Detecção de genes que codificam para enterotoxinas produzidas por Staphylococcus aureus isolados de leite de tanques de expansão comunitários em Alagoas

Abstract

The contamination of fresh milk by Staphylococcus aureus is a public health preoccupation due to their potential to produce enterotoxin and virulence factors. The objective of this study was to detect genes encoding for enterotoxins produced by Staphylococcus aureus isolates from raw milk from expansion of community in the State of Alagoas tanks. The strains were provided by the laboratory of Milk and Dairy Products Inspection, Federal University of Alagoas. The 39 samples were previously subjected to biochemical tests among them the coagulase test and subsequently identified and stored at -20ºC. Were reactivated and subjected to polymerase chain reaction (PCR) using specific primers. Among the 39 strains of coagulase positive Staphylococcus undergoing research Nuc gene, 69.2% (27/39) were identified as Staphylococcus aureus by PCR technique. Of the 27 samples of Staphylococcus aureus enterotoxin underwent investigation of classical (Seb), (Sec) and (See) and new toxins (Seh) and (Sei), 18.51% (5/27) were positive for enterotoxin gene, and fragments of genes involved in the synthesis classical enterotoxins Seb, Sec and See and the new toxins Sei were not amplified in any of the isolates, only fragments of the gene involved in the synthesis Seh was amplified. Fragments of the genes involved in the synthesis of α-hemolysin amplify 81.5% (22/27). And for β-hemolysin amplified 51.8% (14/27). This study concluded that the high percentage of Staphylococcus aureus with the presence of gene capable to produce staphylococcal enterotoxins found in raw Milk is a indicative of risks to public health due to their potential to produce thermostable enterotoxin that are not eliminated during the industrial thermal process and could food poisoning. Staphylococcus aureus with the presence of gene capable of producing staphylococcal enterotoxins in raw milk, indicating a high probability of producing the same.