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Sample records for bacterial family vibrionaceae

  1. Global and Phylogenetic Distribution of Quorum Sensing Signals, Acyl Homoserine Lactones, in the Family of Vibrionaceae

    PubMed Central

    Barker Rasmussen, Bastian; Fog Nielsen, Kristian; Machado, Henrique; Melchiorsen, Jette; Gram, Lone; Sonnenschein, Eva C.

    2014-01-01

    Bacterial quorum sensing (QS) and the corresponding signals, acyl homoserine lactones (AHLs), were first described for a luminescent Vibrio species. Since then, detailed knowledge has been gained on the functional level of QS; however, the abundance of AHLs in the family of Vibrionaceae in the environment has remained unclear. Three hundred and one Vibrionaceae strains were collected on a global research cruise and the prevalence and profile of AHL signals in this global collection were determined. AHLs were detected in 32 of the 301 strains using Agrobacterium tumefaciens and Chromobacterium violaceum reporter strains. Ethyl acetate extracts of the cultures were analysed by ultra-high performance liquid chromatography-high resolution mass spectrometry (MS) with automated tandem MS confirmation for AHLs. N-(3-hydroxy-hexanoyl) (OH-C6) and N-(3-hydroxy-decanoyl) (OH-C10) homoserine lactones were the most common AHLs found in 17 and 12 strains, respectively. Several strains produced a diversity of different AHLs, including N-heptanoyl (C7) HL. AHL-producing Vibrionaceae were found in polar, temperate and tropical waters. The AHL profiles correlated with strain phylogeny based on gene sequence homology, however not with geographical location. In conclusion, a wide range of AHL signals are produced by a number of clades in the Vibrionaceae family and these results will allow future investigations of inter- and intra-species interactions within this cosmopolitan family of marine bacteria. PMID:25419995

  2. Post-Genomic Analysis of Members of the Family Vibrionaceae.

    PubMed

    Boyd, E Fidelma; Carpenter, Megan R; Chowdhury, Nityananda; Cohen, Analuisa L; Haines-Menges, Brandy L; Kalburge, Sai S; Kingston, Joseph J; Lubin, J B; Ongagna-Yhombi, Serge Y; Whitaker, W Brian

    2015-10-01

    Similar to other genera and species of bacteria, whole genomic sequencing has revolutionized how we think about and address questions of basic Vibrio biology. In this review we examined 36 completely sequenced and annotated members of the Vibrionaceae family, encompassing 12 different species of the genera Vibrio, Aliivibrio, and Photobacterium. We reconstructed the phylogenetic relationships among representatives of this group of bacteria by using three housekeeping genes and 16S rRNA sequences. With an evolutionary framework in place, we describe the occurrence and distribution of primary and alternative sigma factors, global regulators present in all bacteria. Among Vibrio we show that the number and function of many of these sigma factors differs from species to species. We also describe the role of the Vibrio-specific regulator ToxRS in fitness and survival. Examination of the biochemical capabilities was and still is the foundation of classifying and identifying new Vibrio species. Using comparative genomics, we examine the distribution of carbon utilization patterns among Vibrio species as a possible marker for understanding bacteria-host interactions. Finally, we discuss the significant role that horizontal gene transfer, specifically, the distribution and structure of integrons, has played in Vibrio evolution. PMID:26542048

  3. Evaluation of the L-pyrrolidonyl-beta-naphthylamide hydrolysis test for the differentiation of members of the families Enterobacteriaceae and Vibrionaceae.

    PubMed Central

    Chagla, A H; Borczyk, A A; Aldom, J E; Dalla Rosa, S; Cole, D D

    1993-01-01

    A simple, rapid, and inexpensive spot test incorporating the substrate pyrrolidonyl naphthylamide was used to examine pyrrolidonyl peptidase activity among 800 bacterial strains belonging to the families Enterobacteriaceae and Vibrionaceae. The pyrrolidonyl naphthylamide test was found to be particularly useful in separating Citrobacter spp. (100% positive) from Salmonella spp. (0.4% positive) and Escherichia coli (0% positive). Furthermore, it would appear to offer a safer alternative to the traditional potassium cyanide test for differentiating citrobacters from salmonellae. PMID:8349781

  4. Pathogenicity of members of the vibrionaceae family to cultured juvenile sablefish.

    PubMed

    Arkoosh, Mary R; Dietrich, Joseph P

    2015-06-01

    Sablefish Anoplopoma fimbria are a prized seafood species due to their high oil content and white flaky flesh. Raising these species in culture can help to provide an important source of protein for humans and relief to declining wild fish populations. Understanding the environmental factors that influence the production of Sablefish is important for successful culturing. The significance of host-pathogen interactions in Sablefish culture and the resulting environmental implications are unknown. Pathogens could potentially cause losses of cultured Sablefish stocks due to disease, while Sablefish cultured in net pens may also serve as reservoirs for pathogens and potentially transmit disease to wild fish species. In this initial study, the susceptibility of juvenile Sablefish to three bacterial pathogens from the family Vibrionaceae was examined. Listonella anguillarum, Vibrio ordalii, and V. splendidus can pose serious economic threats to cultured fish and shellfish. Groups of juvenile Sablefish were exposed to five concentrations of each of the pathogens. Sablefish were susceptible to L. anguillarum, but were resistant to V. ordalii and V. splendidus at exposure concentrations of ≤ 1.32 × 10⁷ CFU/mL and ≤ 3.57 × 10⁶ CFU/mL, respectively. The greatest L. anguillarum concentration examined (8.7 × 10⁶ CFU/mL) resulted in 24% mortality in juvenile Sablefish. A 24% loss of Sablefish stock could significantly influence an aquaculture program. As determined by multiple logistic regression, the survival of Sablefish to L. anguillarum exposure was significantly affected by their body mass, and larger fish had a greater probability of survival. Aquaculture operations could employ various strategies to minimize the loss of juvenile Sablefish by accounting for their size and known susceptibilities to pathogens. PMID:25970236

  5. Phylogenetic relationships of marine bacteria, mainly members of the family Vibrionaceae, determined on the basis of 16S rRNA sequences.

    PubMed

    Kita-Tsukamoto, K; Oyaizu, H; Nanba, K; Simidu, U

    1993-01-01

    The phylogenetic relationships of 50 reference strains, mostly marine bacteria which require Na+ for growth, were determined on the basis of 600 16S rRNA nucleotides by using reverse transcriptase sequencing. Strains belonging to 10 genera were included (four genera of the family Vibrionaceae, the genus Aeromonas of the family Aeromonadaceae, and the genera Alteromonas, Marinomonas, Shewanella, Pseudomonas, and Deleya). The sequences were aligned, the similarity values and evolutionary distance values were determined, and a phylogenetic tree was constructed by using the neighbor-joining method. On the basis of our results, the family Vibrionaceae was separated into at least seven groups (genera and families). Vibrio marinus clearly was on a line of descent that was remote from other vibrios. As determined by the similarity and evolutionary distance values, V. marinus is more distantly related to the family Vibrionaceae than the members of the Aeromonadaceae are. Also, Vibrio cholerae strains formed a separate group with Vibrio mimicus at the genus level. Of 30 species of the Vibrionaceae, 17 formed a large phylogenetic cluster. The genus Listonella was found to be a heterogeneous group, and the species were distributed in various subgroups of the Vibrionaceae. The separation of the family Aeromonadaceae from the family Vibrionaceae and the separation of the genera Marinomonas and Shewanella from the genus Alteromonas were confirmed in this phylogenetic study. However, a marine Pseudomonas species, Pseudomonas nautica, was clearly separated from two terrestrial Pseudomonas species. Each group that was separated by the phylogenetic analysis had characteristic 16S rRNA sequence patterns that were common only to species in that group. Therefore, the characteristic sequences described in this paper may be useful for identification purposes. PMID:8427811

  6. Water quality parameters and total aerobic bacterial and vibrionaceae loads in eastern oysters (Crassostrea virginica) from oyster gardening sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oyster gardening is a practice designed to restore habitat for marine life and to improve water quality. This study determined physical and chemical water quality parameters at two oyster gardening sites in the Delaware Inland Bays and compared them with total aerobic bacteria and Vibrionaceae conc...

  7. Antibacterial Compounds from Marine Vibrionaceae Isolated on a Global Expedition

    PubMed Central

    Wietz, Matthias; Mansson, Maria; Gotfredsen, Charlotte H.; Larsen, Thomas O.; Gram, Lone

    2010-01-01

    On a global research expedition, over 500 bacterial strains inhibitory towards pathogenic bacteria were isolated. Three hundred of the antibacterial strains were assigned to the Vibrionaceae family. The purpose of the present study was to investigate the phylogeny and bioactivity of five Vibrionaceae strains with pronounced antibacterial activity. These were identified as Vibrio coralliilyticus (two strains), V. neptunius (two strains), and Photobacterium halotolerans (one strain) on the basis of housekeeping gene sequences. The two related V. coralliilyticus and V. neptunius strains were isolated from distant oceanic regions. Chemotyping by LC-UV/MS underlined genetic relationships by showing highly similar metabolite profiles for each of the two V. coralliilyticus and V. neptunius strains, respectively, but a unique profile for P. halotolerans. Bioassay-guided fractionation identified two known antibiotics as being responsible for the antibacterial activity; andrimid (from V. coralliilyticus) and holomycin (from P. halotolerans). Despite the isolation of already known antibiotics, our findings show that marine Vibrionaceae are a resource of antibacterial compounds and may have potential for future natural product discovery. PMID:21339958

  8. Fluorogenic Membrane Overlays to Enumerate Total and Fecal Escherichia coli and Total Vibrionaceae in Shellfish and Seawater.

    PubMed

    Richards, Gary P; Watson, Michael A

    2010-01-01

    Three assays were developed to enumerate total and fecal Escherichia coli and total Vibrionaceae in shellfish, seawater, and other foods and environmental samples. Assays involve membrane overlays of overnight colonies on nonselective agar plates to detect beta-glucuronidase and lysyl aminopeptidase activities for E. coli and Vibrionaceae, respectively. Cellulose membranes containing the substrates 4-methylumbeferyl-beta-D-glucuronide (MUG) produced a bright blue fluorescence when overlaid onto E. coli, while L-lysyl-7-amino-4-trifluoromethylcoumarin produced green fluorescent foci when overlaid onto Vibrionaceae family members. A multiplex assay was also developed for simultaneously enumerating total E. coli and total Vibrionaceae in oysters and seawater. Overall, 65% of overlaid E. coli (non-O157:H7) were MUG-positive, compared with 62% as determined by the most-probable-number-MUG assay. The overlays are rapid, simple, and cost effective for quantification purposes. This research provides practical alternatives for monitoring bacterial indicators and potential pathogens in complex samples, including molluscan shellfish. PMID:20396663

  9. Production of Bioactive Secondary Metabolites by Marine Vibrionaceae

    PubMed Central

    Mansson, Maria; Gram, Lone; Larsen, Thomas O.

    2011-01-01

    Bacteria belonging to the Vibrionaceae family are widespread in the marine environment. Today, 128 species of vibrios are known. Several of them are infamous for their pathogenicity or symbiotic relationships. Despite their ability to interact with eukaryotes, the vibrios are greatly underexplored for their ability to produce bioactive secondary metabolites and studies have been limited to only a few species. Most of the compounds isolated from vibrios so far are non-ribosomal peptides or hybrids thereof, with examples of N-containing compounds produced independent of nonribosomal peptide synthetases (NRPS). Though covering a limited chemical space, vibrios produce compounds with attractive biological activities, including antibacterial, anticancer, and antivirulence activities. This review highlights some of the most interesting structures from this group of bacteria. Many compounds found in vibrios have also been isolated from other distantly related bacteria. This cosmopolitan occurrence of metabolites indicates a high incidence of horizontal gene transfer, which raises interesting questions concerning the ecological function of some of these molecules. This account underlines the pending potential for exploring new bacterial sources of bioactive compounds and the challenges related to their investigation. PMID:22131950

  10. Genome-level homology and phylogeny of Vibrionaceae (Gammaproteobacteria: Vibrionales) with three new complete genome sequences

    PubMed Central

    2013-01-01

    Background Phylogenetic hypotheses based on complete genome data are presented for the Gammaproteobacteria family Vibrionaceae. Two taxon samplings are presented: one including all those taxa for which the genome sequences are complete in terms of arrangement (chromosomal location of fragments; 19 taxa) and one for which the genome sequences contain multiple contigs (44 taxa). Analyses are presented under the Maximum Parsimony and Maximum Likelihood optimality criteria for total evidence datasets, the two chromosomes separately, and individual analyses of locally collinear blocks. Three of the genomes included in the 44 taxon dataset, those of Vibrio gazogenes, Salinivibrio costicola, and Aliivibrio logei have been newly sequenced and their genome sequences are documented here. Results Phylogenetic results for the 19-taxon datasets show similar levels of collinear subset of dataset incongruence as a previous study of 22 taxa from the sister family Shewanellaceae, while also echoing the strong phylogenetic performance of random subsets of data also shown in this study. Phylogenetic results for both the 19-taxon and 44-taxon datasets corroborate previous hypotheses about the placement of Photobacterium and Aliivibrio within Vibrionaceae and also highlight problems with how Photobacterium is delimited and indicate that it likely should be dissolved into Vibrio to produce a phylogenetic taxonomy. The 19-taxon and 44-taxon trees based on the large chromosome are congruent for the majority of taxa that are present in both datasets. Analyses of the 44-taxon sampling based on the second, small chromosome are quite different from those based on the large chromosome, which is not surprising given the dramatically divergent nature of the small chromosome and the difficulty in postulating primary homologies. Conclusions The phylogenetic analyses presented here represent the most comprehensive genome-level phylogenetic analyses in terms of taxa and data. Based on the availability of genome data for many bacterial species on GenBank, many other bacterial groups would also be amenable to similar genome-scale phylogenetic analyses even when present in multiple contigs. The result that collinear subsets of data are incongruent with the concatenated dataset and with each other while random data subsets show very little incongruence echoes the result of previous work on Shewanellaceae. The 44-taxon phylogenetic analysis presented here thus represents the future of phylogenomic analyses in scope and complexity. PMID:23578061

  11. Microbial experimental evolution as a novel research approach in the Vibrionaceae and squid-Vibrio symbiosis

    PubMed Central

    Soto, William; Nishiguchi, Michele K.

    2014-01-01

    The Vibrionaceae are a genetically and metabolically diverse family living in aquatic habitats with a great propensity toward developing interactions with eukaryotic microbial and multicellular hosts (as either commensals, pathogens, and mutualists). The Vibrionaceae frequently possess a life history cycle where bacteria are attached to a host in one phase and then another where they are free from their host as either part of the bacterioplankton or adhered to solid substrates such as marine sediment, riverbeds, lakebeds, or floating particulate debris. These two stages in their life history exert quite distinct and separate selection pressures. When bound to solid substrates or to host cells, the Vibrionaceae can also exist as complex biofilms. The association between bioluminescent Vibrio spp. and sepiolid squids (Cephalopoda: Sepiolidae) is an experimentally tractable model to study bacteria and animal host interactions, since the symbionts and squid hosts can be maintained in the laboratory independently of one another. The bacteria can be grown in pure culture and the squid hosts raised gnotobiotically with sterile light organs. The partnership between free-living Vibrio symbionts and axenic squid hatchlings emerging from eggs must be renewed every generation of the cephalopod host. Thus, symbiotic bacteria and animal host can each be studied alone and together in union. Despite virtues provided by the Vibrionaceae and sepiolid squid-Vibrio symbiosis, these assets to evolutionary biology have yet to be fully utilized for microbial experimental evolution. Experimental evolution studies already completed are reviewed, along with exploratory topics for future study. PMID:25538686

  12. Evaluation of the Phoenix 100 ID/AST System and NID Panel for Identification of Enterobacteriaceae, Vibrionaceae, and Commonly Isolated Nonenteric Gram-Negative Bacilli

    PubMed Central

    O'Hara, Caroline M.

    2006-01-01

    The Phoenix 100 ID/AST system (Becton Dickinson Co., Sparks, Md.) is an automated system for the identification and antimicrobial susceptibility testing of bacterial isolates. This system with its negative identification (NID) panel was evaluated for its accuracy in the identification of 507 isolates of the family Enterobacteriaceae, 57 other nonenteric gram-negative isolates that are commonly isolated in clinical microbiology laboratories, and 138 isolates of the family Vibrionaceae. All of the isolates had been characterized by using approximately 48 conventional tube biochemicals. Of the 507 isolates of the Enterobacteriaceae, 456 (89.9%) were correctly identified to the genus and species levels. The five isolates of Proteus penneri required an off-line indole test, as suggested by the system to differentiate them from Proteus vulgaris. The identifications of 20 (3.9%) isolates were correct to the genus level but incorrect at the species level. Two (0.4%) isolates were reported as “no identification.” Misidentifications to the genus and species levels occurred for 29 (5.7%) isolates of the Enterobacteriaceae. These incorrect identifications were spread over 14 different genera. The most common error was the misidentification of Salmonella species. The shortest time for a correct identification was 2 h 8 min. The longest time was 12 h 27 min, for the identification of a Serratia marcescens isolate. Of the 57 isolates of nonenteric gram-negative bacilli (Acinetobacter, Aeromonas, Burkholderia, Plesiomonas, Pseudomonas, and Stenotrophomonas spp.), 48 (84.2%) were correctly identified to the genus and species levels and 7 (12.3%) were correctly identified to the genus level but not to the species level. The average time for a correct identification was 5 h 11 min. Of the Vibrionaceae spp., 123 (89.1%) were correctly identified at the end of the initial incubation period, which averaged 4 h. Based on the findings of this study, the Phoenix 100 ID/AST system NID panel falls short of being an acceptable new method for the identification of the Enterobacteriaceae, Vibrionaceae, and gram-negative nonenteric isolates that are commonly encountered in many hospital microbiology laboratories. PMID:16517878

  13. A new family of bacterial condensins

    PubMed Central

    Petrushenko, Zoya M.; She, Weifeng; Rybenkov, Valentin V.

    2011-01-01

    Condensins play a central role in global chromatin organization. In bacteria, two families of condensins have been identified, the MukBEF and SMC-ScpAB complexes. Only one of the two complexes is usually found in a given species, giving rise to a paradigm that a single condensin organizes bacterial chromosomes. Using sequence analysis, we identified a third family of condensins, MksBEF (MukBEF-like SMC proteins), which is broadly present in diverse bacteria. The proteins appear distantly related to MukBEF, have a similar operon organization and similar predicted secondary structures albeit with notably shorter coiled coils. All three subunits of MksBEF exhibit significant sequence variation and can be divided into a series of overlapping subfamilies. MksBEF often coexists with the SMC-ScpAB, MukBEF and, sometimes, other MksBEFs. In Pseudomonas aeruginosa, both SMC and MksB contribute to faithful chromosome partitioning, with their inactivation leading to increased frequencies of anucleate cells. Moreover, MksBEF can complement anucleate cell formation in SMC-deficient cells. Purified PaMksB showed activities typical for condensins including ATP-modulated DNA binding and condensation. Notably, DNA binding by MksB is negatively regulated by ATP, which sets it apart from other known SMC proteins. Thus, several specialized condensins might be involved in organization of bacterial chromosomes. PMID:21752107

  14. Genomic and Metabolic Profiling of Nonulosonic Acids in Vibrionaceae Reveal Biochemical Phenotypes of Allelic Divergence in Vibrio vulnificus ▿

    PubMed Central

    Lewis, Amanda L.; Lubin, Jean-Bernard; Argade, Shilpa; Naidu, Natasha; Choudhury, Biswa; Boyd, E. Fidelma

    2011-01-01

    Nonulosonic acids (NulOs) encompass a large group of structurally diverse nine-carbon backbone α-keto sugars widely distributed among the three domains of life. Mammals express a specialized version of NulOs called sialic acids, which are displayed in prominent terminal positions of cell surface and secreted glycoconjugates. Within bacteria, the ability to synthesize NulOs has been demonstrated in a number of human pathogens and is phylogenetically widespread. Here we examine the distribution, diversity, evolution, and function of NulO biosynthesis pathways in members of the family Vibrionaceae. Among 27 species of Vibrionaceae examined at the genomic level, 12 species contained nab gene clusters. We document examples of duplication, divergence, horizontal transfer, and recombination of nab gene clusters in different Vibrionaceae lineages. Biochemical analyses, including mass spectrometry, confirmed that many species do, in fact, produce di-N-acetylated NulOs. A library of clinical and environmental isolates of Vibrio vulnificus served as a model for further investigation of nab allele genotypes and levels of NulO expression. The data show that lineage I isolates produce about 20-fold higher levels of NulOs than lineage II isolates. Moreover, nab gene alleles found in a subset of V. vulnificus clinical isolates express 40-fold higher levels of NulOs than nab alleles associated with environmental isolates. Taken together, the data implicate the family Vibrionaceae as a “hot spot” of NulO evolution and suggest that these molecules may have diverse roles in environmental persistence and/or animal virulence. PMID:21724895

  15. Merging Taxonomy with Ecological Population Prediction in a Case Study of Vibrionaceae ▿ †

    PubMed Central

    Preheim, Sarah P.; Timberlake, Sonia; Polz, Martin F.

    2011-01-01

    We synthesized population structure data from three studies that assessed the fine-scale distribution of Vibrionaceae among temporally and spatially distinct environmental categories in coastal seawater and animals. All studies used a dynamic model (AdaptML) to identify phylogenetically cohesive and ecologically distinct bacterial populations and their predicted habitats without relying on a predefined genetic cutoff or relationships to previously named species. Across the three studies, populations were highly overlapping, displaying similar phylogenetic characteristics (identity and diversity), and were predominantly congruent with taxonomic Vibrio species previously characterized as genotypic clusters by multilocus sequence analysis (MLSA). The environmental fidelity of these populations appears high, with 9 out of 12 reproducibly associating with the same predicted (micro)habitats when similar environmental categories were sampled. Overall, this meta-analysis provides information on the habitat predictability and structure of previously described species, demonstrating that MLSA-based taxonomy can, at least in some cases, serve to approximate ecologically cohesive populations. PMID:21873482

  16. Reproducibility of Vibrionaceae population structure in coastal bacterioplankton

    PubMed Central

    Szabo, Gitta; Preheim, Sarah P; Kauffman, Kathryn M; David, Lawrence A; Shapiro, Jesse; Alm, Eric J; Polz, Martin F

    2013-01-01

    How reproducibly microbial populations assemble in the wild remains poorly understood. Here, we assess evidence for ecological specialization and predictability of fine-scale population structure and habitat association in coastal ocean Vibrionaceae across years. We compare Vibrionaceae lifestyles in the bacterioplankton (combinations of free-living, particle, or zooplankton associations) measured using the same sampling scheme in 2006 and 2009 to assess whether the same groups show the same environmental association year after year. This reveals complex dynamics with populations falling primarily into two categories: (i) nearly equally represented in each of the two samplings and (ii) highly skewed, often to an extent that they appear exclusive to one or the other sampling times. Importantly, populations recovered at the same abundance in both samplings occupied highly similar habitats suggesting predictable and robust environmental association while skewed abundances of some populations may be triggered by shifts in ecological conditions. The latter is supported by difference in the composition of large eukaryotic plankton between years, with samples in 2006 being dominated by copepods, and those in 2009 by diatoms. Overall, the comparison supports highly predictable population-habitat linkage but highlights the fact that complex, and often unmeasured, environmental dynamics in habitat occurrence may have strong effects on population dynamics. PMID:23178668

  17. Characterization of the Bacterial Diversity in Indo-West Pacific Loliginid and Sepiolid Squid Light Organs

    PubMed Central

    Guerrero-Ferreira, Ricardo; Gorman, Clayton; Chavez, Alba A.; Willie, Shantell

    2013-01-01

    Loliginid and sepiolid squid light organs are known to host a variety of bacterial species from the family Vibrionaceae, yet little is known about the species diversity and characteristics among different host squids. Here we present a broad-ranging molecular and physiological analysis of the bacteria colonizing light organs in loliginid and sepiolid squids from various field locations of the Indo-West Pacific (Australia and Thailand). Our PCR-RFLP analysis, physiological characterization, carbon utilization profiling, and electron microscopy data indicate that loliginid squid in the Indo-West Pacific carry a consortium of bacterial species from the families Vibrionaceae and Photobacteriaceae. This research also confirms our previous report of the presence of Vibrio harveyi as a member of the bacterial population colonizing light organs in loliginid squid. pyrH sequence data were used to confirm isolate identity, and indicates that Vibrio and Photobacterium comprise most of the light organ colonizers of squids from Australia, confirming previous reports for Australian loliginid and sepiolid squids. In addition, combined phylogenetic analysis of PCR-RFLP and 16S rDNA data from Australian and Thai isolates associated both Photobacterium and Vibrio clades with both loliginid and sepiolid strains, providing support that geographical origin does not correlate with their relatedness. These results indicate that both loliginid and sepiolid squids demonstrate symbiont specificity (Vibrionaceae), but their distribution is more likely due to environmental factors that are present during the infection process. This study adds significantly to the growing evidence for complex and dynamic associations in nature and highlights the importance of exploring symbiotic relationships in which non-virulent strains of pathogenic Vibrio species could establish associations with marine invertebrates. PMID:22885637

  18. A growing family: the expanding universe of the bacterial cytoskeleton

    PubMed Central

    Ingerson-Mahar, Michael; Gitai, Zemer

    2014-01-01

    Cytoskeletal proteins are important mediators of cellular organization in both eukaryotes and bacteria. In the past, cytoskeletal studies have largely focused on three major cytoskeletal families, namely the eukaryotic actin, tubulin, and intermediate filament (IF) proteins and their bacterial homologs MreB, FtsZ, and crescentin. However, mounting evidence suggests that these proteins represent only the tip of the iceberg, as the cellular cytoskeletal network is far more complex. In bacteria, each of MreB, FtsZ, and crescentin represents only one member of large families of diverse homologs. There are also newly identified bacterial cytoskeletal proteins with no eukaryotic homologs, such as WACA proteins and bactofilins. Furthermore, there are universally conserved proteins, such as the metabolic enzyme CtpS, that assemble into filamentous structures that can be repurposed for structural cytoskeletal functions. Recent studies have also identified an increasing number of eukaryotic cytoskeletal proteins that are unrelated to actin, tubulin, and IFs, such that expanding our understanding of cytoskeletal proteins is advancing the understanding of the cell biology of all organisms. Here, we summarize the recent explosion in the identification of new members of the bacterial cytoskeleton and describe a hypothesis for the evolution of the cytoskeleton from self-assembling enzymes. PMID:22092065

  19. Comparative Analysis of Superintegrons: Engineering Extensive Genetic Diversity in the Vibrionaceae

    PubMed Central

    Rowe-Magnus, Dean A.; Guerout, Anne-Marie; Biskri, Latefa; Bouige, Philippe; Mazel, Didier

    2003-01-01

    Integrons are natural tools for bacterial evolution and innovation. Their involvement in the capture and dissemination of antibiotic-resistance genes among Gram-negative bacteria is well documented. Recently, massive ancestral versions, the superintegrons (SIs), were discovered in the genomes of diverse proteobacterial species. SI gene cassettes with an identifiable activity encode proteins related to simple adaptive functions, including resistance, virulence, and metabolic activities, and their recruitment was interpreted as providing the host with an adaptive advantage. Here, we present extensive comparative analysis of SIs identified among the Vibrionaceae. Each was at least 100 kb in size, reaffirming the participation of SIs in the genome plasticity and heterogeneity of these species. Phylogenetic and localization data supported the sedentary nature of the functional integron platform and its coevolution with the host genome. Conversely, comparative analysis of the SI cassettes was indicative of both a wide range of origin for the entrapped genes and of an active cassette assembly process in these bacterial species. The signature attC sites of each species displayed conserved structural characteristics indicating that symmetry rather than sequence was important in the recognition of such a varied collection of target recombination sequences by a single site-specific recombinase. Our discovery of various addiction module cassettes within each of the different SIs indicates a possible role for them in the overall stability of large integron cassette arrays. [Supplemental material is available online at www.genome.org. The sequence data from this study have been submitted to GenBank under accession nos. listed in Table 1.] PMID:12618374

  20. Associations and dynamics of Vibrionaceae in the environment, from the genus to the population level

    PubMed Central

    Takemura, Alison F.; Chien, Diana M.; Polz, Martin F.

    2013-01-01

    The Vibrionaceae, which encompasses several potential pathogens, including V. cholerae, the causative agent of cholera, and V. vulnificus, the deadliest seafood-borne pathogen, are a well-studied family of marine bacteria that thrive in diverse habitats. To elucidate the environmental conditions under which vibrios proliferate, numerous studies have examined correlations with bulk environmental variables—e.g., temperature, salinity, nitrogen, and phosphate—and association with potential host organisms. However, how meaningful these environmental associations are remains unclear because data are fragmented across studies with variable sampling and analysis methods. Here, we synthesize findings about Vibrio correlations and physical associations using a framework of increasingly fine environmental and taxonomic scales, to better understand their dynamics in the wild. We first conduct a meta-analysis to determine trends with respect to bulk water environmental variables, and find that while temperature and salinity are generally strongly predictive correlates, other parameters are inconsistent and overall patterns depend on taxonomic resolution. Based on the hypothesis that dynamics may better correlate with more narrowly defined niches, we review evidence for specific association with plants, algae, zooplankton, and animals. We find that Vibrio are attached to many organisms, though evidence for enrichment compared to the water column is often lacking. Additionally, contrary to the notion that they flourish predominantly while attached, Vibrio can have, at least temporarily, a free-living lifestyle and even engage in massive blooms. Fine-scale sampling from the water column has enabled identification of such lifestyle preferences for ecologically cohesive populations, and future efforts will benefit from similar analysis at fine genetic and environmental sampling scales to describe the conditions, habitats, and resources shaping Vibrio dynamics. PMID:24575082

  1. Fluorogenic membrane overlays to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and seawater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three assays were developed to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and other foods and in seawater and other environmental samples. Assays involve membrane overlays of overnight colonies on non-selective agar plates to detect ß-glucuronidase and lysyl am...

  2. Comparison of a fungal (family I) and bacterial (family II) cellulose-binding domain.

    PubMed Central

    Tomme, P; Driver, D P; Amandoron, E A; Miller, R C; Antony, R; Warren, J; Kilburn, D G

    1995-01-01

    A family II cellulose-binding domain (CBD) of an exoglucanase/xylanase (Cex) from the bacterium Cellulomonas fimi was replaced with the family I CBD of cellobiohydrolase I (CbhI) from the fungus Trichoderma reesei. Expression of the hybrid gene in Escherichia coli yielded up to 50 mg of the hybrid protein, CexCBDCbhI, per liter of culture supernatant. The hybrid was purified to homogeneity by affinity chromatography on cellulose. The relative association constants (Kr) for the binding of Cex, CexCBDCbhI, the catalytic domain of Cex (p33), and CbhI to bacterial microcrystalline cellulose (BMCC) were 14.9, 7.8, 0.8, and 10.6 liters g-1, respectively. Cex and CexCBDCbhI had similar substrate specificities and similar activities on crystalline and amorphous cellulose. Both released predominantly cellobiose and cellotriose from amorphous cellulose. CexCBDCbhI was two to three times less active than Cex on BMCC, but significantly more active than Cex on soluble cellulose and on xylan. Unlike Cex, the hybrid protein neither bound to alpha-chitin nor released small particles from dewaxed cotton fibers. PMID:7635821

  3. Jellyfish Modulate Bacterial Dynamic and Community Structure

    PubMed Central

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

    2012-01-01

    Jellyfish blooms have increased in coastal areas around the world and the outbreaks have become longer and more frequent over the past few decades. The Mediterranean Sea is among the heavily affected regions and the common bloom - forming taxa are scyphozoans Aurelia aurita s.l., Pelagia noctiluca, and Rhizostoma pulmo. Jellyfish have few natural predators, therefore their carcasses at the termination of a bloom represent an organic-rich substrate that supports rapid bacterial growth, and may have a large impact on the surrounding environment. The focus of this study was to explore whether jellyfish substrate have an impact on bacterial community phylotype selection. We conducted in situ jellyfish - enrichment experiment with three different jellyfish species. Bacterial dynamic together with nutrients were monitored to assess decaying jellyfish-bacteria dynamics. Our results show that jellyfish biomass is characterized by protein rich organic matter, which is highly bioavailable to ‘jellyfish - associated’ and ‘free - living’ bacteria, and triggers rapid shifts in bacterial population dynamics and composition. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis, we observed a rapid shift in community composition from unculturable Alphaproteobacteria to culturable species of Gammaproteobacteria and Flavobacteria. The results of sequence analyses of bacterial isolates and of total bacterial community determined by culture independent genetic analysis showed the dominance of the Pseudoalteromonadaceae and the Vibrionaceae families. Elevated levels of dissolved proteins, dissolved organic and inorganic nutrient release, bacterial abundance and carbon production as well as ammonium concentrations characterized the degradation process. The biochemical composition of jellyfish species may influence changes in the amount of accumulated dissolved organic and inorganic nutrients. Our results can contribute insights into possible changes in bacterial population dynamics and nutrient pathways following jellyfish blooms which have important implications for ecology of coastal waters. PMID:22745726

  4. Jellyfish modulate bacterial dynamic and community structure.

    PubMed

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

    2012-01-01

    Jellyfish blooms have increased in coastal areas around the world and the outbreaks have become longer and more frequent over the past few decades. The Mediterranean Sea is among the heavily affected regions and the common bloom-forming taxa are scyphozoans Aurelia aurita s.l., Pelagia noctiluca, and Rhizostoma pulmo. Jellyfish have few natural predators, therefore their carcasses at the termination of a bloom represent an organic-rich substrate that supports rapid bacterial growth, and may have a large impact on the surrounding environment. The focus of this study was to explore whether jellyfish substrate have an impact on bacterial community phylotype selection. We conducted in situ jellyfish-enrichment experiment with three different jellyfish species. Bacterial dynamic together with nutrients were monitored to assess decaying jellyfish-bacteria dynamics. Our results show that jellyfish biomass is characterized by protein rich organic matter, which is highly bioavailable to 'jellyfish-associated' and 'free-living' bacteria, and triggers rapid shifts in bacterial population dynamics and composition. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis, we observed a rapid shift in community composition from unculturable Alphaproteobacteria to culturable species of Gammaproteobacteria and Flavobacteria. The results of sequence analyses of bacterial isolates and of total bacterial community determined by culture independent genetic analysis showed the dominance of the Pseudoalteromonadaceae and the Vibrionaceae families. Elevated levels of dissolved proteins, dissolved organic and inorganic nutrient release, bacterial abundance and carbon production as well as ammonium concentrations characterized the degradation process. The biochemical composition of jellyfish species may influence changes in the amount of accumulated dissolved organic and inorganic nutrients. Our results can contribute insights into possible changes in bacterial population dynamics and nutrient pathways following jellyfish blooms which have important implications for ecology of coastal waters. PMID:22745726

  5. Linkage, Mobility, and Selfishness in the MazF Family of Bacterial Toxins: A Snapshot of Bacterial Evolution

    PubMed Central

    Chopra, Nikita; Saumitra; Pathak, Abhinandan; Bhatnagar, Rakesh; Bhatnagar, Sonika

    2013-01-01

    Prokaryotic MazF family toxins cooccur with cognate antitoxins having divergent DNA-binding folds and can be of chromosomal or plasmid origin. Sequence similarity search was carried out to identify the Toxin–Antitoxin (TA) operons of MazF family followed by sequence analysis and phylogenetic studies. The genomic DNA upstream of the TA operons was searched for the presence of regulatory motifs. The MazF family toxins showed a conserved hydrophobic pocket in a multibinding site and are present in pathogenic bacteria. The toxins of the MazF family are associated with four main types of cognate antitoxin partners and cluster as a subfamily on the branches of the phylogenetic tree. This indicates that transmission of the entire operon is the dominant mode of inheritance. The plasmid borne TA modules were interspersed between the chromosomal TA modules of the same subfamily, compatible with a frequent interchange of TA genes between the chromosome and the plasmid akin to that observed for antibiotic resistance gens. The split network of the MazF family toxins showed the AbrB-linked toxins as a hub of horizontal gene transfer. Distinct motifs are present in the upstream region of each subfamily. The presence of MazF family TA modules in pathogenic bacteria and identification of a conserved binding pocket are significant for the development of novel antibacterials to disrupt the TA interaction. However, the role of TAs in stress resistance needs to be established. Phylogenetic studies provide insight into the evolution of MazF family TAs and effect on the bacterial genome. PMID:24265503

  6. A widespread family of bacterial cell wall assembly proteins

    PubMed Central

    Kawai, Yoshikazu; Marles-Wright, Jon; Cleverley, Robert M; Emmins, Robyn; Ishikawa, Shu; Kuwano, Masayoshi; Heinz, Nadja; Bui, Nhat Khai; Hoyland, Christopher N; Ogasawara, Naotake; Lewis, Richard J; Vollmer, Waldemar; Daniel, Richard A; Errington, Jeff

    2011-01-01

    Teichoic acids and acidic capsular polysaccharides are major anionic cell wall polymers (APs) in many bacteria, with various critical cell functions, including maintenance of cell shape and structural integrity, charge and cation homeostasis, and multiple aspects of pathogenesis. We have identified the widespread LytR–Cps2A–Psr (LCP) protein family, of previously unknown function, as novel enzymes required for AP synthesis. Structural and biochemical analysis of several LCP proteins suggest that they carry out the final step of transferring APs from their lipid-linked precursor to cell wall peptidoglycan (PG). In Bacillus subtilis, LCP proteins are found in association with the MreB cytoskeleton, suggesting that MreB proteins coordinate the insertion of the major polymers, PG and AP, into the cell wall. PMID:21964069

  7. Bacterial profiling of White Plague Disease in a comparative coral species framework

    PubMed Central

    Roder, Cornelia; Arif, Chatchanit; Bayer, Till; Aranda, Manuel; Daniels, Camille; Shibl, Ahmed; Chavanich, Suchana; Voolstra, Christian R

    2014-01-01

    Coral reefs are threatened throughout the world. A major factor contributing to their decline is outbreaks and propagation of coral diseases. Due to the complexity of coral-associated microbe communities, little is understood in terms of disease agents, hosts and vectors. It is known that compromised health in corals is correlated with shifts in bacterial assemblages colonizing coral mucus and tissue. However, general disease patterns remain, to a large extent, ambiguous as comparative studies over species, regions, or diseases are scarce. Here, we compare bacterial assemblages of samples from healthy (HH) colonies and such displaying signs of White Plague Disease (WPD) of two different coral species (Pavona duerdeni and Porites lutea) from the same reef in Koh Tao, Thailand, using 16S rRNA gene microarrays. In line with other studies, we found an increase of bacterial diversity in diseased (DD) corals, and a higher abundance of taxa from the families that include known coral pathogens (Alteromonadaceae, Rhodobacteraceae, Vibrionaceae). In our comparative framework analysis, we found differences in microbial assemblages between coral species and coral health states. Notably, patterns of bacterial community structures from HH and DD corals were maintained over species boundaries. Moreover, microbes that differentiated the two coral species did not overlap with microbes that were indicative of HH and DD corals. This suggests that while corals harbor distinct species-specific microbial assemblages, disease-specific bacterial abundance patterns exist that are maintained over coral species boundaries. PMID:23924783

  8. The DSF Family of Cell–Cell Signals: An Expanding Class of Bacterial Virulence Regulators

    PubMed Central

    Ryan, Robert P.; An, Shi-qi; Allan, John H.; McCarthy, Yvonne; Dow, J. Maxwell

    2015-01-01

    Many pathogenic bacteria use cell–cell signaling systems involving the synthesis and perception of diffusible signal molecules to control virulence as a response to cell density or confinement to niches. Bacteria produce signals of diverse structural classes. Signal molecules of the diffusible signal factor (DSF) family are cis-2-unsaturated fatty acids. The paradigm is cis-11-methyl-2-dodecenoic acid from Xanthomonas campestris pv. campestris (Xcc), which controls virulence in this plant pathogen. Although DSF synthesis was thought to be restricted to the xanthomonads, it is now known that structurally related molecules are produced by the unrelated bacteria Burkholderia cenocepacia and Pseudomonas aeruginosa. Furthermore, signaling involving these DSF family members contributes to bacterial virulence, formation of biofilms and antibiotic tolerance in these important human pathogens. Here we review the recent advances in understanding DSF signaling and its regulatory role in different bacteria. These advances include the description of the pathway/mechanism of DSF biosynthesis, identification of novel DSF synthases and new members of the DSF family, the demonstration of a diversity of DSF sensors to include proteins with a Per-Arnt-Sim (PAS) domain and the description of some of the signal transduction mechanisms that impinge on virulence factor expression. In addition, we address the role of DSF family signals in interspecies signaling that modulates the behavior of other microorganisms. Finally, we consider a number of recently reported approaches for the control of bacterial virulence through the modulation of DSF signaling. PMID:26181439

  9. The DSF Family of Cell-Cell Signals: An Expanding Class of Bacterial Virulence Regulators.

    PubMed

    Ryan, Robert P; An, Shi-qi; Allan, John H; McCarthy, Yvonne; Dow, J Maxwell

    2015-07-01

    Many pathogenic bacteria use cell-cell signaling systems involving the synthesis and perception of diffusible signal molecules to control virulence as a response to cell density or confinement to niches. Bacteria produce signals of diverse structural classes. Signal molecules of the diffusible signal factor (DSF) family are cis-2-unsaturated fatty acids. The paradigm is cis-11-methyl-2-dodecenoic acid from Xanthomonas campestris pv. campestris (Xcc), which controls virulence in this plant pathogen. Although DSF synthesis was thought to be restricted to the xanthomonads, it is now known that structurally related molecules are produced by the unrelated bacteria Burkholderia cenocepacia and Pseudomonas aeruginosa. Furthermore, signaling involving these DSF family members contributes to bacterial virulence, formation of biofilms and antibiotic tolerance in these important human pathogens. Here we review the recent advances in understanding DSF signaling and its regulatory role in different bacteria. These advances include the description of the pathway/mechanism of DSF biosynthesis, identification of novel DSF synthases and new members of the DSF family, the demonstration of a diversity of DSF sensors to include proteins with a Per-Arnt-Sim (PAS) domain and the description of some of the signal transduction mechanisms that impinge on virulence factor expression. In addition, we address the role of DSF family signals in interspecies signaling that modulates the behavior of other microorganisms. Finally, we consider a number of recently reported approaches for the control of bacterial virulence through the modulation of DSF signaling. PMID:26181439

  10. Identification of interdomain sequences promoting the intronless evolution of a bacterial protein family.

    PubMed Central

    de Château, M; Björck, L

    1996-01-01

    In the evolution of eukaryotic genes, introns are believed to have played a major role in increasing the probability of favorable duplication events, chance recombinations, and exon shuffling resulting in functional hybrid proteins. As a rule, prokaryotic genes lack introns, and the examples of prokaryotic introns described do not seem to have contributed to gene evolution by exon shuffling. Still, certain protein families in modern bacteria evolve rapidly by recombination of genes, duplication of functional domains, and as shown for protein PAB of the anaerobic bacterial species Peptostreptococcus magnus, by the shuffling of an albumin-binding protein module from group C and G streptococci. Characterization of a protein PAB-related gene in a P. magnus strain with less albumin-binding activity revealed that the shuffled module was missing. Based on this fact and observations made when comparing gene sequences of this family of bacterial surface proteins interacting with albumin and/or immunoglobulin, a model is presented that can explain how this rapid intronless evolution takes place. A new kind of genetic element is introduced: the recer sequence promoting interdomain, in frame recombination and acting as a structure-less flexibility-promoting spacer in the corresponding protein. The data presented also suggest that antibiotics could represent the selective pressure behind the shuffling of protein modules in P. magnus, a member of the indigenous bacterial flora. Images Fig. 1 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:8710897

  11. Genetic functions of the NAIP family of inflammasome receptors for bacterial ligands in mice.

    PubMed

    Zhao, Yue; Shi, Jianjin; Shi, Xuyan; Wang, Yupeng; Wang, Fengchao; Shao, Feng

    2016-05-01

    Biochemical studies suggest that the NAIP family of NLR proteins are cytosolic innate receptors that directly recognize bacterial ligands and trigger NLRC4 inflammasome activation. In this study, we generated Naip5(-/-), Naip1(-/-), and Naip2(-/-) mice and showed that bone marrow macrophages derived from these knockout mice are specifically deficient in detecting bacterial flagellin, the type III secretion system needle, and the rod protein, respectively. Naip1(-/-), Naip2(-/-), and Naip5(-/-) mice also resist lethal inflammasome activation by the corresponding ligand. Furthermore, infections performed in the Naip-deficient macrophages have helped to define the major signal in Legionella pneumophila, Salmonella Typhimurium and Shigella flexneri that is detected by the NAIP/NLRC4 inflammasome. Using an engineered S. Typhimurium infection model, we demonstrate the critical role of NAIPs in clearing bacterial infection and protecting mice from bacterial virulence-induced lethality. These results provide definitive genetic evidence for the important physiological function of NAIPs in antibacterial defense and inflammatory damage-induced lethality in mice. PMID:27114610

  12. Multidrug Efflux Pumps from Enterobacteriaceae, Vibrio cholerae and Staphylococcus aureus Bacterial Food Pathogens

    PubMed Central

    Andersen, Jody L.; He, Gui-Xin; Kakarla, Prathusha; KC, Ranjana; Kumar, Sanath; Lakra, Wazir Singh; Mukherjee, Mun Mun; Ranaweera, Indrika; Shrestha, Ugina; Tran, Thuy; Varela, Manuel F.

    2015-01-01

    Foodborne illnesses caused by bacterial microorganisms are common worldwide and constitute a serious public health concern. In particular, microorganisms belonging to the Enterobacteriaceae and Vibrionaceae families of Gram-negative bacteria, and to the Staphylococcus genus of Gram-positive bacteria are important causative agents of food poisoning and infection in the gastrointestinal tract of humans. Recently, variants of these bacteria have developed resistance to medically important chemotherapeutic agents. Multidrug resistant Escherichia coli, Salmonella enterica, Vibrio cholerae, Enterobacter spp., and Staphylococcus aureus are becoming increasingly recalcitrant to clinical treatment in human patients. Of the various bacterial resistance mechanisms against antimicrobial agents, multidrug efflux pumps comprise a major cause of multiple drug resistance. These multidrug efflux pump systems reside in the biological membrane of the bacteria and actively extrude antimicrobial agents from bacterial cells. This review article summarizes the evolution of these bacterial drug efflux pump systems from a molecular biological standpoint and provides a framework for future work aimed at reducing the conditions that foster dissemination of these multidrug resistant causative agents through human populations. PMID:25635914

  13. Multidrug efflux pumps from Enterobacteriaceae, Vibrio cholerae and Staphylococcus aureus bacterial food pathogens.

    PubMed

    Andersen, Jody L; He, Gui-Xin; Kakarla, Prathusha; K C, Ranjana; Kumar, Sanath; Lakra, Wazir Singh; Mukherjee, Mun Mun; Ranaweera, Indrika; Shrestha, Ugina; Tran, Thuy; Varela, Manuel F

    2015-02-01

    Foodborne illnesses caused by bacterial microorganisms are common worldwide and constitute a serious public health concern. In particular, microorganisms belonging to the Enterobacteriaceae and Vibrionaceae families of Gram-negative bacteria, and to the Staphylococcus genus of Gram-positive bacteria are important causative agents of food poisoning and infection in the gastrointestinal tract of humans. Recently, variants of these bacteria have developed resistance to medically important chemotherapeutic agents. Multidrug resistant Escherichia coli, Salmonella enterica, Vibrio cholerae, Enterobacter spp., and Staphylococcus aureus are becoming increasingly recalcitrant to clinical treatment in human patients. Of the various bacterial resistance mechanisms against antimicrobial agents, multidrug efflux pumps comprise a major cause of multiple drug resistance. These multidrug efflux pump systems reside in the biological membrane of the bacteria and actively extrude antimicrobial agents from bacterial cells. This review article summarizes the evolution of these bacterial drug efflux pump systems from a molecular biological standpoint and provides a framework for future work aimed at reducing the conditions that foster dissemination of these multidrug resistant causative agents through human populations. PMID:25635914

  14. Novel Cyclic di-GMP Effectors of the YajQ Protein Family Control Bacterial Virulence

    PubMed Central

    An, Shi-qi; Caly, Delphine L.; McCarthy, Yvonne; Murdoch, Sarah L.; Ward, Joseph; Febrer, Melanie; Dow, J. Maxwell; Ryan, Robert P.

    2014-01-01

    Bis-(3′,5′) cyclic di-guanylate (cyclic di-GMP) is a key bacterial second messenger that is implicated in the regulation of many critical processes that include motility, biofilm formation and virulence. Cyclic di-GMP influences diverse functions through interaction with a range of effectors. Our knowledge of these effectors and their different regulatory actions is far from complete, however. Here we have used an affinity pull-down assay using cyclic di-GMP-coupled magnetic beads to identify cyclic di-GMP binding proteins in the plant pathogen Xanthomonas campestris pv. campestris (Xcc). This analysis identified XC_3703, a protein of the YajQ family, as a potential cyclic di-GMP receptor. Isothermal titration calorimetry showed that the purified XC_3703 protein bound cyclic di-GMP with a high affinity (Kd∼2 µM). Mutation of XC_3703 led to reduced virulence of Xcc to plants and alteration in biofilm formation. Yeast two-hybrid and far-western analyses showed that XC_3703 was able to interact with XC_2801, a transcription factor of the LysR family. Mutation of XC_2801 and XC_3703 had partially overlapping effects on the transcriptome of Xcc, and both affected virulence. Electromobility shift assays showed that XC_3703 positively affected the binding of XC_2801 to the promoters of target virulence genes, an effect that was reversed by cyclic di-GMP. Genetic and functional analysis of YajQ family members from the human pathogens Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed that they also specifically bound cyclic di-GMP and contributed to virulence in model systems. The findings thus identify a new class of cyclic di-GMP effector that regulates bacterial virulence. PMID:25329577

  15. Glutamine Deamidation and Dysfunction of Ubiquitin/NEDD8 by a Bacterial Effector Family

    PubMed Central

    Cui, Jixin; Yao, Qing; Li, Shan; Ding, Xiaojun; Lu, Qiuhe; Mao, Haibin; Liu, Liping; Zheng, Ning; Chen, She; Shao, Feng

    2011-01-01

    A family of bacterial effectors including CHBP from Burkholderia pseudomallei and Cif from Enteropathogenic E. Coli (EPEC) adopt a functionally important papain-like hydrolytic fold. Here, CHBP is shown to be a potent inhibitor of the eukaryotic ubiquitination pathway. CHBP acts as a deamidase that specifically and efficiently deamidates Gln-40 in ubiquitin and NEDD8 both in vitro and during Burkholderia infection. Deamidated ubiquitin is impaired in supporting ubiquitin-chain synthesis. Cif selectively deamidates NEDD8, which abolishes rather than stimulates the activity of Cullin-RING ubiquitin ligases (CRLs). Ubiquitin-dependent degradation of multiple CRL substrates including key cell cycle regulators and small GTPase RhoA was impaired by Cif in EPEC-infected cells. Mutations of substrate-contacting residues in Cif abolish or attenuate Cif-induced cytopathic phenotypes of cell cycle arrest and actin stress fibers formation. Thus, NEDD8 deamidation might be the molecular mechanism underlying EPEC-induced cytopathic effect. PMID:20688984

  16. Phosphoinositide 3-kinase family in channel catfish and their regulated expression after bacterial infection.

    PubMed

    Li, Zhaoxia; Yao, Jun; Xie, Yangjie; Geng, Xin; Liu, Zhanjiang

    2016-02-01

    The phosphoinositide-3-kinase (PI3Ks) family of lipid kinases is widely conserved from yeast to mammals. In this work, we identified a total of 14 members of the PI3Ks from the channel catfish genome and transcriptome and conducted phylogenetic and syntenic analyses of these genes. The expression profiles after infection with Edwardsiella ictaluri and Flavobacterium columnare were examined to determine the involvement of PI3Ks in immune responses after bacterial infection in catfish. The results indicated that PI3Ks genes including all of the catalytic subunit and several regulatory subunits genes were widely regulated after bacterial infection. The expression patterns were quite different when challenged with different bacteria. The PI3Ks were up-regulated rapidly at the early stage after ESC infection, but their induced expression was much slower, at the middle stage after columnaris infection. RNA-Seq datasets indicated that PI3K genes may be expressed at different levels in different catfish differing in their resistance levels against columnaris. Future studies are required to confirm and validate these observations. Taken together, this study indicated that PI3K genes may be involved as a part of the defense responses of catfish after infections, and they could be one of the determinants for disease resistance. PMID:26772478

  17. Mechanisms of the sialidase and trans-sialidase activities of bacterial sialyltransferases from glycosyltransferase family 80.

    PubMed

    Mehr, Kevin; Withers, Stephen G

    2016-04-01

    Many important biological functions are mediated by complex glycan structures containing the nine-carbon sugar sialic acid (Sia) at terminal, non-reducing positions. Sia are introduced onto glycan structures by enzymes known as sialyltransferases (STs). Bacterial STs from the glycosyltransferase family GT80 are a group of well-studied enzymes used for the synthesis of sialylated glycan structures. While highly efficient at sialyl transfer, these enzymes also demonstrate sialidase and trans-sialidase activities for which there is some debate surrounding the corresponding enzymatic mechanisms. Here we propose a mechanism for STs from the glycosyltransferase family GT80 in which sialidase and trans-sialidase activities occur through reverse sialylation of CMP. The resulting CMP-Sia is then enzymatically hydrolyzed or used as a donor in subsequent ST reactions resulting in sialidase and trans-sialidase activities, respectively. We provide evidence for this mechanism by demonstrating that CMP is required for sialidase and trans-sialidase activities and that its removal with phosphatase ablates activity. We also confirm the formation of CMP-Sia using a coupled enzyme assay. A clear understanding of the sialidase and trans-sialidase mechanisms for this class of enzymes allows for more effective use of these enzymes in the synthesis of glycoconjugates. PMID:26582604

  18. Bacterial origin of a diverse family of UDP-glycosyltransferase genes in the Tetranychus urticae genome.

    PubMed

    Ahn, Seung-Joon; Dermauw, Wannes; Wybouw, Nicky; Heckel, David G; Van Leeuwen, Thomas

    2014-07-01

    UDP-glycosyltransferases (UGTs) catalyze the conjugation of a variety of small lipophilic molecules with uridine diphosphate (UDP) sugars, altering them into more water-soluble metabolites. Thereby, UGTs play an important role in the detoxification of xenobiotics and in the regulation of endobiotics. Recently, the genome sequence was reported for the two-spotted spider mite, Tetranychus urticae, a polyphagous herbivore damaging a number of agricultural crops. Although various gene families implicated in xenobiotic metabolism have been documented in T. urticae, UGTs so far have not. We identified 80 UGT genes in the T. urticae genome, the largest number of UGT genes in a metazoan species reported so far. Phylogenetic analysis revealed that lineage-specific gene expansions increased the diversity of the T. urticae UGT repertoire. Genomic distribution, intron-exon structure and structural motifs in the T. urticae UGTs were also described. In addition, expression profiling after host-plant shifts and in acaricide resistant lines supported an important role for UGT genes in xenobiotic metabolism. Expanded searches of UGTs in other arachnid species (Subphylum Chelicerata), including a spider, a scorpion, two ticks and two predatory mites, unexpectedly revealed the complete absence of UGT genes. However, a centipede (Subphylum Myriapoda) and a water flea and a crayfish (Subphylum Crustacea) contain UGT genes in their genomes similar to insect UGTs, suggesting that the UGT gene family might have been lost early in the Chelicerata lineage and subsequently re-gained in the tetranychid mites. Sequence similarity of T. urticae UGTs and bacterial UGTs and their phylogenetic reconstruction suggest that spider mites acquired UGT genes from bacteria by horizontal gene transfer. Our findings show a unique evolutionary history of the T. urticae UGT gene family among other arthropods and provide important clues to its functions in relation to detoxification and thereby host adaptation. PMID:24727020

  19. Biochemical Roles for Conserved Residues in the Bacterial Fatty Acid-binding Protein Family.

    PubMed

    Broussard, Tyler C; Miller, Darcie J; Jackson, Pamela; Nourse, Amanda; White, Stephen W; Rock, Charles O

    2016-03-18

    Fatty acid kinase (Fak) is a ubiquitous Gram-positive bacterial enzyme consisting of an ATP-binding protein (FakA) that phosphorylates the fatty acid bound to FakB. In Staphylococcus aureus, Fak is a global regulator of virulence factor transcription and is essential for the activation of exogenous fatty acids for incorporation into phospholipids. The 1.2-Å x-ray structure of S. aureus FakB2, activity assays, solution studies, site-directed mutagenesis, and in vivo complementation were used to define the functions of the five conserved residues that define the FakB protein family (Pfam02645). The fatty acid tail is buried within the protein, and the exposed carboxyl group is bound by a Ser-93-fatty acid carboxyl-Thr-61-His-266 hydrogen bond network. The guanidinium of the invariant Arg-170 is positioned to potentially interact with a bound acylphosphate. The reduced thermal denaturation temperatures of the T61A, S93A, and H266A FakB2 mutants illustrate the importance of the hydrogen bond network in protein stability. The FakB2 T61A, S93A, and H266A mutants are 1000-fold less active in the Fak assay, and the R170A mutant is completely inactive. All FakB2 mutants form FakA(FakB2)2 complexes except FakB2(R202A), which is deficient in FakA binding. Allelic replacement shows that strains expressing FakB2 mutants are defective in fatty acid incorporation into phospholipids and virulence gene transcription. These conserved residues are likely to perform the same critical functions in all bacterial fatty acid-binding proteins. PMID:26774272

  20. A genomic perspective on a new bacterial genus and species from the Alcaligenaceae family, Basilea psittacipulmonis

    PubMed Central

    2014-01-01

    Background A novel Gram-negative, non-haemolytic, non-motile, rod-shaped bacterium was discovered in the lungs of a dead parakeet (Melopsittacus undulatus) that was kept in captivity in a petshop in Basel, Switzerland. The organism is described with a chemotaxonomic profile and the nearly complete genome sequence obtained through the assembly of short sequence reads. Results Genome sequence analysis and characterization of respiratory quinones, fatty acids, polar lipids, and biochemical phenotype is presented here. Comparison of gene sequences revealed that the most similar species is Pelistega europaea, with BLAST identities of only 93% to the 16S rDNA gene, 76% identity to the rpoB gene, and a similar GC content (~43%) as the organism isolated from the parakeet, DSM 24701 (40%). The closest full genome sequences are those of Bordetella spp. and Taylorella spp. High-throughput sequencing reads from the Illumina-Solexa platform were assembled with the Edena de novo assembler to form 195 contigs comprising the ~2Mb genome. Genome annotation with RAST, construction of phylogenetic trees with the 16S rDNA (rrs) gene sequence and the rpoB gene, and phylogenetic placement using other highly conserved marker genes with ML Tree all suggest that the bacterial species belongs to the Alcaligenaceae family. Analysis of samples from cages with healthy parakeets suggested that the newly discovered bacterial species is not widespread in parakeet living quarters. Conclusions Classification of this organism in the current taxonomy system requires the formation of a new genus and species. We designate the new genus Basilea and the new species psittacipulmonis. The type strain of Basilea psittacipulmonis is DSM 24701 (= CIP 110308 T, 16S rDNA gene sequence Genbank accession number JX412111 and GI 406042063). PMID:24581117

  1. Diversity of bacterial type II toxin–antitoxin systems: a comprehensive search and functional analysis of novel families

    PubMed Central

    Leplae, Raphaël; Geeraerts, Damien; Hallez, Régis; Guglielmini, Julien; Drèze, Pierre; Van Melderen, Laurence

    2011-01-01

    Type II toxin–antitoxin (TA) systems are generally composed of two genes organized in an operon, encoding a labile antitoxin and a stable toxin. They were first discovered on plasmids where they contribute to plasmid stability by a phenomenon denoted as ‘addiction’, and subsequently in bacterial chromosomes. To discover novel families of antitoxins and toxins, we developed a bioinformatics approach based on the ‘guilt by association’ principle. Extensive experimental validation in Escherichia coli of predicted antitoxins and toxins increased significantly the number of validated systems and defined novel toxin and antitoxin families. Our data suggest that toxin families as well as antitoxin families originate from distinct ancestors that were assembled multiple times during evolution. Toxin and antitoxin families found on plasmids tend to be promiscuous and widespread, indicating that TA systems move through horizontal gene transfer. We propose that due to their addictive properties, TA systems are likely to be maintained in chromosomes even though they do not necessarily confer an advantage to their bacterial hosts. Therefore, addiction might play a major role in the evolutionary success of TA systems both on mobile genetic elements and in bacterial chromosomes. PMID:21422074

  2. The bacterial pathogen Listeria monocytogenes and the interferon family: type I, type II and type III interferons

    PubMed Central

    Dussurget, Olivier; Bierne, Hélène; Cossart, Pascale

    2014-01-01

    Interferons (IFNs) are secreted proteins of the cytokine family that regulate innate and adaptive immune responses to infection. Although the importance of IFNs in the antiviral response has long been appreciated, their role in bacterial infections is more complex and is currently a major focus of investigation. This review summarizes our current knowledge of the role of these cytokines in host defense against the bacterial pathogen Listeria monocytogenes and highlights recent discoveries on the molecular mechanisms evolved by this intracellular bacterium to subvert IFN responses. PMID:24809023

  3. A Bacterial Pathogen Targets a Host Rab-Family GTPase Defense Pathway with a GAP.

    PubMed

    Spanò, Stefania; Gao, Xiang; Hannemann, Sebastian; Lara-Tejero, María; Galán, Jorge E

    2016-02-10

    Cell-autonomous defense mechanisms are potent strategies that protect individual cells against intracellular pathogens. The Rab-family GTPase Rab32 was previously shown to restrict the intracellular human pathogen Salmonella Typhi, but its potential broader role in antimicrobial defense remains unknown. We show that Rab32 represents a general cell-autonomous, antimicrobial defense that is counteracted by two Salmonella effectors. Mice lacking Rab-32 or its nucleotide exchange factor BLOC-3 are permissive to S. Typhi infection and exhibit increased susceptibility to S. Typhimurium. S. Typhimurium counters this defense pathway by delivering two type III secretion effectors, SopD2, a Rab32 GAP, and GtgE, a specific Rab32 protease. An S. Typhimurium mutant strain lacking these two effectors exhibits markedly reduced virulence, which is fully restored in BLOC-3-deficient mice. These results demonstrate that a cell-autonomous, Rab32-dependent host defense pathway plays a central role in the defense against vacuolar pathogens and describe a mechanism evolved by a bacterial pathogen to counter it. PMID:26867180

  4. Crystal structure analysis of a bacterial aryl acylamidase belonging to the amidase signature enzyme family.

    PubMed

    Lee, Saeyoung; Park, Eun-Hye; Ko, Hyeok-Jin; Bang, Won Gi; Kim, Hye-Yeon; Kim, Kyoung Heon; Choi, In-Geol

    2015-11-13

    The atomic structure of a bacterial aryl acylamidase (EC 3.5.1.13; AAA) is reported and structural features are investigated to better understand the catalytic profile of this enzyme. Structures of AAA were determined in its native form and in complex with the analgesic acetanilide, p-acetaminophenol, at 1.70 Å and 1.73 Å resolutions, respectively. The overall structural fold of AAA was identified as an α/β fold class, exhibiting an open twisted β-sheet core surrounded by α-helices. The asymmetric unit contains one AAA molecule and the monomeric form is functionally active. The core structure enclosing the signature sequence region, including the canonical Ser-cisSer-Lys catalytic triad, is conserved in all members of the Amidase Signature enzyme family. The structure of AAA in a complex with its ligand reveals a unique organization in the substrate-binding pocket. The binding pocket consists of two loops (loop1 and loop2) in the amidase signature sequence and one helix (α10) in the non-amidase signature sequence. We identified two residues (Tyr(136) and Thr(330)) that interact with the ligand via water molecules, and a hydrogen-bonding network that explains the catalytic affinity over various aryl acyl compounds. The optimum activity of AAA at pH > 10 suggests that the reaction mechanism employs Lys(84) as the catalytic base to polarize the Ser(187) nucleophile in the catalytic triad. PMID:26454172

  5. Homologs of the Acinetobacter baumannii AceI Transporter Represent a New Family of Bacterial Multidrug Efflux Systems

    PubMed Central

    Liu, Qi; Henderson, Peter J. F.

