gov (United States)

    Garanin, D A; Chudnovsky, E M

    2009-03-06

    We study low temperature resonant spin tunneling in molecular magnets induced by a field sweep with account of dipole-dipole interactions. Numerical simulations uncovered formation of self-organized patterns of the magnetization and of the ensuing dipolar field that provide resonant conditions inside a finite volume of the crystal. This effect is robust with respect to disorder and should be relevant to the dynamics of the magnetization steps observed in molecular magnets.

  11. Detection of virulence factors and molecular typing of pathogenic Leptospira from capybara (Hydrochaeris hydrochaeris).

    Science.gov (United States)

    Jorge, Sérgio; Monte, Leonardo G; Coimbra, Marco Antonio; Albano, Ana Paula; Hartwig, Daiane D; Lucas, Caroline; Seixas, Fabiana K; Dellagostin, Odir A; Hartleben, Cláudia P

    2012-10-01

    Leptospirosis is a globally prevalent zoonosis caused by pathogenic Leptospira spp.; several serologic variants have reservoirs in synanthropic rodents. The capybara is the largest living rodent in the world, and it has a wide geographical distribution in Central and South America. This rodent is a significant source of Leptospira since the agent is shed via urine into the environment and is a potential public health threat. In this study, we isolated and identified by molecular techniques a pathogenic Leptospira from capybara in southern Brazil. The isolated strain was characterized by partial rpoB gene sequencing and variable-number tandem-repeats analysis as L. interrogans, serogroup Icterohaemorrhagiae. In addition, to confirm the expression of virulence factors, the bacterial immunoglobulin-like proteins A and B expression was detected by indirect immunofluorescence using leptospiral specific monoclonal antibodies. This report identifies capybaras as an important source of infection and provides insight into the epidemiology of leptospirosis.

  12. Frequency and antibiotic susceptibility patterns of urinary pathogens in male outpatients in Argentina.

    Science.gov (United States)

    Villar, Hugo E; Jugo, Mónica B; Macan, Alejandro; Visser, Matias; Hidalgo, Mariana; Maccallini, Gustavo Cesar

    2014-06-11

    Knowledge of the etiology and antimicrobial susceptibility patterns of uropathogens is important for determining the best treatment option. This study aimed to determine the distribution and antibiotic susceptibility patterns of bacterial strains isolated from adult male outpatients. Between November 2012 and April 2013, 3,105 community urine samples were analyzed from adult male patients who attended the Laboratorio Hidalgo, Buenos Aires, Argentina. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disc diffusion method. Isolates resistant to third generation cephalosporin were tested for extended-spectrum beta-lactamase (ESBL) production using the double-disk synergy test. Of the 3,105 urine samples analyzed, 791 (25.5%) had significant bacteriuria. The frequency of positive urine cultures increased significantly with patient age. Escherichia coli was isolated most frequently (47.3%), followed by Enterococcus faecalis (13.6%), and Klebsiella pneumoniae (11.9%). Gram-negative organisms represented 78.8% of urinary pathogens. The highest activities against Gram-negative bacteria were found with imipenem (99.0%), amikacin (98.1%), ertapenem (94.2%), fosfomycin (90.7%), and piperacillin-tazobactam (90.1%). The frequencies of ESBLs among E. coli, K. pneumoniae, and P. mirabilis were 15.2 %, 22.3%, and 8%, respectively. Fosfomycin, piperacillin-tazobactam, and nitrofurantoin were most effective against Gram-positive organisms. Fosfomycin may be an excellent option for cystitis treatment in patients without risk factors, whereas piperacillin-tazobactam is preferred for the treatment of parenchymatous UTIs, complicated UTIs, and UTIs associated with risk factors. To ensure the optimal selection of antibiotics, physicians should have access to up-to-date information about the local prevalence of antimicrobial resistance.

  13. Approaches to understanding the impact of life-history features on plant-pathogen co-evolutionary dynamics

    Science.gov (United States)

    Jeremy J. Burdon; Peter H. Thrall; Adnane Nemri

    2012-01-01

    Natural plant-pathogen associations are complex interactions in which the interplay of environment, host, and pathogen factors results in spatially heterogeneous ecological and epidemiological dynamics. The evolutionary patterns that result from the interaction of these factors are still relatively poorly understood. Recently, integration of the appropriate spatial and...

  14. Association between pathogens from tracheal aspirate and oral biofilm of patients on mechanical ventilation

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    Luana Carneiro Diniz SOUZA

    2017-06-01

    Full Text Available Abstract The aim of this study was to detect possible associations between respiratory pathogens from tracheal aspirate and oral biofilm samples in intubated patients in an intensive care unit (ICU, and to identify the most common respiratory pathogens in oral biofilm, particularly in patients that developed ventilator-associated pneumonia (VAP. Two oral biofilm samples were collected from the tongue of intubated patients (at admission and after 48 hours and analyzed by culture with the Antibiotic Sensitivity Test. The results from the tongue biofilm samples were compared with the tracheal secretions samples. A total of 59.37% of patients exhibited the same species of pathogens in their tracheal aspirate and oral biofilm, of which 8 (42.1% developed VAP, 10 (52.63% did not develop pneumonia and one (5.26% had aspiration pneumonia. There was a statistically significant association between presence of microorganisms in the tracheal and mouth samples for the following pathogens: Klebsiella pneumoniae, Candida albicans, Pseudomonas aeruginosa, Enterobacter gergoviae, Streptococcus spp and Serratia marcescens (p < 0.05. Pathogens that are present in tracheal aspirates of intubated patients can be detected in their oral cavity, especially in those who developed VAP or aspiration pneumonia. Thus, the results indicate that an improved oral care in these patients could decrease ICU pneumonia rates.

  15. Molecular design of Mycoplasma hominis Vaa adhesin

    DEFF Research Database (Denmark)

    Boesen, Thomas; Fedosova, Natalya U.; Kjeldgaard, Morten

    2001-01-01

    The variable adherence-associated (Vaa) adhesin of the opportunistic human pathogen Mycoplasma hominis is a surface-exposed, membrane-associated protein involved in the attachment of the bacterium to host cells. The molecular masses of recombinant 1 and 2 cassette forms of the protein determined...

  16. Population structure and migration pattern of a conifer pathogen, Grosmannia clavigera, as influenced by its symbiont, the mountain pine beetle.

    Science.gov (United States)

    Tsui, Clement K M; Roe, Amanda D; El-Kassaby, Yousry A; Rice, Adrianne V; Alamouti, Sepideh M; Sperling, Felix A H; Cooke, Janice E K; Bohlmann, Jörg; Hamelin, Richard C

    2012-01-01

    We investigated the population structure of Grosmannia clavigera (Gc), a fungal symbiont of the mountain pine beetle (MPB) that plays a crucial role in the establishment and reproductive success of this pathogen. This insect-fungal complex has destroyed over 16 million ha of lodgepole pine forests in Canada, the largest MPB epidemic in recorded history. During this current epidemic, MPB has expanded its range beyond historically recorded boundaries, both northward and eastward, and has now reached the jack pine of Alberta, potentially threatening the Canadian boreal forest. To better understand the dynamics between the beetle and its fungal symbiont, we sampled 19 populations in western North America and genotyped individuals from these populations with eight microsatellite markers. The fungus displayed high haplotype diversity, with over 250 unique haplotypes observed in 335 single spore isolates. Linkage equilibria in 13 of the 19 populations suggested that the fungus reproduces sexually. Bayesian clustering and distance analyses identified four genetic clusters that corresponded to four major geographical regions, which suggested that the epidemic arose from multiple geographical sources. A genetic cluster north of the Rocky Mountains, where the MPB has recently become established, experienced a population bottleneck, probably as a result of the recent range expansion. The two genetic clusters located north and west of the Rocky Mountains contained many fungal isolates admixed from all populations, possibly due to the massive movement of MPB during the epidemic. The general agreement in north-south differentiation of MPB and G. clavigera populations points to the fungal pathogen's dependence on the movement of its insect vector. In addition, the patterns of diversity and the individual assignment tests of the fungal associate suggest that migration across the Rocky Mountains occurred via a northeastern corridor, in accordance with meteorological patterns and

  17. Autophagy in plant pathogenic fungi.

    Science.gov (United States)

    Liu, Xiao-Hong; Xu, Fei; Snyder, John Hugh; Shi, Huan-Bin; Lu, Jian-Ping; Lin, Fu-Cheng

    2016-09-01

    Autophagy is a conserved cellular process that degrades cytoplasmic constituents in vacuoles. Plant pathogenic fungi develop special infection structures and/or secrete a range of enzymes to invade their plant hosts. It has been demonstrated that monitoring autophagy processes can be extremely useful in visualizing the sequence of events leading to pathogenicity of plant pathogenic fungi. In this review, we introduce the molecular mechanisms involved in autophagy. In addition, we explore the relationship between autophagy and pathogenicity in plant pathogenic fungi. Finally, we discuss the various experimental strategies available for use in the study of autophagy in plant pathogenic fungi. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Molecular pathogenesis of H5 highly pathogenic avian influenza: the role of the haemagglutinin cleavage site motif

    Science.gov (United States)

    Luczo, Jasmina M.; Stambas, John; Durr, Peter A.; Michalski, Wojtek P.

    2015-01-01

    Summary The emergence of H5N1 highly pathogenic avian influenza has caused a heavy socio‐economic burden through culling of poultry to minimise human and livestock infection. Although human infections with H5N1 have to date been limited, concerns for the pandemic potential of this zoonotic virus have been greatly intensified following experimental evidence of aerosol transmission of H5N1 viruses in a mammalian infection model. In this review, we discuss the dominance of the haemagglutinin cleavage site motif as a pathogenicity determinant, the host‐pathogen molecular interactions driving cleavage activation, reverse genetics manipulations and identification of residues key to haemagglutinin cleavage site functionality and the mechanisms of cell and tissue damage during H5N1 infection. We specifically focus on the disease in chickens, as it is in this species that high pathogenicity frequently evolves and from which transmission to the human population occurs. With >75% of emerging infectious diseases being of zoonotic origin, it is necessary to understand pathogenesis in the primary host to explain spillover events into the human population. © 2015 The Authors. Reviews in Medical Virology published by John Wiley & Sons Ltd. PMID:26467906

  19. The host-encoded Heme Regulated Inhibitor (HRI facilitates virulence-associated activities of bacterial pathogens.

    Directory of Open Access Journals (Sweden)

    Niraj Shrestha

    Full Text Available Here we show that cells lacking the heme-regulated inhibitor (HRI are highly resistant to infection by bacterial pathogens. By examining the infection process in wild-type and HRI null cells, we found that HRI is required for pathogens to execute their virulence-associated cellular activities. Specifically, unlike wild-type cells, HRI null cells infected with the gram-negative bacterial pathogen Yersinia are essentially impervious to the cytoskeleton-damaging effects of the Yop virulence factors. This effect is due to reduced functioning of the Yersinia type 3 secretion (T3S system which injects virulence factors directly into the host cell cytosol. Reduced T3S activity is also observed in HRI null cells infected with the bacterial pathogen Chlamydia which results in a dramatic reduction in its intracellular proliferation. We go on to show that a HRI-mediated process plays a central role in the cellular infection cycle of the Gram-positive pathogen Listeria. For this pathogen, HRI is required for the post-invasion trafficking of the bacterium to the infected host cytosol. Thus by depriving Listeria of its intracellular niche, there is a highly reduced proliferation of Listeria in HRI null cells. We provide evidence that these infection-associated functions of HRI (an eIF2α kinase are independent of its activity as a regulator of protein synthesis. This is the first report of a host factor whose absence interferes with the function of T3S secretion and cytosolic access by pathogens and makes HRI an excellent target for inhibitors due to its broad virulence-associated activities.

  20. Molecular mimicry modulates plant host responses to pathogens.

    Science.gov (United States)

    Ronald, Pamela; Joe, Anna

    2018-01-25

    Pathogens often secrete molecules that mimic those present in the plant host. Recent studies indicate that some of these molecules mimic plant hormones required for development and immunity. This Viewpoint reviews the literature on microbial molecules produced by plant pathogens that functionally mimic molecules present in the plant host. This article includes examples from nematodes, bacteria and fungi with emphasis on RaxX, a microbial protein produced by the bacterial pathogen Xanthomonas oryzae pv. oryzae. RaxX mimics a plant peptide hormone, PSY (plant peptide containing sulphated tyrosine). The rice immune receptor XA21 detects sulphated RaxX but not the endogenous peptide PSY. Studies of the RaxX/XA21 system have provided insight into both host and pathogen biology and offered a framework for future work directed at understanding how XA21 and the PSY receptor(s) can be differentially activated by RaxX and endogenous PSY peptides. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Transcriptomic insight into pathogenicity-associated factors of Conidiobolus obscurus, an obligate aphid-pathogenic fungus belonging to Entomopthoromycota.

    Science.gov (United States)

    Wang, Jianghong; Zhou, Xiang; Guo, Kai; Zhang, Xinqi; Lin, Haiping; Montalva, Cristian

    2018-01-16

    Conidiobolus obscurus is a widespread fungal entomopathogen with aphid biocontrol potential. This study focused on a de novo transcriptomic analysis of C. obscurus. A number of pathogenicity-associated factors were annotated for the first time from the assembled 17 231 fungal unigenes, including those encoding subtilisin-like proteolytic enzymes (Pr1s), trypsin-like proteases, metalloproteases, carboxypeptidases and endochitinases. Many of these genes were transcriptionally up-regulated by at least twofold in mycotized cadavers compared with the in vitro fungal cultures. The resultant transcriptomic database was validated by the transcript levels of three selected pathogenicity-related genes quantified from different in vivo and in vitro material in real-time quantitative polymerase chain reaction (PCR). The involvement of multiple Pr1 proteases in the first stage of fungal infection was also suggested. Interestingly, a unique cytolytic (Cyt)-like δ-endotoxin gene was highly expressed in both mycotized cadavers and fungal cultures, and was more or less distinct from its homologues in bacteria and other fungi. Our findings provide the first global insight into various pathogenicity-related genes in this obligate aphid pathogen and may help to develop novel biocontrol strategy against aphid pests. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  2. Subtypes of the Type II Pit Pattern Reflect Distinct Molecular Subclasses in the Serrated Neoplastic Pathway.

    Science.gov (United States)

    Aoki, Hironori; Yamamoto, Eiichiro; Yamano, Hiro-O; Sugai, Tamotsu; Kimura, Tomoaki; Tanaka, Yoshihito; Matsushita, Hiro-O; Yoshikawa, Kenjiro; Takagi, Ryo; Harada, Eiji; Nakaoka, Michiko; Yoshida, Yuko; Harada, Taku; Sudo, Gota; Eizuka, Makoto; Yorozu, Akira; Kitajima, Hiroshi; Niinuma, Takeshi; Kai, Masahiro; Nojima, Masanori; Suzuki, Hiromu; Nakase, Hiroshi

    2018-03-15

    Colorectal serrated lesions (SLs) are important premalignant lesions whose clinical and biological features are not fully understood. We aimed to establish accurate colonoscopic diagnosis and treatment of SLs through evaluation of associations among the morphological, pathological, and molecular characteristics of SLs. A total of 388 premalignant and 18 malignant colorectal lesions were studied. Using magnifying colonoscopy, microsurface structures were assessed based on Kudo's pit pattern classification system, and the Type II pit pattern was subcategorized into classical Type II, Type II-Open (Type II-O) and Type II-Long (Type II-L). BRAF/KRAS mutations and DNA methylation of CpG island methylator phenotype (CIMP) markers (MINT1, - 2, - 12, - 31, p16, and MLH1) were analyzed through pyrosequencing. Type II-O was tightly associated with sessile serrated adenoma/polyps (SSA/Ps) with BRAF mutation and CIMP-high. Most lesions with simple Type II or Type II-L were hyperplastic polyps, while mixtures of Type II or Type II-L plus more advanced pit patterns (III/IV) were characteristic of traditional serrated adenomas (TSAs). Type II-positive TSAs frequently exhibited BRAF mutation and CIMP-low, while Type II-L-positive TSAs were tightly associated with KRAS mutation and CIMP-low. Analysis of lesions containing both premalignant and cancerous components suggested Type II-L-positive TSAs may develop into KRAS-mutated/CIMP-low/microsatellite stable cancers, while Type II-O-positive SSA/Ps develop into BRAF-mutated/CIMP-high/microsatellite unstable cancers. These results suggest that Type II subtypes reflect distinct molecular subclasses in the serrated neoplasia pathway and that they could be useful hallmarks for identifying SLs at high risk of developing into CRC.

  3. The Role of Damage-Associated Molecular Patterns (DAMPs in Human Diseases; Part II: DAMPs as diagnostics, prognostics and therapeutics in clinical medicine

    Directory of Open Access Journals (Sweden)

    Walter G. Land

    2015-05-01

    Full Text Available This article is the second part of a review that addresses the role of damage-associated molecular patterns (DAMPs in human diseases by presenting examples of traumatic (systemic inflammatory response syndrome, cardiovascular (myocardial infarction, metabolic (type 2 diabetes mellitus, neurodegenerative (Alzheimer’s disease, malignant and infectious diseases. Various DAMPs are involved in the pathogenesis of all these diseases as they activate innate immune machineries including the unfolded protein response and inflammasomes. These subsequently promote sterile autoinflammation accompanied, at least in part, by subsequent adaptive autoimmune processes. This review article discusses the future role of DAMPs in routine practical medicine by highlighting the possibility of harnessing and deploying DAMPs either as biomarkers for the appropriate diagnosis and prognosis of diseases, as therapeutics in the treatment of tumours or as vaccine adjuncts for the prophylaxis of infections. In addition, this article examines the potential for developing strategies aimed at mitigating DAMPs-mediated hyperinflammatory responses, such as those seen in systemic inflammatory response syndrome associated with multiple organ failure.

  4. Pathogenicity and molecular analysis of an infectious bursal disease virus isolated from Malaysian village chickens.

    Science.gov (United States)

    Tan, D Y; Hair-Bejo, M; Omar, A R; Aini, I

    2004-01-01

    The characteristics of the pathogenic infectious bursal disease virus (IBDV) that infected avian species other than commercial chickens were largely unknown. In this study, by using in vivo and molecular methods, we had characterized an IBDV isolate (named 94268) isolated from an infectious bursal disease (IBD) outbreak in Malaysian village chickens--the adulterated descendant of the Southeast Asian jungle fowl (Gallus bankiva) that were commonly reared in the backyard. The 94268 isolate was grouped as the very virulent IBDV (vvIBDV) strain because it caused severe lesions and a high mortality rate in village chickens (>88%) and experimentally infected specific-pathogen-free chickens (>66%). In addition, it possessed all of the vvIBDV molecular markers in its VP2 gene. Phylogenetic analysis using distance, maximum parsimony, and maximum likelihood methods revealed that 94268 was monophyletic with other vvIBDV isolates and closely related to the Malaysian vvIBDV isolates. Given that the VP2 gene of 94268 isolate was almost identical and evolutionarily closely related to other field IBDV isolates that affected the commercial chickens, we therefore concluded that IBD infections had spread across the farm boundary. IBD infection in the village chicken may represent an important part of the IBD epidemiology because these birds could harbor the vvIBDV strain and should not be overlooked in the control and prevention of the disease.

  5. The common enteric bacterial pathogens and their antimicrobial susceptibility pattern among HIV-infected individuals attending the antiretroviral therapy clinic of Hawassa university hospital, southern Ethiopia

    Directory of Open Access Journals (Sweden)

    Ayele Kebede

    2017-12-01

    Full Text Available Abstract Background The frequent occurrence of bacterial gastroenteritis among HIV-infected individuals together with increased antimicrobial drug resistance pose a significant public health challenge in developing countries. This study aimed to determine the prevalence of enteric bacterial pathogens and their antimicrobial susceptibility pattern among HIV-infected patients in a tertiary hospital in southern Ethiopia. Methods A hospital-based cross-sectional study was conducted at Hawassa University Comprehensive Specialized Hospital from February to May, 2016. A consecutive 215 HIV-infected patients, with complaints of gastrointestinal tract disease, were enrolled. Data on socio-demography and related factors was collected using a structured questionnaire. A stool sample was collected from each study participant and cultured to isolate enteric bacterial pathogens; isolates were characterized using biochemical tests. Antimicrobial susceptibility was determined using the Kirby- Bauer disk diffusion technique. Results Out of 215 patients, 27(12.6% were culture positive for various bacterial pathogens. Campylobacter species was the most common bacterial isolate (6.04%, followed by Salmonella species (5.1%. The majority of isolates was sensitive to norfloxacin, nalidixic acid, gentamicin, ceftriaxone and ciprofloxacin and showed resistance to trimethoprim sulfamethoxazole (SXT and chloramphenicol. Consumption of raw food was the only risk factor found to be significantly associated with enteric bacterial infection (crude odds ratio 3.41 95% CI 1.13–10.3. Conclusions The observed rate of enteric bacterial pathogens and their antimicrobial resistance pattern to the commonly prescribed antibiotics highlights the need to strengthen intervention efforts and promote rational use of antimicrobials. In this regard, the need to strengthen antimicrobial stewardship efforts should be emphasized to slow grown antimicrobial resistance among this population

  6. [Ultrastructure and molecular biochemistry on pathogenic fungal cells: the architecture of septal cell walls of dermatophytes].

    Science.gov (United States)

    Kitajima, Y

    2001-01-01

    This review provides abstracts of our research for which the year 2000 prize of The Japanese Society for Medical Mycology was awarded. The study consists of 4 fields: 1)Ultrastructure and biochemistry of the cell walls of dermatophytes. 2) Freeze-fracture electron microscopic study on the membrane systems of pathogenic fungi. 3) Action mechanisms of antifungal agents in terms of membrane structure and functions. 4) Dimorphism and virulence of pathogenic fungi in terms of molecular biology of membrane lipids. Since the detailed contents of these studies were reported in my previous review article (Jpn J Med Mycol 41: 211-217, 2000), I would like to mention these studies only briefly here, together with a detailed review of the septal cell wall architecture of dermatophytes, which I did not cover in my earlier articles.

  7. Library of molecular associations: curating the complex molecular basis of liver diseases

    Directory of Open Access Journals (Sweden)

    Maass Thorsten

    2010-03-01

    Full Text Available Abstract Background Systems biology approaches offer novel insights into the development of chronic liver diseases. Current genomic databases supporting systems biology analyses are mostly based on microarray data. Although these data often cover genome wide expression, the validity of single microarray experiments remains questionable. However, for systems biology approaches addressing the interactions of molecular networks comprehensive but also highly validated data are necessary. Results We have therefore generated the first comprehensive database for published molecular associations in human liver diseases. It is based on PubMed published abstracts and aimed to close the gap between genome wide coverage of low validity from microarray data and individual highly validated data from PubMed. After an initial text mining process, the extracted abstracts were all manually validated to confirm content and potential genetic associations and may therefore be highly trusted. All data were stored in a publicly available database, Library of Molecular Associations http://www.medicalgenomics.org/databases/loma/news, currently holding approximately 1260 confirmed molecular associations for chronic liver diseases such as HCC, CCC, liver fibrosis, NASH/fatty liver disease, AIH, PBC, and PSC. We furthermore transformed these data into a powerful resource for molecular liver research by connecting them to multiple biomedical information resources. Conclusion Together, this database is the first available database providing a comprehensive view and analysis options for published molecular associations on multiple liver diseases.

  8. Differential trends in the codon usage patterns in HIV-1 genes.

    Directory of Open Access Journals (Sweden)

    Aridaman Pandit

    Full Text Available Host-pathogen interactions underlie one of the most complex evolutionary phenomena resulting in continual adaptive genetic changes, where pathogens exploit the host's molecular resources for growth and survival, while hosts try to eliminate the pathogen. Deciphering the molecular basis of host-pathogen interactions is useful in understanding the factors governing pathogen evolution and disease propagation. In host-pathogen context, a balance between mutation, selection, and genetic drift is known to maintain codon bias in both organisms. Studies revealing determinants of the bias and its dynamics are central to the understanding of host-pathogen evolution. We considered the Human Immunodeficiency Virus (HIV type 1 and its human host to search for evolutionary signatures in the viral genome. Positive selection is known to dominate intra-host evolution of HIV-1, whereas high genetic variability underlies the belief that neutral processes drive inter-host differences. In this study, we analyze the codon usage patterns of HIV-1 genomes across all subtypes and clades sequenced over a period of 23 years. We show presence of unique temporal correlations in the codon bias of three HIV-1 genes illustrating differential adaptation of the HIV-1 genes towards the host preferred codons. Our results point towards gene-specific translational selection to be an important force driving the evolution of HIV-1 at the population level.

  9. Yeast cell wall extract induces disease resistance against bacterial and fungal pathogens in Arabidopsis thaliana and Brassica crop.

    Directory of Open Access Journals (Sweden)

    Mari Narusaka

    Full Text Available Housaku Monogatari (HM is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods.

  10. Changes in Diversification Patterns and Signatures of Selection during the Evolution of Murinae-Associated Hantaviruses

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    Guillaume Castel

    2014-03-01

    Full Text Available In the last 50 years, hantaviruses have significantly affected public health worldwide, but the exact extent of the distribution of hantavirus diseases, species and lineages and the risk of their emergence into new geographic areas are still poorly known. In particular, the determinants of molecular evolution of hantaviruses circulating in different geographical areas or different host species are poorly documented. Yet, this understanding is essential for the establishment of more accurate scenarios of hantavirus emergence under different climatic and environmental constraints. In this study, we focused on Murinae-associated hantaviruses (mainly Seoul Dobrava and Hantaan virus using sequences available in GenBank and conducted several complementary phylogenetic inferences. We sought for signatures of selection and changes in patterns and rates of diversification in order to characterize hantaviruses’ molecular evolution at different geographical scales (global and local. We then investigated whether these events were localized in particular geographic areas. Our phylogenetic analyses supported the assumption that RNA virus molecular variations were under strong evolutionary constraints and revealed changes in patterns of diversification during the evolutionary history of hantaviruses. These analyses provide new knowledge on the molecular evolution of hantaviruses at different scales of time and space.

  11. Nosocomial pathogens associated with the mobile phones of healthcare workers in a hospital in Anyigba, Kogi state, Nigeria.

    Science.gov (United States)

    Nwankwo, E O; Ekwunife, N; Mofolorunsho, K C

    2014-06-01

    Mobile phones of healthcare workers (HCWs) could be colonized by potential bacteria pathogens. The aim of this research is to evaluate the bacterial contamination and antibiotic sensitivity pattern of isolates from mobile phones of HCWs in Grimad hospital. A total of 112 swab samples were collected from the mobile phones of HCWs and students in June 2012 in Anyigba. While 56 samples were from HCWs in Grimad hospital, 56 samples were obtained from non-healthcare workers (NHCWs) who served as the control. The samples were all screened for bacterial pathogens by standard bacteriological procedures. Antibiotic susceptibility testing was done by the disc diffusion technique. The rate of bacterial contamination of mobile phones of HCWs was 94.6%. Bacteria isolated from mobile phones of HCWs were more resistant to antibiotics than NHCWs phones. Staphylococcus Epidermidis (42.9%) was the most frequently isolated bacteria followed by Bacillus spp. (32.1%), Staphylococcus Aureus (25%), Pseudomonas Aeruginosa (19.6%), Escherichia Coli (14.3%), Streptococcus spp. (14.3%), Proteus spp. (12.5%), Klebsiella spp. (7.1%), and Acinetobacter spp. (5.3%). Cotrimoxazole, ampicillin and tetracycline showed high levels of resistance while gentamicin, ciprofloxacin and ceftriaxone exhibited encouraging results. The presence of bacteria pathogens associated with nosocomial infection was identified. Transmission of pathogens can be reduced by hand hygiene and regular cleaning of mobile phones. Copyright © 2013 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

  12. Molecular design for recombinant adeno-associated virus (rAAV) vector production.

    Science.gov (United States)

    Aponte-Ubillus, Juan Jose; Barajas, Daniel; Peltier, Joseph; Bardliving, Cameron; Shamlou, Parviz; Gold, Daniel

    2018-02-01

    Recombinant adeno-associated virus (rAAV) vectors are increasingly popular tools for gene therapy applications. Their non-pathogenic status, low inflammatory potential, availability of viral serotypes with different tissue tropisms, and prospective long-lasting gene expression are important attributes that make rAAVs safe and efficient therapeutic options. Over the last three decades, several groups have engineered recombinant AAV-producing platforms, yielding high titers of transducing vector particles. Current specific productivity yields from different platforms range from 10 3 to 10 5 vector genomes (vg) per cell, and there is an ongoing effort to improve vector yields in order to satisfy high product demands required for clinical trials and future commercialization.Crucial aspects of vector production include the molecular design of the rAAV-producing host cell line along with the design of AAV genes, promoters, and regulatory elements. Appropriately, configuring and balancing the expression of these elements not only contributes toward high productivity, it also improves process robustness and product quality. In this mini-review, the rational design of rAAV-producing expression systems is discussed, with special attention to molecular strategies that contribute to high-yielding, biomanufacturing-amenable rAAV production processes. Details on molecular optimization from four rAAV expression systems are covered: adenovirus, herpesvirus, and baculovirus complementation systems, as well as a recently explored yeast expression system.

  13. Quantitative Molecular Detection of Putative Periodontal Pathogens in Clinically Healthy and Periodontally Diseased Subjects

    Science.gov (United States)

    Göhler, André; Hetzer, Adrian; Holtfreter, Birte; Geisel, Marie Henrike; Schmidt, Carsten Oliver; Steinmetz, Ivo; Kocher, Thomas

    2014-01-01

    Periodontitis is a multi-microbial oral infection with high prevalence among adults. Putative oral pathogens are commonly found in periodontally diseased individuals. However, these organisms can be also detected in the oral cavity of healthy subjects. This leads to the hypothesis, that alterations in the proportion of these organisms relative to the total amount of oral microorganisms, namely their abundance, rather than their simple presence might be important in the transition from health to disease. Therefore, we developed a quantitative molecular method to determine the abundance of various oral microorganisms and the portion of bacterial and archaeal nucleic acid relative to the total nucleic acid extracted from individual samples. We applied quantitative real-time PCRs targeting single-copy genes of periodontal bacteria and 16S-rRNA genes of Bacteria and Archaea. Testing tongue scrapings of 88 matched pairs of periodontally diseased and healthy subjects revealed a significantly higher abundance of P. gingivalis and a higher total bacterial abundance in diseased subjects. In fully adjusted models the risk of being periodontally diseased was significantly higher in subjects with high P. gingivalis and total bacterial abundance. Interestingly, we found that moderate abundances of A. actinomycetemcomitans were associated with reduced risk for periodontal disease compared to subjects with low abundances, whereas for high abundances, this protective effect leveled off. Moderate archaeal abundances were health associated compared to subjects with low abundances. In conclusion, our methodological approach unraveled associations of the oral flora with periodontal disease, which would have gone undetected if only qualitative data had been determined. PMID:25029268

  14. Endometrial transcription of microbial molecular patterns receptors in Gyr and F1 Holstein x Gyr postpartum cows

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    T.M. Martins

    Full Text Available ABSTRACT Zebu and Holstein x Zebu crossbred have low incidence of uterine infection when compared to Holstein cows. Resistance to uterine infections may be associated with the ability to recognize invading microorganisms. Endometrial transcription of microbial molecular patterns receptors has been investigated in the postpartum period of Holstein cows, but it is completely unknown in Zebu or Holstein x Zebu cows. In this study, 9 Gyr and 12 F1 Holstein x Gyr cows were submitted to endometrial biopsies at the first and seventh days postpartum, with the objective to measure transcription levels of toll-like receptors (TLRs 1/6, 2, 4, 5, and 9; nucleotide-binding oligomerization domain (NOD-like receptors 1 and 2; and coreceptors cluster of differentiation 14 (CD14 and myeloid differentiation protein-2 (MD-2. There was a significant (P<0.05 decrease in transcription of TLR5 in Gyr, and an increase in transcription of TLR9 in F1 cows, between the first and seventh day postpartum. Both groups had low incidences of uterine infections up to 42 days postpartum. Uterine involution completed at 27.7 ± 10.1 and 25.1 ± 4.7 days postpartum for Gyr and F1 cows, respectively. In Gyr cows, higher transcription levels of TLR1/6 and NOD1 correlated to a longer period required for uterine involution. In F1 cows, lower levels of TLR1/6, TLR2 and NOD2 correlated to a longer period required for uterine involution. In conclusion, some pathogen recognition receptors associated significantly with the time required for uterine involution in Gyr and F1 cows.

  15. Chemical signaling between plants and plant-pathogenic bacteria.

    Science.gov (United States)

    Venturi, Vittorio; Fuqua, Clay

    2013-01-01

    Studies of chemical signaling between plants and bacteria in the past have been largely confined to two models: the rhizobial-legume symbiotic association and pathogenesis between agrobacteria and their host plants. Recent studies are beginning to provide evidence that many plant-associated bacteria undergo chemical signaling with the plant host via low-molecular-weight compounds. Plant-produced compounds interact with bacterial regulatory proteins that then affect gene expression. Similarly, bacterial quorum-sensing signals result in a range of functional responses in plants. This review attempts to highlight current knowledge in chemical signaling that takes place between pathogenic bacteria and plants. This chemical communication between plant and bacteria, also referred to as interkingdom signaling, will likely become a major research field in the future, as it allows the design of specific strategies to create plants that are resistant to plant pathogens.

  16. Xanthomonas campestris lipooligosaccharides trigger innate immunity and oxidative burst in Arabidopsis

    NARCIS (Netherlands)

    Proietti, S; Giangrande, C; Amoresano, A; Pucci, P; Molinaro, A; Bertini, L; Caporale, C; Caruso, C

    2014-01-01

    Plants lack the adaptive immunity mechanisms of jawed vertebrates, so they rely on innate immune responses to defense themselves from pathogens. The plant immune system perceives the presence of pathogens by recognition of molecules known as pathogen-associated molecular patterns (PAMPs). PAMPs have

  17. Association of plasma 25-hydroxyvitamin d concentrations and pathogenic oral bacteria in postmenopausal females.

    Science.gov (United States)

    Sahli, Michelle W; Wactawski-Wende, Jean; Ram, Pavani K; LaMonte, Michael J; Hovey, Kathleen M; Genco, Robert J; Andrews, Christopher A; Millen, Amy E

    2014-07-01

    Previous findings of an association between 25-hydroxyvitamin D [25(OH)D] concentrations and periodontal disease may be partially explained by the antimicrobial properties of vitamin D. To the best of the authors' knowledge, no study has investigated the association between 25(OH)D and pathogenic oral bacteria, a putative cause of periodontal disease. The association between plasma 25(OH)D concentrations and pathogenic oral bacteria was examined among postmenopausal females in the Buffalo Osteoporosis and Periodontal Disease Study (1997 to 2000), an ancillary study of the Women's Health Initiative Observational Study. Subgingival plaque samples were assessed using immunofluorescence for the presence of Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, and Campylobacter rectus. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for prevalent bacteria by quintile (Q) of 25(OH)D concentrations, adjusting for age and body mass index. Of the 855 participants, 288 (34%) had deficient/inadequate (bacteria. No significant association was found between 25(OH)D and presence of any of these bacteria (adjusted OR for high [Q5] compared to low [Q1] 25(OH)D = 0.96; 95% CI: 0.61 to 1.50; P for trend = 0.50). Inverse, although not statistically significant, associations were found between 25(OH)D and more than one species of pathogenic bacteria (adjusted OR for adequate compared to deficient/inadequate 25(OH)D = 0.85; 95% CI: 0.60 to 1.19). No association was observed between pathogenic oral bacteria and 25(OH)D concentrations in postmenopausal females. This may be attributable to the species of bacteria assessed, small effect size, or a true absence of an association.

  18. Molecular detection and identification of Rickettsiales pathogens in dog ticks from Costa Rica.

    Science.gov (United States)

    Campos-Calderón, Liliana; Ábrego-Sánchez, Leyda; Solórzano-Morales, Antony; Alberti, Alberto; Tore, Gessica; Zobba, Rosanna; Jiménez-Rocha, Ana E; Dolz, Gaby

    2016-10-01

    Although vector-borne diseases are globally widespread with considerable impact on animal production and on public health, few reports document their presence in Central America. This study focuses on the detection and molecular identification of species belonging to selected bacterial genera (Ehrlichia, Anaplasma and Rickettsia) in ticks sampled from dogs in Costa Rica by targeting several genes: 16S rRNA/dsb genes for Ehrlichia; 16S rRNA/groEL genes for Anaplasma, and ompA/gltA/groEL genes for Rickettsia. PCR and sequence analyses provides evidences of Ehrlichia canis, Anaplasma platys, and Anaplasma phagocytophilum infection in Rhipicephalus sanguineus s.l ticks, and allow establishing the presence of Rickettsia monacensis in Ixodes boliviensis. Furthermore, the presence of recently discovered Mediterranean A. platys-like strains is reported for the first time in Central America. Results provide new background on geographical distribution of selected tick-transmitted bacterial pathogens in Costa Rica and on their molecular epidemiology, and are pivotal to the development of effective and reliable diagnostic tools in Central America. Copyright © 2016 Elsevier GmbH. All rights reserved.

  19. STUDY OF PATHOGENESIS AND ITS SENSITIVITY PATTERN IN UTI

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    Rajendra Prasad Kathula

    2016-06-01

    Full Text Available BACKGROUND Urinary tract infections are common causes of both community acquired and nosocomial infections in adult patients admitted in the hospitals. Urinary tract infections can be defined as the presence of pathogenic bacteria in significant colony count in the bladder of upper urinary tract with its associated consequences. Asymptomatic bacteriuria is a term used to designate urinary tract infections in the absence of symptoms with the growth of bacteria colonies often crossing 1,00,000/mL in a freshly voided midstream urine sample. Urethritis and cystitis are characterised by the inflammation of the urethra and bladder with symptoms of dysuria, frequency and lower pubic pain and it is associated with fever. Acute pyelonephritis is the bacterial infection of renal parenchyma and it is characterised by fever with rigors, flank pain, vomiting, costovertebral tenderness with or without symptoms of cystitis. It may be associated with pus formation. Prostatitis is quiet common and it involves infective inflammation of the prostate associated with dysuria, urgency, frequency and pain in the lower abdomen, perineum, or base of the penis. A sincere effort has been made towards this study on pathogenesis and its sensitivity pattern in UTI. METHODS One hundred cases who visited the Department of Surgery, Government Medical College, Nizamabad were used as the sample size of the study. The plethora of the signs and symptoms which were seen were noted and the mid catch of the urine was done and sent to the Department of Microbiology for the pathogens to be identified. The sensitivity pattern was also studied and reported. The study was done from October 2012 to November 2013. RESULT The most common pathogen was E. coli and the most sensitivity of the commonest pathogen (E. coli was found to be towards Nitrofurantoin. CONCLUSION In this study, the most common pathogens which causes the UTI and the sensitivity pattern has been reported. The study is

  20. Morphological and molecular characterization of fungal pathogen, Magnaphorthe oryzae

    International Nuclear Information System (INIS)

    Hasan, Nor’Aishah; Rafii, Mohd Y.; Rahim, Harun A.; Ali, Nusaibah Syd; Mazlan, Norida; Abdullah, Shamsiah

    2016-01-01

    Rice is arguably the most crucial food crops supplying quarter of calories intake. Fungal pathogen, Magnaphorthe oryzae promotes blast disease unconditionally to gramineous host including rice species. This disease spurred an outbreaks and constant threat to cereal production. Global rice yield declining almost 10-30% including Malaysia. As Magnaphorthe oryzae and its host is model in disease plant study, the rice blast pathosystem has been the subject of intense interest to overcome the importance of the disease to world agriculture. Therefore, in this study, our prime objective was to isolate samples of Magnaphorthe oryzae from diseased leaf obtained from MARDI Seberang Perai, Penang, Malaysia. Molecular identification was performed by sequences analysis from internal transcribed spacer (ITS) region of nuclear ribosomal RNA genes. Phylogenetic affiliation of the isolated samples were analyzed by comparing the ITS sequences with those deposited in the GenBank database. The sequence of the isolate demonstrated at least 99% nucleotide identity with the corresponding sequence in GenBank for Magnaphorthe oryzae. Morphological observed under microscope demonstrated that the structure of conidia followed similar characteristic as M. oryzae. Finding in this study provide useful information for breeding programs, epidemiology studies and improved disease management

  1. Morphological and molecular characterization of fungal pathogen, Magnaphorthe oryzae

    Science.gov (United States)

    Hasan, Nor'Aishah; Rafii, Mohd Y.; Rahim, Harun A.; Ali, Nusaibah Syd; Mazlan, Norida; Abdullah, Shamsiah

    2016-02-01

    Rice is arguably the most crucial food crops supplying quarter of calories intake. Fungal pathogen, Magnaphorthe oryzae promotes blast disease unconditionally to gramineous host including rice species. This disease spurred an outbreaks and constant threat to cereal production. Global rice yield declining almost 10-30% including Malaysia. As Magnaphorthe oryzae and its host is model in disease plant study, the rice blast pathosystem has been the subject of intense interest to overcome the importance of the disease to world agriculture. Therefore, in this study, our prime objective was to isolate samples of Magnaphorthe oryzae from diseased leaf obtained from MARDI Seberang Perai, Penang, Malaysia. Molecular identification was performed by sequences analysis from internal transcribed spacer (ITS) region of nuclear ribosomal RNA genes. Phylogenetic affiliation of the isolated samples were analyzed by comparing the ITS sequences with those deposited in the GenBank database. The sequence of the isolate demonstrated at least 99% nucleotide identity with the corresponding sequence in GenBank for Magnaphorthe oryzae. Morphological observed under microscope demonstrated that the structure of conidia followed similar characteristic as M. oryzae. Finding in this study provide useful information for breeding programs, epidemiology studies and improved disease management.

  2. Deconstructing host-pathogen interactions in Drosophila

    Directory of Open Access Journals (Sweden)

    Ethan Bier

    2012-01-01

    Full Text Available Many of the cellular mechanisms underlying host responses to pathogens have been well conserved during evolution. As a result, Drosophila can be used to deconstruct many of the key events in host-pathogen interactions by using a wealth of well-developed molecular and genetic tools. In this review, we aim to emphasize the great leverage provided by the suite of genomic and classical genetic approaches available in flies for decoding details of host-pathogen interactions; these findings can then be applied to studies in higher organisms. We first briefly summarize the general strategies by which Drosophila resists and responds to pathogens. We then focus on how recently developed genome-wide RNA interference (RNAi screens conducted in cells and flies, combined with classical genetic methods, have provided molecular insight into host-pathogen interactions, covering examples of bacteria, fungi and viruses. Finally, we discuss novel strategies for how flies can be used as a tool to examine how specific isolated virulence factors act on an intact host.

  3. WHEAT PATHOGEN RESISTANCE AND CHITINASE PROFILE

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    Zuzana Gregorová

    2015-02-01

    Full Text Available The powdery mildew and leaf rust caused by Blumeria graminis and Puccinia recondita (respectively are common diseases of wheat throughout the world. These fungal diseases greatly affect crop productivity. Incorporation of effective and durable disease resistance is an important breeding objective for wheat improvement. We have evaluated resistance of four bread wheat (Triticum aestivum and four spelt wheat (Triticum spelta cultivars. Chitinases occurrence as well as their activity was determined in leaf tissues. There was no correlation between resistance rating and activity of chitinase. The pattern of chitinases reveals four isoforms with different size in eight wheat cultivars. A detailed understanding of the molecular events that take place during a plant–pathogen interaction is an essential goal for disease control in the future.

  4. [Evolution of pathogenic micro-organisms as a challenge for medicine].

    Science.gov (United States)

    Vaara, Martti

    2009-01-01

    Successful parasitic micro-organisms are able to adapt to the circumstances of the host's organ system, and it is usually not expedient for them to kill their host. Under selection pressure, the evolution of micro-organisms is vastly quicker that that of man. The selection pressure brought about by rapid ecological changes and alterations associated with human action provides for the development of new, dangerous pathogens and transformation of familiar pathogens to become more dangerous. Progress in molecular biology has thus far not yielded as many new tools for the treatment of infectious diseases as the hopes were in the early 2000's.

  5. Comparative proteomic analysis of pathogenic and non-pathogenic strains from the swine pathogen Mycoplasma hyopneumoniae

    Directory of Open Access Journals (Sweden)

    Klein Cátia S

    2009-12-01

    Full Text Available Abstract Background Mycoplasma hyopneumoniae is a highly infectious swine pathogen and is the causative agent of enzootic pneumonia (EP. Following the previous report of a proteomic survey of the pathogenic 7448 strain of swine pathogen, Mycoplasma hyopneumoniae, we performed comparative protein profiling of three M. hyopneumoniae strains, namely the non-pathogenic J strain and the two pathogenic strains 7448 and 7422. Results In 2DE comparisons, we were able to identify differences in expression levels for 67 proteins, including the overexpression of some cytoadherence-related proteins only in the pathogenic strains. 2DE immunoblot analyses allowed the identification of differential proteolytic cleavage patterns of the P97 adhesin in the three strains. For more comprehensive protein profiling, an LC-MS/MS strategy was used. Overall, 35% of the M. hyopneumoniae genome coding capacity was covered. Partially overlapping profiles of identified proteins were observed in the strains with 81 proteins identified only in one strain and 54 proteins identified in two strains. Abundance analysis of proteins detected in more than one strain demonstrates the relative overexpression of 64 proteins, including the P97 adhesin in the pathogenic strains. Conclusions Our results indicate the physiological differences between the non-pathogenic strain, with its non-infective proliferate lifestyle, and the pathogenic strains, with its constitutive expression of adhesins, which would render the bacterium competent for adhesion and infection prior to host contact.

  6. Impact of climate trends on tick-borne pathogen transmission

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    Agustin eEstrada-Pena

    2012-03-01

    Full Text Available Recent advances in climate research together with a better understanding of tick-pathogen interactions, the distribution of ticks and the diagnosis of tick-borne pathogens raise questions about the impact of environmental factors on tick abundance and spread and the prevalence and transmission of tick-borne pathogens. While undoubtedly climate plays a role in the changes in distribution and seasonal abundance of ticks, it is always difficult to disentangle factors impacting on the abundance of tick hosts from those exerted by human habits. All together, climate, host abundance and social factors may explain the upsurge of epidemics transmitted by ticks to humans. Herein we focused on tick-borne pathogens that affect humans with pandemic potential. Borrelia burgdorferi s.l. (Lyme disease, Anaplasma phagocytophilum (human granulocytic anaplasmosis and tick-borne encephalitis virus (tick-borne encephalitis are transmitted by Ixodes spp. Crimean-Congo hemorrhagic fever virus (Crimean-Congo hemorrhagic fever is transmitted by Hyalomma spp. In this review, we discussed how vector tick species occupy the habitat as a function of different climatic factors, and how these factors impact on tick survival and seasonality. How molecular events at the tick-pathogen interface impact on pathogen transmission is also discussed. Results from statistically and biologically derived models are compared to show that while statistical models are able to outline basic information about tick distributions, biologically derived models are necessary to evaluate pathogen transmission rates and understand the effect of climatic variables and host abundance patterns on pathogen transmission. The results of these studies could be used to build early alert systems able to identify the main factors driving the subtle changes in tick distribution and seasonality and the prevalence of tick-borne pathogens.

  7. Genetics-based interactions among plants, pathogens, and herbivores define arthropod community structure.

    Science.gov (United States)

    Busby, Posy E; Lamit, Louis J; Keith, Arthur R; Newcombe, George; Gehring, Catherine A; Whitham, Thomas G; Dirzo, Rodolfo

    2015-07-01

    Plant resistance to pathogens or insect herbivores is common, but its potential for indirectly influencing plant-associated communities is poorly known. Here, we test whether pathogens' indirect effects on arthropod communities and herbivory depend on plant resistance to pathogens and/or herbivores, and address the overarching interacting foundation species hypothesis that genetics-based interactions among a few highly interactive species can structure a much larger community. In a manipulative field experiment using replicated genotypes of two Populus species and their interspecific hybrids, we found that genetic variation in plant resistance to both pathogens and insect herbivores modulated the strength of pathogens' indirect effects on arthropod communities and insect herbivory. First, due in part to the pathogens' differential impacts on leaf biomass among the two Populus species and the hybrids, the pathogen most strongly impacted arthropod community composition, richness, and abundance on the pathogen-susceptible tree species. Second, we found similar patterns comparing pathogen-susceptible and pathogen-resistant genotypes within species. Third, within a plant species, pathogens caused a fivefold greater reduction in herbivory on insect-herbivore-susceptible plant genotypes than on herbivore-resistant genotypes, demonstrating that the pathogen-herbivore interaction is genotype dependent. We conclude that interactions among plants, pathogens, and herbivores can structure multitrophic communities, supporting the interacting foundation species hypothesis. Because these interactions are genetically based, evolutionary changes in genetic resistance could result in ecological changes in associated communities, which may in turn feed back to affect plant fitness.

