Dematiaceous Fungi (PART 2)

Question 1

Fonsecaea

- Microscopic appearance

Answer 1

acrotheca predominates: conidiophores blunt and knotted or club-shaped; conidiophores single or in short chains; Elliptical conidia at tip and along sides of tip

Question 2

Phialophora

- Microscopic appearance

Answer 2

Flask-shaped (urn shaped) phialides with flared collarettes

Question 3

Cladosporium

- Microscopic appearance

Answer 3

Chains of elliptical conidia, branching Conidiophores (usually a contaminant)

Question 4

Cladophialophora bantiana

- Microscopic appearance

Answer 4

very long chains of conidia, little branching

Question 5

Difference between Cladosporium and Cladophialophora

Answer 5

Cladosporium: Contaminant; shorter chains, more branching; does not grow at 40C
Cladophialophora: Neurotropic mold; long chains of conidia, little branching; grows at 40C

Question 6

Exophiala

- Microscopic appearance

Answer 6

Pointed conidiophores with oval conidia;

Question 7

Exophiala

- Plate morphology

Answer 7

slow growth, starts yeast-like then velvety

Question 8

Curvularia

- ________ growth

Answer 8

rapid

Question 9

Curvularia

- Microscopic appearance

Answer 9

• Conidiophores are jagged where conidia attach

- Conidia are 4-celled, swollen central cell (boomerang shaped, transverse septa only)

Question 10

Alternaria

- _________ growth

Answer 10

rapid

Question 11

Alternaria

- Microscopic appearance

Answer 11

Drumstick/snowshoe macroconidia with longitudinal and transverse septa

Question 12

Biporalis

- Microscopic appearance

Answer 12

• twisted conidiophores where conidia are attached

- Conidia are oval and multi celled (“peapods”)

Question 13

Stachybotrys

- Thought to possibly cause “_____ _____ _____”

Answer 13

sick building syndrome

Question 14

Stachybotrys

- Reasons for public concern over mold causing “sick building syndrome”

Answer 14

• Mycotoxins

- mostly allergic reactions in patients (immunocomp at risk)

Question 15

Stachybotrys

- have an affinity for high _________

Answer 15

cellulose (e.g. wallboard)

Question 16

Stachybotrys

- Steps that can be taken to prevent mold overgrowth in homes

Answer 16

• clean with bleach
• find/repare water leaks
• air conditioning or dehumidifiers
• ventilation in bathrooms and kitchens
• clean regularly
• dont carpet bathrooms

Question 17

Microscopic morphology of Stachybotrys

Answer 17

Dark, oval conidia singly or in clusters. Three to ten phialides in an upright whorl.