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Sample records for specific virulence traits

  1. In Vivo fitness associated with high virulence in a vertebrate virus is a complex trait regulated by host entry, replication, and shedding

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    Wargo, Andrew R.; Kurath, Gael

    2011-01-01

    The relationship between pathogen fitness and virulence is typically examined by quantifying only one or two pathogen fitness traits. More specifically, it is regularly assumed that within-host replication, as a precursor to transmission, is the driving force behind virulence. In reality, many traits contribute to pathogen fitness, and each trait could drive the evolution of virulence in different ways. Here, we independently quantified four viral infection cycle traits, namely, host entry, within-host replication, within-host coinfection fitness, and shedding, in vivo, in the vertebrate virus Infectious hematopoietic necrosis virus (IHNV). We examined how each of these stages of the viral infection cycle contributes to the fitness of IHNV genotypes that differ in virulence in rainbow trout. This enabled us to determine how infection cycle fitness traits are independently associated with virulence. We found that viral fitness was independently regulated by each of the traits examined, with the largest impact on fitness being provided by within-host replication. Furthermore, the more virulent of the two genotypes of IHNV we used had advantages in all of the traits quantified. Our results are thus congruent with the assumption that virulence and within-host replication are correlated but suggest that infection cycle fitness is complex and that replication is not the only trait associated with virulence.

  2. The expression and evolution of virulence in multiple infections: the role of specificity, relative virulence and relative dose.

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    Ben-Ami, Frida; Routtu, Jarkko

    2013-05-03

    Multiple infections of the same host by different strains of the same microparasite species are believed to play a crucial role during the evolution of parasite virulence. We investigated the role of specificity, relative virulence and relative dose in determining the competitive outcome of multiple infections in the Daphnia magna-Pasteuria ramosa host-parasite system. We found that infections by P. ramosa clones (single genotype) were less virulent and produced more spores than infections by P. ramosa isolates (possibly containing multiple genotypes). We also found that two similarly virulent isolates of P. ramosa differed considerably in their within-host competitiveness and their effects on host offspring production when faced with coinfecting P. ramosa isolates and clones. Although the relative virulence of a P. ramosa isolate/clone appears to be a good indicator of its competitiveness during multiple infections, the relative dose may alter the competitive outcome. Moreover, spore counts on day 20 post-infection indicate that the competitive outcome is largely decided early in the parasite's growth phase, possibly mediated by direct interference or apparent competition. Our results emphasize the importance of epidemiology as well as of various parasite traits in determining the outcome of within-host competition. Incorporating realistic epidemiological and ecological conditions when testing theoretical models of multiple infections, as well as using a wider range of host and parasite genotypes, will enable us to better understand the course of virulence evolution.

  3. Evaluating Different Virulence Traits of Klebsiella pneumoniae Using Dictyostelium discoideum and Zebrafish Larvae as Host Models

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    Andrés E. Marcoleta

    2018-02-01

    Full Text Available Multiresistant and invasive hypervirulent Klebsiella pneumoniae strains have become one of the most urgent bacterial pathogen threats. Recent analyses revealed a high genomic plasticity of this species, harboring a variety of mobile genetic elements associated with virulent strains, encoding proteins of unknown function whose possible role in pathogenesis have not been addressed. K. pneumoniae virulence has been studied mainly in animal models such as mice and pigs, however, practical, financial, ethical and methodological issues limit the use of mammal hosts. Consequently, the development of simple and cost-effective experimental approaches with alternative host models is needed. In this work we described the use of both, the social amoeba and professional phagocyte Dictyostelium discoideum and the fish Danio rerio (zebrafish as surrogate host models to study K. pneumoniae virulence. We compared three K. pneumoniae clinical isolates evaluating their resistance to phagocytosis, intracellular survival, lethality, intestinal colonization, and innate immune cells recruitment. Optical transparency of both host models permitted studying the infective process in vivo, following the Klebsiella-host interactions through live-cell imaging. We demonstrated that K. pneumoniae RYC492, but not the multiresistant strains 700603 and BAA-1705, is virulent to both host models and elicits a strong immune response. Moreover, this strain showed a high resistance to phagocytosis by D. discoideum, an increased ability to form biofilms and a more prominent and irregular capsule. Besides, the strain 700603 showed the unique ability to replicate inside amoeba cells. Genomic comparison of the K. pneumoniae strains showed that the RYC492 strain has a higher overall content of virulence factors although no specific genes could be linked to its phagocytosis resistance, nor to the intracellular survival observed for the 700603 strain. Our results indicate that both zebrafish

  4. Antibiotic resistance and virulence traits in clinical and environmental Enterococcus faecalis and Enterococcus faecium isolates.

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    Rathnayake, I U; Hargreaves, M; Huygens, F

    2012-07-01

    This study compared virulence and antibiotic resistance traits in clinical and environmental Enterococcus faecalis and Enterococcus faecium isolates. E. faecalis isolates harboured a broader spectrum of virulence determinants compared to E. faecium isolates. The virulence traits Cyl-A, Cyl-B, Cyl-M, gel-E, esp and acm were tested and environmental isolates predominantly harboured gel-E (80% of E. faecalis and 31.9% of E. faecium) whereas esp was more prevalent in clinical isolates (67.8% of E. faecalis and 70.4% of E. faecium). E. faecalis and E. faecium isolated from water had different antibiotic resistance patterns compared to those isolated from clinical samples. Linezolid resistance was not observed in any isolates tested and vancomycin resistance was observed only in clinical isolates. Resistance to other antibiotics (tetracycline, gentamicin, ciprofloxacin and ampicillin) was detected in both clinical and water isolates. Clinical isolates were more resistant to all the antibiotics tested compared to water isolates. Multi-drug resistance was more prevalent in clinical isolates (71.2% of E. faecalis and 70.3% of E. faecium) compared to water isolates (only 5.7% E. faecium). tet L and tet M genes were predominantly identified in tetracycline-resistant isolates. All water and clinical isolates resistant to ciprofloxacin and ampicillin contained mutations in the gyrA, parC and pbp5 genes. A significant correlation was found between the presence of virulence determinants and antibiotic resistance in all the isolates tested in this study (pantibiotic resistant enterococci, together with associated virulence traits, in surface recreational water could be a public health risk. Copyright © 2012 Elsevier GmbH. All rights reserved.

  5. Trait-specific dependence in romantic relationships.

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    Ellis, Bruce J; Simpson, Jeffry A; Campbell, Lorne

    2002-10-01

    Informed by three theoretical frameworks--trait psychology, evolutionary psychology, and interdependence theory--we report four investigations designed to develop and test the reliability and validity of a new construct and accompanying multiscale inventory, the Trait-Specific Dependence Inventory (TSDI). The TSDI assesses comparisons between present and alternative romantic partners on major dimensions of mate value. In Study 1, principal components analyses revealed that the provisional pool of theory-generated TSDI items were represented by six factors: Agreeable/Committed, Resource Accruing Potential, Physical Prowess, Emotional Stability, Surgency, and Physical Attractiveness. In Study 2, confirmatory factor analysis replicated these results on a different sample and tested how well different structural models fit the data. Study 3 provided evidence for the convergent and discriminant validity of the six TSDI scales by correlating each one with a matched personality trait scale that did not explicitly incorporate comparisons between partners. Study 4 provided further validation evidence, revealing that the six TSDI scales successfully predicted three relationship outcome measures--love, time investment, and anger/upset--above and beyond matched sets of traditional personality trait measures. These results suggest that the TSDI is a reliable, valid, and unique construct that represents a new trait-specific method of assessing dependence in romantic relationships. The construct of trait-specific dependence is introduced and linked with other theories of mate value.

  6. Virulence traits and antibiotic resistance among enterococci isolated from dogs with periodontal disease.

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    Oliveira, Manuela; Tavares, Marta; Gomes, Diana; Touret, Tiago; São Braz, Berta; Tavares, Luís; Semedo-Lemsaddek, Teresa

    2016-06-01

    Periodontal disease - PD - is one of the most widespread diseases in dogs, but the role of this odontogenic infection in the dissemination of pathogenic bacteria present in the oral mucosa to other animals or pet owners is understudied. Trying to unveil the putative pathogenicity of enterococci present in the gums of dogs diagnosed with PD, thirty-two animals were investigated during routine visits to a private veterinary clinic. Seventy-one enterococci were recovered and characterized regarding species, genomic variability, virulence traits, antimicrobial resistance and biofilm-forming ability. Isolates were mainly identified as Enterococcus faecalis, with the large majority (95%) being able to produce biofilm. Regarding antibiotic resistance, all dog-enterococci were susceptible to ampicillin, amoxicillin/clavulanate, gentamicin-120, imipenem and vancomycin; while distinct levels of resistance were observed for chloramphenicol (10%), erythromycin (20%), streptomycin-300 (35%) and tetracycline (95%). For virulence traits incidence levels of 35% were observed for β-hemolysis and 25% for cylA, 25% for gelatinase and 35% for gelE; 85% harbor efaAfs and ebpABC; while ace, agg and esp are present respectively in 50, 30 and 10% of the dog-enterococci; efaAfm and acm were detected in all the Enterococcus faecium. Overall, the widespread prevalence of PD in dogs, associated with the close contact between companion animals, other animals and humans, may act as source for the dissemination of opportunistic pathogenic bacteria. Hence, aforementioned data on virulence and resistance features, emphasizes the need for active surveillance measures, such as the diagnose of PD in companion animals during routine visits to the veterinary clinic. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Bacteriocinogenic potential and virulence traits of Enterococcus faecium and E. faecalis isolated from human milk

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    Khalkhali, Soodabeh; Mojgani, Naheed

    2017-01-01

    Background and Objectives: Human milk is a continuous supply of Lactic Acid bacteria (LAB), including enterococci with probiotic potentials. The aim of this study was to analyze two Enterococcus species, isolated from human milk for their probiotic potential, bacteriocin producing ability and virulence traits. Materials and Methods: Enterococcus faecium TA0033 and E. faecalis TA102 were tested for acid and bile tolerance, survival in simulated gastric and intestinal conditions. The antibacterial spectrum of the isolates was tested by agar well diffusion assay. The antagonistic agent was characterized by physico-chemical methods. The enterocin structural genes, virulence determinants, vancomycin resistance and biogenic amine genes, such as hdc1, hdc2, tdc, ldc and odc were also determined. Results: The tested isolates survived acidic conditions, high bile salt (1%), simulated gastric and intestinal conditions. The culture supernatant fluids of the two isolates inhibited the growth of Escherichia coli, Listeria monocytogenes, Salmonella typhi, Staphylococcus aureus, Shigella dysenteriae and Streptococcus agalactiae. The antagonistic activity was lost in the presence of proteolytic enzymes but tolerated the action of catalase, lysozyme and lipase. In contrast to enterocin TA102, enterocin TA0033 possessed bactericidal mode of action. Bacteriocin structural genes, entA and entB were present in the genome of the two isolates, while E. faecalis TA102 additionally harboured entP and bac31 genes. The phenotypic and genotypic virulence assessment studies indicated hyaluronidase (hyl) production and vancomycin resistance in E. faecalis TA102 while, none of the isolates harboured the biogenic amine genes. Conclusion: The presence of virulence genes in E. faecalis TA102 calls for careful monitoring of Enterococcus isolates for their safety parameters. PMID:29238458

  8. Hydrogen peroxide production and myo-inositol metabolism as important traits for virulence of Mycoplasma hyopneumoniae.

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    Ferrarini, M G; Mucha, S G; Parrot, D; Meiffren, G; Bachega, J F R; Comte, G; Zaha, A; Sagot, M F

    2018-04-06

    Mycoplasma hyopneumoniae is the causative agent of enzootic pneumonia. In our previous work, we reconstructed the metabolic models of this species along with two other mycoplasmas from the respiratory tract of swine: Mycoplasma hyorhinis, considered less pathogenic but which nonetheless causes disease and Mycoplasma flocculare, a commensal bacterium. We identified metabolic differences that partially explained their different levels of pathogenicity. One important trait was the production of hydrogen peroxide from the glycerol metabolism only in the pathogenic species. Another important feature was a pathway for the metabolism of myo-inositol in M. hyopneumoniae. Here, we tested these traits to understand their relation to the different levels of pathogenicity, comparing not only the species but also pathogenic and attenuated strains of M. hyopneumoniae. Regarding the myo-inositol metabolism, we show that only M. hyopneumoniae assimilated this carbohydrate and remained viable when myo-inositol was the primary energy source. Strikingly, only the two pathogenic strains of M. hyopneumoniae produced hydrogen peroxide in complex medium. We also show that this production was dependent on the presence of glycerol. Although further functional tests are needed, we present in this work two interesting metabolic traits of M. hyopneumoniae that might be directly related to its enhanced virulence. This article is protected by copyright. All rights reserved. © 2018 John Wiley & Sons Ltd.

  9. Type IV pili in Francisella – A virulence trait in an intracellular pathogen

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    Emelie eNäslund Salomonsson

    2011-02-01

    Full Text Available Francisella tularensis is a highly virulent intracellular human pathogen that is capable of rapid proliferation in the infected host. Mutants affected in intracellular survival and growth are highly attenuated which highlights the importance of the intracellular phase of the infection. Genomic analysis has revealed that Francisella encodes all genes required for expression of functional type IV pili (Tfp, and in this focused review we summarise recent findings regarding this system in the pathogenesis of tularemia. Tfp are dynamic adhesive structures that have been identified as major virulence determinants in several human pathogens, but it is not obvious what role these structures could have in an intracellular pathogen like Francisella. In the human pathogenic strains, genes required for secretion and assembly of Tfp and one pilin, PilA, have shown to be required for full virulence. Importantly, specific genetic differences have been identified between the different Francisella subspecies where in the most pathogenic type A variants all genes are intact while several Tfp genes are pseudogenes in the less pathogenic type B strains. This suggests that there has been a selection for expression of Tfp with different properties in the different subspecies. There is also a possibility that the genetic differences reflect adaption to different environmental niches of the subspecies and plays a role in transmission of tularemia. This is also in line with recent findings where Tfp pilins are found to be glycosylated which could reflect a role for Tfp in the environment to promote survival and transmission. We are still far from understanding the role of Tfp in virulence and transmission of tularemia, but with the genomic information and genetic tools available we are in a good position to address these issues in the future.

  10. Colony types and virulence traits of Legionella feeleii determined by exopolysaccharide materials.

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    Wang, Changle; Saito, Mitsumasa; Ogawa, Midori; Yoshida, Shin-Ichi

    2016-05-01

    Legionella feeleii is a Gram-negative pathogenic bacterium that causes Pontiac fever and pneumonia in humans. When L. feeleii serogroup 1 (ATCC 35072) was cultured on BCYE agar plates, two types of colonies were observed and exhibited differences in color, opacity and morphology. Since the two colony types are white rugose and brown translucent, they were termed as white rugose L. feeleii (WRLf) and brown translucent L. feeleii (BTLf), respectively. They exhibited different growth capacities in BYE broth in vitro, and it was found that WRLf could transform to BTLf. Under the electron microscope, it was observed that WRLf secreted materials which could be stained with ruthenium red, which was absent in BTLf. When U937 macrophages and HeLa cells were infected with the bacteria, WRLf manifested stronger internalization ability than BTLf. Intracellular growth in murine macrophages and Acanthamoeba cells was affected by the level of initial phagocytosis. WRLf was more resistant to human serum bactericidal action than BTLf. After being inoculated to guinea pigs, both organisms caused fever in the animals. These results suggest that ruthenium red-stained materials secreted in the surroundings may play a crucial role in determining L. feeleii colony morphology and virulence traits. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Plasticity Regulators Modulate Specific Root Traits in Discrete Nitrogen Environments

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    Gifford, Miriam L.; Banta, Joshua A.; Katari, Manpreet S.; Hulsmans, Jo; Chen, Lisa; Ristova, Daniela; Tranchina, Daniel; Purugganan, Michael D.; Coruzzi, Gloria M.; Birnbaum, Kenneth D.

    2013-01-01

    Plant development is remarkably plastic but how precisely can the plant customize its form to specific environments? When the plant adjusts its development to different environments, related traits can change in a coordinated fashion, such that two traits co-vary across many genotypes. Alternatively, traits can vary independently, such that a change in one trait has little predictive value for the change in a second trait. To characterize such “tunability” in developmental plasticity, we carried out a detailed phenotypic characterization of complex root traits among 96 accessions of the model Arabidopsis thaliana in two nitrogen environments. The results revealed a surprising level of independence in the control of traits to environment – a highly tunable form of plasticity. We mapped genetic architecture of plasticity using genome-wide association studies and further used gene expression analysis to narrow down gene candidates in mapped regions. Mutants in genes implicated by association and expression analysis showed precise defects in the predicted traits in the predicted environment, corroborating the independent control of plasticity traits. The overall results suggest that there is a pool of genetic variability in plants that controls traits in specific environments, with opportunity to tune crop plants to a given environment. PMID:24039603

  12. The Specific Character Traits of Young Entrepreneurs in Slovakia

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    Sobeková Majková Monika

    2017-06-01

    Full Text Available Worldwide scientific researches present the entrepreneurs have to declare specific characteristic traits to be successful in the business. This paper is focused on the comparison of the specific character traits between potential young entrepreneurs and other young people. The aim is to compare the three chosen character traits differences between these two focus groups by using the statistical method of Pearson's chi-square and bring the answers on the questions why some people incline to becoming the entrepreneurs more intensively than others, and what are the differences between them in relation to the character traits and their personality characteristics. The research was conducted among 1233 young people in all regions of Slovakia in 2012. The results show, that young people who plan to become an entrepreneur, are more creative, willing to face the risk, more confident in the solvation of complicated problems and difficult tasks with the opposite group of respondents.

  13. Genotypes and pathogenicity of cellulitis isolates reveal traits that modulate APEC virulence.

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    Nicolle Lima Barbieri

    Full Text Available We characterized 144 Escherichia coli isolates from severe cellulitis lesions in broiler chickens from South Brazil. Analysis of susceptibility to 15 antimicrobials revealed frequencies of resistance of less than 30% for most antimicrobials except tetracycline (70% and sulphonamides (60%. The genotyping of 34 virulence-associated genes revealed that all the isolates harbored virulence factors related to adhesion, iron acquisition and serum resistance, which are characteristic of the avian pathogenic E. coli (APEC pathotype. ColV plasmid-associated genes (cvi/cva, iroN, iss, iucD, sitD, traT, tsh were especially frequent among the isolates (from 66.6% to 89.6%. According to the Clermont method of ECOR phylogenetic typing, isolates belonged to group D (47.2%, to group A (27.8%, to group B2 (17.4% and to group B1 (7.6%; the group B2 isolates contained the highest number of virulence-associated genes. Clonal relationship analysis using the ARDRA method revealed a similarity level of 57% or higher among isolates, but no endemic clone. The virulence of the isolates was confirmed in vivo in one-day-old chicks. Most isolates (72.9% killed all infected chicks within 7 days, and 65 isolates (38.1% killed most of them within 24 hours. In order to analyze differences in virulence among the APEC isolates, we created a pathogenicity score by combining the times of death with the clinical symptoms noted. By looking for significant associations between the presence of virulence-associated genes and the pathogenicity score, we found that the presence of genes for invasins ibeA and gimB and for group II capsule KpsMTII increased virulence, while the presence of pic decreased virulence. The fact that ibeA, gimB and KpsMTII are characteristic of neonatal meningitis E. coli (NMEC suggests that genes of NMEC in APEC increase virulence of strains.

  14. Proteomic analysis of growth phase-dependent expression of Legionella pneumophila proteins which involves regulation of bacterial virulence traits.

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    Tsuyoshi Hayashi

    Full Text Available Legionella pneumophila, which is a causative pathogen of Legionnaires' disease, expresses its virulent traits in response to growth conditions. In particular, it is known to become virulent at a post-exponential phase in vitro culture. In this study, we performed a proteomic analysis of differences in expression between the exponential phase and post-exponential phase to identify candidates associated with L. pneumophila virulence using 2-Dimentional Fluorescence Difference Gel Electrophoresis (2D-DIGE combined with Matrix-Assisted Laser Desorption/Ionization-Mass Spectrometry (MALDI-TOF-MS. Of 68 identified proteins that significantly differed in expression between the two growth phases, 64 were up-regulated at a post-exponential phase. The up-regulated proteins included enzymes related to glycolysis, ketone body biogenesis and poly-3-hydroxybutyrate (PHB biogenesis, suggesting that L. pneumophila may utilize sugars and lipids as energy sources, when amino acids become scarce. Proteins related to motility (flagella components and twitching motility-associated proteins were also up-regulated, predicting that they enhance infectivity of the bacteria in host cells under certain conditions. Furthermore, 9 up-regulated proteins of unknown function were found. Two of them were identified as novel bacterial factors associated with hemolysis of sheep red blood cells (SRBCs. Another 2 were found to be translocated into macrophages via the Icm/Dot type IV secretion apparatus as effector candidates in a reporter assay with Bordetella pertussis adenylate cyclase. The study will be helpful for virulent analysis of L. pneumophila from the viewpoint of physiological or metabolic modulation dependent on growth phase.

  15. Virulence attributes and hyphal growth of C. neoformans are quantitative traits and the MATalpha allele enhances filamentation.

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    Xiaorong Lin

    2006-11-01

    Full Text Available Cryptococcus neoformans is a fungal human pathogen with a bipolar mating system. It undergoes a dimorphic transition from a unicellular yeast to hyphal filamentous growth during mating and monokaryotic fruiting. The traditional sexual cycle that leads to the production of infectious basidiospores involves cells of both alpha and a mating type. Monokaryotic fruiting is a modified form of sexual reproduction that involves cells of the same mating type, most commonly alpha, which is the predominant mating type in both the environment and clinical isolates. However, some a isolates can also undergo monokaryotic fruiting. To determine whether mating type and other genetic loci contribute to the differences in fruiting observed between alpha and a cells, we applied quantitative trait loci (QTL mapping to an inbred population of F2 progeny. We discovered that variation in hyphal length produced during fruiting is a quantitative trait resulting from the combined effects of multiple genetic loci, including the mating type (MAT locus. Importantly, the alpha allele of the MAT locus enhanced hyphal growth compared with the a allele. Other virulence traits, including melanization and growth at 39 degrees C, also are quantitative traits that share a common QTL with hyphal growth. The Mac1 transcription factor, encoded in this common QTL, regulates copper homeostasis. MAC1 allelic differences contribute to phenotypic variation, and mac1Delta mutants exhibit defects in filamentation, melanin production, and high temperature growth. Further characterization of these QTL regions will reveal additional quantitative trait genes controlling biological processes central to fungal development and pathogenicity.

  16. Mixed infections reveal virulence differences between host-specific bee pathogens.

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    Klinger, Ellen G; Vojvodic, Svjetlana; DeGrandi-Hoffman, Gloria; Welker, Dennis L; James, Rosalind R

    2015-07-01

    Dynamics of host-pathogen interactions are complex, often influencing the ecology, evolution and behavior of both the host and pathogen. In the natural world, infections with multiple pathogens are common, yet due to their complexity, interactions can be difficult to predict and study. Mathematical models help facilitate our understanding of these evolutionary processes, but empirical data are needed to test model assumptions and predictions. We used two common theoretical models regarding mixed infections (superinfection and co-infection) to determine which model assumptions best described a group of fungal pathogens closely associated with bees. We tested three fungal species, Ascosphaera apis, Ascosphaera aggregata and Ascosphaera larvis, in two bee hosts (Apis mellifera and Megachile rotundata). Bee survival was not significantly different in mixed infections vs. solo infections with the most virulent pathogen for either host, but fungal growth within the host was significantly altered by mixed infections. In the host A. mellifera, only the most virulent pathogen was present in the host post-infection (indicating superinfective properties). In M. rotundata, the most virulent pathogen co-existed with the lesser-virulent one (indicating co-infective properties). We demonstrated that the competitive outcomes of mixed infections were host-specific, indicating strong host specificity among these fungal bee pathogens. Published by Elsevier Inc.

  17. Host specific glycans are correlated with susceptibility to infection by lagoviruses, but not with their virulence.

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    Lopes, Ana M; Breiman, Adrien; Lora, Mónica; Le Moullac-Vaidye, Béatrice; Galanina, Oxana; Nyström, Kristina; Marchandeau, Stephane; Le Gall-Reculé, Ghislaine; Strive, Tanja; Neimanis, Aleksija; Bovin, Nicolai V; Ruvoën-Clouet, Nathalie; Esteves, Pedro J; Abrantes, Joana; Le Pendu, Jacques

    2017-11-29

    The rabbit hemorrhagic disease virus (RHDV) and the European brown hare syndrome virus (EBHSV) are two lagoviruses from the family Caliciviridae that cause fatal diseases in two leporid genera, Oryctolagus and Lepus , respectively. In the last few years, several examples of host jumps of lagoviruses among leporids were recorded. In addition, a new pathogenic genotype of RHDV emerged and many non-pathogenic strains of lagoviruses have been described. The molecular mechanisms behind host shifts and the emergence of virulence are unknown. Since RHDV uses glycans of the histo-blood group antigen type as attachment factors to initiate infection, we studied if glycan specificities of the new pathogenic RHDV genotype, non-pathogenic lagoviruses and EBHSV potentially play a role in determining host range and virulence of lagoviruses. We observed binding to A, B or H antigens of the histo-blood group family for all strains known to primarily infect European rabbits ( Oryctolagus cuniculus ), that have recently been classified as GI strains. Yet, we could not explain the emergence of virulence since similar glycan specificities were found between several pathogenic and non-pathogenic strains. By contrast, EBHSV, recently classified as GII.1, bound to terminal β-linked N-acetylglucosamine residues of O-glycans. Expression of these attachment factors in the upper respiratory and digestive tracts in three lagomorph species ( Oryctolagus cuniculus, Lepus europaeus and Sylvilagus floridanus ) showed species-specific patterns regarding the susceptibility to infection by these viruses, indicating that species-specific glycan expression is likely a major contributor to lagoviruses host specificity and range. IMPORTANCE Lagoviruses constitute a genus of the Caliciviridae family, comprising highly pathogenic viruses, RHDV and EBHSV, which infect rabbits and hares, respectively. Recently, non-pathogenic strains were discovered and new pathogenic strains have emerged. In addition, host

  18. Additive Effects of Quorum Sensing Anti-Activators on Pseudomonas aeruginosa Virulence Traits and Transcriptome

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    Kyle L. Asfahl

    2018-01-01

    Full Text Available In the opportunistic pathogen Pseudomonas aeruginosa, quorum sensing (QS via acyl-homoserine lactone (AHL signals coordinates virulence gene expression. AHL signals must reach a critical threshold before enough is bound by cognate regulators LasR and RhlR to drive transcription of target genes. In addition, three anti-activator proteins, QteE, QscR, and QslA, sequester QS regulators to increase the threshold for induction and delay expression of QS target genes. It remains unclear how multiple anti-activators work together to achieve the quorum threshold. Here, we employed a combination of mutational, kinetic, phenotypic, and transcriptomic analysis to examine regulatory effects and interactions of the three distinct anti-activators. We observed combinatorial, additive effects on QS gene expression. As measured by reporter gene fusion, individual deletion of each anti-activator gene increased lasB expression and QS-controlled virulence factor production. Deletion of qslA in combination with the deletion of any other anti-activator gene resulted in the greatest increase and earliest activation of lasB gene expression. Western analysis revealed that relative increases in soluble LasR in anti-activator mutants correlate with increased lasB expression and QS-controlled virulence factor production. RNA-seq of the previously uncharacterized QslA and QteE regulons revealed overlapping, yet distinct groups of differentially expressed genes. Simultaneous inactivation of qteE and qslA had the largest effect on gene expression with 999 genes induced and 798 genes repressed in the double mutant vs. wild-type. We found that LasR and RhlR-activated QS genes formed a subset of the genes induced in the qteE, qslA, and double mutant. The activation of almost all of these QS genes was advanced from stationary phase to log phase in the qteE qslA double mutant. Taken together, our results identify additive effects of anti-activation on QS gene expression, likely

  19. Porphyromonas gingivalis Uses Specific Domain Rearrangements and Allelic Exchange to Generate Diversity in Surface Virulence Factors.

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    Dashper, Stuart G; Mitchell, Helen L; Seers, Christine A; Gladman, Simon L; Seemann, Torsten; Bulach, Dieter M; Chandry, P Scott; Cross, Keith J; Cleal, Steven M; Reynolds, Eric C

    2017-01-01

    Porphyromonas gingivalis is a keystone pathogen of chronic periodontitis. The virulence of P. gingivalis is reported to be strain related and there are currently a number of strain typing schemes based on variation in capsular polysaccharide, the major and minor fimbriae and adhesin domains of Lys-gingipain (Kgp), amongst other surface proteins. P. gingivalis can exchange chromosomal DNA between strains by natural competence and conjugation. The aim of this study was to determine the genetic variability of P. gingivalis strains sourced from international locations over a 25-year period and to determine if variability in surface virulence factors has a phylogenetic basis. Whole genome sequencing was performed on 13 strains and comparison made to 10 previously sequenced strains. A single nucleotide polymorphism-based phylogenetic analysis demonstrated a shallow tri-lobed phylogeny. There was a high level of reticulation in the phylogenetic network, demonstrating extensive horizontal gene transfer between the strains. Two highly conserved variants of the catalytic domain of the major virulence factor the Kgp proteinase (Kgp cat I and Kgp cat II) were found. There were three variants of the fourth Kgp C-terminal cleaved adhesin domain. Specific variants of the cell surface proteins FimA, FimCDE, MfaI, RagAB, Tpr, and PrtT were also identified. The occurrence of all these variants in the P. gingivalis strains formed a mosaic that was not related to the SNP-based phylogeny. In conclusion P. gingivalis uses domain rearrangements and genetic exchange to generate diversity in specific surface virulence factors.

  20. Niche-Specific Requirement for Hyphal Wall protein 1 in Virulence of Candida albicans

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    Staab, Janet F.; Datta, Kausik; Rhee, Peter

    2013-01-01

    Specialized Candida albicans cell surface proteins called adhesins mediate binding of the fungus to host cells. The mammalian transglutaminase (TG) substrate and adhesin, Hyphal wall protein 1 (Hwp1), is expressed on the hyphal form of C. albicans where it mediates fungal adhesion to epithelial cells. Hwp1 is also required for biofilm formation and mating thus the protein functions in both fungal-host and self-interactions. Hwp1 is required for full virulence of C. albicans in murine models of disseminated candidiasis and of esophageal candidiasis. Previous studies correlated TG activity on the surface of oral epithelial cells, produced by epithelial TG (TG1), with tight binding of C. albicans via Hwp1 to the host cell surfaces. However, the contribution of other Tgs, specifically tissue TG (TG2), to disseminated candidiasis mediated by Hwp1 was not known. A newly created hwp1 null strain in the wild type SC5314 background was as virulent as the parental strain in C57BL/6 mice, and virulence was retained in C57BL/6 mice deleted for Tgm2 (TG2). Further, the hwp1 null strains displayed modestly reduced virulence in BALB/c mice as did strain DD27-U1, an independently created hwp1Δ/Δ in CAI4 corrected for its ura3Δ defect at the URA3 locus. Hwp1 was still needed to produce wild type biofilms, and persist on murine tongues in an oral model of oropharyngeal candidiasis consistent with previous studies by us and others. Finally, lack of Hwp1 affected the translocation of C. albicans from the mouse intestine into the bloodstream of mice. Together, Hwp1 appears to have a minor role in disseminated candidiasis, independent of tissue TG, but a key function in host- and self-association to the surface of oral mucosa. PMID:24260489

  1. VRprofile: gene-cluster-detection-based profiling of virulence and antibiotic resistance traits encoded within genome sequences of pathogenic bacteria.

    Science.gov (United States)

    Li, Jun; Tai, Cui; Deng, Zixin; Zhong, Weihong; He, Yongqun; Ou, Hong-Yu

    2017-01-10

    VRprofile is a Web server that facilitates rapid investigation of virulence and antibiotic resistance genes, as well as extends these trait transfer-related genetic contexts, in newly sequenced pathogenic bacterial genomes. The used backend database MobilomeDB was firstly built on sets of known gene cluster loci of bacterial type III/IV/VI/VII secretion systems and mobile genetic elements, including integrative and conjugative elements, prophages, class I integrons, IS elements and pathogenicity/antibiotic resistance islands. VRprofile is thus able to co-localize the homologs of these conserved gene clusters using HMMer or BLASTp searches. With the integration of the homologous gene cluster search module with a sequence composition module, VRprofile has exhibited better performance for island-like region predictions than the other widely used methods. In addition, VRprofile also provides an integrated Web interface for aligning and visualizing identified gene clusters with MobilomeDB-archived gene clusters, or a variety set of bacterial genomes. VRprofile might contribute to meet the increasing demands of re-annotations of bacterial variable regions, and aid in the real-time definitions of disease-relevant gene clusters in pathogenic bacteria of interest. VRprofile is freely available at http://bioinfo-mml.sjtu.edu.cn/VRprofile. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Diverse protist grazers select for virulence-related traits in Legionella

    Science.gov (United States)

    Amaro, Francisco; Wang, Wen; Gilbert, Jack A; Roger Anderson, O; Shuman, Howard A

    2015-01-01

    It is generally accepted that selection for resistance to grazing by protists has contributed to the evolution of Legionella pneumophila as a pathogen. Grazing resistance is becoming more generally recognized as having an important role in the ecology and evolution of bacterial pathogenesis. However, selection for grazing resistance presupposes the existence of protist grazers that provide the selective pressure. To determine whether there are protists that graze on pathogenic Legionella species, we investigated the existence of such organisms in a variety of environmental samples. We isolated and characterized diverse protists that graze on L. pneumophila and determined the effects of adding L. pneumophila on the protist community structures in microcosms made from these environmental samples. Several unrelated organisms were able to graze efficiently on L. pneumophila. The community structures of all samples were markedly altered by the addition of L. pneumophila. Surprisingly, some of the Legionella grazers were closely related to species that are known hosts for L. pneumophila, indicating the presence of unknown specificity determinants for this interaction. These results provide the first direct support for the hypothesis that protist grazers exert selective pressure on Legionella to acquire and retain adaptations that contribute to survival, and that these properties are relevant to the ability of the bacteria to cause disease in people. We also report a novel mechanism of killing of amoebae by one Legionella species that requires an intact Type IV secretion system but does not involve intracellular replication. We refer to this phenomenon as ‘food poisoning'. PMID:25575308

  3. Specificity, contexts, and reference groups matter when assessing autistic traits

    OpenAIRE

    Gernsbacher, Morton Ann; Stevenson, Jennifer L.; Dern, Sebastian

    2017-01-01

    Many of the personality and behavioral traits (e.g., social imperviousness, directness in conversation, lack of imagination, affinity for solitude, difficulty displaying emotions) that are known to be sensitive to context (with whom?) and reference group (according to whom?) also appear in questionnaire-based assessments of autistic traits. Therefore, two experiments investigated the effects of specifying contexts and reference groups when assessing autistic traits in autistic and non-autisti...

  4. Specificity, contexts, and reference groups matter when assessing autistic traits

    Science.gov (United States)

    Stevenson, Jennifer L.; Dern, Sebastian

    2017-01-01

    Many of the personality and behavioral traits (e.g., social imperviousness, directness in conversation, lack of imagination, affinity for solitude, difficulty displaying emotions) that are known to be sensitive to context (with whom?) and reference group (according to whom?) also appear in questionnaire-based assessments of autistic traits. Therefore, two experiments investigated the effects of specifying contexts and reference groups when assessing autistic traits in autistic and non-autistic participants. Experiment 1 (124 autistic and 124 non-autistic participants) demonstrated that context matters when assessing autistic traits (F(1,244) = 267.5, p autistic people” or “I like being around autistic people”), both autistic and non-autistic participants self-reported having more autistic traits; when the context was specified as the participants’ in-group, participants reported having fewer autistic traits. Experiment 2 (82 autistic and 82 non-autistic participants) demonstrated that reference group matters when assessing autistic traits (F(2,160) = 94.38, p autistic people, I have unusual eye contact”), autistic participants reported having more autistic traits; when the reference group was their in-group, autistic participants reported having fewer autistic traits. Non-autistic participants appeared insensitive to reference group on the Social Responsiveness Scale. Exploratory analyses suggested that when neither the context nor the reference group is specified (for assessing autistic traits on the Autism-Spectrum Quotient), both autistic and non-autistic participants use the majority (“non-autistic people”) as the implied context and reference group. PMID:28192464

  5. Specific selection for virulent urinary tract infectious Escherichia coli strains during catheter-associated biofilm formation

    DEFF Research Database (Denmark)

    Ferrieres, Lionel; Hancock, Viktoria; Klemm, Per

    2007-01-01

    microorganisms can attach. Urinary tract infectious (UTI) Escherichia coli range in pathogenicity and the damage they cause - from benign asymptomatic bacteriuria (ABU) strains, which inflict no or few problems to the host, to uropathogenic E. coli (UPEC) strains, which are virulent and often cause severe...... for and promote biofilm formation of the most virulent group of UTI E. coli strains, hardly a desirable situation for the catheterized patient....

  6. Acinetobacter baumannii Virulence Traits: A Comparative Study of a Novel Sequence Type with Other Italian Endemic International Clones

    Directory of Open Access Journals (Sweden)

    Cecilia Ambrosi

    2017-10-01

    Full Text Available Carbapenem-resistant Acinetobacter baumannii (CRAb have emerged in recent decades as major causes of nosocomial infections. Resistance is mainly due to overexpression of intrinsic and/or acquired carbapenemases, especially oxacillinases (OXA. In Italy, although the sequence type (ST 2 and the ST78 are the most frequently detected, we recently reported ST632, a single locus variant of ST2. Therefore, this study was aimed at unraveling common bacterial surface virulence factors involved in pathogenesis and antibiotic resistance in representative CRAb of these ST genotypes. Outer membrane protein (OMP composition together with motility, biofilm formation, in vitro adherence to, invasion of, and survival within pneumocytes were analyzed. Differently from the carbapenem-susceptible reference strain ATCC 17978, either overexpressed OXA-51 or both OXA-23 and OXA-51 co-purified with OMPs in CRAb. This tight association ensures their maximal concentration on the inner surface of the outer membrane to provide the best protection against carbapenems. These findings led us to propose for the first time a common behavior of OXA enzymes in CRAb. Despite the presence of both OmpA and phosphorylcholine-porinD and the ability of all the strains to adhere to cells, invasion, and survival within pneumocytes was shown only by ST2 and ST78 isolates, sharing the highest number of identified OMPs. Conversely, notwithstanding genetic and OMPs similarities with ST2, ST632 was unable to invade and survive within epithelial cells. Overall, our study shows that different STs share a specific OMP composition, also shaped by overexpressed OXA, that is needed for invasiveness and survival of CRAb.

  7. Acinetobacter baumannii Virulence Traits: A Comparative Study of a Novel Sequence Type with Other Italian Endemic International Clones.

    Science.gov (United States)

    Ambrosi, Cecilia; Scribano, Daniela; Aleandri, Marta; Zagaglia, Carlo; Di Francesco, Laura; Putignani, Lorenza; Palamara, Anna Teresa

    2017-01-01

    Carbapenem-resistant Acinetobacter baumannii (CRAb) have emerged in recent decades as major causes of nosocomial infections. Resistance is mainly due to overexpression of intrinsic and/or acquired carbapenemases, especially oxacillinases (OXA). In Italy, although the sequence type (ST) 2 and the ST78 are the most frequently detected, we recently reported ST632, a single locus variant of ST2. Therefore, this study was aimed at unraveling common bacterial surface virulence factors involved in pathogenesis and antibiotic resistance in representative CRAb of these ST genotypes. Outer membrane protein (OMP) composition together with motility, biofilm formation, in vitro adherence to, invasion of, and survival within pneumocytes were analyzed. Differently from the carbapenem-susceptible reference strain ATCC 17978, either overexpressed OXA-51 or both OXA-23 and OXA-51 co-purified with OMPs in CRAb. This tight association ensures their maximal concentration on the inner surface of the outer membrane to provide the best protection against carbapenems. These findings led us to propose for the first time a common behavior of OXA enzymes in CRAb. Despite the presence of both OmpA and phosphorylcholine-porinD and the ability of all the strains to adhere to cells, invasion, and survival within pneumocytes was shown only by ST2 and ST78 isolates, sharing the highest number of identified OMPs. Conversely, notwithstanding genetic and OMPs similarities with ST2, ST632 was unable to invade and survive within epithelial cells. Overall, our study shows that different STs share a specific OMP composition, also shaped by overexpressed OXA, that is needed for invasiveness and survival of CRAb.

  8. Use of genetic data to infer population-specific ecological and phenotypic traits from mixed aggregations.

    Directory of Open Access Journals (Sweden)

    Paul Moran

    Full Text Available Many applications in ecological genetics involve sampling individuals from a mixture of multiple biological populations and subsequently associating those individuals with the populations from which they arose. Analytical methods that assign individuals to their putative population of origin have utility in both basic and applied research, providing information about population-specific life history and habitat use, ecotoxins, pathogen and parasite loads, and many other non-genetic ecological, or phenotypic traits. Although the question is initially directed at the origin of individuals, in most cases the ultimate desire is to investigate the distribution of some trait among populations. Current practice is to assign individuals to a population of origin and study properties of the trait among individuals within population strata as if they constituted independent samples. It seemed that approach might bias population-specific trait inference. In this study we made trait inferences directly through modeling, bypassing individual assignment. We extended a Bayesian model for population mixture analysis to incorporate parameters for the phenotypic trait and compared its performance to that of individual assignment with a minimum probability threshold for assignment. The Bayesian mixture model outperformed individual assignment under some trait inference conditions. However, by discarding individuals whose origins are most uncertain, the individual assignment method provided a less complex analytical technique whose performance may be adequate for some common trait inference problems. Our results provide specific guidance for method selection under various genetic relationships among populations with different trait distributions.

  9. Use of genetic data to infer population-specific ecological and phenotypic traits from mixed aggregations

    Science.gov (United States)

    Moran, Paul; Bromaghin, Jeffrey F.; Masuda, Michele

    2014-01-01

    Many applications in ecological genetics involve sampling individuals from a mixture of multiple biological populations and subsequently associating those individuals with the populations from which they arose. Analytical methods that assign individuals to their putative population of origin have utility in both basic and applied research, providing information about population-specific life history and habitat use, ecotoxins, pathogen and parasite loads, and many other non-genetic ecological, or phenotypic traits. Although the question is initially directed at the origin of individuals, in most cases the ultimate desire is to investigate the distribution of some trait among populations. Current practice is to assign individuals to a population of origin and study properties of the trait among individuals within population strata as if they constituted independent samples. It seemed that approach might bias population-specific trait inference. In this study we made trait inferences directly through modeling, bypassing individual assignment. We extended a Bayesian model for population mixture analysis to incorporate parameters for the phenotypic trait and compared its performance to that of individual assignment with a minimum probability threshold for assignment. The Bayesian mixture model outperformed individual assignment under some trait inference conditions. However, by discarding individuals whose origins are most uncertain, the individual assignment method provided a less complex analytical technique whose performance may be adequate for some common trait inference problems. Our results provide specific guidance for method selection under various genetic relationships among populations with different trait distributions.

  10. An Aphid Effector Targets Trafficking Protein VPS52 in a Host-Specific Manner to Promote Virulence1[OPEN

    Science.gov (United States)

    2017-01-01

    Plant- and animal-feeding insects secrete saliva inside their hosts, containing effectors, which may promote nutrient release and suppress immunity. Although for plant pathogenic microbes it is well established that effectors target host proteins to modulate host cell processes and promote disease, the host cell targets of herbivorous insects remain elusive. Here, we show that the existing plant pathogenic microbe effector paradigm can be extended to herbivorous insects in that effector-target interactions inside host cells modify critical host processes to promote plant susceptibility. We showed that the effector Mp1 from Myzus persicae associates with the host Vacuolar Protein Sorting Associated Protein52 (VPS52). Using natural variants, we provide a strong link between effector virulence activity and association with VPS52, and show that the association is highly specific to M. persicae-host interactions. Also, coexpression of Mp1, but not Mp1-like variants, specifically with host VPS52s resulted in effector relocalization to vesicle-like structures that associate with prevacuolar compartments. We show that high VPS52 levels negatively impact virulence, and that aphids are able to reduce VPS52 levels during infestation, indicating that VPS52 is an important virulence target. Our work is an important step forward in understanding, at the molecular level, how a major agricultural pest promotes susceptibility during infestation of crop plants. We give evidence that an herbivorous insect employs effectors that interact with host proteins as part of an effective virulence strategy, and that these effectors likely function in a species-specific manner. PMID:28100451

  11. An Aphid Effector Targets Trafficking Protein VPS52 in a Host-Specific Manner to Promote Virulence.

    Science.gov (United States)

    Rodriguez, Patricia A; Escudero-Martinez, Carmen; Bos, Jorunn I B

    2017-03-01

    Plant- and animal-feeding insects secrete saliva inside their hosts, containing effectors, which may promote nutrient release and suppress immunity. Although for plant pathogenic microbes it is well established that effectors target host proteins to modulate host cell processes and promote disease, the host cell targets of herbivorous insects remain elusive. Here, we show that the existing plant pathogenic microbe effector paradigm can be extended to herbivorous insects in that effector-target interactions inside host cells modify critical host processes to promote plant susceptibility. We showed that the effector Mp1 from Myzus persicae associates with the host Vacuolar Protein Sorting Associated Protein52 (VPS52). Using natural variants, we provide a strong link between effector virulence activity and association with VPS52, and show that the association is highly specific to M persicae -host interactions. Also, coexpression of Mp1, but not Mp1-like variants, specifically with host VPS52s resulted in effector relocalization to vesicle-like structures that associate with prevacuolar compartments. We show that high VPS52 levels negatively impact virulence, and that aphids are able to reduce VPS52 levels during infestation, indicating that VPS52 is an important virulence target. Our work is an important step forward in understanding, at the molecular level, how a major agricultural pest promotes susceptibility during infestation of crop plants. We give evidence that an herbivorous insect employs effectors that interact with host proteins as part of an effective virulence strategy, and that these effectors likely function in a species-specific manner. © 2017 American Society of Plant Biologists. All Rights Reserved.

  12. 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.

  13. Trait-specific processes of convergence and conservatism shape ecomorphological evolution in ground-dwelling squirrels.

    Science.gov (United States)

    McLean, Bryan S; Helgen, Kristofer M; Goodwin, H Thomas; Cook, Joseph A

    2018-03-01

    Our understanding of mechanisms operating over deep timescales to shape phenotypic diversity often hinges on linking variation in one or few trait(s) to specific evolutionary processes. When distinct processes are capable of similar phenotypic signatures, however, identifying these drivers is difficult. We explored ecomorphological evolution across a radiation of ground-dwelling squirrels whose history includes convergence and constraint, two processes that can yield similar signatures of standing phenotypic diversity. Using four ecologically relevant trait datasets (body size, cranial, mandibular, and molariform tooth shape), we compared and contrasted variation, covariation, and disparity patterns in a new phylogenetic framework. Strong correlations existed between body size and two skull traits (allometry) and among skull traits themselves (integration). Inferred evolutionary modes were also concordant across traits (Ornstein-Uhlenbeck with two adaptive regimes). However, despite these broad similarities, we found divergent dynamics on the macroevolutionary landscape, with phenotypic disparity being differentially shaped by convergence and conservatism. Such among-trait heterogeneity in process (but not always pattern) reiterates the mosaic nature of morphological evolution, and suggests ground squirrel evolution is poorly captured by single process descriptors. Our results also highlight how use of single traits can bias macroevolutionary inference, affirming the importance of broader trait-bases in understanding phenotypic evolutionary dynamics. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

  14. Novel Burkholderia mallei Virulence Factors Linked to Specific Host-Pathogen Protein Interactions

    Science.gov (United States)

    2013-06-23

    equine hosts. Thus, the genes retained in B. mallei share a high sequence similarity to genes common to B. pseudomallei (3), and many virulence...oppor- tunistic infections in mammalian hosts. Even for the equine - adapted and, thus, more genetically constrained, B. mallei pathogen, we cannot...BioDrugs: Clin. Immunotherapeut., Biopharmaceut. Gene Therapy 17, 413–424 88. Anderson, D. M., and Frank, D. W. (2012) Five mechanisms of manipula

  15. Breeding of maize types with specific traits at the Maize Research Institute, Zemun Polje

    OpenAIRE

    Pajić Zorica

    2007-01-01

    Maize is primarily grown as an energy crop, but the use of different specific versions, such as high-oil maize, high-lysine maize, waxy maize, white-seeded maize, popping maize and sweet maize, is quite extensive. Speciality maize, due to its traits and genetic control of these traits, requires a particular attention in handling breeding material during the processes of breeding. It is especially related to prevention of uncontrolled pollination. In order to provide successful selection for a...

  16. Characterization of Foodborne Strains of Staphylococcus aureus by Shotgun Proteomics: Functional Networks, Virulence Factors and Species-Specific Peptide Biomarkers

    Science.gov (United States)

    Carrera, Mónica; Böhme, Karola; Gallardo, José M.; Barros-Velázquez, Jorge; Cañas, Benito; Calo-Mata, Pilar

    2017-01-01

    In the present work, we applied a shotgun proteomics approach for the fast and easy characterization of 20 different foodborne strains of Staphylococcus aureus (S. aureus), one of the most recognized foodborne pathogenic bacteria. A total of 644 non-redundant proteins were identified and analyzed via an easy and rapid protein sample preparation procedure. The results allowed the differentiation of several proteome datasets from the different strains (common, accessory, and unique datasets), which were used to determine relevant functional pathways and differentiate the strains into different Euclidean hierarchical clusters. Moreover, a predicted protein-protein interaction network of the foodborne S. aureus strains was created. The whole confidence network contains 77 nodes and 769 interactions. Most of the identified proteins were surface-associated proteins that were related to pathways and networks of energy, lipid metabolism and virulence. Twenty-seven virulence factors were identified, and most of them corresponded to autolysins, N-acetylmuramoyl-L-alanine amidases, phenol-soluble modulins, extracellular fibrinogen-binding proteins and virulence factor EsxA. Potential species-specific peptide biomarkers were screened. Twenty-one species-specific peptide biomarkers, belonging to eight different proteins (nickel-ABC transporter, N-acetylmuramoyl-L-alanine amidase, autolysin, clumping factor A, gram-positive signal peptide YSIRK, cysteine protease/staphopain, transcriptional regulator MarR, and transcriptional regulator Sar-A), were proposed to identify S. aureus. These results constitute the first major dataset of peptides and proteins of foodborne S. aureus strains. This repository may be useful for further studies, for the development of new therapeutic treatments for S. aureus food intoxications and for microbial source-tracking in foodstuffs. PMID:29312172

  17. Can Neglected Tropical Diseases Compromise Human Wellbeing in Sex-, Age-, and Trait-Specific Ways?

    Directory of Open Access Journals (Sweden)

    David C Geary

    2016-04-01

    Full Text Available Traits that facilitate competition for reproductive resources or that influence mate choice have evolved to signal resilience to infectious disease and other stressors. As a result, the dynamics of competition and choice can, in theory, be used to generate predictions about sex-, age-, and trait-specific vulnerabilities for any sexually reproducing species, including humans. These dynamics and associated vulnerabilities are reviewed for nonhuman species, focusing on traits that are compromised by exposure to parasites. Using the same approach, sex-, age-, and trait-specific vulnerabilities to parasitic disease are illustrated for children's and adolescent's physical growth and fitness. Suggestions are then provided for widening the assessment of human vulnerabilities to include age-appropriate measures of behavioral (e.g., children's play and cognitive (e.g., language fluency traits. These are traits that are likely to be compromised by infection in age- and sex-specific ways. Inclusion of these types of measures in studies of neglected tropic diseases has the potential to provide a more nuanced understanding of how these diseases undermine human wellbeing and may provide a useful means to study the efficacy of associated treatments.

  18. Heritability and tissue specificity of expression quantitative trait loci

    Czech Academy of Sciences Publication Activity Database

    Petretto, E.; Mangion, J.; Dickens, N. J.; Cook, S.A.; Kumaran, M. K.; Lu, H.; Fischer, J.; Maatz, H.; Křen, Vladimír; Pravenec, Michal; Hubner, N.; Aitman, T. J.

    2006-01-01

    Roč. 2, č. 10 (2006), s. 1625-1633 ISSN 1553-7390 R&D Projects: GA MŠk(CZ) 1M0520; GA ČR(CZ) GA301/06/0028; GA ČR(CZ) GA301/04/0390 Grant - others:HHMI(US) 55005624 Institutional research plan: CEZ:AV0Z50110509 Keywords : expression QTL * heritability * tissue specificity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.671, year: 2006

  19. Evolution of Sex Differences in Trait- and Age-Specific Vulnerabilities.

    Science.gov (United States)

    Geary, David C

    2016-11-01

    Traits that facilitate competition for reproductive resources or that influence mate choice generally have a heightened sensitivity to stressors. They have evolved to signal resilience to infectious disease and nutritional and social stressors, and they are compromised by exposure to man-made toxins. Although these traits can differ from one species or sex to the next, an understanding of the dynamics of competition and choice can in theory be used to generate a priori predictions about sex-, age-, and trait-specific vulnerabilities for any sexually reproducing species. I provide a review of these dynamics and illustrate associated vulnerabilities in nonhuman species. The age- and sex-specific vulnerability of such traits is then illustrated for stressor-related disruptions of boys' and girls' physical growth and play behavior, as well as for aspects of boys' and girls' and men's and women's personality, language, and spatial abilities. There is much that remains to be determined, but enough is now known to reframe trait sensitivity in ways that will allow scientists and practitioners to better identify and understand vulnerable human traits, and eventually ameliorate or prevent their expression. © The Author(s) 2016.

  20. Integrating Iris and Signature Traits for Personal Authentication Using User-SpecificWeighting

    Directory of Open Access Journals (Sweden)

    Serestina Viriri

    2012-03-01

    Full Text Available Biometric systems based on uni-modal traits are characterized by noisy sensor data, restricted degrees of freedom, non-universality and are susceptible to spoof attacks. Multi-modal biometric systems seek to alleviate some of these drawbacks by providing multiple evidences of the same identity. In this paper, a user-score-based weighting technique for integrating the iris and signature traits is presented. This user-specific weighting technique has proved to be an efficient and effective fusion scheme which increases the authentication accuracy rate of multi-modal biometric systems. The weights are used to indicate the importance of matching scores output by each biometrics trait. The experimental results show that our biometric system based on the integration of iris and signature traits achieve a false rejection rate (FRR of 0.08% and a false acceptance rate (FAR of 0.01%.

  1. Comparative Genomic Analyses of Multiple Pseudomonas Strains Infecting Corylus avellana Trees Reveal the Occurrence of Two Genetic Clusters with Both Common and Distinctive Virulence and Fitness Traits

    Science.gov (United States)

    Marcelletti, Simone; Scortichini, Marco

    2015-01-01

    The European hazelnut (Corylus avellana) is threatened in Europe by several pseudomonads which cause symptoms ranging from twig dieback to tree death. A comparison of the draft genomes of nine Pseudomonas strains isolated from symptomatic C. avellana trees was performed to identify common and distinctive genomic traits. The thorough assessment of genetic relationships among the strains revealed two clearly distinct clusters: P. avellanae and P. syringae. The latter including the pathovars avellanae, coryli and syringae. Between these two clusters, no recombination event was found. A genomic island of approximately 20 kb, containing the hrp/hrc type III secretion system gene cluster, was found to be present without any genomic difference in all nine pseudomonads. The type III secretion system effector repertoires were remarkably different in the two groups, with P. avellanae showing a higher number of effectors. Homologue genes of the antimetabolite mangotoxin and ice nucleation activity clusters were found solely in all P. syringae pathovar strains, whereas the siderophore yersiniabactin was only present in P. avellanae. All nine strains have genes coding for pectic enzymes and sucrose metabolism. By contrast, they do not have genes coding for indolacetic acid and anti-insect toxin. Collectively, this study reveals that genomically different Pseudomonas can converge on the same host plant by suppressing the host defence mechanisms with the use of different virulence weapons. The integration into their genomes of a horizontally acquired genomic island could play a fundamental role in their evolution, perhaps giving them the ability to exploit new ecological niches. PMID:26147218

  2. Accounting for standard errors of vision-specific latent trait in regression models.

    Science.gov (United States)

    Wong, Wan Ling; Li, Xiang; Li, Jialiang; Wong, Tien Yin; Cheng, Ching-Yu; Lamoureux, Ecosse L

    2014-07-11

    To demonstrate the effectiveness of Hierarchical Bayesian (HB) approach in a modeling framework for association effects that accounts for SEs of vision-specific latent traits assessed using Rasch analysis. A systematic literature review was conducted in four major ophthalmic journals to evaluate Rasch analysis performed on vision-specific instruments. The HB approach was used to synthesize the Rasch model and multiple linear regression model for the assessment of the association effects related to vision-specific latent traits. The effectiveness of this novel HB one-stage "joint-analysis" approach allows all model parameters to be estimated simultaneously and was compared with the frequently used two-stage "separate-analysis" approach in our simulation study (Rasch analysis followed by traditional statistical analyses without adjustment for SE of latent trait). Sixty-six reviewed articles performed evaluation and validation of vision-specific instruments using Rasch analysis, and 86.4% (n = 57) performed further statistical analyses on the Rasch-scaled data using traditional statistical methods; none took into consideration SEs of the estimated Rasch-scaled scores. The two models on real data differed for effect size estimations and the identification of "independent risk factors." Simulation results showed that our proposed HB one-stage "joint-analysis" approach produces greater accuracy (average of 5-fold decrease in bias) with comparable power and precision in estimation of associations when compared with the frequently used two-stage "separate-analysis" procedure despite accounting for greater uncertainty due to the latent trait. Patient-reported data, using Rasch analysis techniques, do not take into account the SE of latent trait in association analyses. The HB one-stage "joint-analysis" is a better approach, producing accurate effect size estimations and information about the independent association of exposure variables with vision-specific latent traits

  3. Using Bioinformatics to Develop and Test Hypotheses: E. coli-Specific Virulence Determinants

    Directory of Open Access Journals (Sweden)

    Joanna R. Klein

    2012-09-01

    Full Text Available Bioinformatics, the use of computer resources to understand biological information, is an important tool in research, and can be easily integrated into the curriculum of undergraduate courses. Such an example is provided in this series of four activities that introduces students to the field of bioinformatics as they design PCR based tests for pathogenic E. coli strains. A variety of computer tools are used including BLAST searches at NCBI, bacterial genome searches at the Integrated Microbial Genomes (IMG database, protein analysis at Pfam and literature research at PubMed. In the process, students also learn about virulence factors, enzyme function and horizontal gene transfer. Some or all of the four activities can be incorporated into microbiology or general biology courses taken by students at a variety of levels, ranging from high school through college. The activities build on one another as they teach and reinforce knowledge and skills, promote critical thinking, and provide for student collaboration and presentation. The computer-based activities can be done either in class or outside of class, thus are appropriate for inclusion in online or blended learning formats. Assessment data showed that students learned general microbiology concepts related to pathogenesis and enzyme function, gained skills in using tools of bioinformatics and molecular biology, and successfully developed and tested a scientific hypothesis.

  4. Virulence of luminescent and non-luminescent isogenic vibrios towards gnotobiotic Artemia franciscana larvae and specific pathogen-free Litopenaeus vannamei shrimp.

    Science.gov (United States)

    Phuoc, L H; Defoirdt, T; Sorgeloos, P; Bossier, P

    2009-04-01

    This study was conducted to test the virulence of luminescent (L) and non-luminescent (NL) isogenic strains of Vibrio campbellii LMG21363, Vibrio harveyi BB120 (wild type) and quorum-sensing mutant strains derived from the wild type such as Vibrio harveyi BB152, BB170, MM30 and BB886. The NL strains could be obtained by culturing rifampicin-resistant luminescent strains in the dark under static condition. The virulence of the L and NL strains was tested in gnotobiotic Artemia franciscana larvae challenged with 10(4) CFU ml(-1) of bacteria. All luminescent isogenic tested strains showed higher virulence compared to the NL strains. The virulence of L and NL V. campbellii and V. harveyi BB120 was also tested in specific pathogen-free juvenile shrimp upon intramuscular injection with 10(6) CFU of bacteria. In contrast with Artemia, there was no significant difference in mortality between the groups challenged with L and NL strains (P > 0.05). The non-luminescent strains were not able to revert back to the luminescent state and quorum sensing did not influence this phenotypic shift. Luminescent Vibrio strains can switch to a non-luminescent state by culturing them in static conditions. The NL strains become less virulent as verified in Artemia. The luminescent state of Vibrio cells in a culture needs to be verified in order to assure maintenance of virulence.

  5. Breeding of maize types with specific traits at the Maize Research Institute, Zemun Polje

    Directory of Open Access Journals (Sweden)

    Pajić Zorica

    2007-01-01

    Full Text Available Maize is primarily grown as an energy crop, but the use of different specific versions, such as high-oil maize, high-lysine maize, waxy maize, white-seeded maize, popping maize and sweet maize, is quite extensive. Speciality maize, due to its traits and genetic control of these traits, requires a particular attention in handling breeding material during the processes of breeding. It is especially related to prevention of uncontrolled pollination. In order to provide successful selection for a certain trait, the following specific procedures in evaluation of the trait are necessary: the estimation of a popping volume and flake quality in popping maize; the determination of sugars and harvest maturity in sweet maize; the determination of oil in selected samples of high-oil maize types, and so forth. Breeding programmes for speciality maize, except high-amylose maize, have been implemented at the Maize Research Institute, Zemun Polje, Belgrade, for the last 45 years. A great number of high-yielding sweet maize hybrids, popping maize, high-oil and high-lysine, flint and white-seeded maize hybrids were developed during this 45-year period. Auspicious selection and breeding for these traits is facilitated by the abundant genetic variability and technical and technological possibilities necessary for successful selection.

  6. Identification of quantitative trait loci influencing wood specific gravity in an outbred pedigree of loblolly pine

    Science.gov (United States)

    A. Groover; M. Devey; T. Fiddler; J. Lee; R. Megraw; T. Mitchel-Olds; B. Sherman; S. Vujcic; C. Williams; D. Neale

    1994-01-01

    We report the identification of quantitative trait loci (QTL) influencing wood specific gravity (WSG) in an outbred pedigree of loblolly pine (Pinus taeda L.) . QTL mapping in an outcrossing species is complicated by the presence of multiple alleles (>2) at QTL and marker loci. Multiple alleles at QTL allow the examination of interaction among...

  7. Stenotrophomonas maltophilia virulence and specific variations in trace elements during acute lung infection: implications in cystic fibrosis.

    Directory of Open Access Journals (Sweden)

    Arianna Pompilio

    Full Text Available Metal ions are necessary for the proper functioning of the immune system, and, therefore, they might have a significant influence on the interaction between bacteria and host. Ionic dyshomeostasis has been recently observed also in cystic fibrosis (CF patients, whose respiratory tract is frequently colonized by Stenotrophomonas maltophilia. For the first time, here we used an inductively mass spectrometry method to perform a spatial and temporal analysis of the pattern of changes in a broad range of major trace elements in response to pulmonary infection by S. maltophilia. To this, DBA/2 mouse lungs were comparatively infected by a CF strain and by an environmental one. Our results showed that pulmonary ionomic profile was significantly affected during infection. Infected mice showed increased lung levels of Mg, P, S, K, Zn, Se, and Rb. To the contrary, Mn, Fe, Co, and Cu levels resulted significantly decreased. Changes of element concentrations were correlated with pulmonary bacterial load and markers of inflammation, and occurred mostly on day 3 post-exposure, when severity of infection culminated. Interestingly, CF strain - significantly more virulent than the environmental one in our murine model - provoked a more significant impact in perturbing pulmonary metal homeostasis. Particularly, exposure to CF strain exclusively increased P and K levels, while decreased Fe and Mn ones. Overall, our data clearly indicate that S. maltophilia modulates pulmonary metal balance in a concerted and virulence-dependent manner highlighting the potential role of the element dyshomeostasis during the progression of S. maltophilia infection, probably exacerbating the harmful effects of the loss of CF transmembrane conductance regulator function. Further investigations are required to understand the biological significance of these alterations and to confirm they are specifically caused by S. maltophilia.

  8. In Vitro Analysis of Pseudomonas aeruginosa Virulence Using Conditions That Mimic the Environment at Specific Infection Sites.

    Science.gov (United States)

    Colmer-Hamood, J A; Dzvova, N; Kruczek, C; Hamood, A N

    2016-01-01

    Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen that causes chronic lung infection in patients with cystic fibrosis (CF) and acute systemic infections in severely burned patients and immunocompromised patients including cancer patients undergoing chemotherapy and HIV infected individuals. In response to the environmental conditions at specific infection sites, P. aeruginosa expresses certain sets of cell-associated and extracellular virulence factors that produce tissue damage. Analyzing the mechanisms that govern the production of these virulence factors in vitro requires media that closely mimic the environmental conditions within the infection sites. In this chapter, we review studies based on media that closely resemble three in vivo conditions, the thick mucus accumulated within the lung alveoli of CF patients, the serum-rich wound bed and the bloodstream. Media resembling the CF alveolar mucus include standard laboratory media supplemented with sputum obtained from CF patients as well as prepared synthetic mucus media formulated to contain the individual components of CF sputum. Media supplemented with serum or individual serum components have served as surrogates for the soluble host components of wound infections, while whole blood has been used to investigate the adaptation of pathogens to the bloodstream. Studies using these media have provided valuable information regarding P. aeruginosa gene expression in different host environments as varying sets of genes were differentially regulated during growth in each medium. The unique effects observed indicate the essential role of these in vitro media that closely mimic the in vivo conditions in providing accurate information regarding the pathogenesis of P. aeruginosa infections. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Fast and efficient three-step target-specific curing of a virulence plasmid in Salmonella enterica.

    Science.gov (United States)

    de Moraes, Marcos H; Teplitski, Max

    2015-12-01

    Virulence plasmids borne by serovars of Salmonella enterica carry genes involved in its pathogenicity, as well as other functions. Characterization of phenotypes associated with virulence plasmids requires a system for efficiently curing strains of their virulence plasmids. Here, we developed a 3-step protocol for targeted curing of virulence plasmids. The protocol involves insertion of an I-SecI restriction site linked to an antibiotic resistance gene into the target plasmid using λ-Red mutagenesis, followed by the transformation with a temperature-sensitive auxiliary plasmid which carries I-SecI nuclease expressed from a tetracycline-inducible promoter. Finally, the auxiliary plasmid is removed by incubation at 42 °C and the plasmid-less strains are verified on antibiotic-containing media. This method is fast and very efficient: over 90 % of recovered colonies lacked their virulence plasmid.

  10. Trait liabilities and specific promotive processes in psychopathology: The example of suicidal behavior.

    Science.gov (United States)

    Buchman-Schmitt, Jennifer M; Brislin, Sarah J; Venables, Noah C; Joiner, Thomas E; Patrick, Christopher J

    2017-07-01

    The RDoC matrix framework calls for investigation of mental health problems through analysis of core biobehavioral processes quantified and studied across multiple domains of measurement. Critics have raised concerns about RDoC, including overemphasis on biological concepts/measures and disregard for the principle of multifinality, which holds that identical biological predispositions can give rise to differing behavioral outcomes. The current work illustrates an ontogenetic process approach to addressing these concerns, focusing on biobehavioral traits corresponding to RDoC constructs as predictors, and suicidal behavior as the outcome variable. Data were collected from a young adult sample (N=105), preselected to enhance rates of suicidality. Participants completed self-report measures of traits (threat sensitivity, response inhibition) and suicide-specific processes. We show that previously reported associations for traits of threat sensitivity and weak inhibitory control with suicidal behavior are mediated by more specific suicide-promoting processes-namely, thwarted belongingness, perceived burdensomeness, and capability for suicide. The sample was relatively small and the data were cross-sectional, limiting conclusions that can be drawn from the mediation analyses. Given prior research documenting neurophysiological as well as psychological bases to these trait dispositions, the current work sets the stage for an intensive RDoC-oriented investigation of suicidal tendencies in which both traits and suicide-promoting processes are quantified using indicators from different domains of measurement. More broadly, this work illustrates how an RDoC research approach can contribute to a nuanced understanding of specific clinical problems, through consideration of how general biobehavioral liabilities interface with distinct problem-promoting processes. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Comparative genomics reveals cotton-specific virulence factors in flexible genomic regions in Verticillium dahliae and evidence of horizontal gene transfer from Fusarium.

    Science.gov (United States)

    Chen, Jie-Yin; Liu, Chun; Gui, Yue-Jing; Si, Kai-Wei; Zhang, Dan-Dan; Wang, Jie; Short, Dylan P G; Huang, Jin-Qun; Li, Nan-Yang; Liang, Yong; Zhang, Wen-Qi; Yang, Lin; Ma, Xue-Feng; Li, Ting-Gang; Zhou, Lei; Wang, Bao-Li; Bao, Yu-Ming; Subbarao, Krishna V; Zhang, Geng-Yun; Dai, Xiao-Feng

    2018-01-01

    Verticillium dahliae isolates are most virulent on the host from which they were originally isolated. Mechanisms underlying these dominant host adaptations are currently unknown. We sequenced the genome of V. dahliae Vd991, which is highly virulent on its original host, cotton, and performed comparisons with the reference genomes of JR2 (from tomato) and VdLs.17 (from lettuce). Pathogenicity-related factor prediction, orthology and multigene family classification, transcriptome analyses, phylogenetic analyses, and pathogenicity experiments were performed. The Vd991 genome harbored several exclusive, lineage-specific (LS) genes within LS regions (LSRs). Deletion mutants of the seven genes within one LSR (G-LSR2) in Vd991 were less virulent only on cotton. Integration of G-LSR2 genes individually into JR2 and VdLs.17 resulted in significantly enhanced virulence on cotton but did not affect virulence on tomato or lettuce. Transcription levels of the seven LS genes in Vd991 were higher during the early stages of cotton infection, as compared with other hosts. Phylogenetic analyses suggested that G-LSR2 was acquired from Fusarium oxysporum f. sp. vasinfectum through horizontal gene transfer. Our results provide evidence that horizontal gene transfer from Fusarium to Vd991 contributed significantly to its adaptation to cotton and may represent a significant mechanism in the evolution of an asexual plant pathogen. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  12. Effect of Lineage-Specific Metabolic Traits of Lactobacillus reuteri on Sourdough Microbial Ecology

    OpenAIRE

    Lin, Xiaoxi B.; Gänzle, Michael G.

    2014-01-01

    This study determined the effects of specific metabolic traits of Lactobacillus reuteri on its competitiveness in sourdoughs. The competitiveness of lactobacilli in sourdough generally depends on their growth rate; acid resistance additionally contributes to competitiveness in sourdoughs with long fermentation times. Glycerol metabolism via glycerol dehydratase (gupCDE) accelerates growth by the regeneration of reduced cofactors; glutamate metabolism via glutamate decarboxylase (gadB) increas...

  13. Allele-specific physical interactions regulate the heterotic traits in hybrids of Arabidopsis thaliana ecotypes

    Directory of Open Access Journals (Sweden)

    Babita Singh

    2017-10-01

    Full Text Available Heterosis is an important phenomenon for the breeding in agricultural crops as it influences yield related traits such as biomass yield, seed number and weight, adaptive and reproductive traits. However, the level of heterosis greatly varies for different traits and different genotypes. The present study focuses on identification of physical interactions between alleles and their role in transcriptional regulation in heterotic plants. Here, we used two Arabidopsis ecotypes; Col-0 and C24 as parent for crosses. We performed crossing between these ecotypes and screened the F1 hybrids on the basis of different SSR markers. Further, we used Hi-C to capture intra- and inter-chromosomal physical interactions between alleles on genome-wide level. Then, we identified allele-specific chromatin interactions and constructed genome-wide allele-specific contact maps at different resolutions for the entire chromosome. We also performed RNA-seq of hybrids and their parents. RNA-seq analysis identified several differentially expressed genes and non-additively expressed genes in hybrids with respect to their parents. Further, to understand the biological significance of these chromatin interactions, we annotated these interactions and correlated with the transcriptome data. Thus, our study provides alleles-specific chromatin interactions in genome-wide fashion which play a crucial role in regulation of different genes that may be important for heterosis.

  14. Individual differences in personality traits reflect structural variance in specific brain regions.

    Science.gov (United States)

    Gardini, Simona; Cloninger, C Robert; Venneri, Annalena

    2009-06-30

    Personality dimensions such as novelty seeking (NS), harm avoidance (HA), reward dependence (RD) and persistence (PER) are said to be heritable, stable across time and dependent on genetic and neurobiological factors. Recently a better understanding of the relationship between personality traits and brain structures/systems has become possible due to advances in neuroimaging techniques. This Magnetic Resonance Imaging (MRI) study investigated if individual differences in these personality traits reflected structural variance in specific brain regions. A large sample of eighty five young adult participants completed the Three-dimensional Personality Questionnaire (TPQ) and had their brain imaged with MRI. A voxel-based correlation analysis was carried out between individuals' personality trait scores and grey matter volume values extracted from 3D brain scans. NS correlated positively with grey matter volume in frontal and posterior cingulate regions. HA showed a negative correlation with grey matter volume in orbito-frontal, occipital and parietal structures. RD was negatively correlated with grey matter volume in the caudate nucleus and in the rectal frontal gyrus. PER showed a positive correlation with grey matter volume in the precuneus, paracentral lobule and parahippocampal gyrus. These results indicate that individual differences in the main personality dimensions of NS, HA, RD and PER, may reflect structural variance in specific brain areas.

  15. Probing Birth-Order Effects on Narrow Traits Using Specification-Curve Analysis.

    Science.gov (United States)

    Rohrer, Julia M; Egloff, Boris; Schmukle, Stefan C

    2017-12-01

    The idea that birth-order position has a lasting impact on personality has been discussed for the past 100 years. Recent large-scale studies have indicated that birth-order effects on the Big Five personality traits are negligible. In the current study, we examined a variety of more narrow personality traits in a large representative sample ( n = 6,500-10,500 in between-family analyses; n = 900-1,200 in within-family analyses). We used specification-curve analysis to assess evidence for birth-order effects across a range of models implementing defensible yet arbitrary analytical decisions (e.g., whether to control for age effects or to exclude participants on the basis of sibling spacing). Although specification-curve analysis clearly confirmed the previously reported birth-order effect on intellect, we found no meaningful effects on life satisfaction, locus of control, interpersonal trust, reciprocity, risk taking, patience, impulsivity, or political orientation. The lack of meaningful birth-order effects on self-reports of personality was not limited to broad traits but also held for more narrowly defined characteristics.

  16. Phylogenetic Backgrounds and Virulence-Associated Traits of Escherichia coli Isolates from Surface Waters and Diverse Animals in Minnesota and Wisconsin.

