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1

Unique core genomes of the bacterial family vibrionaceae: insights into niche adaptation and speciation  

PubMed Central

Background The criteria for defining bacterial species and even the concept of bacterial species itself are under debate, and the discussion is apparently intensifying as more genome sequence data is becoming available. However, it is still unclear how the new advances in genomics should be used most efficiently to address this question. In this study we identify genes that are common to any group of genomes in our dataset, to determine whether genes specific to a particular taxon exist and to investigate their potential role in adaptation of bacteria to their specific niche. These genes were named unique core genes. Additionally, we investigate the existence and importance of unique core genes that are found in isolates of phylogenetically non-coherent groups. These groups of isolates, that share a genetic feature without sharing a closest common ancestor, are termed genophyletic groups. Results The bacterial family Vibrionaceae was used as the model, and we compiled and compared genome sequences of 64 different isolates. Using the software orthoMCL we determined clusters of homologous genes among the investigated genome sequences. We used multilocus sequence analysis to build a host phylogeny and mapped the numbers of unique core genes of all distinct groups of isolates onto the tree. The results show that unique core genes are more likely to be found in monophyletic groups of isolates. Genophyletic groups of isolates, in contrast, are less common especially for large groups of isolate. The subsequent annotation of unique core genes that are present in genophyletic groups indicate a high degree of horizontally transferred genes. Finally, the annotation of the unique core genes of Vibrio cholerae revealed genes involved in aerotaxis and biosynthesis of the iron-chelator vibriobactin. Conclusion The presented work indicates that genes specific for any taxon inside the bacterial family Vibrionaceae exist. These unique core genes encode conserved metabolic functions that can shed light on the adaptation of a species to its ecological niche. Additionally, our study suggests that unique core genes can be used to aid classification of bacteria and contribute to a bacterial species definition on a genomic level. Furthermore, these genes may be of importance in clinical diagnostics and drug development.

2012-01-01

2

A global gene evolution analysis on Vibrionaceae family using phylogenetic profile  

PubMed Central

Background Vibrionaceae represent a significant portion of the cultivable heterotrophic sea bacteria; they strongly affect nutrient cycling and some species are devastating pathogens. In this work we propose an improved phylogenetic profile analysis on 14 Vibrionaceae genomes, to study the evolution of this family on the basis of gene content. The phylogenetic profile is based on the observation that genes involved in the same process (e.g. metabolic pathway or structural complex) tend to be concurrently present or absent within different genomes. This allows the prediction of hypothetical functions on the basis of a shared phylogenetic profiles. Moreover this approach is useful to identify putative laterally transferred elements on the basis of their presence on distantly phylogenetically related bacteria. Results Vibrionaceae ORFs were aligned against all the available bacterial proteomes. Phylogenetic profile is defined as an array of distances, based on aminoacid substitution matrixes, from single genes to all their orthologues. Final phylogenetic profiles, derived from non-redundant list of all ORFs, was defined as the median of all the profiles belonging to the cluster. The resulting phylogenetic profiles matrix contains gene clusters on the rows and organisms on the columns. Cluster analysis identified groups of "core genes" with a widespread high similarity across all the organisms and several clusters that contain genes homologous only to a limited set of organisms. On each of these clusters, COG class enrichment has been calculated. The analysis reveals that clusters of core genes have the highest number of enriched classes, while the others are enriched just for few of them like DNA replication, recombination and repair. Conclusion We found that mobile elements have heterogeneous profiles not only across the entire set of organisms, but also within Vibrionaceae; this confirms their great influence on bacteria evolution even inside the same family. Furthermore, several hypothetical proteins highly correlate with mobile elements profiles suggesting a possible horizontal transfer mechanism for the evolution of these genes. Finally, we suggested the putative role of some ORFs having an unknown function on the basis of their phylogenetic profile similarity to well characterized genes.

Vitulo, Nicola; Vezzi, Alessandro; Romualdi, Chiara; Campanaro, Stefano; Valle, Giorgio

2007-01-01

3

DEVELOPMENT OF A SIMPLE AND RAPID FLUOROGENIC PROCEDURE FOR THE IDENTIFICATION OF VIBRIONACEAE FAMILY MEMBERS  

Technology Transfer Automated Retrieval System (TEKTRAN)

We describe a rapid, fluorogenic procedure to detect Vibrionaceae family members isolated from seawater, shellfish, sewage, and clinical samples. The assay, referred to as the colony overlay procedure for peptidases (COPP), is based on a recently identified lysyl aminopeptidase activity that is asso...

4

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

PubMed Central

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

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

1993-01-01

5

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

PubMed Central

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.

Simidu, Usio; Tsukamoto, Kumiko

1985-01-01

6

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

Microsoft Academic Search

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

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

2010-01-01

7

Genomic and systems evolution in Vibrionaceae species  

PubMed Central

Background The steadily increasing number of prokaryotic genomes has accelerated the study of genome evolution; in particular, the availability of sets of genomes from closely related bacteria has facilitated the exploration of the mechanisms underlying genome plasticity. The family Vibrionaceae is found in the Gammaproteobacteria and is abundant in aquatic environments. Taxa from the family Vibrionaceae are diversified in their life styles; some species are free living, others are symbiotic, and others are human pathogens. This diversity makes this family a useful set of model organisms for studying bacterial evolution. This evolution is driven by several forces, among them gene duplication and lateral gene transfer, which are believed to provide raw material for functional redundancy and novelty. The resultant gene copy increase in one genome is then detected as lineage-specific expansion (LSE). Results Here we present the results of a detailed comparison of the genomes of eleven Vibrionaceae strains that have distinct life styles and distinct phenotypes. The core genome shared by all eleven strains is composed of 1,882 genes, which make up about 31%–50% of the genome repertoire. We further investigated the distribution and features of genes that have been specifically expanded in one unique lineage of the eleven strains. Abundant duplicate genes have been identified in the eleven Vibrionaceae strains, with 1–11% of the whole genomes composed lineage specific radiations. These LSEs occurred in two distinct patterns: the first type yields one or more copies of a single gene; we call this a single gene expansion. The second pattern has a high evolutionary impact, as the expansion involves two or more gene copies in a block, with the duplicated block located next to the original block (a contiguous block expansion) or at some distance from the original block (a discontiguous block expansion). We showed that LSEs involve genes that are tied to defense and pathogenesis mechanisms as well as in the fundamental life cycle of Vibrionaceae species. Conclusion Our results provide evidence of genome plasticity and rapid evolution within the family Vibrionaceae. The comparisons point to sources of genomic variation and candidates for lineage-specific adaptations of each Vibrionaceae pathogen or nonpathogen strain. Such lineage specific expansions could reveal components in bacterial systems that, by their enhanced genetic variability, can be tied to responses to environmental challenges, interesting phenotypes, or adaptive pathogenic responses to host challenges.

Gu, Jianying; Neary, Jennifer; Cai, Hong; Moshfeghian, Audrey; Rodriguez, Stephen A; Lilburn, Timothy G; Wang, Yufeng

2009-01-01

8

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

PubMed Central

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.

2010-01-01

9

Genomic and systems evolution in Vibrionaceae species  

Microsoft Academic Search

BACKGROUND: The steadily increasing number of prokaryotic genomes has accelerated the study of genome evolution; in particular, the availability of sets of genomes from closely related bacteria has facilitated the exploration of the mechanisms underlying genome plasticity. The family Vibrionaceae is found in the Gammaproteobacteria and is abundant in aquatic environments. Taxa from the family Vibrionaceae are diversified in their

Jianying Gu; Jennifer Neary; Hong Cai; Audrey Moshfeghian; Stephen A Rodriguez; Timothy G Lilburn; Yufeng Wang

2009-01-01

10

Spatial and Temporal Distribution of the Vibrionaceae in Coastal Waters of Hawaii, Australia, and France  

Microsoft Academic Search

Relatively little is known about large-scale spatial and temporal fluctuations in bacterioplankton, especially within the\\u000a bacterial families. In general, however, a number of abiotic factors (namely, nutrients and temperature) appear to influence\\u000a distribution. Community dynamics within the Vibrionaceae are of particular interest to biologists because this family contains\\u000a a number of important pathogenic, commensal, and mutualist species. Of special interest

B. W. Jones; A. Maruyama; C. C. Ouverney; M. K. Nishiguchi

2007-01-01

11

Phylogenetic Analysis of the Incidence of lux Gene Horizontal Transfer in Vibrionaceae  

Microsoft Academic Search

Received 21 January 2008\\/Accepted 11 March 2008 Horizontal gene transfer (HGT) is thought to occur frequently in bacteria in nature and to play an important role in bacterial evolution, contributing to the formation of new species. To gain insight into the frequency of HGT in Vibrionaceae and its possible impact on speciation, we assessed the incidence of interspecies transfer of

Henryk Urbanczyk; Jennifer C. Ast; Allison J. Kaeding; James D. Oliver; Paul V. Dunlap

2008-01-01

12

Ecology and Population Structure of Vibrionaceae in the Coastal Ocean.  

National Technical Information Service (NTIS)

Extensive genetic diversity has been discovered in the microbial world, yet mechanisms that shape and maintain this diversity remain poorly understood. This thesis investigates to what extent populations of Vibrionaceae are ecologically specialized by inv...

S. P. Preheim

2010-01-01

13

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

PubMed Central

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

O'Hara, Caroline M.

2006-01-01

14

Conservation of the Chitin Utilization Pathway in the Vibrionaceae? †  

PubMed Central

Vibrionaceae are regarded as important marine chitin degraders, and attachment to chitin regulates important biological functions; yet, the degree of chitin pathway conservation in Vibrionaceae is unknown. Here, a core chitin degradation pathway is proposed based on comparison of 19 Vibrio and Photobacterium genomes with a detailed metabolic map assembled for V. cholerae from published biochemical, genomic, and transcriptomic results. Further, to assess whether chitin degradation is a conserved property of Vibrionaceae, a set of 54 strains from 32 taxa were tested for the ability to grow on various forms of chitin. All strains grew on N-acetylglucosamine (GlcNAc), the monomer of chitin. The majority of isolates grew on ? (crab shell) and ? (squid pen) chitin and contained chitinase A (chiA) genes. chiA sequencing and phylogenetic analysis suggest that this gene is a good indicator of chitin metabolism but appears subject to horizontal gene transfer and duplication. Overall, chitin metabolism appears to be a core function of Vibrionaceae, but individual pathway components exhibit dynamic evolutionary histories.

Hunt, Dana E.; Gevers, Dirk; Vahora, Nisha M.; Polz, Martin F.

2008-01-01

15

Prevalence of Bacterial Vaginosis in Women Attending Family Planning Clinics  

Microsoft Academic Search

Prevalence of bacterial vaginosis in 242 women attending family planning clinics in Concepción, Chile was studied using the Nugent criteria. The syndrome was present in 33.1% of women. No statistical difference was found between the occurrence of bacterial vaginosis and the of oral contraceptives (31.9%) or intrauterine devices (33.1%). The sensitivity and specificity of the Nugent criteria compared with the

Erica Castro; Mariana Dominguez; Paola Navarrete; Gioconda Boggiano; Raúl Zemelman

1999-01-01

16

Topological and phylogenetic analyses of bacterial holin families and superfamilies.  

PubMed

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

Reddy, Bhaskara L; Saier, Milton H

2013-07-13

17

Characterization of the bacterial diversity in Indo-West Pacific loliginid and sepiolid squid light organs.  

PubMed

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

Guerrero-Ferreira, Ricardo; Gorman, Clayton; Chavez, Alba A; Willie, Shantell; Nishiguchi, Michele K

2012-08-12

18

Phylogenetic analysis of the incidence of lux gene horizontal transfer in Vibrionaceae.  

PubMed

Horizontal gene transfer (HGT) is thought to occur frequently in bacteria in nature and to play an important role in bacterial evolution, contributing to the formation of new species. To gain insight into the frequency of HGT in Vibrionaceae and its possible impact on speciation, we assessed the incidence of interspecies transfer of the lux genes (luxCDABEG), which encode proteins involved in luminescence, a distinctive phenotype. Three hundred three luminous strains, most of which were recently isolated from nature and which represent 11 Aliivibrio, Photobacterium, and Vibrio species, were screened for incongruence of phylogenies based on a representative housekeeping gene (gyrB or pyrH) and a representative lux gene (luxA). Strains exhibiting incongruence were then subjected to detailed phylogenetic analysis of horizontal transfer by using multiple housekeeping genes (gyrB, recA, and pyrH) and multiple lux genes (luxCDABEG). In nearly all cases, housekeeping gene and lux gene phylogenies were congruent, and there was no instance in which the lux genes of one luminous species had replaced the lux genes of another luminous species. Therefore, the lux genes are predominantly vertically inherited in Vibrionaceae. The few exceptions to this pattern of congruence were as follows: (i) the lux genes of the only known luminous strain of Vibrio vulnificus, VVL1 (ATCC 43382), were evolutionarily closely related to the lux genes of Vibrio harveyi; (ii) the lux genes of two luminous strains of Vibrio chagasii, 21N-12 and SB-52, were closely related to those of V. harveyi and Vibrio splendidus, respectively; (iii) the lux genes of a luminous strain of Photobacterium damselae, BT-6, were closely related to the lux genes of the lux-rib(2) operon of Photobacterium leiognathi; and (iv) a strain of the luminous bacterium Photobacterium mandapamensis was found to be merodiploid for the lux genes, and the second set of lux genes was closely related to the lux genes of the lux-rib(2) operon of P. leiognathi. In none of these cases of apparent HGT, however, did acquisition of the lux genes correlate with phylogenetic divergence of the recipient strain from other members of its species. The results indicate that horizontal transfer of the lux genes in nature is rare and that horizontal acquisition of the lux genes apparently has not contributed to speciation in recipient taxa. PMID:18359809

Urbanczyk, Henryk; Ast, Jennifer C; Kaeding, Allison J; Oliver, James D; Dunlap, Paul V

2008-03-21

19

Phylogenetic Analysis of the Incidence of lux Gene Horizontal Transfer in Vibrionaceae? †  

PubMed Central

Horizontal gene transfer (HGT) is thought to occur frequently in bacteria in nature and to play an important role in bacterial evolution, contributing to the formation of new species. To gain insight into the frequency of HGT in Vibrionaceae and its possible impact on speciation, we assessed the incidence of interspecies transfer of the lux genes (luxCDABEG), which encode proteins involved in luminescence, a distinctive phenotype. Three hundred three luminous strains, most of which were recently isolated from nature and which represent 11 Aliivibrio, Photobacterium, and Vibrio species, were screened for incongruence of phylogenies based on a representative housekeeping gene (gyrB or pyrH) and a representative lux gene (luxA). Strains exhibiting incongruence were then subjected to detailed phylogenetic analysis of horizontal transfer by using multiple housekeeping genes (gyrB, recA, and pyrH) and multiple lux genes (luxCDABEG). In nearly all cases, housekeeping gene and lux gene phylogenies were congruent, and there was no instance in which the lux genes of one luminous species had replaced the lux genes of another luminous species. Therefore, the lux genes are predominantly vertically inherited in Vibrionaceae. The few exceptions to this pattern of congruence were as follows: (i) the lux genes of the only known luminous strain of Vibrio vulnificus, VVL1 (ATCC 43382), were evolutionarily closely related to the lux genes of Vibrio harveyi; (ii) the lux genes of two luminous strains of Vibrio chagasii, 21N-12 and SB-52, were closely related to those of V. harveyi and Vibrio splendidus, respectively; (iii) the lux genes of a luminous strain of Photobacterium damselae, BT-6, were closely related to the lux genes of the lux-rib2 operon of Photobacterium leiognathi; and (iv) a strain of the luminous bacterium Photobacterium mandapamensis was found to be merodiploid for the lux genes, and the second set of lux genes was closely related to the lux genes of the lux-rib2 operon of P. leiognathi. In none of these cases of apparent HGT, however, did acquisition of the lux genes correlate with phylogenetic divergence of the recipient strain from other members of its species. The results indicate that horizontal transfer of the lux genes in nature is rare and that horizontal acquisition of the lux genes apparently has not contributed to speciation in recipient taxa.

Urbanczyk, Henryk; Ast, Jennifer C.; Kaeding, Allison J.; Oliver, James D.; Dunlap, Paul V.

2008-01-01

20

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

PubMed

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

Ingerson-Mahar, Michael; Gitai, Zemer

2011-11-28

21

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

PubMed Central

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.

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

2003-01-01

22

Hydrolytic release, and identification by g.l.c.-m.s., of 3-deoxy-D-manno-2-octulosonic acid in the lipopolysaccharides isolated from bacteria of the Vibrionaceae.  

PubMed

The identification of the peracetylated methyl glycosides of 3-deoxy-D-manno-2-octulosonic acid (KDO) methyl esters was achieved by g.l.c.-m.s. These peracetylated methyl glycoside methyl esters were obtained from fully acetylated lipopolysaccharides and core oligosaccharides of representative strains of the Vibrionaceae family by the following sequence of mild reactions: acetolysis, methanolysis, and acetylation. KDO was shown to be present in all of the lipopolysaccharides (LPS), a result in direct contrast to the generally accepted view of the absence of this compound in LPS from this family of bacteria. PMID:6667475

Banoub, J H; Shaw, D H; Michon, F

1983-11-11

23

A widespread family of bacterial cell wall assembly proteins  

PubMed Central

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

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

2011-01-01

24

A family of lysozyme-like virulence factors in bacterial pathogens of plants and animals.  

PubMed Central

We describe a conserved family of bacterial gene products that includes the VirB1 virulence factor encoded by tumor-inducing plasmids of Agrobacterium spp., proteins involved in conjugative DNA transfer of broad-host-range bacterial plasmids, and gene products that may be involved in invasion by Shigella spp. and Salmonella enterica. Sequence analysis and structural modeling show that the proteins in this group are related to chicken egg white lysozyme and are likely to adopt a lysozyme-like structural fold. Based on their similarity to lysozyme, we predict that these proteins have glycosidase activity. Iterative data base searches with three conserved sequence motifs from this protein family detect a more distant relationship to bacterial and bacteriophage lytic transglycosylases, and goose egg white lysozyme. Two acidic residues in the VirB1 protein of Agrobacterium tumefaciens form a putative catalytic dyad, Each of these residues was changed into the corresponding amide by site-directed mutagenesis. Strains of A. tumefaciens that express mutated VirB1 proteins have a significantly reduced virulence. We hypothesize that many bacterial proteins involved in export of macromolecules belong to a widespread class of hydrolases and cleave beta-1,4-glycosidic bonds as part of their function. Images Fig. 2 Fig. 4

Mushegian, A R; Fullner, K J; Koonin, E V; Nester, E W

1996-01-01

25

Structural insights into host GTPase isoform selection by a family of bacterial GEF mimics.  

PubMed

The Escherichia coli type III effector Map belongs to a large family of bacterial virulence factors that activate host Rho GTPase signaling pathways through an unknown molecular mechanism. Here we report direct evidence that Map functions as a potent and selective guanine-nucleotide exchange factor (GEF) for Cdc42. The 2.3-A structure of the Map-Cdc42 complex revealed that Map mimics the GEF strategy of the mammalian Dbl family but has a three-dimensional architecture that is nearly identical to the bacterial GEF Salmonella spp. SopE. A comparative analysis between human and bacterial GEFs revealed a previously uncharacterized pairing mechanism between Map and the variable beta2-3 interswitch region of Cdc42. We propose a GTPase selection model that is experimentally validated by the preferential activation Rac1 and RhoA by the Shigella spp. effectors IpgB1 and IpgB2, respectively. These results significantly expand the repertoire of bacterial GEF mimics and unify a GEF selection mechanism for host GTPase substrates. PMID:19620963

Huang, Zhiwei; Sutton, Sarah E; Wallenfang, Adam J; Orchard, Robert C; Wu, Xiaojing; Feng, Yingcai; Chai, Jijie; Alto, Neal M

2009-07-20

26

Unconstrained bacterial promiscuity: the Tn 916–Tn 1545 family of conjugative transposons  

Microsoft Academic Search

Conjugative transposons are highly ubiquitous elements found throughout the bacterial world. Members of the Tn916–Tn1545 family carry the widely disseminated tetracycline-resistance determinant Tet M, as well as additional resistance genes. They have been found naturally in, or been introduced into, over 50 different species and 24 genera of bacteria. Recent investigations have led to insights into the molecular basis of

D. B. Clewell; S. E. Flannagan; D. D. Jaworski

1995-01-01

27

The acetylcholinesterase ichthyotoxin is a common component in the extracellular products of Vibrionaceae strains.  

PubMed

In previous work, it was reported that a strain of Aeromonas hydrophila (B32) produces the most potent lethal toxin with neurotoxic activity described so far for fish. In the present study, the presence and distribution of this acetylcholinesterase toxin lethal for fish were determined in extracellular products (ECP) of 42 Vibrionaceae strains using both immunological and colorimetric methods. This neurotoxin was shown to be present in the majority of the ECP from the Aeromonas and Vibrio strains tested and is responsible for the specific acetylcholinesterase activity. Also, although the Western blot and Ouchterlony techniques are valid as qualitative methods for the detection of this toxin, the Western blot procedure was 100-fold more sensitive than the Ouchterlony technique. PMID:15244056

Pérez, M J; Rodríguez, L A; Nieto, T P

1998-01-01

28

Chlorophyll a might structure a community of potentially pathogenic culturable Vibrionaceae. Insights from a one-year study of water and mussels surveyed on the French Atlantic coast.  

PubMed

The present study focused on the isolation of culturable bacteria from mussels and sea water to identify Vibrionaceae potentially pathogenic for humans. Three sites located on the French Atlantic coast were monitored monthly (twice each month during summer) for 1 year. Environmental parameters were surveyed (water temperature, salinity, turbidity, chlorophyll a) and bacteria were detected by culture and identified by API 20E(®) systems (BioMérieux) and PCR. A total of seven species were detected (Grimontia hollisae, Photobacterium damselae, Vibrio alginolyticus, V. cholerae, V. fluvialis, V. vulnificus and V. parahaemolyticus) and species diversity was higher at the end of summer. Surprisingly, V. cholerae non-O1/non-O139 was detected in spring. No site effect was detected. Using Sřrensen similarity indices and statistical analyses, we showed that chlorophyll a had a significant influence on the bacterial community detected in mussels and assemblages were more similar to one another when chlorophyll a values were above 20?µg?l(-1) . No significant effect of any parameter was found on the community detected in water samples. Such surveys are essential for the understanding of sanitary crises and detection of emerging pathogens. PMID:23766015

Deter, J; Lozach, S; Derrien, A; Véron, A; Chollet, J; Hervio-Heath, D

2010-02-01

29

Synthesis of glycoconjugates derived from various lipopolysaccharides of the Vibrionaceae family.  

PubMed

Conjugation of simple ketoses (such as 3-deoxy-D-manno-2-octulosonic acid and N-acetylneuraminic acid) and of various O-specific polysaccharides (from Aeromonas hydrophila and Aeromonas salmonicida) to the bifunctional spacer 1,6-hexanediamine, was achieved by reductive amination. The saccharide--1-(6-amino)-hexane alkyamines obtained were converted into the corresponding isothiocyanate derivatives and coupled to the free epsilon-amino group of lysine residues of the protein carrier bovine serum albumin. In similar manner, the aldehyde group introduced by selective periodate oxidation into the partially O-deacylated lipopolysaccharide of Vibrio anguillarum was conjugated to 1,6-hexanediamine, converted into the corresponding isothiocyanate and covalently attached to bovine serum albumin. PMID:2920731

Banoub, J H; Shaw, D H; Nakhla, N A; Hodder, H J

1989-02-15

30

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

PubMed

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

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

2012-11-09

31

Acetone formation in the Vibrio family: a new pathway for bacterial leucine catabolism.  

PubMed

There is current interest in biological sources of acetone, a volatile organic compound that impacts atmospheric chemistry. Here, we determined that leucine-dependent acetone formation is widespread in the Vibrionaceae. Sixteen Vibrio isolates, two Listonella species, and two Photobacterium angustum isolates produced acetone in the presence of L-leucine. Shewanella isolates produced much less acetone. Growth of Vibrio splendidus and P. angustum in a fermentor with controlled aeration revealed that acetone was produced after a lag in late logarithmic or stationary phase of growth, depending on the medium, and was not derived from acetoacetate by nonenzymatic decarboxylation in the medium. L-Leucine, but not D-leucine, was converted to acetone with a stoichiometry of approximately 0.61 mol of acetone per mol of L-leucine. Testing various potential leucine catabolites as precursors of acetone showed that only alpha-ketoisocaproate was efficiently converted by whole cells to acetone. Acetone production was blocked by a nitrogen atmosphere but not by electron transport inhibitors, suggesting that an oxygen-dependent reaction is required for leucine catabolism. Metabolic labeling with deuterated (isopropyl-d(7))-L-leucine revealed that the isopropyl carbons give rise to acetone with full retention of deuterium in each methyl group. These results suggest the operation of a new catabolic pathway for leucine in vibrios that is distinct from the 3-hydroxy-3-methylglutaryl-coenzyme A pathway seen in pseudomonads. PMID:10601206

Nemecek-Marshall, M; Wojciechowski, C; Wagner, W P; Fall, R

1999-12-01

32

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

PubMed Central

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.

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

2013-01-01

33

The OmpA family of proteins: roles in bacterial pathogenesis and immunity.  

PubMed

The OmpA family of outer membrane proteins is a group of genetically related, heat-modifiable, surface-exposed, porin proteins that are in high-copy number in the outer membrane of mainly Gram-negative bacteria. OmpA proteins are characterized by an N-terminal domain that forms an eight-stranded, anti-parallel ? barrel, which is embedded in the outer membrane. The C-terminal domain is globular and located in the periplasmic space. Escherichia coli OmpA is the best characterized of the proteins. Other well-characterized OmpA-equivalent proteins from pathogenic bacteria include Pseudomonas aeruginosa OprF, Haemophilus influenzae P5, Klebsiella pneumoniae OmpA, and Chlamydia trachomatis major outer membrane protein (MOMP). OmpA from the veterinary pathogens Mannheimia haemolytica, Haemophilus parasuis, Leptospira interrogans, and Pasteurella multocida have been studied to a lesser extent. Among many of the pathogenic bacteria, OmpA proteins have important pathogenic roles including bacterial adhesion, invasion, or intracellular survival as well as evasion of host defenses or stimulators of pro-inflammatory cytokine production. These pathogenic roles are most commonly associated with central nervous system, respiratory and urogenital diseases. Alternatively, OmpA family proteins can serve as targets of the immune system with immunogenicity related to surface-exposed loops of the molecule. In several cases, OmpA proteins are under evaluation as potential vaccine candidates. PMID:22986056

Confer, Anthony W; Ayalew, Sahlu

2012-08-31

34

A versatile plasmid biosensor useful to identify quorum sensing LuxR-family orphans in bacterial strains.  

PubMed

Eight luxI-family gene promoters (luxI, cviI, ahlI, rhlI, cepI, phzI, traI and ppuI) were cloned in tandem, upstream a promoterless lacZ gene in a promoter probe vector yielding pMULTIAHLPROM. This unique construct is useful in determining whether a bacterial strain not producing N-acyl homoserine lactone signal molecules (AHLs) possesses orphan LuxR type proteins able to respond to AHLs and activate transcription from quorum sensing target genes. Using pMULTIAHLPROM, it was demonstrated that Enterobacter aerogenes possibly contains a LuxR-family orphan able to activate luxI-family promoters independently from AHLs. PMID:18420295

Steindler, Laura; Devescovi, Giulia; Subramoni, Sujatha; Venturi, Vittorio

2008-03-06

35

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

Microsoft Academic Search

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

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

2005-01-01

36

Mining the bacterial unknown proteome: identification and characterization of a novel family of highly conserved protective antigens in Staphylococcus aureus.  

PubMed

In the human pathogen Staphylococcus aureus, there exists an enormous diversity of proteins containing DUFs (domains of unknown function). In the present study, we characterized the family of conserved staphylococcal antigens (Csa) classified as DUF576 and taxonomically restricted to Staphylococci. The 18 Csa paralogues in S. aureus Newman are highly similar at the sequence level, yet were found to be expressed in multiple cellular locations. Extracellular Csa1A was shown to be post-translationally processed and released. Molecular interaction studies revealed that Csa1A interacts with other Csa paralogues, suggesting that these proteins are involved in the same cellular process. The structures of Csa1A and Csa1B were determined by X-ray crystallography, unveiling a peculiar structure with limited structural similarity to other known proteins. Our results provide the first detailed biological characterization of this family and confirm the uniqueness of this family also at the structural level. We also provide evidence that Csa family members elicit protective immunity in in vivo animal models of staphylococcal infections, indicating a possible important role for these proteins in S. aureus biology and pathogenesis. These findings identify the Csa family as new potential vaccine candidates, and underline the importance of mining the bacterial unknown proteome to identify new targets for preventive vaccines. PMID:23895222

Schluepen, Christina; Malito, Enrico; Marongiu, Ambra; Schirle, Markus; McWhinnie, Elisabeth; Lo Surdo, Paola; Biancucci, Marco; Falugi, Fabiana; Nardi-Dei, Vincenzo; Marchi, Sara; Fontana, Maria Rita; Lombardi, Benedetta; De Falco, Maria Grazia; Rinaudo, C Daniela; Spraggon, Glen; Nissum, Mikkel; Bagnoli, Fabio; Grandi, Guido; Bottomley, Matthew J; Liberatori, Sabrina

2013-11-01

37

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

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.

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

2006-01-01

38

Anopheles gambiae Ag-STAT, a new insect member of the STAT family, is activated in response to bacterial infection.  

PubMed Central

A new insect member of the STAT family of transcription factors (Ag-STAT) has been cloned from the human malaria vector Anopheles gambiae. The domain involved in DNA interaction and the SH2 domain are well conserved. Ag-STAT is most similar to Drosophila D-STAT and to vertebrate STATs 5 and 6, constituting a proposed ancient class A of the STAT family. The mRNA is expressed at all developmental stages, and the protein is present in hemocytes, pericardial cells, midgut, skeletal muscle and fat body cells. There is no evidence of transcriptional activation following bacterial challenge. However, bacterial challenge results in nuclear translocation of Ag-STAT protein in fat body cells and induction of DNA-binding activity that recognizes a STAT target site. In vitro treatment with pervanadate (vanadate and H2O2) translocates Ag-STAT to the nucleus in midgut epithelial cells. This is the first evidence of direct participation of the STAT pathway in immune responses in insects.

Barillas-Mury, C; Han, Y S; Seeley, D; Kafatos, F C

1999-01-01

39

Ultrastructural and molecular characterization of a bacterial symbiosis in the ecologically important scale insect family Coelostomidiidae.  

PubMed

Scale insects are important ecologically and as agricultural pests. The majority of scale insect taxa feed exclusively on plant phloem sap, which is carbon rich but deficient in essential amino acids. This suggests that, as seen in the related aphids and psyllids, scale insect nutrition might also depend upon bacterial symbionts, yet very little is known about scale insect-bacteria symbioses. We report here the first identification and molecular characterization of symbiotic bacteria associated with the New Zealand giant scale Coelostomidia wairoensis, using fluorescence in situ hybridization (FISH), transmission electron microscopy (TEM) and 16S rRNA gene-based analysis. Dissection and FISH confirmed the location of the bacteria in large, paired, multilobate organs in the abdominal region of the insect. TEM indicated that the dominant pleomorphic bacteria were confined to bacteriocytes in the sheath-enclosed bacteriome. Phylogenetic analysis revealed the presence of three distinct bacterial types, the bacteriome-associated B-symbiont (Bacteroidetes), an Erwinia-related symbiont (Gammaproteobacteria) and Wolbachia sp. (Alphaproteobacteria). This study extends the current knowledge of scale insect symbionts and is the first microbiological investigation of the ecologically important coelostomidiid scales. PMID:22468989

Dhami, Manpreet K; Turner, Adrian P; Deines, Peter; Beggs, Jacqueline R; Taylor, Michael W

2012-04-23

40

Detection and Identification of Bacterial Endosymbionts in Arbuscular Mycorrhizal Fungi Belonging to the Family Gigasporaceae  

Microsoft Academic Search

Intracellular bacteria have been found previously in one isolate of the arbuscular mycorrhizal (AM) fungus Gigaspora margarita BEG 34. In this study, we extended our investigation to 11 fungal isolates obtained from different geographic areas and belonging to six different species of the family Gigasporaceae. With the exception of Gigaspora rosea, isolates of all of the AM species harbored bacteria,

VALERIA BIANCIOTTO; ERICA LUMINI; LUISA LANFRANCO; DANIELA MINERDI; PAOLA BONFANTE; SILVIA PEROTTO

2000-01-01

41

The first ?-1,3-glucosidase from bacterial origin belonging to glycoside hydrolase family 31  

Microsoft Academic Search

Genome analysis of Lactobacillus johnsonii NCC533 has been recently completed. One of its annotated genes, lj0569, encodes the protein having the conserved domain of glycoside hydrolase family 31. Its homolog gene (ljag31) in L. johnsonii NBRC13952 was cloned and expressed using an Escherichia coli expression system, resulting in poor production of recombinant LJAG31 protein due to inclusion body formation. Production

Min-Sun Kang; Masayuki Okuyama; Haruhide Mori; Atsuo Kimura

2009-01-01

42

Computational prediction of conserved operons and phylogenetic footprinting of transcription regulatory elements in the metal-reducing bacterial family Geobacteraceae.  

PubMed

Members of the family Geobacteraceae are an important group of microorganisms from the delta subdivision of Proteobacteria that couple the oxidation of organic compounds to metal reduction. In order to uncover transcription regulatory interactions in these organisms, we used computational methods to identify conserved operons and putative cis-regulatory transcription elements. We identified 26 putative operons with gene order and function conserved among two species of Geobacteraceae, Geobacter sulfurreducens and Geobacter metallireducens. Most of these operons were also conserved in Desulfovibrio vulgaris, an additional metal reducing organism from family Desulfovibrionaceae of the delta subdivision of Proteobacteria. The predicted conserved operons were investigated for the presence of transcription factor binding sites by two different methods, (i) comparison of non-coding regions in conserved operons, and (ii) neural network promoter prediction. Predicted motifs were screened to identify most likely transcription factor binding sites and ribosome-binding sites. We provide information on motifs in Geobacteraceae similar to known transcription factor binding sites in Escherichia coli, conserved motifs in other bacterial species, putative palindromic sites, and predicted ribosome-binding sites. These predictions will aid in further elucidation of regulatory networks of gene interactions in Geobacteraceae. PMID:15276006

Yan, Bin; Methé, Barbara A; Lovley, Derek R; Krushkal, Julia

2004-09-01

43

The adenylyltransferase domain of bacterial Pnkp defines a unique RNA ligase family  

PubMed Central

Pnkp is the end-healing and end-sealing component of an RNA repair system present in diverse bacteria from ten different phyla. To gain insight to the mechanism and evolution of this repair system, we determined the crystal structures of the ligase domain of Clostridium thermocellum Pnkp in three functional states along the reaction pathway: apoenzyme, ligase•ATP substrate complex, and covalent ligase-AMP intermediate. The tertiary structure is composed of a classical ligase nucleotidyltransferase module that is embellished by a unique ?-helical insert module and a unique C-terminal ?-helical module. Structure-guided mutational analysis identified active site residues essential for ligase adenylylation. Pnkp defines a new RNA ligase family with signature structural and functional properties.

