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. 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 × 10(7) CFU/mL and ?3.57 × 10(6) CFU/mL, respectively. The greatest L. anguillarum concentration examined (8.7 × 10(6) 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. Received December 9, 2014; accepted February 7, 2015. PMID:25970236

  3. Habitat Segregation and Biochemical Activities of Marine Members of the Family Vibrionaceae

    PubMed Central

    Simidu, Usio; Tsukamoto, Kumiko

    1985-01-01

    A comparative study of marine members of the family Vibrionaceae with the technique of numerical taxonomy revealed habitat segregation as well as a cosmopolitan nature of species distribution among the vibrios in different marine environments. The bacterial strains analyzed were isolated from seawater, sediments, phyto- and zooplankton, and fish in the Indian Ocean, the South and East China Sea, and West Pacific Ocean, and coastal areas of Japan. A total of 155 morphological, physiological, and biochemical tests were carried out for each of 405 strains examined. The results showed that most of the large taxonomical clusters which emerged from the computation corresponded to ecological groups which have particular niches. For instance, each group of seawater vibrios inhabited a particular water layer of limited depth range, in spite of the fact that strains of the group were isolated from sampling locations spread over a wide area from the Indian Ocean to Japanese coast. Various vibrio groups showed remarkable differences in their physiological and biochemical activities, and the activities of each group seemed to correspond with its ecological niche. The strains which inhabited surface-water layers grew fast and actively utilized many high-molecular-weight organic compounds and carbohydrates that are derived from fresh, easily degradable organic matter present in the surface waters, whereas the middle- and deep-water vibrios did not decompose most of the high-molecular-weight organic compounds except chitin but, rather, utilized some carbohydrates and organic acids which seemed to be derived from refractory particulate organic matter present in the deeper waters. PMID:16346911

  4. Comparative genomics of the family Vibrionaceae reveals the wide distribution of genes encoding virulence-associated proteins

    Microsoft Academic Search

    Timothy G Lilburn; Jianying Gu; Hong Cai; Yufeng Wang

    2010-01-01

    BACKGROUND: Species of the family Vibrionaceae are ubiquitous in marine environments. Several of these species are important pathogens of humans and marine species. Evidence indicates that genetic exchange plays an important role in the emergence of new pathogenic strains within this family. Data from the sequenced genomes of strains in this family could show how the genes encoded by all

  5. Comparative genomics of the family Vibrionaceae reveals the wide distribution of genes encoding virulence-associated proteins

    PubMed Central

    2010-01-01

    Background Species of the family Vibrionaceae are ubiquitous in marine environments. Several of these species are important pathogens of humans and marine species. Evidence indicates that genetic exchange plays an important role in the emergence of new pathogenic strains within this family. Data from the sequenced genomes of strains in this family could show how the genes encoded by all these strains, known as the pangenome, are distributed. Information about the core, accessory and panproteome of this family can show how, for example, genes encoding virulence-associated proteins are distributed and help us understand how virulence emerges. Results We deduced the complete set of orthologs for eleven strains from this family. The core proteome consists of 1,882 orthologous groups, which is 28% of the 6,629 orthologous groups in this family. There were 4,411 accessory orthologous groups (i.e., proteins that occurred in from 2 to 10 proteomes) and 5,584 unique proteins (encoded once on only one of the eleven genomes). Proteins that have been associated with virulence in V. cholerae were widely distributed across the eleven genomes, but the majority was found only on the genomes of the two V. cholerae strains examined. Conclusions The proteomes are reflective of the differing evolutionary trajectories followed by different strains to similar phenotypes. The composition of the proteomes supports the notion that genetic exchange among species of the Vibrionaceae is widespread and that this exchange aids these species in adapting to their environments. PMID:20537180

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

    E-print Network

    Chien, Diana M.

    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 ...

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

    E-print Network

    Dikow, R. B.; Smith, William Leo

    2013-04-11

    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...

  8. Molecular characterization of cold adaptation based on ortholog protein sequences from Vibrionaceae species

    Microsoft Academic Search

    Steinar Thorvaldsen; Erik Hjerde; Chris Fenton; Nils P. Willassen

    2007-01-01

    A set of 298 protein families from psychrophilic Vibrio salmonicida was compiled to identify genotypic characteristics that discern it from orthologous sequences from the mesophilic Vibrio\\/Photobacterium\\u000a branch of the gamma-Proteobacteria (Vibrionaceae family). In our comparative exploration we employed alignment based bioinformatical and statistical methods. Interesting\\u000a information was found in the substitution matrices, and the pattern of asymmetries in the amino

  9. 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

  10. Topological and Phylogenetic Analyses of Bacterial Holin Families and Superfamilies

    PubMed Central

    Reddy, Bhaskara L.; Saier, Milton H.

    2013-01-01

    Holins are small “hole-forming” transmembrane proteins that mediate bacterial cell lysis during programmed cell death or following phage infection. We have identified fifty two families of established or putative holins and have included representative members of these proteins in the Transporter Classification Database (TCDB; www.tcdb.org). We have identified the organismal sources of members of these families, calculated their average protein sizes, estimated their topologies and determined their relative family sizes. Topological analyses suggest that these proteins can have 1, 2, 3 or 4 transmembrane ?-helical segments (TMSs), and members of a single family are frequently, but not always, of a single topology. In one case, proteins of a family proved to have either 2 or 4 TMSs, and the latter arose by intragenic duplication of a primordial 2 TMS protein-encoding gene resembling the former. Using established statistical approaches, some of these families have been shown to be related by common descent. Seven superfamilies, including 21 of the 52 recognized families were identified. Conserved motif and Pfam analyses confirmed most superfamily assignments. These results serve to expand upon the scope of channel-forming bacterial holins. PMID:23856191

  11. 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

  12. Histone modifications induced by a family of bacterial toxins

    PubMed Central

    Hamon, Mélanie Anne; Batsché, Eric; Régnault, Béatrice; Tham, To Nam; Seveau, Stéphanie; Muchardt, Christian; Cossart, Pascale

    2007-01-01

    Upon infection, pathogens reprogram host gene expression. In eukaryotic cells, genetic reprogramming is induced by the concerted activation/repression of transcription factors and various histone modifications that control DNA accessibility in chromatin. We report here that the bacterial pathogen Listeria monocytogenes induces a dramatic dephosphorylation of histone H3 as well as a deacetylation of histone H4 during early phases of infection. This effect is mediated by the major listerial toxin listeriolysin O in a pore-forming-independent manner. Strikingly, a similar effect also is observed with other toxins of the same family, such as Clostridium perfringens perfringolysin and Streptococcus pneumoniae pneumolysin. The decreased levels of histone modifications correlate with a reduced transcriptional activity of a subset of host genes, including key immunity genes. Thus, control of epigenetic regulation emerges here as an unsuspected function shared by several bacterial toxins, highlighting a common strategy used by intracellular and extracellular pathogens to modulate the host response early during infection. PMID:17675409

  13. Systematic identification of stem-loop containing sequence families in bacterial genomes

    Microsoft Academic Search

    Luca Cozzuto; Mauro Petrillo; Giustina Silvestro; Pier Paolo Di Nocera; Giovanni Paolella

    2008-01-01

    BACKGROUND: Analysis of non-coding sequences in several bacterial genomes brought to the identification of families of repeated sequences, able to fold as secondary structures. These sequences have often been claimed to be transcribed and fulfill a functional role. A previous systematic analysis of a representative set of 40 bacterial genomes produced a large collection of sequences, potentially able to fold

  14. 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

  15. 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

  16. 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

  17. 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

  18. Application of sliding-window discretization and minimization of stochastic complexity for the analysis of fAFLP genotyping fingerprint patterns of Vibrionaceae.

    PubMed

    Dawyndt, Peter; Thompson, Fabiano L; Austin, Brian; Swings, Jean; Koski, Timo; Gyllenberg, Mats

    2005-01-01

    Minimization of stochastic complexity (SC) was used as a method for classification of genotypic fingerprints. The method was applied to fluorescent amplified fragment length polymorphism (fAFLP) fingerprint patterns of 507 Vibrionaceae representatives. As the current BinClass implementation of the optimization algorithm for classification only works on binary vectors, the original fingerprints were discretized in a preliminary step using the sliding-window band-matching method, in order to maximally preserve the information content of the original band patterns. The novel classification generated using the BinClass software package was subjected to an in-depth comparison with a hierarchical classification of the same dataset, in order to acknowledge the applicability of the new classification method as a more objective algorithm for the classification of genotyping fingerprint patterns. Recent DNA-DNA hybridization and 16S rRNA gene sequence experiments proved that the classification based on SC-minimization forms separate clusters that contain the fAFLP patterns for all representatives of the species Enterovibrio norvegicus, Vibrio fortis, Vibrio diazotrophicus or Vibrio campbellii, while previous hierarchical cluster analysis had suggested more heterogeneity within the fAFLP patterns by splitting the representatives of the above-mentioned species into multiple distant clusters. As a result, the new classification methodology has highlighted some previously unseen relationships within the biodiversity of the family Vibrionaceae. PMID:15653853

  19. 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

  20. 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

  1. 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

  2. Defense Against Cannibalism: The SdpI Family of Bacterial Immunity/Signal Transduction Proteins

    PubMed Central

    Povolotsky, Tatyana Leonidovna; Orlova, Ekaterina; Tamang, Dorjee G.

    2010-01-01

    The SdpI family consists of putative bacterial toxin immunity and signal transduction proteins. One member of the family in Bacillus subtilis, SdpI, provides immunity to cells from cannibalism in times of nutrient limitation. SdpI family members are transmembrane proteins with 3, 4, 5, 6, 7, 8, or 12 putative transmembrane ?-helical segments (TMSs). These varied topologies appear to be genuine rather than artifacts due to sequencing or annotation errors. The basic and most frequently occurring element of the SdpI family has 6 TMSs. Homologues of all topological types were aligned to determine the homologous TMSs and loop regions, and the positive-inside rule was used to determine sidedness. The two most conserved motifs were identified between TMSs 1 and 2 and TMSs 4 and 5 of the 6 TMS proteins. These showed significant sequence similarity, leading us to suggest that the primordial precursor of these proteins was a 3 TMS–encoding genetic element that underwent intragenic duplication. Various deletional and fusional events, as well as intragenic duplications and inversions, may have yielded SdpI homologues with topologies of varying numbers and positions of TMSs. We propose a specific evolutionary pathway that could have given rise to these distantly related bacterial immunity proteins. We further show that genes encoding SdpI homologues often appear in operons with genes for homologues of SdpR, SdpI’s autorepressor. Our analyses allow us to propose structure–function relationships that may be applicable to most family members. Electronic supplementary material The online version of this article (doi:10.1007/s00232-010-9260-7) contains supplementary material, which is available to authorized users. PMID:20563570

  3. Stealth Proteins: In Silico Identification of a Novel Protein Family Rendering Bacterial Pathogens Invisible to Host Immune Defense

    Microsoft Academic Search

    Peter Sperisen; Christoph D. Schmid; Philipp Bucher; Olav Zilian

    2005-01-01

    There are a variety of bacterial defense strategies to survive in a hostile environment. Generation of extracellular polysaccharides has proved to be a simple but effective strategy against the host's innate immune system. A comparative genomics approach led us to identify a new protein family termed Stealth, most likely involved in the synthesis of extracellular polysaccharides. This protein family is

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

    PubMed

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

    2014-10-01

    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 (K(d)?2 µM). Mutation of XC_3703 led to reduced virulence of Xcc to plants and alteration in biofilm formation. Yeast two-hybrid and far-western analyses showed that XC_3703 was able to interact with XC_2801, a transcription factor of the LysR family. Mutation of XC_2801 and XC_3703 had partially overlapping effects on the transcriptome of Xcc, and both affected virulence. Electromobility shift assays showed that XC_3703 positively affected the binding of XC_2801 to the promoters of target virulence genes, an effect that was reversed by cyclic di-GMP. Genetic and functional analysis of YajQ family members from the human pathogens Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed that they also specifically bound cyclic di-GMP and contributed to virulence in model systems. The findings thus identify a new class of cyclic di-GMP effector that regulates bacterial virulence. PMID:25329577

  5. Sliding window discretization: a new method for multiple band matching of bacterial genotyping fingerprints.

    PubMed

    Austin, Brian; Dawyndt, Peter; Gyllenberg, Mats; Koski, Timo; Lund, Tatu; Swings, Jean; Thompson, Fabiano L

    2004-11-01

    Microbiologists have traditionally applied hierarchical clustering algorithms as their mathematical tool of choice to unravel the taxonomic relationships between micro-organisms. However, the interpretation of such hierarchical classifications suffers from being subjective, in that a variety of ad hoc choices must be made during their construction. On the other hand, the application of more profound and objective mathematical methods--such as the minimization of stochastic complexity--for the classification of bacterial genotyping fingerprints data is hampered by the prerequisite that such methods only act upon vectorized data. In this paper we introduce a new method, coined sliding window discretization, for the transformation of genotypic fingerprint patterns into binary vector format. In the context of an extensive amplified fragment length polymorphism (AFLP) data set of 507 strains from the Vibrionaceae family that has previously been analysed, we demonstrate by comparison with a number of other discretization methods that this new discretization method results in minimal loss of the original information content captured in the banding patterns. Finally, we investigate the implications of the different discretization methods on the classification of bacterial genotyping fingerprints by minimization of stochastic complexity, as it is implemented in the BinClass software package for probabilistic clustering of binary vectors. The new taxonomic insights learned from the resulting classification of the AFLP patterns will prove the value of combining sliding window discretization with minimization of stochastic complexity, as an alternative classification algorithm for bacterial genotyping fingerprints. PMID:15522346

  6. A Novel Alkaliphilic Bacillus Esterase Belongs to the 13th Bacterial Lipolytic Enzyme Family

    PubMed Central

    Rao, Lang; Xue, Yanfen; Zheng, Yingying; Lu, Jian R.; Ma, Yanhe

    2013-01-01

    Background Microbial derived lipolytic hydrolysts are an important class of biocatalysts because of their huge abundance and ability to display bioactivities under extreme conditions. In spite of recent advances, our understanding of these enzymes remains rudimentary. The aim of our research is to advance our understanding by seeking for more unusual lipid hydrolysts and revealing their molecular structure and bioactivities. Methodology/Principal Findings Bacillus. pseudofirmus OF4 is an extreme alkaliphile with tolerance of pH up to 11. In this work we successfully undertook a heterologous expression of a gene estof4 from the alkaliphilic B. pseudofirmus sp OF4. The recombinant protein called EstOF4 was purified into a homologous product by Ni-NTA affinity and gel filtration. The purified EstOF4 was active as dimer with the molecular weight of 64 KDa. It hydrolyzed a wide range of substrates including p-nitrophenyl esters (C2–C12) and triglycerides (C2–C6). Its optimal performance occurred at pH 8.5 and 50°C towards p-nitrophenyl caproate and triacetin. Sequence alignment revealed that EstOF4 shared 71% identity to esterase Est30 from Geobacillus stearothermophilus with a typical lipase pentapeptide motif G91LS93LG95. A structural model developed from homology modeling revealed that EstOF4 possessed a typical esterase 6?/7? hydrolase fold and a cap domain. Site-directed mutagenesis and inhibition studies confirmed the putative catalytic triad Ser93, Asp190 and His220. Conclusion EstOF4 is a new bacterial esterase with a preference to short chain ester substrates. With a high sequence identity towards esterase Est30 and several others, EstOF4 was classified into the same bacterial lipolytic family, Family XIII. All the members in this family originate from the same bacterial genus, bacillus and display optimal activities from neutral pH to alkaline conditions with short and middle chain length substrates. However, with roughly 70% sequence identity, these enzymes showed hugely different thermal stabilities, indicating their diverse thermal adaptations via just changing a few amino acid residues. PMID:23577139

  7. 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

  8. Isolation and Characterization of a Novel Lipase from a Metagenomic Library of Tidal Flat Sediments: Evidence for a New Family of Bacterial Lipases?

    PubMed Central

    Lee, Mi-Hwa; Lee, Choong-Hwan; Oh, Tae-Kwang; Song, Jae Kwang; Yoon, Jung-Hoon

    2006-01-01

    We cloned lipG, which encoded a lipolytic enzyme, from a Korean tidal flat metagenomic library. LipG was related to six putative lipases previously identified only in bacterial genome sequences. These enzymes comprise a new family. We partially characterized LipG, providing the first experimental data for a member of this family. PMID:16950897

  9. Molecular Mechanisms and Inhibition of Transcription Activation by Bacterial AraC Family Activator Proteins

    E-print Network

    Koppolu, Veerendra

    2013-12-31

    C family proteins, I tested the small molecule SE-1, which our lab identified as an effective inhibitor of the AraC family proteins RhaS and RhaR. Despite limited sequence identity, SE-1 was also shown to inhibit VirF and Rns activity in cell-based assays...

  10. 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. [Univ. Hospital, Hamburg (Germany)] [and others] [Univ. Hospital, Hamburg (Germany); and others

    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.

  11. Draft Genome Sequences of Two Vibrionaceae Species, Vibrio ponticus C121 and Photobacterium aphoticum C119, Isolated as Coral Reef Microbiota

    PubMed Central

    Al-saari, Nurhidayu; Meirelles, Pedro Milet; Mino, Sayaka; Suda, Wataru; Oshima, Kenshiro; Hattori, Masahira; Ohkuma, Moriya; Thompson, Fabiano L.; Gomez-Gil, Bruno; Sawabe, Toko

    2014-01-01

    Here, the draft genome sequences of two Vibrionaceae, Vibrio ponticus C121 and Photobacterium aphoticum C119, which were isolated from the coral reef vicinity in Okinawa, Japan, are reported. The genome provides further insight into the genomic plasticity, biocomplexity, and ecophysiology, including pathogenicity and evolution, of these genera. PMID:25359913

  12. 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.

  13. Exploring the chemistry of uncultivated bacterial symbionts: antitumor polyketides of the pederin family.

    PubMed

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

    2005-03-01

    Symbiotic bacteria have long been proposed as being responsible for the production of numerous natural products isolated from invertebrate animals. However, systematic studies of invertebrate-symbiont associations are usually associated with serious technical challenges, such as the general resistance of symbionts to culturing attempts and the complexity of many microbial consortia. Herein an overview is provided on the culture-independent, metagenomic strategies recently employed by our group to contribute to a better understanding of natural product symbiosis. Using terrestrial Paederus spp. beetles and the marine sponge Theonella swinhoei as model animals, the putative genes responsible for the production of pederin-type antitumor polyketides have been isolated. In Paederus fuscipes, which uses pederin for chemical defense, these genes belong to an as-yet unculturable symbiont closely related to Pseudomonas aeruginosa. To study the extremely complex association of T. swinhoei and its multispecies bacterial consortium, we used a phylogenetic approach that allowed the isolation of onnamide/theopederin polyketide synthase genes from an uncultured sponge symbiont. Analysis of the biosynthesis genes provided unexpected insights into a possible evolution of pederin-type pathways. Besides revealing new facets of invertebrate chemical ecology, these first gene clusters from uncultivated symbiotic producers suggest possible biotechnological strategies to solve the supply problem associated with the development of most marine drug candidates. PMID:15787465

  14. Identification of two partners from the bacterial Kef exchanger family for the apical plasma membrane V-ATPase of Metazoa.

    PubMed

    Day, Jonathan P; Wan, Susan; Allan, Adrian K; Kean, Laura; Davies, Shireen A; Gray, Joe V; Dow, Julian A T

    2008-08-01

    The vital task of vectorial solute transport is often energised by a plasma membrane, proton-motive V-ATPase. However, its proposed partner, an apical alkali-metal/proton exchanger, has remained elusive. Here, both FlyAtlas microarray data and in situ analyses demonstrate that the bacterial kefB and kefC (members of the CPA2 family) homologues in Drosophila, CG10806 and CG31052, respectively, are both co-expressed with V-ATPase genes in transporting epithelia. Immunocytochemistry localises endogenous CG10806 and CG31052 to the apical plasma membrane of the Malpighian (renal) tubule. YFP-tagged CG10806 and CG31052 both localise to the plasma membrane of Drosophila S2 cells, and when driven in principal cells of the Malpighian tubule, they localise specifically to the apical plasma membrane. V-ATPase-energised fluid secretion is affected by overexpression of CG10806, but not CG31052; in the former case, overexpression causes higher basal rates, but lower stimulated rates, of fluid secretion compared with parental controls. Overexpression also impacts levels of secreted Na+ and K+. Both genes rescue exchanger-deficient (nha1 nhx1) yeast, but act differently; CG10806 is driven predominantly to the plasma membrane and confers protection against excess K+, whereas CG31052 is expressed predominantly on the vacuolar membrane and protects against excess Na+. Thus, both CG10806 and CG31052 are functionally members of the CPA2 gene family, colocalise to the same apical membrane as the plasma membrane V-ATPase and show distinct ion specificities, as expected for the Wieczorek exchanger. PMID:18628302

  15. The Legionella effector SidC defines a unique family of ubiquitin ligases important for bacterial phagosomal remodeling

    PubMed Central

    Hsu, FoSheng; Luo, Xi; Qiu, Jiazhang; Teng, Yan-Bin; Jin, Jianping; Smolka, Marcus B.; Luo, Zhao-Qing; Mao, Yuxin

    2014-01-01

    The activity of proteins delivered into host cells by the Dot/Icm injection apparatus allows Legionella pneumophila to establish a niche called the Legionella-containing vacuole (LCV), which is permissive for intracellular bacterial propagation. Among these proteins, substrate of Icm/Dot transporter (SidC) anchors to the cytoplasmic surface of the LCV and is important for the recruitment of host endoplasmic reticulum (ER) proteins to this organelle. However, the biochemical function underlying this activity is unknown. Here, we determined the structure of the N-terminal domain of SidC, which has no structural homology to any protein. Sequence homology analysis revealed a potential canonical catalytic triad formed by Cys46, His444, and Asp446 on the surface of SidC. Unexpectedly, we found that SidC is an E3 ubiquitin ligase that uses the C–H–D triad to catalyze the formation of high–molecular-weight polyubiquitin chains through multiple ubiquitin lysine residues. A C46A mutation completely abolished the E3 ligase activity and the ability of the protein to recruit host ER proteins as well as polyubiquitin conjugates to the LCV. Thus, SidC represents a unique E3 ubiquitin ligase family important for phagosomal membrane remodeling by L. pneumophila. PMID:25006264

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

    Microsoft Academic Search

    Nina Peitsaro; Zydrune Polianskyte; Jarno Tuimala; Isabella Pörn-Ares; Julius Liobikas; Oliver Speer; Dan Lindholm; James Thompson; Ove Eriksson

    2008-01-01

    BACKGROUND: Bacterial penicillin-binding proteins and ?-lactamases (PBP-?Ls) constitute a large family of serine proteases that perform essential functions in the synthesis and maintenance of peptidoglycan. Intriguingly, genes encoding PBP-?L homologs occur in many metazoan genomes including humans. The emerging role of LACTB, a mammalian mitochondrial PBP-?L homolog, in metabolic signaling prompted us to investigate the evolutionary history of metazoan PBP-?L

  17. Long-term evolutionary stability of bacterial endosymbiosis in curculionoidea: additional evidence of symbiont replacement in the dryophthoridae family.

    PubMed

    Conord, Cyrille; Despres, Laurence; Vallier, Agnčs; Balmand, Séverine; Miquel, Christian; Zundel, Stéphanie; Lemperiere, Guy; Heddi, Abdelaziz

    2008-05-01

    Bacterial intracellular symbiosis (endosymbiosis) is well documented in the insect world where it is believed to play a crucial role in adaptation and evolution. However, although Coleopteran insects are of huge ecological and economical interest, endosymbiont molecular analysis is limited to the Dryophthoridae family. Here, we have analyzed the intracellular symbiotic bacteria in 2 Hylobius species belonging to the Molytinae subfamily (Curculionoidea superfamily) that exhibit different features from the Dryophthoridae insects in terms of their ecology and geographical spanning. Fluorescence in situ hybridization has shown that both Hylobius species harbor rod-shaped pleiomorphic symbiotic bacteria in the oocyte and in the bacteria-bearing organ (the bacteriome), with a shape and location similar to those of the Dryophthoridae bacteriome. Phylogenetic analysis of the 16S ribosomal DNA gene sequences, using the heterogeneous model of DNA evolution, has placed the Hylobius spp. endosymbionts (H-group) at the basal position of the ancestral R-clade of Dryophthoridae endosymbionts named Candidatus Nardonella but relatively distant from the S-clade of Sitophilus spp. endosymbionts. Endosymbionts from the H-group and the R-clade evolved more quickly compared with free-living enteric bacteria and endosymbionts from the S- and D-clades of Dryophthoridae. They are AT biased (58.3% A + T), and they exhibit AT-rich insertions at the same position as previously described in the Candidatus Nardonella 16S rDNA sequence. Moreover, the host phylogenetic tree based on the mitochondrial COI gene was shown to be highly congruent with the H-group and the R-clade, the divergence of which was estimated to be around 125 MYA. These new molecular data show that endosymbiosis is old in Curculionids, going back at least to the common ancestor of Molytinae and Dryophthoridae, and is evolutionary stable, except in 2 Dryophthoridae clades, providing additional and independent supplementary evidence for endosymbiont replacement in these taxa. PMID:18310662

  18. Exploring the reactivity of bacterial multicomponent monooxygenases

    E-print Network

    Tinberg, Christine Elaine

    2010-01-01

    Chapter 1. Introduction: The Reactivity of Bacterial Multicomponent Monooxygenases Bacterial multicomponent monooxygenases constitute a remarkable family of enzymes that oxidize small, inert hydrocarbon substrates using ...

  19. [Allomonas--a new group of microorganisms of the Vibrionaceae family. Allomonas enterica in seawater and various hydrobiotas].

    PubMed

    Davyborshch, S G; Kalina, G P

    1985-09-01

    Bacteriological investigations made in the Black Sea, the Sea of Azov and the Sea of Japan have revealed that Allomonas enterica are widely spread in sea water and hydrobionts. The prevalence of these microorganisms in biotopes with unfavorable sanitary characteristics and their high correlation with the main indicator microorganisms suggest their importance as indicators, and a high percentage of seafood contaminated with Allomonas necessitates their study as possible causative agents of toxinfections. PMID:2933905

  20. 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

  1. The unusual transmembrane electron transporter DsbD and its homologues: a bacterial family of disulfide reductases

    Microsoft Academic Search

    Amir Porat; Seung-Hyun Cho; Jon Beckwith

    2004-01-01

    The bacterial membrane protein DsbD transfers electrons across the cytoplasmic membrane to reduce protein disulfide bonds in extracytoplasmic proteins. Its substrates include protein disulfide isomerases and a protein involved in cytochrome c assembly. Two membrane-embedded cysteines in DsbD alternate between the disulfide-bonded (oxidized) and reduced states in this process.

  2. 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

  3. Genes Similar to the Vibrio parahaemolyticus Virulence-Related Genes tdh, tlh, and vscC2 Occur in Other Vibrionaceae Species Isolated from a Pristine Estuary

    PubMed Central

    Klein, Savannah L.; Gutierrez West, Casandra K.; Mejia, Diana M.

    2014-01-01

    Detection of the human pathogen Vibrio parahaemolyticus often relies on molecular biological analysis of species-specific virulence factor genes. These genes have been employed in determinations of V. parahaemolyticus population numbers and the prevalence of pathogenic V. parahaemolyticus strains. Strains of the Vibrionaceae species Photobacterium damselae, Vibrio diabolicus, Vibrio harveyi, and Vibrio natriegens, as well as strains similar to Vibrio tubiashii, were isolated from a pristine salt marsh estuary. These strains were examined for the V. parahaemolyticus hemolysin genes tdh, trh, and tlh and for the V. parahaemolyticus type III secretion system 2? gene vscC2 using established PCR primers and protocols. Virulence-related genes occurred at high frequencies in non-V. parahaemolyticus Vibrionaceae species. V. diabolicus was of particular interest, as several strains were recovered, and the large majority (>83%) contained virulence-related genes. It is clear that detection of these genes does not ensure correct identification of virulent V. parahaemolyticus. Further, the occurrence of V. parahaemolyticus-like virulence factors in other vibrios potentially complicates tracking of outbreaks of V. parahaemolyticus infections. PMID:24212573

  4. Architecture and assembly of a divergent member of the ParM family of bacterial actin like proteins

    E-print Network

    Mullins, Dyche

    proteins Christopher R. Rivera, 1 Justin M. Kollman, 2,3 Jessica K. Polka, 1 David A. Agard, 2,3 and R in a divergent member of the ParM family from plasmid pB171. Previous work demonstrated that R1 ParM assembles only 41% identical, R1 and pB171 ParMs polymerize into nearly identical filaments with similar assembly

  5. Crystal structure of a bacterial family-III cellulose-binding domain: a general mechanism for attachment to cellulose.

    PubMed Central

    Tormo, J; Lamed, R; Chirino, A J; Morag, E; Bayer, E A; Shoham, Y; Steitz, T A

    1996-01-01

    The crystal structure of a family-III cellulose-binding domain (CBD) from the cellulosomal scaffoldin subunit of Clostridium thermocellum has been determined at 1.75 A resolution. The protein forms a nine-stranded beta sandwich with a jelly roll topology and binds a calcium ion. conserved, surface-exposed residues map into two defined surfaces located on opposite sides of the molecule. One of these faces is dominated by a planar linear strip of aromatic and polar residues which are proposed to interact with crystalline cellulose. The other conserved residues are contained in a shallow groove, the function of which is currently unknown, and which has not been observed previously in other families of CBDs. On the basis of modeling studies combined with comparisons of recently determined NMR structures for other CBDs, a general model for the binding of CBDs to cellulose is presented. Although the proposed binding of the CBD to cellulose is essentially a surface interaction, specific types and combinations of amino acids appear to interact selectively with glucose moieties positioned on three adjacent chains of the cellulose surface. The major interaction is characterized by the planar strip of aromatic residues, which align along one of the chains. In addition, polar amino acid residues are proposed to anchor the CBD molecule to two other adjacent chains of crystalline cellulose. Images PMID:8918451

  6. In vitro transposition of ISY100, a bacterial insertion sequence belonging to the Tc1/mariner family.

    PubMed

    Feng, Xiaofeng; Colloms, Sean D

    2007-09-01

    The Synechocystis sp. PCC6803 insertion sequence ISY100 (ISTcSa) belongs to the Tc1/mariner/IS630 family of transposable elements. ISY100 transposase was purified and shown to promote transposition in vitro. Transposase binds specifically to ISY100 terminal inverted repeat sequences via an N-terminal DNA-binding domain containing two helix-turn-helix motifs. Transposase is the only protein required for excision and integration of ISY100. Transposase made double-strand breaks on a supercoiled DNA molecule containing a mini-ISY100 transposon, cleaving exactly at the transposon 3' ends and two nucleotides inside the 5' ends. Cleavage of short linear substrates containing a single transposon end was less precise. Transposase also catalysed strand transfer, covalently joining the transposon 3' end to the target DNA. When a donor plasmid carrying a mini-ISY100 was incubated with a target plasmid and transposase, the most common products were insertions of one transposon end into the target DNA, but insertions of both ends at a single target site could be recovered after transformation into Escherichia coli. Insertions were almost exclusively into TA dinucleotides, and the target TA was duplicated on insertion. Our results demonstrate that there are no fundamental differences between the transposition mechanisms of IS630 family elements in bacteria and Tc1/mariner elements in higher eukaryotes. PMID:17680987

  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. GntR Family of Bacterial Transcription Factors and Their DNA Binding Motifs: Structure, Positioning and Co-Evolution

    PubMed Central

    Suvorova, Inna A.; Korostelev, Yuri D.; Gelfand, Mikhail S.

    2015-01-01

    The GntR family of transcription factors (TFs) is a large group of proteins present in diverse bacteria and regulating various biological processes. Here we use the comparative genomics approach to reconstruct regulons and identify binding motifs of regulators from three subfamilies of the GntR family, FadR, HutC, and YtrA. Using these data, we attempt to predict DNA-protein contacts by analyzing correlations between binding motifs in DNA and amino acid sequences of TFs. We identify pairs of positions with high correlation between amino acids and nucleotides for FadR, HutC, and YtrA subfamilies and show that the most predicted DNA-protein interactions are quite similar in all subfamilies and conform well to the experimentally identified contacts formed by FadR from E. coli and AraR from B. subtilis. The most frequent predicted contacts in the analyzed subfamilies are Arg-G, Asn-A, Asp-C. We also analyze the divergon structure and preferred site positions relative to regulated genes in the FadR and HutC subfamilies. A single site in a divergon usually regulates both operons and is approximately in the middle of the intergenic area. Double sites are either involved in the co-operative regulation of both operons and then are in the center of the intergenic area, or each site in the pair independently regulates its own operon and tends to be near it. We also identify additional candidate TF-binding boxes near palindromic binding sites of TFs from the FadR, HutC, and YtrA subfamilies, which may play role in the binding of additional TF-subunits. PMID:26151451

  9. Mosquitocidal properties of Calotropis gigantea (Family: Asclepiadaceae) leaf extract and bacterial insecticide, Bacillus thuringiensis, against the mosquito vectors.

    PubMed

    Kovendan, Kalimuthu; Murugan, Kadarkarai; Prasanna Kumar, Kanagarajan; Panneerselvam, Chellasamy; Mahesh Kumar, Palanisamy; Amerasan, Duraisamy; Subramaniam, Jayapal; Vincent, Savariar

    2012-08-01

    Calotropis gigantea leaf extract and Bacillus thuringiensis were tested first to fourth-instar larvae and pupae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The medicinal plants were collected from the area around Bharathiar University, Coimbatore, India. Calotropis gigantea leaf was washed with tap water and shade-dried at room temperature. An electrical blender powdered the dried plant materials (leaves). The powder 500 g of the leaf was extracted with 1.5 L of organic solvents of methanol for 8 h using a Soxhlet apparatus and filtered. The crude leaf extracts were evaporated to dryness in a rotary vacuum evaporator. The plant extract showed larvicidal and pupicidal effects after 24 h of exposure; no mortality was observed in the control group. For Calotropis gigantea, the median lethal concentration values (LC(50)) observed for the larvicidal and pupicidal activities against mosquito vector species Anopheles stephensi I to IV larval instars and pupae were 73.77, 89.64, 121.69, 155.49, and 213.79 ppm; Aedes aegypti values were 92.27, 106.60, 136.48, 164.01, and 202.56 ppm; and Culex quinquefasciatus values were 104.66, 127.71, 173.75, 251.65, and 314.70 ppm, respectively. For B. thuringiensis, the LC(50) values of I to IV larval instars and pupae of Anopheles stephensi were 37.24, 45.41, 57.82, 80.09, and 98.34 ppm; Aedes aegypti values were 42.38, 51.90, 71.02, 96.17, and 121.59 ppm; and Culex quinquefasciatus values were 55.85, 68.07, 94.11, 113.35, and 133.87 ppm, respectively. The study proved that the methanol leaf extract of Calotropis gigantea and bacterial insecticide B. thuringiensis has mosquitocidal property and was evaluated as target species of mosquito vectors. This is an ideal ecofriendly approach for the control of vector control programs. PMID:22382205

  10. Structural and mechanistic insights into collagen degradation by a bacterial collagenolytic serine protease in the subtilisin family.

    PubMed

    Ran, Li-Yuan; Su, Hai-Nan; Zhao, Guo-Yan; Gao, Xiang; Zhou, Ming-Yang; Wang, Peng; Zhao, Hui-Lin; Xie, Bin-Bin; Zhang, Xi-Ying; Chen, Xiu-Lan; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2013-12-01

    A number of proteases in the subtilisin family derived from environmental or pathogenic microorganisms have been reported to be collagenolytic serine proteases. However, their collagen degradation mechanisms remain unclear. Here, the degradation mechanism of type I collagen fibres by the S8 collagenolytic protease MCP-01, from Pseudoalteromonas sp. SM9913, was studied. Atomic force microscopy observation and biochemical analysis confirmed that MCP-01 progressively released single fibrils from collagen fibres and released collagen monomers from fibrils mainly by hydrolysing proteoglycans and telopeptides in the collagen fibres. Structural and mutational analyses indicated that an enlarged substrate-binding pocket, mainly composed of loops 7, 9 and 11, is necessary for collagen recognition and that the acidic and aromatic residues on these loops form a negatively charged, hydrophobic environment for collagen binding. MCP-01 displayed a non-strict preference for peptide bonds with Pro or basic residues at the P1 site and/or Gly at the P1' site in collagen. His211 is a key residue for the P1-basic-residue preference of MCP-01. Our study gives structural and mechanistic insights into collagen degradation of the S8 collagenolytic protease, which is helpful in developing therapeutics for diseases with S8 collagenolytic proteases as pathogenic factors and in studying environmental organic nitrogen degradation mechanisms. PMID:24112706

  11. A Family of Bacterial Cysteine Protease Type III Effectors Utilizes Acylation-dependent and -independent Strategies to Localize to Plasma Membranes*

    PubMed Central

    Dowen, Robert H.; Engel, James L.; Shao, Feng; Ecker, Joseph R.; Dixon, Jack E.

