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Sample records for bacterial groups implications

  1. Comparative genomics of the bacterial genus Streptococcus illuminates evolutionary implications of species groups.

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    Xiao-Yang Gao

    Full Text Available Members of the genus Streptococcus within the phylum Firmicutes are among the most diverse and significant zoonotic pathogens. This genus has gone through considerable taxonomic revision due to increasing improvements of chemotaxonomic approaches, DNA hybridization and 16S rRNA gene sequencing. It is proposed to place the majority of streptococci into "species groups". However, the evolutionary implications of species groups are not clear presently. We use comparative genomic approaches to yield a better understanding of the evolution of Streptococcus through genome dynamics, population structure, phylogenies and virulence factor distribution of species groups. Genome dynamics analyses indicate that the pan-genome size increases with the addition of newly sequenced strains, while the core genome size decreases with sequential addition at the genus level and species group level. Population structure analysis reveals two distinct lineages, one including Pyogenic, Bovis, Mutans and Salivarius groups, and the other including Mitis, Anginosus and Unknown groups. Phylogenetic dendrograms show that species within the same species group cluster together, and infer two main clades in accordance with population structure analysis. Distribution of streptococcal virulence factors has no obvious patterns among the species groups; however, the evolution of some common virulence factors is congruous with the evolution of species groups, according to phylogenetic inference. We suggest that the proposed streptococcal species groups are reasonable from the viewpoints of comparative genomics; evolution of the genus is congruent with the individual evolutionary trajectories of different species groups.

  2. Mirror neurons: their implications for group psychotherapy.

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    Schermer, Victor L

    2010-10-01

    Recently discovered mirror neurons in the motor cortex of the brain register the actions and intentions of both the organism and others in the environment. As such, they may play a significant role in social behavior and groups. This paper considers the potential implications of mirror neurons and related neural networks for group therapists, proposing that mirror neurons and mirror systems provide "hard-wired" support for the group therapist's belief in the centrality of relationships in the treatment process and exploring their value in accounting for group-as-a-whole phenomena. Mirror neurons further confirm the holistic, social nature of perception, action, and intention as distinct from a stimulus-response behaviorism. The implications of mirror neurons and mirroring processes for the group therapist role, interventions, and training are also discussed.

  3. Semen analysis in chronic bacterial prostatitis: diagnostic and therapeutic implications

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    Magri, Vittorio; Wagenlehner, Florian M E; Montanari, Emanuele; Marras, Emanuela; Orlandi, Viviana; Restelli, Antonella; Torresani, Erminio; Naber, Kurt G; Perletti, Gianpaolo

    2009-01-01

    The significance and diagnostic value of semen analysis in chronic bacterial prostatitis has been extensively debated and remains controversial. To investigate the diagnostic relevance of semen culture in the bacteriological workup of prostatitis patients, we retrospectively analyzed a clinical database of 696 symptomatic patients. All patients were routinely subjected to a four-glass test, followed by semen culture and analysis. This allowed to dissect from the database three different diagnostic scenarios, and to compare the 'two-glass' pre-/post- massage test and the standard 'four-glass' test with a 'five-glass' test (four-glass plus post-VB3 semen culture). The 'five-glass' test showed 3.6- or 6.5-fold increases in relative sensitivity and lesser reductions (−13.2% or −14.7%) in relative specificity for traditional uropathogens (TUs) compared with the four-glass or two-glass test, respectively. The area under the ROC curve and Jouden's index were increased, whereas positive and negative likelihood ratios were lower than comparators, indicating that the 'five-glass' assay may be superior in confirming the negative outcome of both standard tests. The five-, four-, and two-glass tests detected TUs (Enterobacteriaceae, Enterococci, etc.) in 120, 33, and 20 patients and unusual pathogens (Streptococci, other Gram-positive species, Mycoplasmata, and others) in 130, 56, and 45 patients, respectively. When patients were subjected to pharmacological treatment, including a combination of a fluoroquinolone and a macrolide, no differences in eradication rates were observed between groups diagnosed with different tests, irrespective of pathogen category. Eradication was associated with long-term sign/symptom remission; no significant intergroup differences in sign/symptom scores were observed throughout a 24-month off-therapy follow-up period. In conclusion, our data support the usefulness of semen analysis in the diagnostic workup of prostatitis patients when this

  4. A Small Group Activity About Bacterial Regulation And Complementation

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    Susan M. Merkel

    2010-11-01

    Full Text Available As teachers, we well understand the need for activities that help develop critical-thinking skills in microbiology. In our experience, one concept that students have difficulty understanding is transcriptional regulation of bacterial genes. To help with this, we developed and evaluated a paper-based activity to help students understand and apply the concepts of bacterial transcriptional regulation. While we don't identify it as such, we use a complementation experiment to assess student understanding of how regulation changes when new DNA is introduced. In Part 1 of this activity, students complete an open book, take-home assignment that asks them to define common terminology related to regulation, and draw the regulatory components of different scenarios involving positive and negative regulation. In Part 2, students work in small groups of 3-4 to depict the regulatory components for a different scenario. They are asked to explain the results of a complementation experiment based on this scenario. They then predict the results of a slightly different experiment. Students who completed the Regulation Activity did significantly better on post-test questions related to regulation, compared to pre-test questions.

  5. [Main bacterial groups in banana soil under rotated and continuous cropping].

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    Ouyang, Xian; Ruan, Xiao-Lei; Wu, Chao; Bai, Ting-Ting; Li, Hua-Ping

    2011-06-01

    Banana wilt is the main disease in banana production, while banana-leek rotation can effectively control the occurrence of the disease. In order to understand the variations of soil bacterial groups under banana-leek rotation and banana continuous cropping, soil samples under these two cropping systems were collected to extract crude DNA, and the bacterial 16S rDNA in V3 region was amplified by PCR. The PCR products were then separated by DGGE, and the main different bands were sequenced and compared with the records of NCBI to identify the germs. Under banana-leek rotation, soil bacterial diversity was richer, and the main bacterial groups were Bacteroidetes, Proteobacteria, Actinobacteria, Chloroflexi, and Acidobacteria; while under banana continuous cropping, the soil bacterial diversity was somewhat decreased, and the main bacterial groups were Firmicutes, Proteobacteria, Actinobacteria, and Chloroflexi.

  6. Evolving trends in Streptococcus pneumoniae resistance: implications for therapy of community-acquired bacterial pneumonia.

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    Jones, Ronald N; Jacobs, Michael R; Sader, Helio S

    2010-09-01

    Pneumonia is a major infectious disease associated with significant morbidity, mortality and utilisation of healthcare resources. Streptococcus pneumoniae is the predominant pathogen in community-acquired pneumonia (CAP), accounting for 20-60% of bacterial cases. Emergence of multidrug-resistant S. pneumoniae has become a significant problem in the management of CAP. Although pneumococcal conjugate vaccine usage in children has led to significant decreases in morbidity and mortality due to S. pneumoniae in all age groups, disease management has been further complicated by the unexpected increase in resistant serotypes, such as 19A, in some regions. Until rapid and accurate diagnostic tests become available, initial treatment of CAP will remain empirical. Thus, selection of appropriate antimicrobial therapy for CAP must be based on prediction of the most likely pathogens and their local antimicrobial susceptibility patterns. This article reviews information on antimicrobial resistance patterns amongst S. pneumoniae and implications for managing CAP.

  7. Semiquantitative Bacterial Observations With Group B Streptococcal Vulvovaginitis

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    G. R. G. Monif

    1999-01-01

    Full Text Available Objective: Group B streptococcal (GBS vulvovaginitis is a poorly-delineated clinical entity. The purpose of this study is to report semiquantitative data from four cases of GBS vulvovaginitis and to comment on their significance in terms of the in vitro inhibitory capabilities of GBS.

  8. Bacterial group II introns in a deep-sea hydrothermal vent environment.

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    Podar, Mircea; Mullineaux, Lauren; Huang, Hon-Ren; Perlman, Philip S; Sogin, Mitchell L

    2002-12-01

    Group II introns are catalytic RNAs and mobile retrotransposable elements known to be present in the genomes of some nonmarine bacteria and eukaryotic organelles. Here we report the discovery of group II introns in a bacterial mat sample collected from a deep-sea hydrothermal vent near 9 degrees N on the East Pacific Rise. One of the introns was shown to self-splice in vitro. This is the first example of marine bacterial introns from molecular population structure studies of microorganisms that live in the proximity of hydrothermal vents. These types of mobile genetic elements may prove useful in improving our understanding of bacterial genome evolution and may serve as valuable markers in comparative studies of bacterial communities.

  9. Protein oxidation implicated as the primary determinant of bacterial radioresistance.

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    Michael J Daly

    2007-04-01

    Full Text Available In the hierarchy of cellular targets damaged by ionizing radiation (IR, classical models of radiation toxicity place DNA at the top. Yet, many prokaryotes are killed by doses of IR that cause little DNA damage. Here we have probed the nature of Mn-facilitated IR resistance in Deinococcus radiodurans, which together with other extremely IR-resistant bacteria have high intracellular Mn/Fe concentration ratios compared to IR-sensitive bacteria. For in vitro and in vivo irradiation, we demonstrate a mechanistic link between Mn(II ions and protection of proteins from oxidative modifications that introduce carbonyl groups. Conditions that inhibited Mn accumulation or Mn redox cycling rendered D. radiodurans radiation sensitive and highly susceptible to protein oxidation. X-ray fluorescence microprobe analysis showed that Mn is globally distributed in D. radiodurans, but Fe is sequestered in a region between dividing cells. For a group of phylogenetically diverse IR-resistant and IR-sensitive wild-type bacteria, our findings support the idea that the degree of resistance is determined by the level of oxidative protein damage caused during irradiation. We present the case that protein, rather than DNA, is the principal target of the biological action of IR in sensitive bacteria, and extreme resistance in Mn-accumulating bacteria is based on protein protection.

  10. Comparison of Hemagglutination and Hemolytic Activity of Various Bacterial Clinical Isolates Against Different Human Blood Groups

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    HRV, Rajkumar; Devaki, Ramakrishna

    2016-01-01

    Among the various pathogenic determinants shown by microorganisms hemagglutination and hemolysin production assume greater significance in terms of laboratory identification. This study evaluated the hemagglutination and hemolytic activity of various bacterial isolates against different blood groups. One hundred and fifty bacterial strains, isolated from clinical specimens like urine, pus, blood, and other body fluids were tested for their hemagglutinating and hemolytic activity against human A, B, AB, and O group red blood cells. Among the 150 isolates 81 were Escherichia coli, 18 were Klebsiella pneumoniae, 19 were Pseudomonas aeruginosa, 10 were Pseudomonas spp, six were Proteus mirabilis, and the rest 16 were Staphylococcus aureus. Nearly 85% of the isolates agglutinated A group cells followed by B and AB group (59.3% and 60.6% respectively). Least number of isolates agglutinated O group cells (38.0%). When the hemolytic activity was tested, out of these 150 isolates 79 (52.6%) hemolyzed A group cells, 61 (40.6%) hemolyzed AB group cells, 46 (30.6%) hemolyzed B group cells, and 57 (38.6%) isolates hemolyzed O group cells. Forty-six percent of the isolates exhibited both hemagglutinating and hemolytic property against A group cells, followed by B and AB group cells (28.6% and 21.3% respectively). Least number of isolates i.e., 32 (21.3%) showed both the properties against O group cells. The isolates showed wide variation in their hemagglutination and hemolytic properties against different combinations of human blood group cells. The study highlights the importance of selection of the type of cells especially when human RBCs are used for studying the hemagglutination and hemolytic activity of bacterial isolates because these two properties are considered as characteristic of pathogenic strains. PMID:27014523

  11. Identification of the serotypes of bacterial meningitis agents; implication for vaccine usage.

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    Mohammad Mehdi Attarpour-Yazdi

    2014-08-01

    Full Text Available Bacterial meningitis is one of the most serious infections and should be treated as emergency. As it has significant morbidity and mortality throughout the world, every country should have precise information regarding the etiological agents of disease and populations at risk to design public health prevention strategy. In the present study in addition of evaluation of common etiological agents (Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae in bacterial meningitis cases, we sero-grouped or serotyped the obtained agents in order to predict the usefulness of existing vaccines against bacterial meningitis.Cerebrospinal fluid of 182 suspected meningitis patients were collected, from which 114 cases were approved by biochemical, microbiological and molecular tests as bacterial meningitis. The isolated bacteria were serogrouped or serotyped to determine the dominant serotypes.Streptococcus pneumoniae accounted for 36%, Haemophilus influenza for 26% and Neisseria meningitidis for 14% of cases. From 13 serogroups of N. meningitides the most frequent serogroups, were meningococcus group B (51%, C(24% A (18%, Z(2%, W135 (1% and 3% was not identified. In H. influenzae group only serotype b (100% have been identified and in pneumococcal meningitis the most common serotype among our cases were 18C (44% followed by14 (17%, 19A (13%, 6A (9%, 7F (4%, 4(3%, 3 (3%, 9V (2%, 8 (2%, 23f (2%, 5 (1%.Since there is no nationwide mass immunization program for common agents of bacterial meningitis in Iran, the result of this study can be used to improve the existing vaccines to cover the detected serotypes and consequently reduce the incidence of bacterial meningitis.

  12. Implications of malnutrition and diagnosis-related groups (DRGs).

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    Delhey, D M; Anderson, E J; Laramee, S H

    1989-10-01

    The implications of malnutrition on the Medicare Prospective Payment System of diagnosis-related groups (DRGs) were examined in 185 Medicare patients, aged 65 to 69 years, admitted to an acute-care tertiary hospital. Upon admission, patients were classified as malnourished if they were below the acceptable level in at least two of four parameters: serum albumin concentration, total lymphocyte count, percent ideal body weight, and percent weight loss. On the basis of that criterion, 8.6% (no. = 16) of the 185 patients were classified as malnourished. Although patients were classified as malnourished, malnutrition was among several comorbidity and complication (CC) factors, and, therefore, coding for malnutrition in any of these cases would not have increased hospital reimbursement. If malnutrition had been the only CC factor, hospital reimbursement would have been enhanced.

  13. Diel-scale temporal dynamics recorded for bacterial groups in Namib Desert soil

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    Gunnigle, Eoin; Frossard, Aline; Ramond, Jean-Baptiste; Guerrero, Leandro; Seely, Mary; Cowan, Don A.

    2017-01-01

    Microbes in hot desert soil partake in core ecosystem processes e.g., biogeochemical cycling of carbon. Nevertheless, there is still a fundamental lack of insights regarding short-term (i.e., over a 24-hour [diel] cycle) microbial responses to highly fluctuating microenvironmental parameters like temperature and humidity. To address this, we employed T-RFLP fingerprinting and 454 pyrosequencing of 16S rRNA-derived cDNA to characterize potentially active bacteria in Namib Desert soil over multiple diel cycles. Strikingly, we found that significant shifts in active bacterial groups could occur over a single 24-hour period. For instance, members of the predominant Actinobacteria phyla exhibited a significant reduction in relative activity from morning to night, whereas many Proteobacterial groups displayed an opposite trend. Contrary to our leading hypothesis, environmental parameters could only account for 10.5% of the recorded total variation. Potential biotic associations shown through co-occurrence networks indicated that non-random inter- and intra-phyla associations were ‘time-of-day-dependent’ which may constitute a key feature of this system. Notably, many cyanobacterial groups were positioned outside and/or between highly interconnected bacterial associations (modules); possibly acting as inter-module ‘hubs’ orchestrating interactions between important functional consortia. Overall, these results provide empirical evidence that bacterial communities in hot desert soils exhibit complex and diel-dependent inter-community associations. PMID:28071697

  14. Diel-scale temporal dynamics recorded for bacterial groups in Namib Desert soil

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    Gunnigle, Eoin; Frossard, Aline; Ramond, Jean-Baptiste; Guerrero, Leandro; Seely, Mary; Cowan, Don A.

    2017-01-01

    Microbes in hot desert soil partake in core ecosystem processes e.g., biogeochemical cycling of carbon. Nevertheless, there is still a fundamental lack of insights regarding short-term (i.e., over a 24-hour [diel] cycle) microbial responses to highly fluctuating microenvironmental parameters like temperature and humidity. To address this, we employed T-RFLP fingerprinting and 454 pyrosequencing of 16S rRNA-derived cDNA to characterize potentially active bacteria in Namib Desert soil over multiple diel cycles. Strikingly, we found that significant shifts in active bacterial groups could occur over a single 24-hour period. For instance, members of the predominant Actinobacteria phyla exhibited a significant reduction in relative activity from morning to night, whereas many Proteobacterial groups displayed an opposite trend. Contrary to our leading hypothesis, environmental parameters could only account for 10.5% of the recorded total variation. Potential biotic associations shown through co-occurrence networks indicated that non-random inter- and intra-phyla associations were ‘time-of-day-dependent’ which may constitute a key feature of this system. Notably, many cyanobacterial groups were positioned outside and/or between highly interconnected bacterial associations (modules); possibly acting as inter-module ‘hubs’ orchestrating interactions between important functional consortia. Overall, these results provide empirical evidence that bacterial communities in hot desert soils exhibit complex and diel-dependent inter-community associations.

  15. Characterization of the vaginal microbiota among sexual risk behavior groups of women with bacterial vaginosis.

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    Christina A Muzny

    Full Text Available BACKGROUND: The pathogenesis of bacterial vaginosis (BV remains elusive. BV may be more common among women who have sex with women (WSW. The objective of this study was to use 454 pyrosequencing to investigate the vaginal microbiome of WSW, women who have sex with women and men (WSWM, and women who have sex with men (WSM with BV to determine if there are differences in organism composition between groups that may inform new hypotheses regarding the pathogenesis of BV. METHODS: Vaginal swab specimens from eligible women with BV at the Mississippi State Department of Health STD Clinic were used. After DNA extraction, 454 pyrosequencing of PCR-amplified 16S rRNA gene sequences was performed. Sequence data was classified using the Ribosomal Database Program classifer. Complete linkage clustering analysis was performed to compare bacterial community composition among samples. Differences in operational taxonomic units with an abundance of ≥ 2% between risk behavior groups were determined. Alpha and beta diversity were measured using Shannon's Index implemented in QIIME and Unifrac analysis, respectively. RESULTS: 33 WSW, 35 WSWM, and 44 WSM were included. The vaginal bacterial communities of all women clustered into four taxonomic groups with the dominant taxonomic group in each being Lactobacillus, Lachnospiraceae, Prevotella, and Sneathia. Regarding differences in organism composition between risk behavior groups, the abundance of Atopobium (relative ratio (RR=0.24; 95%CI 0.11-0.54 and Parvimonas (RR=0.33; 95%CI 0.11-0.93 were significantly lower in WSW than WSM, the abundance of Prevotella was significantly higher in WSW than WSWM (RR=1.77; 95%CI 1.10-2.86, and the abundance of Atopobium (RR=0.41; 95%CI 0.18-0.88 was significantly lower in WSWM than WSM. Overall, WSM had the highest diversity of bacterial taxa. CONCLUSION: The microbiology of BV among women in different risk behavior groups is heterogeneous. WSM in this study had the highest

  16. Nanoparticles Formed from Bacterial Oxyanion Reduction of Toxic Group 15 and Group 16 Metalloids

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    Pearce, Carolyn I.; Baesman, Shaun M.; Switzer Blum, Jodi; Fellowes, Jonathan W.; Oremland, Ronald S.

    2012-03-01

    Environmental Significance of Group 15 and 16 Toxic Metalloids Selenium, tellurium, and arsenic are present naturally in aquatic and terrestrial environments and share many similar biogeochemical characteristics. These elements are released into the environment through the weathering and decomposition of minerals contained within a variety of lithologies, with slow release rates resulting in low environmental concentrations. Selenium, tellurium, and arsenic occur in several oxidation states as oxyanions (e.g., selenate [SeO4 2], selenite [SeO3 2], tellurate [TeO4 2], tellurite [TeO3 2], arsenate [HAsO4 2], and arsenite [HAsO3 2]) in their native elemental states [e.g., Se(0), Te(0)] or in their most reduced states as selenide (-II) and telluride (-II) or arsenide/arsines (-III). These elements can be methylated through microbial activity to form compounds such as dimethylselenide (Ehrlich, 2002; Masscheleyn, et al., 1990), dimethyltelluride (Basnayake, et al., 2001; Fleming and Alexander, 1972), and methylarsonous acid (Dopp, et al., 2004) as well as a variety of toxic methylated arsine gases (Yuan, et al., 2008). These elements are also found as analogues of sulfurous proteins such as selenocysteine and selenomethionine (Bock, et al., 1991; Jones, et al., 1979; Stolz, et al., 2006; Zannoni, et al., 2008), tellurocysteine, telluromethionine (Zannoni, et al., 2008), and the arsenic-containing amino acid, arsenomethionine (Dembitsky and Levitsky, 2004).

  17. Group A Streptococcus exploits human plasminogen for bacterial translocation across epithelial barrier via tricellular tight junctions

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    Sumitomo, Tomoko; Nakata, Masanobu; Higashino, Miharu; Yamaguchi, Masaya; Kawabata, Shigetada

    2016-01-01

    Group A Streptococcus (GAS) is a human-specific pathogen responsible for local suppurative and life-threatening invasive systemic diseases. Interaction of GAS with human plasminogen (PLG) is a salient characteristic for promoting their systemic dissemination. In the present study, a serotype M28 strain was found predominantly localized in tricellular tight junctions of epithelial cells cultured in the presence of PLG. Several lines of evidence indicated that interaction of PLG with tricellulin, a major component of tricellular tight junctions, is crucial for bacterial localization. A site-directed mutagenesis approach revealed that lysine residues at positions 217 and 252 within the extracellular loop of tricellulin play important roles in PLG-binding activity. Additionally, we demonstrated that PLG functions as a molecular bridge between tricellulin and streptococcal surface enolase (SEN). The wild type strain efficiently translocated across the epithelial monolayer, accompanied by cleavage of transmembrane junctional proteins. In contrast, amino acid substitutions in the PLG-binding motif of SEN markedly compromised those activities. Notably, the interaction of PLG with SEN was dependent on PLG species specificity, which influenced the efficiency of bacterial penetration. Our findings provide insight into the mechanism by which GAS exploits host PLG for acceleration of bacterial invasion into deeper tissues via tricellular tight junctions. PMID:26822058

  18. Physical descriptions of the bacterial nucleoid at large scales, and their biological implications

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    Benza, Vincenzo G; Dorfman, Kevin D; Scolari, Vittore F; Bromek, Krystyna; Cicuta, Pietro; Lagomarsino, Marco Cosentino

    2012-01-01

    Recent experimental and theoretical approaches have attempted to quantify the physical organization (compaction and geometry) of the bacterial chromosome with its complement of proteins (the nucleoid). The genomic DNA exists in a complex and dynamic protein-rich state, which is highly organised at various length scales. This has implications on modulating (when not enabling) the core biological processes of replication, transcription, segregation. We overview the progress in this area, driven in the last few years by new scientific ideas and new interdisciplinary experimental techniques, ranging from high space- and time-resolution microscopy to high-throughput genomics employing sequencing to map different aspects of the nucleoid-related interactome. The aim of this review is to present the wide spectrum of experimental and theoretical findings coherently, from a physics viewpoint. We also discuss some attempts of interpretation that unify different results, highlighting the role that statistical and soft co...

  19. Expression of Lewisb blood group antigen in Helicobacterpylori does not interfere with bacterial adhesion property

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    Peng-Yuan Zheng; Jiesong Hua; Han-Chung Ng; Khay-Guan Yeoh; Ho Bow

    2003-01-01

    AIM: The finding that some Helicobacterpyloristrains expressLewis b (Leb) blood group antigen casts a doubt on the roleof Leb of human gastric epithelium being a receptor for-H.pylori. The aim of this study was to determine if expressionof Leb in H. Pyloriinterferes with bacterial adhesion property.METHODS: Bacterial adhesion to immobilized Leb onmicrotitre plate was performed in 63-H. Pyloristrains obtainedfrom Singapore using in vitro adherence assay. Expression ofLewis blood group antigens was determined by ELISA assay.RESULTS: Among 63 H. Pyloristrains, 28 expressed Lebantigen. In vitro adhesion assay showed that 78.6 % (22/28) of Leb-positive and 74.3 % (26/35) of Leb-negative-H.pyloriisolates were positive for adhesion to immobilized Lebcoated on microtitre plate (P=0.772). In addition, blockingof H. Pylori Leb by prior incubation with anti-Leb monoclonalantibody did not alter thebinding of the bacteria to solid-phase coated Leb.CONCLUSION: The present study suggests that expressionof Leb in H. Pyloridoes not interfere with the bacterialadhesion property. This result supports the notion that Lebpresent on human gastric epithelial cells is capable of beinga receptor for H.pylori.

  20. BOX-PCR-based identification of bacterial species belonging to Pseudomonas syringae: P. viridiflava group

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    Abi S.A. Marques

    2008-01-01

    Full Text Available The phenotypic characteristics and genetic fingerprints of a collection of 120 bacterial strains, belonging to Pseudomonas syringae sensu lato group, P. viridiflava and reference bacteria were evaluated, with the aim of species identification. The numerical analysis of 119 nutritional characteristics did not show patterns that would help with identification. Regarding the genetic fingerprinting, the results of the present study supported the observation that BOX-PCR seems to be able to identify bacterial strains at species level. After numerical analyses of the bar-codes, all pathovars belonging to each one of the nine described genomospecies were clustered together at a distance of 0.72, and could be separated at genomic species level. Two P. syringae strains of unknown pathovars (CFBP 3650 and CFBP 3662 and the three P. syringae pv. actinidiae strains were grouped in two extra clusters and might eventually constitute two new species. This genomic species clustering was particularly evident for genomospecies 4, which gathered P. syringae pvs. atropurpurea, coronafaciens, garçae, oryzae, porri, striafaciens, and zizaniae at a noticeably low distance.

  1. Computer-aided identification of polymorphism sets diagnostic for groups of bacterial and viral genetic variants

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    Huygens Flavia

    2007-08-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs and genes that exhibit presence/absence variation have provided informative marker sets for bacterial and viral genotyping. Identification of marker sets optimised for these purposes has been based on maximal generalized discriminatory power as measured by Simpson's Index of Diversity, or on the ability to identify specific variants. Here we describe the Not-N algorithm, which is designed to identify small sets of genetic markers diagnostic for user-specified subsets of known genetic variants. The algorithm does not treat the user-specified subset and the remaining genetic variants equally. Rather Not-N analysis is designed to underpin assays that provide 0% false negatives, which is very important for e.g. diagnostic procedures for clinically significant subgroups within microbial species. Results The Not-N algorithm has been incorporated into the "Minimum SNPs" computer program and used to derive genetic markers diagnostic for multilocus sequence typing-defined clonal complexes, hepatitis C virus (HCV subtypes, and phylogenetic clades defined by comparative genome hybridization (CGH data for Campylobacter jejuni, Yersinia enterocolitica and Clostridium difficile. Conclusion Not-N analysis is effective for identifying small sets of genetic markers diagnostic for microbial sub-groups. The best results to date have been obtained with CGH data from several bacterial species, and HCV sequence data.

  2. Physical descriptions of the bacterial nucleoid at large scales, and their biological implications

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    Benza, Vincenzo G.; Bassetti, Bruno; Dorfman, Kevin D.; Scolari, Vittore F.; Bromek, Krystyna; Cicuta, Pietro; Cosentino Lagomarsino, Marco

    2012-07-01

    Recent experimental and theoretical approaches have attempted to quantify the physical organization (compaction and geometry) of the bacterial chromosome with its complement of proteins (the nucleoid). The genomic DNA exists in a complex and dynamic protein-rich state, which is highly organized at various length scales. This has implications for modulating (when not directly enabling) the core biological processes of replication, transcription and segregation. We overview the progress in this area, driven in the last few years by new scientific ideas and new interdisciplinary experimental techniques, ranging from high space- and time-resolution microscopy to high-throughput genomics employing sequencing to map different aspects of the nucleoid-related interactome. The aim of this review is to present the wide spectrum of experimental and theoretical findings coherently, from a physics viewpoint. In particular, we highlight the role that statistical and soft condensed matter physics play in describing this system of fundamental biological importance, specifically reviewing classic and more modern tools from the theory of polymers. We also discuss some attempts toward unifying interpretations of the current results, pointing to possible directions for future investigation.

  3. Evolution of public cooperation in a monitored society with implicated punishment and within-group enforcement.

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    Chen, Xiaojie; Sasaki, Tatsuya; Perc, Matjaž

    2015-11-24

    Monitoring with implicated punishment is common in human societies to avert freeriding on common goods. But is it effective in promoting public cooperation? We show that the introduction of monitoring and implicated punishment is indeed effective, as it transforms the public goods game to a coordination game, thus rendering cooperation viable in infinite and finite well-mixed populations. We also show that the addition of within-group enforcement further promotes the evolution of public cooperation. However, although the group size in this context has nonlinear effects on collective action, an intermediate group size is least conductive to cooperative behaviour. This contradicts recent field observations, where an intermediate group size was declared optimal with the conjecture that group-size effects and within-group enforcement are responsible. Our theoretical research thus clarifies key aspects of monitoring with implicated punishment in human societies, and additionally, it reveals fundamental group-size effects that facilitate prosocial collective action.

  4. Evolution of public cooperation in a monitored society with implicated punishment and within-group enforcement

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    Chen, Xiaojie; Sasaki, Tatsuya; Perc, Matjaž

    2015-11-01

    Monitoring with implicated punishment is common in human societies to avert freeriding on common goods. But is it effective in promoting public cooperation? We show that the introduction of monitoring and implicated punishment is indeed effective, as it transforms the public goods game to a coordination game, thus rendering cooperation viable in infinite and finite well-mixed populations. We also show that the addition of within-group enforcement further promotes the evolution of public cooperation. However, although the group size in this context has nonlinear effects on collective action, an intermediate group size is least conductive to cooperative behaviour. This contradicts recent field observations, where an intermediate group size was declared optimal with the conjecture that group-size effects and within-group enforcement are responsible. Our theoretical research thus clarifies key aspects of monitoring with implicated punishment in human societies, and additionally, it reveals fundamental group-size effects that facilitate prosocial collective action.

  5. Other-Regulation in Collaborative Groups: Implications for Regulation Quality

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    Rogat, Toni Kempler; Adams-Wiggins, Karlyn R.

    2014-01-01

    The current study examines variation in other-regulation, conceptualized as efforts by one student to regulate their group's work. This study extends research which has conceptualized other-regulation as temporarily guiding others' conceptual understanding and skill development by broadening the spectrum of other-regulation to include…

  6. Effect of Natural Sunlight on Bacterial Activity and Differential Sensitivity of Natural Bacterioplankton Groups in Northwestern Mediterranean Coastal Waters

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    Alonso-Sáez, Laura; Gasol, Josep M.; Lefort, Thomas; Hofer, Julia; Sommaruga, Ruben

    2006-01-01

    We studied the effects of natural sunlight on heterotrophic marine bacterioplankton in short-term experiments. We used a single-cell level approach involving flow cytometry combined with physiological probes and microautoradiography to determine sunlight effects on the activity and integrity of the cells. After 4 h of sunlight exposure, most bacterial cells maintained membrane integrity and viability as assessed by the simultaneous staining with propidium iodide and SYBR green I. In contrast, a significant inhibition of heterotrophic bacterial activity was detected, measured by 5-cyano-2,3 ditolyl tetrazolium chloride reduction and leucine incorporation. We applied microautoradiography combined with catalyzed reporter deposition-fluorescence in situ hybridization to test the sensitivity of the different bacterial groups naturally occurring in the Northwestern Mediterranean to sunlight. Members of the Gammaproteobacteria and Bacteroidetes groups appeared to be highly resistant to solar radiation, with small changes in activity after exposure. On the contrary, Alphaproteobacteria bacteria were more sensitive to radiation as measured by the cell-specific incorporation of labeled amino acids, leucine, and ATP. Within Alphaproteobacteria, bacteria belonging to the Roseobacter group showed higher resistance than members of the SAR11 cluster. The activity of Roseobacter was stimulated by exposure to photosynthetic available radiation compared to the dark treatment. Our results suggest that UV radiation can significantly affect the in situ single-cell activity of bacterioplankton and that naturally dominating phylogenetic bacterial groups have different sensitivity to natural levels of incident solar radiation. PMID:16957198

  7. Plant-insect interactions under bacterial influence: ecological implications and underlying mechanisms.

    Science.gov (United States)

    Sugio, Akiko; Dubreuil, Géraldine; Giron, David; Simon, Jean-Christophe

    2015-02-01

    Plants and insects have been co-existing for more than 400 million years, leading to intimate and complex relationships. Throughout their own evolutionary history, plants and insects have also established intricate and very diverse relationships with microbial associates. Studies in recent years have revealed plant- or insect-associated microbes to be instrumental in plant-insect interactions, with important implications for plant defences and plant utilization by insects. Microbial communities associated with plants are rich in diversity, and their structure greatly differs between below- and above-ground levels. Microbial communities associated with insect herbivores generally present a lower diversity and can reside in different body parts of their hosts including bacteriocytes, haemolymph, gut, and salivary glands. Acquisition of microbial communities by vertical or horizontal transmission and possible genetic exchanges through lateral transfer could strongly impact on the host insect or plant fitness by conferring adaptations to new habitats. Recent developments in sequencing technologies and molecular tools have dramatically enhanced opportunities to characterize the microbial diversity associated with plants and insects and have unveiled some of the mechanisms by which symbionts modulate plant-insect interactions. Here, we focus on the diversity and ecological consequences of bacterial communities associated with plants and herbivorous insects. We also highlight the known mechanisms by which these microbes interfere with plant-insect interactions. Revealing such mechanisms in model systems under controlled environments but also in more natural ecological settings will help us to understand the evolution of complex multitrophic interactions in which plants, herbivorous insects, and micro-organisms are inserted.

  8. Bacterial group behavior and drug resistance%细菌的群体性行为与耐药

    Institute of Scientific and Technical Information of China (English)

    王辉; 杨崇广; 牛辰

    2011-01-01

    With the increasing usage of antibiotics, bacterial drug resistance has become a serious problem.Bacterial drug resistance is a complex process, involving the host, bacteria and environment, which are independent and interactive factors.For a long time, scientists considered that bacteria behave as individual. Till recently, people found that bacteria communicate with each other. We begin to realize the importance of bacterial group behavior in survival. An increasing number of studies have tended to take bacteria as a group to study the behavior of drug resistance. Now, two important aspects of bacterial group behavior, the biofilm and bacterial programmed cell death draw a lot of attention. In this paper, the research associated with drug resistance mechanisms of biofilms and bacterial programmed cell death is reviewed.%随着抗生素的广泛使用,细菌耐药已经成为一个严重的问题.细菌耐药是一个复杂的过程,涉及宿主、细菌与环境等几个既相互独立又相互作用的因素.很久以来,人们认为细菌以个体为单位进行各种活动,直到发现细菌相互之间也存在联系,才意识到细菌群体对其个体生存的重要性.目前将细菌作为一个群体来研究其耐药行为与机制的研究越来越多,特别是细菌生物膜与细菌程序性死亡两方面受到极大重视.本文综述了细菌生物膜、细菌程序性死亡与耐药相关机制的研究进展.

  9. Group decisions in biodiversity conservation: implications from game theory.

    Directory of Open Access Journals (Sweden)

    David M Frank

    Full Text Available BACKGROUND: Decision analysis and game theory have proved useful tools in various biodiversity conservation planning and modeling contexts. This paper shows how game theory may be used to inform group decisions in biodiversity conservation scenarios by modeling conflicts between stakeholders to identify Pareto-inefficient Nash equilibria. These are cases in which each agent pursuing individual self-interest leads to a worse outcome for all, relative to other feasible outcomes. Three case studies from biodiversity conservation contexts showing this feature are modeled to demonstrate how game-theoretical representation can inform group decision-making. METHODOLOGY AND PRINCIPAL FINDINGS: The mathematical theory of games is used to model three biodiversity conservation scenarios with Pareto-inefficient Nash equilibria: (i a two-agent case involving wild dogs in South Africa; (ii a three-agent raptor and grouse conservation scenario from the United Kingdom; and (iii an n-agent fish and coral conservation scenario from the Philippines. In each case there is reason to believe that traditional mechanism-design solutions that appeal to material incentives may be inadequate, and the game-theoretical analysis recommends a resumption of further deliberation between agents and the initiation of trust--and confidence--building measures. CONCLUSIONS AND SIGNIFICANCE: Game theory can and should be used as a normative tool in biodiversity conservation contexts: identifying scenarios with Pareto-inefficient Nash equilibria enables constructive action in order to achieve (closer to optimal conservation outcomes, whether by policy solutions based on mechanism design or otherwise. However, there is mounting evidence that formal mechanism-design solutions may backfire in certain cases. Such scenarios demand a return to group deliberation and the creation of reciprocal relationships of trust.

  10. Localization of a bacterial group II intron-encoded protein in eukaryotic nuclear splicing-related cell compartments.

    Directory of Open Access Journals (Sweden)

    Rafael Nisa-Martínez

    Full Text Available Some bacterial group II introns are widely used for genetic engineering in bacteria, because they can be reprogrammed to insert into the desired DNA target sites. There is considerable interest in developing this group II intron gene targeting technology for use in eukaryotes, but nuclear genomes present several obstacles to the use of this approach. The nuclear genomes of eukaryotes do not contain group II introns, but these introns are thought to have been the progenitors of nuclear spliceosomal introns. We investigated the expression and subcellular localization of the bacterial RmInt1 group II intron-encoded protein (IEP in Arabidopsis thaliana protoplasts. Following the expression of translational fusions of the wild-type protein and several mutant variants with EGFP, the full-length IEP was found exclusively in the nucleolus, whereas the maturase domain alone targeted EGFP to nuclear speckles. The distribution of the bacterial RmInt1 IEP in plant cell protoplasts suggests that the compartmentalization of eukaryotic cells into nucleus and cytoplasm does not prevent group II introns from invading the host genome. Furthermore, the trafficking of the IEP between the nucleolus and the speckles upon maturase inactivation is consistent with the hypothesis that the spliceosomal machinery evolved from group II introns.

  11. Diverse Bacterial Groups Contribute to the Alkane Degradation Potential of Chronically Polluted Subantarctic Coastal Sediments.

    Science.gov (United States)

    Guibert, Lilian M; Loviso, Claudia L; Borglin, Sharon; Jansson, Janet K; Dionisi, Hebe M; Lozada, Mariana

    2016-01-01

    We aimed to gain insight into the alkane degradation potential of microbial communities from chronically polluted sediments of a subantarctic coastal environment using a combination of metagenomic approaches. A total of 6178 sequences annotated as alkane-1-monooxygenases (EC 1.14.15.3) were retrieved from a shotgun metagenomic dataset that included two sites analyzed in triplicate. The majority of the sequences binned with AlkB described in Bacteroidetes (32 ± 13 %) or Proteobacteria (29 ± 7 %), although a large proportion remained unclassified at the phylum level. Operational taxonomic unit (OTU)-based analyses showed small differences in AlkB distribution among samples that could be correlated with alkane concentrations, as well as with site-specific variations in pH and salinity. A number of low-abundance OTUs, mostly affiliated with Actinobacterial sequences, were found to be only present in the most contaminated samples. On the other hand, the molecular screening of a large-insert metagenomic library of intertidal sediments from one of the sampling sites identified two genomic fragments containing novel alkB gene sequences, as well as various contiguous genes related to lipid metabolism. Both genomic fragments were affiliated with the phylum Planctomycetes, and one could be further assigned to the genus Rhodopirellula due to the presence of a partial sequence of the 23S ribosomal RNA (rRNA) gene. This work highlights the diversity of bacterial groups contributing to the alkane degradation potential and reveals patterns of functional diversity in relation with environmental stressors in a chronically polluted, high-latitude coastal environment. In addition, alkane biodegradation genes are described for the first time in members of Planctomycetes.

  12. Diverse Bacterial Groups Contribute to the Alkane Degradation Potential of Chronically Polluted Subantarctic Coastal Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Guibert, Lilian M.; Loviso, Claudia L.; Borglin, Sharon; Jansson, Janet K.; Dionisi, Hebe M.; Lozada, Mariana

    2015-11-07

    We aimed to gain insight into the alkane degradation potential of microbial communities from chronically polluted sediments of a subantarctic coastal environment using a combination of metagenomic approaches. A total of 6178 sequences annotated as alkane-1-monooxygenases (EC 1.14.15.3) were retrieved from a shotgun metagenomic dataset that included two sites analyzed in triplicate. The majority of the sequences binned with AlkB described in Bacteroidetes (32 ± 13 %) or Proteobacteria (29 ± 7 %), although a large proportion remained unclassified at the phylum level. Operational taxonomic unit (OTU)-based analyses showed small differences in AlkB distribution among samples that could be correlated with alkane concentrations, as well as with site-specific variations in pH and salinity. A number of low-abundance OTUs, mostly affiliated with Actinobacterial sequences, were found to be only present in the most contaminated samples. On the other hand, the molecular screening of a large-insert metagenomic library of intertidal sediments from one of the sampling sites identified two genomic fragments containing novel alkB gene sequences, as well as various contiguous genes related to lipid metabolism. Both genomic fragments were affiliated with the phylum Planctomycetes, and one could be further assigned to the genus Rhodopirellula due to the presence of a partial sequence of the 23S ribosomal RNA (rRNA) gene. This work highlights the diversity of bacterial groups contributing to the alkane degradation potential and reveals patterns of functional diversity in relation with environmental stressors in a chronically polluted, high-latitude coastal environment. In addition, alkane biodegradation genes are described for the first time in members of Planctomycetes.

  13. Implications of the remarkable homogeneity of galaxy groups and clusters

    CERN Document Server

    Balogh, Michael L

    2009-01-01

    We measure the diversity of galaxy groups and clusters with mass M>1E13/h Msun, in terms of the star formation history of their galaxy populations, for the purpose of constraining the mass scale at which environmentally-important processes play a role in galaxy evolution. We consider three different group catalogues, selected in different ways, with photometry and spectroscopy from the Sloan Digital Sky Survey. For each system we measure the fraction of passively-evolving galaxies within R200 and brighter than either Mr=-18 (and with z<0.05) or Mr=-20 (and z<0.1). We use the (u-g) and (r-i) galaxy colours to distinguish between star-forming and passively-evolving galaxies. By considering the binomial distribution expected from the observed number of members in each cluster, we are able to either recover the intrinsic scatter in this fraction, or put robust 95% confidence upper-limits on its value. The intrinsic standard deviation in the fraction of passive galaxies is consistent with a small value of &l...

  14. Crystal structure of the bacterial ribosomal decoding site complexed with amikacin containing the gamma-amino-alpha-hydroxybutyryl (haba) group.

    Science.gov (United States)

    Kondo, Jiro; François, Boris; Russell, Rupert J M; Murray, James B; Westhof, Eric

    2006-08-01

    Amikacin is the 4,6-linked aminoglycoside modified at position N1 of the 2-deoxystreptamine ring (ring II) by the L-haba group. In the present study, the crystal structure of a complex between oligonucleotide containing the bacterial ribosomal A site and amikacin has been solved at 2.7 A resolution. Amikacin specifically binds to the A site in practically the same way as its parent compound kanamycin. In addition, the L-haba group interacts with the upper side of the A site through two direct contacts, O2*...H-N4(C1496) and N4*-H...O6(G1497). The present crystal structure shows how the introduction of the L-haba group on ring II of aminoglycoside is an effective mutation for obtaining a higher affinity to the bacterial A site.

  15. Occurrence and distribution of bacterial tetraether lipids in the Eocene Canadian Arctic paleosols: paleoclimate implications (Invited)

    Science.gov (United States)

    Mehay, S.; Jahren, A.; Schubert, B.; Eberle, J. J.; Summons, R. E.

    2010-12-01

    The Early to Middle Eocene (~56-45 Ma) was a “greenhouse” interval with average global temperatures warmer than any other time in the Cenozoic. This period was characterized by warm climates at high latitude leading to lush forests and the arrival of new mammal groups north of the Arctic Circle (>73°N). Glycerol dialkyl glycerol tetraethers (GDGTs) are membrane-spanning lipids characteristic of certain archaea and bacteria and it has been demonstrated that branched and cyclic GDGTs derived from soil bacteria vary in structure as a function of environmental factors. Proxies based on the relative abundances of methyl branched and cyclopentyl bacterial tetraethers are hypothesized to correlate with mean annual air temperature and soil pH. Here we present the occurrence and distribution of GDGTs in a range of paleosol and sediment samples from Axel Heiberg Island and Ellesmere Island, Nunavut (eastern Canadian Arctic) and Banks Island in the Northwest Territories (western Canadian Arctic). Preliminary results on 11 paleosol samples from the middle Eocene-aged Geodetic Hills Fossil Forest on Axel Heiberg Island indicate a mean annual air temperature of about 9°C. Earlier paleotemperature estimates for Axel Heiberg Island led to values ranging from 9°C to 15°C for the Middle Eocene. Recent temperature prediction for Ellesmere Island (Early Eocene) based upon oxygen isotope ratios of biogenic phosphate from mammal and fish fossils led to ~8°C. In contrast, GDGTs from a marine sedimentary sequence from Lomonosov Ridge in the central Arctic Ocean led to much higher Early Eocene temperature. Thus, the evaluation of the paleotemperature for the Early to Middle Eocene is still a subject of controversy. Ongoing GDGTs analysis of samples from Ellesmere and Banks Islands should give a more comprehensive paleoenvironmental description of the Eocene Arctic. Differences observed between the various paleotemperature estimates will also be discussed. GDGTs distributions are

  16. Bacteria attenuation by iron electrocoagulation governed by interactions between bacterial phosphate groups and Fe(III) precipitates.

    Science.gov (United States)

    Delaire, Caroline; van Genuchten, Case M; Amrose, Susan E; Gadgil, Ashok J

    2016-10-15

    Iron electrocoagulation (Fe-EC) is a low-cost process in which Fe(II) generated from an Fe(0) anode reacts with dissolved O2 to form (1) Fe(III) precipitates with an affinity for bacterial cell walls and (2) bactericidal reactive oxidants. Previous work suggests that Fe-EC is a promising treatment option for groundwater containing arsenic and bacterial contamination. However, the mechanisms of bacteria attenuation and the impact of major groundwater ions are not well understood. In this work, using the model indicator Escherichia coli (E. coli), we show that physical removal via enmeshment in EC precipitate flocs is the primary process of bacteria attenuation in the presence of HCO3(-), which significantly inhibits inactivation, possibly due to a reduction in the lifetime of reactive oxidants. We demonstrate that the adhesion of EC precipitates to cell walls, which results in bacteria encapsulation in flocs, is driven primarily by interactions between EC precipitates and phosphate functional groups on bacteria surfaces. In single solute electrolytes, both P (0.4 mM) and Ca/Mg (1-13 mM) inhibited the adhesion of EC precipitates to bacterial cell walls, whereas Si (0.4 mM) and ionic strength (2-200 mM) did not impact E. coli attenuation. Interestingly, P (0.4 mM) did not affect E. coli attenuation in electrolytes containing Ca/Mg, consistent with bivalent cation bridging between bacterial phosphate groups and inorganic P sorbed to EC precipitates. Finally, we found that EC precipitate adhesion is largely independent of cell wall composition, consistent with comparable densities of phosphate functional groups on Gram-positive and Gram-negative cells. Our results are critical to predict the performance of Fe-EC to eliminate bacterial contaminants from waters with diverse chemical compositions.

  17. Synthesis of antimicrobial cyclodextrins bearing polyarylamino and polyalkylamino groups via click chemistry for bacterial membrane disruption.

    Science.gov (United States)

    Yamamura, Hatsuo; Sugiyama, Yuuki; Murata, Kensuke; Yokoi, Takanori; Kurata, Ryuji; Miyagawa, Atsushi; Sakamoto, Kenji; Komagoe, Keiko; Inoue, Tsuyoshi; Katsu, Takashi

    2014-05-28

    Cyclodextrin derivatives are synthesized as membrane-disrupting agents via a microwave-assisted Huisgen reaction. Their ability to permeabilize bacterial membranes depends on the amino substituents and an appropriate balance of hydrophobicity and hydrophilicity, thus enabling the preparation of derivatives with selective toxicity against bacteria.

  18. Specific antibiotics and nematode trophic groups agree in assessing fungal:bacterial activity in agricultural soil

    DEFF Research Database (Denmark)

    Christensen, S; Dam, M; Vestergaard, M;

    2012-01-01

    There are no methods at hand with a long and proven record for assessing the relative contribution of fungi and bacteria to decomposer activity in soil. Whereas a multitude of methods to determine fungal and bacterial biomass are available, activity assays traditionally relied on the substrate...

  19. Abundance and single-cell activity of heterotrophic bacterial groups in the western Arctic Ocean in summer and winter.

    Science.gov (United States)

    Nikrad, Mrinalini P; Cottrell, M T; Kirchman, D L

    2012-04-01

    Environmental conditions in the western Arctic Ocean range from constant light and nutrient depletion in summer to complete darkness and sea ice cover in winter. This seasonal environmental variation is likely to have an effect on the use of dissolved organic matter (DOM) by heterotrophic bacteria in surface water. However, this effect is not well studied and we know little about the activity of specific bacterial clades in the surface oceans. The use of DOM by three bacterial subgroups in both winter and summer was examined by microautoradiography combined with fluorescence in situ hybridization. We found selective use of substrates by these groups, although the abundances of Ant4D3 (Antarctic Gammaproteobacteria), Polaribacter (Bacteroidetes), and SAR11 (Alphaproteobacteria) were not different between summer and winter in the Beaufort and Chukchi Seas. The number of cells taking up glucose within all three bacterial groups decreased significantly from summer to winter, while the percentage of cells using leucine did not show a clear pattern between seasons. The uptake of the amino acid mix increased substantially from summer to winter by the Ant4D3 group, although such a large increase in uptake was not seen for the other two groups. Use of glucose by bacteria, but not use of leucine or the amino acid mix, related strongly to inorganic nutrients, chlorophyll a, and other environmental factors. Our results suggest a switch in use of dissolved organic substrates from summer to winter and that the three phylogenetic subgroups examined fill different niches in DOM use in the two seasons.

  20. Insights into the strategies used by related group II introns to adapt successfully for the colonisation of a bacterial genome.

    Science.gov (United States)

    Martínez-Rodríguez, Laura; García-Rodríguez, Fernando M; Molina-Sánchez, María Dolores; Toro, Nicolás; Martínez-Abarca, Francisco

    2014-01-01

    Group II introns are self-splicing RNAs and site-specific mobile retroelements found in bacterial and organellar genomes. The group II intron RmInt1 is present at high copy number in Sinorhizobium meliloti species, and has a multifunctional intron-encoded protein (IEP) with reverse transcriptase/maturase activities, but lacking the DNA-binding and endonuclease domains. We characterized two RmInt1-related group II introns RmInt2 from S. meliloti strain GR4 and Sr.md.I1 from S. medicae strain WSM419 in terms of splicing and mobility activities. We used both wild-type and engineered intron-donor constructs based on ribozyme ΔORF-coding sequence derivatives, and we determined the DNA target requirements for RmInt2, the element most distantly related to RmInt1. The excision and mobility patterns of intron-donor constructs expressing different combinations of IEP and intron RNA provided experimental evidence for the co-operation of IEPs and intron RNAs from related elements in intron splicing and, in some cases, in intron homing. We were also able to identify the DNA target regions recognized by these IEPs lacking the DNA endonuclease domain. Our results provide new insight into the versatility of related group II introns and the possible co-operation between these elements to facilitate the colonization of bacterial genomes.

  1. Nosocomial and Community-Acquired Spontaneous Bacterial Peritonitis in patients with liver cirrhosis in China: Comparative Microbiology and Therapeutic Implications

    Science.gov (United States)

    Shi, Lei; Wu, Dan; Wei, Lei; Liu, Suxia; Zhao, Peng; Tu, Bo; Xie, Yangxin; Liu, Yanan; Wang, Xinhua; Liu, Liying; Zhang, Xin; Xu, Zhe; Wang, Fusheng; Qin, Enqiang

    2017-01-01

    Spontaneous bacterial peritonitis (SBP) is a common complication of liver cirrhosis. This study was performed to compare the microbiological characteristics of nosocomial and community-acquired episodes of bacterial peritonitis in China. Five hundred and seventy-five strains were isolated from the ascitic fluid of cirrhotic patients from the Beijing 302 Hospital from January 2014 to December 2014. The patients in the community-acquired SBP (n = 311) and the nosocomial SBP (n = 264) groups exhibited significant differences in clinical symptoms (P < 0.01). In both groups, most of the bacteria were Escherichia coli, Klebsiella pneumoniae, coagulase-negative staphylococcus and Enterococcus. There were more frequent gram-positive cocci (G+ C) in the nosocomial group (n = 170). Compared with the community-acquired group, the proportion of Enterococcus was significantly increased in the nosocomial group (9.0% vs. 16.6%, P < 0.05). The resistance rate of the main pathogenic bacteria to the recommended first-line drug in the guideline was very high. Community-acquired and nosocomial SBP groups exhibited differences in clinical symptoms and antibiotic susceptibility tests. Optimal treatments should be provided for these patients. We recommend that cefoperazone/sulbactam or piperacillin/tazobactam should be used for the empirical treatment of SBP. PMID:28382951

  2. Reference group theory with implications for information studies: a theoretical essay

    Directory of Open Access Journals (Sweden)

    E. Murell Dawson

    2001-01-01

    Full Text Available This article explores the role and implications of reference group theory in relation to the field of library and information science. Reference group theory is based upon the principle that people take the standards of significant others as a basis for making self-appraisals, comparisons, and choices regarding need and use of information. Research that applies concepts of reference group theory to various sectors of library and information studies can provide data useful in enhancing areas such as information-seeking research, special populations, and uses of information. Implications are promising that knowledge gained from like research can be beneficial in helping information professionals better understand the role theory plays in examining ways in which people manage their information and social worlds.

  3. Bacterial abundance on hands and its implications for clinical trials of surgical scrubs.

    OpenAIRE

    Spradlin, C T

    1980-01-01

    The numbers of bacteria on the hands of 157 subjects volunteering for a clinical trial of a surgical scrub preparation were evaluated statistically. Differences among the volunteers with respect to day-to-day variability in bacterial counts were the most important source of variation in these counts. Generally, more bacteria were found on the left hand than on the right. The experimental plan, proposed by the U.S. Food and Drug Administration, contained criteria for acceptability of subjects ...

  4. Bacterially induced weathering of ultramafic rock and its implications for phytoextraction.

    Science.gov (United States)

    Becerra-Castro, Cristina; Kidd, Petra; Kuffner, Melanie; Prieto-Fernández, Ángeles; Hann, Stephan; Monterroso, Carmela; Sessitsch, Angela; Wenzel, Walter; Puschenreiter, Markus

    2013-09-01

    The bioavailability of metals in soil is often cited as a limiting factor of phytoextraction (or phytomining). Bacterial metabolites, such as organic acids, siderophores, or biosurfactants, have been shown to mobilize metals, and their use to improve metal extraction has been proposed. In this study, the weathering capacities of, and Ni mobilization by, bacterial strains were evaluated. Minimal medium containing ground ultramafic rock was inoculated with either of two Arthrobacter strains: LA44 (indole acetic acid [IAA] producer) or SBA82 (siderophore producer, PO4 solubilizer, and IAA producer). Trace elements and organic compounds were determined in aliquots taken at different time intervals after inoculation. Trace metal fractionation was carried out on the remaining rock at the end of the experiment. The results suggest that the strains act upon different mineral phases. LA44 is a more efficient Ni mobilizer, apparently solubilizing Ni associated with Mn oxides, and this appeared to be related to oxalate production. SBA82 also leads to release of Ni and Mn, albeit to a much lower extent. In this case, the concurrent mobilization of Fe and Si indicates preferential weathering of Fe oxides and serpentine minerals, possibly related to the siderophore production capacity of the strain. The same bacterial strains were tested in a soil-plant system: the Ni hyperaccumulator Alyssum serpyllifolium subsp. malacitanum was grown in ultramafic soil in a rhizobox system and inoculated with each bacterial strain. At harvest, biomass production and shoot Ni concentrations were higher in plants from inoculated pots than from noninoculated pots. Ni yield was significantly enhanced in plants inoculated with LA44. These results suggest that Ni-mobilizing inoculants could be useful for improving Ni uptake by hyperaccumulator plants.

  5. Clinical implications of oral candidiasis: host tissue damage and disseminated bacterial disease.

    Science.gov (United States)

    Kong, Eric F; Kucharíková, Sona; Van Dijck, Patrick; Peters, Brian M; Shirtliff, Mark E; Jabra-Rizk, Mary Ann

    2015-02-01

    The clinical significance of polymicrobial interactions, particularly those between commensal species with high pathogenic potential, remains largely understudied. Although the dimorphic fungal species Candida albicans and the bacterium Staphylococcus aureus are common cocolonizers of humans, they are considered leading opportunistic pathogens. Oral candidiasis specifically, characterized by hyphal invasion of oral mucosal tissue, is the most common opportunistic infection in HIV(+) and immunocompromised individuals. In this study, building on our previous findings, a mouse model was developed to investigate whether the onset of oral candidiasis predisposes the host to secondary staphylococcal infection. The findings demonstrated that in mice with oral candidiasis, subsequent exposure to S. aureus resulted in systemic bacterial infection with high morbidity and mortality. Histopathology and scanning electron microscopy of tongue tissue from moribund animals revealed massive C. albicans hyphal invasion coupled with S. aureus deep tissue infiltration. The crucial role of hyphae in the process was demonstrated using a non-hypha-producing and a noninvasive hypha-producing mutant strains of C. albicans. Further, in contrast to previous findings, S. aureus dissemination was aided but not contingent upon the presence of the Als3p hypha-specific adhesion. Importantly, impeding development of mucosal C. albicans infection by administering antifungal fluconazole therapy protected the animals from systemic bacterial disease. The combined findings from this study demonstrate that oral candidiasis may constitute a risk factor for disseminated bacterial disease warranting awareness in terms of therapeutic management of immunocompromised individuals.

  6. Inactivation of indispensable bacterial proteins by early proteins of bacteriophages: implication in antibacterial drug discovery.

    Science.gov (United States)

    Sau, S; Chattoraj, P; Ganguly, T; Chanda, P K; Mandal, N C

    2008-06-01

    Bacteriophages utilize host bacterial cellular machineries for their own reproduction and completion of life cycles. The early proteins that phage synthesize immediately after the entry of their genomes into bacterial cells participate in inhibiting host macromolecular biosynthesis, initiating phage-specific replication and synthesizing late proteins. Inhibition of synthesis of host macromolecules that eventually leads to cell death is generally performed by the physical and/or chemical modification of indispensable host proteins by early proteins. Interestingly, most modified bacterial proteins were shown to take part actively in phage-specific transcription and replication. Research on phages in last nine decades has demonstrated such lethal early proteins that interact with or chemically modify indispensable host proteins. Among the host proteins inhibited by lethal phage proteins, several are not inhibited by any chemical inhibitor available today. Under the context of widespread dissemination of antibiotic-resistant strains of pathogenic bacteria in recent years, the information of lethal phage proteins and cognate host proteins could be extremely invaluable as they may lead to the identification of novel antibacterial compounds. In this review, we summarize the current knowledge about some early phage proteins, their cognate host proteins and their mechanism of action and also describe how the above interacting proteins had been exploited in antibacterial drug discovery.

  7. Iron limitation of a springtime bacterial and phytoplankton community in the Ross Sea: implications for vitamin B12 nutrition

    Directory of Open Access Journals (Sweden)

    Erin M. Bertrand

    2011-08-01

    Full Text Available The Ross Sea is home to some of the largest phytoplankton blooms in the Southern Ocean. Primary production in this system has previously been shown to be iron limited in the summer and periodically iron and vitamin B12 colimited. In this study, we examined trace metal limitation of biological activity in the Ross Sea in the austral spring and considered possible implications for vitamin B12 nutrition. Bottle incubation experiments demonstrated that iron limited phytoplankton growth in the austral spring while B12, cobalt, and zinc did not. This is the first demonstration of iron limitation in a Phaeocystis antarctica-dominated, early season Ross Sea phytoplankton community. The lack of B12 limitation in this location is consistent with previous Ross Sea studies in the austral summer, wherein vitamin additions did not stimulate P. antarctica growth and B12 was limiting only when bacterial abundance was low. Bottle incubation experiments and a bacterial regrowth experiment also revealed that iron addition directly enhanced bacterial growth. B12 uptake measurements in natural water samples and in an iron fertilized bottle incubation demonstrated that bacteria serve not only as a source for vitamin B12, but also as a significant sink, and that iron additions enhanced B12 uptake rates in phytoplankton but not bacteria. Additionally, vitamin uptake rates did not become saturated upon the addition of up to 95 pM B12. A rapid B12 uptake rate was observed after 13 min, which then decreased to a slower constant uptake rate over the next 52 hours. Results from this study highlight the importance of iron availability in limiting early season Ross Sea phytoplankton growth and suggest that rates of vitamin B12 production and consumption may be impacted by iron availability.

  8. The adaptive response of bacterial food-borne pathogens in the environment, host and food: Implications for food safety.

    Science.gov (United States)

    Alvarez-Ordóñez, Avelino; Broussolle, Véronique; Colin, Pierre; Nguyen-The, Christophe; Prieto, Miguel

    2015-11-20

    Bacteria are constantly faced to stress situations in their ecological niches, the food and the host gastrointestinal tract. The capacity to detect and respond to surrounding changes is crucial for bacterial pathogens to survive or grow in changing environments. To this purpose, cells have evolved various sophisticated networks designed to protect against stressors or repair damage caused by them. Challenges can occur during production of foods when subjected to processing, and after food ingestion when confronted with host defensive barriers. Some pathogenic bacteria have shown the capacity to develop stable resistance against extreme conditions within a defined genomic context and a limited number of generations. On the other hand, bacteria can also respond to adverse conditions in a transient manner, through the so-called stress tolerance responses. Bacterial stress tolerance responses include both structural and physiological modifications in the cell and are mediated by complex genetic regulatory machinery. Major aspects in the adaptive response are the sensing mechanisms, the characterization of cell defensive systems, such as the operation of regulatory proteins (e.g. RpoS), the induction of homeostatic and repair systems, the synthesis of shock response proteins, and the modifications of cell membranes, particularly in their fatty acid composition and physical properties. This article reviews certain strategies used by food-borne bacteria to respond to particular stresses (acid, cold stress, extreme pressure) in a permanent or transient manner and discusses the implications that such adaptive responses pose for food safety.

  9. Bacterial mineralization patterns in basaltic aquifers: implications for possible life in martian meteorite ALH84001

    Science.gov (United States)

    Thomas-Keprta, K. L.; McKay, D. S.; Wentworth, S. J.; Stevens, T. O.; Taunton, A. E.; Allen, C. C.; Coleman, A.; Gibson, E. K. Jr; Romanek, C. S.

    1998-01-01

    To explore the formation and preservation of biogenic features in igneous rocks, we have examined the organisms in experimental basaltic microcosms using scanning and transmission electron microscopy. Four types of microorganisms were recognized on the basis of size, morphology, and chemical composition. Some of the organisms mineralized rapidly, whereas others show no evidence of mineralization. Many mineralized cells are hollow and do not contain evidence of microstructure. Filaments, either attached or no longer attached to organisms, are common. Unattached filaments are mineralized and are most likely bacterial appendages (e.g., prosthecae). Features similar in size and morphology to unattached, mineralized filaments are recognized in martian meteorite ALH84001.

  10. Production of biocompatible and antimicrobial bacterial cellulose polymers functionalized by RGDC grafting groups and gentamicin.

    Science.gov (United States)

    Rouabhia, Mahmoud; Asselin, Jérémie; Tazi, Neftaha; Messaddeq, Younès; Levinson, Dennis; Zhang, Ze

    2014-02-12

    Bacterial cellulose (BC), a three-dimensional fibril, is a natural polymer that can be used for many applications. BC effectiveness may be improved by enhancing surface characteristics contributing to a better physiologic interaction with human and animal cells and to intrinsically present antimicrobial agents. In the present study, gentamicin-activated BC membranes were obtained by chemically grafting RGDC peptides (R: arginine; G: glycine; D: aspartic acid; C: cysteine) using coupling agent 3-aminopropyltriethoxysilane (APTES) followed by covalent attachment of gentamicin onto the surface of the BC membrane network. X-ray photoelectron spectroscopy (XPS) analyses showed that the BC-APTES contained 0.7% of silicon in terms of elemental composition, corresponding to a grafting ratio of 1:12. The presence of silicon and nitrogen in the BC-APTES confirmed the surface functionalization of the BC membrane. Fourier-transform infrared (FTIR) analyses show the formation of the secondary amide as supported by the valence bond C═O (ν(C═O)), a characteristic vibrational transition at 1650 cm(-1) which is particularly intense with the BC-RGDC-gentamicin membrane. Energy-dispersive X-ray (EDX) analyses showed a low level of carbon and nitrogen (C + N) in pure BC but a high level of (C + N) in BC-RGDC-gentamicin confirming the surface modification of the BC membrane by RGDC and gentamicin enrichment. Of great interest, the gentamicin-RGDC-grafted BC membranes are bactericidal against Streptococcus mutans but nontoxic to human dermal fibroblasts and thus may be useful for multiple applications such as improved wound healing and drug delivery systems.

  11. Bacterial diversity of siliciclastic sediments in a Thalassia testudinum meadow and the implications for Lucinisca nassula chemosymbiosis

    Science.gov (United States)

    Green-García, Angela M.; Engel, Annette Summers

    2012-10-01

    Despite the ecological and economic importance of Thalassia testudinum (turtle grass) meadows along the Caribbean and Gulf of Mexico coasts, and recognition that microbial activities are critical to plant growth and health, the bacterial diversity of these habitats has been poorly studied. Based on comparative analyses of 16S rRNA gene sequences from sediments in a T. testudinum meadow, 25 major taxonomic groups (excluding candidate divisions) were retrieved, including Alpha- Delta-, and Gamma-proteobacteria, Chloroflexi, Bacteroidetes, Acidobacteria, Spirochaetes, and Firmicutes. The distribution of bacterial groups was linked to a strongly hypoxic and sulfidic redox gradient. The diversity is potentially novel because phylogenetic affinities of sediment sequences compared to contextually annotated environmental clones from different habitats or to cultured representatives indicated approximately 41% were more closely related to each other than to sequences retrieved from these other habitats. Of all the relationships, very few (2.4%) were to cultured organisms, but 27% were to environmental clones retrieved from shallow marine shelf and coastal sediments or from mangroves, estuarine, or wetland sediments. Rare sequences were closely related to endosymbiont groups of Lucinisca nassula (Lucinidea: Bivalvia) hosts collected from the same meadow, which may indicate that the sediment is a potential reservoir for free-living symbionts. This study provides insight into the ecological and evolutionary relationships of the Thalassia-lucinid-bacteria system in tropical to sub-tropical regions.

  12. Acidobacteria form a coherent but highly diverse group within the bacterial domain: evidence from environmental genomics

    DEFF Research Database (Denmark)

    Quaiser, Achim; Ochsenreiter, Torsten; Lanz, Christa;

    2003-01-01

    Acidobacteria have been established as a novel phylum of Bacteria that is consistently detected in many different habitats around the globe by 16S rDNA-based molecular surveys. The phylogenetic diversity, ubiquity and abundance of this group, particularly in soil habitats, suggest an important...

  13. Bacterial histo-blood group antigens contributing to genotype-dependent removal of human noroviruses with a microfiltration membrane.

    Science.gov (United States)

    Amarasiri, Mohan; Hashiba, Satoshi; Miura, Takayuki; Nakagomi, Toyoko; Nakagomi, Osamu; Ishii, Satoshi; Okabe, Satoshi; Sano, Daisuke

    2016-05-15

    We demonstrated the genotype-dependent removal of human norovirus particles with a microfiltration (MF) membrane in the presence of bacteria bearing histo-blood group antigens (HBGAs). Three genotypes (GII.3, GII.4, and GII.6) of norovirus-like particles (NoVLPs) were mixed with three bacterial strains (Enterobacter sp. SENG-6, Escherichia coli O86:K61:B7, and Staphylococcus epidermidis), respectively, and the mixture was filtered with an MF membrane having a nominal pore size of 0.45 μm. All NoVLP genotypes were rejected by the MF membrane in the presence of Enterobacter sp. SENG-6, which excreted HBGAs as extracellular polymeric substances (EPS). This MF membrane removal of NoVLPs was not significant when EPS was removed from cells of Enterobacter sp. SENG-6. GII.6 NoVLP was not rejected with the MF membrane in the presence of E. coli O86:K61:B7, but the removal of EPS of E. coli O86:K61:B7 increased the removal efficiency due to the interaction of NoVLPs with the exposed B-antigen in lipopolysaccharide (LPS) of E. coli O86:K61:B7. No MF membrane removal of all three genotypes was observed when S. epidermidis, an HBGA-negative strain, was mixed with NoVLPs. These results demonstrate that the location of HBGAs on bacterial cells is an important factor in determining the genotype-dependent removal efficiency of norovirus particles with the MF membrane. The presence of HBGAs in mixed liquor suspended solids from a membrane bioreactor (MBR) pilot plant was confirmed by immune-transmission electron microscopy, which implies that bacterial HBGAs can contribute to the genotype-dependent removal of human noroviruses with MBR using MF membrane.

  14. Dimerisation and structural integrity of Heparin Binding Hemagglutinin A from Mycobacterium tuberculosis: implications for bacterial agglutination.

    Science.gov (United States)

    Esposito, Carla; Carullo, Paola; Pedone, Emilia; Graziano, Giuseppe; Del Vecchio, Pompea; Berisio, Rita

    2010-03-19

    Heparin Binding Hemagglutinin A (HBHA) is hitherto the sole virulence factor associated with tuberculosis dissemination from the lungs, the site of primary infection, to epithelial cells. We have previously reported the solution structure of HBHA, a dimeric and elongated molecule. Since oligomerisation of HBHA is associated with its ability to induce bacterial agglutination, we investigated this process using experimental and modelling techniques. We here identified a short segment of HBHA whose presence is mandatory for the stability of folded conformation, whose denaturation is a reversible two-state process. Our data suggest that agglutination-driven cell-cell interactions do not occur via association of HBHA monomers, nor via association of HBHA dimers and open the scenario to a possible trans-dimerisation process.

  15. Superoxide anions produced by Streptococcus pyogenes group A-stimulated keratinocytes are responsible for cellular necrosis and bacterial growth inhibition.

    Science.gov (United States)

    Regnier, Elodie; Grange, Philippe A; Ollagnier, Guillaume; Crickx, Etienne; Elie, Laetitia; Chouzenoux, Sandrine; Weill, Bernard; Plainvert, Céline; Poyart, Claire; Batteux, Frédéric; Dupin, Nicolas

    2016-02-01

    Gram-positive Streptococcus pyogenes (group A Streptococcus or GAS) is a major skin pathogen and interacts with keratinocytes in cutaneous tissues. GAS can cause diverse suppurative and inflammatory infections, such as cellulitis, a common acute bacterial dermo-hypodermitis with a high morbidity. Bacterial isolation yields from the lesions are low despite the strong local inflammation observed, raising numerous questions about the pathogenesis of the infection. Using an in vitro model of GAS-infected keratinocytes, we show that the major ROS produced is the superoxide anion ([Formula: see text]), and that its production is time- and dose-dependent. Using specific modulators of ROS production, we show that [Formula: see text] is mainly synthesized by the cytoplasmic NADPH oxidase. Superoxide anion production leads to keratinocyte necrosis but incomplete inhibition of GAS growth, suggesting that GAS may be partially resistant to the oxidative burst. In conclusion, GAS-stimulated keratinocytes are able to develop an innate immune response based on the production of ROS. This local immune response limits GAS development and induces keratinocyte cell death, resulting in the skin lesions observed in patients with cellulitis.

  16. Implications of smart wear technology for family caregiving relationships: focus group perceptions.

    Science.gov (United States)

    Hall, Scott S; Kandiah, Jayanthi; Saiki, Diana; Nam, Jinhee; Harden, Amy; Park, Soonjee

    2014-10-01

    Technological advances in monitoring vulnerable care-recipients are on the rise. Recent and future development of Smart Wear technology (devices integrated into clothing that monitor care-recipients) might assist family caregivers with tasks related to caring for young children, relatives with disabilities, and frail spouses or parents. However, the development and use of this technology in family caregiving contexts is in its infancy. Focus group interviews of family caregivers were conducted to explore perspectives regarding the potential integration of Smart Wear technology into their family caregiving. Responses were analyzed qualitatively for themes related to perceptions of how Smart Wear could impact relationships between caregivers and care-recipients. Three major themes emerged: quality and quantity of interaction, boundary issues, and implications for anxiety. Implications and recommendations are discussed regarding maximizing the potential benefits of Smart Wear technology in ways that promote and protect healthy relationships among caregivers and care-recipients.

  17. Discordant patterns of bacterial translocation markers and implications for innate immune imbalances in schizophrenia

    Science.gov (United States)

    Severance, Emily G.; Gressitt, Kristin L.; Stallings, Cassie R.; Origoni, Andrea E.; Khushalani, Sunil; Leweke, F. Markus; Dickerson, Faith B.; Yolken, Robert H.

