# Enterococcal Sex pheromones: impact on antibiotic resistance transfer and ecology of the gastrointestinal tract

> **NIH NIH R35** · UNIVERSITY OF MINNESOTA · 2020 · $8,778

## Abstract

PROJECT SUMMARY
This project will examine the role of determinants encoded by highly transmissible plasmid pCF10 of
Enterococcus faecalis, and how these genes mediate plasmid transfer and persistence of enterococci in the
mammalian gastrointestinal tract. E. faecalis is a leading cause of hospital-acquired infections whose
treatment is impeded by the inherent and acquired antibiotic resistance of the organism, and by its ability to
transition between commensal and pathogenic lifestyles. It is well understood that antibiotic treatment or
impairment of normal host defenses can result in overgrowth of enterococci in the intestine. However, we
know very little about the inherent traits that allow the organism to establish in a healthy intestine, or how
antibiotic-resistance plasmids like pCF10 might impact competitive fitness of their bacterial host in the GI
tract independent of antibiotic resistance. We will study the interactions between pCF10-carrying donor
strains and plasmid-free recipients in germ-free mice, and in “humanized” animals carrying a human-derived
gut microbial community. We will use powerful new screens to identify genetic determinants of competitive
fitness and plasmid transfer in the GI tract, and begin to study their functions and mechanisms of action. We
will use high-resolution microscopic techniques to examine the behavior of the organisms in vivo, and the
expression of genes of interest. The results of this research will include the following:
 1) We will determine the inherent frequencies of pCF10 transfer in various regions of the GI tract in
 the absence of antibiotic selection.
 2) We will identify genes on both the plasmid and chromosome that impact transfer and competitive
fitness.
 3) We will use mathematical modeling and laboratory studies of regulatory mechanisms to correlate
 the functions of genetic control circuits to the enterococcal behavior in the natural environment.
 4) In the longer term, we may identify new ecologically based strategies, which could reduce
 enterococcal infections or the spread of antibiotic resistance.

## Key facts

- **NIH application ID:** 10145461
- **Project number:** 3R35GM118079-05S1
- **Recipient organization:** UNIVERSITY OF MINNESOTA
- **Principal Investigator:** GARY M DUNNY
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $8,778
- **Award type:** 3
- **Project period:** 2016-06-07 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10145461

## Citation

> US National Institutes of Health, RePORTER application 10145461, Enterococcal Sex pheromones: impact on antibiotic resistance transfer and ecology of the gastrointestinal tract (3R35GM118079-05S1). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10145461. Licensed CC0.

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