Diversity of Mycoplasma genitalium strains in Australia: relationship with sexual networks and antimicrobial resistance.

Abstract

Purpose: Molecular typing can identify relationships between M. genitalium strains and antimicrobial resistance and demographic data. We examined the association of mgpB sequence types (STs) with sex/sexual orientation, antimicrobial resistance and geographical location for M. genitalium in Australia.

Methods: Sequence data derived from previous studies in Victoria and Queensland were obtained from 170 M. genitalium samples for the mgpB, 23 S rRNA, and parC genes. An additional 55 M. genitalium samples from Victoria were sequenced for the same three genes in this study. A combined data set of 225 samples collected between 2017 and 2019 were examined for associations between mgpB ST and (i) sex/sexual orientation, (ii) macrolide and fluoroquinolone resistance, and (iii) geographical location using chi-square test.

Results: Overall, 66 mgpB STs were identified; the most common were ST-7 (17.9%), ST-4 (11.6%), ST-105 (11.6%), and ST-2 (5.4%). There was a strong association between ST and sex/sexual orientation; ST-4 and ST-105 were most common among men-who-have-sex-with-men (p < 0.0001) while ST-7 among women (p < 0.0001). There was a strong association between ST and macrolide resistance (p = 0.0028). Fluoroquinolone resistance was less common (28.0%) and did not differ by STs (p = 0.20). There was no association between ST and geographic location (p = 0.056).

Conclusion: In this Australian study, four mgpB STs were common and were strongly associated with sex/sexual orientation and macrolide resistance. This relationship was not seen for fluoroquinolone resistance nor geographic location. These findings highlight the sporadic nature of resistance, indicating a need for effective treatment approaches combined with routine antimicrobial resistance surveillance.