Smith, Paul; Wang, Li Kai; Nair, Pravin A.; Shuman, Stewart

2012-01-01

44

REPAT, a new family of proteins induced by bacterial toxins and baculovirus infection in Spodoptera exigua.  

PubMed

Insect larvae spend most of their time eating and the digestive tract is the most crucial barrier for the entrance of many pathogens. In our study, suppression subtractive hybridization (SSH) was used to compare Spodoptera exigua midgut gene expression between larvae exposed to the Bacillus thuringiensis Cry1Ca toxin and non-exposed insects. Based on the SSH results, full cDNA sequences coding for four homologous proteins were obtained. Quantitative and semi-quantitative RT-PCR showed the increased expression of the genes coding for these proteins after exposure to different B. thuringiensis toxins as well as after infection with baculovirus. The proteins were named REPAT after their increased expression in Response to Pathogen. REPAT1, a member of this family, was recombinantly expressed using the baculovirus expression system, revealing the glycosylated nature of the protein. Recombinant baculoviruses expressing REPAT1 were used to infect larvae from S. exigua, showing that expression of REPAT1 was reducing the virulence of baculovirus to the infected larvae. Together, these results suggest a role for REPAT1 in mitigating pathological effects. PMID:17916497

Herrero, Salvador; Ansems, Marleen; Van Oers, Monique M; Vlak, Just M; Bakker, Petra L; de Maagd, Ruud A

2007-06-27

45

Genetic evidence of a coupling role for the TraG protein family in bacterial conjugation.  

PubMed

The ability of conjugative plasmids from six different incompatibility groups to mobilize a set of mobilizable plasmids was examined. The mobilization frequencies of plasmids RSF1010, ColE1, ColE3, and CloDF13 varied over seven orders of magnitude, depending on the helper conjugative plasmid used. Mobilization of CloDF13 was unique in that it did not require TrwB, TraG or TraD (all members of the TraG family) for mobilization by R388, RP4 or F, respectively. CloDF13 itself codes for an essential mobilization protein (MobB) which is also a TraG homolog, only requiring a source of the genes for pilus formation. Besides, CloDF13 was mobilized efficiently by all conjugative plasmids, suggesting that TraG homologs are the primary determinants of the mobilization efficiency of a plasmid, interacting differentially with the various relaxosomes. Previous results indicated that TraG and TrwB were interchangeable for mobilization of RSF1010 and ColE1 by PILw (the pilus system of IncW plasmids) but TraG could not complement conjugation of trwB mutants, suggesting that additional interactions were taking place between TrwB and oriT(R388) that were not essential for mobilization. To further test this hypothesis, we analyzed the mobilization frequencies of ColE1 and RSF1010 by the P, W, and F pili in the presence of alternative TraG homologs. The results obtained indicated that the frequency of mobilization was determined both by the particular TraG-like protein used and by the pilus system. Thus, TraG-like proteins are not generally interchangeable for mobilization. Therefore we suggest that the factors that determine the frequencies of transfer of different MOB regions are the differential interactions of TrwB with pilus and relaxosome. PMID:9180693

Cabezón, E; Sastre, J I; de la Cruz, F

1997-04-28

46

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

PubMed

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

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

2008-07-15

47

CheA protein, a central regulator of bacterial chemotaxis, belongs to a family of proteins that control gene expression in response to changing environmental conditions.  

PubMed Central

During bacterial chemotaxis, the binding of stimulatory ligands to chemoreceptors at the cell periphery leads to a response at the flagellar motor. Three proteins appear to be required for receptor-mediated control of swimming behavior, the products of the cheA, cheW, and cheY genes. Here we present the complete nucleotide sequence of the Salmonella typhimurium cheA gene together with the purification and characterization of its protein product. The protein is a 73,000 Mr cytoplasmic constituent. Amino acid-sequence comparisons indicate that it belongs to a family of bacterial regulatory proteins including the products of the cpxA, dctB, envZ, ntrB, phoR, phoM, and virA genes. Each member of this family has a conserved domain of approximately equal to 200 residues within its C terminus. We have previously shown that another chemotaxis protein, CheY, represents a domain of protein structure that has been conserved within a second large family of bacterial regulatory proteins. Each protein of the CheA family seems to function as a regulator of a different CheY homologue. Although each pair of proteins appears to produce a specialized response to a distinct type of stimulus, the relationships in primary structure suggest that a similar molecular mechanism may be involved. Images

Stock, A; Chen, T; Welsh, D; Stock, J

1988-01-01

48

CheA protein, a central regulator of bacterial chemotaxis, belongs to a family of proteins that control gene expression in response to changing environmental conditions.  

PubMed

During bacterial chemotaxis, the binding of stimulatory ligands to chemoreceptors at the cell periphery leads to a response at the flagellar motor. Three proteins appear to be required for receptor-mediated control of swimming behavior, the products of the cheA, cheW, and cheY genes. Here we present the complete nucleotide sequence of the Salmonella typhimurium cheA gene together with the purification and characterization of its protein product. The protein is a 73,000 Mr cytoplasmic constituent. Amino acid-sequence comparisons indicate that it belongs to a family of bacterial regulatory proteins including the products of the cpxA, dctB, envZ, ntrB, phoR, phoM, and virA genes. Each member of this family has a conserved domain of approximately equal to 200 residues within its C terminus. We have previously shown that another chemotaxis protein, CheY, represents a domain of protein structure that has been conserved within a second large family of bacterial regulatory proteins. Each protein of the CheA family seems to function as a regulator of a different CheY homologue. Although each pair of proteins appears to produce a specialized response to a distinct type of stimulus, the relationships in primary structure suggest that a similar molecular mechanism may be involved. PMID:3278311

Stock, A; Chen, T; Welsh, D; Stock, J

1988-03-01

49

A Unique Group of Virus-Related, Genome-Integrating Elements Found Solely in the Bacterial Family Thermaceae and the Archaeal Family Halobacteriaceae? †  

PubMed Central

Viruses SH1 and P23-77, infecting archaeal Haloarcula species and bacterial Thermus species, respectively, were recently designated to form a novel viral lineage. In this study, the lineage is expanded to archaeal Halomicrobium and bacterial Meiothermus species by analysis of five genome-integrated elements that share the core genes with these viruses.

Jalasvuori, Matti; Pawlowski, Alice; Bamford, Jaana K. H.

2010-01-01

50

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

PubMed Central

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.

Charbonneau, David M.; Beauregard, Marc

2013-01-01

51

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

PubMed Central

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 proteins. Results Metazoan PBP-?L homologs including LACTB share unique structural features with bacterial class B low molecular weight penicillin-binding proteins. The amino acid residues necessary for enzymatic activity in bacterial PBP-?L proteins, including the catalytic serine residue, are conserved in all metazoan homologs. Phylogenetic analysis indicated that metazoan PBP-?L homologs comprise four alloparalogus protein lineages that derive from ?-proteobacteria. Conclusion While most components of the peptidoglycan synthesis machinery were dumped by early eukaryotes, a few PBP-?L proteins were conserved and are found in metazoans including humans. Metazoan PBP-?L homologs are active-site-serine enzymes that probably have distinct functions in the metabolic circuitry. We hypothesize that PBP-?L proteins in the early eukaryotic cell enabled the degradation of peptidoglycan from ingested bacteria, thereby maximizing the yield of nutrients and streamlining the cell for effective phagocytotic feeding.

2008-01-01

52

Rab11-family of interacting protein 2 associates with chlamydial inclusions through its Rab-binding domain and promotes bacterial multiplication.  

PubMed

Chlamydia trachomatis, an obligate intracellular pathogen, survives within host cells in a special compartment named 'inclusion' and takes advantage of host vesicular transport pathways for its growth and replication. Rab GTPases are key regulatory proteins of intracellular trafficking. Several Rabs, among them Rab11 and Rab14, are implicated in chlamydial development. FIP2, a member of the Rab11-Family of Interacting Proteins, presents at the C-terminus a Rab-binding domain that interacts with both Rab11 and Rab14. In this study, we determined and characterized the recruitment of endogenous and GFP-tagged FIP2 to the chlamydial inclusions. The recruitment of FIP2 is specific since other members of the Rab11-Family of Interacting Proteins do not associate with the chlamydial inclusions. The Rab-binding domain of FIP2 is essential for its association. Our results indicate that FIP2 binds to Rab11 at the chlamydial inclusion membrane through its Rab-binding domain. The presence of FIP2 at the chlamydial inclusion favours the recruitment of Rab14. Furthermore, our results show that FIP2 promotes inclusion development and bacterial replication. In agreement, the silencing of FIP2 decreases the bacterial progeny. C.?trachomatis likely recruits FIP2 to hijack host intracellular trafficking to redirect vesicles full of nutrients towards the inclusion. PMID:23006599

Leiva, Natalia; Capmany, Anahí; Damiani, María Teresa

2012-11-01

53

Computational prediction of conserved operons and phylogenetic footprinting of transcription regulatory elements in the metal-reducing bacterial family Geobacteraceae  

Microsoft Academic Search

Members of the family Geobacteraceae are an important group of microorganisms from the delta subdivision of Proteobacteria that couple the oxidation of organic compounds to metal reduction. In order to uncover transcription regulatory interactions in these organisms, we used computational methods to identify conserved operons and putative cis-regulatory transcription elements. We identified 26 putative operons with gene order and function

Bin Yan; Barbara A. Methé; Derek R. Lovley; Julia Krushkal

2004-01-01

54

Novel Cold-Adapted Alkaline Lipase from an Intertidal Flat Metagenome and Proposal for a New Family of Bacterial Lipases ? †  

PubMed Central

A new lipase, LipEH166, isolated from an intertidal flat metagenome, showed no amino acid similarity to any known lipolytic enzyme except in the consensus region. This suggested that LipEH166 and its homologues belong to a new family of lipolytic enzymes. Partial characterization indicated that LipEH166 is a novel cold-adapted alkaline lipase.

Kim, Eun-Young; Oh, Ki-Hoon; Lee, Mi-Hwa; Kang, Chul-Hyung; Oh, Tae-Kwang; Yoon, Jung-Hoon

2009-01-01

55

Structure of a bacterial glycoside hydrolase family 63 enzyme in complex with its glycosynthase product, and insights into the substrate specificity.  

PubMed

Proteins belonging to glycoside hydrolase family 63 (GH63) are found in bacteria, archaea and eukaryotes. Although the eukaryotic GH63 proteins have been identified as processing ?-glucosidase I, the substrate specificities of the bacterial and archaeal GH63 proteins are not clear. Here, we converted a bacterial GH63 enzyme, Escherichia coli YgjK, to a glycosynthase to probe its substrate specificity. Two mutants of YgjK (E727A and D324N) were constructed, and both mutants showed glycosynthase activity. The reactions of E727A with ?-D-glucosyl fluoride and monosaccharides showed that the largest amount of glycosynthase product accumulated when galactose was employed as an acceptor molecule. The crystal structure of E727A complexed with the reaction product indicated that the disaccharide bound at the active site was 2-O-?-D-glucopyranosyl-?-D-galactopyranose (Glc12Gal). A comparison of the structures of E727A-Glc12Gal and D324N-melibiose showed that there were two main types of conformation: the open and closed forms. The structure of YgjK adopted the closed form when subsite -1 was occupied by glucose. These results suggest that sugars containing the Glc12Gal structure are the most likely candidates for natural substrates of YgjK. PMID:23826932

Miyazaki, Takatsugu; Ichikawa, Megumi; Yokoi, Gaku; Kitaoka, Motomitsu; Mori, Haruhide; Kitano, Yoshikazu; Nishikawa, Atsushi; Tonozuka, Takashi

2013-07-26

56

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

PubMed Central

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

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

2011-01-01

57

Phylogenetic, structural and functional analyses of the LacI-GalR family of bacterial transcription factors.  

PubMed

Phylogenetic tree construction for 25 sequenced members of the LacI-GalR family (LGF) of transcription factors revealed that almost all branches are similar in length, radiating essentially from a single point. This observation suggests that most of these proteins arose by duplication events which occurred at a specific time in evolutionary history, and that further duplication events were rare. Analyses of the multiple alignment of the LGF proteins lead to suggestions regarding structure-function relationships and reveal that the helix-turn-helix DNA-binding motif of LGF proteins is similar in sequence to those of numerous non-homologous DNA-binding proteins. PMID:8543068

Nguyen, C C; Saier, M H

1995-12-18

58

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

PubMed Central

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

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

1997-01-01

59

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

PubMed Central

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

Renz, Patricia; Dettner, Konrad; Kehl, Siegfried

2012-01-01

60

Cycle inhibiting factors (CIFs) are a growing family of functional cyclomodulins present in invertebrate and mammal bacterial pathogens.  

PubMed

The cycle inhibiting factor (Cif) produced by enteropathogenic and enterohemorrhagic Escherichia coli was the first cyclomodulin to be identified that is injected into host cells via the type III secretion machinery. Cif provokes cytopathic effects characterized by G(1) and G(2) cell cycle arrests, accumulation of the cyclin-dependent kinase inhibitors (CKIs) p21(waf1/cip1) and p27(kip1) and formation of actin stress fibres. The X-ray crystal structure of Cif revealed it to be a divergent member of a superfamily of enzymes including cysteine proteases and acetyltransferases that share a conserved catalytic triad. Here we report the discovery and characterization of four Cif homologs encoded by different pathogenic or symbiotic bacteria isolated from vertebrates or invertebrates. Cif homologs from the enterobacteria Yersinia pseudotuberculosis, Photorhabdus luminescens, Photorhabdus asymbiotica and the beta-proteobacterium Burkholderia pseudomallei all induce cytopathic effects identical to those observed with Cif from pathogenic E. coli. Although these Cif homologs are remarkably divergent in primary sequence, the catalytic triad is strictly conserved and was shown to be crucial for cell cycle arrest, cytoskeleton reorganization and CKIs accumulation. These results reveal that Cif proteins form a growing family of cyclomodulins in bacteria that interact with very distinct hosts including insects, nematodes and humans. PMID:19308257

Jubelin, Grégory; Chavez, Carolina Varela; Taieb, Frédéric; Banfield, Mark J; Samba-Louaka, Ascel; Nobe, Rika; Nougayrčde, Jean-Philippe; Zumbihl, Robert; Givaudan, Alain; Escoubas, Jean-Michel; Oswald, Eric

2009-03-24

61

HutC/FarR-like bacterial transcription factors of the GntR family contain a small molecule-binding domain of the chorismate lyase fold.  

PubMed

Numerous bacterial transcription factors contain a DNA-binding helix-turn-helix domain and a signaling domain, linked together in a single polypeptide. Typically, this signaling domain is a small-molecule-binding domain that undergoes a conformational change upon recognizing a specific ligand. The HutC/FarR-like transcription factors of the GntR family are one of the largest groups of transcription factors in the proteomes of most free-living bacteria. Using sensitive sequence profile analysis we show that the HutC/FarR-like transcription factors contain a conserved ligand-binding domain, which possesses the same fold as chorismate lyase (Escherichia coli UbiC gene product). This relationship suggests that the C-terminal domain of the HutC/FarR-like transcription factors binds small molecules in a cleft similar to the substrate-binding site of the chorismate lyases. The sequence diversity within the predicted binding cleft of the HutC/FarR ligand-binding domains is consistent with the ability of these transcription factors to respond to diverse small molecules, such as histidine (HutC), fatty acids (FarR), sugars (TreR) and alkylphosphonate (PhnF). UbiC-like chorismate lyases function in the ubiquinone biosynthesis pathway, and have characteristic charged, catalytic residues. Genome comparisons reveal that chorismate lyase orthologs are found in several bacteria, chloroplasts of eukaryotic algae and euryarchaea. In contrast, the GntR transcription regulators lack the conserved catalytic residues of the chorismate lyases, and have so far been detected only in bacteria. An ancestral, generic small-molecule-binding domain appears to have given rise to the enzymatic and non-catalytic ligand-binding versions of the same fold under the influence of different selective pressures. PMID:12757941

Aravind, L; Anantharaman, Vivek

2003-05-16

62

Bacterial Fertilizers.  

National Technical Information Service (NTIS)

The term bacterial (microbial) fertilizers refers to preparations containing primarily active strains of the microorganisms mainly bacteria in sufficient numbers. This report covers various aspects of bacterial fertilizers: Nitrogen Preparation and Usage;...

W. V. B. Sundra Rao

1981-01-01

63

ABC transporters: bacterial exporters.  

PubMed Central

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

Fath, M J; Kolter, R

1993-01-01

64

Differential gene expression in bacterial symbionts from loliginid squids demonstrates variation between mutualistic and environmental niches  

PubMed Central

Summary Luminescent bacteria (?-Proteobacteria: Vibrionaceae) are found in complex bilobed light organs of both sepiolid and loliginid squids (Mollusca: Cephalopoda). Despite the existence of multiple strain colonization between Vibrio bacteria and loliginid squids, specificity at the genus level still exists and may influence interactions between symbiotic and free-living stages of the symbiont. The environmentally transmitted behaviour of Vibrio symbionts bestows a certain degree of recognition that exists prior and subsequent to the colonization process. Therefore, we identified bacterial genes required for successful colonization of loliginid light organs by examining transcripts solely expressed in either the light organ or free-living stages. Selective capture of transcribed sequences (SCOTS) was used to differentiate genes expressed by the same bacterium when thriving in two different environments (i.e. loliginid light organs and seawater). Genes specific for squid light organs included vulnibactin synthetase, outer membrane protein W and dihydroxy dehydratase, which have been associated with the maintenance of bacterial host associations in other systems. In contrast, genes that were solely expressed in the free-living condition consisted of transcripts recognized as important factors for bacterial survival in the environment. These transcripts included genes for methyl accepting chemotaxis proteins, arginine decarboxylase and chitinase. These results provide valuable information regarding mechanisms determining specificity, establishment, and maintenance of bacteria–squid associations.

Guerrero-Ferreira, Ricardo C.; Nishiguchi, Michele K.

2010-01-01

65

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

66

Engulfment of Neisseria gonorrhoeae: Revealing Distinct Processes of Bacterial Entry by Individual Carcinoembryonic Antigen-Related Cellular Adhesion Molecule Family Receptors  

Microsoft Academic Search

Individual Neisseria gonorrhoeae colony opacity-associated (Opa) protein variants can bind up to four dif- ferent carcinoembryonic antigen-related cellular adhesion molecule (CEACAM) receptors. Most human cells encountered by gonococci express a combination of CEACAM receptors, thereby complicating the elucidation of intracellular signaling pathways triggered by individual receptors. Here, we compare the process of bacterial engulfment by a panel of stably transfected

Shannon E. McCaw; Edward H. Liao; Scott D. Gray-Owen

2004-01-01

67

Análisis in vitro de la actividad antibacteriana Oedogonium capillare contra bacterias patógenas de peces In vitro analysis of the antibacterial activity of Oedogonium capillare against pathogenic bacteria in fi sh  

Microsoft Academic Search

The present study proved in vitro the capability of an extract of Oedogonium capillare, a fresh water green algae, to be an effec- tive antibacterial agent against 23 different bacterial species of Enterobacteriaceae, Pseudomonadaceae, Aeromonadaceae and Vibrionaceae families, that are pathogens in humans and important in aquaculture. All the different wild strains were isolated from Carassius auratus fi sh cultivated

Pilar Negrete Redondo; Guadalupe Figueroa; Jorge Romero Jarero; Roxana López

68

Isolation and Identification of Bacteria Associated with Adult Laboratory Mexican Fruit Flies, Anastrepha ludens (Diptera: Tephritidae)  

Microsoft Academic Search

From the guts of new and old colonies (female and male) of Mexican fruit flies, Anastrepha ludens (Diptera: Tephritidae), we identified a total of 18 different bacterial species belonging to the family Enterobacteriaceae,\\u000a Pseudomonadaceae, Vibrionaceae, Micrococcaceae, Deinococcacea, Bacillaceae, and the genus Listeria. Enterobacter, Providencia, Serratia, and Staphylococcus spp. were the most frequently isolated genera, with Citrobacter, Streptococcus, Aerococcus, and Listeria

Lyudmila V. Kuzina; John J. Peloquin; Don C. Vacek; Thomas A. Miller

2001-01-01

69

Bacterial vaginosis  

Microsoft Academic Search

Bacterial vaginosis, the most prevalent cause of vaginal discharge in the United States, is characterized microbiologically\\u000a by a shift in the vagina away from a lactobacillus-predominant flora and toward a predominantly anaerobic milieu. The cause\\u000a of bacterial vaginosis is unknown, but the epidemiology of the syndrome suggests that it is sexually associated. Bacterial\\u000a vaginosis has been associated with various complications,

Jane R. Schwebke

2000-01-01

70

Bacterial vaginosis  

Microsoft Academic Search

Bacterial vaginosis is the most common cause of vaginitis, affecting over 3 million women in the United States annually. Depopulation of lactobacilli from the normal vaginal flora and overgrowth of Gardnerella vaginalis and other anaerobic species are the presumed etiology. To date, no scientific evidence shows that bacterial vaginosis is a sexually transmitted disease. Malodorous vaginal discharge is the most

Jeff Wang

2000-01-01

71

Steroid degradation and two steroid-inducible enzymes in the marine bacterium H5  

Microsoft Academic Search

Natural and synthetic steroid hormones excreted into the environment are potentially threatening the population dynamics of all kinds of animals and public health. We have previously isolated a steroid degrading bacterial strain (H5) from the Baltic Sea, at Kiel, Germany. 16S-rRNA analysis showed that bacterial strain H5 belongs to the genus Vibrio, family Vibrionaceae and class Gamma-Proteobacteria. Bacterial strain H5

Yingying Sang; Guangming Xiong; Edmund Maser

2011-01-01

72

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

PubMed

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

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

2012-02-14

73

Bacterial meningitis  

Microsoft Academic Search

Opinion statement  Initial empiric therapy for community-acquired bacterial meningitis should be based on the possibility that penicillin-resistant\\u000a pneumococci may be the etiologic organisms and, hence, should include a combination of third-generation cephalosporin (cefotaxime\\u000a or ceftriaxone) and vancomycin. Ampicillin should be included if the patient has predisposing factors that are associated\\u000a with a risk for infection with Listeria monocytogenes. Bacterial isolates from

Karen L. Roos

1999-01-01

74

Bacterial Cystitis  

Microsoft Academic Search

Urinary tract infection is one of the most common health problems affecting patients of all ages. It is the most common nosocomial\\u000a bacterial infection in the elderly. Women are especially prone to urinary tract infections (UTIs). Although prostatitis syndrome\\u000a accounts for 25% of male office visits for genitourinary tract infections, only 5% are attributed to a bacterial cause. Acute\\u000a cystitis

Joseph B. Abdelmalak; Jeannette M. Potts

75

Creation and screening of a multi-family bacterial oxidoreductase library to discover novel nitroreductases that efficiently activate the bioreductive prodrugs CB1954 and PR-104A.  

PubMed

Two potentially complementary approaches to improve the anti-cancer strategy gene-directed enzyme prodrug therapy (GDEPT) are discovery of more efficient prodrug-activating enzymes, and development of more effective prodrugs. Here we demonstrate the utility of a flexible screening system based on the Escherichia coli SOS response to evaluate novel nitroreductase enzymes and prodrugs in concert. To achieve this, a library of 47 candidate genes representing 11 different oxidoreductase families was created and screened to identify the most efficient activators of two different nitroaromatic prodrugs, CB1954 and PR-104A. The most catalytically efficient nitroreductases were found in the NfsA and NfsB enzyme families, with NfsA homologues generally more active than NfsB. Some members of the AzoR, NemA and MdaB families also exhibited low-level activity with one or both prodrugs. The results of SOS screening in our optimised E. coli reporter strain SOS-R2 were generally predictive of the ability of nitroreductase candidates to sensitise E. coli to CB1954, and of the kcat/Km for each prodrug substrate at a purified protein level. However, we also found that not all nitroreductases express stably in human (HCT-116 colon carcinoma) cells, and that activity at a purified protein level did not necessarily predict activity in stably transfected HCT-116. These results highlight a need for all enzyme-prodrug partners for GDEPT to be assessed in the specific context of the vector and cell line that they are intended to target. Nonetheless, our oxidoreductase library and optimised screens provide valuable tools to identify preferred nitroreductase-prodrug combinations to advance to preclinical evaluation. PMID:23399641

Prosser, Gareth A; Copp, Janine N; Mowday, Alexandra M; Guise, Christopher P; Syddall, Sophie P; Williams, Elsie M; Horvat, Claire N; Swe, Pearl M; Ashoorzadeh, Amir; Denny, William A; Smaill, Jeff B; Patterson, Adam V; Ackerley, David F

2013-02-08

76

Bacterial rheotaxis  

PubMed Central

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

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

2012-01-01

77

Ss-bCNGa: a unique member of the bacterial cyclic nucleotide gated (bCNG) channel family that gates in response to mechanical tension.  

PubMed

Bacterial cyclic nucleotide gated (bCNG) channels are generally a nonmechanosensitive subset of the mechanosensitive channel of small conductance (MscS) superfamily. bCNG channels are composed of an MscS channel domain, a linking domain, and a cyclic nucleotide binding domain. Among bCNG channels, the channel domain of Ss-bCNGa, a bCNG channel from Synechocystis sp. PCC 6803, is most identical to Escherichia coli (Ec) MscS. This channel also exhibits limited mechanosensation in response to osmotic downshock assays, making it the only known full-length bCNG channel to respond to hypoosmotic stress. Here, we compare and contrast the ability of Ss-bCNGa to gate in response to mechanical tension with Se-bCNG, a nonmechanosensitive bCNG channel, and Ec-MscS, a prototypical mechanosensitive channel. Compared with Ec-MscS, Ss-bCNGa only exhibits limited mechanosensation, which is most likely a result of the inability of Ss-bCNGa to form the strong lipid contacts needed for significant function. Unlike Ec-MscS, Ss-bCNGa displays a mechanical response that increases with protein expression level, which may result from channel clustering driven by interchannel cation-? interactions. PMID:23052972

Malcolm, Hannah R; Heo, Yoon-Young; Caldwell, David B; McConnell, John K; Hawkins, Jessica F; Guayasamin, Ryann C; Elmore, Donald E; Maurer, Joshua A

2012-10-06

78

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

SciTech Connect

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

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

2006-01-01

79

Bacterial vaginosis  

Microsoft Academic Search

Bacterial vaginosis is a common cause of abnormal discharge in women of child-bearing age. It is present in 10–20% women in the UK, and may recur or regress spontaneously. It is not regarded as an STI because it can occur in virgin women, but it is more common in sexually active women. Other associations include smoking, partner change, having a

Phillip Hay

2005-01-01

80

Bacterial Biofertilizers  

Microsoft Academic Search

Many bacteria and fungi can enhance plant growth. The present review is limited to plant growth promoting rhizobacteria (PGPR). However, it includes endophytic bacteria that show plant growth enhancing activity as well. Also the best studied bacterial mechanisms of plant growth promotion are discussed, with a special emphasis on biological nitrogen fixation and synthesis of phytohormones, including less understood mechanisms

LUIS E. FUENTES-RAMIREZ; Jesus Caballero-Mellado

81

Sequence analysis and expression of the bacterial dichloromethane dehalogenase structural gene, a member of the glutathione S-transferase supergene family.  

PubMed

The nucleotide sequence of a cloned 2.8-kilobase-pair BamHI-PstI fragment containing dcmA, the dichloromethane dehalogenase structural gene from Methylobacterium sp. strain DM4, was determined. An open reading frame with a coding capacity of 287 amino acids (molecular weight, 37,430) was identified as dcmA by its agreement with the N-terminal amino acid sequence, the total amino acid composition, and the subunit size of the purified enzyme. Alignment of the deduced dichloromethane dehalogenase amino acid sequence with amino acid sequences of the functionally related eucaryotic glutathione S-transferases revealed three regions containing highly conserved amino acid residues and indicated that dcmA is a member of the glutathione S-transferase supergene family. The 5' terminus of in vivo dcmA transcripts was determined by nuclease S1 mapping to be 82 base pairs upstream of the GTG initiation codon of dcmA. Despite a putative promoter sequence with high resemblance to the Escherichia coli -10 and -35 consensus sequences, located at an appropriate distance from the transcription start point, dcmA was only marginally expressed in E. coli. The strong induction of dichloromethane dehalogenase in Methylobacterium sp. by dichloromethane was abolished by deleting the 1.3-kilobase-pair upstream region of dcmA. Plasmid constructs devoid of this region directed expression of dichloromethane dehalogenase at a constitutively induced level. PMID:2104602

La Roche, S D; Leisinger, T

1990-01-01

82

Sequence analysis and expression of the bacterial dichloromethane dehalogenase structural gene, a member of the glutathione S-transferase supergene family.  

PubMed Central

The nucleotide sequence of a cloned 2.8-kilobase-pair BamHI-PstI fragment containing dcmA, the dichloromethane dehalogenase structural gene from Methylobacterium sp. strain DM4, was determined. An open reading frame with a coding capacity of 287 amino acids (molecular weight, 37,430) was identified as dcmA by its agreement with the N-terminal amino acid sequence, the total amino acid composition, and the subunit size of the purified enzyme. Alignment of the deduced dichloromethane dehalogenase amino acid sequence with amino acid sequences of the functionally related eucaryotic glutathione S-transferases revealed three regions containing highly conserved amino acid residues and indicated that dcmA is a member of the glutathione S-transferase supergene family. The 5' terminus of in vivo dcmA transcripts was determined by nuclease S1 mapping to be 82 base pairs upstream of the GTG initiation codon of dcmA. Despite a putative promoter sequence with high resemblance to the Escherichia coli -10 and -35 consensus sequences, located at an appropriate distance from the transcription start point, dcmA was only marginally expressed in E. coli. The strong induction of dichloromethane dehalogenase in Methylobacterium sp. by dichloromethane was abolished by deleting the 1.3-kilobase-pair upstream region of dcmA. Plasmid constructs devoid of this region directed expression of dichloromethane dehalogenase at a constitutively induced level. Images FIG. 4

La Roche, S D; Leisinger, T

1990-01-01

83

Bacterial Rheotaxis  

NASA Astrophysics Data System (ADS)

Rheotaxis is the directed movement of an organism resulting from fluid velocity gradients, long studied in fish, aquatic invertebrates and spermatozoa. Here we show that rheotaxis also occurs in bacteria. Using controlled microfluidic shear flows, we demonstrate and quantify rheotaxis in Bacillus subtilis. A mathematical model of a bacterium swimming in a shear flow is in good agreement with observations and reveals that bacterial rheotaxis results from a subtle interplay between velocity gradients and the helical shape of flagella, which together generate a torque that reorients the cell, altering its swimming direction. The magnitude of the observed rheotactic velocity is comparable to typical chemotactic velocities, suggesting that rheotaxis can interfere with bacterial processes based on directed motility, such as foraging and infection.

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

2011-11-01

84

Bacterial Growth  

NSDL National Science Digital Library

Dr. Brett Finlay shows how bacteria can grow rapidly to incredible numbers, and also explains what limits this explosive growth. This resource would be great preparation material for a classroom discussion or video presentation for both the students and the teacher. This visual helps further broaden the knowledge of students in both the upper high school and college undergraduate on bacterial growth. The lecture is featured on the DVD 2000 and Beyond: Confronting the Microbe Menace, available free from HHMI. The video is 54 seconds long and available on WMV (10MB) and MOV (8MB). All Infection Disease videos can be found at http://www.hhmi.org/biointeractive/disease/video.html .

Howard Hughes Medical Institute (;)

2007-03-27

85

Bacterial Sulfite-Oxidizing Enzymes – Enzymes for Chemolithotrophs Only?  

Microsoft Academic Search

All known sulfite-oxidizing enzymes that have been studied in molecular detail belong to the sulfite oxidase family of molybdoenzymes.\\u000a The first bacterial enzymes in this family were only characterized in 2000, but by now it has become clear that bacterial\\u000a enzymes originating from many different types of bacteria may actually be the most abundant proteins in this enzyme family.\\u000a This

Ulrike Kappler

86

Bacterial symbionts and natural products  

PubMed Central

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.

Crawford, Jason M.; Clardy, Jon

2011-01-01

87

Mimicking GEFs: a common theme for bacterial pathogens.  

PubMed

Small molecular weight GTPases are master regulators of eukaryotic signalling, making them prime targets for bacterial virulence factors. Here, we review the recent advances made in understanding how bacterial type III secreted effector proteins directly activate GTPase signalling cascades. Specifically we focus on the SopE/WxxxE family of effectors that functionally mimic guanine nucleotide exchange factors (GEFs): the endogenous activators of Rho-family GTPases. Recent structural and biochemical studies have provided keen insight into both the signalling potency and substrate specificity of bacterial GEFs. Additionally, these bacterial GEFs display fascinating cell biological properties that provide insight into both host cell physiology and infectious disease strategies. PMID:21951829

Orchard, Robert C; Alto, Neal M

2011-12-01

88

Bacterial concrete  

NASA Astrophysics Data System (ADS)

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

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

2001-04-01

89

Bacterial tyrosinases.  

PubMed

Tyrosinases are nearly ubiquitously distributed in all domains of life. They are essential for pigmentation and are important factors in wound healing and primary immune response. Their active site is characterized by a pair of antiferromagnetically coupled copper ions, CuA and CuB, which are coordinated by six histidine residues. Such a "type 3 copper centre" is the common feature of tyrosinases, catecholoxidases and haemocycanins. It is also one of several other copper types found in the multi-copper oxidases (ascorbate oxidase, laccase). The copper pair of tyrosinases binds one molecule of atmospheric oxygen to catalyse two different kinds of enzymatic reactions: (1) the ortho-hydroxylation of monophenols (cresolase activity) and (2) the oxidation of o-diphenols to o-diquinones (catecholase activity). The best-known function is the formation of melanins from L-tyrosine via L-dihydroxyphenylalanine (L-dopa). The complicated hydroxylation mechanism at the active centre is still not completely understood, because nothing is known about their tertiary structure. One main reason for this deficit is that hitherto tyrosinases from eukaryotic sources could not be isolated in sufficient quantities and purities for detailed structural studies. This is not the case for prokaryotic tyrosinases from different Streptomyces species, having been intensively characterized genetically and spectroscopically for decades. The Streptomyces tyrosinases are non-modified monomeric proteins with a low molecular mass of ca. 30kDa. They are secreted to the surrounding medium, where they are involved in extracellular melanin production. In the species Streptomyces, the tyrosinase gene is part of the melC operon. Next to the tyrosinase gene (melC2), this operon contains an additional ORF called melC1, which is essential for the correct expression of the enzyme. This review summarizes the present knowledge of bacterial tyrosinases, which are promising models in order to get more insights in structure, enzymatic reactions and functions of "type 3 copper" proteins in general. PMID:16423650

Claus, Harald; Decker, Heinz

2005-09-06

90

Bacterial start site prediction  

Microsoft Academic Search

With the growing number of completely sequenced bacterial genes, accurate gene prediction in bacterial genomes remains an important problem. Although the existing tools predict genes in bacterial genomes with high overall accuracy, their ability to pinpoint the translation start site remains unsatisfactory. In this paper, we present a novel approach to bacterial start site prediction that takes into account multiple

Sridhar S. Hannenhalli; William S. Hayes; Artemis G. Hatzigeorgiou; James W. Fickett

1999-01-01

91

A single qrr gene is necessary and sufficient for LuxO-mediated regulation in Vibrio fischeri  

PubMed Central

Summary All members of the Vibrionaceae harbor LuxO, a response regulator that integrates outputs from various signaling systems, ultimately controlling specific traits that are crucial to the distinct biology of each species. LuxO is phosphorylated in response to low cell density, activating the transcription of a family of small RNAs called Qrrs, which in turn, control the levels of a global regulatory protein conserved within the Vibrionaceae. Although the function of each Qrr is similar, the number of qrr genes varies among the different species. Using a bioinformatics approach, we have determined the number of qrr genes in fully-sequenced Vibrionaceae members. Phylogenetic analysis suggests the most recent common ancestor of all Vibrionaceae shared a single, ancestral qrr gene, which duplicated and diverged into multiple qrr genes in some present-day vibrio lineages. To demonstrate that a single qrr gene is sufficient to mediate repression of LitR, the global regulator in Vibrio fischeri, we have performed a series of genetic and phenotypic analyses of the LuxO pathway and its output. Our studies contribute to a better understanding of the ancestral state of these pathways in vibrios, as well as to the evolution and divergence of other sRNAs within different bacterial lineages.