    2013-01-01

    The origin of inflammation in psychiatric disorders is not well understood. The translocation of commensal microbiota across the gastrointestinal barrier can result in a persistent state of low-grade immune activation and/or inflammation. We measured serological surrogate markers of bacterial translocation (soluble CD14 (sCD14) and lipopolysaccharide binding protein (LBP)) in two psychiatric cohorts and compared these levels to C-reactive protein (CRP), body mass index (BMI), and food-related and autoimmune antibodies. The two cohorts were composed of the following: (1) n=141 schizophrenia, n=75 bipolar disorder, n=78 controls; (2) n=78 antipsychotic-naïve first-episode schizophrenia, n=38 medicated first-episode schizophrenia. sCD14 seropositivity conferred a 3.1-fold increased odds of association with schizophrenia (multivariate regressions, OR=3.09, p<0.0001) compared to controls. Case-control differences in sCD14 were not matched by LBP. Quantitative levels of LBP, but not sCD14, correlated with BMI in schizophrenia (R2=0.21, p<0.0001). sCD14 and LBP also exhibited some congruency in schizophrenia with both significantly correlated with CRP (R2=0.26-0.27, p<0.0001) and elevated in females compared to males (p<0.01). Antipsychotic treatment generally did not impact sCD14 or LBP levels except for significant correlations, especially sCD14, with gluten antibodies in antipsychotic-naïve schizophrenia (R2=0.27, p<0.0001). In bipolar disorder, sCD14 levels were significantly correlated with anti-tissue transglutaminase IgG (R2=0.37, p<0.001). In conclusion, these bacterial translocation markers produced discordant and complex patterns of activity, a finding that may reflect an imbalanced, activated innate immune state. Whereas both markers may upregulate following systemic exposure to Gram-negative bacteria, non-lipopolysaccharide-based monocyte activation, autoimmunity and metabolic dysfunction may also contribute to the observed marker profiles. PMID:23746484

  18. A full-length group 1 bacterial sigma factor adopts a compact structure incompatible with DNA binding.

    Science.gov (United States)

    Schwartz, Edmund C; Shekhtman, Alexander; Dutta, Kaushik; Pratt, Matthew R; Cowburn, David; Darst, Seth; Muir, Tom W

    2008-10-20

    The sigma factors are the key regulators of bacterial transcription initiation. Through direct read-out of promoter DNA sequence, they recruit the core RNA polymerase to sites of initiation, thereby dictating the RNA polymerase promoter-specificity. The group 1 sigma factors, which direct the vast majority of transcription initiation during log phase growth and are essential for viability, are autoregulated by an N-terminal sequence known as sigma1.1. We report the solution structure of Thermotoga maritima sigmaA sigma1.1. We additionally demonstrate by using chemical crosslinking strategies that sigma1.1 is in close proximity to the promoter recognition domains of sigmaA. We therefore propose that sigma1.1 autoinhibits promoter DNA binding of free sigmaA by stabilizing a compact organization of the sigma factor domains that is unable to bind DNA.

  19. Identification of DNA motifs implicated in maintenance of bacterial core genomes by predictive modeling.

    Science.gov (United States)

    Halpern, David; Chiapello, Hélène; Schbath, Sophie; Robin, Stéphane; Hennequet-Antier, Christelle; Gruss, Alexandra; El Karoui, Meriem

    2007-09-01

    Bacterial biodiversity at the species level, in terms of gene acquisition or loss, is so immense that it raises the question of how essential chromosomal regions are spared from uncontrolled rearrangements. Protection of the genome likely depends on specific DNA motifs that impose limits on the regions that undergo recombination. Although most such motifs remain unidentified, they are theoretically predictable based on their genomic distribution properties. We examined the distribution of the "crossover hotspot instigator," or Chi, in Escherichia coli, and found that its exceptional distribution is restricted to the core genome common to three strains. We then formulated a set of criteria that were incorporated in a statistical model to search core genomes for motifs potentially involved in genome stability in other species. Our strategy led us to identify and biologically validate two distinct heptamers that possess Chi properties, one in Staphylococcus aureus, and the other in several streptococci. This strategy paves the way for wide-scale discovery of other important functional noncoding motifs that distinguish core genomes from the strain-variable regions.

  20. Identification of DNA motifs implicated in maintenance of bacterial core genomes by predictive modeling.

    Directory of Open Access Journals (Sweden)

    David Halpern

    2007-09-01

    Full Text Available Bacterial biodiversity at the species level, in terms of gene acquisition or loss, is so immense that it raises the question of how essential chromosomal regions are spared from uncontrolled rearrangements. Protection of the genome likely depends on specific DNA motifs that impose limits on the regions that undergo recombination. Although most such motifs remain unidentified, they are theoretically predictable based on their genomic distribution properties. We examined the distribution of the "crossover hotspot instigator," or Chi, in Escherichia coli, and found that its exceptional distribution is restricted to the core genome common to three strains. We then formulated a set of criteria that were incorporated in a statistical model to search core genomes for motifs potentially involved in genome stability in other species. Our strategy led us to identify and biologically validate two distinct heptamers that possess Chi properties, one in Staphylococcus aureus, and the other in several streptococci. This strategy paves the way for wide-scale discovery of other important functional noncoding motifs that distinguish core genomes from the strain-variable regions.

  1. Structural and sequence analysis of imelysin-like proteins implicated in bacterial iron uptake.

    Directory of Open Access Journals (Sweden)

    Qingping Xu

    Full Text Available Imelysin-like proteins define a superfamily of bacterial proteins that are likely involved in iron uptake. Members of this superfamily were previously thought to be peptidases and were included in the MEROPS family M75. We determined the first crystal structures of two remotely related, imelysin-like proteins. The Psychrobacter arcticus structure was determined at 2.15 Å resolution and contains the canonical imelysin fold, while higher resolution structures from the gut bacteria Bacteroides ovatus, in two crystal forms (at 1.25 Å and 1.44 Å resolution, have a circularly permuted topology. Both structures are highly similar to each other despite low sequence similarity and circular permutation. The all-helical structure can be divided into two similar four-helix bundle domains. The overall structure and the GxHxxE motif region differ from known HxxE metallopeptidases, suggesting that imelysin-like proteins are not peptidases. A putative functional site is located at the domain interface. We have now organized the known homologous proteins into a superfamily, which can be separated into four families. These families share a similar functional site, but each has family-specific structural and sequence features. These results indicate that imelysin-like proteins have evolved from a common ancestor, and likely have a conserved function.

  2. Group A Streptococcal Cysteine Protease Cleaves Epithelial Junctions and Contributes to Bacterial Translocation*

    Science.gov (United States)

    Sumitomo, Tomoko; Nakata, Masanobu; Higashino, Miharu; Terao, Yutaka; Kawabata, Shigetada

    2013-01-01

    Group A Streptococcus (GAS) is an important human pathogen that possesses an ability to translocate across the epithelial barrier. In this study, culture supernatants of tested GAS strains showed proteolytic activity against human occludin and E-cadherin. Utilizing various types of protease inhibitors and amino acid sequence analysis, we identified SpeB (streptococcal pyrogenic exotoxin B) as the proteolytic factor that cleaves E-cadherin in the region neighboring the calcium-binding sites within the extracellular domain. The cleaving activities of culture supernatants from several GAS isolates were correlated with the amount of active SpeB, whereas culture supernatants from an speB mutant showed no such activities. Of note, the wild type strain efficiently translocated across the epithelial monolayer along with cleavage of occludin and E-cadherin, whereas deletion of the speB gene compromised those activities. Moreover, destabilization of the junctional proteins was apparently relieved in cells infected with the speB mutant, as compared with those infected with the wild type. Taken together, our findings indicate that the proteolytic efficacy of SpeB in junctional degradation allows GAS to invade deeper into tissues. PMID:23532847

  3. A novel role of cannabinoids: implication in the fever induced by bacterial lipopolysaccharide.

    Science.gov (United States)

    Benamar, Khalid; Yondorf, Menachem; Meissler, Joseph J; Geller, Ellen B; Tallarida, Ronald J; Eisenstein, Toby K; Adler, Martin W

    2007-03-01

    There is continuing interest in elucidating the actions of drugs of abuse on the immune system and on infection. The present study investigated the effects of the cannabinoid (CB) receptor agonist aminoalkylindole, (+)-WIN 55,212-2 [(4,5-dihydro-2-methyl-4(4-morpholinylmethyl)-1-(1-naphthalenyl-carbonyl)-6H-pyrrolo[3,2,1ij]quinolin-6-one], on fever produced after injection of lipopolysaccharide (LPS), a component of the outer membrane of Gram-negative bacteria, the best known and most frequently used experimental model. Intraperitoneal injection of LPS (50 mug/kg) induced a biphasic fever, with the first peak at 180 min and the second at 300 min postinjection. Pretreatment with a nonhypothermic dose of the cannabinoid receptor agonist WIN 55,212-2 (0.5-1.5 mg/kg i.p.) antagonized the LPS-induced fever. However, pretreatment with the inactive enantiomer WIN 55,212-3 [1.5 mg/kg i.p.; S-(-)-[2,3-dihydro-5-methyl-3-[(morpholinyl)methyl]pyrrolo[1,2,3-de]-1,4-benzoxazinyl]-(1-naphthanlenyl)methanone mesylate] did not. The inhibitory effect of WIN 55,212-2 on LPS-induced fever was reversed by SR141716 [N-(piperdin-1-yl)-5-(4-chloropheny)-1-(2,4-dichloropheny)-4-methyl-1H-pyrazole-3-carboxamide hydrochloride], a selective CB1 receptor antagonist, but not by SR144528 (N-[(1S)-endo-1,3,3-trimethylbicyclo[2.2.1]heptan-2-yl]5-(4-choro-3-methylphenyl)-1-(4-methylbenzyl)pyrazole-3-carboxamide), a selective antagonist at the CB2 receptor. The present results show that cannabinoids interact with systemic bacterial LPS injection and indicate a role of the CB1 receptor subtype in the pathogenesis of LPS fever.

  4. Effects of iron supplementation on dominant bacterial groups in the gut, faecal SCFA and gut inflammation: a randomised, placebo-controlled intervention trial in South African children.

    Science.gov (United States)

    Dostal, Alexandra; Baumgartner, Jeannine; Riesen, Nathalie; Chassard, Christophe; Smuts, Cornelius M; Zimmermann, Michael B; Lacroix, Christophe

    2014-08-28

    Fe supplementation is a common strategy to correct Fe-deficiency anaemia in children; however, it may modify the gut microbiota and increase the risk for enteropathogenic infection. In the present study, we studied the impact of Fe supplementation on the abundance of dominant bacterial groups in the gut, faecal SCFA concentration and gut inflammation in children living in rural South Africa. In a randomised, placebo-controlled intervention trial of 38 weeks, 6- to 11-year-old children with Fe deficiency received orally either tablets containing 50 mg Fe as FeSO₄ (n 22) for 4 d/week or identical placebo (n 27). In addition, Fe-sufficient children (n 24) were included as a non-treated reference group. Faecal samples were analysed at baseline and at 2, 12 and 38 weeks to determine the effects of Fe supplementation on ten bacterial groups in the gut (quantitative PCR), faecal SCFA concentration (HPLC) and gut inflammation (faecal calprotectin concentration). At baseline, concentrations of bacterial groups in the gut, faecal SCFA and faecal calprotectin did not differ between Fe-deficient and Fe-sufficient children. Fe supplementation significantly improved Fe status in Fe-deficient children and did not significantly increase faecal calprotectin concentration. Moreover, no significant effect of Fe treatment or time × treatment interaction on the concentrations of bacterial groups in the gut or faecal SCFA was observed compared with the placebo treatment. Also, there were no significant differences observed in the concentrations of any of the bacterial target groups or faecal SCFA at 2, 12 or 38 weeks between the three groups of children when correcting for baseline values. The present study suggests that in African children with a low enteropathogen burden, Fe status and dietary Fe supplementation did not significantly affect the dominant bacterial groups in the gut, faecal SCFA concentration or gut inflammation.

  5. Seasonal Variations in the Contributions of Different Bacterial Groups to the Uptake of Low-Molecular-Weight Compounds in Northwestern Mediterranean Coastal Waters▿

    Science.gov (United States)

    Alonso-Sáez, Laura; Gasol, Josep M.

    2007-01-01

    We analyzed the contributions of different heterotrophic bacterial groups to the uptake of several low-molecular weight compounds during a seasonal cycle on the northwestern Mediterranean coast (Blanes Bay Microbial Observatory). The bacterial assemblage structure had been shown to change substantially year-round for this site, but whether changes in the activities of the different bacterial groups also occurred on the seasonal scale was unknown. Microautoradiography combined with catalyzed reporter deposition fluorescence in situ hybridization was used to analyze the patterns of glucose, amino acid, and ATP uptake by different bacterial groups. Gammaproteobacteria and Bacteroidetes were not very active in the uptake of glucose at any time of the year (20% of cells were active). Dissolved free amino acids were taken up considerably by Alphaproteobacteria and Gammaproteobacteria but not by Bacteroidetes. Relatively high percentages of cells of the three broad phylogenetic groups actively took up ATP, which could be related to the important phosphorous limitation of bacterial production during most of the year in Blanes Bay. The contribution of SAR11 to the uptake of the monomers was variable year-round, generally with fewer than 30% of the cells being active. By contrast, Roseobacter were highly overrepresented in the uptake of all the substrates throughout all the year, with more than 50% of cells being active in all the samples and for all substrates. Our results suggest that substantial changes in the activity of some phylogenetic groups of bacteria occur throughout the year. PMID:17400772

  6. Congruencies between photoautotrophic groups in springs of the Italian Alps: implications for conservation strategies

    Directory of Open Access Journals (Sweden)

    Marco CANTONATI

    2011-09-01

    Full Text Available Even though a number of studies have demonstrated the importance of photoautotrophic organisms in spring habitats, investigations that consider several photoautotrophic taxonomic groups are lacking. Within the framework of a multidisciplinary project on springs of the south-eastern Alps, we studied algae, diatoms, lichens, and bryophytes and (1 compared the alpha, beta and gamma diversity, and the composition of the studied groups between carbonate and siliceous springs, (2 estimated the nonrandomness of species combinations within organismal groups, and (3 examined the congruence in species assemblage patterns across taxonomic groups. In 40 springs, 69 species of algae, 110 species of diatoms, 29 species of lichens, and 62 species of bryophytes were found. Diatoms, lichens and bryophytes had higher species-richness in siliceous springs, while other algae had higher richness in carbonate springs. For all taxonomic groups, carbonate and siliceous springs host different assemblages, indicating that both types of substrata contribute to the overall regional diversity of spring photoautotrophs. In individual springs, the photoautotroph groups are characterised by a similar proportion of species of their regional pool, and form relatively speciespoor communities with a high turnover of species among springs. This pattern has important implications for conservation, suggesting that the protection of single sites might not be effective, and that a biodiversity conservation plan for spring habitats should be developed at the regional level, and include a network of sites. Interestingly, the co-occurrence indices suggested that, in individual springs, stochastic processes might the most important mechanisms in the establishment of local assemblages. A weak cross-taxon congruency was found, suggesting that a single taxon surrogate will not adequately represent other photoautotrophic groups. Therefore, spring conservation plans for photoautotrophs should

  7. Pyrosequencing analysis of bacterial diversity in soils contaminated long-term with PAHs and heavy metals: Implications to bioremediation.

    Science.gov (United States)

    Kuppusamy, Saranya; Thavamani, Palanisami; Megharaj, Mallavarapu; Venkateswarlu, Kadiyala; Lee, Yong Bok; Naidu, Ravi

    2016-11-05

    Diversity, distribution and composition of bacterial community of soils contaminated long-term with both polycyclic aromatic hydrocarbons (PAHs) and heavy metals were explored for the first time following 454 pyrosequencing. Strikingly, the complete picture of the Gram positive (+ve) and Gram negative (-ve) bacterial profile obtained in our study illustrates novel postulates that include: (1) Metal-tolerant and PAH-degrading Gram -ves belonging to the class Alphaproteobacteria persist relatively more in the real contaminated sites compared to Gram +ves, (2) Gram +ves are not always resistant to heavy metal toxicity, (3) Stenotrophomonas followed by Burkholderia and Pseudomonas are the dominant genera of PAH degraders with high metabolic activity in long-term contaminated soils, (4) Actinobacteria is the predominant group among the Gram +ves in soils contaminated with high molecular weight PAHs that co-exist with toxic heavy metals like Pb, Cu and Zn, (5) Microbial communities are nutrient-driven in natural environments and (6) Catabolically potential Gram +/-ves with diverse applicability to remediate the real contaminated sites evolve eventually in the historically-polluted soils. Thus, the most promising indigenous Gram +/-ve strains from the long-term contaminated sites with increased catabolic potential, enzymatic activity and metal tolerance need to be harnessed for mixed contaminant cleanups.

  8. Effect of metals on a siderophore producing bacterial isolate and its implications on microbial assisted bioremediation of metal contaminated soils.

    Science.gov (United States)

    Gaonkar, Teja; Bhosle, Saroj

    2013-11-01

    A bacterial isolate producing siderophore under iron limiting conditions, was isolated from mangroves of Goa. Based on morphological, biochemical, chemotaxonomical and 16S rDNA studies, the isolate was identified as Bacillus amyloliquefaciens NAR38.1. Preliminary characterization of the siderophore indicated it to be catecholate type with dihydroxy benzoate as the core component. Optimum siderophore production was observed at pH 7 in mineral salts medium (MSM) without any added iron with glucose as the carbon source. Addition of NaCl in the growth medium showed considerable decrease in siderophore production above 2% NaCl. Fe(+2) and Fe(+3) below 2 μM and 40 μM concentrations respectively, induced siderophore production, above which the production was repressed. Binding studies of the siderophore with Fe(+2) and Fe(+3) indicated its high affinity towards Fe(+3). The siderophore concentration in the extracellular medium was enhanced when MSM was amended with essential metals Zn, Co, Mo and Mn, however, decreased with Cu, while the concentration was reduced with abiotic metals As, Pb, Al and Cd. Significant increase in extracellular siderophore production was observed with Pb and Al at concentrations of 50 μM and above. The effect of metals on siderophore production was completely mitigated in presence of Fe. The results implicate effect of metals on the efficiency of siderophore production by bacteria for potential application in bioremediation of metal contaminated iron deficient soils especially in the microbial assisted phytoremediation processes.

  9. A Rich Morphological Diversity of Biosaline Drying Patterns Is Generated by Different Bacterial Species, Different Salts and Concentrations: Astrobiological Implications

    Science.gov (United States)

    Gómez Gómez, José María; Medina, Jesús; Rull, Fernando

    2016-07-01

    Biosaline formations (BSFs) are complex self-organized biomineral patterns formed by "hibernating" bacteria as the biofilm that contains them dries out. They were initially described in drying biofilms of Escherichia coli cells + NaCl. Due to their intricate 3-D morphology and anhydrobiosis, these biomineralogical structures are of great interest in astrobiology. Here we report experimental data obtained with various alkali halide salts (NaF, NaCl, NaBr, LiCl, KCl, CsCl) on BSF formation with E. coli and Bacillus subtilis bacteria at two saline concentrations: 9 and 18 mg/mL. Our results indicate that, except for LiCl, which is inactive, all the salts assayed are active during BSF formation and capable of promoting the generation of distinctive drying patterns at each salt concentration. Remarkably, the BSFs produced by these two bacterial species produce characteristic architectural hallmarks as the BSF dries. The potential biogenicity of these biosaline drying patterns is studied, and the astrobiological implications of these findings are discussed.

  10. Bacterial conversion of hydroxylamino aromatic compounds by both lyase and mutase enzymes involves intramolecular transfer of hydroxyl groups.

    Science.gov (United States)

    Nadeau, Lloyd J; He, Zhongqi; Spain, Jim C

    2003-05-01

    Hydroxylamino aromatic compounds are converted to either the corresponding aminophenols or protocatechuate during the bacterial degradation of nitroaromatic compounds. The origin of the hydroxyl group of the products could be the substrate itself (intramolecular transfer mechanism) or the solvent water (intermolecular transfer mechanism). The conversion of hydroxylaminobenzene to 2-aminophenol catalyzed by a mutase from Pseudomonas pseudoalcaligenes JS45 proceeds by an intramolecular hydroxyl transfer. The conversions of hydroxylaminobenzene to 2- and 4-aminophenol by a mutase from Ralstonia eutropha JMP134 and to 4-hydroxylaminobenzoate to protocatechuate by a lyase from Comamonas acidovorans NBA-10 and Pseudomonas sp. strain 4NT were proposed, but not experimentally proved, to proceed by the intermolecular transfer mechanism. GC-MS analysis of the reaction products formed in H(2)(18)O did not indicate any (18)O-label incorporation during the conversion of hydroxylaminobenzene to 2- and 4-aminophenols catalyzed by the mutase from R. eutropha JMP134. During the conversion of 4-hydroxylaminobenzoate catalyzed by the hydroxylaminolyase from Pseudomonas sp. strain 4NT, only one of the two hydroxyl groups in the product, protocatechuate, was (18)O labeled. The other hydroxyl group in the product must have come from the substrate. The mutase in strain JS45 converted 4-hydroxylaminobenzoate to 4-amino-3-hydroxybenzoate, and the lyase in Pseudomonas strain 4NT converted hydroxylaminobenzene to aniline and 2-aminophenol but not to catechol. The results indicate that all three types of enzyme-catalyzed rearrangements of hydroxylamino aromatic compounds proceed via intramolecular transfer of hydroxyl groups.

  11. Bacterial spore survival after exposure to HZE particle bombardment -implication for the lithopanspermia hypothesis.

    Science.gov (United States)

    Moeller, Ralf; Berger, Thomas; Matthiä, Daniel; Okayasu, Ryuichi; Kitamura, H.; Reitz, Guenther

    Based on their unique resistance to various space parameters, bacterial spores (mainly spores of Bacillus subtilis) are one of the model systems used for astrobiological studies. More re-cently, spores of B. subtilis have been applied for experimental research on the likelihood of interplanetary transfer of life. Since its first postulation by Arrhenius in 1903, the pansper-mia hypothesis has been revisited many-times, e.g. after the discovery of several lunar and Martian meteorites on Earth [1,2]. These information provided intriguing evidence that rocks may naturally be transferred between the terrestrial planets. The scenario of panspermia, now termed "lithopanspermia" involves three basic hypothetical steps: (i) the escape process, i.e. removal to space of biological material, which has survived being lifted from the surface to high altitudes; (ii) interim state in space, i.e., survival of the biological material over time scales comparable with interplanetary or interstellar passage; (iii) the entry process, i.e. nondestruc-tive deposition of the biological material on another planet [2]. In our research, spores of B. subtilis were used to study the effects of galactic cosmic radiation on spore survival and induced mutations. On an interplanetary journey, outside a protective magnetic field, spore-containing rocks would be exposed to bombardment by high-energy charged particle radiation from galac-tic sources and from the sun. Air-dried spore layers on three different host materials (i.e., non-porous igneous rocks (gabbro), quartz, and spacecraft analog material (aluminum)) were irradiated with accelerated heavy ions (Helium and Iron) with a LET (linear energy transfer) ˆ of 2 and 200 keV/Am, at the Heavy Ion Medical Accelerator (HIMAC) at the National In-stitute of Radiological Sciences, (NIRS), Chiba, Japan in the frame of the HIMAC research project 20B463 "Characterization of heavy ion-induced damage in Bacillus subtilis spores and their global

  12. Surface modification of bacterial cellulose nanofibers for property enhancement of optically transparent composites: dependence on acetyl-group DS.

    Science.gov (United States)

    Ifuku, Shinsuke; Nogi, Masaya; Abe, Kentaro; Handa, Keishin; Nakatsubo, Fumiaki; Yano, Hiroyuki

    2007-06-01

    Bacterial cellulose (BC) nanofibers were acetylated to enhance the properties of optically transparent composites of acrylic resin reinforced with the nanofibers. A series of BC nanofibers acetylated from degree-of-substitution (DS) 0 to 1.76 were obtained. X-ray diffraction profiles indicated that acetylation proceeded from the surface to the core of BC nanofibers, and scanning electron microscopy images showed that the volume of nanofibers increases by the bulky acetyl group. Since acetylation decreased the refractive index of cellulose, regular transmittance of composites comprised of 63% BC nanofiber was improved, and deterioration at 580 nm because of fiber reinforcement was suppressed to only 3.4%. Acetylation of nanofibers changed their surface properties and reduced the moisture content of the composite to about one-third that of untreated composite, although excessive acetylation increased hygroscopicity. Furthermore, acetylation was found to reduce the coefficient of thermal expansion of a BC sheet from 3 x 10(-6) to below 1 x 10(-6) 1/K.

  13. Defence against methylglyoxal in Group A Streptococcus: a role for Glyoxylase I in bacterial virulence and survival in neutrophils?

    Science.gov (United States)

    Zhang, May M; Ong, Cheryl-lynn Y; Walker, Mark J; McEwan, Alastair G

    2016-03-01

    Methylglyoxal is a dicarbonyl compound that acts as a toxic electrophile in biological systems. Methylglyoxal is produced in certain bacteria as a byproduct of glycolysis through methylglyoxal synthase. Like many bacteria, Group A Streptococcus (GAS), a Gram-positive human pathogen responsible for a wide spectrum of diseases, uses a two-step glyoxalase system to remove methylglyoxal. However, bioinformatic analysis revealed that no homologue of methylglyoxal synthase is present in GAS, suggesting that the role of the glyoxalase system is to detoxify methylglyoxal produced by the host. In this study, we investigated the role of methylglyoxal detoxification in the pathogenesis of GAS. A mutant (5448ΔgloA), deficient in glyoxylase I (S-lactoylglutathione lyase), was constructed and tested for susceptibility to methylglyoxal, human neutrophil survival and virulence in a murine model of infection. 5448ΔgloA was more sensitive to methylglyoxal and was also more susceptible to human neutrophil killing. Inhibition of neutrophil myeloperoxidase rescued the gloA-deficient mutant indicating that this enzyme was required for methylglyoxal production. Furthermore, the 5448ΔgloA mutant was slower at disseminating into the blood in the murine model. These data suggest that neutrophils produce methylglyoxal as an antimicrobial agent during bacterial infection, and the glyoxalase system is part of the GAS defence against the innate immune system during pathogenesis.

  14. Tetracyclines in Food and Feedingstuffs: From Regulation to Analytical Methods, Bacterial Resistance, and Environmental and Health Implications

    Directory of Open Access Journals (Sweden)

    Fabio Granados-Chinchilla

    2017-01-01

    Full Text Available Antibiotics are widely used as growth promoters in animal husbandry; among them, the tetracyclines are a chemical group of relevance, due to their wide use in agriculture, surpassing in quantities applied almost every other antibiotic family. Seeing the considerable amounts of tetracyclines used worldwide, monitoring of these antibiotics is paramount. Advances must be made in the analysis of antibiotics to assess correct usage and dosage of tetracyclines in food and feedstuffs and possible residues in pertinent environmental samples. The tetracyclines are still considered a clinically relevant group of antibiotics, though dissemination of tolerance and resistance determinants have limited their use. This review focuses on four different aspects: (i tetracyclines, usage, dosages, and regulatory issues that govern their food-related application, with particular attention to the prohibitions and restrictions that several countries have enforced in recent years by agencies from both the United States and the European Union, (ii analytical methods for tetracyclines, determination, and residues thereof in feedstuffs and related matrices with an emphasis on the most relevant and novel techniques, including both screening and confirmatory methods, (iii tetracycline resistance and tetracycline-resistant bacteria in feedstuff, and (iv environmental and health risks accompanying the use of tetracyclines in animal nutrition. In the last two cases, we discuss the more relevant undesirable effects that tetracyclines exert over bacterial communities and nontarget species including unwanted effects in farmers.

  15. Tetracyclines in Food and Feedingstuffs: From Regulation to Analytical Methods, Bacterial Resistance, and Environmental and Health Implications

    Science.gov (United States)

    Granados-Chinchilla, Fabio

    2017-01-01

    Antibiotics are widely used as growth promoters in animal husbandry; among them, the tetracyclines are a chemical group of relevance, due to their wide use in agriculture, surpassing in quantities applied almost every other antibiotic family. Seeing the considerable amounts of tetracyclines used worldwide, monitoring of these antibiotics is paramount. Advances must be made in the analysis of antibiotics to assess correct usage and dosage of tetracyclines in food and feedstuffs and possible residues in pertinent environmental samples. The tetracyclines are still considered a clinically relevant group of antibiotics, though dissemination of tolerance and resistance determinants have limited their use. This review focuses on four different aspects: (i) tetracyclines, usage, dosages, and regulatory issues that govern their food-related application, with particular attention to the prohibitions and restrictions that several countries have enforced in recent years by agencies from both the United States and the European Union, (ii) analytical methods for tetracyclines, determination, and residues thereof in feedstuffs and related matrices with an emphasis on the most relevant and novel techniques, including both screening and confirmatory methods, (iii) tetracycline resistance and tetracycline-resistant bacteria in feedstuff, and (iv) environmental and health risks accompanying the use of tetracyclines in animal nutrition. In the last two cases, we discuss the more relevant undesirable effects that tetracyclines exert over bacterial communities and nontarget species including unwanted effects in farmers. PMID:28168081

  16. A randomised comparison of meropenem with cefotaxime or ceftriaxone for the treatment of bacterial meningitis in adults. Meropenem Meningitis Study Group.

    Science.gov (United States)

    Schmutzhard, E; Williams, K J; Vukmirovits, G; Chmelik, V; Pfausler, B; Featherstone, A

    1995-07-01

    Third-generation cephalosporins are presently the agents of choice for the empirical antimicrobial therapy of bacterial meningitis. However, a number of factors associated with these agents, namely the development of resistance by pneumococci, limited activity against some Enterobacteriaceae and Pseudomonas spp., and the possible adverse effects of their bacteriolytic mode of action, indicate that newer classes of antimicrobial agents be evaluated for the treatment of bacterial meningitis. Meropenem is a carbapenem antibiotic which is highly active against the major bacterial pathogens causing meningitis, and penetrates well into the cerebrospinal fluid. Two prospective randomised studies in 56 adult bacterial meningitis patients have compared meropenem 40 mg/kg 8-hourly, up to a maximum of 6 g/day (n = 28) with cephalosporin treatment, i.e. cefotaxime (n = 17) or ceftriaxone (n = 11). Patients were assessed by neurological examination, Glasgow Coma Score and Herson-Todd score. Clinical cure was observed in all 23 evaluable patients treated with meropenem (100%) and with 17 of the 22 evaluable cephalosporin-treated patients (77%). All pre-treatment isolates were eradicated except one isolate of Staphylococcus aureus in a cefotaxime-treated patient. Neurological sequelae were noted in three meropenem and four cephalosporin-treated patients. No patients in either treatment group experienced seizures after the start of therapy. This was despite the fact that a patient in each group had experienced seizures before therapy, several had underlying CNS disorders, and that doses of 6 g/day of meropenem were given. Hearing impairment was recorded in 11 meropenem and nine cephalosporin treated patients. Three patients in the meropenem group and one in the cephalosporin group died during treatment for reasons unrelated to study therapy. Overall, the results of this study indicate that meropenem is an effective and well-tolerated antibiotic for the treatment of bacterial

  17. Increased likelihood of bacterial pathogens in the coronal sulcus and urethra of uncircumcised men in a diverse group of HIV infected and uninfected patients in India

    Directory of Open Access Journals (Sweden)

    John A Schneider

    2012-01-01

    Full Text Available Background: The biological mechanism of circumcision as potentiating HIV prevention is poorly understood. Foreskin microbiota has been postulated as having a potential role; however, little is known about the relationship between bacterial pathogens and circumcision in adults. Materials and Methods: We sampled the coronal sulcus of a diverse group of circumcised and uncircumcised men (n=315 from a government chest hospital and fertility clinic in Hyderabad, Andhra Pradesh, India. Genital examination was conducted on three groups of men: Group 1 - HIV infected; Group 2 - TB infected; Group 3 - control. Aerobic and anaerobic specimens were cultured according to standard clinical protocols, and results were analyzed following multivariate logistic regression models. Results: Three hundred fifteen study participants - 47.6% of Group 1, 36.5% of Group 2, and 15.9% of Group 3 - were enrolled in the study and included in all analyses. Overall 37.1% of the participants were circumcised without variation across groups (P=0.29. Smegma was observed in 18.7% of the participants with no cases observed in Group 3 (P<0.001. Gram-negative pathogens were more prevalent among study participants in Group 1 (22.7% and Group 2 (30.4% as compared with those in Group 3 (6.0% (P=0.003. In multivariate regression analysis, controlling for group, age, and presence of smegma, uncircumcised men were more likely to be colonized with gram positives [Adjusted Odds Ratio (AOR 1.9; P<0.05], gram negatives (AOR 2.4; P<0.05, or any pathogen (AOR 2.8; P<0.005. Conclusions: Uncircumcised men in this population in South India are more likely to harbor bacterial pathogens in the coronal sulcus than do their circumcised counterparts. Future studies should examine the relationship between foreskin microbiota and HIV transmission.

  18. Six new species of the Anopheles leucosphyrus group, reinterpretation of An. elegans and vector implications.

    Science.gov (United States)

    Sallum, M A M; Peyton, E L; Wilkerson, R C

    2005-06-01

    Among Oriental anopheline mosquitoes (Diptera: Culicidae), several major vectors of forest malaria belong to the group of Anopheles (Cellia) leucosphyrus Dönitz. We have morphologically examined representative material (> 8000 specimens from seven countries) for taxonomic revision of the Leucosphyrus Group. Six new species are here described from adult, pupal and larval stages (with illustrations of immature stages) and formally named as follows: An. latens n. sp. (= An. leucosphyrus species A of Baimai et al., 1988b), An. cracens n. sp., An. scanloni n. sp., An. baimaii n. sp. (formerly An. dirus species B, C, D, respectively), An. mirans n. sp. and An. recens n. sp. Additionally, An. elegans (James) is redescribed and placed in the complex of An. dirus Peyton & Harrison (comprising An. baimaii, An. cracens, An. dirus, An. elegans, An. nemophilous Peyton and Ramalingam, An. scanloni and An. takasagoensis Morishita) of the Leucosphyrus Subgroup, together with An. baisasi Colless and the An. leucosphyrus complex (comprising An. balabacensis Baisas, An. introlatus Baisas, An. latens and An. leucosphyrus). Hence, the former Elegans Subgroup is renamed the Hackeri Subgroup (comprising An. hackeri Edwards, An. pujutensis Colless, An. recens and An. sulawesi Waktoedi). Distribution data and bionomics of the newly defined species are given, based on new material and published records, with discussion of morphological characters for species distinction and implications for ecology and vector roles of such species. Now these and other members of the Leucosphyrus Group are identifiable, it should be possible to clarify the medical importance and distribution of each species. Those already regarded as vectors of human malaria are: An. baimaii[Bangladesh, China (Yunnan), India (Andamans, Assam, Meghalaya, West Bengal), Myanmar, Thailand]; An. latens[Borneo (where it also transmits Bancroftian filariasis), peninsular Malaysia, Thailand]; probably An. cracens (Sumatra

  19. Bacteria attenuation by iron electrocoagulation governed by interactions between bacterial phosphate groups and Fe(III) precipitates

    NARCIS (Netherlands)

    Delaire, Caroline; van Genuchten, Case M.; Amrose, Susan E.; Gadgil, Ashok J.

    2016-01-01

    Iron electrocoagulation (Fe-EC) is a low-cost process in which Fe(II) generated from an Fe(0) anode reacts with dissolved O2 to form (1) Fe(III) precipitates with an affinity for bacterial cell walls and (2) bactericidal reactive oxidants. Previous work suggests that Fe-EC is a promising treatment o

  20. Measuring the CCN and IN ability of bacterial isolates: implications for the southeastern United States and Puerto Rico

    Science.gov (United States)

    Purdue, S.; Waters, S.; Konstantinidis, K.; Nenes, A.; DeLeon-Rodriguez, N.

    2015-12-01

    Ice nucleation is an important process in the climate system as it influences global precipitation processes, and can affect the vertical distribution of clouds with effects that both cool and warm the atmosphere. Of the pathways to ice nucleation, immersion mode, which occurs when ice nuclei (IN) particles are surrounded by an aqueous phase that subsequently freezes, dominates primary ice production in mixed-phase clouds. A simple but effective method to study immersion freezing is to utilize a droplet freezing assay (DFA) that consists of an aluminum plate, precisely cooled by a continuous flow of an ethylene glycol-water mixture. Using such a system we study the immersion IN characteristics of bacterial isolates (for temperatures ranging from -15oC to 0oC) isolated from rainwater and air collected in Atlanta, GA and Puerto Rico, over storms throughout the year. Despite their relatively large size and the presence of hydrophilic groups on the outer membranes of many bacteria, it is unclear if bacteria possess an inherent ability to nucleate an aqueous phase (a requirement for immersion freezing) for the wide range of supersaturations found in clouds. For this, we measure the cloud condensation nucleation (CCN) activity of each isolate (over the 0.05% to 0.6% supersaturation range) using a Continuous Flow Streamwise Thermal Gradient CCN Counter. Initial results have shown certain isolates to be very efficient CCN, allowing them to form droplets even for the very low supersaturations found in radiation fogs. In combination, these experiments provide insight into the potential dual-ability of some bacteria, isolated from the southeastern United States and Puerto Rico, to act as both efficient CCN and IN.

  1. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion...... is the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental parameters......, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to significantly...

  2. Bacterial wall products induce downregulation of vascular endothelial growth factor receptors on endothelial cells via a CD14-dependent mechanism: implications for surgical wound healing.

    LENUS (Irish Health Repository)

    Power, C

    2012-02-03

    INTRODUCTION: Vascular endothelial growth factor (VEGF) is a potent mitogenic cytokine which has been identified as the principal polypeptide growth factor influencing endothelial cell (EC) migration and proliferation. Ordered progression of these two processes is an absolute prerequisite for initiating and maintaining the proliferative phase of wound healing. The response of ECs to circulating VEGF is determined by, and directly proportional to, the functional expression of VEGF receptors (KDR\\/Flt-1) on the EC surface membrane. Systemic sepsis and wound contamination due to bacterial infection are associated with significant retardation of the proliferative phase of wound repair. The effects of the Gram-negative bacterial wall components lipopolysaccharide (LPS) and bacterial lipoprotein (BLP) on VEGF receptor function and expression are unknown and may represent an important biological mechanism predisposing to delayed wound healing in the presence of localized or systemic sepsis. MATERIALS AND METHODS: We designed a series of in vitro experiments investigating this phenomenon and its potential implications for infective wound repair. VEGF receptor density on ECs in the presence of LPS and BLP was assessed using flow cytometry. These parameters were assessed in hypoxic conditions as well as in normoxia. The contribution of CD14 was evaluated using recombinant human (rh) CD14. EC proliferation in response to VEGF was quantified in the presence and absence of LPS and BLP. RESULTS: Flow cytometric analysis revealed that LPS and BLP have profoundly repressive effects on VEGF receptor density in normoxic and, more pertinently, hypoxic conditions. The observed downregulation of constitutive and inducible VEGF receptor expression on ECs was not due to any directly cytotoxic effect of LPS and BLP on ECs, as measured by cell viability and apoptosis assays. We identified a pivotal role for soluble\\/serum CD14, a highly specific bacterial wall product receptor, in

  3. The Influence of Pumping on Observed Bacterial Counts in Groundwater Samples: Implications for Sampling Protocol and Water Quality Interpretation

    Science.gov (United States)

    Kozuskanich, J.; Novakowski, K.; Anderson, B.

    2008-12-01

    Drinking water quality has become an important issue in Ontario following the events in Walkerton in 2000. Many rural communities are reliant on private groundwater wells for drinking water, and it is the responsibility of the owner to have the water tested to make sure it is safe for human consumption. Homeowners can usually take a sample to the local health unit for total coliform and E. Coli analysis at no charge to determine if the water supply is being tainted by surface water or fecal matter, both of which could indicate the potential for negative impacts on human health. However, is the sample coming out of the tap representative of what is going on the aquifer? The goal of this study is to observe how bacterial counts may vary during the course of well pumping, and how those changing results influence the assessment of water quality. Multiple tests were conducted in bedrock monitoring wells to examine the influence of pumping rate and pumped volume on observed counts of total coliform, E. Coli, fecal streptococcus, fecal coliform and heterotrophic plate count. Bacterial samples were collected frequently during the course of continuous purging events lasting up to 8 hours. Typical field parameters (temperature, salinity, pH, dissolved oxygen and ORP) were also continuously monitored during the course of each test. Common practice in groundwater studies is to wait until these parameters have stabilized or three well volumes have been removed prior to sampling, to ensure the sample is taken from new water entering the well from the aquifer, rather than the original water stored in the borehole prior to the test. In general, most bacterial counts were low, but did go above the drinking water standard of 0 counts/100mL (total coliform and E. Coli) at times during the tests. Results show the greatest variability in the observed bacterial counts at the onset of pumping prior to the removal of three well volumes. Samples taken after the removal of three well

  4. Associations between ectomycorrhizal fungi and bacterial needle endophytes in Pinus radiata: implications for biotic selection of microbial communities

    Directory of Open Access Journals (Sweden)

    Megan Arlene Rúa

    2016-03-01

    Full Text Available Studies of the ecological and evolutionary relationships between plants and their associated microbes have long been focused on single microbes, or single microbial guilds, but in reality, plants associate with a diverse array of microbes from a varied set of guilds. As such, multitrophic interactions among plant-associated microbes from multiple guilds represent an area of developing research, and can reveal how complex microbial communities are structured around plants. Interactions between coniferous plants and their associated microbes provide a good model system for such studies, as conifers host a suite of microorganisms including mutualistic ectomycorrhizal (ECM fungi and foliar bacterial endophytes. To investigate the potential role ECM fungi play in structuring foliar bacterial endophyte communities, we sampled three isolated, native populations of Monterey pine (Pinus radiata, and used constrained analysis of principal coordinates to relate the community matrices of the ECM fungi and bacterial endophytes. Our results suggest that ECM fungi may be important factors for explaining variation in bacterial endophyte communities but this effect is influenced by population and environmental characteristics, emphasizing the potential importance of other factors — biotic or abiotic — in determining the composition of bacterial communities. We also classified ECM fungi into categories based on known fungal traits associated with substrate exploration and nutrient mobilization strategies since variation in these traits allows the fungi to acquire nutrients across a wide range of abiotic conditions and may influence the outcome of multi-species interactions. Across populations and environmental factors, none of the traits associated with fungal foraging strategy types significantly structured bacterial assemblages, suggesting these ECM fungal traits are not important for understanding endophyte-ECM interactions. Overall, our results suggest

  5. A systematic literature review of the economic implications of acute bacterial skin and skin structure infections (ABSSSIs)

    NARCIS (Netherlands)

    Degener, F.; Ivanescu, C.; Casamayor, M.; Postma, M.

    2015-01-01

    Objectives: During the years, acute bacterial skin and skin structure infections (ABSSSIs) have seen an increase in incidence in many parts of the western world. Additionally, the treatment of ABSSSIs, generally consisting of surgical debridement or drainage and empiric antibiotics in the hospital,

  6. Sensitivity of Francisella tularensis to ultrapure water and deoxycholate: implications for bacterial intracellular growth assay in macrophages

    Science.gov (United States)

    Chalabaev, Sabina; Anderson, Christine A.; Onderdonk, Andrew B.; Kasper, Dennis L.

    2011-01-01

    The ability of Francisella tularensis to replicate in macrophages is critical for its pathogenesis, therefore intracellular growth assays are important tools for assessing virulence. We show that two lysis solutions commonly used in these assays, deionized water and deoxycholate in PBS, lead to highly inaccurate measurements of intracellular bacterial survival. PMID:21420447

  7. Rhizosphere bacterial carbon turnover is higher in nucleic acids than membrane lipids: implications for understanding soil carbon cycling

    Directory of Open Access Journals (Sweden)

    Ashish A. Malik

    2015-04-01

    Full Text Available Using a pulse-chase 13CO2 plant labeling experiment we compared the flow of plant carbon into macromolecular fractions of root-associated soil microorganisms. Time dependent 13C dilution patterns in microbial cellular fractions were used to calculate their turnover time. The turnover times of microbial biomolecules were found to vary: microbial RNA (19 h and DNA (30 h turned over fastest followed by chloroform fumigation extraction-derived soluble cell lysis products (14 d, while phospholipid fatty acids (PLFAs had the slowest turnover (42 d. PLFA/NLFA 13C analyses suggest that both mutualistic arbuscular mycorrhizal and saprophytic fungi are dominant in initial plant carbon uptake. In contrast, high initial 13C enrichment in RNA hints at bacterial importance in initial C uptake due to the dominance of bacterial derived RNA in total extracts of soil RNA. To explain this discrepancy, we observed low renewal rate of bacterial lipids, which may therefore bias lipid fatty acid based interpretations of the role of bacteria in soil microbial food webs. Based on our findings, we question current assumptions regarding plant-microbe carbon flux and suggest that the rhizosphere bacterial contribution to plant assimilate uptake could be higher. This highlights the need for more detailed quantitative investigations with nucleic acid biomarkers to further validate these findings.

  8. Application of Focal Conflict Theory to Psychoeducational Groups: Implications for Process, Content, and Leadership

    Science.gov (United States)

    Champe, Julia; Rubel, Deborah J.

    2012-01-01

    Group psychoeducation is a common group type used for a range of purposes. The literature presents balancing content and process as a challenge for psychoeducational group leaders. While the significance of group psychoeducation is supported, practitioners are given little direction for addressing process in these groups. Focal Conflict Theory…

  9. The Use of Group Work in ESL Classrooms-Discourse Features and Implications

    Institute of Scientific and Technical Information of China (English)

    郭奕奕

    2003-01-01

    Group work has many advantages from language acquisition point of view. However, some teachers are unwilling to introduce group work in their own classroom because group work is very difficult to manage. The author of this essay explores the discourse features of successful and unsuccessful group work using discourse analysis in the hope that the results of this language classroom research can help language teachers gain some insight into the use of group work and make more informed decisions about group work management.

  10. The airway microbiota in cystic fibrosis: a complex fungal and bacterial community--implications for therapeutic management.

    Directory of Open Access Journals (Sweden)

    Laurence Delhaes

    Full Text Available BACKGROUND: Given the polymicrobial nature of pulmonary infections in patients with cystic fibrosis (CF, it is essential to enhance our knowledge on the composition of the microbial community to improve patient management. In this study, we developed a pyrosequencing approach to extensively explore the diversity and dynamics of fungal and prokaryotic populations in CF lower airways. METHODOLOGY AND PRINCIPAL FINDINGS: Fungi and bacteria diversity in eight sputum samples collected from four adult CF patients was investigated using conventional microbiological culturing and high-throughput pyrosequencing approach targeting the ITS2 locus and the 16S rDNA gene. The unveiled microbial community structure was compared to the clinical profile of the CF patients. Pyrosequencing confirmed recently reported bacterial diversity and observed complex fungal communities, in which more than 60% of the species or genera were not detected by cultures. Strikingly, the diversity and species richness of fungal and bacterial communities was significantly lower in patients with decreased lung function and poor clinical status. Values of Chao1 richness estimator were statistically correlated with values of the Shwachman-Kulczycki score, body mass index, forced vital capacity, and forced expiratory volume in 1 s (p = 0.046, 0.047, 0.004, and 0.001, respectively for fungal Chao1 indices, and p = 0.010, 0.047, 0.002, and 0.0003, respectively for bacterial Chao1 values. Phylogenetic analysis showed high molecular diversities at the sub-species level for the main fungal and bacterial taxa identified in the present study. Anaerobes were isolated with Pseudomonas aeruginosa, which was more likely to be observed in association with Candida albicans than with Aspergillus fumigatus. CONCLUSIONS: In light of the recent concept of CF lung microbiota, we viewed the microbial community as a unique pathogenic entity. We thus interpreted our results to highlight the potential

  11. Characterization of archaeal group II chaperonin-ADP-metal fluoride complexes: implications that group II chaperonins operate as a "two-stroke engine".

    Science.gov (United States)

    Iizuka, Ryo; Yoshida, Takao; Ishii, Noriyuki; Zako, Tamotsu; Takahashi, Kazunobu; Maki, Kosuke; Inobe, Tomonao; Kuwajima, Kunihiro; Yohda, Masafumi

    2005-12-01

    Group II chaperonins, found in Archaea and in the eukaryotic cytosol, act independently of a cofactor corresponding to GroES of group I chaperonins. Instead, the helical protrusion at the tip of the apical domain forms a built-in lid of the central cavity. Although many studies on the lid's conformation have been carried out, the conformation in each step of the ATPase cycle remains obscure. To clarify this issue, we examined the effects of ADP-aluminum fluoride (AlFx) and ADP-beryllium fluoride (BeFx) complexes on alpha-chaperonin from the hyperthermophilic archaeum, Thermococcus sp. strain KS-1. Biochemical assays, electron microscopic observations, and small angle x-ray scattering measurements demonstrate that alpha-chaperonin incubated with ADP and BeFx exists in an asymmetric conformation; one ring is open, and the other is closed. The result indicates that alpha-chaperonin also shares the inherent functional asymmetry of bacterial and eukaryotic cytosolic chaperonins. Most interestingly, addition of ADP and BeFx induced alpha-chaperonin to encapsulate unfolded proteins in the closed ring but did not trigger their folding. Moreover, alpha-chaperonin incubated with ATP and AlFx or BeFx adopted a symmetric closed conformation, and its functional turnover was inhibited. These forms are supposed to be intermediates during the reaction cycle of group II chaperonins.

  12. Apparent Thixotropic Properties of Saline/Glycerol Drops with Biotinylated Antibodies on Streptavidin-Coated Glass Slides: Implications for Bacterial Capture on Antibody Microarrays

    Directory of Open Access Journals (Sweden)

    Shu-I Tu

    2009-02-01

    Full Text Available The thixotropic-like properties of saline/glycerol drops, containing biotinylated capture antibodies, on streptavidin-coated glass slides have been investigated, along with their implications for bacterial detection in a fluorescent microarray immunoassay. The thixotropic-like nature of 60:40 saline-glycerol semisolid droplets (with differing amounts of antibodies was observed when bacteria were captured, and their presence detected using a fluorescently-labeled antibody. Semisolid, gel-like drops of biotinylated capture antibody became liquefied and moved, and then returned to semisolid state, during the normal immunoassay procedures for bacterial capture and detection. Streaking patterns were observed that indicated thixotropic-like characteristics, and this appeared to have allowed excess biotinylated capture antibody to participate in bacterial capture and detection. When developing a microarray for bacterial detection, this must be considered for optimization. For example, with the appropriate concentration of antibody (in this study, 0.125 ng/nL, spots with increased diameter at the point of contact printing (and almost no streaking were produced, resulting in a maximal signal. With capture antibody concentrations greater than 0.125 ng/nL, the excess biotinylated capture antibody (i.e., that which was residing in the three-dimensional, semisolid droplet space above the surface was utilized to capture more bacteria. Similarly, when the immunoassay was performed within a hydrophobic barrier (i.e., without a coverslip, brighter spots with increased signal were observed. In addition, when higher concentrations of cells (~108 cells/mL were available for capture, the importance of unbound capture antibody in the semisolid droplets became apparent because washing off the excess, unbound biotinylated capture antibody before the immunoassay was performed reduced the signal intensity by nearly 50%. This reduction in signal was not observed with

  13. Distributional pattern of benthic foraminiferal morpho-groups in the shelf region off Mangalore: Environmental implications

    Digital Repository Service at National Institute of Oceanography (India)

    Khare, N.; Sinha, R.; Rai, A.K.; Nigam, R.

    , the population was further placed into two broad morpho-groups namely, angular-asymmetrical and rounded-symmetrical. The surficial distribution of these groups revealed that angular-asymmetrical forms are abundant in relatively deeper region whereas rounded...

  14. Effect of the pollution level on the functional bacterial groups aiming at degrading bisphenol A and nonylphenol in natural biofilms of an urban river.

    Science.gov (United States)

    Cai, Wei; Li, Yi; Wang, Peifang; Niu, Lihua; Zhang, Wenlong; Wang, Chao

    2016-08-01

    Bisphenol A (BPA) and 4-nonylphenol (NP) are ubiquitous pollutants with estrogenic activity in aquatic environment and have attracted global concern due to their disruption of endocrine systems. This study investigated the spatial distribution characteristics of the bacterial groups involved in the degradation of BPA and NP within biofilms in an urban river using terminal restriction fragment length polymorphism based on 16S rRNA gene sequences. The effects of the pollution level and water parameters on these groups were also assessed. Hierarchical cluster analysis grouped the sampling sites into three clusters reflecting their varying nutrient pollution levels of relatively slight pollution (SP), moderate pollution (MP), and high pollution (HP) based on water quality data and Environmental Quality Standard for Surface Water of China (GB3838-2002). The BPA and NP concentration in river water ranged from 0.8 to 77.5 and 10.2 to 162.9 ng L(-1), respectively. Comamonadaceae, Pseudomonadaceae, Alcaligenaceae, Bacillaceae, Sphingomonadacea, Burkholderiaceae, and Rhizobiaceae were the dominant bacterial taxa involved in BPA and NP degradation, comprising an average of 9.8, 8.1, 7.6, 6.7, 6.2, 4.1, and 2.8 % of total sequences, respectively. The total abundance of these groups showed a slight upward trend and subsequently rapidly decreased with increasing pollution levels. The average proportion of Comamonadaceae in MP river sections was almost 1.5-2 times than that in SP or HP one. The distribution of functional groups was found related to environmental variables, especially pH, conductivity, ammonium nitrogen (NH3-N), and BPA. The abundance of Comamonadaceae and Rhizobiaceae was both closely related to higher values of pH and conductivity as well as lower concentrations of NP and BPA. Alcaligenaceae and Pseudomonadaceae were associated with higher concentrations of TP and CODMn and inversely correlated with DO concentration. This study might provide effective data on

  15. Ice cover extent drives phytoplankton and bacterial community structure in a large north-temperate lake: implications for a warming climate.

    Science.gov (United States)

    Beall, B F N; Twiss, M R; Smith, D E; Oyserman, B O; Rozmarynowycz, M J; Binding, C E; Bourbonniere, R A; Bullerjahn, G S; Palmer, M E; Reavie, E D; Waters, Lcdr M K; Woityra, Lcdr W C; McKay, R M L

    2016-06-01

    Mid-winter limnological surveys of Lake Erie captured extremes in ice extent ranging from expansive ice cover in 2010 and 2011 to nearly ice-free waters in 2012. Consistent with a warming climate, ice cover on the Great Lakes is in decline, thus the ice-free condition encountered may foreshadow the lakes future winter state. Here, we show that pronounced changes in annual ice cover are accompanied by equally important shifts in phytoplankton and bacterial community structure. Expansive ice cover supported phytoplankton blooms of filamentous diatoms. By comparison, ice free conditions promoted the growth of smaller sized cells that attained lower total biomass. We propose that isothermal mixing and elevated turbidity in the absence of ice cover resulted in light limitation of the phytoplankton during winter. Additional insights into microbial community dynamics were gleaned from short 16S rRNA tag (Itag) Illumina sequencing. UniFrac analysis of Itag sequences showed clear separation of microbial communities related to presence or absence of ice cover. Whereas the ecological implications of the changing bacterial community are unclear at this time, it is likely that the observed shift from a phytoplankton community dominated by filamentous diatoms to smaller cells will have far reaching ecosystem effects including food web disruptions.

  16. [An in vitro study of the action of kola nitida on bacterial strains implicated in dental caries and periodontal diseases].

    Science.gov (United States)

    Kamagate, A; Attoli, L; Kone, D; Ly, Bakayoko; Brou, E; Sixou, M

    2002-06-01

    The Nitida Kola is a substance extracted from the kolanut. In West Africa its use by chewing is widespread among the Manding people. It's said to have tonic, stimulant and aphrodisiac characteristics and even recent studies have shown that it has antibacterial characteristics. The aim of this study is to make an estimation of the Nitida Kola's effects on different bacterial species involved in the two main oral and dental pathologies (teeth decays and periodontal illnesses). The obtained results indicate that the kola extract is not effectual against the tried-out bacteria at regular dose used by chewing.

  17. Possible implication of bacterial infection in acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Shigeo eFuji

    2014-04-01

    Full Text Available Graft-versus-host disease (GVHD is still one of the major causes of morbidity and mortality in allogeneic hematopoietic stem cell transplantation (HSCT. In the pathogenesis of acute GVHD, it has been established that donor-derived T cells activated in the recipient play a major role in GVHD in initiation and maintenance within an inflammatory cascade. To reduce the risk of GVHD, intensification of GVHD prophylaxis like T cell depletion is effective, but it inevitably increases the risk of infectious diseases and abrogates beneficial graft-versus-leukemia effects. Although various cytokines are considered to play an important role in the pathogenesis of GVHD, GVHD initiation is such a complex process that cannot be prevented by means of single inflammatory cytokine inhibition. Thus, efficient methods to control the whole inflammatory milieu both on cellular and humoral view are needed. In this context, infectious diseases can theoretically contribute to an elevation of inflammatory cytokines after allogeneic HSCT and activation of various subtypes of immune effector cells, which might in summary lead to an aggravation of acute GVHD. The appropriate treatments or prophylaxis of bacterial infection during the early phase after allogeneic HSCT might be beneficial to reduce not only infectious-related but also GVHD-related mortality. Here, we aim to review the literature addressing the interactions of bacterial infections and GVHD after allogeneic HSCT.

  18. Possible Implication of Bacterial Infection in Acute Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation

    Science.gov (United States)

    Fuji, Shigeo; Kapp, Markus; Einsele, Hermann

    2014-01-01

    Graft-versus-host disease (GVHD) is still one of the major causes of morbidity and mortality in allogeneic hematopoietic stem cell transplantation (HSCT). In the pathogenesis of acute GVHD, it has been established that donor-derived T-cells activated in the recipient play a major role in GVHD in initiation and maintenance within an inflammatory cascade. To reduce the risk of GVHD, intensification of GVHD prophylaxis like T-cell depletion is effective, but it inevitably increases the risk of infectious diseases and abrogates beneficial graft-versus-leukemia effects. Although various cytokines are considered to play an important role in the pathogenesis of GVHD, GVHD initiation is such a complex process that cannot be prevented by means of single inflammatory cytokine inhibition. Thus, efficient methods to control the whole inflammatory milieu both on cellular and humoral view are needed. In this context, infectious diseases can theoretically contribute to an elevation of inflammatory cytokines after allogeneic HSCT and activation of various subtypes of immune effector cells, which might in summary lead to an aggravation of acute GVHD. The appropriate treatments or prophylaxis of bacterial infection during the early phase after allogeneic HSCT might be beneficial to reduce not only infectious-related but also GVHD-related mortality. Here, we aim to review the literature addressing the interactions of bacterial infections and GVHD after allogeneic HSCT. PMID:24795865

  19. The Nonsignificant Impact of an Agenda Setting Treatment for Groups: Implications for Future Research and Practice

    Science.gov (United States)

    Bridbord, Karen; DeLucia-Waack, Janice L.; Jones, Edlyn; Gerrity, Deborah A.

    2004-01-01

    This pilot study compared the effect of two writing techniques, Agenda Setting and Group Focus, to a cognitive technique, reading process notes at the start of a group session, to examine their impact on social climate, member involvement, and behavior. Theoretically an intervention that helps members to focus directly on their goals and potential…

  20. Acute Hemolytic Transfusion Reaction in a Patient with Bombay Phenotype: Implications for ABO Grouping.

    Science.gov (United States)

    Malhotra, Sheetal; Dhawan, Hari Krishan; Jain, Ashish; Sachdev, Suchet; Marwaha, Neelam

    2014-09-01

    Bombay blood group is a rare phenotype that is characterized serologically by absence of H, A and B antigens on red cell surface and presence of corresponding antibodies in the serum. We report a case of 45-year old patient having Bombay blood group phenotype who experienced an acute reaction due to transfusion of mismatched blood unit.

  1. Item Construction Using Reflective, Formative, or Rasch Measurement Models: Implications for Group Work

    Science.gov (United States)

    Peterson, Christina Hamme; Gischlar, Karen L.; Peterson, N. Andrew

    2017-01-01

    Measures that accurately capture the phenomenon are critical to research and practice in group work. The vast majority of group-related measures were developed using the reflective measurement model rooted in classical test theory (CTT). Depending on the construct definition and the measure's purpose, the reflective model may not always be the…

  2. Life of Pizza Pie: The Implications of Sub-Group Comparisons in Education

    Science.gov (United States)

    Thomas, Tara N.

    2013-01-01

    Current educational statistics have pitted subgroups against one another without consideration of the actual population sizes of each group. This paper is intended to provided a clearer understanding of the current usage of sub-group comparisons in American education. (Contains 4 figures.)

  3. Insights into the history of a bacterial group II intron remnant from the genomes of the nitrogen-fixing symbionts Sinorhizobium meliloti and Sinorhizobium medicae.

    Science.gov (United States)

    Toro, N; Martínez-Rodríguez, L; Martínez-Abarca, F

    2014-10-01

    Group II introns are self-splicing catalytic RNAs that act as mobile retroelements. In bacteria, they are thought to be tolerated to some extent because they self-splice and home preferentially to sites outside of functional genes, generally within intergenic regions or in other mobile genetic elements, by mechanisms including the divergence of DNA target specificity to prevent target site saturation. RmInt1 is a mobile group II intron that is widespread in natural populations of Sinorhizobium meliloti and was first described in the GR4 strain. Like other bacterial group II introns, RmInt1 tends to evolve toward an inactive form by fragmentation, with loss of the 3' terminus. We identified genomic evidence of a fragmented intron closely related to RmInt1 buried in the genome of the extant S. meliloti/S. medicae species. By studying this intron, we obtained evidence for the occurrence of intron insertion before the divergence of ancient rhizobial species. This fragmented group II intron has thus existed for a long time and has provided sequence variation, on which selection can act, contributing to diverse genetic rearrangements, and to generate pan-genome divergence after strain differentiation. The data presented here suggest that fragmented group II introns within intergenic regions closed to functionally important neighboring genes may have been microevolutionary forces driving adaptive evolution of these rhizobial species.

  4. Overlapping two self-avoiding polymers in a closed cylindrical pore: Implications for chromosome segregation in a bacterial cell

    Science.gov (United States)

    Jung, Youngkyun; Ha, Bae-Yeun

    2010-11-01

    We study the spatial organization and segregation of two self-avoiding polymers trapped inside a closed cylindrical pore. Using molecular-dynamics simulations, we show how confinement shapes the chains, especially their mutual (entropic) force, chain miscibility, and segregation dynamics. Under strong confinement, the chains are shown to repel more strongly and thus segregate better if they are shorter and the confining space is more asymmetric, in contrast to the spherically confined case, where nonlinear chain topology is required for chain partitioning in equilibrium. When applied to bacterial chromosomes, our results imply that chromosome miscibility depends on how they are compacted and structured inside the cell (by proteins and supercoiling). Finally, longitudinal confinement is shown to have nontrivial effects on segregation dynamics by randomizing and thus slowing down the segregation process, which would otherwise be assisted with entropic forces.

  5. Adsorption to metal oxides of the Pseudomonas aeruginosa siderophore pyoverdine and implications for bacterial biofilm formation on metals.

    Science.gov (United States)

    Upritchard, Hamish G; Yang, Jing; Bremer, Philip J; Lamont, Iain L; McQuillan, A James

    2007-06-19

    The initiation of biofilm formation is poorly understood, and in particular, the contribution of chemical bond formation between bacterial cells and metal surfaces has received little attention. We have previously used in situ infrared spectroscopy to show, during the initial stages of Pseudomonas aeruginosa biofilm formation, the formation of coordinate covalent bonds between titanium dioxide particle films and pyoverdine, a mixed catecholate and hydroxamate siderophore. Here we show using infrared spectroscopy that pyoverdine can also form covalent bonds with particle films of Fe2O3, CrOOH, and AlOOH. Adsorption to the metal oxides through the catechol-like 2,3-diamino-6,7-dihydroxyquinoline part of pyoverdine was most evident in the infrared spectrum of the adsorbed pyoverdine molecule. Weaker infrared absorption bands that are consistent with the hydroxamic acids of pyoverdine binding covalently to TiO2, Fe2O3, and AlOOH surfaces were also observed. The adsorption of pyoverdine to TiO2 and Fe2O3 surfaces showed a pH dependence that is indicative of the dominance of the catechol-like ligand of pyoverdine. Infrared absorption bands were also evident for pyoverdine associated with the cells of P. aeruginosa on TiO2 and Fe2O3 surfaces and were notably absent for genetically modified cells unable to synthesize or bind pyoverdine at the cell surface. These studies confirm the generality of pyoverdine-metal bond formation and suggest a wider involvement of siderophores in bacterial biofilm initiation on metals.

  6. Conformational differences between the methoxy groups of QA and QB site ubisemiquinones in bacterial reaction centers: a key role for methoxy group orientation in modulating ubiquinone redox potential.

    Science.gov (United States)

    Taguchi, Alexander T; O'Malley, Patrick J; Wraight, Colin A; Dikanov, Sergei A

    2013-07-09

    Ubiquinone is an almost universal, membrane-associated redox mediator. Its ability to accept either one or two electrons allows it to function in critical roles in biological electron transport. The redox properties of ubiquinone in vivo are determined by its environment in the binding sites of proteins and by the dihedral angle of each methoxy group relative to the ring plane. This is an attribute unique to ubiquinone among natural quinones and could account for its widespread function with many different redox complexes. In this work, we use the photosynthetic reaction center as a model system for understanding the role of methoxy conformations in determining the redox potential of the ubiquinone/semiquinone couple. Despite the abundance of X-ray crystal structures for the reaction center, quinone site resolution has thus far been too low to provide a reliable measure of the methoxy dihedral angles of the primary and secondary quinones, QA and QB. We performed 2D ESEEM (HYSCORE) on isolated reaction centers with ubiquinones (13)C-labeled at the headgroup methyl and methoxy substituents, and have measured the (13)C isotropic and anisotropic components of the hyperfine tensors. Hyperfine couplings were compared to those derived by DFT calculations as a function of methoxy torsional angle allowing estimation of the methoxy dihedral angles for the semiquinones in the QA and QB sites. Based on this analysis, the orientation of the 2-methoxy groups are distinct in the two sites, with QB more out of plane by 20-25°. This corresponds to an ≈50 meV larger electron affinity for the QB quinone, indicating a substantial contribution to the experimental difference in redox potentials (60-75 mV) of the two quinones. The methods developed here can be readily extended to ubiquinone-binding sites in other protein complexes.

  7. Conformational differences between the methoxy groups of QA and QB site ubisemiquinones in bacterial reaction centers: a key role for methoxy group orientation in modulating ubiquinone redox potential†

    Science.gov (United States)

    Taguchi, Alexander T.; O'Malley, Patrick J.; Wraight, Colin A.; Dikanov, Sergei A.

    2013-01-01

    Ubiquinone is an almost universal, membrane-associated redox mediator. Its ability to accept either one or two electrons allows it to function in critical roles in biological electron transport. The redox properties of ubiquinone in vivo are determined by its environment in the binding sites of proteins and by the dihedral angle of each methoxy group relative to the ring plane. This is an attribute unique to ubiquinone among natural quinones and could account for its widespread function with many different redox complexes. In this work, we use the photosynthetic reaction center as a model system for understanding the role of methoxy conformations in determining the redox potential of the ubiquinone/semiquinone couple. Despite the abundance of X-ray crystal structures for the reaction center, quinone site resolution has thus far been too low to provide a reliable measure of the methoxy dihedral angles of the primary and secondary quinones, QA and QB. We performed 2D ESEEM (HYSCORE) on isolated reaction centers with ubiquinones 13C-labeled at the headgroup methyl and methoxy substituents, and have measured the 13C isotropic and anisotropic components of the hyperfine tensors. Hyperfine couplings were compared to those derived by DFT calculations as a function of methoxy torsional angle allowing estimation of the methoxy dihedral angles for the semiquinones in the QA and QB sites. Based on this analysis, the orientation of the 2-methoxy groups are distinct in the two sites, with QB more out of plane by 20-30°. This corresponds to an ≈50 meV larger electron affinity for the QB quinone, indicating a substantial contribution to the experimental difference in redox potentials (60-75 mV) of the two quinones. The methods developed here can be readily extended to ubiquinone-binding sites in other protein complexes. PMID:23745576

  8. Taxonomic precision of different hypervariable regions of 16S rRNA gene and annotation methods for functional bacterial groups in biological wastewater treatment.

    Directory of Open Access Journals (Sweden)

    Feng Guo

    Full Text Available High throughput sequencing of 16S rRNA gene leads us into a deeper understanding on bacterial diversity for complex environmental samples, but introduces blurring due to the relatively low taxonomic capability of short read. For wastewater treatment plant, only those functional bacterial genera categorized as nutrient remediators, bulk/foaming species, and potential pathogens are significant to biological wastewater treatment and environmental impacts. Precise taxonomic assignment of these bacteria at least at genus level is important for microbial ecological research and routine wastewater treatment monitoring. Therefore, the focus of this study was to evaluate the taxonomic precisions of different ribosomal RNA (rRNA gene hypervariable regions generated from a mix activated sludge sample. In addition, three commonly used classification methods including RDP Classifier, BLAST-based best-hit annotation, and the lowest common ancestor annotation by MEGAN were evaluated by comparing their consistency. Under an unsupervised way, analysis of consistency among different classification methods suggests there are no hypervariable regions with good taxonomic coverage for all genera. Taxonomic assignment based on certain regions of the 16S rRNA genes, e.g. the V1&V2 regions - provide fairly consistent taxonomic assignment for a relatively wide range of genera. Hence, it is recommended to use these regions for studying functional groups in activated sludge. Moreover, the inconsistency among methods also demonstrated that a specific method might not be suitable for identification of some bacterial genera using certain 16S rRNA gene regions. As a general rule, drawing conclusions based only on one sequencing region and one classification method should be avoided due to the potential false negative results.

  9. Systematic biases in group decision-making: implications for patient safety.

    Science.gov (United States)

    Mannion, Russell; Thompson, Carl

    2014-12-01

    Key decisions in modern health care systems are often made by groups of people rather than lone individuals. However, group decision-making can be imperfect and result in organizational and clinical errors which may harm patients-a fact highlighted graphically in recent (and historical) health scandals and inquiries such as the recent report by Sir Robert Francis into the serious failures in patient care and safety at Mid Staffordshire Hospitals NHS Trust in the English NHS. In this article, we draw on theories from organization studies and decision science to explore the ways in which patient safety may be undermined or threatened in health care contexts as a result of four systematic biases arising from group decision-making: 'groupthink', 'social loafing', 'group polarization' and 'escalation of commitment'. For each group bias, we describe its antecedents, illustrate how it can impair group decisions with regard to patient safety, outline a range of possible remedial organizational strategies that can be used to attenuate the potential for adverse consequences and look forward at the emerging research agenda in this important but hitherto neglected area of patient safety research.

  10. The Fossils in Shangxi Group and Its Implication for Tectonics, Southern Anhui, China

    Institute of Scientific and Technical Information of China (English)

    徐树桐; 陈冠宝; 陶正; 石永红; 孙枢; Kenneth J.Hsu; 尹磊明; 欧阳舒; 廖卓庭

    1994-01-01

    The Shangxi Group is the local name in southern Anhui Province and it is believed to be the equivalence of the well-known Banxi Group in Hunan Province, southern China. So the area occupied by the Shangxi Group was regarded as a part of the "Jiangnan old land" of Presinian till it was challenged by the present authors years ago. After we postulated that there may be some strata of Palaeozoic Era in Shangxi Group, some microfossils and then macrofossils of Palaeozoic were found in some part of it. The macrof os-sils, Lingula sp. , Conulariid and the microfossils indicate that most units of the Shangxi Group are Palaeozoic strata. Based on the discovery of these fossils and the recognition of the tectonic-setting of the different tectono-petrologic units in the Shangxi Group, three different stratigraphic sequences (island-arc volcanics, back-arc sediments and the cover of passive margin of Yangtze Continental Plate) are established and the tectonic evolution of them is postulated in the present paper. Al

  11. The Lifetime of FRIIs in Groups and Clusters: Implications for Radio-Mode Feedback

    CERN Document Server

    Bird, Jonathan C; Kaiser, Christian R

    2007-01-01

    We determine the maximum lifetime t_max of 58 FRII radio jets found in 29 central group galaxies from cross correlation of the Berlind SDSS group catalog with the VLA FIRST survey. Mock catalogs of FRII sources were produced to match the selection criteria of FIRST and the redshift distribution of our parent sample, while an analytical model was used to calculate source sizes and luminosities. The maximum lifetime of FRII jets was then determined via a comparison of the observed and model projected length distributions. We estimate the average FRII lifetime is 1.2x10^7 years and the duty cycle is ~7x10^8 years. Degeneracies between t_max and the model parameters: jet power distribution, axial ratio, energy injection index, and ambient density introduce at most a factor of two uncertainty in our lifetime estimate. The radio active galactic nuclei (AGN) fraction in central group galaxies was calculated as a function of several group and host galaxy properties. We find greater group galaxy number, redder central...

  12. Exon sequence requirements for excision in vivo of the bacterial group II intron RmInt1

    Directory of Open Access Journals (Sweden)

    Toro Nicolás

    2011-05-01

    Full Text Available Abstract Background Group II intron splicing proceeds through two sequential transesterification reactions in which the 5' and 3'-exons are joined together and the lariat intron is released. The intron-encoded protein (IEP assists the splicing of the intron in vivo and remains bound to the excised intron lariat RNA in a ribonucleoprotein particle (RNP that promotes intron mobility. Exon recognition occurs through base-pairing interactions between two guide sequences on the ribozyme domain dI known as EBS1 and EBS2 and two stretches of sequence known as IBS1 and IBS2 on the 5' exon, whereas the 3' exon is recognized through interaction with the sequence immediately upstream from EBS1 [(δ-δ' interaction (subgroup IIA] or with a nucleotide [(EBS3-IBS3 interaction (subgroup IIB and IIC] located in the coordination-loop of dI. The δ nucleotide is involved in base pairing with another intron residue (δ' in subgroup IIB introns and this interaction facilitates base pairing between the 5' exon and the intron. Results In this study, we investigated nucleotide requirements in the distal 5'- and 3' exon regions, EBS-IBS interactions and δ-δ' pairing for excision of the group IIB intron RmInt1 in vivo. We found that the EBS1-IBS1 interaction was required and sufficient for RmInt1 excision. In addition, we provide evidence for the occurrence of canonical δ-δ' pairing and its importance for the intron excision in vivo. Conclusions The excision in vivo of the RmInt1 intron is a favored process, with very few constraints for sequence recognition in both the 5' and 3'-exons. Our results contribute to understand how group II introns spread in nature, and might facilitate the use of RmInt1 in gene targeting.

  13. Phylogenetic relationships within the Callicebus cupreus species group (Pitheciidae: Primates): Biogeographic and taxonomic implications.

    Science.gov (United States)

    Hoyos, Manuel; Bloor, Paul; Defler, Thomas; Vermeer, Jan; Röhe, Fabio; Farias, Izeni

    2016-09-01

    The genus Callicebus (Thomas, 1903) is one of the most diverse of Neotropical primate genera and the only extant member of the Callicebinae subfamily. It has a widespread distribution from Colombia to Brazil, Bolivia, Peru and northern Paraguay. Coat colouring and colour pattern vary substantially within the genus, and this has led to the description of numerous species and subspecies, as well as numerous species groups. However, a lack of molecular phylogenetic analyses on the genus means that phylogenetic relationships and biogeographic history of species are poorly understood. Here, we examined phylogenetic relationships and patterns of diversification within the Callicebus cupreus species Group (sensu Kobayashi, 1995) using complete mitochondrial DNA cytochrome b gene sequence. Analyses indicate that the Callicebus cupreus Group underwent recent and extensive diversification. The common ancestor appears to have emerged some 2.3 million years ago (Ma) from a centre of origin in the western Amazon region, followed by diversification of the group between about 1.5 and 1.2Ma. Phylogenetic analyses were able to recover most previously described species (including the recently described Colombian endemic Callicebus caquetensis). However, there are some notable inconsistences between the obtained phylogeny and current taxonomy. Some previously recognized taxa were not separated by our data (e.g., Callicebus caligatus and Callicebus dubius), while currently unrecognized species diversity was uncovered within C. cupreus in the form of two divergent lineages: one of which exhibited greater phylogenetic similarity to species from the C. moloch Group. Based on the present study, we challenge current taxonomic arrangements for the C. cupreus species Group and call for a thorough taxonomic revision within the genus Callicebus.

