Genes para enterotoxinas em Staphylococcus sp. isolados de manipuladores de alimentos de um restaurante universitário na cidade do Natal-RN

Abstract

Food handlers carrying enterotoxin-producing Staphylococcus are a potential source of food contamination. The aim of this study was to analyze genes enconding enterotoxins in coagulase-positive Staphylococcus (CoPS) and coagulase-negative Staphylococcus (CoNS) isolated from the anterior nostrils and hands of food handlers at a university restaurant in the city of Natal, Northeast Brazil. Thirty food handlers were screened for the study and the collected Staphylococcus sp. Most isolates were subjected to Gram staining, a bacitracin sensitivity test, mannitol fermentation, and catalase and coagulase tests. CoNS and CoPS strains were subsequently identified by biochemical tests and a Vitek 2 System (BioMerieux, France). PCR was used to detect genes for enterotoxins A, B, C, D, E, G, H, and I (sea, seb, sec, sed, see, seg, seh, and sei) and a disc-diffusion method was used to determine susceptibility to several classes of antimicrobials. All food handlers presented staphylococci on their hands and/or noses. The study found 58 Staphylococcus sp., of which 20.7% were CoPS and 79.3% were CoNS. Staphylococcus epidermidis was the most prevalent species. Fifty percent of Staphylococcus spp. isolated was positive for one or more enterotoxin genes, and the most prevalent genes were seg and sei, each with a frequency of 29.3%. Indeed, CoNS encoded high percentage of enterotoxin genes (43.5%). However, Staphylococcus aureus encoded even more enterotoxin genes (75%). Most isolates showed sensitivity to the antibiotics used for testing, except for penicillin (only 35% sensitive). The results from this study reinforce that coagulase-negative as well as coagulase-positive staphylococci isolated from food handler are capable of genotypic enterotoxigenicity.