Microbial etiology and antibiogram profile of surgical site infections in orthopaedic open reduction and internal fixation surgeries from a tertiary care hospital

Background: Surgical site infections (SSIs) are the most common hospital-acquired infections, constituting around 20% of all healthcare-associated infections. In India, surveillance of SSI, particularly after discharge, is limited; therefore, the true burden and microbiological patterns of these infections may be underestimated. The objective was to describe the microbiological profile and antimicrobial susceptibility patterns in patients who developed SSI after open reduction and internal fixation (ORIF) for closed fractures. Methods: A retrospective study was conducted, and data were collected from patients diagnosed with SSI following ORIF for closed fractures over a period of one year from January 2025 to December 2025. SSI surveillance forms were completed for all diagnosed SSI cases according to CDC/NHSN SSI criteria. Pus aspirate and tissue biopsy were collected for microbiological analysis, and antimicrobial susceptibility testing was performed. Results: Of 1,290 patients reviewed, 21 developed SSI, yielding an SSI rate of 1.62%. The mean age was 39.6 years with marked male predominance. Comorbidities included diabetes mellitus and immunocompromised status (19% each), with 96% being emergency surgeries. The mean time to SSI detection was 18.2 days. Of 21 samples, 15 (71.4%) yielded bacterial isolates. Enterobacter species were most frequent (46.6%), followed by Klebsiella pneumoniae (20%) and MRSA (20%). Enterobacteriaceae showed high resistance to ciprofloxacin (100%), piperacillin-tazobactam (80%), and amikacin (77.8%). MRSA was resistant to erythromycin (100%) and clindamycin (66.7%). Most cases were managed with debridement, antibiotic and implant retention; implant removal was required in 9.5% of cases. Conclusions: SSIs following ORIF for closed fractures occurred at a rate of 1.62%, with Gram-negative pathogens, particularly Enterobacter species, emerging as the predominant organisms. High resistance to ciprofloxacin, amikacin, and piperacillin-tazobactam underscores the need for local microbiological data for empirical therapy for established infections. Strengthening SSI surveillance, infection control practices, and antimicrobial stewardship is essential to reduce SSI burden in orthopaedic trauma patients.