| Congresso Brasileiro de Microbiologia 2023 | Resumo: 564-1 | ||||
Resumo:Antimicrobial resistance is a major public health issue worldwide, as the emergence of resistant bacterial strains often outpaces the development of new antibiotics. The use of antimicrobial agents in poultry production can contribute to the development and spread of antimicrobial resistance in Enterococcus spp. The selective pressure exerted by antibiotics promotes the survival and proliferation of resistant strains within poultry flocks. Given that Enterococcus spp. can transmit resistant strains from poultry to humans through the food chain, antimicrobial resistance in these bacteria poses a significant concern in the poultry industry. The aim of this study was to evaluate the antibiotic resistance profile of Enterococcus spp. isolated from poultry retail cuts and compare both conventional and antibiotic-free production systems to determine if the antibiotic-free system has fewer resistant strains than the conventional chain.
A total of 164 chicken retail cuts purchased from supermarkets in Botucatu (São Paulo State, Brazil) were examined, with 83 from the conventional chain and 81 from the antibiotic-free chain. The obtained isolates were then subjected to disc-diffusion tests to evaluate their antibiotic profile against different classes, following CLSI (2022) guidelines. Isolates resistant to three or more antibiotic classes were considered Multidrug Resistant (MDR). The results were analyzed using frequency presentations, and a Chi-square test was conducted to assess any association between production systems and MDR. All collected samples underwent Enterococcus spp. detection, and 159 (96.9%) samples tested positive, with 79 (49.7%) from the conventional chain and 80 (50.3%) from antibiotic-free chicken (p>0.05). In total, 449 Enterococcus spp. isolates were obtained, with 299 undergoing disc-diffusion testing. Concerning the antibiotic profile, isolates from the conventional chain exhibited 25 different antibiotic combinations, while those from the antibiotic-free chain had 22 distinct profiles. However, the most frequent profile in both chains did not differ significantly, with Tetracycline, Tetracycline+Ciprofloxacin, and Vancomycin being the most common ones. Out of all isolates tested, 36 (12.0%) were identified as MDR, with 24 originating from the conventional chain and 12 from the antibiotic-free chain (p>0.05).
Considering that Enterococcus spp. is a commensal bacterium capable of causing lethal infections in humans, such as endocarditis and bacteremia, and is associated with healthcare-associated infections, particularly in hospitals and long-term care facilities, it is crucial to monitor its resistance and the role it plays in maintaining resistant genes and strains. The results of our study suggest not only that an antibiotic-free production system might not entirely prevent MDR Enterococcus spp. in chicken but also that antibiotic resistance studies should consider the whole production system, as the type of production may not significantly influence the prevalence of resistant Enterococcus spp. strains. Palavras-chave: antibiotic-free poultry, Bacterial resistance, Enterococcus spp. Agência de fomento:Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) e Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) | |||||