  14. Rayleigh wave group velocity tomography of Gujarat region, Western India and its implications to mantle dynamics

    Science.gov (United States)

    de Lorenzo, Salvatore; Michele, Maddalena; Emolo, Antonio; Tallarico, Andrea

    2017-02-01

    In the present study, fundamental Rayleigh waves with varying period from 10 to 80 s are used to obtain group velocity maps in the northwest Deccan Volcanic Province of India. About 350 paths are obtained using 53 earthquakes (4.8 ≤ M ≥ 7.9) recorded by the SeisNetG (Seismic Network of Gujarat). Individual dispersion curves of group velocity of Rayleigh wave for each source-station path are estimated using multiple filter technique. These curves are used to determine lateral distribution of Rayleigh wave group velocity by tomographic inversion method. Our estimated Rayleigh group velocity at varying depths showed conspicuous corroboration with three tectonic blocks [Kachchh Rift Basin (KRB), Saurashtra Horst (SH), and Mainland Gujarat (MG)] in the region. The seismically active KRB with a thicker crust is characterized as a low velocity zone at a period varying from 10 to 30 s as indicative of mantle downwarping or sagging of the mantle beneath the KRB, while the SH and MG are found to be associated with higher group velocities, indicating the existence of the reduced crustal thickness. The trend of higher group velocity was found prevailed adjacent to the Narmada and Cambay rift basins that also correspond to the reduced crust, suggesting the processes of mantle upwarping or uplifting due to mantle upwelling. The low velocities at periods longer than 40 s beneath the KRB indicate thicker lithosphere. The known Moho depth correlates well with the observed velocities at a period of about 30 s in the Gujarat region. Our estimates of relatively lower group velocities at periods varying from 70 to 80 s may correspond to the asthenospheric flow beneath the region. It is interesting to image higher group velocity for the thinner crust beneath the Arabian Sea adjacent to the west coast of Gujarat at the period of 40 s that may correspond to the upwarped or upwelled mantle beneath the Arabian Sea. Our results have better resolution estimated by a radius of equivalent

  15. Refined stratigraphy and its paleogeographic implication of the Mungyeong Group (Cambrian-Ordovician), Korea

    Science.gov (United States)

    Kim, Inhye; Kwon, Yoojin; Kwon, Yikyun

    2016-04-01

    The Mungyeong Group is a typical lower Paleozoic carbonate-dominated succession regarded as a lithologic subunit of the Joseon Supergroup in the mid-eastern part of the Korean peninsula. This succession was strongly affected by a series of diagenetic processes and tectonic deformation, so it is not easy to realize its sedimentary fabric and structure on outcrops. In addition, due to rare occurrence of fossils, its biostratigraphic information has been restricted. As a result, this group has exposed a lot of debates on its stratigraphy and consequently has failed to establish stratigraphy until now. Through the detailed outcrop description and geologic mapping, this study recognized two lithologically-distinct basin fills (western Gaeun and eastern Hogye basins) suggesting a refined lithostratigraphic framework on the group. The Gaeun basin is filled by the mixed carbonate-siliciclastic succession (Gaeun Subgroup) of the Mungyeong Group, comprising six lithologic formations: Gurangri, Maseong, Hanaeri, Seokgyori, Jeongri and Dotan formation in ascending order. The basal Gurangri Formation is the siliciclastic-dominated unit, containing abundant lower Paleozoic trilobite fossils, conformably overlain by other carbonate-dominated successions characterized by repetitions of limestone and marlstone with intercalations of dolostone beds. On the other hand, the Hogye Subgroup occurs in the eastern basin, divided into five lithostatigraphic units: Gadori, Seonamri, Urori, Yugok and Byeolamri formations in ascending order. This subgroup consists mainly of severely deformed limestone and dolostone successions, intercalated with shale beds. In the Hogye Subgroup, the basal siliciclastic-dominated succession (like as the Gurangri Formation in the Gaeun Subgroup) is not present. This study reveals that the Gaeun and Hogye subgroups in the Mungyeong Group have a distinctive lithology and stratigraphy with each other and compared with the adjacent Yeongweol and Taebaek groups

  16. Group A rotavirus and bacterial agents associated with diarrhoea-induced hospitalisations in children below 5 years of age in Jammu

    Directory of Open Access Journals (Sweden)

    S Gazal

    2014-01-01

    Full Text Available Out of 210 faecal samples collected from children below 5 years attending different hospitals in Jammu and exhibiting clinical signs of diarrhoea, 41.9% samples were found positive for group A rotavirus by RNA-PAGE. Escherichia coli isolated in the study belonged to nine serogroups, out of which O69 was most frequent, being present in 12.38% samples. E. coli serogroups well recognised as enteropathogens viz. O69, O20 and O153 were present in 27.6% samples. Other bacterial pathogens associated with diarrhoea were present in 8.09% samples, out of which Shigella spp. was found in 4.76% samples followed by Salmonella spp. (2.38% and Pseudomonas spp. (0.95%.

  17. Guidelines for the diagnosis and antimicrobial therapy of canine superficial bacterial folliculitis (Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases)

    DEFF Research Database (Denmark)

    Hillier, Andrew; Lloyd, David H.; Weese, J. Scott

    2014-01-01

    BACKGROUND: Superficial bacterial folliculitis (SBF) is usually caused by Staphylococcus pseudintermedius and routinely treated with systemic antimicrobial agents. Infection is a consequence of reduced immunity associated with alterations of the skin barrier and underlying diseases that may be di...... will improve antimicrobial use and reduce selection of MRSP and other multidrug-resistant bacteria affecting animal and human health....... of an internationally available resource guiding practitioners in the diagnosis, treatment and prevention of SBF. DEVELOPMENT OF THE GUIDELINES: The guidelines were developed by the Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases, with consultation and advice...... on infection control. Guidance is given for topical and systemic modalities, including approaches suitable for MRSP. Systemic drugs are classified in three tiers. Tier one drugs are used when diagnosis is clear cut and risk factors for antimicrobial drug resistance are not present. Otherwise, tier two drugs...

  18. New Tools for Examining Undergraduate Students' STEM Stereotypes: Implications for Women and Other Underrepresented Groups

    Science.gov (United States)

    Nassar-McMillan, Sylvia C.; Wyer, Mary; Oliver-Hoyo, Maria; Schneider, Jennifer

    2011-01-01

    Although both domestic U.S. and international statistics on population demographics within science, technology, engineering, and mathematics (STEM) fields indicate overall gains and more even representation among various groups, caution must be taken to interpret these gains as suggesting blanket improvement in underrepresentation issues. When…

  19. Promoting Resilience through Social Work Practice with Groups: Implications for the Practice and Field Curricula

    Science.gov (United States)

    Gitterman, Alex; Knight, Carolyn

    2016-01-01

    The realities of contemporary social work practice often push social workers toward a deficit-focused orientation. The article begins with an overview of the major tenets of resiliency and adversarial growth theories and related research findings. We suggest that the group modality epitomizes the application of resiliency theory and adversarial…

  20. U-Pb (Zircon Ages of Metavolcanic Rocks From the Itaiacoca Group: Tectonic Implications

    Directory of Open Access Journals (Sweden)

    Oswaldo Siga Jr.

    2003-08-01

    Full Text Available The main aim of this work is to present and discuss the U-Pb ages obtained for zircon grains from metavolcanic rocks of theItaiacoca Group. The Itaiacoca Group is a metavolcano-sedimentary sequence, which occurs as a narrow belt between theCunhaporanga granitic batholith to the northwest and the Itapirapuã shear zone to the south and southwest, which separates thesequence from the Três Córregos granite batholith and metasedimentary rocks of the Açungui Group. Geological studies of thesouthern part of the Itaiacoca belt led to the recognition of three units, represented (from base to top by metawackes with animportant volcanic component, metacarbonate, and metapelitic and metapsammitic rocks. The U-Pb geochronological analyses ofzircon grains from two outcrops of metavolcanic rocks yield ages of 628 ± 18 Ma (SHRIMP and 636 ± 30 Ma (conventional multigrainanalyses. These ages are quite close to the metamorphic event recorded in the Itaiacoca Group (628 – 610 Ma, suggesting ashort interval between the formation of these rocks and closure of the basin. Furthermore, this volcanism is very close to the age offormation of the Três Córregos (630 Ma and Cunhaporanga (590 Ma granitic batholiths, admitted as associated with a probablemagmatic arc. Such an isotopic pattern characterizes a Neoproterozoic tectonic scenario involving volcanism, metamorphism andgranitic plutonism, interpreted here as the final stages in the evolution of the Itaiacoca Basin.

  1. How group factors affect adolescent change talk and substance use outcomes: implications for motivational interviewing training.

    Science.gov (United States)

    Osilla, Karen Chan; Ortiz, J Alexis; Miles, Jeremy N V; Pedersen, Eric R; Houck, Jon M; D'Amico, Elizabeth J

    2015-01-01

    Clients who verbalize statements arguing for change (change talk [CT]) in psychotherapy are more likely to decrease alcohol and other drug use (AOD) compared with clients who voice statements in opposition of change (sustain talk [ST]). Little is known about how CT and ST are expressed in groups in which adolescents may vary in their AOD use severity and readiness to change. First, we examined how session content was associated with CT/ST, and then we looked at whether different subtypes of CT/ST were associated with subsequent AOD outcomes 3 months later. Audio recordings (N = 129 sessions) of a 6-session group motivational interviewing (MI) intervention, Free Talk, were coded. Session content was not associated with CT; however, some session content was associated with higher percentages of ST (e.g., normative feedback). Subtypes of CT (Commitment and Reason) were associated with improved AOD outcomes, whereas Ability subtype remarks were related to increased marijuana use, intentions, and consequences. Findings offer helpful guidance for clinical training and narrow in on the type of CT to try to elicit in Group MI sessions. Regardless of session content, adolescents can benefit from hearing CT during the group.

  2. Treatment fairness and group norms in times of turmoil : Implications for employee well-beini

    NARCIS (Netherlands)

    Miles, P.

    2010-01-01

    Employee well-being is important for individual employees and for the organizations they work for. However, current difficult economic times cause employees to experience unfavorable conditions (e.g., uncertainty, unfair outcomes and low cohesive groups) and this thesis attempts to provide organizat

  3. Focus Group Research on the Implications of Adopting the Unified English Braille Code

    Science.gov (United States)

    Wetzel, Robin; Knowlton, Marie

    2006-01-01

    Five focus groups explored concerns about adopting the Unified English Braille Code. The consensus was that while the proposed changes to the literary braille code would be minor, those to the mathematics braille code would be much more extensive. The participants emphasized that "any code that reduces the number of individuals who can access…

  4. Evolution and function of fossoriality in the carnivora: implications for group-living

    Directory of Open Access Journals (Sweden)

    Michael James Noonan

    2015-10-01

    Full Text Available The societies of group-living carnivores that neither hunt nor interact cooperatively may arise due to ecological drivers and/or constraints. In this study we evaluate whether group-living may be intrinsically associated with fossoriality; a link that is well supported in other taxa, but hitherto under-evaluated in the Carnivora. We make two over-arching predictions: i that fossoriality will be associated with carnivoran sociality; and ii that this association will be most evident in those species making extended use of subterranean dens. From a meta-analysis of key behavioural, ecological, ontological, and trophic traits, we demonstrate that three quarters of carnivore species exhibit some reliance on underground dens. Congruence between life-history traits and metrics of fossoriality evidenced that: 1 there are phylogenetic, and morphological constraints on wholly fossorial life-histories; 2 fossoriality correlated positively with the extent of offspring altriciality, linked to the use of natal dens; 3 burrow use increased with latitude; and 4 insectivorous carnivores were more fossorial than predatory carnivores. Corroborating work in the Rodentia, fossorial traits associated strongly with carnivoran group-living tendencies, where species utilising subterranean natal dens are 2.5 times more likely to form groups than those that do not. Furthermore, using comparative analyses, we evidence support for an evolutionary relationship between diet, fossoriality and sociality. We propose that fossorial dens act as a safe haven, promoting fitness benefits, territorial inheritance and cooperative breeding. We conclude that, among smaller (<15kg den-using carnivores, and especially for omnivorous/ insectivorous species for which food resource dispersion is favorable, continued cohabitation at natal dens can promote cohabitation among adults; that is, philopatric benefits leading to (not necessarily cooperative spatial groups.

  5. Cooperation and the evolutionary ecology of bacterial virulence: the Bacillus cereus group as a novel study system.

    Science.gov (United States)

    Raymond, Ben; Bonsall, Michael B

    2013-08-01

    How significant is social evolution theory for the maintenance of virulence in natural populations? We assume that secreted, distantly acting virulence factors are highly likely to be cooperative public goods. Using this assumption, we discuss and critically assess the potential importance of social interactions for understanding the evolution, diversity and distribution of virulence in the Bacillus cereus group, a novel study system for microbial social biology. We conclude that dynamic equilibria in Cry toxin production, as well as strong spatial structure and population bottlenecks in hosts are the main ecological factors maintaining the cooperative secretion of virulence factors and argue that collective action has contributed to the evolution of narrow host range. Non-linearities in the benefits associated with public goods, as well as the lack of private secretion systems in the Firmicutes may also explain the prevalence and importance of distantly acting virulence factors in B. cereus and its relatives.

  6. Physical Implications of the X-ray Properties of Galaxy Groups and Clusters

    CERN Document Server

    Babul, A; Lewis, G F; Poole, G B; Babul, Arif; Balogh, Michael L.; Lewis, Geraint F.; Poole, Gregory B.

    2002-01-01

    Within the standard framework of structure formation, where clusters and groups of galaxies are built up from the merging of smaller systems, the physical properties of the intracluster medium, such as the gas temperature and the total X-ray luminosity, are predicted to possess well defined self-similar scaling relations. Observed clusters and groups, however, show strong deviations from these predicted relations. We argue that these deviations are unlikely to be entirely due to observational biasses; we assume they are physically based, due to the presence of excess entropy in the intracluster medium in addition to that generated by accretion shocks during the formation of the cluster. Several mechanisms have been suggested as a means of generating this entropy. Focussing on those mechanisms that preheat the gas before it becomes a constituent of the virialized cluster environment, we present a simple, intuitive, physically motivated, analytic model that successfully captures the important physics associated...

  7. Functional groups show distinct differences in nitrogen cycling during early stand development: implications for forest management.

    Energy Technology Data Exchange (ETDEWEB)

    Aubrey, Doug, P.; Coyle, David, R. Coleman, Mark, D.

    2011-08-26

    Nutrient acquisition of forest stands is controlled by soil resource availability and belowground production, but tree species are rarely compared in this regard. Here, we examine ecological and management implications of nitrogen (N) dynamics during early forest stand development in productive commercial tree species with narrow (Populus deltoides Bartr. and Platanus occidentalis L.) and broad (Liquidambar styraciflua L. and Pinus taeda L.) site requirements while grown with a range of nutrient and water resources. We constructed N budgets by measuring N concentration ([N]) and N content (N{sub C}) of above- and belowground perennial and ephemeral tissues, determined N uptake (N{sub UP}), and calculated N use efficiency (NUE). Forest stands regulated [N] within species-specific operating ranges without clear temporal or treatment patterns, thus demonstrating equilibrium between tissue [N] and biomass accumulation. Forest stand N{sub C} and N{sub UP} increased with stand development and paralleled treatment patterns of biomass accumulation, suggesting productivity is tightly linked to N{sub UP}. Inclusion of above- and belowground ephemeral tissue turnover in N{sub UP} calculations demonstrated that maximum N demand for narrow-sites adapted species exceeded 200 kg N ha{sup -1} year{sup -1} while demand for broad-site adapted species was below this level. NUE was species dependent but not consistently influenced by N availability, suggesting relationships between NUE and resource availability were species dependent. Based on early stand development, species with broad site adaptability are favored for woody cropping systems because they maintain high above- and belowground productivity with minimal fertilization requirements due to higher NUE than narrow site adapted species.

  8. Characterization and evolutionary implications of the triad Asp-Xxx-Glu in group II phosphopantetheinyl transferases.

    Science.gov (United States)

    Wang, Yue-Yue; Li, Yu-Dong; Liu, Jian-Bo; Ran, Xin-Xin; Guo, Yuan-Yang; Ren, Ni-Ni; Chen, Xin; Jiang, Hui; Li, Yong-Quan

    2014-01-01

    Phosphopantetheinyl transferases (PPTases), which play an essential role in both primary and secondary metabolism, are magnesium binding enzymes. In this study, we characterized the magnesium binding residues of all known group II PPTases by biochemical and evolutionary analysis. Our results suggested that group II PPTases could be classified into two subgroups, two-magnesium-binding-residue-PPTases containing the triad Asp-Xxx-Glu and three-magnesium-binding-residue-PPTases containing the triad Asp-Glu-Glu. Mutations of two three-magnesium-binding-residue-PPTases and one two-magnesium-binding-residue-PPTase indicate that the first and the third residues in the triads are essential to activities; the second residues in the triads are non-essential. Although variations of the second residues in the triad Asp-Xxx-Glu exist throughout the whole phylogenetic tree, the second residues are conserved in animals, plants, algae, and most prokaryotes, respectively. Evolutionary analysis suggests that: the animal group II PPTases may originate from one common ancestor; the plant two-magnesium-binding-residue-PPTases may originate from one common ancestor; the plant three-magnesium-binding-residue-PPTases may derive from horizontal gene transfer from prokaryotes.

  9. BibA: a novel immunogenic bacterial adhesin contributing to group B Streptococcus survival in human blood.

    Science.gov (United States)

    Santi, Isabella; Scarselli, Maria; Mariani, Massimo; Pezzicoli, Alfredo; Masignani, Vega; Taddei, Annarita; Grandi, Guido; Telford, John L; Soriani, Marco

    2007-02-01

    By the analysis of the recently sequenced genomes of Group B Streptococcus (GBS) we have identified a novel immunogenic adhesin with anti-phagocytic activity, named BibA. The bibA gene is present in 100% of the 24 GBS strains analysed. BibA-specific IgG were found in human sera from normal healthy donors. The putative protein product is a polypeptide of 630 amino acids containing a helix-rich N-terminal domain, a proline-rich region and a canonical LPXTG cell wall-anchoring domain. BibA is expressed on the surface of several GBS strains, but is also recovered in GBS culture supernatants. BibA specifically binds to human C4-binding protein, a regulator of the classic complement pathway. Deletion of the bibA gene severely reduced the capacity of GBS to survive in human blood and to resist opsonophagocytic killing by human neutrophils. In addition, BibA expression increased the virulence of GBS in a mouse infection model. The role of BibA in GBS adhesion was demonstrated by the impaired ability of a bibA knockout mutant strain to adhere to both human cervical and lung epithelial cells. Furthermore, we calculated that recombinant BibA bound to human epithelial cells of distinct origin with an affinity constant of approximately 10(-8) M for cervical epithelial cells. Hence BibA is a novel multifunctional protein involved in both resistance to phagocytic killing and adhesion to host cells. The identification of this potential new virulence factor represents an important step in the development of strategies to combat GBS-associated infections.

  10. Survey of childhood empyema in Asia: Implications for detecting the unmeasured burden of culture-negative bacterial disease

    Directory of Open Access Journals (Sweden)

    Shen Xuzhuang

    2008-07-01

    Full Text Available Abstract Background Parapneumonic empyema continues to be a disease of significant morbidity and mortality among children despite recent advances in medical management. To date, only a limited number of studies have assessed the burden of empyema in Asia. Methods We surveyed medical records of four representative large pediatric hospitals in China, Korea, Taiwan and Vietnam using ICD-10 diagnostic codes to identify children Results During the study period, we identified 1,379 children diagnosed with empyema or pleural effusion (China, n = 461; Korea, n = 134; Taiwan, n = 119; Vietnam, n = 665. Diagnoses of pleural effusion (n = 1,074 were 3.5 times more common than of empyema (n = 305, although the relative proportions of empyema and pleural effusion noted in hospital records varied widely between the four sites, most likely because of marked differences in coding practices. Although pleural effusions were reported more often than empyema, children with empyema were more likely to have a cultured pathogen. In addition, we found that median age and gender distribution of children with these conditions were similar across the four countries. Among 1,379 empyema and pleural effusion specimens, 401 (29% were culture positive. Staphylococcus aureus (n = 126 was the most common organism isolated, followed by Streptococcus pneumoniae (n = 83, Pseudomonas aeruginosa (n = 37 and Klebsiella (n = 35 and Acinetobacter species (n = 34. Conclusion The age and gender distribution of empyema and pleural effusion in children in these countries are similar to the US and Western Europe. S. pneumoniae was the second leading bacterial cause of empyema and pleural effusion among Asian children. The high proportion of culture-negative specimens among patients with pleural effusion or empyema suggests that culture may not be a sufficiently sensitive diagnostic method to determine etiology in the majority of cases. Future prospective studies in different countries would

  11. Vibrational and electronic optical activity of the chiral disulphide group: implications for disulphide bridge conformation.

    Science.gov (United States)

    Bednárová, Lucie; Bour, Petr; Malon, Petr

    2010-05-15

    Using dihydrogendisulphide (H(2)S(2)), dimethyl- ((CH(3))(2)S(2)), and diethyldisulphide ((CH(3)CH(2))(2)S(2))as model molecules, theoretical ECD, VCD, and ROA spectra of nonplanar disulphides were calculated by DFT methods. Most of the calculated electronic and vibrational chiroptical features suffer an equivocal relation between calculatedsigns of ECD, VCD, or ROA and the sense of disulphide nonplanarity as noted earlier for low-lying ECD bands. This is a consequence of local C(2) symmetry of a disulphide group causing most electronic and vibrational transitions to occur as pairs falling to alternative A, B symmetry species, which become degenerate and switch their succession (and consequently the observed chiroptical sign pattern) at the energetically most favorable perpendicular conformation. According to present calculations, the key to resolving this ambiguity may involve the S-S stretching vibrational mode at approximately 500 cm(-1). The relation of signs of the relevant VCD and ROA features to sense of disulphide chirality seems simpler and less ambiguous. The right-handed arrangement of the S-S group (0 < chi(S-S) < 180 degrees) results in mostly negative VCD signals. Although relation to ROA still suffers some ambiguity, it gets clearer along the series H(2)S(2)-(CH(3))(2)S(2)-(CH(3)CH(2))(2)S(2). ROA is also attractive for the analysis of disulphide-containing peptides and proteins, because applying it to aqueous solutions is not problematic.

  12. Temperature and Light Effects on Extracellular Superoxide Production by Algal and Bacterial Symbionts in Corals: Implications for Coral Bleaching

    Science.gov (United States)

    Brighi, C.; Diaz, J. M.; Apprill, A.; Hansel, C. M.

    2014-12-01

    Increased surface seawater temperature due to global warming is one of the main causes of coral bleaching, a phenomenon in which corals lose their photosynthetic algae. Light and temperature induced production of superoxide and other reactive oxygen species (ROS) by these symbiotic algae has been implicated in the breakdown of their symbiotic association with the coral host and subsequent coral bleaching. Nevertheless, a direct link between Symbiodinium ROS production and coral bleaching has not been demonstrated. In fact, given the abundance and diversity of microorganisms within the coral holobiont, the concentration and fluxes of ROS within corals may involve several microbial sources and sinks. Here, we explore the role of increased light and temperature on superoxide production by coral-derived cultures of Symbiodinium algae and Oceanospirillales bacteria of the genus Endozoicomonas, which are globally common and abundant associates of corals. Using a high sensitivity chemiluminescent technique, we find that heat stress (exposure to 34°C vs. 23°C for 2hr or 24hr) has no significant effect on extracellular superoxide production by Symbiodinium isolates within clades B and C, regardless of the level of light exposure. Exposure to high light, however, increased superoxide production by these organisms at both 34°C and 23°C. On the other hand, extracellular superoxide production by Endozoicomonas bacteria tested under the same conditions was stimulated by the combined effects of thermal and light stress. The results of this research suggest that the sources and physical triggers for biological superoxide production within corals are more complex than currently assumed. Thus, further investigations into the biological processes controlling ROS dynamics within corals are required to improve our understanding of the mechanisms underpinning coral bleaching and to aid in the development of mitigation strategies.

  13. [Primary health care reform and implications for the organizational culture of Health Center Groups in Portugal].

    Science.gov (United States)

    Leone, Claudia; Dussault, Gilles; Lapão, Luís Velez

    2014-01-01

    The health sector's increasing complexity poses major challenges for administrators. There is considerable consensus on workforce quality as a key determinant of success for any health reform. This study aimed to explore the changes introduced by an action-training intervention in the organizational culture of the 73 executive directors of Health Center Groups (ACES) in Portugal during the primary health care reform. The study covers two periods, before and after the one-year ACES training, during which the data were collected and analyzed. The Competing Values Framework allowed observing that after the ACES action-training intervention, the perceptions of the executive directors regarding their organizational culture were more aligned with the practices and values defended by the primary health care reform. The study highlights the need to continue monitoring results over different time periods to elaborate further conclusions.

  14. Changing dietary habits of ethnic groups in Europe and implications for health.

    Science.gov (United States)

    Gilbert, Penelope A; Khokhar, Santosh

    2008-04-01

    A systematic review of the literature suggests the dietary habits of some ethnic groups living in Europe are likely to become less healthy as individuals increase consumption of processed foods that are energy dense and contain high levels of fat, sugar, and salt. Such products often replace healthy dietary components of the native diet, such as fruits, vegetables, nuts, and grains. Mixed food habits are emerging mainly amongst younger people in the second and third generations, most likely due to acculturation and adoption of a Western lifestyle. Age and immigrant generation are the major factors accounting for changes in dietary habits, whilst income, level of education, dietary laws, religion, and food beliefs are also important factors. Obesity, cardiovascular disease, diabetes, and hypertension present major problems for the mainstream European population. However, the risk of chronic disease is reported to be higher in ethnic populations, particularly South Asians, African Caribbeans, and Mexicans.

  15. The implication and potential applications of high-mobility group box 1 protein in breast cancer.

    Science.gov (United States)

    Sohun, Moonindranath; Shen, Huiling

    2016-06-01

    High-mobility group box 1 protein (HMGB1) is a highly conserved, non-histone and ubiquitous chromosomal protein found enriched in active chromatin forming part of the high mobility group family of proteins and is encoded by the HMGB1 gene (13q12) in human beings. It has various intranuclear and extracellular functions. It plays an important role in the pathogenesis of many diseases including cancer. In 2012, there was approximately 1.67 million new breast cancer cases diagnosed which makes it the second most frequent cancer in the world after lung cancer (25% of all cancers) and the commonest cancer among women. Both pre-clinical and clinical studies have suggested that HMGB1 might be a useful target in the management of breast cancer. This review summarises the structure and functions of HMGB1 and its dual role in carcinogenesis both as a pro-tumorigenic and anti-tumorigenic factor. It also sums up evidence from in vitro and in vivo studies using breast cancer cell lines and samples which demonstrate its influence in radiotherapy, chemotherapy and hormonal therapy in breast cancer. It may have particular importance in HER2 positive and metastatic breast cancer. It might pave the way for new breast cancer treatments through development of novel drugs, use of microRNAs (miRNAs), targeting breast cancer stem cells (CSCs) and breast cancer immunotherapy. It may also play a role in determining breast cancer prognosis. Thus HMGB1 may open up novel avenues in breast cancer management.

  16. A Bioinformatics Analysis Reveals a Group of MocR Bacterial Transcriptional Regulators Linked to a Family of Genes Coding for Membrane Proteins

    Directory of Open Access Journals (Sweden)

    Teresa Milano

    2016-01-01

    Full Text Available The MocR bacterial transcriptional regulators are characterized by an N-terminal domain, 60 residues long on average, possessing the winged-helix-turn-helix (wHTH architecture responsible for DNA recognition and binding, linked to a large C-terminal domain (350 residues on average that is homologous to fold type-I pyridoxal 5′-phosphate (PLP dependent enzymes like aspartate aminotransferase (AAT. These regulators are involved in the expression of genes taking part in several metabolic pathways directly or indirectly connected to PLP chemistry, many of which are still uncharacterized. A bioinformatics analysis is here reported that studied the features of a distinct group of MocR regulators predicted to be functionally linked to a family of homologous genes coding for integral membrane proteins of unknown function. This group occurs mainly in the Actinobacteria and Gammaproteobacteria phyla. An analysis of the multiple sequence alignments of their wHTH and AAT domains suggested the presence of specificity-determining positions (SDPs. Mapping of SDPs onto a homology model of the AAT domain hinted at possible structural/functional roles in effector recognition. Likewise, SDPs in wHTH domain suggested the basis of specificity of Transcription Factor Binding Site recognition. The results reported represent a framework for rational design of experiments and for bioinformatics analysis of other MocR subgroups.

  17. A Bioinformatics Analysis Reveals a Group of MocR Bacterial Transcriptional Regulators Linked to a Family of Genes Coding for Membrane Proteins

    Science.gov (United States)

    Milano, Teresa

    2016-01-01

    The MocR bacterial transcriptional regulators are characterized by an N-terminal domain, 60 residues long on average, possessing the winged-helix-turn-helix (wHTH) architecture responsible for DNA recognition and binding, linked to a large C-terminal domain (350 residues on average) that is homologous to fold type-I pyridoxal 5′-phosphate (PLP) dependent enzymes like aspartate aminotransferase (AAT). These regulators are involved in the expression of genes taking part in several metabolic pathways directly or indirectly connected to PLP chemistry, many of which are still uncharacterized. A bioinformatics analysis is here reported that studied the features of a distinct group of MocR regulators predicted to be functionally linked to a family of homologous genes coding for integral membrane proteins of unknown function. This group occurs mainly in the Actinobacteria and Gammaproteobacteria phyla. An analysis of the multiple sequence alignments of their wHTH and AAT domains suggested the presence of specificity-determining positions (SDPs). Mapping of SDPs onto a homology model of the AAT domain hinted at possible structural/functional roles in effector recognition. Likewise, SDPs in wHTH domain suggested the basis of specificity of Transcription Factor Binding Site recognition. The results reported represent a framework for rational design of experiments and for bioinformatics analysis of other MocR subgroups. PMID:27446613

  18. Detrital mineral chronology of the Uinta Mountain Group: Implications for the Grenville flood in southwestern Laurentia

    Science.gov (United States)

    Mueller, P.A.; Foster, D.A.; Mogk, D.W.; Wooden, J.L.; Kamenov, George D.; Vogl, J.J.

    2007-01-01

    Numerous studies have shown that large quantities of Grenville-age detritus dominate Neo-proterozoic to Cambrian arenites in southwest Laurentia (southwestern United States). U-Pb ages and Hf isotopic compositions of zircons and 40Ar/39Ar ages of white mica from clastic sedimentary rocks of the Neoproterozoic Uinta Mountain Group also indicate significant Mesoproterozoic detritus mixed with a variably abundant Archean component. Zircons with ages representative of the Paleoproterozoic basement in the eastern Uinta Mountains or the younger Paleoproterozoic rocks of the adjacent Yavapai-Mazatzal terranes were not observed. A limited range of initial ??Hf (???90% between -3 and +3) for Mesoproterozoic zircons suggests derivation from a source region (or regions) characterized by mixing between juvenile and reworked older crust during Grenville orogenesis. The enriched Grenville-age basement proposed to underlie much of southeastern North America may be this source based on similarities of Hf isotopic data from Mesoproterozoic zircons in Mississippi River sand and available paleocurrent data. If so, then disruption of this supply in the Cambrian may be related to Iapetan rifting and, perhaps, the separation of the Precordillera terrane from Laurentia. ?? 2007 The Geological Society of America.

  19. Dark matter in Draco and the Local Group Implications for direct detection experiments

    CERN Document Server

    Moore, B; Stadel, J; Quinn, T; Lake, G; Ghigna, S; Governato, F; Moore, Ben; Calcaneo-Roldan, Carlos; Stadel, Joachim; Quinn, Tom; Lake, George; Ghigna, Sebastiano; Governato, Fabio

    2001-01-01

    We use a cosmological simulation of the Local Group to make quantitative and speculative predictions for direct detection experiments. Cold dark matter (CDM) halos form via a complex series of mergers, accretion events and violent relaxation which precludes the formation of significant caustic features predicted by axially symmetric collapse. The halo density profiles are combined with observational constraints on the galactic mass distribution to constrain the local density of cold dark matter to lie in the range 0.18 <~ rho_CDM(R_solar)/GeV cm^-3 <~ 0.30. In velocity space, coherent streams of dark matter from tidally disrupted halos fill the halo and provide a tracer of the merging hierarchy. The particle velocities within triaxial CDM halos cannot be approximated by a simple Maxwellian distribution and is radially biased at the solar position. The detailed phase space structure within the solar system will depend on the early merger history of the progenitor halos and the importance of major mergers...

  20. Implications of Antibiotic Resistance in the Management of Helicobacter pylori Infection: Canadian Helicobacter Study Group

    Directory of Open Access Journals (Sweden)

    RH Hunt

    2000-01-01

    Full Text Available Eradication of Helicobacter pylori from the gastric and duodenal mucosa is an important clinical goal in the treatment of infected patients with peptic ulcer disease and other H pylori-associated conditions. Although several oral drug combination regimens are associated with eradication rates of approximately 85% in controlled trials, the success rate in patients infected with a resistant strain of H pylori is closer to 75%. Resistance to metronidazole and clarithromycin, which are common components of combination treatment regimens, is of greatest concern. Reported rates of H pylori resistance to various antibiotics vary considerably. In Canada, the data documenting H pylori susceptibility are limited but suggest that resistance to these antibiotics varies geographically and within specific treatment groups. Although susceptibility testing is not a prerequisite for initial treatment of individual patients infected with H pylori, formal efforts to identify and monitor both the causes and prevalence of antibiotic resistance across Canada are a much needed step in the ongoing management of this important infection. Recommended treatment regimens may be useful, even for treating apparently resistant H pylori strains. However, it is important to understand the mechanisms of the development of resistant strains to manage patients with treatment failure better.

  1. Invasive Group A Streptococcal Infection and Vaccine Implications, Auckland, New Zealand

    Science.gov (United States)

    Safar, Atheer; Stewart, Joanna; Trenholme, Adrian; Drinkovic, Dragana; Peat, Briar; Taylor, Susan; Read, Kerry; Roberts, Sally; Voss, Lesley

    2011-01-01

    We aimed to assess the effect of invasive group A streptococcal (GAS) infection and the potential effects of a multivalent GAS vaccine in New Zealand. During January 2005–December 2006, we conducted prospective population-based laboratory surveillance of Auckland residents admitted to all public hospitals with isolation of GAS from normally sterile sites. Using emm typing, we identified 225 persons with confirmed invasive GAS infection (median 53 years of age; range 0–97 years). Overall incidence was 8.1 cases per 100,00 persons per year (20.4/100,000/year for Maori and Pacific Islanders; 24.4/100,000/year for persons >65 years of age; 33/100,000/year for infants <1 year of age). Nearly half (49%) of all cases occurred in Auckland’s lowest socioeconomic quintile. Twenty-two persons died, for an overall case-fatality rate of 10% (63% for toxic shock syndrome). Seventy-four percent of patients who died had an underlying condition. To the population in our study, the proposed 26-valent vaccine would provide limited benefit. PMID:21749758

  2. Crystal structure of tarocystatin-papain complex: implications for the inhibition property of group-2 phytocystatins.

    Science.gov (United States)

    Chu, Ming-Hung; Liu, Kai-Lun; Wu, Hsin-Yi; Yeh, Kai-Wun; Cheng, Yi-Sheng

    2011-08-01

    Tarocystatin (CeCPI) from taro (Colocasia esculenta cv. Kaohsiung no. 1), a group-2 phytocystatin, shares a conserved N-terminal cystatin domain (NtD) with other phytocystatins but contains a C-terminal cystatin-like extension (CtE). The structure of the tarocystatin-papain complex and the domain interaction between NtD and CtE in tarocystatin have not been determined. We resolved the crystal structure of the phytocystatin-papain complex at resolution 2.03 Å. Surprisingly, the structure of the NtD-papain complex in a stoichiometry of 1:1 could be built, with no CtE observed. Only two remnant residues of CtE could be built in the structure of the CtE-papain complex. Therefore, CtE is easily digested by papain. To further characterize the interaction between NtD and CtE, three segments of tarocystatin, including the full-length (FL), NtD and CtE, were used to analyze the domain-domain interaction and the inhibition ability. The results from glutaraldehyde cross-linking and yeast two-hybrid assay indicated the existence of an intrinsic flexibility in the region linking NtD and CtE for most tarocystatin molecules. In the inhibition activity assay, the glutathione-S-transferase (GST)-fused FL showed the highest inhibition ability without residual peptidase activity, and GST-NtD and FL showed almost the same inhibition ability, which was higher than with NtD alone. On the basis of the structures, the linker flexibility and inhibition activity of tarocystatins, we propose that the overhangs from the cystatin domain may enhance the inhibition ability of the cystatin domain against papain.

  3. Validating justifications in preschool girls' and boys' friendship group talk: implications for linguistic and socio-cognitive development.

    Science.gov (United States)

    Kyratzis, Amy; Ross, Tamara Shuqum; Koymen, S Bahar

    2010-01-01

    Children are believed to construct their causal theories through talk and interaction, but with the exception of a few studies, little or nothing is known about how young children justify and build theories of the world together with same-age peers through naturally occurring interaction, Children's sensitivity to when a pair or group of interlocutors who interact frequently together feel that a justification is needed, is an index of developing pragmatic competence (Goetz & Shatz, 1999) and may be influenced by interactive goals and gender identity positioning. Studies suggest that salient contexts for justifications for young children are disagreement and control (e.g. Veneziano & Sinclair, 1995) but researchers have been less recognizant of 'situations in which partners verbally assist in the construction of justifications as a means to maintain contact or create solidarity' (Goetz & Shatz, 1999: 722) as contexts for justifications. The present study examined the spontaneously produced justification constructions in the naturally occurring free play of five friendship groups of preschool-aged children (aged from 3 ; 6 to 5 ; 4), in terms of the motivating context of the justification, marking of the causal relationship with a connective, and causal theories accessed in the talk. Partner expansion (validating justifications) was a salient motivating context for justifications, especially in the talk of friendship groups of girls, and seemed to privilege greater marking of the causal relationship with a connective and less arbitrary reasoning. One group of girls varied their use of validating justifications depending on the theme of play. Results are discussed in terms of the implications of use of validating justifications for children's causal theory building with peers, linguistic development, and pragmatic development.

  4. Use of the delta neutrophil index as a prognostic factor of mortality in patients with spontaneous bacterial peritonitis: implications of a simple and useful marker.

    Directory of Open Access Journals (Sweden)

    Tae Seop Lim

    Full Text Available BACKGROUND: Spontaneous bacterial peritonitis (SBP is a common and life-threatening infection in patients with advanced cirrhosis. The prognostic value of a novel marker, the delta neutrophil index (DNI, was investigated relative to mortality in patients with SBP. MATERIALS & METHODS: Seventy-five patients with SBP were studied from April 2010 to May 2012. DNI at initial diagnosis of SBP was determined and compared with 30-day mortality rates. RESULTS: Of the patients, 87.7% were men, and the median age of all patients was 59.0 yrs. The area under the receiver-operating characteristic (ROC curve of DNI for 30-day mortality was 0.701 (95% confidence interval [CI], 0.553-0.849; p = 0.009, which was higher than that of C-reactive protein (0.640, 95% CI, 0.494-0.786; p = 0.076 or the model for end-stage liver disease score (0.592, 95% CI, 0.436-0.748; p = 0.235. From the ROC curve, with the sum of sensitivity and specificity, the cutoff value of DNI was determined to be 5.7%. In the high-DNI group (DNI ≥5.7%, septic shock and 30-day mortality were more prevalent compared with the low-DNI group (84.2% vs. 48.2%, p = 0.007; 57.9% vs. 14.3%, p<0.001, respectively. Patients with an elevated DNI had a higher risk of 30-day mortality compared with those with a low DNI (4.225, 95% CI, 1.631-10.949; p = 0.003. CONCLUSION: A higher DNI at the time of SBP diagnosis is an independent predictor of 30-day mortality in patients with SBP.

  5. Bacterial Vaginosis

    Science.gov (United States)

    ... Issues > Conditions > Sexually Transmitted > Bacterial Vaginosis Health Issues Listen Español Text Size Email Print Share Bacterial Vaginosis Page Content Bacterial vaginosis (BV) is the most common vaginal infection in sexually active teenaged girls . It appears to be caused by ...

  6. Significance of grooming behavior in two polygynous groups of western black crested gibbons: Implications for understanding social relationships among immigrant and resident group members.

    Science.gov (United States)

    Guan, Zhen-Hua; Huang, Bei; Ning, Wen-He; Ni, Qing-Yong; Sun, Guo-Zheng; Jiang, Xue-Long

    2013-12-01

    In primates, grooming is considered among the most common behaviors for maintaining social bonds; however, to date, few studies have examined grooming behavior in gibbon species in detail. We used both a 5-min interval scan method and social network analysis to study grooming in two groups of polygynous western black-crested gibbon (Nomascus concolor) in Wuliang Mountain, Central Yunnan, China. Individuals in both groups spent little time in social grooming (1.45% and 1.97% of active time). We compared the two groups' grooming networks and found that the group that maintained a more stable social unit had a more complex grooming network while the group with new immigrants had a grooming network characterized by fewer grooming pairs. Females in both groups played important roles in the grooming network. A newly immigrant female spent the most time grooming others and chose the resident adult female as her main adult grooming partner. Other females from both groups chose the adult male as their primary grooming partner (except their offspring). A sub-adult male who had resided in his natal group for 2 years after maturing into an adult also groomed more and was at the center of the network. This male finally replaced the breeding male in his group 3 years after our data collection period ended. We hypothesize that the immigrant female and the resident young adult male engaged in more extensive grooming interactions as a behavioral strategy to gain tolerance from long-term residents. Our results suggest that female gibbons in polygynous groups actively cooperate in maintaining social relationships rather than co-exist through tolerance or avoidance. Our observations indicate that grooming networks in crested gibbons reflect individual dynamics and partly support the social cohesion hypothesis for primate grooming. In this regard, we suggest that changes in gibbon grooming networks can be used to predict social change.

  7. A study on the ability of quaternary ammonium groups attached to a polyurethane foam wound dressing to inhibit bacterial attachment and biofilm formation.

    Science.gov (United States)

    Tran, Phat L; Hamood, Abdul N; de Souza, Anselm; Schultz, Gregory; Liesenfeld, Bernd; Mehta, Dilip; Reid, Ted W

    2015-01-01

    Bacterial infection of acute and chronic wounds impedes wound healing significantly. Part of this impediment is the ability of bacterial pathogens to grow in wound dressings. In this study, we examined the effectiveness of a polyurethane (PU) foam wound dressings coated with poly diallyl-dimethylammonium chloride (pDADMAC-PU) to inhibit the growth and biofilm development by three main wound pathogens, Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii, within the wound dressing. pDADMAC-PU inhibited the growth of all three pathogens. Time-kill curves were conducted both with and without serum to determine the killing kinetic of pDADMAC-PU. pDADMAC-PU killed S. aureus, A. baumannii, and P. aeruginosa. The effect of pDADMAC-PU on biofilm development was analyzed quantitatively and qualitatively. Quantitative analysis, colony-forming unit assay, revealed that pDADMAC-PU dressing produced more than eight log reduction in biofilm formation by each pathogen. Visualization of the biofilms by either confocal laser scanning microscopy or scanning electron microscopy confirmed these findings. In addition, it was found that the pDADMAC-PU-treated foam totally inhibited migration of bacteria through the foam for all three bacterial strains. These results suggest that pDADMAC-PU is an effective wound dressing that inhibits the growth of wound pathogens both within the wound and in the wound dressing.

  8. CHANDRA observations of the NGC 1550 galaxy group: Implication for the temperature and entropy profiles of 1 keV galaxy groups

    DEFF Research Database (Denmark)

    Sun, M.; Forman, W.; Vikhlinin, A.

    2003-01-01

    We present a detailed Chandra study of the galaxy group NGC 1550. For its temperature (1.37 +/- 0.01 keV) and velocity dispersion (similar to300 km s(-1)), the NGC 1550 group is one of the most luminous known galaxy groups (L-bol = 1.65 x 10(43) ergs s(-1) within 200 kpc, or 0.2r(vir)). We find...... that within similar to 60 kpc, where the gas cooling time is less than a Hubble time, the gas temperature decreases continuously toward the center, implying the existence of a cooling core. The temperature also declines beyond similar to 100 kpc (or 0.1r(vir)). The temperature pro. le of NGC 1550...

  9. Characterization of the Bacterial Community Naturally Present on Commercially Grown Basil Leaves: Evaluation of Sample Preparation Prior to Culture-Independent Techniques

    Directory of Open Access Journals (Sweden)

    Siele Ceuppens

    2015-08-01

    Full Text Available Fresh herbs such as basil constitute an important food commodity worldwide. Basil provides considerable culinary and health benefits, but has also been implicated in foodborne illnesses. The naturally occurring bacterial community on basil leaves is currently unknown, so the epiphytic bacterial community was investigated using the culture-independent techniques denaturing gradient gel electrophoresis (DGGE and next-generation sequencing (NGS. Sample preparation had a major influence on the results from DGGE and NGS: Novosphingobium was the dominant genus for three different basil batches obtained by maceration of basil leaves, while washing of the leaves yielded lower numbers but more variable dominant bacterial genera including Klebsiella, Pantoea, Flavobacterium, Sphingobacterium and Pseudomonas. During storage of basil, bacterial growth and shifts in the bacterial community were observed with DGGE and NGS. Spoilage was not associated with specific bacterial groups and presumably caused by physiological tissue deterioration and visual defects, rather than by bacterial growth.

  10. The Mesoproterozoic volcano-sedimentary Serra do Itaberaba Group of the Central Ribeira Belt, Sao Paulo State, Brazil: implications for the age of the overlying Sao Roque Group

    Energy Technology Data Exchange (ETDEWEB)

    Juliani, Caetano [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias]. E-mail: cjuliani@usp.br; Hackspacher, Peter; Fetter, Allen Hutchenson [UNESP, Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas]. E-mail: phack@rc.unesp.br; fetter@rc.unesp.br; Dantas, Elton Luiz [Brasilia Univ., DF (Brazil). Inst. de Geociencias]. E-mail: elton@unb.br

    2000-03-01

    One of the fundamental problems to understanding the evolution of volcano-sedimentary sequences in southeastern Brazil is constraining their depositional ages. Brasiliano tectonic and metamorphic either obscured or destroyed primary features, such as unconformities, as well as other geologic relationships. This problem is exemplified by the Serra do Itaberaba and Sao Roque groups, where the lack of data about the timing of their deposition has prevented resolution of proposed one-and two-stage geotectonic/depositional models. Recent U-Pb zircon data obtained from metavolcanic rocks in the Sao Roque Group indicate that it was deposited between 628 and 607 Ma. New U-Pb zircon data of 1395{+-} 10 Ma for a metandesite in the basal Morro da Pedra Preta Formation (Serra do Itaberaba Group) indicate the maximum age for the beginning of the deposition of the pelites overlying MORB-like basalt. A metarhyolite of the upper unit, the Nhangucu Formation, contains two zircon populations. One yielded an age of 619 {+-}3 Ma, which defines the crystallization age of the rock, and the other an age of 1449 {+-}3 Ma, interpreted as inherited xenocrystal grains from older units of the Serra do Itaberaba Group. The younger metarhyolite was affected only by the S{sub 2} foliation, generated during the Brasiliano orogenesis, whereas the Middle Proterozoic metavolcano-sedimentary sequence records additional metamorphic and deformational events, confirming the presence of two different geotectonic cycles. (author)

  11. Bacterial DNA induces the complement system activation in serum and ascitic fluid from patients with advanced cirrhosis.

    Science.gov (United States)

    Francés, Rubén; González-Navajas, José M; Zapater, Pedro; Muñoz, Carlos; Caño, Rocío; Pascual, Sonia; Márquez, Dorkas; Santana, Francia; Pérez-Mateo, Miguel; Such, José

    2007-07-01

    Translocation of intestinal bacteria to ascitic fluid is, probably, the first step in the development of spontaneous bacterial peritonitis in patients with cirrhosis. Proteins of the complement system are soluble mediators implicated in the host immune response to bacterial infections and its activation has been traditionally considered to be an endotoxin-induced phenomenon. The aim of this study was to compare the modulation of these proteins in response to the presence of bacterial DNA and/or endotoxin in patients with advanced cirrhosis and ascites in different clinical conditions. Groups I and II consisted of patients without/with bacterial DNA. Group III included patients with spontaneous bacterial peritonitis and Group IV with patients receiving norfloxacin as secondary long-term prophylaxis of spontaneous bacterial peritonitis. Serum and ascitic fluid levels of endotoxin and truncated residues of the complement system were measured by ELISA. The complement system is triggered in response to bacterial DNA, as evidenced by significantly increased levels of C3b, membrane attack complex, and C5a in patients from Groups II and III compared with patients without bacterial DNA (Group I) and those receiving norfloxacin (Group IV). Gram classification did not further differentiate the immune response between patients within groups II and III, even though endotoxin levels were, as expected, significantly higher in patients with bacterial DNA from gram-negative microorganisms. The complement protein activation observed in patients with bacterial DNA in blood and ascitic fluid is indistinguishable from that observed in patients with spontaneous bacterial peritonitis and may occur in an endotoxin-independent manner.

  12. The treatment of bacterial vaginosis in pregnancy with clindamycin to reduce the risk of infection-related preterm birth: a response to the Danish Society of Obstetrics and Gynecology guideline group's clinical recommendations.

    Science.gov (United States)

    Lamont, Ronald F; Keelan, Jeffrey A; Larsson, Per G; Jørgensen, Jan S

    2017-02-01

    Preterm birth is the major cause of perinatal mortality and morbidity worldwide. Infection/inflammation is responsible for a significant percentage of preterm birth, particularly at early gestations. A recent clinical recommendation by a guidelines group of the Danish Society of Obstetrics and Gynecology advised against the use of clindamycin for the treatment of bacterial vaginosis in pregnancy to reduce the risk of spontaneous preterm birth based on lack of evidence of efficacy. We believe that the evidence for the use of clindamycin for this indication is robust and that this recommendation was reached erroneously on the basis of flawed inclusion criteria: the inclusion of an unpublished study with poorly diagnosed bacterial vaginosis and the exclusion of an important pivotal study on the use of clindamycin in early pregnancy for the prevention of preterm birth. Had these errors been corrected, the conclusions would have been different.

  13. Care for chronic illness in Australian general practice – focus groups of chronic disease self-help groups over 10 years: implications for chronic care systems reforms

    Directory of Open Access Journals (Sweden)

    Martin Carmel M

    2009-01-01

    Full Text Available Abstract Background Chronic disease is a major global challenge. However, chronic illness and its care, when intruding into everyday life, has received less attention in Asia Pacific countries, including Australia, who are in the process of transitioning to chronic disease orientated health systems. Aim The study aims to examine experiences of chronic illness before and after the introduction of Australian Medicare incentives for longer consultations and structured health assessments in general practice. Methods Self-help groups around the conditions of diabetes, epilepsy, asthma and cancer identified key informants to participate in 4 disease specific focus groups. Audio taped transcripts of the focus groups were coded using grounded theory methodology. Key themes and lesser themes identified using a process of saturation until the study questions on needs and experiences of care were addressed. Thematic comparisons were made across the 2002/3 and 1992/3 focus groups. Findings At times of chronic illness, there was need to find and then ensure access to 'the right GP'. The 'right GP or specialist' committed to an in-depth relationship of trust, personal rapport and understanding together with clinical and therapeutic competence. The 'right GP', the main specialist, the community nurse and the pharmacist were key providers, whose success depended on interprofessional communication. The need to trust and rely on care providers was balanced by the need for self-efficacy 'to be in control of disease and treatment' and 'to be your own case manager'. Changes in Medicare appeared to have little penetration into everyday perceptions of chronic illness burden or time and quality of GP care. Inequity of health system support for different disease groupings emerged. Diabetes, asthma and certain cancers, like breast cancer, had greater support, despite common experiences of disease burden, and a need for research and support programs. Conclusion Core

  14. Repetitive genome elements in a European corn borer, Ostrinia nubilalis, bacterial artificial chromosome library were indicated by bacterial artificial chromosome end sequencing and development of sequence tag site markers: implications for lepidopteran genomic research.

    Science.gov (United States)

    Coates, Brad S; Sumerford, Douglas V; Hellmich, Richard L; Lewis, Leslie C

    2009-01-01

    The European corn borer, Ostrinia nubilalis, is a serious pest of food, fiber, and biofuel crops in Europe, North America, and Asia and a model system for insect olfaction and speciation. A bacterial artificial chromosome library constructed for O. nubilalis contains 36 864 clones with an estimated average insert size of >or=120 kb and genome coverage of 8.8-fold. Screening OnB1 clones comprising approximately 2.76 genome equivalents determined the physical position of 24 sequence tag site markers, including markers linked to ecologically important and Bacillus thuringiensis toxin resistance traits. OnB1 bacterial artificial chromosome end sequence reads (GenBank dbGSS accessions ET217010 to ET217273) showed homology to annotated genes or expressed sequence tags and identified repetitive genome elements, O. nubilalis miniature subterminal inverted repeat transposable elements (OnMITE01 and OnMITE02), and ezi-like long interspersed nuclear elements. Mobility of OnMITE01 was demonstrated by the presence or absence in O. nubilalis of introns at two different loci. A (GTCT)n tetranucleotide repeat at the 5' ends of OnMITE01 and OnMITE02 are evidence for transposon-mediated movement of lepidopteran microsatellite loci. The number of repetitive elements in lepidopteran genomes will affect genome assembly and marker development. Single-locus sequence tag site markers described here have downstream application for integration within linkage maps and comparative genomic studies.

  15. The bacterial lipocalins.

    Science.gov (United States)

    Bishop, R E

    2000-10-18

    The lipocalins were once regarded as a eukaryotic protein family, but new members have been recently discovered in bacteria. The first bacterial lipocalin (Blc) was identified in Escherichia coli as an outer membrane lipoprotein expressed under conditions of environmental stress. Blc is distinguished from most lipocalins by the absence of intramolecular disulfide bonds, but the presence of a membrane anchor is shared with two of its closest homologues, apolipoprotein D and lazarillo. Several common features of the membrane-anchored lipocalins suggest that each may play an important role in membrane biogenesis and repair. Additionally, Blc proteins are implicated in the dissemination of antibiotic resistance genes and in the activation of immunity. Recent genome sequencing efforts reveal the existence of at least 20 bacterial lipocalins. The lipocalins appear to have originated in Gram-negative bacteria and were probably transferred horizontally to eukaryotes from the endosymbiotic alpha-proteobacterial ancestor of the mitochondrion. The genome sequences also reveal that some bacterial lipocalins exhibit disulfide bonds and alternative modes of subcellular localization, which include targeting to the periplasmic space, the cytoplasmic membrane, and the cytosol. The relationships between bacterial lipocalin structure and function further illuminate the common biochemistry of bacterial and eukaryotic cells.

  16. The fault pattern in the northern Negev and southern Coastal Plain of Israel and its hydrogeological implications for groundwater flow in the Judea Group aquifer

    Science.gov (United States)

    Weinberger, G.; Rosenthal, E.

    1994-03-01

    On the basis of a broadly expanding data base, the hydrogeological properties of the Judea Group sequence in the northern Negev and southern Coastal Plain of Israel have been reassessed. The updated subsurface model is based on data derived from water- and oil-wells and on recent large-scale geophysical investigations. A new regional pattern of the reassessed geological through the subsurface of the study area has been revealed. In view of the reassessed geological and hydrological subsurface setting, it appears that the Judea Group aquifer should not be regarded as one continuous and undisturbed hydrological unit; owing to the occurrence of regional faults, its subaquifers are locally interconnected. These subaquifers, which contain mainly high-quality water, are juxtaposed, as a result of faulting, against Kurnub Group sandstones containing brackish paleowater. The latter Group is faulted against late Jurassic formations containing highly saline groundwater. In the Beer Sheva area, the Judea Group aquifer is vertically displaced against the Senonian and Eocene Mt. Scopus and Avdat Groups, which also contain brackish and saline water. In the southern Coastal Plain, major faults locally dissect also the Pleistocene Kurkar Group, facilitating inflow of Mg-rich groundwater deriving from Judea Group dolomites. The new geological evidence and its hydrogeological implications provide new solutions for previously unexplained salinization phenomena.

  17. 神宁煤业集团实施品牌营销战略的思考%Thinking of Implicating Brand Marketing in Shenhua Ningxia Coal Group

    Institute of Scientific and Technical Information of China (English)

    梁瑞民

    2013-01-01

    从3个方面阐述了煤炭企业实施品牌营销战略的必要性,分析了当前形势下神宁煤业集团实施品牌营销战略的优势和紧迫性,围绕树立品牌意识、宣传意识、质量意识、服务意识、创新意识,提出了实施品牌营销战略的具体举措。%This paper puts forward specific measures of implicating brand marketing strategies centering on building consciousness of brand, advertise, quality, service and innovation after analyzing urgencies and superiorities of brand marketing strategies of current positions in Shenhua Ningxia Coal Group and discussing necessities of implication in coal enterprises from three aspects.

  18. An Examination of Which Implications New Media Platforms Can Have on Study Group Work and Learning Opportunities in the Environment of the Course Information Systems for Business

    DEFF Research Database (Denmark)

    Hougaard, Simone Quach; Trankjær, Mie Bohn; Schlichter, Bjarne Rerup

    2014-01-01

    implications New Media platforms – with special emphasis on Blackboard, Facebook, Google Docs and Dropbox – have on study group work in the environment of the course Information Systems for Business (ISB) at Aarhus University. Additionally, it is investigated which opportunities these platforms potentially...... to facilitate study group work in the course. Most students were positive towards the use of these platforms and found that their group work had become more effective as a direct result. However, some limitations were also found in using New Media platforms in all aspects of the ISB course, as some of the more...... could have on the learning environment at the university, as this could be of significant importance in the future educational system. The research is based on literature about New Media and New Media’s role in collaboration and learning environments. In order to establish some empirical grounding...

  19. Solvation free energy of the peptide group: its model dependence and implications for the additive-transfer free-energy model of protein stability.

    Science.gov (United States)

    Tomar, Dheeraj S; Asthagiri, D; Weber, Valéry

    2013-09-17

    The group-additive decomposition of the unfolding free energy of a protein in an osmolyte solution relative to that in water poses a fundamental paradox: whereas the decomposition describes the experimental results rather well, theory suggests that a group-additive decomposition of free energies is, in general, not valid. In a step toward resolving this paradox, here we study the peptide-group transfer free energy. We calculate the vacuum-to-solvent (solvation) free energies of (Gly)n and cyclic diglycine (cGG) and analyze the data according to experimental protocol. The solvation free energies of (Gly)n are linear in n, suggesting group additivity. However, the slope interpreted as the free energy of a peptide unit differs from that for cGG scaled by a factor of half, emphasizing the context dependence of solvation. However, the water-to-osmolyte transfer free energies of the peptide unit are relatively independent of the peptide model, as observed experimentally. To understand these observations, a way to assess the contribution to the solvation free energy of solvent-mediated correlation between distinct groups is developed. We show that linearity of solvation free energy with n is a consequence of uniformity of the correlation contributions, with apparent group-additive behavior in the water-to-osmolyte transfer arising due to their cancellation. Implications for inferring molecular mechanisms of solvent effects on protein stability on the basis of the group-additive transfer model are suggested.

  20. Bacterial gastroenteritis

    Science.gov (United States)

    Bacterial gastroenteritis is present when bacteria cause an infection of the stomach and intestines ... has not been treated Many different types of bacteria can cause ... Campylobacter jejuni E coli Salmonella Shigella Staphylococcus ...

  1. The Implications of Serum Procalcitonion(PCT) and Blood Normal(BR) Detection in Patients with Bacterial Pneumonia%血清降钙素原和血常规测定对细菌性肺炎的指导意义

    Institute of Scientific and Technical Information of China (English)

    颜鲲; 徐慧兰

    2014-01-01

    Objective To evaluate the implications of the detection of Serum Procalcitonion (PCT) and BR in patients with Bacterial Pneumonia,and provide theoretical reference for diagnosis and treatment of Bacterial Pneumonia. Methods 64 samples were col ected from patients with Bacterial Pneumonia in respiratory department、ICU and emergency department from January to November 2011,and compared with 32 healthy people .PCT and BR were measured. The PCT level was determined by Brahms PCT-Q method. Results The sensitivities of PCT and BR were 78 %and 63 %,respectively with the sepcificities being 97 %and 70 %.The serum PCT levels of Bacterial Pneumonia group were higher than the healthy group, compared the difference was significant (P<0.05). The serum PCT levels of Bacterial Pneumonia group before using antibiotics were higher than that after effective therapy, compared the difference was significant (P<0.05). Conclusions The serum PCT has diagnostic value for the Bacterial Pneumonia, and it is a useful index to assess the clinical efficacy in patients using antibiotics. It is worthy of clinical application.%目的:探讨血清降钙素原(PCT)和血常规(BR)在细菌性肺炎诊断中的应用价值,旨在为细菌性肺炎的诊治提供理论参考。方法选取中南大学湘雅三医院2011年1月至11月在呼吸、急诊、ICU 住院的细菌性肺炎患者64例,同期健康对照组32例,血清 PCT 采用 Brahms 快速半定量法(PCT-Q)测定,同期检测血常规。结果细菌性肺炎组中,PCT、白细胞计数对诊断的敏感性分别为78%和63%,特异性分别为97%和70%,细菌性肺炎组较健康对照组 PCT 水平显著增高,相比较有显著性差异(P <0.05)。细菌性肺炎组抗生素治疗前和好转后,血清 PCT 水平显著下降,相比较有显著性差异(P <0.05)。结论血清 PCT 的测定对细菌性肺炎有鉴别诊断价值,特别是可反应抗生素治疗效果,值得临床推广应用。

  2. Identification of rhesus macaque genital microbiota by 16S pyrosequencing shows similarities to human bacterial vaginosis: implications for use as an animal model for HIV vaginal infection.

    Science.gov (United States)

    Spear, Gregory T; Gilbert, Douglas; Sikaroodi, Masoumeh; Doyle, Lara; Green, Linda; Gillevet, Patrick M; Landay, Alan L; Veazey, Ronald S

    2010-02-01

    The composition of the lower genital tract microbiota in women is believed to affect the risk of sexually acquiring HIV. Since macaque genital microbiota could similarly impact vaginal infection with SIV we identified microbiota in 11 rhesus macaques using multitag pyrosequencing of the 16S rRNA gene. The microbiota was polymicrobial with a median of nine distinct bacterial taxa per macaque (range 3-16 taxa, each constituting 1% or more of the sequences). Taxa frequently found included Peptoniphilus, Sneathia, Porphyromonas, Mobiluncus, Atopobacter, Dialister, Thioreductor, Prevotella, and Streptococcus, many of which are also frequently found in women with bacterial vaginosis. Lactobacillus sequences (mostly L. johnsonii) were found in only four macaques but were not predominant in any (median of 0% of sequences, range 0-39%). All macaques were resampled 6 months after the first time point to determine the stability of the microbiota. The microbiota remained polymicrobial with a median of 10 taxa (range 6-18). Microbial patterns remained similar for six of the macaques, changed substantially in two, and had a mixed pattern in three. Significant sialidase enzyme activity, a marker of bacteria vaginosis in women, was detected in genital fluid from 9/11 and 8/11 macaques from the first and second time points, respectively. These results show that the macaque lower genital microbiota resembled a bacteria vaginosis-type microbiota in women and suggest that the microbiota of macaques in captivity promote rather than protect against vaginal infection with SIV. These results also suggest macaques could be used as an animal model to study some aspects of bacterial vaginosis.

  3. Clinical Implications for Muscle Strength Differences in Women of Different Age and Racial Groups: The WIN Study

    Science.gov (United States)

    Trudelle-Jackson, Elaine; Ferro, Emerenciana; Morrow, James R.

    2011-01-01

    Background Reduction in muscle strength is strongly associated with functional decline in women, and women with lower quadriceps strength adjusted for body weight are more likely to develop knee osteoarthritis. Objective To compare body weight--adjusted strength among women of different age/racial groups. Study Design Cross-sectional study of muscle strength in 918 women aged 20--83 (M ± SD = 52 ± 13). Methods An orthopedic examination was conducted including measurement of handgrip and lower extremity strength (hip abductors/external rotators, knee flexors/extensors). Data were grouped into young (20--39 years, n = 139), middle (40--54 years, n = 300), and older (55+ years, n = 424) ages for white (n = 699) and African American (AA) (n = 164) women. Means and standard deviations for strength adjusted for body weight were calculated for each age and racial group and compared using 2-way multivariate analysis of variance and post hoc tests. Results No significant age-by-race interaction (P = .092) but significant main effects for age and race (P < .001). Pairwise comparisons revealed significant differences in knee extensor and flexor strength between all age groups. For grip and hip external rotator strength, significant differences were found between the middle and older groups. Differences in hip abductor strength were found between the young and middle-aged groups. AA women had lower strength than white women in all muscle groups (P < .05) except hip external rotators. Conclusions Strength decreased with age in all muscle groups but magnitude of decrease varied by muscle. Strengthening programs should target different muscles, depending on a woman's age and race. PMID:21666779

  4. CT Examination of Nose and Paranasal Sinuses of Egyptian Mummies and Three Distinct Human Population Groups: Anthropological and Clinical Implications.

    Science.gov (United States)

    Márquez, Samuel; Lawson, William; Mowbray, Kenneth; Delman, Bradley N; Laitman, Jeffrey T

    2015-06-01

    The interaction of nasal morphology and climatic conditions has resulted in diverse hard- and soft-tissue configurations across human population groups. While the processes of skull pneumatization are not fully understood, the invasions of the paranasal sinuses [PNS] into the cranium have contributed to assorted morphologies. Human migratory patterns and the strong association with climatic variables through time and space may explain this diversity. This study examined four multiregional populations of which two are from Egypt but of widely divergent eras. Three Egyptian mummies [EG-M] from the middle kingdom were CT scanned providing a unique opportunity to investigate the status of PNS anatomy within a time frame from 1567 BCE to 600 CE and compare it to a contemporary Egyptian [EG] (n = 12) population. Dry skulls of Inuit [IT] (n = 10) and East African [EA] (n = 8) provide out-group comparisons, as one group represents an isolated geographic environment far different from that of Egypt and the other group inhabiting distinct environmental conditions albeit located within the same continent. Results showed EG-M and EG frontal sinus volumes were diminutive in size with no statistically significant difference between them. Maxillary sinus size values of EG-M and EG clustered together while IT and EA significantly differed from each other (P = 0.002). The multiregional groups exhibited population specific morphologies in their PNS anatomy. Ecogeographic localities revealed anatomical differences among IT and EA, while the potential time span of about 3,500 years produced only a negligible difference between the Egyptian groups. The small sample sizes incorporated into this research requires confirmation of the results by analyses of larger samples from each geographic region and with the integration of a larger group of Egyptian mummified remains.

  5. Immunophenotyping at the Time of Diagnosis Distinguishes Two Groups of Nasopharyngeal Carcinoma Patients: Implications for Adoptive Immunotherapy

    Directory of Open Access Journals (Sweden)

    Jiang Li, Qiu-yan Chen, Haoyuan Mo, Yi-lan Zhang, Zhou-feng Huang, Yi-xin Zeng

    2011-01-01

    Full Text Available Background: Adoptive immunotherapy with EBV-specific CTLs (EBV-CTL has been used to treat EBV-associated nasopharyngeal carcinoma (NPC but only a fraction of the patients shows noticeable clinical response.Patients and Methods: Sixty-seven newly diagnosed NPC patients from 2005 to 2007 and 21 healthy donors were collected. Immunological parameters and immune function of PBMCs and EBV-CTL were analyzed by flow cytometer analysis (FACS and 51Cr releasing experiment; Molecular characteristics on NPC tumor cells were investigated by immunochemical staining and statistic analysis.Results: NPC patients can be classified into two groups based on the percentage of CD3+ T cells in peripheral blood before accepted any treatment, (>52.6%, mean-2SE from healthy controls, NPC Group 1; <52.6%, NPC Group 2. The patients in Group 2 showed a significant decrease of CD3+CD8+ T-cells, CD3+CD4+ T-cells and CD3+CD45RO+ memory T cells, and increase of CD3-CD16+ NK cells compared to Group 1 patients and healthy controls (P<0.001. EBV-specific T cell responses, were weaker in this group of patients and their tumor cells expressed lower levels of the EBV encoded latent membrane protein (LMP-1 and HLA class II protein compared with the patients of NPC Group 1 (P<0.05 .Conclusion: These findings demonstrate that NPC patients could be distinguished on the basis of their immune status which will affect the efficacy of EBV-CTL immunotherapy.

  6. Seizures Complicating Bacterial Meningitis

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-09-01

    Full Text Available The clinical data of 116 patients, 1 month to <5 years of age, admitted for bacterial meningitis, and grouped according to those with and without seizures during hospitalization, were compared in a study at Buddhist Dalin Tzu Chi General Hospital, Chang Gung Memorial Hospital and other centers in Taiwan.

  7. Identification of second arginine-glycine-aspartic acid motif of ovine vitronectin as the complement C9 binding site and its implication in bacterial infection.

    Science.gov (United States)

    T, Prasada Rao; T, Lakshmi Prasanth; R, Parvathy; S, Murugavel; Devi, Karuna; Joshi, Paritosh

    2017-02-02

    Vitronectin (Vn), a multifunctional protein of blood and extracellular matrix interacts with complement C9. This interaction may modulate innate immunity. Details of Vn-C9 interaction are limited. An assessment of Vn-C9 interaction was made employing goat homologous system. Vn binding to C9 was observed in three different assays. Using recombinant fragments, the C9 binding was mapped to the N-terminus of Vn. Site directed mutagenesis was performed to alter the second RGD sequence (RGD-2) of Vn. Change of R to G or D to A in RGD-2 caused significant decrease in Vn binding to C9 whereas change of R to G in the first RGD motif (RGD-1) had no effect on Vn binding to C9. These results imply that the RGD-2 of goat Vn is involved in C9 binding. In competitive binding assay, the presence of soluble RGD peptide inhibited Vn binding to C9 whereas heparin had no effect. Vn binding to C9 in terms of bacterial pathogenesis was also evaluated. Serum dependent inhibition of E. coli growth was significantly reverted when Vn or its N-fragment were included in the assay. The C-fragment, which did not support C9 binding, also partly nullified serum dependent inhibition of bacterial growth probably through other serum component(s).

  8. The use of focus groups to examine pubertal concerns in preteen girls: initial findings and implications for practice and research.

    Science.gov (United States)

    Doswell, W M; Vandestienne, G

    1996-01-01

    This article presents the findings of four focus groups aimed at discovering the concerns a group of 9- to 12-year-old African American and Hispanic girls (N = 38) had about puberty, the transition to adolescence, and growing up. Among the factors these girls liked about growing up were increasing independence from parents, widening social relations with same- and opposite-sex friends, and an increase in decision making regarding clothes and activities. What they reported as not liking about growing up were an increase in peer pressure, high parental expectations, and more responsibility for their actions in home, school, and recreational activities. Health care for this group must include systematic monitoring of pubertal development and concerns in order to aggressively educate preadolescents to negotiate this period smoothly and to avoid high-risk behaviors that could have negative health and social sequelae during adolescence and adulthood.

  9. Implications of Social Practice Theory for the Development of a Numeracy Programme for the Gusilay People Group in Senegal

    Science.gov (United States)

    Gerger, Elisabeth

    2014-01-01

    In this article, I present research on some traditional numeracy practices of the Gusilay people group in Senegal and make recommendations for developing a numeracy programme for women. Based on a strong foundation of traditional knowledge and practices, the programme will aim to meet felt needs of women who are faced with new numeracy related…

  10. The Role of Community, Family, Peer, and School Factors in Group Bullying: Implications for School-Based Intervention

    Science.gov (United States)

    Mann, Michael J.; Kristjansson, Alfgeir L.; Sigfusdottir, Inga Dora; Smith, Megan L.

    2015-01-01

    Background: Although an ecological perspective suggests the importance of multiple levels of intervention, most bullying research has emphasized individual- and school-focused strategies. This study investigated community and family factors that influence school efforts to reduce odds of group bullying behavior and victimization. Methods: We used…

  11. Implications of Changing Ethnic-Group Representation in Indiana's Population. Part 1: Highlights and Summary. Manpower Report 86-2.

    Science.gov (United States)

    Lisack, J. P.; Shell, Kevin D.

    From 1970 to 1980, Indiana's population grew 5.7 percent, with the white population growing less than 4 percent as opposed to a 30 percent growth rate for minority groups. Nearly 64.4 of the state's minority population resided in Marion and Lake counties as of 1980. Except for Asian Americans, Indiana residents who belong to ethnic minority groups…

  12. The implications of different developmental patterns of disruptive behavior problems for school adjustment. Conduct Problems Prevention Research Group.

    Science.gov (United States)

    Stormshak, E A; Bierman, K L

    1998-01-01

    Based upon developmental models of disruptive behavior problems, this study examined the hypothesis that the nature of a child's externalizing problems at home may be important in predicting the probability of and nature of school adjustment problems at school entry. Parent ratings were collected for a sample of 631 behaviorally disruptive children using the Child Behavior Checklist. Confirmatory factor analyses revealed differentiated ratings of oppositional, aggressive, and hyperactive/inattentive behaviors at home. Teacher and peer nominations assessed school adjustment at the end of first grade. As expected from a developmental perspective, aggressive behaviors indicated more severe dysfunction and were more likely to generalize to the school setting than were oppositional behaviors. Hyperactive/inattentive behaviors at home led to more classroom disruption than did aggressive or oppositional behaviors. Co-occurring patterns of oppositional/aggressive and hyperactive/inattentive behaviors were more common than were single-problem patterns, and were associated with broad dysfunction in the social and classroom contexts. The results were interpreted within a developmental framework, in which oppositional, aggressive, and hyperactive/inattentive behaviors may reflect distinct (as well as shared) developmental processes that have implications for the home-to-school generalization of behavior problems and subsequent school adjustment.

