Purpose: To use enrichment real time-polymerase chain reaction (RT-PCR) to enumerate Salmonella that contaminate raw chicken parts at retail or that cross-contaminate cooked chicken during simulated meal preparation and serving.
Methods: Whole raw chickens obtained at retail were partitioned into wings, breasts, thighs, and drumsticks using a sterilized knife and cutting board. To study cross-contamination, the knife, board, and latex gloves used to partition the raw chicken were used to partition a cooked chicken breast. Chicken parts were incubated in 400 ml of buffered peptone water for 8h at 40°C and 80 rpm. After enrichment, one ml samples were used for RT-PCR and cultural isolation of Salmonella. In some experiments, chicken parts were spiked with 0 to 3.6 log of Salmonella Typhimurium var 5- to generate standard curves for enumeration by RT-PCR.
Results: Of 10 raw chickens examined, seven (70%) had one or more parts contaminated with Salmonella. Of 80 raw parts examined, 15 (19%) were contaminated with Salmonella. Of 20 cooked chicken parts examined, two (10%) were contaminated with Salmonella. Predominant serotypes identified were Typhimurium (71%) and its variants (var 5-, monophasic, and nonmotile) and Kentucky (18%). The number of Salmonella on contaminated parts ranged from one to two per part.
Significance: Results of this study indicated that retail chicken parts examined were contaminated with low levels of Salmonella and resulted in low levels of cross-contamination during simulated meal preparation and serving. Thus, as long as consumers properly handle and prepare this chicken it should pose no or very low risk of consumer exposure to Salmonella.