The novel 2024 WHO Neisseria gonorrhoeae reference strains for global quality assurance of laboratory investigations and superseded WHO N. gonorrhoeae reference strains: Phenotypic, genetic and reference genome characterisation
MDR and XDR Neisseria gonorrhoeae strains remain public health concerns internationally, and a quality-assured global gonococcal AMR surveillance is imperative. The WHO global Gonococcal Antimicrobial Surveillance Programme (GASP) and WHO Enhanced GASP (EGASP), including metadata and WGS, are expanded internationally. We present the phenotypic, genetic and reference genome characteristics of the 2024 WHO gonococcal reference strains (n=15) for quality assurance worldwide. All superseded WHO gonococcal reference strains (n=14) were identically characterized.The 2024 WHO reference strains constitute 11 of the 2016 WHO reference strains (n=14), which were further characterized, and four novel strains. The superseded WHO reference strains (n=14) include 11 not previously published WHO reference strains. All strains were characterised phenotypically and genomically (using single-molecule PacBio and Illumina sequencing).The WHO reference strains represent all available susceptible and resistant phenotypes and genotypes for antimicrobials currently and previously used (n=22), or considered for future use (n=3) in gonorrhoea treatment. The novel WHO 2024 strains represent internationally-spreading ceftriaxone resistance, ceftriaxone resistance due to new penA mutations, ceftriaxone plus high-level azithromycin resistance, and azithromycin resistance due to mosaic MtrRCDE efflux pump. AMR, serogroup, prolyliminopeptidase, molecular AMR determinants, plasmid types, molecular epidemiological types, and reference genome characteristics were presented for all strains.The 2024 WHO gonococcal reference strains are recommended for internal and external quality assurance in laboratory examinations, especially in the WHO GASP, EGASP, and other GASPs, but also in phenotypic and molecular diagnostics, AMR prediction, pharmacodynamics, epidemiology, research, and as complete reference genomes in WGS analysis.