Impact of Chlamydia trachomatis treatment with azithromycin or doxycycline on Mycoplasma genitalium in women.

OBJECTIVES

In women being screened for Chlamydia trachomatis (CT) infection, Mycoplasma genitalium (MG) testing is not recommended. Among women positive for CT, studies reported that 7% to 28% had concurrent urogenital MG. The aim of this study was to investigate the impact on MG of a single 1-g dose of azithromycin or a 7-day course of doxycycline regimens as part of CT treatment.

METHODS

MG was tested in vaginal swabs from the Chlazidoxy cohort collected at baseline and the 6-week follow-up visit after CT treatment. MG genotype and antibiotic resistance were analysed by sequencing the mgpB gene, and the parC, 23S and 16S rRNA genes.

RESULTS

Among the 281 women included, 131 received azithromycin and 150 doxycycline. The proportion of MG-positive women was 16% (21/131) in the azithromycin group, and 12% (18/150) in the doxycycline group (P = 0.39). In each group, a similar proportion of macrolide (11.1% vs 26.7%, P = 0.37), and quinolone (11.7% vs 16.7%, P = 1) resistance-associated mutations were detected. Six weeks after treatment initiation, azithromycin eradicated MG in 85.7% (18/21) of the cases and doxycycline in 55.6% (10/18) (P = 0.07).

CONCLUSION

In asymptomatic women infected with CT, the treatment with azithromycin or doxycycline eradicated MG in the majority of the cases.