  8. Biodiversity, molecular ecology and phylogeography of marine sponges: patterns, implications and outlooks.

    Science.gov (United States)

    Wörheide, Gert; Solé-Cava, Antonio M; Hooper, John N A

    2005-04-01

    Marine sponges are an ecologically important and highly diverse component of marine benthic communities, found in all the world's oceans, at all depths. Although their commercial potential and evolutionary importance is increasingly recognized, many pivotal aspects of their basic biology remain enigmatic. Knowledge of historical biogeographic affinities and biodiversity patterns is rudimentary, and there are still few data about genetic variation among sponge populations and spatial patterns of this variation. Biodiversity analyses of tropical Australasian sponges revealed spatial trends not universally reflected in the distributions of other marine phyla within the Indo-West Pacific region. At smaller spatial scales sponges frequently form heterogeneous, spatially patchy assemblages, with some empirical evidence suggesting that environmental variables such as light and/or turbidity strongly contribute to local distributions. There are no apparent latitudinal diversity gradients at larger spatial scales but stochastic processes, such as changing current patterns, the presence or absence of major carbonate platforms and historical biogeography, may determine modern day distributions. Studies on Caribbean oceanic reefs have revealed similar patterns, only weakly correlated with environmental factors. However, several questions remain where molecular approaches promise great potential, e.g., concerning connectivity and biogeographic relationships. Studies to date have helped to reveal that sponge populations are genetically highly structured and that historical processes might play an important role in determining such structure. Increasingly sophisticated molecular tools are now being applied, with results contributing significantly to a better understanding of poriferan microevolutionary processes and molecular ecology.

  9. Molecular-based detection of the gastrointestinal pathogen Campylobacter ureolyticus in unpasteurized milk samples from two cattle farms in Ireland

    Directory of Open Access Journals (Sweden)

    Koziel Monika

    2012-11-01

    Full Text Available Abstract Campylobacter jejuni and coli are collectively regarded as the most prevalent cause of bacterial foodborne illness worldwide. An emerging species, Campylobacter ureolyticus has recently been detected in patients with gastroenteritis, however, the source of this organism has, until now, remained unclear. Herein, we describe the molecular-based detection of this pathogen in bovine faeces (1/20 and unpasteurized milk (6/47 but not in poultry (chicken wings and caeca. This is, to the best of our knowledge, the first report of the presence of this potential gastrointestinal pathogen in an animal source, possibly suggesting a route for its transmission to humans.

  10. Novel adjuvant based on a proteoliposome-derived cochleate structure containing native lipopolysaccharide as a pathogen-associated molecular pattern.

    Science.gov (United States)

    Pérez, Oliver; Bracho, Gustavo; Lastre, Miriam; Mora, Nestor; del Campo, Judith; Gil, Danay; Zayas, Caridad; Acevedo, Reinaldo; González, Domingo; López, José A; Taboada, Carlos; Turtle, Cameron; Solis, Rosa L

    2004-12-01

    Proteoliposomes (PL) from Neisseria meningitidis B have been widely used as a core antigen for antimeningococcal vaccination. PL contain major outer membrane proteins, LPS and phospholipids, and they induce a strong Th1 immune response, but they have low stability in solution. Attending to the need for new vaccine adjuvants, we developed a highly stable cochleate structure (CS) from PL using a technology that allows easy incorporation of new antigens. We explored the ability of PLCS to activate the immune system and its possible application as an adjuvant for parenteral and mucosal routes. Our results showed that PLCS were able to upregulate the expression of MHC class II and costimulatory molecules on human dendritic cells, as well as being able to stimulate the production of soluble mediators of a Th1 response, such as IL-12 and nitric oxide. High levels of anti-PL IgG were detected in serum after i.m. or mucosal (oral and nasal) administration, but also anti-PL secretory IgA was produced in saliva following nasal delivery. The immune response polarization to a Th1 pattern was confirmed by the induction of IgG2a antibodies, positive delayed type hypersensitivity reactions, and IFN-gamma production by splenocytes from immunized mice. The adjuvant potential was explored using PLCS containing ovalbumin (Ova). PLCS-Ova was able to elicit a substantial increase in anti-Ova IgG compared with Ova alone. In addition, a significant reduction in lesion size was observed in mice immunized with Leishmania major antigens in PLCS after challenge with virulent protozoa, suggesting at least partial modulation of the Th2 environment induced by this parasite. In conclusion, our results support the use of PLCS as a potent Th1 adjuvant for parenteral and mucosal vaccines.

  11. A comprehensive data mining study shows that most nuclear receptors act as newly proposed homeostasis-associated molecular pattern receptors.

    Science.gov (United States)

    Wang, Luqiao; Nanayakkara, Gayani; Yang, Qian; Tan, Hongmei; Drummer, Charles; Sun, Yu; Shao, Ying; Fu, Hangfei; Cueto, Ramon; Shan, Huimin; Bottiglieri, Teodoro; Li, Ya-Feng; Johnson, Candice; Yang, William Y; Yang, Fan; Xu, Yanjie; Xi, Hang; Liu, Weiqing; Yu, Jun; Choi, Eric T; Cheng, Xiaoshu; Wang, Hong; Yang, Xiaofeng

    2017-10-24

    Nuclear receptors (NRs) can regulate gene expression; therefore, they are classified as transcription factors. Despite the extensive research carried out on NRs, still several issues including (1) the expression profile of NRs in human tissues, (2) how the NR expression is modulated during atherosclerosis and metabolic diseases, and (3) the overview of the role of NRs in inflammatory conditions are not fully understood. To determine whether and how the expression of NRs are regulated in physiological/pathological conditions, we took an experimental database analysis to determine expression of all 48 known NRs in 21 human and 17 murine tissues as well as in pathological conditions. We made the following significant findings: (1) NRs are differentially expressed in tissues, which may be under regulation by oxygen sensors, angiogenesis pathway, stem cell master regulators, inflammasomes, and tissue hypo-/hypermethylation indexes; (2) NR sequence mutations are associated with increased risks for development of cancers and metabolic, cardiovascular, and autoimmune diseases; (3) NRs have less tendency to be upregulated than downregulated in cancers, and autoimmune and metabolic diseases, which may be regulated by inflammation pathways and mitochondrial energy enzymes; and (4) the innate immune sensor inflammasome/caspase-1 pathway regulates the expression of most NRs. Based on our findings, we propose a new paradigm that most nuclear receptors are anti-inflammatory homeostasis-associated molecular pattern receptors (HAMPRs). Our results have provided a novel insight on NRs as therapeutic targets in metabolic diseases, inflammations, and malignancies.

  12. Association between pathogens from tracheal aspirate and oral biofilm of patients on mechanical ventilation.

    Science.gov (United States)

    Souza, Luana Carneiro Diniz; Mota, Vanise Barros Rodrigues da; Carvalho, Alícia Valéria Dos Santos Zaranza de; Corrêa, Rita da Graça Carvalhal Frazão; Libério, Silvana Amado; Lopes, Fernanda Ferreira

    2017-06-05

    The aim of this study was to detect possible associations between respiratory pathogens from tracheal aspirate and oral biofilm samples in intubated patients in an intensive care unit (ICU), and to identify the most common respiratory pathogens in oral biofilm, particularly in patients that developed ventilator-associated pneumonia (VAP). Two oral biofilm samples were collected from the tongue of intubated patients (at admission and after 48 hours) and analyzed by culture with the Antibiotic Sensitivity Test. The results from the tongue biofilm samples were compared with the tracheal secretions samples. A total of 59.37% of patients exhibited the same species of pathogens in their tracheal aspirate and oral biofilm, of which 8 (42.1%) developed VAP, 10 (52.63%) did not develop pneumonia and one (5.26%) had aspiration pneumonia. There was a statistically significant association between presence of microorganisms in the tracheal and mouth samples for the following pathogens: Klebsiella pneumoniae, Candida albicans, Pseudomonas aeruginosa, Enterobacter gergoviae, Streptococcus spp and Serratia marcescens (p aspirates of intubated patients can be detected in their oral cavity, especially in those who developed VAP or aspiration pneumonia. Thus, the results indicate that an improved oral care in these patients could decrease ICU pneumonia rates.

  13. M-ficolin, an innate immune defence molecule, binds patterns of acetyl groups and activates complement

    DEFF Research Database (Denmark)

    Frederiksen, Pernille Dorthea; Thiel, Steffen; Larsen, Claus Bindslev

    2005-01-01

    Ficolins play a role in the innate immune defence as pathogen-associated molecular pattern recognition molecules. Three ficolins are found in humans: H-ficolin, L-ficolin and M-ficolin. L-ficolin and H-ficolin circulate in blood in complexes with mannan-binding lectin-associated serine proteases...... (MASPs) and are capable of activating the complement system. L-ficolin shows affinity for acetylated compounds and binds to various capsulated strains of bacteria. H-ficolin has been shown to bind Aerococcus viridans. Less is known about M-ficolin, but it is thought to be present only on monocytes. We...... system. We developed a monoclonal rat anti-human-M/L-ficolin antibody and verified by flow cytometric analysis the presence of ficolin on the surface of peripheral blood monocytes....

  14. Comparison of Methods to Identify Pathogens and Associated Virulence Functional Genes in Biosolids from Two Different Wastewater Treatment Facilities in Canada.

    Directory of Open Access Journals (Sweden)

    Etienne Yergeau

    Full Text Available The use of treated municipal wastewater residues (biosolids as fertilizers is an attractive, inexpensive option for growers and farmers. Various regulatory bodies typically employ indicator organisms (fecal coliforms, E. coli and Salmonella to assess the adequacy and efficiency of the wastewater treatment process in reducing pathogen loads in the final product. Molecular detection approaches can offer some advantages over culture-based methods as they can simultaneously detect a wider microbial species range, including non-cultivable microorganisms. However, they cannot directly assess the viability of the pathogens. Here, we used bacterial enumeration methods together with molecular methods including qPCR, 16S rRNA and cpn60 gene amplicon sequencing and shotgun metagenomic sequencing to compare pre- and post-treatment biosolids from two Canadian wastewater treatment plants (WWTPs. Our results show that an anaerobic digestion WWTP was unsuccessful at reducing the live indicator organism load (coliforms, generic E. coli and Salmonella below acceptable regulatory criteria, while biosolids from a dewatering/pelletization WWTP met these criteria. DNA from other pathogens was detected by the molecular methods, but these species were considered less abundant. Clostridium DNA increased significantly following anaerobic digestion treatments. In addition to pathogen DNA, genes related to virulence and antibiotic resistance were identified in treated biosolids. Shotgun metagenomics revealed the widest range of pathogen DNA and, among the approaches used here, was the only approach that could access functional gene information in treated biosolids. Overall, our results highlight the potential usefulness of amplicon sequencing and shotgun metagenomics as complementary screening methods that could be used in parallel with culture-based methods, although more detailed comparisons across a wider range of sites would be needed.

  15. Spatiotemporal structure of molecular evolution of H5N1 highly pathogenic avian influenza viruses in Vietnam.

    Science.gov (United States)

    Carrel, Margaret A; Emch, Michael; Jobe, R Todd; Moody, Aaron; Wan, Xiu-Feng

    2010-01-08

    Vietnam is one of the countries most affected by outbreaks of H5N1 highly pathogenic avian influenza viruses. First identified in Vietnam in poultry in 2001 and in humans in 2004, the virus has since caused 111 cases and 56 deaths in humans. In 2003/2004 H5N1 outbreaks, nearly the entire poultry population of Vietnam was culled. Our earlier study (Wan et al., 2008, PLoS ONE, 3(10): e3462) demonstrated that there have been at least six independent H5N1 introductions into Vietnam and there were nine newly emerged reassortants from 2001 to 2007 in Vietnam. H5N1 viruses in Vietnam cluster distinctly around Hanoi and Ho Chi Minh City. However, the nature of the relationship between genetic divergence and geographic patterns is still unclear. In this study, we hypothesized that genetic distances between H5N1 viruses in Vietnam are correlated with geographic distances, as the result of distinct population and environment patterns along Vietnam's long north to south longitudinal extent. Based on this hypothesis, we combined spatial statistical methods with genetic analytic techniques and explicitly used geographic space to explore genetic evolution of H5N1 highly pathogenic avian influenza viruses at the sub-national scale in Vietnam. Our dataset consisted of 125 influenza viruses (with whole genome sets) isolated in Vietnam from 2003 to 2007. Our results document the significant effect of space and time on genetic evolution and the rise of two regional centers of genetic mixing by 2007. These findings give insight into processes underlying viral evolution and suggest that genetic differentiation is associated with the distance between concentrations of human and poultry populations around Hanoi and Ho Chi Minh City. The results show that genetic evolution of H5N1 viruses in Vietnamese domestic poultry is highly correlated with the location and spread of those viruses in geographic space. This correlation varies by scale, time, and gene, though a classic isolation by

  16. Gene expression patterns in blood leukocytes discriminate patients with acute infections

    Science.gov (United States)

    Allman, Windy; Chung, Wendy; Mejias, Asuncion; Ardura, Monica; Glaser, Casey; Wittkowski, Knut M.; Piqueras, Bernard; Banchereau, Jacques; Palucka, A. Karolina; Chaussabel, Damien

    2007-01-01

    Each infectious agent represents a unique combination of pathogen-associated molecular patterns that interact with specific pattern-recognition receptors expressed on immune cells. Therefore, we surmised that the blood immune cells of individuals with different infections might bear discriminative transcriptional signatures. Gene expression profiles were obtained for 131 peripheral blood samples from pediatric patients with acute infections caused by influenza A virus, Gram-negative (Escherichia coli) or Gram-positive (Staphylococcus aureus and Streptococcus pneumoniae) bacteria. Thirty-five genes were identified that best discriminate patients with influenza A virus infection from patients with either E coli or S pneumoniae infection. These genes classified with 95% accuracy (35 of 37 samples) an independent set of patients with either influenza A, E coli, or S pneumoniae infection. A different signature discriminated patients with E coli versus S aureus infections with 85% accuracy (34 of 40). Furthermore, distinctive gene expression patterns were observed in patients presenting with respiratory infections of different etiologies. Thus, microarray analyses of patient peripheral blood leukocytes might assist in the differential diagnosis of infectious diseases. PMID:17105821

  17. An Overview of Pathogen Recognition Receptors for Innate Immunity in Dental Pulp

    Directory of Open Access Journals (Sweden)

    Ji-Hyun Jang

    2015-01-01

    Full Text Available Pathogen recognition receptors (PRRs are a class of germ line-encoded receptors that recognize pathogen-associated molecular patterns (PAMPs. The activation of PRRs is crucial for the initiation of innate immunity, which plays a key role in first-line defense until more specific adaptive immunity is developed. PRRs differ in the signaling cascades and host responses activated by their engagement and in their tissue distribution. Currently identified PRR families are the Toll-like receptors (TLRs, the C-type lectin receptors (CLRs, the nucleotide-binding oligomerization domain-like receptors (NLRs, the retinoic acid-inducible gene-I-like receptors (RLRs, and the AIM2-like receptor (ALR. The environment of the dental pulp is substantially different from that of other tissues of the body. Dental pulp resides in a low compliance root canal system that limits the expansion of pulpal tissues during inflammatory processes. An understanding of the PRRs in dental pulp is important for immunomodulation and hence for developing therapeutic targets in the field of endodontics. Here we comprehensively review recent finding on the PRRs and the mechanisms by which innate immunity is activated. We focus on the PRRs expressed on dental pulp and periapical tissues and their role in dental pulp inflammation.

  18. Convergent and Divergent Signaling in PAMP-Triggered Immunity and Effector-Triggered Immunity.

    Science.gov (United States)

    Peng, Yujun; van Wersch, Rowan; Zhang, Yuelin

    2018-04-01

    Plants use diverse immune receptors to sense pathogen attacks. Recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors localized on the plasma membrane leads to PAMP-triggered immunity (PTI). Detection of pathogen effectors by intracellular or plasma membrane-localized immune receptors results in effector-triggered immunity (ETI). Despite the large variations in the magnitude and duration of immune responses triggered by different PAMPs or pathogen effectors during PTI and ETI, plasma membrane-localized immune receptors activate similar downstream molecular events such as mitogen-activated protein kinase activation, oxidative burst, ion influx, and increased biosynthesis of plant defense hormones, indicating that defense signals initiated at the plasma membrane converge at later points. On the other hand, activation of ETI by immune receptors localized to the nucleus appears to be more directly associated with transcriptional regulation of defense gene expression. Here, we review recent progress in signal transductions downstream of different groups of plant immune receptors, highlighting the converging and diverging molecular events.

  19. Epidemiology of bacterial pathogens associated with infectious diarrhea in Djibouti.

    Science.gov (United States)

    Mikhail, I A; Fox, E; Haberberger, R L; Ahmed, M H; Abbatte, E A

    1990-01-01

    During a survey examining the causes of diarrhea in the East African country of Djibouti, 140 bacterial pathogens were recovered from 209 diarrheal and 100 control stools. The following pathogens were isolated at comparable frequencies from both diarrheal and control stools: enteroadherent Escherichia coli (EAEC) (10.6 versus 13%), enterotoxigenic E. coli (ETEC) (11 versus 10%), enteropathogenic E. coli (EPEC) (7.7 versus 12%), Salmonella spp. (2.9 versus 3%), and Campylobacter jejuni-C. coli (3.3 versus 5%). Surprisingly, the EAEC strains isolated did not correspond to well-recognized EPEC serogroups. No Yersinia spp., enteroinvasive E. coli, or enterohemorrhagic E. coli were isolated during the course of this study. Only the following two genera were recovered from diarrheal stools exclusively: Shigella spp. (7.7%) and Aeromonas hydrophila group organisms (3.3%). Shigella flexneri was the most common Shigella species isolated. Patients with Shigella species were of a higher average age than were controls (27 versus 13 years), while subjects with Campylobacter or Salmonella species belonged to younger age groups (2.6 and 1.6 years, respectively). Salmonella cases were more often in females. Shigella diarrhea was associated with fecal blood or mucus and leukocytes. ETEC was not associated with nausea or vomiting. Anorexia, weight loss, and fever were associated with the isolation of Salmonella and Aeromonas species. EAEC, ETEC, EPEC, and Shigella species were resistant to most drugs used for treating diarrhea in Africa, while the antibiotic most active against all bacteria tested was norfloxacin. We conclude that in Djibouti in 1989, Shigella and Aeromonas species must be considered as potential pathogens whenever they are isolated from diarrheal stools and that norfloxacin should be considered the drug of choice in adults for treating severe shigellosis and for diarrhea prophylaxis in travelers. PMID:2351738

  20. Molecular methods for pathogen and microbial community detection and characterization: current and potential application in diagnostic microbiology.

    Science.gov (United States)

    Sibley, Christopher D; Peirano, Gisele; Church, Deirdre L

    2012-04-01

    Clinical microbiology laboratories worldwide have historically relied on phenotypic methods (i.e., culture and biochemical tests) for detection, identification and characterization of virulence traits (e.g., antibiotic resistance genes, toxins) of human pathogens. However, limitations to implementation of molecular methods for human infectious diseases testing are being rapidly overcome allowing for the clinical evaluation and implementation of diverse technologies with expanding diagnostic capabilities. The advantages and limitation of molecular techniques including real-time polymerase chain reaction, partial or whole genome sequencing, molecular typing, microarrays, broad-range PCR and multiplexing will be discussed. Finally, terminal restriction fragment length polymorphism (T-RFLP) and deep sequencing are introduced as technologies at the clinical interface with the potential to dramatically enhance our ability to diagnose infectious diseases and better define the epidemiology and microbial ecology of a wide range of complex infections. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Molecular-based detection of potentially pathogenic bacteria in membrane bioreactor (MBR) systems treating municipal wastewater: a case study.

    Science.gov (United States)

    Harb, Moustapha; Hong, Pei-Ying

    2017-02-01

    Although membrane bioreactor (MBR) systems provide better removal of pathogens compared to conventional activated sludge processes, they do not achieve total log removal. The present study examines two MBR systems treating municipal wastewater, one a full-scale MBR plant and the other a lab-scale anaerobic MBR. Both of these systems were operated using microfiltration (MF) polymeric membranes. High-throughput sequencing and digital PCR quantification were utilized to monitor the log removal values (LRVs) of associated pathogenic species and their abundance in the MBR effluents. Results showed that specific removal rates vary widely regardless of the system employed. Each of the two MBR effluents' microbial communities contained genera associated with opportunistic pathogens (e.g., Pseudomonas, Acinetobacter) with a wide range of log reduction values (5.5). Digital PCR further confirmed that these bacterial groups included pathogenic species, in several instances at LRVs different than those for their respective genera. These results were used to evaluate the potential risks associated both with the reuse of the MBR effluents for irrigation purposes and with land application of the activated sludge from the full-scale MBR system.

  2. Molecular-based detection of potentially pathogenic bacteria in membrane bioreactor (MBR) systems treating municipal wastewater: a case study

    KAUST Repository

    Harb, Moustapha

    2016-12-24

    Although membrane bioreactor (MBR) systems provide better removal of pathogens compared to conventional activated sludge processes, they do not achieve total log removal. The present study examines two MBR systems treating municipal wastewater, one a full-scale MBR plant and the other a lab-scale anaerobic MBR. Both of these systems were operated using microfiltration (MF) polymeric membranes. High-throughput sequencing and digital PCR quantification were utilized to monitor the log removal values (LRVs) of associated pathogenic species and their abundance in the MBR effluents. Results showed that specific removal rates vary widely regardless of the system employed. Each of the two MBR effluents’ microbial communities contained genera associated with opportunistic pathogens (e.g., Pseudomonas, Acinetobacter) with a wide range of log reduction values (< 2 to >5.5). Digital PCR further confirmed that these bacterial groups included pathogenic species, in several instances at LRVs different than those for their respective genera. These results were used to evaluate the potential risks associated both with the reuse of the MBR effluents for irrigation purposes and with land application of the activated sludge from the full-scale MBR system.

  3. The association between subgingival periodontal pathogens and systemic inflammation.

    Science.gov (United States)

    Winning, Lewis; Patterson, Christopher C; Cullen, Kathy M; Stevenson, Kathryn A; Lundy, Fionnuala T; Kee, Frank; Linden, Gerard J

    2015-09-01

    To investigate associations between periodontal disease pathogens and levels of systemic inflammation measured by C-reactive protein (CRP). A representative sample of dentate 60-70-year-old men in Northern Ireland had a comprehensive periodontal examination. Men taking statins were excluded. Subgingival plaque samples were analysed by quantitative real time PCR to identify the presence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia. High-sensitivity CRP (mg/l) was measured from fasting blood samples. Multiple linear regression analysis was performed using log-transformed CRP concentration as the dependent variable, with the presence of each periodontal pathogen as predictor variables, with adjustment for various potential confounders. A total of 518 men (mean age 63.6 SD 3.0 years) were included in the analysis. Multiple regression analysis showed that body mass index (p C-reactive protein. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Prevalence of Multidrug-Resistant Pathogens and Their Antibiotic Susceptibility Pattern from Late-Onset Ventilator-Associated Pneumonia Patients from a Tertiary-Care Hospital in North India

    Directory of Open Access Journals (Sweden)

    Varsha Gupta

    2018-01-01

    Full Text Available Background: Ventilator-associated pneumonia (VAP is seen as being most common in critically ill patients in intensive care units. Diagnostic protocol is challenging and the treatment is often difficult. Incorrectly selected antibiotic therapy further leads to the emergence of multidrug-resistant (MDR organisms. Materials and Methods: The present prospective study was conducted to study patients of VAP with the aim of determining the aerobic bacterial etiological agents, antimicrobial susceptibility patterns, and molecular detection of MBL (metallo beta lactamase genes. The antimicrobial susceptibility of the isolates by the disc diffusion method and the detection of various drug-resistance mechanisms was done. The minimum inhibitory concentration (MIC based on E-test was determined along with the molecular analysis by polymerase chain reaction for detection of MBL genes (IMP and VIM. Results: Out of a total of 372 patients admitted in intensive care unit during the time period (March 2010 to February 2013, 40 patients were finally diagnosed as having late-onset VAP. Among the study isolates (69, due to polymicrobial infection, the maximum isolates were Acinetobacter spp. (32 followed by Pseudomonas aeruginosa (18, Klebsiella pneumoniae (8, and others. MDR was high with 34% of Acinetobacter and 50% of Pseudomonas strains being MBL producers. Among Staphylococcus aureus, 50% strains were methicillin resistant. On molecular analysis, eight of the Acinetobacter and six of the Pseudomonas isolates came out to be positive for VIM 2 gene, whereas IMP was not detected in any of the isolates. Conclusion: The present study emphasizes the threat of MDR in VAP patients from ICU as the treatment options are limited. The knowledge of prevailing organisms, resistance mechanisms, and their antibiotic profile can go a long way in deciding appropriate empirical therapy.

  5. Molecular Alterations Associated with DNA Repair in Pancreatic Adenocarcinoma Are Associated with Sites of Recurrence.

    Science.gov (United States)

    Ferguson, Margaret D; Dong, Lei; Wan, Jim; Deneve, Jeremiah L; Dickson, Paxton V; Behrman, Stephen W; Shibata, David; Martin, Mike G; Glazer, Evan S

    2018-02-10

    Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest malignancies with a rising incidence. Mutational analysis of PDAC has provided valuable information but has not yet dramatically changed the therapeutic landscape due to the number of variations detected in any one individual. The pattern of molecular alterations-gene mutations, variations in copy number, and changes in gene expression-has been described in the literature. The purpose of this study is to further investigate the molecular alterations in recurrent or metastatic PDAC based on the site of disease. Molecular alterations in patients with recurrent or metastatic PDAC from 2007 to 2015 were analyzed. The most common molecular alterations found in PDAC tumors from the pancreas were compared to metastatic PDAC specimens from the liver, lung, peritoneum, and other locations. Means were compared with a two-tailed Student's t test or ANOVA as appropriate. Rates of molecular alterations among the different groups were compared with Pearson's χ 2 . Two thousand five hundred fifty-two patients with PDAC were identified in a retrospective database, and the 15 most common molecular alterations were utilized for analysis. The most common alterations among all patients were mutations in KRAS and PTEN (59 and 62%, respectively), with differences in prevalence by site of metastasis (p = 0.042 and p = 0.037, respectively). KRAS mutations were more commonly found in metastasis in the lung (72%) than in other sites (59%, p = 0.042). Low expression of ERCC1 was found in 49% of lung metastases from PDAC but only 15% in PDAC in the pancreas (p molecular alterations significantly associated with site of metastatic disease were involved in DNA maintenance, repair, replication, or transcription (each p molecular alterations warrants further investigation.

  6. Coxsackievirus cloverleaf RNA containing a 5' triphosphate triggers an antiviral response via RIG-I activation

    NARCIS (Netherlands)

    Feng, Qian; Langereis, Martijn A; Olagnier, David; Chiang, Cindy; van de Winkel, Roel; van Essen, Peter; Zoll, Jan; Hiscott, John; van Kuppeveld, Frank J M

    2014-01-01

    Upon viral infections, pattern recognition receptors (PRRs) recognize pathogen-associated molecular patterns (PAMPs) and stimulate an antiviral state associated with the production of type I interferons (IFNs) and inflammatory markers. Type I IFNs play crucial roles in innate antiviral responses by

  7. Precision medicine for hepatocelluar carcinoma using molecular pattern diagnostics: results from a preclinical pilot study.

    Science.gov (United States)

    Agarwal, Rahul; Cao, Yuan; Hoffmeier, Klaus; Krezdorn, Nicolas; Jost, Lukas; Meisel, Alejandro Rodriguez; Jüngling, Ruth; Dituri, Francesco; Mancarella, Serena; Rotter, Björn; Winter, Peter; Giannelli, Gianluigi

    2017-06-08

    The aim of this study was to design a road map for personalizing cancer therapy in hepatocellular carcinoma (HCC) by using molecular pattern diagnostics. As an exploratory study, we investigated molecular patterns of tissues of two tumors from individual HCC patients, which in previous experiments had shown contrasting reactions to the phase 2 transforming growth factor beta receptor 1 inhibitor galunisertib. Cancer-driving molecular patterns encompass - inter alias - altered transcription profiles and somatic mutations in coding regions differentiating tumors from their respective peritumoral tissues and from each other. Massive analysis of cDNA ends and all-exome sequencing demonstrate a highly divergent transcriptional and mutational landscape, respectively, for the two tumors, that offers potential explanations for the tumors contrasting responses to galunisertib. Molecular pattern diagnostics (MPDs) suggest alternative, individual-tumor-specific therapies, which in both cases deviate from the standard sorafenib treatment and from each other. Suggested personalized therapies use kinase inhibitors and immune-focused drugs as well as low-toxicity natural compounds identified using an advanced bioinformatics routine included in the MPD protocol. The MPD pipeline we describe here for the prediction of suitable drugs for treatment of two contrasting HCCs may serve as a blueprint for the design of therapies for various types of cancer.

  8. Salmonella Pathogenicity and Host Adaptation in Chicken-Associated Serovars

    Science.gov (United States)

    Johnson, Timothy J.; Ricke, Steven C.; Nayak, Rajesh; Danzeisen, Jessica

    2013-01-01

    SUMMARY Enteric pathogens such as Salmonella enterica cause significant morbidity and mortality. S. enterica serovars are a diverse group of pathogens that have evolved to survive in a wide range of environments and across multiple hosts. S. enterica serovars such as S. Typhi, S. Dublin, and S. Gallinarum have a restricted host range, in which they are typically associated with one or a few host species, while S. Enteritidis and S. Typhimurium have broad host ranges. This review examines how S. enterica has evolved through adaptation to different host environments, especially as related to the chicken host, and continues to be an important human pathogen. Several factors impact host range, and these include the acquisition of genes via horizontal gene transfer with plasmids, transposons, and phages, which can potentially expand host range, and the loss of genes or their function, which would reduce the range of hosts that the organism can infect. S. Gallinarum, with a limited host range, has a large number of pseudogenes in its genome compared to broader-host-range serovars. S. enterica serovars such as S. Kentucky and S. Heidelberg also often have plasmids that may help them colonize poultry more efficiently. The ability to colonize different hosts also involves interactions with the host's immune system and commensal organisms that are present. Thus, the factors that impact the ability of Salmonella to colonize a particular host species, such as chickens, are complex and multifactorial, involving the host, the pathogen, and extrinsic pressures. It is the interplay of these factors which leads to the differences in host ranges that we observe today. PMID:24296573

  9. Identification of membrane-associated proteins with pathogenic potential expressed by Corynebacterium pseudotuberculosis grown in animal serum.

    Science.gov (United States)

    Raynal, José Tadeu; Bastos, Bruno Lopes; Vilas-Boas, Priscilla Carolinne Bagano; Sousa, Thiago de Jesus; Costa-Silva, Marcos; de Sá, Maria da Conceição Aquino; Portela, Ricardo Wagner; Moura-Costa, Lília Ferreira; Azevedo, Vasco; Meyer, Roberto

    2018-01-25

    Previous works defining antigens that might be used as vaccine targets against Corynebacterium pseudotuberculosis, which is the causative agent of sheep and goat caseous lymphadenitis, have focused on secreted proteins produced in a chemically defined culture media. Considering that such antigens might not reflect the repertoire of proteins expressed during infection conditions, this experiment aimed to investigate the membrane-associated proteins with pathogenic potential expressed by C. pseudotuberculosis grown directly in animal serum. Its membrane-associated proteins have been extracted using an organic solvent enrichment methodology, followed by LC-MS/MS and bioinformatics analysis for protein identification and classification. The results revealed 22 membrane-associated proteins characterized as potentially pathogenic. An interaction network analysis indicated that the four potentially pathogenic proteins ciuA, fagA, OppA4 and OppCD were biologically connected within two distinct network pathways, which were both associated with the ABC Transporters KEGG pathway. These results suggest that C. pseudotuberculosis pathogenesis might be associated with the transport and uptake of nutrients; other seven identified potentially pathogenic membrane proteins also suggest that pathogenesis might involve events of bacterial resistance and adhesion. The proteins herein reported potentially reflect part of the protein repertoire expressed during real infection conditions and might be tested as vaccine antigens.

  10. HIV-TRACE (Transmission Cluster Engine): a tool for large scale molecular epidemiology of HIV-1 and other rapidly evolving pathogens.

    Science.gov (United States)

    Kosakovsky Pond, Sergei L; Weaver, Steven; Leigh Brown, Andrew J; Wertheim, Joel O

    2018-01-31

    In modern applications of molecular epidemiology, genetic sequence data are routinely used to identify clusters of transmission in rapidly evolving pathogens, most notably HIV-1. Traditional 'shoeleather' epidemiology infers transmission clusters by tracing chains of partners sharing epidemiological connections (e.g., sexual contact). Here, we present a computational tool for identifying a molecular transmission analog of such clusters: HIV-TRACE (TRAnsmission Cluster Engine). HIV-TRACE implements an approach inspired by traditional epidemiology, by identifying chains of partners whose viral genetic relatedness imply direct or indirect epidemiological connections. Molecular transmission clusters are constructed using codon-aware pairwise alignment to a reference sequence followed by pairwise genetic distance estimation among all sequences. This approach is computationally tractable and is capable of identifying HIV-1 transmission clusters in large surveillance databases comprising tens or hundreds of thousands of sequences in near real time, i.e., on the order of minutes to hours. HIV-TRACE is available at www.hivtrace.org and from github.com/veg/hivtrace, along with the accompanying result visualization module from github.com/veg/hivtrace-viz. Importantly, the approach underlying HIV-TRACE is not limited to the study of HIV-1 and can be applied to study outbreaks and epidemics of other rapidly evolving pathogens. © The Author 2018. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Plant innate immunity against human bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Maeli eMelotto

    2014-08-01

    Full Text Available Certain human bacterial pathogens such as the enterohemorrhagic Escherichia coli and Salmonella enterica are not proven to be plant pathogens yet. Nonetheless, under certain conditions they can survive on, penetrate into, and colonize internal plant tissues causing serious food borne disease outbreaks. In this review, we highlight current understanding on the molecular mechanisms of plant responses against human bacterial pathogens and discuss salient common and contrasting themes of plant interactions with phytopathogens or human pathogens.

  12. Highly pathogenic avian influenza virus subtype H5N1 in Africa: a comprehensive phylogenetic analysis and molecular characterization of isolates.

    Directory of Open Access Journals (Sweden)

    Giovanni Cattoli

    Full Text Available Highly pathogenic avian influenza virus A/H5N1 was first officially reported in Africa in early 2006. Since the first outbreak in Nigeria, this virus spread rapidly to other African countries. From its emergence to early 2008, 11 African countries experienced A/H5N1 outbreaks in poultry and human cases were also reported in three of these countries. At present, little is known of the epidemiology and molecular evolution of A/H5N1 viruses in Africa. We have generated 494 full gene sequences from 67 African isolates and applied molecular analysis tools to a total of 1,152 A/H5N1 sequences obtained from viruses isolated in Africa, Europe and the Middle East between 2006 and early 2008. Detailed phylogenetic analyses of the 8 gene viral segments confirmed that 3 distinct sublineages were introduced, which have persisted and spread across the continent over this 2-year period. Additionally, our molecular epidemiological studies highlighted the association between genetic clustering and area of origin in a majority of cases. Molecular signatures unique to strains isolated in selected areas also gave us a clearer picture of the spread of A/H5N1 viruses across the continent. Mutations described as typical of human influenza viruses in the genes coding for internal proteins or associated with host adaptation and increased resistance to antiviral drugs have also been detected in the genes coding for transmembrane proteins. These findings raise concern for the possible human health risk presented by viruses with these genetic properties and highlight the need for increased efforts to monitor the evolution of A/H5N1 viruses across the African continent. They further stress how imperative it is to implement sustainable control strategies to improve animal and public health at a global level.

  13. Morphological and molecular characterization, sexual reproduction, and pathogenicity of Setosphaeria rostrata isolates from rice leaf spot.

    Science.gov (United States)

    Kusai, Nor Azizah; Azmi, Madihah Mior Zakuan; Zainudin, Nur Ain Izzati Mohd; Yusof, Mohd Termizi; Razak, Azmi Abd

    2016-09-01

    Setosphaeria rostrata, a common plant pathogen causing leaf spot disease, affects a wide range of plant species, mainly grasses. Fungi were isolated from brown spots on rice leaves throughout Peninsular Malaysia, and 45 isolates were identified as Setosphaeria rostrata The isolates were then characterized using morphological and molecular approaches. The mating type was determined using PCR amplification of the mating type alleles, and isolates of opposite mating types were crossed to examine sexual reproduction. Based on nuclear ribosomal DNA ITS1-5.8S-ITS2 region (ITS) and beta-tubulin (BT2) sequences, two phylogenetic trees were constructed using the maximum likelihood method; S. rostrata was clustered in one well-supported clade. Pathogenicity tests showed that S. rostrata isolates are pathogenic, suggesting that it is the cause of the symptoms. Mating-type analyses indicated that three isolates carried the MAT1-1 allele, and the other 42 isolates carried MAT1-2 After isolates with opposite mating types were crossed on Sach's medium and incubated for 3 wk, six crosses produced pseudothecia that contained eight mature ascospores, and 12 other crosses produced numerous pseudothecia with no ascospores. To our knowledge, this is the first report on S. rostrata isolated from leaf spots on rice. © 2016 by The Mycological Society of America.

  14. Associations between pathogens in the upper respiratory tract of young children: interplay between viruses and bacteria.

    Directory of Open Access Journals (Sweden)

    Menno R van den Bergh

    Full Text Available High rates of potentially pathogenic bacteria and respiratory viruses can be detected in the upper respiratory tract of healthy children. Investigating presence of and associations between these pathogens in healthy individuals is still a rather unexplored field of research, but may have implications for interpreting findings during disease.We selected 986 nasopharyngeal samples from 433 6- to 24-month-old healthy children that had participated in a randomized controlled trial. We determined the presence of 20 common respiratory viruses using real-time PCR. Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus were identified by conventional culture methods. Information on risk factors was obtained by questionnaires. We performed multivariate logistic regression analyses followed by partial correlation analysis to identify the overall pattern of associations. S. pneumoniae colonization was positively associated with the presence of H. influenzae (adjusted odds ratio 1.60, 95% confidence interval 1.18-2.16, M. catarrhalis (1.78, 1.29-2.47, human rhinoviruses (1.63, 1.19-2.22 and enteroviruses (1.97, 1.26-3.10, and negatively associated with S. aureus presence (0.59, 0.35-0.98. H. influenzae was positively associated with human rhinoviruses (1.63, 1.22-2.18 and respiratory syncytial viruses (2.78, 1.06-7.28. M. catarrhalis colonization was positively associated with coronaviruses (1.99, 1.01-3.93 and adenoviruses (3.69, 1.29-10.56, and negatively with S. aureus carriage (0.42, 0.25-0.69. We observed a strong positive association between S. aureus and influenza viruses (4.87, 1.59-14.89. In addition, human rhinoviruses and enteroviruses were positively correlated (2.40, 1.66-3.47, as were enteroviruses and human bocavirus, WU polyomavirus, parainfluenza viruses, and human parechovirus. A negative association was observed between human rhinoviruses and coronaviruses.Our data revealed high viral and

  15. Increased expression of damage-associated molecular patterns (DAMPs) in osteoarthritis of human knee joint compared to hip joint.

    Science.gov (United States)

    Rosenberg, John H; Rai, Vikrant; Dilisio, Matthew F; Sekundiak, Todd D; Agrawal, Devendra K

    2017-12-01

    Osteoarthritis (OA) is a degenerative disease characterized by the destruction of cartilage. The greatest risk factors for the development of OA include age and obesity. Recent studies suggest the role of inflammation in the pathogenesis of OA. The two most common locations for OA to occur are in the knee and hip joints. The knee joint experiences more mechanical stress, cartilage degeneration, and inflammation than the hip joint. This could contribute to the increased incidence of OA in the knee joint. Damage-associated molecular patterns (DAMPs), including high-mobility group box-1, receptor for advanced glycation end products, and alarmins (S100A8 and S100A9), are released in the joint in response to stress-mediated chondrocyte and cartilage damage. This facilitates increased cartilage degradation and inflammation in the joint. Studies have documented the role of DAMPs in the pathogenesis of OA; however, the comparison of DAMPs and its influence on OA has not been discussed. In this study, we compared the DAMPs between OA knee and hip joints and found a significant difference in the levels of DAMPs expressed in the knee joint compared to the hip joint. The increased levels of DAMPs suggest a difference in the underlying pathogenesis of OA in the knee and the hip and highlights DAMPs as potential therapeutic targets for OA in the future.

  16. Contrasted evolutionary histories of two Toll-like receptors (Tlr4 and Tlr7) in wild rodents (MURINAE)

    Czech Academy of Sciences Publication Activity Database

    Fornůsková, Alena; Vinkler, M.; Pages, M.; Galan, M.; Jousselin, E.; Cerqueira, F.; Morand, S.; Charbonnel, N.; Bryja, Josef; Cosson, J.-F.

    2013-01-01

    Roč. 13, č. 194 (2013), s. 194 ISSN 1471-2148 R&D Projects : GA ČR GA206/08/0640 Institutional support: RVO:68081766 Keywords : Arms race * Host-pathogen interaction * Pattern recognition receptors * Adaptive evolution * Pathogen-Associated Molecular Pattern (PAMP) Subject RIV: EG - Zoology Impact factor: 3.407, year: 2013 http://www.biomedcentral.com/1471-2148/13/194

  17. Enteric Pathogen-Plant Interactions: Molecular Connections Leading to Colonization and Growth and Implications for Food Safety

    OpenAIRE

    Martínez-Vaz, Betsy M.; Fink, Ryan C.; Diez-Gonzalez, Francisco; Sadowsky, Michael J.

    2014-01-01

    Leafy green vegetables have been identified as a source of foodborne illnesses worldwide over the past decade. Human enteric pathogens, such as Escherichia coli O157:H7 and Salmonella, have been implicated in numerous food poisoning outbreaks associated with the consumption of fresh produce. An understanding of the mechanisms responsible for the establishment of pathogenic bacteria in or on vegetable plants is critical for understanding and ameliorating this problem as well as ensuring the sa...

  18. Enhanced molecular aging in late-life depression: the Senescent Associated Secretory Phenotype

    Science.gov (United States)

    Diniz, Breno Satler; Reynolds, Charles F.; Sibille, Etienne; Lin, Chien-Wei; Tseng, George; Lotrich, Francis; Aizenstein, Howard J.; Butters, Meryl A.

    2016-01-01

    Objective This study aims to investigate whether a systemic molecular pattern associated with aging (senescent-associated secretory phenotype – SASP) is elevated in adults with late-life depression (LLD), compared to never-depressed elderly comparison participants. Design Cross-sectional study. Participants We included 111 older adults (80 with LLD and 31 comparison participants) in this study. Measurement A panel of 22 SASP-related proteins was extracted from a previous multiplex protein panel performed in these participants. We conducted a principal component analysis to create the SASP index based on individual weights of each of protein. Results Participants with LLD showed a significantly increased SASP index compared to comparison participants, after controlling for age, depressive symptoms, medical comorbidity (CIRS-G) scores, gender, and cognitive performance (F(1,98)=7.3, p=0.008). Correlation analyses revealed that the SASP index was positively correlated with age (r=0.2, p = 0.03) and CIRS score (r=0.27, p=0.005), and negatively correlated with information processing speed (r=−0.34, p=0.001), executive function (r=−0.27, p=0.004) and global cognitive performance (r=−0.28, p=0.007). Conclusions To the best of our knowledge, this is the first study to show that a set of proteins (i.e., SASP index) primarily associated with cellular aging, is abnormally regulated and elevated in LLD. These results suggest that individuals with LLD display enhanced aging-related molecular patterns that are associated with higher medical comorbidity and worse cognitive function. Finally, we provide a set of proteins that can serve as potential therapeutic targets and biomarkers to monitor the effects of therapeutic or preventative interventions in LLD. PMID:27856124

  19. Application of FTA technology for sampling, recovery and molecular characterization of viral pathogens and virus-derived transgenes from plant tissues

    Science.gov (United States)

    Ndunguru, Joseph; Taylor, Nigel J; Yadav, Jitender; Aly, Haytham; Legg, James P; Aveling, Terry; Thompson, Graham; Fauquet, Claude M

    2005-01-01

    Background Plant viral diseases present major constraints to crop production. Effective sampling of the viruses infecting plants is required to facilitate their molecular study and is essential for the development of crop protection and improvement programs. Retaining integrity of viral pathogens within sampled plant tissues is often a limiting factor in this process, most especially when sample sizes are large and when operating in developing counties and regions remote from laboratory facilities. FTA is a paper-based system designed to fix and store nucleic acids directly from fresh tissues pressed into the treated paper. We report here the use of FTA as an effective technology for sampling and retrieval of DNA and RNA viruses from plant tissues and their subsequent molecular analysis. Results DNA and RNA viruses were successfully recovered from leaf tissues of maize, cassava, tomato and tobacco pressed into FTA® Classic Cards. Viral nucleic acids eluted from FTA cards were found to be suitable for diagnostic molecular analysis by PCR-based techniques and restriction analysis, and for cloning and nucleotide sequencing in a manner equivalent to that offered by tradition isolation methods. Efficacy of the technology was demonstrated both from sampled greenhouse-grown plants and from leaf presses taken from crop plants growing in farmer's fields in East Africa. In addition, FTA technology was shown to be suitable for recovery of viral-derived transgene sequences integrated into the plant genome. Conclusion Results demonstrate that FTA is a practical, economical and sensitive method for sampling, storage and retrieval of viral pathogens and plant genomic sequences, when working under controlled conditions and in the field. Application of this technology has the potential to significantly increase ability to bring modern analytical techniques to bear on the viral pathogens infecting crop plants. PMID:15904535

  20. Application of FTA technology for sampling, recovery and molecular characterization of viral pathogens and virus-derived transgenes from plant tissues.

    Science.gov (United States)

    Ndunguru, Joseph; Taylor, Nigel J; Yadav, Jitender; Aly, Haytham; Legg, James P; Aveling, Terry; Thompson, Graham; Fauquet, Claude M

    2005-05-18

    Plant viral diseases present major constraints to crop production. Effective sampling of the viruses infecting plants is required to facilitate their molecular study and is essential for the development of crop protection and improvement programs. Retaining integrity of viral pathogens within sampled plant tissues is often a limiting factor in this process, most especially when sample sizes are large and when operating in developing counties and regions remote from laboratory facilities. FTA is a paper-based system designed to fix and store nucleic acids directly from fresh tissues pressed into the treated paper. We report here the use of FTA as an effective technology for sampling and retrieval of DNA and RNA viruses from plant tissues and their subsequent molecular analysis. DNA and RNA viruses were successfully recovered from leaf tissues of maize, cassava, tomato and tobacco pressed into FTA Classic Cards. Viral nucleic acids eluted from FTA cards were found to be suitable for diagnostic molecular analysis by PCR-based techniques and restriction analysis, and for cloning and nucleotide sequencing in a manner equivalent to that offered by tradition isolation methods. Efficacy of the technology was demonstrated both from sampled greenhouse-grown plants and from leaf presses taken from crop plants growing in farmer's fields in East Africa. In addition, FTA technology was shown to be suitable for recovery of viral-derived transgene sequences integrated into the plant genome. Results demonstrate that FTA is a practical, economical and sensitive method for sampling, storage and retrieval of viral pathogens and plant genomic sequences, when working under controlled conditions and in the field. Application of this technology has the potential to significantly increase ability to bring modern analytical techniques to bear on the viral pathogens infecting crop plants.

