Campylobacter survival potentially influenced by key microbial species within the microbiota on free-range broiler...

Campylobacter is the leading cause of foodborne gastroenteritis in Europe, with poultry as its primary reservoir. Although Campylobacter responses to abiotic stress are well documented, these mechanisms alone do not fully explain its persistence on broiler meat, suggesting a role for the surrounding meat microbiota. This study investigated whether Campylobacter survival during refrigerated storage of broiler meat was associated with specific microbial community structures. Using combined culture-dependent and culture-independent approaches, microbiota composition and Campylobacter levels were analyzed in 310 pooled rinsates from free-range broiler carcasses after chilling (D0) and 7 days of refrigerated storage (D7). Multivariate analysis and network-inference methods were applied to identify microbial taxa discriminating samples with the highest versus the lowest Campylobacter survival and to explore microbial co-occurrence patterns. Refrigerated storage reduced significantly Campylobacter levels from 1.28 to 0.78 log₁₀ CFU/ml and decreased overall species richness, while favoring psychrophilic aerobic bacteria associated with meat spoilage. After storage, samples exhibiting high and low Campylobacter survival were clearly separated based on distinct microbial community profiles characterized by 10 discriminant bacterial genera. Network analysis focusing on samples with the highest and lowest Campylobacter survival revealed a co-occurrence network in which Campylobacter was positively associated with 25 ASVs (ASV-level taxa) and negatively associated with 17 ASVs. Notably, positive correlations involved ASVs affiliated with Pseudomonas and Flavobacterium, whereas negative correlations included ASVs affiliated with Brochothrix and Myroides. These findings provide new insights into microbiota-Campylobacter associations on poultry carcasses and highlight perspectives for microbiota-targeted strategies to reduce Campylobacter contamination and improve poultry product safety.