Miyashiro, Tim; Wollenberg, Michael S.; Cao, Xiaodan; Oehlert, Dane; Ruby, Edward G.

2010-01-01

92

Bacterial lipolytic enzymes: classification and properties.  

PubMed Central

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

Arpigny, J L; Jaeger, K E

1999-01-01

93

Photobacterium profundum sp. nov., a new, moderately barophilic bacterial species isolated from a deep-sea sediment.  

PubMed

A novel, moderately barophilic bacterium was isolated from a sediment sample obtained from the Ryukyu Trench, at a depth of 5110 m. The isolate, designated strain DSJ4, is a Gram-negative rod capable of growth between 4 degrees C and 18 degrees C under atmospheric pressure, with optimum growth displayed at 10 degrees C, and capable of growth at pressures between 0.1 MPa and 70 MPa at 10 degrees C, with optimum growth displayed at 10 MPa. Strain DSJ4 is a moderately barophilic bacterium, and shows no significant change in growth at pressures up to 50 MPa. Phylogenetic analysis of the 16S rRNA sequence of strain DSJ4 places this strain within the Photobacterium subgroup of the family Vibrionaceae, closely related to the strain SS9 that was independently isolated from the Sulu Trough. The temperature and pressure ranges for growth, cellular fatty acid composition, and assorted physiological and biochemical characteristics indicate that these strains differ from other Photobacterium species. Furthermore, both SS9 and DSJ4 displayed a low level of DNA similarity to other Photobacterium type strains. Based on these differences, these strains are proposed to represent a new deep-sea-type species. The name Photobacterium profundum (JCM10084) is proposed. PMID:9676237

Nogi, Y; Masui, N; Kato, C

1998-01-01

94

Bacterial Gene Transfer  

NSDL National Science Digital Library

This resource provides detailed instructions for carrying out several laboratory exercises relating to bacterial transformation and conjugation. In this multi-session experiment, students are exposed to various techniques in microbiology, including bacterial transformation and assay and sterile techniques.

Roberta Ellington (Northwestern University;); John Mordacq (Northwestern University;)

1991-01-01

95

Evolution of bacterial genomes.  

PubMed

This review examines evolution of bacterial genomes with an emphasis on RNA based life, the transition to functional DNA and small evolving genomes (possible plasmids) that led to larger, functional bacterial genomes. PMID:9111921

Trevors, J T

1997-03-01

96

Refined identification of Vibrio bacterial flora from Acanthasther planci based on biochemical profiling and analysis of housekeeping genes.  

PubMed

We used a polyphasic approach for precise identification of bacterial flora (Vibrionaceae) isolated from crown-of-thorns starfish (COTS) from Lizard Island (Great Barrier Reef, Australia) and Guam (U.S.A., Western Pacific Ocean). Previous 16S rRNA gene phylogenetic analysis was useful to allocate and identify isolates within the Photobacterium, Splendidus and Harveyi clades but failed in the identification of Vibrio harveyi-like isolates. Species of the V harveyi group have almost indistinguishable phenotypes and genotypes, and thus, identification by standard biochemical tests and 16S rRNA gene analysis is commonly inaccurate. Biochemical profiling and sequence analysis of additional topA and mreB housekeeping genes were carried out for definitive identification of 19 bacterial isolates recovered from sick and wild COTS. For 8 isolates, biochemical profiles and topA and mreB gene sequence alignments with the closest relatives (GenBank) confirmed previous 16S rRNA-based identification: V. fortis and Photobacterium eurosenbergii species (from wild COTS), and V natriegens (from diseased COTS). Further phylogenetic analysis based on topA and mreB concatenated sequences served to identify the remaining 11 V harveyi-like isolates: V. owensii and V. rotiferianus (from wild COTS), and V. owensii, V. rotiferianus, and V. harveyi (from diseased COTS). This study further confirms the reliability of topA-mreB gene sequence analysis for identification of these close species, and it reveals a wider distribution range of the potentially pathogenic V. harveyi group. PMID:22013751

Rivera-Posada, J A; Pratchett, M; Cano-Gomez, A; Arango-Gomez, J D; Owens, L

2011-09-01

97

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

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

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

2007-01-01

98

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  

PubMed Central

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 tract (URT) mucosae of the chinchilla, the predominant host used to model experimental OM. Recombinant cCRAMP exhibited alpha-helical secondary structure and killed the three main bacterial pathogens of OM. In situ hybridization showed cCRAMP mRNA production in epithelium of the chinchilla Eustachian tube and RT-PCR was used to amplify cCRAMP mRNA from several other tissues of the chinchilla URT. Quantitative RT-PCR analysis of chinchilla middle ear epithelial cells (CMEEs) incubated with either viral (influenza A virus, adenovirus, or RSV) or bacterial (nontypeable H. influenzae, M. catarrhalis, or S. pneumoniae) pathogens associated with OM demonstrated distinct microbe-specific patterns of altered expression. Collectively, these data showed that viruses and bacteria modulate AMP messages in the URT, which likely contributes to the disease course of OM.

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

2007-01-01

99

[Bacterial vaginitis: general overview].  

PubMed

Bacteria are the most frequently detected agents in women, clinically complaining of vaginal discharge. The studies have shown that the vaginal microflora of women with bacterial vaginitis have altered from Lactobacillus spp. to various anaerobic bacteria. Gardnerella vaginalis is found in vaginal flora of women with bacterial vaginitis as well as in healthy women, while anaerobic bacteria such as Mobiluncus and Prevotella are the causative agents for bacterial vaginosis. For the laboratory diagnosis of bacterial vaginitis, direct microscopy is one of the most commonly used methods, and for this purpose cervicovaginal smears are examined by staining Papanicolaou and Gram stains. Because of the demonstration of bacterial vaginitis in association with the obstetric diseases such as preterm labor and postpartum endometritis, is a risk factor, its importance has increased recently. In this review article, the microorganisms that cause bacterial vaginitis, their biological characteristics, and the diagnostic laboratory methods of infection, have been discussed. PMID:12838684

Demirezen, Sayeste

2003-01-01

100

Demonstrating Bacterial Flagella.  

ERIC Educational Resources Information Center

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

Porter, John R.; And Others

1992-01-01

101

Scansytem Bacterial Detection Device  

Center for Biologics Evaluation and Research (CBER)

... Scansytem Bacterial Detection Device. Applicant: Hemosystem, SA, Richmond, VA. 510(k) number: BK040031. Product: Scansytem ... More results from www.fda.gov/biologicsbloodvaccines/bloodbloodproducts/approvedproducts

102

Foster Families  

MedlinePLUS

... foster family? Let's find out. What Are Foster Families? The word "foster" means to help someone (or ... stressful time. Why Do Kids Live With Foster Families? Most often, a kid goes into a foster ...

103

On the Origins of a Vibrio Species  

Microsoft Academic Search

Thirty-two genome sequences of various Vibrionaceae members are compared, with emphasis on what makes V. cholerae unique. As few as 1,000 gene families are conserved across all the Vibrionaceae genomes analysed; this fraction roughly doubles for gene families conserved within the species V. cholerae. Of these, approximately 200 gene families that cluster on various locations of the genome are not

Tammi Vesth; Trudy M. Wassenaar; Peter F. Hallin; Lars Snipen; Karin Lagesen; David W. Ussery

2010-01-01

104

Family Literacy  

ERIC Educational Resources Information Center

Research indicates that family literacy programs can provide opportunities for educational success for parents and children. The benefits reaped by the children in family literacy workshops are presented.

Holloway, John H.

2004-01-01

105

Bacterial diversity in agroecosystems  

Microsoft Academic Search

All life forms rely on bacterial processes for their survival. Bacterial diversity is greater than the diversity of any other group of organisms. Bacteria are responsible for diverse metabolic functions that affect soil and plant health. Nutrient cycling, organic matter formation and decomposition, soil structure formation, and plant growth promotion are among the beneficial functions that bacteria perform. Deleterious effects

A. C. Kennedy

1999-01-01

106

Bacterial cell shape  

Microsoft Academic Search

Bacterial species have long been classified on the basis of their characteristic cell shapes. Despite intensive research, the molecular mechanisms underlying the generation and maintenance of bacterial cell shape remain largely unresolved. The field has recently taken an important step forward with the discovery that eukaryotic cytoskeletal proteins have homologues in bacteria that affect cell shape. Here, we discuss how

Matthew T. Cabeen; Christine Jacobs-Wagner

2005-01-01

107

Family Issues  

MedlinePLUS

... of families. Some have two parents, while others have a single parent. Sometimes there is no parent and grandparents raise grandchildren. Some children live in foster families, adoptive families, or in stepfamilies. Families are much more than groups of people who share the same genes or the same ...

108

[Family Involvement.  

ERIC Educational Resources Information Center

|This theme issue provides four articles that address family involvement in the transition of youth with disabilities from school to work. The first article, "Family Involvement" by Marge Goldberg and Shauna McDonald, offers evidence of the importance of family involvement at this stage of the individual's life, reports on families' experiences,…

Alliance: The Newsletter of the National Transition Alliance, 1996

1996-01-01

109

Modulation of Post-Antibiotic Bacterial Community Reassembly and Host Response by Candida albicans  

PubMed Central

The introduction of Candida albicans into cefoperazone-treated mice results in changes in bacterial community reassembly. Our objective was to use high-throughput sequencing to characterize at much greater depth the specific changes in the bacterial microbiome. The colonization of C. albicans significantly altered bacterial community reassembly that was evident at multiple taxonomic levels of resolution. There were marked changes in the levels of Bacteriodetes and Lactobacillaceae. Lachnospiraceae and Ruminococcaceae, the two most abundant bacterial families, did not change in relative proportions after antibiotics, but there were marked genera-level shifts within these two bacterial families. The microbiome shifts occurred in the absence of overt intestinal inflammation. Overall, these experiments demonstrate that the introduction of a single new microbe in numerically inferior numbers into the bacterial microbiome during a broad community disturbance has the potential to significantly alter the subsequent reassembly of the bacterial community as it recovers from that disturbance.

Erb Downward, John R.; Falkowski, Nicole R.; Mason, Katie L.; Muraglia, Ryan; Huffnagle, Gary B.

2013-01-01

110

QS-type bacterial signal molecules of nonpeptide origin  

Microsoft Academic Search

This review classifies and analyzes the literature data on bacterial autoinducers (AI), the signal molecules produced and\\u000a secreted by bacterial cells and responsible for intercellular communication (quorum sensing, QS). The most important families\\u000a of nonpeptide AI are discussed, including N-acyl homoserine lactones, derivatives of 2-methyl-2,3,4,5-tetrahydroxy tetrahydrofuran, indole and quinoline derivatives,\\u000a and adrenalinerelated compounds. The data is provided on the intracellular

A. O. Shpakov

2009-01-01

111

Fragile Families and Family Law  

Microsoft Academic Search

Family law reforms concerning paternity, child support, illegitimacy, and domestic violence have helped fragile families over the past 50 years. Yet fragile families remain invisible to much of family law because historically lawmakers have focused on the problems of the middle and upper classes. Also, the law still enshrines some confining stereotypes, thus encouraging the poor to enter into unstable,

LYNN D. WARDLE

112

Family Governance with Family Councils  

Microsoft Academic Search

From the third generation onwards, family firms could get into business threatening situations. This might depend on the growing number of owners, the increasing distance of family members from the firm, and the heterogeneity of their interests. Thus, agency prob- lems and negative conflicts might occur. This calls for the appropriate choice of family gov- ernance mechanisms. Family councils might

Klaus Brockhoff; Alexander Koeberle-Schmid

113

Acute Bacterial Meningitis  

MedlinePLUS

... risk of developing bacterial meningitis. Strength of the immune system: Which bacteria are likely to cause meningitis depends on whether the immune system is normal or weakened. Conditions that can weaken ...

114

TOLERANCE TO BACTERIAL PYROGENS  

PubMed Central

In experiments designed to elucidate the mechanism by which tolerance to bacterial pyrogens is developed, the following observations were made: 1. Animals whose febrile reactions to bacterial pyrogens were markedly diminished, as a result of repeated injections, showed increases in response following R-E blockade. 2. Pyrogenic substances disappeared from the circulating blood more rapidly in rabbits rendered pyrogen-tolerant than in normal animals. Lack of specificity was shown by the fact that rabbits previously injected with Eberthella typhosa bacterial vaccine were able to remove the pyrogens of Serratia marcescens and Pseudomonas aeruginosa from their blood more rapidly than normal animals. 3. R-E blockade-retarded the speed of disappearance of pyrogens from the circulating blood of animals which had been rendered relatively tolerant by previous injections of these substances. A possible mechanism for the development of unresponsiveness to bacterial pyrogens is suggested.

Beeson, Paul B.

1947-01-01

115

Small bowel bacterial overgrowth  

MedlinePLUS

Overgrowth - intestinal bacteria; Bacterial overgrowth - intestine ... Normally, the small intestine contains a low number of bacteria. This is different from the large intestine, which contains large numbers of bacteria. ...

116

Guards of the great wall: bacterial lysozyme inhibitors.  

PubMed

Peptidoglycan is the major structural component of the bacterial cell wall. It provides resistance against turgor and its cleavage by hydrolases such as lysozymes results in bacteriolysis. Most, if not all, animals produce lysozymes as key effectors of their innate immune system. Recently, highly specific bacterial proteinaceous lysozyme inhibitors against the three major animal lysozyme families have been discovered in bacteria, and these may represent a bacterial answer to animal lysozymes. Here, we will review their properties and phylogenetic distribution, present their structure and molecular interaction mechanism with lysozyme, and discuss their possible biological functions and potential applications. PMID:22840966

Callewaert, Lien; Van Herreweghe, Joris M; Vanderkelen, Lise; Leysen, Seppe; Voet, Arnout; Michiels, Chris W

2012-07-27

117

Bacterial delivery system  

US Patent & Trademark Office Database

We describe a bacterial delivery system for the delivery of DNA and antigens into cells. We constructed an attenuated bacterial vector which enters mammalian cells and ruptures delivering functional plasmid DNA and antigens into the cell cytoplasm. This Shigella vector was designed to deliver DNA to colonic surfaces, thus opening the possibility of oral and other mucosal DNA immunization and gene therapy strategies. The attenuated Shigella is also useful as a vaccine for reducing disease symptoms caused by Shigella.

Branstrom; Arthur A. (Rockville, MD); Sizemore; Donata R. (Gaithersburg, MD); Sadoff; Jerald C. (Washington, DC)

2006-05-16

118

DETECTION OF VIBRIOS IN OYSTERS CRASSOSTRTEA VIRGINICA AND SEAWATER USING A NEW, RAPID, SIMPLE, AND QUANTITATIVE ENZYME-BASED ASSAY  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Vibrionaceae family of bacteria contains important human and fish pathogens. We developed a rapid, simple, and quantitative detection method for members of the Vibrionaceae family. The assay, referred to as the colony overlay procedure for peptidases (COPP), is based on the rapid and inexpensiv...

119

Bacterial Biovolume and Biomass Estimations  

PubMed Central

The biomass of bacterial populations in aquatic ecosystems is often estimated by measuring bacterial biovolume and converting this into biomass in terms of carbon. A reliable conversion factor relating the measured bacterial biovolume to bacterial carbon content is essential for this approach. Based on direct measurements of bacterial cell carbon content, cell number, and biovolume, I have derived an average conversion factor of 5.6 × 10?13 g of C ?m?3. This conversion factor is 3.4 to 6.6 times higher than most theoretically derived factors currently in use. Both bacterial biomass and bacterial production in aquatic ecosystems may thus have been seriously underestimated.

Bratbak, Gunnar

1985-01-01

120

Bacterial growth with chlorinated methanes.  

PubMed

Chlorinated methanes are important industrial chemicals and significant environmental pollutants. While the highly chlorinated methanes, trichloromethane and tetrachloromethane, are not productively metabolized by bacteria, chloromethane and dichloromethane are used by both aerobic and anaerobic methylotrophic bacteria as carbon and energy sources. Some of the dehalogenation reactions involved in the utilization of the latter two compounds have been elucidated. In a strictly anaerobic acetogenic bacterium growing with chloromethane, an inducible enzyme forming methyltetrahydrofolate and chloride from chloromethane and tetrahydrofolate catalyzes dehalogenation of the growth substrate. A different mechanism for the nucleophilic displacement of chloride is observed in aerobic methylotrophic bacteria utilizing dichloromethane as the sole carbon and energy source. These organisms possess the enzyme dichloromethane dehalogenase which, in a glutathione-dependent reaction, converts dichloromethane to inorganic chloride and formaldehyde, a central metabolite of methylotrophic growth. Sequence comparisons have shown that bacterial dichloromethane dehalogenases belong to the glutathione S-transferase enzyme family, and within this family to class Theta. The dehalogenation reactions underlying aerobic utilization of chloromethane by a pure culture and anaerobic growth with dichloromethane by an acetogenic mixed culture are not known. It appears that they are based on mechanisms other than nucleophilic attack by tetrahydrofolate or glutathione. PMID:8565906

Leisinger, T; Braus-Stromeyer, S A

1995-06-01

121

Bacterial growth with chlorinated methanes.  

PubMed Central

Chlorinated methanes are important industrial chemicals and significant environmental pollutants. While the highly chlorinated methanes, trichloromethane and tetrachloromethane, are not productively metabolized by bacteria, chloromethane and dichloromethane are used by both aerobic and anaerobic methylotrophic bacteria as carbon and energy sources. Some of the dehalogenation reactions involved in the utilization of the latter two compounds have been elucidated. In a strictly anaerobic acetogenic bacterium growing with chloromethane, an inducible enzyme forming methyltetrahydrofolate and chloride from chloromethane and tetrahydrofolate catalyzes dehalogenation of the growth substrate. A different mechanism for the nucleophilic displacement of chloride is observed in aerobic methylotrophic bacteria utilizing dichloromethane as the sole carbon and energy source. These organisms possess the enzyme dichloromethane dehalogenase which, in a glutathione-dependent reaction, converts dichloromethane to inorganic chloride and formaldehyde, a central metabolite of methylotrophic growth. Sequence comparisons have shown that bacterial dichloromethane dehalogenases belong to the glutathione S-transferase enzyme family, and within this family to class Theta. The dehalogenation reactions underlying aerobic utilization of chloromethane by a pure culture and anaerobic growth with dichloromethane by an acetogenic mixed culture are not known. It appears that they are based on mechanisms other than nucleophilic attack by tetrahydrofolate or glutathione.

Leisinger, T; Braus-Stromeyer, S A

1995-01-01

122

Microfluidics for bacterial chemotaxis  

NASA Astrophysics Data System (ADS)

The emerging microfluidic technology opens up new opportunities for bacterial chemotaxis studies. In this talk, I will present our efforts in correlating molecular level events with cellular phenotypes in bacterial chemotaxis using microfabricated device. I will present results of bacterial chemotaxis in both single and dual chemical gradients. In single gradient experiments, we demonstrated that bacteria sense the chemical concentration at a logrithmic scale, similar to sensory system in higher organism. In dual gradient experiments, we showed that the number ratio of the two different types of receptor plays a critical role in bacteria's chemotactic decision making process. Experimental results based on single cell analysis will be presented. This work is supported by the National Science Foundation and the Cornell Nanobiotechnology Center.

Wu, Mingming

2012-02-01

123

[Diagnosis of bacterial vaginosis].  

PubMed

Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2-producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent's scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up-to-date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short-term and long-term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context. PMID:24073569

124

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

SciTech Connect

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

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

2006-01-01

125

Structure and operation of bacterial tripartite pumps.  

PubMed

In bacteria such as Pseudomonas aeruginosa and Escherichia coli, tripartite membrane machineries, or pumps, determine the efflux of small noxious molecules, such as detergents, heavy metals, and antibiotics, and the export of large proteins including toxins. They are therefore influential in bacterial survival, particularly during infections caused by multidrug-resistant pathogens. In these tripartite pumps an inner membrane transporter, typically an ATPase or proton antiporter, binds and translocates export or efflux substrates. In cooperation with a periplasmic adaptor protein it recruits and opens a TolC family cell exit duct, which is anchored in the outer membrane and projects across the periplasmic space between inner and outer membranes. Assembled tripartite pumps thus span the entire bacterial cell envelope. We review the atomic structures of each of the three pump components and discuss how these have allowed high-resolution views of tripartite pump assembly, operation, and possible inhibition. PMID:23808339

Hinchliffe, Philip; Symmons, Martyn F; Hughes, Colin; Koronakis, Vassilis

2013-06-26

126

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

Microsoft Academic Search

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,

LASZLO OTVOS; KRISZTINA BOKONYI; ISTVAN VARGA; BALINT I. OTVOS; RALF HOFFMANN; HILDEGUND C. J. ERTL; JOHN D. WADE; AILSA M. McMANUS; DAVID J. CRAIK; PHILIPPE BULET

2000-01-01

127

Bacterial mortality and the fate of bacterial production  

Microsoft Academic Search

Knowledge of the rates of bacterial mortality, particularly predatory mortality, is important in determining the fate of bacterial\\u000a production. Communities of planktonic bacteria have specific growth rates on the order of 1 d?1, but there is relatively little variation in bacterial abundance, implying that growth and mortality are closely coupled.\\u000a A review of the mechanisms of bacterial mortality suggests that

Michael L. Pace; Mary Flagler Cary Arboretum

1988-01-01

128

Ribonucleases and bacterial virulence.  

PubMed

Bacterial stress responses provide them the opportunity to survive hostile environments, proliferate and potentially cause diseases in humans and animals. The way in which pathogenic bacteria interact with host immune cells triggers a complicated series of events that include rapid genetic re-programming in response to the various host conditions encountered. Viewed in this light, the bacterial host-cell induced stress response (HCISR) is similar to any other well-characterized environmental stress to which bacteria must respond by upregulating a group of specific stress-responsive genes. Post stress, bacteria must resume their pre-stress genetic program, and, as a consequence, must degrade unnecessary stress responsive transcripts through RNA decay mechanisms. Further, there is a well-established role for several ribonucleases in the cold shock response whereby they modulate the changing transcript landscape in response to the stress, and during acclimation and subsequent genetic re-programming post stress. Recently, ribonucleases have been implicated as virulence-associated factors in several notable Gram-negative pathogens including, the yersiniae, the salmonellae, Helicobacter pylori, Shigella flexneri and Aeromonas hydrophila. This review will focus on the roles played by ribonucleases in bacterial virulence, other bacterial stress responses, and on their novel therapeutic applications. PMID:21375713

Lawal, Abidat; Jejelowo, Olufisayo; Chopra, Ashok K; Rosenzweig, Jason A

2010-10-15

129

Bacterial 'immunity' against bacteriophages  

PubMed Central

Vertebrate animals possess multiple anti-pathogen defenses. Individual mechanisms usually are differentiated into those that are immunologically adaptive vs. more “primitive” anti-pathogen phenomena described as innate responses. Here I frame defenses used by bacteria against bacteriophages as analogous to these animal immune functions. Included are numerous anti-phage defenses in addition to the adaptive immunity associated with CRISPR/cas systems. As these other anti-pathogen mechanisms are non-adaptive they can be described as making up an innate bacterial immunity. This exercise was undertaken in light of the recent excitement over the discovery that CRISPR/cas systems can serve, as noted, as a form of bacterial adaptive immunity. The broader goal, however, is to gain novel insight into bacterial defenses against phages by fitting these mechanisms into considerations of how multicellular organisms also defend themselves against pathogens. This commentary can be viewed in addition as a bid toward integrating these numerous bacterial anti-phage defenses into a more unified immunology.

2012-01-01

130

Bacterial extracellular lignin peroxidase  

DOEpatents

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

Crawford, Donald L. (Moscow, ID); Ramachandra, Muralidhara (Moscow, ID)

1993-01-01

131

Bacterial Transformation Lab  

NSDL National Science Digital Library

The "glowing genes" activity on this engaging website shows students the process of bacterial transformation, a specific type of genetic engineering. This online activity supplements a hands-on lab at the Dolan DNA Learning Center's Harlem DNA Lab, in which plasmids, or tiny loops of DNA that contain genes, are inserted into a harmless strain of E.coli.

Dolan DNA Learning Center * (Dolan DNA Learning Center;)

2010-05-27

132

Phagocytosis of bacterial pathogens.  

PubMed

Phagocytosis is an evolutionarily ancient, receptor-driven process, by which phagocytic cells recognize invading microbes and destroy them after internalization. The phagocytosis receptor Eater is expressed exclusively on Drosophila phagocytes and is required for the survival of bacterial infections. In a recent study, we explored how Eater can defend fruit flies against different kinds of bacteria. We discovered that Eater bound to certain types of bacteria directly, while for others bacterial binding was dependent on prior disruption of the bacterial envelope. Similar to phagocytes, antimicrobial peptides and lysozymes are ancient components of animal immune systems. Our results suggest that cationic antimicrobial peptides, as well as lysozymes, can facilitate Eater binding to live Gram-negative bacteria. Both types of molecules promote surface-exposure of bacterial ligands that otherwise would remain buried and hidden under an outer membrane. We propose that unmasking ligands for phagocytic receptors may be a conserved mechanism operating in many animals, including humans. Thus, studying a Drosophila phagocytosis receptor may advance our understanding of innate immunity in general. PMID:22223092

Chung, Yoon-Suk Alexander; Kocks, Christine

2012-01-01

133

Bacterial social engagements  

Microsoft Academic Search

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

Jennifer M. Henke; Bonnie L. Bassler

2004-01-01

134

Radiology of bacterial pneumonia  

Microsoft Academic Search

Bacterial pneumonia is commonly encountered in clinical practice. Radiology plays a prominent role in the evaluation of pneumonia. Chest radiography is the most commonly used imaging tool in pneumonias due to its availability and excellent cost benefit ratio. CT should be used in unresolved cases or when complications of pneumonia are suspected. The main applications of radiology in pneumonia are

José Vilar; Maria Luisa Domingo; Cristina Soto; Jonathan Cogollos

2004-01-01

135

Ribonucleases and Bacterial Virulence  

PubMed Central

Bacterial stress responses provide them the opportunity to survive hostile environments, proliferate, and potentially cause diseases in humans and animals. The way in which pathogenic bacteria interact with host immune cells triggers a complicated series of events that include rapid genetic re-programming in response to the various host conditions encountered. Viewed in this light, the bacterial host-cell induced stress response (HCISR) is similar to any other well characterized environmental stress to which bacteria must respond by up-regulating a group of specific stress-responsive genes. Post-stress, bacteria must resume their pre-stress genetic program, and, as a consequence, must degrade unnecessary stress responsive transcripts through RNA decay mechanisms. Further, there is a well established role for several ribonucleases in the cold shock response whereby they modulate the changing transcript landscape in response to the stress, and during acclimation and subsequent genetic re-programming post-stress. Recently, ribonucleases have been implicated as virulence associated factors in several notable gram-negative pathogens including, the yersiniae, the salmonellae, Helicobacter pylori, Shigella flexneri, and Aeromonas hydrophila. This review will focus on the roles played by ribonucleases in bacterial virulence, other bacterial stress responses, and on their novel therapeutic applications.

Lawal, Abidat; Jejelowo, Olufisayo; Chopra, Ashok K.; Rosenzweig, Jason A.

2010-01-01

136

Bacterial Assay of Urine.  

National Technical Information Service (NTIS)

The dip-slide technique for bacterial assay of urine has been found to be a competent method for isolating the usual organisms responsible for urinary tract infection. Being a simple device, reliable in transport, and commercially available, it would appe...

J. E. Sippel Z. Farid A. S. Diab

1972-01-01

137

Intercepting bacterial indole signaling with flustramine derivatives.  

PubMed

Indole signaling is one of the putative universal signaling networks in bacteria. We have investigated the use of desformylflustrabromine (dFBr) derivatives for the inhibition of biofilm formation through modulation of the indole-signaling network in Escherichia coli and Staphylococcus aureus . We have found dFBr derivatives that are 10-1000 times more active than indole itself, demonstrating that the flustramine family of indolic natural products represent a privileged scaffold for the design of molecules to control pathogenic bacterial behavior. PMID:22091927

Bunders, Cynthia A; Minvielle, Marine J; Worthington, Roberta J; Ortiz, Minoshka; Cavanagh, John; Melander, Christian

2011-11-22

138

Family Reunification  

ERIC Educational Resources Information Center

|Reunifying children placed in foster care with their birth parents is a primary goal of the child welfare system. Yet, relatively little is known about the reunification process. This article analyzes new data on trends in family reunification and discovers: (1) Although most children still exit foster care through family reunification, exit…

Wulczyn, Fred

2004-01-01

139

Bacterial Biofilms on Fungal Surfaces  

Microsoft Academic Search

Bacterial biofilm formation on fungi participates in the synergistic degradation of sub- strates, antagonism of fungal growth, bacterial utilization of fungi as nutrient sources, and the formation of more complex synergistic associations for the purposes of nutrient acquisition. While bacterial biofilm formation has been described in many systems, the molecular mechanisms that govern these interactions are not yet well understood.

Deborah A. Hogan; Matthew J. Wargo; Nancy Beck

140

Complete genome sequence of Vibrio fischeri: A symbiotic bacterium with pathogenic congeners  

Microsoft Academic Search

Vibrio fischeri belongs to the Vibrionaceae, a large family of marine -proteobacteria that includes several dozen species known to engage in a diversity of beneficial or pathogenic interactions with animal tissue. Among the small number of pathogenic Vibrio species that cause human diseases are Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus, the only members of the Vibrionaceae that have had

E. G. Ruby; M. Urbanowski; J. Campbell; A. Dunn; M. Faini; R. Gunsalus; P. Lostroh; C. Lupp; J. McCann; D. Millikan; A. Schaefer; E. Stabb; A. Stevens; K. Visick; C. Whistler; E. P. Greenberg

2005-01-01

141

Family Theory and Family Health Research  

PubMed Central

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.

Doherty, William J.

1991-01-01

142

Modelling bacterial flagellar growth  

NASA Astrophysics Data System (ADS)

The growth of bacterial flagellar filaments is a self-assembly process where flagellin molecules are transported through the narrow core of the flagellum and are added at the distal end. To model this situation, we generalize a growth process based on the TASEP model by allowing particles to move both forward and backward on the lattice. The bias in the forward and backward jump rates determines the lattice tip speed, which we analyze and also compare to simulations. For positive bias, the system is in a non-equilibrium steady state and exhibits boundary-induced phase transitions. The tip speed is constant. In the no-bias case we find that the length of the lattice grows as N(t)\\propto\\sqrt{t} , whereas for negative drift N(t)~ln t. The latter result agrees with experimental data of bacterial flagellar growth.

Schmitt, M.; Stark, H.

2011-10-01

143

Bacterial hypermutation: clinical implications.  

PubMed

Heritable hypermutation in bacteria is mainly due to alterations in the methyl-directed mismatch repair (MMR) system. MMR-deficient strains have been described from several bacterial species, and all of the strains exhibit increased mutation frequency and recombination, which are important mechanisms for acquired drug resistance in bacteria. Antibiotics select for drug-resistant strains and refine resistance determinants on plasmids, thus stimulating DNA recombination via the MMR system. Antibiotics can also act as indirect promoters of antibiotic resistance by inducing the SOS system and certain error-prone DNA polymerases. These alterations have clinical consequences in that efficacious treatment of bacterial infections requires high doses of antibiotics and/or a combination of different classes of antimicrobial agents. There are currently few new drugs with low endogenous resistance potential, and the development of such drugs merits further research. PMID:21349992

Jolivet-Gougeon, Anne; Kovacs, Bela; Le Gall-David, Sandrine; Le Bars, Hervé; Bousarghin, Latifa; Bonnaure-Mallet, Martine; Lobel, Bernard; Guillé, François; Soussy, Claude-James; Tenke, Peter

2011-02-24

144

[Bacterial diseases of rape].  

PubMed

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

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

145

Physics of Bacterial Morphogenesis  

PubMed Central

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.

Sun, Sean X.; Jiang, Hongyuan

2011-01-01

146

Flagella and bacterial pathogenicity.  

PubMed

As locomotive organelles, flagella allow bacteria to move toward favorable environments. A flagellum consists of three parts: the basal structure (rotary motor), the hook (universal joint), and the filament (helical propeller). For ages, flagella have been generally regarded as important virulence factors, mainly because of their motility property. However, flagella are getting recognized to play multiple roles with more functions besides motility and chemotaxis. Recent evidence has pinpointed that the bacterial flagella participate in many additional processes including adhesion, biofilm formation, virulence factor secretion, and modulation of the immune system of eukaryotic cells. This mini-review summarizes data from recent studies that elucidated how flagella, as a virulence factor, contribute to bacterial pathogenicity. PMID:22359233

Duan, Qiangde; Zhou, Mingxu; Zhu, Liqian; Zhu, Guoqiang

2012-02-23

147

Universality in Bacterial Colonies  

Microsoft Academic Search

The emergent spatial patterns generated by growing bacterial colonies have been the focus of intense study in physics during\\u000a the last twenty years. Both experimental and theoretical investigations have made possible a clear qualitative picture of\\u000a the different structures that such colonies can exhibit, depending on the medium on which they are growing. However, there\\u000a are relatively few quantitative descriptions

Juan A. Bonachela; Carey D. Nadell; Joăo B. Xavier; Simon A. Levin

2011-01-01

148

Tails of Bacterial Motility  

NASA Astrophysics Data System (ADS)

The cytoplasm of living cells provides a complex fluid environment in which intracellular bacteria live and move. By analyzing the easily visible curved actin ``comet-tail'' of polymerization-based-motility bacteria such as Listeria monocytogenes, we can learn about sub-micron structure and dynamics of the tail and of the bacterial surface enzyme that catalyzes tail formation. By characterizing the motility, we can transform such motile systems into probes of the cytoplasmic environment.

Rutenberg, Andrew; Grant, Martin

2001-03-01

149

Acute Bacterial Prostatitis  

Microsoft Academic Search

\\u000a Acute bacterial prostatitis (NIH category I) is diagnosed clinically and from urine culture. It can be a serious infection,\\u000a usually caused by uropathogens, with intense local pain, fever and other systemic symptoms. Prostatic massage is contrain-dicated,\\u000a microbiological diagnosis is usually performed by the midstream urine.\\u000a \\u000a \\u000a Antimicrobial therapy is the most essential part of the therapeutic regimen. Treatment varies according to

Kurt G. Naber; Florian M. E. Wagenlehner; Wolfgang Weidner

150

Bacterial Stress Sensors  

Microsoft Academic Search

Bacterial cells have limited abilities to modify and choose their dynamic environment. They utilize information processing\\u000a systems to monitor their surroundings constantly for important changes. Among the appropriate responses to environmental changes\\u000a are alterations in physiology, development, virulence, and location. In most species, highly sophisticated global regulatory\\u000a networks modulate the expression of genes. These effects are mediated in large part

Wolfgang Schumann

151

[Family ideology].  

