| Congresso Brasileiro de Microbiologia 2023 | Resumo: 281-2 | ||||
Resumo:The objective of this study was to assess antimicrobial resistance (AMR) and evaluate the genetic profile of resistance and virulence in Escherichia coli isolates obtained from a swine production chain. A total of 622 swine carcass samples were collected from various points in the slaughter process, including processing points (n=400), swine feces (n=100), commercial cuts (n=45), environment (n=67), and employee feces (n=10), from a pork slaughterhouse in São Paulo, Brazil. Out of the collected samples, 73.6% tested positive for E. coli, resulting in the isolation of 1260 E. coli strains. All strains were subjected to the disk diffusion test using 12 antimicrobials from 10 different pharmacological classes. The tested antimicrobials included amoxicillin, ceftiofur, ceftazidime, cefotaxime, imipenem, aztreonam, gentamicin, tetracycline, ciprofloxacin, sulfamethoxazole with trimethoprim, chloramphenicol, and azithromycin. From each sample, one multi-drug resistant (MDR) strain (n=160) and one strain sensitive to all tested antimicrobials (n=64) were selected for further analysis. These selected strains underwent Polymerase Chain Reaction (PCR) to assess the presence of virulence genes Stx1 and Stx2, as well as the gene associated with multidrug resistance, Integron class I (Int1). The results showed a high frequency of resistance to five classes of antimicrobials, including amoxicillin, gentamicin, tetracycline, sulfamethoxazole with trimethoprim, and chloramphenicol. Among all strains, 80.71% were identified as multidrug-resistant (MDR). While 14% (9/64) of the susceptible strains expressed the Int1 gene, 41% (65/160) of the resistant strains exhibited this gene. None of the strains tested positive for the Stx1 and Stx2 virulence genes. Isolates from human feces samples had a lower likelihood of being MDR compared to samples from other sources. The samples exhibited a diversity of resistance profiles, with no distinct clustering based on the sources, except for isolates from human feces, which showed a lower variability of antimicrobial resistance (AMR). The study findings emphasize the significant presence of AMR in the pork production chain. The expression of genes conferring resistance to multiple drugs, which are used in both human and animal medicine, highlights the need for a multidisciplinary approach to control and reduce risks in the context of One Health. Palavras-chave: AMR, antibiotics, enterobacteria, One Health | |||||