Retrospective analysis of the microbiological landscape of bacteremia after blast injury: experience of the 2022–2024 Russian-Ukrainian war

Background. Against the backdrop of ongoing russian aggression, the need for effective treatment of combat trauma is becoming increasingly urgent. Infectious complications, including sepsis, remain a significant concern, with up to 14 % of wounded individuals developing bacteremia compared to 4 % in civilian trauma. Studies have shown that S.epidermidis and E.coli are the most frequently detected blood isolates, while ESKAPE pathogens account for 8 % of cases. It should be noted that the literature data on bacteremia in blast injury is limited. This study purposed to evaluate the microbiological landscape of bacteremia and the antibiotic susceptibility of pathogens in military personnel with blast injury. Materials and methods. A retrospective cohort, single-center study was conducted in wounded servicemen treated at a tertiary care facility in Kyiv between February 24, 2022, and March 14, 2024. Inclusion criteria were blast injury as a result of hostilities, availability of blood culture results, admission to a medical facility within < 30 days after trauma. Data collection encompassed demographic, clinical, and microbiological information. Statistical analysis was performed using R and Microsoft Excel. Results. The study included 181 patients (mean age 38.00 ± 0.72 years), of whom 155 were discharged and 26 died. A total of 313 blood cultures were performed, yielding 318 isolates. No growth was detected in 233 cases (73.27 %, 95% confidence interval (CI) 68.41–78.13), while gram-positive pathogens were found in 47 isolates (14.78 %, 95% CI 10.88–18.68), gram-negative pathogens in 22 (6.92 %, 95% CI 4.13–9.71), and fungi in 16 (5.03 %, 95% CI 2.63–7.43) (p < 0.001). The most common isolates were S.epidermidis (7.86 %, 95% CI 4.9–10.82), Candida spp. (4.72 %, 95% CI 2.39–7.05), and K.pneumoniae (4.09 %, 95% CI 1.91–6.26). Among these, 77.78 % (n = 35/45) of gram-positive and 100 % (n = 20/20) of gram-negative isolates were resistant to ≥ 2 antibacterial agents. Gram-positive isolates demonstrated high susceptibility to tigecycline (100 %), amikacin (84.85 %), and linezolid (81.4 %), while gram-negative isolates — to colistin (100 %) and tigecycline (73.33 %). The presence of gram-negative bacteria in the blood significantly increased the risk of death (odds ratio 15.48, 95% CI 4.67–57.17, p < 0.001). Conclusions. Our findings confirm the predominance of gram-positive isolates in bacteremia, but gram-negative sepsis poses the greatest risk. More than 77 % of identified isolates were multidrug-resistant, with high sensitivity observed only to last-resort antibiotics.