Comparative analysis of the microbiome composition of artisanal cheeses produced in the Mediterranean area

In the PRIMA project ArtiSaneFood, the microbiological parameters of several artisanal cheeses produced in the Mediterranean area have been quantified. In this pilot study, we selected four of these artisanal cheese products from Italy, Portugal, Spain, and Morocco to investigate and compare their microbiomes in terms of taxonomic composition, presence of reads of foodborne pathogens, as well as virulence and antimicrobial resistance genes. Lactococcus, Streptococcus and Lactobacillus were the most represented genera in the Portuguese and Spanish cheeses, Streptococcus in the Italian cheese, and Enterococcus, Klebsiella, Escherichia, and Citrobacter in the Moroccan products. The correlation analysis indicated a negative association between the abundance of some lactic acid bacteria (i.e., Lactococcus, Lactobacillus, Streptococcus, and Leuconostoc) and foodborne pathogenic genera, like Escherichia and Salmonella. The analysis of pathogen abundance, virulence factors, and antimicrobial resistance genes showed a strong clusterization based on the cheese type, confirming that the presence of potential human health risk determinants was higher in the artisanal products derived from unpasteurized milk that underwent spontaneous fermentation.