Surveillance of Antimicrobial Resistance in Wound Infections: Insights from a Tertiary Care Hospital

Abstract

Background: Wound infections are a common cause of morbidity in both inpatient and outpatient settings. Increasing antimicrobial resistance (AMR) among wound pathogens complicates empirical treatment and highlights the need for localised surveillance. Stratified analyses by sex, age, and clinical setting are crucial for optimising antimicrobial stewardship and informing clinical decision-making. Aim: The present study investigated the spectrum of bacterial pathogens isolated from wound swabs and their antimicrobial resistance profiles in a large cohort of patients. The study further explored resistance patterns stratified by sex, age group, and patient setting (inpatient vs outpatient) to identify clinically relevant trends and support rational antibiotic use in wound management. Methods: We conducted a retrospective cross-sectional study analysing 2,577 wound swab cultures collected from January 2022 to December 2023. Bacterial isolates were identified and classified as Gram-positive or Gram-negative. Antimicrobial susceptibility was determined using standard disc diffusion methods. Resistance patterns were compared across sex, age groups (<12, 12–40, 41–60, >60 years), and patient settings (inpatient vs outpatient) using chi-square tests with a significance threshold of p < 0.05. Results: Gram-positive bacteria accounted for 52.5% of isolates, with Staphylococcus aureus being the most prevalent (42.1%). Gram-negative isolates included E. coli (17.0%) and Pseudomonas aeruginosa (8.8%). Resistance rates were significantly higher in male patients for several antibiotics, including oxacillin, amoxicillin, and cefotaxime (p < 0.05). Age-stratified analysis revealed increased resistance to ciprofloxacin and clindamycin among older age groups. Inpatients demonstrated significantly higher resistance to key antibiotics such as ceftriaxone (78.9% vs 61.2%), gentamicin (52.2% vs 22.2%), and meropenem (33.1% vs 20.7%) compared to outpatients (p < 0.00). Conclusions: High rates of AMR in wound infections—especially among inpatients, males, and older adults—highlight the need for stratified local surveillance to guide empiric therapy. These findings support the integration of culture-guided treatment, antimicrobial stewardship, and infection prevention measures to curb resistance and improve wound care outcomes.