    Science.gov (United States)

    Johnson, James R; Johnston, Brian D; Delavari, Parissa; Thuras, Paul; Clabots, Connie; Sadowsky, Michael J

    2017-12-15

    Possible external reservoirs for extraintestinal pathogenic Escherichia coli (ExPEC) strains that cause infections in humans are poorly defined. Because of the tremendous human health importance of ExPEC infections, we assessed surface waters and domesticated and wild animals in Minnesota and Wisconsin as potential reservoirs of ExPEC of human health relevance. We characterized 595 E. coli isolates (obtained from 1999 to 2002; 280 from seven surface water sites, 315 from feces of 13 wild and domesticated animal species) for phylogroup and virulence genotype, including inferred ExPEC status, by using multiplex PCR-based methods. We also compared the pulsed-field gel electrophoresis (PFGE) profiles of the isolates with a large private PFGE profile library. We found a predominance of non-ExPEC strains (95% and 93% among water and animal isolates, respectively), which were mainly from phylogroups A and B1, plus a minority of ExPEC strains (5% and 7% among water isolates and animal isolates, respectively), predominantly from phylogroup B2. The ExPEC strains, although significantly associated with cats, dogs, and turkeys, occurred in several additional animal species (goat, horse, chicken, pig) and were distributed broadly across all surface water sites. Virulence gene content among the animal source ExPEC isolates segregated significantly in relation to host species, following established patterns. PFGE analysis indicated that 11 study isolates closely matched (94% to 100% profile similarity) reference human clinical and fecal isolates. These findings imply what probably is a low but non-zero risk to humans from environmental and animal source E. coli isolates, especially those from specific human-associated animal species. IMPORTANCE Our detection of potentially pathogenic strains that may pose a health threat to humans among E. coli isolates from surface waters and wild and domesticated animals suggests a need for heightened attention to these reservoirs as possible

  17. Effect of lineage-specific metabolic traits of Lactobacillus reuteri on sourdough microbial ecology.

    Science.gov (United States)

    Lin, Xiaoxi B; Gänzle, Michael G

    2014-09-01

    This study determined the effects of specific metabolic traits of Lactobacillus reuteri on its competitiveness in sourdoughs. The competitiveness of lactobacilli in sourdough generally depends on their growth rate; acid resistance additionally contributes to competitiveness in sourdoughs with long fermentation times. Glycerol metabolism via glycerol dehydratase (gupCDE) accelerates growth by the regeneration of reduced cofactors; glutamate metabolism via glutamate decarboxylase (gadB) increases acid resistance by generating a proton motive force. Glycerol and glutamate metabolisms are lineage-specific traits in L. reuteri; therefore, this study employed glycerol dehydratase-positive sourdough isolates of human-adapted L. reuteri lineage I, glutamate decarboxylase-positive strains of rodent-adapted L. reuteri lineage II, as well as mutants with deletions in gadB or gupCDE. The competitivenesses of the strains were quantified by inoculation of wheat and sorghum sourdoughs with defined strains, followed by propagation of doughs with a 10% inoculum and 12-h or 72-h fermentation cycles. Lineage I L. reuteri strains dominated sourdoughs propagated with 12-h fermentation cycles; lineage II L. reuteri strains dominated sourdoughs propagated with 72-h fermentation cycles. L. reuteri 100-23ΔgadB was outcompeted by its wild-type strain in sourdoughs fermented with 72-h fermentation cycles; L. reuteri FUA3400ΔgupCDE was outcompeted by its wild-type strain in sourdoughs fermented with both 12-h and 72-h fermentation cycles. Competition experiments with isogenic pairs of strains resulted in a constant rate of strain displacement of the less competitive mutant strain. In conclusion, lineage-specific traits of L. reuteri determine the competitiveness of this species in sourdough fermentations. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  18. Correlations between personality traits and specific groups of alpha waves in the human EEG

    Directory of Open Access Journals (Sweden)

    Tomas Johannisson

    2016-07-01

    Full Text Available Background. Different individuals have alpha waves with different wavelengths. The distribution of the wavelengths is assumed to be bell-shaped and smooth. Although this view is generally accepted, it is still just an assumption and has never been critically tested. When exploring the relationship between alpha waves and personality traits, it makes a huge difference if the distribution of the alpha waves is smooth or if specific groups of alpha waves can be demonstrated. Previous studies have not considered the possibility that specific groups of alpha waves may exist. Methods. Computerized EEGs have become standard, but wavelength measurements are problematic when based on averaging procedures using the Fourier transformation because such procedures cause a large systematic error. If the actual wavelength is of interest, it is necessary to go back to basic physiology and use raw EEG signals. In the present study, measurements were made directly from sequences of alpha waves where every wave could be identified. Personality dimensions were measured using an inventory derived from the International Personality Item Pool. Results. Recordings from 200 healthy individuals revealed that there are three main groups of alpha waves. These groups had frequencies around 8, 10, and 12 waves per second. The middle group had a bimodal distribution, and a subdivision gave a total of four alpha groups. In the center of each group, the degree of extraversion was high and the degree of neuroticism was low. Many small differences in personality traits were found when the centers were compared with one another. This gave four personality profiles that resemble the four classical temperaments. When people in the surrounding zones were compared with those in the centers, relatively large differences in personality traits were found. Conclusions. Specific groups of alpha waves exist, and these groups have to be taken into account when correlations are made to

  19. Trait-specific responses of wild bee communities to landscape composition, configuration and local factors.

    Directory of Open Access Journals (Sweden)

    Sebastian Hopfenmüller

    Full Text Available Land-use intensification and loss of semi-natural habitats have induced a severe decline of bee diversity in agricultural landscapes. Semi-natural habitats like calcareous grasslands are among the most important bee habitats in central Europe, but they are threatened by decreasing habitat area and quality, and by homogenization of the surrounding landscape affecting both landscape composition and configuration. In this study we tested the importance of habitat area, quality and connectivity as well as landscape composition and configuration on wild bees in calcareous grasslands. We made detailed trait-specific analyses as bees with different traits might differ in their response to the tested factors. Species richness and abundance of wild bees were surveyed on 23 calcareous grassland patches in Southern Germany with independent gradients in local and landscape factors. Total wild bee richness was positively affected by complex landscape configuration, large habitat area and high habitat quality (i.e. steep slopes. Cuckoo bee richness was positively affected by complex landscape configuration and large habitat area whereas habitat specialists were only affected by the local factors habitat area and habitat quality. Small social generalists were positively influenced by habitat area whereas large social generalists (bumblebees were positively affected by landscape composition (high percentage of semi-natural habitats. Our results emphasize a strong dependence of habitat specialists on local habitat characteristics, whereas cuckoo bees and bumblebees are more likely affected by the surrounding landscape. We conclude that a combination of large high-quality patches and heterogeneous landscapes maintains high bee species richness and communities with diverse trait composition. Such diverse communities might stabilize pollination services provided to crops and wild plants on local and landscape scales.

  20. Trait-specific responses of wild bee communities to landscape composition, configuration and local factors.

    Science.gov (United States)

    Hopfenmüller, Sebastian; Steffan-Dewenter, Ingolf; Holzschuh, Andrea

    2014-01-01

    Land-use intensification and loss of semi-natural habitats have induced a severe decline of bee diversity in agricultural landscapes. Semi-natural habitats like calcareous grasslands are among the most important bee habitats in central Europe, but they are threatened by decreasing habitat area and quality, and by homogenization of the surrounding landscape affecting both landscape composition and configuration. In this study we tested the importance of habitat area, quality and connectivity as well as landscape composition and configuration on wild bees in calcareous grasslands. We made detailed trait-specific analyses as bees with different traits might differ in their response to the tested factors. Species richness and abundance of wild bees were surveyed on 23 calcareous grassland patches in Southern Germany with independent gradients in local and landscape factors. Total wild bee richness was positively affected by complex landscape configuration, large habitat area and high habitat quality (i.e. steep slopes). Cuckoo bee richness was positively affected by complex landscape configuration and large habitat area whereas habitat specialists were only affected by the local factors habitat area and habitat quality. Small social generalists were positively influenced by habitat area whereas large social generalists (bumblebees) were positively affected by landscape composition (high percentage of semi-natural habitats). Our results emphasize a strong dependence of habitat specialists on local habitat characteristics, whereas cuckoo bees and bumblebees are more likely affected by the surrounding landscape. We conclude that a combination of large high-quality patches and heterogeneous landscapes maintains high bee species richness and communities with diverse trait composition. Such diverse communities might stabilize pollination services provided to crops and wild plants on local and landscape scales.

  1. Spontaneous trait inference is culture-specific: behavioral and neural evidence.

    Science.gov (United States)

    Na, Jinkyung; Kitayama, Shinobu

    2011-08-01

    People with an independent model of the self may be expected to develop a spontaneous tendency to infer a personality trait from another person's behavior, but those with an interdependent model of the self may not show such a tendency. We tested this prediction by assessing the cumulative effect of both trait activation and trait binding in a diagnostic task that required no trait inference. Participants first memorized pairings of facial photos with trait-implying behavior. In a subsequent lexical decision task, European Americans showed clear evidence of spontaneous trait inference: When they were primed with a previously studied face, lexical decision for the word for the implied trait associated with that face was facilitated, and the antonym of the implied trait elicited an electrophysiological sign associated with processing of semantically inconsistent information (i.e., the N400). As predicted, however, neither effect was observed for Asian Americans. The cultural difference was mediated by independent self-construal.

  2. Genetic and environmental contributions to the inverse association between specific autistic traits and experience seeking in adults.

    Science.gov (United States)

    Romero-Martínez, Ángel; Moya-Albiol, Luís; Vinkhuyzen, Anna A E; Polderman, Tinca J C

    2016-12-01

    Autistic traits are characterized by social and communication problems, restricted, repetitive and stereotyped patterns of behavior, interests and activities. The relation between autistic traits and personality characteristics is largely unknown. This study focused on the relation between five specific autistic traits measured with the abridged version of the Autism Spectrum Quotient ("social problems," "preference for routine," "attentional switching difficulties," "imagination impairments," "fascination for numbers and patterns") and Experience Seeking (ES) in a general population sample of adults, and subsequently investigated the genetic and environmental etiology between these traits. Self-reported data on autistic traits and ES were collected in a population sample (n = 559) of unrelated individuals, and in a population based family sample of twins and siblings (n = 560). Phenotypic, genetic and environmental associations between traits were examined in a bivariate model, accounting for sex and age differences. Phenotypically, ES correlated significantly with "preference for routine" and "imagination impairments" in both samples but was unrelated to the other autistic traits. Genetic analyses in the family sample revealed that the association between ES and "preference for routine" and "imagination impairments" could largely be explained by a shared genetic factor (89% and 70%, respectively). Our analyses demonstrated at a phenotypic and genetic level an inverse relationship between ES and specific autistic traits in adults. ES is associated with risk taking behavior such as substance abuse, antisocial behavior and financial problems. Future research could investigate whether autistic traits, in particular strong routine preference and impaired imagination skills, serve as protective factors for such risky behaviors. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  3. Virulence, serotype and phylogenetic groups of diarrhoeagenic ...

    African Journals Online (AJOL)

    Dr DADIE Thomas

    2014-02-17

    Feb 17, 2014 ... The virulence, serotype and phylogenetic traits of diarrhoeagenic Escherichia coli were detected in 502 strains isolated during digestive infections. Molecular detection of the target virulence genes, rfb gene of operon O and phylogenetic grouping genes Chua, yjaA and TSPE4.C2 was performed.

  4. SOLiD sequencing of four Vibrio vulnificus genomes enables comparative genomic analysis and identification of candidate clade-specific virulence genes

    Directory of Open Access Journals (Sweden)

    Telonis-Scott Marina

    2010-09-01

    Full Text Available Abstract Background Vibrio vulnificus is the leading cause of reported death from consumption of seafood in the United States. Despite several decades of research on molecular pathogenesis, much remains to be learned about the mechanisms of virulence of this opportunistic bacterial pathogen. The two complete and annotated genomic DNA sequences of V. vulnificus belong to strains of clade 2, which is the predominant clade among clinical strains. Clade 2 strains generally possess higher virulence potential in animal models of disease compared with clade 1, which predominates among environmental strains. SOLiD sequencing of four V. vulnificus strains representing different clades (1 and 2 and biotypes (1 and 2 was used for comparative genomic analysis. Results Greater than 4,100,000 bases were sequenced of each strain, yielding approximately 100-fold coverage for each of the four genomes. Although the read lengths of SOLiD genomic sequencing were only 35 nt, we were able to make significant conclusions about the unique and shared sequences among the genomes, including identification of single nucleotide polymorphisms. Comparative analysis of the newly sequenced genomes to the existing reference genomes enabled the identification of 3,459 core V. vulnificus genes shared among all six strains and 80 clade 2-specific genes. We identified 523,161 SNPs among the six genomes. Conclusions We were able to glean much information about the genomic content of each strain using next generation sequencing. Flp pili, GGDEF proteins, and genomic island XII were identified as possible virulence factors because of their presence in virulent sequenced strains. Genomic comparisons also point toward the involvement of sialic acid catabolism in pathogenesis.

  5. The relationship between autistic traits and social anxiety, worry, obsessive-compulsive, and depressive symptoms: specific and non-specific mediators in a student sample.

    Science.gov (United States)

    Liew, Shi Min; Thevaraja, Nishta; Hong, Ryan Y; Magiati, Iliana

    2015-03-01

    The high prevalence of anxiety symptoms in individuals with autism spectrum disorders has now been well documented. There is also a positive relationship between autistic traits and anxiety symptoms in unselected samples and individuals with anxiety disorders have more autistic traits compared to those without. Less is known, however, regarding which elements of autistic traits (i.e., social versus non-social/behavioral) or which other variables may mediate this relationship. This study investigated the shared and specific role of five autistic-trait related mediators (social problem-solving, social competence, teasing experiences, prevention from/punishment for preferred repetitive behaviors and aversive sensory experiences) in a non-clinical sample of 252 university students. Autistic traits positively correlated with both anxiety and depressive symptoms. Social competence mediated the relationship between autistic traits and social anxiety symptoms only, while only prevention from preferred repetitive behaviors and frequent aversive sensory experiences mediated the relationship between autistic traits, worry and obsessive-compulsive symptoms. Replication of these findings is required in longitudinal studies and with clinical samples. Limitations of the study are discussed and possible implications for intervention are tentatively suggested.

  6. Crystal Structure of the LasA Virulence Factor from Pseudomonas aeruginosa: Substrate Specificity and Mechanism of M23 Metallopeptidases

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, James; Murphy, Loretta M.; Conners, Rebecca; Sessions, Richard B.; Gamblin, Steven J. (Wales); (Bristol Med Sci); (NIMR)

    2010-09-21

    Pseudomonas aeruginosa is an opportunist Gram-negative bacterial pathogen responsible for a wide range of infections in immunocompromized individuals and is a leading cause of mortality in cystic fibrosis patients. A number of secreted virulence factors, including various proteolytic enzymes, contribute to the establishment and maintenance of Pseudomonas infection. One such is LasA, an M23 metallopeptidase related to autolytic glycylglycine endopeptidases such as Staphylococcus aureus lysostaphin and LytM, and to DD-endopeptidases involved in entry of bacteriophage to host bacteria. LasA is implicated in a range of processes related to Pseudomonas virulence, including stimulating ectodomain shedding of the cell surface heparan sulphate proteoglycan syndecan-1 and elastin degradation in connective tissue. Here we present crystal structures of active LasA as a complex with tartrate and in the uncomplexed form. While the overall fold resembles that of the other M23 family members, the LasA active site is less constricted and utilizes a different set of metal ligands. The active site of uncomplexed LasA contains a five-coordinate zinc ion with trigonal bipyramidal geometry and two metal-bound water molecules. Using these structures as a starting point, we propose a model for substrate binding by LasA that explains its activity against a wider range of substrates than those used by related lytic enzymes, and offer a catalytic mechanism for M23 metallopeptidases consistent with available structural and mutagenesis data. Our results highlight how LasA is a structurally distinct member of this endopeptidase family, consistent with its activity against a wider range of substrates and with its multiple roles in Pseudomonas virulence.

  7. Trait anxiety affects decision-making differently in healthy men and women: towards gender-specific endophenotypes of anxiety.

    Science.gov (United States)

    de Visser, L; van der Knaap, L J; van de Loo, A J A E; van der Weerd, C M M; Ohl, F; van den Bos, R

    2010-05-01

    Excessive levels of trait anxiety are a risk factor for psychiatric conditions, including anxiety disorders and substance abuse. High trait anxiety has been associated with altered cognitive functioning, in particular with an attentional bias towards aversive stimuli. Decision-making is a crucial aspect of cognitive functioning that relies on the correct processing and control of emotional stimuli. Interestingly, anxiety and decision-making share underlying neural substrates, involving cortico-limbic pathways, including the amygdala, striatum and medial and dorsolateral prefrontal cortices. In the present study, we investigated the relationship between trait anxiety, measured by the State-Trait Anxiety Inventory, and complex decision-making, measured by the Iowa Gambling Task, in healthy male and female volunteers. The main focus of this study was the inclusion of gender as a discriminative factor. Indeed, we found distinct gender-specific effects of trait anxiety: in men, both low and high anxiety groups showed impaired decision-making compared to medium anxiety individuals, whereas in women only high anxiety individuals performed poorly. Furthermore, anxiety affected decision-making in men early in the task, i.e. the exploration phase, as opposed to an effect on performance in women during the second part of the test, i.e. the exploitation phase. These findings were related to different profiles of trait anxiety in men and women, and were independent of performance in the Wisconsin Card Sorting Test and cortisol levels. Our data show gender-specific effects of trait anxiety on emotional decision-making. We suggest gender-specific endophenotypes of anxiety to exist, that differentially affect cognitive functioning. 2010 Elsevier Ltd. All rights reserved.

  8. Unique aspects of impulsive traits in substance use and overeating: specific contributions of common assessments of impulsivity.

    Science.gov (United States)

    Beaton, Derek; Abdi, Hervé; Filbey, Francesca M

    2014-11-01

    Abstract Background: Impulsivity is a complex trait often studied in substance abuse and overeating disorders, but the exact nature of impulsivity traits and their contribution to these disorders are still debated. Thus, understanding how to measure impulsivity is essential for comprehending addictive behaviors. Identify unique impulsivity traits specific to substance use and overeating. Impulsive Sensation Seeking (ImpSS) and Barratt's Impulsivity scales (BIS) Scales were analyzed with a non-parametric factor analytic technique (discriminant correspondence analysis) to identify group-specific traits on 297 individuals from five groups: Marijuana (n = 88), Nicotine (n = 82), Overeaters (n = 27), Marijuauna + Nicotine (n = 63), and CONTROLs (n = 37). A significant overall factor structure revealed three components of impulsivity that explained respectively 50.19% (pperm Overeating: lacks focus, but plans (short and long term). Our results reveal impulsivity traits specific to each group. This may provide better criteria to define spectrums and trajectories - instead of categories - of symptoms for substance use and eating disorders. Defining symptomatic spectrums could be an important step forward in diagnostic strategies.

  9. Towards stressor-specific macroinvertebrate indices: Which traits and taxonomic groups are associated with vulnerable and tolerant taxa?

    Science.gov (United States)

    Berger, Elisabeth; Haase, Peter; Schäfer, Ralf B; Sundermann, Andrea

    2018-04-01

    Monitoring of macroinvertebrate communities is frequently used to define the ecological health status of rivers. Ideally, biomonitoring should also give an indication on the major stressors acting on the macroinvertebrate communities supporting the selection of appropriate management measures. However, most indices are affected by more than one stressor. Biological traits (e.g. size, generation time, reproduction) could potentially lead to more stressor-specific indices. However, such an approach has rarely been tested. In this study we classify 324 macroinvertebrate taxa as vulnerable (decreasing abundances) or tolerant (increasing abundances) along 21 environmental gradients (i.e. nutrients, major ions, oxygen and micropollutants) from 422 monitoring sites in Germany using Threshold Indicator Taxa Analysis (TITAN). Subsequently, we investigate which biological traits and taxonomic groups are associated with taxa classified as vulnerable or tolerant with regard to specific gradients. The response of most taxa towards different gradients was similar and especially high for correlated gradients. Traits associated with vulnerable taxa across most gradients included: larval aquatic life stages, isolated cemented eggs, reproductive cycle per year macrophytes, microphytes, silt or mud and a body size >2-4cm. Our results question whether stressor-specific indices based on macroinvertebrate assemblages can be achieved using single traits, because we observed that similar taxa responded to different gradients and also similar traits were associated with vulnerable and tolerant taxa across a variety of water quality gradients. Future studies should examine whether combinations of traits focusing on specific taxonomic groups achieve higher stressor specificity. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Prediction of Performance Facets using Specific Personality Traits in the Chinese Context.

    Science.gov (United States)

    Kwong, Jessica Y. Y.; Cheung, Fanny M.

    2003-01-01

    Data from the Chinese Personality Assessment Inventory for 187 Hong Kong supervisors showed that personality traits related to interpersonal orientation better predicted interpersonal versus personal contextual behaviors. Traits associated with moral obligation and group loyalty predicted personal but not interpersonal contextual behaviors.…

  11. The missing link: Bordetella petrii is endowed with both the metabolic versatility of environmental bacteria and virulence traits of pathogenic Bordetellae

    Directory of Open Access Journals (Sweden)

    Schneiker-Bekel Susanne

    2008-09-01

    Full Text Available Abstract Background Bordetella petrii is the only environmental species hitherto found among the otherwise host-restricted and pathogenic members of the genus Bordetella. Phylogenetically, it connects the pathogenic Bordetellae and environmental bacteria of the genera Achromobacter and Alcaligenes, which are opportunistic pathogens. B. petrii strains have been isolated from very different environmental niches, including river sediment, polluted soil, marine sponges and a grass root. Recently, clinical isolates associated with bone degenerative disease or cystic fibrosis have also been described. Results In this manuscript we present the results of the analysis of the completely annotated genome sequence of the B. petrii strain DSMZ12804. B. petrii has a mosaic genome of 5,287,950 bp harboring numerous mobile genetic elements, including seven large genomic islands. Four of them are highly related to the clc element of Pseudomonas knackmussii B13, which encodes genes involved in the degradation of aromatics. Though being an environmental isolate, the sequenced B. petrii strain also encodes proteins related to virulence factors of the pathogenic Bordetellae, including the filamentous hemagglutinin, which is a major colonization factor of B. pertussis, and the master virulence regulator BvgAS. However, it lacks all known toxins of the pathogenic Bordetellae. Conclusion The genomic analysis suggests that B. petrii represents an evolutionary link between free-living environmental bacteria and the host-restricted obligate pathogenic Bordetellae. Its remarkable metabolic versatility may enable B. petrii to thrive in very different ecological niches.

  12. Fusarium oxysporum f. sp. dianthi virus 1 accumulation is correlated with changes in virulence and other phenotypic traits of its fungal host.

    Science.gov (United States)

    Lemus-Minor, Carlos German; Cañizares-Nolasco, Carmen; García-Pedrajas, Maria D D; Pérez-Artés, Encarnación

    2018-03-08

    Fusarium oxysporum f. sp. dianthi virus 1 (FodV1) was detected in isolate Fod 116 (Fod 116V + ) of Fusarium oxysporum f. sp. dianthi (Fod), reaching such a high accumulation level that it was clearly visible after agarose gel electrophoresis of total DNA extracts. FodV1 consists of four double-stranded RNA segments, that correspond to a new mycovirus in the Chrysoviridae family. We obtained an isolate of Fod 116 (Fod 116V - ) with only a residual level of FodV1 RNA accumulation by single-conidia selection. Compared to the Fod 116V - , isolate Fod 116V + showed significant phenotypic alterations in vegetative growth and virulence. The presence of a high titer of mycovirus FodV1 thus associated with a modified morphology and a reduced growth of the colonies on solid medium, and with a diminished conidiation in liquid medium. Inoculation of four susceptible carnation cultivars with either Fod 116V - or Fod 116V + showed that the presence of a high titer of FodV1 was also correlated with a significantly reduced virulence of its fungal host. All the results suggest that FodV1 could be associated with hypovirulence, identifying it as a potential biocontrol agent against Fusarium wilt of carnation. This is the first report of a mycovirus potentially associated to the induction of hypovirulence in the species Fusarium oxysporum.

  13. The link between morphotype transition and virulence in Cryptococcus neoformans.

    Directory of Open Access Journals (Sweden)

    Linqi Wang

    Full Text Available Cryptococcus neoformans is a ubiquitous human fungal pathogen. This pathogen can undergo morphotype transition between the yeast and the filamentous form and such morphological transition has been implicated in virulence for decades. Morphotype transition is typically observed during mating, which is governed by pheromone signaling. Paradoxically, components specific to the pheromone signaling pathways play no or minimal direct roles in virulence. Thus, the link between morphotype transition and virulence and the underlying molecular mechanism remain elusive. Here, we demonstrate that filamentation can occur independent of pheromone signaling and mating, and both mating-dependent and mating-independent morphotype transition require the transcription factor Znf2. High expression of Znf2 is necessary and sufficient to initiate and maintain sex-independent filamentous growth under host-relevant conditions in vitro and during infection. Importantly, ZNF2 overexpression abolishes fungal virulence in murine models of cryptococcosis. Thus, Znf2 bridges the sex-independent morphotype transition and fungal pathogenicity. The impacts of Znf2 on morphological switch and pathogenicity are at least partly mediated through its effects on cell adhesion property. Cfl1, a Znf2 downstream factor, regulates morphogenesis, cell adhesion, biofilm formation, and virulence. Cfl1 is the first adhesin discovered in the phylum Basidiomycota of the Kingdom Fungi. Together with previous findings in other eukaryotic pathogens, our findings support a convergent evolution of plasticity in morphology and its impact on cell adhesion as a critical adaptive trait for pathogenesis.

  14. Is trait resilience characterized by specific patterns of attentional bias to emotional stimuli and attentional control?

    Science.gov (United States)

    Schäfer, Judith; Wittchen, Hans-Ulrich; Höfler, Michael; Heinrich, Anke; Zimmermann, Peter; Siegel, Stefan; Schönfeld, Sabine

    2015-09-01

    Attentional processes have been suggested to play a crucial role in resilience defined as positive adaptation facing adversity. However, research is lacking on associations between attentional biases to positive and threat-related stimuli, attentional control and trait resilience. Data stem from the follow-up assessment of a longitudinal study investigating mental health and related factors among German soldiers. Trait resilience was assessed with the Connor-Davidson Resilience Scale and attentional control with the Attentional Control Scale. A subset of n = 198 soldiers also completed a dot probe task with happy, neutral and threatening faces. Attentional control was positively related to trait resilience. Results revealed no associations between both attentional biases and trait resilience. However, there was a negative association between attentional bias to threat and trait resilience when attentional control was low and a positive association between attentional bias to threat and trait resilience when attentional control was high. No such associations were found for attentional bias to positive stimuli. Generalizability to other populations may be limited since we exclusively focused on male soldiers. Also, the cross-sectional design does not allow for causal conclusions. Findings suggest that attentional processing may promote trait resilience. Future research on preventive interventions should consider these findings. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Robust and Specific Personality Traits as Predictors of Adolescents' Final Grades and GPA at the End of Compulsory Schooling

    Science.gov (United States)

    Smrtnik Vitulic, Helena; Zupancic, Maja

    2013-01-01

    The study investigated the predictive value of robust and specific personality traits in adolescents (M[subscript age]?=?14.7 years), in explaining their academic achievement at the end of basic compulsory schooling. Personality data were obtained through self, maternal, and peer reports using the Inventory of Child/Adolescent Individual…

  16. Genome-wide association mapping of growth dynamics detects time-specific and general quantitative trait loci

    NARCIS (Netherlands)

    Bac-Molenaar, J.A.; Vreugdenhil, D.; Granier, C.; Keurentjes, J.J.B.

    2015-01-01

    Growth is a complex trait determined by the interplay between many genes, some of which play a role at a specific moment during development whereas others play a more general role. To identify the genetic basis of growth, natural variation in Arabidopsis rosette growth was followed in 324 accessions

  17. Trait Anger and Partner-Specific Anger Management Moderate the Temporal Association Between Alcohol Use and Dating Violence.

    Science.gov (United States)

    Shorey, Ryan C; McNulty, James K; Moore, Todd M; Stuart, Gregory L

    2017-03-01

    Research demonstrates alcohol temporally precedes and increases the odds of violence between intimate partners. However, despite an extensive theoretical literature on factors that likely moderate the relationship between alcohol and dating violence, minimal empirical research has examined such moderators. The purpose of the present study was to examine two potential moderators of this association: trait anger and partner-specific anger management. Undergraduate men (N = 67) who had consumed alcohol within the past month and were in current dating relationships completed a baseline assessment of their trait anger and partner-specific anger management skills and subsequently completed daily assessments of their alcohol use and violence perpetration (psychological, physical, and sexual) for up to 90 consecutive days. Alcohol was significantly associated with increased odds of physical aggression among men with relatively high but not low trait anger and partner-specific anger management deficits. In contrast, alcohol was significantly associated with increased odds of sexual aggression among men with relatively low trait anger and partner-specific anger management deficits. Our findings demonstrate important differences in the roles of acute intoxication and anger management in the risk of physical aggression and sexual dating violence. Interventions for dating violence may benefit from targeting both alcohol and adaptive anger management skills.

  18. Detection and Serogrouping of Dichelobacter nodosus Infection by Use of Direct PCR from Lesion Swabs To Support Outbreak-Specific Vaccination for Virulent Footrot in Sheep.

    Science.gov (United States)

    McPherson, Andrew S; Dhungyel, Om P; Whittington, Richard J

    2018-04-01

    Virulent footrot is an economically significant disease in most sheep-rearing countries. The disease can be controlled with vaccine targeting the fimbriae of virulent strains of the essential causative agent, Dichelobacter nodosus However, the bacterium is immunologically heterogeneous, and 10 distinct fimbrial serogroups have been identified. Ideally, in each outbreak the infecting strains would be cultured and serogrouped so that the appropriate serogroup-specific mono- or bivalent vaccine could be administered, because multivalent vaccines lack efficacy due to antigenic competition. If clinical disease expression is suspected to be incomplete, culture-based virulence tests are required to confirm the diagnosis, because control of benign footrot is economically unjustifiable. Both diagnosis and vaccination are conducted at the flock level. The aims of this study were to develop a PCR-based procedure for detecting and serogrouping D. nodosus directly from foot swabs and to determine whether this could be done accurately from the same cultured swab. A total of 269 swabs from the active margins of foot lesions of 261 sheep in 12 Merino sheep flocks in southeastern Australia were evaluated. DNA extracts taken from putative pure cultures of D. nodosus and directly from the swabs were evaluated in PCR assays for the 16S rRNA and fimA genes of D. nodosus Pure cultures were tested also by the slide agglutination test. Direct PCR using extracts from swabs was more sensitive than culture for detecting and serogrouping D. nodosus strains. Using the most sensitive sample collection method of the use of swabs in lysis buffer, D. nodosus was more likely to be detected by PCR in active than in inactive lesions, and in lesions with low levels of fecal contamination, but lesion score was not a significant factor. PCR conducted on extracts from swabs in modified Stuart's transport medium that had already been used to inoculate culture plates had lower sensitivity. Therefore, if

  19. The dopamine transporter gene may not contribute to susceptibility and the specific personality traits of amphetamine dependence.

    Science.gov (United States)

    Tzeng, Nian-Sheng; Lu, Ru-Band; Yeh, Hui-Wen; Yeh, Yi-Wei; Huang, Chang-Chih; Yen, Che-Hung; Kuo, Shin-Chang; Chen, Chun-Yen; Chang, Hsin-An; Ho, Pei-Shen; Cheng, Serena; Shih, Mei-Chen; Huang, San-Yuan

    2015-04-01

    A substantial amount of evidence suggests that dysfunction of the dopamine transporter may be involved in the pathophysiology of amphetamine dependence (AD). The aim of this study was to examine whether the dopamine transporter gene (DAT1, SLC6A3) is associated with development of AD and whether this gene influences personality traits in patients with AD. Eighteen polymorphisms of the DAT1 gene were analyzed in a case-control study that included 909 Han Chinese men (568 patients with AD and 341 control subjects). The patients fulfilled the DSM-IV-TR criteria for AD. The Tridimensional Personality Questionnaire (TPQ) was used to assess personality traits and to examine the association between these traits and DAT1 gene variants. A weak association was found between the rs27072 polymorphism and development of AD, but these borderline associations were unconfirmed by logistic regression and haplotype analysis. Although harm avoidance and novelty seeking scores were significantly higher in patients than in controls, DAT1 polymorphisms did not influence these scores. This study suggests that high harm avoidance and novelty seeking personality traits may be a risk factor for the development of AD. However, the DAT1 gene may not contribute to AD susceptibility and specific personality traits observed in AD among Han Chinese men. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Temporal Trends in Antimicrobial Resistance and Virulence-Associated Traits within the Escherichia coli Sequence Type 131 Clonal Group and Its H30 and H30-Rx Subclones, 1968 to 2012

    DEFF Research Database (Denmark)

    Olesen, Bente; Frimodt-Møller, Jakob; Leihof, Rikke Fleron

    2014-01-01

    occurred only after 2000 and 2002, respectively, in association with the H30 and H30-Rx subclones, which were characterized by multidrug resistance (including extended-spectrum-beta-lactamase [ESBL] production: H30-Rx) and absence of biofilm production. Capsular antigen K100 occurred exclusively among H30......-Rx ST131 subclones, rather than representing acquisition of resistance by diverse ST131 strains. Distinctive characteristics of the H30-Rx subclone-including specific virulence genes (iutA, afa and dra, kpsII), the K100 capsule, multidrug resistance, and ESBL production-possibly contributed...

  1. Strain-specific virulence phenotypes of Streptococcus pneumoniae assessed using the Chinchilla laniger model of otitis media.

    Directory of Open Access Journals (Sweden)

    Michael L Forbes

    2008-04-01

    Full Text Available Streptococcus pneumoniae [Sp] infection is associated with local and systemic disease. Our current understanding of the differential contributions of genetic strain variation, serotype, and host response to disease phenotype is incomplete. Using the chinchilla model of otitis media [OM] we investigated the disease phenotype generated by the laboratory strain TIGR4 and each of thirteen clinical strains (BS68-75, BS290, BS291, BS293, BS436 and BS437; eleven of the thirteen strains have been genomically sequenced.For each strain 100 colony forming units were injected bilaterally into the tympanic bullae of 6 young adult chinchillas under general anesthesia. All animals were examined daily for local and systemic disease by a blinded observer. Pneumatic otoscopy was used to evaluate local disease, and behavioral assessments served as the measure of systemic disease. Virulence scoring was performed using a 4-point scale to assess four clinical parameters [severity and rapidity of local disease onset; and severity and rapidity of systemic disease onset] during a 10-day evaluation period. Highly significant variation was observed among the strains in their ability to cause disease and moribundity.As expected, there was a significant correlation between the rapidity of systemic disease onset and severity of systemic disease; however, there was little correlation between the severity of otoscopic changes and severity of systemic disease. Importantly, it was observed that different strains of the same serotype produced as broad an array of disease phenotypes as did strains of different serotypes. We attribute these phenotypic differences among the strains to the high degree of genomic plasticity that we have previously documented.

  2. Isolation and characterization of a virulent bacteriophage SPW specific for Staphylococcus aureus isolated from bovine mastitis of lactating dairy cattle.

    Science.gov (United States)

    Li, Longping; Zhang, Zhiying

    2014-09-01

    Mastitis in dairy cattle continues to be an economically important disease. However, control is complicated by a high prevalence of resistance to antibiotics. Phage therapy, therefore, is considered as an alternative way of controlling bacterial infections and contaminations. In this study, we have described isolation and characterization of a highly virulent phage SPW from wastewater of dairy farm, which possesses a strong lytic capability against mastitis-associated Staphylococcus aureus, the most important pathogen in bovine clinical and subclinical mastitis. The phage SPW produced large, round and clear plaques on bacterial culture plates. TEM showed phage SPW has an icosahedral head 62.5 nm in diameter and long tail of 106 nm, head and tail were held together by a connector of 18 ± 1.5 nm long and can be classified as a member of the Myoviridae family. Restriction analysis indicated that phage SPW was a dsDNA virus with an approximate genome size of 65-69 kb. One-step growth kinetics showed a short latency period of about 10-15 min and a rise period of 50 min and a relatively small burst size was 44 ± 3 phages particles/infected cell. Moreover, adsorption rates were not influenced by calcium ions and phage SPW was relatively stable in a wide range of temperature and pH values, and resistant to chloroform and isopropanol. The optimal multiplicity of infection (MOI) was 0.01. When phage SPW was used to infect five other clinically isolated pathogenic isolates, it showed relatively wide spectrum host range. Phage SPW was capable of eliciting efficient lysis of S. aureus, revealing it potentially as an effective approach to prophylaxis or treatment of S. aureus-associated mastitis in dairy cows.

  3. Smoking-Specific Experiential Avoidance is Indirectly Associated with Trait Worry and Smoking Processes among Treatment-Seeking Smokers.

    Science.gov (United States)

    Farris, Samantha G; Zvolensky, Michael J; Norton, Peter J; Hogan, Julianna; Smith, Angela H; Talkovsky, Alexander M; Garey, Lorra; Schmidt, Norman B

    2016-01-01

    Limited work has examined worry, or apprehensive anticipation about future negative events, in terms of smoking. One potential explanatory factor is the tendency to respond inflexibly and with avoidance in the presence of smoking-related distress (smoking-specific experiential avoidance). Participants (n = 465) were treatment-seeking daily smokers. Cross-sectional (pre-treatment) self-report data were utilized to assess trait worry, smoking-specific experiential avoidance, and four smoking criterion variables: nicotine dependence, motivational aspects of quitting, perceived barriers to smoking cessation, and severity of problematic symptoms reported in past quit attempts. Trait worry was significantly associated with greater levels of nicotine dependence, motivation to quit smoking, perceived barriers for smoking cessation, and more severe problems while quitting in the past; associations occurred indirectly through higher levels of smoking-specific experiential avoidance. Findings provide initial support for the potential role of smoking-specific experiential avoidance in explaining the association between trait worry and a variety of smoking processes.

  4. Best linear unbiased prediction of genomic breeding values using a trait-specific marker-derived relationship matrix.

    Directory of Open Access Journals (Sweden)

    Zhe Zhang

    2010-09-01

    Full Text Available With the availability of high density whole-genome single nucleotide polymorphism chips, genomic selection has become a promising method to estimate genetic merit with potentially high accuracy for animal, plant and aquaculture species of economic importance. With markers covering the entire genome, genetic merit of genotyped individuals can be predicted directly within the framework of mixed model equations, by using a matrix of relationships among individuals that is derived from the markers. Here we extend that approach by deriving a marker-based relationship matrix specifically for the trait of interest.In the framework of mixed model equations, a new best linear unbiased prediction (BLUP method including a trait-specific relationship matrix (TA was presented and termed TABLUP. The TA matrix was constructed on the basis of marker genotypes and their weights in relation to the trait of interest. A simulation study with 1,000 individuals as the training population and five successive generations as candidate population was carried out to validate the proposed method. The proposed TABLUP method outperformed the ridge regression BLUP (RRBLUP and BLUP with realized relationship matrix (GBLUP. It performed slightly worse than BayesB with an accuracy of 0.79 in the standard scenario.The proposed TABLUP method is an improvement of the RRBLUP and GBLUP method. It might be equivalent to the BayesB method but it has additional benefits like the calculation of accuracies for individual breeding values. The results also showed that the TA-matrix performs better in predicting ability than the classical numerator relationship matrix and the realized relationship matrix which are derived solely from pedigree or markers without regard to the trait. This is because the TA-matrix not only accounts for the Mendelian sampling term, but also puts the greater emphasis on those markers that explain more of the genetic variance in the trait.

  5. Comparative analysis of virulence traits between a Legionella feeleii strain implicated in Pontiac fever and a strain that caused Legionnaires' disease.

    Science.gov (United States)

    Wang, Changle; Saito, Mitsumasa; Tanaka, Tamami; Amako, Kazunobu; Yoshida, Shin-ichi

    2015-12-01

    Legionella strains of the same species and serogroup are known to cause Legionnaires' disease (a potentially fatal atypical pneumonia) or Pontiac fever (a mild, flu-like disease), but the bacterial factors that define these dramatic differences in pathology have not been elucidated. To gain a better understanding of these factors, we compared the characteristics of Legionella feeleii strains that were isolated from either a sample of freshwater implicated in an outbreak of Pontiac fever (ATCC 35072, serogroup 1, LfPF), or a patient with Legionnaires' disease (ATCC 38549, serogroup 2, LfLD). Growth of LfPF and LfLD in BYE broth was slower than the positive control, Legionella pneumophila strain JR32. However, LfLD grew faster than LfPF at 42 °C. After in vitro infection to J774 murine or U937 human macrophage cell lines and A549 human lung epithelial cell line, LfLD showed a higher cell infection rate, stronger internalization by host cells, and greater cytotoxicity than that of LfPF. Large amounts of IL-6 and IL-8 were secreted by human host cells after infection with LfLD, but not with LfPF. LfLD possessed mono-polar flagellum while LfPF was unflagellated. When LfLD was cultured at 25, 30 and 37 °C, the bacteria had higher motility rate at lower temperatures. Based on our results, this is the first study that showed distinct characteristics between LfPF and LfLD, which may give important leads in elucidating differences in their virulence. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Lon protease modulates virulence traits in Erwinia amylovora by direct monitoring of major regulators and indirectly through the Rcs and Gac-Csr regulatory systems.

    Science.gov (United States)

    Lee, Jae Hoon; Ancona, Veronica; Zhao, Youfu

    2018-04-01

    Lon, an ATP-dependent protease in bacteria, influences diverse cellular processes by degrading damaged, misfolded and short-lived regulatory proteins. In this study, we characterized the effects of lon mutation and determined the molecular mechanisms underlying Lon-mediated virulence regulation in Erwinia amylovora, an enterobacterial pathogen of apple. Erwinia amylovora depends on the type III secretion system (T3SS) and the exopolysaccharide (EPS) amylovoran to cause disease. Our results showed that mutation of the lon gene led to the overproduction of amylovoran, increased T3SS gene expression and the non-motile phenotype. Western blot analyses showed that mutation in lon directly affected the accumulation and stability of HrpS/HrpA and RcsA. Mutation in lon also indirectly influenced the expression of flhD, hrpS and csrB through the accumulation of the RcsA/RcsB proteins, which bind to the promoter of these genes. In addition, lon expression is under the control of CsrA, possibly at both the transcriptional and post-transcriptional levels. Although mutation in csrA abolished both T3SS and amylovoran production, deletion of the lon gene in the csrA mutant only rescued amylovoran production, but not T3SS. These results suggest that CsrA might positively control both T3SS and amylovoran production partly by suppressing Lon, whereas CsrA may also play a critical role in T3SS by affecting unknown targets. © 2017 BSPP AND JOHN WILEY & SONS LTD.

  7. Trait anxiety predicts disease-specific health status in early-stage breast cancer patients

    NARCIS (Netherlands)

    van Esch, Lotje; Roukema, Jan A.; van der Steeg, Alida F. W.; de Vries, Jolanda

    2011-01-01

    The objectives of this study were to examine the differences in health status (HS) of women with breast cancer (BC) at different moments in time, and between women scoring high and not high on trait anxiety, and to identify possible predictors of HS 6 and 12 months after surgery. Patients (N = 223)

  8. Personality traits and gender-specific income expectations in Dutch higher education

    NARCIS (Netherlands)

    Need, Ariana; Jong, Uulkje de

    2008-01-01

    In this article we examine gender differences in income expectations of students in higher education. We found quite large gender differences. Men and women differ significantly in the income they expect to earn at the top of their career. We examined how much personality traits contribute to

  9. Gender-Specific Associations between Personality Traits, Physical Activity, and Body Size Dissatisfaction

    Science.gov (United States)

    Lodewyk, Ken; Sullivan, Philip

    2017-01-01

    A recently validated trait personality framework is the HEXACO (honesty-humility, emotionality, extraversion, agreeableness, conscientiousness, and openness to experience). Little is yet known about how the HEXACO personality dimensions and its subsets--particularly the dimension of honesty-humility--relates to physical activity and body size…

  10. Diabetes-specific genetic effects on obesity traits in American Indian populations: the Strong Heart Family Study

    Directory of Open Access Journals (Sweden)

    Howard Barbara V

    2008-10-01

    Full Text Available Abstract Background Body fat mass distribution and deposition are determined by multiple environmental and genetic factors. Obesity is associated with insulin resistance, hyperinsulinemia, and type 2 diabetes. We previously identified evidence for genotype-by-diabetes interaction on obesity traits in Strong Heart Family Study (SHFS participants. To localize these genetic effects, we conducted genome-wide linkage scans of obesity traits in individuals with and without type 2 diabetes, and in the combined sample while modeling interaction with diabetes using maximum likelihood methods (SOLAR 2.1.4. Methods SHFS recruited American Indians from Arizona, North and South Dakota, and Oklahoma. Anthropometric measures and diabetes status were obtained during a clinic visit. Marker allele frequencies were derived using maximum likelihood methods estimated from all individuals and multipoint identity by descent sharing was estimated using Loki. We used variance component linkage analysis to localize quantitative trait loci (QTLs influencing obesity traits. We tested for evidence of additive and QTL-specific genotype-by-diabetes interactions using the regions identified in the diabetes-stratified analyses. Results Among 245 diabetic and 704 non-diabetic American Indian individuals, we detected significant additive gene-by-diabetes interaction for weight and BMI (P P Conclusion These results suggest distinct genetic effects on body mass in individuals with diabetes compared to those without diabetes, and a possible role for one or more genes on chromosome 1 in the pathogenesis of obesity.

  11. Sex-specific influences of mtDNA mitotype and diet on mitochondrial functions and physiological traits in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Wen C Aw

    Full Text Available Here we determine the sex-specific influence of mtDNA type (mitotype and diet on mitochondrial functions and physiology in two Drosophila melanogaster lines. In many species, males and females differ in aspects of their energy production. These sex-specific influences may be caused by differences in evolutionary history and physiological functions. We predicted the influence of mtDNA mutations should be stronger in males than females as a result of the organelle's maternal mode of inheritance in the majority of metazoans. In contrast, we predicted the influence of diet would be greater in females due to higher metabolic flexibility. We included four diets that differed in their protein: carbohydrate (P:C ratios as they are the two-major energy-yielding macronutrients in the fly diet. We assayed four mitochondrial function traits (Complex I oxidative phosphorylation, reactive oxygen species production, superoxide dismutase activity, and mtDNA copy number and four physiological traits (fecundity, longevity, lipid content, and starvation resistance. Traits were assayed at 11 d and 25 d of age. Consistent with predictions we observe that the mitotype influenced males more than females supporting the hypothesis of a sex-specific selective sieve in the mitochondrial genome caused by the maternal inheritance of mitochondria. Also, consistent with predictions, we found that the diet influenced females more than males.

  12. Intra- and interspecific trait variations reveal functional relationships between specific leaf area and soil niche within a subtropical forest.

    Science.gov (United States)

    He, Dong; Chen, Yongfa; Zhao, Kangning; Cornelissen, J H C; Chu, Chengjin

    2018-02-03

    How functional traits vary with environmental conditions is of fundamental importance in trait-based community ecology. However, how intraspecific variability in functional traits is connected to species distribution is not well understood. This study investigated inter- and intraspecific variation of a key functional trait, i.e. specific leaf area (leaf area per unit dry mass; SLA), in relation to soil factors and tested if trait variation is more closely associated with specific environmental regimes for low-variability species than for high-variability species. In a subtropical evergreen forest plot (50 ha, southern China), 106 700 leaves from 5335 individuals of 207 woody species were intensively collected, with 30 individuals sampled for most species to ensure a sufficient sample size representative of intraspecific variability. Soil conditions for each plant were estimated by kriging from more than 1700 observational soil locations across the plot. Intra- and interspecific variation in SLA were separately related to environmental factors. Based on the species-specific variation of SLA, species were categorized into three groups: low-, intermediate- and high-intraspecific variability. Intraspecific habitat ranges and the strength of SLA-habitat relationships were compared among these three groups. Interspecific variation in SLA overrides the intraspecific variation (77 % vs. 8 %). Total soil nitrogen (TN, positively) and total organic carbon (TOC, negatively) are the most important explanatory factors for SLA variation at both intra- and interspecific levels. SLA, both within and between species, decreases with decreasing soil nitrogen availability. As predicted, species with low intraspecific variability in SLA have narrower habitat ranges with respect to soil TOC and TN and show a stronger SLA-habitat association than high-variability species. For woody plants low SLA is a phenotypic and probably adaptive response to nitrogen stress, which drives the

  13. Life Stage-specific Proteomes of Legionella pneumophila Reveal a Highly Differential Abundance of Virulence-associated Dot/Icm effectors*

    Science.gov (United States)

    Aurass, Philipp; Gerlach, Thomas; Becher, Dörte; Voigt, Birgit; Karste, Susanne; Bernhardt, Jörg; Riedel, Katharina; Hecker, Michael; Flieger, Antje

    2016-01-01

    Major differences in the transcriptional program underlying the phenotypic switch between exponential and post-exponential growth of Legionella pneumophila were formerly described characterizing important alterations in infection capacity. Additionally, a third state is known where the bacteria transform in a viable but nonculturable state under stress, such as starvation. We here describe phase-related proteomic changes in exponential phase (E), postexponential phase (PE) bacteria, and unculturable microcosms (UNC) containing viable but nonculturable state cells, and identify phase-specific proteins. We present data on different bacterial subproteomes of E and PE, such as soluble whole cell proteins, outer membrane-associated proteins, and extracellular proteins. In total, 1368 different proteins were identified, 922 were quantified and 397 showed differential abundance in E/PE. The quantified subproteomes of soluble whole cell proteins, outer membrane-associated proteins, and extracellular proteins; 841, 55, and 77 proteins, respectively, were visualized in Voronoi treemaps. 95 proteins were quantified exclusively in E, such as cell division proteins MreC, FtsN, FtsA, and ZipA; 33 exclusively in PE, such as motility-related proteins of flagellum biogenesis FlgE, FlgK, and FliA; and 9 exclusively in unculturable microcosms soluble whole cell proteins, such as hypothetical, as well as transport/binding-, and metabolism-related proteins. A high frequency of differentially abundant or phase-exclusive proteins was observed among the 91 quantified effectors of the major virulence-associated protein secretion system Dot/Icm (> 60%). 24 were E-exclusive, such as LepA/B, YlfA, MavG, Lpg2271, and 13 were PE-exclusive, such as RalF, VipD, Lem10. The growth phase-related specific abundance of a subset of Dot/Icm virulence effectors was confirmed by means of Western blotting. We therefore conclude that many effectors are predominantly abundant at either E or PE which suggests

  14. Combining quantitative trait loci analysis with physiological models to predict genotype-specific transpiration rates.

    Science.gov (United States)

    Reuning, Gretchen A; Bauerle, William L; Mullen, Jack L; McKay, John K

    2015-04-01

    Transpiration is controlled by evaporative demand and stomatal conductance (gs ), and there can be substantial genetic variation in gs . A key parameter in empirical models of transpiration is minimum stomatal conductance (g0 ), a trait that can be measured and has a large effect on gs and transpiration. In Arabidopsis thaliana, g0 exhibits both environmental and genetic variation, and quantitative trait loci (QTL) have been mapped. We used this information to create a genetically parameterized empirical model to predict transpiration of genotypes. For the parental lines, this worked well. However, in a recombinant inbred population, the predictions proved less accurate. When based only upon their genotype at a single g0 QTL, genotypes were less distinct than our model predicted. Follow-up experiments indicated that both genotype by environment interaction and a polygenic inheritance complicate the application of genetic effects into physiological models. The use of ecophysiological or 'crop' models for predicting transpiration of novel genetic lines will benefit from incorporating further knowledge of the genetic control and degree of independence of core traits/parameters underlying gs variation. © 2014 John Wiley & Sons Ltd.

  15. Helicobacter pylori virulence and cancer pathogenesis.

    Science.gov (United States)

    Yamaoka, Yoshio; Graham, David Y

    2014-06-01

    Helicobacter pylori is human gastric pathogen that causes chronic and progressive gastric mucosal inflammation and is responsible for the gastric inflammation-associated diseases, gastric cancer and peptic ulcer disease. Specific outcomes reflect the interplay between host-, environmental- and bacterial-specific factors. Progress in understanding putative virulence factors in disease pathogenesis has been limited and many false leads have consumed scarce resources. Few in vitro-in vivo correlations or translational applications have proved clinically relevant. Reported virulence factor-related outcomes reflect differences in relative risk of disease rather than specificity for any specific outcome. Studies of individual virulence factor associations have provided conflicting results. Since virulence factors are linked, studies of groups of putative virulence factors are needed to provide clinically useful information. Here, the authors discuss the progress made in understanding the role of H. pylori virulence factors CagA, vacuolating cytotoxin, OipA and DupA in disease pathogenesis and provide suggestions for future studies.

  16. Children's resilience and trauma-specific cognitive behavioral therapy: Comparing resilience as an outcome, a trait, and a process.

    Science.gov (United States)

    Happer, Kaitlin; Brown, Elissa J; Sharma-Patel, Komal

    2017-11-01

    Resilience, which is associated with relatively positive outcomes following negative life experiences, is an important research target in the field of child maltreatment (Luthar et al., 2000). The extant literature contains multiple conceptualizations of resilience, which hinders development in research and clinical utility. Three models emerge from the literature: resilience as an immediate outcome (i.e., behavioral or symptom response), resilience as a trait, and resilience as a dynamic process. The current study compared these models in youth undergoing trauma-specific cognitive behavioral therapy. Results provide the most support for resilience as a process, in which increase in resilience preceded associated decrease in posttraumatic stress and depressive symptoms. There was partial support for resilience conceptualized as an outcome, and minimal support for resilience as a trait. Results of the models are compared and discussed in the context of existing literature and in light of potential clinical implications for maltreated youth seeking treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Representational difference analysis of Neisseria meningitidis identifies sequences that are specific for the hyper-virulent lineage III clone

    NARCIS (Netherlands)

    Bart, A.; Dankert, J.; van der Ende, A.

    2000-01-01

    Neisseria meningitidis may cause meningitis and septicemia. Since the early 1980s, an increased incidence of meningococcal disease has been caused by the lineage III clone in many countries in Europe and in New Zealand. We hypothesized that lineage III meningococci have specific DNA sequences,

  18. An Efficient Stepwise Statistical Test to Identify Multiple Linked Human Genetic Variants Associated with Specific Phenotypic Traits.

    Directory of Open Access Journals (Sweden)

    Iksoo Huh

    Full Text Available Recent advances in genotyping methodologies have allowed genome-wide association studies (GWAS to accurately identify genetic variants that associate with common or pathological complex traits. Although most GWAS have focused on associations with single genetic variants, joint identification of multiple genetic variants, and how they interact, is essential for understanding the genetic architecture of complex phenotypic traits. Here, we propose an efficient stepwise method based on the Cochran-Mantel-Haenszel test (for stratified categorical data to identify causal joint multiple genetic variants in GWAS. This method combines the CMH statistic with a stepwise procedure to detect multiple genetic variants associated with specific categorical traits, using a series of associated I × J contingency tables and a null hypothesis of no phenotype association. Through a new stratification scheme based on the sum of minor allele count criteria, we make the method more feasible for GWAS data having sample sizes of several thousands. We also examine the properties of the proposed stepwise method via simulation studies, and show that the stepwise CMH test performs better than other existing methods (e.g., logistic regression and detection of associations by Markov blanket for identifying multiple genetic variants. Finally, we apply the proposed approach to two genomic sequencing datasets to detect linked genetic variants associated with bipolar disorder and obesity, respectively.

  19. Evolution of viral virulence: empirical studies

    Science.gov (United States)

    Kurath, Gael; Wargo, Andrew R.

    2016-01-01

    The concept of virulence as a pathogen trait that can evolve in response to selection has led to a large body of virulence evolution theory developed in the 1980-1990s. Various aspects of this theory predict increased or decreased virulence in response to a complex array of selection pressures including mode of transmission, changes in host, mixed infection, vector-borne transmission, environmental changes, host vaccination, host resistance, and co-evolution of virus and host. A fundamental concept is prediction of trade-offs between the costs and benefits associated with higher virulence, leading to selection of optimal virulence levels. Through a combination of observational and experimental studies, including experimental evolution of viruses during serial passage, many of these predictions have now been explored in systems ranging from bacteriophage to viruses of plants, invertebrates, and vertebrate hosts. This chapter summarizes empirical studies of viral virulence evolution in numerous diverse systems, including the classic models myxomavirus in rabbits, Marek's disease virus in chickens, and HIV in humans. Collectively these studies support some aspects of virulence evolution theory, suggest modifications for other aspects, and show that predictions may apply in some virus:host interactions but not in others. Finally, we consider how virulence evolution theory applies to disease management in the field.

  20. Strain-specific impact of PsaR of Streptococcus pneumoniae on global gene expression and virulence

    OpenAIRE

    Hendriksen, Wouter T.; Bootsma, Hester J.; van Diepen, Angela; Estevao, Silvia; Kuipers, Oscar P.; de Groot, Ronald; Hermans, Peter W. M.

    2009-01-01

    Previous studies have indicated that PsaR of Streptococcus pneumoniae is a manganese-dependent regulator, negatively affecting the expression of at least seven genes. Here, we extended these observations by transcriptome and proteome analysis of psaR mutants in strains D39 and TIGR4. The microarray analysis identified three shared PsaR targets: the psa operon, pcpA and prtA. In addition, we found 31 genes to be regulated by PsaR in D39 only, most strikingly a cellobiose-specific phosphotrains...

  1. A face for all seasons: Searching for context-specific leadership traits and discovering a general preference for perceived health

    Directory of Open Access Journals (Sweden)

    Brian R. Spisak

    2014-11-01

    Full Text Available Previous research indicates that followers tend to contingently match particular leader qualities to evolutionarily consistent situations requiring collective action (i.e., context-specific cognitive leadership prototypes and information processing undergoes categorization which ranks certain qualities as first-order context-general and others as second-order context-specific. To further investigate this contingent categorization phenomenon we examined the attractiveness halo – a first-order facial cue which significantly biases leadership preferences. While controlling for facial attractiveness, we independently manipulated the underlying facial cues of health and intelligence and then primed participants with four distinct organizational dynamics requiring leadership (i.e., competition versus cooperation between groups and exploratory change versus stable exploitation. It was expected that the differing requirements of the four dynamics would contingently select for relatively healthier- or intelligent-looking leaders. We found perceived facial intelligence to be a second-order context-specific trait – for instance, in times requiring a leader to address between-group cooperation – whereas perceived health is significantly preferred across all contexts (i.e., a first-order trait. The results also indicate that facial health positively affects perceived masculinity while facial intelligence negatively affects perceived masculinity, which may partially explain leader choice in some of the environmental contexts. The limitations and a number of implications regarding leadership biases are discussed.

  2. Pathogen-specific effects of quantitative trait loci affecting clinical mastitis and somatic cell count in danish holstein cattle

    DEFF Research Database (Denmark)

    Sørensen, Lars Peter; Guldbrandtsen, Bernt; Thomasen, J.R.

    2008-01-01

    The aim of this study was to investigate whether quantitative trait loci (QTL) affecting the risk of clinical mastitis (CM) and QTL affecting somatic cell score (SCS) exhibit pathogen-specific effects on the incidence of mastitis. Bacteriological data on mastitis pathogens were used to investigate...... pathogen specificity of QTL affecting treatments of mastitis in first parity (CM1), second parity (CM2), and third parity (CM3), and QTL affecting SCS. The 5 most common mastitis pathogens in the Danish dairy population were analyzed: Streptococcus dysgalactiae, Escherichia coli, coagulase...... against coagulase-negative staphylococci and Strep. uberis. Our results show that particular mastitis QTL are highly likely to exhibit pathogen-specificity. However, the results should be interpreted carefully because the results are sensitive to the sampling method and method of analysis. Field data were...

  3. Bursal immunopathology responses of specific-pathogen-free chickens and red jungle fowl infected with very virulent infectious bursal disease virus.

    Science.gov (United States)

    Farhanah, Mohd Isa; Yasmin, Abdul Rahaman; Khanh, Nguyen Phuc; Yeap, Swee Keong; Hair-Bejo, Mohd; Omar, Abdul Rahman

    2018-04-06

    Very virulent infectious bursal disease virus (vvIBDV) targets B lymphocytes in the bursa of Fabricius (BF), causing immunosuppression and increased mortality rates in young birds. There have been few studies on the host immune response following vvIBDV infection at different inoculum doses in chickens with different genetic backgrounds. In this study, we characterized the immune responses of specific-pathogen-free (SPF) chickens and Malaysian red jungle fowl following infection with vvIBDV strain UPM0081 at 10 3.8 and 10 6.8 times the 50% embryo infectious dose (EID 50 ). The viral burden, histopathological changes, immune cell populations, and expression of immune-related genes were measured and compared between infected and uninfected bursa at specific intervals. The populations of KUL1 + , CD3 + CD4 + and CD3 + CD8 + cells were significantly increased in both types of chickens at 3 dpi, and there was significant early depletion of IgM + B cells at 1 dpi in the red jungle fowl. vvIBDV infection also induced differential expression of genes that are involved in Th1 and pro-inflammatory responses, with groups receiving the higher dose (10 6.8 EID 50 ) showing earlier expression of IFNG, IL12B, IL15, IL6, CXCLi2, IL28B, and TLR3 at 1 dpi. Although both chicken types showed equal susceptibility to infection, the red jungle fowl were clinically healthier than the SPF chickens despite showing more depletion of IgM + B cells and failure to induce IFNB activation. In conclusion, high-dose vvIBDV infection caused an intense early host immune response in the infected bursa, with depletion of IgM + B cells, bursal lesions, and cytokine expression as a response to mitigate the severity of the infection.

  4. Trait-specific long-term consequences of genomic selection in beef cattle.

    Science.gov (United States)

    de Rezende Neves, Haroldo Henrique; Carvalheiro, Roberto; de Queiroz, Sandra Aidar

    2018-02-01

    Simulation studies allow addressing consequences of selection schemes, helping to identify effective strategies to enable genetic gain and maintain genetic diversity. The aim of this study was to evaluate the long-term impact of genomic selection (GS) in genetic progress and genetic diversity of beef cattle. Forward-in-time simulation generated a population with pattern of linkage disequilibrium close to that previously reported for real beef cattle populations. Different scenarios of GS and traditional pedigree-based BLUP (PBLUP) selection were simulated for 15 generations, mimicking selection for female reproduction and meat quality. For GS scenarios, an alternative selection criterion was simulated (wGBLUP), intended to enhance long-term gains by attributing more weight to favorable alleles with low frequency. GS allowed genetic progress up to 40% greater than PBLUP, for female reproduction and meat quality. The alternative criterion wGBLUP did not increase long-term response, although allowed reducing inbreeding rates and loss of favorable alleles. The results suggest that GS outperforms PBLUP when the selected trait is under less polygenic background and that attributing more weight to low-frequency favorable alleles can reduce inbreeding rates and loss of favorable alleles in GS.

  5. "Lacking warmth": Alexithymia trait is related to warm-specific thermal somatosensory processing.

    Science.gov (United States)

    Borhani, Khatereh; Làdavas, Elisabetta; Fotopoulou, Aikaterini; Haggard, Patrick

    2017-09-01

    Alexithymia is a personality trait involving deficits in emotional processing. The personality construct has been extensively validated, but the underlying neural and physiological systems remain controversial. One theory suggests that low-level somatosensory mechanisms act as somatic markers of emotion, underpinning cognitive and affective impairments in alexithymia. In two separate samples (total N=100), we used an established Quantitative Sensory Testing (QST) battery to probe multiple neurophysiological submodalities of somatosensation, and investigated their associations with the widely-used Toronto Alexithymia Scale (TAS-20). Experiment one found reduced sensitivity to warmth in people with higher alexithymia scores, compared to individuals with lower scores, without deficits in other somatosensory submodalities. Experiment two replicated this result in a new group of participants using a full-sample correlation between threshold for warm detection and TAS-20 scores. We discuss the relations between low-level thermoceptive function and cognitive processing of emotion. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  6. The impact of case specificity and generalisable skills on clinical performance: a correlated traits-correlated methods approach.

    Science.gov (United States)

    Wimmers, Paul F; Fung, Cha-Chi

    2008-06-01

    The finding of case or content specificity in medical problem solving moved the focus of research away from generalisable skills towards the importance of content knowledge. However, controversy about the content dependency of clinical performance and the generalisability of skills remains. This study aimed to explore the relative impact of both perspectives (case specificity and generalisable skills) on different components (history taking, physical examination, communication) of clinical performance within and across cases. Data from a clinical performance examination (CPX) taken by 350 Year 3 students were used in a correlated traits-correlated methods (CTCM) approach using confirmatory factor analysis, whereby 'traits' refers to generalisable skills and 'methods' to individual cases. The baseline CTCM model was analysed and compared with four nested models using structural equation modelling techniques. The CPX consisted of three skills components and five cases. Comparison of the four different models with the least-restricted baseline CTCM model revealed that a model with uncorrelated generalisable skills factors and correlated case-specific knowledge factors represented the data best. The generalisable processes found in history taking, physical examination and communication were responsible for half the explained variance, in comparison with the variance related to case specificity. Conclusions Pure knowledge-based and pure skill-based perspectives on clinical performance both seem too one-dimensional and new evidence supports the idea that a substantial amount of variance contributes to both aspects of performance. It could be concluded that generalisable skills and specialised knowledge go hand in hand: both are essential aspects of clinical performance.

  7. Mammalian-specific genomic functions: Newly acquired traits generated by genomic imprinting and LTR retrotransposon-derived genes in mammals.

    Science.gov (United States)

    Kaneko-Ishino, Tomoko; Ishino, Fumitoshi

    2015-01-01

    Mammals, including human beings, have evolved a unique viviparous reproductive system and a highly developed central nervous system. How did these unique characteristics emerge in mammalian evolution, and what kinds of changes did occur in the mammalian genomes as evolution proceeded? A key conceptual term in approaching these issues is "mammalian-specific genomic functions", a concept covering both mammalian-specific epigenetics and genetics. Genomic imprinting and LTR retrotransposon-derived genes are reviewed as the representative, mammalian-specific genomic functions that are essential not only for the current mammalian developmental system, but also mammalian evolution itself. First, the essential roles of genomic imprinting in mammalian development, especially related to viviparous reproduction via placental function, as well as the emergence of genomic imprinting in mammalian evolution, are discussed. Second, we introduce the novel concept of "mammalian-specific traits generated by mammalian-specific genes from LTR retrotransposons", based on the finding that LTR retrotransposons served as a critical driving force in the mammalian evolution via generating mammalian-specific genes.

  8. Petroleum Hydrocarbon Mixture Toxicity and a Trait Based Approach to Soil Invertebrate Species for Site Specific Risk Assessments.

    Science.gov (United States)

    Gainer, Amy; Cousins, Mark; Hogan, Natacha; Siciliano, Steven D

    2018-05-05

    Although petroleum hydrocarbons (PHCs) released to the environment typically occur as mixtures, PHC remediation guidelines often reflect individual substance toxicity. It is well documented that groups of aliphatic PHCs act via the same mechanism of action, nonpolar narcosis and, theoretically, concentration addition mixture toxicity principles apply. To assess this theory, ten standardized acute and chronic soil invertebrate toxicity tests on a range of organisms (Eisenia fetida, Lumbricus terrestris, Enchytraeus crypticus, Folsomia candida, Oppia nitens and Hypoaspis aculeifer) were conducted with a refined PHC binary mixture. Reference models for concentration addition and independent action were applied to the mixture toxicity data with consideration of synergism, antagonism and dose level toxicity. Both concentration addition and independent action, without further interactions, provided the best fit with observed response to the mixture. Individual fraction effective concentration values were predicted from optimized, fitted reference models. Concentration addition provided a better estimate than independent action of individual fraction effective concentrations based on comparison with available literature and species trends observed in toxic responses to the mixture. Interspecies differences in standardized laboratory soil invertebrate species responses to PHC contaminated soil was reflected in unique traits. Diets that included soil, large body size, permeable cuticle, low lipid content, lack of ability to molt and no maternal transfer were traits linked to a sensitive survival response to PHC contaminated soil in laboratory tests. Traits linked to sensitive reproduction response in organisms tested were long life spans with small clutch sizes. By deriving single fraction toxicity endpoints considerate of mixtures, we reduce resources and time required in conducting site specific risk assessments for the protection of soil organism's exposure pathway. This

  9. Assessment of General and Specific Combining Ability and Heterosis of Some Cucumber (Cucumis sativus L. Lines for Vegetative Traits

    Directory of Open Access Journals (Sweden)

    Fatemeh Moradipour

    2017-10-01

    Full Text Available Introduction: Cucumber (Cucumis sativus L. is one of the most widely cultivated vegetables. Plant length is a quantitative trait is controlled by many genes. These traits are difficult to study due to the complex nature of their inheritance. The combining ability estimation is useful in determining the breeding value of cucumber lines by suggesting the appropriate use in a breeding program. In studying combining ability, the most commonly utilized experimental approach is the diallel design. General combining ability is a measure of additive genetic action; and specific combining ability (SCA is deviation from additivity. General combining ability is a main effect and SCA is an interaction. The aim is to determine the breeding value of the cross. Heterosis has been utilized to exploit dominance variance through production of hybrids. There are reports on positive and negative heterosis in cucumber however, there are differences between reports. This research was conducted to estimate general and specific combining ability and heterosis in cucumber inbred lines and hybrids to produce hybrids with high yield and quality. Material and Methods: In the spring of 2014, the seven parental lines and their 21 F1 hybrid were planted at the University of Guilan, in loamy sand field. Three replications were arranged in a randomized complete block design. The sandy loam soil was prepared by plowing and disking and formed into raised beds by plowed and harrow prior to plant establishment. Rows were on 1 m centers and plants were about 25 cm apart in the row. Prior to planting 150 kg·ha-1 of nitrogen from urea and 100 kg·ha-1 of phosphorous from triple superphosphate and 80 kg·ha-1 of potassium sulfate was applied. Side dressing with the same amount of nitrogen and phosphorus occurred at 50% flowering stage. Irrigation with 250 m3·ha-1, three times weekly, was begun at plant first flowering. In each replication, 12 individuals of each line or hybrid were

  10. Callous-unemotional traits and brain structure: Sex-specific effects in anterior insula of typically-developing youths

    Directory of Open Access Journals (Sweden)

    Nora Maria Raschle

    2018-01-01

    General scientific summary: This study suggests that callous-unemotional traits have a neuroanatomical correlate within typically developing boys, but not girls. Bilateral anterior insula volume explains up to 19% of the variance in callous-unemotional traits in boys.

  11. QTL analyses on genotype-specific component traits in a crop simulation model for capsicum annuum L.

    NARCIS (Netherlands)

    Wubs, A.M.; Heuvelink, E.; Dieleman, J.A.; Magan, J.J.; Palloix, A.; Eeuwijk, van F.A.

    2012-01-01

    Abstract: QTL for a complex trait like yield tend to be unstable across environments and show QTL by environment interaction. Direct improvement of complex traits by selecting on QTL is therefore difficult. For improvement of complex traits, crop growth models can be useful, as such models can

  12. Sex-specific differences of craniofacial traits in Croatia: the impact of environment in a small geographic area.

    Science.gov (United States)

    Buretic-Tomljanovic, Alena; Giacometti, Jasminka; Ostojic, Sasa; Kapovic, Miljenko

    2007-01-01

    Craniometric variation in humans reflects different genetic and environmental influences. Long-term climatic adaptation is less likely to show an impact on size and shape variation in a small local area than at the global level. The aim of this work was to assess the contribution of the particular environmental factors to body height and craniofacial variability in a small geographic area of Croatia. A total of 632 subjects, aged 18-21, participated in the survey. Body height, head length, head breadth, head height, head circumference, cephalic index, morphological face height, face breadth, and facial index were analysed regarding geographic, climatic and dietary conditions in different regions of the country, and correlated with the specific climatic variables (cumulative multiyear sunshine duration, cumulative multiyear average precipitation, multiyear average air temperatures) and calcium concentrations in drinking water. Significant differences between groups classified according to geographic, climatic or dietary affiliation, and the impact of the environmental predictors on the variation in the investigated traits were assessed using multiple forward stepwise regression analyses. Higher body height measures in both sexes were significantly correlated with Mediterranean diet type. Mediterranean diet type also contributed to higher head length and head circumference measures in females. Cephalic index values correlated to geographic regions in both sexes, showing an increase from southern to eastern Croatia. In the same direction, head length significantly decreased in males and head breadth increased in females. Mediterranean climate was associated with higher and narrower faces in females. The analysis of the particular climatic variables did not reveal a significant influence on body height in either sex. Concurrently, climatic features influenced all craniofacial traits in females and only head length and facial index in males. Mediterranean climate

  13. Incompleteness as a link between obsessive-compulsive personality traits and specific symptom dimensions of obsessive-compulsive disorder.

    Science.gov (United States)

    Ecker, Willi; Kupfer, Jochen; Gönner, Sascha

    2014-01-01

    This paper examines the contribution of incompleteness/'not just right experiences' (NJREs) to an understanding of the relationship between obsessive-compulsive disorder (OCD) and obsessive-compulsive personality traits (OCPTs). It investigates the association of specific OCD symptom dimensions with OCPTs, conceptualized as continuous phenomena that are also observable below the diagnostic threshold. As empirical findings and clinical observation suggest that incompleteness feelings/NJREs may play a significant affective and motivational role for certain OCD subtypes, but also for patients with accentuated OCPTs, we hypothesized that OCPTs are selectively linked with incompleteness-associated OCD symptom dimensions (ordering, checking, hoarding and counting). Moreover, we assumed that this selective relationship cannot be demonstrated any more after statistical control of incompleteness, whereas it is preserved after statistical control of anxiety, depression, pathological worry and harm avoidance. Results from a study with a large clinical sample (n = 185) partially support these hypotheses and suggest that NJREs may be an important connecting link between specific OCD symptom dimensions, in particular ordering and checking, and accentuated OCPTs. Obsessive-compulsive personality traits (OCPTs) are positively related to obsessive-compulsive disorder symptom dimensions (ordering, checking, hoarding and counting) hypothesized or found to be associated with incompleteness/'not just right experiences' (NJREs), but not to washing and obsessions. This positive relationship, which is strongest for ordering and checking, is eliminated when NJREs are statistically controlled. Ordering, checking and accentuated OCPTs may share NJREs as a common affective-motivational underpinning.Dysfunctional behaviour patterns of people with accentuated OCPTs or obsessive-compulsive personality disorder (OCPD) may be viewed as efforts to avoid or reduce subjectively intolerable NJREs

  14. Association of clustered regularly interspaced short palindromic repeat (CRISPR) elements with specific serotypes and virulence potential of shiga toxin-producing Escherichia coli.

