Study of Multiple-Drug Resistance Transfer Factors from Isolated E. coli of Poultry Farms to Salmonella typhimurium

Different studies on animals in around the world show that there are multiple-drug resistance in strains of Escherichia coli (E. coli). Such microorganisms are notorious for the extension of colibacillosis in poultry, which great economic losses bring for the poultry industry. This study was carried out to determine drug resistance and resistance factor transfer in E. coli strains isolated from poultry farms, in south west of Iran. Than 100 pieces of poultry carcasses from cases of colibacilosis twenty-five E. coli resistant to one or more antibiotics were isolated and were analyzed to determine their drug resistance pattern and also transfer of resistance factor via conjugation. The highest rate of resistance was against nalidixic acid and tetracycline. Multiple drug resistance was shown in 80% of strains. By using Salmonella typhimurium RITCC1730 (S. typhimurium) as a recipient and E. coli as donor’s resistance factor examined the transfer of drug resistance that the highest rate of transfer was related to neomycin and tiamulin 68% and 64%, respectively. Finally, we concluded that there are a substantially evidence of multiple drug resistance in E. coli isolates taken from poultry farms, so in our opinion restricting use of antibiotics and performing antimicrobial susceptibility tests to select suitable antibiotic can decrease developing of resistant strains.