Multicentre Clinical Evaluation of a Molecular Diagnostic Assay to Identify Neisseria gonorrhoeae Infection and Detect Antimicrobial Resistance.

OBJECTIVES: Antimicrobial resistance (AMR) in Neisseria gonorrhoeae is an urgent threat to public health, with the emergence of high-level resistant strains such as the FC428 clone. This study aimed to evaluate the high-resolution melting assay of N. gonorrhoeae AMR (HRM-NG-AMR) for diagnosing of N. gonorrhoeae infection and detecting extended-spectrum cephalosporins and azithromycin resistance.

METHODS: To evaluate the performance of the HRM-NG-AMR assay, we employed a multicentre collection of 1488 samples, including 770 isolates and 718 urogenital swabs. The presence of N. gonorrhoeae was confirmed by culture. Minimum inhibitory concentrations of antibiotics against the tested isolates were determined using the agar dilution method.

RESULTS: Regarding N. gonorrhoeae identification, HRM-NG-AMR had a sensitivity of 95.15% (95% confidence interval [CI], 91.65-97.28) and a specificity of 96.44% (95% CI, 94.17-97.89) using culture as a standard. Regarding AMR detection, the specificity ranged from 96.29% (95% CI, 94.57-97.50) for cefixime to 99.52% (95% CI, 98.68-99.85) for azithromycin. Additionally, the sensitivity ranged from 31.34% (95% CI, 20.87-43.97) for azithromycin to 79.10% (95% CI, 63.52-89.42) for ceftriaxone. We determined that 98.81% (664/672) and 91.52% (615/672) of N. gonorrhoeae isolates were susceptible to ceftriaxone and cefixime, respectively, by detecting non-mosaic penA. Lastly, 40 genotypic FC428-related strains with the penA-60.001 allele were accurately identified.

CONCLUSIONS: The HRM-NG-AMR assay showed promising diagnostic performance for detecting N. gonorrhoeae infection and predicting AMR. Study is being designed to evaluate the application of this assay in the clinical setting to enhance AMR surveillance and treatment intervention.