    2015-01-01

    ABSTRACT Multidrug efflux systems are a major cause of resistance to antimicrobials in bacteria, including those pathogenic to humans, animals, and plants. These proteins are ubiquitous in these pathogens, and five families of bacterial multidrug efflux systems have been identified to date. By using transcriptomic and biochemical analyses, we recently identified the novel AceI (Acinetobacter chlorhexidine efflux) protein from Acinetobacter baumannii that conferred resistance to the biocide chlorhexidine, via an active efflux mechanism. Proteins homologous to AceI are encoded in the genomes of many other bacterial species and are particularly prominent within proteobacterial lineages. In this study, we expressed 23 homologs of AceI and examined their resistance and/or transport profiles. MIC analyses demonstrated that, like AceI, many of the homologs conferred resistance to chlorhexidine. Many of the AceI homologs conferred resistance to additional biocides, including benzalkonium, dequalinium, proflavine, and acriflavine. We conducted fluorimetric transport assays using the AceI homolog from Vibrio parahaemolyticus and confirmed that resistance to both proflavine and acriflavine was mediated by an active efflux mechanism. These results show that this group of AceI homologs represent a new family of bacterial multidrug efflux pumps, which we have designated the proteobacterial antimicrobial compound efflux (PACE) family of transport proteins. PMID:25670776

  6. A diverse set of family 48 bacterial glycoside hydrolase cellulases created by structure-guided recombination.

    PubMed

    Smith, Matthew A; Rentmeister, Andrea; Snow, Christopher D; Wu, Timothy; Farrow, Mary F; Mingardon, Florence; Arnold, Frances H

    2012-12-01

    Sequence diversity within a family of functional enzymes provides a platform for elucidating structure-function relationships and for protein engineering to improve properties important for applications. Access to nature's vast sequence diversity is often limited by the fact that only a few enzymes have been characterized in a given family. Here, we recombined the catalytic domains of three glycoside hydrolase family 48 bacterial cellulases (Cel48; EC 3.2.1.176) - Clostridium cellulolyticum CelF, Clostridium stercorarium CelY, and Clostridium thermocellum CelS - to create a diverse library of Cel48 enzymes with an average of 106 mutations from the closest native enzyme. Within this set, we found large variations in properties such as the functional temperature range, stability, and specific activity on crystalline cellulose. We showed that functional status and stability were predictable from simple linear models of the sequence-property data: recombined protein fragments contributed additively to these properties in a given chimera. Using this, we correctly predicted sequences that were as stable as any of the native Cel48 enzymes described to date. The characterization of 60 active Cel48 chimeras expands the number of characterized Cel48 enzymes from 13 to 73. Our work illustrates the role that structure-guided recombination can play in helping to identify sequence-function relationships within a family of enzymes by supplementing natural diversity with synthetic diversity. PMID:23075376

  7. Two novel human members of an emerging mammalian gene family related to mono-ADP-ribosylating bacterial toxins

    SciTech Connect

    Koch-Nolte, F.; Haag, F.; Braren, R.

    1997-02-01

    Mono-ADP-ribosylation is one of the posttranslational protein modifications regulating cellular metabolism, e.g., nitrogen fixation, in prokaryotes. Several bacterial toxins mono-ADP-ribosylate and inactivate specific proteins in their animal hosts. Recently, two mammalian GPI-anchored cell surface enzymes with similar activities were cloned (designated ART1 and ART2). We have now identified six related expressed sequence tags (ESTs) in the public database and cloned the two novel human genes from which these are derived (designated ART3 and ART4). The deduced amino acid sequences of the predicted gene products show 28% sequence identity to one another and 32-41% identity vs the muscle and T cell enzymes. They contain signal peptide sequences characteristic of GPI anchorage. Southern Zoo blot analyses suggest the presence of related genes in other mammalian species. By PCR screening of somatic cell hybrids and by in situ hybridization, we have mapped the two genes to human chromosomes 4p14-p15.l and 12q13.2- q13.3. Northern blot analyses show that these genes are specifically expressed in testis and spleen, respectively. Comparison of genomic and cDNA sequences reveals a conserved exon/intron structure, with an unusually large exon encoding the predicted mature membrane proteins. Secondary structure prediction analyses indicate conserved motifs and amino acid residues consistent with a common ancestry of this emerging mammalian enzyme family and bacterial mono(ADP-ribosyl)transferases. It is possible that the four human gene family members identified so far represent the {open_quotes}tip of an iceberg,{close_quote} i.e., a larger family of enzymes that influences the function of target proteins via mono-ADP-ribosylation. 35 refs., 4 figs.

  8. CPDadh: A new peptidase family homologous to the cysteine protease domain in bacterial MARTX toxins

    PubMed Central

    Pei, Jimin; Lupardus, Patrick J; Garcia, K Christopher; Grishin, Nick V

    2009-01-01

    A cysteine protease domain (CPD) has been recently discovered in a group of multifunctional, autoprocessing RTX toxins (MARTX) and Clostridium difficile toxins A and B. These CPDs (referred to as CPDmartx) autocleave the toxins to release domains with toxic effects inside host cells. We report identification and computational analysis of CPDadh, a new cysteine peptidase family homologous to CPDmartx. CPDadh and CPDmartx share a Rossmann-like structural core and conserved catalytic residues. In bacteria, domains of the CPDadh family are present at the N-termini of a diverse group of putative cell-cell interaction proteins and at the C-termini of some RHS (recombination hot spot) proteins. In eukaryotes, catalytically inactive members of the CPDadh family are found in cell surface protein NELF (nasal embryonic LHRH factor) and some putative signaling proteins. PMID:19309740

  9. Rethinking the roles of CRP, cAMP, and sugar-mediated global regulation in the Vibrionaceae.

    PubMed

    Colton, Deanna M; Stabb, Eric V

    2016-02-01

    Many proteobacteria modulate a suite of catabolic genes using the second messenger cyclic 3', 5'-AMP (cAMP) and the cAMP receptor protein (CRP). Together, the cAMP-CRP complex regulates target promoters, usually by activating transcription. In the canonical model, the phosphotransferase system (PTS), and in particular the EIIA(Glc) component for glucose uptake, provides a mechanistic link that modulates cAMP levels depending on glucose availability, resulting in more cAMP and activation of alternative catabolic pathways when glucose is unavailable. Within the Vibrionaceae, cAMP-CRP appears to play the classical role in modulating metabolic pathways; however, it also controls functions involved in natural competence, bioluminescence, pheromone signaling, and colonization of animal hosts. For this group of marine bacteria, chitin is an ecologically relevant resource, and chitin's monomeric sugar N-acetylglucosamine (NAG) supports robust growth while also triggering regulatory responses. Recent studies with Vibrio fischeri indicate that NAG and glucose uptake share EIIA(Glc), yet the responses of cAMP-CRP to these two carbon sources are starkly different. Moreover, control of cAMP levels appears to be more dominantly controlled by export and degradation. Perhaps more surprisingly, although CRP may require cAMP, its activity can be controlled in response to glucose by a mechanism independent of cAMP levels. Future studies in this area promise to shed new light on the role of cAMP and CRP. PMID:26215147

  10. IDENTIFICATION OF NICOTINAMIDE MONONUCLEOTIDE DEAMIDASE OF THE BACTERIAL PYRIDINE NUCLEOTIDE CYCLE REVEALS A NOVEL BROADLY CONSERVED AMIDOHYDROLASE FAMILY

    SciTech Connect

    Galeazzi, Luca; Bocci, Paolo; Amici, Adolfo; Brunetti, Lucia; Ruggieri, Silverio; Romine, Margaret F.; Reed, Samantha B.; Osterman, Andrei; Rodionov, Dmitry A.; Sorci, Leonardo; Raffaelli, Nadia

    2011-09-27

    The pyridine nucleotide cycle (PNC) is a network of salvage and recycling routes maintaining homeostasis of NAD(P) cofactor pool in the cell. Nicotinamide mononucleotide (NMN) deamidase (EC 3.5.1.42), one of the key enzymes of the bacterial PNC was originally described in Enterobacteria, but the corresponding gene eluded identification for over 30 years. A genomics-based reconstruction of NAD metabolism across hundreds bacterial species suggested that NMN deamidase reaction is the only possible way of nicotinamide salvage in the marine bacterium Shewanella oneidensis. This prediction was verified via purification of native NMN deamidase from S. oneidensis followed by the identification of the respective gene, termed pncC. Enzymatic characterization of the PncC protein, as well as phenotype analysis of deletion mutants, confirmed its proposed biochemical and physiological function in S. oneidensis. Of the three PncC homologs present in E. coli, NMN deamidase activity was confirmed only for the recombinant purified product of the ygaD gene. A comparative analysis at the level of sequence and three dimensional structure, which is available for one of the PncC family member, shows no homology with any previously described amidohydrolases. Multiple alignment analysis of functional and non functional PncC homologs, together with NMN docking experiments, allowed us to tentatively identify the active site area and conserved residues therein. An observed broad phylogenomic distribution of predicted functional PncCs in bacterial kingdom is consistent with a possible role in detoxification of NMN, resulting from NAD utilization by DNA ligase.

  11. Sphingomonas paucimobilis beta-glucosidase Bgl1: a member of a new bacterial subfamily in glycoside hydrolase family 1.

    PubMed Central

    Marques, Ana Rita; Coutinho, Pedro M; Videira, Paula; Fialho, Arsénio M; Sá-Correia, Isabel

    2003-01-01

    The Sphingomonas paucimobilis beta-glucosidase Bgl1 is encoded by the bgl1 gene, associated with an 1308 bp open reading frame. The deduced protein has a potential signal peptide of 24 amino acids in the N-terminal region, and experimental evidence is consistent with the processing and export of the Bgl1 protein through the inner membrane to the periplasmic space. A His(6)-tagged 44.3 kDa protein was over-produced in the cytosol of Escherichia coli from a recombinant plasmid, which contained the S. paucimobilis bgl1 gene lacking the region encoding the putative signal peptide. Mature beta-glucosidase Bgl1 is specific for aryl-beta-glucosides and has no apparent activity with oligosaccharides derived from cellulose hydrolysis and other saccharides. A structure-based alignment established structural relations between S. paucimobilis Bgl1 and other members of the glycoside hydrolase (GH) family 1 enzymes. At subsite -1, the conserved residues required for catalysis by GH1 enzymes are present in Bgl1 with only minor differences. Major differences are found at subsite +1, the aglycone binding site. This alignment seeded a sequence-based phylogenetic analysis of GH1 enzymes, revealing an absence of horizontal transfer between phyla. Bootstrap analysis supported the definition of subfamilies and revealed that Bgl1, the first characterized beta-glucosidase from the genus Sphingomonas, represents a very divergent bacterial subfamily, closer to archaeal subfamilies than to others of bacterial origin. PMID:12444924

  12. Identification of novel members of the bacterial azoreductase family in Pseudomonas aeruginosa.

    PubMed

    Crescente, Vincenzo; Holland, Sinead M; Kashyap, Sapna; Polycarpou, Elena; Sim, Edith; Ryan, Ali

    2016-03-01

    Azoreductases are a family of diverse enzymes found in many pathogenic bacteria as well as distant homologues being present in eukarya. In addition to having azoreductase activity, these enzymes are also suggested to have NAD(P)H quinone oxidoreductase (NQO) activity which leads to a proposed role in plant pathogenesis. Azoreductases have also been suggested to play a role in the mammalian pathogenesis of Pseudomonas aeruginosa. In view of the importance of P. aeruginosa as a pathogen, we therefore characterized recombinant enzymes following expression of a group of putative azoreductase genes from P. aeruginosa expressed in Escherichia coli. The enzymes include members of the arsenic-resistance protein H (ArsH), tryptophan repressor-binding protein A (WrbA), modulator of drug activity B (MdaB) and YieF families. The ArsH, MdaB and YieF family members all show azoreductase and NQO activities. In contrast, WrbA is the first enzyme to show NQO activity but does not reduce any of the 11 azo compounds tested under a wide range of conditions. These studies will allow further investigation of the possible role of these enzymes in the pathogenesis of P. aeruginosa. PMID:26621870

  13. [Bacterial synthesis, purification, and solubilization of transmembrane segments of ErbB family members].

    PubMed

    Goncharuk, M V; Shul'ga, A A; Ermoliuk, Ia S; Tkach, E N; Goncharuk, S A; Pustovalova, Iu E; Mineev, K S; Bocharov, É V; Maslennikov, I V; Arsen'ev, A S; Kirpichnikov, M P

    2011-01-01

    A family of epidermal growth factor receptors, ErbB, represents an important class of receptor tyrosine kinases, playing a leading role in cellular growth, development and differentiation. Transmembrane domains of these receptors transduce biochemical signals across plasma membrane via lateral homo- and heterodimerization. Relatively small size of complexes of ErbB transmembrane domains with detergents or lipids allows one to study their detailed spatial structure using three-dimensional heteronuclear high-resolution NMR spectroscopy. Here, we describe the effective expression system and purification procedure for preparative-scale production of transmembrane peptides from four representatives of ErbB family, ErbB1, ErbB2, ErbB3, ErbB4, for structural studies. The recombinant peptides were produced in Escherichia coli BL21(DE3)pLysS as C-terminal extensions of thioredoxin A. The fusion protein cleavage was accomplished with the light subunit of human enterokinase. Several (10-30) milligrams of purified isotope-labeled transmembrane peptides were isolated with the use of a simple and convenient procedure, which consists of consecutive steps of immobilized metal affinity chromatography and cation-exchange chromatography. The purified peptides were reconstituted in lipid/detergent environment (micelles or bicelles) and characterized using dynamic light scattering, CD and NMR spectroscopy. The data obtained indicate that the purified ErbB transmembrane peptides are suitable for structural and dynamic studies of their homo- and heterodimer complexes using high resolution NMR spectroscopy. PMID:22393787

  14. Comparative biology and expression of TENP, an egg protein related to the bacterial permeability-increasing family of proteins.

    PubMed

    Whenham, Natasha; Wilson, Peter W; Bain, Maureen M; Stevenson, Lynn; Dunn, Ian C

    2014-03-15

    The 'transiently expressed in neural precursors' (TENP) gene product is a member of the bacterial/permeability-increasing (BPI) family of antimicrobial proteins but was first identified as having a role in an early neurological event occurring in post-mitotic cells. However, recent characterisation of the egg white proteome has shown that TENP is an important egg component constituting ~0.1-0.5% of the total protein and suggesting it is expressed in the adult oviduct. In this study we confirmed quantitatively that the expression of TENP is largely confined to the tubular glands of the magnum of the oviduct, where egg white synthesis occurs, with around 10,000 times more expression than in the embryo where TENP was first identified. TENP expression is significantly increased with the administration of oestrogen or progesterone (P<0.001) and is reduced in regressed oviducts (P<0.001) demonstrating gonadal steroid control, typical of an oviduct and egg specific gene. A putative translational start site for TENP has been characterised and the evidence indicates that it is expressed as one predominant transcript. In comparison with the published sequence, insertion and deletion events have been identified causing a partial frame-shift that results in an altered amino acid sequence to that previously documented. TENP is conserved across divergent avian species being found in chicken, turkey, duck and zebra finch and its expression profile confirmed in both chicken and duck. Similarity searches have shown homology with the BPI-like family of innate immune genes, particularly with palate, lung and nasal epithelial clone (PLUNC) members of this family. We therefore believe that at least in adults the role of TENP is as a major component of egg, particularly the white and it is probable that it contributes to its antimicrobial function. PMID:24418699

  15. Seasonal Incidence of Autochthonous Antagonistic Roseobacter spp. and Vibrionaceae Strains in a Turbot Larva (Scophthalmus maximus) Rearing System

    PubMed Central

    Hjelm, Mette; Riaza, Ana; Formoso, Fernanda; Melchiorsen, Jette; Gram, Lone

    2004-01-01

    Bacteria inhibitory to fish larval pathogenic bacteria were isolated from two turbot larva rearing farms over a 1-year period. Samples were taken from the rearing site, e.g., tank walls, water, and feed for larvae, and bacteria with antagonistic activity against Vibrio anguillarum were isolated using a replica plating assay. Approximately 19,000 colonies were replica plated from marine agar plates, and 341 strains were isolated from colonies causing clearing zones in a layer of V. anguillarum. When tested in a well diffusion agar assay, 173 strains retained the antibacterial activity against V. anguillarum and Vibrio splendidus. Biochemical tests identified 132 strains as Roseobacter spp. and 31 as Vibrionaceae strains. Partial sequencing of the 16S rRNA gene of three strains confirmed the identification as Roseobacter gallaeciensis. Roseobacter spp. were especially isolated in the spring and early summer months. Subtyping of the 132 Roseobacter spp. strains by randomly amplified polymorphic DNA with two primers revealed that the strains formed a very homogeneous group. Hence, it appears that the same subtype was present at both fish farms and persisted during the 1-year survey. This indicates either a common, regular source of the subtype or the possibility that a particular subtype has established itself in some areas of the fish farm. Thirty-one antagonists were identified as Vibrio spp., and 18 of these were V. anguillarum but not serotype O1 or O2. Roseobacter spp. strains were, in particular, isolated from the larval tank walls, and it may be possible to establish an antagonistic, beneficial microflora in the rearing environment of turbot larvae and thereby limit survival of pathogenic bacteria. PMID:15574928

  16. On the solution properties of bacterial polysaccharides of the gellan family.

    PubMed

    Campana, S; Ganter, J; Milas, M; Rinaudo, M

    1992-07-01

    The influence of side chains and substituents on the polyelectrolyte behaviour of aqueous solutions of polysaccharides of the gellan family has been studied. The results of conductimetric and potentiometric titrations suggest that each of these polysaccharides adopts a double-helix conformation. Deacetylation destabilises the helix of rhamsan and gellan, and optical rotation data confirm these results. The side chain in rhamsan is more flexible and is remote from the carboxylate groups, and the behavior of this polysaccharide is similar to that of gellan. Gelation of deacetylated rhamsan occurs in the presence of calcium ions. The intrinsic viscosity as a function of ionic strength depends on the structure of the polysaccharide and on the presence of acetyl groups. PMID:1394322

  17. Structural and biochemical characterization of novel bacterial α-galactosidases belonging to glycoside hydrolase family 31.

    PubMed

    Miyazaki, Takatsugu; Ishizaki, Yuichi; Ichikawa, Megumi; Nishikawa, Atsushi; Tonozuka, Takashi

    2015-07-01

    Glycoside hydrolase family 31 (GH31) proteins have been reportedly identified as exo-α-glycosidases with activity for α-glucosides and α-xylosides. We focused on a GH31 subfamily, which contains proteins with low sequence identity (<24%) to the previously reported GH31 glycosidases and characterized two enzymes from Pedobacter heparinus and Pedobacter saltans. The enzymes unexpectedly exhibited α-galactosidase activity, but were not active on α-glucosides and α-xylosides. The crystal structures of one of the enzymes, PsGal31A, in unliganded form and in complexes with D-galactose or L-fucose and the catalytic nucleophile mutant in unliganded form and in complex with p-nitrophenyl-α-D-galactopyranoside, were determined at 1.85-2.30 Å (1 Å=0.1 nm) resolution. The overall structure of PsGal31A contains four domains and the catalytic domain adopts a (β/α)8-barrel fold that resembles the structures of other GH31 enzymes. Two catalytic aspartic acid residues are structurally conserved in the enzymes, whereas most residues forming the active site differ from those of GH31 α-glucosidases and α-xylosidases. PsGal31A forms a dimer via a unique loop that is not conserved in other reported GH31 enzymes; this loop is involved in its aglycone specificity and in binding L-fucose. Considering potential genes for α-L-fucosidases and carbohydrate-related proteins within the vicinity of Pedobacter Gal31, the identified Gal31 enzymes are likely to function in a novel sugar degradation system. This is the first report of α-galactosidases which belong to GH31 family. PMID:25942325

  18. Expression and crystallization of a bacterial glycoside hydrolase family 116 β-glucosidase from Thermoanaerobacterium xylanolyticum.

    PubMed

    Sansenya, Sompong; Mutoh, Risa; Charoenwattanasatien, Ratana; Kurisu, Genji; Ketudat Cairns, James R

    2015-01-01

    The Thermoanaerobacterium xylanolyticum gene product TxGH116, a glycoside hydrolase family 116 protein of 806 amino-acid residues sharing 37% amino-acid sequence identity over 783 residues with human glucosylceramidase 2 (GBA2), was expressed in Escherichia coli. Purification by heating, immobilized metal-affinity and size-exclusion chromatography produced >90% pure TxGH116 protein with an apparent molecular mass of 90 kDa on SDS-PAGE. The purified TxGH116 enzyme hydrolyzed the p-nitrophenyl (pNP) glycosides pNP-β-D-glucoside, pNP-β-D-galactoside and pNP-N-acetyl-β-D-glucopyranoside, as well as cellobiose and cellotriose. The TxGH116 protein was crystallized using a precipitant consisting of 0.6 M sodium citrate tribasic, 0.1 M Tris-HCl pH 7.0 by vapour diffusion with micro-seeding to form crystals with maximum dimensions of 120×25×5 µm. The TxGH116 crystals diffracted X-rays to 3.15 Å resolution and belonged to the monoclinic space group P2(1). Structure solution will allow a structural explanation of the effects of human GBA2 mutations. PMID:25615966

  19. Role of Key Salt Bridges in Thermostability of G. thermodenitrificans EstGtA2: Distinctive Patterns within the New Bacterial Lipolytic Enzyme Family XV

    PubMed Central

    Charbonneau, David M.; Beauregard, Marc

    2013-01-01

    Bacterial lipolytic enzymes were originally classified into eight different families defined by Arpigny and Jaeger (families I-VIII). Recently, the discovery of new lipolytic enzymes allowed for extending the original classification to fourteen families (I-XIV). We previously reported that G. thermodenitrificans EstGtA2 (access no. AEN92268) belonged to a novel group of bacterial lipolytic enzymes. Here we propose a 15th family (family XV) and suggest criteria for the assignation of protein sequences to the N’ subfamily. Five selected salt bridges, hallmarks of the N’ subfamily (E3/R54, E12/R37, E66/R140, D124/K178 and D205/R220) were disrupted in EstGtA2 using a combinatorial alanine-scanning approach. A set of 14 (R/K→A) mutants was produced, including five single, three double, three triple and three quadruple mutants. Despite a high tolerance to non-conservative mutations for folding, all the alanine substitutions were destabilizing (decreasing Tm by 5 to 14°C). A particular combination of four substitutions exceeded this tolerance and prevents the correct folding of EstGtA2, leading to enzyme inactivation. Although other mutants remain active at low temperatures, the accumulation of more than two mutations had a dramatic impact on EstGtA2 activity at high temperatures suggesting an important role of these conserved salt bridge-forming residues in thermostability of lipolytic enzymes from the N’ subfamily. We also identified a particular interloop salt bridge in EstGtA2 (D194/H222), located at position i -2 and i -4 residues from the catalytic Asp and His respectively which is conserved in other related bacterial lipolytic enzymes (families IV and XIII) with high tolerance to mutations and charge reversal. We investigated the role of residue identity at position 222 in controlling stability-pH dependence in EstGtA2. The introduction of a His to Arg mutation led to increase thermostability under alkaline pH. Our results suggest primary targets for optimization of EstGtA2 for specific biotechnological purposes. PMID:24116134

  20. Properties and Phylogeny of 76 Families of Bacterial and Eukaryotic Organellar Outer Membrane Pore-Forming Proteins.

    PubMed

    Reddy, Bhaskara L; Saier, Milton H

    2016-01-01

    We here report statistical analyses of 76 families of integral outer membrane pore-forming proteins (OMPPs) found in bacteria and eukaryotic organelles. 47 of these families fall into one superfamily (SFI) which segregate into fifteen phylogenetic clusters. Families with members of the same protein size, topology and substrate specificities often cluster together. Virtually all OMPP families include only proteins that form transmembrane pores. Nine such families, all of which cluster together in the SFI phylogenetic tree, contain both α- and β-structures, are multi domain, multi subunit systems, and transport macromolecules. Most other SFI OMPPs transport small molecules. SFII and SFV homologues derive from Actinobacteria while SFIII and SFIV proteins derive from chloroplasts. Three families of actinobacterial OMPPs and two families of eukaryotic OMPPs apparently consist primarily of α-helices (α-TMSs). Of the 71 families of (putative) β-barrel OMPPs, only twenty could not be assigned to a superfamily, and these derived primarily from Actinobacteria (1), chloroplasts (1), spirochaetes (8), and proteobacteria (10). Proteins were identified in which two or three full length OMPPs are fused together. Family characteristic are described and evidence agrees with a previous proposal suggesting that many arose by adjacent β-hairpin structural unit duplications. PMID:27064789

  1. Properties and Phylogeny of 76 Families of Bacterial and Eukaryotic Organellar Outer Membrane Pore-Forming Proteins

    PubMed Central

    Reddy, Bhaskara L.; Saier, Milton H.

    2016-01-01

    We here report statistical analyses of 76 families of integral outer membrane pore-forming proteins (OMPPs) found in bacteria and eukaryotic organelles. 47 of these families fall into one superfamily (SFI) which segregate into fifteen phylogenetic clusters. Families with members of the same protein size, topology and substrate specificities often cluster together. Virtually all OMPP families include only proteins that form transmembrane pores. Nine such families, all of which cluster together in the SFI phylogenetic tree, contain both α- and β-structures, are multi domain, multi subunit systems, and transport macromolecules. Most other SFI OMPPs transport small molecules. SFII and SFV homologues derive from Actinobacteria while SFIII and SFIV proteins derive from chloroplasts. Three families of actinobacterial OMPPs and two families of eukaryotic OMPPs apparently consist primarily of α-helices (α-TMSs). Of the 71 families of (putative) β-barrel OMPPs, only twenty could not be assigned to a superfamily, and these derived primarily from Actinobacteria (1), chloroplasts (1), spirochaetes (8), and proteobacteria (10). Proteins were identified in which two or three full length OMPPs are fused together. Family characteristic are described and evidence agrees with a previous proposal suggesting that many arose by adjacent β-hairpin structural unit duplications. PMID:27064789

  2. Evolution of a family of metazoan active-site-serine enzymes from penicillin-binding proteins: a novel facet of the bacterial legacy

    PubMed Central

    2008-01-01

    Background Bacterial penicillin-binding proteins and β-lactamases (PBP-βLs) constitute a large family of serine proteases that perform essential functions in the synthesis and maintenance of peptidoglycan. Intriguingly, genes encoding PBP-βL homologs occur in many metazoan genomes including humans. The emerging role of LACTB, a mammalian mitochondrial PBP-βL homolog, in metabolic signaling prompted us to investigate the evolutionary history of metazoan PBP-βL proteins. Results Metazoan PBP-βL homologs including LACTB share unique structural features with bacterial class B low molecular weight penicillin-binding proteins. The amino acid residues necessary for enzymatic activity in bacterial PBP-βL proteins, including the catalytic serine residue, are conserved in all metazoan homologs. Phylogenetic analysis indicated that metazoan PBP-βL homologs comprise four alloparalogus protein lineages that derive from α-proteobacteria. Conclusion While most components of the peptidoglycan synthesis machinery were dumped by early eukaryotes, a few PBP-βL proteins were conserved and are found in metazoans including humans. Metazoan PBP-βL homologs are active-site-serine enzymes that probably have distinct functions in the metabolic circuitry. We hypothesize that PBP-βL proteins in the early eukaryotic cell enabled the degradation of peptidoglycan from ingested bacteria, thereby maximizing the yield of nutrients and streamlining the cell for effective phagocytotic feeding. PMID:18226203

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

    PubMed

    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. PMID:24726830

  4. Architecture and Assembly of a Divergent Member of the ParM Family of Bacterial Actin-like Proteins

    PubMed Central

    Rivera, Christopher R.; Kollman, Justin M.; Polka, Jessica K.; Agard, David A.; Mullins, R. Dyche

    2011-01-01

    Eubacteria and archaea contain a variety of actin-like proteins (ALPs) that form filaments with surprisingly diverse architectures, assembly dynamics, and cellular functions. Although there is much data supporting differences between ALP families, there is little data regarding conservation of structure and function within these families. We asked whether the filament architecture and biochemical properties of the best-understood prokaryotic actin, ParM from plasmid R1, are conserved in a divergent member of the ParM family from plasmid pB171. Previous work demonstrated that R1 ParM assembles into filaments that are structurally distinct from actin and the other characterized ALPs. They also display three biophysical properties thought to be essential for DNA segregation: 1) rapid spontaneous nucleation, 2) symmetrical elongation, and 3) dynamic instability. We used microscopic and biophysical techniques to compare and contrast the architecture and assembly of these related proteins. Despite being only 41% identical, R1 and pB171 ParMs polymerize into nearly identical filaments with similar assembly dynamics. Conservation of the core assembly properties argues for their importance in ParM-mediated DNA segregation and suggests that divergent DNA-segregating ALPs with different assembly properties operate via different mechanisms. PMID:21339292

  5. Rapid induction by wounding and bacterial infection of an S gene family receptor-like kinase gene in Brassica oleracea.

    PubMed Central

    Pastuglia, M; Roby, D; Dumas, C; Cock, J M

    1997-01-01

    A receptor-like kinase, SRK, has been implicated in the autoincompatible response that leads to the rejection of self-pollen in Brassica plants. SRK is encoded by one member of a multigene family, which includes several receptor-like kinase genes with patterns of expression very different from that of SRK but of unknown function. Here, we report the characterization of a novel member of the Brassica S gene family, SFR2. RNA gel blot analysis demonstrated that SFR2 mRNA accumulated rapidly in response both to wounding and to infiltration with either of two bacteria: Xanthomonas campestris, a pathogen, and Escherichia coli, a saprophyte. SFR2 mRNA also accumulated rapidly after treatment with salicylic acid, a molecule that has been implicated in plant defense response signaling pathways. A SFR2 promoter and reporter gene fusion was introduced into tobacco and was shown to be induced by bacteria of another genus, Ralstonia (Pseudomonas) solanacearum. The accumulation of SFR2 mRNA in response to wounding and pathogen invasion is typical of a gene involved in the defense responses of the plant. The rapidity of SFR2 mRNA accumulation is consistent with SFR2 playing a role in the signal transduction pathway that leads to induction of plant defense proteins, such as pathogenesis-related proteins or enzymes of phenylpropanoid metabolism. PMID:9014364

  6. Advanced Microbial Taxonomy Combined with Genome-Based-Approaches Reveals that Vibrio astriarenae sp. nov., an Agarolytic Marine Bacterium, Forms a New Clade in Vibrionaceae

    PubMed Central

    Al-saari, Nurhidayu; Gao, Feng; A.K.M. Rohul, Amin; Sato, Kazumichi; Sato, Keisuke; Mino, Sayaka; Suda, Wataru; Oshima, Kenshiro; Hattori, Masahira; Ohkuma, Moriya; Meirelles, Pedro M.; Thompson, Fabiano L.; Thompson, Cristiane; A. Filho, Gilberto M.; Gomez-Gil, Bruno; Sawabe, Toko; Sawabe, Tomoo

    2015-01-01

    Advances in genomic microbial taxonomy have opened the way to create a more universal and transparent concept of species but is still in a transitional stage towards becoming a defining robust criteria for describing new microbial species with minimum features obtained using both genome and classical polyphasic taxonomies. Here we performed advanced microbial taxonomies combined with both genome-based and classical approaches for new agarolytic vibrio isolates to describe not only a novel Vibrio species but also a member of a new Vibrio clade. Two novel vibrio strains (Vibrio astriarenae sp. nov. C7T and C20) showing agarolytic, halophilic and fermentative metabolic activity were isolated from a seawater sample collected in a coral reef in Okinawa. Intraspecific similarities of the isolates were identical in both sequences on the 16S rRNA and pyrH genes, but the closest relatives on the molecular phylogenetic trees on the basis of 16S rRNA and pyrH gene sequences were V. hangzhouensis JCM 15146T (97.8% similarity) and V. agarivorans CECT 5085T (97.3% similarity), respectively. Further multilocus sequence analysis (MLSA) on the basis of 8 protein coding genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA, and topA) obtained by the genome sequences clearly showed the V. astriarenae strain C7T and C20 formed a distinct new clade protruded next to V. agarivorans CECT 5085T. The singleton V. agarivorans has never been included in previous MLSA of Vibrionaceae due to the lack of some gene sequences. Now the gene sequences are completed and analysis of 100 taxa in total provided a clear picture describing the association of V. agarivorans into pre-existing concatenated network tree and concluded its relationship to our vibrio strains. Experimental DNA-DNA hybridization (DDH) data showed that the strains C7T and C20 were conspecific but were separated from all of the other Vibrio species related on the basis of both 16S rRNA and pyrH gene phylogenies (e.g., V. agarivorans CECT 5085T, V. hangzhouensis JCM 15146T V. maritimus LMG 25439T, and V. variabilis LMG 25438T). In silico DDH data also supported the genomic relationship. The strains C7T also had less than 95% average amino acid identity (AAI) and average nucleotide identity (ANI) towards V. maritimus C210, V. variabilis C206, and V. mediterranei AK1T, V. brasiliensis LMG 20546T, V. orientalis ATCC 33934T, and V. sinaloensis DSM 21326. The name Vibrio astriarenae sp. nov. is proposed with C7 as the type strains. Both V. agarivorans CECT 5058T and V. astriarenae C7T are members of the newest clade of Vibrionaceae named Agarivorans. PMID:26313925

  7. Multiyear study of sludge application to farmland: prevalence of bacterial enteric pathogens and antibody status of farm families.

    PubMed Central

    Ottolenghi, A C; Hamparian, V V

    1987-01-01

    We describe our experience with the isolation of salmonellae from sewage sludge from four treatment plants in different geographic areas of Ohio. Over 3 years, we isolated salmonellae 50 times from 311 sludge samples. Most isolations were made after enrichment in Selenite broth (BBL Microbiology Systems, Cockeysville, Md.). The largest proportion of isolations came from the plant serving the population of Columbus, a large metropolitan area. A significantly greater number of isolations from this plant were made during the first quarter of the year. Twenty-one different serotypes were isolated, along with five untypable strains. The most frequently isolated serotype was Salmonella infantis. Five of the strains were multiply resistant to antibiotics. We also describe the prevalence of antibodies to salmonellae in members of the families residing on the farms in the study. It was found that antibodies to group C salmonellae predominated. PMID:3606093

  8. Diversity of Symbiotic Organs and Bacterial Endosymbionts of Lygaeoid Bugs of the Families Blissidae and Lygaeidae (Hemiptera: Heteroptera: Lygaeoidea)

    PubMed Central

    Renz, Patricia; Dettner, Konrad; Kehl, Siegfried

    2012-01-01

    Here we present comparative data on the localization and identity of intracellular symbionts among the superfamily Lygaeoidea (Insecta: Hemiptera: Heteroptera: Pentatomomorpha). Five different lygaeoid species from the families Blissidae and Lygaeidae (sensu stricto; including the subfamilies Lygaeinae and Orsillinae) were analyzed. Fluorescence in situ hybridization (FISH) revealed that all the bugs studied possess paired bacteriomes that are differently shaped in the abdomen and harbor specific endosymbionts therein. The endosymbionts were also detected in female gonads and at the anterior poles of developing eggs, indicating vertical transmission of the endosymbionts via ovarial passage, in contrast to the posthatch symbiont transmission commonly found among pentatomoid bugs (Pentatomomorpha: Pentatomoidea). Phylogenetic analysis based on 16S rRNA and groEL genes showed that the endosymbionts of Ischnodemus sabuleti, Arocatus longiceps, Belonochilus numenius, Orsillus depressus, and Ortholomus punctipennis constitute at least four distinct clades in the Gammaproteobacteria. The endosymbiont phylogeny did not agree with the host phylogeny based on the mitochondrial cytochrome oxidase I (COI) gene, but there was a local cospeciating pattern within the subfamily Orsillinae. Meanwhile, the endosymbiont of Belonochilus numenius (Lygaeidae: Orsillinae), although harbored in paired bacteriomes as in other lygaeoid bugs of the related genera Nysius, Ortholomus, and Orsillus, was phylogenetically close to “Candidatus Rohrkolberia cinguli,” the endosymbiont of Chilacis typhae (Lygaeoidea: Artheneidae), suggesting an endosymbiont replacement in this lineage. The diverse endosymbionts and the differently shaped bacteriomes may reflect independent evolutionary origins of the endosymbiotic systems among lygaeoid bugs. PMID:22307293

  9. Identification of a new steroid degrading bacterial strain H5 from the Baltic Sea and isolation of two estradiol inducible genes.

    PubMed

    Sang, Yingying; Xiong, Guangming; Maser, Edmund

    2012-03-01

    The presence of steroid hormones in the aquatic environment is potentially threatening the population dynamics of all kinds of sea animals and public health. Environmental estrogens in water have been reported to be associated with abnormal sexual development and abnormal feminizing responses in some animals. New approaches for the bioremediation of steroid hormones from the environment are therefore urgently sought. We have previously isolated a steroid degrading bacterial strain (H5) from the Baltic Sea, at Kiel, Germany. In the present investigation, 16S rRNA analysis showed that marine strain H5 belongs to the genus Vibrio, family Vibrionaceae and class Gamma-Proteobacteria. To enable identification of steroid inducible genes from bacterial strain H5, a library was constructed of H5 chromosomal DNA fragments cloned into a fluorescent reporter (pKEGFP-2). A reporter plasmid pK3α-4.6-EGFP3 containing the estrogen-inducible gene 3α-hydroxysteroid dehydrogenase/carbonyl reductase (3α-HSD/CR) from Comamonas testosteroni (C. testosteroni) was created as a positive control. Steroid induction could be detected by a microplate fluorescence reader, when the plasmids were transformed into Escherichia coli (E. coli) HB101 cells. With our meta-genomic pKEGFP-2 approach, we identified two estradiol-inducible genes from marine strain H5, which are obviously involved in steroid degradation. Sequencing of the pKEGFP-2 inserts and data base research at NCBI revealed that one gene corresponds to 3-ketosteroid-delta-1-dehydrogenase from several Mycobacterium strains, while the other showed high similarity to carboxylesterase in Sebadella termitidis and Brachyspira murdochii. Both 3-ketosteroid-delta-1-dehydrogenase and carboxylesterase are one of the first enzymes in steroid degradation. In addition, we identified a strain H5 specific DNA sequence of 480bp which allows sensitive PCR detection and quantification of strain H5 bacteria in "unknown" seawater samples. Currently, the exact characterization and systematic classification of the marine steroid degrading bacterial strain H5 is envisaged, which might be used for the bioremediation of steroid contaminations in seawater. Article from a special issue on steroids and microorganisms. PMID:21310233

  10. A Novel AtKEA Gene Family, Homolog of Bacterial K+/H+ Antiporters, Plays Potential Roles in K+ Homeostasis and Osmotic Adjustment in Arabidopsis

    PubMed Central

    Zheng, Sheng; Pan, Ting; Fan, Ligang; Qiu, Quan-Sheng

    2013-01-01

    AtKEAs, homologs of bacterial KefB/KefC, are predicted to encode K+/H+ antiporters in Arabidopsis. The AtKEA family contains six genes forming two subgroups in the cladogram: AtKEA1-3 and AtKEA4-6. AtKEA1 and AtKEA2 have a long N-terminal domain; the full-length AtKEA1 was inactive in yeast. The transport activity was analyzed by expressing the AtKEA genes in yeast mutants lacking multiple ion carriers. AtKEAs conferred resistance to high K+ and hygromycin B but not to salt and Li+ stress. AtKEAs expressed in both the shoot and root of Arabidopsis. The expression of AtKEA1, -3 and -4 was enhanced under low K+ stress, whereas AtKEA2 and AtKEA5 were induced by sorbitol and ABA treatments. However, osmotic induction of AtKEA2 and AtKEA5 was not observed in aba2-3 mutants, suggesting an ABA regulated mechanism for their osmotic response. AtKEAs’ expression may not be regulated by the SOS pathway since their expression was not affected in sos mutants. The GFP tagging analysis showed that AtKEAs distributed diversely in yeast. The Golgi localization of AtKEA3 was demonstrated by both the stably transformed seedlings and the transient expression in protoplasts. Overall, AtKEAs expressed and localized diversely, and may play roles in K+ homeostasis and osmotic adjustment in Arabidopsis. PMID:24278440

  11. Bacterial gastroenteritis

    MedlinePlus

    Infectious diarrhea - bacterial gastroenteritis; Acute gastroenteritis; Gastroenteritis - bacterial ... the sickness. All types of food poisoning cause diarrhea . Other symptoms include: Abdominal cramps Abdominal pain Bloody ...

  12. ABC transporters: bacterial exporters.

    PubMed Central

    Fath, M J; Kolter, R

    1993-01-01

    The ABC transporters (also called traffic ATPases) make up a large superfamily of proteins which share a common function and a common ATP-binding domain. ABC transporters are classified into three major groups: bacterial importers (the periplasmic permeases), eukaryotic transporters, and bacterial exporters. We present a comprehensive review of the bacterial ABC exporter group, which currently includes over 40 systems. The bacterial ABC exporter systems are functionally subdivided on the basis of the type of substrate that each translocates. We describe three main groups: protein exporters, peptide exporters, and systems that transport nonprotein substrates. Prototype exporters from each group are described in detail to illustrate our current understanding of this protein family. The prototype systems include the alpha-hemolysin, colicin V, and capsular polysaccharide exporters from Escherichia coli, the protease exporter from Erwinia chrysanthemi, and the glucan exporters from Agrobacterium tumefaciens and Rhizobium meliloti. Phylogenetic analysis of the ATP-binding domains from 29 bacterial ABC exporters indicates that the bacterial ABC exporters can be divided into two primary branches. One branch contains the transport systems where the ATP-binding domain and the membrane-spanning domain are present on the same polypeptide, and the other branch contains the systems where these domains are found on separate polypeptides. Differences in substrate specificity do not correlate with evolutionary relatedness. A complete survey of the known and putative bacterial ABC exporters is included at the end of the review. PMID:8302219

  13. Bacterial Sialidase

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Data shows that elevated sialidase in bacterial vaginosis patients correlates to premature births in women. Bacterial sialidase also plays a significant role in the unusual colonization of Pseudomonas aeruginosa in cystic fibrosis patients. Crystals of Salmonella sialidase have been reproduced and are used for studying the inhibitor-enzyme complexes. These inhibitors may also be used to inhibit a trans-sialidase of Trypanosome cruzi, a very similar enzyme to bacterial sialidase, therefore preventing T. cruzi infection, the causitive agent of Chagas' disease. The Center for Macromolecular Crystallography suggests that inhibitors of bacterial sialidases can be used as prophylactic drugs to prevent bacterial infections in these critical cases.

  14. Bacterial communities associated with Porites white patch syndrome (PWPS) on three western Indian Ocean (WIO) coral reefs.

    PubMed

    Séré, Mathieu G; Tortosa, Pablo; Chabanet, Pascale; Turquet, Jean; Quod, Jean-Pascal; Schleyer, Michael H

    2013-01-01

    The scleractinian coral Porites lutea, an important reef-building coral on western Indian Ocean reefs (WIO), is affected by a newly-reported white syndrome (WS) the Porites white patch syndrome (PWPS). Histopathology and culture-independent molecular techniques were used to characterise the microbial communities associated with this emerging disease. Microscopy showed extensive tissue fragmentation generally associated with ovoid basophilic bodies resembling bacterial aggregates. Results of 16S rRNA sequence analysis revealed a high variability between bacterial communities associated with PWPS-infected and healthy tissues in P. lutea, a pattern previously reported in other coral diseases such as black band disease (BBD), white band disease (WBD) and white plague diseases (WPD). Furthermore, substantial variations in bacterial communities were observed at the different sampling locations, suggesting that there is no strong bacterial association in Porites lutea on WIO reefs. Several sequences affiliated with potential pathogens belonging to the Vibrionaceae and Rhodobacteraceae were identified, mainly in PWPS-infected coral tissues. Among them, only two ribotypes affiliated to Shimia marina (NR043300.1) and Vibrio hepatarius (NR025575.1) were consistently found in diseased tissues from the three geographically distant sampling localities. The role of these bacterial species in PWPS needs to be tested experimentally. PMID:24391819

  15. Bacterial lipopolysaccharide increases tyrosine phosphorylation of zonula adherens proteins and opens the paracellular pathway in lung microvascular endothelia through TLR4, TRAF6, and src family kinase activation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: LPS is a key mediator in vascular leak syndromes associated with Gram-negative bacterial infections and opens the pulmonary vascular endothelial paracellular pathway through protein tyrosine kinase (PTK) activation. We asked which PTKs and signaling molecules mediate LPS-induced endothel...

  16. Bacterial Vaginosis

    MedlinePlus

    ... About NIAID News & Events Volunteer NIAID > Health & Research Topics > Bacterial Vaginosis Skip Website Tools Website Tools Print this page Order publications Volunteer for Clinical Studies Help people ...

  17. Bacterial Proteasomes

    PubMed Central

    Jastrab, Jordan B.; Darwin, K. Heran

    2015-01-01

    Interest in bacterial proteasomes was sparked by the discovery that proteasomal degradation is required for the pathogenesis of Mycobacterium tuberculosis, one of the world's deadliest pathogens. Although bacterial proteasomes are structurally similar to their eukaryotic and archaeal homologs, there are key differences in their mechanisms of assembly, activation, and substrate targeting for degradation. In this article, we compare and contrast bacterial proteasomes with their archaeal and eukaryotic counterparts, and we discuss recent advances in our understanding of how bacterial proteasomes function to influence microbial physiology. PMID:26488274

  18. Bacterial Vaginosis

    MedlinePlus

    ... incubation period for bacterial vaginosis. How Is the Diagnosis Made? Your childs pediatrician can make the diagnosis ... Editorial Policy This site complies with the HONcode standard for trustworthy health information: verify here. Copyright 2016 ...

  19. Bacterial communities associated with healthy and Acropora white syndrome-affected corals from American Samoa

    USGS Publications Warehouse

    Wilson, Bryan; Aeby, Greta S.; Work, Thierry M.; Bourne, David G.

    2012-01-01

    Acropora white syndrome (AWS) is characterized by rapid tissue loss revealing the white underlying skeleton and affects corals worldwide; however, reports of causal agents are conflicting. Samples were collected from healthy and diseased corals and seawater around American Samoa and bacteria associated with AWS characterized using both culture-dependent and culture-independent methods, from coral mucus and tissue slurries, respectively. Bacterial 16S rRNA gene clone libraries derived from coral tissue were dominated by the Gammaproteobacteria, and Jaccard's distances calculated between the clone libraries showed that those from diseased corals were more similar to each other than to those from healthy corals. 16S rRNA genes from 78 culturable coral mucus isolates also revealed a distinct partitioning of bacterial genera into healthy and diseased corals. Isolates identified as Vibrionaceae were further characterized by multilocus sequence typing, revealing that whilst several Vibrio spp. were found to be associated with AWS lesions, a recently described species, Vibrio owensii, was prevalent amongst cultured Vibrio isolates. Unaffected tissues from corals with AWS had a different microbiota than normal Acropora as found by others. Determining whether a microbial shift occurs prior to disease outbreaks will be a useful avenue of pursuit and could be helpful in detecting prodromal signs of coral disease prior to manifestation of lesions.

  20. Ichthyobacterium seriolicida gen. nov., sp. nov., a member of the phylum 'Bacteroidetes', isolated from yellowtail fish (Seriola quinqueradiata) affected by bacterial haemolytic jaundice, and proposal of a new family, Ichthyobacteriaceae fam. nov.

    PubMed

    Takano, Tomokazu; Matsuyama, Tomomasa; Sakai, Takamitsu; Nakamura, Yoji; Kamaishi, Takashi; Nakayasu, Chihaya; Kondo, Hidehiro; Hirono, Ikuo; Fukuda, Yutaka; Sorimachi, Minoru; Iida, Takaji

    2016-02-01

    A novel Gram-stain-negative, rod-shaped (0.3 × 4-6 μm), non-flagellated, aerobic strain with gliding motility, designated JBKA-6T, was isolated in 1991 from a yellowtail fish, Seriola quinqueradiata, showing symptoms of bacterial haemolytic jaundice. 16S rRNA gene sequence analysis showed that strain JBKA-6T was related most closely to members of the family Flavobacteriaceae in the phylum 'Bacteroidetes'. Furthermore, based on gyrB gene sequence analysis, JBKA-6T was classified into a single clade within the order Flavobacteriales, which was distinct from the known clades of the families Flavobacteriaceae, Blattabacteriaceae and Cryomorphaceae. The predominant isoprenoid quinone was identified as MK-6 (97.9 %), and the major cellular fatty acids (>10 %) were C14 : 0 and iso-C15 : 0. The main polar lipids were phosphatidylethanolamine, three unidentified phospholipids, two unidentified aminophospholipids and two unidentified polar lipids. The DNA G+C content of JBKA-6T, as derived from its whole genome, was 33.4 mol%. The distinct phylogenetic position and phenotypic traits of strain JBKA-6T distinguish it from all other described species of the phylum 'Bacteroidetes', and therefore it was concluded that strain JBKA-6T represents a new member of the phylum 'Bacteroidetes', and the name Ichthyobacterium seriolicida gen. nov., sp. nov. is proposed. The type strain of Ichthyobacterium seriolicida is JBKA-6T ( = ATCC BAA-2465T = JCM 18228T). We also propose that Icthyobacterium gen. nov. is the type genus of a novel family, Ichthyobacteriaceae fam. nov. PMID:26554606

  1. Bacterial rheotaxis.

    PubMed

    Marcos; Fu, Henry C; Powers, Thomas R; Stocker, Roman

    2012-03-27

    The motility of organisms is often directed in response to environmental stimuli. Rheotaxis is the directed movement resulting from fluid velocity gradients, long studied in fish, aquatic invertebrates, and spermatozoa. Using carefully controlled microfluidic flows, we show that rheotaxis also occurs in bacteria. Excellent quantitative agreement between experiments with Bacillus subtilis and a mathematical model reveals that bacterial rheotaxis is a purely physical phenomenon, in contrast to fish rheotaxis but in the same way as sperm rheotaxis. This previously unrecognized bacterial taxis results from a subtle interplay between velocity gradients and the helical shape of flagella, which together generate a torque that alters a bacterium's swimming direction. Because this torque is independent of the presence of a nearby surface, bacterial rheotaxis is not limited to the immediate neighborhood of liquid-solid interfaces, but also takes place in the bulk fluid. We predict that rheotaxis occurs in a wide range of bacterial habitats, from the natural environment to the human body, and can interfere with chemotaxis, suggesting that the fitness benefit conferred by bacterial motility may be sharply reduced in some hydrodynamic conditions. PMID:22411815

  2. Bacterial rheotaxis

    PubMed Central

    Marcos; Fu, Henry C.; Powers, Thomas R.; Stocker, Roman

    2012-01-01

    The motility of organisms is often directed in response to environmental stimuli. Rheotaxis is the directed movement resulting from fluid velocity gradients, long studied in fish, aquatic invertebrates, and spermatozoa. Using carefully controlled microfluidic flows, we show that rheotaxis also occurs in bacteria. Excellent quantitative agreement between experiments with Bacillus subtilis and a mathematical model reveals that bacterial rheotaxis is a purely physical phenomenon, in contrast to fish rheotaxis but in the same way as sperm rheotaxis. This previously unrecognized bacterial taxis results from a subtle interplay between velocity gradients and the helical shape of flagella, which together generate a torque that alters a bacterium's swimming direction. Because this torque is independent of the presence of a nearby surface, bacterial rheotaxis is not limited to the immediate neighborhood of liquid–solid interfaces, but also takes place in the bulk fluid. We predict that rheotaxis occurs in a wide range of bacterial habitats, from the natural environment to the human body, and can interfere with chemotaxis, suggesting that the fitness benefit conferred by bacterial motility may be sharply reduced in some hydrodynamic conditions. PMID:22411815

  3. A New Family of Membrane Electron Transporters and Its Substrates, Including a New Cell Envelope Peroxiredoxin, Reveal a Broadened Reductive Capacity of the Oxidative Bacterial Cell Envelope

    PubMed Central

    Cho, Seung-Hyun; Parsonage, Derek; Thurston, Casey; Dutton, Rachel J.; Poole, Leslie B.; Collet, Jean-Francois; Beckwith, Jon

    2012-01-01

    ABSTRACT The Escherichia coli membrane protein DsbD functions as an electron hub that dispatches electrons received from the cytoplasmic thioredoxin system to periplasmic oxidoreductases involved in protein disulfide isomerization, cytochrome c biogenesis, and sulfenic acid reduction. Here, we describe a new class of DsbD proteins, named ScsB, whose members are found in proteobacteria and Chlamydia. ScsB has a domain organization similar to that of DsbD, but its amino-terminal domain differs significantly. In DsbD, this domain directly interacts with substrates to reduce them, which suggests that ScsB acts on a different array of substrates. Using Caulobacter crescentus as a model organism, we searched for the substrates of ScsB. We discovered that ScsB provides electrons to the first peroxide reduction pathway identified in the bacterial cell envelope. The reduction pathway comprises a thioredoxin-like protein, TlpA, and a peroxiredoxin, PprX. We show that PprX is a thiol-dependent peroxidase that efficiently reduces both hydrogen peroxide and organic peroxides. Moreover, we identified two additional proteins that depend on ScsB for reduction, a peroxiredoxin-like protein, PrxL, and a novel protein disulfide isomerase, ScsC. Altogether, our results reveal that the array of proteins involved in reductive pathways in the oxidative cell envelope is significantly broader than was previously thought. Moreover, the identification of a new periplasmic peroxiredoxin indicates that in some bacteria, it is important to directly scavenge peroxides in the cell envelope even before they reach the cytoplasm. PMID:22493033

  4. Identification and expression analysis of 26 oncogenes of the receptor tyrosine kinase family in channel catfish after bacterial infection and hypoxic stress.

    PubMed

    Tian, Yi; Yao, Jun; Liu, Shikai; Jiang, Chen; Zhang, Jiaren; Li, Yun; Feng, Jianbin; Liu, Zhanjiang

    2015-06-01

    Receptor tyrosine kinases (RTKs) are high-affinity cell surface receptors for many polypeptide growth factors, cytokines and hormones. RTKs are not only key regulators of normal cellular processes, but are also involved in the progression of many types of tumors, and responses to various biotic and abiotic stresses. Catfish is a primary aquaculture species in the United States, while its industry is drastically hindered by several major diseases including enteric septicemia of catfish (ESC) that is caused by Edwardsiella ictaluri. Disease outbreaks are often accompanied by hypoxic stress, which affects the performance and survival of fish by reducing disease resistance. In this study, we identified 26 RTK oncogenes in the channel catfish genome, and determined their expression profiles after ESC infection and hypoxic stress. The 26 RTK genes were divided into four subfamilies according to phylogenetic analysis, including TIE (2 genes), ErbB (6 genes), EPH (14 genes), and INSR (4 genes). All identified RTKs possess a similar molecular architecture including ligand-binding domains, a single transmembrane helix and a cytoplasmic region, which suggests that these genes could play conserved biological roles. The expression analysis revealed that eight RTKs were significantly regulated after bacterial infection, with dramatic induction of insulin receptor genes including INSRb, IGF1Ra, and IGF1Rb. Upon hypoxic stress, EPHB3a, EGFR, ErbB4b, and IGF1Rb were expressed at higher levels in the tolerant catfish, while EPHA2a, EPHA2, TIE1 and INSRa were expressed at higher levels in the intolerant catfish. These results suggested the involvement of RTKs in immune responses and hypoxic tolerance. PMID:25722053

  5. B. subtilis ykuD Protein at 2.0 Angstrom Resolution: Insights into the Structure and Function of a Novel, Ubiquitous Family of Bacterial Enzymes

    SciTech Connect

    Bielnicki,J.; Devedjiev, Y.; Derewenda, U.; Dauter, Z.; Joachimiak, A.; Derewenda, Z.

    2006-01-01

    The crystal structure of the product of the Bacillus subtilis ykuD gene was solved by the multiwavelength anomalous dispersion (MAD) method and refined using data to 2.0 Angstroms resolution. The ykuD protein is a representative of a distinctly prokaryotic and ubiquitous family found among both pathogenic and nonpathogenic Gram-positive and Gram-negative bacteria. The deduced amino acid sequence reveals the presence of an N-terminal LysM domain, which occurs among enzymes involved in cell wall metabolism, and a novel, putative catalytic domain with a highly conserved His/Cys-containing motif of hitherto unknown structure. As the wild-type protein did not crystallize, a double mutant was designed (Lys117Ala/Gln118Ala) to reduce excess surface conformational entropy. As expected, the structure of the LysM domain is similar to the NMR structure reported for an analogous domain from Escherichia coli murein transglycosylase MltD. The molecular model also shows that the 112-residue-long C-terminal domain has a novel tertiary fold consisting of a {beta}-sandwich with two mixed sheets, one containing five strands and the other, six strands. The two {beta}-sheets form a cradle capped by an {alpha}-helix. This domain contains a putative catalytic site with a tetrad of invariant His123, Gly124, Cys139, and Arg141. The stereochemistry of this active site shows similarities to peptidotransferases and sortases, and suggests that the enzymes of the ykuD family may play an important role in cell wall biology.

  6. Eco-Evolutionary Dynamics of Episomes among Ecologically Cohesive Bacterial Populations

    DOE PAGESBeta

    Xue, Hong; Cordero, Otto X.; Camas, Francisco M.; Trimble, William; Meyer, Folker; Guglielmini, Julien; Rocha, Eduardo P. C.; Polz, Martin F.

    2015-05-05

    Although plasmids and other episomes are recognized as key players in horizontal gene transfer among microbes, their diversity and dynamics among ecologically structured host populations in the wild remain poorly understood. Here, we show that natural populations of marine Vibrionaceae bacteria host large numbers of families of episomes, consisting of plasmids and a surprisingly high fraction of plasmid-like temperate phages. Episomes are unevenly distributed among host populations, and contrary to the notion that high-density communities in biofilms act as hot spots of gene transfer, we identified a strong bias for episomes to occur in free-living as opposed to particle-attached cells.more » Mapping of episomal families onto host phylogeny shows that, with the exception of all phage and a few plasmid families, most are of recent evolutionary origin and appear to have spread rapidly by horizontal transfer. Such high eco-evolutionary turnover is particularly surprising for plasmids that are, based on previously suggested categorization, putatively nontransmissible, indicating that this type of plasmid is indeed frequently transferred by currently unknown mechanisms. Finally, analysis of recent gene transfer among plasmids reveals a network of extensive exchange connecting nearly all episomes. Genes functioning in plasmid transfer and maintenance are frequently exchanged, suggesting that plasmids can be rapidly transformed from one category to another. The broad distribution of episomes among distantly related hosts and the observed promiscuous recombination patterns show how episomes can offer their hosts rapid assembly and dissemination of novel functions.« less

  7. Eco-Evolutionary Dynamics of Episomes among Ecologically Cohesive Bacterial Populations

    SciTech Connect

    Xue, Hong; Cordero, Otto X.; Camas, Francisco M.; Trimble, William; Meyer, Folker; Guglielmini, Julien; Rocha, Eduardo P. C.; Polz, Martin F.

    2015-05-05

    Although plasmids and other episomes are recognized as key players in horizontal gene transfer among microbes, their diversity and dynamics among ecologically structured host populations in the wild remain poorly understood. Here, we show that natural populations of marine Vibrionaceae bacteria host large numbers of families of episomes, consisting of plasmids and a surprisingly high fraction of plasmid-like temperate phages. Episomes are unevenly distributed among host populations, and contrary to the notion that high-density communities in biofilms act as hot spots of gene transfer, we identified a strong bias for episomes to occur in free-living as opposed to particle-attached cells. Mapping of episomal families onto host phylogeny shows that, with the exception of all phage and a few plasmid families, most are of recent evolutionary origin and appear to have spread rapidly by horizontal transfer. Such high eco-evolutionary turnover is particularly surprising for plasmids that are, based on previously suggested categorization, putatively nontransmissible, indicating that this type of plasmid is indeed frequently transferred by currently unknown mechanisms. Finally, analysis of recent gene transfer among plasmids reveals a network of extensive exchange connecting nearly all episomes. Genes functioning in plasmid transfer and maintenance are frequently exchanged, suggesting that plasmids can be rapidly transformed from one category to another. The broad distribution of episomes among distantly related hosts and the observed promiscuous recombination patterns show how episomes can offer their hosts rapid assembly and dissemination of novel functions.

  8. Eco-Evolutionary Dynamics of Episomes among Ecologically Cohesive Bacterial Populations

    PubMed Central

    Xue, Hong; Cordero, Otto X.; Camas, Francisco M.; Trimble, William; Meyer, Folker; Guglielmini, Julien; Rocha, Eduardo P. C.

    2015-01-01

    ABSTRACT Although plasmids and other episomes are recognized as key players in horizontal gene transfer among microbes, their diversity and dynamics among ecologically structured host populations in the wild remain poorly understood. Here, we show that natural populations of marine Vibrionaceae bacteria host large numbers of families of episomes, consisting of plasmids and a surprisingly high fraction of plasmid-like temperate phages. Episomes are unevenly distributed among host populations, and contrary to the notion that high-density communities in biofilms act as hot spots of gene transfer, we identified a strong bias for episomes to occur in free-living as opposed to particle-attached cells. Mapping of episomal families onto host phylogeny shows that, with the exception of all phage and a few plasmid families, most are of recent evolutionary origin and appear to have spread rapidly by horizontal transfer. Such high eco-evolutionary turnover is particularly surprising for plasmids that are, based on previously suggested categorization, putatively nontransmissible, indicating that this type of plasmid is indeed frequently transferred by currently unknown mechanisms. Finally, analysis of recent gene transfer among plasmids reveals a network of extensive exchange connecting nearly all episomes. Genes functioning in plasmid transfer and maintenance are frequently exchanged, suggesting that plasmids can be rapidly transformed from one category to another. The broad distribution of episomes among distantly related hosts and the observed promiscuous recombination patterns show how episomes can offer their hosts rapid assembly and dissemination of novel functions. PMID:25944863

  9. Bacterial community shift is induced by dynamic environmental parameters in a changing coastal ecosystem (northern Adriatic, northeastern Mediterranean Sea)--a 2-year time-series study.

