Mycology and Parasites

Question 1

What are the two ways that fungi can be classified?

Answer 1

As a mold (fuzzy form) or a yeast (pasty form)

Question 2

What is the predominant form of metabolism for fungi?

Answer 2

Most are saprophytic

Question 3

How is an immunological response to fungi mitigated?

Answer 3

Via Th1 mechanisms; however there is little memory component that develops after resolution of infection

Question 4

What are hyphae?

Answer 4

Tubular branching filaments that are often nucleated

Question 5

What are septae?

Answer 5

Porous cross walls across hyphae; most pathogenic fungi are septate

Question 6

What is mycelium?

Answer 6

A mass or may of hyphae

Question 7

What are zygomycetes and how common are their infections?

Answer 7

Molds with aseptate hyphae and sporangiospores; members include Mucor, Rhizopus, and Absidia. They tend only to be advantageously infectious

Question 8

What are conidia? How do they appear in microsporum, trichophyton, and epidermophyton?

Answer 8

Asexual reprductive structures on condiophore stalks
micro=macroconidia with spikes
Trichophyton=macroconidia without spike
Epi=clubbed macroconidia

Question 9

What are arthroconidia?

Answer 9

Thickened septate hyphae that can be infectious

Question 10

How are yeasts described?

Answer 10

Unicellular spherical or elliptoid fungal cells that bud

Question 11

What are clamydospores?

Answer 11

Thick walled spherical conidia at the end of hyphal cells

Question 12

What are pseudohyphae?

Answer 12

Elongated blastoconidia

Question 13

What is a germ tube?

Answer 13

An elongated bud in the serum from yeasts

Question 14

What is meant when a fungus is dermataceous?

Answer 14

Cell walls contain melanin

Question 15

What are the cell walls of fungi made of?

Answer 15

Chitin, glucan, mannan, and chitosan

Question 16

What types of fungi cause superficial infections and how does the immune system respond?

Answer 16

Tinea versicolor; minimal if any response occurs

Question 17

What types of fungi cause dermatophyic infections and how does the immune system respond?

Answer 17

Ringworm, Th1 response

Question 18

What types of fungi cause subcutaneous infections and how does the immune system respond?

Answer 18

Sporotrichosis; Th1 response

Question 19

What types of fungi cause deep seated infections, where are they found, and how does the immune system respond?

Answer 19

Histoplasmosis, in midwest, Th1
Coccidiomycosis, in southwest, Th1
Blastomycosis, in wooded areas, Th1
Paracoccidiomycosis, in South America, Th1

Question 20

How do infections from yeast happen?

Answer 20

They are largely opportunistic and either emerge from immune failure or antibiotic treatment

Question 21

How does cryptococcus appear and function in infection?

Answer 21

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

Question 22

What are the main members of parasitic infection?

Answer 22

Helminths (nematodes, cestodes, trematodes) and protazoa

Question 23

How does the immune system respond to the main members of parasitic infection?

Answer 23

Helminths are typically countered by profound hypersensitivities mitigated by eosinophils; protozoa are targeted by Th1 responses

Question 24

What diseases fall under the mastigophora family and what is their identifying feature?

Answer 24

Flagella

Leishmania, trypanosoma, giardia, and trichomonas

Question 25

What disease falls under the ciliophora family?

Answer 25

Balantidium coli

Question 26

What diseases fall under the sarcodina family and what is their identifying feature?

Answer 26

Pseudopodia

Entamoeba, acanthamoeba

Question 27

What parasites are in the apica complexa family?

Answer 27

Plasmodium, Isospora, Cryptosporidium, and toxoplasma