Acute versus chronic, latent & slow virus infections
most human viral infections are acute, with virus cleared from by specific
some viruses cause chronic infections, where infectivity persists for long
time, with or without s
2. All other molds - have common or frequent cross walls (i.e.
septate hyphae) and are generally smaller in diameter (2-3 m),
compared to the Zygomycetes.
Beyond this difference in branching, septation and size, the hyphae from
different molds are mostly
IV. Fungal Metabolism
Fungi play an important role in the decomposition and recycling of carbon and nitrogen
from dead organic material. Thus, they will be found readily associated with dead
organic matter, soil, etc. A few species can utilize live organi
c. Conidia structure (single-celled vs multi-cellular)
- most molds produce conidia that are single-celled (of different
size, shape and color),
- some species always produce multi-cellular conidia (of
different size, shape and color characteristic of the
VI. Fungal Diseases (categories may overlap in some fungal diseases)
A. Allergies - allergic reactions to airborne fungal spores are the most
common pathologies associated with fungal exposure.
Each species has unique antigens. May be a reaction to
Cryptococcus is the genus name for the yeast phase of a more recentl y
characterized basidiomycete filamentous fungus.
population of over 37 different species of Cryptococcus in the environment,
only a f
I. Distinctive Features / Virulence Factors C. neoformans (and C. gattii)
A. Growth and Reproduction
1. For many years C. neoformans was considered only a yeast that
divided asexually via budding, but in 1976 the sexual stage was
discovered (see figure).
Habitat / Transmission / Epidemiology
A. Habitat - Growth of the entire life cycle in the environment in soil or
decaying trees and other
organic material. Pigeon droppings (nutrient?) stimulate the growth of C.
B. Transmission - Human dis
3. Presentation generally with fever, dyspnea, malaise, cough
with scant sputum. The presentation may look like and could be
confused with Pneumocystis pneumonia (PCP)
4. The disease from var. neoformans and var. grubii may become latent
(dormant) in the
I. Fung al C las sifica tion
Fun gi are classified according to the structure s in w hic h sexual spores are produce d . T he c onditions for
m ating and sexual reproductio n take place under very special cond itio ns found in nature. T he se sexual