Clostridium difficile Infections

Study Notes

Clostridium difficile is an obligate anaerobic, gram-positive, spore-forming bacillus.
Known for causing pseudomembranous colitis, a colonic disease associated with prolonged antimicrobial use.
Recently reclassified into a separate genus, Clostridioides difficile.

A significant cause of healthcare-associated infections, particularly common in the Western world.
In India, cases are reported less frequently.

Prolonged Hospital Stay: Spores are abundant in nature and can colonize the colon of hospitalized patients.
Prolonged Antimicrobial Use: Disruption of normal colonic flora increases susceptibility to infection.
- Cephalosporins, such as ceftriaxone, frequently implicated.
- Other antibiotics like clindamycin, ampicillin, and fluoroquinolones also linked to outbreaks.
- All antibiotics, including vancomycin and metronidazole, can risk infection with extended use.

Pathogenesis is toxin-mediated; toxigenic strains are responsible for disease.
Produces two potent exotoxins:
- Toxin A (enterotoxin)
- Toxin B (cytotoxin)
Both toxins disrupt the actin cytoskeleton of epithelial cells, leading to diarrhea and pseudomembrane formation.
Asymptomatic colonization can occur in infants, who lack necessary mucosal toxin receptors.

Suppressed normal flora increases risk, as normal flora helps to resist spore germination.
Advanced age (>65 years) increases vulnerability.
Conditions such as immunosuppression, cancer chemotherapy, and recent gastrointestinal surgeries heighten risk.
Use of gastric acid suppressant medications contributes to risk.
Utilization of electronic rectal thermometers also noted as a risk factor.

A ribotype BI/NAP1/027 has been identified as a hypervirulent strain, producing elevated toxin levels.

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