title: Phylogenetic typing and detection of extended-spectrum β-lactamases in Escherichia coli isolates from broiler chickens in Ahvaz, Iran.
abstract: This study was conducted to reveal the phylogenetic background, to detect the genes encoding TEM, SHV and CTX-M-15 extended-spectrum β-lactamases (ESBL), and to analyze their distribution in phylo-groups of 150Escherichia coliisolates from broiler chickens in Ahvaz (Southwest of Iran). Seventy- five cloacal swabs from healthy birds (fecal isolates), and 75 heart blood samples from birds withcolibacillosis(septicemic isolates) were obtained. All isolates were phylotyped and screened for ESBL genes by polymerase chain reaction (PCR). The fecal isolates belonged to four main phylo-groups, including 41 isolates (54.67%) to A, 9 (12.00%) to B1, 5 (6.67%) to B2, and 20 (26.67%) to D. Of septicemic isolates, 37 isolates (49.33%) were classified as phylotype A, 5 (6.67%) as B1, 10 (13.33%) as B2, and 23 (30.67%) as D. In molecular analysis, a total of 72 isolates (35 fecal and 37 septicemic) were identified to harbor ESBL genes, which were distributed in phylo-groups A, B1, B2, and D. Regardless of the type of isolate,blaCTX-M-15gene was the most common genotype, followed byblaTEMandblaSHVgenes. This study suggests that broiler chickens in Iran are infected to ESBL genes- harboringEscherichia colistrains which may be spread to the food chain through fecal contamination of carcasses during slaughtering.
authors.affiliation: Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
authors.forename: Ramezan Ali
authors.initials: RA
authors.lastname: Jafari
authors.affiliation: Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Motamedi
authors.affiliation: Post Graduate Student, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
authors.forename: Elham
authors.initials: E
authors.lastname: Maleki
authors.affiliation: Department of Microbiology, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Ghanbarpour
authors.affiliation: Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
authors.forename: Mansoor
authors.initials: M
authors.lastname: Mayahi
keywords: Beta-lactamase; Chicken; Escherichia coli; Phylogeny