Mycoplasma Genitalium: Transmission, Symptoms, Testing and Treatment

Mycoplasma Genitalium - STDTestGuru
Mycoplasma Genitalium – STDTestGuru

Mycoplasma Genitalium or MG is a bacterium that lives on the skin cells of the urinary and genital tracts and can affect both men and women. MG is passed from person to person through bodily fluids. It can be penile-vaginal sex or penile-anal sex. Transmission via oral sex is likely to be rare. It can affect the cervix urethra, rectum, and, rarely, the throat. Mycoplasma genitalium (MG) is less prevalent than chlamydia trachomatis and more prevalent than Neisseria gonorrhoeae and it is strongly associated with sexual activity.

Specimens were tested for Mycoplasma Genitalium and Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis from 946 subjects seeking care from seven geographically diverse clinical sites. And it was identified that the prevalence rate of M. genitalium was 16.1% for females and 17.2% for males.

What is Mycoplasma?

Mycoplasmas are bacteria and are considered to be the smallest known forms of living microbes currently identified by scientists. They can affect various parts of the body which include lungs, urinary tract, or skin depends on which type of mycoplasma bacteria is causing the infection. There are almost 200 types of mycoplasma bacteria, and most of them are harmless. But there are few specific forms that can cause infections and serious health concerns:

  • Mycoplasma pneumoniae – This bacteria lives in the respiratory system and causes lung infections.
  • Mycoplasma genitalium– This bacteria lives in and around the urinary tract and genitals
  • Mycoplasma hominis – This bacteria affect women and live in a women’s reproductive system and in the urinary tract.
  • Ureaplasma urealyticum and Ureaplasma parvum – Both the bacteria live in the urethra of men and the cervix or vagina of women. Mostly, all healthy adults have this bacteria, but if it leads to an infection, it can create health problems.

What is Mycoplasma genitalium?

Mycoplasma genitalium is also called Mgen or M. genitalium. Transmission occurs when a person has sex with a person who already has the infection. It is caused by a tiny bacterium called Mycoplasma genitalium. According to a recent study, more than 1 in 100 adults might have Mgen. Mycoplasma and chlamydia have many similarities, both infect individuals through unprotected sexual intercourse. And often have similar symptoms, but especially in mycoplasma genitalium, it is common for no symptoms to occur at all. But there are only limited antibiotics to treat it, because of a quirk in its cellular structure and the growing threat of antibiotic resistance. The infection rate is higher among people who have multiple sexual partners or do not practice safe sex.

Mycoplasma genitalium transmission

Mgen is passed from person to person through bodily fluids. It is transmitted via genital-to-genital contact like vaginal or anal sex. And might occur even without penetration. Usually, it is passed directly from an infected area but can sometimes be passed on through infected fluid on fingers and sex toys. Transmission through oral sex is rare. And it cannot spread by kissing, hugging, sharing baths or towels, using swimming pools, or from toilet seats.

Who is at risk?

  • People who have unprotected vaginal, anal, and oral sex
  • Genital to genital contact (not necessarily penetration)
  • Having a partner who has Mycoplasma Genitalium
  • People who have more sexual partners
  • People who have or already had another STI
  • Smokers
Mycoplasma Genitalium: Causes and Symptoms
Mycoplasma Genitalium: Causes and Symptoms


Infected people may not experience symptoms. And it is estimated that 7 or 8 out of every 10 infected men, and a half to three-quarters of infected women do not have symptoms. When symptoms occur, it appears 1-3 weeks after initial infection. MG or Mgen is the common cause of nongonococcal urethritis in males and pelvic inflammatory disease in females.

Mycoplasma genitalium symptoms in men

  • Urethritis
  • Pain on ejaculation
  • Watery and cloudy discharge from the tip of the penis
  • Proctitis
  • Inflammation of the foreskin and penis
  • Bacterial vaginosis

Mycoplasma genitalium symptoms in women

  • Urethritis
  • Increased or altered vaginal discharge
  • Vaginal itching
  • Bleeding between periods
  • Pain on intercourse
  • Discharge or bleeding after intercourse
  • Lower abdominal pain
  • Bacterial vaginosis

Symptoms like pain in passing urine, unusual discharge, and pelvic pain can also be symptoms of other STIs like chlamydia, gonorrhea, or trichomoniasis.

Mycoplasma genitalium testing

M. genitalium is an extremely slow-growing organism and it is not easy to detect or isolate. For direct diagnosis, it requires a bacterial culture, which takes up to six months to grow. But when doctors think he/she might have it, they can get a nucleic acid amplification test (NAAT). This test is FDA cleared for use with swab samples of urine, urethral, penile meatal, endocervical, and vaginal. Laboratories also test mycoplasma genitalium for antibiotic resistance in order to decide which treatment to use. It is essential to avoid sexual contact until you have been retested to check if you have been cured.

