STD Awareness: Mycoplasma genitalium

“I’m not small, I’m just streamlined!” Image of Mycoplasma genitalium adapted from American Society for Microbiology.

In November and December of last year, headlines touting a “new” STD made an ever-so-minor flurry across the Internet. CNN referred to it as “mycoplasma genitalium, or MG” — Mycoplasma genitalium is the name of the teardrop-shaped bacteria that can cause several diseases in the urinary or reproductive tracts, such as urethritis and pelvic inflammatory disease.

M. genitalium is the smallest living organism known to science, having “devolved” from more complex organisms — but that doesn’t mean it can’t pack a punch! While these bacteria have surely been around for millennia, we only discovered them in the 1980s. Since then, we’ve known that M. genitalium fits the profile of a sexually transmitted pathogen — the only reason it made the news last year was that a team of British researchers published further evidence that this bug is indeed sexually transmitted and capable of causing disease.


Genital mycoplasmas can be cured — but a doctor needs to know what she’s looking for in order to prescribe the correct antibiotic!


An infection with M. genitalium could more generally be called a “genital mycoplasma.” The term “genital mycoplasmas” refers to a category of several different species of sexually transmitted bacteria, most notably Mycoplasma genitalium, but also less common species, such as Mycoplasma hominis, Ureaplasma urealyticum, and Ureaplasma parvum. M. genitalium is considered an “emerging pathogen,” because it is only over the past couple of decades that technology has allowed us to study these bacteria, along with other genital mycoplasmas.

Risk factors for infection include multiple sexual partners and not using condoms during sex. It is thought that most people with an M. genitalium infection don’t have immediate symptoms — 94 percent of infected men and 56 percent of infected women won’t notice anything amiss. That doesn’t mean it can’t do damage.

M. genitalium can cause urethritis (inflammation of the urethra) in the male population. Urethritis is characterized by discharge, difficult or painful urination, or itching — classic symptoms of many STDs. Urethritis can be caused by several types of microorganisms, most commonly manifesting as gonorrhea or chlamydia. However, it’s thought that M. genitalium is responsible for 30 percent of persistent or recurrent urethritis in males, and that it is more common than gonorrhea but not as common as chlamydia. What we don’t know is whether or not an infection with M. genitalium can have long-term consequences for males, such as infertility.

The havoc that M. genitalium might wreak on a female reproductive system was clarified last year, when a team of researchers published a meta-analysis of all the data published since 1980. They found that M. genitalium was significantly associated with several gynecological problems:

  • cervicitis (inflammation of the cervix): Cervicitis can make vaginal intercourse painful, and can cause vaginal discharge or bleeding — in fact, the British team found that women infected with M. genitalium were six times more likely to bleed after vaginal intercourse than uninfected sexually active women. M. genitalium occurs in up to 30 percent of women diagnosed with cervicitis.
  • pelvic inflammatory disease (PID): Infection with M. genitalium more than doubles one’s risk for pelvic inflammatory disease, or PID, which can lead to infertility, chronic pelvic pain, and increased risk for ectopic pregnancy. While PID is usually caused by gonorrhea or chlamydia, M. genitalium occurs in up to 22 percent of PID cases. There is also some evidence that M. hominis can cause PID as well.
  • preterm birth (also called premature birth): Infection with M. genitalium nearly doubles the risk for preterm birth, in which a baby is born before a pregnancy has reached 37 weeks. Because the last few weeks of pregnancy are so crucial to a baby’s development, being born too early can lead to death or disabilities, such as breathing, vision, or hearing problems, as well as cerebral palsy and developmental delays.
  • miscarriage: M. genitalium infection also increases risk for miscarriage, which is the loss of a pregnancy in the first 20 weeks.

How is M. genitalium diagnosed? While there are tests for M. genitalium, so far, none of them has been approved by the FDA. However, it seems probable that an M. genitalium test will be approved by FDA in the future, making it easier to confirm this bacteria as the cause of a patient’s symptoms and enabling proper treatment.

What is proper treatment, though? More testing needs to be done, but at this time it seems that moxifloxacin is the most effective cure for M. genitalium — but without good diagnostic tests, many doctors might not know to prescribe it. Instead, a health care provider might treat an infection based on symptoms. But, although genital mycoplasma symptoms might mimic those of gonorrhea, treatment with ceftriaxone (the recommended treatment for gonorrhea) won’t have any effect on M. genitalium. Ceftriaxone kills the bacteria that cause gonorrhea by destroying their cell walls — but M. genitalium doesn’t even have a cell wall!