    2009-01-01

    Bacterial phytopathogens employ a type III secretion system to deliver effector proteins into the plant cell to suppress defense pathways; however, the molecular mechanisms and subcellular localization strategies that drive effector function largely remain a mystery. Here, we demonstrate that the plant plasma membrane is the primary site for subcellular localization of the Pseudomonas syringae effector AvrPphB and five additional cysteine protease family members. AvrPphB and two AvrPphB-like effectors, ORF4 and NopT, autoproteolytically process following delivery into the plant cell to expose embedded sites for fatty acylation. Host-dependent lipidation of these three effectors directs plasma membrane localization and is required for the avirulence activity of AvrPphB. Surprisingly, the AvrPphB-like effectors RipT, HopC1, and HopN1 utilize an acylation-independent mechanism to localize to the cellular plasma membrane. Although some AvrPphB-like effectors employ acylation-independent localization strategies, others hijack the eukaryotic lipidation machinery to ensure plasma membrane localization, illustrating the diverse tactics employed by type III effectors to target specific subcellular compartments. PMID:19346252

  12. Characterization and three-dimensional structures of two distinct bacterial xyloglucanases from families GH5 and GH12.

    PubMed

    Gloster, Tracey M; Ibatullin, Farid M; Macauley, Katherine; Eklöf, Jens M; Roberts, Shirley; Turkenburg, Johan P; Bjřrnvad, Mads E; Jřrgensen, Per Linĺ; Danielsen, Steffen; Johansen, Katja S; Borchert, Torben V; Wilson, Keith S; Brumer, Harry; Davies, Gideon J

    2007-06-29

    The plant cell wall is a complex material in which the cellulose microfibrils are embedded within a mesh of other polysaccharides, some of which are loosely termed "hemicellulose." One such hemicellulose is xyloglucan, which displays a beta-1,4-linked d-glucose backbone substituted with xylose, galactose, and occasionally fucose moieties. Both xyloglucan and the enzymes responsible for its modification and degradation are finding increasing prominence, reflecting both the drive for enzymatic biomass conversion, their role in detergent applications, and the utility of modified xyloglucans for cellulose fiber modification. Here we present the enzymatic characterization and three-dimensional structures in ligand-free and xyloglucan-oligosaccharide complexed forms of two distinct xyloglucanases from glycoside hydrolase families GH5 and GH12. The enzymes, Paenibacillus pabuli XG5 and Bacillus licheniformis XG12, both display open active center grooves grafted upon their respective (beta/alpha)(8) and beta-jelly roll folds, in which the side chain decorations of xyloglucan may be accommodated. For the beta-jelly roll enzyme topology of GH12, binding of xylosyl and pendant galactosyl moieties is tolerated, but the enzyme is similarly competent in the degradation of unbranched glucans. In the case of the (beta/alpha)(8) GH5 enzyme, kinetically productive interactions are made with both xylose and galactose substituents, as reflected in both a high specific activity on xyloglucan and the kinetics of a series of aryl glycosides. The differential strategies for the accommodation of the side chains of xyloglucan presumably facilitate the action of these microbial hydrolases in milieus where diverse and differently substituted substrates may be encountered. PMID:17376777

  13. Identification and Characterization of a Novel Bacterial Virulence Factor That Shares Homology with Mammalian Toll\\/Interleukin1 Receptor Family Proteins

    Microsoft Academic Search

    Ruchi M. Newman; Prabhakar Salunkhe; Adam Godzik; John C. Reed

    2006-01-01

    Many important bacterial virulence factors act as mimics of mammalian proteins to subvert normal host cell processes. To identify bacterial protein mimics of components of the innate immune signaling pathway, we searched the bacterial genome database for proteins with homology to the Toll\\/interleukin-1 receptor (TIR) domain of the mammalian Toll-like receptors (TLRs) and their adaptor proteins. A previously uncharacterized gene,

  14. 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.

  15. Isolation and characterization of a novel feather-degrading bacterial strain.

    PubMed

    Sangali, S; Brandelli, A

    2000-04-01

    Feather waste, generated in large quantities as a byproduct of commercial poultry processing, is almost pure keratin, which is not easily degradable by common proteolytic enzymes. Feather-degrading bacteria were isolated from a Brazilian poultry industrial waste. Among these isolates, a strain identified as kr2 was the best feather-degrading organism when grown on basal medium containing 10 g/L of native feather as a source of energy, carbon, and nitrogen. The isolate was characterized according to morphological characteristics and biochemical tests belonging to the Vibrionaceae family. Keratinolytic activity of this isolate was monitored throughout the cultivation of the bacterium on raw feather at different temperatures. The optimum temperature for growth was about 30 degrees C, at which maximum enzyme and soluble protein production were achieved. The enzyme had a pH and temperature optima of 8.0 and 55 degrees C, respectively. PMID:10850670

  16. Bacterial Vaginosis

    MedlinePLUS

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

  17. Expansion of the aminoglycoside-resistance 16S rRNA (m(1)A1408) methyltransferase family: expression and functional characterization of four hypothetical enzymes of diverse bacterial origin.

    PubMed

    Witek, Marta A; Conn, Graeme L

    2014-09-01

    The global dissemination, potential activity in diverse species and broad resistance spectrum conferred by the aminoglycoside-resistance ribosomal RNA methyltransferases make them a significant potential new threat to the efficacy of aminoglycoside antibiotics in the treatment of serious bacterial infections. The N1 methylation of adenosine 1408 (m(1)A1408) confers resistance to structurally diverse aminoglycosides, including kanamycin, neomycin and apramycin. The limited analyses to date of the enzymes responsible have identified common features but also potential differences in their molecular details of action. Therefore, with the goal of expanding the known 16S rRNA (m(1)A1408) methyltransferase family as a platform for developing a more complete mechanistic understanding, we report here the cloning, expression and functional analyses of four hypothetical aminoglycoside-resistance rRNA methyltransferases from recent genome sequences of diverse bacterial species. Each of the genes produced a soluble, folded protein with a secondary structure, as determined from circular dichroism (CD) spectra, consistent with enzymes for which high-resolution structures are available. For each enzyme, antibiotic minimum inhibitory concentration (MIC) assays revealed a resistance spectrum characteristic of the known 16S rRNA (m(1)A1408) methyltransferases and the modified nucleotide was confirmed by reverse transcription as A1408. In common with other family members, higher binding affinity for the methylation reaction by-product S-adenosylhomocysteine (SAH) than the cosubstrate S-adenosyl-L-methionine (SAM) was observed for three methyltransferases, while one unexpectedly showed no measurable affinity for SAH. Collectively, these results confirm that each hypothetical enzyme is a functional 16S rRNA (m(1)A1408) methyltransferase but also point to further potential mechanistic variation within this enzyme family. PMID:24963996

  18. Identification and Characterization of a Novel Bacterial Virulence Factor That Shares Homology with Mammalian Toll/Interleukin-1 Receptor Family Proteins

    PubMed Central

    Newman, Ruchi M.; Salunkhe, Prabhakar; Godzik, Adam; Reed, John C.

    2006-01-01

    Many important bacterial virulence factors act as mimics of mammalian proteins to subvert normal host cell processes. To identify bacterial protein mimics of components of the innate immune signaling pathway, we searched the bacterial genome database for proteins with homology to the Toll/interleukin-1 receptor (TIR) domain of the mammalian Toll-like receptors (TLRs) and their adaptor proteins. A previously uncharacterized gene, which we have named tlpA (for TIR-like protein A), was identified in the Salmonella enterica serovar Enteritidis genome that is predicted to encode a protein resembling mammalian TIR domains, We show that overexpression of TlpA in mammalian cells suppresses the ability of mammalian TIR-containing proteins TLR4, IL-1 receptor, and MyD88 to induce the transactivation and DNA-binding activities of NF-?B, a downstream target of the TIR signaling pathway. In addition, TlpA mimics the previously characterized Salmonella virulence factor SipB in its ability to induce activation of caspase-1 in a mammalian cell transfection model. Disruption of the chromosomal tlpA gene rendered a virulent serovar Enteritidis strain defective in intracellular survival and IL-1? secretion in a cell culture infection model using human THP1 macrophages. Bacteria with disrupted tlpA also displayed reduced lethality in mice, further confirming an important role for this factor in pathogenesis. Taken together, our findings demonstrate that the bacterial TIR-like protein TlpA is a novel prokaryotic modulator of NF-?B activity and IL-1? secretion that contributes to serovar Enteritidis virulence. PMID:16369016

  19. Identification and characterization of a novel bacterial virulence factor that shares homology with mammalian Toll/interleukin-1 receptor family proteins.

    PubMed

    Newman, Ruchi M; Salunkhe, Prabhakar; Godzik, Adam; Reed, John C

    2006-01-01

    Many important bacterial virulence factors act as mimics of mammalian proteins to subvert normal host cell processes. To identify bacterial protein mimics of components of the innate immune signaling pathway, we searched the bacterial genome database for proteins with homology to the Toll/interleukin-1 receptor (TIR) domain of the mammalian Toll-like receptors (TLRs) and their adaptor proteins. A previously uncharacterized gene, which we have named tlpA (for TIR-like protein A), was identified in the Salmonella enterica serovar Enteritidis genome that is predicted to encode a protein resembling mammalian TIR domains, We show that overexpression of TlpA in mammalian cells suppresses the ability of mammalian TIR-containing proteins TLR4, IL-1 receptor, and MyD88 to induce the transactivation and DNA-binding activities of NF-kappaB, a downstream target of the TIR signaling pathway. In addition, TlpA mimics the previously characterized Salmonella virulence factor SipB in its ability to induce activation of caspase-1 in a mammalian cell transfection model. Disruption of the chromosomal tlpA gene rendered a virulent serovar Enteritidis strain defective in intracellular survival and IL-1beta secretion in a cell culture infection model using human THP1 macrophages. Bacteria with disrupted tlpA also displayed reduced lethality in mice, further confirming an important role for this factor in pathogenesis. Taken together, our findings demonstrate that the bacterial TIR-like protein TlpA is a novel prokaryotic modulator of NF-kappaB activity and IL-1beta secretion that contributes to serovar Enteritidis virulence. PMID:16369016

  20. Bacterial Vaginosis

    MedlinePLUS

    ... 563-586. Related Content STDs & Pregnancy Fact Sheet Pregnancy and HIV, Viral Hepatitis, and STD Prevention Pelvic Inflammatory Disease ( ... Page Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes HIV/AIDS & STDs Human Papillomavirus ... STDs See Also Pregnancy Reproductive ...

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

    PubMed

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

    2012-05-01

    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. PMID:22283330

  2. 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.

  3. Protein engineering of bacterial ?-amylases

    Microsoft Academic Search

    Jens Erik Nielsen; Torben V. Borchert

    2000-01-01

    ?-Amylases constitute a very diverse family of glycosyl hydrolases that cleave ?1?4 linkages in amylose and related polymers. Recent structural and mutagenic studies of archeael, mammalian and bacterial ?-amylases have resulted in a wealth of information on the catalytic mechanism and on the structural features of this enzyme class. Because of their high thermo-stability, the Bacillus ?-amylases have found widespread

  4. Bacterial lipases

    Microsoft Academic Search

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

    1994-01-01

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, meaning a sharp increase in lipase activity observed when the substrate starts to form an emulsion, thereby presenting to

  5. [Bacterial Keratitis].

    PubMed

    Rachwalik, D; Pleyer, U

    2015-06-01

    Worldwide inflammatory corneal diseases are considered to be one of the leading causes of monocular blindness. Bacterial infectious are still predominant and are found in 80?% of patients with ulcerative keratitis. In recent years, both changes in risk conditions and changes in the bacterial spectrum can be observed. Contact lenses and refractive surgery are factors that have increased in importance according to some studies. Microorganisms especially Pseudomonas spp. and atypical mycobacteria are detectable in these patients. In contrast, the bacterial keratitis is observed less frequently after trauma. The broad, often unsighted use of highly effective antimicrobial agents, especially of fluoroquinolones is assumed to be a factor in the transformation of the microbial spectrum. Due to the frequent course of keratitis and a targeted, effective therapy to initiate a pathogen is desirable. The possibilities of diagnostics have been expanded in recent years by molecular biological techniques, but cannot replace established methods. The aim of this paper is to provide a positioning on current aspects of bacterial keratitis. PMID:26084962

  6. 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

  7. 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

  8. Structural Basis for Dimerization and Catalysis of a Novel Esterase from the GTSAG Motif Subfamily of the Bacterial Hormone-sensitive Lipase Family*

    PubMed Central

    Li, Ping-Yi; Ji, Peng; Li, Chun-Yang; Zhang, Yi; Wang, Guang-Long; Zhang, Xi-Ying; Xie, Bin-Bin; Qin, Qi-Long; Chen, Xiu-Lan; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2014-01-01

    Hormone-sensitive lipases (HSLs) are widely distributed in microorganisms, plants, and animals. Microbial HSLs are classified into two subfamilies, an unnamed new subfamily and the GDSAG motif subfamily. Due to the lack of structural information, the detailed catalytic mechanism of the new subfamily is not yet clarified. Based on sequence analysis, we propose to name the new subfamily as the GTSAG motif subfamily. We identified a novel HSL esterase E25, a member of the GTSAG motif subfamily, by functional metagenomic screening, and resolved its structure at 2.05 ?. E25 is mesophilic (optimum temperature at 50 °C), salt-tolerant, slightly alkaline (optimum pH at 8.5) for its activity, and capable of hydrolyzing short chain monoesters (C2–C10). E25 tends to form dimers both in the crystal and in solution. An E25 monomer contains an N-terminal CAP domain, and a classical ?/? hydrolase-fold domain. Residues Ser186, Asp282, and His312 comprise the catalytic triad. Structural and mutational analyses indicated that E25 adopts a dimerization pattern distinct from other HSLs. E25 dimer is mainly stabilized by an N-terminal loop intersection from the CAP domains and hydrogen bonds and salt bridges involving seven highly conserved hydrophilic residues from the catalytic domains. Further analysis indicated that E25 also has some catalytic profiles different from other HSLs. Dimerization is essential for E25 to exert its catalytic activity by keeping the accurate orientation of the catalytic Asp282 within the catalytic triad. Our results reveal the structural basis for dimerization and catalysis of an esterase from the GTSAG motif subfamily of the HSL family. PMID:24867954

  9. 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

  10. 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

  11. 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.

  12. 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

  13. A member of the cathelicidin family of antimicrobial peptides is produced in the upper airway of the chinchilla and its mRNA expression is altered by common viral and bacterial co-pathogens of otitis media

    Microsoft Academic Search

    Glen McGillivary; William C. Ray; Charles L. Bevins; Robert S. Munson Jr.; Lauren O. Bakaletz

    2007-01-01

    Cationic antimicrobial peptides (AMPs), a component of the innate immune system, play a major role in defense of mucosal surfaces against a wide spectrum of microorganisms such as viral and bacterial co-pathogens of the polymicrobial disease otitis media (OM). To further understand the role of AMPs in OM, we cloned a cDNA encoding a cathelicidin homolog (cCRAMP) from upper respiratory

  14. 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

  15. Mechanisms of bacterial pathogenicity

    PubMed Central

    Wilson, J; Schurr, M; LeBlanc, C; Ramamurthy, R; Buchanan, K; Nickerson, C

    2002-01-01

    Pathogenic bacteria utilise a number of mechanisms to cause disease in human hosts. Bacterial pathogens express a wide range of molecules that bind host cell targets to facilitate a variety of different host responses. The molecular strategies used by bacteria to interact with the host can be unique to specific pathogens or conserved across several different species. A key to fighting bacterial disease is the identification and characterisation of all these different strategies. The availability of complete genome sequences for several bacterial pathogens coupled with bioinformatics will lead to significant advances toward this goal. PMID:11930024

  16. 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

  17. Microfluidics for bacterial chemotaxis

    E-print Network

    Ahmed, Tanvir, Ph. D. Massachusetts Institute of Technology

    2011-01-01

    Bacterial chemotaxis, a remarkable behavioral trait which allows bacteria to sense and respond to chemical gradients in the environment, has implications in a broad range of fields including but not limited to disease ...

  18. Asphalt Showing Bacterial Degeneration 

    E-print Network

    Unknown

    2011-08-17

    Widely considered in the medical field as the last of the golden anti-microbial drugs, fluorinated quinolones provide a "last defense" for the attack on bacterial infections. The drugs are useful for treating gram negative and some gram positive...

  19. Bacterial Nasal Infections

    MedlinePLUS

    ... Version Ear, Nose, and Throat Disorders Nose and Sinus Disorders Bacterial Nasal Infections Nasal vestibulitis Nasal furuncles ... Version DOCTORS: Go to Professional Version Nose and Sinus Disorders Introduction to Nose and Sinus Disorders Deviated ...

  20. Growth of Bacterial Colonies

    NASA Astrophysics Data System (ADS)

    Warren, Mya; Hwa, Terence

    2013-03-01

    On hard agar gel, there is insufficient surface hydration for bacteria to swim or swarm. Instead, growth occurs in colonies of close-packed cells, which expand purely due to repulsive interactions: individual bacteria push each other out of the way through the force of their growth. In this way, bacterial colonies represent a new type of ``active'' granular matter. In this study, we investigate the physical, biochemical, and genetic elements that determine the static and dynamic aspects of this mode of bacterial growth for E. coli. We characterize the process of colony expansion empirically, and use discrete and continuum models to examine the extent to which our observations can be explained by the growth characteristics of non-communicating cells, coupled together by physical forces, nutrients, and waste products. Our results challenge the commonly accepted modes of bacterial colony growth and provide insight into sources of growth limitation in crowded bacterial communities.

  1. Family Folklore

    ERIC Educational Resources Information Center

    Kotkin, Amy J.; Baker, Holly C.

    1977-01-01

    Discusses the Family Folklore Program of the Smithsonian Institution's annual Festival of American Folklife, in which the whole family can be involved in tracing family history through story telling, photographs, etc. (MS)

  2. 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…

  3. CAMBer: An Approach to Support Comparative Analysis of Multiple Bacterial Strains

    E-print Network

    Wong, Limsoon

    sig- nificantly in some cases. As an extreme case of the problem, the strains of E. coli reportedly into correct gene families. For example, the extreme case of E. coli is probably due to the simple-minded BLAST genomic analysis of bacterial strains in promising applications such as gaining insights into bacterial

  4. Detection of type III secretion genes as a general indicator of bacterial virulence

    Microsoft Academic Search

    Katja Stuber; Joachim Frey; André P Burnens; Peter Kuhnert

    2003-01-01

    Type III secretion systems of Gram-negative bacteria are specific export machineries for virulence factors which allow their translocation to eukaryotic cells. Since they correlate with bacterial pathogenicity, their presence is used as a general indicator of bacterial virulence. By comparing the genetic relationship of the major type III secretion systems we found the family of genes encoding the inner-membrane channel

  5. Bacterial avirulence genes.

    PubMed

    Leach, J E; White, F F

    1996-01-01

    Although more than 30 bacterial avirulence genes have been cloned and characterized, the function of the gene products in the elictitation of resistance is unknown in all cases but one. The product of avrD from Pseudomonas syringae pv. glycinea likely functions indirectly to elicit resistance in soybean, that is, evidence suggests the gene product is an enzyme involved in elicitor production. In most if not all cases, bacterial avirulence gene function is dependent on interactions with the hypersensitive response and pathogenicity (hrp) genes. Many hrp genes are similar to genes involved in delivery of pathogenicity factors in mammalian bacterial pathogens. Thus, analogies between mammalian and plant pathogens may provide needed clues to elucidate how virulence gene products control induction of resistance. PMID:15012539

  6. An algebraic view of bacterial genome evolution.

    PubMed

    Francis, Andrew R

    2014-12-01

    Rearrangements of bacterial chromosomes can be studied mathematically at several levels, most prominently at a local, or sequence level, as well as at a topological level. The biological changes involved locally are inversions, deletions, and transpositions, while topologically they are knotting and catenation. These two modelling approaches share some surprising algebraic features related to braid groups and Coxeter groups. The structural approach that is at the core of algebra has long found applications in sciences such as physics and analytical chemistry, but only in a small number of ways so far in biology. And yet there are examples where an algebraic viewpoint may capture a deeper structure behind biological phenomena. This article discusses a family of biological problems in bacterial genome evolution for which this may be the case, and raises the prospect that the tools developed by algebraists over the last century might provide insight to this area of evolutionary biology. PMID:24375264

  7. [Bacterial overgrowth syndrome].

    PubMed

    Stein, J M; Schneider, A R

    2007-07-01

    Small bowel bacterial overgrowth is a syndrome caused by an abnormal number of bacteria in the upper part of the small bowel and associated with a complex array of clinical symptoms, i. e., chronic diarrhoea, steatorrhoea, macrocytic anaemia, weight loss, and less commonly, protein-losing enteropathy. The most common underlying factors are small intestinal stagnation or dysmotility, intestinal obstruction, blind or afferent loops, and decreased gastric secretion. The treatment usually consists in the eradication of bacterial overgrowth with repeated courses of antimicrobials, correction of associated nutritional deficiencies and, when possible, correction of the underlying predisposing conditions. PMID:17620228

  8. [Bacterial vaginosis and pregnancy].

    PubMed

    Canova, I; Caputo, S; Ciardo, A; Stragapede, B

    2002-01-01

    Premature rupture of membranes (PROM) occurs in approximately 5-10% of all pregnancies and is implicated in approximately one third of preterm births. PROM is associated with increased risks of perinatal as well as maternal morbidity and mortality at every gestational age. Much information suggest that the presence of bacterial vaginosis may be implicated in the occurrence of PROM and subsequent preterm delivery in significant numbers of pregnant women. We will briefly review clinical and pathophysiologic information linking bacterial vaginosis and PROM. PMID:12510420

  9. Urban aerosols harbor diverse and dynamic bacterial populations.

    PubMed

    Brodie, Eoin L; DeSantis, Todd Z; Parker, Jordan P Moberg; Zubietta, Ingrid X; Piceno, Yvette M; Andersen, Gary L

    2007-01-01

    Considering the importance of its potential implications for human health, agricultural productivity, and ecosystem stability, surprisingly little is known regarding the composition or dynamics of the atmosphere's microbial inhabitants. Using a custom high-density DNA microarray, we detected and monitored bacterial populations in two U.S. cities over 17 weeks. These urban aerosols contained at least 1,800 diverse bacterial types, a richness approaching that of some soil bacterial communities. We also reveal the consistent presence of bacterial families with pathogenic members including environmental relatives of select agents of bioterrorism significance. Finally, using multivariate regression techniques, we demonstrate that temporal and meteorological influences can be stronger factors than location in shaping the biological composition of the air we breathe. PMID:17182744

  10. Recent microbiological shifts in perianal bacterial dermatitis: Staphylococcus aureus predominance.

    PubMed

    Heath, Candrice; Desai, Nina; Silverberg, Nanette B

    2009-01-01

    Traditionally, bacterial infections of the anal skin have been found to be caused by Streptococcus. The aim of this study was to determine the breakdown of bacterial isolates and the current presentation of bacterial diseases involving the perineum. From the chart review of children who had bacterial cultures of the anus from 2005 to 2008 in a pediatric dermatology practice population in New York City, 26 pediatric patients (ages 5 months to 12 yrs) who had the indications of anal erythema or recurrent buttocks dermatitis were identified. Bacterial cultures of 17 patients grew pathogens, that of 14 (82% of identifiably infected patients) grew Staphylococcus aureus, in 11 as a solo pathogen (6 MSSA and 5 MRSA in 2 family clusters). Streptococcus was identified in three patients, two on culture and one on latex agglutination test; and two patients were identified as having both group A beta hemolytic Streptococcus and Staphylococcus aureus (2 MSSA and 1 MRSA). In patients with S. aureus perianally, concurrent small papules and pustules of the buttocks or extension of the erythema to adjacent buttock skin was the primary clinical feature distinguishing this condition from isolated streptococcal disease. Whereas Streptococcal infections of the anus and buttocks occur commonly, Staphylococcus aureus has become the leading cause of anal bacterial infection in the setting of skin involvement; therefore, antibacterial therapy for anal and buttock bacterial infections should be tailored accordingly. PMID:20199443

  11. 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

  12. 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...

  13. Bacterial social engagements

    Microsoft Academic Search

    Jennifer M. Henke; Bonnie L. Bassler

    2004-01-01

    Quorum sensing is a process that enables bacteria to communicate using secreted signaling molecules called autoinducers. This process enables a population of bac- teria to regulate gene expression collectively and, there- fore, control behavior on a community-wide scale. Quorum sensing is widespread in the bacterial world and, generally, processes controlled by quorum sensing are unproductive when undertaken by an individual

  14. 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...

  15. 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

  16. 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…

  17. 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);…

  18. 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

  19. 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

  20. Bacterial ratchet motors

    PubMed Central

    Di Leonardo, R.; Angelani, L.; Dell’Arciprete, D.; Ruocco, G.; Iebba, V.; Schippa, S.; Conte, M. P.; Mecarini, F.; De Angelis, F.; Di Fabrizio, E.

    2010-01-01

    Self-propelling bacteria are a nanotechnology dream. These unicellular organisms are not just capable of living and reproducing, but they can swim very efficiently, sense the environment, and look for food, all packaged in a body measuring a few microns. Before such perfect machines can be artificially assembled, researchers are beginning to explore new ways to harness bacteria as propelling units for microdevices. Proposed strategies require the careful task of aligning and binding bacterial cells on synthetic surfaces in order to have them work cooperatively. Here we show that asymmetric environments can produce a spontaneous and unidirectional rotation of nanofabricated objects immersed in an active bacterial bath. The propulsion mechanism is provided by the self-assembly of motile Escherichia coli cells along the rotor boundaries. Our results highlight the technological implications of active matter’s ability to overcome the restrictions imposed by the second law of thermodynamics on equilibrium passive fluids. PMID:20457936

  1. Bacterial-like PPP protein phosphatases

    PubMed Central

    Kerk, David; Uhrig, R Glen; Moorhead, Greg B

    2013-01-01

    Reversible phosphorylation is a widespread modification affecting the great majority of eukaryotic cellular proteins, and whose effects influence nearly every cellular function. Protein phosphatases are increasingly recognized as exquisitely regulated contributors to these changes. The PPP (phosphoprotein phosphatase) family comprises enzymes, which catalyze dephosphorylation at serine and threonine residues. Nearly a decade ago, “bacterial-like” enzymes were recognized with similarity to proteins from various bacterial sources: SLPs (Shewanella-like phosphatases), RLPHs (Rhizobiales-like phosphatases), and ALPHs (ApaH-like phosphatases). A recent article from our laboratory appearing in Plant Physiology characterizes their extensive organismal distribution, abundance in plant species, predicted subcellular localization, motif organization, and sequence evolution. One salient observation is the distinct evolutionary trajectory followed by SLP genes and proteins in photosynthetic eukaryotes vs. animal and plant pathogens derived from photosynthetic ancestors. We present here a closer look at sequence data that emphasizes the distinctiveness of pathogen SLP proteins and that suggests that they might represent novel drug targets. A second observation in our original report was the high degree of similarity between the bacterial-like PPPs of eukaryotes and closely related proteins of the “eukaryotic-like” phyla Myxococcales and Planctomycetes. We here reflect on the possible implications of these observations and their importance for future research. PMID:24675170

  2. Bacterial Resistance in Acne

    Microsoft Academic Search

    E. A. Eady

    1998-01-01

    Antibiotics play a major role in acne therapy. Physicians base treatment choices on personal perceptions of efficacy, cost-effectiveness or risk-benefit ratios and rarely take bacterial resistance into account. It is well documented that resistant strains of coagulase-negative staphylococci within the resident skin flora increase in both prevalence and population density as duration of therapy increases. Acne patients represent a considerable

  3. Human NLRP3 inflammasome senses multiple types of bacterial RNAs

    PubMed Central

    Sha, Wenwen; Mitoma, Hiroki; Hanabuchi, Shino; Bao, Musheng; Weng, Leiyun; Sugimoto, Naoshi; Liu, Ying; Zhang, Zhiqiang; Zhong, Jin; Sun, Bing; Liu, Yong-Jun

    2014-01-01

    Inflammasomes are multiprotein platforms that activate caspase-1, which leads to the processing and secretion of the proinflammatory cytokines IL-1? and IL-18. Previous studies demonstrated that bacterial RNAs activate the nucleotide-binding domain, leucine-rich-repeat-containing family, pyrin domain-containing 3 (NLRP3) inflammasome in both human and murine macrophages. Interestingly, only mRNA, but neither tRNA nor rRNAs, derived from bacteria could activate the murine Nlrp3 inflammasome. Here, we report that all three types of bacterially derived RNA (mRNA, tRNA, and rRNAs) were capable of activating the NLRP3 inflammasome in human macrophages. Bacterial RNA’s 5?-end triphosphate moieties, secondary structure, and double-stranded structure were dispensable; small fragments of bacterial RNA were sufficient to activate the inflammasome. In addition, we also found that 20-guanosine ssRNA can activate the NLRP3 inflammasome in human macrophages but not in murine macrophages. Therefore, human and murine macrophages may have evolved to recognize bacterial cytosolic RNA differently during bacterial infections. PMID:25355909

  4. Insights from twenty years of bacterial genome sequencing

    SciTech Connect

    Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Jun, Se Ran [ORNL; Nookaew, Intawat [ORNL; Leuze, Michael Rex [ORNL; Ahn, Tae-Hyuk [ORNL; Karpinets, Tatiana V [ORNL; Lund, Ole [Technical University of Denmark; Kora, Guruprasad H [ORNL; Wassenaar, Trudy [Molecular Microbiology & Genomics Consultants, Zotzenheim, Germany; Poudel, Suresh [ORNL; Ussery, David W [ORNL

    2015-01-01

    Since the first two complete bacterial genome sequences were published in 1995, the science of bacteria has dramatically changed. Using third-generation DNA sequencing, it is possible to completely sequence a bacterial genome in a few hours and identify some types of methylation sites along the genome as well. Sequencing of bacterial genome sequences is now a standard procedure, and the information from tens of thousands of bacterial genomes has had a major impact on our views of the bacterial world. In this review, we explore a series of questions to highlight some insights that comparative genomics has produced. To date, there are genome sequences available from 50 different bacterial phyla and 11 different archaeal phyla. However, the distribution is quite skewed towards a few phyla that contain model organisms. But the breadth is continuing to improve, with projects dedicated to filling in less characterized taxonomic groups. The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system provides bacteria with immunity against viruses, which outnumber bacteria by tenfold. How fast can we go? Second-generation sequencing has produced a large number of draft genomes (close to 90 % of bacterial genomes in GenBank are currently not complete); third-generation sequencing can potentially produce a finished genome in a few hours, and at the same time provide methlylation sites along the entire chromosome. The diversity of bacterial communities is extensive as is evident from the genome sequences available from 50 different bacterial phyla and 11 different archaeal phyla. Genome sequencing can help in classifying an organism, and in the case where multiple genomes of the same species are available, it is possible to calculate the pan- and core genomes; comparison of more than 2000 Escherichia coli genomes finds an E. coli core genome of about 3100 gene families and a total of about 89,000 different gene families. Why do we care about bacterial genome 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.

  5. Optimized Expression of IL-12 Cytokine Family

    Cancer.gov

    The IL-12 family of cytokines (IL-12, IL-23, and IL-27) plays a role in infection, inflammation and autoimmune diseases. IL-12 is produced by macrophages and dendritic cells in response to certain bacterial and parasitic infections and is a powerful inducer of IFN-gamma production.

  6. A family of halobacterial transducer proteins

    Microsoft Academic Search

    Johannes Rudolph; Barbara Nordmann; Kai-Florian Storch; Heidi Gruenberg; Karin Rodewald; Dieter Oesterhelt

    1996-01-01

    A DNA probe to the signaling domain of a halobacterial transducer for phototaxis (HtrI) was used to clone and sequence four members of a new family of transducer proteins (Htps) in Halobacterium salinarium potentially involved in chemo- or phototactic signal transduction. The signaling domains in these proteins have 31–43% identity when compared with each other or with their bacterial analogs,

  7. Identification of family specific fingerprints in ?-lactamase families.

    PubMed

    Srivastava, Abhishikha; Singhal, Neelja; Goel, Manisha; Virdi, Jugsharan Singh; Kumar, Manish

    2014-01-01

    Beta-lactamases are a superfamily of enzymes which degrade the ?-lactam class of antibiotics. They are produced endogenously by the bacterial cells, which when exposed to the ?-lactam class of antibiotics inactivate them by cleaving the ?-lactam ring. Based on the presence or absence of metallic ligand, ?-lactamases have been divided into two broad functional classes. ?-Lactamases are a constitutively evolving and expanding superfamily of enzymes, which could be further subdivided on the basis of presence/absence of conserved motifs. In the present study we have used the MEME/MAST suit to identify the patterns/motifs which are specific to a particular family or subfamily of ?-lactamases. The family specific patterns/motifs can be also useful in recognizing and assigning newly discovered ?-lactamases to one or the other family or subfamily. Cross-validation showed that the proposed method is highly sensitive and specific. We have also designed a webserver, LactFP, for this purpose. PMID:24678282

  8. Bacterial Fruit Blotch of Watermelon 

    E-print Network

    Isakeit, Thomas

    1999-06-28

    Bacterial fruit blotch is a disease occurring sporadically in almost all areas of Texas where watermelons are grown. This publication discusses symptoms, diagnosis and disease development and management....

  9. 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

  10. 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...

  11. 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...

  12. 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…

  13. 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...

  14. 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…

  15. 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. (PMCI-A); (Monash); (Nottingham)

    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.

  16. Composition of epiphytic bacterial communities differs on petals and leaves.

    PubMed

    Junker, R R; Loewel, C; Gross, R; Dötterl, S; Keller, A; Blüthgen, N

    2011-11-01

    The epiphytic bacterial communities colonising roots and leaves have been described for many plant species. In contrast, microbiologists have rarely considered flowers of naturally growing plants. We identified bacteria isolated from the surface of petals and leaves of two plant species, Saponaria officinalis (Caryophyllaceae) and Lotus corniculatus (Fabaceae). The bacterial diversity was much lower on petals than on leaves of the same plants. Moreover, the bacterial communities differed strongly in composition: while Pseudomonadaceae and Microbacteriaceae were the most abundant families on leaves, Enterobacteriaceae dominated the floral communities. We hypothesise that antibacterial floral volatiles trigger the low diversity on petals, which is supported by agar diffusion assays using substances emitted by flowers and leaves of S. officinalis. These results suggest that bacteria should be included in the interpretation of floral traits, and possible effects of bacteria on pollination are proposed and discussed. PMID:21972888

  17. 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

  18. Role of bacterial volatile compounds in bacterial biology.

    PubMed

    Audrain, Bianca; Farag, Mohamed A; Ryu, Choong-Min; Ghigo, Jean-Marc

    2015-03-01

    Bacterial interactions with neighboring microorganisms via production of small metabolites enable bacteria to respond and adapt to environmental changes. The study of intercellular interactions primarily focused on soluble metabolites, but bacteria also produce and release into their headspace a wide variety of volatile secondary metabolites, the ecological roles of which have generally been overlooked. However, bacterial volatile compounds are known to contribute to interkingdom interactions (plant, fungi and nematodes), and recent studies also identified their at-a-distance influence on bacterial behavior. The present review describes the biological roles of bacterial volatile compounds in inter- and intraspecies bacterial interactions, a new and yet unexplored research area, with potential clinical and industrial applications. PMID:25725014

  19. [Family ideology].

    PubMed

    Kornblit, A

    1982-06-01

    This paper treats the definition of the concept of family ideology linking it to that of social ideology. In both cases the ideology is seen as patterns of messages that obey certain semantic rules. Within the family context, it is considered that the conditions of production of the ideology are, concerning the profound structures, the unconscious oedipus conflict and kindred system that determines the family organization. Concerning the surface structures, the myths and beliefs that appear in each group as an answer to the need of accounting for the conflicts inherent to the family structure. The family ideology guides the subjects to places predetermined by the oedipus conflicts, "semanticizes" the conflicts and tends to dissimulate the conditions of production through the illusion that the subject is the producer. To analyze the family ideology, the following items must be taken into account: 1) Which are the semantic lines that are privileged in the couple and parent-children relationships. 2) The relations between the semantic lines established by the articulation rules prescribed by the cultural system. 3) The elementary forms of the ideological universe (the "actantial" model applied to family relationships). These three aspects articulate between themselves through transformation rules. PMID:7136827

  20. Bacterial lipopolysaccharides and innate immunity

    Microsoft Academic Search

    Christian Alexander; E. T. Rietschel

    2001-01-01

    Bacterial lipopolysaccharides (LPS) are the major outer surface membrane components present in almost all Gram-negative bacteria and act as extremely strong stimulators of innate or natural immunity in diverse eukaryotic species ranging from insects to humans. LPS consist of a poly- or oligosaccharide region that is anchored in the outer bacterial membrane by a specific carbohydrate lipid moiety termed lipid

  1. 7 CFR 58.135 - Bacterial estimate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...with respect to bacterial estimates: (1) Whenever the bacterial estimate indicates the presence of more than 500,000 bacteria per ml., the producer shall be notified with a warning of the excessive bacterial estimate. (2) Whenever two...

