Genomic insights and survival dynamics of Campylobacter from ruminants in UHT milk, raw milk and dairy products - C. coli

Broiler meat is the primary foodborne source of campylobacteriosis, while milk is of particular relevance due to its association with outbreaks linked to raw milk consumption or inadequate pasteurization. In this study we investigated Campylobacter prevalence on carcasses and intestinal contents of cattle and sheep. Samples were collected at slaughterhouses and from farms and dairies, including raw milk and dairy products. Consequently, we generated Whole-genome sequencing (WGS) data to analyse the population structure, virulence, and antimicrobial resistance of 385 C. jejuni and C. coli isolates from cattle and sheep in Italy. The survival of C. jejuni strains was evaluated in milk and dairy products under different storage conditions using culture-based enumeration methods. Genome analysis revealed substantial genetic diversity, with distinct lineages associated with cattle and sheep. Furthermore, some isolates derived from food and animals exhibited elevated virulence potential, while antimicrobial resistance was generally limited. Particularly, C. jejuni demonstrated notable tolerance to refrigeration and dairy processing conditions, highlighting its ability to persist in dairy environments and its relevance for public health.