scholarly journals IS1R-Mediated Plasticity of IncL/M Plasmids Leads to the Insertion ofblaOXA-48into the Escherichia coli Chromosome

2014 ◽  
Vol 58 (7) ◽  
pp. 3785-3790 ◽  
Author(s):  
R. Beyrouthy ◽  
F. Robin ◽  
J. Delmas ◽  
L. Gibold ◽  
G. Dalmasso ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Insertion Sequences ◽  
Content Type ◽  
Genetic Environment ◽  
E Coli ◽  
The Family ◽  
Insertion Sites ◽  
Low Levels ◽  
Encoding Gene ◽  
Encoding Genes

ABSTRACTThe OXA-48 carbapenemase is mainly encoded by ∼62-kb IncL/M plasmids. However, chromosome-mediated genes have been observed inEscherichia coliisolates. In this work, we investigated the genetic environment of OXA-48 in members of the familyEnterobacteriaceae(n= 22) to understand how the OXA-48-encoding gene is transferred into theE. colichromosome. The OXA-48-encoding gene was located within intact Tn1999.2transposons in the ∼62-kb plasmids or within a truncated variant of Tn1999.2for the OXA-48-encoding genes located in the chromosomes ofE. colibacteria. The analysis of the Tn1999.2genetic environment revealed an inverted orientation of the transposon in five ∼62-kb plasmids (5/14 [35%]) and in all chromosome inserts (n= 8). The sequencing of pRA35 plasmid showed that this orientation of Tn1999.2and the acquisition of an IS1Rinsertion sequence generated a 21.9-kb IS1R-based composite transposon encoding OXA-48 and designated Tn6237. The sequencing of a chromosomal insert encoding OXA-48 also revealed this new transposon in theE. colichromosome. PCR mapping showed the presence of this element in all strains harboring an OXA-48-encoding chromosomal insert. However, different insertion sites of this transposon were observed in theE. colichromosome. Overall, these findings indicate a plasticity of the OXA-48 genetic environment mediated by IS1Rinsertion sequences. The insertion sequences can induce the transfer of the OXA-encoding gene intoE. colichromosomes and thereby promote its persistence and expression at low levels.

scholarly journals Molecular Characterization of Human Atypical Sorbitol-Fermenting Enteropathogenic Escherichia coli O157 Reveals High Diversity

2016 ◽  
Vol 54 (5) ◽  
pp. 1357-1363 ◽  
Author(s):  
Annelene Kossow ◽  
Wenlan Zhang ◽  
Martina Bielaszewska ◽  
Sophie Rhode ◽  
Kevin Hansen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clinical Symptoms ◽  
Diverse Group ◽  
Full Spectrum ◽  
Content Type ◽  
E Coli ◽  
Uremic Syndrome ◽  
Encoding Gene ◽  
Encoding Genes

Alongside the well-characterized enterohemorrhagicEscherichia coli(EHEC) O157:H7, serogroup O157 comprises sorbitol-fermenting typical and atypical enteropathogenicE. coli(EPEC/aEPEC) strains that carry the intimin-encoding geneeaebut not Shiga toxin-encoding genes (stx). Since little is known about these pathogens, we characterized 30 clinical isolates from patients with hemolytic uremic syndrome (HUS) or uncomplicated diarrhea with respect to their flagellin gene (fliC) type and multilocus sequence type (MLST). Moreover, we applied whole-genome sequencing (WGS) to determine the phylogenetic relationship with othereae-positive EHEC serotypes and the composition of therfbO157 region.fliCtyping resulted in fivefliCtypes (H7, H16, H34, H39, and H45). Isolates of eachfliCtype shared a unique ST. In comparison to the 42 HUS-associatedE. coli(HUSEC) strains, only thestx-negative isolates withfliCH7 shared their ST with EHEC O157:H7/H−strains. With the exception of one O157:H−fliCH16isolate, HUS was exclusively associated withfliCH7. WGS corroborated the separation of thefliCH7 isolates, which were closely related to the EHEC O157:H7/H−isolates, and the diverse group of isolates exhibiting differentfliCtypes, indicating independent evolution of the different serotypes. This was also supported by the heterogeneity within therfbO157 region that exhibited extensive recombinations. The genotypic subtypes and distribution of clinical symptoms suggested that thestx-negative O157 strains withfliCH7 were originally EHEC strains that loststx. The remaining isolates form a distinct and diverse group of atypical EPEC isolates that do not possess the full spectrum of virulence genes, underlining the importance of identifying the H antigen for clinical risk assessment.

