PMB: p

Question 1

Are Parisites prokaryotes or Eukaryotes?

What are the classifications of eukaryotes?

Answer 1

Eukaryotes

• Protozoa (unicellular)
• Metazoa (multicellular)

Question 2

Where are Protozoa found?

What classes of protozoa is there?

Answer 2

Aquatic enviroments - doesnt have to be water, could be digestive tract of herbevores

1. Ciliates
2. Flagellate
3. Sporozoa
4. Amoebae

Question 3

How do protozoa reproduce?

Answer 3

Reproduction is complicated. They can under go asexual or sexual reproduction

Diviision can occur by fission. bussing, shizogony.

Shizogony is basically multiple fissions - the nucleus under goes multiple divisions and each is used to form a new cell

Question 4

What are special about some ciliates?

Answer 4

The biology of protozoa can be rather complicated. The temptation is to regard them as simple organisms as they are unicellular. However reproduction can be sexual or asexual; division can be by fission, budding or schizogony (multiple fission). In addition, some ciliates have two different kinds of nuclei; a diploid sexual nucleus (micronucleus) containing all the genetic material needed by the cell and polyploid asexual nucleus (macronucleus) containing multiple copies of subsets of the genetic material. In addition, some ciliates have more than one micronucleus present.

Question 5

Are Protozoa harmful?

Answer 5

• Most protozoa are non-virulent (non-harmful).
• In some species protozoa are benefical e.g. in the digestive systems of some herbivores, help to digest fibre
• Some speices of protozoa can be harfmul. The severity of infection depends on intial dose of protozoa and route of entery. Small doses of some protozoa aloow the bos immune system to respond

Question 6

What are potential routes of infection for protozoa?

Answer 6

• Skin acts as barrier to infection
• Oral ingestion provides an entery route
• Cuts in the skin provide an entery route
• Insects bites are also another way to penetrate tthe skin barrier

Question 7

What is required for infection?

What are the problems?

Answer 7

• Physical contact is required for infectino. Either directly - via protozoa or indirectly - via a vector.
• Protozoa conditions are often chronic:
  
  • Last several months
  • Complications arise due to further reinfections

Question 8

What is the most common type of protozoa infection?

Answer 8

• STIs e.g. trichominas vaginals

Question 9

1. Where do infections tend to occur in females?
2. What are symptoms for males and females?

Answer 9

1. In the cervical of the vagina or urethra region
2. Symptoms include but vary of an individual basis (feamle):
   
   • Pain when urinating/ during sexual activity
   • More frequently urinating
   • Vaginal Itching/ burnign
   • bleeding/ spotting
   • Vaginal isharge which is frothy

• Not all females show symptoms
• Many males show no symptoms (asymptomatic)

Question 10

What is the general treatment for STIs?

Answer 10

Metronidazole - a generic inhibitor of DNA replicatino

Question 11

Give an example of a protozoa which causes GI infections

How does this infect a person?

Answer 11

• Cryptosporidium parvum
• Via the faceal-oral route. An infected person excreted the pathogen which ends up in the water source and contaminates it. The water source is untreated and causes infection to a suspetible person

Question 12

What are the symptoms of Cryptosporidium parvum?

How do people recover?

Answer 12

• Severe diaohrrea for 2-7 days
• NAusea, vomitting, dehydration
• MOst people recover with little more needed than rehydration

Question 13

1. What is an example of another GI protozoa?
2. How transmitted
3. What does it do?
4. Incubation period
5. Symptoms

Answer 13

1. Giardia Lamblia
2. This can be trnasmitted from contaminated water or food
3. It has a specific mode of action and attaches to the duodenum and causes localised inflammation of the duodenum
4. Has an incubation period of 1 - 4 weeks
5. Symptoms: water diaohhrea and adombinal cramps

Question 15

Entamoeba histolytica is a protozo:

1. What does it cause?
2. Mechanism?
3. Symptoms

Answer 15

1. Amoebic dysentery
2. Infescts the lumon of the tract - generally the bowel. Leads to ulceration of the mucosal tissue of the epithelial parts of the tract
3. Severe Cramps, colitis, bloody diarrhoea

Question 16

What is the treatment for amoeabic dysentery (entamoeba histolytcia), Giardiasis (Giardia Lamblia) and Trichominas vaginalis

Answer 16

Metronidazole

Question 17

1. What is an example of a blood and tissue infection and the protozoa which causes it?
2. Where is the source of the infection?
3. Where can the protozoa reproduce?
4. Who can get this?

Answer 17

1. Toxoplasma gondii causes toxoplasmosis
2. Main source of infection is uncooked meat or direct handling of cat faceal material
3. Cats serve as a host for replication of the toxoplasma gondii
4. Almost any warm blood animal

Question 18

1. Are cases of toxoplasmosis dangerous?
2. What are the symptoms?

Answer 18

1. Most exposrues are bengin however it tissue invasion occurs there could be a bigger problem. It can invade the lungs, heart, CNS, eyes. It causes cell destruction
2. Fatugue, blindeness, Chills, fever, lymphadenitis

Question 19

1. What is another example of a blood/tissue parasite?
2. What type of parsite is it
3. How is it transmitted
4. What forms are available?
5. Why are these vaailbale

Answer 19

1. Leishmania
2. Intracellular parasite
3. Transmitted by infected female sand flies
4. 2 forms of Leishmania exist
   
   • Visceral (affects ingestion)
   • Cutaneous (attacks skin)
5. Form of disease varies
   
   • Geographical variation
   • species. strain of parasite

Question 20

What does the visceral result of Leishmania entail?

Answer 20

• Results in invasion of reticuloendothelial phagocytes. This causes enlargement of the abdominal organs.
• Treatment is normally with sodium stibogluconate - an antimonial compound

Question 21

1. What is the most problematic protozoa?
2. Where does replication occur?
3. When does reproduction occur
4. What is effected?
5. Symptoms

Answer 21

1. Malari caused by sporozoa plasmodium
2. Uses an intermediate host. Sexual replication occurs here. Asexual replication occurs in the human
3. Reproduction occurs after being bitten by mosquito
4. afects hepatocytes and ethrocytes
5. symptoms
   
   • Periodic fevr - 48 to 72 hr
   • chills
   • headache
   • nausea
   • vomitting
   • abdominal pain

Question 22

Treatment of malaria

Answer 22

• doxycycline
• atovaquone/proguanil
• mefloquine (prophylactic)
• artemisinin