  2. Surface nanocrystallization for bacterial control.

    PubMed

    Yu, Bin; Lesiuk, Adam; Davis, Elisabeth; Irvin, Randall T; Li, D Y

    2010-07-01

    Stainless steel is commonly used in indwelling medical devices, food preparation, and heavy industry. Bacteria display reduced adherence to nanocrystallized stainless steel. In this article, we present quantitative information on the surface adhesive force, surface electron work function, and bacterial adherence to surfaces of nanocrystallized stainless steel with differing grain sizes. Surface nanocrystallization was achieved by sandblasting followed by recovery treatment. The adhesive force of bacterial binding to nanocrystallized surfaces was measured using an atomic force microscope with a synthetic-peptide-coated AFM tip designed to mimic the bacterial binding site of Pseudomonas aeruginosa, a common pathogen known to form biofilms. The electron work function of the steel surfaces was measured, and bacterial binding assays were performed using subinoculated P. aeruginosa cultures. It was demonstrated that for nanograined steel surfaces, the adhesive force, peptide adherence, surface electron activity, and bacterial binding all decreased with decreasing grain size. PMID:20433185

  3. The RND Permease Superfamily: An Ancient, Ubiquitous and Diverse Family that Includes Human Disease and Development Proteins

    Microsoft Academic Search

    Tsai-Tien Tseng; Kevin S. Gratwick; Justin Kollman; Daniel Park; Dietrich H. Nies; André Goffeau; Milton H. Saier

    A previous report identified and classified a small family of Gram-negative bacterial drug and heavy metal efflux permeases, now commonly referred to as the RND family (TC no. 2.6). We here show that this family is actually a ubiquitous superfamily with representation in all major kingdoms. We report phylogenetic analyses that define seven families within the RND superfamily as follows:

  4. Bacterial Identification Virtual Lab

    NSDL National Science Digital Library

    Created by the Howard Hughes Medical Institute (HHMI), the Virtual Bacterial Identification Lab provides interested parties with a great way to learn about the science and techniques used to identify different types of bacteria based on their DNA sequences. Visitors can enter the lab and get started by preparing samples from a patient, copying the desired pieces of the DNA, and then sequencing and analyzing the DNA. The entire experience is quite interactive: visitors can record their observations in the Notebook area and also learn about the various samples, which were obtained from stool, lymph nodes, urine, and blood. Finally, there's the Reference area, which contains a glossary of terms, a list of tools in the lab, and an encyclopedia of selected bacteria and other pathogens.

  5. Family History

    MedlinePLUS

    ... Brain Aneurysm Statistics and Facts Seeking Medical Attention Pediatric Aneurysms Brain Aneurysm Causes and Risk Factors Family History Early Detection and Screening Unruptured Brain Aneurysms Subarachnoid Hemorrhage Treatment Options Aneurysm Complications Post ...

  6. Families & Friendships

    MedlinePLUS

    ... Traumatic Brain Injury Life Stress Health & Wellness Anger Stigma Suicide Prevention Families with Kids Alcohol and Drugs ... Resilience Satisfaction with Life Sexual Truama Sleep Spirituality Stigma Stress Work Adjustment Worry Videos Post-Traumatic Stress ...

  7. Family Issues

    MedlinePLUS

    ... Relationships Self-Advocacy Navigating Services Autism Source Legal Resources Treatment Options Biomedical Treatments Nonmedical Interventions Related Approaches Evaluating Options Family Issues Stress Siblings Community Inclusion Autism and Faith Future Planning Government Benefits and ...

  8. IL-10 Function, Regulation, and in Bacterial Keratitis

    PubMed Central

    Jiang, Xiaoyu; McClellan, Sharon A.

    2014-01-01

    Abstract 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

    Humphries, Romney M; Linscott, Andrea J

    2015-01-01

    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 Central

    Asadi, Mohammad Reza; Torkaman, Giti

    2014-01-01

    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. 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

  12. 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.

  13. Antimicrobials for bacterial bioterrorism agents.

    PubMed

    Sarkar-Tyson, Mitali; Atkins, Helen S

    2011-06-01

    The limitations of current antimicrobials for highly virulent pathogens considered as potential bioterrorism agents drives the requirement for new antimicrobials that are suitable for use in populations in the event of a deliberate release. Strategies targeting bacterial virulence offer the potential for new countermeasures to combat bacterial bioterrorism agents, including those active against a broad spectrum of pathogens. Although early in the development of antivirulence approaches, inhibitors of bacterial type III secretion systems and cell division mechanisms show promise for the future. PMID:21707313

  14. 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

  15. 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

  16. 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

  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. 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.

  19. 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

  20. Bacterial associations of coniferous mycorrhizae

    Microsoft Academic Search

    E. T. Oswald; H. A. Ferchau

    1968-01-01

    Summary A study was made of the bacterial flora associated with mycorrhizae and non-mycorrhizal roots ofPicea engelmanni, P. pungens, Pinus aristata, P. flexilis, andPseudotsuga menziesii seedlings up to 3 dm in height.

  1. Doug Berndt Evaluated Bacterial Assay

    USGS Multimedia Gallery

    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....

  2. Prostatitis- bacterial - self-care

    MedlinePLUS

    You have been diagnosed with bacterial prostatitis . This is an infection of the prostate gland. ... Nonsteroidal anti-inflammatory medicines (NSAIDs), such as ibuprofen or naproxen, may help with pain or discomfort. Ask your doctor ...

  3. 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

  4. Identification and characterization of a bacterial glutamic peptidase

    PubMed Central

    2010-01-01

    Background Glutamic peptidases, from the MEROPS family G1, are a distinct group of peptidases characterized by a catalytic dyad consisting of a glutamate and a glutamine residue, optimal activity at acidic pH and insensitivity towards the microbial derived protease inhibitor, pepstatin. Previously, only glutamic peptidases derived from filamentous fungi have been characterized. Results We report the first characterization of a bacterial glutamic peptidase (pepG1), derived from the thermoacidophilic bacteria Alicyclobacillus sp. DSM 15716. The amino acid sequence identity between pepG1 and known fungal glutamic peptidases is only 24-30% but homology modeling, the presence of the glutamate/glutamine catalytic dyad and a number of highly conserved motifs strongly support the inclusion of pepG1 as a glutamic peptidase. Phylogenetic analysis places pepG1 and other putative bacterial and archaeal glutamic peptidases in a cluster separate from the fungal glutamic peptidases, indicating a divergent and independent evolution of bacterial and fungal glutamic peptidases. Purification of pepG1, heterologously expressed in Bacillus subtilis, was performed using hydrophobic interaction chromatography and ion exchange chromatography. The purified peptidase was characterized with respect to its physical properties. Temperature and pH optimums were found to be 60°C and pH 3-4, in agreement with the values observed for the fungal members of family G1. In addition, pepG1 was found to be pepstatin-insensitive, a characteristic signature of glutamic peptidases. Conclusions Based on the obtained results, we suggest that pepG1 can be added to the MEROPS family G1 as the first characterized bacterial member. PMID:21122090

  5. 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…

  6. 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)

  7. 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

  8. 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

  9. 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

  10. Gram-negative bacterial sensors for eukaryotic signal molecules.

    PubMed

    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-? 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

  11. Family Structure and Family Processes in Mexican American Families

    PubMed Central

    Zeiders, Katharine H.; Roosa, Mark W.; Tein, Jenn-Yun

    2010-01-01

    Despite increases in single-parent families among Mexican Americans (MA), few studies have examined the association of family structure and family adjustment. Utilizing a diverse sample of 738 Mexican American families (21.7% single parent), the current study examined differences across family structure on early adolescent outcomes, family functioning, and parent-child relationship variables. Results revealed that early adolescents in single parent families reported greater school misconduct, CD/ODD and MDD symptoms, and greater parent-child conflict than their counterparts in two parent families. Single parent mothers reported greater economic hardship, depression and family stress. Family stress and parent-child conflict emerged as significant mediators of the association between family structure and early adolescent outcomes, suggesting important processes linking MA single parent families and adolescent adjustment. PMID:21361925

  12. Roseobacticides: Small Molecule Modulators of an Algal-Bacterial Symbiosis

    PubMed Central

    2011-01-01

    Marine bacteria and microalgae engage in dynamic symbioses mediated by small molecules. A recent study of Phaeobacter gallaeciensis, a member of the large roseobacter clade of ?-proteobacteria, and Emiliania huxleyi, a prominent member of the microphytoplankton found in large algal blooms, revealed that an algal senescence signal produced by E. huxleyi elicits the production of novel algaecides, the roseobacticides, from the bacterial symbiont. In this report, the generality of these findings are examined by expanding the number of potential elicitors. This expansion led to the identification of nine new members of the roseobacticide family, rare bacterial troponoids, which provide insights into both their biological roles and their biosynthesis. The qualitative and quantitative changes in the levels of roseobacticides induced by the additional elicitors and the elicitors’ varied efficiencies support the concept of host-targeted roseobacticide production. Structures of the new family members arise from variable substituents at the C3 and C7 positions of the roseobacticide core as the diversifying elements and suggest that the roseobacticides result from modifications and combinations of aromatic amino acids. Together these studies support a model in which algal senescence converts a mutualistic bacterial symbiont into an opportunistic parasite of its hosts. PMID:21928816

  13. The Human Vaginal Bacterial Biota and Bacterial Vaginosis

    PubMed Central

    Srinivasan, Sujatha; Fredricks, David N.

    2008-01-01

    The bacterial biota of the human vagina can have a profound impact on the health of women and their neonates. Changes in the vaginal microbiota have been associated with several adverse health outcomes including premature birth, pelvic inflammatory disease, and acquisition of HIV infection. Cultivation-independent molecular methods have provided new insights regarding bacterial diversity in this important niche, particularly in women with the common condition bacterial vaginosis (BV). PCR methods have shown that women with BV have complex communities of vaginal bacteria that include many fastidious species, particularly from the phyla Bacteroidetes and Actinobacteria. Healthy women are mostly colonized with lactobacilli such as Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus iners, though a variety of other bacteria may be present. The microbiology of BV is heterogeneous. The presence of Gardnerella vaginalis and Atopobium vaginae coating the vaginal epithelium in some subjects with BV suggests that biofilms may contribute to this condition. PMID:19282975

  14. Bacterial penetration of restored cavities.

    PubMed

    Zivkovi?, S; Bojovi?, S; Pavlica, D

    2001-03-01

    The aim of this study was to assess the quality of the marginal seals of 7 restoratives by means of a bacterial penetration test in vitro. Sixty intact premolars and third molars that were scheduled for extraction were used in the test. There were 2 experimental groups of teeth, as follows: (1) A class V conventional cavity and a wedge erosion cavity were prepared on the buccal surface and the lingual surface, respectively, of each tooth. (2) A class V conventional cavity and a wedge erosion cavity were prepared on the buccal surface and the lingual surface, respectively, of each tooth with a completely removed enamel layer. The cavities were then reconstructed with different restorative materials. The quality of the marginal seals was evaluated by submerging the teeth in a bacterial suspension and incubating them in an anaerobic milieu at 37 degrees C for 20 hours. The teeth were subsequently processed for histologic data and bacterial staining. The best marginal sealing in both the wedge erosion and the class V cavities was provided by the Herculite/Optibond system and the Valux Plus/Scotchbond Multipurpose system. Bacterial penetration was slightly greater with the Luxat compomer and the Dyrect compomer, as well as with Vitremer glass ionomer cement and Fuji LC glass ionomer cement. The bacterial penetration test showed that the use of restorative material does not entirely eliminate microleakage. PMID:11250635

  15. 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

  16. Strategy for Identification of Novel Fungal and Bacterial Glycosyl Hydrolase Hybrid Mixtures that can Efficiently Saccharify Pretreated Lignocellulosic Biomass

    Microsoft Academic Search

    Dahai Gao; Shishir P. S. Chundawat; Tongjun Liu; Spencer Hermanson; Krishne Gowda; Phillip Brumm; Bruce E. Dale; Venkatesh Balan

    2010-01-01

    A rational four-step strategy to identify novel bacterial glycosyl hydrolases (GH), in combination with various fungal enzymes,\\u000a was applied in order to develop tailored enzyme cocktails to efficiently hydrolyze pretreated lignocellulosic biomass. The\\u000a fungal cellulases include cellobiohydrolase I (CBH I; GH family 7A), cellobiohydrolase II (CBH II; GH family 6A), endoglucanase\\u000a I (EG I; GH family 7B), and ?-glucosidase (?G;

  17. 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

  18. 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

  19. Bacterial tactic responses.

    PubMed

    Armitage, J P

    1999-01-01

    Many, if not most, bacterial species swim. The synthesis and operation of the flagellum, the most complex organelle of a bacterium, takes a significant percentage of cellular energy, particularly in the nutrient limited environments in which many motile species are found. It is obvious that motility accords cells a survival advantage over non-motile mutants under normal, poorly mixed conditions and is an important determinant in the development of many associations between bacteria and other organisms, whether as pathogens or symbionts and in colonization of niches and the development of biofilms. This survival advantage is the result of sensory control of swimming behaviour. Although too small to sense a gradient along the length of the cell, and unable to swim great distances because of buffetting by Brownian motion and the curvature resulting from a rotating flagellum, bacteria can bias their random swimming direction towards a more favourable environment. The favourable environment will vary from species to species and there is now evidence that in many species this can change depending on the current physiological growth state of the cell. In general, bacteria sense changes in a range of nutrients and toxins, compounds altering electron transport, acceptors or donors into the electron transport chain, pH, temperature and even the magnetic field of the Earth. The sensory signals are balanced, and may be balanced with other sensory pathways such as quorum sensing, to identify the optimum current environment. The central sensory pathway in this process is common to most bacteria and most effectors. The environmental change is sensed by a sensory protein. In most species examined this is a transmembrane protein, sensing the external environment, but there is increasing evidence for additional cytoplasmic receptors in many species. All receptors, whether sensing sugars, amino acids or oxygen, share a cytoplasmic signalling domain that controls the activity of a histidine protein kinase, CheA, via a linker protein, CheW. A reduction in an attractant generally leads to the increased autophosphorylation of CheA. CheA passes its phosphate to a small, single domain response regulator, CheY. CheY-P can interact with the flagellar motor to cause it to change rotational direction or stop. Signal termination either via a protein, CheZ, which increases the dephosphorylation rate of CheY-P or via a second CheY which acts as a phosphate sink, allows the cell to swim off again, usually in a new direction. In addition to signal termination the receptor must be reset, and this occurs via methylation of the receptor to return it to a non-signalling conformation. The way in which bacteria use these systems to move to optimum environments and the interaction of the different sensory pathways to produce species-specific behavioural response will be the subject of this review. PMID:10500847

  20. 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...

  1. Regulation of Type III Secretion Hierarchy of Translocators and Effectors in Attaching and Effacing Bacterial Pathogens

    Microsoft Academic Search

    Wanyin Deng; Yuling Li; Philip R. Hardwidge; Elizabeth A. Frey; Richard A. Pfuetzner; Sansan Lee; Samantha Gruenheid; Natalie C. J. Strynakda; Jose L. Puente; B. B. Finlay

    2005-01-01

    Human enteropathogenic Escherichia coli (EPEC), enterohemorrhagic E. coli (EHEC), and the mouse pathogen Citrobacter rodentium (CR) belong to the family of attaching and effacing (A\\/E) bacterial pathogens. They possess the locus of enterocyte effacement (LEE) pathogenicity island, which encodes a type III secretion system. These pathogens secrete a number of proteins into culture media, including type III effector proteins and

  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 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...

  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. High Prevalence of Mycoplasma Infections in Symptomatic (Chronic Fatigue Syndrome) Family Members of Mycoplasma-Positive Gulf War Illness Patients

    Microsoft Academic Search

    Garth L. Nicolson; Marwan Y. Nasralla; Nancy L. Nicolson; Joerg Haier

    2003-01-01

    SUMMARY. Immediate family members of veterans diagnosed with Gulf War Illnesses often complain of fatiguing illnesses, and upon analysis they report similar signs and symptoms as their veteran family members. Since a relatively common finding in Gulf War Illness patients is a bacterial infection due to Mycoplasma species, we examined military families (149 patients: 42 veterans, 40 spouses, 32 other

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

    PubMed Central

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

    2013-01-01

    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

  6. Meningococcal Disease (Bacterial Meningitis) Vaccine and Pregnancy

    MedlinePLUS

    ... or visit us online at: www.OTISpregnancy.org . Meningococcal Disease (Bacterial meningitis) Vaccine and Pregnancy In every pregnancy, a woman ... OTIS at 1-866-626-6847 . Document Outline Meningococcal Disease (Bacterial meningitis) Vaccine and Pregnancy

  7. Subcellular localization of marine bacterial alkaline phosphatases

    E-print Network

    Hu, Jianjun

    Subcellular localization of marine bacterial alkaline phosphatases Haiwei Luoa,1 , Ronald Bennera) Bacterial alkaline phosphatases (APases) are important enzymes in organophosphate utilization in the ocean microorganisms. Alkaline phosphatases (APases) occur in a broad diversity of microorganisms and are important

  8. Transforming Training. Families Matter.

    ERIC Educational Resources Information Center

    Morgan, Gwen

    The Families Matter series of papers from the Harvard Family Research Project advances the concept of family-centered child care, advocating an approach to early childhood education that addresses the development of the child and family together. Grounded in family support principles, which build on family strengths and work from a community's…

  9. 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...

  10. Bacterial Adhesion at Synthetic Surfaces

    Microsoft Academic Search

    D. CUNLIFFE; C. A. SMART; C. ALEXANDER; E. N. VULFSON

    1999-01-01

    A systematic investigation into the effect of surface chemistry on bacterial adhesion was carried out. In particular, a number of physicochemical factors important in defining the surface at the molecular level were assessed for their effect on the adhesion of Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli. The primary experiments involved the grafting of groups varying in hydrophilicity,

  11. 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 ...

  12. Permeability of bacterial cellulose membranes

    Microsoft Academic Search

    Adam M. Sokolnicki; Robert J. Fisher; Timothy P. Harrah; David L. Kaplan

    2006-01-01

    Mass transfer experiments were conducted to determine the transport and interaction parameters of selected molecules in hydrated bacterial cellulose (BC) membranes. The objective was to determine physiochemical characteristics and elucidate the mechanisms governing transport in relation to the membrane structure. Pore and sorption models developed previously for the analysis of transport in hydrogel membranes were relevant to the cellulose membrane

  13. Integrons: agents of bacterial evolution

    Microsoft Academic Search

    Didier Mazel

    2006-01-01

    Integrons are assembly platforms — DNA elements that acquire open reading frames embedded in exogenous gene cassettes and convert them to functional genes by ensuring their correct expression. They were first identified by virtue of their important role in the spread of antibiotic-resistance genes. More recently, our understanding of their importance in bacterial genome evolution has broadened with the discovery

  14. Bacterial Diversity across Individual Lichens? †

    PubMed Central

    Mushegian, Alexandra A.; Peterson, Celeste N.; Baker, Christopher C. M.; Pringle, Anne

    2011-01-01

    Symbioses are unique habitats for bacteria. We surveyed the spatial diversity of bacterial communities across multiple individuals of closely related lichens using terminal restriction fragment length polymorphism (T-RFLP) and pyrosequencing. Centers of lichens house richer, more consistent assemblages than species-poor and compositionally disparate lichen edges, suggesting that ecological succession plays a role in structuring these communities. PMID:21531831

  15. 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...

  16. Family to Family: Reconstructing Foster Care.

    ERIC Educational Resources Information Center

    Annie E. Casey Foundation, Greenwich, CT.

    Family foster care, the mainstay of public child welfare systems, is in critical need of reform. Following a discussion of the efforts of the Annie E. Casey Foundation to assist communities and agencies in confronting this crisis, this paper describes the Family to Family Initiative, a system founded on the view that family foster care reform must…

  17. Insect dissemination of bacterial plant diseases

    Microsoft Academic Search

    A. C. Hayward

    1974-01-01

    Insects can readily spread certain bacterial pathogens as well as make the wound through which infection occurs, but with few exceptions bacterial diseases are not entirely dependent on insects for their dissemination or for the inoculation of the pathogen into the plant tissues. In fireblight of pome fruits caused by Erwinia amylovora pollinating insects are known to carry bacterial ooze

  18. Sequencing and analysis of bacterial genomes

    Microsoft Academic Search

    Eugene V. Koonin; Arcady R. Mushegian; Kenneth E. Rudd

    1996-01-01

    The complete sequences of two small bacterial genomes have recently become available, and those of several more species should follow within the next two years. Sequence comparisons show that the most bacterial proteins are highly conserved in evolution, allowing predictions to be made about the functions of most products of an uncharacterized genome. Bacterial genomes differ vastly in their gene

  19. Helicobacter pylori genome variability in a framework of familial transmission

    Microsoft Academic Search

    Mĺrten Kivi; Sandra Rodin; Ilya Kupershmidt; Annelie Lundin; Ylva Tindberg; Marta Granström; Lars Engstrand

    2007-01-01

    BACKGROUND: Helicobacter pylori infection is exceptionally prevalent and is considered to be acquired primarily early in life through person-to-person transmission within the family. H. pylori is a genetically diverse bacterial species, which may facilitate adaptation to new hosts and persistence for decades. The present study aimed to explore the genetic diversity of clonal isolates from a mother and her three

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

    PubMed Central

    Schöttner, Sandra; Hoffmann, Friederike; Cárdenas, 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

  1. 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

  2. Inhibitors of bacterial tubulin target bacterial membranes in vivo.

    PubMed

    Foss, Marie H; Eun, Ye-Jin; Grove, Charles I; Pauw, Daniel A; Sorto, Nohemy A; Rensvold, Jarred W; Pagliarini, David J; Shaw, Jared T; Weibel, Douglas B

    2013-01-01

    FtsZ is a homolog of eukaryotic tubulin that is widely conserved among bacteria and coordinates the assembly of the cell division machinery. FtsZ plays a central role in cell replication and is a target of interest for antibiotic development. Several FtsZ inhibitors have been reported. We characterized the mechanism of these compounds in bacteria and found that many of them disrupt the localization of membrane-associated proteins, including FtsZ, by reducing the transmembrane potential or perturbing membrane permeability. We tested whether the reported phenotypes of a broad collection of FtsZ inhibitors disrupt the transmembrane potential in Bacillus subtilis strain 168. Using a combination of flow cytometry and microscopy, we found that zantrin Z1, cinnamaldehyde, totarol, sanguinarine, and viriditoxin decreased the B. subtilis transmembrane potential or perturbed membrane permeability, and influenced the localization of the membrane-associated, division protein MinD. These studies demonstrate that small molecules that disrupt membrane function in bacterial cells produce phenotypes that are similar to the inhibition of proteins associated with membranes in vivo, including bacterial cytoskeleton homologs, such as FtsZ. The results provide a new dimension for consideration in the design and testing of inhibitors of bacterial targets that are membrane-associated and provide additional insight into the structural characteristics of antibiotics that disrupt the membrane. PMID:23539337

  3. Inhibitors of bacterial tubulin target bacterial membranes in vivo†

    PubMed Central

    Foss, Marie H.; Eun, Ye-Jin; Grove, Charles I.; Pauw, Daniel A.; Sorto, Nohemy A.; Rensvold, Jarred W.; Pagliarini, David J.; Shaw, Jared T.

    2012-01-01

    FtsZ is a homolog of eukaryotic tubulin that is widely conserved among bacteria and coordinates the assembly of the cell division machinery. FtsZ plays a central role in cell replication and is a target of interest for antibiotic development. Several FtsZ inhibitors have been reported. We characterized the mechanism of these compounds in bacteria and found that many of them disrupt the localization of membrane-associated proteins, including FtsZ, by reducing the transmembrane potential or perturbing membrane permeability. We tested whether the reported phenotypes of a broad collection of FtsZ inhibitors disrupt the transmembrane potential in Bacillus subtilis strain 168. Using a combination of flow cytometry and microscopy, we found that zantrin Z1, cinnamaldehyde, totarol, sanguinarine, and viriditoxin decreased the B. subtilis transmembrane potential or perturbed membrane permeability, and influenced the localization of the membrane-associated, division protein MinD. These studies demonstrate that small molecules that disrupt membrane function in bacterial cells produce phenotypes that are similar to the inhibition of proteins associated with membranes in vivo, including bacterial cytoskeleton homologs, such as FtsZ. The results provide a new dimension for consideration in the design and testing of inhibitors of bacterial targets that are membrane-associated and provide additional insight into the structural characteristics of antibiotics that disrupt the membrane. PMID:23539337

  4. Evolution of a microbial nitrilase gene family: a comparative and environmental genomics study

    Microsoft Academic Search

    Mircea Podar; Jonathan R Eads; Toby H Richardson

    2005-01-01

    BACKGROUND: Completed genomes and environmental genomic sequences are bringing a significant contribution to understanding the evolution of gene families, microbial metabolism and community eco-physiology. Here, we used comparative genomics and phylogenetic analyses in conjunction with enzymatic data to probe the evolution and functions of a microbial nitrilase gene family. Nitrilases are relatively rare in bacterial genomes, their biological function being

  5. 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

  6. Familial Hypercholesterolaemia

    PubMed Central

    Marais, A David

    2004-01-01

    Familial hypercholesterolaemia (FH), defined as the heritable occurrence of severe hypercholesterolaemia with cholesterol deposits in tendons and premature heart disease, is caused by at least four genes in sterol and lipoprotein pathways and displays varying gene-dose effects. The genes are the low-density lipoprotein (LDL) receptor, apolipoprotein (apo) B, proprotein convertase subtilisin/kexin 9, and the autosomal recessive hypercholesterolaemia (ARH) adaptor protein. All of these disorders have in common defective clearance of LDL within a complex system of lipid and lipoprotein metabolism and regulation. Normal cellular cholesterol and lipoprotein metabolism is reviewed before describing the disorders, their metabolic derangements and their clinical effects. FH is classified as two simplified phenotypes of disease according to the severity of the metabolic derangement. The dominantly inherited heterozygous phenotype comprises defects in the LDL receptor, apoB100, and neural apoptosis regulatory cleavage protein. The homozygous phenotype is co-dominant in defects of the LDL receptor, and occurs also as the ARH of adapter protein mutations. Defective binding of apoB100 does not result in a significant gene dose effect, but enhances the severity of heterozygotes for LDL receptor mutations. The genetic diagnosis of FH has provided greater accuracy in definition and detection of disease and exposes information about migration of populations. All of these disorders pose a high risk of atherosclerosis, especially in the homozygous phenotype. Studies of influences on the phenotype and responses to treatment are also discussed in the context of the metabolic derangements. PMID:18516203

  7. Electromagnetic Signals from Bacterial DNA

    E-print Network

    A. Widom; J. Swain; Y. N. Srivastava; S. Sivasubramanian

    2012-02-09

    Chemical reactions can be induced at a distance due to the propagation of electromagnetic signals during intermediate chemical stages. Although is is well known at optical frequencies, e.g. photosynthetic reactions, electromagnetic signals hold true for muck lower frequencies. In E. coli bacteria such electromagnetic signals can be generated by electric transitions between energy levels describing electrons moving around DNA loops. The electromagnetic signals between different bacteria within a community is a "wireless" version of intercellular communication found in bacterial communities connected by "nanowires". The wireless broadcasts can in principle be of both the AM and FM variety due to the magnetic flux periodicity in electron energy spectra in bacterial DNA orbital motions.

  8. 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-Ĺ 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 ?-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

  9. Bacterial degradation of bile salts

    Microsoft Academic Search

    Bodo Philipp

    2011-01-01

    Bile salts are surface-active steroid compounds. Their main physiological function is aiding the digestion of lipophilic nutrients\\u000a in intestinal tracts of vertebrates. Many bacteria are capable of transforming and degrading bile salts in the digestive tract\\u000a and in the environment. Bacterial bile salt transformation and degradation is of high ecological relevance and also essential\\u000a for the biotechnological production of steroid

  10. Curved microchannels and bacterial streamers

    Microsoft Academic Search

    Roberto Rusconi; Sigolene Lecuyer; Laura Guglielmini; Howard Stone

    2010-01-01

    Bacterial biofilms are commonly identified as microbial communities attached to a surface and encased in a self-secreted extracellular matrix. Due to their increased resistance to antimicrobial agents, biofilms have an enormous impact on health and medicine (e.g., wound healing, implant-associated infections, disease transmission). On the other hand, they constitute a major component of the stream ecosystem by increasing transport of

  11. Antibiotic consideration in bacterial vaginosis

    Microsoft Academic Search

    Jack D. Sobel

    2009-01-01

    Bacterial vaginosis (BV) is a syndrome characterized by the loss of indigenous vaginal lactobacilli and massive polymicrobial\\u000a anaerobic vaginal overgrowth of elusive etiology. Although progress has occurred in defining the composition of the vaginal\\u000a microbiome using DNA amplifications, rapidly accumulating data have not resulted in therapeutic advantage. Treatment options\\u000a remain limited and outcome often unsatisfactory, particularly regarding the frequent recurrence

  12. 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

  13. Natural Functions of Bacterial Polyhydroxyalkanoates

    Microsoft Academic Search

    Susana Castro-Sowinski; Saul Burdman; Ofra Matan; Yaacov Okon

    \\u000a Polyhydroxyalkanoates (PHAs) are energy- and intracellular carbon-storage compounds that can be mobilized and used when carbon\\u000a is a limiting resource. Intracellular accumulation of PHA enhances the survival of several bacterial species under environmental\\u000a stress conditions imposed in water and soil, such as UV irradiation, salinity, thermal and oxidative stress, desiccation,\\u000a and osmotic shock. The ability to endure these stresses is

  14. 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

  15. 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

  16. Bacterial strategies for chemotaxis response

    PubMed Central

    Celani, Antonio; Vergassola, Massimo

    2010-01-01

    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

  17. Bacterial motion in narrow capillaries.

    PubMed

    Ping, Liyan; Wasnik, Vaibhav; Emberly, Eldon

    2015-02-01

    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 ?m 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

  18. Dialkylresorcinols as bacterial signaling molecules.

    PubMed

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

    2015-01-13

    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

  19. 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";…

  20. Boston University Family Medicine

    E-print Network

    Spence, Harlan Ernest

    Boston University Family Medicine Global Health CollaborativeFamily Medicine As part of the Department of Family Medicine at Boston University, the Collaborative is committed to introducing and improving Family Medicine programs around the world. Family Medicine is a holistic specialty that attends

  1. 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…

  2. Choosing a Family Doctor

    MedlinePLUS

    ... who takes care of the whole family. Family doctors create caring relationships with patients and their families. They really get know their patients. They listen to them and help them make the right health care decisions. What do family doctors do? Family doctors take care of the physical, ...

  3. Families with Gifted Adolescents

    ERIC Educational Resources Information Center

    Schilling, Susanne R.; Sparfeldt, Jorn; Rost, Detlef H.

    2006-01-01

    Studies of families with gifted adolescents have revealed conflicting results. Adolescents, mothers, and fathers of 84 families with a gifted adolescent and of 95 families with a non-gifted adolescent evaluated their family system independently. Dependent variables were cohesion, democratic family style (adaptability), organisation, achievement…

  4. 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?

  5. 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

  6. Effects of family connection and family individuation.

    PubMed

    Bell, Linda G; Bell, David C

    2009-09-01

    This prospective longitudinal study explores the differential effects of family connection and family individuation measured during adolescence on later midlife well-being. Home interviews were held in the 1970s with 99 families of 245 adolescents. Connection and individuation in the family system were measured by self-report, a projective exercise, and coding of taped family interactions. Twenty-five years later, telephone interviews were conducted with 54 men and 120 women (representing 82 families) who had been adolescents in the 1970s interviews. Family connection (measured during adolescence) was associated with self-acceptance and positive relationships at midlife partially mediated by marriage. Family individuation (measured during adolescence) was associated with personal autonomy at midlife. PMID:19946806

  7. Bioremediation of contaminated marine sediments can enhance metal mobility due to changes of bacterial diversity.

    PubMed

    Fonti, Viviana; Beolchini, Francesca; Rocchetti, Laura; Dell'Anno, Antonio

    2015-01-01

    Bioremediation strategies applied to contaminated marine sediments can induce important changes in the mobility and bioavailability of metals with potential detrimental consequences on ecosystem health. In this study we investigated changes of bacterial abundance and diversity (by a combination of molecular fingerprinting and next generation sequencing analyses) during biostimulation experiments carried out on anoxic marine sediments characterized by high metal content. We provide evidence that the addition of organic (lactose and/or acetate) and/or inorganic compounds to contaminated sediments determines a significant increase of bacterial growth coupled with changes in bacterial diversity and assemblage composition. Experimental systems supplied only with organic substrates were characterized by an increase of the relative importance of sulfate reducing bacteria belonging to the families Desulfobacteraceae and Desulfobulbaceae with a concomitant decrease of taxa affiliated with Flavobacteriaceae. An opposite effect was observed in the experimental treatments supplied also with inorganic nutrients. The increase of bacterial metabolism coupled with the increase of bacterial taxa affiliated with Flavobacteriaceae were reflected in a significant decrease of Cd and Zn associated with sedimentary organic matter and Pb and As associated with the residual fraction of the sediment. However, independently from the experimental conditions investigated no dissolution of metals occurred, suggesting a role of bacterial assemblages in controlling metal solubilization processes. Overall results of this study have allowed to identify key biogeochemical interactions influencing the metal behavior and provide new insights for a better understanding of the potential consequences of bio-treatments on the metal fate in contaminated marine sediments. PMID:25462769

  8. 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

  9. Transient familial hyperbilirubinemia

    MedlinePLUS

    Transient familial hyperbilirubinemia is a metabolic disorder that is passed down through families. Babies with this disorder ... Transient familial hyperbilirubinemia is an inherited disorder. It occurs when the body does not properly break down ( ...

  10. Family Reunion Health Guide

    MedlinePLUS

    ... HEALTH GUIDE 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. ...

  11. Familial lipoprotein lipase deficiency

    MedlinePLUS

    Familial lipoprotein lipase deficiency is a group of rare genetic disorders in which a person lacks a protein needed ... Familial lipoprotein lipase deficiency is caused by a defective gene that is passed down through families. Persons with this ...

  12. 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.

  13. Understanding Fragile Families

    MedlinePLUS

    ... of life for fragile families living in major cities today. The overall aims of Fragile Family are ... 000 couples in 20 of the nation’s largest cities. Of the families that participated in the study, ...

  14. 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 ?-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

  15. Attached Bacterial Populations Shared by Four Species of Aquatic Angiosperms?

    PubMed Central

    Crump, Byron C.; Koch, Evamaria W.

