Week 3 - Microbiology Fungal Structure

Question 1

General characteristics of fungi?

Answer 1

Eukaryotic
Have cell walls for protection
Ergosterol is dominant memrane sterol rather than cholesterol
Require preformed organic compounds for growth

Question 2

What are 3 types of fungi? which cause disease?

Answer 2

Yeast
Mold
Mushrooms - just produce toxin, not disease

Question 3

Yeast

Answer 3

Single cell fungi
Reproduce by budding (blastoconidia)
Some strains produce pseudohyphae (candida)

Question 4

Molds

Answer 4

Grow in filamentous forms called hyphae
Many Species produce cross walls of hyphae called septa
Nonseptate hyphae do exsist
Masses of hyphae are called mycelia

Question 5

Dimorphic Fungi

Answer 5

Exist as yeast or yeast like forms and filamentous forms
Form is controlled by the environmental conditions (temp and nutrients)
Yeast form found in the BODY and filamentous form in ENVIRONMENT (lab culture)

Question 6

What is filamentous form of Dimorphic fungi?

Answer 6

The form of dimorphic fungi in the lab

In BOCY it is the yeast form of dimorphic fungi

Question 7

Spores

Answer 7

Conidia
Arthroconidia
Blastoconidia

These are of diagnostic value for the identification of some fungi - ‘barrel shaped’ arthrospore of Coccidodes immitis

Question 8

Arthroconidia

Answer 8

Spores formed from joints in hyphae then fragmented

Question 9

Blastoconidia

Answer 9

Spores of yeast cell buds

Question 10

Parasites

Answer 10

Protizoa and Worms

Question 11

Protizoa

Answer 11

Single cells
Exist as trophozoites (motile form)
Exists as cysts (resting stage)
Some move by flagella (giardia)
Some move by Cilia (Balantidum)

Question 12

Worms

Answer 12

Trematodes (flukes)
Cestodes (tapeworms)
Nematodes (roundworms)

Infection of worms usually involves ingestion of larval or cyst forms

Question 13

Ergosterol

Answer 13

Dominant membrane sterol in fungi rather than cholesterol

Question 14

Conidia

Answer 14

Asexual spores of molds

Question 15

Trematodes

Answer 15

Flukes

Question 16

Cestodes

Answer 16

Tapeworms

Question 17

Nematodes

Answer 17

Roundworms

Question 18

Hphae

Answer 18

Filamentous forms of mold

Question 19

Mycelia

Answer 19

Masses of hyphae (molds)

Question 20

Septa

Answer 20

Cross walls of hyphae (molds)

Question 21

What are two forms of protozoa?

Answer 21

Trophozoites - motile form

Cysts - Resting form