Development of predictive models for the survival of Campylobacter jejuni (ATCC 43051) on cooked chicken breast patties and in broth as a function of temperature.

The objective of this study was to model the kinetics of the survival of Campylobacter jejuni on cooked chicken breast patties and in broth as a function of temperature. Both patties and broth were inoculated with 10(6) stationary-phase cells of a single strain of C. jejuni (ATCC 43051) and incubated at constant temperatures from 4 to 30 degrees C in 2 degrees C increments under aerobic conditions. In most cases, a three-phase linear model fit the primary survival curves well (r2 = 0.97 to 0.99) at all incubation temperatures regardless of model medium, indicating the presence of a resistant subpopulation of C. jejuni that would not be eliminated without thermal processing. Secondary models predicting lag time (LT) and specific death rate (SDR) as functions of temperature were also developed. The Davey and Boltzmann models were identified as appropriate secondary models for LT and SDR, respectively, on the basis of goodness of fit (Boltzmann model, r2 = 0.96; Davey model, r2 = 0.93) and prediction bias and accuracy factor tests. The results obtained indicate that C. jejuni can survive well at both refrigeration and ambient temperatures regardless of model medium. Reduced survival of C. jejuni, characterized by shorter lag times and faster death rates, was observed both on patties and in broth at ambient temperatures. In addition, the average maximum reduction of C. jejuni at 4 to 30 degrees C was 1.5 log units regardless of storage temperature or model medium. These findings suggest that C. jejuni found on contaminated poultry products has the potential to survive under conditions that are not permissive for growth and thus could cause foodborne illness if the poultry is not sufficiently cooked.