Epidemiology and antimicrobial resistance of Mycoplasma genitalium among female sex workers in China: a cross-sectional study.

BACKGROUND

Mycoplasma genitalium (MG) is an important sexually transmitted pathogen associated with cervicitis, pelvic inflammatory disease and adverse reproductive outcomes. Female sex workers (FSWs) are at elevated risk; however, data on MG epidemiology and antimicrobial resistance in this population in China remain limited. This study assessed the prevalence of MG infection, associated risk factors and resistance-related mutations among FSWs.

METHODS

This cross-sectional study was conducted from April to August 2022 in four cities in Guangdong Province. FSWs were recruited through venue-based outreach. Participants completed structured questionnaires covering sociodemographic characteristics and sexual behaviors. Urine and blood samples were collected for laboratory confirmation of MG, Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum and HIV. MG-positive specimens were subjected to Sanger sequencing to detect macrolide resistance mutations in the 23S rRNA gene, and fluoroquinolone resistance mutations in the gyrA and parC genes. Logistic regression analyses were used to identify factors associated with MG infection.

RESULTS

Among 955 FSWs, the prevalence of MG was 6.6%, whereas the prevalences of C. trachomatis, N. gonorrhoeae, T. pallidum and HIV were 14.0%, 1.7%, 1.4% and 0.1%, respectively. Multivariate logistic regression analysis revealed higher odds of MG infection among women with monthly income ≤3000 RMB (aOR 2.61, 95% CI: 1.08-6.31), primary school education or below (aOR 2.87, 95% CI: 1.12-7.37), work in mid-level venues (aOR 2.64, 95% CI: 1.37-5.09) and C. trachomatis co-infection (aOR 3.30, 95% CI: 1.81-6.01). Among MG-positive samples with successful amplification, macrolide resistance-associated mutations in the 23S rRNA gene were detected in 70.27% (26/37). Fluoroquinolone resistance-associated mutations were identified in 78.95% (30/38) of amplifiable parC samples and in only one amplifiable gyrA sample. The S83I substitution in parC was the most prevalent, accounting for 66.67% (20/30) of parC mutations. Dual resistance-conferring mutations in both macrolide (23S rRNA) and fluoroquinolone (parC) targets were observed in 51.35% (19/37) of samples.

CONCLUSION

MG infection persists at a relatively high level among FSWs, accompanied by alarmingly high rates of macrolide and fluoroquinolone resistance mutations. These findings highlight the urgent need for strengthened surveillance, improved access to molecular diagnostics, and tailored prevention and treatment strategies to curb MG transmission and preserve antimicrobial efficacy in this high-risk population.