  1. Application of FTA technology for sampling, recovery and molecular characterization of viral pathogens and virus-derived transgenes from plant tissues

    Directory of Open Access Journals (Sweden)

    Aveling Terry

    2005-05-01

    Full Text Available Abstract Background Plant viral diseases present major constraints to crop production. Effective sampling of the viruses infecting plants is required to facilitate their molecular study and is essential for the development of crop protection and improvement programs. Retaining integrity of viral pathogens within sampled plant tissues is often a limiting factor in this process, most especially when sample sizes are large and when operating in developing counties and regions remote from laboratory facilities. FTA is a paper-based system designed to fix and store nucleic acids directly from fresh tissues pressed into the treated paper. We report here the use of FTA as an effective technology for sampling and retrieval of DNA and RNA viruses from plant tissues and their subsequent molecular analysis. Results DNA and RNA viruses were successfully recovered from leaf tissues of maize, cassava, tomato and tobacco pressed into FTA® Classic Cards. Viral nucleic acids eluted from FTA cards were found to be suitable for diagnostic molecular analysis by PCR-based techniques and restriction analysis, and for cloning and nucleotide sequencing in a manner equivalent to that offered by tradition isolation methods. Efficacy of the technology was demonstrated both from sampled greenhouse-grown plants and from leaf presses taken from crop plants growing in farmer's fields in East Africa. In addition, FTA technology was shown to be suitable for recovery of viral-derived transgene sequences integrated into the plant genome. Conclusion Results demonstrate that FTA is a practical, economical and sensitive method for sampling, storage and retrieval of viral pathogens and plant genomic sequences, when working under controlled conditions and in the field. Application of this technology has the potential to significantly increase ability to bring modern analytical techniques to bear on the viral pathogens infecting crop plants.

  2. Functional Redundancy and Ecological Innovation Shape the Circulation of Tick-Transmitted Pathogens

    Directory of Open Access Journals (Sweden)

    Agustín Estrada-Peña

    2017-05-01

    Full Text Available Ticks are vectors of pathogens affecting human and animal health worldwide. Nevertheless, the ecological and evolutionary interactions between ticks, hosts, and pathogens are largely unknown. Here, we integrated a framework to evaluate the associations of the tick Ixodes ricinus with its hosts and environmental niches that impact pathogen circulation. The analysis of tick-hosts association suggested that mammals and lizards were the ancestral hosts of this tick species, and that a leap to Aves occurred around 120 M years ago. The signature of the environmental variables over the host's phylogeny revealed the existence of two clades of vertebrates diverging along a temperature and vegetation split. This is a robust proof that the tick probably experienced a colonization of new niches by adapting to a large set of new hosts, Aves. Interestingly, the colonization of Aves as hosts did not increase significantly the ecological niche of I. ricinus, but remarkably Aves are super-spreaders of pathogens. The disparate contribution of Aves to the tick-host-pathogen networks revealed that I. ricinus evolved to maximize habitat overlap with some hosts that are super-spreaders of pathogens. These results supported the hypothesis that large host networks are not a requirement of tick survival but pathogen circulation. The biological cost of tick adaptation to non-optimal environmental conditions might be balanced by molecular mechanisms triggered by the pathogens that we have only begun to understand.

  3. Accommodating error analysis in comparison and clustering of molecular fingerprints.

    OpenAIRE

    Salamon, H.; Segal, M. R.; Ponce de Leon, A.; Small, P. M.

    1998-01-01

    Molecular epidemiologic studies of infectious diseases rely on pathogen genotype comparisons, which usually yield patterns comprising sets of DNA fragments (DNA fingerprints). We use a highly developed genotyping system, IS6110-based restriction fragment length polymorphism analysis of Mycobacterium tuberculosis, to develop a computational method that automates comparison of large numbers of fingerprints. Because error in fragment length measurements is proportional to fragment length and is ...

  4. Molecular and Functional Characterization of Mouse S5D-SRCRB: A New Group B Member of the Scavenger Receptor Cysteine-Rich Superfamily

    DEFF Research Database (Denmark)

    Miró-Julià, Cristina; Roselló, Sandra; Martínez, Vanesa G

    2011-01-01

    The scavenger receptor cysteine-rich superfamily (SRCR-SF) members are transmembrane and/or secreted receptors exhibiting one or several repeats of a cysteine-rich protein module of ∼100 aa, named scavenger receptor cysteine-rich (SRCR). Two types of SRCR domains (A or B) have been reported, which...... differ in the number of coding exons and intradomain cysteines. Although no unifying function has been reported for SRCR-SF members, recognition of pathogen-associated molecular patterns (PAMPs) was recently shown for some of them. In this article, we report the structural and functional characterization...

  5. Dyslipidemia patterns are differentially associated with dietary factors.

    Science.gov (United States)

    Song, SuJin; Paik, Hee Young; Park, Minseon; Song, YoonJu

    2016-08-01

    Dyslipidemia, a strong predictor of cardiovascular diseases, is prevalent among Korean adults, but little is known about the associations between overall lipid profiles and dietary factors. We identified dyslipidemia patterns among lipid indicators and examined dietary factors associated with dyslipidemia patterns in Korean adults. Subjects in this cross-sectional study were recruited from the Family Medicine Division or the Health Examination Center of the general hospital in Seoul between 2010 and 2012. Measurements of biochemical and dietary variables repeated three times were collected from a total of 138 subjects at 3- to 4-month intervals when the subjects visited the hospital. Dietary intake data were obtained using 24-h recalls. In order to estimate typical values for biochemical and dietary variables, the averages of repeated measures for each subject were calculated. To identify dyslipidemia patterns, factor analysis was used based on total cholesterol (TC), low-density lipoprotein cholesterol (LDLC), triglycerides (TG), and high-density lipoprotein cholesterol (HDLC). Two dyslipidemia patterns, (1) TC & LDLC and (2) TG & HDLC, were identified. Dietary fat and cholesterol intakes were positively associated with the TC & LDLC pattern score, but not associated with the TG & HDLC pattern score. The TG & HDLC pattern was significantly associated with low intakes of calcium, potassium, milk and dairy products. Two dyslipidemia patterns were associated with dietary factors in Korean adults. Further studies should investigate specific dietary recommendations according to lipid profiles in the prevention and management of dyslipidemia in Korea. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  6. Rhizosphere-associated Pseudomonas induce systemic resistance to herbivores at the cost of susceptibility to bacterial pathogens.

    Science.gov (United States)

    Haney, Cara H; Wiesmann, Christina L; Shapiro, Lori R; Melnyk, Ryan A; O'Sullivan, Lucy R; Khorasani, Sophie; Xiao, Li; Han, Jiatong; Bush, Jenifer; Carrillo, Juli; Pierce, Naomi E; Ausubel, Frederick M

    2017-10-31

    Plant-associated soil microbes are important mediators of plant defence responses to diverse above-ground pathogen and insect challengers. For example, closely related strains of beneficial rhizosphere Pseudomonas spp. can induce systemic resistance (ISR), systemic susceptibility (ISS) or neither against the bacterial foliar pathogen Pseudomonas syringae pv. tomato DC3000 (Pto DC3000). Using a model system composed of root-associated Pseudomonas spp. strains, the foliar pathogen Pto DC3000 and the herbivore Trichoplusia ni (cabbage looper), we found that rhizosphere-associated Pseudomonas spp. that induce either ISS and ISR against Pto DC3000 all increased resistance to herbivory by T. ni. We found that resistance to T. ni and resistance to Pto DC3000 are quantitative metrics of the jasmonic acid (JA)/salicylic acid (SA) trade-off and distinct strains of rhizosphere-associated Pseudomonas spp. have distinct effects on the JA/SA trade-off. Using genetic analysis and transcriptional profiling, we provide evidence that treatment of Arabidopsis with Pseudomonas sp. CH267, which induces ISS against bacterial pathogens, tips the JA/SA trade-off towards JA-dependent defences against herbivores at the cost of a subset of SA-mediated defences against bacterial pathogens. In contrast, treatment of Arabidopsis with the ISR strain Pseudomonas sp. WCS417 disrupts JA/SA antagonism and simultaneously primes plants for both JA- and SA-mediated defences. Our findings show that ISS against the bacterial foliar pathogens triggered by Pseudomonas sp. CH267, which is a seemingly deleterious phenotype, may in fact be an adaptive consequence of increased resistance to herbivory. Our work shows that pleiotropic effects of microbiome modulation of plant defences are important to consider when using microbes to modify plant traits in agriculture. © 2017 John Wiley & Sons Ltd.

  7. Helicase-dependent isothermal amplification: a novel tool in the development of molecular-based analytical systems for rapid pathogen detection.

    Science.gov (United States)

    Barreda-García, Susana; Miranda-Castro, Rebeca; de-Los-Santos-Álvarez, Noemí; Miranda-Ordieres, Arturo J; Lobo-Castañón, María Jesús

    2018-01-01

    Highly sensitive testing of nucleic acids is essential to improve the detection of pathogens, which pose a major threat for public health worldwide. Currently available molecular assays, mainly based on PCR, have a limited utility in point-of-need control or resource-limited settings. Consequently, there is a strong interest in developing cost-effective, robust, and portable platforms for early detection of these harmful microorganisms. Since its description in 2004, isothermal helicase-dependent amplification (HDA) has been successfully applied in the development of novel molecular-based technologies for rapid, sensitive, and selective detection of viruses and bacteria. In this review, we highlight relevant analytical systems using this simple nucleic acid amplification methodology that takes place at a constant temperature and that is readily compatible with microfluidic technologies. Different strategies for monitoring HDA amplification products are described. In addition, we present technological advances for integrating sample preparation, HDA amplification, and detection. Future perspectives and challenges toward point-of-need use not only for clinical diagnosis but also in food safety testing and environmental monitoring are also discussed. Graphical Abstract Expanding the analytical toolbox for the detection of DNA sequences specific of pathogens with isothermal helicase dependent amplification (HDA).

  8. Prevalence And Antimicrobial Susceptibility Pattern Of Methicillin ...

    African Journals Online (AJOL)

    Methicillin resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen. We report the prevalence and antibiotic susceptibility pattern of MRSA in Amravati, Maharashtra state (India). A total of 150 healthcare-associated (HA) sources (doctors mobiles phone and wound/pus swabs), and 160 ...

  9. Molecular and serological detection of tick-borne pathogens in dogs from an area endemic for Leishmania infantumin Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Keyla Carstens Marques de Sousa

    Full Text Available Tick-borne pathogens affect a wide range of vertebrate hosts. To identify tick-borne pathogens among dogs from Campo Grande, MS, Brazil testing seropositive for Leishmania infantum (syn. L. chagasi, a serological and molecular study was conducted to detectEhrlichia canis, Anaplasma platys and Babesia vogeli in 60 serum and spleen samples. A confirmatory diagnosis ofL. infantum based on serological and molecular assays was also performed, as was sequence alignment and phylogenetic analysis to assess the identity of the parasite species infecting these animals. IgG antibodies toEhrlichia spp., B. vogeli and L. infantum were found, respectively, in 39 (65%, 49 (81.6% and 60 (100% of the sampled dogs. Twenty-seven (45%, fifty-four (90%, fifty-three (88.3%, two (3.3% and one (1.6% dog were positive, respectively, forE. canis, Leishmania spp., Leishmania donovani complex, Babesia sp. and Anaplasma sp. in PCR assays. After sequencing, the amplicons showed 99% of identity with E. canis, B. vogeli, A. platys andLeishmania chagasi isolates. The findings of this study indicate that L. infantum-seropositive dogs from Campo Grande are exposed to multiple tick-borne pathogens, which should therefore be included in the differential diagnosis of dogs with clinical suspicion of leishmaniasis.

  10. Spiers Memorial Lecture. Molecular mechanics and molecular electronics.

    Science.gov (United States)

    Beckman, Robert; Beverly, Kris; Boukai, Akram; Bunimovich, Yuri; Choi, Jang Wook; DeIonno, Erica; Green, Johnny; Johnston-Halperin, Ezekiel; Luo, Yi; Sheriff, Bonnie; Stoddart, Fraser; Heath, James R

    2006-01-01

    We describe our research into building integrated molecular electronics circuitry for a diverse set of functions, and with a focus on the fundamental scientific issues that surround this project. In particular, we discuss experiments aimed at understanding the function of bistable rotaxane molecular electronic switches by correlating the switching kinetics and ground state thermodynamic properties of those switches in various environments, ranging from the solution phase to a Langmuir monolayer of the switching molecules sandwiched between two electrodes. We discuss various devices, low bit-density memory circuits, and ultra-high density memory circuits that utilize the electrochemical switching characteristics of these molecules in conjunction with novel patterning methods. We also discuss interconnect schemes that are capable of bridging the micrometre to submicrometre length scales of conventional patterning approaches to the near-molecular length scales of the ultra-dense memory circuits. Finally, we discuss some of the challenges associated with fabricated ultra-dense molecular electronic integrated circuits.

  11. Integrating large-scale data and RNA technology to protect crops from fungal pathogens

    Directory of Open Access Journals (Sweden)

    Ian Joseph Girard

    2016-05-01

    Full Text Available With a rapidly growing human population it is expected that plant science researchers and the agricultural community will need to increase food productivity using less arable land. This challenge is complicated by fungal pathogens and diseases, many of which can severely impact crop yield. Current measures to control fungal pathogens are either ineffective or have adverse effects on the agricultural enterprise. Thus, developing new strategies through research innovation to protect plants from pathogenic fungi is necessary to overcome these hurdles. RNA sequencing technologies are increasing our understanding of the underlying genes and gene regulatory networks mediating disease outcomes. The application of invigorating next generation sequencing strategies to study plant-pathogen interactions has and will provide unprecedented insight into the complex patterns of gene activity responsible for crop protection. However, questions remain about how biological processes in both the pathogen and the host are specified in space directly at the site of infection and over the infection period. The integration of cutting edge molecular and computational tools will provide plant scientists with the arsenal required to identify genes and molecules that play a role in plant protection. Large scale RNA sequence data can then be used to protect plants by targeting genes essential for pathogen viability in the production of stably transformed lines expressing RNA interference molecules, or through foliar applications of double stranded RNA.

  12. Molecular mechanisms of cell-cell spread of intracellular bacterial pathogens.

    Science.gov (United States)

    Ireton, Keith

    2013-07-17

    Several bacterial pathogens, including Listeria monocytogenes, Shigella flexneri and Rickettsia spp., have evolved mechanisms to actively spread within human tissues. Spreading is initiated by the pathogen-induced recruitment of host filamentous (F)-actin. F-actin forms a tail behind the microbe, propelling it through the cytoplasm. The motile pathogen then encounters the host plasma membrane, forming a bacterium-containing protrusion that is engulfed by an adjacent cell. Over the past two decades, much progress has been made in elucidating mechanisms of F-actin tail formation. Listeria and Shigella produce tails of branched actin filaments by subverting the host Arp2/3 complex. By contrast, Rickettsia forms tails with linear actin filaments through a bacterial mimic of eukaryotic formins. Compared with F-actin tail formation, mechanisms controlling bacterial protrusions are less well understood. However, recent findings have highlighted the importance of pathogen manipulation of host cell-cell junctions in spread. Listeria produces a soluble protein that enhances bacterial protrusions by perturbing tight junctions. Shigella protrusions are engulfed through a clathrin-mediated pathway at 'tricellular junctions'--specialized membrane regions at the intersection of three epithelial cells. This review summarizes key past findings in pathogen spread, and focuses on recent developments in actin-based motility and the formation and internalization of bacterial protrusions.

  13. MPLEx: a method for simultaneous pathogen inactivation and extraction of samples for multi-omics profiling

    Energy Technology Data Exchange (ETDEWEB)

    Burnum-Johnson, Kristin E.; Kyle, Jennifer E.; Eisfeld, Amie J.; Casey, Cameron P.; Stratton, Kelly G.; Gonzalez, Juan F.; Habyarimana, Fabien; Negretti, Nicholas M.; Sims, Amy C.; Chauhan, Sadhana; Thackray, Larissa B.; Halfmann, Peter J.; Walters, Kevin B.; Kim, Young-Mo; Zink, Erika M.; Nicora, Carrie D.; Weitz, Karl K.; Webb-Robertson, Bobbie-Jo M.; Nakayasu, Ernesto S.; Ahmer, Brian; Konkel, Michael E.; Motin, Vladimir; Baric, Ralph S.; Diamond, Michael S.; Kawaoka, Yoshihiro; Waters, Katrina M.; Smith, Richard D.; Metz, Thomas O.

    2017-01-01

    The continued emergence and spread of infectious agents is of increasing concern due to increased population growth and the associated increased livestock production to meet food demands, increased urbanization and land-use changes, and greater travel. A systems biology approach to infectious disease research can significantly advance our understanding of host-pathogen relationships and facilitate the development of new therapies and vaccines. Molecular characterization of infectious samples outside of appropriate biosafety containment can only take place subsequent to pathogen inactivation. Herein, we describe a modified Folch extraction using chloroform/methanol that facilitates the molecular characterization of infectious samples by enabling simultaneous pathogen inactivation and extraction of proteins, metabolites, and lipids for subsequent mass spectrometry-based multi-omics measurements. This metabolite, protein and lipid extraction (MPLEx) method resulted in complete inactivation of bacterial and viral pathogens with exposed lipid membranes, including Yersinia pestis, Salmonella Typhimurium, and Campylobacter jejuni in pure culture, and Yersinia pestis, Campylobacter jejuni, West Nile, MERS-CoV, Ebola, and influenza H7N9 viruses in infection studies. Partial inactivation was observed for pathogens without exposed lipid membranes including 99.99% inactivation of community-associated methicillin-resistant Staphylococcus aureus, 99.6% and >99% inactivation of Clostridium difficile spores and vegetative cells, respectively, and 50% inactivation of adenovirus type 5. To demonstrate that MPLEx yields biomaterial of sufficient quality for subsequent multi-omics analyses, we highlight select proteomics, metabolomics and lipidomics data from human epithelial lung cells infected with wild-type and mutant forms of influenza H7N9. We believe that MPLEx will facilitate systems biology studies of infectious samples by enabling simultaneous pathogen inactivation and multi

  14. Spatiotemporal structure of molecular evolution of H5N1 highly pathogenic avian influenza viruses in Vietnam.

    Directory of Open Access Journals (Sweden)

    Margaret A Carrel

    2010-01-01

    Full Text Available Vietnam is one of the countries most affected by outbreaks of H5N1 highly pathogenic avian influenza viruses. First identified in Vietnam in poultry in 2001 and in humans in 2004, the virus has since caused 111 cases and 56 deaths in humans. In 2003/2004 H5N1 outbreaks, nearly the entire poultry population of Vietnam was culled. Our earlier study (Wan et al., 2008, PLoS ONE, 3(10: e3462 demonstrated that there have been at least six independent H5N1 introductions into Vietnam and there were nine newly emerged reassortants from 2001 to 2007 in Vietnam. H5N1 viruses in Vietnam cluster distinctly around Hanoi and Ho Chi Minh City. However, the nature of the relationship between genetic divergence and geographic patterns is still unclear.In this study, we hypothesized that genetic distances between H5N1 viruses in Vietnam are correlated with geographic distances, as the result of distinct population and environment patterns along Vietnam's long north to south longitudinal extent. Based on this hypothesis, we combined spatial statistical methods with genetic analytic techniques and explicitly used geographic space to explore genetic evolution of H5N1 highly pathogenic avian influenza viruses at the sub-national scale in Vietnam. Our dataset consisted of 125 influenza viruses (with whole genome sets isolated in Vietnam from 2003 to 2007. Our results document the significant effect of space and time on genetic evolution and the rise of two regional centers of genetic mixing by 2007. These findings give insight into processes underlying viral evolution and suggest that genetic differentiation is associated with the distance between concentrations of human and poultry populations around Hanoi and Ho Chi Minh City.The results show that genetic evolution of H5N1 viruses in Vietnamese domestic poultry is highly correlated with the location and spread of those viruses in geographic space. This correlation varies by scale, time, and gene, though a classic

  15. Herpesviruses dUTPases: A New Family of Pathogen-Associated Molecular Pattern (PAMP Proteins with Implications for Human Disease

    Directory of Open Access Journals (Sweden)

    Marshall V. Williams

    2016-12-01

    Full Text Available The human herpesviruses are ubiquitous viruses and have a prevalence of over 90% in the adult population. Following a primary infection they establish latency and can be reactivated over a person’s lifetime. While it is well accepted that human herpesviruses are implicated in numerous diseases ranging from dermatological and autoimmune disease to cancer, the role of lytic proteins in the pathophysiology of herpesvirus-associated diseases remains largely understudies. Only recently have we begun to appreciate the importance of lytic proteins produced during reactivation of the virus, in particular the deoxyuridine triphosphate nucleotidohydrolases (dUTPase, as key modulators of the host innate and adaptive immune responses. In this review, we provide evidence from animal and human studies of the Epstein–Barr virus as a prototype, supporting the notion that herpesviruses dUTPases are a family of proteins with unique immunoregulatory functions that can alter the inflammatory microenvironment and thus exacerbate the immune pathology of herpesvirus-related diseases including myalgic encephalomyelitis/chronic fatigue syndrome, autoimmune diseases, and cancer.

  16. Studies of the binding of ficolin-2 and ficolin-3 from the complement lectin pathway to Leptospira biflexa, Pasteurella pneumotropica and Diarrheagenic Escherichia coli

    DEFF Research Database (Denmark)

    Sahagún-Ruiz, Alfredo; Breda, Leandro Carvalho Dantas; Valencia, Mónica Marcela Castiblanco

    2015-01-01

    Ficolins recognize pathogen associated molecular patterns and activate the lectin pathway of complement system. However, our knowledge regarding pathogen recognition of human ficolins is still limited. We therefore set out to explore and investigate the possible interactions of the two main serum...

  17. MAP kinase cascades in Arabidopsis innate immunity

    DEFF Research Database (Denmark)

    Rasmussen, Magnus Wohlfahrt; Roux, Milena Edna; Petersen, Morten

    2012-01-01

    Plant mitogen-activated protein kinase (MAPK) cascades generally transduce extracellular stimuli into cellular responses. These stimuli include the perception of pathogen-associated molecular patterns (PAMPs) by host transmembrane pattern recognition receptors which trigger MAPK-dependent innate ...

  18. Web tools for molecular epidemiology of tuberculosis.

    Science.gov (United States)

    Shabbeer, Amina; Ozcaglar, Cagri; Yener, Bülent; Bennett, Kristin P

    2012-06-01

    In this study we explore publicly available web tools designed to use molecular epidemiological data to extract information that can be employed for the effective tracking and control of tuberculosis (TB). The application of molecular methods for the epidemiology of TB complement traditional approaches used in public health. DNA fingerprinting methods are now routinely employed in TB surveillance programs and are primarily used to detect recent transmissions and in outbreak investigations. Here we present web tools that facilitate systematic analysis of Mycobacterium tuberculosis complex (MTBC) genotype information and provide a view of the genetic diversity in the MTBC population. These tools help answer questions about the characteristics of MTBC strains, such as their pathogenicity, virulence, immunogenicity, transmissibility, drug-resistance profiles and host-pathogen associativity. They provide an integrated platform for researchers to use molecular epidemiological data to address current challenges in the understanding of TB dynamics and the characteristics of MTBC. Copyright © 2011. Published by Elsevier B.V.

  19. Pathogen-group specific association between CXCR1 polymorphisms and subclinical mastitis in dairy heifers.

    Science.gov (United States)

    Verbeke, Joren; Piepers, Sofie; Peelman, Luc; Van Poucke, Mario; De Vliegher, Sarne

    2012-08-01

    The chemokine (C-X-C motif) receptor 1 (CXCR1) gene encodes the homonymous receptor for interleukin 8 (IL8) on polymorphonuclear neutrophilic leucocytes (PMNL). Binding causes migration from blood to milk, activation and prolonged survival of PMNL, a crucial process in the innate immune defence of the bovine mammary gland against invading mastitis-causing pathogens. The main objective of this study was to screen the entire coding region of the CXCR1 gene for polymorphisms and to analyse their association with udder health of dairy heifers. One-hundred-and-forty Belgian Holstein heifers originating from 20 commercial dairy farms were genotyped by DNA sequencing. Detailed phenotypic data on udder health was available including quarter bacteriological culture results and somatic cell count (SCC) in early lactation and composite milk SCC during first lactation. In total, 16 polymorphisms (including 8 missense mutations) were detected. Polymorphism c.980A>G was associated with pathogen-group specific IMI: heifers with genotype AG were less likely to have an IMI due to major mastitis pathogens compared with heifers with genotype GG but did not have less IMI by coagulase-negative staphylococci, so-called minor pathogens. CXCR1 genotype was neither associated with quarter SCC in early lactation nor with composite SCC during lactation. Although mastitis susceptibility is influenced by many factors, some genetic polymorphisms potentially have major effects on udder health of heifers, as was shown here. These results trigger us to further study the relationship between CXCR1 polymorphisms and mastitis susceptibility in both observational and experimental trials.

  20. Functions and origin of plasmids in Erwinia species that are pathogenic to or epiphytically associated with pome fruit trees.

    Science.gov (United States)

    Llop, Pablo; Barbé, Silvia; López, María M

    The genus Erwinia includes plant-associated pathogenic and non-pathogenic species. Among them, all species pathogenic to pome fruit trees ( E. amylovora, E. pyrifoliae, E. piriflorinigrans, Erwinia sp. from Japan) cause similar symptoms, but differ in their degrees of aggressiveness, i.e. in symptoms, host range or both. The presence of plasmids of similar size, in the range of 30 kb, is a common characteristic that they possess. Besides, they share some genetic content with high homology in several genes associated with exopolysaccharide production and hence, with virulence, as well as in some other genes. Knowledge of the content of these plasmids and comparative genetic analyses may provide interesting new clues to understanding the origin and evolution of these pathogens and the level of symptoms they produce. Furthermore, genetic similarities observed among some of the plasmids (and genomes) from the above indicated pathogenic species and E. tasmaniensis or E. billingiae , which are epiphytic on the same hosts, may reveal associations that could expose the mechanisms of origin of pathogens. A summary of the current information on their plasmids and the relationships among them is presented here.

  1. Arabidopsis flower specific defense gene expression patterns affect resistance to pathogens

    KAUST Repository

    Ederli, Luisa

    2015-02-20

    We investigated whether the Arabidopsis flower evolved protective measures to increase reproductive success. Firstly, analyses of available transcriptome data show that the most highly expressed transcripts in the closed sepal (stage 12) are enriched in genes with roles in responses to chemical stimuli and cellular metabolic processes. At stage 15, there is enrichment in transcripts with a role in responses to biotic stimuli. Comparative analyses between the sepal and petal in the open flower mark an over-representation of transcripts with a role in responses to stress and catalytic activity. Secondly, the content of the biotic defense-associated phytohormone salicylic acid (SA) in sepals and petals is significantly higher than in leaves. To understand whether the high levels of stress responsive transcripts and the higher SA content affect defense, wild-type plants (Col-0) and transgenic plants defective in SA accumulation (nahG) were challenged with the biotrophic fungus Golovinomyces cichoracearum, the causal agent of powdery mildew, and the necrotrophic fungus Botrytis cinerea. NahG leaves were more sensitive than those of Col-0, suggesting that in leaves SA has a role in the defense against biotrophs. In contrast, sepals and petals of both genotypes were resistant to G. cichoracearum, indicating that in the flower, resistance to the biotrophic pathogen is not critically dependent on SA, but likely dependent on the up-regulation of stress-responsive genes. Since sepals and petals of both genotypes are equally susceptible to B. cinerea, we conclude that neither stress-response genes nor increased SA accumulation offers protection against the necrotrophic pathogen. These results are interpreted in the light of the distinctive role of the flower and we propose that in the early stages, the sepal may act as a chemical defense barrier of the developing reproductive structures against biotrophic pathogens.

  2. Molecular Identification and Epidemiological Features of Human Adenoviruses Associated with Acute Respiratory Infections in Hospitalized Children in Southern China, 2012-2013.

    Science.gov (United States)

    Chen, Yi; Liu, Fanghua; Wang, Changbing; Zhao, Mingqi; Deng, Li; Zhong, Jiayu; Zhang, Yingying; Ye, Jun; Jing, Shuping; Cheng, Zetao; Guan, Yongxin; Ma, Yi; Sun, Yuanyuan; Zhu, Bing; Zhang, Qiwei

    2016-01-01

    Acute respiratory infections (ARI) are the major worldwide health problem associated with high morbidity and mortality rates. Human adenovirus (HAdV) is one of the most common pathogens associated with viral ARI, and thus calls for specific diagnosis and better understanding of the epidemiology and clinical characteristics. Total 4,130 children with ARI requiring hospitalization from 2012 to 2013 were retrospectively studied. Throat swab specimens were collected from each patient. Fluorescence Quantitative PCR was performed to detect adenovirus as well as other common ARI-related pathogens. The seven HAdV hypervariable regions (HVRs) of the hexon gene from fifty-seven HAdVs-positive samples collected in the seasonal peaks were sequenced. Phylogenetic analysis of HVRs was also conducted to confirm the molecular types and genetic variation. In addition, epidemiological features and co-infection with other human respiratory pathogens were investigated and analyzed. Of 4,130 hospitalized pediatric patients tested, the positive rates of respiratory syncytial virus (RSV), Mycoplasma pneumoniae (MP), and HAdV were 13.7%, 13.2%, and 12.0%, respectively. The HAdV positive patients accounted for 7.9%, 17.2%, 17.5% and 10.7% in age groups infected with other respiratory pathogens (84/495, 17.0%). The most common co-infection pathogens with HAdV were MP (57.1%) and Human Bocavirus (HBoV) (16.7%). The majority of HAdV infected patients were totally recovered (96.9%, 480/495); However, four (0.8%) patients, who were previously healthy and at the age of 2 years or younger died of pneumonia. Seasonal peaks of HAdV infection occurred in the summer season of 2012 and 2013; the predominant HAdV type was HAdV-3 (70%), followed by HAdV-7 (28%). These epidemiological features were different from those in Northern China. The HAdV-55 was identified and reported for the first time in Guangzhou metropolitan area. Phylogenetic analysis indicated that all the HVR sequences of the hexon gene

  3. Phylogeographic Diversity of Pathogenic and Non-Pathogenic Hantaviruses in Slovenia

    Science.gov (United States)

    Korva, Miša; Knap, Nataša; Resman Rus, Katarina; Fajs, Luka; Grubelnik, Gašper; Bremec, Matejka; Knapič, Tea; Trilar, Tomi; Avšič Županc, Tatjana

    2013-01-01

    Slovenia is a very diverse country from a natural geography point of view, with many different habitats within a relatively small area, in addition to major geological and climatic differences. It is therefore not surprising that several small mammal species have been confirmed to harbour hantaviruses: A. flavicollis (Dobrava virus), A. agrarius (Dobrava virus–Kurkino), M. glareolus (Puumala virus), S. areanus (Seewis virus), M. agrestis, M. arvalis and M. subterraneus (Tula virus). Three of the viruses, namely the Dobrava, Dobrava–Kurkino and Puumala viruses, cause disease in humans, with significant differences in the severity of symptoms. Due to changes in haemorrhagic fever with renal syndrome cases (HFRS) epidemiology, a detailed study on phylogenetic diversity and molecular epidemiology of pathogenic and non-pathogenic hantaviruses circulating in ecologically diverse endemic regions was performed. The study presents one of the largest collections of hantavirus L, M and S sequences obtained from hosts and patients within a single country. Several genetic lineages were determined for each hantavirus species, with higher diversity among non-pathogenic compared to pathogenic viruses. For pathogenic hantaviruses, a significant geographic clustering of human- and rodent-derived sequences was confirmed. Several geographic and ecological factors were recognized as influencing and limiting the formation of endemic areas. PMID:24335778

  4. Glycosaminoglycans are involved in pathogen adherence to corneal epithelial cells differently for Gram-positive and Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Beatriz García

    2016-11-01

    Full Text Available The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies.

  5. Surveillance programs for detection and characterization of emergent pathogens and antimicrobial resistance: results from the Division of Infectious Diseases, UNIFESP.

    Science.gov (United States)

    Colombo, Arnaldo L; Janini, Mario; Salomão, Reinaldo; Medeiros, Eduardo A S; Wey, Sergio B; Pignatari, Antonio C C

    2009-09-01

    Several epidemiological changes have occurred in the pattern of nosocomial and community acquired infectious diseases during the past 25 years. Social and demographic changes possibly related to this phenomenon include a rapid population growth, the increase in urban migration and movement across international borders by tourists and immigrants, alterations in the habitats of animals and arthropods that transmit disease, as well as the raise of patients with impaired host defense abilities. Continuous surveillance programs of emergent pathogens and antimicrobial resistance are warranted for detecting in real time new pathogens, as well as to characterize molecular mechanisms of resistance. In order to become more effective, surveillance programs of emergent pathogens should be organized as a multicenter laboratory network connected to the main public and private infection control centers. Microbiological data should be integrated to guide therapy, adapting therapy to local ecology and resistance patterns. This paper presents an overview of data generated by the Division of Infectious Diseases, Federal University of São Paulo, along with its participation in different surveillance programs of nosocomial and community acquired infectious diseases.

  6. Identification and Characterization of Pathogenic and Endophytic Fungal Species Associated with Pokkah Boeng Disease of Sugarcane

    Directory of Open Access Journals (Sweden)

    Angelyn Hilton

    2017-06-01

    Full Text Available Pokkah Boeng is a serious disease of sugarcane, which can lead to devastating yield losses in crop-producing regions, including southern China. However, there is still uncertainty about the causal agent of the disease. Our aim was to isolate and characterize the pathogen through morphological, physiological, and molecular analyses. We isolated sugarcane-colonizing fungi in Fujian, China. Isolated fungi were first assessed for their cell wall degrading enzyme capabilities, and five isolates were identified for further analysis. Internal transcribed spacer sequencing revealed that these five strains are Fusarium, Alternaria, Phoma, Phomopsis, and Epicoccum. The Fusarium isolate was further identified as F. verticillioides after Calmodulin and EF-1α gene sequencing and microscopic morphology study. Pathogenicity assay confirmed that F. verticillioides was directly responsible for disease on sugarcane. Co-inoculation of F. verticillioides with other isolated fungi did not lead to a significant difference in disease severity, refuting the idea that other cellulolytic fungi can increase disease severity as an endophyte. This is the first report characterizing pathogenic F. verticillioides on sugarcane in southern China.

  7. Polypharmacy patterns: unravelling systematic associations between prescribed medications.

    Directory of Open Access Journals (Sweden)

    Amaia Calderón-Larrañaga

    Full Text Available OBJECTIVES: The aim of this study was to demonstrate the existence of systematic associations in drug prescription that lead to the establishment of patterns of polypharmacy, and the clinical interpretation of the associations found in each pattern. METHODS: A cross-sectional study was conducted based on information obtained from electronic medical records and the primary care pharmacy database in 2008. An exploratory factor analysis of drug dispensing information regarding 79,089 adult patients was performed to identify the patterns of polypharmacy. The analysis was stratified by age and sex. RESULTS: Seven patterns of polypharmacy were identified, which may be classified depending on the type of disease they are intended to treat: cardiovascular, depression-anxiety, acute respiratory infection (ARI, chronic obstructive pulmonary disease (COPD, rhinitis-asthma, pain, and menopause. Some of these patterns revealed a clear clinical consistency and included drugs that are prescribed together for the same clinical indication (i.e., ARI and COPD patterns. Other patterns were more complex but also clinically consistent: in the cardiovascular pattern, drugs for the treatment of known risk factors-such as hypertension or dyslipidemia-were combined with other medications for the treatment of diabetes or established cardiovascular pathology (e.g., antiplatelet agents. Almost all of the patterns included drugs for preventing or treating potential side effects of other drugs in the same pattern. CONCLUSIONS: The present study demonstrated the existence of non-random associations in drug prescription, resulting in patterns of polypharmacy that are sound from the pharmacological and clinical viewpoints and that exist in a significant proportion of the population. This finding necessitates future longitudinal studies to confirm some of the proposed causal associations. The information discovered would further the development and/or adaptation of clinical

  8. Inhaled Pollutants: The Molecular Scene behind Respiratory and Systemic Diseases Associated with Ultrafine Particulate Matter

    Directory of Open Access Journals (Sweden)

    Hussein Traboulsi

    2017-01-01

    Full Text Available Air pollution of anthropogenic origin is largely from the combustion of biomass (e.g., wood, fossil fuels (e.g., cars and trucks, incinerators, landfills, agricultural activities and tobacco smoke. Air pollution is a complex mixture that varies in space and time, and contains hundreds of compounds including volatile organic compounds (e.g., benzene, metals, sulphur and nitrogen oxides, ozone and particulate matter (PM. PM0.1 (ultrafine particles (UFP, those particles with a diameter less than 100 nm (includes nanoparticles (NP are considered especially dangerous to human health and may contribute significantly to the development of numerous respiratory and cardiovascular diseases such as chronic obstructive pulmonary disease (COPD and atherosclerosis. Some of the pathogenic mechanisms through which PM0.1 may contribute to chronic disease is their ability to induce inflammation, oxidative stress and cell death by molecular mechanisms that include transcription factors such as nuclear factor κB (NF-κB and nuclear factor (erythroid-derived 2-like 2 (Nrf2. Epigenetic mechanisms including non-coding RNA (ncRNA may also contribute towards the development of chronic disease associated with exposure to PM0.1. This paper highlights emerging molecular concepts associated with inhalational exposure to PM0.1 and their ability to contribute to chronic respiratory and systemic disease.

  9. PatternCoder: A Programming Support Tool for Learning Binary Class Associations and Design Patterns

    Science.gov (United States)

    Paterson, J. H.; Cheng, K. F.; Haddow, J.

    2009-01-01

    PatternCoder is a software tool to aid student understanding of class associations. It has a wizard-based interface which allows students to select an appropriate binary class association or design pattern for a given problem. Java code is then generated which allows students to explore the way in which the class associations are implemented in a…

  10. IMMUNOSTIMULATORY PROPERTIES OF DENDRIMERS MULTIVALENTLY PRESENTING MURAMYLDIPEPTIDE

    DEFF Research Database (Denmark)

    Objectives: Many pathogens will only be efficiently neutralized by the induction of cell-mediated immunity, and with the enhanced use of subunit-vaccine approaches there is a strong need for the development of efficient and safe Th1-biassing adjuvants. Pathogen-associated molecular patterns (PAMPs...

  11. Effect of sunlight on the survival of pathogenic E. coli in freshwater and sea water

    DEFF Research Database (Denmark)

    Surendraraj, Alagarsamy; Farvin, Sabeena; Thampuran, N.

    2011-01-01

    An enteropathogenic group of E. coli are the emerging category of pathogen of public health significance. Several recent pathogenic E. coli outbreaks are associated with drinking water. Aquaculture, the fast emerging food production sector also poses a pathogenic EHEC outbreak risk, as it regularly...... uses cow dung, a reservoir of this organism. Hence, a experiment was set up to study the duration of survival of pathogenic E. coli under sunlight and darkness. Eight pathogenic E. coli isolates from clinical (EPEC, ETEC, EHEC, EAEC), veterinary (CTE3, CTE4) and environmental sources (ASHE3, Rao II......) were studied for their survival under sunlight and darkness in fresh water and seawater. Effect of direct sunlight on the viable but nonculturable (VBNC) state of cultures was also studied. The results of the study indicated a distinct pattern between freshwater system and seawater system. Pathogenic E...

  12. A network approach to predict pathogenic genes for Fusarium graminearum.

    Science.gov (United States)

    Liu, Xiaoping; Tang, Wei-Hua; Zhao, Xing-Ming; Chen, Luonan

    2010-10-04

    Fusarium graminearum is the pathogenic agent of Fusarium head blight (FHB), which is a destructive disease on wheat and barley, thereby causing huge economic loss and health problems to human by contaminating foods. Identifying pathogenic genes can shed light on pathogenesis underlying the interaction between F. graminearum and its plant host. However, it is difficult to detect pathogenic genes for this destructive pathogen by time-consuming and expensive molecular biological experiments in lab. On the other hand, computational methods provide an alternative way to solve this problem. Since pathogenesis is a complicated procedure that involves complex regulations and interactions, the molecular interaction network of F. graminearum can give clues to potential pathogenic genes. Furthermore, the gene expression data of F. graminearum before and after its invasion into plant host can also provide useful information. In this paper, a novel systems biology approach is presented to predict pathogenic genes of F. graminearum based on molecular interaction network and gene expression data. With a small number of known pathogenic genes as seed genes, a subnetwork that consists of potential pathogenic genes is identified from the protein-protein interaction network (PPIN) of F. graminearum, where the genes in the subnetwork are further required to be differentially expressed before and after the invasion of the pathogenic fungus. Therefore, the candidate genes in the subnetwork are expected to be involved in the same biological processes as seed genes, which imply that they are potential pathogenic genes. The prediction results show that most of the pathogenic genes of F. graminearum are enriched in two important signal transduction pathways, including G protein coupled receptor pathway and MAPK signaling pathway, which are known related to pathogenesis in other fungi. In addition, several pathogenic genes predicted by our method are verified in other pathogenic fungi, which

  13. A network approach to predict pathogenic genes for Fusarium graminearum.

    Directory of Open Access Journals (Sweden)

    Xiaoping Liu

    Full Text Available Fusarium graminearum is the pathogenic agent of Fusarium head blight (FHB, which is a destructive disease on wheat and barley, thereby causing huge economic loss and health problems to human by contaminating foods. Identifying pathogenic genes can shed light on pathogenesis underlying the interaction between F. graminearum and its plant host. However, it is difficult to detect pathogenic genes for this destructive pathogen by time-consuming and expensive molecular biological experiments in lab. On the other hand, computational methods provide an alternative way to solve this problem. Since pathogenesis is a complicated procedure that involves complex regulations and interactions, the molecular interaction network of F. graminearum can give clues to potential pathogenic genes. Furthermore, the gene expression data of F. graminearum before and after its invasion into plant host can also provide useful information. In this paper, a novel systems biology approach is presented to predict pathogenic genes of F. graminearum based on molecular interaction network and gene expression data. With a small number of known pathogenic genes as seed genes, a subnetwork that consists of potential pathogenic genes is identified from the protein-protein interaction network (PPIN of F. graminearum, where the genes in the subnetwork are further required to be differentially expressed before and after the invasion of the pathogenic fungus. Therefore, the candidate genes in the subnetwork are expected to be involved in the same biological processes as seed genes, which imply that they are potential pathogenic genes. The prediction results show that most of the pathogenic genes of F. graminearum are enriched in two important signal transduction pathways, including G protein coupled receptor pathway and MAPK signaling pathway, which are known related to pathogenesis in other fungi. In addition, several pathogenic genes predicted by our method are verified in other

  14. Morphological characteristics and pathogenicity of fungi associated with Roselle (Hibiscus Sabdariffa) diseases in Penang, Malaysia.

    Science.gov (United States)

    Eslaminejad, Touba; Zakaria, Maziah

    2011-11-01

    Roselle, or Jamaica sorrel (Hibiscus sabdariffa) is a popular vegetable in many tropical regions, cultivated for its leaves, seeds, stems and calyces which, the dried calyces are used to prepare tea, syrup, jams and jellies and as beverages. The main objectives of this study were to identify and characterise fungal pathogens associated with Roselle diseases based on their morphological and cultural characteristics and to determine the pathogenicity of four fungi infecting Roselle seedlings, namely Phoma exigua, Fusarium nygamai, Fusarium tgcq and Rhizoctonia solani in Penang. A total of 200 fungal isolates were obtained from 90 samples of symptomatic Roselle tissues. The isolates were identified based on cultural and morphological characteristics, as well as their pathogenicity. The fungal pathogen most frequently isolated was P. exigua (present in 45% of the samples), followed by F. nygamai (25%), Rhizoctonia solani (19%) and F. camptoceras (11%). Pathogenicity tests showed that P. exigua, F. nygamai, F. camptoceras and R. solani were able to infect both wounded and unwounded seedlings with different degrees of severity as indicated by the Disease severity (DS). R. solani was the most pathogenic fungus affecting both wounded and unwounded Roselle seedlings, followed by P. exigua that was highly pathogenic on wounded seedlings. F. nygamai was less pathogenic while the least pathogenic fungus was F. camptoceras, infecting only the unwounded seedlings but, surprisingly, not the wounded plants. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Urethritis/cervicitis pathogen prevalence and associated risk factors among asymptomatic HIV-infected patients in South Africa.

    Science.gov (United States)

    Lewis, David A; Chirwa, Tobias F; Msimang, Veerle M Y; Radebe, Frans M; Kamb, Mary L; Firnhaber, Cynthia S

    2012-07-01

    To determine sexually transmitted infection (STI) prevalence, and patient characteristics associated with detection of urethritis/cervicitis pathogens, among HIV-infected individuals offered voluntary STI screening at a South African HIV treatment center. Individuals, asymptomatic for genital discharge, were screened for Neisseria gonorrhoeae (NG), Chlamydia trachomatis, Trichomonas vaginalis (TV), Mycoplasma genitalium (MG) infections (real-time polymerase chain reaction assay), for syphilis and herpes simplex type 2 (serologically), and for bacterial vaginosis and Candida (microscopy, women only). Patients' most recent CD4 and viral load results were recorded. Demographic, clinical, and behavioral data were collected by nurse-administered questionnaire. Compared with men (n = 551), women (n = 558) were younger (mean age, 35.0 vs. 37.9 years; P urethritis/cervicitis pathogens detected (21.3% vs.16.4%, P = 0.035), and were less aware of their partner's HIV status (53.1% vs. 62.3%; P = 0.007). The overall prevalence of individual urethritis/cervicitis pathogens was TV (7.6%), MG (6.1%), NG (5.4%), and C. trachomatis (2.1%). Multivariate analysis highlighted 4 significant factors associated with the detection of specific urethritis/cervicitis pathogens, namely female gender (TV, adjusted odds ratio [aOR] 2.53, 95% confidence interval [CI]: 1.47-4.37), having a regular sexual partner in the past 3 months (NG, aOR 2.26, 95% CI: 1.01-5.08), suboptimal condom use with regular partners (TV, aOR 2.07, 95% CI: 1.25-3.42), and a history of genital warts in the past year (NG, 2.25, 95% CI: 1.26-4.03). Asymptomatic urethritis/cervicitis pathogens were highly prevalent in this population. Few urethritis/cervicitis pathogen-associated patient characteristics were identified, emphasizing the need for affordable STI diagnostics to screen HIV-infected patients.

  16. Jasmonate ZIM-domain (JAZ protein regulates host and nonhost pathogen-induced cell death in tomato and Nicotiana benthamiana.

    Directory of Open Access Journals (Sweden)

    Yasuhiro Ishiga

    Full Text Available The nonhost-specific phytotoxin coronatine (COR produced by several pathovars of Pseudomonas syringae functions as a jasmonic acid-isoleucine (JA-Ile mimic and contributes to disease development by suppressing plant defense responses and inducing reactive oxygen species in chloroplast. It has been shown that the F-box protein CORONATINE INSENSITIVE 1 (COI1 is the receptor for COR and JA-Ile. JASMONATE ZIM DOMAIN (JAZ proteins act as negative regulators for JA signaling in Arabidopsis. However, the physiological significance of JAZ proteins in P. syringae disease development and nonhost pathogen-induced hypersensitive response (HR cell death is not completely understood. In this study, we identified JAZ genes from tomato, a host plant for P. syringae pv. tomato DC3000 (Pst DC3000, and examined their expression profiles in response to COR and pathogens. Most JAZ genes were induced by COR treatment or inoculation with COR-producing Pst DC3000, but not by the COR-defective mutant DB29. Tomato SlJAZ2, SlJAZ6 and SlJAZ7 interacted with SlCOI1 in a COR-dependent manner. Using virus-induced gene silencing (VIGS, we demonstrated that SlJAZ2, SlJAZ6 and SlJAZ7 have no effect on COR-induced chlorosis in tomato and Nicotiana benthamiana. However, SlJAZ2-, SlJAZ6- and SlJAZ7-silenced tomato plants showed enhanced disease-associated cell death to Pst DC3000. Furthermore, we found delayed HR cell death in response to the nonhost pathogen Pst T1 or a pathogen-associated molecular pattern (PAMP, INF1, in SlJAZ2- and SlJAZ6-silenced N. benthamiana. These results suggest that tomato JAZ proteins regulate the progression of cell death during host and nonhost interactions.

