Age and growth of the common blacktip shark Carcharhinus Age and growth estimates from length-at-age data were produced for the common blacktip shark Carcharhinus limbatus from Indonesia. A multi-model approach incorporating Akaike's information First record of the blacktip reef shark Carcharhinus melanopterus Carcharhiniformes: Carcharhinidae from the Tropical Eastern Pacific. Directory of Open Access Journals Sweden. Full Text Available The blacktip reef shark Carcharhinus melanopterus, is one of the most common Indo-Pacific reef sharks.
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PubMed Central. Grin, Iwan; Hartmann, Marcus D. Trimeric autotransporter adhesins TAAs are important virulence factors of many Gram-negative bacterial pathogens. TAAs form fibrous, adhesive structures on the bacterial cell surface. We have recently described the full fiber structure of SadA, a TAA of unknown function in Salmonella and other enterobacteria.
In this work, we describe the structure and function of SadB, a small inner membrane lipoprotein. The sadB gene is located in an operon with sadA; orthologous operons are only found in enterobacteria , whereas other TAAs are not typically associated with lipoproteins.
Strikingly, SadB is also a trimer, and its co-expression with SadA has a direct influence on SadA structural integrity. This is the first report of a specific export factor of a TAA, suggesting that at least in some cases TAA autotransport is assisted by additional periplasmic proteins. Enterobacteria secrete an inhibitor of Pseudomonas virulence during clinical bacteriuria. Ohlemacher, Shannon I. Escherichia coli and other Enterobacteriaceae are among the most common pathogens of the human urinary tract.
Among the genetic gains of function associated with urinary E. Using a metabolomics approach, we found that E. We detected escherichelin during clinical E. Escherichelin production by colonizing enterobacteria may help human hosts resist opportunistic infections by Pseudomonas and other pyochelin-expressing bacteria.
This siderophore-based mechanism of microbial antagonism may be one of many elements contributing to the protective effects of the human microbiome. Future UTI-preventive probiotic strains may benefit by retaining the escherichelin biosynthetic capacity of the Yersinia HPI while eliminating the Ybt biosynthetic capacity. In the last half-century, isolation and identification methods of enterobacteria groups have markedly improved by technological advancement.
Clinical microbiology tests have changed overtime from tube methods to commercial identification kits and automated identification. Tube methods are the original method for the identification of enterobacteria groups, that is, a basically essential method to recognize bacterial fermentation and biochemical principles. In this paper, traditional tube tests are discussed, such as the utilization of carbohydrates, indole, methyl red, and citrate and urease tests.
Commercial identification kits and automated instruments by computer based analysis as current methods are also discussed, and those methods provide rapidity and accuracy. Nonculture techniques of nucleic acid typing methods using PCR analysis, and immunochemical methods using monoclonal antibodies can be further developed. Alterations of both ecology and functions of gut microbiota are conspicuous traits of several inflammatory pathologies, notably metabolic diseases such as obesity and type 2 diabetes.
Moreover, the proliferation of enterobacteria , subdominant members of the intestinal microbial ecosystem, has been shown to be favored by Western diet, the strongest inducer of both metabolic diseases and gut microbiota dysbiosis. The inner interdependence between the host and the gut microbiota is based on a plethora of molecular mechanisms by which host and intestinal microbes modify each other. Among these mechanisms are as follows: i the well-known metabolic impact of short chain fatty acids, produced by microbial fermentation of complex carbohydrates from plants; ii a mutual modulation of miRNAs expression, both on the eukaryotic host and prokaryotic gut microbes side; iii the production by enterobacteria of virulence factors such as the genotoxin colibactin, shown to alter the integrity of host genome and induce a senescence-like phenotype in vitro; iv the microbial excretion of outer-membrane vesicles, which, in addition to other functions, may act as a carrier for multiple molecules such as toxins to be delivered to target cells.
In this review, I describe the major molecular mechanisms by which gut microbes exert their metabolic impact at a multi-organ level the gut barrier being in the front line and support the emerging triad of metabolic diseases, gut microbiota dysbiosis and enterobacteria infections.
