Characteristic Correlation between Staphylococcal Isolates from Wounds and Nares of Diabetic Foot Patients Living in Erbil City, Iraq.

INTRODUCTION

Foot ulcers are a common and serious complication in patients with diabetes mellitus. Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) may serve as a reservoir for autoinfection. This study aimed to investigate the association between S. aureus isolates obtained from nasal passages and foot infections in diabetic patients.

METHODS

Nasal and foot wound swabs were collected from 84 diabetic patients. Bacterial identification and antibiotic susceptibility testing were performed using the VITEK 2 system. Methicillin resistance was determined using Oxacillin Salt Agar Screen, PBP2a assays, and mecA gene detection. Genetic correlation between nasal and wound isolates was assessed by pulsed-field gel electrophoresis (PFGE).

RESULTS

S. aureus was the most prevalent isolate, accounting for 33.1% of samples. Methicillin resistance was detected in 55.1% of foot wound isolates and 73.3% of nasal isolates. The mecA gene was identified in 95.3% of both S. aureus and coagulase-negative Staphylococci. PFGE analysis showed 100% genetic homology between paired nasal and wound isolates.

DISCUSSION: The data confirmed that S. aureus is the predominant bacterium in diabetic foot lesions. Our findings also suggest that these infections in diabetic patients are likely of endogenous origin.

CONCLUSION

Diabetic foot patients carrying S. aureus in the nares are at high risk of self-contamination. These findings highlight the need for routine nasal screening and decolonization strategies to reduce infection risk in this vulnerable population.