Lecture 4 to 7 Flashcards
What are the main features of the protozoa?
- very small - most animals will have one or more species within them
How do protozoa acquire food and nutrients?
- enter by pores in the cell wall or by formation of vesicles - solid particles engulfed by pseudopodia or wafted by cilia into the cytosome (‘mouth’)
What is the name of the phylum, subphylum, order and family of trypanosoma and leishmania?
Phylum: Sarcomastigophora Subphylum: Mastigophora Order: Kinetoplasdida Family: Tyrpanosomatidae
Describe the structure of Trypanosoma:
Elongate, leaf-like with a single flagellum
What are the two main hosts that are involved in Trypanosoma?
Insects (specifically the tsete fly) and mammals
What is a common feature of all members of kinetoplasdida?
All members have a kinetoplast at the base of the flagellum
Fill in the blanks:
Name the two different types of transmission that occur in trypanosomes:
Salivarian trypanosomes: saliva to the blood or vertebrate hosts, all of these are transmitted via the tsetse fly vector
Stercorarian trypanosomes: faeces of the insect is transmitted to the bite site of the animal (depends on the animal stratching)
What is a symptom of African animal trypanosomosis (AAT) and what is the name of the parasite that causes it?
- T.evansi
- Cause fo surra = weight loss and weakness within cattle
- Involves a fly ingesting trypomastigotes and then the fly transmits it to the blood of a host via metacyclic trypomastigotes
What is the principle cause of dourine within horses?
T. equiperdum:
Results in neurological signs and emanciation
What is the cause of “chagus” disease?
- T. Cruzi
- Acute swelling/redness at the skin infection site
- Chronic symptoms can include eventually heart failure
What are the two basic life stages of Leishmania?
Describe the basic life cycle of Leishmania?
- Sand-fly bites the host and takes up amastigotes in the blood
- Amastigote becomes a promastigote in the sand-fly
- Sand-fly bites another host and the promastigote enters a phagosome
- In the phagosome the sand-fly then becomes a amastigote again
- Proliferates and causes cell lysis and then enters more cells
- Taken up by an insect in the blood again
What is the name of the parasite that causes Visceral Leishmaniasis and what are the basic symptoms of this condition?
- Leishmania infantum
- Second largest parasitic killer in the world
- Affects many internal organs
- Fever and weight loss result, enlargement of liver and the spleen
What are the basic symptoms of cutaneous Leishmaniasis and what is the main parasitic reservoir?
- Lesions at the bite develop into nodules
- Infected dogs are parasite reservoirs
What are the basic symptoms of Mucocutaneous Leishmaniasis?
- Caused by Leishmaniasis Braziliensis-
- Form of cutaneous leishmaniasis
- Affects mucous membranes of nasopharyngeal complex
Why does the family trichomonadidae not require a cyst stage?
Don’t require a cyst stage as they are always in a comfortable environment.
How is trichomonas transmitted?
- drinking water/crop milk
What are the symptoms of tritrichomonas?
- early fetal death and infertility
- cats- diaherrea
- genital tract of cattle- vagina of cows, prepuce of bulls
What are the basic symptoms of Histomonas and where does the parasite occur?
- Extensive and severe necrosis cecum and parenchyma of liver
- Depression, reduced appetite, poor growth, increased thirst
- Occurs in caeca and liver
What are the three different morphological stages of the histomona parasite?
- Amoeboid form- intestinal lumen
- Tissue form- singly or in clusters
- Luminal form- 1-2 flagella
Where does the Giardia parasite infect the host and what are the basic symptoms that are involved?
The symptoms include violent diarrhea and GI stress affecting the duodenum. The morphology of giardia includes 2 nuclei, adhesive disk on the ventral surface, 8 flagella (4 pairs) and a cyst phas exists.
Explain the basic life cycle of the giardia parasite:
- the parasite loosly resembles casper the ghost
- able to transform into a cyst so that it can survive in the outside environment
