Globally Expanding Carbapenemase Finally Appears in Spain: Nosocomial Outbreak of Acinetobacter baumannii Producing

Resistance of Acinetobacter baumannii clinical isolates to carbapenems is on the rise worldwide mainly in association with the production of OXA-23. Until recently, however, OXA-23 was absent in Spain. In this work, we report the molecular characteriza-tion of a hospital outbreak of OXA-23-producing A. baumannii in Barcelona caused by a multidrug-resistant (MDR) clone be-longing to international clone IC-II/sequence type ST85 between October 2010 andMay 2011. blaOXA-23 was carried in a plasmid of 90 kb and located within the composite transposon Tn2006. Acinetobacter baumannii is considered an important opportu-nistic pathogen causing pneumonia, bacteremia, and other respiratory and urinary tract infections (1, 2), and it is also respon-sible for nosocomial outbreaks worldwide, especially in intensive care units (ICUs) (3). Eradication of nosocomial infections caused by A. baumannii is particularly troublesome due to the ability of this bacterium to rapidly acquire antimicrobial resistance (4) and persist in the environment for long periods of time (5). Increased resistance to carbapenems in A. baumannii has raised special con-cerns during the last decade, especially since it is associated mostly with the production of acquired carbapenemases belonging to ei