Identificação genotípica de staphylococcus aureus multiresistentes a drogas isolados de animais de produção

Abstract

Identification of microorganisms at the species level is ensured by genotypic methods analyses. The femA gene (Factor Essential for Methicillin resistance) has been used as marker specie specific of Sta-phylococcus aureus, independently if it is methicillin-resistant or not. This study aimed to verify the use of femA gene as a tool for confirmation of the Staphylococcus aureus species in production animals. Samples harvested from the ceiling surface e of cattle’s milk were used for isolation, selection and identification of microorganisms by microbiological standard methods. All isolates previously identified as S. aureus and resistant to oxacillin were submitted to genomic DNA extraction according to the KAPA Ex-tract kit manufacturer’s recommendations. The DNAs were quantified and then submitted to Polimerase Chain reaction (PCR) to detection of the femA gene. The amplicons were visualized on 1.5% agarose gel and photodocumented. All isolates presumptively identified by microbiological standard methods (14/14) and S. aureus strain ATCC 25923 (positive control) amplified a fragment of 132 base pairs cor-responding to the partial femA gene. The presence of the femA gene in all isolates by molecular analysis confirmed the microbiological method presumptive identification as S. aureus.