scholarly journals Genotype Cluster Analysis in PathogenicEscherichia coliIsolates Producing Different CDT Types

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Maryam Javadi ◽  
Mana Oloomi ◽  
Saeid Bouzari

Diarrheagenic and uropathogenicE. colitypes are mainly characterized by the expression of distinctive bacterial virulent factors.stx1,stx2(Shiga toxins), andcdt(cytolethal distending toxin) genes have been acquired by horizontal gene transfer. Some virulent genes such asespP(serine protease),etpD(part of secretion pathway), andkatP(catalase-peroxidase), orsfpAgene (Sfp fimbriae), are on plasmids and the others likefliC(flagellin) and thefimHgene (fimbriae type-I) are located on chromosome. Genomic pathogenicity islands (PAIs) carry some virulent genes such ashlygene. To determine the existence of virulence genes incdtclinical isolates, genes includingstx1,stx2,cdt,hly,espP,katP,sfpA,etpD,fliC, andfimHwere assessed by Polymerase Chain Reaction (PCR). The most prevalent isolates foretpDandkatPgenes were 85.7% incdtII.katPgene was also observed 83.3% incdtI. However, in 42.85% ofcdtIIIisolates,espPgene was the most detected. Moreover,hlygene was also the most prominent gene incdtIII(71.42%).sfpA genewas observed in 66.6% ofcdtV.stx1gene was detected in 100% ofcdtII,cdtIV, andcdtVtypes. Presence and pattern of virulence genes were considered amongcdtpositive isotypes and used for their clustering and profiling.

2018 ◽  
Vol 120 (12) ◽  
pp. 2912-2923
Author(s):  
Evelyne Toe ◽  
Adjéhi Dadié ◽  
Etienne Dako ◽  
Guillaume Loukou ◽  
Marcelin Koffi Dje ◽  
...  

Purpose Vegetable salads, despite their recognized health benefits, are an increasingly common cause of foodborne illness worldwide. The purpose of this paper is to determine the prevalence of E. coli with virulence genes in ready-to-eat raw mixed vegetable salads sold in collective catering in Abidjan. Design/methodology/approach A total of 436 strains of E. coli were isolated from 306 ready-to-eat raw mixed vegetables salads and then identified biochemically and molecularly based on the uidA gene responsible for beta-glucuronidase activity. The virulence genes were determined by polymerase chain reaction. Findings The prevalence in vegetable salads of E. coli with virulence genes was 35.3 percent. The distribution of pathovars was 21.2 percent enterotoxigenic (ETEC), 4.9 percent enteropathogenic (EPEC), 0.7 percent Shigatoxigenic (STEC), and 7.5 percent Enteroaggregative E. coli (EAEC). It appears from the study that vegetable salads sold in collective catering in Abidjan are at risk for contamination by E. coli pathovars. Originality/value Processing conditions for these salads during preparation appear to be hygienically insufficient, so measures to control the risk of contamination are necessary.


Author(s):  
J. N. Silva ◽  
M. D. Baliza ◽  
F. Freitas ◽  
E. S Cruz ◽  
V. M. A. Camilo ◽  
...  

Abstract Many Solidarity Economic Venture (SEV) are family farmers who seek to add value to production through artisanal processing, which can lead to food contamination. Thus, this study aimed to genotypically characterize thermotolerant coliforms (TtC) strains from food produced by local agribusinesses of SEV during January to April 2019. Samples from thirteen production units (PU) from the SEV were submitted to a microbiological analysis of thermotolerant coliforms (AFNOR 3M1/2 – 09/89), using a fast count method in Petrifilm™ dishes. The Polymerase Chain Reaction (PCR) technique was used to verify the following virulence genes (VGs) associated with Escherichia coli: stx, typical from enterohemorrhagic E. coli (EHEC); bfpA typical from entheropathogenic E. coli (EPEC) and elt and slt, typical from entherotoxigenic E. coli (ETEC). The results showed that two samples of queijadinha (typical Brazilian candy made with eggs and coconut) and one sample of cassava cake presented characteristic colonies TtC. This way, three strains were isolated in order to perform the PCR technique. However, the genes used in the reaction were not detected in the isolated strains. Therefore, it is suggested that the isolated strains are from E. coli pathotypes with different virulence genes than the ones analyzed belong other types of TtC, such as Enterobacter and Klebsiella. Although the virulence of genes has not been confirmed, the presence of TtC on food indicates hygiene flaws during production and, therefore, measurements to control and prevent contamination should be taken.


