A novel molecular assay conducted on the BD Max system to facilitate reflex testing for vanA and vanB in clinical isolates of enterococci.

Item request has been placed! ×
Item request cannot be made. ×
loading   Processing Request
Read More Add to Saved list
  • Additional Information
    • Source:
      Publisher: Lippincott Williams & Wilkins Country of Publication: England NLM ID: 0175411 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1465-3931 (Electronic) Linking ISSN: 00313025 NLM ISO Abbreviation: Pathology Subsets: MEDLINE
    • Publication Information:
      Publication: Jan. 2011- : London : Lippincott Williams & Wilkins
      Original Publication: [Surry Hills, NSW, etc., Modern Medicine, etc.]
    • Subject Terms:
      Real-Time Polymerase Chain Reaction*/methods ; Carbon-Oxygen Ligases*/genetics ; Bacterial Proteins*/genetics ; Vancomycin-Resistant Enterococci*/isolation & purification ; Vancomycin-Resistant Enterococci*/genetics ; Sensitivity and Specificity*; Humans ; Gram-Positive Bacterial Infections/diagnosis ; Gram-Positive Bacterial Infections/microbiology ; Enterococcus/isolation & purification ; Enterococcus/genetics ; Vancomycin Resistance/genetics
    • Abstract:
      Infections caused by vancomycin-resistant enterococci (VRE) are common. Real-time PCR assays targeting vanA and vanB facilitate screening of patients in healthcare settings to limit the risk of dissemination, especially amongst those at high-risk of infection or with limited treatment options. Such assays are commonly performed as reflex testing procedures where they augment phenotypic techniques and shorten turnaround time to benefit timely clinical management. 'Random access' and 'sample-to-result' real-time PCR platforms are suited for this application as they are of low complexity and less technically demanding. Modelled on these attributes, we configured a real-time PCR assay (VRE BD) for detection of vanA/B in clinical isolates of enterococci, adapted for the BD Max System (Becton Dickinson). We applied an unconventional approach by testing suspensions of microorganisms in water to circumvent the traditional pre-analytical genomic extraction process. Our objective of this study was to assess the performance of this assay for detection of VRE in cultures by validating against a traditional real-time PCR assay based on the LightCycler 2.0 platform (Roche, VRE RO). A high level of analytical sensitivity and specificity (≥99.0%) for both genes was obtained when testing suspensions derived from blood agar. Results for suspensions obtained from chromID VRE (Edwards Group) showed a similar level of performance for vanA detection (100%), but not for the vanB target (≥90.9%) where a lesser number of isolates were available for testing. However, our results for VRE detection in isolates from these media were repeatable and reproducible, and equated to positive and negative predictive values of ≥95.2% and ≥97.8%, respectively. Furthermore, the VRE BD assay was also able to accurately detect VRE in clinical and spiked BacT/ALERT (bioMérieux) blood cultures. Thus, the technical simplicity, short turnaround time and robustness of this high performing assay for VRE is suitable for reflex testing. In addition, the format developed for the BD Max platform has potential application for reflex testing other molecular targets of clinical importance.
      (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
    • Contributed Indexing:
      Keywords: Real-time PCR testing; VRE; genomic extraction; reflex testing; validation
    • Accession Number:
      EC 6.1.- (Carbon-Oxygen Ligases)
      0 (Bacterial Proteins)
      0 (VanA ligase, Bacteria)
      0 (VanB protein, Enterococcus)
    • Publication Date:
      Date Created: 20240709 Date Completed: 20240902 Latest Revision: 20240910
    • Publication Date:
      20240910
    • Accession Number:
      10.1016/j.pathol.2024.04.005
    • Accession Number:
      38981818