Infection with enterotoxigenic Staphylococcus aureus as a concern in patients with gastroenteritis.

Abstract

Intestinal overgrowth of Staphylococcus aureus may promote unpleasant disorders in the human intestinal tract. This study assessed the prevalence of enterotoxigenic multidrug-resistant S. aureus (MDR-SA) in patients with gastroenteritis. Microbiological analysis of 345 faecal samples from patients with gastroenteritis was performed to detect infection with S. aureus in the absence of common enteric pathogens. Methicillin-resistant S. aureus (MRSA) was characterised by the cefoxitin disk diffusion method. PCR amplification of enterotoxin genes (sea, seb, sec, sed and see) was carried out on all S. aureus strains, and association of resistance patterns with the toxigenicity of strains was determined statistically. Infection with S. aureus was detected in 64 samples (18.6%), of which 51 (79.7%) and 41 (64.1%) were determined as MRSA and MDR-SA, respectively. Resistance to six antibiotic classes was the most common MDR pattern (48.8%; 20/41). In total, 50% of the strains (32/64) carried the studied enterotoxin genes; the most common was sea (56.1%), followed by sec (4.9%) and see (4.9%). These genes were more prevalent among MDR-MRSA (58.8%) compared with methicillin-sensitive S. aureus (15.4%) strains. These results confirmed the involvement of enterotoxigenic MRSA in the occurrence of gastroenteritis.