Changing resistance pattern for Acinetobacter baumannii through the years

Introduction

Over the past two decades, Acinetobacter baumannii has emerged as an important nosocomial pathogen, and hospital outbreaks caused by this organism have increased worldwide. Its extraordinary ability to acquire resistance to almost all groups of commercially available antibiotics is a clinical problem of great concern. In fact, most A. baumannii strains isolated in the ICU are highly resistant to carbapenems, aminogylcosides and β-lactam antibiotics. The aim of this study is to determine the change in the resistance pattern of A. baumannii through the years.

Methods

Isolates from patients admitted to the ICU in 2003 and 2007 were analyzed. Both colonization and infection isolates were evaluated. In 2003, 118 isolates from 51 patients and in 2007, 108 isolates from 21 patients were included in the study. The clinical specimens were sampled from the tracheal aspirate, abscess, blood, wound, urine, pleura fluid, catheter and ascites. Susceptibilities to seven antibiotics were determined.

Results

Patterns of resistance in 2003 and 2007 were: 54.7%/28.6% sulbactam–cefoperazone, 66.1%/85.7% imipenem, 96.6%/95.2% piperacillin–tazobactam, 66.1%/61.9% cefepime, 4.3%/0% colistin, 76.3%/85% amikacin, and 60.2%/66% tobramycin, respectively. Even though tobramycin is not on the market in Turkey, drug resistance has been increased in 4 years.

Conclusion

Colistin seems to be the best alternative in our hospital but, since it is not on the market in our country, the use of it is limited. Carbepenems are therefore the first choice in the treatment of multidrug-resistant A. baumannii in our country. This choice causes increased carbepenem resistance in A. baumannii isolates. Our hospital's antibiotic treatment policies and the cyclic usage of antibiotics must be reconsidered.