PubMed

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

Kornblit, A

1982-06-01

152

Conserved sequence motifs among bacterial, eukaryotic, and archaeal phosphatases that define a new phosphohydrolase superfamily.  

PubMed Central

Members of a new molecular family of bacterial nonspecific acid phosphatases (NSAPs), indicated as class C, were found to share significant sequence similarities to bacterial class B NSAPs and to some plant acid phosphatases, representing the first example of a family of bacterial NSAPs that has a relatively close eukaryotic counterpart. Despite the lack of an overall similarity, conserved sequence motifs were also identified among the above enzyme families (class B and class C bacterial NSAPs, and related plant phosphatases) and several other families of phosphohydrolases, including bacterial phosphoglycolate phosphatases, histidinol-phosphatase domains of the bacterial bifunctional enzymes imidazole-glycerolphosphate dehydratases, and bacterial, eukaryotic, and archaeal phosphoserine phosphatases and threalose-6-phosphatases. These conserved motifs are clustered within two domains, separated by a variable spacer region, according to the pattern [FILMAVT]-D-[ILFRMVY]-D-[GSNDE]-[TV]-[ILVAM]-[AT S VILMC]-X-żYFWHKR)-X-żYFWHNQż-X( 102,191)-żKRHNQż-G-D-żFYWHILVMCż-żQNHż-żFWYGPż-D -żPSNQYWż. The dephosphorylating activity common to all these proteins supports the definition of this phosphatase motif and the inclusion of these enzymes into a superfamily of phosphohydrolases that we propose to indicate as "DDDD" after the presence of the four invariant aspartate residues. Database searches retrieved various hypothetical proteins of unknown function containing this or similar motifs, for which a phosphohydrolase activity could be hypothesized.

Thaller, M. C.; Schippa, S.; Rossolini, G. M.

1998-01-01

153

Family Therapy  

MedlinePLUS

... your son or other family members erupt into arguments and you're left feeling frustrated and angry. ... Your e-mail Clicking "send" signifies that you have read and agree to our privacy policy. Share ...

154

Family Issues  

MedlinePLUS

... the challenges of autism and provides a safe, inclusive environment for both the child and family (see ... the lives of all affected by autism through education, advocacy, services, research and support.

155

Family Life  

MedlinePLUS

... partner and feel sad and frustrated by your limitations. Both people in your relationship may benefit from ... friends, family members, or professionals. Talking openly about limitations and brainstorming possible solutions will help both of ...

156

Family History  

MedlinePLUS

... found at http://www.usa.gov . Public Health Genomics Genomics About Us Weekly Update Genomics and Health Family Health History Genomic Testing EGAPP Implementation Reports and Publications Blog Podcasts ...

157

Importance of Family Routines  

MedlinePLUS

... Life > Family Dynamics > The Importance of Family Routines Family Life Listen The Importance of Family Routines Article Body Why are family routines so important to children? Every family needs ...

158

Normal Functioning Family  

MedlinePLUS

... Children > Family Life > Family Dynamics > Normal Functioning Family Family Life Listen Normal Functioning Family Article Body Is there any way to tell if my family is functioning normally? Many parents ask themselves this ...

159

Bacterial polyesters: biosynthesis, biodegradable plastics and biotechnology.  

PubMed

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

Lenz, Robert W; Marchessault, Robert H

160

[Taxonomic characteristics and physiological properties of microorganisms from the gut of pike (Esox lucius)].  

PubMed

The taxonomic composition and distribution of microorganisms differing in the degree of association with the intestinal mucosa of the pike (Lucius lucius) has been studied. Microorgansism of the families Enterobacteriaceae, Aeromonadaceae, and Vibrionaceae dominate in the gut microflora. Numerically prevailing bacterial species are characterized by high proteolytic and amylolytic enzyme activities as well as by high persistence accounted for by antilysozyme and antihistone activities. The results of this study show that Hafnia alvei, Yersinia ruckeri, Vibrio vulnificus, V. furnissii, Aeromonas salmonicida, and Shewanella putrefaciens may be regarded as normal components of the pike gut microflora. PMID:19198074

Izveskova, G I; Nemtseva, N V; Plotnikov, A O

161

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

PubMed

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

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

162

Interactions between model bacterial membranes and synthetic antimicrobials.  

NASA Astrophysics Data System (ADS)

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

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

2006-03-01

163

[Family therapy in polygamous families].  

PubMed

Patients from polygamous families are over-represented in the Enugu Psychiatric Hospital. The authors came to this conclusion after case notes from 116 anxiety neurotic, 101 schizophrenic and 117 depressive patients were examined. The patients were treated from 1970 to 1979. Polygamy was shortly described with its advantages and disadvantages. Competition between the wives, over-burdening of the husband and often poor care of the children represent the background for the symptoms of the patients, who come from such families. Looking for useful therapeutic methods the method of the natives to solve family quarrels were viewed. Making use of psychoanalytic therapy models especially as represented by Dührssen, Richter and Toman a family therapy model was presented which takes the native judgement model into consideration. A case was presented to illustrate the above. PMID:7234152

Ebigho, P O; Onyeama, W P; Ihezue, U H; Ahanotu, A C

164

Tropical bacterial gastrointestinal infections.  

PubMed

The bacterial gastrointestinal infections cholera, salmonellosis, shigellosis, campylobacteriosis, and diarrheagenic Escherichia coli are prevalent in tropical regions. These diseases impose an immense cost and contribute significantly to childhood morbidity and mortality. Management is hampered by limited access to diagnostic facilities and by antimicrobial drug resistance. Rapid point-of-care assays aim to reduce treatment delay and encourage rational use of antimicrobial agents. Control through safe drinking water, good sanitation, and vaccination against typhoid and cholera in high-risk populations is recommended. Vaccines against other Shigella and diarrheagenic E coli infections are under development. PMID:22632648

Shakoor, Sadia; Zaidi, Anita K M; Hasan, Rumina

2012-06-01

165

Bacterial expression and purification of active hematopoietic cell kinase.  

PubMed

Src family kinases (SFKs) are traditionally purified from eukaryotic expression systems. These expression systems can be costly, yield heterogeneously phosphorylated protein samples and present difficulties when metabolic labeling is required for structural studies. Therefore, many attempts have been made to develop bacterial purification systems for SFKs. So far, high-yield bacterial expression systems have only been achieved for SFK kinase domains or for inactive mutants of constructs containing the regulatory SH3 and SH2 domains, but not for their active forms. Herein described is a bacterial expression system for the wild type, active SFK Hck containing SH3, SH2 and kinase domains. Hck plays an important role in phagocyte function as well as the etiology of chronic myeloid leukemia as Hck is an interaction partner of Bcr-Abl. Structural studies of Hck are essential to fully understand the signaling processes involved in host defense and leukemogenesis. Successful bacterial expression of Hck was possible by a dual strategy: (1) co-expression with YopH phosphatase in order to control host toxicity, and (2) expression in a bacterial strain that is RNase E deficient, which dramatically increased overall expression levels. The expressed Hck construct is unphosphorylated and appears to be in an open conformation. Bacterially expressed Hck is capable of autophosphorylation, phosphorylates substrate at rates comparable to insect cell expressed Hck, and can be inhibited by staurosporine and Csk. PMID:21385611

Kristelly, Romana; Qiu, Theresa Wenli; Gunn, Natalie J; Scanlon, Denis B; Mulhern, Terrence D

2011-03-06

166

Family II. Leptospiraceae Hovind-Hougen 1979, 245AL  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

167

In an early branching metazoan, bacterial colonization of the embryo is controlled by maternal antimicrobial peptides  

PubMed Central

Early embryos of many organisms develop outside the mother and are immediately confronted with myriads of potential colonizers. How these naive developmental stages control and shape the bacterial colonization is largely unknown. Here we show that early embryonic stages of the basal metazoan Hydra are able to control bacterial colonization by using maternal antimicrobial peptides. Antimicrobial peptides of the periculin family selecting for a specific bacterial colonization during embryogenesis are produced in the oocyte and in early embryos. If overexpressed in hydra ectodermal epithelial cells, periculin1a drastically reduces the bacterial load, indicating potent antimicrobial activity. Unexpectedly, transgenic polyps also revealed that periculin, in addition to bactericidal activity, changes the structure of the bacterial community. These findings delineate a role for antimicrobial peptides both in selecting particular bacterial partners during development and as important components of a “be prepared” strategy providing transgenerational protection.

Fraune, Sebastian; Augustin, Rene; Anton-Erxleben, Friederike; Wittlieb, Jorg; Gelhaus, Christoph; Klimovich, Vladimir B.; Samoilovich, Marina P.; Bosch, Thomas C. G.

2010-01-01

168

In an early branching metazoan, bacterial colonization of the embryo is controlled by maternal antimicrobial peptides.  

PubMed

Early embryos of many organisms develop outside the mother and are immediately confronted with myriads of potential colonizers. How these naive developmental stages control and shape the bacterial colonization is largely unknown. Here we show that early embryonic stages of the basal metazoan Hydra are able to control bacterial colonization by using maternal antimicrobial peptides. Antimicrobial peptides of the periculin family selecting for a specific bacterial colonization during embryogenesis are produced in the oocyte and in early embryos. If overexpressed in hydra ectodermal epithelial cells, periculin1a drastically reduces the bacterial load, indicating potent antimicrobial activity. Unexpectedly, transgenic polyps also revealed that periculin, in addition to bactericidal activity, changes the structure of the bacterial community. These findings delineate a role for antimicrobial peptides both in selecting particular bacterial partners during development and as important components of a "be prepared" strategy providing transgenerational protection. PMID:20921390

Fraune, Sebastian; Augustin, René; Anton-Erxleben, Friederike; Wittlieb, Jörg; Gelhaus, Christoph; Klimovich, Vladimir B; Samoilovich, Marina P; Bosch, Thomas C G

2010-10-04

169

Animal Models of Bacterial Keratitis  

PubMed Central

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

Marquart, Mary E.

2011-01-01

170

Bacterial proteases and virulence.  

PubMed

Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing tolerance to adverse conditions such as those experienced in the host. In the membrane, HtrA performs similar functions whereas the extracellular proteases, in close contact with host components, pave the way for spreading infections by degrading host matrix components or interfering with host cell signalling to short-circuit host cell processes. Common to both intra- and extracellular proteases is the tight control of their proteolytic activities. In general, substrate recognition by the intracellular proteases is highly selective which is, in part, attributed to the chaperone activity associated with the proteases either encoded within the same polypeptide or on separate subunits. In contrast, substrate recognition by extracellular proteases is less selective and therefore these enzymes are generally expressed as zymogens to prevent premature proteolytic activity that would be detrimental to the cell. These extracellular proteases are activated in complex cascades involving auto-processing and proteolytic maturation. Thus, proteolysis has been adopted by bacterial pathogens at multiple levels to ensure the success of the pathogen in contact with the human host. PMID:23479441

Frees, Dorte; Brřndsted, Lone; Ingmer, Hanne

2013-01-01

171

Universality in Bacterial Colonies  

NASA Astrophysics Data System (ADS)

The emergent spatial patterns generated by growing bacterial colonies have been the focus of intense study in physics during the last twenty years. Both experimental and theoretical investigations have made possible a clear qualitative picture of the different structures that such colonies can exhibit, depending on the medium on which they are growing. However, there are relatively few quantitative descriptions of these patterns. In this paper, we use a mechanistically detailed simulation framework to measure the scaling exponents associated with the advancing fronts of bacterial colonies on hard agar substrata, aiming to discern the universality class to which the system belongs. We show that the universal behavior exhibited by the colonies can be much richer than previously reported, and we propose the possibility of up to four different sub-phases within the medium-to-high nutrient concentration regime. We hypothesize that the quenched disorder that characterizes one of these sub-phases is an emergent property of the growth and division of bacteria competing for limited space and nutrients.

Bonachela, Juan A.; Nadell, Carey D.; Xavier, Joăo B.; Levin, Simon A.

2011-07-01

172

Periodic growth of bacterial colonies  

NASA Astrophysics Data System (ADS)

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

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

2005-06-01

173

Family Foundations  

Microsoft Academic Search

A new program in California partners the California Department of Corrections with a non-profit drug treatment agency on behalf of pregnant or parenting women who are drug offenders with substance abuse histories. The women are sentenced to the family foundations facility for one year and receive a range of special services to prepare for community re-entry. This paper provides a

Brenda Wiewel; Toni Mosley

2006-01-01

174

Family Hypnotherapy.  

ERIC Educational Resources Information Center

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)

Araoz, Daniel L.; Negley-Parker, Esther

1985-01-01

175

Familial dysautonomia  

Microsoft Academic Search

Familial dysautonomia is a developmental disorder of the sensory and autonomic nervous system. Recent studies have shown that two mutations in the gene IKBKAP are responsible for the disease. IKAP, the IKBKAP-encoded protein, is a member of the recently identified human Elongator complex. The major FD mutation is a splice mutation that results in aberrant tissue-specific mRNA splicing.

Susan A Slaugenhaupt; James F Gusella

2002-01-01

176

Family Letters  

Microsoft Academic Search

:Falbel describes the process by which she and her brother and parents were saved from Austria on the eve of WWII through the determined efforts of an aunt and uncle in America, and subsequent failed attempts to obtain exit visas for her grandparents. Included are seven letters from among hundreds that were sent between family members in different countries, describing

Rita Falbel

2009-01-01

177

Family Letters  

Microsoft Academic Search

Falbel describes the process by which she and her brother and parents were saved from Austria on the eve of WWII through the determined efforts of an aunt and uncle in America, and subsequent failed attempts to obtain exit visas for her grandparents. Included are seven letters from among hundreds that were sent between family members in different countries, describing

Translated

2009-01-01

178

Family Violence.  

ERIC Educational Resources Information Center

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

Sorgen, Carol, Ed.

1979-01-01

179

My Family.  

ERIC Educational Resources Information Center

|This elementary reader is designed for use in a bilingual Inupiat-English program in Buckland and Deering, Alaska. It is the story of a small boy named Paul and his family. The Inupiat text and its English equivalent are never in opposition. The Inupiat text is presented on a picture page, with the English on the back. The illustrations, by J.…

Alaska State-Operated Schools, Anchorage.

180

Marine Bacterial Sialyltransferases  

PubMed Central

Sialyltransferases transfer N-acetylneuraminic acid (Neu5Ac) from the common donor substrate of these enzymes, cytidine 5?-monophospho-N-acetylneuraminic acid (CMP-Neu5Ac), to acceptor substrates. The enzymatic reaction products including sialyl-glycoproteins, sialyl-glycolipids and sialyl-oligosaccharides are important molecules in various biological and physiological processes, such as cell-cell recognition, cancer metastasis, and virus infection. Thus, sialyltransferases are thought to be important enzymes in the field of glycobiology. To date, many sialyltransferases and the genes encoding them have been obtained from various sources including mammalian, bacterial and viral sources. During the course of our research, we have detected over 20 bacteria that produce sialyltransferases. Many of the bacteria we isolated from marine environments are classified in the genus Photobacterium or the closely related genus Vibrio. The paper reviews the sialyltransferases obtained mainly from marine bacteria.

Yamamoto, Takeshi

2010-01-01

181

Control of bacterial spores.  

PubMed

Bacterial spores are much more resistant than their vegetative counterparts. The most dangerous spore-former is Clostridium botulinum which produces a potent neurotoxin that can prove fatal. The most common food poisoning from a spore-former is caused by C. perfringens. Other food poisoning spore-formers include Bacillus cereus, B. subtilis and B. licheniformis. There are a number of non-pathogenic spore-formers including butyric and thermophilic anaerobes that cause significant economic losses to food producers. Some unusual spoilage complaints have been reported, for example, B. sporothermodurans in UHT milk, Alicyclobacillus acidoterrestris in apple and orange juice and Desulfotomaculum nigrificans in hot vending machines. Control of spore-formers requires an understanding of both the resistance and outgrowth characteristics of the spores. PMID:10885113

Brown, K L

2000-01-01

182

Laboratory diagnosis of bacterial meningitis.  

PubMed Central

Bacterial meningitis is relatively common, can progress rapidly, and can result in death or permanent debilitation. This infection justifiably elicits strong emotional reactions and, hopefully, immediate medical intervention. This review is a brief presentation of the pathogenesis of bacterial meningitis and a review of current knowledge, literature, and recommendations on the subject of laboratory diagnosis of bacterial meningitis. Those who work in clinical microbiology laboratories should be familiar with the tests used in detecting bacteria and bacterial antigens in cerebrospinal fluid (CSF) and should always have the utmost appreciation for the fact that results of such tests must always be reported immediately. Academic and practical aspects of the laboratory diagnosis of bacterial meningitis presented in this review include the following: anatomy of the meninges; pathogenesis; changes in the composition of CSF; etiological agents; processing CSF; microscopic examination of CSF; culturing CSF; methods of detecting bacterial antigens and bacterial components in CSF (counter-immunoelectrophoresis, coagglutination, latex agglutination, enzyme-linked immunosorbent assay, Limulus amebocyte lysate assay, and gas-liquid chromatography); use of the polymerase chain reaction; and practical considerations for testing CSF for bacterial antigens.

Gray, L D; Fedorko, D P

1992-01-01

183

Acyltransferases in bacterial glycerophospholipid synthesis  

Microsoft Academic Search

Phospholipid biosynthesis is a vital facet of bac- terial physiology that begins with the synthesis of the fatty acids by a soluble type II fatty acid synthase. The bacterial glycerol-phosphate acyltransferases utilize the completed fatty acid chains to form the first membrane phospholipid and thus play a critical role in the regulation of membrane biogenesis. The first bacterial acyltransferase described

Yong-Mei Zhang; Charles O. Rock

184

Family Structure and Family Processes in Mexican American Families  

PubMed Central

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.

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

2010-01-01

185

Fluorescent sensor for bacterial recognition  

NASA Astrophysics Data System (ADS)

Boronic acid-based fluorescent sensor is one of the non-enzymatic methods used for the recognition of saccharides. Since bacterial membrane has polysaccharides with diol groups, boronic acids probe could be applied for rapid bacterial recognition. Escherichia coli (XL-1 blue) were recognized by applying (3-(5-(dimethylamino) naphthalene-1-sulfonamide) phenyl) boronic acid (DNSBA) as a sensor and the fluorescence recorded by fluorometer micro-plate reader. Results showed that, fluorescence records of DNSBA increase in a dose dependent manner upon increasing the bacterial cell numbers. Moreover, the increase in the number of bacterial cells induces a shift in the spectra due to the formation of the anionic form of boronic acid complex. Therefore, DNSBA is an efficient sensor for monitoring bacterial cells.

Amin, Rehab; Elfeky, Souad A.

2013-05-01

186

Formyl peptide receptors and the regulation of ACTH secretion: targets for annexin A1, lipoxins, and bacterial peptides  

Microsoft Academic Search

The N-formyl peptide receptors (FPRs) are a family of G-protein coupled receptors that re- spond to proinflammatory N-formylated bacterial pep- tides (e.g., formyl-Met-Leu-Phe, fMLF) and, thus, con- tribute to the host response to bacterial infection. Paradoxically, a growing body of evidence suggests that some members of this receptor family may also be targets for certain anti-inflammatory molecules, includ- ing annexin

C. D. John; V. Sahni; D. Mehet; J. F. Morris; H. C. Christian; M. Perretti; R. J. Flower; E. Solito; J. C. Buckingham

2007-01-01

187

Mob families and mad families  

Microsoft Academic Search

.   We show the consistency of where is the size of the smallest off-branch family, and is as usual the dominating number. We also prove the consistency of with large continuum. Here, is the unbounding number, and is the almost disjointness number.

Jörg Brendle

1998-01-01

188

Structural and functional diversity among bacterial interspersed mosaic elements (BIMEs).  

PubMed

Palindromic units (PU or REP) were defined as 40-nucleotide DNA sequences which are highly repeated in the genome of several members of the Enterobacteriaceae. They were shown to be a constituent of the bacterial interspersed mosaic element (BIME), in which they are associated with other repetitive sequences. We report here that Escherichia coli PU sequences contain three motifs (Y, Z1 and Z2), leading to the definition of two BIME families. The BIME-1 family, highly conserved over 145 nucleotides, contains two PUs (motifs Y and Z1). The BIME-2 family contains a variable number of PUs (motifs Y and Z2). We present evidence, using band shift experiments, that each PU motif binds DNA gyrase with a different affinity. This suggests that the two families are functionally distinct. PMID:8057840

Bachellier, S; Saurin, W; Perrin, D; Hofnung, M; Gilson, E

1994-04-01

189

A family of homologous substrate-binding proteins with a broad range of substrate specificity and dissimilar biological functions  

Microsoft Academic Search

The uptake of peptides is accomplished mainly by a family of homologous oligopeptide or dipeptide transporters in bacteria. Computer-aided sequence analyses expand members of the oligopeptide-binding protein family to nickel and heme permeases and other proteins, including an enzyme hyaluronate synthase. They are involved in human pathogenicity, bacterial virulence, substrate-sensing, bacterial conjugation and bacterial metabolic reactions distinct from nutrient uptake.

L. F. Wu; M. A. Mandrand-Berthelot

1995-01-01

190

Hirayama Family  

NASA Astrophysics Data System (ADS)

Any of several groups of asteroids each of whose members share similar orbital elements, in particular a closely similar semi-major axis and orbital inclination. These similarities are surmised to indicate that the members of a particular Hirayama family share a common origin in the collisional break-up of a large parent body. The existence of such groups were first pointed out by Kiyotsugu Hiray...

Murdin, P.

2000-11-01

191

Familial mesothelioma: a report of two families  

Microsoft Academic Search

Five reports of familial mesothelioma in which mesotheliomas occurred in two or more family members have been recorded in the medical literature. In this report, we describe two examples of familial mesothelioma. In one family, three brothers who worked in the asbestos insulation industry developed mesothelioma. In the second family, the father, who was occupationally exposed to asbestos, died from

Samuel P. Hammar; Dawn Bockus; Franque Remington; Susan Freidman; Gordon LaZerte

1989-01-01

192

Bacterial Communities of the Gorgonian Octocoral Pseudopterogorgia elisabethae.  

PubMed

Pseudopterogorgia elisabethae is a common inhabitant of Caribbean reefs and is a well-known source of diterpenes with diverse biological activities. Notably, this octocoral is the sole source of the pseudopterosin family of anti-inflammatory diterpenes and is harvested to supply commercial demand for these metabolites. We have characterized the composition of the bacterial community associated with P. elisabethae collected from Providencia Island, Colombia, using both culture-dependent and culture-independent approaches. Culture-independent analysis revealed that the bacterial communities were composed of eight phyla, of which Proteobacteria was the most abundant. At the class level, bacterial communities were dominated by Gammaproteobacteria (82-87 %). Additionally, operational taxonomic units related to Pseudomonas and Endozoicomonas species were the most abundant phylotypes consistently associated with P. elisabethae colonies. Culture-dependent analysis resulted in the identification of 40 distinct bacteria classified as Bacilli (15), Actinobacteria (12), Gammaproteobacteria (9), Alphaproteobacteria (3), and Betaproteobacteria (1). Only one of the 40 cultured bacteria was closely related to a dominant phylotype detected in the culture-independent study, suggesting that conventional culturing techniques failed to culture the majority of octocoral-associated bacterial diversity. To the best of our knowledge, this is the first characterization of the bacterial diversity associated with P. elisabethae. PMID:23913197

Correa, Hebelin; Haltli, Brad; Duque, Carmenza; Kerr, Russell

2013-08-04

193

Desert gerbils affect bacterial composition of soil.  

PubMed

Rodents affect soil microbial communities by burrow architecture, diet composition, and foraging behavior. We examined the effect of desert rodents on nitrogen-fixing bacteria (NFB) communities by identifying bacteria colony-forming units (CFU) and measuring nitrogen fixation rates (ARA), denitrification (DA), and CO2 emission in soil from burrows of three gerbil species differing in diets. Psammomys obesus is folivorous, Meriones crassus is omnivorous, consuming green vegetation and seeds, and Dipodillus dasyurus is predominantly granivorous. We also identified NFB in the digestive tract of each rodent species and in Atriplex halimus and Anabasis articulata, dominant plants at the study site. ARA rates of soil from burrows of the rodent species were similar, and substantially lower than control soil, but rates of DA and CO2 emission differed significantly among burrows. Highest rates of DA and CO2 emission were measured in D. dasyurus burrows and lowest in P. obesus. CFU differed among bacteria isolates, which reflected dietary selection. Strains of cellulolytic representatives of the family Myxococcaceae and the genus Cytophaga dominated burrows of P. obesus, while enteric Bacteroides dominated burrows of D. dasyurus. Burrows of M. crassus contained both cellulolytic and enteric bacteria. Using discriminant function analysis, differences were revealed among burrow soils of all rodent species and control soil, and the two axes accounted for 91 % of the variance in bacterial occurrences. Differences in digestive tract bacterial occurrences were found among these rodent species. Bacterial colonies in P. obesus and M. crassus burrows were related to bacteria of A. articulata, the main plant consumed by both species. In contrast, bacteria colonies in the burrow soil of D. dasyurus were related to bacteria in its digestive tract. We concluded that gerbils play an important role as ecosystem engineers within their burrow environment and affect the microbial complex of the nitrogen-fixing organisms in soils. PMID:23857378

Kuznetsova, Tatyana A; Kam, Michael; Khokhlova, Irina S; Kostina, Natalia V; Dobrovolskaya, Tatiana G; Umarov, Marat M; Degen, A Allan; Shenbrot, Georgy I; Krasnov, Boris R

2013-07-16

194

Bacterial infections other than spontaneous bacterial peritonitis in cirrhosis  

PubMed Central

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

Bunchorntavakul, Chalermrat; Chavalitdhamrong, Disaya

2012-01-01

195

Antimicrobials for bacterial bioterrorism agents.  

PubMed

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

Sarkar-Tyson, Mitali; Atkins, Helen S

2011-06-01

196

Neonatal bacterial meningitis.  

PubMed

Neonatal bacterial meningitis (NM) continues to be a serious disease with an unchanging rate of adverse outcome of 20-60%, despite a worldwide decline in mortality. The 3 major pathogens in developed countries are: Group B streptococcus, gram negative rods and Lysteria monocytogenes. Signs and symptoms of NM may be subtle, unspecific, vague, atypical or absent. In order to exclude NM, all infants with proven or suspected sepsis should undergo lumbar puncture. Positive culture of cerebrospinal fluid may be the only way to diagnose NM and to identify the pathogen, as CSF parameters Smay be normal at early stages and NM may occur frequently (up to 30% of cases) in the absence of bacteraemia. When NM is suspected, treatment must be aggressive, as the goal is to achieve bactericidal concentration of antibiotics and to sterilize CSF as soon as possible. Antibiotics should be administered intravenously, at the highest clinically validated doses. Empiric antibiotic treatment should include agents active against all main pathogens; currently the recommended empiric treatment of NM is ampicillin, plus an aminoglycoside and a third-generation cephalosporn. Therapy should be reassessed after cultures and antibiotic susceptibility is available. Prevention of neonatal sepsis, early recognition of infants at risk, prompt treatment and future adjunctive therapies will improve prognosis. Finally, we present the first preliminary Italian data on GBS meningitis. Data are obtained from an area-based study conducted In Emilia-Romagna during 2003 to 2009. PMID:21089719

Berardi, A; Lugli, L; Rossi, C; China, M C; Vellani, G; Contiero, R; Calanca, F; Camerlo, F; Casula, F; Di Carlo, C; Rossi, M R; Chiarabini, R; Ferrari, M; Minniti, S; Venturelli, C; Silvestrini, D; Dodi, I; Zucchini, A; Ferrari, F

2010-06-01

197

Bacterial RNA isolation.  

PubMed

In this bacterial RNA isolation protocol, an "RNA-protective" treatment is followed by lysozyme digestion of the peptidoglycan component of the cell wall. EDTA promotes the loss of the outer membrane of Gram-negative bacteria and allows the lysozyme better access to the peptidoglycan. Cells begin to lyse during digestion in hypotonic lysozyme buffer and lysis is completed by sodium dodecyl sulfate (SDS) and hot phenol:chloroform:isoamyl alcohol (PCA) extraction. SDS and hot phenol disrupt membranes, denature protein (including RNase), and strip proteins from RNA. The separation of the organic phase from the aqueous phase is achieved using Phase Lock Gel, an inert material with a density intermediate between the organic and aqueous samples. The sample is split into three phases: from bottom to top, these are phenol and chloroform (organic phase), the inert gel with the interface material, and the aqueous phase with the RNA. The gel acts as a physical barrier between the sample and the organic phase plus interface. Following organic extraction, the RNA is concentrated by ethanol precipitation. PMID:22949721

Ares, Manuel

2012-09-01

198

The Rare Bacterial Biosphere  

NASA Astrophysics Data System (ADS)

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.

Pedrós-Alió, Carlos

2012-01-01

199

Bacterial iron homeostasis.  

PubMed

Iron is essential to virtually all organisms, but poses problems of toxicity and poor solubility. Bacteria have evolved various mechanisms to counter the problems imposed by their iron dependence, allowing them to achieve effective iron homeostasis under a range of iron regimes. Highly efficient iron acquisition systems are used to scavenge iron from the environment under iron-restricted conditions. In many cases, this involves the secretion and internalisation of extracellular ferric chelators called siderophores. Ferrous iron can also be directly imported by the G protein-like transporter, FeoB. For pathogens, host-iron complexes (transferrin, lactoferrin, haem, haemoglobin) are directly used as iron sources. Bacterial iron storage proteins (ferritin, bacterioferritin) provide intracellular iron reserves for use when external supplies are restricted, and iron detoxification proteins (Dps) are employed to protect the chromosome from iron-induced free radical damage. There is evidence that bacteria control their iron requirements in response to iron availability by down-regulating the expression of iron proteins during iron-restricted growth. And finally, the expression of the iron homeostatic machinery is subject to iron-dependent global control ensuring that iron acquisition, storage and consumption are geared to iron availability and that intracellular levels of free iron do not reach toxic levels. PMID:12829269

Andrews, Simon C; Robinson, Andrea K; Rodríguez-Quińones, Francisco

2003-06-01

200

Sitafloxacin: in bacterial infections.  

PubMed

Sitafloxacin is a fluoroquinolone antibacterial with in vitro activity against a broad range of Gram-positive and -negative bacteria, including anaerobic bacteria, as well as against atypical pathogens. It is approved in Japan for use in a number of bacterial infections caused by sitafloxacin-susceptible strains of Staphylococcus spp., Streptococcus pneumoniae, other Streptococcus spp., Enterococcus spp., Moraxella catarrhalis, Escherichia coli, Citrobacter spp., Klebsiella spp., Enterobacter spp., Serratia spp., Proteus spp., Morganella morganii, Haemophilus influenzae, Pseudomonas aeruginosa, Legionella pneumophila, Peptostreptococcus spp., Prevotella spp., Porphyromonas spp., Fusobacterium spp., Chlamydia trachomatis, Chlamydophila pneumoniae and Mycoplasma pneumoniae. In terms of clinical efficacy, oral sitafloxacin was noninferior to oral levofloxacin in the treatment of community-acquired pneumonia or an infectious exacerbation of chronic respiratory tract disease, noninferior to oral tosufloxacin in the treatment of community-acquired pneumonia, and noninferior to oral levofloxacin in the treatment of complicated urinary tract infections, according to the results of randomized, double-blind, multicentre, noninferiority trials. Noncomparative studies demonstrated the efficacy of oral sitafloxacin in otorhinolaryngological infections, urethritis in men, C. trachomatis-associated cervicitis in women and odontogenic infections. Gastrointestinal disorders and laboratory abnormalities were the most commonly occurring adverse reactions in patients receiving oral sitafloxacin. Adverse reactions reported in sitafloxacin recipients in the active comparator trials were of mild to moderate severity. PMID:21504249

Keating, Gillian M

2011-04-16

201

The bacterial nucleoid revisited.  

PubMed Central

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

Robinow, C; Kellenberger, E

1994-01-01

202

Bacterial extracellular polysaccharides.  

PubMed

Extracellular polysaccharides are as structurally and functionally diverse as the bacteria that synthesise them. They can be present in many forms, including cell-bound capsular polysaccharides, unbound "slime", and as O-antigen component of lipopolysaccharide, with an equally wide range of biological functions. These include resistance to desiccation, protection against nonspecific and specific host immunity, and adherence. Unsurprisingly then, much effort has been made to catalogue the enormous structural complexity of the extracellular polysaccharides made possible by the wide assortment of available monosaccharide combinations, non-carbohydrate residues, and linkage types, and to elucidate their biosynthesis and export. In addition, the work is driven by the commercial potential of these microbial substances in food, pharmaceutics and biomedical industries. Most recently, bacteria-mediated environmental restoration and bioleaching have been attracting much attention owing to their potential to remediate environmental effluents produced by the mining and metallurgy industries. In spite of technological advances in chemistry, molecular biology and imaging techniques that allowed for considerable expansion of knowledge pertaining to the bacterial surface polysaccharides, current understanding of the mechanisms of synthesis and regulation of extracellular polysaccharides is yet to fully explain their structural intricacy and functional variability. PMID:21557066

Bazaka, Kateryna; Crawford, Russell J; Nazarenko, Evgeny L; Ivanova, Elena P

2011-01-01

203

A Phylogeny of Bacterial RNA Nucleotidyltransferases: Bacillus halodurans Contains Two tRNA Nucleotidyltransferases  

Microsoft Academic Search

We have analyzed the distribution of RNA nucleotidyltransferases from the family that includes poly(A) polymerases (PAP) and tRNA nucleotidyltransferases (TNT) in 43 bacterial species. Genes of several bacterial species encode only one member of the nucleotidyltransferase superfamily (NTSF), and if that protein func- tions as a TNT, those organisms may not contain a poly(A) polymerase I like that of Escherichia

Patricia Bralley; Samantha A. Chang; George H. Jones

2005-01-01

204

Novel anti-infection agents: small-molecule inhibitors of bacterial transcription factors.  

PubMed

Structure-based drug design was utilized to identify potent small-molecule inhibitors of proteins within the AraC family of bacterial transcription factors, which control virulence in medically important microbes. These agents represent a novel approach to fight infectious disease and may be less likely to promote resistance development. These compounds lack intrinsic antibacterial activity in vitro and were able to limit a bacterial infection in a mouse model of urinary tract infection. PMID:17766109

Bowser, Todd E; Bartlett, Victoria J; Grier, Mark C; Verma, Atul K; Warchol, Taduesz; Levy, Stuart B; Alekshun, Michael N

2007-08-21

205

Military Families Considering Adoption  

MedlinePLUS

... Centered Casework Practice Family Group Decision-Making Engaging Communities to Support Families Creating a Family-Centered Agency Culture Child Abuse & Neglect Child Abuse & Neglect Home Overview ...

206

Bacterial pathogen evolution: breaking news.  

