Bacterial Profile and Antimicrobial Susceptibility Patterns of Postoperative Wound Isolates in Selected Hospitals in Eastern Libya

Abstract

Background: Surgical site infections (SSIs) represent major complications associated with surgical procedures, leading to increased morbidity, prolonged hospitalization, elevated healthcare costs, and amplified antimicrobial resistance worldwide. The microbiological spectrum of SSI pathogens and their resistance profiles vary significantly across geographical regions, healthcare facilities, patient cohorts, and local infection control practices. Objective: This study aimed to identify bacterial pathogens associated with postoperative surgical site infections among patients across selected healthcare facilities in Al-Marj, Tocra, Taknis, and Benghazi, Eastern Libya, and to determine their antimicrobial susceptibility patterns. Methods: A multicenter cross-sectional study was conducted between April and July 2026, examining 100 clinical wound specimens and bacterial isolates from patients with suspected postoperative SSIs. Isolates were processed using conventional microbiological methods, Gram staining, and phenotypic biochemical tests, while antimicrobial susceptibility was evaluated via the Kirby-Bauer disk diffusion method. Data were analyzed using SPSS version 18, utilizing descriptive statistics and chi-square tests with significance set at P < 0.05. Results: Gram-negative bacteria accounted for 58.0% of isolates, while Gram-positive bacteria comprised 42.0%. The most prevalent isolates were Escherichia coli and Staphylococcus aureus (23.0% each), followed by Staphylococcus epidermidis (21.0%), Pseudomonas aeruginosa (19.0%), and Klebsiella spp. (14.0%). Bacterial distributions and Gram-stain classifications varied significantly among hospitals (P < 0.001 and P = 0.002, respectively). Significant associations with bacterial species were observed for susceptibility to ampicillin (P < 0.001), gentamicin (P = 0.001), and ceftazidime (P = 0.046). Conclusion: The findings reveal considerable bacterial diversity and varying antimicrobial resistance profiles among postoperative wound infections in Eastern Libya, underscoring the critical need for continuous surveillance, standardized susceptibility testing, and robust antimicrobial stewardship programs.