Salmonella in pigs: impact on faecal microbiota related to the immune response

International audienceSalmonellosis remains the most frequent human food-borne zoonosis after campylobacteriosis and pork meat is considered as one of the major sources of human food-borne infections. At the farm, host heterogeneity in pig infection is problematic because high-shedders of Salmonella may contribute significantly to the spread of this foodborne pathogen in the food chain. The identification of biomarkers for high-shedders could help to control Salmonella in pigs. The purpose of the present study was to analyze immune-associated markers and composition of the faecal microbiota in pigs that shed differential amounts of Salmonella after oral infection with 109 CFU of Salmonella of 40 specific-pathogen-free (SPF) piglets. Blood and faecal samples were collected for three weeks post infection. Immune response was studied through total blood cell counts, production of anti-Salmonella antibody and TNF-, IL-1, IL-6 and IFN- cytokines using ElISA’s and gene expression. Salmonella enumeration during the 3 weeks allowed us to evaluate total Salmonella shedding for each pig, using the calculation of the area under the log curve (AULC) over 3 weeks. The hierarchical clustering of AULC value resulted in three classes, significantly different (p