Background: Staphylococcus aureus (S. aureus) is isolated frequently from surgical site infections and other soft tissue infections. There are limited data examining the prevalence of methicillin resistant S. aureus (MRSA) among Egyptian patients after surgery. The current study determined the prevalence of MRSA isolated from surgical site and soft tissue infections at Minia University Hospital (MUH), determined their susceptibility to β-lactams and other antimicrobials, and examined their mecA gene expression.
Methods: A total of 208 hospitalized patients attending the General Surgery Department at MUH were enrolled and all had skin and soft tissue infections (SSTIs) of different causes. These 208 patients (143 males and 65 females) were suffering from surgical site infection (SSI; n=82), diabetic foot (n=52), abscess (n=45), or burn (n=29) infections. Samples were cultured on different media for isolation and identification of S. aureus and the isolates were screened for antibiotic susceptibility. All MRSA isolates were tested by polymerase chain reaction to detect the mecA gene responsible for methicllin resistance.
Results: 241 Staphylococcal species represented the most common isolates (64.8%) among 371 collected isolates from the 208 patients. Out of the 241 staphylococcal isolates, 127 were S. aureus (61% of the total patients). The prevalence of S. aureus among SSI, diabetic foot, abscess, and burn patients were 59%, 75%, 56%, and 52%, whereas that of MRSA was 16%, 17%, 13%, and 10%, respectively. MRSA isolates (n=31; 15% of patients) showed multiple resistance to at least one member of the antimicrobial groups tested with an average resistance to 6.6±1.9 antimicrobial groups. Polymerase chain reaction data showed that only 29 isolates of the MRSA isolates (94%) were positive for mecA gene.
Conclusions: Staphylococcus aureus isolates are the major pathogens responsible for wound and surgical site infections at MUH and MRSA are a potential threat for wound patients in Egypt.