Molecular Epidemiology Of Carbapenem-Resistant Acinetobacter Baumannii From Southern Brazil

Background and Objectives: carbapenem resistance in Acinetobacter baumannii has reached extremely high levels worldwide, and class D OXA-type carbapenemases are the main associated mechanism. This study aimed to assess the phenotypic and molecular profile of clinical carbapenem-resistant A. baumannii (CRAb) isolates from a southern Brazilian border region. Methods: A. baumannii species was identified by the presence of the bla(OXA-51) gene, and the susceptibility profile was determined by broth microdilution. The main carbapenemases were investigated by PCR and the molecular typing was performed by PFGE. Results: during the study, a total of 36 CRAb were recovered, of which 85.7% were from respiratory tract samples from ICU patients. High level resistance to were found in contrast to 100% of susceptibility for polymyxin B. The bla(OXA-23) gene was present in 34 isolates and was the only one detected other than bla(OXA-51). Molecular typing revealed the presence of four clonal strains, two of them endemic during the period of the study. Conclusion: to the best of our knowledge, our study brings the first data about resistance profile in Acinetobacter in the western border of southern Brazil and make aware of endemic clones of CRAb-producing-OXA-23 in this region of state, contributing for the construction of the national epidemiologic scenario of CRAb.