| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1103-1 | ||||
Resumo:Food is the main link between animal, human and environmental health, which are the axes of one-health. The health of the dairy herd is mainly affected by subclinical mastitis (SCM), whose milk is sent to the dairy chain and used in the production of cheeses. The antimicrobials most used in agriculture and human medicine are β-lactams, being adopted as the first choice or even as one of the last resources. Extended-spectrum β-lactamase-producing (ESBL) and Enterobacteriaceae resistant to carbapenems (CRE) and methicillin-resistant Staphylococcus aureus (MRSA) are among the priority agents for the development of new antimicrobials. Resistance mechanisms can be disseminated through horizontal gene transference. In addition, pathogenic strains of Shiga-toxin-producing Escherichia coli (STEC) have cattle as their main reservoir and can contaminate milk due to hygienic failures in milking and contaminate cheese. Infections caused by STEC can progress to hemolytic uremic syndrome (HUS) and be potentially life threatening. This study aimed to evaluate ESBL, CRE and MRSA phenotypes in freshly milked milk with positive for SCM (SCMM), diagnosed using the California Mastitis Test (CMT), bulk tank milk (BTM) and fresh cheeses and to search for STEC marker genes in BTM and cheeses samples. From January to October, 2022, 65 SCMM, 7 BTM and 8 cheese samples, from three dairy farms, were evaluated. A total of 285 strains (SCMM=60; BTM=104; cheeses=121) identified by MALDI-TOF as Enterobacteriaceae or Staphylococcus spp. were investigated for antimicrobial resistance by disk diffusion. The BTM and cheese samples were evaluated for the presence of stx1 and stx2 genes by polymerase chain reaction (PCR). ESBL were observed in 1.47% and 3.33% and CRE in 13.24% and 17.78% of Enterobacteriaceae isolated from BTM and cheese samples, respectively; and were not observed in SCMM strains. Furthermore, 25%, 38.89% and 30% of Staphylococcus aureus isolated from SCMM, BTM and cheese, respectively, were MRSA. stx1 was amplified in 12,5% of cheese samples and stx2 in 14,29% of BTM samples. stx1 and stx2 were not amplified in BTM and cheese samples, respectively. None of BTM and cheese samples carried both stx1/stx2. It is concluded that SCMM, BTM and fresh cheese samples are vehicles of dissemination of critical phenotypes of resistance, that may disseminate its resistance genes to human microbiota. And are also vehicle of STEC, that may cause human life-threatening infections. Palavras-chave: antimicrobial resistance, carbapenem resistant-Enterobacteriaceae, ESBL, MRSA, shiga toxin-producing Escherichia coli Agência de fomento:FAPERJ e Secretaria de Agricultura, Pesca e Abastecimento do estado do Rio de Janeiro. | |||||