Changes in prevalence of Mycoplasma genitalium macrolide and fluoroquinolone resistance: notes from a 13-year retrospective survey in Dalarna County, Sweden

Sex Transm Infect. 2023 Dec;99(8):507-512. doi: 10.1136/sextrans-2023-055900. Epub 2023 Sep 13.

Abstract

Objective: Macrolide and fluoroquinolone resistance in Mycoplasma genitalium (MG) is of emerging global concern. Compared with neighbouring countries such as Denmark, Sweden has had lower rates of macrolide resistance while fluoroquinolone resistance rates are less well documented. This study retrospectively examined macrolide, fluoroquinolone and multidrug resistance rates from Dalarna County, Sweden over a 13-year period.

Methods: MG-positive samples from 2006 to 2018 from patients examined at the Department of Venereology, Central Hospital, Falun, Sweden were tested by sequencing for macrolide resistance mutations (MRM) and fluoroquinolone resistance-associated mutations (QRAM) in the parC and gyrA subunit regions. A subset of these samples from 2006 to 2011 have been reported on previously, although only for MRM.

Results: Of 874 samples, 98 (11.2%, 95% CI 9.1% to 13.6%) had mutations associated with resistance to macrolides and 19 of 828 (2.3%, 95% CI 8.9% to 23.1%) to quinolones. Mutations associated with resistance to both drugs were detected in 5 of 828 (0.6%, 95% CI 0.1% to 1.4%) samples overall. A significant positive linear trend (p=0.004) for an increase in the rate of macrolide resistance was observed (from 0% in 2006 to 31% in 2018) while the increase in QRAM from 0% in 2006 to 12.3% in 2018 was not statistically significant.

Conclusions: Despite a decrease in macrolide and fluoroquinolone consumption in Sweden, there was an overall increase in MG macrolide, fluoroquinolone and dual resistance from 2006 to 2018, although the difference in fluoroquinolone resistance rates was not statistically significant. In order to maintain comparably low resistance rates, resistance-guided therapy for MG infections will be crucial.

Keywords: Mycoplasma genitalium; azithromycin; drug resistance, bacterial; resistance.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Anti-Bacterial Agents / therapeutic use
  • Drug Resistance, Bacterial / genetics
  • Fluoroquinolones / pharmacology
  • Fluoroquinolones / therapeutic use
  • Humans
  • Macrolides / pharmacology
  • Macrolides / therapeutic use
  • Mycoplasma Infections* / drug therapy
  • Mycoplasma Infections* / epidemiology
  • Mycoplasma genitalium* / genetics
  • Prevalence
  • RNA, Ribosomal, 23S / genetics
  • Retrospective Studies
  • Sweden / epidemiology

Substances

  • Anti-Bacterial Agents
  • Fluoroquinolones
  • Macrolides
  • RNA, Ribosomal, 23S