Treating multidrug-resistant Acinetobacter is a challenge.(Clinical Rounds)

WASHINGTON -- Multidrug resistance poses a serious problem for the treatment of Acinetobacter baumannii infections, and one expert offered his thoughts on the choice of therapy at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

"Most of the problems around the world are [Acinetobacter strains] that have become resistant to everything," said Dr. James J. Rahal, the director of the infectious disease section at New York Hospital Queens and a professor of medicine at Weill Medical College of Cornell University, New York.

The carbapenems and ampicillin-sulbactam have retained in vitro and clinical activities against Acinetobacter, but a growing number of reports have documented resistance to these drugs. Physicians have turned to nontraditional agents, such as colistin and polymyxin B, which had lost favor in the antibiotic arsenal because of concerns about nephrotoxicity.

Dr. Rahal offered this advice:

* Cephalosporins should probably be avoided for the treatment of Acinetobacter, with the possible exception of use in combination with an aminoglycoside.

* For susceptible Acinetobacter strains, trimethoprim-sulfamethoxazole, quinolones, and ampicillin-sulbactam may be effective as single therapies.

* Carbapenems remain the drugs of choice. It's unclear whether combination therapy with another drug might prevent the development of resistance to the carbapenems.