Antimicrobial susceptibility of Escherichia coli Isolated from Iranian broiler chicken flocks, 2005-2006

Abstract

Escherichia coli is a major pathogen of worldwide importance in commercially produced poultry, contributing significantly to economic losses in chickens and turkeys. One hundred thirty-five cases in broilers were examined and cultured for isolation and antimicrobial sensitivity evaluation of E. coll between January 2005 and December 2006. In 103 cases (76.3%) E. coli were isolated and in 32 cases (23.7%) no E. coli growth was observed. Multiple resistances were seen in all isolates. All isolates were uniformly resistant to Tiamuline, Tylosin, and Bacitracin. We observed low levels of resistance to Gentamicin (12%), Kanamycin (0%), and Florfenicol (39%). Percentages of resistance to Tiamuline, Bacitracin, Tylosin, Colistin, and Erythromycin (>99%); Tetracycline (96%); Oxytetracycline (93%); Flomequine (87%); Neomycine (87%); Lincospectin (79%); Difloxacin (78%); Enrofloxacin (76%); Cotrimoxazole (72%); Chloramphenicol (52%); and Ampicillin (49%) were determined. Our data show high levels of multiresistance among Iranian E. coli isolates. It seems that the pattern of antibiotic resistance of bacteria that are clinically important for the poultry industry should be monitored. ©2008 Poultry Science Association, Inc.