    Science.gov (United States)

    Toro, Magaly; Cao, Guojie; Ju, Wenting; Allard, Marc; Barrangou, Rodolphe; Zhao, Shaohua; Brown, Eric; Meng, Jianghong

    2014-02-01

    Shiga toxin-producing Escherichia coli (STEC) strains (n = 194) representing 43 serotypes and E. coli K-12 were examined for clustered regularly interspaced short palindromic repeat (CRISPR) arrays to study genetic relatedness among STEC serotypes. A subset of the strains (n = 81) was further analyzed for subtype I-E cas and virulence genes to determine a possible association of CRISPR elements with potential virulence. Four types of CRISPR arrays were identified. CRISPR1 and CRISPR2 were present in all strains tested; 1 strain also had both CRISPR3 and CRISPR4, whereas 193 strains displayed a short, combined array, CRISPR3-4. A total of 3,353 spacers were identified, representing 528 distinct spacers. The average length of a spacer was 32 bp. Approximately one-half of the spacers (54%) were unique and found mostly in strains of less common serotypes. Overall, CRISPR spacer contents correlated well with STEC serotypes, and identical arrays were shared between strains with the same H type (O26:H11, O103:H11, and O111:H11). There was no association identified between the presence of subtype I-E cas and virulence genes, but the total number of spacers had a negative correlation with potential pathogenicity (P CRISPR-cas system and potential virulence needs to be determined on a broader scale, and the biological link will need to be established.

  15. A face for all seasons: Searching for context-specific leadership traits and discovering a general preference for perceived health

    Science.gov (United States)

    Spisak, Brian R.; Blaker, Nancy M.; Lefevre, Carmen E.; Moore, Fhionna R.; Krebbers, Kleis F. B.

    2014-01-01

    Previous research indicates that followers tend to contingently match particular leader qualities to evolutionarily consistent situations requiring collective action (i.e., context-specific cognitive leadership prototypes) and information processing undergoes categorization which ranks certain qualities as first-order context-general and others as second-order context-specific. To further investigate this contingent categorization phenomenon we examined the “attractiveness halo”—a first-order facial cue which significantly biases leadership preferences. While controlling for facial attractiveness, we independently manipulated the underlying facial cues of health and intelligence and then primed participants with four distinct organizational dynamics requiring leadership (i.e., competition vs. cooperation between groups and exploratory change vs. stable exploitation). It was expected that the differing requirements of the four dynamics would contingently select for relatively healthier- or intelligent-looking leaders. We found perceived facial intelligence to be a second-order context-specific trait—for instance, in times requiring a leader to address between-group cooperation—whereas perceived health is significantly preferred across all contexts (i.e., a first-order trait). The results also indicate that facial health positively affects perceived masculinity while facial intelligence negatively affects perceived masculinity, which may partially explain leader choice in some of the environmental contexts. The limitations and a number of implications regarding leadership biases are discussed. PMID:25414653

  16. Experimental evaluation of the relationship between lethal or non-lethal virulence and transmission success in malaria parasite infections

    Directory of Open Access Journals (Sweden)

    Nithiuthai S

    2004-09-01

    Full Text Available Abstract Background Evolutionary theory suggests that the selection pressure on parasites to maximize their transmission determines their optimal host exploitation strategies and thus their virulence. Establishing the adaptive basis to parasite life history traits has important consequences for predicting parasite responses to public health interventions. In this study we examine the extent to which malaria parasites conform to the predicted adaptive trade-off between transmission and virulence, as defined by mortality. The majority of natural infections, however, result in sub-lethal virulent effects (e.g. anaemia and are often composed of many strains. Both sub-lethal effects and pathogen population structure have been theoretically shown to have important consequences for virulence evolution. Thus, we additionally examine the relationship between anaemia and transmission in single and mixed clone infections. Results Whereas there was a trade-off between transmission success and virulence as defined by host mortality, contradictory clone-specific patterns occurred when defining virulence by anaemia. A negative relationship between anaemia and transmission success was found for one of the parasite clones, whereas there was no relationship for the other. Notably the two parasite clones also differed in a transmission phenotype (gametocyte sex ratio that has previously been shown to respond adaptively to a changing blood environment. In addition, as predicted by evolutionary theory, mixed infections resulted in increased anaemia. The increased anaemia was, however, not correlated with any discernable parasite trait (e.g. parasite density or with increased transmission. Conclusions We found some evidence supporting the hypothesis that there is an adaptive basis correlating virulence (as defined by host mortality and transmission success in malaria parasites. This confirms the validity of applying evolutionary virulence theory to biomedical

  17. Exploring virulence and immunogenicity in the emerging pathogen Sporothrix brasiliensis.

    Science.gov (United States)

    Della Terra, Paula Portella; Rodrigues, Anderson Messias; Fernandes, Geisa Ferreira; Nishikaku, Angela Satie; Burger, Eva; de Camargo, Zoilo Pires

    2017-08-01

    Sporotrichosis is a polymorphic chronic infection of humans and animals classically acquired after traumatic inoculation with soil and plant material contaminated with Sporothrix spp. propagules. An alternative and successful route of transmission is bites and scratches from diseased cats, through which Sporothrix yeasts are inoculated into mammalian tissue. The development of a murine model of subcutaneous sporotrichosis mimicking the alternative route of transmission is essential to understanding disease pathogenesis and the development of novel therapeutic strategies. To explore the impact of horizontal transmission in animals (e.g., cat-cat) and zoonotic transmission on Sporothrix fitness, the left hind footpads of BALB/c mice were inoculated with 5×106 yeasts (n = 11 S. brasiliensis, n = 2 S. schenckii, or n = 1 S. globosa). Twenty days post-infection, our model reproduced both the pathophysiology and symptomology of sporotrichosis with suppurating subcutaneous nodules that progressed proximally along lymphatic channels. Across the main pathogenic members of the S. schenckii clade, S. brasiliensis was usually more virulent than S. schenckii and S. globosa. However, the virulence in S. brasiliensis was strain-dependent, and we demonstrated that highly virulent isolates disseminate from the left hind footpad to the liver, spleen, kidneys, lungs, heart, and brain of infected animals, inducing significant and chronic weight loss (losing up to 15% of their body weight). The weight loss correlated with host death between 2 and 16 weeks post-infection. Histopathological features included necrosis, suppurative inflammation, and polymorphonuclear and mononuclear inflammatory infiltrates. Immunoblot using specific antisera and homologous exoantigen investigated the humoral response. Antigenic profiles were isolate-specific, supporting the hypothesis that different Sporothrix species can elicit a heterogeneous humoral response over time, but cross reaction was observed

  18. Phytoalexin detoxification genes and gene products: Implication for the evolution of host specific traits for pathogenicity. Final report

    International Nuclear Information System (INIS)

    VanEtten, H.

    1997-01-01

    The overall objectives of this research were to determine which differences among PDA genes were associated with different levels of virulence on pea and to clone and characterize a MAK gene. The authors also proposed to characterize the pisatin detoxifying system in pea pathogens in addition to N. haematococca to assess whether pathogens of a common host had evolved similar pathogenicity genes

  19. Phytoalexin detoxification genes and gene products: Implication for the evolution of host specific traits for pathogenicity. Final report

    Energy Technology Data Exchange (ETDEWEB)

    VanEtten, H.

    1997-06-01

    The overall objectives of this research were to determine which differences among PDA genes were associated with different levels of virulence on pea and to clone and characterize a MAK gene. The authors also proposed to characterize the pisatin detoxifying system in pea pathogens in addition to N. haematococca to assess whether pathogens of a common host had evolved similar pathogenicity genes.

  20. Harbouring public good mutants within a pathogen population can increase both fitness and virulence.

    Science.gov (United States)

    Lindsay, Richard J; Kershaw, Michael J; Pawlowska, Bogna J; Talbot, Nicholas J; Gudelj, Ivana

    2016-12-28

    Existing theory, empirical, clinical and field research all predict that reducing the virulence of individuals within a pathogen population will reduce the overall virulence, rendering disease less severe. Here, we show that this seemingly successful disease management strategy can fail with devastating consequences for infected hosts. We deploy cooperation theory and a novel synthetic system involving the rice blast fungus Magnaporthe oryzae . In vivo infections of rice demonstrate that M. oryzae virulence is enhanced, quite paradoxically, when a public good mutant is present in a population of high-virulence pathogens. We reason that during infection, the fungus engages in multiple cooperative acts to exploit host resources. We establish a multi-trait cooperation model which suggests that the observed failure of the virulence reduction strategy is caused by the interference between different social traits. Multi-trait cooperative interactions are widespread, so we caution against the indiscriminant application of anti-virulence therapy as a disease-management strategy.

  1. The Relationship between Autistic Traits and Social Anxiety, Worry, Obsessive-Compulsive, and Depressive Symptoms: Specific and Non-Specific Mediators in a Student Sample

    Science.gov (United States)

    Liew, Shi Min; Thevaraja, Nishta; Hong, Ryan Y.; Magiati, Iliana

    2015-01-01

    The high prevalence of anxiety symptoms in individuals with autism spectrum disorders has now been well documented. There is also a positive relationship between autistic traits and anxiety symptoms in unselected samples and individuals with anxiety disorders have more autistic traits compared to those without. Less is known, however, regarding…

  2. Density-dependent sex ratio and sex-specific preference for host traits in parasitic bat flies.

    Science.gov (United States)

    Szentiványi, Tamara; Vincze, Orsolya; Estók, Péter

    2017-08-29

    Deviation of sex ratios from unity in wild animal populations has recently been demonstrated to be far more prevalent than previously thought. Ectoparasites are prominent examples of this bias, given that their sex ratios vary from strongly female- to strongly male-biased both among hosts and at the metapopulation level. To date our knowledge is very limited on how and why these biased sex ratios develop. It was suggested that sex ratio and sex-specific aggregation of ectoparasites might be shaped by the ecology, behaviour and physiology of both hosts and their parasites. Here we investigate a highly specialised, hematophagous bat fly species with strong potential to move between hosts, arguably limited inbreeding effects, off-host developmental stages and extended parental care. We collected a total of 796 Nycteribia kolenatii bat flies from 147 individual bats using fumigation and subsequently determined their sex. We report a balanced sex ratio at the metapopulation level and a highly variable sex ratio among infrapopulations ranging from 100% male to 100% female. We show that infrapopulation sex ratio is not random and is highly correlated with infrapopulation size. Sex ratio is highly male biased in small and highly female biased in large infrapopulations. We show that this pattern is most probably the result of sex-specific preference in bat flies for host traits, most likely combined with a higher mobility of males. We demonstrate that female bat flies exert a strong preference for high host body condition and female hosts, while the distribution of males is more even. Our results suggest that locally biased sex ratios can develop due to sex-specific habitat preference of parasites. Moreover, it is apparent that the sex of both hosts and parasites need to be accounted for when a better understanding of host-parasite systems is targeted.

  3. Contributions of acculturation, enculturation, discrimination, and personality traits to social anxiety among Chinese immigrants: A context-specific assessment.

    Science.gov (United States)

    Fang, Ke; Friedlander, Myrna; Pieterse, Alex L

    2016-01-01

    Based on the diathesis-stress model of anxiety, this study examined the contributions of cultural processes, perceived racial discrimination, and personality traits to social anxiety among Chinese immigrants. Further guided by the theory of intergroup anxiety, this study also adopted a context-specific approach to distinguish between participants' experience of social anxiety when interacting with European Americans versus with other Chinese in the United States. This quantitative and ex post facto study used a convenience sample of 140 first-generation Chinese immigrants. Participants were recruited through e-mails from different university and community groups across the United States. The sample includes 55 men and 82 women (3 did not specify) with an average age of 36 years old. Results showed that more social anxiety was reported in the European American context than in the Chinese ethnic context. The full models accounted for almost half the variance in anxiety in each context. Although personality accounted for the most variance, the cultural variables and discrimination contributed 14% of the unique variance in the European American context. Notably, low acculturation, high neuroticism, and low extraversion were unique contributors to social anxiety with European Americans, whereas in the Chinese ethnic context only low extraversion was a unique contributor; more discrimination was uniquely significant in both contexts. The findings suggest a need to contextualize the research and clinical assessment of social anxiety, and have implications for culturally sensitive counseling with immigrants. (c) 2016 APA, all rights reserved).

  4. Specific personality traits and general personality dysfunction as predictors of the presence and severity of personality disorders in a clinical sample

    NARCIS (Netherlands)

    Berghuis, H.; Kamphuis, J.H.; Verheul, R.

    2014-01-01

    This study examined the associations of specific personality traits and general personality dysfunction in relation to the presence and severity of Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]; American Psychiatric Association, 1994) personality disorders in a Dutch

  5. Gender, Previous Knowledge, Personality Traits and Subject-Specific Motivation as Predictors of Students' Math Grade in Upper-Secondary School

    Science.gov (United States)

    Peklaj, Cirila; Podlesek, Anja; Pecjak, Sonja

    2015-01-01

    The aim of the study was to examine the relationships between gender, previous knowledge, different personality traits, subject-specific motivational dimensions and students' math grade in secondary school. A total of 386 first-year students (142 boys and 244 girls) from secondary schools in Slovenia (mean age was 15.7 years) participated in the…

  6. Quantitative genetic analysis of responses to larval food limitation in a polyphenic butterfly indicates environment- and trait-specific effects

    NARCIS (Netherlands)

    Saastamoinen, M.; Brommer, J.E.; Brakefield, P.M.; Zwaan, B.J.

    2013-01-01

    Different components of heritability, including genetic variance (VG), are influenced by environmental conditions. Here, we assessed phenotypic responses of life-history traits to two different developmental conditions, temperature and food limitation. The former represents an environment that

  7. The Acinetobacter baumannii Two-Component System AdeRS Regulates Genes Required for Multidrug Efflux, Biofilm Formation, and Virulence in a Strain-Specific Manner

    Directory of Open Access Journals (Sweden)

    Grace E. Richmond

    2016-04-01

    Full Text Available The opportunistic pathogen Acinetobacter baumannii is able to persist in the environment and is often multidrug resistant (MDR, causing difficulties in the treatment of infections. Here, we show that the two-component system AdeRS, which regulates the production of the AdeABC multidrug resistance efflux pump, is required for the formation of a protective biofilm in an ex vivo porcine mucosal model, which mimics a natural infection of the human epithelium. Interestingly, deletion of adeB impacted only on the ability of strain AYE to form a biofilm on plastic and only on the virulence of strain Singapore 1 for Galleria mellonella. RNA-Seq revealed that loss of AdeRS or AdeB significantly altered the transcriptional landscape, resulting in the changed expression of many genes, notably those associated with antimicrobial resistance and virulence interactions. For example, A. baumannii lacking AdeRS displayed decreased expression of adeABC, pil genes, com genes, and a pgaC-like gene, whereas loss of AdeB resulted in increased expression of pil and com genes and decreased expression of ferric acinetobactin transport system genes. These data define the scope of AdeRS-mediated regulation, show that changes in the production of AdeABC mediate important phenotypes controlled by AdeRS, and suggest that AdeABC is a viable target for antimicrobial drug and antibiofilm discovery.

  8. Age-specific effects of estrogen receptors' polymorphisms on the bone traits in healthy fertile women: the BONTURNO study

    Directory of Open Access Journals (Sweden)

    Pirazzoli Antonella

    2009-04-01

    Full Text Available Abstract Background Skeletal characteristics such as height (Ht, bone mineral density (BMD or bone turnover markers are strongly inherited. Common variants in the genes encoding for estrogen receptor alpha (ESR1 and beta (ESR2 are proposed as candidates for influencing bone phenotypes at the population level. Methods We studied 641 healthy premenopausal women aged 20–50 years (yrs participating into the BONTURNO study. Exclusion criteria were irregular cyclic menses, low trauma fracture, metabolic bone or chronic diseases. Serum C-telopeptide of type I collagen (CTX, osteocalcin (OC, and N-terminal propeptide of type I procollagen (P1NP were measured in all enrolled subjects, who underwent to lumbar spine (LS, total hip (TH and femoral neck (FN BMD evaluation by DXA. Five hundred seventy Caucasian women were genotyped for ESR1 rs2234693 and rs9340799 and ESR2 rs4986938 polymorphisms. Results Although no genotype differences were found in body parameters, subjects with combined ESR1 CCGG plus ESR2 AA-AG genotype were taller than those with opposite genotype (P = 0.044. Moreover, ESR1 rs2234693 genotypes correlated with family history of osteoporosis (FHO and hip fracture (FHF (P When clustered by age, 20–30 yrs old subjects, having at least one ESR1 rs2234693 C allele presented lower LS- (P = 0.008 and TH-BMD (P = 0.047 than TT genotypes. In 41–50 yrs age, lower FN-BMD was associated with ESR2 AA (P = 0.0180 subjects than in those with the opposite genotype. ESR1 rs2234693 and rs9340799 and ESR2 rs4986938 polymorphisms did not correlate with age-adjusted values of OC, CTX and P1NP. Conclusion These findings support the presence of age-specific effects of ESR1 and ESR2 polymorphisms on various skeletal traits in healthy fertile women.

  9. Plasmid-Mediated Antibiotic Resistance and Virulence in Gram-negatives: the Klebsiella pneumoniae Paradigm.

    Science.gov (United States)

    Ramirez, Maria S; Traglia, German M; Lin, David L; Tran, Tung; Tolmasky, Marcelo E

    Plasmids harbor genes coding for specific functions including virulence factors and antibiotic resistance that permit bacteria to survive the hostile environment found in the host and resist treatment. Together with other genetic elements such as integrons and transposons, and using a variety of mechanisms, plasmids participate in the dissemination of these traits resulting in the virtual elimination of barriers among different kinds of bacteria. In this article we review the current information about physiology and role in virulence and antibiotic resistance of plasmids from the gram-negative opportunistic pathogen Klebsiella pneumoniae . This bacterium has acquired multidrug resistance and is the causative agent of serious communityand hospital-acquired infections. It is also included in the recently defined ESKAPE group of bacteria that cause most of US hospital infections.

  10. Comprehensive evaluation of disease- and trait-specific enrichment for eight functional elements among GWAS-identified variants.

    Science.gov (United States)

    Markunas, Christina A; Johnson, Eric O; Hancock, Dana B

    2017-07-01

    Genome-wide association study (GWAS)-identified variants are enriched for functional elements. However, we have limited knowledge of how functional enrichment may differ by disease/trait and tissue type. We tested a broad set of eight functional elements for enrichment among GWAS-identified SNPs (p Enrichment analyses were conducted using logistic regression, with Bonferroni correction. Overall, a significant enrichment was observed for all functional elements, except sequence motifs. Missense SNPs showed the strongest magnitude of enrichment. eQTLs were the only functional element significantly enriched across all diseases/traits. Magnitudes of enrichment were generally similar across diseases/traits, where enrichment was statistically significant. Blood vs. brain tissue effects on enrichment were dependent on disease/trait and functional element (e.g., cardiovascular disease: eQTLs P TissueDifference  = 1.28 × 10 -6 vs. enhancers P TissueDifference  = 0.94). Identifying disease/trait-relevant functional elements and tissue types could provide new insight into the underlying biology, by guiding a priori GWAS analyses (e.g., brain enhancer elements for psychiatric disease) or facilitating post hoc interpretation.

  11. Specificity of herbivore-induced hormonal signaling and defensive traits in five closely related milkweeds (Asclepias spp.).

    Science.gov (United States)

    Agrawal, Anurag A; Hastings, Amy P; Patrick, Eamonn T; Knight, Anna C

    2014-07-01

    Despite the recognition that phytohormonal signaling mediates induced responses to herbivory, we still have little understanding of how such signaling varies among closely related species and may generate herbivore-specific induced responses. We studied closely related milkweeds (Asclepias) to link: 1) plant damage by two specialist chewing herbivores (milkweed leaf beetles Labidomera clivicolis and monarch caterpillars Danaus plexippus); 2) production of the phytohormones jasmonic acid (JA), salicylic acid (SA), and abscisic acid (ABA); 3) induction of defensive cardenolides and latex; and 4) impacts on Danaus caterpillars. We first show that A. syriaca exhibits induced resistance following monarch herbivory (i.e., reduced monarch growth on previously damaged plants), while the defensively dissimilar A. tuberosa does not. We next worked with a broader group of five Asclepias, including these two species, that are highly divergent in defensive traits yet from the same clade. Three of the five species showed herbivore-induced changes in cardenolides, while induced latex was found in four species. Among the phytohormones, JA and ABA showed specific responses (although they generally increased) to insect species and among the plant species. In contrast, SA responses were consistent among plant and herbivore species, showing a decline following herbivore attack. Jasmonic acid showed a positive quantitative relationship only with latex, and this was strongest in plants damaged by D. plexippus. Although phytohormones showed qualitative tradeoffs (i.e., treatments that enhanced JA reduced SA), the few significant individual plant-level correlations among hormones were positive, and these were strongest between JA and ABA in monarch damaged plants. We conclude that: 1) latex exudation is positively associated with endogenous JA levels, even among low-latex species; 2) correlations among milkweed hormones are generally positive, although herbivore damage induces a

  12. Estimating leaf functional traits by inversion of PROSPECT: Assessing leaf dry matter content and specific leaf area in mixed mountainous forest

    Science.gov (United States)

    Ali, Abebe Mohammed; Darvishzadeh, Roshanak; Skidmore, Andrew K.; Duren, Iris van; Heiden, Uta; Heurich, Marco

    2016-03-01

    Assessments of ecosystem functioning rely heavily on quantification of vegetation properties. The search is on for methods that produce reliable and accurate baseline information on plant functional traits. In this study, the inversion of the PROSPECT radiative transfer model was used to estimate two functional leaf traits: leaf dry matter content (LDMC) and specific leaf area (SLA). Inversion of PROSPECT usually aims at quantifying its direct input parameters. This is the first time the technique has been used to indirectly model LDMC and SLA. Biophysical parameters of 137 leaf samples were measured in July 2013 in the Bavarian Forest National Park, Germany. Spectra of the leaf samples were measured using an ASD FieldSpec3 equipped with an integrating sphere. PROSPECT was inverted using a look-up table (LUT) approach. The LUTs were generated with and without using prior information. The effect of incorporating prior information on the retrieval accuracy was studied before and after stratifying the samples into broadleaf and conifer categories. The estimated values were evaluated using R2 and normalized root mean square error (nRMSE). Among the retrieved variables the lowest nRMSE (0.0899) was observed for LDMC. For both traits higher R2 values (0.83 for LDMC and 0.89 for SLA) were discovered in the pooled samples. The use of prior information improved accuracy of the retrieved traits. The strong correlation between the estimated traits and the NIR/SWIR region of the electromagnetic spectrum suggests that these leaf traits could be assessed at canopy level by using remotely sensed data.

  13. Meta-analysis of lipid-traits in Hispanics identifies novel loci, population-specific effects, and tissue-specific enrichment of eQTLs

    NARCIS (Netherlands)

    Below, Jennifer E.; Parra, Esteban J.; Gamazon, Eric R.; Torres, Jason; Krithika, S.; Candille, Sophie; Lu, Yingchang; Manichakul, Ani; Peralta-Romero, Jesus; Duan, Qing; Li, Yun; Morris, Andrew P.; Gottesman, Omri; Bottinger, Erwin; Wang, Xin-Qun; Taylor, Kent D.; Ida Chen, Y.-D.; Rotter, Jerome I.; Rich, Stephen S.; Loos, Ruth J. F.; Tang, Hua; Cox, Nancy J.; Cruz, Miguel; Hanis, Craig L.; Valladares-Salgado, Adan

    2016-01-01

    We performed genome-wide meta-analysis of lipid traits on three samples of Mexican and Mexican American ancestry comprising 4,383 individuals, and followed up significant and highly suggestive associations in three additional Hispanic samples comprising 7,876 individuals. Genome-wide significant

  14. Cognitive enhancement or cognitive cost: trait-specific outcomes of brain stimulation in the case of mathematics anxiety.

    Science.gov (United States)

    Sarkar, Amar; Dowker, Ann; Cohen Kadosh, Roi

    2014-12-10

    The surge in noninvasive brain stimulation studies investigating cognitive enhancement has neglected the effect of interindividual differences, such as traits, on stimulation outcomes. Using the case of mathematics anxiety in a sample of healthy human participants in a placebo-controlled, double-blind, crossover experiment, we show that identical transcranial direct current stimulation (tDCS) exerts opposite behavioral and physiological effects depending on individual trait levels. Mathematics anxiety is the negative emotional response elicited by numerical tasks, impairing mathematical achievement. tDCS was applied to the dorsolateral prefrontal cortex, a frequent target for modulating emotional regulation. It improved reaction times on simple arithmetic decisions and decreased cortisol concentrations (a biomarker of stress) in high mathematics anxiety individuals. In contrast, tDCS impaired reaction times for low mathematics anxiety individuals and prevented a decrease in cortisol concentration compared with sham stimulation. Both groups showed a tDCS-induced side effect-impaired executive control in a flanker task-a cognitive function subserved by the stimulated region. These behavioral and physiological double dissociations have implications for brain stimulation research by highlighting the role of individual traits in experimental findings. Brain stimulation clearly does not produce uniform benefits, even applied in the same configuration during the same tasks, but may interact with traits to produce markedly opposed outcomes. Copyright © 2014 Sarkar et al.

  15. Individual and species-specific traits explain niche size and functional role in spiders as generalist predators.

    Science.gov (United States)

    Sanders, Dirk; Vogel, Esther; Knop, Eva

    2015-01-01

    The function of a predator within a community is greatly based on its trophic niche, that is the number and the strength of feeding links. In generalist predators, which feed on a wide range of prey, the size and position of the trophic niche is likely determined by traits such as hunting mode, the stratum they occur in, their body size and age. We used stable isotope analyses ((13)C and (15)N) to measure the trophic niche size of nine spider species within a forest hedge community and tested for species traits and individual traits that influence stable isotope enrichment, niche size and resource use. The spiders Enoplognatha, Philodromus, Floronia, and Heliophanus had large isotopic niches, which correspond to a more generalistic feeding behaviour. In contrast, Araneus, Metellina and Agelena, as top predators in the system, had rather narrow niches. We found a negative correlation between trophic position and niche size. Differences in trophic position in spiders were explained by body size, hunting modes and stratum, while niche size was influenced by hunting mode. In Philodromus, the size of the trophic niche increased significantly with age. Fitting spiders to functional groups according to their mean body size, hunting mode and their habitat domain resulted in largely separated niches, which indicates that these traits are meaningful for separating functional entities in spiders. Functional groups based on habitat domain (stratum) caught the essential functional differences between the species with species higher up in the vegetation feeding on flying insects and herb and ground species also preying on forest floor decomposers. Interestingly, we found a gradient from large species using a higher habitat domain and having a smaller niche to smaller species foraging closer to the ground and having a larger niche. This shows that even within generalist predators, such as spiders, there is a gradient of specialism that can be predicted by functional traits.

  16. Life history trade-offs and relaxed selection can decrease bacterial virulence in environmental reservoirs.

    Directory of Open Access Journals (Sweden)

    Lauri Mikonranta

    Full Text Available Pathogen virulence is usually thought to evolve in reciprocal selection with the host. While this might be true for obligate pathogens, the life histories of opportunistic pathogens typically alternate between within-host and outside-host environments during the infection-transmission cycle. As a result, opportunistic pathogens are likely to experience conflicting selection pressures across different environments, and this could affect their virulence through life-history trait correlations. We studied these correlations experimentally by exposing an opportunistic bacterial pathogen Serratia marcescens to its natural protist predator Tetrahymena thermophila for 13 weeks, after which we measured changes in bacterial traits related to both anti-predator defence and virulence. We found that anti-predator adaptation (producing predator-resistant biofilm caused a correlative attenuation in virulence. Even though the direct mechanism was not found, reduction in virulence was most clearly connected to a predator-driven loss of a red bacterial pigment, prodigiosin. Moreover, life-history trait evolution was more divergent among replicate populations in the absence of predation, leading also to lowered virulence in some of the 'predator absent' selection lines. Together these findings suggest that the virulence of non-obligatory, opportunistic bacterial pathogens can decrease in environmental reservoirs through life history trade-offs, or random accumulation of mutations that impair virulence traits under relaxed selection.

  17. Multi-virulence-locus sequence typing of Staphylococcus lugdunensis generates results consistent with a clonal population structure and is reliable for epidemiological typing.

    Science.gov (United States)

    Didi, Jennifer; Lemée, Ludovic; Gibert, Laure; Pons, Jean-Louis; Pestel-Caron, Martine

    2014-10-01

    Staphylococcus lugdunensis is an emergent virulent coagulase-negative staphylococcus responsible for severe infections similar to those caused by Staphylococcus aureus. To understand its potentially pathogenic capacity and have further detailed knowledge of the molecular traits of this organism, 93 isolates from various geographic origins were analyzed by multi-virulence-locus sequence typing (MVLST), targeting seven known or putative virulence-associated loci (atlLR2, atlLR3, hlb, isdJ, SLUG_09050, SLUG_16930, and vwbl). The polymorphisms of the putative virulence-associated loci were moderate and comparable to those of the housekeeping genes analyzed by multilocus sequence typing (MLST). However, the MVLST scheme generated 43 virulence types (VTs) compared to 20 sequence types (STs) based on MLST, indicating that MVLST was significantly more discriminating (Simpson's index [D], 0.943). No hypervirulent lineage or cluster specific to carriage strains was defined. The results of multilocus sequence analysis of known and putative virulence-associated loci are consistent with a clonal population structure for S. lugdunensis, suggesting a coevolution of these genes with housekeeping genes. Indeed, the nonsynonymous to synonymous evolutionary substitutions (dN/dS) ratio, the Tajima's D test, and Single-likelihood ancestor counting (SLAC) analysis suggest that all virulence-associated loci were under negative selection, even atlLR2 (AtlL protein) and SLUG_16930 (FbpA homologue), for which the dN/dS ratios were higher. In addition, this analysis of virulence-associated loci allowed us to propose a trilocus sequence typing scheme based on the intragenic regions of atlLR3, isdJ, and SLUG_16930, which is more discriminant than MLST for studying short-term epidemiology and further characterizing the lineages of the rare but highly pathogenic S. lugdunensis. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  18. Addressing the question of disorder-specific risk factors of internet addiction: a comparison of personality traits in patients with addictive behaviors and comorbid internet addiction.

    Science.gov (United States)

    Müller, K W; Koch, A; Dickenhorst, U; Beutel, M E; Duven, E; Wölfling, K

    2013-01-01

    Uncontrolled use of the internet has been reported to affect the lives of some users in a negative way. According to epidemiological studies, about 1% of the general population is showing signs of internet addiction. Since internet addiction is becoming a growing health concern, research on potential risk factors is becoming more important in order to develop strategies for prevention and to adopt therapeutic treatment. Although there are some studies investigating personality traits in internet addiction, most of these studies are based on samples of healthy subjects. In this research project, we compared personality profiles of a sample of patients in different rehabilitation centers. 70 patients with an addiction disorder that additionally met the criteria for internet addiction were compared to 48 patients suffering from alcohol dependence. Besides Big Five personality traits, we also assessed depressive symptoms. It was shown that patients with comorbid internet addiction can be discriminated from other patients by higher neuroticism and lower extraversion as well as lower conscientiousness. After controlling for depressive symptoms, lower conscientiousness especially turned out to be a disorder-specific risk factor. As internet addiction is related to unique patterns of personality traits and can be discriminated from alcohol dependence, treatment approaches are needed that meet the specific requirements of patients with internet addiction.

  19. Addressing the Question of Disorder-Specific Risk Factors of Internet Addiction: A Comparison of Personality Traits in Patients with Addictive Behaviors and Comorbid Internet Addiction

    Directory of Open Access Journals (Sweden)

    K. W. Müller

    2013-01-01

    Full Text Available Uncontrolled use of the internet has been reported to affect the lives of some users in a negative way. According to epidemiological studies, about 1% of the general population is showing signs of internet addiction. Since internet addiction is becoming a growing health concern, research on potential risk factors is becoming more important in order to develop strategies for prevention and to adopt therapeutic treatment. Although there are some studies investigating personality traits in internet addiction, most of these studies are based on samples of healthy subjects. In this research project, we compared personality profiles of a sample of patients in different rehabilitation centers. 70 patients with an addiction disorder that additionally met the criteria for internet addiction were compared to 48 patients suffering from alcohol dependence. Besides Big Five personality traits, we also assessed depressive symptoms. It was shown that patients with comorbid internet addiction can be discriminated from other patients by higher neuroticism and lower extraversion as well as lower conscientiousness. After controlling for depressive symptoms, lower conscientiousness especially turned out to be a disorder-specific risk factor. As internet addiction is related to unique patterns of personality traits and can be discriminated from alcohol dependence, treatment approaches are needed that meet the specific requirements of patients with internet addiction.

  20. Composite selection signals can localize the trait specific genomic regions in multi-breed populations of cattle and sheep

    Science.gov (United States)

    2014-01-01

    Background Discerning the traits evolving under neutral conditions from those traits evolving rapidly because of various selection pressures is a great challenge. We propose a new method, composite selection signals (CSS), which unifies the multiple pieces of selection evidence from the rank distribution of its diverse constituent tests. The extreme CSS scores capture highly differentiated loci and underlying common variants hauling excess haplotype homozygosity in the samples of a target population. Results The data on high-density genotypes were analyzed for evidence of an association with either polledness or double muscling in various cohorts of cattle and sheep. In cattle, extreme CSS scores were found in the candidate regions on autosome BTA-1 and BTA-2, flanking the POLL locus and MSTN gene, for polledness and double muscling, respectively. In sheep, the regions with extreme scores were localized on autosome OAR-2 harbouring the MSTN gene for double muscling and on OAR-10 harbouring the RXFP2 gene for polledness. In comparison to the constituent tests, there was a partial agreement between the signals at the four candidate loci; however, they consistently identified additional genomic regions harbouring no known genes. Persuasively, our list of all the additional significant CSS regions contains genes that have been successfully implicated to secondary phenotypic diversity among several subpopulations in our data. For example, the method identified a strong selection signature for stature in cattle capturing selective sweeps harbouring UQCC-GDF5 and PLAG1-CHCHD7 gene regions on BTA-13 and BTA-14, respectively. Both gene pairs have been previously associated with height in humans, while PLAG1-CHCHD7 has also been reported for stature in cattle. In the additional analysis, CSS identified significant regions harbouring multiple genes for various traits under selection in European cattle including polledness, adaptation, metabolism, growth rate, stature

  1. Effects of resting state condition on reliability, trait specificity, and network connectivity of brain function measured with arterial spin labeled perfusion MRI.

    Science.gov (United States)

    Li, Zhengjun; Vidorreta, Marta; Katchmar, Natalie; Alsop, David C; Wolf, Daniel H; Detre, John A

    2018-06-01

    Resting state fMRI (rs-fMRI) provides imaging biomarkers of task-independent brain function that can be associated with clinical variables or modulated by interventions such as behavioral training or pharmacological manipulations. These biomarkers include time-averaged regional brain function as manifested by regional cerebral blood flow (CBF) measured using arterial spin labeled (ASL) perfusion MRI and correlated temporal fluctuations of function across brain networks with either ASL or blood oxygenation level dependent (BOLD) fMRI. Resting-state studies are typically carried out using just one of several prescribed state conditions such as eyes closed (EC), eyes open (EO), or visual fixation on a cross-hair (FIX), which may affect the reliability and specificity of rs-fMRI. In this study, we collected test-retest ASL MRI data during 4 resting-state task conditions: EC, EO, FIX and PVT (low-frequency psychomotor vigilance task), and examined the effects of these task conditions on reliability and reproducibility as well as trait specificity of regional brain function. We also acquired resting-state BOLD fMRI under FIX and compared the network connectivity reliabilities between the four ASL conditions and the BOLD FIX condition. For resting-state ASL data, EC provided the highest CBF reliability, reproducibility, trait specificity, and network connectivity reliability, followed by EO, while FIX was lowest on all of these measures. PVT demonstrated lower CBF reliability, reproducibility and trait specificity than EO and EC. Overall network connectivity reliability was comparable between ASL and BOLD. Our findings confirm ASL CBF as a reliable, stable, and consistent measure of resting-state regional brain function and support the use of EC or EO over FIX and PVT as the resting-state condition. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Virulence evolution at the front line of spreading epidemics.

    Science.gov (United States)

    Griette, Quentin; Raoul, Gaël; Gandon, Sylvain

    2015-11-01

    Understanding and predicting the spatial spread of emerging pathogens is a major challenge for the public health management of infectious diseases. Theoretical epidemiology shows that the speed of an epidemic is governed by the life-history characteristics of the pathogen and its ability to disperse. Rapid evolution of these traits during the invasion may thus affect the speed of epidemics. Here we study the influence of virulence evolution on the spatial spread of an epidemic. At the edge of the invasion front, we show that more virulent and transmissible genotypes are expected to win the competition with other pathogens. Behind the front line, however, more prudent exploitation strategies outcompete virulent pathogens. Crucially, even when the presence of the virulent mutant is limited to the edge of the front, the invasion speed can be dramatically altered by pathogen evolution. We support our analysis with individual-based simulations and we discuss the additional effects of demographic stochasticity taking place at the front line on virulence evolution. We confirm that an increase of virulence can occur at the front, but only if the carrying capacity of the invading pathogen is large enough. These results are discussed in the light of recent empirical studies examining virulence evolution at the edge of spreading epidemics. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  3. Toxin-independent virulence of Bacillus anthracis in rabbits.

    Directory of Open Access Journals (Sweden)

    Haim Levy

    Full Text Available The accepted paradigm states that anthrax is both an invasive and toxinogenic disease and that the toxins play a major role in pathogenicity. In the guinea pig (GP model we have previously shown that deletion of all three toxin components results in a relatively moderate attenuation in virulence, indicating that B. anthracis possesses an additional toxin-independent virulence mechanism. To characterize this toxin-independent mechanism in anthrax disease, we developed a new rabbit model by intravenous injection (IV of B. anthracis encapsulated vegetative cells, artificially creating bacteremia. Using this model we were able to demonstrate that also in rabbits, B. anthracis mutants lacking the toxins are capable of killing the host within 24 hours. This virulent trait depends on the activity of AtxA in the presence of pXO2, as, in the absence of the toxin genes, deletion of either component abolishes virulence. Furthermore, this IV virulence depends mainly on AtxA rather than the whole pXO1. A similar pattern was shown in the GP model using subcutaneous (SC administration of spores of the mutant strains, demonstrating the generality of the phenomenon. The virulent strains showed higher bacteremia levels and more efficient tissue dissemination; however our interpretation is that tissue dissemination per se is not the main determinant of virulence whose exact nature requires further elucidation.

  4. "Are we there yet?": Deciding when one has demonstrated specific genetic causation in complex diseases and quantitative traits.

    Science.gov (United States)

    Page, Grier P; George, Varghese; Go, Rodney C; Page, Patricia Z; Allison, David B

    2003-10-01

    Although mathematical relationships can be proven by deductive logic, biological relationships can only be inferred from empirical observations. This is a distinct disadvantage for those of us who strive to identify the genes involved in complex diseases and quantitative traits. If causation cannot be proven, however, what does constitute sufficient evidence for causation? The philosopher Karl Popper said, "Our belief in a hypothesis can have no stronger basis than our repeated unsuccessful critical attempts to refute it." We believe that to establish causation, as scientists, we must make a serious attempt to refute our own hypotheses and to eliminate all known sources of bias before association becomes causation. In addition, we suggest that investigators must provide sufficient data and evidence of their unsuccessful efforts to find any confounding biases. In this editorial, we discuss what "causation" means in the context of complex diseases and quantitative traits, and we suggest guidelines for steps that may be taken to address possible confounders of association before polymorphisms may be called "causative."

  5. Sample collection of virulent and non-virulent B. anthracis and Y. pestis for bioforensics analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hong-geller, Elizabeth [Los Alamos National Laboratory; Valdez, Yolanda E [Los Alamos National Laboratory; Shou, Yulin [Los Alamos National Laboratory; Yoshida, Thomas M [Los Alamos National Laboratory; Marrone, Babetta L [Los Alamos National Laboratory; Dunbar, John [Los Alamos National Laboratory

    2009-01-01

    Validated sample collection methods are needed for recovery of microbial evidence in the event of accidental or intentional release of biological agents into the environment. To address this need, we evaluated the sample recovery efficiencies of two collection methods -- swabs and wipes -- for both non-virulent and virulent strains of B. anthracis and Y. pestis from four types of non-porous surfaces: two hydrophilic surfaces, stainless steel and glass, and two hydrophobic surfaces, vinyl and plastic. Sample recovery was quantified using Real-time qPCR to assay for intact DNA signatures. We found no consistent difference in collection efficiency between swabs or wipes. Furthermore, collection efficiency was more surface-dependent for virulent strains than non-virulent strains. For the two non-virulent strains, B. anthracis Sterne and Y. pestis A1122, collection efficiency was approximately 100% and 1 %, respectively, from all four surfaces. In contrast, recovery of B. anthracis Ames spores and Y. pestis C092 from vinyl and plastic was generally lower compared to collection from glass or stainless steel, suggesting that surface hydrophobicity may playa role in the strength of pathogen adhesion. The surface-dependent collection efficiencies observed with the virulent strains may arise from strain-specific expression of capsular material or other cell surface receptors that alter cell adhesion to specific surfaces. These findings contribute to validation of standard bioforensics procedures and emphasize the importance of specific strain and surface interactions in pathogen detection.

  6. A tool based on Ligation Detection Reaction-Universal Array (LDR-UA) for the characterization of VTEC by identification of virulence-associated and serogroup-specific genes.

    Science.gov (United States)

    Lauri, Andrea; Castiglioni, Bianca; Morabito, Stefano; Tozzoli, Rosangela; Consolandi, Clarissa; Mariani, Paola

    2011-02-01

    Verocytoxigenic Escherichia coli (VTEC) are zoonotic pathogens whose natural reservoir is represented by ruminants, particularly cattle. Infections are mainly acquired by consumption of undercooked contaminated food of animal origin, contact with infected animals and contaminated environment. VTEC O157 is the most frequently isolated serogroup from cases of human disease, however, other VTEC serogroups, such as O26, O111, O145 and O103, are increasingly reported as causing Hemolytic Uremic Syndrome (HUS) worldwide. The identification of VTEC is troublesome, hindering the development of effective prevention strategies. In fact, VTEC are morphologically indistinguishable from harmless E. coli and their pathogenic potential is not strictly dependent on the serogroup, but relies on the presence of a collection of virulence genes. We developed a diagnostic tool for VTEC based on the Ligation Detection Reaction coupled to Universal Array (LDR-UA) for the simultaneous identification of virulence factors and serogroup-associated genes. The method includes the investigation of 40 sites located in 13 fragments from 12 genes (sodCF1/F2, adfO, terB, ehxA, eae, vtx1, vtx2, ihp1, wzx, wbdI, rfbE, dnaK) and was evaluated by performing a trial on a collection of 67 E. coli strains, both VTEC and VT-negative E. coli, as well as on 25 isolates belonging to other related species. Results of this study showed that the LDR-UA technique was specific in identifying the target microorganism. Moreover, due to its higher throughput, the LDR-UA can be a valid and cheaper alternative to real time PCR-based (rt-PCR) methods for VTEC identification. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Trait specific consequences of fast and slow inbreeding: lessonsfrom captive populations of Drosophila melanogaster

    DEFF Research Database (Denmark)

    Mikkelsen, Karina Aarup; Loeschcke, Volker; Kristensen, Torsten Nygaard

    2010-01-01

    or 2 generations. These inbred lines were contrasted to non-inbred control lines. We investigated the effect of inbreeding and inbreeding rate in traits associated with fitness including heat, cold and desiccation stress resistance, egg-to-adult viability, development time, productivity, metabolic rate......The increased homozygosity due to inbreeding leads to expression of deleterious recessive alleles, which may cause inbreeding depression in small populations. The severity of inbreeding depression has been suggested to depend on the rate of inbreeding, with slower inbreeding being more effective...... and heat stress conditions. Reduced viability and increased developmental time were observed at stressful temperatures and inbreeding depression was on average more severe at stressful compared to benign temperatures...

  8. Genome-Wide Association Study Identifies Two Novel Loci with Sex-Specific Effects for Type 2 Diabetes Mellitus and Glycemic Traits in a Korean Population

    Directory of Open Access Journals (Sweden)

    Min Jin Go

    2014-10-01

    Full Text Available BackgroundUntil recently, genome-wide association study (GWAS-based findings have provided a substantial genetic contribution to type 2 diabetes mellitus (T2DM or related glycemic traits. However, identification of allelic heterogeneity and population-specific genetic variants under consideration of potential confounding factors will be very valuable for clinical applicability. To identify novel susceptibility loci for T2DM and glycemic traits, we performed a two-stage genetic association study in a Korean population.MethodsWe performed a logistic analysis for T2DM, and the first discovery GWAS was analyzed for 1,042 cases and 2,943 controls recruited from a population-based cohort (KARE, n=8,842. The second stage, de novo replication analysis, was performed in 1,216 cases and 1,352 controls selected from an independent population-based cohort (Health 2, n=8,500. A multiple linear regression analysis for glycemic traits was further performed in a total of 14,232 nondiabetic individuals consisting of 7,696 GWAS and 6,536 replication study participants. A meta-analysis was performed on the combined results using effect size and standard errors estimated for stage 1 and 2, respectively.ResultsA combined meta-analysis for T2DM identified two new (rs11065756 and rs2074356 loci reaching genome-wide significance in CCDC63 and C12orf51 on the 12q24 region. In addition, these variants were significantly associated with fasting plasma glucose and homeostasis model assessment of β-cell function. Interestingly, two independent single nucleotide polymorphisms were associated with sex-specific stratification in this study.ConclusionOur study showed a strong association between T2DM and glycemic traits. We further observed that two novel loci with multiple diverse effects were highly specific to males. Taken together, these findings may provide additional insights into the clinical assessment or subclassification of disease risk in a Korean population.

  9. The Utility of General and School-Specific Personality Traits and an Examination of Their Relationship over Time

    Science.gov (United States)

    Eschleman, Kevin J.; Burns, Gary

    2012-01-01

    A university student sample was used to compare school-specific (i.e., personality at school) and general personality (i.e., personality across all life domains) over eight weeks. School-specific and general personality incrementally predicted change in school-specific criteria (i.e., school satisfaction and school citizenship behaviors). Less…

  10. Genetics of Pathogen Fitness: Correlations with Virulence and Effects of Host Genotype

    Science.gov (United States)

    In plant pathology, a large body of work has focused on changes in virulence, the traits allowing infection of otherwise resistant hosts, while relatively few studies have examined changes in quantitative fitness traits, those affecting the reproductive success of the pathogen after infection has oc...

  11. Potential drivers of virulence evolution in aquaculture

    Science.gov (United States)

    Kennedy, David A.; Kurath, Gael; Brito, Ilana L.; Purcell, Maureen K.; Read, Andrew F.; Winton, James R.; Wargo, Andrew R.

    2016-01-01

    Infectious diseases are economically detrimental to aquaculture, and with continued expansion and intensification of aquaculture, the importance of managing infectious diseases will likely increase in the future. Here, we use evolution of virulence theory, along with examples, to identify aquaculture practices that might lead to the evolution of increased pathogen virulence. We identify eight practices common in aquaculture that theory predicts may favor evolution toward higher pathogen virulence. Four are related to intensive aquaculture operations, and four others are related specifically to infectious disease control. Our intention is to make aquaculture managers aware of these risks, such that with increased vigilance, they might be able to detect and prevent the emergence and spread of increasingly troublesome pathogen strains in the future.

  12. Trait specific expression profiling of salt stress responsive genes in diverse rice genotypes as determined by modified Significance Analysis of Microarrays

    Directory of Open Access Journals (Sweden)

    Mohammad Rashed Hossain

    2016-05-01

    Full Text Available Stress responsive gene expression is commonly profiled in a comparative manner involving different stress conditions or genotypes with contrasting reputation of tolerance/resistance. In contrast, this research exploited a wide natural variation in terms of taxonomy, origin and salt sensitivity in eight genotypes of rice to identify the trait specific patterns of gene expression under salt stress. Genome wide transcptomic responses were interrogated by the weighted continuous morpho-physiological trait responses using modified Significance Analysis of Microarrays. More number of genes was found to be differentially expressed under salt stressed compared to that of under unstressed conditions. Higher numbers of genes were observed to be differentially expressed for the traits shoot Na+/K+, shoot Na+, root K+, biomass and shoot Cl-, respectively. The results identified around sixty genes to be involved in Na+, K+ and anion homeostasis, transport and transmembrane activity under stressed conditions. Gene Ontology (GO enrichment analysis identified 1.36% (578 genes of the entire transcriptome to be involved in the major molecular functions such as signal transduction (>150 genes, transcription factor (81 genes and translation factor activity (62 genes etc. under salt stress. Chromosomal mapping of the genes suggests that majority of the genes are located on chromosomes 1, 2, 3, 6 & 7. The gene network analysis showed that the transcription factors and translation initiation factors formed the major gene networks and are mostly active in nucleus, cytoplasm and mitochondria whereas the membrane and vesicle bound proteins formed a secondary network active in plasma membrane and vacuoles. The novel genes and the genes with unknown functions thus identified provide picture of a synergistic salinity response representing the potentially fundamental mechanisms that are active in the wide natural genetic background of rice and will be of greater use once

  13. The Influence of Culture-Specific Personality Traits on the Development of Delinquency in At-Risk Youth.

    Science.gov (United States)

    Tong, Tat Seng; Ku, Lisbeth; Zaroff, Charles Mark

    2016-04-01

    The association between culture-specific personality variables and family factors, and juvenile delinquency, was assessed in a sample of 402 adolescents of Chinese ethnicity between 12 and 17 years of age (Mage = 15.13, SD = 1.41; 135 girls), a subgroup of whom were considered at risk for juvenile delinquency owing to addictive behavior tendencies. Culture-specific personality variables were assessed using the Chinese Personality Assessment Inventory-Adolescent version Interpersonal Relatedness factor. The General Function subscale of the Chinese version of the Family Assessment Device was utilized to assess the influence of perceived levels of family functioning. Both culture-specific personality variables and non-culture-specific familial factors were significantly and negatively associated with self-reported juvenile delinquency (p delinquency (p < .001). Implications of the current results are discussed. © The Author(s) 2014.

  14. Transient virulence of emerging pathogens.

    Science.gov (United States)

    Bolker, Benjamin M; Nanda, Arjun; Shah, Dharmini

    2010-05-06

    Should emerging pathogens be unusually virulent? If so, why? Existing theories of virulence evolution based on a tradeoff between high transmission rates and long infectious periods imply that epidemic growth conditions will select for higher virulence, possibly leading to a transient peak in virulence near the beginning of an epidemic. This transient selection could lead to high virulence in emerging pathogens. Using a simple model of the epidemiological and evolutionary dynamics of emerging pathogens, along with rough estimates of parameters for pathogens such as severe acute respiratory syndrome, West Nile virus and myxomatosis, we estimated the potential magnitude and timing of such transient virulence peaks. Pathogens that are moderately evolvable, highly transmissible, and highly virulent at equilibrium could briefly double their virulence during an epidemic; thus, epidemic-phase selection could contribute significantly to the virulence of emerging pathogens. In order to further assess the potential significance of this mechanism, we bring together data from the literature for the shapes of tradeoff curves for several pathogens (myxomatosis, HIV, and a parasite of Daphnia) and the level of genetic variation for virulence for one (myxomatosis). We discuss the need for better data on tradeoff curves and genetic variance in order to evaluate the plausibility of various scenarios of virulence evolution.

  15. Dimerization Is Not a Determining Factor for Functional High Affinity Human Plasminogen Binding by the Group A Streptococcal Virulence Factor PAM and Is Mediated by Specific Residues within the PAM a1a2 Domain*

    Science.gov (United States)

    Bhattacharya, Sarbani; Liang, Zhong; Quek, Adam J.; Ploplis, Victoria A.; Law, Ruby; Castellino, Francis J.

    2014-01-01

    A emm53 subclass of Group A Streptococcus pyogenes (GAS) interacts tightly with human plasma plasminogen (hPg) and plasmin (hPm) via the kringle 2 (K2hPg) domain of hPg/hPm and the N-terminal a1a2 regions of a GAS coiled-coil M-like protein (PAM). Previous studies have shown that a monomeric PAM fragment, VEK30 (residues 97–125 + Tyr), interacted specifically with isolated K2hPg. However, the binding strength of VEK30 (KD = 56 nm) was ∼60-fold weaker than that of full-length dimeric PAM (KD = 1 nm). To assess whether this attenuated binding was due to the inability of VEK30 to dimerize, we defined the minimal length of PAM required to dimerize using a series of peptides with additional PAM residues placed at the NH2 and COOH termini of VEK30. VEK64 (PAM residues 83–145 + Tyr) was found to be the smallest peptide that adopted an α-helical dimer, and was bound to K2hPg with nearly the same affinity as PAM (KD = 1–2 nm). However, addition of two PAM residues (Arg126-His127) to the COOH terminus of VEK30 (VEK32) maintained a monomeric peptidic structure, but exhibited similar K2hPg binding affinity as full-length dimeric PAM. We identified five residues in a1a2 (Arg113, His114, Glu116, Arg126, His127), mutation of which reduced PAM binding affinity for K2hPg by ∼1000-fold. Replacement of these critical residues by Ala in the GAS genome resulted in reduced virulence, similar to the effects of inactivating the PAM gene entirely. We conclude that rather than dimerization of PAM, the five key residues in the binding domain of PAM are essential to mediate the high affinity interaction with hPg, leading to increased GAS virulence. PMID:24962580

  16. Dimerization is not a determining factor for functional high affinity human plasminogen binding by the group A streptococcal virulence factor PAM and is mediated by specific residues within the PAM a1a2 domain.

    Science.gov (United States)

    Bhattacharya, Sarbani; Liang, Zhong; Quek, Adam J; Ploplis, Victoria A; Law, Ruby; Castellino, Francis J

    2014-08-01

    A emm53 subclass of Group A Streptococcus pyogenes (GAS) interacts tightly with human plasma plasminogen (hPg) and plasmin (hPm) via the kringle 2 (K2hPg) domain of hPg/hPm and the N-terminal a1a2 regions of a GAS coiled-coil M-like protein (PAM). Previous studies have shown that a monomeric PAM fragment, VEK30 (residues 97-125 + Tyr), interacted specifically with isolated K2hPg. However, the binding strength of VEK30 (KD = 56 nm) was ∼60-fold weaker than that of full-length dimeric PAM (KD = 1 nm). To assess whether this attenuated binding was due to the inability of VEK30 to dimerize, we defined the minimal length of PAM required to dimerize using a series of peptides with additional PAM residues placed at the NH2 and COOH termini of VEK30. VEK64 (PAM residues 83-145 + Tyr) was found to be the smallest peptide that adopted an α-helical dimer, and was bound to K2hPg with nearly the same affinity as PAM (KD = 1-2 nm). However, addition of two PAM residues (Arg(126)-His(127)) to the COOH terminus of VEK30 (VEK32) maintained a monomeric peptidic structure, but exhibited similar K2hPg binding affinity as full-length dimeric PAM. We identified five residues in a1a2 (Arg(113), His(114), Glu(116), Arg(126), His(127)), mutation of which reduced PAM binding affinity for K2hPg by ∼ 1000-fold. Replacement of these critical residues by Ala in the GAS genome resulted in reduced virulence, similar to the effects of inactivating the PAM gene entirely. We conclude that rather than dimerization of PAM, the five key residues in the binding domain of PAM are essential to mediate the high affinity interaction with hPg, leading to increased GAS virulence. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Virulence patterns in a murine sepsis model of ST131 Escherichia coli clinical isolates belonging to serotypes O25b:H4 and O16:H5 are associated to specific virotypes.

    Directory of Open Access Journals (Sweden)

    Azucena Mora

    Full Text Available Escherichia coli sequence type (ST131 is an emerging disseminated public health threat implicated in multidrug-resistant extraintestinal infections worldwide. Although the majority of ST131 isolates belong to O25b:H4 serotype, new variants with different serotypes, STs using the discriminative multilocus sequence typing scheme of Pasteur Institute, and virulence-gene profiles (virotypes have been reported with unknown implications on the pattern of spread, persistence and virulence. The aim of the present study was to compare virulence in a mouse subcutaneous sepsis model of representative ST131 clinical isolates belonging to 2 serotypes (O25b:H4, O16:H5 and nine virotypes and subtypes (A, B, C, D1, D2, D3, D4, D5 and E. Fourteen out of the 23 ST131 isolates tested (61% killed 90 to 100% of mice challenged, and 18 of 23 (78% at least 50%. Interestingly, different virulence patterns in association with virotypes were observed, from highly rapid lethality (death in less than 24 h to low final lethality (death at 7 days but with presence of an acute inflammation. This is the first study to assess virulence of ST131 isolates belonging to serotype O16:H5, which exhibited virotype C. In spite of their low virulence-gene score, O16:H5 isolates did not show significant differences in final lethality compared with highly virulent O25b:H4 isolates of virotypes A, B and C, but killed mice less rapidly. Significant differences were found, however, between virotypes A, B, C (final lethality ≥80% of mice challenged and virotypes D, E. Particularly unexpected was the low lethality of the newly assigned virotype E taking into account that it exhibited high virulence-gene score, and the same clonotype H30 as highly virulent O25b:H4 isolates of virotypes A, B and C. In vivo virulence diversity reported in this study would reflect the genetic variability within ST131 clonal group evidenced by molecular typing.

  18. Trans-ethnic fine-mapping of lipid loci identifies population-specific signals and allelic heterogeneity that increases the trait variance explained.

    Directory of Open Access Journals (Sweden)

    Ying Wu

    2013-03-01

    Full Text Available Genome-wide association studies (GWAS have identified ~100 loci associated with blood lipid levels, but much of the trait heritability remains unexplained, and at most loci the identities of the trait-influencing variants remain unknown. We conducted a trans-ethnic fine-mapping study at 18, 22, and 18 GWAS loci on the Metabochip for their association with triglycerides (TG, high-density lipoprotein cholesterol (HDL-C, and low-density lipoprotein cholesterol (LDL-C, respectively, in individuals of African American (n = 6,832, East Asian (n = 9,449, and European (n = 10,829 ancestry. We aimed to identify the variants with strongest association at each locus, identify additional and population-specific signals, refine association signals, and assess the relative significance of previously described functional variants. Among the 58 loci, 33 exhibited evidence of association at P<1 × 10(-4 in at least one ancestry group. Sequential conditional analyses revealed that ten, nine, and four loci in African Americans, Europeans, and East Asians, respectively, exhibited two or more signals. At these loci, accounting for all signals led to a 1.3- to 1.8-fold increase in the explained phenotypic variance compared to the strongest signals. Distinct signals across ancestry groups were identified at PCSK9 and APOA5. Trans-ethnic analyses narrowed the signals to smaller sets of variants at GCKR, PPP1R3B, ABO, LCAT, and ABCA1. Of 27 variants reported previously to have functional effects, 74% exhibited the strongest association at the respective signal. In conclusion, trans-ethnic high-density genotyping and analysis confirm the presence of allelic heterogeneity, allow the identification of population-specific variants, and limit the number of candidate SNPs for functional studies.

  19. Prevalence, clinical profile, iron status, and subject-specific traits for excessive erythrocytosis in andean adults living permanently at 3,825 meters above sea level.

    Science.gov (United States)

    De Ferrari, Aldo; Miranda, J Jaime; Gilman, Robert H; Dávila-Román, Victor G; León-Velarde, Fabiola; Rivera-Ch, Maria; Huicho, Luis; Bernabé-Ortiz, Antonio; Wise, Robert A; Checkley, William

    2014-11-01

    Excessive erythrocytosis (EE) is a prevalent condition in populations living at high altitudes (> 2,500 m above sea level). Few large population-based studies have explored the association between EE and multiple subject-specific traits including oxygen saturation, iron status indicators, and pulmonary function. We enrolled a sex-stratified and age-stratified sample of 1,065 high-altitude residents aged ≥ 35 years from Puno, Peru (3,825 m above sea level) and conducted a standardized questionnaire and physical examination that included spirometry, pulse oximetry, and a blood sample for multiple clinical markers. Our primary objectives were to estimate the prevalence of EE, characterize the clinical profile and iron status indicators of subjects with EE, and describe subject-specific traits associated with EE. Overall prevalence of EE was 4.5% (95% CI, 3.3%-6.0%). Oxygen saturation was significantly lower among EE than non-EE group subjects (85.3% vs 90.1%, P .09 for all values). In multivariable logistic regression, we found that age ≥ 65 years (OR = 2.45, 95% CI, 1.16-5.09), male sex (3.86, 1.78-9.08), having metabolic syndrome (2.66, 1.27-5.75) or being overweight (5.20, 1.95-16.77), pulse oximetry overweight (26.7%), followed by male sex (21.5%), pulse oximetry overweight or having metabolic syndrome were associated with an important fraction of cases in our study population.

  20. Freshwater Biological Traits Database (Traits)

    Science.gov (United States)

    The traits database was compiled for a project on climate change effects on river and stream ecosystems. The traits data, gathered from multiple sources, focused on information published or otherwise well-documented by trustworthy sources.

  1. Associations between pathogen-specific cases of subclinical mastitis and milk yield, quality, protein composition, and cheese-making traits in dairy cows.

    Science.gov (United States)

    Bobbo, T; Ruegg, P L; Stocco, G; Fiore, E; Gianesella, M; Morgante, M; Pasotto, D; Bittante, G; Cecchinato, A

    2017-06-01

    The aim of this study was to investigate associations between pathogen-specific cases of subclinical mastitis and milk yield, quality, protein composition, and cheese-making traits. Forty-one multibreed herds were selected for the study, and composite milk samples were collected from 1,508 cows belonging to 3 specialized dairy breeds (Holstein Friesian, Brown Swiss, and Jersey) and 3 dual-purpose breeds of Alpine origin (Simmental, Rendena, and Grey Alpine). Milk composition [i.e., fat, protein, casein, lactose, pH, urea, and somatic cell count (SCC)] was analyzed, and separation of protein fractions was performed by reversed-phase high performance liquid chromatography. Eleven coagulation traits were measured: 5 traditional milk coagulation properties [time from rennet addition to milk gelation (RCT, min), curd-firming rate as the time to a curd firmness (CF) of 20 mm (k 20 , min), and CF at 30, 45, and 60 min from rennet addition (a 30 , a 45 , and a 60 , mm)], and 6 new curd firming and syneresis traits [potential asymptotical CF at an infinite time (CF P , mm), curd-firming instant rate constant (k CF , % × min -1 ), curd syneresis instant rate constant (k SR , % × min -1 ), modeled RCT (RCT eq , min), maximum CF value (CF max, mm), and time at CF max (t max , min)]. We also measured 3 cheese yield traits, expressing the weights of total fresh curd (%CY CURD ), dry matter (%CY SOLIDS ), and water (%CY WATER ) in the curd as percentages of the weight of the processed milk, and 4 nutrient recovery traits (REC PROTEIN , REC FAT , REC SOLIDS , and REC ENERGY ), representing the percentage ratio between each nutrient in the curd and milk. Milk samples with SCC > 100,000 cells/mL were subjected to bacteriological examination. All samples were divided into 7 clusters of udder health (UH) status: healthy (cows with milk SCC culture-negative samples with low, medium, or high SCC; and culture-positive samples divided into contagious, environmental, and opportunistic

  2. The effect of mutation on Rhodococcus equi virulence plasmid gene expression and mouse virulence.

    Science.gov (United States)

    Ren, Jun; Prescott, John F

    2004-11-15

    An 81 kb virulence plasmid containing a pathogenicity island (PI) plays a crucial role in the pathogenesis of Rhodococcus equi pneumonia in foals but its specific function in virulence and regulation of plasmid-encoded virulence genes is unclear. Using a LacZ selection marker developed for R. equi in this study, in combination with an apramycin resistance gene, an efficient two-stage homologous recombination targeted gene mutation procedure was used to mutate three virulence plasmid genes, a LysR regulatory gene homologue (ORF4), a ResD-like two-component response regulator homologue (ORF8), and a gene (ORF10) of unknown function that is highly expressed by R. equi inside macrophages, as well as the chromosomal gene operon, phoPR. Virulence testing by liver clearance after intravenous injection in mice showed that the ORF4 and ORF8 mutants were fully attenuated, that the phoPR mutant was hypervirulent, and that virulence of the ORF10 mutant remained unchanged. A virulence plasmid DNA microarray was used to compare the plasmid gene expression profile of each of the four gene-targeted mutants against the parental R. equi strain. Changes were limited to PI genes and gene induction was observed for all mutants, suggesting that expression of virulence plasmid genes is dominated by a negative regulatory network. The finding of attenuation of ORF4 and ORF8 mutants despite enhanced transcription of vapA suggests that factors other than VapA are important for full expression of virulence. ORF1, a putative Lsr antigen gene, was strongly and similarly induced in all mutants, implying a common regulatory pathway affecting this gene for all four mutated genes. ORF8 is apparently the centre of this common pathway. Two distinct highly correlated gene induction patterns were observed, that of the ORF4 and ORF8 mutants, and that of the ORF10 and phoPR mutants. The gene induction pattern distinguishing these two groups paralleled their virulence in mice.

  3. Inter-species protein trafficking endows dodder (Cuscuta pentagona) with a host-specific herbicide-tolerant trait.

    Science.gov (United States)

    Jiang, Linjian; Qu, Feng; Li, Zhaohu; Doohan, Douglas

    2013-06-01

    · Besides photosynthates, dodder (Cuscuta spp.) acquires phloem-mobile proteins from host; however, whether this could mediate inter-species phenotype transfer was not demonstrated. Specifically, we test whether phosphinothricin acetyl transferase (PAT) that confers host plant glufosinate herbicide tolerance traffics and functions inter-specifically. · Dodder tendrils excised from hosts can grow in vitro for weeks or resume in vivo by parasitizing new hosts. The level of PAT in in vivo and in vitro dodder tendrils was quantified by enzyme-linked immunosorbent assay. The glufosinate sensitivity was examined by dipping the distal end of in vivo and in vitro tendrils, growing on or excised from LibertyLink (LL; PAT-transgenic and glufosinate tolerant) and conventional (CN; glufosinate sensitive) soybean hosts, into glufosinate solutions for 5 s. After in vitro tendrils excised from LL hosts reparasitized new CN and LL hosts, the PAT level and the glufosinate sensitivity were also examined. · When growing on LL host, dodder tolerated glufosinate and contained PAT at a level of 0.3% of that encountered in LL soybean leaf. After PAT was largely degraded in dodders, they became glufosinate sensitive. PAT mRNA was not detected by reverse transcription PCR in dodders. · In conclusion, the results indicated that PAT inter-species trafficking confers dodder glufosinate tolerance. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  4. The substance use risk profile scale: a scale measuring traits linked to reinforcement-specific substance use profiles.

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    Woicik, P.A.; Stewart, S.H.; Pihl, R.O.; Conrod, P.J.

    2009-12-01

    The Substance Use Risk Profile Scale (SURPS) is based on a model of personality risk for substance abuse in which four personality dimensions (hopelessness, anxiety sensitivity, impulsivity, and sensation seeking) are hypothesized to differentially relate to specific patterns of substance use. The current series of studies is a preliminary exploration of the psychometric properties of the SURPS in two populations (undergraduate and high school students). In study 1, an analysis of the internal structure of two versions of the SURPS shows that the abbreviated version best reflects the 4-factor structure. Concurrent, discriminant, and incremental validity of the SURPS is supported by convergent/divergent relationships between the SURPS subscales and other theoretically relevant personality and drug use criterion measures. In Study 2, the factorial structure of the SURPS is confirmed and evidence is provided for its test-retest reliability and validity with respect to measuring personality vulnerability to reinforcement-specific substance use patterns. In Study 3, the SURPS was administered in a more youthful population to test its sensitivity in identifying younger problematic drinkers. The results from the current series of studies demonstrate support for the reliability and construct validity of the SURPS, and suggest that four personality dimensions may be linked to substance-related behavior through different reinforcement processes. This brief assessment tool may have important implications for clinicians and future research.

  5. The endocrine stress response is linked to one specific locus on chromosome 3 in a mouse model based on extremes in trait anxiety

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    Gonik Mariya

    2012-10-01

    Full Text Available Abstract Background The hypothalamic-pituitary-adrenal (HPA axis is essential to control physiological stress responses in mammals. Its dysfunction is related to several mental disorders, including anxiety and depression. The aim of this study was to identify genetic loci underlying the endocrine regulation of the HPA axis. Method High (HAB and low (LAB anxiety-related behaviour mice were established by selective inbreeding of outbred CD-1 mice to model extremes in trait anxiety. Additionally, HAB vs. LAB mice exhibit comorbid characteristics including a differential corticosterone response upon stress exposure. We crossbred HAB and LAB lines to create F1 and F2 offspring. To identify the contribution of the endocrine phenotypes to the total phenotypic variance, we examined multiple behavioural paradigms together with corticosterone secretion-based phenotypes in F2 mice by principal component analysis. Further, to pinpoint the genomic loci of the quantitative trait of the HPA axis stress response, we conducted genome-wide multipoint oligogenic linkage analyses based on Bayesian Markov chain Monte Carlo approach as well as parametric linkage in three-generation pedigrees, followed by a two-dimensional scan for epistasis and association analysis in freely segregating F2 mice using 267 single-nucleotide polymorphisms (SNPs, which were identified to consistently differ between HAB and LAB mice as genetic markers. Results HPA axis reactivity measurements and behavioural phenotypes were represented by independent principal components and demonstrated no correlation. Based on this finding, we identified one single quantitative trait locus (QTL on chromosome 3 showing a very strong evidence for linkage (2ln (L-score > 10, LOD > 23 and significant association (lowest Bonferroni adjusted p -28 to the neuroendocrine stress response. The location of the linkage peak was estimated at 42.3 cM (95% confidence interval: 41.3 - 43.3 cM and was shown to be in

  6. Intra-specific variability in life-history traits of Anadara tuberculosa (Mollusca: Bivalvia) in the mangrove ecosystem of the Southern coast of Ecuador.

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    Flores, Luis; Licandeo, Roberto; Cubillos, Luis A; Mora, Elba

    2014-06-01

    Anadara tuberculosa is one of the most important bivalves along the Western Pacific coast because of its commercial value. Nevertheless, the variability in growth, long-life span, natural mortality and reproductive parameters of this mangrove cockle has not yet been described. The aim of this study was to analyze these life-history traits in three areas of the Southern coast of Ecuador. Empirical and length-based methods were used to estimate these biological parameters. Body size data were collected from the commercial fishery between 2004 and 2011 in landing ports near to the Archipelago of Jambeli [Puerto Bolivar (PB), Puerto Jeli (PJ) and Puerto Hualtaco (PH)]. The von Bertalanffy growth parameters for combined sex were estimated between 70.87 to 93.45mm for L(infinity) and 0.22 to 0.80/year for k. The growth indices (PHI') ranged from 3.17 to 3.85, while the overall growth performance (OGP) ranged from 5.03 to 5.82. The mean of long-life span (t(max)), size and age at maturity (L50% and t50%) were estimated in 7.71 +/- 2.53 years, 39.13 +/- 2.24mm and 1.46 +/- 0.56 years for PB; 9.51 +/- 2.85 years, 37.78 +/- 1.95mm and 1.37 +/- 0.41 years for PJ and 5.81 +/- 2.11 years, 39.73 +/- 3.31mm and 0.94 +/- 0.41 years for PH. Natural mortality (M) ranged from 0.46 to 1.28/year. We concluded that significant intra-specific variation was observed in a temporal scale in PHI' and OGP indices as well as L50% and M. Therefore, temporal changes in these life-history traits should be taken into account when assessing the status of the mangrove cockle fishery.

  7. Diversities in virulence, antifungal activity, pigmentation and DNA fingerprint among strains of Burkholderia glumae.

    Science.gov (United States)

    Karki, Hari S; Shrestha, Bishnu K; Han, Jae Woo; Groth, Donald E; Barphagha, Inderjit K; Rush, Milton C; Melanson, Rebecca A; Kim, Beom Seok; Ham, Jong Hyun

    2012-01-01

    Burkholderia glumae is the primary causal agent of bacterial panicle blight of rice. In this study, 11 naturally avirulent and nine virulent strains of B. glumae native to the southern United States were characterized in terms of virulence in rice and onion, toxofalvin production, antifungal activity, pigmentation and genomic structure. Virulence of B. glumae strains on rice panicles was highly correlated to virulence on onion bulb scales, suggesting that onion bulb can be a convenient alternative host system to efficiently determine the virulence of B. glumae strains. Production of toxoflavin, the phytotoxin that functions as a major virulence factor, was closely associated with the virulence phenotypes of B. glumae strains in rice. Some strains of B. glumae showed various levels of antifungal activity against Rhizoctonia solani, the causal agent of sheath blight, and pigmentation phenotypes on casamino acid-peptone-glucose (CPG) agar plates regardless of their virulence traits. Purple and yellow-green pigments were partially purified from a pigmenting strain of B. glumae, 411gr-6, and the purple pigment fraction showed a strong antifungal activity against Collectotrichum orbiculare. Genetic variations were detected among the B. glumae strains from DNA fingerprinting analyses by repetitive element sequence-based PCR (rep-PCR) for BOX-A1R-based repetitive extragenic palindromic (BOX) or enterobacterial repetitive intergenic consensus (ERIC) sequences of bacteria; and close genetic relatedness among virulent but pigment-deficient strains were revealed by clustering analyses of DNA fingerprints from BOX-and ERIC-PCR.

  8. Species-specific differences in adaptive phenotypic plasticity in an ecologically relevant trophic trait: hypertrophic lips in Midas cichlid fishes.

    Science.gov (United States)

    Machado-Schiaffino, Gonzalo; Henning, Frederico; Meyer, Axel

    2014-07-01

    The spectacular species richness of cichlids and their diversity in morphology, coloration, and behavior have made them an ideal model for the study of speciation and adaptive evolution. Hypertrophic lips evolved repeatedly and independently in African and Neotropical cichlid radiations. Cichlids with hypertrophic lips forage predominantly in rocky crevices and it has been hypothesized that mechanical stress caused by friction could result in larger lips through phenotypic plasticity. To test the influence of the environment on the size and development of lips, we conducted a series of breeding and feeding experiments on Midas cichlids. Full-sibs of Amphilophus labiatus (thick-lipped) and Amphilophus citrinellus (thin-lipped) each were split into a control group which was fed food from the water column and a treatment group whose food was fixed to substrates. We found strong evidence for phenotypic plasticity on lip area in the thick-lipped species, but not in the thin-lipped species. Intermediate phenotypic values were observed in hybrids from thick- and thin-lipped species reared under "control" conditions. Thus, both a genetic, but also a phenotypic plastic component is involved in the development of hypertrophic lips in Neotropical cichlids. Moreover, species-specific adaptive phenotypic plasticity was found, suggesting that plasticity is selected for in recent thick-lipped species. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  9. Associations of prodynorphin sequence variation with alcohol dependence and related traits are phenotype-specific and sex-dependent.

