Mycology and Parasites Flashcards
What are the two ways that fungi can be classified?
As a mold (fuzzy form) or a yeast (pasty form)
What is the predominant form of metabolism for fungi?
Most are saprophytic
How is an immunological response to fungi mitigated?
Via Th1 mechanisms; however there is little memory component that develops after resolution of infection
What are hyphae?
Tubular branching filaments that are often nucleated
What are septae?
Porous cross walls across hyphae; most pathogenic fungi are septate
What is mycelium?
A mass or may of hyphae
What are zygomycetes and how common are their infections?
Molds with aseptate hyphae and sporangiospores; members include Mucor, Rhizopus, and Absidia. They tend only to be advantageously infectious
What are conidia? How do they appear in microsporum, trichophyton, and epidermophyton?
Asexual reprductive structures on condiophore stalks
micro=macroconidia with spikes
Trichophyton=macroconidia without spike
Epi=clubbed macroconidia
What are arthroconidia?
Thickened septate hyphae that can be infectious
How are yeasts described?
Unicellular spherical or elliptoid fungal cells that bud
What are clamydospores?
Thick walled spherical conidia at the end of hyphal cells
What are pseudohyphae?
Elongated blastoconidia
What is a germ tube?
An elongated bud in the serum from yeasts
What is meant when a fungus is dermataceous?
Cell walls contain melanin
What are the cell walls of fungi made of?
Chitin, glucan, mannan, and chitosan
What types of fungi cause superficial infections and how does the immune system respond?
Tinea versicolor; minimal if any response occurs
What types of fungi cause dermatophyic infections and how does the immune system respond?
Ringworm, Th1 response
What types of fungi cause subcutaneous infections and how does the immune system respond?
Sporotrichosis; Th1 response
What types of fungi cause deep seated infections, where are they found, and how does the immune system respond?
Histoplasmosis, in midwest, Th1
Coccidiomycosis, in southwest, Th1
Blastomycosis, in wooded areas, Th1
Paracoccidiomycosis, in South America, Th1
How do infections from yeast happen?
They are largely opportunistic and either emerge from immune failure or antibiotic treatment
How does cryptococcus appear and function in infection?
Looks like a bacterium–has a large capsule around it. Appears in cases of severe immune compromise (HIV) and is a predominant cause of death in sub-Saharan HIV cases
What are the main members of parasitic infection?
Helminths (nematodes, cestodes, trematodes) and protazoa
How does the immune system respond to the main members of parasitic infection?
Helminths are typically countered by profound hypersensitivities mitigated by eosinophils; protozoa are targeted by Th1 responses
What diseases fall under the mastigophora family and what is their identifying feature?
Flagella
Leishmania, trypanosoma, giardia, and trichomonas
