In 1996, the dominant (43%) strain of @entity2176 -resistant enterococci (VRE; type A) at Massachusetts General Hospital was identified at Brigham and @entity1 's Hospital (BWH). To characterize the epidemiology of @entity281 with type A isolates of VRE at BWH, we collected demographic and clinical data for all @entity1 from whom VRE were isolated from a clinical specimen through September 1996. The first clinical isolates from all BWH @entity1 from whom VRE were isolated were typed by pulsed-field gel electrophoresis of SmaI digests of chromosomal DNA. Among @entity1 hospitalized after the first @entity1 at BWH infected with a type A isolate of VRE was identified, exposures were compared between @entity1 who acquired type A isolates of VRE and those who acquired other types of VRE. Isolates from 99 @entity1 identified to have acquired VRE were most commonly from blood (n = 27), urine (n = 19), or wounds (n = 19). Three months after the index @entity1 arrived at BWH and at a time when > or =12 types of strains of VRE were present, type A isolates of VRE became dominant; 39 of 75 (52%) of the study cohort had acquired type A isolates of VRE. We found no association between the acquisition of type A isolates of VRE and transfer from another institution or temporal overlap by service, ward, or floor with @entity1 known to have acquired type A isolates of VRE. By multivariate analysis, only residence in the medical intensive care unit (adjusted odds ratio [OR], 3.2; 95% confidence interval [CI], 1.4 to 107) and the receipt of two or more antibiotics per @entity1 -day (adjusted OR, 12.2; 95% CI, 1.2 to 9.0) were associated with the acquisition of strain A. This strain of VRE, dominant at two Boston hospitals, was associated with intensity of antibiotic exposures (i.e., two or more antibiotics per @entity1 -day). We hypothesize that this strain may have unidentified properties providing a mechanism favoring its spread and dominance over other extant isolates, and further studies are needed to define these properties.

Epidemiology of a dominant clonal strain of XXXX -resistant Enterococcus faecium at separate hospitals in Boston, Massachusetts.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient', 'Women'] @entity281 :: ('MESH:D007239', 'Disease') :: ['infection'] @entity2176 :: ('MESH:D014640', 'Chemical') :: ['vancomycin']
@entity2176 :: (MESH:D014640,Chemical) :: ['vancomycin']