2021 ◽  
Vol 72 (3) ◽  
pp. 3147
Author(s):  
F PEHLIVANOGLU

Livestock is an important reservoir of Shiga toxin-producing Escherichia coli and enterohemorrhagic E. coli (STEC/EHEC) strains and acts as a significant source of transmission to humans. In addition to the virulence of STEC/EHEC isolates, antibiotic resistance is also an escalating problem in these bacteria and increases the risk to public health. Therefore, the present study aimed to explore E. coli O157:H7 serotype and STEC/EHEC virulence genes in AmpC- and extended-spectrum beta-lactamase (ESBL)-producing E. coli isolates from cattle, chicken and sheep. A total of 61 confirmed AmpC- or ESBL-producing E. coli isolates were screened for the virulence genes (stx1, stx2, eae, ehxA, espP, katP and saa) and E. coli O157 (rfbO157) and H7 (fliCH7) genes by polymerase chain reaction (PCR). None of the ESBL-producing E. coli was positive for these genes, but six multidrug-resistant AmpC-producing E. coli were positive for the fliCH7 gene only. When considering the function of the H7 flagellar antigen of E. coli, it may be concluded that the development of ESBL/AmpC beta-lactamase production in the E. coli isolates with H7 flagella, which reside in the chicken intestine, may be potentially important for public health regarding both virulence and antimicrobial resistance.


2019 ◽  
Vol 12 (2) ◽  
pp. 224-230 ◽  
Author(s):  
Hosterson Kylla ◽  
Tapan K. Dutta ◽  
Parimal Roychoudhury ◽  
Prasant K. Subudhi

Aim: This study aimed to study the prevalence of the coinfection of enteric bacterial and viral pathogens, namely Escherichia coli, Salmonella, Rotavirus, and Picobirnavirus from fecal samples of pre-weaned piglets in Northeast region of India. Materials and Methods: A total of 457 fresh fecal samples were collected from piglets under 9 weeks old during 2013-2015 from organized (n=225) and unorganized (n=232) farms of Manipur, Meghalaya, Mizoram, and Nagaland. Samples were collected from diarrheic (n =339) and non-diarrheic (n=118) piglets including local indigenous (n=130) and crossbreed (n=327) piglets in different seasons during the study period. The samples were processed for the isolation of E. coli and Salmonella and detection of their putative virulence genes by polymerase chain reaction (PCR). Samples were also processed for the detection of Rotavirus and Picobirnavirus by RNA-polyacrylamide agarose gel electrophoresis and reverse transcriptase-PCR (RT-PCR). Results: A total of 11 (2.40%) samples were found positive for two or more coinfecting enteric bacterial and viral pathogens. All the 11 positive fecal samples were recovered from diarrheic piglets. Salmonella Typhimurium (enterotoxin, stn gene) and Picobirnavirus genogroup 1 were found to be more frequent as coinfecting agents. Coinfection was recorded higher in unorganized (3.87%) compared to organized farm (0.88%). Again, higher detection was recorded in crossbreed (2.75%) than local indigenous piglets (1.53%). The occurrence of coinfection was found to be more common during summer (4.68%) followed by winter (2.27%) season. Conclusion: The present study highlighted the significance of E. coli, Salmonella, Rotavirus, and Picobirnavirus as important diarrheagenic pathogens causing coinfection in piglets in Northeast region of India. Probably, this is the first systematic study of the coinfection of four important diarrheagenic bacterial and viral agents associated with piglet diarrhea in India.


