Foreign Combatants Wounded in Ukraine Colonized by Extensively Drug-Resistant Organisms: A Potential Source of Global Dissemination

Background Human conflicts are associated with increased prevalence of multi-drug-resistant organisms (MDROs). Here, we investigate a collection of extensively drug resistant (XDR) bacteria recovered from foreign combatants wounded in Ukraine and evacuated to a U.S. military treatment facility in Germany between November 2022 and March 2024. Methods As part of routine surveillance, perirectal swabs were collected upon admission from all patients arriving from outside Germany. Whole genome sequencing, antimicrobial resistance gene (AMR) carriage, and antimicrobial susceptibility testing (AST) was determined for all isolates. Genetic relatedness to a set of isolates from soldiers treated at Ukrainian hospitals was assessed. Results Eighty-six deduplicated clinically significant MDROs were cultured from 32 combatants from 10 countries injured in Ukraine and subsequently treated in Germany. Twenty-three (72%) patients carried isolates from well-established global lineages of Enterococcus faecium (ST117), Klebsiella pneumoniae (ST147, 395), Acinetobacter baumannii (ST78) and Pseudomonas aeruginosa (ST235, ST773) that harbored carbapenemase (IMP, NDM, OXA), a 16S rRNA methyltransferase (ArmA, RmtB, RmtC), and/or the van operon, with 14 patients having >1 of these organisms. Sixteen combatants carried isolates genetically related to those from Ukrainian patients, suggesting acquisition occurred in Ukraine. AST revealed multiple isolates non-susceptible to cefiderocol (n = 8) or aztreonam-avibactam (n = 6), further complicating treatment options for carbapenemase-producing organisms. Conclusions This is the first study describing the epidemiology of MDROs collected from a population of foreign combatants injured in Ukraine. The findings forecast challenges to clinicians and infection prevention and control both in Ukraine and foreign healthcare systems as combatants are repatriated.