Which virulence factor of Cryptococcus facilitates its spread in the host?

Which virulence factor of Cryptococcus facilitates its spread in the host?

• A. Polysaccharide capsule
• B. Mannose capsule
• C. Melanin pigment
• D. Urease production

Answer: (A)

Dissemination in the host is best explained by the polysaccharide capsule surrounding Cryptococcus. This capsule acts as a strong anti-phagocytic shield, making it hard for immune cells to recognize and engulf the yeast. By reducing opsonization and complement deposition, the capsule allows Cryptococcus to survive inside macrophages and remain in the bloodstream, increasing the chances of seeding distant sites, including the central nervous system. The capsule’s main component, glucuronoxylomannan, also modulates the immune response to favor persistence and spread. Other virulence factors do contribute to the organism’s survival—melanin pigment helps resist oxidative stress, and urease can aid CNS invasion—but they don’t primarily enable the broad dissemination through the host the way the capsule does.

Dissemination in the host is best explained by the polysaccharide capsule surrounding Cryptococcus. This capsule acts as a strong anti-phagocytic shield, making it hard for immune cells to recognize and engulf the yeast. By reducing opsonization and complement deposition, the capsule allows Cryptococcus to survive inside macrophages and remain in the bloodstream, increasing the chances of seeding distant sites, including the central nervous system. The capsule’s main component, glucuronoxylomannan, also modulates the immune response to favor persistence and spread.

Other virulence factors do contribute to the organism’s survival—melanin pigment helps resist oxidative stress, and urease can aid CNS invasion—but they don’t primarily enable the broad dissemination through the host the way the capsule does.