2018 ◽  
Vol 48 (2) ◽  
Author(s):  
Fernanda Morcatti Coura ◽  
Amanda Nadia Diniz ◽  
Carlos Augusto Oliveira Junior ◽  
Andrey Pereira Lage ◽  
Francisco Carlos Faria Lobato ◽  
...  

ABSTRACT: This study identified the virulence genes, pathovars, and phylogenetic groups of Escherichia coli strains obtained from the feces of dogs with and without diarrhea. Virulence genes and phylogenetic group identification were studied using polymerase chain reaction. Thirty-seven E. coli isolates were positive for at least one virulence factor gene. Twenty-one (57.8%) of the positive isolates were isolated from diarrheal feces and sixteen (43.2%) were from the feces of non-diarrheic dogs. Enteropathogenic E. coli (EPEC) were the most frequently (62.2%) detected pathovar in dog feces and were mainly from phylogroup B1 and E. Necrotoxigenic E. coli were detected in 16.2% of the virulence-positive isolates and these contained the cytotoxic necrotizing factor 1 (cnf1) gene and were classified into phylogroups B2 and D. All E. coli strains were negative for the presence of enterotoxigenic E. coli (ETEC) enterotoxin genes, but four strains were positive for ETEC-related fimbriae 987P and F18. Two isolates were Shiga toxin-producing E. coli strains and contained the toxin genesStx2 or Stx2e, both from phylogroup B1. Our data showed that EPEC was the most frequent pathovar and B1 and E were the most common phylogroups detected in E. coli isolated from the feces of diarrheic and non-diarrheic dogs.


Author(s):  
Ehssan H. Moglad ◽  
Omima Abdl El Jalil Adam ◽  
Maram M. Alnosh ◽  
Hisham N. Altayb

Abstract This study aimed to determine the prevalence of virulence genes in all the diarrheagenic Escherichia coli DEC strains (EAEC, EHEC, EIEC, EPEC, and ETEC) isolated from drinking water from Khartoum State, Sudan. A total of 46 drinking water samples obtained from different water sources were analyzed for the presence of E. coli as fecal contamination indicator and the antimicrobial-resistant pattern of isolated E. coli DEC strain was investigated. The bacterial genomic DNA was used as a template for multiplex polymerase chain reaction (MPCR) for the detection of the EHEC (stx gene), EIEC (ipaH gene), EPEC (eae gene), and EAEC (aggR gene) as virulence and biomarker genes. Our results showed that ipaH gene was found in 41.3% (19/46) of isolates, and aggR gene detected in 30.4% (14/46) of isolates. Both aggR and ipaH were found positive in 9 (19.5%) isolates and as well the combination of aggR and stx genes were detected in 2 (4.3%) isolates. In conclusion, this report confirmed the presence of DEC strains in drinking water from different resources and locations. Such findings require separate future clinical research studies to examine waterborne pathogens that exist in this state's water and find a management solution to stop or avoid potential outbreaks.


2004 ◽  
Vol 132 (1) ◽  
pp. 77-85 ◽  
Author(s):  
A. M. O'CONNOR ◽  
K. A. ZIEBELL ◽  
C. POPPE ◽  
S. A. McEWEN

Using a self-paired observational study, the association between therapeutic oxytetracycline use and the prevalence of virulence genes in commensal Escherichia coli (E. coli) from cattle was examined. Faeces were collected from 39 yearling bulls prior to and after treatment with oxytetracycline and from 44 untreated animals. Between samplings all animals received in-feed chlortetracycline for 16 days. Five E. coli were isolated from each sample and tested by a polymerase chain reaction (PCR) capable of detecting all verotoxin (vt) genes. Positive isolates were further tested with a multiplex PCR to detect vt1, vt2, eaeA and hlyA. For vt, 23 animals were positive at both samplings, 26 negative at both samplings, 22 negative animals became positive and 12 positive animals became negative. Sixty-eight per cent of the discordant pairs changed from vt-negative to vt-positive (95% CI 48–80) suggesting pressure toward becoming vt-positive perhaps due to the transfer of genes due to mixing of cattle in the months between samplings or an effect of chlortetracycline.


