Phenotypic and genotypic characterization of antibiotic resistance in military hospital-associated bacteria from war injuries in the Eastern Ukraine conflict between 2014 and 2020

Abstract

Background: Infections from the recent conflict in Ukraine have been poorly investigated.

Aim: To describe the phenotypic and genotypic mechanisms of antibiotic resistance in pathogens associated with war injuries in the Ukraine conflict.

Methods: This report describes a retrospective multi-centre microbiological survey conducted in four Ukrainian military hospitals between 2014 and 2020. The phenotypes of 813 organisms obtained from 1061 tests of 162 patients were analysed. Fifty-two isolates underwent whole-genome sequencing.

Findings: Resistance was highest in Acinetobacter baumannii, with 92.5% ((48/52) 95% confidence interval (CI) 81.8-97.9) resistant to fluoroquinolones, 83.0% ((43/52) 95% CI 70.2-91.9) resistant to aminoglycosides, and 67.9% ((37/52) 95% CI 53.7-80.1) resistant to carbapenems. In contrast, resistance to carbapenems was 55.6% ((30/52) 95% CI 41.4-69.1) in Pseudomonas aeruginosa, 42.9% in Escherichia coli ((12/28) 95% CI 24.5-62.8), and 32.8% in Klebsiella pneumoniae ((20/34) 95% CI 21.3-46.0). Multi-drug-resistant strains harboured an abundance of antibiotic resistance genes. K. pneumoniae co-produced class A and D β-lactamases, in one case with blaNDM-1 and rmtC 16S rRNA methyltransferase. A. baumannii carried class A and D β-lactamases but not metallo-β-lactamases; in four isolates, carbapenemases were present with the RmtASE gene armA. P. aeruginosa harboured a wide range of class A and D β-lactamases along with metallo-β-lactamases, as well as the RmtB4 RmtASE gene. Gram-positive cocci were generally sensitive to the tested antibiotics.

Conclusion: The incidence of resistance among the studied pathogens was higher than that in Ukrainian civilian hospitals and European countries. The discovery of P. aeruginosa, A. baumannii, and K. pneumoniae co-producing carbapenemases and RmtASEs is of particular importance, and hospitals should be vigilant for their emergence.

Keywords: Bacterial multiple drug resistance; Military; Phenotype; Ukraine; Whole-genome sequencing.