This page is general health information, not medical advice. It cannot tell you whether you have an infection. A clinician can, and the testing options on this site are a good place to start.

Mycoplasma genitalium is a sexually transmitted bacterium that many people have never heard of. It is not part of the usual STI panel. It can be hard to treat. It also causes few or no noticeable problems in many people.

This guide covers what the organism is, what the research suggests about it, when CDC recommends testing, and how treatment decisions are made. It also covers what San Antonio clinics publish about their testing. It is a science-focused deep dive, so the usual "ingredient" questions (composition, research, safety, quality) are adapted to a test and an organism.

What mycoplasma genitalium is

Mycoplasma genitalium (often shortened to M. genitalium or MG) is a very small bacterium. It lives on the surfaces of the urinary and genital tracts. The CDC STI Treatment Guidelines (2021) list it as a sexually transmitted infection that can be passed through genital contact.

Two features set it apart from better-known bacterial STIs such as chlamydia and gonorrhea.

It has no cell wall. Many common antibiotics work by attacking the cell wall, so they are not useful against this organism.
It grows very slowly in a lab. Standard culture is impractical, so detection relies on a molecular method called a nucleic acid amplification test (NAAT).

If you want to compare it with a more familiar infection, our guide to chlamydia symptoms, testing and treatment in San Antonio covers a bacterial STI that is on routine panels.

Mycoplasma genitalium symptoms

Many people with M. genitalium have no symptoms. When symptoms do occur, they overlap with other infections, which is why symptoms alone cannot identify the cause. Only a test can.

The CDC STI Treatment Guidelines (2021) link M. genitalium to these conditions:

Urethritis (inflammation of the urethra). It can cause discharge from the penis, burning or discomfort when urinating, or itching at the tip of the penis.
Cervicitis (inflammation of the cervix). It can cause unusual vaginal discharge or bleeding between periods or after sex, though many people notice nothing.
Pelvic inflammatory disease (PID). This is an infection of the upper reproductive tract. Symptoms can include lower abdominal pain, pain during sex or fever. CDC notes that M. genitalium has been found in some people with PID.

Rectal infection can also occur. It often causes no symptoms. These symptoms can come from many causes, including chlamydia, gonorrhea, trichomoniasis and non-infectious conditions. A clinician can sort out which is which.

Research findings: what studies observe

The science on M. genitalium is still developing. The points below are observations from research summarized by CDC, not final answers.

Research suggests a link to persistent urethritis. CDC reports that M. genitalium is found in a meaningful share of men with non-gonococcal urethritis, and more often in cases that return after treatment.
Studies observe an association with cervicitis and PID. The strength of the link is clearer for cervicitis than for some of the longer-term outcomes people ask about.
Observational data show antibiotic resistance is common and growing. CDC describes high and rising resistance to macrolide antibiotics. Resistance to fluoroquinolones has also been reported. This is the main reason testing matters for this infection.
Evidence on screening people without symptoms is limited. CDC's 2021 guidelines do not recommend routine screening of people who have no symptoms. Anyone with questions about their own situation can talk to a clinician.

CDC does not publish a window period for M. genitalium testing the way it does for HIV. A clinician can advise on timing after a possible exposure.

CDC's 2024 guidance on doxycycline post-exposure prophylaxis (doxy-PEP) addresses chlamydia, gonorrhea and syphilis. M. genitalium is not one of its prevention targets. People who use doxy-PEP can ask their prescriber how it fits with this infection.

When CDC recommends testing

The CDC STI Treatment Guidelines (2021) recommend testing for M. genitalium in specific situations rather than for everyone. These are the situations CDC names:

Persistent or recurrent urethritis. This means urethritis that continues or returns after treatment.
Persistent or recurrent cervicitis. This means cervicitis that continues or returns after treatment.
PID. CDC says testing can be considered for people being evaluated for pelvic inflammatory disease.
Partners of a person diagnosed with M. genitalium. CDC recommends that partners be evaluated and, where appropriate, tested and treated.

This list comes from a clinical guideline. A clinician decides whether it applies to you. If you are unsure, you can describe your symptoms and history and ask.

Why it is not on standard panels

A typical STI panel covers chlamydia, gonorrhea, syphilis and HIV, sometimes with hepatitis C or trichomoniasis. M. genitalium is usually left off for a few reasons:

CDC does not recommend routine screening of people without symptoms, so it is not a default test.
Testing is most useful when it can guide treatment, and that depends on the lab offering a test and, ideally, resistance testing.
CDC notes that an FDA-cleared NAAT exists, but access varies by lab and clinic.

In practice, a negative standard panel says nothing about M. genitalium, because it was not looked for. A clinician can tell you what a given panel covers.

How testing works

The test is a NAAT, which looks for the genetic material of the organism. According to CDC, the samples used can include:

First-catch urine, especially for people with a penis.
Vaginal swabs, which CDC describes as the preferred sample for people with a vagina. A clinician or the person being tested can collect them.
Urethral, cervical, or rectal swabs in some settings.

Some labs can also check the sample for genetic changes linked to macrolide resistance. That is called resistance testing, and CDC encourages it where it is available.

Resistance-guided treatment

Treatment is something a clinician prescribes. This page does not name doses or schedules.

The CDC STI Treatment Guidelines (2021) describe a resistance-guided approach. When a lab reports whether the organism carries macrolide resistance, the clinician picks the antibiotic sequence to match. When resistance testing is not available, CDC describes a different, more cautious sequence of antibiotics.