Who should get tested?

  • Men with non-gonococcal urethritis
  • Women with pelvic inflammatory disease
  • Having sexual partners infected with mycoplasma Genitalium
  • Any men or women with symptoms

Mycoplasma genitalium treatment

M. genitalium can be tricky to treat. Usually, antibiotics (like penicillin) kill bacteria by damaging a germ’s cell walls. But Mycoplasma genitalium bacteria don’t have cell walls, so these drugs are ineffective against this organism. This condition is typically treated with antibiotics like azithromycin (Zithromax, Zmax). Azithromycin is considered to be effective and safe, and there is evidence of increasing resistance to the drug in populations where it’s used broadly. If this doesn’t work, doctors might give moxifloxacin (Avelox). According to some studies, an extended course of moxifloxacin has been very effective. But shorter courses are ineffective. Doctors may also treat the other conditions M. genitalium can cause, that include PID, urethritis, or cervicitis.

Sex partners of the infected people should talk to their doctors about getting tested and treated if necessary. So, they don’t infect other people. One can get MG again even when they’ve already had treatment for it.

Is Mycoplasma genitalium curable?

MG can be cured by effective treatment, but people do not develop any immunity. So, it is possible to get the infection again. It usually takes 7 to 10 days for mycoplasma genitalium to go away but in some serious cases, it takes more than 35 days to get rid of it.


When left untreated, it can cause similar complications to chlamydia.

  • Pelvic inflammatory disease – Infection and inflammation in the womb and Fallopian tubes. Pelvic inflammatory disease can make it hard to get pregnant. Women may experience abdominal pain and pain on intercourse, a raised temperature.
  • Epididymo-orchitis may occur in men, this condition is painful swelling and infection of the testicle.
  • An inflamed cervix – cervicitis.
  • When a person has other sexually transmitted infections like human immunodeficiency virus (HIV), having Mgen as well makes them more likely to pass on those other infections.
  • A condition that makes the urethra irritated, swollen, and itchy, called urethritis. This condition can happen to both men and women.
  • Sexually acquired reactive arthritis can occur as a reaction to urethritis in men and women.
    It can also weaken the immune system makes the infected person becomes more susceptible to other infections. And there is a chance that internal organs may also get infected.


  • Practice safer sex
  • All sexual partners need to be tested and treated, if necessary
  • Testing for other sexually transmitted infections
  • Avoid sex until antibiotic treatment is completed
  • A follow-up test is recommended to make sure that treatment has cleared the infection
Mycoplasma Genitalium Statistics
Mycoplasma Genitalium Statistics

Mycoplasma genitalium and Chlamydia

Both Mycoplasma genitalium and chlamydia have very similar symptoms, but it is caused by a different germ. And possible to have both infections. MG appears to be less common than chlamydia infection and also appears to be slightly less easily transmitted than chlamydia. But for MG, there are only limited antibiotics to treat it, because of a quirk in its cellular structure and the growing threat of antibiotic resistance.

A pregnant woman who is infected by MG may pass on the infection to their baby at the time of vaginal delivery. However, it is not clear whether it can be passed to the baby whilst in the womb and it is also unclear whether this would harm the baby. It is important to inform the clinic which is treating the infection as not all antibiotics used for Mgen are safe for use in pregnancy.


  • Miscarriage
  • Premature (early) birth
  • Infection in the uterus after birth

Facts about Mycoplasma genitalium

  • MG is associated with both urethritis and urethral inflammation and accounts for 15–25% of non-gonococcal urethritis (NGU)cases in the US.
  • It’s estimated that about 2% – 4% of the U.S. population has Mycoplasma genitalium.
  • According to community-based studies from the United Kingdom, United States, Australia, and Scandinavia the prevalence of MG infection is 1% to 3% in men and women.
  • Urine specimens of 1714 women and 1218 men were tested for M genitalium. And the prevalence of MG was 1.0% compared with 4.2%, 2.3%, and 0.4% for chlamydial, trichomonal and gonococcal, infections.
  • According to CDC, it is estimated that 10% to 30% of cervicitis cases and 15% to 30% of urethritis in men are caused by Mycoplasma genitalium.
  • Mycoplasma genitalium is responsible for 2% to 22% of PID (which may affect fertility in women).
  • MGen is present in 10% – 30% of women who are diagnosed with cervicitis.
  • As per CDC, more than 15% of male and female patients with nongonococcal STIs are at risk of acquiring MG.

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