  17. Coherent Rabi oscillations in a molecular system and sub-diffraction-limited pattern generation

    International Nuclear Information System (INIS)

    Liao, Zeyang; Al-Amri, M; Zubairy, M Suhail

    2015-01-01

    The resolution of a photolithography and optical imaging system is restricted by the diffraction limit. Coherent Rabi oscillations have been shown to be able to overcome the diffraction limit in a simple two-level atomic system (Z Liao, M Al-amri, and M S Zubairy 2010 Phys. Rev. Lett. 105 183601). In this paper, we numerically calculate the wave packet dynamics of a molecular system interacting with an ultrashort laser pulse and show that coherent Rabi oscillations in a molecular system are also possible. Moreover, a sub-diffraction-limited pattern can be generated in this system by introducing spatially modulated Rabi oscillations. We also discuss several techniques to improve the visibility of the sub-diffraction-limited pattern. Our result may have important applications in super-resolution optical lithography and optical imaging. (paper)

  18. [Low-grade systemic inflammation and the development of metabolic diseases: from the molecular evidence to the clinical practice].

    Science.gov (United States)

    León-Pedroza, José Israel; González-Tapia, Luis Alonso; del Olmo-Gil, Esteban; Castellanos-Rodríguez, Diana; Escobedo, Galileo; González-Chávez, Antonio

    2015-01-01

    Systemic inflammation is characterised by high circulating levels of inflammatory cytokines and increased macrophage infiltration in peripheral tissues. Most importantly, this inflammatory state does not involve damage or loss of function of the infiltrated tissue, which is a distinctive feature of the low-grade systemic inflammation. The term "meta-inflammation" has also been used to refer to the low-grade systemic inflammation due to its strong relationship with the development of cardio-metabolic diseases in obesity. A review is presented on the recent clinical and experimental evidence concerning the role of adipose tissue inflammation as a key mediator of low-grade systemic inflammation. Furthermore, the main molecular mechanisms involved in the inflammatory polarization of macrophages with the ability to infiltrate both the adipose tissue and the vascular endothelium via activation of toll-like receptors by metabolic damage-associated molecular patterns, such as advanced glycation-end products and oxidized lipoproteins, is discussed. Finally, a review is made of the pathogenic mechanisms through which the low-grade systemic inflammation contributes to develop insulin resistance, dyslipidaemia, atherogenesis, type 2 diabetes, and hypertension in obese individuals. A better understanding of the molecular mechanisms of low-grade systemic inflammation in promoting cardio-metabolic diseases is necessary, in order to further design novel anti-inflammatory therapies that take into consideration clinical data, as well as the circulating levels of cytokines, immune cells, and metabolic damage-associated molecular patterns in each patient. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

  19. The association between foodborne and orofecal pathogens and allergic sensitisation -- EuroPrevall study

    NARCIS (Netherlands)

    Janse, Jacqueline J.; Wong, Gary W. K.; Potts, James; Ogorodova, Ludmila M.; Fedorova, Olga S.; Mahesh, P. A.; Sakellariou, Alexandros; Papadopoulos, Nikolaos G.; Knulst, André C.; Versteeg, Serge A.; Kroes, Aloys C. M.; Vossen, Ann C. T. M.; Campos Ponce, Maiza; Kummeling, Ischa; Burney, Peter; van Ree, Ronald; Yazdanbakhsh, Maria

    2014-01-01

    An inverse association between markers of exposure to foodborne and orofecal pathogens and allergic sensitization has been reported. However, the findings of epidemiological studies have not been consistent. This study investigated the relationship between antibodies to hepatitis A, Toxoplasma

  20. The association between foodborne and orofecal pathogens and allergic sensitisation - EuroPrevall study

    NARCIS (Netherlands)

    Janse, J.J.; Wong, G.W.K.; Potts, J.; Ogorodova, L.M.; Fedorova, O.S.; Mahesh, P.A.; Sakellariou, A.; Papadopoulos, N.G.; Knulst, A.C.; Versteeg, S.A.; Kroes, A.C.M.; Vossen, A.C.T.M.; Campos Ponce, M.; Kummeling, I.; Burney, P.; van Ree, R.; Yazdanbakhsh, M.

    2014-01-01

    Background: An inverse association between markers of exposure to foodborne and orofecal pathogens and allergic sensitization has been reported. However, the findings of epidemiological studies have not been consistent. This study investigated the relationship between antibodies to hepatitis A,

  1. Different Use of Cell Surface Glycosaminoglycans As Adherence Receptors to Corneal Cells by Gram Positive and Gram Negative Pathogens

    Science.gov (United States)

    García, Beatriz; Merayo-Lloves, Jesús; Rodríguez, David; Alcalde, Ignacio; García-Suárez, Olivia; Alfonso, José F.; Baamonde, Begoña; Fernández-Vega, Andrés; Vazquez, Fernando; Quirós, Luis M.

    2016-01-01

    The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive, and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies. PMID:27965938

  2. Effects of co-occurring Wolbachia and Spiroplasma endosymbionts on the Drosophila immune response against insect pathogenic and non-pathogenic bacteria.

    Science.gov (United States)

    Shokal, Upasana; Yadav, Shruti; Atri, Jaishri; Accetta, Julia; Kenney, Eric; Banks, Katherine; Katakam, Akash; Jaenike, John; Eleftherianos, Ioannis

    2016-02-09

    Symbiotic interactions between microbes and animals are common in nature. Symbiotic organisms are particularly common in insects and, in some cases, they may protect their hosts from pathogenic infections. Wolbachia and Spiroplasma endosymbionts naturally inhabit various insects including Drosophila melanogaster fruit flies. Therefore, this symbiotic association is considered an excellent model to investigate whether endosymbiotic bacteria participate in host immune processes against certain pathogens. Here we have investigated whether the presence of Wolbachia alone or together with Spiroplasma endosymbionts in D. melanogaster adult flies affects the immune response against the virulent insect pathogen Photorhabdus luminescens and against non-pathogenic Escherichia coli bacteria. We found that D. melanogaster flies carrying no endosymbionts, those carrying both Wolbachia and Spiroplasma, and those containing Wolbachia only had similar survival rates after infection with P. luminescens or Escherichia coli bacteria. However, flies carrying both endosymbionts or Wolbachia only contained higher numbers of E. coli cells at early time-points post infection than flies without endosymbiotic bacteria. Interestingly, flies containing Wolbachia only had lower titers of this endosymbiont upon infection with the pathogen P. luminescens than uninfected flies of the same strain. We further found that the presence of Wolbachia and Spiroplasma in D. melanogaster up-regulated certain immune-related genes upon infection with P. luminescens or E. coli bacteria, but it failed to alter the phagocytic ability of the flies toward E. coli inactive bioparticles. Our results suggest that the presence of Wolbachia and Spiroplasma in D. melanogaster can modulate immune signaling against infection by certain insect pathogenic and non-pathogenic bacteria. Results from such studies are important for understanding the molecular basis of the interactions between endosymbiotic bacteria of insects

  3. Seasonal Patterns of Gastrointestinal Illness and Streamflow along the Ohio River

    Directory of Open Access Journals (Sweden)

    Elena N. Naumova

    2012-05-01

    Full Text Available Waterborne gastrointestinal (GI illnesses demonstrate seasonal increases associated with water quality and meteorological characteristics. However, few studies have been conducted on the association of hydrological parameters, such as streamflow, and seasonality of GI illnesses. Streamflow is correlated with biological contamination and can be used as proxy for drinking water contamination. We compare seasonal patterns of GI illnesses in the elderly (65 years and older along the Ohio River for a 14-year period (1991–2004 to seasonal patterns of streamflow. Focusing on six counties in close proximity to the river, we compiled weekly time series of hospitalizations for GI illnesses and streamflow data. Seasonal patterns were explored using Poisson annual harmonic regression with and without adjustment for streamflow. GI illnesses demonstrated significant seasonal patterns with peak timing preceding peak timing of streamflow for all six counties. Seasonal patterns of illness remain consistent after adjusting for streamflow. This study found that the time of peak GI illness precedes the peak of streamflow, suggesting either an indirect relationship or a more direct path whereby pathogens enter water supplies prior to the peak in streamflow. Such findings call for interdisciplinary research to better understand associations among streamflow, pathogen loading, and rates of gastrointestinal illnesses.

  4. The Venturia Apple Pathosystem: Pathogenicity Mechanisms and Plant Defense Responses

    Directory of Open Access Journals (Sweden)

    Gopaljee Jha

    2009-01-01

    Full Text Available Venturia inaequalis is the causal agent of apple scab, a devastating disease of apple. We outline several unique features of this pathogen which are useful for molecular genetics studies intended to understand plant-pathogen interactions. The pathogenicity mechanisms of the pathogen and overview of apple defense responses, monogenic and polygenic resistance, and their utilization in scab resistance breeding programs are also reviewed.

  5. Immune Evasion Strategies of Pathogens in Macrophages: the Potential for Limiting Pathogen Transmission.

    Science.gov (United States)

    Ren, Yuwei; Khan, Faheem Ahmed; Pandupuspitasari, Nuruliarizki Shinta; Zhang, Shujun

    2017-01-01

    Preventing pathogen transmission to a new host is of major interest to the immunologist and could benefit from a detailed investigation of pathogen immune evasion strategies. The first line of defense against pathogen invasion is provided by macrophages. When they sense pathogens, macrophages initiate signals to inflammatory and pro-inflammatory cytokines through pattern recognition receptors (PRRs) subsequently mediating phagocytosis and inflammation. The macrophage immune machinery classically includes two subsets: the activated M1 and the activated M2 that respond accordingly in diverse immune challenges. The lipid and glycogen metabolic pathways work together with the lysosome to help the mature phagosome to degrade and eliminate intracellular pathogens in macrophages. The viral evasion strategies are even more complex due to the interplay between autophagy and apoptosis. However, pathogens evolve several strategies to camouflage themselves against immune responses in order to ensure their survival, replication and transmission. These strategies include the muting of PRRs initiated inflammatory responses, attenuation of M1 and/or induction of M2 macrophages, suppression of autophago-lysosomal formation, interference with lipid and glycogen metabolism, and viral mediation of autophagy and apoptosis cross-talk to enhance viral replication. This review focuses on pathogen immune evasion methods and on the strategies used by the host against camouflaged pathogens.

  6. Adhesion of Human Probiotic Lactobacillus rhamnosus to Cervical and Vaginal Cells and Interaction with Vaginosis-Associated Pathogens

    Directory of Open Access Journals (Sweden)

    Sophie Coudeyras

    2008-01-01

    Full Text Available Objectives. The ability of a probiotic Lactobacillus rhamnosus strain (Lcr35 to adhere to cervical and vaginal cells and to affect the viability of two main vaginosis-associated pathogens, Prevotella bivia, Gardnerella vaginalis, as well as Candida albicans was investigated. Methods. Adhesion ability was determined in vitro with immortalized epithelial cells from the endocervix, ectocervix, and vagina. Coculture experiments were performed to count viable pathogens cells in the presence of Lcr35. Results. Lcr35 was able to specifically and rapidly adhere to the three cell lines. In coculture assays, a decrease in pathogen cell division rate was observed as from 4 hours of incubation and bactericidal activity after a longer period of incubation, mostly with P. bivia. Conclusion. The ability of Lcr35 to adhere to cervicovaginal cells and its antagonist activities against vaginosis-associated pathogens suggest that this probiotic strain is a promising candidate for use in therapy.

  7. Metabolic Environments and Genomic Features Associated with Pathogenic and Mutualistic Interactions between Bacteria and Plants is accepted for publication in MPMI

    Energy Technology Data Exchange (ETDEWEB)

    Karpinets, Tatiana V [ORNL; Park, Byung H [ORNL; Syed, Mustafa H [ORNL; Klotz, Martin G [University of North Carolina, Charlotte; Uberbacher, Edward C [ORNL

    2014-01-01

    Most bacterial symbionts of plants are phenotypically characterized by their parasitic or matualistic relationship with the host; however, the genomic characteristics that likely discriminate mutualistic symbionts from pathogens of plants are poorly understood. This study comparatively analyzed the genomes of 54 plant-symbiontic bacteria, 27 mutualists and 27 pathogens, to discover genomic determinants of their parasitic and mutualistic nature in terms of protein family domains, KEGG orthologous groups, metabolic pathways and families of carbohydrate-active enzymes (CAZymes). We further used all bacteria with sequenced genomesl, published microarrays and transcriptomics experimental datasets, and literature to validate and to explore results of the comparison. The analysis revealed that genomes of mutualists are larger in size and higher in GC content and encode greater molecular, functional and metabolic diversity than the investigated genomes of pathogens. This enriched molecular and functional enzyme diversity included constructive biosynthetic signatures of CAZymes and metabolic pathways in genomes of mutualists compared with catabolic signatures dominant in the genomes of pathogens. Another discriminative characteristic of mutualists is the co-occurence of gene clusters required for the expression and function of nitrogenase and RuBisCO. Analysis of previously published experimental data indicate that nitrogen-fixing mutualists may employ Rubisco to fix CO2 not in the canonical Calvin-Benson-Basham cycle but in a novel metabolic pathway, here called Rubisco-based glycolysis , to increase efficiency of sugar utilization during the symbiosis with plants. An important discriminative characteristic of plant pathogenic bacteria is two groups of genes likely encoding effector proteins involved in host invasion and a genomic locus encoding a putative secretion system that includes a DUF1525 domain protein conserved in pathogens of plants and of other organisms. The

  8. Gene expression profiles associated with the presence of a fibrotic focus and the growth pattern in lymph node-negative breast cancer

    NARCIS (Netherlands)

    G. van den Eynden; M. Smid (Marcel); S.J. van Laere (Steven); C.G. Colpaert (Cecile); U.D. van Auwera; T.X. Bich; P. van Dam (Peter); M.A. den Bakker (Michael); L.Y. Dirix (Luc); E.A. van Marck (Eric); P.B. Vermeulen (Peter); J.A. Foekens (John)

    2008-01-01

    textabstractPurpose: A fibrotic focus, the scar-like area found in the center of an invasive breast tumor, is a prognostic parameter associated with an expansive growth pattern, hypoxia, and (lymph) angiogenesis. Little is known about the molecular pathways involved. Experimental Design: Sixty-five

  9. A novel role for the TIR domain in association with pathogen-derived elicitors.

    Directory of Open Access Journals (Sweden)

    Tessa M Burch-Smith

    2007-03-01

    Full Text Available Plant innate immunity is mediated by Resistance (R proteins, which bear a striking resemblance to animal molecules of similar function. Tobacco N is a TIR-NB-LRR R gene that confers resistance to Tobacco mosaic virus, specifically the p50 helicase domain. An intriguing question is how plant R proteins recognize the presence of pathogen-derived Avirulence (Avr elicitor proteins. We have used biochemical cell fraction and immunoprecipitation in addition to confocal fluorescence microscopy of living tissue to examine the association between N and p50. Surprisingly, both N and p50 are cytoplasmic and nuclear proteins, and N's nuclear localization is required for its function. We also demonstrate an in planta association between N and p50. Further, we show that N's TIR domain is critical for this association, and indeed, it alone can associate with p50. Our results differ from current models for plant innate immunity that propose detection is mediated solely through the LRR domains of these molecules. The data we present support an intricate process of pathogen elicitor recognition by R proteins involving multiple subcellular compartments and the formation of multiple protein complexes.

  10. The genomic organization of plant pathogenicity in Fusarium species

    NARCIS (Netherlands)

    Rep, M.; Kistler, H.C.

    2010-01-01

    Comparative genomics is a powerful tool to infer the molecular basis of fungal pathogenicity and its evolution by identifying differences in gene content and genomic organization between fungi with different hosts or modes of infection. Through comparative analysis, pathogenicity-related chromosomes

  11. Prospects of Understanding the Molecular Biology of Disease Resistance in Rice

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Singh

    2018-04-01

    Full Text Available Rice is one of the important crops grown worldwide and is considered as an important crop for global food security. Rice is being affected by various fungal, bacterial and viral diseases resulting in huge yield losses every year. Deployment of resistance genes in various crops is one of the important methods of disease management. However, identification, cloning and characterization of disease resistance genes is a very tedious effort. To increase the life span of resistant cultivars, it is important to understand the molecular basis of plant host–pathogen interaction. With the advancement in rice genetics and genomics, several rice varieties resistant to fungal, bacterial and viral pathogens have been developed. However, resistance response of these varieties break down very frequently because of the emergence of more virulent races of the pathogen in nature. To increase the durability of resistance genes under field conditions, understanding the mechanismof resistance response and its molecular basis should be well understood. Some emerging concepts like interspecies transfer of pattern recognition receptors (PRRs and transgenerational plant immunitycan be employed to develop sustainable broad spectrum resistant varieties of rice.

  12. Comprehensive microarray-based analysis for stage-specific larval camouflage pattern-associated genes in the swallowtail butterfly, Papilio xuthus

    Directory of Open Access Journals (Sweden)

    Futahashi Ryo

    2012-05-01

    Full Text Available Abstract Background Body coloration is an ecologically important trait that is often involved in prey-predator interactions through mimicry and crypsis. Although this subject has attracted the interest of biologists and the general public, our scientific knowledge on the subject remains fragmentary. In the caterpillar of the swallowtail butterfly Papilio xuthus, spectacular changes in the color pattern are observed; the insect mimics bird droppings (mimetic pattern as a young larva, and switches to a green camouflage coloration (cryptic pattern in the final instar. Despite the wide variety and significance of larval color patterns, few studies have been conducted at a molecular level compared with the number of studies on adult butterfly wing patterns. Results To obtain a catalog of genes involved in larval mimetic and cryptic pattern formation, we constructed expressed sequence tag (EST libraries of larval epidermis for P. xuthus, and P. polytes that contained 20,736 and 5,376 clones, respectively, representing one of the largest collections available in butterflies. A comparison with silkworm epidermal EST information revealed the high expression of putative blue and yellow pigment-binding proteins in Papilio species. We also designed a microarray from the EST dataset information, analyzed more than five stages each for six markings, and confirmed spatial expression patterns by whole-mount in situ hybridization. Hence, we succeeded in elucidating many novel marking-specific genes for mimetic and cryptic pattern formation, including pigment-binding protein genes, the melanin-associated gene yellow-h3, the ecdysteroid synthesis enzyme gene 3-dehydroecdysone 3b-reductase, and Papilio-specific genes. We also found many cuticular protein genes with marking specificity that may be associated with the unique surface nanostructure of the markings. Furthermore, we identified two transcription factors, spalt and ecdysteroid signal-related E75, as genes

  13. Algae as reservoirs for coral pathogens.

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    Michael J Sweet

    Full Text Available Benthic algae are associated with coral death in the form of stress and disease. It's been proposed that they release exudates, which facilitate invasion of potentially pathogenic microbes at the coral-algal interface, resulting in coral disease. However, the original source of these pathogens remains unknown. This study examined the ability of benthic algae to act as reservoirs of coral pathogens by characterizing surface associated microbes associated with major Caribbean and Indo-Pacific algal species/types and by comparing them to potential pathogens of two dominant coral diseases: White Syndrome (WS in the Indo-Pacific and Yellow Band Disease (YBD in the Caribbean. Coral and algal sampling was conducted simultaneously at the same sites to avoid spatial effects. Potential pathogens were defined as those absent or rare in healthy corals, increasing in abundance in healthy tissues adjacent to a disease lesion, and dominant in disease lesions. Potentially pathogenic bacteria were detected in both WS and YBD and were also present within the majority of algal species/types (54 and 100% for WS and YBD respectively. Pathogenic ciliates were associated only with WS and not YBD lesions and these were also present in 36% of the Indo-Pacific algal species. Although potential pathogens were associated with many algal species, their presence was inconsistent among replicate algal samples and detection rates were relatively low, suggestive of low density and occurrence. At the community level, coral-associated microbes irrespective of the health of their host differed from algal-associated microbes, supporting that algae and corals have distinctive microbial communities associated with their tissue. We conclude that benthic algae are common reservoirs for a variety of different potential coral pathogens. However, algal-associated microbes alone are unlikely to cause coral death. Initial damage or stress to the coral via other competitive mechanisms is

  14. Gene expression patterns associated with neurological disease in human HIV infection.

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    Pietro Paolo Sanna

    Full Text Available The pathogenesis and nosology of HIV-associated neurological disease (HAND remain incompletely understood. Here, to provide new insight into the molecular events leading to neurocognitive impairments (NCI in HIV infection, we analyzed pathway dysregulations in gene expression profiles of HIV-infected patients with or without NCI and HIV encephalitis (HIVE and control subjects. The Gene Set Enrichment Analysis (GSEA algorithm was used for pathway analyses in conjunction with the Molecular Signatures Database collection of canonical pathways (MSigDb. We analyzed pathway dysregulations in gene expression profiles of patients from the National NeuroAIDS Tissue Consortium (NNTC, which consists of samples from 3 different brain regions, including white matter, basal ganglia and frontal cortex of HIV-infected and control patients. While HIVE is characterized by widespread, uncontrolled inflammation and tissue damage, substantial gene expression evidence of induction of interferon (IFN, cytokines and tissue injury is apparent in all brain regions studied, even in the absence of NCI. Various degrees of white matter changes were present in all HIV-infected subjects and were the primary manifestation in patients with NCI in the absence of HIVE. In particular, NCI in patients without HIVE in the NNTC sample is associated with white matter expression of chemokines, cytokines and β-defensins, without significant activation of IFN. Altogether, the results identified distinct pathways differentially regulated over the course of neurological disease in HIV infection and provide a new perspective on the dynamics of pathogenic processes in the course of HIV neurological disease in humans. These results also demonstrate the power of the systems biology analyses and indicate that the establishment of larger human gene expression profile datasets will have the potential to provide novel mechanistic insight into the pathogenesis of neurological disease in HIV

  15. MOLECULAR PATTERN OF MYCOBACTERIUM BOVIS ISOLATES AND ITS RELATIONSHIP WITH RISK FACTORS ASSOCIATED WITH THE PRESENCE OF BOVINE TUBERCULOSIS IN NORTHERN MEXICO

    Directory of Open Access Journals (Sweden)

    I. F. Padilla

    2011-02-01

    Full Text Available The objective of this study was to determine the molecular pattern of M. bovis isolates from cattle of Northern Mexico and its relationship with some risk factors. Isolates (n=60 were obtained from the states of Coahuila (COA, n=14, Tamaulipas (TAM, n=16, Nuevo Leon (NL, n=14 and Baja California and Durango (DUR, n=16. The risk factors studied were: system of production (Dairy and Beef, state, age, lesion type (localized and generalized, and type of presentation (caseous and calcified. Samples were analyzed at the Regional Laboratory of Monterrey NL, following a spoligotyping protocol. Twenty-five spoligotypes belonging to the M. bovis complex were identified. Eleven (18.3% isolates presented a unique pattern, whereas 49 (81.7% were grouped in 14 clusters. The largest clusters had 12 and 17 isolates. The average heterozygocities per state were 21.4% (NL, 15.6% (TAM, 15.6% COA and 9.9% (DUR. The genetic distances of the isolates between states did not show differences (P > 0.05 when examined by Chi-square tests. The average genetic diversity (15.6% was due to the variation of strains within subpopulations. In this study an 8.3% difference among states was obtained, which suggest the idea of a unique strain of M. bovis with many variants and that the genetic diversity found for M. bovis could be in part due to the movement of animals between regions. Statistical analysis did not show association (P > 0.05 between risk factors and strains of M. bovis.

  16. Damage/Danger Associated Molecular Patterns (DAMPs Modulate Chlamydia pecorum and C. trachomatis Serovar E Inclusion Development In Vitro.

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    Cory Ann Leonard

    Full Text Available Persistence, more recently termed the chlamydial stress response, is a viable but non-infectious state constituting a divergence from the characteristic chlamydial biphasic developmental cycle. Damage/danger associated molecular patterns (DAMPs are normal intracellular components or metabolites that, when released from cells, signal cellular damage/lysis. Purine metabolite DAMPs, including extracellular ATP and adenosine, inhibit chlamydial development in a species-specific manner. Viral co-infection has been shown to reversibly abrogate Chlamydia inclusion development, suggesting persistence/chlamydial stress. Because viral infection can cause host cell DAMP release, we hypothesized DAMPs may influence chlamydial development. Therefore, we examined the effect of extracellular ATP, adenosine, and cyclic AMP exposure, at 0 and 14 hours post infection, on C. pecorum and C. trachomatis serovar E development. In the absence of de novo host protein synthesis, exposure to DAMPs immediately post or at 14 hours post infection reduced inclusion size; however, the effect was less robust upon 14 hours post infection exposure. Additionally, upon exposure to DAMPs immediately post infection, bacteria per inclusion and subsequent infectivity were reduced in both Chlamydia species. These effects were reversible, and C. pecorum exhibited more pronounced recovery from DAMP exposure. Aberrant bodies, typical in virus-induced chlamydial persistence, were absent upon DAMP exposure. In the presence of de novo host protein synthesis, exposure to DAMPs immediately post infection reduced inclusion size, but only variably modulated chlamydial infectivity. Because chlamydial infection and other infections may increase local DAMP concentrations, DAMPs may influence Chlamydia infection in vivo, particularly in the context of poly-microbial infections.

  17. PORCINE CYTOKINE RESPONSES TO PAMP-STRUCTURES IN VITRO

    DEFF Research Database (Denmark)

    Sørensen, Nanna Skall; Skovgaard, Kerstin; Vorsholt, Henriette

    Pathogen-associated molecular patterns (PAMPs) are conserved microbial structures recognized by pattern-recognition receptors (PRRs) of the innate immune system. Binding of PAMPs by certain PRRs on dendritic cells induces these to express costimulatory molecules and cytokines, enabling an inducti...

  18. Periodontal-disease-associated biofilm: A reservoir for pathogens of medical importance.

    Science.gov (United States)

    Vieira Colombo, Ana Paula; Magalhães, Clarissa Bichara; Hartenbach, Fátima Aparecida Rocha Resende; Martins do Souto, Renata; Maciel da Silva-Boghossian, Carina

    2016-05-01

    The ecological diversity of the periodontal microenvironment may provide suitable conditions for the colonization of species not usually considered members of the oral microbiota. In this investigation, we aimed to determine the prevalence and levels of pathogenic species of medical relevance in the microbiota of individuals with distinct periodontal clinical status. Subgingival biofilm was obtained from patients with periodontal health (H, n = 81), gingivitis (G, n = 55), generalized aggressive (AgP, n = 36) or chronic periodontitis (CP, n = 98), and analyzed for 39 microbial taxa using a checkerboard DNA-DNA hybridization technique. Microbial differences among groups, as well as associations between clinical and microbiological parameters were sought by non-parametric and univariate correlation tests. Neisseria spp., Peptostreptococus anaerobius, Candida albicans, enterobacteria, Pseudomonas aeruginosa, Eubacterium saphenum, Clostridium difficile and Olsenella uli were detected in high mean prevalence and counts in the subgingival microbiota of the study population. Species that were more related to periodontal inflammation and tissue destruction at the patient and site levels included enterobacteria, C. albicans, Neisseria spp., P. aeruginosa, O. uli, Hafnia alvei, Serratia marcescens and Filifactor alocis (p < 0.05). In contrast, Fusobacterium necrophorum, Lactobacillus acidophilus, Staphylococcus aureus and Streptococcus pneumoniae were associated with periodontal health (p < 0.05). Pathogenic species of medical importance may be detected in high prevalence and levels in the periodontal microbiota. Regardless of their role in periodontal health or disease, the periodontal biofilm may be a source for dissemination and development of systemic infections by these pathogenic microorganisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Recent developments in pathogen detection arrays: implications for fungal plant pathogens and use in practica

    NARCIS (Netherlands)

    Lievens, B.; Thomma, B.P.H.J.

    2005-01-01

    The failure to adequately identify plant pathogens from culture-based morphological techniques has led to the development of culture-independent molecular approaches. Increasingly, diagnostic laboratories are pursuing fast routine methods that provide reliable identification, sensitive detection,

  20. Protein-protein association and cellular localization of four essential gene products encoded by tellurite resistance-conferring cluster "ter" from pathogenic Escherichia coli.

    Science.gov (United States)

    Valkovicova, Lenka; Vavrova, Silvia Minarikova; Mravec, Jozef; Grones, Jozef; Turna, Jan

    2013-12-01

    Gene cluster "ter" conferring high tellurite resistance has been identified in various pathogenic bacteria including Escherichia coli O157:H7. However, the precise mechanism as well as the molecular function of the respective gene products is unclear. Here we describe protein-protein association and localization analyses of four essential Ter proteins encoded by minimal resistance-conferring fragment (terBCDE) by means of recombinant expression. By using a two-plasmid complementation system we show that the overproduced single Ter proteins are not able to mediate tellurite resistance, but all Ter members play an irreplaceable role within the cluster. We identified several types of homotypic and heterotypic protein-protein associations among the Ter proteins by in vitro and in vivo pull-down assays and determined their cellular localization by cytosol/membrane fractionation. Our results strongly suggest that Ter proteins function involves their mutual association, which probably happens at the interface of the inner plasma membrane and the cytosol.

  1. Lipids in host-pathogen interactions: pathogens exploit the complexity of the host cell lipidome.

    Science.gov (United States)

    van der Meer-Janssen, Ynske P M; van Galen, Josse; Batenburg, Joseph J; Helms, J Bernd

    2010-01-01

    Lipids were long believed to have a structural role in biomembranes and a role in energy storage utilizing cellular lipid droplets and plasma lipoproteins. Research over the last decades has identified an additional role of lipids in cellular signaling, membrane microdomain organization and dynamics, and membrane trafficking. These properties make lipids an attractive target for pathogens to modulate host cell processes in order to allow their survival and replication. In this review we will summarize the often ingenious strategies of pathogens to modify the lipid homeostasis of host cells, allowing them to divert cellular processes. To this end pathogens take full advantage of the complexity of the lipidome. The examples are categorized in generalized and emerging principles describing the involvement of lipids in host-pathogen interactions. Several pathogens are described that simultaneously induce multiple changes in the host cell signaling and trafficking mechanisms. Elucidation of these pathogen-induced changes may have important implications for drug development. The emergence of high-throughput lipidomic techniques will allow the description of changes of the host cell lipidome at the level of individual molecular lipid species and the identification of lipid biomarkers.

  2. Protein recognition by a pattern-generating fluorescent molecular probe

    Science.gov (United States)

    Pode, Zohar; Peri-Naor, Ronny; Georgeson, Joseph M.; Ilani, Tal; Kiss, Vladimir; Unger, Tamar; Markus, Barak; Barr, Haim M.; Motiei, Leila; Margulies, David

    2017-12-01

    Fluorescent molecular probes have become valuable tools in protein research; however, the current methods for using these probes are less suitable for analysing specific populations of proteins in their native environment. In this study, we address this gap by developing a unimolecular fluorescent probe that combines the properties of small-molecule-based probes and cross-reactive sensor arrays (the so-called chemical 'noses/tongues'). On the one hand, the probe can detect different proteins by generating unique identification (ID) patterns, akin to cross-reactive arrays. On the other hand, its unimolecular scaffold and selective binding enable this ID-generating probe to identify combinations of specific protein families within complex mixtures and to discriminate among isoforms in living cells, where macroscopic arrays cannot access. The ability to recycle the molecular device and use it to track several binding interactions simultaneously further demonstrates how this approach could expand the fluorescent toolbox currently used to detect and image proteins.

  3. Aerobic vaginal pathogens and their sensitivity pattern.

    Science.gov (United States)

    Mumtaz, Shamim; Ahmad, Mumtaz; Aftab, Irum; Akhtar, Naeem; ul Hassan, Masood; Hamid, Abdul

    2008-01-01

    The vaginal flora is a complicated environment, containing dozens of microbiological species in variable quantities and relative proportions. The frequent cause of vaginal discharge is an infection or colonization with different microorganisms. Some pathologic conditions causing vaginitis are well defined yet, 7-72% of women with vaginitis may remain undiagnosed and such forms of abnormal vaginal flora neither considered as normal, nor can be called bacterial vaginosis have been termed as 'intermediate flora' and its management probably differ from that of bacterial vaginosis. It is of crucial importance in pregnant females at risk of preterm delivery. The present study has been conducted especially to elucidate this type of aerobic vaginal isolates and their culture and sensitivity towards currently used antibiotics. This study was conducted at the Microbiology Department of Fauji Foundation Hospital, Rawalpindi over a period of two years (April 2004-March 2006). One thousand, nine hundred and twenty three high vaginal swabs, both from indoor and outdoor patients were collected, cultured and their susceptibility to various antibiotics was determined. Significant growth was obtained in 731 samples. The highest frequency of infection (39.5%) was observed at 31-40 years followed by 41-50 years (35.8%). About 76% were from outdoor and 24% were from indoor patients. Staphylococcus aureus was the most prevalent vaginal pathogen at 11-60 yrs & with highest prevalence at 31-40 years followed by 41-50 years. It was a predominant pathogen in both indoor (35%) as well as outdoor (41.6%) patients, followed by enteric gram-negative bacilli and other gram-positive cocci. There were very few antibiotics among the conventionally available aminoglycosides, third generation cephalosporins, penicillin, quinolones, sulfonamides and tetracyclines possessing good sensitivity (> 80%) against any one the common aerobic vaginal pathogens. The effective chemotherapeutics agents belong to

  4. Molecular characterization of an adaptive response to alkylating agents in the opportunistic pathogen Aspergillus fumigatus.

    Science.gov (United States)

    O'Hanlon, Karen A; Margison, Geoffrey P; Hatch, Amy; Fitzpatrick, David A; Owens, Rebecca A; Doyle, Sean; Jones, Gary W

    2012-09-01

    An adaptive response to alkylating agents based upon the conformational change of a methylphosphotriester (MPT) DNA repair protein to a transcriptional activator has been demonstrated in a number of bacterial species, but this mechanism appears largely absent from eukaryotes. Here, we demonstrate that the human pathogen Aspergillus fumigatus elicits an adaptive response to sub-lethal doses of the mono-functional alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). We have identified genes that encode MPT and O(6)-alkylguanine DNA alkyltransferase (AGT) DNA repair proteins; deletions of either of these genes abolish the adaptive response and sensitize the organism to MNNG. In vitro DNA repair assays confirm the ability of MPT and AGT to repair methylphosphotriester and O(6)-methylguanine lesions respectively. In eukaryotes, the MPT protein is confined to a select group of fungal species, some of which are major mammalian and plant pathogens. The evolutionary origin of the adaptive response is bacterial and rooted within the Firmicutes phylum. Inter-kingdom horizontal gene transfer between Firmicutes and Ascomycete ancestors introduced the adaptive response into the Fungal kingdom. Our data constitute the first detailed characterization of the molecular mechanism of the adaptive response in a lower eukaryote and has applications for development of novel fungal therapeutics targeting this DNA repair system.

  5. Molecular characterization of an adaptive response to alkylating agents in the opportunistic pathogen Aspergillus fumigatus

    Science.gov (United States)

    O’Hanlon, Karen A.; Margison, Geoffrey P.; Hatch, Amy; Fitzpatrick, David A.; Owens, Rebecca A.; Doyle, Sean; Jones, Gary W.

    2012-01-01

    An adaptive response to alkylating agents based upon the conformational change of a methylphosphotriester (MPT) DNA repair protein to a transcriptional activator has been demonstrated in a number of bacterial species, but this mechanism appears largely absent from eukaryotes. Here, we demonstrate that the human pathogen Aspergillus fumigatus elicits an adaptive response to sub-lethal doses of the mono-functional alkylating agent N-methyl-N′-nitro-N-nitrosoguanidine (MNNG). We have identified genes that encode MPT and O6-alkylguanine DNA alkyltransferase (AGT) DNA repair proteins; deletions of either of these genes abolish the adaptive response and sensitize the organism to MNNG. In vitro DNA repair assays confirm the ability of MPT and AGT to repair methylphosphotriester and O6-methylguanine lesions respectively. In eukaryotes, the MPT protein is confined to a select group of fungal species, some of which are major mammalian and plant pathogens. The evolutionary origin of the adaptive response is bacterial and rooted within the Firmicutes phylum. Inter-kingdom horizontal gene transfer between Firmicutes and Ascomycete ancestors introduced the adaptive response into the Fungal kingdom. Our data constitute the first detailed characterization of the molecular mechanism of the adaptive response in a lower eukaryote and has applications for development of novel fungal therapeutics targeting this DNA repair system. PMID:22669901

  6. Cytological and molecular analysis of nonhost resistance in rice to wheat powdery mildew and leaf rust pathogens.

    Science.gov (United States)

    Cheng, Yulin; Yao, Juanni; Zhang, Hongchang; Huang, Lili; Kang, Zhensheng

    2015-07-01

    Cereal powdery mildews caused by Blumeria graminis and cereal rusts caused by Puccinia spp. are constant disease threats that limit the production of almost all important cereal crops. Rice is an intensively grown agricultural cereal that is atypical because of its immunity to all powdery mildew and rust fungi. We analyzed the nonhost interactions between rice and the wheat powdery mildew fungus B. graminis f. sp. tritici (Bgt) and the wheat leaf rust fungus Puccinia triticina (Ptr) to identify the basis of nonhost resistance (NHR) in rice against cereal powdery mildew and rust fungi at cytological and molecular levels. No visible symptoms were observed on rice leaves inoculated with Bgt or Ptr. Microscopic observations showed that both pathogens exhibited aberrant differentiation and significantly reduced penetration frequencies on rice compared to wheat. The development of Bgt and Ptr was also completely arrested at early infection stages in cases of successful penetration into rice leaves. Attempted infection of rice by Bgt and Ptr induced similar defense responses, including callose deposition, accumulation of reactive oxygen species, and hypersensitive response in rice epidermal and mesophyll cells, respectively. Furthermore, a set of defense-related genes were upregulated in rice against Bgt and Ptr infection. Rice is an excellent monocot model for genetic and molecular studies. Therefore, our results demonstrate that rice is a useful model to study the mechanisms of NHR to cereal powdery mildew and rust fungi, which provides useful information for the development of novel and durable strategies to control these important pathogens.

  7. ClinGen Pathogenicity Calculator: a configurable system for assessing pathogenicity of genetic variants.

    Science.gov (United States)

    Patel, Ronak Y; Shah, Neethu; Jackson, Andrew R; Ghosh, Rajarshi; Pawliczek, Piotr; Paithankar, Sameer; Baker, Aaron; Riehle, Kevin; Chen, Hailin; Milosavljevic, Sofia; Bizon, Chris; Rynearson, Shawn; Nelson, Tristan; Jarvik, Gail P; Rehm, Heidi L; Harrison, Steven M; Azzariti, Danielle; Powell, Bradford; Babb, Larry; Plon, Sharon E; Milosavljevic, Aleksandar

    2017-01-12

    The success of the clinical use of sequencing based tests (from single gene to genomes) depends on the accuracy and consistency of variant interpretation. Aiming to improve the interpretation process through practice guidelines, the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) have published standards and guidelines for the interpretation of sequence variants. However, manual application of the guidelines is tedious and prone to human error. Web-based tools and software systems may not only address this problem but also document reasoning and supporting evidence, thus enabling transparency of evidence-based reasoning and resolution of discordant interpretations. In this report, we describe the design, implementation, and initial testing of the Clinical Genome Resource (ClinGen) Pathogenicity Calculator, a configurable system and web service for the assessment of pathogenicity of Mendelian germline sequence variants. The system allows users to enter the applicable ACMG/AMP-style evidence tags for a specific allele with links to supporting data for each tag and generate guideline-based pathogenicity assessment for the allele. Through automation and comprehensive documentation of evidence codes, the system facilitates more accurate application of the ACMG/AMP guidelines, improves standardization in variant classification, and facilitates collaborative resolution of discordances. The rules of reasoning are configurable with gene-specific or disease-specific guideline variations (e.g. cardiomyopathy-specific frequency thresholds and functional assays). The software is modular, equipped with robust application program interfaces (APIs), and available under a free open source license and as a cloud-hosted web service, thus facilitating both stand-alone use and integration with existing variant curation and interpretation systems. The Pathogenicity Calculator is accessible at http

  8. Abundance of questing ticks and molecular evidence for pathogens in ticks in three parks of Emilia-Romagna region of Northern Italy

    Directory of Open Access Journals (Sweden)

    Sara Aureli

    2015-09-01

    Full Text Available Introduction and objective. Infectious and parasitic diseases transmitted by ticks, such as Lyme diseases, granulocytic anaplasmosis and piroplasmosis, have been frequently reported in Europe, with increasing attention to them as an emerging zoonotic problem. The presented study was performed to assess the distribution and the density of questing ticks in three regional parks of Emilia-Romagna region of Northern Italy, and to seek molecular evidence of potential human pathogens in tick populations. Materials and Methods. In the period April-October 2010, 8,139 questing ticks were collected: 6,734 larvae, 1,344 nymphs and only a few adults – 28 females and 33 males. The abundance of[i] Ixodes ricinus[/i] questing ticks was compared among different sampling sites and related to microclimate parameters. 1,544 out of 8,139 ticks were examined for the presence of pathogens: PCR was used to detect piroplasms DNA and Real time Taqman PCR for [i]Anaplasma phagocytophilum[/i] and [i]Borrelia burgdorferi[/i] s.l. Results. The predominant species was [i]I. ricinus[/i] (overall abundance 1,075.9/100 m[sup]2[/sup] ; more rarely, [i]Dermacentor marginatus[/i] (n = 37 – 0.45%, [i]Scaphixodes frontalis[/i] (n = 13 – 0.16%, [i]Hyalomma[/i] spp. (n = 6 – 0.07% and [i]Ixodes acuminatus[/i] (n = 3 – 0.04% were also found. 28 out of 324 (8.6% samples of ticks were PCR-positive for piroplasm DNA. 11 amplicons of 18S rRNA gene were identical to each other and had 100% identity with[i] Babesia[/i] EU1 ([i]Babesia venatorum[/i] using BLAST analysis. Real time Taqman PCR gave positive results for [i]A. phagocytophilum[/i] in 23 out of 292 samples (7.9%, and for [i]B. burgdorferi[/i] s.l. in 78 out of 292 samples (26.7%. [i]I. ricinu[/i]s was the only species found positive for pathogens by molecular analysis; 16 tick samples were co-infected with at least 2 pathogens. Discussion. The peak of nymph presence was in May, and the higher prevalence of pathogens

  9. Pathogenic human viruses in coastal waters

    Science.gov (United States)

    Griffin, Dale W.; Donaldson, Kim A.; Paul, J.H.; Rose, Joan B.

    2003-01-01

    This review addresses both historical and recent investigations into viral contamination of marine waters. With the relatively recent emergence of molecular biology-based assays, a number of investigations have shown that pathogenic viruses are prevalent in marine waters being impacted by sewage. Research has shown that this group of fecal-oral viral pathogens (enteroviruses, hepatitis A viruses, Norwalk viruses, reoviruses, adenoviruses, rotaviruses, etc.) can cause a broad range of asymptomatic to severe gastrointestinal, respiratory, and eye, nose, ear, and skin infections in people exposed through recreational use of the water. The viruses and the nucleic acid signature survive for an extended period in the marine environment. One of the primary concerns of public health officials is the relationship between the presence of pathogens and the recreational risk to human health in polluted marine environments. While a number of studies have attempted to address this issue, the relationship is still poorly understood. A contributing factor to our lack of progress in the field has been the lack of sensitive methods to detect the broad range of both bacterial and viral pathogens. The application of new and advanced molecular methods will continue to contribute to our current state of knowledge in this emerging and

  10. Pattern of distant recurrence according to the molecular subtypes in Korean women with breast cancer

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    Park Hyung Seok

    2012-01-01

    Full Text Available Abstract Background Distant recurrence is one of the most important risk factors in overall survival, and distant recurrence is related to a complex biologic interaction of seed and soil factors. The aim of the study was to investigate the association between the molecular subtypes and patterns of distant recurrence in patients with breast cancer. Methods In an investigation of 313 women with breast cancer who underwent surgery from 1994 and 2000, the expressions of estrogen and progestrone receptor (ER/PR, and human epithelial receptor-2 (HER2 were evaluated. The subtypes were defined as luminal-A, luminal-HER2, HER2-enriched, and triple negative breast cancer (TNBC according to ER, PR, and HER2 status. Results Bone was the most common site of distant recurrence. The incidence of first distant recurrence site was significantly different among the subtypes. Brain metastasis was more frequent in the luminal-HER2 and TNBC subtypes. In subgroup analysis, overall survival in patients with distant recurrence after 24 months after surgery was significantly different among the subtypes. Conclusions Organ-specific metastasis may depend on the molecular subtype of breast cancer. Tailored strategies against distant metastasis concerning the molecular subtypes in breast cancer may be considered.

  11. Molecular variability among isolates of Fusarium oxysporum associated with root rot disease of Agave tequilana.

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    Vega-Ramos, Karla L; Uvalle-Bueno, J Xavier; Gómez-Leyva, Juan F

    2013-04-01

    In this study, 115 isolates of Fusarium oxysporum from roots of Agave tequilana Weber cv azul plants and soil in commercial plantations in western Mexico were characterized using morphological and molecular methods. Genetic analyses of monosporic isolates included restriction enzyme analysis of rDNA (ARDRA) using HaeIII and HinfI, and genetic diversity was determined using Box-PCR molecular markers. Box-PCR analysis generated 14 groups. The groups correlated highly with the geographic location of the isolate and sample type. These results demonstrate the usefulness of ARDRA and Box-PCR techniques in the molecular characterization of the Fusarium genus for the discrimination of pathogenic isolates.

  12. A study of pattern recovery in recurrent correlation associative memories

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    Hancock, E.R.; Wilson, R.C.

    2003-01-01

    In this paper, we analyze the recurrent correlation associative memory (RCAM) model of Chiueh and Goodman. This is an associative memory in which stored binary memory patterns are recalled via an iterative update rule. The update of the individual pattern-bits is controlled by an excitation function, which takes as its arguement the inner product between the stored memory patterns and the input patterns. Our contribution is to analyze the dynamics of pattern recall when the input patterns are...

  13. Molecular Identification and Epidemiological Features of Human Adenoviruses Associated with Acute Respiratory Infections in Hospitalized Children in Southern China, 2012-2013.

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    Yi Chen

    Full Text Available Acute respiratory infections (ARI are the major worldwide health problem associated with high morbidity and mortality rates. Human adenovirus (HAdV is one of the most common pathogens associated with viral ARI, and thus calls for specific diagnosis and better understanding of the epidemiology and clinical characteristics.Total 4,130 children with ARI requiring hospitalization from 2012 to 2013 were retrospectively studied. Throat swab specimens were collected from each patient. Fluorescence Quantitative PCR was performed to detect adenovirus as well as other common ARI-related pathogens. The seven HAdV hypervariable regions (HVRs of the hexon gene from fifty-seven HAdVs-positive samples collected in the seasonal peaks were sequenced. Phylogenetic analysis of HVRs was also conducted to confirm the molecular types and genetic variation. In addition, epidemiological features and co-infection with other human respiratory pathogens were investigated and analyzed.Of 4,130 hospitalized pediatric patients tested, the positive rates of respiratory syncytial virus (RSV, Mycoplasma pneumoniae (MP, and HAdV were 13.7%, 13.2%, and 12.0%, respectively. The HAdV positive patients accounted for 7.9%, 17.2%, 17.5% and 10.7% in age groups <1, 1-3, 3-6 and 6-14 years, respectively. Eighty-four HAdV positive children were co-infected with other respiratory pathogens (84/495, 17.0%. The most common co-infection pathogens with HAdV were MP (57.1% and Human Bocavirus (HBoV (16.7%. The majority of HAdV infected patients were totally recovered (96.9%, 480/495; However, four (0.8% patients, who were previously healthy and at the age of 2 years or younger died of pneumonia. Seasonal peaks of HAdV infection occurred in the summer season of 2012 and 2013; the predominant HAdV type was HAdV-3 (70%, followed by HAdV-7 (28%. These epidemiological features were different from those in Northern China. The HAdV-55 was identified and reported for the first time in Guangzhou

  14. Reduced Set of Virulence Genes Allows High Accuracy Prediction of Bacterial Pathogenicity in Humans

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    Iraola, Gregorio; Vazquez, Gustavo; Spangenberg, Lucía; Naya, Hugo

    2012-01-01

    Although there have been great advances in understanding bacterial pathogenesis, there is still a lack of integrative information about what makes a bacterium a human pathogen. The advent of high-throughput sequencing technologies has dramatically increased the amount of completed bacterial genomes, for both known human pathogenic and non-pathogenic strains; this information is now available to investigate genetic features that determine pathogenic phenotypes in bacteria. In this work we determined presence/absence patterns of different virulence-related genes among more than finished bacterial genomes from both human pathogenic and non-pathogenic strains, belonging to different taxonomic groups (i.e: Actinobacteria, Gammaproteobacteria, Firmicutes, etc.). An accuracy of 95% using a cross-fold validation scheme with in-fold feature selection is obtained when classifying human pathogens and non-pathogens. A reduced subset of highly informative genes () is presented and applied to an external validation set. The statistical model was implemented in the BacFier v1.0 software (freely available at ), that displays not only the prediction (pathogen/non-pathogen) and an associated probability for pathogenicity, but also the presence/absence vector for the analyzed genes, so it is possible to decipher the subset of virulence genes responsible for the classification on the analyzed genome. Furthermore, we discuss the biological relevance for bacterial pathogenesis of the core set of genes, corresponding to eight functional categories, all with evident and documented association with the phenotypes of interest. Also, we analyze which functional categories of virulence genes were more distinctive for pathogenicity in each taxonomic group, which seems to be a completely new kind of information and could lead to important evolutionary conclusions. PMID:22916122

  15. PCR-based identification of selected pathogens associated with endodontic infections in deciduous and permanent teeth.

