Characterization of carbapenem-resistant Acinetobacter baumannii in Brazil (2008-2011): countrywide spread of OXA-23-producing clones (CC15 and CC79)

The study investigated the genetic relationship of carbapenem-resistant Acinetobacter baumannii clinical isolated from inpatients during 2008-2011 from 11 Brazilian states. Antimicrobial susceptibility profile was determined by disc diffusion method and Etest Polymerase chain reaction was applied for carbapenemase genes, and ISAba1. Isolates were subjected to pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) for molecular typing. Most of the isolates showed high resistance rates to antibiotics tested. The bla(OXA-51-like) gene was found in all isolates, and 146 (94.2%) isolates were positive for bla(OXA-23-like). In the most OXA-23-producing isolates, the bla(OXA-23-like) gene was accompanied by ISAba1. A total of 146 OXA-23-producing isolates were clustered into 28 genotypes by PFGE. Molecular analysis by MLST identified 13 sequence types (STs). The most prevalent PFGE profiles were designated as ST15 (CC15), ST1 (CC1), and ST79 (CC79). This study showed the widespread of clonal complexes of A. baumannii harboring the bla(OXA-23-like) gene in different Brazilian states. (C) 2014 Elsevier Inc. All rights reserved.