| Congresso Brasileiro de Microbiologia 2023 | Resumo: 564-2 | ||||
Resumo:Antimicrobial resistance is a paramount worldwide public health concern, with increasing demand for antibiotics leading to higher selective pressure levels, inducing a higher occurrence of Antimicrobial Resistance Genes (AMR) and mutations. Poultry, as reservoirs for various Salmonella strains, poses a significant concern for public health due to the potential of products contamination. The presence of antimicrobial resistance in Salmonella spp. found in poultry is a pressing issue that can have implications for both animal and human health. The objective of this study was to characterize the antibiotic profile of Salmonella spp. strains isolated from chicken retail cuts in both conventional and antibiotic-free production systems. The aim was to compare the isolates and evaluate whether those from the antibiotic-free chain exhibit less resistance than those from the conventional chain.
A total of 284 retail cuts purchased from supermarkets in Botucatu (São Paulo State, Brazil) were examined, with 143 from the conventional chain and 141 from the antibiotic-free chain. Salmonella detection was performed on all samples, resulting in 31 positive samples (10.8%). Out of these, 26 were from the conventional chain and 5 from the antibiotic-free chain (p<0.05). The obtained isolates underwent 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 determine any association between production systems and MDR.
Out of the 195 Salmonella spp. isolates obtained from chicken samples, 177 were from the conventional chain, and 18 were from the antibiotic-free chain. The prevalence of Salmonella spp. was higher in isolates from the conventional chain. Regarding the antibiotic profile, the isolates from the conventional chain exhibited 41 different profile combinations, with the most frequent combination being Amoxicillin clavulanate+Ceftazidime+Cefoxitin+Trimethoprim-Sulfamethoxazole+Ampicillin+Tetracycline. Interestingly, despite the antibiotic-free chain showing a lower prevalence for Salmonella spp., the most observed antibiotic resistance profile in these samples was the same as that from the conventional chain, with an overall of 9 combinations. Finally, considering all 195 isolates, 177 (90.7%) were MDR, with 159 (89.8%) from the conventional chain and 18 (100%) from the antibiotic-free chain (p>0.05).
Given that Salmonella spp. is a pathogenic bacterium, and salmonellosis is the most common foodborne disease in humans worldwide, a high prevalence of MDR strains could not only increase the burden of this disease but also facilitate the spread of resistant genes to other bacteria. Our results suggest that an antibiotic-free production system might not be sufficient to prevent MDR Salmonella spp. from poultry. Furthermore, these findings indicate that antibiotic resistance in animal products should be studied considering the whole production system, as the type of production may not significantly influence the prevalence of resistant Salmonella spp. strains. Palavras-chave: antibiotic-free poultry, Bacterial resistance, Salmonella 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) | |||||