  13. Multiple group I introns in the small-subunit rDNA of Botryosphaeria dothidea: implication for intraspecific genetic diversity.

    Directory of Open Access Journals (Sweden)

    Chao Xu

    Full Text Available Botryosphaeria dothidea is a widespread and economically important pathogen on various fruit trees, and it often causes die-back and canker on limbs and fruit rot. In characterizing intraspecies genetic variation within this fungus, group I introns, rich in rDNA of fungi, may provide a productive region for exploration. In this research, we analysed complete small subunit (SSU ribosomal DNA (rDNA sequences of 37 B. dothidea strains, and found four insertions, designated Bdo.S943, Bdo.S1199-A, Bdo.S1199-B and Bdo.S1506, at three positions. Sequence analysis and structure prediction revealed that both Bdo.S943 and Bdo.S1506 belonged to subgroup IC1 of group I introns, whereas Bdo.S1199-A and Bdo.S1199-B corresponded to group IE introns. Moreover, Bdo.S1199-A was found to host an open reading frame (ORF for encoding the homing endonuclease (HE, whereas Bdo.S1199-B, an evolutionary descendant of Bdo.S1199-A, included a degenerate HE. The above four introns were novel, and were the first group I introns observed and characterized in this species. Differential distribution of these introns revealed that all strains could be separated into four genotypes. Genotype III (no intron and genotype IV (Bdo.S1199-B were each found in only one strain, whereas genotype I (Bdo.S1199-A and genotype II (Bdo.S943 and Bdo.S1506 occurred in 95% of the strains. There is a correlation between B. dothidea genotypes and hosts or geographic locations. Thus, these newly discovered group I introns can help to advance understanding of genetic differentiation within B. dothidea.

  14. Bacterial glycosyltransferase toxins.

    Science.gov (United States)

    Jank, Thomas; Belyi, Yury; Aktories, Klaus

    2015-12-01

    Mono-glycosylation of host proteins is a common mechanism by which bacterial protein toxins manipulate cellular functions of eukaryotic target host cells. Prototypic for this group of glycosyltransferase toxins are Clostridium difficile toxins A and B, which modify guanine nucleotide-binding proteins of the Rho family. However, toxin-induced glycosylation is not restricted to the Clostridia. Various types of bacterial pathogens including Escherichia coli, Yersinia, Photorhabdus and Legionella species produce glycosyltransferase toxins. Recent studies discovered novel unexpected variations in host protein targets and amino acid acceptors of toxin-catalysed glycosylation. These findings open new perspectives in toxin as well as in carbohydrate research.

  15. The 2-Methoxy Group Orientation Regulates the Redox Potential Difference between the Primary (QA) and Secondary (QB) Quinones of Type II Bacterial Photosynthetic Reaction Centers

    Science.gov (United States)

    2015-01-01

    Recent studies have shown that only quinones with a 2-methoxy group can act simultaneously as the primary (QA) and secondary (QB) electron acceptors in photosynthetic reaction centers from purple bacteria such as Rb. sphaeroides. 13C HYSCORE measurements of the 2-methoxy group in the semiquinone states, SQA and SQB, were compared with DFT calculations of the 13C hyperfine couplings as a function of the 2-methoxy dihedral angle. X-ray structure comparisons support 2-methoxy dihedral angle assignments corresponding to a redox potential gap (ΔEm) between QA and QB of 175–193 mV. A model having a methyl group substituted for the 2-methoxy group exhibits no electron affinity difference. This is consistent with the failure of a 2-methyl ubiquinone analogue to function as QB in mutant reaction centers with a ΔEm of ∼160–195 mV. The conclusion reached is that the 2-methoxy group is the principal determinant of electron transfer from QA to QB in type II photosynthetic reaction centers with ubiquinone serving as both acceptor quinones. PMID:25126386

  16. The 2-Methoxy Group Orientation Regulates the Redox Potential Difference between the Primary (QA) and Secondary (QB) Quinones of Type II Bacterial Photosynthetic Reaction Centers.

    Science.gov (United States)

    de Almeida, Wagner B; Taguchi, Alexander T; Dikanov, Sergei A; Wraight, Colin A; O'Malley, Patrick J

    2014-08-07

    Recent studies have shown that only quinones with a 2-methoxy group can act simultaneously as the primary (QA) and secondary (QB) electron acceptors in photosynthetic reaction centers from purple bacteria such as Rb. sphaeroides. (13)C HYSCORE measurements of the 2-methoxy group in the semiquinone states, SQA and SQB, were compared with DFT calculations of the (13)C hyperfine couplings as a function of the 2-methoxy dihedral angle. X-ray structure comparisons support 2-methoxy dihedral angle assignments corresponding to a redox potential gap (ΔEm) between QA and QB of 175-193 mV. A model having a methyl group substituted for the 2-methoxy group exhibits no electron affinity difference. This is consistent with the failure of a 2-methyl ubiquinone analogue to function as QB in mutant reaction centers with a ΔEm of ∼160-195 mV. The conclusion reached is that the 2-methoxy group is the principal determinant of electron transfer from QA to QB in type II photosynthetic reaction centers with ubiquinone serving as both acceptor quinones.

  17. Synthetic interaction between the TipN polarity factor and an AcrAB-family efflux pump implicates cell polarity in bacterial drug resistance.

    Science.gov (United States)

    Kirkpatrick, Clare L; Viollier, Patrick H

    2014-05-22

    Quinolone antibiotics are clinically important drugs that target bacterial DNA replication and chromosome segregation. Although the AcrAB-family efflux pumps generally protect bacteria from such drugs, the physiological role of these efflux systems and their interplay with other cellular events are poorly explored. Here, we report an intricate relationship between antibiotic resistance and cell polarity in the model bacterium Caulobacter crescentus. We show that a polarity landmark protein, TipN, identified by virtue of its ability to direct flagellum placement to the new cell pole, protects cells from toxic misregulation of an AcrAB efflux pump through a cis-encoded nalidixic acid-responsive transcriptional repressor. Alongside the importance of polarity in promoting the inheritance and activity of virulence functions including motility, we can now ascribe to it an additional role in drug resistance that is distinct from classical efflux mechanisms.

  18. Unequal representation of women and men in energy company boards and management groups. Are there implications for mitigation?

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson-Kanyama, A. [Swedish Defence Research Institute, Stockholm (Sweden); Ripa Julia, Isabel [Consultoria Ambiental, Logrono (Spain); Roehr, Ulrike [LIFE e.V, Berlin (Germany)

    2010-08-15

    This survey shows that female representation in boards and management groups of large energy companies in Germany, Spain and Sweden is far from being gender-equal. Of the 464 companies surveyed, 295 (64%) had no women at all in boards or management groups and only 5% could be considered gender-equal by having 40% or more women in such positions. Interviews with energy companies confirmed current trends that gender equality efforts within decision-making in business are weak or non-existent. The findings are discussed against the background of differences in risk perceptions among women and men, evidence of women's impact on boards and companies' performance and the substantial risks related to unabated climate change. Research is suggested for exploring potential impacts on energy companies' performance with more women in the boards when it comes to mitigation activities. (author)

  19. Unequal representation of women and men in energy company boards and management groups: Are there implications for mitigation?

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson-Kanyama, A., E-mail: carlsson@foi.s [Swedish Defence Research Institute, Stockholm (Sweden); Ripa Julia, Isabel [Consultoria Ambiental, Logrono (Spain); Roehr, Ulrike [LIFE e.V, Berlin (Germany)

    2010-08-15

    This survey shows that female representation in boards and management groups of large energy companies in Germany, Spain and Sweden is far from being gender-equal. Of the 464 companies surveyed, 295 (64%) had no women at all in boards or management groups and only 5% could be considered gender-equal by having 40% or more women in such positions. Interviews with energy companies confirmed current trends that gender equality efforts within decision-making in business are weak or non-existent. The findings are discussed against the background of differences in risk perceptions among women and men, evidence of women's impact on boards and companies' performance and the substantial risks related to unabated climate change. Research is suggested for exploring potential impacts on energy companies' performance with more women in the boards when it comes to mitigation activities.

  20. The Use of Case Based Multiple Choice Questions for Assessing Large Group Teaching: Implications on Student's Learning

    Directory of Open Access Journals (Sweden)

    Christina Donnelly

    2014-06-01

    Full Text Available The practice of assessments in third level education is extremely important and a rarely disputed part of the university curriculum as a method to demonstrate a student’s learning. However, assessments to test a student’s knowledge and level of understanding are challenging to apply given recent trends which are showing that student numbers are increasing, student demographics are wide ranging and resources are being stretched. As a result of these emerging challenges, lecturers are required to develop a comprehensive assessment to effectively demonstrate student learning, whilst efficiently managing large class sizes. One form of assessment which has been used for efficient assessment is multiple choice questions (MCQs; however this method has been criticised for encouraging surface learning, in comparison to other methods such as essays or case studies. This research explores the impact of blended assessment methods on student learning. This study adopts a rigorous three-staged qualitative methodology to capture third level lecturers’ and students’ perception to (1 the level of learning when using MCQs; (2 the level of learning when blended assessment in the form of case based MCQs are used. The findings illuminate the positive impact of cased based MCQs as students and lecturers suggest that it leads to a higher level of learning and deeper information processing over that of MCQs without case studies. 2 The implications of this research is that this type of assessment contributes to the current thinking within literature on the use of assessments methods, as well as the blending of assessment methods to reach a higher level of learning. It further serves to reinforce the belief that assessments are the greatest influence on students’ learning, and the requirement for both universities and lecturers to reflect on the best form of assessment to test students’ level of understanding, whilst also balancing the real challenges of

  1. Comparative analysis of the complete mitochondrial genomes of three geographical topmouth culter (Culter alburnus) groups and implications for their phylogenetics.

    Science.gov (United States)

    Shi, Jianwu; Wang, Dexia; Wang, Junhua; Sheng, Junqing; Peng, Kou; Hu, Beijuan; Zeng, Liugen; Xiao, Minghe; Hong, Yijiang

    2017-03-01

    Topmouth culter (C. alburnus) is an important commercial fish in China. We compared the nucleotide variations in the mtDNA genomes among three geographical groups of Culter alburnus: Liangzi Lake, Hubei Province (referred to as LZH); Taihu Lake, Jiangsu Province (TH); and Poyang Lake, Jiangxi Province (PYH). The similarity of whole mtDNA genomes ranged from 0.992 to 0.999. The similarity among 13 protein-coding genes, 2 rRNA genes, and the D-loop sequences was found to range from 0.982 to 0.996. This is useful data for future designing work for making specific molecular marker for distinguishing individuals of C. alburnus from the three geographical groups. An extended termination-associated sequence (ETAS) and several conserved blocks (CSB-F, CSB-E, CSB-D, CSB1, CSB2, and CSB3) were identified in the mtDNA control regions. A phylogenetic analysis shows a monophyletic relationship of the LZF-female and the LZF-male. However, the analysis also showed paraphyletic relationships for the other two geological groups. This result will be useful for the future breeding work of C. alburnus.

  2. Characterization of the spore surface and exosporium proteins of Clostridium sporogenes; implications for Clostridium botulinum group I strains.

    Science.gov (United States)

    Janganan, Thamarai K; Mullin, Nic; Tzokov, Svetomir B; Stringer, Sandra; Fagan, Robert P; Hobbs, Jamie K; Moir, Anne; Bullough, Per A

    2016-10-01

    Clostridium sporogenes is a non-pathogenic close relative and surrogate for Group I (proteolytic) neurotoxin-producing Clostridium botulinum strains. The exosporium, the sac-like outermost layer of spores of these species, is likely to contribute to adhesion, dissemination, and virulence. A paracrystalline array, hairy nap, and several appendages were detected in the exosporium of C. sporogenes strain NCIMB 701792 by EM and AFM. The protein composition of purified exosporium was explored by LC-MS/MS of tryptic peptides from major individual SDS-PAGE-separated protein bands, and from bulk exosporium. Two high molecular weight protein bands both contained the same protein with a collagen-like repeat domain, the probable constituent of the hairy nap, as well as cysteine-rich proteins CsxA and CsxB. A third cysteine-rich protein (CsxC) was also identified. These three proteins are also encoded in C. botulinum Prevot 594, and homologues (75-100% amino acid identity) are encoded in many other Group I strains. This work provides the first insight into the likely composition and organization of the exosporium of Group I C. botulinum spores.

  3. Implication of TLR- but not of NOD2-signaling pathways in dendritic cell activation by group B Streptococcus serotypes III and V.

    Directory of Open Access Journals (Sweden)

    Paul Lemire

    Full Text Available Group B Streptococcus (GBS is an important agent of life-threatening invasive infection. It has been previously shown that encapsulated type III GBS is easily internalized by dendritic cells (DCs, and that this internalization had an impact on cytokine production. The receptors underlying these processes are poorly characterized. Knowledge on the mechanisms used by type V GBS to activate DCs is minimal. In this work, we investigated the role of Toll-like receptor (TLR/MyD88 signaling pathway, the particular involvement of TLR2, and that of the intracellular sensing receptor NOD2 in the activation of DCs by types III and V GBS. The role of capsular polysaccharide (CPS, one of the most important GBS virulence factors in bacterial-DC interactions was evaluated using non-encapsulated mutants. Despite differences in the role of CPS between types III and V GBS in bacterial internalization and intracellular survival, no major differences were observed in their capacity to modulate release of cytokines by DC. For both serotypes, CPS had a minor role in this response. Production of cytokines by DCs was shown to strongly rely on MyD88-dependent signaling pathways, suggesting that DCs recognize GBS and become activated mostly through TLR signaling. Yet, GBS-infected TLR2-/- DCs only showed a partial reduction in the production of IL-6 and CXCL1 compared to control DCs. Surprisingly, CXCL10 release by type III or type V GBS-infected DCs was MyD88-independent. No differences in DC activation were observed between NOD2-/- and control DCs. These results demonstrate the involvement of various receptors and the complexity of the cytokine production pathways activated by GBS upon DC infection.

  4. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    1994-01-01

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, mea

  5. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit...

  6. P-T-t path of metamorphism for the Julin Group and its geodynamical implications in Yuanmou, Yunnan

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The metamorphic complex of the Julin Group occurs in the Yuanmou area of Yunnan Province on the western margin of the Yangtze Platform, and connects with the Kangdian metamorphic complex to the north. Based on the detailed petrographic observations and studies of garnet growth zoning, a P-T-t path has been reconstructed for the staurolite-kyanite zone in the Julin Group. This path is characterized by (1) a counter-clockwise evolutional trend, (2) a quicker increase of temperature than that of pressure in the initial prograde metamorphism, but slower near the peak, then temperature and pressure simultaneously reaching the peak metamorphic conditions, and (3) a slow near-isobaric cooling during the retrograde process. The P-T-t path for prograde metamorphism is closely related to magmatic accretion in the arc setting. The magmatic accretion model, metamorphism type and tectonic setting may be compared with the global Grenville tectono-metamorphic events, and related to the assembly of the Rodinia at the late Meso-proterozoic-early Neoproterozoic (~1.0 Ga). The retrograde P-T-t path shows a slow near-isobaric cooling, indicating sustained heat supplies from the upper mantle and no rapid erosion. This heat source may be originated from the Neoproterozoic (~0.82 Ga) breakup of the Rodinia.

  7. Implications of the nutrition transition for vitamin D intake and status in Aboriginal groups in the Canadian Arctic.

    Science.gov (United States)

    El Hayek Fares, Jessy; Weiler, Hope A

    2016-09-01

    Aboriginal Canadians have low intakes of vitamin D and are shifting away from consumption of traditional foods. Higher body mass index, skin pigmentation, and geographic latitude of residence further predispose Canadian Aboriginal populations to low vitamin D status. Low vitamin D status could compromise bone health and other health outcomes. Studies assessing vitamin D status of different Aboriginal groups are limited. The aim of this review is to examine the literature on vitamin D status and intakes of Canadian Aboriginal populations living in the Arctic. PubMed was searched for relevant articles published from 1983 to 2013. The prevalence of 25-hydroxy vitamin D deficiency ranged from 13.9% to 76.0% among children and adults in the summer. Furthermore, mean vitamin D intakes among all age groups were below the estimated average requirement. As vitamin D deficiency has been recently associated with chronic diseases, and Aboriginal populations living in the Arctic are at high risk for low vitamin D status, their vitamin D status should be assessed regularly across seasons.

  8. Natural Arsenic in the Miocene Hawthorn Group, Florida: Wide Ranging Implications for ASR, Phosphate Mining, Private Well

    Science.gov (United States)

    Lazareva, O. V.; Pichler, T.

    2004-12-01

    In order to understand the mineralogical association and distribution of arsenic (As) in the Hawthorn Group we examined in detail the chemical and mineralogical composition of 370 samples that were collected from 16 cores in central Florida. In our study area the Hawthorn group consists primarily of a basal carbonate unit (the Arcadia Formation) and an upper siliciclastic unit (The Peace River Formation). The Peace River Formation contains appreciable amounts of phosphate and is currently being exploited for phosphate ore. Samples were taken for each Formation at intervals of 25ft. In addition to the interval samples we also took samples that contained visible pyrite crystals, iron oxides, green clays, phosphatic and organic material. These additional samples were collected because of their potential of high As concentrations. Arsenic concentrations were determined by hydride generation - atomic fluorescence spectrometry (HG-AFS) after digestion with aqua regia (3:1 HCl and HNO3). The elements Fe, Na, Al, Si, Mg, Ca, S, P, and K were measured on the same solutions by inductively coupled plasma optical emission spectrometry (ICP-OES). The identification of discrete minerals was aided by scanning electron microscopy (SEM) and chemical compositions were obtained by electron-probe microanalyses (EMPA). Our study indicates that the average As concentrations significantly change from 9.0 ppm in the Peace River Formation to 3.0 ppm in the Tampa Member of the Arcadia Formation. As concentrations for all Hawthorn samples vary from 0.07 to 68.98 ppm ( μ = 5.6, σ = 7.1). Our detailed mineralogical and geochemical study demonstrates that: (1) The As in the Hawthorn group varies from the formation to formation and is mostly concentrated in trace minerals, such as pyrite; (2) Concentrations of the As in pyrite crystals can vary drastically from a minimum of 0 ppm to a maximum of 8260 ppm; (3) Pyrite is an unevenly distributed throughout the Hawthorn Group; (4) Phosphate and

  9. Bacterial community in sediment from the Western Pacific "Warm Pool" and its relationship to environment

    Institute of Scientific and Technical Information of China (English)

    ZENG Runying; ZHAO Jing; ZHANG Rui; LIN Nianwei

    2005-01-01

    Total DNAs were extracted from different sections of deep sea sediment core sample collected from the Western Pacific "Warm Pool". The bacterial 16S ribosomal DNA (rDNA) clone libraries were constructed and analyzed by PCR-restriction fragment length polymorphism (RFLP) and DNA sequencing. The bacterial communities in these samples and their relationship to environment were analyzed consequently. The results indicated that among eight main bacterial groups found in these sediments, members of the γ-Proteobacteria were most abundant in each section of sediment core sample and the genus Colwellia belonging to γ-Proteobacteria was dominant in this area. Members of the α-Proteobacteria were found commonly existing in these samples, while members belonging to β-Proteobacteria were seldom detected. The diversity of bacterial communities from different sections of sediment core sample was δ- and ε-Proteo- bacteria and the bacterial group including genera Cytopahga, Flexibacteria and Bacteroides (CFB group). These bacteria all were inversely proportional to the depth of sediment. Phylogenetic analysis showed that there were 18%-30% and 15%-25% of total bacterial communities related to methane and sulfur metabolism respectively in each section of core sample, implicating that the metabolism of sulfur and methane played an important role in the substance and energy cycles of the Western Pacific "Warm Pool".

  10. P-T-t path of metamorphism for the Julin Group and its geodynamical implications in Yuanmou, Yunnan

    Institute of Scientific and Technical Information of China (English)

    DENG; Shangxian

    2001-01-01

    [1]Liu, T. S., Loess and the Environment, Beijing: China Ocean Press, 1985, 1-251.[2]Chen, L. X., Zhu, Q. G., Luo, H. B. et al., East Asian Monsoon, Beijing: China Meteorology Press, 1991, 28-61.[3]An, Z. S., Liu, T. S., Lu, Y. C. et al., The long-term palaeomonsoon variation recorded by the loess-palaeosol sequence in central China, Quaternary International, 1990, (7/8): 91-95.[4]Guo, Z. T., Liu, T. S., Fedoroff, N. et al., Shift of the monsoon intensity on the Loess Plateau at ca. 0.85 MaBP, Chinese Science Bulletin, 1993, 38(2): 586-591.[5]Chen, J., An, Z. S., Wang, Y. J. et al., Distributions of Rb and Sr in the Luochuan loess-paleosol sequence of China during the last 800 ka: Implications for paleomonsoon variations, Science in China, Ser. D, 1999, 42(3): 225-232.[6]Chen, J., Wang, Y. J., Ji, J. F. et al., Rb/Sr variations and its climatic stratigraphical significance of a loess-paleosol profile from Luochuan, Shaanxi Province, Quaternary Sciences (in Chinese), 1999, 19(4): 350-356.[7]Guo, Z. T.,Liu, T. S., Fedoroff, N. et al., Climate extremes in loess of China coupled with the strength of deep-water for-mation in the North Atlantic, Global and Planetary Change, 1998, 18: 113-128.[8]Guo, Z. T., Liu, T. S., An, Z. S., Paleosols of the last 0.15 Ma in the Weinan loess section and their paleoclimate signifi-cance, Quaternary Sciences (in Chinese), 1994, 14(3): 256-269.[9]Guo, Z, T,, Fedoroff, N., Liu, T. S., Micromorphology of the loess-paleosol sequence of the last 130 ka in China and pa-leoclimatic event, Science in China (in Chinese), Ser. D, 1996, 26(3): 392-398.[10]Guo, Z., Liu, T., Guiot, J., et al., High frequency pulses of East Asian monsoon climate in the last two glaciations: Link with the North Atlantic, Climate Dynamics, 1996, 12: 701-709.[11]Guo, Z. T., Peng, S. Z., Wei, L. Y. et al., Weathering signals of Millennial-Scale oscillations of the East Asian Summer monsoon over the last 220 ka, Chinese Science

  11. Earthquake event deposits in Mesoproterozoic Kunyang Group in central Yunnan Province and its geological impli-cations

    Institute of Scientific and Technical Information of China (English)

    DU; Yuansheng

    2001-01-01

    [1]Liu, T. S., Loess and the Environment, Beijing: China Ocean Press, 1985, 1-251.[2]Chen, L. X., Zhu, Q. G., Luo, H. B. et al., East Asian Monsoon, Beijing: China Meteorology Press, 1991, 28-61.[3]An, Z. S., Liu, T. S., Lu, Y. C. et al., The long-term palaeomonsoon variation recorded by the loess-palaeosol sequence in central China, Quaternary International, 1990, (7/8): 91-95.[4]Guo, Z. T., Liu, T. S., Fedoroff, N. et al., Shift of the monsoon intensity on the Loess Plateau at ca. 0.85 MaBP, Chinese Science Bulletin, 1993, 38(2): 586-591.[5]Chen, J., An, Z. S., Wang, Y. J. et al., Distributions of Rb and Sr in the Luochuan loess-paleosol sequence of China during the last 800 ka: Implications for paleomonsoon variations, Science in China, Ser. D, 1999, 42(3): 225-232.[6]Chen, J., Wang, Y. J., Ji, J. F. et al., Rb/Sr variations and its climatic stratigraphical significance of a loess-paleosol profile from Luochuan, Shaanxi Province, Quaternary Sciences (in Chinese), 1999, 19(4): 350-356.[7]Guo, Z. T.,Liu, T. S., Fedoroff, N. et al., Climate extremes in loess of China coupled with the strength of deep-water for-mation in the North Atlantic, Global and Planetary Change, 1998, 18: 113-128.[8]Guo, Z. T., Liu, T. S., An, Z. S., Paleosols of the last 0.15 Ma in the Weinan loess section and their paleoclimate signifi-cance, Quaternary Sciences (in Chinese), 1994, 14(3): 256-269.[9]Guo, Z, T,, Fedoroff, N., Liu, T. S., Micromorphology of the loess-paleosol sequence of the last 130 ka in China and pa-leoclimatic event, Science in China (in Chinese), Ser. D, 1996, 26(3): 392-398.[10]Guo, Z., Liu, T., Guiot, J., et al., High frequency pulses of East Asian monsoon climate in the last two glaciations: Link with the North Atlantic, Climate Dynamics, 1996, 12: 701-709.[11]Guo, Z. T., Peng, S. Z., Wei, L. Y. et al., Weathering signals of Millennial-Scale oscillations of the East Asian Summer monsoon over the last 220 ka, Chinese Science

  12. Algal—Bacterial Fabrics of Ores and Their Genetic Implications in the Longtang Lead—Zinc Deposit at Yanbian,Sichuan

    Institute of Scientific and Technical Information of China (English)

    帅德权; 张寿庭; 等

    1995-01-01

    The Longtang Pb-Zn deposit occurs in the Upper Sinian Guanyinyan For-mation.The host rocks include sandy shale,cherty limestone and dolomitic limestone.The deposit is a typical one of thallogen origin.The mineral assemblage in the ore is made up of sphalerite, galena, pyrite, enargite, tennantite, seligmannite, asphalt, etc.The ore-forming process is possessed of multi-episode and multi-stage characters. Generally, sphalerites exhibit algal stromatolitic, bac-terial and algal colloidal textures, providing evidence for the direct involvement of alage and bacteria in mineralization of ore-forming elements during sedimentary diagenesis. This is the first transmigration of ore-forming elements.However, pyrite embracing bac-teria and galena replacing/filling trichomes are typical organic textures, which are related to organic carbon and bitumen that can adsorb or reduce ore-forming elements. This is an indirect process of organic mineralization ,ie.,the second transmigration of ore-forming elements.&34S values are all greater than 5%o,indicating the dominance of the heavy sulfur isotopes.The ore-forming temperature deduced from fluid inclusions ranges from 100℃to 150℃±.All this goes to show that the Longtang Pb-Zn deposit is of thallogen origin.

  13. Platinum Group Elements (PGE) geochemistry of komatiites and boninites from Dharwar Craton, India: Implications for mantle melting processes

    Science.gov (United States)

    Saha, Abhishek; Manikyamba, C.; Santosh, M.; Ganguly, Sohini; Khelen, Arubam C.; Subramanyam, K. S. V.

    2015-06-01

    High MgO volcanic rocks having elevated concentrations of Ni and Cr are potential hosts for platinum group elements (PGE) owing to their primitive mantle origin and eruption at high temperatures. Though their higher PGE abundance is economically significant in mineral exploration studies, their lower concentrations are also valuable geochemical tools to evaluate petrogenetic processes. In this paper an attempt has been made to evaluate the PGE geochemistry of high MgO volcanic rocks from two greenstone belts of western and eastern Dharwar Craton and to discuss different mantle processes operative at diverse geodynamic settings during the Neoarchean time. The Bababudan greenstone belt of western and Gadwal greenstone belt of eastern Dharwar Cratons are dominantly composed of high MgO volcanic rocks which, based on distinct geochemical characteristics, have been identified as komatiites and boninites respectively. The Bababudan komatiites are essentially composed of olivine and clinopyroxene with rare plagioclase tending towards komatiitic basalts. The Gadwal boninites contain clinopyroxene, recrystallized hornblende with minor orthopyroxene, plagioclase and sulphide minerals. The Bababudan komatiites are Al-undepleted type (Al2O3/TiO2 = 23-59) with distinctly high MgO (27.4-35.8 wt.%), Ni (509-1066 ppm) and Cr (136-3036 ppm) contents. These rocks have low ΣPGE (9-42 ppb) contents with 0.2-2.4 ppb Iridium (Ir), 0.2-1.4 ppb Osmium (Os) and 0.4-4.4 ppb Ruthenium (Ru) among Iridium group PGE (IPGE); and 1.4-16.2 ppb Platinum (Pt), 2.8-19 ppb Palladium (Pd) and 0.2-9.8 ppb Rhodium (Rh) among Platinum group PGE (PPGE). The Gadwal boninites are high-Ca boninites with CaO/Al2O3 ratios varying between 0.8 and 1.0, with 12-24 wt.% MgO, 821-1168 ppm Ni and 2307-2765 ppm Cr. They show higher concentration of total PGE (82-207 ppb) with Pt concentration ranging from 13 to 19 ppb, Pd between 65 and 180 ppb and Rh in the range of 1.4-3 ppb compared to the Bababudan komatiites. Ir

  14. Carbonate facies of the Upper Triassic Ojo Huelos Member, San Pedro Arroyo Formation (Chinle Group), southern New Mexico: Paleoclimatic implications

    Science.gov (United States)

    Tanner, Lawrence H.; Lucas, Spencer G.

    2012-10-01

    The Upper Triassic (Adamanian LVF) Ojo Huelos Member of the San Pedro Arroyo Formation (Chinle Group) is a distinctive, carbonate-rich unit that occurs in the lower Chinle section of central New Mexico. The member consists mainly of micritic lime mudstones, ostracodal wackestones to grainstones, peloidal grainstones and distinctive pisolitic rudstones, interbedded with fine-grained siliciclastic mudstones. Most limestones exhibit some evidence of pedogenic brecciation and root penetration, and porous fabrics similar to those of modern limestone tufas occur locally. The interbedded mudstones are typically lenticular and commonly display a blocky ped fabric in which subequant peds are separated by sparry calcite veins. Fossils from the Ojo Huelos Member are freshwater (darwinulid) ostracodes, various freshwater fishes and aquatic/amphibious tetrapods-metoposaurs and phytosaurs. We interpret the carbonate facies as the deposits of carbonate lakes, ponds and wetlands that were partly spring-fed, whereas the interbedded and surrounding mudstones were alluvial in origin. The groundwater and overland hydrology of the region was likely controlled by the relative proximity to an upland recharge area in the Mogollon Highlands to the south, but sedimentary fabrics record strong overprinting by desiccation and pedogenic reworking. Consequently, we interpret the Ojo Huelos Member as recording a climate that varied from subhumid to semi-arid, which caused episodic falls in the hydrologic base-level. This resulted in landscape degradation, exemplified by significant pedogenic and erosional reworking of the carbonate sediments and fluvial incision.

  15. Integration host factor assembly at the cohesive end site of the bacteriophage lambda genome: implications for viral DNA packaging and bacterial gene regulation.

    Science.gov (United States)

    Sanyal, Saurarshi J; Yang, Teng-Chieh; Catalano, Carlos Enrique

    2014-12-09

    Integration host factor (IHF) is an Escherichia coli protein involved in (i) condensation of the bacterial nucleoid and (ii) regulation of a variety of cellular functions. In its regulatory role, IHF binds to a specific sequence to introduce a strong bend into the DNA; this provides a duplex architecture conducive to the assembly of site-specific nucleoprotein complexes. Alternatively, the protein can bind in a sequence-independent manner that weakly bends and wraps the duplex to promote nucleoid formation. IHF is also required for the development of several viruses, including bacteriophage lambda, where it promotes site-specific assembly of a genome packaging motor required for lytic development. Multiple IHF consensus sequences have been identified within the packaging initiation site (cos), and we here interrogate IHF-cos binding interactions using complementary electrophoretic mobility shift (EMS) and analytical ultracentrifugation (AUC) approaches. IHF recognizes a single consensus sequence within cos (I1) to afford a strongly bent nucleoprotein complex. In contrast, IHF binds weakly but with positive cooperativity to nonspecific DNA to afford an ensemble of complexes with increasing masses and levels of condensation. Global analysis of the EMS and AUC data provides constrained thermodynamic binding constants and nearest neighbor cooperativity factors for binding of IHF to I1 and to nonspecific DNA substrates. At elevated IHF concentrations, the nucleoprotein complexes undergo a transition from a condensed to an extended rodlike conformation; specific binding of IHF to I1 imparts a significant energy barrier to the transition. The results provide insight into how IHF can assemble specific regulatory complexes in the background of extensive nonspecific DNA condensation.

  16. Crystal structure of Thermotoga maritima TM0439: implications for the mechanism of bacterial GntR transcription regulators with Zn2+-binding FCD domains

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Meiying; Cooper, David; Grossoehmerb, Nickolas; Yu, Minmin; Hung, Li-Wei; Cieslik, Murcin; Derewendaro, Urszula; Lesley, Scott; Wilson, Ian; Giedrocb, David; Derewenda, Zygmunt

    2009-06-06

    The GntR superfamily of dimeric transcription factors, with more than 6200 members encoded in bacterial genomes, are characterized by N-terminal winged helix (WH) DNA-binding domains and diverse C-terminal, regulatory domains, which provide a basis for the classification of the constituent families. The largest of these families, FadR, contains nearly 3000 proteins with all a-helical regulatory domains classified into two related Pfam families: FadR{_}C and FCD. Only two crystal structures of the FadR family members, i.e. the E. coli FadR protein and the LldR from C. glutamicum, have been described to date in literature. Here we describe the crystal structure of TM0439, a GntR regulator with an FCD domain, found in the Thermotoga maritima genome. The FCD domain is similar to that of the LldR regulator, and contains a buried metal binding site. Using atomic absorption spectroscopy and Trp fluorescence, we show that the recombinant protein contains bound Ni{sup 2+} ions, but it is able to bind Zn{sup 2+} with K{sub D} < 70 nM . We conclude that Zn{sup 2+} is the likely physiological metal, where it may perform either or both structural and regulatory roles. Finally, we compare the TM0439 structure to two other FadR family structures recently deposited by Structural Genomics consortia. The results call for a revision in the classification of the FadR family of transcription factors.

  17. Post-breeding movements of Ancient Murrelet Synthliboramphus antiquus family groups, subsequent migration of adults and implications for management

    Science.gov (United States)

    Hashimoto, Yuriko; Wilson, Laurie

    2017-01-01

    Increased shipping in British Columbia (BC) waters poses risks for marine birds from marine oil spills. Ancient Murrelets (Synthliboramphus antiquus), small marine diving birds of which half of the world’s population breeds in BC, are especially susceptible to oiling immediately after departing from their breeding colonies, as their offspring are flightless, constraining their parents to remain with them. In 2014 we deployed geolocator loggers on Ancient Murrelets at four breeding colonies, two on the east and two on the west coast of Haida Gwaii to investigate patterns of post-breeding dispersal and subsequent migratory movements. Birds from east coast colonies moved south and east after leaving their colonies, remaining in Queen Charlotte Sound and adjacent waters for 4–6 weeks, whereas those from west coast colonies moved steadily north and west, so that they left BC waters earlier than those from east coast colonies. These movements were consistent with being driven by surface currents. In June, all birds moved rapidly to the eastern Aleutians, SE Bering Sea, and waters off Kamchatka, where they probably moulted. In August, most moved north, some passing through Bering Straits into the Chukchi Sea. In October-November some birds returned to waters off western N America (33%) and the remainder carried on westwards to waters off Japan, Korea and NE China. For the former group the movement to the Bering Sea in June constituted a moult migration and, as such, is the first described for an auk. Those birds wintering in Asia began moving east in February and arrived off BC in March, when observations at colonies show that burrow visits begin in Haida Gwaii. Our data suggest that, immediately after colony departure, birds from the east coast colonies (about half the population of Haida Gwaii) are at higher risk from potential oil spills in northern British Columbia waters than those breeding on the west coast. PMID:28235033

  18. Deep-water microbialites of the Mesoproterozoic Dismal Lakes Group: microbial growth, lithification, and implications for coniform stromatolites.

    Science.gov (United States)

    Bartley, J K; Kah, L C; Frank, T D; Lyons, T W

    2015-01-01

    Offshore facies of the Mesoproterozoic Sulky Formation, Dismal Lakes Group, arctic Canada, preserve microbialites with unusual morphology. These microbialites grew in water depths greater than several tens of meters and correlate with high-relief conical stromatolites of the more proximal September Lake reef complex. The gross morphology of these microbial facies consists of ridge-like vertical supports draped by concave-upward, subhorizontal elements, resulting in tent-shaped cuspate microbialites with substantial primary void space. Morphological and petrographic analyses suggest a model wherein penecontemporaneous upward growth of ridge elements and development of subhorizontal draping elements initially resulted in a buoyantly supported, unlithified microbial form. Lithification began via precipitation within organic elements during microbialite growth. Mineralization either stabilized or facilitated collapse of initially neutrally buoyant microbialite forms. Microbial structures and breccias were then further stabilized by precipitation of marine herringbone cement. During late-stage diagenesis, remaining void space was occluded by ferroan dolomite cement. Cuspate microbialites are most similar to those found in offshore facies of Neoarchean carbonate platforms and to unlithified, buoyantly supported microbial mats in modern ice-covered Antarctic lakes. We suggest that such unusual microbialite morphologies are a product of the interaction between motile and non-motile communities under nutrient-limiting conditions, followed by early lithification, which served to preserve the resultant microbial form. The presence of marine herringbone cement, commonly associated with high dissolved inorganic carbon (DIC), low O2 conditions, also suggests growth in association with reducing environments at or near the seafloor or in conjunction with a geochemical interface. Predominance of coniform stromatolite forms in the Proterozoic--across a variety of depositional

  19. [Bacterial vaginosis].

    Science.gov (United States)

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists.

  20. 1420 Ma diabasic intrusives from the Mesoproterozoic Singhora Group, Chhattisgarh Supergroup, India: Implications towards non-plume intrusive activity

    Indian Academy of Sciences (India)

    Priyabrata Das; Kaushik Das; Partha Pratim Chakraborty; S Balakrishnan

    2011-04-01

    Besides offering significant clues towards tracking the geochemical evolution of the mantle and architectural reconstruction of different ‘supercontinent’, geochronological and geochemical appraisal of igneous inputs are also important to bracket the depositional time frame of any lithopackage, particularly, the unfossiliferous sedimentary successions. The present study deals with diabasic intrusive within Mesoproterozoic Saraipalli Formation, which is an argillaceous constituent present at the basal part of nearly 400 m thick four-tiered unmetamorphosed but deformed sedimentary succession of Singhora Group, Chhattisgarh Supergroup, central India. The SE–NW trending intrusive comprises mainly of plagioclase and augite together with minor orthopyroxene, biotite and opaque minerals. Though some plagioclase laths are partially sericitized, the ophitic-to-subophitic texture of the rock is well preserved. Major and trace element geochemical data indicate that this intrusive is basalt-to-basaltic andesite in character and of subalkaline basalt affinity. Multi-element plot shows overall LILE-enrichment and enrichment of Pb and slight depletion of Nb and P, coupled with moderate La/Nb and Th/Nb ratios. Zr, Y and Nb ternary diagrams plot in the fields of within plate basalt. Selected HFSE ratios indicate a non-plume source with crustal assimilation/sediment mixing. Sm–Nd and Rb–Sr isotope data show that the intrusive has Srinitial and Ndinitial of 0.709377–0.706672 and 0.510919–0.510815, respectively. Positive tNd [t = 1420 Ma] values (+0.3 to + 2.3) indicate depleted isotopic nature of their protolith. The calculated DM age is 1.7–1.9 Ga. The mineral-whole rock isochron data (Sm–Nd systematics) of the intrusive implies an emplacement age of ca. 1420 Ma. Considering synchronous terrain boundary shear zone development in Bastar craton on the southeastern part of the Singhora basin, mafic magmatism in Eastern Ghats and large-scale basic intrusion in Sausar

  1. Phylogenetic Diversity, Localization, and Cell Morphologies of Members of the Candidate Phylum TG3 and a Subphylum in the Phylum Fibrobacteres, Recently Discovered Bacterial Groups Dominant in Termite Guts▿ †

    Science.gov (United States)

    Hongoh, Yuichi; Deevong, Pinsurang; Hattori, Satoshi; Inoue, Tetsushi; Noda, Satoko; Noparatnaraporn, Napavarn; Kudo, Toshiaki; Ohkuma, Moriya

    2006-01-01

    Recently we discovered two novel, deeply branching lineages in the domain Bacteria from termite guts by PCR-based analyses of 16S rRNA (Y. Hongoh, P. Deevong, T. Inoue, S. Moriya, S. Trakulnaleamsai, M. Ohkuma, C. Vongkaluang, N. Noparatnaraporn, and T. Kudo, Appl. Environ. Microbiol. 71:6590-6599, 2005). Here, we report on the specific detection of these bacteria, the candidate phylum TG3 (Termite Group 3) and a subphylum in the phylum Fibrobacteres, by fluorescence in situ hybridization in the guts of the wood-feeding termites Microcerotermes sp. and Nasutitermes takasagoensis. Both bacterial groups were detected almost exclusively from the luminal fluid of the dilated portion in the hindgut. Each accounted for approximately 10% of the total prokaryotic cells, constituting the second-most dominant groups in the whole-gut microbiota. The detected cells of both groups were in undulate or vibroid forms and apparently resembled small spirochetes. The cell sizes were 0.2 to 0.4 by 1.3 to 6.0 μm and 0.2 to 0.3 by 1.3 to 4.9 μm in the TG3 and Fibrobacteres, respectively. Using PCR screenings with specific primers, we found that both groups are distributed among various termites. The obtained clones formed monophyletic clusters that were delineated by the host genus rather than by the geographic distance, implying a robust association between these bacteria and host termites. TG3 clones were also obtained from a cockroach gut, lake sediment, rice paddy soil, and deep-sea sediments. Our results suggest that the TG3 and Fibrobacteres bacteria are autochthonous gut symbionts of various termites and that the TG3 members are also widely distributed among various other environments. PMID:17021231

  2. Phylogenetic diversity, localization, and cell morphologies of members of the candidate phylum TG3 and a subphylum in the phylum Fibrobacteres, recently discovered bacterial groups dominant in termite guts.

    Science.gov (United States)

    Hongoh, Yuichi; Deevong, Pinsurang; Hattori, Satoshi; Inoue, Tetsushi; Noda, Satoko; Noparatnaraporn, Napavarn; Kudo, Toshiaki; Ohkuma, Moriya

    2006-10-01

    Recently we discovered two novel, deeply branching lineages in the domain Bacteria from termite guts by PCR-based analyses of 16S rRNA (Y. Hongoh, P. Deevong, T. Inoue, S. Moriya, S. Trakulnaleamsai, M. Ohkuma, C. Vongkaluang, N. Noparatnaraporn, and T. Kudo, Appl. Environ. Microbiol. 71:6590-6599, 2005). Here, we report on the specific detection of these bacteria, the candidate phylum TG3 (Termite Group 3) and a subphylum in the phylum Fibrobacteres, by fluorescence in situ hybridization in the guts of the wood-feeding termites Microcerotermes sp. and Nasutitermes takasagoensis. Both bacterial groups were detected almost exclusively from the luminal fluid of the dilated portion in the hindgut. Each accounted for approximately 10% of the total prokaryotic cells, constituting the second-most dominant groups in the whole-gut microbiota. The detected cells of both groups were in undulate or vibroid forms and apparently resembled small spirochetes. The cell sizes were 0.2 to 0.4 by 1.3 to 6.0 microm and 0.2 to 0.3 by 1.3 to 4.9 microm in the TG3 and Fibrobacteres, respectively. Using PCR screenings with specific primers, we found that both groups are distributed among various termites. The obtained clones formed monophyletic clusters that were delineated by the host genus rather than by the geographic distance, implying a robust association between these bacteria and host termites. TG3 clones were also obtained from a cockroach gut, lake sediment, rice paddy soil, and deep-sea sediments. Our results suggest that the TG3 and Fibrobacteres bacteria are autochthonous gut symbionts of various termites and that the TG3 members are also widely distributed among various other environments.

  3. Bacterial Flora of the Female Genital Tract

    Directory of Open Access Journals (Sweden)

    Pongsakdi Chaisilwattana

    1995-01-01

    Full Text Available Objective: The purpose of this study was to analyze the ability of septicemic and nonsepticemic isolates of group B streptococci (GBS to inhibit in vitro the principal bacterial groups found in the normal bacterial flora of the female genital tract.

  4. Distribution of HNA and LNA bacterial groups in the Southwest Atlantic Ocean Distribuição de bactérias HNA e LNA no Oceano Atlântico sudoeste

    Directory of Open Access Journals (Sweden)

    Luciana Andrade

    2007-06-01

    Full Text Available Bacterioplankton was studied in a large area of Southwest Atlantic Ocean between 13 and 25ºS and 28 and 42ºW. Samples were collected in 108 stations at 20 m depth. Bacteria were enumerated by flow cytometry after nucleic acid staining with syto13 and two subgroups were differentiated: low nucleic acid content (LNA and high nucleic acid content (HNA bacteria. Total bacterial numbers varied from 0.37 to 5.53 10(5 cells mL-1. HNA cells represented 15 to 70% of the total number while LNA cells represented 30 to 85%. Heterotrophic bacterial production was determined by incorporation of tritiated leucine and ranged from 2.7 to 171.07 ng C L-1 h-1. No significant correlation was found between abundance and production. Nevertheless with support of multivariate analysis between bacterial abundance, bacterial production, chlorophyll a and other oceanographic data the distribution of the groups in two different oceanic provinces could be explained by nutrient availability. HNA bacteria accounted for the high percentage of cells found in the area north of 19ºS, linked to higher temperature waters and riverine nutrients inputs. LNA bacteria were the dominant cells south of this latitude and were correlated to the higher values of nitrate found for the same area.Um estudo do bacterioplâncton foi realizado numa área extensa do Oceano Atlântico Sudoeste entre 13 e 25ºS e 28 e 42ºW. As amostras foram coletadas em 108 estações oceanográficas a 20 m de profundidade. A abundância bacteriana foi determinada por citometria de fluxo após coloração dos ácidos nucléicos com Syto13. Dois grupos de bactérias foram enumerados e distinguidos: bactérias com alto conteúdo de ácidos nucleicos (HNA e bactérias com baixo conteúdo de ácidos nucleicos (LNA. O número de bactérias variou de 0,37 a 5,53 10(5 células mL-1. As células HNA representaram de 15 a 70% da abundância total enquanto as células LNA representaram de 30 a 85%. A produ

  5. Neglected bacterial zoonoses.

    Science.gov (United States)

    Chikeka, I; Dumler, J S

    2015-05-01

    Bacterial zoonoses comprise a group of diseases in humans or animals acquired by direct contact with or by oral consumption of contaminated animal materials, or via arthropod vectors. Among neglected infections, bacterial zoonoses are among the most neglected given emerging data on incidence and prevalence as causes of acute febrile illness, even in areas where recognized neglected tropical diseases occur frequently. Although many other bacterial infections could also be considered in this neglected category, five distinct infections stand out because they are globally distributed, are acute febrile diseases, have high rates of morbidity and case fatality, and are reported as commonly as malaria, typhoid or dengue virus infections in carefully designed studies in which broad-spectrum diagnoses are actively sought. This review will focus attention on leptospirosis, relapsing fever borreliosis and rickettsioses, including scrub typhus, murine typhus and spotted fever group rickettsiosis. Of greatest interest is the lack of distinguishing clinical features among these infections when in humans, which confounds diagnosis where laboratory confirmation is lacking, and in regions where clinical diagnosis is often attributed to one of several perceived more common threats. As diseases such as malaria come under improved control, the real impact of these common and under-recognized infections will become evident, as will the requirement for the strategies and allocation of resources for their control.

  6. Bacterial hydrodynamics

    CERN Document Server

    Lauga, Eric

    2015-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells yet they represent the bulk of the world's biomass, and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds-number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micron scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically-complex environments. Using hydrodynamics as an organizing framework, we review the biomechanics of bacterial motility and look ahead to future challenges.

  7. Bacterial Colony Optimization

    Directory of Open Access Journals (Sweden)

    Ben Niu

    2012-01-01

    Full Text Available This paper investigates the behaviors at different developmental stages in Escherichia coli (E. coli lifecycle and developing a new biologically inspired optimization algorithm named bacterial colony optimization (BCO. BCO is based on a lifecycle model that simulates some typical behaviors of E. coli bacteria during their whole lifecycle, including chemotaxis, communication, elimination, reproduction, and migration. A newly created chemotaxis strategy combined with communication mechanism is developed to simplify the bacterial optimization, which is spread over the whole optimization process. However, the other behaviors such as elimination, reproduction, and migration are implemented only when the given conditions are satisfied. Two types of interactive communication schemas: individuals exchange schema and group exchange schema are designed to improve the optimization efficiency. In the simulation studies, a set of 12 benchmark functions belonging to three classes (unimodal, multimodal, and rotated problems are performed, and the performances of the proposed algorithms are compared with five recent evolutionary algorithms to demonstrate the superiority of BCO.

  8. Pattern of injury mortality by age-group in children aged 0–14 years in Scotland, 2002–2006, and its implications for prevention

    Directory of Open Access Journals (Sweden)

    Stone David H

    2009-04-01

    Full Text Available Abstract Background Knowledge of the epidemiology of injuries in children is essential for the planning, implementation and evaluation of preventive measures but recent epidemiological information on injuries in children both in general and by age-group in Scotland is scarce. This study examines the recent pattern of childhood mortality from injury by age-group in Scotland and considers its implications for prevention. Methods Routine mortality data for the period 2002–2006 were obtained from the General Register Office for Scotland and were analysed in terms of number of deaths, mean annual mortality rates per 100,000 population, leading causes of death, and causes of injury death. Mid-year population estimates were used as the denominator. Chi-square tests were used to determine statistical significance. Results 186 children aged 0–14 died from an injury in Scotland during 2002–06 (MR 4.3 per 100,000. Injuries were the leading cause of death in 1–14, 5–9 and 10–14 year-olds (causing 25%, 29% and 32% of all deaths respectively. The leading individual causes of injury death (0–14 years were pedestrian and non-pedestrian road-traffic injuries and assault/homicide but there was variation by age-group. Assault/homicide, fire and suffocation caused most injury deaths in young children; road-traffic injuries in older ones. Collectively, intentional injuries were a bigger threat to the lives of under-15s than any single cause of unintentional injury. The mortality rate from assault/homicide was highest in infants ( Conclusion Injuries continue to be a leading cause of death in childhood in Scotland. Variation in causes of injury death by age-group is important when targeting preventive efforts. In particular, the threats of assault/homicide in infants, fire in 1–4 year-olds, pedestrian injury in 5–14 year-olds, and suicide in 10–14 year-olds need urgent consideration for preventive action.

  9. Bacterial vaginosis -- aftercare

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000687.htm Bacterial vaginosis - aftercare To use the sharing features on this ... to back after you use the bathroom. Preventing Bacterial Vaginosis You can help prevent bacterial vaginosis by: Not ...

  10. Pregnancy Complications: Bacterial Vaginosis

    Science.gov (United States)

    ... Complications & Loss > Pregnancy complications > Bacterial vaginosis and pregnancy Bacterial vaginosis and pregnancy E-mail to a friend Please ... this page It's been added to your dashboard . Bacterial vaginosis (also called BV or vaginitis) is an infection ...

  11. Exploration and mining of the bacterial terpenome.

    Science.gov (United States)

    Cane, David E; Ikeda, Haruo

    2012-03-20

    Tens of thousands of terpenoids are present in both terrestrial and marine plants, as well as fungi. In the last 5-10 years, however, it has become evident that terpenes are also produced by numerous bacteria, especially soil-dwelling Gram-positive organisms such as Streptomyces and other Actinomycetes. Although some microbial terpenes, such as geosmin, the degraded sesquiterpene responsible for the smell of moist soil, the characteristic odor of the earth itself, have been known for over 100 years, few terpenoids have been identified by classical structure- or activity-guided screening of bacterial culture extracts. In fact, the majority of cyclic terpenes from bacterial species have only recently been uncovered by the newly developed techniques of "genome mining". In this new paradigm for biochemical discovery, bacterial genome sequences are first analyzed with powerful bioinformatic tools, such as the BLASTP program or Profile Hidden Markov models, to screen for and identify conserved protein sequences harboring a characteristic set of universally conserved functional domains typical of all terpene synthases. Of particular importance is the presence of variants of two universally conserved domains, the aspartate-rich DDXX(D/E) motif and the NSE/DTE triad, (N/D)DXX(S/T)XX(K/R)(D/E). Both domains have been implicated in the binding of the essential divalent cation, typically Mg(2+), that is required for cyclization of the universal acyclic terpene precursors, such as farnesyl and geranyl diphosphate. The low level of overall sequence similarity among terpene synthases, however, has so far precluded any simple correlation of protein sequence with the structure of the cyclized terpene product. The actual biochemical function of a cryptic bacterial (or indeed any) terpene synthase must therefore be determined by direct experiment. Two common approaches are (i) incubation of the expressed recombinant protein with acyclic allylic diphosphate substrates and

  12. Fracture characterization and discrimination criteria for karst and tectonic fractures in the Ellenburger Group, West Texas: Implications for reservoir and exploration models

    Energy Technology Data Exchange (ETDEWEB)

    Hoak, T.E. [Science Applications International Corp., Germantown, MD (United States)]|[Kestrel Geoscience, Littleton, CO (United States); Sundberg, K.R. [Phillips Petroleum Co., Bartlesville, OK (United States); Deyhim, P. [Oklahoma State Univ., Stillwater, OK (United States); Ortoleva, P. [Indiana Univ., Bloomington, IN (United States). Lab. for Computational Geodynamics

    1998-12-31

    In the Ellenburger Group fractured dolomite reservoirs of West Texas, it is extremely difficult to distinguish between multiple phases of karst-related fracturing, modifications to the karst system during burial, and overprinting tectonic fractures. From the analyses of drill core, the authors developed criteria to distinguish between karst and tectonic fractures. In addition, they have applied these criteria within the context of a detailed diagenetic cement history that allows them to further refine the fracture genesis and chronology. In these analyses, the authors evaluated the relationships between fracture intensity, morphologic attributes, host lithology, fracture cement, and oil-staining. From this analysis, they have been able to characterize variations in Ellenburger tectonic fracture intensity by separating these fractures from karst-related features. In general, the majority of fracturing in the Ellenburger is caused by karst-related fracturing although a considerable percentage is caused by tectonism. These findings underscore the importance of considering the complete geologic evolution of a karst reservoir during exploration and field development programs. The authors have been able to more precisely define the spatial significance of the fracture data sets by use of oriented core from Andector Field. They have also demonstrated the importance of these results for exploration and reservoir development programs in West Texas, and the potential to extrapolate these results around the globe. Given the historic interest in the large hydrocarbon reserves in West Texas carbonate reservoirs, results of this study will have tremendous implications for exploration and production strategies targeting vuggy, fractured carbonate systems not only in West Texas, but throughout the globe.

  13. Bacterial Degradation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Qing X. Li

    2009-01-01

    Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

  14. Bacterial gut symbionts contribute to seed digestion in an omnivorous beetle.

    Directory of Open Access Journals (Sweden)

    Jonathan G Lundgren

    Full Text Available BACKGROUND: Obligate bacterial symbionts alter the diets of host animals in numerous ways, but the ecological roles of facultative bacterial residents that colonize insect guts remain unclear. Carabid beetles are a common group of beneficial insects appreciated for their ability to consume insect prey and seeds, but the contributions of microbes to diet diversification in this and similar groups of facultative granivores are largely unknown. METHODOLOGY AND PRINCIPAL FINDINGS: Using 16S rRNA gene clone libraries and terminal restriction fragment (tRF length polymorphism analyses of these genes, we examined the bacterial communities within the guts of facultatively granivorous, adult Harpalus pensylvanicus (Carabidae, fed one of five dietary treatments: 1 an untreated Field population, 2 Seeds with antibiotics (seeds were from Chenopodium album, 3 Seeds without antibiotics, 4 Prey with antibiotics (prey were Acheta domesticus eggs, and 5 Prey without antibiotics. The number of seeds and prey consumed by each beetle were recorded following treatment. Harpalus pensylvanicus possessed a fairly simple gut community of approximately 3-4 bacterial operational taxonomic units (OTU per beetle that were affiliated with the Gammaproteobacteria, Bacilli, Alphaproteobacteria, and Mollicutes. Bacterial communities of the host varied among the diet and antibiotic treatments. The field population and beetles fed seeds without antibiotics had the closest matching bacterial communities, and the communities in the beetles fed antibiotics were more closely related to each other than to those of the beetles that did not receive antibiotics. Antibiotics reduced and altered the bacterial communities found in the beetle guts. Moreover, beetles fed antibiotics ate fewer seeds, and those beetles that harbored the bacterium Enterococcus faecalis consumed more seeds on average than those lacking this symbiont. CONCLUSIONS/SIGNIFICANCE: We conclude that the relationships

  15. The Bero Volganic Group: New Lithological, Stratigraphic, and Geochemical Data of this Extension of the Parana-Etendeka Igneous Province into SW Angola with Implications

    Science.gov (United States)

    Marsh, J.; Swart, R.

    2015-12-01

    The Bero Volcanic Group, an extension of the Etendeka-Paraná Igneous Province into SW Angola, forms the eroded basement to the on-shore Namibe Basin, an Early Cretaceous-Cenozoic terrestrial and marine sedimentary sequence. The igneous suite outcrops between latitudes 14.68o and 15.25o S and comprises quartz latite rheoignimbrites/lavas, tholeiitic basaltic lavas, pyroclastic/volcaniclastic deposits, minor aeolian sandstones, and mafic tholeiitic dykes and gabbroic sheets. Quartz latite lithologies dominate. In the Rio Bero area in the S quartz latites are underlain by several thin flows of basalt interbedded with, and underlain by, thin discontinuous lenses of aeolian sandstone. This sequence is consistent with the general stratigraphic sequence in the northern Etendeka of Namibia. To the N basalts and aeolian sandstones are absent and the quartz latites lie directly on Precambrian basement rocks in places. To date, data for a quartz latite correlated with a Chapecó rhyolites of the Paraná are available from only one locality in Angola. This study's wider sampling and major and trace element and radiogenic isotope analysis reveals the following: (1) all mafic rocks are high-Ti, the lavas being equivalent to the Khumiba/Urubici type; (2) mafic dykes cutting the quartz latites having affinities to the Paranapanema-Ribeira mafic lavas; (3) five quartz latite geochemical types are present, three of which are known from Etendeka/Paraná (Sarusas/Guarapuava, Khoraseb/Ourinhos and Ventura) and their stratigraphic relationships in Angola are consistent with those in the Etendeka and Paraná; (4) their Angolan occurrence significantly extends the area covered by, and potential eruptive volumes of, these silicic types; (5) two other quartz latite types are unknown in the Etendeka and Paraná and are probably products of low-volume, local eruptions. The Chinguau type is geochemically similar to the low-Ti quartz lalites of the southern Etendeka but has lower Epsilon Nd

  16. Deoxygenation alters bacterial diversity and community composition in the ocean's largest oxygen minimum zone.

    Science.gov (United States)

    Beman, J Michael; Carolan, Molly T

    2013-01-01

    Oceanic oxygen minimum zones (OMZs) have a central role in biogeochemical cycles and are expanding as a consequence of climate change, yet how deoxygenation will affect the microbial communities that control these cycles is unclear. Here we sample across dissolved oxygen gradients in the oceans' largest OMZ and show that bacterial richness displays a unimodal pattern with decreasing dissolved oxygen, reaching maximum values on the edge of the OMZ and decreasing within it. Rare groups on the OMZ margin are abundant at lower dissolved oxygen concentrations, including sulphur-cycling Chromatiales, for which 16S rRNA was amplified from extracted RNA. Microbial species distribution models accurately replicate community patterns based on multivariate environmental data, demonstrate likely changes in distributions and diversity in the eastern tropical North Pacific Ocean, and highlight the sensitivity of key bacterial groups to deoxygenation. Through these mechanisms, OMZ expansion may alter microbial composition, competition, diversity and function, all of which have implications for biogeochemical cycling in OMZs.

  17. Collective Functionality through Bacterial Individuality

    Science.gov (United States)

    Ackermann, Martin

    According to the conventional view, the properties of an organism are a product of nature and nurture - of its genes and the environment it lives in. Recent experiments with unicellular organisms have challenged this view: several molecular mechanisms generate phenotypic variation independently of environmental signals, leading to variation in clonal groups. My presentation will focus on the causes and consequences of this microbial individuality. Using examples from bacterial genetic model systems, I will first discuss different molecular and cellular mechanisms that give rise to bacterial individuality. Then, I will discuss the consequences of individuality, and focus on how phenotypic variation in clonal populations of bacteria can promote interactions between individuals, lead to the division of labor, and allow clonal groups of bacteria to cope with environmental uncertainty. Variation between individuals thus provides clonal groups with collective functionality.

  18. Soil carbon quality and nitrogen fertilization structure bacterial communities with predictable responses of major bacterial phyla

    OpenAIRE

    2014-01-01

    Agricultural practices affect the soil ecosystem in multiple ways and the soil microbial communities represent an integrated and dynamic measure of soil status. Our aim was to test whether the soil bacterial community and the relative abundance of major bacterial phyla responded predictably to long-term organic amendments representing different carbon qualities (peat and straw) in combination with nitrogen fertilization levels and if certain bacterial groups were indicative of specific treatm...

  19. Comprehensive phylogenetic analysis of bacterial reverse transcriptases.

    Directory of Open Access Journals (Sweden)

    Nicolás Toro

    Full Text Available Much less is known about reverse transcriptases (RTs in prokaryotes than in eukaryotes, with most prokaryotic enzymes still uncharacterized. Two surveys involving BLAST searches for RT genes in prokaryotic genomes revealed the presence of large numbers of diverse, uncharacterized RTs and RT-like sequences. Here, using consistent annotation across all sequenced bacterial species from GenBank and other sources via RAST, available from the PATRIC (Pathogenic Resource Integration Center platform, we have compiled the data for currently annotated reverse transcriptases from completely sequenced bacterial genomes. RT sequences are broadly distributed across bacterial phyla, but green sulfur bacteria and cyanobacteria have the highest levels of RT sequence diversity (≤85% identity per genome. By contrast, phylum Actinobacteria, for which a large number of genomes have been sequenced, was found to have a low RT sequence diversity. Phylogenetic analyses revealed that bacterial RTs could be classified into 17 main groups: group II introns, retrons/retron-like RTs, diversity-generating retroelements (DGRs, Abi-like RTs, CRISPR-Cas-associated RTs, group II-like RTs (G2L, and 11 other groups of RTs of unknown function. Proteobacteria had the highest potential functional diversity, as they possessed most of the RT groups. Group II introns and DGRs were the most widely distributed RTs in bacterial phyla. Our results provide insights into bacterial RT phylogeny and the basis for an update of annotation systems based on sequence/domain homology.

  20. The bacterial lux reporter system: applications in bacterial localisation studies.

    Science.gov (United States)

    Gahan, Cormac G M

    2012-02-01

    Bacterial production of visible light is a natural phenomenon occurring in marine (Vibrio and Photobacterium) and terrestrial (Photorhabdus) species. The mechanism underpinning light production in these organisms is similar and involves the oxidation of an aldehyde substrate in a reaction catalysed by the bacterial luciferase enzyme. The genes encoding the luciferase and a fatty acid reductase complex which synthesizes the substrate are contained in a single operon (the lux operon). This provides a useful reporter system as cloning the operon into a recipient host bacterium will generate visible light without the requirement to add exogenous substrate. The light can be detected in vivo in the living animal using a sensitive detection system and is therefore ideally suited to bioluminescence imaging protocols. The system has therefore been widely used to track bacteria during infection or colonisation of the host. As bacteria are currently being examined as bactofection vectors for gene delivery, particularly to tumour tissue, the use of bioluminescence imaging offers a powerful means to investigate vector amplification in situ. The implications of this technology for bacterial localization, tumour targeting and gene transfer (bactofection) studies are discussed.

  1. 耐热石油降解混合菌群的降解性能研究%Study on Degrading Performance of A Thermophilic Oil-Degrading Bacterial Group

    Institute of Scientific and Technical Information of China (English)

    李政; 赵朝成; 张云波; 刘春爽; 赵东风

    2011-01-01

    针对极端环境下石油污染土壤的生物修复,从克拉玛依油田石油污染土壤中筛选获得一组最适生长温度为45~55℃、最高耐受温度为75℃的耐热石油降解混合菌群KLO-8,该混合菌群由4株单菌组成,16S rDNA序列分析鉴定表明,其中3株为芽孢杆菌(Bacillus sp.)、1株为地芽孢杆菌(Geobacillus sp.).考察了KLO-8的降解性能,结果表明:最佳培养时间为7d;最佳氮磷比为3:1;初始pH值偏碱性更利于原油的降解,最佳初始pH值为8;原油浓度不高于10 g·L-1时降解效果较好;添加表面活性剂(十二烷基苯磺酸钠)能够提高混合菌群的降油效果,最佳添加浓度为50mg·L-1.气相色谱—模拟蒸馏分析结果表明,KLO-8对C11~C37的正构烷烃降解效果显著,随着碳原子数的增加,混合菌群对原油中正构烷烃的利用率逐渐降低.%For bioremediation of oil-contaminated soil under extreme conditions,a thermophilic oil-degrading bacterial group KLO-8 composed of four single strains was isolated from Karamay Oilfield oil-contaminated soil. Its optimal growth temperature was 45 - 55 °C ,and its highest resistant temperature was 75℃. Based on 16S rDNA sequence analysis, three single strains of KLO-8 was Bacillus sp. , one strain was Geobacillus sp.. The degrading performance of KLO-8 were discussed. The results showed that the optimal culture time was 7 d,the optimal nitrogen-phosphorus ratio was 3∶1,the initial pH value leaning alkalinity was more propitious to crude oil degradation and the optimal initial pH value was 8,the crude oil concentration below 10 g· L-1 was suitable,the addition of surfactant (sodium dodecyl benzene sulfonate) was able to improve the crude oil degradation rate and the optimal concentration was 50 mg ·L-1. Gas chromatogram-simulation distillation analysis result showed that KLO-8 was able to degrade the n-alkanes ranging from C11 to C37 and the degradation decreased with the long-chain alkanes

  2. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach...... that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become...

  3. Diverse bacterial PKS sequences derived from okadaic acid-producing dinoflagellates.

    Science.gov (United States)

    Perez, Roberto; Liu, Li; Lopez, Jose; An, Tianying; Rein, Kathleen S

    2008-05-22

    Okadaic acid (OA) and the related dinophysistoxins are isolated from dinoflagellates of the genus Prorocentrum and Dinophysis. Bacteria of the Roseobacter group have been associated with okadaic acid producing dinoflagellates and have been previously implicated in OA production. Analysis of 16S rRNA libraries reveals that Roseobacter are the most abundant bacteria associated with OA producing dinoflagellates of the genus Prorocentrum and are not found in association with non-toxic dinoflagellates. While some polyketide synthase (PKS) genes form a highly supported Prorocentrum clade, most appear to be bacterial, but unrelated to Roseobacter or Alpha-Proteobacterial PKSs or those derived from other Alveolates Karenia brevis or Crytosporidium parvum.

  4. Oral bacterial DNA findings in pericardial fluid

    Directory of Open Access Journals (Sweden)

    Anne-Mari Louhelainen

    2014-11-01

    Full Text Available Background: We recently reported that large amounts of oral bacterial DNA can be found in thrombus aspirates of myocardial infarction patients. Some case reports describe bacterial findings in pericardial fluid, mostly done with conventional culturing and a few with PCR; in purulent pericarditis, nevertheless, bacterial PCR has not been used as a diagnostic method before. Objective: To find out whether bacterial DNA can be measured in the pericardial fluid and if it correlates with pathologic–anatomic findings linked to cardiovascular diseases. Methods: Twenty-two pericardial aspirates were collected aseptically prior to forensic autopsy at Tampere University Hospital during 2009–2010. Of the autopsies, 10 (45.5% were free of coronary artery disease (CAD, 7 (31.8% had mild and 5 (22.7% had severe CAD. Bacterial DNA amounts were determined using real-time quantitative PCR with specific primers and probes for all bacterial strains associated with endodontic disease (Streptococcus mitis group, Streptococcus anginosus group, Staphylococcus aureus/Staphylococcus epidermidis, Prevotella intermedia, Parvimonas micra and periodontal disease (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Fusobacterium nucleatus, and Dialister pneumosintes. Results: Of 22 cases, 14 (63.6% were positive for endodontic and 8 (36.4% for periodontal-disease-associated bacteria. Only one case was positive for bacterial culturing. There was a statistically significant association between the relative amount of bacterial DNA in the pericardial fluid and the severity of CAD (p=0.035. Conclusions: Oral bacterial DNA was detectable in pericardial fluid and an association between the severity of CAD and the total amount of bacterial DNA in pericardial fluid was found, suggesting that this kind of measurement might be useful for clinical purposes.

  5. Effect of isolate of ruminal fibrolytic bacterial culture supplementation on fibrolytic bacterial population and survivability of inoculated bacterial strain in lactating Murrah buffaloes

    Directory of Open Access Journals (Sweden)

    Brishketu Kumar

    2013-02-01

    Full Text Available Aim: The present study was conducted to evaluate the effect of bacterial culture supplementation on ruminal fibrolytic bacterial population as well as on survivability of inoculated bacterial strain in lactating Murrah buffaloes kept on high fibre diet. Materials and Methods: Fibrolytic bacterial strains were isolated from rumen liquor of fistulated Murrah buffaloes and live bacterial culture were supplemented orally in treatment group of lactating Murrah buffaloes fed on high fibre diet to see it's effect on ruminal fibrolytic bacterial population as well as to see the effect of survivability of the inoculated bacterial strain at three different time interval in comparison to control group. Results: It has been shown by real time quantification study that supplementation of bacterial culture orally increases the population of major fibre degrading bacteria i.e. Ruminococcus flavefaciens, Ruminococcus albus as well as Fibrobacter succinogenes whereas there was decrease in secondary fibre degrading bacterial population i.e. Butyrivibrio fibrisolvens over the different time periods. However, the inoculated strain of Ruminococcus flavefaciens survived significantly over the period of time, which was shown in stability of increased inoculated bacterial population. Conclusion: The isolates of fibrolytic bacterial strains are found to be useful in increasing the number of major ruminal fibre degrading bacteria in lactating buffaloes and may act as probiotic in large ruminants on fibre-based diets. [Vet World 2013; 6(1.000: 14-17

  6. Biotechnological applications of bacterial cellulases

    Directory of Open Access Journals (Sweden)

    Esther Menendez

    2015-08-01

    Full Text Available Cellulases have numerous applications in several industries, including biofuel production, food and feed industry, brewing, pulp and paper, textile, laundry, and agriculture.Cellulose-degrading bacteria are widely spread in nature, being isolated from quite different environments. Cellulose degradation is the result of a synergic process between an endoglucanase, an exoglucanase and a,β-glucosidase. Bacterial endoglucanases degrade ß-1,4-glucan linkages of cellulose amorphous zones, meanwhile exoglucanases cleave the remaining oligosaccharide chains, originating cellobiose, which is hydrolyzed by ß-glucanases. Bacterial cellulases (EC 3.2.1.4 are comprised in fourteen Glycosil Hydrolase families. Several advantages, such as higher growth rates and genetic versatility, emphasize the suitability and advantages of bacterial cellulases over other sources for this group of enzymes. This review summarizes the main known cellulolytic bacteria and the best strategies to optimize their cellulase production, focusing on endoglucanases, as well as it reviews the main biotechnological applications of bacterial cellulases in several industries, medicine and agriculture.

  7. Jellyfish modulate bacterial dynamic and community structure.

    Science.gov (United States)

    Tinta, Tinkara; Kogovšek, Tjaša; Malej, Alenka; Turk, Valentina

    2012-01-01

    bacterial population dynamics and nutrient pathways following jellyfish blooms which have important implications for ecology of coastal waters.

  8. Jellyfish modulate bacterial dynamic and community structure.

    Directory of Open Access Journals (Sweden)

    Tinkara Tinta

    possible changes in bacterial population dynamics and nutrient pathways following jellyfish blooms which have important implications for ecology of coastal waters.

  9. DISTRIBUTION OF ABO AND RH-D BLOOD GROUPS IN THE CACHAR DISTRICT OF BARAK VALLEY OF ASSAM: IMPLICATION FOR REGIONAL BLOOD TRANSFUSION SERVICE

    Directory of Open Access Journals (Sweden)

    Dharmakanta Kumbhakar

    2016-07-01

    Full Text Available BACKGROUND ABO and Rhesus (Rh-D blood group antigens are integrated parts of the red blood cell membranes. They are hereditary characters and are useful in population genetic studies, in resolving medico-legal issues and more importantly in compatibility test in blood transfusion and organ transplant practices. They show a wide geographical and racial variation. The knowledge of the distribution of ABO and Rh-D blood groups among different population is essential in health care and transfusion practices. AIMS AND OBJECTIVES To study the distribution of ABO and Rh-D blood groups amongst the population of Cachar district of Barak valley of Assam. MATERIALS AND METHODS We did a retrospective analysis of records of 1,60,500 blood samples grouped for ABO and Rh-D typing at Silchar Medical College and Hospital Blood Bank, Silchar, over a period of 10 years from 1st January 1999 to 31st December 2008. RESULTS AND OBSERVATIONS Out of total 1,60,500 blood samples grouped for ABO and Rh-D typing during the period in the centre, the distribution of phenotype A, B, AB and O were 24.80% (39,804, 32.00% (51,360, 5.60% (8,986 and 37.60% (60,350 respectively. The Rh-D positive phenotype was 95.40% (1, 53,117 and remaining 4.60% (7,383 was Rh-D negative. The frequency of Rh-D phenotypes in the various ABO blood groups was as - A Positive 23.70% (38,039, A Negative 1.10% (1,765, B Positive 30.80% (49,433, B Negative 1.20% (1,927, AB Positive 5.40% (8,665, AB Negative 0.20% (321, O Positive 35.50% (56,980 and O Negative 2.10% (3,370 respectively. DISCUSSION Silchar Medical College and Hospital Blood Bank receives blood samples for grouping of almost all population of Cachar district. Hence, the data revealed in the present study fairly reflects the prevalence of ABO and Rh-D groups distribution in the Cachar district in Barak valley of Assam. CONCLUSION The present study provide information on the status of ABO and Rh-D blood groups distribution of the region and

  10. Geochemistry of fine-grained clastic rocks in the Mesoproterozoic Kawabulake Group: implications for provenance and the tectonic model of the Eastern Tianshan, Xinjiang, NW China

    Science.gov (United States)

    Li, Deng-Feng; Chen, Hua-Yong; Zhang, Li; Fralick, Philip; Hollings, Pete; Mi, Mei; Lu, Wan-Jian; Han, Jin-Sheng; Wang, Cheng-Ming; Fang, Jing

    2016-02-01

    The Mesoproterozoic Kawabulake Group, which is unconformably overlain by the Lower Cambrian Huangshan Formation and conformably overlies the Mesoproterozoic Xingxingxia Group in the Eastern Tianshan area, NW China, is comprised mainly of siltstone, slate, sandstone and phyllite. New geochemical data for the clastic rocks from the Kawabulake Group were investigated to constrain the provenance and weathering history of the source rocks, in order to evaluate the tectonic evolution of the Eastern Tianshan area. Kawabulake Group rocks are compositionally similar to PAAS (average Post-Archean Australian Shale), indicating derivation from a felsic source that is characterized by depletion in some HFSEs such as Nb, Ta and Ti. The Chemical Index of Alteration (CIA) for the sandstone, siltstone and slate samples (CIA = 60 on average) suggests intensely weathered sources. Light REE-enrichment patterns ((La/Yb)CN = 4-20) coupled with negative Eu anomalies (Eu/Eu* between 0.44 and 0.89 with an average of 0.62) are similar to those of PAAS, consistent with cratonic sources. The major and trace element compositions imply a dominantly Precambrian felsic source region with a minor contribution from mafic materials. The Sr-Nd isotopic compositions and the ages of T DM2 (~3.4, 2.5-1.8, 1.2 and 1.0 Ga) are consistent with the evolutionary history of Kuluketage in the northern Tarim, suggesting that the Tarim Craton was the main source area for the Kawabulake Group.