scholarly journals Autotransporter Protein-Encoding Genes of Diarrheagenic Escherichia coli Are Found in both Typical and Atypical Enteropathogenic E. coli Strains

2012 ◽  
Vol 79 (1) ◽  
pp. 411-414 ◽  
Author(s):  
Afonso G. Abreu ◽  
Vanessa Bueris ◽  
Tatiane M. Porangaba ◽  
Marcelo P. Sircili ◽  
Fernando Navarro-Garcia ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Content Type ◽  
E Coli ◽  
Diarrheagenic Escherichia Coli ◽  
Virulence Markers ◽  
Protein Encoding ◽  
Encoding Genes ◽  
Specific Virulence

ABSTRACTAutotransporter (AT) protein-encoding genes of diarrheagenicEscherichia coli(DEC) pathotypes (cah,eatA,ehaABCDJ,espC,espI,espP,pet,pic,sat, andtibA) were detected in typical and atypical enteropathogenicE. coli(EPEC) in frequencies between 0.8% and 39.3%. Although these ATs have been described in particular DEC pathotypes, their presence in EPEC indicates that they should not be considered specific virulence markers.

scholarly journals Escherichia coli Isolates That Carryvat,fyuA,chuA, andyfcVEfficiently Colonize the Urinary Tract

2012 ◽  
Vol 80 (12) ◽  
pp. 4115-4122 ◽  
Author(s):  
Rachel R. Spurbeck ◽  
Paul C. Dinh ◽  
Seth T. Walk ◽  
Ann E. Stapleton ◽  
Thomas M. Hooton ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Virulence Factors ◽  
Neonatal Meningitis ◽  
Content Type ◽  
E Coli ◽  
Core Set ◽  
Encoding Genes

ABSTRACTExtraintestinalEscherichia coli(ExPEC), a heterogeneous group of pathogens, encompasses avian, neonatal meningitis, and uropathogenicE. colistrains. While several virulence factors are associated with ExPEC, there is no core set of virulence factors that can be used to definitively differentiate these pathotypes. Here we describe a multiplex of four virulence factor-encoding genes,yfcV,vat,fyuA, andchuA, highly associated with uropathogenicE. colistrains that can distinguish three groups ofE. coli: diarrheagenic and animal-associatedE. colistrains, human commensal and avian pathogenicE. colistrains, and uropathogenic and neonatal meningitisE. colistrains. Furthermore, human intestinal isolates that encode all four predictor genes express them during exponential growth in human urine and colonize the bladder in the mouse model of ascending urinary tract infection in higher numbers than human commensal strains that do not encode the four predictor genes (P= 0.02), suggesting that the presence of the predictors correlates with uropathogenic potential.

scholarly journals Complete Genome Sequence of Escherichia coli Podophage Penshu1

2019 ◽  
Vol 8 (38) ◽  
Author(s):  
Douglas Pechacek ◽  
Myung Hwangbo ◽  
Russell Moreland ◽  
Mei Liu ◽  
Jolene Ramsey
Keyword(s):  
Escherichia Coli ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Coliform Bacteria ◽  
Negative Bacterium ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Protein Encoding ◽  
Encoding Genes

Escherichia coli 4s is a Gram-negative bacterium found in the equine intestinal ecosystem alongside diverse other coliform bacteria and bacteriophages. This announcement describes the complete genome of the T7-like E. coli 4s podophage Penshu1. From its 39,263-bp genome, 54 protein-encoding genes and a 179-bp terminal repeat were predicted.

scholarly journals Systematic Nomenclature for GGDEF and EAL Domain-Containing Cyclic Di-GMP Turnover Proteins of Escherichia coli: TABLE 1

2015 ◽  
Vol 198 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Regine Hengge ◽  
Michael Y. Galperin ◽  
Jean-Marc Ghigo ◽  
Mark Gomelsky ◽  
Jeffrey Green ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Mechanisms ◽  
Bacterial Species ◽  
Content Type ◽  
E Coli ◽  
Diguanylate Cyclases ◽  
Genes Encoding ◽  
Systematic Nomenclature ◽  
K 12 ◽  
Encoding Genes

