Prevalence and antimicrobial resistance profile in Salmonella spp. isolates from swine food chain

Abstract

The aim of this survey was to examine the prevalence and the antimicrobial resistance (AMR) of Salmonella spp. isolated from swine food chain. A total of 435 samples were collected: 360 from slaughterhouse (150 carcasses, 30 cecal samples, 180 environmental samples) and 75 from Italian traditional pork dry sausages. Thirty-six Salmonella were isolated and identified by Polymerase Chain Reaction (PCR): 13,3% (4/30) in fecal samples, 5,5% (10/180) in environmental samples, 7,3% (11/150) in carcasses, and 14,6% (11/75) in Italian traditional dry sausages. Salmonella serotypes were: S. Typhimurium (44,4%), S. Typhimurium monophasic variant (8,3%), S. Typhi (2,8%), S. Enteritidis (22,2%), S. Rissen (16,6%) and S. Derby (5,5%). Phenotypic and genotypic characterization of AMR Salmonella spp. isolates was exe-cuted through automatic system (VITEK 2, bioMèrieux) and PCR assays. Salmonella spp. showed phonotypical and genotypical resistance to at least one or more classes of antibiotic. All Salmonella spp. were resistant to aminoglycoside (amikacin and tobramycin) and gentamicin, 86,1% strains were resistant to tetracycline, 55,5% strains were resistant to ampicillin and piperacillin, 25% strains to trimethoprim, 5,5% strains to chloramphenicol, 2,8% strains to amoxi-cillin/clavulanic acid, and nitrofurantoin. Among Salmonella isolates, the most detected AMR genes were catA for chlo-ramphenicol (94,4%), nitrofuran nfsA (77.7%), nfsB (86,1%) and, for fluoro-quinolone par C (100%) and gyrA (94,4%). This study reported epidemiological data regarding Salmonella spp. and AMR’s cir-culation in the swine food chain. This phe-nomenon (AMR) has critical repercussions on the final consumer health; therefore, it represents a crucial One-Health issue.