Genetic diversity of Acinetobacter baumannii strains producing carbapenemases in Belarus: the role of "international high-risk clones" in the spread of resistance to carbapenems

Shek E.A.,Tapalski D.V., Skleenova E.Yu., Sukhorukova M.V., Karpov I.A., Edelstein M.V.

1 Institute of Antimicrobial Chemotherapy, Smolensk, Russia
2 Gomel State Medical University, Gomel, Belarus
3 Belorussian State Medical University, Minsk, Belarus

The rapid spread of extensively drug-resistant carbapenemase-producing A. baumannii strains has been noted in various regions of the world. The objective of the study is to assess the presence of various acquired carbapenemases among carbapenem-resistant A.baumannii clinical isolates collected in Belarus as well as the genetic diversity of the isolates and their attribution to the international “high-risk clones”
Ninety-one carbapenem-resistant A.baumannii clinical isolates were included in the study. Genes of acquired carbapenemases were detected by real-time PCR. Genetic diversity of isolates was assessed by SNP-typing, based on the analysis of single nucleotide polymorphisms (SNPs) in ten chromosomal loci. blaOXA-23-like, blaOXA-40-like, and a combination of blaOXA-23-like and blaOXA-40-like genes were detected in 4.4%, 93.4%, and 2.2% of the isolates, respectively. Using the SNP-typing, the A.baumannii isolates were assigned to 13 different genotypes belonging to 5 clonal complexes. 42.9% of the isolates were referred to international clonal complex CC92OXF/CC2PAS and 25.3% – to CC109OXF/CC1PAS. The vertical distribution of OXA-carbapenemase genes as part of "international high-risk clones" is shown, as well as the possibility of horizontal gene exchange between the representatives from various clonal groups.