The Mosaic mtr Locus as Major Genetic Determinant of Azithromycin Resistance of Neisseria gonorrhoeae-Germany, 2018

J Infect Dis. 2021 Oct 28;224(8):1398-1404. doi: 10.1093/infdis/jiab091.


Within the German Gonococcal Resistance Network's (GORENET) Neisseria gonorrhoeae (NG) sample collection, azithromycin-resistant NG isolates increased from 4.3% in 2016 to 9.2% in 2018. We aim to understand this observed increase using whole genome sequencing of NG isolates combined with epidemiological and clinical data. Reduced susceptibility to azithromycin in 2018 was predominately clonal (NG multiantigen sequence typing G12302) and could mainly be attributed to the recently described mosaic-like mtr locus. Our data suggest that, together with horizontal gene transfer of resistance determinants and well-established point mutations, international spread of resistant lineages plays a major role regarding azithromycin resistance in Germany.

Keywords: Neisseria gonorrhoeae; Germany; MLST ST9363; NG-MAST ST12302; antibiotic resistance; azithromycin; genomic epidemiology; gonorrhea; macrolide; mosaic mtr locus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / genetics*
  • Anti-Bacterial Agents / pharmacology*
  • Anti-Bacterial Agents / therapeutic use
  • Azithromycin / pharmacology*
  • Drug Resistance, Bacterial / drug effects
  • Drug Resistance, Bacterial / genetics*
  • Germany / epidemiology
  • Gonorrhea / drug therapy*
  • Gonorrhea / epidemiology
  • Humans
  • Microbial Sensitivity Tests
  • Neisseria gonorrhoeae / drug effects*
  • Neisseria gonorrhoeae / genetics*
  • Neisseria gonorrhoeae / isolation & purification
  • Phylogeny
  • Whole Genome Sequencing


  • Anti-Bacterial Agents
  • Azithromycin
  • 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase
  • MTR protein, human