Binary Toxin Expression by Clostridioides difficile Is Associated With Worse Disease

Area of Science:

• Infectious Diseases
• Microbiology
• Clinical Medicine

Background:

• Clostridioides difficile infection (CDI) incidence has risen, posing an urgent public health threat.
• Hypervirulent CDI strains, like ribotype 027, produce C. difficile binary toxin (CDT), increasing morbidity and mortality.

Purpose of the Study:

• To investigate the correlation between CDT positivity in patients with CDI and disease severity.
• To assess the impact of CDT on clinical outcomes, including mortality.
• To examine the relationship between CDT and fecal microbiota composition in CDI patients.

Main Methods:

• Retrospective analysis of stool samples from 215 CDI patients.
• Enzyme-linked immunosorbent assay (ELISA) to detect CDT and quantitative PCR (qPCR) for the cdtB gene.
• 16S rRNA gene sequencing to analyze fecal microbiota composition.

Main Results:

• CDT-positive patients exhibited more severe CDI, higher 90-day mortality, increased C. difficile bacterial load, and elevated white blood cell counts.
• No significant difference in gut microbiome diversity was observed between CDT-positive and CDT-negative patients.
• ELISA detection of C. difficile binary toxin (CdtB) correlated with adverse clinical outcomes.

Conclusions:

• Fecal CDT positivity in CDI patients is associated with increased disease severity and poorer clinical outcomes.
• Standard diagnostic methods (PCR, toxins A/B testing) may not fully capture CDI severity.
• Detecting CDT-expressing strains is crucial for identifying patients at higher risk for severe CDI.