scholarly journals ArcA Controls Metabolism, Chemotaxis, and Motility Contributing to the Pathogenicity of Avian Pathogenic Escherichia coli

2015 ◽  
Vol 83 (9) ◽  
pp. 3545-3554 ◽  
Author(s):  
Fengwei Jiang ◽  
Chunxia An ◽  
Yinli Bao ◽  
Xuefeng Zhao ◽  
Robert L. Jernigan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rna Seq ◽  
Global Regulator ◽  
Content Type ◽  
E Coli ◽  
Citrate Metabolism ◽  
Food Borne ◽  
Pathogenic Escherichia Coli ◽  
And Control ◽  
Potential Food

Avian pathogenicEscherichia coli(APEC) strains cause one of the three most significant infectious diseases in the poultry industry and are also potential food-borne pathogens threating human health. In this study, we showed that ArcA (aerobicrespiratorycontrol), a global regulator important forE. coli's adaptation from anaerobic to aerobic conditions and control of that bacterium's enzymatic defenses against reactive oxygen species (ROS), is involved in the virulence of APEC. Deletion ofarcAsignificantly attenuates the virulence of APEC in the duck model. Transcriptome sequencing (RNA-Seq) analyses comparing the APEC wild type and thearcAmutant indicate that ArcA regulates the expression of 129 genes, including genes involved in citrate transport and metabolism, flagellum synthesis, and chemotaxis. Further investigations revealed thatcitCEFXGcontributed to APEC's microaerobic growth at the lag and log phases when cultured in duck serum and that ArcA played a dual role in the control of citrate metabolism and transportation. In addition, deletion of flagellar genesmotAandmotBand chemotaxis genecheAsignificantly attenuated the virulence of APEC, and ArcA was shown to directly regulate the expression ofmotA,motB, andcheA. The combined results indicate that ArcA controls metabolism, chemotaxis, and motility contributing to the pathogenicity of APEC.

scholarly journals Effects of Norspermidine and Spermidine on Biofilm Formation by Potentially Pathogenic Escherichia coli and Salmonella enterica Wild-Type Strains

2015 ◽  
Vol 81 (6) ◽  
pp. 2226-2232 ◽  
Author(s):  
Live L. Nesse ◽  
Kristin Berg ◽  
Lene K. Vestby
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Biofilm Formation ◽  
Wild Type ◽  
Content Type ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Serovar Typhimurium ◽  
And Control ◽  
Type Strains

ABSTRACTPolyamines are present in all living cells. In bacteria, polyamines are involved in a variety of functions, including biofilm formation, thus indicating that polyamines may have potential in the control of unwanted biofilm. In the present study, the effects of the polyamines norspermidine and spermidine on biofilms of 10 potentially pathogenic wild-type strains ofEscherichia coliserotype O103:H2,Salmonella entericasubsp.entericaserovar Typhimurium, andS. entericaserovar Agona were investigated. We found that exogenously supplied norspermidine and spermidine did not mediate disassembly of preformed biofilm of any of theE. coliandS. entericastrains. However, the polyamines did affect biofilm production. Interestingly, the two species reacted differently to the polyamines. Both polyamines reduced the amount of biofilm formed byE. colibut tended to increase biofilm formation byS. enterica. Whether the effects observed were due to the polyamines specifically targeting biofilm formation, being toxic for the cells, or maybe a combination of the two, is not known. However, there were no indications that the effect was mediated through binding to exopolysaccharides, as earlier suggested forE. coli. Our results indicate that norspermidine and spermidine do not have potential as inhibitors ofS. entericabiofilm. Furthermore, we found that the commercial polyamines used contributed to the higher pH of the test medium. Failure to acknowledge and control this important phenomenon may lead to misinterpretation of the results.

scholarly journals Potentially Human-Pathogenic Escherichia coli O26 in Norwegian Sheep Flocks

2011 ◽  
Vol 77 (14) ◽  
pp. 4949-4958 ◽  
Author(s):  
C. Sekse ◽  
M. Sunde ◽  
B.-A. Lindstedt ◽  
P. Hopp ◽  
T. Bruheim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Human Pathogens ◽  
Content Type ◽  
Representative Sampling ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Close Relationship ◽  
Large Survey

