Whole-genome sequencing analysis of a carbapenem-resistant Acinetobacter bereziniae clinical strain.

BROVEDAN, M; MARCHIARO, P; MORAN-BARRIO, J.; VIALE, A; LIMANSKY, A

Congreso; LI Reunión SAIB 2015; 2015

Acinetobacter bereziniae is rarely found in healthcare-associated infections. We recently isolated a carbapenem-resistant A. bereziniae strain (HPC229) from a leukemia patient hospitalized in Rosario, Argentina, and recently reported the complete sequence of a blaNDM-1-harboring plasmid pNDM229 present in this strain (Brovedan et al, AAC July 2015, in press). Here, we describe relevant traits of HPC229 through whole-genome sequencing studies (WGS). Phylogenetic analyses based on 16S rRNA, gyrB, rpoB, and rpoD genes showed the closest relationship of HPC229 with the carbapenem-resistant A. bereziniae CHI-40-1 among other related strains. In addition, the corresponding blaOXA229-like chromosomal genes typical of this species were 99.3 % identical between these two strains. HPC229 and CHI-40-1 harbored blaNDM-1 genes in pNDM-BJ01-like plasmids displaying distinctive features between them. Chromosomal carO genes coding for outer membrane proteins associated to imipenem uptake displayed only 77.8 % identity between both strains revealing distinct carO variants. Lack of congruence between phylogenetic trees based on housekeeping and carO genes indicated exchange of carO among the A. bereziniae population mediated by horizontal gene transfer. WGS analyses may thus help to better understand the evolution and dissemination of carbapenem resistance among the Acinetobacter global population.