일개 대학병원에서 분리된 반코마이신내성 장구균의 분자역학적 분석

Abstract

Since the first report of vancomycin-resistant enterococci (VRE) in 1992; the prevalence of VRE in the hospitals has rapidly increased in Korea. VRE have emerged as a major cause of nosocomial infections. The aims of present study were to determine the prevalence of VRE; the genotype of VRE and to establish whether the isolates were clonally related. A total of 90 VRE isolates were collected from the patients admitted to Dongsan Medical Center from Jan to Dec; 2006. Species identification and genotyping were evaluated with multiplex polymerase chain reaction. Antimicrobial susceptibility test was determined by agar dilution methods according to Clinical and Laboratory Standards Institute (CLSI). Pulsed field gel electrophoresis (PFGE) with SmaI-restriction enzyme was also performed. The annual incidence of VRE was 16.2% in 2001; 19.4% in 2002; 16% in 2003; 23.7% in 2004; 24.7% in 2005 and 14.7% in 2006. VRE were identified as E. faecium and E. faecalis in 71 (78.9%) and 19 (21.1%) isolates; respectively. All VRE isolates were resistant to vancomycin. Only 75 VRE isolates were resistant to teicoplanin; and 15 VRE isolates were susceptible or intermediate to teicoplanin which were interpreted as VanB phenotypes. All VRE isolates carried the vanA gene. PFGE analysis showed that all 15 VRE. faecalis from the nursery showed same patterns. Our data indicate that the annual prevalence of VRE seems to decrease shortly but should surveil continuously afterward. VRE isolates of the nursery that showed same PFGE pattern is probably due to the spread of an endemic clone within the hospital. Therefore; further moleculoepidemiological evaluations would be needed prospectively.