    Science.gov (United States)

    Winham, Stacey J; Preuss, Ulrich W; Geske, Jennifer R; Zill, Peter; Heit, John A; Bakalkin, Georgy; Biernacka, Joanna M; Karpyak, Victor M

    2015-10-27

    We previously demonstrated that prodynorphin (PDYN) haplotypes and single nucleotide polymorphism (SNP) rs2281285 are associated with alcohol dependence and the propensity to drink in negative emotional states, and recent studies suggest that PDYN gene effects on substance dependence risk may be sex-related. We examined sex-dependent associations of PDYN variation with alcohol dependence and related phenotypes, including negative craving, time until relapse after treatment and the length of sobriety episodes before seeking treatment, in discovery and validation cohorts of European ancestry. We found a significant haplotype-by-sex interaction (p  =  0.03), suggesting association with alcohol dependence in males (p = 1E-4) but not females. The rs2281285 G allele increased risk for alcohol dependence in males in the discovery cohort (OR = 1.49, p = 0.002), with a similar trend in the validation cohort (OR = 1.35, p = 0.086). However, rs2281285 showed a trend towards association with increased negative craving in females in both the discovery (beta = 10.16, p = 0.045) and validation samples (OR = 7.11, p = 0.066). In the discovery cohort, rs2281285 was associated with time until relapse after treatment in females (HR = 1.72, p = 0.037); in the validation cohort, it was associated with increased length of sobriety episodes before treatment in males (beta = 13.49, p = 0.001). Our findings suggest that sex-dependent effects of PDYN variants in alcohol dependence are phenotype-specific.

  10. Bacterial Prostatitis: Bacterial Virulence, Clinical Outcomes, and New Directions.

    Science.gov (United States)

    Krieger, John N; Thumbikat, Praveen

    2016-02-01

    Four prostatitis syndromes are recognized clinically: acute bacterial prostatitis, chronic bacterial prostatitis, chronic prostatitis/chronic pelvic pain syndrome, and asymptomatic prostatitis. Because Escherichia coli represents the most common cause of bacterial prostatitis, we investigated the importance of bacterial virulence factors and antimicrobial resistance in E. coli strains causing prostatitis and the potential association of these characteristics with clinical outcomes. A structured literature review revealed that we have limited understanding of the virulence-associated characteristics of E. coli causing acute prostatitis. Therefore, we completed a comprehensive microbiological and molecular investigation of a unique strain collection isolated from healthy young men. We also considered new data from an animal model system suggesting certain E. coli might prove important in the etiology of chronic prostatitis/chronic pelvic pain syndrome. Our human data suggest that E. coli needs multiple pathogenicity-associated traits to overcome anatomic and immune responses in healthy young men without urological risk factors. The phylogenetic background and accumulation of an exceptional repertoire of extraintestinal pathogenic virulence-associated genes indicate that these E. coli strains belong to a highly virulent subset of uropathogenic variants. In contrast, antibiotic resistance confers little added advantage to E. coli strains in these healthy outpatients. Our animal model data also suggest that certain pathogenic E. coli may be important in the etiology of chronic prostatitis/chronic pelvic pain syndrome through mechanisms that are dependent on the host genetic background and the virulence of the bacterial strain.

  11. Dahl (S x R congenic strain analysis confirms and defines a chromosome 5 female-specific blood pressure quantitative trait locus to <7 Mbp.

    Directory of Open Access Journals (Sweden)

    Victoria L M Herrera

    Full Text Available The detection of multiple sex-specific blood pressure (BP quantitative trait loci (QTLs in independent total genome analyses of F2 (Dahl S x R-intercross male and female rat cohorts confirms clinical observations of sex-specific disease cause and response to treatment among hypertensive patients, and mandate the identification of sex-specific hypertension genes/mechanisms. We developed and studied two congenic strains, S.R5A and S.R5B introgressing Dahl R-chromosome 5 segments into Dahl S chromosome 5 region spanning putative BP-f1 and BP-f2 QTLs. Radiotelemetric non-stressed 24-hour BP analysis at four weeks post-high salt diet (8% NaCl challenge, identified only S.R5B congenic rats with lower SBP (-26.5 mmHg, P = 0.002, DBP (-23.7 mmHg, P = 0.004 and MAP (-25.1 mmHg, P = 0.002 compared with Dahl S female controls at four months of age confirming BP-f1 but not BP-f2 QTL on rat chromosome 5. The S.R5B congenic segment did not affect pulse pressure and relative heart weight indicating that the gene underlying BP-f1 does not influence arterial stiffness and cardiac hypertrophy. The results of our congenic analysis narrowed BP-f1 to chromosome 5 coordinates 134.9-141.5 Mbp setting up the basis for further fine mapping of BP-f1 and eventual identification of the specific gene variant accounting for BP-f1 effect on blood pressure.

  12. Dahl (S x R) congenic strain analysis confirms and defines a chromosome 5 female-specific blood pressure quantitative trait locus to <7 Mbp.

    Science.gov (United States)

    Herrera, Victoria L M; Pasion, Khristine A; Moran, Ann Marie; Ruiz-Opazo, Nelson

    2012-01-01

    The detection of multiple sex-specific blood pressure (BP) quantitative trait loci (QTLs) in independent total genome analyses of F2 (Dahl S x R)-intercross male and female rat cohorts confirms clinical observations of sex-specific disease cause and response to treatment among hypertensive patients, and mandate the identification of sex-specific hypertension genes/mechanisms. We developed and studied two congenic strains, S.R5A and S.R5B introgressing Dahl R-chromosome 5 segments into Dahl S chromosome 5 region spanning putative BP-f1 and BP-f2 QTLs. Radiotelemetric non-stressed 24-hour BP analysis at four weeks post-high salt diet (8% NaCl) challenge, identified only S.R5B congenic rats with lower SBP (-26.5 mmHg, P = 0.002), DBP (-23.7 mmHg, P = 0.004) and MAP (-25.1 mmHg, P = 0.002) compared with Dahl S female controls at four months of age confirming BP-f1 but not BP-f2 QTL on rat chromosome 5. The S.R5B congenic segment did not affect pulse pressure and relative heart weight indicating that the gene underlying BP-f1 does not influence arterial stiffness and cardiac hypertrophy. The results of our congenic analysis narrowed BP-f1 to chromosome 5 coordinates 134.9-141.5 Mbp setting up the basis for further fine mapping of BP-f1 and eventual identification of the specific gene variant accounting for BP-f1 effect on blood pressure.

  13. GENERAL AND SPECIFIC COMBINING ABILITY OF INITIAL PARENTAL FORMS IN TOMATO FOR COMPLEX OF ECONOMICALLY VALUABLE TRAITS TO DEVELOP HYBRIDS F1 OF CHERRY AND COCKTAIL TYPES

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    R. K. Rechets

    2017-01-01

    Full Text Available Results of estimation of general and specific combining ability of male and female parental tomato forms were given for complex of traits. The estimation was carried out according to incomplete diallel crosses 15x15. Such varities   as   ‘Trapeza’,  Rosovaya  kapelka’,  ‘Seniorita’, ‘Ocharovanie’,  ‘Tigris’   ‘Vishnya  Zheltaya’  (Gavrish, ‘Denezhnoye Derevo’ (national breeding, and  lines: ‘46/06’,  ‘49/09’,  ‘295/09’,  ‘336/11’,  ‘354/11’,  ‘357/11’, ‘388/09’ (nor, ‘498’ (selection of TARI were used as intial breeding accessions, differing in bush type (determinate and indeterminate, duration of vegetative phase (ultraearly,  early, medium early, middle-ripening, fruit  shape (rounded, oval, fruit color (red, pink, black, orange, tiger and with the gene nor, fruit weight (10 g. and more, brush structure (dense, friable. As a results, ‘Trapeza’, ‘Vishnya Zheltaya’, ‘Ocharovaniye’, ‘Seniorita’, and lines: ‘295/10’, ‘49/09’,  ‘498’,  ‘357/11’,  ‘354/11’,  ‘388/09’  (nor were selected and recommended to be used in breeding program for development of heterotic hybrids with high fruit setting and generative bush type. The promising hybrids F1 with high constants of specific combining ability for a complex of economically valuable traits have been observed. Because of different lines and accessions were used in crossings, these hybrids varied in internode length of cluster type, classical or shorten; rounded or oval fruit shape; fruit  color, red (F1   combinations ‘354/11’ х ‘Seniorita’, ‘Trapeza’ х  ‘L.49/09’,  L.  ‘49/09’  х  L.354/11, pink (F1 combination ‘Rosovaya Kapelka’ х ‘L.354/11’, yellow (F1 combination ‘Ocharovaniye’ х  ‘Vishiya Zheltaya’, deep brown (F1 combination  ‘L.357/11’ х ‘L.354/11’.

  14. Brucella, nitrogen and virulence.

    Science.gov (United States)

    Ronneau, Severin; Moussa, Simon; Barbier, Thibault; Conde-Álvarez, Raquel; Zuniga-Ripa, Amaia; Moriyon, Ignacio; Letesson, Jean-Jacques

    2016-08-01

    The brucellae are α-Proteobacteria causing brucellosis, an important zoonosis. Although multiplying in endoplasmic reticulum-derived vacuoles, they cause no cell death, suggesting subtle but efficient use of host resources. Brucellae are amino-acid prototrophs able to grow with ammonium or use glutamate as the sole carbon-nitrogen source in vitro. They contain more than twice amino acid/peptide/polyamine uptake genes than the amino-acid auxotroph Legionella pneumophila, which multiplies in a similar vacuole, suggesting a different nutritional strategy. During these two last decades, many mutants of key actors in nitrogen metabolism (transporters, enzymes, regulators, etc.) have been described to be essential for full virulence of brucellae. Here, we review the genomic and experimental data on Brucella nitrogen metabolism and its connection with virulence. An analysis of various aspects of this metabolism (transport, assimilation, biosynthesis, catabolism, respiration and regulation) has highlighted differences and similarities in nitrogen metabolism with other α-Proteobacteria. Together, these data suggest that, during their intracellular life cycle, the brucellae use various nitrogen sources for biosynthesis, catabolism and respiration following a strategy that requires prototrophy and a tight regulation of nitrogen use.

  15. Overlapping and disease specific trait, response, and reflection impulsivity in adolescents with first-episode schizophrenia spectrum disorders or attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Jepsen, J R M; Rydkjaer, J; Fagerlund, B; Pagsberg, A K; Jespersen, R Av F; Glenthøj, B Y; Oranje, B

    2018-03-01

    Schizophrenia and attention-deficit/hyperactivity disorder (ADHD) are developmental disorders with shared clinical characteristics such as cognitive impairments and impulsivity. Impulsivity is a core feature of ADHD and an important factor in aggression, violence, and substance use in schizophrenia. Based on the hypothesis that schizophrenia and ADHD represent a continuum of neurodevelopmental impairments, the aim was to identify overlapping and disease specific forms of impulsivity. Adolescents between 12 and 17 years of age were assessed with the Schedule for Affective Disorders and Schizophrenia for School-aged Children - Present and Lifetime Version. Subjects with early-onset, first-episode schizophrenia spectrum disorders (EOS) (N = 29) or ADHD (N = 29) and healthy controls (N = 45) were compared on two performance measures (Information Sampling Task, Stop Signal Task) and a subjective personality trait measure of impulsivity (Barratt Impulsiveness Scale, Version 11 (BIS-11)). Significantly increased reflection impulsivity was observed in ADHD but not in the EOS group. No significant response inhibition deficits (stop signal reaction time) were found in the two clinical groups. The ADHD and the EOS group showed significantly increased motor, attentional, and non-planning subtraits of impulsivity. Impaired pre-decisional information gathering appeared to be specific for ADHD while the information gathering was not significantly reduced in subjects with EOS. Neither the ADHD nor EOS group showed impaired response inhibition but shared increased personality subtraits of attentional, non-planning, and motor impulsivity although the latter was significantly more pronounced in ADHD. These increased subtraits of impulsivity may reflect diagnostic non-specific neurodevelopmental impairments in ADHD and EOS in adolescence.

  16. Helicobacter pylori virulence factors in development of gastric carcinoma.

    Science.gov (United States)

    Wang, Ming-Yi; Liu, Xiao-Fei; Gao, Xiao-Zhong

    2015-01-01

    Helicobacter pylori plays a vital role in the pathogenesis of gastric carcinoma. However, only a relatively small proportion of individuals infected with H. pylori develop gastric carcinoma. Differences in the incidence of gastric carcinoma among infected individuals can be explained, at least partly, by the different genotypes of H. pylori virulence factors. Thus far, many virulence factors of H. pylori, such as Cag PAI, VacA, OMPs and DupA, have been reported to be involved in the development of gastric cancer. The risk of developing gastric cancer during H. pylori infection is affected by specific host-microbe interactions that are independent of H. pylori virulence factors. In this review, we discuss virulence factors of H. pylori and their role in the development of gastric carcinoma that will provide further understanding of the biological interactions of H. pylori with the host.

  17. Trait Emotional Intelligence and Personality

    Science.gov (United States)

    Furnham, Adrian; Petrides, K. V.

    2015-01-01

    This study investigated if the linkages between trait emotional intelligence (trait EI) and the Five-Factor Model of personality were invariant between men and women. Five English-speaking samples (N = 307-685) of mostly undergraduate students each completed a different measure of the Big Five personality traits and either the full form or short form of the Trait Emotional Intelligence Questionnaire (TEIQue). Across samples, models predicting global TEIQue scores from the Big Five were invariant between genders, with Neuroticism and Extraversion being the strongest trait EI correlates, followed by Conscientiousness, Agreeableness, and Openness. However, there was some evidence indicating that the gender-specific contributions of the Big Five to trait EI vary depending on the personality measure used, being more consistent for women. Discussion focuses on the validity of the TEIQue as a measure of trait EI and its psychometric properties, more generally. PMID:25866439

  18. Evidence for specificity of the impact of punishment on error-related brain activity in high versus low trait anxious individuals.

    Science.gov (United States)

    Meyer, Alexandria; Gawlowska, Magda

    2017-10-01

    A previous study suggests that when participants were punished with a loud noise after committing errors, the error-related negativity (ERN) was enhanced in high trait anxious individuals. The current study sought to extend these findings by examining the ERN in conditions when punishment was related and unrelated to error commission as a function of individual differences in trait anxiety symptoms; further, the current study utilized an electric shock as an aversive unconditioned stimulus. Results confirmed that the ERN was increased when errors were punished among high trait anxious individuals compared to low anxious individuals; this effect was not observed when punishment was unrelated to errors. Findings suggest that the threat-value of errors may underlie the association between certain anxious traits and punishment-related increases in the ERN. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Heterologous expression of Ralp3 in Streptococcus pyogenes M2 and M6 strains affects the virulence characteristics.

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    Nikolai Siemens

    Full Text Available BACKGROUND: Ralp3 is a transcriptional regulator present in a serotype specific fashion on the chromosome of the human pathogen Streptococcus pyogenes (group A streptococci, GAS. In serotypes harbouring the ralp3 gene either positive or negative effects on important metabolic and virulence genes involved in colonization and immune evasion in the human host were observed. A previous study revealed that deletion of ralp3 in a GAS M49 serotype significantly attenuated many virulence traits and caused metabolic disadvantages. This leads to two questions: (i which kind of consequences could Ralp3 expression have in GAS serotypes naturally lacking this gene, and (ii is Ralp3 actively lost during evolution in these serotypes. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the role of Ralp3 in GAS M2 and M6 pathogenesis. Both serotypes lack ralp3 on their chromosome. The heterologous expression of ralp3 in both serotypes resulted in reduced attachment to and internalization into the majority of tested epithelial cells. Both ralp3 expression strains showed a decreased ability to survive in human blood and exclusively M2::ralp3 showed decreased survival in human serum. Both mutants secreted more active SpeB in the supernatant, resulting in a higher activity compared to wild type strains. The respective M2 and M6 wild type strains outcompeted the ralp3 expression strains in direct metabolic competition assays. The phenotypic changes observed in the M2:ralp3 and M6:ralp3 were verified on the transcriptional level. Consistent with the virulence data, tested genes showed transcript level changes in the same direction. CONCLUSIONS/SIGNIFICANCE: Together these data suggest that Ralp3 can take over transcriptional control of virulence genes in serotypes lacking the ralp3 gene. Those serotypes most likely lost Ralp3 during evolution since obviously expression of this gene is disadvantageous for metabolism and pathogenesis.

  20. Heterologous expression of Ralp3 in Streptococcus pyogenes M2 and M6 strains affects the virulence characteristics.

    Science.gov (United States)

    Siemens, Nikolai; Kreikemeyer, Bernd

    2013-01-01

    Ralp3 is a transcriptional regulator present in a serotype specific fashion on the chromosome of the human pathogen Streptococcus pyogenes (group A streptococci, GAS). In serotypes harbouring the ralp3 gene either positive or negative effects on important metabolic and virulence genes involved in colonization and immune evasion in the human host were observed. A previous study revealed that deletion of ralp3 in a GAS M49 serotype significantly attenuated many virulence traits and caused metabolic disadvantages. This leads to two questions: (i) which kind of consequences could Ralp3 expression have in GAS serotypes naturally lacking this gene, and (ii) is Ralp3 actively lost during evolution in these serotypes. We investigated the role of Ralp3 in GAS M2 and M6 pathogenesis. Both serotypes lack ralp3 on their chromosome. The heterologous expression of ralp3 in both serotypes resulted in reduced attachment to and internalization into the majority of tested epithelial cells. Both ralp3 expression strains showed a decreased ability to survive in human blood and exclusively M2::ralp3 showed decreased survival in human serum. Both mutants secreted more active SpeB in the supernatant, resulting in a higher activity compared to wild type strains. The respective M2 and M6 wild type strains outcompeted the ralp3 expression strains in direct metabolic competition assays. The phenotypic changes observed in the M2:ralp3 and M6:ralp3 were verified on the transcriptional level. Consistent with the virulence data, tested genes showed transcript level changes in the same direction. Together these data suggest that Ralp3 can take over transcriptional control of virulence genes in serotypes lacking the ralp3 gene. Those serotypes most likely lost Ralp3 during evolution since obviously expression of this gene is disadvantageous for metabolism and pathogenesis.

  1. Effect of stable and fluctuating temperatures on the life history traits of Anopheles arabiensis and An. quadriannulatus under conditions of inter- and intra-specific competition.

    Science.gov (United States)

    Davies, Craig; Coetzee, Maureen; Lyons, Candice L

    2016-06-14

    Constant and fluctuating temperatures influence important life-history parameters of malaria vectors which has implications for community organization and the malaria disease burden. The effects of environmental temperature on the hatch rate, survivorship and development rate of Anopheles arabiensis and An. quadriannulatus under conditions of inter- and intra-specific competition are studied. The eggs and larvae of laboratory established colonies were reared under controlled conditions at one constant (25 °C) and two fluctuating (20-30 °C and 18-35 °C) temperature treatments at a ratio of 1:0 or 1:1 (An. arabiensis: An. quadriannulatus). Monitoring of hatch rate, development rate and survival was done at three intervals, 6 to 8 h apart depending on developmental stage. Parametric ANOVAs were used where assumptions of equal variances and normality were met, and a Welch ANOVA where equal variance was violated (α = 0.05). Temperature significantly influenced the measured life-history traits and importantly, this was evident when these species co-occurred. A constant temperature resulted in a higher hatch rate in single species, larval treatments (P competitor (P < 0.05). The influence of temperature treatment on the development rate and survival from egg/larvae to adult differed across species treatments. Fluctuating temperatures incorporating the extremes influence the key life-history parameters measured here with An. arabiensis outcompeting An. quadriannulatus under these conditions. The quantification of the response variables measured here improve our knowledge of the link between temperature and species interactions and provide valuable information for modelling of vector population dynamics.

  2. Visual recognition of age class and preference for infantile features: implications for species-specific vs universal cognitive traits in primates.

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    Anna Sato

    Full Text Available Despite not knowing the exact age of individuals, humans can estimate their rough age using age-related physical features. Nonhuman primates show some age-related physical features; however, the cognitive traits underlying their recognition of age class have not been revealed. Here, we tested the ability of two species of Old World monkey, Japanese macaques (JM and Campbell's monkeys (CM, to spontaneously discriminate age classes using visual paired comparison (VPC tasks based on the two distinct categories of infant and adult images. First, VPCs were conducted in JM subjects using conspecific JM stimuli. When analyzing the side of the first look, JM subjects significantly looked more often at novel images. Based on analyses of total looking durations, JM subjects looked at a novel infant image longer than they looked at a familiar adult image, suggesting the ability to spontaneously discriminate between the two age classes and a preference for infant over adult images. Next, VPCs were tested in CM subjects using heterospecific JM stimuli. CM subjects showed no difference in the side of their first look, but looked at infant JM images longer than they looked at adult images; the fact that CMs were totally naïve to JMs suggested that the attractiveness of infant images transcends species differences. This is the first report of visual age class recognition and a preference for infant over adult images in nonhuman primates. Our results suggest not only species-specific processing for age class recognition but also the evolutionary origins of the instinctive human perception of baby cuteness schema, proposed by the ethologist Konrad Lorenz.

  3. A meta-analysis of thyroid-related traits reveals novel loci and gender-specific differences in the regulation of thyroid function.

    Directory of Open Access Journals (Sweden)

    Eleonora Porcu

    Full Text Available Thyroid hormone is essential for normal metabolism and development, and overt abnormalities in thyroid function lead to common endocrine disorders affecting approximately 10% of individuals over their life span. In addition, even mild alterations in thyroid function are associated with weight changes, atrial fibrillation, osteoporosis, and psychiatric disorders. To identify novel variants underlying thyroid function, we performed a large meta-analysis of genome-wide association studies for serum levels of the highly heritable thyroid function markers TSH and FT4, in up to 26,420 and 17,520 euthyroid subjects, respectively. Here we report 26 independent associations, including several novel loci for TSH (PDE10A, VEGFA, IGFBP5, NFIA, SOX9, PRDM11, FGF7, INSR, ABO, MIR1179, NRG1, MBIP, ITPK1, SASH1, GLIS3 and FT4 (LHX3, FOXE1, AADAT, NETO1/FBXO15, LPCAT2/CAPNS2. Notably, only limited overlap was detected between TSH and FT4 associated signals, in spite of the feedback regulation of their circulating levels by the hypothalamic-pituitary-thyroid axis. Five of the reported loci (PDE8B, PDE10A, MAF/LOC440389, NETO1/FBXO15, and LPCAT2/CAPNS2 show strong gender-specific differences, which offer clues for the known sexual dimorphism in thyroid function and related pathologies. Importantly, the TSH-associated loci contribute not only to variation within the normal range, but also to TSH values outside the reference range, suggesting that they may be involved in thyroid dysfunction. Overall, our findings explain, respectively, 5.64% and 2.30% of total TSH and FT4 trait variance, and they improve the current knowledge of the regulation of hypothalamic-pituitary-thyroid axis function and the consequences of genetic variation for hypo- or hyperthyroidism.

  4. Panorama of Prevalence of Malocclusion, Treatment Needs, Specific Occlusal Traits & Gender Distribution in Patients Seeking Orthodontic Treatment in Kolhapur Population - A Prospective Cross-sectional Study

    Directory of Open Access Journals (Sweden)

    Shraddha Subhash Shetti

    2013-01-01

    Full Text Available Aim: To assess the prevalence of malocclusion, treatment needs and specific occlusal traits among Kolhapur population. Materials & Method: The sample comprised 500 individuals: that is, 250 boys & 250 girls between the age group of 13 -20 years. The sample was drawn from among the patients reporting for the treatment of malocclusion to the department. After intraoral examination, dental casts of the patients were assessed later and scored. A mouth mirror, a ruler & a sliding digital caliper was used. For every individual, variables related to malocclusion were recorded on a specially designed registration chart. A set of 10 photographs showing a range of dental attractiveness of the aesthetic component based on IOTN was followed and the data was subjected to statistical analysis. Results: About 48.80 % individuals had Angle′s Class I malocclusion; 34.60 % had Class II division 1; 2% had Class IT division 2 and 1.80% had Class Ill malocclusion. Deep-bite type of vertical malocclusion was present in 62.60% of the sample and 37.40% subjects had a normal overbite. The next most prevalent type of malocclusion was deviation of dental midlines which was found in 50.40% of sample. Orthodontic treatment need as assessed by the DHC of the IOTN were such that 24.20 %and 53.40% fell into grade 4 and grade 5 respectively. Therefore definitely requiring treatment and as assessed by the AC of the IOTN 27.40% and 18.20% sample fell into grades 8 - 10 and grade 10 respectively, as it was the least aesthetic arrangement of the dentition therefore definitely requiring treatment. Conclusions: Orthodontic treatment indices such as IOTN can be used effectively with less subjective bias to determine the orthodontic treatment need. The study suggests that there is a borderline to definite need for treatment in a large amount of population in the semirural western Maharashtra.

  5. Sequencing of a QTL-rich region of the Theobroma cacao genome using pooled BACs and the identification of trait specific candidate genes

    Directory of Open Access Journals (Sweden)

    Blackmon Barbara P

    2011-07-01

    Full Text Available Abstract Background BAC-based physical maps provide for sequencing across an entire genome or a selected sub-genomic region of biological interest. Such a region can be approached with next-generation whole-genome sequencing and assembly as if it were an independent small genome. Using the minimum tiling path as a guide, specific BAC clones representing the prioritized genomic interval are selected, pooled, and used to prepare a sequencing library. Results This pooled BAC approach was taken to sequence and assemble a QTL-rich region, of ~3 Mbp and represented by twenty-seven BACs, on linkage group 5 of the Theobroma cacao cv. Matina 1-6 genome. Using various mixtures of read coverages from paired-end and linear 454 libraries, multiple assemblies of varied quality were generated. Quality was assessed by comparing the assembly of 454 reads with a subset of ten BACs individually sequenced and assembled using Sanger reads. A mixture of reads optimal for assembly was identified. We found, furthermore, that a quality assembly suitable for serving as a reference genome template could be obtained even with a reduced depth of sequencing coverage. Annotation of the resulting assembly revealed several genes potentially responsible for three T. cacao traits: black pod disease resistance, bean shape index, and pod weight. Conclusions Our results, as with other pooled BAC sequencing reports, suggest that pooling portions of a minimum tiling path derived from a BAC-based physical map is an effective method to target sub-genomic regions for sequencing. While we focused on a single QTL region, other QTL regions of importance could be similarly sequenced allowing for biological discovery to take place before a high quality whole-genome assembly is completed.

  6. A Meta-Analysis of Thyroid-Related Traits Reveals Novel Loci and Gender-Specific Differences in the Regulation of Thyroid Function

    Science.gov (United States)

    Volpato, Claudia B.; Wilson, Scott G.; Cappola, Anne R.; Bos, Steffan D.; Deelen, Joris; den Heijer, Martin; Freathy, Rachel M.; Lahti, Jari; Liu, Chunyu; Lopez, Lorna M.; Nolte, Ilja M.; O'Connell, Jeffrey R.; Tanaka, Toshiko; Trompet, Stella; Arnold, Alice; Bandinelli, Stefania; Beekman, Marian; Böhringer, Stefan; Brown, Suzanne J.; Buckley, Brendan M.; Camaschella, Clara; de Craen, Anton J. M.; Davies, Gail; de Visser, Marieke C. H.; Ford, Ian; Forsen, Tom; Frayling, Timothy M.; Fugazzola, Laura; Gögele, Martin; Hattersley, Andrew T.; Hermus, Ad R.; Hofman, Albert; Houwing-Duistermaat, Jeanine J.; Jensen, Richard A.; Kajantie, Eero; Kloppenburg, Margreet; Lim, Ee M.; Masciullo, Corrado; Mariotti, Stefano; Minelli, Cosetta; Mitchell, Braxton D.; Nagaraja, Ramaiah; Netea-Maier, Romana T.; Palotie, Aarno; Persani, Luca; Piras, Maria G.; Psaty, Bruce M.; Räikkönen, Katri; Richards, J. Brent; Rivadeneira, Fernando; Sala, Cinzia; Sabra, Mona M.; Sattar, Naveed; Shields, Beverley M.; Soranzo, Nicole; Starr, John M.; Stott, David J.; Sweep, Fred C. G. J.; Usala, Gianluca; van der Klauw, Melanie M.; van Heemst, Diana; van Mullem, Alies; H.Vermeulen, Sita; Visser, W. Edward; Walsh, John P.; Westendorp, Rudi G. J.; Widen, Elisabeth; Zhai, Guangju; Cucca, Francesco; Deary, Ian J.; Eriksson, Johan G.; Ferrucci, Luigi; Fox, Caroline S.; Jukema, J. Wouter; Kiemeney, Lambertus A.; Pramstaller, Peter P.; Schlessinger, David; Shuldiner, Alan R.; Slagboom, Eline P.; Uitterlinden, André G.; Vaidya, Bijay; Visser, Theo J.; Wolffenbuttel, Bruce H. R.; Meulenbelt, Ingrid; Rotter, Jerome I.; Spector, Tim D.; Hicks, Andrew A.; Toniolo, Daniela; Sanna, Serena; Peeters, Robin P.; Naitza, Silvia

    2013-01-01

    Thyroid hormone is essential for normal metabolism and development, and overt abnormalities in thyroid function lead to common endocrine disorders affecting approximately 10% of individuals over their life span. In addition, even mild alterations in thyroid function are associated with weight changes, atrial fibrillation, osteoporosis, and psychiatric disorders. To identify novel variants underlying thyroid function, we performed a large meta-analysis of genome-wide association studies for serum levels of the highly heritable thyroid function markers TSH and FT4, in up to 26,420 and 17,520 euthyroid subjects, respectively. Here we report 26 independent associations, including several novel loci for TSH (PDE10A, VEGFA, IGFBP5, NFIA, SOX9, PRDM11, FGF7, INSR, ABO, MIR1179, NRG1, MBIP, ITPK1, SASH1, GLIS3) and FT4 (LHX3, FOXE1, AADAT, NETO1/FBXO15, LPCAT2/CAPNS2). Notably, only limited overlap was detected between TSH and FT4 associated signals, in spite of the feedback regulation of their circulating levels by the hypothalamic-pituitary-thyroid axis. Five of the reported loci (PDE8B, PDE10A, MAF/LOC440389, NETO1/FBXO15, and LPCAT2/CAPNS2) show strong gender-specific differences, which offer clues for the known sexual dimorphism in thyroid function and related pathologies. Importantly, the TSH-associated loci contribute not only to variation within the normal range, but also to TSH values outside the reference range, suggesting that they may be involved in thyroid dysfunction. Overall, our findings explain, respectively, 5.64% and 2.30% of total TSH and FT4 trait variance, and they improve the current knowledge of the regulation of hypothalamic-pituitary-thyroid axis function and the consequences of genetic variation for hypo- or hyperthyroidism. PMID:23408906

  7. Same Traits, Different Variance

    Directory of Open Access Journals (Sweden)

    Jamie S. Churchyard

    2014-02-01

    Full Text Available Personality trait questionnaires are regularly used in individual differences research to examine personality scores between participants, although trait researchers tend to place little value on intra-individual variation in item ratings within a measured trait. The few studies that examine variability indices have not considered how they are related to a selection of psychological outcomes, so we recruited 160 participants (age M = 24.16, SD = 9.54 who completed the IPIP-HEXACO personality questionnaire and several outcome measures. Heterogenous within-subject differences in item ratings were found for every trait/facet measured, with measurement error that remained stable across the questionnaire. Within-subject standard deviations, calculated as measures of individual variation in specific item ratings within a trait/facet, were related to outcomes including life satisfaction and depression. This suggests these indices represent valid constructs of variability, and that researchers administering behavior statement trait questionnaires with outcome measures should also apply item-level variability indices.

  8. Virulence Factors of Streptococcus mutans.

    Science.gov (United States)

    1986-08-01

    763512/715242 Final Report U VIRULENCE FACTORS OF STREPTOCOCCUS MUTANS U Samuel Rosen Department of Oral Biology For the Period April 1, 1983 - June 30...00 FINAL REPORT VIRULENCE FACTORS OF STREPTOCOCCUS MUTANS Sam Rosen, Irving Shklair, E. X. Beck and F. M. Beck Ohio State University Columbus,Oh and...206-212. Johnson CP, Gorss S, Hillman JD (1978). Cariogenic properties of LDH deficient mutants of streptococcus mutans . J Dent Res 57, Special Issue

  9. Virulence Factors of Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Paul Sinclair

    1991-01-01

    environment with respect to pH. The spiral shape of the cells and their flagellar motility allow them to wind themselves into the mucous layer of the stomach. Some evidence exists for the production of strong proteolytic activity, hence degrading the mucous barrier and increasing permeability for the organism. Cyroroxin excreted by the bacteria may have some effect on the surrounding cells, with the possible lysis and release of bacterial growth factors. There is evidence that a chemotactic response is present due to these growth factors and their higher concentration in the intracellular spaces. The presence of specific and nonspecific adhesion has also been demonstrated, thus allowing the bacterium, once at the epithelial cell surface, to attach and avoid being washed off by movement within the stomach. Although treatment with antimicrobials eradicates the organism and improves symptoms of peptic ulcer patients, there is no indication that the same occurs in nonulcer dyspepsia patients. Further work is essential to describe the virulence mechanisms of H pylori and the possible pathogenic role of the organism.

  10. Screening for spontaneous virulent mutants of barley powdery mildew (Erysiphe graminis DC)

    International Nuclear Information System (INIS)

    Torp, J.; Jensen, H.P.

    1989-01-01

    Full text: Seedlings of 4 barley lines possessing resistance genes M1-a6, M1-a12 or M1-g were inoculated with powdery mildew culture CR3, which is a-virulent to the 4 host lines. In total, 50 million conidia were screened for the occurrence of virulent mutants, 43 putative virulent mutants were found. They could be grouped into 5 genotypes according to the virulence spectrum. They might have originated by one of the following events: 1. admixture, 2. physiological events that allow a few conidia to establish colonies in spite of the presence of a functional gene for resistance, 3. mutation in a gene for specificity, 4. deletion or mutation in some kind of suppressing element in which case more than one virulence may be affected. Based upon the virulence spectra, mating type, biochemical tests and analysis of test crosses, 3 of the genotypes were clearly classified as not being of mutational origin. Of the two remaining genotypes one differed in 4 virulences, the other by two virulences and one avirulence. Based upon expectations from the gene-for-gene concept, it is concluded that both were not of mutational origin. If in fact there are derived from a mutation, the concept of gene-for-gene interactions would have to be revised. Assuming that no mutations for virulence were found in this experiment, the spontaneous mutation frequency from avirulence to virulence would be below 2x10 -8 . (author)

  11. CRISPR interference can prevent natural transformation and virulence acquisition during in vivo bacterial infection.

    Science.gov (United States)

    Bikard, David; Hatoum-Aslan, Asma; Mucida, Daniel; Marraffini, Luciano A

    2012-08-16

    Pathogenic bacterial strains emerge largely due to transfer of virulence and antimicrobial resistance genes between bacteria, a process known as horizontal gene transfer (HGT). Clustered, regularly interspaced, short palindromic repeat (CRISPR) loci of bacteria and archaea encode a sequence-specific defense mechanism against bacteriophages and constitute a programmable barrier to HGT. However, the impact of CRISPRs on the emergence of virulence is unknown. We programmed the human pathogen Streptococcus pneumoniae with CRISPR sequences that target capsule genes, an essential pneumococcal virulence factor, and show that CRISPR interference can prevent transformation of nonencapsulated, avirulent pneumococci into capsulated, virulent strains during infection in mice. Further, at low frequencies bacteria can lose CRISPR function, acquire capsule genes, and mount a successful infection. These results demonstrate that CRISPR interference can prevent the emergence of virulence in vivo and that strong selective pressure for virulence or antibiotic resistance can lead to CRISPR loss in bacterial pathogens. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Effective but costly, evolved mechanisms of defense against a virulent opportunistic pathogen in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Yixin H Ye

    2009-04-01

    Full Text Available Drosophila harbor substantial genetic variation for antibacterial defense, and investment in immunity is thought to involve a costly trade-off with life history traits, including development, life span, and reproduction. To understand the way in which insects invest in fighting bacterial infection, we selected for survival following systemic infection with the opportunistic pathogen Pseudomonas aeruginosa in wild-caught Drosophila melanogaster over 10 generations. We then examined genome-wide changes in expression in the selected flies relative to unselected controls, both of which had been infected with the pathogen. This powerful combination of techniques allowed us to specifically identify the genetic basis of the evolved immune response. In response to selection, population-level survivorship to infection increased from 15% to 70%. The evolved capacity for defense was costly, however, as evidenced by reduced longevity and larval viability and a rapid loss of the trait once selection pressure was removed. Counter to expectation, we observed more rapid developmental rates in the selected flies. Selection-associated changes in expression of genes with dual involvement in developmental and immune pathways suggest pleiotropy as a possible mechanism for the positive correlation. We also found that both the Toll and the Imd pathways work synergistically to limit infectivity and that cellular immunity plays a more critical role in overcoming P. aeruginosa infection than previously reported. This work reveals novel pathways by which Drosophila can survive infection with a virulent pathogen that may be rare in wild populations, however, due to their cost.

  13. Somatic recombination in wheat stem rust leads to virulence for Ug99-effective SR50 resistance

    Science.gov (United States)

    Race-specific resistance genes protect much of the global wheat crop from stem rust disease caused by Puccinia graminis f. sp. tritici (Pgt), but often break down due to evolution of new virulent pathogen races. To understand the molecular mechanisms of virulence evolution in Pgt we identified the p...

  14. Correlates of virulence in a frog-killing fungal pathogen: evidence from a California amphibian decline

    Science.gov (United States)

    Jonah Piovia-Scott; Karen Pope; S. Joy Worth; Erica Bree Rosenblum; Dean Simon; Gordon Warburton; Louise A. Rollins-Smith; Laura K. Reinert; Heather L. Wells; Dan Rejmanek; Sharon Lawler; Janet Foley

    2015-01-01

    The fungal pathogen Batrachochytrium dendrobatidis (Bd) has caused declines and extinctions in amphibians worldwide, and there is increasing evidence that some strains of this pathogen are more virulent than others. While a number of putative virulence factors have been identified, few studies link these factors to specific epizootic events. We...

  15. Role of dupA in virulence of Helicobacter pylori.

    Science.gov (United States)

    Talebi Bezmin Abadi, Amin; Perez-Perez, Guillermo

    2016-12-14

    Helicobacter pylori ( H. pylori ) is a gastric human pathogen associated with acute and chronic gastritis, 70% of all gastric ulcers, 85% of all duodenal ulcers, and both forms of stomach cancer, mucosal-associated lymphoid tissue (MALT) lymphoma and adenocarcinoma. Recently, attention has focused on possible relationship between presence of certain virulence factor and H. pylori -associated diseases. Some contradictory data between this bacterium and related disorders has been observed since not all the colonized individuals develop to severe disease. The reported diseases plausibility related to H. pylori specific virulence factors became an interesting story about this organism. Although a number of putative virulence factors have been identified including cytotoxin-associated gene a ( cagA ) and vacA , there are conflicting data about their actual participation as specific risk factor for H. pylori -related diseases. Duodenal ulcer promoting gene a ( dupA ) is a virulence factor of H. pylori that is highly associated with duodenal ulcer development and reduced risk of gastric cancer. The prevalence of dupA in H. pylori strains isolated from western countries is relatively higher than in H. pylori strains from Asian countries. Current confusing epidemiological reports will continue unless future sophisticated and molecular studies provide data on functional and complete dupA cluster in H. pylori infected individuals. This paper elucidates available knowledge concerning role of dupA in virulence of H. pylori after a decade of its discovery.

  16. Host age modulates parasite infectivity, virulence and reproduction.

    Science.gov (United States)

    Izhar, Rony; Ben-Ami, Frida

    2015-07-01

    Host age is one of the most striking differences among hosts within most populations, but there is very little data on how age-dependent effects impact ecological and evolutionary dynamics of both the host and the parasite. Here, we examined the influence of host age (juveniles, young and old adults) at parasite exposure on host susceptibility, fecundity and survival as well as parasite transmission, using two clones of the water flea Daphnia magna and two clones of its bacterial parasite Pasteuria ramosa. Younger D. magna were more susceptible to infection than older ones, regardless of host or parasite clone. Also, younger-infected D. magna became castrated faster than older hosts, but host and parasite clone effects contributed to this trait as well. Furthermore, the early-infected D. magna produced considerably more parasite transmission stages than late-infected ones, while host age at exposure did not affect virulence as it is defined in models (host mortality). When virulence is defined more broadly as the negative effects of infection on host fitness, by integrating the parasitic effects on host fecundity and mortality, then host age at exposure seems to slide along a negative relationship between host and parasite fitness. Thus, the virulence-transmission trade-off differs strongly among age classes, which in turn affects predictions of optimal virulence. Age-dependent effects on host susceptibility, virulence and parasite transmission could pose an important challenge for experimental and theoretical studies of infectious disease dynamics and disease ecology. Our results present a call for a more explicit stage-structured theory for disease, which will incorporate age-dependent epidemiological parameters. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

  17. Cerebellum and personality traits.

    Science.gov (United States)

    Petrosini, Laura; Cutuli, Debora; Picerni, Eleonora; Laricchiuta, Daniela

    2015-02-01

    Personality traits are multidimensional traits comprising cognitive, emotional, and behavioral characteristics, and a wide array of cerebral structures mediate individual variability. Differences in personality traits covary with brain morphometry in specific brain regions. A cerebellar role in emotional and affective processing and on personality characteristics has been suggested. In a large sample of healthy subjects of both sexes and differently aged, the macro- and micro-structural variations of the cerebellum were correlated with the scores obtained in the Temperament and Character Inventory (TCI) by Cloninger. Cerebellar volumes were associated positively with Novelty Seeking scores and negatively with Harm Avoidance scores. Given the cerebellar contribution in personality traits and emotional processing, we investigated the cerebellar involvement even in alexithymia, construct of personality characterized by impairment in cognitive, emotional, and affective processing. Interestingly, the subjects with high alexithymic traits had larger volumes in the bilateral Crus 1. The cerebellar substrate for some personality dimensions extends the relationship between personality and brain areas to a structure up to now thought to be involved mainly in motor and cognitive functions, much less in emotional processes and even less in personality individual differences. The enlarged volumes of Crus 1 in novelty seekers and alexithymics support the tendency to action featuring both personality constructs. In fact, Novelty Seeking and alexithymia are rooted in behavior and inescapably have a strong action component, resulting in stronger responses in the structures more focused on action and embodiment, as the cerebellum is.

  18. Virulence genes and subclone status as markers of experimental virulence in a murine sepsis model among Escherichia coli sequence type 131 clinical isolates from Spain.

    Directory of Open Access Journals (Sweden)

    Irene Merino

    Full Text Available To assess experimental virulence among sequence type 131 (ST131 Escherichia coli bloodstream isolates in relation to virulence genotype and subclone.We analysed 48 Spanish ST131 bloodstream isolates (2010 by PCR for ST131 subclone status (H30Rx, H30 non-Rx, or non-H30, virulence genes (VGs, and O-type. Then we compared these traits with virulence in a murine sepsis model, as measured by illness severity score (ISS and rapid lethality (mean ISS ≥ 4.Of the 48 study isolates, 65% were H30Rx, 21% H30 non-Rx, and 15% non-H30; 44% produced ESBLs, 98% were O25b, and 83% qualified as extraintestinal pathogenic E. coli (ExPEC. Of 49 VGs, ibeA and iss were associated significantly with non-H30 isolates, and sat, iha and malX with H30 isolates. Median VG scores differed by subclone, i.e., 12 (H30Rx, 10 (H30 non-Rx, and 11 (non-H30 (p < 0.01. Nearly 80% of isolates represented a described virotype. In mice, H30Rx and non-H30 isolates were more virulent than H30 non-Rx isolates (according to ISS [p = 0.03] and rapid lethality [p = 0.03], as were ExPEC isolates compared with non-ExPEC isolates (median ISS, 4.3 vs. 2.7: p = 0.03. In contrast, most individual VGs, VG scores, VG profiles, and virotypes were not associated with mouse virulence.ST131 subclone and ExPEC status, but not individual VGs, VG scores or profiles, or virotypes, predicted mouse virulence. Given the lower virulence of non-Rx H30 isolates, hypervirulence probably cannot explain the ST131-H30 clade's epidemic emergence.

  19. Prevalence of Escherichia coli virulence genes in patients with ...

    African Journals Online (AJOL)

    In this study, we investigated the prevalence of the virulence genes specific for five major pathogroups of diarrheagenic Escherichia coli (DEC) in primary cultures from diarrhoeagenic patients in Burkina Faso. Methodology: From September 2016 to Mars 2017, a total of 211 faecal samples from diarrhoeagenic patients from ...

  20. Brain Region-Specific Expression of Genes Mapped within Quantitative Trait Loci for Behavioral Responsiveness to Acute Stress in Fisher 344 and Wistar Kyoto Male Rats (Postprint)

    Science.gov (United States)

    2018-03-12

    stress in Fisher 344 and Wistar Kyoto male rats. PLoS ONE 13(3): e0194293. https://doi. org /10.1371/journal.pone.0194293 Editor: Alexandra Kavushansky...complex traits in outbred rats. Nature genetics. 2013; 45(7): https://doi. org /10.1038/ng.2644 PMC3821058. PMID: 23708188 15. Ahmadiyeh N, Churchill GA...congenic mouse strains. Nature Genetics. 1997; 17:280. https://doi. org /10.1038/ng1197-280 PMID: 9354790 21. The SC. SNP and haplotype mapping for genetic

  1. Virulence marker candidates in N-protein of viral haemorrhagic septicaemia virus (VHSV): virulence variability within VHSV Ib clones

    DEFF Research Database (Denmark)

    Ito, Takafumi; Kurita, Jun; Mori, Koh-ichiro

    2018-01-01

    , upon cloning by limited dilution, both isolates appeared to be heterogeneous in terms of reactivity with nucleo (N)-protein-specific MAbs as well their gene sequences. Infection trials in rainbow trout further revealed differences in the virulence of these virus clones derived from the same primary...

  2. “Are We There Yet?”: Deciding When One Has Demonstrated Specific Genetic Causation in Complex Diseases and Quantitative Traits

    Science.gov (United States)

    Page, Grier P.; George, Varghese; Go, Rodney C.; Page, Patricia Z.; Allison, David B.

    2003-01-01

    Although mathematical relationships can be proven by deductive logic, biological relationships can only be inferred from empirical observations. This is a distinct disadvantage for those of us who strive to identify the genes involved in complex diseases and quantitative traits. If causation cannot be proven, however, what does constitute sufficient evidence for causation? The philosopher Karl Popper said, “Our belief in a hypothesis can have no stronger basis than our repeated unsuccessful critical attempts to refute it.” We believe that to establish causation, as scientists, we must make a serious attempt to refute our own hypotheses and to eliminate all known sources of bias before association becomes causation. In addition, we suggest that investigators must provide sufficient data and evidence of their unsuccessful efforts to find any confounding biases. In this editorial, we discuss what “causation” means in the context of complex diseases and quantitative traits, and we suggest guidelines for steps that may be taken to address possible confounders of association before polymorphisms may be called “causative.” PMID:13680525

  3. The Csr/Rsm system of Yersinia and related pathogens: a post-transcriptional strategy for managing virulence.

    Science.gov (United States)

    Heroven, Ann Kathrin; Böhme, Katja; Dersch, Petra

    2012-04-01

    This review emphasizes the function and regulation of the Csr regulatory system in the human enteropathogen Yersinia pseudotuberculosis and compares its features with the homologous Csr/Rsm systems of related pathogens. The Csr/Rsm systems of eubacteria form a complex regulatory network in which redundant non-translated Csr/Rsm-RNAs bind the RNA-binding protein CsrA/RsmA, thereby preventing its interaction with mRNA targets. The Csr system is controlled by the BarA/UvrY-type of two-component sensor-regulator systems. Apart from that, common or pathogen-specific regulators control the abundance of the Csr components. The coordinate control of virulence factors and infection-linked physiological traits by the Csr/Rsm systems helps the pathogens to adapt individually to rapidly changing conditions to which they are exposed during the different stages of an infection. As Csr/Rsm function is relevant for full virulence, it represents a target suitable for antimicrobial drug development.

  4. Ecological interactions drive evolutionary loss of traits.

    Science.gov (United States)

    Ellers, Jacintha; Kiers, E Toby; Currie, Cameron R; McDonald, Bradon R; Visser, Bertanne

    2012-10-01

    Loss of traits can dramatically alter the fate of species. Evidence is rapidly accumulating that the prevalence of trait loss is grossly underestimated. New findings demonstrate that traits can be lost without affecting the external phenotype, provided the lost function is compensated for by species interactions. This is important because trait loss can tighten the ecological relationship between partners, affecting the maintenance of species interactions. Here, we develop a new perspective on so-called `compensated trait loss' and how this type of trait loss may affect the evolutionary dynamics between interacting organisms. We argue that: (1) the frequency of compensated trait loss is currently underestimated because it can go unnoticed as long as ecological interactions are maintained; (2) by analysing known cases of trait loss, specific factors promoting compensated trait loss can be identified and (3) genomic sequencing is a key way forwards in detecting compensated trait loss. We present a comprehensive literature survey showing that compensated trait loss is taxonomically widespread, can involve essential traits, and often occurs as replicated evolutionary events. Despite its hidden nature, compensated trait loss is important in directing evolutionary dynamics of ecological relationships and has the potential to change facultative ecological interactions into obligatory ones. © 2012 Blackwell Publishing Ltd/CNRS.

  5. Effect of disruption of a cutinase gene (cutA) on virulence and tissue specificity of Fusarium solani f. sp. cucurbitae race 2 toward Cucurbita maxima and C. moschata.

    Science.gov (United States)

    Crowhurst, R N; Binnie, S J; Bowen, J K; Hawthorne, B T; Plummer, K M; Rees-George, J; Rikkerink, E H; Templeton, M D

    1997-04-01

    A 3.9-kb genomic DNA fragment from the cucurbit pathogen Fusarium solani f. sp. cucurbitae race 2 was cloned. Sequence analysis revealed an open reading frame of 690 nucleotides interrupted by a single 51-bp intron. The nucleotide and predicted amino acid sequences showed 92 and 98% identity, respectively, to those of the cutA gene of the pea pathogen F. solani f. sp. pisi. A gene replacement vector was constructed and used to generate cutA- mutants that were detected with a polymerase chain reaction (PCR) assay. Seventy-one cutA- mutants were identified among the 416 transformants screened. Vector integration was assessed by Southern analysis in 23 of these mutants. PCR and Southern analysis data showed the level of homologous integration was 14%. Disruption of the cutA locus in mutants was confirmed by RNA gel blot hybridization. Neither virulence on Cucurbita maxima cv. Delica at any of six different inoculum concentrations, nor pathogenicity on intact fruit of four different species or cultivars of cucurbit or hypocotyl tissue of C. maxima cv. Crown, was found to be affected by disruption of the cutA gene.

  6. Clonality, virulence and antimicrobial resistance of enteroaggregative Escherichia coli from Mirzapur, Bangladesh

    DEFF Research Database (Denmark)

    Chattaway, Marie Anne; Day, Michaela; Mtwale, Julia

    2017-01-01

    Purpose. This study investigates the virulence and antimicrobial resistance in association with common clonal complexes (CCs) of enteroaggregative Escherichia coli (EAEC) isolated from Bangladesh. The aim was to determine whether specific CCs were more likely to be associated with putative...... virulence genes and/or antimicrobial resistance.Methodology. The presence of 15 virulence genes (by PCR) and susceptibility to 18 antibiotics were determined for 151 EAEC isolated from cases and controls during an intestinal infectious disease study carried out between 2007-2011 in the rural setting...... between the presence of virulence or antimicrobial resistance genes in isolates of EAEC from cases versus controls. However, when stratified by clonal complex (CC) one CC associated with cases harboured more virulence factors (CC40) and one CC harboured more resistance genes (CC38) than the average...

  7. Stability and variability of virulence of Phytophthorainfestans assessed in a ring test across European laboratories

    NARCIS (Netherlands)

    Andrivon, D.; Avendaño-Córcoles, J.; Cameron, A.M.; Raaij, van H.M.G.

    2011-01-01

    Determining virulence towards race-specific resistance genes is a prerequisite to understanding the response of pathogen populations to resistant cultivars, and therefore to assess the durability of these resistance genes and the performance of resistance management strategies. In Phytophthora

  8. Pathogenomic inference of virulence-associated genes in Leptospira interrogans.

    Directory of Open Access Journals (Sweden)

    Jason S Lehmann

    Full Text Available Leptospirosis is a globally important, neglected zoonotic infection caused by spirochetes of the genus Leptospira. Since genetic transformation remains technically limited for pathogenic Leptospira, a systems biology pathogenomic approach was used to infer leptospiral virulence genes by whole genome comparison of culture-attenuated Leptospira interrogans serovar Lai with its virulent, isogenic parent. Among the 11 pathogen-specific protein-coding genes in which non-synonymous mutations were found, a putative soluble adenylate cyclase with host cell cAMP-elevating activity, and two members of a previously unstudied ∼15 member paralogous gene family of unknown function were identified. This gene family was also uniquely found in the alpha-proteobacteria Bartonella bacilliformis and Bartonella australis that are geographically restricted to the Andes and Australia, respectively. How the pathogenic Leptospira and these two Bartonella species came to share this expanded gene family remains an evolutionary mystery. In vivo expression analyses demonstrated up-regulation of 10/11 Leptospira genes identified in the attenuation screen, and profound in vivo, tissue-specific up-regulation by members of the paralogous gene family, suggesting a direct role in virulence and host-pathogen interactions. The pathogenomic experimental design here is generalizable as a functional systems biology approach to studying bacterial pathogenesis and virulence and should encourage similar experimental studies of other pathogens.

  9. Pathogenomic inference of virulence-associated genes in Leptospira interrogans.

    Science.gov (United States)

    Lehmann, Jason S; Fouts, Derrick E; Haft, Daniel H; Cannella, Anthony P; Ricaldi, Jessica N; Brinkac, Lauren; Harkins, Derek; Durkin, Scott; Sanka, Ravi; Sutton, Granger; Moreno, Angelo; Vinetz, Joseph M; Matthias, Michael A

    2013-01-01

    Leptospirosis is a globally important, neglected zoonotic infection caused by spirochetes of the genus Leptospira. Since genetic transformation remains technically limited for pathogenic Leptospira, a systems biology pathogenomic approach was used to infer leptospiral virulence genes by whole genome comparison of culture-attenuated Leptospira interrogans serovar Lai with its virulent, isogenic parent. Among the 11 pathogen-specific protein-coding genes in which non-synonymous mutations were found, a putative soluble adenylate cyclase with host cell cAMP-elevating activity, and two members of a previously unstudied ∼15 member paralogous gene family of unknown function were identified. This gene family was also uniquely found in the alpha-proteobacteria Bartonella bacilliformis and Bartonella australis that are geographically restricted to the Andes and Australia, respectively. How the pathogenic Leptospira and these two Bartonella species came to share this expanded gene family remains an evolutionary mystery. In vivo expression analyses demonstrated up-regulation of 10/11 Leptospira genes identified in the attenuation screen, and profound in vivo, tissue-specific up-regulation by members of the paralogous gene family, suggesting a direct role in virulence and host-pathogen interactions. The pathogenomic experimental design here is generalizable as a functional systems biology approach to studying bacterial pathogenesis and virulence and should encourage similar experimental studies of other pathogens.

  10. Salmonella-secreted Virulence Factors

    Energy Technology Data Exchange (ETDEWEB)

    Heffron, Fred; Niemann, George; Yoon, Hyunjin; Kidwai, Afshan S.; Brown, Roslyn N.; McDermott, Jason E.; Smith, Richard D.; Adkins, Joshua N.

    2011-05-01

    In this short review we discuss secreted virulence factors of Salmonella, which directly affect Salmonella interaction with its host. Salmonella secretes protein to subvert host defenses but also, as discussed, to reduce virulence thereby permitting the bacteria to persist longer and more successfully disperse. The type III secretion system (TTSS) is the best known and well studied of the mechanisms that enable secretion from the bacterial cytoplasm to the host cell cytoplasm. Other secretion systems include outer membrane vesicles, which are present in all Gram-negative bacteria examined to date, two-partner secretion, and type VI secretion will also be addressed. Excellent reviews of Salmonella secreted effectors have focused on themes such as actin rearrangements, vesicular trafficking, ubiquitination, and the activities of the virulence factors themselves. This short review is based on S. Typhimurium infection of mice because it is a model of typhoid like disease in humans. We have organized effectors in terms of events that happen during the infection cycle and how secreted effectors may be involved.

  11. Coping skills: role of trait sport confidence and trait anxiety.

    Science.gov (United States)

    Cresswell, Scott; Hodge, Ken

    2004-04-01

    The current research assesses relationships among coping skills, trait sport confidence, and trait anxiety. Two samples (n=47 and n=77) of international competitors from surf life saving (M=23.7 yr.) and touch rugby (M=26.2 yr.) completed the Athletic Coping Skills Inventory, Trait Sport Confidence Inventory, and Sport Anxiety Scale. Analysis yielded significant correlations amongst trait anxiety, sport confidence, and coping. Specifically confidence scores were positively associated with coping with adversity scores and anxiety scores were negatively associated. These findings support the inclusion of the personality characteristics of confidence and anxiety within the coping model presented by Hardy, Jones, and Gould, Researchers should be aware that confidence and anxiety may influence the coping processes of athletes.

  12. Antimicrobial resistance and virulence profile of enterococci isolated from poultry and cattle sources in Nigeria.

    Science.gov (United States)

    Ngbede, Emmanuel Ochefije; Raji, Mashood Abiola; Kwanashie, Clara Nna; Kwaga, Jacob Kwada Paghi

    2017-03-01

    This study investigated the occurrence, antimicrobial resistance and virulence of Enterococcus from poultry and cattle farms. Three hundred and ninety samples: cloacal/rectal swabs (n = 260) and manure (n = 130] were processed for recovery of Enterococcus species. Standard bacteriological methods were used to isolate, identify and characterize Enterococcus species for antimicrobial susceptibility and expression of virulence traits. Detection of antibiotic resistance and virulence genes was carried out by polymerase chain reaction. Enterococcus was recovered from 167 (42.8%) of the 390 samples tested with a predominance of Enterococcus faecium (27.7%). Other species detected were Enterococcus gallinarum, Enterococcus faecalis, Enterococcus hirae, Enterococcus raffinosus, Enterococcus avium, Enterococcus casseliflavus, Enterococcus mundtii and Enterococcus durans. All the isolates tested were susceptible to vancomycin, but resistance to tetracycline, erythromycin, ampicillin and gentamicin was also observed among 61.0, 61.0, 45.1 and 32.7% of the isolates, respectively. Sixty (53.1%) of the isolates were multidrug resistant presenting as 24 different resistance patterns with resistance to gentamicin-erythromycin-streptomycin-tetracycline (CN-ERY-STR-TET) being the most common (n = 11) pattern. In addition to expression of virulence traits (haemolysin, gelatinase, biofilm production), antibiotic resistance (tetK, tetL, tetM, tetO and ermB) and virulence (asa1, gelE, cylA) genes were detected among the isolates. Also, in vitro transfer of resistance determinants was observed among 75% of the isolates tested. Our data revealed poultry, cattle and manure in this area are hosts to varying Enterococcus species harbouring virulence and resistance determinants that can be transferred to other organisms and also are important for causing nosocomial infection.

  13. Bistable expression of virulence genes in salmonella leads to the formation of an antibiotic-tolerant subpopulation.

    Directory of Open Access Journals (Sweden)

    Markus Arnoldini

    2014-08-01

    Full Text Available Phenotypic heterogeneity can confer clonal groups of organisms with new functionality. A paradigmatic example is the bistable expression of virulence genes in Salmonella typhimurium, which leads to phenotypically virulent and phenotypically avirulent subpopulations. The two subpopulations have been shown to divide labor during S. typhimurium infections. Here, we show that heterogeneous virulence gene expression in this organism also promotes survival against exposure to antibiotics through a bet-hedging mechanism. Using microfluidic devices in combination with fluorescence time-lapse microscopy and quantitative image analysis, we analyzed the expression of virulence genes at the single cell level and related it to survival when exposed to antibiotics. We found that, across different types of antibiotics and under concentrations that are clinically relevant, the subpopulation of bacterial cells that express virulence genes shows increased survival after exposure to antibiotics. Intriguingly, there is an interplay between the two consequences of phenotypic heterogeneity. The bet-hedging effect that arises through heterogeneity in virulence gene expression can protect clonal populations against avirulent mutants that exploit and subvert the division of labor within these populations. We conclude that bet-hedging and the division of labor can arise through variation in a single trait and interact with each other. This reveals a new degree of functional complexity of phenotypic heterogeneity. In addition, our results suggest a general principle of how pathogens can evade antibiotics: Expression of virulence factors often entails metabolic costs and the resulting growth retardation could generally increase tolerance against antibiotics and thus compromise treatment.

  14. Clonality, virulence and antimicrobial resistance of enteroaggregative Escherichia coli from Mirzapur, Bangladesh.

    Science.gov (United States)

    Chattaway, Marie Anne; Day, Michaela; Mtwale, Julia; White, Emma; Rogers, James; Day, Martin; Powell, David; Ahmad, Marwa; Harris, Ross; Talukder, Kaisar Ali; Wain, John; Jenkins, Claire; Cravioto, Alejandro

    2017-10-01

    This study investigates the virulence and antimicrobial resistance in association with common clonal complexes (CCs) of enteroaggregative Escherichia coli (EAEC) isolated from Bangladesh. The aim was to determine whether specific CCs were more likely to be associated with putative virulence genes and/or antimicrobial resistance. The presence of 15 virulence genes (by PCR) and susceptibility to 18 antibiotics were determined for 151 EAEC isolated from cases and controls during an intestinal infectious disease study carried out between 2007-2011 in the rural setting of Mirzapur, Bangladesh (Kotloff KL, Blackwelder WC, Nasrin D, Nataro JP, Farag TH et al.Clin Infect Dis 2012;55:S232-S245). These data were then analysed in the context of previously determined serotypes and clonal complexes defined by multi-locus sequence typing. Overall there was no association between the presence of virulence or antimicrobial resistance genes in isolates of EAEC from cases versus controls. However, when stratified by clonal complex (CC) one CC associated with cases harboured more virulence factors (CC40) and one CC harboured more resistance genes (CC38) than the average. There was no direct link between the virulence gene content and antibiotic resistance. Strains within a single CC had variable virulence and resistance gene content indicating independent and multiple gene acquisitions over time. In Bangladesh, there are multiple clonal complexes of EAEC harbouring a variety of virulence and resistance genes. The emergence of two of the most successful clones appeared to be linked to either increased virulence (CC40) or antimicrobial resistance (CC38), but increased resistance and virulence were not found in the same clonal complexes.

  15. Molecular Characterization of Putative Virulence Determinants in Burkholderia pseudomallei

    Directory of Open Access Journals (Sweden)

    Suat Moi Puah

    2014-01-01

    Full Text Available The Gram-negative saprophyte Burkholderia pseudomallei is the causative agent of melioidosis, an infectious disease which is endemic in Southeast Asia and northern Australia. This bacterium possesses many virulence factors which are thought to contribute to its survival and pathogenicity. Using a virulent clinical isolate of B. pseudomallei and an attenuated strain of the same B. pseudomallei isolate, 6 genes BPSL2033, BP1026B_I2784, BP1026B_I2780, BURPS1106A_A0094, BURPS1106A_1131, and BURPS1710A_1419 were identified earlier by PCR-based subtractive hybridization. These genes were extensively characterized at the molecular level, together with an additional gene BPSL3147 that had been identified by other investigators. Through a reverse genetic approach, single-gene knockout mutants were successfully constructed by using site-specific insertion mutagenesis and were confirmed by PCR. BPSL2033::Km and BURPS1710A_1419::Km mutants showed reduced rates of survival inside macrophage RAW 264.7 cells and also low levels of virulence in the nematode infection model. BPSL2033::Km demonstrated weak statistical significance (P=0.049 at 8 hours after infection in macrophage infection study but this was not seen in BURPS1710A_1419::Km. Nevertheless, complemented strains of both genes were able to partially restore the gene defects in both in vitro and in vivo studies, thus suggesting that they individually play a minor role in the virulence of B. pseudomallei.

  16. Relevance of Peptide Uptake Systems to the Physiology and Virulence of Streptococcus agalactiae

    OpenAIRE

    Samen, Ulrike; Gottschalk, Birgit; Eikmanns, Bernhard J.; Reinscheid, Dieter J.

    2004-01-01

    Streptococcus agalactiae is a major cause of invasive infections in human newborns. To satisfy its growth requirements, S. agalactiae takes up 9 of the 20 proteinogenic amino acids from the environment. Defined S. agalactiae mutants in one or several of four putative peptide permease systems were constructed and tested for peptide uptake, growth in various media, and expression of virulence traits. Oligopeptide uptake by S. agalactiae was shown to be mediated by the ABC transporter OppA1-F, w...

  17. The metabolic regulator CodY links L. monocytogenes metabolism to virulence by directly activating the virulence regulatory gene, prfA

    Science.gov (United States)

    Lobel, Lior; Sigal, Nadejda; Borovok, Ilya; Belitsky, Boris R.; Sonenshein, Abraham L.; Herskovits, Anat A.

    2015-01-01

    Summary Metabolic adaptations are critical to the ability of bacterial pathogens to grow within host cells and are normally preceded by sensing of host-specific metabolic signals, which in turn can influence the pathogen's virulence state. Previously, we reported that the intracellular bacterial pathogen Listeria monocytogenes responds to low availability of branched-chain amino acids (BCAA) within mammalian cells by up-regulating both BCAA biosynthesis and virulence genes. The induction of virulence genes required the BCAA-responsive transcription regulator, CodY, but the molecular mechanism governing this mode of regulation was unclear. In this report, we demonstrate that CodY directly binds the coding sequence of the L. monocytogenes master virulence activator gene, prfA, 15 nt downstream of its start codon, and that this binding results in up-regulation of prfA transcription specifically under low concentrations of BCAA. Mutating this site abolished CodY binding and reduced prfA transcription in macrophages, and attenuated bacterial virulence in mice. Notably, the mutated binding site did not alter prfA transcription or PrfA activity under other conditions that are known to activate PrfA, such as during growth in the presence of glucose-1-phosphate. This study highlights the tight crosstalk between L. monocytogenes metabolism and virulence' while revealing novel features of CodY-mediated regulation. PMID:25430920

  18. The association between DRD2/ANKK1, 5-HTTLPR gene, and specific personality trait on antisocial alcoholism among Han Chinese in Taiwan.

    Science.gov (United States)

    Wu, Chin-Yeh; Wu, Yi-Syuan; Lee, Jia-Fu; Huang, San-Yuan; Yu, Lung; Ko, Huei-Chen; Lu, Ru-Band

    2008-06-05

    Cloninger suggested that type II alcoholism was associated with higher novelty seeking and less harm avoidance behaviors, which was similar to antisocial alcoholism. Most previous studies have failed to recruit subjects that have antisocial personality disorder without alcoholism due to the high coexisting likelihood of having antisocial personality disorder with alcoholism in the majority of the examined populations. Thus, recruitment of individuals with antisocial non-alcoholism (antisocial personality disorder) served as an important control group in examining Cloninger's hypothesis. Due to the documented protective effects against alcoholism of ALDH2*1/*2 or *2/*2 genotype among the Han Chinese population, we recruited antisocial non-alcoholics from the Han Chinese population in Taiwan to verify Cloninger's hypotheses. A total of 127 Han Chinese subjects were recruited who met the diagnosis of antisocial alcoholism (n = 43) or antisocial non-alcoholism (n = 84). We found that the antisocial alcoholism group scored higher on the novelty seeking behavior than did the antisocial non-alcoholism group (t = 2.61, P = 0.01), but no difference was observed on the harm avoidance dimension between these two groups (t = 0.15, P = 0.88). In the novelty seeking scores, after stratification of DRD2 TaqI A genotypes, only a significant difference in 5-HTTLPR polymorphisms between antisocial alcoholics and antisocial non-alcoholics was found, indicating an interaction between DRD2 TaqI A1+ (include A1/A1 or A1/A2) and 5-HTTLPR S/S genotype (t = 2.75, P = 0.01) However, no significant difference was found in the harm avoidance personality trait between these two groups of Han Chinese in Taiwan. (c) 2007 Wiley-Liss, Inc.

  19. Quantitative traits and diversification.

    Science.gov (United States)

    FitzJohn, Richard G

    2010-12-01

    Quantitative traits have long been hypothesized to affect speciation and extinction rates. For example, smaller body size or increased specialization may be associated with increased rates of diversification. Here, I present a phylogenetic likelihood-based method (quantitative state speciation and extinction [QuaSSE]) that can be used to test such hypotheses using extant character distributions. This approach assumes that diversification follows a birth-death process where speciation and extinction rates may vary with one or more traits that evolve under a diffusion model. Speciation and extinction rates may be arbitrary functions of the character state, allowing much flexibility in testing models of trait-dependent diversification. I test the approach using simulated phylogenies and show that a known relationship between speciation and a quantitative character could be recovered in up to 80% of the cases on large trees (500 species). Consistent with other approaches, detecting shifts in diversification due to differences in extinction rates was harder than when due to differences in speciation rates. Finally, I demonstrate the application of QuaSSE to investigate the correlation between body size and diversification in primates, concluding that clade-specific differences in diversification may be more important than size-dependent diversification in shaping the patterns of diversity within this group.

  20. Mycobacterium tuberculosis nuoG is a virulence gene that inhibits apoptosis of infected host cells.

    Directory of Open Access Journals (Sweden)

    Kamalakannan Velmurugan

    2007-07-01

    Full Text Available The survival and persistence of Mycobacterium tuberculosis depends on its capacity to manipulate multiple host defense pathways, including the ability to actively inhibit the death by apoptosis of infected host cells. The genetic basis for this anti-apoptotic activity and its implication for mycobacterial virulence have not been demonstrated or elucidated. Using a novel gain-of-function genetic screen, we demonstrated that inhibition of infection-induced apoptosis of macrophages is controlled by multiple genetic loci in M. tuberculosis. Characterization of one of these loci in detail revealed that the anti-apoptosis activity was attributable to the type I NADH-dehydrogenase of M. tuberculosis, and was mainly due to the subunit of this multicomponent complex encoded by the nuoG gene. Expression of M. tuberculosis nuoG in nonpathogenic mycobacteria endowed them with the ability to inhibit apoptosis of infected human or mouse macrophages, and increased their virulence in a SCID mouse model. Conversely, deletion of nuoG in M. tuberculosis ablated its ability to inhibit macrophage apoptosis and significantly reduced its virulence in mice. These results identify a key component of the genetic basis for an important virulence trait of M. tuberculosis and support a direct causal relationship between virulence of pathogenic mycobacteria and their ability to inhibit macrophage apoptosis.

  1. Virulence factor genes possessing Enterococcus faecalis strains from rabbits and their sensitivity to enterocins

    Directory of Open Access Journals (Sweden)

    M. Pogány Simonová

    2017-03-01

    Full Text Available Information concerning the virulence factor genes and antibiotic resistance of rabbit enterococci is limited, so in this study we tested the virulence factor genes in Enterococcus faecalis strains from rabbits. Moreover, their resistance/sensitivity to antibiotics and sensitivity to enterocins was also tested, with the aim of contributing to our enterocin spectra study and to indicate the possibility of enterocin application in prevention or contaminant elimination in rabbit husbandry. A total of 144 rabbit samples were treated using a standard microbiological method. Thirty-one pure colonies of the species Enterococcus faecalis were identified, using the MALDI-TOF identification system and confirmed using phenotyping, among which 15 strains were virulence factor gene absent. The gelE gene was the most detected (42%; however, the expression of gelatinase phenotype did not always correlate with the detection of gelE. Strains did not show ß-haemolysis and were mostly resistant to tested antibiotics, but sensitive to enterocins (Ent, mainly to Ents EK13=A (P, 2019 and Ent M. Rabbit E. faecalis strains displayed antibiotic resistant traits and the presence of expressed and silent virulence genes, but they showed high levels of sensitivity to natural antimicrobials-enterocins, which indicates the possible prevention of multidrug and virulent enterococcal contaminants by enterocins.

  2. Evolving ideas about genetics underlying insect virulence to plant resistance in rice-brown planthopper interactions.

    Science.gov (United States)

    Kobayashi, Tetsuya

    2016-01-01

    Many plant-parasite interactions that include major plant resistance genes have subsequently been shown to exhibit features of gene-for-gene interactions between plant Resistance genes and parasite Avirulence genes. The brown planthopper (BPH) Nilaparvata lugens is an important pest of rice (Oryza sativa). Historically, major Resistance genes have played an important role in agriculture. As is common in gene-for-gene interactions, evolution of BPH virulence compromises the effectiveness of singly-deployed resistance genes. It is therefore surprising that laboratory studies of BPH have supported the conclusion that virulence is conferred by changes in many genes rather than a change in a single gene, as is proposed by the gene-for-gene model. Here we review the behaviour, physiology and genetics of the BPH in the context of host plant resistance. A problem for genetic understanding has been the use of various insect populations that differ in frequencies of virulent genotypes. We show that the previously proposed polygenic inheritance of BPH virulence can be explained by the heterogeneity of parental populations. Genetic mapping of Avirulence genes indicates that virulence is a monogenic trait. These evolving concepts, which have brought the gene-for-gene model back into the picture, are accelerating our understanding of rice-BPH interactions at the molecular level. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Transcriptional control of drug resistance, virulence and immune system evasion in pathogenic fungi: a cross-species comparison.

