Bacterial Isolates and their Antimicrobial Susceptibility Patterns of Wound Infections among Patients in Surgery Department of Tertiary Health Care Centre

Abstract

Introduction:  Wound infections are an important cause of delayed healing and morbidity among surgical patients, and increasing antimicrobial resistance complicates their management. Identification of bacterial pathogens and determination of their antimicrobial susceptibility patterns are important for appropriate antimicrobial selection.

Aim: To determine the bacterial profile and antimicrobial susceptibility patterns of wound infections among patients attending the Surgery Department of a tertiary healthcare centre.

Methods:  A retrospective study is done among clinical samples obtained from both inpatients and outpatients attending Surgery Department of National Institute of Medical Sciences and Research (NIMS&R) Hospital from February 2026 to July 2026. The isolates were identified and their antibiotic sensitivity was determined following the standard protocol and CLSI guidelines.

Results:  A total of 348 bacterial isolates were included in the analysis. Gram-negative organisms predominated, accounting for 67.2%, while Gram-positive organisms accounted for 32.8%. Staphylococcus spp. was the most frequently isolated organism (28.4%), followed by Escherichia coli (23.3%), Klebsiella pneumoniae (12.9%), and Pseudomonas spp. (7.8%). Most isolates were recovered as single-organism infections (91.38%), while multiple microbial isolates accounted for 8.62%. Wound swabs constituted the majority of specimens (66.4%). High resistance was observed among Staphylococcus spp. to penicillin (72.7%), E. coli to ampicillin and ciprofloxacin (81.4% each), K. pneumoniae to ampicillin (86.6%), and Pseudomonas spp. to cefepime and cefoperazone–sulbactam (66.6% each). Relatively high susceptibility was observed to amikacin among E. coli (85.1%) and to gentamicin among K. pneumoniae (66.6%) and Pseudomonas spp. (77.7%).

Conclusion: The study demonstrated a diverse bacterial profile among wound infections, with Gram-negative organisms predominating and substantial resistance to several commonly used antimicrobials. The variation in susceptibility among bacterial species highlights the importance of bacterial identification and antimicrobial susceptibility testing for appropriate management of wound infections in the study setting.