Trend of Isolation and Genotypes of Vancomycin-esistant Enterococci Isolated from Tertiary Care Hospital in Wonju Area

Kwon, Oh Gun; Uh, Young; Jang, In Ho; Lee, Mi Kyung; Yoon, Kap Jun; Kim, Hyo Youl

Abstract

BACKGROUND: Vancomycin-esistant enterococci (VRE) were first recovered from clinical isolates in Korea in 1992, and the incidence has been steadily increasing. The goal of this study was to determine the isolation trend of VRE by year and genotypes of VRE isolated from clinical specimens in Wonju area.
METHODS
We investigated the patients' medical records to determine the incidence of VRE among enterococci isolated from 1995 to 1999 in Wonju Christian Hospital, performed antimicrobial susceptibility tests to vancomycin and teicoplanin by agar dilution methods, and genotyped them with multiplex polymerase chain reaction for 117 cryopreserved VRE isolates.
RESULTS
VRE were first isolated in December 1995. Overall incidence of VRE during the period of 1996 to 1999 was 6.1% (164/2,682). The annual incidence of VRE was 1.9% in 1996, 5.5% in 1997, 6.7% in 1998, and 9.7% in 1999. The species of VRE included 115 (69.7%) E. faecium, 11 (6.7%) E. faecalis, 17 (10.3%) E. casseliflavus, 10 (6.1%) E. gallinarum, and 12 (7.3%) Enterococcus species. Of 117 VRE, E. faecium and E. faecalis strains were phenotyped as VanA, and genotyped as vanA with the exception of five VRE which the genotypes were not identified. All E. gallinarum and E. casseliflavus strains were genotyped as vanC- and vanC-, respectively.
CONCLUSIONS
VRE were first isolated in 1995. And the isolation rate of VRE were increasing trend from 1.9% in 1996 and 9.7% in 1998. Most of VRE were E. faecium with vanA genotype.