Microbiological hazard analys of fermented foods

The International Scientific Association for Probiotics and Prebiotics (ISAPP) gives the definition of fermented foods and beverages as foods made through desired microbial growth and enzymatic conversions of food components (Marco et al., 2021 - Nature Reviews Gastroenterology & Hepatology 18:196–208). Even though fermented foods are unusually associated with microbiological hazards, some traditional fermented foods (e.g. raw milk based products and low-acid fermented foods) can pose a safety risk related to the contaminated raw materials or post-process contamination by Listeria, Salmonella, enterotoxigenic E. coli or other pathogens. In a scenario of market expansion of novel fermented foods from extra EU countries and the worrying reemerging of some food borne pathogens in the traditional fermented foods, the aim of this project is to conduct a hazard analysis by both culture dependent and metagenomic approach in some marketed fermented foods.

At least 100 different fermented food products from the market or directly from the producers will be collected in the area of center of Italy. Moreover, in cooperation with some factories, raw materials (e.g. milk and meat) and intermediates of the process will be collected. Environmental samples from the processing areas will be also collected (e.g. surfaces). All the samples will be collected according to the ISO procedures, to standardize the operations. Samples will be as rapidly as possible transported to the laboratory for the further manipulation. Within a culture dependent methodology, samples will be handled for the isolation of potential pathogenic microorganisms. Accordingly, a culturomic approach will be tented to maximize the isolation results. On the other side, a metagenomic approach will be implemented to reveal the presence of VBNC pathogenic strains. The DNA directly extracted from samples will be subjected to a V3/V4 PCR amplification and further pyrosequencing.

Results of the project will be the realization of a culture collection of food borne pathogenic microorganisms. Moreover, a data base on the pathogen contamination for the different fermented food categories will be the outcome for the follow robust risk analysis conduction.