  11. Geochemistry of fine-grained clastic rocks in the Mesoproterozoic Kawabulake Group: implications for provenance and the tectonic model of the Eastern Tianshan, Xinjiang, NW China

    Science.gov (United States)

    Li, Deng-Feng; Chen, Hua-Yong; Zhang, Li; Fralick, Philip; Hollings, Pete; Mi, Mei; Lu, Wan-Jian; Han, Jin-Sheng; Wang, Cheng-Ming; Fang, Jing

    2017-01-01

    The Mesoproterozoic Kawabulake Group, which is unconformably overlain by the Lower Cambrian Huangshan Formation and conformably overlies the Mesoproterozoic Xingxingxia Group in the Eastern Tianshan area, NW China, is comprised mainly of siltstone, slate, sandstone and phyllite. New geochemical data for the clastic rocks from the Kawabulake Group were investigated to constrain the provenance and weathering history of the source rocks, in order to evaluate the tectonic evolution of the Eastern Tianshan area. Kawabulake Group rocks are compositionally similar to PAAS (average Post-Archean Australian Shale), indicating derivation from a felsic source that is characterized by depletion in some HFSEs such as Nb, Ta and Ti. The Chemical Index of Alteration (CIA) for the sandstone, siltstone and slate samples (CIA = 60 on average) suggests intensely weathered sources. Light REE-enrichment patterns ((La/Yb)CN = 4-20) coupled with negative Eu anomalies (Eu/Eu* between 0.44 and 0.89 with an average of 0.62) are similar to those of PAAS, consistent with cratonic sources. The major and trace element compositions imply a dominantly Precambrian felsic source region with a minor contribution from mafic materials. The Sr-Nd isotopic compositions and the ages of T DM2 ( 3.4, 2.5-1.8, 1.2 and 1.0 Ga) are consistent with the evolutionary history of Kuluketage in the northern Tarim, suggesting that the Tarim Craton was the main source area for the Kawabulake Group.

  12. Peritonitis - spontaneous bacterial

    Science.gov (United States)

    Spontaneous bacterial peritonitis (SBP); Ascites - peritonitis; Cirrhosis - peritonitis ... who are on peritoneal dialysis for kidney failure. Peritonitis may have other causes . These include infection from ...

  13. Qualitative exploration of the benefits of group-based memory rehabilitation for people with neurological disabilities: implications for rehabilitation delivery and evaluation

    Science.gov (United States)

    Chouliara, Niki; Lincoln, Nadina B

    2016-01-01

    Objective To identify patient-perceived benefits of memory rehabilitation and draw transferrable lessons for the delivery and evaluation of similar interventions for people with neurological disabilities. Methods A qualitative study was conducted as part of a pragmatic randomised controlled trial comparing 2 memory rehabilitation approaches with a self-help control group. Postintervention interviews were conducted with 20 participants with a diagnosis of traumatic brain injury, multiple sclerosis or stroke. Data were analysed using a qualitative content analysis approach. Results Participants receiving memory rehabilitation reported that the sessions responded to previously unmet needs for information on brain injury and memory function and developed their insight along with a sense of self-efficacy and control over the management of their memory problems. Although they did not experience major improvements in their memory function per se, they reported that rehabilitation gave them the skills to effectively cope with the residual deficits. Respondents in the control groups did not report similar benefits. The opportunities for interaction offered by the group setting were greatly valued by all respondents. Mixed aetiology groups were received positively; however, marked differences in cognitive performance were frustrating for some participants. Conclusions The study highlighted important patient-perceived outcomes that should be considered by researchers and rehabilitation professionals when evaluating the effects of memory rehabilitation. The use of domain-specific outcome measures which reflect these areas is recommended. Qualitative changes in the use of memory aids may be achieved which cannot be captured by frequency indices alone. The benefits of the group-based rehabilitation approach were stressed by participants, suggesting that a combination of group and individual sessions might be a good practice. Trial registration number ISRCTN92582254; Results

  14. Bacterial endocarditis due to eikenella corrodens: A case report

    Directory of Open Access Journals (Sweden)

    Mahapatra A

    2003-01-01

    Full Text Available Of all the causes of bacterial endocarditis, HACEK group consisting of Haemophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella Kingae are rare causative agents. We report a case of bacterial endocarditis by E. corrodens, which is one of the members of the HACEK group.

  15. Zircon U-Pb Geochronology, Hf Isotopic Composition and Geological Implications of the Neoproterozoic Huashan Group in the Jingshan Area, Northern Yangtze Block, China

    Science.gov (United States)

    Yang, Z.; Yang, K.

    2015-12-01

    In the northern Yangtze Block, a clear angular unconformity between the Mesoproterozoic sequences (e.g. Dagushi Group) and the overlying Neoproterozoic strata (e.g. Huashan Group) marks the the Jinning orogeny. A combined study of Lu-Hf isotopes and U-Pb ages for detrital zircons from Huashan Group can provide information on the crustal evolution of sedimentary provenances and the timing of the Jinning orogeny. Detrital zircons from Huashan Group have two major U-Pb age populations of about 2.0Ga, 2.65Ga, and three subordinate age groups of about 0.82Ga, 2.5Ga, 2.9Ga with minor >3.0Ga ages. The youngest five analyses yield a weighted average age of 816±9Ma, which is consistent with that of interlayered basalt (824±9Ma, Deng et al., 2013) and roughly defines the minimum depositional age of Huashan Group. Detrital zircons of Huashan Group mostly have two stage Hf isotope model ages (TDM2) between 3.0 to 3.3Ga, indicating that the northern Yangtze Block experienced significant continental crustal growth during the Paleo- to Meso-archean. Similar U-Pb ages of detrital zircons have been obtained from Precambrian sedimentary rocks in the northern Yangtze Block from previous studies (Liu et al., 2008; Guo et al., 2014 and references therein). Recently, ca. 2.65Ga A-type granites had been reported from the Kongling and Huji area, which likely record the thermally stable lithosphere (Chen et al., 2013; Zhou et al., 2015). In combination with this study, it documents the widespread 2.6-2.7Ga magmatic rocks in the northern Yangtze Block. Zhao et al. (2013) demonstrated both the ca. 850Ma tonalite and trondhjemite of the Huangling igneous complex were formed in a continental arc setting. This suggests the Miaowan-Huashan oceanic basin proposed by Bader et al. (2013) has not been closed at ca. 850Ma. This evidence, together with the depositional age of the Huashan Group, indicates the Jinning orogeny took place at 850-820 Ma. [1] Bader et al., 2013 Tectonics [2] Deng et al

  16. Exploring the Knowledge, Attitudes, Beliefs, and Communication Preferences of the General Public regarding HPV: Findings from CDC Focus Group Research and Implications for Practice

    Science.gov (United States)

    Friedman, Allison L.; Shepeard, Hilda

    2007-01-01

    Genital human papillomavirus (HPV) infection is the most common sexually transmitted virus in the United States, causing genital warts, cervical cell abnormalities, and cervical cancer in women. To inform HPV education efforts, 35 focus groups were conducted with members of the general public, stratified by gender, race/ethnicity, and urban/rural…

  17. Supportive-Expressive Group Therapy for People Experiencing Collective Traumatic Crisis During the Genocide Commemoration Period in Rwanda: Impact and Implications

    Directory of Open Access Journals (Sweden)

    Darius Gishoma

    2014-08-01

    Full Text Available In Rwanda, the annual commemorations of the genocide are associated with an increase in the level of collective traumatic crises whereby many people participating in commemoration activities present various symptoms, including emotional distress and re-experiencing traumatic events of the 1994 genocide. These sudden crises normally last between 30 and 120 minutes and can affect hundreds of people at big commemoration events. They are accompanied by a degree of urgency that disturbs the whole assembly. This article briefly presents an overview of these crises and highlights the results of a study on the effects of a supportive-expression group intervention in the post-crisis period for people who experienced these collective traumatic crises. The study compares the therapeutic progress made by a group of people who participated in a supportive-expression group therapy program as compared to those who did not receive the intervention. The study suggests that the supportive group intervention can improve the overall psychological wellbeing of people who experienced collective traumatic crisis even though it was ineffective for some symptoms.

  18. Strong preferences of dopamine and l-dopa towards lipid head group: importance of lipid composition and implication for neurotransmitter metabolism

    DEFF Research Database (Denmark)

    Orlowski, A.; Grzybek, M.; Bunker, A.;

    2012-01-01

    a pronounced association with the lipid head groups, predominantly mediated through H-bonds. As a result the molecules are anchored to the interfacial region of the membrane. The strength of this interaction is dependent on lipid composition the presence of phosphatidylserine leads to an increase...

  19. The Missing Data Assumptions of the Nonequivalent Groups with Anchor Test (NEAT) Design and Their Implications for Test Equating. Research Report. ETS RR-09-16

    Science.gov (United States)

    Sinharay, Sandip; Holland, Paul W.

    2008-01-01

    The nonequivalent groups with anchor test (NEAT) design involves missing data that are missing by design. Three popular equating methods that can be used with a NEAT design are the poststratification equating method, the chain equipercentile equating method, and the item-response-theory observed-score-equating method. These three methods each…

  20. Zircon U-Pb Ages from an Ultra-High Temperature Metapelite, Rauer Group, East Antarctica: Implications for Overprints by Grenvillian and Pan-African Events

    Science.gov (United States)

    Wang, Yanbin; Tong, Laixi; Liu, Dunyi

    2007-01-01

    SHRIMP U-Pb dating of zircon from an ultra-high temperature (UHT, ~1000 °C) granulite-facies metapelite from the Rauer Group, Mather Peninsula, east Antarctica, has yielded evidence for two episodes of metamorphic zircon growth, at ~1.00 Ga and ~530 Ma, and two episodes of magmatism in the source region for the protolith sediment, at ~2.53 and ~2.65 Ga, were identified from the zircon cores. Successive zircon growth at ~1.00 Ga and ~530 Ma records a sequence of distinct, widely spaced high-temperature metamorphic and/or anatectic events related to Grenvillian and Pan-African orogenesis. This study presents the first robust geochronological evidence for the timing of UHT metamorphism of the Rauer Group, supporting arguments that the peak UHT metamorphic event occurred at ~1.00 Ga and was overprinted by a separate high-grade event at ~530 Ma. The new age data indicate that the UHT granulites of the Rauer Group experienced a complex, multi-stage tectonothermal history, which cannot simply be explained via a single Pan-African (~500 Ma) high-grade tectonic event. This is critical in understanding the role of the eastern Prydz Bay region during the assembly of the east Gondwana supercontinent, and the newly recognized inherited Archaean ages (~2.53 and ~2.65 Ga) suggest a close tectonic relationship between the Rauer Group and the adjacent Archaean of the Vestfold Hills

  1. A new turtle from the Upper Cretaceous Bauru Group of Brazil, updated phylogeny and implications for age of the Santo Anastácio Formation

    Science.gov (United States)

    Menegazzo, Mirian Costa; Bertini, Reinaldo José; Manzini, Flávio Fernando

    2015-03-01

    A new Podocnemidinura specimen from the Upper Cretaceous Bauru Group (Paraná Basin) of southeastern Brazil was described. The Bauru Group provided an important portrait of the Brazilian Mesozoic terrestrial biota, which boasts a vertebrate fauna formed from fishes, frogs, lacertilians, crocodyliforms, dinosaurs and mammals; records of palynomorphs; and invertebrate fauna consisted of gastropods, bivalves, ostracods and conchostracans. Nevertheless, the age of these continental deposits is not precisely estimated, which prevents global correlations, and its fauna is argued to be endemic. The new specimen described is the first turtle from the Santo Anastácio Formation, and its morphological comparison with other South American forms provided a significant advancement in the understanding of the age of this unit (Late Cretaceous). This study permitted a revision of the turtle taxa of the Bauru Group. As a result, some taxa were considered synonym, including the new Santo Anastácio form. The specimen is still unnamed due to the absence of skull characters that preclude its accurate positioning within the Bauru Group skull-based taxa. In addition, the phylogenetic affinities of this taxon were analyzed into Podocnemidinura clade.

  2. Contextual factors of the ICF as a tool for analysis of the implications of physical disability for a group of patients under Occupational Therapy care

    Directory of Open Access Journals (Sweden)

    Rosé Colom Toldrá

    2014-09-01

    Full Text Available This article analyzes the implications of the acquisition of physical disability on everyday life situations of persons under occupational therapy care using the International Classification of Functioning, Disability and Health – ICF, with emphasis on contextual factors. The study included 11 adults and elderly with physical impairments resulting from neurological disorders who were under Occupational Therapy care at the Center for Teaching and Research at the University of Sao Paulo from 2009 to 2010. It’s an exploratory qualitative research conducted through documentary study and semi-structured interview for the administration of the ICF components. Changes in body functions are diverse, both mental and related to movement, and when coupled with contextual factors may result in different levels and types of disabilities, preventing participation in life situations. The analysis of contextual factors helps to identify and relate personal and environmental aspects and their dynamic interaction reflects processes that may cause disability, establishing the ICF as a valuable guide for research and development of rehabilitation practices that consider the different aspects of the reality of a person’s life.

  3. Trypanosoma brucei gambiense group 1 is distinguished by a unique amino acid substitution in the HpHb receptor implicated in human serum resistance.

    Directory of Open Access Journals (Sweden)

    Rebecca E Symula

    Full Text Available Trypanosoma brucei rhodesiense (Tbr and T. b. gambiense (Tbg, causative agents of Human African Trypanosomiasis (sleeping sickness in Africa, have evolved alternative mechanisms of resisting the activity of trypanosome lytic factors (TLFs, components of innate immunity in human serum that protect against infection by other African trypanosomes. In Tbr, lytic activity is suppressed by the Tbr-specific serum-resistance associated (SRA protein. The mechanism in Tbg is less well understood but has been hypothesized to involve altered activity and expression of haptoglobin haemoglobin receptor (HpHbR. HpHbR has been shown to facilitate internalization of TLF-1 in T.b. brucei (Tbb, a member of the T. brucei species complex that is susceptible to human serum. By evaluating the genetic variability of HpHbR in a comprehensive geographical and taxonomic context, we show that a single substitution that replaces leucine with serine at position 210 is conserved in the most widespread form of Tbg (Tbg group 1 and not found in related taxa, which are either human serum susceptible (Tbb or known to resist lysis via an alternative mechanism (Tbr and Tbg group 2. We hypothesize that this single substitution contributes to reduced uptake of TLF and thus may play a key role in conferring serum resistance to Tbg group 1. In contrast, similarity in HpHbR sequence among isolates of Tbg group 2 and Tbb/Tbr provides further evidence that human serum resistance in Tbg group 2 is likely independent of HpHbR function.

  4. The Magnetosome Model: Insights into the Mechanisms of Bacterial Biomineralization

    Directory of Open Access Journals (Sweden)

    Lilah eRahn-Lee

    2013-11-01

    Full Text Available Though the most ready example of biomineralization is the calcium phosphate of vertebrate bones and teeth, many bacteria are capable of creating biominerals inside their cells. Because of the diversity of these organisms and the minerals they produce, their study may reveal aspects of the fundamental mechanisms of biomineralization in more complex organisms. The best-studied case of intracellular biomineralization in bacteria is the magnetosome, an organelle produced by a diverse group of aquatic bacteria that contains single-domain crystals of the iron oxide magnetite (Fe3O4 or the iron sulfide greigite (Fe3S4. Here, recent advances in our understanding of the mechanisms of bacterial magnetite biomineralization are discussed and used as a framework for understanding less-well studied examples, including the bacterial intracellular biomineralization of cadmium, selenium, silver, nickel, uranium, and calcium carbonate. Understanding the molecular mechanisms underlying the biological formation of these minerals will have important implications for technologies such as the fabrication of nanomaterials and the bioremediation of toxic compounds.

  5. U-Pb dating of zircon from the bed parallel anatectic granitic intrusion in the Baoban group in Hainan Island and the tectonic implication

    Institute of Scientific and Technical Information of China (English)

    DING; Shijiang; HU; Jianmin; SONG; Biao; CHEN; Mulun; XIE

    2005-01-01

    The petrological and geochemical features of the bed parallel granitic intrusion in the Pre-Cambrian Baoban group in Hainan Island attest to the anatexis origin of the granites. U-Pb dating analyses of zircons from the anatectic granite and the biotite two-feldspar gneiss in the Baoban group, using SHRIMP II in the Beijing Ion-probe Center, acquire 206Pb/238U ages of 368±3.5 Ma (of granite, 95% confidence level, MSDW=1.23) and 362.9±6.1 Ma (of gneiss, 95% confidence level, MSDW = 2.04) respectively. The two late Devonian ages indicate consistently a tectonic- thermal event experienced in Hainan Island, and are the first discovered record of the Devonian geological process in the district. This event possibly resulted from the deep thermal-dynamic process when the Gondwana continent began to break up in the Devonian period.

  6. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that ...... valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future....

  7. LA-ICP-MS U-Pb Zircon Geochronology of Basic Dikes within Maxianshan Rock Group in the Central Qilian Orogenic Belt and Its Tectonic Implications

    Institute of Scientific and Technical Information of China (English)

    He Shiping; Wang Hongliang; Chen Junlu; Xu Xueyi; Zhang Hongfei; Ren Guangming; Yu Jiyuan

    2007-01-01

    A large number of basic dikes, which indicate an important tectonic-magmatic event in the eastern part of the Central Qilian (祁连) orogenic belt, were found from Maxianshan (马衔山) rock group, Yongjing (永靖) county, Gansu (甘肃) Province, China. According to the research on the characteristics of geology and petrology, the basic dike swarms, widely intruded in Maxianshan rock group,are divided into two phases by the authors. U-Pb isotope of zircons from the basic dikes above two phases is separately determined by LA-ICP-MS in the Key Laboratory of Continental Dynamics of Northwest University, China and the causes of formation of the zircons are studied using CL images.The formation age of the earlier phase of metagabbro dikes is (441.1±1.4) Ma (corresponding to the early stage of Early Silurian), and the age of the main metamorphic period is (414.3±1.2) Ma (corresponding to the early stage of Early Devonian). The formation age of the later phase of diabase dike swarms is (434±1.0) Ma (corresponding to the late stage of Early Silurian). The cap- tured-zircons from diabase dike swarms saved some information of material interfusion by Maxianshan rock group (207pb/206Pb apparent ages are (2325±3)-(2573±6) Ma), and some zircons from diabase dike swarms also saved impacted information by tectonic thermal event during the late period of Caledonian movement (206pb/238U apparent ages are (400±2)-(429±2) Ma). By combining the results of the related studies, the basic dikes within Maxianshan rock group were considered to be formed in the transfer period, from subductional orogeny towards collisional orogeny, which represents geological records of NW-SE extension during regional NE-SW towards intense compression in the Central Qilian block.

  8. Interactions and potential implications of Plasmodium falciparum-hookworm coinfection in different age groups in south-central Cote d'Ivoire.

    Directory of Open Access Journals (Sweden)

    Aurélie A Righetti

    elucidate the mechanisms and consequences of coinfections, as this information could have important implications when implementing integrated control measures against malaria and helminthiases.

  9. Training implications of maximal forces on a computer-controlled and motor-driven leg press by age group, sex, footplate direction, and speed

    Science.gov (United States)

    Schulz, Brian W.; Hart-Hughes, Stephanie; Gordon, Mark T.; Bulat, Tatjana

    2017-01-01

    Strength training that overloads lengthening muscle fibers may result in greater strength gains with less effort and perceived exertion than conventional training modalities. This study evaluates a device capable of this overloading (a motor-driven and computer-controlled leg press) to develop recommendations for future training interventions. Unimpaired younger and older men and women (7/group, total n=28) performed three maximal-effort trials for both directions of footplate motion (IN and OUT) at three speed profiles (knee rotation speeds of 15, 25, and 35°/s) on a motor-driven and computer-controlled leg press. Normalized forces were tested for effects of age group, sex, direction of footplate motion, and knee rotation speed. Peak forces were 57% greater for younger and 20% greater for IN. Trends of greater IN relative to OUT forces (IN overloading) were present in women, but this was due to an inverse correlation between strength and IN overloading that was independent of age group and sex. Leg press strength training on a device that is capable of overloading lengthening muscle fibers is a promising new training method that appears to have the greatest potential benefits for the weakest participants. Training target profiles on the device tested and others similar to it should be set based on participant-specific maximums across the ROM in both IN and OUT directions at a speed in the middle of the range to be trained. PMID:22289381

  10. Subsurface Analysis of the Mesaverde Group on and near the Jicarilla Apache Indian Reservation, New Mexico-its implication on Sites of Oil and Gas Accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Ridgley, Jennie

    2001-08-21

    The purpose of the phase 2 Mesaverde study part of the Department of Energy funded project ''Analysis of oil-bearing Cretaceous Sandstone Hydrocarbon Reservoirs, exclusive of the Dakota Sandstone, on the Jicarilla Apache Indian Reservation, New Mexico'' was to define the facies of the oil-producing units within the subsurface units of the Mesaverde Group and integrate these results with outcrop studies that defined the depositional environments of these facies within a sequence stratigraphic context. The focus of this report will center on (1) integration of subsurface correlations with outcrop correlations of components of the Mesaverde, (2) application of the sequence stratigraphic model determined in the phase one study to these correlations, (3) determination of the facies distribution of the Mesaverde Group and their relationship to sites of oil and gas accumulation, (4) evaluation of the thermal maturity and potential source rocks for oil and gas in the Mesaverde Group, and (5) evaluation of the structural features on the Reservation as they may control sites of oil accumulation.

  11. Mean annual temperatures of mid-latitude regions derived from δ(2)H values of wood lignin methoxyl groups and its implications for paleoclimate studies.

    Science.gov (United States)

    Anhäuser, Tobias; Greule, Markus; Polag, Daniela; Bowen, Gabriel J; Keppler, Frank

    2017-01-01

    Tree-rings are widely used climate archives providing annual resolutions on centennial to millennial timescales. Stable isotope ratios of tree-rings have been applied to assist with the delineation of climate parameters such as temperature and precipitation. Here, we investigated stable hydrogen isotope ratios (expressed as δ(2)H values) of lignin methoxyl groups of wood from various tree species collected along a ~3500km north-south transect across Europe with mean annual temperatures (MAT) ranging from -4 to +17°C. We found a strong linear relationship between MATs and δ(2)H values of wood lignin methoxyl groups. We used this relationship to predict MATs from randomly collected wood samples and found general agreement between predicted and observed MATs for the mid-latitudes on a global scale. Our results are discussed in context of their paleoclimate relevance and suggest that δ(2)H values of lignin methoxyl groups might have the potential to reconstruct MATs when applied on mid-latitudinal tree-ring chronologies of the Late Holocene.

  12. Within-trait heterogeneity in age group differences in personality domains and facets: implications for the development and coherence of personality traits.

    Science.gov (United States)

    Mõttus, René; Realo, Anu; Allik, Jüri; Esko, Tõnu; Metspalu, Andres; Johnson, Wendy

    2015-01-01

    The study investigated differences in the Five-Factor Model (FFM) domains and facets across adulthood. The main questions were whether personality scales reflected coherent units of trait development and thereby coherent personality traits more generally. These questions were addressed by testing if the components of the trait scales (items for facet scales and facets for domain scales) showed consistent age group differences. For this, measurement invariance (MI) framework was used. In a sample of 2,711 Estonians who had completed the NEO Personality Inventory 3 (NEO PI-3), more than half of the facet scales and one domain scale did not meet the criterion for weak MI (factor loading equality) across 12 age groups spanning ages from 18 to 91 years. Furthermore, none of the facet and domain scales met the criterion for strong MI (intercept equality), suggesting that items of the same facets and facets of the same domains varied in age group differences. When items were residualized for their respective facets, 46% of them had significant (p facets were residualized for their domain scores, a majority had significant (p facets as embodied in the NEO PI-3 do not reflect aetiologically coherent traits.

  13. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate...... filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge...... about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria...

  14. Emerging bacterial pathogens: the past and beyond.

    Science.gov (United States)

    Vouga, M; Greub, G

    2016-01-01

    Since the 1950s, medical communities have been facing with emerging and reemerging infectious diseases, and emerging pathogens are now considered to be a major microbiologic public health threat. In this review, we focus on bacterial emerging diseases and explore factors involved in their emergence as well as future challenges. We identified 26 major emerging and reemerging infectious diseases of bacterial origin; most of them originated either from an animal and are considered to be zoonoses or from water sources. Major contributing factors in the emergence of these bacterial infections are: (1) development of new diagnostic tools, such as improvements in culture methods, development of molecular techniques and implementation of mass spectrometry in microbiology; (2) increase in human exposure to bacterial pathogens as a result of sociodemographic and environmental changes; and (3) emergence of more virulent bacterial strains and opportunistic infections, especially affecting immunocompromised populations. A precise definition of their implications in human disease is challenging and requires the comprehensive integration of microbiological, clinical and epidemiologic aspects as well as the use of experimental models. It is now urgent to allocate financial resources to gather international data to provide a better understanding of the clinical relevance of these waterborne and zoonotic emerging diseases.

  15. 领导风格分类对于团体辅导的启示%Implications of Different Leadership Styles for Group Counseling

    Institute of Scientific and Technical Information of China (English)

    虞悦; 古苑诗; 黄柔颖; 黄筑舲

    2014-01-01

    Leadership style is the explicit behavior, intention or feeling that the group members are aware of after a group leader presents himself. This article tries to arrange and describe different leadership styles and their potential relevance, relfecting the exist leadership style in a more speciifc and perfect way. In order to offer the reference about the practice of group counseling for the novice counselors, it also attempts to arrange and describe, in the axial of “warm/amiable-maintain boundaries/keep distance” and “actively/guide-respond/reaction”, the difference in the efifciency of different types of leadership style through two facets as relationship and work.%领导风格即在领导者呈现后能被成员所觉知到的外显行为、意图或感受。本文试图通过对不同类型的领导风格及其相关影响进行整理和描述,从而更具体与完整地反映出现有的领导风格类型,期待能以“关系”和“工作”两个面向作为分类的依据,在“温暖/亲和-保有界限/距离”以及“积极/引导-回应/反映”这两个轴面上整理描绘出不同类型领导风格的效能差异,作为未来新手咨询师在团体辅导实务上的参考。

  16. Provenance analysis of the Guaritas Group (RS conglomeratic sandstones: implications for the paleoclimate and paleogeography of the Eocambrian Central Camaquã sub-basin

    Directory of Open Access Journals (Sweden)

    Antonio Romalino Santos Fragoso-Cesar

    2013-06-01

    Full Text Available The Camaquã Supergroup, located in the central-south region of Rio Grande do Sul, Brazil, constitutes a rift-type post-orogenicsedimentary basin, whose deposition occurred in a continental environment between the Ediacaran and the Eocambrian.The upper succession of the Camaquã Supergroup is represented by the Guaritas Group, a unit formed by fluvial, eolian andalluvial fan deposits that keeps important records of the sedimentation right after the end of the neoproterozoic orogenesis thatgave rise to the Gondwana supercontinent. The objective of the present work was to apply sedimentary provenance analysis inconglomeratic arenites and conglomerates of the Guaritas Group, in order to explore the climatic and tectonic evolution historyof this unit. Based on the pebble compositional data, two main source areas were recognized for the deposits of this unit,a more distal one located to the north, related with a trunk river system parallel to the basin main axis, and a more proximalone located to the east, related to transversal fluvial systems and alluvial fans at the border of the basin. The comparison of theprovenance data with previous studies on facies and paleocurrents suggests that, during the entire evolution of the east borderof the basin, there was a same transversal fluvial system, whose catchment area suffered significative reductions due to thereactivation of the east border fault during the deposition of the Varzinha and Pedra Pintada Formations. The Serra do ApertadoFormation, the upper unit of Guaritas Group, shows a high correlation between the variation of quartzose and non quartzosepebbles composition, and it was attributed to a variation between more humid and more arid climatic conditions.

  17. The thrust contact between the Canastra and Vazante groups in the Southern Brasília Belt: structural evolution, white mica crystallinity and implications for the Brasiliano orogeny

    Directory of Open Access Journals (Sweden)

    Manuela de Oliveira Carvalho

    Full Text Available ABSTRACT: Two regional thrust-sheets of Neoproterozoic metasedimentary rocks occur in the Southern Brasília Belt, northwest Minas Gerais. The lower one comprises the Vazante Group, that is formed in the studied area, from base to top, by the Serra do Garrote (metapelites interlayered with carbonaceous phyllite, Serra do Poço Verde (beige to pink stromatolitic metadolomite with interlayered greenish slates, Morro do Calcário (gray stromatolitic metadolomite interlayered with gray slates and Serra da Lapa (phyllite with dolarenitic lenses interlayered with slates formations. The upper thrust sheet consists of the Canastra Group (Paracatu formation: laminated sericite phyllites and carbonaceous phyllites interlayered with quartzite. The Braziliano orogeny resulted in four phases of contractional deformation, associated with low-grade metamorphism. The first two (D1 and D2 are ductile, while the third and fourth ones (D3 and D4 are brittle-ductile. D1 developed a slaty S1 cleavage subparallel to the primary layering, with shallow to steep dips to NW. D2 developed a crenulation cleavage (S2 that dips moderately to NW and is associated with tight to isoclinal folds. D3 and D4 phases developed crenulations and open folds and kink bands. S3 dips steeply to NW, while S4 has moderate to steep dips to NE and SW. White mica crystallinity (Kübler index measurements in metapelites indicate that both the Canastra and Vazante groups reached anchizone/epizone conditions, and metamorphic discontinuities along thrusts indicate that the peak of metamorphism is pre or syn-thrusting.

  18. High frequency peritidal cycles of the upper Araras Group: Implications for disappearance of the neoproterozoic carbonate platform in southern Amazon Craton

    Science.gov (United States)

    Rudnitzki, Isaac Daniel; Romero, Guilherme Raffaeli; Hidalgo, Renata; Nogueira, Afonso Cesar Rodrigues

    2016-01-01

    The Araras Group is an extensive carbonate platform developed at the southeastern margin of the Amazon Craton during the Neoproterozoic. The Nobres Formation corresponds to the upper unit of the Neoproterozoic Araras Group. It is exposed in road cuts and quarries in the Northern Paraguay Belt, and is characterized by meter-scale shallowing upward cycles. Forty-four fourth-to fifth-order parasequence cycles are enclosed into three third order sequences/megacycles, unconformably overlain by siliciclastic deposits of the Alto Paraguay Group. The cycles are generally of peritidal type, limited by exposure surfaces composed of asymmetrical tidal flat/sabkha lithofacies in the basal Nobres Formation. They consist of fine dolostone, intraclastic dolostones with megaripples, stromatolites biostrome, sandy dolostone with enterolithic structures and silicified evaporite molds. Upsection, the cycles progressively become symmetrical, comprising arid tidal flat deposits with abundant stromatolite biostrome, fine-grained sandstone and rare evaporitic molds. The stacking patterns for hundreds of meters indicate continuous and recurrent generation of accommodation space, probably triggered by subsidence concomitant with relative sea-level changes. Palynomorphs found in the upper part of Nobres Formation comprehend spheroidal forms, such as Leiospharidia, rare filamentous and acanthomorphous acritarchs, mostly Tanarium correlated to the Ediacaran Complex Acantomorph Palynoflora of ˜580-570 Ma. Previous data of carbon isotopes and paleogeographic reconstructions, and also the presence of evaporites and storm-influenced deposits in the Araras Group, suggest a wet to tropical setting for Amazonia during the Mid-Ediacaran, which is incompatible with previous claims for Gaskiers-related glacial sedimentation in the region. During the final stages of evolution of the Araras carbonate platform, a progressive input of terrigenous has occurred in the peritidal setting likely due tectonic

  19. Integrated seismic analysis of the Chalk Group in eastern Denmark—Implications for estimates of maximum palaeo-burial in southwest Scandinavia

    DEFF Research Database (Denmark)

    Nielsen, Lars; Boldreel, Lars Ole; Hansen, Thomas Mejer;

    2011-01-01

    The origin of the topography of southwest Scandinavia is subject to discussion. Analysis of borehole seismic velocity has formed the basis for interpretation of several hundred metres of Neogene uplift in parts of Denmark.Here, refraction seismic data constrain a 7.5km long P-wave velocity model...... Group. The sonic velocities are consistent with the overall seismic layering, although they show additional fine-scale layering. Integration of gamma and sonic log with porosity data shows that seismic velocity is sensitive to clay content. In intervals near boundaries of the refraction model, moderate...

  20. Effect of verapamil on ischemia and ventricular arrhythmias after an acute myocardial infarction: prognostic implications. The Danish Verapamil Infarction Trial II Study Group

    DEFF Research Database (Denmark)

    Vaage-Nilsen, M; Rasmussen, Verner; Hansen, J F

    1991-01-01

    : In the placebo group the prevalence and incidence of many ventricular ectopic beats (VEBs), i.e., more than 10 VEBs/h, increased significantly during the first years after infarction; this was not the case in the verapamil patients group. The mean HR was significantly reduced by verapamil treatment after 1 month...... for 24-48 h at 1 week, i.e., before randomization to long-term treatment with placebo or verapamil, and after 1 month and about 1 year of study treatment. Ischemia: 18% of the patients had transient ST-segment deviation before randomization; 24% of the placebo- and 8% of the verapamil-treated patients (p...... = 0.04) showed ischemia after 1 month; and after 1 year, the figures were 26 and 4%, respectively (p = 0.02). The 18-month major event rate, i.e., first reinfarction or death, in patients with ischemia before randomization were 40 and 23.8% in patients without ischemia (p = 0.06). Arrhythmias...

  1. Low-molecular-weight heparin biosimilars: potential implications for clinical practice. Australian Low-Molecular-Weight Heparin Biosimilar Working Group (ALBW).

    Science.gov (United States)

    Nandurkar, H; Chong, B; Salem, H; Gallus, A; Ferro, V; McKinnon, R

    2014-05-01

    A working group of clinicians and scientists was formed to review the clinical considerations for use of low-molecular-weight heparin (LMWH) biosimilars. LMWH are biological molecules of significant complexity; the full complexity of chemical structure is still to be elucidated. LMWH biosimilars are products that are biologically similar to their reference product and rely on clinical data from a reference product to establish safety and efficacy. The complex nature of LMWH molecules means that it is uncertain whether a LMWH biosimilar is chemically identical to its reference product; this introduces the possibility of differences in activity and immunogenicity. The challenge for regulators and clinicians is to evaluate the level of evidence required to demonstrate that a LMWH is sufficiently similar to the reference product. The consensus opinion of the working group is that prior to clinical use a LMWH biosimilar should have proven efficacy and safety, similar to the reference product with prospective studies, which should be confirmed with a proactive post-marketing pharmacovigilance programme.

  2. Distribution of archaeal and bacterial glycerol dialkyl glycerol tetraethers in tropical sediments from Guadeloupe (French West Indies): implications for application of the MBT/CBT and TEX86 proxies

    Science.gov (United States)

    Huguet, A.; Belmahdi, I.; Fosse, C.; Grossi, V.; Derenne, S.

    2012-04-01

    Glycerol dialkyl glycerol tetraethers (GDGTs) are lipids of high molecular weight present in membranes of Archaea and some bacteria. Archaeal membranes are composed predominantly of isoprenoid GDGTs, with acyclic or ring-containg biphytanyl chains. The amount of isoprenoid GDGTs with cyclopentyl moieties was shown to increase with water temperature and variations in surface water temperature can be determined via the TEX86 proxy. Recently, another type of GDGTs, with branched instead of isoprenoid alkyl chains, has been discovered in peat and was observed to occur ubiquitously in soils and in aquatic environments. Branched GDGTs were suggested to be produced in soils by still unknown bacteria. The degree of methylation of branched GDGTs, expressed in the MBT, was shown to depend on air temperature and to a lesser extent on soil pH, whereas the relative abundance of cyclopentyl rings of branched GDGTs, expressed in the CBT, was related to soil pH. The MBT/CBT proxies are increasingly used as paleoclimate proxies. The aim of this study was to investigate the distribution of GDGTs in tropical sediments from Guadeloupe (French West Indies). Surficial sediment samples were collected in four coastal water ponds: two located in Grande-Terre and two in a smaller island named La Désirade, 10 km east from Grande-Terre. GDGTs either present as core lipids (CLs; presumed of fossil origin) or derived from intact polar lipids (IPLs; markers for living cells) were analysed. A large part of archaeal GDGTs was present as IPLs (40-50% of total extractable archaeal GDGTs) in all sites. The proportion of IPL GDGTs of bacterial origin with respect to the total pool (CLs +IPLs) was 25-30% in the sediments from La Désirade and ~ 50% in the upper sediment layers from Grande-Terre. Interestingly, the distribution of archaeal and bacterial GDGTs differed between the four sites, as shown by the higher values of the TEX86 and MBT in sediments from La Désirade (TEX86~0.80; MBT~0

  3. Marine mesocosm bacterial colonisation of volcanic ash

    Science.gov (United States)

    Witt, Verena; Cimarelli, Corrado; Ayris, Paul; Kueppers, Ulrich; Erpenbeck, Dirk; Dingwell, Donald; Woerheide, Gert

    2015-04-01

    Volcanic eruptions regularly eject large quantities of ash particles into the atmosphere, which can be deposited via fallout into oceanic environments. Such fallout has the potential to alter pH, light and nutrient availability at local scales. Shallow-water coral reef ecosystems - "rainforests of the sea" - are highly sensitive to disturbances, such as ocean acidification, sedimentation and eutrophication. Therefore, wind-delivered volcanic ash may lead to burial and mortality of such reefs. Coral reef ecosystem resilience may depend on pioneer bacterial colonisation of the ash layer, supporting subsequent establishment of the micro- and ultimately the macro-community. However, which bacteria are involved in pioneer colonisation remain unknown. We hypothesize that physico-chemical properties (i.e., morphology, mineralogy) of the ash may dictate bacterial colonisation. The effect of substrate properties on bacterial colonisation was tested by exposing five substrates: i) quartz sand ii) crystalline ash (Sakurajima, Japan) iii) volcanic glass iv) carbonate reef sand and v) calcite sand of similar grain size, in controlled marine coral reef aquaria under low light conditions for six months. Bacterial communities were screened every month by Automated Ribosomal Intergenic Spacer Analysis of the 16S-23S rRNA Internal Transcribed Spacer region. Multivariate statistics revealed discrete groupings of bacterial communities on substrates of volcanic origin (ash and glass) and reef origin (three sands). Analysis of Similarity supported significantly different communities associated with all substrates (p=0.0001), only quartz did not differ from both carbonate and calcite sands. The ash substrate exhibited the most diverse bacterial community with the most substrate-specific bacterial operational taxonomic units. Our findings suggest that bacterial diversity and community composition during colonisation of volcanic ash in a coral reef-like environment is controlled by the

  4. Molecular Analysis of Bacterial Microbiota on Brazilian Currency Note Surfaces.

    Science.gov (United States)

    Pereira da Fonseca, Tairacan Augusto; Pessôa, Rodrigo; Sanabani, Sabri Saeed

    2015-10-22

    Currency notes have been implicated as a vehicle for transmitting community-acquired bacterial infections. However, the overall diversity of the bacterial population residing on banknotes is still unknown in Brazil. In this study, we aimed to investigate the overall bacterial population from 150 different Brazilian Rial (R$) notes in circulation using a culture-independent Illumina massively parallel sequencing approach of the 16S rRNA genes. Samples were randomly collected from three different street markets or "feiras" in the metropolitan region of São Paulo. Taxonomical composition revealed the abundance of Proteobacteria phyla, followed by Firmicutes and Streptophyta, with a total of 1193 bacterial families and 3310 bacterial genera. Most of these bacterial genera are of human, animal, and environmental origins. Also, our analysis revealed the presence of some potential pathogenic bacterial genera including Salmonella, Staphylococcus, and Klebsiella. The results demonstrate that there is a tremendous diversity of bacterial contamination on currency notes, including organisms known to be opportunistic pathogens. One of the factors that may contribute to the richness of bacterial diversity in currency notes is personal hygiene. Thus, our results underscore the need to increase public awareness of the importance of personal hygiene of money handlers who also handle food.

  5. Molecular Analysis of Bacterial Microbiota on Brazilian Currency Note Surfaces

    Directory of Open Access Journals (Sweden)

    Tairacan Augusto Pereira da Fonseca

    2015-10-01

    Full Text Available Currency notes have been implicated as a vehicle for transmitting community-acquired bacterial infections. However, the overall diversity of the bacterial population residing on banknotes is still unknown in Brazil. In this study, we aimed to investigate the overall bacterial population from 150 different Brazilian Rial (R$ notes in circulation using a culture-independent Illumina massively parallel sequencing approach of the 16S rRNA genes. Samples were randomly collected from three different street markets or “feiras” in the metropolitan region of São Paulo. Taxonomical composition revealed the abundance of Proteobacteria phyla, followed by Firmicutes and Streptophyta, with a total of 1193 bacterial families and 3310 bacterial genera. Most of these bacterial genera are of human, animal, and environmental origins. Also, our analysis revealed the presence of some potential pathogenic bacterial genera including Salmonella, Staphylococcus, and Klebsiella. The results demonstrate that there is a tremendous diversity of bacterial contamination on currency notes, including organisms known to be opportunistic pathogens. One of the factors that may contribute to the richness of bacterial diversity in currency notes is personal hygiene. Thus, our results underscore the need to increase public awareness of the importance of personal hygiene of money handlers who also handle food.

  6. Calpains promote neutrophil recruitment and bacterial clearance in an acute bacterial peritonitis model.

    Science.gov (United States)

    Kumar, Vijay; Everingham, Stephanie; Hall, Christine; Greer, Peter A; Craig, Andrew W B

    2014-03-01

    Activation of the innate immune system is critical for clearance of bacterial pathogens to limit systemic infections and host tissue damage. Here, we report a key role for calpain proteases in bacterial clearance in mice with acute peritonitis. Using transgenic mice expressing Cre recombinase primarily in innate immune cells (fes-Cre), we generated conditional capns1 knockout mice. Consistent with capns1 being essential for stability and function of the ubiquitous calpains (calpain-1, calpain-2), peritoneal cells from these mice had reduced levels of calpain-2/capns1, and reduced proteolysis of their substrate selenoprotein K. Using an acute bacterial peritonitis model, we observed impaired bacterial killing within the peritoneum and development of bacteremia in calpain knockout mice. These defects correlated with significant reductions in IL-1α release, neutrophil recruitment, and generation of reactive oxygen species in calpain knockout mice with acute bacterial peritonitis. Peritoneal macrophages from calpain knockout mice infected with enterobacteria ex vivo, were competent in phagocytosis of bacteria, but showed impaired clearance of intracellular bacteria compared with control macrophages. Together, these results implicate calpains as key mediators of effective innate immune responses to acute bacterial infections, to prevent systemic dissemination of bacteria that can lead to sepsis.

  7. Geochemistry and oxygen isotope composition of main-group pallasites and olivine-rich clasts in mesosiderites: Implications for the "Great Dunite Shortage" and HED-mesosiderite connection

    Science.gov (United States)

    Greenwood, Richard C.; Barrat, Jean-Alix; Scott, Edward R. D.; Haack, Henning; Buchanan, Paul C.; Franchi, Ian A.; Yamaguchi, Akira; Johnson, Diane; Bevan, Alex W. R.; Burbine, Thomas H.

    2015-11-01

    Evidence from iron meteorites indicates that a large number of differentiated planetesimals formed early in Solar System history. These bodies should have had well-developed olivine-rich mantles and consequentially such materials ought to be abundant both as asteroids and meteorites, which they are not. To investigate this "Great Dunite Shortage" we have undertaken a geochemical and oxygen isotope study of main-group pallasites and dunitic rocks from mesosiderites. Oxygen isotope analysis of 24 main-group pallasites (103 replicates) yielded a mean Δ17O value of -0.187 ± 0.016‰ (2σ), which is fully resolved from the HED Δ17O value of -0.246 ± 0.014 (2σ) obtained in our earlier study and demonstrates that both groups represent distinct populations and were derived from separate parent bodies. Our results show no evidence for Δ17O bimodality within the main-group pallasites, as suggested by a number of previous studies. Olivine-rich materials from the Vaca Muerta, Mount Padbury and Lamont mesosiderites, and from two related dunites (NWA 2968 and NWA 3329), have Δ17O values within error of the mesosiderite average. This indicates that these olivine-rich materials are co-genetic with other mesosiderite clasts and are not fragments from an isotopically distinct pallasite-like impactor. Despite its extreme lithologic diversity the mesosiderite parent body was essentially homogeneous with respect to Δ17O, a feature best explained by an early phase of large-scale melting (magma ocean), followed by prolonged igneous differentiation. Based on the results of magma ocean modeling studies, we infer that Mg-rich olivines in mesosiderites formed as cumulates in high-level chambers and do not represent samples of the underlying mantle. By analogy, recently documented Mg-rich olivines in howardites may have a similar origin. Although the Dawn mission did not detect mesosiderite-like material on Vesta, evidence linking the mesosiderites and HEDs includes: (i) their nearly

  8. Chemical Abundances and Kinematics in Globular Clusters and Local Group Dwarf Galaxies and Their Implications for Formation Theories of the Galactic Halo

    CERN Document Server

    Geisler, Doug; Smith, Verne V; Casetti-Dinescu, Dana I

    2007-01-01

    We review Galactic halo formation theories and supporting evidence, in particular kinematics and detailed chemical abundances of stars in some relevant globular clusters as well as Local Group dwarf galaxies. Outer halo red HB clusters tend to have large eccentricities and inhabit the area populated by dwarf spheroidal stars, favoring an extraGalactic origin. Old globulars show the full range of eccentricities, while younger ones seem to have preferentially high eccentricities, again hinting at their extraGalactic origin. We compare detailed abundances of a variety of elements between the halo and all dwarf galaxies studied to date, including both dwarf spheroidals and irregulars. The salient feature is that halo abundances are essentially unique. In particular, the general alpha vs. [Fe/H] pattern of 12 of the 13 galaxies studied are similar to each other and very different from the Milky Way. Sagittarius appears to be the only possible exception. It appears very unlikely that a significant fraction of the m...

  9. Implications for HIV/AIDS of laws affecting men who have sex with men in Romania. ACCEPT (The Bucharest Acceptance Group).

    Science.gov (United States)

    Macovei, M; Coman, A

    1999-01-01

    In this article, the authors discuss the predicament, in Romanian society, of one group that is especially vulnerable to HIV infection and AIDS: men who have sex with men. Such men are driven to secrecy, and discouraged from disclosing themselves even to obtain the help and information they need, because Romanian law prohibits homosexual overtures, denies legal recognition to gay and lesbian organisations, often imposes strong disincentives in the way of those seeking diagnostic tests for HIV or for venereal disease, and still penalizes same sex relations themselves in many circumstances. Social and administrative circumstances in Romania have also aggravated such men's vulnerability. Drawing especially on the United Nations' International Guidelines on HIV/AIDS and Human Rights, the authors offer several recommendations for reform.

  10. Platinum-group Elements Geochemistry of the Yangliuping Magmatic Ni-Cu-PGE Sulfide Deposit:Implications of Its Genetic Link with the Extrusive Basalts

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jianbin; CAO Zhimin; SONG Xieyan; AN Wei; LIU Ji

    2004-01-01

    Primitive mantle-normalized Platinum-group elements (PGE) concentration patterns for the Zhengziyanwo intrusion and Dashibao Formation basalts are of positive slope, similar to most of the world-class magmatic Ni-Cu-PGE sulfide deposits. Characters of this intrusion and its related ores and Dashibao Formation basalts are their negative Pt-anomaly and high concentration of Rh relative to Pt and Pd, facts being interpreted to be the results of crystallization and fractionation of Pt-alloys and spinel phase-free crystallization history for the magma, respectively. PGE parameters of the Dashibao Formation basalts are consistent with the general trend of those found for the Zhengziyanwo intrusion, and this might infer a genetic link between them.

  11. Detrital zircon U-Pb and Hf isotopic data from the Liuling Group in the South Qinling belt: Provenance and tectonic implications

    Science.gov (United States)

    Liao, Xiao-ying; Wang, Ya-wei; Liu, Liang; Wang, Chao; Santosh, M.

    2017-02-01

    The Liuling Group is exposed in the Northern part of the South Qinling orogenic belt. LA-ICP-MS U-Pb analysis of detrital zircons from the meta-sandstones in this Group yields ages ranging between 400 Ma and 3200 Ma, with three prominent age clusters at 500-400 Ma, 850-700 Ma and 1000-900 Ma. A few older zircon populations with U-Pb ages of 1750-1450 Ma, 2000 Ma and 2600-2400 Ma are also present. Age data integrated with cathodoluminescence, trace element data and εHf(t) values of zircon grains show that the Liuling sediments have a complex source. Source rocks mainly include Early Neoproterozoic and Early Paleozoic granitoids, together with minor ultra-high pressure/high pressure (HP-UHP) metamorphic rocks, and paragneiss in the North Qinling belt, and Middle-Late Neoproterozoic magmatic rocks in the South Qinling belt. The dominant population of detrital zircon grains with ages between 500 Ma and 400 Ma show the characteristics of both magmatic and metamorphic zircons. They show three age clusters at 497 Ma, 451 Ma, and ca. 420 Ma and show marked correlation with the three stages of Palaeozoic magmatism, as well as with the peak and retrograde HP-UHP metamorphic stages in the North Qinling belt. This correlation demonstrates that these Early Palaeozoic granitoids and HP-UHP metamorphic rocks in the North Qinling belt were already exhumed to the surface, underwent erosion prior to Middle Devonian time and were then deposited in an extensional basin. Based on the results from detrital zircon U-Pb dating, combined with geochemical data and the regional geology, the deposition of Liuling sediments is inferred to have occurred in a post-orogenic extensional basin, rather than a subduction-related fore-arc basin or a foreland basin formed during or after continental collision.

  12. Cytosolic Access of Intracellular Bacterial Pathogens: The Shigella Paradigm.

    Science.gov (United States)

    Mellouk, Nora; Enninga, Jost

    2016-01-01

    Shigella is a Gram-negative bacterial pathogen, which causes bacillary dysentery in humans. A crucial step of Shigella infection is its invasion of epithelial cells. Using a type III secretion system, Shigella injects several bacterial effectors ultimately leading to bacterial internalization within a vacuole. Then, Shigella escapes rapidly from the vacuole, it replicates within the cytosol and spreads from cell-to-cell. The molecular mechanism of vacuolar rupture used by Shigella has been studied in some detail during the recent years and new paradigms are emerging about the underlying molecular events. For decades, bacterial effector proteins were portrayed as main actors inducing vacuolar rupture. This includes the effector/translocators IpaB and IpaC. More recently, this has been challenged and an implication of the host cell in the process of vacuolar rupture has been put forward. This includes the bacterial subversion of host trafficking regulators, such as the Rab GTPase Rab11. The involvement of the host in determining bacterial vacuolar integrity has also been found for other bacterial pathogens, particularly for Salmonella. Here, we will discuss our current view of host factor and pathogen effector implications during Shigella vacuolar rupture and the steps leading to it.

  13. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    defense. Antibiotics exhibit a rather limited effect on biofilms. Furthermore, antibiotics have an ‘inherent obsolescence’ because they select for development of resistance. Bacterial infections with origin in bacterial biofilms have become a serious threat in developed countries. Pseudomonas aeruginosa...... that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation......, resistance and QS inhibition as future antimicrobial targets, in particular those that would work to minimize selection pressures for the development of resistant bacteria....

  14. Paleogeographic and tectonic implications of the first paleomagnetic results from the Middle Late Cambrian Mesón Group: NW Argentina

    Science.gov (United States)

    Spagnuolo, Cecilia M.; Rapalini, Augusto E.; Astini, Ricardo A.

    2008-02-01

    The first paleomagnetic data from autochthonous Cambrian rocks in NW Argentina is reported to constrain the apparent polar wander path (APWP) of Gondwana during the Early Paleozoic. The paleomagnetic pole (Lat 4.5°S; Long 359.0°E; dp = 5.5; dm = 8.8; n = 26) was obtained from the red to purple sandstones of the Campanario Formation. These rocks present a characteristic remanence carried by fine-grained hematite. The pole indicates that during the Late Cambrian, rocks now exposed in the Eastern Cordillera of NW Argentina were deposited at relatively low latitudes (≈26°S), consistent with intense chemical alteration during wet and warm climates, as indicated from petrography of apparent first-cycle quarzites of the Mesón Group. However, the pole position is anomalous with respect to the most accepted apparent polar wander paths for Gondwana, suggesting that the study area (22°50'S, 65°00'W) underwent clockwise rotation of 38° ± 8°, likely related to the Cenozoic central Andes rotation pattern characteristic of the region.

  15. Character, relative age and implications of fractures and other mesoscopic structures associated with detachment folds: an example from the Lisburne Group of the Northeastern Brooks Range, Alaska.

    Energy Technology Data Exchange (ETDEWEB)

    Hanks, C.L. [Alaska Univ., Fairbanks, AK (United States). Geophysical Inst.; Wallace, W.K.; Atkinson, P.K.; Brinton, J. [Alaska Univ., Fairbanks, AK (United States). Dept. of Geology and Geophysics; Alaska Univ., Fairbanks, AK (United States). Geophysical Inst.; Bui, T.; Jensen, J. [Texas A and M Univ., College Station, TX (United States). Dept. of Petroleum Engineering; Lorenz, J. [Sandia National Laboratory, Albuquerque, NM (United States)

    2004-06-01

    Hydrocarbon exploration can benefit enormously from a proper knowledge of the history and unique character of a fold-and-thrust belt. The study of fractures and other mesoscopic structures can help explain folding mechanisms. The northeastern Brooks Range of Alaska represents a fairly simple fold-and-thrust belt in which the history of fracture development can be studied. Deformed Lisburne Group carbonates preserve the character and sequence of fractures and suggest a variety of mechanisms for fracture formation before, during, and after folding. The earliest fractures were probably formed in the foreland basin and later incorporated into the thrust belt, then thrusted and folded. Later, carbonates that were previously lying flat were incorporated into the fold-and-thrust belt where they were deformed mainly by a detachment fold, as a result of flexural slip and homogeneous flattening. Early fractures such as these were commonly overprinted or destroyed by ductile strain as later homogeneous flattening allowed additional shortening. These were in turn overprinted by late extension fractures that formed during flexural slip in the last phases of folding or after folding due to unroofing of the orogenic wedge. This study thus highlights how multiple generations of mesoscopic structures may be related to the kinematics of a specific fold-and-thrust belt. 45 refs., 1 tab., 16 figs.

  16. Geochemistry of fine-grained sediments of the upper Cretaceous to Paleogene Gosau Group (Austria, Slovakia: Implications for paleoenvironmental and provenance studies

    Directory of Open Access Journals (Sweden)

    Gerald Hofer

    2013-07-01

    Full Text Available Bulk rock geochemistry of 169 fine-grained sediment samples of the upper Cretaceous to Paleogene Gosau Group (Northern Calcareous Alps, Austria and Slovakia from borehole and outcrop localities was performed to separate non-marine and marine deposits. Geochemical characteristics of different Gosau depositional systems, basins and sediment provenance using major-, trace-, and rare earth elements were also investigated. Geochemical proxies such as boron concentrations were tested for seeking the possibilities of paleosalinity indicators. Due to the fact that several pelagic sections are represented by extremely low boron contents, B/Al* ratios are recognized as more robust and differentiate reliably between marine (mean: 160 ± 34 and non-marine (mean: 133 ± 33 samples. Using statistical factor analysis, hemipelagic to pelagic samples from the Gießhübl Syncline and Slovakian equivalents can be differentiated from marginal-marine to non-marine samples from the Grünbach and Glinzendorf Syncline related to terrigenous (SiO2, Al2O3, K2O, Th, Rb, Zr and others and pelagic indicative elements (CaO, Sr, TOT/C and B/Al*. A clear indication for ophiolitic provenance is traced by high amounts of chromium and nickel. Only non-marine successions of the Glinzendorf Syncline show higher Cr and Ni concentrations (up to 250 and 400 ppm, respectively and enriched Cr/V and Y/Ni ratios trending to an ultramafic source.

  17. The pH-dependent release of platinum group elements (PGEs) from gasoline and diesel fuel catalysts: Implication for weathering in soils.

    Science.gov (United States)

    Suchá, Veronika; Mihaljevič, Martin; Ettler, Vojtěch; Strnad, Ladislav

    2016-04-15

    Powdered samples of new and old gasoline catalysts (Pt, Pd, Rh) and new and old diesel (Pt) catalysts were subjected to a pH-static leaching procedure (pH 2-9) coupled with thermodynamic modeling using PHREEQC-3 to verify the release and mobility of PGEs (platinum group elements). PGEs were released under acidic conditions, mostly exhibiting L-shaped leaching patterns: diesel old: 5.47, 0.005, 0.02; diesel new: 68.5, 0.23, 0.11; gasoline old: 0.1, 11.8, 4.79; gasoline new 2.6, 25.2, 35.9 in mg kg(-1) for Pt, Pd and Rh, respectively. Only the new diesel catalyst had a strikingly different leaching pattern with elevated concentrations at pH 4, probably influenced by the dissolution of the catalyst carrier and washcoat. The pH-static experiment coupled with thermodynamic modeling was found to be an effective instrument for understanding the leaching behavior of PGEs under various environmental conditions, and indicated that charged Pt and Rh species may be adsorbed on the negatively charged surface of kaolinite or Mn oxides in the soil system, whereas uncharged Pd and Rh species may remain mobile in soil solutions.

  18. The petrochemistry of the auriferous, volcanosedimentary Riacho dos Machados Group, Central-eastern Brazil: geotectonic implications for shear-hosted gold mineralization

    Science.gov (United States)

    da Fonseca, E.; Lobato, L. M.; Baars, F. J.

    1997-12-01

    The Ouro Fino Gold Deposit at the Riacho dos Machados Mine is located in the Araçuaí Fold Belt at the eastern margin of the São Francisco Craton. The gold is shear zone-hosted and associated principally with a sulphide-bearing, quartzmuscovite schist, derived from the hydrothermal alteration of pelitic and quartzofeldspathic schists of the Riacho dos Machados Group (RMG). Along the shear zones, mineral associations typical of the amphibolite facies are progressively altered to assemblages typical of the greenschist facies. It has become evident from the studies that the process of segregation and concentration of chemical elements and minerals is the very process of mineralization, involving the concentration of Au. The RMG comprises ultramafic, mafic and acid metavolcanic rocks intercalated in a sequence of metapelites. The metapelites have textures and geochemistry compatible with greywackes. The dacitic and mafic/ultramafic rocks are of calc-alkaline and tholeiitic subalkaline association, respectively. The RMG probably formed within a continental volcanic arc. The thrust faults that establish the regional architecture, and which host the Riacho dos Machados gold mineralization, are related to a continental collision of unknown age between the precursor to the São Francisco Craton and the Guanambi-Correntina Block.

  19. Diversity Takes Shape: Understanding the Mechanistic and Adaptive Basis of Bacterial Morphology

    Science.gov (United States)

    2016-01-01

    The modern age of metagenomics has delivered unprecedented volumes of data describing the genetic and metabolic diversity of bacterial communities, but it has failed to provide information about coincident cellular morphologies. Much like metabolic and biosynthetic capabilities, morphology comprises a critical component of bacterial fitness, molded by natural selection into the many elaborate shapes observed across the bacterial domain. In this essay, we discuss the diversity of bacterial morphology and its implications for understanding both the mechanistic and the adaptive basis of morphogenesis. We consider how best to leverage genomic data and recent experimental developments in order to advance our understanding of bacterial shape and its functional importance. PMID:27695035

  20. Bacterial intermediate filaments

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Cabeen, M.; Jacobs-Wagner, C.

    2009-01-01

    Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin...

  1. Bacterial Wound Culture

    Science.gov (United States)

    ... Home Visit Global Sites Search Help? Bacterial Wound Culture Share this page: Was this page helpful? Also known as: Aerobic Wound Culture; Anaerobic Wound Culture Formal name: Culture, wound Related ...

  2. Bacterial surface adaptation

    Science.gov (United States)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  3. Bacterial Meningitis in Infants

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-04-01

    Full Text Available A retrospective study of 80 infantile patients (ages 30-365 days; 47 male, 33 female with culture-proven bacterial meningitis seen over a 16 year period (1986-2001 is reported from Taiwan.

  4. Micro-structural and compositional variations of hydrothermal epidote-group minerals from a peralkaline granite, Corupá Pluton, Graciosa Province, South Brazil, and their petrological implications

    Directory of Open Access Journals (Sweden)

    Silvio R.F. Vlach

    2012-06-01

    Full Text Available Epidote-group minerals, together with albite, quartz, fluorite, Al-poor and Fe-rich phyllosilicates, zircon, and minor oxides and sulphides, are typical hydrothermal phases in peralkaline alkali-feldspar granites from the Corupá Pluton, Graciosa Province, South Brazil. The epidote-group minerals occur as single crystals and as aggregates filling in rock interstices and miarolitic cavities. They display complex recurrent zoning patterns with an internal zone of ferriallanite-(Ce, followed by allanite-(Ce, then epidote-ferriepidote, and an external zone with allanite-(Ce, with sharp limits, as shown in BSE and X-ray images. REE patterns show decreasing fractionation degrees of LREE over HREE from ferriallanite to epidote. The most external allanite is enriched in MREE. LA-ICP-MS data indicate that ferriallanite is enriched (>10-fold in Ti, Sr and Ga, and depleted in Mg, Rb, Th and Zr relative to the host granite. Allanite has lower Ga and Mn and higher Zr, Nb and U contents as compared to ferriallanite, while epidote is enriched in Sr, U and depleted in Pb, Zr, Hf, Ti and Ga. The formation of these minerals is related to the variable concentrations of HFSE, Ca, Al, Fe and F in fluids remaining from magmatic crystallization, in an oxidizing environment, close to the HM buffer. L-MREE were in part released by the alteration of chevkinite, their main primary repository in the host rocks.Minerais do grupo do epidoto, com albita, quartzo, fluorita, filossilicatos pobres em Al e ricos em Fe, zircão e quantidades menores de óxidos e sulfetos são fases hidrotermais típicas em álcali-feldpato granitos peralcalinos do Pluton Corupá, Província Graciosa, Sul do Brasil. Os minerais do grupo do epidoto ocorrem como cristais individuais ou agregados que preenchem interstícios e cavidades miarolíticas na rocha. Mostram zonamento complexo, recorrente, descrito por uma zona interna de ferriallanita-(Ce, seguida por allanita-(Ce, epidoto-ferriepidoto e uma

  5. Structural Analysis of Histo-Blood Group Antigen Binding Specificity in a Norovirus GII.4 Epidemic Variant: Implications for Epochal Evolution

    Energy Technology Data Exchange (ETDEWEB)

    Shanker, Sreejesh; Choi, Jae-Mun; Sankaran, Banumathi; Atmar, Robert L.; Estes, Mary K.; Prasad, B.V. Venkataram (Baylor); (LBNL)

    2012-03-23

    Susceptibility to norovirus (NoV), a major pathogen of epidemic gastroenteritis, is associated with histo-blood group antigens (HBGAs), which are also cell attachment factors for this virus. GII.4 NoV strains are predominantly associated with worldwide NoV epidemics with a periodic emergence of new variants. The sequence variations in the surface-exposed P domain of the capsid protein resulting in differential HBGA binding patterns and antigenicity are suggested to drive GII.4 epochal evolution. To understand how temporal sequence variations affect the P domain structure and contribute to epochal evolution, we determined the P domain structure of a 2004 variant with ABH and secretor Lewis HBGAs and compared it with the previously determined structure of a 1996 variant. We show that temporal sequence variations do not affect the binding of monofucosyl ABH HBGAs but that they can modulate the binding strength of difucosyl Lewis HBGAs and thus could contribute to epochal evolution by the potentiated targeting of new variants to Lewis-positive, secretor-positive individuals. The temporal variations also result in significant differences in the electrostatic landscapes, likely reflecting antigenic variations. The proximity of some of these changes to the HBGA binding sites suggests the possibility of a coordinated interplay between antigenicity and HBGA binding in epochal evolution. From the observation that the regions involved in the formation of the HBGA binding sites can be conformationally flexible, we suggest a plausible mechanism for how norovirus disassociates from salivary mucin-linked HBGA before reassociating with HBGAs linked to intestinal epithelial cells during its passage through the gastrointestinal tract.

  6. Prevalence of BRCA1 mutations among 403 women with triple-negative breast cancer: implications for genetic screening selection criteria: a Hellenic Cooperative Oncology Group Study.

    Science.gov (United States)

    Fostira, Florentia; Tsitlaidou, Marianthi; Papadimitriou, Christos; Pertesi, Maroulio; Timotheadou, Eleni; Stavropoulou, Alexandra V; Glentis, Stavros; Bournakis, Evangelos; Bobos, Mattheos; Pectasides, Dimitrios; Papakostas, Pavlos; Pentheroudakis, George; Gogas, Helen; Skarlos, Pantelis; Samantas, Epaminontas; Bafaloukos, Dimitrios; Kosmidis, Paris A; Koutras, Angelos; Yannoukakos, Drakoulis; Konstantopoulou, Irene; Fountzilas, George

    2012-07-01

    In spite the close association of the triple-negative breast cancer immunophenotype with hereditary breast cancers and the BRCA1 pathway, there is a lack of population studies that determine the frequency of BRCA1 mutations among triple-negative breast cancer patients. To address this, we have screened a large sample of 403 women diagnosed with triple-negative invasive breast cancer, independently of their age or family history, for germline BRCA1 mutations. Median age at diagnosis was 50 years (range 20-83). The overall prevalence of triple-negative cases among the initial patient group with invasive breast cancer was 8%. BRCA1 was screened by direct DNA sequencing in all patients, including all exons where a mutation was previously found in the Greek population (exons 5, 11, 12, 16, 20, 21, 22, 23, 24-77% of the BRCA1 coding region), including diagnostic PCRs to detect the three Greek founder large genomic rearrangements. Sixty-five deleterious BRCA1 mutations were identified among the 403 triple-negative breast cancer patients (16%). Median age of onset for mutation carriers was 39 years. Among a total of 106 women with early-onset triple-negative breast cancer (<40 years), 38 (36%) had a BRCA1 mutation, while 27% of women with triple-negative breast cancer diagnosed before 50 years (56/208) had a BRCA1 mutation. A mutation was found in 48% (50/105) of the triple-negative breast cancer patients with family history of breast or ovarian cancer. It is noteworthy, however, that of the 65 carriers, 15 (23%) had no reported family history of related cancers. All but one of the carriers had grade III tumors (98%). These results indicate that women with early-onset triple-negative breast cancer, and ideally all triple-negative breast cancer patients, are candidates for BRCA1 genetic testing even in the absence of a family history of breast or ovarian cancer.

  7. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    2013-01-01

    Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing....... These extracellular proteases are activated in complex cascades involving auto-processing and proteolytic maturation. Thus, proteolysis has been adopted by bacterial pathogens at multiple levels to ensure the success of the pathogen in contact with the human host....

  8. Bacterial degradation of monocyclic aromatic amines

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Arora

    2015-08-01

    Full Text Available Aromatic amines are an important group of industrial chemicals, which are widely used for manufacturing of dyes, pesticides, drugs, pigments, and other industrial products. These compounds have been considered highly toxic to human beings due to their carcinogenic nature. Three groups of aromatic amines have been recognized: monocyclic, polycyclic and heterocyclic aromatic amines. Bacterial degradation of several monocyclic aromatic compounds has been studied in a variety of bacteria, which utilizes monocyclic aromatic amines as their sole source of carbon and energy. Several degradation pathways have been proposed and the related enzymes and genes have also been characterized. Many reviews have been reviewed toxicity of monocyclic aromatic amines; however, there is lack of review on biodegradation of monocyclic aromatic amines. The aim of this review is to summarize bacterial degradation of monocyclic aromatic amines. This review will increase our current understanding of biochemical and molecular basis of bacterial degradation of monocyclic aromatic amines.

  9. [Diagnosis of bacterial vaginosis].

    Science.gov (United States)

    Djukić, Slobodanka; Ćirković, Ivana; Arsić, Biljana; Garalejić, Eliana

    2013-01-01

    Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2-producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent's scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up-to-date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short-term and long-term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  10. Geochemical constraints on komatiite volcanism from Sargur Group Nagamangala greenstone belt, western Dharwar craton, southern India: Implications for Mesoarchean mantle evolution and continental growth

    Directory of Open Access Journals (Sweden)

    Tushipokla

    2013-05-01

    Full Text Available We present field, petrographic, major and trace element data for komatiites and komatiite basalts from Sargur Group Nagamangala greenstone belt, western Dharwar craton. Field evidences such as crude pillow structure indicate their eruption in a marine environment whilst spinifex texture reveals their komatiite nature. Petrographic data suggest that the primary mineralogy has been completely altered during post-magmatic processes associated with metamorphism corresponding to greenschist to lower amphibolite facies conditions. The studied komatiites contain serpentine, talc, tremolite, actinolite and chlorite whilst tremolite, actinolite with minor plagioclase in komatiitic basalts. Based on the published Sm-Nd whole rock isochron ages of adjoining Banasandra komatiites (northern extension of Nagamangala belt and further northwest in Nuggihalli belt and Kalyadi belt we speculate ca. 3.2–3.15 Ga for komatiite eruption in Nagamangala belt. Trace element characteristics particularly HFSE and REE patterns suggest that most of the primary geochemical characteristics are preserved with minor influence of post-magmatic alteration and/or contamination. About 1/3 of studied komatiites show Al-depletion whilst remaining komatiites and komatiite basalts are Al-undepleted. Several samples despite high MgO, (Gd/YbN ratios show low CaO/Al2O3 ratios. Such anomalous values could be related to removal of CaO from komatiites during fluid-driven hydrothermal alteration, thus lowering CaO/Al2O3 ratios. The elemental characteristics of Al-depleted komatiites such as higher (Gd/YbN (>1.0, CaO/Al2O3 (>1.0, Al2O3/TiO2 (18 together with higher HREE, Y, Zr suggest their derivation from shallower upper mantle without garnet involvement in residue. The observed chemical characteristics (CaO/Al2O3, Al2O3/TiO2, MgO, Ni, Cr, Nb, Zr, Y, Hf, and REE indicate derivation of the komatiite and komatiite basalt magmas from heterogeneous mantle (depleted to primitive mantle at

  11. 蔗糖凝胶治疗细菌性阴道病的多中心、随机、双盲、平行对照Ⅲ期临床试验%Sucrose gel for treatment of bacterial vaginosis:a randomized, double-blind, multi-center, parallel-group, phase Ⅲ clinical trial

    Institute of Scientific and Technical Information of China (English)

    肖冰冰; 张岱; 陈锐; 史惠蓉; 辛晓燕; 王惠兰; 庞义存; 朱赛楠; 姚晨

    2015-01-01

    目的:通过多中心、随机、双盲、平行对照的临床研究,进一步评价蔗糖凝胶治疗细菌性阴道病的有效性及安全性. 方法:选择5个研究中心的533例细菌性阴道病患者作为研究对象,依据随机表按对照组与试验组为2:3比例随机入组,甲硝唑凝胶5. 0 g组(对照组)214例,蔗糖凝胶5. 0 g组(实验组)319例,两组均采取每日早晚各一次阴道上药,连用5 d的疗程进行治疗. 分别于治疗第7~10天、第21~30天进行疗效观察及安全性评价.结果:治疗第7~10天,甲硝唑凝胶组和蔗糖凝胶组的临床综合疗效治愈率分别为70. 53%和80. 83%,阴道分泌物涂片Nugent积分痊愈率分别为71. 50%和81. 15%,差异均有统计学意义(P0. 05). 结论:蔗糖凝胶治疗细菌性阴道病的临床综合疗效近期(治疗第7~10天)及恢复阴道菌群方面明显优于甲硝唑凝胶,远期治愈率(治疗第21~30天)与甲硝唑凝胶相当,可成为治疗细菌性阴道病的新策略.%Objective:To evaluate the cure effectiveness and safety of sucrose gel in the treatment of bacterial vaginosis through a multi-center, randomized, double-blind, parallel controlled clinical study. Methods:A clinical research method of multi-center, randomly double-blind, and dose group parallel comparison was adopted. In the study, 533 patients with bacterial vaginosis were randomly divided into two groups, which included 214 cases in the control group (5. 0 g metronidazole gel) and 319 cases in the trial group (5. 0 g sucrose gel ). The patients were treated with different medication according to the group where they were. All the cases in these two groups were treated with drugs vaginally twice in a day, morning and evening separately, for 5 days. The curative effect and safety evaluation were assessed from 7 to 10 days and 21 to 30 days after treatment respectively. Results: The efficacy of the comprehensive clinical treatment showed that the cure rate of metronidazole gel group

  12. Super-heavy pyrite (δ34Spyr > δ34SCAS) in the terminal Proterozoic Nama Group, Southern Namibia: Implications for atmospheric oxygen and seawater sulfate at the dawn of animal life

    Science.gov (United States)

    Ries, J. B.; Fike, D. A.; Pratt, L.; Lyons, T. W.; Grotzinger, J. P.