ABSTRACTA national survey ofEscherichia coliO26 in Norwegian sheep flocks was conducted, using fecal samples to determine the prevalence. In total, 491 flocks were tested, andE. coliO26 was detected in 17.9% of the flocks. One hundred forty-twoE. coliO26 isolates were examined for flagellar antigens (H typing) and four virulence genes, includingstxandeae, to identify possible Shiga toxin-producingE. coli(STEC) and enteropathogenicE. coli(EPEC). Most isolates (129 out of 142) were identified asE. coliO26:H11. They possessedeaeand may have potential as human pathogens, although only a small fraction were identified as STEC O26:H11, giving a prevalence in sheep flocks of only 0.8%. Correspondingly, the sheep flock prevalence of atypical EPEC (aEPEC) O26:H11 was surprisingly high (15.9%). The genetic relationship between theE. coliO26:H11 isolates was investigated by pulsed-field gel electrophoresis (PFGE) and multilocus variable number tandem repeat analysis (MLVA), identifying 63 distinct PFGE profiles and 22 MLVA profiles. Although the MLVA protocol was less discriminatory than PFGE and a few cases of disagreement were observed, comparison by partition mapping showed an overall good accordance between the two methods. A close relationship between a few isolates of aEPEC O26:H11 and STEC O26:H11 was identified, but all theE. coliO26:H11 isolates should be considered potentially pathogenic to humans. The present study consisted of a representative sampling of sheep flocks from all parts of Norway. This is the first large survey of sheep flocks focusing onE. coliO26 in general, including results of STEC, aEPEC, and nonpathogenic isolates.

scholarly journals Elucidation of Regulatory Modes for Five Two-Component Systems in Escherichia coli Reveals Novel Relationships

mSystems ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Kumari Sonal Choudhary ◽  
Julia A. Kleinmanns ◽  
Katherine Decker ◽  
Anand V. Sastry ◽  
Ye Gao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Target Gene ◽  
Target Genes ◽  
Rna Seq ◽  
Content Type ◽  
E Coli ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems

ABSTRACT Escherichia coli uses two-component systems (TCSs) to respond to environmental signals. TCSs affect gene expression and are parts of E. coli’s global transcriptional regulatory network (TRN). Here, we identified the regulons of five TCSs in E. coli MG1655: BaeSR and CpxAR, which were stimulated by ethanol stress; KdpDE and PhoRB, induced by limiting potassium and phosphate, respectively; and ZraSR, stimulated by zinc. We analyzed RNA-seq data using independent component analysis (ICA). ChIP-exo data were used to validate condition-specific target gene binding sites. Based on these data, we do the following: (i) identify the target genes for each TCS; (ii) show how the target genes are transcribed in response to stimulus; and (iii) reveal novel relationships between TCSs, which indicate noncognate inducers for various response regulators, such as BaeR to iron starvation, CpxR to phosphate limitation, and PhoB and ZraR to cell envelope stress. Our understanding of the TRN in E. coli is thus notably expanded. IMPORTANCE E. coli is a common commensal microbe found in the human gut microenvironment; however, some strains cause diseases like diarrhea, urinary tract infections, and meningitis. E. coli’s two-component systems (TCSs) modulate target gene expression, especially related to virulence, pathogenesis, and antimicrobial peptides, in response to environmental stimuli. Thus, it is of utmost importance to understand the transcriptional regulation of TCSs to infer bacterial environmental adaptation and disease pathogenicity. Utilizing a combinatorial approach integrating RNA sequencing (RNA-seq), independent component analysis, chromatin immunoprecipitation coupled with exonuclease treatment (ChIP-exo), and data mining, we suggest five different modes of TCS transcriptional regulation. Our data further highlight noncognate inducers of TCSs, which emphasizes the cross-regulatory nature of TCSs in E. coli and suggests that TCSs may have a role beyond their cognate functionalities. In summary, these results can lead to an understanding of the metabolic capabilities of bacteria and correctly predict complex phenotype under diverse conditions, especially when further incorporated with genome-scale metabolic models.

scholarly journals Risk Factors for Infection or Colonization with CTX-M Extended-Spectrum-β-Lactamase-Positive Escherichia coli

2012 ◽  
Vol 56 (11) ◽  
pp. 5575-5580 ◽  
Author(s):  
Jennifer H. Han ◽  
Kei Kasahara ◽  
Paul H. Edelstein ◽  
Warren B. Bilker ◽  
Ebbing Lautenbach
Keyword(s):  
Risk Factors ◽  
Escherichia Coli ◽  
Control Strategies ◽  
Content Type ◽  
E Coli ◽  
Extended Spectrum ◽  
Increased Risk ◽  
Urinary Culture ◽  
Multivariable Analyses ◽  
And Control