PubMed

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

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

2010-11-01

207

Bacterial Degradation of Polychlorinated Biphenyls  

Microsoft Academic Search

\\u000a Microbe bioremediation is the application of biological treatment to the cleanup of hazardous contaminants in soil and surface\\u000a or subsurface waters. Normally microbe bioremediation treats organic contaminants. Most microbe bioremediation processes take\\u000a advantage of indigenous microorganisms, although some rely on the introduction of bacterial or fungal strains. Bacterial digestion\\u000a is the process of bacteria-consuming organic matter. The bacteria feed on

Martina Mackova; Ondrej Uhlik; Petra Lovecka; Jitka Viktorova; Martina Novakova; Katerina Demnerova; Michel Sylvestre; Tomas Macek

208

Bacterial Endophthalmitis Following Cataract Surgery  

Microsoft Academic Search

Cataracts are the most common cause of blindness in the world and cataract surgery is one of the most common surgical procedures\\u000a performed. During surgery the opacified crystalline lens is removed and replaced with a lens implant. Bacterial infection\\u000a of the internal eye (bacterial endophthalmitis) following cataract surgery appears to have increased since the 1990s. The\\u000a infection is the result

M. E. Zegans; C. M. Toutain-Kidd; M. S. Gilmore

209

Modelling bacterial speciation  

PubMed Central

A central problem in understanding bacterial speciation is how clusters of closely related strains emerge and persist in the face of recombination. We use a neutral Fisher–Wright model in which genotypes, defined by the alleles at 140 house-keeping loci, change in each generation by mutation or recombination, and examine conditions in which an initially uniform population gives rise to resolved clusters. Where recombination occurs at equal frequency between all members of the population, we observe a transition between clonal structure and sexual structure as the rate of recombination increases. In the clonal situation, clearly resolved clusters are regularly formed, break up or go extinct. In the sexual situation, the formation of distinct clusters is prevented by the cohesive force of recombination. Where the rate of recombination is a declining log-linear function of the genetic distance between the donor and recipient strain, distinct clusters emerge even with high rates of recombination. These clusters arise in the absence of selection, and have many of the properties of species, with high recombination rates and thus sexual cohesion within clusters and low rates between clusters. Distance-scaled recombination can thus lead to a population splitting into distinct genotypic clusters, a process that mimics sympatric speciation. However, empirical estimates of the relationship between sequence divergence and recombination rate indicate that the decline in recombination is an insufficiently steep function of genetic distance to generate species in nature under neutral drift, and thus that other mechanisms should be invoked to explain speciation in the presence of recombination.

Hanage, William P; Spratt, Brian G; Turner, Katherine M.E; Fraser, Christophe

2006-01-01

210

A role for glycosylated Serine-rich repeatproteins in Gram-positive bacterial pathogenesis  

PubMed Central

Summary Bacterial attachment to host surfaces is a pivotal event in the biological and infectious processes of both commensal and pathogenic bacteria, respectively. Serine-rich Repeat Proteins (SRRPs) are a family of adhesins in Gram-Positive bacteria that mediate attachment to a variety of host and bacterial surfaces. As such, they contribute towards a wide-range of diseases including sub-acute bacterial endocarditis, community-acquired pneumonia, and meningitis. SRRPs are unique in that they are glycosylated, require a non-canonical Sec-translocase for transport, and are largely composed of a domain containing hundreds of alternating serine residues. These serine-rich repeats are thought to extend a unique non-repeat (NR) domain outward away from the bacterial surface to mediate adhesion. Thus far, NR domains have been determined to bind to sialic acid moieties, keratins, or other NR domains of a similar SRRP. This review summarizes how this important family of bacterial adhesins mediates bacterial attachment to host and bacterial cells, contributes to disease pathogenesis, and might be targeted for pharmacological intervention or used as novel protective vaccine antigens. This review also highlights recent structural findings on the NR domains of these proteins.

Lizcano, Anel; Sanchez, Carlos J.; Orihuela, Carlos J.

2012-01-01

211

Family Support Program  

MedlinePLUS

... Families : Family Support Printer Friendly Send to friend Family Support Program If a child you love has ... launched our scholarship program in 2002 to assist families devastated by the cost of medical care to ...

212

Reclaiming Family Privilege  

ERIC Educational Resources Information Center

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

Seita, John

2012-01-01

213

New functions for the ancient DedA membrane protein family.  

PubMed

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

Doerrler, William T; Sikdar, Rakesh; Kumar, Sujeet; Boughner, Lisa A

2012-10-19

214

New Functions for the Ancient DedA Membrane Protein Family  

PubMed Central

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

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

2013-01-01

215

Gram-Negative Bacterial Sensors for Eukaryotic Signal Molecules  

PubMed Central

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.

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

2009-01-01

216

The evolutionary origins of detoxifying enzymes: the mammalian serum paraoxonases (PONs) relate to bacterial homoserine lactonases.  

PubMed

Serum paraoxonases (PONs) are detoxifying lactonases that were first identified in mammals. Three mammalian families are known, PON1, 2, and 3 that reside primarily in the liver. They catalyze essentially the same reaction, lactone hydrolysis, but differ in their substrate specificity. Although some members are highly specific, others have a broad specificity profile. The evolutionary origins and substrate specificities of PONs therefore remain poorly understood. Here, we report a newly identified family of bacterial PONs, and the reconstruction of the ancestor of the three families of mammalian PONs. Both the mammalian ancestor and the characterized bacterial PONX_OCCAL were found to efficiently hydrolyze N-acyl homoserine lactones that mediate quorum sensing in many bacteria, including pathogenic ones. The mammalian PONs may therefore relate to a newly identified family of bacterial, PON-like "quorum-quenching" lactonases. The appearance of PONs in metazoa is likely to relate to innate immunity rather than detoxification. Unlike the bacterial PON, the mammalian ancestor also hydrolyzes, with low efficiency, lactones other than homoserine lactones, thus preceding the detoxifying functions that diverged later in two of the three mammalian families. The bifunctionality of the mammalian ancestor and the trade-off between the quorum-quenching and detoxifying lactonase activities explain the broad and overlapping specificities of some mammalian PONs versus the singular specificity of others. PMID:23788644

Bar-Rogovsky, Hagit; Hugenmatter, Adrian; Tawfik, Dan S

2013-06-20

217

Effects of family connection and family individuation  

Microsoft Academic Search

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

Linda G. Bell; David C. Bell

2009-01-01

218

Taxonomy of bacterial fish pathogens  

PubMed Central

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.

2011-01-01

219

Pathogenicity Islands in Bacterial Pathogenesis  

PubMed Central

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

Schmidt, Herbert; Hensel, Michael

2004-01-01

220

Bacterially mediated mineralization of vaterite  

NASA Astrophysics Data System (ADS)

Myxococcus xanthus, a common soil bacterium, plays an active role in the formation of spheroidal vaterite. Bacterial production of CO 2 and NH 3 and the transformation of the NH 3 to NH4+ and OH -, thus increasing solution pH and carbonate alkalinity, set the physicochemical conditions (high supersaturation) leading to vaterite precipitation in the microenvironment around cells, and directly onto the surface of bacterial cells. In the latter case, fossilization of bacteria occurs. Vaterite crystals formed by aggregation of oriented nanocrystals with c-axis normal to the bacterial cell-wall, or to the core of the spherulite when bacteria were not encapsulated. While preferred orientation of vaterite c-axis appears to be determined by electrostatic affinity (ionotropic effect) between vaterite crystal (0001) planes and the negatively charged functional groups of organic molecules on the bacterium cell-wall or on extracellular polymeric substances (EPS), analysis of the changes in the culture medium chemistry as well as high resolution transmission electron microscopy (HRTEM) observations point to polymorph selection by physicochemical (kinetic) factors (high supersaturation) and stabilization by organics, both connected with bacterial activity. The latter is in agreement with inorganic precipitation of vaterite induced by NH 3 and CO 2 addition in the protein-rich sterile culture medium. Our results as well as recent studies on vaterite precipitation in the presence of different types of bacteria suggest that bacterially mediated vaterite precipitation is not strain-specific, and could be more common than previously thought.

Rodriguez-Navarro, Carlos; Jimenez-Lopez, Concepcion; Rodriguez-Navarro, Alejandro; Gonzalez-Muńoz, Maria Teresa; Rodriguez-Gallego, Manuel

2007-03-01

221

Bacterial penetration of restored cavities.  

PubMed

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

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

2001-03-01

222

New Treatments for Bacterial Keratitis  

PubMed Central

Purpose. To review the newer treatments for bacterial keratitis. Data Sources. PubMed literature search up to April 2012. Study Selection. Key words used for literature search: “infectious keratitis”, “microbial keratitis”, “infective keratitis”, “new treatments for infectious keratitis”, “fourth generation fluoroquinolones”, “moxifloxacin”, “gatifloxacin”, “collagen cross-linking”, and “photodynamic therapy”. Data Extraction. Over 2400 articles were retrieved. Large scale studies or publications at more recent dates were selected. Data Synthesis. Broad spectrum antibiotics have been the main stay of treatment for bacterial keratitis but with the emergence of bacterial resistance; there is a need for newer antimicrobial agents and treatment methods. Fourth-generation fluoroquinolones and corneal collagen cross-linking are amongst the new treatments. In vitro studies and prospective clinical trials have shown that fourth-generation fluoroquinolones are better than the older generation fluoroquinolones and are as potent as combined fortified antibiotics against common pathogens that cause bacterial keratitis. Collagen cross-linking was shown to improve healing of infectious corneal ulcer in treatment-resistant cases or as an adjunct to antibiotics treatment. Conclusion. Fourth-generation fluoroquinolones are good alternatives to standard treatment of bacterial keratitis using combined fortified topical antibiotics. Collagen cross-linking may be considered in treatment-resistant infectious keratitis or as an adjunct to antibiotics therapy.

Wong, Raymond L. M.; Gangwani, R. A.; Yu, Lester W. H.; Lai, Jimmy S. M.

2012-01-01

223

NLRP3 Inflammasome and Host Protection against Bacterial Infection  

PubMed Central

The inflammasome is a multi-protein complex that induces maturation of inflammatory cytokines interleukin (IL)-1? and IL-18 through activation of caspase-1. Several nucleotide binding oligomerization domain-like receptor family members, including NLRP3, recognize unique microbial and danger components and play a central role in inflammasome activation. The NLRP3 inflammasome is critical for maintenance of homeostasis against pathogenic infections. However, inflammasome activation acts as a double-edged sword for various bacterial infections. When the IL-1 family of cytokines is secreted excessively, they cause tissue damage and extensive inflammatory responses that are potentially hazardous for the host. Emerging evidence has shown that diverse bacterial pathogens or their components negatively regulate inflammasome activation to escape the immune response. In this review, we discuss the current knowledge of the roles and regulation of the NLRP3 inflammasome during bacterial infections. Activation and regulation of the NLRP3 inflammasome should be tightly controlled to prevent virulence and pathology during infections. Understanding the roles and regulatory mechanisms of the NLRP3 inflammasome is essential for developing potential treatment approaches against pathogenic infections.

Kim, Jwa-Jin

2013-01-01

224

Familial hypercholesterolaemia.  

PubMed

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

Marais, A David

2004-02-01

225

Abdominal radiation causes bacterial translocation  

SciTech Connect

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

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

1989-02-01

226

CHEMICAL STUDIES ON BACTERIAL AGGLUTINATION  

PubMed Central

1. By the application of an absolute, quantitative microchemical method for the estimation of agglutinins, precise data have been obtained on the course of the agglutination of Type I pneumococcus by homologous anticarbohydrate. 2. Within the limitations imposed by the necessity for the agglutination reaction to take place at the bacterial surface, the reaction is shown to be analogous to the precipitin reaction and subject to the same laws. 3. The entire process of a typical instance of specific bacterial agglutination has been quantitatively accounted for on a purely chemical basis and expressed in the form of equations derived from the law of mass action. 4. Experimental verification of predictions based on the theory has shown a fundamental difference between this instance of specific bacterial agglutination and the commonly adduced analogies, and necessitated a revision of current conceptions regarding the rôle of electrolytes and of physical forces in the reaction.

Heidelberger, Michael; Kabat, Elvin A.

1937-01-01

227

Curved microchannels and bacterial streamers  

NASA Astrophysics Data System (ADS)

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 nutrients and retention of suspended particles. In this talk, we present an experimental study of bacterial biofilm development in a microfluidic device. In particular, we show the formation of filamentous structures, or streamers, in curved channels and how these suspended biofilms are linked to the underlying hydrodynamics.

Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

2010-03-01

228

Autophagy and bacterial infectious diseases  

PubMed Central

Autophagy is a housekeeping process that maintains cellular homeostasis through recycling of nutrients and degradation of damaged or aged cytoplasmic constituents. Over the past several years, accumulating evidence has suggested that autophagy can function as an intracellular innate defense pathway in response to infection with a variety of bacteria and viruses. Autophagy plays a role as a specialized immunologic effector and regulates innate immunity to exert antimicrobial defense mechanisms. Numerous bacterial pathogens have developed the ability to invade host cells or to subvert host autophagy to establish a persistent infection. In this review, we have summarized the recent advances in our understanding of the interaction between antibacterial autophagy (xenophagy) and different bacterial pathogens.

Yuk, Jae-Min; Yoshimori, Tamotsu

2012-01-01

229

Family and family therapy in Russia.  

PubMed

This article represents the information about family and family therapy in the context of culture, traditions and contemporary changes of social situations in Russia. The legislation of family rights are mentioned within items about marriage and family in the Constitution, Civil Code and Family Code of the Russian Federation which has changed during recent years. The definition of family and description of family structure are given through the prism of the current demographic situation, dynamics of statistics of marriage and divorce rates, mental disorders, disabilities and such phenomena as social abandonment. The actual curriculum, teaching of family therapy and its disadvantages, system of continuous education, supervision and initiatives of the Institute of Integrative Family Therapy in improvement of preparing of specialists who can provide qualified psychosocial assistance for the family according to the actual needs of society are noted. The directions of state and private practice of family counselling and therapy both for psychiatric patients and medical patients, for adults and children in a family systemic approach are highlighted with an indication of the spectrum of techniques and methods used by Russian professionals. The main obstacles and perspectives of development of family therapy in Russia are summarized. PMID:22515460

Bebtschuk, Marina; Smirnova, Daria; Khayretdinov, Oleg

2012-04-01

230

Bacteriocin-Mediated Competitive Interactions of Bacterial Populations and Communities  

NASA Astrophysics Data System (ADS)

Explaining the coexistence of competing species is a major challenge in community ecology. In bacterial systems, competition is often driven by the production of bacteriocins; narrow spectrum proteinaceous toxins that serve to kill closely related species providing the producer better access to limited resources. Bacteriocin producers have been shown to competitively exclude sensitive, nonproducing strains. However, the interaction dynamics between bacteriocin producers, each lethal to its competitor, are largely unknown. Several recent studies have revealed some of the complexity of these interactions, employing a suite of in vitro, in vivo, and in silico bacterial model systems. This chapter describes the current state of knowledge regarding the population and community ecology of this potent family of toxins.

Riley, Margaret A.

231

Development of aminoglycoside antibiotics effective against resistant bacterial strains.  

PubMed

Aminoglycosides are important broad-spectrum antibiotics used in the therapy of many microbial infections. As the bacterial resistance to antibiotic therapy is appearing as an increasingly significant threat to public health, the development of aminoglycoside antibiotics with extended antibacterial spectrum and potency, devoid of nephro- and ototoxicity, and evading the resistance process returns to the focus of researchers. In this review, various developments brought to the aminoglycoside family of antibiotics effective against resistant bacteria have been described, focused on chemical modifications, drug-modifying enzyme inhibitors, and conformationally constrained analogs, as well as related antibacterial compounds, with the hope to provide information useful in rational design of novel antibiotics addressing bacterial resistance, and paving the way for new perspectives in antimicrobial therapy. PMID:20615188

Yang, Lin; Ye, Xin-Shan

2010-01-01

232

Structure and function of bacterial dynamin-like proteins.  

PubMed

Membrane dynamics are essential for numerous cellular processes in eukaryotic and prokaryotic cells. In eukaryotic cells, membrane fusion and fission are often catalyzed by large GTPases of the dynamin protein family. These proteins couple GTP hydrolysis to membrane deformation, which eventually leads to fusion or fission of the lipid bilayer. Mutations in eukaryotic dynamin-like proteins (DLPs) are associated with various diseases underscoring the importance to fully understand the biochemistry of these proteins. In recent years, a wealth of structural and biochemical data have been published that allow a detailed analysis of how dynamins or DLPs modulate biological membranes. However, less is known about the function of bacterial DLPs, although structural data exist. This review summarizes current knowledge about bacterial dynamins and discusses structural and functional properties in comparison to their eukaryotic counterparts. PMID:23109540

Bramkamp, Marc

2012-11-01

233

Family Literacy and ESL.  

ERIC Educational Resources Information Center

|Discusses family literacy and English as a Second Language, focusing on types of family literacy programs, issues in family literacy, and future directions in family literacy. Highlights one program and lists the components of three approaches to family literacy: intervention prevention, multiple literacies, and social change. (Author/VWL)|

Red, David L.

2003-01-01

234

Family Reading Night  

ERIC Educational Resources Information Center

|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…

Hutchins, Darcy; Greenfeld, Marsha; Epstein, Joyce

2007-01-01

235

Family Reading Night  

ERIC Educational Resources Information Center

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…

Hutchins, Darcy; Greenfeld, Marsha; Epstein, Joyce

2007-01-01

236

Family Homicide in  

Microsoft Academic Search

The family is viewed by most people as providing a nurturing and loving environment. But for some, the family environment can be deadly. In Australia, almost two in five homicides occur between family members, with an average of 129 family homicides each year. The majority of family homicides occur between intimate partners (60 per cent), and three-quarters of intimate partner

Australia Jenny Mouzos; Catherine Rushforth; Adam Graycar

237

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

Microsoft Academic Search

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

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

2003-01-01

238

Family Preservation (Family Focus Research Project).  

National Technical Information Service (NTIS)

The Family Focus Research project provided a comprehensive evaluation of home-based crisis intervention strategies for families with children at risk of placement into substitute care. It examined the relative costs and benefits of three types of brief, i...

J. R. Taplin C. Rowland

1983-01-01

239

Multiple Forms of Bacterial Hydrogenases  

PubMed Central

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

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

1966-01-01

240

Bacterial diversity across individual lichens.  

PubMed

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

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

2011-04-29

241

Bacterial Degradation of Vegetable Oils  

Microsoft Academic Search

Following initial experiments presented elsewhere (2IOPS), the bacterial degradation of two vegetable oils was investigated in some detail. the number of aerobic and anaerobic heterotrophic bacteria, oil degrading and sulphate reducing bacteria were quantified during simulated spills on a salt marsh. the sediment fatty acid composition was also studied using GC-MS analysis. Degradation of linseed and sunflower oils was concomitant

M. Gloria Pereira; Stephen M. Mudge; John Latchford

1998-01-01

242

Bacterial degradation of bile salts.  

PubMed

Bile salts are surface-active steroid compounds. Their main physiological function is aiding the digestion of lipophilic nutrients in intestinal tracts of vertebrates. Many bacteria are capable of transforming and degrading bile salts in the digestive tract and in the environment. Bacterial bile salt transformation and degradation is of high ecological relevance and also essential for the biotechnological production of steroid drugs. While biotechnological aspects have been reviewed many times, the physiological, biochemical and genetic aspects of bacterial bile salt transformation have been neglected. This review provides an overview of the reaction sequence of bile salt degradation and on the respective enzymes and genes exemplified with the degradation pathway of the bile salt cholate. The physiological adaptations for coping with the toxic effects of bile salts, recent biotechnological applications and ecological aspects of bacterial bile salt metabolism are also addressed. As the pathway for bile salt degradation merges with metabolic pathways for bacterial transformation of other steroids, such as testosterone and cholesterol, this review provides helpful background information for metabolic engineering of steroid-transforming bacteria in general. PMID:21088832

Philipp, Bodo

2010-11-19

243

Immunization by a bacterial aerosol  

Microsoft Academic Search

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

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

2008-01-01

244

Diversity of bacterial polyhydroxyalkanoic acids  

Microsoft Academic Search

An overview is provided on the diversity of biosynthetic polyhydroxyalkanoic acids, and all hitherto known constituents of these microbial storage compounds are listed. The occurrence of 91 different hydroxyalkanoic acids reflects the low substrate specificity of polyhydroxyalkanoic acid synthases which are the key enzymes of polyhydroxyalkanoic acid biosynthesis. In addition, the importance of bacterial anabolism and catabolism, which provide the

Alexander Steinbüchel; Henry E. Valentin

1995-01-01

245

Bacterial Diversity across Individual Lichens? †  

PubMed Central

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.

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

2011-01-01

246

Bacterial endospores the ultimate survivors  

Microsoft Academic Search

Bacterial endospores are the most resistant living structures, known. Their high degree of resistance to many treatments (including heat and UV) is due to many factors and is governed by the unique spore structure. Spore core dehydration is a primary determinant of heat resistance. A specialised cell wall peptidoglycan layer, termed the cortex maintains dehydration. During germination the spore cortex

Abdelmadjid Atrih; Simon J Foster

2002-01-01

247

Computer Simulation of Bacterial Cultures  

Microsoft Academic Search

A method is described for the simulation of bacterial biochemical taxonomic data with randomly inserted variations from typical reactions. This method is applied to data from a group of Enterobacterhceae. The simulated data thus generated show good agreement with expected results. The procedure will be useful in evaluating identification algorithms and in analysis of patterns of variation among bacteria. In

WILLIAM D. YOUNG

1975-01-01

248

Na + -driven bacterial flagellar motors  

Microsoft Academic Search

Bacterial flagellar motors are the reversible rotary engine which propels the cell by rotating a helical flagellar filament as a screw propeller. The motors are embedded in the cytoplasmic membrane, and the energy for rotation is supplied by the electrochemical potential of specific ions across the membrane. Thus, the analysis of motor rotation at the molecular level is linked to

Yasuo Imae; Tatsuo Atsumi

1989-01-01

249

Bacterial toxins and Multiple Sclerosis  

Microsoft Academic Search

The primary pathogenetic mechanism responsible for the distinctive demyelinating lesions in the Central Nervous System (CNS) in Multiple Sclerosis (MS), first described in remarkable detail by Charcot more than 170 years ago, remains one of the most baffling conundrums in medicine. A possible role for bacterial cell molecules and transportable proteins in the pathogenesis of MS is reviewed. The ability

Frederick Gay

2007-01-01

250

Bacterial endocarditis complicating body art  

Microsoft Academic Search

Increasing numbers of patients are living with congenital heart disease at a time when body art is growing in popularity. We present a case of subacute bacterial endocarditis following repeated tattooing in a patient with known valvular heart disease. This case highlights the importance of education of patients with structural heart disease to the potential risks of such procedures, particularly

Donald Tse; Sadia Khan; Sarah Clarke

2009-01-01

251

Bacterial Degradation of Nicotinic Acid  

Microsoft Academic Search

A BACTERIUM utilizing nicotinic acid was isolated from culture media made up of a solution of nicotinic acid and dilute sodium sulphide and inoculated with a small amount of Potomac mud. After allowing the bacteria to grow anaerobically, several successive transfers were made into a medium containing nicotinic acid, peptone, yeast extract, metals, phosphate and sodium sulphide. The mixed bacterial

Isaac Harary

1956-01-01

252

Bacterial discrimination: Dictyostelium's discerning taste.  

PubMed

New research indicates that the social amoeba Dictyostelium discoideum recognizes distinctions between Gram(-) and Gram(+) bacterial prey and responds discriminately to these two groups of bacteria. These findings may lend insight to the origins of microbial pattern recognition in innate immunity. PMID:23701686

Snyder, Michelle L D

2013-05-20

253

Bacterial ureases in infectious diseases  

Microsoft Academic Search

Ureases are multi-subunit, nickel-containing enzymes that catalyze the hydrolysis of urea to carbon dioxide and ammonia. This brief review discusses the biochemistry and genetics of bacterial ureases and outlines the roles of urea metabolism in microbial ecology and pathogenesis of some of the principle ureolytic species affecting human health.

Robert A Burne; Yi-Ywan M Chen

2000-01-01

254

Development of an engineered ‘bioluminescent’ reporter phage for the detection of bacterial blight of crucifers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Bacterial blight, caused by the phytopathogen Pseudomonas cannabina pv. alisalensis, is an emerging disease afflicting important members of the Brassica family. The disease is often misdiagnosed as peppery leaf spot, a much less severe disease caused by the closely related pathogen Pseudomonas syrin...

255

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

Microsoft Academic Search

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

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

256

A polyketide synthase-peptide synthetase gene cluster from an uncultured bacterial symbiont of Paederus beetles  

Microsoft Academic Search

Many drug candidates from marine and terrestrial invertebrates are suspected metabolites of uncultured bacterial symbionts. The antitumor polyketides of the pederin family, isolated from beetles and sponges, are an example. Drug development from such sources is commonly hampered by low yields and the difficulty of sustaining invertebrate cultures. To obtain insight into the true producer and find alternative supplies of

Jörn Piel

2002-01-01

257

Bacterial intermediate filaments: in vivo assembly, organization, and dynamics of crescentin  

Microsoft Academic Search

Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin also shares in vivo properties of assembly and dynamics with IF proteins by forming stable filamentous structures that continuously incorporate subunits

Godefroid Charbon; Matthew T. Cabeen; Christine Jacobs-Wagner

2009-01-01

258

Family Activities for Fitness  

ERIC Educational Resources Information Center

|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.|

Grosse, Susan J.

2009-01-01

259

Contacting My Donor Family  

MedlinePLUS

... My Donor Family Newsroom Minorities Contacting My Donor Family Writing anything can be a challenge. Staring at ... down to write a note to your donor family can feeling overwhelming. The good news is that ...

260

Annual Family Income  

Center for Drug Evaluation (CDER)

... Annual Family Income. Statistics. N. Valid. Missing. Total annual family income, 904, 0. Total annual family income. Frequency. Percent. ... More results from www.fda.gov/drugs/developmentapprovalprocess/developmentresources

261

Family Reunion Health Guide  

MedlinePLUS

... your reunion. 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. ...

262

NAIPs: building an innate immune barrier against bacterial pathogens. NAIPs function as sensors that initiate innate immunity by detection of bacterial proteins in the host cell cytosol.  

PubMed

The innate immune system of mammals encodes several families of immune detector proteins that monitor the cytosol for signs of pathogen invasion. One important but poorly understood family of cytosolic immunosurveillance proteins is the NLR (nucleotide-binding domain, leucine-rich repeat containing) proteins. Recent work has demonstrated that one subfamily of NLRs, the NAIPs (NLR family, apoptosis inhibitory proteins), are activated by specific interaction with bacterial ligands, such as flagellin. NAIP activation leads to assembly of a large multiprotein complex called the inflammasome, which initiates innate immune responses by activation of the Caspase-1 protease. NAIPs therefore appear to detect pathogen molecules via a simple and direct receptor-ligand mechanism. Interestingly, other NLR family members appear to detect pathogens indirectly, perhaps by responding to host cell "stress" caused by the pathogen. Thus, the NLR family may have evolved surprisingly diverse mechanisms for detecting pathogens. PMID:22513803

Kofoed, Eric M; Vance, Russell E

2012-04-19

263

A Cross-Taxon Analysis of Insect-Associated Bacterial Diversity  

PubMed Central

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.

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

2013-01-01

264

Bacterial Communities of Diverse Drosophila Species: Ecological Context of a Host-Microbe Model System  

PubMed Central

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

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

2011-01-01

265

Bacterial Destruction of Channel Catfish Eggs.  

National Technical Information Service (NTIS)

Studies have been underway at the laboratories of the Southeastern Cooperative Fish Disease Project of the Agricultural Experiment Station at Auburn University to investigate suspected bacterial infection of catfish eggs. The bacterial organisms of the ge...

J. H. Schachte

1973-01-01

266

Delayed infection, family size and malignant lymphomas  

PubMed Central

BACKGROUND—The annual incidence of non-Hodgkin's lymphomas (NHL) is increasing by 3%-4% in different parts of the developed world. Excesses of NHL have been observed in populations exposed to immunosuppressants and to HIV, but these causes do not explain the increasing trends. It is suggested that delayed infection could explain NHL trends, through an impairment of the Th1/Th2 lymphocyte patterns.?METHODS—In a population-based study on 1388 patients with NHL, 354 with Hodgkin's disease (HD) and 1718 healthy controls, the age of first occurrence of bacterial and viral diseases was investigated. Clinical records were perused in one centre to check the anamnestic data.?FINDINGS—The age of occurrence of bacterial and viral diseases was significantly higher among NHL patients than in the controls. The association between later age at first bacterial or viral disease was limited to small families (OR= 1.95; 95% confidence intervals 1.26, 3.00, for age 4-8 at first infection; OR=1.91; 1.19, 3.06, for age 9+, compared with less than 4). The association was more obvious for bacterial diseases (possibly for the lower degree of misclassification). High grade lymphomas showed the strongest association. The later age of occurrence of bacterial or viral diseases in NHL patients is consistent with a higher incidence of lymphomas observed in higher social groups. No clear association was found between HD and age at first bacterial or viral diseases.?INTERPRETATION—It is proposed that delayed infection could explain the increasing NHL trends, through an impairment of the Th1/Th2 lymphocyte patterns. The model of delayed infection has been proposed also to explain increasing prevalence rates of asthma.??

Vineis, P; Miligi, L; Crosignani, P; Fontana, A; Masala, G; Nanni, O; Ramazzotti, V; Rodella, S; Stagnaro, E; Tumino, R; Vigano, C; Vindigni, C; Costantini, A

2000-01-01

267

Familial mesothelioma: a report of two families  

SciTech Connect

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

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

1989-02-01

268

Family structure, family organization, and quality of family life  

Microsoft Academic Search

This study examines how family organization is associated with the quality of family life for parents in first marriages,\\u000a remarriages with biological children, and several types of stepfamilies. Data are drawn from the 1987–1988 National Survey\\u000a of Families and Households; only married couples in which both spouses participated in the survey and who had children under\\u000a age 19 in the

Patricia Voydanoff; Mark A. Fine; Brena W. Donnelly

1994-01-01

269

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

PubMed

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

Senderovich, Yigal; Halpern, Malka

2013-06-27

270

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

PubMed

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

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

2013-09-03

271

Effect of bacterial pyrogen on three lizard species.  

PubMed

1. Three lizard species (Callopistes maculatus, Gerrhosaurus major, and Varanus exanthematicus) were tested for their response to intraperitoneal injection of alcohol-killed Aeromonas sobria. 2. A paired experimental design, in which each animal received an injection of sterile saline and 1 x 10(10) A. sobria, was utilized. 3. C. maculatus demonstrated a statistically significant increase in mean selected body temperature (MSBT) after bacteria injection. 4. G. major and V. exanthematicus did not demonstrate a statistically significant increase in MSBT. 5. C. maculatus is the first lizard species outside of the family Iguanidae to exhibit a febrile response to bacterial pyrogen. PMID:1976479

Hallman, G M; Ortega, C E; Towner, M C; Muchlinski, A E

1990-01-01

272

Molecular target of synthetic antimicrobial oligomer in bacterial membranes  

NASA Astrophysics Data System (ADS)

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

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

2008-03-01

273

Structural Features of the Glutamate Transporter Family  

PubMed Central

Neuronal and glial glutamate transporters remove the excitatory neurotransmitter glutamate from the synaptic cleft and thus prevent neurotoxicity. The proteins belong to a large and widespread family of secondary transporters, including bacterial glutamate, serine, and C4-dicarboxylate transporters; mammalian neutral-amino-acid transporters; and an increasing number of bacterial, archaeal, and eukaryotic proteins that have not yet been functionally characterized. Sixty members of the glutamate transporter family were found in the databases on the basis of sequence homology. The amino acid sequences of the carriers have diverged enormously. Homology between the members of the family is most apparent in a stretch of approximately 150 residues in the C-terminal part of the proteins. This region contains four reasonably well-conserved sequence motifs, all of which have been suggested to be part of the translocation pore or substrate binding site. Phylogenetic analysis of the C-terminal stretch revealed the presence of five subfamilies with characterized members: (i) the eukaryotic glutamate transporters, (ii) the bacterial glutamate transporters, (iii) the eukaryotic neutral-amino-acid transporters, (iv) the bacterial C4-dicarboxylate transporters, and (v) the bacterial serine transporters. A number of other subfamilies that do not contain characterized members have been defined. In contrast to their amino acid sequences, the hydropathy profiles of the members of the family are extremely well conserved. Analysis of the hydropathy profiles has suggested that the glutamate transporters have a global structure that is unique among secondary transporters. Experimentally, the unique structure of the transporters was recently confirmed by membrane topology studies. Although there is still controversy about part of the topology, the most likely model predicts the presence of eight membrane-spanning ?-helices and a loop-pore structure which is unique among secondary transporters but may resemble loop-pores found in ion channels. A second distinctive structural feature is the presence of a highly amphipathic membrane-spanning helix that provides a hydrophilic path through the membrane. Recent data from analysis of site-directed mutants and studies on the mechanism and pharmacology of the transporters are discussed in relation to the structural model.

Slotboom, Dirk Jan; Konings, Wil N.; Lolkema, Juke S.

1999-01-01

274

Bacterial Infections in Renal Transplant Recipients  

Microsoft Academic Search

Urinary tract infection (UTI) is considered as one of the important bacterial infections seen among renal transplant recipi- ents. In the present study, bacterial urinary tract infections in renal transplant recipients were investigated. Eighty-seven renal transplant recipients (57 males and 30 females) were included to study the bacterial UTIs. Clean- catch midstream urine specimens were obtained from patients and studied

MH Shirazi; R Ranjbar; F Hemati

275

Inhibitors of bacterial tubulin target bacterial membranes in vivo.  

PubMed

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

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

2012-07-18

276

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

PubMed

Bacterial production of visible light is a natural phenomenon occurring in marine (Vibrio and Photobacterium) and terrestrial (Photorhabdus) species. The mechanism underpinning light production in these organisms is similar and involves the oxidation of an aldehyde substrate in a reaction catalysed by the bacterial luciferase enzyme. The genes encoding the luciferase and a fatty acid reductase complex which synthesizes the substrate are contained in a single operon (the lux operon). This provides a useful reporter system as cloning the operon into a recipient host bacterium will generate visible light without the requirement to add exogenous substrate. The light can be detected in vivo in the living animal using a sensitive detection system and is therefore ideally suited to bioluminescence imaging protocols. The system has therefore been widely used to track bacteria during infection or colonisation of the host. As bacteria are currently being examined as bactofection vectors for gene delivery, particularly to tumour tissue, the use of bioluminescence imaging offers a powerful means to investigate vector amplification in situ. The implications of this technology for bacterial localization, tumour targeting and gene transfer (bactofection) studies are discussed. PMID:22263920

Gahan, Cormac G M

2012-02-01

277

GH97 is a new family of glycoside hydrolases, which is related to the ?-galactosidase superfamily  

Microsoft Academic Search

BACKGROUND: As a rule, about 1% of genes in a given genome encode glycoside hydrolases and their homologues. On the basis of sequence similarity they have been grouped into more than ninety GH families during the last 15 years. The GH97 family has been established very recently and initially included only 18 bacterial proteins. However, the evolutionary relationship of the

Daniil G Naumoff

2005-01-01

278

The bacterial SoxAX cytochromes.  

