Prevalence of Shiga toxin-producing Escherichia coli isolated from chicken meat in west of Iran

Abstract

Objective: Shiga toxin producing Escherichia coli (STEC) has known as a crucial zoonotic food borne pathogen. A total of 257 row chicken meat samples were collected from different markets in Hamadan city from January 2016 to May 2017. Samples were cultured on selective and differential culture media, and the virulence genes of E. coli isolates were analyzed by PCR assay. The antibiotic resistance patterns of E. coli isolates were determined by disk diffusion method. The genetic relatedness of STEC isolates were analyzed by ERIC-PCR. Results: Totally, 93(36%) of isolates were identified as E. coli in this current study. According serological and microbiological tests, 5(5.3%), 31(33.3%) and 7(7.5%) of E. coli isolates, characterized as Enterohemorrhagic E. coli (EHEC), STEC and attaching and effacing E. coli (AEEC) strains, respectively. High level resistance to tetracycline (89.8), ampicillin (82.8%) and sulfametoxazole-trimotoprime (71%) were detected among E. coli isolates. Analysis of ERIC-PCR results showed five different ERIC types among EHEC isolates. Based on our findings, chicken meat identified as a sources of STEC strains, therefore, the controlling and checkup the chicken meats for the resistance and virulent strains of E. coli should be consider as a crucial issues in public health.

Diffusely adherent and cyclomodulin- positive Escherichia coli are associated with colon diseases

“…In agreement with report of Zarei et al (21), the highest frequency of bio lm formation was observed in isolates belonging to B2 and A phylogroups and no signi cant difference was found between different groups for bio lm formation. However, they mostly detected weak or moderate bio lms in isolates (21), but in our study, weak bio lm or lack of bio lm formation was dominant Altogether, discrepancies observed between different studies may be accounted for the type of specimen (biopsy vs fecal samples), diagnostic method (culture vs molecular methods) and inclusion of patients in different stages of disease. Additionally, although stool samples in this study obtained few days after colonic lavage in order to remove its adverse effect on microbiome, role of colonic lavage on microbial alteration cannot be ignored, There are some limitations in this study including low number of sample size, failure to follow up patients, use of limited centers for diagnosis of IBD and CRC patients which may in uence on the results.…”

“…About bio lm formation, most of the isolates (75%) were not bio lm producers and there was not any differences between two groups for ability of bio lm formation (Table 3) Table 3 Discussion This study showed that the most frequent E. coli from patients with colon diseases, belonged to phylogroup B2 which is in agreement with some other studies (1,5,21). Phylogenetic groups of E.coli, have been developed according to the acquisition of virulence factors (2).…”

“…It has been con rmed that bio lm production in some intestinal micro ora can be a natural process (11,21). In agreement with report of Zarei et al (21), the highest frequency of bio lm formation was observed in isolates belonging to B2 and A phylogroups and no signi cant difference was found between different groups for bio lm formation. However, they mostly detected weak or moderate bio lms in isolates (21), but in our study, weak bio lm or lack of bio lm formation was dominant Altogether, discrepancies observed between different studies may be accounted for the type of specimen (biopsy vs fecal samples), diagnostic method (culture vs molecular methods) and inclusion of patients in different stages of disease.…”

“…More importantly, by stimulation of TNF-a release, the chuA ,may promote intestinal dysbiosis involved in colon diseases (5). Similar to our results, phylogroups B2 and A were abundantly distributed among isolates from CRC and IBD patients in Zarei et al study (21). Therefore, association of IBD and carcinogenesis could be hypothesized (22).…”

“…Bio lm formation assay was carried out using the microtiter plate method as described previously using 2% crystal violet (21). The absorbance of stained wells was measured at 570 nm.…”