Molecular epidemiology of multidrug-resistant Acinetobacter baumannii isolates in a university hospital in Nepal. Acinetobacter baumannii

The emergence of multidrug-resistant (MDR) Acinetobacter baumannii has become a serious worldwide medical problem. To clarify the genetic and epidemiological properties of MDR Acinetobacter baumannii clinical isolates in a medical setting in Nepal, a total of 246 Acinetobacter spp. isolates obtained from single patients were screened for MDR A. baumannii with antimicrobial disk susceptibility tests. The whole genomes of the MDR isolates were sequenced by MiSeq (Illumina). Phylogenic trees were constructed from the SNP concatemers. MLSTs were deduced and drug resistant genes were identified. Fifty percent of Acinetobacter spp. isolates (122/246) were MDR A. baumanni, with the majority resistant to aminoglycosides, carbapenems, and fluoroquinolones but not to colistin and tigecycline. These isolates harbored a 16S rRNA methylase gene, armA, and blaNDM-1, blaOXA-23 or blaOXA-58. MDR A. baumannii isolates belonging to CC1 and CC2, as well as a novel clonal complex, CC149, have spread throughout a medical setting in Nepal. The MDR isolates harbored genes encoding carbapenemases (OXAs and NDM-1) and 16S rRNA methylases (ArmA).