Characteristics of Prophage Patterns and Virulence Gene Profiles among Methicillin-Resistant Staphylococcus aureus Isolates from Patients with Diabetic Foot Infections in a Referral Hospital in Tehran, Iran

Backgrounds: Diabetic patients are at risk of developing serious foot infections with methicillin-resistant Staphylococcus aureus (MRSA) strains, which are associated with high morbidity and mortality. This study aimed to investigate the frequency of different prophage types and virulence factors among MRSA strains isolated from patients with diabetic foot infections (DFIs) in a referral hospital in Tehran, Iran during ۲۰۱۹ and ۲۰۲۰. Materials & Methods: A total of ۲۳۸ S. aureus isolates were collected and confirmed using specific primers. The presence of staphylococcal enterotoxins (sea-seq) and hlb, sak, eta, etb, and tsst-۱ genes among MRSA isolates was tested using separate polymerase chain reaction (PCR) assays. Also, multiplex PCR was employed for prophage typing of MRSA isolates. Findings: A total of ۷۳ (۳۱%) isolates were confirmed as MRSA, among which four prophage types and ۱۳ different prophage patterns were identified, and prophage type SGF and prophage pattern ۷ consisting of SGB, SGF, SGFa, and SGFb types were the dominant ones. Also, ۱۱ enterotoxin-encoding genes and four virulence factor genes were detected among the isolates. All MRSA isolates were positive for sea, sek, seq, and hlb genes. Moreover, out of ۱۲ different enterotoxin patterns, most MRSA isolates were classified into enterotoxin pattern ۱, harboring three enterotoxin genes (sea, sek, and seq). Conclusion: This study results indicated the presence of different prophage types and virulence factor genes among MRSA strains isolated from DFI patients, which enable them to produce a variety of diseases.

Keywords:

Methicillin-resistant Staphylococcus aureus , Virulence factor patterns , Prophage typing , Diabetic foot infection