Enhanced molecular surveillance for gonococcal resistance during doxycycline post-exposure prophylaxis implementation
Ziyuan Zhao1, Leshan Xiu2, Junping Peng1
1NHC Key Laboratory of Systems Biology of Pathogens, National Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, PR China; Key Laboratory of Respiratory Disease Pathogenomics, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China; Key Laboratory of Pathogen Infection Prevention and Control (Ministry of Education), State Key Laboratory of Respiratory Health and Multimorbidity, National Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, PR China.
Objective:
The introduction of doxycycline post-exposure prophylaxis (doxy-PEP) as a strategy to reduce the risk of bacterial sexually transmitted infections has raised concerns about the potential for rapid selection of tetracycline resistance and the emergence of ceftriaxone-resistant strains. This study aimed to develop a molecular surveillance method to monitor antimicrobial resistance (AMR) in Neisseria gonorrhoeae (NG) during doxy-PEP implementation.
Methods:
We developed a high-resolution melting (HRM) analysis-based molecular assay, termed HRM-doxyPEP, to enhance surveillance of NG AMR. Validation was conducted with strains of known susceptibility profiles, and further evaluation was performed on clinical samples, comparing HRM results with quantitative PCR, whole-genome sequencing, and PCR-sequencing.
Results:
The HRM-doxyPEP assay demonstrated high analytical specificity and a detection limit of 20 copies/reaction, enabling the detection of low levels of target DNA in clinical samples. Validation with strains of known susceptibility profiles showed 84% consistency with antimicrobial susceptibility testing results. Clinical sample testing revealed 100% sensitivity and specificity for identifying NG infection, tracking ceftriaxone-resistant FC428-like strains, and detecting tetM associated with tetracycline resistance.
Conclusions:
The HRM-doxyPEP assay offers an accurate, affordable, and scalable tool for enhanced molecular surveillance of AMR in NG during doxy-PEP implementation.
