title: Evaluation of vancomycin resistance 3 multiplexed PCR assay for detection of vancomycin-resistant enterococci from rectal swabs.
abstract: BACKGROUND
  Active screening for vancomycin-resistant enterococci (VRE) using rectal specimens is recommended to limit the spread of antimicrobial resistance within certain high-risk populations. We evaluated the diagnostic performance of Vancomycin Resistance 3 Multiplexed Tandem PCR assay (AusDiagnostics, Australia), a rapid multiplex real-time PCR assay that detects vanA and/or vanB.
  
  
  METHODS
  Two-hundred-and-eleven rectal swabs from Hematology and Oncology unit were submitted for VRE surveillance via direct detection of vanA and/or vanB by culture and by using Vancomycin Resistance 3 Multiplexed Tandem PCR assay. Enterococci were identified to the species level by using standard biochemical tests and BD Phoenix Automated Microbiology System (BD Diagnostic Systems, USA). Vancomycin susceptibility of enterococci was determined using Etest (BioMerieux, France).
  
  
  RESULTS
  Compared to the culture method, Vancomycin Resistance 3 Multiplexed Tandem PCR assay had a sensitivity of 84.0%, specificity of 98.8%, positive predictive value (PPV) of 91.3%, and negative predictive value (NPV) of 97.6%. The assay failed to detect 18 (8.5%) specimens because of the presence of PCR inhibitors; of the remaining 193 specimens, 25 (12.9%) were positive, 23 for vanA, and 2 for vanB. Although both sensitivity and specificity for vanA VRE was 100% compared to the culture method, all vanB-positive specimens tested negative by VRE culture.
  
  
  CONCLUSIONS
  Vancomycin Resistance 3 Multiplexed Tandem PCR assay is a rapid and laborsaving option for VRE surveillance for direct use on rectal swabs. However, the high rate of PCR failure owing to the inhibitors in the specimens and the low specificity for vanB should be considered when interpreting the results.
authors.affiliation: Clinical Microbiology, Antalya Research and Training Hospital, Antalya, Turkey.
authors.forename: Yesim
authors.initials: Y
authors.lastname: Cekin
authors.forename: Aylin
authors.initials: A
authors.lastname: Erman Daloğlu
authors.forename: Dilara
authors.initials: D
authors.lastname: Oğünç
authors.forename: Betil
authors.initials: B
authors.lastname: Ozhak Baysan
authors.forename: Duygu
authors.initials: D
authors.lastname: Dağlar
authors.forename: Dilara
authors.initials: D
authors.lastname: Inan
authors.forename: Derya
authors.initials: D
authors.lastname: Mutlu
authors.forename: Gözde
authors.initials: G
authors.lastname: Ongüt
authors.forename: Dilek
authors.initials: D
authors.lastname: Colak
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D019729:Carbon-Oxygen Ligases / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis*; D016983:Enterococcus / Q000187:drug effects* / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D006801:Humans; D060885:Multiplex Polymerase Chain Reaction; D011933:Reagent Kits, Diagnostic; D012007:Rectum / Q000382:microbiology*; D012680:Sensitivity and Specificity; D014640:Vancomycin / Q000494:pharmacology*; D020713:Vancomycin Resistance / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011933:Reagent Kits, Diagnostic; C071437:VanA ligase, Bacteria; C079913:VanB protein, Enterococcus; D014640:Vancomycin; D019729:Carbon-Oxygen Ligases
keywords: Enterococcus faecium; PCR; Vancomycin resistance