PubMed

SoxAX cytochromes are heme-thiolate proteins that play a key role in bacterial thiosulfate oxidation, where they initiate the reaction cycle of a multi-enzyme complex by catalyzing the attachment of sulfur substrates such as thiosulfate to a conserved cysteine present in a carrier protein. SoxAX proteins have a wide phylogenetic distribution and form a family with at least three distinct types of SoxAX protein. The types of SoxAX cytochromes differ in terms of the number of heme groups present in the proteins (there are diheme and triheme versions) as well as in their subunit structure. While two of the SoxAX protein types are heterodimers, the third group contains an additional subunit, SoxK, that stabilizes the complex of the SoxA and SoxX proteins. Crystal structures are available for representatives of the two heterodimeric SoxAX protein types and both of these have shown that the cysteine ligand to the SoxA active site heme carries a modification to a cysteine persulfide that implicates this ligand in catalysis. EPR studies of SoxAX proteins have also revealed a high complexity of heme dependent signals associated with this active site heme; however, the exact mechanism of catalysis is still unclear at present, as is the exact number and types of redox centres involved in the reaction. PMID:22907414

Kappler, Ulrike; Maher, Megan J

2012-08-21

279

Autophagy and bacterial infectious diseases.  

PubMed

Autophagy is a housekeeping process that maintains cellular homeostasis through recycling of nutrients and degradation of damaged or aged cytoplasmic constituents. Over the past several years, accumulating evidence has suggested that autophagy can function as an intracellular innate defense pathway in response to infection with a variety of bacteria and viruses. Autophagy plays a role as a specialized immunologic effector and regulates innate immunity to exert antimicrobial defense mechanisms. Numerous bacterial pathogens have developed the ability to invade host cells or to subvert host autophagy to establish a persistent infection. In this review, we have summarized the recent advances in our understanding of the interaction between antibacterial autophagy (xenophagy) and different bacterial pathogens. PMID:22257885

Yuk, Jae Min; Yoshimori, Tamotsu; Jo, Eun Kyeong

2012-02-29

280

Musculoskeletal manifestations of bacterial endocarditis.  

PubMed Central

The records of 180 patients out of 247 with bacterial endocarditis were examined. 50 patients had rheumatic manifestations. In 10 there was arthritis of 2-12 weeks' duration before diagnosis; 19 had myalgia/arthralgia; 17 had back or neck pain; 14 had demonstrable arthritis; and 2 tenosynovitis of the foot. Of the 14 patients with arthritis, 8 had monarticular arthritis and 6 polyarticular. All but one patient had a raised erythrocyte sedimentation rate, and in one patient rheumatoid factor was positive. The rheumatic features responded when the endocarditis was treated. Some of the symptoms undoubtedly resulted from the infection and fever of the endocarditis, and emboli may have caused the transient aches but there was no evidence that they caused the synovitis in the patients with arthritis. The rheumatic manifestations of bacterial endocarditis can mimic other rheumatic diseases and disguise the underlying disease.

Meyers, O L; Commerford, P J

1977-01-01

281

Bacterial meningitis: new therapeutic approaches.  

PubMed

Bacterial meningitis remains a disease with high mortality and long-term morbidity. Outcome critically depends on the rapid initiation of effective antibiotic therapy. Since a further increase of the incidence of pathogens resistant to antibacterials can be expected both in community-acquired and nosocomial bacterial meningitis, the choice of an optimum initial empirical antibiotic regimen will gain significance. In this context, the use of antibiotics which are bactericidal but do not lyse bacteria, may emerge as a therapeutic option. Conversely, the role of corticosteroids, which decrease the entry of hydrophilic antibacterials into the cerebrospinal fluid, as adjunctive therapy will probably decline as a consequence of the increasing antibiotic resistance of bacteria causing meningitis. Consequent vaccination of all children at present is the most efficient manner to reduce disease burden. PMID:24073921

Nau, Roland; Djukic, Marija; Spreer, Annette; Eiffert, Helmut

2013-09-27

282

Bacterial streamers in curved microchannels  

NASA Astrophysics Data System (ADS)

Biofilms, generally identified as microbial communities embedded in a self-produced matrix of extracellular polymeric substances, are involved in a wide variety of health-related problems ranging from implant-associated infections to disease transmissions and dental plaque. The usual picture of these bacterial films is that they grow and develop on surfaces. However, suspended biofilm structures, or streamers, have been found in natural environments (e.g., rivers, acid mines, hydrothermal hot springs) and are always suggested to stem from a turbulent flow. We report the formation of bacterial streamers in curved microfluidic channels. By using confocal laser microscopy we are able to directly image and characterize the spatial and temporal evolution of these filamentous structures. Such streamers, which always connect the inner corners of opposite sides of the channel, are always located in the middle plane. Numerical simulations of the flow provide evidences for an underlying hydrodynamic mechanism behind the formation of the streamers.

Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

2009-11-01

283

Sulfate decomposition by bacterial leaching  

Microsoft Academic Search

Sulfate disposal is the main problem of many industrial effluents, such as excess sulfuric acid, gypsum, coal desulfurization\\u000a byproducts, acid-mine waters, and general metallurgical effluents. It has been established that sulfate present in wastes\\u000a can be converted to elemental sulfur by bacterial mutualism. This study presents the results of an investigation of the industrial\\u000a feasibility of utilizing a biological system

Nuran Deveci; Cüneyt Göktug Delaloglu

1995-01-01

284

Bacterial Contamination of Blood Components  

PubMed Central

Blood for transfusion is a potential source of infection by a variety of known and unknown transmissible agents. Over the last 20 years, astounding reductions in the risk of viral infection via allogeneic blood have been achieved. As a result of this success, bacterial contamination of blood products has emerged as the greatest residual source of transfusion-transmitted disease. This paper summarizes the current status of detection, prevention, and elimination of bacteria in blood products for transfusion.

Brecher, Mark E.; Hay, Shauna N.

2005-01-01

285

Vulvovaginal candidiasis and bacterial vaginosis.  

PubMed

Vulvovaginal candidiasis (VVC) and bacterial vaginosis (BV) are frequently encountered in clinical practice. Recent advances have furthered understanding of pathophysiology. Proper diagnosis, based on appropriate office and, in complicated cases, laboratory tests is the key to rational selection of therapy. For women who have routine uncomplicated episodes of VVC or BV, a variety of effective treatment options exists. Recurrent disease remains a challenge for these conditions but can often be managed successfully. PMID:18954756

Nyirjesy, Paul

2008-12-01

286

Bacterial endocarditis complicating body art.  

PubMed

Increasing numbers of patients are living with congenital heart disease at a time when body art is growing in popularity. We present a case of subacute bacterial endocarditis following repeated tattooing in a patient with known valvular heart disease. This case highlights the importance of education of patients with structural heart disease to the potential risks of such procedures, particularly at a time when endocarditis prophylaxis protocols are being revised. PMID:18180055

Tse, Donald; Khan, Sadia; Clarke, Sarah

2008-01-03

287

Bacterial degradation of bile salts  

Microsoft Academic Search

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

Bodo Philipp

2011-01-01

288

Bacterial Endocarditis: A Short Overview  

PubMed Central

Bacterial (infective) endocarditis is a potentially fatal illness which may follow transient bacteremia induced by certain dental procedures. It is the purpose of this article to discuss the rationale behind the American Heart Association's current guidelines on antibiotic prophylaxis for this disease, to consider the dentist's role in implementing these recommendations, and to identify how the physician and dentist can act in the patient's best interests to prevent this illness.

Kilmartin, C.

1988-01-01

289

Functional Bacterial Amyloids in Biofilms  

Microsoft Academic Search

\\u000a Functional bacterial amyloids constitute a group of important proteinaceous surface structures. Most amyloids are highly insoluble\\u000a in water and resistant to most enzymes and thermal and chemical denaturants. Their functions in bacteria are still not well\\u000a described but seem to include fimbriae and other cell appendages for adhesion and biofilm formation, cell envelope components,\\u000a spore coating, formation of large extracellular

Per Halkjćr Nielsen; Morten Simonsen Dueholm; Trine Rolighed Thomsen; Jeppe Lund Nielsen; Daniel Otzen

290

Cytochemical Differences in Bacterial Glycocalyx  

NASA Astrophysics Data System (ADS)

To examine new cytochemical aspects of the bacterial adhesion, a strain 41452/01 of the oral commensal Streptococcus sanguis and a wild strain of Staphylococcus aureus were grown with and without sucrose supplementation for 6 days. Osmiumtetraoxyde (OsO4), uranyl acetate (UA), ruthenium red (RR), cupromeronic blue (CB) staining with critical electrolytic concentrations (CECs), and the tannic acid-metal salt technique (TAMST) were applied for electron microscopy. Cytochemically, only RR-positive fimbriae in S. sanguis were visualized. By contrast, some types of fimbriae staining were observed in S. aureus glycocalyx: RR-positive, OsO4-positive, tannophilic and CB-positive with ceasing point at 0.3 M MgCl2. The CB staining with CEC, used for the first time for visualization of glycoproteins of bacterial glycocalyx, also reveals intacellular CB-positive substances-probably the monomeric molecules, that is, subunits forming the fimbriae via extracellular assembly. Thus, glycosylated components of the biofilm matrix can be reliably related to single cells. The visualization of intracellular components by CB with CEC enables clear distinction between S. aureus and other bacteria, which do not produce CB-positive substances. The small quantities of tannophilic substances found in S. aureus makes the use of TAMST for the same purpose difficult. The present work protocol enables, for the first time, a partial cytochemical differentiation of the bacterial glycocalyx.

Krautgartner, Wolf Dietrich; Vitkov, Ljubomir; Hannig, Matthias; Pelz, Klaus; Stoiber, Walter

2005-02-01

291

Bacterial infections complicating tongue piercing  

PubMed Central

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

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

2010-01-01

292

Bacterial infections complicating tongue piercing.  

PubMed

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

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

2010-01-01

293

Antibiotic resistance of bacterial biofilms.  

PubMed

A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and disinfectant chemicals as well as resisting phagocytosis and other components of the body's defence system. The persistence of, for example, staphylococcal infections related to foreign bodies is due to biofilm formation. Likewise, chronic Pseudomonas aeruginosa lung infection in cystic fibrosis patients is caused by biofilm-growing mucoid strains. Characteristically, gradients of nutrients and oxygen exist from the top to the bottom of biofilms and these gradients are associated with decreased bacterial metabolic activity and increased doubling times of the bacterial cells; it is these more or less dormant cells that are responsible for some of the tolerance to antibiotics. Biofilm growth is associated with an increased level of mutations as well as with quorum-sensing-regulated mechanisms. Conventional resistance mechanisms such as chromosomal beta-lactamase, upregulated efflux pumps and mutations in antibiotic target molecules in bacteria also contribute to the survival of biofilms. Biofilms can be prevented by early aggressive antibiotic prophylaxis or therapy and they can be treated by chronic suppressive therapy. A promising strategy may be the use of enzymes that can dissolve the biofilm matrix (e.g. DNase and alginate lyase) as well as quorum-sensing inhibitors that increase biofilm susceptibility to antibiotics. PMID:20149602

Hřiby, Niels; Bjarnsholt, Thomas; Givskov, Michael; Molin, Sřren; Ciofu, Oana

2010-02-10

294

Mechanism of Bacterial Pyrite Oxidation  

PubMed Central

The oxidation by Ferrobacillus ferrooxidans of untreated pyrite (FeS2) as well as HCl-pretreated pyrite (from which most of the acid-soluble iron species were removed) was studied manometrically. Oxygen uptake was linear during bacterial oxidation of untreated pyrite, whereas with HCl-pretreated pyrite both a decrease in oxygen uptake at 2 hr and nonlinear oxygen consumption were observed. Ferric sulfate added to HCl-pretreated pyrite restored approximately two-thirds of the decrease in total bacterial oxygen uptake and caused oxygen uptake to revert to nearly linear kinetics. Ferric sulfate also oxidized pyrite in the absence of bacteria and O2; recovery of ferric and ferrous ions was in excellent agreement with the reaction Fe2(SO4)3 + FeS2 = 3FeSO4 + 2S, but the elemental sulfur produced was negligible. Neither H2S nor S2O32? was a product of the reaction. It is probable that two mechanisms of bacterial pyrite oxidation operate concurrently: the direct contact mechanism which requires physical contact between bacteria and pyrite particles for biological pyrite oxidation, and the indirect contact mechanism according to which the bacteria oxidize ferrous ions to the ferric state, thereby regenerating the ferric ions required for chemical oxidation of pyrite.

Silverman, Melvin P.

1967-01-01

295

Bacterial reservoirs in cystic fibrosis.  

PubMed Central

To establish whether colonisation of the upper respiratory tract or bacterial contamination of inhaler devices or solutions predisposes to colonisation of the lower respiratory tract in patients with cystic fibrosis, bacterial isolates from groups of children who were positive (n = 13) or negative (n = 18) for Pseudomonas aeruginosa were studied. Cultures of swabs from inhaler devices, toothbrushes, and upper airways were compared with cough swabs or sputum cultures. No pathogens were obtained from inhaler equipment administering unit dose medications. Upper airway carriage of Staphylococcus aureus and Haemophilus influenzae was identified in both groups but correlated poorly with sputum isolates. P. aeruginosa was found only in the upper respiratory tract of children with established colonisation of the lower airways. No P aeruginosa isolates were obtained from the upper airways of the group with negative sputum, including one patient who became colonised by P aeruginosa during the study. Our results did not support the suggestion that colonisation of the upper respiratory tract by P aeruginosa predisposes to colonisation of the lower airways. Failure to isolate pathogenic organisms consistently from the upper airways in patients with positive sputum argues against a local epithelial factor predisposing to bacterial colonisation.

Taylor, C J; McGaw, J; Howden, R; Duerden, B I; Baxter, P S

1990-01-01

296

Relationships between host phylogeny, host type and bacterial community diversity in cold-water coral reef sponges.  

PubMed

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

Schöttner, Sandra; Hoffmann, Friederike; Cárdenas, Paco; Rapp, Hans Tore; Boetius, Antje; Ramette, Alban

2013-02-05

297

Family Processes and Identity  

Microsoft Academic Search

\\u000a Family is a unique relationship context that influences the contents and processes of identity. The identity of individuals\\u000a emerges, at least in part, from being members of a family. Moreover, the family context influences not only the development\\u000a of one’s personal identity as a family member but also other aspects of personal identity. Family is not a neutral environment\\u000a for

Eugenia Scabini; Claudia Manzi

298

Contribution of bacterial outer membrane vesicles to innate bacterial defense  

PubMed Central

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

2011-01-01

299

AIDS and the family: families take care.  

PubMed

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

1994-01-01

300

Family Health History and Diabetes  

MedlinePLUS

... Health History and Diabetes Family Health History and Diabetes En espańol Family health history is an important ... Four Questions You Should Ask Your Family About Diabetes & Family Health History Knowing your family health history ...

301

Strengthening Family Practices for Latino Families  

ERIC Educational Resources Information Center

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

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

2010-01-01

302

Fatal familial insomnia: a new Austrian family  

Microsoft Academic Search

Summary We present clinical, pathological and molecular features of the first Austrian family with fatal familial insomnia. Detailed clinical data are available in five patients and autopsy in four patients. Age at onset of disease ranged between 20 and 60 years, and disease duration between 8 and 20 months. Severe loss of weight was an early symptom in all five

G. Almer; J. A. Hainfellner; T. Brucke; K. Jellinger; R. Kleinert; G. Bayer; O. Windl; H. A. Kretzschmar; A. Hill; K. Sidle; J. Collinge; H. Budka

1999-01-01

303

Distinct Soil Bacterial Communities Revealed under a Diversely Managed Agroecosystem  

PubMed Central

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

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

2012-01-01

304

Distinct soil bacterial communities revealed under a diversely managed agroecosystem.  

PubMed

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

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

2012-07-23

305

Phylogenetically and spatially close marine sponges harbour divergent bacterial communities.  

PubMed

Recent studies have unravelled the diversity of sponge-associated bacteria that may play essential roles in sponge health and metabolism. Nevertheless, our understanding of this microbiota remains limited to a few host species found in restricted geographical localities, and the extent to which the sponge host determines the composition of its own microbiome remains a matter of debate. We address bacterial abundance and diversity of two temperate marine sponges belonging to the Irciniidae family--Sarcotragus spinosulus and Ircinia variabilis--in the Northeast Atlantic. Epifluorescence microscopy revealed that S. spinosulus hosted significantly more prokaryotic cells than I. variabilis and that prokaryotic abundance in both species was about 4 orders of magnitude higher than in seawater. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) profiles of S. spinosulus and I. variabilis differed markedly from each other--with higher number of ribotypes observed in S. spinosulus--and from those of seawater. Four PCR-DGGE bands, two specific to S. spinosulus, one specific to I. variabilis, and one present in both sponge species, affiliated with an uncultured sponge-specific phylogenetic cluster in the order Acidimicrobiales (Actinobacteria). Two PCR-DGGE bands present exclusively in S. spinosulus fingerprints affiliated with one sponge-specific phylogenetic cluster in the phylum Chloroflexi and with sponge-derived sequences in the order Chromatiales (Gammaproteobacteria), respectively. One Alphaproteobacteria band specific to S. spinosulus was placed in an uncultured sponge-specific phylogenetic cluster with a close relationship to the genus Rhodovulum. Our results confirm the hypothesized host-specific composition of bacterial communities between phylogenetically and spatially close sponge species in the Irciniidae family, with S. spinosulus displaying higher bacterial community diversity and distinctiveness than I. variabilis. These findings suggest a pivotal host-driven effect on the shape of the marine sponge microbiome, bearing implications to our current understanding of the distribution of microbial genetic resources in the marine realm. PMID:23300853

Hardoim, Cristiane C P; Esteves, Ana I S; Pires, Francisco R; Gonçalves, Jorge M S; Cox, Cymon J; Xavier, Joana R; Costa, Rodrigo

2012-12-27

306

Surface enhanced bacterial fluorescence and enumeration of bacterial adhesion.  

PubMed

The use of flow displacement systems for studying initial bacterial adhesion to surfaces is mostly confined to transparent substrata. The objective of this study was to investigate a method based on macroscopic fluorescence imaging to enumerate adhering fluorescent bacteria on non-transparent substrata, real-time and under flow. To this end, a stepwise protocol is described to quantify adhesion of green-fluorescent-protein producing Staphylococcus aureus on polished and non-polished metal and polymer surfaces accounting for surface-enhanced-fluorescence on metal surfaces, quantified by the ratio of the single cell fluorescence observed for adhering and planktonic bacteria. Enumeration of adhering fluorescent staphylococci by the proposed method is consistent with results obtained using metallurgical microscopy. An advantage however, is that the non-homogeneous surface coverage and surface roughness do not limit the applicability of the method. Moreover, the accurate quantification of surface-enhanced-fluorescence arising from adhering bacteria offers a new pathway for evaluating bacterial cell surface deformation during adhesion. PMID:23185995

Li, Jiuyi; Busscher, Henk J; van der Mei, Henny C; Sjollema, Jelmer

2013-01-01

307

Bacterial Adhesion at Synthetic Surfaces  

PubMed Central

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.

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

1999-01-01

308

Functional microdomains in bacterial membranes  

PubMed Central

The membranes of eukaryotic cells harbor microdomains known as lipid rafts that contain a variety of signaling and transport proteins. Here we show that bacterial membranes contain microdomains functionally similar to those of eukaryotic cells. These membrane microdomains from diverse bacteria harbor homologs of Flotillin-1, a eukaryotic protein found exclusively in lipid rafts, along with proteins involved in signaling and transport. Inhibition of lipid raft formation through the action of zaragozic acid—a known inhibitor of squalene synthases—impaired biofilm formation and protein secretion but not cell viability. The orchestration of physiological processes in microdomains may be a more widespread feature of membranes than previously appreciated.

Lopez, Daniel; Kolter, Roberto

2010-01-01

309

Bacterial biofilms and chronic rhinosinusitis.  

PubMed

Chronic rhinosinusitis (CRS) is a highly prevalent disease in the adult and pediatric population. It causes significant burden and the management is considered one of the most costly public health conditions. Comorbidities include asthma, aspirin sensitivity, and nasal polyposis. Staphylococcus aureus biofilms and exotoxins that act as superantigens have been implicated to play an important pathological role in the incidence, maintenance, and ongoing burden of CRS. A better understanding of the interplay between bacterial factors, host factors, and the environment will facilitate better management of this disease. This literature review focuses on these factors and highlights current research in this field. PMID:23484638

Madeo, Jennifer; Frieri, Marianne

2013-03-07

310

Bacterial EPIYA effectors - Where do they come from? What are they? Where are they going?  

PubMed Central

Recent studies have revealed a distinct class of bacterial effectors defined by the presence of EPIYA or EPIYA-related motif. These bacterial EPIYA effectors are delivered into host cells via type III or IV secretion, where they undergo tyrosine phosphorylation at the EPIYA motif and thereby manipulate host signalling by promiscuously interacting with multiple SH2 domain-containing proteins. Up to now, nine EPIYA effectors have been identified from various bacteria. These effectors do not share sequence homology outside the EPIYA motif, arguing against the idea that they have common ancestors. A search of mammalian proteomes revealed the presence of a mammalian EPIYA-containing protein, Pragmin, which potentiates Src family kinase (SFK) activity by binding and sequestrating the SFK inhibitor Csk upon EPIYA phosphorylation. As several bacterial EPIYA effectors also target Csk, they may have evolved through generation of sequences that mimic the Pragmin EPIYA motif. EPIYA motifs are often diverged through multiple duplications in each bacterial effector. Such a structural plasticity appears to be due to intrinsic disorder of the EPIYA-containing region, which enables the bacterial effectors to undergo efficient phosphorylation and mediate promiscuous interaction with multiple host proteins. Given the functional versatility of the EPIYA motif, many more bacterial EPIYA effectors will soon be emerging.

Hayashi, Takeru; Morohashi, Hiroko; Hatakeyama, Masanori

2013-01-01

311

Self-similar dynamics of bacterial chemotaxis.  

PubMed

Colonies of bacteria grown on thin agar plate exhibit fractal patterns as a result of adaptation to their environments. The bacterial colony pattern formation is regulated crucially by chemotaxis, the movement of cells along a chemical concentration gradient. Here, the dynamics of pattern formation in a bacterial colony is investigated theoretically through a continuum model that considers chemotaxis. In the case of the gradient sensed by the bacterium is nearly uniform, the bacterial colony patterns are self-similar, which means they look the same at every scale. The scaling law of the bacterial colony growth has been revealed explicitly. Chemotaxis biases the movement of the bacterial population in colony to trend toward the chemical attractant. Moreover, the bacterial colonies evolve for a long time as the traveling wave with a sharp front. PMID:23367993

Ngamsaad, Waipot; Khompurngson, Kannika

2012-12-17

312

Self-similar dynamics of bacterial chemotaxis  

NASA Astrophysics Data System (ADS)

Colonies of bacteria grown on thin agar plate exhibit fractal patterns as a result of adaptation to their environments. The bacterial colony pattern formation is regulated crucially by chemotaxis, the movement of cells along a chemical concentration gradient. Here, the dynamics of pattern formation in a bacterial colony is investigated theoretically through a continuum model that considers chemotaxis. In the case of the gradient sensed by the bacterium is nearly uniform, the bacterial colony patterns are self-similar, which means they look the same at every scale. The scaling law of the bacterial colony growth has been revealed explicitly. Chemotaxis biases the movement of the bacterial population in colony to trend toward the chemical attractant. Moreover, the bacterial colonies evolve for a long time as the traveling wave with a sharp front.

Ngamsaad, Waipot; Khompurngson, Kannika

2012-12-01

313

Family Dysfunction and Family Psychopathology in Child Psychiatry Outpatients  

Microsoft Academic Search

The prevalence of nuclear family dysfunction and psychopathology in first- and second-degree relatives and the association between these two variables was studied in families of 100 children with psychiatric disorders. Brief, standardized family assessment instruments were used. Family dysfunction was measured by the Family Assessment Device; family history of psychiatric illness was measured by the revised Family History-Research Diagnostic Criteria.

Mary A. Fristad; Traci L. Clayton

1991-01-01

314

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

PubMed Central

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

2012-01-01

315

Signaling-Mediated Bacterial Persister Formation  

PubMed Central

Here we show that bacterial communication through indole signaling induces persistence, a phenomenon in which a subset of an isogenic bacterial population tolerates antibiotic treatment. We monitor indole-induced persister formation using microfluidics, and identify the role of oxidative stress and phage-shock pathways in this phenomenon. We propose a model in which indole signaling “inoculates” a bacterial sub-population against antibiotics by activating stress responses, leading to persister formation.

Vega, Nicole M.; Allison, Kyle R.; Khalil, Ahmad S.; Collins, James J.

2011-01-01

316

Microalgal-facilitated bacterial oxidation of manganese  

Microsoft Academic Search

In the presence of unicellular microalgae, bacterial manganese oxidation was increased by up to ten times the rate produced by bacterial oxidation alone. Azide-poisoned controls demonstrated that the manganese-oxidizing bacteria were active in the algal-bacterial oxidation of manganese. Scanning electron microscopy showed that oxide formation occurred in a number of structurally different deposits on the surface of the alga. Studies

R M Stuetz; A C Greene; J C Madgwick

1996-01-01

317

Bacterial virus contamination of fetal bovine sera  

Microsoft Academic Search

Summary  Thirty-seven lots of fetal bovine sera were examined for the presence ofEscherichia coli-specific bacterial viruses, and 23 were positive. No correlation was found between the presence of bacterial virus and poor\\u000a growth-promoting qualities of the sera. One bacterial virus contaminant of fetal bovine serum was isolated and examined by\\u000a electron microscopy.

Fred C. Chu; Joyce B. Johnson; Henry C. Orr; Peter G. Probst; John C. Petricciani

1973-01-01

318

Signaling-mediated bacterial persister formation.  

PubMed

Here we show that bacterial communication through indole signaling induces persistence, a phenomenon in which a subset of an isogenic bacterial population tolerates antibiotic treatment. We monitor indole-induced persister formation using microfluidics and identify the role of oxidative-stress and phage-shock pathways in this phenomenon. We propose a model in which indole signaling 'inoculates' a bacterial subpopulation against antibiotics by activating stress responses, leading to persister formation. PMID:22426114

Vega, Nicole M; Allison, Kyle R; Khalil, Ahmad S; Collins, James J

2012-03-18

319

Normative Family Development.  

ERIC Educational Resources Information Center

Describes the sequentially developmental life stages of healthy, normal families. Provides an exposition of these developmental stages and forms as a guide or normative framework within which to test for dysfunction and pathology in the family process. (Author/JAC)

Barcai, Avner

1981-01-01

320

Familial Periodic Paralyses  

MedlinePLUS

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

321

American Families Project.  

ERIC Educational Resources Information Center

|Describes the "American Families Project," in which students from two or more schools participate in a creative writing, historical research activity, each playing a role in a fictitious family living in 1838 and corresponding with each other. (RS)|

Medeiros, Ray

1992-01-01

322

Family Money Troubles  

MedlinePLUS

... a while. How Does a Difficult Economy Affect Families? For some people, the slow economy means eating ... put toward allowances or college funds. For other families, though, money problems mean bigger changes, such as ...

323

Families and Friends  

MedlinePLUS

... chapter Join our online community Helping Friends and Family Part of living well with Alzheimerâ??s is adjusting to your â??new normalâ?ť and helping family and friends do the same. Knowing what to ...

324

Assessing Postpartum Family Functioning  

PubMed Central

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

Midmer, Deana; Talbot, Yves

1988-01-01

325

Learning about Familial Hypercholesterolemia  

MedlinePLUS

... is inherited in families in an autosomal dominant manner. In autosomal dominant inherited conditions, a parent who ... Familial hypercholesterolemia is inherited in an autosomal dominant manner. This means that to have this condition, it ...

326

Family Patterns in Dogmatism  

ERIC Educational Resources Information Center

|Explored Rokeach's theory that dogmatism develops within the family. Subjects were college students and their parents who took the 40-item Dogmatism Scale. Results indicated that family experiences are one source of children's dogmatism but not the only source. (SDH)|

Lesser, Harvey; Steininger, Marion

1975-01-01

327

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

PubMed

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

Kofoed, Eric M; Vance, Russell E

2011-08-28

328

Bacterial hemagglutination by Neisseria gonorrhoeae.  

PubMed Central

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

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

1975-01-01

329

Acute bacterial meningitis in Nepal.  

PubMed

This study was conducted at Tribhuvan University Teaching Hospital, a tertiary care hospital in Nepal from January 2001 to March 2002. The prevalence of bacterial meningitis, its causative organisms and their antibiotic sensitivity patterns were studied in cerebrospinal fluid of 448 suspected cases. The prevalence of acute bacterial meningitis was 8.3%. There was no significant association (p > 0.05) of the disease with gender (X2 = 0.0234) and among different age groups (X2 = 6.07875) studied. The causative bacteria were Pseudomonas aeruginosa (24.3%), Klebsiella pneumoniae (16.2%), Staphylococcus aureus (16.2%), coagulase negative staphylococci (10.8%), Escherichia coli (10.8%), Streptococcus pneumoniae (8.2%), Neisseria meningitidis (5.4%), Acinetobacter spp. (5.4%) and Aeromoanas spp. (2.7%). Imipenem was the most effective antibiotic, however, 11.1% of P. aeruginosa, 25.0% of E. coli and 50.0% of Acinetobacter spp. were resistant to the drug. PMID:17899958

Tiwari, Kiran Babu; Rijal, Basista; Ghimire, Prakash; Sharma, Achyut Prasad

2007-06-01

330

Immunization by a bacterial aerosol.  

PubMed

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

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

2008-03-14

331

Bacterial pathogen genomics and vaccines.  

PubMed

Infectious diseases remain a major cause of deaths and disabilities in the world, the majority of which are caused by bacteria. Although immunisation is the most cost effective and efficient means to control microbial diseases, vaccines are not yet available to prevent many major bacterial infections. Examples include dysentery (shigellosis), gonorrhoea, trachoma, gastric ulcers and cancer (Helicobacter pylori). Improved vaccines are needed to combat some diseases for which current vaccines are inadequate. Tuberculosis, for example, remains rampant throughout most countries in the world and represents a global emergency heightened by the pandemic of HIV. The availability of complete genome sequences has dramatically changed the opportunities for developing novel and improved vaccines and facilitated the efficiency and rapidity of their development. Complete genomic databases provide an inclusive catalogue of all potential candidate vaccines for any bacterial pathogen. In conjunction with adjunct technologies, including bioinformatics, random mutagenesis, microarrays, and proteomics, a systematic and comprehensive approach to identifying vaccine discovery can be undertaken. Genomics must be used in conjunction with population biology to ensure that the vaccine can target all pathogenic strains of a species. A proof in principle of the utility of genomics is provided by the recent exploitation of the complete genome sequence of Neisseria meningitidis group B. PMID:12176849

Moxon, Richard; Rappuoli, Rino

2002-01-01

332

Chromophore-enhanced bacterial photothermolysis  

NASA Astrophysics Data System (ADS)

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

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

1999-06-01

333

Organization of the bacterial chromosome.  

PubMed Central

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.

Krawiec, S; Riley, M

1990-01-01

334

Bacterial swimming strategies and turbulence  

PubMed Central

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.

Luchsinger, RH; Bergersen, B; Mitchell, JG

1999-01-01

335

Bacterial meningitis in Navojo Indians.  

PubMed Central

An analysis of 219 confirmed cases of bacterial meningitis among Navajo Indians during a 5-year period, July 1, 1968, through June 30, 1973, revealed that 56 percent were caused by Haemophilus influenzae, 26 percent by Neisseria meningitidis, 6 percent by Mycobacterium tuberculosis, and 6 percent by other organisms. The annual incidence of H. influenzae meningitis (17.7 per 100,000 persons) and that of pneumococcal meningitis (8.0 per 100,000) were much higher than the rates for these diseases reported from other population groups. The annual incidence of meningococcal meningitis (2.0 per 100,000) was similar to that found elsewhere. There was an ususual concentration of cases during the first year of life; 78 percent of H. influenzae, 64 percent of pneumococcal, and 50 percent of meningococcal meningitis occurred during this time. However, bacterial meningitis during the first month of life was not frequent (0.29 per 1,000 live births). Case fatality rates were similar to those reported for other population groups.

Coulehan, J L; Michaels, R H; Williams, K E; Lemley, D K; North, C Q; Welty, T K; Rogers, K D

1976-01-01

336

3D Side View of Bacterial Biofilm  

NSDL National Science Digital Library

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.

American Society For Microbiology;

2002-01-01

337

Family Communication Patterns  

Microsoft Academic Search

Previous research has studied the influence of concept and socio oriented family communication on American adolescent purchase influence (Foxman, Tansuhaj, and Ekstrom 1989). This study extends this research by explicitly examining the perceived influence of four types of family communication patterns on family decision making among children between the ages of eight and twelve years for three types of products

Aysen Bakir; Gregory M. Rose; Aviv Shoham

2006-01-01

338

Training of Family Physicians  

ERIC Educational Resources Information Center

Noting that family practice is increasingly accepted as part of the academic system, the author discusses its philosophy, overviews undergraduate programs and residency programs, presenting a sample curriculum outline for a 3-year family practice residency and emphasizing the need for continuity of care and a family practice office or center as a…

Rakel, Robert E.

1975-01-01

339

Establishing Family Math.  

ERIC Educational Resources Information Center

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

Bobango, Janet, Milgram, Joel

1993-01-01

340

Familial inflammatory dilated cardiomyopathy  

Microsoft Academic Search

Background: Systematic family screening has recently identified dilated cardiomyopathy as an inherited disorder in up to 30% of cases. Mutations in genes encoding proteins responsible for myocardial architecture have been identified, but additional pathophysiological mechanisms including inflammatory reactions have been proposed. Aims: Identification and characterization of familial DCM, where at least one affected family member fulfils the criteria for inflammatory

Irene Portig; Andreas Wilke; Matthias Freyland; Markus-Joachim Wolf; Anette Richter; Volker Ruppert; Sabine Pankuweit; Bernhard Maisch

2006-01-01

341

Family Support Evaluation.  

ERIC Educational Resources Information Center

The Family Resource Coalition of America (FRCA) and the National Resource Center for Family Centered Practice convened a meeting of evaluators, policymakers, and program practitioners to discuss the issue of evaluation in the field of family support. The goal was to bring together those who were implementing programs, evaluating programs, and…

Lalley, Jacqueline, Ed.; Ahsan, Nilofer, Ed.

1998-01-01

342

Toward the Postmodern Family  

ERIC Educational Resources Information Center

Examines three aspects of family life that are evolving in directions that have no historical precedent--adolescent indifference to the family's identity that shows up in the discontinuity of values from parents to children, instability in the life of the couple, and systematic demolition of the nuclear family. (Author/IRT)

Shorter, Edward

1976-01-01

343

Year of the Family.  

ERIC Educational Resources Information Center

|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…

California Agriculture, 1994

1994-01-01

344

Families Experiencing Homelessness  

MedlinePLUS

... all homeless mothers do not have a high school diploma. 29% of adults in homeless families are working. Have much higher rates of family separation than other low-income families. 4 Mothers Experiencing Homelessness: The impact of homelessness on mothers is profound. Many are ...

345

Fatherhood and Family Support.  

ERIC Educational Resources Information Center

|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…

Goetz, Kathy, Ed.

1996-01-01

346

Abstract Families of Languages.  

National Technical Information Service (NTIS)

The notion of an abstract family of language (AFL) as a family of sets of words satisfying certain properties common to many types of formal languages is introduced. Operations preserving AFL are then considered. The concept of an abstract family of accep...

