The Sneaky Bacteria Behind Bacterial Vaginosis (BV)

Understanding what’s really going on down there

Bacterial vaginosis — often referred to as BV — is one of the most common vaginal conditions affecting people of reproductive age. If you’ve ever noticed an unusual discharge, a fishy odour, or vaginal irritation, BV could be the cause. But unlike infections caused by a single germ, BV is more like a microbial mutiny — caused by a disruption of the natural bacterial balance in the vagina.

A Delicate Balance

Under healthy conditions, the vagina is dominated by protective bacteria called Lactobacillus. These bacteria keep the vaginal pH slightly acidic, creating an environment that helps prevent infections. When this balance is thrown off — by antibiotics, sexual activity, hormonal changes, or douching — the Lactobacillus population can drop. This allows less friendly, opportunistic bacteria to overgrow (Chen et al., 2021).

Who Are the Culprits?

BV isn’t caused by just one bad germ. It happens when the healthy bacteria in your vagina — mostly Lactobacillus — get outnumbered by other bacteria that thrive in a less acidic, low-oxygen environment (Chen et al., 2021). This imbalance can cause symptoms like unusual discharge, a fishy smell, itching, or irritation — but sometimes, there are no symptoms at all, which is why testing is so important.

Epicentre’s Women’s Large and Extra-Large Sexual Health Packages are designed to look for the specific bacteria linked to BV:

> Gardnerella vaginalis – This is the main bacteria behind BV. It forms sticky layers (called biofilms) that help other harmful bacteria stick around and make treatment harder (Machado & Cerca, 2015).

> Atopobium vaginae – Often found in women with recurring BV, it teams up with Gardnerella to build biofilms and can make BV harder to get rid of (Chen et al., 2021).

> Prevotella bivia – Produces chemicals that cause the strong “fishy” smell and adds to the irritation (Spiegel, 1991).

> Mobiluncus species – These bacteria are common in more severe cases of BV and are linked to inflammation (Bradshaw & Brotman, 2015).

> BVAB2 – A specific marker that strongly points to BV, even when there aren’t any obvious symptoms. Many labs don’t test for it, but Epicentre does (Chen et al., 2021).

> Megasphaera types 1 and 2 – These are harder to detect in normal lab tests but are often found in more severe or complicated BV cases.

The test also checks for E. coli O18 and Enterococcus faecalis — these aren’t the main causes of BV but are often present when the vaginal environment is off balance.

To see how healthy your vaginal flora is, the package also looks for good bacteria like Lactobacillus crispatus, gasseri, jensenii, and iners. Low levels of these are a sign that your natural protection is weakened (Chen et al., 2021).

It also includes Candida (yeast) species like C. albicans and C. glabrata, because yeast infections can show up alongside BV, especially after taking antibiotics.

🔍 Important: The UTI Package is better suited for bladder infections (like when it burns to pee) and tests for E. coli, Staph aureus, and some Candida species. But it doesn’t include the key BV bacteria like Gardnerella or Atopobium, so it’s not recommended if you think you have BV.

Package Best For BV-Related Coverage Notes
UTI Package UTI symptoms ❌ Very limited  Skip this for BV
Women’s Large Most people with suspected BV ✅ Strong coverage Best value
Women’s Extra-Large Recurrent or complex vaginal issues ✅✅ Full panel Most comprehensive

Our BV Packages

  • Cervical / Vulvo-Vaginal Large Sexual Health Package

    Includes: Atopobium vaginae, Bacterial vaginosis-associated bacteria 2 (BVAB2), Candida spp, Chlamydia trachomatis, Escherichia coli O18, Gardnerella vaginalis, Herpes simplex virus, Human Papilloma virus (HPV), Lactobacillus spp, Mobiluncus spp, Mycoplasma genitalium, Mycoplasma hominis, Neisseria gonorrhoeae, Prevotella bivia, Trichomonas vaginalis, Uncultured Megasphaera spp, Ureaplasma urealyticum

    Lab results in 5 to 7 working days - No referral required

  • Cervical / Vulvo-vaginal Extra Large Sexual Health Package

    Includes: Atopobium vaginae, BVAB2, Bacteroides fragilis, Enterococcus faecalis, Escherichia coli O18. Gardnerella vaginalis, Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, Lactobacillus jensenii, Mobiluncus curtisii, Mobiluncus mulieris, Prevotella bivia, Staphylococcus aureus, Streptococcus agalactiae, Uncultured Megasphaera 1, Unclutured Megasphaera 2, Candida albicans, Candida dubliniensis, Candida glabrata, Candida krusei, Candida lusitaniae, Candida parapsilosis, Candida tropicalis, Chlamydia trachomatis, Haemophilus ducreyi, Mycoplasma genitalium, Mycoplasm hominis, Neisseria gonorrhoeae, Treponema pallidum, Ureaplasma urealyticum, Trichomonas vaginalis, Herpes Simplex Virus type 1, Herpes simplex virus type 2, HPV

    Lab results in 5 to 7 working days - No referral required

What Makes These Bacteria So Troublesome?