In recent years,Escherichia colihas served as one of a few model bacterial species for studying cyclic di-GMP (c-di-GMP) signaling. The widely usedE. coliK-12 laboratory strains possess 29 genes encoding proteins with GGDEF and/or EAL domains, which include 12 diguanylate cyclases (DGC), 13 c-di-GMP-specific phosphodiesterases (PDE), and 4 “degenerate” enzymatically inactive proteins. In addition, six new GGDEF and EAL (GGDEF/EAL) domain-encoding genes, which encode two DGCs and four PDEs, have recently been found in genomic analyses of commensal and pathogenicE. colistrains. As a group of researchers who have been studying the molecular mechanisms and the genomic basis of c-di-GMP signaling inE. coli, we now propose a general and systematicdgcandpdenomenclature for the enzymatically active GGDEF/EAL domain-encoding genes of this model species. This nomenclature is intuitive and easy to memorize, and it can also be applied to additional genes and proteins that might be discovered in various strains ofE. coliin future studies.

scholarly journals Molecular Characterization of UpaB and UpaC, Two New Autotransporter Proteins of Uropathogenic Escherichia coli CFT073

2011 ◽  
Vol 80 (1) ◽  
pp. 321-332 ◽  
Author(s):  
Luke P. Allsopp ◽  
Christophe Beloin ◽  
Glen C. Ulett ◽  
Jaione Valle ◽  
Makrina Totsika ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Characterization ◽  
Host Responses ◽  
Upec Strain ◽  
Content Type ◽  
Pcr Screening ◽  
E Coli ◽  
K 12 ◽  
Encoding Genes

ABSTRACTUropathogenicEscherichia coli(UPEC) is the primary cause of urinary tract infection (UTI) in the developed world. The major factors associated with virulence of UPEC are fimbrial adhesins, which mediate specific attachment to host receptors and trigger innate host responses. Another group of adhesins is represented by the autotransporter (AT) subgroup of proteins. The genome-sequenced prototype UPEC strain CFT073 contains 11 putative AT-encoding genes. In this study, we have performed a detailed molecular characterization of two closely related AT adhesins from CFT073: UpaB (c0426) and UpaC (c0478). PCR screening revealed that theupaBandupaCAT-encoding genes are common inE. coli. TheupaBandupaCgenes were cloned and characterized in a recombinantE. coliK-12 strain background. This revealed that they encode proteins located at the cell surface but possess different functional properties: UpaB mediates adherence to several ECM proteins, while UpaC expression is associated with increased biofilm formation. In CFT073,upaBis expressed whileupaCis transcriptionally repressed by the global regulator H-NS. In competitive colonization experiments employing the mouse UTI model, CFT073 significantly outcompeted itsupaB(but notupaC) isogenic mutant strain in the bladder. This attenuated phenotype was also observed in single-challenge experiments, where deletion of theupaBgene in CFT073 significantly reduced early colonization of the bladder.

scholarly journals Characterization of Escherichia coli obtained from patients undergoing peritoneal dialysis and diagnosed with peritonitis in a Brazilian centre

2019 ◽  
Vol 68 (9) ◽  
pp. 1330-1340 ◽  
Author(s):  
Regiane C. B. Dias ◽  
Melissa A. Vieira ◽  
Ana C. Moro ◽  
Danilo F. M. Ribolli ◽  
Aydir C. M. Monteiro ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Peritoneal Dialysis ◽  
Antimicrobial Resistance ◽  
Virulence Factor ◽  
Type Species ◽  
Content Type ◽  
E Coli ◽  
Link Type ◽  
Biofilm Production ◽  
Encoding Genes

