Molecular Epidemiologic Analysis of vanA-Containing Vancomycin-Resistant Enterococci.
- Author:
Ji Young HUH
1
;
Wee Gyo LEE
Author Information
1. Department of Clinical Pathology, Ajou University of Medicine, Suwon, Korea. weegyo@ajou.madang.ac.kr
- Publication Type:Original Article
- Keywords:
VanA VRE;
Tn1546;
Horizontal transfer;
Long PCR-RFLP
- MeSH:
Agar;
Ampicillin;
Centers for Disease Control and Prevention (U.S.);
Electrophoresis, Gel, Pulsed-Field;
Furosemide;
Humans;
Infection Control;
Molecular Typing;
Polymerase Chain Reaction;
Polymorphism, Restriction Fragment Length;
Teicoplanin;
Tissue Donors;
Vancomycin
- From:The Korean Journal of Laboratory Medicine
2002;22(3):181-187
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Vancomycin-resistant enterococci (VRE) have been increasingly isolated world-wide as a nosocomial pathogen. To target infection control, epidemiologic investigations of VRE should include analysis of the resistance gene in addition to typing of strains. We performed molec-ular characterization of the vanA resistance gene to evaluate the inter or intraconstitutional spread. METHODS: Twenty isolates of VanA VRE from the Centers for Disease Control and Prevention (CDC) and 17 from Ajou University Hospital (AUH) were investigated. Minimum inhibitory concen-trations of vancomycin, teicoplanin, and ampicillin were tested by the agar dilution method. Pulsed-field gel electrophoresis (PFGE) and long PCR-restriction fragment length polymorphism (long PCR-RFLP) were performed. The long PCR negative strains were typed by ORF1-, vanS-vanH-, vanX-, vanY-vanZ-, vanZ-, and IS1216-specific PCRs. Filter matings were performed by using rifampin-resistant, fusidic acid-resistant E. faecalis J H2-2 as the recipient. RESULTS: The PFGE from the VRE of the CDC showed 15 patterns including 4 clusters and PFGE from isolates of AUH revealed 6 patterns including 3 clusters. Tn1546 amplicons were detected in 18 of 20 (90%) CDC strains and 16 of 17 (94%) AUH strains. RFLP of Tn1546 amplicons revealed 5 different patterns in the VRE of the CDC strains, and 2 patterns in the VRE of the AUH strains. The mean transfer efficiency of the CDC and the AUH strains are 3.0 X 10(-8)and 4.9 X 10(-5)transconju-gant/ donor, respectively. CONCLUSIONS: Molecular typing of isolates from the CDC suggests the horizontal spread of vanA genes among genetically diverse strains. Analysis of the VRE from the AUH shows a mixed pattern with clonal dissemination of strains and horizontal transfer of vanA.