    PubMed

    Tinta, T; Vojvoda, J; Mozetič, P; Talaber, I; Vodopivec, M; Malfatti, F; Turk, V

    2015-10-01

    The potential link between the microbial dynamics and the environmental parameters was investigated in a semi-enclosed and highly dynamic coastal system (Gulf of Trieste, northern Adriatic Sea, NE Mediterranean Sea). Our comprehensive 2-year time-series study showed that despite the shallowness of this area, there was a significant difference between the surface and the bottom bacterial community structure. The bottom bacterial community was more diverse than the surface one and influenced by sediment re-suspension. The surface seawater temperature had a profound effect on bacterial productivity, while the bacterial community structure was more affected by freshwater-borne nutrients and phytoplankton blooms. Phytoplankton blooms caused an increase of Gammaproteobacteria (Alteromonadaceae, SAR86 and Vibrionaceae) and shift in dominance from SAR11 to Rhodobacteraceae taxon at the surface. Our results propose the importance of the water mass movements as drivers of freshwater-borne nutrients and of allochthonous microbial taxa. This study emphasizes the prediction power based on association networks analyses that are fed with long-term measurements of microbial and environmental parameters. These interaction maps offer valuable insights into the response of marine ecosystem to climate- and anthropogenic-driven stressors. PMID:24903068

  10. Bacterial Vaginosis

    MedlinePlus

    ... of getting an STD. BV may also affect women who have never had sex. You cannot get BV from toilet seats, bedding, or swimming pools. How can I avoid getting bacterial vaginosis? Doctors and scientists do not completely understand how BV is spread, ...

  11. Bacterial Immunity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A variety of bacterial agents reside in and around the environment that can cause illness and death in a poultry flock. Many cause disseminated disease while others exert more local effects such as the respiratory or gastrointestinal tract. The host, for our current purposes the laying hen, has de...

  12. Discovery of a Bacterial Glycoside Hydrolase Family 3 (GH3) β-Glucosidase with Myrosinase Activity from a Citrobacter Strain Isolated from Soil.

    PubMed

    Albaser, Abdulhadi; Kazana, Eleanna; Bennett, Mark H; Cebeci, Fatma; Luang-In, Vijitra; Spanu, Pietro D; Rossiter, John T

    2016-02-24

    A Citrobacter strain (WYE1) was isolated from a UK soil by enrichment using the glucosinolate sinigrin as sole carbon source. The enzyme myrosinase was purified using a combination of ion exchange and gel filtration to give a pure protein of approximately 66 kDa. The N-terminal amino acid and internal peptide sequence of the purified protein were determined and used to identify the gene, which, based on InterPro sequence analysis, belongs to the family GH3, contains a signal peptide, and is a periplasmic protein with a predicted molecular mass of 71.8 kDa. A preliminary characterization was carried out using protein extracts from cell-free preparations. The apparent KM and Vmax were 0.46 mM and 4.91 mmol dm(-3) min(-1) mg(-1), respectively, with sinigrin as substrate. The optimum temperature and pH for enzyme activity were 25 °C and 6.0, respectively. The enzyme was marginally activated with ascorbate by a factor of 1.67. PMID:26820976

  13. Bacterial Skin Infections.

    PubMed

    Ibrahim, Fadi; Khan, Tariq; Pujalte, George G A

    2015-12-01

    Skin and soft tissue infections account for 0.5% of outpatient visits to primary care. Skin and soft tissue infections can usually be managed in an outpatient setting. However, there are certain circumstances as discussed in this article that require more urgent care or inpatient management. Primary care providers should be able to diagnose, manage, and provide appropriate follow-up care for these frequently seen skin infections. This article provides family physicians with a comprehensive review of the assessment and management of common bacterial skin infections. PMID:26612370

  14. The PnrA (Tp0319; TmpC) lipoprotein represents a new family of bacterial purine nucleoside receptor encoded within an ATP-binding cassette (ABC)-like operon in Treponema pallidum.

    PubMed

    Deka, Ranjit K; Brautigam, Chad A; Yang, Xiaofeng F; Blevins, Jon S; Machius, Mischa; Tomchick, Diana R; Norgard, Michael V

    2006-03-24

    Treponema pallidum, the bacterial agent of syphilis, cannot be cultivated in vitro. This constraint has severely impeded the study of the membrane biology of this complex human pathogen. A structure-to-function approach thus was adopted as a means of discerning the likely function of Tp0319, a 35-kDa cytoplasmic membrane-associated lipoprotein of T. pallidum formerly designated as TmpC. A 1.7-A crystal structure showed that recombinant Tp0319 (rTp0319) consists of two alpha/beta domains, linked by three crossovers, with a deep cleft between them akin to ATP-binding cassette (ABC) receptors. In the cleft, a molecule of inosine was bound. Isothermal titration calorimetry demonstrated that rTp0319 specifically binds purine nucleosides (dissociation constant (Kd) approximately 10(-7) M). This predilection for purine nucleosides by rTp0319 is consistent with its likely role as a receptor component of a cytoplasmic membrane-associated transporter system. Reverse transcription-PCR analysis of RNA isolated from rabbit tissue-extracted T. pallidum additionally showed that tp0319 is transcriptionally linked to four other downstream open reading frames, thereby supporting the existence of an ABC-like operon (tp0319-0323). We herein thus re-name tp0319 as purine nucleoside receptor A (pnrA), with its operonic partners tp0320-0323 designated as pnrB-E, respectively. Our study not only infers that PnrA transports purine nucleosides essential for the survival of T. pallidum within its obligate human host, but to our knowledge, this is the first description of an ABC-type nucleoside transport system in any bacterium. PnrA has been grouped with a functionally uncharacterized protein family (HBG016869), thereby implying that other members of the family may have similar nucleoside-binding function(s). PMID:16418175

  15. Bacterial infections.

    PubMed

    Gray, F

    1997-01-01

    The organisms that produce bacterial infections of the nervous system in tropical regions are similar to those existing in the rest of the world. However, because of poor socio-economic conditions in the former areas, preventing the implementation of appropriate prophylactic and therapeutic measures, the incidence and course of these diseases may vary. In this paper the neuropathological appearances of the main bacterial diseases are reviewed and the main differences between those occurring in developed and developing countries emphasized. Despite great efforts by governments and communities, tuberculosis still remains a scourge in many countries and leprosy has not been eradicated from earth. Earlier optimism that antibiotics could finally put an end to syphilis have been dashed and the disease still persists. Moreover, the explosion of AIDS not only has produced a recrudescence of many of these diseases, but has also changed their clinical and pathological presentation. PMID:9034570

  16. Establishing a Role for Bacterial Cellulose in Environmental Interactions: Lessons Learned from Diverse Biofilm-Producing Proteobacteria

    PubMed Central

    Augimeri, Richard V.; Varley, Andrew J.; Strap, Janice L.

    2015-01-01

    Bacterial cellulose (BC) serves as a molecular glue to facilitate intra- and inter-domain interactions in nature. Biosynthesis of BC-containing biofilms occurs in a variety of Proteobacteria that inhabit diverse ecological niches. The enzymatic and regulatory systems responsible for the polymerization, exportation, and regulation of BC are equally as diverse. Though the magnitude and environmental consequences of BC production are species-specific, the common role of BC-containing biofilms is to establish close contact with a preferred host to facilitate efficient host–bacteria interactions. Universally, BC aids in attachment, adherence, and subsequent colonization of a substrate. Bi-directional interactions influence host physiology, bacterial physiology, and regulation of BC biosynthesis, primarily through modulation of intracellular bis-(3′→5′)-cyclic diguanylate (c-di-GMP) levels. Depending on the circumstance, BC producers exhibit a pathogenic or symbiotic relationship with plant, animal, or fungal hosts. Rhizobiaceae species colonize plant roots, Pseudomonadaceae inhabit the phyllosphere, Acetobacteriaceae associate with sugar-loving insects and inhabit the carposphere, Enterobacteriaceae use fresh produce as vehicles to infect animal hosts, and Vibrionaceae, particularly Aliivibrio fischeri, colonize the light organ of squid. This review will highlight the diversity of the biosynthesis and regulation of BC in nature by discussing various examples of Proteobacteria that use BC-containing biofilms to facilitate host–bacteria interactions. Through discussion of current data we will establish new directions for the elucidation of BC biosynthesis, its regulation and its ecophysiological roles. PMID:26635751

  17. Establishing a Role for Bacterial Cellulose in Environmental Interactions: Lessons Learned from Diverse Biofilm-Producing Proteobacteria.

    PubMed

    Augimeri, Richard V; Varley, Andrew J; Strap, Janice L

    2015-01-01

    Bacterial cellulose (BC) serves as a molecular glue to facilitate intra- and inter-domain interactions in nature. Biosynthesis of BC-containing biofilms occurs in a variety of Proteobacteria that inhabit diverse ecological niches. The enzymatic and regulatory systems responsible for the polymerization, exportation, and regulation of BC are equally as diverse. Though the magnitude and environmental consequences of BC production are species-specific, the common role of BC-containing biofilms is to establish close contact with a preferred host to facilitate efficient host-bacteria interactions. Universally, BC aids in attachment, adherence, and subsequent colonization of a substrate. Bi-directional interactions influence host physiology, bacterial physiology, and regulation of BC biosynthesis, primarily through modulation of intracellular bis-(3'→5')-cyclic diguanylate (c-di-GMP) levels. Depending on the circumstance, BC producers exhibit a pathogenic or symbiotic relationship with plant, animal, or fungal hosts. Rhizobiaceae species colonize plant roots, Pseudomonadaceae inhabit the phyllosphere, Acetobacteriaceae associate with sugar-loving insects and inhabit the carposphere, Enterobacteriaceae use fresh produce as vehicles to infect animal hosts, and Vibrionaceae, particularly Aliivibrio fischeri, colonize the light organ of squid. This review will highlight the diversity of the biosynthesis and regulation of BC in nature by discussing various examples of Proteobacteria that use BC-containing biofilms to facilitate host-bacteria interactions. Through discussion of current data we will establish new directions for the elucidation of BC biosynthesis, its regulation and its ecophysiological roles. PMID:26635751

  18. Bacterial Games

    NASA Astrophysics Data System (ADS)

    Frey, Erwin; Reichenbach, Tobias

    Microbial laboratory communities have become model systems for studying the complex interplay between nonlinear dynamics of evolutionary selection forces, stochastic fluctuations arising from the probabilistic nature of interactions, and spatial organization. Major research goals are to identify and understand mechanisms that ensure viability of microbial colonies by allowing for species diversity, cooperative behavior and other kinds of "social" behavior. A synthesis of evolutionary game theory, nonlinear dynamics, and the theory of stochastic processes provides the mathematical tools and conceptual framework for a deeper understanding of these ecological systems. We give an introduction to the modern formulation of these theories and illustrate their effectiveness, focusing on selected examples of microbial systems. Intrinsic fluctuations, stemming from the discreteness of individuals, are ubiquitous, and can have important impact on the stability of ecosystems. In the absence of speciation, extinction of species is unavoidable, may, however, take very long times. We provide a general concept for defining survival and extinction on ecological time scales. Spatial degrees of freedom come with a certain mobility of individuals. When the latter is sufficiently high, bacterial community structures can be understood through mapping individual-based models, in a continuum approach, onto stochastic partial differential equations. These allow progress using methods of nonlinear dynamics such as bifurcation analysis and invariant manifolds. We conclude with a perspective on the current challenges in quantifying bacterial pattern formation, and how this might have an impact on fundamental research in nonequilibrium physics .

  19. Vertebrate Acyl CoA synthetase family member 4 (ACSF4-U26) is a β-alanine-activating enzyme homologous to bacterial non-ribosomal peptide synthetase.

    PubMed

    Drozak, Jakub; Veiga-da-Cunha, Maria; Kadziolka, Beata; Van Schaftingen, Emile

    2014-03-01

    Mammalian ACSF4-U26 (Acyl CoA synthetase family member 4), a protein of unknown function, comprises a putative adenylation domain (AMP-binding domain) similar to those of bacterial non-ribosomal peptide synthetases, a putative phosphopantetheine attachment site, and a C-terminal PQQDH (pyrroloquinoline quinone dehydrogenase)-related domain. Orthologues comprising these three domains are present in many eukaryotes including plants. Remarkably, the adenylation domain of plant ACSF4-U26 show greater identity with Ebony, the insect enzyme that ligates β-alanine to several amines, than with vertebrate or insect ACSF4-U26, and prediction of its specificity suggests that it activates β-alanine. In the presence of ATP, purified mouse recombinant ACSF4-U26 progressively formed a covalent bond with radiolabelled β-alanine. The bond was not formed in a point mutant lacking the phosphopantetheine attachment site. Competition experiments with various amino acids indicated that the reaction was almost specific for β-alanine, and a KM of ~ 5 μm was calculated for this reaction. The loaded enzyme was used to study the formation of a potential end product. Among the 20 standard amino acids, only cysteine stimulated unloading of the enzyme. This effect was mimicked by cysteamine and dithiothreitol, and was unaffected by absence of the PQQDH-related domain, suggesting that β-alanine transfer onto thiols is catalysed by the ACSF4-U26 adenylation domain, but is physiologically irrelevant. We conclude that ACSF4-U26 is a β-alanine-activating enzyme, and hypothesize that it is involved in a rare intracellular reaction, possibly an infrequent post-translational or post-transcriptional modification. PMID:24467666

  20. Knock-out of SO1377 gene, which encodes the member of a conserved hypothetical bacterial protein family COG2268, results in alteration of iron metabolism, increased spontaneous mutation and hydrogen peroxide sensitivity in Shewanella oneidensis MR-1

    PubMed Central

    Gao, Weimin; Liu, Yongqing; Giometti, Carol S; Tollaksen, Sandra L; Khare, Tripti; Wu, Liyou; Klingeman, Dawn M; Fields, Matthew W; Zhou, Jizhong

    2006-01-01

    Background Shewanella oneidensis MR-1 is a facultative, gram-negative bacterium capable of coupling the oxidation of organic carbon to a wide range of electron acceptors such as oxygen, nitrate and metals, and has potential for bioremediation of heavy metal contaminated sites. The complete 5-Mb genome of S. oneidensis MR-1 was sequenced and standard sequence-comparison methods revealed approximately 42% of the MR-1 genome encodes proteins of unknown function. Defining the functions of hypothetical proteins is a great challenge and may need a systems approach. In this study, by using integrated approaches including whole genomic microarray and proteomics, we examined knockout effects of the gene encoding SO1377 (gi24372955), a member of the conserved, hypothetical, bacterial protein family COG2268 (Clusters of Orthologous Group) in bacterium Shewanella oneidensis MR-1, under various physiological conditions. Results Compared with the wild-type strain, growth assays showed that the deletion mutant had a decreased growth rate when cultured aerobically, but not affected under anaerobic conditions. Whole-genome expression (RNA and protein) profiles revealed numerous gene and protein expression changes relative to the wild-type control, including some involved in iron metabolism, oxidative damage protection and respiratory electron transfer, e. g. complex IV of the respiration chain. Although total intracellular iron levels remained unchanged, whole-cell electron paramagnetic resonance (EPR) demonstrated that the level of free iron in mutant cells was 3 times less than that of the wild-type strain. Siderophore excretion in the mutant also decreased in iron-depleted medium. The mutant was more sensitive to hydrogen peroxide and gave rise to 100 times more colonies resistant to gentamicin or kanamycin. Conclusion Our results showed that the knock-out of SO1377 gene had pleiotropic effects and suggested that SO1377 may play a role in iron homeostasis and oxidative damage protection in S. oneidensis MR-1. PMID:16600046

  1. Bacterial Hydrodynamics

    NASA Astrophysics Data System (ADS)

    Lauga, Eric

    2016-01-01

    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 micrometer 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, I review the biomechanics of bacterial motility and look ahead to future challenges.

  2. Bacterial symbionts and natural products

    PubMed Central

    Crawford, Jason M.; Clardy, Jon

    2011-01-01

    The study of bacterial symbionts of eukaryotic hosts has become a powerful discovery engine for chemistry. This highlight looks at four case studies that exemplify the range of chemistry and biology involved in these symbioses: a bacterial symbiont of a fungus and a marine invertebrate that produce compounds with significant anticancer activity, and bacterial symbionts of insects and nematodes that produce compounds that regulate multilateral symbioses. In the last ten years, a series of shocking revelations – the molecular equivalents of a reality TV show’s uncovering the true parents of a well known individual or a deeply hidden family secret – altered the study of genetically encoded small molecules, natural products for short. These revelations all involved natural products produced by bacterial symbionts, and while details differed, two main plot lines emerged: parentage, in which the real producers of well known natural products with medical potential were not the organisms from which they were originally discovered, and hidden relationships, in which bacterially produced small molecules turned out to be the unsuspected regulators of complex interactions. For chemists, these studies led to new molecules, new biosynthetic pathways, and an understanding of the biological functions these molecules fulfill. PMID:21594283

  3. Diverse Bacterial Microcompartment Organelles

    PubMed Central

    Chowdhury, Chiranjit; Sinha, Sharmistha; Chun, Sunny; Yeates, Todd O.

    2014-01-01

    SUMMARY Bacterial microcompartments (MCPs) are sophisticated protein-based organelles used to optimize metabolic pathways. They consist of metabolic enzymes encapsulated within a protein shell, which creates an ideal environment for catalysis and facilitates the channeling of toxic/volatile intermediates to downstream enzymes. The metabolic processes that require MCPs are diverse and widely distributed and play important roles in global carbon fixation and bacterial pathogenesis. The protein shells of MCPs are thought to selectively control the movement of enzyme cofactors, substrates, and products (including toxic or volatile intermediates) between the MCP interior and the cytoplasm of the cell using both passive electrostatic/steric and dynamic gated mechanisms. Evidence suggests that specialized shell proteins conduct electrons between the cytoplasm and the lumen of the MCP and/or help rebuild damaged iron-sulfur centers in the encapsulated enzymes. The MCP shell is elaborated through a family of small proteins whose structural core is known as a bacterial microcompartment (BMC) domain. BMC domain proteins oligomerize into flat, hexagonally shaped tiles, which assemble into extended protein sheets that form the facets of the shell. Shape complementarity along the edges allows different types of BMC domain proteins to form mixed sheets, while sequence variation provides functional diversification. Recent studies have also revealed targeting sequences that mediate protein encapsulation within MCPs, scaffolding proteins that organize lumen enzymes and the use of private cofactor pools (NAD/H and coenzyme A [HS-CoA]) to facilitate cofactor homeostasis. Although much remains to be learned, our growing understanding of MCPs is providing a basis for bioengineering of protein-based containers for the production of chemicals/pharmaceuticals and for use as molecular delivery vehicles. PMID:25184561

  4. Bacterial vaginosis.

    PubMed Central

    Spiegel, C A

    1991-01-01

    Bacterial vaginosis (BV) is the most common of the vaginitides affecting women of reproductive age. It appears to be due to an alteration in the vaginal ecology by which Lactobacillus spp., the predominant organisms in the healthy vagina, are replaced by a mixed flora including Prevotella bivia, Prevotella disiens, Porphyromonas spp., Mobiluncus spp., and Peptostreptococcus spp. All of these organisms except Mobiluncus spp. are also members of the endogenous vaginal flora. While evidence from treatment trials does not support the notion that BV is sexually transmitted, recent studies have shown an increased risk associated with multiple sexual partners. It has also been suggested that the pathogenesis of BV may be similar to that of urinary tract infections, with the rectum serving as a reservoir for some BV-associated flora. The organisms associated with BV have also been recognized as agents of female upper genital tract infection, including pelvic inflammatory disease, and the syndrome BV has been associated with adverse outcome of pregnancy, including premature rupture of membranes, chorioamnionitis, and fetal loss; postpartum endometritis; cuff cellulitis; and urinary tract infections. The mechanisms by which the BV-associated flora causes the signs of BV are not well understood, but a role for H2O2-producing Lactobacillus spp. in protecting against colonization by catalase-negative anaerobic bacteria has been recognized. These and other aspects of BV are reviewed. PMID:1747864

  5. Diversity, Structures, and Collagen-Degrading Mechanisms of Bacterial Collagenolytic Proteases

    PubMed Central

    Zhang, Yu-Zhong; Ran, Li-Yuan; Li, Chun-Yang

    2015-01-01

    Bacterial collagenolytic proteases are important because of their essential role in global collagen degradation and because of their virulence in some human bacterial infections. Bacterial collagenolytic proteases include some metalloproteases of the M9 family from Clostridium or Vibrio strains, some serine proteases distributed in the S1, S8, and S53 families, and members of the U32 family. In recent years, there has been remarkable progress in discovering new bacterial collagenolytic proteases and in investigating the collagen-degrading mechanisms of bacterial collagenolytic proteases. This review provides comprehensive insight into bacterial collagenolytic proteases, especially focusing on the structures and collagen-degrading mechanisms of representative bacterial collagenolytic proteases in each family. The roles of bacterial collagenolytic proteases in human diseases and global nitrogen cycling, together with the biotechnological and medical applications for these proteases, are also briefly discussed. PMID:26150451

  6. Bacterial concrete

    NASA Astrophysics Data System (ADS)

    Ramakrishnan, Venkataswamy; Ramesh, K. P.; Bang, S. S.

    2001-04-01

    Cracks in concrete are inevitable and are one of the inherent weaknesses of concrete. Water and other salts seep through these cracks, corrosion initiates, and thus reduces the life of concrete. So there was a need to develop an inherent biomaterial, a self-repairing material which can remediate the cracks and fissures in concrete. Bacterial concrete is a material, which can successfully remediate cracks in concrete. This technique is highly desirable because the mineral precipitation induced as a result of microbial activities is pollution free and natural. As the cell wall of bacteria is anionic, metal accumulation (calcite) on the surface of the wall is substantial, thus the entire cell becomes crystalline and they eventually plug the pores and cracks in concrete. This paper discusses the plugging of artificially cracked cement mortar using Bacillus Pasteurii and Sporosarcina bacteria combined with sand as a filling material in artificially made cuts in cement mortar which was cured in urea and CaCl2 medium. The effect on the compressive strength and stiffness of the cement mortar cubes due to the mixing of bacteria is also discussed in this paper. It was found that use of bacteria improves the stiffness and compressive strength of concrete. Scanning electron microscope (SEM) is used to document the role of bacteria in microbiologically induced mineral precipitation. Rod like impressions were found on the face of calcite crystals indicating the presence of bacteria in those places. Energy- dispersive X-ray (EDX) spectra of the microbial precipitation on the surface of the crack indicated the abundance of calcium and the precipitation was inferred to be calcite (CaCO3).

  7. Dehalococcoides mccartyi gen. nov., sp. nov., obligately organohalide-respiring anaerobic bacteria relevant to halogen cycling and bioremediation, belong to a novel bacterial class, Dehalococcoidia classis nov., order Dehalococcoidales ord. nov. and family Dehalococcoidaceae fam. nov., within the phylum Chloroflexi.

    PubMed

    Löffler, Frank E; Yan, Jun; Ritalahti, Kirsti M; Adrian, Lorenz; Edwards, Elizabeth A; Konstantinidis, Konstantinos T; Müller, Jochen A; Fullerton, Heather; Zinder, Stephen H; Spormann, Alfred M

    2013-02-01

    Six obligately anaerobic bacterial isolates (195(T), CBDB1, BAV1, VS, FL2 and GT) with strictly organohalide-respiring metabolisms were obtained from chlorinated solvent-contaminated aquifers, contaminated and uncontaminated river sediments or anoxic digester sludge. Cells were non-motile with a disc-shaped morphology, 0.3-1 µm in diameter and 0.1-0.2 µm thick, and characteristic indentations on opposite flat sides of the cell. Growth occurred in completely synthetic, reduced medium amended with a haloorganic electron acceptor (mostly chlorinated but also some brominated compounds), hydrogen as electron donor, acetate as carbon source, and vitamins. No other growth-supporting redox couples were identified. Aqueous hydrogen consumption threshold concentrations were <1 nM. Growth ceased when vitamin B(12) was omitted from the medium. Addition of sterile cell-free supernatant of Dehalococcoides-containing enrichment cultures enhanced dechlorination and growth of strains 195 and FL2, suggesting the existence of so-far unidentified stimulants. Dechlorination occurred between pH 6.5 and 8.0 and over a temperature range of 15-35 °C, with an optimum growth temperature between 25 and 30 °C. The major phospholipid fatty acids were 14 : 0 (15.7 mol%), br15 : 0 (6.2 mol%), 16 : 0 (22.7 mol%), 10-methyl 16 : 0 (25.8 mol%) and 18 : 0 (16.6 mol%). Unusual furan fatty acids including 9-(5-pentyl-2-furyl)-nonanoate and 8-(5-hexyl-2-furyl)-octanoate were detected in strains FL2, BAV1 and GT, but not in strains 195(T) and CBDB1. The 16S rRNA gene sequences of the six isolates shared more than 98 % identity, and phylogenetic analysis revealed an affiliation with the phylum Chloroflexi and more than 10 % sequence divergence from other described isolates. The genome sizes and G+C contents ranged from 1.34 to 1.47 Mbp and 47 to 48.9 mol% G+C, respectively. Based on 16S rRNA gene sequence comparisons, genome-wide average nucleotide identity and phenotypic characteristics, the organohalide-respiring isolates represent a new genus and species, for which the name Dehalococcoides mccartyi gen. nov., sp. nov. is proposed. Isolates BAV1 ( = ATCC BAA-2100  = JCM 16839  = KCTC 5957), FL2 ( = ATCC BAA-2098  = DSM 23585  = JCM 16840  = KCTC 5959), GT ( = ATCC BAA-2099  = JCM 16841  = KCTC 5958), CBDB1, 195(T) ( = ATCC BAA-2266(T)  = KCTC 15142(T)) and VS are considered strains of Dehalococcoides mccartyi, with strain 195(T) as the type strain. The new class Dehalococcoidia classis nov., order Dehalococcoidales ord. nov. and family Dehalococcoidaceae fam. nov. are described to accommodate the new taxon. PMID:22544797

  8. Genus Enhydrobacter Staley et al. 1987 should be recognized as a member of the family Rhodospirillaceae within the class Alphaproteobacteria.

    PubMed

    Kawamura, Yoshiaki; Fujiwara, Nagatoshi; Naka, Takashi; Mitani, Asako; Kubota, Hiromi; Tomida, Junko; Morita, Yuji; Hitomi, Jun

    2012-01-01

    The genus Enhydrobacter, first reported as a member of the family Vibrionaceae, has been placed in the family Moraxellaceae, but as a genus incertae sedis in Bergey's Manual of Systematic Bacteriology 2nd edition. During our taxonomic investigation of Enhydrobacter-like organisms, we observed that the 16S rRNA sequences of E. aerosaccus-type strain versions NCIMB 12535(T) , ATCC 27094( T) and CCUG 58314(T) were very different from the accessible data (accession no. AJ550856). Phylogenetic analysis of our 16S rRNA sequence data revealed that these organisms were located within the family Rhodospirillaceae. The genera Inquilinus, Oceanibaculum, Skermanella and Nisaea were closely related (sequence similarities were 88.3~87.0%), but Enhydrobacter could be distinguished from these genera by growth characteristics, fatty acid profiles (C(19:0) cyclo ω8c; 38.4% C(18:1) ω7c; 32.2%, and C(16:0) ; 8.9% were major components), in being non-flagellated, and differing in enzymatic activities, including trypsin and β-glucosidase. From these data, we conclude that the genus Enhydrobacter should be recognized as an independent genus of the family Rhodospirillaceae within the class Alphaproteobacteria. PMID:22145860

  9. Bacterial lipolytic enzymes: classification and properties.

    PubMed Central

    Arpigny, J L; Jaeger, K E

    1999-01-01

    Knowledge of bacterial lipolytic enzymes is increasing at a rapid and exciting rate. To obtain an overview of this industrially very important class of enzymes and their characteristics, we have collected and classified the information available from protein and nucleotide databases. Here we propose an updated and extensive classification of bacterial esterases and lipases based mainly on a comparison of their amino acid sequences and some fundamental biological properties. These new insights result in the identification of eight different families with the largest being further divided into six subfamilies. Moreover, the classification enables us to predict (1) important structural features such as residues forming the catalytic site or the presence of disulphide bonds, (2) types of secretion mechanism and requirement for lipase-specific foldases, and (3) the potential relationship to other enzyme families. This work will therefore contribute to a faster identification and to an easier characterization of novel bacterial lipolytic enzymes. PMID:10493927

  10. Covariation of viral parameters with bacterial assemblage richness and diversity in the water column and sediments

    NASA Astrophysics Data System (ADS)

    Hewson, Ian; Fuhrman, Jed A.

    2007-05-01

    Viruses are hypothesized to maintain diversity in microbial assemblages by regulating the abundance of dominant competitors and thereby allowing less-dominant competitors to persist in assemblages; however, there have been few empirical data sets to support this idea. In this study, we examined the relationship between the ratio of viral abundance to bacterial abundance, viral production, and the relative richness and diversity of bacterial assemblage fingerprints, in samples taken from geographically widespread locations (North Pacific gyre, the Amazon River plume and adjacent North Atlantic gyre, Gulf of Mexico, Southern California Bight and Arafura—Coral Seas) which are oligo- to mesotrophic. Bacterial assemblage richness and diversity as measured by automated rRNA intergenic spacer (ARISA) fingerprinting were significantly and positively correlated with the ratio of virus abundance to bacteria abundance (VBR) and to the rate of virus production only in the oligotrophic North Pacific gyre. ARISA fingerprint richness/diversity were not significantly correlated to viral parameters when assessed across all samples in surface waters, suggesting there is not a singular global quantitative relationship between viral pressure and host diversity within well evolved host/virus systems in different geographic locations in plankton. In sediments off Southern California, viral parameters significantly and negatively correlated with ARISA diversity, suggesting strong viral interactions in this habitat. To examine covariation of viral parameters and the relative abundance and diversity of rarer bacterial taxa (i.e., less-dominant competitor), the richness and diversity of diazotroph communities was measured using terminal restriction fragment length polymorphism (TRFLP) of a portion ( nifH) of the nitrogenase gene. The richness and diversity of diazotrophic communities were significantly and negatively correlated with viral parameters across all locations. Since diazotrophs include many opportunistic taxa (e.g. Vibrionaceae), and because these bacteria may be more susceptible to viral attack due to enhanced resource uptake abilities and potentially rapid localized growth, it is possible that this negative effect was due to enhanced viral lysis. Consequently, virus infection may have positive effects upon bacterioplankton diversity in the oligotrophic ocean, by regulating the abundance of dominant competitors, and allowing rarer taxa to coexist; however, some rarer taxa (such as diazotrophs) may be more susceptible to viral attack due to opportunistic lifestyles.

  11. The intrinsic resistome of bacterial pathogens

    PubMed Central

    Olivares, Jorge; Bernardini, Alejandra; Garcia-Leon, Guillermo; Corona, Fernando; B. Sanchez, Maria; Martinez, Jose L.

    2013-01-01

    Intrinsically resistant bacteria have emerged as a relevant health problem in the last years. Those bacterial species, several of them with an environmental origin, present naturally low-level susceptibility to several drugs. It has been proposed that intrinsic resistance is mainly the consequence of the impermeability of cellular envelopes, the activity of multidrug efflux pumps or the lack of appropriate targets for a given family of drugs. However, recently published articles indicate that the characteristic phenotype of susceptibility to antibiotics of a given bacterial species depends on the concerted activity of several elements, what has been named as intrinsic resistome. These determinants comprise not just classical resistance genes. Other elements, several of them involved in basic bacterial metabolic processes, are of relevance for the intrinsic resistance of bacterial pathogens. In the present review we analyze recent publications on the intrinsic resistomes of Escherichia coli and Pseudomonas aeruginosa. We present as well information on the role that global regulators of bacterial metabolism, as Crc from P. aeruginosa, may have on modulating bacterial susceptibility to antibiotics. Finally, we discuss the possibility of searching inhibitors of the intrinsic resistome in the aim of improving the activity of drugs currently in use for clinical practice. PMID:23641241

  12. Facial bacterial infections: folliculitis.

    PubMed

    Laureano, Ana Cristina; Schwartz, Robert A; Cohen, Philip J

    2014-01-01

    Facial bacterial infections are most commonly caused by infections of the hair follicles. Wherever pilosebaceous units are found folliculitis can occur, with the most frequent bacterial culprit being Staphylococcus aureus. We review different origins of facial folliculitis, distinguishing bacterial forms from other infectious and non-infectious mimickers. We distinguish folliculitis from pseudofolliculitis and perifolliculitis. Clinical features, etiology, pathology, and management options are also discussed. PMID:25441463

  13. Family History

    MedlinePlus

    Your family history includes health information about you and your close relatives. Families have many factors in common, including their genes, ... as heart disease, stroke, and cancer. Having a family member with a disease raises your risk, but ...

  14. Family Meals

    MedlinePlus

    ... Caring for Your Child All About Food Allergies Family Meals KidsHealth > For Parents > Family Meals Print A ... even more important as kids get older. Making Family Meals Happen It can be a big challenge ...

  15. Family Arguments

    MedlinePlus

    ... Spread the Word Shop AAP Find a Pediatrician Family Life Medical Home Family Dynamics Adoption & Foster Care ... Life Listen Español Text Size Email Print Share Family Arguments Page Content Article Body We seem to ...

  16. Demonstrating Bacterial Flagella.

    ERIC Educational Resources Information Center

    Porter, John R.; And Others

    1992-01-01

    Describes an effective laboratory method for demonstrating bacterial flagella that utilizes the Proteus mirabilis organism and a special harvesting technique. Includes safety considerations for the laboratory exercise. (MDH)

  17. Fungal and Bacterial Diseases.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fungal and bacterial diseases are important constraints to production. Recognition of diseases and information on their biology is important in disease management. This chapter is aimed at providing diagnostic information on fungal and bacterial diseases of sugar beet and their biology, epidemiolo...

  18. Family Privilege

    ERIC Educational Resources Information Center

    Seita, John R.

    2014-01-01

    Family privilege is defined as "strengths and supports gained through primary caring relationships." A generation ago, the typical family included two parents and a bevy of kids living under one roof. Now, every variation of blended caregiving qualifies as family. But over the long arc of human history, a real family was a

  19. Family Privilege

    ERIC Educational Resources Information Center

    Seita, John R.

    2014-01-01

    Family privilege is defined as "strengths and supports gained through primary caring relationships." A generation ago, the typical family included two parents and a bevy of kids living under one roof. Now, every variation of blended caregiving qualifies as family. But over the long arc of human history, a real family was a…

  20. Cancer, Families, and Family Counselors.

    ERIC Educational Resources Information Center

    Duffy, Maureen; Gillig, Scott

    2003-01-01

    Examines the role of the family counselor in working with cancer patients and their families. Suggests ways in which the family counselor can work proactively with families in the area of cancer prevention and helping them cope more effectively with its impact on their lives. Uses a clinical case example to illustrate intervention with cancer…

  1. Autoproteolytic Activation of Bacterial Toxins

    PubMed Central

    Shen, Aimee

    2010-01-01

    Protease domains within toxins typically act as the primary effector domain within target cells. By contrast, the primary function of the cysteine protease domain (CPD) in Multifunctional Autoprocessing RTX-like (MARTX) and Clostridium sp. glucosylating toxin families is to proteolytically cleave the toxin and release its cognate effector domains. The CPD becomes activated upon binding to the eukaryotic-specific small molecule, inositol hexakisphosphate (InsP6), which is found abundantly in the eukaryotic cytosol. This property allows the CPD to spatially and temporally regulate toxin activation, making it a prime candidate for developing anti-toxin therapeutics. In this review, we summarize recent findings related to defining the regulation of toxin function by the CPD and the development of inhibitors to prevent CPD-mediated activation of bacterial toxins. PMID:22069620

  2. Bacterial challenges in food

    PubMed Central

    Collee, J. G.

    1974-01-01

    Qualitative and quantitative aspects of bacterial challenges that might be encountered in food are discussed with reference to recognized and relatively unrecognized hazards. Mechanisms of pathogenicity are reviewed and the populations at risk are noted. The bacterial content of food as it is served at table merits more study. The challenge of prevention by education is discussed. Indirect bacterial challenges in our food are considered. The real challenge of diagnosis depends upon an awareness of a complex range of conditions; the importance of effective communication with efficient laboratory and epidemiological services is stressed. There is an increasing need for care in the preparation and distribution of food. PMID:4467860

  3. Family Violence and Family Physicians

    PubMed Central

    Herbert, Carol P.

    1991-01-01

    The acronym IDEALS summarizes family physicians' obligations when violence is suspected: to identify family violence; document injuries; educate families and ensure safety for victims; access resources and coordinate care; co-operate in the legal process; and provide support for families. Failure to respond reflects personal and professional experience and attitudes, fear of legal involvement, and lack of knowledge. Risks of intervention include physician burnout, physician overfunctioning, escalation of violence, and family disruption. PMID:21228987

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

    PubMed

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

    2015-10-01

    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. PMID:26506368

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

    PubMed Central

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

    2015-01-01

    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. PMID:26506368

  6. FAMILIAL SUICIDE

    PubMed Central

    Unni, K.E. Sadanaandan

    1996-01-01

    Seven completed suicides in a family of lower socioeconomic status and suburban domicile in Pondicherry are reported. The presence of bipolar affective disorder in the family members and the absence of exogenous factors are illustrated by utilising both family history method and family study method. The details collected formed the basis for the terminology ‘familial suicide’. The management of the index case, one of the only three surviving male members of the family, who presented with suicidal ruminations and depressive features, is described. PMID:21584122

  7. Bacterial surface adaptation

    NASA Astrophysics Data System (ADS)

    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.

  8. Bacterial Wound Culture

    MedlinePlus

    ... 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 ...

  9. Bacterial communities in the phylloplane of Prunus species.

    PubMed

    Jo, Yeonhwa; Cho, Jin Kyong; Choi, Hoseong; Chu, Hyosub; Lian, Sen; Cho, Won Kyong

    2015-04-01

    Bacterial populations in the phylloplane of four different Prunus species were investigated by 16 S rRNA pyrosequencing. Bioinformatic analysis identified an average of 510 operational taxonomic units belonging to 159 genera in 76 families. The two genera, Sphingomonas and Methylobacterium, were dominant in the phylloplane of four Prunus species. Twenty three genera were commonly identified in the four Prunus species, indicating a high level of bacterial diversity dependent on the plant species. Our study based on 16 S rRNA sequencing reveals the complexity of bacterial diversity in the phylloplane of Prunus species in detail. PMID:25515303

  10. Reconstruction of Bacterial and Viral Genomes from Multiple Metagenomes

    PubMed Central

    Gupta, Ankit; Kumar, Sanjiv; Prasoodanan, Vishnu P. K.; Harish, K.; Sharma, Ashok K.; Sharma, Vineet K.

    2016-01-01

    Several metagenomic projects have been accomplished or are in progress. However, in most cases, it is not feasible to generate complete genomic assemblies of species from the metagenomic sequencing of a complex environment. Only a few studies have reported the reconstruction of bacterial genomes from complex metagenomes. In this work, Binning-Assembly approach has been proposed and demonstrated for the reconstruction of bacterial and viral genomes from 72 human gut metagenomic datasets. A total 1156 bacterial genomes belonging to 219 bacterial families and, 279 viral genomes belonging to 84 viral families could be identified. More than 80% complete draft genome sequences could be reconstructed for a total of 126 bacterial and 11 viral genomes. Selected draft assembled genomes could be validated with 99.8% accuracy using their ORFs. The study provides useful information on the assembly expected for a species given its number of reads and abundance. This approach along with spiking was also demonstrated to be useful in improving the draft assembly of a bacterial genome. The Binning-Assembly approach can be successfully used to reconstruct bacterial and viral genomes from multiple metagenomic datasets obtained from similar environments. PMID:27148174

  11. Rural Families.

    ERIC Educational Resources Information Center

    Goetz, Kathy, Ed.

    1992-01-01

    This "special focus" journal issue consists of 13 individual articles on the theme of rural family programs relating to school, health services, church, and other institutions. It includes: (1) "Towards a Rural Family Policy" (Judith K. Chynoweth and Michael D. Campbell); (2) "Montana: Council for Families Collaborates for Prevention (Jean…

  12. Family therapy.

    PubMed

    Altamash, Shaikh

    2013-10-01

    Another major force not letting us succeed in the treatment of diabetes remains right inside the patients home, their family members. Hence, it is important to know the perception of the close family members about this simple and strong tool in diabetes, 'insulin'. The drug is nearing its century, it has not fully being accepted gracefully even in todays electronic savvy society. So, we need to strongly discover the reason for its non-acceptance, while trials are out inventing new drugs. One vital thing that can change this attitude is increasing the understanding of this drug, insulin in depth to close people around the patient, the 'family'. Underestimating family's perception about disease and treatment for diabetes is detrimental to both diseased and the doctor. This consists of a biopsychosocial model; biological, psychological and social factors. Family forms the most important part of it. The strategies in family therapy include psychodynamic, structural, strategic, and cognitive-behavioral component. Diabetes has and will continue to rise, so will be the treatment options. From the clinicians side its to fix fasting first but from patients its fix family first. Family therapy demonstrates the importance of insulin initiation and maintenance in insulin naive patients, and continuation for others. The specific needs of such patients and their impact on family life are met with family therapy. Who needs family therapy? Benefits of family therapy and a case based approach is covered. PMID:24251191

  13. Family Involvement.

    ERIC Educational Resources Information Center

    Liontos, Lynn Balster

    1992-01-01

    Family involvement in schools will work only when perceived as an enlarged concept focusing on all children, including those from at-risk families. Each publication reviewed here is specifically concerned with family involvement strategies concerned with all children or targeted at primarily high risk students. Susan McAllister Swap looks at three…

  14. Family Support.

    ERIC Educational Resources Information Center

    Wieck, Colleen, Ed.; McBride, Marijo, Ed.

    1990-01-01

    This "Feature Issue" of the quarterly journal "Impact" presents 19 brief articles on family support systems in the United States for persons with developmental disabilities and their families. Emphasis is on provisions of Public Law 99-457. Articles include: "Family Support in the United States: Setting a Course for the 1990s" (James Knoll);…

  15. Tracking bacterial growth in liquid media and a new bacterial life model.

    PubMed

    Liu, S

    1999-12-01

    By increasing viscosity of liquid media above 8.4 centipoise (cp) i.e. 0.084 g * cm(-1) * s(-1), individual growth and family formation of Escherichia coli was continuously observed in real-time for up to 6 h. The observations showed primarily unidirectional growth and reproduction of E. coli and suggested more than one reproduction in the observed portion of E. coli life span. A new bacterial life model is proposed: each bacterium has a stable cell polarity that ultimately transforms into two bacteria of different generations; the life cycle of a bacterium can contain more than one reproduction cycle; and the age of a bacterium should be defined by its experienced chronological time. This new bacterial life model differs from the dominant concepts of bacterial life but complies with all basic life principles based on direct observation of macroorganisms. PMID:18726488

  16. Bacterial extracellular zinc-containing metalloproteases.

    PubMed Central

    Häse, C C; Finkelstein, R A

    1993-01-01

    Extracellular zinc-containing metalloproteases are widely distributed in the bacterial world. The most extensively studied are those which are associated with pathogenic bacteria or bacteria which have industrial significance. They are found practically wherever they are sought in both gram-negative and gram-positive microorganisms, be they aerobic or anaerobic. This ubiquity in itself implies that these enzymes serve important functions for the organisms which produce them. Because of the importance of zinc to enzymatic activity, it is not surprising that there is a pervasive amino acid sequence homology in the primary structure of this family of enzymes regardless of their source. The evidence suggests that both convergent and divergent evolutionary forces are at work. Within the large family of bacterial zinc-containing metalloendopeptidases, smaller family units are observed, such as thermolysin-like, elastase-like, and Serratia protease-like metalloproteases from various bacterial species. While this review was in the process of construction, a new function for zinc-containing metalloproteases was discovered: the neurotoxins of Clostridium tetani and Clostridium botulinum type B have been shown to be zinc metalloproteases with specificity for synaptobrevin, an integral membrane protein of small synaptic vesicles which is involved in neurotransmission. Additional understanding of the mode of action of proteases which contribute to pathogenicity could lead to the development of inhibitors, such as chelators, surrogate substrates, or antibodies, which could prevent or interrupt the disease process. Further studies of this broad family of metalloproteases will provide important additional insights into the pathogenesis and structure-function relationships of enzymes and will lead to the development of products, including "designer proteins," which might be industrially and/or therapeutically useful. PMID:8302217

  17. HbpR, a New Member of the XylR/DmpR Subclass within the NtrC Family of Bacterial Transcriptional Activators, Regulates Expression of 2-Hydroxybiphenyl Metabolism in Pseudomonas azelaica HBP1

    PubMed Central

    Jaspers, Marco C. M.; Suske, Winfried A.; Schmid, Andreas; Goslings, David A. M.; Kohler, Hans-Peter E.; van der Meer, Jan Roelof

    2000-01-01

    The regulation of 2-hydroxybiphenyl and 2,2′-dihydroxybiphenyl degradation in Pseudomonas azelaica is mediated by the regulatory gene, hbpR. The hbpR gene encodes a 63-kDa protein belonging to the NtrC family of prokaryotic transcriptional activators and having the highest homology to members of the XylR/DmpR subclass. Disruption of the hbpR gene in P. azelaica and complementation in trans showed that the HbpR protein was the key regulator for 2-hydroxybiphenyl metabolism. Induction experiments with P. azelaica and Escherichia coli containing luxAB-based transcriptional fusions revealed that HbpR activates transcription from a promoter (PhbpC) in front of the first gene for 2-hydroxybiphenyl degradation, hbpC, and that 2-hydroxybiphenyl itself is the direct effector for HbpR-mediated activation. Of several compounds tested, only the pathway substrates 2-hydroxybiphenyl and 2,2′-dihydroxybiphenyl and structural analogs like 2-aminobiphenyl and 2-hydroxybiphenylmethane were effectors for HbpR activation. HbpR is therefore, to our knowledge, the first regulator of the XylR/DmpR class that recognizes biaromatic but not monoaromatic structures. Analysis of a spontaneously occurring mutant, P. azelaica HBP1 Prp, which can grow with the non-wild-type effector 2-propylphenol, revealed a single mutation in the hbpR gene (T613C) leading to a Trp→Arg substitution at amino acid residue 205. P. azelaica HBP1 derivative strains without a functional hbpR gene constitutively expressed the genes for 2-hydroxybiphenyl degradation when complemented in trans with the hbpR-T613C gene. This suggests the importance of this residue, which is conserved among all members of the XylR/DmpR subclass, for interdomain repression. PMID:10629187

  18. Echocardiography in bacterial endocarditis.

    PubMed

    Wann, L S; Dillon, J C; Weyman, A E; Feigenbaum, H

    1976-07-15

    We examined 129 standard M-mode echocardiograms obtained in 65 patients (16 to 73 years old) with bacterial endocarditis. Twenty of the 22 patients with vegetations recognizable by echocargiography died, or underwent cardiac operation (mean interval from admission 22 days, and range two to 120 days). Vegetations were seen on the echocardiograms in 22 (aortic 10, mitral nine and tricuspid three, with anatomic confirmation in 19). Of patients without vegetations on echocardiography none underwent emergency operation or died as a result of cardiac disease (mean follow-up period of 14 months, range of two to 38 months). Other echocardiographic findings in those with vegetations included early mitral-valve closure (six), "flail" aortic leaflet (three), and "flail" mitral leaflet (three). Echocardiography can provide a rapid, reliable noninvasive diagnosis of bacterial vegetations in certain patients with bacterial endocarditis and may identify patients with more severe disease who may require operative intervention. PMID:1272330

  19. Lipoproteins of bacterial pathogens.

    PubMed

    Kovacs-Simon, A; Titball, R W; Michell, S L

    2011-02-01

    Bacterial lipoproteins are a set of membrane proteins with many different functions. Due to this broad-ranging functionality, these proteins have a considerable significance in many phenomena, from cellular physiology through cell division and virulence. Here we give a general overview of lipoprotein biogenesis and highlight examples of the roles of lipoproteins in bacterial disease caused by a selection of medically relevant Gram-negative and Gram-positive pathogens: Mycobacterium tuberculosis, Streptococcus pneumoniae, Borrelia burgdorferi, and Neisseria meningitidis. Lipoproteins have been shown to play key roles in adhesion to host cells, modulation of inflammatory processes, and translocation of virulence factors into host cells. As such, a number of lipoproteins have been shown to be potential vaccines. This review provides a summary of some of the reported roles of lipoproteins and of how this knowledge has been exploited in some cases for the generation of novel countermeasures to bacterial diseases. PMID:20974828

  20. CAMBer: an approach to support comparative analysis of multiple bacterial strains

    PubMed Central

    2011-01-01

    Background There is a large amount of inconsistency in gene structure annotations of bacterial strains. This inconsistency is a frustrating impedance to effective comparative genomic analysis of bacterial strains in promising applications such as gaining insights into bacterial drug resistance. Results Here, we propose CAMBer as an approach to support comparative analysis of multiple bacterial strains. CAMBer produces what we called multigene families. Each multigene family reveals genes that are in one-to-one correspondence in the bacterial strains, thereby permitting their annotations to be integrated. We present results of our method applied to three human pathogens: Escherichia coli, Mycobacterium tuberculosis and Staphylococcus aureus. Conclusions As a result, more accurate and more comprehensive annotations of the bacterial strains can be produced. PMID:21989220

  1. Bacterial vaginosis in pregnancy.

    PubMed

    McGregor, J A; French, J I

    2000-05-01

    Bacterial vaginosis is a clinical condition caused by replacement of the normal hydrogen peroxide producing Lactobacillus sp. in the vagina with high concentrations of characteristic sets of aerobic and anaerobic bacteria. Bacterial vaginosis is the most prevalent cause of vaginal discharge or malodor, although 50 percent of women who meet the criteria for this condition are asymptomatic. Bacterial vaginosis is reported in 10 to 41 percent of women, and new evidence has shown association with maternal and fetal morbidity. Studies have shown that spontaneous abortion, preterm labor, premature birth, preterm premature rupture of the membranes, amniotic fluid infection, postpartum endometritis, and postcesarean wound infections are increased because of infection with bacterial vaginosis during pregnancy. Clinical trials demonstrated important reductions in many of these adverse events with appropriate screening and antimicrobial treatment protocols. New low-cost, diagnostic, point-of-care screening tools are available for rapid screening of patients, affording the physician the opportunity to potentially make a dramatic clinical and cost impact in preventing preterm birth and the costly sequelae of prematurity. Practicing physicians need to be aware of current guidelines for screening and treating pregnant patients for bacterial vaginosis. The authors recommend that all pregnant women be screened and treated with the Centers for Disease Control and Prevention (CDC-P) recommended oral regimens early in pregnancy. Each treated women should be evaluated for "test of cure" 1 month after treatment. Mothers likely to benefit from "screen and treat" approaches include 1) those with the highest concentrations of genital anaerobes and mycoplasmas, 2) women with prior preterm birth or who have low body mass (BMI < 19.8 kg/m2), 3) those with evidence of endometritis before pregnancy, and 4) those who are treated with oral agents effective for both presumed intrauterine mycoplasmas and other bacterial vaginosis flora (i.e., oral clindamycin or erythromycin and metronidazole). PMID:10804540

  2. [Diagnosis of bacterial vaginosis].

    PubMed

    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. PMID:24073569

  3. Crystal Structures of Two Bacterial 3-Hydroxy-3-methylglutaryl-CoA Lyases Suggest a Common Catalytic Mechanism among a Family of TIM Barrel Metalloenzymes Cleaving Carbon-Carbon Bonds

    SciTech Connect

    Forouhar,F.; Hussain, M.; Farid, R.; Benach, J.; Abashidze, M.; Edstrom, W.; Vorobiev, S.; Montelione, G.; Hunt, J.; et al.

    2006-01-01

    The enzyme 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) lyase catalyzes the terminal steps in ketone body generation and leucine degradation. Mutations in this enzyme cause a human autosomal recessive disorder called primary metabolic aciduria, which typically kills victims because of an inability to tolerate hypoglycemia. Here we present crystal structures of the HMG-CoA lyases from Bacillus subtilis and Brucella melitensis at 2.7 and 2.3 {angstrom} resolution, respectively. These enzymes share greater than 45% sequence identity with the human orthologue. Although the enzyme has the anticipated triose-phosphate isomerase (TIM) barrel fold, the catalytic center contains a divalent cation-binding site formed by a cluster of invariant residues that cap the core of the barrel, contrary to the predictions of homology models. Surprisingly, the residues forming this cation-binding site and most of their interaction partners are shared with three other TIM barrel enzymes that catalyze diverse carbon-carbon bond cleavage reactions believed to proceed through enolate intermediates (4-hydroxy-2-ketovalerate aldolase, 2-isopropylmalate synthase, and transcarboxylase 5S). We propose the name 'DRE-TIM metallolyases' for this newly identified enzyme family likely to employ a common catalytic reaction mechanism involving an invariant Asp-Arg-Glu (DRE) triplet. The Asp ligates the divalent cation, while the Arg probably stabilizes charge accumulation in the enolate intermediate, and the Glu maintains the precise structural alignment of the Asp and Arg. We propose a detailed model for the catalytic reaction mechanism of HMG-CoA lyase based on the examination of previously reported product complexes of other DRE-TIM metallolyases and induced fit substrate docking studies conducted using the crystal structure of human HMG-CoA lyase (reported in the accompanying paper by Fu, et al. (2006) J. Biol. Chem. 281, 7526-7532). Our model is consistent with extensive mutagenesis results and can guide subsequent studies directed at definitive experimental elucidation of this enzyme's reaction mechanism.

  4. Calibrating bacterial evolution

    PubMed Central

    Ochman, Howard; Elwyn, Susannah; Moran, Nancy A.

    1999-01-01

    Attempts to calibrate bacterial evolution have relied on the assumption that rates of molecular sequence divergence in bacteria are similar to those of higher eukaryotes, or to those of the few bacterial taxa for which ancestors can be reliably dated from ecological or geological evidence. Despite similarities in the substitution rates estimated for some lineages, comparisons of the relative rates of evolution at different classes of nucleotide sites indicate no basis for their universal application to all bacteria. However, there is evidence that bacteria have a constant genome-wide mutation rate on an evolutionary time scale but that this rate differs dramatically from the rate estimated by experimental methods. PMID:10535975

  5. Bacterial transfer RNAs

    PubMed Central

    Shepherd, Jennifer; Ibba, Michael

    2015-01-01

    Transfer RNA is an essential adapter molecule that is found across all three domains of life. The primary role of transfer RNA resides in its critical involvement in the accurate translation of messenger RNA codons during protein synthesis and, therefore, ultimately in the determination of cellular gene expression. This review aims to bring together the results of intensive investigations into the synthesis, maturation, modification, aminoacylation, editing and recycling of bacterial transfer RNAs. Codon recognition at the ribosome as well as the ever-increasing number of alternative roles for transfer RNA outside of translation will be discussed in the specific context of bacterial cells. PMID:25796611

  6. Widespread presence of "bacterial-like" PPP phosphatases in eukaryotes

    PubMed Central

    Andreeva, Alexandra V; Kutuzov, Mikhail A

    2004-01-01

    Background In eukaryotes, PPP (protein phosphatase P) family is one of the two known protein phosphatase families specific for Ser and Thr. The role of PPP phosphatases in multiple signaling pathways in eukaryotic cell has been extensively studied. Unlike eukaryotic PPP phosphatases, bacterial members of the family have broad substrate specificity or may even be Tyr-specific. Moreover, one group of bacterial PPPs are diadenosine tetraphosphatases, indicating that bacterial PPP phosphatases may not necessarily function as protein phosphatases. Results We describe the presence in eukaryotes of three groups of expressed genes encoding "non-conventional" phosphatases of the PPP family. These enzymes are more closely related to bacterial PPP phosphatases than to the known eukaryotic members of the family. One group, found exclusively in land plants, is most closely related to PPP phosphatases from some α-Proteobacteria, including Rhizobiales, Rhodobacterales and Rhodospirillaceae. This group is therefore termed Rhizobiales / Rhodobacterales / Rhodospirillaceae-like phosphatases, or Rhilphs. Phosphatases of the other group are found in Viridiplantae, Rhodophyta, Trypanosomatidae, Plasmodium and some fungi. They are structurally related to phosphatases from psychrophilic bacteria Shewanella and Colwellia, and are termed Shewanella-like phosphatases, or Shelphs. Phosphatases of the third group are distantly related to ApaH, bacterial diadenosine tetraphosphatases, and are termed ApaH-like phosphatases, or Alphs. Patchy distribution of Alphs in animals, plants, fungi, diatoms and kinetoplasts suggests that these phosphatases were present in the common ancestor of eukaryotes but were independently lost in many lineages. Rhilphs, Shelphs and Alphs form PPP clades, as divergent from "conventional" eukaryotic PPP phosphatases as they are from each other and from major bacterial clades. In addition, comparison of primary structures revealed a previously unrecognised (I/L/V)D(S/T)G motif, conserved in all bacterial and "bacterial-like" eukaryotic PPPs, but not in "conventional" eukaryotic and archaeal PPPs. Conclusions Our findings demonstrate that many eukaryotes possess diverse "bacterial-like" PPP phosphatases, the enzymatic characteristics, physiological roles and precise evolutionary history of which have yet to be determined. PMID:15555063

  7. The Bacterial Growth Curve.

    ERIC Educational Resources Information Center

    Paulton, Richard J. L.

    1991-01-01

    A procedure that allows students to view an entire bacterial growth curve during a two- to three-hour student laboratory period is described. Observations of the lag phase, logarithmic phase, maximum stationary phase, and phase of decline are possible. A nonpathogenic, marine bacterium is used in the investigation. (KR)

  8. Immunopotentiation for bacterial biodefense.

    PubMed

    Skyberg, Jerod A

    2014-01-01

    Activation of the innate immune system can enhance resistance to a variety of bacterial and viral infections. In situations where the etiological agent of disease is unknown, such as a bioterror attack, stimulation of innate immunity may be particularly useful as induced immune responses are often capable of providing protection against a broad range of pathogens. In particular, the threat of an intentional release of a highly virulent bacterial pathogen that is either intrinsically resistant to antibiotics, or has been weaponized via the introduction of antibiotic resistance, makes immunopotentiation an attractive complementary or alternative strategy to enhance resistance to bacterial biothreat agents. Francisella tularensis, Yersinia pestis, Bacillus anthracis, and Burkholderia mallei or pseudomallei can all be easily disseminated via the respiratory route and infections can result in high mortality rates. Therefore, there has been a marked increase in research on immunotherapeutics against these Tier 1 select agents over the last 10 years that will be covered in this review. In addition, immunopotentiation against non-Tier 1 select agents such as Brucella spp., and Coxiella burnetii has also been studied and will be reviewed here. In particular, we will focus on cellular targets, such as toll-like receptors (TLRs), carbohydrate receptors and cytokine receptors, which have been exploited by immunomodulatory regimens that confer broad-spectrum protection against virulent bacterial pathogens. PMID:25373479

  9. Bacterial microflora of nectarines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microflora of fruit surfaces has been the best source of antagonists against fungi causing postharvest decays of fruit. However, there is little information on microflora colonizing surfaces of fruits other than grapes, apples, and citrus fruit. We characterized bacterial microflora on nectarine f...

  10. BACTERIAL WATERBORNE PATHOGENS

    EPA Science Inventory

    Bacterial pathogens are examples of classical etiological agents of waterborne disease. While these agents no longer serve as major threats to U.S. water supplies, they are still important pathogens in areas with substandard sanitation and poor water treatment facilities. In th...

  11. Bacterial leaf spot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial leaf spot has been reported in Australia (Queensland), Egypt, El Salvador, India, Japan, Nicaragua, Sudan, and the United States (Florida, Iowa, Kansas, Maryland, and Wisconsin). It occasionally causes locally severe defoliation and post-emergence damping-off and stunting. The disease is...

  12. Bacterial extracellular lignin peroxidase

    DOEpatents

    Crawford, Donald L.; Ramachandra, Muralidhara

    1993-01-01

    A newly discovered lignin peroxidase enzyme is provided. The enzyme is obtained from a bacterial source and is capable of degrading the lignin portion of lignocellulose in the presence of hydrogen peroxide. The enzyme is extracellular, oxidative, inducible by lignin, larch wood xylan, or related substrates and capable of attacking certain lignin substructure chemical bonds that are not degradable by fungal lignin peroxidases.

  13. Family Workshops

    ERIC Educational Resources Information Center

    Bennett, Dave; Rees-Jones, Tanny

    1978-01-01

    A Family Workshop is an informal, multidisciplined educational program for adults and children, organized by a team of teachers. This article discusses the Lavender Hill Family Workshop, one of many, which attempts to provide education in various subject areas for adults and for children while also integrating both objectives in order to educate…

  14. FAMILY GEMINIVIRIDAE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The International Committee on the Taxonomy of Viruses geminivirus study group has revised the description of the family Geminiviridae for inclusion in the ICTV 8th report. Characteristic features of each genus within the family is presented. Revised criteria for demarcation and nomenclature of vi...

  15. Family Empowerment.

    ERIC Educational Resources Information Center

    Sinclair, Mary F., Ed.; And Others

    1992-01-01

    This feature issue of IMPACT focuses on the empowerment of families with a member who has a developmental disability. It presents strategies and models for a collaborative, respectful approach to service provision, and presents the experiences of families in seeking support and assistance. Feature articles include "Two Generations of Disability: A…

  16. FAMILY POTYVIRIDAE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The International Committee on the Taxonomy of Viruses potyvirus study group has revised the description of the family Geminiviridae for inclusion in the ICTV 8th report. Characteristic features of each genus within the family is presented. Revised criteria for demarcation and nomenclature of vira...

  17. Family Life.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    Focuses on various aspects of mammal family life ranging from ways different species are born to how different mammals are raised. Learning activities include making butter from cream, creating birth announcements for mammals, and playing a password game on family life. (ML)

  18. Family, Extended

    ERIC Educational Resources Information Center

    Patton, Jessica Rae

    2006-01-01

    Parents are a child's first and most influential teacher. People hear this truism often, yet nowhere has the author seen it more taken to heart than at Tower Street Elementary School. The school's efforts to form a true partnership with students' families--from involving families in the first day of school, to the principal making home visits, to…

  19. Family Potyviridae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The International Committee on the Taxonomy of Viruses potyvirus study group has revised the description of the family Potyviridae for inclusion in the ICTV 9th report. Characteristic features of each genus within the family is presented. Revised criteria for demarcation and nomenclature of viral sp...

