Step aside, MRSA, here comes Acinetobacter.(Clinical Rounds)

WASHINGTON -- The United States may be poised on the brink of the next drug-resistant infection epidemic, with outbreaks of Acinetobacter baumannii already appearing in hospitals here, according to experts speaking at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

The spread of the bacteria has already reached epidemic proportions in Israeli and Latin American hospitals, and is a serious problem in Europe as well. In fact, "Acinetobacter has been designated as the gram-negative MRSA [methicillin-resistant Staphylococcus aureus]," said Dr. Harald Seifert, a professor at the University of Cologne's Institute of Medical Microbiology and Hygiene.

"We're not only dealing with an increasing incidence of multiresistant Acinetobacter, but we seem to be dealing with an increasing absolute incidence of Acinetobacter," said Dr. Anthony D. Harris, an epidemiologist for the University of Maryland Medical System, Baltimore.

Acinetobacter baumannii is a nonmotile, gram-negative bacterium that affects mainly immunocompromised patients, particularly patients in the ICU setting or those who have been hospitalized for long periods, Dr. Seifert said at the meeting sponsored by the American Society for Microbiology. The organism can cause a wide range of infections, but the most common are respiratory tract, bloodstream, urinary tract, skin and soft tissue, and wound infections.

About half of Acinetobacter infections are sepsis- or ventilator-associated pneumonias, based on data from several series, said Dr. Yehuda Carmeli, head of the division of epidemiology at the Tel Aviv Sourasky Medical Center. Central nervous system infections after neurosurgery are also common.

Acinetobacter outbreaks also have occurred after man-made and natural disasters, and the U.S. military has reported an increasing number of Acinetobacter bloodstream infections in soldiers injured in Iraq, Kuwait, and Afghanistan.

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