Abstract

Bacteremia due to Acinetobacter baumannii is a common problem in hospitals worldwide. Physicians in the intensive care units (ICUs) encountered a serious challenge of finding a drug to cure the extended-spectrum beta-lactamase (ESBL) producing and multi-drug resistant (MDR) A. baumannii bacteremia. Our aim was to determine the frequency of A. baumannii bacteremia in an Iranian hospital ICUs, their antibiotic susceptibility patterns, and the frequency of ESBLs by a cross-sectional study. A total of 340 patients admitted to ICUs during a 6 month period of study were investigated for bacteremia due to A. baumannii. Bacteria isolates from blood specimens were identified as A. baumannii by API 20NE system. Antimicrobial susceptibility was studied with disk diffusion method. Detection of ESBLs was done by double disk synergy test. Of the 340 patients investigated, bacteremia was found in 114 cases (33%). A. baumannii was diagnosed as the etiological agent of bacteremia in 69 cases (60.5%). All the isolates were multi-drug resistant. Except one, all the remaining isolates (98.6%) were resistant to at least 7 of 13 tested antibiotics. Pandrug-resistance was observed in 4 isolates (5.6%). Of all the isolated A. baumannii, 49 (71%) were found to be resistant to cephalosporins by screening tests and among them 27 isolates (39%) were found to be ESBL producing.Our study showed a high frequency of A. baumannii bacteremia occurrence in our hospital ICUs. An urgent intervention is needed to reduce the MDR bacterial load in these critical units.

Key words: Acinetobacter baumannii, bacteremia, multi-drug resistant, extended-spectrum beta-lactamase.