Studies on Enterotoxigenic Staphylococcus aureus among Food Handlers in Khartoum State

Abstract

Staphylococcus aureus (S. aureus) is a major cause of food poisoning due to their ability to produce enterotoxins. Food handlers carrying enterotoxin- producing S. aureus in their noses or hands can contaminate food leading to food poisoning. Different methods have been used to detect these toxins; DNA amplification methods can show the presence of enterotoxigenic strains of S. aureus before the expression of enterotoxins on the basis of specific gene sequences. The aim of this study was to asses presence of enterotoxigenic S. aureus in nose and hand of food handlers. Nasal and hand (right and left) swabs were collected from each food handlers. The swabs were inoculated on mannitol salt agar plates and incubated aerobically overnight. Identification of S. aureus isolates was done by Gram’s stain and biochemical tests. Detection of genes responsible for production of enterotoxin (A, B and C) was carrying out by PCR. Out of 165 swabs investigated, 48(29%) were S. aureus. Of them 21(43.7%) were nasal isolates, while the rest 27(56.3%) were isolated from hands. Out of the 48 S. aureus isolated, 9 (18.7%) were associated with staphylococcal enterotoxin A (SEA) gene, 7(14.5%) was associated with staphylococcal enterotoxin B (SEB) gene and there is no isolate associated with staphylococcal enterotoxin C (SEC). This study concluded that there is high percentage of S. aureus carrier among food handlers. The most prevalent enterotoxin gene was A, followed by B. Further studies are required to validate this study and to detect other enterotoxin genes.