ABSTRACTThere has been a significant increase in the prevalence ofEnterobacteriaceaethat produce CTX-M-type extended-spectrum β-lactamases. The objective of this study was to evaluate risk factors for infection or colonization with CTX-M-positiveEscherichia coli. A case-control study was conducted within a university system from 1 January 2007 to 31 December 2008. All patients with clinical cultures withE. colidemonstrating resistance to extended-spectrum cephalosporins were included. Case patients were designated as those with cultures positive for CTX-M-positiveE. coli, and control patients were designated as those with non-CTX-M-producingE. coli. Multivariable logistic regression analyses were performed to evaluate risk factors for CTX-M-positive isolates. A total of 83 (56.8%) of a total of 146 patients had cultures with CTX-M-positiveE. coli. On multivariable analyses, there was a significant association between infection or colonization with CTX-M-type β-lactamase-positiveE. coliand receipt of piperacillin-tazobactam in the 30 days prior to the culture date (odds ratio [OR], 7.36; 95% confidence interval [CI], 1.61 to 33.8;P= 0.01) and a urinary culture source (OR, 0.36; 95% CI, 0.17 to 0.77;P= 0.008). The rates of resistance to fluoroquinolones were significantly higher in isolates from case patients than in isolates from control patients (90.4 and 50.8%, respectively;P< 0.001). We found that nonurinary sources of clinical cultures and the recent use of piperacillin-tazobactam conferred an increased risk of colonization or infection with CTX-M-positiveE. coli. Future studies will need to focus on outcomes associated with infections due to CTX-M-positiveE. coli, as well as infection control strategies to limit the spread of these increasingly common organisms.

scholarly journals Characteristics of Emerging Human-Pathogenic Escherichia coli O26:H11 Strains Isolated in France between 2010 and 2013 and Carrying thestx2dGene Only

2014 ◽  
Vol 53 (2) ◽  
pp. 486-492 ◽  
Author(s):  
Sabine Delannoy ◽  
Patricia Mariani-Kurkdjian ◽  
Stephane Bonacorsi ◽  
Sandrine Liguori ◽  
Patrick Fach
Keyword(s):  
Escherichia Coli ◽  
Virulence Gene ◽  
Gene Profiling ◽  
Content Type ◽  
E Coli ◽  
Negative Results ◽  
Pathogenic Escherichia Coli ◽  
Short Palindromic Repeat ◽  
Uremic Syndrome ◽  
First Time

Strains ofEscherichia coliO26:H11 that were positive forstx2alone (n= 23), which were not epidemiologically related or part of an outbreak, were isolated from pediatric patients in France between 2010 and 2013. We were interested in comparing these strains with the new highly virulentstx2a-positiveE. coliO26 clone sequence type 29 (ST29) that has emerged recently in Europe, and we tested them by multilocus sequence typing (MLST),stx2subtyping, clustered regularly interspaced short palindromic repeat (CRISPR) sequencing, and plasmid (ehxA,katP,espP, andetpD) and chromosomal (Z2098,espK, andespV) virulence gene profiling. We showed that 16 of the 23 strains appeared to correspond to this new clone, but the characteristics of 12 strains differed significantly from the previously described characteristics, with negative results for both plasmid and chromosomal genetic markers. These 12 strains exhibited a ST29 genotype and related CRISPR arrays (CRISPR2a alleles 67 or 71), suggesting that they evolved in a common environment. This finding was corroborated by the presence ofstx2din 7 of the 12 ST29 strains. This is the first time thatE. coliO26:H11 carryingstx2dhas been isolated from humans. This is additional evidence of the continuing evolution of virulent Shiga toxin-producingE. coli(STEC) O26 strains. A new O26:H11 CRISPR PCR assay, SP_O26_E, has been developed for detection of these 12 particular ST29 strains ofE. coliO26:H11. This test is useful to better characterize thestx2-positive O26:H11 clinical isolates, which are associated with severe clinical outcomes such as bloody diarrhea and hemolytic uremic syndrome.

scholarly journals Draft Genomic Sequences of Nine Extraintestinal Pathogenic Escherichia coli Isolates from Retail Chicken Skin

2018 ◽  
Vol 7 (7) ◽  
Author(s):  
Aixia Xu ◽  
Shannon Tilman ◽  
Kristy Wisser-Parker ◽  
O. Joseph Scullen ◽  
Christopher H. Sommers
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Genomic Sequences ◽  
Content Type ◽  
E Coli ◽  
Safety Research ◽  
Pathogenic Escherichia Coli ◽  
Chicken Skin

