Investigations of Escherichia coli O157 and some virulence genes in samples of meat and faeces from clinically healthy cattle in Turkey

2007 ◽  
Vol 161 (11) ◽  
pp. 392-394 ◽  
Author(s):  
H. Ongor ◽  
R. Kalin ◽  
B. Cetinkaya
2012 ◽  
Vol 60 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Domonkos Sváb ◽  
István Tóth

Long polar fimbriae (Lpf) are recently discovered adhesins and increasingly important genetic markers of pathogenicEscherichia colistrains. The presence and genotype diversity of Lpf operons was screened in a collection of 97Escherichia coliO157 strains representing different pathotypes, isolated from healthy cattle (n = 43) and human patients (n = 54) in several countries. Individual structural genes of Lpf were scanned by PCR, and allelic variants were detected with a recently developed typing scheme. Ninety-five strains carried at least one whole Lpf operon (geneslpfABCDand/orlpfABCDE). The 64 enterohaemorrhagic (EHEC) and 24 enteropathogenic (EPEC) strains all carried two Lpf operons, allele 3 oflpfA1and allele 2 oflpfA2, a combination characteristic of the O157:H7/NM serotype. Out of the 9 bovine atypical (AT;stx-, eae-) strains, 7 carried one complete Lpf operon, allele 1 oflpfA2. The atypical strains belonged to main phylogenetic groups A and B1, while the EHEC and EPEC strains were from group D. Lpf variants carried by the 72 strains of theEscherichia coliReference Collection (ECOR) were determined with the same typing scheme. Alleles were detected in 25 strains, of which 6 were found negative for the respective Lpf operons in earlier studies. The marker value of the Lpf allelic combination for the O157:H7/NM serotype was confirmed, and further evidence was given for the presence of at least two different genetic lineages of atypical bovineE. coliO157 strains.


2011 ◽  
Vol 77 (23) ◽  
pp. 8259-8264 ◽  
Author(s):  
José A. Orden ◽  
Pilar Horcajo ◽  
Ricardo de la Fuente ◽  
José A. Ruiz-Santa-Quiteria ◽  
Gustavo Domínguez-Bernal ◽  
...  

ABSTRACTSubtilase cytotoxin (SubAB) from verotoxin (VT)-producingEscherichia coli(VTEC) strains was first described in the 98NK2 strain and has been associated with human disease. However, SubAB has recently been found in two VT-negativeE. colistrains (ED 591 and ED 32). SubAB is encoded by two closely linked, cotranscribed genes (subAandsubB). In this study, we investigated the presence ofsubABgenes in 52 VTEC strains isolated from cattle and 209 strains from small ruminants, using PCR. Most (91.9%) VTEC strains from sheep and goats and 25% of the strains from healthy cattle possessedsubABgenes. The presence ofsubABin a high percentage of the VTEC strains from small ruminants might increase the pathogenicity of these strains for human beings. Some differences in the results of PCRs and in the association with some virulence genes suggested the existence of different variants ofsubAB. We therefore sequenced thesubAgene in 12 strains and showed that thesubAgene in most of thesubAB-positive VTEC strains from cattle was almost identical (about 99%) to that in the 98NK2 strain, while thesubAgene in most of thesubAB-positive VTEC strains from small ruminants was almost identical to that in the ED 591 strain. We propose the termssubAB1to describe the SubAB-coding genes resembling that in the 98NK2 strain andsubAB2to describe those resembling that in the ED 591 strain.


2020 ◽  
Vol 152 ◽  
pp. 15667-15675
Author(s):  
Chakirath Folakè Arikè Salifou ◽  
Cyrille Boko ◽  
Isidore Houaga ◽  
Raoul Agossa ◽  
Isabelle Ogbankotan ◽  
...  

Objectives: The study aimed to search for E. coli O157 and non-O157 in milk, meat and faeces of cattle, sheep and pigs slaughtered in Cotonou. Methodology and Results: One hundred and Seventy-Five (175) samples including 25 meat, 25 faeces per species and 25 milk from cattle were analysed for E. coli O157; O26 and O111 and the virulence genes were identified by PCR. The SAS software (1998) and the bilateral Z test were used to calculate and compare the identification frequencies. E. coli O157 was identified in 4% of cattle faeces, 4% of sheep faeces, and 20% of beef and, in 20% of milk samples. E. coli O26 was identified in 12% of cattle faeces and, in 8% of beef samples. E. coli O111 was identified at frequencies of 8%, and 12% in faeces of sheep and pigs, respectively. The eae gene was detected in 4% of beef, ovine meat, milk, pig faeces and in sheep faeces. stx1 was detected in 8% of milk, and in 4% of bovine and sheep faeces. The strains possessing the gene were all of E. coli O157 with the exception of one from pig faeces identified as O111. Conclusions and application of findings: The presence of these serogroups of E. coli with virulence genes poses a real food safety problem in Benin. This study findings must be taken into account for risk assessment and management related to the consumption of food of animal origin. Keywords: Benin, E. coli O157, O26, O111, faeces, meat, milk


2009 ◽  
Vol 26 (8) ◽  
pp. 865-871 ◽  
Author(s):  
Nikolaos Solomakos ◽  
Alexandros Govaris ◽  
Apostolos S. Angelidis ◽  
Spyros Pournaras ◽  
Angeliki Rothi Burriel ◽  
...  

