# Advancing studies of polymicrobial diseases via streptococcal genetics

> **NIH NIH R35** · OREGON HEALTH & SCIENCE UNIVERSITY · 2021 · $992,002

## Abstract

PROJECT SUMMARY/ABSTRACT
A myriad of human mucosal diseases are intimately connected with the ecology of the flora residing at
disease sites. The etiology of these complex polymicrobial diseases is poorly described by Koch's
Postulates and the key mechanisms of polymicrobial pathogenesis are still emerging in the field. The
limited utility of traditional antibiotic therapies as well as our inadequate understanding of polymicrobial
disease etiology are both currently significant hurdles for the effective treatment of these diseases. The
thematic basis for the current proposal is to utilize genetically tractable members of the oral flora as a
model system to investigate the mechanistic and regulatory foundations of polymicrobial synergy as
well as potential mechanisms to counteract synergistic pathogenesis in these types of diseases. The
proposed research program will consist of 3 conceptually complementary research foci: 1) the genetic
control of virulence, 2) mechanisms of polymicrobial synergy, and 3) novel strategies for targeted
inhibition of bacteria. Success in each of these focus areas will be leveraged by our established
strengths in oral bacterial genetics and the application of a state-of-the-art genetic system. We are
proposing to further develop Streptococcus mutans as a preeminent model organism for genetic
studies of flora pathobiology, while also developing a new model system of polymicrobial synergy using
abscess clinical isolates of Anginosus group streptococci in combination with abscess clinical isolates
of Fusobacterium spp. and Prevotella spp. The Anginosus streptococci are vastly understudied
members of the oral flora strongly associated with the formation of severe polymicrobial abscesses in
the oral cavity and throughout the body. Such abscesses are surprisingly common, yet little is known
about the pathogenic mechanisms involved, other than the essential role of polymicrobial synergy,
especially with Fusobacterium and Prevotella species. Thus, we envision utilizing the long-term support
provided by the R35 mechanism to both augment our existing programmatic strengths and also to grow
our research program in an understudied area of major clinical significance.

## Key facts

- **NIH application ID:** 10212366
- **Project number:** 5R35DE028252-04
- **Recipient organization:** OREGON HEALTH & SCIENCE UNIVERSITY
- **Principal Investigator:** Justin Merritt
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $992,002
- **Award type:** 5
- **Project period:** 2018-09-01 → 2026-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10212366

## Citation

> US National Institutes of Health, RePORTER application 10212366, Advancing studies of polymicrobial diseases via streptococcal genetics (5R35DE028252-04). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10212366. Licensed CC0.

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