Decoding BVAB1, BVAB2, BVAB3 in Bacterial Vaginosis Tests

You may have had a vaginal test result come back that tested positive or negative for the opaquely named ‘BVAB’ species, BVAB1, BVAB2 or BVAB3.¹ These bacteria are like babies whose parents haven’t named them yet!

BVAB stands for Bacterial Vaginosis Associated Bacterium

BVAB are recently discovered bacteria related to or in the Clostridiales order that are highly specific for diagnosing bacterial vaginosis (BV). BVAB1, BVAB2 and BVAB3 are each a single bacteria.

They are slowly being named, and the BVAB name will disappear as this occurs.

BVAB1 – Candidatus Lachnocurva vaginae² (candidatis means it’s still a candidate for a real name!)
BVAB2 – ?
BVAB3 – Mageeibacillus indolicus³

Because these bacteria are still being classified and their genetics are being traced to determine where they fit in, their names may change or emerge. This happens all the time in microbiology.

The bacteria have been provisionally named using DNA sequencing and matching in DNA libraries.

The research into BVABs

In one research project of 73 vaginal fluid samples with and without BV, BVAB1 was found in 41 per cent of the samples, and BVAB2 was found in 89 per cent of BV-diagnosed vaginal fluid samples.

Information from the DNA libraries revealed that these three species were highly correlated with bacterial vaginosis.

In two samples where BV tests were negative, but tests for BVAB came back positive for two types, BV developed within a few months of the tests. BVAB2 was found in 89 per cent of the fluid samples with BV. Meaning these bacteria are typically not present in vaginas that are not about to, or have, bacterial vaginosis.

BVAB bacteria is more specific as a predictor for BV than Atopobium vaginae, which is highly specific for treatment-resistant recurrent BV, though A. vaginae can exist in vaginas without symptoms.

How do I get more information?

The BVAB bacteria may have been found on a vaginal microbiome test, but it has left you guessing what it means. If you want more information on BVAB – and whatever else was found in your vagina – get a comprehensive vaginal microbiome test.

If you need support for interpreting your vaginal microbiome reports or a treatment plan, even for the most complex cases, book with a My Vagina expert practitioner.

References

1.
Fredricks DN, Fiedler TL, Marrazzo JM. Molecular Identification of Bacteria Associated with Bacterial Vaginosis. N Engl J Med. Published online November 3, 2005:1899-1911. doi:10.1056/nejmoa043802
2.
Holm JB, France MT, Ma B, et al. Comparative Metagenome-Assembled Genome Analysis of “Candidatus Lachnocurva vaginae”, Formerly Known as Bacterial Vaginosis-Associated Bacterium−1 (BVAB1). Front Cell Infect Microbiol. Published online March 31, 2020. doi:10.3389/fcimb.2020.00117
3.
Austin MN, Rabe LK, Srinivasan S, Fredricks DN, Wiesenfeld HC, Hillier SL. Mageeibacillus indolicus gen. nov., sp. nov.: A novel bacterium isolated from the female genital tract. Anaerobe. Published online April 2015:37-42. doi:10.1016/j.anaerobe.2014.12.003