Classical Enterotoxin Genes Carriage among Staphylococcus aureus from Food Handlers in a Nigerian University Community

Abstract

Enterotoxigenic Staphylococcus aureus is one of the major causes of food poisoning due to asymp¬tomatic carriage. This study aimed to determine the presence of S. aureus in the nasal cavities and hands of food handlers in a university setting in Nigeria. It also assessed their susceptibility to antibiotics and examined the carriage of classical enterotoxin genes. Swab samples (120) collected from the anterior nar¬es and hands of 40 food handlers were screened for S. aureus using standard microbiological methods. Susceptibility testing for cefoxitin, ciprofloxacin, and vancomycin was performed using the disk diffusion method. Staphylococcal enterotoxin (sea - sed) genes were detected by multiplex PCR. A total of 34 S. aureus isolates were identified, with 12 from the nares, 12 from the right hand, and 10 from the left hand. Ciprofloxacin resistance was found in 55.9% of the isolates, cefoxitin resistance was 32.4%, and none was susceptible to vancomycin. The sec gene was the most prominent, accounting for 26.5% of all enterotox¬in genes identified. No isolates harbored the seb gene but a nasal methicillin-susceptible S. aureus strain from one of the food handlers harbored three enterotoxin genes (sec, sed, see) simultaneously. Three (3) sec-carrying strains were resistant to the three antibiotics tested. The study revealed a substantial proportion of carriers of classical enterotoxin genes among the food handlers examined. It also showed resistance to antibiotics relevant to the management of staphylococcal infections. These strains could spread through the community.