What is the pathogenesis of Cryptococcus neoformans?

What is the pathogenesis of Cryptococcus neoformans?

Cryptococcus neoformans (Cn) is a fungal pathogen, commonly found in urban environments (Tampieri, 2006) that primarily affects immunocompromised individuals through inhalation of spores.

What is the morphology of Cryptococcus neoformans?

Morphology. neoformans is an encapsulated, environmental yeast. Cryptococcus neoformans is a round or oval yeast measuring 4–6 µm in diameter, surrounded by a capsule that can be up to 30 µm thick.

What does Cryptococcus neoformans produce?

Cryptococcus neoformans typically grows as a yeast (unicellular) and replicates by budding. It makes hyphae during mating, and eventually creates basidiospores at the end of the hyphae before producing spores.

What are the virulence factors of Cryptococcus neoformans?

The principal virulence factors of C. neoformans are a polysaccharide capsule, melanin production (5, 6), the ability to grow at body temperature (7), and the secretion of extracellular enzymes (7). These virulence factors confer a selective advantage to C.

What is the pathophysiology of cryptococcal meningitis?

The pathophysiology of cryptococcal meningitis depends on a weakened immune system. The yeast takes advantage of poor immunity to reach the lymph nodes — where it multiplies into many cells. From there, these cells spread and most often affect the nervous system. They grow in the meninges, gradually causing symptoms.

Is Cryptococcus neoformans gram positive?

The cells of Cryptococcus neoformans may appear round with Gram-positive granular inclusion on a pale lavender cytoplasmic background or as Gram-negative lipoid bodies.

Is Cryptococcus neoformans gram-positive or negative?

Does Cryptococcus neoformans produce Pseudohyphae?

In addition to yeast and hyphal growth, C. neoformans can also exhibit pseudohyphal growth.

Is Cryptococcus neoformans Gram positive or negative?

Where is Cryptococcus neoformans found?

C. neoformans lives in the environment throughout the world. The fungus is typically found in soil, on decaying wood, in tree hollows, or in bird droppings.

What is a major virulence factor for the fungal pathogen Cryptococcus?

Iron is a critical cue for Cryptococcus neoformans because the fungus senses iron to regulate elaboration of the polysaccharide capsule that is the major virulence factor during infection.

How does Cryptococcus neoformans evade the immune system?

Evasion of Innate Immune Responses by the Highly Virulent Cryptococcus gattii by Altering Capsule Glucuronoxylomannan Structure. Cryptococcus neoformans causes life-threatening diseases mainly in immunosuppressed hosts such as AIDS patients; C. gattii causes disseminated infections even in healthy hosts.