# Gardnerella vaginalis small colony variants

> **NIH NIH R21** · UNIVERSITY OF WISCONSIN-MADISON · 2021 · $232,938

## Abstract

PROJECT SUMMARY
Bacterial vaginosis (BV) is the most common gynecological disorder in women of childbearing age and is
associated with adverse pregnancy outcomes and enhanced transmission of sexually-transmitted diseases.
Gardnerella vaginalis is the signature bacterial species associated with BV, but its mechanisms of infection
and persistence are not well understood. Furthermore, the mechanisms by which G. vaginalis infection recurs
after antibiotic treatment are not known. We have discovered that G. vaginalis grows in two different forms, as
a slow-growing small colony variant (SCV) and as a faster-growing large colony variant (LCV). The SCV form
produces more of the toxin vaginolysin, is more antibiotic resistant, and is more inhibitory to the growth of
Lactobacillus spp. The LCV produces more biofilms and is more inhibitory to the growth of Neisseria
gonorrhoeae. Preliminary proteomic analyses indicate that SCVs downregulate DNA replication and protein
synthesis and upregulate vaginolysin and other putative virulence factors. We hypothesize that the SCV is a
form of the bacteria primed for initiating infection or for persisting under adverse conditions, while the LCV
gives faster multiplication and builds the biofilm that supports multiple BV-associated pathogens. For these
studies, we will characterize differences in infection abilities of the SCVs and make mutants to characterize
the key factors involved in the increased virulence and altered metabolism of the variant form. Pathogenesis
studies will include infection of human cervical tissue in organ culture. We will identify mechanisms involved in
persistence and survival in adverse conditions using proteomics and measurements of antibiotic resistance,
and we will identify factors stimulating phase variation.

## Key facts

- **NIH application ID:** 10218441
- **Project number:** 1R21AI153534-01A1
- **Recipient organization:** UNIVERSITY OF WISCONSIN-MADISON
- **Principal Investigator:** Joseph P Dillard
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $232,938
- **Award type:** 1
- **Project period:** 2021-02-15 → 2023-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10218441

## Citation

> US National Institutes of Health, RePORTER application 10218441, Gardnerella vaginalis small colony variants (1R21AI153534-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10218441. Licensed CC0.

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