The reason is practical. Using the wrong antibiotic can fail to clear the infection, and repeated exposure to antibiotics may encourage more resistance. Bacterial STIs are curable with treatment from a clinician. M. genitalium can take more than one course, so follow-up with your clinician matters.

CDC does not recommend a routine test of cure for people whose symptoms have gone away after treatment. If symptoms continue, tell your clinician. CDC also advises avoiding sex until treatment is complete and symptoms have resolved, and that partners be evaluated.

Texas has no EPT statute. According to CDC's page on the legal status of expedited partner therapy (EPT) in Texas, state administrative rules let physicians and advanced practice nurses prescribe STD medication for partners of an established patient. Pharmacists may dispense it. A clinician can say whether this applies to your situation.

Safety profile and contraindications

For the test itself, there are no known medical contraindications. A urine or swab sample is low risk. People who are pregnant, have recent antibiotic use, or have allergies should tell the clinician, since those details affect which treatment is chosen.

For treatment, the safety questions belong to the prescriber. Antibiotic choice depends on allergies, pregnancy, other medicines and resistance results. Do not use leftover medicine or a partner's prescription. Tell the clinician about any reaction.

Privacy and consent matter, too. Under Texas Family Code Sec. 32.003, a minor of any age may consent to diagnosis and treatment of a reportable infectious disease, so parental consent is not required. The same section allows a physician to tell a parent or guardian about the treatment. A provider is permitted, not required, to do so. Ask about confidentiality before your visit if that concerns you.

On the legal side, the CDC's 2023 analysis of HIV and STD criminalization laws lists Texas as having no HIV-specific or STD-specific criminal exposure law. General criminal laws can still apply. For legal questions, a lawyer or a clinic counselor is the right person to ask.

Quality indicators: what to look for in a test

A "good" test here is not about brands. It is about whether the result can guide care. Useful questions to ask a clinic:

Is the test an FDA-cleared NAAT? CDC points to NAAT as the method for detection.
Does the lab report macrolide resistance? Resistance results are what make resistance-guided treatment possible.
Who explains the result? A clinician should explain what a positive or negative means for you and what comes next.
What happens if it is positive? Ask about treatment, follow-up and partner care.

M. genitalium testing in San Antonio

Here is the plain answer: none of the San Antonio clinic pages we reviewed say they test for M. genitalium. Their published test lists name other infections. That does not mean a clinic cannot order it. It means you should ask before you go. Call the clinic, say you are asking about a M. genitalium test, and ask whether they run it or can refer you.

Texas DSHS lists chlamydia, gonorrhea, syphilis, chancroid, HIV and AIDS among the notifiable infections in its 2026 list. It does not name M. genitalium, so there are no local case counts to share. For context on nearby infections, Texas DSHS's 2022 STD Surveillance Report counted 12,305 chlamydia cases and 5,983 gonorrhea cases in Bexar County (gonorrhea rate 290.5 per 100,000).

What the clinics publish

Metro Health STI Walk-In Clinic (San Antonio Metropolitan Health District), 512 E. Highland, Suite 150, 210-207-8830. It offers STI and HIV testing, treatment and counseling. Metro Health lists a $15 office visit administrative fee, with other fees varying by service. Hours are Monday to Thursday 7:45 a.m. to 4:30 p.m. (latest check-in 3 p.m.) and Friday 7:45 a.m. to 12 p.m. (latest check-in 10:30 a.m.). Check-in may close early at capacity. A photo ID is required, and testing is not anonymous. The clinic serves residents of San Antonio and Bexar County and people with no other way to get STI services.
San Antonio AIDS Foundation, 818 E. Grayson Street, (210) 225-4715. Its testing page lists rapid HIV, syphilis, gonorrhea and chlamydia testing, free of charge, with no appointment needed. It lists gonorrhea and chlamydia results in 7 to 10 days.
Alamo Area Resource Center, 303 N. Frio, (210) 625-7200. It lists free testing for HIV, hepatitis C, syphilis, gonorrhea and chlamydia, with walk-ins Monday to Friday 8 a.m. to 4:30 p.m. and Wednesday until 8 p.m.
Kind Clinic, 730 Isom Road. It lists HIV and STI testing, STI treatment and free walk-in testing. Its general support line is 833-937-5463, and walk-in hours differ from clinic hours, so confirm before you go.
CommuniCare Apollo Wellness Clinic, 6511 W Loop 1604 N, Ste. 105, (726) 224-3438, open Monday to Friday 8 a.m. to 5 p.m. CommuniCare lists a sliding fee discount for self-pay patients with family income under 200% of federal poverty guidelines.

You can see the full list of local options on our San Antonio clinic list, and our guide to where to get STD testing in San Antonio explains what a routine visit usually covers.

CDC also runs a testing locator at gettested.cdc.gov. Enter your ZIP code to see nearby sites, then call to ask about M. genitalium.

A calm way to approach the conversation

If you have symptoms that came back after treatment, or a partner has been diagnosed, you do not need to know the answer ahead of time. You can say what you notice, what treatment you have had, and that you would like to ask about M. genitalium. Clinicians hear these questions often, and nobody needs to be judged for asking.

Mycoplasma Genitalium: What It Is and Where to Get Tested in San Antonio