  20. Corticosteroids for Bacterial Keratitis

    PubMed Central

    Srinivasan, Muthiah; Mascarenhas, Jeena; Rajaraman, Revathi; Ravindran, Meenakshi; Lalitha, Prajna; Glidden, David V.; Ray, Kathryn J.; Hong, Kevin C.; Oldenburg, Catherine E.; Lee, Salena M.; Zegans, Michael E.; McLeod, Stephen D.; Lietman, Thomas M.; Acharya, Nisha R.

    2013-01-01

    Objective To determine whether there is a benefit in clinical outcomes with the use of topical corticosteroids as adjunctive therapy in the treatment of bacterial corneal ulcers. Methods Randomized, placebo-controlled, double-masked, multicenter clinical trial comparing prednisolone sodium phosphate, 1.0%, to placebo as adjunctive therapy for the treatment of bacterial corneal ulcers. Eligible patients had a culture-positive bacterial corneal ulcer and received topical moxifloxacin for at least 48 hours before randomization. Main Outcome Measures The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months from enrollment. Secondary outcomes included infiltrate/scar size, reepithelialization, and corneal perforation. Results Between September 1, 2006, and February 22, 2010, 1769 patients were screened for the trial and 500 patients were enrolled. No significant difference was observed in the 3-month BSCVA (−0.009 logarithm of the minimum angle of resolution [logMAR]; 95% CI, −0.085 to 0.068; P = .82), infiltrate/scar size (P = .40), time to reepithelialization (P = .44), or corneal perforation (P > .99). A significant effect of corticosteroids was observed in subgroups of baseline BSCVA (P = .03) and ulcer location (P = .04). At 3 months, patients with vision of counting fingers or worse at baseline had 0.17 logMAR better visual acuity with corticosteroids (95% CI, −0.31 to −0.02; P = .03) compared with placebo, and patients with ulcers that were completely central at baseline had 0.20 logMAR better visual acuity with corticosteroids (−0.37 to −0.04; P = .02). Conclusions We found no overall difference in 3-month BSCVA and no safety concerns with adjunctive corticosteroid therapy for bacterial corneal ulcers. Application to Clinical Practice Adjunctive topical corticosteroid use does not improve 3-month vision in patients with bacterial corneal ulcers. PMID:21987582

  1. Family Theory and Family Health Research

    PubMed Central

    Doherty, William J.

    1991-01-01

    Different family theories can be applied to different aspects of how families experience health and illness. The family health and illness cycle describes the phases of a family's experience, beginning with health promotion and risk reduction, then family vulnerability and disease onset or relapse, family illness appraisal, family acute response, and finally family adaptation to illness and recovery. For each phase, specific family theories that are most appropriate for guiding family and health research are discussed. PMID:21229056

  2. Viral and bacterial rhinitis.

    TOXLINE Toxicology Bibliographic Information

    Doyle WJ; Gentile DA; Skoner DP

    2007-01-01

    In contradistinction to the poetically inspired disjunction between the name and quality of a rose recited by Juliet in the famous quote from Shakespeare's play, disease labels used in the medical sciences need to have exact meaning to ensure that they communicate an accurate diagnosis and a valid treatment approach. Above, we presented a consistent nosology for rhinitis consequent to infection. There, we argued that the term "rhinitis" should be used to describe the condition of nasal mucosal pathology and that the rSSC be used to describe the appreciated expression of that pathology. In discussing viral and bacterial rhinitis, we conclude that former is consistent with a strict application of our nosology where the accompanying rSSC is usually referred to as cold or flu, but that the latter is not. Lacking direct evidence for bacterial infection of the nasal mucosa, bacterial rhinitis is better referred to as an acute bacterial infection of an adjacent compartment complicated by rhinitis (e.g., sinusitis complicated by rhinitis) or as "toxic rhinitis" complicated by bacterial infection. Interestingly, bacterial infection of the adjacent compartments is a frequent complication of viral rhinitis making "bacterial" rhinitis a complication of a complication of viral rhinitis. The antiviral and antibacterial host-defense mechanisms available to the nasal mucosa are multilayered and formidable. For this reason, nasal mucosal infection with extracellular bacterial pathogens is rarely established and infection with a broad range of upper respiratory viruses is self-limited with short duration morbidity and no mortality. However, in select subpopulations, those infections predispose to more serious complications associated with secondary bacterial, and perhaps viral, infection of the sinuses, middle ears, and lungs. The morbidity and mortality of these complications remains a concern, and strategies to decrease their frequency need to be formulated and tested in clinical trials. Because the viruses causing rhinitis are spread by interpersonal contact, the most appropriate and least expensive prophylactic measures are good hygiene and contact avoidance. Prophylactic efficacy for vaccination and passive immunoglobulin therapy was demonstrated for influenza and RSV infections, respectively. However, these approaches hold little promise for other viruses and are associated with some risks, making them less acceptable for populations "at low risk" for the more serious complications of viral rhinitis. Existing pharmacological treatments for viral rhinitis target the effector chemicals of the rSSC and therefore are largely palliative, whereas antiviral treatment has limited theoretical and realized efficacy, and no treatment has been shown to decrease the risk of complications. Indeed, given the small treatment window available (time between rSSC onset and typical resolution) and the poor understanding of the immune/inflammatory pathways of host defense, it is doubtful that the general population's demand for a cure will be satisfied in the near future, but then, viral rhinitis by any other name is still just a cold.

  3. Positively regulated bacterial expression systems

    PubMed Central

    Brautaset, Trygve; Lale, Rahmi; Valla, Svein

    2009-01-01

    Summary Regulated promoters are useful tools for many aspects related to recombinant gene expression in bacteria, including for high‐level expression of heterologous proteins and for expression at physiological levels in metabolic engineering applications. In general, it is common to express the genes of interest from an inducible promoter controlled either by a positive regulator or by a repressor protein. In this review, we discuss established and potentially useful positively regulated bacterial promoter systems, with a particular emphasis on those that are controlled by the AraC‐XylS family of transcriptional activators. The systems function in a wide range of microorganisms, including enterobacteria, soil bacteria, lactic bacteria and streptomycetes. The available systems that have been applied to express heterologous genes are regulated either by sugars (l‐arabinose, l‐rhamnose, xylose and sucrose), substituted benzenes, cyclohexanone‐related compounds, ε‐caprolactam, propionate, thiostrepton, alkanes or peptides. It is of applied interest that some of the inducers require the presence of transport systems, some are more prone than others to become metabolized by the host and some have been applied mainly in one or a limited number of species. Based on bioinformatics analyses, the AraC‐XylS family of regulators contains a large number of different members (currently over 300), but only a small fraction of these, the XylS/Pm, AraC/PBAD, RhaR‐RhaS/rhaBAD, NitR/PnitA and ChnR/Pb regulator/promoter systems, have so far been explored for biotechnological applications. PMID:21261879

  4. Family Health and Family Planning.

    ERIC Educational Resources Information Center

    World Health Organization, Copenhagen (Denmark). Regional Office for Europe.

    This document is made up of a selection of some of the papers distributed to participants in courses on "Family Health and Family Planning" which have been organized each year since 1973 by the International Children's Center and the World Health Organization Regional Office for Europe. Six courses, held between 1973 and 1978, brought together a

  5. Family Health and Family Planning.

    ERIC Educational Resources Information Center

    World Health Organization, Copenhagen (Denmark). Regional Office for Europe.

    This document is made up of a selection of some of the papers distributed to participants in courses on "Family Health and Family Planning" which have been organized each year since 1973 by the International Children's Center and the World Health Organization Regional Office for Europe. Six courses, held between 1973 and 1978, brought together a…

  6. Bacterial Cell Wall Components

    NASA Astrophysics Data System (ADS)

    Ginsberg, Cynthia; Brown, Stephanie; Walker, Suzanne

    Bacterial cell-surface polysaccharides cells are surrounded by a variety of cell-surface structures that allow them to thrive in extreme environments. Components of the cell envelope and extracellular matrix are responsible for providing the cells with structural support, mediating intercellular communication, allowing the cells to move or to adhere to surfaces, protecting the cells from attack by antibiotics or the immune system, and facilitating the uptake of nutrients. Some of the most important cell wall components are polysaccharide structures. This review discusses the occurrence, structure, function, and biosynthesis of the most prevalent bacterial cell surface polysaccharides: peptidoglycan, lipopolysaccharide, arabinogalactan, and lipoarabinomannan, and capsular and extracellular polysaccharides. The roles of these polysaccharides in medicine, both as drug targets and as therapeutic agents, are also described.

  7. Bacterial-induced diarrhoea.

    PubMed

    Velásquez Jones, L; Rodríguez, R S

    1988-01-01

    In diverse parts of the world, many bacterial strains have been recognised as the causative agents of diarrhoea. Great achievements have been made in perceiving the varied mechanisms which explain their intestinal pathogenicity. These achievements include the elucidation of the 5 mechanisms of disease production by Escherichia coli, the mechanisms of action of Shigella, Salmonella, Campylobacter and Yersinia, new information about antimicrobial-associated colitis caused by Clostridium difficile and the recognition of microbes such as Aeromonas hydrophila and Pleisomonas shigelloides. Information is available on the use and indications of antimicrobial treatment in children with diarrhoea of bacterial aetiology which is proven or suspected by clinical symptomatology or simple laboratory procedures. Finally, the usefulness of oral rehydrating solutions has been appreciated in the prevention as well as in the correction of diarrhoeal dehydration. PMID:3069445

  8. [Bacterial diseases of rape].

    PubMed

    Zakharova, O M; Mel'nychuk, M D; Dankevych, L A; Patyka, V P

    2012-01-01

    Bacterial destruction of the culture was described and its agents identified in the spring and winter rape crops. Typical symptoms are the following: browning of stem tissue and its mucilagization, chlorosis of leaves, yellowing and beginning of soft rot in the place of leaf stalks affixion to stems, loss of pigmentation (violet). Pathogenic properties of the collection strains and morphological, cultural, physiological, and biochemical properties of the agents of rape's bacterial diseases isolated by the authors have been investigated. It was found that all the isolates selected by the authors are highly or moderately aggressive towards different varieties of rape. According to the complex of phenotypic properties 44% of the total number of isolates selected by the authors are related to representatives of the genus Pseudomonas, 37% - to Xanthomonas and 19% - to Pectobacterium. PMID:23293826

  9. Bacterial Genome Instability

    PubMed Central

    Darmon, Elise

    2014-01-01

    SUMMARY Bacterial genomes are remarkably stable from one generation to the next but are plastic on an evolutionary time scale, substantially shaped by horizontal gene transfer, genome rearrangement, and the activities of mobile DNA elements. This implies the existence of a delicate balance between the maintenance of genome stability and the tolerance of genome instability. In this review, we describe the specialized genetic elements and the endogenous processes that contribute to genome instability. We then discuss the consequences of genome instability at the physiological level, where cells have harnessed instability to mediate phase and antigenic variation, and at the evolutionary level, where horizontal gene transfer has played an important role. Indeed, this ability to share DNA sequences has played a major part in the evolution of life on Earth. The evolutionary plasticity of bacterial genomes, coupled with the vast numbers of bacteria on the planet, substantially limits our ability to control disease. PMID:24600039

  10. Bacterial multidrug efflux transporters.

    PubMed

    Delmar, Jared A; Su, Chih-Chia; Yu, Edward W

    2014-01-01

    Infections caused by bacteria are a leading cause of death worldwide. Although antibiotics remain a key clinical therapy, their effectiveness has been severely compromised by the development of drug resistance in bacterial pathogens. Multidrug efflux transporters--a common and powerful resistance mechanism--are capable of extruding a number of structurally unrelated antimicrobials from the bacterial cell, including antibiotics and toxic heavy metal ions, facilitating their survival in noxious environments. Transporters of the resistance-nodulation-cell division (RND) superfamily typically assemble as tripartite efflux complexes spanning the inner and outer membranes of the cell envelope. In Escherichia coli, the CusCFBA complex, which mediates resistance to copper(I) and silver(I) ions, is the only known RND transporter specific to heavy metals. Here, we describe the current knowledge of individual pump components of the Cus system, a paradigm for efflux machinery, and speculate on how RND pumps assemble to fight diverse antimicrobials. PMID:24702006

  11. Physics of Bacterial Morphogenesis

    PubMed Central

    Sun, Sean X.; Jiang, Hongyuan

    2011-01-01

    Summary: Bacterial cells utilize three-dimensional (3D) protein assemblies to perform important cellular functions such as growth, division, chemoreception, and motility. These assemblies are composed of mechanoproteins that can mechanically deform and exert force. Sometimes, small-nucleotide hydrolysis is coupled to mechanical deformations. In this review, we describe the general principle for an understanding of the coupling of mechanics with chemistry in mechanochemical systems. We apply this principle to understand bacterial cell shape and morphogenesis and how mechanical forces can influence peptidoglycan cell wall growth. We review a model that can potentially reconcile the growth dynamics of the cell wall with the role of cytoskeletal proteins such as MreB and crescentin. We also review the application of mechanochemical principles to understand the assembly and constriction of the FtsZ ring. A number of potential mechanisms are proposed, and important questions are discussed. PMID:22126993

  12. The Bacterial Cytoskeleton

    PubMed Central

    Shih, Yu-Ling; Rothfield, Lawrence

    2006-01-01

    In recent years it has been shown that bacteria contain a number of cytoskeletal structures. The bacterial cytoplasmic elements include homologs of the three major types of eukaryotic cytoskeletal proteins (actin, tubulin, and intermediate filament proteins) and a fourth group, the MinD-ParA group, that appears to be unique to bacteria. The cytoskeletal structures play important roles in cell division, cell polarity, cell shape regulation, plasmid partition, and other functions. The proteins self-assemble into filamentous structures in vitro and form intracellular ordered structures in vivo. In addition, there are a number of filamentous bacterial elements that may turn out to be cytoskeletal in nature. This review attempts to summarize and integrate the in vivo and in vitro aspects of these systems and to evaluate the probable future directions of this active research field. PMID:16959967

  13. Formation of bacterial nanocells

    NASA Astrophysics Data System (ADS)

    Vainshtein, Mikhail; Kudryashova, Ekaterina; Suzina, Natalia; Ariskina, Elena; Voronkov, Vadim

    1998-07-01

    Existence of nanobacteria received increasing attention both in environmental microbiology/geomicro-biology and in medical microbiology. In order to study a production of nanoforms by typical bacterial cells. Effects of different physical factors were investigated. Treatment of bacterial cultures with microwave radiation, or culturing in field of electric current resulted in formation a few types of nanocells. The number and type of nanoforms were determined with type and dose of the treatment. The produced nanoforms were: i) globules, ii) clusters of the globules--probably produced by liaison, iii) nanocells coated with membrane. The viability of the globules is an object opened for doubts. The nanocells discovered multiplication and growth on solidified nutrient media. The authors suggest that formation of nanocells is a common response of bacteria to stress-actions produced by different agents.

  14. Bacterial transformation of terpenoids

    NASA Astrophysics Data System (ADS)

    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.

  15. Neglected Bacterial Zoonoses

    PubMed Central

    Chikeka, Ijeuru; Dumler, J. Stephen

    2015-01-01

    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. While 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 a broad spectrum diagnoses are actively sought. Thus, 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. PMID:25964152

  16. Bacterial efflux pump inhibitors.

    PubMed

    Kamicker, Barbara J; Sweeney, Michael T; Kaczmarek, Frank; Dib-Hajj, Fadia; Shang, Wenchi; Crimin, Kim; Duignan, Joan; Gootz, Thomas D

    2008-01-01

    Infections caused by multidrug-resistant Gram-negative pathogens play a major role in the morbidity and mortality of hospitalized patients. The rise of resistance to current antibiotic therapies has made the discovery of new agents urgent. One of the major antibiotic resistance mechanisms utilized by more than 15 species of Gram-negative bacterial cells is the Resistance Nodulation Division (RND) efflux pump, which eliminates several classes of antibiotics such as penicillins and cephalosporin macrolides aminoglycosides, fluoroquinolonesx and tetracyclines. Here we describe a multistep process to identify compounds that inhibit the RND-type efflux pumps. This involves measuring the inhibition of accumulation of ethidium bromide in E. coli or Haemophilus influenzae cells and confirming that the inhibition is specific for the efflux pumps by using genetic constructs and biochemical methods to measure nonspecific inhibition due to e.g. intrinsic antibacterial activity or membrane disruption. In whole bacterial cells synergism antagonism or indifference of the combination of an antibiotic with the putative inhibitor is determined and this is then confirmed by quantitating viable bacterial cells in liquid culture over 24 h. PMID:18437315

  17. Neglected bacterial zoonoses.

    PubMed

    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. PMID:25964152

  18. Family Issues

    MedlinePlus

    ... Tips for Working with Individuals on the Autism Spectrum Residential/Housing Social/Relationships Self-Advocacy Navigating Services Autism Source Legal Resources Treatment Options Nonmedical Interventions Related Approaches Evaluating Options Family Issues Stress Siblings ...

  19. Family Issues

    MedlinePlus

    ... can lead to conflict, such as illness, disability, addiction, job loss, school problems, and marital issues. Listening to each other and working to resolve conflicts are important in strengthening the family.

  20. Heme uptake in bacterial pathogens

    PubMed Central

    Contreras, Heidi; Chim, Nicholas; Credali, Alfredo; Goulding, Celia W.

    2014-01-01

    Iron is an essential nutrient for the survival of organisms. Bacterial pathogens possess specialized pathways to acquire heme from their human hosts. In this review, we present recent structural and biochemical data that provide mechanistic insights into several bacterial heme uptake pathways, encompassing the sequestration of heme from human hemoproteins to secreted or membrane-associated bacterial proteins, the transport of heme across bacterial membranes, and the degradation of heme within the bacterial cytosol to liberate iron. The pathways for heme transport into the bacterial cytosol are divergent, harboring non-homologous protein sequences, novel structures, varying numbers of proteins, and different mechanisms. Congruously, the breakdown of heme within the bacterial cytosol by sequence-divergent proteins releases iron and distinct degradation products. PMID:24780277

  1. Evolutionary transitions in bacterial symbiosis

    PubMed Central

    Sachs, Joel L.; Skophammer, Ryan G.; Regus, John U.

    2011-01-01

    Diverse bacterial lineages form beneficial infections with eukaryotic hosts. The origins, evolution, and breakdown of these mutualisms represent important evolutionary transitions. To examine these key events, we synthesize data from diverse interactions between bacteria and eukaryote hosts. Five evolutionary transitions are investigated, including the origins of bacterial associations with eukaryotes, the origins and subsequent stable maintenance of bacterial mutualism with hosts, the capture of beneficial symbionts via the evolution of strict vertical transmission within host lineages, and the evolutionary breakdown of bacterial mutualism. Each of these transitions has occurred many times in the history of bacterial–eukaryote symbiosis. We investigate these evolutionary events across the bacterial domain and also among a focal set of well studied bacterial mutualist lineages. Subsequently, we generate a framework for examining evolutionary transitions in bacterial symbiosis and test hypotheses about the selective, ecological, and genomic forces that shape these events. PMID:21690339

  2. Importance of Family Routines

    MedlinePlus

    ... Life Family Life Family Life Medical Home Family Dynamics Media Work & Play Getting Involved in Your Community ... Find a Pediatrician Family Life Medical Home Family Dynamics Adoption & Foster Care Communication & Discipline Types of Families ...

  3. Roles within the Family

    MedlinePlus

    ... Life Family Life Family Life Medical Home Family Dynamics Media Work & Play Getting Involved in Your Community ... Find a Pediatrician Family Life Medical Home Family Dynamics Adoption & Foster Care Communication & Discipline Types of Families ...

  4. Bacterial Enzymes and Antibiotic Resistance- Oral Presentation

    SciTech Connect

    Maltz, Lauren

    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.

  5. Bacterial polyesters: biosynthesis, biodegradable plastics and biotechnology.

    PubMed

    Lenz, Robert W; Marchessault, Robert H

    2005-01-01

    The discovery and chemical identification, in the 1920s, of the aliphatic polyester: poly(3-hydroxybutyrate), PHB, as a granular component in bacterial cells proceeded without any of the controversies which marked the recognition of macromolecules by Staudinger. Some thirty years after its discovery, PHB was recognized as the prototypical biodegradable thermoplastic to solve the waste disposal challenge. The development effort led by Imperial Chemical Industries Ltd., encouraged interdisciplinary research from genetic engineering and biotechnology to the study of enzymes involved in biosynthesis and biodegradation. From the simple PHB homopolyester discovered by Maurice Lemoigne in the mid-twenties, a family of over 100 different aliphatic polyesters of the same general structure has been discovered. Depending on bacterial species and substrates, these high molecular weight stereoregular polyesters have emerged as a new family of natural polymers ranking with nucleic acids, polyamides, polyisoprenoids, polyphenols, polyphosphates, and polysaccharides. In this historical review, the chemical, biochemical and microbial highlights are linked to personalities and locations involved with the events covering a discovery timespan of 75 years. PMID:15638495

  6. SLC9/NHE gene family, a plasma membrane and organellar family of Na+/H+ exchangers *

    PubMed Central

    Donowitz, Mark; Tse, C. Ming; Fuster, Daniel

    2013-01-01

    This brief review of the human Na/H exchanger gene family introduces a new classification with three subgroups to the SLC9 gene family. Progress in the structure and function of this gene family is reviewed with structure based on homology to the bacterial Na/H exchanger NhaA. Human diseases which result from genetic abnormalities of the SLC9 family are discussed although the exact role of these transporters in causing any disease is not established, other than poorly functioning NHE3 in congenital Na diarrhea PMID:23506868

  7. Updating the Vibrio clades defined by multilocus sequence phylogeny: proposal of eight new clades, and the description of Vibrio tritonius sp. nov.

    PubMed Central

    Sawabe, Tomoo; Ogura, Yoshitoshi; Matsumura, Yuta; Feng, Gao; Amin, AKM Rohul; Mino, Sayaka; Nakagawa, Satoshi; Sawabe, Toko; Kumar, Ramesh; Fukui, Yohei; Satomi, Masataka; Matsushima, Ryoji; Thompson, Fabiano L.; Gomez-Gil, Bruno; Christen, Richard; Maruyama, Fumito; Kurokawa, Ken; Hayashi, Tetsuya

    2013-01-01

    To date 142 species have been described in the Vibrionaceae family of bacteria, classified into seven genera; Aliivibrio, Echinimonas, Enterovibrio, Grimontia, Photobacterium, Salinivibrio and Vibrio. As vibrios are widespread in marine environments and show versatile metabolisms and ecologies, these bacteria are recognized as one of the most diverse and important marine heterotrophic bacterial groups for elucidating the correlation between genome evolution and ecological adaptation. However, on the basis of 16S rRNA gene phylogeny, we could not find any robust monophyletic lineages in any of the known genera. We needed further attempts to reconstruct their evolutionary history based on multilocus sequence analysis (MLSA) and/or genome wide taxonomy of all the recognized species groups. In our previous report in 2007, we conducted the first broad multilocus sequence analysis (MLSA) to infer the evolutionary history of vibrios using nine housekeeping genes (the 16S rRNA gene, gapA, gyrB, ftsZ, mreB, pyrH, recA, rpoA, and topA), and we proposed 14 distinct clades in 58 species of Vibrionaceae. Due to the difficulty of designing universal primers that can amplify the genes for MLSA in every Vibrionaceae species, some clades had yet to be defined. In this study, we present a better picture of an updated molecular phylogeny for 86 described vibrio species and 10 genome sequenced Vibrionaceae strains, using 8 housekeeping gene sequences. This new study places special emphasis on (1) eight newly identified clades (Damselae, Mediterranei, Pectenicida, Phosphoreum, Profundum, Porteresiae, Rosenbergii, and Rumoiensis); (2) clades amended since the 2007 proposal with recently described new species; (3) orphan clades of genomospecies F6 and F10; (4) phylogenetic positions defined in 3 genome-sequenced strains (N418, EX25, and EJY3); and (5) description of V. tritonius sp. nov., which is a member of the “Porteresiae” clade. PMID:24409173

  8. Interactions between model bacterial membranes and synthetic antimicrobials.

    NASA Astrophysics Data System (ADS)

    Yang, Lihua; Mishra, Abhijit; Som, Abhigyan; Tew, Gregory N.; Wong, Gerard C. L.

    2006-03-01

    Antimicrobial peptides comprise a key component of innate immunity for a wide range of multicellular organisms. It has been shown that natural antimicrobial peptides and their analogs can permeate bacterial membranes selectively. There are a number of proposed models for this action, but the detailed molecular mechanism of the induced membrane permeation remains unclear. We investigate interactions between model bacterial membranes and a prototypical family of phenylene ethynylene-based antimicrobials with controllable hydrophilic and hydrophobic volume fractions, controllable charge placement. Preliminary results from synchrotron small angle x-ray scattering (SAXS) results will be presented.

  9. Bacterial terpene cyclases.

    PubMed

    Dickschat, Jeroen S

    2016-01-01

    Covering: up to 2015. This review summarises the accumulated knowledge about characterised bacterial terpene cyclases. The structures of identified products and of crystallised enzymes are included, and the obtained insights into enzyme mechanisms are discussed. After a summary of mono-, sesqui- and diterpene cyclases the special cases of the geosmin and 2-methylisoborneol synthases that are both particularly widespread in bacteria will be presented. A total number of 63 enzymes that have been characterised so far is presented, with 132 cited references. PMID:26563452

  10. Small Intestinal Bacterial Overgrowth

    PubMed Central

    Dukowicz, Andrew C.; Levine, Gary M.

    2007-01-01

    Small intestinal bacterial overgrowth (SIBO), defined as excessive bacteria in the small intestine, remains a poorly understood disease. Initially thought to occur in only a small number of patients, it is now apparent that this disorder is more prevalent than previously thought. Patients with SIBO vary in presentation, from being only mildly symptomatic to suffering from chronic diarrhea, weight loss, and malabsorption. A number of diagnostic tests are currently available, although the optimal treatment regimen remains elusive. Recently there has been renewed interest in SIBO and its putative association with irritable bowel syndrome. In this comprehensive review, we will discuss the epidemiology, pathogenesis, clinical manifestations, diagnosis, and treatment of SIBO. PMID:21960820

  11. Family II. Leptospiraceae Hovind-Hougen 1979, 245AL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacteria within the Family Leptospiraceae comprise a diverse group of three bacterial genera, Leptospira, Leptonema, and Turneriella. These bacteria are aerobes that consume long-chain fatty acids and alcohols as carbon and energy sources. Some members of this Family cause serious infections in ani...

  12. Familial Hypercholesterolemia.

    PubMed

    Bouhairie, Victoria Enchia; Goldberg, Anne Carol

    2016-03-01

    Familial hypercholesterolemia is a common, inherited disorder of cholesterol metabolism that leads to early cardiovascular morbidity and mortality. It is underdiagnosed and undertreated. Statins, ezetimibe, bile acid sequestrants, niacin, lomitapide, mipomersen, and low-density lipoprotein (LDL) apheresis are treatments that can lower LDL cholesterol levels. Early treatment can lead to substantial reduction of cardiovascular events and death in patients with familial hypercholesterolemia. It is important to increase awareness of this disorder in physicians and patients to reduce the burden of this disorder. PMID:26892994

  13. Familial hypercholesterolemia.

    PubMed

    Bouhairie, Victoria Enchia; Goldberg, Anne Carol

    2015-05-01

    Familial hypercholesterolemia is a common, inherited disorder of cholesterol metabolism that leads to early cardiovascular morbidity and mortality. It is underdiagnosed and undertreated. Statins, ezetimibe, bile acid sequestrants, niacin, lomitapide, mipomersen, and low-density lipoprotein (LDL) apheresis are treatments that can lower LDL cholesterol levels. Early treatment can lead to substantial reduction of cardiovascular events and death in patients with familial hypercholesterolemia. It is important to increase awareness of this disorder in physicians and patients to reduce the burden of this disorder. PMID:25939291

  14. Novel microarray design strategy to study complex bacterial communities.

    PubMed

    Huyghe, Antoine; Francois, Patrice; Charbonnier, Yvan; Tangomo-Bento, Manuela; Bonetti, Eve-Julie; Paster, Bruce J; Bolivar, Ignacio; Baratti-Mayer, Denise; Pittet, Didier; Schrenzel, Jacques

    2008-03-01

    Assessing bacterial flora composition appears to be of increasing importance to fields as diverse as physiology, development, medicine, epidemiology, the environment, and the food industry. We report here the development and validation of an original microarray strategy that allows analysis of the phylogenic composition of complex bacterial mixtures. The microarray contains approximately 9,500 feature elements targeting 16S rRNA gene-specific regions. Probe design was performed by selecting oligonucleotide sequences specific to each node of the seven levels of the bacterial phylogenetic tree (domain, phylum, class, order, family, genus, and species). This approach, based on sequence information, allows analysis of the bacterial contents of complex bacterial mixtures to detect both known and unknown microorganisms. The presence of unknown organisms can be suspected and mapped on the phylogenetic tree, indicating where to refine analysis. Initial proof-of-concept experiments were performed on oral bacterial communities. Our results show that this hierarchical approach can reveal minor changes (

  15. Animal Models of Bacterial Keratitis

    PubMed Central

    Marquart, Mary E.

    2011-01-01

    Bacterial keratitis is a disease of the cornea characterized by pain, redness, inflammation, and opacity. Common causes of this disease are Pseudomonas aeruginosa and Staphylococcus aureus. Animal models of keratitis have been used to elucidate both the bacterial factors and the host inflammatory response involved in the disease. Reviewed herein are animal models of bacterial keratitis and some of the key findings in the last several decades. PMID:21274270

  16. [Endogenous bacterial endophthalmitis].

    PubMed

    Cornut, P-L; Chiquet, C

    2011-01-01

    Endogenous bacterial endophthalmitis, also called metastatic bacterial endophthalmitis, remains a diagnostic and therapeutic challenge. It is a rare and potentially sight-threatening ocular infection that occurs when bacteria reach the eye via the bloodstream, cross the blood-ocular barrier, and multiply within the eye. It usually affects immunocompromised patients and those suffering from diabetes mellitus, malignancy, or cardiac disease, but has also been reported after invasive procedures or in previously healthy people. In most cases, the ocular symptoms occur after the diagnosis of septicemia or systemic infection. Ocular symptoms include decreased vision, redness, discharge, pain, and floaters. The ocular inflammatory signs may be anterior and/or posterior. Bilateral involvement occurs in nearly 25% of cases. A wide range of microorganisms are involved, with differences in their frequency according to geography as well as the patient's age and past medical history, because of variations in the predisposing conditions and the source of the sepsis. The majority of patients are initially misdiagnosed, and ophthalmologists should be aware of this because prompt local and general management is required to save the eye and/or the patient's life. PMID:21145128

  17. Optimality in Bacterial Chemotaxis

    NASA Astrophysics Data System (ADS)

    Vladimirov, Nikita; Lebiedz, Dirk; Sourjik, Victor

    2010-03-01

    One of the central questions of systems biology is the role of microscopic parameters of a single cell in the behavior of population. Multiscale models address this problem, allowing us to understand population behavior from single-cell molecular components and reactions. In this work a multiscale (hybrid) model is presented, which describes chemotactic Escherichia coli bacterium by combination of mathematical models and time-scale separation of key reactions. The bacterial behavior is described with high accuracy according to the available experimental data. The model shows several new aspects of chemotactic optimality in terms of adaptation rate, gradient steepness and type of medium (liquid or porous). Also, it predicts existence of an additional mechanism of gradient navigation in E. coli. Based on the available experiments, the model suggests that tumbles are anisotropic, i.e. the angle of reorientation during a tumble depends on the swimming direction along the gradient. This result demonstrates a new level of optimization in E. coli chemotaxis, which is likely to be used by some other peritrichously flagellated bacteria, and indicates yet another level of evolutionary optimization in bacterial chemotaxis.

  18. Mechanism of Bacterial Oligosaccharyltransferase

    PubMed Central

    Gerber, Sabina; Lizak, Christian; Michaud, Gaëlle; Bucher, Monika; Darbre, Tamis; Aebi, Markus; Reymond, Jean-Louis; Locher, Kaspar P.

    2013-01-01

    N-Linked glycosylation is an essential post-translational protein modification in the eukaryotic cell. The initial transfer of an oligosaccharide from a lipid carrier onto asparagine residues within a consensus sequon is catalyzed by oligosaccharyltransferase (OST). The first X-ray structure of a complete bacterial OST enzyme, Campylobacter lari PglB, was recently determined. To understand the mechanism of PglB, we have quantified sequon binding and glycosylation turnover in vitro using purified enzyme and fluorescently labeled, synthetic peptide substrates. Using fluorescence anisotropy, we determined a dissociation constant of 1.0 μm and a strict requirement for divalent metal ions for consensus (DQNAT) sequon binding. Using in-gel fluorescence detection, we quantified exceedingly low glycosylation rates that remained undetected using in vivo assays. We found that an alanine in the −2 sequon position, converting the bacterial sequon to a eukaryotic one, resulted in strongly lowered sequon binding, with in vitro turnover reduced 50,000-fold. A threonine is preferred over serine in the +2 sequon position, reflected by a 4-fold higher affinity and a 1.2-fold higher glycosylation rate. The interaction of the +2 sequon position with PglB is modulated by isoleucine 572. Our study demonstrates an intricate interplay of peptide and metal binding as the first step of protein N-glycosylation. PMID:23382388

  19. Bacterial chemoreceptors and chemoeffectors.

    PubMed

    Bi, Shuangyu; Lai, Luhua

    2015-02-01

    Bacteria use chemotaxis signaling pathways to sense environmental changes. Escherichia coli chemotaxis system represents an ideal model that illustrates fundamental principles of biological signaling processes. Chemoreceptors are crucial signaling proteins that mediate taxis toward a wide range of chemoeffectors. Recently, in deep study of the biochemical and structural features of chemoreceptors, the organization of higher-order clusters in native cells, and the signal transduction mechanisms related to the on-off signal output provides us with general insights to understand how chemotaxis performs high sensitivity, precise adaptation, signal amplification, and wide dynamic range. Along with the increasing knowledge, bacterial chemoreceptors can be engineered to sense novel chemoeffectors, which has extensive applications in therapeutics and industry. Here we mainly review recent advances in the E. coli chemotaxis system involving structure and organization of chemoreceptors, discovery, design, and characterization of chemoeffectors, and signal recognition and transduction mechanisms. Possible strategies for changing the specificity of bacterial chemoreceptors to sense novel chemoeffectors are also discussed. PMID:25374297

  20. The bacterial gliding machinery

    NASA Astrophysics Data System (ADS)

    Shrivastava, Abhishek

    Cells of Flavobacterium johnsoniae, a rod-shaped bacterium, glide over surfaces with speeds reaching up to 2 micrometer's. Gliding is powered by a protonmotive force. The adhesin SprB forms filaments about 160 nm long that move on the cell-surface along a looped track. Interaction of SprB filaments with a surface produces gliding. We tethered F. johnsoniae cells to glass by adding anti-SprB antibody. Tethered cells spun about fixed points, rotating at speeds of about 1 Hz. The torques required to sustain such speeds were large, comparable to those generated by the flagellar rotary motor. Using a flow cell apparatus, we changed load on the gliding motor by adding the viscous agent Ficoll to tethered cells. We found that a gliding motor runs at constant speed rather than constant torque. We attached gold nanoparticles to the SprB filament and tracked its motion. We fluorescently tagged a bacterial Type IX secretion system (T9SS) protein and imaged its dynamics. Fluorescently tagged T9SS protein localized near the point of tether, indicating that T9SS localizes with the gliding motor. Based on our results, we propose a model to explain bacterial gliding.

  1. Multispectral bacterial identification

    NASA Astrophysics Data System (ADS)

    Tanner, Michael A.; Coleman, William J.; Everett, Christine L.; Robles, Steven J.; Dilworth, Michael R.; Yang, Mary M.; Youvan, Douglas C.

    2000-04-01

    A multi spectral optical technique was developed to simultaneously classify individual bacterial cells within mixed populations. Multi spectral Bacterial Identification (mBID) combines innovations in microscopy with a software analysis program to measure and characterize the fluorescence signals from multiplexed 16S ribosomal RNA probes hybridized to populations of different bacteria. Software was developed to identify individual bacteria at the level of species within these mixed populations. TO test the feasibility of mBID, we examined the fluorescence emissions from a mixture of probes specific for individual species of known bacteria from the American Type Culture Collection. Currently, up to seven species can be detected simultaneously by fluorescence microscopy. An eighth signal was reserved for a universal probe to control for fluorescence intensity. mBID can also be used to identify uncultured microorganisms. We plan to couple this new multi spectral technology to existing identification technologies that utilize 16S rRNA sequence alignment. Using this integrated identification protocol, bacteria that may be associated with chronic conditions will be identified first by analyzing their 16S rDNA sequences and then by visualizing them with flourescent probes hybridized to their 16S rRNA in situ.

  2. Insights from twenty years of bacterial genome sequencing

    SciTech Connect

    Land, Miriam L; Hauser, Loren John; Jun, Se Ran; Nookaew, Intawat; Leuze, Michael Rex; Ahn, Tae-Hyuk; Karpinets, Tatiana V; Lund, Ole; Kora, Guruprasad H; Wassenaar, Trudy; Poudel, Suresh; Ussery, David W

    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 sequencing? There are many practical applications, such as genome-scale metabolic modeling, biosurveillance, bioforensics, and infectious disease epidemiology. In the near future, high-throughput sequencing of patient metagenomic samples could revolutionize medicine in terms of speed and accuracy of finding pathogens and knowing how to treat them.

  3. Periodic growth of bacterial colonies

    NASA Astrophysics Data System (ADS)

    Yamazaki, Yoshihiro; Ikeda, Takemasa; Shimada, Hirotoshi; Hiramatsu, Fumiko; Kobayashi, Naoki; Wakita, Jun-ichi; Itoh, Hiroto; Kurosu, Sayuri; Nakatsuchi, Michio; Matsuyama, Tohey; Matsushita, Mitsugu

    2005-06-01

    The formation of concentric ring colonies by bacterial species Bacillus subtilis and Proteus mirabilis has been investigated experimentally, focusing our attention on the dependence of local cell density upon the bacterial motility. It has been confirmed that these concentric ring colonies reflect the periodic change of the bacterial motility between motile cell state and immotile cell state. We conclude that this periodic change is macroscopically determined neither by biological factors (i.e., biological clock) nor by chemical factors (chemotaxis as inhibitor). And our experimental results strongly suggest that the essential factor for the change of the bacterial motility during concentric ring formation is the local cell density.

  4. Nanoparticle Approaches against Bacterial Infections

    PubMed Central

    Gao, Weiwei; Thamphiwatana, Soracha; Angsantikul, Pavimol; Zhang, Liangfang

    2014-01-01

    Despite the wide success of antibiotics, the treatment of bacterial infection still faces significant challenges, particularly the emergence of antibiotic resistance. As a result, nanoparticle drug delivery platforms including liposomes, polymeric nanoparticles, dendrimers, and various inorganic nanoparticles have been increasingly exploited to enhance the therapeutic effectiveness of existing antibiotics. This review focuses on areas where nanoparticle approaches hold significant potential to advance the treatment of bacterial infection. These areas include targeted antibiotic delivery, environmentally responsive antibiotic delivery, combinatorial antibiotic delivery, nanoparticle-enabled antibacterial vaccination, and nanoparticle-based bacterial detection. In each area we highlight the innovative antimicrobial nanoparticle platforms and review their progress made against bacterial infections. PMID:25044325

  5. Genomics of Pathogenic Vibrio Species

    NASA Astrophysics Data System (ADS)

    Dziejman, Michelle; Yildiz, Fitnat H.

    Members of the heterotrophic bacterial family Vibrionaceae are native inhabitants of aquatic environments worldwide, constituting a diverse and abundant component of marine microbial organisms. Over 60 species of the genus Vibrio have been identified (Thompson et al., 2004) and their phenotypic heterogeneity is well documented. The ecology of the genus remains less well understood, however, despite reports that vibrios are the dominant microorganisms inhabiting the superficial water layer and colonizing the chitinous exoskeleton of zooplankton (e.g., copepods, Thompson et al., 2004). Although some species were originally isolated from seawater as free living organisms, most were isolated in association with marine life such as bivalves, fish, eels, or shrimp.

  6. Multiracial Families.

    ERIC Educational Resources Information Center

    Kenney, Kelley

    The multiracial population is one of the fastest growing segments of the U. S. population. In discussing the multiracial population it is first important to identify and define the groups that are under the heading of multiracial. The literature has included interracial couples, multiracial individuals, and families in which a cross-racial or…

  7. FAMILY TYMOVIRIDAE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article provides a brief review of the taxonomic structure, virion properties, genome organization and replication strategy, antigenic properties, and biological properties of viruses in the family Tymoviridae. Criteria for demarcation of genus and species are provided. A brief review of each...

  8. Family Violence.

    ERIC Educational Resources Information Center

    Sorgen, Carol, Ed.

    1979-01-01

    This quarterly publication, issued by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), contains articles dealing with family violence and alcohol abuse, children of alcoholic parents, training programs for counselors, and confidentiality of client records. The three articles on alcohol abuse suggest that: (1) there is a clear…

  9. Serving Families.

    ERIC Educational Resources Information Center

    Link, Geoffrey; Beggs, Marjorie; Seiderman, Ethel

    Parent Services Project (PSP), the first comprehensive program of resources and mental health activities for parents offered at child care centers in the San Francisco Bay Area (California), has expanded to centers in six states, serving over 19,000 families. This report describes the program's history, aims, and achievements, along with specific…

  10. Family Hypnotherapy.

    ERIC Educational Resources Information Center

    Araoz, Daniel L.; Negley-Parker, Esther

    1985-01-01

    A therapeutic model to help families activate experiential and right hemispheric functioning through hypnosis is presented in detail, together with a clinical illustration. Different situations in which this model is effective are mentioned and one such set of circumstances is described. (Author)

  11. Family Disruptions

    MedlinePlus

    ... is happening and how it might affect her relationship with her cousins. She also might ask you: "Are you and Dad going to get a divorce too?" It is unwise to protect your child from these kinds of family problems. Keep in mind that if she sees you becoming anxious, without ...

  12. Family Involvement.

    ERIC Educational Resources Information Center

    Nathanson, Jeanne H., Ed.

    1992-01-01

    This periodical issue focuses on the theme of involvement of families in the education of their children with disabilities. It includes papers with the following titles and authors: "A Message from the Assistant Secretary: Developing Successful Partnerships between Parents and Service Providers" (Robert R. Davila); "Parent Advocacy and Children…

  13. Epigenetics and Bacterial Infections

    PubMed Central

    Bierne, Hélène; Hamon, Mélanie; Cossart, Pascale

    2012-01-01

    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. PMID:23209181

  14. Bacterial contamination of allografts.

    PubMed

    Barrios, R H; Leyes, M; Amillo, S; Oteiza, C

    1994-01-01

    The risk of bacterial infection through allogenic bone transplantation is one of the major problems facing tissue banks. The purpose of this study is to report the contamination rate in 987 grafts obtained under strictly aseptic conditions, between 1989 and 1992. The grafts were stored at -80 degrees C (cortical bone and tendons) and -40 degrees C (cancellous bone). The overall contamination rate was 6.6%, with Gram-positive bacteria responsible for 80% of the positive cultures. We discuss the sources of contamination, the most frequently isolated bacteria and the steps in the donation and transplantation procedures that help to reduce the risk of contamination. We conclude that the methods of acquisition, processing and storage of tissues are effective in making sterile allografts available. PMID:8053313

  15. Bacterial contamination of allografts.

    PubMed

    Barrios, R H; Leyes, M; Amillo, S; Oteiza, C

    1994-01-01

    The risk of bacterial infection through allogeneic bone transplantation is one of the problems facing tissue banks. The purpose of this study is to report the contamination rate in 987 grafts obtained under strictly aseptic conditions, between 1989 and 1992. The grafts were stored at -80 degrees C (cortical bone and tendons) and -40 degrees C (cancellous bone). The overall contamination rate was 6.6%, with Gram-positive bacteria responsible for 80% of the positive cultures. We discuss the sources of contamination, the most frequently isolated bacteria and the steps in the donation and transplantation procedures that help to reduce the risk of contamination. We conclude that the methods of procurement, processing and storage of tissues are effective in making sterile allografts available. PMID:7992606

  16. [Modern bacterial vaccines].

    PubMed

    Mebel, S; Thilo, W

    1983-01-01

    A well founded vaccination strategy is of crucial importance for controlling communicable diseases. The WHO Enlarged Vaccination Programme of 1976 provides to protect by vaccination all children in the world against six infection diseases - diphtheria, pertussis, tetanus, measles, poliomyelitis, and tuberculosis, a sure immunization prophylaxis being possible against them. The perspectives of further development of some classical vaccines as against cholera, typhoid fever, and pertussis are reviewed. Some recent bacterial vaccines are discussed being of special significance for controlling nosocomial infections and for protecting patients in intensive therapy and/or persons with lowered immunological defence. New ways for production of vaccine matters are shown such as capsule polysaccharides, membrane proteins, subcellular fractions, and vaccines with synthetic carrier molecules. Fundamental problems concerning the initiation of vaccination and the demands for an enlarged proof of innocence of vaccines are discussed. PMID:6636867

  17. Sweet Talk: Protein Glycosylation in Bacterial Interaction With the Host.

    PubMed

    Lu, Qiuhe; Li, Shan; Shao, Feng

    2015-10-01

    Pathogenic bacteria encode virulent glycosyltransferases that conjugate various glycans onto substrate proteins via the N- or O-linkage. The HMW system in nontypeable Haemophilus influenzae and the Pgl system in Campylobacter jejuni glycosylate bacterial surface or periplasmic proteins at the eukaryotic-like Asn-X-Ser/Thr motif. The NleB effector from enterobacteria mediates arginine GlcNAcylation of host death-domain proteins to block inflammation, representing an atypical N-glycosylation. The large clostridial cytotoxins and related glucosyltransferase toxins from Legionella and Photorhabdus monoglycosylate a serine/threonine or tyrosine in host Rho GTPase or elongation factor 1A (eEF1A). The emerging bacterial autotransporter heptosyltransferase (BAHT) family of heptosyltransferases also catalyses O-glycosylation and modifies autotransporters for adhesion to the host. These glycosylations, diverse in linkages and glycan structures, determine appropriate functioning of bacterial virulence factors or hijack host cellular processes in pathogenesis. PMID:26433695

  18. A Common Fold Mediates Vertebrate Defense and Bacterial Attack

    SciTech Connect

    Rosado, Carlos J.; Buckle, Ashley M.; Law, Ruby H.P.; Butcher, Rebecca E.; Kan, Wan-Ting; Bird, Catherina H.; Ung, Kheng; Browne, Kylie A.; Baran, Katherine; Bashtannyk-Puhalovich, Tanya A.; Faux, Noel G.; Wong, Wilson; Porter, Corrine J.; Pike, Robert N.; Ellisdon, Andrew M.; Pearce, Mary C.; Bottomley, Stephen P.; Emsley, Jonas; Smith, A. Ian; Rossjohn, Jamie; Hartland, Elizabeth L.; Voskoboinik, Ilia; Trapani, Joseph A.; Bird, Phillip I.; Dunstone, Michelle A.; Whisstock, James C.

    2008-10-02

    Proteins containing membrane attack complex/perforin (MACPF) domains play important roles in vertebrate immunity, embryonic development, and neural-cell migration. In vertebrates, the ninth component of complement and perforin form oligomeric pores that lyse bacteria and kill virus-infected cells, respectively. However, the mechanism of MACPF function is unknown. We determined the crystal structure of a bacterial MACPF protein, Plu-MACPF from Photorhabdus luminescens, to 2.0 angstrom resolution. The MACPF domain reveals structural similarity with poreforming cholesterol-dependent cytolysins (CDCs) from Gram-positive bacteria. This suggests that lytic MACPF proteins may use a CDC-like mechanism to form pores and disrupt cell membranes. Sequence similarity between bacterial and vertebrate MACPF domains suggests that the fold of the CDCs, a family of proteins important for bacterial pathogenesis, is probably used by vertebrates for defense against infection.

  19. Targeted anti bacterial therapy.

    PubMed

    Yacoby, Iftach; Benhar, Itai

    2007-09-01

    The increasing development of bacterial resistance to traditional antibiotics has reached alarming levels, thus necessitating a strong need to develop new antimicrobial agents. These new antimicrobials should possess novel modes of action and/or different cellular targets compared with the existing antibiotics. As a result, new classes of compounds designed to avoid defined resistance mechanisms are undergoing pre clinical and clinical evaluation. Microbial and phage genomic sequencing are now being used to find previously unidentified genes and their corresponding proteins. In both traditional and newly developed antibiotics, the target selectivity lies in the drug itself, in its ability to affect a mechanism that is unique to prokaryotes. As a result, a vast number of potent agents that, due to low selectivity, in addition to the pathogen also affect the eukaryote host have been excluded from use as therapeutics. Such compounds could be re-considered for clinical use if applied as part of a targeted delivery platform where the drug selectivity is replaced by target-selectivity borne by the targeting moiety. With a large number of antibodies and antibody-drug conjugates already approved or near approval as cancer therapeutics, targeted therapy is becoming increasingly attractive and additional potential targeting moieties that are non-antibody based, such as peptides, non-antibody ligand-binding proteins and even carbohydrates are receiving increasing attention. Still, targeted therapy is mostly focused on cancer, with targeted anti bacterial therapies being suggested only very recently. This review will focus in the various methods of antimicrobial targeting, by systemic and local application of targeted antimicrobial substances. PMID:17897058

  20. Familial Hypercholesterolemia

    PubMed Central

    Pejic, Rade N.

    2014-01-01

    Background Familial hypercholesterolemia (FH) is an autosomal dominant-inherited genetic disorder that leads to elevated blood cholesterol levels. FH may present as severely elevated total cholesterol and low density lipoprotein (LDL) cholesterol levels or as premature coronary heart disease (CHD). Methods This review presents information on the disease and on the effects of drug treatment and lifestyle changes. Results Routine lipid testing should identify most patients with FH. Once an index case is identified, testing should be offered to family members. Early diagnosis and aggressive treatment with therapeutic lifestyle changes and statins can prevent premature CHD and other atherosclerotic sequelae in patients with FH. Conclusion Emerging therapies such as LDL apheresis and novel therapeutic agents may be useful in patients with homozygous FH or treatment-resistant FH. Liver transplantation is the only effective therapy for severe cases of homozygous FH. PMID:25598733

  1. Uncovering common bacterial skin infections.

    PubMed

    Napierkowski, Daria

    2013-03-10

    The four most common bacterial skin infections are impetigo, erysipelas, cellulitis, and folliculitis. This article summarizes current information about the etiology, clinical presentation, diagnosis, prevention, treatment, and implications for primary care practice needed to effectively diagnose and treat common bacterial skin infections. PMID:23361375

  2. Familial hypercholesterolemia

    PubMed Central

    Turgeon, Ricky D.; Barry, Arden R.; Pearson, Glen J.

    2016-01-01

    Objective To summarize the pathophysiology, epidemiology, screening, diagnosis, and treatment of familial hypercholesterolemia (FH). Quality of evidence A PubMed search was conducted (inception to July 2014) for articles on pathophysiology, screening, diagnosis, and management of FH, supplemented with hand searches of bibliographies of guidelines and reviews. A supporting level of evidence for each recommendation was categorized as level I (randomized controlled trial or systematic review of randomized controlled trials), level II (observational study), or level III (expert opinion). The best available evidence is mostly level II or III. Main message Familial hypercholesterolemia affects 1 in 500 Canadians. Risk of a coronary event is high in these patients and is underestimated by risk calculators (eg, Framingham). Clinicians should screen patients according to guidelines and suspect FH in any patient with a premature cardiovascular event, physical stigmata of hypercholesterolemia, or an elevated plasma lipid level. Physicians should diagnose FH using either the Simon Broome or Dutch Lipid Network criteria. Management of heterozygous FH includes reducing low-density lipoprotein levels by 50% or more from baseline with high-dose statins and other lipid-lowering agents. Clinicians should refer any patient with homozygous FH to a specialized centre. Conclusion Familial hypercholesterolemia represents an important cause of premature cardiovascular disease in Canadians. Early identification and aggressive treatment of individuals with FH reduces cardiovascular morbidity and mortality. PMID:26796832

  3. Current challenges in bacterial transcriptomics.

    PubMed

    Cho, Suhyung; Cho, Yoobok; Lee, Sooin; Kim, Jayoung; Yum, Hyeji; Kim, Sun Chang; Cho, Byung-Kwan

    2013-06-01

    Over the past decade or so, dramatic developments in our ability to experimentally determine the content and function of genomes have taken place. In particular, next-generation sequencing technologies are now inspiring a new understanding of bacterial transcriptomes on a global scale. In bacterial cells, whole-transcriptome studies have not received attention, owing to the general view that bacterial genomes are simple. However, several recent RNA sequencing results are revealing unexpected levels of complexity in bacterial transcriptomes, indicating that the transcribed regions of genomes are much larger and complex than previously anticipated. In particular, these data show a wide array of small RNAs, antisense RNAs, and alternative transcripts. Here, we review how current transcriptomics are now revolutionizing our understanding of the complexity and regulation of bacterial transcriptomes. PMID:23843773

  4. Biochemistry and cell signaling taught by bacterial effectors.

    PubMed

    Cui, Jixin; Shao, Feng

    2011-10-01

    Bacterial virulence often relies on secreted effectors that modulate eukaryotic signal transduction. Recent studies provide a collection of examples in which bacterial effectors carry out unprecedented posttranslational modifications of key signaling molecules or organize a new signaling network. OspF and YopJ families of effectors use novel modification activities to block kinase phosphoactivation. Targeting of the ubiquitin system by IpaH and Cif/CHBP families provides insights into host ubiquitin signaling. Manipulation of small GTPases by VopS/IbpA and SidM suggests previously underappreciated regulation of signaling. Several other effectors, including SifA and EspG, organize newly discovered signaling networks in membrane trafficking. Studies of these effectors can generate new knowledge in enzyme catalysis and provide new angles for furthering our understanding of biochemical regulation of important signaling pathways. PMID:21920760

  5. Mechanism of uranium (VI) removal by two anaerobic bacterial communities.

    PubMed

    Martins, Mónica; Faleiro, Maria Leonor; da Costa, Ana M Rosa; Chaves, Sandra; Tenreiro, Rogério; Matos, António Pedro; Costa, Maria Clara

    2010-12-15

    The mechanism of uranium (VI) removal by two anaerobic bacterial consortia, recovered from an uncontaminated site (consortium A) and other from an uranium mine (consortium U), was investigated. The highest efficiency of U (VI) removal by both consortia (97%) occurred at room temperature and at pH 7.2. Furthermore, it was found that U (VI) removal by consortium A occurred by enzymatic reduction and bioaccumulation, while the enzymatic process was the only mechanism involved in metal removal by consortium U. FTIR analysis suggested that after U (VI) reduction, U (IV) could be bound to carboxyl, phosphate and amide groups of bacterial cells. Phylogenetic analysis of 16S rRNA showed that community A was mainly composed by bacteria closely related to Sporotalea genus and Rhodocyclaceae family, while community U was mainly composed by bacteria related to Clostridium genus and Rhodocyclaceae family. PMID:20832165

  6. Dual Career Families: A Family Therapy Perspective.

    ERIC Educational Resources Information Center

    Hill, Nicole R.

    This literature review provides an overview of the impact of dual careers on family and family therapy. The dual career family currently represents the most common married unit. Because both work and family stress impact psychological well-being variables such as depression and self-esteem, family and work can not be understood as two separate and…

  7. Bacterial Genotoxins: Merging the DNA Damage Response into Infection Biology

    PubMed Central

    Grasso, Francesca; Frisan, Teresa

    2015-01-01

    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. PMID:26270677

  8. IL-10 function, regulation, and in bacterial keratitis.

    PubMed

    Hazlett, Linda D; Jiang, Xiaoyu; McClellan, Sharon A

    2014-06-01

    The immune system protects the host from pathogenic microbes, but tight regulation of the evoked response is requisite to limit bystander damage. The interleukin (IL)-10 family of cytokines, composed of 9 members: IL-10, IL-19, IL-20, IL-22, IL-24, IL-26, and 3 distantly related members, IL-28A, IL-28B, and IL-29, plays a central role in this regulation. IL-10 family cytokines emerged before the adaptive immune response and elicit diverse host defense mechanisms, especially from epithelial cells during an infection. IL-10 family cytokines are also essential for maintenance and integrity of tissue epithelial layers. These cytokines promote innate immune responses from tissue epithelia that limit the damage caused by both viral and bacterial infections. They also facilitate tissue healing after infection/inflammation. In this regard, IL-10 suppresses pro-inflammatory responses, limiting tissue disruption resulting from an inflammatory response. Thus, a central functional theme of IL-10 family cytokines is their role in tissue protection. This review focuses on IL-10, the founding member of this family of cytokines, and integrates recent data on the function and regulation of IL-10 during bacterial infections. Emphasis is placed on the role of IL-10 in Pseudomonas aeruginosa keratitis and the subsequent infectious/inflammatory processes evoked. PMID:24738920

  9. Laboratory Diagnosis of Bacterial Gastroenteritis

    PubMed Central

    Humphries, Romney M.

    2015-01-01

    SUMMARY Bacterial gastroenteritis is a disease that is pervasive in both the developing and developed worlds. While for the most part bacterial gastroenteritis is self-limiting, identification of an etiological agent by bacterial stool culture is required for the management of patients with severe or prolonged diarrhea, symptoms consistent with invasive disease, or a history that may predict a complicated course of disease. Importantly, characterization of bacterial enteropathogens from stool cultures in clinical laboratories is one of the primary means by which public health officials identify and track outbreaks of bacterial gastroenteritis. This article provides guidance for clinical microbiology laboratories that perform stool cultures. The general characteristics, epidemiology, and clinical manifestations of key bacterial enteropathogens are summarized. Information regarding optimal specimen collection, transport, and processing and current diagnostic tests and testing algorithms is provided. This article is an update of Cumitech 12A (P. H. Gilligan, J. M. Janda, M. A. Karmali, and J. M. Miller, Cumitech 12A, Laboratory diagnosis of bacterial diarrhea, 1992). PMID:25567220

  10. Bacterial Inhibition by Electrical Stimulation.

    PubMed

    Asadi, Mohammad Reza; Torkaman, Giti

    2014-02-01

    Significance: Much evidence shows that electrical stimulation (ES) promotes the wound healing process. The inhibitory effect of ES on bacterial growth has been proposed as a mechanism to explain the useful effects of ES on wound healing. Bacterial burden has been associated with chronic wounds. The extensive use of antibiotics can lead to the spread of multiple drug resistant bacteria. Whether biophysical energies, such as ES, can be used as a treatment modality against pathogenic microorganisms remains an open question. Recent Advances: The research literature provides evidence for useful effects of ES in terms of inhibition of bacterial growth. The type of ES, its polarity, and the intensity of the current play a major role in establishment of antibacterial effects. Both direct current (DC) and high voltage pulse current are more effective at inhibiting bacterial growth than are other types of ES. The exact mechanism underlying the antibacterial effects of ES is not clear. Critical Issues: Available evidence indicates that microampere DC (?ADC) is better than other ES types for inhibition of bacterial growth. The results of most studies also support the application of cathodal current for bacterial growth inhibition. The current intensity of ES would appear to be tolerable by humans if used clinically for treatment of infected wounds. Future Directions: The cathodal ?ADC appears to be more effective for inhibition of microorganism growth. Further research, especially in vivo, is necessary to clarify the inhibitory effects of ES on wound bacterial infections. PMID:24761349

  11. Bacterial Origin of a Mitochondrial Outer Membrane Protein Translocase

    PubMed Central

    Harsman, Anke; Niemann, Moritz; Pusnik, Mascha; Schmidt, Oliver; Burmann, Björn M.; Hiller, Sebastian; Meisinger, Chris; Schneider, André; Wagner, Richard

    2012-01-01

    Mitochondria are of bacterial ancestry and have to import most of their proteins from the cytosol. This process is mediated by Tom40, an essential protein that forms the protein-translocating pore in the outer mitochondrial membrane. Tom40 is conserved in virtually all eukaryotes, but its evolutionary origin is unclear because bacterial orthologues have not been identified so far. Recently, it was shown that the parasitic protozoon Trypanosoma brucei lacks a conventional Tom40 and instead employs the archaic translocase of the outer mitochondrial membrane (ATOM), a protein that shows similarities to both eukaryotic Tom40 and bacterial protein translocases of the Omp85 family. Here we present electrophysiological single channel data showing that ATOM forms a hydrophilic pore of large conductance and high open probability. Moreover, ATOM channels exhibit a preference for the passage of cationic molecules consistent with the idea that it may translocate unfolded proteins targeted by positively charged N-terminal presequences. This is further supported by the fact that the addition of a presequence peptide induces transient pore closure. An in-depth comparison of these single channel properties with those of other protein translocases reveals that ATOM closely resembles bacterial-type protein export channels rather than eukaryotic Tom40. Our results support the idea that ATOM represents an evolutionary intermediate between a bacterial Omp85-like protein export machinery and the conventional Tom40 that is found in mitochondria of other eukaryotes. PMID:22778261

  12. Bacterial cytokinesis: from Z ring to divisome

    PubMed Central

    Pichoff, Sebastien; Du, Shishen

    2014-01-01

    Ancestral homologues of the major eukaryotic cytoskeletal families, tubulin and actin, play critical roles in cytokinesis of bacterial cells. FtsZ is the ancestral homologue of tubulin and assembles into the Z ring that determines the division plane. FtsA is an ancestral homologue of actin and is involved in coordinating cell wall synthesis during cytokinesis. FtsA assists in the formation of the Z ring and also has a critical role in recruiting downstream division proteins to the Z ring to generate the divisome that divides the cell. Spatial regulation of cytokinesis occurs at the stage of Z ring assembly and regulation of cell size occurs at this stage or during Z ring maturation. PMID:22888013

  13. Bacterial infections other than spontaneous bacterial peritonitis in cirrhosis

    PubMed Central

    Bunchorntavakul, Chalermrat; Chavalitdhamrong, Disaya

    2012-01-01

    Cirrhotic patients are immunocompromised with a high risk of infection. Proinflammatory cytokines and hemodynamic circulation derangement further facilitate the development of serious consequences of infections. Other than spontaneous bacterial peritonitis, bacteremia and bacterial infections of other organ systems are frequently observed. Gram-negative enteric bacteria are the most common causative organism. Other bacterial infections, such as enterococci, Vibrio spp., Aeromonas spp., Clostridium spp., Listeria monocytogenes, Plesiomonas shigelloides and Mycobacterium tuberculosis are more prevalent and more virulent. Generally, intravenous third generation cephalosporins are recommended as empirical antibiotic therapy. Increased incidences of gram-positive and drug-resistant organisms have been reported, particularly in hospital-acquired infections and in patients receiving quinolones prophylaxis. This review focuses upon epidemiology, microbiology, clinical features and treatment of infections in cirrhosis other than spontaneous bacterial peritonitis, including pathogen-specific and liver disease-specific issues. PMID:22662285

  14. Vaccinations against bacterial infections.

    PubMed

    Ocklitz, H W

    1979-01-01

    1. As with any therapeutic measure, prophylactic vaccination is to be jugded by the correlation between benefit and harm or expenditure. By benefit is meant a not to short-lived substantial decrease in the morbidity and/or mortality. Harm refers to the number and severity of side effects in the individual child vaccinated and expenditure means the economic burden placed upon society. 2. The evaluation of many vaccinations at present varies between two extremes: On the one hand vaccination procedures are considered to provide an opportunity to eradicate most of the infectious diseases, on the other hand there is a tendency to assess side effects more drastically the more likely the danger of the particular disease seems eliminated once and for all. 3. An attempt is made to discuss the achieved or achievable standard of vaccination measures against bacterial infections in the light of 3 classes of vaccines. The first class involves well established and commonly used vaccines such as BCG and DPT vaccines although differences in opinion exist on their future employment. 4. The second class involves newer vaccines or vaccines that are under development as for instance vaccines against meningococci, pneumococci, H. influenzae and enteropathogenic E. coli. 5. The third class includes vaccines whose realisation at present appears to be yet difficult or hardly feasible, for instance vaccines against enterotoxins of enteropathogenic organisms, against lues, gonorrhea or for example against organisms of the infectious hospitalism. PMID:388293

  15. Impermanence of bacterial clones

    PubMed Central

    Bobay, Louis-Marie; Traverse, Charles C.; Ochman, Howard

    2015-01-01

    Bacteria reproduce asexually and pass on a single genome copied from the parent, a reproductive mode that assures the clonal descent of progeny; however, a truly clonal bacterial species is extremely rare. The signal of clonality can be interrupted by gene uptake and exchange, initiating homologous recombination that results in the unique sequence of one clone being incorporated into another. Because recombination occurs sporadically and on local scales, these events are often difficult to recognize, even when considering large samples of completely sequenced genomes. Moreover, several processes can produce the appearance of clonality in populations that undergo frequent recombination. The rates and consequences of recombination have been studied in Escherichia coli for over 40 y, and, during this time, there have been several shifting views of its clonal status, population structure, and rates of gene exchange. We reexamine the studies and retrace the evolution of the methods that have assessed the extent of DNA flux, largely focusing on its impact on the E. coli genome. PMID:26195749

  16. The Rare Bacterial Biosphere

    NASA Astrophysics Data System (ADS)

    Pedrós-Alió, Carlos

    2012-01-01

    All communities are dominated by a few species that account for most of the biomass and carbon cycling. On the other hand, a large number of species are represented by only a few individuals. In the case of bacteria, these rare species were until recently invisible. Owing to their low numbers, conventional molecular techniques could not retrieve them. Isolation in pure culture was the only way to identify some of them, but current culturing techniques are unable to isolate most of the bacteria in nature. The recent development of fast and cheap high-throughput sequencing has begun to allow access to the rare species. In the case of bacteria, the exploration of this rare biosphere has several points of interest. First, it will eventually produce a reasonable estimate of the total number of bacterial taxa in the oceans; right now, we do not even know the right order of magnitude. Second, it will answer the question of whether "everything is everywhere." Third, it will require hypothesizing and testing the ecological mechanisms that allow subsistence of many species in low numbers. And fourth, it will open an avenue of research into the immense reserve of genes with potential applications hidden in the rare biosphere.

