Thursday, April 25, 2024 4/25/2024

Global regulation in Clostridium difficile via phase variation of cyclic diguanylate signaling

Award Number: R01AI143638
ORGANIZATION: NATIONAL INSTITUTE OF ALLERGY & INFECTIOUS DISEASES
OPDIV: NIH
AWARD CLASS: DISCRETIONARY
AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)

Group Awards By Issue Date FY or Funding FY:

View Award Abstract

PROJECT SUMMARY Clostridium difficile is a major public health threat, causing disease ranging from mild diarrhea to potentially fatal pseudomembranous colitis. C. difficile disease symptoms are largely mediated by the secreted cytotoxins, TcdA and TcdB. Many aspects of the pathogenicity of this bacterium remains poorly understood, including how C. difficile adapts to the host intestinal environment. The components of the bacterial cell surface play critical roles in physiology and virulence and are commonly immunogenic antigens and potential antibiotic targets. In C. difficile the signaling molecule cyclic diguanylate (c-di-GMP) controls the production of flagella, type IV pili, and multiple additional cell surface proteins, indicating a key role for c-di-GMP in reorganizing the C. difficile cell surface in response to the host intestinal environment. Phase variation is a means by which many bacterial species introduce phenotypic heterogeneity into the population as a strategy to ensure survival of the population in the face of changing selective pressures. We recently showed that flagella and toxins phase vary in C. difficile, and sequencing analyses identified several other putative phase variable loci including two that encode c-di-GMP hydrolases. Our central hypothesis is that C. difficile combines c-di-GMP signaling and phase variation to coordinate global changes to the cell surface, enabling adaptation to extracellular pressures encountered during colonization of the intestinal tract. The objective of this proposal is to define the mechanisms of phase variation that control c-di-GMP signaling, the phenotypic responses to changes in c-di- GMP, and the impact of these regulatory mechanisms on C. difficile physiology and virulence. To accomplish this goal, we employ molecular genetics, biochemical techniques, and animal models of C. difficile disease to examine phase variation and c-di-GMP signaling at the population and single cell levels. Our discovery that C. difficile links phase variation with c-di-GMP signaling reveals a previously unknown mechanism for coordinated modification of the bacterial cell surface. Completion of these aims may expose new targets for attenuating C. difficile fitness in the host, facilitating efforts to combat this increasingly problematic pathogen.


Issue Date FY	Funding FY	Legal Entity Name	Legal Entity Address	Legal Entity City	Legal Entity State	Legal Entity Zip Code	Legal Entity COUNTY	Legal Entity COUNTRY	Assistance Listing	Award Code	Budget Year	Action Date	Action Type	Action Amount

Issue Date FY: 2023 ( Subtotal = $498,391 )
2023	2023	UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL	104 AIRPORT DR STE 2200	CHAPEL HILL	NC	27599	ORANGE	USA	Allergy and Infectious Diseases Research	000	5	8/16/2023	NON-COMPETING CONTINUATION	$498,391
														Subtotal = $498,391

Issue Date FY: 2022 ( Subtotal = $498,391 )
2022	2022	UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL	104 AIRPORT DR STE 2200	CHAPEL HILL	NC	27599	ORANGE	USA	Allergy and Infectious Diseases Research	000	4	8/19/2022	NON-COMPETING CONTINUATION	$498,391
														Subtotal = $498,391

Issue Date FY: 2021 ( Subtotal = $498,391 )
2021	2021	UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL	104 AIRPORT DR STE 2200	CHAPEL HILL	NC	27599	ORANGE	USA	Allergy and Infectious Diseases Research	000	3	8/12/2021	NON-COMPETING CONTINUATION	$498,391
														Subtotal = $498,391

Issue Date FY: 2020 ( Subtotal = $508,480 )
2020	2020	UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL	104 AIRPORT DR STE 2200	CHAPEL HILL	NC	27599	ORANGE	USA	Allergy and Infectious Diseases Research	001	2	8/5/2020	NON-COMPETING CONTINUATION	$508,480
2020	2019	UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL	104 AIRPORT DR STE 2200	CHAPEL HILL	NC	27599	ORANGE	USA	Allergy and Infectious Diseases Research	000	1	11/4/2019	NEW	$0
														Subtotal = $508,480

Issue Date FY: 2019 ( Subtotal = $508,480 )
2019	2019	UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL	104 AIRPORT DR STE 2200	CHAPEL HILL	NC	27599	ORANGE	USA	Allergy and Infectious Diseases Research	000	1	9/18/2019	NEW	$508,480
														Subtotal = $508,480

Grand Total All Awards = $2,512,133

Top

All Categories

About

Search

Reports

Data Submission

Award Information

Global regulation in Clostridium difficile via phase variation of cyclic diguanylate signaling

Award Number: R01AI143638

ORGANIZATION: NATIONAL INSTITUTE OF ALLERGY & INFECTIOUS DISEASES

OPDIV: NIH

AWARD CLASS: DISCRETIONARY

AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)

Federal Websites

Department of Health & Human Services

HHS Operating Divisions

HHS Staff Divisions

Download A Document Viewer