C. difficile Infection

Microbiology, diagnostic stewardship, testing nuances & clinical decision-making

Content

The Organism

Biology & Transmission

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Clostridioides difficile is an anaerobic, Gram-positive, spore-forming bacillus transmitted via the fecal-oral route.

Spore Form

Hardy and environmentally stable — survives on surfaces for months
Resistant to alcohol-based hand sanitizers
Soap and water required to physically remove spores from hands
Primary vector for transmission in healthcare settings

Vegetative Form

Actively replicates in the colon when colonic flora is disrupted
Produces Toxin A (enterotoxin) and Toxin B (cytotoxin)
Toxins cause epithelial cell death and intestinal inflammation
Responsible for all clinical manifestations of disease

Clinical Pearl

Only the vegetative form causes disease, but only the spore form survives in the environment and causes transmission. This distinction is critical for infection control.