Dimorphic fungi

Question 1

What is the defining feature of dimorphic fungi?

Answer 1

they have the ability to grow as both yeasts and molds, depending on their conditions

Question 2

Dimorphic fungi can be acquired by the ________ of ________ spores from soil. They can cause ________ mycoses.

Answer 2

inhalation
airborne
systemic

Question 3

Dimorphic fungi that produces white cottony colonies which turn brown with age.

Answer 3

Histoplasma capsulatum

Question 4

What disease does Histoplasma capsulatum cause?

Answer 4

Histoplasmosis

Question 5

What is distinctive of Histoplasma capsulatum?

Answer 5

tuberculate macroconidia (large spores with tubercles)

Question 6

How is Histoplasmosis acquired?

Answer 6

acquired by inhalation of spores from soil heavily contaminated with bird or bat droppings

Question 7

Histoplasmosis is usually ____-______, but commonly causes ______ of the lungs.

Answer 7

self-limiting

scarring

Question 8

Why can histoplasmosis present as X-ray diagnostic dilemmas?

Answer 8

Can be a diagnostic dilemma since it leaves scars, esp. if predisposed for lung tumours (e.g. 20 pack year smoking history)

Question 9

Histoplasmosis can disseminate into the __________ system (liver, spleen, bone marrow) and is the only ____________ fungus.

Answer 9

reticuloendothelial system

intracellular

Question 10

What is the only intracellular fungus?

Answer 10

Histoplasma capsulatum

Question 11

Most dangerous and most infectious of all fungi.

Answer 11

Coccidioides immitis

Question 12

Young colonies appear moist and seem to adhere to agar, but with age, develop a cottony appearance resembling spider webs

Answer 12

Coccidioides immitis

Question 13

How does Coccidioides immitis grow spores?

Answer 13

Right in the hyphae - arthroconidia (alternating barrel-shaped)

Question 14

Coccidioidies produces a common infection in the desert areas. What is it?

Answer 14

Commuity-acquire San Joaquin pneumonia (sometimes called valley fever)

Question 15

Coccidioides immitis can disseminate where?

Answer 15

Bone and CNS (meningitis)

Question 16

Coccidioides is common where?

Answer 16

SW USA

Question 17

What are some areas that are SW in the US?

Answer 17

Arizona

Question 18

This fungi is the major exception to inhalation acquisition.

Answer 18

Sporothrix schenckii

Question 19

Where do most people get Sporothrix schenckii infection from?

Answer 19

rose thorns

Question 20

Chronic skin and lymphatic infection which is typically associated with gardening injuries, particularly from rose thorns.

Answer 20

Sporotrichosis

Question 21

In culture, the conidia of Sporotix is arranged how?

Answer 21

in rosettes

Question 22

What is the presentation of sporotrichosis on the skin?

Answer 22

Ropy lymphadenopathy
lymph nodes flare up and sometimes ulcerate along the arm
(easy diagnosis)