# Role of circadian rhythms in the susceptibility to Clostridium difficile infection

> **NIH NIH R21** · TEXAS A&M UNIVERSITY · 2020 · $215,884

## Abstract

Project Summary
Clostridium difficile is now the most common cause of hospital-acquired infections in the United
States. This Gram-positive, spore-forming, strict anaerobe most commonly infects antibiotic-
treated hosts, though community-acquired infections are on the rise for unknown reasons. To
survive outside a host, C. difficile produces dormant spores. Spores are metabolically dormant
forms of bacteria that are resistant to many harsh conditions (e.g., many cleaning agents, heat,
radiation and antibiotics). In a host, C. difficile spores germinate in response to bile acids.
Following C. difficile spore germination, the vegetative cells produce the toxins that trigger the
host’s inflammatory response and that cause the primary symptoms of disease. Remarkably,
the effectors of C. difficile infection (e.g., toxin receptor abundance and inflammation) exhibit
strong circadian rhythms. These rhythms are generated by molecular circadian clocks found in
virtually every mammalian cell, and which rely on transcriptional feedback loops to coordinate
the rhythmic expression of about 10-15% of the genome. The circadian nature of the host
physiology suggests that the normal host circadian rhythms may impact the efficiency with
which C. difficile infects, colonizes and causes disease. In this exploratory application, the
effects of host circadian biology on the ability of C. difficile to colonize and on the host’s
inflammatory response to C. difficile infection will be explored.

## Key facts

- **NIH application ID:** 9895923
- **Project number:** 1R21AI144454-01A1
- **Recipient organization:** TEXAS A&M UNIVERSITY
- **Principal Investigator:** Jerome Menet
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $215,884
- **Award type:** 1
- **Project period:** 2020-01-31 → 2021-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9895923

## Citation

> US National Institutes of Health, RePORTER application 9895923, Role of circadian rhythms in the susceptibility to Clostridium difficile infection (1R21AI144454-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9895923. Licensed CC0.

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