First detection of the blaOXA-23 gene in a multidrug-resistant A. baumannii clinical isolate from Cochabamba, Bolivia.

Dear Editor, Acinetobacter baumannii is an opportunistic pathogen responsible for severe infections and is associated with nosocomial outbreaks worldwide [1,2]. Carbapenems are the agents of choice to treat these infections, but multidrug-resistant isolates are being reported in hospitals worldwide [1]. One of the most important mechanisms of resistance to carbapenems is the production of carbapenem-hydrolyzing class D βlactamases encoded by blaOXA-23-like, blaOXA-40-like, blaOXA-51-like, blaOXA-58-like, and blaOXA-143-like genes [1]. The increase of the resistance in Acinetobacter baumannii makes the treatment due to these last-resort drugs challenging, as life-threatening infections due to carbapenem-resistant isolates are on the rise in developing countries such as Bolivia. The aim of this work was to analyze an especially virulent strain of Acinetobacter baumannii, named Bo995, obtained from a 51-year-old woman who was admitted to Viedma Hospital, a tertiary care university hospital in Cochabamba, Bolivia, with a diagnosis of odontogenic abscess; this process rapidly evolved to a severe sepsis and mediastinitis, which required surgery, exploratory thoracotomy, and drainage. One day after the procedure, the patient was admitted to the intensive care unit (ICU), where Acinetobacter baumannii with resistance to different antibiotics, including imipenem, was isolated from a tracheal aspirate. She died 10 days later due to general sepsis. In this work, we present the characterization of this virulent strain with regard to its antibiotic resistance and the identification of carbapenemases as a mechanism of carbapenem resistance.