OUTBREAK OF MULTIDRUG-RESISTANT ENTEROCOCCUS-FAECIUM WITH TRANSFERABLE VANB CLASS VANCOMYCIN RESISTANCE

Enterococcus faecium strains resistant to ampicillin, high levels of g entamicin, and vancomycin but susceptible to teicoplanin (vanB class v ancomycin resistance) were recovered from 37 patients during an outbre ak involving a 250-bed university-affiliated hospital. Three isolates with vancomycin MICs ranging from 8 to 256 mu g/ml all hybridized with a vanB probe. Restriction endonuclease analysis of chromosomal and pl asmid DNA suggested that all isolates tested were derived from a singl e clone. Vancomycin resistance was shown to be transferable. Risk fact ors for acquiring the epidemic strain included proximity to another ca se patient (P, 0.0005) and exposure to a nurse who cared for another c ase patient (P, 0.007). Contamination of the environment by the epidem ic strain occurred significantly more often when case patients had dia rrhea (P, 0.001). Placing patients in private rooms and requiring the use of gowns as,veil as gloves by personnel controlled the outbreak Th ese findings suggest that multidrug-resistant E. faecium strains with transferable vanB class vancomycin resistance will emerge as important nosocomial pathogens. Because extensive environmental contamination m ay occur when affected patients develop diarrhea, barrier precautions, including the use of both gowns and gloves, should be implemented is soon as these pathogens are encountered.