2017 ◽  
Vol 11 (07) ◽  
pp. 549-556 ◽  
Author(s):  
Hajer Kilani ◽  
Mohamed Salah Abbassi ◽  
Sana Ferjani ◽  
Rakia Ben Salem ◽  
Riadh Mansouri ◽  
...  

Introduction: The virulent Escherichia coli strains responsible for extraintestinal infections were mainly belonged to B2 and D phylogroups. However, no past studies have determinate via the presence of virulence genes the frequency of E. coli pathovars recovered from animals housed in farms in Tunisia. The aims of this study were to investigate 26 E. coli isolated from healthy and diarrheic animals and to determinate via the presence of virulence genes the frequency of pathovars. Methodology: Twenty-six E. coli isolates of phylogroups B2 (n = 14), B22 (n = 9), B23 (n = 5), and D2 (n = 12) were characterized. Genes encoding virulence factors (fimH,eaeA,aggC,papC, papG allele III, hlyA, east1, cnf1, exhA,stx1, stx2, iutA, fyuA, ibeA,and ipaH), and antibiotic resistance as well as class 1 and 2 integrons were searched by polymerase chain reaction (PCR). The genetic relationship of isolates was done by PFGE. Results: According to the occurrence of specific genes the 26 isolates were classified as:9 EAEC, 2 EHEC, 4 UPEC, 3 EPEC/EHEC and 1 NTEC. Therefore, 2 Ex-PEC and 5 APEC were presented amongst our strains. Some isolates (12) were clonal and the remaining was unrelated. Conclusions: Higher diversity of pathovars which carried diverse combinations of virulence genes in healthy isolates. In addition, it seems that the infections were caused by different mechanisms.


2015 ◽  
Vol 9 (02) ◽  
pp. 165-174 ◽  
Author(s):  
Casmir Ifeanyichukwu Cajetan Ifeanyi ◽  
Nkiruka Florence Ikeneche ◽  
Bassey Enya Bassey ◽  
Nazek Al-Gallas ◽  
Ridha Ben Aissa ◽  
...  

Introduction: Escherichia coli are frequently isolated from diarrheic children in the Federal Capital Territory Abuja, Nigeria, but their virulent properties are not routinely evaluated. Therefore, the etiology of childhood diarrheal disease attributable to diarrheagenic Escherichia coli (DEC) in Abuja, Nigeria remains unknown. Methodology: Stool specimens from 400 acute diarrheic children between 0 and 60 months of age were studied.E. coli strains isolated were evaluated by polymerase chain reaction (PCR) for nine virulence genes and HEp-2 cell adherence to detect and identify five distinct diarrheagenic E. coli categories. Results: Diarrheagenic E.coli was detected in 51 (12.8%) of the diarrheic children. The observed DEC pathotypes were enteropathogenic E. coli (EPEC) in 18 (4.5%) children, enterotoxigenic E. coli (ETEC) in 16 (4.0%), enteroaggrative E. coli (EAEC) in 8 (2.0%), enterohaemorrhagic E. coli (EHEC) in 6 (1.5%), and enteroinvasive E. coli (EIEC) in 3 (0.8%). Four (1.0 %) EPEC strains with only the eae+ gene that adhered diffusely to HEp-2 cell were identified as atypical EPEC. All the DEC categories except atypical EPEC were identified in children between 6 and 12 months of age. Conclusions: This study underscores the need for routine evaluation of diarrheic children for virulence properties of infectious DEC. Atypical EPEC are emerging among the DEC pathotypes isolated from childhood acute gastroenteritis in Abuja, Nigeria.


Sign in / Sign up

Export Citation Format

Share Document