Distinct Genetic Diversity of Carbapenem-Resistant Acinetobacter baumannii from Colombian Hospitals

The global success of multidrug-resistant Acinetobacter baumannii has been associated with the dissemination of a high-risk clone designated clonal complex (CC) 92 B (Bartual scheme)/CC2 P (Pasteur scheme), which is the most frequent genetic lineage in European, Asian, and North American carbapenem-resistant Acinetobacter isolates. In these isolates, carbapenem resistance is mainly mediated by β-lactamases encoded by bla OXA-23-like , bla OXA-24-like , bla OXA-51-like , and/or bla OXA-58-like genes. In this study, we characterized the population genetics of 121 carbapenem-resistant A. baumannii complex isolates recovered from 14 hospitals in seven cities in Colombia (2008–2010). Multiplex PCR was used to detect bla OXA-23-like , bla OXA-24-like , bla OXA-51-like , and bla OXA-58-like genes. Molecular typing was performed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). PCR showed that 118 (97.5%) of the isolates were positive for both bla OXA-23-like and bla OXA-51-like genes, and three other isolates were only positive for bla OXA-51-like . PFGE identified 18 different pulsotypes, while MLST identified 11 different sequence types (STs), seven of which had not been previously described in Acinetobacter . None of the STs found in this study was associated with CC92 B /CC2 P . The most widespread STs in our isolates belonged to ST636 and their single-locus variants ST121/ST124/ST634 (CC636 B ) followed by STs belonging to CC110 B . Our observations suggest a wide distribution of diverse A . baumannii complex clones containing bla OXA-23-like in Colombian hospitals (especially CC636 B and CC110 B ) that differ from the high-risk clones commonly found in other regions of the world, indicating a distinct molecular epidemiology of carbapenem-resistant Acinetobacter spp. in Colombia.