Virulence – associated genes in Escherichia coli isolates from poultry with colibacillosis in Iran

Objectives: The colibacillosis caused by avian pathogenic Escherichia coli (APEC) is responsible for a major loss of productivity and mortality in the poultry industry. APEC pathogenesis is based on the presence and expression of several virulence factors. The aim of the present study was to investigate the presence of some virulence - associated genes in Escherichia coli isolated from colibacillosis cases.Materials and Methods:In total ۱۳۶ Escherichia coli isolates were collected from farms located around central regions of Iran including Karaj, Eshtehard, Hashtgerd, Arak, Komijan, Hamedan and Qahavand cities. Bacterial DNA was extracted and ۸ virulence-associated genes including: astA,fimH, irp۲, iutA, fyuA, tsh, vat and ibeA were detected by two sets of multiplex PCR. Results: The prevalence of astA, fimH, irp۲, iutA, fyuA, tsh, vat and ibeA were ۲۷.۹۴, ۱۰۰, ۶۶.۱۷, ۸۵.۲۹, ۸۸.۲۳, ۵۱.۴۷, ۳۶.۷۶ and ۲۶.۴۷%, respectively. In addition, ۱(۰.۷۳%), ۵ (۳.۶۷%), ۲۰ (۱۴.۷%), ۲۳ (۱۶.۹۱%), ۴۰ (۲۹.۴۱%), ۳۶ (۲۶.۴۷) and ۱۱ (۸.۰۸) isolates had ۱, ۲, ۳, ۴, ۵, ۶, ۷ virulence genes, respectively. In addition, no isolates were positive for all ۸ virulence genes.Conclusions:These findings provide novel insights into the presence and distribution of some virulence-associated genes in avian pathogenic Escherichia coli strains isolated from Iran. These data will help to more comprehensively characterize APEC in future epidemiological studies.

کلیدواژه ها:

Virulence-associated genes ، APEC ، Escherichia coli ، Poultry ، Colibacillosis