Lecture 12 A - Fungi

Question 1

____ are single cell organisms that undergo asymmetric division or fission. They contain _____ in their membranes, which is similar to human cholesterol. They also contain a cell _____ comprised of Mannans, Chitin, and _____, which is a drug target.

Answer 1

Yeasts

Ergosterol

Wall

Glucans

Question 2

There are essentially 3 ways to treat yeast infections.

1. perturb membranes using ______ B, which forms a pore in ______ within the yeast cell membrane.
2. Inhibit ____ biosynthesis –> both Terbinafine and _____ inhibit this, but do so at different steps in the synthesis pathway.
3. Inhibit cell wall synthesis –> _____ inhibits _____ synthesis (an important cell wall component.)

Answer 2

Amphotericin B

Ergosterol

Ergosterol

Azoles

Echinocandin

Glucan

Question 3

Tinea pedis is the causative agent for ______, and uses _____ as a nutrient source. It is considered a _____ mycoses.

Answer 3

Athlete’s Foot

Keratin

Cutaneous

Question 4

S. shankii is the causative agent for _______ (a subcutaneous mycoses.) It is a ubiquitous fungi, found especially in soil, decaying vegetation, and plant surfaces (hence its nickname “_____ _____ disease.”

Answer 4

Sporotrichosis

Rose Picker’s disease

Question 5

S. shankii is a _____ fungi, meaning it can take the yeast or mold form. In the body, it typically takes on the ____ form, while in the wild it takes on the ____ form.

Answer 5

Dimorphic

Yeast

Mold

Question 6

S. shankii infection can lead to a granulomatous _____ at the puncture site, and may produce secondary lesions along the draining ____. Treatment involves ____ or ____ B.

Answer 6

Ulcer

Lymphatics

Azoles

Amphotericin B

Question 7

H. capsulatum is the causative agent for _______. This fungi grows in ____ droppings. It is also a _____ fungi, exhibiting mycelia at ____ temp and takes on a _____ morphology at body temp. The mycelia form produces micro and macro-_____ that are able to be aerosolized and enter the lung. There, they are phagocytosed and convert to the yeast form, leading to intracellular infection. It is treated with Amphotericin B

Answer 7

Histoplasmosis

Bird

Dimorphic

Ambient

Yeast

micro and macro-Conidia

Question 8

C. albicans is considered an ______ pathogen, and causes Candidiasis. It is part of the normal flora. It is ______ in morphology (can be yeast, exhibit pseudohypha, or hypha.) It presents in the mouth as oral _____, and typically causes pathology in mucous membrane lined areas of the body. It is treated with Fluconozole or echinocandin.

Answer 8

Opportunistic

Pleiomorphic

Thrush

Question 9

Cryptococcus neoformans is the causative agent for cryptococcosis. It is a _____ yeast (mycelia and yeast.) It is only of the mycelia morphology during its ____ stage. The yeast cell morphology has a ____ (this is the infectious form.) It must have BOTH virulence factors to cause disease. The first is its _____ (which prevents phagocytosis), and the other is _____.

Answer 9

Dimorphic

Sexual

Capsule

Capsule

Melanin

Question 10

C. neoformans grows in _____ droppings, and colonies are fast-growing _____ colonies. It is a _____ intracellular pathogen. infection occurs via _____ of spores (or dehydrated yeast cells) into lungs. It can cause skin infections or ____ (though it typically only infects immunocompromised individuals.) It is treated with Fluconozole or _______ B.

Answer 10

Pigeon

Mucoid

Inhalation

Meningitis

Amphotericin B