Bacteriological profile and antimicrobial resistance patterns in clinical isolates from a tertiary burns ICU: A retrospective comparative analysis of carbapenem resistance and invasion.

Abstract

Burn injuries are a major cause of morbidity and mortality in low- and middle-income countries, with infections and antimicrobial resistance posing significant challenges. Carbapenem-resistant Gram-negative bacteria are particularly concerning in burn intensive care units. Aim of the study was to evaluate bacteriological profile, and antimicrobial susceptibility patterns of burn ICU patients, and identify risk factors associated with carbapenem resistance, invasive infections, and in-hospital mortality. This retrospective, single-centre study included all patients admitted to a 30-bed burns ICU in north India between January and December 2024, whose clinical sample was received for microbiological investigations. Data on demographics, clinical parameters, and microbiological findings were extracted from hospital records and analysed using chi-square, Fisher's exact, Mann-Whitney U tests, and multivariable logistic regression. Out of 246 patients included, the mean age was 29.1 ± 20.4 years and mean total body surface area (TBSA)% was 39.0 ± 19.9%. Overall mortality was 42.3%. A total of 1586 samples yielded 1057 pathogens, predominantly Gram-negative bacteria (Pseudomonas aeruginosa 36.1%, Acinetobacter baumannii 22.3%, Klebsiella pneumoniae 18.8%). Carbapenem resistance was observed in 85.3% of patients and was significantly associated with higher TBSA% (p<.001), longer hospital stays (p=.022), and mortality (p<.001). Invasion was present in 27.6% and was significantly associated with both carbapenem resistance and mortality. Multivariable logistic regression identified TBSA% (OR: 1.07, p<.001) and invasion (OR: 4.14, p=.001) as independent predictors of mortality. Carbapenem resistance and invasive infections are highly prevalent in burn ICU patients, underscoring the urgent need for robust infection control, regular antibiogram surveillance, and targeted antimicrobial stewardship in burn care settings.