Submitted to: International Association for Food Protection
Publication Type: Abstract Only
Publication Acceptance Date: August 14, 2005
Publication Date: August 14, 2005
Citation: Bailey, J.S., Cray, P.J., Berrang, M.E. 2005. ANTIMICROBIAL RESISTANCE PROFILES OF SALMONELLA, CAMPYLOBACTER, AND E. COLI FROM CHICKENS WITHOUT EXPOSURE TO ANTIBIOTICS. International Association for Food Protection. August 14 -17, 2005. Baltimore, MD. Technical Abstract: The antibiotic resistance profiles of Salmonella, Campylobacter, and E. coli from retail broiler chickens reared without exposure to subtherapeutic or therapeutic antibiotics were determined. For Salmonella and E. coli, resistance profiles to the antibiotics used in the National Antimicrobial Resistance Monitoring System (NARMS) were compared to those previously reported for NARMS poultry isolates. Overall resistance of Salmonella isolates from chickens reared free of antimicrobials was less than observed in poultry isolates from NARMS. Only ampicillin resistance was found more frequently among the current study isolates and this was attributed to one sampling period from one company. Overall, E. coli isolates also demonstrated less resistance than NARMS isolates with the exception of kanamycin and trimethoprim/sulfamathoxazole which were resistant at approximately the same levels as NARMS isolates. Campylobacter were tested for resistance to eight antimicrobials. Campylobacter jejuni from chickens reared free of antimicrobials were susceptible to azithromycin, clindamycin, and eythromycin. Resistance was only observed for ciprofloxacin (n=33; 15.2%), naladixic acid (n=33; 15.2%), and tetracycline (n=33; 48.5%). Overall, isolates of C. coli were more resistance than isolates of C. jejuni. While less antimicrobial resistance was observed in isolates from chickens reared without exposure to antibiotics, resistance was still observed for all major classes of antimicrobials. This suggests that rearing of chickens without antimicrobials decreases, but does not eliminate, the prevalence of resistance.