Time-resolved transcriptome analysis of Clostridium difficile R20291 response to cysteine

Area of Science:

• Microbiology
• Molecular Biology
• Genomics

Background:

• Clostridium difficile infection (CDI) incidence is rising, linked to hypervirulent NAP1/BI/027 strains.
• Mechanisms regulating virulence in CDI outbreaks remain unclear.
• Cysteine may repress major C. difficile toxins TcdA and TcdB.

Purpose of the Study:

• Investigate cysteine's functional and virulence-associated regulation of C. difficile R20291.
• Utilize time-resolved, genome-wide transcriptome analysis to understand gene expression changes.

Main Methods:

• Time-resolved genome-wide transcriptome analysis of C. difficile R20291.
• Gene expression profiling in the presence of cysteine across different growth phases.
• Analysis of cdsB inactivation effects on toxin and butyrate production.

Main Results:

• Cysteine significantly altered gene expression, affecting transport, metabolism, and regulatory pathways.
• Flagellar and ribosomal genes were downregulated long-term in response to cysteine.
• Cysteine modulated NAP1/BI/027-specific genes; cdsB inactivation relieved toxin repression but not butyrate repression.

Conclusions:

• Cysteine influences C. difficile gene expression, impacting virulence-related functions.
• Toxin synthesis and butyrate production appear to have distinct regulatory controls responding to cysteine.
• Findings offer insights into C. difficile regulatory mechanisms and cysteine's role.