    Directory of Open Access Journals (Sweden)

    Pedro Pais

    2016-10-01

    Full Text Available Transcription factors are key players in the control of the activation or repression of gene expression programs in response to environmental stimuli. The study of regulatory networks taking place in fungal pathogens is a promising research topic that can help in the fight against these pathogens by targeting specific fungal pathways as a whole, instead of targeting more specific effectors of virulence or drug resistance. This review is focused on the analysis of regulatory networks playing a central role in the referred mechanisms in the human fungal pathogens Aspergillus fumigatus, Cryptococcus neoformans, Candida albicans, Candida glabrata, Candida parapsilosis and Candida tropicalis. Current knowledge on the activity of the transcription factors characterized in each of these pathogenic fungal species will be addressed. Particular focus is given to their mechanisms of activation, regulatory targets and phenotypic outcome. The review further provides an evaluation on the conservation of transcriptional circuits among different fungal pathogens, highlighting the pathways that translate common or divergent traits among these species in what concerns their drug resistance, virulence and host immune evasion features. It becomes evident that the regulation of transcriptional networks is complex and presents significant variations among different fungal pathogens. Only the oxidative stress regulators Yap1 and Skn7 are conserved among all studied species; while some transcription factors, involved in nutrient homeostasis, pH adaptation, drug resistance and morphological switching are present in several, though not all species. Interestingly, in some cases not very homologous transcription factors display orthologous functions, whereas some homologous proteins have diverged in terms of their function in different species. A few cases of species specific transcription factors are also observed.

  4. Transcriptional Control of Drug Resistance, Virulence and Immune System Evasion in Pathogenic Fungi: A Cross-Species Comparison.

    Science.gov (United States)

    Pais, Pedro; Costa, Catarina; Cavalheiro, Mafalda; Romão, Daniela; Teixeira, Miguel C

    2016-01-01

    Transcription factors are key players in the control of the activation or repression of gene expression programs in response to environmental stimuli. The study of regulatory networks taking place in fungal pathogens is a promising research topic that can help in the fight against these pathogens by targeting specific fungal pathways as a whole, instead of targeting more specific effectors of virulence or drug resistance. This review is focused on the analysis of regulatory networks playing a central role in the referred mechanisms in the human fungal pathogens Aspergillus fumigatus, Cryptococcus neoformans, Candida albicans, Candida glabrata, Candida parapsilosis , and Candida tropicalis . Current knowledge on the activity of the transcription factors characterized in each of these pathogenic fungal species will be addressed. Particular focus is given to their mechanisms of activation, regulatory targets and phenotypic outcome. The review further provides an evaluation on the conservation of transcriptional circuits among different fungal pathogens, highlighting the pathways that translate common or divergent traits among these species in what concerns their drug resistance, virulence and host immune evasion features. It becomes evident that the regulation of transcriptional networks is complex and presents significant variations among different fungal pathogens. Only the oxidative stress regulators Yap1 and Skn7 are conserved among all studied species; while some transcription factors, involved in nutrient homeostasis, pH adaptation, drug resistance and morphological switching are present in several, though not all species. Interestingly, in some cases not very homologous transcription factors display orthologous functions, whereas some homologous proteins have diverged in terms of their function in different species. A few cases of species specific transcription factors are also observed.

  5. Virulence Genes and Antibiotic Susceptibilities of Uropathogenic E. coli Strains.

    Science.gov (United States)

    Uzun, Cengiz; Oncül, Oral; Gümüş, Defne; Alan, Servet; Dayioğlu, Nurten; Küçüker, Mine Anğ

    2015-01-01

    The aim of this study is to detect the presence of and possible relation between virulence genes and antibiotic resistance in E. coli strains isolated from patients with acute, uncomplicated urinary tract infections (UTI). 62 E. coli strains isolated from patients with acute, uncomplicated urinary tract infections (50 strains isolated from acute uncomplicated cystitis cases (AUC); 12 strains from acute uncomplicated pyelonephritis cases (AUP)) were screened for virulence genes [pap (pyelonephritis-associated pili), sfa/foc (S and F1C fimbriae), afa (afimbrial adhesins), hly (hemolysin), cnf1 (cytotoxic necrotizing factor), aer (aerobactin), PAI (pathogenicity island marker), iroN (catecholate siderophore receptor), ompT (outer membrane protein T), usp (uropathogenic specific protein)] by PCR and for antimicrobial resistance by disk diffusion method according to CLSI criteria. It was found that 56 strains (90.3%) carried at least one virulence gene. The most common virulence genes were ompT (79%), aer (51.6%), PAI (51.6%) and usp (56.5%). 60% of the strains were resistant to at least one antibiotic. The highest resistance rates were against ampicillin (79%) and co-trimoxazole (41.9%). Fifty percent of the E. coli strains (31 strains) were found to be multiple resistant. Eight (12.9%) out of 62 strains were found to be ESBL positive. Statistically significant relationships were found between the absence of usp and AMP - SXT resistance, iroN and OFX - CIP resistance, PAI and SXT resistance, cnf1 and AMP resistance, and a significant relationship was also found between the presence of the afa and OFX resistance. No difference between E. coli strains isolated from two different clinical presentations was found in terms of virulence genes and antibiotic susceptibility.

  6. Virulence Factors of Aeromonas hydrophila: in the Wake of Reclassification

    Directory of Open Access Journals (Sweden)

    Cody R Rasmussen-Ivey

    2016-08-01

    Full Text Available The ubiquitous jack-of-all-trades, Aeromonas hydrophila, is a freshwater, Gram-negative bacterial pathogen under revision in regard to its phylogenetic and functional affiliation with other aeromonads. While virulence factors are expectedly diverse across A. hydrophila strains and closely related species, our mechanistic knowledge of the vast majority of these factors is based on the molecular characterization of the strains A. hydrophila AH-3 and SSU, which were reclassified as A. piscicola AH-3 in 2009 and A. dhakensis SSU in 2013. Individually, these reclassifications raise important questions involving the applicability of previous research on A. hydrophila virulence mechanisms; however, this issue is exacerbated by a lack of genomic data on other research strains. Collectively, these changes represent a fundamental gap in the literature on A. hydrophila and confirm the necessity of biochemical, molecular, and morphological techniques in the classification of research strains that are used as a foundation for future research. This review revisits what is known about virulence in A. hydrophila and the feasibility of using comparative genomics in light of this phylogenetic revision. Conflicting data between virulence factors, secretion systems, quorum sensing, and their effect on A. hydrophila pathogenicity appears to be an artifact of inappropriate taxonomic comparisons and/or be due to the fact that these properties are strain-specific. This review audits emerging data on dominant virulence factors that are present in both A. dhakensis and A. hydrophila in order to synthesize existing data with the aim of locating where future research is needed.

  7. A unified framework for diversity gradients : The adaptive trait continuum

    NARCIS (Netherlands)

    Carnicer, Jofre; Stefanescu, Constanti; Vila, Roger; Dinca, Vlad; Font, Xavier; Penuelas, Josep

    Aim Adaptive trait continua are axes of covariation observed in multivariate trait data for a given taxonomic group. These continua quantify and summarize life-history variation at the inter-specific level in multi-specific assemblages. Here we examine whether trait continua can provide a useful

  8. A novel anti-virulence gene revealed by proteomic analysis in Shigella flexneri 2a

    Directory of Open Access Journals (Sweden)

    Ying Tianyi

    2010-06-01

    Full Text Available Abstract Background Shigella flexneri is a gram-negative, facultative pathogen that causes the majority of communicable bacterial dysenteries in developing countries. The virulence factors of S. flexneri have been shown to be produced at 37 degrees C but not at 30 degrees C. To discover potential, novel virulence-related proteins of S. flexneri, we performed differential in-gel electrophoresis (DIGE analysis to measure changes in the expression profile that are induced by a temperature increase. Results The ArgT protein was dramatically down-regulated at 37 degrees C. In contrast, the ArgT from the non-pathogenic E. coli did not show this differential expression as in S. flexneri, which suggested that argT might be a potential anti-virulence gene. Competitive invasion assays in HeLa cells and in BALB/c mice with argT mutants were performed, and the results indicated that the over-expression of ArgTY225D would attenuate the virulence of S. flexneri. A comparative proteomic analysis was subsequently performed to investigate the effects of ArgT in S. flexneri at the molecular level. We show that HtrA is differentially expressed among different derivative strains. Conclusion Gene argT is a novel anti-virulence gene that may interfere with the virulence of S. flexneri via the transport of specific amino acids or by affecting the expression of the virulence factor, HtrA.

  9. Phages can constrain protist predation-driven attenuation of Pseudomonas aeruginosa virulence in multienemy communities

    Science.gov (United States)

    Friman, Ville-Petri; Buckling, Angus

    2014-01-01

    The coincidental theory of virulence predicts that bacterial pathogenicity could be a by-product of selection by natural enemies in environmental reservoirs. However, current results are ambiguous and the simultaneous impact of multiple ubiquitous enemies, protists and phages on virulence evolution has not been investigated previously. Here we tested experimentally how Tetrahymena thermophila protist predation and PNM phage parasitism (bacteria-specific virus) alone and together affect the evolution of Pseudomonas aeruginosa PAO1 virulence, measured in wax moth larvae. Protist predation selected for small colony types, both in the absence and presence of phage, which showed decreased edibility to protists, reduced growth in the absence of enemies and attenuated virulence. Although phage selection alone did not affect the bacterial phenotype, it weakened protist-driven antipredatory defence (biofilm formation), its associated pleiotropic growth cost and the correlated reduction in virulence. These results suggest that protist selection can be a strong coincidental driver of attenuated bacterial virulence, and that phages can constrain this effect owing to effects on population dynamics and conflicting selection pressures. Attempting to define causal links such as these might help us to predict the cold and hot spots of coincidental virulence evolution on the basis of microbial community composition of environmental reservoirs. PMID:24671085

  10. Invasive mold infections : virulence and pathogenesis of mucorales

    OpenAIRE

    Morace, G.; Borghi, E.

    2012-01-01

    Mucorales have been increasingly reported as cause of invasive fungal infections in immunocompromised subjects, particularly in patients with haematological malignancies or uncontrolled diabetes mellitus and in those under deferoxamine treatment or undergoing dialysis. The disease often leads to a fatal outcome, but the pathogenesis of the infection is still poorly understood as well as the role of specific virulence determinants and the interaction with the host immune system. Members of the...

  11. Anaerobiosis induced virulence of Salmonella typhi

    DEFF Research Database (Denmark)

    Kapoor, Sarika; Singh, R D; Sharma, P C

    2002-01-01

    , we examined the effect of anaerobiosis on the virulence of Salmonella Typhi, a Gram negative bacteria which invades through the gut mucosa and is responsible for typhoid fever. METHODS: Salmonella Typhi (ty2) was cultured in aerobic and anaerobic conditions to compare its virulence by rabbit ileal...

  12. Production Of Some Virulence Factors Under Different Growth ...

    African Journals Online (AJOL)

    Production Of Some Virulence Factors Under Different Growth Conditions And Antibiotic Susceptibility Pattern Of ... Animal Research International ... Keywords: Virulence, Haemolytic activity, Susceptibility, Antibiotics, Aeromonas hydrophila

  13. Predicting workload profiles of brain-robot interface and electromygraphic neurofeedback with cortical resting-state networks: personal trait or task-specific challenge?

    Science.gov (United States)

    Fels, Meike; Bauer, Robert; Gharabaghi, Alireza

    2015-08-01

    Objective. Novel rehabilitation strategies apply robot-assisted exercises and neurofeedback tasks to facilitate intensive motor training. We aimed to disentangle task-specific and subject-related contributions to the perceived workload of these interventions and the related cortical activation patterns. Approach. We assessed the perceived workload with the NASA Task Load Index in twenty-one subjects who were exposed to two different feedback tasks in a cross-over design: (i) brain-robot interface (BRI) with haptic/proprioceptive feedback of sensorimotor oscillations related to motor imagery, and (ii) control of neuromuscular activity with feedback of the electromyography (EMG) of the same hand. We also used electroencephalography to examine the cortical activation patterns beforehand in resting state and during the training session of each task. Main results. The workload profile of BRI feedback differed from EMG feedback and was particularly characterized by the experience of frustration. The frustration level was highly correlated across tasks, suggesting subject-related relevance of this workload component. Those subjects who were specifically challenged by the respective tasks could be detected by an interhemispheric alpha-band network in resting state before the training and by their sensorimotor theta-band activation pattern during the exercise. Significance. Neurophysiological profiles in resting state and during the exercise may provide task-independent workload markers for monitoring and matching participants’ ability and task difficulty of neurofeedback interventions.

  14. Overlapping and disease specific trait, response, and reflection impulsivity in adolescents with first-episode schizophrenia spectrum disorders or attention-deficit/hyperactivity disorder

    DEFF Research Database (Denmark)

    Jepsen, J. R.M.; Rydkjaer, J.; Fagerlund, B.

    2018-01-01

    and Schizophrenia for School-aged Children – Present and Lifetime Version. Subjects with early-onset, first-episode schizophrenia spectrum disorders (EOS) (N = 29) or ADHD (N = 29) and healthy controls (N = 45) were compared on two performance measures (Information Sampling Task, Stop Signal Task) and a subjective......Background: Schizophrenia and attention-deficit/hyperactivity disorder (ADHD) are developmental disorders with shared clinical characteristics such as cognitive impairments and impulsivity. Impulsivity is a core feature of ADHD and an important factor in aggression, violence, and substance use...... in schizophrenia. Based on the hypothesis that schizophrenia and ADHD represent a continuum of neurodevelopmental impairments, the aim was to identify overlapping and disease specific forms of impulsivity. Methods: Adolescents between 12 and 17 years of age were assessed with the Schedule for Affective Disorders...

  15. Whole-Genome Analysis of Three Yeast Strains Used for Production of Sherry-Like Wines Revealed Genetic Traits Specific to Flor Yeasts

    Science.gov (United States)

    Eldarov, Mikhail A.; Beletsky, Alexey V.; Tanashchuk, Tatiana N.; Kishkovskaya, Svetlana A.; Ravin, Nikolai V.; Mardanov, Andrey V.

    2018-01-01

    Flor yeast strains represent a specialized group of Saccharomyces cerevisiae yeasts used for biological wine aging. We have sequenced the genomes of three flor strains originated from different geographic regions and used for production of sherry-like wines in Russia. According to the obtained phylogeny of 118 yeast strains, flor strains form very tight cluster adjacent to the main wine clade. SNP analysis versus available genomes of wine and flor strains revealed 2,270 genetic variants in 1,337 loci specific to flor strains. Gene ontology analysis in combination with gene content evaluation revealed a complex landscape of possibly adaptive genetic changes in flor yeast, related to genes associated with cell morphology, mitotic cell cycle, ion homeostasis, DNA repair, carbohydrate metabolism, lipid metabolism, and cell wall biogenesis. Pangenomic analysis discovered the presence of several well-known “non-reference” loci of potential industrial importance. Events of gene loss included deletions of asparaginase genes, maltose utilization locus, and FRE-FIT locus involved in iron transport. The latter in combination with a flor-yeast-specific mutation in the Aft1 transcription factor gene is likely to be responsible for the discovered phenotype of increased iron sensitivity and improved iron uptake of analyzed strains. Expansion of the coding region of the FLO11 flocullin gene and alteration of the balance between members of the FLO gene family are likely to positively affect the well-known propensity of flor strains for velum formation. Our study provides new insights in the nature of genetic variation in flor yeast strains and demonstrates that different adaptive properties of flor yeast strains could have evolved through different mechanisms of genetic variation. PMID:29867869

  16. Cell Density Control of Staphylococcal Virulence Mediated by an Octapeptide Pheromone

    Science.gov (United States)

    Ji, Guangyong; Beavis, Ronald C.; Novick, Richard P.

    1995-12-01

    Some bacterial pathogens elaborate and secrete virulence factors in response to environmental signals, others in response to a specific host product, and still others in response to no discernible cue. In this study, we have demonstrated that the synthesis of Staphylococcus aureus virulence factors is controlled by a density-sensing system that utilizes an octapeptide produced by the organism itself. The octapeptide activates expression of the agr locus, a global regulator of the virulence response. This response involves the reciprocal regulation of genes encoding surface proteins and those encoding secreted virulence factors. As cells enter the postexponential phase, surface protein genes are repressed by agr and secretory protein genes are subsequently activated. The intracellular agr effector is a regulatory RNA, RNAIII, whose transcription is activated by an agr-encoded signal transduction system for which the octapeptide is the ligand.

  17. Construction of a high-density genetic map using specific length amplified fragment markers and identification of a quantitative trait locus for anthracnose resistance in walnut (Juglans regia L.).

    Science.gov (United States)

    Zhu, Yufeng; Yin, Yanfei; Yang, Keqiang; Li, Jihong; Sang, Yalin; Huang, Long; Fan, Shu

    2015-08-18

    Walnut (Juglans regia, 2n = 32, approximately 606 Mb per 1C genome) is an economically important tree crop. Resistance to anthracnose, caused by Colletotrichum gloeosporioides, is a major objective of walnut genetic improvement in China. The recently developed specific length amplified fragment sequencing (SLAF-seq) is an efficient strategy that can obtain large numbers of markers with sufficient sequence information to construct high-density genetic maps and permits detection of quantitative trait loci (QTLs) for molecular breeding. SLAF-seq generated 161.64 M paired-end reads. 153,820 SLAF markers were obtained, of which 49,174 were polymorphic. 13,635 polymorphic markers were sorted into five segregation types and 2,577 markers of them were used to construct genetic linkage maps: 2,395 of these fell into 16 linkage groups (LGs) for the female map, 448 markers for the male map, and 2,577 markers for the integrated map. Taking into account the size of all LGs, the marker coverage was 2,664.36 cM for the female map, 1,305.58 cM for the male map, and 2,457.82 cM for the integrated map. The average intervals between two adjacent mapped markers were 1.11 cM, 2.91 cM and 0.95 cM for three maps, respectively. 'SNP_only' markers accounted for 89.25% of the markers on the integrated map. Mapping markers contained 5,043 single nucleotide polymorphisms (SNPs) loci, which corresponded to two SNP loci per SLAF marker. According to the integrated map, we used interval mapping (Logarithm of odds, LOD > 3.0) to detect our quantitative trait. One QTL was detected for anthracnose resistance. The interval of this QTL ranged from 165.51 cM to 176.33 cM on LG14, and ten markers in this interval that were above the threshold value were considered to be linked markers to the anthracnose resistance trait. The phenotypic variance explained by each marker ranged from 16.2 to 19.9%, and their LOD scores varied from 3.22 to 4.04. High-density genetic maps for walnut containing 16

  18. Invasive mold infections: virulence and pathogenesis of mucorales.

    Science.gov (United States)

    Morace, Giulia; Borghi, Elisa

    2012-01-01

    Mucorales have been increasingly reported as cause of invasive fungal infections in immunocompromised subjects, particularly in patients with haematological malignancies or uncontrolled diabetes mellitus and in those under deferoxamine treatment or undergoing dialysis. The disease often leads to a fatal outcome, but the pathogenesis of the infection is still poorly understood as well as the role of specific virulence determinants and the interaction with the host immune system. Members of the order Mucorales are responsible of almost all cases of invasive mucormycoses, the majority of the etiological agents belonging to the Mucoraceae family. Mucorales are able to produce various proteins and metabolic products toxic to animals and humans, but the pathogenic role of these potential virulence factors is unknown. The availability of free iron in plasma and tissues is believed to be crucial for the pathogenesis of these mycoses. Vascular invasion and neurotropism are considered common pathogenic features of invasive mucormycoses.

  19. Invasive Mold Infections: Virulence and Pathogenesis of Mucorales

    Directory of Open Access Journals (Sweden)

    Giulia Morace

    2012-01-01

    Full Text Available Mucorales have been increasingly reported as cause of invasive fungal infections in immunocompromised subjects, particularly in patients with haematological malignancies or uncontrolled diabetes mellitus and in those under deferoxamine treatment or undergoing dialysis. The disease often leads to a fatal outcome, but the pathogenesis of the infection is still poorly understood as well as the role of specific virulence determinants and the interaction with the host immune system. Members of the order Mucorales are responsible of almost all cases of invasive mucormycoses, the majority of the etiological agents belonging to the Mucoraceae family. Mucorales are able to produce various proteins and metabolic products toxic to animals and humans, but the pathogenic role of these potential virulence factors is unknown. The availability of free iron in plasma and tissues is believed to be crucial for the pathogenesis of these mycoses. Vascular invasion and neurotropism are considered common pathogenic features of invasive mucormycoses.

  20. Virulence determinants of Moraxella catarrhalis: distribution and considerations for vaccine development.

    Science.gov (United States)

    Blakeway, Luke V; Tan, Aimee; Peak, Ian R A; Seib, Kate L

    2017-10-01

    Moraxella catarrhalis is a human-restricted opportunistic bacterial pathogen of the respiratory mucosa. It frequently colonizes the nasopharynx asymptomatically, but is also an important causative agent of otitis media (OM) in children, and plays a significant role in acute exacerbations of chronic obstructive pulmonary disease (COPD) in adults. As the current treatment options for M. catarrhalis infection in OM and exacerbations of COPD are often ineffective, the development of an efficacious vaccine is warranted. However, no vaccine candidates for M. catarrhalis have progressed to clinical trials, and information regarding the distribution of M. catarrhalis virulence factors and vaccine candidates is inconsistent in the literature. It is largely unknown if virulence is associated with particular strains or subpopulations of M. catarrhalis, or if differences in clinical manifestation can be attributed to the heterogeneous expression of specific M. catarrhalis virulence factors in the circulating population. Further investigation of the distribution of M. catarrhalis virulence factors in the context of carriage and disease is required so that vaccine development may be targeted at relevant antigens that are conserved among disease-causing strains. The challenge of determining which of the proposed M. catarrhalis virulence factors are relevant to human disease is amplified by the lack of a standardized M. catarrhalis typing system to facilitate direct comparisons of worldwide isolates. Here we summarize and evaluate proposed relationships between M. catarrhalis subpopulations and specific virulence factors in the context of colonization and disease, as well as the current methods used to infer these associations.

  1. A polymerase chain reaction assay for detection of virulent and attenuated strains of duck plague virus.

    Science.gov (United States)

    Xie, Liji; Xie, Zhixun; Huang, Li; Wang, Sheng; Huang, Jiaoling; Zhang, Yanfang; Zeng, Tingting; Luo, Sisi

    2017-11-01

    Sequence analysis of duck plague virus (DPV) revealed that there was a 528bp (B fragment) deletion within the UL2 gene of DPV attenuated vaccine strain in comparison with field virulent strains. The finding of gene deletion provides a potential differentiation test between DPV virulent strain and attenuated strain based on their UL2 gene sizes. Thus we developed a polymerase chain reaction (PCR) assay targeting to the DPV UL2 gene for simultaneous detection of DPV virulent strain and attenuated strain, 827bp for virulent strain and 299bp for attenuated strain. This newly developed PCR for DPV was highly sensitive and specific. It detected as low as 100fg of DNA on both DPV virulent and attenuated strains, no same size bands were amplified from other duck viruses including duck paramyxovirus, duck tembusu virus, duck circovirus, Muscovy duck parvovirus, duck hepatitis virus type I, avian influenza virus and gosling plague virus. Therefore, this PCR assay can be used for the rapid, sensitive and specific detection of DPV virulent and attenuated strains affecting ducks. Copyright © 2017. Published by Elsevier B.V.

  2. Macrophage replication screen identifies a novel Francisella hydroperoxide resistance protein involved in virulence.

    Directory of Open Access Journals (Sweden)

    Anna C Llewellyn

    Full Text Available Francisella tularensis is a gram-negative facultative intracellular pathogen and the causative agent of tularemia. Recently, genome-wide screens have identified Francisella genes required for virulence in mice. However, the mechanisms by which most of the corresponding proteins contribute to pathogenesis are still largely unknown. To further elucidate the roles of these virulence determinants in Francisella pathogenesis, we tested whether each gene was required for replication of the model pathogen F. novicida within macrophages, an important virulence trait. Fifty-three of the 224 genes tested were involved in intracellular replication, including many of those within the Francisella pathogenicity island (FPI, validating our results. Interestingly, over one third of the genes identified are annotated as hypothetical, indicating that F. novicida likely utilizes novel virulence factors for intracellular replication. To further characterize these virulence determinants, we selected two hypothetical genes to study in more detail. As predicted by our screen, deletion mutants of FTN_0096 and FTN_1133 were attenuated for replication in macrophages. The mutants displayed differing levels of attenuation in vivo, with the FTN_1133 mutant being the most attenuated. FTN_1133 has sequence similarity to the organic hydroperoxide resistance protein Ohr, an enzyme involved in the bacterial response to oxidative stress. We show that FTN_1133 is required for F. novicida resistance to, and degradation of, organic hydroperoxides as well as resistance to the action of the NADPH oxidase both in macrophages and mice. Furthermore, we demonstrate that F. holarctica LVS, a strain derived from a highly virulent human pathogenic species of Francisella, also requires this protein for organic hydroperoxide resistance as well as replication in macrophages and mice. This study expands our knowledge of Francisella's largely uncharacterized intracellular lifecycle and

  3. The animal model determines the results of Aeromonas virulence factors

    Directory of Open Access Journals (Sweden)

    Alejandro Romero

    2016-10-01

    Full Text Available The selection of an experimental animal model is of great importance in the study of bacterial virulence factors. Here, a bath infection of zebrafish larvae is proposed as an alternative model to study the virulence factors of A. hydrophila. Intraperitoneal infections in mice and trout were compared with bath infections in zebrafish larvae using specific mutants. The great advantage of this model is that bath immersion mimics the natural route of infection, and injury to the tail also provides a natural portal of entry for the bacteria. The implication of T3SS in the virulence of A. hydrophila was analysed using the AH-1::aopB mutant. This mutant was less virulent than the wild-type strain when inoculated into zebrafish larvae, as described in other vertebrates. However, the zebrafish model exhibited slight differences in mortality kinetics only observed using invertebrate models. Infections using the mutant AH-1∆vapA lacking the gene coding for the surface S-layer suggested that this protein was not totally necessary to the bacteria once it was inside the host, but it contributed to the inflammatory response. Only when healthy zebrafish larvae were infected did the mutant produce less mortality than the wild type. Variations between models were evidenced using the AH-1∆rmlB, which lacks the O-antigen lipopolysaccharide (LPS, and the AH-1∆wahD, which lacks the O-antigen LPS and part of the LPS outer-core. Both mutants showed decreased mortality in all of the animal models, but the differences between them were only observed in injured zebrafish larvae, suggesting that residues from the LPS outer core must be important for virulence. The greatest differences were observed using the AH-1ΔFlaB-J (lacking polar flagella and unable to swim and the AH-1::motX (non-motile but producing flagella. They were as pathogenic as the wild-type strain when injected into mice and trout, but no mortalities were registered in zebrafish larvae. This study

  4. Virulence regulation in Staphylococcus aureus: the need for in vivo analysis of virulence factor regulation.

    Science.gov (United States)

    Pragman, Alexa A; Schlievert, Patrick M

    2004-10-01

    Staphylococcus aureus is a pathogenic microorganism that is responsible for a wide variety of clinical infections. These infections can be relatively mild, but serious, life-threatening infections may result from the expression of staphylococcal virulence factors that are coordinated by virulence regulators. Much work has been done to characterize the actions of staphylococcal virulence regulators in broth culture. Recently, several laboratories showed that transcriptional analyses of virulence regulators in in vivo animal models or in human infection did not correlate with transcriptional analyses accomplished in vitro. In describing the differences between in vitro and in vivo transcription of staphylococcal virulence regulators, we hope to encourage investigators to study virulence regulators using infection models whenever possible.

  5. Cytoplasm-predominant Pten associates with increased region-specific brain tyrosine hydroxylase and dopamine D2 receptors in mouse model with autistic traits.

    Science.gov (United States)

    He, Xin; Thacker, Stetson; Romigh, Todd; Yu, Qi; Frazier, Thomas W; Eng, Charis

    2015-01-01

    Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders characterized by impairment in social communication/interaction and inflexible/repetitive behavior. Several lines of evidence support genetic factors as a predominant cause of ASD. Among those autism susceptibility genes that have been identified, the PTEN tumor suppressor gene, initially identified as predisposing to Cowden heritable cancer syndrome, was found to be mutated in a subset of ASD patients with extreme macrocephaly. However, the ASD-relevant molecular mechanism mediating the effect of PTEN mutations remains elusive. We developed a Pten knock-in murine model to study the effects of Pten germline mutations, specifically altering subcellular localization, in ASD. Proteins were isolated from the hemispheres of the male littermates, and Western blots were performed to determine protein expression levels of tyrosine hydroxylase (TH). Immunohistochemical stains were carried out to validate the localization of TH and dopamine D2 receptors (D2R). PC12 cells ectopically expressing either wild-type or missense mutant PTEN were then compared for the differences in TH expression. Mice carrying Pten mutations have high TH and D2R in the striatum and prefrontal cortex. They also have increased phosphorylation of cAMP response element-binding protein (CREB) and TH. Mechanistically, PTEN downregulates TH production in PC12 cells via inhibiting the phosphoinositide 3-kinase (PI3K)/CREB signaling pathway, while PTEN reduces TH phosphorylation via suppressing MAPK pathway. Unlike wild-type PTEN but similar to the mouse knock-in mutant Pten, three naturally occurring missense mutations of PTEN that we previously identified in ASD patients, H93R, F241S, and D252G, were not able to suppress TH when overexpressed in PC12 cells. In addition, two other PTEN missense mutations, C124S (pan phosphatase dead) and G129E (lipid phosphatase dead), failed to suppress TH when ectopically expressed in PC12 cells

  6. Whole Trait Theory

    Science.gov (United States)

    Fleeson, William; Jayawickreme, Eranda

    2014-01-01

    Personality researchers should modify models of traits to include mechanisms of differential reaction to situations. Whole Trait Theory does so via five main points. First, the descriptive side of traits should be conceptualized as density distributions of states. Second, it is important to provide an explanatory account of the Big 5 traits. Third, adding an explanatory account to the Big 5 creates two parts to traits, an explanatory part and a descriptive part, and these two parts should be recognized as separate entities that are joined into whole traits. Fourth, Whole Trait Theory proposes that the explanatory side of traits consists of social-cognitive mechanisms. Fifth, social-cognitive mechanisms that produce Big-5 states should be identified. PMID:26097268

  7. The reciprocal relationship between competition and intraspecific trait variation

    DEFF Research Database (Denmark)

    A Bennett, Jonathan; Riibak, Kersti; Tamme, Riin

    2016-01-01

    competitive dynamics from trait patterns within communities. However, plant traits are frequently plastic in response to competition. This variation is poorly accounted for in trait based studies of competition and community assembly. 2.To explore the relationship between trait responses and competitive...... with larger leaves and lower specific leaf area than their neighbours. Switching to more stress tolerant strategies by increasing root diameter and leaf tissue density also reduced competition. However, dissimilarity in root tissue density also minimized competition, consistent with limiting similarity...... suggest that considering the effect of competition on trait expression is critical to understanding the relationship between traits and community assembly....

  8. Comparative transcriptome analysis of salivary glands of two populations of rice brown planthopper, Nilaparvata lugens, that differ in virulence.

    Directory of Open Access Journals (Sweden)

    Rui Ji

    Full Text Available BACKGROUND: The brown planthopper (BPH, Nilaparvata lugens (Stål, a destructive rice pest in Asia, can quickly overcome rice resistance by evolving new virulent populations. Herbivore saliva plays an important role in plant-herbivore interactions, including in plant defense and herbivore virulence. However, thus far little is known about BPH saliva at the molecular level, especially its role in virulence and BPH-rice interaction. METHODOLOGY/PRINCIPAL FINDINGS: Using cDNA amplification in combination with Illumina short-read sequencing technology, we sequenced the salivary-gland transcriptomes of two BPH populations with different virulence; the populations were derived from rice variety TN1 (TN1 population and Mudgo (M population. In total, 37,666 and 38,451 unigenes were generated from the salivary glands of these populations, respectively. When combined, a total of 43,312 unigenes were obtained, about 18 times more than the number of expressed sequence tags previously identified from these glands. Gene ontology annotations and KEGG orthology classifications indicated that genes related to metabolism, binding and transport were significantly active in the salivary glands. A total of 352 genes were predicted to encode secretory proteins, and some might play important roles in BPH feeding and BPH-rice interactions. Comparative analysis of the transcriptomes of the two populations revealed that the genes related to 'metabolism,' 'digestion and absorption,' and 'salivary secretion' might be associated with virulence. Moreover, 67 genes encoding putative secreted proteins were differentially expressed between the two populations, suggesting these genes may contribute to the change in virulence. CONCLUSIONS/SIGNIFICANCE: This study was the first to compare the salivary-gland transcriptomes of two BPH populations having different virulence traits and to find genes that may be related to this difference. Our data provide a rich molecular resource for

  9. Comparative transcriptome analysis of salivary glands of two populations of rice brown planthopper, Nilaparvata lugens, that differ in virulence.

    Science.gov (United States)

    Ji, Rui; Yu, Haixin; Fu, Qiang; Chen, Hongdan; Ye, Wenfeng; Li, Shaohui; Lou, Yonggen

    2013-01-01

    The brown planthopper (BPH), Nilaparvata lugens (Stål), a destructive rice pest in Asia, can quickly overcome rice resistance by evolving new virulent populations. Herbivore saliva plays an important role in plant-herbivore interactions, including in plant defense and herbivore virulence. However, thus far little is known about BPH saliva at the molecular level, especially its role in virulence and BPH-rice interaction. Using cDNA amplification in combination with Illumina short-read sequencing technology, we sequenced the salivary-gland transcriptomes of two BPH populations with different virulence; the populations were derived from rice variety TN1 (TN1 population) and Mudgo (M population). In total, 37,666 and 38,451 unigenes were generated from the salivary glands of these populations, respectively. When combined, a total of 43,312 unigenes were obtained, about 18 times more than the number of expressed sequence tags previously identified from these glands. Gene ontology annotations and KEGG orthology classifications indicated that genes related to metabolism, binding and transport were significantly active in the salivary glands. A total of 352 genes were predicted to encode secretory proteins, and some might play important roles in BPH feeding and BPH-rice interactions. Comparative analysis of the transcriptomes of the two populations revealed that the genes related to 'metabolism,' 'digestion and absorption,' and 'salivary secretion' might be associated with virulence. Moreover, 67 genes encoding putative secreted proteins were differentially expressed between the two populations, suggesting these genes may contribute to the change in virulence. This study was the first to compare the salivary-gland transcriptomes of two BPH populations having different virulence traits and to find genes that may be related to this difference. Our data provide a rich molecular resource for future functional studies on salivary glands and will be useful for elucidating the

  10. Genome-Wide Transposon Mutagenesis Indicates that Mycobacterium marinum Customizes Its Virulence Mechanisms for Survival and Replication in Different Hosts

    KAUST Repository

    Weerdenburg, Eveline M.; Abdallah, Abdallah; Rangkuti, Farania; Abd El Ghany, Moataz; Otto, Thomas D.; Adroub, Sabir; Molenaar, Douwe; Ummels, Roy; ter Veen, Kars; van Stempvoort, Gunny; van der Sar, Astrid M.; Ali, Shahjahan; Langridge, Gemma C.; Thomson, Nicholas R.; Pain, Arnab; Bitter, Wilbert

    2015-01-01

    the type VII protein secretion system ESX-1, biosynthesis of polyketide lipids, and utilization of sterols. However, we were also able to show that M. marinum contains an even larger set of host-specific virulence determinants, including proteins involved

  11. Exploring potential virulence regulators in Paracoccidioides brasiliensis isolates of varying virulence through quantitative proteomics.

    Science.gov (United States)

    Castilho, Daniele G; Chaves, Alison F A; Xander, Patricia; Zelanis, André; Kitano, Eduardo S; Serrano, Solange M T; Tashima, Alexandre K; Batista, Wagner L

    2014-10-03

    Few virulence factors have been identified for Paracoccidioides brasiliensis, the agent of paracoccidioidomycosis. In this study, we quantitatively evaluated the protein composition of P. brasiliensis in the yeast phase using minimal and rich media to obtain a better understanding of its virulence and to gain new insights into pathogen adaptation strategies. This analysis was performed on two isolates of the Pb18 strain showing distinct infection profiles in B10.A mice. Using liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis, we identified and quantified 316 proteins in minimal medium, 29 of which were overexpressed in virulent Pb18. In rich medium, 29 out of 295 proteins were overexpressed in the virulent fungus. Three proteins were found to be up-regulated in both media, suggesting the potential roles of these proteins in virulence regulation in P. brasiliensis. Moreover, genes up-regulated in virulent Pb18 showed an increase in its expression after the recovery of virulence of attenuated Pb18. Proteins up-regulated in both isolates were grouped according to their functional categories. Virulent Pb18 undergoes metabolic reorganization and increased expression of proteins involved in fermentative respiration. This approach allowed us to identify potential virulence regulators and provided a foundation for achieving a molecular understanding of how Paracoccidioides modulates the host-pathogen interaction to its advantage.

  12. [Virulence and its relationship to antibiotic resistance].

    Science.gov (United States)

    Joly-Guillou, M L

    1998-12-01

    PATHOGENIC ISLANDS: Certain DNA blocks inserted into the chromosome of most Gram negative bacteria originated in pathogens found in plants. VIRULENCE-ANTIBIOTIC INTERACTIONS: During the invasive phase, the bacterial cell covers itself with adhesins which facilitate its adherence to tissues. The bacterial cell produces a fibronectin which protects its defense systems. Antibiotics favor bacterial resistance by increasing the expression of surface adhesins and fibronectin production. PENICILLIN RESISTANT PNEUMOCOCCI: Experimental models have demonstrated that mortality in mice and host resistance to pneumococcal infection are related to the type of capsule and not to antibiotic resistance. QUORUM SENSING: The bacterial inoculum regulates the production of virulence factors in vivo via quorum sensing. This regulation can play an important role in Pseudomonas aeruginosa infections. ACINETOBACTER BAUMANNI VIRULENCE: Long poorly understood, factors favoring A. baumanni virulence appear to result from bacterial production of IROMPs in the extracellular growth medium in response to iron depletion during the exponential growth phase.

  13. Virulence Factors IN Fungi OF Systemic Mycoses

    Directory of Open Access Journals (Sweden)

    KUROKAWA Cilmery Suemi

    1998-01-01

    Full Text Available Pathogenic fungi that cause systemic mycoses retain several factors which allow their growth in adverse conditions provided by the host, leading to the establishment of the parasitic relationship and contributing to disease development. These factors are known as virulence factors which favor the infection process and the pathogenesis of the mycoses. The present study evaluates the virulence factors of pathogenic fungi such as Blastomyces dermatitidis, Coccidioides immitis, Cryptococcus neoformans, Histoplasma capsulatum and Paracoccidioides brasiliensis in terms of thermotolerance, dimorphism, capsule or cell wall components as well as enzyme production. Virulence factors favor fungal adhesion, colonization, dissemination and the ability to survive in hostile environments and elude the immune response mechanisms of the host. Both the virulence factors presented by different fungi and the defense mechanisms provided by the host require action and interaction of complex processes whose knowledge allows a better understanding of the pathogenesis of systemic mycoses.

  14. Traits traded off

    NARCIS (Netherlands)

    Rueffler, Claus

    2006-01-01

    The course of evolution is restricted by constraints. A special type of constraint is a trade-off where different traits are negatively correlated. In this situation a mutant type that shows an improvement in one trait suffers from a decreased performance through another trait. In a fixed fitness

  15. Hunger for iron: the alternative siderophore iron scavenging systems in highly virulent Yersinia.

    Directory of Open Access Journals (Sweden)

    Alexander eRakin

    2012-11-01

    Full Text Available Low molecular weight siderophores are used by many living organisms to scavenge scarcely available ferric iron. Presence of at least a single siderophore-based iron acquisition system is usually acknowledged as a virulence-associated trait and a prerequisite to become an efficient and successful pathogen. Currently it is assumed that yersiniabactin (Ybt is the solely functional endogenous siderophore iron uptake system in highly virulent Yersinia (Yersinia pestis, Y. pseudotuberculosis and Y. enterocolitica biotype 1B. Genes responsible for biosynthesis, transport and regulation of the yersiniabactin (ybt production are clustered on a mobile genetic element, the High Pathogenicity Island (HPI that is responsible for broad dissemination of the ybt genes in Enterobacteriaceae. However, the ybt gene cluster is absent from nearly half of Y. pseudotuberculosis O3 isolates and epidemic Y. pseudotuberculosis O1 isolates responsible for the Far East Scarlet-like Fever. Several potential siderophore-mediated iron uptake gene clusters are documented in Yersinia genomes, however neither of them have been proven to be functional. It has been suggested that at least two siderophores alternative to Ybt may operate in the highly virulent Yersinia pestis / Y. pseudotuberculosis group, and are referred to as pseudochelin (Pch and yersiniachelin (Ych. Furthermore, most sporadic Y. pseudotuberculosis O1 strains possess gene clusters encoding all three iron scavenging systems. Thus, the Ybt system appears not to be the sole endogenous siderophore iron uptake system in the highly virulent yersiniae and may be efficiently substituted and / or supplemented by alternative iron scavenging systems.

  16. A functional gene array for detection of bacterial virulence elements

    Energy Technology Data Exchange (ETDEWEB)

    Jaing, C

    2007-11-01

    We report our development of the first of a series of microarrays designed to detect pathogens with known mechanisms of virulence and antibiotic resistance. By targeting virulence gene families as well as genes unique to specific biothreat agents, these arrays will provide important data about the pathogenic potential and drug resistance profiles of unknown organisms in environmental samples. To validate our approach, we developed a first generation array targeting genes from Escherichia coli strains K12 and CFT073, Enterococcus faecalis and Staphylococcus aureus. We determined optimal probe design parameters for microorganism detection and discrimination, measured the required target concentration, and assessed tolerance for mismatches between probe and target sequences. Mismatch tolerance is a priority for this application, due to DNA sequence variability among members of gene families. Arrays were created using the NimbleGen Maskless Array Synthesizer at Lawrence Livermore National Laboratory. Purified genomic DNA from combinations of one or more of the four target organisms, pure cultures of four related organisms, and environmental aerosol samples with spiked-in genomic DNA were hybridized to the arrays. Based on the success of this prototype, we plan to design further arrays in this series, with the goal of detecting all known virulence and antibiotic resistance gene families in a greatly expanded set of organisms.

  17. Uropathogenic Escherichia coli virulence genes: invaluable approaches for designing DNA microarray probes.

    Science.gov (United States)

    Jahandeh, Nadia; Ranjbar, Reza; Behzadi, Payam; Behzadi, Elham

    2015-01-01

    The pathotypes of uropathogenic Escherichia coli (UPEC) cause different types of urinary tract infections (UTIs). The presence of a wide range of virulence genes in UPEC enables us to design appropriate DNA microarray probes. These probes, which are used in DNA microarray technology, provide us with an accurate and rapid diagnosis and definitive treatment in association with UTIs caused by UPEC pathotypes. The main goal of this article is to introduce the UPEC virulence genes as invaluable approaches for designing DNA microarray probes. Main search engines such as Google Scholar and databases like NCBI were searched to find and study several original pieces of literature, review articles, and DNA gene sequences. In parallel with in silico studies, the experiences of the authors were helpful for selecting appropriate sources and writing this review article. There is a significant variety of virulence genes among UPEC strains. The DNA sequences of virulence genes are fabulous patterns for designing microarray probes. The location of virulence genes and their sequence lengths influence the quality of probes. The use of selected virulence genes for designing microarray probes gives us a wide range of choices from which the best probe candidates can be chosen. DNA microarray technology provides us with an accurate, rapid, cost-effective, sensitive, and specific molecular diagnostic method which is facilitated by designing microarray probes. Via these tools, we are able to have an accurate diagnosis and a definitive treatment regarding UTIs caused by UPEC pathotypes.

  18. Long-distance delivery of bacterial virulence factors by Pseudomonas aeruginosa outer membrane vesicles.

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    Jennifer M Bomberger

    2009-04-01

    Full Text Available Bacteria use a variety of secreted virulence factors to manipulate host cells, thereby causing significant morbidity and mortality. We report a mechanism for the long-distance delivery of multiple bacterial virulence factors, simultaneously and directly into the host cell cytoplasm, thus obviating the need for direct interaction of the pathogen with the host cell to cause cytotoxicity. We show that outer membrane-derived vesicles (OMV secreted by the opportunistic human pathogen Pseudomonas aeruginosa deliver multiple virulence factors, including beta-lactamase, alkaline phosphatase, hemolytic phospholipase C, and Cif, directly into the host cytoplasm via fusion of OMV with lipid rafts in the host plasma membrane. These virulence factors enter the cytoplasm of the host cell via N-WASP-mediated actin trafficking, where they rapidly distribute to specific subcellular locations to affect host cell biology. We propose that secreted virulence factors are not released individually as naked proteins into the surrounding milieu where they may randomly contact the surface of the host cell, but instead bacterial derived OMV deliver multiple virulence factors simultaneously and directly into the host cell cytoplasm in a coordinated manner.

  19. Main functions and taxonomic distribution of virulence genes in Brucella melitensis 16 M.

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    Aniel Jessica Leticia Brambila-Tapia

    Full Text Available Many virulence genes have been detected in attenuated mutants of Brucella melitensis 16 M; nevertheless, a complete report of these genes, including the main Cluster of Orthologous Groups (COG represented as well as the taxonomical distribution among all complete bacterial and archaeal genomes, has not been analyzed. In this work a total of 160 virulence genes that have been reported in attenuated mutants in B. melitensis were included and analyzed. Additionally, we obtained 250 B. melitensis randomly selected genes as a reference group for the taxonomical comparisons. The COGs and the taxonomical distribution profile for 789 nonredundant bacterial and archaeal genomes were obtained and compared with the whole-genome COG distribution and with the 250 randomly selected genes, respectively. The main COGs associated with virulence genes corresponded to the following: intracellular trafficking, secretion and vesicular transport (U; cell motility (N; nucleotide transport and metabolism (F; transcription (K; and cell wall/membrane/envelope biogenesis (M. In addition, we found that virulence genes presented a higher proportion of orthologs in the Euryarchaeota and Proteobacteria phyla, with a significant decrease in Chlamydiae, Bacteroidetes, Tenericutes, Firmicutes and Thermotogae. In conclusion, we found that genes related to specific functions are more relevant to B. melitensis virulence, with the COG U the most significant. Additionally, the taxonomical distribution of virulence genes highlights the importance of these genes in the related Proteobacteria, being less relevant in distant groups of organisms with the exception of Euryarchaeota.

  20. Catabolite and Oxygen Regulation of Enterohemorrhagic Escherichia coli Virulence

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    Kimberly M. Carlson-Banning

    2016-11-01

    Full Text Available The biogeography of the gut is diverse in its longitudinal axis, as well as within specific microenvironments. Differential oxygenation and nutrient composition drive the membership of microbial communities in these habitats. Moreover, enteric pathogens can orchestrate further modifications to gain a competitive advantage toward host colonization. These pathogens are versatile and adept when exploiting the human colon. They expertly navigate complex environmental cues and interkingdom signaling to colonize and infect their hosts. Here we demonstrate how enterohemorrhagic Escherichia coli (EHEC uses three sugar-sensing transcription factors, Cra, KdpE, and FusR, to exquisitely regulate the expression of virulence factors associated with its type III secretion system (T3SS when exposed to various oxygen concentrations. We also explored the effect of mucin-derived nonpreferred carbon sources on EHEC growth and expression of virulence genes. Taken together, the results show that EHEC represses the expression of its T3SS when oxygen is absent, mimicking the largely anaerobic lumen, and activates its T3SS when oxygen is available through Cra. In addition, when EHEC senses mucin-derived sugars heavily present in the O-linked and N-linked glycans of the large intestine, virulence gene expression is initiated. Sugars derived from pectin, a complex plant polysaccharide digested in the large intestine, also increased virulence gene expression. Not only does EHEC sense host- and microbiota-derived interkingdom signals, it also uses oxygen availability and mucin-derived sugars liberated by the microbiota to stimulate expression of the T3SS. This precision in gene regulation allows EHEC to be an efficient pathogen with an extremely low infectious dose.

  1. Metabolic Genetic Screens Reveal Multidimensional Regulation of Virulence Gene Expression in Listeria monocytogenes and an Aminopeptidase That Is Critical for PrfA Protein Activation.

    Science.gov (United States)

    Friedman, Sivan; Linsky, Marika; Lobel, Lior; Rabinovich, Lev; Sigal, Nadejda; Herskovits, Anat A

    2017-06-01

    Listeria monocytogenes is an environmental saprophyte and intracellular bacterial pathogen. Upon invading mammalian cells, the bacterium senses abrupt changes in its metabolic environment, which are rapidly transduced to regulation of virulence gene expression. To explore the relationship between L. monocytogenes metabolism and virulence, we monitored virulence gene expression dynamics across a library of genetic mutants grown under two metabolic conditions known to activate the virulent state: charcoal-treated rich medium containing glucose-1-phosphate and minimal defined medium containing limiting concentrations of branched-chain amino acids (BCAAs). We identified over 100 distinct mutants that exhibit aberrant virulence gene expression profiles, the majority of which mapped to nonessential metabolic genes. Mutants displayed enhanced, decreased, and early and late virulence gene expression profiles, as well as persistent levels, demonstrating a high plasticity in virulence gene regulation. Among the mutants, one was noteworthy for its particularly low virulence gene expression level and mapped to an X-prolyl aminopeptidase (PepP). We show that this peptidase plays a role in posttranslational activation of the major virulence regulator, PrfA. Specifically, PepP mediates recruitment of PrfA to the cytoplasmic membrane, a step identified as critical for PrfA protein activation. This study establishes a novel step in the complex mechanism of PrfA activation and further highlights the cross regulation of metabolism and virulence. Copyright © 2017 American Society for Microbiology.

  2. Outcrossing and crossbreeding recovers deteriorated traits in laboratory cultured Steinernema carpocapsae nematodes.

    Science.gov (United States)

    Chaston, John M; Dillman, Adler R; Shapiro-Ilan, David I; Bilgrami, Anwar L; Gaugler, Randy; Hopper, Keith R; Adams, Byron J

    2011-06-01

    The nematode Steinernema carpocapsae infects and kills many pest insects in agro-ecosystems and is commonly used in biocontrol of these pests. Growth of the nematodes prior to distribution for biocontrol commonly results in deterioration of traits that are essential for nematode persistence in field applications. To better understand the mechanisms underlying trait deterioration of the efficacy of natural parasitism in entomopathogenic nematodes, we explored the maintenance of fitness related traits including reproductive capacity, heat tolerance, virulence to insects and 'tail standing' (formerly called nictation) among laboratory-cultured lines derived from natural, randomly mating populations of S. carpocapsae. Laboratory cultured nematode lines with fitness-related trait values below wild-type levels regained wild-type levels of reproductive and heat tolerance traits when outcrossed with a non-deteriorated line, while virulence and 'tail standing' did not deteriorate in our experiments. Crossbreeding two trait-deteriorated lines with each other also resulted in restoration of trait means to wild-type levels in most crossbred lines. Our results implicate inbreeding depression as the primary cause of trait deterioration in the laboratory cultured S. carpocapsae. We further suggest the possibility of creating inbred lines purged of deleterious alleles as founders in commercial nematode growth. Copyright © 2011 Australian Society for Parasitology Inc. All rights reserved.

  3. Modulation of Replicative Lifespan in Cryptococcus neoformans: Implications for Virulence

    Science.gov (United States)

    Bouklas, Tejas; Jain, Neena; Fries, Bettina C.

    2017-01-01

    The fungal pathogen, Cryptococcus neoformans, has been shown to undergo replicative aging. Old cells are characterized by advanced generational age and phenotypic changes that appear to mediate enhanced resistance to host and antifungal-based killing. As a consequence of this age-associated resilience, old cells accumulate during chronic infection. Based on these findings, we hypothesized that shifting the generational age of a pathogenic yeast population would alter its vulnerability to the host and affect its virulence. SIR2 is a well-conserved histone deacetylase, and a pivotal target for the development of anti-aging drugs. We tested its effect on C. neoformans’ replicative lifespan (RLS). First, a mutant C. neoformans strain (sir2Δ) was generated, and confirmed a predicted shortened RLS in sir2Δ cells consistent with its known role in aging. Next, RLS analysis showed that treatment of C. neoformans with Sir2p-agonists resulted in a significantly prolonged RLS, whereas treatment with a Sir2p-antagonist shortened RLS. RLS modulating effects were dependent on SIR2 and not observed in sir2Δ cells. Because SIR2 loss resulted in a slightly impaired fitness, effects of genetic RLS modulation on virulence could not be compared with wild type cells. Instead we chose to chemically modulate RLS, and investigated the effect of Sir2p modulating drugs on C. neoformans cells in a Galleria mellonella infection model. Consistent with our hypothesis that shifts in the generational age of the infecting yeast population alters its vulnerability to host cells, we observed decreased virulence of C. neoformans in the Galleria host when RLS was prolonged by treatment with Sir2p agonists. In contrast, treatment with a Sir2p antagonist, which shortens RLS enhanced virulence in Galleria. In addition, combination of Sir2p agonists with antifungal therapy enhanced the antifungal’s effect. Importantly, no difference in virulence was observed with drug treatment when sir2Δ cells

  4. Assessing the Utility of Compound Trait Estimates of Narrow Personality Traits.

    Science.gov (United States)

    Credé, Marcus; Harms, Peter D; Blacksmith, Nikki; Wood, Dustin

    2016-01-01

    It has been argued that approximations of narrow traits can be made through linear combinations of broad traits such as the Big Five personality traits. Indeed, Hough and Ones ( 2001 ) used a qualitative analysis of scale content to arrive at a taxonomy of how Big Five traits might be combined to approximate various narrow traits. However, the utility of such compound trait approximations has yet to be established beyond specific cases such as integrity and customer service orientation. Using data from the Eugene-Springfield Community Sample (Goldberg, 2008 ), we explore the ability of linear composites of scores on Big Five traits to approximate scores on 127 narrow trait measures from 5 well-known non-Big-Five omnibus measures of personality. Our findings indicate that individuals' standing on more than 30 narrow traits can be well estimated from 3 different types of linear composites of scores on Big Five traits without a substantial sacrifice in criterion validity. We discuss theoretical accounts for why such relationships exist as well as the theoretical and practical implications of these findings for researchers and practitioners.

  5. A Multidimensional Measure of Trait Anxiety: The S-R Inventory of General Trait Anxiousness

    Science.gov (United States)

    Endler, Norman S.; Okada, Marilyn

    1975-01-01

    The S-R Inventory of General Trait Anxiousness was administered to samples of normal youth, normal adult, neurotic, and psychotic subjects. The practical and theoretical uses of the inventory are discussed, and it is specifically indicated how the inventory could be used to extend the Speilberger state-trait anxiety theory. (Author)

  6. Towards a reference plant trait ontology for modeling knowledge of plant traits and phenotypes

    Science.gov (United States)

    Ontology engineering and knowledge modeling for the plant sciences is expected to contribute to the understanding of the basis of plant traits that determine phenotypic expression in a given environment. Several crop- or clade-specific plant trait ontologies have been developed to describe plant tr...

  7. New Insight into Biofilm Formation Ability, the Presence of Virulence Genes and Probiotic Potential of Enterococcus sp. Dairy Isolates

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    Nikola Popović

    2018-01-01

    Full Text Available Enterococci have controversial status due to their emerging role in nosocomial infections and transmission of antibiotic resistance genes, while some enterococci strains are used as probiotics for humans and animals and starter cultures in dairy industry. In order to improve our understanding of factors involved in the safe use of enterococci as potential probiotics, the antibiotic susceptibility, virulence and probiotic traits of 75 dairy enterococci isolates belonging to Enterococcus durans (50, En. faecium (15, En. faecalis (6, En. italicus (3, and En. hirae (1 were evaluated. The results revealed that ciprofloxacin resistance and biofilm formation are correlated with isolates originated from Golija mountain (Serbia, while gelatinase activity was more common in isolates from Prigorje region (Croatia, pointing to uncontrolled use of antibiotics and anthropogenic impact on dairy products' microbiota in these regions. The virulence genes were sporadically present in 13 selected dairy enterococci isolates. Interestingly, biofilm formation was correlated with higher ability of strains to reduce the adhesion of E. coli and Salmonella Enteritidis to HT29-MTX cells. To our knowledge this is the first study reporting the presence of the esp gene (previously correlated with pathogenesis in dairy enterococci isolates, mostly associated with the genes involved in adhesion property. Hence, the results of this study revealed that the virulence genes are sporadically present in dairy isolates and more correlated to adhesion properties and biofilm formation, implicating their role in gut colonization rather than to the virulence traits.

  8. Comparative genome analysis of 24 bovine-associated Staphylococcus isolates with special focus on the putative virulence genes

    Science.gov (United States)

    Åvall-Jääskeläinen, Silja; Paulin, Lars; Blom, Jochen

    2018-01-01

    Non-aureus staphylococci (NAS) are most commonly isolated from subclinical mastitis. Different NAS species may, however, have diverse effects on the inflammatory response in the udder. We determined the genome sequences of 20 staphylococcal isolates from clinical or subclinical bovine mastitis, belonging to the NAS species Staphylococcus agnetis, S. chromogenes, and S. simulans, and focused on the putative virulence factor genes present in the genomes. For comparison we used our previously published genome sequences of four S. aureus isolates from bovine mastitis. The pan-genome and core genomes of the non-aureus isolates were characterized. After that, putative virulence factor orthologues were searched in silico. We compared the presence of putative virulence factors in the NAS species and S. aureus and evaluated the potential association between bacterial genotype and type of mastitis (clinical vs. subclinical). The NAS isolates had much less virulence gene orthologues than the S. aureus isolates. One third of the virulence genes were detected only in S. aureus. About 100 virulence genes were present in all S. aureus isolates, compared to about 40 to 50 in each NAS isolate. S. simulans differed the most. Several of the virulence genes detected among NAS were harbored only by S. simulans, but it also lacked a number of genes present both in S. agnetis and S. chromogenes. The type of mastitis was not associated with any specific virulence gene profile. It seems that the virulence gene profiles or cumulative number of different virulence genes are not directly associated with the type of mastitis (clinical or subclinical), indicating that host derived factors such as the immune status play a pivotal role in the manifestation of mastitis. PMID:29610707

  9. Comparative genome analysis of 24 bovine-associated Staphylococcus isolates with special focus on the putative virulence genes

    Directory of Open Access Journals (Sweden)

    Silja Åvall-Jääskeläinen

    2018-03-01

    Full Text Available Non-aureus staphylococci (NAS are most commonly isolated from subclinical mastitis. Different NAS species may, however, have diverse effects on the inflammatory response in the udder. We determined the genome sequences of 20 staphylococcal isolates from clinical or subclinical bovine mastitis, belonging to the NAS species Staphylococcus agnetis, S. chromogenes, and S. simulans, and focused on the putative virulence factor genes present in the genomes. For comparison we used our previously published genome sequences of four S. aureus isolates from bovine mastitis. The pan-genome and core genomes of the non-aureus isolates were characterized. After that, putative virulence factor orthologues were searched in silico. We compared the presence of putative virulence factors in the NAS species and S. aureus and evaluated the potential association between bacterial genotype and type of mastitis (clinical vs. subclinical. The NAS isolates had much less virulence gene orthologues than the S. aureus isolates. One third of the virulence genes were detected only in S. aureus. About 100 virulence genes were present in all S. aureus isolates, compared to about 40 to 50 in each NAS isolate. S. simulans differed the most. Several of the virulence genes detected among NAS were harbored only by S. simulans, but it also lacked a number of genes present both in S. agnetis and S. chromogenes. The type of mastitis was not associated with any specific virulence gene profile. It seems that the virulence gene profiles or cumulative number of different virulence genes are not directly associated with the type of mastitis (clinical or subclinical, indicating that host derived factors such as the immune status play a pivotal role in the manifestation of mastitis.

  10. Relating Stomatal Conductance to Leaf Functional Traits.

    Science.gov (United States)

    Kröber, Wenzel; Plath, Isa; Heklau, Heike; Bruelheide, Helge

    2015-10-12

    Leaf functional traits are important because they reflect physiological functions, such as transpiration and carbon assimilation. In particular, morphological leaf traits have the potential to summarize plants strategies in terms of water use efficiency, growth pattern and nutrient use. The leaf economics spectrum (LES) is a recognized framework in functional plant ecology and reflects a gradient of increasing specific leaf area (SLA), leaf nitrogen, phosphorus and cation content, and decreasing leaf dry matter content (LDMC) and carbon nitrogen ratio (CN). The LES describes different strategies ranging from that of short-lived leaves with high photosynthetic capacity per leaf mass to long-lived leaves with low mass-based carbon assimilation rates. However, traits that are not included in the LES might provide additional information on the species' physiology, such as those related to stomatal control. Protocols are presented for a wide range of leaf functional traits, including traits of the LES, but also traits that are independent of the LES. In particular, a new method is introduced that relates the plants' regulatory behavior in stomatal conductance to vapor pressure deficit. The resulting parameters of stomatal regulation can then be compared to the LES and other plant functional traits. The results show that functional leaf traits of the LES were also valid predictors for the parameters of stomatal regulation. For example, leaf carbon concentration was positively related to the vapor pressure deficit (vpd) at the point of inflection and the maximum of the conductance-vpd curve. However, traits that are not included in the LES added information in explaining parameters of stomatal control: the vpd at the point of inflection of the conductance-vpd curve was lower for species with higher stomatal density and higher stomatal index. Overall, stomata and vein traits were more powerful predictors for explaining stomatal regulation than traits used in the LES.

  11. Towards a unified model for leaf trait and trait-environment relationships

    Science.gov (United States)

    Wang, H.; Harrison, S. P.; Prentice, I. C.; Peng, C.; Yang, Y.

    2016-12-01

    A widely accepted core set of leaf traits describes key aspects of plant function including the coupling among carbon, nitrogen and water cycles at the leaf, plant and ecosystem scales. Our current research focuses on two questions: (1) what dimensions of correlated variation among traits apply across all vascular plants irrespective of environment; (2) how, and to what extent, can variations in community mean values of leaf traits be predicted along environmental gradients? Based on a large quantitative trait data set covering the major environmental gradients across China, we are tackling these questions via two complementary approaches: multivariate analysis of trait-trait, trait-site, and trait-environment relationships, and the development of conceptual models and testable hypotheses for the dependencies of each trait on other traits and/or specific environmental predictors. Preliminary multivariate analyses suggest the existence of at least two independent axes of variation in leaf traits, and show robust relationships between trait syndromes and growing-season climate variables. A minimal conceptual model then considers nitrogen per unit leaf area (Narea) as a function of leaf mass per unit area (LMA) and carboxylation capacity (Vcmax); LMA as a function of irradiance, temperature and water and/or nutrient stress; Vcmax as a function of irradiance, temperature and the long-term ci:ca ratio (indexed by δ13C); and the ci:ca ratio as a function of vapour pressure deficit, temperature and atmospheric pressure. Each of these dependencies has support from observations, pointing the way towards a comprehensive set of equations to predict community-mean values of core traits in next-generation terrestrial ecosystem models.

  12. Global Land Carbon Uptake from Trait Distributions

    Science.gov (United States)

    Butler, E. E.; Datta, A.; Flores-Moreno, H.; Fazayeli, F.; Chen, M.; Wythers, K. R.; Banerjee, A.; Atkin, O. K.; Kattge, J.; Reich, P. B.

    2016-12-01

    Historically, functional diversity in land surface models has been represented through a range of plant functional types (PFTs), each of which has a single value for all of its functional traits. Here we expand the diversity of the land surface by using a distribution of trait values for each PFT. The data for these trait distributions is from a sub-set of the global database of plant traits, TRY, and this analysis uses three leaf traits: mass based nitrogen and phosphorus content and specific leaf area, which influence both photosynthesis and respiration. The data are extrapolated into continuous surfaces through two methodologies. The first, a categorical method, classifies the species observed in TRY into satellite estimates of their plant functional type abundances - analogous to how traits are currently assigned to PFTs in land surface models. Second, a Bayesian spatial method which additionally estimates how the distribution of a trait changes in accord with both climate and soil covariates. These two methods produce distinct patterns of diversity which are incorporated into a land surface model to estimate how the range of trait values affects the global land carbon budget.

  13. Expression of parasite genetic variation changes over the course of infection: implications of within-host dynamics for the evolution of virulence.

    Science.gov (United States)

    Clerc, Melanie; Ebert, Dieter; Hall, Matthew D

    2015-04-07

    How infectious disease agents interact with their host changes during the course of infection and can alter the expression of disease-related traits. Yet by measuring parasite life-history traits at one or few moments during infection, studies have overlooked the impact of variable parasite growth trajectories on disease evolution. Here we show that infection-age-specific estimates of host and parasite fitness components can reveal new insight into the evolution of parasites. We do so by characterizing the within-host dynamics over an entire infection period for five genotypes of the castrating bacterial parasite Pasteuria ramosa infecting the crustacean Daphnia magna. Our results reveal that genetic variation for parasite-induced gigantism, host castration and parasite spore loads increases with the age of infection. Driving these patterns appears to be variation in how well the parasite maintains control of host reproduction late in the infection process. We discuss the evolutionary consequences of this finding with regard to natural selection acting on different ages of infection and the mechanism underlying the maintenance of castration efficiency. Our results highlight how elucidating within-host dynamics can shed light on the selective forces that shape infection strategies and the evolution of virulence. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  14. Restriction of Rift Valley Fever Virus Virulence in Mosquito Cells

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    Sonja R. Gerrard

    2010-02-01

    Full Text Available Arboviruses are maintained in a natural cycle that requires blood-sucking arthropod and vertebrate hosts. Arboviruses are believed to persistently infect their arthropod host without overt pathology and cause acute infection with viremia in their vertebrate host. We have focused on elucidating how a specific arbovirus, Rift Valley fever (RVF virus, causes cytopathic effect in cells derived from vertebrates and non-cytopathic infection in cells derived from arthropods. We demonstrate that the vertebrate virulence factor, NSs, is functional in arthropod cells but is expressed at significantly lower levels in infected arthropod versus infected vertebrate cells.

  15. Attenuation of Pseudomonas aeruginosa virulence by quorum sensing inhibitors

    DEFF Research Database (Denmark)

    Hentzer, Morten; Wu, H.; Andersen, Jens Bo

    2003-01-01

    Traditional treatment of infectious diseases is based on compounds that kill or inhibit growth of bacteria. A major concern with this approach is the frequent development of resistance to antibiotics. The discovery of communication systems (quorum sensing systems) regulating bacterial virulence has...... of natural furanone compounds can act as a potent antagonist of bacterial quorum sensing. We employed GeneChip((R)) microarray technology to identify furanone target genes and to map the quorum sensing regulon. The transcriptome analysis showed that the furanone drug specifically targeted quorum sensing...

  16. Virulence meets metabolism: Cra and KdpE gene regulation in enterohemorrhagic Escherichia coli.

    Science.gov (United States)

    Njoroge, Jacqueline W; Nguyen, Y; Curtis, Meredith M; Moreira, Cristiano G; Sperandio, Vanessa

    2012-10-16

    , which causes bloody diarrhea, these two proteins influence important virulence traits. We also propose that their control of one or more of these virulence traits is due to the direct interaction of the Cra and KdpE proteins with each other, as well as with their DNA targets. This work shows how EHEC coopts established mechanisms for sensing the metabolites and stress cues in the environment, to induce virulence factors in a temporal and energy-efficient manner, culminating in disease. Understanding how pathogens commandeer nonpathogenic systems can help us develop measures to control them.

  17. A cell-cell signaling sensor is required for virulence and insect transmission of Xylella fastidiosa.

    Science.gov (United States)

    Chatterjee, Subhadeep; Wistrom, Christina; Lindow, Steven E

    2008-02-19

    Cell-cell signaling in Xylella fastidiosa, a xylem-colonizing plant pathogenic bacterium, mediated by a fatty acid Diffusible Signaling Factor (DSF), is required to colonize insect vectors and to suppress virulence to grape. Here, we show that a hybrid two-component regulatory protein RpfC is involved in negative regulation of DSF synthesis by RpfF in X. fastidiosa. X. fastidiosa rpfC mutants hyperexpress rpfF and overproduce DSF and are deficient in virulence and movement in the xylem vessels of grape. The expression of the genes encoding the adhesins FimA, HxfA, and HxfB is much higher in rpfC mutants, which also exhibit a hyperattachment phenotype in culture that is associated with their inability to migrate in xylem vessels and cause disease. rpfF mutants deficient in DSF production have the opposite phenotypes for all of these traits. RpfC is also involved in the regulation of other signaling components including rpfG, rpfB, a GGDEF domain protein that may be involved in intracellular signaling by modulating the levels of cyclic-di-GMP, and the virulence factors tolC and pglA required for disease. rpfC mutants are able to colonize the mouthparts of insect vectors and wild-type strains but are not transmitted as efficiently to new host plants, apparently because of their high levels of adhesiveness. Because of the conflicting contributions of adhesiveness and other traits to movement within plants and vectoring to new host plants, X. fastidiosa apparently coordinates these traits in a population-size-dependent fashion involving accumulation of DSF.

  18. Uropathogenic Escherichia coli pathogenicity islands and other ExPEC virulence genes may contribute to the genome variability of enteroinvasive E. coli.

    Science.gov (United States)

    da Silva, Laís Cristina; de Mello Santos, Ana Carolina; Silva, Rosa Maria

    2017-03-16

    Enteroinvasive Escherichia coli (EIEC) may be the causative agent of part of those million cases of diarrhea illness reported worldwide every year and attributable to Shigella. That is because both enteropathogens have many common characteristics that difficult their identification either by traditional microbiological methods or by molecular tools used in the clinical laboratory settings. While Shigella has been extensively studied, EIEC remains barely characterized at the molecular level. Recent EIEC important outbreaks, apparently generating more life-threatening cases, have prompted us to screen EIEC for virulence traits usually related to extraintestinal pathogenic E. coli (ExPEC). That could explain the appearance of EIEC strains presenting higher virulence potential. EIEC strains were distributed mainly in three phylogroups in a serogroup-dependent manner. Serogroups O124, O136, O144, and O152 were exclusively classified in phylogroup A; O143 in group E; and O28ac and O29 in group B1. Only two serogroups showed diverse phylogenetic origin as follows: O164 was assigned to groups A, B1, C, and B2 (one strain each), and O167 in groups E (five strains), and A (one strain) (Table 1). Eleven of 20 virulence genes (VGs) searched were detected, and the majority of the 19 different VGs combinations found were serogroup-specific. Uropathogenic E. coli (UPEC) PAI genetic markers were detected in all EIEC strains. PAIs I J96 and II CFT073 were the most frequent (92.1 and 80.4%, respectively). PAI IV 536 was restricted to some serogroups from phylogroups A, B1 and E. PAI I CFT073 was uniquely detected in phylogroups B2 and E. A total of 45 (88%) strains presented multiple PAI markers (two to four). PAIs I J96 and II CFT073 were found together in 80% of strains. EIEC is a DEC pathovar that presents VGs and pathogenicity island genetic markers typically associated with ExPEC, especially UPEC. These features are distributed in a phylogenetic and serogroup-dependent manner

  19. Transcriptome analysis of fat bodies from two brown planthopper (Nilaparvata lugens populations with different virulence levels in rice.

    Directory of Open Access Journals (Sweden)

    Haixin Yu

    Full Text Available BACKGROUND: The brown planthopper (BPH, Nilaparvata lugens (Stål, one of the most serious rice insect pests in Asia, can quickly overcome rice resistance by evolving new virulent populations. The insect fat body plays essential roles in the life cycles of insects and in plant-insect interactions. However, whether differences in fat body transcriptomes exist between insect populations with different virulence levels and whether the transcriptomic differences are related to insect virulence remain largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we performed transcriptome-wide analyses on the fat bodies of two BPH populations with different virulence levels in rice. The populations were derived from rice variety TN1 (TN1 population and Mudgo (M population. In total, 33,776 and 32,332 unigenes from the fat bodies of TN1 and M populations, respectively, were generated using Illumina technology. Gene ontology annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG orthology classifications indicated that genes related to metabolism and immunity were significantly active in the fat bodies. In addition, a total of 339 unigenes showed homology to genes of yeast-like symbionts (YLSs from 12 genera and endosymbiotic bacteria Wolbachia. A comparative analysis of the two transcriptomes generated 7,860 differentially expressed genes. GO annotations and enrichment analysis of KEGG pathways indicated these differentially expressed transcripts might be involved in metabolism and immunity. Finally, 105 differentially expressed genes from YLSs and Wolbachia were identified, genes which might be associated with the formation of different virulent populations. CONCLUSIONS/SIGNIFICANCE: This study was the first to compare the fat-body transcriptomes of two BPH populations having different virulence traits and to find genes that may be related to this difference. Our findings provide a molecular resource for future investigations of fat bodies

  20. Transcriptome Analysis of Fat Bodies from Two Brown Planthopper (Nilaparvata lugens) Populations with Different Virulence Levels in Rice

    Science.gov (United States)

    Chen, Hongdan; Lai, Wenxiang; Fu, Qiang; Lou, Yonggen

    2014-01-01

    Background The brown planthopper (BPH), Nilaparvata lugens (Stål), one of the most serious rice insect pests in Asia, can quickly overcome rice resistance by evolving new virulent populations. The insect fat body plays essential roles in the life cycles of insects and in plant-insect interactions. However, whether differences in fat body transcriptomes exist between insect populations with different virulence levels and whether the transcriptomic differences are related to insect virulence remain largely unknown. Methodology/Principal Findings In this study, we performed transcriptome-wide analyses on the fat bodies of two BPH populations with different virulence levels in rice. The populations were derived from rice variety TN1 (TN1 population) and Mudgo (M population). In total, 33,776 and 32,332 unigenes from the fat bodies of TN1 and M populations, respectively, were generated using Illumina technology. Gene ontology annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology classifications indicated that genes related to metabolism and immunity were significantly active in the fat bodies. In addition, a total of 339 unigenes showed homology to genes of yeast-like symbionts (YLSs) from 12 genera and endosymbiotic bacteria Wolbachia. A comparative analysis of the two transcriptomes generated 7,860 differentially expressed genes. GO annotations and enrichment analysis of KEGG pathways indicated these differentially expressed transcripts might be involved in metabolism and immunity. Finally, 105 differentially expressed genes from YLSs and Wolbachia were identified, genes which might be associated with the formation of different virulent populations. Conclusions/Significance This study was the first to compare the fat-body transcriptomes of two BPH populations having different virulence traits and to find genes that may be related to this difference. Our findings provide a molecular resource for future investigations of fat bodies and will be useful

  1. Transcriptome analysis of fat bodies from two brown planthopper (Nilaparvata lugens) populations with different virulence levels in rice.

