Antibiotical resistance of Escherichia coli isolates from broiler chickens in Chaharmahal Va Bakhtiari province.

Objectives: Colibacillosis caused by Escherichia coli. To prevent of Escherichia coli infection, it s necessary to determine resistance of bacteria to antibiotics. Disk diffusion method is one of the most common antibiogram methods. In this study we measured antibiotic resistance of E.coli isolates from broiler chickens in Chaharmahal Va Bakhtiari province during May 2013 to May 2014.Materials Methods: Sampling was made out of pericardial sac and liver of 550 dead birds referred to clinical department of Shahr-e-kord University, which affected to colibacillosis and then cultured according standard operation method. Antibiotical resistance to a panel of antibiotics was determined through disk diffusion method for 100 E. coli isolates. Due to bacterial resistance to antibiotics, diameter of lack growth halo varies. Results of antibiogram are reported to sensitive, intermediate and resistant.Results conclusion: The percentages of isolates that were resistant to 11 antibacterial agents during 2013-2014 were as follows: Erythromycin: 96%, Oxytetracycline: 84.2%, Danofloxacin: 72.5%, Difloxacine: 73.2%, Enrofloxacine: 70%, Doxycycline: 71%, Ciprofloxacine: 53.3%, Lincospectine: 41.4%, Sultrim: 58.6%, Florfenicole: 55.1% and Ampicillin: 44%.The association between the occurrence of resistance and the consumption of the antimicrobial is discussed. The present study highlights the prevalence of multiple drug resistant E.coli among healthy broiler chickens in mentioned province. The comparison of resistance patterns reported here with pervious investigations indicated that the resistance to some antibacterial agent among E.coli isolates from avian colibacillosis is on the rise and this may be of concern for poultry specialists.