| Congresso Brasileiro de Microbiologia 2023 | Resumo: 743-1 | ||||
Resumo:Campylobacter spp. is a microorganism frequently present in poultry’s intestinal microbiota and the main cause of gastroenteritis in humans worldwide, being also associated with complications such as cases of Guillain-Barré syndrome. While the antimicrobial usage in animal husbandry has been responsible for numerous advantages in a production point of view, the levels of antimicrobial resistance are in constant raise and pose a threat to global health. Free-range and antibiotic-free poultry farming are tendencies that are increasingly relevant in animal husbandry, considering the expressive niche of consumers that show a concern over animal welfare and express a change in attitude towards factory farming. In this study, we assessed the antimicrobial resistance in Campylobacter spp. isolated from poultry from conventional production and from antibiotic-free farming, located in the states of Rio de Janeiro and São Paulo, respectively, in order to determine if the farming method may influence those strains’ resistance patterns. After isolating the strains from caecal content (n=15) and from the carcasses (n=9), the species were identified by multiplex PCR assay. Fourteen (14) C. coli and one (1) C. jejuni were identified from the caecal content of conventionally reared chickens, and all of the 9 strains from antibiotic-free farming were identified as C. jejuni. Isolates were screened for resistance to antibiotics by Disk Diffusion Method. Antimicrobial resistance to Amoxicillin with Clavulanic Acid, Ciprofloxacin, Chloramphenicol, Enrofloxacin, Erythromycin, Gentamicin, and Tetracycline observed in strains from poultry reared in the conventional system were respectively 13%, 87%, 6%, 87%, 0%, 0%, and 66%, while all the strains obtained from antibiotic-free poultry flocks were sensitive to all the antimicrobials tested. To investigate molecular mechanisms involved in tetracycline and fluoroquinolone resistance, we used PCR assay to detect the genes tetO and MAMA-PCR technique to detect Thr-86-Ile gyrA mutation. TetO and Thr-86-Ile gyrA mutation were detected in 100% and 93% of the strains from conventional production while none of the strains from antibiotic-free poultry had tetO or Thr-86-Ile gyrA mutation. It is possible to observe that strains obtained from antibiotic-free poultry flocks were not phenotypically and genotypically resistant to the antibiotics tested. This observation can help us understand the influence of different farming methods on the antimicrobial resistance problematic, and even assess their impacts in public health. Palavras-chave: antibiotic-free farming, antimicrobial resistance, campylobacter, conventional production, poultry Agência de fomento:Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Universidade Federal Fluminense (UFF) | |||||