{
  "abstract": "Objectives The presence of gonococcal strains carrying the penA-60.001 allele has been reported worldwide. These strains can be resistant to ceftriaxone (CRO), which often leads to treatment failure. However, this strain has not been reported in Japan since 2017; therefore, its recent spread is not understood. Here, we report the emergence of CRO-resistant Neisseria gonorrhoeae and the strain carrying the penA-60.001 allele in Japan in recent years.Methods N. gonorrhoeae strains were identified during routine surveillance in the Kyoto–Osaka area of Japan between 2018 and 2024. Antimicrobial susceptibility testing was performed using the agar dilution method. Whole-genome sequencing (WGS) was performed using the MiSeq platform. A phylogenetic tree was constructed based on the core genome using IQ-TREE V.2.0.0, with the best-fit nucleotide substitution model being selected using the Bayesian information criterion. Transformation experiments were conducted to confirm that the gDNA of the CRO-resistant strain of N. gonorrhoeae could generate a new CRO-resistant strain.Results Of the 1336 N. gonorrhoeae strains isolated in this study, 6 were resistant to CRO. WGS revealed that one of these CRO-resistant N. gonorrhoeae strains, IW642, exhibited multilocus sequence type (MLST) 9903. It also carried the penA-60.001. A similarity analysis of the penA-murE regions of IW642 and FC428 revealed complete sequence identity in the penA region. Through transformation experiments, we also demonstrated the ability of IW642 gDNA to produce new CRO-resistant strains of N. gonorrhoeae.Conclusions An N. gonorrhoeae strain carrying the penA-60.001 allele was identified in Japan again, after not being reported since 2017. Based on a phylogenetic analysis, the strain originated from a different lineage than that of the previously dominant MLST 1903 strain in Japan. Transformation studies showed that new CRO-resistant N. gonorrhoeae strains could emerge from the gDNA of the MLST 9903 strain that was isolated.",
  "authors": [
    {
      "affiliations": [
        "National Institute of Infectious Diseases, Japan Institute for Health Security, Tokyo, Japan"
      ],
      "name": "Ken Shimuta"
    },
    {
      "affiliations": [
        "National Institute of Infectious Diseases, Japan Institute for Health Security, Tokyo, Japan"
      ],
      "name": "Yuki Ohama"
    },
    {
      "affiliations": [
        "National Institute of Infectious Diseases, Japan Institute for Health Security, Tokyo, Japan"
      ],
      "name": "Ai Yoshida"
    },
    {
      "affiliations": [
        "National Institute of Infectious Diseases, Japan Institute for Health Security, Tokyo, Japan"
      ],
      "name": "Shu-ichi Nakayama"
    },
    {
      "affiliations": [
        "National Institute of Infectious Diseases, Japan Institute for Health Security, Tokyo, Japan",
        "Okinawa Prefectural Institute of Health and Environment, Okinawa, Japan"
      ],
      "name": "Makoto Ohnishi"
    },
    {
      "affiliations": [
        "Osaka Institute of Public Health, Osaka, Japan"
      ],
      "name": "Takuya Kawahata"
    },
    {
      "affiliations": [
        "National Institute of Infectious Diseases, Japan Institute for Health Security, Tokyo, Japan"
      ],
      "name": "Hideyuki Takahashi"
    },
    {
      "affiliations": [
        "National Institute of Infectious Diseases, Japan Institute for Health Security, Tokyo, Japan"
      ],
      "name": "Yukihiro Akeda"
    },
    {
      "affiliations": [],
      "name": "Antibiotic-Resistant Gonorrhea Study Group"
    }
  ],
  "title": "Emergence of a ceftriaxone-resistant Neisseria gonorrhoeae strain harbouring penA-60.001 in a novel genetic background (MLST 9903) in Japan, 2018–2024",
  "uid": "fefa6107-3d26-53ae-bde4-d767705e8604"
}