A polyclonal outbreak of predominantly VanB vancomycin-resistant enterococci in northeast Ohio

We studied the molecular epidemiology of vancomycin-resistant enterococci ( VRE) isolated in northeast Ohio during 1996 and examined the association be tween isolation of VRE from samples other than stool and antimicrobial purc hases for five Cleveland hospitals. Susceptibility testing and pulsed-field gel electrophoresis were used to analyze 363 isolates from individual pati ents from 13 hospitals. Susceptibility testing indicated that 287 strains ( 79%) expressed the VanB phenotype and 76 (21%) expressed the VanA phenotype . The outbreak was polyclonal, with 30 total genotypes. Both VanA and VanB VRE demonstrated multiple genotypes. One genotype was present in all hospit als, suggesting spread between hospitals. For five teaching hospitals, rate s of isolation from non-stool sources and from blood correlated positively with purchases of ticarcillin/clavulanic acid (P = .005). In summary, this outbreak demonstrates transmission of VRE between several hospitals in a ge ographic region and suggests that use of certain p-lactam antibiotics may b e associated with an increased prevalence of VRE.