Multiplex High-Resolution Melting Assay for Simultaneous Identification of Molecular Markers Associated with Extended-Spectrum Cephalosporins and Azithromycin Resistance in Neisseria gonorrhoeae

J Mol Diagn. 2020 Nov;22(11):1344-1355. doi: 10.1016/j.jmoldx.2020.08.003. Epub 2020 Aug 17.

Abstract

Antimicrobial resistance in Neisseria gonorrhoeae persists as a major public health concern globally. We developed and evaluated a multiplex assay that relied on high-resolution melting (HRM) technology as a rapid, simple, and cost-effective method for simultaneously detecting and identifying different molecular markers associated with extended-spectrum cephalosporins (ESCs) and azithromycin (AZM) resistance in N. gonorrhoeae. Forty-eight well-characterized N. gonorrhoeae clinical isolates were selected for initial assay establishment. The multiplex HRM assays were able to accurately identify different nucleotide variations of the antimicrobial resistance determinants related to ESCs and AZM resistance. Specificity and cross-reactivity were assessed by testing 15 nongonococcal strains. Then, the assay was validated on 218 archived DNA specimens that had been sequenced using whole-genome sequencing technology. Compared with whole-genome sequencing, these assays had a sensitivity of 98.6%, with a specificity of 99.2%. For further validation of the assay's performance, a total of 338 samples (156 clinical isolates and 182 clinical specimens) were screened using the multiplex HRM assay. The results showed good concordance with the results of PCR sequencing. Given its rapidity (within 90 minutes), ease of performing, and low cost (<$1.00 per sample), this method may be applied to large-scale epidemiologic programs for increasing surveillance of ESCs and AZM resistance in N. gonorrhoeae.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Azithromycin / pharmacology*
  • Cephalosporins / pharmacology*
  • Cost-Benefit Analysis
  • DNA Mutational Analysis / economics
  • DNA Mutational Analysis / methods*
  • DNA, Bacterial / genetics
  • DNA, Bacterial / isolation & purification
  • Data Accuracy
  • Drug Resistance, Bacterial / drug effects*
  • Drug Resistance, Bacterial / genetics*
  • Limit of Detection
  • Microbial Sensitivity Tests
  • Neisseria gonorrhoeae / drug effects*
  • Neisseria gonorrhoeae / genetics*
  • Neisseria gonorrhoeae / isolation & purification
  • Transition Temperature*
  • Whole Genome Sequencing / economics
  • Whole Genome Sequencing / methods

Substances

  • Anti-Bacterial Agents
  • Cephalosporins
  • DNA, Bacterial
  • Azithromycin