Prevalence of enterotoxin genes (SEA to SEE) and antibacterial resistant pattern of Staphylococcus aureus isolated from clinical specimens in Assiut city of Egypt

Abstract

Abstract Background Infections in communities and hospitals are mostly caused by Staphylococcus aureus strains. This study aimed to determine the prevalence of five genes (SEA, SEB, SEC, SED and SEE) encoding staphylococcal enterotoxins in S. aureus isolates from various clinical specimens, as well as to assess the relationship of these isolates with antibiotic susceptibility. Traditional PCR was used to detect enterotoxin genes, and the ability of isolates expressing these genes was determined using Q.RT-PCR. Results Overall; 61.3% (n = 46) of the samples were positive for S. aureus out of 75 clinical specimens, including urine, abscess, wounds, and nasal swabs. The prevalence of antibiotic resistance showed S. aureus isolates were resistant to Nalidixic acid, Ampicillin and Amoxicillin (100%), Cefuroxime (94%), Ceftriaxone (89%), Ciprofloxacin (87%), Erythromycin and Ceftaxime (85%), Cephalexin and Clarithromycin (83%), Cefaclor (81%), Gentamicin (74%), Ofloxacin (72%), Chloramphenicol(59%), Amoxicillin/Clavulanic acid (54%), while all isolates sensitive to Imipinem (100%). By employing specific PCR, about 39.1% of isolates were harbored enterotoxin genes, enterotoxin A was the most predominant toxin in 32.6% of isolates, enterotoxin B with 4.3% of isolates and enterotoxin A and B were detected jointly in 2.1% of isolates, while enterotoxin C, D and E weren’t detected in any isolate. Conclusion This study revealed a high prevalence of S. aureus among clinical specimens. The isolates were also multidrug resistant to several tested antibiotics. Enterotoxin A was the most prevalent gene among isolates. The presence of antibiotic resistance and enterotoxin genes may facilitate the spread of S. aureus strains and pose a potential threat to public health.

Keywords

• Staphylococcus aureus
• Antibiotic resistance
• Enterotoxin
• Real-time PCR