Escherichia coli
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ABSTRACT:
PROVIDER: PRJNA1003463 | ENA |
REPOSITORIES: ENA
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Project description:Antimicrobial Resistance in Wild Escherichia coli Isolates from Whitetail Deer
| PRJNA1005327 | ENA
Project description:The model prokaryote Escherichia coli can exist as a either a commensal or a pathogen in the gut of diverse mammalian hosts. These associations, coupled with its ease of cultivation and genetic variability, have made E. coli a popular indicator organism for tracking the origin of fecal water contamination. Source tracking accuracy is predicated on the assumption that E. coli isolates recovered from contaminated water present a genetic signature characteristic of the host from which they originated. In this study, we compared the accuracy with which E. coli isolated from humans, bear, cattle and deer could be identified by standard fingerprinting methods used for library-based microbial source tracking (repetitive element PCR and pulsed-field gel electrophoresis) in relation to microarray-based analysis of genome content. Our results show that patterns of gene presence or absence were more useful for distinguishing E. coli isolates from different sources than traditional fingerprinting methods, particularly in the case of human strains. Host-associated differences in genome composition included the presence or absence of mobile IS1 elements as well as genes encoding the ferric dicitrate iron transporter (fec), E. coli common pilus (ECP), type 1 fimbriae and the CRISPR associated cas proteins. Many of these differences occurred in regions of the E. coli chromosome previously shown to be M-bM-^@M-^\hot spotsM-bM-^@M-^] for the integration of horizontally-acquired DNA. PCR primers designed to amplify the IS1 and fec loci confirmed array results and demonstrated the ease with which gene presence/absence data can be converted into a diagnostic assay. The data presented here suggest that, despite the high level of genetic diversity observed among isolates by PFGE, human-derived strains may constitute a distinct ecotype distinguished by multiple potential library-independent source tracking markers. Twelve isolates of E. coli ( 3 from bear, 3 from cattle, 3 from deer and 3 from humans) were isolated from feces and/or raw sewage. Genome content for each strain was assessed in duplicate using comparative genome hybridization with E. coli K12 MG1655 as the reference for a total of 24 arrays.
2013-03-01 | E-GEOD-21115 | biostudies-arrayexpress
Project description:PhoP is considered a regulator of virulence despite being conserved in both pathogenic and non-pathogenic Enterobacteriaceae. While Escherichia coli strains represent both non-pathogenic commensal isolates and numerous virulent pathotypes, the PhoP virulence regulator has only been studied in commensal E. coli. To better understand how conserved transcription factors contribute to virulence, we characterized PhoP in pathogenic E. coli. Loss of phoP significantly attenuated E. coli during extraintestinal infection. This was not surprising since we demonstrated that PhoP differentially regulated the transcription of >600 genes. In addition to survival at acidic pH and resistance to polymyxin B, PhoP was required for repression of motility and oxygen-independent changes in the expression of primary dehydrogenase and terminal reductase respiratory chain components. All phenotypes have in common a reliance on an energized membrane. Thus, we hypothesized that PhoP mediated these effects by regulating genes that generate a proton motive force. Indeed, bacteria lacking PhoP exhibited a hyper-polarized membrane, and dissipation of the transmembrane electrochemical gradient increased the susceptibility of the phoP mutant to acidic pH, while inhibiting respiratory generation of the proton gradient restored resistance to antimicrobial peptides independent of lipopolysaccharide modification. These findings demonstrate a connection between PhoP, virulence, and the energized state of the membrane.
2011-07-29 | GSE31029 | GEO
Project description:PhoP is considered a regulator of virulence despite being conserved in both pathogenic and non-pathogenic Enterobacteriaceae. While Escherichia coli strains represent both non-pathogenic commensal isolates and numerous virulent pathotypes, the PhoP virulence regulator has only been studied in commensal E. coli. To better understand how conserved transcription factors contribute to virulence, we characterized PhoP in pathogenic E. coli. Loss of phoP significantly attenuated E. coli during extraintestinal infection. This was not surprising since we demonstrated that PhoP differentially regulated the transcription of >600 genes. In addition to survival at acidic pH and resistance to polymyxin B, PhoP was required for repression of motility and oxygen-independent changes in the expression of primary dehydrogenase and terminal reductase respiratory chain components. All phenotypes have in common a reliance on an energized membrane. Thus, we hypothesized that PhoP mediated these effects by regulating genes that generate a proton motive force. Indeed, bacteria lacking PhoP exhibited a hyper-polarized membrane, and dissipation of the transmembrane electrochemical gradient increased the susceptibility of the phoP mutant to acidic pH, while inhibiting respiratory generation of the proton gradient restored resistance to antimicrobial peptides independent of lipopolysaccharide modification. These findings demonstrate a connection between PhoP, virulence, and the energized state of the membrane. Comparison of gene expression between wild-type CFT073 and a CFT073 phoP deletion mutant during logarithmic phase growth in LB medium. Three biological replicates were compared from each strain.
