Isolation of Staphylococcus from minas frescal type cheese and detection of enterotoxin genes

ABSTRACT

This work aimed at isolating Staphylococcus spp. from minas frescal type cheese, and for this purpose a Multiplex PCR (M-PCR) was standardized for detecting the classical Staphylococcus aureus enterotoxingenes (sea, seb, sec, sed and see), using the femA gene as a positive control for S. aureus strains. Bacterial detection directly from the minas frescal type cheese and from artificially contaminated food was tested.One hundred eleven colonies (104 coagulase-positive and seven coagulase-negative) were selected for performing M-PCR assay. Thirty-four colonies (30.62%) were positive for at least one of the fiveente rotoxin genes analyzed; enterotoxins sea and seb were the most frequently detected. The study on Staphylococci coagulase-positive samples revealed that 40% of the samples showed bacterial counts above the limit established by Brazilian legislation. (AU)