|Byrd, James - Allen|
Submitted to: Journal of Food Protection
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/13/2003
Publication Date: 8/20/2003
Citation: Roe, M.T., Byrd II, J.A., Smith, D.P., Pillai, S.D. 2003. Class 1 and class 2 integrons in poultry carcasses from broiler house and poultry processing environments. Journal of Food Protection. 66:1426-1431. Interpretive Summary: Escherichia coli and Salmonella are important food poisoning microorganisms that cause potentially fatal disease in humans. These bacteria and other bacteria contain genetic materials (called integrons) that may allow the bacteria to survive in the presence of bacteria killing drugs called antimicrobials. A mixture of bacteria were taken from chickens at slaughter plants and evaluated for the presence of several types/classes of integrons. The results of this study suggest that bacteria containing several different types of integrons survive exposure to chlorine in chilled water immersion tanks. The presence of these integrons may allow the bacteria containing them to survive a critical step in the decontamination process within slaughter plants. These results show that bacteria containing these integrons may be responsible for antimicrobial resistance of pathogens found in poultry and poultry products. This work will help scientists to have a better understanding on how bacteria continue to exist on poultry meat and may help develop a program that could provide a safer product to the consumer.
Technical Abstract: Integron gene sequences have been identified as major genetic contributors to the dissemination of antimicrobial resistance in bacteria. The objective of this study was to examine the prevalence of integron sequences in poultry processing at the broiler house and in processing plants. The results indicate that class 1 and class 2 integron sequences can be found throughout the entire processing environment. Of the two classes, the class 1 integron was the most prevalent throughout all areas of processing. Both classes of integrons showed statistically significant decreases beyond the on-farm levels. Within the chiller tank in the processing plant, the persistence of these sequences appears to be related to the free chlorine concentration of the chiller tank water. The variable regions of the amplified integron sequences showed size diversity (ranging in size from 680-bp to 2,000-bp) indicating genetic diversity in the type of antibiotic resistance-coding gene cassettes on these genetic elements. The presence of the class 1 and class 2 integrons in the chlorinated chiller tank suggests that these sequences are capable of withstanding this critical step to reduce microbial loads on poultry carcasses. The persistence of the integron gene sequences on the farm and throughout the processing steps highlight the stability of antimicrobial resistance coding DNA sequences and the their potential role as reservoirs of antimicrobial resistance coding genetic elements within the poultry rearing and processing environments.