  17. The bacterial nucleoid revisited.

    PubMed Central

    Robinow, C; Kellenberger, E

    1994-01-01

    This review compares the results of different methods of investigating the morphology of nucleoids of bacteria grown under conditions favoring short generation times. We consider the evidence from fixed and stained specimens, from phase-contrast and fluorescence microscopy of growing bacteria, and from electron microscopy of whole as well as thinly sectioned ones. It is concluded that the nucleoid of growing cells is in a dynamic state: part of the chromatin is "pulled out" of the bulk of the nucleoid in order to be transcribed. This activity is performed by excrescences which extend far into the cytoplasm so as to reach the maximum of available ribosomes. Different means of fixation provide markedly different views of the texture of the DNA-containing plasm of the bulk of the nucleoid. Conventional chemical fixatives stabilize the cytoplasm of bacteria but not their protein-low chromatin. Uranyl acetate does cross-link the latter well but only if the cytoplasm has first been fixed conventionally. In the interval between the two fixations, the DNA arranges itself in liquid-crystalline form, supposedly because of loss of supercoiling. In stark contrast, cryofixation preserves bacterial chromatin in a finely granular form, believed to reflect its native strongly negatively supercoiled state. In dinoflagellates the DNA of their permanently visible chromosomes (also low in histone-like protein) is natively present as a liquid crystal. The arrangement of chromatin in Epulocystis fishelsoni, one of the largest known prokaryotes, is briefly described. Images PMID:7521510

  18. The bacterial 'mitochondrium'.

    PubMed

    Jogler, Christian

    2014-11-01

    Organelles are membrane-enclosed compartments that serve a dedicated physiological purpose. While eukaryotic organelles are common textbook knowledge, bacteria were long thought to lack such subcellular organization. However, Planctomycetes were proposed to comprise a compartmentalized cell plan, including membrane-enclosed organelles such as the paryphoplasm, the pirellulosome, a nucleus-like membrane system and the anammoxosome. The latter is the hallmark of anaerobic ammonium oxidizing (anammox) bacteria, which gain energy by coupling the oxidation of ammonium to the reduction of nitrite. Since calculations indicate that 50% of nitrogen gas in the earth atmosphere results from anammox activity, this process is key for the global nitrogen cycle. Despite strong evidence for a confined compartment housing this reaction, the concept of planctomycetal compartmentalization in general is currently under debate and the presence of organelles in these bacteria was questioned. However, Neumann et?al. (2014) report the isolation of physiological functional anammoxosomes from 'Candidatus?Kuenenia stuttgartiensis'. Subsequent proteomic and microscopic analysis revealed a confined organelle, paralleling eukaryotic mitochondria. This advance is of major importance for the understanding of bacterial compartmentalization in general and of the Planctomycetes in particular. Furthermore, the work of Neumann et?al. leads to a better understanding of the anammox process. PMID:25287615

  19. Bacterial Brain Abscess

    PubMed Central

    Patel, Kevin

    2014-01-01

    Significant advances in the diagnosis and management of bacterial brain abscess over the past several decades have improved the expected outcome of a disease once regarded as invariably fatal. Despite this, intraparenchymal abscess continues to present a serious and potentially life-threatening condition. Brain abscess may result from traumatic brain injury, prior neurosurgical procedure, contiguous spread from a local source, or hematogenous spread of a systemic infection. In a significant proportion of cases, an etiology cannot be identified. Clinical presentation is highly variable and routine laboratory testing lacks sensitivity. As such, a high degree of clinical suspicion is necessary for prompt diagnosis and intervention. Computed tomography and magnetic resonance imaging offer a timely and sensitive method of assessing for abscess. Appearance of abscess on routine imaging lacks specificity and will not spare biopsy in cases where the clinical context does not unequivocally indicate infectious etiology. Current work with advanced imaging modalities may yield more accurate methods of differentiation of mass lesions in the brain. Management of abscess demands a multimodal approach. Surgical intervention and medical therapy are necessary in most cases. Prognosis of brain abscess has improved significantly in the recent decades although close follow-up is required, given the potential for long-term sequelae and a risk of recurrence. PMID:25360205

  20. The rare bacterial biosphere.

    PubMed

    Pedrós-Alió, Carlos

    2012-01-01

    All communities are dominated by a few species that account for most of the biomass and carbon cycling. On the other hand, a large number of species are represented by only a few individuals. In the case of bacteria, these rare species were until recently invisible. Owing to their low numbers, conventional molecular techniques could not retrieve them. Isolation in pure culture was the only way to identify some of them, but current culturing techniques are unable to isolate most of the bacteria in nature. The recent development of fast and cheap high-throughput sequencing has begun to allow access to the rare species. In the case of bacteria, the exploration of this rare biosphere has several points of interest. First, it will eventually produce a reasonable estimate of the total number of bacterial taxa in the oceans; right now, we do not even know the right order of magnitude. Second, it will answer the question of whether "everything is everywhere." Third, it will require hypothesizing and testing the ecological mechanisms that allow subsistence of many species in low numbers. And fourth, it will open an avenue of research into the immense reserve of genes with potential applications hidden in the rare biosphere. PMID:22457983

  1. Bacterial phospholipases C.

    PubMed Central

    Titball, R W

    1993-01-01

    A variety of pathogenic bacteria produce phospholipases C, and since the discovery in 1944 that a bacterial toxin (Clostridium perfringens alpha-toxin) possessed an enzymatic activity, there has been considerable interest in this class of proteins. Initial speculation that all phospholipases C would have lethal properties has not been substantiated. Most of the characterized enzymes fall into one of four groups of structurally related proteins: the zinc-metallophospholipases C, the sphingomyelinases, the phosphatidylinositol-hydrolyzing enzymes, and the pseudomonad phospholipases C. The zinc-metallophospholipases C have been most intensively studied, and lethal toxins within this group possess an additional domain. The toxic phospholipases C can interact with eukaryotic cell membranes and hydrolyze phosphatidylcholine and sphingomyelin, leading to cell lysis. However, measurement of the cytolytic potential or lethality of phospholipases C may not accurately indicate their roles in the pathogenesis of disease. Subcytolytic concentrations of phospholipase C can perturb host cells by activating the arachidonic acid cascade or protein kinase C. Nonlethal phospholipases C, such as the Listeria monocytogenes PLC-A, appear to enhance the release of the organism from the host cell phagosome. Since some phospholipases C play important roles in the pathogenesis of disease, they could form components of vaccines. A greater understanding of the modes of action and structure-function relationships of phospholipases C will facilitate the interpretation of studies in which these enzymes are used as membrane probes and will enhance the use of these proteins as models for eukaryotic phospholipases C. PMID:8336671

  2. Electromagnetism of Bacterial Growth

    NASA Astrophysics Data System (ADS)

    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.

  3. Combatting bacterial persister cells.

    PubMed

    Wood, Thomas K

    2016-03-01

    Most bacterial cells lead lives of quiet desperation in biofilms, combatting stress; yet, their prevalence attests to their ability to alter gene regulation to cope with myriad insults. Since biofilm bacteria are faced with starvation and other environmental stress (e.g., antibiotics from competitors, oxidative stress from host immune systems), it behooves them to be able to ramp down their metabolism in a highly regulated manner and enter a resting state known as persistence to weather stress. Hence, persister cells are metabolically dormant cells that arise predominantly as a response to stress through elegant gene regulation that includes toxin/antitoxin systems. In this review, an analysis is made of the genetic pathways that lead to persistence, of cell signaling via the interspecies and interkingdom signal indole that leads to persistence, and the means found to date for combatting these cells which are frequently tolerant to a range of antibiotics. Biotechnol. Bioeng. 2016;113: 476-483. © 2015 Wiley Periodicals, Inc. PMID:26264116

  4. Evolution of Bacterial Suicide

    NASA Astrophysics Data System (ADS)

    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.

  5. Bacterial and Lyme Arthritis.

    PubMed

    Ross, John J; Hu, Linden T

    2004-10-01

    Septic arthritis is an infectious disease emergency, requiring aggressive joint drainage and prompt antibiotic therapy. Because age and joint damage are major risk factors, septic arthritis may become more common as the baby-boom generation reaches senescence. Bacteremic joint infections have a high mortality, and long-term disability from joint damage is common. Lyme arthritis has a negligible mortality and low morbidity but causes disproportionate popular anxiety. Most patients with Lyme arthritis respond well to oral antibiotic regimens and recover completely. A few patients develop antibiotic-resistant Lyme arthritis, which is probably autoimmune in nature and responds to immunosuppressive therapy. This paper reviews the presentation, diagnosis, and management of bacterial and Lyme arthritis. Septic arthritis caused by Streptococcus pneumoniae and group B streptococci may be increasing in prevalence. Prospective studies are required to determine whether there is any benefit of surgical or arthroscopic joint drainage in septic arthritis, compared with serial arthrocentesis, and to determine the role of corticosteroid therapy in septic arthritis in adults, if any. PMID:15461889

  6. Transport powered by bacterial turbulence.

    PubMed

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S

    2014-04-18

    We demonstrate that collective turbulentlike motion in a bacterial bath can power and steer the directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedgelike "bulldozer" draws energy from a bacterial bath of varied density. We obtain that an optimal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp region of the carrier, which is shielded from the outside turbulent fluctuations. PMID:24785075

  7. Transport Powered by Bacterial Turbulence

    NASA Astrophysics Data System (ADS)

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S.

    2014-04-01

    We demonstrate that collective turbulentlike motion in a bacterial bath can power and steer the directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedgelike "bulldozer" draws energy from a bacterial bath of varied density. We obtain that an optimal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp region of the carrier, which is shielded from the outside turbulent fluctuations.

  8. Canadian guidelines for acute bacterial rhinosinusitis

    PubMed Central

    Kaplan, Alan

    2014-01-01

    Objective To provide a clinical summary of the Canadian clinical practice guidelines for acute bacterial rhinosinusitis (ABRS) that includes relevant considerations for family physicians. Quality of evidence Guideline authors performed a systematic literature search and drafted recommendations. Recommendations received both strength of evidence and strength of recommendation ratings. Input from external content experts was sought, as was endorsement from Canadian medical societies (Association of Medical Microbiology and Infectious Disease Canada, Canadian Society of Allergy and Clinical Immunology, Canadian Society of Otolaryngology—Head and Neck Surgery, Canadian Association of Emergency Physicians, and the Family Physicians Airways Group of Canada). Main message Diagnosis of ABRS is based on the presence of specific symptoms and their duration; imaging or culture are not needed in uncomplicated cases. Treatment is dependent on symptom severity, with intranasal corticosteroids (INCSs) recommended as monotherapy for mild and moderate cases, although the benefit might be modest. Use of INCSs plus antibiotics is reserved for patients who fail to respond to INCSs after 72 hours, and for initial treatment of patients with severe symptoms. Antibiotic selection must account for the suspected pathogen, the risk of resistance, comorbid conditions, and local antimicrobial resistance trends. Adjunct therapies such as nasal saline irrigation are recommended. Failure to respond to treatment, recurrent episodes, and signs of complications should prompt referral to an otolaryngologist. The guidelines address situations unique to the Canadian health care environment, including actions to take during prolonged wait periods for specialist referral or imaging. Conclusion The Canadian guidelines provide up-to-date recommendations for diagnosis and treatment of ABRS that reflect an evolving understanding of the disease. In addition, the guidelines offer useful tools to help clinicians discern viral from bacterial episodes, as well as optimally manage their patients with ABRS. PMID:24627376

  9. Prostatitis- bacterial - self-care

    MedlinePlus

    You have been diagnosed with bacterial prostatitis . This is an infection of the prostate gland. ... If you have acute prostatitis, your symptoms started quickly. You may still feel ill, with fever, chills, and flushing (skin redness). It may hurt a ...

  10. Bacterial pathogen evolution: breaking news.

    PubMed

    Jackson, Robert W; Johnson, Louise J; Clarke, Simon R; Arnold, Dawn L

    2011-01-01

    The immense social and economic impact of bacterial pathogens, from drug-resistant infections in hospitals to the devastation of agricultural resources, has resulted in major investment to understand the causes and consequences of pathogen evolution. Recent genome sequencing projects have provided insight into the evolution of bacterial genome structures; revealing the impact of mobile DNA on genome restructuring and pathogenicity. Sequencing of multiple genomes of related strains has enabled the delineation of pathogen evolution and facilitated the tracking of bacterial pathogens globally. Other recent theoretical and empirical studies have shown that pathogen evolution is significantly influenced by ecological factors, such as the distribution of hosts within the environment and the effects of co-infection. We suggest that the time is ripe for experimentalists to use genomics in conjunction with evolutionary ecology experiments to further understanding of how bacterial pathogens evolve. PMID:21047697

  11. Doug Berndt Evaluated Bacterial Assay

    USGS microbiology technician evaluates a bacterial assay to determine the cause of a wildlife mortality. The USGS National Wildlife Health Center works to identify, track, and prevent wildlife disease....

  12. Bacterial tracheitis in children.

    PubMed Central

    Kasian, G F; Bingham, W T; Steinberg, J; Ninan, A; Sankaran, K; Oman-Ganes, L; Houston, C S

    1989-01-01

    We examined the records of 14 patients aged 7 months to 10 1/4 years who were treated for bacterial tracheitis from May 1982 to December 1987; the management protocol for 13 of the patients included the use of nasotracheal intubation. The infection was caused by Staphylococcus aureus in seven, Haemophilus influenzae in three, Branhamella catarrhalis in one and Streptococcus pneumoniae in one. Both H. influenzae and B. catarrhalis were isolated in another patient, and no organism was found in the remaining patient. In addition to the bacteria, viruses were cultured from the tracheal secretions of two patients. The mean duration of intubation was 7.6 days and of hospital stay 9.2 days. Twelve of the cases occurred during the cold months of the year (October to March). Of the three deaths only one occurred in the pediatric intensive care unit and was due to severe bronchospasm and an air leak that caused bilateral pneumothorax and pneumomediastinum. In one patient subglottic stenosis developed that necessitated tracheostomy. Healing began 5 to 9 days after the onset of symptoms, as demonstrated with the use of repeated fibreoptic bronchoscopy. We found that the airway could be safely managed with the use of a nasotracheal tube. Bronchoscopy helped to confirm the diagnosis, to remove adherent secretions and to monitor the course of the disease. The ventilation tube can be removed after the patient's temperature returns to normal, if there is an air leak around the tube, if the quantity and viscosity of the secretions decrease and if healing is observed at bronchoscopy. PMID:2642395

  13. Bacterial computing with engineered populations.

    PubMed

    Amos, Martyn; Axmann, Ilka Maria; Blüthgen, Nils; de la Cruz, Fernando; Jaramillo, Alfonso; Rodriguez-Paton, Alfonso; Simmel, Friedrich

    2015-07-28

    We describe strategies for the construction of bacterial computing platforms by describing a number of results from the recently completed bacterial computing with engineered populations project. In general, the implementation of such systems requires a framework containing various components such as intracellular circuits, single cell input/output and cell-cell interfacing, as well as extensive analysis. In this overview paper, we describe our approach to each of these, and suggest possible areas for future research. PMID:26078340

  14. Secondary Metabolites Control the Associated Bacterial Communities of Saprophytic Basidiomycotina Fungi

    PubMed Central

    de Carvalho, Maira Peres; Türck, Patrick; Abraham, Wolf-Rainer

    2015-01-01

    Fungi grow under humid conditions and are, therefore, prone to biofilm infections. A 16S rRNA fingerprint analysis was performed on 49 sporocarps of Basidiomycotina in order to determine whether they are able to control these biofilms. Ninety-five bacterial phylotypes, comprising 4 phyla and 10 families, were identified. While ectomycorrhizal fungi harbored the highest bacterial diversity, saprophytic fungi showed little or no association with bacteria. Seven fungal species were screened for antimicrobial and antibiofilm activities. Biofilm formation and bacterial growth was inhibited by extracts obtained from saprophytic fungi, which confirmed the hypothesis that many fungi modulate biofilm colonization on their sporocarps. PMID:25904019

  15. Metagenomic analysis of bacterial and archaeal assemblages in the soil-mousse surrounding a geothermal spring.

    PubMed

    Bhatia, Sonu; Batra, Navneet; Pathak, Ashish; Joshi, Amit; Souza, Leila; Almeida, Paulo; Chauhan, Ashvini

    2015-09-01

    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. PMID:26484255

  16. Reclaiming Family Privilege

    ERIC Educational Resources Information Center

    Seita, John

    2012-01-01

    The pull for family is strong, almost primeval, most likely it is evolutionary, and for those lacking the benefit of family or Family Privilege, the loss of family is painful and profoundly sad. Young people who struggle to cope without stable family connections are profoundly aware of their lack of "Family Privilege." In this article, the author

  17. Reclaiming Family Privilege

    ERIC Educational Resources Information Center

    Seita, John

    2012-01-01

    The pull for family is strong, almost primeval, most likely it is evolutionary, and for those lacking the benefit of family or Family Privilege, the loss of family is painful and profoundly sad. Young people who struggle to cope without stable family connections are profoundly aware of their lack of "Family Privilege." In this article, the author…

  18. Integrating Family Resilience and Family Stress Theory.

    ERIC Educational Resources Information Center

    Patterson, Joan M.

    2002-01-01

    The construct, family resilience, is defined differently by practitioners and researchers. This study tries to clarify the concept of family resilience. The foundation is family stress and coping theory, particularly the stress models that emphasize adaptation processes in families exposed to major adversities. (JDM)

  19. Family Law and Family Studies: Professor's Views

    ERIC Educational Resources Information Center

    Hicks, Mary W.; And Others

    1977-01-01

    The results of a survey of family studies faculty concerning the inclusion of family law topics in family studies courses are discussed. The professor's needs for training and resources in the area of family and the law are identified and recommendations for meeting these needs are suggested. (Author)

  20. 7 CFR 58.135 - Bacterial estimate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Bacterial estimate. 58.135 Section 58.135 Agriculture... Milk § 58.135 Bacterial estimate. (a) Methods of Testing. Milk shall be tested for bacterial estimate... of Testing. A laboratory examination to determine the bacterial estimate shall be made on...

  1. Family Orientation in Family Medicine Training

    PubMed Central

    Talbot, Yves R.; Tannenbaum, David

    1990-01-01

    Teaching about the family has become an important part of the family medicine curriculum. The family orientation index, a 39-item questionnaire, was designed to evaluate the family orientation of services and care provided as well as the teaching and research. The questionnaire was distributed to 55 program directors at 16 Canadian universities. The response rate was 84%. The results indicate that the family orientation of services is less than optimal. PMID:21233938

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

    PubMed

    Krieger, John N; Thumbikat, Praveen

    2016-02-01

    Four prostatitis syndromes are recognized clinically: acute bacterial prostatitis, chronic bacterial prostatitis, chronic prostatitis/chronic pelvic pain syndrome, and asymptomatic prostatitis. Because Escherichia coli represents the most common cause of bacterial prostatitis, we investigated the importance of bacterial virulence factors and antimicrobial resistance in E. coli strains causing prostatitis and the potential association of these characteristics with clinical outcomes. A structured literature review revealed that we have limited understanding of the virulence-associated characteristics of E. coli causing acute prostatitis. Therefore, we completed a comprehensive microbiological and molecular investigation of a unique strain collection isolated from healthy young men. We also considered new data from an animal model system suggesting certain E. coli might prove important in the etiology of chronic prostatitis/chronic pelvic pain syndrome. Our human data suggest that E. coli needs multiple pathogenicity-associated traits to overcome anatomic and immune responses in healthy young men without urological risk factors. The phylogenetic background and accumulation of an exceptional repertoire of extraintestinal pathogenic virulence-associated genes indicate that these E. coli strains belong to a highly virulent subset of uropathogenic variants. In contrast, antibiotic resistance confers little added advantage to E. coli strains in these healthy outpatients. Our animal model data also suggest that certain pathogenic E. coli may be important in the etiology of chronic prostatitis/chronic pelvic pain syndrome through mechanisms that are dependent on the host genetic background and the virulence of the bacterial strain. PMID:26999393

  3. New Functions for the Ancient DedA Membrane Protein Family

    PubMed Central

    Sikdar, Rakesh; Kumar, Sujeet; Boughner, Lisa A.

    2013-01-01

    The DedA protein family is a highly conserved and ancient family of membrane proteins with representatives in most sequenced genomes, including those of bacteria, archaea, and eukarya. The functions of the DedA family proteins remain obscure. However, recent genetic approaches have revealed important roles for certain bacterial DedA family members in membrane homeostasis. Bacterial DedA family mutants display such intriguing phenotypes as cell division defects, temperature sensitivity, altered membrane lipid composition, elevated envelope-related stress responses, and loss of proton motive force. The DedA family is also essential in at least two species of bacteria: Borrelia burgdorferi and Escherichia coli. Here, we describe the phylogenetic distribution of the family and summarize recent progress toward understanding the functions of the DedA membrane protein family. PMID:23086209

  4. Recombinant bacterial amylopullulanases

    PubMed Central

    Nisha, M; Satyanarayana, T

    2013-01-01

    Pullulanases are endo-acting enzymes capable of hydrolyzing α-1, 6-glycosidic linkages in starch, pullulan, amylopectin, and related oligosaccharides, while amylopullulanases are bifunctional enzymes with an active site capable of cleaving both α-1, 4 and α-1, 6 linkages in starch, amylose and other oligosaccharides, and α-1, 6 linkages in pullulan. The amylopullulanases are classified in GH13 and GH57 family enzymes based on the architecture of catalytic domain and number of conserved sequences. The enzymes with two active sites, one for the hydrolysis of α-1, 4- glycosidic bond and the other for α-1, 6-glycosidic bond, are called α-amylase-pullulanases, while amylopullulanases have only one active site for cleaving both α-1, 4- and α-1, 6-glycosidic bonds. The amylopullulanases produced by bacteria find applications in the starch and baking industries as a catalyst for one step starch liquefaction-saccharification for making various sugar syrups, as antistaling agent in bread and as a detergent additive. PMID:23645215

  5. Familial hyperargininaemia.

    PubMed Central

    Terheggen, H G; Lowenthal, A; Lavinha, F; Colombo, J P

    1975-01-01

    A third case of hyperargininaemia occurring in one family was studied from birth. In cord blood serum arginine concentration was only slightly raised, but arginase activity in red blood cell haemolysates was very low. In the urine on day 2 a typical cystinuria pattern was present. Arginine concentration in serum increased to 158 mumol/100 ml on the 41st day of life. Later determinations of the arginase activity in peripheral blood showed values below the sensitivity of the method. Blood ammonia was consistently high, and cystinuria was present. The enzymatic defect was further displayed by intravenous loading tests with arginine. Serum urea values were predominantly normal or near the lower limit of normal, suggesting the presence of other metabolic pathways of urea synthesis. In urine there was no excretion of guanidinosuccinic acid, while the excretion of other monosubstituted guanidine derivatives was increased, pointing to a connexion with hyperargininaemia. Owing to parental attitude, a low protein diet (1-5 g/kg) was introduced only late. The infant developed severe mental retardation, athetosis, and spasticity. PMID:1124944

  6. Gram-Negative Bacterial Sensors for Eukaryotic Signal Molecules

    PubMed Central

    Lesouhaitier, Olivier; Veron, Wilfried; Chapalain, Annelise; Madi, Amar; Blier, Anne-Sophie; Dagorn, Audrey; Connil, Nathalie; Chevalier, Sylvie; Orange, Nicole; Feuilloley, Marc

    2009-01-01

    Ample evidence exists showing that eukaryotic signal molecules synthesized and released by the host can activate the virulence of opportunistic pathogens. The sensitivity of prokaryotes to host signal molecules requires the presence of bacterial sensors. These prokaryotic sensors, or receptors, have a double function: stereospecific recognition in a complex environment and transduction of the message in order to initiate bacterial physiological modifications. As messengers are generally unable to freely cross the bacterial membrane, they require either the presence of sensors anchored in the membrane or transporters allowing direct recognition inside the bacterial cytoplasm. Since the discovery of quorum sensing, it was established that the production of virulence factors by bacteria is tightly growth-phase regulated. It is now obvious that expression of bacterial virulence is also controlled by detection of the eukaryotic messengers released in the micro-environment as endocrine or neuro-endocrine modulators. In the presence of host physiological stress many eukaryotic factors are released and detected by Gram-negative bacteria which in return rapidly adapt their physiology. For instance, Pseudomonas aeruginosa can bind elements of the host immune system such as interferon-γ and dynorphin and then through quorum sensing circuitry enhance its virulence. Escherichia coli sensitivity to the neurohormones of the catecholamines family appears relayed by a recently identified bacterial adrenergic receptor. In the present review, we will describe the mechanisms by which various eukaryotic signal molecules produced by host may activate Gram-negative bacteria virulence. Particular attention will be paid to Pseudomonas, a genus whose representative species, P. aeruginosa, is a common opportunistic pathogen. The discussion will be particularly focused on the pivotal role played by these new types of pathogen sensors from the sensing to the transduction mechanism involved in virulence factors regulation. Finally, we will discuss the consequence of the impact of host signal molecules on commensally or opportunistic pathogens associated with different human tissue. PMID:22399982

  7. Retrocyclins neutralize bacterial toxins by potentiating their unfolding.

    PubMed

    Kudryashova, Elena; Seveau, Stephanie; Lu, Wuyuan; Kudryashov, Dmitri S

    2015-04-15

    Defensins are a class of immune peptides with a broad range of activities against bacterial, fungal and viral pathogens. Besides exerting direct anti-microbial activity via dis-organization of bacterial membranes, defensins are also able to neutralize various unrelated bacterial toxins. Recently, we have demonstrated that in the case of human ?- and ?-defensins, this later ability is achieved through exploiting toxins' marginal thermodynamic stability, i.e. defensins act as molecular anti-chaperones unfolding toxin molecules and exposing their hydrophobic regions and thus promoting toxin precipitation and inactivation [Kudryashova et al. (2014) Immunity 41, 709-721]. Retrocyclins (RCs) are humanized synthetic ?-defensin peptides that possess unique cyclic structure, differentiating them from ?- and ?-defensins. Importantly, RCs are more potent against some bacterial and viral pathogens and more stable than their linear counterparts. However, the mechanism of bacterial toxin inactivation by RCs is not known. In the present study, we demonstrate that RCs facilitate unfolding of bacterial toxins. Using differential scanning fluorimetry (DSF), limited proteolysis and collisional quenching of internal tryptophan fluorescence, we show that hydrophobic regions of toxins normally buried in the molecule interior become more exposed to solvents and accessible to proteolytic cleavage in the presence of RCs. The RC-induced unfolding of toxins led to their precipitation and abrogated activity. Toxin inactivation by RCs was strongly diminished under reducing conditions, but preserved at physiological salt and serum concentrations. Therefore, despite significant structural diversity, ?-, ?- and ?-defensins employ similar mechanisms of toxin inactivation, which may be shared by anti-microbial peptides from other families. PMID:25670244

  8. Taxonomy of bacterial fish pathogens

    PubMed Central

    2011-01-01

    Bacterial taxonomy has progressed from reliance on highly artificial culture-dependent techniques involving the study of phenotype (including morphological, biochemical and physiological data) to the modern applications of molecular biology, most recently 16S rRNA gene sequencing, which gives an insight into evolutionary pathways (= phylogenetics). The latter is applicable to culture-independent approaches, and has led directly to the recognition of new uncultured bacterial groups, i.e. "Candidatus", which have been associated as the cause of some fish diseases, including rainbow trout summer enteritic syndrome. One immediate benefit is that 16S rRNA gene sequencing has led to increased confidence in the accuracy of names allocated to bacterial pathogens. This is in marked contrast to the previous dominance of phenotyping, and identifications, which have been subsequently challenged in the light of 16S rRNA gene sequencing. To date, there has been some fluidity over the names of bacterial fish pathogens, with some, for example Vibrio anguillarum, being divided into two separate entities (V. anguillarum and V. ordalii). Others have been combined, for example V. carchariae, V. harveyi and V. trachuri as V. harveyi. Confusion may result with some organisms recognized by more than one name; V. anguillarum was reclassified as Beneckea and Listonella, with Vibrio and Listonella persisting in the scientific literature. Notwithstanding, modern methods have permitted real progress in the understanding of the taxonomic relationships of many bacterial fish pathogens. PMID:21314902

  9. Bacterial energetics and antimicrobial resistance.

    PubMed

    Proctor, R A; von Humboldt, A

    1998-01-01

    Defining resistance to antimicrobics with specific terms is very useful as the precise mechanisms often lead to better susceptibility testing and improved treatment of bacterial infections. When one can characterize a class of phenotypic resistant organisms as electron transport variants, this has value in that it provides information about the basis for resistance and removes them from the non-specific categorization as phenotypically resistant. Studies of bacterial small colony variants (SCVs) has provided new insights into antimicrobial resistance as well as the connection between expression of virulence factors and energy metabolism. It also provides a framework for further studies which link antibiotic resistance to phase of growth, availability of nutrients, other environmental conditions, and adaptations to stress into a single model wherein the bacterial cell uses the products of energy metabolism to detect its sense of well being and to alter its response to antibiotics (Fig. I). Levels of NADH and ATP are able to act as signaling molecules in both gram positive an gram negative bacteria to activate stress sigma factors and two component systems. In the future, a full understanding of the signaling pathways in bacterial pathogens may provide new targets for the development of drugs to reduce bacterial virulence and to enhance the activity of existing antibiotics. PMID:16904405

  10. Interfering with Bacterial Quorum Sensing

    PubMed Central

    Reuter, Kerstin; Steinbach, Anke; Helms, Volkhard

    2016-01-01

    Quorum sensing (QS) describes the exchange of chemical signals in bacterial populations to adjust the bacterial phenotypes according to the density of bacterial cells. This serves to express phenotypes that are advantageous for the group and ensure bacterial survival. To do so, bacterial cells synthesize autoinducer (AI) molecules, release them to the environment, and take them up. Thereby, the AI concentration reflects the cell density. When the AI concentration exceeds a critical threshold in the cells, the AI may activate the expression of virulence-associated genes or of luminescent proteins. It has been argued that targeting the QS system puts less selective pressure on these pathogens and should avoid the development of resistant bacteria. Therefore, the molecular components of QS systems have been suggested as promising targets for developing new anti-infective compounds. Here, we review the QS systems of selected gram-negative and gram-positive bacteria, namely, Vibrio fischeri, Pseudomonas aeruginosa, and Staphylococcus aureus, and discuss various antivirulence strategies based on blocking different components of the QS machinery. PMID:26819549

  11. Interfering with Bacterial Quorum Sensing.

    PubMed

    Reuter, Kerstin; Steinbach, Anke; Helms, Volkhard

    2016-01-01

    Quorum sensing (QS) describes the exchange of chemical signals in bacterial populations to adjust the bacterial phenotypes according to the density of bacterial cells. This serves to express phenotypes that are advantageous for the group and ensure bacterial survival. To do so, bacterial cells synthesize autoinducer (AI) molecules, release them to the environment, and take them up. Thereby, the AI concentration reflects the cell density. When the AI concentration exceeds a critical threshold in the cells, the AI may activate the expression of virulence-associated genes or of luminescent proteins. It has been argued that targeting the QS system puts less selective pressure on these pathogens and should avoid the development of resistant bacteria. Therefore, the molecular components of QS systems have been suggested as promising targets for developing new anti-infective compounds. Here, we review the QS systems of selected gram-negative and gram-positive bacteria, namely, Vibrio fischeri, Pseudomonas aeruginosa, and Staphylococcus aureus, and discuss various antivirulence strategies based on blocking different components of the QS machinery. PMID:26819549

  12. Pathogenicity Islands in Bacterial Pathogenesis

    PubMed Central

    Schmidt, Herbert; Hensel, Michael

    2004-01-01

    In this review, we focus on a group of mobile genetic elements designated pathogenicity islands (PAI). These elements play a pivotal role in the virulence of bacterial pathogens of humans and are also essential for virulence in pathogens of animals and plants. Characteristic molecular features of PAI of important human pathogens and their role in pathogenesis are described. The availability of a large number of genome sequences of pathogenic bacteria and their benign relatives currently offers a unique opportunity for the identification of novel pathogen-specific genomic islands. However, this knowledge has to be complemented by improved model systems for the analysis of virulence functions of bacterial pathogens. PAI apparently have been acquired during the speciation of pathogens from their nonpathogenic or environmental ancestors. The acquisition of PAI not only is an ancient evolutionary event that led to the appearance of bacterial pathogens on a timescale of millions of years but also may represent a mechanism that contributes to the appearance of new pathogens within a human life span. The acquisition of knowledge about PAI, their structure, their mobility, and the pathogenicity factors they encode not only is helpful in gaining a better understanding of bacterial evolution and interactions of pathogens with eukaryotic host cells but also may have important practical implications such as providing delivery systems for vaccination, tools for cell biology, and tools for the development of new strategies for therapy of bacterial infections. PMID:14726454

  13. Diversity of bacterial communities of fitness center surfaces in a U.S. metropolitan area.

    PubMed

    Mukherjee, Nabanita; Dowd, Scot E; Wise, Andy; Kedia, Sapna; Vohra, Varun; Banerjee, Pratik

    2014-12-01

    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. PMID:25479039

  14. Diversity of Bacterial Communities of Fitness Center Surfaces in a U.S. Metropolitan Area

    PubMed Central

    Mukherjee, Nabanita; Dowd, Scot E.; Wise, Andy; Kedia, Sapna; Vohra, Varun; Banerjee, Pratik

    2014-01-01

    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. PMID:25479039

  15. Bacterial communities in neonatal feces are similar to mothers’ placentae

    PubMed Central

    Dong, Xu-Dong; Li, Xiao-Ran; Luan, Jian-Jun; Liu, Xiao-Feng; Peng, Juan; Luo, Yi-Yong; Liu, Chen-Jian

    2015-01-01

    BACKGROUND: The gut microbiota plays an important role in human health. It is essential to understand how the composition of the gut microbiota in neonates is established. OBJECTIVES: To investigate the nature of the microbial community in the first feces of newborn infants compared with the mothers’ placentae and vaginas. METHODS: One infant who was delivered via Cesarean section was compared with an infant who was delivered vaginally. Bar-coded pyro-sequencing of 16S ribosomal RNA genes was used to investigate the bacterial community composition and structure of each site. RESULTS: Neonatal feces of both infants had similar bacterial communities, and they were similar to the mother’s placenta regardless of the method of delivery. The vaginal bacterial community differed between the two mothers, but not different sites within the vagina. The bacteria in the neonatal feces and the mothers’ placentae demonstrated considerably higher diversity compared with the vaginas. The family Lactobacillaceae dominated in the vaginal samples, while the most abundant family in the fecal and placental samples was Micrococcineae. CONCLUSIONS: These results may provide new directions for the study of infant gut microbial formation. PMID:26015791

  16. Proteolytic inactivation of tissue factor pathway inhibitor by bacterial omptins.

    PubMed

    Yun, Thomas H; Cott, Jessica E; Tapping, Richard I; Slauch, James M; Morrissey, James H

    2009-01-29

    The immune response to infection includes activation of the blood clotting system, leading to extravascular fibrin deposition to limit the spread of invasive microorganisms. Some bacteria have evolved mechanisms to counteract this host response. Pla, a member of the omptin family of Gram-negative bacterial proteases, promotes the invasiveness of the plague bacterium, Yersinia pestis, by activating plasminogen to plasmin to digest fibrin. We now show that the endogenous anticoagulant tissue factor pathway inhibitor (TFPI) is also highly sensitive to proteolysis by Pla and its orthologs OmpT in Escherichia coli and PgtE in Salmonella enterica serovar Typhimurium. Using gene deletions, we demonstrate that bacterial inactivation of TFPI requires omptin expression. TFPI inactivation is mediated by proteolysis since Western blot analysis showed that TFPI cleavage correlated with loss of anticoagulant function in clotting assays. Rates of TFPI inactivation were much higher than rates of plasminogen activation, indicating that TFPI is a better substrate for omptins. We hypothesize that TFPI has evolved sensitivity to proteolytic inactivation by bacterial omptins to potentiate procoagulant responses to bacterial infection. This may contribute to the hemostatic imbalance in disseminated intravascular coagulation and other coagulopathies accompanying severe sepsis. PMID:18988866

  17. Exploring the diversity of protein modifications: special bacterial phosphorylation systems.

    PubMed

    Mijakovic, Ivan; Grangeasse, Christophe; Turgay, Kürşad

    2016-05-01

    Protein modifications not only affect protein homeostasis but can also establish new cellular protein functions and are important components of complex cellular signal sensing and transduction networks. Among these post-translational modifications, protein phosphorylation represents the one that has been most thoroughly investigated. Unlike in eukarya, a large diversity of enzyme families has been shown to phosphorylate and dephosphorylate proteins on various amino acids with different chemical properties in bacteria. In this review, after a brief overview of the known bacterial phosphorylation systems, we focus on more recently discovered and less widely known kinases and phosphatases. Namely, we describe in detail tyrosine- and arginine-phosphorylation together with some examples of unusual serine-phosphorylation systems and discuss their potential role and function in bacterial physiology, and regulatory networks. Investigating these unusual bacterial kinase and phosphatases is not only important to understand their role in bacterial physiology but will help to generally understand the full potential and evolution of protein phosphorylation for signal transduction, protein modification and homeostasis in all cellular life. PMID:26926353

  18. Clinical applications of bacterial glycoproteins.

    PubMed

    Fulton, Kelly M; Smith, Jeffrey C; Twine, Susan M

    2016-04-01

    There is an ongoing race between bacterial evolution and medical advances. Pathogens have the advantages of short generation times and horizontal gene transfer that enable rapid adaptation to new host environments and therapeutics that currently outpaces clinical research. Antibiotic resistance, the growing impact of nosocomial infections, cancer-causing bacteria, the risk of zoonosis, and the possibility of biowarfare all emphasize the increasingly urgent need for medical research focussed on bacterial pathogens. Bacterial glycoproteins are promising targets for alternative therapeutic intervention since they are often surface exposed, involved in host-pathogen interactions, required for virulence, and contain distinctive glycan structures. The potential exists to exploit these unique structures to improve clinical prevention, diagnosis, and treatment strategies. Translation of the potential in this field to actual clinical impact is an exciting prospect for fighting infectious diseases. PMID:26971465

  19. Bacterial metapopulations in nanofabricated landscapes

    PubMed Central

    Keymer, Juan E.; Galajda, Peter; Muldoon, Cecilia; Park, Sungsu; Austin, Robert H.

    2006-01-01

    We have constructed a linear array of coupled, microscale patches of habitat. When bacteria are inoculated into this habitat landscape, a metapopulation emerges. Local bacterial populations in each patch coexist and weakly couple with neighbor populations in nearby patches. These spatially distributed bacterial populations interact through local extinction and colonization processes. We have further built heterogeneous habitat landscapes to study the adaptive dynamics of the bacterial metapopulations. By patterning habitat differences across the landscape, our device physically implements an adaptive landscape. In landscapes with higher niche diversity, we observe rapid adaptation to large-scale, low-quality (high-stress) areas. Our results illustrate the potential lying at the interface between nanoscale biophysics and landscape evolutionary ecology. PMID:17090676

  20. Abdominal radiation causes bacterial translocation

    SciTech Connect

    Guzman-Stein, G.; Bonsack, M.; Liberty, J.; Delaney, J.P.

    1989-02-01

    The purpose of this study was to determine if a single dose of radiation to the rat abdomen leads to bacterial translocation into the mesenteric lymph nodes (MLN). A second issue addressed was whether translocation correlates with anatomic damage to the mucosa. The radiated group (1100 cGy) which received anesthesia also was compared with a control group and a third group which received anesthesia alone but no abdominal radiation. Abdominal radiation lead to 100% positive cultures of MLN between 12 hr and 4 days postradiation. Bacterial translocation was almost nonexistent in the control and anesthesia group. Signs of inflammation and ulceration of the intestinal mucosa were not seen until Day 3 postradiation. Mucosal damage was maximal by Day 4. Bacterial translocation onto the MLN after a single dose of abdominal radiation was not apparently dependent on anatomical, histologic damage of the mucosa.

  1. Bacterial Exotoxins and the Inflammasome

    PubMed Central

    Greaney, Allison J.; Leppla, Stephen H.; Moayeri, Mahtab

    2015-01-01

    The inflammasomes are intracellular protein complexes that play an important role in innate immune sensing. Activation of inflammasomes leads to activation of caspase-1 and maturation and secretion of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18. In certain myeloid cells, this activation can also lead to an inflammatory cell death (pyroptosis). Inflammasome sensor proteins have evolved to detect a range of microbial ligands and bacterial exotoxins either through direct interaction or by detection of host cell changes elicited by these effectors. Bacterial exotoxins activate the inflammasomes through diverse processes, including direct sensor cleavage, modulation of ion fluxes through plasma membrane pore formation, and perturbation of various host cell functions. In this review, we summarize the findings on some of the bacterial exotoxins that activate the inflammasomes. PMID:26617605

  2. Physical stress and bacterial colonization

    PubMed Central

    Otto, Michael

    2014-01-01

    Bacterial surface colonizers are subject to a variety of physical stresses. During the colonization of human epithelia such as on the skin or the intestinal mucosa, bacteria mainly have to withstand the mechanical stress of being removed by fluid flow, scraping, or epithelial turnover. To that end, they express a series of molecules to establish firm attachment to the epithelial surface, such as fibrillar protrusions (pili) and surface-anchored proteins that bind to human matrix proteins. In addition, some bacteria – in particular gut and urinary tract pathogens – use internalization by epithelial cells and other methods such as directed inhibition of epithelial turnover to ascertain continued association with the epithelial layer. Furthermore, many bacteria produce multi-layered agglomerations called biofilms with a sticky extracellular matrix, providing additional protection from removal. This review will give an overview over the mechanisms human bacterial colonizers have to withstand physical stresses with a focus on bacterial adhesion. PMID:25212723

  3. Bacterial toxins: friends or foes?

    PubMed Central

    Schmitt, C. K.; Meysick, K. C.; O'Brien, A. D.

    1999-01-01

    Many emerging and reemerging bacterial pathogens synthesize toxins that serve as primary virulence factors. We highlight seven bacterial toxins produced by well-established or newly emergent pathogenic microbes. These toxins, which affect eukaryotic cells by a variety of means, include Staphylococcus aureus alpha-toxin, Shiga toxin, cytotoxic necrotizing factor type 1, Escherichia coli heat-stable toxin, botulinum and tetanus neurotoxins, and S. aureus toxic-shock syndrome toxin. For each, we discuss the information available on its synthesis and structure, mode of action, and contribution to virulence. We also review the role certain toxins have played in unraveling signal pathways in eukaryotic cells and summarize the beneficial uses of toxins and toxoids. Our intent is to illustrate the importance of the analysis of bacterial toxins to both basic and applied sciences. PMID:10221874

  4. Family Reading Night

    ERIC Educational Resources Information Center

    Hutchins, Darcy; Greenfeld, Marsha; Epstein, Joyce

    2007-01-01

    This book offers clear and practical guidelines to help engage families in student success. It shows families how to conduct a successful Family Reading Night at their school. Family Night themes include Scary Stories, Books We Love, Reading Olympics, Dr. Seuss, and other themes. Family reading nights invite parents to come to school with their…

  5. The Changing Family Structure.

    ERIC Educational Resources Information Center

    Bernard van Leer Foundation Newsletter, 1993

    1993-01-01

    This newsletter issue contains feature articles and short reports on how and why family structures are undergoing substantial change in many parts of the world. These articles include: (1) "The Changing Family Structure," a review of how families are changing and why; (2) "Peru: Families in the Andes"; (3) "Thailand: Families of the Garbage Dump";…

  6. Bacterial diseases in marine bivalves.

    PubMed

    Travers, Marie-Agns; Boettcher Miller, Katherine; Roque, Ana; Friedman, Carolyn S

    2015-10-01

    Bivalve aquaculture is seriously affected by many bacterial pathogens that cause high losses in hatcheries as well as in natural beds. A number of Vibrio species, but also members of the genera Nocardia and Roseovarius, are considered important pathogens in aquaculture. The present work provides an updated overview of main diseases and implicated bacterial species affecting bivalves. This review focuses on aetiological agents, their diversity and virulence factors, the diagnostic methods available as well as information on the dynamics of the host-parasite relationship. PMID:26210496

  7. Extensive Identification of Bacterial Riboflavin Transporters and Their Distribution across Bacterial Species

    PubMed Central

    Merino, Enrique; Bonomi, Hernán Ruy; Goldbaum, Fernando Alberto; García-Angulo, Víctor Antonio

    2015-01-01

    Riboflavin, the precursor for the cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide, is an essential metabolite in all organisms. While the functions for de novo riboflavin biosynthesis and riboflavin import may coexist in bacteria, the extent of this co-occurrence is undetermined. The RibM, RibN, RfuABCD and the energy-coupling factor-RibU bacterial riboflavin transporters have been experimentally characterized. In addition, ImpX, RfnT and RibXY are proposed as riboflavin transporters based on positional clustering with riboflavin biosynthetic pathway (RBP) genes or conservation of the FMN riboswitch regulatory element. Here, we searched for the FMN riboswitch in bacterial genomes to identify genes encoding riboflavin transporters and assessed their distribution among bacteria. Two new putative riboflavin transporters were identified: RibZ in Clostridium and RibV in Mesoplasma florum. Trans-complementation of an Escherichia coli riboflavin auxotroph strain confirmed the riboflavin transport activity of RibZ from Clostridium difficile, RibXY from Chloroflexus aurantiacus, ImpX from Fusobacterium nucleatum and RfnT from Ochrobactrum anthropi. The analysis of the genomic distribution of all known bacterial riboflavin transporters revealed that most occur in species possessing the RBP and that some bacteria may even encode functional riboflavin transporters from two different families. Our results indicate that some species possess ancestral riboflavin transporters, while others possess transporters that appear to have evolved recently. Moreover, our data suggest that unidentified riboflavin transporters also exist. The present study doubles the number of experimentally characterized riboflavin transporters and suggests a specific, non-accessory role for these proteins in riboflavin-prototrophic bacteria. PMID:25938806

  8. Extensive Identification of Bacterial Riboflavin Transporters and Their Distribution across Bacterial Species.

    PubMed

    Gutiérrez-Preciado, Ana; Torres, Alfredo Gabriel; Merino, Enrique; Bonomi, Hernán Ruy; Goldbaum, Fernando Alberto; García-Angulo, Víctor Antonio

    2015-01-01

    Riboflavin, the precursor for the cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide, is an essential metabolite in all organisms. While the functions for de novo riboflavin biosynthesis and riboflavin import may coexist in bacteria, the extent of this co-occurrence is undetermined. The RibM, RibN, RfuABCD and the energy-coupling factor-RibU bacterial riboflavin transporters have been experimentally characterized. In addition, ImpX, RfnT and RibXY are proposed as riboflavin transporters based on positional clustering with riboflavin biosynthetic pathway (RBP) genes or conservation of the FMN riboswitch regulatory element. Here, we searched for the FMN riboswitch in bacterial genomes to identify genes encoding riboflavin transporters and assessed their distribution among bacteria. Two new putative riboflavin transporters were identified: RibZ in Clostridium and RibV in Mesoplasma florum. Trans-complementation of an Escherichia coli riboflavin auxotroph strain confirmed the riboflavin transport activity of RibZ from Clostridium difficile, RibXY from Chloroflexus aurantiacus, ImpX from Fusobacterium nucleatum and RfnT from Ochrobactrum anthropi. The analysis of the genomic distribution of all known bacterial riboflavin transporters revealed that most occur in species possessing the RBP and that some bacteria may even encode functional riboflavin transporters from two different families. Our results indicate that some species possess ancestral riboflavin transporters, while others possess transporters that appear to have evolved recently. Moreover, our data suggest that unidentified riboflavin transporters also exist. The present study doubles the number of experimentally characterized riboflavin transporters and suggests a specific, non-accessory role for these proteins in riboflavin-prototrophic bacteria. PMID:25938806

  9. Revamping Family Preservation Services for Native Families.

    ERIC Educational Resources Information Center

    Coleman, Heather; Unrau, Yvonne A.; Manyfingers, Brenda

    2001-01-01

    Examines the philosophy and program structures of family preservation services (FPS) in the context of providing services to Native American families with child welfare issues. Explores Native cultural concepts of family, child rearing, time, and spirituality. Outlines cross-cultural training needs for FPS workers related to cultural awareness,…

  10. Families in the Military

    MedlinePlus

    ... AACAP Facts for Families Guide Skip breadcrumb navigation Military Families Quick Links Facts For Families Guide Facts ... have led to deployment of large numbers of military personnel (active duty, Reserves, National Guard). As a ...

  11. Family Activities for Fitness

    ERIC Educational Resources Information Center

    Grosse, Susan J.

    2009-01-01

    This article discusses how families can increase family togetherness and improve physical fitness. The author provides easy ways to implement family friendly activities for improving and maintaining physical health. These activities include: walking, backyard games, and fitness challenges.

  12. Family Reunion Health Guide

    MedlinePlus

    ... Phone (Continued) 1. Send a Kidney Health Message Hi Family, I came across this information and thought ... mails to family members. Before the Reunion 1. Hi family! Taking care of your kidneys is important. ...

  13. eCAMBer: efficient support for large-scale comparative analysis of multiple bacterial strains

    PubMed Central

    2014-01-01

    Background Inconsistencies are often observed in the genome annotations of bacterial strains. Moreover, these inconsistencies are often not reflected by sequence discrepancies, but are caused by wrongly annotated gene starts as well as mis-identified gene presence. Thus, tools are needed for improving annotation consistency and accuracy among sets of bacterial strain genomes. Results We have developed eCAMBer, a tool for efficiently supporting comparative analysis of multiple bacterial strains within the same species. eCAMBer is a highly optimized revision of our earlier tool, CAMBer, scaling it up for significantly larger datasets comprising hundreds of bacterial strains. eCAMBer works in two phases. First, it transfers gene annotations among all considered bacterial strains. In this phase, it also identifies homologous gene families and annotation inconsistencies. Second, eCAMBer, tries to improve the quality of annotations by resolving the gene start inconsistencies and filtering out gene families arising from annotation errors propagated in the previous phase. Conculsions eCAMBer efficiently identifies and resolves annotation inconsistencies among closely related bacterial genomes. It outperforms other competing tools both in terms of running time and accuracy of produced annotations. Software, user manual, and case study results are available at the project website: http://bioputer.mimuw.edu.pl/ecamber. PMID:24597904

  14. Bacterial kidney disease (Renibacterium salmoninarum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, is a prevalent disease of salmonid fish that impacts sustainable production for consumption and species conservation efforts. The disease is chronic in nature and mortality most often occurs in juvenile salmonids and prespawning a...

  15. Multiple Forms of Bacterial Hydrogenases

    PubMed Central

    Ackrell, B. A. C.; Asato, R. N.; Mower, H. F.

    1966-01-01

    Ackrell, B. A. C. (University of Hawaii, Honolulu), R. N. Asato, and H. F. Mower. Multiple forms of bacterial hydrogenases. J. Bacteriol. 92:828–838. 1966.—Extracts of certain bacterial species have been shown by disc electrophoresis on polyacrylamide gel to contain multiple hydrogenase systems. The hydrogenase enzymes comprising these systems have different electrophoretic mobilities and produce a band pattern that is unique for each bacterial species. Of 20 bacterial species known to possess hydrogenase activity and which were examined by this technique, only the activities of Clostridium tetanomorphum and C. thermosaccharolyticum could be attributed, at pH 8.3, to a single hydrogenase enzyme. This multiplicity of hydrogenase forms was found both in bacteria which contain mostly soluble hydrogenases and in those where the hydrogenase is predominantly associated with particulate material. When solubilization of this particulate material could be effected, at least two solubilized hydrogenases were released, and, of these, one would have the same electrophoretic properties (i.e., RF) as one of the soluble hydrogenases already present in small amounts within the cell. Different growth conditions for various types of bacteria, such as the nitrogen source, the degree of aeration, and photosynthetic versus aerobic growth in the dark, as well as the conditions under which the cells were stored, markedly affected the hydrogenase activity of the cells, but not their hydrogenase band pattern. The disc electrophoresis technique proved to be 10 times more sensitive than the manometric technique in detecting hydrogenase activity. PMID:5926752

  16. BACTERIAL INHIBITORS IN LAKE WATER

    EPA Science Inventory

    The populations of six bacterial genera fell rapidly after their addition to sterile lake water but not after their addition to buffer. The decline in numbers of two species that were studied further, Klebsiella pneumoniae and Micrococcus flavus, occurred even when the buffer was...

  17. Proteomics of foodborne bacterial pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter focuses on recent research on foodborne bacterial pathogens that use mass spectrometry-based proteomic techniques as well as protein microarrays. Mass spectrometry ionization techniques (e.g. electrospray ionization and matrix-assisted laser desorption/ionization), analyzers (e.g. ion ...

  18. Changing epidemiology of bacterial meningitis.

    PubMed

    Dery, Mark Alain; Hasbun, Rodrigo

    2007-07-01

    Immunization against the most common meningeal pathogens is the leading factor associated with decreased incidence of bacterial meningitis in countries where routine vaccination is available. This is most dramatically illustrated by the reduction in the incidence of Haemophilus influenzae type b meningitis. The incidence of bacterial meningitis has decreased by 55% since the introduction of the H. influenzae type b conjugate vaccine in 1990. H. influenzae occurred primarily in children younger than 5 years of age, and so the median age of patients with bacterial meningitis has now increased to 39 years of age in the United States, and the leading pathogen is currently Streptococcus pneumoniae. Three other control measures (ie, universal screening and antibiotic prophylaxis of pregnant women for Group B streptococci and the implementation and availability of the S. pneumoniae and Neisseria meningitidis conjugate vaccines) have likely further decreased the incidence of these meningeal pathogens. Lastly, the worldwide emergence of multidrug-resistant pneumococci has complicated the empiric therapy of bacterial meningitis. PMID:17618550

  19. Cellular automaton for bacterial towers

    NASA Astrophysics Data System (ADS)

    Indekeu, J. O.; Giuraniuc, C. V.

    2004-05-01

    A simulation approach to the stochastic growth of bacterial towers is presented, in which a non-uniform and finite nutrient supply essentially determines the emerging structure through elementary chemotaxis. The method is based on cellular automata and we use simple, microscopic, local rules for bacterial division in nutrient-rich surroundings. Stochastic nutrient diffusion, while not crucial to the dynamics of the total population, is influential in determining the porosity of the bacterial tower and the roughness of its surface. As the bacteria run out of food, we observe an exponentially rapid saturation to a carrying capacity distribution, similar in many respects to that found in a recently proposed phenomenological hierarchical population model, which uses heuristic parameters and macroscopic rules. Complementary to that phenomenological model, the simulation aims at giving more microscopic insight into the possible mechanisms for one of the recently much studied bacterial morphotypes, known as “towering biofilm”, observed experimentally using confocal laser microscopy. A simulation suggesting a mechanism for biofilm resistance to antibiotics is also shown.

  20. Familial mesothelioma: a report of two families

    SciTech Connect

    Hammar, S.P.; Bockus, D.; Remington, F.; Freidman, S.; LaZerte, G.

    1989-02-01

    Five reports of familial mesothelioma in which mesotheliomas occurred in two or more family members have been recorded in the medical literature. In this report, we describe two examples of familial mesothelioma. In one family, three brothers who worked in the asbestos insulation industry developed mesothelioma. In the second family, the father, who was occupationally exposed to asbestos, died from a tubulopapillary peritoneal mesothelioma 11 years before his son died from an identical histologic type of peritoneal mesothelioma. Our report, as with those previously recorded, suggests that genetic factors may be important in the genesis of some mesotheliomas.

  1. Response to selection for bacterial cold water disease resistance in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A family-based selection program was initiated at the National Center for Cool and Cold Water Aquaculture in 2005 to improve resistance to bacterial cold water disease (BCWD) in rainbow trout. The objective of this study was to estimate response to 2 generations of selection. A total of 14,841 juven...

  2. Mapping of QTL for bacterial cold water disease resistance in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. We previously detected genetic variation in survival following challenge with Flavobacterium psychrophilum, the causative agent of BCWD in rainbow trout, and a family-based selection program to improve res...

  3. Mapping of QTL for bacterial cold water disease resistance in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. We previously detected genetic variation in survival following challenge with Flavobacterium psychrophilum (Fp), the causative agent of BCWD in rainbow trout, and a family-based selection program to improv...

  4. Mapping of QTL for bacterial cold water disease resistance in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonids aquaculture. We previously detected genetic variation in survival following challenge with Flavobacterium psychrophilum (Fp), the causative agent of BCWD in rainbow trout, and a family-based selection program to impro...

  5. Strengthening Family Practices for Latino Families

    PubMed Central

    Chartier, Karen G.; Negroni, Lirio K.; Hesselbrock, Michie N.

    2010-01-01

    The study examined the effectiveness of a culturally-adapted Strengthening Families Program (SFP) for Latinos to reduce risks for alcohol and drug use in children. Latino families, predominantly Puerto Rican, with a 9–12 year old child and a parent(s) with a substance abuse problem participated in the study. Pre- and post-tests were conducted with each family. Parental stress, parent-child dysfunctional relations, and child behavior problems were reduced in the families receiving the intervention; family hardiness and family attachment were improved. Findings contribute to the validation of the SFP with Latinos, and can be used to inform social work practice with Puerto Rican families. PMID:20871785

  6. [GH10 Family of Glycoside Hydrolases: Structure and Evolutionary Connections].

