Mycoplasma Genitalium Testing

Testing for Mycoplasma genitalium usually involves a first-catch urine sample or vaginal swab, depending on symptoms and anatomy.

In some situations, rectal swabs may also be recommended depending on sexual exposure and symptoms.

Samples are analysed using highly sensitive PCR (NAAT) technology to detect the genetic material (DNA) of Mycoplasma genitalium.

If providing a urine sample, you may be advised not to pass urine for 1–2 hours before testing, as this can improve accuracy.

Vaginal swab testing does not usually require any specific preparation.

No other special preparation is generally needed before testing.

Testing is generally most reliable around 2 weeks after potential exposure.

If you have symptoms or a partner has tested positive, earlier assessment may still be appropriate.

Testing too early after exposure may increase the chance of a false negative result.

Mycoplasma genitalium (Mgen) testing uses a Nucleic Acid Amplification Test (NAAT), also known as a PCR test, to detect the genetic material (DNA) of the bacteria.

Instead of trying to grow the bacteria in a laboratory, the test looks for small amounts of Mgen DNA in a urine sample or swab. The PCR process amplifies this genetic material, making it easier to detect even when only a very small amount of bacteria is present.

This method is highly sensitive and is considered the gold standard for diagnosing Mgen because the bacteria are difficult to grow using traditional laboratory methods.

Mycoplasma genitalium testing is highly accurate when performed using a NAAT (PCR) test, which detects the bacteria’s DNA.

Accuracy can vary depending on the sample type and timing of the test. First-catch urine samples are commonly used for men, while vaginal swabs are often preferred for women to improve detection.

For the most reliable result, it is usually best to wait at least 2 weeks after potential exposure before testing. Testing too early may increase the chance of a false negative result.

You should consider testing for Mycoplasma genitalium if you have symptoms such as unusual discharge, pain when passing urine, pelvic discomfort, or symptoms that continue after treatment for another STI.

Testing may also be recommended if:

• A sexual partner has tested positive for Mgen
• Symptoms persist despite negative tests for other infections
• You have ongoing symptoms after treatment for chlamydia or gonorrhoea

For the most accurate result, it is generally recommended to wait at least 2 weeks after a possible exposure before testing. Mgen is not always included in routine STI screening, so testing is usually based on symptoms, exposure risk, or clinical advice.

A physical examination may be offered if you are experiencing symptoms, particularly if there are concerns about complications or alternative diagnoses.

Any examination is optional, and your clinician will explain the reasons for recommending it before proceeding.

Yes. While Mycoplasma genitalium testing is usually performed using a Nucleic Acid Amplification Test (NAAT) or PCR test, there are a few important differences in how testing may be carried out.

The main variation is the sample type used. For men, a first-catch urine sample is commonly used, while for women, a vaginal swab is often preferred as it may improve detection accuracy.

Some laboratories also offer antibiotic resistance testing alongside the standard test. This checks whether Mycoplasma genitalium may be resistant to certain antibiotics, particularly macrolides, which can help guide treatment choices.

Mycoplasma genitalium testing may be offered as:

• A standalone test for Mycoplasma genitalium
• Part of a broader STI screen, depending on symptoms and testing needs

Because Mycoplasma genitalium is not always included in routine STI testing, a dedicated test may be recommended if symptoms persist or other STI results are negative.

You can receive your test results by either text or email.

Results are usually reported as:

• NOT Detected — no Mycoplasma genitalium was identified in the sample tested
• DETECTED — Mycoplasma genitalium genetic material was identified in the sample

Occasionally, a result may be reported as equivocal or inconclusive, meaning the laboratory could not confirm a clear result from the sample provided. If this occurs, repeat testing may be recommended.

It is advisable to avoid sexual contact or use condoms consistently while waiting for your results, particularly if you have symptoms or a recent exposure.

Your clinician may recommend additional precautions depending on your symptoms, treatment status, or exposure history.

If your result is positive, treatment and follow-up advice can be arranged through our clinic.

Your clinician will advise on the most appropriate antibiotic treatment, any recommended follow-up testing, and whether partner management is advised.

In some cases, medication collection or postal treatment options may be available depending on your clinical situation.

If you have already started treatment, it is important to follow the instructions provided by your clinician carefully.

It is essential to inform all sexual partners that you have tested positive for Mycoplasma genitalium so they can get tested and treated appropriately.

Yes. A certificate of testing can be provided for official purposes on request.

You may be asked to provide photographic identification, such as a passport or driving licence.