| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1147-2 | ||||
Resumo:Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen of healthcare-associated infections. It carries the mecA gene which confers resistance to all beta-lactam agents, except 5th generation cephalosporins. However, there are some reports about strains that possess mecA but are phenotypically susceptible (OS-MRSA; oxacillin-susceptible mecA-positive MRSA). So, routine methods to determinate antimicrobial resistance do not detect these strains. In a previous study, two OS-MRSA strains were recovered from one pig and one employee of a farm in the Rio de Janeiro state in 2019. Therefore, the present study aimed to characterize these two strains. The phenotypic resistance profile was determined by disk diffusion method for following antimicrobial agents: cefoxitin, chloramphenicol, ciprofloxacin, clindamycin, erythromycin, gentamicin, linezolid, penicillin, rifampicin, tetracycline, and trimethoprim-sulfamethoxazole. D-zone test and cefoxitin disk were performed to detect inducible clindamycin resistance and methicillin resistance, respectively. By whole genome sequencing, SCCmec type¸ spa type, sequence type, resistance and virulence profiles were identified. The tools SCCmecFinder, spaTyper, MLST, ResFinder, MobileElementFinder and VirulenceFinder (https://www.genomicepidemiology.org/services/) were used in the analysis. Both strains presented the same molecular and phenotypic characteristics. They were resistant to ciprofloxacin, clindamycin, chloramphenicol, erythromycin, penicillin, and tetracycline. They were identified as LA-MRSA ST398-SCCmec type V (5C2&5)-t011. The resistance genes detected were blaZ, dfrG, erm(C), fexA, grlA, lsa(E), mecA, tet(K) and tet(M) and the virulence genes aur, hlgA, hlgB and hlgC. OS-MRSA are found in both animals and humans with potential interspecies transmission. The spread of them is worrisome due to misidentification as MSSA (methicillin-susceptible Staphylococcus aureus). Palavras-chave: Staphylococcus aureus, OS-MRSA, pig, farm worker Agência de fomento:FAPERJ, CAPES | |||||