All rights reserved. While ingestion of synbiotic yogurts containing Bifidobacterium animalis subsp. To further investigate this, a large-scale, crossover-design, placebo-controlled study was utilized to evaluate the effect of a synbiotic yogurt containing B.
Fecal samples were collected at 14 time points from 46 volunteers who completed the study, and changes in the intestinal bacterial levels were monitored using real-time PCR.
Strain Bb could not be detected in feces after 2 weeks of washout. A significant increase P enterobacteria. No significant differences in numbers of bifidobacteria, clostridia, or enterobacteria were observed between the probiotic and placebo groups during any of the feeding periods. However, subgrouping subjects based on lower initial bifidobacterial numbers or higher initial clostridial numbers did show corresponding significant differences between the synbiotic yogurt and placebo groups.
This was not observed for a subgroup with higher initial enterobacterial numbers. While this synbiotic yogurt can increase bifidobacterial numbers and decrease clostridial numbers but not enterobacterial numbers in some individuals, it cannot modulate these microbial groups in the majority of individuals.
Plants used in Guatemala for the treatment of gastrointestinal disorders. Confirmation of activity against enterobacteria of 16 plants. Ethnobotanical surveys and literature review identified plants used in Guatemala for the treatment of gastrointestinal disorders.
The screening of 84 showed that 34 inhibit one or more enterobacteria ; 16 of these were selected for further investigation. Extracts were obtained with three solvents of different polarity n-hexane, acetone and alcohol and the in vitro activity was demonstrated against enteropathogenic Escherichia coli, Salmonella enteritidis and Shigella flexneri.
The activity of nine ethanolic extracts against enterobacteria , particularly Acalypha guatemalensis, Diphysa robinioides, Lippia dulcis, Psidium guajava and Spondias purpurea was confirmed. The plants with antibacterial activity are discussed. Enterobacteria identification and detection of diarrheagenic Escherichia coli in a Port Complex.
To evaluate the microbiological quality of its waters, physicochemical parameters pH and salinity , the number of coliforms thermotolerants and totals , and the presence of enterobacterias and diarrheagenic Escherichia coli strains were analyzed. In order to identify the presence of E. The presence of totals and thermotolerants coliforms were positive.
Analyzing the salinity parameter, a significant increase in total coliforms was observed during the rainy season. We identified the species Escherichia coli, Proteus mirabilis, Citrobacter freundii, Proteus vulgaris, Klebsiella pneumoniae, Klebsiella ozaenae, Morganella morganii, Enterobacter cloacae and Edwardsiella tarda.
Out of the 51 E. This study reveals that the PCM is contaminated by enterobacteria and diarrheagenic E. Characterisation of a novel enterobacteria phage, CAjan, isolated from rat faeces. In this study, we describe the isolation and characterisation of the novel enterobacteria phage CAjan. This phage belongs to the order Caudovirales and the family Siphoviridae. Putative functions were assigned to 39 of the ORFs CAjan, together with Escherichia phage Seurat and Escherichia phage slur01, represent a novel and genetically distinct clade of Siphoviridae phages that could be considered to constitute a new phage genus.
Despite limited sequence similarity, the phages in this group share a number of other common features, including genome structure and the presence of queuosine biosynthesis genes. Characterization of the RcsC sensor kinase from Erwinia amylovora and other Enterobacteria.
RcsC is a hybrid sensor kinase which contains a sensor domain, a histidine kinase domain, and a receiver domain. We have previously demonstrated that, although the Erwinia amylovora rcsC mutant produces more amylovoran than the wild-type WT strain in vitro, the mutant remains nonpathogenic on both immature pear fruit and apple plants.
In this study, we have comparatively characterized the Erwinia RcsC and its homologs from various enterobacteria. Results demonstrate that expression of the Erwinia rcsC gene suppresses amylovoran production in various amylovoran overproducing WT and mutant strains, thus suggesting the presence of a net phosphatase activity of Erwinia RcsC. Findings have also demonstrated that rcsC homologs from other enterobacteria could not rescue amylovoran production of the Erwinia rcsC mutant in vitro.
