Pathotyping and evaluation of multidrug resistancepattern in E.coli strains isolated from chicken meat retail stores in Shiraz

Escherichia coli is one of the most important members of the Enterobacteriaceae family and is a factor in causing generalized bacillosis in birds, followed by gastrointestinal upset in humans. The aim of this study was to investigate the antibiotic resistance and pathotyping of Escherichia coli isolated from chicken meat stores in Shiraz. In this cross-sectional descriptive study, the rectum of 183 chickens offered in chicken meat shops was sampled. After phenotypic diagnosis, 16S rRNA specific primers were used for genotypic confirmation.  Antibiogram test was performed for Escherichia coli samples by using disk diffusion method based on CLSI standard tables.Then, with PCR test and using specific primers of eae, LT, aatA, ipaH, stx genes, different pathotypes were isolated from each other. Using phenotypic and genotypic tests, 100(55%)  Escherichia coli samples were isolated. The frequencies of isolated pathotypes were EPEC (34%), ETEC (26%), EIEC (23%), EHEC (10%) and EAEC (7%), respectively. Antibiogram testing of Escherichia coli isolates showed that the highest antibiotic resistance was related to tetracycline (83%) and the lowest resistance in all pathotypes was related to gentamicin (10%). Also, the study of multiple resistance patterns showed that ETEC pathotype had the highest multiple drug resistance with 96%. The results of this study confirmed the transmission of various Escherichia coli pathotypes from farm animals to humans. Therefore, correct and timely diagnosis and treatment can prevent their spread in the community.