Trends in First Positive Culture Results in Major Burn Center Over a 10-Year Period.

Patients with severe burns are more vulnerable to infection, sepsis, and death. With heavy use of antimicrobials, changes in burn wound microbial and antibiotic resistance patterns have been reported; however, the literature remains scarce. This study assessed wound colonization trends in first positive cultures in our burn unit over the last decade. This is a retrospective cohort study including all patients admitted to our burn unit from July 2013 to June 2023. Demographics, TBSA, injury mechanism and admission information were obtained. Wound culture information including date of positive cultures, type of organisms, and antibiotic susceptibility data was also collected. Patients were stratified based on TBSA as small (<10%), moderate (10%-19.9%), and severe burns (≥20%). Descriptive statistics were obtained. Generalized linear models were fit to assess the trends of positive cultures over time for the 3 TBSA strata. A total of 2755 patients were included; median age was 38 years, 72.2% were male; 74.1%, 15.9%, and 10.1% presented with small, moderate, and severe burns, respectively. Wound cultures on initial presentation were performed in 40.3% of our population with 600 cases having positive first cultures; 84.7% grew Gram-positive, 35.7% Gram-negative, and 9.7% fungal organisms. Data showed an increase in Gram-positive and fungal species over the study period in first positive cultures of severe burn patients. We also found increasing rates of resistance for several antibiotics, including erythromycin, oxacillin, and vancomycin. Future studies are warranted to evaluate changes in microorganism growth throughout the hospital course of severe burn patients.