Cloakie 4

Question 1

Coccidia - what are they?

Answer 1

Obligate intracellular parasites

• largest group of the phylum known as Apicomplexa
• Infect mammalian intenstinal tracts
• Complex life cycle
  e. g. cryptosporiddium

Question 2

Cryptosporiddium - life cycle and disease?

Answer 2

Present in water supplies
Infect young, old and immune compromised, cause diarrhoea, fever, cramps
- Live just under intestine epithelial cell membrane but extracytoplasmic
- Oocysts fully formed when expelled from hosts - immediately infectivhe

Question 3

Toxoplasma gondii - life cycle and disease?

Answer 3

Sexual cycle takes place in epithelium of cats
- Once ingested, exists as tachyzoites, then develops into tissue cyst bradyzoites after 14 days
- Can get it from cat shit as oocysts or dirty old animal meat you haven’t cooked properly
Asexual reproduction in anything but cats as tachyzoites
- Mild fever in humans unless immunocompromised results in encephalitis (brain swelling)

Question 4

Plasmodium (vivax) (falciparum) (malariae) - life cycle, vector and disease?

Answer 4

• 5 species infect man, vivax most common
• Complex sexual and asexual cycle, obligate requirement for 2 hosts
• F Anopheles mosquito vector, ingests gametocytes, sexual rep. in stomach
• sporozoites in saliva infect new host
• Asexual + gamete production in humans