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    Cogulu, Dilsah; Uzel, Atac; Oncag, Ozant; Eronat, Cemal

    2008-09-01

    The aim of the present study was to evaluate the presence of the selected pathogens in samples from deciduous and permanent tooth root canals by using PCR method and to determine the association of these organisms with clinical symptoms. A total of 145 children, 5 to 13 years old, were involved in this study. The presence of selected pathogens (Actinomyces israelii, Candida albicans, Enterococcus faecalis, Fusobacterium nucleatum, Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia, Streptococcus intermedius, Treponema denticola, Parvimonas micra, Tannerella forsythensis, Enterococcus faecium, Prevotella melaninogenica) in infected root canals was studied using PCR. T. denticola (P = .012, .02) and E. faecalis (P = .012, .04) were highly associated with periapical radiolucency and previous pain, while P. gingivalis was associated with tenderness to percussion in both deciduous and permanent teeth (P = .01, .015). The results of the present study confirm that certain species of microorganisms are associated with clinical signs and symptoms of endodontic disease in both deciduous and permanent teeth.

  16. Association between sociodemographics factors and dietary patterns during pregnancy

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    Maria Beatriz Trindade De Castro

    2014-04-01

    Full Text Available OBJECTIVE: To investigate the association between socio-demographic factors and dietary patterns in pregnancy. METHODS: Cross-sectional study with baseline data from a cohort of 421 postpartum women aged 18 and 45 years resident in Rio de Janeiro, Brazil. Dietary intake was evaluated with a validated food frequency questionnaire at 15 days following delivery, having as time frame the second and third pregnancy trimesters. Dietary patterns were identified using factor analysis for principal components analysis. The association between socio-demographic factors and the identified dietary patterns was assessed with multiple linear regression analysis. RESULTS: Two dietary patterns were identified: i healthy: fruits; green vegetables; vegetables; fish; roots, corn and potato; milk and dairy and herbal tea mate, and negatively loadings for alcohol and coffee and ii mixed: rice; bean; flour and pasta; breads; cake and cookies; soda and juice; sugar and sweets; fatty foods; meats; chicken; and eggs. The linear regression showed that the income (β=0.0002; 95%CI: 0.0002-0.0004 and schooling (β=0.0491; 95%CI: 0.0264-0.0718 were positively associated with healthy pattern, and parity (β=-0.1044; 95%CI: -0.1665- -0.0423 and skin color (β=-0.3102; 95%CI: -0.5256- -0.0947 were negatively associated. Skin color (β=0.1647; 95%CI: 0.0378- 0.2916 and marital status (β=0.1065; 95%CI: 0.0062- 0.2067 were positively associated with mixed pattern and income (β=-0.0001; 95%CI:-0.0002- -0.0001 and schooling (β=-0.0281; 95%CI: -0.0417- -0.0146 were negatively associated. CONCLUSION: Socio-demographic factors such as income, schooling, skin color, marital status and parity were associated with dietary patterns in this sample of postpartum women residents in Rio de Janeiro.

  17. Community-associated urinary infections requiring hospitalization: risk factors, microbiological characteristics and patterns of antibiotic resistance.

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    Medina-Polo, J; Guerrero-Ramos, F; Pérez-Cadavid, S; Arrébola-Pajares, A; Sopeña-Sutil, R; Benítez-Sala, R; Jiménez-Alcaide, E; García-González, L; Alonso-Isa, M; Lara-Isla, A; Passas-Martínez, J B; Tejido-Sánchez, Á

    2015-03-01

    Although patients with urinary tract infections (UTIs) are usually managed as outpatients, a percentage of them requires hospitalization. To review risk factors and microbiological characteristics of community-associated UTIs (CAUTIs) requiring hospitalization has been our objective. A prospective observational study was carried out from November 2011 to December 2013. Incidence, microbiological characteristics and antibiotic resistance patterns in patients with CAUTIs that required hospitalization were analyzed. Risk factors (including diabetes mellitus, urolithiasis, urinary catheterization) and resistance rates of each pathogen were also analyzed. Four hundred and fifty seven patients were hospitalized in our department with CAUTI. The mean age was 56.2±19.85 years. Of them, 52.1% patients were women, 19.7% had urinary indwelling catheter and 11.4% have had a previous UTI. The most frequently isolated pathogens were Escherichia coli (60.6%), followed by Klebsiella (9.2%), Enterococcus (8.4%) and Pseudomonas (7.2%). Enterobacteriaceae other than E.coli were more prevalent in male and older patients. On the other side the most frequently isolated pathogen in patients with a previous UTI and a urinary catheter was Entercoccus. The resistance rates E. coli against ampicillin/amoxicillin + β lactamase inhibitor was 23.5%, against third-generation cephalosporins 16.6%, against fluoroquinolones 31.3% and 16.7% against aminoglycosides. 11.4% E. coli strains were producers of extended-spectrum Beta-lactamases (ESBL). Finally, the resistance rates of Enterococcus and Pseudomonas against quinolones were of 50.0% and 61.5%, respectively. CAUTIs that require hospitalization are most frequent in older age, male gender, and presence of urinary catheter, with urolithiasis and with previous episodes of UTI. These factors are also related to isolation of pathogens other than E. coli and higher resistance rates. Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All

  18. The elicitin-like glycoprotein, ELI025, is secreted by the pathogenic oomycete Pythium insidiosum and evades host antibody responses.

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    Tassanee Lerksuthirat

    Full Text Available Pythium insidiosum is a unique oomycete that can infect humans and animals. Patients with a P. insidiosum infection (pythiosis have high rates of morbidity and mortality. The pathogen resists conventional antifungal drugs. Information on the biology and pathogenesis of P. insidiosum is limited. Many pathogens secrete proteins, known as effectors, which can affect the host response and promote the infection process. Elicitins are secretory proteins and are found only in the oomycetes, primarily in Phytophthora and Pythium species. In plant-pathogenic oomycetes, elicitins function as pathogen-associated molecular pattern molecules, sterol carriers, and plant defense stimulators. Recently, we reported a number of elicitin-encoding genes from the P. insidiosum transcriptome. The function of elicitins during human infections is unknown. One of the P. insidiosum elicitin-encoding genes, ELI025, is highly expressed and up-regulated at body temperature. This study aims to characterize the biochemical, immunological, and genetic properties of the elicitin protein, ELI025. A 12.4-kDa recombinant ELI025 protein (rELI025 was expressed in Escherichia coli. Rabbit anti-rELI025 antibodies reacted strongly with the native ELI025 in P. insidiosum's culture medium. The detected ELI025 had two isoforms: glycosylated and non-glycosylated. ELI025 was not immunoreactive with sera from pythiosis patients. The region near the transcriptional start site of ELI025 contained conserved oomycete core promoter elements. In conclusion, ELI025 is a small, abundant, secreted glycoprotein that evades host antibody responses. ELI025 is a promising candidate for development of diagnostic and therapeutic targets for pythiosis.

  19. Detecting Release of Bacterial dsDNA into the Host Cytosol Using Fluorescence Microscopy.

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    Dreier, Roland Felix; Santos, José Carlos; Broz, Petr

    2018-01-01

    Recognition of pathogens by the innate immune system relies on germline-encoded pattern recognition receptors (PRRs) that recognize unique microbial molecules, so-called pathogen-associated molecular patterns (PAMPs). Nucleic acids and their derivatives are one of the most important groups of PAMPs, and are recognized by a number of surface-associated as well as cytosolic PRRs. Cyclic GMP-AMP synthase (cGAS) recognizes the presence of pathogen- or host-derived dsDNA in the cytosol and initiates type-I-IFN production. Here, we describe a methodology that allows for evaluating the association of cGAS with released bacterial dsDNA during Francisella novicida infection of macrophages, by fluorescence confocal microscopy. This method can be adapted to the study of cGAS-dependent responses elicited by other intracellular bacterial pathogens and in other cell types.

  20. The m.3291T>C mt-tRNALeu(UUR) mutation is definitely pathogenic and causes multisystem mitochondrial disease

    Science.gov (United States)

    Yarham, John W.; Blakely, Emma L.; Alston, Charlotte L.; Roberts, Mark E.; Ealing, John; Pal, Piyali; Turnbull, Douglass M.; McFarland, Robert; Taylor, Robert W.

    2013-01-01

    Mitochondrial tRNA point mutations are important causes of human disease, and have been associated with a diverse range of clinical phenotypes. Definitively proving the pathogenicity of any given mt-tRNA mutation requires combined molecular, genetic and functional studies. Subsequent evaluation of the mutation using a pathogenicity scoring system is often very helpful in concluding whether or not the mutation is causing disease. Despite several independent reports linking the m.3291T>C mutation to disease in humans, albeit in association with several different phenotypes, its pathogenicity remains controversial. A lack of conclusive functional evidence and an over-emphasis on the poor evolutionary conservation of the affected nucleotide have contributed to this controversy. Here we describe an adult patient who presented with deafness and lipomas and evidence of mitochondrial abnormalities in his muscle biopsy, who harbours the m.3291T > C mutation, providing conclusive evidence of pathogenicity through analysis of mutation segregation with cytochrome c oxidase (COX) deficiency in single muscle fibres, underlining the importance of performing functional studies when assessing pathogenicity. PMID:23273904

  1. Molecular detection of tick-borne pathogens in cattle from Southwestern Ethiopia.

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    Zerihun Hailemariam

    Full Text Available Tick-borne diseases (TBDs cause significant losses among livestock and impact the livelihoods of resource-poor farming communities worldwide. In Ethiopia, detailed studies on the epidemiology of tick-borne pathogens (TBPs in cattle using sensitive molecular detection methods are scarce. The objective of this study was to determine the prevalence and species composition of bovine TBPs of veterinary significance in local cattle populations. A comprehensive cross-sectional epidemiological study was conducted in cattle populations of Illubabor zone in Southwestern Ethiopia from June to August 2013. For this purpose, blood samples were collected from 392 cattle. A combination of polymerase chain reaction (PCR and a Reverse Line Blot (RLB hybridization assay was employed for the detection of TBPs in these samples. The PCR/RLB results of the 392 blood samples indicated a high overall prevalence of 96.9% for TBPs, including Theileria mutans (66.1%, Theileria orientalis (51.8%, Anaplasma sp. Omatjenne (25.5%, Anaplasma marginale (14.5%, Babesia bigemina (14.0% and Theileria velifera (13.0% and minor occurrences of Ehrlichia ruminantium (0.5% and Ehrlichia minasensis (0.26%. Moreover, three novel Anaplasma genotypes were detected in bovine blood samples. A phylogenetic analysis revealed that they most likely represent three, but at least two, new species. The prevalence of the three novel Anaplasma species, preliminary designated as Anaplasma sp. Hadesa, Anaplasma sp. Saso and Anaplasma sp. Dedessa, was 12.5%, 14.3% and 5.6%, respectively. Overall, a total of 227 cattle (57.9% were found to be co-infected with two or more TBPs simultaneously and 86 different species combinations were observed. The findings show a very high burden of infection of cattle with TBPs in Ethiopia. The high frequency of co-infections suggests that clinical manifestations might be complex. Further research is required to determine the pathogenicity, host cell types and vector of

  2. Heme Synthesis and Acquisition in Bacterial Pathogens.

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    Choby, Jacob E; Skaar, Eric P

    2016-08-28

    Bacterial pathogens require the iron-containing cofactor heme to cause disease. Heme is essential to the function of hemoproteins, which are involved in energy generation by the electron transport chain, detoxification of host immune effectors, and other processes. During infection, bacterial pathogens must synthesize heme or acquire heme from the host; however, host heme is sequestered in high-affinity hemoproteins. Pathogens have evolved elaborate strategies to acquire heme from host sources, particularly hemoglobin, and both heme acquisition and synthesis are important for pathogenesis. Paradoxically, excess heme is toxic to bacteria and pathogens must rely on heme detoxification strategies. Heme is a key nutrient in the struggle for survival between host and pathogen, and its study has offered significant insight into the molecular mechanisms of bacterial pathogenesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. The evolution of pathogenic trypanosomes

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    Jamie R. Stevens

    Full Text Available In the absence of a fossil record, the evolution of protozoa has until recently largely remained a matter for speculation. However, advances in molecular methods and phylogenetic analysis are now allowing interpretation of the "history written in the genes". This review focuses on recent progress in reconstruction of trypanosome phylogeny based on molecular data from ribosomal RNA, the miniexon and protein-coding genes. Sufficient data have now been gathered to demonstrate unequivocally that trypanosomes are monophyletic; the phylogenetic trees derived can serve as a framework to reinterpret the biology, taxonomy and present day distribution of trypanosome species, providing insights into the coevolution of trypanosomes with their vertebrate hosts and vectors. Different methods of dating the divergence of trypanosome lineages give rise to radically different evolutionary scenarios and these are reviewed. In particular, the use of one such biogeographically based approach provides new insights into the coevolution of the pathogens, Trypanosoma brucei and Trypanosoma cruzi, with their human hosts and the history of the diseases with which they are associated.

  4. Dietary patterns associated with overweight among Brazilian adolescents.

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    Borges, Camila Aparecida; Marchioni, Dirce Maria Lobo; Levy, Renata Bertazzi; Slater, Betzabeth

    2018-04-01

    The present study aims to identify the dietary patterns of adolescents and associate these patterns with overweight. We analyzed food-consumption data from 6784 adolescents in the age group 10-18 years old collected in the Household Budget Survey 2008-2009. Dietary patterns were assessed through exploratory factor analysis. Logistic regression models were used in order to associate dietary patterns with overweight. Four dietary patterns were recorded: Traditional Brazilian Pattern, Snacks Pattern, Fast Food Pattern, and the Milk, Fruit and Cereal Breakfast Pattern. Results were adjusted according to the sociodemographic variables and showed that the higher the adherence to Snacks (OR: 1.50 fifth quintile vs first (95% CI: 1.13, 1.99) p linear trend <0.001) and Fast Food patterns (OR: 1.55 fifth quintile vs first (95% CI = 1.12, 2.12) p linear trend <0.001), the higher the chances of becoming overweight. These data indicate that the local public health and nutrition policies focused on adolescents should be more attentive to the eating habits of this population in Brazil, since the current research related regular poor nutritional quality dietary patterns to increased overweight among adolescents. In addition, understanding adolescents' eating habits according to their dietary patterns may guide the development of healthy dietary recommendations based on the combination between food and food groups, rather than only on nutrients or nutritional adequacy. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Molecular characterization of reptile pathogens currently known as members of the chrysosporium anamorph of Nannizziopsis vriesii complex and relationship with some human-associated isolates.

    Science.gov (United States)

    Sigler, Lynne; Hambleton, Sarah; Paré, Jean A

    2013-10-01

    In recent years, the Chrysosporium anamorph of Nannizziopsis vriesii (CANV), Chrysosporium guarroi, Chrysosporium ophiodiicola, and Chrysosporium species have been reported as the causes of dermal or deep lesions in reptiles. These infections are contagious and often fatal and affect both captive and wild animals. Forty-nine CANV isolates from reptiles and six isolates from human sources were compared with N. vriesii based on their cultural characteristics and DNA sequence data. Analyses of the sequences of the internal transcribed spacer and small subunit of the nuclear ribosomal gene revealed that the reptile pathogens and human isolates belong in well-supported clades corresponding to three lineages that are distinct from all other taxa within the family Onygenaceae of the order Onygenales. One lineage represents the genus Nannizziopsis and comprises N. vriesii, N. guarroi, and six additional species encompassing isolates from chameleons and geckos, crocodiles, agamid and iguanid lizards, and humans. Two other lineages comprise the genus Ophidiomyces, with the species Ophidiomyces ophiodiicola occurring only in snakes, and Paranannizziopsis gen. nov., with three new species infecting squamates and tuataras. The newly described species are Nannizziopsis dermatitidis, Nannizziopsis crocodili, Nannizziopsis barbata, Nannizziopsis infrequens, Nannizziopsis hominis, Nannizziopsis obscura, Paranannizziopsis australasiensis, Paranannizziopsis californiensis, and Paranannizziopsis crustacea. Chrysosporium longisporum has been reclassified as Paranannizziopsis longispora. N. guarroi causes yellow fungus disease, a common infection in bearded dragons and green iguanas, and O. ophiodiicola is an emerging pathogen of captive and wild snakes. Human-associated species were not recovered from reptiles, and reptile-associated species were recovered only from reptiles, thereby mitigating concerns related to zoonosis.

  6. Genetic reprogramming of host cells by bacterial pathogens.

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    Tran Van Nhieu, Guy; Arbibe, Laurence

    2009-10-29

    During the course of infection, pathogens often induce changes in gene expression in host cells and these changes can be long lasting and global or transient and of limited amplitude. Defining how, when, and why bacterial pathogens reprogram host cells represents an exciting challenge that opens up the opportunity to grasp the essence of pathogenesis and its molecular details.

  7. Additional risk factors for infection by multidrug-resistant pathogens in healthcare-associated infection: a large cohort study

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    Cardoso Teresa

    2012-12-01

    Full Text Available Abstract Background There is a lack of consensus regarding the definition of risk factors for healthcare-associated infection (HCAI. The purpose of this study was to identify additional risk factors for HCAI, which are not included in the current definition of HCAI, associated with infection by multidrug-resistant (MDR pathogens, in all hospitalized infected patients from the community. Methods This 1-year prospective cohort study included all patients with infection admitted to a large, tertiary care, university hospital. Risk factors not included in the HCAI definition, and independently associated with MDR pathogen infection, namely MDR Gram-negative (MDR-GN and ESKAPE microorganisms (vancomycin-resistant Enterococcus faecium, methicillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella species, carbapenem-hydrolyzing Klebsiella pneumonia and MDR Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter species, were identified by logistic regression among patients admitted from the community (either with community-acquired or HCAI. Results There were 1035 patients with infection, 718 from the community. Of these, 439 (61% had microbiologic documentation; 123 were MDR (28%. Among MDR: 104 (85% had MDR-GN and 41 (33% had an ESKAPE infection. Independent risk factors associated with MDR and MDR-GN infection were: age (adjusted odds ratio (OR = 1.7 and 1.5, p = 0.001 and p = 0.009, respectively, and hospitalization in the previous year (between 4 and 12 months previously (adjusted OR = 2.0 and 1,7, p = 0.008 and p = 0.048, respectively. Infection by pathogens from the ESKAPE group was independently associated with previous antibiotic therapy (adjusted OR = 7.2, p p = 0.003. Patients with infection by MDR, MDR-GN and pathogens from the ESKAPE group had significantly higher rates of inadequate antibiotic therapy than those without (46% vs 7%, 44% vs 10%, 61% vs 15%, respectively, p

  8. Comparative genome analysis of pathogenic and non-pathogenic Clavibacter strains reveals adaptations to their lifestyle.

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    Załuga, Joanna; Stragier, Pieter; Baeyen, Steve; Haegeman, Annelies; Van Vaerenbergh, Johan; Maes, Martine; De Vos, Paul

    2014-05-22

    The genus Clavibacter harbors economically important plant pathogens infecting agricultural crops such as potato and tomato. Although the vast majority of Clavibacter strains are pathogenic, there is an increasing number of non-pathogenic isolates reported. Non-pathogenic Clavibacter strains isolated from tomato seeds are particularly problematic because they affect the current detection and identification tests for Clavibacter michiganensis subsp. michiganensis (Cmm), which is regulated with a zero tolerance in tomato seed. Their misidentification as pathogenic Cmm hampers a clear judgment on the seed quality and health. To get more insight in the genetic features linked to the lifestyle of these bacteria, a whole-genome sequence of the tomato seed-borne non-pathogenic Clavibacter LMG 26808 was determined. To gain a better understanding of the molecular determinants of pathogenicity, the genome sequence of LMG 26808 was compared with that of the pathogenic Cmm strain (NCPPB 382). The comparative analysis revealed that LMG 26808 does not contain plasmids pCM1 and pCM2 and also lacks the majority of important virulence factors described so far for pathogenic Cmm. This explains its apparent non-pathogenic nature in tomato plants. Moreover, the genome analysis of LMG 26808 detected sequences from a plasmid originating from a member of Enterobacteriaceae/Klebsiella relative. Genes received that way and coding for antibiotic resistance may provide a competitive advantage for survival of LMG 26808 in its ecological niche. Genetically, LMG 26808 was the most similar to the pathogenic Cmm NCPPB 382 but contained more mobile genetic elements. The genome of this non-pathogenic Clavibacter strain contained also a high number of transporters and regulatory genes. The genome sequence of the non-pathogenic Clavibacter strain LMG 26808 and the comparative analyses with other pathogenic Clavibacter strains provided a better understanding of the genetic bases of virulence and

  9. Caracterização fenotípica e molecular de genitores de feijão tipo carioca quanto à resistência a patógenos Phenotypic and molecular characterization of genitors of carioca-type common bean regarding their resistance to pathogens

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    Carlos Lasaro Pereira de Melo

    2008-04-01

    Full Text Available O objetivo deste estudo foi a caracterização fenotípica e molecular de 31 genótipos de feijão do tipo carioca, quanto à resistência aos patógenos da antracnose, ferrugem e mancha-angular. Foram realizadas inoculações com 13 patótipos de Colletotrichum lindemuthianum, dois de Uromyces appendiculatus e sete de Pseudocercospora griseola. Na caracterização molecular, foram utilizados cinco marcadores moleculares previamente identificados, ligados a diferentes alelos de resistência aos patógenos. Sete genótipos apresentaram resistência a 12 patótipos de C. lindemuthianum. Nove genótipos apresentaram resistência a cinco patótipos de P. griseola. Dez genótipos foram resistentes aos patótipos de U. appendiculatus. As linhagens VC 2, VC 3 e VC 5, além da Rudá-R (linhagem piramidada com cinco genes que conferem resistência a alguns patótipos de antracnose, ferrugem e mancha-angular, foram as que se destacaram quanto à resistência múltipla aos patógenos acima citados. Foi detectado polimorfismo molecular entre a maioria dos genótipos com a Rudá-R, o que indica a possibilidade de uso dos marcadores moleculares SCARF10, SCARY20, SCARAZ20, SCARH13 e OPX11.The present study aimed at the phenotypic and molecular characterization of 31 genotypes of the carioca-type common bean regarding the resistance to anthracnose, rust and angular leaf spot (ALS pathogens. Thirteen pathotypes of Colletotrichum lindemuthianum, two of Uromyces appendiculatus and seven of Pseudocercospora griseola were inoculated. In the molecular characterization, five molecular markers, identified in advance, and linked to the different alleles of pathogens' resistance, were used. Seven genotypes showed resistance to 12 pathotypes of C. lindemuthianum. Nine genotypes presented resistance to five pathotypes of P. griseola. Ten genotypes were resistant to the pathotypes of U. appendiculatus. The lines VC 2, VC 3 and VC 5, besides Rudá-R (line pyramided with five

  10. Bacterial genomics reveal the complex epidemiology of an emerging pathogen in arctic and boreal ungulates

    Science.gov (United States)

    Forde, Taya L.; Orsel, Karin; Zadoks, Ruth N.; Biek, Roman; Adams, Layne G.; Checkley, Sylvia L.; Davison, Tracy; De Buck, Jeroen; Dumond, Mathieu; Elkin, Brett T.; Finnegan, Laura; Macbeth, Bryan J.; Nelson, Cait; Niptanatiak, Amanda; Sather, Shane; Schwantje, Helen M.; van der Meer, Frank; Kutz, Susan J.

    2016-01-01

    Northern ecosystems are currently experiencing unprecedented ecological change, largely driven by a rapidly changing climate. Pathogen range expansion, and emergence and altered patterns of infectious disease, are increasingly reported in wildlife at high latitudes. Understanding the causes and consequences of shifting pathogen diversity and host-pathogen interactions in these ecosystems is important for wildlife conservation, and for indigenous populations that depend on wildlife. Among the key questions are whether disease events are associated with endemic or recently introduced pathogens, and whether emerging strains are spreading throughout the region. In this study, we used a phylogenomic approach to address these questions of pathogen endemicity and spread for Erysipelothrix rhusiopathiae, an opportunistic multi-host bacterial pathogen associated with recent mortalities in arctic and boreal ungulate populations in North America. We isolated E. rhusiopathiae from carcasses associated with large-scale die-offs of muskoxen in the Canadian Arctic Archipelago, and from contemporaneous mortality events and/or population declines among muskoxen in northwestern Alaska and caribou and moose in western Canada. Bacterial genomic diversity differed markedly among these locations; minimal divergence was present among isolates from muskoxen in the Canadian Arctic, while in caribou and moose populations, strains from highly divergent clades were isolated from the same location, or even from within a single carcass. These results indicate that mortalities among northern ungulates are not associated with a single emerging strain of E. rhusiopathiae, and that alternate hypotheses need to be explored. Our study illustrates the value and limitations of bacterial genomic data for discriminating between ecological hypotheses of disease emergence, and highlights the importance of studying emerging pathogens within the broader context of environmental and host factors.

  11. Insight of Genus Corynebacterium: Ascertaining the Role of Pathogenic and Non-pathogenic Species.

    Science.gov (United States)

    Oliveira, Alberto; Oliveira, Leticia C; Aburjaile, Flavia; Benevides, Leandro; Tiwari, Sandeep; Jamal, Syed B; Silva, Arthur; Figueiredo, Henrique C P; Ghosh, Preetam; Portela, Ricardo W; De Carvalho Azevedo, Vasco A; Wattam, Alice R

    2017-01-01

    This review gathers recent information about genomic and transcriptomic studies in the Corynebacterium genus, exploring, for example, prediction of pathogenicity islands and stress response in different pathogenic and non-pathogenic species. In addition, is described several phylogeny studies to Corynebacterium , exploring since the identification of species until biological speciation in one species belonging to the genus Corynebacterium . Important concepts associated with virulence highlighting the role of Pld protein and Tox gene. The adhesion, characteristic of virulence factor, was described using the sortase mechanism that is associated to anchorage to the cell wall. In addition, survival inside the host cell and some diseases, were too addressed for pathogenic corynebacteria, while important biochemical pathways and biotechnological applications retain the focus of this review for non-pathogenic corynebacteria. Concluding, this review broadly explores characteristics in genus Corynebacterium showing to have strong relevance inside the medical, veterinary, and biotechnology field.

  12. Associations between meal patterns, binge eating, and weight for Latinas.

    Science.gov (United States)

    Cachelin, Fary M; Thomas, Colleen; Vela, Alyssa; Gil-Rivas, Virginia

    2017-01-01

    Establishing a regular pattern of eating is a core element of treatment for binge eating, yet no research to date has examined meal patterns of Latina women. Compare eating patterns of Latinas who binge eat and those who do not, and examine associations between meal patterns and binge episodes, associated distress and concerns, and body mass index (BMI). One-hundred fifty-five Latinas [65 Binge Eating Disorder (BED), 22 Bulimia Nervosa (BN), 68 with no eating disorder] were assessed with the Eating Disorder Examination. There were no significant differences in eating patterns between groups. Breakfast was the least and dinner the most consumed meal. For the BED group: greater frequency of lunch consumption was associated with higher BMI while more frequent evening snacking was associated with lower BMI and with less weight importance; more frequent breakfast consumption, mid-morning snack consumption and total meals were associated with greater distress regarding binge eating. For the BN group, evening snack frequency was associated with less dietary restriction and more weight and shape concern; total snack frequency was associated with more weight concern. Regular meal eaters reported more episodes of binge eating than those who did not eat meals regularly. Associations with meal patterns differed by eating disorder diagnosis. Study findings mostly are not consistent with results from prior research on primarily White women. CBT treatments may need to be tailored to address the association between binge eating and regular meal consumption for Latinas. Culturally, appropriate modifications that address traditional eating patterns should be considered. © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2017; 50:32-39). © 2016 Wiley Periodicals, Inc.

  13. Pattern of pathogens and their sensitivity isolated from superficial surgical site infections in a tertiary care hospital

    International Nuclear Information System (INIS)

    Ali, S.A.; Tahir, S.M.; Shaikh, N.A.

    2009-01-01

    Infection is an important cause of morbidity and mortality in surgical patients. Rapidly emerging nosocomial pathogens and the problem of multi-drug resistance necessitates periodic review of isolation patterns and sensitivity in surgical practice. Surgical site infections (SSI) are defined as an infections that occurs at the incision site within thirty days after surgery. Objectives of the study were to determine the pattern of pathogens involved and their antibiotic sensitivity isolated from superficial surgical site infections in a teaching hospital. This observational study was conducted for 1 year from January 2008 to December 2008 in all 4 surgical units of Liaquat University Hospital Hyderabad which caters to patients from low socioeconomic status. Pus culture and sensitivity reports were collected prospectively from hospitalised patients who developed postoperative wound infection. The patients who developed fecal/biliary/urinary fistula or operated for malignancies, and with negative cultures were excluded from the study. Analysis was carried out using SPSS 10. During the study period 112 pus culture and sensitivity reports were analyzed. E. coli 68 (60.7%) was the most common organism isolated followed by Klebsiella 23 (20.5%). The least frequent organism was staph. Epidermidis 1 (0.9%). All isolates were sensitive to penicillin derivatives and carbapenem. Quinolones, Aminoglycosides and Monobactum were also showing some promise in our study. However, Cephalosporins were ineffective against most of the important isolates in our study. E. coli and klebsiella were the most important isolates form SSI in our study, and penicillin derivatives and carbapenem were showing 100% antibiotic sensitivity to all of the isolates. (author)

  14. Molecular Diagnosis of Pathogenic Sporothrix Species.

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    Anderson Messias Rodrigues

    2015-12-01

    Full Text Available Sporotrichosis is a chronic (subcutaneous infection caused by thermodimorphic fungi in the order, Ophiostomatales. These fungi are characterized by major differences in routes of transmission, host predilections, species virulence, and susceptibilities to antifungals. Sporothrix species emerge in the form of outbreaks. Large zoonoses and sapronoses are ongoing in Brazil and China, respectively. Current diagnostic methods based on morphology and physiology are inaccurate due to closely related phenotypes with overlapping components between pathogenic and non-pathogenic Sporothrix. There is a critical need for new diagnostic tools that are specific, sensitive, and cost-effective.We developed a panel of novel markers, based on calmodulin (CAL gene sequences, for the large-scale diagnosis and epidemiology of clinically relevant members of the Sporothrix genus, and its relative, Ophiostoma. We identified specific PCR-based markers for S. brasiliensis, S. schenckii, S. globosa, S. mexicana, S. pallida, and O. stenoceras. We employed a murine model of disseminated sporotrichosis to optimize a PCR assay for detecting Sporothrix in clinical specimens.Primer-BLAST searches revealed candidate sequences that were conserved within a single species. Species-specific primers showed no significant homology with human, mouse, or microorganisms outside the Sporothrix genus. The detection limit was 10-100 fg of DNA in a single round of PCR for identifying S. brasiliensis, S. schenckii, S. globosa, S. mexicana, and S. pallida. A simple, direct PCR assay, with conidia as a source of DNA, was effective for rapid, low-cost genotyping. Samples from a murine model of disseminated sporotrichosis confirmed the feasibility of detecting S. brasiliensis and S. schenckii DNA in spleen, liver, lungs, heart, brain, kidney, tail, and feces of infected animals.This PCR-based method could successfully detect and identify a single species in samples from cultures and from clinical

  15. Recent insights into the molecular mechanisms of the NLRP3 inflammasome activation [version 1; referees: 2 approved

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    Tomasz Próchnicki

    2016-06-01

    Full Text Available Inflammasomes are high-molecular-weight protein complexes that are formed in the cytosolic compartment in response to danger- or pathogen-associated molecular patterns. These complexes enable activation of an inflammatory protease caspase-1, leading to a cell death process called pyroptosis and to proteolytic cleavage and release of pro-inflammatory cytokines interleukin (IL-1β and IL-18. Along with caspase-1, inflammasome components include an adaptor protein, ASC, and a sensor protein, which triggers the inflammasome assembly in response to a danger signal. The inflammasome sensor proteins are pattern recognition receptors belonging either to the NOD-like receptor (NLR or to the AIM2-like receptor family. While the molecular agonists that induce inflammasome formation by AIM2 and by several other NLRs have been identified, it is not well understood how the NLR family member NLRP3 is activated. Given that NLRP3 activation is relevant to a range of human pathological conditions, significant attempts are being made to elucidate the molecular mechanism of this process. In this review, we summarize the current knowledge on the molecular events that lead to activation of the NLRP3 inflammasome in response to a range of K+ efflux-inducing danger signals. We also comment on the reported involvement of cytosolic Ca2+ fluxes on NLRP3 activation. We outline the recent advances in research on the physiological and pharmacological mechanisms of regulation of NLRP3 responses, and we point to several open questions regarding the current model of NLRP3 activation.

  16. The Geogenomic Mutational Atlas of Pathogens (GoMAP web system.

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    David P Sargeant

    Full Text Available We present a new approach for pathogen surveillance we call Geogenomics. Geogenomics examines the geographic distribution of the genomes of pathogens, with a particular emphasis on those mutations that give rise to drug resistance. We engineered a new web system called Geogenomic Mutational Atlas of Pathogens (GoMAP that enables investigation of the global distribution of individual drug resistance mutations. As a test case we examined mutations associated with HIV resistance to FDA-approved antiretroviral drugs. GoMAP-HIV makes use of existing public drug resistance and HIV protein sequence data to examine the distribution of 872 drug resistance mutations in ∼ 502,000 sequences for many countries in the world. We also implemented a broadened classification scheme for HIV drug resistance mutations. Several patterns for geographic distributions of resistance mutations were identified by visual mining using this web tool. GoMAP-HIV is an open access web application available at http://www.bio-toolkit.com/GoMap/project/

  17. Rapid identification and detection of pathogenic Fungi by padlock probes

    NARCIS (Netherlands)

    Tsui, C.K.M.; Wang, B.; Schoen, C.D.; Hamelin, R.C.

    2013-01-01

    Fungi are important pathogens of human diseases, as well as to agricultural crop and trees. Molecular diagnostics can detect diseases early, and improve identification accuracy and follow-up disease management. The use of padlock probe is effective to facilitate these detections and pathogen

  18. Molecular insights into the mechanisms of M-cell differentiation and transcytosis in the mucosa-associated lymphoid tissues.

    Science.gov (United States)

    Kimura, Shunsuke

    2018-01-01

    Microfold cells (M cells), which are located in the follicle-associated epithelium (FAE) covering mucosal lymphoid follicles, are specialized epithelial cells that initiate mucosal immune responses. These cells take luminal antigens and transport them via transcytosis across the FAE to the antigen-presenting cells underneath. Several intestinal pathogens exploit M cells as their portal for entry to invade the host and cause disease conditions. Recent studies have revealed that the uptake of antigens by M cells is essential for efficient antigen-specific IgA production and that this process likely maintains the homeostasis of mucosal tissues. The present article reviews recent advances in understanding the molecular mechanism of M-cell differentiation and describes the molecules expressed by M cells that are associated with antigen uptake and/or the transcytosis process. Current efforts to augment M-cell-mediated uptake for use in the development of effective mucosal vaccines are also discussed.

  19. Microbial and viral pathogens in colorectal cancer.

    LENUS (Irish Health Repository)

    Collins, Danielle

    2011-05-01

    The heterogenetic and sporadic nature of colorectal cancer has led to many epidemiological associations with causes of this disease. As our understanding of the underlying molecular processes in colorectal-cancer develops, the concept of microbial-epithelial interactions as an oncogenic trigger might provide a plausible hypothesis for the pathogenesis of colorectal cancer. By contrast with other cancers of the gastrointestinal tract (gastric carcinoma, mucosa-associated lymphoid-tissue lymphoma), a direct causal link between microbial infection (bacteria and viruses) and colorectal carcinoma has not been established. Studies support the involvement of these organisms in oncogenesis, however, in colorectal cancer, clinical data are lacking. Here, we discuss current evidence (both in vitro and clinical studies), and focus on a putative role for bacterial and viral pathogens as a cause of colorectal cancer.

  20. Microbial and viral pathogens in colorectal cancer.

    LENUS (Irish Health Repository)

    Collins, Danielle

    2012-02-01

    The heterogenetic and sporadic nature of colorectal cancer has led to many epidemiological associations with causes of this disease. As our understanding of the underlying molecular processes in colorectal-cancer develops, the concept of microbial-epithelial interactions as an oncogenic trigger might provide a plausible hypothesis for the pathogenesis of colorectal cancer. By contrast with other cancers of the gastrointestinal tract (gastric carcinoma, mucosa-associated lymphoid-tissue lymphoma), a direct causal link between microbial infection (bacteria and viruses) and colorectal carcinoma has not been established. Studies support the involvement of these organisms in oncogenesis, however, in colorectal cancer, clinical data are lacking. Here, we discuss current evidence (both in vitro and clinical studies), and focus on a putative role for bacterial and viral pathogens as a cause of colorectal cancer.

  1. Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation.

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    Martin Meyer

    2016-08-01

    Full Text Available We here compared pathogenic (p and non-pathogenic (np isolates of Entamoeba histolytica to identify molecules involved in the ability of this parasite to induce amoebic liver abscess (ALA-like lesions in two rodent models for the disease. We performed a comprehensive analysis of 12 clones (A1-A12 derived from a non-pathogenic isolate HM-1:IMSS-A and 12 clones (B1-B12 derived from a pathogenic isolate HM-1:IMSS-B. "Non-pathogenicity" included the induction of small and quickly resolved lesions while "pathogenicity" comprised larger abscess development that overstayed day 7 post infection. All A-clones were designated as non-pathogenic, whereas 4 out of 12 B-clones lost their ability to induce ALAs in gerbils. No correlation between ALA formation and cysteine peptidase (CP activity, haemolytic activity, erythrophagocytosis, motility or cytopathic activity was found. To identify the molecular framework underlying different pathogenic phenotypes, three clones were selected for in-depth transcriptome analyses. Comparison of a non-pathogenic clone A1np with pathogenic clone B2p revealed 76 differentially expressed genes, whereas comparison of a non-pathogenic clone B8np with B2p revealed only 19 differentially expressed genes. Only six genes were found to be similarly regulated in the two non-pathogenic clones A1np and B8np in comparison with the pathogenic clone B2p. Based on these analyses, we chose 20 candidate genes and evaluated their roles in ALA formation using the respective gene-overexpressing transfectants. We conclude that different mechanisms lead to loss of pathogenicity. In total, we identified eight proteins, comprising a metallopeptidase, C2 domain proteins, alcohol dehydrogenases and hypothetical proteins, that affect the pathogenicity of E. histolytica.

  2. Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation.

    Science.gov (United States)

    Meyer, Martin; Fehling, Helena; Matthiesen, Jenny; Lorenzen, Stephan; Schuldt, Kathrin; Bernin, Hannah; Zaruba, Mareen; Lender, Corinna; Ernst, Thomas; Ittrich, Harald; Roeder, Thomas; Tannich, Egbert; Lotter, Hannelore; Bruchhaus, Iris

    2016-08-01

    We here compared pathogenic (p) and non-pathogenic (np) isolates of Entamoeba histolytica to identify molecules involved in the ability of this parasite to induce amoebic liver abscess (ALA)-like lesions in two rodent models for the disease. We performed a comprehensive analysis of 12 clones (A1-A12) derived from a non-pathogenic isolate HM-1:IMSS-A and 12 clones (B1-B12) derived from a pathogenic isolate HM-1:IMSS-B. "Non-pathogenicity" included the induction of small and quickly resolved lesions while "pathogenicity" comprised larger abscess development that overstayed day 7 post infection. All A-clones were designated as non-pathogenic, whereas 4 out of 12 B-clones lost their ability to induce ALAs in gerbils. No correlation between ALA formation and cysteine peptidase (CP) activity, haemolytic activity, erythrophagocytosis, motility or cytopathic activity was found. To identify the molecular framework underlying different pathogenic phenotypes, three clones were selected for in-depth transcriptome analyses. Comparison of a non-pathogenic clone A1np with pathogenic clone B2p revealed 76 differentially expressed genes, whereas comparison of a non-pathogenic clone B8np with B2p revealed only 19 differentially expressed genes. Only six genes were found to be similarly regulated in the two non-pathogenic clones A1np and B8np in comparison with the pathogenic clone B2p. Based on these analyses, we chose 20 candidate genes and evaluated their roles in ALA formation using the respective gene-overexpressing transfectants. We conclude that different mechanisms lead to loss of pathogenicity. In total, we identified eight proteins, comprising a metallopeptidase, C2 domain proteins, alcohol dehydrogenases and hypothetical proteins, that affect the pathogenicity of E. histolytica.

  3. Toll-Like Receptors and Myocardial Inflammation

    Directory of Open Access Journals (Sweden)

    Yan Feng

    2011-01-01

    Full Text Available Toll-like receptors (TLRs are a member of the innate immune system. TLRs detect invading pathogens through the pathogen-associated molecular patterns (PAMPs recognition and play an essential role in the host defense. TLRs can also sense a large number of endogenous molecules with the damage-associated molecular patterns (DAMPs that are produced under various injurious conditions. Animal studies of the last decade have demonstrated that TLR signaling contributes to the pathogenesis of the critical cardiac conditions, where myocardial inflammation plays a prominent role, such as ischemic myocardial injury, myocarditis, and septic cardiomyopathy. This paper reviews the animal data on (1 TLRs, TLR ligands, and the signal transduction system and (2 the important role of TLR signaling in these critical cardiac conditions.

  4. Viral pathogen discovery

    Science.gov (United States)

    Chiu, Charles Y

    2015-01-01

    Viral pathogen discovery is of critical importance to clinical microbiology, infectious diseases, and public health. Genomic approaches for pathogen discovery, including consensus polymerase chain reaction (PCR), microarrays, and unbiased next-generation sequencing (NGS), have the capacity to comprehensively identify novel microbes present in clinical samples. Although numerous challenges remain to be addressed, including the bioinformatics analysis and interpretation of large datasets, these technologies have been successful in rapidly identifying emerging outbreak threats, screening vaccines and other biological products for microbial contamination, and discovering novel viruses associated with both acute and chronic illnesses. Downstream studies such as genome assembly, epidemiologic screening, and a culture system or animal model of infection are necessary to establish an association of a candidate pathogen with disease. PMID:23725672

  5. Dietary Patterns Are Associated with Stroke in Chinese Adults

    NARCIS (Netherlands)

    Li, Y.P.; He, Y.; Lai, J.Q.; Wang, D.; Zhang, J.; Fu, P.; Yang, X.G.; Qi, L.

    2011-01-01

    We recently featured Chinese dietary patterns that were associated with obesity, hyperglycemia, hypertension, and metabolic syndrome. In this study, we examined the association of those dietary patterns and risk of stroke among 26,276 Chinese adults aged >= 45 y by using data from the 2002 China

  6. A Broad-Spectrum Infection Diagnostic that Detects Pathogen-Associated Molecular Patterns (PAMPs in Whole Blood

    Directory of Open Access Journals (Sweden)

    Mark Cartwright

    2016-07-01

    Conclusion: The FcMBL ELLecSA-based PAMP assay offers a rapid, simple, sensitive and specific method for diagnosing infections, even when blood cultures are negative and antibiotic therapy has been initiated. It may help to triage patients with suspected systemic infections, and serve as a companion diagnostic to guide administration of emerging dialysis-like sepsis therapies.

  7. Steps toward broad-spectrum therapeutics: discovering virulence-associated genes present in diverse human pathogens

    Directory of Open Access Journals (Sweden)

    de Rochefort Anna

    2009-10-01

    Full Text Available Abstract Background New and improved antimicrobial countermeasures are urgently needed to counteract increased resistance to existing antimicrobial treatments and to combat currently untreatable or new emerging infectious diseases. We demonstrate that computational comparative genomics, together with experimental screening, can identify potential generic (i.e., conserved across multiple pathogen species and novel virulence-associated genes that may serve as targets for broad-spectrum countermeasures. Results Using phylogenetic profiles of protein clusters from completed microbial genome sequences, we identified seventeen protein candidates that are common to diverse human pathogens and absent or uncommon in non-pathogens. Mutants of 13 of these candidates were successfully generated in Yersinia pseudotuberculosis and the potential role of the proteins in virulence was assayed in an animal model. Six candidate proteins are suggested to be involved in the virulence of Y. pseudotuberculosis, none of which have previously been implicated in the virulence of Y. pseudotuberculosis and three have no record of involvement in the virulence of any bacteria. Conclusion This work demonstrates a strategy for the identification of potential virulence factors that are conserved across a number of human pathogenic bacterial species, confirming the usefulness of this tool.

  8. Lectins in human pathogenic fungi.

    Science.gov (United States)

    Gallegos, Belém; Martínez, Ruth; Pérez, Laura; Del Socorro Pina, María; Perez, Eduardo; Hernández, Pedro

    2014-01-01

    Lectins are carbohydrate-binding proteins widely distributed in nature. They constitute a highly diverse group of proteins consisting of many different protein families that are, in general, structurally unrelated. In the last few years, mushroom and other fungal lectins have attracted wide attention due to their antitumour, antiproliferative and immunomodulatory activities. The present mini-review provides concise information about recent developments in understanding lectins from human pathogenic fungi. A bibliographic search was performed in the Science Direct and PubMed databases, using the following keywords "lectin", "fungi", "human" and "pathogenic". Lectins present in fungi have been classified; however, the role played by lectins derived from human pathogenic fungi in infectious processes remains uncertain; thus, this is a scientific field requiring more research. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  9. Bacterial pathogen spectrum of acute diarrheal outpatients in an urbanized rural district in Southwest China

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    Yongming Zhou

    2018-05-01

    Full Text Available Objectives: To conduct a one-year pathogen surveillance of acute diarrheal disease based on outpatient clinics in township hospitals in rural Hongta District of Yunnan Province, China. Methods: Fecal specimens of acute diarrhea cases and relevant epidemiological information were collected. Salmonella, Shigella, Vibrio, Aeromonas, Plesiomonas shigelloides and diarrheogenic Escherichia coli (DEC were examined. Results: Among the 797 stool specimens sampled, 198 samples (24.8% were positive in pathogen isolation, and 223 strains were isolated. The order of isolation rates from high to low were DEC, Aeromonas, P. shigelloides, Salmonella, Shigella and Vibrio. The overall positive rate in middle school students and preschool children was relatively high; while the overall positive rate of less than 1-year-old infants and above 55 years olds was relatively low. The isolates were analyzed by pulsed-field gel electrophoresis (PFGE. Some cases had the same or very close onset time, and the isolates had similar PFGE patterns, suggesting a possible outbreak once occurred but was not detected by the current infectious disease reporting system. Conclusions: Pathogen infection and transmission in rapidly urbanized rural areas is a serious issue. There is a great need for a more sensitive and accurate mode of monitoring, reporting and outbreak identification of diarrheal disease. Keywords: Diarrheal disease, Diarrheogenic pathogen, Molecular typing, Surveillance, Bacterial pathogen

  10. Spectrum and antimicrobial susceptibility pattern of pathogens causing urinary tract infection experience in a tertiary care setting

    International Nuclear Information System (INIS)

    Amjad, A.; Mirza, I.A.; Abbasi, S.A.; Farwa, U.; Sattar, A.; Qureshi, Z.A.

