Protozoa including Giardia Flashcards
What phylum is Toxoplasma, Neospora + Sarcocystis
Apicomplexa
What is a tachyzoite?
Intracellular
Rapidly dividing phase
2 x 6um
What is a bradyzoite?
*Within bradyzoite cyst
*Neural / muscle tissue
*Slow growing phase
*Persistent
What is an oocyst?
*Unsporulated oocyst passed in faeces
*Sporulated oocyst - 2 sporocyst
-4 sporozoites
*12um
What are the definitive host of Toxoplasma gondii?
Cats
What is the life cycle of Toxoplasma gondii?
- Cats infected by ingesting bradyzoite cysts in tissues of prey
- Sexual cycle in SI - unsporulated oocyst in faeces
3.Oocyst sporulate - contaminating environment
4.Infect intermediate host - any warm blooded animal
5.Sporozoite released - cross gut wall, develop into tachyzoites, rapidly replicate = differentiate into bradyzoites that form cysts
What is the life cycle of Toxoplasma gondii in cats?
- Ingestion of prey containing bradyzoite cysts.
- Cyst wall is digested in the stomach and intestines, liberating bradyzoites.
- Bradyzoites invade epithelial cells of the intestine.
- In the enterocytes bradyzoites divide by schizogony giving rise to merozoites.
5 & 6. Differentiate into male and female gametocytes - microgametes and macrogametes. - Fertilization gives rise to an unsporulated oocyst shed with cat faeces
8 & 9. Sporulation occurs and generates two sporocysts with four sporozoites each.
What does toxoplasma cause in cats?
No disease
No clinical signs
How is T. gondii controlled in cats?
No vaccines
Drug not realistic, practical option
How do humans get toxoplasma?
*Tissue cysts in undercooked meats
*Ingesting oocyst contaminated food
What can happen if woman gets infected when pregnant?
Vertical transmission - severe effects to the foetus
* Miscarriage, still born child
* Hydrocephalus
* Convulsions
* Intracerebral calcification
* Retinochorioditis
How is toxoplasmosis in humans controlled?
*Chemotherapy - sulfonamides + pyrimethamine
*reduce risk of infection - oocyst in soil (Unwashed veg)
-cook meat to kill bradyzoite cyst
What are the intermediate + definitive hosts of Neospora caninum?
Definitive = Dogs
Intermediate = dogs + cattle
What does neospora cause in cattle + dogs?
Cattle = abortion
Dogs = neonatal paresis
What are clinical signs of Neospora in young dogs?
- ataxia, hindlimb paresis, loss of reflexes
- ascending paralysis, dysphagia
- hyperextension of hindlimb(s)
What are the clinical signs of Neospora in older dogs?
- CNS disturbances
- abnormal behaviour
- vision defects, seizures
- myocarditis, dermatitis
- pancreatitis
How is Neospora diagnosed?
*Clinical signs
*Serology by IFAT
*Creatine kinase elevation
*Muscle biopsy + tissue aspirates - PCR
How is neospora treated?
*Clindamycin
What are the 2 host life cycles of Sarcocystis?
Prey = asexual reproduction + muscle cyst development (sarcocyst)
Predator = intestinal sexual reproduction + production of mature oocysts
What are the clinical signs of sarcocystis in dogs + cats?
No clinical signs - mild diarrhoea
What happens to cattle if infected with sarcocystis in the third trimester?
Abortion
What is Cystoisospora transmission? and clinical signs?
Transmission = faeco-oral
CS = diarrhoea in kittens / puppies
How is Cystoisospora infection diagnosed?
*History + Clinical signs
How is Cystoisospora infection controlled?
Good sanitation + tx with sulphonamides
What does giardia cause?
Malabsorptive Diarrhoea in puppies
Dehydration
Steatorrhea (greasy stools)
What is the morphology of a giardia trophozoite? Where are they found?
Pear shaped
Bi-nucleated
4 pairs of flagellae
*Attached to intestinal mucosa
What is the morphology of giardia cyst? Where are they found?
*Found in intestinal lumen + faeces
*oval, smooth cyst wall
*8x12um
*Each cyst = 2 trophozoite
What is the life cycle of giardia?
1.Infective cyst ingested by host
2.Excyst in SI - cyst capsule breaks down releasing 2 trophozoites
3.Trophozoite attach intestinal epithelium + multiply asexually by binary fission
4.Multi-nucleated resistant cyst excreted in faeces
What is the pre patent period of giardia?
1-2weeks
How is giardia diagnosed?
Identification of trophozoites/cysts in stool
How is giardia treated / controlled?
*Control = good hygiene - clean drinking water
*Tx = Metronidazole
-Fenbendazole licensed for puppies
Where does Tritrichomonas foetus affect cats/cows?
Bovine repro tract
Feline GI tract
In What species is (Tritrichomonas foetus) commensal? And where in this animals does it exist?
PIGS
*Nasal cavities, Intestines + Stomachs
What does Tritrichomonas foetus cause in cattle?
Abortion + Infertility
What does tritrichomonas foetus cause in cats?
Diarrhoea
Colitis
What is the route of transmission of tritrichomonas foetus?
Faeco-oral
How is Tritrichomonas foetus diagnosed?
*Faecal smears
*Culture from faecal sample
*PCR
How is tritrichomonas foetus treated + controlled?
Tx = ronidazole