2011-07-28 | E-GEOD-31029 | biostudies-arrayexpress
Project description:The purpose of this study is to determine whether the presence of pathogenic Escherichia coli in colon is associated with psychiatric disorders.
| 2230352 | ecrin-mdr-crc
Project description:The model prokaryote Escherichia coli can exist as a either a commensal or a pathogen in the gut of diverse mammalian hosts. These associations, coupled with its ease of cultivation and genetic variability, have made E. coli a popular indicator organism for tracking the origin of fecal water contamination. Source tracking accuracy is predicated on the assumption that E. coli isolates recovered from contaminated water present a genetic signature characteristic of the host from which they originated. In this study, we compared the accuracy with which E. coli isolated from humans, bear, cattle and deer could be identified by standard fingerprinting methods used for library-based microbial source tracking (repetitive element PCR and pulsed-field gel electrophoresis) in relation to microarray-based analysis of genome content. Our results show that patterns of gene presence or absence were more useful for distinguishing E. coli isolates from different sources than traditional fingerprinting methods, particularly in the case of human strains. Host-associated differences in genome composition included the presence or absence of mobile IS1 elements as well as genes encoding the ferric dicitrate iron transporter (fec), E. coli common pilus (ECP), type 1 fimbriae and the CRISPR associated cas proteins. Many of these differences occurred in regions of the E. coli chromosome previously shown to be “hot spots” for the integration of horizontally-acquired DNA. PCR primers designed to amplify the IS1 and fec loci confirmed array results and demonstrated the ease with which gene presence/absence data can be converted into a diagnostic assay. The data presented here suggest that, despite the high level of genetic diversity observed among isolates by PFGE, human-derived strains may constitute a distinct ecotype distinguished by multiple potential library-independent source tracking markers.
2013-03-01 | GSE21115 | GEO
Project description:Avian pathogenic Escherichia coli strains frequently cause extra-intestinal infections and are responsible for significant economic losses in the poultry industry worldwide. APEC isolates are closely related to human extraintestinal pathogenic E.coli strains and may also act as pathogens for humans. In this work, three type VI secretion systems were deleted to analyze which pathogenicity characteristics would change in the mutants, compared to wild type strain (SEPT 362).
2010-09-10 | GSE21893 | GEO
Project description:Background: This study aimed to explore potential tobramycin-resistant mutagenesis of Escherichia coli (E. coli) strains after spaceflight. Methods: A spaceflight-induced mutagenesis of multi-drug resistant E.coli strain (T1_13) on the outer space for 64 days (ST5), and a ground laboratory with the same conditions (GT5) were conducted. Both whole-genome sequencing and RNA-sequencing were performed. Results: A total of 75 SNPs and 20 InDels were found to be associated with the resistance mechanism. Compared to T1_13, 1242 genes were differentially expressed in more than 20 of 38 tobramycin-resistant E. coli isolates while not in GT5. Function annotation of these SNPs/InDels related genes and differentially expressed genes was performed. Conclusion: This study provided clues for potential tobramycin-resistant spaceflight-induced mutagenesis of E. coli.
2019-12-13 | GSE123795 | GEO
Project description:Despite the characterization of many aetiologic genetic changes. The specific causative factors in the development of sporadic colorectal cancer remain unclear. This study was performed to detect the possible role of Enteropathogenic Escherichia coli (EPEC) in developing colorectal carcinoma.
| 2184564 | ecrin-mdr-crc
Project description:Pathogenic biofilms have been associated with persistent infections due to their high resistance to antimicrobial agents. To identify non-toxic biofilm inhibitors for enterohemorrhagic Escherichia coli O157:H7, indole-3-acetaldehyde was used and reduced E. coli O157:H7 biofilm formation. Global transcriptome analyses revealed that indole-3-acetaldehyde most repressed two curli operons, csgBAC and csgDEFG, and induced tryptophanase (tnaAB) in E. coli O157:H7 biofilm cells. Electron microscopy showed that indole-3-acetaldehyde reduced curli production in E. coli O157:H7. Together, this study shows that Actinomycetales are an important resource of biofilm inhibitors as well as antibiotics.
2012-07-05 | GSE30424 | GEO