    2012-01-01

    Objective: To determine the spectrum and antimicrobial susceptibility pattern of pathogens causing urinary tract infection from the samples received at AFIP Rawalpindi. Place and duration of study. The study was carried out at Department of Microbiology, Armed Forces Institute of Pathology from January 2010 to June 2010. Material and Method: This was descriptive cross-sectional study. A total of 500 bacterial isolates out of 2050 urine culture samples, for a period of six month were included in the study. Indentification was carried out by standard biochemical profile of the organisms. The antimicrobial susceptibilities of isolated organisms were performed by disk diffusion method as recommended by Clinical Laboratory Standard Institute. Results Out of the culture positive cases, gram-negative bacteria constituted the largest group with a total of 434 (87%) isolates, while gram-positive bacteria constituted only 44 (8.8%) isolates. E. coli was the most common isolate accounting for 63% of the total positive bacterial cultures followed by Klebsiella spp (9%) and P. aernginosa (7%). Susceptibility pattern of E. coli revealed that 96% of isolates were sensitive to imipenem, 91% to piperacillin-tazobactam and 87% to Nitrofurantoin. For Klebsiella spp, 86% of Isolates were susceptible to Imipenem and 71 % to piperacillin-tazobactam. As regards acinetobacter spp, 94% of Isolates were susceptible to piperacillin-tazobactam and 70 % to Imipenem an piperacilline-sulbactam. Antibiogram of P. aeruginosa revealed that 94% of isolates were sensitive to ceftazidime and 86% to imipenem. Nitrofurantoin was the most effective urinary antibiotic in case of enterococcus spp as 85% of isolates were susceptible to this compound. Conclusion: From the present study we conclude that E. coli was the predominant urinary pathogen in our set up. The antimicrobial susceptibility patterns of E. coli revealed that majority of isolates were susceptible to imipenem and piperacilline

  11. Successful strategy for the selection of new strawberry-associated rhizobacteria antagonistic to Verticillium wilt.

    Science.gov (United States)

    Berg, G; Kurze, S; Buchner, A; Wellington, E M; Smalla, K

    2000-12-01

    In order to isolate and characterize new strawberry-associated bacteria antagonistic to the soil-borne pathogenic fungus Verticillium dahliae Kleb., rhizobacterial populations from two different strawberry species, Greenish Strawberry (Fragaria viridis) and Garden Strawberry (F. x ananassa) obtained after plating onto King's B and glycerol-arginine agar, were screened for in vitro antagonism toward V. dahliae. The proportion of isolates with antifungal activity determined in in vitro assay against V. dahliae was higher for the Garden Strawberry than for the Greenish Strawberry. From 300 isolates, 20 isolates with strong antifungal activity were selected characterized by physiological profiling and molecular fingerprinting methods. Diversity among the isolates was characterized with molecular fingerprints using amplified ribosomal DNA restriction analysis (ARDRA) and the more discriminating BOX-PCR fingerprint method. The physiological profiles were well correlated with molecular fingerprinting pattern analysis. Significant reduction of Verticillium wilt by bacterial dipping bath treatment was shown in the greenhouse and in fields naturally infested by V. dahliae. The relative increase of yield ranged from 117% (Streptomyces albidoflavus S1) to 344% (Pseudomonas fluorescens P10) in greenhouse trials, and 113% (Streptomyces albidoflavus S1) to 247% (Pseudomonas fluorescens P6) in field trials. Evaluation resulted in the selection of three effective biocontrol agents (Pseudomonas fluorescens P6, P10, and Streptomyces diastatochromogenes S9) antagonistic to the Verticillium wilt pathogen.

  12. Intrinsic disorder in pathogen effectors: protein flexibility as an evolutionary hallmark in a molecular arms race.

    Science.gov (United States)

    Marín, Macarena; Uversky, Vladimir N; Ott, Thomas

    2013-09-01

    Effector proteins represent a refined mechanism of bacterial pathogens to overcome plants' innate immune systems. These modular proteins often manipulate host physiology by directly interfering with immune signaling of plant cells. Even if host cells have developed efficient strategies to perceive the presence of pathogenic microbes and to recognize intracellular effector activity, it remains an open question why only few effectors are recognized directly by plant resistance proteins. Based on in-silico genome-wide surveys and a reevaluation of published structural data, we estimated that bacterial effectors of phytopathogens are highly enriched in long-disordered regions (>50 residues). These structurally flexible segments have no secondary structure under physiological conditions but can fold in a stimulus-dependent manner (e.g., during protein-protein interactions). The high abundance of intrinsic disorder in effectors strongly suggests positive evolutionary selection of this structural feature and highlights the dynamic nature of these proteins. We postulate that such structural flexibility may be essential for (1) effector translocation, (2) evasion of the innate immune system, and (3) host function mimicry. The study of these dynamical regions will greatly complement current structural approaches to understand the molecular mechanisms of these proteins and may help in the prediction of new effectors.

  13. The role of the arbuscular mycorrhiza-associated rhizobacteria in the biocontrol of soilborne phyto pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Lioussanne, L.

    2010-07-01

    The mutualistic symbiosis of most land plants with arbuscular mycorrhizal (AM) fungi has been shown to favor mineral and water nutrition and to increase resistance to abiotic and biotic stresses. This review reports the main mechanisms involved in the control of the disease symptoms and of the intraradical proliferation of soilborne phytopathogens by root colonization with AM fungi, with a special emphasis on the role of the rhizobacteria shown to be specifically associated with the AM extraradical network and the mycorrhizosphere (the soil zone with particular characteristics under the influence of the root/AM association). The mycorrhizosphere would constitute an environment conducive to microorganisms antagonistic to pathogen proliferation. Moreover, attempts to identify rhizobacteria from AM structures and/or the mycorrhizosphere often lead to the isolation of organisms showing strong properties of antagonism on various soilborne pathogens. The ability of AM fungi to control soilborne diseases would be strongly related to their capacity to specifically stimulate the establishment of rhizobacteria unfavorable to pathogen development within the mycorrhizosphere before root infection. Current knowledge concerning the mechanisms involved in AM/rhizobacteria interactions are also described in this review. (Author) 101 refs.

  14. Molecular features of colorectal polyps presenting Kudo's type II mucosal crypt pattern: are they based on the same mechanism of tumorigenesis?

    Science.gov (United States)

    Shinmura, Kensuke; Konishi, Kazuo; Yamochi, Toshiko; Kubota, Yutaro; Yano, Yuichiro; Katagiri, Atsushi; Muramoto, Takashi; Kihara, Toshihiro; Tojo, Masayuki; Konda, Kenichi; Tagawa, Teppei; Yanagisawa, Fumito; Kogo, Mari; Makino, Reiko; Takimoto, Masafumi; Yoshida, Hitoshi

    2014-09-01

    The molecular features of serrated polyps (SPs) with hyperplastic crypt pattern, also called Kudo's type II observed by chromoendoscopy, were evaluated. The clinicopathological and molecular features of 114 SPs with a hyperplastic pit pattern detected under chromoendoscopy (five dysplastic SPs, 63 sessile serrated adenoma/polyps (SSA/Ps), 36 microvesicular hyperplastic polyps (MVHPs), and 10 goblet cell-rich hyperplastic polyps (GCHPs)) were examined. The frequency of KRAS and BRAF mutations and CpG island methylator phenotype (CIMP) were investigated. Dysplastic SPs and SSA/Ps were frequently located in the proximal colon compared to others (SSA/Ps vs. MVHPs or GCHPs, P GCHP (60 % for dysplastic SPs, 44 % for SSA/Ps, 47 % for MVHPs, and 0 % for GCHPs). The frequency of CIMP was higher in dysplastic SPs or SSA/Ps than in MVHPs or GCHPs (60 % for dysplastic SPs, 56 % for SSA/Ps, 32 % for MVHPs, and 10 % for GCHPs) (SSA/Ps vs. GCHP, P = 0.0068). When serrated neoplasias (SNs) and MVHPs were classified into proximal and distal lesions, the frequency of CIMP was significantly higher in the proximal compared to the distal SNs (64 % vs. 11 %, P = 0.0032). Finally, multivariate analysis showed that proximal location and BRAF mutation were significantly associated with an increased risk of CIMP. Distinct molecular features were observed between proximal and distal SPs with hyperplastic crypt pattern. Proximal MVHPs may develop more frequently through SSA/Ps to CIMP cancers than distal MVHPs.

  15. Enhancing crop innate immunity: new promising trends

    Directory of Open Access Journals (Sweden)

    Pin-Yao eHuang

    2014-11-01

    Full Text Available Plants are constantly exposed to potentially pathogenic microbes present in their surrounding environment. Due to the activation of the pattern-triggered immunity (PTI response that largely relies on accurate detection of pathogen- or microbe-associated molecular patterns by pattern-recognition receptors (PRRs, plants are resistant to the majority of potential pathogens. However, adapted pathogens may avoid recognition or repress plant PTI and resulting diseases significantly affect crop yield worldwide. PTI provides protection against a wide range of pathogens. Reinforcement of PTI through genetic engineering may thus generate crops with broad-spectrum field resistance. In this review, new approaches based on fundamental discoveries in PTI to improve crop immunity are discussed. Notably, we highlight recent studies describing the interfamily transfer of PRRs or key regulators of PTI signalling.

  16. PHIDIAS: a pathogen-host interaction data integration and analysis system

    OpenAIRE

    Xiang, Zuoshuang; Tian, Yuying; He, Yongqun

    2007-01-01

    The Pathogen-Host Interaction Data Integration and Analysis System (PHIDIAS) is a web-based database system that serves as a centralized source to search, compare, and analyze integrated genome sequences, conserved domains, and gene expression data related to pathogen-host interactions (PHIs) for pathogen species designated as high priority agents for public health and biological security. In addition, PHIDIAS allows submission, search and analysis of PHI genes and molecular networks curated ...

  17. MOLECULAR-GENETIC BASIS OF PHYSIOLOGY AND PATHOGENICITY OF COXIELLA BURNETII

    Directory of Open Access Journals (Sweden)

    Yu. A. Panpherova

    2012-01-01

    Full Text Available Abstract. The agent of Q-fever Coxiella burnetii is unusual intracellular pathogen which is possessed of biggest transporting and metabolic abilities in compare with microorganisms with similar parasitic strategy. It is supposed that different strains of the pathogen exist in various stages of pathological adaption and have different potential of virulence. The structure of C. burnetii genome, characteristics of metabolic routes, mechanisms of interaction with host cells and possible virulence factors are discussed in the review. The special attention is paid to Coxiella genotyping methods and possible correlations between genomic polymorphism of different strains and their virulence potential.

  18. Pathogenic factors associated with development of disseminated intravascular coagulopathy (DIC) in a tertiary academic hospital in South Africa.

    Science.gov (United States)

    Mayne, Elizabeth S; Mayne, Anthony L H; Louw, Susan J

    2018-01-01

    Disseminated intravascular coagulopathy (DIC) is a thrombotic microangiopathy arising from consumption of both coagulation factors and platelets. DIC is triggered by a number of clinical conditions including severe infection, trauma and obstetric complications. Early diagnosis and treatment of the underlying condition is paramount. A high clinical index of suspicion is needed to ensure that patients at risk of developing DIC are appropriately investigated. In order to establish the clinical conditions most frequently associated with DIC, we reviewed all DIC screens received at a tertiary hospital in Johannesburg, South Africa over a 1 year period. The commonest clinical condition associated with DIC in our population was infection with 84% of patients infected with an identified pathogen. The most frequently diagnosed pathogen was HIV followed by Mycobacterium tuberculosis and other bacterial infections. In the majority of cases, bacteria were isolated from blood cultures. In 47 patients, HIV was the only pathogen which could be isolated. A relative risk ratio of 2.73 and an odds ratio of 29.97 was attributed to HIV for development of a DIC. A malignancy was present in 51 of the patients of which approximately 60% had co-existing infection. No cause could be attributed in 30 patients. Infection was identified in the majority of the patients diagnosed with DIC in this study. HIV showed the highest relative risk ratio of all pathogens although previous studies have not suggested that HIV was strongly associated with DIC. In almost half of the HIV infected patients, there was no other pathogen isolated despite extensive investigation. This suggests that HIV has a strong association with the development of DIC, warranting further research into the relationship between HIV and disseminated microvascular thrombosis.

  19. Enteric bacterial pathogen detection in southern sea otters (Enhydra lutris nereis) is associated with coastal urbanization and freshwater runoff.

    Science.gov (United States)

    Miller, Melissa A; Byrne, Barbara A; Jang, Spencer S; Dodd, Erin M; Dorfmeier, Elene; Harris, Michael D; Ames, Jack; Paradies, David; Worcester, Karen; Jessup, David A; Miller, Woutrina A

    2010-01-01

    Although protected for nearly a century, California's sea otters have been slow to recover, in part due to exposure to fecally-associated protozoal pathogens like Toxoplasma gondii and Sarcocystis neurona. However, potential impacts from exposure to fecal bacteria have not been systematically explored. Using selective media, we examined feces from live and dead sea otters from California for specific enteric bacterial pathogens (Campylobacter, Salmonella, Clostridium perfringens, C. difficile and Escherichia coli O157:H7), and pathogens endemic to the marine environment (Vibrio cholerae, V. parahaemolyticus and Plesiomonas shigelloides). We evaluated statistical associations between detection of these pathogens in otter feces and demographic or environmental risk factors for otter exposure, and found that dead otters were more likely to test positive for C. perfringens, Campylobacter and V. parahaemolyticus than were live otters. Otters from more urbanized coastlines and areas with high freshwater runoff (near outflows of rivers or streams) were more likely to test positive for one or more of these bacterial pathogens. Other risk factors for bacterial detection in otters included male gender and fecal samples collected during the rainy season when surface runoff is maximal. Similar risk factors were reported in prior studies of pathogen exposure for California otters and their invertebrate prey, suggesting that land-sea transfer and/or facilitation of pathogen survival in degraded coastal marine habitat may be impacting sea otter recovery. Because otters and humans share many of the same foods, our findings may also have implications for human health.

  20. Molecular mechanisms of drug resistance in natural Leishmania populations vary with genetic background.

    Directory of Open Access Journals (Sweden)

    Saskia Decuypere

    Full Text Available The evolution of drug-resistance in pathogens is a major global health threat. Elucidating the molecular basis of pathogen drug-resistance has been the focus of many studies but rarely is it known whether a drug-resistance mechanism identified is universal for the studied pathogen; it has seldom been clarified whether drug-resistance mechanisms vary with the pathogen's genotype. Nevertheless this is of critical importance in gaining an understanding of the complexity of this global threat and in underpinning epidemiological surveillance of pathogen drug resistance in the field. This study aimed to assess the molecular and phenotypic heterogeneity that emerges in natural parasite populations under drug treatment pressure. We studied lines of the protozoan parasite Leishmania (L. donovani with differential susceptibility to antimonial drugs; the lines being derived from clinical isolates belonging to two distinct genetic populations that circulate in the leishmaniasis endemic region of Nepal. Parasite pathways known to be affected by antimonial drugs were characterised on five experimental levels in the lines of the two populations. Characterisation of DNA sequence, gene expression, protein expression and thiol levels revealed a number of molecular features that mark antimonial-resistant parasites in only one of the two populations studied. A final series of in vitro stress phenotyping experiments confirmed this heterogeneity amongst drug-resistant parasites from the two populations. These data provide evidence that the molecular changes associated with antimonial-resistance in natural Leishmania populations depend on the genetic background of the Leishmania population, which has resulted in a divergent set of resistance markers in the Leishmania populations. This heterogeneity of parasite adaptations provides severe challenges for the control of drug resistance in the field and the design of molecular surveillance tools for widespread

  1. Sub-30 nm patterning of molecular resists based on crosslinking through tip based oxidation

    Science.gov (United States)

    Lorenzoni, Matteo; Wagner, Daniel; Neuber, Christian; Schmidt, Hans-Werner; Perez-Murano, Francesc

    2018-06-01

    Oxidation Scanning Probe Lithography (o-SPL) is an established method employed for device patterning at the nanometer scale. It represents a feasible and inexpensive alternative to standard lithographic techniques such as electron beam lithography (EBL) and nanoimprint lithography (NIL). In this work we applied non-contact o-SPL to an engineered class of molecular resists in order to obtain crosslinking by electrochemical driven oxidation. By patterning and developing various resist formulas we were able to obtain a reliable negative tone resist behavior based on local oxidation. Under optimal conditions, directly written patterns can routinely reach sub-30 nm lateral resolution, while the final developed features result wider, approaching 50 nm width.

  2. Comparative analysis of lipopolysaccharides of pathogenic and intermediately pathogenic Leptospira species.

    Science.gov (United States)

    Patra, Kailash P; Choudhury, Biswa; Matthias, Michael M; Baga, Sheyenne; Bandyopadhya, Keya; Vinetz, Joseph M

    2015-10-30

    Lipopolysaccharides (LPS) are complex, amphipathic biomolecules that constitute the major surface component of Gram-negative bacteria. Leptospira, unlike other human-pathogenic spirochetes, produce LPS, which is fundamental to the taxonomy of the genus, involved in host-adaption and also the target of diagnostic antibodies. Despite its significance, little is known of Leptospira LPS composition and carbohydrate structure among different serovars. LPS from Leptospira interrogans serovar Copenhageni strain L1-130, a pathogenic species, and L. licerasiae serovar Varillal strain VAR 010, an intermediately pathogenic species, were studied. LPS prepared from aqueous and phenol phases were analyzed separately. L. interrogans serovar Copenhageni has additional sugars not found in L. licerasiae serovar Varillal, including fucose (2.7%), a high amount of GlcNAc (12.3%), and two different types of dideoxy HexNAc. SDS-PAGE indicated that L. interrogans serovar Copenhageni LPS had a far higher molecular weight and complexity than that of L. licerasiae serovar Varillal. Chemical composition showed that L. interrogans serovar Copenhageni LPS has an extended O-antigenic polysaccharide consisting of sugars, not present in L. licerasiae serovar Varillal. Arabinose, xylose, mannose, galactose and L-glycero-D-mannoheptose were detected in both the species. Fatty acid analysis by gas chromatography-mass spectrometry (GC-MS) showed the presence of hydroxypalmitate (3-OH-C16:0) only in L. interrogans serovar Copenhageni. Negative staining electron microscopic examination of LPS showed different filamentous morphologies in L. interrogans serovar Copenhageni vs. L. licerasiae serovar Varillal. This comparative biochemical analysis of pathogenic and intermediately pathogenic Leptospira LPS reveals important carbohydrate and lipid differences that underlie future work in understanding the mechanisms of host-adaptation, pathogenicity and vaccine development in leptospirosis.

  3. Meningococcal outer membrane vesicle composition-dependent activation of the innate immune response

    NARCIS (Netherlands)

    Zariri, Afshin; Beskers, Joep; van de Waterbeemd, Bas; Hamstra, Hendrik Jan; Bindels, Tim H E; van Riet, Elly; van Putten, Jos P M; van der Ley, Peter

    2016-01-01

    Meningococcal outer membrane vesicles (OMVs) have been extensively investigated and successfully implemented as vaccines. They contain pathogen associated molecular patterns including lipopolysaccharide (LPS), capable of triggering innate immunity. However, Neisseria meningitidis contains an

  4. Molecular characterisation of fungal endophytic morphospecies associated with the indigenous forest tree, Theobroma gileri, in Ecuador.

    Science.gov (United States)

    Thomas, Sarah E; Crozier, Jayne; Catherine Aime, M; Evans, Harry C; Holmes, Keith A

    2008-07-01

    Fungal endophytes were isolated from healthy stems and pods of Theobroma gileri, an alternative host of the frosty pod rot pathogen of cacao. Non-sporulating isolates were grouped into 46 different morphological species according to their colony morphology. Many of these morphospecies were assumed to be basidiomycetes and, therefore, were of particular interest. Basidiomycetous endophytes have received far less attention than ascomycetes and also have potential as biological control agents of the basidiomycetous pathogens of T. cacao: Moniliophthora roreri (frosty pod rot pathogen) and M. perniciosa (witches' broom disease). The morphospecies were further characterised by molecular analyses. Amplification of the nuLSU was undertaken for phylogenetic placement of these non-sporulating cultures and revealed a total of 31 different taxa of which 15 were basidiomycetes belonging to the class Agaricomycetes, and 16 ascomycetes primarily belonging to the Sordariomycetes.

  5. Molecular Epidemiology and Genetic Variation of Pathogenic Vibrio parahaemolyticus in Peru

    Science.gov (United States)

    Gavilan, Ronnie G.; Zamudio, Maria L.; Martinez-Urtaza, Jaime

    2013-01-01

    Vibrio parahaemolyticus is a foodborne pathogen that has become a public health concern at the global scale. The epidemiological significance of V. parahaemolyticus infections in Latin America received little attention until the winter of 1997 when cases related to the pandemic clone were detected in the region, changing the epidemic dynamics of this pathogen in Peru. With the aim to assess the impact of the arrival of the pandemic clone on local populations of pathogenic V. parahaemolyticus in Peru, we investigated the population genetics and genomic variation in a complete collection of non-pandemic strains recovered from clinical sources in Peru during the pre- and post-emergence periods of the pandemic clone. A total of 56 clinical strains isolated in Peru during the period 1994 to 2007, 13 strains from Chile and 20 strains from Asia were characterized by Multilocus Sequence Typing (MLST) and checked for the presence of Variable Genomic Regions (VGRs). The emergence of O3:K6 cases in Peru implied a drastic disruption of the seasonal dynamics of infections and a shift in the serotype dominance of pathogenic V. parahaemolyticus. After the arrival of the pandemic clone, a great diversity of serovars not previously reported was detected in the country, which supports the introduction of additional populations cohabitating with the pandemic group. Moreover, the presence of genomic regions characteristic of the pandemic clone in other non-pandemic strains may represent early evidence of genetic transfer from the introduced population to the local communities. Finally, the results of this study stress the importance of population admixture, horizontal genetic transfer and homologous recombination as major events shaping the structure and diversity of pathogenic V. parahaemolyticus. PMID:23696906

  6. Molecular Diagnosis of Pathogenic Sporothrix Species

    Science.gov (United States)

    Rodrigues, Anderson Messias; de Hoog, G. Sybren; de Camargo, Zoilo Pires

    2015-01-01

    Background Sporotrichosis is a chronic (sub)cutaneous infection caused by thermodimorphic fungi in the order, Ophiostomatales. These fungi are characterized by major differences in routes of transmission, host predilections, species virulence, and susceptibilities to antifungals. Sporothrix species emerge in the form of outbreaks. Large zoonoses and sapronoses are ongoing in Brazil and China, respectively. Current diagnostic methods based on morphology and physiology are inaccurate due to closely related phenotypes with overlapping components between pathogenic and non-pathogenic Sporothrix. There is a critical need for new diagnostic tools that are specific, sensitive, and cost-effective. Methodology We developed a panel of novel markers, based on calmodulin (CAL) gene sequences, for the large-scale diagnosis and epidemiology of clinically relevant members of the Sporothrix genus, and its relative, Ophiostoma. We identified specific PCR-based markers for S. brasiliensis, S. schenckii, S. globosa, S. mexicana, S. pallida, and O. stenoceras. We employed a murine model of disseminated sporotrichosis to optimize a PCR assay for detecting Sporothrix in clinical specimens. Results Primer-BLAST searches revealed candidate sequences that were conserved within a single species. Species-specific primers showed no significant homology with human, mouse, or microorganisms outside the Sporothrix genus. The detection limit was 10–100 fg of DNA in a single round of PCR for identifying S. brasiliensis, S. schenckii, S. globosa, S. mexicana, and S. pallida. A simple, direct PCR assay, with conidia as a source of DNA, was effective for rapid, low-cost genotyping. Samples from a murine model of disseminated sporotrichosis confirmed the feasibility of detecting S. brasiliensis and S. schenckii DNA in spleen, liver, lungs, heart, brain, kidney, tail, and feces of infected animals. Conclusions This PCR-based method could successfully detect and identify a single species in samples

  7. Antibiogram profile of pathogens isolated from processed cow meat ...

    African Journals Online (AJOL)

    ... the antibiotic resistance tests revealed varied, but interesting susceptibility patterns. Our findings does highlight the fact that there exist obvious vehicles for pathogenic bacteria proliferation within our abattoirs, and hence, the need for caution. Key words: Abattoirs, Bos taurus, Pathogenic bacteria, Antibiotics, Resistance ...

  8. Waterborne Pathogens: Detection Methods and Challenges

    Directory of Open Access Journals (Sweden)

    Flor Yazmín Ramírez-Castillo

    2015-05-01

    Full Text Available Waterborne pathogens and related diseases are a major public health concern worldwide, not only by the morbidity and mortality that they cause, but by the high cost that represents their prevention and treatment. These diseases are directly related to environmental deterioration and pollution. Despite the continued efforts to maintain water safety, waterborne outbreaks are still reported globally. Proper assessment of pathogens on water and water quality monitoring are key factors for decision-making regarding water distribution systems’ infrastructure, the choice of best water treatment and prevention waterborne outbreaks. Powerful, sensitive and reproducible diagnostic tools are developed to monitor pathogen contamination in water and be able to detect not only cultivable pathogens but also to detect the occurrence of viable but non-culturable microorganisms as well as the presence of pathogens on biofilms. Quantitative microbial risk assessment (QMRA is a helpful tool to evaluate the scenarios for pathogen contamination that involve surveillance, detection methods, analysis and decision-making. This review aims to present a research outlook on waterborne outbreaks that have occurred in recent years. This review also focuses in the main molecular techniques for detection of waterborne pathogens and the use of QMRA approach to protect public health.

  9. Next-Generation Sequencing for Infectious Disease Diagnosis and Management: A Report of the Association for Molecular Pathology.

    Science.gov (United States)

    Lefterova, Martina I; Suarez, Carlos J; Banaei, Niaz; Pinsky, Benjamin A

    2015-11-01

    Next-generation sequencing (NGS) technologies are increasingly being used for diagnosis and monitoring of infectious diseases. Herein, we review the application of NGS in clinical microbiology, focusing on genotypic resistance testing, direct detection of unknown disease-associated pathogens in clinical specimens, investigation of microbial population diversity in the human host, and strain typing. We have organized the review into three main sections: i) applications in clinical virology, ii) applications in clinical bacteriology, mycobacteriology, and mycology, and iii) validation, quality control, and maintenance of proficiency. Although NGS holds enormous promise for clinical infectious disease testing, many challenges remain, including automation, standardizing technical protocols and bioinformatics pipelines, improving reference databases, establishing proficiency testing and quality control measures, and reducing cost and turnaround time, all of which would be necessary for widespread adoption of NGS in clinical microbiology laboratories. Copyright © 2015 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  10. The sunflower downy mildew pathogen Plasmopara halstedii.

    Science.gov (United States)

    Gascuel, Quentin; Martinez, Yves; Boniface, Marie-Claude; Vear, Felicity; Pichon, Magalie; Godiard, Laurence

    2015-02-01

    Downy mildew of sunflower is caused by Plasmopara halstedii (Farlow) Berlese & de Toni. Plasmopara halstedii is an obligate biotrophic oomycete pathogen that attacks annual Helianthus species and cultivated sunflower, Helianthus annuus. Depending on the sunflower developmental stage at which infection occurs, the characteristic symptoms range from young seedling death, plant dwarfing, leaf bleaching and sporulation to the production of infertile flowers. Downy mildew attacks can have a great economic impact on sunflower crops, and several Pl resistance genes are present in cultivars to protect them against the disease. Nevertheless, some of these resistances have been overcome by the occurrence of novel isolates of the pathogen showing increased virulence. A better characterization of P. halstedii infection and dissemination mechanisms, and the identification of the molecular basis of the interaction with sunflower, is a prerequisite to efficiently fight this pathogen. This review summarizes what is currently known about P. halstedii, provides new insights into its infection cycle on resistant and susceptible sunflower lines using scanning electron and light microscopy imaging, and sheds light on the pathogenicity factors of P. halstedii obtained from recent molecular data. Kingdom Stramenopila; Phylum Oomycota; Class Oomycetes; Order Peronosporales; Family Peronosporaceae; Genus Plasmopara; Species Plasmopara halstedii. Sunflower seedling damping off, dwarfing of the plant, bleaching of leaves, starting from veins, and visible white sporulation, initially on the lower side of cotyledons and leaves. Plasmopara halstedii infection may severely impact sunflower seed yield. In spring, germination of overwintered sexual oospores leads to sunflower root infection. Intercellular hyphae are responsible for systemic plant colonization and the induction of disease symptoms. Under humid and fresh conditions, dissemination structures are produced by the pathogen on all

  11. Mnn10 Maintains Pathogenicity in Candida albicans by Extending α-1,6-Mannose Backbone to Evade Host Dectin-1 Mediated Antifungal Immunity.

    Directory of Open Access Journals (Sweden)

    Shi Qun Zhang

    2016-05-01

    Full Text Available The cell wall is a dynamic structure that is important for the pathogenicity of Candida albicans. Mannan, which is located in the outermost layer of the cell wall, has been shown to contribute to the pathogenesis of C. albicans, however, the molecular mechanism by which this occurs remains unclear. Here we identified a novel α-1,6-mannosyltransferase encoded by MNN10 in C. albicans. We found that Mnn10 is required for cell wall α-1,6-mannose backbone biosynthesis and polysaccharides organization. Deletion of MNN10 resulted in significant attenuation of the pathogenesis of C. albicans in a murine systemic candidiasis model. Inhibition of α-1,6-mannose backbone extension did not, however, impact the invasive ability of C. albicans in vitro. Notably, mnn10 mutant restored the invasive capacity in athymic nude mice, which further supports the notion of an enhanced host antifungal defense related to this backbone change. Mnn10 mutant induced enhanced Th1 and Th17 cell mediated antifungal immunity, and resulted in enhanced recruitment of neutrophils and monocytes for pathogen clearance in vivo. We also demonstrated that MNN10 could unmask the surface β-(1,3-glucan, a crucial pathogen-associated molecular pattern (PAMP of C. albicans recognized by host Dectin-1. Our results demonstrate that mnn10 mutant could stimulate an enhanced Dectin-1 dependent immune response of macrophages in vitro, including the activation of nuclear factor-κB, mitogen-activated protein kinase pathways, and secretion of specific cytokines such as TNF-α, IL-6, IL-1β and IL-12p40. In summary, our study indicated that α-1,6-mannose backbone is critical for the pathogenesis of C. albicans via shielding β-glucan from recognition by host Dectin-1 mediated immune recognition. Moreover, our work suggests that inhibition of α-1,6-mannose extension by Mnn10 may represent a novel modality to reduce the pathogenicity of C. albicans.

  12. [When history meets molecular medicine: molecular history of human tuberculosis].

    Science.gov (United States)

    Ottini, Laura; Falchetti, Mario

    2010-01-01

    Tuberculosis represents one of the humankind's most socially devastating diseases. Despite a long history of medical research and the development of effective therapies, this disease remains a global health danger even in the 21st century. Tuberculosis may cause death but infected people with effective immunity may remain healthy for years, suggesting long-term host-pathogen co-existence. Because of its antiquity, a supposed association with human settlements and the tendency to leave typical lesions on skeletal and mummified remains, tuberculosis has been the object of intensive multidisciplinary studies, including paleo-pathological research. During the past 10 years molecular paleo-pathology developed as a new scientific discipline allowing the study of ancient pathogens by direct detection of their DNA. In this work, we reviewed evidences for tuberculosis in ancient human remains, current methods for identifying ancient mycobacterial DNA and explored current theories of Mycobacterium tuberculosis evolution and their implications in the global development of tuberculosis looking into the past and present at the same time.

  13. Curriculum enactment patterns and associated factors from teachers' perspectives

    Science.gov (United States)

    Son, Ji-Won; Kim, Ok-Kyeong

    2016-12-01

    As part of a larger effort to improve teacher capacity for high-quality mathematics instruction, we investigated the factors that are associated with different enactment patterns at three levels: contextual (e.g., type and quality of textbook), individual (e.g., teacher knowledge), and teachers' opportunity-to-learn (e.g., professional development experiences). Analysis of 183 teachers' self-reports on their practices revealed three notable findings. First, the factors at the three levels were all found to be significantly related to the different patterns of enacted curriculum. However, the use of quality textbooks and the alignment of teachers' views and instructional goals with curriculum goals were found to be the two factors that are most strongly associated with the enactment pattern of high-level problems and high-level teacher questions in instruction. Furthermore, teachers with the enactment pattern of increasing lower cognitive demand of problems into higher ones tended to rate their curriculum knowledge higher than teachers with the enactment pattern of using low-level problems and teacher questions in their teaching. In particular, deviation from and dissatisfaction with their assigned low-quality textbooks were found to be critical factors that are associated with the enactment pattern of increasing lower cognitive demands of problems in instruction.

  14. Persistence of nasal colonization with human pathogenic bacteria and associated antimicrobial resistance in the German general population

    Directory of Open Access Journals (Sweden)

    R. Köck

    2016-01-01

    Full Text Available The nares represent an important bacterial reservoir for endogenous infections. This study aimed to assess the prevalence of nasal colonization by different important pathogens, the associated antimicrobial susceptibility and risk factors. We performed a prospective cohort study among 1878 nonhospitalized volunteers recruited from the general population in Germany. Participants provided nasal swabs at three time points (each separated by 4–6 months. Staphylococcus aureus, Enterobacteriaceae and important nonfermenters were cultured and subjected to susceptibility testing. Factors potentially influencing bacterial colonization patterns were assessed. The overall prevalence of S. aureus, Enterobacteriaceae and nonfermenters was 41.0, 33.4 and 3.7%, respectively. Thirteen participants (0.7% were colonized with methicillin-resistant S. aureus. Enterobacteriaceae were mostly (>99% susceptible against ciprofloxacin and carbapenems (100%. Extended-spectrum β-lactamase–producing isolates were not detected among Klebsiella oxytoca, Klebsiella pneumoniae and Escherichia coli. Several lifestyle- and health-related factors (e.g. household size, travel, livestock density of the residential area or occupational livestock contact, atopic dermatitis, antidepressant or anti-infective drugs were associated with colonization by different microorganisms. This study unexpectedly demonstrated high nasal colonization rates with Enterobacteriaceae in the German general population, but rates of antibiotic resistance were low. Methicillin-resistant S. aureus carriage was rare but highly associated with occupational livestock contact.

  15. Molecular network, pathway, and functional analysis of time-dependent gene changes associated with pancreatic cancer susceptibility to oncolytic vaccinia virotherapy

    Directory of Open Access Journals (Sweden)

    Dana Haddad

    2016-01-01

    Conclusions: Our study reveals the ability to assess time-dependent changes in gene expression patterns in pancreatic cancer cells associated with infection and susceptibility to vaccinia viruses. This suggests that molecular assays may be useful to develop safer and more efficacious oncolyticvirotherapies and support the idea that these treatments may target pathways implicated in pancreatic cancer resistance to conventional therapies.

  16. Recent insights into host-pathogen interaction in white spot syndrome virus infected penaeid shrimp.

    Science.gov (United States)

    Shekhar, M S; Ponniah, A G

    2015-07-01

    Viral disease outbreaks are a major concern impeding the development of the shrimp aquaculture industry. The viral disease due to white spot syndrome virus (WSSV) observed in early 1990s still continues unabated affecting the shrimp farms and cause huge economic loss to the shrimp aquaculture industry. In the absence of effective therapeutics to control WSSV, it is important to understand viral pathogenesis and shrimp response to WSSV at the molecular level. Identification and molecular characterization of WSSV proteins and receptors may facilitate in designing and development of novel therapeutics and antiviral drugs that may inhibit viral replication. Investigations into host-pathogen interactions might give new insights to viral infectivity, tissue tropism and defence mechanism elicited in response to WSSV infection. However, due to the limited information on WSSV gene function and host immune response, the signalling pathways which are associated in shrimp pathogen interaction have also not been elucidated completely. In the present review, the focus is on those shrimp proteins and receptors that are potentially involved in virus infection or in the defence mechanism against WSSV. In addition, the major signalling pathways involved in the innate immune response and the role of apoptosis in host-pathogen interaction is discussed. © 2014 John Wiley & Sons Ltd.

  17. Overexpression of Rice Wall-Associated Kinase 25 (OsWAK25) Alters Resistance to Bacterial and Fungal Pathogens

    Science.gov (United States)

    Harkenrider, Mitch; Sharma, Rita; De Vleesschauwer, David; Tsao, Li; Zhang, Xuting; Chern, Mawsheng; Canlas, Patrick; Zuo, Shimin; Ronald, Pamela C.

    2016-01-01

    Wall-associated kinases comprise a sub-family of receptor-like kinases that function in plant growth and stress responses. Previous studies have shown that the rice wall-associated kinase, OsWAK25, interacts with a diverse set of proteins associated with both biotic and abiotic stress responses. Here, we show that wounding and BTH treatments induce OsWAK25 transcript expression in rice. We generated OsWAK25 overexpression lines and show that these lines exhibit a lesion mimic phenotype and enhanced expression of rice NH1 (NPR1 homolog 1), OsPAL2, PBZ1 and PR10. Furthermore, these lines show resistance to the hemibiotrophic pathogens, Xanthomonas oryzae pv. oryzae (Xoo) and Magnaporthe oryzae, yet display increased susceptibility to necrotrophic fungal pathogens, Rhizoctonia solani and Cochliobolus miyabeanus. PMID:26795719

  18. Heme as a danger molecule in pathogen recognition.

    Science.gov (United States)

    Wegiel, Barbara; Hauser, Carl J; Otterbein, Leo E

    2015-12-01

    Appropriate control of redox mechanisms are critical for and effective innate immune response, which employs multiple cell types, receptors and molecules that recognize danger signals when they reach the host. Recognition of pathogen-associated pattern molecules (PAMPs) is a fundamental host survival mechanism for efficient elimination of invading pathogens and resolution of the infection and inflammation. In addition to PAMPs, eukaryotic cells contain a plethora of intracellular molecules that are normally secured within the confines of the plasma membrane, but if liberated and encountered in the extracellular milieu can provoke rapid cell activation. These are known as Alarmins or Danger-Associated Molecular Patterns (DAMPs) and can be released actively by cells or passively as a result of sterile cellular injury after trauma, ischemia, or toxin-induced cell rupture. Both PAMPs and DAMPs are recognized by a series of cognate receptors that increase the generation of free radicals and activate specific signaling pathways that result in regulation of a variety of stress response, redox sensitive genes. Multiple mediators released, as cells die include, but are not limited to ATP, hydrogen peroxide, heme, formyl peptides, DNA or mitochondria provide the second signal to amplify immune responses. In this review, we will focus on how sterile and infective stimuli activate the stress response gene heme oxygenase-1 (Hmox1, HO-1), a master gene critical to an appropriate host response that is now recognized as one with enormous therapeutic potential. HO-1 gene expression is regulated in large part by redox-sensitive proteins including but not limited to nrf2. Both PAMPs and DAMPs increase the activation of nrf2 and HO-1. Heme is a powerful pro-oxidant and as such should be qualified as a DAMP. With its degradation by HO-1a molecule of carbon monoxide (CO) is generated that in turn serves as a bioactive signaling molecule. PAMPs such as bacterial endotoxin activate HO-1

  19. The Top 10 oomycete pathogens in molecular plant pathology.

    Science.gov (United States)

    Kamoun, Sophien; Furzer, Oliver; Jones, Jonathan D G; Judelson, Howard S; Ali, Gul Shad; Dalio, Ronaldo J D; Roy, Sanjoy Guha; Schena, Leonardo; Zambounis, Antonios; Panabières, Franck; Cahill, David; Ruocco, Michelina; Figueiredo, Andreia; Chen, Xiao-Ren; Hulvey, Jon; Stam, Remco; Lamour, Kurt; Gijzen, Mark; Tyler, Brett M; Grünwald, Niklaus J; Mukhtar, M Shahid; Tomé, Daniel F A; Tör, Mahmut; Van Den Ackerveken, Guido; McDowell, John; Daayf, Fouad; Fry, William E; Lindqvist-Kreuze, Hannele; Meijer, Harold J G; Petre, Benjamin; Ristaino, Jean; Yoshida, Kentaro; Birch, Paul R J; Govers, Francine

    2015-05-01

    Oomycetes form a deep lineage of eukaryotic organisms that includes a large number of plant pathogens which threaten natural and managed ecosystems. We undertook a survey to query the community for their ranking of plant-pathogenic oomycete species based on scientific and economic importance. In total, we received 263 votes from 62 scientists in 15 countries for a total of 33 species. The Top 10 species and their ranking are: (1) Phytophthora infestans; (2, tied) Hyaloperonospora arabidopsidis; (2, tied) Phytophthora ramorum; (4) Phytophthora sojae; (5) Phytophthora capsici; (6) Plasmopara viticola; (7) Phytophthora cinnamomi; (8, tied) Phytophthora parasitica; (8, tied) Pythium ultimum; and (10) Albugo candida. This article provides an introduction to these 10 taxa and a snapshot of current research. We hope that the list will serve as a benchmark for future trends in oomycete research. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  20. Histone deacetylases: revealing the molecular base of dimorphism in pathogenic fungi

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    Alberto Elías-Villalobos

    2015-11-01

    Full Text Available Fungi, as every living organism, interact with the external world and have to adapt to its fluctuations. For pathogenic fungi, such interaction involves adapting to the hostile environment of their host. Survival depends on the capacity of fungi to detect and respond to external stimuli, which is achieved through a tight and efficient genetic control. Chromatin modifications represent a well-known layer of regulation that controls gene expression in response to environmental signals. However, less is known about the chromatin modifications that are involved in fungal virulence and the specific cues and signalling pathways that target chromatin modifications to specific genes. In a recently published study, our research group identified one such regulatory pathway. We demonstrated that the histone deacetylase (HDAC Hos2 is involved in yeast-to-hyphal transition (dimorphism and it is associated with the virulence of the maize pathogen Ustilago maydis, the causative agent of smut disease in corn. Hos2 activates mating-type genes by directly binding to their gene bodies. Furthermore, Hos2 acts downstream of the nutrient-sensing cyclic AMP-Protein Kinase A pathway. We also found that another HDAC, Clr3, contributes to this regulation, possibly in cooperation with Hos2. As a whole, our data suggest that there is a direct link between changes in the environment and acetylation of nucleosomes within certain genes. We propose that histone acetylation is critical to the proper timing and induction of transcription of the genes encoding factors that coordinate changes in morphology with pathogenesis.

  1. Transcriptome analysis of the fungal pathogen Fusarium oxysporum f. sp. medicaginis during colonisation of resistant and susceptible Medicago truncatula hosts identifies differential pathogenicity profiles and novel candidate effectors.

    Science.gov (United States)

    Thatcher, Louise F; Williams, Angela H; Garg, Gagan; Buck, Sally-Anne G; Singh, Karam B

    2016-11-03

    Pathogenic members of the Fusarium oxysporum species complex are responsible for vascular wilt disease on many important crops including legumes, where they can be one of the most destructive disease causing necrotrophic fungi. We previously developed a model legume-infecting pathosystem based on the reference legume Medicago truncatula and a pathogenic F. oxysporum forma specialis (f. sp.) medicaginis (Fom). To dissect the molecular pathogenicity arsenal used by this root-infecting pathogen, we sequenced its transcriptome during infection of a susceptible and resistant host accession. High coverage RNA-Seq of Fom infected root samples harvested from susceptible (DZA315) or resistant (A17) M. truncatula seedlings at early or later stages of infection (2 or 7 days post infection (dpi)) and from vegetative (in vitro) samples facilitated the identification of unique and overlapping sets of in planta differentially expressed genes. This included enrichment, particularly in DZA315 in planta up-regulated datasets, for proteins associated with sugar, protein and plant cell wall metabolism, membrane transport, nutrient uptake and oxidative processes. Genes encoding effector-like proteins were identified, including homologues of the F. oxysporum f. sp. lycopersici Secreted In Xylem (SIX) proteins, and several novel candidate effectors based on predicted secretion, small protein size and high in-planta induced expression. The majority of the effector candidates contain no known protein domains but do share high similarity to predicted proteins predominantly from other F. oxysporum ff. spp. as well as other Fusaria (F. solani, F. fujikori, F. verticilloides, F. graminearum and F. pseudograminearum), and from another wilt pathogen of the same class, a Verticillium species. Overall, this suggests these novel effector candidates may play important roles in Fusaria and wilt pathogen virulence. Combining high coverage in planta RNA-Seq with knowledge of fungal pathogenicity

  2. Enteric bacterial pathogen detection in southern sea otters (Enhydra lutris nereis) is associated with coastal urbanization and freshwater runoff

    Science.gov (United States)

    Miller, Melissa A.; Byrne, Barbara A.; Jang, Spencer S.; Dodd, Erin M.; Dorfmeier, Elene; Harris, Michael D.; Ames, Jack; Paradies, David; Worcester, Karen; Jessup, David A.; Miller, Woutrina A.

    2009-01-01

    Although protected for nearly a century, California’s sea otters have been slow to recover, in part due to exposure to fecally-associated protozoal pathogens like Toxoplasma gondii and Sarcocystis neurona. However, potential impacts from exposure to fecal bacteria have not been systematically explored. Using selective media, we examined feces from live and dead sea otters from California for specific enteric bacterial pathogens (Campylobacter, Salmonella, Clostridium perfringens, C. difficile and Escherichia coli O157:H7), and pathogens endemic to the marine environment (Vibrio cholerae, V. parahaemolyticus and Plesiomonas shigelloides). We evaluated statistical associations between detection of these pathogens in otter feces and demographic or environmental risk factors for otter exposure, and found that dead otters were more likely to test positive for C. perfringens, Campylobacter and V. parahaemolyticus than were live otters. Otters from more urbanized coastlines and areas with high freshwater runoff (near outflows of rivers or streams) were more likely to test positive for one or more of these bacterial pathogens. Other risk factors for bacterial detection in otters included male gender and fecal samples collected during the rainy season when surface runoff is maximal. Similar risk factors were reported in prior studies of pathogen exposure for California otters and their invertebrate prey, suggesting that land-sea transfer and/or facilitation of pathogen survival in degraded coastal marine habitat may be impacting sea otter recovery. Because otters and humans share many of the same foods, our findings may also have implications for human health. PMID:19720009

  3. Pathogenicity island mobility and gene content.

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Kelly Porter

    2013-10-01

    Key goals towards national biosecurity include methods for analyzing pathogens, predicting their emergence, and developing countermeasures. These goals are served by studying bacterial genes that promote pathogenicity and the pathogenicity islands that mobilize them. Cyberinfrastructure promoting an island database advances this field and enables deeper bioinformatic analysis that may identify novel pathogenicity genes. New automated methods and rich visualizations were developed for identifying pathogenicity islands, based on the principle that islands occur sporadically among closely related strains. The chromosomally-ordered pan-genome organizes all genes from a clade of strains; gaps in this visualization indicate islands, and decorations of the gene matrix facilitate exploration of island gene functions. A %E2%80%9Clearned phyloblocks%E2%80%9D method was developed for automated island identification, that trains on the phylogenetic patterns of islands identified by other methods. Learned phyloblocks better defined termini of previously identified islands in multidrug-resistant Klebsiella pneumoniae ATCC BAA-2146, and found its only antibiotic resistance island.

  4. Signatures of environmental genetic adaptation pinpoint pathogens as the main selective pressure through human evolution.

    Directory of Open Access Journals (Sweden)

    Matteo Fumagalli

    2011-11-01

    Full Text Available Previous genome-wide scans of positive natural selection in humans have identified a number of non-neutrally evolving genes that play important roles in skin pigmentation, metabolism, or immune function. Recent studies have also shown that a genome-wide pattern of local adaptation can be detected by identifying correlations between patterns of allele frequencies and environmental variables. Despite these observations, the degree to which natural selection is primarily driven by adaptation to local environments, and the role of pathogens or other ecological factors as selective agents, is still under debate. To address this issue, we correlated the spatial allele frequency distribution of a large sample of SNPs from 55 distinct human populations to a set of environmental factors that describe local geographical features such as climate, diet regimes, and pathogen loads. In concordance with previous studies, we detected a significant enrichment of genic SNPs, and particularly non-synonymous SNPs associated with local adaptation. Furthermore, we show that the diversity of the local pathogenic environment is the predominant driver of local adaptation, and that climate, at least as measured here, only plays a relatively minor role. While background demography by far makes the strongest contribution in explaining the genetic variance among populations, we detected about 100 genes which show an unexpectedly strong correlation between allele frequencies and pathogenic environment, after correcting for demography. Conversely, for diet regimes and climatic conditions, no genes show a similar correlation between the environmental factor and allele frequencies. This result is validated using low-coverage sequencing data for multiple populations. Among the loci targeted by pathogen-driven selection, we found an enrichment of genes associated to autoimmune diseases, such as celiac disease, type 1 diabetes, and multiples sclerosis, which lends credence to the

  5. Dengue virus genomic variation associated with mosquito adaptation defines the pattern of viral non-coding RNAs and fitness in human cells.

