title: Molecular epidemiology of vancomycin-resistant enterococci in  Singapore.
abstract: OBJECTIVE
  To characterise the mechanism of glycopeptide resistance, genetic relatedness, and pathogenicity factors in isolates of vancomycin-resistant enterococci (VRE) in Singapore.
  
  
  METHODS
  A total of 292 Enterococcus faecium and 17 Enterococcus faecalis were isolated from humans, and five E. faecium, two Enterococcus durans, two Enterococcus flavescens, one Enterococcus casseliflavus, and one Enterococcus gallinarum from chickens. The mechanism of glycopeptide resistance and pathogenicity factors were studied by PCR and the genetic relatedness determined by pulsed-field gel electrophoresis (PFGE), multi-locus variable number tandem repeat analysis (MLVA), and Tn1546 analysis.
  
  
  RESULTS
  There were five outbreak clones among the vancomycin-resistant E. faecium with one clone predominant. Four of the clones were vanB positive, and only one clone carried vanA. All outbreak clones were esp gene positive. Sporadic human isolates and chicken isolates were vanA positive and did not contain any pathogenicity genes. The situation was reversed in vancomycin-resistant E. faecalis where almost all isolates were vanA positive.
  
  
  CONCLUSIONS
  Most VRE in Singapore is hospital associated with a small number of clones of esp-positive vanB E. faecium responsible for the majority of isolates.
authors: Department of Pathology, Singapore General Hospital, Singapore. koh.tse.hsien@sgh.com.sg
authors: Tse H
authors: TH
authors: Koh
authors: Beng S
authors: BS
authors: Low
authors: Nicholas
authors: N
authors: Leo
authors: Li-Yang
authors: LY
authors: Hsu
authors: Raymond T P
authors: RT
authors: Lin
authors: Prabha
authors: P
authors: Krishnan
authors: Douglas
authors: D
authors: Chan
authors: Maheswari
authors: M
authors: Nadarajah
authors: Say L
authors: SL
authors: Toh
authors: Keng H
authors: KH
authors: Ong
mesh_terms: D000818:Animals; D002645:Chickens / Q000382:microbiology; D004196:Disease Outbreaks; D016983:Enterococcus / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D005798:Genes, Bacterial / Q000235:genetics*; D005838:Genotype; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D012846:Singapore / Q000453:epidemiology; D014640:Vancomycin / Q000494:pharmacology*; D020713:Vancomycin Resistance / Q000187:drug effects*
chemical_list: D014640:Vancomycin