Ocorrência de genes de resistência a antibióticos em granjas avícolas localizadas no nordeste do Brasil

The misuse of antibiotics in food-producing animal farming practices exerts selectivepressure on bacterial strains, intensifying the spread of pathogenic and commensal bacteria carryingantibiotic resistance genes (ARGs). We conducted a study aiming to investigate ARGs in chicken litterfrom farms in the State of Sergipe, Northeast Brazil. A total of 14 chicken litter samples were collectedfrom twelve farms and subjected to total DNA extraction. The presence of ARGs in the obtainedmaterial was tested by Polymerase Chain Reaction (PCR) using primers for selected ARGs. ARGswere confirmed in all samples, and the highest resistance positivity was obtained for tetracyclines(tetA, tetM, and tetG), quinolones (gyrA and qnrS), beta-lactams (blaTEM), macrolides (ermB) andsulfonamides (sul-1). Sequencing and comparison with the GenBank database confirmed the identityof the ARGs. Some of the sequences that were amplified by PCR were similar to resistance factorsfound in Gram-positive and Gram-negative bacteria of different species, mostly enterobacteria.Furthermore, similarity was observed for resistance determinants located both on the chromosomeand on plasmids, transposons, and integrons. Our results indicate the potential of poultry farmingfor the environmental dissemination of ARGs in the State of Sergipe.