A Cross Sectional Study on Bacteriological Profile of Post-Operative Wound Infections in A Tertiary Care Hosputal

Background: Post-operative wound infections are a common complication in surgical patients, leading to increased morbidity, prolonged hospital stay, and higher healthcare costs. The emergence of multidrug-resistant (MDR) organisms further complicates management, necessitating local epidemiological and antimicrobial susceptibility data.

Objectives: To determine the bacteriological profile, antimicrobial susceptibility patterns, and prevalence of drug-resistant strains, including MRSA, ESBL, and MDR bacteria, in post-operative wound infections.

Materials and Methods: A cross-sectional study was conducted at the Diagnostic Microbiology Division, Karpagam Faculty of Medical Sciences and Research, Coimbatore, from January 2019 to June 2020. A total of 250 patients with post-operative wound infections were included. Specimens were collected from wound sites, processed for Gram staining and culture, and pathogens were identified using standard biochemical tests. Antimicrobial susceptibility was assessed by Kirby-Bauer disk diffusion. ESBL and MRSA detection followed CLSI guidelines. Data were analyzed using SPSS and Epi-Info.

Results: Out of 250 wound samples, 184 (73.6%) showed bacterial growth. Gram-negative bacilli (64.6%) predominated over Gram-positive cocci (35.4%). Common isolates included Staphylococcus aureus (MSSA 22.3%, MRSA 12%), Escherichia coli (20.1%), and Pseudomonas aeruginosa (16.8%). MRSA showed 100% sensitivity to vancomycin and 90.9% to linezolid. Among Gram-negative bacilli, carbapenems and aminoglycosides demonstrated the highest efficacy. ESBL producers constituted 28.3% of isolates, predominantly E. coli (53.8%), while MDR strains were observed in 5.4% of isolates.

Conclusion: Post-operative wound infections are primarily caused by Gram-negative bacilli and S. aureus, with a significant proportion of drug-resistant strains. Vigilant antimicrobial stewardship, timely identification of pathogens, and tailored therapy based on susceptibility patterns are crucial to optimize patient outcomes and limit the spread of resistance.