# P-715. Trends in Mycoplasma genitalium Resistance from 2019 to 2024 in Tokyo, Japan

## TL;DR

This study tracks resistance trends in Mycoplasma genitalium in Tokyo from 2019 to 2024, finding high macrolide resistance and increasing parC mutations.

## Contribution

The study provides updated data on resistance mutations in Mycoplasma genitalium in Tokyo over a five-year period.

## Key findings

- MRMs were present in 89.9% of isolates, with A2071T and A2072G being the most common.
- ParC mutations increased from 56% in 2019 to 100% in 2024, though not statistically significant in early versus late periods.
- GyrA mutations remained stable at around 24% across the study period.

## Abstract

Mycoplasma genitalium (MG) is a major cause of urethritis in men and cervicitis or pelvic inflammatory disease in women, and the infection has been linked to adverse reproductive outcomes. We examined trends in macrolide- and quinolone-resistance mutations in MG isolates in Tokyo.

Between 1 January 2019 and 31 December 2024, we prospectively enrolled patients with MG-positive urine or anal-swab specimens at the National Center for Global Health and Medicine. Sanger sequencing detected macrolide-resistance mutations (MRMs) in domain V of 23S rRNA and quinolone-resistance mutations in the quinolone-resistance-determining regions of parC and gyrA. Temporal trends were assessed with χ² or Fisher’s exact tests, and linear change was evaluated with a Cochran–Armitage trend test. Results for an early period (2019–2020) were compared with those for a later period (2021–2024).

Among 216 MG infections (165 anal, 51 urine), sequencing succeeded for 168 isolates at 23S rRNA, 154 at parC, and 149 at gyrA (success rates 77.8 %, 71.3 %, and 69.0 %, respectively). MRMs occurred in 151/168 isolates (89.9 %): A2071T in 44.0 %, A2072G in 31.0 %, and A2071G in 13.1 %. MRM prevalence did not change significantly over time (p = 0.700). ParC mutations were present in 123/154 isolates (79.9 %) and increased from 56 % (14/25) in 2019 to 100 % (8/8) in 2024 (Cochran–Armitage p = 0.006); however, the early- versus late-period comparison showed no significant difference (71.2 % vs 83.3 %, p = 0.078). S83I (G248T) was the most frequent parC mutation, found in 74.7 % (115/154) of sequenced isolates, and its proportion remained stable (p = 0.133). Mutations in gyrA were detected in 36/149 isolates (24.2 %), mainly M95I (17.4 %); their frequency was unchanged over the study period (31 % in 2019 vs 25 % in 2024, p = 0.821). Resistance rates did not differ significantly between urine and anal samples.

MG strains circulating in Tokyo show persistently high macrolide resistance and an upward trend in parC mutation, whereas gyrA mutations remain comparatively stable. These findings highlight the need for sustained molecular surveillance, rigorous antimicrobial stewardship, and the development of novel therapeutic options for MG infection.

All Authors: No reported disclosures