Proposal of sampling protocols to verify possible performance objectives for Campylobacter species control in Italian broiler batches

Abstract

Campylobacteriosis represents the most important food-borne illness in the EU. Broilers, as well as poultry meat, spread the majority of strains responsible for human cases. The main aims of this study were to suggest an approach for the definition of performance objectives (POs) based on prevalence and concentration of Campylobacter species (spp.) in broiler carcasses; moreover, sampling plans to determine the acceptability of broiler batches at the slaughterhouses in relation to such POs were formulated. The dataset used in this study was the one regarding Italy composed during the European Food Safety Authority baseline survey which was performed in the EU in 2008. A total of 393 carcasses obtained from 393 different batches collected from 48 Italian slaughterhouses were included in the analysis. Uncertainty in prevalence and concentration of Campylobacter spp. on carcasses was quantified assuming a beta and log normal distribution. Statistical analysis and distribution fitting were performed in ModelRisk v4.3 (Monte Carlo simulation with 10,000 iterations). By taking the 50th percentile of prevalence distribution as safety limit, sampling plans were subsequently calculated basing on the binomial approach. Final values of number of samples were equal to 4 or 5 to test with qualitative analysis. Considering a limit of quantification of 10 colony forming units/g, a higher number of samples (i.e. 10-13) would be necessary to test using enumeration. An increase of the sensibility of the analytical technique should be necessary to achieve realistic and useful sampling plans based on concentration data.