General information:

Bacterial Vaginosis test combination (Gardnerella, Prevotella, Bacteroides, Mobiluncus): Causes, Diagnosis and Modern Laboratory Testing

Bacterial vaginosis (BV) is the most common cause of abnormal vaginal discharge in women of reproductive age. It occurs when the normal vaginal microbiota — dominated by protective Lactobacillus species — becomes disrupted. This imbalance allows anaerobic bacteria such as Gardnerella vaginalis, Prevotella spp., Bacteroides spp., and Mobiluncus spp. to overgrow.

Modern laboratory diagnostics now allow highly accurate identification of the microorganisms involved, helping clinicians choose the most appropriate treatment and reduce the risk of recurrence.

What Causes Bacterial Vaginosis?

BV is not caused by a single pathogen. Instead, it results from a shift in the vaginal ecosystem. The most commonly involved bacteria include:

• Gardnerella vaginalis – the primary marker organism

• Prevotella species – anaerobes associated with inflammation

• Bacteroides species – contribute to odor and discharge

• Mobiluncus species – strongly linked to BV in microscopy

• Atopobium vaginae – often found in persistent or recurrent cases

These microorganisms replace the normal lactobacilli, leading to elevated vaginal pH and characteristic symptoms.

Common Symptoms of Bacterial Vaginosis

Although some women remain asymptomatic, BV often presents with:

• thin grey‑white vaginal discharge

• unpleasant “fishy” odor, especially after intercourse

• mild burning or discomfort

• minimal redness or itching (unlike yeast infections)

Untreated BV can increase the risk of sexually transmitted infections, pregnancy complications, and recurrent vaginal imbalance.

How BV Is Diagnosed: Modern Laboratory Methods

Our laboratory uses a combination of microscopy, antigen testing, MALDI‑TOF identification, automated antibiotic susceptibility testing, and PCR diagnostics to ensure the highest accuracy.

1. Microscopic Examination (Nugent / Amsel Criteria)

Microscopy remains a cornerstone in BV diagnosis. It allows:

• detection of clue cells

• assessment of lactobacilli reduction

• visualization of anaerobic overgrowth

• identification of Mobiluncus morphology

• evaluation of vaginal cleanliness

This rapid method provides immediate insight into the vaginal microbiome.

2. Bacterial vaginosis (Gardnerella, Prevotella, Bacteroides,Mobiluncus) Antigen Test

As part of the diagnostic panel, we include a rapid antigen test. It detects specific bacterial proteins and is especially useful for:

• suspected BV

• mixed vaginal infections

• recurrent symptoms

• cases requiring fast results

The test is highly sensitive, specific, and does not require bacterial culture.

When Should You Test for Bacterial Vaginosis?

Testing is recommended when experiencing:

• abnormal vaginal discharge

• unpleasant odor

• recurrent vaginal infections

• discomfort after intercourse

• symptoms during pregnancy

• unclear or persistent symptoms despite treatment

Additional Molecular Testing (PCR)

Depending on the microscopic and culture findings, the microbiologist may recommend:

• PCR vaginal microbiome panel

• PCR for sexually transmitted pathogens (Chlamydia, Mycoplasma, Ureaplasma, Trichomonas)

• HPV testing for high‑risk types

These tests provide deeper insight into chronic or recurrent conditions.

Sample Collection Instructions

To ensure accurate results:

• avoid vaginal douching and gels for 48 hours

• avoid intercourse for 24–48 hours

• avoid vaginal medications for 72 hours (unless advised otherwise)

• do not test during menstruation

• external washing with water only on the day of testing