Protozoa - Leishmania, Ciliates, and Drugs

Question 1

Leishmania is classified in the phylum ___ and order ___.

Answer 1

Phylum: Metamnoda. Order: Kinetoplastida

Question 2

What is the common name of the vector for Leishmania?

Answer 2

sandfly

Question 3

What genera of vector transmit Leishmania in the Old World & New World?

Answer 3

Old World: Phlebotomus

New World: Lutzomyia

Question 4

What 2 parasite forms occur during the life cycle?

Answer 4

amastigote & promastigote

Question 5

Inside what cells does the parasite live in humans?

Answer 5

macrophage

Question 6

What is found inside a parasitophorous vacuole?

Answer 6

parasite that fuses with lysosome at low pH

Question 7

By what process does the parasite multiply?

Answer 7

binary fission

Question 8

Why do reservoir hosts make control of parasite difficult?

Answer 8

Rh are dogs and rodents. These are common part of our lives and are not as severely affected as humans to these parasites, makes it harder to spot.

Question 9

What is the treatment for leishmaniasis?

Answer 9

pentostam

Question 10

From what heavy metal is Pentostam derived?

Answer 10

antimony (Sb)

Question 11

What is the mode of action for Pentostam?

Answer 11

inhibition of phosphofructokinase prevents phosphorylation of fructose-6-phosphate to fructose-1,6-diphosphate and inihbits glycosis which leads to parasite death

Question 12

Describe some control strategies for Leishmaniasis.

Answer 12

1. vector control
   Sandfly has short flight range
   insecticide in houses & eliminate low growing bushes
2. protect against bites: insect repellants, bed nets, fly screens
3. control of reservoir hosts: dogs, cats, & rodents

Question 13

What is another name for cutaneous leishmaniasis?

Answer 13

oriental sore

Question 14

Do cutaneous leishmaniasis cause secondary skin lesions?

Answer 14

no

Question 15

Why don’t cutaneous leishmaniasis amastigotes spread throughout the body?

Answer 15

amastigotes cannot grow at core body temp

Question 16

Describe the process of a punch biopsy.

Answer 16

circular blade extends through to subcutaneous fat. cylindrical specimen = examination

Question 17

Describe the process of needle aspiration.

Answer 17

~0.1mL of saline into syringe
insert needle into dermis of active border
move needle back & forth under skin & rotate syringe & apply suction

Question 18

What spp causes mucocutaneous leishmaniasis?

Answer 18

Leishamnia braziliensis

Question 19

Where does the primary skin lesion form in mucocutaneous leishmaniasis?

Answer 19

at site of sandfly bite

Question 20

Name 2 types of secondary lesions in mucocutaneous leishmaniasis & describe the pathology they cause.

Answer 20

1. Chiclero ulcer - lesion on ear
   Mexico & Central America
   Pinna - cartilage poorly vasularized
   weak immune system
   over years pinna erodes
2. Espundia - skin lesions spread & invade mucous membrane
   Central & South America
   nose affected
   long, chronic = serious disfigurement
   distruction of facial cartilage = nose and soft palate eroded
   into larynx & trachea = destroy voice

Question 21

What species causes visceral leishmaniasis?

Answer 21

Leishmania donovani

Kala azar

Question 22

Who were Leishman and Donovan?

Answer 22

discovered agent that causes leishmaniasis. physicans in India

Question 23

Why are amastigotes also called LD bodies?

Answer 23

after Leishman & Donovan

Question 24

Why does the immune system become worn down in visceral leishmaniasi?

Answer 24

increases production of macrophages & other phagocytes to detriment of RBC production
macrophages released when still immature
spleen & liver enlarged = hepatoslepnmagly

Question 25

How is visceral leishmaniasi infection diagnosed?

Answer 25

amastigotes - tissue smears, blood

Question 26

What is the significance of Leishmania-HIV coinfection?

Answer 26

emerging disease - decreases immune resources

Question 27

What is the one species in the phylum Ciliophora that infects humans?

Answer 27

Balantidium coli

Question 28

Is Balantidium coli large or small compared to other protozoans in humans?

Answer 28

largest protozoan parasite of humans

Question 29

What structure in B. coli is lined with coarse cilia?

Answer 29

peristome

Question 30

What structure in B. coli ingests food?

Answer 30

cytostome

Question 31

Why are contractile vacuole unusual in a parasitic organism?

Answer 31

responsible for osmoregulation

Question 32

What are the function of the macronucleus & micronucleus in B. coli?

Answer 32

macronucleus - control trophic activities

micronucleus - reproductive functions

Question 33

What stimulates encystment in B. coli?

Answer 33

dehydration

Question 34

What is the transmission stage of B. coli?

Answer 34

cyst

Question 35

How does hyaluronidase contribute to pathology by B. coli?

Answer 35

digests host intestinal epithelium

Question 36

What types of ulcers can form in the intestine in B. coli infection?

Answer 36

flask shaped ulcers
hemorrage
secondary bacterial infections
necrosis = diarrhea & hysentry = balantidial dysentry

Question 37

How can B. coli infections be treated & controlled?

Answer 37

treated - Metranidazole

control - sanitation

Question 38

Describe various characteristics of an ideal antiparasitic drug.

Answer 38

1. effective
2. less harmful to host than to parasite - no side effects
3. kills all stages w/i host
4. broad spectrum drug (ex: Ivermectin)
5. rapid acting
6. ease of administration - tablets/liquids, few treatments
7. affordable
8. long shelf life - chemically stable, no refrigeration
9. safe for environment

Question 39

How is the use of ivermectin detrimental to the environment?

Answer 39

passes out of host feces = in environment = kills invertebrates in soil and water