    Directory of Open Access Journals (Sweden)

    Claudia V Filomatori

    2017-03-01

    Full Text Available The Flavivirus genus includes a large number of medically relevant pathogens that cycle between humans and arthropods. This host alternation imposes a selective pressure on the viral population. Here, we found that dengue virus, the most important viral human pathogen transmitted by insects, evolved a mechanism to differentially regulate the production of viral non-coding RNAs in mosquitos and humans, with a significant impact on viral fitness in each host. Flavivirus infections accumulate non-coding RNAs derived from the viral 3'UTRs (known as sfRNAs, relevant in viral pathogenesis and immune evasion. We found that dengue virus host adaptation leads to the accumulation of different species of sfRNAs in vertebrate and invertebrate cells. This process does not depend on differences in the host machinery; but it was found to be dependent on the selection of specific mutations in the viral 3'UTR. Dissecting the viral population and studying phenotypes of cloned variants, the molecular determinants for the switch in the sfRNA pattern during host change were mapped to a single RNA structure. Point mutations selected in mosquito cells were sufficient to change the pattern of sfRNAs, induce higher type I interferon responses and reduce viral fitness in human cells, explaining the rapid clearance of certain viral variants after host change. In addition, using epidemic and pre-epidemic Zika viruses, similar patterns of sfRNAs were observed in mosquito and human infected cells, but they were different from those observed during dengue virus infections, indicating that distinct selective pressures act on the 3'UTR of these closely related viruses. In summary, we present a novel mechanism by which dengue virus evolved an RNA structure that is under strong selective pressure in the two hosts, as regulator of non-coding RNA accumulation and viral fitness. This work provides new ideas about the impact of host adaptation on the variability and evolution of

  6. Including pathogen risk in life cycle assessment of wastewater management. 1. Estimating the burden of disease associated with pathogens.

    Science.gov (United States)

    Harder, Robin; Heimersson, Sara; Svanström, Magdalena; Peters, Gregory M

    2014-08-19

    The environmental performance of wastewater and sewage sludge management is commonly assessed using life cycle assessment (LCA), whereas pathogen risk is evaluated with quantitative microbial risk assessment (QMRA). This study explored the application of QMRA methodology with intent to include pathogen risk in LCA and facilitate a comparison with other potential impacts on human health considered in LCA. Pathogen risk was estimated for a model wastewater treatment system (WWTS) located in an industrialized country and consisting of primary, secondary, and tertiary wastewater treatment, anaerobic sludge digestion, and land application of sewage sludge. The estimation was based on eight previous QMRA studies as well as parameter values taken from the literature. A total pathogen risk (expressed as burden of disease) on the order of 0.2-9 disability-adjusted life years (DALY) per year of operation was estimated for the model WWTS serving 28,600 persons and for the pathogens and exposure pathways included in this study. The comparison of pathogen risk with other potential impacts on human health considered in LCA is detailed in part 2 of this article series.

  7. Paleogene radiation of a plant pathogenic mushroom.

    Directory of Open Access Journals (Sweden)

    Martin P A Coetzee

    Full Text Available The global movement and speciation of fungal plant pathogens is important, especially because of the economic losses they cause and the ease with which they are able to spread across large areas. Understanding the biogeography and origin of these plant pathogens can provide insights regarding their dispersal and current day distribution. We tested the hypothesis of a Gondwanan origin of the plant pathogenic mushroom genus Armillaria and the currently accepted premise that vicariance accounts for the extant distribution of the species.The phylogeny of a selection of Armillaria species was reconstructed based on Maximum Parsimony (MP, Maximum Likelihood (ML and Bayesian Inference (BI. A timeline was then placed on the divergence of lineages using a Bayesian relaxed molecular clock approach.Phylogenetic analyses of sequenced data for three combined nuclear regions provided strong support for three major geographically defined clades: Holarctic, South American-Australasian and African. Molecular dating placed the initial radiation of the genus at 54 million years ago within the Early Paleogene, postdating the tectonic break-up of Gondwana.The distribution of extant Armillaria species is the result of ancient long-distance dispersal rather than vicariance due to continental drift. As these finding are contrary to most prior vicariance hypotheses for fungi, our results highlight the important role of long-distance dispersal in the radiation of fungal pathogens from the Southern Hemisphere.

  8. Pathogenicity and molecular detection of Uruguayan isolates of Greeneria uvicola and Cadophora luteo-olivacea associated with grapevine trunk diseases

    Directory of Open Access Journals (Sweden)

    Fernando NAVARRETE

    2011-12-01

    Full Text Available Normal 0 21 MicrosoftInternetExplorer4 Species from different fungal genera have been indicated as responsible for the development of trunk diseases of grapevines. Greeneria uvicola is responsible for the bitter rot of Vitis vinifera grape bunchesnear harvest, and can also attack other Vitis species. In Uruguay, G. uvicola was isolated from dead arm affected grapevines and as an endophyte from healthy canes. Cadophora luteo-olivacea is a phialophora-likeascomycete with a wide distribution that was isolated from asymptomatic wood tissues in Vitis and Petridisease-affected nursery plants in Uruguay. Pathogenicity of isolates of both species was evaluated on Vitis vinifera cv. Tannat and Cabernet Sauvignon, and rootstocks SO4 and 3309C. Specific primers were developed for the ITS rDNA region for both species. Number of plants showing discoloration, length of discoloration, number of re-isolations and amplifications confirmed the pathogenicity of G. uvicola isolates. Pathogenicityof the isolate of C. luteo-olivacea obtained from symptomatic tissues is discussed. Specific primers can be usedto detect the presence of these fungi in asymptomatic tissues.

  9. Phosphate-Containing Polyethylene Glycol Polymers Prevent Lethal Sepsis by Multidrug-Resistant Pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Zaborin, Alexander; Defazio, Jennifer; Kade, Matthew; Kaiser, Brooke LD; Belogortseva, Natalia; Camp, David G.; Smith, Richard D.; Adkins, Joshua N.; Kim, Sangman M.; Alverdy, Alexandria; Goldfeld, David; Firestone, Millicent; Collier, Joel; Jabri, Bana; Tirrell, Matthew; Zaborina, Olga; Alverdy, John C.

    2014-02-01

    The gastrointestinal tract is the primary site of colonization for multi-drug resistant healthcare associated pathogens (HAPs) that are the principal source and cause of life-threatening infections in critically ill patients. We previously identified a high molecular weight co-polymer (PEG15-20) with mucoadhesive and cytoprotective actions on the intestinal epithelium. In this report we covalently bonded phosphate (Pi) to PEG15-20 ( termed Pi-PEG15-20) to enhance its cytoprotective activity against microbial virulence activation and invasion based on our previous work showing that Pi is a key environmental cue regulating microbial virulence across pathogens of clinical importance to hospitalized patients. We demonstrated that Pi-PEG15-20 can suppress phosphate-, iron-, and quorum sensing signal- mediated activation of bacterial virulence as well as inhibit intestinal epithelial IL-8 release during lipopolysaccharide (LPS) exposure. Pi-PEG15-20 also prevented mortality in C. elegans and mice exposed to several highly virulent and antibiotic(?)-resistant health care acquired pathogens (HAPs) while preserving the normal microbiota. Intestinal application Pi-PEG 15-20 has the potential to be a useful agent to prevent the pathogenic activation of microbes during critical illness where exposure to HAPs is ubiquitous.

  10. Molecular features of colorectal polyps presenting Kudo’s type II mucosal crypt pattern: are they based on the same mechanism of tumorigenesis?

    Science.gov (United States)

    Shinmura, Kensuke; Konishi, Kazuo; Yamochi, Toshiko; Kubota, Yutaro; Yano, Yuichiro; Katagiri, Atsushi; Muramoto, Takashi; Kihara, Toshihiro; Tojo, Masayuki; Konda, Kenichi; Tagawa, Teppei; Yanagisawa, Fumito; Kogo, Mari; Makino, Reiko; Takimoto, Masafumi; Yoshida, Hitoshi

    2014-01-01

    Background and study aims: The molecular features of serrated polyps (SPs) with hyperplastic crypt pattern, also called Kudo’s type II observed by chromoendoscopy, were evaluated. Methods: The clinicopathological and molecular features of 114 SPs with a hyperplastic pit pattern detected under chromoendoscopy (five dysplastic SPs, 63 sessile serrated adenoma/polyps (SSA/Ps), 36 microvesicular hyperplastic polyps (MVHPs), and 10 goblet cell-rich hyperplastic polyps (GCHPs)) were examined. The frequency of KRAS and BRAF mutations and CpG island methylator phenotype (CIMP) were investigated. Results: Dysplastic SPs and SSA/Ps were frequently located in the proximal colon compared to others (SSA/Ps vs. MVHPs or GCHPs, P GCHP (60 % for dysplastic SPs, 44 % for SSA/Ps, 47 % for MVHPs, and 0 % for GCHPs). The frequency of CIMP was higher in dysplastic SPs or SSA/Ps than in MVHPs or GCHPs (60 % for dysplastic SPs, 56 % for SSA/Ps, 32 % for MVHPs, and 10 % for GCHPs) (SSA/Ps vs. GCHP, P = 0.0068). When serrated neoplasias (SNs) and MVHPs were classified into proximal and distal lesions, the frequency of CIMP was significantly higher in the proximal compared to the distal SNs (64 % vs. 11 %, P = 0.0032). Finally, multivariate analysis showed that proximal location and BRAF mutation were significantly associated with an increased risk of CIMP. Conclusions: Distinct molecular features were observed between proximal and distal SPs with hyperplastic crypt pattern. Proximal MVHPs may develop more frequently through SSA/Ps to CIMP cancers than distal MVHPs. PMID:26134964

  11. [Etiological and molecular characteristics of diarrhea caused Proteus mirabilis].

    Science.gov (United States)

    Shi, Xiaolu; Hu, Qinghua; Lin, Yiman; Qiu, Yaqun; Li, Yinghui; Jiang, Min; Chen, Qiongcheng

    2014-06-01

    To analyze the etiological characteristics, virulence genes and plasmids that carrying diarrhea-causing Proteus mirabilis and to assess their relationship with drug resistance and pathogenicity. Proteus mirabilis coming from six different sources (food poisoning, external environment and healthy people) were analyzed biochemically, on related susceptibility and pulsed-field gel electrophoresis (PFGE). Virulence genes were detected by PCR. Plasmids were extracted and sequenced after gel electrophoresis purification. The biochemical characteristics of Proteus mirabilis from different sources seemed basically the same, and each of them showed having common virulence genes, as ureC, rsmA, hpmA and zapA. However, the PFGE patterns and susceptibility of these strains were different, so as the plasmids that they carried. Plasmid that presented in the sequenced strain showed that the 2 683 bp length plasmid encodes qnrD gene was associated with the quinolone resistance. Etiological characteristics and molecular characteristics of Proteus mirabilis gathered from different sources, were analyzed. Results indicated that traditional biochemical analysis and common virulence gene identification might be able to distinguish the strains with different sources. However, PFGE and plasmids analysis could distinguish the sources of strains and to identify those plasmids that commonly carried by the drug-resistant strains. These findings also provided theoretical basis for further study on the nature of resistance and pathogenicity in Proteus mirabilis.

  12. Distribution and prevalence of crown rot pathogens affecting wheat crops in southern Chile

    Directory of Open Access Journals (Sweden)

    Ernesto Moya-Elizondo

    2015-03-01

    Full Text Available Crown rot pathogens are associated with higher losses for wheat crop farmers, but information about the distribution and prevalence of these pathogens in Chile is inadequate. Distribution and prevalence of wheat (Triticum aestivum L. crown rot pathogens were examined in a survey of 48 commercial fields from December 2011 to February 2012 in southern Chile. These fields were located between Collipulli (37°56'00" S; 72°26'39" W and Purranque (40°50'30" S; 73°22'03" W. Severity of crown rot disease was determined through visual assessment of the first internode of 20 tillers obtained from each field. Incidence of crown rot pathogens per field was determined by plating the 20 tillers on Petri plates with 20% potato dextrose agar amended with lactic acid (aPDA medium. Resulting fungal colonies from monoxenic culture were identified by morphological or molecular-assisted identification. Severity of crown rot varied between 11.3% and 80% for individual fields. Culture plate analysis showed 72.2% of stems were infected with some fungus. Fusarium avenaceum, F. graminearum, and F. culmorum, pathogens associated with Fusarium crown rot disease were isolated from 13.5% of tillers. Gaeumannomyces graminis, causal agent of take-all disease in cereals, was isolated from 11.1% of culms. Phaeosphaeria sp., an endophyte and possibly a non-pathogenic fungus, was isolated from 13.9% of tillers. Pathogenic fungi such as Rhizoctonia spp. and Microdochium nivale, other saprophyte, and several unidentified non-sporulating fungi were isolated at frequencies lower than 3% of the total. Fusarium crown rot and take-all were the most prevalent and distributed crown rot diseases present in wheat crops in southern Chile.

  13. Genome Assembly and Computational Analysis Pipelines for Bacterial Pathogens

    KAUST Repository

    Rangkuti, Farania Gama Ardhina

    2011-06-01

    Pathogens lie behind the deadliest pandemics in history. To date, AIDS pandemic has resulted in more than 25 million fatal cases, while tuberculosis and malaria annually claim more than 2 million lives. Comparative genomic analyses are needed to gain insights into the molecular mechanisms of pathogens, but the abundance of biological data dictates that such studies cannot be performed without the assistance of computational approaches. This explains the significant need for computational pipelines for genome assembly and analyses. The aim of this research is to develop such pipelines. This work utilizes various bioinformatics approaches to analyze the high-­throughput genomic sequence data that has been obtained from several strains of bacterial pathogens. A pipeline has been compiled for quality control for sequencing and assembly, and several protocols have been developed to detect contaminations. Visualization has been generated of genomic data in various formats, in addition to alignment, homology detection and sequence variant detection. We have also implemented a metaheuristic algorithm that significantly improves bacterial genome assemblies compared to other known methods. Experiments on Mycobacterium tuberculosis H37Rv data showed that our method resulted in improvement of N50 value of up to 9697% while consistently maintaining high accuracy, covering around 98% of the published reference genome. Other improvement efforts were also implemented, consisting of iterative local assemblies and iterative correction of contiguated bases. Our result expedites the genomic analysis of virulent genes up to single base pair resolution. It is also applicable to virtually every pathogenic microorganism, propelling further research in the control of and protection from pathogen-­associated diseases.

  14. Heat Shock Proteins: A Review of the Molecular Chaperones for Plant Immunity.

    Science.gov (United States)

    Park, Chang-Jin; Seo, Young-Su

    2015-12-01

    As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock proteins (HSPs) functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs) or resistance (R) proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER) HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

  15. Heat Shock Proteins: A Review of the Molecular Chaperones for Plant Immunity

    Directory of Open Access Journals (Sweden)

    Chang-Jin Park

    2015-12-01

    Full Text Available As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock proteins (HSPs functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs or resistance (R proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

  16. Network Analysis Highlights Complex Interactions between Pathogen, Host and Commensal Microbiota

    Science.gov (United States)

    Boutin, Sébastien; Bernatchez, Louis; Audet, Céline; Derôme, Nicolas

    2013-01-01

    Interactions between bacteria and their host represent a full continuum from pathogenicity to mutualism. From an evolutionary perspective, host-bacteria relationships are no longer considered a two-component system but rather a complex network. In this study, we focused on the relationship between brook charr (Salvelinus fontinalis) and bacterial communities developing on skin mucus. We hypothesized that stressful conditions such as those occurring in aquaculture production induce shifts in the bacterial community of healthy fish, thus allowing pathogens to cause infections. The results showed that fish skin mucus microbiota taxonomical structure is highly specific, its diversity being partly influenced by the surrounding water bacterial community. Two types of taxonomic co-variation patterns emerged across 121 contrasted communities’ samples: one encompassing four genera well known for their probiotic properties, the other harboring five genera mostly associated with pathogen species. The homeostasis of fish bacterial community was extensively disturbed by induction of physiological stress in that both: 1) the abundance of probiotic-like bacteria decreased after stress exposure; and 2) pathogenic bacteria increased following stress exposure. This study provides further insights regarding the role of mutualistic bacteria as a primary host protection barrier. PMID:24376845

  17. Network analysis highlights complex interactions between pathogen, host and commensal microbiota.

    Directory of Open Access Journals (Sweden)

    Sébastien Boutin

    Full Text Available Interactions between bacteria and their host represent a full continuum from pathogenicity to mutualism. From an evolutionary perspective, host-bacteria relationships are no longer considered a two-component system but rather a complex network. In this study, we focused on the relationship between brook charr (Salvelinus fontinalis and bacterial communities developing on skin mucus. We hypothesized that stressful conditions such as those occurring in aquaculture production induce shifts in the bacterial community of healthy fish, thus allowing pathogens to cause infections. The results showed that fish skin mucus microbiota taxonomical structure is highly specific, its diversity being partly influenced by the surrounding water bacterial community. Two types of taxonomic co-variation patterns emerged across 121 contrasted communities' samples: one encompassing four genera well known for their probiotic properties, the other harboring five genera mostly associated with pathogen species. The homeostasis of fish bacterial community was extensively disturbed by induction of physiological stress in that both: 1 the abundance of probiotic-like bacteria decreased after stress exposure; and 2 pathogenic bacteria increased following stress exposure. This study provides further insights regarding the role of mutualistic bacteria as a primary host protection barrier.

  18. Device-associated infections among neonatal intensive care unit patients: incidence and associated pathogens reported to the National Healthcare Safety Network, 2006-2008.

    Science.gov (United States)

    Hocevar, Susan N; Edwards, Jonathan R; Horan, Teresa C; Morrell, Gloria C; Iwamoto, Martha; Lessa, Fernanda C

    2012-12-01

    To describe rates and pathogen distribution of device-associated infections (DAIs) in neonatal intensive care unit (NICU) patients and compare differences in infection rates by hospital type (children's vs general hospitals). Neonates in NICUs participating in the National Healthcare Safety Network from 2006 through 2008. We analyzed central line-associated bloodstream infections (CLABSIs), umbilical catheter-associated bloodstream infections (UCABs), and ventilator-associated pneumonia (VAP) among 304 NICUs. Differences in pooled mean incidence rates were examined using Poisson regression; nonparametric tests for comparing medians and rate distributions were used. Pooled mean incidence rates by birth weight category (750 g or less, 751-1,000 g, 1,001-1,500 g, 1,501-2,500 g, and more than 2,500 g, respectively) were 3.94, 3.09, 2.25, 1.90, and 1.60 for CLABSI; 4.52, 2.77, 1.70, 0.91, and 0.92 for UCAB; and 2.36, 2.08, 1.28, 0.86, and 0.72 for VAP. When rates of infection between hospital types were compared, only pooled mean VAP rates were significantly lower in children's hospitals than in general hospitals among neonates weighing 1,000 g or less; no significant differences in medians or rate distributions were noted. Pathogen frequencies were coagulase-negative staphylococci (28%), Staphylococcus aureus (19%), and Candida species (13%) for bloodstream infections and Pseudomonas species (16%), S. aureus (15%), and Klebsiella species (14%) for VAP. Of 673 S. aureus isolates with susceptibility results, 33% were methicillin resistant. Neonates weighing 750 g or less had the highest DAI incidence. With the exception of VAP, pooled mean NICU incidence rates did not differ between children's and general hospitals. Pathogens associated with these infections can pose treatment challenges; continued efforts at prevention need to be applied to all NICU settings.

  19. Autoimmunity due to molecular mimicry as a cause of neurological disease.

    Science.gov (United States)

    Levin, Michael C; Lee, Sang Min; Kalume, Franck; Morcos, Yvette; Dohan, F Curtis; Hasty, Karen A; Callaway, Joseph C; Zunt, Joseph; Desiderio, Dominic; Stuart, John M

    2002-05-01

    One hypothesis that couples infection with autoimmune disease is molecular mimicry. Molecular mimicry is characterized by an immune response to an environmental agent that cross-reacts with a host antigen, resulting in disease. This hypothesis has been implicated in the pathogenesis of diabetes, lupus and multiple sclerosis (MS). There is limited direct evidence linking causative agents with pathogenic immune reactions in these diseases. Our study establishes a clear link between viral infection, autoimmunity and neurological disease in humans. As a model for molecular mimicry, we studied patients with human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a disease that can be indistinguishable from MS (refs. 5,6,7). HAM/TSP patients develop antibodies to neurons. We hypothesized these antibodies would identify a central nervous system (CNS) autoantigen. Immunoglobulin G isolated from HAM/TSP patients identified heterogeneous nuclear ribonuclear protein-A1 (hnRNP-A1) as the autoantigen. Antibodies to hnRNP-A1 cross-reacted with HTLV-1-tax, the immune response to which is associated with HAM/TSP (refs. 5,9). Immunoglobulin G specifically stained human Betz cells, whose axons are preferentially damaged. Infusion of autoantibodies in brain sections inhibited neuronal firing, indicative of their pathogenic nature. These data demonstrate the importance of molecular mimicry between an infecting agent and hnRNP-A1 in autoimmune disease of the CNS.

  20. Models of Caenorhabditis elegans infection by bacterial and fungal pathogens.

    Science.gov (United States)

    Powell, Jennifer R; Ausubel, Frederick M

    2008-01-01

    The nematode Caenorhabditis elegans is a simple model host for studying the relationship between the animal innate immune system and a variety of bacterial and fungal pathogens. Extensive genetic and molecular tools are available in C. elegans, facilitating an in-depth analysis of host defense factors and pathogen virulence factors. Many of these factors are conserved in insects and mammals, indicating the relevance of the nematode model to the vertebrate innate immune response. Here, we describe pathogen assays for a selection of the most commonly studied bacterial and fungal pathogens using the C. elegans model system.

  1. Acinetobacter spp. as nosocomial pathogens: Epidemiology and resistance features

    Directory of Open Access Journals (Sweden)

    Saad B. Almasaudi

    2018-03-01

    Full Text Available The genus Acinetobacter is a major cause of nosocomial infections; it is increasingly being associated with various epidemics and has become a widespread concern in a variety of hospitals worldwide. Multi-antibiotic resistant Acinetobacter baumannii, is now recognized to be of great clinical significance. Numerous reports relay to the spread of A. baumannii in the hospital settings which leads to enhanced nosocomial outbreaks associated with high death rates. However, many other Acinetobacter spp. also can cause nosocomial infections. This review focused on the role of Acinetobacter spp. as nosocomial pathogens in addition to their persistence, antimicrobial resistance patterns and epidemiology. Keywords: Acinetobacter, Nosocomial infections, Multi-drug resistance, Epidemiology, Characteristics

  2. Pathogenic Link Between Postextubation Pneumonia and Ventilator-Associated Pneumonia: An Experimental Study.

    Science.gov (United States)

    Rezoagli, Emanuele; Zanella, Alberto; Cressoni, Massimo; De Marchi, Lorenzo; Kolobow, Theodor; Berra, Lorenzo

    2017-04-01

    The presence of an endotracheal tube is the main cause for developing ventilator-associated pneumonia (VAP), but pneumonia can still develop in hospitalized patients after endotracheal tube removal (postextubation pneumonia [PEP]). We hypothesized that short-term intubation (24 hours) can play a role in the pathogenesis of PEP. To test such hypothesis, we initially evaluated the occurrence of lung colonization and VAP in sheep that were intubated and mechanically ventilated for 24 hours. Subsequently, we assessed the incidence of lung colonization and PEP at 48 hours after extubation in sheep previously ventilated for 24 hours. To simulate intubated intensive care unit patients placed in semirecumbent position, 14 sheep were intubated and mechanically ventilated with the head elevated 30° above horizontal. Seven of them were euthanized after 24 hours (Control Group), whereas the remaining were euthanized after being awaken, extubated, and left spontaneously breathing for 48 hours after extubation (Awake Group). Criteria of clinical diagnosis of pneumonia were tested. Microbiological evaluation was performed on autopsy in all sheep. Only 1 sheep in the Control Group met the criteria of VAP after 24 hours of mechanical ventilation. However, heavy pathogenic bacteria colonization of trachea, bronchi, and lungs (range, 10-10 colony-forming unit [CFU]/g) was reported in 4 of 7 sheep (57%). In the Awake Group, 1 sheep was diagnosed with VAP and 3 developed PEP within 48 hours after extubation (42%), with 1 euthanized at 30 hours because of respiratory failure. On autopsy, 5 sheep (71%) confirmed pathogenic bacterial growth in the lower respiratory tract (range, 10-10 CFU/g). Twenty-four hours of intubation and mechanical ventilation in semirecumbent position leads to significant pathogenic colonization of the lower airways, which can promote the development of PEP. Strategies directed to prevent pathogenic microbiological colonization before and after mechanical

  3. The quantitative basis of the Arabidopsis innate immune system to endemic pathogens depends on pathogen genetics

    DEFF Research Database (Denmark)

    Corwin, Jason A; Copeland, Daniel; Feusier, Julie

    2016-01-01

    The most established model of the eukaryotic innate immune system is derived from examples of large effect monogenic quantitative resistance to pathogens. However, many host-pathogen interactions involve many genes of small to medium effect and exhibit quantitative resistance. We used the Arabido......The most established model of the eukaryotic innate immune system is derived from examples of large effect monogenic quantitative resistance to pathogens. However, many host-pathogen interactions involve many genes of small to medium effect and exhibit quantitative resistance. We used....... cinerea, we identified a total of 2,982 genes associated with quantitative resistance using lesion area and 3,354 genes associated with camalexin production as measures of the interaction. Most genes were associated with resistance to a specific Botrytis isolate, which demonstrates the influence...... genes associated with quantitative resistance. Using publically available co-expression data, we condensed the quantitative resistance associated genes into co-expressed gene networks. GO analysis of these networks implicated several biological processes commonly connected to disease resistance...

  4. Species-specific chitin-binding module 18 expansion in the amphibian pathogen Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Abramyan, John; Stajich, Jason E

    2012-01-01

    spread and associated decline in amphibian populations, it is imperative to incorporate novel genomic and genetic techniques into the study of this species. In this study, we present the first reported potential pathogenicity factors in B. dendrobatidis. In silico studies such as this allow us to identify putative targets for more specific molecular analyses, furthering our hope for the control of this pathogen.

  5. Comparison of pathogen DNA isolation methods from large volumes of whole blood to improve molecular diagnosis of bloodstream infections.

    Directory of Open Access Journals (Sweden)

    Anne J M Loonen

    Full Text Available For patients suffering from bloodstream infections (BSI molecular diagnostics from whole blood holds promise to provide fast and adequate treatment. However, this approach is hampered by the need of large blood volumes. Three methods for pathogen DNA isolation from whole blood were compared, i.e. an enzymatic method (MolYsis, 1-5 ml, the novel non-enzymatic procedure (Polaris, 1-5 ml, and a method that does not entail removal of human DNA (Triton-Tris-EDTA EasyMAG, 200 µl. These methods were evaluated by processing blood spiked with 0-1000 CFU/ml of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Downstream detection was performed with real-time PCR assays. Polaris and MolYsis processing followed by real-time PCRs enabled pathogen detection at clinically relevant concentrations of 1-10 CFU/ml blood. By increasing sample volumes, concurrent lower cycle threshold (Ct values were obtained at clinically relevant pathogen concentrations, demonstrating the benefit of using larger blood volumes. A 100% detection rate at a concentration of 10 CFU/ml for all tested pathogens was obtained with the Polaris enrichment, whereas comparatively lower detection rates were measured for MolYsis (50-67% and EasyMAG (58-79%. For the samples with a concentration of 1 CFU/ml Polaris resulted in most optimal detection rates of 70-75% (MolYsis 17-50% and TTE-EasyMAG 20-36%. The Polaris method was more reproducible, less labour intensive, and faster (45 minutes (including Qiagen DNA extraction vs. 2 hours (MolYsis. In conclusion, Polaris and MolYsis enrichment followed by DNA isolation and real-time PCR enables reliable and sensitive detection of bacteria and fungi from 5 ml blood. With Polaris results are available within 3 hours, showing potential for improved BSI diagnostics.

  6. Opportunities and challenges associated with clinical diagnostic genome sequencing: a report of the Association for Molecular Pathology.

    Science.gov (United States)

    Schrijver, Iris; Aziz, Nazneen; Farkas, Daniel H; Furtado, Manohar; Gonzalez, Andrea Ferreira; Greiner, Timothy C; Grody, Wayne W; Hambuch, Tina; Kalman, Lisa; Kant, Jeffrey A; Klein, Roger D; Leonard, Debra G B; Lubin, Ira M; Mao, Rong; Nagan, Narasimhan; Pratt, Victoria M; Sobel, Mark E; Voelkerding, Karl V; Gibson, Jane S

    2012-11-01

    This report of the Whole Genome Analysis group of the Association for Molecular Pathology illuminates the opportunities and challenges associated with clinical diagnostic genome sequencing. With the reality of clinical application of next-generation sequencing, technical aspects of molecular testing can be accomplished at greater speed and with higher volume, while much information is obtained. Although this testing is a next logical step for molecular pathology laboratories, the potential impact on the diagnostic process and clinical correlations is extraordinary and clinical interpretation will be challenging. We review the rapidly evolving technologies; provide application examples; discuss aspects of clinical utility, ethics, and consent; and address the analytic, postanalytic, and professional implications. Copyright © 2012 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  7. Herpes Simplex Virus Type 1 and Other Pathogens are Key Causative Factors in Sporadic Alzheimer’s Disease

    Science.gov (United States)

    Harris, Steven A.; Harris, Elizabeth A.

    2015-01-01

    Abstract This review focuses on research in epidemiology, neuropathology, molecular biology, and genetics regarding the hypothesis that pathogens interact with susceptibility genes and are causative in sporadic Alzheimer’s disease (AD). Sporadic AD is a complex multifactorial neurodegenerative disease with evidence indicating coexisting multi-pathogen and inflammatory etiologies. There are significant associations between AD and various pathogens, including Herpes simplex virus type 1 (HSV-1), Cytomegalovirus, and other Herpesviridae, Chlamydophila pneumoniae, spirochetes, Helicobacter pylori, and various periodontal pathogens. These pathogens are able to evade destruction by the host immune system, leading to persistent infection. Bacterial and viral DNA and RNA and bacterial ligands increase the expression of pro-inflammatory molecules and activate the innate and adaptive immune systems. Evidence demonstrates that pathogens directly and indirectly induce AD pathology, including amyloid-β (Aβ) accumulation, phosphorylation of tau protein, neuronal injury, and apoptosis. Chronic brain infection with HSV-1, Chlamydophila pneumoniae, and spirochetes results in complex processes that interact to cause a vicious cycle of uncontrolled neuroinflammation and neurodegeneration. Infections such as Cytomegalovirus, Helicobacter pylori, and periodontal pathogens induce production of systemic pro-inflammatory cytokines that may cross the blood-brain barrier to promote neurodegeneration. Pathogen-induced inflammation and central nervous system accumulation of Aβ damages the blood-brain barrier, which contributes to the pathophysiology of AD. Apolipoprotein E4 (ApoE4) enhances brain infiltration by pathogens including HSV-1 and Chlamydophila pneumoniae. ApoE4 is also associated with an increased pro-inflammatory response by the immune system. Potential antimicrobial treatments for AD are discussed, including the rationale for antiviral and antibiotic clinical trials. PMID

  8. Transcriptome sequencing of Mycosphaerella fijiensis during association with Musa acuminata reveals candidate pathogenicity genes.

    Science.gov (United States)

    Noar, Roslyn D; Daub, Margaret E

    2016-08-30

    genes with higher expression in infected leaf tissue, suggesting that they may play a role in pathogenicity. For two other scaffolds, no transcripts were detected in either condition, and PCR assays support the hypothesis that at least one of these scaffolds corresponds to a dispensable chromosome that is not required for survival or pathogenicity. Our study revealed major changes in the transcriptome of Mycosphaerella fijiensis, when associating with its host compared to during saprophytic growth in medium. This analysis identified putative pathogenicity genes and also provides support for the existence of dispensable chromosomes in this fungus.

  9. Regulatory Proteolysis in Arabidopsis-Pathogen Interactions.

    Science.gov (United States)

    Pogány, Miklós; Dankó, Tamás; Kámán-Tóth, Evelin; Schwarczinger, Ildikó; Bozsó, Zoltán

    2015-09-24

    Approximately two and a half percent of protein coding genes in Arabidopsis encode enzymes with known or putative proteolytic activity. Proteases possess not only common housekeeping functions by recycling nonfunctional proteins. By irreversibly cleaving other proteins, they regulate crucial developmental processes and control responses to environmental changes. Regulatory proteolysis is also indispensable in interactions between plants and their microbial pathogens. Proteolytic cleavage is simultaneously used both by plant cells, to recognize and inactivate invading pathogens, and by microbes, to overcome the immune system of the plant and successfully colonize host cells. In this review, we present available results on the group of proteases in the model plant Arabidopsis thaliana whose functions in microbial pathogenesis were confirmed. Pathogen-derived proteolytic factors are also discussed when they are involved in the cleavage of host metabolites. Considering the wealth of review papers available in the field of the ubiquitin-26S proteasome system results on the ubiquitin cascade are not presented. Arabidopsis and its pathogens are conferred with abundant sets of proteases. This review compiles a list of those that are apparently involved in an interaction between the plant and its pathogens, also presenting their molecular partners when available.

  10. Children with asthma by school age display aberrant immune responses to pathogenic airway bacteria as infants

    DEFF Research Database (Denmark)

    Larsen, Jeppe Madura; Pedersen, Susanne Brix; Thysen, Anna Hammerich

    2014-01-01

    childhood asthma. We hypothesized that children with asthma have an abnormal immune response to pathogenic bacteria in infancy. ObjectiveWe aimed to assess the bacterial immune response in asymptomatic infants and the association with later development of asthma by age 7 years. MethodsThe Copenhagen...... was assessed based on the pattern of cytokines produced and T-cell activation. ResultsThe immune response to pathogenic bacteria was different in infants with asthma by 7 years of age (P = .0007). In particular, prospective asthmatic subjects had aberrant production of IL-5 (P = .008), IL-13 (P = .057), IL-17...... (P = .001), and IL-10 (P = .028), whereas there were no differences in T-cell activation or peripheral T-cell composition. ConclusionsChildren with asthma by school age exhibited an aberrant immune response to pathogenic bacteria in infancy. We propose that an abnormal immune response to pathogenic...

  11. Molecular genetic analysis of the pathogenicity of the potato cyst nematode Globodera rostochiensis

    NARCIS (Netherlands)

    Qin, L.

    2001-01-01

    A new strategy to identify pathogenicity factors from the potato cyst nematode Globodera rostochiensis is developed. cDNA-AFLP technology and in situ hybridization allowed us to efficiently select putative pathogenicity factors among thousands of

  12. European surveillance of emerging pathogens associated with canine infectious respiratory disease.

    Science.gov (United States)

    Mitchell, Judy A; Cardwell, Jacqueline M; Leach, Heather; Walker, Caray A; Le Poder, Sophie; Decaro, Nicola; Rusvai, Miklos; Egberink, Herman; Rottier, Peter; Fernandez, Mireia; Fragkiadaki, Eirini; Shields, Shelly; Brownlie, Joe

    2017-12-01

    Canine infectious respiratory disease (CIRD) is a major cause of morbidity in dogs worldwide, and is associated with a number of new and emerging pathogens. In a large multi-centre European study the prevalences of four key emerging CIRD pathogens; canine respiratory coronavirus (CRCoV), canine pneumovirus (CnPnV), influenza A, and Mycoplasma cynos (M. cynos); were estimated, and risk factors for exposure, infection and clinical disease were investigated. CIRD affected 66% (381/572) of the dogs studied, including both pet and kennelled dogs. Disease occurrence and severity were significantly reduced in dogs vaccinated against classic CIRD agents, canine distemper virus (CDV), canine adenovirus 2 (CAV-2) and canine parainfluenza virus (CPIV), but substantial proportions (65.7%; 201/306) of vaccinated dogs remained affected. CRCoV and CnPnV were highly prevalent across the different dog populations, with overall seropositivity and detection rates of 47% and 7.7% for CRCoV, and 41.7% and 23.4% for CnPnV, respectively, and their presence was associated with increased occurrence and severity of clinical disease. Antibodies to CRCoV had a protective effect against CRCoV infection and more severe clinical signs of CIRD but antibodies to CnPnV did not. Involvement of M. cynos and influenza A in CIRD was less apparent. Despite 45% of dogs being seropositive for M. cynos, only 0.9% were PCR positive for M. cynos. Only 2.7% of dogs were seropositive for Influenza A, and none were positive by PCR. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Parasites and Pathogens of the Honeybee (Apis mellifera and Their Influence on Inter-Colonial Transmission.

    Directory of Open Access Journals (Sweden)

    Nadège Forfert

    Full Text Available Pathogens and parasites may facilitate their transmission by manipulating host behavior. Honeybee pathogens and pests need to be transferred from one colony to another if they are to maintain themselves in a host population. Inter-colony transmission occurs typically through honeybee workers not returning to their home colony but entering a foreign colony ("drifting". Pathogens might enhance drifting to enhance transmission to new colonies. We here report on the effects infection by ten honeybee viruses and Nosema spp., and Varroa mite infestation on honeybee drifting. Genotyping of workers collected from colonies allowed us to identify genuine drifted workers as well as source colonies sending out drifters in addition to sink colonies accepting them. We then used network analysis to determine patterns of drifting. Distance between colonies in the apiary was the major factor explaining 79% of drifting. None of the tested viruses or Nosema spp. were associated with the frequency of drifting. Only colony infestation with Varroa was associated with significantly enhanced drifting. More specifically, colonies with high Varroa infestation had a significantly enhanced acceptance of drifters, although they did not send out more drifting workers. Since Varroa-infested colonies show an enhanced attraction of drifting workers, and not only those infected with Varroa and its associated pathogens, infestation by Varroa may also facilitate the uptake of other pests and parasites.

  14. An improved method of DNA extraction from plants for pathogen ...

    African Journals Online (AJOL)

    Polymerase chain reaction (PCR)-based applications in plant molecular biology and molecular diagnostics for plant pathogens require good quality DNA for reliable and reproducible results. Leaf tissue is often the choice for DNA extraction, but the use of other sources such as tubers, stems, or seeds, is not uncommon.

  15. Epigenetics of host-pathogen interactions: the road ahead and the road behind.

    Directory of Open Access Journals (Sweden)

    Elena Gómez-Díaz

    Full Text Available A growing body of evidence points towards epigenetic mechanisms being responsible for a wide range of biological phenomena, from the plasticity of plant growth and development to the nutritional control of caste determination in honeybees and the etiology of human disease (e.g., cancer. With the (partial elucidation of the molecular basis of epigenetic variation and the heritability of certain of these changes, the field of evolutionary epigenetics is flourishing. Despite this, the role of epigenetics in shaping host-pathogen interactions has received comparatively little attention. Yet there is plenty of evidence supporting the implication of epigenetic mechanisms in the modulation of the biological interaction between hosts and pathogens. The phenotypic plasticity of many key parasite life-history traits appears to be under epigenetic control. Moreover, pathogen-induced effects in host phenotype may have transgenerational consequences, and the bases of these changes and their heritability probably have an epigenetic component. The significance of epigenetic modifications may, however, go beyond providing a mechanistic basis for host and pathogen plasticity. Epigenetic epidemiology has recently emerged as a promising area for future research on infectious diseases. In addition, the incorporation of epigenetic inheritance and epigenetic plasticity mechanisms to evolutionary models and empirical studies of host-pathogen interactions will provide new insights into the evolution and coevolution of these associations. Here, we review the evidence available for the role epigenetics on host-pathogen interactions, and the utility and versatility of the epigenetic technologies available that can be cross-applied to host-pathogen studies. We conclude with recommendations and directions for future research on the burgeoning field of epigenetics as applied to host-pathogen interactions.

  16. Characterization and pathogenicity of Fusarium species associated with leaf spot of mango (Mangifera indica L.).

    Science.gov (United States)

    Omar, Nurul Husna; Mohd, Masratulhawa; Mohamed Nor, Nik Mohd Izham; Zakaria, Latiffah

    2018-01-01

    Leaf spot diseases are mainly caused by fungi including Fusarium. In the present study several species of Fusarium were isolated from the leaf spot lesion of mango (Mangifera indica L.) Based on morphological characteristics, TEF-1α sequences and phylogenetic analysis, five species were identified as F. proliferatum, F. semitectum, F. mangiferae, F. solani and F. chlamydosporum. Pathogenicity test indicated that representative isolates of F. proliferatum, F. semitectum and F. chlamydosporum were pathogenic on mango leaves causing leaf spot with low to moderate virulence. Nevertheless, abundance of spots on the leaf can disrupt photosynthesis which in turn reduced growth, and lead to susceptibility to infection by opportunistic pathogens due to weakening of the plant. Fusarium solani and F. mangiferae were non-pathogenic and it is possible that both species are saprophyte which associated with nutrient availability on the surface of the leaf through decaying leave tissues. The occurrence of Fusarium spp. on the leaf spot lesion and the effect from the disease needs to be considered when developing disease management method of mango cultivation as numerous spot on the leaves could effect the photosynthesis process and finally giving low yield and less quality of mango. Copyright © 2017. Published by Elsevier Ltd.

  17. Identification of food intake patterns and associated factors in teenagers

    Directory of Open Access Journals (Sweden)

    Jean Márcia Oliveira Mascarenhas

    2014-01-01

    Full Text Available OBJECTIVE: To identify schoolchildren"s dietary patterns and investigate the demographic, social, and economic determinants of the differences found between patterns. METHODS: The sample consisted of 1,330 students aged 11 to 17 years attending the public schools of Salvador, Bahia, Brazil. The subjects' food intake data were collected by a semiquantitative Food Frequency Questionnaire comprising 97 food items. All information was collected during a single interview. The exposure variables were gender, age, and socioeconomic class, and the outcome variables were categorized food consumption pattern in "mixed pattern", "traditional pattern", and "healthy pattern". The data were treated by simple and multiple linear regression analyses and the dietary patterns determined by factor analysis. RESULTS: Most participants were female (56.9% and over 13 years old (79.2%. The "mixed pattern" was positively associated with females (β=0.181, p0.0001 and classes D, C, and B (β=-0.125, p<0.023. CONCLUSION: Three dietary patterns were identified among the adolescents, namely mixed, traditional, and healthy. Gender and socioeconomic class were associated with dietary patterns. Male teenagers and those in the lower socioeconomic classes had a healthier dietary pattern than their peers of higher socioeconomic classes and females.

  18. Rats, cities, people, and pathogens: a systematic review and narrative synthesis of literature regarding the ecology of rat-associated zoonoses in urban centers.

    Science.gov (United States)

    Himsworth, Chelsea G; Parsons, Kirbee L; Jardine, Claire; Patrick, David M

    2013-06-01

    Urban Norway and black rats (Rattus norvegicus and Rattus rattus) are the source of a number of pathogens responsible for significant human morbidity and mortality in cities around the world. These pathogens include zoonotic bacteria (Leptospira interrogans, Yersina pestis, Rickettsia typhi, Bartonella spp., Streptobacillus moniliformis), viruses (Seoul hantavirus), and parasites (Angiostrongylus cantonensis). A more complete understanding of the ecology of these pathogens in people and rats is critical for determining the public health risks associated with urban rats and for developing strategies to monitor and mitigate those risks. Although the ecology of rat-associated zoonoses is complex, due to the multiple ways in which rats, people, pathogens, vectors, and the environment may interact, common determinants of human disease can still be identified. This review summarizes the ecology of zoonoses associated with urban rats with a view to identifying similarities, critical differences, and avenues for further study.

  19. The trans-kingdom identification of negative regulators of pathogen hypervirulence.

    Science.gov (United States)

    Brown, Neil A; Urban, Martin; Hammond-Kosack, Kim E

    2016-01-01

    Modern society and global ecosystems are increasingly under threat from pathogens, which cause a plethora of human, animal, invertebrate and plant diseases. Of increasing concern is the trans-kingdom tendency for increased pathogen virulence that is beginning to emerge in natural, clinical and agricultural settings. The study of pathogenicity has revealed multiple examples of convergently evolved virulence mechanisms. Originally described as rare, but increasingly common, are interactions where a single gene deletion in a pathogenic species causes hypervirulence. This review utilised the pathogen-host interaction database (www.PHI-base.org) to identify 112 hypervirulent mutations from 37 pathogen species, and subsequently interrogates the trans-kingdom, conserved, molecular, biochemical and cellular themes that cause hypervirulence. This study investigates 22 animal and 15 plant pathogens including 17 bacterial and 17 fungal species. Finally, the evolutionary significance and trans-kingdom requirement for negative regulators of hypervirulence and the implication of pathogen hypervirulence and emerging infectious diseases on society are discussed. © FEMS 2015.

  20. Whole genome sequencing revealed host adaptation-focused genomic plasticity of pathogenic Leptospira

    Science.gov (United States)

    Xu, Yinghua; Zhu, Yongzhang; Wang, Yuezhu; Chang, Yung-Fu; Zhang, Ying; Jiang, Xiugao; Zhuang, Xuran; Zhu, Yongqiang; Zhang, Jinlong; Zeng, Lingbing; Yang, Minjun; Li, Shijun; Wang, Shengyue; Ye, Qiang; Xin, Xiaofang; Zhao, Guoping; Zheng, Huajun; Guo, Xiaokui; Wang, Junzhi

    2016-01-01

    Leptospirosis, caused by pathogenic Leptospira spp., has recently been recognized as an emerging infectious disease worldwide. Despite its severity and global importance, knowledge about the molecular pathogenesis and virulence evolution of Leptospira spp. remains limited. Here we sequenced and analyzed 102 isolates representing global sources. A high genomic variability were observed among different Leptospira species, which was attributed to massive gene gain and loss events allowing for adaptation to specific niche conditions and changing host environments. Horizontal gene transfer and gene duplication allowed the stepwise acquisition of virulence factors in pathogenic Leptospira evolved from a recent common ancestor. More importantly, the abundant expansion of specific virulence-related protein families, such as metalloproteases-associated paralogs, were exclusively identified in pathogenic species, reflecting the importance of these protein families in the pathogenesis of leptospirosis. Our observations also indicated that positive selection played a crucial role on this bacteria adaptation to hosts. These novel findings may lead to greater understanding of the global diversity and virulence evolution of Leptospira spp. PMID:26833181

  1. Novel Fungal Pathogenicity and Leaf Defense Strategies Are Revealed by Simultaneous Transcriptome Analysis of Colletotrichum fructicola and Strawberry Infected by This Fungus

    Directory of Open Access Journals (Sweden)

    Liqing Zhang

    2018-04-01

    Full Text Available Colletotrichum fructicola, which is part of the C. gloeosporioides species complex, can cause anthracnose diseases in strawberries worldwide. However, the molecular interactions between C. fructicola and strawberry are largely unknown. A deep RNA-sequencing approach was applied to gain insights into the pathogenicity mechanisms of C. fructicola and the defense response of strawberry plants at different stages of infection. The transcriptome data showed stage-specific transcription accompanied by a step-by-step strawberry defense response and the evasion of this defense system by fungus. Fungal genes involved in plant cell wall degradation, secondary metabolism, and detoxification were up-regulated at different stage of infection. Most importantly, C. fructicola infection was accompanied by a large number of highly expressed effectors. Four new identified effectors function in the suppression of Bax-mediated programmed cell death. Strawberry utilizes pathogen-associated molecular patterns (PAMP-triggered immunity and effector-triggered immunity to prevent C. fructicola invasion, followed by the initiation of downstream innate immunity. The up-regulation of genes related to salicylic acid provided evidence that salicylic acid signaling may serve as the core defense signaling mechanism, while jasmonic acid and ethylene pathways were largely inhibited by C. fructicola. The necrotrophic stage displayed a significant up-regulation of genes involved in reactive oxygen species activation. Collectively, the transcriptomic data of both C. fructicola and strawberry shows that even though plants build a multilayered defense against infection, C. fructicola employs a series of escape or antagonizing mechanisms to successfully infect host cells.

