Multidrug-resistant enterococci: a threat to the surgical patient.

The enterococcus has become an important nosocomial pathogen, reported by the National Nosocomial Infections Surveillance System as the third most common pathogen associated with blood-stream infections and the second most commonly isolated pathogen overall. It is now more frequently recognized as a cause of superinfection in the surgical patient, as the possible result of the frequent use of ineffective antimicrobials for prophylaxis and treatment. Both of these findings are due, in part, to the intrinsic antimicrobial resistance of the enterococci. Of greater concern is the ready ability of this organism to acquire resistance traits. During the past 5 years, the appearance and rapid dissemination of strains with high-level resistance to vancomycin, ampicillin, gentamicin, and streptomycin have been reported; in some cases, no effective antimicrobial therapy was available to patients infected with these strains. Enterococci, in addition to their intrinsic and acquired tolerance to beta-lactams, have acquired the ability to inactivate penicillin and ampicillin via beta-lactamase production. Prompt recognition of such multiresistant enterococci, the implementation of effective infection control precautions, and rational use of antimicrobials may limit or even prevent the spread of such strains in the hospital setting.