Week 8

Question 1

____: An organism that livers either on or inside its host and is reliant on the host for food and shelter.

Answer 1

Parasite

Question 2

Do parasites have membrane bound nuclei?

Answer 2

Yes

Question 3

What are three different types of parasites?

Answer 3

Protozoa, helminths, and ectoparasites

Question 4

How are intestinal protozoa transmitted?

Answer 4

Intestinal protozoa are transmitted when they are shed from the infected person’s intestine, along with feces. Protozoa in the shed feces can gain entry into a new host by way of mouth.

Question 5

List the three different types of hosts.

Answer 5

1) Intermediate hosts: allow for larval development prior to reproduction.
2) Definitive hosts: parasites reach adulthood and reproduction occurs.
3) Dead-end hosts: parasite resides

Question 6

Parasites of the intestines of host: 
1) 
2) 
3) 
Diarrhea, abdominal cramps, and nausea are common symptoms.

Answer 6

1) Entamoeba histolytica
2) Giardia lamblia
3) Cryptospordium

Question 7

Parasites of CNS:
Causes brain abscesses, confusion, coma or even death: 
1) 
2) 
3)

Answer 7

1) Naegleria fowleri
2) T gondii
3) Trypanosoma brucei (African sleeping sickness, from bite of tsetse fly)

Question 8

Parasites of Blood cell:
blood cells can be lysed or poorly functional (anemia). 
1) 
2) 
3) 
4)

Answer 8

1) Plasmodium spp (cause of malaria)
2) Babesia
3) Trypanosoma cruzi
4) Leishmania (WBC like macrophages)

Question 9

Parasites associated with skin irritation, that also enter the body.
1)

Answer 9

Dracunulus medinensis (Guinea worm) chronic skin blisters

Question 10

What is the most common method for evaluation and diagnosis of malaria?

Answer 10

Light microscopy is the most common method for the evaluation/diagnosis of malaria and other protozoal diseases.

Question 11

Ways to test for protozoa parasites:

1) Rapid ____ tests
2) _____
3) ____ antibodies

Answer 11

1) Rapid antigen tests
2) PCR
3) Serum antibodies (though not as useful)

Question 12

Fungi live in colonies called ______.

Answer 12

Mycelia

Question 13

Some fungi are dimorphic: Mold:

Yeast:

Answer 13

Mold in the cold

Yeast in the heat

Question 14

Fungi contain a thick cell wall made up of different groups of polysaccharides and _______.

Answer 14

Proteoglycans

Question 15

What is one of the polysaccharides called within a fungal cell wall?

Answer 15

Beta-glucans

Question 16

What is the enzyme that helps produce beta-glucans? What inhibits (drug type) this enzyme?

Answer 16

Enzyme: beta-1-3-glucan

Inhibited by: echinocandins (caspofungin, micafungin, and anidulafungin) all by competitive inhibition.

Question 17

Are Echinocandins fungicidal or fungistatic?

Answer 17

Fungicidal (they work on the cell wall is why)

Question 18

Can you use antibiotics that target peptidoglycan synthesis of bacteria for fungi?

Answer 18

No, they are ineffective.

Question 19

While our cells contain cholesterol, fungal cells have _____ in their cell membrane.

Answer 19

Ergosterol

Question 20

What two drugs disrupt fungi cell membrane by binding to ergosterol and poke holes in the membrane causing ions to leak out of cell?

Answer 20

Amphotericin B and Nystatin

Question 21

Name the four categories of pathogenic fungi:

Answer 21

1) Cutaneous/superficial mycoses
2) Subcutaneous mycoses
3) Opportunistic
4) Systemic

Question 22

________: native to the southwest region of the United States. This infection is often referred to as Valley fever.

Answer 22

Coccidioides immitis

Question 23

________: Transmitted through inhalation of the mold in nitrogen-rich soil contaminated with bird or bat droppings. Native to Mississippi and the Ohio River valleys, particularly in caves.

Answer 23

Histoplasma capsulatum