title: Effect of routine use of a multiplex PCR for detection of vanA- and vanB- mediated enterococcal resistance on accuracy, costs and earlier reporting.
abstract: A multiplex PCR (MPCR) for detection of vanA-and vanB-mediated resistance to vancomycin was optimized and adapted for use in the routine microbiology laboratory. Consecutive specimens (1196) submitted for vancomycin resistant Enterococci (VRE) surveillance were processed by clinical technologists on Bile Esculin Azide Agar containing 6 mg/L vancomycin (BEAA/Vanco6) plates and 466 showing black colony growth were processed by conventional biochemical testing (CBT) and by MPCR. CBT identified 208 VRE positives. MPCR detected 205 of the CBT- positives plus an additional 10. Analysis of the discordant specimens determined that 5 CBT- negative/MPCR-positive specimens also contained Enterococci with vanC resistance, 3 CBT-positive/MPCR-negative specimens were true positives, and 5 CBT-negative/MPCR-positive specimens occurred due to technical error. The sensitivity and specificity of MPCR were 98.4% and 96.1%. MPCR identifications of VRE were achieved approximately 48 h earlier than CBT and at 60% of the costs.
authors.affiliation: Hamilton Regional Laboratory Medicine Program, McMaster University, Hamilton, ON, Canada. petricha@mcmaster.ca
authors.forename: A
authors.initials: A
authors.lastname: Petrich
authors.forename: K
authors.initials: K
authors.lastname: Luinstra
authors.forename: B
authors.initials: B
authors.lastname: Page
authors.forename: S
authors.initials: S
authors.lastname: Callery
authors.forename: D
authors.initials: D
authors.lastname: Stevens
authors.forename: A
authors.initials: A
authors.lastname: Gafni
authors.forename: D
authors.initials: D
authors.lastname: Groves
authors.forename: M
authors.initials: M
authors.lastname: Chernesky
authors.forename: J B
authors.initials: JB
authors.lastname: Mahony
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D019729:Carbon-Oxygen Ligases / Q000235:genetics*; D003365:Costs and Cost Analysis; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016983:Enterococcus / Q000235:genetics; D006801:Humans; D016133:Polymerase Chain Reaction / Q000191:economics / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies
chemical_list: D001426:Bacterial Proteins; C071437:VanA ligase, Bacteria; C079913:VanB protein, Enterococcus; D019729:Carbon-Oxygen Ligases