Purpose. This study aimed to characterize 27 Escherichia coli isolates obtained from peritoneal dialysis (PD)-related peritonitis that occurred at the University Hospital of Botucatu Medical School, Brazil, between 1997 and 2015. Methodology. These isolates were characterized regarding the occurrence of 22 virulence factor-encoding genes, antimicrobial resistance and biofilm production. We then evaluated whether these factors influenced the clinical outcome. Results. Over an 18-year period, 726 episodes of PD-related peritonitis were diagnosed, with 27 of them (3.7 %) being due to E. coli . The majority of the isolates were classified in phylogroups B1 (33.3 %), B2 (30.0 %) or F (18.0 %). fimH (100.0 %), ompT (66.7 %) and irp2 (51.9 %) were the most prevalent genes, while papA, papC, iha, sat, irp2, iucD, ireA, ibe10, ompT and kpsMTII were significantly more prevalent among isolates belonging to phylogroups B2 and F (P<0.05). Non-susceptibility to quinolones was detected in six isolates, which harboured chromosomal and/or plasmid-mediated quinolone resistance determinants, while two CTX-M extended-spectrum β-lactamase-producing E. coli were identified. Virulence factor-encoding genes (alone or in combination) and antimicrobial resistance were not associated with non-resolution outcomes. However, there was a trend for the ability to produce biofilm to be associated with treatment failure, although this association was not statistically significant. Conclusion. The E. coli isolates were heterogeneous in terms of the features investigated, and were susceptible to most of the antimicrobial drugs tested, despite the unsuccessful treatment observed in more than 50.0 % of the patients. Studies including more cases could help to clarify if biofilm production can influence the outcome in patients with PD-related peritonitis.

scholarly journals Variable within- and between-Herd Diversity of CTX-M Cephalosporinase-Bearing Escherichia coli Isolates from Dairy Cattle

2012 ◽  
Vol 78 (13) ◽  
pp. 4552-4560 ◽  
Author(s):  
Dixie F. Mollenkopf ◽  
Matthew F. Weeman ◽  
Joshua B. Daniels ◽  
Melanie J. Abley ◽  
Jennifer L. Mathews ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dairy Cattle ◽  
Coliform Bacteria ◽  
Bacterial Dna ◽  
Fecal Samples ◽  
Content Type ◽  
Beta Lactamases ◽  
E Coli ◽  
Plasmid Replicon ◽  
Encoding Genes

ABSTRACTblaCTX-Mbeta-lactamases confer resistance to critically important cephalosporin drugs. Recovered from both hospital- and community-acquired infections,blaCTX-Mwas first reported in U.S. livestock in 2010. It has been hypothesized that veterinary use of cephalosporins in livestock populations may lead to the dissemination of beta-lactamase-encoding genes. Therefore, our objectives were to estimate the frequency and distribution of coliform bacteria harboringblaCTX-Min the fecal flora of Ohio dairy cattle populations. In addition, we characterized the CTX-M alleles carried by the isolates, their plasmidic contexts, and the genetic diversity of the bacterial isolates themselves. We also evaluated the association between ceftiofur use and the likelihood of recovering cephalosporinase-producing bacteria. Thirty fresh fecal samples and owner-reported ceftiofur use data were collected from each of 25 Ohio dairy farms. Fecal samples (n= 747) yielded 70blaCTX-M-positiveEscherichia coliisolates from 5/25 herds, 715blaCMY-2E. coliisolates from 25/25 herds, and 274Salmonellaspp. from 20/25 herds. The within-herd prevalence amongblaCTX-M-positive herds ranged from 3.3 to 100% of samples. Multiple pulsed-field gel electrophoresis (PFGE) patterns, plasmid replicon types, and CTX-M genes were detected. Plasmids with CTX-M-1, -15, and -14 alleles were clonal by restriction fragment length polymorphism (RFLP) within herds, and specific plasmid incompatibility group markers were consistently associated with eachblaCTX-Mallele. PFGE of total bacterial DNA showed similar within-herd clustering, with the exception of one herd, which revealed at least 6 different PFGE signatures. We were unable to detect an association between owner-reported ceftiofur use and the probability of recoveringE. colicarryingblaCTX-MorblaCMY-2.

scholarly journals Epidemiology and Risk Factors for Isolation of Escherichia coli Producing CTX-M-Type Extended-Spectrum β-Lactamase in a Large U.S. Medical Center

