# Quorum sensing evolution and function in mixed bacterial communities

> **NIH NIH R35** · UNIVERSITY OF KANSAS LAWRENCE · 2021 · $368,145

## Abstract

PROJECT SUMMARY
Most bacteria are found in complex microbial communities, where social interactions between community
members shape community function and behavior. One of the mechanisms by which bacteria regulate these
interactions is through quorum sensing, a type of cell-cell signaling that regulates behaviors in a population
density-dependent manner. Quorum sensing contributes to pathogenesis of many plant and animal pathogens
and for this reason has been the target of efforts to develop novel antivirulence therapeutics. Previously, studies
of quorum sensing, including infection models, have been primarily carried out using clonal populations. Results
of those studies have been useful to elucidate the molecular biology of quorum sensing but provide a limited
understanding the role of quorum sensing in more complex communities such as those from the environment
and infections. Direct studies of naturally occurring mixed microbial communities present many challenges. A
combination of new technologies in genomics and genetics and the development of laboratory models or
`synthetic ecology' approaches have advanced progress on studies of non-clonal bacterial populations. The PI
has developed laboratory models to study quorum sensing in mixed-strain and mixed-species populations to
define how quorum sensing promotes survival in these communities. A major result of these studies is that
quorum sensing increases resistance to antibiotics and that this regulation alters the dynamics of competition
among and between strains of soil bacteria. Quorum sensing also regulates antibiotic resistance in the
opportunistic pathogen P. aeruginosa, and this regulation could be important in the face of antibiotic therapy
during infections. The studies in this proposal will build on these preliminary results and use laboratory models
and clinical infection isolates to study quorum-sensing control of antibiotic resistance. The studies will provide a
mechanistic understanding of quorum-regulated antibiotic resistance, define how quorum-sensing systems
adapt under selection by antibiotics, and determine how quorum sensing alters resistance phenotypes among
individual members of a population. The results will provide a more complete picture of how quorum sensing
alters population dynamics in complex communities and in patient infections. This information is needed to
develop novel disease treatment strategies that rely on manipulating the quorum-sensing systems of pathogens.
The results will have implications in the field of quorum sensing, for understanding social behavior in a broader
sense, and finally, for understanding how social behaviors can be targeted for effective treatment of polymicrobial
infections.

## Key facts

- **NIH application ID:** 10169474
- **Project number:** 5R35GM133572-03
- **Recipient organization:** UNIVERSITY OF KANSAS LAWRENCE
- **Principal Investigator:** Josephine R Chandler
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $368,145
- **Award type:** 5
- **Project period:** 2019-07-30 → 2024-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10169474

## Citation

> US National Institutes of Health, RePORTER application 10169474, Quorum sensing evolution and function in mixed bacterial communities (5R35GM133572-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10169474. Licensed CC0.

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