S. Ginsburg S. Greibach

1968-01-01

347

Family Planning & Literacy.  

ERIC Educational Resources Information Center

This publication is an International Planned Parenthood Federation (IPPF) annotated bibliography of books and articles concerned with family planning and literacy. The subject is divided into four major listings: (1) Literacy; (2) Education; (3) Literacy and Family Planning; and (4) Functional Literacy/Family Planning Projects and Programs.…

International Planned Parenthood Federation, London (England).

348

Family Support Evaluation.  

ERIC Educational Resources Information Center

|The Family Resource Coalition of America (FRCA) and the National Resource Center for Family Centered Practice convened a meeting of evaluators, policymakers, and program practitioners to discuss the issue of evaluation in the field of family support. The goal was to bring together those who were implementing programs, evaluating programs, and…

Lalley, Jacqueline, Ed.; Ahsan, Nilofer, Ed.

1998-01-01

349

The Resiliency of Families.  

ERIC Educational Resources Information Center

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

Morrison, T. R.

350

The helix-turn-helix motif of bacterial insertion sequence IS911 transposase is required for DNA binding  

Microsoft Academic Search

The transposase of IS911, a member of the IS3 family of bacterial insertion sequences, is com- posed of a catalytic domain located at its C-terminal end and a DNA binding domain located at its N-terminal end. Analysis of the transposases of over 60 members of the IS3 family revealed the pres- ence of a helix-turn-helix (HTH) motif within the N-terminal

Philippe Rousseau; Erwan Gueguen; Guy Duval-Valentin; Mick Chandler

2004-01-01

351

Two Conserved Glutamates in the Bacterial Nitric Oxide Reductase Are Essential for Activity but Not Assembly of the Enzyme  

Microsoft Academic Search

The bacterial nitric oxide reductase (NOR) is a divergent member of the family of respiratory heme-copper oxidases. It differs from other family members in that it contains an FeB-heme-Fe dinuclear catalytic center rather than a CuB-heme-Fe center and in that it does not pump protons. Several glutamate residues are conserved in NORs but are absent in other heme-copper oxidases. To

GARETH BUTLAND; STEPHEN SPIRO; NICHOLAS J. WATMOUGH; DAVID J. RICHARDSON

2001-01-01

352

Statistical sampling of bacterial strains and its use in bacterial diversity measurement  

Microsoft Academic Search

The cultural bacterial strains of two sediment samples, i.e., 260 strains, were submitted to numerical taxonomy to determine “ecological profiles.” From these profiles several calculations of bacterial diversity were done with increasing number of strains (between 10 and 130). Studying 20–30 strains was sufficient to obtain a diversity of bacterial community.

Micheline A. G. Bianchi; Armand J. M. Bianchi

1982-01-01

353

Induction of the alkA gene of Escherichia coli in gram-negative bacteria.  

PubMed Central

A broad-host-range plasmid containing a fusion of the alkA and lacZ genes of Escherichia coli was introduced into various aerobic and facultative gram-negative bacteria--33 species belonging to 19 genera--to study the induction of expression of the alkA gene by alkylating agents. The bacteria included species of the families Enterobacteriaceae, Pseudomonadaceae, Rhizobiaceae, Vibrionaceae, Neisseriaceae, Rhodospirillaceae, and Azotobacteraceae. Results obtained show that all bacteria tested, except Aeromonas hydrophila, Agrobacterium tumefaciens, Hafnia alvei, Rhizobium meliloti, Salmonella enteritidis, Xanthomonas campestris, and those of the genus Rhodobacter, are able to induce the alkA gene of E. coli in the presence of N-methyl-N'-nitro-N-nitrosoguanidine. All these data indicate that the adaptive response to alkylating agents is present in bacterial species of several families and that the Ada box sequence must be widely conserved.

Fernandez de Henestrosa, A R; Barbe, J

1991-01-01

354

Microarray analysis of bacterial pathogenicity.  

PubMed

The DNA microarray, a surface that contains an ordered arrangement of each identified open reading frame of a sequenced genome, is the engine of functional genomics. Its output, the expression profile, provides a genome wide snap-shot of the transcriptome. Refined by array-specific statistical instruments and data-mined by clustering algorithms and metabolic pathway databases, the expression profile discloses, at the transcriptional level, how the microbe adapts to new conditions of growth--the regulatory networks that govern the adaptive response and the metabolic and biosynthetic pathways that effect the new phenotype. Adaptation to host microenvironments underlies the capacity of infectious agents to persist in and damage host tissues. While monitoring the whole genome transcriptional response of bacterial pathogens within infected tissues has not been achieved, it is likely that the complex, tissue-specific response is but the sum of individual responses of the bacteria to specific physicochemical features that characterize the host milieu. These are amenable to experimentation in vitro and whole-genome expression studies of this kind have defined the transcriptional response to iron starvation, low oxygen, acid pH, quorum-sensing pheromones and reactive oxygen intermediates. These have disclosed new information about even well-studied processes and provide a portrait of the adapting bacterium as a 'system', rather than the product of a few genes or even a few regulons. Amongst the regulated genes that compose this adaptive system are transcription factors. Expression profiling experiments of transcription factor mutants delineate the corresponding regulatory cascade. The genetic basis for pathogenicity can also be studied by using microarray-based comparative genomics to characterize and quantify the extent of genetic variability within natural populations at the gene level of resolution. Also identified are differences between pathogen and commensal that point to possible virulence determinants or disclose evolutionary history. The host vigorously engages the pathogen; expression studies using host genome microarrays and bacterially infected cell cultures show that the initial host reaction is dominated by the innate immune response. However, within the complex expression profile of the host cell are components mediated by pathogen-specific determinants. In the future, the combined use of bacterial and host microarrays to study the same infected tissue will reveal the dialogue between pathogen and host in a gene-by-gene and site- and time-specific manner. Translating this conversation will not be easy and will probably require a combination of powerful bioinformatic tools and traditional experimental approaches--and considerable effort and time. PMID:12073651

Schoolnik, Gary K

2002-01-01

355

Dysregulation of bacterial proteolytic machinery by a new class of antibiotics.  

PubMed

Here we show that a new class of antibiotics-acyldepsipeptides-has antibacterial activity against Gram-positive bacteria in vitro and in several rodent models of bacterial infection. The acyldepsipeptides are active against isolates that are resistant to antibiotics in clinical application, implying a new target, which we identify as ClpP, the core unit of a major bacterial protease complex. ClpP is usually tightly regulated and strictly requires a member of the family of Clp-ATPases and often further accessory proteins for proteolytic activation. Binding of acyldepsipeptides to ClpP eliminates these safeguards. The acyldepsipeptide-activated ClpP core is capable of proteolytic degradation in the absence of the regulatory Clp-ATPases. Such uncontrolled proteolysis leads to inhibition of bacterial cell division and eventually cell death. PMID:16200071

Brötz-Oesterhelt, Heike; Beyer, Dieter; Kroll, Hein-Peter; Endermann, Rainer; Ladel, Christoph; Schroeder, Werner; Hinzen, Berthold; Raddatz, Siegfried; Paulsen, Holger; Henninger, Kerstin; Bandow, Julia E; Sahl, Hans-Georg; Labischinski, Harald

2005-10-02

356

Fluid dynamics of bacterial turbulence.  

PubMed

Self-sustained turbulent structures have been observed in a wide range of living fluids, yet no quantitative theory exists to explain their properties. We report experiments on active turbulence in highly concentrated 3D suspensions of Bacillus subtilis and compare them with a minimal fourth-order vector-field theory for incompressible bacterial dynamics. Velocimetry of bacteria and surrounding fluid, determined by imaging cells and tracking colloidal tracers, yields consistent results for velocity statistics and correlations over 2 orders of magnitude in kinetic energy, revealing a decrease of fluid memory with increasing swimming activity and linear scaling between kinetic energy and enstrophy. The best-fit model allows for quantitative agreement with experimental data. PMID:23767750

Dunkel, Jörn; Heidenreich, Sebastian; Drescher, Knut; Wensink, Henricus H; Bär, Markus; Goldstein, Raymond E

2013-05-28

357

Molecular motors in bacterial secretion.  

PubMed

Secretion of effectors across bacterial membranes is usually mediated by large multisubunit complexes. In most cases, the secreted effectors are virulent factors normally associated to pathogenic diseases. The biogenesis of these secretion systems and the transport of the effectors are processes that require energy. This energy could be directly obtained by using the proton motive force, but in most cases the energy associated to these processes is derived from ATP hydrolysis. Here, a description of the machineries involved in generating the energy required for system biogenesis and substrate transport by type II, III and IV secretion systems is provided, with special emphasis on highlighting the structural similarities and evolutionary relationships among the secretion ATPases. PMID:23920498

Peńa, Alejandro; Arechaga, Ignacio

2013-08-05

358

Lipidomic analysis of bacterial plasmalogens.  

PubMed

Plasmalogens are a group of lipids with potentially important, and not yet fully known, functions in organisms from bacteria to protozoans, invertebrates, and mammals. They can protect cells against the damaging effects of reactive oxygen species, protect other phospholipids or lipoprotein particles against oxidative stress, and have been implicated as signaling molecules and modulators of membrane dynamics. They have been found in many anaerobic bacterial species, and their biosynthetic pathways differ in aerobic and anaerobic organisms. The use of advanced techniques permits the identification of not only plasmalogen classes but also their positional isomers and often also individual molecular species. This paper describes direct analyses of plasmalogens from natural sources, frequently very unusual, using electrospray ionization mass spectrometry in combination with high-performance liquid chromatography and/or shotgun lipidomics. PMID:22763737

?ezanka, Tomáš; K?esinová, Zdena; Kolouchová, Irena; Sigler, Karel

2012-07-05

359

Transfusion-associated bacterial sepsis.  

PubMed Central

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.

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

1994-01-01

360

Autophagy in intracellular bacterial infection.  

PubMed

Numerous pathogens have developed the capacity to invade host cells to be protected from components of the systemic immune system. However, once in the host cells they utilize sophisticated strategies to avoid the powerful machinery built by the cells to kill invading pathogens. In the last few years cumulative evidence indicates that autophagy is one of the most remarkable tools of the intracellular host cell defense machinery that bacteria must confront upon cell invasion. However, several pathogens subvert the autophagic pathway and, manipulate this process at the molecular level, as a strategy to establish a persistent infection. In this review we have summarized the interaction between autophagy and different bacterial pathogens including those that take advantage of the host cell autophagy, allowing successful colonization, as well as those microorganisms which are controlled by autophagy as part of the innate surveillance mechanism. PMID:19303905

Campoy, Emanuel; Colombo, María I

2009-03-19

361

Fluid Dynamics of Bacterial Turbulence  

NASA Astrophysics Data System (ADS)

Self-sustained turbulent structures have been observed in a wide range of living fluids, yet no quantitative theory exists to explain their properties. We report experiments on active turbulence in highly concentrated 3D suspensions of Bacillus subtilis and compare them with a minimal fourth-order vector-field theory for incompressible bacterial dynamics. Velocimetry of bacteria and surrounding fluid, determined by imaging cells and tracking colloidal tracers, yields consistent results for velocity statistics and correlations over 2 orders of magnitude in kinetic energy, revealing a decrease of fluid memory with increasing swimming activity and linear scaling between kinetic energy and enstrophy. The best-fit model allows for quantitative agreement with experimental data.

Dunkel, Jörn; Heidenreich, Sebastian; Drescher, Knut; Wensink, Henricus H.; Bär, Markus; Goldstein, Raymond E.

2013-05-01

362

Bacterial Exopolysaccharides: Functionality and Prospects  

PubMed Central

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.

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

2012-01-01

363

The bacterial ghost platform system  

PubMed Central

The Bacterial Ghost (BG) platform technology is an innovative system for vaccine, drug or active substance delivery and for technical applications in white biotechnology. BGs are cell envelopes derived from Gram-negative bacteria. BGs are devoid of all cytoplasmic content but have a preserved cellular morphology including all cell surface structures. Using BGs as delivery vehicles for subunit or DNA-vaccines the particle structure and surface properties of BGs are targeting the carrier itself to primary antigen-presenting cells. Furthermore, BGs exhibit intrinsic adjuvant properties and trigger an enhanced humoral and cellular immune response to the target antigen. Multiple antigens of the native BG envelope and recombinant protein or DNA antigens can be combined in a single type of BG. Antigens can be presented on the inner or outer membrane of the BG as well as in the periplasm that is sealed during BG formation. Drugs or supplements can also be loaded to the internal lumen or periplasmic space of the carrier. BGs are produced by batch fermentation with subsequent product recovery and purification via tangential flow filtration. For safety reasons all residual bacterial DNA is inactivated during the BG production process by the use of staphylococcal nuclease A and/or the treatment with ?-propiolactone. After purification BGs can be stored long-term at ambient room temperature as lyophilized product. The production cycle from the inoculation of the pre-culture to the purified BG concentrate ready for lyophilization does not take longer than a day and thus meets modern criteria of rapid vaccine production rather than keeping large stocks of vaccines. The broad spectrum of possible applications in combination with the comparably low production costs make the BG platform technology a safe and sophisticated product for the targeted delivery of vaccines and active agents as well as carrier of immobilized enzymes for applications in white biotechnology.

Langemann, Timo; Koller, Verena Juliana; Muhammad, Abbas; Kudela, Pavol; Mayr, Ulrike Beate

2010-01-01

364

Absorption Changes in Bacterial Chromatophores  

PubMed Central

The magnitude and kinetics of photo-induced absorption changes in bacterial chromatophores (R. rubrum, R. spheroides and Chromatium) have been studied as a function of potential, established by added redox couples. No photochanges can be observed above +0.55 v or below -0.15 v. The loss of signal at the higher potential is centered at +0.439 v and follows a one-electron change. The loss of signal at the lower potential is centered at -0.044 v and is also consistent with a one-electron change. Both losses are reversible. A quantitative relationship exists between light-minus-dark and oxidized-minus-reduced spectra in the near infrared from +0.30 to +0.55 v. Selective treatment of the chromatophores with strong oxidants irreversibly bleaches the bulk pigments but appears to leave intact those pigments responsible for the photo- and chemically-induced absorption changes. Kinetic studies of the photochanges in deaerated samples of R. rubrum chromatophores revealed the same rise time for bands at 433, 792, and 865 m? (t˝ = 50 msec.). However, these bands had different decay rates (t˝ = 1.5, 0.5, 0.15 sec., respectively), indicating that they belong to different pigments. Analysis of the data indicates, as the simplest interpretation, a first-order (or pseudo first-order) forward reaction and two parallel first-order (or pseudo first-order) decay reactions at each wavelength. These results imply that all pigments whose kinetics are given are photooxidized and the decay processes are dark reductions. These experiments are viewed as supporting and extending the concept of a bacterial photosynthetic unit, with energy migration within it to specific sites of electron transfer.

Kuntz, Irwin D.; Loach, Paul A.; Calvin, Melvin

1964-01-01

365

Small intestinal bacterial overgrowth syndrome.  

PubMed

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

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

2010-06-28

366

Bacterial sorption of heavy metals.  

PubMed Central

Four bacteria, Bacillus cereus, B. subtilis, Escherichia coli, and Pseudomonas aeruginosa, were examined for the ability to remove Ag+, Cd2+, Cu2+, and La3+ 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 Cd2+ and Cu2+, 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 Cd2+ removal and B. subtilis removed the most Cu2+. Removal of Ag+ from solution by bacteria was very efficient; an average of 89% of the total Ag+ was removed from the 1 mM solution, while only 12, 29, and 27% of the total Cd2+, Cu2+, and La3+, respectively, were sorbed from 1 mM solutions. Electron microscopy indicated that La3+ accumulated at the cell surface as needlelike, crystalline precipitates. Silver precipitated as discrete colloidal aggregates at the cell surface and occasionally in the cytoplasm. Neither Cd2+ nor Cu2+ provided enough electron scattering to identify the location of sorption. The affinity series for bacterial removal of these metals decreased in the order Ag greater than La greater than Cu greater than Cd. The results indicate that bacterial cells are capable of binding large quantities of different metals. Adsorption equations may be useful for describing bacterium-metal interactions with metals such as Cd and Cu; however, this approach may not be adequate when precipitation of metals occurs. Images

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

1989-01-01

367

Thiol dioxygenases: unique families of cupin proteins.  

PubMed

Proteins in the cupin superfamily have a wide range of biological functions in archaea, bacteria and eukaryotes. Although proteins in the cupin superfamily show very low overall sequence similarity, they all contain two short but partially conserved cupin sequence motifs separated by a less conserved intermotif region that varies both in length and amino acid sequence. Furthermore, these proteins all share a common architecture described as a six-stranded ?-barrel core, and this canonical cupin or "jelly roll" ?-barrel is formed with cupin motif 1, the intermotif region, and cupin motif 2 each forming two of the core six ?-strands in the folded protein structure. The recently obtained crystal structures of cysteine dioxygenase (CDO), with contains conserved cupin motifs, show that it has the predicted canonical cupin ?-barrel fold. Although there had been no reports of CDO activity in prokaryotes, we identified a number of bacterial cupin proteins of unknown function that share low similarity with mammalian CDO and that conserve many residues in the active-site pocket of CDO. Putative bacterial CDOs predicted to have CDO activity were shown to have similar substrate specificity and kinetic parameters as eukaryotic CDOs. Information gleaned from crystal structures of mammalian CDO along with sequence information for homologs shown to have CDO activity facilitated the identification of a CDO family fingerprint motif. One key feature of the CDO fingerprint motif is that the canonical metal-binding glutamate residue in cupin motif 1 is replaced by a cysteine (in mammalian CDOs) or by a glycine (bacterial CDOs). The recent report that some putative bacterial CDO homologs are actually 3-mercaptopropionate dioxygenases suggests that the CDO family may include proteins with specificities for other thiol substrates. A paralog of CDO in mammals was also identified and shown to be the other mammalian thiol dioxygenase, cysteamine dioxygenase (ADO). A tentative fingerprint motif for ADOs, or DUF1637 family members, is proposed. In ADOs, the conserved glutamate residue in cupin motif 1 is replaced by either glycine or valine. Both ADOs and CDOs appear to represent unique clades within the cupin superfamily. PMID:20195658

Stipanuk, Martha H; Simmons, Chad R; Karplus, P Andrew; Dominy, John E

2010-03-01

368

CAMPYLOBACTER JEJUNI: A MAJOR FOODBORNE BACTERIAL PATHOGEN  

Technology Transfer Automated Retrieval System (TEKTRAN)

Bacterial foodborne illnesses account for ~ 15 million cases, 60,000 hospitalizations and 1,800 deaths annually in the United States. Campylobacter jejuni is the major bacterial human foodborne pathogen and each year causes ~ 2 million cases, 300 deaths at an estimated cost of $1 billion in medical...

369

Bacterial Diversity within the Human Subgingival Crevice  

Microsoft Academic Search

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

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

1999-01-01

370

An Automated Bacterial Colony Counting System  

Microsoft Academic Search

Bacterial colony enumeration is an essential tool for many widely used biomedical assays. However, bacterial colony enumerating is a low throughput, time consuming and labor intensive process since there might exist hundreds or thousands of colonies on a Petri dish, and the counting process is often manually performed by well-trained technicians. In this paper, we introduce a fully automatic yet

Chengcui Zhang; Wei-bang Chen; Wen-lin Liu; Chi-bang Chen

2008-01-01

371

Differentiating bacterial from viral pneumonias in children  

Microsoft Academic Search

58 paediatric patients with pneumonia, in whom an etiological agent had been isolated, were reviewed. The patients were designated to have either viral or bacterial pneumonia on the basis of proposed clinical and radiological criteria. These presumed diagnoses were then compared to the microbiologically proven diagnosis. When clinical features suggested a bacterial infection the chance of isolating a bacteria as

F. A. L. Bettenay; J. F. de Campo; D. B. McCrossin

1988-01-01

372

Electrochemical characterization of the bacterial cell surface  

Microsoft Academic Search

Bacterial cells are ubiquitous in natural environments and also play important roles in domestic and industrial processes. They are found either suspended in the aqueous phase or attached to solid particles. The adhesion behaviour of bacteria is influenced by the physico-chemical properties of their cell surfaces, such as hydrophobicity and cell wall charge. The charge in the bacterial wall originates

Wal van der A

1996-01-01

373

Endovascular treatment of bacterial intracranial aneurysms  

Microsoft Academic Search

We report three patients with bacterial intracranial aneurysms treated by the endovascular approach: two presented with sudden severe neurological deficits after a diagnosis of endocarditis; the other had suspected vasculitis. CT showed an intracerebral haematoma in all cases: angiography revealed bacterial aneurysms of distal branches of the middle cerebral artery in two cases and posterior cerebral artery in one. Because

G. Scotti; M. H. Li; C. Righi; F. Simionato; A. Rocca

1996-01-01

374

Endovascular treatment of bacterial intracranial aneurysms  

Microsoft Academic Search

We report three patients with bacterial intracranial aneurysms treated by the endovascular approach: two presented with sudden severe neurological deficits after a diagnosis of endocarditis; the other had suspected vasculitis. CT showed an intracerebral haematoma in all cases; angiography revealed bacterial aneurysms of distal branches of the middle cerebral artery in two cases and posterior cerebral artery in one. Because

G. Scotti; M. H. Li; C. Righi; F. Simionato; A. Rocca

1996-01-01

375

Bacterial and viral infections associated with influenza.  

PubMed

Influenza-associated bacterial and viral infections are responsible for high levels of morbidity and death during pandemic and seasonal influenza episodes. A review was undertaken to assess and evaluate the incidence, epidemiology, aetiology, clinical importance and impact of bacterial and viral co-infection and secondary infection associated with influenza. A review was carried out of published articles covering bacterial and viral infections associated with pandemic and seasonal influenza between 1918 and 2009 (and published through December 2011) to include both pulmonary and extra-pulmonary infections. While pneumococcal infection remains the predominant cause of bacterial pneumonia, the review highlights the importance of other co- and secondary bacterial and viral infections associated with influenza, and the emergence of newly identified dual infections associated with the 2009 H1N1 pandemic strain. Severe influenza-associated pneumonia is often bacterial and will necessitate antibiotic treatment. In addition to the well-known bacterial causes, less common bacteria such as Legionella pneumophila may also be associated with influenza when new influenza strains emerge. This review should provide clinicians with an overview of the range of bacterial and viral co- or secondary infections that could present with influenza illness. PMID:24034494

Joseph, Carol; Togawa, Yu; Shindo, Nahoko

2013-09-01

376

Breakthroughs in field-scale bacterial transport  

SciTech Connect

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

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

2001-06-01

377

Bacterial Cellulose Production from Beet Molasses  

Microsoft Academic Search

Bacterial friendly cellulose is produced from beet molasses using Gluconacetobacter xylinus ATCC 10245. The yield of the bacterial cellulose (BC) produced from beet molasses was higher than that using glucose as a sole carbon source. The structure of BC produced in presence of beet molasses was studied using IR spectroscopy and X-ray diffractometry. IR spectra show the relative absorbance of

Sherif M. A. S. Keshk; Taha M. A. Razek; Kazuhiko Sameshima

2006-01-01

378

Bacterial Probiotic Modulation of Dendritic Cells  

Microsoft Academic Search

Intestinal dendritic cells are continually exposed to ingested microorganisms and high concentrations of endogenous bacterial flora. These cells can be activated by infectious agents and other stimuli to induce T-cell responses and to produce chemokines which recruit other cells to the local environment. Bacterial probiotics are of increasing use against intestinal disorders such as inflammatory bowel disease. They act as

Maureen Drakes; Thomas Blanchard; Steven Czinn

2004-01-01

379

Asymptomatic bacterial vaginosis: Response to therapy  

Microsoft Academic Search

Objective: Bacterial vaginosis causes symptomatic vaginal discharge and has been associated with preterm birth and with the acquisition of human immunodeficiency virus. Half of all women with bacterial vaginosis are free of symptoms, and treatment of these women is controversial. The objective of this study was to determine the extent of poor symptom recognition in this group of women. Study

Jane R. Schwebke

2000-01-01

380

Recent advances in bacterial heme protein biochemistry  

PubMed Central

Recent progress in genetics, fed by the burst in genome sequence data, has led to the identification of a host of novel bacterial heme proteins that are now being characterized in structural and mechanistic terms. The following short review highlights very recent work with bacterial heme proteins involved in the uptake, biosynthesis, degradation, and use of heme in respiration and sensing.

Mayfield, Jeffery A.; Dehner, Carolyn A.; DuBois, Jennifer L.

2011-01-01

381

Benthic bacterial diversity in submerged sinkhole ecosystems.  

PubMed

Physicochemical characterization, automated ribosomal intergenic spacer analysis (ARISA) community profiling, and 16S rRNA gene sequencing approaches were used to study bacterial communities inhabiting submerged Lake Huron sinkholes inundated with hypoxic, sulfate-rich groundwater. Photosynthetic cyanobacterial mats on the sediment surface were dominated by Phormidium autumnale, while deeper, organically rich sediments contained diverse and active bacterial communities. PMID:19880643

Nold, Stephen C; Pangborn, Joseph B; Zajack, Heidi A; Kendall, Scott T; Rediske, Richard R; Biddanda, Bopaiah A

2009-10-30

382

Family Interactions in Adoptive Compared to Nonadoptive Families  

Microsoft Academic Search

Despite the large and growing numbers of adoptive families, little research describes interactions in families with adopted adolescents. Yet, adopted adolescents' increased risk for adjustment problems, combined with the association between family interactions and adolescent adjustment in nonadoptive families, raises questions about differences in adoptive and nonadoptive family interactions. We compared observed and self-reported family interactions between 284 adoptive and

Martha A. Rueter; Margaret A. Keyes; William G. Iacono; Matt McGue

2009-01-01

383

Family Ties: Communicating Identity Through Jointly Told Family Stories  

Microsoft Academic Search

Family stories work to construct family identity. Little research, however, has examined storytelling in families. This study examined storytelling content and process to assess the extent to which families jointly integrated or fragmented a shared sense of identity and how these discursive practices relate to family qualities. Results of a study involving 58 family triads indicate relationships between story theme

Jody Koenig Kellas

2005-01-01

384

Family Interviews as a Method for Family Research  

Microsoft Academic Search

This paper is a description of the experience of conducting family interviews in a study to come to understand from families their experience of the hospitalization of a critically ill family member. Traditional family research has been done quantitatively, with a focus on the needs of individual family members rather than the family as a whole. The limited amount of

Sandra K. Eggenberger; Tommie P. Nelms

2007-01-01

385

Genetic Linkage Maps of the Red Flour Beetle, Tribolium castaneum, Based on Bacterial Artificial Chromosomes and Expressed Sequence Tags  

Microsoft Academic Search

A genetic linkage map was constructed in a backcross family of the red flour beetle, Tribolium castaneum, based largely on sequences from bacterial artificial chromosome (BAC) ends and untranslated regions from random cDNA's. In most cases, dimorphisms were detected using heteroduplex or single-strand conformational polymorphism analysis after specific PCR amplification. The map incorporates a total of 424 markers, including 190

Marce D. Lorenzen; Zaldy Doyungan; Joel Savard; Kathy Snow; Lindsey R. Crumly; Teresa D. Shippy; Jeffrey J. Stuart; Susan J. Brown; Richard W. Beeman

2005-01-01

386

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...

387

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

PubMed Central

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.

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

2011-01-01

388

Sharing of quorum-sensing signals and role of interspecies communities in a bacterial plant disease  

PubMed Central

Pathogenic bacteria interact not only with the host organism but most probably also with the resident microbial flora. In the knot disease of the olive tree (Olea europaea), the causative agent is the bacterium Pseudomonas savastanoi pv. savastanoi (Psv). Two bacterial species, namely Pantoea agglomerans and Erwinia toletana, which are not pathogenic and are olive plant epiphytes and endophytes, have been found very often to be associated with the olive knot. We identified the chemical signals that are produced by strains of the three species isolated from olive knot and found that they belong to the N-acyl-homoserine lactone family of QS signals. The luxI/R family genes responsible for the production and response to these signals in all three bacterial species have been identified and characterized. Genomic knockout mutagenesis and in planta experiments showed that virulence of Psv critically depends on QS; however, the lack of signal production can be complemented by wild-type E. toletana or P. agglomerans. It is also apparent that the disease caused by Psv is aggravated by the presence of the two other bacterial species. In this paper we discuss the potential role of QS in establishing a stable consortia leading to a poly-bacterial disease.

Hosni, Taha; Moretti, Chiaraluce; Devescovi, Giulia; Suarez-Moreno, Zulma Rocio; Fatmi, M' Barek; Guarnaccia, Corrado; Pongor, Sandor; Onofri, Andrea; Buonaurio, Roberto; Venturi, Vittorio

2011-01-01

389

Sharing of quorum-sensing signals and role of interspecies communities in a bacterial plant disease.  

PubMed

Pathogenic bacteria interact not only with the host organism but most probably also with the resident microbial flora. In the knot disease of the olive tree (Olea europaea), the causative agent is the bacterium Pseudomonas savastanoi pv. savastanoi (Psv). Two bacterial species, namely Pantoea agglomerans and Erwinia toletana, which are not pathogenic and are olive plant epiphytes and endophytes, have been found very often to be associated with the olive knot. We identified the chemical signals that are produced by strains of the three species isolated from olive knot and found that they belong to the N-acyl-homoserine lactone family of QS signals. The luxI/R family genes responsible for the production and response to these signals in all three bacterial species have been identified and characterized. Genomic knockout mutagenesis and in planta experiments showed that virulence of Psv critically depends on QS; however, the lack of signal production can be complemented by wild-type E. toletana or P. agglomerans. It is also apparent that the disease caused by Psv is aggravated by the presence of the two other bacterial species. In this paper we discuss the potential role of QS in establishing a stable consortia leading to a poly-bacterial disease. PMID:21677694

Hosni, Taha; Moretti, Chiaraluce; Devescovi, Giulia; Suarez-Moreno, Zulma Rocio; Fatmi, M' Barek; Guarnaccia, Corrado; Pongor, Sandor; Onofri, Andrea; Buonaurio, Roberto; Venturi, Vittorio

2011-06-16

390

Sensing bacterial infections by NAIP receptors in NLRC4 inflammasome activation.  

PubMed

The inflammasome is an emerging new pathway in innate immune defense against microbial infection or endogenous danger signals. The inflammasome stimulates activation of inflammatory caspases, mainly caspase-1. Caspase-1 activation is responsible for processing and secretion of IL-1? and IL-18 as well as for inducing macrophage pyroptotic death. Assembly of the large cytoplasmic inflammasome complex is thought to be mediated by members of NOD-like receptor (NLR) family. While functions of most of the NLR proteins remain to be defined, several NLR proteins including NLRC4 have been shown to assemble distinct inflammasome complexes. These inflammasome pathways, particularly the NLRC4 inflammasome, play a critical role in sensing and restricting diverse types of bacterial infections. Here we review recent advances in defining the exact bacterial ligands and the ligand-binding receptors involved in NLRC4 inflammasome activation. Implications of the discovery of the NAIP family of inflammasome receptors for bacterial flagellin and type III secretion apparatus on future inflammasome and bacterial infection studies are also discussed. PMID:22426978

Gong, Yi-Nan; Shao, Feng

2012-03-17

391

Family and migration.  

PubMed

This paper examines the effects of international migration on internal family structure, as well as the adaptation and integration of families into receiving countries. The importance of the role and function of the family in migration research can be examined from 3 angles: theoretical, methodological, and empirical (that is, the societal relevance of family in migration). A renewed theoretical perspective views the family in the sending country instead of the individual as the focus of attention, and reveals that 1) migration patterns are not exclusively among the poor or unemployed; 2) migration is not always for the benefit of the immigrant; and 3) migration should be studied as a process, not as a result. Recent studies show that 1) family or kinship migration is increasingly important and that families help new migrants adapt to the receiving country, both emotionally and financially; 2) family and kinship ties tend to become consolidated in the receiving country; and 3) the family helps migrants cope with stress caused by the migration experience. Studies on families' preservation of culture and adaptation of culture and behavior have gone from 1) descriptive to analytical and, 2) focusing on the receiving society to focusing on the strategies used by immigrants (from value-conformity to an individualistic-situation approach). Migration also causes changes in family organization and functioning, which should be studied as an internal process inside the family and as complex group. Within the family are 3 sets of substructures which change during the process of adaptation and/or assimilation to/into the receiving society: 1) the husband-wife relationship, 2) the parent-child relationship, and 3) the relationship among siblings. PMID:12315897

Dumon, W A

1989-06-01

392

Metallization of Bacterial Cellulose for Electrical and Electronic Device Manufacture.  

National Technical Information Service (NTIS)

A method for the deposition of metals in bacterial cellulose and for the employment of the metallized bacterial cellulose in the construction of fuel cells and other electronic devices is disclosed. The method for impregnating bacterial cellulose with a m...

B. R. Evans H. M. O'Neill J. Woodward V. M. Jansen

2005-01-01

393

Bacterial chromosome segregation: structure and DNA binding of the Soj dimer ? a conserved biological switch  

Microsoft Academic Search

Soj and Spo0J of the Gram-negative hyperthermophile Thermus thermophilus belong to the conserved ParAB family of bacterial proteins implicated in plasmid and chromosome partitioning. Spo0J binds to DNA near the replication origin and localises at the poles following initiation of replication. Soj oscillates in the nucleoid region in an ATP- and Spo0J-dependent fashion. Here, we show that Soj undergoes ATP-dependent

Thomas A Leonard; P Jonathan Butler

2005-01-01

394

Isolation and Characterization of a Fucoidan-Degrading Marine Bacterial Strain and Its Fucoidanase  

Microsoft Academic Search

A marine bacterial strain that degraded fucoidan from Kjellmaniella crassifolia (class Phaeophyceae, order Laminariales, family Laminariaceae) was isolated in our laboratory. The strain was gram-negative, ubiquinone 8 was the predominant respiratory quinone, and the GC-content of its genomic DNA was 36%. The cells of the strain were rod-shaped (2.0 ?m long × 1.0 ?m wide), and each cell was motile by means

Takeshi Sakai; Takashi Kawai; Ikunoshin Kato

2004-01-01

395

Functional Family Therapy  

Microsoft Academic Search

\\u000a Functional Family Therapy (FFT) is all about helping youth and families who are in trouble. Central to FFT is the belief this\\u000a can be accomplished by changing family interactions and improving relationship functioning as the primary vehicle for changing\\u000a dysfunctional individual behaviors. FFT shares many similarities with other systems approaches; however, FFT offers a comprehensive\\u000a framework for understanding adolescent behavior

James F. Alexander; Michael S. Robbins

396

Family history assessment  

Microsoft Academic Search

Family history assessment can be used to combine population-wide health promotion and risk-reduction efforts with a high-risk, targeted approach to help reduce the burden of cardiovascular disease (CVD). Family history is an independent predictor of CVD, and the upper portion of the family history distribution explains a larger fraction of CVD in the population than can be explained by extreme

Steven C Hunt; Marta Gwinn; Ted D Adams

2003-01-01

397

Familial dysalbuminaemic hyperthyroxinaemia.  

PubMed Central

Familial dysalbuminaemic hyperthyroxinaemia (FDH) can be confused with thyrotoxicosis if clinical signs and laboratory tests are misinterpreted. We describe three members of the same family with FDH who were erroneously treated for thyrotoxicosis. Screening of other family members resulted in the discovery of a further six patients at risk of being misdiagnosed as thyrotoxic. Clinical and biochemical findings relevant to the diagnosis of FDH are discussed.