    2009-12-01

    Sulfur isotope analysis (δ34S) of well-preserved carbonates spanning a ca. 10 Myr interval of the terminal Proterozoic Nama Group in Namibia, southwestern Africa, reveals that pyrite is consistently enriched in 34S relative to coeval seawater sulfate as preserved in carbonate associated sulfate (CAS). This observation is not consistent with the current paradigm for interpreting the geologic record of sulfur isotopes, which assumes that pyrite δ34S (δ34Spyr) will be equal to or less than co-occurring CAS δ34S (δ34SCAS) due to the kinetic isotope effect of bacterial sulfate reduction (BSR) that favors the lighter isotope of sulfur (32S) during sulfur-oxygen bond-breakage. Although the precise mechanism of pyrite enrichment is debatable, our combined observations of extremely enriched pyrite, low concentrations of CAS and pyrite, and high frequency fluctuations in δ34SCAS and δ34Spyr throughout the Nama Group carbonates point to very low concentrations of sulfate in portions of the terminal Proterozoic ocean. The additional occurrence of 34S-enriched pyrite in contemporaneous terminal Proterozoic sections from Poland and Canada reveal that low seawater sulfate may have been widespread in the oceans at this time. However, the absence of such extremely 34S-enriched pyrites from well-preserved, coeval carbonate sections in Oman suggests that such conditions were not globally uniform. Low, geographically varied concentrations of marine sulfate in terminal Proterozoic time are consistent with elevated and geographically varied concentrations of reactive, non-pyritized iron in marine shales recently reported for this interval, suggesting that high dissolved Fe(II)/low O2 conditions persisted in a range of marine facies as late as 543 Ma - tens of millions of years after the origin of animals yet prior to their major diversification in Early Cambrian time.

  13. Bacterial microbiome of lungs in COPD.

    Science.gov (United States)

    Sze, Marc A; Hogg, James C; Sin, Don D

    2014-01-01

    Chronic obstructive pulmonary disease (COPD) is currently the third leading cause of death in the world. Although smoking is the main risk factor for this disease, only a minority of smokers develop COPD. Why this happens is largely unknown. Recent discoveries by the human microbiome project have shed new light on the importance and richness of the bacterial microbiota at different body sites in human beings. The microbiota plays a particularly important role in the development and functional integrity of the immune system. Shifts or perturbations in the microbiota can lead to disease. COPD is in part mediated by dysregulated immune responses to cigarette smoke and other environmental insults. Although traditionally the lung has been viewed as a sterile organ, by using highly sensitive genomic techniques, recent reports have identified diverse bacterial communities in the human lung that may change in COPD. This review summarizes the current knowledge concerning the lung microbiota in COPD and its potential implications for pathogenesis of the disease.

  14. Spectrum of bacterial colonization associated with urothelial cells from patients with chronic lower urinary tract symptoms.

    Science.gov (United States)

    Khasriya, Rajvinder; Sathiananthamoorthy, Sanchutha; Ismail, Salim; Kelsey, Michael; Wilson, Mike; Rohn, Jennifer L; Malone-Lee, James

    2013-07-01

    Chronic lower urinary tract symptoms (LUTS), such as urgency and incontinence, are common, especially among the elderly, but their etiology is often obscure. Recent studies of acute urinary tract infections implicated invasion by Escherichia coli into the cytoplasm of urothelial cells, with persistence of long-term bacterial reservoirs, but the role of infection in chronic LUTS is unknown. We conducted a large prospective study with eligible patients with LUTS and controls over a 3-year period, comparing routine urine cultures of planktonic bacteria with cultures of shed urothelial cells concentrated in centrifuged urinary sediments. This comparison revealed large numbers of bacteria undetected by routine cultures. Next, we typed the bacterial species cultured from patient and control sediments under both aerobic and anaerobic conditions, and we found that the two groups had complex but significantly distinct profiles of bacteria associated with their shed bladder epithelial cells. Strikingly, E. coli, the organism most responsible for acute urinary tract infections, was not the only or even the main offending pathogen in this more-chronic condition. Antibiotic protection assays with shed patient cells and in vitro infection studies using patient-derived strains in cell culture suggested that LUTS-associated bacteria are within or extremely closely associated with shed epithelial cells, which explains how routine cultures might fail to detect them. These data have strong implications for the need to rethink our common diagnoses and treatments of chronic urinary tract symptoms.

  15. Competition and facilitation between the marine nitrogen-fixing cyanobacterium Cyanothece and its associated bacterial community.

    Science.gov (United States)

    Brauer, Verena S; Stomp, Maayke; Bouvier, Thierry; Fouilland, Eric; Leboulanger, Christophe; Confurius-Guns, Veronique; Weissing, Franz J; Stal, LucasJ; Huisman, Jef

    2014-01-01

    N2-fixing cyanobacteria represent a major source of new nitrogen and carbon for marine microbial communities, but little is known about their ecological interactions with associated microbiota. In this study we investigated the interactions between the unicellular N2-fixing cyanobacterium Cyanothece sp. Miami BG043511 and its associated free-living chemotrophic bacteria at different concentrations of nitrate and dissolved organic carbon and different temperatures. High temperature strongly stimulated the growth of Cyanothece, but had less effect on the growth and community composition of the chemotrophic bacteria. Conversely, nitrate and carbon addition did not significantly increase the abundance of Cyanothece, but strongly affected the abundance and species composition of the associated chemotrophic bacteria. In nitrate-free medium the associated bacterial community was co-dominated by the putative diazotroph Mesorhizobium and the putative aerobic anoxygenic phototroph Erythrobacter and after addition of organic carbon also by the Flavobacterium Muricauda. Addition of nitrate shifted the composition toward co-dominance by Erythrobacter and the Gammaproteobacterium Marinobacter. Our results indicate that Cyanothece modified the species composition of its associated bacteria through a combination of competition and facilitation. Furthermore, within the bacterial community, niche differentiation appeared to play an important role, contributing to the coexistence of a variety of different functional groups. An important implication of these findings is that changes in nitrogen and carbon availability due to, e.g., eutrophication and climate change are likely to have a major impact on the species composition of the bacterial community associated with N2-fixing cyanobacteria.

  16. Cerebrospinal fluid ferritin in children with viral and bacterial meningitis.

    Science.gov (United States)

    Rezaei, M; Mamishi, S; Mahmoudi, S; Pourakbari, B; Khotaei, G; Daneshjou, K; Hashemi, N

    2013-01-01

    Despite the fact that the prognosis of bacterial meningitis has been improved by the influence of antibiotics, this disease is still one of the significant causes of morbidity and mortality in children. Rapid differentiation between bacterial and aseptic meningitis, and the need for immediate antibiotic treatment in the former, is crucial in the prognosis of these patients. Ferritin is one of the most sensitive biochemical markers investigated in cerebrospinal fluid (CSF) for the early diagnosis of bacterial meningitis. The present study aims to evaluate the diagnostic capability of CSF ferritin in differentiating bacterial and viral meningitis in the paediatric setting. A cross-sectional study was carried out in the referral Children's Medical Center Hospital, Tehran, during 2008 and 2009. According to the inclusion criteria, CSF samples from 42 patients with suspected meningitis were obtained and divided into two meningitis groups, bacterial (n = 18) and viral (n = 24). Ferritin and other routine determinants (i.e., leucocytes, protein and glucose) were compared between the two groups. Ferritin concentration in the bacterial meningitis group was 106.39 +/- 86.96 ng/dL, which was considerably higher than in the viral meningitis group (10.17 +/- 14.09, P meningitis group and showed a positive correlation with CSF ferritin. In conclusion, this study suggests that CSF ferritin concentration is an accurate test for the early differentiation of bacterial and aseptic meningitis; however, further investigation on a larger cohort of patients is required to confirm this finding.

  17. Meningitis bacteriana Bacterial meningitis

    Directory of Open Access Journals (Sweden)

    Ana Teresa Alvarado Guevara

    2006-03-01

    causales son virales lo cual conlleva a las diferentes sub-clasificaciones. También en ciertos casos puede ser ocasionada por hongos, bacterias atípicas, micobacterias y parásitos.In Costa Rica the bacterial meningitis had turn into a high-priority subject in which to monitoring epidemiologist. It had been talked about in the last months, to dice an increase in the attention is published of this subject, due to this phenomenon it becomes necessary to make a revision of topic. Meningitis is an inflammation of leptomeninges and colonization of the subarachnoid cerebrospinal fluid (LCR due to different agents, which produces meningeal symptoms (ex. migraine, neck rigidity, and photophobia and pleocytosis in LCR. De pending on the variables to take into account is possible to group it in different classifications, taking into account the time of evolution are possible to be divided in acute or chronic, to first with few hours or days of beginning of the symptoms, whereas the chronicle also presents a silence course but of the disease of approximately 4 weeks of instauration. There is a difference according to its etiologic agent; they can be infectious and non-infectious. Examples of common non-infectious causes include medications (ex, nonsteroidal anti-inflammatory drugs, and antibiotics and carcinomatosis. A classification exists as well according to the causal agent. The acute bacterial meningitis remarks a bacterial origin of the syndrome, which characterizes by the by an acute onset of meningeal symptoms and neutrophilic pleocytosis. Each one of the bacteriological agents, parasitic or fungus finishes by characterizing the different presentations of the clinical features (ex, meningocóccica meningitis, Cryptococcus meningitis. Finally, there is also the aseptic meningitis, denominated in this form because it’s nonpyogenic cellular response caused by many types of agents. The patients show an acute beginning of symptoms, fever and lymphocytic pleocytosis. After

  18. Bacterial vaginosis in pregnant adolescents: proinflammatory cytokine and bacterial sialidase profile. Cross-sectional study

    Directory of Open Access Journals (Sweden)

    Carolina Sanitá Tafner Ferreira

    Full Text Available ABSTRACT CONTEXT AND OBJECTIVE: Bacterial vaginosis occurs frequently in pregnancy and increases susceptibility to sexually transmitted infections (STI. Considering that adolescents are disproportionally affected by STI, the aim of this study was to evaluate the cervicovaginal levels of interleukin (IL-1 beta, IL-6, IL-8 and bacterial sialidase in pregnant adolescents with bacterial vaginosis. DESIGN AND SETTING: Cross-sectional study at mother and child referral units in Belém, Pará, Brazil. METHODS: Vaginal samples from 168 pregnant adolescents enrolled were tested for trichomoniasis and candidiasis. Their vaginal microbiota was classified according to the Nugent criteria (1991 as normal, intermediate or bacterial vaginosis. Cervical infection due to Chlamydia trachomatisand Neisseria gonorrhoeae was also assessed. Cytokine and sialidase levels were measured, respectively, using enzyme-linked immunosorbent assays and MUAN conversion in cervicovaginal lavages. Forty-eight adolescents (28.6% were excluded because they tested positive for some of the infections investigated. The remaining 120 adolescents were grouped according to vaginal flora type: normal (n = 68 or bacterial vaginosis (n = 52. Their cytokine and sialidase levels were compared between the groups using the Mann-Whitney test (P < 0.05. RESULTS: The pregnant adolescents with bacterial vaginosis had higher levels of IL-1 beta, IL-6 and IL-8 (P < 0.05. Sialidase was solely detected in 35 adolescents (67.2% with bacterial vaginosis. CONCLUSIONS: Not only IL-1 beta and sialidase levels, but also IL-6 and IL-8 levels are higher in pregnant adolescents with bacterial vaginosis, thus indicating that this condition elicits a more pronounced inflammatory response in this population, which potentially increases vulnerability to STI acquisition.

  19. Gut flora and bacterial translocation in chronic liver disease

    Institute of Scientific and Technical Information of China (English)

    John Almeida; Sumedha Galhenage; Jennifer Yu; Jelica Kurtovic; Stephen M Riordan

    2006-01-01

    Increasing evidence suggests that derangement of gut flora is of substantial clinical relevance to patients with cirrhosis. Intestinal bacterial overgrowth and increased bacterial translocation of gut flora from the intestinal lumen, in particular, predispose to an increased potential for bacterial infection in this group. Recent studies suggest that, in addition to their role in the pathogenesis of overt infective episodes and the clinical consequences of sepsis, gut flora contributes to the pro-inflammatory state of cirrhosis even in the absence of overt infection.Furthermore, manipulation of gut flora to augment the intestinal content of lactic acid-type bacteria at the expense of other gut flora species with more pathogenic potential may favourably influence liver function in cirrhotic patients. Here we review current concepts of the various inter-relationships between gut flora, bacterial translocation, bacterial infection, pro-inflammatory cytokine production and liver function in this group.

  20. Urban greenness influences airborne bacterial community composition.

    Science.gov (United States)

    Mhuireach, Gwynne; Johnson, Bart R; Altrichter, Adam E; Ladau, Joshua; Meadow, James F; Pollard, Katherine S; Green, Jessica L

    2016-11-15

    Urban green space provides health benefits for city dwellers, and new evidence suggests that microorganisms associated with soil and vegetation could play a role. While airborne microorganisms are ubiquitous in urban areas, the influence of nearby vegetation on airborne microbial communities remains poorly understood. We examined airborne microbial communities in parks and parking lots in Eugene, Oregon, using high-throughput sequencing of the bacterial 16S rRNA gene on the Illumina MiSeq platform to identify bacterial taxa, and GIS to measure vegetation cover in buffer zones of different diameters. Our goal was to explore variation among highly vegetated (parks) versus non-vegetated (parking lots) urban environments. A secondary objective was to evaluate passive versus active collection methods for outdoor airborne microbial sampling. Airborne bacterial communities from five parks were different from those of five parking lots (p=0.023), although alpha diversity was similar. Direct gradient analysis showed that the proportion of vegetated area within a 50m radius of the sampling station explained 15% of the variation in bacterial community composition. A number of key taxa, including several Acidobacteriaceae were substantially more abundant in parks, while parking lots had higher relative abundance of Acetobacteraceae. Parks had greater beta diversity than parking lots, i.e. individual parks were characterized by unique bacterial signatures, whereas parking lot communities tended to be similar to each other. Although parks and parking lots were selected to form pairs of nearby sites, spatial proximity did not appear to affect compositional similarity. Our results also showed that passive and active collection methods gave comparable results, indicating the "settling dish" method is effective for outdoor airborne sampling. This work sets a foundation for understanding how urban vegetation may impact microbial communities, with potential implications for designing

  1. Bacterial communities of two ubiquitous Great Barrier Reef corals reveals both site- and species-specificity of common bacterial associates.

    Directory of Open Access Journals (Sweden)

    E Charlotte E Kvennefors

    Full Text Available BACKGROUND: Coral-associated bacteria are increasingly considered to be important in coral health, and altered bacterial community structures have been linked to both coral disease and bleaching. Despite this, assessments of bacterial communities on corals rarely apply sufficient replication to adequately describe the natural variability. Replicated data such as these are crucial in determining potential roles of bacteria on coral. METHODOLOGY/PRINCIPAL FINDINGS: Denaturing Gradient Gel Electrophoresis (DGGE of the V3 region of the 16S ribosomal DNA was used in a highly replicated approach to analyse bacterial communities on both healthy and diseased corals. Although site-specific variations in the bacterial communities of healthy corals were present, host species-specific bacterial associates within a distinct cluster of gamma-proteobacteria could be identified, which are potentially linked to coral health. Corals affected by "White Syndrome" (WS underwent pronounced changes in their bacterial communities in comparison to healthy colonies. However, the community structure and bacterial ribotypes identified in diseased corals did not support the previously suggested theory of a bacterial pathogen as the causative agent of the syndrome. CONCLUSIONS/SIGNIFICANCE: This is the first study to employ large numbers of replicated samples to assess the bacterial communities of healthy and diseased corals, and the first culture-independent assessment of bacterial communities on WS affected Acroporid corals on the GBR. Results indicate that a minimum of 6 replicate samples are required in order to draw inferences on species, spatial or health-related changes in community composition, as a set of clearly distinct bacterial community profiles exist in healthy corals. Coral bacterial communities may be both site and species specific. Furthermore, a cluster of gamma-proteobacterial ribotypes may represent a group of specific common coral and marine

  2. Periodontal diseases as bacterial infection

    Directory of Open Access Journals (Sweden)

    A. Bascones Martínez

    Full Text Available The periodontal disease is conformed by a group of illnesses affecting the gums and dental support structures. They are caused by certain bacteria found in the bacterial plaque. These bacteria are essential to the onset of illness; however, there are predisposing factors in both the host and the microorganisms that will have an effect on the pathogenesis of the illness. Periodontopathogenic bacterial microbiota is needed, but by itself, it is not enough to cause the illness, requiring the presence of a susceptible host. These diseases have been classified as gingivitis, when limited to the gums, and periodontitis, when they spread to deeper tissues. Classification of periodontal disease has varied over the years.The one used in this work was approved at the International Workshop for a Classification of Periodontal Diseases and Conditions, held in 1999. This study is an overview of the different periodontal disease syndromes. Later, the systematic use of antibiotic treatment consisting of amoxicillin, amoxicillinclavulanic acid, and metronidazole as first line coadjuvant treatment of these illnesses will be reviewed.

  3. Complement-mediated opsonization of invasive group A Streptococcus pyogenes strain AP53 is regulated by the bacterial two-component cluster of virulence responder/sensor (CovRS) system.

    Science.gov (United States)

    Agrahari, Garima; Liang, Zhong; Mayfield, Jeffrey A; Balsara, Rashna D; Ploplis, Victoria A; Castellino, Francis J

    2013-09-20

    Group A Streptococcus pyogenes (GAS) strain AP53 is a primary isolate from a patient with necrotizing fasciitis. These AP53 cells contain an inactivating mutation in the sensor component of the cluster of virulence (cov) responder (R)/sensor (S) two-component gene regulatory system (covRS), which enhances the virulence of the primary strain, AP53/covR(+)S(-). However, specific mechanisms by which the covRS system regulates the survival of GAS in humans are incomplete. Here, we show a key role for covRS in the regulation of opsonophagocytosis of AP53 by human neutrophils. AP53/covR(+)S(-) cells displayed potent binding of host complement inhibitors of C3 convertase, viz. Factor H (FH) and C4-binding protein (C4BP), which concomitantly led to minimal C3b deposition on AP53 cells, further showing that these plasma protein inhibitors are active on GAS cells. This resulted in weak killing of the bacteria by human neutrophils and a corresponding high death rate of mice after injection of these cells. After targeted allelic alteration of covS(-) to wild-type covS (covS(+)), a dramatic loss of FH and C4BP binding to the AP53/covR(+)S(+) cells was observed. This resulted in elevated C3b deposition on AP53/covR(+)S(+) cells, a high level of opsonophagocytosis by human neutrophils, and a very low death rate of mice infected with AP53/covR(+)S(+). We show that covRS is a critical transcriptional regulator of genes directing AP53 killing by neutrophils and regulates the levels of the receptors for FH and C4BP, which we identify as the products of the fba and enn genes, respectively.

  4. Agentes bacterianos enteropatogênicos em suínos de diferentes faixas etárias e perfil de resistência a antimicrobianos de cepas de Escherichia coli e Salmonella spp Enteropathogenic bacterial agents in pigs of different age groups and profile of resistance in strains of Escherichia coli and Salmonella spp. to antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Álvaro Menin

    2008-09-01

    Full Text Available As enterites infecciosas bacterianas provocam severas perdas para a indústria suína em todo o mundo. Os objetivos deste trabalho foram determinar os agentes bacterianos, associados com a ocorrência de diarréia em suínos, em diferentes faixas etárias, no Estado de Santa Catarina, Brasil, e verificar o perfil de resistência das cepas de Escherichia coli e Salmonella spp, frente aos principais antimicrobianos utilizados em granjas de suínos. Os principais gêneros/espécies bacterianos diagnosticados foram Escherichia coli, Clostridium spp, Salmonella spp Brachyspira hyodysenteriae, Brachyspira pilosicoli e Lawsonia intracellularis. Os fatores de virulência de E. coli mais prevalentes na fase de maternidade foram F5 / (K99 20%, F6 / (987P 16,3%, F42 6,8% e F41 5,7%, já nas fases de creche e terminação, predominaram cepas com fimbrias F4 (K88 11,2% e 5,4%, respectivamente. Para E. coli os maiores índices de resistência foram encontrados para oxitetraciclina (94% e tetraciclina (89,5% e os menores índices de resistência para neomicina (55%, ceftiofur (57,4%. Quanto às amostras de Salmonella spp, estas apresentaram maior resistência à oxitetraciclina (77%, e à tetraciclina (42,1% e menor à gentamicina (3,5% e amoxicilina (4,8%.Infectious bacterial enteritis causes severe losses to the swine industry worldwide. The objective of this study was to determine the epidemiology of bacterial agents that are associated with the occurrence of diarrhea in pigs at different age groups, and to verify the profile of resistance of strains of Escherichia coli and Salmonella spp to the main antimicrobial agents. The main bacterial species diagnosed were Escherichia coli, Clostridium spp, Salmonella spp, Brachyspira hyodysenteriae, Brachyspira pilosicoli and Lawsonia intracellularis. The E. coli virulence factors of higher prevalence in preweaning piglets were F5 / (K99 20%, F6 / (987P 16.3%, F42 6.8% and F41 5.7%, whereas at the nursery and with

  5. A CRM domain protein functions dually in group I and group II intron splicing in land plant chloroplasts.

    Science.gov (United States)

    Asakura, Yukari; Barkan, Alice

    2007-12-01

    The CRM domain is a recently recognized RNA binding domain found in three group II intron splicing factors in chloroplasts, in a bacterial protein that associates with ribosome precursors, and in a family of uncharacterized proteins in plants. To elucidate the functional repertoire of proteins with CRM domains, we studied CFM2 (for CRM Family Member 2), which harbors four CRM domains. RNA coimmunoprecipitation assays showed that CFM2 in maize (Zea mays) chloroplasts is associated with the group I intron in pre-trnL-UAA and group II introns in the ndhA and ycf3 pre-mRNAs. T-DNA insertions in the Arabidopsis thaliana ortholog condition a defective-seed phenotype (strong allele) or chlorophyll-deficient seedlings with impaired splicing of the trnL group I intron and the ndhA, ycf3-int1, and clpP-int2 group II introns (weak alleles). CFM2 and two previously described CRM proteins are bound simultaneously to the ndhA and ycf3-int1 introns and act in a nonredundant fashion to promote their splicing. With these findings, CRM domain proteins are implicated in the activities of three classes of catalytic RNA: group I introns, group II introns, and 23S rRNA.

  6. Biodegradation of Leonardite by an alkali-producing bacterial community and characterization of the degraded products.

    Science.gov (United States)

    Gao, Tong-Guo; Jiang, Feng; Yang, Jin-Shui; Li, Bao-Zhen; Yuan, Hong-Li

    2012-03-01

    In this study, three bacterial communities were obtained from 12 Leonardite samples with the aim of identifying a clean, effective, and economic technique for the dissolution of Leonardite, a type of low-grade coal, in the production of humic acid (HA). The biodegradation ability and characteristics of the degraded products of the most effective bacterial community (MCSL-2), which degraded 50% of the Leonardite within 21 days, were further investigated. Analyses of elemental composition, (13)C NMR, and Fourier transform infrared revealed that the contents of C, O, and aliphatic carbon were similar in biodegraded humic acid (bHA) and chemically (alkali) extracted humic acid (cHA). However, the N and carboxyl carbon contents of bHA was higher than that of cHA. Furthermore, a positive correlation was identified between the degradation efficiency and the increasing pH of the culture medium, while increases of manganese peroxidase and esterase activities were also observed. These data demonstrated that both alkali production and enzyme reactions were involved in Leonardite solubilization by MCSL-2, although the former mechanism predominated. No fungus was observed by microscopy. Only four bacterial phylotypes were recognized, and Bacillus licheniformis-related bacteria were identified as the main group in MCSL-2 by analysis of amplified 16S rRNA genes, thus demonstrating that Leonardite degradation ability has a limited distribution in bacteria. Hormone-like bioactivities of bHA were also detected. In this study, a bacterial community capable of Leonardite degradation was identified and the products characterized. These data implicate the use of such bacteria for the exploitation of Leonardite as a biofertilizer.

  7. Emerging Roles of Toxin-Antitoxin Modules in Bacterial Pathogenesis

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    Barbara Kędzierska

    2016-06-01

    Full Text Available Toxin-antitoxin (TA cassettes are encoded widely by bacteria. The modules typically comprise a protein toxin and protein or RNA antitoxin that sequesters the toxin factor. Toxin activation in response to environmental cues or other stresses promotes a dampening of metabolism, most notably protein translation, which permits survival until conditions improve. Emerging evidence also implicates TAs in bacterial pathogenicity. Bacterial persistence involves entry into a transient semi-dormant state in which cells survive unfavorable conditions including killing by antibiotics, which is a significant clinical problem. TA complexes play a fundamental role in inducing persistence by downregulating cellular metabolism. Bacterial biofilms are important in numerous chronic inflammatory and infectious diseases and cause serious therapeutic problems due to their multidrug tolerance and resistance to host immune system actions. Multiple TAs influence biofilm formation through a network of interactions with other factors that mediate biofilm production and maintenance. Moreover, in view of their emerging contributions to bacterial virulence, TAs are potential targets for novel prophylactic and therapeutic approaches that are required urgently in an era of expanding antibiotic resistance. This review summarizes the emerging evidence that implicates TAs in the virulence profiles of a diverse range of key bacterial pathogens that trigger serious human disease.

  8. Cooperative Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2009-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a novel optimization algorithm based on the social foraging behavior of E. coli bacteria. This paper presents a variation on the original BFO algorithm, namely, the Cooperative Bacterial Foraging Optimization (CBFO, which significantly improve the original BFO in solving complex optimization problems. This significant improvement is achieved by applying two cooperative approaches to the original BFO, namely, the serial heterogeneous cooperation on the implicit space decomposition level and the serial heterogeneous cooperation on the hybrid space decomposition level. The experiments compare the performance of two CBFO variants with the original BFO, the standard PSO and a real-coded GA on four widely used benchmark functions. The new method shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  9. Bacterial assays for recombinagens.

    Science.gov (United States)

    Hoffmann, G R

    1992-12-01

    Two principal strategies have been used for studying recombinagenic effects of chemicals and radiation in bacteria: (1) measurement of homologous recombination involving defined alleles in a partially diploid strain, and (2) measurement of the formation and loss of genetic duplications in the bacterial chromosome. In the former category, most methods involve one allele in the bacterial chromosome and another in a plasmid, but it is also possible to detect recombination between two chromosomal alleles or between two extrachromosomal alleles. This review summarizes methods that use each of these approaches for detecting recombination and tabulates data on agents that have been found to be recombinagenic in bacteria. The assays are discussed with respect to their effectiveness in testing for recombinagens and their potential for elucidating mechanisms underlying recombinagenic effects.

  10. Bacterial microbiome of lungs in COPD

    Directory of Open Access Journals (Sweden)

    Sze MA

    2014-02-01

    Full Text Available Marc A Sze,1 James C Hogg,2 Don D Sin1 1Department of Medicine, 2Department of Pathology and Laboratory Medicine, The James Hogg Research Centre, Providence Heart-Lung Institute, St Paul's Hospital, University of British Columbia, Vancouver, BC, Canada Abstract: Chronic obstructive pulmonary disease (COPD is currently the third leading cause of death in the world. Although smoking is the main risk factor for this disease, only a minority of smokers develop COPD. Why this happens is largely unknown. Recent discoveries by the human microbiome project have shed new light on the importance and richness of the bacterial microbiota at different body sites in human beings. The microbiota plays a particularly important role in the development and functional integrity of the immune system. Shifts or perturbations in the microbiota can lead to disease. COPD is in part mediated by dysregulated immune responses to cigarette smoke and other environmental insults. Although traditionally the lung has been viewed as a sterile organ, by using highly sensitive genomic techniques, recent reports have identified diverse bacterial communities in the human lung that may change in COPD. This review summarizes the current knowledge concerning the lung microbiota in COPD and its potential implications for pathogenesis of the disease. Keywords: chronic obstructive pulmonary disease, bacterial microbiome, lungs

  11. Bacterial transformation of terpenoids

    Science.gov (United States)

    Grishko, V. V.; Nogovitsina, Y. M.; Ivshina, I. B.

    2014-04-01

    Data on the bacterial transformation of terpenoids published in the literature in the past decade are analyzed. Possible pathways for chemo-, regio- and stereoselective modifications of terpenoids are discussed. Considerable attention is given to new technological approaches to the synthesis of terpenoid derivatives suitable for the use in the perfume and food industry and promising as drugs and chiral intermediates for fine organic synthesis. The bibliography includes 246 references.

  12. Spontaneous bacterial peritonitis

    OpenAIRE

    Al Amri Saleh

    1995-01-01

    Spontaneous bacterial peritonitis (SBP) is an infection of the ascitic fluid without obvious intra-abdominal source of sepsis; usually complicates advanced liver disease. The pathogenesis of the disease is multifactorial: low ascitic protein-content, which reflects defi-cient ascitic fluid complement and hence, reduced opsonic activity is thought to be the most important pathogenic factor. Frequent and prolonged bacteremia has been considered as another pertinent cause of SBP. This disease is...

  13. Modelling bacterial speciation

    OpenAIRE

    2006-01-01

    A central problem in understanding bacterial speciation is how clusters of closely related strains emerge and persist in the face of recombination. We use a neutral Fisher–Wright model in which genotypes, defined by the alleles at 140 house-keeping loci, change in each generation by mutation or recombination, and examine conditions in which an initially uniform population gives rise to resolved clusters. Where recombination occurs at equal frequency between all members of the population, we o...

  14. Adaptive Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2011-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a recently developed nature-inspired optimization algorithm, which is based on the foraging behavior of E. coli bacteria. Up to now, BFO has been applied successfully to some engineering problems due to its simplicity and ease of implementation. However, BFO possesses a poor convergence behavior over complex optimization problems as compared to other nature-inspired optimization techniques. This paper first analyzes how the run-length unit parameter of BFO controls the exploration of the whole search space and the exploitation of the promising areas. Then it presents a variation on the original BFO, called the adaptive bacterial foraging optimization (ABFO, employing the adaptive foraging strategies to improve the performance of the original BFO. This improvement is achieved by enabling the bacterial foraging algorithm to adjust the run-length unit parameter dynamically during algorithm execution in order to balance the exploration/exploitation tradeoff. The experiments compare the performance of two versions of ABFO with the original BFO, the standard particle swarm optimization (PSO and a real-coded genetic algorithm (GA on four widely-used benchmark functions. The proposed ABFO shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  15. Etiology of bacterial vaginosis and polymicrobial biofilm formation.

    Science.gov (United States)

    Jung, Hyun-Sul; Ehlers, Marthie M; Lombaard, Hennie; Redelinghuys, Mathys J; Kock, Marleen M

    2017-03-30

    Microorganisms in nature rarely exist in a planktonic form, but in the form of biofilms. Biofilms have been identified as the cause of many chronic and persistent infections and have been implicated in the etiology of bacterial vaginosis (BV). Bacterial vaginosis is the most common form of vaginal infection in women of reproductive age. Similar to other biofilm infections, BV biofilms protect the BV-related bacteria against antibiotics and cause recurrent BV. In this review, an overview of BV-related bacteria, conceptual models and the stages involved in the polymicrobial BV biofilm formation will be discussed.

  16. Detection of intracellular bacterial communities in human urinary tract infection.

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    David A Rosen

    2007-12-01

    Full Text Available BACKGROUND: Urinary tract infections (UTIs are one of the most common bacterial infections and are predominantly caused by uropathogenic Escherichia coli (UPEC. While UTIs are typically considered extracellular infections, it has been recently demonstrated that UPEC bind to, invade, and replicate within the murine bladder urothelium to form intracellular bacterial communities (IBCs. These IBCs dissociate and bacteria flux out of bladder facet cells, some with filamentous morphology, and ultimately establish quiescent intracellular reservoirs that can seed recurrent infection. This IBC pathogenic cycle has not yet been investigated in humans. In this study we sought to determine whether evidence of an IBC pathway could be found in urine specimens from women with acute UTI. METHODS AND FINDINGS: We collected midstream, clean-catch urine specimens from 80 young healthy women with acute uncomplicated cystitis and 20 asymptomatic women with a history of UTI. Investigators were blinded to culture results and clinical history. Samples were analyzed by light microscopy, immunofluorescence, and electron microscopy for evidence of exfoliated IBCs and filamentous bacteria. Evidence of IBCs was found in 14 of 80 (18% urines from women with UTI. Filamentous bacteria were found in 33 of 80 (41% urines from women with UTI. None of the 20 urines from the asymptomatic comparative group showed evidence of IBCs or filaments. Filamentous bacteria were present in all 14 of the urines with IBCs compared to 19 (29% of 66 samples with no evidence of IBCs (p < 0.001. Of 65 urines from patients with E. coli infections, 14 (22% had evidence of IBCs and 29 (45% had filamentous bacteria, while none of the gram-positive infections had IBCs or filamentous bacteria. CONCLUSIONS: The presence of exfoliated IBCs and filamentous bacteria in the urines of women with acute cystitis suggests that the IBC pathogenic pathway characterized in the murine model may occur in humans. The

  17. Diverse Bacterial PKS Sequences Derived From Okadaic Acid-Producing Dinoflagellates

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    Kathleen S. Rein

    2008-05-01

    Full Text Available Okadaic acid (OA and the related dinophysistoxins are isolated from dinoflagellates of the genus Prorocentrum and Dinophysis. Bacteria of the Roseobacter group have been associated with okadaic acid producing dinoflagellates and have been previously implicated in OA production. Analysis of 16S rRNA libraries reveals that Roseobacter are the most abundant bacteria associated with OA producing dinoflagellates of the genus Prorocentrum and are not found in association with non-toxic dinoflagellates. While some polyketide synthase (PKS genes form a highly supported Prorocentrum clade, most appear to be bacterial, but unrelated to Roseobacter or Alpha-Proteobacterial PKSs or those derived from other Alveolates Karenia brevis or Crytosporidium parvum.

  18. Tinidazole in the treatment of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Nicola R Armstrong

    2009-06-01

    Full Text Available Nicola R Armstrong1, Janet D Wilson21Department of Infectious Diseases and Sexual Health, Trinity Centre, Bradford, UK; 2The Centre for Sexual Health, The General Infirmary at Leeds, Leeds, UKAbstract: Bacterial vaginosis (BV is the commonest cause of vaginal discharge in women of childbearing age. Oral metronidazole has long been established as an effective therapy in the treatment of BV. However, adverse effects due to metronidazole are frequent and this may lead to problems with adherence to a 7-day course of treatment and subsequently result in treatment failure. Oral tinidazole has been used to treat bacterial vaginosis for over 25 years but in a number of different dosage regimens. Placebo controlled trials have consistently shown increases in cure rate with tinidazole. Longer courses of treatment (eg, 1 g daily for 5 days appear to be more effective than a 2 g oral single dose. Comparative studies suggest that oral tinidazole is equivalent to oral metronidazole, intravaginal clindamycin cream, and intravaginal metronidazole tablets, in efficacy in treating BV. However, tinidazole has a more favorable side effect profile than oral metronidazole notably with better gastrointestinal tolerability and less metallic taste. Bacterial vaginosis is associated with high rates of recurrence and appropriate management of such recurrences can prove difficult. Recurrent BV has been linked with persistence of Gardnerella vaginalis after treatment; however the clinical implications of the possible greater activity of tinidazole against G. vaginalis are not yet clear. Repeated courses of oral metronidazole may be poorly tolerated and an alternative but equally effective treatment that is better tolerated may be preferable. In comparison to oral metronidazole, cost is clearly an issue as oral metronidazole is considerably cheaper and available in generic form. However where avoidance of oral metronidazole is necessary because of side effects, oral

  19. Doctor’s Group Questions Anti--Bacterial Soaps

    Institute of Scientific and Technical Information of China (English)

    季章楠

    2000-01-01

    有一种肥皂称Antibacterial(抗菌的)soaps,此外,还有其他声称能够抗菌的日常用品,如:lotions(洗液)and mouthwashes(漱口水)。本文对其广告宣传的作用(advertise themselves as fighting bacteria or microbes)表示了质疑。主要 原因在于:personal-care products may cause antibiotic resistance.本文提出一个重要的概念:excessive use of antibiotics。这使我们想起了中国的一句老话:过犹不及。

  20. Doctor’s Group Questions Anti-Bacterial Soaps

    Institute of Scientific and Technical Information of China (English)

    Alexander; Caillet; 张倩

    2004-01-01

    美国一个主要的医师组织最近说,消毒肥皂的抗菌效果也许并不比普通肥皂好,可能还是使细菌产生抗药性的危险征兆之一。但是一个行业组织对此进行了反驳,认为消毒类产品能杀灭或抑制导致皮肤感染,肠道疾病或其它常见传染病的细菌的生长。双方在这一问题上可谓是针锋相对,互不相让。读者诸君如何选择使用肥皂类物品,看来暂时只能凭你的"慧眼"了。

  1. Bacterial ice nucleation: significance and molecular basis.

    Science.gov (United States)

    Gurian-Sherman, D; Lindow, S E

    1993-11-01

    Several bacterial species are able to catalyze ice formation at temperatures as warm as -2 degrees C. These microorganisms efficiently catalyze ice formation at temperatures much higher than most organic or inorganic substances. Because of their ubiquity on the surfaces of frost-sensitive plants, they are responsible for initiating ice formation, which results in frost injury. The high temperature of ice catalysis conferred by bacterial ice nuclei makes them useful in ice nucleation-limited processes such as artificial snow production, the freezing of some food products, and possibly in future whether modification schemes. The rarity of other ice nuclei active at high subfreezing temperature, and the ease and sensitivity with which ice nuclei can be quantified, have made the use of a promoterless bacterial ice nucleation gene valuable as a reporter of transcription. Target genes to which this promoter is fused can be used in cells in natural habitats. Warm-temperature ice nucleation sites have also been extensively studied at a molecular level. Nucleation sites active at high temperatures (above -5 degrees C) are probably composed of bacterial ice nucleation protein molecules that form functionally aligned aggregates. Models of ice nucleation proteins predict that they form a planar array of hydrogen binding groups that closely complement that of an ice crystal face. Moreover, interdigitation of these molecules may produce a large contiguous template for ice formation.

  2. Bacterial chromosome segregation.

    Science.gov (United States)

    Possoz, Christophe; Junier, Ivan; Espeli, Olivier

    2012-01-01

    Dividing cells have mechanisms to ensure that their genomes are faithfully segregated into daughter cells. In bacteria, the description of these mechanisms has been considerably improved in the recent years. This review focuses on the different aspects of bacterial chromosome segregation that can be understood thanks to the studies performed with model organisms: Escherichia coli, Bacillus subtilis, Caulobacter crescentus and Vibrio cholerae. We describe the global positionning of the nucleoid in the cell and the specific localization and dynamics of different chromosomal loci, kinetic and biophysic aspects of chromosome segregation are presented. Finally, a presentation of the key proteins involved in the chromosome segregation is made.

  3. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    This PhD project was carried out as part of the Microbial Remediation of Contaminated Soil and Water Resources (MIRESOWA) project, funded by the Danish Council for Strategic Research (grant number 2104-08-0012). The environment is contaminated with various xenobiotic compounds e.g. pesticides......D student, to construct fungal-bacterial consortia in order to potentially stimulate pesticide degradation thereby increasing the chance of successful bioaugmentation. The results of the project are reported in three article manuscripts, included in this thesis. In manuscript I, the mineralization of 2...

  4. Spontaneous bacterial peritonitis

    Directory of Open Access Journals (Sweden)

    Al Amri Saleh

    1995-01-01

    Full Text Available Spontaneous bacterial peritonitis (SBP is an infection of the ascitic fluid without obvious intra-abdominal source of sepsis; usually complicates advanced liver disease. The pathogenesis of the disease is multifactorial: low ascitic protein-content, which reflects defi-cient ascitic fluid complement and hence, reduced opsonic activity is thought to be the most important pathogenic factor. Frequent and prolonged bacteremia has been considered as another pertinent cause of SBP. This disease is associated with high mortality and recurrence. Therefore, orompt recognition and institution of therapy and plan of prophylaxis is vital.

  5. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte;

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the Par......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome....

  6. Bacterial selection by mycospheres of Atlantic Rainforest mushrooms.

    Science.gov (United States)

    Halsey, Joshua Andrew; de Cássia Pereira E Silva, Michele; Andreote, Fernando Dini

    2016-10-01

    This study focuses on the selection exerted on bacterial communities in the mycospheres of mushrooms collected in the Brazilian Atlantic Rainforest. A total of 24 paired samples (bulk soil vs. mycosphere) were assessed to investigate potential interactions between fungi and bacteria present in fungal mycospheres. Prevalent fungal families were identified as Marasmiaceae and Lepiotaceae (both Basidiomycota) based on ITS partial sequencing. We used culture-independent techniques to analyze bacterial DNA from soil and mycosphere samples. Bacterial communities in the samples were distinguished based on overall bacterial, alphaproteobacterial, and betaproteobacterial PCR-DGGE patterns, which were different in fungi belonging to different taxa. These results were confirmed by pyrosequencing the V4 region of the 16S rRNA gene (based on five bulk soil vs. mycosphere pairs), which revealed the most responsive bacterial families in the different conditions generated beneath the mushrooms, identified as Bradyrhizobiaceae, Burkholderiaceae, and Pseudomonadaceae. The bacterial families Acetobacteraceae, Chrhoniobacteraceae, Planctomycetaceae, Conexibacteraceae, and Burkholderiaceae were found in all mycosphere samples, composing the core mycosphere microbiome. Similarly, some bacterial groups identified as Koribacteriaceae, Acidobacteria (Solibacteriaceae) and an unclassified group of Acidobacteria were preferentially present in the bulk soil samples (found in all of them). In this study we depict the mycosphere effect exerted by mushrooms inhabiting the Brazilian Atlantic Rainforest, and identify the bacteria with highest response to such a specific niche, possibly indicating the role bacteria play in mushroom development and dissemination within this yet-unexplored environment.

  7. Perceiving persons and groups.

    Science.gov (United States)

    Hamilton, D L; Sherman, S J

    1996-04-01

    This article analyzes the similarities and differences in forming impressions of individuals and in developing conceptions of groups. In both cases, the perceiver develops a mental conception of the target (individual or group) on the basis of available information and uses that information to make judgments about that person or group. However, a review of existing evidence reveals differences in the outcomes of impressions formed of individual and group targets, even when those impressions are based on the very same behavioral information. A model is proposed to account for these differences. The model emphasizes the role of differing expectancies of unity and coherence in individual and group targets, which in turn engage different mechanisms for processing information and making judgments. Implications of the model are discussed.

  8. Impairment of the bacterial biofilm stability by triclosan.

    Directory of Open Access Journals (Sweden)

    Helen V Lubarsky

    Full Text Available The accumulation of the widely-used antibacterial and antifungal compound triclosan (TCS in freshwaters raises concerns about the impact of this harmful chemical on the biofilms that are the dominant life style of microorganisms in aquatic systems. However, investigations to-date rarely go beyond effects at the cellular, physiological or morphological level. The present paper focuses on bacterial biofilms addressing the possible chemical impairment of their functionality, while also examining their substratum stabilization potential as one example of an important ecosystem service. The development of a bacterial assemblage of natural composition--isolated from sediments of the Eden Estuary (Scotland, UK--on non-cohesive glass beads (<63 µm and exposed to a range of triclosan concentrations (control, 2-100 µg L(-1 was monitored over time by Magnetic Particle Induction (MagPI. In parallel, bacterial cell numbers, division rate, community composition (DGGE and EPS (extracellular polymeric substances: carbohydrates and proteins secretion were determined. While the triclosan exposure did not prevent bacterial settlement, biofilm development was increasingly inhibited by increasing TCS levels. The surface binding capacity (MagPI of the assemblages was positively correlated to the microbial secreted EPS matrix. The EPS concentrations and composition (quantity and quality were closely linked to bacterial growth, which was affected by enhanced TCS exposure. Furthermore, TCS induced significant changes in bacterial community composition as well as a significant decrease in bacterial diversity. The impairment of the stabilization potential of bacterial biofilm under even low, environmentally relevant TCS levels is of concern since the resistance of sediments to erosive forces has large implications for the dynamics of sediments and associated pollutant dispersal. In addition, the surface adhesive capacity of the biofilm acts as a sensitive measure of

  9. Molecular characterization of conjugative plasmids in pesticide tolerant and multi-resistant bacterial isolates from contaminated alluvial soil.

    Science.gov (United States)

    Anjum, Reshma; Grohmann, Elisabeth; Malik, Abdul

    2011-06-01

    A total of 35 bacteria from contaminated soil (cultivated fields) near pesticide industry from Chinhat, Lucknow, (India) were isolated and tested for their tolerance/resistance to pesticides, heavy metals and antibiotics. Bacterial isolates were identified by 16S rDNA sequencing. Gas Chromatography analysis of the soil samples revealed the presence of lindane at a concentration of 547 ng g(-1) and α-endosulfan and β-endosulfan of 422 ng g(-1) and 421 ng g(-1) respectively. Atomic Absorption Spectrophotometry analysis of the test sample was done and Cr, Zn, Ni, Fe, Cu and Cd were detected at concentrations of 36.2, 42.5, 43.2, 241, 13.3 and 11.20 mg kg(-1) respectively. Minimum inhibitory concentrations of all the isolates were determined for pesticides and heavy metals. All the multi-resistant/tolerant bacterial isolates were also tested for the presence of incompatibility (Inc) group IncP, IncN, IncW, IncQ plasmids and for rolling circle plasmids of the pMV158-family by PCR. Total community DNA was extracted from pesticide contaminated soil. PCR amplification of the bacterial isolates and soil DNA revealed the presence of IncP-specific sequences (trfA2 and oriT) which was confirmed by dot blot hybridization with RP4-derived DIG-labelled probes. Plasmids belonging to IncN, IncW and IncQ group were neither detected in the bacterial isolates nor in total soil DNA. The presence of conjugative or mobilizable IncP plasmids in the isolates indicate that these bacteria have gene transfer capacity with implications for dissemination of heavy metal and antibiotic resistance genes. We propose that IncP plasmids are mainly responsible for the spread of multi-resistant bacteria in the contaminated soils.

  10. Spontaneous bacterial peritonitis

    Institute of Scientific and Technical Information of China (English)

    Anastasios Koulaouzidis; Shivaram Bhat; Athar A Saeed

    2009-01-01

    Since its initial description in 1964, research has transformed spontaneous bacterial peritonitis (SBP) from a feared disease (with reported mortality of 90%) to a treatable complication of decompensated cirrhosis,albeit with steady prevalence and a high recurrence rate. Bacterial translocation, the key mechanism in the pathogenesis of SBP, is only possible because of the concurrent failure of defensive mechanisms in cirrhosis.Variants of SBP should be treated. Leucocyte esterase reagent strips have managed to shorten the 'tap-toshot' time, while future studies should look into their combined use with ascitic fluid pH. Third generation cephalosporins are the antibiotic of choice because they have a number of advantages. Renal dysfunction has been shown to be an independent predictor of mortality in patients with SBP. Albumin is felt to reduce the risk of renal impairment by improving effective intravascular volume, and by helping to bind proinflammatory molecules. Following a single episode of SBP, patients should have long-term antibiotic prophylaxis and be considered for liver transplantation.

  11. Antimicrobials for bacterial bioterrorism agents.

    Science.gov (United States)

    Sarkar-Tyson, Mitali; Atkins, Helen S

    2011-06-01

    The limitations of current antimicrobials for highly virulent pathogens considered as potential bioterrorism agents drives the requirement for new antimicrobials that are suitable for use in populations in the event of a deliberate release. Strategies targeting bacterial virulence offer the potential for new countermeasures to combat bacterial bioterrorism agents, including those active against a broad spectrum of pathogens. Although early in the development of antivirulence approaches, inhibitors of bacterial type III secretion systems and cell division mechanisms show promise for the future.

  12. Group X

    Energy Technology Data Exchange (ETDEWEB)

    Fields, Susannah

    2007-08-16

    This project is currently under contract for research through the Department of Homeland Security until 2011. The group I was responsible for studying has to remain confidential so as not to affect the current project. All dates, reference links and authors, and other distinguishing characteristics of the original group have been removed from this report. All references to the name of this group or the individual splinter groups has been changed to 'Group X'. I have been collecting texts from a variety of sources intended for the use of recruiting and radicalizing members for Group X splinter groups for the purpose of researching the motivation and intent of leaders of those groups and their influence over the likelihood of group radicalization. This work included visiting many Group X websites to find information on splinter group leaders and finding their statements to new and old members. This proved difficult because the splinter groups of Group X are united in beliefs, but differ in public opinion. They are eager to tear each other down, prove their superiority, and yet remain anonymous. After a few weeks of intense searching, a list of eight recruiting texts and eight radicalizing texts from a variety of Group X leaders were compiled.

  13. Hopanoids as functional analogues of cholesterol in bacterial membranes.

    Science.gov (United States)

    Sáenz, James P; Grosser, Daniel; Bradley, Alexander S; Lagny, Thibaut J; Lavrynenko, Oksana; Broda, Martyna; Simons, Kai

    2015-09-22

    The functionality of cellular membranes relies on the molecular order imparted by lipids. In eukaryotes, sterols such as cholesterol modulate membrane order, yet they are not typically found in prokaryotes. The structurally similar bacterial hopanoids exhibit similar ordering properties as sterols in vitro, but their exact physiological role in living bacteria is relatively uncharted. We present evidence that hopanoids interact with glycolipids in bacterial outer membranes to form a highly ordered bilayer in a manner analogous to the interaction of sterols with sphingolipids in eukaryotic plasma membranes. Furthermore, multidrug transport is impaired in a hopanoid-deficient mutant of the gram-negative Methylobacterium extorquens, which introduces a link between membrane order and an energy-dependent, membrane-associated function in prokaryotes. Thus, we reveal a convergence in the architecture of bacterial and eukaryotic membranes and implicate the biosynthetic pathways of hopanoids and other order-modulating lipids as potential targets to fight pathogenic multidrug resistance.

  14. The Historical Image of Chinese Teaching of the "Baima Lake Writer Group" and Its Implications%"白马湖作家群"国文教学的历史影像和现实启迪

    Institute of Scientific and Technical Information of China (English)

    潘涌; 郭雅莲

    2016-01-01

    "五四"以后,以朱自清、夏丏尊、丰子恺、叶圣陶等为代表的文人汇聚在浙江上虞白马湖畔的春晖中学从事教学和写作活动.他们以文会友、教学相长、切磋互补,创造出一种超越尘世、清新脱俗的纯粹的教育境界即"春晖境界". "白马湖作家群"以卓越的文学才华、高洁的人格风范以及诚挚朴素、超然物外的教学风格在民国教育史上留下了清晰的历史影像,并为今天全面深化基础教育改革时期探索语文教师专业化发展路径、深远培育新国民的母语文化软实力提供了有益的现实启迪.%Since the May 4th Movement, some scholars like Zhu Ziqing, Xia Mianzun, Feng Zikai and Ye Shengtao ,worked in Chunhui secondary school by the lakeside of Baima Lake in Shangyu city , Zhejiang prov-ince.They taught and wrote there , and befriended each other , sharing similar interests in literature; they learned from each other in teaching and they were free from things of the world , showing a pure teaching ide-al, which was since referred to as "Chunhui Ideal".The writer group left a clear image in the history of edu-cation over the Republic of China ,with their excellent literary talent , noble personality and sincere and simple teaching styles .They also provided a way for Chinese teachers professional development and may have further implications for the strenthening of native culture as soft power .

  15. 美国集团采购组织分析及对我国药品采购的启示%Analysis on the group purchasing organizations in the United States and its implications for Chinese drug procurement

    Institute of Scientific and Technical Information of China (English)

    邵蓉; 谢金平; 蒋蓉

    2014-01-01

    本文采用文献研究法,详细地分析了美国集团采购组织的基本特质及其对医疗卫生体制的影响。主要内容包括集团采购组织在美国的发展历程、组织类型、基本职能、采购药品的流程及其主要费用来源,集团采购组织的特点及对医院、供应商、监管机构产生的影响。研究认为,集团采购组织为美国医疗保健提供方节约了大量成本,在医疗供应链中发挥着重要作用。建议创新与完善我国药品采购制度应更大范围、更深程度地引入市场机制,妥善协调政府与市场在药品采购中的作用;并科学设置评标方法,兼顾药品质量与价格要素,注重采购的经济实用性。%In this paper, basic characteristics of group purchasing organizations ( GPOs) and its implications for US health care system are analyzed using a literature research method. The main contents include the development process, type, basic functions, drug procurement processes, fee sources, characteristics and influence for the hospi-tals, supplies, regulators of GPOs. We suggest that GPOs have helped US health care providers save a lot of money and played an important role in the healthcare supply chain. We also suggest that market mechanisms should be intro-duced widely concerning the model innovation and improvement of domestic drug procurement. At the same time, government and the market should be coordinated properly. Moreover, scientific evaluation methods should be set in consideration of drug quality, prices and its economic practicality.

  16. Characterization of bacterial diversity associated with calcareous deposits and drip-waters, and isolation of calcifying bacteria from two Colombian mines.

    Science.gov (United States)

    García G, Mariandrea; Márquez G, Marco Antonio; Moreno H, Claudia Ximena

    2016-01-01

    Bacterial carbonate precipitation has implications in geological processes and important biotechnological applications. Bacteria capable of precipitating carbonates have been isolated from different calcium carbonate deposits (speleothems) in caves, soil, freshwater and seawater around the world. However, the diversity of bacteria from calcareous deposits in Colombia, and their ability to precipitate carbonates, remains unknown. In this study, conventional microbiological methods and molecular tools, such as temporal temperature gradient electrophoresis (TTGE), were used to assess the composition of bacterial communities associated with carbonate deposits and drip-waters from two Colombian mines. A genetic analysis of these bacterial communities revealed a similar level of diversity, based on the number of bands detected using TTGE. The dominant phylogenetic affiliations of the bacteria, determined using 16S rRNA gene sequencing, were grouped into two phyla: Proteobacteria and Firmicutes. Within these phyla, seven genera were capable of precipitating calcium carbonates: Lysinibacillus, Bacillus, Strenotophomonas, Brevibacillus, Methylobacterium, Aeromicrobium and Acinetobacter. FTIR and SEM/EDX were used to analyze calcium carbonate crystals produced by isolated Acinetobacter gyllenbergii. The results showed that rhombohedral and angular calcite crystals with sizes of 90μm were precipitated. This research provides information regarding the presence of complex bacterial communities in secondary carbonate deposits from mines and their ability to precipitate calcium carbonate from calcareous deposits of Colombian mines.

  17. Silver-nanoparticle-coated biliary stent inhibits bacterial adhesion in bacterial cholangitis in swine

    Institute of Scientific and Technical Information of China (English)

    Wei Wen; Li-Mei Ma; Wei He; Xiao-Wei Tang; Yin Zhang; Xiang Wang; Li Liu; Zhi-Ning Fan

    2016-01-01

    BACKGROUND: One of the major limitations of biliary stents is the stent occlusion, which is closely related to the over-growth of bacteria. This study aimed to evaluate the feasibility of a novel silver-nanoparticle-coated polyurethane (Ag/PU) stent in bacterial cholangitis model in swine. METHODS: Ag/PU was designed by coating silver nanopar-ticles on polyurethane (PU) stent. Twenty-four healthy pigs with bacterial cholangitis using Ag/PU and PU stents were ran-domly divided into an Ag/PU stent group (n=12) and a PU stent group (n=12), respectively. The stents were inserted by standard endoscopic retrograde cholangiopancreatography. Laboratory assay was performed for white blood cell (WBC) count, alanine aminotransferase (ALT), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) at baseline time, 8 hours, 1, 2, 3, and 7 days after stent placements. The segment of bile duct containing the stent was examined histologically ex vivo. Implanted bili-ary stents were examined by a scan electron microscope. The amount of silver release was also measured in vitro. RESULTS: The number of inflammatory cells and level of ALT, IL-1β and TNF-α were significantly lower in the Ag/PU stent group than in the PU stent group. Hyperplasia of the mucosa was more severe in the PU stent group than in the Ag/PU stent group. In contrast to the biofilm of bacteria on the PU stent, fewer bacteria adhered to the Ag/PU stent. CONCLUSIONS: PU biliary stents modified with silver nanoparticles are able to alleviate the inflammation of pigs with bacterial cholangitis. Silver-nanoparticle-coated stents are resistant to bacterial adhesion.

  18. Animals in a bacterial world: opportunities for chemical ecology.

    Science.gov (United States)

    Cantley, Alexandra M; Clardy, Jon

    2015-07-01

    This Viewpoint article provides a brief and selective summary of research on the chemical ecology underlying symbioses between bacteria and animals. Animals engage in multiple highly specialized interactions with bacteria that reflect their long coevolutionary history. The article focuses on a few illustrative but hardly exhaustive examples in which bacterially produced small molecules initiate a developmental step with important implications for the evolution of animals, provide signals for the maturation of mammalian immune systems, and furnish chemical defenses against microbial pathogens.

  19. Relationship between Intrauterine Bacterial Infection and Early Embryonic Developmental Arrest

    Institute of Scientific and Technical Information of China (English)

    Shao-Fei Yan; Xin-Yan Liu; Yun-Fei Cheng; Zhi-Yi Li; Jie Ou; Wei Wang; Feng-Qin Li

    2016-01-01

    Background:Early embryonic developmental arrest is the most commonly understudied adverse outcome of pregnancy.The relevance of intrauterine infection to spontaneous embryonic death is rarely studied and remains unclear.This study aimed to investigate the relationship between intrauterine bacterial infection and early embryonic developmental arrest.Methods:Embryonic chorion tissue and uterine swabs for bacterial detection were obtained from 33 patients who underwent artificial abortion (control group) and from 45 patients who displayed early embryonic developmental arrest (trial group).Results:Intrauterine bacterial infection was discovered in both groups.The infection rate was 24.44% (11/45) in the early embryonic developmental arrest group and 9.09% (3/33) in the artificial abortion group.Classification analysis revealed that the highest detection rate for Micrococcus luteus in the early embryonic developmental arrest group was 13.33% (6/45),and none was detected in the artificial abortion group.M.luteus infection was significantly different between the groups (P < 0.05 as shown by Fisher's exact test).In addition,no correlation was found between intrauterine bacterial infection and history of early embryonic developmental arrest.Conclusions:M.luteus infection is related to early embryonic developmental arrest and might be one of its causative factors.

  20. Group morphology

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2000-01-01

    In its original form, mathematical morphology is a theory of binary image transformations which are invariant under the group of Euclidean translations. This paper surveys and extends constructions of morphological operators which are invariant under a more general group TT, such as the motion group

  1. Implications for directionality of nanoscale forces in bacterial attachment

    OpenAIRE

    Swartjes, Jan J. T. M.; Veeregowda, Deepak H.

    2016-01-01

    Adhesion and friction are closely related and play a predominant role in many natural processes. From the wall-clinging feet of the gecko to bacteria forming a biofilm, in many cases adhesion is a necessity to survive. The direction in which forces are applied has shown to influence the bond strength of certain systems tremendously and can mean the difference between adhesion and detachment. The spatula present on the extension of the feet of the gecko can either attach or detach, based on th...

  2. Bacterial motility in the sea and its ecological implications

    DEFF Research Database (Denmark)

    Grossart, Hans-Peter; Riemann, Lasse; Azam, F.

    2001-01-01

    colonization of living and dead algal cells by bacteria. Filtering seawater through a 1 µm filter reduced % motile, again suggesting the importance of particulate loci. Enrichment with dissolved organic nutrients enhanced % motile only after 6 h but it rapidly (=1 h) increased the time individual bacteria were...

  3. Protein Oxidation Implicated as the Primary Determinant of Bacterial Radioresistance

    Science.gov (United States)

    2007-04-01

    the facultative anaerobic, radio- resistant bacterium Lactobacillus plantarum [1,22] accumulates 20–25 mM Mn(II) [23]. For an irradiated cell...in dH2O at 0 8C and pre-conditioned to be anaerobic, H2O2 was released by D. radiodurans (;23 105 M) and L. plantarum (;6 3 105 M), in which the...non-irradiated D. radiodurans or L. plantarum control samples, nor by irradiated S. oneidensis (Figure 5A), which accumulates substantially more Fe

  4. Epigenetics and bacterial infections.

    Science.gov (United States)

    Bierne, Hélène; Hamon, Mélanie; Cossart, Pascale

    2012-12-01

    Epigenetic mechanisms regulate expression of the genome to generate various cell types during development or orchestrate cellular responses to external stimuli. Recent studies highlight that bacteria can affect the chromatin structure and transcriptional program of host cells by influencing diverse epigenetic factors (i.e., histone modifications, DNA methylation, chromatin-associated complexes, noncoding RNAs, and RNA splicing factors). In this article, we first review the molecular bases of the epigenetic language and then describe the current state of research regarding how bacteria can alter epigenetic marks and machineries. Bacterial-induced epigenetic deregulations may affect host cell function either to promote host defense or to allow pathogen persistence. Thus, pathogenic bacteria can be considered as potential epimutagens able to reshape the epigenome. Their effects might generate specific, long-lasting imprints on host cells, leading to a memory of infection that influences immunity and might be at the origin of unexplained diseases.

  5. Bacterial polyhydroxyalkanoates: Still fabulous?

    Science.gov (United States)

    Możejko-Ciesielska, Justyna; Kiewisz, Robert

    2016-11-01

    Bacterial polyhydroxyalkanoates (PHA) are polyesters accumulated as carbon and energy storage materials under limited growth conditions in the presence of excess carbon sources. They have been developed as biomaterials with unique properties for the past many years being considered as a potential substitute for conventional non-degradable plastics. Due to the increasing concern towards global climate change, depleting petroleum resource and problems with an utilization of a growing number of synthetic plastics, PHAs have gained much more attention from industry and research. These environmentally friendly microbial polymers have great potential in biomedical, agricultural, and industrial applications. However, their production on a large scale is still limited. This paper describes the backgrounds of PHAs and discussed the current state of knowledge on the polyhydroxyalkanoates. Ability of bacteria to convert different carbon sources to PHAs, the opportunities and challenges of their introduction to global market as valuable renewable products have been also discussed.

  6. Antitumor polyketide biosynthesis by an uncultivated bacterial symbiont of the marine sponge Theonella swinhoei.

    Science.gov (United States)

    Piel, Jörn; Hui, Dequan; Wen, Gaiping; Butzke, Daniel; Platzer, Matthias; Fusetani, Nobuhiro; Matsunaga, Shigeki

    2004-11-16

    Bacterial symbionts have long been suspected to be the true producers of many drug candidates isolated from marine invertebrates. Sponges, the most important marine source of biologically active natural products, have been frequently hypothesized to contain compounds of bacterial origin. This symbiont hypothesis, however, remained unproven because of a general inability to cultivate the suspected producers. However, we have recently identified an uncultured Pseudomonas sp. symbiont as the most likely producer of the defensive antitumor polyketide pederin in Paederus fuscipes beetles by cloning the putative biosynthesis genes. Here we report closely related genes isolated from the highly complex metagenome of the marine sponge Theonella swinhoei, which is the source of the onnamides and theopederins, a group of polyketides that structurally resemble pederin. Sequence features of the isolated genes clearly indicate that it belongs to a prokaryotic genome and should be responsible for the biosynthesis of almost the entire portion of the polyketide structure that is correlated with antitumor activity. Besides providing further proof for the role of the related beetle symbiont-derived genes, these findings raise intriguing ecological and evolutionary questions and have important general implications for the sustainable production of otherwise inaccessible marine drugs by using biotechnological strategies.

  7. The Pseudomonas aeruginosa chemotaxis methyltransferase CheR1 impacts on bacterial surface sampling.

    Directory of Open Access Journals (Sweden)

    Juliane Schmidt

    Full Text Available The characterization of factors contributing to the formation and development of surface-associated bacterial communities known as biofilms has become an area of intense interest since biofilms have a major impact on human health, the environment and industry. Various studies have demonstrated that motility, including swimming, swarming and twitching, seems to play an important role in the surface colonization and establishment of structured biofilms. Thereby, the impact of chemotaxis on biofilm formation has been less intensively studied. Pseudomonas aeruginosa has a very complex chemosensory system with two Che systems implicated in flagella-mediated motility. In this study, we demonstrate that the chemotaxis protein CheR1 is a methyltransferase that binds S-adenosylmethionine and transfers a methyl group from this methyl donor to the chemoreceptor PctA, an activity which can be stimulated by the attractant serine but not by glutamine. We furthermore demonstrate that CheR1 does not only play a role in flagella-mediated chemotaxis but that its activity is essential for the formation and maintenance of bacterial biofilm structures. We propose a model in which motility and chemotaxis impact on initial attachment processes, dispersion and reattachment and increase the efficiency and frequency of surface sampling in P. aeruginosa.

  8. BACTERIAL FLORA IN DIABETIC ULCER

    Directory of Open Access Journals (Sweden)

    Anitha Lavanya

    2015-04-01

    Full Text Available BACKGROUND : Diabetic foot infections are one of the most feared complications of diabetes. This study was undertaken to determine the common etiological agents of diabetic foot infections and their in vitro antibiotic susceptibility. METHODS : A prospective study was p erformed over a period of two years in a tertiary care hospital. The aerobic and anaerobic bacterial agents were isolated and their antibiotic susceptibility pattern was determined . RESULTS : One hundred patients with Diabetic ulcer were studied, of which 6 5 were males and 35 were females. Majority of patients were in the age group of 51 to 60 years (37% and polymicrobial etiology was 64 % and monomicrobial etiology was 36%. A total of 187 organisms were isolated of which 165 were aerobic and 22 were anaero bic. Most frequently isolated aerobic organisms were Pseudomonas Sp., Klebsiella Sp., E coli Sp., and Staphylococcus aureus. The common anaerobic organisms isolated were Peptostreptococcus Sp. And Bacterioids Sp. CONCLUSION : High prevalence of multi - drug r esistant pathogens was observed. Amikacin, Imipenem were active against gram - negative bacilli, while vancomycin was found to be active against gram - positive bacteria.

  9. Group devaluation and group identification

    NARCIS (Netherlands)

    Leach, C.W.; Rodriguez Mosquera, P.M.; Vliek, M.L.W.; Hirt, E.

    2010-01-01

    In three studies, we showed that increased in-group identification after (perceived or actual) group devaluation is an assertion of a (preexisting) positive social identity that counters the negative social identity implied in societal devaluation. Two studies with real-world groups used order manip

  10. Bacterial Trapping in Porous Media Flows

    Science.gov (United States)

    Dehkharghani, Amin; Waisbord, Nicolas; Dunkel, Jörn; Guasto, Jeffrey

    2016-11-01

    Swimming bacteria inhabit heterogeneous, microstructured environments that are often characterized by complex, ambient flows. Understanding the physical mechanisms underlying cell transport in these systems is key to controlling important processes such as bioremediation in porous soils and infections in human tissues. We study the transport of swimming bacteria (Bacillus subtilis) in quasi-two-dimensional porous microfluidic channels with a range of periodic microstructures and flow strengths. Measured cell trajectories and the local cell number density reveal the formation of filamentous cell concentration patterns within the porous structures. The local cell densification is maximized at shear rates in the range 1-10 s-1, but widely varies with pore geometry and flow topology. Experimental observations are complemented by Langevin simulations to demonstrate that the filamentous patterns result from a coupling of bacterial motility to the complex flow fields via Jeffery orbits, which effectively 'trap' the bacteria on streamlines. The resulting microscopic heterogeneity observed here suppresses bacterial transport and likely has implications for both mixing and cell nutrient uptake in porous media flows. NSF CBET-1511340.

  11. Bacterial composition in whole saliva from patients with severe hyposalivation

    DEFF Research Database (Denmark)

    Belstrøm, Daniel; Holmstrup, Palle; Fiehn, Nils-Erik

    2016-01-01

    OBJECTIVE: The purpose of this study was to compare the microbiota of stimulated whole saliva samples from patients with severe hyposalivation to samples from individuals with normal whole saliva flow rates. It was hypothesized that the two groups differ with regard to salivary bacterial profiles....... METHODS: This cross-sectional study included 36 participants (24 females and 12 males, mean age 58.5 years) with severe hyposalivation and 36 gender-, age- and geographically-matched participants with normal salivary secretion from the Danish Health Examination Survey (DANHES). The microbiota...... difference in frequency or proportional presence between groups. Furthermore, data reduction by principal component analysis and correspondence analysis showed comparable bacterial community profiles between groups. CONCLUSIONS: The results indicate that the salivary bacterial profiles of patients...

  12. Dynamics of seawater bacterial communities in a shellfish hatchery.

    Science.gov (United States)

    Powell, S M; Chapman, C C; Bermudes, M; Tamplin, M L

    2013-08-01

    Bacterial disease is a significant issue for larviculture of several species of shellfish, including oysters. One source of bacteria is the seawater used throughout the hatchery. In this study carried out at a commercial oyster hatchery in Tasmania, Australia, the diversity of the bacterial community and its relationship with larval production outcomes were studied over a 2-year period using terminal restriction fragment length polymorphism and tag-encoded pyrosequencing. The bacterial communities were very diverse, dominated by the Alphaproteobacteria, Gammaproteobacteria, Flavobacteria and Cyanobacteria. The communities were highly variable on scales of days, weeks and seasons. The difference between the intake seawater and treated clean seawater used in the hatchery was smaller than the observed temporal differences in the seawater throughout the year. No clear correlation was observed between production outcomes and the overall bacterial community structure. However, one group of Cyanobacterial sequences was more abundant when mass mortality events occurred than when healthy spat were produced although they were always present.

  13. Six Considerations for Social Justice Group Work

    Science.gov (United States)

    Singh, Anneliese A.; Salazar, Carmen F.

    2010-01-01

    This article describes "courageous conversations" in social justice group work and a continuum of action for social justice interventions. It analyzes themes from 20 contributions to 2 consecutive special issues of "The Journal for Specialists in Group Work" on social justice group work. Implications for future development in group leadership and…

  14. Bacterial degradation of aminopyrine.

    Science.gov (United States)

    Blecher, H; Blecher, R; Wegst, W; Eberspaecher, J; Lingens, F

    1981-11-01

    1. Four strains of bacteria growing with aminopyrine as sole source of carbon were isolated from soil and were identified as strains of Phenylobacterium immobilis. 2. Strain M13 and strain E, the type species of Phenylobacterium immobilis (DSM 1986), which had been isolated by enrichment with chloridazon (5-amino-4-chloro-2-phenyl-2H-pyridazin-3-one) were used to investigate the bacterial degradation of aminopyrine. 3. Three metabolites were isolated and identified as: 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-(2,3-dihydro-2,3-dihydroxy-4,6-cyc lohexadien-1-yl)-3H-pyrazol-3-one, 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-(2,3-dihydroxyphenyl)-3H-pyrazol-3 -one and 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-3H-pyrazol-3-one. 4. An enzyme extract from cells of strain m13 was shown to further metabolize the catechol derivative of aminopyrine, with the formation of 2-pyrone-6-carboxylic acid. 5. Results indicate that the benzene ring of aminopyrine is the principal site of microbial metabolism.

  15. Electromagnetism of Bacterial Growth

    Science.gov (United States)

    Ainiwaer, Ailiyasi

    2011-10-01

    There has been increasing concern from the public about personal health due to the significant rise in the daily use of electrical devices such as cell phones, radios, computers, GPS, video games and television. All of these devices create electromagnetic (EM) fields, which are simply magnetic and electric fields surrounding the appliances that simultaneously affect the human bio-system. Although these can affect the human system, obstacles can easily shield or weaken the electrical fields; however, magnetic fields cannot be weakened and can pass through walls, human bodies and most other objects. The present study was conducted to examine the possible effects of bacteria when exposed to magnetic fields. The results indicate that a strong causal relationship is not clear, since different magnetic fields affect the bacteria differently, with some causing an increase in bacterial cells, and others causing a decrease in the same cells. This phenomenon has yet to be explained, but the current study attempts to offer a mathematical explanation for this occurrence. The researchers added cultures to the magnetic fields to examine any effects to ion transportation. Researchers discovered ions such as potassium and sodium are affected by the magnetic field. A formula is presented in the analysis section to explain this effect.

  16. Evolution of Bacterial Suicide

    Science.gov (United States)

    Tchernookov, Martin; Nemenman, Ilya

    2013-03-01

    While active, controlled cellular suicide (autolysis) in bacteria is commonly observed, it has been hard to argue that autolysis can be beneficial to an individual who commits it. We propose a theoretical model that predicts that bacterial autolysis is evolutionarily advantageous to an individualand would fixate in physically structured environments for stationary phase colonies. We perform spatially resolved agent-based simulations of the model, which predict that lower mixing in the environment results in fixation of a higher autolysis rate from a single mutated cell, regardless of the colony's genetic diversity. We argue that quorum sensing will fixate as well, even if initially rare, if it is coupled to controlling the autolysis rate. The model does not predict a strong additional competitive advantage for cells where autolysis is controlled by quorum sensing systems that distinguish self from nonself. These predictions are broadly supported by recent experimental results in B. subtilisand S. pneumoniae. Research partially supported by the James S McDonnell Foundation grant No. 220020321 and by HFSP grant No. RGY0084/2011.

  17. Bacterial endocarditis prophylaxis.

    Science.gov (United States)

    Blanco-Carrión, Andrés

    2004-01-01

    Bacterial endocarditis (BE) is a disease resulting from the association of morphological alterations of the heart and bacteraemia originating from different sources that at times can be indiscernible (infectious endocarditis). It is classified on the basis of the morphological alteration involved, depending on the clinical manifestations and course of illness, which varies according to the causative microorganism and host conditions (for example, it is characteristic in I.V. drug users). The most common microorganisms involved are: Streptococcus viridans (55%), Staphylococcus aureus (30%), Enterococcus (6%) and HACEK bacteria (corresponding to the initials: Haemophilus, Actinobacillus, Cardiobacterium, Eikenella and Kingella), although on occasions it can also be caused by fungi. The oral microbiological flora plays a very important role in the aetiopathogenesis of BE, given that the condition may be of oral or dental origin. This paper will deal with the prevention of said bacteraemia. Prophylaxis will be undertaken using amoxicillin or clindamycin according to action protocols, with special emphasis placed on oral hygiene in patients with structural defects of the heart.