    2008-01-01

    Symbiotic relationships between microbes and plants are common and well studied in terrestrial ecosystems, but little is known about such relationships in aquatic environments. We compared the phylogenetic diversities of leaf- and root-attached bacteria from four species of aquatic angiosperms using denaturing gradient gel electrophoresis (DGGE) and DNA sequencing of PCR-amplified 16S rRNA genes. Plants were collected from three beds in Chesapeake Bay at sites characterized as freshwater (Vallisneria americana), brackish (Potomogeton perfoliatus and Stuckenia pectinata), and marine (Zostera marina). DGGE analyses showed that bacterial communities were very similar for replicate samples of leaves from canopy-forming plants S. pectinata and P. perfoliatus and less similar for replicate samples of leaves from meadow-forming plants Z. marina and V. americana and of roots of all species. In contrast, bacterial communities differed greatly among plant species and between leaves and roots. DNA sequencing identified 154 bacterial phylotypes, most of which were restricted to single plant species. However, 12 phylotypes were found on more than one plant species, and several of these phylotypes were abundant in clone libraries and represented the darkest bands in DGGE banding patterns. Root-attached phylotypes included relatives of sulfur-oxidizing Gammaproteobacteria and sulfate-reducing Deltaproteobacteria. Leaf-attached phylotypes included relatives of polymer-degrading Bacteroidetes and phototrophic Alphaproteobacteria. Also, leaves and roots of three plant species hosted relatives of methylotrophic Betaproteobacteria belonging to the family Methylophilaceae. These results suggest that aquatic angiosperms host specialized communities of bacteria on their surfaces, including several broadly distributed and potentially mutualistic bacterial populations. PMID:18676705

  16. Attached bacterial populations shared by four species of aquatic angiosperms.

    PubMed

    Crump, Byron C; Koch, Evamaria W

    2008-10-01

    Symbiotic relationships between microbes and plants are common and well studied in terrestrial ecosystems, but little is known about such relationships in aquatic environments. We compared the phylogenetic diversities of leaf- and root-attached bacteria from four species of aquatic angiosperms using denaturing gradient gel electrophoresis (DGGE) and DNA sequencing of PCR-amplified 16S rRNA genes. Plants were collected from three beds in Chesapeake Bay at sites characterized as freshwater (Vallisneria americana), brackish (Potomogeton perfoliatus and Stuckenia pectinata), and marine (Zostera marina). DGGE analyses showed that bacterial communities were very similar for replicate samples of leaves from canopy-forming plants S. pectinata and P. perfoliatus and less similar for replicate samples of leaves from meadow-forming plants Z. marina and V. americana and of roots of all species. In contrast, bacterial communities differed greatly among plant species and between leaves and roots. DNA sequencing identified 154 bacterial phylotypes, most of which were restricted to single plant species. However, 12 phylotypes were found on more than one plant species, and several of these phylotypes were abundant in clone libraries and represented the darkest bands in DGGE banding patterns. Root-attached phylotypes included relatives of sulfur-oxidizing Gammaproteobacteria and sulfate-reducing Deltaproteobacteria. Leaf-attached phylotypes included relatives of polymer-degrading Bacteroidetes and phototrophic Alphaproteobacteria. Also, leaves and roots of three plant species hosted relatives of methylotrophic Betaproteobacteria belonging to the family Methylophilaceae. These results suggest that aquatic angiosperms host specialized communities of bacteria on their surfaces, including several broadly distributed and potentially mutualistic bacterial populations. PMID:18676705

  17. PHYSIOLOGICAL RESPONSES TO STRESS IN THE VIBRIONACEAE WILLIAM SOTO1

    E-print Network

    Nishiguchi, Michele

    ) (refer to Table 1.). Numerous species are pathogenic and cause disease in aquatic animals and humans , AND MICHELE K. NISHIGUCHI1 1 New Mexico State University, Department of Biology,Box 30001, MSC 3AF, Las Cruces.5-3% NaCl for optimum growth. Additionally, most species are susceptible to the vibriostatic agent 0

  18. Solanaceae (Nightshade family) Horsenettle

    E-print Network

    Solanaceae (Nightshade family) Horsenettle Solanum carolinense L. Life cycle Spreading to erect to identifying Christmas tree weeds. #12;Solanaceae (Nightshade family) Horsenettle continued Flowers and fruit

  19. Innate immune recognition of bacterial ligands by NAIPs determines inflammasome specificity.

    PubMed

    Kofoed, Eric M; Vance, Russell E

    2011-09-29

    Inflammasomes are a family of cytosolic multiprotein complexes that initiate innate immune responses to pathogenic microbes by activating the caspase 1 protease. Although genetic data support a critical role for inflammasomes in immune defence and inflammatory diseases, the molecular basis by which individual inflammasomes respond to specific stimuli remains poorly understood. The inflammasome that contains the NLRC4 (NLR family, CARD domain containing 4) protein was previously shown to be activated in response to two distinct bacterial proteins, flagellin and PrgJ, a conserved component of pathogen-associated type III secretion systems. However, direct binding between NLRC4 and flagellin or PrgJ has never been demonstrated. A homologue of NLRC4, NAIP5 (NLR family, apoptosis inhibitory protein 5), has been implicated in activation of NLRC4 (refs 7-11), but is widely assumed to have only an auxiliary role, as NAIP5 is often dispensable for NLRC4 activation. However, Naip5 is a member of a small multigene family, raising the possibility of redundancy and functional specialization among Naip genes. Here we show in mice that different NAIP paralogues determine the specificity of the NLRC4 inflammasome for distinct bacterial ligands. In particular, we found that activation of endogenous NLRC4 by bacterial PrgJ requires NAIP2, a previously uncharacterized member of the NAIP gene family, whereas NAIP5 and NAIP6 activate NLRC4 specifically in response to bacterial flagellin. We dissected the biochemical mechanism underlying the requirement for NAIP proteins by use of a reconstituted NLRC4 inflammasome system. We found that NAIP proteins control ligand-dependent oligomerization of NLRC4 and that the NAIP2-NLRC4 complex physically associates with PrgJ but not flagellin, whereas NAIP5-NLRC4 associates with flagellin but not PrgJ. Our results identify NAIPs as immune sensor proteins and provide biochemical evidence for a simple receptor-ligand model for activation of the NAIP-NLRC4 inflammasomes. PMID:21874021

  20. Bacterial Adhesion at Synthetic Surfaces

    PubMed Central

    Cunliffe, D.; Smart, C. A.; Alexander, C.; Vulfson, E. N.

    1999-01-01

    A systematic investigation into the effect of surface chemistry on bacterial adhesion was carried out. In particular, a number of physicochemical factors important in defining the surface at the molecular level were assessed for their effect on the adhesion of Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli. The primary experiments involved the grafting of groups varying in hydrophilicity, hydrophobicity, chain length, and chemical functionality onto glass substrates such that the surfaces were homogeneous and densely packed with functional groups. All of the surfaces were found to be chemically well defined, and their measured surface energies varied from 15 to 41 mJ · m?2. Protein adsorption experiments were performed with 3H-labelled bovine serum albumin and cytochrome c prior to bacterial attachment studies. Hydrophilic uncharged surfaces showed the greatest resistance to protein adsorption; however, our studies also showed that the effectiveness of poly(ethyleneoxide) (PEO) polymers was not simply a result of its hydrophilicity and molecular weight alone. The adsorption of the two proteins approximately correlated with short-term cell adhesion, and bacterial attachment for L. monocytogenes and E. coli also correlated with the chemistry of the underlying substrate. However, for S. aureus and S. typhimurium a different pattern of attachment occurred, suggesting a dissimilar mechanism of cell attachment, although high-molecular-weight PEO was still the least-cell-adsorbing surface. The implications of this for in vivo attachment of cells suggest that hydrophilic passivating groups may be the best method for preventing cell adsorption to synthetic substrates provided they can be grafted uniformly and in sufficient density at the surface. PMID:10543814

  1. Bacterial adhesion at synthetic surfaces.

    PubMed

    Cunliffe, D; Smart, C A; Alexander, C; Vulfson, E N

    1999-11-01

    A systematic investigation into the effect of surface chemistry on bacterial adhesion was carried out. In particular, a number of physicochemical factors important in defining the surface at the molecular level were assessed for their effect on the adhesion of Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli. The primary experiments involved the grafting of groups varying in hydrophilicity, hydrophobicity, chain length, and chemical functionality onto glass substrates such that the surfaces were homogeneous and densely packed with functional groups. All of the surfaces were found to be chemically well defined, and their measured surface energies varied from 15 to 41 mJ. m(-2). Protein adsorption experiments were performed with (3)H-labelled bovine serum albumin and cytochrome c prior to bacterial attachment studies. Hydrophilic uncharged surfaces showed the greatest resistance to protein adsorption; however, our studies also showed that the effectiveness of poly(ethyleneoxide) (PEO) polymers was not simply a result of its hydrophilicity and molecular weight alone. The adsorption of the two proteins approximately correlated with short-term cell adhesion, and bacterial attachment for L. monocytogenes and E. coli also correlated with the chemistry of the underlying substrate. However, for S. aureus and S. typhimurium a different pattern of attachment occurred, suggesting a dissimilar mechanism of cell attachment, although high-molecular-weight PEO was still the least-cell-adsorbing surface. The implications of this for in vivo attachment of cells suggest that hydrophilic passivating groups may be the best method for preventing cell adsorption to synthetic substrates provided they can be grafted uniformly and in sufficient density at the surface. PMID:10543814

  2. 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.

  3. Prevalence of bacterial vaginosis in adolescent girls.

    PubMed

    Pawlaczyk, M; Grys, E

    2001-12-01

    The age-related increase in the prevalence of bacterial vaginosis was determined in adolescent virginal and sexually active girls aged 13 to 18 years. Higher rates were recorded for girls with two or more sexual partners. Considering the potential spectrum of consequences of bacterial vaginosis, preventive strategies are required in this age group, not only for bacterial vaginosis but also for other sexually transmitted diseases. PMID:11879583

  4. 3D Side View of Bacterial Biofilm

    NSDL National Science Digital Library

    American Society For Microbiology

    2002-01-01

    Confocal scanning laser microscopy image of a bacterial biofilm composed of Pseudomonas aeruginosa, Pseudomonas fluorescens, and Klebsiella pneumoniae growing on the wall of a polycarbonate flow cell.

  5. 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

  6. 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

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

    NASA Astrophysics Data System (ADS)

    Dias, Ulisses; Dias, Zanoni; Setubal, Joăo 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. Title: Bacterial Endosymbionts of Leeches Running Title: Bacterial Endosymbionts of Leeches

    E-print Network

    Siddall, Mark E.

    Title: Bacterial Endosymbionts of Leeches Running Title: Bacterial Endosymbionts of Leeches Susan L new lineages of bacterial symbionts of blood-feeding leeches, one from the giant5 Amazonian leech in the literature including alphaproteobacterial symbionts from the leech12 genus Placobdella as well as Aeromonas

  9. Bacterial swimming strategies and turbulence

    PubMed Central

    Luchsinger, RH; Bergersen, B; Mitchell, JG

    1999-01-01

    Most bacteria in the ocean can be motile. Chemotaxis allows bacteria to detect nutrient gradients, and hence motility is believed to serve as a method of approaching sources of food. This picture is well established in a stagnant environment. In the ocean a shear microenvironment is associated with turbulence. This shear flow prevents clustering of bacteria around local nutrient sources if they swim in the commonly assumed "run-and-tumble" strategy. Recent observations, however, indicate a "back-and-forth" swimming behavior for marine bacteria. In a theoretical study we compare the two bacterial swimming strategies in a realistic ocean environment. The "back-and-forth" strategy is found to enable the bacteria to stay close to a nutrient source even under high shear. Furthermore, rotational diffusion driven by thermal noise can significantly enhance the efficiency of this strategy. The superiority of the "back-and-forth" strategy suggests that bacterial motility has a control function rather than an approach function under turbulent conditions. PMID:10545341

  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. 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

  12. Immunization by a bacterial aerosol.

    PubMed

    Garcia-Contreras, Lucila; Wong, Yun-Ling; Muttil, Pavan; Padilla, Danielle; Sadoff, Jerry; Derousse, Jessica; Germishuizen, Willem Andreas; Goonesekera, Sunali; Elbert, Katharina; Bloom, Barry R; Miller, Rich; Fourie, P Bernard; Hickey, Anthony; Edwards, David

    2008-03-25

    By manufacturing a single-particle system in two particulate forms (i.e., micrometer size and nanometer size), we have designed a bacterial vaccine form that exhibits improved efficacy of immunization. Microstructural properties are adapted to alter dispersive and aerosol properties independently. Dried "nanomicroparticle" vaccines possess two axes of nanoscale dimensions and a third axis of micrometer dimension; the last one permits effective micrometer-like physical dispersion, and the former provides alignment of the principal nanodimension particle axes with the direction of airflow. Particles formed with this combination of nano- and micrometer-scale dimensions possess a greater ability to aerosolize than particles of standard spherical isotropic shape and of similar geometric diameter. Here, we demonstrate effective application of this biomaterial by using the live attenuated tuberculosis vaccine bacille Calmette-Guérin (BCG). Prepared as a spray-dried nanomicroparticle aerosol, BCG vaccine exhibited high-efficiency delivery and peripheral lung targeting capacity from a low-cost and technically simple delivery system. Aerosol delivery of the BCG nanomicroparticle to normal guinea pigs subsequently challenged with virulent Mycobacterium tuberculosis significantly reduced bacterial burden and lung pathology both relative to untreated animals and to control animals immunized with the standard parenteral BCG. PMID:18344320

  13. Immunization by a bacterial aerosol

    PubMed Central

    Garcia-Contreras, Lucila; Wong, Yun-Ling; Muttil, Pavan; Padilla, Danielle; Sadoff, Jerry; DeRousse, Jessica; Germishuizen, Willem Andreas; Goonesekera, Sunali; Elbert, Katharina; Bloom, Barry R.; Miller, Rich; Fourie, P. Bernard; Hickey, Anthony; Edwards, David

    2008-01-01

    By manufacturing a single-particle system in two particulate forms (i.e., micrometer size and nanometer size), we have designed a bacterial vaccine form that exhibits improved efficacy of immunization. Microstructural properties are adapted to alter dispersive and aerosol properties independently. Dried “nanomicroparticle” vaccines possess two axes of nanoscale dimensions and a third axis of micrometer dimension; the last one permits effective micrometer-like physical dispersion, and the former provides alignment of the principal nanodimension particle axes with the direction of airflow. Particles formed with this combination of nano- and micrometer-scale dimensions possess a greater ability to aerosolize than particles of standard spherical isotropic shape and of similar geometric diameter. Here, we demonstrate effective application of this biomaterial by using the live attenuated tuberculosis vaccine bacille Calmette–Guérin (BCG). Prepared as a spray-dried nanomicroparticle aerosol, BCG vaccine exhibited high-efficiency delivery and peripheral lung targeting capacity from a low-cost and technically simple delivery system. Aerosol delivery of the BCG nanomicroparticle to normal guinea pigs subsequently challenged with virulent Mycobacterium tuberculosis significantly reduced bacterial burden and lung pathology both relative to untreated animals and to control animals immunized with the standard parenteral BCG. PMID:18344320

  14. 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…

  15. Traceability for system families

    Microsoft Academic Search

    Detlef Streitferdt

    2001-01-01

    System families are an idea of software reuse in a specific problem domain. Existing methods have little requirements engineering support for system family development. This short paper proposes a requirements metamodel for system family development. Traceability throughout model elements is a necessary precondition for preserving the consistency of the complete family model during development and is a main issue in

  16. FAMILY MEDICINE* Definition Of

    E-print Network

    Finley Jr., Russell L.

    FAMILY MEDICINE* Definition Of Family medicine is the medical specialty which provides continuing the biological, clinical and behavioral sciences. The scope of family medicine encompasses all ages, both sexes, each organ system and every disease entity. (1986) (2003) Quality Healthcare In Family Medicine Quality

  17. Family Participation in Policymaking.

    ERIC Educational Resources Information Center

    Caplan, Elizabeth, Ed.; Blankenship, Kelly, Ed.; McManus, Marilyn, Ed.

    1998-01-01

    This bulletin focuses on family participation in mental health policymaking and highlights state efforts to increase family involvement. Articles include: (1) "Promoting Family Member Involvement in Children's Mental Health Policy Making Bodies," which describes how different states are promoting family member involvement in various statutory and…

  18. Families in Transition .

    ERIC Educational Resources Information Center

    Bundy, Michael L., Ed.; Gumaer, James, Ed.

    1984-01-01

    Focuses on disrupted families and the role of the school counselor in helping children adjust. Describes characteristics of healthy families, and discusses the transition to the blended family, effects of divorce groups on children's classroom behavior, counseling children in stepfamilies, single-parent families, and parenting strengths of single…

  19. 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

  20. 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

  1. 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...

  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. Detection of quantitative trait loci (QTL) for resistance to bacterial cold water disease and spleen size 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...

  4. Bacterial diversity in a marine methanol-fed denitrification reactor at the montreal biodome, Canada.

    PubMed

    Labbé, N; Juteau, P; Parent, S; Villemur, R

    2003-07-01

    The bacterial biota of a methanol-fed denitrification reactor used to treat seawater at the Montreal Biodome were investigated using culture-dependent and molecular biology methods. The microbiota extracted from the reactor carriers were cultivated on three media. Three isolate types were recovered and their 16S ribosomal DNA (rDNA) genes were determined. The analysis showed that the isolate types were related to alpha-Proteobacteria. They are members of the Hyphomicrobium and Paracoccus genera and the Phyllobacteriaceae family. Uncultured bacteria were identified through a 16S rDNA library generated from total DNA extracted from the microbiota. Clones were screened for different restriction profiles and for different DGGE (denaturing gradient gel electrophoresis) migration profiles. More than 70% of clones have the same restriction profile, and the sequence of representative clones showed a relation with the Methylophaga members of the Piscirickettsia family (gamma-Proteobacteria). Sequences from other profiles were related to bacterial species involved in denitrification. The number of species in the denitrification reactor was estimated at 15. Bacterial colonization on newly added carriers in the denitrification reactor was monitored by PCR-DGGE. The DGGE migration profiles evolved during the first 5 weeks and then remained essentially unchanged. PCR-DGGE was also used to monitor the microbial profiles in various aquarium locations. As expected, bacterial populations differed from one location to another, except for the sand and trickling filters which presented similar DGGE migration profiles. PMID:12739074

  5. Composition, uniqueness and variability of the epiphytic bacterial community of the green alga Ulva australis

    PubMed Central

    Burke, Catherine; Thomas, Torsten; Lewis, Matt; Steinberg, Peter; Kjelleberg, Staffan

    2011-01-01

    Green Ulvacean marine macroalgae are distributed worldwide in coastal tidal and subtidal ecosystems. As for many living surfaces in the marine environment, little is known concerning the epiphytic bacterial biofilm communities that inhabit algal surfaces. This study reports on the largest published libraries of near full-length 16S rRNA genes from a marine algal surface (5293 sequences from six samples) allowing for an in-depth assessment of the diversity and phylogenetic profile of the bacterial community on a green Ulvacean alga. Large 16S rRNA gene libraries of surrounding seawater were also used to determine the uniqueness of this bacterial community. The surface of Ulva australis is dominated by sequences of Alphaproteobacteria and the Bacteroidetes, especially within the Rhodobacteriaceae, Sphingomonadaceae, Flavobacteriaceae and Sapropiraceae families. Seawater libraries were also dominated by Alphaproteobacteria and Bacteroidetes sequences, but were shown to be clearly distinct from U. australis libraries through the clustering of sequences into operational taxonomic units and Bray–Curtis similarity analysis. Almost no similarity was observed between these two environments at the species level, and only minor similarity was observed at levels of sequence clustering representing clades of bacteria within family and genus taxonomic groups. Variability between libraries of U. australis was relatively high, and a consistent sub-population of bacterial species was not detected. The competitive lottery model, originally derived to explain diversity in coral reef fishes, may explain the pattern of colonization of this algal surface. PMID:21048801

  6. Leading Edge Bacterial Genomics and Pathogen Evolution

    E-print Network

    Mekalanos, John

    Leading Edge Review Bacterial Genomics and Pathogen Evolution David M. Raskin,1 Rekha Seshadri,2 Medical School, Boston, MA 02115, USA 2 The Institute for Genomic Research, 9712 Medical Center Drive.02.002 The availability of hundreds of bacterial genome sequences has altered the study of bacte- rial pathogenesis

  7. Chronic bacterial infections: living with unwanted guests

    Microsoft Academic Search

    Douglas Young; Tracy Hussell; Gordon Dougan

    2002-01-01

    Some bacterial pathogens can establish life-long chronic infections in their hosts. Persistence is normally established after an acute infection period involving activation of both the innate and acquired immune systems. Bacteria have evolved specific pathogenic mechanisms and harbor sets of genes that contribute to the establishment of a persistent lifestyle that leads to chronic infection. Persistent bacterial infection may involve

  8. 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

  9. Bacterial Production Lab State variables and processes

    E-print Network

    Vallino, Joseph J.

    (125I) 60 d Types Helium nuclei Electron Gamma ray For bacterial production, 3H and 14C used. NoteBacterial Production Lab State variables and processes BDOM Other compounds (e.g., EtOH) CO2 G (also called bacteria production) B DOM DIN Z Time Concentration B Z DOM DIN Turnover: [B]/G U State Var

  10. Bacterial Production Lab State variables and processes

    E-print Network

    Vallino, Joseph J.

    Bacterial Production Lab State variables and processes BDOM Other compounds (e.g., EtOH) CO2 r (also called bacteria production) B DOM DIN G Time Concentration B G DOM DIN Turnover: [B]/rB U StateI) 8.06 d , Iodine-125 (125I) 60 d Types Helium nuclei Electron Gamma ray For bacterial

  11. Bacterial Production Lab State variables and processes

    E-print Network

    Vallino, Joseph J.

    Helium nuclei Electron Gamma ray For bacterial production, 3H and 14C used. Note, 3H and 14C are weakBacterial Production Lab State variables and processes BDOM Other compounds (e.g., EtOH) CO2 r (also called bacteria production) B DOM DIN G Time Concentration B G DOM DIN Turnover: [B]/rB U State

  12. Cognitive outcome in adults after bacterial meningitis

    Microsoft Academic Search

    M. Hoogman; D. van de Beek; M. Weisfelt; J. de Gans; B. A. Schmand

    2007-01-01

    OBJECTIVE: To evaluate cognitive outcome in adult survivors of bacterial meningitis. METHODS: Data from three prospective multicentre studies were pooled and reanalysed, involving 155 adults surviving bacterial meningitis (79 after pneumococcal and 76 after meningococcal meningitis) and 72 healthy controls. RESULTS: Cognitive impairment was found in 32% of patients and this proportion was similar for survivors of pneumococcal and meningococcal

  13. [Aerosol disinfection of bacterial spores].

    PubMed

    Theilen, U; Wilsberg, F J; Böhm, R; Strauch, D

    1987-06-01

    The present investigations are divided into two parts. First it is tested which commercial disinfectants are efficient in aerosol disinfection of bacterial spores. This part is carried out in an aerosol chamber with airborne spores (laboratory experiments). The best results are obtained with peracetic acid, hydrogen peroxide and formaldehyde are effective with some restrictions. With these disinfectants it is tested in the second part if the aerosol disinfecting-method is capable for disinfecting rooms with electronic equipment. This part is carried out in a vessel under open air conditions (field experiments). Bacterial spores dried on germ carriers of limewood, aluminium and rusty iron are exposed to disinfectant aerosols under those temperature and relative humidity conditions which are representative for the four seasons in Germany. In these investigations there are also included germ carriers with spores, that have been lyophilized without any protective substances respectively with Bentonite, Mixtura desiccans and Silicagel + Serum as protective substances. To check the corrosive effect of disinfectant aerosols electronic pocket calculators and pocket transistor receivers have been exposed to the aerosols. The best results are obtained with formaldehyde at temperatures above 10 degrees C and relative humidities within 65% to 95%. At temperatures and relative humidity conditions outside of this optimal range the effectiveness of formaldehyde tends to zero. Hydrogen peroxide is capable for disinfecting spores on germ carriers of limewood and aluminium at all temperature and relative humidity conditions; on germ carriers of rusty iron the effectiveness is reduced strongly. Same results could be obtained with peracetic acid respectively a mixture of peracetic acid and hydrogen peroxide. With these disinfectants a decontamination of rusty iron surfaces is impossible too except the germ concentration on the surface is below 10(4) CFU/cm2. As to the protective substances used in the lyophilization process Bentonite and Mixtura desiccans cause hardly any change in the disinfectant resistance of bacterial spores. Silicagel + Serum in comparison to that protects the imbedded spores that far, that no disinfection of these germ carriers was achieved with the oxidizing agents. As about 15 disinfection runs with each disinfectant did not cause permanent damages to the pocket calculators and transistor receivers it can be emphasized as result of these investigations that aerosol disinfection is an effective method in disinfecting rooms with electronic equipment under middle European climate conditions.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3116785

  14. Structural Biology of Bacterial RNA Polymerase

    PubMed Central

    Murakami, Katsuhiko S.

    2015-01-01

    Since its discovery and characterization in the early 1960s (Hurwitz, J. The discovery of RNA polymerase. J. Biol. Chem. 2005, 280, 42477–42485), an enormous amount of biochemical, biophysical and genetic data has been collected on bacterial RNA polymerase (RNAP). In the late 1990s, structural information pertaining to bacterial RNAP has emerged that provided unprecedented insights into the function and mechanism of RNA transcription. In this review, I list all structures related to bacterial RNAP (as determined by X-ray crystallography and NMR methods available from the Protein Data Bank), describe their contributions to bacterial transcription research and discuss the role that small molecules play in inhibiting bacterial RNA transcription. PMID:25970587

  15. Bacterial 1,3-1,4-?-glucanases: structure, function and protein engineering

    Microsoft Academic Search

    Antoni Planas

    2000-01-01

    1,3-1,4-?-Glucanases (or lichenases, EC 3.2.1.73) hydrolyse linear ?-glucans containing ?-1,3 and ?-1,4 linkages such as cereal ?-glucans and lichenan, with a strict cleavage specificity for ?-1,4 glycosidic bonds on 3-O-substituted glucosyl residues. The bacterial enzymes are retaining glycosyl hydrolases of family 16 with a jellyroll ?-sandwich fold and a substrate binding cleft composed of six subsites. The present paper reviews

  16. NLR-mediated control of inflammasome assembly in the host response against bacterial pathogens

    Microsoft Academic Search

    Igor E. Brodsky; Denise Monack

    2009-01-01

    The host response against diverse bacterial pathogens involves activation of specialized immune cells and elaboration of pro-inflammatory cytokines that help to coordinate appropriate host defense. Members of the interleukin-1 (IL-1) cytokine family, IL-1? and IL-18, are central players in this process. Extracellular release of the mature, active form of these cytokines requires their processing by the cysteine protease caspase-1, which

  17. Role of the Active Site Cysteine of DpgA, a Bacterial Type III Polyketide Synthase †

    Microsoft Academic Search

    Claire C. Tseng; Shaun M. McLoughlin; Neil L. Kelleher; Christopher T. Walsh

    2004-01-01

    DpgA is a bacterial type III polyketide synthase (PKS) that decarboxylates and condenses four malonyl-CoA molecules to produce 3,5-dihydroxyphenylacetyl-CoA (DPA-CoA) in the biosynthetic pathway to 3,5-dihydroxyphenylglycine, a key nonproteinogenic residue in the vancomycin family of antibiotics. DpgA has the conserved catalytic triad of Cys\\/His\\/Asn typical of type III PKS enzymes, and has been assumed to use Cys160 as the catalytic

  18. Dps proteins, an efficient detoxification and DNA protection machinery in the bacterial response to oxidative stress

    Microsoft Academic Search

    Emilia Chiancone

    2008-01-01

    The proteins belonging to the Dps (DNA-binding proteins from starved cells) family play an important role within the bacterial defence system against oxidative stress. They act on Fe(II)\\u000a and hydrogen peroxide that are potentially toxic in the presence of air. Fe(II) forms spontaneously insoluble Fe(III) and\\u000a reacts with molecular oxygen or its reduced forms to yield the highly damaging hydroxyl

  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. 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.

  1. 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

  2. Bacterial diseases of the skin.

    PubMed

    Edlich, Richard F; Winters, Kathryne L; Britt, L D; Long, William B

    2005-01-01

    When considering common bacterial diseases of the skin, rather distinct clinical responses to a variety of bacterial infections have been identified. In these cases, it is the specific site of infection and the attendant inflammatory responses that provide the characteristic clinical picture. When the pyoderma extends just below the stratum corneum, it is called impetigo. Nonbullous impetigo is the most common pediatric skin infection. It usually starts in a traumatized area. The typical lesion begins as an erythematous papule, after which it becomes a unilocular vesicle. When the subcorneal vesicle becomes pustular, it ruptures and eventually becomes a yellow, golden crust that is a hallmark of the disease process. Bullous impetigo is a less common form of impetigo, accounting for fewer than 30% of all impetigo cases. It occurs in infants and is characterized by rapid progression of vesicles to the formation of bullae measuring larger than 5 mm in diameter in previously untraumatized skin. Treatment of nonbullous impetigo must include intervention against the pathogen as well as improvements in the hygiene and living conditions of the patient. A fundamental tenet is to debride the crust (scab) from the wound surface using poloxamer 188. If the lesions are not widespread, topical mupirocin is the treatment of choice. Treatment of bullous impetigo is similar, except that the local cleansing and topical antibiotic must be complemented by systemic antibiotics if there is evidence of disseminating infections. Ecthyma is usually a consequence of failure to treat effectively impetigo. The untreated infection extends deep into the tissue in shallow ulcerations that often heal without scar. Treatment for ecthyma usually requires systemic antibiotics against either staphylococcus or streptococcus. Folliculitis is a pyoderma located within a hair follicle, secondary to follicular occlusion by keratin, overhydration, or either bacterial or fungal infection. Folliculitis may be divided into either a deep or a superficial type. In the superficial type, the pustule is located at the opening of the hair follicle. In the deep form, the infection may extend beyond the confines of the hair follicle, becoming a furuncle or boil. Carbuncles are aggregates of interconnected furuncles that drain through multiple openings of the skin. Treatment of folliculitis must include searching for and avoiding any factors predisposing to infection. If topical antibiotic therapy is ineffective in controlling the infection, surgical drainage of the infected skin abscess will be necessary. Paronychia is the most common bacterial infection of the hand, which often requires surgical incisional drainage. Similarly, a felon that is an infection of the distal pulp of a finger usually requires surgical drainage. Finally, cellulitis is an acute inflammatory reaction involving the skin and underlying subcutaneous tissue. It usually starts as erysipelas and may advance to lymphangitis, lymphadenitis, or gangrene,which will respond to life-saving interventions in the hospital that usually include systemic antibiotic treatment as well as surgical intervention. PMID:16218899

  3. 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

  4. 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

  5. PERMEABILITY OF BACTERIAL SPORES II.

    PubMed Central

    Gerhardt, Philipp; Black, S. H.

    1961-01-01

    Gerhardt, Philipp (University of Michigan, Ann Arbor) and S. H. Black. Permeability of bacterial spores. II. Molecular variables affecting solute permeation. J. Bacteriol. 82:750–760. 1961.—More than 100 compounds were tested for their uptake by dormant spores of a bacillus. The extent of penetration was found to be dependent on at least three molecular properties: (i) The dissociation of electrolytes usually resulted in high or low uptake predictable from their charge. (ii) Lipid insolubility restricted permeation of small molecules. (iii) The molecular weight of unsubstituted glycol and sugar polymers exponentially limited penetration to eventual exclusion at mol wt above 160,000. The results were plotted as a generalized curve, calculations from which permitted an interpretation that the effective spore surface contains pores varying in diameter from 10 to 200 A. PMID:13897940

  6. 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

  7. Bacterial collagen-like proteins that form triple-helical structures

    PubMed Central

    Yu, Zhuoxin; An, Bo; Ramshaw, John A.M.; Brodsky, Barbara

    2014-01-01

    A large number of collagen-like proteins have been identified in bacteria during the past ten years, principally from analysis of genome databases. These bacterial collagens share the distinctive Gly-Xaa-Yaa repeating amino acid sequence of animal collagens which underlies their unique triple-helical structure. A number of the bacterial collagens have been expressed in E. coli, and they all adopt a triple-helix conformation. Unlike animal collagens, these bacterial proteins do not contain the post-translationally modified amino acid, hydroxyproline, which is known to stabilize the triple-helix structure and may promote self-assembly. Despite the absence of collagen hydroxylation, the triple-helix structures of the bacterial collagens studied exhibit a high thermal stability of 35–39 °C, close to that seen for mammalian collagens. These bacterial collagens are readily produced in large quantities by recombinant methods, either in the original amino acid sequence or in genetically manipulated sequences. This new family of recombinant, easy to modify collagens could provide a novel system for investigating structural and functional motifs in animal collagens and could also form the basis of new biomedical materials with designed structural properties and functions. PMID:24434612

  8. 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

  9. 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

  10. 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

  11. Family assessment: Centripetal and centrifugal family systems

    Microsoft Academic Search

    Martha Kelsey-smith; W. Robert Beavers M. D

    1981-01-01

    A consideration of interactional style is useful to both researchers and clinicians interested in family assessment. This paper offers data and process evaluation scales designed to determine family interactional style, conceptualized as a continuum ranging from centripetal (CP) to centrifugal (CF), and containing at the midpoint a mixed area in which facets of both the CP and the CF styles

  12. Family Literacy for Family-Oriented People.

    ERIC Educational Resources Information Center

    Mountainbird, Pauline

    A Massachusetts family literacy project, the Northampton Family Literacy Project, is described, in which adult English-as-a-Second-Language (ESL) learners enrolled in a community educational center in order to learn English as their children enrolled in a child care program at the local library. Both groups were involved in language activities,…

  13. 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

  14. Family psychology and family therapy: Comparisons and contrasts

    Microsoft Academic Search

    Luciano Labate

    1992-01-01

    This paper distinguishes between family psychology as a still nonexistent academic discipline and family therapy as a profession and as a method of intervention. Family psychology is interested in the whole functionality-dysfunctionality continuum, while family therapy is mainly concerned with dysfunctionalities. While family psychology focuses reductionistically on the relationship of the individual within the family, family therapy focuses holistically on

  15. Chronic stimulation of Nod2 mediates tolerance to bacterial products

    PubMed Central

    Hedl, Matija; Li, Jing; Cho, Judy H.; Abraham, Clara

    2007-01-01

    The Toll-like receptor (TLR) and nucleotide-binding oligomerization domain (Nod) families of proteins are critical for bacterial recognition, and, acutely, this frequently leads to proinflammatory responses. Polymorphisms in Nod2 (CARD 15) are associated with an increased likelihood of developing Crohn's disease. However, it is not yet clear how Nod2 dysfunctions lead to defects in human intestinal immune homeostasis. Studies to date have focused on functions after acute, rather than chronic, Nod2 stimulation. However, the intestine is an environment of chronic bacterial product exposure with tolerance to luminal flora. We therefore hypothesized that long-term Nod2 stimulation contributes to down-regulation of inflammatory responses from innate immune receptors. We found that pretreatment with muramyl dipeptide (MDP), a ligand for Nod2, significantly decreased production of the proinflammatory cytokines TNF-?, IL-8, and IL-1? upon Nod2, TLR4, and TLR2 restimulation in primary human monocyte-derived macrophages from a large cohort of individuals. Importantly, TNF-?-induced production of proinflammatory cytokines remained intact in these same cells. MDP-stimulated macrophages from Crohn's disease-relevant Leu1007insC Nod2 homozygote individuals were deficient in their ability to cross-tolerize to subsequent treatment with TLR2 and TLR4 ligands. We show that acute Nod2 stimulation induced IRAK-1 activation, and that chronic MDP treatment down-regulated IRAK-1 activation upon Nod2 or TLR4 restimulation. In a subset of individuals, chronic Nod2 stimulation induced expression of the IRAK-1 inhibitory protein IRAK-M. Significantly, intestinal macrophages exhibit tolerance to MDP per production of inflammatory cytokines. These results illustrate a role for chronic stimulation of Nod2 in mediating tolerance to bacterial products. PMID:18032608

  16. 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

  17. Reactive oxygen species-mediated bacterial killing by B lymphocytes.

    PubMed

    Kovács, István; Horváth, Magdolna; Lányi, Árpád; Pethe?, Gábor L; Geiszt, Miklós

    2015-06-01

    Regulated production of ROS is mainly attributed to Nox family enzymes. In neutrophil granulocytes and macrophages, Nox2 has a crucial role in bacterial killing, and the absence of phagocytic ROS production leads to the development of CGD. Expression of Nox2 was also described in B lymphocytes, where the role of the enzyme is still poorly understood. Here, we show that peritoneal B cells, which were shown recently to possess phagocytic activity, have a high capacity to produce ROS in a Nox2-dependent manner. In phagocytosing B cells, intense intraphagosomal ROS production is detected. Finally, by studying 2 animal models of CGD, we demonstrate that phagocyte oxidase-deficient B cells have a reduced capacity to kill bacteria. Our observations extend the number of immune cell types that produce ROS to kill pathogens. PMID:25821233

  18. 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

  19. 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.

  20. 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)

  1. Contacting My Donor Family

    MedlinePLUS

    ... Donor Family Newsroom Minorities Contacting My Donor Family Writing anything can be a challenge. Staring at a ... can take to get started. The process of writing your letter may take some time, but at ...

  2. About Familial Pulmonary Fibrosis

    MedlinePLUS

    ... or sibling) have the diagnosis of an Idiopathic Interstitial Pneumonia (IIP) and at least one of the family members has the most common form of IIP, Idiopathic Pulmonary Fibrosis (IPF). However, family members can be second degree ...

  3. Family Issues for the Nineties.

    ERIC Educational Resources Information Center

    Mirabelli, Alan

    This presentation reviews the characteristics of the Canadian family at present. Discussion focuses on divorce, family structure, reproductive technology, fertility, family size, family mobility, family support, government role, women's participation in the labor force, daily family routines, television viewing, work and the family, the need for…

  4. Gender in family therapy supervision

    Microsoft Academic Search

    Thorana S. Nelson

    1991-01-01

    While gender has taken its place as a fundamental construct in family therapy theory, little has been written about gender in family therapy supervision. This paper attempts to redefine gender as it pertains to families, family therapy, and family therapy supervision; call attention to aspects of gender as they apply to training in family therapy and family therapy supervision; and

  5. Biochemistry of Bacterial Multidrug Efflux Pumps

    PubMed Central

    Kumar, Sanath; Varela, Manuel F.

    2012-01-01

    Bacterial pathogens that are multi-drug resistant compromise the effectiveness of treatment when they are the causative agents of infectious disease. These multi-drug resistance mechanisms allow bacteria to survive in the presence of clinically useful antimicrobial agents, thus reducing the efficacy of chemotherapy towards infectious disease. Importantly, active multi-drug efflux is a major mechanism for bacterial pathogen drug resistance. Therefore, because of their overwhelming presence in bacterial pathogens, these active multi-drug efflux mechanisms remain a major area of intense study, so that ultimately measures may be discovered to inhibit these active multi-drug efflux pumps. PMID:22605991

  6. Bacterial responses to photo-oxidative stress

    PubMed Central

    Ziegelhoffer, Eva C.; Donohue, Timothy J.

