| Congresso Brasileiro de Microbiologia 2023 | Resumo: 879-1 | ||||
Resumo:Staphylococcus spp. has been considered one of the main bacterial involved in bovine mastitis. Staphylococcus aureus has also stood out for its importance in public and animal health. Currently, in the context of One Health, there is great concern regarding antimicrobial resistance in microorganisms isolated from food-producing animals, such as dairy cattle. This interest is due to the possibility of multidrug resistant (MDR) microorganisms migrating from animals, mainly through food, to the human population. In our study, were evaluated three dairy herds in the state of Rio de Janeiro, two in areas of dairy production of the South region and one in the metropolitan region, regarding the presence of mastitis, from January to May 2022 (herd A and B) and from January to June 2023 (herd C). For that, the animals were evaluated with the California Mastitis Test and clinical evaluation, and the milk from the mammary quarters that presented mastitis were collected and analyzed in the laboratory for bacterial isolation and identification in the MALDI-TOF. From 80 milk samples collected, 160 bacterial strains were isolated. The Staphylococcus spp. (n=58, 36.25%) was the most common bacterial genus, with S. aureus (n=48, 30%) being the most prevalent species. Microorganisms from the Enterobacteriaceae family (n=32, 20%) and other less relevant bacteria (n=22, 13.75%) were also identified. Staphylococcus spp. and S. aureus were the main ones involved in mastitis and were evaluated the resistance to antimicrobials by disc diffusion, of these bacteria and were detected the presence of MDR (n=28, 43%) and the presence of MRSA (Methicillin Resistant Staphylococcus aureus), n=9, 13.84%, of the isolated S. aureus. Were evaluated 65 strains for 12 classes of antimicrobials and the most resistant profile showed resistance to 66.67% of the antimicrobials, in one MDR strain. Among the MDR strains, with resistance to 58.33% of antimicrobials, one MDR strain and two MDR/MRSA strains; 2 MDR strains and one MDR/MRSA, which showed resistance to 50% of the antimicrobial, and two S. aureus MDR/MRSA strains and one Staphylococcus spp. MDR showed resistance to 41,67%. The occurrence of intermediate resistance to chloramphenicol and resistance to nitrofurantoin which were banned in the veterinary field, as a food additive and clinical use since 2003, is stands out. Resistance to penicillin reached 68%, while erythromycin 28.3%, and clindamycin 25%. This study contributes to the knowledge of the situation found in dairy herds, offering the opportunity to expand studies of antimicrobial resistance in bacteria from raw milk in the state of Rio de Janeiro, and allows questions about the treatments generally used for the prevention and control of bovine mastitis in Brazil.
Keywords: MALDI-TOF, Staphylococcus aureus, Multidrug Resistant (MDR), Methicillin Resistant Staphylococcus aureus (MRSA), One Health
Development Agency: Secretary of Agriculture, Livestock, Fishing and Supply of the State of Rio de Janeiro, Carlos Chagas Foundation for Research Support of the State of Rio de Janeiro (FAPERJ) Palavras-chave: MALDI-TOF, Staphylococcus aureus, Multidrug Resistant (MDR), Methicillin Resistant S.aureus (MRSA), One Health Agęncia de fomento:Secretary of Agriculture, Livestock, Fishing and Supply of the State of Rio de Janeiro, Carlos Chagas Foundation for Research Support of the State of Rio de Janeiro (FAPERJ) | |||||