  18. Bacterial ferrous iron transport: the Feo system.

    Science.gov (United States)

    Lau, Cheryl K Y; Krewulak, Karla D; Vogel, Hans J

    2016-03-01

    To maintain iron homeostasis within the cell, bacteria have evolved various types of iron acquisition systems. Ferric iron (Fe(3+)) is the dominant species in an oxygenated environment, while ferrous iron (Fe(2+)) is more abundant under anaerobic conditions or at low pH. For organisms that must combat oxygen limitation for their everyday survival, pathways for the uptake of ferrous iron are essential. Several bacterial ferrous iron transport systems have been described; however, only the Feo system appears to be widely distributed and is exclusively dedicated to the transport of iron. In recent years, many studies have explored the role of the FeoB and FeoA proteins in ferrous iron transport and their contribution toward bacterial virulence. The three-dimensional structures for the Feo proteins have recently been determined and provide insight into the molecular details of the transport system. A highly select group of bacteria also express the FeoC protein from the same operon. This review will provide a comprehensive look at the structural and functional aspects of the Feo system. In addition, bioinformatics analyses of the feo operon and the Feo proteins have been performed to complement our understanding of this ubiquitous bacterial uptake system, providing a new outlook for future studies.

  19. [Bacterial vaginal fluor in intrauterine contraception].

    Science.gov (United States)

    Feichter, G E; Nohlen, M; Tauber, P F

    1979-11-01

    Vaginal swabs obtained from 100 IUD-users were examined bacteriologically. Fifty-one women had vaginal discharge and 49 women used as control group had no complaints originating either from the IUD or from the genital tract. In the group of IUD-users with vaginal discharge the number of bacterial isolates was higher and the cultures were more diversified. The nulliparous patients in this group exhibited more anaerobic cultures than the IUD-users without discharge. The significance of vaginal discharge in IUD-users is its function as a pool for pathogenic bacteria which may provoke and/or maintain inflammatory diseases of the female genital tract. IUD-users with vaginal discharge do therefore need not only bacteriologic diagnosis, but also consequent treatment of the discharge.

  20. The enzymes of bacterial census and censorship.

    Science.gov (United States)

    Fast, Walter; Tipton, Peter A

    2012-01-01

    N-Acyl-L-homoserine lactones (AHLs) are a major class of quorum-sensing signals used by Gram-negative bacteria to regulate gene expression in a population-dependent manner, thereby enabling group behavior. Enzymes capable of generating and catabolizing AHL signals are of significant interest for the study of microbial ecology and quorum-sensing pathways, for understanding the systems that bacteria have evolved to interact with small-molecule signals, and for their possible use in therapeutic and industrial applications. The recent structural and functional studies reviewed here provide a detailed insight into the chemistry and enzymology of bacterial communication.

  1. Group Grammar

    Science.gov (United States)

    Adams, Karen

    2015-01-01

    In this article Karen Adams demonstrates how to incorporate group grammar techniques into a classroom activity. In the activity, students practice using the target grammar to do something they naturally enjoy: learning about each other.

  2. MUYANG GROUP

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ With its headquarters in the historic city of Yangzhou,Jiangsu Muyang Group Co.,Ltd has since its founding in 1967 grown into a well-known group corporation whose activities cover research&development.project design,manufacturing,installation and services in a multitude of industries including feed machinery and engineering,storage engineering,grain machinery and engineering,environmental protection,conveying equipment and automatic control systems.

  3. 南海瑞雷面波群速度层析成像及其地球动力学意义%Group velocity tomography of Rayleigh waves in South China Sea and its geodynamic implications

    Institute of Scientific and Technical Information of China (English)

    陈立; 薛梅; Le Khanh Phon; 杨挺

    2012-01-01

    complex geological structures. In this study, we give a 3D shear wave velocity structure of South China Sea deduced from surface wave tomography and analyze its geodynamic implications. Due to the newly deployed seismic stations in western and southern South China Sea, we have a better ray path coverage when using the single station method. This is especially true for the coastal region of southern China, where earthquakes occur less frequently and the newly added stations can increase the ray density in this region. We used earthquakes distributed on the periphery of South China Sea and collected earthquake data from 48 stations. We first calculated the group velocity dispersion curves of fundamental mode for Rayleigh waves with periods from 14 s to 130 s using multiple filter technique. Then we conducted subspace inversion to get group velocity distributions for different periods in the region. Finally, on the basis of the relationship between shear wave velocity and group velocity under certain layer structure of the Earth, we obtained the 3D shear wave structures in the form of depth slices and vertical profiles by using a damped least square algorithm. The results show: ①High velocities exist in sea basins where velocity image delineates the shape of sea basins: the high velocities in shallow parts may indicate oceanic characteristics of the sea basin crust, while high velocities in deeper parts may come from high velocity materials which remained after the formation of oceanic crust at expanding ocean ridge. The velocity differences among sea basins are consistent with their heat flow values as well as their ages. The high velocities disappear at depths greater than 60 km, and are replaced by a low-velocity zone in a certain depth range. Beneath the low-velocity zone, a NE-SW high-velocity belt is observed at a depth of 200 km, and may be related to the ancient subduction in this region. ②Surrounding the South China Sea, there are obvious high velocities

  4. Abelian groups

    CERN Document Server

    Fuchs, László

    2015-01-01

    Written by one of the subject’s foremost experts, this book focuses on the central developments and modern methods of the advanced theory of abelian groups, while remaining accessible, as an introduction and reference, to the non-specialist. It provides a coherent source for results scattered throughout the research literature with lots of new proofs. The presentation highlights major trends that have radically changed the modern character of the subject, in particular, the use of homological methods in the structure theory of various classes of abelian groups, and the use of advanced set-theoretical methods in the study of undecidability problems. The treatment of the latter trend includes Shelah’s seminal work on the undecidability in ZFC of Whitehead’s Problem; while the treatment of the former trend includes an extensive (but non-exhaustive) study of p-groups, torsion-free groups, mixed groups, and important classes of groups arising from ring theory. To prepare the reader to tackle these topics, th...

  5. Bacterial Communities: Interactions to Scale

    Directory of Open Access Journals (Sweden)

    Reed M. Stubbendieck

    2016-08-01

    Full Text Available In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities.

  6. Bacterial Chromosome Organization and Segregation

    OpenAIRE

    Toro, Esteban; Shapiro, Lucy

    2010-01-01

    Bacterial chromosomes are generally ∼1000 times longer than the cells in which they reside, and concurrent replication, segregation, and transcription/translation of this crowded mass of DNA poses a challenging organizational problem. Recent advances in cell-imaging technology with subdiffraction resolution have revealed that the bacterial nucleoid is reliably oriented and highly organized within the cell. Such organization is transmitted from one generation to the next by progressive segrega...

  7. Bacterial Protein-Tyrosine Kinases

    DEFF Research Database (Denmark)

    Shi, Lei; Kobir, Ahasanul; Jers, Carsten

    2010-01-01

    phosphorylation. Protein-tyrosine phosphorylation in bacteria is particular with respect to very low occupancy of phosphorylation sites in vivo; this has represented a major challenge for detection techniques. Only the recent breakthroughs in gel-free high resolution mass spectrometry allowed the systematic...... and highlighted their importance in bacterial physiology. Having no orthologues in Eukarya, BY-kinases are receiving a growing attention from the biomedical field, since they represent a particularly promising target for anti-bacterial drug design....

  8. Surface micropattern limits bacterial contamination

    OpenAIRE

    Mann, Ethan E.; Manna, Dipankar; Mettetal, Michael R; May, Rhea M.; Dannemiller, Elisa M; Chung, Kenneth K.; Brennan, Anthony B; Reddy, Shravanthi T

    2014-01-01

    Background Bacterial surface contamination contributes to transmission of nosocomial infections. Chemical cleansers used to control surface contamination are often toxic and incorrectly implemented. Additional non-toxic strategies should be combined with regular cleanings to mitigate risks of human error and further decrease rates of nosocomial infections. The Sharklet micropattern (MP), inspired by shark skin, is an effective tool for reducing bacterial load on surfaces without toxic additiv...

  9. Bacterial cellulose/boehmite composites

    Energy Technology Data Exchange (ETDEWEB)

    Salvi, Denise T.B. de; Barud, Hernane S.; Messaddeq, Younes; Ribeiro, Sidney J.L. [Universidade Estadual Paulista Julio de Mesquita Filho. UNESP. Instituto de Quimica de Araraquara, SP (Brazil); Caiut, Jose Mauricio A. [Universidade de Sao Paulo. Departamento de Quimica - FFCLRP/USP, Ribeirao Preto, SP (Brazil)

    2011-07-01

    Composites based on bacterial cellulose membranes and boehmite were obtained. SEM results indicate that the bacterial cellulose (BC) membranes are totally covered by boehmite and obtained XRD patterns suggest structural changes due to this boehmite addition. Thermal stability is accessed through TG curves and is dependent on boehmite content. Transparency is high comparing to pure BC as can be seen through UV-vis absorption spectroscopy. (author)

  10. The most important marine bacterial toxins; a review

    Directory of Open Access Journals (Sweden)

    Akram Najafi

    2016-07-01

    Full Text Available Background: Bacterial toxins are toxic compounds which are produced in order to present microbial pathogenicity or to combat with the host immune system response. There is a cumulating evidence indicating bacterial origin for marine toxins such as tetrodotoxin, palytoxin, neosurugatoxin, etc. The most important marine toxins produced by different marine bacteria, their origin, structure and mechanisms of action were evaluated in a systematic review. Materials & Methods: Marine bacteria, marine bacterial toxins, and their mechanisms of action and structure were keywords for a comprehensive search in online databases including Pubmed, Science Direct, Google Scholar and Scirus. A total of 120 papers were evaluated, however, by omitting similar reports, 103 papers were included in the study. Results: The most of marine bacterial toxins are classified in one of the following groups: neurotoxins, hepatotoxins and cytotoxins. These toxins have distinct mechanisms of action including blocking of sodium channels in nerve cells, functioning as agonists of acetylcholine receptors, inhibiting of membrane pumps, the inhibition of protein phosphatases 1 and 2A types' enzyme activities and inhibiting of protein synthesis. Conclusion: The clarification of the marine bacterial toxins structures and their mechanisms of action may be helpful for novel drug design, therapeutic measures and to overcome against bacterial pathogenicity.

  11. Fermented liquid feed enhances bacterial diversity in piglet intestine.

    Science.gov (United States)

    Tajima, Kiyoshi; Ohmori, Hideyuki; Aminov, Rustam I; Kobashi, Yuri; Kawashima, Tomoyuki

    2010-02-01

    Because of limitations imposed on the antibiotic use in animal industry, there is a need for alternatives to maintain the efficiency of production. One of them may be the use of fermented liquid feed (FLF) but how it affects gut ecology is poorly understood. We investigated the effect of three diets, standard dry feed (control), dry feed supplemented with antibiotics, and fermented liquid feed (FLF, fermented with Lactobacillus plantarum), on gut bacterial diversity in piglets. The structure of the ileal and caecal communities was estimated by sequencing the SSU rRNA gene libraries. Antibiotic-supplemented feed slightly increased bacterial diversity in the ileum but reduced it in the caecum while in FLF-fed animals bacterial diversity was elevated. The majority of bacterial sequences in the ileum of all three groups belonged to lactobacilli (92-98%). In the caecum the lactobacilli were still dominant in control and antibiotic-fed animals (59% and 64% of total bacterial sequences, respectively) but in FLF-fed animals they fell to 31% with the concomitant increase in the Firmicutes diversity represented by the Dorea, Coprococcus, Roseburia and Faecalibacterium genera. Thus FLF affects the gut ecology in a different way than antibiotics and contributes to the enhanced bacterial diversity in the gastrointestinal tract.

  12. Algebraic Groups

    DEFF Research Database (Denmark)

    2007-01-01

    of algebraic groups (in a broad sense) has seen important developments in several directions, also related to representation theory and algebraic geometry. The workshop aimed at presenting some of these developments in order to make them accessible to a "general audience" of algebraic group......-theorists, and to stimulate contacts between participants. Each of the first four days was dedicated to one area of research that has recently seen decisive progress: \\begin{itemize} \\item structure and classification of wonderful varieties, \\item finite reductive groups and character sheaves, \\item quantum cohomology...... of homogeneous varieties, \\item representation categories and their connections to orbits and flag varieties. \\end{itemize} The first three days started with survey talks that will help to make the subject accessible to the next generation. The talks on the last day introduced to several recent advances...

  13. Group Anonymity

    CERN Document Server

    Chertov, Oleg; 10.1007/978-3-642-14058-7_61

    2010-01-01

    In recent years the amount of digital data in the world has risen immensely. But, the more information exists, the greater is the possibility of its unwanted disclosure. Thus, the data privacy protection has become a pressing problem of the present time. The task of individual privacy-preserving is being thoroughly studied nowadays. At the same time, the problem of statistical disclosure control for collective (or group) data is still open. In this paper we propose an effective and relatively simple (wavelet-based) way to provide group anonymity in collective data. We also provide a real-life example to illustrate the method.

  14. Informal groups

    NARCIS (Netherlands)

    E. van den Berg; P. van Houwelingen; J. de Hart

    2011-01-01

    Original title: Informele groepen Going out running with a group of friends, rather than joining an official sports club. Individuals who decide to take action themselves rather than giving money to good causes. Maintaining contact with others not as a member of an association, but through an Inter

  15. Diversity of Bacterial Communities of Fitness Center Surfaces in a U.S. Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Nabanita Mukherjee

    2014-12-01

    Full Text Available Public fitness centers and exercise facilities have been implicated as possible sources for transmitting community-acquired bacterial infections. However, the overall diversity of the bacterial community residing on the surfaces in these indoor environments is still unknown. In this study, we investigated the overall bacterial ecology of selected fitness centers in a metropolitan area (Memphis, TN, USA utilizing culture-independent pyrosequencing of the 16S rRNA genes. Samples were collected from the skin-contact surfaces (e.g., exercise instruments, floor mats, handrails, etc. within fitness centers. Taxonomical composition revealed the abundance of Firmicutes phyla, followed by Proteobacter and Actinobacteria, with a total of 17 bacterial families and 25 bacterial genera. Most of these bacterial genera are of human and environmental origin (including, air, dust, soil, and water. Additionally, we found the presence of some pathogenic or potential pathogenic bacterial genera including Salmonella, Staphylococcus, Klebsiella, and Micrococcus. Staphylococcus was found to be the most prevalent genus. Presence of viable forms of these pathogens elevates risk of exposure of any susceptible individuals. Several factors (including personal hygiene, surface cleaning and disinfection schedules of the facilities may be the reasons for the rich bacterial diversity found in this study. The current finding underscores the need to increase public awareness on the importance of personal hygiene and sanitation for public gym users.

  16. Presence of a polymicrobial endometrial biofilm in patients with bacterial vaginosis.

    Directory of Open Access Journals (Sweden)

    Alexander Swidsinski

    Full Text Available OBJECTIVE: To assess whether the bacterial vaginosis biofilm extends into the upper female genital tract. STUDY DESIGN: Endometrial samples obtained during curettage and fallopian tube samples obtained during salpingectomy were collected. Endometrial and fallopian tube samples were analyzed for the presence of bacteria with fluorescence-in-situ-hybridisation (FISH analysis with probes targeting bacterial vaginosis-associated and other bacteria. RESULTS: A structured polymicrobial Gardnerella vaginalis biofilm could be detected in part of the endometrial and fallopian tube specimens. Women with bacterial vaginosis had a 50.0% (95% CI 24.0-76.0 risk of presenting with an endometrial Gardnerella vaginalis biofilm. Pregnancy (AOR  = 41.5, 95% CI 5.0-341.9, p<0.001 and the presence of bacterial vaginosis (AOR  = 23.2, 95% CI 2.6-205.9, p<0.001 were highly predictive of the presence of uterine or fallopian bacterial colonisation when compared to non-pregnant women without bacterial vaginosis. CONCLUSION: Bacterial vaginosis is frequently associated with the presence of a structured polymicrobial Gardnerella vaginalis biofilm attached to the endometrium. This may have major implications for our understanding of the pathogenesis of adverse pregnancy outcome in association with bacterial vaginosis.

  17. Do bacterial vaginosis and chlamydial infection affect serum cytokine level?

    Directory of Open Access Journals (Sweden)

    Bogavac Mirjana

    2010-01-01

    Full Text Available Introduction. Serbia is the country with extremely low birth rate and a relatively high percentage of preterm deliveries (8%. With this in mind, discovering new diagnostic methods that could be used for the prediction of preterm delivery is of great importance. In this study we tried to determine whether bacterial vaginosis and chlamydial infection could provoke preterm delivery by activation of systemic cytokine network. Objective. The aim of this study was to determine serum levels of proinflammatory cytokines (IL-1β, IL-8, IFN-γ, IL-6 and TNF-α in pregnant women with symptoms of preterm delivery and to make correlation between these parameters and the presence of bacterial vaginosis or chlamydial infection. Method. In the serum of 35 pregnant women, which were divided in groups according to the presence or absence of bacterial vaginosis and chlamydial infection, commercial ELISA tests for proinflammatory cytokines were performed. Results. The serum level of IFN-γ was significantly increased in pregnant women having chlamydial infection, as well as the level of IL-1β in women with bacterial vaginosis. The levels of TNF-α, IL-6 and IL-8 were not significantly different between the investigated groups. Conclusion. The preliminary results obtained in this research point out the possibility that not only intrauterine or systemic infections, but also bacterial vaginosis and chlamydial infection can cause a partial activation of systemic cytokine network and contribute to the occurrence of preterm delivery.

  18. Microbial small talk: volatiles in fungal-bacterial interactions

    NARCIS (Netherlands)

    Schmidt, Ruth; Etalo, D.N.; de Jager, V.C.L.; Gerards, S.; Zweers, H.; De Boer, W.; Garbeva, P.V.

    2016-01-01

    There is increasing evidence that volatile organic compounds (VOCs) play an important role in the interactions between fungi and bacteria, two major groups of soil inhabiting microorganisms. Yet, most of the research has been focused on effects of bacterial volatiles on suppression of plant pathogen

  19. Surface display of proteins by Gram-negative bacterial autotransporters

    Directory of Open Access Journals (Sweden)

    Mourez Michael

    2006-06-01

    Full Text Available Abstract Expressing proteins of interest as fusions to proteins of the bacterial envelope is a powerful technique with many biotechnological and medical applications. Autotransporters have recently emerged as a good tool for bacterial surface display. These proteins are composed of an N-terminal signal peptide, followed by a passenger domain and a translocator domain that mediates the outer membrane translocation of the passenger. The natural passenger domain of autotransporters can be replaced by heterologous proteins that become displayed at the bacterial surface by the translocator domain. The simplicity and versatility of this system has made it very attractive and it has been used to display functional enzymes, vaccine antigens as well as polypeptides libraries. The recent advances in the study of the translocation mechanism of autotransporters have raised several controversial issues with implications for their use as display systems. These issues include the requirement for the displayed polypeptides to remain in a translocation-competent state in the periplasm, the requirement for specific signal sequences and "autochaperone" domains, and the influence of the genetic background of the expression host strain. It is therefore important to better understand the mechanism of translocation of autotransporters in order to employ them to their full potential. This review will focus on the recent advances in the study of the translocation mechanism of autotransporters and describe practical considerations regarding their use for bacterial surface display.

  20. The Human Vaginal Bacterial Biota and Bacterial Vaginosis

    Directory of Open Access Journals (Sweden)

    Sujatha Srinivasan

    2008-01-01

    Full Text Available The bacterial biota of the human vagina can have a profound impact on the health of women and their neonates. Changes in the vaginal microbiota have been associated with several adverse health outcomes including premature birth, pelvic inflammatory disease, and acquisition of HIV infection. Cultivation-independent molecular methods have provided new insights regarding bacterial diversity in this important niche, particularly in women with the common condition bacterial vaginosis (BV. PCR methods have shown that women with BV have complex communities of vaginal bacteria that include many fastidious species, particularly from the phyla Bacteroidetes and Actinobacteria. Healthy women are mostly colonized with lactobacilli such as Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus iners, though a variety of other bacteria may be present. The microbiology of BV is heterogeneous. The presence of Gardnerella vaginalis and Atopobium vaginae coating the vaginal epithelium in some subjects with BV suggests that biofilms may contribute to this condition.

  1. Bacterial vaginosis in the context of lichen sclerosus in a prepubertal girl.

    Science.gov (United States)

    Feito-Rodríguez, Marta; Noguera-Morel, Lucero; Casas-Rivero, José; García-Rodríguez, Julio; de Lucas-Laguna, Raul

    2014-01-01

    Group A beta-hemolytic streptococcus cause most vulvovaginal infections seen in prepubertal girls. Bacterial vaginosis is a common cause of abnormal vaginal discharge in women of childbearing age but is rare in children. Data are insufficient to suggest that bacterial vaginosis is an exclusively sexually transmitted disease. We report a 10-year-old girl with no history or suspicion of sexual abuse who developed bacterial vaginosis in the context of a lichen sclerosus being treated with tacrolimus ointment. Secondary bacterial infection in lichen sclerosus is uncommon. We speculate that the immunosuppressive effect of topical tacrolimus could have triggered the infection.

  2. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    The CMS Communications Group, established at the start of 2010, has been busy in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure There are now 55 CMS Centres worldwide that are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin, is the centre of the CMS offline and computing operations, hosting dedicated analysis efforts such as during the CMS Heavy Ion lead-lead running. With a majority of CMS sub-detectors now operating in a “shifterless” mode, many monitoring operations are now routinely performed from there, rather than in the main Control Room at P5. The CMS Communications Group, CERN IT and the EVO team are providing excellent videoconferencing support for the rapidly-increasing number of CMS meetings. In parallel, CERN IT and ...

  3. Group play

    DEFF Research Database (Denmark)

    Tychsen, Anders; Hitchens, Michael; Brolund, Thea

    2008-01-01

    of group dynamics, the influence of the fictional game characters and the comparative play experience between the two formats. The results indicate that group dynamics and the relationship between the players and their digital characters, are integral to the quality of the gaming experience in multiplayer......Role-playing games (RPGs) are a well-known game form, existing in a number of formats, including tabletop, live action, and various digital forms. Despite their popularity, empirical studies of these games are relatively rare. In particular there have been few examinations of the effects...... of the various formats used by RPGs on the gaming experience. This article presents the results of an empirical study, examining how multi-player tabletop RPGs are affected as they are ported to the digital medium. Issues examined include the use of disposition assessments to predict play experience, the effect...

  4. Lego Group

    DEFF Research Database (Denmark)

    Møller Larsen, Marcus; Pedersen, Torben; Slepniov, Dmitrij

    2010-01-01

    The last years’ rather adventurous journey from 2004 to 2009 had taught the fifth-largest toy-maker in the world - the LEGO Group - the importance of managing the global supply chain effectively. In order to survive the largest internal financial crisis in its roughly 70 years of existence......, the management had, among many initiatives, decided to offshore and outsource a major chunk of its production to Flextronics. In this pursuit of rapid cost-cutting sourcing advantages, the LEGO Group planned to license out as much as 80 per cent of its production besides closing down major parts...... of the production in high cost countries. Confident with the prospects of the new partnership, the company signed a long-term contract with Flextronics. This decision eventually proved itself to have been too hasty, however. Merely three years after the contracts were signed, LEGO management announced that it would...

  5. Bacterial disease management: challenges, experience, innovation and future prospects: Challenges in Bacterial Molecular Plant Pathology.

    Science.gov (United States)

    Sundin, George W; Castiblanco, Luisa F; Yuan, Xiaochen; Zeng, Quan; Yang, Ching-Hong

    2016-12-01

    only identify optimal targets in the pathogens, but also optimal seasonal timings for deployment. Host resistance to effectors must be exploited, carefully and correctly. Are there other candidate genes that could be targeted in transgenic approaches? How can new technologies (CRISPR, TALEN, etc.) be most effectively used to add sustainable disease resistance to existing commercially desirable plant cultivars? We need an insider's perspective on the management of systemic pathogens. In addition to host resistance or reduced sensitivity, are there other methods that can be used to target these pathogen groups? Biological systems are variable. Can biological control strategies be improved for bacterial disease management and be made more predictable in function? The answers to the research foci outlined above are not all available, as will become apparent in this article, but we are heading in the right direction. In this article, we summarize the contributions from past experiences in bacterial disease management, and also describe how advances in bacterial genetics, genomics and host-pathogen interactions are informing novel strategies in virulence inhibition and in host resistance. We also outline potential innovations that could be exploited as the pressures to maximize a safe and productive food supply continue to become more numerous and more complex.

  6. New Treatments for Bacterial Keratitis

    Directory of Open Access Journals (Sweden)

    Raymond L. M. Wong

    2012-01-01

    Full Text Available Purpose. To review the newer treatments for bacterial keratitis. Data Sources. PubMed literature search up to April 2012. Study Selection. Key words used for literature search: “infectious keratitis”, “microbial keratitis”, “infective keratitis”, “new treatments for infectious keratitis”, “fourth generation fluoroquinolones”, “moxifloxacin”, “gatifloxacin”, “collagen cross-linking”, and “photodynamic therapy”. Data Extraction. Over 2400 articles were retrieved. Large scale studies or publications at more recent dates were selected. Data Synthesis. Broad spectrum antibiotics have been the main stay of treatment for bacterial keratitis but with the emergence of bacterial resistance; there is a need for newer antimicrobial agents and treatment methods. Fourth-generation fluoroquinolones and corneal collagen cross-linking are amongst the new treatments. In vitro studies and prospective clinical trials have shown that fourth-generation fluoroquinolones are better than the older generation fluoroquinolones and are as potent as combined fortified antibiotics against common pathogens that cause bacterial keratitis. Collagen cross-linking was shown to improve healing of infectious corneal ulcer in treatment-resistant cases or as an adjunct to antibiotics treatment. Conclusion. Fourth-generation fluoroquinolones are good alternatives to standard treatment of bacterial keratitis using combined fortified topical antibiotics. Collagen cross-linking may be considered in treatment-resistant infectious keratitis or as an adjunct to antibiotics therapy.

  7. Bacterial carbonatogenesis; La carbonatogenese bacterienne

    Energy Technology Data Exchange (ETDEWEB)

    Castanier, S. [Angers Univ., 49 (France). Faculte des Sciences; Le Metayer-Levrel, G.; Perthuisot, J.P. [Nantes Univ., 44 (France). Laboratoire de Biogeologie, Faculte des Sciences et des Techniques

    1998-12-31

    Several series of experiments in the laboratory as well as in natural conditions teach that the production of carbonate particles by heterotrophic bacteria follows different ways. The `passive` carbonatogenesis is generated by modifications of the medium that lead to the accumulation of carbonate and bicarbonate ions and to the precipitation of solid particles. The `active` carbonatogenesis is independent of the metabolic pathways. The carbonate particles are produced by ionic exchanges through the cell membrane following still poorly known mechanisms. Carbonatogenesis appears to be the response of heterotrophic bacterial communities to an enrichment of the milieu in organic matter. The active carbonatogenesis seems to start first. It is followed by the passive one which induces the growth of initially produced particles. The yield of heterotrophic bacterial carbonatogenesis and the amounts of solid carbonates production by bacteria are potentially very high as compared to autotrophic or chemical sedimentation from marine, paralic or continental waters. Furthermore, the bacterial processes are environmentally very ubiquitous; they just require organic matter enrichment. Thus, apart from purely evaporite and autotrophic ones, all Ca and/or Mg carbonates must be considered as from heterotrophic bacterial origin. By the way, the carbon of carbonates comes from primary organic matter. Such considerations ask questions about some interpretations from isotopic data on carbonates. Finally, bacterial heterotrophic carbonatogenesis appears as a fundamental phase in the relationships between atmosphere and lithosphere and in the geo-biological evolution of Earth. (author) 43 refs.

  8. The hematology of bacterial infections in premature infants.

    Science.gov (United States)

    Zipursky, A; Palko, J; Milner, R; Akenzua, G I

    1976-06-01

    A series of premature infants was studied for the presence of bacterial infection. On the basis of clinical evidence and bacteriological studies, they were divided into three groups in which sepsis was considered to be proven, possible, or unlikely. Band neutrophil counts were elevated most frequently in the "sepsis-proven" group and the elevation occurred usually within 24 hours of onset of signs of disease. Qualitative changes in neutrophils (Döhle bodies, toxic granulation, and vacuolization) were more frequent in the sepsis-proven group and, together with the band count, provided valuable techniques for the diagnosis of bacterial infections. Thrombocytopenia occurred frequently in the sepsis-proven group and seemed to result from increased utilization or destruction of platelets rather than failure of production. In such cases, evidence of intravascular coagulation was minimal and it was concluded that thrombocytopenia had resulted from a direct effect of the bacteria or its products on platelets and/or endothelium.

  9. Bacterial cellulose and bacterial cellulose/polycaprolactone composite as tissue substitutes in rabbits' cornea

    Directory of Open Access Journals (Sweden)

    Rodrigo V. Sepúlveda

    Full Text Available ABSTRACT: In order to test the performance of bacterial cellulose/polycaprolactone composite (BC/PCL and pure bacterial cellulose (BC as tissue substitutes in rabbits' cornea, a superficial ulcer containing 5mm in diameter and 0.2mm deep was made in the right cornea of 36 rabbits, then a interlayer pocket was created from the basis of this ulcer. Twelve rabbits received BC/PCL membrane and 12 were treated with BC membranes, both membranes with 8mm in diameter. The remaining rabbits received no membrane constituting the control group. The animals were clinically followed up for 45 days. Three animals of each group were euthanized at three, seven, 21, and 45 days after implantation for histological examination of the cornea along with the implant. Clinical observation revealed signs of moderate inflammatory process, decreasing from day 20th in the implanted groups. Histology showed absence of epithelium on the membranes, fibroplasia close to the implants, lymph inflammatory infiltrate with giant cells, collagen disorganization, with a predominance of immature collagen fibers in both groups with implants. Although inflammatory response is acceptable, the membranes used does not satisfactorily played the role of tissue substitute for the cornea during the study period.

  10. Changes in soil bacterial community structure with increasing disturbance frequency.

    Science.gov (United States)

    Kim, Mincheol; Heo, Eunjung; Kang, Hojeong; Adams, Jonathan

    2013-07-01

    Little is known of the responsiveness of soil bacterial community structure to disturbance. In this study, we subjected a soil microcosm to physical disturbance, sterilizing 90 % of the soil volume each time, at a range of frequencies. We analysed the bacterial community structure using 454 pyrosequencing of the 16S rRNA gene. Bacterial diversity was found to decline with the increasing disturbance frequencies. Total bacterial abundance was, however, higher at intermediate and high disturbance frequencies, compared to low and no-disturbance treatments. Changing disturbance frequency also led to changes in community composition, with changes in overall species composition and some groups becoming abundant at the expense of others. Some phylogenetic groups were found to be relatively more disturbance-sensitive or tolerant than others. With increasing disturbance frequency, phylogenetic species variability (an index of community composition) itself became more variable from one sample to another, suggesting a greater role of chance in community composition. Compared to the tightly clustered community of the original undisturbed soil, in all the aged disturbed soils the lists of most abundant operational taxonomic units (OTUs) in each replicate were very different, suggesting a possible role of stochasticity in resource colonization and exploitation in the aged and disturbed soils. For example, colonization may be affected by whichever localized concentrations of bacterial populations happen to survive the last disturbance and be reincorporated in abundance into each pot. Overall, it appears that the soil bacterial community is very sensitive to physical disturbance, losing diversity, and that certain groups have identifiable 'high disturbance' vs. 'low disturbance' niches.

  11. Group Connections: Whole Group Teaching.

    Science.gov (United States)

    Griffiths, Dorothy

    2002-01-01

    A learner-centered approach to adult group instruction involved learners in investigating 20th-century events. The approach allowed learners to concentrate on different activities according to their abilities and gave them opportunities to develop basic skills and practice teamwork. (SK)

  12. Co-acclimation of bacterial communities under stresses of hydrocarbons with different structures

    Science.gov (United States)

    Wang, Hui; Wang, Bin; Dong, Wenwen; Hu, Xiaoke

    2016-10-01

    Crude oil is a complex mixture of hydrocarbons with different structures; its components vary in bioavailability and toxicity. It is important to understand how bacterial communities response to different hydrocarbons and their co-acclimation in the process of degradation. In this study, microcosms with the addition of structurally different hydrocarbons were setup to investigate the successions of bacterial communities and the interactions between different bacterial taxa. Hydrocarbons were effectively degraded in all microcosms after 40 days. High-throughput sequencing offered a great quantity of data for analyzing successions of bacterial communities. The results indicated that the bacterial communities responded dramatically different to various hydrocarbons. KEGG database and PICRUSt were applied to predict functions of individual bacterial taxa and networks were constructed to analyze co-acclimations between functional bacterial groups. Almost all functional genes catalyzing degradation of different hydrocarbons were predicted in bacterial communities. Most of bacterial taxa were believed to conduct biodegradation processes via interactions with each other. This study addressed a few investigated area of bacterial community responses to structurally different organic pollutants and their co-acclimation and interactions in the process of biodegradation. The study could provide useful information to guide the bioremediation of crude oil pollution.

  13. Mechanism and site of inhibition of AMPA receptors: substitution of one and two methyl groups at the 4-aminophenyl ring of 2,3-benzodiazepine and implications in the "E" site.

    Science.gov (United States)

    Wang, Congzhou; Wu, Andrew; Shen, Yu-Chuan; Ettari, Roberta; Grasso, Silvana; Niu, Li

    2015-08-19

    2,3-Benzodiazepines are a well-known group of compounds for their potential antagonism against AMPA receptors. It has been previously reported that the inhibitory effect of 2,3-benzodiazepine derivatives with a 7,8-ethylenedioxy moiety can be enhanced by simply adding a chlorine atom at position 3 of the 4-aminophenyl ring. Here we report that adding a methyl group at position 3 on the 4-aminophenyl ring, termed as BDZ-11-7, can similarly enhance the inhibitory activity, as compared with the unsubstituted one or BDZ-11-2. Our kinetic studies have shown that BDZ-11-7 is a noncompetitive antagonist of GluA2Q homomeric receptors and prefers to inhibit the closed-channel state. However, adding another methyl group at position 5 on the 4-aminophenyl ring, termed as BDZ-11-6, fails to yield extra inhibition on GluA2Q receptors. Instead, BDZ-11-6 exhibits a diminished inhibition of GluA2Q. Site interaction test indicates the two compounds, BDZ-11-6 and BDZ-11-7, bind to the same site on GluA2Q, which is also the binding site for their prototype, BDZ-11-2. Based on the results from this and our earlier studies, we propose that the binding site that accommodates the 4-aminophenyl ring must contain two interactive points, with one preferring polar groups like chlorine and the other preferring nonpolar groups such as a methyl group. Either adding a chlorine or a methyl group may enhance the inhibitory activity of 2,3-benzodiazepine derivatives with a 7,8-ethylenedioxy moiety. Adding any two of the same group on positions 3 and 5 of the 4-aminophenyl ring, however, significantly reduces the interaction between these 2,3-benzodiazepines and their binding site, because one group is always repelled by one interactive point. We predict therefore that adding a chlorine atom at position 3 and a methyl group at position 5 of the 4-aminophenyl ring of 2,3-benzodiazepine derivatives with a 7,8-ethylenedioxy moiety may produce a new compound that is more potent.

  14. Zircon U-Pb and Lu-Hf isotopic and whole-rock geochemical constraints on the Lanhe and Heichashan Groups: Implications for the Paleoproterozoic tectonic basin evolution of the Lüliang Complex

    Science.gov (United States)

    Liu, Chaohui; Zhao, Guochun; Liu, Fulai; Shi, Jianrong; Ji, Lei; Liu, Pinghua; Yang, Hong; Liu, Lishuang; Wang, Wei; Tian, Zhonghua

    2016-10-01

    The Lüliang Complex is located at the western margin of the middle segment of the Trans-North China Orogen, along which the Western and Eastern Blocks collided to form the North China Craton. The complex mainly consists of metamorphosed granitic plutons and supracrustal rocks, of which the latter are subdivided into the Jiehekou, Lüliang, Yejishan, Lanhe and Heichashan Groups. The Lanhe Group is composed of meta-conglomerates, quartzites, and phyllites with minor meta-basalts, whereas the Heichashan Group consists of molasse-like meta-conglomerates and coarse-grained quartzites. Geochemistry of the Yejishan meta-sedimentary rocks indicates weak source weathering and dominantly chemical immature features, whereas the Lanhe and Heichashan samples display opposite features. U-Pb ages of detrital zircons from the Lanhe Groups yield four age peaks at ~ 2180 Ma, ~ 2370 Ma, ~ 2520 Ma and ~ 2700 Ma. The former three peaks coincide with ages of the Chijianling-Guandishan TTG gneisses (2199-2151 Ma) and meta-volcanic rocks from the Lüliang and Yejishan Groups (2213-2156 Ma), age of the Gaijiazhuang porphyritic gneisses (2375-2364 Ma) and age of the Yunzhongshan TTG gneisses (2499 Ma) respectively, whereas detrital zircons forming the oldest age peak were most likely derived from the early Neoarchean crust of the Eastern Block. For the Heichashan Group, the dominant 2.2-2.0 Ga detrital zircons were probably recycled from the underlying Jiehekou Group and the minority is directly derived from the early Paleoproterozoic granitoids in the Lüliang Complex. The youngest detrital zircon age peaks of ~ 2.17 Ga and ~ 1.82 Ga place maximum depositional ages on the Lanhe and Heichashan Groups respectively, whereas the local 1.81-1.79 Ga massive granites place constraint on their minimum depositional ages. Taking into account the lithostratigraphic features, provenance and formation ages, we suggest that the Lanhe Group formed in a shrinked remnant back-arc basin and the Heichashan

  15. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2010-01-01

    The CMS Communications Group, established at the start of 2010, has been strengthening the activities in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure The Communications Group has invested a lot of effort to support the operations needs of CMS. Hence, the CMS Centres where physicists work on remote CMS shifts, Data Quality Monitoring, and Data Analysis are running very smoothly. There are now 55 CMS Centres worldwide, up from just 16 at the start of CMS data-taking. The latest to join are Imperial College London, the University of Iowa, and the Università di Napoli. The CMS Centre@CERN in Meyrin, which is now full repaired after the major flooding at the beginning of the year, has been at the centre of CMS offline and computing operations, most recently hosting a large fraction of the CMS Heavy Ion community during the lead-lead run. A number of sub-detector shifts can now take pla...

  16. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    The CMS Communications Group has been busy in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure The 55 CMS Centres worldwide are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin, is the centre of the CMS Offline and Computing operations, and a number of subdetector shifts can now take place there, rather than in the main Control Room at P5. A new CMS meeting room has been equipped for videoconferencing in building 42, next to building 40. Our building 28 meeting room and the facilities at P5 will be refurbished soon and plans are underway to steadily upgrade the ageing equipment in all 15 CMS meeting rooms at CERN. The CMS evaluation of the Vidyo tool indicates that it is not yet ready to be considered as a potential replacement for EVO. The Communications Group provides the CMS-TV (web) cha...

  17. Cerebrospinal fluid lactate dehydrogenase isoenzymes in children with bacterial and aseptic meningitis.

    Science.gov (United States)

    Nussinovitch, Moshe; Finkelstein, Yaron; Elishkevitz, Keren Politi; Volovitz, Benjamin; Harel, Daniella; Klinger, Gil; Razon, Yaron; Nussinovitch, Udi; Nussinovitch, Naomi

    2009-10-01

    Differentiation of bacterial from aseptic meningitis may be difficult. Our aim was to determine the pattern of distribution of lactate dehydrogenase (LDH) isoenzymes in the cerebrospinal fluid (CSF) of patients with bacterial and aseptic meningitis. One hundred and fifty-seven patients with suspected meningitis were enrolled in the study. They were divided into 3 groups according to the culture- or bacterial antigen assay-proven diagnosis and CSF findings: bacterial meningitis (n = 31), aseptic meningitis (n = 65), and non-meningitis (n = 61). Total LDH level and percentages of LDH isoenzymes in the CSF were measured in each patient. Each group showed a distinct LDH isoenzyme distribution pattern, with a statistically significant difference among the groups in the percentages of the various isoenzymes. Compared with the non-meningitis group, total LDH activity in the CSF was high in the aseptic meningitis group (49.82+/-35.59 U/L, P < 0.001) and exaggerated in the bacterial meningitis group (944.53+/-112.3 U/L, P < 0.001). Low LDH-2 levels were unique to bacterial meningitis (P < 0.01), whereas high LDH-3 levels were characteristic of aseptic meningitis (P < 0.05). Both groups had low levels of LDH-1 and high levels of LDH-4 and LDH-5. In conclusion, the LDH isoenzyme pattern may be of clinical diagnostic value in meningitis, particularly when culture results are pending.

  18. Temporally invariable bacterial community structure in the Arabian Sea oxygen minimum zone.

    Digital Repository Service at National Institute of Oceanography (India)

    Jain, A.; Bandekar, M.; Gomes, J.; Shenoy, D.M.; Meena, R.M.; Naik, H.; Khandeparkar, R.; Ramaiah, N.

    bacterial groups at the ASTS location. Linkage tree (LINKTREE) and canonical correspondence analysis (CCA) were performed to decipher the effect of environmental factors on the BC. From these analyses, it appears that DO and total organic carbon (TOC...

  19. Insights from twenty years of bacterial genome sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Jun, Se Ran [ORNL; Nookaew, Intawat [ORNL; Leuze, Michael Rex [ORNL; Ahn, Tae-Hyuk [ORNL; Karpinets, Tatiana V [ORNL; Lund, Ole [Technical University of Denmark; Kora, Guruprasad H [ORNL; Wassenaar, Trudy [Molecular Microbiology & Genomics Consultants, Zotzenheim, Germany; Poudel, Suresh [ORNL; Ussery, David W [ORNL

    2015-01-01

    Since the first two complete bacterial genome sequences were published in 1995, the science of bacteria has dramatically changed. Using third-generation DNA sequencing, it is possible to completely sequence a bacterial genome in a few hours and identify some types of methylation sites along the genome as well. Sequencing of bacterial genome sequences is now a standard procedure, and the information from tens of thousands of bacterial genomes has had a major impact on our views of the bacterial world. In this review, we explore a series of questions to highlight some insights that comparative genomics has produced. To date, there are genome sequences available from 50 different bacterial phyla and 11 different archaeal phyla. However, the distribution is quite skewed towards a few phyla that contain model organisms. But the breadth is continuing to improve, with projects dedicated to filling in less characterized taxonomic groups. The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system provides bacteria with immunity against viruses, which outnumber bacteria by tenfold. How fast can we go? Second-generation sequencing has produced a large number of draft genomes (close to 90 % of bacterial genomes in GenBank are currently not complete); third-generation sequencing can potentially produce a finished genome in a few hours, and at the same time provide methlylation sites along the entire chromosome. The diversity of bacterial communities is extensive as is evident from the genome sequences available from 50 different bacterial phyla and 11 different archaeal phyla. Genome sequencing can help in classifying an organism, and in the case where multiple genomes of the same species are available, it is possible to calculate the pan- and core genomes; comparison of more than 2000 Escherichia coli genomes finds an E. coli core genome of about 3100 gene families and a total of about 89,000 different gene families. Why do we care about bacterial genome

  20. A window of opportunity to control the bacterial pathogen Pseudomonas aeruginosa combining antibiotics and phages.

    Science.gov (United States)

    Torres-Barceló, Clara; Arias-Sánchez, Flor I; Vasse, Marie; Ramsayer, Johan; Kaltz, Oliver; Hochberg, Michael E

    2014-01-01

    The evolution of antibiotic resistance in bacteria is a global concern and the use of bacteriophages alone or in combined therapies is attracting increasing attention as an alternative. Evolutionary theory predicts that the probability of bacterial resistance to both phages and antibiotics will be lower than to either separately, due for example to fitness costs or to trade-offs between phage resistance mechanisms and bacterial growth. In this study, we assess the population impacts of either individual or combined treatments of a bacteriophage and streptomycin on the nosocomial pathogen Pseudomonas aeruginosa. We show that combining phage and antibiotics substantially increases bacterial control compared to either separately, and that there is a specific time delay in antibiotic introduction independent of antibiotic dose, that minimizes both bacterial density and resistance to either antibiotics or phage. These results have implications for optimal combined therapeutic approaches.

  1. Impact of disinfection on drinking water biofilm bacterial community.

    Science.gov (United States)

    Mi, Zilong; Dai, Yu; Xie, Shuguang; Chen, Chao; Zhang, Xiaojian

    2015-11-01

    Disinfectants are commonly applied to control the growth of microorganisms in drinking water distribution systems. However, the effect of disinfection on drinking water microbial community remains poorly understood. The present study investigated the impacts of different disinfectants (chlorine and chloramine) and dosages on biofilm bacterial community in bench-scale pipe section reactors. Illumina MiSeq sequencing illustrated that disinfection strategy could affect both bacterial diversity and community structure of drinking water biofilm. Proteobacteria tended to predominate in chloraminated drinking water biofilms, while Firmicutes in chlorinated and unchlorinated biofilms. The major proteobacterial groups were influenced by both disinfectant type and dosage. In addition, chloramination had a more profound impact on bacterial community than chlorination.

  2. Molecular mechanisms underlying bacterial persisters

    DEFF Research Database (Denmark)

    Maisonneuve, Etienne; Gerdes, Kenn

    2014-01-01

    All bacteria form persisters, cells that are multidrug tolerant and therefore able to survive antibiotic treatment. Due to the low frequencies of persisters in growing bacterial cultures and the complex underlying molecular mechanisms, the phenomenon has been challenging to study. However, recent...

  3. Bacterial Cytotoxins Target Rho GTPases

    Science.gov (United States)

    Schmidt, Gudula; Aktories, Klaus

    1998-06-01

    Low molecular mass GTPases of the Rho family, which are involved in the regulation of the actin cytoskeleton and in various signal transduction processes, are the eukaryotic targets of bacterial protein toxins. The toxins covalently modify Rho proteins by ADP ribosylation, glucosylation, and deamidation, thereby inactivating and activating the GTPases.

  4. Disease notes - Bacterial root rot

    Science.gov (United States)

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  5. Bacterial canker resistance in tomato

    NARCIS (Netherlands)

    Sen, Y.

    2014-01-01

    Clavibacter michiganensis subsp. michiganensis (Cmm) is the pathogen causing bacterial  canker in tomato. The disease was described for the first time in 1910 in Michigan, USA. Cmmis considered the most harmful bacteria threatening tomato. Disease transmission occurs via seed and symptoms becom

  6. Food irradiation and bacterial toxins

    Energy Technology Data Exchange (ETDEWEB)

    Tranter, H.S.; Modi, N.K.; Hambleton, P.; Melling, J.; Rose, S.; Stringer, M.F.

    1987-07-04

    The authors' findings indicate that irradiation confers no advantage over heat processing in respect of bacterial toxins (clostridium botulinum, neurotoxin A and staphylococcal enterotoxin A). It follows that irradiation at doses less than the ACINF recommended upper limit of 10 kGy could not be used to improve the ambient temperature shelf life on non-acid foods.

  7. Extracardiac manifestations of bacterial endocarditis.

    Science.gov (United States)

    Heffner, J E

    1979-08-01

    Bacterial endocarditis is an elusive disease that challenges clinicians' diagnostic capabilities. Because it can present with various combinations of extravalvular signs and symptoms, the underlying primary disease can go unnoticed.A review of the various extracardiac manifestations of bacterial endocarditis suggests three main patterns by which the valvular infection can be obscured. (1) A major clinical event may be so dramatic that subtle evidence of endocarditis is overlooked. The rupture of a mycotic aneurysm may simulate a subarachnoid hemorrhage from a congenital aneurysm. (2) The symptoms of bacterial endocarditis may be constitutional complaints easily attributable to a routine, trivial illness. Symptoms of low-grade fever, myalgias, back pain and anorexia may mimic a viral syndrome. (3) Endocarditis poses a difficult diagnostic dilemma when it generates constellations of findings that are classic for other disorders. Complaints of arthritis and arthralgias accompanied by hematuria and antinuclear antibody may suggest systemic lupus erythematosus; a renal biopsy study showing diffuse proliferative glomerulonephritis may support this diagnosis. The combination of fever, petechiae, altered mental status, thrombocytopenia, azotemia and anemia may promote the diagnosis of thrombotic thrombocytopenic purpura. When the protean guises of bacterial endocarditis create these clinical difficulties, errors in diagnosis occur and appropriate therapy is delayed. Keen awareness of the varied disease presentations will improve success in managing endocarditis by fostering rapid diagnosis and prompt therapy.

  8. Bacterial Diversity of Active Sludge in Wastewater Treatment Plant

    Science.gov (United States)

    Jiang, Xin; Ma, Mingchao; Li, Jun; Lu, Anhuai; Zhong, Zuoshen

    A bacterial 16S rDNA gene clone library was constructed to analyze the bacterial diversity of active sludge in Gaobeidian Wastewater Treatment Plant, Beijing. The results indicated that the bacterial diversity of active sludge was very high, and the clones could be divided into 5 different groups. The dominant bacterial community was proteobacteria, which accounted for 76.7%. The dominant succession of bacterial community were as follows: the β-proteobacteria (39.8%), the uncultured bacteria (22.33%), the γ-proteobacteria (20.15%), the α-proteobacteria (6.79%), and the σ-proteobacteria (4.85%). Nitrosomonas-like and Nitrospira-like bacteria, such as Nitrosomonas sp. (1.94%) and uncultured Nitrospirae bacterium (11.65%) were also detected, which have played important roles in ammonia and nitrite oxidisers in the system. However, they were only a little amount because of their slow growth and less competitive advantage than heterotrophic bacteria. Denitrifying bacteria like Thauera sp. was at a high percentage, which implies a strong denitrification ability; Roseomonas sp. was also detected in the clone library, which could be related to the degradation of organophosphorus pesticide.

  9. Genome engineering and gene expression control for bacterial strain development.

    Science.gov (United States)

    Song, Chan Woo; Lee, Joungmin; Lee, Sang Yup

    2015-01-01

    In recent years, a number of techniques and tools have been developed for genome engineering and gene expression control to achieve desired phenotypes of various bacteria. Here we review and discuss the recent advances in bacterial genome manipulation and gene expression control techniques, and their actual uses with accompanying examples. Genome engineering has been commonly performed based on homologous recombination. During such genome manipulation, the counterselection systems employing SacB or nucleases have mainly been used for the efficient selection of desired engineered strains. The recombineering technology enables simple and more rapid manipulation of the bacterial genome. The group II intron-mediated genome engineering technology is another option for some bacteria that are difficult to be engineered by homologous recombination. Due to the increasing demands on high-throughput screening of bacterial strains having the desired phenotypes, several multiplex genome engineering techniques have recently been developed and validated in some bacteria. Another approach to achieve desired bacterial phenotypes is the repression of target gene expression without the modification of genome sequences. This can be performed by expressing antisense RNA, small regulatory RNA, or CRISPR RNA to repress target gene expression at the transcriptional or translational level. All of these techniques allow efficient and rapid development and screening of bacterial strains having desired phenotypes, and more advanced techniques are expected to be seen.

  10. Bacterial Enzymes and Antibiotic Resistance- Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Maltz, Lauren [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-25

    By using protein crystallography and X-ray diffraction, structures of bacterial enzymes were solved to gain a better understanding of how enzymatic modification acts as an antibacterial resistance mechanism. Aminoglycoside phosphotransferases (APHs) are one of three aminoglycoside modifying enzymes that confer resistance to the aminoglycoside antibiotics via enzymatic modification, rendering many drugs obsolete. Specifically, the APH(2”) family vary in their substrate specificities and also in their preference for the phosphate donor (ADP versus GDP). By solving the structures of members of the APH(2”) family of enzymes, we can see how domain movements are important to their substrate specificity. Our structure of the ternary complex of APH(2”)-IIIa with GDP and kanamycin, when compared to the known structures of APH(2”)-IVa, reveals that there are real physical differences between these two enzymes, a structural finding that explains why the two enzymes differ in their preferences for certain aminoglycosides. Another important group of bacterial resistance enzymes are the Class D β-lactamases. Oxacillinase carbapenemases (OXAs) are part of this enzyme class and have begun to confer resistance to ‘last resort’ drugs, most notably carbapenems. Our structure of OXA-143 shows that the conformational flexibility of a conserved hydrophobic residue in the active site (Val130) serves to control the entry of a transient water molecule responsible for a key step in the enzyme’s mechanism. Our results provide insight into the structural mechanisms of these two different enzymes.

  11. Bacterial proteins pinpoint a single eukaryotic root.

    Science.gov (United States)

    Derelle, Romain; Torruella, Guifré; Klimeš, Vladimír; Brinkmann, Henner; Kim, Eunsoo; Vlček, Čestmír; Lang, B Franz; Eliáš, Marek

    2015-02-17

    The large phylogenetic distance separating eukaryotic genes and their archaeal orthologs has prevented identification of the position of the eukaryotic root in phylogenomic studies. Recently, an innovative approach has been proposed to circumvent this issue: the use as phylogenetic markers of proteins that have been transferred from bacterial donor sources to eukaryotes, after their emergence from Archaea. Using this approach, two recent independent studies have built phylogenomic datasets based on bacterial sequences, leading to different predictions of the eukaryotic root. Taking advantage of additional genome sequences from the jakobid Andalucia godoyi and the two known malawimonad species (Malawimonas jakobiformis and Malawimonas californiana), we reanalyzed these two phylogenomic datasets. We show that both datasets pinpoint the same phylogenetic position of the eukaryotic root that is between "Unikonta" and "Bikonta," with malawimonad and collodictyonid lineages on the Unikonta side of the root. Our results firmly indicate that (i) the supergroup Excavata is not monophyletic and (ii) the last common ancestor of eukaryotes was a biflagellate organism. Based on our results, we propose to rename the two major eukaryotic groups Unikonta and Bikonta as Opimoda and Diphoda, respectively.

  12. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2012-01-01

      Outreach and Education We are fortunate that our research has captured the public imagination, even though this inevitably puts us under the global media spotlight, as we saw with the Higgs seminar at CERN in December, which had 110,000 distinct webcast viewers. The media interest was huge with 71 media organisations registering to come to CERN to cover the Higgs seminar, which was followed by a press briefing with the DG and Spokespersons. This event resulted in about 2,000 generally positive stories in the global media. For this seminar, the CMS Communications Group prepared up-to-date news and public material, including links to the CMS results, animations and event displays [http://cern.ch/go/Ch8thttp://cern.ch/go/Ch8t]. There were 44,000 page-views on the CMS public website, with the Higgs news article being by far the most popular item. CMS event displays from iSpy are fast becoming the iconic media images, featuring on numerous major news outlets (BBC, CNN, MSN...) as well as in the sci...

  13. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2010-01-01

    The recently established CMS Communications Group, led by Lucas Taylor, has been busy in all three of its main are areas of responsibility: Communications Infrastructure, Information Systems, and Outreach and Education Communications Infrastructure The damage caused by the flooding of the CMS Centre@CERN on 21st December has been completely repaired and all systems are back in operation. Major repairs were made to the roofs, ceilings and one third of the floor had to be completely replaced. Throughout these works, the CMS Centre was kept operating and even hosted a major press event for first 7 TeV collisions, as described below. Incremental work behind the scenes is steadily improving the quality of the CMS communications infrastructure, particularly Webcasting, video conferencing, and meeting rooms at CERN. CERN/IT is also deploying a pilot service of a new videoconference tool called Vidyo, to assess whether it might provide an enhanced service at a lower cost, compared to the EVO tool currently in w...

  14. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    Communications Infrastructure The 55 CMS Centres worldwide are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin is particularly busy at the moment, hosting about 50 physicists taking part in the heavy-ion data-taking and analysis. Three new CMS meeting room will be equipped for videoconferencing in early 2012: 40/5B-08, 42/R-031, and 28/S-029. The CMS-TV service showing LHC Page 1, CMS Page 1, etc. (http://cmsdoc.cern.ch/cmscc/projector/index.jsp) is now also available for mobile devices: http://cern.ch/mcmstv. Figure 12: Screenshots of CMS-TV for mobile devices Information Systems CMS has a new web site: (http://cern.ch/cms) using a modern web Content Management System to ensure content and links are managed and updated easily and coherently. It covers all CMS sub-projects and groups, replacing the iCMS internal pages. It also incorporates the existing CMS public web site (http:/...

  15. [Bacterial identification methods in the microbiology laboratory].

    Science.gov (United States)

    Bou, Germán; Fernández-Olmos, Ana; García, Celia; Sáez-Nieto, Juan Antonio; Valdezate, Sylvia

    2011-10-01

    In order to identify the agent responsible of the infectious process and understanding the pathogenic/pathological implications, clinical course, and to implement an effective antimicrobial therapy, a mainstay in the practice of clinical microbiology is the allocation of species to a microbial isolation. In daily routine practice microbiology laboratory phenotypic techniques are applied to achieve this goal. However, they have some limitations that are seen more clearly for some kinds of microorganism. Molecular methods can circumvent some of these limitations, although its implementation is not universal. This is due to higher costs and the level of expertise required for thei implementation, so molecular methods are often centralized in reference laboratories and centers. Recently, proteomics-based methods made an important breakthrough in the field of diagnostic microbiology and will undoubtedly have a major impact on the future organization of the microbiology services. This paper is a short review of the most noteworthy aspects of the three bacterial identification methods described above used in microbiology laboratories.

  16. Persistence of antibiotic resistance in bacterial populations.

    Science.gov (United States)

    Andersson, Dan I; Hughes, Diarmaid

    2011-09-01

    Unfortunately for mankind, it is very likely that the antibiotic resistance problem we have generated during the last 60 years due to the extensive use and misuse of antibiotics is here to stay for the foreseeable future. This view is based on theoretical arguments, mathematical modeling, experiments and clinical interventions, suggesting that even if we could reduce antibiotic use, resistant clones would remain persistent and only slowly (if at all) be outcompeted by their susceptible relatives. In this review, we discuss the multitude of mechanisms and processes that are involved in causing the persistence of chromosomal and plasmid-borne resistance determinants and how we might use them to our advantage to increase the likelihood of reversing the problem. Of particular interest is the recent demonstration that a very low antibiotic concentration can be enriching for resistant bacteria and the implication that antibiotic release into the environment could contribute to the selection for resistance. Several mechanisms are contributing to the stability of antibiotic resistance in bacterial populations and even if antibiotic use is reduced it is likely that most resistance mechanisms will persist for considerable times.

  17. Structure of bacterial respiratory complex I.

    Science.gov (United States)

    Berrisford, John M; Baradaran, Rozbeh; Sazanov, Leonid A

    2016-07-01

    Complex I (NADH:ubiquinone oxidoreductase) plays a central role in cellular energy production, coupling electron transfer between NADH and quinone to proton translocation. It is the largest protein assembly of respiratory chains and one of the most elaborate redox membrane proteins known. Bacterial enzyme is about half the size of mitochondrial and thus provides its important "minimal" model. Dysfunction of mitochondrial complex I is implicated in many human neurodegenerative diseases. The L-shaped complex consists of a hydrophilic arm, where electron transfer occurs, and a membrane arm, where proton translocation takes place. We have solved the crystal structures of the hydrophilic domain of complex I from Thermus thermophilus, the membrane domain from Escherichia coli and recently of the intact, entire complex I from T. thermophilus (536 kDa, 16 subunits, 9 iron-sulphur clusters, 64 transmembrane helices). The 95Å long electron transfer pathway through the enzyme proceeds from the primary electron acceptor flavin mononucleotide through seven conserved Fe-S clusters to the unusual elongated quinone-binding site at the interface with the membrane domain. Four putative proton translocation channels are found in the membrane domain, all linked by the central flexible axis containing charged residues. The redox energy of electron transfer is coupled to proton translocation by the as yet undefined mechanism proposed to involve long-range conformational changes. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt.

  18. Bacterial invasion reconstructed molecule by molecule

    Energy Technology Data Exchange (ETDEWEB)

    Werner, James H [Los Alamos National Laboratory

    2009-01-01

    We propose to visualize the initial stages of bacterial infection of a human host cell with unmatched spatial and temporal resolution. This work will develop a new capability for the laboratory (super-resolution optical imaging), will test unresolved scientific hypotheses regarding host-pathogen interaction dynamics, and leverages state of the art 3D molecular tracking instrumentation developed recently by our group. There is much to be gained by applying new single molecule tools to the important and familiar problem of pathogen entry into a host cell. For example, conventional fluorescence microscopy has identified key host receptors, such as CD44 and {alpha}5{beta}1 integrin, that aggregate near the site of Salmonella typhimurium infection of human cells. However, due to the small size of the bacteria ({approx} 2 {micro}m) and the diffraction of the emitted light, one just sees a fluorescent 'blob' of host receptors that aggregate at the site of attachment, making it difficult to determine the exact number of receptors present or whether there is any particular spatial arrangement of the receptors that facilitates bacterial adhesion/entry. Using newly developed single molecule based super-resolution imaging methods, we will visualize how host receptors are directed to the site of pathogen adhesion and whether host receptors adopt a specific spatial arrangement for successful infection. Furthermore, we will employ our 3D molecular tracking methods to follow the injection of virulence proteins, or effectors, into the host cell by the pathogen Type III secretion system (TTSS). We expect these studies to provide mechanistic insights into the early events of pathogen infection that have here-to-fore been technically beyond our reach. Our Research Goals are: Goal 1--Construct a super-resolution fluorescence microscope and use this new capability to image the spatial distribution of different host receptors (e.g. CD44, as {alpha}5{beta}1 integrin) at the

  19. Prostatitis-bacterial - self-care

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000395.htm Prostatitis- bacterial - self-care To use the sharing features ... enable JavaScript. You have been diagnosed with bacterial prostatitis . This is an infection of the prostate gland. ...

  20. Cognitive outcome in adults after bacterial meningitis.

    NARCIS (Netherlands)

    Hoogman, M.; Beek, D. van de; Weisfelt, M.; Gans, J. de; Schmand, B.

    2007-01-01

    OBJECTIVE: To evaluate cognitive outcome in adult survivors of bacterial meningitis. METHODS: Data from three prospective multicentre studies were pooled and reanalysed, involving 155 adults surviving bacterial meningitis (79 after pneumococcal and 76 after meningococcal meningitis) and 72 healthy c

  1. Bacterial Cellulose From Rice Waste Water With Addition Chitosan, Glycerol, And Silver Nanoparticle

    Directory of Open Access Journals (Sweden)

    Eli Rohaeti

    2016-05-01

    Full Text Available This study aimed to prepare silver nanoparticles chemically, deposite silver nanoparticles on bacterial cellulose-chitosan-glycerol composite based rice waste water, as well as test the antibacterial activity of bacterial cellulose and its composite. Preparation of silver nanoparticles was conducted by chemical reduction of silver nitrate solution, as well as trisodium citrate as the reductor. Bacterial cellulose from rice waste water is fermented by the bacteria Acetobacter xylinum for 7 days. The dried bacterial cellulose was composited with chitosan and glycerol by immersion method on 2% of chitosan solution and 0.5% of glycerol solution. UV-Vis spectroscopy is used to determine the formation of silvernanoparticles and Particle Size Analyzer to test the size and particle size distribution. Characterization was conducted to bacterial cellulose and its composite included functional groups by FTIR, the mechanical properties by Tensile Tester, crystallinity by XRD, surface photograph by SEM, and antibacterial test against S. aureus and E. coli by the shake flask turbidimetry method. Silver nanoparticle characterization indicated that silver nanoparticles are formed at a wavelength of 421.80 nm, yellow, diameter particle size of 61.8 nm. SEM images showed that the surface of bacterial cellulose had deposited silver nanoparticles and antibacterial test showed an inhibitory effect of bacterial cellulose, bacterial cellulose-chitosan composite, and bacterial cellulose-chitosan-glycerol composite which are deposited silver nanoparticles against the growth of S. aureus and E. coli bacteria.

  2. Detection and identification of bacterial DNA in serum from patients with acute pancreatitis

    Science.gov (United States)

    de Madaria, E; Martínez, J; Lozano, B; Sempere, L; Benlloch, S; Such, J; Uceda, F; Francés, R; Pérez-Mateo, M

    2005-01-01

    Background and aims: Bacterial infections are common complications in patients with acute pancreatitis, and translocation of bacteria from the intestinal lumen is probably the first step in the pathogenesis of these infections. As blood cultures in afebrile patients are usually negative, more sensitive methods to investigate this hypothesis in patients are needed. Our group has recently developed a method to detect the presence of bacterial DNA in biological fluids, and we aimed to detect bacterial DNA in patients with acute pancreatitis, as molecular evidences of bacterial translocation. Methods: Samples of blood were obtained on three consecutive days within the first six days after admission. Bacterial DNA was detected using a polymerase chain reaction based method, and an automated DNA nucleotide sequencing process allowed identification of bacteria species. Results: Thirty one consecutively admitted patients with acute pancreatitis were studied. Bacterial DNA was detected in six patients (19.3%), and the sequencing process allowed identification of Citrobacter freundii and Pseudomonas aeruginosa. In two patients the same bacteria detected at admission was detected 24 hours later (above 99.9% homology of nucleotide sequence). Basic clinical and biochemical characteristics were similar among patients with or without the presence of bacterial DNA. Conclusion: Detection of gram negative bacteria derived bacterial DNA in our series supports the contention that bacterial translocation is a systemic process in approximately 20% of patients with acute pancreatitis that does not seem to be related to the severity of the episode or immediate development of infection. PMID:16099797

  3. Bacterial profiles of saliva in relation to diet, lifestyle factors, and socioeconomic status

    Directory of Open Access Journals (Sweden)

    Daniel Belstrøm

    2014-04-01

    Full Text Available Background and objective: The bacterial profile of saliva is composed of bacteria from different oral surfaces. The objective of this study was to determine whether different diet intake, lifestyle, or socioeconomic status is associated with characteristic bacterial saliva profiles. Design: Stimulated saliva samples from 292 participants with low levels of dental caries and periodontitis, enrolled in the Danish Health Examination Survey (DANHES, were analyzed for the presence of approximately 300 bacterial species by means of the Human Oral Microbe Identification Microarray (HOMIM. Using presence and levels (mean HOMIM-value of bacterial probes as endpoints, the influence of diet intake, lifestyle, and socioeconomic status on the bacterial saliva profile was analyzed by Mann–Whitney tests with Benjamini–Hochberg's correction for multiple comparisons and principal component analysis. Results: Targets for 131 different probes were identified in 292 samples, with Streptococcus and Veillonella being the most predominant genera identified. Two bacterial taxa (Streptococcus sobrinus and Eubacterium [11][G-3] brachy were more associated with smokers than non-smokers (adjusted p-value<0.01. Stratification of the group based on extreme ends of the parameters age, gender, alcohol consumption, body mass index (BMI, and diet intake had no statistical influence on the composition of the bacterial profile of saliva. Conversely, differences in socioeconomic status were reflected by the bacterial profiles of saliva. Conclusions: The bacterial profile of saliva seems independent of diet intake, but influenced by smoking and maybe socioeconomic status.

  4. Experimental warming effects on the bacterial community structure and diversity

    Science.gov (United States)

    Kim, W.; Han, S.; Adams, J.; Son, Y.

    2014-12-01

    The objective of this study is to investigate the responses of soil bacterial community to future temperature increase by conducting open-field warming experiment. We conducted an open-field experimental warming system using infra-red heater in 2011 and regulated the temperature of warmed plots by 3oC higher than that of control plots constantly. The seeds of Pinus densiflora, Abies holophylla, Abies koreana, Betula costata, Quercus variabilis, Fraxinus rhynchophylla, and Zelkova serrata were planted in each 1 m × 1 m plot (n=3) in April, 2012. We collected soil samples from the rhizosphere of 7 tree species. DNA was extracted and PCR-amplified for the bacterial 16S gene targeting V1-V3 region. The paired-end sequencing was performed at Beijing Genome Institute (BGI, Hong Kong, China) using 2× 100 bp Hiseq2000 (Illumina). This study aimed to answer the following prediction/hypothesis: 1) Experimental warming will change the structure of soil bacterial community, 2) There will be distinct 'indicator group' which response to warming treatment relatively more sensitive than other groups. 3) Warming treatment will enhance the microbial activity in terms of soil respiration. 4) The rhizoplane bacterial communities for each of 7 tree species will show different response pattern to warming treatment. Since the sequence data does not arrive before the submission deadline, therefore, we would like to present the results and discussions on December 2014, AGU Fall Meeting.

  5. Effect of cisapride on intestinal bacterial and endotoxin translocation in cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Shun-Cai Zhang; Wei Wang; Wei-Ying Ren; Bo-Ming He; Kang Zhou; Wu-Nan Zhu

    2003-01-01

    AIM: To investigate the effects of cisapride on intestinal bacterial overgrowth (IBO), bacterial and endotoxin translocation, intestinal transit and permeability in cirrhotic rats.METHODS: All animals were assessed with variables including bacterial and endotoxin translocation, intestinal bacterial overgrowth, intestinal transit and permeability.Bacterial translocation (BT) was assessed by bacterial culture of MLN, liver and spleen, IBO by a jejunal bacterial count of the specific organism, intestinal permeability by determination of the 24-hour urinary 99mTc-DTPA excretion and intestinal transit by measurement of the distribution of 51Cr in the intestine.RESULTS: Bacterial translocation (BT) and IBO was found in 48 % and 80 % cirrhotic rats respectively and none in control rats. Urinary excretion of 99mTc-DTPA in cirrhotic rats with BT (22.2±7.8) was greater than these without BT (10.5±2.9). Intestinal transit (geometric center ratio) was significantly delayed in cirrhotic rats (0.31±0.06) and further more delayed in cirrhotic rats with BT (0.24±0.06) than these without BT (0.38±0.11). Cirrhotic rats with IBO had significantly higher rates of intestinal bacterial and endotoxin translocation, slower intestinal transit time and higher intestinal permeability than those without IBO. It was also found that BT was closely associated with IBO and the injury of intestinal barrier. Compared with the placebo group,cisapride-treated rats had lower rates of bacterial/endotoxin translocation and IBO, which was closely associated with increased intestinal transit and improved intestinal permeability by cisapride.CONCLUSION: These results indicate that endotoxin and bacterial translocation in cirrhotic rats may be attributed to IBO and increased intestinal permeability. Cisapride that accelerates intestinal transit and improve intestinal permeability might be helpful in preventing intestinal bacterial and endotoxin translocation.

  6. Conformational analysis of thioglycoside derivatives of histo-blood group ABH antigens using an ab initio-derived reparameterization of MM4: implications for design of non-hydrolysable mimetics

    Science.gov (United States)

    Strino, Francesco; Lii, Jenn-Huei; Gabius, Hans-Joachim; Nyholm, Per-Georg

    2009-12-01

    Histo-blood group ABH antigens serve as recognition sites for infectious microorganisms and tissue lectins in intercellular communication, e.g. in tumor progression. Thus, they are of interest as a starting point for drug design. In this respect, potent non-hydrolysable derivatives such as thioglycosides are of special interest. As prerequisite to enable estimations of ligand properties relative to their natural counterparts, conformational properties of the thioglycosidic derivatives of ABH trisaccharides and their disaccharide units were calculated using systematic and filtered systematic searches with the MM4 force field. Parameters for the glycosidic torsions of thioglycosides were independently derived from ab initio calculations. The resulting energy deviations required a reparameterization of MM4 to a new parameter set called MM4R. The data sets obtained using MM4R reveal that the thioglycosides have somewhat increased levels of flexibility about the major low-energy conformations shared with the corresponding O-glycosides. In the trisaccharides, the thiosubstitution of the Gal[NAc]α1-3Gal linkage leads to a preference for a conformation which is the secondary minimum of the natural counterparts. This conformation also generates contacts between the N-acetyl group and the fucose moiety in the blood group A derivative. Calculations further indicate that thiosubstitution of only the Fucα1-2Gal linkage does not affect the conformational preferences compared to the natural trisaccharide. Thiosubstitution of both linkages in the trisaccharide results in increased flexibility but the favored conformation of the natural trisaccharides is preferred. The study suggests that thioglycoside derivatives of ABH antigens could have pharmaceutical interest as ligands of lectins and other carbohydrate-binding proteins.

  7. Distribution of Triplet Separators in Bacterial Genomes

    Institute of Scientific and Technical Information of China (English)

    HU Rui; ZHENG Wei-Mou

    2001-01-01

    Distributions of triplet separator lengths for two bacterial complete genomes are analyzed. The theoretical distributions for the independent random sequence and the first-order Markov chain are derived and compared with the distributions of the bacterial genomes. A prominent double band structure, which does not exist in the theoretical distributions, is observed in the bacterial distributions for most triplets.``

  8. A Comparative Analysis of Bacterial Growth with Earphone Use

    Directory of Open Access Journals (Sweden)

    Chiranjay Mukhopadhyay

    2008-07-01

    Full Text Available Background: Recently the worldwide usage of earphones has increased especially among the school and college students who have a high rate of sharing among them. Alike airline headsets, headphones and stethoscope ear-pieces, ear phones can easily be a vector of potential pathogens, which can give rise to otitis externa. Purpose: To compare the bacterial growth of the external ear in association with earphone and assess the role of earphones as vector or microorganisms. Material and Methods: 50 voluntary male subjects (age 18-25 years were chosen and divided into two groups, A and B, according to the use of earphones. Swabs were taken from their left ear and the left earpiece of the earphone. Samples were processed as recommended. Results: In group A, bacteria were found in 20 (80% ear and 14 (56% earphone swabs. In group B, bacteria were found in 23 (92% ear and 17 (68% earphone swabs. Group B showed heavy growth and a significant increase in the number of bacterial growths after frequent and constant use. Conclusion: Frequent and constant use of earphones increases the bacterial growth in the ear and sharing of earphones might be a potential vector of commensals. It is therefore, always better not to share or else to clean the earphones before sharing.

  9. Antibiotic drugs targeting bacterial RNAs

    Directory of Open Access Journals (Sweden)

    Weiling Hong

    2014-08-01

    Full Text Available RNAs have diverse structures that include bulges and internal loops able to form tertiary contacts or serve as ligand binding sites. The recent increase in structural and functional information related to RNAs has put them in the limelight as a drug target for small molecule therapy. In addition, the recognition of the marked difference between prokaryotic and eukaryotic rRNA has led to the development of antibiotics that specifically target bacterial rRNA, reduce protein translation and thereby inhibit bacterial growth. To facilitate the development of new antibiotics targeting RNA, we here review the literature concerning such antibiotics, mRNA, riboswitch and tRNA and the key methodologies used for their screening.

  10. Electromagnetic Signals from Bacterial DNA

    CERN Document Server

    Widom, A; Srivastava, Y N; Sivasubramanian, S

    2011-01-01

    Chemical reactions can be induced at a distance due to the propagation of electromagnetic signals during intermediate chemical stages. Although is is well known at optical frequencies, e.g. photosynthetic reactions, electromagnetic signals hold true for muck lower frequencies. In E. coli bacteria such electromagnetic signals can be generated by electric transitions between energy levels describing electrons moving around DNA loops. The electromagnetic signals between different bacteria within a community is a "wireless" version of intercellular communication found in bacterial communities connected by "nanowires". The wireless broadcasts can in principle be of both the AM and FM variety due to the magnetic flux periodicity in electron energy spectra in bacterial DNA orbital motions.