Genital mycoplasma symptoms might also be confused with chlamydia, and drugs that cure chlamydia might kill M. genitalium as well. Azithromycin, which is the drug of choice for chlamydia, is thought to be reasonably effective against genital mycoplasmas, but it also seems that M. genitalium‘s resistance to this drug is on the rise, as cure rates have declined from 85 to 40 percent. Doxycycline, which is also given to cure chlamydia, only cures M. genitalium in 31 percent of cases.

If you have any of the symptoms discussed in this article, you can be tested for STDs at any Planned Parenthood health center. Because the CDC doesn’t have guidelines for screening M. genitalium, and because there is no FDA-approved test, PPAZ does not screen for it as part of their routine STD testing practices. However, if a patient has recurring symptoms that are suggestive of an M. genitalium infection, we might be able to identify it by a culture. We can also treat for M. genitalium empirically — i.e., based on symptoms — which is standard practice for many types of infections. You can also drop by to pick up condoms, which offer great protection against STDs like M. genitalium.


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4 thoughts on “STD Awareness: Mycoplasma genitalium

  1. Hi, i am here to seek for help.
    I am an Malaysian which suffer from MG from july 2015. GP gave me AZITHROMYCIN and DOXYCYCLIN when i complained for my symthoms, nothing went better.GP ask me to stop medicine and monitor. Greyish discharge still persist for few month. Until Jan 2016, an Infection Specialist did me STI 7 PCR TEST on my 1st catch urine in the morning, finally it showed that i have MG. Had MOXIFLOXAXIN for 9 days, repeated PCR URINE on 30,60,90 days after MOVI, the result came back NEGATIVELY but i complain that my testis is still feeling uncomfortable even my discharge has compleately went away. So DR sent to to a UROLOGIST, we did a 4 GLASS TEST, he massaged my prostate for about 10minutes long before took my urine,then the pcr on the urine still tested negatively on MG. Urologist said that my prostate is fine,
    i stopped seeing him for few weeks and i went back to him last week due to testis symthom persisted,he do ultra sound on my bladder, prostate, kidneys, testis ,said they are looking good.
    He said that may be my nerves were damaged by MG and these are the side effects after the infection is cured.
    I asked him if i need to do PCR on my sperm specimen and he answered that he believed the result will be negative too.

    I WANNA ASK,

    1, Is the PCR result is accurate which means my prostate is no more infection when the specimen tested is URINE AFTER MASSAGED PROSTATE?

    2, Do i need to do any PCR test on my sperm ?

    3, why do i still suffer symthom of testical pain ,(very minor feeling)?

    URGENT,my 1st baby is dynosed with PURE RED CELL APLASIA so that we are planning to have 2nd baby and hope the chord blood is match and can do bone marraw transplant.

    my wife is pregnant now,
    25april,a gynae took her vaginal specimen to test on MG after 5days of we had intercourse (20 APRIL) last month, the result showed negative. I request the DR did so due to i am very very worry about her even she were tested negatively before we intercoursed and no any synthom felt.

    CAN SAY THAT ME and MY WIFE ARE FREE FROM MG NOW?
    or my wife is tested too early?

    i still have very minor uncomfortable feeling ,
    what should i do next?
    please help,please!
    THANKS

    • Thank you for your inquiry. We are not able to provide specific medical advice on our blog. I recommend making an appointment with a medical professional to discuss your concerns. Be sure to bring in the questions you’ve asked here so you don’t forget to ask them. Good luck!

  2. The former Soviet medical field is way ahead on this one. Ureaplasma sterilizes males. Getting rid of it requires Avelox, Doxy and metroizoles (sic) taken together or back to back for a month with interferon shots and antiinflammatory suppositories. Nonsense to put someone on Doxy for 7 days and retest. Nuke it the Russian way as described above. Both partners must do this simultaneously.

    • How much interferon? What’s the dose…currently i’m fighting bacterial prostatitis wich i got after Non Specific Urethritis. Bacteria that infected me (Mycoplasma, Ureasplasma) is now in my prostate. I’m starting Azithromycin and Doxy…and i was thinking getting some interferon shots. Also if you can give some advice about azithromycin? ignorant urologists don’t believe in it…they only prescribed me doxy. i was thinking 1g of Azi per week for a month…this treatment is also used for first stage lyme. full doxy and from time to time azi 1g. Any reply will be appreciated, Gabe

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