    PubMed

    Naumoff, D G

    2016-01-01

    Evolutionary connections were analyzed for endo-β-xylanases, which possess the GH10 family catalytic domains. A homology search yielded thrice as many proteins as are available from the Carbohydrate-Active Enzymes (CAZy) database. Lateral gene transfer was shown to play an important role in evolution of bacterial proteins of the family, especially in the phyla Acidobacteria, Cyanobacteria, Planctomycetes, Spirochaetes, and Verrucomicrobia. In the case of Verrucomicrobia, 23 lateral transfers from organisms of other phyla were detected. Evolutionary relationships were observed between the GH10 family domains and domains with the TIM-barrel tertiary structure from several other glycosidase families. The GH39 family of glycoside hydrolases showed the closest relationship. Unclassified homologs were grouped into 12 novel families of putative glycoside hydrolases (GHL51-GHL62). PMID:27028821

  7. SIMPLAS: A Simulation of Bacterial Plasmid Maintenance.

    ERIC Educational Resources Information Center

    Dunn, A.; And Others

    1988-01-01

    This article describes a computer simulation of bacterial physiology during growth in a chemostat. The program was designed to help students to appreciate and understand the related effects of parameters which influence plasmid persistence in bacterial populations. (CW)

  8. A Cross-Taxon Analysis of Insect-Associated Bacterial Diversity

    PubMed Central

    Jones, Ryan Thomas; Sanchez, Leticia Gonzales; Fierer, Noah

    2013-01-01

    Although it is well known that plants and animals harbor microbial symbionts that can influence host traits, the factors regulating the structure of these microbial communities often remain largely undetermined. This is particularly true for insect-associated microbial communities, as few cross-taxon comparisons have been conducted to date. To address this knowledge gap and determine how host phylogeny and ecology affect insect-associated microbial communities, we collected 137 insect specimens representing 39 species, 28 families, and 8 orders, and characterized the bacterial communities associated with each specimen via 16S rRNA gene sequencing. Bacterial taxa within the phylum Proteobacteria were dominant in nearly all insects sampled. On average, the insect-associated bacterial communities were not very diverse, with individuals typically harboring fewer than 8 bacterial phylotypes. Bacterial communities also tended to be dominated by a single phylotype; on average, the most abundant phylotype represented 54.7% of community membership. Bacterial communities were significantly more similar among closely related insects than among less-related insects, a pattern driven by within-species community similarity but detected at every level of insect taxonomy tested. Diet was a poor predictor of bacterial community composition. Individual insect species harbored remarkably unique communities: the distribution of 69.0% of bacterial phylotypes was limited to unique insect species, whereas only 5.7% of phylotypes were detected in more than five insect species. Together these results suggest that host characteristics strongly regulate the colonization and assembly of bacterial communities across insect lineages, patterns that are driven either by co-evolution between insects and their symbionts or by closely related insects sharing conserved traits that directly select for similar bacterial communities. PMID:23613815

  9. Bacterial Communities of Diverse Drosophila Species: Ecological Context of a Host–Microbe Model System

    PubMed Central

    Bhatnagar, Srijak; Eisen, Jonathan A.; Kopp, Artyom

    2011-01-01

    Drosophila melanogaster is emerging as an important model of non-pathogenic host–microbe interactions. The genetic and experimental tractability of Drosophila has led to significant gains in our understanding of animal–microbial symbiosis. However, the full implications of these results cannot be appreciated without the knowledge of the microbial communities associated with natural Drosophila populations. In particular, it is not clear whether laboratory cultures can serve as an accurate model of host–microbe interactions that occur in the wild, or those that have occurred over evolutionary time. To fill this gap, we characterized natural bacterial communities associated with 14 species of Drosophila and related genera collected from distant geographic locations. To represent the ecological diversity of Drosophilids, examined species included fruit-, flower-, mushroom-, and cactus-feeders. In parallel, wild host populations were compared to laboratory strains, and controlled experiments were performed to assess the importance of host species and diet in shaping bacterial microbiome composition. We find that Drosophilid flies have taxonomically restricted bacterial communities, with 85% of the natural bacterial microbiome composed of only four bacterial families. The dominant bacterial taxa are widespread and found in many different host species despite the taxonomic, ecological, and geographic diversity of their hosts. Both natural surveys and laboratory experiments indicate that host diet plays a major role in shaping the Drosophila bacterial microbiome. Despite this, the internal bacterial microbiome represents only a highly reduced subset of the external bacterial communities, suggesting that the host exercises some level of control over the bacteria that inhabit its digestive tract. Finally, we show that laboratory strains provide only a limited model of natural host–microbe interactions. Bacterial taxa used in experimental studies are rare or absent in wild Drosophila populations, while the most abundant associates of natural Drosophila populations are rare in the lab. PMID:21966276

  10. Alternative Sigma Factors and Their Roles in Bacterial Virulence

    PubMed Central

    Kazmierczak, Mark J.; Wiedmann, Martin; Boor, Kathryn J.

    2005-01-01

    Sigma factors provide promoter recognition specificity to RNA polymerase holoenzyme, contribute to DNA strand separation, and then dissociate from the core enzyme following transcription initiation. As the regulon of a single sigma factor can be composed of hundreds of genes, sigma factors can provide effective mechanisms for simultaneously regulating expression of large numbers of prokaryotic genes. One newly emerging field is identification of the specific roles of alternative sigma factors in regulating expression of virulence genes and virulence-associated genes in bacterial pathogens. Virulence genes encode proteins whose functions are essential for the bacterium to effectively establish an infection in a host organism. In contrast, virulence-associated genes can contribute to bacterial survival in the environment and therefore may enhance the capacity of the bacterium to spread to new individuals or to survive passage through a host organism. As alternative sigma factors have been shown to regulate expression of both virulence and virulence-associated genes, these proteins can contribute both directly and indirectly to bacterial virulence. Sigma factors are classified into two structurally unrelated families, the σ70 and the σ54 families. The σ70 family includes primary sigma factors (e.g., Bacillus subtilis σA) as well as related alternative sigma factors; σ54 forms a distinct subfamily of sigma factors referred to as σN in almost all species for which these proteins have been characterized to date. We present several examples of alternative sigma factors that have been shown to contribute to virulence in at least one organism. For each sigma factor, when applicable, examples are drawn from multiple species. PMID:16339734

  11. Bacterial endosymbiont infections in 'living fossils': a case study of North American vaejovid scorpions.

    PubMed

    Bryson, Robert W

    2014-07-01

    Bacterial endosymbionts are common among arthropods, and maternally inherited forms can affect the reproductive and behavioural traits of their arthropod hosts. The prevalence of bacterial endosymbionts and their role in scorpion evolution have rarely been investigated. In this study, 61 samples from 40 species of scorpion in the family Vaejovidae were screened for the presence of the bacterial endosymbionts Cardinium, Rickettsia, Spiroplasma and Wolbachia. No samples were infected by these bacteria. However, one primer pair specifically designed to amplify Rickettsia amplified nontarget genes of other taxa. Similar off-target amplification using another endosymbiont-specific primer was also found during preliminary screenings. Results caution against the overreliance on previously published screening primers to detect bacterial endosymbionts in host taxa and suggest that primer specificity may be higher in primers targeting nuclear rather than mitochondrial genes. PMID:24373187

  12. Molecular target of synthetic antimicrobial oligomer in bacterial membranes

    NASA Astrophysics Data System (ADS)

    Yang, Lihua; Gordon, Vernita; Som, Abhigyan; Cronan, John; Tew, Gregory; Wong, Gerard

    2008-03-01

    Antimicrobial peptides comprises a key component of innate immunity for a wide range of multicellular organisms. It has been shown that natural antimicrobial peptides and their synthetic analogs have demonstrated broad-spectrum antimicrobial activity via permeating bacterial membranes selectively. Synthetic antimicrobials with tunable structure and toxicological profiles are ideal for investigations of selectivity mechanisms. We investigate interactions and self-assembly using a prototypical family of antimicrobials based on phenylene ethynylene. Results from synchrotron small angle x-ray scattering (SAXS) results and in vitro microbicidal assays on genetically modified `knock-out' bacteria will be presented.

  13. Molecular Properties of Bacterial Multidrug Transporters

    PubMed Central

    Putman, Monique; van Veen, Hendrik W.; Konings, Wil N.

    2000-01-01

    One of the mechanisms that bacteria utilize to evade the toxic effects of antibiotics is the active extrusion of structurally unrelated drugs from the cell. Both intrinsic and acquired multidrug transporters play an important role in antibiotic resistance of several pathogens, including Neisseria gonorrhoeae, Mycobacterium tuberculosis, Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Vibrio cholerae. Detailed knowledge of the molecular basis of drug recognition and transport by multidrug transport systems is required for the development of new antibiotics that are not extruded or of inhibitors which block the multidrug transporter and allow traditional antibiotics to be effective. This review gives an extensive overview of the currently known multidrug transporters in bacteria. Based on energetics and structural characteristics, the bacterial multidrug transporters can be classified into five distinct families. Functional reconstitution in liposomes of purified multidrug transport proteins from four families revealed that these proteins are capable of mediating the export of structurally unrelated drugs independent of accessory proteins or cytoplasmic components. On the basis of (i) mutations that affect the activity or the substrate specificity of multidrug transporters and (ii) the three-dimensional structure of the drug-binding domain of the regulatory protein BmrR, the substrate-binding site for cationic drugs is predicted to consist of a hydrophobic pocket with a buried negatively charged residue that interacts electrostatically with the positively charged substrate. The aromatic and hydrophobic amino acid residues which form the drug-binding pocket impose restrictions on the shape and size of the substrates. Kinetic analysis of drug transport by multidrug transporters provided evidence that these proteins may contain multiple substrate-binding sites. PMID:11104814

  14. The protective role of endogenous bacterial communities in chironomid egg masses and larvae

    PubMed Central

    Senderovich, Yigal; Halpern, Malka

    2013-01-01

    Insects of the family Chironomidae, also known as chironomids, are distributed worldwide in a variety of water habitats. These insects display a wide range of tolerance toward metals and organic pollutions. Bacterial species known for their ability to degrade toxicants were identified from chironomid egg masses, leading to the hypothesis that bacteria may contribute to the survival of chironomids in polluted environments. To gain a better understanding of the bacterial communities that inhabit chironomids, the endogenous bacteria of egg masses and larvae were studied by 454-pyrosequencing. The microbial community of the egg masses was distinct from that of the larval stage, most likely due to the presence of one dominant bacterial Firmicutes taxon, which consisted of 28% of the total sequence reads from the larvae. This taxon may be an insect symbiont. The bacterial communities of both the egg masses and the larvae were found to include operational taxonomic units, which were closely related to species known as toxicant degraders. Furthermore, various bacterial species with the ability to detoxify metals were isolated from egg masses and larvae. Koch-like postulates were applied to demonstrate that chironomid endogenous bacterial species protect the insect from toxic heavy metals. We conclude that chironomids, which are considered pollution tolerant, are inhabited by stable endogenous bacterial communities that have a role in protecting their hosts from toxicants. This phenomenon, in which bacteria enable the continued existence of their host in hostile environments, may not be restricted only to chironomids. PMID:23804150

  15. Bacterial diversity in the cecum of the world's largest living rodent (Hydrochoerus hydrochaeris).

    PubMed

    García-Amado, M Alexandra; Godoy-Vitorino, Filipa; Piceno, Yvette M; Tom, Lauren M; Andersen, Gary L; Herrera, Emilio A; Domínguez-Bello, Maria G

    2012-05-01

    The capybara (Hydrochoerus hydrochaeris) is the world's largest living rodent. Native to South America, this hindgut fermenter is herbivorous and coprophagous and uses its enlarged cecum to digest dietary plant material. The microbiota of specialized hindgut fermenters has remained largely unexplored. The aim of this work was to describe the composition of the bacterial community in the fermenting cecum of wild capybaras. The analysis of bacterial communities in the capybara cecum is a first step towards the functional characterization of microbial fermentation in this model of hindgut fermentation. We sampled cecal contents from five wild adult capybaras (three males and two females) in the Venezuelan plains. DNA from cecal contents was extracted, the 16S rDNA was amplified, and the amplicons were hybridized onto a DNA microarray (G2 PhyloChip). We found 933 bacterial operational taxonomic units (OTUs) from 182 families in 21 bacterial phyla in the capybara cecum. The core bacterial microbiota (present in at least four animals) was represented by 575 OTUs. About 86% of the cecal bacterial OTUs belong to only five phyla, namely, Firmicutes (322 OTUs), Proteobacteria (301 OTUs), Bacteroidetes (76 OTUs), Actinobacteria (69 OTUs), and Sphirochaetes (37 OTUs). The capybara harbors a diverse bacterial community that includes lineages involved in fiber degradation and nitrogen fixation in other herbivorous animals. PMID:22083250

  16. Distinct antimicrobial peptide expression determines host species-specific bacterial associations.

    PubMed

    Franzenburg, Sören; Walter, Jonas; Künzel, Sven; Wang, Jun; Baines, John F; Bosch, Thomas C G; Fraune, Sebastian

    2013-09-24

    Animals are colonized by coevolved bacterial communities, which contribute to the host's health. This commensal microbiota is often highly specific to its host-species, inferring strong selective pressures on the associated microbes. Several factors, including diet, mucus composition, and the immune system have been proposed as putative determinants of host-associated bacterial communities. Here we report that species-specific antimicrobial peptides account for different bacterial communities associated with closely related species of the cnidarian Hydra. Gene family extensions for potent antimicrobial peptides, the arminins, were detected in four Hydra species, with each species possessing a unique composition and expression profile of arminins. For functional analysis, we inoculated arminin-deficient and control polyps with bacterial consortia characteristic for different Hydra species and compared their selective preferences by 454 pyrosequencing of the bacterial microbiota. In contrast to control polyps, arminin-deficient polyps displayed decreased potential to select for bacterial communities resembling their native microbiota. This finding indicates that species-specific antimicrobial peptides shape species-specific bacterial associations. PMID:24003149

  17. 7 CFR 58.135 - Bacterial estimate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) GRADING AND INSPECTION... Milk § 58.135 Bacterial estimate. (a) Methods of Testing. Milk shall be tested for bacterial estimate... of Testing. A laboratory examination to determine the bacterial estimate shall be made on...

  18. Black Families. Third Edition.

    ERIC Educational Resources Information Center

    McAdoo, Harriette Pipes, Ed.

    The chapters of this collection explore the experiences of black families in the United States and Africa, today and in the past. They are: (1) "African American Families: A Historical Note" (John Hope Franklin); (2) "African American Families and Family Values" (Niara Sudarkasa); (3) "Old-Time Religion: Benches Can't Say 'Amen'" (William Harrison…

  19. THE FAMILY FLAVIVIRIDAE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The family Flaviviridae, commonly referred to as the flavivirus family, contains viruses important to both human and veterinary medicine. The term flavivirus can be confusing because it is used both to refer to the family and one of the three genera within that family. The proper name of the viral...

  20. Family Day Care.

    ERIC Educational Resources Information Center

    Seefeldt, Carol, Ed.; Dittmann, Laura L., Ed.

    This handbook is intended to provide information for the family seeking day care for its children, the family wishing to begin a family day care service, and an agency considering implementing a network of family day care homes. The first section of the handbook is especially intended for parents who are trying to decide which type of day care…

  1. Dual-Income Families.

    ERIC Educational Resources Information Center

    McKitric, Eloise J.

    The impact of economic conditions on two-earner families was examined. Three family types were studied: (1) dual-career family--both the husband and wife are in the labor force but in occupations classified as professional-technical or managerial; (2) dual-earner--both the husband and wife are in the labor force; and (3) traditional family--the…

  2. [Teaching about Family Law].

    ERIC Educational Resources Information Center

    Ryan, John Paul, Ed.

    1992-01-01

    This issue of "Focus on Law Studies""contains a special emphasis on teaching about law and the family", in the form of the following three articles: "Teaching Family Law: Growing Pains and All" (Susan Frelich Appleton); "The Family Goes to Court: Including Law in a Sociological Perspective on the Family" (Mary Ann Lamanna); and Michael Grossberg's

  3. [Teaching about Family Law].

    ERIC Educational Resources Information Center

    Ryan, John Paul, Ed.

    1992-01-01

    This issue of "Focus on Law Studies""contains a special emphasis on teaching about law and the family", in the form of the following three articles: "Teaching Family Law: Growing Pains and All" (Susan Frelich Appleton); "The Family Goes to Court: Including Law in a Sociological Perspective on the Family" (Mary Ann Lamanna); and Michael Grossberg's…

  4. Familial colorectal cancer.

    PubMed

    Lung, M S; Trainer, A H; Campbell, I; Lipton, L

    2015-05-01

    Identifying individuals with a genetic predisposition to developing familial colorectal cancer (CRC) is crucial to the management of the affected individual and their family. In order to do so, the physician requires an understanding of the different gene mutations and clinical manifestations of familial CRC. This review summarises the genetics, clinical manifestations and management of the known familial CRC syndromes, specifically Lynch syndrome, familial adenomatous polyposis, MUTYH-associated neoplasia, juvenile polyposis syndrome and Peutz-Jeghers syndrome. An individual suspected of having a familial CRC with an underlying genetic predisposition should be referred to a familial cancer centre to enable pre-test counselling and appropriate follow up. PMID:25955461

  5. Dynamics of bacterial gene regulation

    NASA Astrophysics Data System (ADS)

    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.

  6. Healthcare-associated bacterial meningitis.

    PubMed

    Laxmi, Sheethal; Tunkel, Allan R

    2011-08-01

    Healthcare-associated bacterial meningitis may occur after neurosurgical procedures, head trauma, and following placement of external or internal ventricular catheters. The likely microorganisms that cause meningitis in this setting (ie, staphylococci and gram-negative bacilli) are different from those that cause meningitis in the community setting. Any clinical suspicion of healthcare-associated bacterial meningitis should prompt a diagnostic evaluation (neuroimaging and cerebrospinal fluid analysis) and appropriate management. Empiric antimicrobial therapy should be directed toward the likely infecting pathogen; based upon clinical response, intraventricular administration of specific agents may be required. With the emergence of resistant gram-negative bacilli (especially Acinetobacter baumannii) that may cause healthcare-associated meningitis, empiric therapy with a carbapenem, with or without an aminoglycoside administered by the intraventricular or intrathecal route, is recommended; colistin (given intravenously and/or intraventricularly) can be used if the organism is subsequently found to be resistant to carbapenems. PMID:21526350

  7. Bacterial streamers in curved microchannels

    NASA Astrophysics Data System (ADS)

    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.

  8. Bacterial Growth on Aminoalkylphosphonic Acids

    PubMed Central

    Harkness, Donald R.

    1966-01-01

    Harkness, Donald R. (University of Miami School of Medicine, Miami, Fla.). Bacterial growth on aminoalkylphosphonic acids. J. Bacteriol. 92:623–627. 1966.—Of 10 bacterial strains tested, 9 were found to be able to utilize the phosphorus of at least one of eight different aminoalkylphosphonic acids for growth, indicating that the ability to catabolize the carbon–phosphorus (C–P) bond is widespread among bacteria. Several organisms gave comparable growth rates as well as cell yields when an equimolar amount of either Pi or 2-aminoethylphosphonic acid (2-AEP) was added to the medium. No compounds containing C–P bonds were detected in Escherichia coli B grown on 2-AEP32-orthophosphate. No degradation of phosphonates by cell-free extracts or suspensions of dried cells was demonstrated. The direct involvement of alkaline phosphatases in cleaving the C–P bond was excluded. PMID:5922537

  9. Antibiotic drugs targeting bacterial RNAs

    PubMed Central

    Hong, Weiling; Zeng, Jie; Xie, Jianping

    2014-01-01

    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. PMID:26579393

  10. Let's stop overlooking bacterial aging.

    PubMed

    Ksi??ek, Krzysztof

    2010-12-01

    It has long been believed that bacteria, the organisms displaying symmetrical pattern of divisions, cannot age, and thereby constitute essentially immortal creatures. In recent years, the discovery of morphologically (Caulobacter crescentus) and functionally (Escherichia coli) asymmetrical cell fission as well as an observation of cell behavior in the stationary growth phase (Escherichia coli) overthrew, at least partly, the myth of bacterial immortality. In fact, the body of evidence has accumulated that bacteria may also get old similarly as eukaryotic cells and organisms do. In this paper a brief overview of the state-of-art in the field of bacterial aging is discussed, and the major challenges and limitations in these research are delineated. PMID:20440559

  11. Collective Functionality through Bacterial Individuality

    NASA Astrophysics Data System (ADS)

    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.

  12. Bacterial cheating limits antibiotic resistance

    NASA Astrophysics Data System (ADS)

    Xiao Chao, Hui; Yurtsev, Eugene; Datta, Manoshi; Artemova, Tanya; Gore, Jeff

    2012-02-01

    The widespread use of antibiotics has led to the evolution of resistance in bacteria. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removing the antibiotic. The cooperative nature of this growth suggests that a cheater strain---which does not contribute to breaking down the antibiotic---may be able to take advantage of cells cooperatively inactivating the antibiotic. Here we find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We observe stable coexistence between the two strains and find that a simple model successfully explains the behavior as a function of antibiotic concentration and cell density. We anticipate that our results will provide insight into the evolutionary origin of phenotypic diversity and cooperative behaviors.

  13. Genetic control of bacterial biofilms.

    PubMed

    Wolska, Krystyna I; Grudniak, Anna M; Rudnicka, Zofia; Markowska, Katarzyna

    2016-05-01

    Nearly all bacterial species, including pathogens, have the ability to form biofilms. Biofilms are defined as structured ecosystems in which microbes are attached to surfaces and embedded in a matrix composed of polysaccharides, eDNA, and proteins, and their development is a multistep process. Bacterial biofilms constitute a large medical problem due to their extremely high resistance to various types of therapeutics, including conventional antibiotics. Several environmental and genetic signals control every step of biofilm development and dispersal. From among the latter, quorum sensing, cyclic diguanosine-5'-monophosphate, and small RNAs are considered as the main regulators. The present review describes the control role of these three regulators in the life cycles of biofilms built by Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella enterica serovar Typhimurium, and Vibrio cholerae. The interconnections between their activities are shown. Compounds and strategies which target the activity of these regulators, mainly quorum sensing inhibitors, and their potential role in therapy are also assessed. PMID:26294280

  14. Intercellular nanotubes mediate bacterial communication.

    PubMed

    Dubey, Gyanendra P; Ben-Yehuda, Sigal

    2011-02-18

    Bacteria are known to communicate primarily via secreted extracellular factors. Here we identify a previously uncharacterized type of bacterial communication mediated by nanotubes that bridge neighboring cells. Using Bacillus subtilis as a model organism, we visualized transfer of cytoplasmic fluorescent molecules between adjacent cells. Additionally, by coculturing strains harboring different antibiotic resistance genes, we demonstrated that molecular exchange enables cells to transiently acquire nonhereditary resistance. Furthermore, nonconjugative plasmids could be transferred from one cell to another, thereby conferring hereditary features to recipient cells. Electron microscopy revealed the existence of variously sized tubular extensions bridging neighboring cells, serving as a route for exchange of intracellular molecules. These nanotubes also formed in an interspecies manner, between B. subtilis and Staphylococcus aureus, and even between B. subtilis and the evolutionary distant bacterium Escherichia coli. We propose that nanotubes represent a major form of bacterial communication in nature, providing a network for exchange of cellular molecules within and between species. PMID:21335240

  15. Functional Taxonomy of Bacterial Hyperstructures

    PubMed Central

    Norris, Vic; den Blaauwen, Tanneke; Cabin-Flaman, Armelle; Doi, Roy H.; Harshey, Rasika; Janniere, Laurent; Jimenez-Sanchez, Alfonso; Jin, Ding Jun; Levin, Petra Anne; Mileykovskaya, Eugenia; Minsky, Abraham; Saier, Milton; Skarstad, Kirsten

    2007-01-01

    The levels of organization that exist in bacteria extend from macromolecules to populations. Evidence that there is also a level of organization intermediate between the macromolecule and the bacterial cell is accumulating. This is the level of hyperstructures. Here, we review a variety of spatially extended structures, complexes, and assemblies that might be termed hyperstructures. These include ribosomal or “nucleolar” hyperstructures; transertion hyperstructures; putative phosphotransferase system and glycolytic hyperstructures; chemosignaling and flagellar hyperstructures; DNA repair hyperstructures; cytoskeletal hyperstructures based on EF-Tu, FtsZ, and MreB; and cell cycle hyperstructures responsible for DNA replication, sequestration of newly replicated origins, segregation, compaction, and division. We propose principles for classifying these hyperstructures and finally illustrate how thinking in terms of hyperstructures may lead to a different vision of the bacterial cell. PMID:17347523

  16. Bacterial diversity in three distinct sub-habitats within the pitchers of the northern pitcher plant, Sarracenia purpurea.

    PubMed

    Krieger, Joseph R; Kourtev, Peter S

    2012-03-01

    Pitcher plants have been widely used in ecological studies of food webs; however, their bacterial communities are poorly characterized. Pitchers of Sarracenia purpurea contain several distinct sub-habitats, namely the bottom sediment, the liquid, and the internal pitcher wall. We hypothesized that those three sub-habitats within pitcher plants are inhabited by distinct bacterial populations. We used denaturing gradient gel electrophoresis and 16S rRNA gene sequencing to characterize bacterial populations in pitchers from three bogs. DGGE and sequencing revealed that in any given pitcher, the three sub-habitats contain significantly different bacterial populations. However, there was significant variability between bacterial populations inhabiting the same type of habitat in different pitchers, even at the same site. Therefore, no consistent set of bacterial populations was enriched in any of the three sub-habitats. All sub-habitats appeared to be dominated by alpha- and betaproteobacteria in differing proportions. In addition, sequences from the Bacteroidetes and Firmicutes were obtained from all three sub-habitats. We conclude that container aquatic habitats such as the pitchers of S. purpurea possess a very high bacterial diversity, with many unique bacterial populations enriched in individual pitchers. Within an individual pitcher, populations of certain bacterial families may be enriched in one of the three studied sub-habitats. PMID:22092381

  17. Host defenses and bacterial resistance.

    PubMed

    Yancey, M K

    1992-09-01

    The amount of knowledge and understanding about the human immune system has expanded rapidly in the past several decades. The ability of the physician to care for pregnant women, specifically those with infectious diseases, can be enhanced through a basic understanding of host defenses and the normal alterations of these defenses encountered during pregnancy. A general understanding of bacterial resistance to antimicrobial agents will also aid the practitioner in selecting the appropriate setting and agent when prescribing these drugs. PMID:1436921

  18. Identification of bacterial guanylate cyclases.

    PubMed

    Ryu, Min-Hyung; Youn, Hwan; Kang, In-Hye; Gomelsky, Mark

    2015-05-01

    The ability of bacteria to use cGMP as a second messenger has been controversial for decades. Recently, nucleotide cyclases from Rhodospirillum centenum, GcyA, and Xanthomonas campestris, GuaX, have been shown to possess guanylate cyclase activities. Enzymatic activities of these guanylate cyclases measured in vitro were low, which makes interpretation of the assays ambiguous. Protein sequence analysis at present is insufficient to distinguish between bacterial adenylate and guanylate cyclases, both of which belong to nucleotide cyclases of type III. We developed a simple method for discriminating between guanylate and adenylate cyclase activities in a physiologically relevant bacterial system. The method relies on the use of a mutant cAMP receptor protein, CRPG , constructed here. While wild-type CRP is activated exclusively by cAMP, CRPG can be activated by either cAMP or cGMP. Using CRP- and CRPG -dependent lacZ expression in two E. coli strains, we verified that R. centenum GcyA and X. campestris GuaX have primarily guanylate cyclase activities. Among two other bacterial nucleotide cyclases tested, one, GuaA from Azospillrillum sp. B510, proved to have guanylate cyclase activity, while the other one, Bradyrhizobium japonicum CyaA, turned out to function as an adenylate cyclase. The results obtained with this reporter system were in excellent agreement with direct measurements of cyclic nucleotides secreted by E. coli expressing nucleotide cyclase genes. The simple genetic screen developed here is expected to facilitate identification of bacterial guanylate cyclases and engineering of guanylate cyclases with desired properties. PMID:25645367

  19. Bacterial infections: antibiotics and decontamination.

    PubMed

    Gould, Dinah

    Infectious disease is caused by bacteria, viruses, fungi, protozoa and micro-organisms including the mycoplasmas, rickettsiae and chlamydiae. Most of the infections commonly encountered in the UK are caused either by bacteria or viruses. This article describes bacterial structure and function to explain how antibiotics work and the processes of decontamination such as cleaning, disinfection and sterilisation, which are important in infection control. PMID:15224613

  20. Identification of polyamine-responsive bacterioplankton taxa in South Atlantic Bight.

    PubMed

    Lu, Xinxin; Sun, Shulei; Hollibaugh, James T; Mou, Xiaozhen

    2015-12-01

    Putrescine and spermidine are short-chained aliphatic polyamines (PAs) that are ubiquitously distributed in seawater. These compounds may be important sources of dissolved organic carbon and nitrogen for marine bacterioplankton. Here, we used pyrotag sequencing to quantify the response of bacterioplankton to putrescine and spermidine amendments in microcosms established using surface waters collected at various stations in the South Atlantic Bight in October 2011. Our analysis showed that PA-responsive bacterioplankton consisted of bacterial taxa that are typically dominant in marine systems. Rhodobacteraceae (Alphaproteobacteria) was the taxon most responsive to PA additions at the nearshore site. Gammaproteobacteria of the families Piscirickettsiaceae; Vibrionaceae; and Vibrionaceae and Pseudoalteromonadaceae, were the dominant PA-responsive taxa in samples from the river-influenced coastal station, offshore station and open ocean station, respectively. The spatial variability of PA-responsive taxa may be attributed to differences in composition of the initial bacterial community and variations of in situ physiochemical conditions among sites. Our results also provided the first empirical evidence that Gammaproteobacteria might play an important role in PA transformation in marine systems. PMID:26109269

  1. Bacterial glycosidases for the production of universal red blood cells.

    PubMed

    Liu, Qiyong P; Sulzenbacher, Gerlind; Yuan, Huaiping; Bennett, Eric P; Pietz, Greg; Saunders, Kristen; Spence, Jean; Nudelman, Edward; Levery, Steven B; White, Thayer; Neveu, John M; Lane, William S; Bourne, Yves; Olsson, Martin L; Henrissat, Bernard; Clausen, Henrik

    2007-04-01

    Enzymatic removal of blood group ABO antigens to develop universal red blood cells (RBCs) was a pioneering vision originally proposed more than 25 years ago. Although the feasibility of this approach was demonstrated in clinical trials for group B RBCs, a major obstacle in translating this technology to clinical practice has been the lack of efficient glycosidase enzymes. Here we report two bacterial glycosidase gene families that provide enzymes capable of efficient removal of A and B antigens at neutral pH with low consumption of recombinant enzymes. The crystal structure of a member of the alpha-N-acetylgalactosaminidase family reveals an unusual catalytic mechanism involving NAD+. The enzymatic conversion processes we describe hold promise for achieving the goal of producing universal RBCs, which would improve the blood supply while enhancing the safety of clinical transfusions. PMID:17401360

  2. Bacterial motion in narrow capillaries

    PubMed Central

    Ping, Liyan; Wasnik, Vaibhav; Emberly, Eldon

    2014-01-01

    Motile bacteria often have to pass through small tortuous pores in soil or tissue of higher organisms. However, their motion in this prevalent type of niche is not fully understood. Here, we modeled it with narrow glass capillaries and identified a critical radius (Rc) for bacterial motion. Near the surface of capillaries narrower than that, the swimming trajectories are helices. In larger capillaries, they swim in distorted circles. Under non-slip condition, the peritrichous Escherichia coli swam in left-handed helices with an Rc of ∼10 μm near glass surface. However, slipping could occur in the fast monotrichous Pseudomonas fluorescens, when a speed threshold was exceeded, and thus both left-handed and right-handed helices were executed in glass capillaries. In the natural non-cylindrical pores, the near-surface trajectories would be spirals and twisted loops. Engaging in such motions reduces the bacterial migration rate. With a given pore size, the run length and the tumbling angle of the bacterium determine the probability and duration of their near-surface motion. Shear flow and chemotaxis potentially enhance it. Based on this observation, the puzzling previous observations on bacterial migration in porous environments can be interpreted. PMID:25764548

  3. Bacterial translocation in experimental uremia.

    PubMed

    de Almeida Duarte, Joãn Bosco; de Aguilar-Nascimento, José Eduardo; Nascimento, Mariana; Nochi, Rubens Jardim

    2004-08-01

    The aim of this study was to investigate whether or not experimental uremia would induce bacterial translocation. Forty male Wistar rats were randomized into two groups: uremic (n = 20) and control (n = 20). Under anesthesia, the upper and lower left renal poles and the marginal lateral parenchyma were excised in uremic group. Seven days later, in a second operation, the liver, spleen and the mesenteric lymph nodes (MLN) were excised and cultured. Blood samples were sent for biochemical analysis (BUN, creatinine, sodium and potassium) and cultured. Specimens of the jejunum (1 cm below the Treitz angle) and ileum (1 cm above the ileocecal valve) were collected and sent for histological examination and scored for the degree of inflammation of the mucosa using a classification proposed by Chiu et al. in 1970. Uremic rats presented higher BUN, creatinine and potassium than controls. Bacterial translocation was more frequent in uremic than in control animals (8/20 (40%) vs. 1/20 (5%); p = 0.02). Translocation in uremic rats was observed mainly at the MLN (all eight cases). Both at the jejunum (uremic = 3 [0-5] vs. control = 2 [0-4]; p = 0.04) and the ileum (uremic - 2 [0-5] vs. control = 0 [0-3]; p = 0.01), inflammation score was higher in uremic rats than in controls. The intestinal mucosa barrier is impaired and bacterial translocation occurs in experimental uremia. PMID:15497213

  4. Detergent-compatible bacterial amylases.

    PubMed

    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. PMID:25129040

  5. Bacterial infections complicating tongue piercing

    PubMed Central

    Yu, Catherine HY; Minnema, Brian J; Gold, Wayne L

    2010-01-01

    Tongue piercing has become an increasingly popular form of body art. However, this procedure can occasionally be complicated by serious bacterial infections. The present article reports a case of prosthetic valve endocarditis caused by a Gemella species in a patient with a pierced tongue, and reviews 18 additional cases of local and systemic bacterial infections associated with tongue piercing. Infections localized to the oral cavity and head and neck region included molar abscess, glossal abscess, glossitis, submandibular lymphadenitis, submandibular sialadenitis, Ludwig’s angina and cephalic tetanus. Infections distal to the piercing site included eight cases of infective endocarditis, one case of chorioamnionitis and one case of cerebellar abscess. Oropharyngeal flora were isolated from all cases. While bacterial infections following tongue piercing are rare, there are reports of potentially life-threatening infections associated with the procedure. Both piercers and their clients should be aware of these potential complications, and standardized infection prevention and control practices should be adopted by piercers to reduce the risk. PMID:21358880

  6. Bacterial sex in dental plaque

    PubMed Central

    Olsen, Ingar; Tribble, Gena D.; Fiehn, Nils-Erik; Wang, Bing-Yan

    2013-01-01

    Genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. Membrane vesicles can also provide a mechanism for horizontal gene transfer. DNA transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. Several examples of bacterial gene transfer in the oral cavity are given in this review. How frequently this occurs in dental plaque is not clear, but evidence suggests that it affects a number of the major genera present. It has been estimated that new sequences in genomes established through horizontal gene transfer can constitute up to 30% of bacterial genomes. Gene transfer can be both inter- and intrageneric, and it can also affect transient organisms. The transferred DNA can be integrated or recombined in the recipient's chromosome or remain as an extrachromosomal inheritable element. This can make dental plaque a reservoir for antimicrobial resistance genes. The ability to transfer DNA is important for bacteria, making them better adapted to the harsh environment of the human mouth, and promoting their survival, virulence, and pathogenicity. PMID:23741559

  7. Sulfate decomposition by bacterial leaching

    SciTech Connect

    Deveci, N.; Delaloglu, C.G.

    1995-04-01

    Sulfate disposal is the main problem of many industrial effluents, such as excess sulfuric acid, gypsum, coal desulfurization byproducts, acid-mine waters, and general metallurgical effluents. It has been established that sulfate present in wastes can be converted to elemental sulfur by bacterial mutualism. This study presents the results of an investigation of the industrial feasibility of utilizing a biological system capable of converting hydrous calcium sulfate (gypsum) to elemental sulfur. Gypsum, which was used in this study, is a byproduct of the fertilizer industry. The biological system is referred to as a bacterial mutualism, and involves Desulfovibrio desulfuricans for sulfate conversion and Chlorobium thiosulfatophilum for hydrogen sulfide conversion. Bacterial mutualism and utilization of sulfate were investigated by means of a two-stage anaerobic system. In the first stage, a gas purge system was used for sulfate conversion to sulfide, and it was found that maximum conversion is 34%. In the second stage, a static culture system was used for sulfide conversion to sulfur with a conversion of 92%. 14 refs., 5 tabs.

  8. Bacterial strategies for chemotaxis response.

    PubMed

    Celani, Antonio; Vergassola, Massimo

    2010-01-26

    Regular environmental conditions allow for the evolution of specifically adapted responses, whereas complex environments usually lead to conflicting requirements upon the organism's response. A relevant instance of these issues is bacterial chemotaxis, where the evolutionary and functional reasons for the experimentally observed response to chemoattractants remain a riddle. Sensing and motility requirements are in fact optimized by different responses, which strongly depend on the chemoattractant environmental profiles. It is not clear then how those conflicting requirements quantitatively combine and compromise in shaping the chemotaxis response. Here we show that the experimental bacterial response corresponds to the maximin strategy that ensures the highest minimum uptake of chemoattractants for any profile of concentration. We show that the maximin response is the unique one that always outcompetes motile but nonchemotactic bacteria. The maximin strategy is adapted to the variable environments experienced by bacteria, and we explicitly show its emergence in simulations of bacterial populations in a chemostat. Finally, we recast the contrast of evolution in regular vs. complex environments in terms of minimax vs. maximin game-theoretical strategies. Our results are generally relevant to biological optimization principles and provide a systematic possibility to get around the need to know precisely the statistics of environmental fluctuations. PMID:20080704

  9. Dialkylresorcinols as bacterial signaling molecules

    PubMed Central

    Brameyer, Sophie; Kresovic, Darko; Bode, Helge B.; Heermann, Ralf

    2015-01-01

    It is well recognized that bacteria communicate via small diffusible molecules, a process termed quorum sensing. The best understood quorum sensing systems are those that use acylated homoserine lactones (AHLs) for communication. The prototype of those systems consists of a LuxI-like AHL synthase and a cognate LuxR receptor that detects the signal. However, many proteobacteria possess LuxR receptors, yet lack any LuxI-type synthase, and thus these receptors are referred to as LuxR orphans or solos. In addition to the well-known AHLs, little is known about the signaling molecules that are sensed by LuxR solos. Here, we describe a novel cell–cell communication system in the insect and human pathogen Photorhabdus asymbiotica. We identified the LuxR homolog PauR to sense dialkylresorcinols (DARs) and cyclohexanediones (CHDs) instead of AHLs as signals. The DarABC synthesis pathway produces the molecules, and the entire system emerged as important for virulence. Moreover, we have analyzed more than 90 different Photorhabdus strains by HPLC/MS and showed that these DARs and CHDs are specific to the human pathogen P. asymbiotica. On the basis of genomic evidence, 116 other bacterial species are putative DAR producers, among them many human pathogens. Therefore, we discuss the possibility of DARs as novel and widespread bacterial signaling molecules and show that bacterial cell–cell communication goes far beyond AHL signaling in nature. PMID:25550519

  10. Phylogenetic mapping of bacterial morphology

    NASA Technical Reports Server (NTRS)

    Siefert, J. L.; Fox, G. E.

    1998-01-01

    The availability of a meaningful molecular phylogeny for bacteria provides a context for examining the historical significance of various developments in bacterial evolution. Herein, the classical morphological descriptions of selected members of the domain Bacteria are mapped upon the genealogical ancestry deduced from comparison of small-subunit rRNA sequences. For the species examined in this study, a distinct pattern emerges which indicates that the coccus shape has arisen and accumulated independently multiple times in separate lineages and typically survived as a persistent end-state morphology. At least two other morphologies persist but have evolved only once. This study demonstrates that although bacterial morphology is not useful in defining bacterial phylogeny, it is remarkably consistent with that phylogeny once it is known. An examination of the experimental evidence available for morphogenesis as well as microbial fossil evidence corroborates these findings. It is proposed that the accumulation of persistent morphologies is a result of the biophysical properties of peptidoglycan and their genetic control, and that an evolved body-plan strategy based on peptidoglycan may have been a fate-sealing step in the evolution of Bacteria. More generally, this study illustrates that significant evolutionary insights can be obtained by examining biological and biochemical data in the context of a reliable phylogenetic structure.

  11. YidC/Alb3/Oxa1 Family of Insertases.

    PubMed

    Hennon, Seth W; Soman, Raunak; Zhu, Lu; Dalbey, Ross E

    2015-06-12

    The YidC/Alb3/Oxa1 family functions in the insertion and folding of proteins in the bacterial cytoplasmic membrane, the chloroplast thylakoid membrane, and the mitochondrial inner membrane. All members share a conserved region composed of five transmembrane regions. These proteins mediate membrane insertion of an assorted group of proteins, ranging from respiratory subunits in the mitochondria and light-harvesting chlorophyll-binding proteins in chloroplasts to ATP synthase subunits in bacteria. This review discusses the YidC/Alb3/Oxa1 protein family as well as their function in membrane insertion and two new structures of the bacterial YidC, which suggest a mechanism for membrane insertion by this family of insertases. PMID:25947384

  12. Surface micropattern limits bacterial contamination

    PubMed Central

    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 additives. The studies presented here were carried out to investigate the MP surfaces capability to reduce colonization of methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) compared to smooth control surfaces. Methods The MP and smooth surfaces produced in acrylic film were compared for remaining bacterial contamination and colonization following inoculation. Direct sampling of surfaces was carried out after inoculation by immersion, spray, and/or touch methods. Ultimately, a combination assay was developed to assess bacterial contamination after touch transfer inoculation combined with drying (persistence) to mimic common environmental contamination scenarios in the clinic or hospital environment. The combination transfer and persistence assay was then used to test antimicrobial copper beside the MP for the ability to reduce MSSA and MRSA challenge. Results The MP reduced bacterial contamination with log reductions ranging from 87-99% (LR = 0.90-2.18; p < 0.05) compared to smooth control surfaces. The MP was more effective than the 99.9% pure copper alloy C11000 at reducing surface contamination of S. aureus (MSSA and MRSA) through transfer and persistence of bacteria. The MP reduced MSSA by as much as 97% (LR = 1.54; p < 0.01) and MRSA by as much as 94% (LR = 1.26; p < 0.005) compared to smooth controls. Antimicrobial copper had no significant effect on MSSA contamination, but reduced MRSA contamination by 80% (LR = 0.70; p < 0.005). Conclusion The assays developed in this study mimic hospital environmental contamination events to demonstrate the performance of a MP to limit contamination under multiple conditions. Antimicrobial copper has been implemented in hospital room studies to evaluate its impact on nosocomial infections and a decrease in HAI rate was shown. Similar implementation of the MP has potential to reduce the incidence of HAIs although future clinical studies will be necessary to validate the MP’s true impact. PMID:25232470

  13. Relationships between Host Phylogeny, Host Type and Bacterial Community Diversity in Cold-Water Coral Reef Sponges

    PubMed Central

    Schttner, Sandra; Hoffmann, Friederike; Crdenas, Paco; Rapp, Hans Tore; Boetius, Antje; Ramette, Alban

    2013-01-01

    Cold-water coral reefs are known to locally enhance the diversity of deep-sea fauna as well as of microbes. Sponges are among the most diverse faunal groups in these ecosystems, and many of them host large abundances of microbes in their tissues. In this study, twelve sponge species from three cold-water coral reefs off Norway were investigated for the relationship between sponge phylogenetic classification (species and family level), as well as sponge type (high versus low microbial abundance), and the diversity of sponge-associated bacterial communities, taking also geographic location and water depth into account. Community analysis by Automated Ribosomal Intergenic Spacer Analysis (ARISA) showed that as many as 345 (79%) of the 437 different bacterial operational taxonomic units (OTUs) detected in the dataset were shared between sponges and sediments, while only 70 (16%) appeared purely sponge-associated. Furthermore, changes in bacterial community structure were significantly related to sponge species (63% of explained community variation), sponge family (52%) or sponge type (30%), whereas mesoscale geographic distances and water depth showed comparatively small effects (<5% each). In addition, a highly significant, positive relationship between bacterial community dissimilarity and sponge phylogenetic distance was observed within the ancient family of the Geodiidae. Overall, the high diversity of sponges in cold-water coral reefs, combined with the observed sponge-related variation in bacterial community structure, support the idea that sponges represent heterogeneous, yet structured microbial habitats that contribute significantly to enhancing bacterial diversity in deep-sea ecosystems. PMID:23393586

  14. AIDS and the family: families take care.

    PubMed

    1994-01-01

    In 1994, the International Year of the Family, the WHO's Global Program on AIDS (GPA) is marking World AIDS Day under the banner AIDS and the Family. Traditional and non-traditional families have a crucial role to play in addressing the HIV/AIDS pandemic. In the run-up to World AIDS Day--and on 1 December itself--GPA urges the world to focus on how families of all kinds are affected by AIDS, on how they can be more effective in prevention and care, and on how they can contribute to global efforts against the disease. For GPA, any group of people linked by feelings of trust, mutual support and a common destiny may be seen as a family. The concept need not be limited to ties of blood, marriage, sexual partnership or adoption. In this light, religious congregations, workers' associations, support groups of people with HIV/AIDS, gangs of street children, circles of drug injectors, collectives of sex workers and networks of governmental, nongovernmental and intergovernmental organizations may all be regarded as families within the over-arching family of humankind. Every kind of family should take care to protect its members from HIV. And all families should take care of those among them who fall ill with AIDS. Families take care. "Families whose bonds are based on love, trust, nurturing and openness are best placed to protect their members from infection and give compassionate care and support to those affected by HIV or AIDS," says Dr. Hiroshi Nakajima, Director-General of the WHO [World Health Organization]. PMID:12287963

  15. Antibody blocks acquisition of bacterial colonization through agglutination

    PubMed Central

    Roche, A. M.; Richard, A. L.; Rahkola, J. T.; Janoff, E. N.; Weiser, J. N.

    2014-01-01

    Invasive infection often begins with asymptomatic colonization of mucosal surfaces. A murine model of bacterial colonization with Streptococcus pneumoniae was used to study the mechanism for mucosal protection by immunoglobulin. In previously colonized immune mice, bacteria were rapidly sequestered within large aggregates in the nasal lumen. To further examine the role of bacterial agglutination in protection by specific antibodies, mice were passively immunized with IgG purified from anti-pneumococcal sera or pneumococcal type-specific monoclonal human IgA (hIgA1 or hIgA2). Systemically-delivered IgG accessed the mucosal surface and blocked acquisition of colonization and transmission between littermates. Optimal protection by IgG was independent of Fc fragment and complement and, therefore, did not involve an opsonophagocytic mechanism. Enzymatic digestion or reduction of IgG prior to administration showed that protection required divalent binding that maintained its agglutinating effect. Divalent hIgA1 is cleaved by the pneumococcal member of a family of bacterial proteases that generate monovalent Fabα fragments. Thus, passive immunization with hIgA1 blocked colonization by an IgA1-protease deficient mutant (agglutinated), but not the protease-producing wild-type parent (not agglutinated), whereas protease-resistant hIgA2 agglutinated and blocked colonization by both. Our findings highlight the importance of agglutinating antibodies in mucosal defense and reveal how successful pathogens evade this effect. PMID:24962092

  16. Structure of a bacterial toxin-activating acyltransferase

    PubMed Central

    Greene, Nicholas P.; Hughes, Colin; Koronakis, Vassilis

    2015-01-01

    Secreted pore-forming toxins of pathogenic Gram-negative bacteria such as Escherichia coli hemolysin (HlyA) insert into host–cell membranes to subvert signal transduction and induce apoptosis and cell lysis. Unusually, these toxins are synthesized in an inactive form that requires posttranslational activation in the bacterial cytosol. We have previously shown that the activation mechanism is an acylation event directed by a specialized acyl-transferase that uses acyl carrier protein (ACP) to covalently link fatty acids, via an amide bond, to specific internal lysine residues of the protoxin. We now reveal the 2.15-Å resolution X-ray structure of the 172-aa ApxC, a toxin-activating acyl-transferase (TAAT) from pathogenic Actinobacillus pleuropneumoniae. This determination shows that bacterial TAATs are a structurally homologous family that, despite indiscernible sequence similarity, form a distinct branch of the Gcn5-like N-acetyl transferase (GNAT) superfamily of enzymes that typically use acyl-CoA to modify diverse bacterial, archaeal, and eukaryotic substrates. A combination of structural analysis, small angle X-ray scattering, mutagenesis, and cross-linking defined the solution state of TAATs, with intermonomer interactions mediated by an N-terminal α-helix. Superposition of ApxC with substrate-bound GNATs, and assay of toxin activation and binding of acyl-ACP and protoxin peptide substrates by mutated ApxC variants, indicates the enzyme active site to be a deep surface groove. PMID:26016525

  17. Structure of a bacterial toxin-activating acyltransferase.

    PubMed

    Greene, Nicholas P; Crow, Allister; Hughes, Colin; Koronakis, Vassilis

    2015-06-01

    Secreted pore-forming toxins of pathogenic Gram-negative bacteria such as Escherichia coli hemolysin (HlyA) insert into host-cell membranes to subvert signal transduction and induce apoptosis and cell lysis. Unusually, these toxins are synthesized in an inactive form that requires posttranslational activation in the bacterial cytosol. We have previously shown that the activation mechanism is an acylation event directed by a specialized acyl-transferase that uses acyl carrier protein (ACP) to covalently link fatty acids, via an amide bond, to specific internal lysine residues of the protoxin. We now reveal the 2.15-Å resolution X-ray structure of the 172-aa ApxC, a toxin-activating acyl-transferase (TAAT) from pathogenic Actinobacillus pleuropneumoniae. This determination shows that bacterial TAATs are a structurally homologous family that, despite indiscernible sequence similarity, form a distinct branch of the Gcn5-like N-acetyl transferase (GNAT) superfamily of enzymes that typically use acyl-CoA to modify diverse bacterial, archaeal, and eukaryotic substrates. A combination of structural analysis, small angle X-ray scattering, mutagenesis, and cross-linking defined the solution state of TAATs, with intermonomer interactions mediated by an N-terminal α-helix. Superposition of ApxC with substrate-bound GNATs, and assay of toxin activation and binding of acyl-ACP and protoxin peptide substrates by mutated ApxC variants, indicates the enzyme active site to be a deep surface groove. PMID:26016525

  18. Antibody blocks acquisition of bacterial colonization through agglutination.

    PubMed

    Roche, A M; Richard, A L; Rahkola, J T; Janoff, E N; Weiser, J N

    2015-01-01

    Invasive infection often begins with asymptomatic colonization of mucosal surfaces. A murine model of bacterial colonization with Streptococcus pneumoniae was used to study the mechanism for mucosal protection by immunoglobulin. In previously colonized immune mice, bacteria were rapidly sequestered within large aggregates in the nasal lumen. To further examine the role of bacterial agglutination in protection by specific antibodies, mice were passively immunized with immunoglobulin G (IgG) purified from antipneumococcal sera or pneumococcal type-specific monoclonal human IgA (hIgA1 or hIgA2). Systemically delivered IgG accessed the mucosal surface and blocked acquisition of colonization and transmission between littermates. Optimal protection by IgG was independent of Fc fragment and complement and, therefore, did not involve an opsonophagocytic mechanism. Enzymatic digestion or reduction of IgG before administration showed that protection required divalent binding that maintained its agglutinating effect. Divalent hIgA1 is cleaved by the pneumococcal member of a family of bacterial proteases that generate monovalent Fabα fragments. Thus, passive immunization with hIgA1 blocked colonization by an IgA1-protease-deficient mutant (agglutinated) but not the protease-producing wild-type parent (not agglutinated), whereas protease-resistant hIgA2 agglutinated and blocked colonization by both. Our findings highlight the importance of agglutinating antibodies in mucosal defense and reveal how successful pathogens evade this effect. PMID:24962092

  19. Does Addiction Run in Families?

    MedlinePlus

    ... Addiction Run in Families? Does Addiction Run in Families? Listen Addiction can run in families. If people ... Español English Español "Heart disease runs in some families. Addiction runs in ours." Matt's family has a ...

  20. Nontraditional family romance.

    PubMed

    Corbett, K

    2001-07-01

    Family stories lie at the heart of psychoanalytic developmental theory and psychoanalytic clinical technique, but whose family? Increasingly, lesbian and gay families, multiparent families, and single-parent families are relying on modern reproductive technologies to form families. The contemplation of these nontraditional families and the vicissitudes of contemporary reproduction lead to an unknowing of what families are, including the ways in which psychoanalysts configure the family within developmental theory. This article focuses on the stories that families tell in order to account for their formation--stories that include narratives about parental union, parental sexuality, and conception. The author addresses three constructs that inform family stories and that require rethinking in light of the category crises posed by and for the nontraditional family: (1) normative logic, (2) family reverie and the construction of a family romance, and (3) the primal scene. These constructs are examined in tandem with detailed clinical material taken from the psychotherapy of a seven-year-old boy and his two mothers. PMID:11491437

  1. Family dynamics during pregnancy.

    PubMed

    Tomlinson, B; White, M A; Wilson, M E

    1990-06-01

    Pregnancy as a transition in family life is perceived as a crisis by many families. Sociodemographic characteristics of families during pregnancy can serve as important sources of information to nurses in drawing out family strengths and providing assistance during this crisis. Family dynamics were measured in 160 women in the third trimester of pregnancy. Half were in their first pregnancy and half were in their second pregnancy. The research question addressed the relationship between family dynamics and several sociodemographic characteristics. Statistically significant relationships were found between the sociodemographic variables of marital and social status, and several dimensions of family dynamics. Families in which couples were married and who enjoyed a higher social status had more positive family dynamics in the dimensions of individuation, stability, flexibility, mutuality and communication. Race, maternal age and parity were not related to level of family dynamics. Strengths in families who have more positive dynamics may be explained by availability of resources, their expertise in using the system, societal approval of marriage and internal family support from the husband. It is essential for nursing care to include systematic family assessment, socialization in effectively using the health care system and individualized family guidance. PMID:2365908

  2. Contribution of bacterial outer membrane vesicles to innate bacterial defense

    PubMed Central

    2011-01-01

    Background Outer membrane vesicles (OMVs) are constitutively produced by Gram-negative bacteria throughout growth and have proposed roles in virulence, inflammation, and the response to envelope stress. Here we investigate outer membrane vesiculation as a bacterial mechanism for immediate short-term protection against outer membrane acting stressors. Antimicrobial peptides as well as bacteriophage were used to examine the effectiveness of OMV protection. Results We found that a hyper-vesiculating mutant of Escherichia coli survived treatment by antimicrobial peptides (AMPs) polymyxin B and colistin better than the wild-type. Supplementation of E. coli cultures with purified outer membrane vesicles provided substantial protection against AMPs, and AMPs significantly induced vesiculation. Vesicle-mediated protection and induction of vesiculation were also observed for a human pathogen, enterotoxigenic E. coli (ETEC), challenged with polymyxin B. When ETEC with was incubated with low concentrations of vesicles concomitant with polymyxin B treatment, bacterial survival increased immediately, and the culture gained resistance to polymyxin B. By contrast, high levels of vesicles also provided immediate protection but prevented acquisition of resistance. Co-incubation of T4 bacteriophage and OMVs showed fast, irreversible binding. The efficiency of T4 infection was significantly reduced by the formation of complexes with the OMVs. Conclusions These data reveal a role for OMVs in contributing to innate bacterial defense by adsorption of antimicrobial peptides and bacteriophage. Given the increase in vesiculation in response to the antimicrobial peptides, and loss in efficiency of infection with the T4-OMV complex, we conclude that OMV production may be an important factor in neutralizing environmental agents that target the outer membrane of Gram-negative bacteria. PMID:22133164

  3. Familial histiocytic reticulosis (familial haemophagocytic reticulosis)

    PubMed Central

    Marrian, Valerie J.; Sanerkin, N. G.

    1963-01-01

    The clinical and pathological findings are recorded in two siblings who died in early infancy from familial histiocytic (`haemophagocytic') reticulosis. The nature of this condition is obscure but probably represents a primary histiocytosis. The only other family on record is that described by Farquhar and Claireaux (1952) and by Farquhar, Macgregor, and Richmond (1958). Images PMID:16810996

  4. Strengthening Family Practices for Latino Families

    ERIC Educational Resources Information Center

    Chartier, Karen G.; Negroni, Lirio K.; Hesselbrock, Michie N.

    2010-01-01

    This study examined the effectiveness of a culturally adapted Strengthening Families Program (SFP) for Latinos to reduce risks for alcohol and drug use in children. Latino families, predominantly Puerto Rican, with a 9- to 12-year-old child and a parent(s) with a substance abuse problem participated in the study. Pre- and post-tests were conducted…

  5. Putting the "family" back into family therapy.

    PubMed

    Breunlin, Douglas C; Jacobsen, Elizabeth

    2014-09-01

    In this article, we examine the field of family therapy by drawing a distinction between two forms of practice: Whole Family Therapy (WFT), defined as treating the whole family, and Relational Family Therapy (RFT), defined as working with a subsystem of the family or an individual while retaining a systemic lens. Our thesis is that the practice of WFT has been in decline for some time and steps must be taken to keep it from becoming a defunct practice. We consider the trajectory of WFT and RFT throughout the development of family therapy through reference to the people, the literature, training, and practice patterns associated with family therapy. We remind the reader of the many benefits of WFT and suggest that today WFT is likely to be practiced in conjunction with RFT and individual therapy. Since training of family therapists today is largely located in degree-granting programs, we identify constraints to including WFT in such programs. We conclude by offering suggestions that can enhance a program's ability to train students in WFT. PMID:24948531

  6. Analytical solutions for bacterial energy taxis (chemotaxis): Traveling bacterial bands

    NASA Astrophysics Data System (ADS)

    Long, Wei; Hilpert, Markus

    2007-11-01

    Motile bacteria may form bands that travel with a constant speed of propagation through a medium containing a dissolved substrate, to which they respond energy tactically. We generalize the analytical solution by Keller and Segel for such bands by accounting for (1) the presence of a porous medium, (2) substrate consumption described by a Monod kinetics model, and (3) an energy tactic response model derived by Rivero et al. Specifically, we determine the concentration profiles of the bacteria and the substrate. We also derive various expressions for the band velocity. The band velocity is also shown to equal the energy tactic velocity at the bacterial peak divided by tortuosity.

  7. Analysis of Bacterial Diversity During Acetic Acid Fermentation of Tianjin Duliu Aged Vinegar by 454 Pyrosequencing.

    PubMed

    Peng, Qian; Yang, Yanping; Guo, Yanyun; Han, Ye

    2015-08-01

    The vinegar pei harbors complex bacterial communities. Prior studies revealing the bacterial diversity involved were mainly conducted by culture-dependent methods and PCR-DGGE. In this study, 454 pyrosequencing was used to investigate the bacterial communities in vinegar pei during the acetic acid fermentation (AAF) of Tianjin Duliu aged vinegar (TDAV). The results showed that there were 7 phyla and 24 families existing in the vinegar pei, with 2 phyla (Firmicutes, Protebacteria) and 4 families (Lactobacillaceae, Acetobacteracae, Enterobacteriaceae, Chloroplast) predominating. The genus-level identification revealed that 9 genera were the relatively stable, consistent components in different stages of AAF, including the most abundant genus Lactobacillus followed by Acetobacter and Serratia. Additionally, the bacterial community in the early fermentation stage was more complex than those in the later stages, indicating that the accumulation of organic acids provided an appropriate environment to filter unwanted bacteria and to accelerate the growth of required ones. This study provided basic information of bacterial patterns in vinegar pei and relevant changes during AAF of TDAV, and could be used as references in the following study on the implementation of starter culture as well as the improvement of AAF process. PMID:25903266

  8. Family perspective on a family care program.

    PubMed

    Shimizu, Helena Eri; Rosales, Carlos

    2008-01-01

    This study aimed at assessing the family's perspective on a family care program to better understand the challenges and potential capacities for changing the health care model. A qualitative study was carried out to assess the Family Health Program in the city of São Sebastião, Brasília, Brazil. Data was collected through direct systematic observations of the workflow developed by the program's team, and through focal groups with family members. The discourse of the collective subject was used in data analysis and showed that health prevention and promotion actions and the relationship between providers and consumers were positively evaluated while access to health services, drugs and providers was negatively evaluated. There is no assurance of comprehensive and continuous care to the family, which points to the need of reviewing the strategies of health service organization for more effective involvement of the community to meet their health needs. PMID:19061026

  9. Invest in Family*

    PubMed Central

    Shah, Nilesh; De Sousa, Avinash

    2015-01-01

    The family is an integral part of one's life. It is very essential that every individual employed or unemployed invests time therein. The family is a source of support and growth for an individual, and the lack of family support or loneliness may be a causative factor in the genesis of psychiatric disorders, especially depression. In India, family plays a paramount role when it comes to mental health of the individual. Tips on how one should invest time in one's family along with the role of a family in one's personal and social structure are discussed. PMID:25838732

  10. Families of minor planets

    NASA Technical Reports Server (NTRS)

    Gradie, J. C.; Chapman, C. R.; Williams, J. G.

    1979-01-01

    Physical studies of individual family members show that at least the Themis, Eos, Koronis, Nysa/Hertha, and Budrosa families of minor planets are the result of the breakup of discrete parent bodies. Only a few families have been studied in detail, and even in those few cases, the full force of observational techniques has not been applied. Crucial for the understanding of families and their parent bodies are detailed physical studies of family members; precise mineralogical interpretation of observational data to identify the geochemistry of the parent bodies; and studies of the collisional evolution of family members.

  11. Transport of magnesium by a bacterial Nramp-related gene.

    PubMed

    Shin, Jung-Ho; Wakeman, Catherine A; Goodson, Jonathan R; Rodionov, Dmitry A; Freedman, Benjamin G; Senger, Ryan S; Winkler, Wade C

    2014-06-01

    Magnesium is an essential divalent metal that serves many cellular functions. While most divalent cations are maintained at relatively low intracellular concentrations, magnesium is maintained at a higher level (∼0.5-2.0 mM). Three families of transport proteins were previously identified for magnesium import: CorA, MgtE, and MgtA/MgtB P-type ATPases. In the current study, we find that expression of a bacterial protein unrelated to these transporters can fully restore growth to a bacterial mutant that lacks known magnesium transporters, suggesting it is a new importer for magnesium. We demonstrate that this transport activity is likely to be specific rather than resulting from substrate promiscuity because the proteins are incapable of manganese import. This magnesium transport protein is distantly related to the Nramp family of proteins, which have been shown to transport divalent cations but have never been shown to recognize magnesium. We also find gene expression of the new magnesium transporter to be controlled by a magnesium-sensing riboswitch. Importantly, we find additional examples of riboswitch-regulated homologues, suggesting that they are a frequent occurrence in bacteria. Therefore, our aggregate data discover a new and perhaps broadly important path for magnesium import and highlight how identification of riboswitch RNAs can help shed light on new, and sometimes unexpected, functions of their downstream genes. PMID:24968120

  12. Transport of Magnesium by a Bacterial Nramp-Related Gene

    PubMed Central

    Rodionov, Dmitry A.; Freedman, Benjamin G.; Senger, Ryan S.; Winkler, Wade C.

