Epidemiology and Molecular Characterization of Vancomycin-Resistant Enterococcus faecalis.
- Author:
Joon KIM
1
;
Kyung Ho CHOI
;
Young Sun KIM
;
Wee Gyo LEE
Author Information
- Publication Type:Original Article
- Keywords: IS1216V; IS1542; Tn1546; Vancomycin-resistant Enterococcus faecalis
- MeSH: Classification; DNA Transposable Elements; Electrophoresis, Gel, Pulsed-Field; Enterococcus faecalis*; Enterococcus faecium; Enterococcus*; Epidemiology*; Genotype; Humans; Korea; Polymerase Chain Reaction
- From:Annals of Clinical Microbiology 2015;18(3):76-81
- CountryRepublic of Korea
- Language:Korean
- Abstract: BACKGROUND: Vancomycin-resistant Enterococci (VRE) infections are caused by Enterococcus faecium in about 90% of the cases but can also be caused by Enterococcus faecalis. Thus, this study investigates factors that cause a low isolation rate of vancomycin-resistant E. faecalis (VREfs). To this end, the authors study the clinical traits, resistant gene structure, genomic classification, and molecular characteristics of the virulent factor. METHODS: From January 2001 through September 2011, 17 vanA-containing E. faecalis isolates were collected from hospitalized patients at Ajou University Hospital in Korea. Identification, antimicrobial susceptibility testing, and PCR of van and esp genes were performed. Pulsed-field gel electrophoresis (PFGE) was used for strain typing. PCR and sequencing of the internal regions of Tn1546 were performed for structural analysis of the van gene. RESULTS: Of 4,235 VRE infections, 3,918 (92.5%) were caused by E. faecium, and 95 (2.2%) were caused by E. faecalis. In 67% of VREfs infections, there was a preceding occurrence of E. faecium infection. All isolates were of genotype vanA. Our isolates were divided into three types according to the distribution of IS elements integrated into Tn1546 (types I to IIb). The PFGE results showed no clonal relatedness among isolates. CONCLUSION: Our study found that VREfs infections affect patients who have experienced vancomycin-resistant E. faecium. (VREfm) infection or undergo invasive procedures. The VREfs seems to involve the horizontal transfer of Tn1546 transposon from VREfm.