2015 ◽  
Vol 78 (2) ◽  
pp. 264-272 ◽  
Author(s):  
CLAUDIA NARVÁEZ-BRAVO ◽  
ALEJANDRO ECHEVERRY ◽  
MARKUS F. MILLER ◽  
ARGENIS RODAS-GONZÁLEZ ◽  
M. TODD BRASHEARS ◽  
...  

The objective of the study was to characterize virulence genes and subtype Escherichia coli O157:H7 and O157:H(−) isolates obtained from a vertically integrated feedlot slaughter plant in Mexico. A total of 1,695 samples were collected from feedlots, holding pens, colon contents, hides, and carcasses. E. coli O157:H7 detection and confirmation was carried out using conventional microbiology techniques, immunomagnetic separation, latex agglutination, and the BAX system. A total of 97 E. coli O157 strains were recovered and screened for key virulence and metabolic genes using multiplex and conventional PCR. Eighty-eight (91.72%) of the strains carried stx2, eae, and ehxA genes. Ten isolates (8.25%) were atypical sorbitol-fermenting strains, and nine were negative for the flicH7 gene and lacked eae, stx1, stx2, and ehxA. One sorbitol-positive strain carried stx2, eae, tir, toxB, and iha genes but was negative for stx1 and ehxA. Pulsed-field gel electrophoresis (PFGE) analysis yielded 49 different PFGE subtypes, showing a high genetic diversity; however, the majority of the typical isolates were closely related (80 to 90% cutoff). Atypical O157 isolates were not closely related within them or to typical E. coli O157:H7 isolates. Identical PFGE subtypes were found in samples obtained from colon contents, feedlots, holding pens, and carcasses. Isolation of a sorbitol-fermenting E. coli O157 positive for a number of virulence genes is a novel finding in Mexico. These data showed that genetically similar strains of E. coli O157:H7 can be found at various stages of beef production and highlights the importance of preventing cross-contamination at the pre- and postharvest stages of processing.


2014 ◽  
Vol 53 (3) ◽  
pp. 986-990 ◽  
Author(s):  
Linda Chui ◽  
Vincent Li ◽  
Patrick Fach ◽  
Sabine Delannoy ◽  
Katarzyna Malejczyk ◽  
...  

Virulence markers in Shiga toxin-producingEscherichia coli(STEC) and their association with diseases remain largely unknown. This study determines the importance of 44 genetic markers for STEC (O157 and non-O157) from human clinical cases and their correlation to disease outcome. STEC isolated from a cattle surveillance program were also included. The virulence genes tested were present in almost all O157:H7 isolates but highly variable in non-O157 STEC isolates. Patient age was a significant determinant of clinical outcome.


2020 ◽  
Vol 8 (2) ◽  
pp. 55-59
Author(s):  
Fatemeh Binandeh ◽  
Mohammadreza Pajohi-Alamoti ◽  
Pezhman Mahmoodi ◽  
Azam Ahangari

Background and Objectives: Consuming raw or undercooked cattle meat is the most common transmission way of infection with Escherichia coli O157:H7. The present study aimed to identify virulence genes stx1, stx2, hlyA, and eaeA in E. coli isolated from meat samples (beef and mutton) in Hamedan during 2015 and 2016. Materials and Methods: For this purpose, the swabs were randomly taken from 160 meat samples including 80 beef samples and 80 mutton samples from butcher shops. Isolation and identification of E. coli cells were conducted by culturing the swab samples on MacConkey agar and Eosin methylene blue agar media. Then, the identity of the suspected E. coli O157:H7 colonies was investigated by a multiplex PCR assay and eventually, the isolates were evaluated for the presence of stx1, stx2, hlyA, eaeA virulence genes. Results: The results showed that out of 160 cultured samples on the selective media, 60 samples (37.5%) were contaminated with E. coli. O157:H7, O157, and H7 strains were identified using PCR, among which only E. coli O157:H7 possessed all four virulence factor encoding genes. Conclusion: The results of this study showed that beef could be a reservoir for E. coli O157:H7, and it may be involved in the transmission of this pathogen to humans.


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