  11. Bacterial survival in Martian conditions

    CERN Document Server

    D'Alessandro, Giuseppe Galletta; Giulio Bertoloni; Maurizio

    2010-01-01

    We shortly discuss the observable consequences of the two hypotheses about the origin of life on Earth and Mars: the Lithopanspermia (Mars to Earth or viceversa) and the origin from a unique progenitor, that for Earth is called LUCA (the LUCA hypothesis). To test the possibility that some lifeforms similar to the terrestrial ones may survive on Mars, we designed and built two simulators of Martian environments where to perform experiments with different bacterial strains: LISA and mini-LISA. Our LISA environmental chambers can reproduce the conditions of many Martian locations near the surface trough changes of temperature, pressure, UV fluence and atmospheric composition. Both simulators are open to collaboration with other laboratories interested in performing experiments on many kind of samples (biological, minerals, electronic) in situations similar to that of the red planet. Inside LISA we have studied the survival of several bacterial strains and endospores. We verified that the UV light is the major re...

  12. Bacterial streamers in curved microchannels

    Science.gov (United States)

    Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

    2009-11-01

    Biofilms, generally identified as microbial communities embedded in a self-produced matrix of extracellular polymeric substances, are involved in a wide variety of health-related problems ranging from implant-associated infections to disease transmissions and dental plaque. The usual picture of these bacterial films is that they grow and develop on surfaces. However, suspended biofilm structures, or streamers, have been found in natural environments (e.g., rivers, acid mines, hydrothermal hot springs) and are always suggested to stem from a turbulent flow. We report the formation of bacterial streamers in curved microfluidic channels. By using confocal laser microscopy we are able to directly image and characterize the spatial and temporal evolution of these filamentous structures. Such streamers, which always connect the inner corners of opposite sides of the channel, are always located in the middle plane. Numerical simulations of the flow provide evidences for an underlying hydrodynamic mechanism behind the formation of the streamers.

  13. Bacterial chromosome organization and segregation.

    Science.gov (United States)

    Badrinarayanan, Anjana; Le, Tung B K; Laub, Michael T

    2015-01-01

    If fully stretched out, a typical bacterial chromosome would be nearly 1 mm long, approximately 1,000 times the length of a cell. Not only must cells massively compact their genetic material, but they must also organize their DNA in a manner that is compatible with a range of cellular processes, including DNA replication, DNA repair, homologous recombination, and horizontal gene transfer. Recent work, driven in part by technological advances, has begun to reveal the general principles of chromosome organization in bacteria. Here, drawing on studies of many different organisms, we review the emerging picture of how bacterial chromosomes are structured at multiple length scales, highlighting the functions of various DNA-binding proteins and the impact of physical forces. Additionally, we discuss the spatial dynamics of chromosomes, particularly during their segregation to daughter cells. Although there has been tremendous progress, we also highlight gaps that remain in understanding chromosome organization and segregation.

  14. Dynamics of bacterial gene regulation

    Science.gov (United States)

    Narang, Atul

    2009-03-01

    The phenomenon of diauxic growth is a classical problem of bacterial gene regulation. The most well studied example of this phenomenon is the glucose-lactose diauxie, which occurs because the expression of the lac operon is strongly repressed in the presence of glucose. This repression is often explained by appealing to molecular mechanisms such as cAMP activation and inducer exclusion. I will begin by analyzing data showing that these molecular mechanisms cannot explain the strong lac repression because they exert a relatively weak effect. I will then present a minimal model accounting only for enzyme induction and dilution, which yields strong repression despite the absence of catabolite repression and inducer exclusion. The model also explains the growth patterns observed in batch and continuous cultures of various bacterial strains and substrate mixtures. The talk will conclude with a discussion of the experimental evidence regarding positive feedback, the key component of the minimal model.

  15. Bacterial Interstitial Nephritis in Children

    OpenAIRE

    Bobadilla Chang, Fernando; Departamento de Ciencias Dinámicas Facultad de Medicina Universidad Nacional Mayor de San Marcos Lima, Perú; Villanueva, Dolores; Departamento de Ciencias Dinámicas Facultad de Medicina Universidad Nacional Mayor de San Marcos Lima, Perú

    2014-01-01

    OBJECTIVE: To assess the diagnosis approach to urinary tract infections in children. MATERIAL AND METHODS: Medical records from 103 children with diagnosis of interstitial bacterial nephritis were retrospectively reviewed. Diagnosis was supported by the dramatic involvement of renal parenquima, which is not addressed as "urinary tract infection". RESULTS: From all 103 patients, 49 were 2-years-old or younger, 33 were between 2 and 5-years-old, and 21 were between 6 to 10. Clinical picture inc...

  16. Bacterial canker resistance in tomato

    OpenAIRE

    Sen, Y.

    2014-01-01

    Clavibacter michiganensis subsp. michiganensis (Cmm) is the pathogen causing bacterial  canker in tomato. The disease was described for the first time in 1910 in Michigan, USA. Cmmis considered the most harmful bacteria threatening tomato. Disease transmission occurs via seed and symptoms become visible at least 20 days after infection. Due to its complex strategy and transmission, Cmm is under quarantine regulation in EU and other countries. There is no method to stop disease progress i...

  17. Small intestinal bacterial overgrowth syndrome

    Institute of Scientific and Technical Information of China (English)

    Jan; Bures; Jiri; Cyrany; Darina; Kohoutova; Miroslav; Frstl; Stanislav; Rejchrt; Jaroslav; Kvetina; Viktor; Vorisek; Marcela; Kopacova

    2010-01-01

    Human intestinal microbiota create a complex polymi-crobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO).SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastro-intestinal tract. There...

  18. Biotechnological applications of bacterial cellulases

    OpenAIRE

    Esther Menendez; Paula Garcia-Fraile; Raul Rivas

    2015-01-01

    Cellulases have numerous applications in several industries, including biofuel production, food and feed industry, brewing, pulp and paper, textile, laundry, and agriculture.Cellulose-degrading bacteria are widely spread in nature, being isolated from quite different environments. Cellulose degradation is the result of a synergic process between an endoglucanase, an exoglucanase and a,β-glucosidase. Bacterial endoglucanases degrade ß-1,4-glucan linkages of cellulose amorphous zones, mean...

  19. Bacterial motility on abiotic surfaces

    OpenAIRE

    Gibiansky, Maxsim

    2013-01-01

    Bacterial biofilms are structured microbial communities which are widespread both in nature and in clinical settings. When organized into a biofilm, bacteria are extremely resistant to many forms of stress, including a greatly heightened antibiotic resistance. In the early stages of biofilm formation on an abiotic surface, many bacteria make use of their motility to explore the surface, finding areas of high nutrition or other bacteria to form microcolonies. They use motility appendages, incl...

  20. From mapping class groups to automorphism groups of free groups

    DEFF Research Database (Denmark)

    Wahl, Nathalie

    2005-01-01

    We show that the natural map from the mapping class groups of surfaces to the automorphism groups of free groups, induces an infinite loop map on the classifying spaces of the stable groups after plus construction. The proof uses automorphisms of free groups with boundaries which play the role...... of mapping class groups of surfaces with several boundary components....

  1. Cytochemical Differences in Bacterial Glycocalyx

    Science.gov (United States)

    Krautgartner, Wolf Dietrich; Vitkov, Ljubomir; Hannig, Matthias; Pelz, Klaus; Stoiber, Walter

    2005-02-01

    To examine new cytochemical aspects of the bacterial adhesion, a strain 41452/01 of the oral commensal Streptococcus sanguis and a wild strain of Staphylococcus aureus were grown with and without sucrose supplementation for 6 days. Osmiumtetraoxyde (OsO4), uranyl acetate (UA), ruthenium red (RR), cupromeronic blue (CB) staining with critical electrolytic concentrations (CECs), and the tannic acid-metal salt technique (TAMST) were applied for electron microscopy. Cytochemically, only RR-positive fimbriae in S. sanguis were visualized. By contrast, some types of fimbriae staining were observed in S. aureus glycocalyx: RR-positive, OsO4-positive, tannophilic and CB-positive with ceasing point at 0.3 M MgCl2. The CB staining with CEC, used for the first time for visualization of glycoproteins of bacterial glycocalyx, also reveals intacellular CB-positive substances-probably the monomeric molecules, that is, subunits forming the fimbriae via extracellular assembly. Thus, glycosylated components of the biofilm matrix can be reliably related to single cells. The visualization of intracellular components by CB with CEC enables clear distinction between S. aureus and other bacteria, which do not produce CB-positive substances. The small quantities of tannophilic substances found in S. aureus makes the use of TAMST for the same purpose difficult. The present work protocol enables, for the first time, a partial cytochemical differentiation of the bacterial glycocalyx.

  2. DIAGNOSTIC DIFFICULTIES IN BACTERIAL SPONDYLODISCITIS

    Directory of Open Access Journals (Sweden)

    Vinicius Orso

    2015-12-01

    Full Text Available Objective : To analyze aspects related to the diagnostic difficulty in patients with bacterial spondylodiscitis. Methods : Cross-sectional observational study with retrospective data collected in the period from March 2004 to January 2014.Twenty-one patients diagnosed with bacterial spondylodiscitis were analyzed. Results : Women were the most affected, as well as older individuals. Pain in the affected region was the initial symptom in 52% of patients, and 45.5% of the patients had low back pain, and those with dorsal discitis had back pain as the main complaint; the patients with thoracolumbar discitis had pain in that region, and only one patient had sacroiliac discitis. The average time between onset of symptoms and treatment was five months. The lumbar segment was the most affected with 11 cases (52%, followed by thoracolumbar in 24%, dorsal in 19% of cases and a case in the sacroiliac segment. Only seven patients had fever. Pain in the affected level was coincidentally the most common symptom. Conclusions : Early diagnosis of bacterial spondylodiscitis remains a challenge due to the nonspecific signs and symptoms reported by the patient and the wide variability of laboratory results and imaging. The basis for early diagnosis remains the clinical suspicion at the time of initial treatment.

  3. Detergent-compatible bacterial amylases.

    Science.gov (United States)

    Niyonzima, Francois N; More, Sunil S

    2014-10-01

    Proteases, lipases, amylases, and cellulases are enzymes used in detergent formulation to improve the detergency. The amylases are specifically supplemented to the detergent to digest starchy stains. Most of the solid and liquid detergents that are currently manufactured contain alkaline enzymes. The advantages of using alkaline enzymes in the detergent formulation are that they aid in removing tough stains and the process is environmentally friendly since they reduce the use of toxic detergent ingredients. Amylases active at low temperature are preferred as the energy consumption gets reduced, and the whole process becomes cost-effective. Most microbial alkaline amylases are used as detergent ingredients. Various reviews report on the production, purification, characterization, and application of amylases in different industry sectors, but there is no specific review on bacterial or fungal alkaline amylases or detergent-compatible amylases. In this mini-review, an overview on the production and property studies of the detergent bacterial amylases is given, and the stability and compatibility of the alkaline bacterial amylases in the presence of the detergents and the detergent components are highlighted.

  4. Teaching Group Work with "The Great Debaters"

    Science.gov (United States)

    Moe, Jeffry; Autry, Linda; Olson, Joann S.; Johnson, Kaprea F.

    2014-01-01

    An experiential learning activity, based on the film "The Great Debaters" (Washington, D., 2007), was used during a group work class. Description and preliminary evaluation of the activity is provided, including analysis of participant scores on the group leader self-efficacy instrument at multiple points. Implications and future…

  5. Strategic Innovation of International Large Media Groups and the Implications to China%国外大型传媒集团战略革新对中国的启示

    Institute of Scientific and Technical Information of China (English)

    冉继军

    2013-01-01

    Media technological innovations serve as a catalyst for the evolution of media ecology and the new media technologies featured by digitization have greatly transformed the operating model and communication philosophies of large media groups. Through new media technology, they realized a deep integration of content and platforms; they took advantage of the business realignment to realize the convergence of different media, which further consolidated their predominance in international communication order. When cloud computing is the norm in the digital technology, media groups should design media products that meet the tailored needs of information consumers so as to gain competitive advantage in the industry.%媒介技术的进步是传播生态变革的催化剂,以数字技术为核心的新媒体技术深刻地改变了大众传播形态,并促使传统传媒集团不断进行战略革新.以英国广播公司等为代表的大型传媒集团利用新媒体技术对内容和渠道进行深度集成,充分挖掘受众的个性化需求,并以业务整合为契机实现跨媒体融合,进一步巩固了其在国际传播领域内的强势地位.面对新媒体变革所带来的机遇与挑战,中国媒体应该了解与西方传媒的差距,学习其先进的经验和方法,力争改变国际传播领域内“西强东弱”的局面.

  6. Temporal relationships exist between cecum, ileum and litter bacterial microbiomes in a commercial turkey flock, and subtherapeutic penicillin treatment impacts ileum bacterial community establishment

    Directory of Open Access Journals (Sweden)

    Jessica L Danzeisen

    2015-11-01

    Full Text Available Gut health is paramount for commercial poultry production, and improved methods to assess gut health are critically needed to better understand how the avian gastrointestinal tract matures over time. One important aspect of gut health is the totality of bacterial populations inhabiting different sites of the avian gastrointestinal tract, and associations of these populations with the poultry farm environment, since these bacteria are thought to drive metabolism and prime the developing host immune system. In this study, a single flock of commercial turkeys was followed over the course of twelve weeks to examine bacterial microbiome inhabiting the ceca, ileum, and corresponding poultry litter. Furthermore, the effects of low-dose, growth-promoting penicillin treatment (50 g/ton in feed on the ileum bacterial microbiome were also examined during the early brood period. The cecum and ileum bacterial communities of turkeys were distinct, yet shifted in parallel to one another over time during bird maturation. Corresponding poultry litter was also distinct yet more closely represented the ileal bacterial populations than cecal bacterial populations, and also changed parallel to ileum bacterial populations over time. Penicillin applied at low dose in feed significantly enhanced early weight gain in commercial poults, and this correlated with predictable shifts in the ileum bacterial populations in control versus treatment groups. Overall, this study identified the dynamics of the turkey gastrointestinal microbiome during development, correlations between bacterial populations in the gastrointestinal tract and the litter environment, and the impact of low-dose penicillin on modulation of bacterial communities in the ileum. Such modulations provide a target for alternatives to low-dose antibiotics.

  7. Bacterial community diversity in municipal waste landfill sites.

    Science.gov (United States)

    Song, Liyan; Wang, Yangqing; Tang, Wei; Lei, Yu

    2015-09-01

    Little is known about the bacterial diversity of landfills and how environmental factors impact the diversity. In this study, PCR-based 454 pyrosequencing was used to investigate the bacterial communities of ten landfill leachate samples from five landfill sites in China. A total of 137 K useable sequences from the V3-V6 regions of the 16S rRNA gene were retrieved from 205 K reads. These sequences revealed the presence of a large number of operational taxonomic units (OTUs) in the landfills (709-1599 OTUs per sample). The most predominant bacterial representatives in the landfills investigated, regardless of geographic area, included Gammaproteobacteria, Firmicutes, and Bacteroidetes. The phyla Fusobacteria and Tenericutes were also found for the first time to be predominant in the landfills. The phylum Fusobacteria predominated (51.5 and 48.8%) in two semi-arid landfills, and the phylum Tenericutes dominated (30.6%) at one humid, subtropical landfill. Further, a large number of Pseudomonas was detected in most samples, comprising the dominant group and accounting for 40.9 to 92.4% of the total abundance. Principal component analysis (PCA) and cluster analysis based on OTU abundance showed that the abundant taxa separated the bacterial community. Canonical correlation analysis (CCA) suggested that precipitation and landfilling age significantly impact on the bacterial community structure. The bacterial community function (e.g., cellulolytic bacteria, sulfate-reducing bacteria (SRB), sulfate-oxidizing bacteria, and xenobiotic organic compound (XOC)-degrading bacteria) was also diverse, but the pattern is unclear.

  8. The innate immune protein Nod2 binds directly to MDP, a bacterial cell wall fragment.

    Science.gov (United States)

    Grimes, Catherine Leimkuhler; Ariyananda, Lushanti De Zoysa; Melnyk, James E; O'Shea, Erin K

    2012-08-22

    Mammalian Nod2 is an intracellular protein that is implicated in the innate immune response to the bacterial cell wall and is associated with the development of Crohn's disease, Blau syndrome, and gastrointestinal cancers. Nod2 is required for an immune response to muramyl dipeptide (MDP), an immunostimulatory fragment of bacterial cell wall, but it is not known whether MDP binds directly to Nod2. We report the expression and purification of human Nod2 from insect cells. Using novel MDP self-assembled monolayers (SAMs), we provide the first biochemical evidence for a direct, high-affinity interaction between Nod2 and MDP.

  9. Multiresistant bacterial infections in liver cirrhosis: Clinical impact and new empirical antibiotic treatment policies

    Science.gov (United States)

    Acevedo, Juan

    2015-01-01

    Recently, important changes have been reported regarding the epidemiology of bacterial infections in liver cirrhosis. There is an emergence of multiresistant bacteria in many European countries and also worldwide, including the United States and South Korea. The classic empirical antibiotic treatment (third-generation cephalosporins, e.g., ceftriaxone, cefotaxime or amoxicillin-clavulanic acid) is still effective in infections acquired in the community, but its failure rate in hospital acquired infections and in some health-care associated infections is high enough to ban its use in these settings. The current editorial focuses on the different epidemiology of bacterial infections in cirrhosis across countries and on its therapeutic implications. PMID:25954474

  10. Analysis of Utilization of Carbapenem Drugs and Correlation of Bacterial Resistance Rate in Yangquan Coalmine Group General Hospital during 2011-2013%2011-2013年阳煤集团总医院碳青霉烯类药物应用情况与细菌耐药率相关性分析

    Institute of Scientific and Technical Information of China (English)

    潘苗

    2015-01-01

    目的:通过对碳青霉烯类药物应用情况及非发酵菌鲍曼不动杆菌( Acinetobacter baumannii, AB )和铜绿假单胞菌( Pseudomonas aeruginosa,P.aeruginosa,PA)对碳青霉烯类药物的耐药率进行相关性分析,从而促进临床合理用药。方法:采用回顾性分析,对山西省阳泉市阳煤集团总医院(以下简称“我院”)2011—2013年碳青霉烯类抗菌药物应用情况进行统计,同时将AB和PA对碳青霉烯类药物的耐药率进行统计和排序,分别使用SPSS 13.0统计软件和世界卫生组织细菌耐药性监测网提供WHONET 5.4软件进行数据分析。结果:2011—2013年我院碳青霉烯类药物使用强度分别为0.917、0.8432、0.5687,AB对碳青霉烯类药物的耐药率在2011、2012、2013年分别为79.58%、70.68%、81.91%,与使用强度无关;PA对碳青霉烯类药物的耐药率在2011、2012、2013年分别为56.05%、50.38%、38.35%,与使用强度呈显著正相关,差异有统计学意义(P<0.05)。结论:及时了解碳青霉烯类药物的耐药现状,掌握耐药机制及其用药原则,能延缓耐药菌株的发生并能促进该药的合理应用,同时对加强医院感染细菌学监测,杜绝感染爆发流行具有积极意义。%OBJECTIVE:To promote the clinical rational drug use through the analysis of utilization of carbapenem drugs and the correlation of resistance rate of non-fermenting bacteria-acinetobacterbaumannii(AB) and pseudomonas aeruginosa ( P.aeruginosa,PA) to carbapenem drugs.METHODS:Retrospective analysis was used to proceed statistics about utilization of carbapenem antibiotics in Yangquan Coalmine Group General Hospital ( hereinafter referred to as “our hospital”) during 2011-2013, meanwhile drug resistance rates about AB and PA to carbapenem drugs were statistically sorted.SPSS 13.0 statistical software and WHONET 5.4 software provided by WHO bacterial resistance monitoring

  11. Confinement: G(2) group case

    CERN Document Server

    Cossu, G; Di Giacomo, A; Lucini, B; Pica, C

    2007-01-01

    The gauge group being centreless, $G_2$ gauge theory is a good laboratory for studying the role of the centre of the group for colour confinement in Yang-Mills gauge theories. In this paper, we investigate $G_2$ pure gauge theory at finite temperature on the lattice. By studying the finite size scaling of the plaquette, the Polyakov loop and their susceptibilities, we show that a deconfinement phase transition takes place. The analysis of the pseudocritical exponents give strong evidence of the deconfinement transition being first order. Implications of our findings for scenarios of colour confinement are discussed.

  12. Rhamnolipid biosurfactants: evolutionary implications, applications and future prospects from untapped marine resource.

    Science.gov (United States)

    Kiran, George Seghal; Ninawe, Arun Shivanth; Lipton, Anuj Nishanth; Pandian, Vijayalakshmi; Selvin, Joseph

    2016-01-01

    Rhamnolipid-biosurfactants are known to be produced by the genus Pseudomonas, however recent literature reported that rhamnolipids (RLs) are distributed among diverse microbial genera. To integrate the evolutionary implications of rhamnosyl transferase among various groups of microorganisms, a comprehensive comparative motif analysis was performed amongst bacterial producers. Findings on new RL-producing microorganism is helpful from a biotechnological perspective and to replace infective P. aeruginosa strains which ultimately ensure industrially safe production of RLs. Halotolerant biosurfactants are required for efficient bioremediation of marine oil spills. An insight on the exploitation of marine microbes as the potential source of RL biosurfactants is highlighted in the present review. An economic production process, solid-state fermentation using agro-industrial and industrial waste would increase the scope of biosurfactants commercialization. Potential and prospective applications of RL-biosurfactants including hydrocarbon bioremediation, heavy metal removal, antibiofilm activity/biofilm disruption and greener synthesis of nanoparticles are highlighted in this review.

  13. Bacterial adhesion and biofilms on surfaces

    Institute of Scientific and Technical Information of China (English)

    Trevor Roger Garrett; Manmohan Bhakoo; Zhibing Zhang

    2008-01-01

    Bacterial adhesion has become a significant problem in industry and in the domicile,and much research has been done for deeper understanding of the processes involved.A generic biological model of bacterial adhesion and population growth called the bacterial biofilm growth cycle,has been described and modified many times.The biofilm growth cycle encompasses bacterial adhesion at all levels,starting with the initial physical attraction of bacteria to a substrate,and ending with the eventual liberation of cell dusters from the biofilm matrix.When describing bacterial adhesion one is simply describing one or more stages of biofilm development,neglecting the fact that the population may not reach maturity.This article provides an overview of bacterial adhesion.cites examples of how bac-terial adhesion affects industry and summarises methods and instrumentation used to improve our understanding of the adhesive prop-erties of bacteria.

  14. The risk of acquiring bacterial meningitis following surgery in Denmark, 1996-2009

    DEFF Research Database (Denmark)

    Howitz, M F; Homøe, P

    2014-01-01

    SUMMARY: This paper estimates the risk of bacterial meningitis following surgery between 1996 and 2009 in Denmark. We conducted two retrospective nationwide cohort studies; first by linking notified bacterial meningitis cases to the National Patient Registry to see how many had undergone a surgical...... procedure; second, we scrutinized notified bacterial meningitis cases to see if the clinician suspected a surgical procedure to be the aetiology. We found that ear, nose and throat surgery had an 11-fold, and neurosurgery a sevenfold, increased risk compared to the reference group in the first 10 days...... following surgery. Streptococcus pneumoniae was the pathogen most often involved. Operation procedures involving penetration of dura mater was associated with increased risk for post-operative bacterial meningitis. In absolute numbers we found few bacterial meningitis cases after surgery; however, patients...

  15. Anaerobes and Bacterial Vaginosis in Pregnancy: Virulence Factors Contributing to Vaginal Colonisation

    Directory of Open Access Journals (Sweden)

    Charlene W. J. Africa

    2014-07-01

    Full Text Available The aetiology and pathogenesis of bacterial vaginosis (BV is unclear but it appears to be associated with factors that disrupt the normal acidity of the vagina thus altering the equilibrium between the normal vaginal microbiota. BV has serious implications for female morbidity, including reports of pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. This paper reviewed new available information regarding possible factors contributing to the establishment of the BV vaginal biofilm, examined the proposed role of anaerobic microbial species recently detected by new culture-independent methods and discusses developments related to the effects of BV on human pregnancy. The literature search included Pubmed (NLM, LISTA (EBSCO, and Web of Science. Because of the complexity and diversity of population groups, diagnosis and methodology used, no meta-analysis was performed. Several anaerobic microbial species previously missed in the laboratory diagnosis of BV have been revealed while taking cognisance of newly proposed theories of infection, thereby improving our understanding and knowledge of the complex aetiology and pathogenesis of BV and its perceived role in adverse pregnancy outcomes.

  16. Antifungal agents: mode of action, mechanisms of resistance, and correlation of these mechanisms with bacterial resistance.

    Science.gov (United States)

    Ghannoum, M A; Rice, L B

    1999-10-01

    The increased use of antibacterial and antifungal agents in recent years has resulted in the development of resistance to these drugs. The significant clinical implication of resistance has led to heightened interest in the study of antimicrobial resistance from different angles. Areas addressed include mechanisms underlying this resistance, improved methods to detect resistance when it occurs, alternate options for the treatment of infections caused by resistant organisms, and strategies to prevent and control the emergence and spread of resistance. In this review, the mode of action of antifungals and their mechanisms of resistance are discussed. Additionally, an attempt is made to discuss the correlation between fungal and bacterial resistance. Antifungals can be grouped into three classes based on their site of action: azoles, which inhibit the synthesis of ergosterol (the main fungal sterol); polyenes, which interact with fungal membrane sterols physicochemically; and 5-fluorocytosine, which inhibits macromolecular synthesis. Many different types of mechanisms contribute to the development of resistance to antifungals. These mechanisms include alteration in drug target, alteration in sterol biosynthesis, reduction in the intercellular concentration of target enzyme, and overexpression of the antifungal drug target. Although the comparison between the mechanisms of resistance to antifungals and antibacterials is necessarily limited by several factors defined in the review, a correlation between the two exists. For example, modification of enzymes which serve as targets for antimicrobial action and the involvement of membrane pumps in the extrusion of drugs are well characterized in both the eukaryotic and prokaryotic cells.

  17. Bacterial plasmid-mediated quinolone resistance genes in aquatic environments in China

    Science.gov (United States)

    Yan, Lei; Liu, Dan; Wang, Xin-Hua; Wang, Yunkun; Zhang, Bo; Wang, Mingyu; Xu, Hai

    2017-01-01

    Emerging antimicrobial resistance is a major threat to human’s health in the 21st century. Understanding and combating this issue requires a full and unbiased assessment of the current status on the prevalence of antimicrobial resistance genes and their correlation with each other and bacterial groups. In aquatic environments that are known reservoirs for antimicrobial resistance genes, we were able to reach this goal on plasmid-mediated quinolone resistance (PMQR) genes that lead to resistance to quinolones and possibly also to the co-emergence of resistance to β-lactams. Novel findings were made that qepA and aac-(6′)-Ib genes that were previously regarded as similarly abundant with qnr genes are now dominant among PMQR genes in aquatic environments. Further statistical analysis suggested that the correlation between PMQR and β-lactam resistance genes in the environment is still weak, that the correlations between antimicrobial resistance genes could be weakened by sufficient wastewater treatment, and that the prevalence of PMQR has been implicated in environmental, pathogenic, predatory, anaerobic, and more importantly, human symbiotic bacteria. This work provides a comprehensive analysis of PMQR genes in aquatic environments in Jinan, China, and provides information with which combat with the antimicrobial resistance problem may be fought. PMID:28094345

  18. Birth of a W sex chromosome by horizontal transfer of Wolbachia bacterial symbiont genome

    Science.gov (United States)

    Leclercq, Sébastien; Thézé, Julien; Chebbi, Mohamed Amine; Giraud, Isabelle; Moumen, Bouziane; Ernenwein, Lise; Grève, Pierre; Cordaux, Richard

    2016-01-01

    Sex determination is a fundamental developmental pathway governing male and female differentiation, with profound implications for morphology, reproductive strategies, and behavior. In animals, sex differences between males and females are generally determined by genetic factors carried by sex chromosomes. Sex chromosomes are remarkably variable in origin and can differ even between closely related species, indicating that transitions occur frequently and independently in different groups of organisms. The evolutionary causes underlying sex chromosome turnover are poorly understood, however. Here we provide evidence indicating that Wolbachia bacterial endosymbionts triggered the evolution of new sex chromosomes in the common pillbug Armadillidium vulgare. We identified a 3-Mb insert of a feminizing Wolbachia genome that was recently transferred into the pillbug nuclear genome. The Wolbachia insert shows perfect linkage to the female sex, occurs in a male genetic background (i.e., lacking the ancestral W female sex chromosome), and is hemizygous. Our results support the conclusion that the Wolbachia insert is now acting as a female sex-determining region in pillbugs, and that the chromosome carrying the insert is a new W sex chromosome. Thus, bacteria-to-animal horizontal genome transfer represents a remarkable mechanism underpinning the birth of sex chromosomes. We conclude that sex ratio distorters, such as Wolbachia endosymbionts, can be powerful agents of evolutionary transitions in sex determination systems in animals. PMID:27930295

  19. Complete Deletion of the Fucose Operon in Haemophilus influenzae Is Associated with a Cluster in Multilocus Sequence Analysis-Based Phylogenetic Group II Related to Haemophilus haemolyticus: Implications for Identification and Typing.

    Science.gov (United States)

    de Gier, Camilla; Kirkham, Lea-Ann S; Nørskov-Lauritsen, Niels

    2015-12-01

    Nonhemolytic variants of Haemophilus haemolyticus are difficult to differentiate from Haemophilus influenzae despite a wide difference in pathogenic potential. A previous investigation characterized a challenging set of 60 clinical strains using multiple PCRs for marker genes and described strains that could not be unequivocally identified as either species. We have analyzed the same set of strains by multilocus sequence analysis (MLSA) and near-full-length 16S rRNA gene sequencing. MLSA unambiguously allocated all study strains to either of the two species, while identification by 16S rRNA sequence was inconclusive for three strains. Notably, the two methods yielded conflicting identifications for two strains. Most of the "fuzzy species" strains were identified as H. influenzae that had undergone complete deletion of the fucose operon. Such strains, which are untypeable by the H. influenzae multilocus sequence type (MLST) scheme, have sporadically been reported and predominantly belong to a single branch of H. influenzae MLSA phylogenetic group II. We also found evidence of interspecies recombination between H. influenzae and H. haemolyticus within the 16S rRNA genes. Establishing an accurate method for rapid and inexpensive identification of H. influenzae is important for disease surveillance and treatment.

  20. Microglial Amyloid-β1-40 Phagocytosis Dysfunction Is Caused by High-Mobility Group Box Protein-1: Implications for the Pathological Progression of Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Kazuyuki Takata

    2012-01-01

    Full Text Available In Alzheimer disease (AD patient brains, the accumulation of amyloid-β (Aβ peptides is associated with activated microglia. Aβ is derived from the amyloid precursor protein; two major forms of Aβ, that is, Aβ1-40 (Aβ40 and Aβ1-42 (Aβ42, exist. We previously reported that rat microglia phagocytose Aβ42, and high mobility group box protein 1 (HMGB1, a chromosomal protein, inhibits phagocytosis. In the present study, we investigated the effects of exogenous HMGB1 on rat microglial Aβ40 phagocytosis. In the presence of exogenous HMGB1, Aβ40 markedly increased in microglial cytoplasm, and the reduction of extracellular Aβ40 was inhibited. During this period, HMGB1 was colocalized with Aβ40 in the cytoplasm. Furthermore, exogenous HMGB1 inhibited the degradation of Aβ40 induced by the rat microglial cytosolic fraction. Thus, extracellular HMGB1 may internalize with Aβ40 in the microglial cytoplasm and inhibit Aβ40 degradation by microglia. This may subsequently delay Aβ40 clearance. We further confirmed that in AD brains, the parts of senile plaques surrounded by activated microglia are composed of Aβ40, and extracellular HMGB1 is deposited on these plaques. Taken together, microglial Aβ phagocytosis dysfunction may be caused by HMGB1 that accumulates extracellularly on Aβ plaques, and it may be critically involved in the pathological progression of AD.

  1. Bacterial meningitis and diseases caused by bacterial toxins.

    Science.gov (United States)

    Rings, D M

    1987-03-01

    Bacterial meningitis most commonly occurs in young calves secondary to septicemia. Clinical signs of hyperirritability are usually seen. Meningitis can be confirmed by cerebrospinal fluid analysis and culture or by necropsy. Intoxications by the exotoxins of Clostridium perfringens types C and D, C. botulinum, and C. tetani are difficult to confirm. The clinical signs of these intoxications vary from flaccid paralysis (botulism) to muscular rigidity (tetanus). Treatment of affected cattle has been unrewarding in botulism and enterotoxemia, whereas early aggressive treatment of tetanus cases can often be successfully resolved. Botulism and enterotoxemia can be proved using mouse inoculation tests, whereas tetanus is diagnosed largely by ruling out other diseases.

  2. Bacterial signaling and motility: Sure bets

    Energy Technology Data Exchange (ETDEWEB)

    Zhulin, Igor B [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)

    2008-01-01

    cytoplasmic membrane. The interaction causes the supramembrane and cytoplasmic rings to rotate along with the flagellar filaments. The energy for flagellar rotation comes from proton motive force or other ions, especially sodium in marine bacteria, which generate an electrochemical gradient across the cell membrane. Three proteins, FliM, FliN, and FliG, located at the base of the motor act as switches that control the direction of flagellar rotation. As exemplified by the enteric bacteria Escherichia coli and Salmonella enterica serovar Typhimurium, changes in the direction of flagellar rotation affect the swimming behavior of the bacterial cell. Counterclockwise (CCW) rotation of the flagella causes the flagellar filaments to form a bundle that pushes the cell forward in a 'run.' In contrast, clockwise (CW) rotation causes the flagellar bundle to fly apart, and the cell tumbles to reorient to a new direction for the ensuing run upon the return of CCW rotation. The interchanging pattern of CCW and CW rotations produces a random walk, composed of relatively long runs with occasional direction changes or turns. By modulating the lengths of the runs or the frequency of tumbling, bacteria can regulate their motile behavior to move in a desirable direction. Many bacteria can also move on surfaces. Except for flagellum-driven swarming motility, all the other forms of known bacterial surface movement involve no flagella. The flagellum-independent surface motility, known as gliding, is observed in cyanobacteria, Mycoplasma species, Cytophaga-Flexibacterium species, and Myxococcus species. Without a doubt, the most thoroughly studied model gliding bacterium is Myxococcus xanthus, which also serves as a prokaryotic model for developmental biology due to its ability to develop multicellular fruiting bodies. M. xanthus cells use gliding motility both to hunt for food during vegetative growth and to aggregate during fruiting body formation. When nutrients are present, groups of

  3. Effect of honey on bacterial translocation and intestinal morphology in obstructive jaundice

    Institute of Scientific and Technical Information of China (English)

    Cem Gencay; Sibel Serin Kilicoglu; Kemal Kismet; Bulent Kilicoglu; Serap Erel; Sabahattin Muratoglu; Asli Elif Sunay; Esra Erdemli; Mehmet Ali Akkus

    2008-01-01

    AIM:To evaluate the effects of honey on bacterial translocation and intestinal villus histopathology in experimental obstructive jaundice. METHODS:Thirty Wistar-Albino rats were randomly divided into three groups each including 10 animals:group Ⅰ, sham-operated;group Ⅱ,ligation and section of the common bile duct (BDL);group Ⅲ,bile duct ligation followed by oral supplementation of honey (BDL+honey) 10 g/kg per day.Liver, blood,spleen,mesenteric lymph nodes,and ileal samples were taken for microbiological,light and transmission electrone microscopic examination. RESULTS:Although the number of villi per centimeter and the height of the mucosa were higher in sham group,there was no statistically significant difference between sham and BDL+honey groups (P>0.05).On the other hand, there was a statistically significant difference between BDL group and other groups (P0.05).BDL group had significantly higher rates of bacterial translocation as compared with sham and honey groups. Bacterial translocation was predominantly detected in mesenteric lymph nodes. CONCLUSION: Supplementation of honey in presence of obstructive jaundice ameliorates bacterial translocation and improves ileal morphology.

  4. Analysis of bacterial diversity in sponges collected from Chuuk and Kosrae Islands in Micronesia.

    Science.gov (United States)

    Jeong, In-Hye; Kim, Kyoung-Ho; Lee, Hyi-Seung; Park, Jin-Sook

    2014-01-01

    The bacteria resident in sponges collected from Chuuk Lagoon and Kosrae Island of Micronesia were investigated using the 16S rRNA gene PCR-tagged pyrosequencing method. These sponges were clustered into 5 groups based on their bacterial composition. Diversity indexes and cumulative rank abundance curves showed the different compositions of bacterial communities in the various groups of sponges. Reads related to the phylum Chloroflexi were observed predominantly (9.7-68.2%) in 9 sponges of 3 groups and unobserved in the other 2 groups. The Chloroflexi-containing group had similar bacterial patterns at the phylum and lower taxonomic levels, for example, significant proportions of Acidobacteria, Gemmatimonadetes, SBR1093, and PAUC34f were observed in most members of this group. The three groups in the Chloroflexi-containing group, however, showed some minor differences in the composition and diversity. The other two groups contained high proportions of Proteobacteria (>87%) or Bacteroidetes (>61%) and different composition and diversity compared to the Chloroflexi-containing group and each other. Four pairs of specimens with the same species showed similar bacterial profiles, but, the bacteria in sponges were highly specific at the individual level.

  5. Responses of Baltic Sea ice and open-water natural bacterial communities to salinity change.

    Science.gov (United States)

    Kaartokallio, Hermanni; Laamanen, Maria; Sivonen, Kaarina

    2005-08-01

    To investigate the responses of Baltic Sea wintertime bacterial communities to changing salinity (5 to 26 practical salinity units), an experimental study was conducted. Bacterial communities of Baltic seawater and sea ice from a coastal site in southwest Finland were used in two batch culture experiments run for 17 or 18 days at 0 degrees C. Bacterial abundance, cell volume, and leucine and thymidine incorporation were measured during the experiments. The bacterial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified partial 16S rRNA genes with sequencing of DGGE bands from initial communities and communities of day 10 or 13 of the experiment. The sea ice-derived bacterial community was metabolically more active than the open-water community at the start of the experiment. Ice-derived bacterial communities were able to adapt to salinity change with smaller effects on physiology and community structure, whereas in the open-water bacterial communities, the bacterial cell volume evolution, bacterial abundance, and community structure responses indicated the presence of salinity stress. The closest relatives for all eight partial 16S rRNA gene sequences obtained were either organisms found in polar sea ice and other cold habitats or those found in summertime Baltic seawater. All sequences except one were associated with the alpha- and gamma-proteobacteria or the Cytophaga-Flavobacterium-Bacteroides group. The overall physiological and community structure responses were parallel in ice-derived and open-water bacterial assemblages, which points to a linkage between community structure and physiology. These results support previous assumptions of the role of salinity fluctuation as a major selective factor shaping the sea ice bacterial community structure.

  6. Prevalence of bacterial vaginosis and its risk factors in HIV/AIDSpatients with abnormal vaginal discharge

    Institute of Scientific and Technical Information of China (English)

    Samuel Nwadioha; Daniel Egah; Edmond Banwat; Julie Egesie; Ifeanyi Onwuezobe

    2011-01-01

    Objective:To determine the prevalence of bacterial vaginosis in theHIV/AIDS patients of primary health care clinics in Jos Plateau state, Nigeria.Methods: Female genital swabs were collected from primary health care centers, Jos and analyzed by microscopy, culture,etc. in Jos University Teaching Hospital from December2006 to December2007. Data on epidemiologic indices were collected, using structured interviewer-administered questionnaires.Results:The incidence of bacterial vaginosis in the study was 28%(n=196/700). Among theHIV/AIDS group, the bacterial vaginosis incidence was36% (n=126/350), while in the control (non-HIV patients) group, the rate was20% (70/350) with a statistically significant difference at 95 percent confidence level(P<0.05) .HIV/AIDSand non-HIV (control) patients contributed64% (n=126/196) and36%(n=70/196), respectively. The risks to bacterial vaginosis included vaginal douching with disinfectant/detergent constituted(60%), poor use of condom40%, a median age of26years, and a median number of3 sex partners per week.Conclusions: There was a significant statistical difference in prevalence of bacterial vaginosis between theHIV/AIDS group and non-HIV(control) group of patients in the study. Risk behaviors that promote the incidence of bacterial vaginosis should be especially paid attention.

  7. Crustose coralline algal species host distinct bacterial assemblages on their surfaces.

    Science.gov (United States)

    Sneed, Jennifer M; Ritson-Williams, Raphael; Paul, Valerie J

    2015-11-01

    Crustose coralline algae (CCA) are important components of many marine ecosystems. They aid in reef accretion and stabilization, create habitat for other organisms, contribute to carbon sequestration and are important settlement substrata for a number of marine invertebrates. Despite their ecological importance, little is known about the bacterial communities associated with CCA or whether differences in bacterial assemblages may have ecological implications. This study examined the bacterial communities on four different species of CCA collected in Belize using bacterial tag-encoded FLX amplicon pyrosequencing of the V1-V3 region of the 16S rDNA. CCA were dominated by Alphaproteobacteria, Gammaproteobacteria and Actinomycetes. At the operational taxonomic unit (OTU) level, each CCA species had a unique bacterial community that was significantly different from all other CCA species. Hydrolithon boergesenii and Titanoderma prototypum, CCA species that facilitate larval settlement in multiple corals, had higher abundances of OTUs related to bacteria that inhibit the growth and/or biofilm formation of coral pathogens. Fewer coral larvae settle on the surfaces of Paragoniolithon solubile and Porolithon pachydermum. These CCA species had higher abundances of OTUs related to known coral pathogens and cyanobacteria. Coral larvae may be able to use the observed differences in bacterial community composition on CCA species to assess the suitability of these substrata for settlement and selectively settle on CCA species that contain beneficial bacteria.

  8. Wzi is an outer membrane lectin that underpins group 1 capsule assembly in Escherichia coli.

    Science.gov (United States)

    Bushell, Simon R; Mainprize, Iain L; Wear, Martin A; Lou, Hubing; Whitfield, Chris; Naismith, James H

    2013-05-07

    Many pathogenic bacteria encase themselves in a polysaccharide capsule that provides a barrier to the physical and immunological challenges of the host. The mechanism by which the capsule assembles around the bacterial cell is unknown. Wzi, an integral outer-membrane protein from Escherichia coli, has been implicated in the formation of group 1 capsules. The 2.6 Å resolution structure of Wzi reveals an 18-stranded β-barrel fold with a novel arrangement of long extracellular loops that blocks the extracellular entrance and a helical bundle that plugs the periplasmic end. Mutagenesis shows that specific extracellular loops are required for in vivo capsule assembly. The data show that Wzi binds the K30 carbohydrate polymer and, crucially, that mutants functionally deficient in vivo show no binding to K30 polymer in vitro. We conclude that Wzi is a novel outer-membrane lectin that assists in the formation of the bacterial capsule via direct interaction with capsular polysaccharides.

  9. Wzi Is an Outer Membrane Lectin that Underpins Group 1 Capsule Assembly in Escherichia coli

    Science.gov (United States)

    Bushell, Simon R.; Mainprize, Iain L.; Wear, Martin A.; Lou, Hubing; Whitfield, Chris; Naismith, James H.

    2013-01-01

    Summary Many pathogenic bacteria encase themselves in a polysaccharide capsule that provides a barrier to the physical and immunological challenges of the host. The mechanism by which the capsule assembles around the bacterial cell is unknown. Wzi, an integral outer-membrane protein from Escherichia coli, has been implicated in the formation of group 1 capsules. The 2.6 Å resolution structure of Wzi reveals an 18-stranded β-barrel fold with a novel arrangement of long extracellular loops that blocks the extracellular entrance and a helical bundle that plugs the periplasmic end. Mutagenesis shows that specific extracellular loops are required for in vivo capsule assembly. The data show that Wzi binds the K30 carbohydrate polymer and, crucially, that mutants functionally deficient in vivo show no binding to K30 polymer in vitro. We conclude that Wzi is a novel outer-membrane lectin that assists in the formation of the bacterial capsule via direct interaction with capsular polysaccharides. PMID:23623732

  10. Diversity and abundance of the bacterial community of the red Macroalga Porphyra umbilicalis: did bacterial farmers produce macroalgae?

    Directory of Open Access Journals (Sweden)

    Lilibeth N Miranda

    Full Text Available Macroalgae harbor microbial communities whose bacterial biodiversity remains largely uncharacterized. The goals of this study were 1 to examine the composition of the bacterial community associated with Porphyra umbilicalis Kützing from Schoodic Point, ME, 2 determine whether there are seasonal trends in species diversity but a core group of bacteria that are always present, and 3 to determine how the microbial community associated with a laboratory strain (P.um.1 established in the presence of antibiotics has changed. P. umbilicalis blades (n = 5, fall 2010; n = 5, winter 2011; n = 2, clonal P.um.1 were analyzed by pyrosequencing over two variable regions of the 16 S rDNA (V5-V6 and V8; 147,880 total reads. The bacterial taxa present were classified at an 80% confidence threshold into eight phyla (Bacteroidetes, Proteobacteria, Planctomycetes, Chloroflexi, Actinobacteria, Deinococcus-Thermus, Firmicutes, and the candidate division TM7. The Bacteroidetes comprised the majority of bacterial sequences on both field and lab blades, but the Proteobacteria (Alphaproteobacteria, Gammaproteobacteria were also abundant. Sphingobacteria (Bacteroidetes and Flavobacteria (Bacteroidetes had inverse abundances on natural versus P.um.1 blades. Bacterial communities were richer and more diverse on blades sampled in fall compared to winter. Significant differences were observed between microbial communities among all three groups of blades examined. Only two OTUs were found on all 12 blades, and only one of these, belonging to the Saprospiraceae (Bacteroidetes, was abundant. Lewinella (as 66 OTUs was found on all field blades and was the most abundant genus. Bacteria from the Bacteroidetes, Proteobacteria and Planctomycetes that are known to digest the galactan sulfates of red algal cell walls were well-represented. Some of these taxa likely provide essential morphogenetic and beneficial nutritive factors to P. umbilicalis and may have had

  11. Microstructural observation and chemical dating on monazite from the Shilu Group, Hainan Province of South China: Implications for origin and evolution of the Shilu Fe-Co-Cu ore district

    Science.gov (United States)

    Xu, Deru; Kusiak, Monika A.; Wang, Zhilin; Chen, Huayong; Bakun-Czubarow, Nonna; Wu, Chuanjun; Konečný, Patrik; Hollings, Peter

    2015-02-01

    New monazite chemical U-Th-total-Pb (CHIME) ages, combined with microstructural observations, mineral compositions, and whole-rock geochemistry, indicate that the large-scale, banded iron formation (BIF)-type Shilu Fe-Co-Cu ore district in Hainan Province, South China is a multistage product of sedimentation, metamorphism, and hydrothermal-metasomatic alteration associated with multiple orogenies. Two types of monazite, i.e. "polygenetic" and "metamorphic", were identified. The "polygenetic monazite" comprises a magmatic and/or metamorphic core surrounded by a metamorphic rim, and shows complex zoning. Breakdown corona structure, with a core of monazite surrounded by a mantle of fluorapatite, allanite, and/or epidote as concentric growth rings, is commonly observed. This type of monazite yielded three main CHIME-age peaks at ca. 980 Ma, ca. 880 Ma and ca. 450 Ma. The ages which range up to ca. 880 Ma for detrital cores, record a pre-deformational magmatic and/or metamorphic event(s), and is considered to be the depositional time-interval of the Shilu Group and interbedded BIFs in a marine, back-arc foreland basin likely due to the Grenvillian or South China Sibao orogeny. After deposition, the Shilu district was subjected to an orogenic event, which is recorded by the syndeformational metamorphic monazite with ca. 560-450 Ma population. Probably this event not only caused amphibolite facies metamorphism and associated regional foliation S1 but also enriched the original BIFs, and most likely corresponds to the "Pan-African" and/or the South China Caledonian orogeny. The post-deformational "metamorphic" monazite occurs mostly as inclusions in garnet and shows ca. 260 Ma age. It likely represents the Late Permian post-magmatic hydrothermal and related retrograde event(s) initiated by the Indosinian orogeny due to the closure of the Paleo-Tethys. The breakdown of monazite to secondary coronal mineral phases as well as the Fe-remobilization and associated skarnization

  12. Bacterial Swarming: social behaviour or hydrodynamics?

    Science.gov (United States)

    Vermant, Jan

    2010-03-01

    Bacterial swarming of colonies is typically described as a social phenomenon between bacteria, whereby groups of bacteria collectively move atop solid surfaces. This multicellular behavior, during which the organized bacterial populations are embedded in an extracellular slime layer, is connected to important features such as biofilm formation and virulence. Despite the possible intricate quorum sensing mechanisms that regulate swarming, several physico-chemical phenomena may play a role in the dynamics of swarming and biofilm formation. Especially the striking fingering patterns formed by some swarmer colonies on relatively soft sub phases have attracted the attention as they could be the signatures of an instability. Recently, a parallel has been drawn between the swarming patterns and the spreading of viscous drops under the influence of a surfactant, which lead to similar patterns [1]. Starting from the observation that several of the molecules, essential in swarming systems, are strong biosurfactants, the possibility of flows driven by gradients in surface tension, has been proposed. This Marangoni flows are known to lead to these characteristic patterns. For Rhizobium etli not only the pattern formation, but also the experimentally observed spreading speed has been shown to be consistent with the one expected for Marangoni flows for the surface pressures, thickness, and viscosities that have been observed [2]. We will present an experimental study of swarming colonies of the bacteria Pseudomonas aeruginosa, the pattern formation, the surfactant gradients and height profiles in comparison with predictions of a thin film hydrodynamic model.[4pt] [1] Matar O.K. and Troian S., Phys. Fluids 11 : 3232 (1999)[0pt] [2] Daniels, R et al., PNAS, 103 (40): 14965-14970 (2006)

  13. Lymphocytic colitis: A clue to bacterial etiology

    Institute of Scientific and Technical Information of China (English)

    Thanaa EA Helal; Naglaa S Ahmed; Osama Abo El Fotoh

    2005-01-01

    AIM: To find out the role of bacteria as a possible etiological factor in lymphocytic colitis.METHODS: Twenty patients with histopathological diagnosis of lymphocytic colitis and 10 normal controls were included in this study. Colonoscopic biopsies were obtained from three sites (hepatic and splenic flexures and rectosigmoid region). Each biopsy was divided into two parts. A fresh part was incubated on special cultures for bacterial growth. The other part was used for the preparation of histologic tissue sections that were examined for the presence of bacteria with the help of Giemsa stain.RESULTS: Culture of tissue biopsies revealed bacterial growth in 18 out of 20 patients with lymphocytic colitis mostly Escherichia coli(14/18), which was found in all rectosigmoid specimens (14/14), but only in 8/14 and 6/14 of splenic and hepatic flexure specimens respectively. In two of these cases, E coliwas associated with proteus. Proteus was found only in one case, Klebsiella in two cases, and Staphylococcus aureus in one case. In the control group, only 2 out of 10 controls showed the growth of E coliin their biopsy cultures.Histopathology showed rod-shaped bacilli in the tissue sections of 12 out of 14 cases with positive E coliin their specimen's culture. None of the controls showed these bacteria in histopathological sections.CONCLUSION: This preliminary study reports an association between E coliand lymphocytic colitis, based on histological and culture observations. Serotyping and molecular studies are in process to assess the role of E coliin the pathogenesis of lymphocytic colitis.

  14. Validation of hierarchical cluster analysis for identification of bacterial species using 42 bacterial isolates

    Science.gov (United States)

    Ghebremedhin, Meron; Yesupriya, Shubha; Luka, Janos; Crane, Nicole J.

    2015-03-01

    Recent studies have demonstrated the potential advantages of the use of Raman spectroscopy in the biomedical field due to its rapidity and noninvasive nature. In this study, Raman spectroscopy is applied as a method for differentiating between bacteria isolates for Gram status and Genus species. We created models for identifying 28 bacterial isolates using spectra collected with a 785 nm laser excitation Raman spectroscopic system. In order to investigate the groupings of these samples, partial least squares discriminant analysis (PLSDA) and hierarchical cluster analysis (HCA) was implemented. In addition, cluster analyses of the isolates were performed using various data types consisting of, biochemical tests, gene sequence alignment, high resolution melt (HRM) analysis and antimicrobial susceptibility tests of minimum inhibitory concentration (MIC) and degree of antimicrobial resistance (SIR). In order to evaluate the ability of these models to correctly classify bacterial isolates using solely Raman spectroscopic data, a set of 14 validation samples were tested using the PLSDA models and consequently the HCA models. External cluster evaluation criteria of purity and Rand index were calculated at different taxonomic levels to compare the performance of clustering using Raman spectra as well as the other datasets. Results showed that Raman spectra performed comparably, and in some cases better than, the other data types with Rand index and purity values up to 0.933 and 0.947, respectively. This study clearly demonstrates that the discrimination of bacterial species using Raman spectroscopic data and hierarchical cluster analysis is possible and has the potential to be a powerful point-of-care tool in clinical settings.

  15. Arabidopsis lysin-motif proteins LYM1 LYM3 CERK1 mediate bacterial peptidoglycan sensing and immunity to bacterial infection

    Science.gov (United States)

    Willmann, Roland; Lajunen, Heini M.; Erbs, Gitte; Newman, Mari-Anne; Kolb, Dagmar; Tsuda, Kenichi; Katagiri, Fumiaki; Fliegmann, Judith; Bono, Jean-Jacques; Cullimore, Julie V.; Jehle, Anna K.; Götz, Friedrich; Kulik, Andreas; Molinaro, Antonio; Lipka, Volker; Gust, Andrea A.; Nürnberger, Thorsten

    2011-01-01

    Recognition of microbial patterns by host pattern recognition receptors is a key step in immune activation in multicellular eukaryotes. Peptidoglycans (PGNs) are major components of bacterial cell walls that possess immunity-stimulating activities in metazoans and plants. Here we show that PGN sensing and immunity to bacterial infection in Arabidopsis thaliana requires three lysin-motif (LysM) domain proteins. LYM1 and LYM3 are plasma membrane proteins that physically interact with PGNs and mediate Arabidopsis sensitivity to structurally different PGNs from Gram-negative and Gram-positive bacteria. lym1 and lym3 mutants lack PGN-induced changes in transcriptome activity patterns, but respond to fungus-derived chitin, a pattern structurally related to PGNs, in a wild-type manner. Notably, lym1, lym3, and lym3 lym1 mutant genotypes exhibit supersusceptibility to infection with virulent Pseudomonas syringae pathovar tomato DC3000. Defects in basal immunity in lym3 lym1 double mutants resemble those observed in lym1 and lym3 single mutants, suggesting that both proteins are part of the same recognition system. We further show that deletion of CERK1, a LysM receptor kinase that had previously been implicated in chitin perception and immunity to fungal infection in Arabidopsis, phenocopies defects observed in lym1 and lym3 mutants, such as peptidoglycan insensitivity and enhanced susceptibility to bacterial infection. Altogether, our findings suggest that plants share with metazoans the ability to recognize bacterial PGNs. However, as Arabidopsis LysM domain proteins LYM1, LYM3, and CERK1 form a PGN recognition system that is unrelated to metazoan PGN receptors, we propose that lineage-specific PGN perception systems have arisen through convergent evolution. PMID:22106285

  16. 16S rRNA gene pyrosequencing reveals bacterial dysbiosis in the duodenum of dogs with idiopathic inflammatory bowel disease.

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    Jan S Suchodolski

    Full Text Available BACKGROUND: Canine idiopathic inflammatory bowel disease (IBD is believed to be caused by a complex interaction of genetic, immunologic, and microbial factors. While mucosa-associated bacteria have been implicated in the pathogenesis of canine IBD, detailed studies investigating the enteric microbiota using deep sequencing techniques are lacking. The objective of this study was to evaluate mucosa-adherent microbiota in the duodenum of dogs with spontaneous idiopathic IBD using 16 S rRNA gene pyrosequencing. METHODOLOGY/PRINCIPAL FINDINGS: Biopsy samples of small intestinal mucosa were collected endoscopically from healthy dogs (n = 6 and dogs with moderate IBD (n = 7 or severe IBD (n = 7 as assessed by a clinical disease activity index. Total RNA was extracted from biopsy specimens and 454-pyrosequencing of the 16 S rRNA gene was performed on aliquots of cDNA from each dog. Intestinal inflammation was associated with significant differences in the composition of the intestinal microbiota when compared to healthy dogs. PCoA plots based on the unweighted UniFrac distance metric indicated clustering of samples between healthy dogs and dogs with IBD (ANOSIM, p<0.001. Proportions of Fusobacteria (p = 0.010, Bacteroidaceae (p = 0.015, Prevotellaceae (p = 0.022, and Clostridiales (p = 0.019 were significantly more abundant in healthy dogs. In contrast, specific bacterial genera within Proteobacteria, including Diaphorobacter (p = 0.044 and Acinetobacter (p = 0.040, were either more abundant or more frequently identified in IBD dogs. CONCLUSIONS/SIGNIFICANCE: In conclusion, dogs with spontaneous IBD exhibit alterations in microbial groups, which bear resemblance to dysbiosis reported in humans with chronic intestinal inflammation. These bacterial groups may serve as useful targets for monitoring intestinal inflammation.

  17. Bacterial Genotoxins: Merging the DNA Damage Response into Infection Biology

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    Francesca Grasso

    2015-08-01

    Full Text Available Bacterial genotoxins are unique among bacterial toxins as their molecular target is DNA. The consequence of intoxication or infection is induction of DNA breaks that, if not properly repaired, results in irreversible cell cycle arrest (senescence or death of the target cells. At present, only three bacterial genotoxins have been identified. Two are protein toxins: the cytolethal distending toxin (CDT family produced by a number of Gram-negative bacteria and the typhoid toxin produced by Salmonella enterica serovar Typhi. The third member, colibactin, is a peptide-polyketide genotoxin, produced by strains belonging to the phylogenetic group B2 of Escherichia coli. This review will present the cellular effects of acute and chronic intoxication or infection with the genotoxins-producing bacteria. The carcinogenic properties and the role of these effectors in the context of the host-microbe interaction will be discussed. We will further highlight the open questions that remain to be solved regarding the biology of this unusual family of bacterial toxins.

  18. Transforming microbial genotyping: a robotic pipeline for genotyping bacterial strains.

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    Brian O'Farrell

    Full Text Available Microbial genotyping increasingly deals with large numbers of samples, and data are commonly evaluated by unstructured approaches, such as spread-sheets. The efficiency, reliability and throughput of genotyping would benefit from the automation of manual manipulations within the context of sophisticated data storage. We developed a medium- throughput genotyping pipeline for MultiLocus Sequence Typing (MLST of bacterial pathogens. This pipeline was implemented through a combination of four automated liquid handling systems, a Laboratory Information Management System (LIMS consisting of a variety of dedicated commercial operating systems and programs, including a Sample Management System, plus numerous Python scripts. All tubes and microwell racks were bar-coded and their locations and status were recorded in the LIMS. We also created a hierarchical set of items that could be used to represent bacterial species, their products and experiments. The LIMS allowed reliable, semi-automated, traceable bacterial genotyping from initial single colony isolation and sub-cultivation through DNA extraction and normalization to PCRs, sequencing and MLST sequence trace evaluation. We also describe robotic sequencing to facilitate cherrypicking of sequence dropouts. This pipeline is user-friendly, with a throughput of 96 strains within 10 working days at a total cost of 200,000 items were processed by two to three people. Our sophisticated automated pipeline can be implemented by a small microbiology group without extensive external support, and provides a general framework for semi-automated bacterial genotyping of large numbers of samples at low cost.

  19. Bacterial Communities of Three Saline Meromictic Lakes in Central Asia.

    Science.gov (United States)

    Baatar, Bayanmunkh; Chiang, Pei-Wen; Rogozin, Denis Yu; Wu, Yu-Ting; Tseng, Ching-Hung; Yang, Cheng-Yu; Chiu, Hsiu-Hui; Oyuntsetseg, Bolormaa; Degermendzhy, Andrey G; Tang, Sen-Lin

    2016-01-01

    Meromictic lakes located in landlocked steppes of central Asia (~2500 km inland) have unique geophysiochemical characteristics compared to other meromictic lakes. To characterize their bacteria and elucidate relationships between those bacteria and surrounding environments, water samples were collected from three saline meromictic lakes (Lakes Shira, Shunet and Oigon) in the border between Siberia and the West Mongolia, near the center of Asia. Based on in-depth tag pyrosequencing, bacterial communities were highly variable and dissimilar among lakes and between oxic and anoxic layers within individual lakes. Proteobacteria, Bacteroidetes, Cyanobacteria, Actinobacteria and Firmicutes were the most abundant phyla, whereas three genera of purple sulfur bacteria (a novel genus, Thiocapsa and Halochromatium) were predominant bacterial components in the anoxic layer of Lake Shira (~20.6% of relative abundance), Lake Shunet (~27.1%) and Lake Oigon (~9.25%), respectively. However, few known green sulfur bacteria were detected. Notably, 3.94% of all sequencing reads were classified into 19 candidate divisions, which was especially high (23.12%) in the anoxic layer of Lake Shunet. Furthermore, several hydro-parameters (temperature, pH, dissolved oxygen, H2S and salinity) were associated (P< 0.05) with variations in dominant bacterial groups. In conclusion, based on highly variable bacterial composition in water layers or lakes, we inferred that the meromictic ecosystem was characterized by high diversity and heterogenous niches.

  20. Repeatability of differential goat bulk milk culture and associations with somatic cell count, total bacterial count, and standard plate count

    NARCIS (Netherlands)

    Koop, G.; Dik, N.; Nielen, M.; Lipman, L.J.A.

    2010-01-01

    The aims of this study were to assess how different bacterial groups in bulk milk are related to bulk milk somatic cell count (SCC), bulk milk total bacterial count (TBC), and bulk milk standard plate count (SPC) and to measure the repeatability of bulk milk culturing. On 53 Dutch dairy goat farms,

  1. Life Cycles of Ad Hoc Task Groups

    Science.gov (United States)

    1983-10-01

    solving development raises some final questions. If groups are normally preoccupied with different issues at different times, if their capabilities change...context, and group across the group’s life cycle? If such modifications normally occur, there could be substantial implications, both for our theoretical...This, and Diane’s impatient question "What are we accomplishing then?" suggest the Iroup’s need to stop trying to coax the attractive first solucion

  2. Phylogenetic analysis of bacterial community in deep-sea sediment from the western Pacific "warm pool"

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A depth profile of bacterial community structure in one deep-sea sediment core of the western Pacific "warm pool" (WP) was investigated and compared with that in a sediment sample from the eastern Pacific (EP) by phylogenetic analysis of 16S rDNA fragments.Five bacterial 16S rDNA clone libraries were constructed, and t33 clones with different restriction fragment length polymorphism(RFLP) patterns were sequenced. A phylogenetic analysis of these sequences revealed that the bacterial diversity in a sample from the WP was more abundant than that in the EP sample. The bacterial population in the sediment core of WP was composed of eight major lineages of the domain bacteria. Among them the γ-Proteobacteria was the predominant and most diverse group in each section of WP sediment core, followed by the α-Proteobacteria. The genus Colwellia belonging to γ-Proteobacteria was predominant in this sample.The shift of bacterial communities among different sections of the WP sediment core was δ-, ε-Proteobacteria, and Cytopahga-Flexibacteria-Bacteroides (CFB) group. The ratios between them in the bacterial communities all showed inversely proportional to the depth of sediment. The sequences related to sulphate reducing bacteria (SRB) were detected in every section. The bacterial community structure in this sediment core might be related to the environmental characteristics of the surface seawater of the western Pacific WP.

  3. Comparison on Serum Levels of Procalcitonin of Children with Viral and Bacterial Infection

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Objective To compare and analyze serum levels of procalcitonin (PCT) of children with viral and bacterial infection and probe into the importance of determining the level of serum PCT in the diagnosis of bacterial infection in order to provide evidences of the clinical use of antibiotics. Methods A total of 85 cases of children with an average age of 8.9 years (10 months-12 years) were enrolled in this study, 53 cases were with viral infection and 32 cases with bacterial infection. We determined serum levels of PCT by semi-quantitative solid phase immunoassay, and the serum levels of PCT were divided into four grades as Results The serum level of PCT of the group with bacterial infection were signiifcantly higher than that of the group with viral infection (P Conclusions Serum PCT is a bacterial sensitive marker of bacterial infection in children, and the determination of the level of serum PCT is helpful for the diagnosis of bacterial infection, which can also be a basis for the use of antibiotics.

  4. Effect of treatment of bacterial vaginosis on disease activity in rheumatoid arthritis

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    M. Kalhor

    2016-06-01

    Full Text Available Background: Rheumatoid arthritis is one of the most common autoimmune diseases in women of reproductive age. Studies have shown that bacterial vaginosis can affect the activity of rheumatoid arthritis. Objective: The aim of this study was to investigate the effect of treatment of bacterial vaginosis on disease activity in rheumatoid arthritis. Methods: This interventional study was conducted in 100 women with rheumatoid arthritis (50 women with bacterial vaginosis and 50 women without bacterial vaginosis referred to the Rheumatology clinic in Tehran during 2013. The activity of rheumatoid arthritis was assessed by DAS-28 in both groups before the study. The women were treated with oral metronidazole 500 mg twice daily for one week in the intervention group. The disease activity was also assessed in both groups after the study. Data were analyzed using T-test, Chi-square test, and ANOVA. Findings: The disease activity was not significantly different between the two the groups before the study. But the disease activity in the intervention group was significantly lower than the control group after the study. Conclusion: With regards to the results, it seems that the treatment of bacterial vaginosis can improve the activity of rheumatoid arthritis. These findings indicate the importance of attention to health care in women with rheumatoid arthritis by healthcare providers.

  5. Spatial Distribution of Bacterial Communities Driven by Multiple Environmental Factors in a Beach Wetland of the Largest Freshwater Lake in China

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    Xia eDing

    2015-02-01

    Full Text Available The spatial distributions of bacterial communities may be driven by multiple environmental factors. Thus, understanding the relationships between bacterial distribution and environmental factors is critical for understanding wetland stability and the functioning of freshwater lakes. However, little research on the bacterial communities in deep sediment layers exists. In this study, thirty clone libraries of 16S rRNA were constructed from a beach wetland of the Poyang Lake along both horizontal (distance to the water-land junction and vertical (sediment depth gradients to assess the effects of sediment properties on bacterial community structure and diversity. Our results showed that bacterial diversity increased along the horizontal gradient and decreased along the vertical gradient. The heterogeneous sediment properties along gradients substantially affected the dominant bacterial groups at the phylum and species levels. For example, the NH4+ concentration decreased with increasing depth, which was positively correlated with the relative abundance of Alphaproteobacteria. The changes in bacterial diversity and dominant bacterial groups showed that the top layer had a different bacterial community structure than the deeper layers. Principal component analysis revealed that both gradients, not each gradient independently, contributed to the shift in the bacterial community structure. A multiple linear regression model explained the changes in bacterial diversity and richness along the depth and distance gradients. Overall, our results suggest that spatial gradients associated with sediment properties shaped the bacterial communities in the Poyang Lake beach wetland.

  6. Silane meets click chemistry: towards the functionalization of wet bacterial cellulose sheets.

    Science.gov (United States)

    Hettegger, Hubert; Sumerskii, Ivan; Sortino, Salvatore; Potthast, Antje; Rosenau, Thomas

    2015-02-01

    The modification of cellulosic materials is of great interest in materials research. Wet bacterial cellulose sheets were modified by an alkoxysilane under mild conditions to make them accessible to click chemistry derivatization. For this purpose (3-azidopropyl)triethoxysilane was grafted covalently onto the cellulosic surface. The silanized bacterial cellulose sheets were characterized comprehensively by attenuated total reflectance FTIR spectroscopy, solid-state NMR spectroscopy, thermogravimetric analysis, SEM with energy-dispersive X-ray spectroscopy, and elemental analysis. To demonstrate subsequent click chemistry functionalization, a new fluorophore based on fluorescein was synthesized and clicked to the silane-modified bacterial cellulose. The new method renders bacterial cellulose and other never-dried cellulosic materials susceptible to direct and facile functionalization in an aqueous medium without the need to work in water-free organic phases or to employ extensive protecting group chemistry and functional group interconversion.

  7. Potential Use of Bacterial Community Succession in Decaying Human Bone for Estimating Postmortem Interval.

    Science.gov (United States)

    Damann, Franklin E; Williams, Daniel E; Layton, Alice C

    2015-07-01

    Bacteria are taphonomic agents of human decomposition, potentially useful for estimating postmortem interval (PMI) in late-stage decomposition. Bone samples from 12 individuals and three soil samples were analyzed to assess the effects of decomposition and advancing time on bacterial communities. Results indicated that partially skeletonized remains maintained a presence of bacteria associated with the human gut, whereas bacterial composition of dry skeletal remains maintained a community profile similar to soil communities. Variation in the UniFrac distances was significantly greater between groups than within groups (p < 0.001) for the unweighted metric and not the weighted metric. The members of the bacterial communities were more similar within than between decomposition stages. The oligotrophic environment of bone relative to soft tissue and the physical protection of organic substrates may preclude bacterial blooms during the first years of skeletonization. Therefore, community membership (unweighted) may be better for estimating PMI from skeletonized remains than community structure (weighted).

  8. Metagenomic analysis of bacterial and archaeal assemblages in the soil-mousse surrounding a geothermal spring

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    Sonu Bhatia

    2015-09-01

    Full Text Available The soil-mousse surrounding a geothermal spring was analyzed for bacterial and archaeal diversity using 16S rRNA gene amplicon metagenomic sequencing which revealed the presence of 18 bacterial phyla distributed across 109 families and 219 genera. Firmicutes, Actinobacteria, and the Deinococcus-Thermus group were the predominant bacterial assemblages with Crenarchaeota and Thaumarchaeota as the main archaeal assemblages in this largely understudied geothermal habitat. Several metagenome sequences remained taxonomically unassigned suggesting the presence of a repertoire of hitherto undescribed microbes in this geothermal soil-mousse econiche.

  9. Modulation of Bacterial Multidrug Resistance Efflux Pumps of the Major Facilitator Superfamily

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    Sanath Kumar

    2013-01-01

    Full Text Available Bacterial infections pose a serious public health concern, especially when an infectious disease has a multidrug resistant causative agent. Such multidrug resistant bacteria can compromise the clinical utility of major chemotherapeutic antimicrobial agents. Drug and multidrug resistant bacteria harbor several distinct molecular mechanisms for resistance. Bacterial antimicrobial agent efflux pumps represent a major mechanism of clinical resistance. The major facilitator superfamily (MFS is one of the largest groups of solute transporters to date and includes a significant number of bacterial drug and multidrug efflux pumps. We review recent work on the modulation of multidrug efflux pumps, paying special attention to those transporters belonging primarily to the MFS.

  10. Novel Perspectives on the Characterization of Species-Dependent Optical Signatures of Bacterial Colonies by Digital Holography.

    Science.gov (United States)

    Buzalewicz, Igor; Kujawińska, Małgorzata; Krauze, Wojciech; Podbielska, Halina

    2016-01-01

    The use of light diffraction for the microbiological diagnosis of bacterial colonies was a significant breakthrough with widespread implications for the food industry and clinical practice. We previously confirmed that optical sensors for bacterial colony light diffraction can be used for bacterial identification. This paper is focused on the novel perspectives of this method based on digital in-line holography (DIH), which is able to reconstruct the amplitude and phase properties of examined objects, as well as the amplitude and phase patterns of the optical field scattered/diffracted by the bacterial colony in any chosen observation plane behind the object from single digital hologram. Analysis of the amplitude and phase patterns inside a colony revealed its unique optical properties, which are associated with the internal structure and geometry of the bacterial colony. Moreover, on a computational level, it is possible to select the desired scattered/diffracted pattern within the entire observation volume that exhibits the largest amount of unique, differentiating bacterial features. These properties distinguish this method from the already proposed sensing techniques based on light diffraction/scattering of bacterial colonies. The reconstructed diffraction patterns have a similar spatial distribution as the recorded Fresnel patterns, previously applied for bacterial identification with over 98% accuracy, but they are characterized by both intensity and phase distributions. Our results using digital holography provide new optical discriminators of bacterial species revealed in one single step in form of new optical signatures of bacterial colonies: digital holograms, reconstructed amplitude and phase patterns, as well as diffraction patterns from all observation space, which exhibit species-dependent features. To the best of our knowledge, this is the first report on bacterial colony analysis via digital holography and our study represents an innovative approach

  11. Novel Perspectives on the Characterization of Species-Dependent Optical Signatures of Bacterial Colonies by Digital Holography.

    Directory of Open Access Journals (Sweden)

    Igor Buzalewicz

    Full Text Available The use of light diffraction for the microbiological diagnosis of bacterial colonies was a significant breakthrough with widespread implications for the food industry and clinical practice. We previously confirmed that optical sensors for bacterial colony light diffraction can be used for bacterial identification. This paper is focused on the novel perspectives of this method based on digital in-line holography (DIH, which is able to reconstruct the amplitude and phase properties of examined objects, as well as the amplitude and phase patterns of the optical field scattered/diffracted by the bacterial colony in any chosen observation plane behind the object from single digital hologram. Analysis of the amplitude and phase patterns inside a colony revealed its unique optical properties, which are associated with the internal structure and geometry of the bacterial colony. Moreover, on a computational level, it is possible to select the desired scattered/diffracted pattern within the entire observation volume that exhibits the largest amount of unique, differentiating bacterial features. These properties distinguish this method from the already proposed sensing techniques based on light diffraction/scattering of bacterial colonies. The reconstructed diffraction patterns have a similar spatial distribution as the recorded Fresnel patterns, previously applied for bacterial identification with over 98% accuracy, but they are characterized by both intensity and phase distributions. Our results using digital holography provide new optical discriminators of bacterial species revealed in one single step in form of new optical signatures of bacterial colonies: digital holograms, reconstructed amplitude and phase patterns, as well as diffraction patterns from all observation space, which exhibit species-dependent features. To the best of our knowledge, this is the first report on bacterial colony analysis via digital holography and our study represents an

  12. [Some immunological changes in children with bacterial infections treated with bacteriophages].

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    Pagava, K I; Metskhvarishvili, G D; Gachechiladze, K