MICROBIOLOGY

• Spore-forming, anaerobic, Gram-positive rod.
• Produces toxins A and B, which bind to specific receptors in colon. Toxins attack Rho proteins, disrupting actin formation and causing cell death.
• Studies show that toxin B, not toxin A, is essential for virulence.
• Spores contaminate hands and hospital environment. Alcohol and other antiseptic hand rubs may be ineffective in killing spores. Hand-washing physically removes spores.
• A hypervirulent strain (NAP1/B1/027) produces higher levels of toxins A and B and is associated with fluoroquinolone resistance, more severe disease, and higher mortality.