Acinetobacter baumannii as a cause of sepsis

To analyze the frequency and antimicrobial resistance of Acinetobacter baumannii isolated from blood cultures.

Blood cultures of all consecutive patients hospitalized in different departments of the University Clinical Centre of Sarajevo from January 2003 to December 2010 were processed by "BACTEC 9120" system. The isolates were identified by conventional methods. Susceptibility testing was performed by disc-diffusion method following guidelines from the Clinical Laboratory Standards Institute (CLSI).

A total of 93,215 blood cultures were examined, 6,338 (6.8%) were positive. Acinetobacter baumannii was isolated in 283 (4.5%) cases. Overall yearly resistance rates to antibiotics had an increasing trend during the eight year period: amicacin from 45.3% to 71.4%; gentamycin from 70.6% to 83.2%; ciprofloxacin from 60.6% to 85.8%; carbapenems (imipenem and meropenem) from 0% to 52.8%. Carbapenem-resistant Acinetobacter baumannii (CRAB) emerged in 2009 and was rapidly disseminated in intensive care units. Resistance to tobramycin and colistin was not detected.

High resistance rates and an increase of Acinetobacter baumannii to all antimicrobials, especially to carbapenems, were noted. The dissemination of carbapenem-resistant isolate may indicate the appearance of untreatable infection by this organism. It points out the rationality in prescribing antimicrobial drugs.