Genomic mapping of ST85 blaNDM-1 and blaOXA-94 producing Acinetobacter baumannii isolates from Syrian Civil War Victims

Objectives: The rapid emergence of carbapenem-resistant Acinetobacter baumannii is a global health concern. A comparative genomic analysis was performed on two ST85 A. baumannii strains harboring blaNDM-1 and blaOXA-94 collected in Lebanon from Syrian Civil War victims. Methods: Genome sequencing data of ACMH-6200 and ACMH-6201 were used for in silico extraction of multilocus sequence types (MLST), resistance genes, and virulence factors. Plasmids were genetically mapped in silico and using PCR-based replicon typing (PBRT). The genetic environment of blaNDM-1 and blaOXA-94 was determined, and whole-genome single nucleotide polymorphism (wgSNP) analysis in comparison with 41 publicly available A. baumannii genomes was performed. Results: Tn125 carrying blaNDM-1 was truncated by the insertion of ISAba14 downstream of dct, generating ΔTn125. blaOXA-94 was upstream of ISAba13 and ISAba17. Resistance to ceftazidime could be attributed to AmpC cephalosporinase encoded by blaADC-25, and to blaNDM-1 on plasmids. GyrA (S83L) and ParC (S80L) substitutions conferred resistance to fluoroquinolones. wgSNP analysis separated the isolates based on their sequence types. Conclusions: The role of refugees in the transmission of antimicrobial resistance in developing countries is understudied. As such, this study sheds light on the correlation between population mobility and the importation of drug-resistant pathogens. It also highlights the manifold mechanisms underlying antibiotic resistance in A. baumannii. Keywords: Acinetobacter baumannii, blaNDM-1, blaOXA-94, Plasmids, wgSNP