Diagnosis and Treatment of Mycoplasma Genitalium

Common bacteria linked to sexually transmitted infections

Mycoplasma genitalium (Mgen) is a type of bacteria that is sexually transmitted. It can cause vaginal itching, burning with urination, and bleeding of the skin around the vagina in women, and urethral discharge or arthritic symptoms in men.

Mgen is the cause of several types of infections, including forms of bacterial vaginosis (BV) and non-gonococcal urethritis (NGU).

It has also been associated with pelvic inflammatory disease (PID) and implicated in other infections once attributed to other bacteria.

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Mycoplasma Genitalium Symptoms

By and large, most cases of Mgen don't cause symptoms. If symptoms do appear, they are largely nonspecific and easily mistaken for other sexually transmitted infections (STIs) such as chlamydia and gonorrhea.

Mycoplasma genitalium symptoms also differ significantly in women and men.

Mgen Symptoms in Women
  • Vaginal itching


  • Burning with urination


  • Pain during intercourse


  • Bleeding between periods or after sex


  • With BV, a fishy odor after sex and changes in vaginal discharge


Mgen Symptoms in Men
  • Urethral discharge


  • Burning with urination


  • Pain and swelling of the joints (arthritis)


Mgen is the next most common cause of NGU in men behind chlamydia.

Diagnosis

The main barrier to diagnosing Mgen is that there is no approved blood test to confirm infection. Direct diagnosis requires a bacterial culture—when a sample of bacteria is taken and grown in a lab—which takes up to six months to complete.

Instead, a nucleic acid amplification test (NAAT) is preferred. A NAAT uses urine and swab samples from the urethra, opening of the penis, part of the cervix, or vagina, and produces results in 24 to 48 hours.

If a NAAT is unavailable at a certain clinic, a healthcare provider might go ahead and diagnose Mycoplasma genitalium simply based on the fact that urethritis or cervicitis is persistent or recurrent. Studies show that 40% of such cases in men and up to 30% in women are caused by Mgen.

Role in Guiding Treatment

Syndromic treatment is when all STD cases that fit a certain profile of symptoms are treated the same without knowing their actual cause.

Healthcare providers who diagnose Mycoplasma genitalium based on symptoms alone and treat it accordingly may be right, but not always. That means that some people may have an entirely different infection that warrants an entirely different treatment. Had the infection been confidently identified from the start, they could have started on the correct medication sooner.

NAAT is, therefore, the recommended testing method to diagnose a suspected case of Mgen. Your doctor can make specific treatment choices based on the results, rather than trying something out based on an educated assumption.

Treatment

Mycoplasma genitalium is typically treated with antibiotics.

In the past, the most common form of treatment was a single 1-gram (g) dose of azithromycin. But evidence has shown increased resistance to azithromycin in populations where it's used broadly. That means that the bacteria has mutated so that this drug is no longer effective.

Today, Mgen from a patient is tested to see whether or not the bacteria has mutated into a variant that is resistant to azithromycin. Results of that testing dictate the recommended treatment:

  • Mgen has not mutated: 100 milligrams (mg) of doxycycline two times a day for seven days, followed by an initial 1 g dose of azithromycin, then 500 mg of azithromycin daily for the next three days
  • Mgen has mutated: 100 mg of doxycycline two times a day for seven days, followed by 400 mg of moxifloxacin once daily for seven days
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4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Keane FE, Thomas BJ, Whitaker L, Renton A, Taylor-robinson D. An association between non-gonococcal urethritis and bacterial vaginosis and the implications for patients and their sexual partners. Genitourin Med. 1997;73(5):373-7.

  2. Horner PJ, Martin DH. Mycoplasma genitalium Infection in MenJ Infect Dis. 2017;216(suppl_2):S396-S405. doi:10.1093/infdis/jix145

  3. Centers for Disease Control and Prevention. Sexually transmitted infections treatment guidelines, 2021. Updated June 23, 2021.

  4. Bradshaw CS, Jensen JS, Tabrizi SN, et al. Azithromycin failure in Mycoplasma genitalium urethritis. Emerging Infect Dis. 2006;12(7):1149-52. doi:10.3201/eid1207.051558

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