Microbial community dynamics of wild boar carcasses and meat-contact surfaces, and their hygiene implications

Wild boar (Sus scrofa) meat is increasingly valued as a traditional and sustainable food resource. However, unlike conventional livestock, it is harvested and processed under variable field conditions that may influence its microbiological quality and safety. This study assessed the composition and dynamics of the culturable microbial population on wild boar skin surfaces, and processing equipment, aiming to identify potential food safety risks and contamination routes along the processing chain. Bacteria were isolated on plate count agar, from wild boar skin swabs, knives, tables and cooling units in registered and private wild boar processing establishments in Campania and identified by MALDI-TOF MS and sequencing of the 16S rRNA gene. Overall, the identified organisms belonged to 66 different genera, dominated by Escherichia, Staphylococcus, Pseudomonas and Macrococcus. The alpha diversity analysis revealed similar richness and evenness of culturable microbial communities across all groups (Kruskal-Wallis test p > 0.05). PERMANOVA based on Bray-Curtis dissimilarity however showed that microbial community composition was significantly influenced by localised facility interactions (Location ∗ Establishment; F = 2.98-3.47, R² = 0.035-0.044, P = 0.001), whereas sample source (F = 0.95-1.04, R² = 0.011-0.013, p > 0.05) and anatomical sites (F = 0.9681, R² = 0.02289, p = 0.524) had no significant impact. Microbial overlap analysis showed source restriction, with many genera detected in only one sample type, and only limited sharing across sample matrices, with the dominant sharing pattern observed between skin swabs and knives, and skin swabs and tables. Jaccard similarity indices ranged between 0.043 and 0.351 across the processing facilities. The findings of this study reveal that while the carcasses act as the primary sources of microbial introduction, environmental surfaces and cooling systems facilitate the persistence and redistribution of key taxa. These findings highlight the importance of comprehensive, system-wide interventions to effectively control microbial contamination and ensure the safety and quality of wild boar meat.