Detection of enterotoxigenic genes and mecA gene in Staphylococcus aureus isolated from goat milk / Detecção de genes enterotoxigêncos e do gene mecA em Staphylococcus aureus isolados de leite caprino

Germana Guimarães Rebouças, Maria Rociene Abrantes, Manoela de Oliveira Rebouças, Bruno Vinicios Silva de Araújo, Sidnei Miyoshi Sakamoto, Jean Berg Alves da Silva


Staphylococcus aureus is a concern to food producers, because it is responsible for causing a variety of illnesses in people, among which are the toxin-mediated diseases, and because there is an increasing resistance of S. aureus to antibiotics. Thus, we aimed to detect the presence of enterotoxigenic genes and the mecA gene in S. aureus isolated from goat milk. We collected 49 samples of goat milk in which we performed a S. aureus search and resistance profile analysis by the diffusion in disks technique in Mueller-Hinton Agar using disks impregnated with the following antibiotics: sulfamethoxazole-trimethoprim (25μg), vancomycin (30μg), tetracycline (30μg), gentamicin (10μg), oxacillin (1μg), ciprofloxacin (5μg), erythromycin (15μg) and penicillin G (10μg). Next, we searched the genes of interest to the study using the Polymerase Chain Reaction (PCR). Results from the phenotypic evaluation of the resistance profile of S. aureus showed increased resistance to the antibiotics penicillin G (87.75%) and oxacillin (75.51%). S. aureus was molecularly identified by the 16S rRNA gene, with amplification in 100% of the strains isolated. We also verified the percentage of amplification for the sea, sec, sed, seg, seh, sei, sej and mecA genes. The highest percentage of amplification was of the sej gene (79.5%), followed by sei gene (48.9%). The mecA gene was detected in 4.08% of the samples. These results suggest that it is of fundamental importance to analyze the staphylococcal enterotoxins on goat milk, to protect consumers from food poisoning and to ensure public health.




Food poisoning; Molecular biology; Resistance; PCR.

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