Fleming, S. J.; Applegate, G. F.; Beardwell, C. G.

1987-01-01

398

Households and Families  

NSDL National Science Digital Library

The US Census Bureau has released a report which demonstrates that "traditional families" (married couples with children) have begun to stabilize as a percentage of all families in the 1990s, and the growth of single-parent families has slowed. Most of the information in the report comes from the March 1997 Current Population Survey. Users may download the full report as well as detailed tables in .pdf format.

Bryson, Ken.; Caspar, Lynne M.

1998-01-01

399

Family intervention in schizophrenia  

Microsoft Academic Search

.   Background: This study focuses on the effect of psycho-educative family therapy on the self-assessed burden in families in which one\\u000a member has suffered from relapse of schizophrenia or a schizoaffective syndrome. The impact on the family's self-assessed\\u000a attitude towards continuing to take care of the patient was also evaluated. Burden and attitude were assessed continuously\\u000a during a period that

Nils Berglund; Ĺke Edman

2003-01-01

400

Homeownership and family formation  

Microsoft Academic Search

In Western countries, home-ownership and family formation are closely connected. From most research on the transition to home-ownership, one gets the impression that the association between family formation and home-ownership is positive: family formation seems to speed up the process of acquiring a home in several countries. However, it has also been argued that there might be a negative association

Clara H. Mulder

2006-01-01

401

Family Bonding with Universities  

Microsoft Academic Search

One justification offered for legacy admissions policies at universities is that that they bind entire families to the university.\\u000a Proponents maintain that these policies have a number of benefits, including increased donations from members of these families.\\u000a We use a rich set of data from an anonymous selective research institution to investigate which types of family members have\\u000a the most

Jonathan MeerHarvey; Harvey S. Rosen

2010-01-01

402

Traditional Family Values  

Microsoft Academic Search

\\u000a What is “traditionalism” and how does it relate to family values? What are the family values that concern parental responsibility\\u000a in raising children? Who do the Puerto Ricans say should be the decision maker in the family? Should women with small children\\u000a work outside the home? Should husbands share responsibility for housework? Should a wife always obey her husband? Should

Mary Cuadrado; Louis Lieberman

403

Supporting Family Choice  

Microsoft Academic Search

Supporting family choice in the decision-making process is recommended practice in the field of early childhood and early\\u000a childhood special education. These decisions may relate to the medical, educational, social, recreational, therapeutic\\/rehabilitative,\\u000a and community aspects of the child's disability. Although this practice conveys the message that families are the primary\\u000a decision-makers for their children, families are not always adequately supported

Mary M. Murray; Kimberly A. Christensen; Gardner T. Umbarger; Karin C. Rade; Kathryn Aldridge; Judith A. Niemeyer

2007-01-01

404

Species sorting and neutral processes are both important during the initial assembly of bacterial communities  

PubMed Central

Many studies have shown that species sorting, that is, the selection by local environmental conditions is important for the composition and assembly of bacterial communities. On the other hand, there are other studies that could show that bacterial communities are neutrally assembled. In this study, we implemented a microcosm experiment with the aim to determine, at the same time, the importance of species sorting and neutral processes for bacterial community assembly during the colonisation of new, that is, sterile, habitats, by atmospheric bacteria. For this we used outdoor microcosms, which contained sterile medium from three different rock pools representing different environmental conditions, which were seeded by rainwater bacteria. We found some evidence for neutral assembly processes, as almost every 4th taxon growing in the microcosms was also detectable in the rainwater sample irrespective of the medium. Most of these taxa belonged to widespread families with opportunistic growth strategies, such as the Pseudomonadaceae and Comamonadaceae, indicating that neutrally assembled taxa may primarily be generalists. On the other hand, we also found evidence for species sorting, as one out of three media selected a differently composed bacterial community. Species sorting effects were relatively weak and established themselves via differences in relative abundance of generalists among the different media, as well as media-specific occurrences of a few specific taxa. In summary, our results suggest that neutral and species sorting processes interact during the assembly of bacterial communities and that their importance may differ depending on how many generalists and specialists are present in a community.

Langenheder, Silke; Szekely, Anna J

2011-01-01

405

Familial Transient Global Amnesia  

PubMed Central

Following an episode of typical transient global amnesia (TGA), a female patient reported similar clinical attacks in 2 maternal aunts. Prior reports of familial TGA are few, and no previous account of affected relatives more distant than siblings or parents was discovered in a literature survey. The aetiology of familial TGA is unknown. A pathophysiological mechanism akin to that in migraine attacks, comorbidity reported in a number of the examples of familial TGA, is one possibility. The study of familial TGA cases might facilitate the understanding of TGA aetiology.

Davies, R. Rhys; Larner, A.J.

2012-01-01

406

Familial achalasia in children.  

PubMed

Achalasia is rare in the pediatric age group and in most cases it is idiopathic with no family history. Familial achalasia is very rare. This report describes two families with achalasia: in one, six children were affected while in the other a brother and a sister had Allgrove's syndrome (triple-A syndrome consisting of achalasia, adrenal insufficiency, and alacrima). Familial achalasia suggests that it is hereditary and may be transmitted as an autosomal recessive trait. The management of achalasia in children is still controversial. With the recent advances in minimal invasive surgery, laparoscopic Heller's myotomy is the procedure of choice in the management of achalasia in children. PMID:23076455

Torab, Fawaz Chikh; Hamchou, Moustafa; Ionescu, Gabriel; Al-Salem, Ahmed H

2012-10-18

407

Pathogenesis and pathophysiology of bacterial meningitis.  

PubMed Central

Bacterial meningitis remains a disease with associated unacceptable morbidity and mortality rates despite the availability of effective bactericidal antimicrobial therapy. Through the use of experimental animal models of infection, a great deal of information has been gleaned concerning the pathogenic and pathophysiologic mechanisms operable in bacterial meningitis. Most cases of bacterial meningitis begin with host acquisition of a new organism by nasopharyngeal colonization followed by systemic invasion and development of a high-grade bacteremia. Bacterial encapsulation contributes to this bacteremia by inhibiting neutrophil phagocytosis and resisting classic complement-mediated bactericidal activity. Central nervous system invasion then occurs, although the exact site of bacterial traversal into the central nervous system is unknown. By production and/or release of virulence factors into and stimulation of formation of inflammatory cytokines within the central nervous system, meningeal pathogens increase permeability of the blood-brain barrier, thus allowing protein and neutrophils to move into the subarachnoid space. There is then an intense subarachnoid space inflammatory response, which leads to many of the pathophysiologic consequences of bacterial meningitis, including cerebral edema and increased intracranial pressure. Attenuation of this inflammatory response with adjunctive dexamethasone therapy is associated with reduced concentrations of tumor necrosis factor in the cerebrospinal fluid, with diminished cerebrospinal fluid leukocytosis, and perhaps with improvement of morbidity, as demonstrated in recent clinical trials. Further information on the pathogenesis and pathophysiology of bacterial meningitis should lead to the development of more innovative treatment and/or preventive strategies for this disorder. Images

Tunkel, A R; Scheld, W M

1993-01-01

408

Conformational plasticity and ligand binding of bacterial monoacylglycerol lipase.  

PubMed

Monoacylglycerol lipases (MGLs) play an important role in lipid catabolism across all kingdoms of life by catalyzing the release of free fatty acids from monoacylglycerols. The three-dimensional structures of human and a bacterial MGL were determined only recently as the first members of this lipase family. In addition to the ?/?-hydrolase core, they showed unexpected structural similarities even in the cap region. Nevertheless, the structural basis for substrate binding and conformational changes of MGLs is poorly understood. Here, we present a comprehensive study of five crystal structures of MGL from Bacillus sp. H257 in its free form and in complex with different substrate analogs and the natural substrate 1-lauroylglycerol. The occurrence of different conformations reveals a high degree of conformational plasticity of the cap region. We identify a specific residue, Ile-145, that might act as a gatekeeper restricting access to the binding site. Site-directed mutagenesis of Ile-145 leads to significantly reduced hydrolase activity. Bacterial MGLs in complex with 1-lauroylglycerol, myristoyl, palmitoyl, and stearoyl substrate analogs enable identification of the binding sites for the alkyl chain and the glycerol moiety of the natural ligand. They also provide snapshots of the hydrolytic reaction of a bacterial MGL at different stages. The alkyl chains are buried in a hydrophobic tunnel in an extended conformation. Binding of the glycerol moiety is mediated via Glu-156 and water molecules. Analysis of the structural features responsible for cap plasticity and the binding modes of the ligands suggests conservation of these features also in human MGL. PMID:24014019

Rengachari, Srinivasan; Aschauer, Philipp; Schittmayer, Matthias; Mayer, Nicole; Gruber, Karl; Breinbauer, Rolf; Birner-Gruenberger, Ruth; Dreveny, Ingrid; Oberer, Monika

2013-09-06

409

Structural and biochemical analysis of a bacterial glycosyltransferase.  

PubMed

Glycosyltransferases (GTs) are a large family of enzymes that specifically transfer sugar moieties to a diverse range of substrates. The process of bacterial glycosylation (such as biosynthesis of glycolipids, glycoproteins, and polysaccharides) has been studied extensively, yet the majority of GTs involved remains poorly characterized. Besides predicting enzymatic parameters of GTs, the resolution of three-dimensional structures of GTs can help to determine activity, donor sugar binding, and acceptor substrate binding sites. It also facilitates amino acid sequence-based structural modeling and biochemical characterization of their homologues. Here we describe a general procedure to accomplish expression and purification of soluble and active recombinant GTs. Enzymatic characterization, and crystallization of GTs, and data refinement for structural analysis are also covered in this protocol. PMID:23765651

Zhu, Fan; Wu, Ren; Zhang, Hua; Wu, Hui

2013-01-01

410

Tobacco use increases susceptibility to bacterial infection  

PubMed Central

Active smokers and those exposed to secondhand smoke are at increased risk of bacterial infection. Tobacco smoke exposure increases susceptibility to respiratory tract infections, including tuberculosis, pneumonia and Legionnaires disease; bacterial vaginosis and sexually transmitted diseases, such as chlamydia and gonorrhoea; Helicobacter pylori infection; periodontitis; meningitis; otitis media; and post-surgical and nosocomial infections. Tobacco smoke compromises the anti-bacterial function of leukocytes, including neutrophils, monocytes, T cells and B cells, providing a mechanistic explanation for increased infection risk. Further epidemiological, clinical and mechanistic research into this important area is warranted.

Bagaitkar, Juhi; Demuth, Donald R; Scott, David A

2008-01-01

411

Bacterial pericarditis caused by infected trichilemmal cyst.  

PubMed

Bacterial pericarditis is a well-known although rare complication of Staphylococcus aureus infection in modern practice. We present a rare case of Staphylococcus pericarditis caused by an infected trichilemmal cyst present on patient's scalp. Our case emphasizes that all cases of bacterial pericarditis should be thoroughly investigated for a source of infection. Constrictive changes can be seen in the pericardium postinfection, as in our patient, and should be treated aggressively. To our knowledge, a case of an infected cyst causing bacterial pericarditis has never been reported previously in the literature. PMID:21915636

Lodha, Ankur; Enakpene, Evbu; Haran, Mehandi; Sadiq, Adnan; Shani, Jacob

2011-09-14

412

Response rescaling in bacterial chemotaxis.  

PubMed

Sensory systems rescale their response sensitivity upon adaptation according to simple strategies that recur in processes as diverse as single-cell signaling, neural network responses, and whole-organism perception. Here, we study response rescaling in Escherichia coli chemotaxis, where adaptation dynamically tunes the cells' motile response during searches for nutrients. Using in vivo fluorescence resonance energy transfer (FRET) measurements on immobilized cells, we demonstrate that the design of this prokaryotic signaling network follows the fold-change detection (FCD) strategy, responding faithfully to the shape of the input profile irrespective of its absolute intensity. Using a microfluidics-based assay for free swimming cells, we confirm intensity-independent gradient responses at the behavioral level. By theoretical analysis, we identify a set of sufficient conditions for FCD in E. coli chemotaxis, which leads to the prediction that the adaptation timescale is invariant with respect to the background input level. Additional FRET experiments confirm that the adaptation timescale is invariant over an ?10,000-fold range of background concentrations. These observations in a highly optimized bacterial system support the concept that FCD represents a robust sensing strategy for spatial searches. To our knowledge, these experiments provide a unique demonstration of FCD in any biological sensory system. PMID:21808031

Lazova, Milena D; Ahmed, Tanvir; Bellomo, Domenico; Stocker, Roman; Shimizu, Thomas S

2011-08-01

413

Bacterial sorption of heavy metals  

SciTech Connect

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.

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

1989-01-01

414

Gut bacterial microbiota and obesity.  

PubMed

Although probiotics and antibiotics have been used for decades as growth promoters in animals, attention has only recently been drawn to the association between the gut microbiota composition, its manipulation, and obesity. Studies in mice have associated the phylum Firmicutes with obesity and the phylum Bacteroidetes with weight loss. Proposed mechanisms linking the microbiota to fat content and weight include differential effects of bacteria on the efficiency of energy extraction from the diet, and changes in host metabolism of absorbed calories. The independent effect of the microbiota on fat accumulation has been demonstrated in mice, where transplantation of microbiota from obese mice or mice fed western diets to lean or germ-free mice produced fat accumulation among recipients. The microbiota can be manipulated by prebiotics, probiotics, and antibiotics. Probiotics affect the microbiota directly by modulating its bacterial content, and indirectly through bacteriocins produced by the probiotic bacteria. Interestingly, certain probiotics are associated with weight gain both in animals and in humans. The effects are dependent on the probiotic strain, the host, and specific host characteristics, such as age and baseline nutritional status. Attention has recently been drawn to the association between antibiotic use and weight gain in children and adults. We herein review the studies describing the associations between the microbiota composition, its manipulation, and obesity. PMID:23452229

Million, M; Lagier, J-C; Yahav, D; Paul, M

2013-03-02

415

Pyrones as bacterial signaling molecules.  

PubMed

Bacteria communicate via small diffusible molecules and thereby mediate group-coordinated behavior, a process referred to as quorum sensing. The prototypical quorum sensing system found in Gram-negative bacteria consists of a LuxI-type autoinducer synthase that produces N-acyl homoserine lactones (AHLs) as signals and a LuxR-type receptor that detects the AHLs to control expression of specific genes. However, many proteobacteria have proteins with homology to LuxR receptors yet lack any cognate LuxI-like AHL synthase. Here we show that in the insect pathogen Photorhabdus luminescens the orphan LuxR-type receptor PluR detects endogenously produced ?-pyrones that serve as signaling molecules at low nanomolar concentrations. Additionally, the ketosynthase PpyS was identified as pyrone synthase. Reconstitution of the entire system containing PluR, the PluR-target operon we termed pcf and PpyS in Escherichia coli demonstrated that the cell-cell communication circuit is portable. Our research thus deorphanizes a signaling system and suggests that additional modes of bacterial communication may await discovery. PMID:23851573

Brachmann, Alexander O; Brameyer, Sophie; Kresovic, Darko; Hitkova, Ivana; Kopp, Yannick; Manske, Christian; Schubert, Karin; Bode, Helge B; Heermann, Ralf

2013-07-14

416

THE ETIOLOGY OF BACTERIAL VAGINOSIS  

PubMed Central

Bacterial vaginosis (BV) is the most common vaginal infection among women of childbearing age. This condition is notorious for causing severe complications related to the reproductive health of women. Five decades of intense research established many risk factors for acquisition of BV, however due to the complexity of BV and due to lack of a reliable animal model for this condition, its exact etiology remains elusive. In this manuscript we use a historical perspective to critically review the development of major theories on the etiology of BV, ultimately implicating BV-related pathogens, healthy vaginal microbiota, bacteriophages and the immune response of the host. None of these theories on their own can reliably explain the epidemiological data. Instead, BV is caused by a complex interaction of multiple factors, which include the numerous components of the vaginal microbial ecosystem and their human host. Many of these factors are yet to be characterized because a clear understanding of their relative contribution to the etiology of BV is pivotal to formulation of an effective treatment for and prophylaxis of this condition.

Turovskiy, Yevgeniy; Noll, Katia Sutyak; Chikindas, Michael L.

2011-01-01

417

Bacterial pneumonia in the elderly.  

PubMed

Bacterial pneumonia in the elderly is common, and causes more morbidity and mortality than in the younger adult. As patients live longer with more underlying disease and more iatrogenic disease, the incidence of nosocomial pneumonia will probably rise. Adequate sterilization of inhalation therapy equipment can reduce the risk of gram-negative nosocomial pneumonia. Methods to prevent colonization and microaspiration need to be investigated. The development of a gram-negative vaccine using Salmonella RE or E. coli J5 mutant would augur well for the future. Most important, the elderly patient with pneumonia should be managed promptly and aggressively in an attempt to determine the specific etiology of the pneumonia. The practice of antibiotic "shotgunning" of the elderly patient is to be avoided. Transtracheal aspiration or sheathed bronchoscopy can be performed if the patient is not able to produce sputum, or Gram stain is difficult to interpret. Morbidity and mortality can be reduced by early appropriate antibiotic therapy directed by Gram stain. PMID:6353130

Verghese, A; Berk, S L

1983-09-01

418

Ethanol production by bacterial fermentation  

SciTech Connect

The goal of this study is to develop and optimize the process technology for the production of ethanol using the bacteria Zymomonas mobilis. Specifically, the process and operating conditions will be studied to maximize the yield of ethanol. The experimental design is described using both batch and continuous cultures with glucose as the substrate. Separation methods, therefore, will be developed to remove the alcohol from the fermentation media to prevent the inhibitory effects of ethanol on Z. mobilis. Vacuum fermentation and solvent extraction can be used to separate the alcohol from the media. Kinetic data will be obtained from both the batch and continuous fermentors. The kinetic data can be correlated using mathematical models. Mathematical models for Z. mobilis will be developed for the effect of pH, temperature and nutrient composition on the specific growth rate. A model will also be developed to account for the possible product inhibition by ethanol. Dynamic tests will also be conducted on the continuous system to determine how fast the fermentation will respond to environmental changes. The simultaneous hydrolysis of cellulose to glucose and fermentation of glucose to ethanol is one of the most exciting possibilities. A literature survey will be made to determine the compatibility of conducting the hydrolysis reaction along with the bacterial fermentation. The final objective will be to make an economic assessment of the process of producing ethanol using Z. mobilis.

King, F.G.

1985-01-01

419

Molecular biology of bacterial bioluminescence.  

PubMed Central

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

Meighen, E A

1991-01-01

420

Opening Doors: Understanding School and Family Influences on Family Involvement  

Microsoft Academic Search

Family involvement in schooling can benefit young children, teachers, and families. Family involvement in schools can be influenced by both school-related and family-related factors. School-related factors include teachers’ attitudes toward families, and school and teacher expectations. Family-related factors include ethnicity, prior school experiences, and family work schedules. Teachers who recognize and understand these influences can employ a variety of strategies

Erin Carlisle; Lindsey Stanley; Kristen Mary Kemple

2005-01-01

421

Family governance practices and teambuilding: paradox of the enterprising family  

Microsoft Academic Search

This paper explores the relationship between family governance practices and financial performance of the business and family\\u000a assets of business-owning families. A business-owning family that shares a focus on preserving and growing wealth as a family\\u000a is defined as the enterprising family. Results of the study are consistent with predictions about the functioning of the enterprising family derived from research

Marta M. Berent-BraunLorraine; Lorraine M. Uhlaner

2012-01-01

422

Xa3 , conferring resistance for rice bacterial blight and encoding a receptor kinase-like protein, is the same as Xa26  

Microsoft Academic Search

Xa3-mediated resistance for rice bacterial blight, one of the most devastating rice diseases worldwide, is influenced by genetic background. Xa3 is genetically tightly linked to Xa26, another gene for bacterial blight resistance. Xa26 belongs to a clustered multigene family encoding leucine-rich repeat (LRR) receptor kinase-like proteins. To characterize Xa3, we fine mapped it using a population segregating for only one

Yi Xiang; Yinglong Cao; Caiguo Xu; Xianghua Li; Shiping Wang

2006-01-01

423

Family Nursing Research with Asian Families  

Microsoft Academic Search

The purpose of this article is to review nursing research with Asian families over the past decade to understand the state of the science and recommend future directions for nursing research. Between 1992 and 2002, 68 databased articles published in English and authored by a nurse were examined for study settings, populations, methods, and findings. The current body of literature

Mayumi A. Willgerodt; Marcia G. Killien

2004-01-01

424

IGSF9 family proteins.  

PubMed

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

Hansen, Maria; Walmod, Peter Schledermann

2013-02-16

425

Ontogeny in the Family  

Microsoft Academic Search

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

Mathias Kölliker

2005-01-01

426

Balancing Work & Family.  

ERIC Educational Resources Information Center

This curriculum is based on what students need to know, to be able to do, and to be like in order to be competent in the work of the family. Each of the 12 units follows a uniform format that includes the following: perennial problem (one faced over and over by successive generations of families); practical problem (the organizing scheme for how…

Hutchinson Community Junior Coll., KS.

427

Patent Family Databases.  

ERIC Educational Resources Information Center

|Reports on retrieval of patent information online and includes definition of patent family, basic and equivalent patents, "parents and children" applications, designated states, patent family databases--International Patent Documentation Center, World Patents Index, APIPAT (American Petroleum Institute), CLAIMS (IFI/Plenum). A table noting…

Simmons, Edlyn S.

1985-01-01

428

Changing Families, Changing Workplaces  

ERIC Educational Resources Information Center

|American families and workplaces have both changed dramatically over the past half-century. Paid work by women has increased sharply, as has family instability. Education-related inequality in work hours and income has grown. These changes, says Suzanne Bianchi, pose differing work-life issues for parents at different points along the income…

Bianchi, Suzanne M.

2011-01-01

429

Genetics & Family History  

Cancer.gov

In 2001 we conducted the Family History Validation Study, a telephone survey of 1,380 Connecticut residents, which assessed self-reported information about family history of cancer. The study also explored demographic, psychosocial, and medical factors associated with such reports.

430

Family-Friendly Art  

ERIC Educational Resources Information Center

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…

Williams, Patterson; Garcia, Maria

2004-01-01

431

Marinating the Family.  

ERIC Educational Resources Information Center

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)

Hensel, Karen A.

1982-01-01

432

THE FAMILY ALBUM  

Microsoft Academic Search

This article introduces a creative diagnostic tool, developed and clinically applied by the authors in individual, marital, and family therapy. The tool is based on the clients' creation of a family album in the form of a collage, and it enables the therapist to touch the inner (intrapsychic) theater of the client, as well as to understand the interpersonal theater.

Hassia Yerushalmi; Tova Yedidya

1997-01-01

433

Asteroid families: Current situation  

Microsoft Academic Search

Being the products of energetic collisional events, asteroid families provide a fundamental body of evidence to test the predictions of theoretical and numerical models of catastrophic disruption phenomena. The goal is to obtain, from current physical and dynamical data, reliable inferences on the original disruption events that produced the observed families. The main problem in doing this is recognizing, and

A. Cellino; A. Dell'Oro; E. F. Tedesco

2009-01-01

434

Uninsured Rural Families  

ERIC Educational Resources Information Center

|Context: Although research shows higher uninsured rates among rural versus urban individuals, prior studies are limited because they do not examine coverage across entire rural families. Purpose: This study uses the Medical Expenditure Panel Survey (MEPS) to compare rural and urban insurance coverage within families, to inform the design of…

Ziller, Erika C.; Coburn, Andrew F.; Anderson, Nathaniel J.; Loux, Stephenie L.

2008-01-01

435

Family Perspectives on Prematurity  

ERIC Educational Resources Information Center

|In this article, seven families describe their experiences giving birth to and raising a premature baby. Their perspectives vary, one from another, and shift over time, depending on each family's circumstances and the baby's developmental course. Experiences discussed include premature labor, medical interventions and the NICU, bringing the baby…

Zero to Three (J), 2003

2003-01-01

436

Families living with HIV  

Microsoft Academic Search

Given the historical emergence of the AIDS epidemic first among gay men in the developed world, HIV interventions have primarily focused on individuals rather than families. Typically not part of traditional family structures, HIV-positive gay men in Europe and the US lived primarily in societies providing essential infrastructure for survival needs that highly value individual justice and freedom. Interventions were

M. J. Rotheram-Borus; D. Flannery; E. Rice; P. Lester

2005-01-01

437

Families, Risk, and Competence.  

ERIC Educational Resources Information Center

|The problems of studying families arise from the difficulty in studying systems in which there are multiple elements interacting with each other and with the child. This book attests to the growing sophistication of the conceptualization and measurement techniques for understanding family processes. Chapters in the first part of the book, "The…

Lewis, Michael, Ed.; Feiring, Candice, Ed.

438

Therapy for Family Systems.  

ERIC Educational Resources Information Center

|A family therapy model, based on a conceptualization of the family as a behavioral system whose members interact adaptively so that an optimal level of functioning is maintained within the system, is described. The divergent roots of this conceptualization are discussed briefly, as are the treatment approaches based on it. The author's model,…

Rosmann, Michael R.

439

Explaining Family Interactions.  

ERIC Educational Resources Information Center

|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…

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

440

Feminism and family therapy.  

PubMed

Feminism has had a profound effect on contemporary culture and on thinking in most academic fields, including psychoanalysis. Interestingly, until very recently it had made virtually no impact on the theory and practice of family therapy. This paper proposes an explanation for this peculiar phenomenon and argues that family therapy has been considerably handicapped by its insularity from the feminist critique. Utilizing feminist scholarship in psychoanalysis, history, and sociology, the paper analyzes the structural contradictions in family life that family therapists have essentially ignored and then outlines their clinical implications. Key points in the discussion include the argument that systems theory is an inadequate explanatory matrix from which to build a theory of the family, that the archetypal "family case" of the overinvolved mother and peripheral father is best understood, not as a clinical problem, but as the product of a historical process two hundred years in the making, and that power relations between men and women in families function in terms of paradoxical, incongruous hierarchies that reflect the complex interpenetration between the structure of family relations and the world of work. This conceptual model then provides the basis for an analysis and critique of sexual politics as they emerge in the prototypical clinical situation. PMID:3987881

Goldner, V

1985-03-01

441

Knowledge and the Family  

Microsoft Academic Search

We …nd a connection betweeen the logistic learning curves in experi- mentally psychology, and the changing division of labor within the family. A two equation model explains how humans organize their activities both inside and outside the family. The model predicts that in the beginning convex part of the logistic curve it is e˘ cient for unskilled men and women

Graciela Chichilnisky; Peter Eisenberger

442

Home and Family Life.  

ERIC Educational Resources Information Center

|The "Goldfinch" is a magazine that introduces children to different aspects of Iowa History. Each issue contains articles to provide in-depth knowledge of a topic about Iowa. The focus of this issue is homes and family life in Iowa history. Selections address what has been important to Iowa's families over time and what homes were like before…

Frese, Millie K., Ed.

1996-01-01

443

Immigrant Family Stability  

Microsoft Academic Search

The intent of this paper is to examine aspects of the immigration experience that impinge on the issue of family stability. The meager literature on the socioeconomic background of recent immigrants together with data collected on 150 recent immigrant families indicates that the newest wave of immigrants is, in general, well-prepared for life in the United States. However, the process

Geraldine Grant

1983-01-01

444

Firearms and family violence.  

PubMed

Firearms contribute significantly to morbidity and mortality in family violence. This article discusses the debate on gun use for protection and guns in the home. Weapons-related risks in the setting of intimate partner violence are closely reviewed. Recommendations for physicians are discussed in the context of firearms and family violence. PMID:10516848

Kellermann, A; Heron, S

1999-08-01

445

Snowbird Intergenerational Family Relationships  

Microsoft Academic Search

This qualitative study examined the family relationships of snowbirds. Interviews were conducted with 25 older adults from the Midwest who migrated seasonally to the Sunbelt. Snowbirds did not perceive their winter experience as having a negative impact on their families in any significant way. The vast majority of snowbirds expressed satisfaction with how well they maintained their intergenerational ties and

Kristine E. Bjelde; Gregory F. Sanders

2009-01-01

446

Understanding family values  

Microsoft Academic Search

Explores how the traditional nuclear family of mother, father and 2 children is being replaced by “beanpole“ families of cohabitating couples with one child, and extending to four rather than three generations; parents have children at a later age and seek to recreate their own childhood by imitating the styles of their children. Discusses the accompanying end of childhood, as

Tim Greenhalgh

2002-01-01

447

Families in the Military  

MedlinePLUS

... and anxious. They may also experience financial stress. Media coverage of events can also increase concern. Some families must also deal with the ... yrs.) may be rebellious, irritable or more challenging of authority. Parents need to ... assignment increases the burden on all family members. The following ...

448

Intervention in Disintegrating Families.  

ERIC Educational Resources Information Center

A special demonstration project attempted to find means of assisting hard-core multi-problem families in a predominantly rural Idaho county. A single agency was formed to coordinate community activities and provide a variety of services for the needs of the total family. Project personnel included a director, social worker, home economist, public…

Wootton, Ray W.

449

Abstract Families of Processors.  

National Technical Information Service (NTIS)

A 'processor' is a Turing-like automaton with auxiliary storage. An 'abstract family' of processors (AFP) consists of all processors that use the storage in the same way. Properties common to all AFP are derived. For a family of operations to be the outpu...

G. F. Rose

1968-01-01

450

THE FAMILY TYMOVIRIDAE  

Technology Transfer Automated Retrieval System (TEKTRAN)

The family Tymoviridae comprises the genus Tymovirus, from which it derives its name, the genus Marafivirus and the newly established genus Maculavirus. Members of the family share the following characteristics: (i) non enveloped isometric particles c. 30 nm in diameter, with a rounded contour and...

451

Family Influence on Reading.  

ERIC Educational Resources Information Center

|No one denies that students have many more distractions today than in days gone by. The need for family involvement in a child's reading progress joins a surge in American society for parents to take more responsibility for their children's character and in the condition of their communities. Some hints for parents in establishing family literacy…

Walker, Scott S.

452

Education and the Family.  

ERIC Educational Resources Information Center

|This book is the report of the Family Ties Commission, which was established by the Association of Teacher Educators to study the relationship between home and school. Following the preface and two introductory essays, "Education and My Family" (K.B. O'Rourke as told to E. Johnson) and "Preparing for Successful Children" (B. Clawson), the book is…

Kaplan, Leonard, Ed.

453

Family Reunification Project.  

ERIC Educational Resources Information Center

Utah's Department of Human Services' Family Reunification Project was initiated to demonstrate that intensive, time-limited, home-based services would enable children in foster care to return to their natural families more rapidly than regular foster care management permits. The following steps were taken in project development: (1) sites were…

Administration for Children, Youth, and Families (DHHS), Washington, DC.

454

Effective family problem solving.  

PubMed

Effective family problem solving was studied in 97 families of elementary-school-aged children, with 2 definite-solution tasks--tower building (TWB) and 20 questions (TQ), and 1 indefinite-solution task--plan-something-together (PST). Incentive (for cooperation or competition) and task independence (members worked solo or jointly) were manipulated during TWB and TQ, yielding 4 counterbalanced conditions per task per family. On TQ, solo performance exceeded joint performance; on TWB, competition impaired joint performance. Families effective at problem solving in all conditions of both definite-solution tasks tried more problem-solving strategies during TWB and deliberated longer and reached more satisfactory agreements during PST. Family problem-solving effectiveness was moderately predicted by 2 parents' participation in the study. Parental education, parental occupational prestige, and membership in the family of an academically and socially competent child were weaker predictors. The results indicate that definitions of effective family problem solving that are based on directly observed measures of group interaction are more valid than definitions that rely primarily on family characteristics. PMID:3987417

Blechman, E A; McEnroe, M J

1985-04-01

455

Effective Family Problem Solving.  

ERIC Educational Resources Information Center

Effective family problem solving was studied in 97 families of elementary-school-aged children with definite- and indefinite-solution tasks. Incentive and task independence were manipulated. It was found that definitions of effective problem solving based on directly observed measures of group interaction were more valid than definitions based on…

Blechman, Elaine A.; McEnroe, Michael J.

1985-01-01

456

Oury Family Papers  

NSDL National Science Digital Library

The Oury Family was an Arizona pioneer family, prominent in territorial political and military affairs. Their number included William S. Oury, who served as the first mayor of Tucson in 1864. He later purchased the "Arizonian" newspaper in Tubac and moved it to Tucson. Other family members contributed to the spirit and culture of the Arizona territory during the late 19th century as well. This site provides interested parties with access to their family papers, which are part of the University of Arizona Libraries Special Collections. First-time visitors should check out the Finding Aid area, as it will help them get acclimated to the breadth of the materials. The documents include family correspondence, diaries, photographs, deeds, articles, and speeches related to the Ourys' involvement in Arizona territorial military experience. It's quite a collection and one that anyone with an interest in American history will find most edifying.

457

Glutamine versus Ammonia Utilization in the NAD Synthetase Family  

PubMed Central

NAD is a ubiquitous and essential metabolic redox cofactor which also functions as a substrate in certain regulatory pathways. The last step of NAD synthesis is the ATP-dependent amidation of deamido-NAD by NAD synthetase (NADS). Members of the NADS family are present in nearly all species across the three kingdoms of Life. In eukaryotic NADS, the core synthetase domain is fused with a nitrilase-like glutaminase domain supplying ammonia for the reaction. This two-domain NADS arrangement enabling the utilization of glutamine as nitrogen donor is also present in various bacterial lineages. However, many other bacterial members of NADS family do not contain a glutaminase domain, and they can utilize only ammonia (but not glutamine) in vitro. A single-domain NADS is also characteristic for nearly all Archaea, and its dependence on ammonia was demonstrated here for the representative enzyme from Methanocaldococcus jannaschi. However, a question about the actual in vivo nitrogen donor for single-domain members of the NADS family remained open: Is it glutamine hydrolyzed by a committed (but yet unknown) glutaminase subunit, as in most ATP-dependent amidotransferases, or free ammonia as in glutamine synthetase? Here we addressed this dilemma by combining evolutionary analysis of the NADS family with experimental characterization of two representative bacterial systems: a two-subunit NADS from Thermus thermophilus and a single-domain NADS from Salmonella typhimurium providing evidence that ammonia (and not glutamine) is the physiological substrate of a typical single-domain NADS. The latter represents the most likely ancestral form of NADS. The ability to utilize glutamine appears to have evolved via recruitment of a glutaminase subunit followed by domain fusion in an early branch of Bacteria. Further evolution of the NADS family included lineage-specific loss of one of the two alternative forms and horizontal gene transfer events. Lastly, we identified NADS structural elements associated with glutamine-utilizing capabilities.

Shatalin, Konstantin; Gelfand, Mikhail S.; Osterman, Andrei L.; Sorci, Leonardo

2012-01-01

458

Prevention of Infective (Bacterial) Endocarditis: Wallet Card  

MedlinePLUS

... risk for developing adverse outcomes from infective endocarditis (IE), also known as bacterial endocarditis (BE). The guidelines for prevention of IE shown in this card are substantially different from ...

459

Bacterial Degradation of DNT and TNT Mixtures.  

National Technical Information Service (NTIS)

The major objective of this research project was to develop bacterial strains with the ability to efficiently degrade mixtures of dinitrotoluene (DNT) isomers and expand that degradation capability to include TNT. Since most contaminated sites contain mix...

R. E. Parales J. C. Spain G. R. Johnson

2005-01-01

4