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Development of a Larval Zebrafish Infection Model for Clostridioides difficile
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The σB signalling activation pathway in the enteropathogen Clostridioides difficile
Nicolas Kint1,2, Carolina Alves Feliciano1,2, Audrey Hamiot1,2
1Laboratoire Pathogenèse des Bactéries Anaérobies, Institut Pasteur, Paris, France.
Environmental Microbiology
|April 30, 2019
Summary
Clostridium difficile stress response involves the sigma B (σB) pathway. A phosphatase, RsbZ, is crucial for activating σB by dephosphorylating RsbV, enabling cell survival.
Area of Science:
- Microbiology
- Molecular Biology
- Bacterial Pathogenesis
Background:
- Clostridium difficile causes antibiotic-associated diarrhea.
- Bacterial stress responses, including the sigma B (σB) pathway, are vital for survival.
- σB activation typically involves a partner-switching mechanism.
Purpose of the Study:
- Investigate the σB activation signaling pathway in Clostridium difficile.
- Identify key proteins and mechanisms regulating σB activity in this pathogen.
Main Methods:
- Gene expression analysis of sigB.
- Confirmation of the RsbV-RsbW-σB partner-switching mechanism.
- Functional characterization of RsbZ (CD2685) and CD2684 in σB activation.
Main Results:
- Clostridium difficile sigB expression is constitutive, unlike other firmicutes.
- RsbZ, a PP2C phosphatase, is essential for RsbV dephosphorylation and σB activation.
- CD2684 depletion inhibits σB activation; CD0007 and CD0008 are not involved.
- σB exhibits heterogeneous activity in exponential phase cells, suggesting a bet-hedging survival strategy.
Conclusions:
- The study elucidates a unique σB activation pathway in Clostridium difficile.
- RsbZ and its phosphatase activity are critical for triggering σB.
- Heterogeneous σB activity may enhance Clostridium difficile survival under stress.
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