2013 ◽  
Vol 57 (8) ◽  
pp. 4010-4018 ◽  
Author(s):  
Kayoko Hayakawa ◽  
Sureka Gattu ◽  
Dror Marchaim ◽  
Ashish Bhargava ◽  
Mohan Palla ◽  
...  
Keyword(s):  
Risk Factors ◽  
Escherichia Coli ◽  
Medical Center ◽  
Antibiotic Use ◽  
Content Type ◽  
E Coli ◽  
H2 Blocker ◽  
Extended Spectrum ◽  
Independent Risk Factors ◽  
Encoding Genes

ABSTRACTA case-case-control study was conducted to identify independent risk factors for recovery ofEscherichia colistrains producing CTX-M-type extended-spectrum β-lactamases (CTX-ME. coli) within a large Southeastern Michigan medical center. Unique cases with isolation of ESBL-producingE. colifrom February 2010 through July 2011 were analyzed by PCR forblaCTX-M,blaTEM, andblaSHVgenes. Patients with CTX-ME. coliwere compared to patients withE. colistrains not producing CTX-M-type ESBLs (non-CTX-ME. coli) and uninfected controls. Of 575 patients with ESBL-producingE. coli, 491 (85.4%) isolates contained a CTX-M ESBL gene. A total of 319 (84.6%) patients with CTX-ME. coli(282 [74.8%] CTX-M-15 type) were compared to 58 (15.4%) non-CTX-ME. colipatients and to uninfected controls. Independent risk factors for CTX-ME. coliisolation compared to non-CTX-ME. coliincluded male gender, impaired consciousness, H2 blocker use, immunosuppression, and exposure to penicillins and/or trimethoprim-sulfamethoxazole. Compared to uninfected controls, independent risk factors for isolation of CTX-ME. coliincluded presence of a urinary catheter, previous urinary tract infection, exposure to oxyimino-cephalosporins, dependent functional status, non-home residence, and multiple comorbid conditions. Within 48 h of admission, community-acquired CTX-ME. coli(n= 51 [16%]) and non-CTX-ME coli(n= 11 [19%]) strains were isolated from patients with no recent health care contacts. CTX-ME. colistrains were more resistant to multiple antibiotics than non-CTX-ME. colistrains. CTX-M-encoding genes, especiallyblaCTX-M-15type, represented the most common ESBL determinants from ESBL-producingE. coli, the majority of which were present upon admission. Septic patients with risk factors for isolation of CTX-ME. colishould be empirically treated with appropriate agents. Regional infection control efforts and judicious antibiotic use are needed to control the spread of these organisms.

scholarly journals Effects of a Mutation in thegyrAGene on the Virulence of Uropathogenic Escherichia coli

2015 ◽  
Vol 59 (8) ◽  
pp. 4662-4668 ◽  
Author(s):  
Javier Sánchez-Céspedes ◽  
Emma Sáez-López ◽  
N. Frimodt-Møller ◽  
Jordi Vila ◽  
Sara M. Soto
Keyword(s):  
Escherichia Coli ◽  
Bacterial Infections ◽  
Dna Supercoiling ◽  
Uropathogenic Escherichia Coli ◽  
Topoisomerase Iv ◽  
Content Type ◽  
E Coli ◽  
Type Gene ◽  
Encoding Genes

ABSTRACTFluoroquinolones are among the drugs most extensively used for the treatment of bacterial infections in human and veterinary medicine. Resistance to quinolones can be chromosome or plasmid mediated. The chromosomal mechanism of resistance is associated with mutations in the DNA gyrase- and topoisomerase IV-encoding genes and mutations in regulatory genes affecting different efflux systems, among others. We studied the role of the acquisition of a mutation in thegyrAgene in the virulence and protein expression of uropathogenicEscherichia coli(UPEC). The HC14366M strain carrying a mutation in thegyrAgene (S83L) was found to lose the capacity to cause cystitis and pyelonephritis mainly due to a decrease in the expression of thefimA,papA,papB, andompAgenes. The levels of expression of thefimA,papB, andompAgenes were recovered on complementing the strain with a plasmid containing thegyrAwild-type gene. However, only a slight recovery was observed in the colonization of the bladder in the GyrA complement strain compared to the mutant strain in a murine model of ascending urinary tract infection. In conclusion, a mutation in thegyrAgene of uropathogenicE. colireduced the virulence of the bacteria, likely in association with the effect of DNA supercoiling on the expression of several virulence factors and proteins, thereby decreasing their capacity to cause cystitis and pyelonephritis.

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