Fungi Part 1

Question 1

What are the two forms of coccidiodes at 25C and 37C?

Answer 1

At 25C it is mold and at 37C it is in the form of spherules.

Question 2

What is the range of histoplasma capsulatum?

Answer 2

World wide

Question 3

How does histoplasma capsulatum spread?

Answer 3

Through the inhalation of spores. They are spread to humans by exposure to birds and bats.

Question 4

Histoplasma capsulatum in the human body

Answer 4

1. Phagocytized by macrophages
2. Calcification in lungs, liver, and spleen
3. Cause acute pulmonary disease
4. Can reactivate and disseminate that can lead to death

Question 5

What are laboratory diagnosis of fungi?

Answer 5

1. Depends upon focus of infection
2. Culture is gold standard at the trade off of time
3. Antigen tests fairly accurate using sputum, urine, and blood
4. May see yeast within macrophages or lesions
5. Yeasts can be acid fast
6. Presumptive ID depends on visualization of broad based yeast
7. Serology not always useful due to cross reactivity & antigen detection can have false positive

Question 6

What is the range of blastomyces and how can a person be exposed to them?

Answer 6

North America and Africa. People can be exposed to them by doing outdoor activities or being careless in the lab.

Question 7

What are conditions or diseases blastomyces can cause?

Answer 7

1. Blastomycosis
2. Gilchrist’s disease
   3.Chicago disease
3. Pulmonary Disease
4. Infect multi-organ in immuno compromised (will double check)
5. Skin is involved in 40% - 80% of cases

Question 8

What is the range of Coccidiodes immitis and how can a person be exposed to it?

Answer 8

1. Southwestern US
2. Traveling…. To South US

Question 9

What can Coccidiodes immitis cause in a human body?

Answer 9

1. Coccidiodomycosis or valley fever
2. Can disseminate

Question 10

Can Coccidiodes immitis be detected with other tests besides culture?

Answer 10

Yes, with the coccidiodin skin test

Question 11

What is the morphology of Coccidiodes immitis at 25C and 37C?

Answer 11

Alternating barrel shape at 25C and spherule at 37C

Question 12

Paracoccidioides brasiliensis range is?

Answer 12

Endemic in Central & South America

Question 13

Paracoccidioides brasiliensis in the human body, what happens?

Answer 13

1. Cause South American blastomycosis or paracoccidioidomycosis. It can be chronic and progressive.
2. Certain strains can have proteases making it more virulent leading to muscle damage
3. Nasal, oropharyngeal lesions, pulmonary dessimination

Question 14

What would Paracoccidioides brasiliensis look like under the microscope?

Answer 14

Septated hyphae in mold form and spherule in yeast form that looks like a mariner’s wheel (multiple daughter yeast at once).

Question 15

What are the three types of infection in aspergillosis fumigatus?

Answer 15

1. Opportunistic - persistent infection in tissue
2. Pulmonary fungus ball - Growth in lung w/ tissue break down because of elastases produced (2 of them).
3. Allergic bronchopulmonary aspergillosis — Immune response to inhaled fungi (spores?)

Question 16

What is the name of the toxin A. Flavus produces?

Answer 16

Aflatoxin