Gardnerella Vaginalis: The Organism at the Centre of BV
Gardnerella vaginalis is the organism most closely tied to bacterial vaginosis. It is thought to start the sticky biofilm that lets other anaerobes move in, and it produces the thin discharge and fishy odour that bring most people in to get tested.
What is Gardnerella vaginalis?
Gardnerella vaginalis is a facultative anaerobic bacterium and the organism most strongly associated with bacterial vaginosis (BV).
The leading model of BV is that Gardnerella starts it. It attaches to the vaginal wall and forms a structured biofilm, a kind of bacterial scaffold, that other anaerobes such as Atopobium vaginae then attach to and grow within. As this community takes over from the protective Lactobacillus, the result is the thin grey discharge and fishy odour that characterise BV.
Gardnerella produces vaginolysin, a toxin that damages human cells, along with enzymes that break down the protective mucus layer. One nuance worth knowing: Gardnerella can also be found in women with no symptoms at all, so its presence is read alongside the rest of the picture rather than as a yes or no answer on its own. Recent work has also shown that what was long called a single species is in fact several closely related Gardnerella species with differing behaviour.
Why Gardnerella is the organism to identify
BV is not just uncomfortable. It is linked to higher risk of sexually transmitted infections including HIV, to pelvic inflammatory disease, and to complications in pregnancy. Pinning down whether Gardnerella is driving your symptoms matters for what happens next.
Starts the biofilm
It builds the scaffold that other BV organisms attach to, which is part of why BV is so prone to returning.
Causes the tell-tale signs
The thin discharge and fishy odour that bring most people in are largely down to Gardnerella and its partners.
Needs context to read
Because it can also appear without symptoms, a panel that measures it against your Lactobacillus is more useful than a single test.
What a Gardnerella result means
A high level of Gardnerella together with reduced protective Lactobacillus is a strong pointer to BV. Gardnerella on its own, in someone with healthy Lactobacillus and no symptoms, is less clear cut and may not need treatment. This is exactly why the balance matters more than any single organism.
A symptom or a swab under a microscope cannot tell you this. A PCR microbiome panel measures Gardnerella alongside your protective Lactobacillus and the other BV-associated organisms, so you can see whether your flora has genuinely tipped into BV, and what is driving it, rather than guessing.
This is particularly helpful if your infections keep returning, since the biofilm Gardnerella builds is one reason BV so often comes back after treatment.
The BV Microbiome Test
R1,609 17-target PCR panelEpicentre's BV Microbiome Test is a 17-target PCR panel that measures Gardnerella alongside your protective Lactobacillus and the other organisms that drive BV. No doctor's referral, and you collect the sample yourself in private.
- Protective Lactobacillus levels, including Gardnerella vaginalis, so you can see whether your defences are intact.
- BV-associated bacteria, such as Gardnerella vaginalis and Atopobium vaginae, the organisms that take over when Lactobacillus falls.
- Group B Streptococcus, which matters in pregnancy.
- You collect the swab yourself, in private, at a branch or at home, with guidance if you want it.
Testing for Gardnerella in South Africa
Bacterial vaginosis affects roughly a quarter of reproductive-age women worldwide, and recurrence is common. In South Africa, where BV is also linked to higher HIV risk, identifying the organisms behind your symptoms is worth doing accurately rather than by trial and error.
Find out why it returns
If BV keeps coming back after treatment, a panel shows which organisms are still present, which helps explain the pattern.
Name the cause
Discharge or odour that will not settle is worth identifying precisely rather than treating blind.
No referral, three cities
Walk in at Observatory in Cape Town, Hillcrest in Durban or Parktown North in Johannesburg, or test at home anywhere in South Africa.
Gardnerella is the name most people have heard, and for good reason: it tends to be the organism that gets BV started. But I always read it against the Lactobacillus, because Gardnerella on its own does not always tell the whole story.
What testing can and cannot tell you
A microbiome test maps which organisms are present and in what balance; it is not a diagnosis on its own.
- The result describes your vaginal flora at one point in time, which can shift with your cycle, sex, antibiotics and hormones.
- It does not replace a clinical assessment. Use it to inform a conversation with a healthcare practitioner.
- If you have severe pain, fever, or symptoms in pregnancy, seek medical care rather than waiting for a result.
- PCR results take 5 to 7 working days.
Gardnerella vaginalis: quick answers
Vaginal microbiome testing in Cape Town, Durban and Johannesburg
The BV Microbiome Test is available at all three Epicentre walk-in labs: Observatory in Cape Town, Hillcrest in Durban and Parktown North in Johannesburg. Walk in, or book online first. You collect the swab yourself, in private.
Other organisms in the panel
Sources
- Gardnerella vaginalis. StatPearls, NCBI Bookshelf. 2023.
- Fredricks DN et al. Molecular identification of bacteria associated with bacterial vaginosis. N Engl J Med. 2005.
- Coleman JS, Gaydos CA. Molecular diagnosis of bacterial vaginosis: an update. J Clin Microbiol. 2018.
- Shipitsyna E et al. Composition of the vaginal microbiota: sensitive and specific molecular diagnosis of BV. PMC. 2013.
Medically reviewed by Dr Samantha Naidoo, MB ChB, FCP (SA), Medical Director at Epicentre Walk-In Labs. Reviewed 9 June 2026. This article is general health information, not a medical diagnosis. Epicentre Aids Risk Management (Pty) Ltd provides diagnostic laboratory testing and does not provide diagnoses, treatment or prescriptions to the public; results are intended to inform discussions with a registered healthcare practitioner.
Find out if Gardnerella is behind your symptoms
The BV Microbiome Test measures Gardnerella and your full vaginal flora from one self-collected swab. Walk in at Observatory, Hillcrest or Parktown North, or order a discreet home kit.
