Genetic relatedness of Vancomycin-Resistant Enterococci Isolated from Clinical Specimens

Jung, Sook In; Bae, Mun Hee; Park, Joong Il; Kim, Shin Woo; Lee, Hyuck; Kim, Sungmin; Peck, Kyong Ran; Lee, Jang Ho; Lee, Nam Yong; Song, Jae Hoon

Abstract

BACKGROUND
Vancomycin-resistant enterococci (VRE) infection has become one of the important nosocomial infections in the United States. Recently, increasing number of patients with VRE infection have been reported in Korea. We performed this study to investigate the clinical manifestations, genetic relatedness and mechanism of transmission of VRE in our hospital.
METHODS
We retrospectively reviewed the medical records of patients with VRE which were isolated from clinical specimens in Samsung Medical Center from July 1997 through September 1997. The minimal inhibitory concentrations (MIC, microgram/mL) of vancomycin and teicoplanin were determined by the agar dilution method. As for VRE isolated, PCR and pulsed-field gel electrophoresis (PFGE) for molecular epidemiologic analysis were performed.
RESULTS
During the study period, 5 strains of VRE were isolated from clinical specimens. All of 5 strains belonged to VanA phenotypically and genotypically. Among the five strains, one was E. faecalis and four were E. faecium. Four strains of E. faecium showed the same PFGE pattern.
CONCLUSION
This study demonstrated the unexpectedly high rate of VRE isolates during relatively short-term period. Four out of 5 strains of VRE had the same PFGE patterns, which suggested the possibility of dissemination of one clone. To prevent the emergence and spread of VRE, practical guidelines including restriction of vancomycin usage and surveillance are warranted.