FFinalistSouthampton · 2027
Sexual health
AKT · Sexual health/Bacterial STIslow yield

Mycoplasma genitalium

Mycoplasma genitalium — cell-wall-deficient

Overview

An increasingly recognised cause of non-gonococcal urethritis and cervicitis, with rising macrolide resistance; tested for when symptoms persist after doxycycline.

Recognise

  • Persistent/recurrent non-gonococcal urethritis or cervicitis
  • Often the cause when NGU fails to respond to doxycycline
  • Can cause PID

Red flags

  • Treatment failure; PID

Differentials & how to tell them apart

ChlamydiaNAAT distinguishes; M. genitalium suspected when chlamydia-negative NGU persists
GonorrhoeaGC NAAT/culture
Ureaplasmauncertain pathogenicity

Investigations

NAAT (where available) including a macrolide-resistance assay. Test in persistent NGU.

Management

Doxycycline 100 mg BD ×7d, then azithromycin 1 g then 500 mg OD ×2d

  1. 1Doxycycline 100 mg BD ×7d, then azithromycin (1 g then 500 mg OD ×2d) if macrolide-sensitive.Gate: If macrolide-resistant or treatment fails → moxifloxacin 400 mg OD ×7–14d
  2. 2Test of cure recommended (resistance).
Doxycycline then azithromycin — sequential (extended); doxy reduces load, azithromycin clears
Moxifloxacin — if macrolide-resistant or failed

Key points

Do not test asymptomatic people without symptoms/contact. Macrolide resistance is common — guided therapy.

Monitor & prognosis

Test of cure; symptom resolution.

Good with appropriate therapy.

Source: BASHH M. genitalium guideline