Fichas
Protozoa
Fichas del conjunto (30)
- 1Types of protozoansAmoebae
Ciliates
Flagellates
Apicomplexans: all parasitic - 2TrophozoiteActive feeding stage
- 3AmoebaeHave a simple lifecycle
Pseudopodia for movement and engulfing food into vacuoles
Reproduction via binary fission
Cyst stage: infective to host, resistant in the environment and contain several nuclei - 4Entamoeba histolyticaLarge intestine of humans, dog, cat, pig and rats
Faecal-oral transmission
Mainly a problem in tropical places affecting young and naive animals
Fatal infection if liver abscesses formed via portal blood system. - 5Naegleria fowleriFree living in hot pools, opportunistic pathogen
Causes meningoencephalitis. Invasion from nose to brain via cribiform plate and olfactory nerve - 6CiliatesCommon in the rumen
Balantidium coli:
In the colon of pigs, humans and primates
Usually commensal
If they invade the colon they can ulcerate the colon and form a cyst that is infectious. Has a large nucleus. - 7FlagellatesTrypanosomes
Spread via insect bites
Extracellular, mostly in the blood stream
Single large flagella
Giardia
Intestines of healthy animals
Clinical signs: diarrhoea - 8Giardia morphologyTrophozoite:
2 nuclei and medial body with large ventral sucker
Cyst:
Infective state
cyst wall encloses partly divided organism with 4 nuclei - 9Trichomonas foetus morphology and reproduction3 forward flagella
1 undulating membrane
binary fission reproduction - 10(Tri)Trichomonas foetus diseaseOccurs in genital tract (prepuce) of bulls but causes no disease. Chronic carriers
When mating with a naive cow they infect the vagina and multiply. They invade the uterus and placenta resulting in abortion 6-8 weeks post mating
Cows recover and become immune
Can cause Large bowel diarrhoea in cats - 11Apicomplexans (coccidia)Eimeria sp. in ruminants
Isospora sp. in cats and dogs
Infection via direct contact
Intestinal, intracellular parasite leading to cell death
Complex lifecycle - 12Sporulation of oocystOocysts develop outside the host, released into the environment
One sporont becomes 8 sporozoites
Sporulated oocysts are infective - 13SchizogonyAsexual reproduction
Sporozoite infects cell
The nucleus divides repeatedly
Each nuclei then acquires its own cytoplasm and cell wall forming a schizozoite
First generation scizozoites form their own generations - 14Male gametogeny2nd generation schizozoite infects host cell forming a microgametocyte
Microgametes are released from the host cell - 15Female gametogenySecond generation schizozoite infects host cell, forming a macrogametocyte with a macrogamete
Microgamete fertilises the macrogamete forming an oocyst which is released - 16Apicomplexan parasitesCryptosporidium
Toxoplasma gondi - 17CryptosporidiumIn domestic animal neonates <10 days old
Mostly a problem in calves
Zoonotic
Oocysts in faeces are immediately infective
Life threatening for HIV patients - 18Toxoplasma gondiiIndirect transmission between cats (DH) and prey animals (IH)
Known to cause abortion in sheep, pigs and humans. Most common parasite in developed countries - 19Toxoplasma gondii infectionInfects small intestine and oocysts released in faeces
In other animals it can break out of the gut and infect other tissues forming cysts
Ingestion of an oocyst by a rat, sheep or human results in the invasion of cells and rapid multiplication in tissues followed by cyst formation - 20Development in the IHSporozoite infects cell
Undergoes rapid division
Forms Tachyzoites
Tachyzoite infects cell
Undergoes slow division forming bradyzoites in a cyst (brain, eyes, heart etc) - 21Toxoplasma gondii and foetusesOrganism passes to the foetus where it divides unchecked
It damages the placenta and foetal nervous system. Can result in abortion and congenital infection and brain damage - 22Toxoplasma gondii human riskInitial infection causes a mild flu
Cat and sheep faeces are a source of infection
Has links to psychosis and schizophrenia
Dangerous for people with HIV/AIDS - 23VaccineLive vaccine with attenuated tachyzoites
For sheep only - 24Neospora caninumAbortion in cattle via pre-natal infection
Some hind limb paralysis and paresis in dogs
Some evidence of abortions in sheep
Not in humans - 25Neospora canimum lifecycleDH is dogs
Produce unsporulated oocysts in faeces (few)
Not known if dogs can shed again if reinfected
Congenital infection suspected from tachyzoite infection of placenta
Can cause abortions or a congenital infection - 26EpidemicIntroduction to a naive herd via a dog shedding oocysts
Abortion storms - 27EndemicCongenital transmission maintains infection
- 28Infection in dogsClinical disease in puppies: within a few weeks from birth they get weakness and hind limb paralysis from spinal lesions
and neurological signs
Can be treated with early intervention
Have high neospora antibodies
Bitches and repeatedly infect litters - 29Theileria clinical signsRecumbent
severely depressed
Scant faeces
Yellow third eyelids or very pale
On necropsy: pale tissues, thin and translucent blood but normal urine - 30Theileria lifecycleTick transmission
No transoviarian transimission
Multiplication in leukocytes then movement into RBC
Once in the tick it forms gametocytes
3 host tick
Información
- Descripción
- Infectious disease Fichas sobre Protozoa , creado por Kelly Scott el 13/07/2020.
- Creado por
- Kelly Scott
- Visitas
- 1
- Valoración