Skin Bacteriome and its Resistance to Antibiotics in Free Range Pigs

Abstract

The cutaneous microbiome and also its resistance to antibiotics is exposed to change, depending on different habitat factors. This research investigates the composition of cutaneous microflora and its antibiotic resistance in pigs raised on free range farms (mix breed swine, from low input small farms). Swabs were collected from the skin surface and subjected to classical microbiological methods (simple broth and nutrient agar cultivation, colony isolation and biochemical API identification). The antibacterial resistance to gentamicin, streptomycin, oxitetracycline, tylosin, amoxacillin-clavulanic acid, marbofloxacin, tulatromycin, cefotaxime and doxycycline was estimated by Kirby Bauer method and multiple antibiotic resistance (MAR) index was calculated. Strains from Staphylococcus (sciuri and warnerii), Shigella spp., Kytococcus sedentarius, Salmonella spp. and Citrobacter freundii genera and species were identified in the collected samples. The most resistant was a S. warnerii strain, but the MAR index was high (0.33) in 50% of the strains. The most efficient antibiotic was cefotaxime and the least efficient was oxitetracycline. The results indicated the presence of antibiotic resistant ubiquitous and pathogenic strains in the investigated pigs which need caution, since they could express pathogenicity under appropriate conditions which low input farming system could provide.