The occurrence of thermotolerant Campylobacter spp. in raw meat intended for public catering

The genus Campylobacter comprises Gram-negative spiral-shaped bacteria which can cause a foodborne illness in humans called campylobacteriosis; the infection generally occurs through the consumption of undercooked chicken or ready-to-eat meals that have been in contact with contamined raw chicken. The aim of the present study was to gain insight into the frequency of thermotolerant Campylobacter spp. contamination in 185 raw meat samples collected from 2006 to 2012 in different catering production plants in order to obtain data for subsequent use in risk-assessment. A three-way contingency table was statistically analyzed including the following three categorical variables: Year (Y), Meat Type (MT) and Campylobacter Presence (CP); statistical analysis was carried out using the Pearson’s Chi-squared test or the Fisher’s exact test. A highly significant Pearson’s Chi square value (0.005<p<0.01; 1df) was obtained highlighting that, averaged across the time period analyzed, poultry meat showed a significantly higher frequency (22.1%) than red meat (5.5%) of samples that were positive for the presence of thermotolerant Campylobacter spp. A highly significant variation across years was detected only for poultry meat (p=0.008), whereas the red meat category showed no significant variation (p=0.363). Within the poultry meat category a sequential approach was followed to investigate the significant variation in positive CP samples in the 2006-2012 time period analyzed. The years 2010 and 2011, were characterized by the lowest (7.4%) and the highest (50%) frequency of positive CP samples, respectively. On the whole, the variation across years in the frequency of positive CP samples must be attributed to two main causes: the difference in the overall frequency of positive and negative CP samples for poultry and red meat and the evident increase in positive counts in 2011 within the poultry meat type. In order to arrive at an accurate representation of the level of contamination of thermotolerant Campylobacter spp. in ready-to-eat foods, it would be appropriate to implement the national surveillance system to assess the risk for consumers.