    2014-01-01

    Magnesium is an essential divalent metal that serves many cellular functions. While most divalent cations are maintained at relatively low intracellular concentrations, magnesium is maintained at a higher level (∼0.5–2.0 mM). Three families of transport proteins were previously identified for magnesium import: CorA, MgtE, and MgtA/MgtB P-type ATPases. In the current study, we find that expression of a bacterial protein unrelated to these transporters can fully restore growth to a bacterial mutant that lacks known magnesium transporters, suggesting it is a new importer for magnesium. We demonstrate that this transport activity is likely to be specific rather than resulting from substrate promiscuity because the proteins are incapable of manganese import. This magnesium transport protein is distantly related to the Nramp family of proteins, which have been shown to transport divalent cations but have never been shown to recognize magnesium. We also find gene expression of the new magnesium transporter to be controlled by a magnesium-sensing riboswitch. Importantly, we find additional examples of riboswitch-regulated homologues, suggesting that they are a frequent occurrence in bacteria. Therefore, our aggregate data discover a new and perhaps broadly important path for magnesium import and highlight how identification of riboswitch RNAs can help shed light on new, and sometimes unexpected, functions of their downstream genes. PMID:24968120

  13. Spontaneous bacterial peritonitis: a therapeutic update.

    PubMed

    Strauss, Edna; Caly, Wanda Regina

    2006-04-01

    Spontaneous bacterial peritonitis (SBP) is one of the main infectious complications of cirrhosis and occurs in 8-30% of hospitalized patients with ascites. SBP is characterized by infection of the ascitic fluid (AF) in the absence of any primary focus of intra-abdominal infection. The main route by which the AF becomes infected is the hematogenous route. The pathogenic mechanism by which infection develops is bacterial translocation from the intestinal flora to the mesenteric lymph nodes and from there to the bloodstream. Contributing factors are an increased growth of Gram-negative aerobic bacilli in the jejunum, changes in the intestinal barrier and in addition factors which could reduce the local flow of blood. For clinical diagnosis, patients with SBP may present signs of peritoneal irritation and pain, together with changes in gastrointestinal motility, sometimes with nausea, vomiting, diarrhea or ileus. Many patients, however, may not present any symptoms or signs as a result of the presence of SBP. Diagnostic paracentesis of the AF must be performed for every patient with cirrhosis, hospitalized with ascites. Laboratory diagnosis of SBP is carried out by polymorphonuclear count in the AF, together with a positive culture from the AF, which is characteristically monomicrobial. Escherichia coli has been the main bacterium isolated from AF as well as other Gram-negative bacteria from the Enterobacteriaceae family and Streptococcus genus. A more rapid diagnosis of SBP can be obtained via the use of leukocyte esterase, which is present in biological fluids and reacts with a component of the dipstick, changing its color. During the acute phase of SBP, antibiotics should be initiated promptly once the clinical and laboratory diagnosis of SBP has been made, before the result of AF culture. Cefotaxime or other third-generation cephalosporins have been considered the first-choice empirical antibiotics in the treatment of cirrhotic patients with SBP, and is efficacious in approximately 90% of cases. Broad-spectrum quinolones, which are almost completely absorbed after oral administration and diffuse rapidly through the AF, are currently used for oral treatment of uncomplicated SBP. Patients who have already had a previous episode of SBP, with a 69% probability of recurrence within a year, will benefit from prophylactic treatment. Cirrhotic patients with a high risk of SBP and other infections, such as those with gastrointestinal bleeding, also benefit from primary prophylaxis and norfloxacin has been used with success. PMID:16597206

  14. Distinct soil bacterial communities revealed under a diversely managed agroecosystem.

    PubMed

    Shange, Raymon S; Ankumah, Ramble O; Ibekwe, Abasiofiok M; Zabawa, Robert; Dowd, Scot E

    2012-01-01

    Land-use change and management practices are normally enacted to manipulate environments to improve conditions that relate to production, remediation, and accommodation. However, their effect on the soil microbial community and their subsequent influence on soil function is still difficult to quantify. Recent applications of molecular techniques to soil biology, especially the use of 16S rRNA, are helping to bridge this gap. In this study, the influence of three land-use systems within a demonstration farm were evaluated with a view to further understand how these practices may impact observed soil bacterial communities. Replicate soil samples collected from the three land-use systems (grazed pine forest, cultivated crop, and grazed pasture) on a single soil type. High throughput 16S rRNA gene pyrosequencing was used to generate sequence datasets. The different land use systems showed distinction in the structure of their bacterial communities with respect to the differences detected in cluster analysis as well as diversity indices. Specific taxa, particularly Actinobacteria, Acidobacteria, and classes of Proteobacteria, showed significant shifts across the land-use strata. Families belonging to these taxa broke with notions of copio- and oligotrphy at the class level, as many of the less abundant groups of families of Actinobacteria showed a propensity for soil environments with reduced carbon/nutrient availability. Orders Actinomycetales and Solirubrobacterales showed their highest abundance in the heavily disturbed cultivated system despite the lowest soil organic carbon (SOC) values across the site. Selected soil properties ([SOC], total nitrogen [TN], soil texture, phosphodiesterase [PD], alkaline phosphatase [APA], acid phosphatase [ACP] activity, and pH) also differed significantly across land-use regimes, with SOM, PD, and pH showing variation consistent with shifts in community structure and composition. These results suggest that use of pyrosequencing along with traditional analysis of soil physiochemical properties may provide insight into the ecology of descending taxonomic groups in bacterial communities. PMID:22844402

  15. Distinct Soil Bacterial Communities Revealed under a Diversely Managed Agroecosystem

    PubMed Central

    Shange, Raymon S.; Ankumah, Ramble O.; Ibekwe, Abasiofiok M.; Zabawa, Robert; Dowd, Scot E.

    2012-01-01

    Land-use change and management practices are normally enacted to manipulate environments to improve conditions that relate to production, remediation, and accommodation. However, their effect on the soil microbial community and their subsequent influence on soil function is still difficult to quantify. Recent applications of molecular techniques to soil biology, especially the use of 16S rRNA, are helping to bridge this gap. In this study, the influence of three land-use systems within a demonstration farm were evaluated with a view to further understand how these practices may impact observed soil bacterial communities. Replicate soil samples collected from the three land-use systems (grazed pine forest, cultivated crop, and grazed pasture) on a single soil type. High throughput 16S rRNA gene pyrosequencing was used to generate sequence datasets. The different land use systems showed distinction in the structure of their bacterial communities with respect to the differences detected in cluster analysis as well as diversity indices. Specific taxa, particularly Actinobacteria, Acidobacteria, and classes of Proteobacteria, showed significant shifts across the land-use strata. Families belonging to these taxa broke with notions of copio- and oligotrphy at the class level, as many of the less abundant groups of families of Actinobacteria showed a propensity for soil environments with reduced carbon/nutrient availability. Orders Actinomycetales and Solirubrobacterales showed their highest abundance in the heavily disturbed cultivated system despite the lowest soil organic carbon (SOC) values across the site. Selected soil properties ([SOC], total nitrogen [TN], soil texture, phosphodiesterase [PD], alkaline phosphatase [APA], acid phosphatase [ACP] activity, and pH) also differed significantly across land-use regimes, with SOM, PD, and pH showing variation consistent with shifts in community structure and composition. These results suggest that use of pyrosequencing along with traditional analysis of soil physiochemical properties may provide insight into the ecology of descending taxonomic groups in bacterial communities. PMID:22844402

  16. Bacterial ureases: structure, regulation of expression and role in pathogenesis.

    PubMed

    Collins, C M; D'Orazio, S E

    1993-09-01

    The nickel metalloenzyme urease catalyses the hydrolysis of urea to ammonia and carbamate, and thus generates the preferred nitrogen source of many organisms. When produced by bacterial pathogens in either the urinary tract or the gastroduodenal region, urease acts as a virulence factor. At both sites of infection urease is known to enhance the survival of the infecting bacteria. Ammonia resulting from the action of urease is believed to increase the pH of the environment to one more favourable for growth, and to injure the surrounding epithelial cells. In addition, in the urinary tract urease activity can result in the formation of urinary calculi. Bacterial urease gene clusters contain from seven to nine genes depending upon the species. These genes encode the urease structural subunits and accessory polypeptides involved in the biosynthesis of the nickel metallocentre. So far, three distinct mechanisms of urease gene expression have been described for ureolytic bacteria. Some species constitutively produce urease; some species produce urease only if urea is present in the growth medium; and some species produce urease only during nitrogen-limiting growth conditions. For either the urea-inducible genes or the nitrogen-regulated genes transcription appears to be positively regulated. In the nitrogen-regulated systems, urease gene expression requires Nac (nitrogen assimilation control), a member of the LysR family of transcriptional activators. Urea dependent expression of urease requires UreR (urease regulator), a member of the AraC family of transcriptional activators. An evolutionary tree for urease genes of eight bacterial species is proposed. PMID:7934918

  17. Continuous monitoring of bacterial attachment

    NASA Technical Reports Server (NTRS)

    Koeing, D. W.; Mishra, S. K.; Pierson, D. L.

    1994-01-01

    A major concern with the Space Station Freedom (SSF) water supply system is the control of longterm microbial contamination and biofilm development in the water storage and distribution systems. These biofilms have the potential for harboring pathogens as well as microbial strains containing resistance factors that could negatively influence crew health. The proposed means for disinfecting the water system on SSF (iodine) may encourage the selection of resistant strains. In fact, biofilm bacteria were observed in water lines from the Space Shuttle Columbia (OV-102); therefore, an alternative remediation method is required to disinfect spacecraft water lines. A thorough understanding of colonization events and the physiological parameters that will influence bacteria adhesion is required. The limiting factor for development of this technology is the ability to continuously monitor adhesion events and the effects of biocides on sessile bacteria. Methods were developed to allow bacterial adhesion and subsequent biocidal treatment to be monitored continuously. This technique couples automated image analysis with a continuous flow of a bacterial suspension through an optical flow cell. A strain of Pseudomonas cepacia isolated from the water supply of the Space Shuttle Discovery (OV-103) during STS-39 was grown in a nitrogen-limited continuous culture. This culture was challenged continuously with iodine during growth, and the adhesion characteristics of this strain was measure with regard to flow rate. Various biocides (ozone, hypochlorite, and iodine) were added to the flow stream to evaluate how well each chemical removed the bacteria. After biocide treatment, a fresh bacterial suspension was introduced into the flow cell, and the attachment rate was evaluated on the previously treated surface. This secondary fouling was again treated with biocide to determine the efficacy of multiple batch chemical treatments in removing biofilm.

  18. Bacterial Serine/Threonine Protein Kinases in Host-Pathogen Interactions*

    PubMed Central

    Canova, Marc J.; Molle, Virginie

    2014-01-01

    In bacterial pathogenesis, monitoring and adapting to the dynamically changing environment in the host and an ability to disrupt host immune responses are critical. The virulence determinants of pathogenic bacteria include the sensor/signaling proteins of the serine/threonine protein kinase (STPK) family that have a dual role of sensing the environment and subverting specific host defense processes. STPKs can sense a wide range of signals and coordinate multiple cellular processes to mount an appropriate response. Here, we review some of the well studied bacterial STPKs that are essential virulence factors and that modify global host responses during infection. PMID:24554701

  19. Host Specificity of Bacterial Pathogens

    PubMed Central

    Bäumler, Andreas; Fang, Ferric C.

    2013-01-01

    Most pathogens are able to infect multiple hosts but some are highly adapted to a single-host species. A detailed understanding of the basis of host specificity can provide important insights into molecular pathogenesis, the evolution of pathogenic microbes, and the potential for pathogens to cross the species barrier to infect new hosts. Comparative genomics and the development of humanized mouse models have provided important new tools with which to explore the basis of generalism and specialism. This review will examine host specificity of bacterial pathogens with a focus on generalist and specialist serovars of Salmonella enterica. PMID:24296346

  20. Magnetic microbes: Bacterial magnetite biomineralization

    SciTech Connect

    Prozorov, Tanya

    2015-09-14

    Magnetotactic bacteria are a diverse group of prokaryotes with the ability to orient and migrate along the magnetic field lines in search for a preferred oxygen concentration in chemically stratified water columns and sediments. These microorganisms produce magnetosomes, the intracellular nanometer-sized magnetic crystals surrounded by a phospholipid bilayer membrane, typically organized in chains. Magnetosomes have nearly perfect crystal structures with narrow size distribution and species-specific morphologies, leading to well-defined magnetic properties. As a result, the magnetite biomineralization in these organisms is of fundamental interest to diverse disciplines, from biotechnology to astrobiology. As a result, this article highlights recent advances in the understanding of the bacterial magnetite biomineralization.

  1. Recognition of Bacterial Signal Peptides by Mammalian Formyl Peptide Receptors

    PubMed Central

    Bufe, Bernd; Schumann, Timo; Kappl, Reinhard; Bogeski, Ivan; Kummerow, Carsten; Podgórska, Marta; Smola, Sigrun; Hoth, Markus; Zufall, Frank

    2015-01-01

    Formyl peptide receptors (FPRs) are G-protein-coupled receptors that function as chemoattractant receptors in innate immune responses. Here we perform systematic structure-function analyses of FPRs from six mammalian species using structurally diverse FPR peptide agonists and identify a common set of conserved agonist properties with typical features of pathogen-associated molecular patterns. Guided by these results, we discover that bacterial signal peptides, normally used to translocate proteins across cytoplasmic membranes, are a vast family of natural FPR agonists. N-terminally formylated signal peptide fragments with variable sequence and length activate human and mouse FPR1 and FPR2 at low nanomolar concentrations, thus establishing FPR1 and FPR2 as sensitive and broad signal peptide receptors. The vomeronasal receptor mFpr-rs1 and its sequence orthologue hFPR3 also react to signal peptides but are much more narrowly tuned in signal peptide recognition. Furthermore, all signal peptides examined here function as potent activators of the innate immune system. They elicit robust, FPR-dependent calcium mobilization in human and mouse leukocytes and trigger a range of classical innate defense mechanisms, such as the production of reactive oxygen species, metalloprotease release, and chemotaxis. Thus, bacterial signal peptides constitute a novel class of immune activators that are likely to contribute to mammalian immune defense against bacteria. This evolutionarily conserved detection mechanism combines structural promiscuity with high specificity and enables discrimination between bacterial and eukaryotic signal sequences. With at least 175,542 predicted sequences, bacterial signal peptides represent the largest and structurally most heterogeneous class of G-protein-coupled receptor agonists currently known for the innate immune system. PMID:25605714

  2. Vaginal microbiome and metabolome highlight specific signatures of bacterial vaginosis.

    PubMed

    Vitali, B; Cruciani, F; Picone, G; Parolin, C; Donders, G; Laghi, L

    2015-12-01

    In this study, we sought to find novel bacterial and metabolic hallmarks for bacterial vaginosis (BV). We studied the vaginal microbiome and metabolome of vaginal fluids from BV-affected patients (n = 43) and healthy controls (n = 37) by means of an integrated approach based on quantitative polymerase chain reaction (qPCR) and proton nuclear magnetic resonance ((1)H-NMR). The correlations between the clinical condition and vaginal bacterial communities were investigated by principal component analysis (PCA). To define the metabolomics signatures of BV, 100 discriminant analysis by projection on latent structure (PLS-DA) models were calculated. Bacterial signatures distinguishing the health condition and BV were identified by qPCR. Lactobacillus crispatus strongly featured the healthy vagina, while increased concentrations of Prevotella, Atopobium and Mycoplasma hominis specifically marked the infection. (1)H-NMR analysis has led to the identification and quantification of 17 previously unreported molecules. BV was associated with changes in the concentration of metabolites belonging to the families of amines, organic acids, short chain fatty acids, amino acids, nitrogenous bases and monosaccharides. In particular, maltose, kynurenine and NAD(+) primarily characterised the healthy status, while nicotinate, malonate and acetate were the best metabolic hallmarks of BV. This study helps to better understand the role of the vaginal microbiota and metabolome in the development of BV infection. We propose a molecular approach for the diagnosis of BV based on quantitative detection in the vaginal fluids of Atopobium, Prevotella and M. hominis, and nicotinate, malonate and acetate by combining qPCR and (1)H-NMR. PMID:26385347

  3. Aedesin: Structure and Antimicrobial Activity against Multidrug Resistant Bacterial Strains

    PubMed Central

    Padilla, André; Hamel, Rodolphe; Luplertlop, Natthanej; Chauffour, Aurélie; Vittecoq, Marion; Hoh, François; Thomas, Frédéric; Sougakoff, Wladimir; Lionne, Corinne; Yssel, Hans; Missé, Dorothée

    2014-01-01

    Multidrug resistance, which is acquired by both Gram-positive and Gram-negative bacteria, causes infections that are associated with significant morbidity and mortality in many clinical settings around the world. Because of the rapidly increasing incidence of pathogens that have become resistant to all or nearly all available antibiotics, there is a need for a new generation of antimicrobials with a broad therapeutic range for specific applications against infections. Aedesin is a cecropin-like anti-microbial peptide that was recently isolated from dengue virus-infected salivary glands of the Aedes aegypti mosquito. In the present study, we have refined the analysis of its structural characteristics and have determined its antimicrobial effects against a large panel of multidrug resistant bacterial strains, directly isolated from infected patients. Based the results from nuclear magnetic resonance spectroscopy analysis, Aedesin has a helix-bend-helix structure typical for a member of the family of α-helix anti-microbial peptides. Aedesin efficiently killed Gram-negative bacterial strains that display the most worrisome resistance mechanisms encountered in the clinic, including resistance to carbapenems, aminoglycosides, cephalosporins, 4th generation fluoroquinolones, folate inhibitors and monobactams. In contrast, Gram-positive strains were insensitive to the lytic effects of the peptide. The anti-bacterial activity of Aedesin was found to be salt-resistant, indicating that it is active under physiological conditions encountered in body fluids characterized by ionic salt concentrations. In conclusion, because of its strong lytic activity against multidrug resistant Gram-negative bacterial strains displaying all types of clinically relevant resistance mechanisms known today, Aedesin might be an interesting candidate for the development of alternative treatment for infections caused by these types of bacteria. PMID:25162372

  4. Bacterial expression of self-assembling peptide hydrogelators

    NASA Astrophysics Data System (ADS)

    Sonmez, Cem

    For tissue regeneration and drug delivery applications, various architectures are explored to serve as biomaterial tools. Via de novo design, functional peptide hydrogel materials have been developed as scaffolds for biomedical applications. The objective of this study is to investigate bacterial expression as an alternative method to chemical synthesis for the recombinant production of self-assembling peptides that can form rigid hydrogels under physiological conditions. The Schneider and Pochan Labs have designed and characterized a 20 amino acid beta-hairpin forming amphiphilic peptide containing a D-residue in its turn region (MAX1). As a result, this peptide must be prepared chemically. Peptide engineering, using the sequence of MAX1 as a template, afforded a small family of peptides for expression (EX peptides) that have different turn sequences consisting of natural amino acids and amenable to bacterial expression. Each sequence was initially chemically synthesized to quickly assess the material properties of its corresponding gel. One model peptide EX1, was chosen to start the bacterial expression studies. DNA constructs facilitating the expression of EX1 were designed in such that the peptide could be expressed with different fusion partners and subsequently cleaved by enzymatic or chemical means to afford the free peptide. Optimization studies were performed to increase the yield of pure peptide that ultimately allowed 50 mg of pure peptide to be harvested from one liter of culture, providing an alternate means to produce this hydrogel-forming peptide. Recombinant production of other self-assembling hairpins with different turn sequences was also successful using this optimized protocol. The studies demonstrate that new beta-hairpin self-assembling peptides that are amenable to bacterial production and form rigid hydrogels at physiological conditions can be designed and produced by fermentation in good yield at significantly reduced cost when compared to chemical synthesis.

  5. Family Learning Vacation.

    ERIC Educational Resources Information Center

    Carbin, Clifton F.

    1986-01-01

    "Family learning vacations" 5-10 day summer residential programs for families with deaf children, are described. Guidelines for establishing such a program are given concerning rationale, physical plant, eligibility, scheduling, parent activities, children's activities, and evaluation. (Author/DB)

  6. Assessing Postpartum Family Functioning

    PubMed Central

    Midmer, Deana; Talbot, Yves

    1988-01-01

    The birth of a child requires adaptation and reorganization within the family system in order to accommodate the new family member and to allow the family to continue in its psychosocial development. Knowledge of the normative and transitional changes required at this stage of family life will enhance family practitioners' understanding of some of the common concerns and complaints related to them by various family members during the postpartum period. The Family FIRO model represents a helpful conceptual framework to increase the family physician's understanding of the issues of inclusion, control, and intimacy that are highlighted during the transition to parenthood. The authors briefly present this model and discuss its application to postpartum adjustment and its implications for health-care professionals. PMID:21253238

  7. Dual-Earner Families.

    ERIC Educational Resources Information Center

    Aldous, Joan, Ed.

    1981-01-01

    Presents eight articles focused on dual-earner families in terms of career choices, family adjustment problems, role conflicts, marital relationships, housework activities, and preschool children's sex role identities. (HLM)

  8. Familial Periodic Paralyses

    MedlinePlus

    ... NINDS NINDS Familial Periodic Paralyses Information Page Synonym(s): Periodic Paralyses Table of Contents (click to jump to sections) What are Familial Periodic Paralyses? Is there any treatment? What is the ...

  9. Bacterial communities involved in soil formation and plant establishment triggered by pyrite bioweathering on arctic moraines.

    PubMed

    Mapelli, Francesca; Marasco, Ramona; Rizzi, Agostino; Baldi, Franco; Ventura, Stefano; Daffonchio, Daniele; Borin, Sara

    2011-02-01

    In arctic glacier moraines, bioweathering primed by microbial iron oxidizers creates fertility gradients that accelerate soil development and plant establishment. With the aim of investigating the change of bacterial diversity in a pyrite-weathered gradient, we analyzed the composition of the bacterial communities involved in the process by sequencing 16S rRNA gene libraries from different biological soil crusts (BSC). Bacterial communities in three BSC of different morphology, located within 1 m distance downstream a pyritic conglomerate rock, were significantly diverse. The glacier moraine surrounding the weathered site showed wide phylogenetic diversity and high evenness with 15 represented bacterial classes, dominated by Alphaproteobacteria and pioneer Cyanobacteria colonizers. The bioweathered area showed the lowest diversity indexes and only nine bacterial families, largely dominated by Acidobacteriaceae and Acetobacteraceae typical of acidic environments, in accordance with the low pH of the BSC. In the weathered BSC, iron-oxidizing bacteria were cultivated, with counts decreasing along with the increase of distance from the rock, and nutrient release from the rock was revealed by environmental scanning electron microscopy-energy dispersive X-ray analyses. The vegetated area showed the presence of Actinomycetales, Verrucomicrobiales, Gemmatimonadales, Burkholderiales, and Rhizobiales, denoting a bacterial community typical of developed soils and indicating that the lithoid substrate of the bare moraine was here subjected to an accelerated colonization, driven by iron-oxidizing activity. PMID:20953598

  10. Avian Incubation Inhibits Growth and Diversification of Bacterial Assemblages on Eggs

    PubMed Central

    Shawkey, Matthew D.; Firestone, Mary K.; Brodie, Eoin L.; Beissinger, Steven R.

    2009-01-01

    Microbial infection is a critical source of mortality for early life stages of oviparous vertebrates, but parental defenses against infection are less well known. Avian incubation has been hypothesized to reduce the risk of trans-shell infection by limiting microbial growth of pathogenic bacteria on eggshells, while enhancing growth of commensal or beneficial bacteria that inhibit or competitively exclude pathogens. We tested this hypothesis by comparing bacterial assemblages on naturally incubated and experimentally unincubated eggs at laying and late incubation using a universal 16S rRNA microarray containing probes for over 8000 bacterial taxa. Before treatment, bacterial assemblages on individual eggs from both treatment groups were dissimilar to one another, as measured by clustering in non-metric dimensional scaling (NMDS) ordination space. After treatment, assemblages of unincubated eggs were similar to one another, but those of incubated eggs were not. Furthermore, assemblages of unincubated eggs were characterized by high abundance of six indicator species while incubated eggs had no indicator species. Bacterial taxon richness remained static on incubated eggs, but increased significantly on unincubated eggs, especially in several families of Gram-negative bacteria. The relative abundance of individual bacterial taxa did not change on incubated eggs, but that of 82 bacterial taxa, including some known to infect the interior of eggs, increased on unincubated eggs. Thus, incubation inhibits all of the relatively few bacteria that grow on eggshells, and does not appear to promote growth of any bacteria. PMID:19225566

  11. Interaction between resource identity and bacterial community composition regulates bacterial respiration in aquatic ecosystems.

    PubMed

    Pires, A P F; Caliman, A; Laque, T; Esteves, F A; Farjalla, V F

    2015-11-01

    Resource identity and composition structure bacterial community, which in turn determines the magnitude of bacterial processes and ecological services. However, the complex interaction between resource identity and bacterial community composition (BCC) has been poorly understood so far. Using aquatic microcosms, we tested whether and how resource identity interacts with BCC in regulating bacterial respiration and bacterial functional diversity. Different aquatic macrophyte leachates were used as different carbon resources while BCC was manipulated through successional changes of bacterial populations in batch cultures. We observed that the same BCC treatment respired differently on each carbon resource; these resources also supported different amounts of bacterial functional diversity. There was no clear linear pattern of bacterial respiration in relation to time succession of bacterial communities in all leachates, i.e. differences on bacterial respiration between different BCC were rather idiosyncratic. Resource identity regulated the magnitude of respiration of each BCC, e.g. Ultricularia foliosa leachate sustained the greatest bacterial functional diversity and lowest rates of bacterial respiration in all BCC. We conclude that both resource identity and the BCC interact affecting the pattern and the magnitude of bacterial respiration in aquatic ecosystems. PMID:26602341

  12. Family Sex Communication Orientation.

    ERIC Educational Resources Information Center

    Warren, Clay; Neer, Michael

    1986-01-01

    Suggests (1) family sex communication is infrequent and ineffective, (2) frequent, effective family sex communication may serve as a contextual model for children's communication patterns, (3) strong family sex communication orientation seems to facilitate children's open discussion with dates and parents, and develops responsible pre-parenting…

  13. The Resiliency of Families.

    ERIC Educational Resources Information Center

    Morrison, T. R.

    According to researchers, the family may be changing but it is still one of the central institutions in society. Studies report a shift in more than 20 attitudes and values, most of which relate to the context of family life. Specifically, these include attitudes toward marriage, divorce, childbearing, childrearing, working women, family violence,…

  14. Year of the Family.

    ERIC Educational Resources Information Center

    California Agriculture, 1994

    1994-01-01

    This special issue focuses on problems and challenges confronting the California family and on research and extension efforts to provide at least partial answers. Research briefs by staff include "Challenges Confront the California Family" (state trends in poverty, divorce, single-parent families, child abuse, delinquency, teen births, limited…

  15. Families and Assisted Living*

    PubMed Central

    Gaugler, Joseph E.; Kane, Robert L.

    2008-01-01

    Purpose Despite growing research on assisted living (AL) as a residential care option for older adults, the social ramifications of residents' transitions to assisted living is relatively unexplored. This article examines family involvement in AL, including family structures of residents, types of involvement from family members living outside the AL, and outcomes for these family members. Design and Methods We reviewed current literature utilizing the MEDLINE, PSYCINFO, and CINAHL databases to identify AL studies that examined issues pertaining to families or informal care. Following the screening of abstracts, 180 reports were retrieved for further review, and 62 studies were selected for inclusion. Results Families visit residents frequently and provide a wide range of instrumental assistance but provide only minimal personal care. Studies of family outcomes indicated relatively high satisfaction, but potential care burden as well. Implications How family care and involvement occurs in AL in relation to formal care provision and whether various types of formal-informal care integration influence family outcomes remains unclear. We suggest a research agenda that attempts to tease out causal relationships for family involvement, differentiate family roles, and implement longitudinal analyses for a range of family outcomes. PMID:18162571

  16. Learning from Latino Families

    ERIC Educational Resources Information Center

    Auerbach, Susan

    2011-01-01

    As a researcher in parent engagement in school and former parent activist, the author shares three lessons for sparking more authentic partnerships between schools and immigrant families. First, schools need to move away from deficit thinking and validate families' cultures. In the case of Latino immigrant families, this entails understanding…

  17. Fatherhood and Family Support.

    ERIC Educational Resources Information Center

    Goetz, Kathy, Ed.

    1996-01-01

    On the assumption that fathers have been relatively absent from family support programs, this publication of the Family Resource Coalition addresses the role of fathers in family support programs, examines the impact of fathers on their children, and describes programs involving fathers successfully. Articles include: (1) "What's Behind the…

  18. Establishing Family Math.

    ERIC Educational Resources Information Center

    Bobango, Janet, Milgram, Joel

    1993-01-01

    The Family Math Program is an outgrowth of the Equals Program at the Lawrence Hall of Science at UC Berkeley. Piloted in 1982 in Richmond, California, this widespread program boasts a simple philosophy: Families "doing math" will get the same result as families who read--improved skills and enjoyment. The program also confronts parental math…

  19. Focus on the Family.

    ERIC Educational Resources Information Center

    Hardy, James M.

    This research attempts to evaluate the YMCA's program in terms of its effect upon the family members it serves. The study was designed to: (1) classify, by descriptive types, the various kinds of YMCA operations which serve the family, identifying their characteristic differences; (2) examine and describe operating practices of family YMCAs…

  20. Family Customs and Traditions.

    ERIC Educational Resources Information Center

    MacGregor, Cynthia

    Recognizing the importance of maintaining open communication with immediate and extended family members, this book provides a compilation of ideas for family traditions and customs that are grounded in compassion and human kindness. The traditions were gathered from families in the United States and Canada who responded to advertisements in…

  1. Religion and the Family.

    ERIC Educational Resources Information Center

    Thomas, Darwin L., Ed.

    1985-01-01

    Examines religion's place in the social sciences, reciprocal influences of family and religion, cohesion/polarization in American Catholic families, religion in Middletown, USA, gender and religion in Canadian and American students, domestic/religious individualism and suicide, and the New Christian Right's view of the family. (BH)

  2. Family Violence: An Overview.

    ERIC Educational Resources Information Center

    National Center on Child Abuse and Neglect (DHHS/OHDS), Washington, DC.

    Family violence is a widespread problem; research has shown multiple factors are associated with family violence. Types of family violence include spouse abuse; elder abuse and neglect; child abuse and neglect; parent abuse; and sibling abuse. There are three types of spouse abuse: physical abuse, sexual violence, and psychological/emotional…

  3. Families for All Children.

    ERIC Educational Resources Information Center

    Shoultz, Bonnie, Ed.; Kalyanpur, Maya, Ed.

    This bulletin reflects the commitment of Syracuse University's Center on Human Policy to the idea that children belong with families. The bulletin contains a policy statement which recommends; that all children, regardless of disability, belong with families and need enduring relationships with adults; that families with severely disabled children…

  4. Doing Better for Families

    ERIC Educational Resources Information Center

    OECD Publishing (NJ3), 2011

    2011-01-01

    All OECD governments want to give parents more choice in their work and family decisions. This book looks at the different ways in which governments support families. It seeks to provide answers to questions like: Is spending on family benefits going up, and how does it vary by the age of the child? Has the crisis affected public support for…

  5. Families in Transition.

    ERIC Educational Resources Information Center

    Britton, Patti O., Ed.; McGee, Michael, Ed.

    1987-01-01

    This issue of "Emphasis" deals with families in transition, providing some model programs for the new family and some historical perspectives on how families have developed over time. Articles include: (1) "Nostalgia on the Right" (Nancy Theriot); (2) "Heart to Heart" (Nancy Harrington-MacLennan); (3) "The Media Get the Message" (Janet Alyn); (4)…

  6. The Family Leukemia Association

    ERIC Educational Resources Information Center

    Pollitt, Eleanor

    1976-01-01

    An association of families of children with leukemia, the Family Leukemia Association (FLA), was recently established in Toronto. This paper discusses (a) philosophy of the FLA; (b) formative years of this organization; (c) problems encountered by leukemic children and their families; and (d) the FLA's past and future educational and social…

  7. Family Counseling Psychology.

    ERIC Educational Resources Information Center

    Levant, Ronald F., ed.

    1983-01-01

    Describes programs for family counseling which use psychological-educational and skills training methods to remediate individual and family problems or enhance family life. The six articles discuss client-centered skills training, behavioral approaches, cognitive behavioral marital therapy, Adlerian parent education, and couple communication. (JAC)

  8. Insight into the bacterial gut microbiome of the North American moose (Alces alces)

    PubMed Central

    2012-01-01

    Background The work presented here provides the first intensive insight into the bacterial populations in the digestive tract of the North American moose (Alces alces). Eight free-range moose on natural pasture were sampled, producing eight rumen samples and six colon samples. Second generation (G2) PhyloChips were used to determine the presence of hundreds of operational taxonomic units (OTUs), representing multiple closely related species/strains (>97% identity), found in the rumen and colon of the moose. Results A total of 789 unique OTUs were used for analysis, which passed the fluorescence and the positive fraction thresholds. There were 73 OTUs, representing 21 bacterial families, which were found exclusively in the rumen samples: Lachnospiraceae, Prevotellaceae and several unclassified families, whereas there were 71 OTUs, representing 22 bacterial families, which were found exclusively in the colon samples: Clostridiaceae, Enterobacteriaceae and several unclassified families. Overall, there were 164 OTUs that were found in 100% of the samples. The Firmicutes were the most dominant bacteria phylum in both the rumen and the colon. Microarray data available at ArrayExpress, accession number E-MEXP-3721. Conclusions Using PhyloTrac and UniFrac computer software, samples clustered into two distinct groups: rumen and colon, confirming that the rumen and colon are distinct environments. There was an apparent correlation of age to cluster, which will be validated by a larger sample size in future studies, but there were no detectable trends based upon gender. PMID:22992344

  9. A stable live bacterial vaccine.

    PubMed

    Kunda, Nitesh K; Wafula, Denis; Tram, Meilinn; Wu, Terry H; Muttil, Pavan

    2016-06-01

    Formulating vaccines into a dry form enhances its thermal stability. This is critical to prevent administering damaged and ineffective vaccines, and to reduce its final cost. A number of vaccines in the market as well as those being evaluated in the clinical setting are in a dry solid state; yet none of these vaccines have achieved long-term stability at high temperatures. We used spray-drying to formulate a recombinant live attenuated Listeria monocytogenes (Lm; expressing Francisella tularensis immune protective antigen pathogenicity island protein IglC) bacterial vaccine into a thermostable dry powder using various sugars and an amino acid. Lm powder vaccine showed minimal loss in viability when stored for more than a year at ambient room temperature (∼23°C) or for 180days at 40°C. High temperature viability was achieved by maintaining an inert atmosphere in the storage container and removing oxygen free radicals that damage bacterial membranes. Further, in vitro antigenicity was confirmed by infecting a dendritic cell line with cultures derived from spray dried Lm and detection of an intracellularly expressed protective antigen. A combination of stabilizing excipients, a cost effective one-step drying process, and appropriate storage conditions could provide a viable option for producing, storing and transporting heat-sensitive vaccines, especially in regions of the world that require them the most. PMID:27020530

  10. Bacterial Strain Diversity Within Wounds

    PubMed Central

    Kirkup, Benjamin C.

    2015-01-01

    Significance: Rare bacterial taxa (taxa of low relative frequency) are numerous and ubiquitous in virtually any sample—including wound samples. In addition, even the high-frequency genera and species contain multiple strains. These strains, individually, are each only a small fraction of the total bacterial population. Against the view that wounds contain relatively few kinds of bacteria, this newly recognized diversity implies a relatively high rate of migration into the wound and the potential for diversification during infection. Understanding the biological and medical importance of these numerous taxa is an important new element of wound microbiology. Recent Advances: Only recently have these numerous strains been discovered; the technology to detect, identify, and characterize them is still in its infancy. Multiple strains of both gram-negative and gram-positive bacteria have been found in a single wound. In the few cases studied, the distribution of the bacteria suggests microhabitats and biological interactions. Critical Issues: The distribution of the strains, their phenotypic diversity, and their interactions are still largely uncharacterized. The technologies to investigate this level of genomic detail are still developing and have not been largely deployed to investigate wounds. Future Directions: As advanced metagenomics, single-cell genomics, and advanced microscopy develop, the study of wound microbiology will better address the complex interplay of numerous individually rare strains with both the host and each other. PMID:25566411

  11. Bacterial contamination of eyedrop dispensers.

    PubMed

    Coad, C T; Osato, M S; Wilhelmus, K R

    1984-11-01

    We undertook an in vitro investigation of the role of the design of the eyedrop dispenser in bacterial contamination. The nozzle tips of pipette and squeeze bottles containing Fluress (pH 5.0) were inoculated with 10 microliter of an ocular isolate of Pseudomonas aeruginosa (5.5 X 10(5) bacteria/ml). Cultures of single drops of ophthalmic solution (25-microliter drops from each pipette bottle and 40-microliter drops from each squeeze bottle) were done one minute, 15 minutes, one hour, two hours, and 24 hours after inoculation. Swabs from the inside of the caps of the eyedrop bottles were also cultured at similar intervals. No bacteria were recovered from either dispenser type after one hour. Swabbings from the caps of the pipette bottles showed no growth within minutes after inoculation, but swabbings from the caps of the squeeze bottles consistently yielded bacteria for 24 hours. We suggest that the cap of the squeeze bottle serves as a potential reservoir for bacterial contamination whereas direct contact of microorganisms with the preservative in an ophthalmic solution by the use of a pipette-type dispenser decreases the risk of microbial contamination and growth. PMID:6437230

  12. The bacterial translation stress response

    PubMed Central

    Starosta, Agata L.; Lassak, Jürgen; Jung, Kirsten; Wilson, Daniel N.

    2014-01-01

    Throughout their life, bacteria need to sense and respond to environmental stress. Thus, such stress responses can require dramatic cellular reprogramming, both at the transcriptional as well as the translational level. This review focuses on the protein factors that interact with the bacterial translational apparatus in order to respond to and cope with different types of environmental stress. For example, the stringent factor RelA interacts with the ribosome to generate ppGpp under nutrient deprivation, whereas a variety of factors have been identified that bind to the ribosome under unfavorable growth conditions to shut-down (RelE, pY, RMF, HPF and EttA) or re-program (MazF, EF4 and BipA) translation. Additional factors have been identified that rescue ribosomes stalled due to stress-induced mRNA truncation (tmRNA, ArfA, ArfB), translation of unfavorable protein sequences (EF-P), heat shock induced subunit dissociation (Hsp15) or antibiotic inhibition (TetM, FusB). Understanding the mechanism of how the bacterial cell responds to stress will not only provide fundamental insight into translation regulation, but will also be an important step to identifying new targets for the development of novel antimicrobial agents. PMID:25135187

  13. Bacterial hemagglutination by Neisseria gonorrhoeae.

    PubMed Central

    Koransky, J R; Scales, R W; Kraus, S J

    1975-01-01

    Direct bacterial hemagglutination was investigated with 20 clinical isolates of Neisseria gonorrhoeae. The hemagglutination tests were performed by both a macrotechnique with glass slides and a microtechnique with autotrays. Only organisms from form type 1 or 2 colonies caused hemagglutination. There was no statistical difference at a 10% or higher level in hemagglutination powers of type 1 and type 2 organisms, of male urethral and female cervical isolates, and of the eight major human blood types (ABO-Rh). Of seven erythrocyte species tested, only human cells were agglutinated. D-Mannose did not prevent the agglutination. Rabbit antigonococcal serum and high-titer antigonococcal human sera inhibited the hemagglutination. The results suggest the pili are the mediators of hemagglutination and that their specific agglutination of human erythrocytes may be a correlate of their adherence to human mucosal cells in natural infection. Also, although the procedure is presently insensitive, it is possible to detect human antigonococcal antibody by inhibition of direct bacterial hemagglutination. Images PMID:809353

  14. Bacterial Inhibitors in Lake Water

    PubMed Central

    Klein, Theodore M.; Alexander, Martin

    1986-01-01

    The populations of six bacterial genera fell rapidly after their addition to sterile lake water but not after their addition to buffer. The decline in numbers of two species that were studied further, Klebsiella pneumoniae and Micrococcus flavus, occurred even when the buffer was added to sterile lake water. The inhibition of K. pneumoniae by substances in lake water varied with the season of the year, and the rate and extent of decline of both species were different in sterile samples of different lakes. The extent of reduction in the density of K. pneumoniae was independent of initial population size and was diminished by the addition of 10 μg of glucose per ml of lake water. The toxin was removed from lake water by dialysis and by a cation-exchange resin but not by an anion-exchange resin, and it was destroyed by heating. The inhibition of K. pneumoniae was not evident in lake water buffered at a pH value above 8.0. We suggest that toxins may be important in determining the composition of the bacterial community of lakes. PMID:16347097

  15. Chromophore-enhanced bacterial photothermolysis

    NASA Astrophysics Data System (ADS)

    Huckleby, Jana K.; Morton, Rebecca J.; Bartels, Kenneth E.

    1999-06-01

    The use of chromophore dyes to enhance the bactericidal effect of laser energy was studied as a means to optimize laser treatment for the decontamination of wound. Using an in vitro study, various concentrations of indocyanine green (ICG), carbon black, and fluorescein were mixed with a suspension of bacteria and plated on tryptic soy agar. Plates were exposed to a laser beam of 10-15 watts for times ranging from 0 to 180 seconds, incubated overnight, and colony counts were performed. Bacteria not mixed with chromophore were used as controls. Six bacterial strains encompassing a range of bacterial types were used: Staphylococcus aureau, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus spore suspensions, and Clostridium perfringens. Laser treatment alone had no effect on any of the bacteria. Significant killing of gram-positive bacteria, including spores of Bacillus cereus, was observed only with the use of ICG and diode laser energy. No effect was observed using any of the chromophores on the gram-negative bacteria. The results of this study indicate that successful killing of gram-positive bacteria can be achieved using ICG combined with appropriate laser energy and wavelength. Efforts to enhance the susceptibility of gram-negative bacteria to photothermolysis by laser energy were unsuccessful.

  16. Bacterial Meningitis in the Infant

    PubMed Central

    Ku, Lawrence C.; Boggess, Kim A.

    2014-01-01

    SYNOPSIS Neonatal bacterial meningitis is an uncommon but devastating infection. Although the incidence and mortality have declined over the last several decades, morbidity among survivors remains high. The types and distribution of causative pathogens are related to birth gestational age, postnatal age, and geographic region. Confirming the diagnosis of meningitis can be difficult. Clinical signs are often subtle, and the lumbar puncture is frequently deferred in clinically unstable infants. When obtained, confirmatory testing with cerebrospinal fluid (CSF) culture is often compromised by antepartum or postnatal antibiotic exposure. While blood cultures and CSF parameters may be helpful in cases where the diagnosis is uncertain, bacterial meningitis occurs in infants without bacteremia and with normal CSF parameters. Newer tests such as the polymerase chain reaction are promising but require further study. Prompt treatment with appropriate antibiotics is essential to optimize outcomes. Successful efforts to prevent meningitis in infants have included the use of intrapartum antibiotic prophylaxis against Group B Streptococcus (GBS). Clinical trials investigating the use of a GBS vaccine for the prevention of neonatal GBS disease are ongoing. PMID:25677995

  17. Organization of the bacterial chromosome.

    PubMed Central

    Krawiec, S; Riley, M

    1990-01-01

    Recent progress in studies on the bacterial chromosome is summarized. Although the greatest amount of information comes from studies on Escherichia coli, reports on studies of many other bacteria are also included. A compilation of the sizes of chromosomal DNAs as determined by pulsed-field electrophoresis is given, as well as a discussion of factors that affect gene dosage, including redundancy of chromosomes on the one hand and inactivation of chromosomes on the other hand. The distinction between a large plasmid and a second chromosome is discussed. Recent information on repeated sequences and chromosomal rearrangements is presented. The growing understanding of limitations on the rearrangements that can be tolerated by bacteria and those that cannot is summarized, and the sensitive region flanking the terminator loci is described. Sources and types of genetic variation in bacteria are listed, from simple single nucleotide mutations to intragenic and intergenic recombinations. A model depicting the dynamics of the evolution and genetic activity of the bacterial chromosome is described which entails acquisition by recombination of clonal segments within the chromosome. The model is consistent with the existence of only a few genetic types of E. coli worldwide. Finally, there is a summary of recent reports on lateral genetic exchange across great taxonomic distances, yet another source of genetic variation and innovation. PMID:2087223

  18. Coral microbial community dynamics in response to anthropogenic impacts near a major city in the central Red Sea.

    PubMed

    Ziegler, Maren; Roik, Anna; Porter, Adam; Zubier, Khalid; Mudarris, Mohammed S; Ormond, Rupert; Voolstra, Christian R

    2016-04-30

    Coral-associated bacteria play an increasingly recognized part in coral health. We investigated the effect of local anthropogenic impacts on coral microbial communities on reefs near Jeddah, the largest city on the Saudi Arabian coast of the central Red Sea. We analyzed the bacterial community structure of water and corals (Pocillopora verrucosa and Acropora hemprichii) at sites that were relatively unimpacted, exposed to sedimentation & local sewage, or in the discharge area of municipal wastewaters. Coral microbial communities were significantly different at impacted sites: in both corals the main symbiotic taxon decreased in abundance. In contrast, opportunistic bacterial families, such as e.g. Vibrionaceae and Rhodobacteraceae, were more abundant in corals at impacted sites. In conclusion, microbial community response revealed a measurable footprint of anthropogenic impacts to coral ecosystems close to Jeddah, even though the corals appeared visually healthy. PMID:26763316

  19. Spatial distribution of marine airborne bacterial communities

    PubMed Central

    Seifried, Jasmin S; Wichels, Antje; Gerdts, Gunnar

    2015-01-01

    The spatial distribution of bacterial populations in marine bioaerosol samples was investigated during a cruise from the North Sea to the Baltic Sea via Skagerrak and Kattegat. The analysis of the sampled bacterial communities with a pyrosequencing approach revealed that the most abundant phyla were represented by the Proteobacteria (49.3%), Bacteroidetes (22.9%), Actinobacteria (16.3%), and Firmicutes (8.3%). Cyanobacteria were assigned to 1.5% of all bacterial reads. A core of 37 bacterial OTUs made up more than 75% of all bacterial sequences. The most abundant OTU was Sphingomonas sp. which comprised 17% of all bacterial sequences. The most abundant bacterial genera were attributed to distinctly different areas of origin, suggesting highly heterogeneous sources for bioaerosols of marine and coastal environments. Furthermore, the bacterial community was clearly affected by two environmental parameters – temperature as a function of wind direction and the sampling location itself. However, a comparison of the wind directions during the sampling and calculated backward trajectories underlined the need for more detailed information on environmental parameters for bioaerosol investigations. The current findings support the assumption of a bacterial core community in the atmosphere. They may be emitted from strong aerosolizing sources, probably being mixed and dispersed over long distances. PMID:25800495

  20. Spatial distribution of marine airborne bacterial communities.

    PubMed

    Seifried, Jasmin S; Wichels, Antje; Gerdts, Gunnar

    2015-06-01

    The spatial distribution of bacterial populations in marine bioaerosol samples was investigated during a cruise from the North Sea to the Baltic Sea via Skagerrak and Kattegat. The analysis of the sampled bacterial communities with a pyrosequencing approach revealed that the most abundant phyla were represented by the Proteobacteria (49.3%), Bacteroidetes (22.9%), Actinobacteria (16.3%), and Firmicutes (8.3%). Cyanobacteria were assigned to 1.5% of all bacterial reads. A core of 37 bacterial OTUs made up more than 75% of all bacterial sequences. The most abundant OTU was Sphingomonas sp. which comprised 17% of all bacterial sequences. The most abundant bacterial genera were attributed to distinctly different areas of origin, suggesting highly heterogeneous sources for bioaerosols of marine and coastal environments. Furthermore, the bacterial community was clearly affected by two environmental parameters - temperature as a function of wind direction and the sampling location itself. However, a comparison of the wind directions during the sampling and calculated backward trajectories underlined the need for more detailed information on environmental parameters for bioaerosol investigations. The current findings support the assumption of a bacterial core community in the atmosphere. They may be emitted from strong aerosolizing sources, probably being mixed and dispersed over long distances. PMID:25800495

  1. Family traditions and generations.

    PubMed

    Schneiderman, Gerald; Barrera, Maru

    2009-01-01

    Currently, traditional family values that have been passed down through generations appear to be at risk. This has significant implications for the stability and health of individuals, families, and communities. This article explores selected issues related to intergenerational transmission of family values and cultural beliefs, with particular reference to Western culture and values that are rooted in Jewish and Christian traditions. It also examines family values and parenting styles as they influence the developing perspective of children and the family's adaptation to a changing world. PMID:19752638

  2. [Family policy in Belgium].

    PubMed

    Dumon, W

    1987-01-01

    The development of family policy in Belgium since the end of World War I is described. Three periods are identified. The original objectives were to provide a basic income level for all families and to promote fertility. After World War II, measures were introduced to foster the physical and psychological health of the family, including the protection of women's rights. More recent policy trends have concentrated on family income and providing services at the family rather than the institutional level. (SUMMARY IN ENG AND FRE) PMID:12280764

  3. Impacts of different salinities on bacterial biofilm communities in fresh water.

    PubMed

    Zhang, Lei; Gao, Guang; Tang, Xiangming; Shao, Keqiang

    2014-05-01

    Natural and anthropogenic salinization continuously impacts inland aquatic ecosystems. Associated bacterial biofilms respond rapidly to environmental conditions and are potential bioindicators for changes in water quality. This study evaluates the effects of different salinity concentrations (0.3-10) on bacterial biofilms communities grown in fresh water from Lake Bosten. Bacterial communities associated with biofilms were analyzed using terminal restriction fragment length polymorphism and clone library analyses of 16S rRNA genes. Results indicated that the attached bacterial community composition (ABCC) changed over several weeks of biofilm growth, but all followed similar bacterial successional trends in the different salinity groups. Detailed analysis showed the following. (i) ABCC did not differ (P > 0.05) in the low-salinity groups (0.3-3.5), which may be related to the lower osmotic pressure and the shorter time scale (weeks) of their present habitats. (ii) There were significant differences between the oligosaline (3.5) and saline (10) groups (P < 0.05). In particular, genus Flavobacterium became dominant in attached bacterial communities in the saline groups. The higher abundance of genus Flavobacterium was possibly due to the biological and metabolic characteristics of the bacteria. (iii) Some bacterial taxa can maintain the higher abundance within attached bacteria in the entire process of biofilms growth, such as the genera Hydrogenophaga and Methyloversatilis in Betaproteobacteria and the family Sphingomonadaceae in Alphaproteobacteria. These data suggested that the bacterial successional trends within biofilms seem almost unaffected by salinity (0.3-10), but ABCC in saline groups (10) are notably changed. PMID:24802939

  4. Impact of Phanerochaete chrysosporium on the Functional Diversity of Bacterial Communities Associated with Decaying Wood

    PubMed Central

    Hervé, Vincent; Ketter, Elodie; Pierrat, Jean-Claude; Gelhaye, Eric; Frey-Klett, Pascale

    2016-01-01

    Bacteria and fungi naturally coexist in various environments including forest ecosystems. While the role of saprotrophic basidiomycetes in wood decomposition is well established, the influence of these fungi on the functional diversity of the wood-associated bacterial communities has received much less attention. Based on a microcosm experiment, we tested the hypothesis that both the presence of the white-rot fungus Phanerochaete chrysosporium and the wood, as a growth substrate, impacted the functional diversity of these bacterial communities. Microcosms containing sterile sawdust were inoculated with a microbial inoculum extracted from a forest soil, in presence or in absence of P. chrysosporium and subsequently, three enrichment steps were performed. First, bacterial strains were isolated from different microcosms previously analyzed by 16S rRNA gene-based pyrosequencing. Strains isolated from P. chrysosporium mycosphere showed less antagonism against this fungus compared to the strains isolated from the initial forest soil inoculum, suggesting a selection by the fungus of less inhibitory bacterial communities. Moreover, the presence of the fungus in wood resulted in a selection of cellulolytic and xylanolytic bacterial strains, highlighting the role of mycospheric bacteria in wood decomposition. Additionally, the proportion of siderophore-producing bacteria increased along the enrichment steps, suggesting an important role of bacteria in iron mobilization in decaying-wood. Finally, taxonomic identification of 311 bacterial isolates revealed, at the family level, strong similarities with the high-throughput sequencing data as well as with other studies in terms of taxonomic composition of the wood-associated bacterial community, highlighting that the isolated strains are representative of the wood-associated bacterial communities. PMID:26824755

  5. Impact of Phanerochaete chrysosporium on the Functional Diversity of Bacterial Communities Associated with Decaying Wood.

    PubMed

    Hervé, Vincent; Ketter, Elodie; Pierrat, Jean-Claude; Gelhaye, Eric; Frey-Klett, Pascale

    2016-01-01

    Bacteria and fungi naturally coexist in various environments including forest ecosystems. While the role of saprotrophic basidiomycetes in wood decomposition is well established, the influence of these fungi on the functional diversity of the wood-associated bacterial communities has received much less attention. Based on a microcosm experiment, we tested the hypothesis that both the presence of the white-rot fungus Phanerochaete chrysosporium and the wood, as a growth substrate, impacted the functional diversity of these bacterial communities. Microcosms containing sterile sawdust were inoculated with a microbial inoculum extracted from a forest soil, in presence or in absence of P. chrysosporium and subsequently, three enrichment steps were performed. First, bacterial strains were isolated from different microcosms previously analyzed by 16S rRNA gene-based pyrosequencing. Strains isolated from P. chrysosporium mycosphere showed less antagonism against this fungus compared to the strains isolated from the initial forest soil inoculum, suggesting a selection by the fungus of less inhibitory bacterial communities. Moreover, the presence of the fungus in wood resulted in a selection of cellulolytic and xylanolytic bacterial strains, highlighting the role of mycospheric bacteria in wood decomposition. Additionally, the proportion of siderophore-producing bacteria increased along the enrichment steps, suggesting an important role of bacteria in iron mobilization in decaying-wood. Finally, taxonomic identification of 311 bacterial isolates revealed, at the family level, strong similarities with the high-throughput sequencing data as well as with other studies in terms of taxonomic composition of the wood-associated bacterial community, highlighting that the isolated strains are representative of the wood-associated bacterial communities. PMID:26824755

  6. Effect of heavy metals on bacterial transport

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Olson, M. S.

    2010-12-01

    Adsorption of metals onto bacteria and soil takes place as stormwater runoff infiltrates into the subsurface. Changes in both bacterial surfaces and soil elemental content have been observed, and may alter the attachment of bacteria to soil surfaces. In this study, scanning electron microscopy (SEM) and Energy Dispersive X-ray Spectrometry (EDS) analyses were performed on soil samples equilibrated with synthetic stormwater amended with copper, lead and zinc. The results demonstrate the presence of copper and zinc on soil surfaces. To investigate bacterial attachment behavior, sets of batch sorption experiments were conducted on Escherichia Coli (E. coli) under different chemical conditions by varying solution compositions (nutrient solution vs synthetic stormwater). The adsorption data is best described using theoretical linear isotherms. The equilibrium coefficient (Kd) of E. coli is higher in synthetic stormwater than in nutrient solution without heavy metals. The adsorption of heavy metals onto bacterial surfaces significantly decreases their negative surface charge as determined via zeta potential measurements (-17.0±5.96mv for E. coli equilibrated with synthetic stormwater vs -21.6±5.45mv for E. coli equilibrated with nutrient solution), indicating that bacterial attachment may increase due to the attachment of metals onto bacterial surfaces and their subsequent change in surface charge. The attachment efficiency (α) of bacteria was also calculated and compared for both solution chemistries. Bacterial attachment efficiency (α) in synthetic stormwater is 0.997, which is twice as high as that in nutrient solution(α 0.465). The ratio of bacterial diameter : collector diameter suggests minimal soil straining during bacterial transport. Results suggest that the presence of metals in synthetic stormwater leads to an increase in bacterial attachment to soil surfaces. In terms of designing stormwater infiltration basins, the presence of heavy metals seems to reduce the soil depth required to achieve certain levels of bacterial removal. This study demonstrates the effect of chemical constituents in stormwater runoff on bacterial transport in the subsurface.

  7. Transfusion-associated bacterial sepsis.

    PubMed Central

    Wagner, S J; Friedman, L I; Dodd, R Y

    1994-01-01

    The incidence of sepsis caused by transfusion of bacterially contaminated blood components is similar to or less than that of transfusion-transmitted hepatitis C virus infection, yet significantly exceeds those currently estimated for transfusion-associated human immunodeficiency and hepatitis B viruses. Outcomes are serious and may be fatal. In addition, transfusion of sterile allogenic blood can have generalized immunosuppressive effects on recipients, resulting in increased susceptibility to postoperative infection. This review examines the frequency of occurrence of transfusion-associated sepsis, the organisms implicated, and potential sources of bacteria. Approaches to minimize the frequency of sepsis are discussed, including the benefits and disadvantages of altering the storage conditions for blood. In addition, the impact of high levels of bacteria on the gross characteristics of erythrocyte and platelet concentrates is described. The potentials and limitations of current tests for detecting bacteria in blood are also discussed. PMID:7923050

  8. Bacterial synthesis of biodegradable polyhydroxyalkanoates.

    PubMed

    Verlinden, R A J; Hill, D J; Kenward, M A; Williams, C D; Radecka, I

    2007-06-01

    Various bacterial species accumulate intracellular polyhydroxyalkanoates (PHAs) granules as energy and carbon reserves inside their cells. PHAs are biodegradable, environmentally friendly and biocompatible thermoplastics. Varying in toughness and flexibility, depending on their formulation, they can be used in various ways similar to many nonbiodegradable petrochemical plastics currently in use. They can be used either in pure form or as additives to oil-derived plastics such as polyethylene. However, these bioplastics are currently far more expensive than petrochemically based plastics and are therefore used mostly in applications that conventional plastics cannot perform, such as medical applications. PHAs are immunologically inert and are only slowly degraded in human tissue, which means they can be used as devices inside the body. Recent research has focused on the use of alternative substrates, novel extraction methods, genetically enhanced species and mixed cultures with a view to make PHAs more commercially attractive. PMID:17578408

  9. Magnetic microbes: Bacterial magnetite biomineralization

    DOE PAGESBeta

    Prozorov, Tanya

    2015-09-14

    Magnetotactic bacteria are a diverse group of prokaryotes with the ability to orient and migrate along the magnetic field lines in search for a preferred oxygen concentration in chemically stratified water columns and sediments. These microorganisms produce magnetosomes, the intracellular nanometer-sized magnetic crystals surrounded by a phospholipid bilayer membrane, typically organized in chains. Magnetosomes have nearly perfect crystal structures with narrow size distribution and species-specific morphologies, leading to well-defined magnetic properties. As a result, the magnetite biomineralization in these organisms is of fundamental interest to diverse disciplines, from biotechnology to astrobiology. As a result, this article highlights recent advances inmore » the understanding of the bacterial magnetite biomineralization.« less

  10. Bacterial Ice Crystal Controlling Proteins

    PubMed Central

    Lorv, Janet S. H.; Rose, David R.; Glick, Bernard R.

    2014-01-01

    Across the world, many ice active bacteria utilize ice crystal controlling proteins for aid in freezing tolerance at subzero temperatures. Ice crystal controlling proteins include both antifreeze and ice nucleation proteins. Antifreeze proteins minimize freezing damage by inhibiting growth of large ice crystals, while ice nucleation proteins induce formation of embryonic ice crystals. Although both protein classes have differing functions, these proteins use the same ice binding mechanisms. Rather than direct binding, it is probable that these protein classes create an ice surface prior to ice crystal surface adsorption. Function is differentiated by molecular size of the protein. This paper reviews the similar and different aspects of bacterial antifreeze and ice nucleation proteins, the role of these proteins in freezing tolerance, prevalence of these proteins in psychrophiles, and current mechanisms of protein-ice interactions. PMID:24579057

  11. Bacterial chemotaxis and entropy production

    PubMed Central

    Županović, Paško; Brumen, Milan; Jagodič, Marko; Juretić, Davor

    2010-01-01

    Entropy production is calculated for bacterial chemotaxis in the case of a migrating band of bacteria in a capillary tube. It is found that the speed of the migrating band is a decreasing function of the starting concentration of the metabolizable attractant. The experimentally found dependence of speed on the starting concentration of galactose, glucose and oxygen is fitted with power-law functions. It is found that the corresponding exponents lie within the theoretically predicted interval. The effect of the reproduction of bacteria on band speed is considered, too. The acceleration of the band is predicted due to the reproduction rate of bacteria. The relationship between chemotaxis, the maximum entropy production principle and the formation of self-organizing structure is discussed. PMID:20368258

  12. New pathways for bacterial polythioesters.

    PubMed

    Wübbeler, Jan Hendrik; Steinbüchel, Alexander

    2014-10-01

    Polythioesters (PTE) contain sulfur in the backbone and represent persistent biopolymers, which are produced by certain chemical procedures as well as biotechnological in vitro and in vivo techniques. Different building blocks can be incorporated, resulting in PTE with variable features that could become interesting for special purposes. Particularly, the option to produce PTE in large-scale and in accordance with the methods of white biotechnology or green chemistry is valuable due to economical potentials and public environmental consciousness. This review is focused on the synthesis of PTE by the three established bacterial production strains Ralstonia eutropha, Escherichia coli and Advenella mimigardefordensis. In addition, an overview of the in vitro production and degradation of PTE is depicted. PMID:24681198

  13. Bacterial interactions in dental biofilm.

    PubMed

    Huang, Ruijie; Li, Mingyun; Gregory, Richard L

    2011-01-01

    Biofilms are masses of microorganisms that bind to and multiply on a solid surface, typically with a fluid bathing the microbes. The microorganisms that are not attached but are free floating in an aqueous environment are termed planktonic cells. Traditionally, microbiology research has addressed results from planktonic bacterial cells. However, many recent studies have indicated that biofilms are the preferred form of growth of most microbes and particularly those of a pathogenic nature. Biofilms on animal hosts have significantly increased resistance to various antimicrobials compared to planktonic cells. These microbial communities form microcolonies that interact with each other using very sophisticated communication methods (i.e., quorum-sensing). The development of unique microbiological tools to detect and assess the various biofilms around us is a tremendously important focus of research in many laboratories. In the present review, we discuss the major biofilm mechanisms and the interactions among oral bacteria. PMID:21778817

  14. Overview perspective of bacterial resistance.

    PubMed

    Furtado, Guilherme H; Nicolau, David P

    2010-10-01

    The rapidly escalating prevalence of antimicrobial resistance is a global concern. This reduced susceptibility to currently available antimicrobial agents coupled with the progressive shortage of newly approved compounds is a worrisome situation. Major problems are encountered for a growing number of Gram-positive (i.e., Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus spp.) and Gram-negative pathogens (i.e., Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae). We provide an overview of bacterial resistance focusing on the most common pathogens responsible for infection in both the community and healthcare settings. In addition, several strategies to curb antimicrobial resistance are also discussed. It is increasingly evident that without the introduction of novel antimicrobial agents, a return to the clinical outcomes associated with the pre-antibiotic era are inevitable. PMID:20687782

  15. Bacterial Actins? An Evolutionary Perspective

    NASA Technical Reports Server (NTRS)

    Doolittle, Russell F.; York, Amanda L.

    2003-01-01

    According to the conventional wisdom, the existence of a cytoskeleton in eukaryotes and its absence in prokaryotes constitute a fundamental divide between the two domains of life. An integral part of the dogma is that a cytoskeleton enabled an early eukaryote to feed upon prokaryotes, a consequence of which was the occasional endosymbiosis and the eventual evolution of organelles. Two recent papers present compelling evidence that actin, one of the principal components of a cytoskeleton, has a homolog in Bacteria that behaves in many ways like eukaryotic actin. Sequence comparisons reveml that eukaryotic actin and the bacterial homolog (mreB protein), unlike many other proteins common to eukaryotes and Bacteria, have very different and more highly extended evolutionary histories.

  16. Bacterial Exopolysaccharides: Functionality and Prospects

    PubMed Central

    Nwodo, Uchechukwu U.; Green, Ezekiel; Okoh, Anthony I.

