Effect of immersion chiller management and microbial intervention strategy on Salmonella or Campylobacter post-chill carcass incidence during commercial turkey processing

Abstract

The first objective of this investigation was to identify a practical and efficient sampling and culture procedure for recovering Salmonella and Campylobacter from commercially processed turkey carcasses. To investigate this objective, several carcass rinsing and bacteriologic culture procedures were compared to identify a method for completing the second objective of the investigation, which was to conduct a microbiological survey of commercial turkey processing. During this large-scale survey of six independent turkey processing facilities, the effects of management practices and chosen microbial intervention strategies during immersion chilling on Salmonella or Campylobacter recovery were investigated. In two experiments, several carcass rinsing and culture procedures were compared to identify a method that was accurate, sensitive, inexpensive and logistically feasible for Salmonella recovery from processed turkey carcasses. Briefly, this method consists of rinsing carcasses in 200 mL of buffered peptone water (BPW) in a large polyethylene bag, aseptic collection of rinse fluid into sterile polypropylene culture bottles, pre-enrichment of recovered rinse fluid in additional BPW, selective enrichment in Rappaport-Vassiliadis broth (RV), and plating to double modified lysine iron agar (DMLIA) plates. Also, from the same sample of collected carcass rinse fluid, Campylobacter can be selectively cultured by direct enrichment in Bolton's complete enrichment medium followed by plating to Campy-cefex agar plating medium. This method of recovering Salmonella or Campylobacter was used to complete research directed at objective 2. Following a microbiological survey of commercial turkey processing, observed data led to the following conclusions. Our data indicate that most commercial turkey processing facilities apply effective management during immersion chilling to reduce the presence of foodborne pathogens on commercially processed turkeys. Importantly, assessment of chiller management within each plant was predictive of recorded microbiologic data. Obtained data indicated that facilities implementing the most stringent immersion chilling management practices were associated with the most effective Salmonella or Campylobacter remediation on processed carcasses. Further, if assessments of management reflected poor practices or oversight, microbiologic data were similarly reflective of such trends. Data from this investigation suggest that properly managed immersion chilling systems are capable of reducing the incidence of Salmonella or Campylobacter on post-chill processed poultry carcasses.