    Science.gov (United States)

    Yu, Haixin; Ji, Rui; Ye, Wenfeng; Chen, Hongdan; Lai, Wenxiang; Fu, Qiang; Lou, Yonggen

    2014-01-01

    The brown planthopper (BPH), Nilaparvata lugens (Stål), one of the most serious rice insect pests in Asia, can quickly overcome rice resistance by evolving new virulent populations. The insect fat body plays essential roles in the life cycles of insects and in plant-insect interactions. However, whether differences in fat body transcriptomes exist between insect populations with different virulence levels and whether the transcriptomic differences are related to insect virulence remain largely unknown. In this study, we performed transcriptome-wide analyses on the fat bodies of two BPH populations with different virulence levels in rice. The populations were derived from rice variety TN1 (TN1 population) and Mudgo (M population). In total, 33,776 and 32,332 unigenes from the fat bodies of TN1 and M populations, respectively, were generated using Illumina technology. Gene ontology annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology classifications indicated that genes related to metabolism and immunity were significantly active in the fat bodies. In addition, a total of 339 unigenes showed homology to genes of yeast-like symbionts (YLSs) from 12 genera and endosymbiotic bacteria Wolbachia. A comparative analysis of the two transcriptomes generated 7,860 differentially expressed genes. GO annotations and enrichment analysis of KEGG pathways indicated these differentially expressed transcripts might be involved in metabolism and immunity. Finally, 105 differentially expressed genes from YLSs and Wolbachia were identified, genes which might be associated with the formation of different virulent populations. This study was the first to compare the fat-body transcriptomes of two BPH populations having different virulence traits and to find genes that may be related to this difference. Our findings provide a molecular resource for future investigations of fat bodies and will be useful in examining the interactions between the fat body and virulence

  2. Salmonella enterica: Survival, Colonization, and Virulence Differences among Serovars

    Science.gov (United States)

    Andino, A.; Hanning, I.

    2015-01-01

    Data indicate that prevalence of specific serovars of Salmonella enterica in human foodborne illness is not correlated with their prevalence in feed. Given that feed is a suboptimal environment for S. enterica, it appears that survival in poultry feed may be an independent factor unrelated to virulence of specific serovars of Salmonella. Additionally, S. enterica serovars appear to have different host specificity and the ability to cause disease in those hosts is also serovar dependent. These differences among the serovars may be related to gene presence or absence and expression levels of those genes. With a better understanding of serovar specificity, mitigation methods can be implemented to control Salmonella at preharvest and postharvest levels. PMID:25664339

  3. Salmonella enterica: Survival, Colonization, and Virulence Differences among Serovars

    Directory of Open Access Journals (Sweden)

    A. Andino

    2015-01-01

    Full Text Available Data indicate that prevalence of specific serovars of Salmonella enterica in human foodborne illness is not correlated with their prevalence in feed. Given that feed is a suboptimal environment for S. enterica, it appears that survival in poultry feed may be an independent factor unrelated to virulence of specific serovars of Salmonella. Additionally, S. enterica serovars appear to have different host specificity and the ability to cause disease in those hosts is also serovar dependent. These differences among the serovars may be related to gene presence or absence and expression levels of those genes. With a better understanding of serovar specificity, mitigation methods can be implemented to control Salmonella at preharvest and postharvest levels.

  4. The juvenile antisocial brain : brain imaging studies in clinically antisocial youth with nascent phychopathic traits

    NARCIS (Netherlands)

    Aghajani, M.

    2018-01-01

    The work presented in this thesis provides important new clues on the neurobiology of juvenile psychopathic traits in clinically antisocial juveniles. The data specifically shows that these traits are ostensibly underpinned by highly specific corticolimbic network dysfunctions, in which

  5. Virulence factors of the Mycobacterium tuberculosis complex

    Science.gov (United States)

    Forrellad, Marina A.; Klepp, Laura I.; Gioffré, Andrea; Sabio y García, Julia; Morbidoni, Hector R.; Santangelo, María de la Paz; Cataldi, Angel A.; Bigi, Fabiana

    2013-01-01

    The Mycobacterium tuberculosis complex (MTBC) consists of closely related species that cause tuberculosis in both humans and animals. This illness, still today, remains to be one of the leading causes of morbidity and mortality throughout the world. The mycobacteria enter the host by air, and, once in the lungs, are phagocytated by macrophages. This may lead to the rapid elimination of the bacillus or to the triggering of an active tuberculosis infection. A large number of different virulence factors have evolved in MTBC members as a response to the host immune reaction. The aim of this review is to describe the bacterial genes/proteins that are essential for the virulence of MTBC species, and that have been demonstrated in an in vivo model of infection. Knowledge of MTBC virulence factors is essential for the development of new vaccines and drugs to help manage the disease toward an increasingly more tuberculosis-free world. PMID:23076359

  6. Verified Subtyping with Traits and Mixins

    Directory of Open Access Journals (Sweden)

    Asankhaya Sharma

    2014-07-01

    Full Text Available Traits allow decomposing programs into smaller parts and mixins are a form of composition that resemble multiple inheritance. Unfortunately, in the presence of traits, programming languages like Scala give up on subtyping relation between objects. In this paper, we present a method to check subtyping between objects based on entailment in separation logic. We implement our method as a domain specific language in Scala and apply it on the Scala standard library. We have verified that 67% of mixins used in the Scala standard library do indeed conform to subtyping between the traits that are used to build them.

  7. Glucose starvation boosts Entamoeba histolytica virulence.

    Directory of Open Access Journals (Sweden)

    Ayala Tovy

    2011-08-01

    Full Text Available The unicellular parasite, Entamoeba histolytica, is exposed to numerous adverse conditions, such as nutrient deprivation, during its life cycle stages in the human host. In the present study, we examined whether the parasite virulence could be influenced by glucose starvation (GS. The migratory behaviour of the parasite and its capability to kill mammalian cells and to lyse erythrocytes is strongly enhanced following GS. In order to gain insights into the mechanism underlying the GS boosting effects on virulence, we analyzed differences in protein expression levels in control and glucose-starved trophozoites, by quantitative proteomic analysis. We observed that upstream regulatory element 3-binding protein (URE3-BP, a transcription factor that modulates E.histolytica virulence, and the lysine-rich protein 1 (KRiP1 which is induced during liver abscess development, are upregulated by GS. We also analyzed E. histolytica membrane fractions and noticed that the Gal/GalNAc lectin light subunit LgL1 is up-regulated by GS. Surprisingly, amoebapore A (Ap-A and cysteine proteinase A5 (CP-A5, two important E. histolytica virulence factors, were strongly down-regulated by GS. While the boosting effect of GS on E. histolytica virulence was conserved in strains silenced for Ap-A and CP-A5, it was lost in LgL1 and in KRiP1 down-regulated strains. These data emphasize the unexpected role of GS in the modulation of E.histolytica virulence and the involvement of KRiP1 and Lgl1 in this phenomenon.

  8. Bmh1p (14-3-3) mediates pathways associated with virulence in Candida albicans.

    Science.gov (United States)

    Kelly, Michelle N; Johnston, Douglas A; Peel, Bethany A; Morgan, Timothy W; Palmer, Glen E; Sturtevant, Joy E

    2009-05-01

    The ability of the pathogenic fungus Candida albicans to cause disease requires rapid adaptation to changes in the host environment and to an evolving host immune response. The identification of 'virulence factors' using in vitro characterization of mutant strains has traditionally relied on a common set of phenotypic and biochemical assays (most often performed at 30 degrees C) and the subsequent correlation with their corresponding virulence in mouse models of disease. Utilizing a panel of isogenic mutants for the multifunctional signal-modulating 14-3-3 protein (Bmh1p), we have found that specific mutations affect a variety of different pathways currently associated with virulence, including those involved with the formation of filaments, as well as interaction with host immune cells. Surprisingly, our studies revealed that deficiencies in many of these pathways do not always correlate with virulence in a mouse model of disseminated infection. Mutations within the binding pocket of Bmh1p that affect the ability of the protein to efficiently bind ligand had varying effects on the results of a number of in vitro and in vivo assays. The capability, in vitro, to filament in embedment conditions, and to filament and form chlamydospores under microaerophilic conditions on cornmeal agar, does not correlate with virulence. It is likely that only a subset of hyphal signalling pathways is actually required for the establishment of infection in the disseminated mouse model. Most importantly, our results suggest that the delayed onset of log-phase [corrected] growth in vitro at 37 degrees C, and not at 30 degrees C, results in an inability of these mutants to rapidly adjust to environmental changes in vivo and may be responsible for their increased clearance and reduced virulence. It is critical, therefore, that future in vitro studies of putative virulence factors in C. albicans include careful characterization at physiological temperatures.

  9. Genetic Virulence Profile of Enteroaggregative Escherichia coli Strains Isolated from Danish Children with Either Acute or Persistent Diarrhea

    OpenAIRE

    Betina Hebbelstrup Jensen; Anja Poulsen; Stig Hebbelstrup Rye Rasmussen; Carsten Struve; Jørgen H. Engberg; Alice Friis-Møller; Nadia Boisen; Rie Jønsson; Randi F. Petersen; Andreas M. Petersen; Andreas M. Petersen; Andreas M. Petersen; Karen A. Krogfelt

    2017-01-01

    Enteroaggregative Escherichia coli (EAEC) is frequently found in diarrheal stools worldwide. It has been associated with persistent diarrhea, weight loss, and failure to thrive in children living in developing countries. A number of important EAEC virulence genes are identified; however, their roles in acute and persistent diarrhea have not been previously investigated. The aim of this study was to identify specific EAEC virulence genes associated with duration and type of diarrhea in Danish ...

  10. GlobAl Distribution of GEnetic Traits (GADGET) web server: polygenic trait scores worldwide.

    Science.gov (United States)

    Chande, Aroon T; Wang, Lu; Rishishwar, Lavanya; Conley, Andrew B; Norris, Emily T; Valderrama-Aguirre, Augusto; Jordan, I King

    2018-05-18

    Human populations from around the world show striking phenotypic variation across a wide variety of traits. Genome-wide association studies (GWAS) are used to uncover genetic variants that influence the expression of heritable human traits; accordingly, population-specific distributions of GWAS-implicated variants may shed light on the genetic basis of human phenotypic diversity. With this in mind, we developed the GlobAl Distribution of GEnetic Traits web server (GADGET http://gadget.biosci.gatech.edu). The GADGET web server provides users with a dynamic visual platform for exploring the relationship between worldwide genetic diversity and the genetic architecture underlying numerous human phenotypes. GADGET integrates trait-implicated single nucleotide polymorphisms (SNPs) from GWAS, with population genetic data from the 1000 Genomes Project, to calculate genome-wide polygenic trait scores (PTS) for 818 phenotypes in 2504 individual genomes. Population-specific distributions of PTS are shown for 26 human populations across 5 continental population groups, with traits ordered based on the extent of variation observed among populations. Users of GADGET can also upload custom trait SNP sets to visualize global PTS distributions for their own traits of interest.

  11. Integrative genomic analysis identifies isoleucine and CodY as regulators of Listeria monocytogenes virulence.

    Directory of Open Access Journals (Sweden)

    Lior Lobel

    2012-09-01

    Full Text Available Intracellular bacterial pathogens are metabolically adapted to grow within mammalian cells. While these adaptations are fundamental to the ability to cause disease, we know little about the relationship between the pathogen's metabolism and virulence. Here we used an integrative Metabolic Analysis Tool that combines transcriptome data with genome-scale metabolic models to define the metabolic requirements of Listeria monocytogenes during infection. Twelve metabolic pathways were identified as differentially active during L. monocytogenes growth in macrophage cells. Intracellular replication requires de novo synthesis of histidine, arginine, purine, and branch chain amino acids (BCAAs, as well as catabolism of L-rhamnose and glycerol. The importance of each metabolic pathway during infection was confirmed by generation of gene knockout mutants in the respective pathways. Next, we investigated the association of these metabolic requirements in the regulation of L. monocytogenes virulence. Here we show that limiting BCAA concentrations, primarily isoleucine, results in robust induction of the master virulence activator gene, prfA, and the PrfA-regulated genes. This response was specific and required the nutrient responsive regulator CodY, which is known to bind isoleucine. Further analysis demonstrated that CodY is involved in prfA regulation, playing a role in prfA activation under limiting conditions of BCAAs. This study evidences an additional regulatory mechanism underlying L. monocytogenes virulence, placing CodY at the crossroads of metabolism and virulence.

  12. Antimicrobial peptide GH12 suppresses cariogenic virulence factors of Streptococcus mutans

    Science.gov (United States)

    Wang, Yufei; Wang, Xiuqing; Jiang, Wentao; Wang, Kun; Luo, Junyuan; Li, Wei; Zhou, Xuedong; Zhang, Linglin

    2018-01-01

    ABSTRACT Cariogenic virulence factors of Streptococcus mutans include acidogenicity, aciduricity, and extracellular polysaccharides (EPS) synthesis. The de novo designed antimicrobial peptide GH12 has shown bactericidal effects on S. mutans, but its interaction with virulence and regulatory systems of S. mutans remains to be elucidated. The objectives were to investigate the effects of GH12 on virulence factors of S. mutans, and further explore the function mechanisms at enzymatic and transcriptional levels. To avoid decrease in bacterial viability, we limited GH12 to subinhibitory levels. We evaluated effects of GH12 on acidogenicity of S. mutans by pH drop, lactic acid measurement and lactate dehydrogenase (LDH) assay, on aciduricity through survival rate at pH 5.0 and F1F0-ATPase assay, and on EPS synthesis using quantitative measurement, morphology observation, vertical distribution analyses and biomass calculation. Afterwards, we conducted quantitative real-time PCR to acquire the expression profile of related genes. GH12 at 1/2 MIC (4 mg/L) inhibited acid production, survival rate, EPS synthesis, and biofilm formation. The enzymatic activity of LDH and F1F0-ATPase was inhibited, and ldh, gtfBCD, vicR, liaR, and comDE genes were significantly downregulated. In conclusion, GH12 inhibited virulence factors of S. mutans, through reducing the activity of related enzymes, downregulating virulence genes, and inactivating specific regulatory systems. PMID:29503706

  13. Microarray Evaluation of Antimicrobial Resistance and Virulence of Escherichia coli Isolates from Portuguese Poultry

    Directory of Open Access Journals (Sweden)

    Nuno Mendonça

    2016-01-01

    Full Text Available The presence of antimicrobial resistance and virulence factors of 174 Escherichia coli strains isolated from healthy Portuguese Gallus gallus was evaluated. Resistance profiles were determined against 33 antimicrobials by microbroth dilution. Resistance was prevalent for tetracycline (70% and ampicillin (63%. Extended-spectrum beta-lactamase (ESBL phenotype was observed in 18% of the isolates. Multidrug resistance was found in 56% of isolates. A subset of 74 isolates were screened by DNA microarrays for the carriage of 88 antibiotic resistance genes and 62 virulence genes. Overall, 37 different resistance genes were detected. The most common were tet(A (72%, blaTEM (68%, and sul1 (47%, while 21% isolates harbored an ESBL gene (blaCTX-M group 1, group 2, or group 9. Of these, 96% carried the increased serum survival (iss virulence gene, while 89% presented the enterobactin siderophore receptor protein (iroN, 70% the temperature-sensitive hemagglutinin (tsh, and 68% the long polar fimbriae (lpfA virulence genes associated with extraintestinal pathogenic E. coli. In conclusion, prevalence of antibiotic resistant E. coli from the microbiota of Portuguese chickens was high, including to extended spectrum cephalosporins. The majority of isolates seems to have the potential to trigger extraintestinal human infection due to the presence of some virulence genes. However, the absence of genes specific for enteropathogenic E. coli reduces the risk for human intestinal infection.

  14. Taxonomy, virulence and epidemiology of black-pigmented Bacteroides species in relation to oral infections.

    Science.gov (United States)

    van Steenbergen, T J; van Winkelhoff, A J; van der Velden, U; de Graaff, J

    1989-01-01

    Black-pigmented Bacteroides species are recognized as suspected pathogens of oral infections. Developments in the taxonomy of this group include description of a new asaccharolytic species, Bacteroides salivosus, and proposal for the reclassification of the asaccharolytic species into a separate genus, Porphyromonas. Studies on the pathogenicity and virulence of black-pigmented Bacteroides species have identified Bacteroides gingivalis as the most virulent species. B. gingivalis and Bacteroides intermedius have been associated with periodontal diseases; Bacteroides endodontalis is isolated specifically from infections in the oral cavity, and other black-pigmented Bacteroides species are recovered from oral mucous sites. DNA restriction endonuclease analysis was adapted for typing of B. gingivalis and B. intermedius.

  15. Escherichia coli Isolates Causing Asymptomatic Bacteriuria in Catheterized and Noncatheterized Individuals Possess Similar Virulence Properties

    DEFF Research Database (Denmark)

    Watts, Rebecca E; Hancock, Viktoria; Ong, Cheryl-lynn Y

    2010-01-01

    Urinary tract infections (UTIs) are among the most common infectious diseases of humans, with Escherichia coli being responsible for >80% of all cases. Asymptomatic bacteriuria (ABU) occurs when bacteria colonize the urinary tract without causing clinical symptoms and can affect both catheterized...... patients (catheter-associated ABU [CA-ABU]) and noncatheterized patients. Here, we compared the virulence properties of a collection of ABU and CA-ABU nosocomial E. coli isolates in terms of antibiotic resistance, phylogenetic grouping, specific UTI-associated virulence genes, hemagglutination...

  16. trans-Acting Virulence Functions of the Octopine Ti Plasmid from Agrobacterium tumefaciens

    NARCIS (Netherlands)

    Hille, Jacques; Kan, Jan van; Schilperoort, Rob

    1984-01-01

    All Ti plasmid-encoded virulence functions that were studied act in trans. An octopine Ti plasmid-specific vir operon, called vir-O, located on an EcoRI restriction fragment has been characterized. Sequences with promoter activity in Escherichia coli were identified for a second vir operon, called

  17. Non-lethal infection parameters in mice separate sheep Type II Toxoplasma gondii isolates by virulence

    DEFF Research Database (Denmark)

    Jungersen, Gregers; Jensen, L; Rask, M.R.

    2002-01-01

    . six sheep abortions, two pigs. one cat and one fox were examined for their virulence to young mice by less dramatic parameters. Clinical disease of inoculated mice, directly evidenced by reduced weight gain, was correlated to increase in serum level of haptoglobin and level of specific antibodies...

  18. Presence of virulent Newcastle disease virus in vaccinated chickens in farms in Pakistan

    Science.gov (United States)

    The sites where virulent Newcastle disease virus persists in endemic countries are unknown. Evidence presented here shows that the same strain that caused a previous outbreak was present in both apparently healthy and sick vaccinated birds from multiple farms that had high average specific antibody...

  19. The Toxin and Virulence Database: A Resource for Signature Development and Analysis of Virulence

    National Research Council Canada - National Science Library

    Wolinsky, Murray A

    2004-01-01

    In this joint effort with the University of Alabama at Birmingham, Walter Reed, MITRE and USAMRIID, we are developing a comprehensive database for microbial toxins and virulence factors (www.tvfac.lanl.gov...

  20. Variation in genotype and higher virulence of a strain of Sporothrix schenckii causing disseminated cutaneous sporotrichosis.

    Science.gov (United States)

    Zhang, Zhenying; Liu, Xiaoming; Lv, Xuelian; Lin, Jingrong

    2011-12-01

    Sporotrichosis is usually a localized, lymphocutaneous disease, but its disseminated type was rarely reported. The main objective of this study was to identify specific DNA sequence variation and virulence of a strain of Sporothrix schenckii isolated from the lesion of disseminated cutaneous sporotrichosis. We confirmed this strain to be S. schenckii by(®) tubulin and chitin synthase gene sequence analysis in addition to the routine mycological and partial ITS and NTS sequencing. We found a 10-bp deletion in the ribosomal NTS region of this strain, in reference to the sequence of control strains isolated from fixed cutaneous sporotrichosis. After inoculated into immunosuppressed mice, this strain caused more extensive system involvement and showed stronger virulence than the control strain isolated from a fixed cutaneous sporotrichosis. Our study thus suggests that different clinical manifestation of sporotrichosis may be associated with variation in genotype and virulence of the strain, independent of effects due to the immune status of the host.

  1. Are secondary metabolites dispensable for virulence?

    Science.gov (United States)

    The production of toxins by conidial fungal pathogens and their association with virulence has been assumed to occur in vivo and is widely accepted as dogma, but this association has yet to be definitively proven by either genetic or chemical means. Several studies from our labs have used targeted g...

  2. Mechanisms of disease: Helicobacter pylori virulence factors.

    Science.gov (United States)

    Yamaoka, Yoshio

    2010-11-01

    Helicobacter pylori plays an essential role in the development of various gastroduodenal diseases; however, only a small proportion of people infected with H. pylori develop these diseases. Some populations that have a high prevalence of H. pylori infection also have a high incidence of gastric cancer (for example, in East Asia), whereas others do not (for example, in Africa and South Asia). Even within East Asia, the incidence of gastric cancer varies (decreasing in the south). H. pylori is a highly heterogeneous bacterium and its virulence varies geographically. Geographic differences in the incidence of gastric cancer can be explained, at least in part, by the presence of different types of H. pylori virulence factor, especially CagA, VacA and OipA. However, it is still unclear why the pathogenicity of H. pylori increased as it migrated from Africa to East Asia during the course of evolution. H. pylori infection is also thought to be involved in the development of duodenal ulcer, which is at the opposite end of the disease spectrum to gastric cancer. This discrepancy can be explained in part by the presence of H. pylori virulence factor DupA. Despite advances in our understanding of the development of H. pylori-related diseases, further work is required to clarify the roles of H. pylori virulence factors.

  3. Efflux inhibitor suppresses Streptococcus mutans virulence properties.

    Science.gov (United States)

    Zeng, Huihui; Liu, Jia; Ling, Junqi

    2017-04-01

    It is well established that efflux pumps play important roles in bacterial pathogenicity and efflux inhibitors (EIs) have been proved to be effective in suppressing bacterial virulence properties. However, little is known regarding the EI of Streptococcus mutans, a well-known caries-inducing bacterium. In this study, we identified the EI of S. mutans through ethidium bromide efflux assay and investigated how EI affected S. mutans virulence regarding the cariogenicity and stress response. Results indicated that reserpine, the identified EI, suppressed acid tolerance, mutacin production and transformation efficiency of S. mutans, and modified biofilm architecture and extracellular polysaccharide distribution. Suppressed glycosyltransferase activity was also noted after reserpine exposure. The data from quantitative real-time-PCR demonstrated that reserpine significantly altered the expression profile of quorum-sensing and virulence-associated genes. These findings suggest that reserpine represents a promising adjunct anticariogenic agent in that it suppresses virulence properties of S. mutans. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Microbial virulence and interactions with metals

    DEFF Research Database (Denmark)

    German, N.; Lüthje, Freja Lea; Hao, X.

    2016-01-01

    Transition metals, such as iron, copper, zinc, and manganese play an important role in many bacterial biological processes that add to an overall evolutional fitness of bacteria. They are often involved in regulation of bacterial virulence as a mechanism of host invasion. However, the same transi...

  5. NEW VIRULENCE FACTORS OF STREPTOCOCCUS PNEUMONIAE

    NARCIS (Netherlands)

    Hermans, Peter Wilhelmus Maria; Bootsma, Jeanette Hester; Burghout, Pieter Jan; Kuipers, Oscar; Bijlsma, Johanna Jacoba Elisabeth; Kloosterman, Tomas Gerrit; Andersen, Christian O.

    2011-01-01

    The present invention provides proteins/genes, which are essential for survival, and consequently, for virulence of Streptococcus pneumoniae in vivo, and thus are ideal vaccine candidates for a vaccine preparation against pneumococcal infection. Further, also antibodies against said protein(s) are

  6. Three Herpes Simplex Virus Type 1 Latency-Associated Transcript Mutants with Distinct and Asymmetric Effects on Virulence in Mice Compared with Rabbits

    Science.gov (United States)

    Perng, Guey-Chuen; Esmaili, Daniel; Slanina, Susan M.; Yukht, Ada; Ghiasi, Homayon; Osorio, Nelson; Mott, Kevin R.; Maguen, Barak; Jin, Ling; Nesburn, Anthony B.; Wechsler, Steven L.

    2001-01-01

    Herpes simplex virus type 1 latency-associated transcript (LAT)-null mutants have decreased reactivation but normal virulence in rabbits and mice. We report here on dLAT1.5, a mutant with LAT nucleotides 76 to 1667 deleted. Following ocular infection of rabbits, dLAT1.5 reactivated at a lower rate than its wild-type parent McKrae (6.1 versus 11.8%; P = 0.0025 [chi-square test]). Reactivation was restored in the marker-rescued virus dLAT1.5R (12.6%; P = 0.53 versus wild type), confirming the importance of the deleted region in spontaneous reactivation. Compared with wild-type or marker-rescued virus, dLAT1.5 had similar or slightly reduced virulence in rabbits (based on survival following ocular infection). In contrast, in mice, dLAT1.5 had increased virulence (P Wechsler, J. Virol. 73:920–929, 1999), had decreased virulence in mice (P = 0.03). In addition, we also found that dLAT371, a LAT mutant that we previously reported to have wild-type virulence in rabbits (G. C. Perng, S. M. Slanina, H. Ghiasi, A. B. Nesburn, and S. L. Wechsler, J. Virol. 70:2014–2018, 1996), had decreased virulence in mice (P < 0.05). Thus, these three mutants, each of which encodes a different LAT RNA, have different virulence phenotypes. dLAT1.5 had wild-type virulence in rabbits but increased virulence in mice. In contrast, LAT2.9A had increased virulence in rabbits but decreased virulence in mice, and dLAT371 had wild-type virulence in rabbits but decreased virulence in mice. Taken together, these results suggest that (i) the 5′ end of LAT and/or a gene that overlaps part of this region is involved in viral virulence, (ii) this virulence appears to have species-specific effects, and (iii) regulation of this virulence may be complex. PMID:11533165

  7. Identification of O-mannosylated virulence factors in Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Alfonso Fernández-Álvarez

    Full Text Available The O-mannosyltransferase Pmt4 has emerged as crucial for fungal virulence in the animal pathogens Candida albicans or Cryptococcus neoformans as well as in the phytopathogenic fungus Ustilago maydis. Pmt4 O-mannosylates specific target proteins at the Endoplasmic Reticulum. Therefore a deficient O-mannosylation of these target proteins must be responsible for the loss of pathogenicity in pmt4 mutants. Taking advantage of the characteristics described for Pmt4 substrates in Saccharomyces cerevisiae, we performed a proteome-wide bioinformatic approach to identify putative Pmt4 targets in the corn smut fungus U. maydis and validated Pmt4-mediated glycosylation of candidate proteins by electrophoretic mobility shift assays. We found that the signalling mucin Msb2, which regulates appressorium differentiation upstream of the pathogenicity-related MAP kinase cascade, is O-mannosylated by Pmt4. The epistatic relationship of pmt4 and msb2 showed that both are likely to act in the same pathway. Furthermore, constitutive activation of the MAP kinase cascade restored appressorium development in pmt4 mutants, suggesting that during the initial phase of infection the failure to O-mannosylate Msb2 is responsible for the virulence defect of pmt4 mutants. On the other hand we demonstrate that during later stages of pathogenic development Pmt4 affects virulence independently of Msb2, probably by modifying secreted effector proteins. Pit1, a protein required for fungal spreading inside the infected leaf, was also identified as a Pmt4 target. Thus, O-mannosylation of different target proteins affects various stages of pathogenic development in U. maydis.

  8. Gender and personality traits' (BFI-10) effect on opinion leadership

    DEFF Research Database (Denmark)

    Olexova, Cecilia; Sudzina, Frantisek

    2017-01-01

    Opinion leadership used to be perceived as a highly domain-specific trait but it was found to be multi-faceted, i.e. individuals are influential independent of a specific subject area. Another term is generalized opinion leadership. Impact of Big Five Inventory personality traits on domain...

  9. Frequency of virulence factors in Helicobacter pylori-infected patients with gastritis.

    Science.gov (United States)

    Salimzadeh, Loghman; Bagheri, Nader; Zamanzad, Behnam; Azadegan-Dehkordi, Fatemeh; Rahimian, Ghorbanali; Hashemzadeh-Chaleshtori, Morteza; Rafieian-Kopaei, Mahmoud; Sanei, Mohammad Hossein; Shirzad, Hedayatollah

    2015-03-01

    The outcome of Helicobacter pylori infection has been related to specific virulence-associated bacterial genotypes. The vacuolating cytotoxin (vacA), cagA gene, oipA and babA2 gene are important virulence factor involving gastric diseases. The objective of this study was to assess the relationship between virulence factors of H. pylori and histopathological findings. Gastroduodenoscopy was performed in 436 dyspeptic patients. Antrum biopsy was obtained for detection of H. pylori, virulence factors and for histopathological assessment. The polymerase chain reaction was used to detect virulence factors of H. pylori using specific primers. vacA genotypes in patients infected with H. pylori were associated with cagA, iceA1 and iceA2. In the patients with H. pylori infection there was a significant relationship between cagA positivity and neutrophil activity (P = 0.004) and chronic inflammation (P = 0.013) and with H. pylori density (P = 0.034). Neutrophil infiltration was found to be more severe in the s1 group than in the s2 group (P = 0.042). Also was a significant relationship between oipA positivity and neutrophil activity (P = 0.004) and with H. pylori density (P = 0.018). No significant relationships were observed between other vacA genotypes and histopathological parameters. H. pylori strains showing cagA, vacA s1 and oipA positivity are associated with more severe gastritis in some histological features but virulence factors of H. pylori do not appear to determine the overall pattern of gastritis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Identification of organic acids in Cichorium intybus inhibiting virulence-related properties of oral pathogenic bacteria.

    Science.gov (United States)

    Papetti, Adele; Mascherpa, Dora; Carazzone, Chiara; Stauder, Monica; Spratt, David A; Wilson, Michael; Pratten, Jonathan; Ciric, Lena; Lingström, Peter; Zaura, Egija; Weiss, Ervin; Ofek, Itzak; Signoretto, Caterina; Pruzzo, Carla; Gazzani, Gabriella

    2013-06-01

    The low molecular mass (LMM) extract of Cichorium intybus var. silvestre (red chicory) has been shown to inhibit virulence-linked properties of oral pathogens including Streptococcus mutans, Actinomyces naeslundii and Prevotella intermedia. In the present study HPLC-DAD-ESI/MS(2) was used to investigate the compounds contained in this extract for their anti-virulence activity. The extract contained a number of components, including oxalic, succinic, shikimic and quinic acids, which interfere with the growth and virulence traits (i.e., biofilm formation, adherence to epithelial cells and hydroxyapatite) of oral pathogens involved in gingivitis and tooth decay. Succinic and quinic acid seem to be the most potent, mainly by interfering with the ability of oral pathogens to form biofilms (either through inhibition of their development or promotion of their disruption). Our findings suggest that one or more of these compounds may modulate plaque formation in vivo, which is a prerequisite for the development of both caries and gingivitis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Prevalence of diarrheagenic Escherichia coli virulence genes in the feces of slaughtered cattle, chickens, and pigs in Burkina Faso

    Science.gov (United States)

    Kagambèga, Assèta; Martikainen, Outi; Siitonen, Anja; Traoré, Alfred S; Barro, Nicolas; Haukka, Kaisa

    2012-01-01

    We investigated the prevalence of the virulence genes specific for five major pathogroups of diarrheagenic Escherichia coli (DEC) in primary cultures from feces of animals slaughtered for human consumption in Burkina Faso. For the study, 704 feces samples were collected from cattle (n = 304), chickens (n = 350), and pigs (n = 50) during carcass processing. The presence of the virulence-associated genes in the mixed bacterial cultures was assessed using 16-plex polymerase chain reaction (PCR). Virulence genes indicating presence of DEC were detected in 48% of the cattle, 48% of the chicken, and 68% of the pig feces samples. Virulence genes specific for different DECs were detected in the following percentages of the cattle, chicken, and pig feces samples: Shiga toxin-producing E. coli (STEC) in 37%, 6%, and 30%; enteropathogenic E. coli (EPEC) in 8%, 37%, and 32%; enterotoxigenic E. coli (ETEC) in 4%, 5%, and 18%; and enteroaggregative E. coli (EAEC) in 7%, 6%, and 32%. Enteroinvasive E. coli (EIEC) virulence genes were detected in 1% of chicken feces samples only. The study was the first of its kind in Burkina Faso and revealed the common occurrence of the diarrheal virulence genes in feces of food animals. This indicates that food animals are reservoirs of DEC that may contaminate meat because of the defective slaughter and storage conditions and pose a health risk to the consumers in Burkina Faso. PMID:23170227

  12. Evaluation of a FRET-peptide substrate to predict virulence in Pseudomonas aeruginosa.

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    Wendy E Kaman

    Full Text Available Pseudomonas aeruginosa produces a number of proteases that are associated with virulence and disease progression. A substrate able to detect P. aeruginosa-specific proteolytic activity could help to rapidly alert clinicians to the virulence potential of individual P. aeruginosa strains. For this purpose we designed a set of P. aeruginosa-specific fluorogenic substrates, comprising fluorescence resonance energy transfer (FRET-labeled peptides, and evaluated their applicability to P. aeruginosa virulence in a range of clinical isolates. A FRET-peptide comprising three glycines (3xGly was found to be specific for the detection of P. aeruginosa proteases. Further screening of 97 P. aeruginosa clinical isolates showed a wide variation in 3xGly cleavage activity. The absence of 3xGly degradation by a lasI knock out strain indicated that 3xGly cleavage by P. aeruginosa could be quorum sensing (QS-related, a hypothesis strengthened by the observation of a strong correlation between 3xGly cleavage, LasA staphylolytic activity and pyocyanin production. Additionally, isolates able to cleave 3xGly were more susceptible to the QS inhibiting antibiotic azithromycin (AZM. In conclusion, we designed and evaluated a 3xGly substrate possibly useful as a simple tool to predict virulence and AZM susceptibility.

  13. Genome-wide identification of Pseudomonas aeruginosa virulence-related genes using a Caenorhabditis elegans infection model.

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    Rhonda L Feinbaum

    Full Text Available Pseudomonas aeruginosa strain PA14 is an opportunistic human pathogen capable of infecting a wide range of organisms including the nematode Caenorhabditis elegans. We used a non-redundant transposon mutant library consisting of 5,850 clones corresponding to 75% of the total and approximately 80% of the non-essential PA14 ORFs to carry out a genome-wide screen for attenuation of PA14 virulence in C. elegans. We defined a functionally diverse 180 mutant set (representing 170 unique genes necessary for normal levels of virulence that included both known and novel virulence factors. Seven previously uncharacterized virulence genes (ABC transporters PchH and PchI, aminopeptidase PepP, ATPase/molecular chaperone ClpA, cold shock domain protein PA0456, putative enoyl-CoA hydratase/isomerase PA0745, and putative transcriptional regulator PA14_27700 were characterized with respect to pigment production and motility and all but one of these mutants exhibited pleiotropic defects in addition to their avirulent phenotype. We examined the collection of genes required for normal levels of PA14 virulence with respect to occurrence in P. aeruginosa strain-specific genomic regions, location on putative and known genomic islands, and phylogenetic distribution across prokaryotes. Genes predominantly contributing to virulence in C. elegans showed neither a bias for strain-specific regions of the P. aeruginosa genome nor for putatively horizontally transferred genomic islands. Instead, within the collection of virulence-related PA14 genes, there was an overrepresentation of genes with a broad phylogenetic distribution that also occur with high frequency in many prokaryotic clades, suggesting that in aggregate the genes required for PA14 virulence in C. elegans are biased towards evolutionarily conserved genes.

  14. Genome-wide identification of Pseudomonas aeruginosa virulence-related genes using a Caenorhabditis elegans infection model.

    Science.gov (United States)

    Feinbaum, Rhonda L; Urbach, Jonathan M; Liberati, Nicole T; Djonovic, Slavica; Adonizio, Allison; Carvunis, Anne-Ruxandra; Ausubel, Frederick M

    2012-01-01

    Pseudomonas aeruginosa strain PA14 is an opportunistic human pathogen capable of infecting a wide range of organisms including the nematode Caenorhabditis elegans. We used a non-redundant transposon mutant library consisting of 5,850 clones corresponding to 75% of the total and approximately 80% of the non-essential PA14 ORFs to carry out a genome-wide screen for attenuation of PA14 virulence in C. elegans. We defined a functionally diverse 180 mutant set (representing 170 unique genes) necessary for normal levels of virulence that included both known and novel virulence factors. Seven previously uncharacterized virulence genes (ABC transporters PchH and PchI, aminopeptidase PepP, ATPase/molecular chaperone ClpA, cold shock domain protein PA0456, putative enoyl-CoA hydratase/isomerase PA0745, and putative transcriptional regulator PA14_27700) were characterized with respect to pigment production and motility and all but one of these mutants exhibited pleiotropic defects in addition to their avirulent phenotype. We examined the collection of genes required for normal levels of PA14 virulence with respect to occurrence in P. aeruginosa strain-specific genomic regions, location on putative and known genomic islands, and phylogenetic distribution across prokaryotes. Genes predominantly contributing to virulence in C. elegans showed neither a bias for strain-specific regions of the P. aeruginosa genome nor for putatively horizontally transferred genomic islands. Instead, within the collection of virulence-related PA14 genes, there was an overrepresentation of genes with a broad phylogenetic distribution that also occur with high frequency in many prokaryotic clades, suggesting that in aggregate the genes required for PA14 virulence in C. elegans are biased towards evolutionarily conserved genes.

  15. Coliform bacteria isolated from recreational lakes carry class 1 and class 2 integrons and virulence-associated genes.

    Science.gov (United States)

    Koczura, R; Krysiak, N; Taraszewska, A; Mokracka, J

    2015-08-01

    To characterize the integron-harbouring Gram-negative bacteria in recreational lakes, with focus on the genetic content of integrons, antimicrobial resistance profiles and virulence-associated genes. The presence and structure of integrons in coliform bacteria isolated from the water of four recreational lakes located in Poznań, Poland, was determined by PCR method. Antimicrobial resistance testing was done by disc diffusion method. Virulence-associated genes in integron-bearing Escherichia coli isolates were detected by PCR. A total of 155 integron-bearing strains of coliform bacteria were cultured. Sequence analysis showed the presence of dfrA7, aadA1, dfrA1-aadA1, dfrA17-aadA5 and dfrA12-orfF-aadA2 gene cassette arrays in class 1 integrons and dfrA1-sat2-aadA1 in class 2 integrons. Higher frequency of integron-positive bacteria and higher antimicrobial resistance ranges were noted in colder months (January and November) compared with spring and summer months. The integron-harbouring E. coli carried up to nine virulence-associated genes, with the highest frequency of kpsMT (84.6%) and traT (783%), coding for group 2 capsule and determining human serum resistance respectively. Integron-bearing multidrug resistant coliform bacteria carrying virulence genes are present in waters of recreational lakes. This study presents antimicrobial resistance and virulence-associated genes in integron-bearing coliform bacteria present in the waters of recreational lakes, which showed that multidrug resistant bacteria with virulence traits might pose a threat to public health. Moreover, the presence of genes typical for enterotoxigenic and Shiga toxin-producing E. coli is a concern. © 2015 The Society for Applied Microbiology.

  16. Subinhibitory quinupristin/dalfopristin attenuates virulence of Staphylococcus aureus.

    Science.gov (United States)

    Koszczol, Carmen; Bernardo, Katussevani; Krönke, Martin; Krut, Oleg

    2006-09-01

    The semi-synthetic streptogramin quinupristin/dalfopristin antibiotic exerts potent bactericidal activity against Staphylococcus aureus. We investigated whether, like other bactericidal antibiotics used at subinhibitory concentrations, quinupristin/dalfopristin enhances release of toxins by Gram-positive cocci. The activity of quinupristin/dalfopristin on exotoxin release by S. aureus was investigated by 2D SDS-PAGE combined with MALDI-TOF/MS analysis and by western blotting. We show that quinupristin/dalfopristin at subinhibitory concentrations reduces the release of S. aureus factors that induce tumour necrosis factor secretion in macrophages. Furthermore, quinupristin/dalfopristin but not linezolid attenuated S. aureus-mediated killing of infected host cells. When added to S. aureus cultures at different stages of bacterial growth, quinupristin/dalfopristin reduced in a dose-dependent manner the release of specific virulence factors (e.g. autolysin, protein A, alpha- and beta-haemolysins, lipases). In contrast, other presumably non-toxic exoproteins remained unchanged. The results of the present study suggest that subinhibitory quinupristin/dalfopristin inhibits virulence factor release by S. aureus, which might be especially helpful for the treatment of S. aureus infections, where both bactericidal as well as anti-toxin activity may be advantageous.

  17. Stress tolerant virulent strains of Cronobacter sakazakii from food

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    Md Fakruddin

    2014-01-01

    Full Text Available BACKGROUND: Cronobacter sakazakii is considered as an emerging foodborne pathogen. The aim of this study was to isolate and characterize virulent strains of Cronobacter sakazakii from food samples of Bangladesh. RESULT: Six (6 Cronobacter sakazakii was isolated and identified from 54 food samples on the basis of biochemical characteristics, sugar fermentation, SDS-PAGE of whole cell protein, plasmid profile and PCR of Cronobacter spp. specific genes (esak, gluA, zpx, ompA, ERIC, BOX-AIR and sequencing. These strains were found to have moderately high antibiotic resistance against common antibiotics and some are ESBL producer. Most of the C. sakazakii isolates were capable of producing biofilm (strong biofilm producer, extracellular protease and siderophores, curli expression, haemolysin, haemagglutinin, mannose resistant haemagglutinin, had high cell surface hydrophobicity, significant resistance to human serum, can tolerate high concentration of salt, bile and DNase production. Most of them produced enterotoxins of different molecular weight. The isolates pose significant serological cross-reactivity with other gram negative pathogens such as serotypes of Salmonella spp., Shigella boydii, Shigella sonnei, Shigella flexneri and Vibrio cholerae. They had significant tolerance to high temperature, low pH, dryness and osmotic stress. CONCLUSION: Special attention should be given in ensuring hygiene in production and post-processing to prevent contamination of food with such stress-tolerant virulent Cronobacter sakazakii.

  18. Identification of Pathways Critical to Quorum Sensing and Virulence Induction

    Energy Technology Data Exchange (ETDEWEB)

    Ognibene, Ted J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Young, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Holtz-Morris, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Daley, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2009-02-27

    Quorum sensing is a mode of intercellular communication between bacteria that allows them to collectively regulate behavior such as virulence, sporulation, motility and biofilm formation. It is mediated by bacterially synthesized, diffusible, signaling molecules (autoinducers) that increase in concentration as a bacterial population expands until a critical threshold concentration is reached. However, in most bacterial species that produce autoinducer molecules, the physiologic concentration of these molecules is unknown. Moreover, many bacterial species, including Y. pestis, produce an array of quorum sensing molecules and the physiologic concentration of each individual type of autoinducer molecule is not known. There is a need to accurately and precisely quantitate these molecules, as it may be that different types of autoinducer molecules have different effects on virulence in the bacterium. We focused our efforts on the construction of a platform to identify and quantitate autoinducer molecules using FTICR, 14C isotope labeling and accelerator mass spectrometry (AMS). Specifically, we focused on autoinducer-1 type molecules, acylhomoserine lactone (HSL), derived from S-adenosylmethionine (SAM).

  19. Developing Leadership Traits.

    Science.gov (United States)

    Hall, Susan King

    1980-01-01

    Defines six leadership traits that are necessary to and fostered by editing a college newspaper: delegating authority, developing subordinates, motivating others, being approachable, commanding respect, and bringing out optimum performances in others. (TJ)

  20. Influencing agent group behavior by adjusting cultural trait values.

    Science.gov (United States)

    Tuli, Gaurav; Hexmoor, Henry

    2010-10-01

    Social reasoning and norms among individuals that share cultural traits are largely fashioned by those traits. We have explored predominant sociological and cultural traits. We offer a methodology for parametrically adjusting relevant traits. This exploratory study heralds a capability to deliberately tune cultural group traits in order to produce a desired group behavior. To validate our methodology, we implemented a prototypical-agent-based simulated test bed for demonstrating an exemplar from intelligence, surveillance, and reconnaissance scenario. A group of simulated agents traverses a hostile territory while a user adjusts their cultural group trait settings. Group and individual utilities are dynamically observed against parametric values for the selected traits. Uncertainty avoidance index and individualism are the cultural traits we examined in depth. Upon the user's training of the correspondence between cultural values and system utilities, users deliberately produce the desired system utilities by issuing changes to trait. Specific cultural traits are without meaning outside of their context. Efficacy and timely application of traits in a given context do yield desirable results. This paper heralds a path for the control of large systems via parametric cultural adjustments.

  1. Novel cyclic di-GMP effectors of the YajQ protein family control bacterial virulence.

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    Shi-qi An

    2014-10-01

    Full Text Available Bis-(3',5' cyclic di-guanylate (cyclic di-GMP is a key bacterial second messenger that is implicated in the regulation of many critical processes that include motility, biofilm formation and virulence. Cyclic di-GMP influences diverse functions through interaction with a range of effectors. Our knowledge of these effectors and their different regulatory actions is far from complete, however. Here we have used an affinity pull-down assay using cyclic di-GMP-coupled magnetic beads to identify cyclic di-GMP binding proteins in the plant pathogen Xanthomonas campestris pv. campestris (Xcc. This analysis identified XC_3703, a protein of the YajQ family, as a potential cyclic di-GMP receptor. Isothermal titration calorimetry showed that the purified XC_3703 protein bound cyclic di-GMP with a high affinity (K(d∼2 µM. Mutation of XC_3703 led to reduced virulence of Xcc to plants and alteration in biofilm formation. Yeast two-hybrid and far-western analyses showed that XC_3703 was able to interact with XC_2801, a transcription factor of the LysR family. Mutation of XC_2801 and XC_3703 had partially overlapping effects on the transcriptome of Xcc, and both affected virulence. Electromobility shift assays showed that XC_3703 positively affected the binding of XC_2801 to the promoters of target virulence genes, an effect that was reversed by cyclic di-GMP. Genetic and functional analysis of YajQ family members from the human pathogens Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed that they also specifically bound cyclic di-GMP and contributed to virulence in model systems. The findings thus identify a new class of cyclic di-GMP effector that regulates bacterial virulence.

  2. Functional dissection of Streptococcus pyogenes M5 protein: the hypervariable region is essential for virulence.

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    Johan Waldemarsson

    Full Text Available The surface-localized M protein of Streptococcus pyogenes is a major virulence factor that inhibits phagocytosis, as determined ex vivo. Because little is known about the role of M protein in vivo we analyzed the contribution of different M protein regions to virulence, using the fibrinogen (Fg-binding M5 protein and a mouse model of acute invasive infection. This model was suitable, because M5 is required for mouse virulence and binds mouse and human Fg equally well, as shown here. Mixed infection experiments with wild type bacteria demonstrated that mutants lacking the N-terminal hypervariable region (HVR or the Fg-binding B-repeat region were strongly attenuated, while a mutant lacking the conserved C-repeats was only slightly attenuated. Because the HVR of M5 is not required for phagocytosis resistance, our data imply that this HVR plays a major but unknown role during acute infection. The B-repeat region is required for phagocytosis resistance and specifically binds Fg, suggesting that it promotes virulence by binding Fg. However, B-repeat mutants were attenuated even in Fg-deficient mice, implying that the B-repeats may have a second function, in addition to Fg-binding. These data demonstrate that two distinct M5 regions, including the HVR, are essential to virulence during the early stages of an infection. In particular, our data provide the first in vivo evidence that the HVR of an M protein plays a major role in virulence, focusing interest on the molecular role of this region.

  3. Ecological fitness and virulence features of Vibrio parahaemolyticus in estuarine environments.

    Science.gov (United States)

    Lovell, Charles R

    2017-03-01

    Vibrio parahaemolyticus is a commonly encountered and highly successful organism in marine ecosystems. It is a fast-growing, extremely versatile copiotroph that is active over a very broad range of conditions. It frequently occurs suspended in the water column (often attached to particles or zooplankton), and is a proficient colonist of submerged surfaces. This organism is an important pathogen of animals ranging from microcrustaceans to humans and is a causative agent of seafood-associated food poisoning. This review examines specific ecological adaptations of V. parahaemolyticus, including its broad tolerances to temperature and salinity, its utilization of a wide variety of organic carbon and energy sources, and its pervasive colonization of suspended and stationary materials that contribute to its success and ubiquity in temperate and tropical estuarine ecosystems. Several virulence-related features are examined, in particular the thermostable direct hemolysin (TDH), the TDH-related hemolysin (TRH), and the type 3 secretion system, and the possible importance of these features in V. parahaemolyticus pathogenicity is explored. The impact of new and much more effective PCR primers on V. parahaemolyticus detection and our views of virulent strain abundance are also described. It is clear that strains carrying the canonical virulence genes are far more common than previously thought, which opens questions regarding the role of these genes in pathogenesis. It is also clear that virulence is an evolving feature of V. parahaemolyticus and that novel combinations of virulence factors can lead to emergent virulence in which a strain that is markedly more pathogenic evolves and propagates to produce an outbreak. The effects of global climate change on the frequency of epidemic disease, the geographic distribution of outbreaks, and the human impacts of V. parahaemolyticus are increasing and this review provides information on why this ubiquitous human pathogen has

  4. Prevalence of clonal complexes and virulence genes among commensal and invasive Staphylococcus aureus isolates in Sweden.

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    Gunlög Rasmussen

    Full Text Available Staphylococcus aureus encodes a remarkable number of virulence factors which may contribute to its pathogenicity and ability to cause invasive disease. The main objective of this study was to evaluate the association between S. aureus invasiveness and bacterial genotype, in terms of the presence of virulence genes and affiliation to clonal complexes. Also, the significance of different virulence genes, mainly adhesins, for the development of infective endocarditis was investigated. DNA microarray technology was used to analyze 134 S. aureus isolates, all methicillin-susceptible, derived from three groups of clinically well-characterized patients: nasal carriers (n=46, bacteremia (n=55, and bacteremia with infective endocarditis (n=33. Invasive isolates were dominant in four of the major clonal complexes: 5, 8, 15, and 25. Of the 170 virulence genes examined, those encoding accessory gene regulator group II (agr II, capsule polysaccharide serotype 5 (cap5, and adhesins such as S. aureus surface protein G (sasG and fibronectin-binding protein B (fnbB were found to be associated with invasive disease. The same was shown for the leukocidin genes lukD/lukE, as well as the genes encoding serine protease A and B (splA/splB, staphylococcal complement inhibitor (scn and the staphylococcal exotoxin-like protein (setC or selX. In addition, there was a trend of higher prevalence of certain genes or gene clusters (sasG, agr II, cap5 among isolates causing infective endocarditis compared to other invasive isolates. In most cases, the presence of virulence genes was linked to clonal complex affiliation. In conclusion, certain S. aureus clonal lineages harboring specific sets of virulence genes seem to be more successful in causing invasive disease.

  5. Copper tolerance and virulence in bacteria

    Science.gov (United States)

    Ladomersky, Erik; Petris, Michael J.

    2015-01-01

    Copper (Cu) is an essential trace element for all aerobic organisms. It functions as a cofactor in enzymes that catalyze a wide variety of redox reactions due to its ability to cycle between two oxidation states, Cu(I) and Cu(II). This same redox property of copper has the potential to cause toxicity if copper homeostasis is not maintained. Studies suggest that the toxic properties of copper are harnessed by the innate immune system of the host to kill bacteria. To counter such defenses, bacteria rely on copper tolerance genes for virulence within the host. These discoveries suggest bacterial copper intoxication is a component of host nutritional immunity, thus expanding our knowledge of the roles of copper in biology. This review summarizes our current understanding of copper tolerance in bacteria, and the extent to which these pathways contribute to bacterial virulence within the host. PMID:25652326

  6. Riboregulators: Fine-Tuning Virulence in Shigella.

    Science.gov (United States)

    Fris, Megan E; Murphy, Erin R

    2016-01-01

    Within the past several years, RNA-mediated regulation (ribo-regulation) has become increasingly recognized for its importance in controlling critical bacterial processes. Regulatory RNA molecules, or riboregulators, are perpetually responsive to changes within the micro-environment of a bacterium. Notably, several characterized riboregulators control virulence in pathogenic bacteria, as is the case for each riboregulator characterized to date in Shigella. The timing of virulence gene expression and the ability of the pathogen to adapt to rapidly changing environmental conditions is critical to the establishment and progression of infection by Shigella species; ribo-regulators mediate each of these important processes. This mini review will present the current state of knowledge regarding RNA-mediated regulation in Shigella by detailing the characterization and function of each identified riboregulator in these pathogens.

  7. Household Finances and the 'Big Five' Personality Traits

    OpenAIRE

    Brown, Sarah; Taylor, Karl

    2011-01-01

    We explore the relationship between household finances and personality traits from an empirical perspective. Specifically, using individual level data drawn from the British Household Panel Survey, we analyse the influence of personality traits on financial decision-making at the individual level focusing on decisions regarding unsecured debt acquisition and financial assets. Personality traits are classified according to the 'Big Five' taxonomy: openness to experience, conscientiousness, ext...

  8. Virulence Factors of Erwinia amylovora: A Review

    Directory of Open Access Journals (Sweden)

    Núria Piqué

    2015-06-01

    Full Text Available Erwinia amylovora, a Gram negative bacteria of the Enterobacteriaceae family, is the causal agent of fire blight, a devastating plant disease affecting a wide range of host species within Rosaceae and a major global threat to commercial apple and pear production. Among the limited number of control options currently available, prophylactic application of antibiotics during the bloom period appears the most effective. Pathogen cells enter plants through the nectarthodes of flowers and other natural openings, such as wounds, and are capable of rapid movement within plants and the establishment of systemic infections. Many virulence determinants of E. amylovora have been characterized, including the Type III secretion system (T3SS, the exopolysaccharide (EPS amylovoran, biofilm formation, and motility. To successfully establish an infection, E. amylovora uses a complex regulatory network to sense the relevant environmental signals and coordinate the expression of early and late stage virulence factors involving two component signal transduction systems, bis-(3′-5′-cyclic di-GMP (c-di-GMP and quorum sensing. The LPS biosynthetic gene cluster is one of the relatively few genetic differences observed between Rubus- and Spiraeoideae-infecting genotypes of E. amylovora. Other differential factors, such as the presence and composition of an integrative conjugative element associated with the Hrp T3SS (hrp genes encoding the T3SS apparatus, have been recently described. In the present review, we present the recent findings on virulence factors research, focusing on their role in bacterial pathogenesis and indicating other virulence factors that deserve future research to characterize them.

  9. Positional RNA-Seq identifies candidate genes for phenotypic engineering of sexual traits

    NARCIS (Netherlands)

    Arbore, Roberto; Sekii, Kiyono; Beisel, Christian; Ladurner, Peter; Berezikov, Eugene; Schaerer, Lukas

    2015-01-01

    Introduction: RNA interference (RNAi) of trait-specific genes permits the manipulation of specific phenotypic traits ("phenotypic engineering") and thus represents a powerful tool to test trait function in evolutionary studies. The identification of suitable candidate genes, however, often relies on

  10. Virulence of a malaria parasite, Plasmodium mexicanum, for its sand fly vectors, Lutzomyia vexator and Lutzomyia stewarti (Diptera: Psychodidae).

    Science.gov (United States)

    Schall, Jos J

    2011-11-01

    Evolutionary theory predicts that virulence of parasites for mobile vector insects will be low for natural parasite-host associations that have coevolved. I determined virulence of the malaria parasite of lizards, Plasmodium mexicanum, for its vectors, two species of sand fly (Diptera: Psychodidae), Lutzomyia vexator (Coquillett 1907) and Lutzomyia stewarti (Mangabeira Fo & Galindo 1944), by measuring several life history traits. Developmental rate from egg to eclosion differed for the two species when noninfected. For both sand fly species, developmental rate for each stage (egg to larval hatching, larval period, pupal period) and life span were not altered by infection. Infected sand flies, however, produced fewer eggs. This reduction in fecundity may be a result of lower quality of the blood meal taken from infected lizards (lower concentration of hemoglobin). This report is the first measure of virulence of Plasmodium for an insect vector other than a mosquito and concords with both expectations of theory and previous studies on natural parasite-host associations that revealed low virulence.

  11. Power and Autistic Traits

    Directory of Open Access Journals (Sweden)

    Geir Overskeid

    2016-08-01

    Full Text Available Autistic traits can help people gain and sustain power, and has probably done so throughout history, says the present paper. A number of testable claims follow from this assumption. First, the powerful should have more autistic traits than others – which they do appear to have. Among other things, powerful people, and those with many autistic traits, tend to prefer solitary activities and are often aloof. Moreover, they are often rigid and socially insensitive, low on empathy and with low scores on the trait of agreeableness -- and as a rule they do not have many friends. Both groups are also more self-centered than others, more honest, less submissive, more sensitive to slights, and with a stronger tendency to engage in abstract thinking. They tend to behave in bossy or dominant ways, and their moral judgment is more based on rules than on feelings. In addition to experimental evidence, I cite biographies showing that a surprising number of presidents, prime ministers and other powerful people seem to have had traits like those in question – and interestingly, in animals, leaders are often rigid and insensitive to group members’ needs and feelings, mostly acting the way they are themselves inclined to, not responding much to others. Problem solving is important in leadership, and people with many autistic traits appear often to be better thinkers than typical subjects with similar IQs. However, these and other congruities could be coincidences. Hence the question of whether traits the two groups have in common also have a common cause constitutes a strong test of the paper’s thesis – and a common cause does appear to exist, in the form of testosterone’s effects on the central nervous system. Finally, there is evidence that, other things equal, powerful men have more reproductive success than others. If men wielding power do indeed have more autistic traits than those less powerful, this will lead to, other things equal, such traits

  12. Power and Autistic Traits

    Science.gov (United States)

    Overskeid, Geir

    2016-01-01

    Autistic traits can help people gain and sustain power, and has probably done so throughout history, says the present paper. A number of testable claims follow from this assumption. First, the powerful should have more autistic traits than others – which they do appear to have. Among other things, powerful people, and those with many autistic traits, tend to prefer solitary activities and are often aloof. Moreover, they are often rigid and socially insensitive, low on empathy and with low scores on the trait of agreeableness – and as a rule they do not have many friends. Both groups are also more self-centered than others, more honest, less submissive, more sensitive to slights, and with a stronger tendency to engage in abstract thinking. They tend to behave in bossy or dominant ways, and their moral judgment is more based on rules than on feelings. In addition to experimental evidence, I cite biographies showing that a surprising number of presidents, prime ministers and other powerful people seem to have had traits like those in question – and interestingly, in animals, leaders are often rigid and insensitive to group members’ needs and feelings, mostly acting the way they are themselves inclined to, not responding much to others. Problem solving is important in leadership, and people with many autistic traits appear often to be better thinkers than typical subjects with similar IQs. However, these and other congruities could be coincidences. Hence the question of whether traits the two groups have in common also have a common cause constitutes a strong test of the paper’s thesis – and a common cause does appear to exist, in the form of testosterone’s effects on the central nervous system. Finally, there is evidence that, other things equal, powerful men have more reproductive success than others. If men wielding power do indeed have more autistic traits than those less powerful, this will lead to, other things equal, such traits becoming more

  13. Comparative Transcriptome Analysis of Salivary Glands of Two Populations of Rice Brown Planthopper, Nilaparvata lugens, That Differ in Virulence

    Science.gov (United States)

    Chen, Hongdan; Ye, Wenfeng; Li, Shaohui; Lou, Yonggen

    2013-01-01

    Background The brown planthopper (BPH), Nilaparvata lugens (Stål), a destructive rice pest in Asia, can quickly overcome rice resistance by evolving new virulent populations. Herbivore saliva plays an important role in plant–herbivore interactions, including in plant defense and herbivore virulence. However, thus far little is known about BPH saliva at the molecular level, especially its role in virulence and BPH–rice interaction. Methodology/Principal Findings Using cDNA amplification in combination with Illumina short-read sequencing technology, we sequenced the salivary-gland transcriptomes of two BPH populations with different virulence; the populations were derived from rice variety TN1 (TN1 population) and Mudgo (M population). In total, 37,666 and 38,451 unigenes were generated from the salivary glands of these populations, respectively. When combined, a total of 43,312 unigenes were obtained, about 18 times more than the number of expressed sequence tags previously identified from these glands. Gene ontology annotations and KEGG orthology classifications indicated that genes related to metabolism, binding and transport were significantly active in the salivary glands. A total of 352 genes were predicted to encode secretory proteins, and some might play important roles in BPH feeding and BPH–rice interactions. Comparative analysis of the transcriptomes of the two populations revealed that the genes related to ‘metabolism,’ ‘digestion and absorption,’ and ‘salivary secretion’ might be associated with virulence. Moreover, 67 genes encoding putative secreted proteins were differentially expressed between the two populations, suggesting these genes may contribute to the change in virulence. Conclusions/Significance This study was the first to compare the salivary-gland transcriptomes of two BPH populations having different virulence traits and to find genes that may be related to this difference. Our data provide a rich molecular resource for

  14. Comparative genomic analysis of Vibrio parahaemolyticus: serotype conversion and virulence

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    Gil Ana I

    2011-06-01

    Full Text Available Abstract Background Vibrio parahaemolyticus is a common cause of foodborne disease. Beginning in 1996, a more virulent strain having serotype O3:K6 caused major outbreaks in India and other parts of the world, resulting in the emergence of a pandemic. Other serovariants of this strain emerged during its dissemination and together with the original O3:K6 were termed strains of the pandemic clone. Two genomes, one of this virulent strain and one pre-pandemic strain have been sequenced. We sequenced four additional genomes of V. parahaemolyticus in this study that were isolated from different geographical regions and time points. Comparative genomic analyses of six strains of V. parahaemolyticus isolated from Asia and Peru were performed in order to advance knowledge concerning the evolution of V. parahaemolyticus; specifically, the genetic changes contributing to serotype conversion and virulence. Two pre-pandemic strains and three pandemic strains, isolated from different geographical regions, were serotype O3:K6 and either toxin profiles (tdh+, trh- or (tdh-, trh+. The sixth pandemic strain sequenced in this study was serotype O4:K68. Results Genomic analyses revealed that the trh+ and tdh+ strains had different types of pathogenicity islands and mobile elements as well as major structural differences between the tdh pathogenicity islands of the pre-pandemic and pandemic strains. In addition, the results of single nucleotide polymorphism (SNP analysis showed that 94% of the SNPs between O3:K6 and O4:K68 pandemic isolates were within a 141 kb region surrounding the O- and K-antigen-encoding gene clusters. The "core" genes of V. parahaemolyticus were also compared to those of V. cholerae and V. vulnificus, in order to delineate differences between these three pathogenic species. Approximately one-half (49-59% of each species' core genes were conserved in all three species, and 14-24% of the core genes were species-specific and in different

  15. Assessing Pseudomonas virulence with a nonmammalian host: Drosophila melanogaster.

    Science.gov (United States)

    Haller, Samantha; Limmer, Stefanie; Ferrandon, Dominique

    2014-01-01

    Drosophila melanogaster flies represent an interesting model to study host-pathogen interactions as: (1) they are cheap and easy to raise rapidly and do not bring up ethical issues, (2) available genetic tools are highly sophisticated, for instance allowing tissue-specific alteration of gene expression, e.g., of immune genes, (3) they have a relatively complex organization, with distinct digestive tract and body cavity in which local or systemic infections, respectively, take place, (4) a medium throughput can be achieved in genetic screens, for instance looking for Pseudomonas aeruginosa mutants with altered virulence. We present here the techniques used to investigate host-pathogen relationships, namely the two major models of infections as well as the relevant parameters used to monitor the infection (survival, bacterial titer, induction of host immune response).

  16. Trait vs. state anxiety in different threatening situations

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    Pollyana Caldeira Leal

    2017-08-01

    Full Text Available Abstract Objective Anxiety as a uni- or multidimensional construct has been under discussion. The unidimensional approach assumes that there is a general trait anxiety, which predisposes the individuals to increases in state anxiety in various threatening situations. In this case, there should be a correlation between state and trait anxiety in any situation of threat. Therefore, the aim of this study was to investigate the correlation between trait and state anxiety in participants exposed to two different anxiogenic situations: interpersonal threat (Video-Monitored Stroop Test – VMST and physical threat (third molar extraction – TME. Methods Participants with various levels of trait anxiety (general trait: State-Trait Anxiety Inventory – STAI, Hospital Anxiety and Depression Scale; specific trait: Social Phobia Inventory, Dental Anxiety Scale had their anxious state evaluated (STAI, self-evaluation of tension level, heart rate, electromyogram activity before, during and after the VMST or the TME. Results In VMST, trait anxiety correlated to state anxiety (psychological parameters in all test phases. However, in TME, the only trait measurement that correlated to state anxiety (psychological parameters was the Dental Anxiety Scale. Conclusion Trait anxiety correlates positively to state anxiety in situations of interpersonal threat, but not of physical threat.

  17. Virulence of Rhodococcus equi Isolated from Cats and Dogs

    OpenAIRE

    Takai, Shinji; Martens, Ronald J.; Julian, Alan; Garcia Ribeiro, Márcio; Rodrigues de Farias, Marconi; Sasaki, Yukako; Inuzuka, Kazuho; Kakuda, Tsutomu; Tsubaki, Shiro; Prescott, John F.

    2003-01-01

    Nine cat isolates and nine dog isolates of Rhodococcus equi from clinical material were investigated for the presence of the virulence-associated antigens (VapA and VapB) and virulence plasmids. Five of the cat isolates and one dog isolate were VapA positive and contained an 85-kb type I or an 87-kb type I plasmid. The remaining 12 isolates were avirulent R. equi strains and contained no virulence plasmids.

  18. The Hidden Complexity of Mendelian Traits across Natural Yeast Populations

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    Jing Hou

    2016-07-01

    Full Text Available Mendelian traits are considered to be at the lower end of the complexity spectrum of heritable phenotypes. However, more than a century after the rediscovery of Mendel’s law, the global landscape of monogenic variants, as well as their effects and inheritance patterns within natural populations, is still not well understood. Using the yeast Saccharomyces cerevisiae, we performed a species-wide survey of Mendelian traits across a large population of isolates. We generated offspring from 41 unique parental pairs and analyzed 1,105 cross/trait combinations. We found that 8.9% of the cases were Mendelian. Further tracing of causal variants revealed background-specific expressivity and modified inheritances, gradually transitioning from Mendelian to complex traits in 30% of the cases. In fact, when taking into account the natural population diversity, the hidden complexity of traits could be substantial, confounding phenotypic predictability even for simple Mendelian traits.

  19. Brain Region-Specific Expression of Genes Mapped within Quantitative Trait Loci for Behavioral Responsiveness to Acute Stress in Fisher 344 and Wistar Kyoto Male Rats (Open Access Postprint)

    Science.gov (United States)

    2018-03-12

    responsiveness to acute stress in Fisher 344 and Wistar Kyoto male rats. PLoS ONE 13(3): e0194293. https://doi. org /10.1371/journal.pone.0194293 Editor...mapping analysis of complex traits in outbred rats. Nature genetics. 2013; 45(7): https://doi. org /10.1038/ng.2644 PMC3821058. PMID: 23708188 15...assisted breeding of congenic mouse strains. Nature Genetics. 1997; 17:280. https://doi. org /10.1038/ng1197-280 PMID: 9354790 21. The SC. SNP and haplotype

  20. Presence of virulence factors in Enterococcus faecalis and Enterococcus faecium susceptible and resistant to vancomycin

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    Carolina Baldisserotto Comerlato

    2013-08-01

    Full Text Available Despite the increasing importance of Enterococcus as opportunistic pathogens, their virulence factors are still poorly understood. This study determines the frequency of virulence factors in clinical and commensal Enterococcus isolates from inpatients in Porto Alegre, Brazil. Fifty Enterococcus isolates were analysed and the presence of the gelE, asa1 and esp genes was determined. Gelatinase activity and biofilm formation were also tested. The clonal relationships among the isolates were evaluated using pulsed-field gel electrophoresis. The asa1, gelE and esp genes were identified in 38%, 60% and 76% of all isolates, respectively. The first two genes were more prevalent in Enterococcus faecalis than in Enterococcus faecium, as was biofilm formation, which was associated with gelE and asa1 genes, but not with the esp gene. The presence of gelE and the activity of gelatinase were not fully concordant. No relationship was observed among any virulence factors and specific subclones of E. faecalis or E. faecium resistant to vancomycin. In conclusion, E. faecalis and E. faecium isolates showed significantly different patterns of virulence determinants. Neither the source of isolation nor the clonal relationship or vancomycin resistance influenced their distribution.

  1. Phenotypic Characteristics Associated with Virulence of Clinical Isolates from the Sporothrix Complex

    Science.gov (United States)

    Almeida-Paes, Rodrigo; de Oliveira, Luã Cardoso; Oliveira, Manoel Marques Evangelista; Gutierrez-Galhardo, Maria Clara; Nosanchuk, Joshua Daniel; Zancopé-Oliveira, Rosely Maria

    2015-01-01

    The Sporothrix complex members cause sporotrichosis, a subcutaneous mycosis with a wide spectrum of clinical manifestations. Several specific phenotypic characteristics are associated with virulence in many fungi, but studies in this field involving the Sporothrix complex species are scarce. Melanization, thermotolerance, and production of proteases, catalase, and urease were investigated in 61 S. brasiliensis, one S. globosa, and 10 S. schenckii strains. The S. brasiliensis strains showed a higher expression of melanin and urease compared with S. schenckii. These two species, however, presented similar thermotolerances. Our S. globosa strain had low expression of all studied virulence factors. The relationship between these phenotypes and clinical aspects of sporotrichosis was also evaluated. Strains isolated from patients with spontaneous regression of infection were heavily melanized and produced high urease levels. Melanin was also related to dissemination of internal organs and protease production was associated with HIV-coinfection. A murine sporotrichosis model showed that a S. brasiliensis strain with high expression of virulence factors was able to disseminate and yield a high fungal burden in comparison with a control S. schenckii strain. Our results show that virulence-related phenotypes are variably expressed within the Sporothrix complex species and might be involved in clinical aspects of sporotrichosis. PMID:25961005

  2. Genome-wide screen of Pseudomonas aeruginosa In Saccharomyces cerevisiae identifies new virulence factors

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    Rafat eZrieq

    2015-11-01

    Full Text Available Pseudomonas aeruginosa is a human opportunistic pathogen that causes mortality in cystic fibrosis and immunocompromised patients. While many virulence factors of this pathogen have already been identified, several remain to be discovered. In this respect we set an unprecedented genome-wide screen of a P. aeruginosa expression library based on a yeast growth phenotype. 51 candidates were selected in a three-round screening process. The robustness of the screen was validated by the selection of three well known secreted proteins including one demonstrated virulence factor, the protease LepA. Further in silico sorting of the 51 candidates highlighted three potential new Pseudomonas effector candidates (Pec. By testing the cytotoxicity of wild type P. aeruginosa vs pec mutants towards macrophages and the virulence in the Caenorhabditis elegans model, we demonstrated that the three selected Pecs are novel virulence factors of P. aeruginosa. Additional cellular localization experiments in the host revealed specific localization for Pec1 and Pec2 that could inform about their respective functions.

  3. Genetic diversity, virulence and fitness evolution in an obligate fungal parasite of bees.

    Science.gov (United States)

    Evison, S E F; Foley, K; Jensen, A B; Hughes, W O H

    2015-01-01

    Within-host competition is predicted to drive the evolution of virulence in parasites, but the precise outcomes of such interactions are often unpredictable due to many factors including the biology of the host and the parasite, stochastic events and co-evolutionary interactions. Here, we use a serial passage experiment (SPE) with three strains of a heterothallic fungal parasite (Ascosphaera apis) of the Honey bee (Apis mellifera) to assess how evolving under increasing competitive pressure affects parasite virulence and fitness evolution. The results show an increase in virulence after successive generations of selection and consequently faster production of spores. This faster sporulation, however, did not translate into more spores being produced during this longer window of sporulation; rather, it appeared to induce a loss of fitness in terms of total spore production. There was no evidence to suggest that a greater diversity of competing strains was a driver of this increased virulence and subsequent fitness cost, but rather that strain-specific competitive interactions influenced the evolutionary outcomes of mixed infections. It is possible that the parasite may have evolved to avoid competition with multiple strains because of its heterothallic mode of reproduction, which highlights the importance of understanding parasite biology when predicting disease dynamics. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  4. A preliminary survey of M. hyopneumoniae virulence factors based on comparative genomic analysis

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    Henrique Bunselmeyer Ferreira

    2007-01-01

    Full Text Available Mycoplasma hyopneumoniae is the etiological agent of porcine enzootic pneumonia (PEP, a major problem for the pig industry. The mechanisms of M. hyopneumoniae pathogenicity allow to predict the existence of several classes of virulence factors, whose study has been essentially restricted to the characterization of adhesion-related and major antigenic proteins. The now available complete sequences of the genomes of two pathogenic and one non-pathogenic strain of M. hyopneumoniae allowed to use a comparative genomics approach to putatively identify virulence genes. In this preliminary survey, we were able to identify 118 CDSs encoding putative virulence factors, based on specific criteria ranging from predicted cell surface location or variation between strains to previous functional studies showing antigenicity or involvement in host-pathogen interaction. This survey is expected to serve as a first step towards the functional characterization of new virulence genes/proteins that will be important not only for a better comprehension of M. hyopneumoniae biology, but also for the development of new and improved protocols for PEP vaccination, diagnosis and treatment.

  5. Evolution and Virulence of Influenza A Virus Protein PB1-F2

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    Ram P. Kamal

    2017-12-01

    Full Text Available PB1-F2 is an accessory protein of most human, avian, swine, equine, and canine influenza A viruses (IAVs. Although it is dispensable for virus replication and growth, it plays significant roles in pathogenesis by interfering with the host innate immune response, inducing death in immune and epithelial cells, altering inflammatory responses, and promoting secondary bacterial pneumonia. The effects of PB1-F2 differ between virus strains and host species. This can at least partially be explained by the presence of multiple PB1-F2 sequence variants, including premature stop codons that lead to the expression of truncated PB1-F2 proteins of different lengths and specific virulence-associated residues that enhance susceptibility to bacterial superinfection. Although there has been a tendency for human seasonal IAV to gradually reduce the number of virulence-associated residues, zoonotic IAVs contain a reservoir of PB1-F2 proteins with full length, virulence-associated sequences. Here, we review the molecular mechanisms by which PB1-F2 may affect influenza virulence, and factors associated with the evolution and selection of this protein.

  6. [Effect of the 10 kb sequence of piscine Streptococcus agalactiae on bacterial virulence].