    2009-01-01

    Singlet oxygen is one of several reactive oxygen species that can destroy biomolecules, microorganisms and other cells. Traditionally, the response to singlet oxygen has been termed photo-oxidative stress, as light-dependent processes in photosynthetic cells are major biological sources of singlet oxygen. Recent work identifying a core set of singlet oxygen stress response genes across various bacterial species highlights the importance of this response for survival by both photosynthetic and non-photosynthetic cells. Here, we review how bacterial cells mount a transcriptional response to photo-oxidative stress in the context of what is known about bacterial stress responses to other reactive oxygen species. PMID:19881522

  7. Restorying family therapy

    Microsoft Academic Search

    Shlomo Ariel

    1996-01-01

    This article describes a multi-systemic model of therapy developed by the author over the past decade and summarizes the main products of this project: Explication of key family systems notions, strategic family play therapy, multi-systemic therapy, and culturally-competent family therapy. The model incorporates beyond the family system, culture, wider ecosystems, psychodynamics, and the individual's neuropsychological, cognitive, and socio-emotional development. The

  8. Family Systems Theory

    Microsoft Academic Search

    Stephen M. Gavazzi

    \\u000a Family systems theory provides users with a holistic framework that centers attention on the interactive and bidirectional\\u000a nature of relationships within families with adolescents. The family systems framework enjoys widespread use in the family\\u000a intervention literature, as well as having been increasingly employed within the child and adolescent developmental literatures.\\u000a In the present chapter, attention is paid to a number

  9. Family Outcomes: Policy & Practice

    E-print Network

    Zuna, Nina

    2005-05-05

    Government Performance and Results Act (1993) APR Program goal: Enhance the development of infants and toddlers (0-3) with disabilities and support their families in meeting their special needs 1 Family Indicator: The percentage of families participating... Kansas Division of Early Childhood February 24, 2005 Family Outcomes: Policy & Practice Jean Ann Summers PhD, Beach Center on Disability Nina Zuna Doctoral Student, Beach Center on Disability Kerry Lida Doctoral Student, Beach Center...

  10. The sodium\\/glucose cotransport family SLC5

    Microsoft Academic Search

    Ernest M. Wright; Eric Turk

    2004-01-01

    The sodium\\/glucose cotransporter family (SLCA5) has 220 or more members in animal and bacterial cells. There are 11 human genes expressed in tissues ranging from epithelia to the central nervous system. The functions of nine have been revealed by studies using heterologous expression systems: six are tightly coupled plasma membrane Na +\\/substrate cotransporters for solutes such as glucose, myo-inositol and

  11. Graduate School INTERNATIONAL FAMILY

    E-print Network

    Stuart, Steven J.

    to generate, diffuse, and apply knowledge needed to strengthen communities' capacity for family support graduates as (1) scholars in interdisciplinary institutes or academic departments on child and family rights as applied to children and families around the world, the program builds a comparative

  12. 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…

  13. The Family Farm Project

    NSDL National Science Digital Library

    1996-01-01

    Kenyon College's Family Farm Project, "a three-year study exploring family farming and community life in Knox County, Ohio," presents an intimate multimedia view of the daily life of the family farm, which some consider a vanishing institution in America.

  14. Family Violence: Intervention Strategies.

    ERIC Educational Resources Information Center

    Barnett, Ellen R.; And Others

    Problems related to family violence are complex and multi-faceted and involve large numbers of people in this country. A number of types of violence in families are identified initially; however, the manual focuses on the concerns of battered women, or interspousal abuse. Information focuses on: (1) the nature, causes and effects of family

  15. 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…

  16. 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…

  17. 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)

  18. Families and Fragile Syndrome

    E-print Network

    Rau, Don C.

    Health and Human Development (NICHD) family album about Fragile X syndrome. As a health research agency is designed to give you and your family some general information about Fragile X syndrome, its causes, its or actors. They are individuals with Fragile X syndrome and their families. Through these images, you'll see

  19. Valuing Families. Activity Guide.

    ERIC Educational Resources Information Center

    Glashagel, Jerry; Glashagel, Char

    Developed as a resource for family life education, this activity guide can be used to lead experiential learning situations for intergenerational groups by a counselor, in a course, in a family organization like the YMCA, or in the home. The goals of this guide are to increase the self-esteem of each person and to strengthen the family as a human…

  20. Explorations in Family Policy

    ERIC Educational Resources Information Center

    Kamerman, Sheila B.; Kahn, Alfred J.

    1976-01-01

    Despite a national ideology that the formulation of a family policy would represent unacceptable government intervention, recognition is growing that no modern industrial society can avoid policies that affect the family. The real choice is between a deliberate, coherent family policy and one of inconsistency and mischance. (Author)

  1. Employment Characteristics of Families

    NSDL National Science Digital Library

    The Bureau of Labor Statistics site offers data on the employment characteristics of American families. The statistics include data on employment and unemployment in families by race, relationship, sex, marital status, presence of children in the family, and presence of children under three, among others. The data can be accessed from a table of contents or reviewed in an extensive news release.

  2. 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…

  3. [Phylogenetic analysis of alpha-galactosidases of the GH27 family].

    PubMed

    Naumov, D G

    2004-01-01

    Amino acid sequence analysis of alpha-galactosidases and other proteins of glycoside hydrolase family 27 (GH27) allowed isolation of three major subfamilies, 27a-27c. Unique isomalto-dextranase of Arthrobacter globiformis clustered separately. Eukaryotic proteins formed five clusters on a phylogenetic tree of the family. Bacterial GH27 proteins, which are relatively few, did not form stable clusters. A monophyletic origin of the GH27 family was demonstrated with the use of related proteins of the GH36 family. The structure of the active center and evolution of alpha-galactosidases are discussed. PMID:15285616

  4. Molecular biology of bacterial bioluminescence.

    PubMed Central

    Meighen, E A

    1991-01-01

    The cloning and expression of the lux genes from different luminescent bacteria including marine and terrestrial species have led to significant advances in our knowledge of the molecular biology of bacterial bioluminescence. All lux operons have a common gene organization of luxCDAB(F)E, with luxAB coding for luciferase and luxCDE coding for the fatty acid reductase complex responsible for synthesizing fatty aldehydes for the luminescence reaction, whereas significant differences exist in their sequences and properties as well as in the presence of other lux genes (I, R, F, G, and H). Recognition of the regulatory genes as well as diffusible metabolites that control the growth-dependent induction of luminescence (autoinducers) in some species has advanced our understanding of this unique regulatory mechanism in which the autoinducers appear to serve as sensors of the chemical or nutritional environment. The lux genes have now been transferred into a variety of different organisms to generate new luminescent species. Naturally dark bacteria containing the luxCDABE and luxAB genes, respectively, are luminescent or emit light on addition of aldehyde. Fusion of the luxAB genes has also allowed the expression of luciferase under a single promoter in eukaryotic systems. The ability to express the lux genes in a variety of prokaryotic and eukaryotic organisms and the ease and sensitivity of the luminescence assay demonstrate the considerable potential of the widespread application of the lux genes as reporters of gene expression and metabolic function. Images PMID:2030669

  5. Optical Chromatography of Bacterial Spores

    NASA Astrophysics Data System (ADS)

    Sundbeck, Steven; Terray, Alex; Arnold, Jonathan; Leski, Tomasz; Hart, Sean

    2007-03-01

    The technique of optical chromatography uses a laser mildly focused against fluid flow in a microfluidic channel to trap microscopic particles. Particles in the channel near the focal point of the laser are drawn toward the beam axis and then accelerated via optical pressure against the fluid flow, reaching an equilibrium point when the optical and fluidic forces on the particle are balanced. This equilibrium point may occur at differing distances from the focal point for microscopic particles with differing properties, such as size, shape, morphology, and refractive index. Thus, identification and separation of particles may be achieved in the system. Optical chromatography may be used as a detection technique for biological particles of interest, either directly or as a means of concentrating and filtering a sample. Of particular interest would be reliable methods for detection of Bacillus anthracis, a common weaponized biological agent. In this work we present optical chromatography experiments on bacterial spores which may be environmentally present with B. anthracis spores and interfere with detection.

  6. Bacterial sorption of heavy metals

    SciTech Connect

    Mullen, M.D.; Wolf, D.C.; Ferris, F.G.; Beveridge, T.J.; Flemming, C.A.

    1989-01-01

    Four bacteria, Bacillus cereus, B. subtilis, Escherichia coli, and Pseudomonas aeruginosa, were examined for the ability to remove Ag{sup +}, Cd{sup 2+}, Cu{sup 2+}, and La{sup 3+} from solution by batch equilibration methods. Cd and Cu sorption over the concentration range 0.001 to 1 mM was described by Freundlich isotherms. At 1 mM concentrations of both Cd{sup 2+} and Cu{sup 2+}, P. aeruginosa and B. cereus were the most and least efficient at metal removal, respectively. Freundlich K constants indicated that E. coli was most efficient at Cd{sup 2+} removal and B. subtilis removed the most Cu{sup 2+}. Removal of Ag{sup +} from solution by bacteria was very efficient; an average of 89% of the total Ag{sup +} was removed from the 1 mM solution, whereas only 12, 29, and 27% of the total Cd{sup 2+}, Cu{sup 2+}, and La{sup 3+}, respectively, were sorbed from 1 mM solutions. Electron microscopy indicated that La{sup 3+} accumulated at the cell surface as needlelike, crystalline precipitates. Silver precipitated as discrete colloidal aggregates at the cell surface and occasionally in the cytoplasma. The results indicate that bacterial cells are capable of binding large quantities of different metals.

  7. BACTERIAL OXIDATION OF DIPICOLINIC ACID

    PubMed Central

    Kobayashi, Yasuo; Arima, Kei

    1962-01-01

    Kobayashi, Yasuo (University of Tokyo, Tokyo, Japan) and Kei Arima. Bacterial oxidation of dipicolinic acid. II. Identification of ?-ketoglutaric acid and 3-hydroxydipicolinic acid and some properties of cell-free extracts. J. Bacteriol. 84:765–771. 1962—When a dipicolinic acid (DPA)-decomposing bacterium, Achromobacter strain 1–2, was incubated at 30 C with shaking in a DPA solution containing 10?3m arsenite, a keto acid was accumulated. The 2,4-dinitrophenylhydrazone of this acid was synthesized and identified as ?-ketoglutaric acid by paper chromatography, visible absorption spectrum, infrared analysis, elemental analysis, and mixed melting point. During this incubation, oxalic acid equivalent to the consumed dipicolinic acid was produced. A fluorescent material was also isolated from culture fluid and identified as 3-hydroxydipicolinic acid by paper chromatography and the ultraviolet absorption spectrum. Further, cell-free extracts were prepared by sonic oscillation. Ferrous ion and a reduced di- or triphosphopyridine nucleotide-generating system were proven to be required for enzymic oxidation of DPA. And 3-hydroxydipicolinic acid was also oxidized by this preparation. From the results obtained, a possible metabolic pathway of dipicolinic acid was proposed. PMID:14033954

  8. Dynamic clustering of bacterial population

    NASA Astrophysics Data System (ADS)

    Ko, Elizabeth P.; Yomo, Tetsuya; Urabe, Itaru

    1994-08-01

    Bacterial cells having the same genotype were observed to split into a few clusters of phenotypes with various levels of enzyme activity. When the mixture of these phenotypically heterogeneous but genotypically homogeneous cells was cultivated in a liquid medium, the distribution of the population size of each cluster of phenotypes showed various kinds of dynamic oscillations. In addition, when this dynamic behavior was examined for the cells of the single colony, various patterns of shifting of homogeneous to heterogeneous lineage and vice versa were observed in the population. The results imply that differentiation of the cells with the same genotype can occur without spatial information and even under the same environment where the cells interact globally without spatial constrait. This interesting phenomenon totally contradicts the conventional biology that the genotype of a cell uniquely determines the phenotype of the cell and its progeny, but is consistent with the theoretical model of cell differentiation presented in the following paper. The sources of discrepancy between the existing theory in molecular biology and our results were discussed and it is concluded that in understanding a complex living system, a simple model consisting of the essence of the complex system can be constructed justifying the observed properties of the molecules in the system which provide free interactions.

  9. Effect of bacterial satellites on Chlamydomonas reinhardtii growth in an algo-bacterial community

    Microsoft Academic Search

    Yu. A. Nikolaev; V. K. Plakunov; N. A. Voronina; N. V. Nemtseva; A. O. Plotnikov; O. A. Gogoleva; M. E. Murav’eva; G. V. Ovechkina

    2008-01-01

    The growth characteristics of an algo-bacterial community (Chlamydomonas reinhardtii and bacterial satellites) were studied, as well as the mechanism and patterns of bacterial effect on algae. Four strains\\u000a of predominant bacteria were isolated and partially characterized. They were assigned to the following taxa: Rhodococcus terrea, Micrococcus roseus, and Bacillus spp. A pure culture of the alga under study was obtained

  10. BACTERIAL INDICATORS OF RECREATIONAL WATER QUALITY

    EPA Science Inventory

    The selection of bacterial indicators of recreational water quality are considered with respect to suggested ideal characteristics, such as association with pathogens, growth in aquatic environments, resistance to disinfection and ease of enumeration, and through the use of epide...

  11. Aquatic microenvironments in bacterial ecology and diversity

    E-print Network

    Hunt, Dana E., Ph. D. Massachusetts Institute of Technology

    2008-01-01

    Molecular surveys have revealed tremendous bacterial diversity in the world's oceans; yet how do these diverse bacteria with the same essential nutrient requirements co-exist in the same environment? This study examines ...

  12. Vaccination against salmonid bacterial kidney disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial kidney disease (BKD) of salmonid fishes, caused by Renibacterium salmoninarum, has presented challenges for development of effective vaccines, despite several decades of research. The only vaccine against BKD that is commercially licensed is an injectable preparation containing live cells ...

  13. Biogenesis of the Gram-Negative Bacterial

    E-print Network

    Mekalanos, John

    Biogenesis of the Gram-Negative Bacterial Outer Membrane Martine P. Bos, Viviane Robert, and Jan lipopolysaccharide, outer membrane proteins, lipoproteins, phospholipids Abstract The cell envelope of gram . . . . . . . . . . . . . . . . . 206 PERSPECTIVES . . . . . . . . . . . . . . . . . . . 206 INTRODUCTION The cell envelope of gram

  14. BACTERIAL IMPACTS OF OCEAN OUTFALLS: LEGAL CHALLENGES

    EPA Science Inventory

    Simple analytical methods are used to help establish wastewater treatment permit conditions. However, a recent lawsuit alleged one such screening method was inadequate to show bacterial water quality standards would be protected shoreward of Honolulu's Honouliuli outfall. In resp...

  15. Diagnosis and treatment of bacterial prostatitis.

    PubMed

    Vide?nik Zorman, Jerneja; Mati?i?, Mojca; Jeverica, Samo; Smrkolj, Tomaž

    2015-06-01

    Prostate inflammation is a common syndrome, especially in men under 50. It usually presents with voiding symptoms and pain in the genitourinary area, and sometimes as sexual dysfunction. Based on clinical and laboratory characteristics, prostatitis is classified as acute bacterial prostatitis, chronic bacterial prostatitis, chronic inflammatory and non-inflammatory prostatitis or chronic pelvic pain syndrome, and asymptomatic inflammatory prostatitis. Bacterial prostatitis is most often caused by infection with uropathogens, mainly Gram-negative bacilli, but Gram-positive and atypical microorganisms have also been identified as causative organisms of chronic prostatitis. According to reports by several authors, Chlamydia trachomatis and Trichomonas vaginalis are some of the most common pathogens, making chronic prostatitis a sexually transmitted disease. Diagnosis and treatment of acute and chronic bacterial prostatitis in particular can be challenging. PMID:26086164

  16. Bacterial contamination of Japanese households and related concern about sanitation

    Microsoft Academic Search

    M. Ojima; Y. Toshima; E. Koya; K. Ara; S. Kawai; N. Ueda

    2002-01-01

    The bacterial contamination of Japanese homes and the attitudes of Japanese people toward sanitation were studied. By taking bacterial counts of approximately 90 places each in five homes, this study found kitchens to have the greatest degree of bacterial contamination, followed by bathing rooms. Toilets had less bacterial contamination than was expected. While concern about bacteria on highly contaminated items

  17. The rise and fall of bacterial clones: Streptococcus pneumoniae

    Microsoft Academic Search

    Christel Blomberg; Jessica Dagerhamn; Patrick Bättig; Staffan Normark; Birgitta Henriques-Normark

    2008-01-01

    Globally spreading bacterial strains belong to clonal types that have the capacity to colonize, spread and cause disease in the community. Recent comparative genomic analyses of well-defined clinical isolates have led to the identification of bacterial properties that are required for the successful spread of bacterial clones. In this Review, we discuss the evolution of bacterial clones, the importance of

  18. Identification and antibiotic susceptibility of bacterial isolates from probiotic products

    Microsoft Academic Search

    R. Temmerman; B. Pot; G. Huys; J. Swings

    2003-01-01

    In the present study, a total of 55 European probiotic products were evaluated with regard to the identity and the antibiotic resistance of the bacterial isolates recovered from these products. Bacterial isolation from 30 dried food supplements and 25 dairy products, yielded a total of 268 bacterial isolates selected from several selective media. Counts of food supplements showed bacterial recovery

  19. Plant innate immunity against human bacterial pathogens

    PubMed Central

    Melotto, Maeli; Panchal, Shweta; Roy, Debanjana

    2014-01-01

    Certain human bacterial pathogens such as the enterohemorrhagic Escherichia coli and Salmonella enterica are not proven to be plant pathogens yet. Nonetheless, under certain conditions they can survive on, penetrate into, and colonize internal plant tissues causing serious food borne disease outbreaks. In this review, we highlight current understanding on the molecular mechanisms of plant responses against human bacterial pathogens and discuss salient common and contrasting themes of plant interactions with phytopathogens or human pathogens. PMID:25157245

  20. Model for the Growth of Bacterial Genomes

    NASA Astrophysics Data System (ADS)

    Hsieh, L. C.; Lee, H. C.

    Analysis of the frequency of occurrence of short oligonucleotides in typical bacterial genomes reveals that they exhibit the statistical characteristics of a DNA sequence of a much shorter length. This peculiar property suggests a model for genome growth in which a genome evolves by random mutation but primarily grows by random segmental self-copying. Computer-generated genome sequence based on this model indeed has statistical properties similar to those of bacterial genomes.

  1. Model for the Growth of Bacterial Genomes

    NASA Astrophysics Data System (ADS)

    Hsieh, L. C.; Lee, H. C.

    2003-04-01

    Analysis of frequency of occurrence of short oligonucleotides in typical bacterial genomes reveals that they exhibit the statistical characteristics of a DNA sequence of a much shorter length. This peculiar property suggests a model for genome growth in which a genome evolves by random mutation but primarily grows by random segmental selfcopying. Computer generated genome sequence based on the model indeed have statistical properties similar to those of bacterial genomes.

  2. A Mathematical Model for Bacterial Chemotaxis

    PubMed Central

    Lapidus, I. Richard; Schiller, Ralph

    1974-01-01

    A differential equation describing the chemotactic migration of a bacterial population in a fixed exponential gradient of attractant has been integrated using the appropriate boundary conditions. The solution predicts an initial bacterial accumulation at the concentration “knee” with the final distribution of bacteria approaching a time-independent state. Specific additional experiments to obtain further data for a rigorous test of the theory are suggested. PMID:4433673

  3. Ultraviolet Radiation Alters Maize Phyllosphere Bacterial Diversity

    Microsoft Academic Search

    H. Kadivar; A. E. Stapleton

    2003-01-01

    Epiphytic bacteria are subjected to very stressful environments, including UV radiation. Bacterial assemblages on Zea mays (maize) leaves exposure were examined with and without UV-B radiation. Culture-independent molecular techniques were utilized for bacterial identification, diversity analysis and selection of putative UV exposure marker sequences. Few sequences corresponded to previously characterized phyllosphere bacteria. There was a strong tendency toward increased 16S

  4. The bacterial biogeography of British soils.

    PubMed

    Griffiths, Robert I; Thomson, Bruce C; James, Phillip; Bell, Thomas; Bailey, Mark; Whiteley, Andrew S

    2011-06-01

    Despite recognition of the importance of soil bacteria to terrestrial ecosystem functioning there is little consensus on the factors regulating belowground biodiversity. Here we present a multi-scale spatial assessment of soil bacterial community profiles across Great Britain (> 1000 soil cores), and show the first landscape scale map of bacterial distributions across a nation. Bacterial diversity and community dissimilarities, assessed using terminal restriction fragment length polymorphism, were most strongly related to soil pH providing a large-scale confirmation of the role of pH in structuring bacterial taxa. However, while ? diversity was positively related to pH, the converse was true for ? diversity (between sample variance in ? diversity). ? diversity was found to be greatest in acidic soils, corresponding with greater environmental heterogeneity. Analyses of clone libraries revealed the pH effects were predominantly manifest at the level of broad bacterial taxonomic groups, with acidic soils being dominated by few taxa (notably the group 1 Acidobacteria and Alphaproteobacteria). We also noted significant correlations between bacterial communities and most other measured environmental variables (soil chemistry, aboveground features and climatic variables), together with significant spatial correlations at close distances. In particular, bacterial and plant communities were closely related signifying no strong evidence that soil bacteria are driven by different ecological processes to those governing higher organisms. We conclude that broad scale surveys are useful in identifying distinct soil biomes comprising reproducible communities of dominant taxa. Together these results provide a baseline ecological framework with which to pursue future research on both soil microbial function, and more explicit biome based assessments of the local ecological drivers of bacterial biodiversity. PMID:21507180

  5. Bacterial mechanosensitive channels: Experiment and theory

    Microsoft Academic Search

    Ben Corry; Boris Martinac

    2008-01-01

    Since their discovery in Escherichia coli some 20 years ago, studies of bacterial mechanosensitive (MS) ion channels have been at the forefront of the MS channel research field. Two major events greatly advanced the research on bacterial MS channels: (i) cloning of MscL and MscS, the MS channels of Large and Small conductance, and (ii) solving their 3D crystal structure. These

  6. Horizontal gene transfer and bacterial diversity

    Microsoft Academic Search

    Chitra Dutta; Archana Pan

    2002-01-01

    Bacterial genomes are extremely dynamic and mosaic in nature. A substantial amount of genetic information is inserted into\\u000a or deleted from such genomes through the process of horizontal transfer. Through the introduction of novel physiological traits\\u000a from distantly related organisms, horizontal gene transfer often causes drastic changes in the ecological and pathogenic character\\u000a of bacterial species and thereby promotes microbial

  7. Evaluation of small bowel bacterial overgrowth

    Microsoft Academic Search

    Lawrence R. Schiller

    2007-01-01

    Small bowel bacterial overgrowth historically has been associated with malabsorption syndrome attributed to deconjugation\\u000a of bile acids in the upper small intestine. Recent reports raise the possibility that bacterial overgrowth may be a cause\\u000a of watery diarrhea or irritable bowel syndrome. Quantitative culture of jejunal contents has been the gold standard for diagnosis,\\u000a but a variety of indirect tests have

  8. Pathophysiology and Treatment of Bacterial Meningitis

    PubMed Central

    Hoffman, Olaf

    2009-01-01

    Bacterial meningitis is a medical emergency requiring immediate diagnosis and immediate treatment. Streptococcus pneumoniae and Neisseria meningitidis are the most common and most aggressive pathogens of meningitis. Emerging antibiotic resistance is an upcoming challenge. Clinical and experimental studies have established a more detailed understanding of the mechanisms resulting in brain damage, sequelae and neuropsychological deficits. We summarize the current pathophysiological concept of acute bacterial meningitis and present current treatment strategies. PMID:21180625

  9. Bacterial adhesion on PEG modified polyurethane surfaces

    Microsoft Academic Search

    Ki Dong Park; Young Soo Kim; Dong Keun Han; Young Ha Kim; Eun Hee Bae Lee; Hwal Suh; Kyu Suk Choi

    1998-01-01

    Polyurethane surface was modified with poly(ethylene glycol) (mol. wt. 1000, PEG1k) carrying terminal hydroxyl, amino and sulfonate groups, poly(ethylene glucol) (mol. wt. 3350, PEG3.4k) and PEG3.4k-Heparin, respectively. These surfaces were investigatted for bacterial adhesion using S. epidermidis and E. coli in tryptic soya broth (TSB), brain heart infusion (BHI), and human plasma. All PEG modified surfaces reduced bacterial adhesion significantly

  10. Formation and Dissolution of Bacterial Colonies

    E-print Network

    Christoph Weber; Yen Ting Lin; Nicolas Biais; Vasily Zaburdaev

    2015-06-03

    Many organisms form colonies for a transient period of time to withstand environmental pressure. Bacterial biofilms are a prototypical example of such behavior. Despite significant interest across disciplines, physical mechanisms governing the formation and dissolution of bacterial colonies are still poorly understood. Starting from a kinetic description of motile and interacting cells we derive a hydrodynamic equation for their density on a surface. We use it to describe formation of multiple colonies with sizes consistent with experimental data and to discuss their dissolution.

  11. Asteroid family ages

    E-print Network

    Spoto, Federica; Knezevic, Zoran

    2015-01-01

    A new family classification, based on a catalog of proper elements with $\\sim 384,000$ 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 pro...

  12. Comprehensive phylogenetic analysis of bacterial reverse transcriptases.

    PubMed

    Toro, Nicolás; Nisa-Martínez, Rafael

    2014-01-01

    Much less is known about reverse transcriptases (RTs) in prokaryotes than in eukaryotes, with most prokaryotic enzymes still uncharacterized. Two surveys involving BLAST searches for RT genes in prokaryotic genomes revealed the presence of large numbers of diverse, uncharacterized RTs and RT-like sequences. Here, using consistent annotation across all sequenced bacterial species from GenBank and other sources via RAST, available from the PATRIC (Pathogenic Resource Integration Center) platform, we have compiled the data for currently annotated reverse transcriptases from completely sequenced bacterial genomes. RT sequences are broadly distributed across bacterial phyla, but green sulfur bacteria and cyanobacteria have the highest levels of RT sequence diversity (?85% identity) per genome. By contrast, phylum Actinobacteria, for which a large number of genomes have been sequenced, was found to have a low RT sequence diversity. Phylogenetic analyses revealed that bacterial RTs could be classified into 17 main groups: group II introns, retrons/retron-like RTs, diversity-generating retroelements (DGRs), Abi-like RTs, CRISPR-Cas-associated RTs, group II-like RTs (G2L), and 11 other groups of RTs of unknown function. Proteobacteria had the highest potential functional diversity, as they possessed most of the RT groups. Group II introns and DGRs were the most widely distributed RTs in bacterial phyla. Our results provide insights into bacterial RT phylogeny and the basis for an update of annotation systems based on sequence/domain homology. PMID:25423096

  13. Irrigant divalent cation concentrations influence bacterial adhesion

    PubMed Central

    Dass, Clarissa L.; Walsh, Mary F.; Seo, Sue; Shiratsuchi, Hiroe; Craig, David H.; Basson, Marc D.

    2009-01-01

    Background Surgical wounds are frequently contaminated by microbes, but rarely become infected if the bacterial burden is low, and irrigation is used to reduce contamination. Wound fluids are low in calcium and high in magnesium. We hypothesized that manipulating irrigant divalent cation concentrations might influence bacterial adhesion. Methods Staphylococcus aureus, E. coli, and Pseudomonas aeruginosa were stained with fluorescent Calcein AM before plating onto fibroblast monolayers, collagen I, or uncoated bacteriologic plastic. After one hour, wells were washed with HEPES-buffered pH-balanced sterile water without or with 5mM CaCl2, 5mM MgCl2 or 1mM EDTA+EGTA, and the remaining adherent bacteria were assayed fluorometrically. Results Supplementing the irrigation with magnesium or chelators increased but calcium-supplemented irrigation reduced bacterial adhesion to collagen or fibroblasts. Non-specific electrostatic bacterial adhesion to uncoated plastic was unaffected by calcium. Conclusion Bacterial adhesion to mammalian cells and matrix proteins is influenced by divalent cations, and pathogenic bacteria may be adapted to adhere under the low calcium high magnesium conditions in wounds. Although these results await confirmation for other bacteria, and in vivo validation and safety-testing, they suggest that supplementing wound irrigation with 5mM CaCl2 may reduce bacterial adhesion and subsequent wound infection. PMID:19577252

  14. Novel Strategies to Combat Bacterial Virulence

    PubMed Central

    Lynch, S.V.; Wiener-Kronish, J.P.

    2010-01-01

    Purpose of review Incidences of antimicrobial resistant infections have increased dramatically over the past several decades and are associated with adverse patient outcomes. Alternative approaches to combat infection are critical, and have led to the development of more specific drugs targeted at particular bacterial virulence systems or essential regulatory pathways. The purpose of this review is to highlight the recent developments in anti-bacterial therapy and the novel approaches toward increasing our therapeutic armory against bacterial infection. Recent findings Although classic antibiotic development is not occurring rapidly, alternative therapeutics that target specific bacterial virulence systems are progressing from the discovery stage through the FDA approval process. Here we review novel antibodies that target specific virulence systems as well as a variety of newly discovered small molecules that block bacterial attachment, communication systems (quorum sensing) or important regulatory processes associated with virulence gene expression. Summary The success of novel therapeutics could significantly change clinical practice. Furthermore, the complications of collateral damage due to antibiotic administration e.g. suprainfections or decreased host immunity due to loss of synergistic bacterial communities, may be minimized using therapeutics that specifically target pathogenic behavior. PMID:18787455

  15. The importance of the family system in family business

    Microsoft Academic Search

    Ramona K. Zachary

    2011-01-01

    Purpose – Most researchers overlook the family system in the pursuit of family business studies and research. They mistakenly have assumed that the study of only the family business is sufficient to understand the influence and effect of the family itself. The importance the family system is documented as well as the evolution of family business as a field of

  16. FA (Fanconi Anemia) Family Newsletter

    MedlinePLUS

    ... our mailing list form . View our current newsletter: Spring 2015 - Family Newsletter #57 Past newsletters: Fall 2014 - Family Newsletter #56 Spring 2014 - Family Newsletter #55 Fall 2013 - Family Newsletter # ...

  17. Family Literacy Schools, teachers and

    E-print Network

    Ellis, Randy

    1 Family Literacy Schools, teachers and family literacy . . . . . . . . . . . . . . 4 A snapshot of National Family Literacy . . . . . . . . . . . . . 6 A representative community organization . . . 7 Supporting regional cooperation . . . . . . . . . . . . . . . 8 Family Literacy: Programming that Works

  18. Electron Cryotomography of Bacterial Cells

    PubMed Central

    Chen, Songye; McDowall, Alasdair; Dobro, Megan J.; Briegel, Ariane; Ladinsky, Mark; Shi, Jian; Tocheva, Elitza I.; Beeby, Morgan; Pilhofer, Martin; Ding, H. Jane; Li, Zhuo; Gan, Lu; Morris, Dylan M.; Jensen, Grant J.

    2010-01-01

    While much is already known about the basic metabolism of bacterial cells, many fundamental questions are still surprisingly unanswered, including for instance how they generate and maintain specific cell shapes, establish polarity, segregate their genomes, and divide. In order to understand these phenomena, imaging technologies are needed that bridge the resolution gap between fluorescence light microscopy and higher-resolution methods such as X-ray crystallography and NMR spectroscopy. Electron cryotomography (ECT) is an emerging technology that does just this, allowing the ultrastructure of cells to be visualized in a near-native state, in three dimensions (3D), with "macromolecular" resolution (~4nm).1, 2 In ECT, cells are imaged in a vitreous, "frozen-hydrated" state in a cryo transmission electron microscope (cryoTEM) at low temperature (< -180°C). For slender cells (up to ~500 nm in thickness3), intact cells are plunge-frozen within media across EM grids in cryogens such as ethane or ethane/propane mixtures. Thicker cells and biofilms can also be imaged in a vitreous state by first "high-pressure freezing" and then, "cryo-sectioning" them. A series of two-dimensional projection images are then collected through the sample as it is incrementally tilted along one or two axes. A three-dimensional reconstruction, or "tomogram" can then be calculated from the images. While ECT requires expensive instrumentation, in recent years, it has been used in a few labs to reveal the structures of various external appendages, the structures of different cell envelopes, the positions and structures of cytoskeletal filaments, and the locations and architectures of large macromolecular assemblies such as flagellar motors, internal compartments and chemoreceptor arrays.1, 2 In this video article we illustrate how to image cells with ECT, including the processes of sample preparation, data collection, tomogram reconstruction, and interpretation of the results through segmentation and in some cases correlation with light microscopy. PMID:20461053

  19. Molecular analysis of bacterial cytolysins.

    PubMed

    Chakraborty, T; Kathariou, S; Hacker, J; Hof, H; Huhle, B; Wagner, W; Kuhn, M; Goebel, W

    1987-01-01

    Results of molecular and pathogenic studies of three different bacterial hemolysins (cytolysins) are presented. These exoproteins derive from the two gram-negative bacteria Escherichia coli and Aeromonas hydrophila and from the gram-positive pathogen Listeria monocytogenes. The hemolysin of E. coli is determined by an 8-kilobase (kb) region that includes four clustered genes (hlyC, hlyA, hlyB, and hlyD). This hemolysin determinant is part either of large transmissible plasmids or of the chromosome. The genes located chromosomally are found predominantly in E. coli strains that can cause pyelonephritis and/or other extraintestinal infections. A detailed analysis of the chromosomal hyl determinants of one nephropathogenic E. coli strain revealed the existence of specific, large chromosomal insertions 75 kb and 100 kb in size that carry the hly genes but that also influence the expression of other virulence properties, i.e., adhesion and serum resistance. The direct involvement of E. coli hemolysin in virulence could be demonstrated in several model systems. The genetic determinants for hemolysin (cytolysin) formation in A. hydrophila (aerolysin) and L. monocytogenes (listeriolysin) are less complex. Both cytolysins seem to be encoded by single genes, although two loci (aerB and aerC) that affect the expression and activity of aerolysin have been identified distal and proximal to the structural gene for aerolysin (aerA). Cytolysin-negative mutants of both bacteria were obtained by site-specific deletion and/or transposon mutagenesis. These mutants show a drastic reduction in the virulence of the respective bacteria. PMID:2825323

  20. FAMILIES FIRST: Keys to Successful Family Functioning Family Roles

    E-print Network

    Liskiewicz, Maciej

    develop- ment of children and adults. Examples of this role are a parent helping a child make it through, par- ents are expected to teach, discipline, and provide for their children. And children are expected to cooperate and respect their parents. As family members age, they take on additional roles, such as becoming

  1. Conserved structure and domain organization among bacterial Slc26 transporters.

    PubMed

    Compton, Emma L R; Page, Kimberly; Findlay, Heather E; Haertlein, Michael; Moulin, Martine; Zachariae, Ulrich; Norman, David G; Gabel, Frank; Javelle, Arnaud

    2014-10-15

    The Slc26 proteins are a ubiquitous superfamily of anion transporters conserved from bacteria to humans, among which four have been identified as human disease genes. Our functional knowledge of this protein family has increased but limited structural information is available. These proteins contain a transmembrane (TM) domain and a C-terminal cytoplasmic sulfate transporter and anti-sigma factor (STAS) domain. In a fundamental step towards understanding the structure/function relationships within the family we have used small-angle neutron scattering (SANS) on two distantly related bacterial homologues to show that there is a common, dimeric and structural architecture among Slc26A transporters. Pulsed electron-electron double resonance (PELDOR) spectroscopy supports the dimeric SANS-derived model. Using chimaeric/truncated proteins we have determined the domain organization: the STAS domains project away from the TM core and are essential for protein stability. We use the SANS-generated envelopes to assess a homology model of the TM core. PMID:25031084

  2. Innate antimicrobial peptide protects the skin from invasive bacterial infection.

    PubMed

    Nizet, V; Ohtake, T; Lauth, X; Trowbridge, J; Rudisill, J; Dorschner, R A; Pestonjamasp, V; Piraino, J; Huttner, K; Gallo, R L

    2001-11-22

    In mammals, several gene families encode peptides with antibacterial activity, such as the beta-defensins and cathelicidins. These peptides are expressed on epithelial surfaces and in neutrophils, and have been proposed to provide a first line of defence against infection by acting as 'natural antibiotics'. The protective effect of antimicrobial peptides is brought into question by observations that several of these peptides are easily inactivated and have diverse cellular effects that are distinct from antimicrobial activity demonstrated in vitro. To investigate the function of a specific antimicrobial peptide in a mouse model of cutaneous infection, we applied a combined mammalian and bacterial genetic approach to the cathelicidin antimicrobial gene family. The mature human (LL-37) and mouse (CRAMP) peptides are encoded by similar genes (CAMP and Cnlp, respectively), and have similar alpha-helical structures, spectra of antimicrobial activity and tissue distribution. Here we show that cathelicidins are an important native component of innate host defence in mice and provide protection against necrotic skin infection caused by Group A Streptococcus (GAS). PMID:11719807

  3. The Growth of a Family

    PubMed Central

    Carroll, June C.; Biringer, Anne

    1991-01-01

    Caring for a family during pregnancy and birth is an ideal opportunity for family physicians to assess family functioning and help the family adjust to the birth of a new child. Stress and support systems can influence the course of pregnancy, including obstetric and perinatal outcomes. A family-centered approach can help patients during this critical stage of family development. PMID:21229107

  4. Family dynamics and family psychotherapy of psychosomatic.

    PubMed

    Wirsching, M; Stierlin, H

    1979-01-01

    Family therapy of psychosomatic disorders is oftern difficult and comparable to the therapy of psychotic patients. Nonetheless, the results published today by authors such as Minuchin and Selvini and our own experiences are promising indeed. We have found that what seemed to be a deep-rooted psychic structure changed rapidly and enduringly if the relationship field changed. Amelioration of symptoms is in many cases easily attained if they are understood in their function within a relational system. Also, we regard the system or family approach as a chance for medical practice. The general practioner who usually deals with family systems has, in our view, an ideal position to bring about change if he uses his authority and trust properly. He has to obtain a positive, not pathology-oriented view and should use family and social resources in spite of engaging in an often fruitless and endless contact with the designated patient, which only serves to maintain and even to increase the homeostatic lock of the family system. PMID:550166

  5. Bacterial sedimentation through a porous medium

    SciTech Connect

    Wan, Jiamin; Tokunaga, T.K.; Tsang, Chin-Fu [Lawrence Berkeley Lab., CA (United States)] [Lawrence Berkeley Lab., CA (United States)

    1995-07-01

    Numerous previous studies of bacterial transport in groundwaters and to deep aquifers and sediments have either neglected, or regarded as insignificant, the potential contribution of bacterial sedimentation. This study examines the potential significance of sedimentation as a mechanism for bacterial transport. A simple model is developed to predict the behavior of particles (bacterial or inorganic colloids) sedimenting through granular porous media under hydrostatic conditions. The model indicates that tortuosity-limited sedimentation velocities through porous media consisting of large, well-rounded grains can proceed at velocities close to ({approximately} 90% that of) free sedimentation in water columns when particle-grain interactions involve only tortuosity. The assumption of neutral buoyancy of bacteria was demonstrated to be invalid through buoyant density measurements on 25 subsurface bacterial strains (using Percoll density gradient centrifugation). An average buoyant density of 1.088 Mg m{sup {minus}3}. The two nonmotile bacterial strains selected for sedimentation experiments were Arthrobacter globiformis B672 (isolated from the Middendorf aquifer, 259-m depth), and OYS3, a streptomycin-resistant strain isolated from shallow groundwaters at Oyster, Virginia. All experiments were carried out under nongrowth conditions. Stokes` law sedimentation velocities for the two bacterial strains calculated from measurements of buoyant densities and characteristic sizes were 5.8 and 40 mm d{sup {minus}1} respectively. Direct measurements of free sedimentation of Arthrobacter B672 and OYS3 through water columns (21{degrees}C) yielded median velocities of 7.1 and 42 mm d{sup {minus}1} respectively, in good agreement with Stokes law calculations. The Arthrobacter B672 and OYS3 strains sedimented through saturated sand columns (quartz sand, 300-420 {mu}m diameter) under hydrostatic conditions at median velocities of 7.1 and 42 mm d{sup {minus}1}. 44 refs., 8 figs., 2 tabs.