However, virulence of the Erwinia rcsC mutant is partially restored by rcsC homologs from Pantoea stewartii, Yersinia pestis, and Salmonella enterica but not from Escherichia coli on apple shoots. Domain-swapping experiments have indicated that replacement of the E. Interestingly, only chimeric constructs containing the histidine kinase and receiver domains of Erwinia RcsC are fully capable of rescuing amylovoran production. These results suggest that the sensor domain of RcsC may be important in regulating bacterial virulence, whereas the activity of the histidine kinase and receiver domains of Erwinia RcsC may be essential for amylovoran production in vitro.
Strains of enterobacteria nine Escherichia coli and two Salmonella isolated from primary or secondary infections in the dog, cat, pig, calf and kangaroo were studied for the presence of extrachromosomal drug resistance factors R factors. Seven strains of E. The levels of resistance observed were comparable for all donor strains and their converted recipients.
Strains of E. The bacteria isolated from cats were recovered at the necropsy of animals that had died of purulent pleuresy and feline panleukopenia. The other strains two Salmonella and one E.
Nosocomial infections by Klebsiella pneumoniae carbapenemase producing enterobacteria in a teaching hospital. Objective To analyze the profile of patients with microorganisms resistant to carbapenems, and the prevalence of the enzyme Klebsiella pneumoniae carbapenemase in interobacteriaceae. Methods Retrospective descriptive study. From the isolation in bacteriological tests ordered by clinicians, we described the clinical and epidemiological characteristics of patients with enterobacteria resistants to carbapenems at a university hospital, between March and October Isolation in tracheal aspirates 12; The resistance to ertapenem, meropenem, and imipenem was Aminoglycosides was the class of antimicrobials that showed the highest sensitivity, Conclusion The K.
The limited therapeutic options emphasize the need for rapid laboratory detection, as well as the implementation of measures to prevent and control the spread of these pathogens. Copper homeostasis in bacteria is challenged by periodic elevation of copper levels in the environment, arising from both natural sources and human inputs.
Several mechanisms have evolved to efflux copper from bacterial cells, including the cus copper sensing copper efflux system , and pco plasmid-borne copper resistance system systems. Increasing use of copper in agricultural and industrial applications raises questions about the role of human activity in the evolution of novel copper resistance mechanisms.
Here we present evidence that CHASRI emerged and diversified in response to copper deposition across aerobic and anaerobic environments. An analysis of diversification rates and a molecular clock model suggest that CHASRI experienced repeated episodes of elevated diversification that could correspond to peaks in human copper production. Phylogenetic analyses suggest that CHASRI originated in a relative of Enterobacter cloacae as the ultimate product of sequential assembly of several pre-existing two-gene modules.
Once assembled, CHASRI dispersed via horizontal gene transfer within Enterobacteriaceae and also to certain members of Shewanellaceae, where the original pco module was replaced by a divergent pco homolog.
Analyses of copper stress mitigation suggest that CHASRI confers increased resistance aerobically, anaerobically, and during shifts between aerobic and anaerobic environments, which could explain its persistence in facultative anaerobes and emergent enteric pathogens. The increasing bacterial resistance to antibiotics has become a major public health concern bringing the threat of therapeutic impasses.
In this context, control of the spread of highly-resistant bacteria emerging antibiotics BHRe , such as glycopeptide-resistant enterococci VRE and Enterobacteriaceae producing carbapenemases CPE , is based on a dual strategy of reducing the prescription of antibiotics to limit the pressure selection and preventing the spread from carriers.
Prevention strategy is based on three different levels such as standard precautions for all patients with a particular focus on the management of excreta, and additional precautions for BHRe carriers. What makes it difficult is that carriage is usually completely asymptomatic, enterobacteria and enterococci are normal commensal of gut microbiota.
Explosive dissemination of Enterobacteriaceae producing extended spectrum beta-lactamases in hospital and community heralds the emergence of CPE whose import by patients with a history of hospitalization in abroad may be the main source of spread in France. Published by Elsevier SAS.
Dr. David Jeremiah
PubMed Central. Grin, Iwan; Hartmann, Marcus D. Trimeric autotransporter adhesins TAAs are important virulence factors of many Gram-negative bacterial pathogens. TAAs form fibrous, adhesive structures on the bacterial cell surface.
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