Antibacterial Resistance Patterns of Escherichia coliIsolated from Broilers Colibacillosis of Broilers chicksin Golestan Province

The aim of this study was to determinate the drug resistance patterns of avian E.coli isolates from cases of colibacillosis in Golestan Province, Iran. One hundred and fifty isolates of E. coli from pericarditis lesions (5 samples per farm and in 30 farms) submitted to the microbiology laboratory. After sampling and confirmation by biochemical reactions, the E.coli isolates were tested for their susceptibility to a panel of 15 antibacterial agents using the Kirby-Bauer disc diffusion method. The drug susceptibility test showed that all isolates were resistant to Nalidixic acid, Erythromycin, Flumequine and were susceptible to Gentamicin and Ceftiofur. More than 80% of the isolates were resistant to Colistin, Tetracycline, Sulfadiazine + Trimethoprim, Enrofloxacin, Cyprofloxacin, Danofloxacin, Lincospectin, Difloxacin, Sulphachlorpyridazin + Trimethoprim and Doxycycline. There were 29 drug resistance patterns among 150 E.coli isolates. Eighty eight percent of isolates belonged to more than one pattern, whereas the rest (12%) of isolates, each isolate belonged to one pattern only. The results of this study confirmed the possibility of indiscriminate abuse and misuse of antibacterial agents in poultry industry and this could be dangerous for public health as well.