    2012-01-01

    Diverse structural, functional and valuable polysaccharides are synthesized by bacteria of all taxa and secreted into the external environment. These polysaccharides are referred to as exopolysaccharides and they may either be homopolymeric or heteropolymeric in composition and of diverse high molecular weights (10 to 1000 kDa). The material properties of exopolysaccharides have revolutionized the industrial and medical sectors due to their retinue of functional applications and prospects. These applications have been extensive in areas such as pharmacological, nutraceutical, functional food, cosmeceutical, herbicides and insecticides among others, while prospects includes uses as anticoagulant, antithrombotic, immunomodulation, anticancer and as bioflocculants. Due to the extensive applications of bacterial exopolysaccharides, this overview provides basic information on their physiologic and morphologic functions as well as their applications and prospects in the medical and industrial sectors. PMID:23203046

  17. Regulated proteolysis in bacterial development

    PubMed Central

    Konovalova, Anna; Søgaard-Andersen, Lotte; Kroos, Lee

    2013-01-01

    Bacteria use proteases to control three types of events temporally and spatially during processes of morphological development. These events are destruction of regulatory proteins, activation of regulatory proteins, and production of signals. While some of these events are entirely cytoplasmic, others involve intramembrane proteolysis of a substrate, trans-membrane signaling, or secretion. In some cases, multiple proteolytic events are organized into pathways, e.g., turnover of a regulatory protein activates a protease that generates a signal. We review well-studied and emerging examples, and identify recurring themes and important questions for future research. We focus primarily on paradigms learned from studies of model organisms, but we note connections to regulated proteolytic events that govern bacterial adaptation, biofilm formation and disassembly, and pathogenesis. PMID:24354618

  18. Bacterial oncogenesis in the colon

    PubMed Central

    Dejea, Christine; Wick, Elizabeth; Sears, Cynthia L

    2013-01-01

    The human colon plays host to a diverse and metabolically complex community of microorganisms. While the colonic microbiome has been suggested to contribute to the development of colorectal cancer (CRC), a definitive link has not been made. The role in which the colon microflora could contribute to the initiation and/or progression of CRC is explored in this review. Potential mechanisms of bacterial oncogenesis are presented, along with lines of evidence derived from animal models of microbially induced CRC. Particular focus is given to the oncogenic capabilities of enterotoxigenic Bacteroides fragilis. Recent progress in defining the microbiome of CRC in the human population is evaluated, and the future challenges of linking specific etiologic agents to CRC are emphasized. PMID:23534358

  19. Propulsion of a bacterial phalanx

    NASA Astrophysics Data System (ADS)

    Kessler, John O.; Cortez, Ricardo; Cisneros, Luis; Goldstein, Raymond E.; Dombrowski, Christopher

    2007-11-01

    Concentrated populations of swimming rod-shaped bacteria spontaneously form domains. Within a domain the bacteria are nearly close-packed; they all swim in the same direction. A propagating domain is a phalanx. The forward members of the domain push fluid forward, the flagella of the rear rows push fluid backwards, yielding propulsion. In the transverse direction fluid flows both in and out, but there is little net flow within a phalanx. The bacterial cell bodies and the flagella that surround them (emerging from preceding cell bodies) exert opposite stresses on the interstitial fluid. Using slender body theory, in the Reynolds number <<1 regime, a cylindrical phalanx is propelled by the flagella emerging from its rear. Dimensional analysis yields a collective propagation velocity of the same order as that of individual swimmers, even though a large population of swimmers is propelled by only a small number of bacteria, proportional to volume fraction to the 2/3 power.

  20. Antigenic Variation in Bacterial Pathogens.

    PubMed

    Palmer, Guy H; Bankhead, Troy; Seifert, H Steven

    2016-02-01

    Antigenic variation is a strategy used by a broad diversity of microbial pathogens to persist within the mammalian host. Whereas viruses make use of a minimal proofreading capacity combined with large amounts of progeny to use random mutation for variant generation, antigenically variant bacteria have evolved mechanisms which use a stable genome, which aids in protecting the fitness of the progeny. Here, three well-characterized and highly antigenically variant bacterial pathogens are discussed: Anaplasma, Borrelia, and Neisseria. These three pathogens display a variety of mechanisms used to create the structural and antigenic variation needed for immune escape and long-term persistence. Intrahost antigenic variation is the focus; however, the role of these immune escape mechanisms at the population level is also presented. PMID:26999387

  1. Family Literacy: Respecting Family Ways. ERIC Digest No. 203.

    ERIC Educational Resources Information Center

    Brown, Bettina Lankard

    Family literacy programs must acknowledge the family as the primary place of learning, and developers of family literacy programs and curricula must focus on the family unit as a whole, building upon the cultural and knowledge capital of the entire family and acknowledging gender and age power relationships within the family. Educators must…

  2. 24 CFR 982.515 - Family share: Family responsibility.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Family share: Family responsibility... Assistance Payment § 982.515 Family share: Family responsibility. (a) The family share is calculated by subtracting the amount of the housing assistance payment from the gross rent. (b) The family rent to owner...

  3. 24 CFR 982.515 - Family share: Family responsibility.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false Family share: Family responsibility... Assistance Payment § 982.515 Family share: Family responsibility. (a) The family share is calculated by subtracting the amount of the housing assistance payment from the gross rent. (b) The family rent to owner...

  4. 24 CFR 982.515 - Family share: Family responsibility.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Family share: Family responsibility... Assistance Payment § 982.515 Family share: Family responsibility. (a) The family share is calculated by subtracting the amount of the housing assistance payment from the gross rent. (b) The family rent to owner...

  5. 24 CFR 982.515 - Family share: Family responsibility.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Family share: Family responsibility... Assistance Payment § 982.515 Family share: Family responsibility. (a) The family share is calculated by subtracting the amount of the housing assistance payment from the gross rent. (b) The family rent to owner...

  6. 24 CFR 982.515 - Family share: Family responsibility.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Family share: Family responsibility... Assistance Payment § 982.515 Family share: Family responsibility. (a) The family share is calculated by subtracting the amount of the housing assistance payment from the gross rent. (b) The family rent to owner...

  7. A Simulation Tool for the Study of Symmetric Inversions in Bacterial Genomes

    NASA Astrophysics Data System (ADS)

    Dias, Ulisses; Dias, Zanoni; Setubal, João C.

    We present the tool SIB that simulates genomic inversions in bacterial chromosomes. The tool simulates symmetric inversions but allows the appearance of nonsymmetric inversions by simulating small syntenic blocks frequently observed on bacterial genome comparisons. We evaluate SIB by comparing its results to real genome alignments. We develop measures that allow quantitative comparisons between real pairwise alignments (in terms of dotplots) and simulated ones. These measures allow an evaluation of SIB in terms of dendrograms. We evaluate SIB by comparing its results to whole chromosome alignments and maximum likelihood trees for three bacterial groups (the Pseudomonadaceae family and the Xanthomonas and Shewanella genera). We demonstrate an application of SIB by using it to evaluate the ancestral genome reconstruction tool MGR.

  8. Metabolic Signatures of Bacterial Vaginosis

    PubMed Central

    Morgan, Martin T.; Fiedler, Tina L.; Djukovic, Danijel; Hoffman, Noah G.; Raftery, Daniel; Marrazzo, Jeanne M.

    2015-01-01

    ABSTRACT Bacterial vaginosis (BV) is characterized by shifts in the vaginal microbiota from Lactobacillus dominant to a microbiota with diverse anaerobic bacteria. Few studies have linked specific metabolites with bacteria found in the human vagina. Here, we report dramatic differences in metabolite compositions and concentrations associated with BV using a global metabolomics approach. We further validated important metabolites using samples from a second cohort of women and a different platform to measure metabolites. In the primary study, we compared metabolite profiles in cervicovaginal lavage fluid from 40 women with BV and 20 women without BV. Vaginal bacterial representation was determined using broad-range PCR with pyrosequencing and concentrations of bacteria by quantitative PCR. We detected 279 named biochemicals; levels of 62% of metabolites were significantly different in women with BV. Unsupervised clustering of metabolites separated women with and without BV. Women with BV have metabolite profiles marked by lower concentrations of amino acids and dipeptides, concomitant with higher levels of amino acid catabolites and polyamines. Higher levels of the signaling eicosanoid 12-hydroxyeicosatetraenoic acid (12-HETE), a biomarker for inflammation, were noted in BV. Lactobacillus crispatus and Lactobacillus jensenii exhibited similar metabolite correlation patterns, which were distinct from correlation patterns exhibited by BV-associated bacteria. Several metabolites were significantly associated with clinical signs and symptoms (Amsel criteria) used to diagnose BV, and no metabolite was associated with all four clinical criteria. BV has strong metabolic signatures across multiple metabolic pathways, and these signatures are associated with the presence and concentrations of particular bacteria. PMID:25873373

  9. Small intestinal bacterial overgrowth syndrome

    PubMed Central

    Bures, Jan; Cyrany, Jiri; Kohoutova, Darina; Förstl, Miroslav; Rejchrt, Stanislav; Kvetina, Jaroslav; Vorisek, Viktor; Kopacova, Marcela

    2010-01-01

    Human intestinal microbiota create a complex polymicrobial 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 gastrointestinal tract. There are several endogenous defence mechanisms for preventing bacterial overgrowth: gastric acid secretion, intestinal motility, intact ileo-caecal valve, immunoglobulins within intestinal secretion and bacteriostatic properties of pancreatic and biliary secretion. Aetiology of SIBO is usually complex, associated with disorders of protective antibacterial mechanisms (e.g. achlorhydria, pancreatic exocrine insufficiency, immunodeficiency syndromes), anatomical abnormalities (e.g. small intestinal obstruction, diverticula, fistulae, surgical blind loop, previous ileo-caecal resections) and/or motility disorders (e.g. scleroderma, autonomic neuropathy in diabetes mellitus, post-radiation enteropathy, small intestinal pseudo-obstruction). In some patients more than one factor may be involved. Symptoms related to SIBO are bloating, diarrhoea, malabsorption, weight loss and malnutrition. The gold standard for diagnosing SIBO is still microbial investigation of jejunal aspirates. Non-invasive hydrogen and methane breath tests are most commonly used for the diagnosis of SIBO using glucose or lactulose. Therapy for SIBO must be complex, addressing all causes, symptoms and complications, and fully individualised. It should include treatment of the underlying disease, nutritional support and cyclical gastro-intestinal selective antibiotics. Prognosis is usually serious, determined mostly by the underlying disease that led to SIBO. PMID:20572300

  10. Breakthroughs in field-scale bacterial transport

    SciTech Connect

    Balkwill, D; Chen, J; Deflaun, Mary; Dobbs, F; Dong, H; Fredrickson, Jim K. ); Fuller, M; Green, M ); Ginn, T; Griffin, T; Holben, W; Hubbard, S; Johnson, W; Long, Philip E. ); Mailloux, B; Majer, E; Mcinerney, M; Murray, Christopher J. ); Onstott, T; Phelps, T; Scheibe, Timothy D. ); Swift, D; White, D; Wobber, F

    2001-06-01

    This article summarizes a bioaugmentation research project undertaken by a DOE-sponsored, multidisciplinary research team at a field site near Oyster, Virginia. The overall purpose of the ongoing project is to evaluate the relative importance of hydrogeological and geochemical heterogeneities in controlling bacterial transpor, and to develop an approach for quantitative prediction of bacterial transport needed to design optimal bioremediation strategies.

  11. Use of Bacteriophages to control bacterial pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lytic bacteriophages can provide a natural method and an effective alternative to antibiotics to reduce bacterial pathogens in animals, foods, and other environments. Bacteriophages (phages) are viruses which infect bacterial cells and eventually kill them through lysis, and represent the most abun...

  12. Sugarbeet Cultivar Evaluation for Bacterial Root Rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial root rot of sugarbeet caused by Leuconostoc mesenteroides subsp. dextranicum is a disease problem recently described in the United States. To ameliorate the impact of bacterial root rot on sucrose loss in the field, storage piles, and factories, studies were conducted to establish an assa...

  13. Visual recovery in treated bacterial keratitis

    PubMed Central

    Srinivasan, Muthiah; Mascarenhas, Jeena; Rajaraman, Revathi; Ravindran, Meenakshi; Lalitha, Prajna; Ray, Kathryn J.; Zegans, Michael E.; Acharya, Nisha R.; Lietman, Thomas M.; Keenan, Jeremy D.

    2014-01-01

    Bacterial keratitis is a leading cause of visual impairment worldwide. However, the natural history of treated bacterial keratitis has not been well characterized. We performed a secondary analysis of the Steroids for Corneal Ulcers Trial (SCUT; clinicaltrials.gov #NCT00324168) to better characterize the rate of visual acuity improvement after successful antimicrobial treatment. PMID:24612976

  14. Periarrest intestinal bacterial translocation and resuscitation outcome.

    PubMed

    Chalkias, Athanasios; Scheetz, Marc H; Gulati, Anil; Xanthos, Theodoros

    2016-02-01

    During the periarrest period, intestinal ischemia may result in barrier dysfunction and bacterial translocation, which has clear mechanistic links to inflammation and cascade stimulation, especially in patients who are treated with therapeutic hypothermia. Despite optimal management, periarrest bacterial translocation may worsen the outcome of cardiac arrest victims. PMID:26481507

  15. Cellular damage in bacterial meningitis: an interplay of bacterial and host driven toxicity.

    PubMed

    Weber, Joerg R; Tuomanen, Elaine I

    2007-03-01

    Bacterial meningitis is still an important infectious disease causing death and disability. Invasive bacterial infections of the CNS generate some of the most powerful inflammatory responses known in medicine. Although the components of bacterial cell surfaces are now chemically defined in exquisite detail and the interaction with several receptor pathways has been discovered, it is only very recently that studies combining these advanced biochemical and cell biological tools have been done. Additional to the immunological response direct bacterial toxicity has been identified as an important contributor to neuronal damage. A detailed understanding of the complex interaction of bacterial toxicity and host response may generate opportunities for innovative and specific neuroprotective therapies. PMID:17210186

  16. Continuous bacterial coal desulfurization employing Thiobacillus ferrooxidans

    SciTech Connect

    Myerson, A.S.; Kline, P.C.

    1984-01-01

    The leaching of pyrite sulfur from coal employing Thiobacillus ferrooxidans was studied in a continuous stirred tank reactor at a variety of dilution rates (0.02-0.11 h/sup -1/) and coal surface areas (0.25-1.0 m/sup 2//mL). The bacterial leaching rate was found to increase with increasing dilution rate. The bacterial concentration on the coal surface was related to the bacterial concentration in solution by a irreversible second-order (of the second kind) kinetic equation. The concentration of bacteria on the coal in all experiments was the concentration at saturation. Step changes in the coal concentration were observed to result in dramatic declines in bacterial concentration in solution. A bacterial mass balance model was employed to calculate the specific growth rate on the solid which was observed to increase with increasing dilution rate.

  17. Bacterial Vaginosis: An Overview for 2009

    PubMed Central

    Livengood, Charles H

    2009-01-01

    Bacterial vaginosis has been appreciated as a unique clinical entity for well over 50 years. Its essential manifestations are well established: a loss of the normal bacterial population of the vagina and their replacement by other species. Investigations into this condition have led to a better understanding of its prevalence and epidemiology. Microbiologic and biochemical studies have exposed the remarkably complex pathophysiologic events that occur with bacterial vaginosis. Several major morbidities accompany this condition. Advances have been made in treatment, including the recent availability of a new therapeutic agent, tinidazole. However, the root cause of the condition is elusive, and as a result managing bacterial vaginosis and its complications is unsatisfactory; moreover, data suggest that therapy now is less successful than in the past. This article brings together the current fund of knowledge about bacterial vaginosis in a way that offers clinicians a realistic view of our capabilities and concerns. PMID:19399292

  18. Immunity to bacterial infection in the chicken.

    PubMed

    Wigley, Paul

    2013-11-01

    Bacterial infections remain important to the poultry industry both in terms of animal and public health, the latter due to the importance of poultry as a source of foodborne bacterial zoonoses such as Salmonella and Campylobacter. As such, much focus of research to the immune response to bacterial infection has been to Salmonella. In this review we will focus on how research on avian salmonellosis has developed our understanding of immunity to bacteria in the chicken from understanding the role of TLRs in recognition of bacterial pathogens, through the role of heterophils, macrophages and γδ lymphocytes in innate immunity and activation of adaptive responses to the role of cellular and humoral immunity in immune clearance and protection. What is known of the immune response to other bacterial infections and in particular infections that have emerged recently as major problems in poultry production including Campylobacter jejuni, Avian Pathogenic Escherichia coli, Ornithobacterium rhinotracheale and Clostridium perfringens are discussed. PMID:23648643

  19. The potential use of bacterial community succession in forensics as described by high throughput metagenomic sequencing.

    PubMed

    Pechal, Jennifer L; Crippen, Tawni L; Benbow, M Eric; Tarone, Aaron M; Dowd, Scot; Tomberlin, Jeffery K

    2014-01-01

    Decomposition studies of vertebrate remains primarily focus on data that can be seen with the naked eye, such as arthropod or vertebrate scavenger activity, with little regard for what might be occurring with the microorganism community. Here, we discuss the necrobiome, or community of organisms associated with the decomposition of remains, specifically, the "epinecrotic" bacterial community succession throughout decomposition of vertebrate carrion. Pyrosequencing was used to (1) detect and identify bacterial community abundance patterns that described discrete time points of the decomposition process and (2) identify bacterial taxa important for estimating physiological time, a time-temperature metric that is often commensurate with minimum post-mortem interval estimates, via thermal summation models. There were significant bacterial community structure differences in taxon richness and relative abundance patterns through the decomposition process at both phylum and family taxonomic classification levels. We found a significant negative linear relationship for overall phylum and family taxon richness as decomposition progressed. Additionally, we developed a statistical model using high throughput sequencing data of epinecrotic bacterial communities on vertebrate remains that explained 94.4 % of the time since placement of remains in the field, which was within 2-3 h of death. These bacteria taxa are potentially useful for estimating the minimum post-mortem interval. Lastly, we provide a new framework and standard operating procedure of how this novel approach of using high throughput metagenomic sequencing has remarkable potential as a new forensic tool. Documenting and identifying differences in bacterial communities is key to advancing knowledge of the carrion necrobiome and its applicability in forensic science. PMID:23749255

  20. Advancing family psychology.

    PubMed

    Fiese, Barbara H

    2016-02-01

    To realize the broad and complex nature of the field of family psychology, I have slightly revised the mission statement of the Journal of Family Psychology (JFP) to capture contemporary scholarship in family psychology and to advance systems perspectives in this top-tier scientific journal. Over the next 6 years, I hope that authors will consider JFP as an outlet for their best work in the following areas: (1) JFP addresses societal challenges faced by families today; (2) JFP publishes important studies on what makes couple and family relationships work; (3) JFP is a leader in publishing reports that use cutting-edge sophisticated approaches to research design and data analysis; and (4) JFP imparts knowledge about effective therapy and prevention programs relevant to couples and families. The journal is also expanding its publicaton rate to eight issues per year. (PsycINFO Database Record PMID:26845635

  1. Oral bacterial DNA findings in pericardial fluid

    PubMed Central

    Louhelainen, Anne-Mari; Aho, Joonas; Tuomisto, Sari; Aittoniemi, Janne; Vuento, Risto; Karhunen, Pekka J.; Pessi, Tanja

    2014-01-01

    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. PMID:25412607

  2. Evidence of major genes affecting bacterial cold water disease resistance in rainbow trout using Bayesian methods of complex segregation analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. We previously detected genetic variation for BCWD resistance in our rainbow trout population, and a family-based selection program to improve resistance was initiated at the NCCCWA in 2005. The main objec...

  3. Tunicamycins: translocase-I inhibitors that target bacterial cell wall and mammalian N-glycoproteins. The potential for selective inhibitors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tunicamycins are a heterologous family of nucleoside antibiotics that target the biosynthesis of bacterial peptidoglycan and eukaryotic N-glycoproteins. The mechanism of action is known, with the tunicamycin-Mg2+ complex established as a transition state analog for hexosamine-1-phosphate: prenol pho...

  4. Evidence of major genes affecting resistance to bacterial cold water disease in rainbow trout using Bayesian methods of segregation analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial cold water disease (BCWD) causes significant economic loss in salmonid aquaculture. We previously detected genetic variation for BCWD resistance in our rainbow trout population, and a family-based selection program to improve resistance was initiated at the National Center for Cool and Col...

  5. Comparative Analysis of Lacinutrix Genomes and Their Association with Bacterial Habitat

    PubMed Central

    Lee, Yung Mi; Kim, Mi-Kyeong; Ahn, Do Hwan; Kim, Han-Woo; Park, Hyun; Shin, Seung Chul

    2016-01-01

    The genus Lacinutrix, which belongs to the family Flavobacteriaceae, consists of seven bacterial species that were mainly isolated from marine life and sediments. As most bacteria in the family Flavobacteriaceae favor aerobic conditions, the seven bacterial species in the genus Lacinutrix also showed aerobic growth. We selected four monophyletic bacterial species living in a polar environment. Two of these species were isolated from sediment and two types were isolated from algae. In a comparative analysis, we investigated how these different environments were related to genomic features of these four species in the genus Lacinutrix. We found that the gene sets for glycolysis, the Krebs cycle, and oxidative phosphorylation were conserved in these four type strains. However, the presence of nitrous oxide reductase for denitrification and the absence of essential components related to thiamin biosynthesis for aerobic respiration were only found in isolates from sediment. Elevated bacterial metabolism on the surface of marine sediments might limit the oxygen penetration into sediment, and such an environment might affect the genomes of bacteria isolated from these habitats. PMID:26882010

  6. Comparative Analysis of Lacinutrix Genomes and Their Association with Bacterial Habitat.

    PubMed

    Lee, Yung Mi; Kim, Mi-Kyeong; Ahn, Do Hwan; Kim, Han-Woo; Park, Hyun; Shin, Seung Chul

    2016-01-01

    The genus Lacinutrix, which belongs to the family Flavobacteriaceae, consists of seven bacterial species that were mainly isolated from marine life and sediments. As most bacteria in the family Flavobacteriaceae favor aerobic conditions, the seven bacterial species in the genus Lacinutrix also showed aerobic growth. We selected four monophyletic bacterial species living in a polar environment. Two of these species were isolated from sediment and two types were isolated from algae. In a comparative analysis, we investigated how these different environments were related to genomic features of these four species in the genus Lacinutrix. We found that the gene sets for glycolysis, the Krebs cycle, and oxidative phosphorylation were conserved in these four type strains. However, the presence of nitrous oxide reductase for denitrification and the absence of essential components related to thiamin biosynthesis for aerobic respiration were only found in isolates from sediment. Elevated bacterial metabolism on the surface of marine sediments might limit the oxygen penetration into sediment, and such an environment might affect the genomes of bacteria isolated from these habitats. PMID:26882010

  7. Shigella IpaH Family Effectors as a Versatile Model for Studying Pathogenic Bacteria.

    PubMed

    Ashida, Hiroshi; Sasakawa, Chihiro

    2015-01-01

    Shigella spp. are highly adapted human pathogens that cause bacillary dysentery (shigellosis). Via the type III secretion system (T3SS), Shigella deliver a subset of virulence proteins (effectors) that are responsible for pathogenesis, with functions including pyroptosis, invasion of the epithelial cells, intracellular survival, and evasion of host immune responses. Intriguingly, T3SS effector activity and strategies are not unique to Shigella, but are shared by many other bacterial pathogens, including Salmonella, Yersinia, and enteropathogenic Escherichia coli (EPEC). Therefore, studying Shigella T3SS effectors will not only improve our understanding of bacterial infection systems, but also provide a molecular basis for developing live bacterial vaccines and antibacterial drugs. One of Shigella T3SS effectors, IpaH family proteins, which have E3 ubiquitin ligase activity and are widely conserved among other bacterial pathogens, are very relevant because they promote bacterial survival by triggering cell death and modulating the host immune responses. Here, we describe selected examples of Shigella pathogenesis, with particular emphasis on the roles of IpaH family effectors, which shed new light on bacterial survival strategies and provide clues about how to overcome bacterial infections. PMID:26779450

  8. Shigella IpaH Family Effectors as a Versatile Model for Studying Pathogenic Bacteria

    PubMed Central

    Ashida, Hiroshi; Sasakawa, Chihiro

    2016-01-01

    Shigella spp. are highly adapted human pathogens that cause bacillary dysentery (shigellosis). Via the type III secretion system (T3SS), Shigella deliver a subset of virulence proteins (effectors) that are responsible for pathogenesis, with functions including pyroptosis, invasion of the epithelial cells, intracellular survival, and evasion of host immune responses. Intriguingly, T3SS effector activity and strategies are not unique to Shigella, but are shared by many other bacterial pathogens, including Salmonella, Yersinia, and enteropathogenic Escherichia coli (EPEC). Therefore, studying Shigella T3SS effectors will not only improve our understanding of bacterial infection systems, but also provide a molecular basis for developing live bacterial vaccines and antibacterial drugs. One of Shigella T3SS effectors, IpaH family proteins, which have E3 ubiquitin ligase activity and are widely conserved among other bacterial pathogens, are very relevant because they promote bacterial survival by triggering cell death and modulating the host immune responses. Here, we describe selected examples of Shigella pathogenesis, with particular emphasis on the roles of IpaH family effectors, which shed new light on bacterial survival strategies and provide clues about how to overcome bacterial infections. PMID:26779450

  9. The family lecture.

    PubMed

    Rose, Nancy E

    2002-10-01

    SUMMARY This paper describes a lecture about my extended family, in which I discuss a variety of configurations consisting of lesbian, gay, and bisexual adults, and our children. It raises an array of issues, including alternative insemination, biological and nonbiological parentage, donors and birthmothers, adoption, co-parenting and blended families, significant others, and gay marriage and domestic partnership. It helps many students obtain both a more expansive sense of family and adeeper understanding of homophobia. PMID:24804601

  10. State of family planning.

    PubMed

    Schreiber, Courtney A; Traxler, Sarah

    2015-06-01

    Family planning and reproductive health services are uniquely impacted by policy and politics in the United States. Recent years have witnessed an unprecedented number of abortion restrictions, and research funding has decreased in related areas. Despite this, both the science and the implementation of improved family planning and abortion methods have progressed in the past decade. This article reviews the current state of family planning, as well as technologies and patient care opportunities for the future. PMID:25860324

  11. Asteroid family ages

    NASA Astrophysics Data System (ADS)

    Spoto, Federica; Milani, Andrea; Knežević, Zoran

    2015-09-01

    A new family classification, based on a catalog of proper elements with ∼384,000 numbered asteroids and on new methods is available. For the 45 dynamical families with >250 members identified in this classification, we present an attempt to obtain statistically significant ages: we succeeded in computing ages for 37 collisional families. We used a rigorous method, including a least squares fit of the two sides of a V-shape plot in the proper semimajor axis, inverse diameter plane to determine the corresponding slopes, an advanced error model for the uncertainties of asteroid diameters, an iterative outlier rejection scheme and quality control. The best available Yarkovsky measurement was used to estimate a calibration of the Yarkovsky effect for each family. The results are presented separately for the families originated in fragmentation or cratering events, for the young, compact families and for the truncated, one-sided families. For all the computed ages the corresponding uncertainties are provided, and the results are discussed and compared with the literature. The ages of several families have been estimated for the first time, in other cases the accuracy has been improved. We have been quite successful in computing ages for old families, we have significant results for both young and ancient, while we have little, if any, evidence for primordial families. We found 2 cases where two separate dynamical families form together a single V-shape with compatible slopes, thus indicating a single collisional event. We have also found 3 examples of dynamical families containing multiple collisional families, plus a dubious case: for these we have obtained discordant slopes for the two sides of the V-shape, resulting in distinct ages. We have found 2 cases of families containing a conspicuous subfamily, such that it is possible to measure the slope of a distinct V-shape, thus the age of the secondary collision. We also provide data on the central gaps appearing in some families. The ages computed in this paper are obtained with a single and uniform methodology, thus the ages of different families can be compared, providing a first example of collisional chronology of the asteroid main belt.

  12. Bacterial type IV secretion: conjugation systems adapted to deliver effector molecules to host cells

    PubMed Central

    Christie, Peter J.; Vogel, Joseph P.

    2016-01-01

    Several bacterial pathogens utilize conjugation machines to export effector molecules during infection. Such systems are members of the type IV or ‘adapted conjugation’ secretion family. The prototypical type IV system is the Agrobacterium tumefaciens T-DNA transfer machine, which delivers oncogenic nucleoprotein particles to plant cells. Other pathogens, including Bordetella pertussis, Legionella pneumophila, Brucella spp. and Helicobacter pylori, use type IV machines to export effector proteins to the extracellular milieu or the mammalian cell cytosol. PMID:10920394

  13. Strengthening Families: Exploring the Impacts of Family Camp Experiences on Family Functioning and Parenting

    ERIC Educational Resources Information Center

    Garst, Barry A.; Baughman, Sarah; Franz, Nancy K.; Seidel, Richard W.

    2013-01-01

    Research suggests that family camp experiences can enhance family relationships. Families often participate in family camp experiences for a vacation, as part of a therapeutic and/or intervention strategy, or to gain general enrichment or engagement. To better understand the impacts of family camp experiences on family functioning, a mixed-methods

  14. Strengthening Families: Exploring the Impacts of Family Camp Experiences on Family Functioning and Parenting

    ERIC Educational Resources Information Center

    Garst, Barry A.; Baughman, Sarah; Franz, Nancy K.; Seidel, Richard W.

    2013-01-01

    Research suggests that family camp experiences can enhance family relationships. Families often participate in family camp experiences for a vacation, as part of a therapeutic and/or intervention strategy, or to gain general enrichment or engagement. To better understand the impacts of family camp experiences on family functioning, a mixed-methods…

  15. Interplay of heritage and habitat in the distribution of bacterial signal transduction systems

    PubMed Central

    Galperin, Michael Y.; Higdon, Roger; Kolker, Eugene

    2011-01-01

    Comparative analysis of the complete genome sequences from a variety of poorly studied organisms aims at predicting ecological and behavioral properties of these organisms and help in characterizing their habitats. This task requires finding appropriate descriptors that could be correlated with the core traits of each system and would allow meaningful comparisons. Using the relatively simple bacterial models, first attempts have been made to introduce suitable metrics to describe the complexity of organism’s signaling machinery, which included introducing the “bacterial IQ” score. Here, we use an updated census of prokaryotic signal transduction systems to improve this parameter and evaluate its consistency within selected bacterial phyla. We also introduce a more elaborate descriptor, a set of profiles of relative abundance of members of each family of signal transduction proteins encoded in each genome. We show that these family profiles are well conserved within each genus and are often consistent within families of bacteria. Thus, they reflect evolutionary relationships between organisms as well as individual adaptations of each organism to its specific ecological niche. PMID:20237650

  16. Fatal familial insomnia: a seventh family.

    PubMed

    Silburn, P; Cervenáková, L; Varghese, P; Tannenberg, A; Brown, P; Boyle, R

    1996-11-01

    A 60-year-old woman with a typical history of fatal familial insomnia (FFI) had FFI proven by histologic examination and molecular testing. Her son, who died at the age of 20 in 1978, had a rapidly progressive dementing illness without reported insomnia. He carried the characteristic mutation for FFI and is the youngest patient reported with this condition. PMID:8909452

  17. Pathogenesis and pathophysiology of bacterial meningitis.

    PubMed Central

    Tunkel, A R; Scheld, W M

    1993-01-01

    Bacterial meningitis remains a disease with associated unacceptable morbidity and mortality rates despite the availability of effective bactericidal antimicrobial therapy. Through the use of experimental animal models of infection, a great deal of information has been gleaned concerning the pathogenic and pathophysiologic mechanisms operable in bacterial meningitis. Most cases of bacterial meningitis begin with host acquisition of a new organism by nasopharyngeal colonization followed by systemic invasion and development of a high-grade bacteremia. Bacterial encapsulation contributes to this bacteremia by inhibiting neutrophil phagocytosis and resisting classic complement-mediated bactericidal activity. Central nervous system invasion then occurs, although the exact site of bacterial traversal into the central nervous system is unknown. By production and/or release of virulence factors into and stimulation of formation of inflammatory cytokines within the central nervous system, meningeal pathogens increase permeability of the blood-brain barrier, thus allowing protein and neutrophils to move into the subarachnoid space. There is then an intense subarachnoid space inflammatory response, which leads to many of the pathophysiologic consequences of bacterial meningitis, including cerebral edema and increased intracranial pressure. Attenuation of this inflammatory response with adjunctive dexamethasone therapy is associated with reduced concentrations of tumor necrosis factor in the cerebrospinal fluid, with diminished cerebrospinal fluid leukocytosis, and perhaps with improvement of morbidity, as demonstrated in recent clinical trials. Further information on the pathogenesis and pathophysiology of bacterial meningitis should lead to the development of more innovative treatment and/or preventive strategies for this disorder. Images PMID:8472245

  18. Bacterial Secretion Systems – An overview

    PubMed Central

    Green, Erin R.; Mecsas, Joan

    2015-01-01

    CHAPTER SUMMARY Bacterial pathogens utilize a multitude of methods to invade mammalian hosts, damage tissue sites, and thwart the immune system from responding. One essential component of these strategies for many bacterial pathogens is the secretion of proteins across phospholipid membranes. Secreted proteins can play many roles in promoting bacterial virulence, from enhancing attachment to eukaryotic cells, to scavenging resources in an environmental niche, to directly intoxicating target cells and disrupting their functions. Many pathogens use dedicated protein secretion systems to secrete virulence factors from the cytosol of the bacteria into host cells or the host environment. In general, bacterial protein secretion apparatuses can be divided into different classes, based on their structures, functions, and specificity. Some systems are conserved in all classes of bacteria and secrete a broad array of substrates, while others are only found in a small number of bacterial species and/or are specific to only one or a few proteins. In this chapter, we review the canonical features of several common bacterial protein secretion systems, as well as their roles in promoting the virulence of bacterial pathogens. Additionally, we address recent findings that indicate that the innate immune system of the host can detect and respond to the presence of protein secretion systems during mammalian infection. PMID:26999395

  19. Transfer of intestinal bacterial components to mammary secretions in the cow

    PubMed Central

    Young, Wayne; Hine, Brad C.; Wallace, Olivia A.M.; Callaghan, Megan

    2015-01-01

    Results from large multicentre epidemiological studies suggest an association between the consumption of raw milk and a reduced incidence of allergy and asthma in children. Although the underlying mechanisms for this association are yet to be confirmed, researchers have investigated whether bacteria or bacterial components that naturally occur in cow’s milk are responsible for modulating the immune system to reduce the risk of allergic diseases. Previous research in human and mice suggests that bacterial components derived from the maternal intestine are transported to breast milk through the bloodstream. The aim of our study was to assess whether a similar mechanism of bacterial trafficking could occur in the cow. Through the application of culture-independent methodology, we investigated the microbial composition and diversity of milk, blood and feces of healthy lactating cows. We found that a small number of bacterial OTUs belonging to the genera Ruminococcus and Bifidobacterium, and the Peptostreptococcaceae family were present in all three samples from the same individual animals. Although these results do not confirm the hypothesis that trafficking of intestinal bacteria into mammary secretions does occur in the cow, they support the existence of an endogenous entero-mammary pathway for some bacterial components during lactation in the cow. Further research is required to define the specific mechanisms by which gut bacteria are transported into the mammary gland of the cow, and the health implications of such bacteria being present in milk. PMID:25922791

  20. Bacterial diversity and composition in the fluid of pitcher plants of the genus Nepenthes.

    PubMed

    Takeuchi, Yayoi; Chaffron, Samuel; Salcher, Michaela M; Shimizu-Inatsugi, Rie; Kobayashi, Masaki J; Diway, Bibian; von Mering, Christian; Pernthaler, Jakob; Shimizu, Kentaro K

    2015-07-01

    Pitchers are modified leaves used by carnivorous plants for trapping prey. Their fluids contain digestive enzymes from the plant and they harbor abundant microbes. In this study, the diversity of bacterial communities was assessed in Nepenthes pitcher fluids and the composition of the bacterial community was compared to that in other environments, including the phyllosphere of Arabidopsis, animal guts and another pitcher plant, Sarracenia. Diversity was measured by 454 pyrosequencing of 16S rRNA gene amplicons. A total of 232,823 sequences were obtained after chimera and singleton removal that clustered into 3260 distinct operational taxonomic units (OTUs) (3% dissimilarity), which were taxonomically distributed over 17 phyla, 25 classes, 45 orders, 100 families, and 195 genera. Pyrosequencing and fluorescence in situ hybridization yielded similar estimates of community composition. Most pitchers contained high proportions of unique OTUs, and only 22 OTUs (<0.6%) were shared by ≥14/16 samples, suggesting a unique bacterial assemblage in each pitcher at the OTU level. Diversity analysis at the class level revealed that the bacterial communities of both opened and unopened pitchers were most similar to that of Sarracenia and to that in the phyllosphere. Therefore, the bacterial community in pitchers may be formed by environmental filtering and/or by phyllosphere bacteria. PMID:26138047

  1. Early colonizers of unoccupied habitats represent a minority of the soil bacterial community.

    PubMed

    Wolf, Alexandra B; Rudnick, Max-Bernhard; de Boer, Wietse; Kowalchuk, George A

    2015-05-01

    In order to understand (re-)colonization of microhabitats and bacterial succession in soil, it is important to understand which members of soil bacterial communities are most motile in the porous soil matrix. To address this issue, we carried out a series of experiments in sterilized soil microcosms. Using two different model strains, Pseudomonas fluorescens strain Pf0-1 and Collimonas fungivorans strain Ter331, we first determined the influence of nutrient availability on bacterial expansion rates. Based on these results, we then conducted similar microcosm experiments to examine microbial mobility within natural soil bacterial communities under a single nutrient regime. The expansion of bacterial populations within the community was assayed by quantitative PCR and pyrosequencing of 16S rRNA gene fragments. We observed that only a relatively small subset of the total community was able to expand to an appreciable distance (more than 2 cm) within 48 h, with the genera Undibacterium, Pseudomonas and Massilia and especially the family Enterobacteriaceae dominating the communities more distant from the point of inoculation. These results suggest that (re-)colonization of open habitats in soil may be dominated by a few rapidly moving species, which may have important consequences for microbial succession. PMID:25778508

  2. Diversity of Bacterial Communities on Four Frequently Used Surfaces in a Large Brazilian Teaching Hospital

    PubMed Central

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

    2016-01-01

    Frequently used hand-touch surfaces in hospital settings have been implicated as a vehicle of microbial transmission. In this study, we aimed to investigate the overall bacterial population on four frequently used surfaces using a culture-independent Illumina massively parallel sequencing approach of the 16S rRNA genes. Surface samples were collected from four sites, namely elevator buttons (EB), bank machine keyboard buttons (BMKB), restroom surfaces, and the employee biometric time clock system (EBTCS), in a large public and teaching hospital in São Paulo. Taxonomical composition revealed the abundance of Firmicutes phyla, followed by Actinobacteria and Proteobacteria, with a total of 926 bacterial families and 2832 bacterial genera. Moreover, our analysis revealed the presence of some potential pathogenic bacterial genera, including Salmonella enterica, Klebsiella pneumoniae, and Staphylococcus aureus. The presence of these pathogens in frequently used surfaces enhances the risk of exposure to any susceptible individuals. Some of the factors that may contribute to the richness of bacterial diversity on these surfaces are poor personal hygiene and ineffective routine schedules of cleaning, sanitizing, and disinfecting. Strict standards of infection control in hospitals and increased public education about hand hygiene are recommended to decrease the risk of transmission in hospitals among patients. PMID:26805866

  3. Diversity of Bacterial Communities on Four Frequently Used Surfaces in a Large Brazilian Teaching Hospital.

    PubMed

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

    2016-01-01

    Frequently used hand-touch surfaces in hospital settings have been implicated as a vehicle of microbial transmission. In this study, we aimed to investigate the overall bacterial population on four frequently used surfaces using a culture-independent Illumina massively parallel sequencing approach of the 16S rRNA genes. Surface samples were collected from four sites, namely elevator buttons (EB), bank machine keyboard buttons (BMKB), restroom surfaces, and the employee biometric time clock system (EBTCS), in a large public and teaching hospital in São Paulo. Taxonomical composition revealed the abundance of Firmicutes phyla, followed by Actinobacteria and Proteobacteria, with a total of 926 bacterial families and 2832 bacterial genera. Moreover, our analysis revealed the presence of some potential pathogenic bacterial genera, including Salmonella enterica, Klebsiella pneumoniae, and Staphylococcus aureus. The presence of these pathogens in frequently used surfaces enhances the risk of exposure to any susceptible individuals. Some of the factors that may contribute to the richness of bacterial diversity on these surfaces are poor personal hygiene and ineffective routine schedules of cleaning, sanitizing, and disinfecting. Strict standards of infection control in hospitals and increased public education about hand hygiene are recommended to decrease the risk of transmission in hospitals among patients. PMID:26805866

  4. Effect of Dietary Protein Levels on Composition of Odorous Compounds and Bacterial Ecology in Pig Manure

    PubMed Central

    Cho, Sungback; Hwang, Okhwa; Park, Sungkwon

    2015-01-01

    This study was performed to investigate the effect of different levels of dietary crude protein (CP) on composition of odorous compounds and bacterial communities in pig manure. A total of 48 male pigs (average initial body weight 45 kg) fed diets containing three levels of dietary CP (20%, 17.5%, and 15%) and their slurry samples were collected from the pits under the floor every week for one month. Changes in composition of odorous compounds and bacterial communities were analyzed by gas chromatography and 454 FLX titanium pyrosequencing systems, respectively. Levels of phenols, indoles, short chain fatty acid and branched chain fatty acid were lowest (p<0.05) in CP 15% group among three CP levels. Relative abundance of Bacteroidetes phylum and bacterial genera including Leuconostoc, Bacillus, Atopostipes, Peptonphilus, Ruminococcaceae_uc, Bacteroides, and Pseudomonas was lower (p<0.05) in CP 15% than in CP 20% group. There was a positive correlation (p<0.05) between odorous compounds and bacterial genera: phenol, indole, iso-butyric acid, and iso-valeric acid with Atopostipes, p-cresol and skatole with Bacteroides, acetic acid and butyric acid with AM982595_g of Porphyromonadaceae family, and propionic acid with Tissierella. Taken together, administration of 15% CP showed less production of odorous compounds than 20% CP group and this result might be associated with the changes in bacterial communities especially whose roles in protein metabolism. PMID:26194219

  5. NAIP proteins are required for cytosolic detection of specific bacterial ligands in vivo.

    PubMed

    Rauch, Isabella; Tenthorey, Jeannette L; Nichols, Randilea D; Al Moussawi, Khatoun; Kang, James J; Kang, Chulho; Kazmierczak, Barbara I; Vance, Russell E

    2016-05-01

    NLRs (nucleotide-binding domain [NBD] leucine-rich repeat [LRR]-containing proteins) exhibit diverse functions in innate and adaptive immunity. NAIPs (NLR family, apoptosis inhibitory proteins) are NLRs that appear to function as cytosolic immunoreceptors for specific bacterial proteins, including flagellin and the inner rod and needle proteins of bacterial type III secretion systems (T3SSs). Despite strong biochemical evidence implicating NAIPs in specific detection of bacterial ligands, genetic evidence has been lacking. Here we report the use of CRISPR/Cas9 to generate Naip1(-/-) and Naip2(-/-) mice, as well as Naip1-6(Δ/Δ) mice lacking all functional Naip genes. By challenging Naip1(-/-) or Naip2(-/-) mice with specific bacterial ligands in vivo, we demonstrate that Naip1 is uniquely required to detect T3SS needle protein and Naip2 is uniquely required to detect T3SS inner rod protein, but neither Naip1 nor Naip2 is required for detection of flagellin. Previously generated Naip5(-/-) mice retain some residual responsiveness to flagellin in vivo, whereas Naip1-6(Δ/Δ) mice fail to respond to cytosolic flagellin, consistent with previous biochemical data implicating NAIP6 in flagellin detection. Our results provide genetic evidence that specific NAIP proteins function to detect specific bacterial proteins in vivo. PMID:27045008

  6. Transfer of intestinal bacterial components to mammary secretions in the cow.

    PubMed

    Young, Wayne; Hine, Brad C; Wallace, Olivia A M; Callaghan, Megan; Bibiloni, Rodrigo

    2015-01-01

    Results from large multicentre epidemiological studies suggest an association between the consumption of raw milk and a reduced incidence of allergy and asthma in children. Although the underlying mechanisms for this association are yet to be confirmed, researchers have investigated whether bacteria or bacterial components that naturally occur in cow's milk are responsible for modulating the immune system to reduce the risk of allergic diseases. Previous research in human and mice suggests that bacterial components derived from the maternal intestine are transported to breast milk through the bloodstream. The aim of our study was to assess whether a similar mechanism of bacterial trafficking could occur in the cow. Through the application of culture-independent methodology, we investigated the microbial composition and diversity of milk, blood and feces of healthy lactating cows. We found that a small number of bacterial OTUs belonging to the genera Ruminococcus and Bifidobacterium, and the Peptostreptococcaceae family were present in all three samples from the same individual animals. Although these results do not confirm the hypothesis that trafficking of intestinal bacteria into mammary secretions does occur in the cow, they support the existence of an endogenous entero-mammary pathway for some bacterial components during lactation in the cow. Further research is required to define the specific mechanisms by which gut bacteria are transported into the mammary gland of the cow, and the health implications of such bacteria being present in milk. PMID:25922791

  7. The bacterial species dilemma and the genomic–phylogenetic species concept

    PubMed Central

    Staley, James T

    2006-01-01

    The number of species of Bacteria and Archaea (ca 5000) is surprisingly small considering their early evolution, genetic diversity and residence in all ecosystems. The bacterial species definition accounts in part for the small number of named species. The primary procedures required to identify new species of Bacteria and Archaea are DNA–DNA hybridization and phenotypic characterization. Recently, 16S rRNA gene sequencing and phylogenetic analysis have been applied to bacterial taxonomy. Although 16S phylogeny is arguably excellent for classification of Bacteria and Archaea from the Domain level down to the family or genus, it lacks resolution below that level. Newer approaches, including multilocus sequence analysis, and genome sequence and microarray analyses, promise to provide necessary information to better understand bacterial speciation. Indeed, recent data using these approaches, while meagre, support the view that speciation processes may occur at the subspecies level within ecological niches (ecovars) and owing to biogeography (geovars). A major dilemma for bacterial taxonomists is how to incorporate this new information into the present hierarchical system for classification of Bacteria and Archaea without causing undesirable confusion and contention. This author proposes the genomic–phylogenetic species concept (GPSC) for the taxonomy of prokaryotes. The aim is twofold. First, the GPSC would provide a conceptual and testable framework for bacterial taxonomy. Second, the GPSC would replace the burdensome requirement for DNA hybridization presently needed to describe new species. Furthermore, the GPSC is consistent with the present treatment at higher taxonomic levels. PMID:17062409

  8. Conformational Plasticity and Ligand Binding of Bacterial Monoacylglycerol Lipase*

    PubMed Central

    Rengachari, Srinivasan; Aschauer, Philipp; Schittmayer, Matthias; Mayer, Nicole; Gruber, Karl; Breinbauer, Rolf; Birner-Gruenberger, Ruth; Dreveny, Ingrid; Oberer, Monika

    2013-01-01

    Monoacylglycerol lipases (MGLs) play an important role in lipid catabolism across all kingdoms of life by catalyzing the release of free fatty acids from monoacylglycerols. The three-dimensional structures of human and a bacterial MGL were determined only recently as the first members of this lipase family. In addition to the α/β-hydrolase core, they showed unexpected structural similarities even in the cap region. Nevertheless, the structural basis for substrate binding and conformational changes of MGLs is poorly understood. Here, we present a comprehensive study of five crystal structures of MGL from Bacillus sp. H257 in its free form and in complex with different substrate analogs and the natural substrate 1-lauroylglycerol. The occurrence of different conformations reveals a high degree of conformational plasticity of the cap region. We identify a specific residue, Ile-145, that might act as a gatekeeper restricting access to the binding site. Site-directed mutagenesis of Ile-145 leads to significantly reduced hydrolase activity. Bacterial MGLs in complex with 1-lauroylglycerol, myristoyl, palmitoyl, and stearoyl substrate analogs enable identification of the binding sites for the alkyl chain and the glycerol moiety of the natural ligand. They also provide snapshots of the hydrolytic reaction of a bacterial MGL at different stages. The alkyl chains are buried in a hydrophobic tunnel in an extended conformation. Binding of the glycerol moiety is mediated via Glu-156 and water molecules. Analysis of the structural features responsible for cap plasticity and the binding modes of the ligands suggests conservation of these features also in human MGL. PMID:24014019

  9. Ribosyl and Deoxyribosyl Transfer by Bacterial Enzyme Systems

    PubMed Central

    Imada, Akira; Igarasi, Seizi

    1967-01-01

    The enzymatic transfer of ribose and deoxyribose residues in pyrimidine nucleosides to purines was catalyzed by cell-free extracts of various bacteria. Almost all the strains belonging to Enterobacteriaceae were capable of catalyzing the transfer reactions. The transfer activities were also detected among some bacterial strains of other families: Pseudomonadaceae, Corynebacteriaceae, Micrococcaceae, Bacteriaceae, and Bacillaceae. The rates of the transfer reactions were greatly enhanced in the presence of phosphate ion, and the participation of nucleoside phosphorylases in the reactions was suggested. Uridine phosphorylase, thymidine phosphorylase, and purine nucleoside phosphorylase were purified from cell-free extract of Aerobacter aerogenes IFO 3321. The ribosyl transfer from uridine to hypoxanthine was found to be catalyzed by the coupled reactions of uridine and purine nucleoside phosphorylases and the deoxyribosyl transfer from thymidine to hypoxanthine by the coupled reactions of thymidine and purine nucleoside phosphorylases. PMID:4863982

  10. Selective detection of bacterial layers with terahertz plasmonic antennas

    PubMed Central

    Berrier, Audrey; Schaafsma, Martijn C.; Nonglaton, Guillaume; Bergquist, Jonas; Rivas, Jaime Gómez

    2012-01-01

    Current detection and identification of micro-organisms is based on either rather unspecific rapid microscopy or on more accurate but complex and time-consuming procedures. In a medical context, the determination of the bacteria Gram type is of significant interest. The diagnostic of microbial infection often requires the identification of the microbiological agent responsible for the infection, or at least the identification of its family (Gram type), in a matter of minutes. In this work, we propose to use terahertz frequency range antennas for the enhanced selective detection of bacteria types. Several microorganisms are investigated by terahertz time-domain spectroscopy: a fast, contactless and damage-free investigation method to gain information on the presence and the nature of the microorganisms. We demonstrate that plasmonic antennas enhance the detection sensitivity for bacterial layers and allow the selective recognition of the Gram type of the bacteria. PMID:23162730

  11. Bacterial ecology of abattoir wastewater treated by an anaerobic digestor.

    PubMed

    Jabari, Linda; Gannoun, Hana; Khelifi, Eltaief; Cayol, Jean-Luc; Godon, Jean-Jacques; Hamdi, Moktar; Fardeau, Marie-Laure

    2016-01-01

    Wastewater from an anaerobic treatment plant at a slaughterhouse was analysed to determine the bacterial biodiversity present. Molecular analysis of the anaerobic sludge obtained from the treatment plant showed significant diversity, as 27 different phyla were identified. Firmicutes, Proteobacteria, Bacteroidetes, Thermotogae, Euryarchaeota (methanogens), and msbl6 (candidate division) were the dominant phyla of the anaerobic treatment plant and represented 21.7%, 18.5%, 11.5%, 9.4%, 8.9%, and 8.8% of the total bacteria identified, respectively. The dominant bacteria isolated were Clostridium, Bacteroides, Desulfobulbus, Desulfomicrobium, Desulfovibrio and Desulfotomaculum. Our results revealed the presence of new species, genera and families of microorganisms. The most interesting strains were characterised. Three new bacteria involved in anaerobic digestion of abattoir wastewater were published. PMID:26887229

  12. Bacterial ecology of abattoir wastewater treated by an anaerobic digestor

    PubMed Central

    Jabari, Linda; Gannoun, Hana; Khelifi, Eltaief; Cayol, Jean-Luc; Godon, Jean-Jacques; Hamdi, Moktar; Fardeau, Marie-Laure

    2016-01-01

    Wastewater from an anaerobic treatment plant at a slaughterhouse was analysed to determine the bacterial biodiversity present. Molecular analysis of the anaerobic sludge obtained from the treatment plant showed significant diversity, as 27 different phyla were identified. Firmicutes, Proteobacteria, Bacteroidetes, Thermotogae, Euryarchaeota (methanogens), and msbl6 (candidate division) were the dominant phyla of the anaerobic treatment plant and represented 21.7%, 18.5%, 11.5%, 9.4%, 8.9%, and 8.8% of the total bacteria identified, respectively. The dominant bacteria isolated were Clostridium, Bacteroides, Desulfobulbus, Desulfomicrobium, Desulfovibrio and Desulfotomaculum. Our results revealed the presence of new species, genera and families of microorganisms. The most interesting strains were characterised. Three new bacteria involved in anaerobic digestion of abattoir wastewater were published. PMID:26887229

  13. The AbgT family: A novel class of antimetabolite transporters.

    PubMed

    Delmar, Jared A; Yu, Edward W

    2016-02-01

    The AbgT family of transporters was thought to contribute to bacterial folate biosynthesis by importing the catabolite p-aminobenzoyl-glutamate for producing this essential vitamin. Approximately 13,000 putative transporters of the family have been identified. However, before our work, no structural information was available and even functional data were minimal for this family of membrane proteins. To elucidate the structure and function of the AbgT family of transporters, we recently determined the X-ray structures of the full-length Alcanivorax borkumensis YdaH and Neisseria gonorrhoeae MtrF membrane proteins. The structures reveal that these two transporters assemble as dimers with architectures distinct from all other families of transporters. Both YdaH and MtrF are bowl-shaped dimers with a solvent-filled basin extending from the cytoplasm halfway across the membrane bilayer. The protomers of YdaH and MtrF contain nine transmembrane helices and two hairpins. These structures directly suggest a plausible pathway for substrate transport. A combination of the crystal structure, genetic analysis and substrate accumulation assay indicates that both YdaH and MtrF behave as exporters, capable of removing the folate metabolite p-aminobenzoic acid from bacterial cells. Further experimental data based on drug susceptibility and radioactive transport assay suggest that both YdaH and MtrF participate as antibiotic efflux pumps, importantly mediating bacterial resistance to sulfonamide antimetabolite drugs. It is possible that many of these AbgT-family transporters act as exporters, thereby conferring bacterial resistance to sulfonamides. The AbgT-family transporters may be important targets for the rational design of novel antibiotics to combat bacterial infections. PMID:26443496

  14. Marine mesocosm bacterial colonisation of volcanic ash

    NASA Astrophysics Data System (ADS)

    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 physico-chemical composition of the substrate. Knowledge on pioneer bacterial colonisation may increase our understanding on the resilience of coral reefs to natural "catastrophes", such as volcanic ash fallout.

  15. Human mesenchymal stem cells: New sojourn of bacterial pathogens.

    PubMed

    Kohli, Sakshi; Singh, Yadvir; Sowpati, Divya Tej; Ehtesham, Nasreen Z; Dobrindt, Ulrich; Hacker, Jörg; Hasnain, Seyed E

    2015-05-01

    Tuberculosis (TB), caused by Mycobacterium tuberculosis (M. tuberculosis), is the leading infectious disease which claims one human life every 15-20s globally. The persistence of this deadly disease in human population can be attributed to the ability of the bacterium to stay in latent form. M. tuberculosis possesses a plethora of mechanisms not only to survive latently under harsh conditions inside the host but also modulate the host immune cells in its favour. Various M. tuberculosis gene families have also been described to play a role in this process. Recently, human bone marrow derived mesenchymal stem cells (MSCs) have been reported as a niche for dormant M. tuberculosis. MSCs possess abilities to alter the host immune response. The bacterium finds this self-renewal and immune privileged nature of MSCs very favourable not only to modulate the host immune system, with some help from its own genes, but also to avoid the external drug pressure. We suggest that the MSCs not only provide a resting place for M. tuberculosis but could also, by virtue of their intrinsic ability to disseminate in the body, explain the genesis of extra-pulmonary TB. A similar exploitation of stem cells by other bacterial pathogens is a distinct possibility. It may be likely that other intracellular bacterial pathogens adopt this strategy to 'piggy-back' on to ovarian stem cells to ensure vertical transmission and successful propagation to the next generation. PMID:25648374

  16. Bacterial Carbonic Anhydrases as Drug Targets: Toward Novel Antibiotics?

    PubMed Central

    Supuran, Claudiu T.

    2011-01-01

    Carbonic anhydrases (CAs, EC 4.2.1.1) are metalloenzymes which catalyze the hydration of carbon dioxide to bicarbonate and protons. Many pathogenic bacteria encode such enzymes belonging to the ?-, ?-, and/or ?-CA families. In the last decade, the ?-CAs from Neisseria spp. and Helicobacter pylori as well as the ?-class enzymes from Escherichia coli, H. pylori, Mycobacterium tuberculosis, Brucella spp., Streptococcus pneumoniae, Salmonella enterica, and Haemophilus influenzae have been cloned and characterized in detail. For some of these enzymes the X-ray crystal structures were determined, and in vitro and in vivo inhibition studies with various classes of inhibitors, such as anions, sulfonamides and sulfamates reported. Although efficient inhibitors have been reported for many such enzymes, only for Neisseria spp., H. pylori, B. suis, and S. pneumoniae enzymes it has been possible to evidence inhibition of bacterial growth in vivo. Thus, bacterial CAs represent promising targets for obtaining antibacterials devoid of the resistance problems of the clinically used such agents but further studies are needed to validate these and other less investigated enzymes as novel drug targets. PMID:21779249

  17. Sulfur minimization in bacterial leaching

    SciTech Connect

    Seth, R.; Prasad, D.; Henry, J.G.

    1996-11-01

    The production of sewage biosolids in Ontario in 1989 was estimated to be 7 million m{sup 3} of wet sludge per year. Of this amount, land application accounts for between 20 and 30% of the total. Unfortunately, the use of sewage biosolids on agricultural land is often prohibited because of heavy metal contamination of the biosolids. High cost and operational problems have made chemical methods of metal extraction unattractive. Consequently, microbiological methods of leaching of heavy metals have been studied for over a decade. A relatively simple microbiological process has been investigated in recent years in flask level experiments and recently in a semicontinuous system. The process exploits nonacidophilic and acidophilic indigenous thiobacilli to extract heavy metals from sewage biosolids. These thiobacilli use elemental sulfur as the energy source, producing sulfuric acid. However, the resulting decontaminated biosolids can cause environmental problems like acidification of the soil, when acid is generated from the residual sulfur in the biosolids. The present study examines the possibility of reducing the amount of sulfur added in batch and semicontinuous bacterial leaching systems, and maximizing sulfur oxidation efficiency, thereby reducing the residual sulfur in leached biosolids.

  18. Asymptomatic Bacteriuria and Bacterial Interference.

    PubMed

    Nicolle, Lindsay E

    2015-10-01

    Asymptomatic bacteriuria is very common. In healthy women, asymptomatic bacteriuria increases with age, from <1% in newborns to 10% to 20% of women age 80 years, but is uncommon in men until after age 50 years. Individuals with underlying genitourinary abnormalities, including indwelling devices, may also have a high frequency of asymptomatic bacteriuria, irrespective of age or gender. The prevalence is very high in residents of long-term-care facilities, from 25% to 50% of women and 15% to 40% of men. Escherichia coli is the most frequent organism isolated, but a wide variety of other organisms may occur. Bacteriuria may be transient or persist for a prolonged period. Pregnant women with asymptomatic bacteriuria identified in early pregnancy and who are untreated have a risk of pyelonephritis later in pregnancy of 20% to 30%. Bacteremia is frequent in bacteriuric subjects following mucosal trauma with bleeding, with 5% to 10% of patients developing severe sepsis or septic shock. These two groups with clear evidence of negative outcomes should be screened for bacteriuria and appropriately treated. Asymptomatic bacteriuria in other populations is benign and screening and treatment are not indicated. Antimicrobial treatment has no benefits but is associated with negative outcomes including reinfection with antimicrobial resistant organisms and a short-term increased frequency of symptomatic infection post-treatment. The observation of increased symptomatic infection post-treatment, however, has led to active investigation of bacterial interference as a strategy to prevent symptomatic episodes in selected high risk patients. PMID:26542046

  19. [Laboratory diagnosis of bacterial vaginosis].

    PubMed

    Pliutto, A M

    1997-03-01

    Microbiological analysis of discharge from the genitals in passenger car conductors (5787 women and 1496 men aged 20 to 40) showed Gardnerella vaginalis to be the most frequent agent of urogenital infection. It was isolated in 26% cases, whereas Trichomonas were isolated in 2.5%, fungi in 1.5%, and gonococci in 0.27% cases. The diagnosis of gardnerellosis is reliable if the key cells are found. Monoinfection with G. vaginalis was diagnosed in 80% patients, the overwhelming majority (74%) of carriers of this bacterium had no inflammatory symptoms, and in only 26% the carrier state was associated with the presence of leukocytes and histiocytes, more often in the cervix. In men the carrier state was detected in 0.4% cases. The clinical picture of Gardnerella infection is similar to that of infection with Mobiluncus, which is little known. This infection occurred 10 times less frequently (2.5%) than gardnerellosis, but in 92% cases it was a component of mixed infection, most frequently in association with G. vaginalis. A little known fungus Leptothrix was found in the genital discharge of 4% examinees, mostly women, but sometimes in men as well; it is represented by 3 types of ramifying threads. The practitioners are to know these infections causing specific diseases, such as bacterial vaginosis, which are often responsible for serious complications in gynecology and obstetrics. PMID:9410459

  20. Antibacterial Diamines Targeting Bacterial Membranes.

    PubMed

    Wang, Bo; Pachaiyappan, Boobalan; Gruber, Jordon D; Schmidt, Michael G; Zhang, Yong-Mei; Woster, Patrick M

    2016-04-14

    Antibiotic resistance is a growing threat to human health exacerbated by a lack of new antibiotics. We now describe a series of substituted diamines that produce rapid bactericidal activity against both Gram-positive and Gram-negative bacteria, including methicillin-resistant Staphylococcus aureus and stationary-phase bacteria. These compounds reduce biofilm formation and promote biofilm dispersal in Pseudomonas aeruginosa. The most potent analogue, 3 (1,13-bis{[(2,2-diphenyl)-1-ethyl]thioureido}-4,10-diazatridecane), primarily acts by depolarization of the cytoplasmic membrane and permeabilization of the bacterial outer membrane. Transmission electron microscopy confirmed that 3 disrupts membrane integrity rapidly. Compound 3 is also synergistic with kanamycin, demonstrated by the checkerboard method and by time-kill kinetic experiments. In human cell toxicity assays, 3 showed limited adverse effects against the HEK293T human kidney embryonic cells and A549 human adenocarcinoma cells. In addition, 3 produced no adverse effects on Caenorhabditis elegans development, survival, and reproduction. Collectively, diamines related to 3 represent a new class of broad-spectrum antibacterials against drug-resistant pathogens. PMID:26964758