Antibiotic resistance in Italian poultry meat production chain: a one-health perspective comparing antibiotic free and conventional systems from the farming to the slaughterhouse

In this study a multidisciplinary approach was applied in order to determine the diffusion of resistant bacteria and selected antibiotic resistance genes antibiotic-free conventional broiler farms. Litter samples coming from two farming types surface sponges obtained carcasses at slaughterhouse level were screened by end-point PCR targeting specific for tetracycline, ampicillin, sulfonamide, aminoglycoside, carbapenem, nitrofurantoin, vancomycin, quinupristin-dalfopristin, lincomycin, linezolid, chloramphenicol molecules. Microbiological investigations conducted phenotypical genetic patterns pathogenic commensal Gram-negative Gram-positive strains. At farm level, cat A1, sul 2, bla TEM aad A2 amplified all samples, while most representative , along with vat D, relative quinupristin-dalfopristin resistance. isolates included Aeromonas Salmonella Proteus spp. And Escherichia coli represented Enterococcus Phenotypical analysis revealed multidrug E. Serratia isolates, followed species. The comparison between systems showed some difference regarding distribution but no significance comparing profiles bacterial strains both groups suggesting poor influence model on poultry meat production chain.