Extraintestinal pathogenic Escherichia coli strains were isolated from retail chicken skin. Here, we report the draft genomic sequences for these nine E. coli isolates, which are currently being used in agricultural and food safety research.

scholarly journals Sequencing and Functional Annotation of Avian Pathogenic Escherichia coli Serogroup O78 Strains Reveal the Evolution of E. coli Lineages Pathogenic for Poultry via Distinct Mechanisms

2012 ◽  
Vol 81 (3) ◽  
pp. 838-849 ◽  
Author(s):  
Francis Dziva ◽  
Heidi Hauser ◽  
Thomas R. Connor ◽  
Pauline M. van Diemen ◽  
Graham Prescott ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Core Genome ◽  
Systemic Disease ◽  
Genomic Islands ◽  
Content Type ◽  
E Coli ◽  
Group 4 ◽  
Pathogenic Escherichia Coli ◽  
Transposon Mutants ◽  
Avian Disease

ABSTRACTAvian pathogenicEscherichia coli(APEC) causes respiratory and systemic disease in poultry. Sequencing of a multilocus sequence type 95 (ST95) serogroup O1 strain previously indicated that APEC resemblesE. colicausing extraintestinal human diseases. We sequenced the genomes of two strains of another dominant APEC lineage (ST23 serogroup O78 strains χ7122 and IMT2125) and compared them to each other and to the reannotated APEC O1 sequence. For comparison, we also sequenced a human enterotoxigenicE. coli(ETEC) strain of the same ST23 serogroup O78 lineage. Phylogenetic analysis indicated that the APEC O78 strains were more closely related to human ST23 ETEC than to APEC O1, indicating that separation of pathotypes on the basis of their extraintestinal or diarrheagenic nature is not supported by their phylogeny. The accessory genome of APEC ST23 strains exhibited limited conservation of APEC O1 genomic islands and a distinct repertoire of virulence-associated loci. In light of this diversity, we surveyed the phenotype of 2,185 signature-tagged transposon mutants of χ7122 following intra-air sac inoculation of turkeys. This procedure identified novel APEC ST23 genes that play strain- and tissue-specific roles during infection. For example, genes mediating group 4 capsule synthesis were required for the virulence of χ7122 and were conserved in IMT2125 but absent from APEC O1. Our data reveal the genetic diversity ofE. colistrains adapted to cause the same avian disease and indicate that the core genome of the ST23 lineage serves as a chassis for the evolution ofE. colistrains adapted to cause avian or human disease via acquisition of distinct virulence genes.

scholarly journals Occurrence of Potentially Human-Pathogenic Escherichia coli O103 in Norwegian Sheep

2013 ◽  
Vol 79 (23) ◽  
pp. 7502-7509 ◽  
Author(s):  
Camilla Sekse ◽  
Marianne Sunde ◽  
Petter Hopp ◽  
Torkjel Bruheim ◽  
Kofitsyo Sewornu Cudjoe ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Human Pathogens ◽  
Outbreak Strain ◽  
Banding Patterns ◽  
Sheep Population ◽  
Content Type ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Uremic Syndrome ◽  
Low Prevalence

ABSTRACTThe investigation of an outbreak of hemorrhagic-uremic syndrome in Norway in 2006 indicated that the outbreak strainEscherichia coliO103:H25 could originate from sheep. A national survey of the Norwegian sheep population was performed, with the aim of identifying and describing a possible reservoir of potentially human-pathogenicE. coliO103, in particular of the H types 2 and 25. The investigation of fecal samples from 585 sheep flocks resulted in 1,222E. coliO103 isolates that were analyzed for the presence ofeaeandstxgenes, while a subset of 369 isolates was further examined for flagellar antigens (H typing),stxsubtypes,bfpA,astA, and molecular typing by pulsed-field gel electrophoresis (PFGE). The total ovineE. coliO103 serogroup was genetically diverse by numbers of H types, virulotypes, and PFGE banding patterns identified, although a tendency of clustering toward serotypes was seen. The flocks positive for potentially human-pathogenicE. coliO103 were geographically widely distributed, and no association could be found with county or geographical region. The survey showed thateae-negative,stx-negativeE. coliO103, probably nonpathogenic to humans, is very common in sheep, with 27.5% of flocks positive. Moreover, the study documented a low prevalence (0.7%) of potentially human-pathogenic Shiga toxin-producingE. coliO103:H2, while STEC O103:H25 was not detected. However, 3.1% and 5.8% of the flocks were positive for enteropathogenicE. coliO103 belonging to H types 2 and 25, respectively. These isolates are of concern as potential human pathogens by themselves but more importantly as possible precursors for human-pathogenic STEC.