    Science.gov (United States)

    Liu, Guangjin; Zhu, Jielian; Shi, Ziwei; Ding, Ming; Wang, Ruyi; Yao, Huochun; Lu, Chengping; Xu, Pao

    2016-01-04

    From the previous comparative genomic analysis, we found a specific unknown 10 kb sequence (including 11 Open reading Frames) in Chinese piscine strain GD201008-001 genome. To study the role of 10 kb in the pathogenicity of piscine S. agalactiae, the 10 kb sequence was deleted from the GD201008-001 genome. The isogenic mutant Δ10 kb was constructed by using the temperature-sensitive Streptococcus-E. coli shuttle vector pSET4s. We compared the growth characteristics, adherence to HEp-2 cell and bacterial virulence in a zebrafish infection model between wild strain and mutant. Meanwhile the expressions of the known virulence genes from GD201008-001 and Δ10 kb were also quantified by real-time PCR. The Δ10 kb showed no significant differences in bacterial morphology and adherence to HEp-2 cells compared with the wild-type strain, but the speed of growth was slightly slower than the wild strain. Furthermore the 50% lethal dose of Δ10 kb was decreased up to 10-fold (P kb sequence of piscine Streptococcus agalactiae exerts a significant effect on bacterial virulence and probably regulates the virulence genes expression of GD20 1008-001.

  7. Mutations induced by ultraviolet radiation affecting virulence in Puccinia striiformis

    International Nuclear Information System (INIS)

    Shang Hongsheng; Jing Jinxue; Li Zhenqi

    1994-01-01

    Uredospores of parent culture, cy 29-1, were treated by ultraviolet radiation and mutations to virulent were tested on resistant wheat cultivars inoculated with treated spores. 7 mutant cultures virulent to the test cultivars were developed with estimated mutation rate 10~6~10~4. The virulence of mutant cultures was different from the all known races of stripe rust. Resistance segregation to mutant cultures was detected in two test cultivars. The results suggested that mutation was important mechanism of virulence variation operative in asexual population of rust fungi

  8. Limiting opportunities for cheating stabilizes virulence in insect parasitic nematodes.

    Science.gov (United States)

    Shapiro-Ilan, David; Raymond, Ben

    2016-03-01

    Cooperative secretion of virulence factors by pathogens can lead to social conflict when cheating mutants exploit collective secretion, but do not contribute to it. If cheats outcompete cooperators within hosts, this can cause loss of virulence. Insect parasitic nematodes are important biocontrol tools that secrete a range of significant virulence factors. Critically, effective nematodes are hard to maintain without live passage, which can lead to virulence attenuation. Using experimental evolution, we tested whether social cheating might explain unstable virulence in the nematode Heterorhabditis floridensis by manipulating relatedness via multiplicity of infection (MOI), and the scale of competition. Passage at high MOI, which should reduce relatedness, led to loss of fitness: virulence and reproductive rate declined together and all eight independent lines suffered premature extinction. As theory predicts, relatedness treatments had more impact under stronger global competition. In contrast, low MOI passage led to more stable virulence and increased reproduction. Moreover, low MOI lineages showed a trade-off between virulence and reproduction, particularly for lines under stronger between-host competition. Overall, this study indicates that evolution of virulence theory is valuable for the culture of biocontrol agents: effective nematodes can be improved and maintained if passage methods mitigate possible social conflicts.

  9. Root traits contributing to plant productivity under drought

    Directory of Open Access Journals (Sweden)

    Louise eComas

    2013-11-01

    Full Text Available Geneticists and breeders are positioned to breed plants with root traits that improve productivity under drought. However, a better understanding of root functional traits and how traits are related to whole plant strategies to increase crop productivity under different drought conditions is needed. Root traits associated with maintaining plant productivity under drought include small fine root diameters, long specific root length (SRL, and considerable root length density, especially at depths in soil with available water. In environments with late season water deficits, small xylem diameters in targeted seminal roots save soil water deep in the soil profile for use during crop maturation and result in improved yields. Capacity for deep root growth and large xylem diameters in deep roots may also improve root acquisition of water when ample water at depth is available. Xylem pit anatomy that makes xylem less ‘leaky’ and prone to cavitation warrants further exploration holding promise that such traits may improve plant productivity in water-limited environments without negatively impacting yield under adequate water conditions. Rapid resumption of root growth following soil rewetting may improve plant productivity under episodic drought. Genetic control of many of these traits through breeding appears feasible. Several recent reviews have covered methods for screening root traits but an appreciation for the complexity of root systems (e.g. functional differences between fine and coarse roots needs to be paired with these methods to successfully identify relevant traits for crop improvement. Screening of root traits at early stages in plant development can proxy traits at mature stages but verification is needed on a case by case basis that traits are linked to increased crop productivity under drought. Examples in lesquerella (Physaria and rice (Oryza show approaches to phenotyping of root traits and current understanding of root trait

  10. Comparative Genomics of Mycoplasma bovis Strains Reveals That Decreased Virulence with Increasing Passages Might Correlate with Potential Virulence-Related Factors

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    Muhammad A. Rasheed

    2017-05-01

    Full Text Available Mycoplasma bovis is an important cause of bovine respiratory disease worldwide. To understand its virulence mechanisms, we sequenced three attenuated M. bovis strains, P115, P150, and P180, which were passaged in vitro 115, 150, and 180 times, respectively, and exhibited progressively decreasing virulence. Comparative genomics was performed among the wild-type M. bovis HB0801 (P1 strain and the P115, P150, and P180 strains, and one 14.2-kb deleted region covering 14 genes was detected in the passaged strains. Additionally, 46 non-sense single-nucleotide polymorphisms and indels were detected, which confirmed that more passages result in more mutations. A subsequent collective bioinformatics analysis of paralogs, metabolic pathways, protein-protein interactions, secretory proteins, functionally conserved domains, and virulence-related factors identified 11 genes that likely contributed to the increased attenuation in the passaged strains. These genes encode ascorbate-specific phosphotransferase system enzyme IIB and IIA components, enolase, L-lactate dehydrogenase, pyruvate kinase, glycerol, and multiple sugar ATP-binding cassette transporters, ATP binding proteins, NADH dehydrogenase, phosphate acetyltransferase, transketolase, and a variable surface protein. Fifteen genes were shown to be enriched in 15 metabolic pathways, and they included the aforementioned genes encoding pyruvate kinase, transketolase, enolase, and L-lactate dehydrogenase. Hydrogen peroxide (H2O2 production in M. bovis strains representing seven passages from P1 to P180 decreased progressively with increasing numbers of passages and increased attenuation. However, eight mutants specific to eight individual genes within the 14.2-kb deleted region did not exhibit altered H2O2 production. These results enrich the M. bovis genomics database, and they increase our understanding of the mechanisms underlying M. bovis virulence.

  11. Omics strategies for revealing Yersinia pestis virulence

    Science.gov (United States)

    Yang, Ruifu; Du, Zongmin; Han, Yanping; Zhou, Lei; Song, Yajun; Zhou, Dongsheng; Cui, Yujun

    2012-01-01

    Omics has remarkably changed the way we investigate and understand life. Omics differs from traditional hypothesis-driven research because it is a discovery-driven approach. Mass datasets produced from omics-based studies require experts from different fields to reveal the salient features behind these data. In this review, we summarize omics-driven studies to reveal the virulence features of Yersinia pestis through genomics, trascriptomics, proteomics, interactomics, etc. These studies serve as foundations for further hypothesis-driven research and help us gain insight into Y. pestis pathogenesis. PMID:23248778

  12. Virulence determinants of pandemic influenza viruses

    Science.gov (United States)

    Tscherne, Donna M.; García-Sastre, Adolfo

    2011-01-01

    Influenza A viruses cause recurrent, seasonal epidemics and occasional global pandemics with devastating levels of morbidity and mortality. The ability of influenza A viruses to adapt to various hosts and undergo reassortment events ensures constant generation of new strains with unpredictable degrees of pathogenicity, transmissibility, and pandemic potential. Currently, the combination of factors that drives the emergence of pandemic influenza is unclear, making it impossible to foresee the details of a future outbreak. Identification and characterization of influenza A virus virulence determinants may provide insight into genotypic signatures of pathogenicity as well as a more thorough understanding of the factors that give rise to pandemics. PMID:21206092

  13. Metal acquisition and virulence in Brucella

    Science.gov (United States)

    Roop, R. Martin

    2013-01-01

    Similar to other bacteria, Brucella strains require several biologically essential metals for their survival in vitro and in vivo. Acquiring sufficient levels of some of these metals, particularly iron, manganese and zinc, is especially challenging in the mammalian host, where sequestration of these micronutrients is a well-documented component of both the innate and acquired immune responses. This review describes the Brucella metal transporters that have been shown to play critical roles in the virulence of these bacteria in experimental and natural hosts. PMID:22632611

  14. CK2 Secreted by Leishmania braziliensis Mediates Macrophage Association Invasion: A Comparative Study between Virulent and Avirulent Promastigotes

    Directory of Open Access Journals (Sweden)

    Ana Madeira Brito Zylbersztejn

    2015-01-01

    Full Text Available CK2 is a protein kinase distributed in different compartments of Leishmania braziliensis: an externally oriented ecto-CK2, an intracellular CK2, and a secreted CK2. This latter form is constitutively secreted from the parasite (CsCK2, but such secretion may be highly enhanced by the association of specific molecules, including enzyme substrates, which lead to a higher enzymatic activity, called inductively secreted CK2 (IsCK2. Here, we examined the influence of secreted CK2 (sCK2 activity on the infectivity of a virulent L. braziliensis strain. The virulent strain presented 121-fold higher total CK2 activity than those found in an avirulent strain. The use of specific CK2 inhibitors (TBB, DRB, or heparin inhibited virulent parasite growth, whereas no effect was observed in the avirulent parasites. When these inhibitors were added to the interaction assays between the virulent L. braziliensis strain and macrophages, association index was drastically inhibited. Polyamines enhanced sCK2 activity and increased the association index between parasites and macrophages. Finally, sCK2 and the supernatant of the virulent strain increased the association index between the avirulent strain and macrophages, which was inhibited by TBB. Thus, the kinase enzyme CK2 seems to be important to invasion mechanisms of L. braziliensis.

  15. Allele-dependent differences in quorum-sensing dynamics result in variant expression of virulence genes in Staphylococcus aureus.

    Science.gov (United States)

    Geisinger, Edward; Chen, John; Novick, Richard P

    2012-06-01

    Agr is an autoinducing, quorum-sensing system that functions in many Gram-positive species and is best characterized in the pathogen Staphylococcus aureus, in which it is a global regulator of virulence gene expression. Allelic variations in the agr genes have resulted in the emergence of four quorum-sensing specificity groups in S. aureus, which correlate with different strain pathotypes. The basis for these predilections is unclear but is hypothesized to involve the phenomenon of quorum-sensing interference between strains of different agr groups, which may drive S. aureus strain isolation and divergence. Whether properties intrinsic to each agr allele directly influence virulence phenotypes within S. aureus is unknown. In this study, we examined group-specific differences in agr autoinduction and virulence gene regulation by utilizing congenic strains, each harboring a unique S. aureus agr allele, enabling a dissection of agr locus-dependent versus genotype-dependent effects on quorum-sensing dynamics and virulence factor production. Employing a reporter fusion to the principal agr promoter, P3, we observed allele-dependent differences in the timing and magnitude of agr activation. These differences were mediated by polymorphisms within the agrBDCA genes and translated to significant variations in the expression of a key transcriptional regulator, Rot, and of several important exoproteins and surface factors involved in pathogenesis. This work uncovers the contribution of divergent quorum-sensing alleles to variant expression of virulence determinants within a bacterial species.

  16. RgpF Is Required for Maintenance of Stress Tolerance and Virulence in Streptococcus mutans.

    Science.gov (United States)

    Kovacs, C J; Faustoferri, R C; Quivey, R G

    2017-12-15

    Bacterial cell wall dynamics have been implicated as important determinants of cellular physiology, stress tolerance, and virulence. In Streptococcus mutans , the cell wall is composed primarily of a rhamnose-glucose polysaccharide (RGP) linked to the peptidoglycan. Despite extensive studies describing its formation and composition, the potential roles for RGP in S. mutans biology have not been well investigated. The present study characterizes the impact of RGP disruption as a result of the deletion of rgpF , the gene encoding a rhamnosyltransferase involved in the construction of the core polyrhamnose backbone of RGP. The Δ rgpF mutant strain displayed an overall reduced fitness compared to the wild type, with heightened sensitivities to various stress-inducing culture conditions and an inability to tolerate acid challenge. The loss of rgpF caused a perturbation of membrane-associated functions known to be critical for aciduricity, a hallmark of S. mutans acid tolerance. The proton gradient across the membrane was disrupted, and the Δ rgpF mutant strain was unable to induce activity of the F 1 F o ATPase in cultures grown under low-pH conditions. Further, the virulence potential of S. mutans was also drastically reduced following the deletion of rgpF The Δ rgpF mutant strain produced significantly less robust biofilms, indicating an impairment in its ability to adhere to hydroxyapatite surfaces. Additionally, the Δ rgpF mutant lost competitive fitness against oral peroxigenic streptococci, and it displayed significantly attenuated virulence in an in vivo Galleria mellonella infection model. Collectively, these results highlight a critical function of the RGP in the maintenance of overall stress tolerance and virulence traits in S. mutans IMPORTANCE The cell wall of Streptococcus mutans , the bacterium most commonly associated with tooth decay, is abundant in rhamnose-glucose polysaccharides (RGP). While these structures are antigenically distinct to S. mutans

  17. Quantitative Trait Loci Affecting Calving Traits in Danish Holstein Cattle

    DEFF Research Database (Denmark)

    Thomasen, J R; Guldbrandtsen, B; Sørensen, P

    2008-01-01

    The objectives of this study were 1) to detect quantitative trait loci (QTL) affecting direct and maternal calving traits at first calving in the Danish Holstein population, 2) to distinguish between pleiotropic and linked QTL for chromosome regions affecting more than one trait, and 3) to detect...

  18. Quantitative trait loci for behavioural traits in chicken

    NARCIS (Netherlands)

    Buitenhuis, A.J.; Rodenburg, T.B.; Siwek, M.Z.; Cornelissen, S.J.B.; Nieuwland, M.G.B.; Crooijmans, R.P.M.A.; Groenen, M.A.M.; Koene, P.; Bovenhuis, H.; Poel, van der J.J.

    2005-01-01

    The detection of quantitative trait loci (QTL) of behavioural traits has mainly been focussed on mouse and rat. With the rapid development of molecular genetics and the statistical tools, QTL mapping for behavioural traits in farm animals is developing. In chicken, a total of 30 QTL involved in

  19. Plant functional traits predict green roof ecosystem services.

    Science.gov (United States)

    Lundholm, Jeremy; Tran, Stephanie; Gebert, Luke

    2015-02-17

    Plants make important contributions to the services provided by engineered ecosystems such as green roofs. Ecologists use plant species traits as generic predictors of geographical distribution, interactions with other species, and ecosystem functioning, but this approach has been little used to optimize engineered ecosystems. Four plant species traits (height, individual leaf area, specific leaf area, and leaf dry matter content) were evaluated as predictors of ecosystem properties and services in a modular green roof system planted with 21 species. Six indicators of ecosystem services, incorporating thermal, hydrological, water quality, and carbon sequestration functions, were predicted by the four plant traits directly or indirectly via their effects on aggregate ecosystem properties, including canopy density and albedo. Species average height and specific leaf area were the most useful traits, predicting several services via effects on canopy density or growth rate. This study demonstrates that easily measured plant traits can be used to select species to optimize green roof performance across multiple key services.

  20. Virulence-associated gene profiling of Streptococcus suis isolates by PCR

    NARCIS (Netherlands)

    Silva, L.M.G.; Baums, C.G.; Rehm, T.; Wisselink, H.J.; Goethe, R.; Valentin-Weigand, P.

    2006-01-01

    Definition of virulent Streptococcus suis strains is controversial. One successful approach for identification of virulent European strains is differentiation of capsular serotypes (or the corresponding cps types) and subsequent detection of virulence-associated factors, namely the extracellular

  1. Transdiagnostic cognitive processes in high trait anger.

    Science.gov (United States)

    Owen, John M

    2011-03-01

    Trait anger is a personality construct that refers to stable individual differences in the propensity to experience anger as an emotional state. The objective of this paper is to review relevant empirical studies in order to determine whether the transdiagnostic cognitive processes that have been identified across the DSM-IV Axis I disorders (specifically, selective attention, memory biases, reasoning biases and recurrent negative thinking) are also an underlying characteristic of high trait anger. On the basis of the review it is concluded that, whilst the research base is limited, there is good evidence that high trait anger is associated with selective attention to hostile social cues, the tendency to interpret the behaviour of others as indicating potential hostility and the tendency to ruminate over past anger-provoking experiences. The range of cognitive processes identified in high trait anger is consistent with those identified in the Axis I disorders. It is concluded that these findings provide support for (i) the broad applicability of the transdiagnostic approach as a theoretical framework for understanding a range of psychological conditions, not limited to the Axis I disorders, and (ii) the validity of conceptualising high trait anger as an aspect of personality functioning that is maintained, at least in part, by cognitive processes. Cognitive and motivational factors (specifically, beliefs and goals) that may underlie the hostile information-processing biases and recurrent negative thinking associated with high trait anger are discussed, and consideration is given to the clinical relevance of the findings of the review. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. [Virulence of Sporothrix globosa in murine models].

    Science.gov (United States)

    Cruz Choappa, Rodrigo; Pérez Gaete, Salomón; Rodríguez Badilla, Valentina; Vieille Oyarzo, Peggy; Opazo Sanchez, Héctor

    The sporothricosis disease is an infection caused by species included in Sporothrix schenkii complex. Verify the virulence of a strain of S. globosa using two different concentrations of inoculum by intraperitoneally and subcutaneously, into a mouse model. Nonrandomized pilot study, in murine inoculated with a strain of S. globosa (CBS 14.076M) by intraperitoneally and subcutaneously with inoculum concentrations of 0.5 and 4 McFarland. For this purpose 18 rodents CF-1 (ISP, Santiago, Chile) were used. The studied strain did not induce illness or injury on animals, they all survived and neither the tissue culture nor the histopathological analysis showed fungal growth or suggestive infection by organ abnormalities. The S. globosa strain did not present any virulence enough to cause disease at 0.5 and 4.0 McFarland concentration inoculum when inoculated in both intraperitoneally and subcutaneously, in murine models. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Porphyromonas gingivalis : Its virulence and vaccine

    Directory of Open Access Journals (Sweden)

    Nymphea Pandit

    2015-01-01

    Full Text Available Background: The microbial florae in adult periodontitis lesions are comprised of anaerobic rods with Porphyromonas gingivalis as one of the major components (Slots 1976; Slots 1979; and Tanner et al., 1979. P. gingivalis is a black-pigmented gram-negative anaerobic rod and a secondary colonizer of dental plaque requiring antecedent organisms. The presence of this organism either alone or as a mixed infection with other bacteria and with the absence of beneficial species appears to be essential for disease activity. It is a predominant member of the subgingival microbiota in disease. It possesses and "excretes" numerous potentially toxic virulence factors. Aim of this study is to perform a systematic review of studies on P. gingivalis and its virulence factors with a special focus on its vaccine. Materials and Methods: An electronic and manual search based on agreed search phrases between the primary investigator and a secondary investigator was performed for the literature review till January 2014. The articles that were identified by this systematic review (total of 190 were analyzed in detail, which included the study of inference and conclusion. Conclusions: Within the limits of this systematic review, it can be concluded that P. gingivalis induce immune inflammatory response in periodontitis subjects. Therapeutic vaccines need to be developed and studied for their efficacy in controlling periodontitis.

  4. Metabolism and virulence in Neisseria meningitidis

    Directory of Open Access Journals (Sweden)

    Christoph eSchoen

    2014-08-01

    Full Text Available A longstanding question in infection biology addresses the genetic basis for invasive behaviour in commensal pathogens. A prime example for such a pathogen is Neisseria meningitidis. On the one hand it is a harmless commensal bacterium exquisitely adapted to humans, and on the other hand it sometimes behaves like a ferocious pathogen causing potentially lethal disease such as sepsis and acute bacterial meningitis. Despite the lack of a classical repertoire of virulence genes in N. meningitidis separating commensal from invasive strains, molecular epidemiology suggests that carriage and invasive strains belong to genetically distinct populations. In recent years, it has become increasingly clear that metabolic adaptation enables meningococci to exploit host resources, supporting the concept of nutritional virulence as a crucial determinant of invasive capability. Here, we discuss the contribution of core metabolic pathways in the context of colonization and invasion with special emphasis on results from genome-wide surveys. The metabolism of lactate, the oxidative stress response, and, in particular, glutathione metabolism as well as the denitrification pathway provide examples of how meningococcal metabolism is intimately linked to pathogenesis. We further discuss evidence from genome-wide approaches regarding potential metabolic differences between strains from hyperinvasive and carriage lineages and present new data assessing in vitro growth differences of strains from these two populations. We hypothesize that strains from carriage and hyperinvasive lineages differ in the expression of regulatory genes involved particularly in stress responses and amino acid metabolism under infection conditions.

  5. Trait Emotional Intelligence and Personality

    OpenAIRE

    Siegling, Alexander B.; Furnham, Adrian; Petrides, K. V.

    2015-01-01

    This study investigated if the linkages between trait emotional intelligence (trait EI) and the Five-Factor Model of personality were invariant between men and women. Five English-speaking samples (N = 307-685) of mostly undergraduate students each completed a different measure of the Big Five personality traits and either the full form or short form of the Trait Emotional Intelligence Questionnaire (TEIQue). Across samples, models predicting global TEIQue scores from the Big Five were invari...

  6. Accessory genes confer a high replication rate to virulent feline immunodeficiency virus.

    Science.gov (United States)

    Troyer, Ryan M; Thompson, Jesse; Elder, John H; VandeWoude, Sue

    2013-07-01

    Feline immunodeficiency virus (FIV) is a lentivirus that causes AIDS in domestic cats, similar to human immunodeficiency virus (HIV)/AIDS in humans. The FIV accessory protein Vif abrogates the inhibition of infection by cat APOBEC3 restriction factors. FIV also encodes a multifunctional OrfA accessory protein that has characteristics similar to HIV Tat, Vpu, Vpr, and Nef. To examine the role of vif and orfA accessory genes in FIV replication and pathogenicity, we generated chimeras between two FIV molecular clones with divergent disease potentials: a highly pathogenic isolate that replicates rapidly in vitro and is associated with significant immunopathology in vivo, FIV-C36 (referred to here as high-virulence FIV [HV-FIV]), and a less-pathogenic strain, FIV-PPR (referred to here as low-virulence FIV [LV-FIV]). Using PCR-driven overlap extension, we produced viruses in which vif, orfA, or both genes from virulent HV-FIV replaced equivalent genes in LV-FIV. The generation of these chimeras is more straightforward in FIV than in primate lentiviruses, since FIV accessory gene open reading frames have very little overlap with other genes. All three chimeric viruses exhibited increased replication kinetics in vitro compared to the replication kinetics of LV-FIV. Chimeras containing HV-Vif or Vif/OrfA had replication rates equivalent to those of the virulent HV-FIV parental virus. Furthermore, small interfering RNA knockdown of feline APOBEC3 genes resulted in equalization of replication rates between LV-FIV and LV-FIV encoding HV-FIV Vif. These findings demonstrate that Vif-APOBEC interactions play a key role in controlling the replication and pathogenicity of this immunodeficiency-inducing virus in its native host species and that accessory genes act as mediators of lentiviral strain-specific virulence.

  7. Antibiotic resistance profile and virulence genes of uropathogenic Escherichia coli isolates in relation to phylogeny.

    Science.gov (United States)

    Adib, N; Ghanbarpour, R; Solatzadeh, H; Alizade, H

    2014-03-01

    Escherichia coli (E. coli) strains are the major cause of urinary tract infections (UTI) and belong to the large group of extra-intestinal pathogenic E. coli. The purposes of this study were to determine the antibiotic resistance profile, virulence genes and phylogenetic background of E. coli isolates from UTI cases. A total of 137 E. coli isolates were obtained from UTI samples. The antimicrobial susceptibility of confirmed isolates was determined by disk diffusion method against eight antibiotics. The isolates were examined to determine the presence and prevalence of selected virulence genes including iucD, sfa/focDE, papEF and hly. ECOR phylo-groups of isolates were determined by detection of yjaA and chuA genes and fragment TspE4.C2. The antibiogram results showed that 71% of the isolates were resistant to cefazolin, 60.42% to co-trimoxazole, 54.16% to nalidixic acid, 36.45% to gentamicin, 29.18% to ciprofloxacin, 14.58% to cefepime, 6.25% to nitrofurantoin and 0.00% to imipenem. Twenty-two antibiotic resistance patterns were observed among the isolates. Virulence genotyping of isolates revealed that 58.39% isolates had at least one of the four virulence genes. The iucD gene was the most prevalent gene (43.06%). The other genes including sfa/focDE, papEF and hly genes were detected in 35.76%, 18.97% and 2.18% isolates, respectively. Nine combination patterns of the virulence genes were detected in isolates. Phylotyping of 137 isolates revealed that the isolates fell into A (45.99%), B1 (13.14%), B2 (19.71%) and D (21.16%) groups. Phylotyping of multidrug resistant isolates indicated that these isolates are mostly in A (60.34%) and D (20.38%) groups. In conclusion, the isolates that possessed the iucD, sfa/focDE, papEF and hly virulence genes mostly belonged to A and B2 groups, whereas antibiotic resistant isolates were in groups A and D. Escherichia coli strains carrying virulence factors and antibiotic resistance are distributed in specific phylogenetic

  8. Analysis of multilocus sequence typing and virulence characterization of Listeria monocytogenes isolates from Chinese retail ready-to-eat food

    Directory of Open Access Journals (Sweden)

    Shi eWu

    2016-02-01

    Full Text Available Eighty Listeria monocytogenes isolates were obtained from Chinese retail ready-to-eat (RTE food and were previously characterized with serotyping and antibiotic susceptibility tests. The aim of this study was to characterize the subtype and virulence potential of these L. monocytogenes isolates by multilocus sequence typing (MLST, virulence-associate genes, epidemic clones (ECs and sequence analysis of the important virulence factor: internalin A (inlA. The result of MLST revealed that these L. monocytogenes isolates belonged to 14 different sequence types (STs. With the exception of four new STs (ST804, ST805, ST806 and ST807, all other STs observed in this study have been associated with human listeriosis and outbreaks to varying extents. Six virulence-associate genes (inlA, inlB, inlC, inlJ, hly and llsX were selected and their presence was investigated using PCR. All strains carried inlA, inlB, inlC, inlJ, and hly, whereas 38.8% (31/80 of strains harbored the listeriolysin S genes (llsX. A multiplex PCR assay was used to evaluate the presence of markers specific to epidemic clones of L. monocytogenes and identified 26.3% (21/80 of ECI in the 4b-4d-4e strains. Further study of inlA sequencing revealed that most strains contained the full-length InlA required for host cell invasion, whereas three mutations lead to premature stop codons (PMSC within a novel PMSCs at position 326 (GAA→TAA. MLST and inlA sequence analysis results were concordant, and different virulence potentials within isolates were observed. These findings suggest that L. monocytogenes isolates from RTE food in China could be virulent and be capable of causing human illness. Furthermore, the STs and virulence profiles of L. monocytogenes isolates have significant implications for epidemiological and public health studies of this pathogen.

  9. Analysis of Multilocus Sequence Typing and Virulence Characterization of Listeria monocytogenes Isolates from Chinese Retail Ready-to-Eat Food.

    Science.gov (United States)

    Wu, Shi; Wu, Qingping; Zhang, Jumei; Chen, Moutong; Guo, Weipeng

    2016-01-01

    Eighty Listeria monocytogenes isolates were obtained from Chinese retail ready-to-eat (RTE) food and were previously characterized with serotyping and antibiotic susceptibility tests. The aim of this study was to characterize the subtype and virulence potential of these L. monocytogenes isolates by multilocus sequence typing (MLST), virulence-associate genes, epidemic clones (ECs), and sequence analysis of the important virulence factor: internalin A (inlA). The result of MLST revealed that these L. monocytogenes isolates belonged to 14 different sequence types (STs). With the exception of four new STs (ST804, ST805, ST806, and ST807), all other STs observed in this study have been associated with human listeriosis and outbreaks to varying extents. Six virulence-associate genes (inlA, inlB, inlC, inlJ, hly, and llsX) were selected and their presence was investigated using PCR. All strains carried inlA, inlB, inlC, inlJ, and hly, whereas 38.8% (31/80) of strains harbored the listeriolysin S genes (llsX). A multiplex PCR assay was used to evaluate the presence of markers specific to epidemic clones of L. monocytogenes and identified 26.3% (21/80) of ECI in the 4b-4d-4e strains. Further study of inlA sequencing revealed that most strains contained the full-length InlA required for host cell invasion, whereas three mutations lead to premature stop codons (PMSC) within a novel PMSCs at position 326 (GAA → TAA). MLST and inlA sequence analysis results were concordant, and different virulence potentials within isolates were observed. These findings suggest that L. monocytogenes isolates from RTE food in China could be virulent and be capable of causing human illness. Furthermore, the STs and virulence profiles of L. monocytogenes isolates have significant implications for epidemiological and public health studies of this pathogen.

  10. Molecular investigation of virulence factors of Brucella melitensis and Brucella abortus strains isolated from clinical and non-clinical samples.

    Science.gov (United States)

    Mirnejad, Reza; Jazi, Faramarz Masjedian; Mostafaei, Shayan; Sedighi, Mansour

    2017-08-01

    Brucella is zoonotic pathogen that induces abortion and sterility in domestic mammals and chronic infections in humans called Malta fever. It is a facultative intracellular potential pathogen with high infectivity. The virulence of Brucella is dependent upon its potential virulence factors such as enzymes and cell envelope associated virulence genes. The aim of this study was to investigate the Brucella virulence factors among strains isolated from humans and animals in different parts of Iran. Seventy eight strains of Brucella species isolated from suspected human and animal cases from several provinces of Iran during 2015-2016 and identified by phenotypic and molecular methods. The multiplex-PCR (M-PCR) assay was performed in order to detect the ure, wbkA, omp19, mviN, manA and perA genes by using gene specific primers. Out of 78 isolates of Brucella spp., 57 (73%) and 21 (27%) isolates were detected as B. melitensis and B. abortus, respectively, by molecular method. The relative frequency of virulence genes ure, wbkA, omp19, mviN, manA and perA were 74.4%, 89.7%, 93.6%, 94.9%, 100% and 92.3%, respectively. Our results indicate that the most of Brucella strains isolated from this region possess high percent of virulence factor genes (ure, wbkA, omp19, mviN, manA and perA) in their genome. So, each step of infection can be mediated by a number of virulence factors and each strain may have a unique combination of these factors that affected the rate of bacterial pathogenesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Genome-wide mapping of virulence in brown planthopper identifies loci that break down host plant resistance.

    Science.gov (United States)

    Jing, Shengli; Zhang, Lei; Ma, Yinhua; Liu, Bingfang; Zhao, Yan; Yu, Hangjin; Zhou, Xi; Qin, Rui; Zhu, Lili; He, Guangcun

    2014-01-01

    Insects and plants have coexisted for over 350 million years and their interactions have affected ecosystems and agricultural practices worldwide. Variation in herbivorous insects' virulence to circumvent host resistance has been extensively documented. However, despite decades of investigation, the genetic foundations of virulence are currently unknown. The brown planthopper (Nilaparvata lugens) is the most destructive rice (Oryza sativa) pest in the world. The identification of the resistance gene Bph1 and its introduction in commercial rice varieties prompted the emergence of a new virulent brown planthopper biotype that was able to break the resistance conferred by Bph1. In this study, we aimed to construct a high density linkage map for the brown planthopper and identify the loci responsible for its virulence in order to determine their genetic architecture. Based on genotyping data for hundreds of molecular markers in three mapping populations, we constructed the most comprehensive linkage map available for this species, covering 96.6% of its genome. Fifteen chromosomes were anchored with 124 gene-specific markers. Using genome-wide scanning and interval mapping, the Qhp7 locus that governs preference for Bph1 plants was mapped to a 0.1 cM region of chromosome 7. In addition, two major QTLs that govern the rate of insect growth on resistant rice plants were identified on chromosomes 5 (Qgr5) and 14 (Qgr14). This is the first study to successfully locate virulence in the genome of this important agricultural insect by marker-based genetic mapping. Our results show that the virulence which overcomes the resistance conferred by Bph1 is controlled by a few major genes and that the components of virulence originate from independent genetic characters. The isolation of these loci will enable the elucidation of the molecular mechanisms underpinning the rice-brown planthopper interaction and facilitate the development of durable approaches for controlling this most

  12. Genome-wide mapping of virulence in brown planthopper identifies loci that break down host plant resistance.

    Directory of Open Access Journals (Sweden)

    Shengli Jing

    Full Text Available Insects and plants have coexisted for over 350 million years and their interactions have affected ecosystems and agricultural practices worldwide. Variation in herbivorous insects' virulence to circumvent host resistance has been extensively documented. However, despite decades of investigation, the genetic foundations of virulence are currently unknown. The brown planthopper (Nilaparvata lugens is the most destructive rice (Oryza sativa pest in the world. The identification of the resistance gene Bph1 and its introduction in commercial rice varieties prompted the emergence of a new virulent brown planthopper biotype that was able to break the resistance conferred by Bph1. In this study, we aimed to construct a high density linkage map for the brown planthopper and identify the loci responsible for its virulence in order to determine their genetic architecture. Based on genotyping data for hundreds of molecular markers in three mapping populations, we constructed the most comprehensive linkage map available for this species, covering 96.6% of its genome. Fifteen chromosomes were anchored with 124 gene-specific markers. Using genome-wide scanning and interval mapping, the Qhp7 locus that governs preference for Bph1 plants was mapped to a 0.1 cM region of chromosome 7. In addition, two major QTLs that govern the rate of insect growth on resistant rice plants were identified on chromosomes 5 (Qgr5 and 14 (Qgr14. This is the first study to successfully locate virulence in the genome of this important agricultural insect by marker-based genetic mapping. Our results show that the virulence which overcomes the resistance conferred by Bph1 is controlled by a few major genes and that the components of virulence originate from independent genetic characters. The isolation of these loci will enable the elucidation of the molecular mechanisms underpinning the rice-brown planthopper interaction and facilitate the development of durable approaches for

  13. Virulent PB1-F2 residues: effects on fitness of H1N1 influenza A virus in mice and changes during evolution of human influenza A viruses.

    Science.gov (United States)

    Alymova, Irina V; McCullers, Jonathan A; Kamal, Ram P; Vogel, Peter; Green, Amanda M; Gansebom, Shane; York, Ian A

    2018-05-10

    Specific residues of influenza A virus (IAV) PB1-F2 proteins may enhance inflammation or cytotoxicity. In a series of studies, we evaluated the function of these virulence-associated residues in the context of different IAV subtypes in mice. Here, we demonstrate that, as with the previously assessed pandemic 1968 (H3N2) IAV, PB1-F2 inflammatory residues increase the virulence of H1N1 IAV, suggesting that this effect might be a universal feature. Combining both inflammatory and cytotoxic residues in PB1-F2 enhanced virulence further, compared to either motif alone. Residues from these virulent motifs have been present in natural isolates from human seasonal IAV of all subtypes, but there has been a trend toward a gradual reduction in the number of virulent residues over time. However, human IAV of swine and avian origin tend to have more virulent residues than do the human-adapted seasonal strains, raising the possibility that donation of PB1 segments from these zoonotic viruses may increase the severity of some seasonal human strains. Our data suggest the value of surveillance of virulent residues in both human and animal IAV to predict the severity of influenza season.

  14. The Trait Lady Speaks Up

    Science.gov (United States)

    Culham, Ruth

    2006-01-01

    The acknowledged expert on the 6+1 traits of writing explains what the traits are and what they are not: The traits are not a curriculum; they are part and parcel of the writing process; they are a model, not a program; they are not a prepackaged replacement for teaching writing; and they are the language of the writing workshop. The author…

  15. Evaluating Callous-Unemotional Traits as a Personality Construct.

    Science.gov (United States)

    Frick, Paul J; Ray, James V

    2015-12-01

    We evaluate the importance of callous-unemotional (CU) traits as a personality construct in isolation from other facets of psychopathy. Specifically, we review research suggesting that these traits are useful for designating a subgroup of youth with serious conduct problems who differ from other antisocial youth on important biological, emotional, cognitive, and social characteristics. In addition, the temperamental features related to CU traits are risk factors for impairments in conscience development in young children. Thus, these traits could advance theoretical models explaining the development of severe antisocial behavior and psychopathy. CU traits also have important clinical utility because they designate a particularly severe and impaired subgroup of antisocial youth, leading to their inclusion in the DSM-5. As a result of this inclusion in diagnostic classification, there has been an increased focus on how to best assess CU traits, and we discuss several key issues in their assessment, highlighting several limitations in existing measures. Finally, the increased use of CU traits, separately from other facets of psychopathy, makes it important to determine how these traits relate to other personality constructs. Thus, we examine how measures of CU traits relate to the broader construct of psychopathy and to other basic personality dimensions. © 2014 Wiley Periodicals, Inc.

  16. Neurological soft signs in Chinese adolescents with antisocial personality traits.

    Science.gov (United States)

    Wang, Xin; Cai, Lin; Li, Lingyan; Yang, Yanjie; Yao, Shuqiao; Zhu, Xiongzhao

    2016-09-30

    The current study was designed to explore the specific relationship between neurologic soft signs (NSSs) and characteristics of antisocial personality traits in adolescents, and to investigate particular NSSs linked to certain brain regions in adolescents with antisocial personality traits. The research was conducted on 96 adolescents diagnosed with ASP traits (ASP trait group) using the ASPD subscale of the Personality Diagnostic Questionnaire for the DSM-IV (PDQ-4+) and 96 adolescents without traits of any personality disorder (control group). NSSs were assessed using the soft sign subscales of the Cambridge Neurological Inventory. Adolescents with ASP traits showed more motor coordination, sensory integration, disinhibition, and total NSSs than the control group. Seven NSSs, including stereognosia in right hand, finger agnosia and graphesthesia in both hands, left-right orientation, and go/no go stimulus, were significantly more frequent in teenagers with ASP traits. Sensory integration was positively associated with ASP traits. Adolescents with antisocial personality traits might have abnormalities in the central nervous system, and sensory integration might be the particular indicator of antisocial personality disorder. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Expression of virulence factors by Staphylococcus aureus grown in serum.

    Science.gov (United States)

    Oogai, Yuichi; Matsuo, Miki; Hashimoto, Masahito; Kato, Fuminori; Sugai, Motoyuki; Komatsuzawa, Hitoshi

    2011-11-01

    Staphylococcus aureus produces many virulence factors, including toxins, immune-modulatory factors, and exoenzymes. Previous studies involving the analysis of virulence expression were mainly performed by in vitro experiments using bacterial medium. However, when S. aureus infects a host, the bacterial growth conditions are quite different from those in a medium, which may be related to the different expression of virulence factors in the host. In this study, we investigated the expression of virulence factors in S. aureus grown in calf serum. The expression of many virulence factors, including hemolysins, enterotoxins, proteases, and iron acquisition factors, was significantly increased compared with that in bacterial medium. In addition, the expression of RNA III, a global regulon for virulence expression, was significantly increased. This effect was partially restored by the addition of 300 μM FeCl₃ into serum, suggesting that iron depletion is associated with the increased expression of virulence factors in serum. In chemically defined medium without iron, a similar effect was observed. In a mutant with agr inactivated grown in serum, the expression of RNA III, psm, and sec4 was not increased, while other factors were still induced in the mutant, suggesting that another regulatory factor(s) is involved. In addition, we found that serum albumin is a major factor for the capture of free iron to prevent the supply of iron to bacteria grown in serum. These results indicate that S. aureus expresses virulence factors in adaptation to the host environment.

  18. Detection of virulence-associated genes in Brucella melitensis ...

    African Journals Online (AJOL)

    Ibrahim Eldaghayes

    2018-03-20

    Mar 20, 2018 ... isolated from goats. This discrepancies may indicate that B. melitensis field strains prevailing in Egypt are more virulent than the strains of B. melitensis isolated from caprines in Iran. As, it was emphasized that the. T4SS of Brucella encoded by the virB operon is a major virulence factor (Delrue et al., 2005).

  19. Limiting opportunities for cheating stabilizes virulence in insect parasitic nematodes

    Science.gov (United States)

    Cooperative secretion of virulence factors by pathogens can often lead to social conflict as cheating mutants that benefit from collective action, but do not contribute to it, can arise and locally outcompete cooperators within hosts, leading to loss of virulence. There is a wide range of in vivo st...

  20. Antibiotic Resistance and Virulence Properties in Escherichia coli ...

    African Journals Online (AJOL)

    This study determined E. coli resistance to commonly used antibiotics together with their virulence properties in Ile-Ife, Nigeria. A total of 137 E. coli isolates from cases of urinary tract infection were tested for their sensitivity to commonly used antibiotics and possession of virulence factors using standard methods.

  1. Nitrogen Metabolite Repression of Metabolism and Virulence in the Human Fungal Pathogen Cryptococcus neoformans

    Science.gov (United States)

    Lee, I. Russel; Chow, Eve W. L.; Morrow, Carl A.; Djordjevic, Julianne T.; Fraser, James A.

    2011-01-01

    Proper regulation of metabolism is essential to maximizing fitness of organisms in their chosen environmental niche. Nitrogen metabolite repression is an example of a regulatory mechanism in fungi that enables preferential utilization of easily assimilated nitrogen sources, such as ammonium, to conserve resources. Here we provide genetic, transcriptional, and phenotypic evidence of nitrogen metabolite repression in the human pathogen Cryptococcus neoformans. In addition to loss of transcriptional activation of catabolic enzyme-encoding genes of the uric acid and proline assimilation pathways in the presence of ammonium, nitrogen metabolite repression also regulates the production of the virulence determinants capsule and melanin. Since GATA transcription factors are known to play a key role in nitrogen metabolite repression, bioinformatic analyses of the C. neoformans genome were undertaken and seven predicted GATA-type genes were identified. A screen of these deletion mutants revealed GAT1, encoding the only global transcription factor essential for utilization of a wide range of nitrogen sources, including uric acid, urea, and creatinine—three predominant nitrogen constituents found in the C. neoformans ecological niche. In addition to its evolutionarily conserved role in mediating nitrogen metabolite repression and controlling the expression of catabolic enzyme and permease-encoding genes, Gat1 also negatively regulates virulence traits, including infectious basidiospore production, melanin formation, and growth at high body temperature (39°–40°). Conversely, Gat1 positively regulates capsule production. A murine inhalation model of cryptococcosis revealed that the gat1Δ mutant is slightly more virulent than wild type, indicating that Gat1 plays a complex regulatory role during infection. PMID:21441208

  2. Virulence on the fly: Drosophila melanogaster as a model genetic organism to decipher host-pathogen interactions.

    NARCIS (Netherlands)

    Limmer, S.; Quintin, J.; Hetru, C.; Ferrandon, D.

    2011-01-01

    To gain an in-depth grasp of infectious processes one has to know the specific interactions between the virulence factors of the pathogen and the host defense mechanisms. A thorough understanding is crucial for identifying potential new drug targets and designing drugs against which the pathogens

  3. Carbon nanoparticles in lateral flow methods to detect genes encoding virulence factors of Shiga toxin-producing Escherichia coli

    NARCIS (Netherlands)

    Noguera, P.; Posthuma-Trumpie, G.A.; Tuil, van M.; Wal, van der F.J.; Boer, de A.; Moers, A.P.H.A.; Amerongen, van A.

    2011-01-01

    The use of carbon nanoparticles is shown for the detection and identification of different Shiga toxin-producing Escherichia coli virulence factors (vt1, vt2, eae and ehxA) and a 16S control (specific for E. coli) based on the use of lateral flow strips (nucleic acid lateral flow immunoassay,

  4. Elements in the canine distemper virus M 3' UTR contribute to control of replication efficiency and virulence.

    Directory of Open Access Journals (Sweden)

    Danielle E Anderson

    Full Text Available Canine distemper virus (CDV is a negative-sense, single-stranded RNA virus within the genus Morbillivirus and the family Paramyxoviridae. The Morbillivirus genome is composed of six transcriptional units that are separated by untranslated regions (UTRs, which are relatively uniform in length, with the exception of the UTR between the matrix (M and fusion (F genes. This UTR is at least three times longer and in the case of CDV also highly variable. Exchange of the M-F region between different CDV strains did not affect virulence or disease phenotype, demonstrating that this region is functionally interchangeable. Viruses carrying the deletions in the M 3' UTR replicated more efficiently, which correlated with a reduction of virulence, suggesting that overall length as well as specific sequence motifs distributed throughout the region contribute to virulence.

  5. Analysis of variation in virulence of Beauveria bassiana against insect pests of pigeonpea using qPCR.

    Science.gov (United States)

    Senthilraja, Govindasamy; Anand, Theerthagiri; Mohankumar, Subbarayalu; Raguchander, Thiruvengadam; Samiyappan, Ramasamy

    2018-03-01

    Beauveria bassiana is a broad spectrum microbial bioagent used for the control of agriculturally important insect pests. However, in our experiments, two virulent isolates of B. bassiana (B2 and B10) showed specific preference toward Maruca vitrata and Helicoverpa armigera of pigeonpea. To better understand this feature, we developed a qPCR assay to quantify the chitinase (virulence factor) of B. bassiana during the infection process. Isolates of B. bassiana were grown on insect cuticle amended medium and minimal medium (without insect cuticle) to assess the induction of chitinase. Our results revealed a positive correlation between expression of chitinase by B. bassiana and the substrates (with or without cuticles of M. vitrata and H. armigera) used. This study showcases the methodology to quantify the chitinase and analysis of variation in virulence of B. bassiana (B2 and B10) against M. vitrata and H. armigera. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. The Central Metabolism Regulator EIIAGlc Switches Salmonella from Growth Arrest to Acute Virulence through Activation of Virulence Factor Secretion

    Directory of Open Access Journals (Sweden)

    Alain Mazé

    2014-06-01

    Full Text Available The ability of Salmonella to cause disease depends on metabolic activities and virulence factors. Here, we show that a key metabolic protein, EIIAGlc, is absolutely essential for acute infection, but not for Salmonella survival, in a mouse typhoid fever model. Surprisingly, phosphorylation-dependent EIIAGlc functions, including carbohydrate transport and activation of adenylate cyclase for global regulation, do not explain this virulence phenotype. Instead, biochemical studies, in vitro secretion and translocation assays, and in vivo genetic epistasis experiments suggest that EIIAGlc binds to the type three secretion system 2 (TTSS-2 involved in systemic virulence, stabilizes its cytoplasmic part including the crucial TTSS-2 ATPase, and activates virulence factor secretion. This unexpected role of EIIAGlc reveals a striking direct link between central Salmonella metabolism and a crucial virulence mechanism.

  7. Role of cyclic di-GMP in Xylella fastidiosa biofilm formation, plant virulence, and insect transmission.

    Science.gov (United States)

    Chatterjee, Subhadeep; Killiny, Nabil; Almeida, Rodrigo P P; Lindow, Steven E

    2010-10-01

    Xylella fastidiosa must coordinately regulate a variety of traits contributing to biofilm formation, host plant and vector colonization, and transmission between plants. Traits such as production of extracellular polysaccharides (EPS), adhesins, extracellular enzymes, and pili are expressed in a cell-density-dependent fashion mediated by a cell-to-cell signaling system involving a fatty acid diffusible signaling factor (DSF). The expression of gene PD0279 (which has a GGDEF domain) is downregulated in the presence of DSF and may be involved in intracellular signaling by modulating the levels of cyclic di-GMP. PD0279, designated cyclic di-GMP synthase A (cgsA), is required for biofilm formation, plant virulence, and vector transmission. cgsA mutants exhibited a hyperadhesive phenotype in vitro and overexpressed gumJ, hxfA, hxfB, xadA, and fimA, which promote attachment of cells to surfaces and, hence, biofilm formation. The mutants were greatly reduced in virulence to grape albeit still transmissible by insect vectors, although at a reduced level compared with transmission rates of the wild-type strain, despite the fact that similar numbers of cells of the cgsA mutant were acquired by the insects from infected plants. High levels of EPS were measured in cgsA mutants compared with wild-type strains, and scanning electron microscopy analysis also revealed a thicker amorphous layer surrounding the mutants. Overexpression of cgsA in a cgsA-complemented mutant conferred the opposite phenotypes in vitro. These results suggest that decreases of cyclic di-GMP result from the accumulation of DSF as cell density increases, leading to a phenotypic transition from a planktonic state capable of colonizing host plants to an adhesive state that is insect transmissible.

  8. Relationship between oviposition, virulence gene expression and parasitism success in Cotesia typhae nov. sp. parasitoid strains.

    Science.gov (United States)

    Benoist, R; Chantre, C; Capdevielle-Dulac, C; Bodet, M; Mougel, F; Calatayud, P A; Dupas, S; Huguet, E; Jeannette, R; Obonyo, J; Odorico, C; Silvain, J F; Le Ru, B; Kaiser, L

    2017-12-01

    Studying mechanisms that drive host adaptation in parasitoids is crucial for the efficient use of parasitoids in biocontrol programs. Cotesia typhae nov. sp. (Fernández-Triana) (Hymenoptera: Braconidae) is a newly described parasitoid of the Mediterranean corn borer Sesamia nonagrioides (Lefebvre) (Lepidoptera: Noctuidae). Braconidae are known for their domesticated bracovirus, which is injected with eggs in the host larva to overcome its resistance. In this context, we compared reproductive success traits of four Kenyan strains of C. typhae on a French and a Kenyan populations of its host. Differences were found between the four strains and the two most contrasted ones were studied more thoroughly on the French host population. Parasitoid offspring size was correlated with parasitism success and the expression of bracovirus virulence genes (CrV1 and Cystatin) in the host larva after parasitism. Hybrids between these two parasitoid strains showed phenotype and gene expression profiles similar to the most successful parental strain, suggesting the involvement of dominant alleles in the reproductive traits. Ovary dissections revealed that the most successful strain injected more eggs in a single host larva than the less successful one, despite an equal initial ovocyte number in ovaries. It can be expected that the amount of viral particles increase with the number of eggs injected. The ability to bypass the resistance of the allopatric host may in consequence be related to the oviposition behaviour (eggs allocation). The influence of the number of injected eggs on parasitism success and on virulence gene expression was evaluated by oviposition interruption experiments.

  9. Trait sexual motivation questionnaire: concept and validation.

    Science.gov (United States)

    Stark, Rudolf; Kagerer, Sabine; Walter, Bertram; Vaitl, Dieter; Klucken, Tim; Wehrum-Osinsky, Sina

    2015-04-01

    Trait sexual motivation defines a psychological construct that reflects the long-lasting degree of motivation for sexual activities, which is assumed to be the result of biological and sociocultural influences. With this definition, it shares commonalities with other sexuality-related constructs like sexual desire, sexual drive, sexual needs, and sexual compulsivity. The Trait Sexual Motivation Questionnaire (TSMQ) was developed in order to measure trait sexual motivation with its different facets. Several steps were conducted: First, items were composed assessing sexual desire, the effort made to gain sex, as well as specific sexual behaviors. Factor analysis of the data of a first sample (n = 256) was conducted. Second, the factor solution was verified by a confirmatory factor analysis in a second sample (n = 498) and construct validity was demonstrated. Third, the temporal stability of the TSMQ was tested in a third study (n = 59). Questionnaire data. The exploratory and confirmatory factor analyses revealed that trait sexual motivation is best characterized by four subscales: Solitary Sexuality, Importance of Sex, Seeking Sexual Encounters, and Comparison with Others. It could be shown that the test quality of the questionnaire is high. Most importantly for the trait concept, the retest reliability after 1 year was r = 0.87. Our results indicate that the TSMQ is indeed a suitable tool for measuring long-lasting sexual motivation with high test quality and high construct validity. A future differentiation between trait and state sexual motivation might be helpful for clinical as well as forensic research. © 2015 International Society for Sexual Medicine.

  10. Computational prediction of the Crc regulon identifies genus-wide and species-specific targets of catabolite repression control in Pseudomonas bacteria

    Directory of Open Access Journals (Sweden)

    O'Gara Fergal

    2010-11-01

    Full Text Available Abstract Background Catabolite repression control (CRC is an important global control system in Pseudomonas that fine tunes metabolism in order optimise growth and metabolism in a range of different environments. The mechanism of CRC in Pseudomonas spp. centres on the binding of a protein, Crc, to an A-rich motif on the 5' end of an mRNA resulting in translational down-regulation of target genes. Despite the identification of several Crc targets in Pseudomonas spp. the Crc regulon has remained largely unexplored. Results In order to predict direct targets of Crc, we used a bioinformatics approach based on detection of A-rich motifs near the initiation of translation of all protein-encoding genes in twelve fully sequenced Pseudomonas genomes. As expected, our data predict that genes related to the utilisation of less preferred nutrients, such as some carbohydrates, nitrogen sources and aromatic carbon compounds are targets of Crc. A general trend in this analysis is that the regulation of transporters is conserved across species whereas regulation of specific enzymatic steps or transcriptional activators are often conserved only within a species. Interestingly, some nucleoid associated proteins (NAPs such as HU and IHF are predicted to be regulated by Crc. This finding indicates a possible role of Crc in indirect control over a subset of genes that depend on the DNA bending properties of NAPs for expression or repression. Finally, some virulence traits such as alginate and rhamnolipid production also appear to be regulated by Crc, which links nutritional status cues with the regulation of virulence traits. Conclusions Catabolite repression control regulates a broad spectrum of genes in Pseudomonas. Some targets are genus-wide and are typically related to central metabolism, whereas other targets are species-specific, or even unique to particular strains. Further study of these novel targets will enhance our understanding of how Pseudomonas

  11. Computational prediction of the Crc regulon identifies genus-wide and species-specific targets of catabolite repression control in Pseudomonas bacteria.

    Science.gov (United States)

    Browne, Patrick; Barret, Matthieu; O'Gara, Fergal; Morrissey, John P

    2010-11-25

    Catabolite repression control (CRC) is an important global control system in Pseudomonas that fine tunes metabolism in order optimise growth and metabolism in a range of different environments. The mechanism of CRC in Pseudomonas spp. centres on the binding of a protein, Crc, to an A-rich motif on the 5' end of an mRNA resulting in translational down-regulation of target genes. Despite the identification of several Crc targets in Pseudomonas spp. the Crc regulon has remained largely unexplored. In order to predict direct targets of Crc, we used a bioinformatics approach based on detection of A-rich motifs near the initiation of translation of all protein-encoding genes in twelve fully sequenced Pseudomonas genomes. As expected, our data predict that genes related to the utilisation of less preferred nutrients, such as some carbohydrates, nitrogen sources and aromatic carbon compounds are targets of Crc. A general trend in this analysis is that the regulation of transporters is conserved across species whereas regulation of specific enzymatic steps or transcriptional activators are often conserved only within a species. Interestingly, some nucleoid associated proteins (NAPs) such as HU and IHF are predicted to be regulated by Crc. This finding indicates a possible role of Crc in indirect control over a subset of genes that depend on the DNA bending properties of NAPs for expression or repression. Finally, some virulence traits such as alginate and rhamnolipid production also appear to be regulated by Crc, which links nutritional status cues with the regulation of virulence traits. Catabolite repression control regulates a broad spectrum of genes in Pseudomonas. Some targets are genus-wide and are typically related to central metabolism, whereas other targets are species-specific, or even unique to particular strains. Further study of these novel targets will enhance our understanding of how Pseudomonas bacteria integrate nutritional status cues with the regulation

  12. Computational prediction of the Crc regulon identifies genus-wide and species-specific targets of catabolite repression control in Pseudomonas bacteria

    LENUS (Irish Health Repository)

    Browne, Patrick

    2010-11-25

    Abstract Background Catabolite repression control (CRC) is an important global control system in Pseudomonas that fine tunes metabolism in order optimise growth and metabolism in a range of different environments. The mechanism of CRC in Pseudomonas spp. centres on the binding of a protein, Crc, to an A-rich motif on the 5\\' end of an mRNA resulting in translational down-regulation of target genes. Despite the identification of several Crc targets in Pseudomonas spp. the Crc regulon has remained largely unexplored. Results In order to predict direct targets of Crc, we used a bioinformatics approach based on detection of A-rich motifs near the initiation of translation of all protein-encoding genes in twelve fully sequenced Pseudomonas genomes. As expected, our data predict that genes related to the utilisation of less preferred nutrients, such as some carbohydrates, nitrogen sources and aromatic carbon compounds are targets of Crc. A general trend in this analysis is that the regulation of transporters is conserved across species whereas regulation of specific enzymatic steps or transcriptional activators are often conserved only within a species. Interestingly, some nucleoid associated proteins (NAPs) such as HU and IHF are predicted to be regulated by Crc. This finding indicates a possible role of Crc in indirect control over a subset of genes that depend on the DNA bending properties of NAPs for expression or repression. Finally, some virulence traits such as alginate and rhamnolipid production also appear to be regulated by Crc, which links nutritional status cues with the regulation of virulence traits. Conclusions Catabolite repression control regulates a broad spectrum of genes in Pseudomonas. Some targets are genus-wide and are typically related to central metabolism, whereas other targets are species-specific, or even unique to particular strains. Further study of these novel targets will enhance our understanding of how Pseudomonas bacteria integrate

  13. DSM-5 Personality Traits and DSM-IV Personality Disorders

    Science.gov (United States)

    Hopwood, Christopher J.; Thomas, Katherine M.; Markon, Kristian E.; Wright, Aidan G.C.; Krueger, Robert F.

    2014-01-01

    Two issues pertinent to the DSM-5 proposal for personality pathology, the recovery of DSM-IV personality disorders (PDs) by proposed DSM-5 traits and the validity of the proposed DSM-5 hybrid model which incorporates both personality pathology symptoms and maladaptive traits, were evaluated in a large undergraduate sample (N = 808). Proposed DSM-5 traits as assessed with the Personality Inventory for DSM-5 explained a substantial proportion of variance in DSM-IV PDs as assessed with the Personality Diagnostic Questionnaire-4+, and trait indicators of the six proposed DSM-5 PDs were mostly specific to those disorders with some exceptions. Regression analyses support the DSM-5 hybrid model in that pathological traits and an indicator of general personality pathology severity provided incremental information about PDs. Findings are discussed in the context of broader issues around the proposed DSM-5 model of personality disorders. PMID:22250660

  14. Coregulation of host-adapted metabolism and virulence by pathogenic yersiniae

    Directory of Open Access Journals (Sweden)

    Ann Kathrin eHeroven

    2014-10-01

    Full Text Available Deciphering the principles how pathogenic bacteria adapt their metabolism to a specific host microenvironment is critical for understanding bacterial pathogenesis. The enteric pathogenic Yersinia species Y. pseudotuberculosis and Y. enterocolitica and the causative agent of plague, Y. pestis, are able to survive in a large variety of environmental reservoirs (e.g. soil, plants, insects as well as warm-blooded animals (e.g. rodents, pigs, humans with a particular preference for lymphatic tissues. In order to manage rapidly changing environmental conditions and inter-bacterial competition, Yersinia senses the nutritional composition during the course of an infection by special molecular devices, integrates this information and adapts its metabolism accordingly. In addition, nutrient availability has an impact on expression of virulence genes in response to C-sources, demonstrating a tight link between the pathogenicity of yersiniae and utilization of nutrients. Recent studies revealed that global regulatory factors such as the cAMP receptor protein (Crp and the carbon storage regulator (Csr system are part of a large network of transcriptional and posttranscriptional control strategies adjusting metabolic changes and virulence in response to temperature, ion and nutrient availability. Gained knowledge about the specific metabolic requirements and the correlation between metabolic and virulence gene expression that enable efficient host colonization led to the identification of new potential antimicrobial targets.

  15. Correlates of virulence in a frog-killing fungal pathogen: evidence from a California amphibian decline.

    Science.gov (United States)

    Piovia-Scott, Jonah; Pope, Karen; Worth, S Joy; Rosenblum, Erica Bree; Poorten, Thomas; Refsnider, Jeanine; Rollins-Smith, Louise A; Reinert, Laura K; Wells, Heather L; Rejmanek, Dan; Lawler, Sharon; Foley, Janet

    2015-07-01

    The fungal pathogen Batrachochytrium dendrobatidis (Bd) has caused declines and extinctions in amphibians worldwide, and there is increasing evidence that some strains of this pathogen are more virulent than others. While a number of putative virulence factors have been identified, few studies link these factors to specific epizootic events. We documented a dramatic decline in juvenile frogs in a Bd-infected population of Cascades frogs (Rana cascadae) in the mountains of northern California and used a laboratory experiment to show that Bd isolated in the midst of this decline induced higher mortality than Bd isolated from a more stable population of the same species of frog. This highly virulent Bd isolate was more toxic to immune cells and attained higher density in liquid culture than comparable isolates. Genomic analyses revealed that this isolate is nested within the global panzootic lineage and exhibited unusual genomic patterns, including increased copy numbers of many chromosomal segments. This study integrates data from multiple sources to suggest specific phenotypic and genomic characteristics of the pathogen that may be linked to disease-related declines.

  16. Coregulation of host-adapted metabolism and virulence by pathogenic yersiniae

    Science.gov (United States)

    Heroven, Ann Kathrin; Dersch, Petra

    2014-01-01

    Deciphering the principles how pathogenic bacteria adapt their metabolism to a specific host microenvironment is critical for understanding bacterial pathogenesis. The enteric pathogenic Yersinia species Yersinia pseudotuberculosis and Yersinia enterocolitica and the causative agent of plague, Yersinia pestis, are able to survive in a large variety of environmental reservoirs (e.g., soil, plants, insects) as well as warm-blooded animals (e.g., rodents, pigs, humans) with a particular preference for lymphatic tissues. In order to manage rapidly changing environmental conditions and interbacterial competition, Yersinia senses the nutritional composition during the course of an infection by special molecular devices, integrates this information and adapts its metabolism accordingly. In addition, nutrient availability has an impact on expression of virulence genes in response to C-sources, demonstrating a tight link between the pathogenicity of yersiniae and utilization of nutrients. Recent studies revealed that global regulatory factors such as the cAMP receptor protein (Crp) and the carbon storage regulator (Csr) system are part of a large network of transcriptional and posttranscriptional control strategies adjusting metabolic changes and virulence in response to temperature, ion and nutrient availability. Gained knowledge about the specific metabolic requirements and the correlation between metabolic and virulence gene expression that enable efficient host colonization led to the identification of new potential antimicrobial targets. PMID:25368845

  17. Staphylococcus aureus clonal dynamics and virulence factors in children with atopic dermatitis

    DEFF Research Database (Denmark)

    Lomholt, Hans Bredsted; Andersen, KE; Kilian, Mogens

    2005-01-01

    A prospective cohort study was undertaken to determine the clonal dynamics of Staphylococcus aureus colonization and infection during 1 y in children with atopic dermatitis, and to correlate specific clones, accessory gene regulator (agr) groups, and production of virulence factors with eczema......, toxins, and were assigned to agr groups. S. aureus colonization patterns ranged from rare colonization over transient colonization to persistent colonization by a single clone or a dynamic exchange of up to five clones. Production of no single virulence factor including superantigens and toxins...... activity. Eleven children were examined every 6 wk with swaps taken from active eczema, anterior nose, axillae and perineum, and scoring of eczema activity by severity scoring of atopic dermatitis (SCORAD). Individual S. aureus clonal types were identified and examined for production of superantigens...

  18. Differences in the stability of the plasmids of Yersinia pestis cultures in vitro: impact on virulence

    Directory of Open Access Journals (Sweden)

    TC Leal-Balbino

    2004-11-01

    Full Text Available Plasmid and chromosomal genes encode determinants of virulence for Yersinia pestis, the causative agent of plague. However, in vitro, Y. pestis genome is very plastic and several changes have been described. To evaluate the alterations in the plasmid content of the cultures in vitro and the impact of the alterations to their pathogenicity, three Y. pestis isolates were submitted to serial subculture, analysis of the plasmid content, and testing for the presence of characteristic genes in each plasmid of colonies selected after subculture. Different results were obtained with each strain. The plasmid content of one of them was shown to be stable; no apparent alteration was produced through 32 subcultures. In the other two strains, several alterations were observed. LD50 in mice of the parental strains and the derived cultures with different plasmid content were compared. No changes in the virulence plasmid content could be specifically correlated with changes in the LD50.

  19. Automated 5 ' nuclease assay for detection of virulence factors in porcine Escherichia coli

    DEFF Research Database (Denmark)

    Frydendahl, K.; Imberechts, H.; Lehmann, S.

    2001-01-01

    (STa, STb, EAST1) and heat labile LT) enterotoxins and the verocytotoxin variant 2e (VT2e). To correctly identify false negative results, an endogenous internal control targeting the E. coil 16S rRNA gene was incorporated in each test tube. The assay was evaluated using a collection of E. coil...... reference strains which have previously been examined with phenotypical assays or DNA hybridization. Furthermore, the assay was evaluated by testing porcine E. coil field strains, previously characterized. The 5' nuclease assay correctly detected the presence of virulence genes in all reference strains....... When testing field strains there was generally excellent agreement with results obtained by laboratories in Belgium and Germany. In conclusion, the 5' nuclease assay developed is a fast and specific tool for detection of E. coli virulence genes in the veterinary diagnostic laboratory....

  20. Identification and Structural Basis of Binding to Host Lung Glycogen by Streptococcal Virulence Factors

    Energy Technology Data Exchange (ETDEWEB)

    Lammerts van Bueren,A.; Higgins, M.; Wang, D.; Burke, R.; Boraston, A.

    2007-01-01

    The ability of pathogenic bacteria to recognize host glycans is often essential to their virulence. Here we report structure-function studies of previously uncharacterized glycogen-binding modules in the surface-anchored pullulanases from Streptococcus pneumoniae (SpuA) and Streptococcus pyogenes (PulA). Multivalent binding to glycogen leads to a strong interaction with alveolar type II cells in mouse lung tissue. X-ray crystal structures of the binding modules reveal a novel fusion of tandem modules into single, bivalent functional domains. In addition to indicating a structural basis for multivalent attachment, the structure of the SpuA modules in complex with carbohydrate provides insight into the molecular basis for glycogen specificity. This report provides the first evidence that intracellular lung glycogen may be a novel target of pathogenic streptococci and thus provides a rationale for the identification of the streptococcal {alpha}-glucan-metabolizing machinery as virulence factors.

  1. Invasion thresholds and the evolution of nonequilibrium virulence.

    Science.gov (United States)

    Bull, James J; Ebert, Dieter

    2008-02-01

    The enterprise of virulence management attempts to predict how social practices and other factors affect the evolution of parasite virulence. These predictions are often based on parasite optima or evolutionary equilibria derived from models of host-parasite dynamics. Yet even when such models accurately capture the parasite optima, newly invading parasites will typically not be at their optima. Here we show that parasite invasion of a host population can occur despite highly nonoptimal virulence. Fitness improvements soon after invasion may proceed through many steps with wide changes in virulence, because fitness depends on transmission as well as virulence, and transmission improvements can overwhelm nonoptimal virulence. This process is highly sensitive to mutation supply and the strength of selection. Importantly, the same invasion principle applies to the evolution of established parasites, whenever mutants arise that overcome host immunity/resistance. A host population may consequently experience repeated invasions of new parasite variants and possible large shifts in virulence as it evolves in an arms race with the parasite. An experimental study of phage lysis time and examples of mammalian viruses matching some of these characteristics are reviewed.

  2. Xylose donor transport is critical for fungal virulence.

    Directory of Open Access Journals (Sweden)

    Lucy X Li

    2018-01-01

    Full Text Available Cryptococcus neoformans, an AIDS-defining opportunistic pathogen, is the leading cause of fungal meningitis worldwide and is responsible for hundreds of thousands of deaths annually. Cryptococcal glycans are required for fungal survival in the host and for pathogenesis. Most glycans are made in the secretory pathway, although the activated precursors for their synthesis, nucleotide sugars, are made primarily in the cytosol. Nucleotide sugar transporters are membrane proteins that solve this topological problem, by exchanging nucleotide sugars for the corresponding nucleoside phosphates. The major virulence factor of C. neoformans is an anti-phagocytic polysaccharide capsule that is displayed on the cell surface; capsule polysaccharides are also shed from the cell and impede the host immune response. Xylose, a neutral monosaccharide that is absent from model yeast, is a significant capsule component. Here we show that Uxt1 and Uxt2 are both transporters specific for the xylose donor, UDP-xylose, although they exhibit distinct subcellular localization, expression patterns, and kinetic parameters. Both proteins also transport the galactofuranose donor, UDP-galactofuranose. We further show that Uxt1 and Uxt2 are required for xylose incorporation into capsule and protein; they are also necessary for C. neoformans to cause disease in mice, although surprisingly not for fungal viability in the context of infection. These findings provide a starting point for deciphering the substrate specificity of an important class of transporters, elucidate a synthetic pathway that may be productively targeted for therapy, and contribute to our understanding of fundamental glycobiology.

  3. Palm Functional Traits: which traits matter and how do we measure them?

    DEFF Research Database (Denmark)

    Eiserhardt, Wolf L.; Balslev, Henrik; Barfod, Anders S.

    role of palms in tropical forest ecosystems. We review data availability for palms for four traits that are commonly used in functional plant ecology: specific leaf area (SLA), wood density, seed size, and maximum height. We suggest that palm functional ecology is impeded by some of the standard...

  4. Multiplex-PCR-Based Screening and Computational Modeling of Virulence Factors and T-Cell Mediated Immunity in Helicobacter pylori Infections for Accurate Clinical Diagnosis.

    Directory of Open Access Journals (Sweden)

    Sinem Oktem-Okullu

    Full Text Available The outcome of H. pylori infection is closely related with bacteria's virulence factors and host immune response. The association between T cells and H. pylori infection has been identified, but the effects of the nine major H. pylori specific virulence factors; cagA, vacA, oipA, babA, hpaA, napA, dupA, ureA, ureB on T cell response in H. pylori infected patients have not been fully elucidated. We developed a multiplex- PCR assay to detect nine H. pylori virulence genes with in a three PCR reactions. Also, the expression levels of Th1, Th17 and Treg cell specific cytokines and transcription factors were detected by using qRT-PCR assays. Furthermore, a novel expert derived model is developed to identify set of factors and rules that can distinguish the ulcer patients from gastritis patients. Within all virulence factors that we tested, we identified a correlation between the presence of napA virulence gene and ulcer disease as a first data. Additionally, a positive correlation between the H. pylori dupA virulence factor and IFN-γ, and H. pylori babA virulence factor and IL-17 was detected in gastritis and ulcer patients respectively. By using computer-based models, clinical outcomes of a patients infected with H. pylori can be predicted by screening the patient's H. pylori vacA m1/m2, ureA and cagA status and IFN-γ (Th1, IL-17 (Th17, and FOXP3 (Treg expression levels. Herein, we report, for the first time, the relationship between H. pylori virulence factors and host immune responses for diagnostic prediction of gastric diseases using computer-based models.

  5. Multiplex-PCR-Based Screening and Computational Modeling of Virulence Factors and T-Cell Mediated Immunity in Helicobacter pylori Infections for Accurate Clinical Diagnosis.

    Science.gov (United States)

    Oktem-Okullu, Sinem; Tiftikci, Arzu; Saruc, Murat; Cicek, Bahattin; Vardareli, Eser; Tozun, Nurdan; Kocagoz, Tanil; Sezerman, Ugur; Yavuz, Ahmet Sinan; Sayi-Yazgan, Ayca

    2015-01-01

    The outcome of H. pylori infection is closely related with bacteria's virulence factors and host immune response. The association between T cells and H. pylori infection has been identified, but the effects of the nine major H. pylori specific virulence factors; cagA, vacA, oipA, babA, hpaA, napA, dupA, ureA, ureB on T cell response in H. pylori infected patients have not been fully elucidated. We developed a multiplex- PCR assay to detect nine H. pylori virulence genes with in a three PCR reactions. Also, the expression levels of Th1, Th17 and Treg cell specific cytokines and transcription factors were detected by using qRT-PCR assays. Furthermore, a novel expert derived model is developed to identify set of factors and rules that can distinguish the ulcer patients from gastritis patients. Within all virulence factors that we tested, we identified a correlation between the presence of napA virulence gene and ulcer disease as a first data. Additionally, a positive correlation between the H. pylori dupA virulence factor and IFN-γ, and H. pylori babA virulence factor and IL-17 was detected in gastritis and ulcer patients respectively. By using computer-based models, clinical outcomes of a patients infected with H. pylori can be predicted by screening the patient's H. pylori vacA m1/m2, ureA and cagA status and IFN-γ (Th1), IL-17 (Th17), and FOXP3 (Treg) expression levels. Herein, we report, for the first time, the relationship between H. pylori virulence factors and host immune responses for diagnostic prediction of gastric diseases using computer-based models.

  6. Comparative proteome analysis of two Streptococcus agalactiae strains from cultured tilapia with different virulence.

    Science.gov (United States)

    Li, Wei; Su, You-Lu; Mai, Yong-Zhan; Li, Yan-Wei; Mo, Ze-Quan; Li, An-Xing

    2014-05-14

    Streptococcus agalactiae is a major piscine pathogen, which causes significant morbidity and mortality among numerous fish species, and results in huge economic losses to aquaculture. Many S. agalactiae strains showing different virulence characteristics have been isolated from infected tilapia in different geographical regions throughout South China in the recent years, including natural attenuated S. agalactiae strain TFJ0901 and virulent S. agalactiae strain THN0901. In the present study, survival of tilapia challenged with S. agalactiae strain TFJ0901 and THN0901 (10(7)CFU/fish) were 93.3% and 13.3%, respectively. Moreover, there are severe lesions of the examined tissues in tilapia infected with strain THN0901, but no significant histopathological changes were observed in tilapia infected with the strain TFJ0901. In order to elucidate the factors responsible for the invasive potential of S. agalactiae between two strains TFJ0901 and THN0901, a comparative proteome analysis was applied to identify the different protein expression profiles between the two strains. 506 and 508 cellular protein spots of S. agalactiae TFJ0901 and THN0901 were separated by two dimensional electrophoresis, respectively. And 34 strain-specific spots, corresponding to 27 proteins, were identified successfully by MALDI-TOF mass spectrometry. Among them, 23 proteins presented exclusively in S. agalactiae TFJ0901 or THN0901, and the other 4 proteins presented in different isomeric forms between TFJ0901 and THN0901. Most of the strain-specific proteins were just involved in metabolic pathways, while 7 of them were presumed to be responsible for the virulence differences of S. agalactiae strain TFJ0901 and THN0901, including molecular chaperone DnaJ, dihydrolipoamide dehydrogenase, thioredoxin, manganese-dependent inorganic pyrophosphatase, elongation factor Tu, bleomycin resistance protein and cell division protein DivIVA. These virulence-associated proteins may contribute to identify new

  7. Coordinated Regulation of Virulence during Systemic Infection of Salmonella enterica serovar Typhimurium

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hyunjin; McDermott, Jason E.; Porwollik, Steffen; Mcclelland, Michael; Heffron, Fred

    2009-02-20

    Salmonella must respond to a myriad of environmental cues during infection of a mouse and express specific subsets of genes in a temporal and spatial manner to subvert the host defense mechanisms but these regulatory pathways are poorly established. To unravel how micro-environmental signals are processed and integrated into coordinated action, we constructed in-frame non-polar deletions of 84 regulators inferred to play a role in Salmonella typhimurium virulence and tested them in three virulence assays (intraperitoneal (i.p.), and intragastric (i.g.) infection in BALB/c mice, and persistence in SvJ129 mice). Overall 36 regulators were identified that were less virulent in at least one assay, and of those, 15 regulators were required for systemic mouse infection in an acute infection model. As a first step towards understanding the interplay between a pathogen and its host from a systems biology standpoint we focused on these 15 genes. Transcriptional profiles were obtained for each of these 15 regulators from strains grown under four different environmental conditions. These results as well as publicly available transcriptional profiles were analyzed using both network inference and cluster analysis algorithms. The analysis predicts a regulatory network in which all 15 regulators control a specific set of genes necessary for Salmonella to cause systemic infection. We tested the regulatory model by expressing a subset of the regulators in trans and monitoring transcription of 7 known virulence factors located within Salmonella pathogenicity island 2 (SPI-2). These experiments validated the regulatory model and showed that, for these 7 genes, the response regulator SsrB and the marR type regulator SlyA co-regulate in a regulatory cascade by integrating multiple signals.