  6. Biomechanics of Bacterial Walls: Studies of Bacterial Thread Made from Bacillus subtilis

    Microsoft Academic Search

    J. J. Thwaites; Neil H. Mendelson

    1985-01-01

    Bacterial threads of up to 1 m in length have been produced from filaments of separation-suppressed mutants of Bacillus subtilis. Individual threads may contain 20,000 cellular filaments in parallel alignment. The tensile properties of bacterial threads have been examined by using conventional textile engineering techniques. The kinetics of elongation at constant load are indicative of a viscoelastic material. Both Young's

  7. [Family planning in Brazil].

    PubMed

    Nakamura, M S; Fonseca, J P; Aguinaga, H; Busch, C J; Marlet, J M

    1978-02-01

    In 1970, 41.6% of the Brazilian population was represented by children aged 0-14, and by 21.3% of women in fertile age; the birth rate was 36.9/1000. Without an appropriate national program of family planning, Brazil will have in the year 2000, 218.8 million inhabitants. The need for family planning services in Brazil is evident, even more so since abortion is forbidden, unless for therapeutic reasons. A national family planning program should include a complete range of maternal and child services, and screening for high-risk women; in other words, family planning should be thought of and used as preventive medicine. Family planning is not so much a right as a duty of the couple. The Catholic church, largely prevalent in Brazil, approves of family planning when practiced with the means allowed by the church itself. PMID:12311569

  8. Sensing of Interleukin-1 Cytokines during Streptococcus pneumoniae Colonization Contributes to Macrophage Recruitment and Bacterial Clearance.

    PubMed

    Lemon, Jamie K; Miller, Megan R; Weiser, Jeffrey N

    2015-08-01

    Streptococcus pneumoniae (the pneumococcus), a leading cause of bacterial disease, is most commonly carried in the human nasopharynx. Colonization induces inflammation that promotes the organism's growth and transmission. This inflammatory response is dependent on intracellular sensing of bacterial components that access the cytosolic compartment via the pneumococcal pore-forming toxin pneumolysin. In vitro, cytosolic access results in cell death that includes release of the proinflammatory cytokine interleukin-1? (IL-1?). IL-1 family cytokines, including IL-1?, are secreted upon activation of inflammasomes, although the role of this activation in the host immune response to pneumococcal carriage is unknown. Using a murine model of pneumococcal nasopharyngeal colonization, we show that mice deficient in the interleukin-1 receptor type 1 (Il1r1(-/-)) have reduced numbers of neutrophils early after infection, fewer macrophages later in carriage, and prolonged bacterial colonization. Moreover, intranasal administration of Il-1? promoted clearance. Macrophages are the effectors of clearance, and characterization of macrophage chemokines in colonized mice revealed that Il1r1(-/-) mice have lower expression of the C-C motif chemokine ligand 6 (CCL6), correlating with reduced macrophage recruitment to the nasopharynx. IL-1 family cytokines are known to promote adaptive immunity; however, we observed no difference in the development of humoral or cellular immunity to pneumococcal colonization between wild-type and Il1r1(-/-) mice. Our findings show that sensing of IL-1 cytokines during colonization promotes inflammation without immunity, which may ultimately benefit the pneumococcus. PMID:26034210

  9. Insect peptides with improved protease-resistance protect mice against bacterial infection.

    PubMed Central

    Otvos, L.; Bokonyi, K.; Varga, I.; Otvos, B. I.; Hoffmann, R.; Ertl, H. C.; Wade, J. D.; McManus, A. M.; Craik, D. J.; Bulet, P.

    2000-01-01

    At a time of the emergence of drug-resistant bacterial strains, the development of antimicrobial compounds with novel mechanisms of action is of considerable interest. Perhaps the most promising among these is a family of antibacterial peptides originally isolated from insects. These were shown to act in a stereospecific manner on an as-yet unidentified target bacterial protein. One of these peptides, drosocin, is inactive in vivo due to the rapid decomposition in mammalian sera. However, another family member, pyrrhocoricin, is significantly more stable, has increased in vitro efficacy against gram-negative bacterial strains, and if administered alone, as we show here, is devoid of in vitro or in vivo toxicity. At low doses, pyrrhocoricin protected mice against Escherichia coli infection, but at a higher dose augmented the infection of compromised animals. Analogs of pyrrhocoricin were, therefore, synthesized to further improve protease resistance and reduce toxicity. A linear derivative containing unnatural amino acids at both termini showed high potency and lack of toxicity in vivo and an expanded cyclic analog displayed broad activity spectrum in vitro. The bioactive conformation of native pyrrhocoricin was determined by nuclear magnetic resonance spectroscopy, and similar to drosocin, reverse turns were identified as pharmacologically important elements at the termini, bridged by an extended peptide domain. Knowledge of the primary and secondary structural requirements for in vivo activity of these peptides allows the design of novel antibacterial drug leads. PMID:10794416

  10. Cultivable bacterial microbiota of northern bobwhite (Colinus virginianus): a new reservoir of antimicrobial resistance?

    PubMed

    Su, Hongwen; McKelvey, Jessica; Rollins, Dale; Zhang, Michael; Brightsmith, Donald J; Derr, James; Zhang, Shuping

    2014-01-01

    The northern bobwhite (Colinus virginianus) is an ecologically and economically important avian species. At the present time, little is known about the microbial communities associated with these birds. As the first step to create a quail microbiology knowledge base, the current study conducted an inventory of cultivable quail tracheal, crop, cecal, and cloacal microbiota and associated antimicrobial resistance using a combined bacteriology and DNA sequencing approach. A total of 414 morphologically unique bacterial colonies were selected from nonselective aerobic and anaerobic cultures, as well as selective and enrichment cultures. Analysis of the first 500-bp 16S rRNA gene sequences in conjunction with biochemical identifications revealed 190 non-redundant species-level taxonomic units, representing 160 known bacterial species and 30 novel species. The bacterial species were classified into 4 phyla, 14 orders, 37 families, and 59 or more genera. Firmicutes was the most commonly encountered phylum (57%) followed by Actinobacteria (24%), Proteobacteria (17%) and Bacteroidetes (0.02%). Extensive diversity in the species composition of quail microbiota was observed among individual birds and anatomical locations. Quail microbiota harbored several opportunistic pathogens, such as E. coli and Ps. aeruginosa, as well as human commensal organisms, including Neisseria species. Phenotypic characterization of selected bacterial species demonstrated a high prevalence of resistance to the following classes of antimicrobials: phenicol, macrolide, lincosamide, quinolone, and sulphate. Data from the current investigation warrant further investigation on the source, transmission, pathology, and control of antimicrobial resistance in wild quail populations. PMID:24937705

  11. Cultivable Bacterial Microbiota of Northern Bobwhite (Colinus virginianus): A New Reservoir of Antimicrobial Resistance?

    PubMed Central

    Su, Hongwen; McKelvey, Jessica; Rollins, Dale; Zhang, Michael; Brightsmith, Donald J.; Derr, James; Zhang, Shuping

    2014-01-01

    The northern bobwhite (Colinus virginianus) is an ecologically and economically important avian species. At the present time, little is known about the microbial communities associated with these birds. As the first step to create a quail microbiology knowledge base, the current study conducted an inventory of cultivable quail tracheal, crop, cecal, and cloacal microbiota and associated antimicrobial resistance using a combined bacteriology and DNA sequencing approach. A total of 414 morphologically unique bacterial colonies were selected from nonselective aerobic and anaerobic cultures, as well as selective and enrichment cultures. Analysis of the first 500-bp 16S rRNA gene sequences in conjunction with biochemical identifications revealed 190 non-redundant species-level taxonomic units, representing 160 known bacterial species and 30 novel species. The bacterial species were classified into 4 phyla, 14 orders, 37 families, and 59 or more genera. Firmicutes was the most commonly encountered phylum (57%) followed by Actinobacteria (24%), Proteobacteria (17%) and Bacteroidetes (0.02%). Extensive diversity in the species composition of quail microbiota was observed among individual birds and anatomical locations. Quail microbiota harbored several opportunistic pathogens, such as E. coli and Ps. aeruginosa, as well as human commensal organisms, including Neisseria species. Phenotypic characterization of selected bacterial species demonstrated a high prevalence of resistance to the following classes of antimicrobials: phenicol, macrolide, lincosamide, quinolone, and sulphate. Data from the current investigation warrant further investigation on the source, transmission, pathology, and control of antimicrobial resistance in wild quail populations. PMID:24937705

  12. A tale of two chitons: is habitat specialisation linked to distinct associated bacterial communities?

    PubMed

    Duperron, Sébastien; Pottier, Marie-Anne; Léger, Nelly; Gaudron, Sylvie M; Puillandre, Nicolas; Le Prieur, Stéphanie; Sigwart, Julia D; Ravaux, Juliette; Zbinden, Magali

    2013-03-01

    Although most chitons (Mollusca: Polyplacophora) are shallow-water molluscs, diverse species also occur in deep-sea habitats. We investigated the feeding strategies of two species, Leptochiton boucheti and Nierstraszella lineata, recovered on sunken wood sampled in the western Pacific, close to the Vanuatu Islands. The two species display distinctly different associations with bacterial partners. Leptochiton boucheti harbours Mollicutes in regions of its gut epithelium and has no abundant bacterium associated with its gill. Nierstraszella lineata displays no dense gut-associated bacteria, but harbours bacterial filaments attached to its gill epithelium, related to the Deltaproteobacteria symbionts found in gills of the wood-eating limpet Pectinodonta sp. Stable carbon and nitrogen isotope signatures and an absence of cellulolytic activity give evidence against a direct wood-feeding diet; both species are secondary consumers within the wood food web. We suggest that the distinct associations with bacterial partners are linked to niche specialisations of the two species. Nierstraszella lineata is in a taxonomic family restricted to sunken wood and is possibly adapted to more anoxic conditions thanks to its gill-associated bacteria. Leptochiton boucheti is phylogenetically more proximate to an ancestral form not specialised on wood and may itself be more of a generalist; this observation is congruent with its association with Mollicutes, a bacterial clade comprising gut-associated bacteria occurring in several metazoan phyla. PMID:22988940

  13. Coral transcriptome and bacterial community profiles reveal distinct Yellow Band Disease states in Orbicella faveolata.

    PubMed

    Closek, Collin J; Sunagawa, Shinichi; DeSalvo, Michael K; Piceno, Yvette M; DeSantis, Todd Z; Brodie, Eoin L; Weber, Michele X; Voolstra, Christian R; Andersen, Gary L; Medina, Mónica

    2014-12-01

    Coral diseases impact reefs globally. Although we continue to describe diseases, little is known about the etiology or progression of even the most common cases. To examine a spectrum of coral health and determine factors of disease progression we examined Orbicella faveolata exhibiting signs of Yellow Band Disease (YBD), a widespread condition in the Caribbean. We used a novel combined approach to assess three members of the coral holobiont: the coral-host, associated Symbiodinium algae, and bacteria. We profiled three conditions: (1) healthy-appearing colonies (HH), (2) healthy-appearing tissue on diseased colonies (HD), and (3) diseased lesion (DD). Restriction fragment length polymorphism analysis revealed health state-specific diversity in Symbiodinium clade associations. 16S ribosomal RNA gene microarrays (PhyloChips) and O. faveolata complimentary DNA microarrays revealed the bacterial community structure and host transcriptional response, respectively. A distinct bacterial community structure marked each health state. Diseased samples were associated with two to three times more bacterial diversity. HD samples had the highest bacterial richness, which included components associated with HH and DD, as well as additional unique families. The host transcriptome under YBD revealed a reduced cellular expression of defense- and metabolism-related processes, while the neighboring HD condition exhibited an intermediate expression profile. Although HD tissue appeared visibly healthy, the microbial communities and gene expression profiles were distinct. HD should be regarded as an additional (intermediate) state of disease, which is important for understanding the progression of YBD. PMID:24950107

  14. 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

  15. The family and schizophrenia.

    PubMed

    Reiss, D

    1976-02-01

    The author discusses the role of the family in the etiology of schizophrenia and suggests how this research might be integrated with our growing knowledge of the biology of schizophrenia. Abnormalities of family interaction-particularly communication deviances-are frequently associated with schizophrenia and may play a causal, rather than epiphenomenal, role in its pathogenesis. Communication processes in family life affect the child's development of attentional and perceptual capacities, which also have strong biologic roots. The author suggests that the study of normal and abnormal perceptual development might be a meeting ground for researchers in the areas of the biological and familial theories of schizophrenia. PMID:1082721

  16. 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…

  17. Marine Mesocosm Bacterial Colonisation of Volcanic Ash

    NASA Astrophysics Data System (ADS)

    Witt, V.; Cimarelli, C.; Ayris, P. M.; Kueppers, U.; Erpenbeck, D.; Dingwell, D. B.; Woerheide, G.

    2014-12-01

    Explosive 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 or regional scales. Shallow-water coral reef ecosystems - "rainforests of the sea" - are highly sensitive to disturbances, such as ocean acidification, sedimentation and eutrophication. Therefore, ash deposition 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, it is currently unknown which bacteria are involved in pioneer colonisation. We hypothesize that physico-chemical properties (i.e., morphology, chemistry, mineralogy) of the ash may dictate bacterial colonisation. We have tested the effect of substrate properties on bacterial diversity and abundance colonising five substrates: i) quartz sand ii) crystalline ash from the Sakurajima volcano (Japan) iii) volcanic glass iv) carbonate reef sand and v) calcite sand of similar grain size - by incubation in a controlled marine mesocosm (coral reef aquarium) under low light conditions for three 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 supports 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 and carried 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.

  18. Final Report - Ferrographic Tracking of Bacterial Transport

    SciTech Connect

    William P. Johnson

    2002-10-10

    The work performed during the past three years has been extremely productive. Ferrographic capture was utilized in analysis of several thousand field samples collected from arrays of multilevel samplers during three intensive field campaigns conducted at two shallow sandy aquifer sites in Oyster, VA. This work has shown resulted in three important conclusions: (1) Ferrographic capture provides unparalleled low quantitation limits for bacterial cell enumeration (Johnson et al., 2000). (2) The high-resolution analyses provided by ferrographic capture allowed observation of increased bacterial removal rates (from groundwater) that corresponded to increased populations of protozoa in the groundwater (Zhang et al., 2001). This novel data allowed determination of bacterial predation rates by protists in the field, a consideration that will be important for successful bioaugmentation strategies. (3) The high-resolution analyses provided by ferrographic capture allowed observation of detachment of indigenous cells in response to breakthrough of injected cells in groundwater (Johnson et al., 2001). The implication of this unique observation is that bacterial transport, specifically bacterial attachment and detachment, may be much more dynamic than has been indicated by short-term laboratory and field studies. Dynamic attachment and detachment of bacteria in groundwater may lead to greatly increased transport distances over long terms relative to what has been indicated by short-term laboratory and field studies.

  19. The Staphylococci Phages Family: An Overview

    PubMed Central

    Deghorain, Marie; Van Melderen, Laurence

    2012-01-01

    Due to their crucial role in pathogenesis and virulence, phages of Staphylococcus aureus have been extensively studied. Most of them encode and disseminate potent staphylococcal virulence factors. In addition, their movements contribute to the extraordinary versatility and adaptability of this prominent pathogen by improving genome plasticity. In addition to S. aureus, phages from coagulase-negative Staphylococci (CoNS) are gaining increasing interest. Some of these species, such as S. epidermidis, cause nosocomial infections and are therefore problematic for public health. This review provides an overview of the staphylococcal phages family extended to CoNS phages. At the morphological level, all these phages characterized so far belong to the Caudovirales order and are mainly temperate Siphoviridae. At the molecular level, comparative genomics revealed an extensive mosaicism, with genes organized into functional modules that are frequently exchanged between phages. Evolutionary relationships within this family, as well as with other families, have been highlighted. All these aspects are of crucial importance for our understanding of evolution and emergence of pathogens among bacterial species such as Staphylococci. PMID:23342361

  20. Bacterial pyrogenic exotoxins as superantigens.

    PubMed Central

    Kotb, M

    1995-01-01

    The recent discovery of the mode of interaction between a group of microbial proteins known as superantigens and the immune system has opened a wide area of investigation into the possible role of these molecules in human diseases. Superantigens produced by certain viruses and bacteria, including Mycoplasma species, are either secreted or membrane-bound proteins. A unique feature of these proteins is that they can interact simultaneously with distinct receptors on different types of cells, resulting in enhanced cell-cell interaction and triggering a series of biochemical reactions that can lead to excessive cell proliferation and the release of inflammatory cytokines. However, although superantigens share many features, they can have very different biological effects that are potentiated by host genetic and environmental factors. This review focuses on a group of secreted pyrogenic toxins that belong to the superantigen family and highlights some of their structural-functional features and their roles in diseases such as toxic shock and autoimmunity. Deciphering the biological activities of the various superantigens and understanding their role in the pathogenesis of microbial infections and their sequelae will enable us to devise means by which we can intervene with their activity and/or manipulate them to our advantage. PMID:7553574

  1. Bacterial Responses to Reactive Chlorine Species

    PubMed Central

    Gray, Michael J.; Wholey, Wei-Yun; Jakob, Ursula

    2013-01-01

    Hypochlorous acid (HOCl), the active ingredient of household bleach, is the most common disinfectant in medical, industrial, and domestic use and plays an important role in microbial killing in the innate immune system. Given the critical importance of the antimicrobial properties of chlorine to public health, it is surprising how little is known about the ways in which bacteria sense and respond to reactive chlorine species (RCS). Although the literature on bacterial responses to reactive oxygen species (ROS) is enormous, work addressing bacterial responses to RCS has begun only recently. Transcriptomic and proteomic studies now provide new insights into how bacteria mount defenses against this important class of antimicrobial compounds. In this review, we summarize the current knowledge, emphasizing the overlaps between RCS stress responses and other more well-characterized bacterial defense systems, and identify outstanding questions that represent productive avenues for future research. PMID:23768204

  2. Rate of bacterial mortality in aquatic environments

    SciTech Connect

    Servais, P.; Billen, G.; Rego, J.V.

    1985-06-01

    A method is proposed which provides a minimum estimate of the rate of bacterial mortality in growing natural populations of planktonic bacteria. This estimate is given by the rate of decrease of radioactivity from the DNA of a (/sup 3/H)thymidine-labeled natural assemblage of bacteria after all added thymidine has been exhausted from the medium. Results obtained from river water, estuarine water, and seawater show overall bacterial mortality rates in the range 0.010 to 0.030 h/sup -1/, in good agreement with the range of growth rates measured in the same environments. Use of selective filtration through Nuclepore filters (pore size, 2 ..mu..m) allowed us to determine the contribution of microzooplankton grazing to overall bacterial mortality. Grazing rates estimated by this method ranged from 0 to 0.02 h/sup -1/.

  3. Scanning electron microscopy studies of bacterial cultures

    NASA Astrophysics Data System (ADS)

    Swinger, Tracy; Blust, Brittni; Calabrese, Joseph; Tzolov, Marian

    2012-02-01

    Scanning electron microscopy is a powerful tool to study the morphology of bacteria. We have used conventional scanning electron microscope to follow the modification of the bacterial morphology over the course of the bacterial growth cycle. The bacteria were fixed in vapors of Glutaraldehyde and ruthenium oxide applied in sequence. A gold film of about 5 nm was deposited on top of the samples to avoid charging and to enhance the contrast. We have selected two types of bacteria Alcaligenes faecalis and Kocuria rhizophila. Their development was carefully monitored and samples were taken for imaging in equal time intervals during their cultivation. These studies are supporting our efforts to develop an optical method for identification of the Gram-type of bacterial cultures.

  4. Synthetic analogs of bacterial quorum sensors

    DOEpatents

    Iyer, Rashi S.; Ganguly, Kumkum; Silks, Louis A.

    2013-01-08

    Bacterial quorum-sensing molecule analogs having the following structures: ##STR00001## and methods of reducing bacterial pathogenicity, comprising providing a biological system comprising pathogenic bacteria which produce natural quorum-sensing molecule; providing a synthetic bacterial quorum-sensing molecule having the above structures and introducing the synthetic quorum-sensing molecule into the biological system comprising pathogenic bacteria. Further is provided a method of targeted delivery of an antibiotic, comprising providing a synthetic quorum-sensing molecule; chemically linking the synthetic quorum-sensing molecule to an antibiotic to produce a quorum-sensing molecule-antibiotic conjugate; and introducing the conjugate into a biological system comprising pathogenic bacteria susceptible to the antibiotic.

  5. Synthetic analogs of bacterial quorum sensors

    DOEpatents

    Iyer, Rashi (Los Alamos, NM); Ganguly, Kumkum (Los Alamos, NM); Silks, Louis A. (Los Alamos, NM)

    2011-12-06

    Bacterial quorum-sensing molecule analogs having the following structures: ##STR00001## and methods of reducing bacterial pathogenicity, comprising providing a biological system comprising pathogenic bacteria which produce natural quorum-sensing molecule; providing a synthetic bacterial quorum-sensing molecule having the above structures and introducing the synthetic quorum-sensing molecule into the biological system comprising pathogenic bacteria. Further is provided a method of targeted delivery of an antibiotic, comprising providing a synthetic quorum-sensing molecule; chemically linking the synthetic quorum-sensing molecule to an antibiotic to produce a quorum-sensing molecule-antibiotic conjugate; and introducing the conjugate into a biological system comprising pathogenic bacteria susceptible to the antibiotic.

  6. Bacterial vaginosis and the cervicovaginal immune response

    PubMed Central

    Mitchell, Caroline; Marrazzo, Jeanne

    2014-01-01

    Bacterial vaginosis (BV) is a common cause of vaginal discharge in reproductive age women around the world, and is associated with several poor reproductive health outcomes, including HIV-1 acquisition. One possible mechanism for this association is the inflammatory immune response induced by BV in the cervical and vaginal mucosae. There is significant heterogeneity in reports of markers of cervicovaginal inflammation in women with bacterial vaginosis, likely due to microbial and host diversity, as well as differences in study design. In this article we review the characteristics of the mucosal immune response in BV, the potential role of lactobacilli in modulating that response, and the impact of individual BV-associated bacterial species on mucosal immunity. We focus on inflammatory markers that are proposed to increase the risk of HIV-1 acquisition. PMID:24832618

  7. Bacterial imprinting at Pickering emulsion interfaces.

    PubMed

    Shen, Xiantao; Svensson Bonde, Johan; Kamra, Tripta; Bülow, Leif; Leo, Jack C; Linke, Dirk; Ye, Lei

    2014-09-26

    The tendency of bacteria to assemble at oil-water interfaces can be utilized to create microbial recognition sites on the surface of polymer beads. In this work, two different groups of bacteria were first treated with acryloyl-functionalized chitosan and then used to stabilize an oil-in-water emulsion composed of cross-linking monomers that were dispersed in aqueous buffer. Polymerization of the oil phase followed by removal of the bacterial template resulted in well-defined polymer beads bearing bacterial imprints. Chemical passivation of chitosan and cell displacement assays indicate that the bacterial recognition on the polymer beads was dependent on the nature of the pre-polymer and the target bacteria. The functional materials for microbial recognition show great potential for constructing cell-cell communication networks, biosensors, and new platforms for testing antibiotic drugs. PMID:25111359

  8. Gamma-irradiated bacterial preparation having anti-tumor activity

    DOEpatents

    Vass, Arpad A. (Oak Ridge, TN); Tyndall, Richard L. (Clinton, TN); Terzaghi-Howe, Peggy (Montrose, CO)

    1999-01-01

    A bacterial preparation from Pseudomonas species isolated #15 ATCC 55638 that has been exposed to gamma radiation exhibits cytotoxicity that is specific for neoplastic carcinoma cells. A method for obtaining a bacterial preparation having antitumor activity consists of suspending a bacterial isolate in media and exposing the suspension to gamma radiation. A bacterial preparation of an aged culture of an amoeba-associated bacteria exhibits anti-reverse transcriptase activity. A method for obtaining a bacterial preparation having anti-reverse transcriptase activity from an amoeba-associated bacterial isolate grown to stationary phase is disclosed.

  9. Bacterial and fungal pattern recognition receptors in homologous innate signaling pathways of insects and mammals

    PubMed Central

    Stokes, Bethany A.; Yadav, Shruti; Shokal, Upasana; Smith, L. C.; Eleftherianos, Ioannis

    2015-01-01

    In response to bacterial and fungal infections in insects and mammals, distinct families of innate immune pattern recognition receptors (PRRs) initiate highly complex intracellular signaling cascades. Those cascades induce a variety of immune functions that restrain the spread of microbes in the host. Insect and mammalian innate immune receptors include molecules that recognize conserved microbial molecular patterns. Innate immune recognition leads to the recruitment of adaptor molecules forming multi-protein complexes that include kinases, transcription factors, and other regulatory molecules. Innate immune signaling cascades induce the expression of genes encoding antimicrobial peptides and other key factors that mount and regulate the immune response against microbial challenge. In this review, we summarize our current understanding of the bacterial and fungal PRRs for homologous innate signaling pathways of insects and mammals in an effort to provide a framework for future studies. PMID:25674081

  10. Identification of Bacterial Protein O-Oligosaccharyltransferases and Their Glycoprotein Substrates

    PubMed Central

    Jones, Christopher E.; Fox, Kate L.; Ku, Shan C.; Blanchfield, Joanne T.; Jennings, Michael P.

    2013-01-01

    O-glycosylation of proteins in Neisseria meningitidis is catalyzed by PglL, which belongs to a protein family including WaaL O-antigen ligases. We developed two hidden Markov models that identify 31 novel candidate PglL homologs in diverse bacterial species, and describe several conserved sequence and structural features. Most of these genes are adjacent to possible novel target proteins for glycosylation. We show that in the general glycosylation system of N. meningitidis, efficient glycosylation of additional protein substrates requires local structural similarity to the pilin acceptor site. For some Neisserial PglL substrates identified by sensitive analytical approaches, only a small fraction of the total protein pool is modified in the native organism, whereas others are completely glycosylated. Our results show that bacterial protein O-glycosylation is common, and that substrate selection in the general Neisserial system is dominated by recognition of structural homology. PMID:23658772

  11. Exoproteinases of the type A in pathogenesis of insect bacterial diseases.

    PubMed

    Andrejko, M

    1999-01-01

    Immune inhibitors produced in infected larvae of Galleria mellonella by such entomopathogens as Pseudomonas aeruginosa, Serratia marcescens and Heterorhabditis bacteriophora effectively blocked in vitro bactericidal activity of insect haemolymph against Escherichia coli D31, both in Galleria mellonella and Pieris brassicae pupae previously vaccinated with Enterobacter cloacae. Even at a trace concentration, the extracellular proteinases, by proteolytic degradation, totally destroyed the activity of cecropin peptides from Galleria and cecropin-like and attacin-family proteins from Pieris, but no ability to destroy antibacterial activity was shown by extracts obtained from Galleria larvae killed by massive doses of bacterial saprophytes. It is suggested that by blocking antibacterial immune response of the host, the proteinases help the bacteria to multiply in the haemolymph, thus they could be considered an important factor in the pathogenesis of bacterial diseases of insects. PMID:10754793

  12. Assessment of Troubled Families.

    ERIC Educational Resources Information Center

    Combs-Orme, Terri; Thomas, Katherine H.

    1997-01-01

    Tests the utility of four standardized instruments used in assessing 105 families that sought services in a juvenile corrections setting for their teenage children. Results demonstrate that parents and adolescents can complete standardized assessment instruments and that the information provided can help in understanding distressed families. (RJM)

  13. The Family Constellation Scale.

    ERIC Educational Resources Information Center

    Lemire, David

    The Family Constellation Scale (FC Scale) is an instrument that assesses perceived birth order in families. It can be used in counseling to help initiate conversations about various traits and assumptions that tend to characterize first-born, middle-born children, youngest-born, and only children. It provides both counselors and clients insights…

  14. Family-Friendly Art

    ERIC Educational Resources Information Center

    Williams, Patterson; Garcia, Maria

    2004-01-01

    In the late 1980s, the Denver Art Museum initiated efforts to make the museum a destination for families. From 1997 to 2001, with a generous grant from The Pew Charitable Trusts, these efforts came to fruition. From the moment they walk through the doors, families' needs are anticipated. For example, they can pick up a welcoming brochure, Free…

  15. Family History Resources.

    ERIC Educational Resources Information Center

    Bookmark, 1991

    1991-01-01

    The 12 articles in this issue focus on the theme of family history resources: (1) "Introduction: Family History Resources" (Joseph F. Shubert); (2) "Work, Credentials, and Expectations of a Professional Genealogist" (Coreen P. Hallenbeck and Lewis W. Hallenbeck); (3) "Computers and Genealogy" (Theresa C. Strasser); (4) "Finding Historical Records…

  16. Black Families. Interdisciplinary Perspectives.

    ERIC Educational Resources Information Center

    Cheatham, Harold E., Ed.; Stewart, James B., Ed.

    Since the early 1960s, the black family has been characterized as pathological. This six-part collection of 18 research studies presents alternative approaches to understanding the special characteristics of black families. Part I, "Theoretical and Methodological Perspectives," comprises a comparison of the pioneering work of W. E. B. Du Bois and…

  17. Marinating the Family.

    ERIC Educational Resources Information Center

    Hensel, Karen A.

    1982-01-01

    Describes the New York Aquarium's program specifically designed for family learning and teaching. The program's goal is to create an environment where child-parent roles are dropped and where the philosophy that no one of us is as smart as all of us prevails. Strategies for family involvement are outlined. (MH)

  18. Explaining Family Interactions.

    ERIC Educational Resources Information Center

    Fitzpatrick, Mary Anne, Ed.; Vangelisti, Anita L., Ed.

    A detailed review of current research and state-of-the-art ideas concerning both communication processes and family functioning is presented in this collection of articles. The volume is organized around three sections. Part 1, "The Development of Family Communication Patterns," contains: (1) "Communication in Infancy" (Marguerite Stevenson…

  19. Golden Matrix Families

    ERIC Educational Resources Information Center

    Fontaine, Anne; Hurley, Susan

    2011-01-01

    This student research project explores the properties of a family of matrices of zeros and ones that arises from the study of the diagonal lengths in a regular polygon. There is one family for each n greater than 2. A series of exercises guides the student to discover the eigenvalues and eigenvectors of the matrices, which leads in turn to…

  20. Family Support and Education

    ERIC Educational Resources Information Center

    Goldstein, Lou Ann

    2013-01-01

    Family involvement is essential to the developmental outcome of infants born into Neonatal Intensive Care Unit (NICU). In this article, evidence has been presented on the parent's perspective of having an infant in the NICU and the context of family. Key points to an educational assessment are also reviewed. Throughout, the parent's concerns and…

  1. [Inclusive Recreation and Families.

    ERIC Educational Resources Information Center

    Heyne, Linda A., Ed.; And Others

    1996-01-01

    This feature issue focuses on inclusive recreation for persons with developmental disabilities and their families. The articles provide information about the benefits of inclusive recreation for individuals and families, the challenges in attempting to create or access community recreation services that offer inclusive programs, and strategies…

  2. Familial Gestational Trophoblastic Disease

    Microsoft Academic Search

    M. Fallahian

    2003-01-01

    Familial molar pregnancies and gestational trophoblastic disease are exceedingly rare. In this case report, a family including four sisters and their cousin had molar pregnancies. Eldest sister had repeated molar pregnancies. Second sister had early abortion at her first pregnancy and partial molar pregnancy following blighted ovum by intrauterine insemination at her second pregnancy. Third sister had two molar pregnancies

  3. IGSF9 family proteins.

    PubMed

    Hansen, Maria; Walmod, Peter Schledermann

    2013-06-01

    The Drosophila protein Turtle and the vertebrate proteins immunoglobulin superfamily (IgSF), member 9 (IGSF9/Dasm1) and IGSF9B are members of an evolutionarily ancient protein family. A bioinformatics analysis of the protein family revealed that invertebrates contain only a single IGSF9 family gene, whereas vertebrates contain two to four genes. In cnidarians, the gene appears to encode a secreted protein, but transmembrane isoforms of the protein have also evolved, and in many species, alternative splicing facilitates the expression of both transmembrane and secreted isoforms. In most species, the longest isoforms of the proteins have the same general organization as the neural cell adhesion molecule family of cell adhesion molecule proteins, and like this family of proteins, IGSF9 family members are expressed in the nervous system. A review of the literature revealed that Drosophila Turtle facilitates homophilic cell adhesion. Moreover, IGSF9 family proteins have been implicated in the outgrowth and branching of neurites, axon guidance, synapse maturation, self-avoidance, and tiling. However, despite the few published studies on IGSF9 family proteins, reports on the functions of both Turtle and mammalian IGSF9 proteins are contradictory. PMID:23417431

  4. Alcoholism and Family Interaction.

    ERIC Educational Resources Information Center

    Jacob, Theodore

    Historically, alcoholism has been defined as an individual problem, and as a result, family factors have received little attention. During the past decade, however, a new theoretical-methodological perspective has been introduced which draws upon general systems theory for rationale, family theory for substance, and behavioral psychology for…

  5. Family/Individual Health.

    ERIC Educational Resources Information Center

    Texas Tech Univ., Lubbock. Home Economics Curriculum Center.

    This document contains teacher's materials for a six-unit secondary education vocational home economics course on personal and family health. The units cover: (1) personal health and wellness (including the decisions and other factors that influence health, principles of personal health, and stress management); (2) family health (including coping…

  6. Ontogeny in the Family

    Microsoft Academic Search

    Mathias Kölliker

    2005-01-01

    When ontogeny takes place in a family, and parents provide essential resources for development, the parents become an environmental component to the development of a wide range of offspring traits. Because differences among parents may partly reflect genetic variation, this environmental component contains genes and may itself evolve. Also, when offspring play an active role in family interactions, offspring become

  7. Adlerian Family Therapy.

    ERIC Educational Resources Information Center

    Dinkmeyer, Don; Dinkmeyer, Don, Jr.

    1981-01-01

    Discusses the competencies basic to Adlerian therapy--including influencing psychological movement, working with the family communication system, focusing on the real issue, aligning goals and dealing with resistance, stimulating social interest, encouragement, and tentative hypotheses, and antisuggestion. A specific process for helping the family

  8. Democratization of the Family.

    ERIC Educational Resources Information Center

    Beck, Ulrich

    1997-01-01

    Discusses several issues related to a modern approach in the interpretation of civil freedom and its relationship to the notion of family. First, presents some definitions and distinctions regarding the sociology of political freedom, which it suggests should become the sociology of citizenship. Then, applies those ideas to families, particularly…

  9. The Nkosi Family.

    ERIC Educational Resources Information Center

    Lyster, Elda

    This book for beginning readers presents the story of the South African Nkosi family. The seven members of the family share their feelings, likes and dislikes, and hopes and dreams. Readers are encouraged to figure out what the characters like, want, feel, and dream and to share their own likes, desires, feelings, and dreams. The book is written…

  10. Child And Family Studies Department Of Child And Family Studies

    E-print Network

    Mather, Patrick T.

