Increasing resistance of nosocomial Acinetobacter baumannii: are we going to be defeated?

To investigate the change of the antibiotic resistance profiles of the nosocomial Acinetobacter baumannii isolates in intensive care units (ICUs) between the years 2008 and 2011.

A. baumannii isolates that were responsible for ICU-acquired nosocomial infections between 2008 and 2011 were included in the study. The susceptibility rates of the antibiotics that are mainly used in the treatment of Acinetobacter infections were compared by years. Clinical and Laboratory Standards Institute criteria were used to determine antimicrobial susceptibility.

There were 252 infection episodes detected in 229 hospitalized patients in the ICU that were caused by A. baumannii. Imipenem resistance was found as 98.9% in 2011 whereas it was 54% in 2008. A significant increase was observed for meropenem resistance from 2008 (73.5%) to 2011 (98.9%). Colistin resistance, confirmed by E-test, was found in 4 strains. The resistance rates of other antimicrobial agents were as follows: ampicillin/sulbactam 95.7% and 93.5%, cefoperazone/sulbactam 45.7% and 90.3%, netilmicin 41.7% and 53%, gentamicin 96% and 87.2%, and trimethoprimsulfamethoxazole 91.7% and 72%, in 2008 and 2011, respectively. The resistance rate to tigecycline increased to 81.3% in 2011 from 12.5% in 2008.