Exploring Gut Microbiota Composition and Occurrence of Selected Antimicrobial Resistance Genes in Domestic Pigs and Urban and Sylvatic Wild Boars from Sicily

Abstract

Simple Summary The gut microbiota is a complex community of microorganisms that plays an important role in digestion, immune function, and health host. At the same time, antimicrobial resistance represents a major One Health concern because resistant bacteria and resistance genes can circulate among humans, animals, and the environment. Wild boars and domestic pigs belong to the same species (Sus scrofa) and may occur in different environmental and management settings. The main objective of this exploratory study was to compare the gut microbiota and the occurrence of selected antimicrobial resistance genes among domestic pigs, urban wild boars, and sylvatic wild boars. These animals represented three geographically and ecologically distinct Sicilian populations. Ileal samples collected from wild boars and domestic pigs were analyzed by sequencing the V3–V4 region of the bacterial 16S rRNA gene. In parallel, selected genes associated with β-lactam and tetracycline resistance were investigated. The study was designed to describe differences among the three sampled populations, rather than to determine the independent or causal effects of domestication, habitat, or anthropogenic exposure. The findings provide baseline information on gut microbial communities and selected antimicrobial resistance genes at the wildlife–livestock–human interface and may inform future surveillance studies.