    Child And Family Studies Department Of Child And Family Studies Robert P. Moreno, Chair, 315 of Child and Family Studies (CFS) is involved in the scientific investigation of children and families of specialization: (a) Early Child Development, (b) Youth and Family Development, (c) Early Childhood Education (4

  11. Families First: Keys to Successful Family Functioning An Introduction

    E-print Network

    Liskiewicz, Maciej

    families promote the emotional, physical and social welfare of individual family members. Among the many unit. Unlike any other social group, families are able to provide the close emotional support needed, physical, and social development of individual family members Healthy families are able to cope

  12. Engaging Families in In-Home Family Intervention

    ERIC Educational Resources Information Center

    Thompson, Ronald W.; Koley, Sarah

    2014-01-01

    Boys Town has created a program called In-Home Family Services to deliver help to families in stress. In-home family intervention programs have become widely used to help more families who are at risk and experiencing difficulties with a wide range of problems including domestic violence, child behavior problems, parent-child and family

  13. Family Learning Forum

    NSDL National Science Digital Library

    How do families learn together when they come to a museum? It's a little-explored question, and one that staff members at the USS Constitution Museum in Boston were interested in exploring. In 2004, they started the Family Learning Project with support via a grant from the Institute of Museum and Library Services to explore this matter, along with looking at effective, low-cost exhibit techniques. The museum studied their own "Sailors Speak" exhibition, in order to answer questions that included: "What kinds of historical text could engage families most effectively?" A basic overview of their mission can be found in the "About" area, and then visitors will want to look over their findings in sections like "10 Steps to Encourage Family Learning" and "Developing Content to Engage Families".

  14. Production of Bacterial Cellulose from Alternate Feedstocks

    SciTech Connect

    Thompson, David Neil; Hamilton, Melinda Ann

    2000-05-01

    Production of bacterial cellulose by Acetobacter xylinum ATCC 10821 and 23770 in static cultures was tested from unamended food process effluents. Effluents included low- and high-solids potato effluents (LS & HS), cheese whey permeate (CW), and sugar beet raffinate (CSB). Strain 23770 produced 10% less cellulose from glucose than did 10821, and diverted more glucose to gluconate. Unamended HS, CW, and CSB were unsuitable for cellulose production by either strain, while LS was unsuitable for production by 10821. However, 23770 produced 17% more cellulose from LS than from glucose, indicating unamended LS could serve as a feedstock for bacterial cellulose.

  15. Production of bacterial cellulose from alternate feedstocks

    SciTech Connect

    D. N. Thompson; M. A. Hamilton

    2000-05-07

    Production of bacterial cellulose by Acetobacter xylinum ATCC 10821 and 23770 in static cultures was tested from unamended food process effluents. Effluents included low- and high-solids potato effluents (LS and HS), cheese whey permeate (CW), and sugar beet raffinate (CSB). Strain 23770 produced 10% less cellulose from glucose than did 10821, and diverted more glucose to gluconate. Unamended HS, CW, and CSB were unsuitable for cellulose production by either strain, while LS was unsuitable for production by 10821. However, 23770 produced 17% more cellulose from LS than from glucose, indicating unamended LS could serve as a feedstock for bacterial cellulose.

  16. Some problems of bacterial mineralization and sedimentation

    NASA Astrophysics Data System (ADS)

    Rozanov, Alexei Y.

    2003-01-01

    Owing to the latest investigations in bacterial paleontology and geomicrobiology a number of minerals known to be formed with the participation of micro-organisms increases continuously. 12 - 15 years ago we know nearly 20 minerals: carbonates (calcite, aragonite, monohydrocalcite), phosphates (dalite, francolite, struvite, vivianite, and some other), sulfates (jarosite), ferric oxides (magnetite, ferrohydrite), sulfides (pyrite, hydrotroilite, sphalerite, wurtzite, and some others) (Lowernstan, Weiner, 1989). Now their number is several times greater. Quartz cristobalite, pyrolusite, silicates (including layer ones), and feldspars are of special interest (Geomicrobiology..., 1997; Tazaki et al., 1997; Geptner et al., 1997; Bacterial paleontology, 2002).

  17. [Bacterial vaginosis. Treatment of the relapse].

    PubMed

    Malinova, M

    2012-01-01

    Bacterial vaginosis (BV) is a common vaginal infection in women of reproductive age. Bacterial vaginosis is an ecological disorder that ensues when normal lactobacilli are replaced by large numbers of Gardnerella vaginalis, Prevotella sp., Bacteroides sp., Mobiluncus sp. and M. hominis. Numerous studies have consistently shown that BV at 12-24 weeks are associated with increased risks of preterm birth (PTB), preterm rupture of the membranes, chorioamnionitis, fetal infection and cerebral palsy. Deficiencies in local immunity may predispose women to BV. PMID:23236675

  18. Bifunctional bacterial magnetic nanoparticles for tumor targeting

    NASA Astrophysics Data System (ADS)

    Guo, Lin; Huang, Ji; Zheng, Li-Min

    2012-01-01

    Bifunctional bacterial magnetic nanoparticles (BBMPs), which present both magnetic drug targeting and tumor bio-targeting properties, have been developed by chemically coupling both doxorubicin and a galactosyl ligand on to the membrane surface of the bacterial magnetic nanoparticles (BMPs). The BBMP product has a high drug load ratio and magnetic respondence, and exhibits a narrow size distribution and is sensitive to pH to enable drug release. In comparison to doxorubicin-coupled BMPs, without modification with a galactosyl ligand, BBMPs present a higher uptake by the target asialoglycoprotein receptor (ASGP-R) expressed by HepG2 cells and display stronger cytotoxicity.

  19. Medically important bacterial-fungal interactions.

    PubMed

    Peleg, Anton Y; Hogan, Deborah A; Mylonakis, Eleftherios

    2010-05-01

    Whether it is in the setting of disease or in a healthy state, the human body contains a diverse range of microorganisms, including bacteria and fungi. The interactions between these taxonomically diverse microorganisms are highly dynamic and dependent on a multitude of microorganism and host factors. Human disease can develop from an imbalance between commensal bacteria and fungi or from invasion of particular host niches by opportunistic bacterial and fungal pathogens. This Review describes the clinical and molecular characteristics of bacterial-fungal interactions that are relevant to human disease. PMID:20348933

  20. A Bacterial Iron Exporter for Maintenance of Iron Homeostasis*

    PubMed Central

    Sankari, Siva; O'Brian, Mark R.

    2014-01-01

    Nutritional iron acquisition by bacteria is well described, but almost nothing is known about bacterial iron export even though it is likely to be an important homeostatic mechanism. Here, we show that Bradyrhizobium japonicum MbfA (Blr7895) is an inner membrane protein expressed in cells specifically under high iron conditions. MbfA contains an N-terminal ferritin-like domain (FLD) and a C-terminal domain homologous to the eukaryotic vacuolar membrane Fe2+/Mn2+ transporter CCC1. An mbfA deletion mutant is severely defective in iron export activity, contains >2-fold more intracellular iron than the parent strain, and displays an aberrant iron-dependent gene expression phenotype. B. japonicum is highly resistant to iron and H2O2 stresses, and MbfA contributes substantially to this as determined by phenotypes of the mbfA mutant strain. The N-terminal FLD was localized to the cytoplasmic side of the inner membrane. Substitution mutations in the putative iron-binding amino acid residues E20A and E107A within the N-terminal FLD abrogate iron export activity and stress response function. Purified soluble FLD oxidizes ferrous iron (Fe2+) to incorporate ferric iron (Fe3+) in a 2:1 iron:protein ratio, which does not occur in the E20A/E107A mutant. The FLD fragment is a dimer in solution, implying that the MbfA exporter functions as a dimer. MbfA belongs to a protein family found in numerous prokaryotic genera. The findings strongly suggest that iron export plays an important role in bacterial iron homeostasis. PMID:24782310

  1. Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates.

    PubMed Central

    Anderson, A J; Dawes, E A

    1990-01-01

    Polyhydroxyalkanoates (PHAs), of which polyhydroxybutyrate (PHB) is the most abundant, are bacterial carbon and energy reserve materials of widespread occurrence. They are composed of 3-hydroxyacid monomer units and exist as a small number of cytoplasmic granules per cell. The properties of the C4 homopolymer PHB as a biodegradable thermoplastic first attracted industrial attention more than 20 years ago. Copolymers of C4 (3-hydroxybutyrate [3HB]) and C5 (3-hydroxyvalerate [3HV]) monomer units have modified physical properties; e.g., the plastic is less brittle than PHB, whereas PHAs containing C8 to C12 monomers behave as elastomers. This family of materials is the centre of considerable commercial interest, and 3HB-co-3HV copolymers have been marketed by ICI plc as Biopol. The known polymers exist as 2(1) helices with the fiber repeat decreasing from 0.596 nm for PHB to about 0.45 nm for C8 to C10 polymers. Novel copolymers with a backbone of 3HB and 4HB have been obtained. The native granules contain noncrystalline polymer, and water may possibly act as a plasticizer. Although the biosynthesis and regulation of PHB are generally well understood, the corresponding information for the synthesis of long-side-chain PHAs from alkanes, alcohols, and organic acids is still incomplete. The precise mechanisms of action of the polymerizing and depolymerizing enzymes also remain to be established. The structural genes for the three key enzymes of PHB synthesis from acetyl coenzyme A in Alcaligenes eutrophus have been cloned, sequenced, and expressed in Escherichia coli. Polymer molecular weights appear to be species specific. The factors influencing the commercial choice of organism, substrate, and isolation process are discussed. The physiological functions of PHB as a reserve material and in symbiotic nitrogen fixation and its presence in bacterial plasma membranes and putative role in transformability and calcium signaling are also considered. PMID:2087222

  2. The NLRC4 inflammasome receptors for bacterial flagellin and type III secretion apparatus.

    PubMed

    Zhao, Yue; Yang, Jieling; Shi, Jianjin; Gong, Yi-Nan; Lu, Qiuhe; Xu, Hao; Liu, Liping; Shao, Feng

    2011-09-29

    Inflammasomes are large cytoplasmic complexes that sense microbial infections/danger molecules and induce caspase-1 activation-dependent cytokine production and macrophage inflammatory death. The inflammasome assembled by the NOD-like receptor (NLR) protein NLRC4 responds to bacterial flagellin and a conserved type III secretion system (TTSS) rod component. How the NLRC4 inflammasome detects the two bacterial products and the molecular mechanism of NLRC4 inflammasome activation are not understood. Here we show that NAIP5, a BIR-domain NLR protein required for Legionella pneumophila replication in mouse macrophages, is a universal component of the flagellin-NLRC4 pathway. NAIP5 directly and specifically interacted with flagellin, which determined the inflammasome-stimulation activities of different bacterial flagellins. NAIP5 engagement by flagellin promoted a physical NAIP5-NLRC4 association, rendering full reconstitution of a flagellin-responsive NLRC4 inflammasome in non-macrophage cells. The related NAIP2 functioned analogously to NAIP5, serving as a specific inflammasome receptor for TTSS rod proteins such as Salmonella PrgJ and Burkholderia BsaK. Genetic analysis of Chromobacterium violaceum infection revealed that the TTSS needle protein CprI can stimulate NLRC4 inflammasome activation in human macrophages. Similarly, CprI is specifically recognized by human NAIP, the sole NAIP family member in human. The finding that NAIP proteins are inflammasome receptors for bacterial flagellin and TTSS apparatus components further predicts that the remaining NAIP family members may recognize other unidentified microbial products to activate NLRC4 inflammasome-mediated innate immunity. PMID:21918512

  3. Canadian Families (Les Familles Canadiennes).

    ERIC Educational Resources Information Center

    Vanier Inst. of the Family, Ottawa (Ontario).

    Structural changes that have taken place in Canadian families in recent decades are described in this booklet. Topical sections are as follows: (1) What Counts in Canadian Families (importance of (importance of family); (2) The Family--Variations on a Theme origins, family structure, seniors aged 60 and over, how lives are spent, religion); (3)…

  4. Family Day Care Training Curriculum.

    ERIC Educational Resources Information Center

    Nakatsu, Gail

    California's Family Day Care Training Program was designed to recruit and train in 7 weeks, Lao, Vietnamese, and Chinese refugees to establish their own state-licensed, family day care homes. Topics in the program's curriculum include an introduction to family day care, state licenses for family day care, state licensing requirements for family

  5. Does Addiction Run in Families?

    MedlinePLUS

    Listen to this page Does Addiction Run in Families? Addiction can run in families. If people in your family have addictions, you are more likely to become ... En espańol "Heart disease runs in some families. Addiction runs in ours." Matt's family has a history ...

  6. Lights, Camera--Families--Action!

    ERIC Educational Resources Information Center

    Press, Doreen

    2000-01-01

    Discusses the family night concert as a way to involve family members in music education, where they can participate in the orchestra or as part of a family act. Describes how to create the family concert. Includes a sample invitation and a program to a family night performance. (CMK)

  7. Family Oriented Geographic Field Experience.

    ERIC Educational Resources Information Center

    Williams, Karen Ann Lalk

    This paper describes a program of geographic education through field experience trips for family groups. Developed at Delta College in Michigan, the approach is unique because it emphasizes learning experiences for families rather than for individual students. The family is interpreted to include nuclear families, single-parent families with…

  8. Ruminal bacterial community shifts in grain-, sugar-, and histidine-challenged dairy heifers.

    PubMed

    Golder, H M; Denman, S E; McSweeney, C; Celi, P; Lean, I J

    2014-08-01

    Ruminal bacterial community composition (BCC) and its associations with ruminal fermentation measures were studied in dairy heifers challenged with combinations of grain, fructose, and histidine in a partial factorial study. Holstein-Friesian heifers (n=30) were randomly allocated to 5 triticale grain-based treatment groups: (1) control (no grain), (2) grain [fed at a dry matter intake (DMI) of 1.2% of body weight (BW)], (3) grain (0.8% of BW DMI) + fructose (0.4% of BW DMI), (4) grain (1.2% of BW DMI) + histidine (6g/head), and (5) grain (0.8% of BW DMI) + fructose (0.4% of BW DMI) + histidine (6g/head). Ruminal fluid was collected using a stomach tube 5, 115, and 215min after consumption of the rations and bacterial 16S ribosomal DNA sequence data was analyzed to characterize bacteria. Large variation among heifers and distinct BCC were evident in a between-group constrained principal components analysis. Bacterial composition in the fructose-fed heifers was positively related to total lactate and butyrate concentrations. Bacterial composition was positively associated with ruminal ammonia, valerate, and histamine concentrations in the grain-fed heifers. The predominant phyla were the Firmicutes (57.6% of total recovered sequences), Bacteroidetes (32.0%), and candidate phylum TM7 (4.0%). Prevotella was the dominant genus. In general, grain or histidine or their interactions with time had minimal effects on the relative abundance of bacterial phyla and families. Fructose increased and decreased the relative abundance of the Firmicutes and Proteobacteria phyla over time, respectively, and decreased the abundance of the Prevotellaceae family over time. The relative abundance of the Streptococcaceae and Veillonellaceae families was increased in the fructose-fed heifers and these heifers over time. A total of 31 operational taxonomic units differed among treatment groups in the 3.6h sampling period, Streptococcus bovis was observed in fructose fed animals. The TM7 candidate phylum had an increased abundance of sequence reads by over 2.5 fold due to the introduction of histidine into the diet. Rapid changes in BCC can occur in a short period after a single substrate challenge and the nature of these changes may influence ruminal acidosis risk and differ from those in cattle exposed to substrate challenges over a longer time period. PMID:24881800

  9. Wnt2 inhibits enteric bacterial-induced inflammation in intestinal epithelial cells

    PubMed Central

    Liu, Xingyin; Lu, Rong; Wu, Shaoping; Zhang, Yong-guo; Xia, Yinglin; Sartor, R. Balfour; Sun, Jun

    2012-01-01

    Background Wnt signaling plays an essential role in gastrointestinal epithelial proliferation. Most investigations have focused on developmental and immune responses. Bacterial infection can be chronic and increases the risk of inflammatory bowel disease and colitis-associated cancer. However, we lack studies on how bacteria regulate Wnt proteins and how Wnts modulate the host responses to enteric bacteria. This study investigated the effects of Salmonella and E. coli on Wnt2, one of the Wnt family members, in intestinal epithelia cells. Methodology/Findings Using cultured epithelial cells, a Salmonella-colitis mouse model, and a gnotobiotic mouse model, we found that Wnt2 mRNA and protein expression levels were elevated after bacterial infection. Enteric bacteria regulate Wnt2 location in the intestine. Furthermore, we found that elevation of Wnt2 was a strategy for host defense by inhibiting cell apoptosis and inflammatory responses to infection. Using Wnt2 siRNA analysis, we show enhanced inflammatory cytokine IL-8 in epithelial cells. Cells over-expressed Wnt2 had less bacterial-induced IL-8 secretion. AvrA is a bacterial protein that inhibits inflammation by stabilizing beta-catenin, the down-stream target of Wnt. We found that the stabilization of Wnt2 was regulated through ubiquitination. Moreover, the bacterial protein AvrA from Salmonella and E. coli stabilized Wnt2 protein expression in vivo. In an ex-germ-free system, E. coli F18 expressing AvrA increased Wnt2 expression and changed Wnt2 distribution in intestine. Conclusion Wnt2 contributes to host protection in response to enteric bacteria. Our findings thus reveal a previously undefined role of Wnt for host-pathogen interaction and inflammation. PMID:21674728

  10. Biofilm forming ability of a new bacterial isolate from dental caries: An atomic force microscopic study

    PubMed Central

    Arul, A. Sri Kennath J.; Palanivelu, Peramachi

    2014-01-01

    Background: Dental plaque being one of the most-studied biofilm communities, is particularly complex because it consists of thousands of bacterial species, and new species are still being isolated and characterized. The aim of the present study is to characterize surface topography of the biofilm formed by a new bacterial isolate, obtained from the dental caries lesion using atomic force microscopy. Materials and Methods: Ten clinical isolates were obtained from five teeth with carious lesions involving dentine. Quantification of the biofilm forming ability of the clinical isolates was performed using microtiter plate assay. Bacterial isolate exhibiting maximum biofilm formation was subjected to phylogenetic analysis based on 16S rRNA gene sequencing and atomic force microscopic analysis. Results: The bacterial strain JKAS-CD2 displayed the highest similarity to 16S rRNA gene sequences of members of the family Streptococcaceae. It shared 95.3-99.3% similarity to the type strains of genus Streptococcus and 99.9% sequence similarity to the type strain Streptococcus infantarius. Atomic Force Microscopic analysis confirmed that the sucrose dependent bacterial adhesion for stable biofilm development has increased over a time-span on the thin film of enamel. Major structural components of plaque such as clumping of colonies and slime layer were clearly visualized by surface image of JKAS-CD2 cells grown on the enamel powder coated glass surface. Conclusion: JKAS-CD2 emerged as an obligate biofilm forming microbe under sucrose-dependent condition; a mechanism for adherence that determines the survival and persistence of the bacteria in the oral cavity and thus implicated with the dental caries. PMID:25097398

  11. Identification of Bacterial Groups Preferentially Associated with Mycorrhizal Roots of Medicago truncatula?

    PubMed Central

    Offre, P.; Pivato, B.; Siblot, S.; Gamalero, E.; Corberand, T.; Lemanceau, P.; Mougel, C.

    2007-01-01

    The genetic structures of bacterial communities associated with Medicago truncatula Gaertn. cv. Jemalong line J5 (Myc+ Nod+) and its symbiosis-defective mutants TRV48 (Myc+ Nod?) and TRV25 (Myc? Nod?) were compared. Plants were cultivated in a fertile soil (Châteaurenard, France) and in soil from the Mediterranean basin showing a low fertility (Mas d'Imbert, France). Plant growth, root architecture, and the efficiency of root symbiosis of the three plant genotypes were characterized in the two soils. Structures of the bacterial communities were assessed by automated-ribosomal intergenic spacer analysis (A-RISA) fingerprinting from DNA extracted from the rhizosphere soil and root tissues. As expected, the TRV25 mutant did not develop endomycorrhizal symbiosis in any of the soils, whereas mycorrhization of line J5 and the TRV48 mutant occurred in both soils but at a higher intensity in the Mas d'Imbert (low fertility) than in the Châteaurenard soil. However, modifications of plant growth and root architecture, between mycorrhizal (J5 and TRV48) and nonmycorrhizal (TRV25) plants, were recorded only when cultivated in the Mas d'Imbert soil. Similarly, the genetic structures of bacterial communities associated with mycorrhizal and nonmycorrhizal plants differed significantly in the Mas d'Imbert soil but not in the Châteaurenard soil. Multivariate analysis of the patterns allowed the identification of molecular markers, explaining these differences, and markers were further sequenced. Molecular marker analysis allowed the delineation of 211 operational taxonomic units. Some of those belonging to the Comamonadaceae and Oxalobacteraceae (?-Proteobacteria) families were found to be significantly more represented within bacterial communities associated with the J5 line and the TRV48 mutant than within those associated with the TRV25 mutant, indicating that these bacterial genera were preferentially associated with mycorrhizal roots in the Mas d'Imbert soil. PMID:17142371

  12. Characterization of the bacterial biodiversity in Pico cheese (an artisanal Azorean food).

    PubMed

    Riquelme, Cristina; Câmara, Sandra; Dapkevicius, Maria de Lurdes N Enes; Vinuesa, Pablo; da Silva, Célia Costa Gomes; Malcata, F Xavier; Rego, Oldemiro A

    2015-01-01

    This work presents the first study on the bacterial communities in Pico cheese, a traditional cheese of the Azores (Portugal), made from raw cow's milk. Pyrosequencing of tagged amplicons of the V3-V4 regions of the 16S rDNA and Operational Taxonomic Unit-based (OTU-based) analysis were applied to obtain an overall idea of the microbiota in Pico cheese and to elucidate possible differences between cheese-makers (A, B and C) and maturation times. Pyrosequencing revealed a high bacterial diversity in Pico cheese. Four phyla (Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes) and 54 genera were identified. The predominant genus was Lactococcus (77% of the sequences). Sequences belonging to major cheese-borne pathogens were not found. Staphylococcus accounted for 0.5% of the sequences. Significant differences in bacterial community composition were observed between cheese-maker B and the other two units that participated in the study. However, OTU analysis identified a set of taxa (Lactococcus, Streptococcus, Acinetobacter, Enterococcus, Lactobacillus, Staphylococcus, Rothia, Pantoea and unclassified genera belonging to the Enterobacteriaceae family) that would represent the core components of artisanal Pico cheese microbiota. A diverse bacterial community was present at early maturation, with an increase in the number of phylotypes up to 2 weeks, followed by a decrease at the end of ripening. The most remarkable trend in abundance patterns throughout ripening was an increase in the number of sequences belonging to the Lactobacillus genus, with a concomitant decrease in Acinetobacter, and Stenotrophomonas. Microbial rank abundance curves showed that Pico cheese's bacterial communities are characterized by a few dominant taxa and many low-abundance, highly diverse taxa that integrate the so-called "rare biosphere". PMID:25440551

  13. Microfluidic Systems for Investigating Bacterial Chemotaxis and Colonization

    E-print Network

    Englert, Derek Lynn

    2011-02-22

    The overall goal of this work was to develop and utilize microfluidic models for investigating bacterial chemotaxis and biofilm formation - phenotypes that play key roles in bacterial infections. Classical methods for investigating chemotaxis...

  14. Microfluidic Systems for Investigating Bacterial Chemotaxis and Colonization 

    E-print Network

    Englert, Derek Lynn

    2011-02-22

    The overall goal of this work was to develop and utilize microfluidic models for investigating bacterial chemotaxis and biofilm formation - phenotypes that play key roles in bacterial infections. Classical methods for investigating chemotaxis...

  15. Risk of Bacterial Meningitis in Children with Cochlear Implants

    MedlinePLUS

    ... Makers Risk of Bacterial Meningitis in Children with Cochlear Implants Language: English Espańol (Spanish) Recommend on Facebook Tweet ... the Risk of Bacterial Meningitis in Children with Cochlear Implants Many people have received cochlear implants to help ...

  16. 40 CFR 799.9510 - TSCA bacterial reverse mutation test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... false TSCA bacterial reverse mutation test. 799.9510 Section 799.9510 Protection...MIXTURE TESTING REQUIREMENTS Health Effects Test Guidelines § 799.9510 TSCA bacterial reverse mutation test. (a) Scope. This section is...

  17. 40 CFR 799.9510 - TSCA bacterial reverse mutation test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... false TSCA bacterial reverse mutation test. 799.9510 Section 799.9510 Protection...MIXTURE TESTING REQUIREMENTS Health Effects Test Guidelines § 799.9510 TSCA bacterial reverse mutation test. (a) Scope. This section is...

  18. 40 CFR 799.9510 - TSCA bacterial reverse mutation test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... false TSCA bacterial reverse mutation test. 799.9510 Section 799.9510 Protection...MIXTURE TESTING REQUIREMENTS Health Effects Test Guidelines § 799.9510 TSCA bacterial reverse mutation test. (a) Scope. This section is...

  19. Combinatorial discovery of polymers resistant to bacterial attachment

    E-print Network

    Hook, Andrew L

    Bacterial attachment and subsequent biofilm formation pose key challenges to the optimal performance of medical devices. In this study, we determined the attachment of selected bacterial species to hundreds of polymeric ...

  20. ISOLATION AND PURIFICATION OF BACTERIAL DNA FROM SOIL

    EPA Science Inventory

    Recently, new methods for monitoring specific bacterial populations in environmental samples have become available. These methods employ the techniques of molecular biology to distinguish, enumerate and monitor individual bacterial populations within a microbial community by the ...

  1. Bacterial persistence: finding the "sweet spot".

    PubMed

    Roop, R Martin; Caswell, Clayton C

    2013-08-14

    Studies described by Eisele et al. (2013) and Xavier et al. (2013) in this issue of Cell Host & Microbe show that the bacterial pathogens Salmonella and Brucella exploit the increased levels of glucose present in alternatively activated macrophages to sustain chronic infections in experimentally infected mice. PMID:23954150

  2. Making sense of it all: bacterial chemotaxis

    Microsoft Academic Search

    George H. Wadhams; Judith P. Armitage

    2004-01-01

    Bacteria must be able to respond to a changing environment, and one way to respond is to move. The transduction of sensory signals alters the concentration of small phosphorylated response regulators that bind to the rotary flagellar motor and cause switching. This simple pathway has provided a paradigm for sensory systems in general. However, the increasing number of sequenced bacterial

  3. Selective Inhibitors of Bacterial DNA Adenine Methyltransferases

    E-print Network

    Reich, Norbert O.

    - sis, it is essential for the virulence of Salmonella serovar Typhymurium in a murine model of typhoid methyltransferases. These enzymes are essential for bacterial virulence (DNA adenine methyltransferase [DAM virulence and viability.3 S-Adenosylmethionine (AdoMet)­ dependent methylation is the most common form

  4. Influence of topology on bacterial social interaction

    E-print Network

    Yuzbashyan, Emil

    medium behaves as a Brownian particle. A wild-type bacterium E. coli executing a random walk. #12;Is many Diffusion. J ­ current of bacteria, ­ bacterial density, c ­ attractant concentration, a ­ growth rate, Db secreted by other bacteria. Need another equation for the attractant concentration c. += cD t c c 2

  5. Oral bacterial adhesion on amorphous carbon films

    Microsoft Academic Search

    A. Almaguer-Flores; R. Olivares-Navarrete; A. Lechuga-Bernal; L. A. Ximénez-Fyvie; S. E. Rodil

    2009-01-01

    It is now well established that all the different forms of amorphous carbon films are biocompatible and suitable for specific biomedical applications. On the other hand, bacterial adhesion on implant surfaces has also a strong influence on the healing and long-term outcome of biomedical devices and this has not been thoroughly studied for the carbon films. The purpose of this

  6. Effects of Receptor Interaction in Bacterial Chemotaxis

    Microsoft Academic Search

    Bernardo A. Mello; Leah Shaw; Yuhai Tuz

    2004-01-01

    Signaling in bacterial chemotaxis is mediated by several types of transmembrane chemoreceptors. The chemoreceptors form tight polar clusters whose functions are of great biological interest. Here, we study the general properties of a chemotaxis model that includes interaction between neighboring chemoreceptors within a receptor cluster and the appropriate receptor methylation and demethylation dynamics to maintain (near) perfect adaptation. We find

  7. ORIGINAL ARTICLE Investigation of archaeal and bacterial

    E-print Network

    Bae, Jin-Woo

    of the earlier studies of fermented food have focused on lactic acid bacteria (LAB) in the fermentation process. In this study, the archaeal and bacterial diversity in seven kinds of fermented seafood were culture, such as shrimp, oysters, fish roes, and fish tripes with lots of salt, followed by a fermentation period so

  8. Cadmium bio-sorption by bacterial exopolysaccharide

    Microsoft Academic Search

    J. A. Scott; S. J. Palmer

    1988-01-01

    Summary Bacterial exopolysaccharides can significantly enhance bio-sorption of cadmium. Exopolysaccharide fromArthrobacterviscosus has a 2.3 times greater accumulation capacity than the equivalent weight of intact cells and is 13.7 times more effective than the cells ofArthrobacterglobiformis, an organism that does not produce exopolysaccharide.

  9. Measurement of bacterial gene expression in vivo.

    PubMed Central

    Hautefort, I; Hinton, J C

    2000-01-01

    The complexities of bacterial gene expression during mammalian infection cannot be addressed by in vitro experiments. We know that the infected host represents a complex and dynamic environment, which is modified during the infection process, presenting a variety of stimuli to which the pathogen must respond if it is to be successful. This response involves hundreds of ivi (in vivo-induced) genes which have recently been identified in animal and cell culture models using a variety of technologies including in vivo expression technology, differential fluorescence induction, subtractive hybridization and differential display. Proteomic analysis is beginning to be used to identify IVI proteins, and has benefited from the availability of genome sequences for increasing numbers of bacterial pathogens. The patterns of bacterial gene expression during infection remain to be investigated. Are ivi genes expressed in an organ-specific or cell-type-specific fashion? New approaches are required to answer these questions. The uses of the immunologically based in vivo antigen technology system, in situ PCR and DNA microarray analysis are considered. This review considers existing methods for examining bacterial gene expression in vivo, and describes emerging approaches that should further our understanding in the future. PMID:10874733

  10. Multifunctionality and Diversity in Bacterial Biofilms

    Microsoft Academic Search

    Hannes Peter; Irene Ylla; Cristian Gudasz; Anna M. Romaní; Sergi Sabater; Lars J. Tranvik

    2011-01-01

    Bacteria are highly diverse and drive a bulk of ecosystem processes. Analysis of relationships between diversity and single specific ecosystem processes neglects the possibility that different species perform multiple functions at the same time. The degradation of dissolved organic carbon (DOC) followed by respiration is a key bacterial function that is modulated by the availability of DOC and the capability

  11. Bacterial conditions of water in dental units.

    PubMed

    Thé, S D; Van't Hof, M A

    1975-01-01

    Stagnant water in the boiler of a dental unit can cause a high bacterial density. A spiral unit is somewhat superior to a boiler in this respect. Normal unchlorinated tapwater is the main problem in achieving hygienic conditions in dental practice. The technical performance of the unit is only partly responsible for the water quality. PMID:1058859

  12. Study of bacterial motility using optical tweezers

    Microsoft Academic Search

    Suddhashil Chattopadhyay

    2008-01-01

    Bacteria are arguably the simplest of known microorganisms, forming a fundamental part of the world we live in. Many functions they perform are found in scaled-up versions in higher organisms. Among many advanced functions, bacteria possess the ability to move in search for nutrients and favorable growth conditions. Measurement of the dynamical variables associated with bacterial swimming has proven to

  13. The bacterial quality of bottled vater

    Microsoft Academic Search

    P. V. Scarpino; G. R. Kellner; H. C. Cook

    1987-01-01

    The bacterial quality of a total of 204 water samples representing 22 brands of bottled waters (both domestic and imported) obtained from retail outlets in the Cincinnati, Ohio, area was examined using the heterotrophic plate count and the total coliform multiple?tube fermentation and membrane filtration techniques. It was found after 48 hr at 35°C that 27 percent of the samples

  14. Resistance to Bacterial Pathogens in Plants

    E-print Network

    Innes, Roger

    Resistance to Bacterial Pathogens in Plants Jules Ade, Indiana University, Bloomington, Indiana, pathogens must overcome three layers of defense: (1) preformed physical barriers; (2) a cell-surface-based surveillance system that detects conserved pathogen molecules and (3) an intracellular surveillance system

  15. Bacterial detoxification of organophosphate nerve agents

    Microsoft Academic Search

    Frank M Raushel

    2002-01-01

    Bacterial enzymes have been isolated that catalyze the hydrolysis of organophosphate nerve agents with high-rate enhancements and broad substrate specificity. Mutant forms of these enzymes have been constructed through rational redesign of the active-site binding pockets and random mutagenesis to create protein variants that are optimized for the detoxification of agricultural insecticides and chemical warfare agents. In this review, the

  16. Bacterial Division: The Fellowship of The Ring

    Microsoft Academic Search

    William Margolin

    2003-01-01

    The Z ring, composed of the tubulin homolog FtsZ, is essential for bacterial cell division. Recently a new protein, ZapA, has been discovered that localizes to the Z ring and stabilizes it, probably by promoting the bundling of FtsZ protofilaments.

  17. Bacteriophage Host Range and Bacterial Resistance

    Microsoft Academic Search

    Paul Hyman; Stephen T. Abedon

    2010-01-01

    Host range describes the breadth of organisms a parasite is capable of infecting, with limits on host range stemming from parasite, host, or environmental characteristics. Parasites can adapt to overcome host or environmental limitations, while hosts can adapt to control the negative impact of parasites. We consider these adaptations as they occur among bacteriophages (phages) and their bacterial hosts, since

  18. The regulation of bacterial transcription initiation

    Microsoft Academic Search

    Douglas F. Browning; Stephen J. W. Busby

    2004-01-01

    Bacteria use their genetic material with great effectiveness to make the right products in the correct amounts at the appropriate time. Studying bacterial transcription initiation in Escherichia coli has served as a model for understanding transcriptional control throughout all kingdoms of life. Every step in the pathway between gene and function is exploited to exercise this control, but for reasons

  19. Bacterial Cellulose: Long-Term Biocompatibility Studies

    Microsoft Academic Search

    Renata A. N. Pértile; Susana Moreira; Rui M. Gil da Costa; Alexandra Correia; Luisa Guărdao; Fátima Gartner; Manuel Vilanova; Miguel Gama

    2012-01-01

    The bacterial cellulose (BC) secreted by Gluconacetobacter xylinus is a network of pure cellulose nanofibres which has high crystallinity, wettability and mechanical strength. These characteristics make BC an excellent material for tissue-engineering constructs, noteworthy for artificial vascular grafts. In this work, the in vivo biocompatibility of BC membranes produced by two G. xylinus strains was analyzed through histological analysis of

  20. Bacterial decontamination using ambient pressure nonthermal discharges

    Microsoft Academic Search

    Joseph G. Birmingham; Donald J. Hammerstrom

    2000-01-01

    Atmospheric pressure nonthermal plasmas can efficiently deactivate bacteria in gases, liquids, and on surfaces, as well as can decompose hazardous chemicals. This paper focuses on the changes to bacterial spores and toxic biochemical compounds, such as mycotoxins, after their treatment in ambient pressure discharges. The ability of nonthermal plasmas to decompose toxic chemicals and deactivate hazardous biological materials has been

  1. Bacterial Evolution: Chromosome Arithmetic and Geometry

    E-print Network

    Ochman, Howard

    genes. Among the fully sequenced genomes included in Table 1, the partitioning of replicons have characterized bacterial genomes that are organized onto elements of various sizes, shapes genome sequences, noting that some authors tackle this nomenclature problem with explicit rules, whereas

  2. Bacterial Conditions of Water in Dental Units

    Microsoft Academic Search

    S. D. Thé; M. A. Vant Hof

    1975-01-01

    Stagnant water in the boiler of a dental unit can cause a high bacterial density. A spiral unit is somewhat superior to a boiler in this respect, Normal unchlorinated tapwater is the main problem in achieving hygienic conditions in dental practice. The technical performance of the unit is only partly responsible for the water quality.