  8. Traits contributing to the autistic spectrum.

    Directory of Open Access Journals (Sweden)

    Colin D Steer

    2010-09-01

    Full Text Available It is increasingly recognised that traits associated with autism reflect a spectrum with no clear boundary between typical and atypical behaviour. Dimensional traits are needed to investigate the broader autism phenotype.Ninety-three individual measures reflecting components of social, communication and repetitive behaviours characterising autistic spectrum disorder (ASD were identified between the ages of 6 months and 9 years from the ALSPAC database. Using missing value imputation, data for 13,138 children were analysed. Factor analysis suggested the existence of 7 factors explaining 85% of the variance. The factors were labelled: verbal ability, language acquisition, social understanding, semantic-pragmatic skills, repetitive-stereotyped behaviour, articulation and social inhibition. Four factors (1, 3, 5 and 7 were specific to ASD being more strongly associated with this phenotype than other co-morbid conditions while other factors were more associated with learning difficulties and specific language impairment. Nevertheless, all 7 factors contributed independently to the explanation of ASD (p<0.001. Exploration of putative genetic causal factors such as variants in the CNTNAP2 gene showed a varying pattern of associations with these traits. An alternative predictive model of ASD was derived using four individual measures: the coherence subscale of the Children's Communication Checklist (9y, the Social and Communication Disorders Checklist (91 m, repetitive behaviour (69 m and the sociability subscale of the Emotionality Activity and Sociability measure (38 m. Although univarably these traits performed better than some factors, their combined explanations of ASD were similar (R(2 =  0.48.These results support the fractional nature of ASD with different aetiological origins for these components despite pleiotropic genetic effects being observed. These traits are likely to be useful in the exploration of ASD.

  9. Polyamines Are Required for Virulence in Salmonella enterica Serovar Typhimurium

    DEFF Research Database (Denmark)

    Jelsbak, Lotte; Thomsen, Line Elnif; Wallrodt, Inke

    2012-01-01

    for studying typhoid fever. Central to its virulence are two major virulence loci Salmonella Pathogenicity Island 1 and 2 (SPI1 and SPI2). SPI1 promotes invasion of epithelial cells, whereas SPI2 enables S. Typhimurium to survive and proliferate within specialized compartments inside host cells. In this study......, we show that an S. Typhimurium polyamine mutant is defective for invasion, intracellular survival, killing of the nematode Caenorhabditis elegans and systemic infection of the mouse model of typhoid fever. Virulence of the mutant could be restored by genetic complementation, and invasion...

  10. Investigating the Association between Autistic-Like and Internalizing Traits in a Community-Based Twin Sample

    Science.gov (United States)

    Hallett, Victoria; Ronald, Angelica; Happe, Francesca

    2009-01-01

    The phenotypic and etiologic relation between internalizing and autistic-like traits is studied using a community-based twin sample. Internalizing and autistic-like traits showed moderate phenotypic overlap but have specific genetic influences.

  11. Contemporary Ecological Interactions Improve Models of Past Trait Evolution.

    Science.gov (United States)

    Hutchinson, Matthew C; Gaiarsa, Marília P; Stouffer, Daniel B

    2018-02-20

    Despite the fact that natural selection underlies both traits and interactions, evolutionary models often neglect that ecological interactions may, and in many cases do, influence the evolution of traits. Here, we explore the interdependence of ecological interactions and functional traits in the pollination associations of hawkmoths and flowering plants. Specifically, we develop an adaptation of the Ornstein-Uhlenbeck model of trait evolution that allows us to study the influence of plant corolla depth and observed hawkmoth-plant interactions on the evolution of hawkmoth proboscis length. Across diverse modelling scenarios, we find that the inclusion of contemporary interactions can provide a better description of trait evolution than the null expectation. Moreover, we show that the pollination interactions provide more-likely models of hawkmoth trait evolution when interactions are considered at increasingly finescale groups of hawkmoths. Finally, we demonstrate how the results of best-fit modelling approaches can implicitly support the association between interactions and trait evolution that our method explicitly examines. In showing that contemporary interactions can provide insight into the historical evolution of hawkmoth proboscis length, we demonstrate the clear utility of incorporating additional ecological information to models designed to study past trait evolution.

  12. Sexual selection and magic traits in speciation with gene flow

    Directory of Open Access Journals (Sweden)

    Maria R. SERVEDIO, Michael KOPP

    2012-06-01

    Full Text Available The extent to which sexual selection is involved in speciation with gene flow remains an open question and the subject of much research. Here, we propose that some insight can be gained from considering the concept of magic traits (i.e., traits involved in both reproductive isolation and ecological divergence. Both magic traits and other, “non-magic”, traits can contribute to speciation via a number of specific mechanisms. We argue that many of these mechanisms are likely to differ widely in the extent to which they involve sexual selection. Furthermore, in some cases where sexual selection is present, it may be prone to inhibit rather than drive speciation. Finally, there are a priori reasons to believe that certain categories of traits are much more effective than others in driving speciation. The combination of these points suggests a classification of traits that may shed light on the broader role of sexual selection in speciation with gene flow. In particular, we suggest that sexual selection can act as a driver of speciation in some scenarios, but may play a negligible role in potentially common categories of magic traits, and may be likely to inhibit speciation in common categories of non-magic traits [Current Zoology 58 (3: 507–513, 2012].

  13. Pathogenesis of virulent and attenuated foot-and-mouth disease virus in cattle.

    Science.gov (United States)

    Arzt, Jonathan; Pacheco, Juan M; Stenfeldt, Carolina; Rodriguez, Luis L

    2017-05-02

    of the mutant is more responsible for attenuation than differences in host immunological factors. These results complement previous studies by providing data of high-granularity describing tissue-specific tropism of FMDV and by demonstrating microscopic localization of virulent and attenuated clones of the same field-strain FMDV.

  14. Quantitative trait loci and metabolic pathways

    Science.gov (United States)

    McMullen, M. D.; Byrne, P. F.; Snook, M. E.; Wiseman, B. R.; Lee, E. A.; Widstrom, N. W.; Coe, E. H.

    1998-01-01

    The interpretation of quantitative trait locus (QTL) studies is limited by the lack of information on metabolic pathways leading to most economic traits. Inferences about the roles of the underlying genes with a pathway or the nature of their interaction with other loci are generally not possible. An exception is resistance to the corn earworm Helicoverpa zea (Boddie) in maize (Zea mays L.) because of maysin, a C-glycosyl flavone synthesized in silks via a branch of the well characterized flavonoid pathway. Our results using flavone synthesis as a model QTL system indicate: (i) the importance of regulatory loci as QTLs, (ii) the importance of interconnecting biochemical pathways on product levels, (iii) evidence for “channeling” of intermediates, allowing independent synthesis of related compounds, (iv) the utility of QTL analysis in clarifying the role of specific genes in a biochemical pathway, and (v) identification of a previously unknown locus on chromosome 9S affecting flavone level. A greater understanding of the genetic basis of maysin synthesis and associated corn earworm resistance should lead to improved breeding strategies. More broadly, the insights gained in relating a defined genetic and biochemical pathway affecting a quantitative trait should enhance interpretation of the biological basis of variation for other quantitative traits. PMID:9482823

  15. Genotypes, Virulence Factors and Antimicrobial Resistance Genes of Staphylococcus aureus Isolated in Bovine Subclinical Mastitis from Eastern China

    Directory of Open Access Journals (Sweden)

    Javed Memon§, Yongchun Yang§, Jam Kashifa, Muhammad Yaqoob, Rehana Buriroa, Jamila Soomroa, Wang Liping and Fan Hongjie*

    2013-11-01

    Full Text Available This study was carried out to determine the genotypes, virulence factors and antimicrobial resistance traits of 34 Staphylococcus aureus isolated from subclinical mastitis in Eastern China. Minimal inhibitory concentration (MIC results showed resistance to erythromycin in all isolates. A high frequency of Methicillin resistant S. aureus (MRSA; 29% was observed and these isolates were also highly resistant to penicillin, oxacillin, oxytetracycline and chloramphenicol than methicillin sensitive S. aureus (MSSA isolates. Thirteen pathogenic factors and seven resistance genes including mecA and blaZ gene were checked through PCR. The spaX gene was found in all isolates, whereas cna, spaIg, nuc, clfA, fnbpB, hlA, hlB and seA were present in 35, 79, 85, 59, 35, 85, 71 and 38% isolates, respectively. Nine isolates carried a group of 8 different virulence genes. Moreover, macrolide resistance genes ermB and ermC were present in all isolates. High resistance rate against methicillin was found but no isolate was positive for mecA gene, whereas blaZ and tetK were detected in 82 and 56% isolates, respectively. Genes; fnbpA, seB, seC, seD, dfrK and tetM were not found in any isolate. The statistical association between phenotypic resistance and virulence genes showed, clfA, fnbpB, hlB and seA, were potentially associated with penicillin G, ciprofloxacin, methicillin, chloramphenicol, trimethoprim and oxytetracycline resistance (P≤0.05. REP-PCR based genotyping showed seven distinct genotypes (A-G prevalent in this region. This study reports the presence of multidrug resistant S. aureus in sub-clinical mastitis which were also highly virulent that could be a major obstacle in the treatment of mastitis in this region of China.

  16. Caenorhabditis elegans reveals novel Pseudomonas aeruginosa virulence mechanism

    NARCIS (Netherlands)

    Utari, Putri Dwi; Quax, Wim J.

    The susceptibility of Caenorhabditis elegans to different virulent phenotypes of Pseudomonas aeruginosa makes the worms an excellent model for studying host-pathogen interactions. Including the recently described liquid killing, five different killing assays are now available offering superb

  17. Molecular Detection of Virulence Genes and Antibiotic Resistance ...

    African Journals Online (AJOL)

    Pathogen, E. coli O157:H7, virulence genes, antibiotic-resistance, beef meat. Correspondence: ... box to the laboratory for further processing. Isolation and identification of ... Technologies (IDT) Inc, U.S.A. The sequences and annealing ...

  18. Sporangiospore size dimorphism is linked to virulence of Mucor circinelloides

    NARCIS (Netherlands)

    Li, C.H.; Cervantes, M.; Springer, D.J.; Boekhout, T.; Ruiz-Vazquez, R.M.; Torres-Martinez, S.R.; Heitman, J.; Lee, S.S.

    2011-01-01

    Mucor circinelloides is a zygomycete fungus and an emerging opportunistic pathogen in immunocompromised patients, especially transplant recipients and in some cases otherwise healthy individuals. We have discovered a novel example of size dimorphism linked to virulence. M. circinelloides is a

  19. Virulence Factors Associated with Enterococcus Faecalis Infective Endocarditis

    DEFF Research Database (Denmark)

    Madsen, Kristian T; Skov, Marianne N; Gill, Sabine

    2017-01-01

    INTRODUCTION: The enterococci are accountable for up to 20% of all cases of infective endocarditis, with Enterococcus faecalis being the primary causative isolate. Infective endocarditis is a life-threatening infection of the endocardium that results in the formation of vegetations. Based...... on a literature review, this paper provides an overview of the virulence factors associated with E. faecalis infective endocarditis. Furthermore, it reports the effects of active or passive immunization against some of these involved factors. INDIVIDUAL VIRULENCE FACTORS: Nine virulence factors have in particular...... been associated with E. faecalis infective endocarditis. Absence of these factors entailed attenuation of strains in both mixed- and mono-bacterial infection endocarditis models as well as in in vitro and ex vivo assays when compared to their virulence factor expressing parental strains. PATHOGENESIS...

  20. Determinants of Virulence and In Vitro Development Colocalize on a Genetic Map of Setosphaeria turcica.

    Science.gov (United States)

    Mideros, Santiago X; Chung, Chia-Lin; Wiesner-Hanks, Tyr; Poland, Jesse A; Wu, Dongliang; Fialko, Ariel A; Turgeon, B Gillian; Nelson, Rebecca J

    2018-02-01

    Generating effective and stable strategies for resistance breeding requires an understanding of the genetics of host-pathogen interactions and the implications for pathogen dynamics and evolution. Setosphaeria turcica causes northern leaf blight (NLB), an important disease of maize for which major resistance genes have been deployed. Little is known about the evolutionary dynamics of avirulence (AVR) genes in S. turcica. To test the hypothesis that there is a genetic association between avirulence and in vitro development traits, we (i) created a genetic map of S. turcica, (ii) located candidate AVRHt1 and AVRHt2 regions, and (iii) identified genetic regions associated with several in vitro development traits. A cross was generated between a race 1 and a race 23N strain, and 221 progeny were isolated. Genotyping by sequencing was used to score 2,078 single-nucleotide polymorphism markers. A genetic map spanning 1,981 centimorgans was constructed, consisting of 21 linkage groups. Genetic mapping extended prior evidence for the location and identity of the AVRHt1 gene and identified a region of interest for AVRHt2. The genetic location of AVRHt2 colocalized with loci influencing radial growth and mycelial abundance. Our data suggest a trade-off between virulence on Ht1 and Ht2 and the pathogen's vegetative growth rate. In addition, in-depth analysis of the genotypic data suggests the presence of significant duplication in the genome of S. turcica.

  1. High diversity of genetic lineages and virulence genes in nasal Staphylococcus aureus isolates from donkeys destined to food consumption in Tunisia with predominance of the ruminant associated CC133 lineage

    Directory of Open Access Journals (Sweden)

    Gharsa Haythem

    2012-10-01

    Full Text Available Abstract Background The objective of this study was to determine the genetic lineages and the incidence of antibiotic resistance and virulence determinants of nasal Staphylococcus aureus isolates of healthy donkeys destined to food consumption in Tunisia. Results Nasal swabs of 100 donkeys obtained in a large slaughterhouse in 2010 were inoculated in specific media for S. aureus and methicillin-resistant S. aureus (MRSA recovery. S. aureus was obtained in 50% of the samples, being all of isolates methicillin-susceptible (MSSA. Genetic lineages, toxin gene profile, and antibiotic resistance mechanisms were determined in recovered isolates. Twenty-five different spa-types were detected among the 50 MSSA with 9 novel spa-types. S. aureus isolates were ascribed to agr type I (37 isolates, III (7, II (4, and IV (2. Sixteen different sequence-types (STs were revealed by MLST, with seven new ones. STs belonging to clonal clomplex CC133 were majority. The gene tst was detected in 6 isolates and the gene etb in one isolate. Different combinations of enterotoxin, leukocidin and haemolysin genes were identified among S. aureus isolates. The egc-cluster-like and an incomplete egc-cluster-like were detected. Isolates resistant to penicillin, erythromycin, fusidic acid, streptomycin, ciprofloxacin, clindamycin, tetracycline, or chloramphenicol were found and the genes blaZ, erm(A, erm(C, tet(M, fusC were identified. Conclusions The nares of donkeys frequently harbor MSSA. They could be reservoirs of the ruminant-associated CC133 lineage and of toxin genes encoding TSST-1 and other virulence traits with potential implications in public health. CC133 seems to have a broader host distribution than expected.

  2. Quantitative trait loci (QTL) mapping for inflorescence length traits in ...

    African Journals Online (AJOL)

    Lablab purpureus (L.) sweet is an ancient legume species whose immature pods serve as a vegetable in south and south-east Asia. The objective of this study is to identify quantitative trait loci (QTLs) associated with quantitative traits such as inflorescence length, peduncle length from branch to axil, peduncle length from ...

  3. Associations between animal traits, carcass traits and carcass ...

    African Journals Online (AJOL)

    In this study the associations between animal traits, carcass traits and carcass classification within cattle, sheep and pigs slaughtered in a high throughput abattoir were determined. Classes of carcasses from cattle, sheep and pigs delivered for slaughter at this abattoir were recorded and analysed. Significant associations ...

  4. Invasion thresholds and the evolution of nonequilibrium virulence

    OpenAIRE

    Bull, J. J.; Ebert, D.

    2008-01-01

    Abstract The enterprise of virulence management attempts to predict how social practices and other factors affect the evolution of parasite virulence. These predictions are often based on parasite optima or evolutionary equilibria derived from models of host-parasite dynamics. Yet even when such models accurately capture the parasite optima, newly invading parasites will typically not be at their optima. Here we show that parasite invasion of a host population can occur despite highly nonopti...

  5. Investigating the ?Trojan Horse? Mechanism of Yersinia pestis Virulence

    Energy Technology Data Exchange (ETDEWEB)

    McCutchen-Maloney, S L; Fitch, J P

    2005-02-08

    Yersinia pestis, the etiological agent of plague, is a Gram-negative, highly communicable, enteric bacterium that has been responsible for three historic plague pandemics. Currently, several thousand cases of plague are reported worldwide annually, and Y. pestis remains a considerable threat from a biodefense perspective. Y. pestis infection can manifest in three forms: bubonic, septicemic, and pneumonic plague. Of these three forms, pneumonic plague has the highest fatality rate ({approx}100% if left untreated), the shortest intervention time ({approx}24 hours), and is highly contagious. Currently, there are no rapid, widely available vaccines for plague and though plague may be treated with antibiotics, the emergence of both naturally occurring and potentially engineered antibiotic resistant strains makes the search for more effective therapies and vaccines for plague of pressing concern. The virulence mechanism of this deadly bacterium involves induction of a Type III secretion system, a syringe-like apparatus that facilitates the injection of virulence factors, termed Yersinia outer membrane proteins (Yops), into the host cell. These virulence factors inhibit phagocytosis and cytokine secretion, and trigger apoptosis of the host cell. Y. pestis virulence factors and the Type III secretion system are induced thermally, when the bacterium enters the mammalian host from the flea vector, and through host cell contact (or conditions of low Ca{sup 2+} in vitro). Apart from the temperature increase from 26 C to 37 C and host cell contact (or low Ca{sup 2+} conditions), other molecular mechanisms that influence virulence induction in Y. pestis are largely uncharacterized. This project focused on characterizing two novel mechanisms that regulate virulence factor induction in Y. pestis, immunoglobulin G (IgG) binding and quorum sensing, using a real-time reporter system to monitor induction of virulence. Incorporating a better understanding of the mechanisms of virulence

  6. Virulence profiles of bacteremic extended-spectrum β-lactamase-producing Escherichia coli: association with epidemiological and clinical features.

    Directory of Open Access Journals (Sweden)

    Jesús Rodríguez-Baño

    Full Text Available There is scarce data about the importance of phylogroups and virulence factors (VF in bloodstream infections (BSI caused by extended-spectrum β-lactamase-producing Escherichia coli (ESBLEC. A prospective multicenter Spanish cohort including 191 cases of BSI due to ESBLEC was studied. Phylogroups and 25 VF genes were investigated by PCR. ESBLEC were classified into clusters according to their virulence profiles. The association of phylogropus, VF, and clusters with epidemiological features were studied using multivariate analysis. Overall, 57.6%, 26.7%, and 15.7% of isolates belonged to A/B1, D and B2 phylogroups, respectively. By multivariate analysis (adjusted OR [95% CI], virulence cluster C2 was independently associated with urinary tract source (5.05 [0.96-25.48]; cluster C4 with sources other than urinary of biliary tract (2.89 [1.05-7.93], and cluster C5 with BSI in non-predisposed patients (2.80 [0.99-7.93]. Isolates producing CTX-M-9 group ESBLs and from phylogroup D predominated among cluster C2 and C5, while CTX-M-1 group of ESBL and phylogroup B2 predominantes among C4 isolates. These results suggest that host factors and previous antimicrobial use were more important than phylogroup or specific VF in the occurrence of BSI due to ESBLEC. However, some associations between virulence clusters and some specific epidemiological features were found.

  7. The MogR Transcriptional Repressor Regulates Nonhierarchal Expression of Flagellar Motility Genes and Virulence in Listeria monocytogenes.

    Directory of Open Access Journals (Sweden)

    2006-04-01

    Full Text Available Flagella are surface structures critical for motility and virulence of many bacterial species. In Listeria monocytogenes, MogR tightly represses expression of flagellin (FlaA during extracellular growth at 37 degrees C and during intracellular infection. MogR is also required for full virulence in a murine model of infection. Using in vitro and in vivo infection models, we determined that the severe virulence defect of MogR-negative bacteria is due to overexpression of FlaA. Specifically, overproduction of FlaA in MogR-negative bacteria caused pleiotropic defects in bacterial division (chaining phenotype, intracellular spread, and virulence in mice. DNA binding and microarray analyses revealed that MogR represses transcription of all known flagellar motility genes by binding directly to a minimum of two TTTT-N(5-AAAA recognition sites positioned within promoter regions such that RNA polymerase binding is occluded. Analysis of MogR protein levels demonstrated that modulation of MogR repression activity confers the temperature-specificity to flagellar motility gene expression. Epistasis analysis revealed that MogR repression of transcription is antagonized in a temperature-dependent manner by the DegU response regulator and that DegU further regulates FlaA levels through a posttranscriptional mechanism. These studies provide the first known example to our knowledge of a transcriptional repressor functioning as a master regulator controlling nonhierarchal expression of flagellar motility genes.

  8. Virulence genes in a probiotic E. coli product with a recorded long history of safe use

    Science.gov (United States)

    Zschüttig, Anke; Beimfohr, Claudia; Geske, Thomas; Auerbach, Christian; Cook, Helen; Zimmermann, Kurt; Gunzer, Florian

    2015-01-01

    The probiotic product Symbioflor2 (DSM 17252) is a bacterial concentrate of six different Escherichia coli genotypes, whose complete genome sequences are compared here, between each other as well as to other E. coli genomes. The genome sequences of Symbioflor2 E. coli components contained a number of virulence-associated genes. Their presence seems to be in conflict with a recorded history of safe use, and with the observed low frequency of adverse effects over a period of more than 6 years. The genome sequences were used to identify unique sequences for each component, for which strain-specific hybridization probes were designed. A colonization study was conducted whereby five volunteers were exposed to an exceptionally high single dose. The results showed that the probiotic E. coli could be detected for 3 months or longer in their stools, and this was in particular the case for those components containing higher numbers of virulence-associated genes. Adverse effects from this long-term colonization were absent. Thus, the presence of the identified virulence genes does not result in a pathogenic phenotype in the genetic background of these probiotic E. coli. PMID:25883796

  9. A highly conserved metalloprotease effector enhances virulence in the maize anthracnose fungus Colletotrichum graminicola.

    Science.gov (United States)

    Sanz-Martín, José M; Pacheco-Arjona, José Ramón; Bello-Rico, Víctor; Vargas, Walter A; Monod, Michel; Díaz-Mínguez, José M; Thon, Michael R; Sukno, Serenella A

    2016-09-01

    Colletotrichum graminicola causes maize anthracnose, an agronomically important disease with a worldwide distribution. We have identified a fungalysin metalloprotease (Cgfl) with a role in virulence. Transcriptional profiling experiments and live cell imaging show that Cgfl is specifically expressed during the biotrophic stage of infection. To determine whether Cgfl has a role in virulence, we obtained null mutants lacking Cgfl and performed pathogenicity and live microscopy assays. The appressorium morphology of the null mutants is normal, but they exhibit delayed development during the infection process on maize leaves and roots, showing that Cgfl has a role in virulence. In vitro chitinase activity assays of leaves infected with wild-type and null mutant strains show that, in the absence of Cgfl, maize leaves exhibit increased chitinase activity. Phylogenetic analyses show that Cgfl is highly conserved in fungi. Similarity searches, phylogenetic analysis and transcriptional profiling show that C. graminicola encodes two LysM domain-containing homologues of Ecp6, suggesting that this fungus employs both Cgfl-mediated and LysM protein-mediated strategies to control chitin signalling. © 2015 BSPP and John Wiley & Sons Ltd.

  10. Lvr, a Signaling System That Controls Global Gene Regulation and Virulence in Pathogenic Leptospira

    Science.gov (United States)

    Adhikarla, Haritha; Wunder, Elsio A.; Mechaly, Ariel E.; Mehta, Sameet; Wang, Zheng; Santos, Luciane; Bisht, Vimla; Diggle, Peter; Murray, Gerald; Adler, Ben; Lopez, Francesc; Townsend, Jeffrey P.; Groisman, Eduardo; Picardeau, Mathieu; Buschiazzo, Alejandro; Ko, Albert I.

    2018-01-01

    Leptospirosis is an emerging zoonotic disease with more than 1 million cases annually. Currently there is lack of evidence for signaling pathways involved during the infection process of Leptospira. In our comprehensive genomic analysis of 20 Leptospira spp. we identified seven pathogen-specific Two-Component System (TCS) proteins. Disruption of two these TCS genes in pathogenic Leptospira strain resulted in loss-of-virulence in a hamster model of leptospirosis. Corresponding genes lvrA and lvrB (leptospira virulence regulator) are juxtaposed in an operon and are predicted to encode a hybrid histidine kinase and a hybrid response regulator, respectively. Transcriptome analysis of lvr mutant strains with disruption of one (lvrB) or both genes (lvrA/B) revealed global transcriptional regulation of 850 differentially expressed genes. Phosphotransfer assays demonstrated that LvrA phosphorylates LvrB and predicted further signaling downstream to one or more DNA-binding response regulators, suggesting that it is a branched pathway. Phylogenetic analyses indicated that lvrA and lvrB evolved independently within different ecological lineages in Leptospira via gene duplication. This study uncovers a novel-signaling pathway that regulates virulence in pathogenic Leptospira (Lvr), providing a framework to understand the molecular bases of regulation in this life-threatening bacterium. PMID:29600195

  11. VarR controls colonization and virulence in the marine macroalgal pathogen Nautella italica R11

    Directory of Open Access Journals (Sweden)

    Melissa eGardiner

    2015-10-01

    Full Text Available There is increasing evidence to suggest that macroalgae (seaweeds are susceptible to infectious disease. However, to date, little is known about the mechanisms that facilitate the colonization and virulence of microbial seaweed pathogens. One well-described example of a seaweed disease is the bleaching of the red alga Delisea pulchra, which can be caused by the bacterium Nautella italica R11, a member of the Roseobacter clade. This pathogen contains a unique luxR-type gene, varR, which we hypothesize controls its colonization and virulence. We show here that a varR knock-out strain is deficient in its ability to cause disease in D. pulchra and is defective in biofilm formation and attachment to a common algal polysaccharide. Moreover complementation of the varR gene in trans can restore these functions to the wild type levels. Proteomic analysis of bacterial cells in planktonic and biofilm growth highlight the potential importance of nitrogen scavenging, mobilization of energy reserves, and stress resistance in the biofilm lifestyle of N. italica R11. Moreover, we show that VarR regulates the expression of a specific subset of biofilm-associated proteins. Taken together these data suggest that VarR controls colonization and persistence of N. italica R11 on the surface of a macroalgal host and that it is an important regulator of virulence.

  12. Glycosylphosphatidylinositol-Anchored Proteins in Fusarium graminearum: Inventory, Variability, and Virulence

    Science.gov (United States)

    Rittenour, William R.; Harris, Steven D.

    2013-01-01

    The contribution of cell surface proteins to plant pathogenicity of fungi is not well understood. As such, the objective of this study was to investigate the functions and importance of glycosylphosphatidylinositol-anchored proteins (GPI-APs) in the wheat pathogen F. graminearum. GPI-APs are surface proteins that are attached to either the membrane or cell wall. In order to simultaneously disrupt several GPI-APs, a phosphoethanolamine transferase-encoding gene gpi7 was deleted and the resultant mutant characterized in terms of growth, development, and virulence. The Δgpi7 mutants exhibited slower radial growth rates and aberrantly shaped macroconidia. Furthermore, virulence tests and microscopic analyses indicated that Gpi7 is required for ramification of the fungus throughout the rachis of wheat heads. In parallel, bioinformatics tools were utilized to predict and inventory GPI-APs within the proteome of F. graminearum. Two of the genes identified in this screen (FGSG_01588 and FGSG_08844) displayed isolate-specific length variability as observed for other fungal cell wall adhesion genes. Nevertheless, deletion of these genes failed to reveal obvious defects in growth, development, or virulence. This research demonstrates the global importance of GPI-APs to in planta proliferation in F. graminearum, and also highlights the potential of individual GPI-APs as diagnostic markers. PMID:24312325

  13. 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.

  14. Analysis of antimicrobial susceptibility and virulence factors in Helicobacter pylori clinical isolates

    Directory of Open Access Journals (Sweden)

    Mendonça Sergio

    2003-08-01

    Full Text Available Abstract Background In this study, we evaluated the prevalence of primary resistance of Brazilian H. pylori isolates to metronidazole, clarithromycin, amoxicillin, tetracycline, and furazolidone. In addition, the vacA, iceA, cagA and cagE genotypes of strains isolated from Brazilian patients were determined and associated with clinical data in an effort to correlate these four virulence markers and antibiotic resistance. Methods H. pylori was cultured in 155 H. pylori-positive patients and MICs for metronidazole, clarithromycin, amoxicillin, tetracycline, and furazolidone were determined by the agar dilution method. Genomic DNA was extracted, and allelic variants of vacA, iceA, cagA and cagE were identified by the polymerase chain reaction. Results There was a strong association between the vacA s1/cagA -positive genotype and peptic ulcer disease (OR = 5.42, 95% CI 2.6–11.3, p = 0.0006. Additionally, infection by more virulent strains may protect against GERD, since logistic regression showed a negative association between the more virulent strain, vacA s1/cagA-positive genotype and GERD (OR = 0.26, 95% CI 0.08–0.8, p = 0.03. Resistance to metronidazole was detected in 75 patients (55%, to amoxicillin in 54 individuals (38%, to clarithromycin in 23 patients (16%, to tetracycline in 13 patients (9%, and to furazolidone in 19 individuals (13%. No significant correlation between pathogenicity and resistance or susceptibility was detected when MIC values for each antibiotic were compared with different vacA, iceA, cagA and cagE genotypes. Conclusion The analysis of virulence genes revealed a specific association between H. pylori strains and clinical outcome, furthermore, no significant association was detected among pathogenicity and resistance or susceptibility.

  15. Molecular adaptation of a plant-bacterium outer membrane protease towards plague virulence factor Pla

    Science.gov (United States)

    2011-01-01

    Background Omptins are a family of outer membrane proteases that have spread by horizontal gene transfer in Gram-negative bacteria that infect vertebrates or plants. Despite structural similarity, the molecular functions of omptins differ in a manner that reflects the life style of their host bacteria. To simulate the molecular adaptation of omptins, we applied site-specific mutagenesis to make Epo of the plant pathogenic Erwinia pyrifoliae exhibit virulence-associated functions of its close homolog, the plasminogen activator Pla of Yersinia pestis. We addressed three virulence-associated functions exhibited by Pla, i.e., proteolytic activation of plasminogen, proteolytic degradation of serine protease inhibitors, and invasion into human cells. Results Pla and Epo expressed in Escherichia coli are both functional endopeptidases and cleave human serine protease inhibitors, but Epo failed to activate plasminogen and to mediate invasion into a human endothelial-like cell line. Swapping of ten amino acid residues at two surface loops of Pla and Epo introduced plasminogen activation capacity in Epo and inactivated the function in Pla. We also compared the structure of Pla and the modeled structure of Epo to analyze the structural variations that could rationalize the different proteolytic activities. Epo-expressing bacteria managed to invade human cells only after all extramembranous residues that differ between Pla and Epo and the first transmembrane β-strand had been changed. Conclusions We describe molecular adaptation of a protease from an environmental setting towards a virulence factor detrimental for humans. Our results stress the evolvability of bacterial β-barrel surface structures and the environment as a source of progenitor virulence molecules of human pathogens. PMID:21310089

  16. Proteomics Analysis Reveals Previously Uncharacterized Virulence Factors in Vibrio proteolyticus

    Directory of Open Access Journals (Sweden)

    Ann Ray

    2016-07-01

    Full Text Available Members of the genus Vibrio include many pathogens of humans and marine animals that share genetic information via horizontal gene transfer. Hence, the Vibrio pan-genome carries the potential to establish new pathogenic strains by sharing virulence determinants, many of which have yet to be characterized. Here, we investigated the virulence properties of Vibrio proteolyticus, a Gram-negative marine bacterium previously identified as part of the Vibrio consortium isolated from diseased corals. We found that V. proteolyticus causes actin cytoskeleton rearrangements followed by cell lysis in HeLa cells in a contact-independent manner. In search of the responsible virulence factor involved, we determined the V. proteolyticus secretome. This proteomics approach revealed various putative virulence factors, including active type VI secretion systems and effectors with virulence toxin domains; however, these type VI secretion systems were not responsible for the observed cytotoxic effects. Further examination of the V. proteolyticus secretome led us to hypothesize and subsequently demonstrate that a secreted hemolysin, belonging to a previously uncharacterized clan of the leukocidin superfamily, was the toxin responsible for the V. proteolyticus-mediated cytotoxicity in both HeLa cells and macrophages. Clearly, there remains an armory of yet-to-be-discovered virulence factors in the Vibrio pan-genome that will undoubtedly provide a wealth of knowledge on how a pathogen can manipulate host cells.

  17. Plasma membrane lipids and their role in fungal virulence.

    Science.gov (United States)

    Rella, Antonella; Farnoud, Amir M; Del Poeta, Maurizio

    2016-01-01

    There has been considerable evidence in recent years suggesting that plasma membrane lipids are important regulators of fungal pathogenicity. Various glycolipids have been shown to impart virulent properties in several fungal species, while others have been shown to play a role in host defense. In addition to their role as virulence factors, lipids also contribute to other virulence mechanisms such as drug resistance, biofilm formation, and release of extracellular vesicles. In addition, lipids also affect the mechanical properties of the plasma membrane through the formation of packed microdomains composed mainly of sphingolipids and sterols. Changes in the composition of lipid microdomains have been shown to disrupt the localization of virulence factors and affect fungal pathogenicity. This review gathers evidence on the various roles of plasma membrane lipids in fungal virulence and how lipids might contribute to the different processes that occur during infection and treatment. Insight into the role of lipids in fungal virulence can lead to an improved understanding of the process of fungal pathogenesis and the development of new lipid-mediated therapeutic strategies. Published by Elsevier Ltd.

  18. Virulence potential of Staphylococcus aureus isolates from Buruli ulcer patients.

    Science.gov (United States)

    Amissah, Nana Ama; Chlebowicz, Monika A; Ablordey, Anthony; Tetteh, Caitlin S; Prah, Isaac; van der Werf, Tjip S; Friedrich, Alex W; van Dijl, Jan Maarten; Stienstra, Ymkje; Rossen, John W

    2017-06-01

    Buruli ulcer (BU) is a necrotizing infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. BU wounds may also be colonized with other microorganisms including Staphylococcus aureus. This study aimed to characterize the virulence factors of S. aureus isolated from BU patients. Previously sequenced genomes of 21 S. aureus isolates from BU patients were screened for the presence of virulence genes. The results show that all S. aureus isolates harbored on their core genomes genes for known virulence factors like α-hemolysin, and the α- and β-phenol soluble modulins. Besides the core genome virulence genes, mobile genetic elements (MGEs), i.e. prophages, genomic islands, pathogenicity islands and a Staphylococcal cassette chromosome (SCC) were found to carry different combinations of virulence factors, among them genes that are known to encode factors that promote immune evasion, superantigens and Panton-Valentine Leucocidin. The present observations imply that the S. aureus isolates from BU patients harbor a diverse repertoire of virulence genes that may enhance bacterial survival and persistence in the wound environment and potentially contribute to delayed wound healing. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

  19. Separation of trait and state in stuttering.

    Science.gov (United States)

    Connally, Emily L; Ward, David; Pliatsikas, Christos; Finnegan, Sarah; Jenkinson, Mark; Boyles, Rowan; Watkins, Kate E

    2018-04-06

    Stuttering is a disorder in which the smooth flow of speech is interrupted. People who stutter show structural and functional abnormalities in the speech and motor system. It is unclear whether functional differences reflect general traits of the disorder or are specifically related to the dysfluent speech state. We used a hierarchical approach to separate state and trait effects within stuttering. We collected sparse-sampled functional MRI during two overt speech tasks (sentence reading and picture description) in 17 people who stutter and 16 fluent controls. Separate analyses identified indicators of: (1) general traits of people who stutter; (2) frequency of dysfluent speech states in subgroups of people who stutter; and (3) the differences between fluent and dysfluent states in people who stutter. We found that reduced activation of left auditory cortex, inferior frontal cortex bilaterally, and medial cerebellum were general traits that distinguished fluent speech in people who stutter from that of controls. The stuttering subgroup with higher frequency of dysfluent states during scanning (n = 9) had reduced activation in the right subcortical grey matter, left temporo-occipital cortex, the cingulate cortex, and medial parieto-occipital cortex relative to the subgroup who were more fluent (n = 8). Finally, during dysfluent states relative to fluent ones, there was greater activation of inferior frontal and premotor cortex extending into the frontal operculum, bilaterally. The above differences were seen across both tasks. Subcortical state effects differed according to the task. Overall, our data emphasise the independence of trait and state effects in stuttering. © 2018 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  20. Quantitative trait loci for fertility traits in Finnish Ayrshire cattle

    Directory of Open Access Journals (Sweden)

    Viitala Sirja M

    2008-03-01

    Full Text Available Abstract A whole genome scan was carried out to detect quantitative trait loci (QTL for fertility traits in Finnish Ayrshire cattle. The mapping population consisted of 12 bulls and 493 sons. Estimated breeding values for days open, fertility treatments, maternal calf mortality and paternal non-return rate were used as phenotypic data. In a granddaughter design, 171 markers were typed on all 29 bovine autosomes. Associations between markers and traits were analysed by multiple marker regression. Multi-trait analyses were carried out with a variance component based approach for the chromosomes and trait combinations, which were observed significant in the regression method. Twenty-two chromosome-wise significant QTL were detected. Several of the detected QTL areas were overlapping with milk production QTL previously identified in the same population. Multi-trait QTL analyses were carried out to test if these effects were due to a pleiotropic QTL affecting fertility and milk yield traits or to linked QTL causing the effects. This distinction could only be made with confidence on BTA1 where a QTL affecting milk yield is linked to a pleiotropic QTL affecting days open and fertility treatments.

  1. Mapping local and global variability in plant trait distributions

    Energy Technology Data Exchange (ETDEWEB)

    Butler, Ethan E.; Datta, Abhirup; Flores-Moreno, Habacuc; Chen, Ming; Wythers, Kirk R.; Fazayeli, Farideh; Banerjee, Arindam; Atkin, Owen K.; Kattge, Jens; Amiaud, Bernard; Blonder, Benjamin; Boenisch, Gerhard; Bond-Lamberty, Ben; Brown, Kerry A.; Byun, Chaeho; Campetella, Giandiego; Cerabolini, Bruno E. L.; Cornelissen, Johannes H. C.; Craine, Joseph M.; Craven, Dylan; de Vries, Franciska T.; Díaz, Sandra; Domingues, Tomas F.; Forey, Estelle; González-Melo, Andrés; Gross, Nicolas; Han, Wenxuan; Hattingh, Wesley N.; Hickler, Thomas; Jansen, Steven; Kramer, Koen; Kraft, Nathan J. B.; Kurokawa, Hiroko; Laughlin, Daniel C.; Meir, Patrick; Minden, Vanessa; Niinemets, Ülo; Onoda, Yusuke; Peñuelas, Josep; Read, Quentin; Sack, Lawren; Schamp, Brandon; Soudzilovskaia, Nadejda A.; Spasojevic, Marko J.; Sosinski, Enio; Thornton, Peter E.; Valladares, Fernando; van Bodegom, Peter M.; Williams, Mathew; Wirth, Christian; Reich, Peter B.

    2017-12-01

    Accurate trait-environment relationships and global maps of plant trait distributions represent a needed stepping stone in global biogeography and are critical constraints of key parameters for land models. Here, we use a global data set of plant traits to map trait distributions closely coupled to photosynthesis and foliar respiration: specific leaf area (SLA), and dry mass-based concentrations of leaf nitrogen (Nm) and phosphorus (Pm); We propose two models to extrapolate geographically sparse point data to continuous spatial surfaces. The first is a categorical model using species mean trait values, categorized into plant functional types (PFTs) and extrapolating to PFT occurrence ranges identified by remote sensing. The second is a Bayesian spatial model that incorporates information about PFT, location and environmental covariates to estimate trait distributions. Both models are further stratified by varying the number of PFTs; The performance of the models was evaluated based on their explanatory and predictive ability. The Bayesian spatial model leveraging the largest number of PFTs produced the best maps; The interpolation of full trait distributions enables a wider diversity of vegetation to be represented across the land surface. These maps may be used as input to Earth System Models and to evaluate other estimates of functional diversity.

  2. Response Monitoring and Adjustment: Differential Relations with Psychopathic Traits

    Science.gov (United States)

    Bresin, Konrad; Finy, M. Sima; Sprague, Jenessa; Verona, Edelyn

    2014-01-01

    Studies on the relation between psychopathy and cognitive functioning often show mixed results, partially because different factors of psychopathy have not been considered fully. Based on previous research, we predicted divergent results based on a two-factor model of psychopathy (interpersonal-affective traits and impulsive-antisocial traits). Specifically, we predicted that the unique variance of interpersonal-affective traits would be related to increased monitoring (i.e., error-related negativity) and adjusting to errors (i.e., post-error slowing), whereas impulsive-antisocial traits would be related to reductions in these processes. Three studies using a diverse selection of assessment tools, samples, and methods are presented to identify response monitoring correlates of the two main factors of psychopathy. In Studies 1 (undergraduates), 2 (adolescents), and 3 (offenders), interpersonal-affective traits were related to increased adjustment following errors and, in Study 3, to enhanced monitoring of errors. Impulsive-antisocial traits were not consistently related to error adjustment across the studies, although these traits were related to a deficient monitoring of errors in Study 3. The results may help explain previous mixed findings and advance implications for etiological models of psychopathy. PMID:24933282

  3. Lessons from the use of genetically modified Drosophila melanogaster in ecological studies: Hsf mutant lines show highly trait-specific performance in field and laboratory thermal assays

    DEFF Research Database (Denmark)

    Sørensen, Jesper Givskov; Loeschcke, Volker; Kristensen, Torsten Nygård

    2009-01-01

    . 2.  We have tested the importance of inducible heat shock proteins (Hsps) under different thermal conditions using two heat shock factor (Hsf) mutant lines (either able (Hsf+) or unable (Hsf0) to mount a heat stress response) and an outbred laboratory adapted wild-type line of Drosophila......1.  Laboratory studies on genetically modified strains may reveal important information on mechanisms involved in coping with thermal stress. However, to address the evolutionary significance of specific genes or physiological mechanisms, ecologically relevant field tests should also be performed...

  4. Quantitative Trait Loci in Inbred Lines

    NARCIS (Netherlands)

    Jansen, R.C.

    2001-01-01

    Quantitative traits result from the influence of multiple genes (quantitative trait loci) and environmental factors. Detecting and mapping the individual genes underlying such 'complex' traits is a difficult task. Fortunately, populations obtained from crosses between inbred lines are relatively

  5. Aureusimines in Staphylococcus aureus are not involved in virulence.

    Science.gov (United States)

    Sun, Fei; Cho, Hoonsik; Jeong, Do-Won; Li, Chunling; He, Chuan; Bae, Taeok

    2010-12-29

    Recently, dipeptide aureusimines were reported to activate expression of staphylococcal virulence genes, such as alpha-hemolysin, and increase S. aureus virulence. Surprisingly, most of the virulence genes affected by aureusimines form part of the regulon of the SaeRS two component system (TCS), raising the possibility that SaeRS might be directly or indirectly involved in the aureusimine-dependent signaling process. Using HPLC analyses, we confirmed that a transposon mutant of ausA, the gene encoding the aureusimine dipeptide synthesis enzyme, does not produce dipeptides. However, the transposon mutant showed normal hemolysis activity and alpha-hemolysin/SaeP production. Furthermore, the P1 promoter of the sae operon, one of the targets of the SaeRS TCS, showed normal transcription activity. Moreover, in contrast to the original report, the ausA transposon mutant did not exhibit attenuated virulence in an animal infection model. DNA sequencing revealed that the ausA deletion mutant used in the original study has an 83 nt-duplication in saeS. Hemolysis activity of the original mutant was restored by a plasmid carrying the sae operon. A mutant of the sae operon showed elevated resistance to chloramphenicol and erythromycin, two antibiotics widely used during staphylococcal mutagenesis. At 43°C in the presence of erythromycin and aeration, the conditions typically employed for staphylococcal mutagenesis, an saeR transposon mutant grew much faster than a control mutant and the saeR mutant was highly enriched in a mixed culture experiment. Our results show that the previously reported roles of aureusimines in staphylococcal gene regulation and virulence were due to an unintended mutation in saeS, which was likely selected due to elevated resistance of the mutant to environmental stresses. Thus, there is no evidence indicating that the dipeptide aureusimines play a role in sae-mediated virulence factor production or contribute to staphylococcal virulence.

  6. Sporangiospore size dimorphism is linked to virulence of Mucor circinelloides.

    Science.gov (United States)

    Li, Charles H; Cervantes, Maria; Springer, Deborah J; Boekhout, Teun; Ruiz-Vazquez, Rosa M; Torres-Martinez, Santiago R; Heitman, Joseph; Lee, Soo Chan

    2011-06-01

    Mucor circinelloides is a zygomycete fungus and an emerging opportunistic pathogen in immunocompromised patients, especially transplant recipients and in some cases otherwise healthy individuals. We have discovered a novel example of size dimorphism linked to virulence. M. circinelloides is a heterothallic fungus: (+) sex allele encodes SexP and (-) sex allele SexM, both of which are HMG domain protein sex determinants. M. circinelloides f. lusitanicus (Mcl) (-) mating type isolates produce larger asexual sporangiospores that are more virulent in the wax moth host compared to (+) isolates that produce smaller less virulent sporangiospores. The larger sporangiospores germinate inside and lyse macrophages, whereas the smaller sporangiospores do not. sexMΔ mutants are sterile and still produce larger virulent sporangiospores, suggesting that either the sex locus is not involved in virulence/spore size or the sexP allele plays an inhibitory role. Phylogenetic analysis supports that at least three extant subspecies populate the M. circinelloides complex in nature: Mcl, M. circinelloides f. griseocyanus, and M. circinelloides f. circinelloides (Mcc). Mcc was found to be more prevalent among clinical Mucor isolates, and more virulent than Mcl in a diabetic murine model in contrast to the wax moth host. The M. circinelloides sex locus encodes an HMG domain protein (SexP for plus and SexM for minus mating types) flanked by genes encoding triose phosphate transporter (TPT) and RNA helicase homologs. The borders of the sex locus between the three subspecies differ: the Mcg sex locus includes the promoters of both the TPT and the RNA helicase genes, whereas the Mcl and Mcc sex locus includes only the TPT gene promoter. Mating between subspecies was restricted compared to mating within subspecies. These findings demonstrate that spore size dimorphism is linked to virulence of M. circinelloides species and that plasticity of the sex locus and adaptations in pathogenicity have

  7. Aureusimines in Staphylococcus aureus are not involved in virulence.

    Directory of Open Access Journals (Sweden)

    Fei Sun

    2010-12-01

    Full Text Available Recently, dipeptide aureusimines were reported to activate expression of staphylococcal virulence genes, such as alpha-hemolysin, and increase S. aureus virulence. Surprisingly, most of the virulence genes affected by aureusimines form part of the regulon of the SaeRS two component system (TCS, raising the possibility that SaeRS might be directly or indirectly involved in the aureusimine-dependent signaling process.Using HPLC analyses, we confirmed that a transposon mutant of ausA, the gene encoding the aureusimine dipeptide synthesis enzyme, does not produce dipeptides. However, the transposon mutant showed normal hemolysis activity and alpha-hemolysin/SaeP production. Furthermore, the P1 promoter of the sae operon, one of the targets of the SaeRS TCS, showed normal transcription activity. Moreover, in contrast to the original report, the ausA transposon mutant did not exhibit attenuated virulence in an animal infection model. DNA sequencing revealed that the ausA deletion mutant used in the original study has an 83 nt-duplication in saeS. Hemolysis activity of the original mutant was restored by a plasmid carrying the sae operon. A mutant of the sae operon showed elevated resistance to chloramphenicol and erythromycin, two antibiotics widely used during staphylococcal mutagenesis. At 43°C in the presence of erythromycin and aeration, the conditions typically employed for staphylococcal mutagenesis, an saeR transposon mutant grew much faster than a control mutant and the saeR mutant was highly enriched in a mixed culture experiment.Our results show that the previously reported roles of aureusimines in staphylococcal gene regulation and virulence were due to an unintended mutation in saeS, which was likely selected due to elevated resistance of the mutant to environmental stresses. Thus, there is no evidence indicating that the dipeptide aureusimines play a role in sae-mediated virulence factor production or contribute to staphylococcal

  8. Genome-wide analysis of gene expression and protein secretion of Babesia canis during virulent infection identifies potential pathogenicity factors.

    Science.gov (United States)

    Eichenberger, Ramon M; Ramakrishnan, Chandra; Russo, Giancarlo; Deplazes, Peter; Hehl, Adrian B

    2017-06-13

    Infections of dogs with virulent strains of Babesia canis are characterized by rapid onset and high mortality, comparable to complicated human malaria. As in other apicomplexan parasites, most Babesia virulence factors responsible for survival and pathogenicity are secreted to the host cell surface and beyond where they remodel and biochemically modify the infected cell interacting with host proteins in a very specific manner. Here, we investigated factors secreted by B. canis during acute infections in dogs and report on in silico predictions and experimental analysis of the parasite's exportome. As a backdrop, we generated a fully annotated B. canis genome sequence of a virulent Hungarian field isolate (strain BcH-CHIPZ) underpinned by extensive genome-wide RNA-seq analysis. We find evidence for conserved factors in apicomplexan hemoparasites involved in immune-evasion (e.g. VESA-protein family), proteins secreted across the iRBC membrane into the host bloodstream (e.g. SA- and Bc28 protein families), potential moonlighting proteins (e.g. profilin and histones), and uncharacterized antigens present during acute crisis in dogs. The combined data provides a first predicted and partially validated set of potential virulence factors exported during fatal infections, which can be exploited for urgently needed innovative intervention strategies aimed at facilitating diagnosis and management of canine babesiosis.

  9. Trait Emotional Intelligence and Personality: Gender-Invariant Linkages Across Different Measures of the Big Five.

    Science.gov (United States)

    Siegling, Alexander B; Furnham, Adrian; Petrides, K V

    2015-02-01

    This study investigated if the linkages between trait emotional intelligence (trait EI) and the Five-Factor Model of personality were invariant between men and women. Five English-speaking samples ( N = 307-685) of mostly undergraduate students each completed a different measure of the Big Five personality traits and either the full form or short form of the Trait Emotional Intelligence Questionnaire (TEIQue). Across samples, models predicting global TEIQue scores from the Big Five were invariant between genders, with Neuroticism and Extraversion being the strongest trait EI correlates, followed by Conscientiousness, Agreeableness, and Openness. However, there was some evidence indicating that the gender-specific contributions of the Big Five to trait EI vary depending on the personality measure used, being more consistent for women. Discussion focuses on the validity of the TEIQue as a measure of trait EI and its psychometric properties, more generally.

  10. Elevated Autism Spectrum Disorder Traits in Young Children with OCD.

    Science.gov (United States)

    Stewart, Elyse; Cancilliere, Mary Kathryn; Freeman, Jennifer; Wellen, Brianna; Garcia, Abbe; Sapyta, Jeffrey; Franklin, Martin

    2016-12-01

    Studies have shown a high prevalence of autistic spectrum traits in both children and adults with psychiatric disorders; however the prevalence rate has not yet been investigated in young children with OCD. The aim of the current study was to (1) determine whether ASD traits indicated by the Social Communication Questionnaire (SCQ) and the Social Responsiveness Scale (SRS) were elevated in young children with OCD who do not have a specific ASD diagnosis and (2) determine if ASD traits were associated with OCD severity. Participants (N = 127) were children ages 5-8 years enrolled in the pediatric obsessive-compulsive disorder treatment study for young children (POTS Jr.). Results indicated that the SRS showed elevated autistic traits in the sample and was associated with OCD severity whereas the SCQ did not indicate heightened ASD symptoms. Implications of these results are discussed.

  11. Quantitative Trait Loci for Fertility Traits in Finnish Ayrshire Cattle

    DEFF Research Database (Denmark)

    Schulman, Nina F; Sahana, Goutam; Lund, Mogens S

    2008-01-01

    A whole genome scan was carried out to detect quantitative trait loci (QTL) for fertility traits in Finnish Ayrshire cattle. The mapping population consisted of 12 bulls and 493 sons. Estimated breeding values for days open, fertility treatments, maternal calf mortality and paternal non-return rate...... combinations, which were observed significant in the regression method. Twenty-two chromosome-wise significant QTL were detected. Several of the detected QTL areas were overlapping with milk production QTL previously identified in the same population. Multi-trait QTL analyses were carried out to test...... if these effects were due to a pleiotropic QTL affecting fertility and milk yield traits or to linked QTL causing the effects. This distinction could only be made with confidence on BTA1 where a QTL affecting milk yield is linked to a pleiotropic QTL affecting days open and fertility treatments...

  12. Quantitative trait loci mapping for stomatal traits in interspecific ...

    Indian Academy of Sciences (India)

    M. Sumathi

    2018-02-23

    Feb 23, 2018 ... Journal of Genetics, Vol. ... QTL analysis was carried out to identify the chromosomal regions affecting ... Keywords. linkage map; quantitative trait loci; stomata; stress ..... of India for providing financial support for the project.

  13. Empirical support for optimal virulence in a castrating parasite.

    Directory of Open Access Journals (Sweden)

    Knut Helge Jensen

    2006-07-01

    Full Text Available The trade-off hypothesis for the evolution of virulence predicts that parasite transmission stage production and host exploitation are balanced such that lifetime transmission success (LTS is maximised. However, the experimental evidence for this prediction is weak, mainly because LTS, which indicates parasite fitness, has been difficult to measure. For castrating parasites, this simple model has been modified to take into account that parasites convert host reproductive resources into transmission stages. Parasites that kill the host too early will hardly benefit from these resources, while postponing the killing of the host results in diminished returns. As predicted from optimality models, a parasite inducing castration should therefore castrate early, but show intermediate levels of virulence, where virulence is measured as time to host killing. We studied virulence in an experimental system where a bacterial parasite castrates its host and produces spores that are not released until after host death. This permits estimating the LTS of the parasite, which can then be related to its virulence. We exposed replicate individual Daphnia magna (Crustacea of one host clone to the same amount of bacterial spores and followed individuals until their death. We found that the parasite shows strong variation in the time to kill its host and that transmission stage production peaks at an intermediate level of virulence. A further experiment tested for the genetic basis of variation in virulence by comparing survival curves of daphniids infected with parasite spores obtained from early killing versus late killing infections. Hosts infected with early killer spores had a significantly higher death rate as compared to those infected with late killers, indicating that variation in time to death was at least in part caused by genetic differences among parasites. We speculate that the clear peak in lifetime reproductive success at intermediate killing times

  14. Antimicrobial resistance and virulence genes in enterococci from wild game meat in Spain.

    Science.gov (United States)

    Guerrero-Ramos, Emilia; Cordero, Jorge; Molina-González, Diana; Poeta, Patrícia; Igrejas, Gilberto; Alonso-Calleja, Carlos; Capita, Rosa

    2016-02-01

    A total of 55 enterococci (45 Enterococcus faecium, 7 Enterococcus faecalis, and three Enterococcus durans) isolated from the meat of wild game animals (roe deer, boar, rabbit, pheasant, and pigeon) in North-Western Spain were tested for susceptibility to 14 antimicrobials by the disc diffusion method. All strains showed a multi-resistant phenotype (resistance to between three and 10 antimicrobials). The strains exhibited high percentages of resistance to erythromycin (89.1%), tetracycline (67.3%), ciprofloxacin (92.7%), nitrofurantoin (67.3%), and quinupristin-dalfopristin (81.8%). The lowest values (9.1%) were observed for high-level resistance to gentamicin, kanamycin, and streptomycin. The average number of resistances per strain was 5.8 for E. faecium isolates, 7.9 for E. faecalis, and 5.7 for E. durans. Genes encoding antimicrobial resistance and virulence were studied by polymerase chain reaction. A total of 15 (57.7%) of the 26 vancomycin-resistant isolates harboured the vanA gene. Other resistance genes detected included vanB, erm(B) and/or erm(C), tet(L) and/or tet(M), acc(6')-aph(2″), and aph(3')-IIIa in strains resistant to vancomycin, erythromycin, tetracycline, gentamicin, and kanamycin, respectively. Specific genes of the Tn5397 transposon were detected in 54.8% of the tet(M)-positive enterococci. Nine virulence factors (gelE, agg, ace, cpd, frs, esp, hyl, efaAfs and efaAfm) were studied. All virulence genes, with the exception of the frs gene, were found to be present in the enterococcal isolates. At least one virulence gene was detected in 20.0% of E. faecium, 71.4% of E. faecalis and 33.3% of E. durans isolates, with ace and cpd being the most frequently detected genes (6 isolates each). This suggests that wild game meat might play a role in the spreading through the food chain of enterococci with antimicrobial resistance and virulence determinants to humans. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Screening of virulence genes in Staphylococcus aureus isolates from rabbits

    Directory of Open Access Journals (Sweden)

    David Viana Martín

    2015-09-01

    Full Text Available Staphylococcus aureus is a versatile pathogen able to cause disease in both humans and animals. In rabbits, this bacterium infects animals of different ages, producing several purulent lesions. The ability of S. aureus to cause disease depends on a combination of virulence factors. The aim of this study was therefore to investigate the distribution of bacterial virulence determinants in 69 S. aureus isolates from rabbits. Some virulence factors (7 adhesins, 1 toxin and 1 protease were positive in all rabbit S. aureus isolates analysed, while others (1 adhesin and 10 toxins were always negative. The remaining virulence factors were more variable among isolates. An association between genotype and the different profiles of virulence factors was observed, but not with the type of lesion (P<0.05. One strain of each genotype was further analysed by multilocus sequence typing, generating ST121, ST96 and ST2951, determining a greater number of enterotoxins in ST121 isolates compared to ST96 and ST2951 isolates, which could justify the different pathogenicity between strains. 

  16. Genetic Regulation of Virulence and Antibiotic Resistance in Acinetobacter baumannii

    Science.gov (United States)

    Kröger, Carsten; Kary, Stefani C.; Schauer, Kristina; Cameron, Andrew D. S.

    2016-01-01

    Multidrug resistant microorganisms are forecast to become the single biggest challenge to medical care in the 21st century. Over the last decades, members of the genus Acinetobacter have emerged as bacterial opportunistic pathogens, in particular as challenging nosocomial pathogens because of the rapid evolution of antimicrobial resistances. Although we lack fundamental biological insight into virulence mechanisms, an increasing number of researchers are working to identify virulence factors and to study antibiotic resistance. Here, we review current knowledge regarding the regulation of virulence genes and antibiotic resistance in Acinetobacter baumannii. A survey of the two-component systems AdeRS, BaeSR, GacSA and PmrAB explains how each contributes to antibiotic resistance and virulence gene expression, while BfmRS regulates cell envelope structures important for pathogen persistence. A. baumannii uses the transcription factors Fur and Zur to sense iron or zinc depletion and upregulate genes for metal scavenging as a critical survival tool in an animal host. Quorum sensing, nucleoid-associated proteins, and non-classical transcription factors such as AtfA and small regulatory RNAs are discussed in the context of virulence and antibiotic resistance. PMID:28036056

  17. Molecular determinants of Ebola virus virulence in mice.

    Directory of Open Access Journals (Sweden)

    Hideki Ebihara

    2006-07-01

    Full Text Available Zaire ebolavirus (ZEBOV causes severe hemorrhagic fever in humans and nonhuman primates, with fatality rates in humans of up to 90%. The molecular basis for the extreme virulence of ZEBOV remains elusive. While adult mice resist ZEBOV infection, the Mayinga strain of the virus has been adapted to cause lethal infection in these animals. To understand the pathogenesis underlying the extreme virulence of Ebola virus (EBOV, here we identified the mutations responsible for the acquisition of the high virulence of the adapted Mayinga strain in mice, by using reverse genetics. We found that mutations in viral protein 24 and in the nucleoprotein were primarily responsible for the acquisition of high virulence. Moreover, the role of these proteins in virulence correlated with their ability to evade type I interferon-stimulated antiviral responses. These findings suggest a critical role for overcoming the interferon-induced antiviral state in the pathogenicity of EBOV and offer new insights into the pathogenesis of EBOV infection.

  18. The Role of Antibiotics in Modulating Virulence in Staphylococcus aureus.

    Science.gov (United States)

    Hodille, Elisabeth; Rose, Warren; Diep, Binh An; Goutelle, Sylvain; Lina, Gerard; Dumitrescu, Oana

    2017-10-01

    Staphylococcus aureus is often involved in severe infections, in which the effects of bacterial virulence factors have great importance. Antistaphylococcal regimens should take into account the different effects of antibacterial agents on the expression of virulence factors and on the host's immune response. A PubMed literature search was performed to select relevant articles on the effects of antibiotics on staphylococcal toxin production and on the host immune response. Information was sorted according to the methods used for data acquisition (bacterial strains, growth models, and antibiotic concentrations) and the assays used for readout generation. The reported mechanisms underlying S. aureus virulence modulation by antibiotics were reviewed. The relevance of in vitro observations is discussed in relation to animal model data and to clinical evidence extracted from case reports and recommendations on the management of toxin-related staphylococcal diseases. Most in vitro data point to a decreased level of virulence expression upon treatment with ribosomally active antibiotics (linezolid and clindamycin), while cell wall-active antibiotics (beta-lactams) mainly increase exotoxin production. In vivo studies confirmed the suppressive effect of clindamycin and linezolid on virulence expression, supporting their utilization as a valuable management strategy to improve patient outcomes in cases of toxin-associated staphylococcal disease. Copyright © 2017 American Society for Microbiology.

  19. OrfX, a Nucleomodulin Required for Listeria monocytogenes Virulence

    Directory of Open Access Journals (Sweden)

    Andrzej Prokop

    2017-10-01

    Full Text Available Listeria monocytogenes is a bacterial pathogen causing severe foodborne infections in humans and animals. Listeria can enter into host cells and survive and multiply therein, due to an arsenal of virulence determinants encoded in different loci on the chromosome. Several key Listeria virulence genes are clustered in Listeria pathogenicity island 1. This important locus also contains orfX (lmo0206, a gene of unknown function. Here, we found that OrfX is a small, secreted protein whose expression is positively regulated by PrfA, the major transcriptional activator of Listeria virulence genes. We provide evidence that OrfX is a virulence factor that dampens the oxidative response of infected macrophages, which contributes to intracellular survival of bacteria. OrfX is targeted to the nucleus and interacts with the regulatory protein RybP. We show that in macrophages, the expression of OrfX decreases the level of RybP, which controls cellular infection. Collectively, these data reveal that Listeria targets RybP and evades macrophage oxidative stress for efficient infection. Altogether, OrfX is after LntA, the second virulence factor acting directly in the nucleus.

  20. Quorum-sensing-regulated virulence factors in Pseudomonas aeruginosa are toxic to Lucilia sericata maggots

    DEFF Research Database (Denmark)

    Andersen, A S; Joergensen, B; Bjarnsholt, T

    2010-01-01

    Maggot debridement therapy (MDT) is widely used for debridement of chronic infected wounds; however, for wounds harbouring specific bacteria limited effect or failure of the treatment has been described. Here we studied the survival of Lucilia sericata maggots encountering Pseudomonas aeruginosa...... PAO1 in a simple assay with emphasis on the quorum-sensing (QS)-regulated virulence. The maggots were challenged with GFP-tagged P. aeruginosa wild-type (WT) PAO1 and a GFP-tagged P. aeruginosa DeltalasR rhlR (DeltaRR) QS-deficient mutant in different concentrations. Maggots were killed...

  1. Strategies for defining traits when calculating economic values for livestock breeding: a review.

    Science.gov (United States)

    Wolfová, M; Wolf, J

    2013-09-01

    The objective of the present review was (i) to survey different approaches for choosing the complex of traits for which economic values (EVs) are calculated, (ii) to call attention to the proper definition of traits and (iii) to discuss the manner and extent to which relationships among traits have been considered in the calculation of EVs. For this purpose, papers dealing with the estimation of EVs of traits in livestock were reviewed. The most important reasons for incompatibility of EVs for similar traits estimated in different countries and by different authors were found to be inconsistencies in trait definitions and in assumptions being made about relationships among traits. An important problem identified was how to choose the most appropriate criterion to characterise production or functional ability for a particular class of animals. Accordingly, the review covered the following three topics: (i) which trait(s) would best characterise the growth ability of an animal; (ii) how to define traits expressed repeatedly in subsequent reproductive cycles of breeding females and (iii) how to deal with traits that differ in average value between sexes or among animal groups. Various approaches that have been used to solve these problems were discussed. Furthermore, the manner in which diverse authors chose one or more traits from a group of alternatives for describing a specific biological potential were reviewed and commented on. The consequences of including or excluding relationships among economically important traits when estimating the EV for a specific trait were also examined. An important conclusion of the review is that, for a better comparability and interpretability of estimated EVs in the literature, it is desirable that clear and unique definitions of the traits, complete information on assumptions used in analytical models and details on inter-relationships between traits are documented. Furthermore, the method and the model used for the genetic

  2. Comparative Transcriptome Analysis Reveals Cool Virulence Factors of Ralstonia solanacearum Race 3 Biovar 2.

    Science.gov (United States)

    Meng, Fanhong; Babujee, Lavanya; Jacobs, Jonathan M; Allen, Caitilyn

    2015-01-01

    While most strains of the plant pathogenic bacterium Ralstonia solanacearum are tropical, the race 3 biovar 2 (R3bv2) subgroup attacks plants in cooler climates. To identify mechanisms underlying this trait, we compared the transcriptional profiles of R. solanacearum R3bv2 strain UW551 and tropical strain GMI1000 at 20°C and 28°C, both in culture and during tomato pathogenesis. 4.2% of the ORFs in the UW551 genome and 7.9% of the GMI1000 ORFs were differentially expressed by temperature in planta. The two strains had distinct transcriptional responses to temperature change. GMI1000 up-regulated several stress response genes at 20°C, apparently struggling to cope with plant defenses. At the cooler temperature, R3bv2 strain UW551 up-regulated a cluster encoding a mannose-fucose binding lectin, LecM; a quorum sensing-dependent protein, AidA; and a related hypothetical protein, AidC. The last two genes are absent from the GMI1000 genome. In UW551, all three genes were positively regulated by the adjacent SolI/R quorum sensing system. These temperature-responsive genes were required for full virulence in R3bv2. Mutants lacking lecM, aidA, or aidC were each significantly more reduced in virulence on tomato at 20°C than at 28°C in both a naturalistic soil soak inoculation assay and when they were inoculated directly into tomato stems. The lecM and aidC mutants also survived poorly in potato tubers at the seed tuber storage temperature of 4°C, and the lecM mutant was defective in biofilm formation in vitro. Together, these results suggest novel mechanisms, including a lectin, are involved in the unique temperate epidemiology of R3bv2.

  3. Comparative Transcriptome Analysis Reveals Cool Virulence Factors of Ralstonia solanacearum Race 3 Biovar 2.

    Directory of Open Access Journals (Sweden)

    Fanhong Meng

    Full Text Available While most strains of the plant pathogenic bacterium Ralstonia solanacearum are tropical, the race 3 biovar 2 (R3bv2 subgroup attacks plants in cooler climates. To identify mechanisms underlying this trait, we compared the transcriptional profiles of R. solanacearum R3bv2 strain UW551 and tropical strain GMI1000 at 20°C and 28°C, both in culture and during tomato pathogenesis. 4.2% of the ORFs in the UW551 genome and 7.9% of the GMI1000 ORFs were differentially expressed by temperature in planta. The two strains had distinct transcriptional responses to temperature change. GMI1000 up-regulated several stress response genes at 20°C, apparently struggling to cope with plant defenses. At the cooler temperature, R3bv2 strain UW551 up-regulated a cluster encoding a mannose-fucose binding lectin, LecM; a quorum sensing-dependent protein, AidA; and a related hypothetical protein, AidC. The last two genes are absent from the GMI1000 genome. In UW551, all three genes were positively regulated by the adjacent SolI/R quorum sensing system. These temperature-responsive genes were required for full virulence in R3bv2. Mutants lacking lecM, aidA, or aidC were each significantly more reduced in virulence on tomato at 20°C than at 28°C in both a naturalistic soil soak inoculation assay and when they were inoculated directly into tomato stems. The lecM and aidC mutants also survived poorly in potato tubers at the seed tuber storage temperature of 4°C, and the lecM mutant was defective in biofilm formation in vitro. Together, these results suggest novel mechanisms, including a lectin, are involved in the unique temperate epidemiology of R3bv2.

  4. Pyrokinin β-neuropeptide affects necrophoretic behavior in fire ants (S. invicta), and expression of β-NP in a mycoinsecticide increases its virulence.

    Science.gov (United States)

    Fan, Yanhua; Pereira, Roberto M; Kilic, Engin; Casella, George; Keyhani, Nemat O

    2012-01-01

    Fire ants are one of the world's most damaging invasive pests, with few means for their effective control. Although ecologically friendly alternatives to chemical pesticides such as the insecticidal fungus Beauveria bassiana have been suggested for the control of fire ant populations, their use has been limited due to the low virulence of the fungus and the length of time it takes to kill its target. We present a means of increasing the virulence of the fungal agent by expressing a fire ant neuropeptide. Expression of the fire ant (Solenopsis invicta) pyrokinin β-neuropeptide (β-NP) by B. bassiana increased fungal virulence six-fold towards fire ants, decreased the LT(50), but did not affect virulence towards the lepidopteran, Galleria mellonella. Intriguingly, ants killed by the β-NP expressing fungus were disrupted in the removal of dead colony members, i.e. necrophoretic behavior. Furthermore, synthetic C-terminal amidated β-NP but not the non-amidated peptide had a dramatic effect on necrophoretic behavior. These data link chemical sensing of a specific peptide to a complex social behavior. Our results also confirm a new approach to insect control in which expression of host molecules in an insect pathogen can by exploited for target specific augmentation of virulence. The minimization of the development of potential insect resistance by our approach is discussed.

  5. Automatic prediction of facial trait judgments: appearance vs. structural models.

    Directory of Open Access Journals (Sweden)

    Mario Rojas

    Full Text Available Evaluating other individuals with respect to personality characteristics plays a crucial role in human relations and it is the focus of attention for research in diverse fields such as psychology and interactive computer systems. In psychology, face perception has been recognized as a key component of this evaluation system. Multiple studies suggest that observers use face information to infer personality characteristics. Interactive computer systems are trying to take advantage of these findings and apply them to increase the natural aspect of interaction and to improve the performance of interactive computer systems. Here, we experimentally test whether the automatic prediction of facial trait judgments (e.g. dominance can be made by using the full appearance information of the face and whether a reduced representation of its structure is sufficient. We evaluate two separate approaches: a holistic representation model using the facial appearance information and a structural model constructed from the relations among facial salient points. State of the art machine learning methods are applied to a derive a facial trait judgment model from training data and b predict a facial trait value for any face. Furthermore, we address the issue of whether there are specific structural relations among facial points that predict perception of facial traits. Experimental results over a set of labeled data (9 different trait evaluations and classification rules (4 rules suggest that a prediction of perception of facial traits is learnable by both holistic and structural approaches; b the most reliable prediction of facial trait judgments is obtained by certain type of holistic descriptions of the face appearance; and c for some traits such as attractiveness and extroversion, there are relationships between specific structural features and social perceptions.

  6. The origin of endodontic Enterococcus faecalis explored by comparison of virulence factor patterns and antibiotic resistance to that of isolates from stool samples, blood cultures and food.

    Science.gov (United States)

    Vidana, R; Rashid, M U; Özenci, V; Weintraub, A; Lund, B

    2016-04-01

    To elucidate the origin of Enterococcus faecalis isolated from secondary root canal infections and the possibility for a foodborne transmission by comparing them to strains recovered from food, blood and stool regarding putative virulence factors and antibiotic susceptibility profiles, where strains from common origin were hypothesized to harbour similar characteristics. A total of 108 E. faecalis strains recovered in the county of Stockholm, Sweden, were screened using PCR for putative virulence factors esp, cylA, gelE/gelatinase-negative phenotype (ef1841/fsrC), efaA, ace and asa1. The minimum inhibitory concentration (MIC) for ampicillin, piperacillin-tazobactam, imipenem, gentamicin, vancomycin, ciprofloxacin and linezolid was determined using the agar dilution method. Next to strains from blood, the food isolates presented the highest average number of virulence determinants and were frequently enriched with asa1 coding for aggregation substance. None of the endodontic strains carried cylA, and the gelatinase-negative phenotype caused by a deletion dominated the group. Altogether, the most prevalent genes were gelE, efaA and ace, and a combination of them was equally present in approximately 80% of the strains from food, stool and root canals in comparison with 43.3% of the blood isolates. High-level resistance to ciprofloxacin and gentamicin was observed in 30% of the blood isolates, whereas the isolates from other origins, with single exceptions, were susceptible to all tested antibiotics. Evidence for a foodborne transmission, explaining the high reported prevalence of E. faecalis in root filled teeth, could not be determined based on the similarities in virulence factor patterns and antibiotic su