Bacteriological Profile and Antimicrobial Resistance of Wound Isolates at Nepalgunj Medical College Teaching Hospital: A Cross-Sectional Study

Abstract

Introduction: Wound infections are a common cause of morbidity and are increasingly complicated by multidrug-resistant organisms.

Aims: To determine the bacteriological profile and antimicrobial susceptibility patterns of aerobic isolates from wound infection samples.

Methods: An analytical cross-sectional study was conducted at Nepalgunj Medical College Teaching Hospital from June 2025 to March 2026. Pus/wound swabs collected from patients with clinically suspected infections across various departments were processed for aerobic culture. Isolates were identified by standard biochemical tests, and antimicrobial susceptibility testing was performed using the modified Kirby-Bauer disc diffusion method in accordance with latest Clinical Laboratory Standards Institute guidelines. Multidrug resistance was defined as resistance to at least three different antibiotic classes.

Results: A total of 410 patients were enrolled, yielding 203 bacterial isolates. Staphylococcus aureus was the most common isolate (23.2%), followed by Klebsiella pneumoniae (21.2%), Escherichia coli (14.8%), and Pseudomonas spp. (13.8%). Overall, 99.5% of isolates were multi drug resistant, with 94.6% resistant to five or more antibiotic classes. Methicillin resistance was identified in 83.0% of S. aureus. Gram-negative isolates showed near-complete resistance to third-generation cephalosporins. While meropenem and polymyxin B retained activity against most Enterobacteriaceae, colistin resistance was high in Pseudomonas spp. (96.4%) and  Citrobacter spp. (100%). Vancomycin remained 100% effective against Gram-positive cocci.

Conclusion: This study highlights a critical prevalence of Multidrug-Resistant pathogens in pus and wound infections, primarily Methicillin-resistant Staphylococcus aureus and extensively drug-resistant Gram-negative bacilli. With conventional and last-resort antibiotics losing efficacy, therapeutic options are severely limited. Implementing routine surveillance, local antibiograms, and robust antimicrobial stewardship is essential.