scholarly journals Genomic Diversity and Virulence Profiles of Historical Escherichia coli O157 Strains Isolated from Clinical and Environmental Sources

2014 ◽  
Vol 81 (2) ◽  
pp. 569-577 ◽  
Author(s):  
Lydia V. Rump ◽  
Narjol Gonzalez-Escalona ◽  
Wenting Ju ◽  
Fei Wang ◽  
Guojie Cao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
The United States ◽  
Genomic Diversity ◽  
Severe Illness ◽  
Pathogenic Potential ◽  
Content Type ◽  
E Coli ◽  
Virulence Markers ◽  
Virulence Potential ◽  
Food Borne

ABSTRACTEscherichia coliO157:H7 is, to date, the majorE. coliserotype causing food-borne human disease worldwide. Strains of O157 with other H antigens also have been recovered. We analyzed a collection of historic O157 strains (n= 400) isolated in the late 1980s to early 1990s in the United States. Strains were predominantly serotype O157:H7 (55%), and various O157:non-H7 (41%) serotypes were not previously reported regarding their pathogenic potential. Although lacking Shiga toxin (stx) andeaegenes, serotypes O157:H1, O157:H2, O157:H11, O157:H42, and O157:H43 carried several virulence factors (iha,terD, andhlyA) also found in virulent serotypeE. coliO157:H7. Pulsed-field gel electrophoresis (PFGE) showed the O157 serogroup was diverse, with strains with the same H type clustering together closely. Among non-H7 isolates, serotype O157:H43 was highly prevalent (65%) and carried important enterohemorrhagicE. coli(EHEC) virulence markers (iha,terD,hlyA, andespP). Isolates from two particular H types, H2 and H11, among the most commonly found non-O157 EHEC serotypes (O26:H11, O111:H11, O103:H2/H11, and O45:H2), unexpectedly clustered more closely with O157:H7 than other H types and carried several virulence genes. This suggests an early divergence of the O157 serogroup to clades with different pathogenic potentials. The appearance of important EHEC virulence markers in closely related H types suggests their virulence potential and suggests further monitoring of those serotypes not implicated in severe illness thus far.

scholarly journals Global Extraintestinal Pathogenic Escherichia coli (ExPEC) Lineages

2019 ◽  
Vol 32 (3) ◽  
Author(s):  
Amee R. Manges ◽  
Hyun Min Geum ◽  
Alice Guo ◽  
Thaddeus J. Edens ◽  
Chad D. Fibke ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Surveillance Systems ◽  
Inclusion Criteria ◽  
Prevention Strategies ◽  
Content Type ◽  
E Coli ◽  
Treatment And Prevention ◽  
Pathogenic Escherichia Coli ◽  
Sequence Types ◽  
Study Inclusion

SUMMARY Extraintestinal pathogenic Escherichia coli (ExPEC) strains are responsible for a majority of human extraintestinal infections globally, resulting in enormous direct medical and social costs. ExPEC strains are comprised of many lineages, but only a subset is responsible for the vast majority of infections. Few systematic surveillance systems exist for ExPEC. To address this gap, we systematically reviewed and meta-analyzed 217 studies (1995 to 2018) that performed multilocus sequence typing or whole-genome sequencing to genotype E. coli recovered from extraintestinal infections or the gut. Twenty major ExPEC sequence types (STs) accounted for 85% of E. coli isolates from the included studies. ST131 was the most common ST from 2000 onwards, covering all geographic regions. Antimicrobial resistance-based isolate study inclusion criteria likely led to an overestimation and underestimation of some lineages. European and North American studies showed similar distributions of ExPEC STs, but Asian and African studies diverged. Epidemiology and population dynamics of ExPEC are complex; summary proportion for some STs varied over time (e.g., ST95), while other STs were constant (e.g., ST10). Persistence, adaptation, and predominance in the intestinal reservoir may drive ExPEC success. Systematic, unbiased tracking of predominant ExPEC lineages will direct research toward better treatment and prevention strategies for extraintestinal infections.

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