  3. Bacterial associations with decaying wood: a review

    Microsoft Academic Search

    Carol A. Clausen

    1996-01-01

    Wood-inhabiting bacteria are associated with wood decay and may have an indirect influence on the decay process. Bacteria are able to affect wood permeability, attack wood structure, or work synergistically with other bacteria and soft-rot fungi to predispose wood to fungal attack. Bacteria that can inhabit chemically treated wood are recognized. The natural ability of certain bacterial genera to decompose

  4. Mathematical description of bacterial traveling pulses

    Microsoft Academic Search

    Nikolaos Bournaveas; Axel Buguin; Vincent Calvez; Benoît Perthame; Jonathan Saragosti; Pascal Silberzan

    2009-01-01

    The Keller-Segel system has been widely proposed as a model for bacterial waves driven by chemotactic processes. Current experiments on {\\\\em E. coli} have shown precise structure of traveling pulses. We present here an alternative mathematical description of traveling pulses at a macroscopic scale. This modeling task is complemented with numerical simulations in accordance with the experimental observations. Our model

  5. Biosensors for Whole-Cell Bacterial Detection

    PubMed Central

    Rushworth, Jo V.; Hirst, Natalie A.; Millner, Paul A.

    2014-01-01

    SUMMARY Bacterial pathogens are important targets for detection and identification in medicine, food safety, public health, and security. Bacterial infection is a common cause of morbidity and mortality worldwide. In spite of the availability of antibiotics, these infections are often misdiagnosed or there is an unacceptable delay in diagnosis. Current methods of bacterial detection rely upon laboratory-based techniques such as cell culture, microscopic analysis, and biochemical assays. These procedures are time-consuming and costly and require specialist equipment and trained users. Portable stand-alone biosensors can facilitate rapid detection and diagnosis at the point of care. Biosensors will be particularly useful where a clear diagnosis informs treatment, in critical illness (e.g., meningitis) or to prevent further disease spread (e.g., in case of food-borne pathogens or sexually transmitted diseases). Detection of bacteria is also becoming increasingly important in antibioterrorism measures (e.g., anthrax detection). In this review, we discuss recent progress in the use of biosensors for the detection of whole bacterial cells for sensitive and earlier identification of bacteria without the need for sample processing. There is a particular focus on electrochemical biosensors, especially impedance-based systems, as these present key advantages in terms of ease of miniaturization, lack of reagents, sensitivity, and low cost. PMID:24982325

  6. Bacterial recovery from ancient glacial ice

    Microsoft Academic Search

    Brent C. Christner; Ellen Mosley-Thompson; Lonnie G. Thompson; John N. Reeve

    2003-01-01

    Summary Ice that forms the bottom 18 m of a 308 m ice core drilled from the Guliya ice cap on the Qinghan-Tibetan plateau in Western China is over 750 000 years old and is the oldest glacial ice known to date. Fourteen bacterial isolates have been recovered from samples of this ice from ~ ~ ~ ~ 296 m

  7. Factors predisposing to bacterial invasion and infection

    Microsoft Academic Search

    Michael Heinzelmann; Melanie Scott; Tina Lam

    2002-01-01

    Background: Bacterial infections remain important causes of morbidity and mortality in surgical patients. Our understanding of the effects of bacteria on the host, and also the defense mechanisms available to the host, is improving all the time. Modern tools in biochemistry, immunology, and molecular biology have provided powerful methods to further our understanding of the complex interactions that contribute to

  8. Bacterial plant oncogenes: The rol genes' saga

    Microsoft Academic Search

    P. Costantino; I. Capone; M. Cardarelli; A. De Paolis; M. L. Mauro; M. Trovato

    1994-01-01

    Therol genes are part of the T-DNA which is transferred byAgrobacterium rhizogenes in plant cells, causing neoplastic growth and differentiation. Each of these bacterial oncogenes deeply influences plant development and is finely regulated once transferred into the plant host. Both from the study of the effects and biochemical function of therol genes and from the analysis of their regulation, important

  9. Novel Bacterial Taxa in the Human Microbiome

    Microsoft Academic Search

    Kristine M. Wylie; Rebecca M. Truty; Thomas J. Sharpton; Kathie A. Mihindukulasuriya; Yanjiao Zhou; Hongyu Gao; Erica Sodergren; George M. Weinstock; Katherine S. Pollard

    2012-01-01

    The human gut harbors thousands of bacterial taxa. A profusion of metagenomic sequence data has been generated from human stool samples in the last few years, raising the question of whether more taxa remain to be identified. We assessed metagenomic data generated by the Human Microbiome Project Consortium to determine if novel taxa remain to be discovered in stool samples

  10. Bacterial responses to photo-oxidative stress

    Microsoft Academic Search

    Eva C. Ziegelhoffer; Timothy J. Donohue

    2009-01-01

    Singlet oxygen is one of several reactive oxygen species that can destroy biomolecules, microorganisms and other cells. Traditionally, the response to singlet oxygen has been termed photo-oxidative stress, as light-dependent processes in photosynthetic cells are major biological sources of singlet oxygen. Recent work identifying a core set of singlet oxygen stress response genes across various bacterial species highlights the importance

  11. Chlorine Inactivation of Bacterial Bioterrorism Agents

    PubMed Central

    Rose, Laura J.; Rice, Eugene W.; Jensen, Bette; Murga, Ricardo; Peterson, Alicia; Donlan, Rodney M.; Arduino, Matthew J.

    2005-01-01

    Seven species of bacterial select agents were tested for susceptibility to free available chlorine (FAC). Under test conditions, the FAC routinely maintained in potable water would be sufficient to reduce six species by 2 orders of magnitude within 10 min. Water contaminated with spores of Bacillus anthracis spores would require further treatment. PMID:15640238

  12. A field study of ovine bacterial meningoencephalitis

    Microsoft Academic Search

    PR Scott; ND Sargison; CD Penny; RS Pirie

    1994-01-01

    Bacterial meningoencephalitis most commonly affected lambs two to four weeks old (median three weeks, range three days to six months) with clinical signs of episcleral congestion, lack of suck reflex, weakness, altered gait and depression extending to stupor, but hyperaesthesia to auditory and tactile stimuli. Opisthotonos was observed during the agonal stages of the disease. Analysis of lumbosacral cerebrospinal fluid

  13. Bacterial diversity within the human subgingival crevice

    PubMed Central

    Kroes, Ian; Lepp, Paul W.; Relman, David A.

    1999-01-01

    Molecular, sequence-based environmental surveys of microorganisms have revealed a large degree of previously uncharacterized diversity. However, nearly all studies of the human endogenous bacterial flora have relied on cultivation and biochemical characterization of the resident organisms. We used molecular methods to characterize the breadth of bacterial diversity within the human subgingival crevice by comparing 264 small subunit rDNA sequences from 21 clone libraries created with products amplified directly from subgingival plaque, with sequences obtained from bacteria that were cultivated from the same specimen, as well as with sequences available in public databases. The majority (52.5%) of the directly amplified 16S rRNA sequences were <99% identical to sequences within public databases. In contrast, only 21.4% of the sequences recovered from cultivated bacteria showed this degree of variability. The 16S rDNA sequences recovered by direct amplification were also more deeply divergent; 13.5% of the amplified sequences were more than 5% nonidentical to any known sequence, a level of dissimilarity that is often found between members of different genera. None of the cultivated sequences exhibited this degree of sequence dissimilarity. Finally, direct amplification of 16S rDNA yielded a more diverse view of the subgingival bacterial flora than did cultivation. Our data suggest that a significant proportion of the resident human bacterial flora remain poorly characterized, even within this well studied and familiar microbial environment. PMID:10588742

  14. Identification of bacterial cells by chromosomal painting.

    PubMed Central

    Lanoil, B D; Giovannoni, S J

    1997-01-01

    Chromosomal painting is a technique for the microscopic localization of genetic material. It has been applied at the subcellular level to identify regions of eukaryotic chromosomes. Here we describe the development of bacterial chromosomal painting (BCP), a related technology for the identification of bacterial cells. Purified genomic DNAs from six bacterial strains were labeled by nick translation with the fluorochrome Fluor-X, Cy3, or Cy5. The average size of the labeled fragments was ca. 50 to 200 bp. The probes were hybridized to formaldehyde-fixed microbial cells attached to slides and visualized by fluorescence microscopy. In reciprocal comparisons, distantly related members of the class Proteobacteria (Escherichia coli and Oceanospirillum linum), different species of the genus Bacillus (B. subtilis and B. megaterium), and different serotypes of the subspecies Salmonella choleraesuis subsp. choleraesuis (serotype typhimurium LT2 and serotype typhi Ty2) could easily be distinguished. A combination of two probes, each labeled with a different fluorochrome, was used successfully to simultaneously identify two cell types in a mixture. Lysozyme treatment was required for the identification of Bacillus spp., and RNase digestion and pepsin digestion were found to enhance signal strength and specificity for all cell types tested. Chromosome in situ suppression, a technique that removes cross-hybridizing fragments from the probe, was necessary for the differentiation of the Salmonella serotypes but was not required to distinguish the more distantly related taxa. BCP may have applications in diverse branches of microbiology where the objective is the identification of bacterial cells. PMID:9055426

  15. Recent Advances in Bacterial Coldwater Disease Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A primary objective of the National Center for Cool and Cold Water Aquaculture (NCCCWA) is to reduce the negative impact of diseases on rainbow trout culture. One of the diseases we work on is bacterial cold-water disease caused by Flavobacterium psychrophilum. This is a chronic disease of rainbow...

  16. Regulation of glucose metabolism in bacterial systems

    Microsoft Academic Search

    Horst Doelle; Ken Ewings; Neil Hollywood

    In the past 10 years there have been rapid developments in the elucidation of the mechanisms of the Pasteur (or oxygen) and the Crabtree (or glucose repression of the respiratory chain) Effects in bacterial systems, which convincingly exhibit the difference between the regulatory mechanisms in yeast and bacteria. The presented review will demonstrate that the enzyme phosphofructokinase plays no role

  17. Bacterial Hazards Associated with Swine Wastes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the implications of the persistence of swine-associated zoonotic pathogens during storage, treatment, and land application is important to assessing and controlling their presence in the environment. This review focuses on the persistence of the best characterized bacterial pathogens ...

  18. Bacterial respiration of arsenic and selenium

    Microsoft Academic Search

    John F. Stolz; Ronald S. Oremland

    1999-01-01

    Oxyanions of arsenic and selenium can be used in microbial anaerobic respiration as terminal electron acceptors. The detection of arsenate and selenate respiring bacteria in numerous pristine and contaminated environments and their rapid appearance in enrichment culture suggest that they are widespread and metabolically active in nature. Although the bacterial species that have been isolated and characterized are still few

  19. Bacterial infections, immune overload, and MMR vaccine

    Microsoft Academic Search

    E Miller; N Andrews; P Waight; B Taylor

    2003-01-01

    Combined measles, mumps, and rubella (MMR) vaccine did not increase the risk of hospitalisation with invasive bacterial infection in the three months after vaccination; rather there was a protective effect. These results provide no support for the concept of “immunological overload” induced by multiple antigen vaccinations, nor calls for single antigen vaccines.

  20. Demystifying the Nomenclature of Bacterial Plant Pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A unified approach to bacterial names ensures accurate communication among scientists, regulators and the public. Rules for nomenclature ensure that changes to names of taxa follow a logical progression that maintains the integrity of the previous nomenclature while replacing it with new proposals b...

  1. New Bacterial Species Associated with Chronic Periodontitis

    Microsoft Academic Search

    P. S. Kumar; A. L. Griffen; J. A. Barton; B. J. Paster; M. L. Moeschberger; E. J. Leys

    2003-01-01

    Recent investigations of the human subgingival oral flora based on ribosomal 16S cloning and sequencing have shown many of the bacterial species present to be novel species or phylotypes. The purpose of the present investigation was to identify potential periodontal pathogens among these newly identified species and phylotypes. Species-specific ribosomal 16S primers for PCR amplification were developed for detection of

  2. The 'Swiss cheese' instability of bacterial biofilms

    E-print Network

    Jang, Hongchul; Stocker, Roman

    2012-01-01

    We demonstrate a novel pattern that results in bacterial biofilms as a result of the competition between hydrodynamic forces and adhesion forces. After the passage of an air plug, the break up of the residual thin liquid film scrapes and rearranges bacteria on the surface, such that a Swiss cheese pattern of holes is left in the residual biofilm.

  3. ANIMAL MANURE: BACTERIAL PATHOGENS AND DISINFECTION TECHNOLOGIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report reviews and summarizes information about the main bacterial pathogens in manure that have been implicated in food- or waterborne illness outbreaks, their survival in untreated and treated manure, and methods used for their detection and enumeration. Current methods for detecting/enumerat...

  4. Enzymatic Removal and Disinfection of Bacterial Biofilms

    Microsoft Academic Search

    CHARLOTTE JOHANSEN; PER FALHOLT; LONE GRAM

    1997-01-01

    Model biofilms of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas fluorescens, and Pseudomo- nas aeruginosa were made on steel and polypropylene substrata. Plaque-resembling biofilms of Streptococcus mutans, Actinomyces viscosus, and Fusobacterium nucleatum were made on saliva-coated hydroxyapatite. The activity of enzymes against bacterial cells in biofilm was measured by fluorescence microscopy and an indirect conductance test in which evolution of carbon dioxide

  5. Bacterial Acclimation Inside an Aqueous Battery

    PubMed Central

    Dong, Dexian; Chen, Baoling; Chen, P.

    2015-01-01

    Specific environmental stresses may lead to induced genomic instability in bacteria, generating beneficial mutants and potentially accelerating the breeding of industrial microorganisms. The environmental stresses inside the aqueous battery may be derived from such conditions as ion shuttle, pH gradient, free radical reaction and electric field. In most industrial and medical applications, electric fields and direct currents are used to kill bacteria and yeast. However, the present study focused on increasing bacterial survival inside an operating battery. Using a bacterial acclimation strategy, both Escherichia coli and Bacillus subtilis were acclimated for 10 battery operation cycles and survived in the battery for over 3 days. The acclimated bacteria changed in cell shape, growth rate and colony color. Further analysis indicated that electrolyte concentration could be one of the major factors determining bacterial survival inside an aqueous battery. The acclimation process significantly improved the viability of both bacteria E. coli and B. subtilis. The viability of acclimated strains was not affected under battery cycle conditions of 0.18-0.80 mA cm-2 and 1.4-2.1 V. Bacterial addition within 1.0×1010 cells mL-1 did not significantly affect battery performance. Because the environmental stress inside the aqueous battery is specific, the use of this battery acclimation strategy may be of great potential for the breeding of industrial microorganisms. PMID:26070088

  6. Bacterial Paleontology and Studies of Carbonaceous Chondrites

    NASA Technical Reports Server (NTRS)

    Gerasimenko, L. M.; Hoover, Richard B.; Rozanov, Alexei Y.; Zhegallo, E. A.; Zhmur, S. I.

    1999-01-01

    The study of the fossilization processes of modern cyanobacteria provides insights needed to recognize bacterial microfossils. The fossilization of cyanobacteria is discussed and images of recent and fossil bacteria and cyanobacteria from the Early Proterozoic to Neogene carbonaceous rocks (kerites, shungites, and black shales) and phosphorites are provided. These are compared with biomorphic microstructures and possible microfossils encountered in-situ in carbonaceous meteorites.

  7. Bacterial growth on dissolved organic carbon from a blackwater river

    Microsoft Academic Search

    Judy L. Meyer; Richard T. Edwards; Rebecca Risley

    1987-01-01

    Different nominal molecular weight (nMW) fractions of DOC from a southeastern blackwater river were concentrated by ultrafiltration and added to sieved river water to assess each fraction's ability to stimulate bacterial growth. Bacterial growth was measured using change in bacterial biomass from direct counts and using3H-thymidine incorporated into DNA. Bacterial growth and amount of DOC used was greatest in the

  8. Family Demands, Social Support and Family Functioning in Taiwanese Families Rearing Children with Down Syndrome

    ERIC Educational Resources Information Center

    Hsiao, C-Y.

    2014-01-01

    Background: Down syndrome (DS) affects not only children but also their families. Much remains to be learned about factors that influence how families of children with DS function, especially families in non-Western populations. The purpose of this cross-sectional, correlational study was to examine how family demographics, family demands and…

  9. BACTERIAL PREFERENCES OF THE BACTERIVOROUS SOIL NEMATODE CEPHALOBUS BREVICAUDA (CEPHALOBIDATE): EFFECT OF BACTERIAL TYPE AND SIZE

    EPA Science Inventory

    Cell size and type may affect availability of bacteria for consumption by bacterivorous nematodes in the soil and in culture. This study explored the bacterial preferences of the bacterivorous soil nematode Cephalobus brevicauda (Cephalobidae) by comparing bactgeria isolated dir...

  10. Creating a Family Health History

    MedlinePLUS

    ... Why Create a Family Health History? In This Topic Why Create a Family Health History? Family History ... for More Information National Institute on Aging Related Topics Talking With Your Doctor The information in this ...

  11. Welfare Policies and Black Families.

    ERIC Educational Resources Information Center

    Trader, Harriet Peat

    1979-01-01

    The family is an important resource for minority persons, and many minority families depend on public welfare for their survival. This article offers a compact analysis of how welfare policies often work to the disadvantage of poor Black families. (Author)

  12. ABC Foundation Adler Family Foundation

    E-print Network

    Napier, Terrence

    of Allentown Baer-Kaelin Foundation Dexter F. and Dorothy H. Baker Foundation The David M. and Barbara Baldwin. Keller Family Foundation Robert P. Kelly Family Foundation Letha J. Kemper Family Trust Philip I. Kent

  13. Families and Fragile X Syndrome

    MedlinePLUS

    ... Publications Scientific Research Planning Scientific Resources Research Families & Fragile X Syndrome: Index Skip sharing on social media links Share ... Health and Human Development (NICHD) family album about Fragile X syndrome. As a health research agency, the NICHD family ...

  14. Family Health and Medical Record.

    E-print Network

    Shirer, Mary Ann

    1982-01-01

    ,,, "' Family member Date Type of injury Doctor r {\\ ............. Family member Cause of sensitivity/allergic reaction Office/clinic/ hospital ,--.... Instructions/ medication 13 I 14 15 Medical and oEJntal Checkups I Family member Date Type...

  15. Comparison of Bacterial Communities in New England Sphagnum Bogs Using Terminal Restriction Fragment

    E-print Network

    Gotelli, Nicholas J.

    Microbial Ecology Comparison of Bacterial Communities in New England Sphagnum Bogs Using Terminal the taxonomic diversity of bacterial communities in wetlands, particularly Sphagnum bogs. To explore bacterial community composition, 24 bogs in Vermont and Massachusetts were censused for bacterial diversity

  16. Multiple genetic switches spontaneously modulating bacterial mutability

    PubMed Central

    2010-01-01

    Background All life forms need both high genetic stability to survive as species and a degree of mutability to evolve for adaptation, but little is known about how the organisms balance the two seemingly conflicting aspects of life: genetic stability and mutability. The DNA mismatch repair (MMR) system is essential for maintaining genetic stability and defects in MMR lead to high mutability. Evolution is driven by genetic novelty, such as point mutation and lateral gene transfer, both of which require genetic mutability. However, normally a functional MMR system would strongly inhibit such genomic changes. Our previous work indicated that MMR gene allele conversion between functional and non-functional states through copy number changes of small tandem repeats could occur spontaneously via slipped-strand mis-pairing during DNA replication and therefore may play a role of genetic switches to modulate the bacterial mutability at the population level. The open question was: when the conversion from functional to defective MMR is prohibited, will bacteria still be able to evolve by accepting laterally transferred DNA or accumulating mutations? Results To prohibit allele conversion, we "locked" the MMR genes through nucleotide replacements. We then scored changes in bacterial mutability and found that Salmonella strains with MMR locked at the functional state had significantly decreased mutability. To determine the generalizability of this kind of mutability 'switching' among a wider range of bacteria, we examined the distribution of tandem repeats within MMR genes in over 100 bacterial species and found that multiple genetic switches might exist in these bacteria and may spontaneously modulate bacterial mutability during evolution. Conclusions MMR allele conversion through repeats-mediated slipped-strand mis-pairing may function as a spontaneous mechanism to switch between high genetic stability and mutability during bacterial evolution. PMID:20836863

  17. Bacterial diversity in marine hydrocarbon seep sediments.

    PubMed

    LaMontagne, Michael G; Leifer, Ira; Bergmann, Sandra; Van De Werfhorst, Laurie C; Holden, Patricia A

    2004-08-01

    Marine seeps introduce significant amounts of hydrocarbons into oceans and create unusual habitats for microfauna and -flora. In the vicinity of chronic seeps, microbes likely exert control on carbon quality entering the marine food chain and, in turn, hydrocarbons could influence microbial community composition and diversity. To determine the effects of seep oil on marine sediment bacterial communities, we collected sediment piston cores within an active marine hydrocarbon seep zone in the Coal Oil Point Seep Field, at a depth of 22 m in the Santa Barbara Channel, California. Cores were taken adjacent to an active seep vent in a hydrocarbon volcano, on the edge of the volcano, and at the periphery of the area of active seepage. Bacterial community profiles were determined by terminal restriction fragment length polymorphisms (TRFLPs) of 16S ribosomal genes that were polymerase chain reaction (PCR)-amplified with eubacterial primers. Sediment carbon content and C/N ratio increased with oil content. Terminal restriction fragment length polymorphisms suggested that bacterial communities varied both with depth into sediments and with oil concentration. Whereas the apparent abundance of several peaks correlated positively with hydrocarbon content, overall bacterial diversity and richness decreased with increasing sediment hydrocarbon content. Sequence analysis of a clone library generated from sediments collected at the periphery of the seep suggested that oil-sensitive species belong to the gamma Proteobacteria and Holophaga groups. These sequences were closely related to sequences previously recovered from uncontaminated marine sediments. Our results suggest that seep hydrocarbons exert a strong selective pressure on bacterial communities in marine sediments. This selective pressure could, in turn, control the effects of oil on other biota in the vicinity of marine hydrocarbon seeps. PMID:15250882

  18. Bacterial superinfection in Zoonotic Cutaneous Leishmaniasis

    PubMed Central

    Doudi, Monir; Setorki, Mahbubeh; Narimani, Manizheh

    2012-01-01

    Summary Background Zoonotic Cutaneous Leishmaniasis (ZCL) is a polymorphic disease. It is generally accepted that bacterial superinfection may play a role in the clinical appearance of the lesions and may delay or prevent the healing process. However, the pattern of bacterial pathogens involved has rarely been investigated. Material/Methods The aim of this study was to identify the bacterial species contaminating the suspected ZCL and their susceptibility to commonly used antibiotics. Microscopic examination of stained smears and cultures were used to differentiate ZCL from non-ZCL lesions in a rural area north of Isfahan, Iran from July to December 2009. Bacteria were isolated from the lesions and identified and antibiotic susceptibility was determined by standard microbiological techniques. Results The results show that 602 (68%) of 855 patients were positive for ZCL, of which 83.4% with volcano-shape, 8.8% psoriasiform, 6.6% popular form and 1.2% with other atypical forms of ZCL. The bacteria were isolated from 66.8% of ZCL (70% of volcano-shape, 60% of psoriasiform and 25% of popular form) and 64.7% of non-ZCL lesions. The most common species were Staphylococcus aureus (41.7%) and S. epidermidis (28%) followed by Bacillus sp. Streptococcus pyogenes, Escherichia coli, Klebsiella sp., Proteus sp., Enterobacter sp. and Pseudomonas aeroginosa. Ciprofloxacin, Erythromycin, Cefazolin and Clindamycin were the most effective antibiotics. Conclusions Bacterial superinfection appears to be very common in ZCL, but its prevalence is not different from that of non-ZCL lesions and it has little effect on the clinical appearance of anthroponotic cutaneous Leishmaniasis (ACL). Local lesion care and management of bacterial superinfection must be considered in the treatment of ZCL. PMID:22936185

  19. Structural correlations in bacterial metabolic networks

    PubMed Central

    2011-01-01

    Background Evolution of metabolism occurs through the acquisition and loss of genes whose products acts as enzymes in metabolic reactions, and from a presumably simple primordial metabolism the organisms living today have evolved complex and highly variable metabolisms. We have studied this phenomenon by comparing the metabolic networks of 134 bacterial species with known phylogenetic relationships, and by studying a neutral model of metabolic network evolution. Results We consider the 'union-network' of 134 bacterial metabolisms, and also the union of two smaller subsets of closely related species. Each reaction-node is tagged with the number of organisms it belongs to, which we denote organism degree (OD), a key concept in our study. Network analysis shows that common reactions are found at the centre of the network and that the average OD decreases as we move to the periphery. Nodes of the same OD are also more likely to be connected to each other compared to a random OD relabelling based on their occurrence in the real data. This trend persists up to a distance of around five reactions. A simple growth model of metabolic networks is used to investigate the biochemical constraints put on metabolic-network evolution. Despite this seemingly drastic simplification, a 'union-network' of a collection of unrelated model networks, free of any selective pressure, still exhibit similar structural features as their bacterial counterpart. Conclusions The OD distribution quantifies topological properties of the evolutionary history of bacterial metabolic networks, and lends additional support to the importance of horizontal gene transfer during bacterial metabolic evolution where new reactions are attached at the periphery of the network. The neutral model of metabolic network growth can reproduce the main features of real networks, but we observe that the real networks contain a smaller common core, while they are more similar at the periphery of the network. This suggests that natural selection and biochemical correlations can act both to diversify and to narrow down metabolic evolution. PMID:21251250

  20. Sialidases (neuraminidases) in bacterial vaginosis and bacterial vaginosis-associated microflora.

    PubMed Central

    Briselden, A M; Moncla, B J; Stevens, C E; Hillier, S L

    1992-01-01

    Bacterial vaginosis, Prevotella species, and Bacteroides species have been associated with prematurity and upper genital tract infection. Prevotella (Bacteroides) species and Bacteroides fragilis have also been associated with preterm birth. However, the mechanism by which lower genital tract infection causes upper genital tract disease remains poorly understood. Sialidases (neuraminidases) are enzymes which enhance the ability of microorganisms to invade and destroy tissue. Elevated levels of sialidase activity were detected in 42 (84%) of 50 vaginal fluid specimens from women with bacterial vaginosis and none of 19 vaginal fluids from women without bacterial vaginosis (P less than 0.001). Vaginal fluid from women with bacterial vaginosis had a median specific activity of 9.8 U compared to 2.5 U of sialidase in women without bacterial vaginosis (P less than 0.001). In order to determine the probable source of sialidases in vaginal fluid, the microorganisms recovered from women with bacterial vaginosis before and after treatment were assayed. Of 28 specimens from women with bacterial vaginosis, 27 (96%) yielded sialidase-positive bacteria, at a median concentration of 10(6.5) CFU/ml of vaginal fluid. Prevotella and Bacteroides species accounted for the sialidase activity in 26 of the vaginal fluids, and Gardnerella vaginalis accounted for the sialidase activity in the remaining fluid. After treatment, sialidase was detected in the vaginal fluid of 1 (5%) of 22 women who responded to therapy and in all of 6 women for whom therapy failed. These data suggest that vaginal fluid sialidase is highly correlated with bacterial vaginosis and that the probable sources for this enzyme activity are the Bacteroides and Prevotella species present in the vagina. PMID:1551983

  1. Sialidases (neuraminidases) in bacterial vaginosis and bacterial vaginosis-associated microflora.

    PubMed

    Briselden, A M; Moncla, B J; Stevens, C E; Hillier, S L

    1992-03-01

    Bacterial vaginosis, Prevotella species, and Bacteroides species have been associated with prematurity and upper genital tract infection. Prevotella (Bacteroides) species and Bacteroides fragilis have also been associated with preterm birth. However, the mechanism by which lower genital tract infection causes upper genital tract disease remains poorly understood. Sialidases (neuraminidases) are enzymes which enhance the ability of microorganisms to invade and destroy tissue. Elevated levels of sialidase activity were detected in 42 (84%) of 50 vaginal fluid specimens from women with bacterial vaginosis and none of 19 vaginal fluids from women without bacterial vaginosis (P less than 0.001). Vaginal fluid from women with bacterial vaginosis had a median specific activity of 9.8 U compared to 2.5 U of sialidase in women without bacterial vaginosis (P less than 0.001). In order to determine the probable source of sialidases in vaginal fluid, the microorganisms recovered from women with bacterial vaginosis before and after treatment were assayed. Of 28 specimens from women with bacterial vaginosis, 27 (96%) yielded sialidase-positive bacteria, at a median concentration of 10(6.5) CFU/ml of vaginal fluid. Prevotella and Bacteroides species accounted for the sialidase activity in 26 of the vaginal fluids, and Gardnerella vaginalis accounted for the sialidase activity in the remaining fluid. After treatment, sialidase was detected in the vaginal fluid of 1 (5%) of 22 women who responded to therapy and in all of 6 women for whom therapy failed. These data suggest that vaginal fluid sialidase is highly correlated with bacterial vaginosis and that the probable sources for this enzyme activity are the Bacteroides and Prevotella species present in the vagina. PMID:1551983

  2. Microstructure and mechanical properties of bacterial cellulose\\/chitosan porous scaffold

    Microsoft Academic Search

    Thi Thi Nge; Masaya Nogi; Hiroyuki Yano; Junji Sugiyama

    2010-01-01

    A family of polysaccharide based scaffold materials, bacterial cellulose\\/chitosan (BC\\/CTS) porous scaffolds with various weight\\u000a ratios (from 20\\/80 to 60\\/40 w\\/w%) were prepared by freezing (?30 and ?80 °C) and lyophilization of a mixture of microfibrillated\\u000a BC suspension and chitosan solution. The microfibrillated BC (MFC) was subjected to 2,2,6,6-tetramethylpyperidine-1-oxyl radical\\u000a (TEMPO)-mediated oxidation to introduce surface carboxyl groups before mixing. The integration of

  3. Bacterial, archaeal and viral-like rhodopsins from the Red Sea.

    PubMed

    Philosof, Alon; Béjŕ, Oded

    2013-06-01

    The Gulf of Aqaba, extending north to the Red Sea, is an oligotrophic basin with typical open ocean gyre characteristics. Here we report on the existence of diverse microbial rhodopsins in the Gulf of Aqaba, based on 454-pyrosequencing-generated metagenome and metatranscriptome data sets, obtained from the microbial fraction smaller than 1.6 ?m. Bacterial SAR11, SAR86 and archaeal proteorhodopsins as well as viral-like rhodopsins were detected on the DNA level. On the RNA level, only SAR11 and SAR86 proteorhodopsin transcripts were detected. Our results add to the growing evidence that microbial rhodopsins are a diverse, abundant and widespread protein family. PMID:23754728

  4. Pharmacological treatment of bacterial infections of the respiratory tract

    Microsoft Academic Search

    Roger C Small

    2005-01-01

    Treatment of bacterial infections of the respiratory tract should allow for factors such as the patient’s history, the treatment situation and the result of any bacteriological diagnosis. Epiglottitis attributable to Haemophilus influenzae is treated with cefotaxime (a cephalosporin inhibitor of bacterial cell wall synthesis) or with chloramphenicol (an inhibitor of bacterial protein synthesis). Exacerbations of chronic bronchitis are treated with

  5. Genetic dissection of bacterial speck disease resistance in tomato

    Microsoft Academic Search

    John Salmeron; Caius Rommens; Susan Barker; Francine Carland; Giles Oldroyd; Anand Mehta; Douglas Dahlbeck; Brian Staskawicz

    1994-01-01

    The bacterial speck disease of tomato has been developed as a model system to elucidate the molecular basis of specificity in plant-bacterial interactions and to study signal transduction events involved in the expression of plant disease resistance. We have employed a mutagenic approach to define the steps involved in the expression of disease resistance to the bacterial pathogen, Pseudomonas syringae

  6. Microbiology: Detection of Bacterial Pathogens and Their Occurrence.

    ERIC Educational Resources Information Center

    Reasoner, Donald J.

    1978-01-01

    Presents a literature review of bacterial pathogens that are related to water pollution, covering publications from 1976-77. This review includes: (1) bacterial pathogens in animals; and (2) detection and identification of waterborne bacterial pathogens. A list of 129 references is also presented. (HM)

  7. Big Soda Lake (Nevada). 1. Pelagic bacterial heterotrophy and biomass

    Microsoft Academic Search

    JON P. ZEHR; RONALD W. HARVEY; RONALD S. OREMLAND; JAMES E. CLOERN; LEAH H. GEORGE

    1987-01-01

    Bacterial activities and abundance were measured seasonally in the water column of meromictic Big Soda Lake which is divided into three chemically distinct zones: aerobic mixolimnion, anaerobic mixolimnion, and anaerobic monimolimnion. Bacterial abundance ranged between 5 and 52 x 10h cells ml-', with highest biomass at the interfaces between these zones: 2-4 mg C liter' in the photosynthetic bacterial layer

  8. 2005 Nature Publishing Group Aminoglycoside antibiotics induce bacterial biofilm

    E-print Network

    Cai, Long

    © 2005 Nature Publishing Group Aminoglycoside antibiotics induce bacterial biofilm formation Lucas I. Miller2,3,4 Biofilms are adherent aggregates of bacterial cells that form on biotic and abiotic surfaces, including human tissues. Biofilms resist antibiotic treatment and contribute to bacterial

  9. Evolutionary transitions in bacterial symbiosis Joel L. Sachs1

    E-print Network

    Sachs, Joel

    Evolutionary transitions in bacterial symbiosis Joel L. Sachs1 , Ryan G. Skophammer, and John U mutualism. Each of these transitions has occurred many times in the history of bacterial­eukaryote symbiosis evolutionary transitions in bacterial symbiosis and test hypotheses about the selective, ecological

  10. Strengthening Our Military Families

    MedlinePLUS

    ... PSD-9. With the involvement of the National Economic Council, Office of the First Lady, and the ... goal of the program is to mitigate the economic hardship of deployed members and their families. The ...

  11. Media Time Family Pledge

    MedlinePLUS

    ... Listen Espańol Text Size Email Print Share Media Time Family Pledge Article Body At the beginning and end ... them. Kids learn best with small lessons over time as opposed to one big lecture or sit- ...

  12. Helping Friends and Family

    MedlinePLUS

    ... counselor specializing in treating families dealing with a chronic illness. Notify school social workers and teachers about your ... professional who has experience working with people facing chronic disease can help one or both of you deal ...

  13. Veterans and their families 

    E-print Network

    McKie, Linda; Morrison, Zoe; Thomson, Fionagh; Alstead, Allan

    This briefing paper reports on the outcomes of a range of activities undertaken with a number of veterans, veterans’ families, and third and public sector organisations located in Scotland. Our aim was to explore the resettlement experiences...

  14. Families with Kids

    MedlinePLUS

    ... Traumatic Brain Injury Life Stress Health & Wellness Anger Stigma Suicide Prevention Families with Kids Alcohol and Drugs ... Resilience Satisfaction with Life Sexual Truama Sleep Spirituality Stigma Stress Work Adjustment Worry Videos Post-Traumatic Stress ...

  15. My Fact Family

    NSDL National Science Digital Library

    Elizabeth Gehron

    2012-08-15

    Students will use cut out people shapes and number cards to create two addition problems and two subtraction problems using the same three numbers of a fact family to explore the commutative property.

  16. Importance of Family Routines

    MedlinePLUS

    ... You might go shopping as a family, visit museums and zoos, do chores that everyone participates in, go on hikes or bike rides, or attend religious services. On weekends children in the middle years can usually be allowed ...

  17. Familial Mediterranean fever

    MedlinePLUS

    ... Recurrent polyserositis; Benign paroxysmal peritonitis; Periodic disease; Periodic fever; FMF ... Familial Mediterranean fever is most often caused by a mutation in the MEFV gene. This gene creates proteins involved in inflammation. ...

  18. Family Adjustment to Aphasia

    MedlinePLUS

    ... this time. Seek additional counseling services as necessary. Communication Skills Family members also can help the person ... aphasia develop new skills to compensate for the communication problems. Some suggestion include: Continue to talk to ...

  19. [Orem's family evaluation].

    PubMed

    Dumas, L; de Montigny, F

    1993-11-01

    Nurses are beginning to realize that clients' deficits influence family members and, conversely, that family members play an important role in the development and resolution of these deficits. The authors attempted to find published literature describing a family nursing evaluation based upon Orem's conceptual framework. Previous nursing research has described how Orem's model is applied to nursing interventions with individual clients, but none has addressed the application of nursing interventions to multiperson units within a family situation. The authors developed their own concept from their personal and family experiences and a theoretical background of Orem's model. They chose to integrate systemic and communication theory, and developmental and functional approaches with Orem's concept of nursing care of multiperson units. According to the authors, this approach is consistent with Orem's model and represents a holistic vision of the family. Orem emphasizes that the nurse intervening with multiperson units should understand the structure and function of groups and be able to identify the actual ongoing process. Although Orem's theoretical framework is not based upon a systemic approach, the authors believe that it is possible to blend the systemic theory concepts with Orem's model. This article reviews the three basic concepts found within Orem's conceptual framework: self-care; self-care deficit, and nursing systems. The authors also outline their theoretical assumptions for the use of this approach with family nursing interventions, based upon six functional dimensions of the family as described by Epstein et al. and Guttman. In addition, the article provides a concrete example of how nursing evaluation can be structured within this scheme of reference. PMID:8261376

  20. [Systemic family therapy].

    PubMed

    Desmarouet, Jean; Goldziuk, Michel

    2014-01-01

    Systemic family therapy traces its roots to several disciplines and invites us to change our focus on the world. In the framework of therapy, it is based on a particular approach which aims not only to help the patient who is suffering, but also to support the other members of the family in order to find a new balance and a more flexible way of functioning. PMID:25095585