Clostridioides difficile (formerly Clostridium difficile), commonly abbreviated as C. difficile or C. diff, is a Gram-positive, spore-forming, anaerobic bacterium that represents a significant concern in both clinical and research settings.

Pathogen Profile

Clinical Significance

C. difficile causes symptoms ranging from mild diarrhea to life-threatening pseudomembranous colitis and toxic megacolon. The bacterium produces two primary toxins—toxin A (enterotoxin) and toxin B (cytotoxin)—that damage the intestinal lining and trigger inflammatory responses.

Laboratory Animal Concerns

In research environments, C. difficile poses distinct challenges:

Unintended Contamination Risks:

• Spores can survive for months on surfaces and equipment
• Environmental contamination can affect cages, racks, and procedural areas
• Cross-contamination between animal cohorts can occur through shared equipment or handler contact
• Animals may be asymptomatic carriers, complicating detection

Research Impact:

• Gastrointestinal colonization can introduce unwanted variables in studies involving:
  • Microbiome research
  • Immune system function
  • Metabolic studies
  • Nutritional research
  • Pharmaceutical testing
• Subclinical infections may alter baseline physiological parameters without obvious clinical signs