Serogroups, subtypes and virulence factors of shiga toxin-producing Escherichia coli isolated from human, calves and goats in Kerman, Iran

Aim: The present study was conducted to detect the occurrence, serogroups, virulence genes and phylogenetic relationship of shiga toxin-producing Escherichia coli [STEC] in human, clave and goat in Kerman [southeast of Iran]

Background: STEC have emerged as the important foodborne zoonotic pathogens causing human gastrointestinal disease and confirming the risk to public health

Methods: A total of 671 fecal samples were collected from diarrheic patients [n=395] and healthy calves [n=156] and goats [n=120] and screened for the presence of stx gene. Furthermore, the prevalence of stx1 and stx2 variants, serotypes [O157, O145, O103, O26, O111, O91, O128, and O45], phylogenetic groups and the presence of ehxA, eae, hylA, iha and saa virulence genes were studied

Results: Prevalence of STEC in human diarrheic isolates was 1.3% [5 isolates], in claves was 26.3% [41 isolates] and in goats was 27.5% [33 isolates]. stx1 gene was the most prevalent variant and detected in 75 isolates. Furthermore, stx1c was the most predominant stx subtype, found in 56 isolates. The ehxA identified in 36 [45.6%] isolates, followed by iha 5 [6.3%], eaeA 4 [5.1%], hlyA 2 [2.5%] and saa 2 [2.5%]. Most of the isolates belonged to phylogroup B1. Only two O26 and one O91 isolates were detected in our study

Conclusion: Our results show that STEC strains were widespread among healthy domestic animals in the southeast of Iran

Phylogenetic groups, extended-spectrum beta-lactamases and metallo- beta-lactamase in Escherichia coli isolated from fecal samples of patients with diarrhea in Iran

The aims of this study were to investigate the phenotypic and genotypic of extended-spectrum beta-lactamase [ESBL] and metallo-beta-lactamases [MBLs] and determine phylogenetic background E. coli isolates from fecal samples of patients with diarrhea in Kerman, southeast of Iran The emergence of ESBLs and MBLs-producing E. coli caused problems in antibiotic treatments. E. coli strains can be assigned to four main phylog-groups, including: A, B1, B2 and D. E. coli isolates [n=216] were obtained from fecal samples of patients with diarrhea between June and December 2013. ESBLs and MBLs were confirmed by disk-diffusion and broth micro-dilution methods. Using PCR, the ESBL-positive isolates were screened to determine the phylo-groups and the presence of bla[CTX-M-15], bla[OXA-1], bla[PER-1], bla[VIM]and bla[IMP] genes. ESBL-positive isolates [n= 56] were detected. Among ESBL-positive isolates, 51 isolates were positive for bla[CTX-M15] and one isolate was positive for both bla[CTX-M-15] and bla[OXA-1] genes. None of the isolates were positive for bla[PER-1], bla[VIM]and bla[IMP] genes. PCR assay for phylotyping of isolates indicated that the isolates were belonged to groups A [54.16%], B1 [11.11%], B2 [12.96%] and D [21.75%]. The isolates possessed bla[CTX-M-15] gene were belonged to A [35 isolates], B1 [5], B2 [3] and D [8] phylo-groups. Our results indicate that bla[CTX-M-15] gene is widespread among diarrheagenic E. coli isolates. ESBLproducing E. coli isolates were disseminated among a diversity of phylo-groups. Further studies are necessary to identify the ESBL genes in relation to phylogenetic groups