BV-causing bacteria are problematic not just because they replace healthy microbes, but because they:

1. Form biofilms, which protect them from treatment and immune responses

2. Raise the vaginal pH, which encourages even more harmful bacteria to grow

3. Are linked to serious health concerns like preterm birth, pelvic inflammatory disease, and increased risk of HIV/STI transmission.

Is BV an STI?

BV is not classified as a sexually transmitted infection (STI), but sexual activity — especially with new or multiple partners — can increase the risk of developing it. This is because sex can introduce or encourage the overgrowth of BV-associated bacteria.

Know Your Flora

Understanding the bacterial causes of BV helps us appreciate how important it is to maintain the vaginal microbiome. Avoiding unnecessary antibiotics, skipping harsh soaps or douches, and using protection with new partners are all steps that can help keep the peace in your vaginal ecosystem.

And if something feels off — don’t be embarrassed. BV is common, treatable, and nothing to be ashamed of. Knowing the bacteria involved gives you the power to take charge of your health.

📚 References (APA 7th)

Bradshaw, C. S., & Brotman, R. M. (2015). Making inroads into improving treatment of bacterial vaginosis — striving for long-term cure. BMC Infectious Diseases, 15, 292. https://doi.org/10.1186/s12879-015-1044-3

Chen, C., Song, X., Wei, W., Zhong, H., Dai, J., Lan, Z., … & Xu, C. (2021). The microbiota continuum along the female reproductive tract and its relation to uterine-related diseases. Frontiers in Cellular and Infection Microbiology, 11, 672429. https://doi.org/10.3389/fcimb.2021.672429

Kenyon, C., Colebunders, R., & Crucitti, T. (2013). The global epidemiology of bacterial vaginosis: a systematic review. American Journal of Obstetrics and Gynecology, 209(6), 505–523. https://doi.org/10.1016/j.ajog.2013.05.006

Machado, D., & Cerca, N. (2015). Influence of biofilm formation by Gardnerella vaginalis and other anaerobes on bacterial vaginosis. Journal of Infectious Diseases, 212(12), 1856–1861. https://doi.org/10.1093/infdis/jiv338

Spiegel, C. A. (1991). Bacterial vaginosis. Clinical Microbiology Reviews, 4(4), 485–502. https://doi.org/10.1128/cmr.4.4.485

All Our Sexual Health Packages

  • Urinary Tract Infection (UTI) Package

    Includes: E. coli, E. faecalis, C. albicans, C. albicans, C. dubliniensis, C. glabrata, C. krusei, C. lusitaniae, Candida parapsilosis, C. tropicalis, S. aureus S. agalactiae

    Lab results in 5 to 7 working days - No referral required

  • Cervical / Vulvo-Vaginal Large Sexual Health Package

    Includes: Atopobium vaginae, Bacterial vaginosis-associated bacteria 2 (BVAB2), Candida spp, Chlamydia trachomatis, Escherichia coli O18, Gardnerella vaginalis, Herpes simplex virus, Human Papilloma virus (HPV), Lactobacillus spp, Mobiluncus spp, Mycoplasma genitalium, Mycoplasma hominis, Neisseria gonorrhoeae, Prevotella bivia, Trichomonas vaginalis, Uncultured Megasphaera spp, Ureaplasma urealyticum

    Lab results in 5 to 7 working days - No referral required

  • Comprehensive HPV Package

    Includes: HPV-6, HPV-11, HPV-40, HPV-42, HPV-43, HPV-44, HPV-54, HPV-61, HPV-16, HPV-18, HPV-26, HPV-31, HPV-33, HPV-35, HPV-39, HPV-45, HPV-51, HPV-52, HPV-53, HPV-56, HPV-58, HPV-59, HPV-66, HPV-68, HPV-69, HPV-70, HPV-73

    Lab results in 5-7 working days. No referral required

  • Cervical / Vulvo-vaginal Extra Large Sexual Health Package

    Includes: Atopobium vaginae, BVAB2, Bacteroides fragilis, Enterococcus faecalis, Escherichia coli O18. Gardnerella vaginalis, Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, Lactobacillus jensenii, Mobiluncus curtisii, Mobiluncus mulieris, Prevotella bivia, Staphylococcus aureus, Streptococcus agalactiae, Uncultured Megasphaera 1, Unclutured Megasphaera 2, Candida albicans, Candida dubliniensis, Candida glabrata, Candida krusei, Candida lusitaniae, Candida parapsilosis, Candida tropicalis, Chlamydia trachomatis, Haemophilus ducreyi, Mycoplasma genitalium, Mycoplasm hominis, Neisseria gonorrhoeae, Treponema pallidum, Ureaplasma urealyticum, Trichomonas vaginalis, Herpes Simplex Virus type 1, Herpes simplex virus type 2, HPV

    Lab results in 5 to 7 working days - No referral required