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Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of hospital- and community-acquired wound infections, often associated with multidrug resistance. Trauma wounds are particularly susceptible due to environmental exposure and delayed presentation. This study aimed to determine the prevalence of S. aureus and MRSA in surgical and trauma wound infections, assess antimicrobial resistance patterns, and identify associated risk factors. A total of 200 patients were enrolled (90 surgical, 110 trauma). Wound swabs were cultured for bacterial identification. MRSA detection was performed using cefoxitin disc diffusion, and inducible clindamycin resistance was evaluated via the D-test. Antimicrobial susceptibility testing followed CLSI guidelines. Demographic and clinical variables were analyzed for association with MRSA infection. Overall, 132/200 (66%) wound samples were culture-positive, with trauma wounds exhibiting higher positivity (83/110; 75.5% ± 5.1) than surgical wounds (49/90; 54.4% ± 4.7, p < 0.01). S. aureus accounted for 80/132 (60.6% ± 4.2) isolates. Among these, 35/80 (43.7% ± 3.5) were MRSA, with trauma wounds contributing 20/40 (50% ± 3.5) and surgical wounds 15/40 (37.5% ± 3.2). Polymicrobial growth occurred in 18/83 trauma wounds (21.7% ± 2.8) versus 9/49 surgical wounds (18.4% ± 2.1). MRSA isolates showed high resistance to erythromycin (28/35; 80% ± 4.5), clindamycin (23/35; 65.7% ± 5.2), and gentamicin (21/35; 60% ± 4.1), whereas all remained susceptible to vancomycin and linezolid. Inducible clindamycin resistance was observed in 8/35 MRSA (22.9% ± 1.5) and 5/45 MSSA (11.1% ± 1.2). Significant risk factors included prior antibiotic use (28/88; 31.8% ± 2.4), ICU admission (20/64; 31.2% ± 2.6), diabetes (14/40; 35% ± 3.8), and prolonged hospital stay (>7 days; 30/130; 23.1% ± 2.2). Trauma wounds have higher culture positivity, MRSA prevalence, and multidrug-resistant isolates compared to surgical wounds. Continuous surveillance, D-test screening, and targeted infection control strategies are critical to reduce MRSA burden and improve patient outcomes.