Virulence-Associated Gene Profiles of Avian Pathogenic Escherichia coli Isolated From Broilers With Colibacillosis: A Pilot Study in Iran

Avian pathogenic Escherichia coli (APEC) causes economic losses in the chicken industry worldwide. In this study, virulence-associated gene profiles of APEC isolates were investigated by polymerase chain reaction (PCR). A total of 60 Escherichia coli isolates were collected from 60 colibacillosis cases from 30 broiler poultry farms in Alborz, Tehran, and Golestan provinces, Iran. After identification by biochemical tests, DNA was extracted by boiling method and 5 virulence-associated genes including: iutA, hlyF, iroN, ompT, and iss were detected by 2 multiplex PCR protocols. Of the 60 APEC isolates, 26 (43.3%) isolates had at least three virulence genes from which 12 (20%) isolates were positive for all 5 virulence genes, whereas 34 (56.6%) carried no investigated virulence genes. Presence of iutA, hlyF, iroN, ompT, and iss genes in the APEC isolates were 17 (28.3%), 17 (28.3%), 24 (40%), 26 (43.3%), and 23 (38.3%), respectively. According to the results, four different virulence-associated gene profiles were seen in isolates, from which profile 1 with 12 (20%) isolates was predominant. These findings were in agreement with the previous reports.