Evaluating Post-evisceration Processing Steps and In-plant Antimicrobial Treatments against Campylobacter, Escherichia coli, and Aerobic Bacteria on Poultry Carcasses

Introduction: Campylobacter is a pathogenic bacterium commonly found in the intestinal tract of poultry, and widely associated with poultry-borne human illnesses. Interventions such as chlorine and peracetic acid are commonly used to control this pathogen from poultry products, reducing the risk of poultry-related illness. These antimicrobials also assist in enhancing the shelf life of poultry products by reducing the bacterial load on carcasses. 

Purpose: The purpose of this study was to evaluate the effectiveness of processing steps and different antimicrobial treatments in poultry processing plants; focusing on pathogen elimination and non-pathogenic microbial load reduction.

Methods: Post-evisceration whole bird rinse samples were taken off the processing line before entering the inside-outside bird washer (IOBW), post-IOBW treatment, after pre-chilling, after main chiller treatment, and after post-chiller treatment from five processing plants. Rinse samples were then plated on campy-cefex agar, violet red bile agar, and plate count agar to determine the level (log CFU/ml) or prevalence of Campylobacter, Escherichia coli, and aerobic plate counts (APC), respectively. Average log CFU/ml bacterial growth was recorded for each sampling point and compared to determine the effectiveness of antimicrobial treatments. 

Results: Carcasses treated with chlorine-based antimicrobials including sodium hypochlorite showed significant (P < 0.05) reductions in Campylobacter and APC after the IOBW, while a significant (P < 0.05) reduction in E. coli was observed after exiting the pre-chiller; however, peracetic acid treatment resulted only in the significant (P < 0.05) reduction of Campylobacter after the IOBW, while significant (P < 0.05) reductions in E. coli and APC were observed after exiting the pre-chiller. 

Significance: Results suggest that chlorine-based antimicrobials and peracetic acid are all effective in inhibiting foodborne pathogens such as Campylobacter, E. coli, and APC on poultry carcasses. However, exposure times and the point of application of antimicrobials may be critical in significantly reducing/eliminating bacteria from poultry carcasses.