  2. The next step in gene delivery: molecular engineering of adeno-associated virus serotypes.

    Science.gov (United States)

    Wang, Jinhui; Faust, Susan M; Rabinowitz, Joseph E

    2011-05-01

    Delivery is at the heart of gene therapy. Viral DNA delivery systems are asked to avoid the immune system, transduce specific target cell types while avoiding other cell types, infect dividing and non-dividing cells, insert their cargo within the host genome without mutagenesis or to remain episomal, and efficiently express transgenes for a substantial portion of a lifespan. These sought-after features cannot be associated with a single delivery system, or can they? The Adeno-associated virus family of gene delivery vehicles has proven to be highly malleable. Pseudotyping, using AAV serotype 2 terminal repeats to generate designer shells capable of transducing selected cell types, enables the packaging of common genomes into multiple serotypes virions to directly compare gene expression and tropism. In this review the ability to manipulate this virus will be examined from the inside out. The influence of host cell factors and organism biology including the immune response on the molecular fate of the viral genome will be discussed as well as differences in cellular trafficking patterns and uncoating properties that influence serotype transduction. Re-engineering the prototype vector AAV2 using epitope insertion, chemical modification, and molecular evolution not only demonstrated the flexibility of the best-studied serotype, but now also expanded the tool kit for molecular modification of all AAV serotypes. Current AAV research has changed its focus from examination of wild-type AAV biology to the feedback of host cell/organism on the design and development of a new generation of recombinant AAV delivery vehicles. This article is part of a Special Section entitled "Special Section: Cardiovascular Gene Therapy". Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Alix M Denoncourt

    2014-05-01

    Full Text Available Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse.

  4. PHIDIAS: a pathogen-host interaction data integration and analysis system.

    Science.gov (United States)

    Xiang, Zuoshuang; Tian, Yuying; He, Yongqun

    2007-01-01

    The Pathogen-Host Interaction Data Integration and Analysis System (PHIDIAS) is a web-based database system that serves as a centralized source to search, compare, and analyze integrated genome sequences, conserved domains, and gene expression data related to pathogen-host interactions (PHIs) for pathogen species designated as high priority agents for public health and biological security. In addition, PHIDIAS allows submission, search and analysis of PHI genes and molecular networks curated from peer-reviewed literature. PHIDIAS is publicly available at http://www.phidias.us.

  5. Chromatin versus pathogens: the function of epigenetics in plant immunity

    Science.gov (United States)

    Ding, Bo; Wang, Guo-Liang

    2015-01-01

    To defend against pathogens, plants have developed a sophisticated innate immunity that includes effector recognition, signal transduction, and rapid defense responses. Recent evidence has demonstrated that plants utilize the epigenetic control of gene expression to fine-tune their defense when challenged by pathogens. In this review, we highlight the current understanding of the molecular mechanisms of histone modifications (i.e., methylation, acetylation, and ubiquitination) and chromatin remodeling that contribute to plant immunity against pathogens. Functions of key histone-modifying and chromatin remodeling enzymes are discussed. PMID:26388882

  6. Diffusible signal factor-dependent quorum sensing in pathogenic bacteria and its exploitation for disease control.

    Science.gov (United States)

    Dow, J M

    2017-01-01

    Cell-to-cell signals of the diffusible signal factor (DSF) family are cis-2-unsaturated fatty acids of differing chain length and branching pattern. DSF signalling has been described in diverse bacteria to include plant and human pathogens where it acts to regulate functions such as biofilm formation, antibiotic tolerance and the production of virulence factors. DSF family signals can also participate in interspecies signalling with other bacteria and interkingdom signalling such as with the yeast Candida albicans. Interference with DSF signalling may afford new opportunities for the control of bacterial disease. Such strategies will depend in part on detailed knowledge of the molecular mechanisms underlying the processes of signal synthesis, perception and turnover. Here, I review both recent progress in understanding DSF signalling at the molecular level and prospects for translating this knowledge into approaches for disease control. © 2016 The Society for Applied Microbiology.

  7. Proteomics of Plant Pathogenic Fungi

    Directory of Open Access Journals (Sweden)

    Raquel González-Fernández

    2010-01-01

    Full Text Available Plant pathogenic fungi cause important yield losses in crops. In order to develop efficient and environmental friendly crop protection strategies, molecular studies of the fungal biological cycle, virulence factors, and interaction with its host are necessary. For that reason, several approaches have been performed using both classical genetic, cell biology, and biochemistry and the modern, holistic, and high-throughput, omic techniques. This work briefly overviews the tools available for studying Plant Pathogenic Fungi and is amply focused on MS-based Proteomics analysis, based on original papers published up to December 2009. At a methodological level, different steps in a proteomic workflow experiment are discussed. Separate sections are devoted to fungal descriptive (intracellular, subcellular, extracellular and differential expression proteomics and interactomics. From the work published we can conclude that Proteomics, in combination with other techniques, constitutes a powerful tool for providing important information about pathogenicity and virulence factors, thus opening up new possibilities for crop disease diagnosis and crop protection.

  8. Dynamic signature of molecular association in methanol

    International Nuclear Information System (INIS)

    Bertrand, C. E.; Copley, J. R. D.; Faraone, A.; Self, J. L.

    2016-01-01

    Quasielastic neutron scattering measurements and molecular dynamics simulations were combined to investigate the collective dynamics of deuterated methanol, CD 3 OD. In the experimentally determined dynamic structure factor, a slow, non-Fickian mode was observed in addition to the standard density-fluctuation heat mode. The simulation results indicate that the slow dynamical process originates from the hydrogen bonding of methanol molecules. The qualitative behavior of this mode is similar to the previously observed α-relaxation in supercooled water [M. C. Bellissent-Funel et al., Phys. Rev. Lett. 85, 3644 (2000)] which also originates from the formation and dissolution of hydrogen-bonded associates (supramolecular clusters). In methanol, however, this mode is distinguishable well above the freezing transition. This finding indicates that an emergent slow mode is not unique to supercooled water, but may instead be a general feature of hydrogen-bonding liquids and associating molecular liquids.

  9. Aquaporins facilitate hydrogen peroxide entry into guard cells to mediate ABA- and pathogen-triggered stomatal closure.

    Science.gov (United States)

    Rodrigues, Olivier; Reshetnyak, Ganna; Grondin, Alexandre; Saijo, Yusuke; Leonhardt, Nathalie; Maurel, Christophe; Verdoucq, Lionel

    2017-08-22

    Stomatal movements are crucial for the control of plant water status and protection against pathogens. Assays on epidermal peels revealed that, similar to abscisic acid (ABA), pathogen-associated molecular pattern (PAMP) flg22 requires the At PIP2;1 aquaporin to induce stomatal closure. Flg22 also induced an increase in osmotic water permeability ( P f ) of guard cell protoplasts through activation of At PIP2;1. The use of HyPer, a genetic probe for intracellular hydrogen peroxide (H 2 O 2 ), revealed that both ABA and flg22 triggered an accumulation of H 2 O 2 in wild-type but not pip2;1 guard cells. Pretreatment of guard cells with flg22 or ABA facilitated the influx of exogenous H 2 O 2 Brassinosteroid insensitive 1-associated receptor kinase 1 (BAK1) and open stomata 1 (OST1)/Snf1-related protein kinase 2.6 (SnRK2.6) were both necessary to flg22-induced P f and both phosphorylated At PIP2;1 on Ser121 in vitro. Accumulation of H 2 O 2 and stomatal closure as induced by flg22 was restored in pip2;1 guard cells by a phosphomimetic form (Ser121Asp) but not by a phosphodeficient form (Ser121Ala) of At PIP2;1. We propose a mechanism whereby phosphorylation of At PIP2;1 Ser121 by BAK1 and/or OST1 is triggered in response to flg22 to activate its water and H 2 O 2 transport activities. This work establishes a signaling role of plasma membrane aquaporins in guard cells and potentially in other cellular context involving H 2 O 2 signaling.

  10. DNA fusion gene vaccines

    DEFF Research Database (Denmark)

    Holst, Peter Johannes; Bassi, Maria Rosaria; Thomsen, Allan Randrup

    2010-01-01

    DNA vaccines are versatile and safe, but limited immunogenicity has prevented their use in the clinical setting. Experimentally, immunogenicity may be enhanced by the use of new delivery technologies, by coadministration of cytokines and pathogen-associated molecular patterns, or by fusion...... of antigens into molecular domains that enhance antigen presentation. More specifically, the immunogenicity of DNA vaccines may benefit from increased protein synthesis, increased T-cell help and MHC class I presentation, and the addition of a range of specific cytokines and pathogen-associated molecular...... with viral-vectored vaccines, various synergistic components may need to be incorporated into DNA vaccines. From the perspective of the future clinical use of DNA vaccines, it has been suggested that antigen presentation should be improved and cytokine coadministration attempted. However, even...

  11. Danger Signals Activating the Immune Response after Trauma

    Directory of Open Access Journals (Sweden)

    Stefanie Hirsiger

    2012-01-01

    Full Text Available Sterile injury can cause a systemic inflammatory response syndrome (SIRS that resembles the host response during sepsis. The inflammatory response following trauma comprises various systems of the human body which are cross-linked with each other within a highly complex network of inflammation. Endogenous danger signals (danger-associated molecular patterns; DAMPs; alarmins as well as exogenous pathogen-associated molecular patterns (PAMPs play a crucial role in the initiation of the immune response. With popularization of the “danger theory,” numerous DAMPs and PAMPs and their corresponding pathogen-recognition receptors have been identified. In this paper, we highlight the role of the DAMPs high-mobility group box protein 1 (HMGB1, interleukin-1α (IL-1α, and interleukin-33 (IL-33 as unique dual-function mediators as well as mitochondrial danger signals released upon cellular trauma and necrosis.

  12. Are food patterns associated with prostate cancer in Jamaican men: a preliminary report.

    Science.gov (United States)

    Jackson, Maria; Walker, Susan; Simpson, Candace; McFarlane-Anderson, Norma; Bennett, Franklyn

    2009-02-10

    Morbidity and mortality data highlight prostate cancer as the most commonly diagnosed neoplasm in Jamaican males. This report examines the association between dietary patterns and risk of prostate cancer in Jamaican men. Case-control study of 204 histologically confirmed newly diagnosed prostate cancer cases and 204 individually matched urology clinic controls in Jamaica, 2004 - 2007. Diet was assessed by food frequency questionnaire. Factor analysis yielded four dietary patterns: (i) a "healthy" pattern of vegetables, fruits and peas and beans, (ii) a "carbohydrate" pattern with high loadings for white bread and refined cereals, (iii) "sugary foods and sweet baked products" pattern and (iv) a "organ meat and fast food pattern" with high loadings for high fat dessert, organ meat, fast food and salty snacks.Logistic regressions with the individual dietary patterns controlling for potential confounders showed no association between any of the food patterns and risk of prostate cancer. The healthy pattern showed an inverse non-significant association, whereas the carbohydrate pattern was positively and insignificantly related to prostate cancer. Analysis of all food patterns adjusting for each other revealed no association between food patterns and the risk of prostate cancer. Dietary patterns identified in our sample were not associated with risk of prostate cancer. Further investigations that better define cancer-free subjects and dietary measurements are needed to examine diet and prostate cancer outcomes.

  13. Clinical and taxonomic status of pathogenic nonpigmented or late-pigmenting rapidly growing mycobacteria.

    Science.gov (United States)

    Brown-Elliott, Barbara A; Wallace, Richard J

    2002-10-01

    The history, taxonomy, geographic distribution, clinical disease, and therapy of the pathogenic nonpigmented or late-pigmenting rapidly growing mycobacteria (RGM) are reviewed. Community-acquired disease and health care-associated disease are highlighted for each species. The latter grouping includes health care-associated outbreaks and pseudo-outbreaks as well as sporadic disease cases. Treatment recommendations for each species and type of disease are also described. Special emphasis is on the Mycobacterium fortuitum group, including M. fortuitum, M. peregrinum, and the unnamed third biovariant complex with its recent taxonomic changes and newly recognized species (including M. septicum, M. mageritense, and proposed species M. houstonense and M. bonickei). The clinical and taxonomic status of M. chelonae, M. abscessus, and M. mucogenicum is also detailed, along with that of the closely related new species, M. immunogenum. Additionally, newly recognized species, M. wolinskyi and M. goodii, as well as M. smegmatis sensu stricto, are included in a discussion of the M. smegmatis group. Laboratory diagnosis of RGM using phenotypic methods such as biochemical testing and high-performance liquid chromatography and molecular methods of diagnosis are also discussed. The latter includes PCR-restriction fragment length polymorphism analysis, hybridization, ribotyping, and sequence analysis. Susceptibility testing and antibiotic susceptibility patterns of the RGM are also annotated, along with the current recommendations from the National Committee for Clinical Laboratory Standards (NCCLS) for mycobacterial susceptibility testing.

  14. Immunothrombotic Activity of Damage-Associated Molecular Patterns and Extracellular Vesicles in Secondary Organ Failure Induced by Trauma and Sterile Insults

    Directory of Open Access Journals (Sweden)

    John Eppensteiner

    2018-02-01

    Full Text Available Despite significant improvements in injury prevention and emergency response, injury-related death and morbidity continues to increase in the US and worldwide. Patients with trauma, invasive operations, anti-cancer treatment, and organ transplantation produce a host of danger signals and high levels of pro-inflammatory and pro-thrombotic mediators, such as damage-associated molecular patterns (DAMPs and extracellular vesicles (EVs. DAMPs (e.g., nucleic acids, histone, high-mobility group box 1 protein, and S100 are molecules released from injured, stressed, or activated cells that act as endogenous ligands of innate immune receptors, whereas EVs (e.g., microparticle and exosome are membranous vesicles budding off from plasma membranes and act as messengers between cells. DAMPs and EVs can stimulate multiple innate immune signaling pathways and coagulation cascades, and uncontrolled DAMP and EV production causes systemic inflammatory and thrombotic complications and secondary organ failure (SOF. Thus, DAMPs and EVs represent potential therapeutic targets and diagnostic biomarkers for SOF. High plasma levels of DAMPs and EVs have been positively correlated with mortality and morbidity of patients or animals with trauma or surgical insults. Blocking or neutralizing DAMPs using antibodies or small molecules has been demonstrated to ameliorate sepsis and SOF in animal models. Furthermore, a membrane immobilized with nucleic acid-binding polymers captured and removed multiple DAMPs and EVs from extracellular fluids, thereby preventing the onset of DAMP- and EV-induced inflammatory and thrombotic complications in vitro and in vivo. In this review, we will summarize the current state of knowledge of DAMPs, EVs, and SOF and discuss potential therapeutics and preventive intervention for organ failure secondary to trauma, surgery, anti-cancer therapy, and allogeneic transplantation.

  15. Compatible solutes: the key to Listeria's success as a versatile gastrointestinal pathogen?

    LENUS (Irish Health Repository)

    Sleator, Roy D

    2010-12-10

    Abstract Recently we reported a role for compatible solute uptake in mediating bile tolerance and increased gastrointestinal persistence in the foodborne pathogen Listeria monocytogenes 1 . Herein, we review the evolution in our understanding of how these low molecular weight molecules contribute to growth and survival of the pathogen both inside and outside the body, and how this stress survival mechanism may ultimately be used to target and kill the pathogen.

  16. An Evaluation of Factors Associated With Pathogenic PRSS1, SPINK1, CTFR, and/or CTRC Genetic Variants in Patients With Idiopathic Pancreatitis.

    Science.gov (United States)

    Jalaly, Niloofar Y; Moran, Robert A; Fargahi, Farshid; Khashab, Mouen A; Kamal, Ayesha; Lennon, Anne Marie; Walsh, Christi; Makary, Martin A; Whitcomb, David C; Yadav, Dhiraj; Cebotaru, Liudmila; Singh, Vikesh K

    2017-08-01

    We evaluated factors associated with pathogenic genetic variants in patients with idiopathic pancreatitis. Genetic testing (PRSS1, CFTR, SPINK1, and CTRC) was performed in all eligible patients with idiopathic pancreatitis between 2010 to 2015. Patients were classified into the following groups based on a review of medical records: (1) acute recurrent idiopathic pancreatitis (ARIP) with or without underlying chronic pancreatitis; (2) idiopathic chronic pancreatitis (ICP) without a history of ARP; (3) an unexplained first episode of acute pancreatitis (AP)pancreatitis. Logistic regression analysis was used to determine the factors associated with pathogenic genetic variants. Among 197 ARIP and/or ICP patients evaluated from 2010 to 2015, 134 underwent genetic testing. A total of 88 pathogenic genetic variants were found in 64 (47.8%) patients. Pathogenic genetic variants were identified in 58, 63, and 27% of patients with ARIP, an unexplained first episode of AP <35 years of age, and ICP without ARP, respectively. ARIP (OR: 18.12; 95% CI: 2.16-151.87; P=0.008) and an unexplained first episode of AP<35 years of age (OR: 2.46; 95% CI: 1.18-5.15; P=0.017), but not ICP, were independently associated with pathogenic genetic variants in the adjusted analysis. Pathogenic genetic variants are most likely to be identified in patients with ARIP and an unexplained first episode of AP<35 years of age. Genetic testing in these patient populations may delineate an etiology and prevent unnecessary diagnostic testing and procedures.

  17. A novel multiplex PCR assay for simultaneous detection of nine clinically significant bacterial pathogens associated with bovine mastitis.

    Science.gov (United States)

    Ashraf, Aqeela; Imran, Muhammad; Yaqub, Tahir; Tayyab, Muhammad; Shehzad, Wasim; Thomson, Peter C

    2017-06-01

    For rapid and simultaneous detection of nine bovine mastitic pathogens, a sensitive and specific multiplex PCR assay was developed. The assay was standardized using reference strains and validated on mastitic milk cultures which were identified to species level based on 16S rRNA sequencing. Multiplex PCR assay also efficiently detected the target bacterial strains directly from milk. The detection limit of the assay was up to 50 pg for DNA isolated from pure cultures and 10 4  CFU/ml for spiked milk samples. As estimated by latent class analysis, the assay was sensitive up to 88% and specific up to 98% for targeted mastitic pathogens, compared with the bacterial culture method and the 16S rRNA sequence analysis. This novel molecular assay could be useful for monitoring and maintaining the bovine udder health, ensuring the bacteriological safety of milk, and conducting epidemiological studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. FANCA Gene Mutations with 8 Novel Molecular Changes in Indian Fanconi Anemia Patients.

    Directory of Open Access Journals (Sweden)

    Avani Solanki

    Full Text Available Fanconi anemia (FA, a rare heterogeneous genetic disorder, is known to be associated with 19 genes and a spectrum of clinical features. We studied FANCA molecular changes in 34 unrelated and 2 siblings of Indian patients with FA and have identified 26 different molecular changes of FANCA gene, of which 8 were novel mutations (a small deletion c.2500delC, 4 non-sense mutations c.2182C>T, c.2630C>G, c.3677C>G, c.3189G>A; and 3 missense mutations; c.1273G>C, c.3679 G>C, and c.3992 T>C. Among these only 16 patients could be assigned FA-A complementation group, because we could not confirm single exon deletions detected by MLPA or cDNA amplification by secondary confirmation method and due to presence of heterozygous non-pathogenic variations or heterozygous pathogenic mutations. An effective molecular screening strategy should be developed for confirmation of these mutations and determining the breakpoints for single exon deletions.

  19. FANCA Gene Mutations with 8 Novel Molecular Changes in Indian Fanconi Anemia Patients.

    Science.gov (United States)

    Solanki, Avani; Mohanty, Purvi; Shukla, Pallavi; Rao, Anita; Ghosh, Kanjaksha; Vundinti, Babu Rao

    2016-01-01

    Fanconi anemia (FA), a rare heterogeneous genetic disorder, is known to be associated with 19 genes and a spectrum of clinical features. We studied FANCA molecular changes in 34 unrelated and 2 siblings of Indian patients with FA and have identified 26 different molecular changes of FANCA gene, of which 8 were novel mutations (a small deletion c.2500delC, 4 non-sense mutations c.2182C>T, c.2630C>G, c.3677C>G, c.3189G>A; and 3 missense mutations; c.1273G>C, c.3679 G>C, and c.3992 T>C). Among these only 16 patients could be assigned FA-A complementation group, because we could not confirm single exon deletions detected by MLPA or cDNA amplification by secondary confirmation method and due to presence of heterozygous non-pathogenic variations or heterozygous pathogenic mutations. An effective molecular screening strategy should be developed for confirmation of these mutations and determining the breakpoints for single exon deletions.

  20. Patterns of Physician-Patient Communication Associated with Patient Satisfaction.

    Science.gov (United States)

    Williams, M. Lee; Clampitt, Phillip G.

    Using data drawn from ten initial physician/patient interviews, an original category system was employed to analyze patterns of physician/patient communication. Static analysis, interaction analysis, and Markov chain analysis were used to discover the underlying communication patterns associated with patient satisfaction. Results revealed that…

  1. Molecular, morphological and pathogenic characterization of six strains of Metarhizium spp. (Deuteromycotina: Hyphomycetes for the control of Aegorhinus superciliosus (Coleoptera: Curculionidae

    Directory of Open Access Journals (Sweden)

    María Sepúlveda

    2016-03-01

    Full Text Available Aegorhinus superciliosus is an important pest on blueberry (Vaccinium corymbosum L. and other fruit trees. The use of entomopathogenic fungi as Metarhizium spp. has been evaluated for the control of this insect, but variability has been observed among different strains. The aim of this study was to characterize six promising strains of Metarhizium spp. for the control of A. superciliosus. The studied strains were QuM173c, Qu-M363, Qu-M171a, Qu-M156a, Qu-M421, and Qu-M430, all of which belonged to the Chilean Collection of Microbial Genetic Resources (ChCMGR of the Institute de Investigaciones Agropecuarias (INIA, Chile. Molecular characterization was made by sequencing the ITS region (Internal Transcribed Spacers, ITS-5.8S rDNA. The morphology of conidia was evaluated through scanning electron microscopy and radial colony growth was evaluated in potato dextrose agar (PDA, Sabouraud dextrose agar (SDA, agar enriched with larvae of Galleria mellonella (Lepidoptera: Pyralidae (GA, and agar enriched with adults of A. superciliosus (AA. Pathogenicity was studied based on mortality of adults of A. superciliosus inoculated with conidia. Sequencing of the ITS-5.8S rDNA region indicates that the strains belong to the clade of M. anisopliae var. anisopliae, except for Qu-M171a, which was identified as M. anisopliae var. lepidiotum. Conidia average length for the six strains was 5.09 pm and average conidia width was 1.92 pm. Radial colony growth differences were observed between strains (p < 0.01 and between different growth media (p < 0.01. The strains exhibited the highest colony growth in the GA medium, while in the AA medium they showed the lowest (p < 0.01. Pathogenicity tests show that Qu-M430 reached a 90% mortality rate (p < 0.01. Results show that there is variability between the studied strains, which is expressed in their morphology, molecular characteristics and pathogenicity towards A. superciliosus.

  2. Protein expression profile and prevalence pattern of the molecular classes of breast cancer - a Saudi population based study

    International Nuclear Information System (INIS)

    Al Tamimi, Dalal M; Shawarby, Mohamed A; Ahmed, Ayesha; Hassan, Ammar K; AlOdaini, Amal A

    2010-01-01

    Breast cancer is not a single entity but a diverse group of entities. Advances in gene expression profiling and immunohistochemistry as its surrogate marker have led to the unmasking of new breast cancer molecular subtypes, resulting in the emergence of more elaborate classification systems that are therapeutically and prognostically more predictive. Molecular class distribution across various ethnic groups may also reveal variations that can lead to different clinical outcomes in different populations. We aimed to analyze the spectrum of molecular subtypes present in the Saudi population. ER, PR, HER2, EGFR and CK5/6 were used as surrogate markers for gene expression profiling to classify 231 breast cancer specimens. Correlation of each molecular class with Ki-67 proliferation index, p53 mutation status, histologic type and grade of the tumor was also carried out. Out of 231 cases 9 (3.9%) were classified as luminal A (strong ER +ve, PR +ve or -ve), 37 (16%) as luminal B (weak to moderate ER +ve, and/or PR +ve), 40 (17.3%) as HER2+ (strong or moderately positive HER 2 with confirmation by silver enhanced in-situ hybridization) and 23 (10%) as basal (CK5/6 or EGFR +ve). Co-positivity of different markers in varied patterns was seen in 23 (10%) of cases which were grouped into a hybrid category comprising luminal B-HER2, HER2-basal and luminal-basal hybrids. Ninety nine (42.8%) of the tumors were negative for all five immunohistochemical markers and were labelled as unclassified (penta negative). A high Ki-67 proliferation index was seen in basal (p = 0.007) followed by HER2+ class. Overexpression of p53 was predominantly seen in HER2 + (p = 0.001) followed by the basal group of tumors. A strong correlation was noted between invasive lobular carcinoma and hormone receptor expression with 8 out of 9 lobular carcinoma cases (88.9%) classifiable as luminal cancers. Otherwise, there was no association between the molecular class and the histologic type or grade of the

  3. Molecular insights into the origin of the Hox-TALE patterning system.

    Science.gov (United States)

    Hudry, Bruno; Thomas-Chollier, Morgane; Volovik, Yael; Duffraisse, Marilyne; Dard, Amélie; Frank, Dale; Technau, Ulrich; Merabet, Samir

    2014-03-18

    Despite tremendous body form diversity in nature, bilaterian animals share common sets of developmental genes that display conserved expression patterns in the embryo. Among them are the Hox genes, which define different identities along the anterior-posterior axis. Hox proteins exert their function by interaction with TALE transcription factors. Hox and TALE members are also present in some but not all non-bilaterian phyla, raising the question of how Hox-TALE interactions evolved to provide positional information. By using proteins from unicellular and multicellular lineages, we showed that these networks emerged from an ancestral generic motif present in Hox and other related protein families. Interestingly, Hox-TALE networks experienced additional and extensive molecular innovations that were likely crucial for differentiating Hox functions along body plans. Together our results highlight how homeobox gene families evolved during eukaryote evolution to eventually constitute a major patterning system in Eumetazoans. DOI: http://dx.doi.org/10.7554/eLife.01939.001.

  4. Genetic Diversity Studies Based on Morphological Variability, Pathogenicity and Molecular Phylogeny of the Sclerotinia sclerotiorum Population From Indian Mustard (Brassica juncea

    Directory of Open Access Journals (Sweden)

    Pankaj Sharma

    2018-06-01

    Full Text Available White mold or stem rot disease are ubiquitously distributed throughout the world and the causal organism of this disease Sclerotinia sclerotiorum (Lib. de Bary, is known to infect over 400 plant species. Sclerotinia stem rot is one of the most devastating fungal diseases and poses a serious threat to the worldwide cultivation of oilseed Brassica including India. S. sclerotiorum pathogen usually infects the stem but in severe cases leaves and pods also affected at different developmental stages that deteriorate not only the oil quality but also causing the seed and oil yield losses up to 90% depending on the severity of the disease infestation. This study investigated the morphological and molecular characterization of pathogenic S. sclerotiorum (Lib de Bary geographical isolates from oilseed Brassica including Brassica juncea (Indian mustard. The aim of this study was to compare isolates of S. sclerotiorum originated from different agro-climatic conditions and to analyse similarity or differences between them as well as to examine the virulence of this pathogen specifically in Brassica for the first time. The collection of S. sclerotiorum isolates from symptomatic Brassica plants was done and analyzed for morphological features, and molecular characterization. The virulence evaluation test of 65 isolates on four Brassica cultivars has shown 5 of them were highly virulent, 46 were virulent and 14 were moderately virulent. Phylogenetic analysis encompassing all the morphological features, SSR polymorphism, and ITS sequencing has shown the existence of high genetic diversity among the isolates that categorized all the isolates in three evolutionary lineages in the derived dendrogram. Further, genetic variability analysis based on sequences variation in ITS region of all the isolates has shown the existence of either insertions or deletions of the nucleotides in the ITS region has led to the interspecies variability and observed the variation were

  5. Modulation of pathogen recognition by autophagy

    Directory of Open Access Journals (Sweden)

    Ji Eun eOh

    2012-03-01

    Full Text Available Autophagy is an ancient biological process for maintaining cellular homeostasis by degradation of long-lived cytosolic proteins and organelles. Recent studies demonstrated that autophagy is availed by immune cells to regulate innate immunity. On the one hand, cells exert direct effector function by degrading intracellular pathogens; on the other hand, autophagy modulates pathogen recognition and downstream signaling for innate immune responses. Pathogen recognition via pattern recognition receptors induces autophagy. The function of phagocytic cells is enhanced by recruitment of autophagy-related proteins. Moreover, autophagy acts as a delivery system for viral replication complexes to migrate to the endosomal compartments where virus sensing occurs. In another case, key molecules of the autophagic pathway have been found to negatively regulate immune signaling, thus preventing aberrant activation of cytokine production and consequent immune responses. In this review, we focus on the recent advances in the role of autophagy in pathogen recognition and modulation of innate immune responses.

  6. What's the risk? Identifying potential human pathogens within grey-headed flying foxes faeces.

    Directory of Open Access Journals (Sweden)

    Rebekah Henry

    Full Text Available Pteropus poliocephalus (grey-headed flying foxes are recognised vectors for a range of potentially fatal human pathogens. However, to date research has primarily focused on viral disease carriage, overlooking bacterial pathogens, which also represent a significant human disease risk. The current study applied 16S rRNA amplicon sequencing, community analysis and a multi-tiered database OTU picking approach to identify faecal-derived zoonotic bacteria within two colonies of P. poliocephalus from Victoria, Australia. Our data show that sequences associated with Enterobacteriaceae (62.8% ± 24.7%, Pasteurellaceae (19.9% ± 25.7% and Moraxellaceae (9.4% ± 11.8% dominate flying fox faeces. Further colony specific differences in bacterial faecal colonisation patterns were also identified. In total, 34 potential pathogens, representing 15 genera, were identified. However, species level definition was only possible for Clostridium perfringens, which likely represents a low infectious risk due to the low proportion observed within the faeces and high infectious dose required for transmission. In contrast, sequences associated with other pathogenic species clusters such as Haemophilus haemolyticus-H. influenzae and Salmonella bongori-S. enterica, were present at high proportions in the faeces, and due to their relatively low infectious doses and modes of transmissions, represent a greater potential human disease risk. These analyses of the microbial community composition of Pteropus poliocephalus have significantly advanced our understanding of the potential bacterial disease risk associated with flying foxes and should direct future epidemiological and quantitative microbial risk assessments to further define the health risks presented by these animals.

  7. Association of Periodic and Rhythmic Electroencephalographic Patterns With Seizures in Critically Ill Patients.

    Science.gov (United States)

    Rodriguez Ruiz, Andres; Vlachy, Jan; Lee, Jong Woo; Gilmore, Emily J; Ayer, Turgay; Haider, Hiba Arif; Gaspard, Nicolas; Ehrenberg, J Andrew; Tolchin, Benjamin; Fantaneanu, Tadeu A; Fernandez, Andres; Hirsch, Lawrence J; LaRoche, Suzette

    2017-02-01

    Periodic and rhythmic electroencephalographic patterns have been associated with risk of seizures in critically ill patients. However, specific features that confer higher seizure risk remain unclear. To analyze the association of distinct characteristics of periodic and rhythmic patterns with seizures. We reviewed electroencephalographic recordings from 4772 critically ill adults in 3 academic medical centers from February 2013 to September 2015 and performed a multivariate analysis to determine features associated with seizures. Continuous electroencephalography. Association of periodic and rhythmic patterns and specific characteristics, such as pattern frequency (hertz), Plus modifier, prevalence, and stimulation-induced patterns, and the risk for seizures. Of the 4772 patients included in our study, 2868 were men and 1904 were women. Lateralized periodic discharges (LPDs) had the highest association with seizures regardless of frequency and the association was greater when the Plus modifier was present (58%; odds ratio [OR], 2.00, P rhythmic delta activity (LRDA) were associated with seizures in a frequency-dependent manner (1.5-2 Hz: GPDs, 24%,OR, 2.31, P = .02; LRDA, 24%, OR, 1.79, P = .05; ≥ 2 Hz: GPDs, 32%, OR, 3.30, P rhythmic delta activity compared with no periodic or rhythmic pattern (13%, OR, 1.18, P = .26). Higher prevalence of LPDs and GPDs also conferred increased seizure risk (37% frequent vs 45% abundant/continuous, OR, 1.64, P = .03 for difference; 8% rare/occasional vs 15% frequent, OR, 2.71, P = .03, vs 23% abundant/continuous, OR, 1.95, P = .04). Patterns associated with stimulation did not show an additional risk for seizures from the underlying pattern risk (P > .10). In this study, LPDs, LRDA, and GPDs were associated with seizures while generalized rhythmic delta activity was not. Lateralized periodic discharges were associated with seizures at all frequencies with and without Plus modifier, but LRDA and GPDs were associated with

  8. Aspergillus fumigatus conidial melanin modulates host cytokine response

    NARCIS (Netherlands)

    L.Y.A. Chai (Louis); M.G. Netea (Mihai); J. Sugui (Janyce); A.G. Vonk (Alieke); W.W.J. van de Sande (Wendy); A. Warris (Adilia); K.J. Kwon-Chung (Kyung); B. Jan Kullberg (Bart)

    2010-01-01

    textabstractMelanin biopigments have been linked to fungal virulence. Aspergillus fumigatus conidia are melanised and are weakly immunogenic. We show that melanin pigments on the surface of resting Aspergillus fumigatus conidia may serve to mask pathogen-associated molecular patterns (PAMPs)-induced

  9. Aspergillus fumigatus conidial melanin modulates host cytokine response.

    NARCIS (Netherlands)

    Chai, L.; Netea, M.G.; Sugui, J.; Vonk, A.G.; Sande, W.W. van de; Warris, A.; Kwon-Chung, K.J.; Kullberg, B.J.

    2010-01-01

    Melanin biopigments have been linked to fungal virulence. Aspergillus fumigatus conidia are melanised and are weakly immunogenic. We show that melanin pigments on the surface of resting Aspergillus fumigatus conidia may serve to mask pathogen-associated molecular patterns (PAMPs)-induced cytokine

  10. Evasion Mechanisms Used by Pathogens to Escape the Lectin Complement Pathway.

    Science.gov (United States)

    Rosbjerg, Anne; Genster, Ninette; Pilely, Katrine; Garred, Peter

    2017-01-01

    The complement system is a crucial defensive network that protects the host against invading pathogens. It is part of the innate immune system and can be initiated via three pathways: the lectin, classical and alternative activation pathway. Overall the network compiles a group of recognition molecules that bind specific patterns on microbial surfaces, a group of associated proteases that initiates the complement cascade, and a group of proteins that interact in proteolytic complexes or the terminal pore-forming complex. In addition, various regulatory proteins are important for controlling the level of activity. The result is a pro-inflammatory response meant to combat foreign microbes. Microbial elimination is, however, not a straight forward procedure; pathogens have adapted to their environment by evolving a collection of evasion mechanisms that circumvent the human complement system. Complement evasion strategies features different ways of exploiting human complement proteins and moreover features different pathogen-derived proteins that interfere with the normal processes. Accumulated, these mechanisms target all three complement activation pathways as well as the final common part of the cascade. This review will cover the currently known lectin pathway evasion mechanisms and give examples of pathogens that operate these to increase their chance of invasion, survival and dissemination.

  11. Hemolytic porcine intestinal Escherichia coli without virulence-associated genes typical of intestinal pathogenic E. coli.

    Science.gov (United States)

    Schierack, Peter; Weinreich, Joerg; Ewers, Christa; Tachu, Babila; Nicholson, Bryon; Barth, Stefanie

    2011-12-01

    Testing 1,666 fecal or intestinal samples from healthy and diarrheic pigs, we obtained hemolytic Escherichia coli isolates from 593 samples. Focusing on hemolytic E. coli isolates without virulence-associated genes (VAGs) typical for enteropathogens, we found that such isolates carried a broad variety of VAGs typical for extraintestinal pathogenic E. coli.

  12. Antibiotic resistance & pathogen profile in ventilator-associated pneumonia in a tertiary care hospital in India

    Directory of Open Access Journals (Sweden)

    Abhijit Chaudhury

    2016-01-01

    Results: VAP rates of 44.1, 43.8 and 26.3 were seen in 2011, 2012 and 2013, respectively. In all the three years, non-fermentative Gram-negative bacilli were the predominant organisms, followed by Pseudomonas spp. and Klebsiella spp. Staphylococcus aureus exhibited a downwards trend in prevalence from 50.0 per cent in 2011 to 34.9 per cent in 2013. An increase in vancomycin-resistant enterococci was seen from 4.3 per cent in 2012 to 8.3 per cent in 2013, while methicillin resistance amongst the S. aureus crossed the 50 per cent mark in 2013. An increasing trend in resistance was shown by Pseudomonas spp. for piperacillin-tazobactam (PTZ, amikacin and imipenem (IPM. For the non-fermenters, resistance frequency remained very high except for IPM (33.1% and polymyxin-B (2.4%. Interpretation & conclusions: Our findings show VAP as an important problem in the ICU setting. The incidence of multidrug-resistant pathogens was on the rise. The resistance pattern of these pathogens can help an institution to formulate effective antimicrobial policy. To have a comprehensive pan-India picture, multicentric studies are needed.

  13. Divergent pro-inflammatory profile of human dendritic cells in response to commensal and pathogenic bacteria associated with the airway microbiota

    DEFF Research Database (Denmark)

    Larsen, Jeppe Madura; Steen-Jensen, Daniel Bisgaard; Laursen, Janne Marie

    2012-01-01

    of individual bacterial species are unknown. In this study, we compared the immune stimulatory capacity on human monocyte-derived dendritic cells (DCs) of selected airway commensal and pathogenic bacteria predominantly associated with lungs of asthma or COPD patients (pathogenic Haemophillus spp. and Moraxella...... spp.), healthy lungs (commensal Prevotella spp.) or both (commensal Veillonella spp. and Actinomyces spp.). All bacteria were found to induce activation of DCs as demonstrated by similar induction of CD83, CD40 and CD86 surface expression. However, asthma and COPD-associated pathogenic bacteria...... provoked a 3-5 fold higher production of IL-23, IL-12p70 and IL-10 cytokines compared to the commensal bacteria. Based on the differential cytokine production profiles, the studied airway bacteria could be segregated into three groups (Haemophilus spp. and Moraxella spp. vs. Prevotella spp. and Veillonella...

  14. Molecular testing for viral and bacterial enteric pathogens: gold standard for viruses, but don't let culture go just yet?

    Science.gov (United States)

    Bloomfield, Maxim G; Balm, Michelle N D; Blackmore, Timothy K

    2015-04-01

    Contemporary diagnostic microbiology is increasingly adopting molecular methods as front line tests for a variety of samples. This trend holds true for detection of enteric pathogens (EP), where nucleic acid amplification tests (NAAT) for viruses are well established as the gold standard, and an increasing number of commercial multi-target assays are now available for bacteria and parasites. NAAT have significant sensitivity and turnaround time advantages over traditional methods, potentially returning same-day results. Multiplex panels offer an attractive 'one-stop shop' that may provide workflow and cost advantages to laboratories processing large sample volumes. However, there are a number of issues which need consideration. Reflex culture is required for antibiotic susceptibility testing and strain typing when needed for food safety and other epidemiological investigations. Surveillance systems will need to allow for differences in disease incidence due to the enhanced sensitivity of NAAT. Laboratories should be mindful of local epidemiology when selecting which pathogens to include in multiplex panels, and be thoughtful regarding which pathogens will not be detected. Multiplex panels may not be appropriate in certain situations, such as hospital-onset diarrhoea, where Clostridium difficile testing might be all that is required, and laboratories may wish to retain the flexibility to run single tests in such situations. The clinical impact of rapid results is also likely to be relatively minor, as infective diarrhoea is a self-limiting illness in the majority of cases. Laboratories will require strategies to assist users in the interpretation of the results produced by NAAT, particularly where pathogens are detected at low levels with uncertain clinical significance. These caveats aside, faecal NAAT are increasingly being used and introduce a new era of diagnosis of gastrointestinal infection.

  15. Adaptive Patterns of Mitogenome Evolution Are Associated with the Loss of Shell Scutes in Turtles.

    Science.gov (United States)

    Escalona, Tibisay; Weadick, Cameron J; Antunes, Agostinho

    2017-10-01

    The mitochondrial genome encodes several protein components of the oxidative phosphorylation (OXPHOS) pathway and is critical for aerobic respiration. These proteins have evolved adaptively in many taxa, but linking molecular-level patterns with higher-level attributes (e.g., morphology, physiology) remains a challenge. Turtles are a promising system for exploring mitochondrial genome evolution as different species face distinct respiratory challenges and employ multiple strategies for ensuring efficient respiration. One prominent adaptation to a highly aquatic lifestyle in turtles is the secondary loss of keratenized shell scutes (i.e., soft-shells), which is associated with enhanced swimming ability and, in some species, cutaneous respiration. We used codon models to examine patterns of selection on mitochondrial protein-coding genes along the three turtle lineages that independently evolved soft-shells. We found strong evidence for positive selection along the branches leading to the pig-nosed turtle (Carettochelys insculpta) and the softshells clade (Trionychidae), but only weak evidence for the leatherback (Dermochelys coriacea) branch. Positively selected sites were found to be particularly prevalent in OXPHOS Complex I proteins, especially subunit ND2, along both positively selected lineages, consistent with convergent adaptive evolution. Structural analysis showed that many of the identified sites are within key regions or near residues involved in proton transport, indicating that positive selection may have precipitated substantial changes in mitochondrial function. Overall, our study provides evidence that physiological challenges associated with adaptation to a highly aquatic lifestyle have shaped the evolution of the turtle mitochondrial genome in a lineage-specific manner. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. The contrasting roles of inflammasomes in cancer

    Science.gov (United States)

    He, Qin; Fu, Yu; Tian, Dean; Yan, Wei

    2018-01-01

    Chronic inflammation plays a decisive role at different stages of cancer development. Inflammasomes are oligomeric protein complexes activated in response to pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). PAMPs and DAMPs are released from infected cells, tumors and damaged tissues. Inflammasomes activate and release inflammatory cytokines such as IL-1β and IL-18. The various inflammasomes and inflammatory cytokines and chemokines play contrasting roles in cancer development and progression. In this review, we describe the roles of different inflammasomes in lung, breast, gastric, liver, colon, and prostate cancers and in glioblastomas.

  17. Potential relationship between phenotypic and molecular characteristics in revealing livestock-associated Staphylococcus aureus in Chinese humans without occupational livestock contact

    Directory of Open Access Journals (Sweden)

    Yanping Fan

    2016-09-01

    Full Text Available While some studies have defined Staphylococcus aureus based on its clonal complex and resistance pattern, few have explored the relations between the genetic lineages and antibiotic resistance patterns and immune evasion cluster (IEC genes. Our aim was to investigate the potential relationship between phenotypic and molecular characteristics so as to reveal livestock-associated S. aureus in humans. The study participants were interviewed, and they provided two nasal swabs for S. aureus analysis. All S. aureus and methicillin-resistant S. aureus (MRSA were tested for antibiotic susceptibility, multilocus sequence type and IEC genes. Of the 1162 participants, 9.3% carried S. aureus, including MRSA (1.4% and multidrug-resistant S. aureus (MDRSA, 2.8%. The predominant multidrug-resistant pattern among MDRSA isolates was nonsusceptibility to erythromycin, clindamycin and tetracycline. The most common S. aureus genotypes were ST7, ST6, ST188 and ST59, and the predominant MRSA genotype was ST7. Notably, the livestock-associated S. aureus isolates (IEC-negative CC9, IEC-negative tetracycline-resistant CC398, and IEC-negative tetracycline-resistant CC5 were found in people with no occupational livestock contact. These findings reveal a potential relationship between S. aureus CCs and IEC genes and antibiotic resistance patterns in defining livestock-associated S. aureus in humans and support growing concern about the potential livestock-to-human transmission of livestock-associated S. aureus by non-occupational livestock contact.

  18. Biochemistry and Molecular Biology of Flaviviruses.

    Science.gov (United States)

    Barrows, Nicholas J; Campos, Rafael K; Liao, Kuo-Chieh; Prasanth, K Reddisiva; Soto-Acosta, Ruben; Yeh, Shih-Chia; Schott-Lerner, Geraldine; Pompon, Julien; Sessions, October M; Bradrick, Shelton S; Garcia-Blanco, Mariano A

    2018-04-25

    Flaviviruses, such as dengue, Japanese encephalitis, tick-borne encephalitis, West Nile, yellow fever, and Zika viruses, are critically important human pathogens that sicken a staggeringly high number of humans every year. Most of these pathogens are transmitted by mosquitos, and not surprisingly, as the earth warms and human populations grow and move, their geographic reach is increasing. Flaviviruses are simple RNA-protein machines that carry out protein synthesis, genome replication, and virion packaging in close association with cellular lipid membranes. In this review, we examine the molecular biology of flaviviruses touching on the structure and function of viral components and how these interact with host factors. The latter are functionally divided into pro-viral and antiviral factors, both of which, not surprisingly, include many RNA binding proteins. In the interface between the virus and the hosts we highlight the role of a noncoding RNA produced by flaviviruses to impair antiviral host immune responses. Throughout the review, we highlight areas of intense investigation, or a need for it, and potential targets and tools to consider in the important battle against pathogenic flaviviruses.

  19. Molecular signatures associated with HCV-induced hepatocellular carcinoma and liver metastasis.

    Directory of Open Access Journals (Sweden)

    Valeria De Giorgi

    Full Text Available Hepatocellular carcinomas (HCCs are a heterogeneous group of tumors that differ in risk factors and genetic alterations. In Italy, particularly Southern Italy, chronic hepatitis C virus (HCV infection represents the main cause of HCC. Using high-density oligoarrays, we identified consistent differences in gene-expression between HCC and normal liver tissue. Expression patterns in HCC were also readily distinguishable from those associated with liver metastases. To characterize molecular events relevant to hepatocarcinogenesis and identify biomarkers for early HCC detection, gene expression profiling of 71 liver biopsies from HCV-related primary HCC and corresponding HCV-positive non-HCC hepatic tissue, as well as gastrointestinal liver metastases paired with the apparently normal peri-tumoral liver tissue, were compared to 6 liver biopsies from healthy individuals. Characteristic gene signatures were identified when normal tissue was compared with HCV-related primary HCC, corresponding HCV-positive non-HCC as well as gastrointestinal liver metastases. Pathway analysis classified the cellular and biological functions of the genes differentially expressed as related to regulation of gene expression and post-translational modification in HCV-related primary HCC; cellular Growth and Proliferation, and Cell-To-Cell Signaling and Interaction in HCV-related non HCC samples; Cellular Growth and Proliferation and Cell Cycle in metastasis. Also characteristic gene signatures were identified of HCV-HCC progression for early HCC diagnosis.A diagnostic molecular signature complementing conventional pathologic assessment was identified.

  20. Vibriophages and Their Interactions with the Fish Pathogen Vibrio anguillarum

    DEFF Research Database (Denmark)

    Tan, Demeng; Gram, Lone; Middelboe, Mathias

    2014-01-01

    Vibrio anguillarum is an important pathogen in aquaculture, responsible for the disease vibriosis in many fish and invertebrate species. Disease control by antibiotics is a concern due to potential development and spread of antibiotic resistance. The use of bacteriophages to control the pathogen...... patterns of the individual host isolates, key phenotypic properties related to phage susceptibility are distributed worldwide and maintained in the global Vibrio community for decades. The phage susceptibility pattern of the isolates did not show any relation to the physiological relationships obtained...... from Biolog GN2 profiles, demonstrating that similar phage susceptibility patterns occur across broad phylogenetic and physiological differences in Vibrio strains. Subsequent culture experiments with two phages and two V. anguillarum hosts demonstrated an initial strong lytic potential of the phages...