Consequences of using two types of skin samples from chilled chicken broiler carcasses to measure the degree of contamination by campylobacter spp.

Abstract

Because of concerns regarding the prevalence of Campylobacter in chicken meat, member countries in the European Union (EU) undertook a surveillance program to determine Campylobacter levels on chicken carcasses. A sample mass of 25 g principally composed of neck skin was used, although breast skin could also be used if there were insufficient neck skin to meet the required sample mass. The aim was to establish a baseline for Campylobacter contamination of carcasses against which future interventions could be assessed. However, in the United Kingdom researchers wanted to explore whether different ratios of neck to breast skin in samples could affect the results obtained. A comparison of the Campylobacter levels on neck and breast skin samples obtained from the same chilled chicken carcasses was undertaken at four chicken slaughterhouses. The neck skins were significantly more heavily contaminated (P < 0.05) with Campylobacter than was breast skin. Statistical analyses revealed no relationship that would allow a conversion between levels obtained on the two skin types. Ongoing surveillance of Campylobacter for 6 years was funded by United Kingdom poultry processors using samples consisting solely of neck skin, and the results of this surveillance (2011 to 2016) are reported here. Given the higher Campylobacter levels on a sample exclusively consisting of neck skin, this protocol could yield results with which the poultry industry would find it more difficult to achieve the contamination reduction target. The contamination reduction target for the United Kingdom (≤10% of chicken carcasses exceeding neck skin Campylobacter levels of 1,000 CFU/g) was not met by the end of 2015, the date stipulated by the United Kingdom government.