Microbiological Safety and Quality of Meals and Work Surfaces in Collective Catering Systems in Central Italy: A Five-Year Monitoring Study.

Ready-to-eat (RTE) meals produced and served by the catering system still represent one of the major causes of foodborne outbreaks, especially for susceptible consumers. Despite the great progress in food hygiene and safety, the systematic monitoring of microbial contamination of foodstuff is the most effective tool to ensure food safety and protect consumers' health. The aim of this study was to perform a thorough assessment of the microbial safety and quality of meals and work surfaces of collective catering systems in central Italy, over a five-year period (2014−2018). In total 11,012 microbiological analytical determinations were performed in food matrices (80.1%) and environmental samples (19.9%). The results obtained show a low level of non-conformities ranging from 2.2% to 6.3% of total samples, concerning both hygiene and safety parameters. A decreasing trend of non-conformities during the years was also highlighted (p-value < 0.05), especially for environmental samples. This study suggests that the implementation of Good Manufacturing Practices (GMPs) and the proper definition of Hazard Analysis and Critical Control Point (HACCP) plans, combined with a thorough evaluation of microbiological monitoring, are able to ensure high levels of food safety and hygiene.

Prevalence, Molecular Characterization and Antimicrobial Susceptibility of Clostridioides difficile Isolated from Pig Carcasses and Pork Products in Central Italy.

In the last decade, the incidence and severity of Clostridioides difficile infections (CDIs) in humans have been increasing and community-associated infections have been described. For these reasons, the interest in C. difficile in food and in food animals has increased, suggesting other possible sources of C. difficile acquisition. This study evaluated the presence of C. difficile on pig carcasses at the slaughterhouse and in pork products in Central Italy. The contamination rate on pig carcasses was 4/179 (2.3%). Regarding food samples, a total of 216 pork products were tested (74 raw meat preparations and 142 ready-to-eat food samples made by cured raw meat). The real-time PCR screening was positive for 1/74 raw meat preparation (1.35%) and for 1/142 ready-to-eat food samples (0.7%) C. difficile was isolated only from the raw meat preparation (pork sausage). All the isolated strains were toxigenic and susceptible to all the tested antibiotics. Strains isolated from carcass samples displayed A+B+CDTa+CDTb+ profile, were toxinotype IV and belonged to the same ribotype arbitrary named TV93, while the one isolated from food samples displayed A+B+CDTa-CDTb- profile and it was not possible to determine ribotype and toxinotype, because it was lost after freeze storage. It was concluded that the prevalence of C. difficile in the pork supply chain is very low.

Thermal Inactivation and Growth Potential of Listeria Monocytogenes in Smoked Tench.

An experimental study for the evaluation of Listeria monocytogenes inactivation during a hot smoking process in tench was performed using Listeria innocua strains. Furthermore, the survival of L. monocytogenes in smoked tench was determined after post-processing in contaminated samples, evaluating the growth potential during storage. L innocua was not detected after the smoking process. In the challenge test, the growth potential of L. monocytogenes was 5.68 log colony forming unit g-1. The results showed that hot smoking at an inner temperature around 72°C is able to eliminate the microorganism. Nevertheless, the product is able to support the growth of the pathogen if post-process contamination occurs, as the food is suitable for Listeria multiplication. Product recontamination should be prevented by means of appropriate application of hygiene measures.