Perfil de resistência aos antimicrobianos e presença do gene mecA em cocos Gram-positivos catalase positivos isolados de queijos artesanais e ingredientes utilizados na sua produção

Abstract

The consumption of artisanal cheeses produced with raw milk is growing in Brazil, and new producing regions have been establishing themselves and gaining prominence. The production and consumption of these cheeses represent a source of dissemination of antimicrobial-resistant bacteria and of resistance genes. The aim of this study was to evaluate the resistance profile of species belonging to the genus Staphylococcus isolated from raw milk, whey, brine and artisanal cheeses produced in two municipalities in the south/southeast region of the State of Minas Gerais. Isolation of the microorganisms was made from Baird-Parker agar during the enumeration of coagulase-positive staphylococci from food samples. Bacterial identification was performed using MALDI-TOF mass spectrometry and the resistance profile was determined using the agar diffusion technique. The search for the mecA gene was performed using PCR. Eighty-two catalase-positive Gram-positive cocci belonging to the genera Staphylococcus (n=75), Kocuria (n=3) and Macrococcus (n=4) were identified. Of these samples, 79.3% showed resistance to at least one antimicrobial and 17.1% showed multidrug resistance (resistance to three or more classes of antimicrobials). The antimicrobial with the highest percentage of resistance was penicillin (67.1%), followed by tetracycline (42.7%) and sulfonamides (26.8%). The mecA gene was detected in three isolates, one S. aureus, one S. epidermidis and one S. haemolyticus. The occurrence of multiresistant Staphylococcus strains and the presence of mecA gene in three of these strains underscore the importance of monitoring the microbiological quality of raw milk and artisanal cheeses produced in Minas Gerais.