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Protista
one celled organisms
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Flagellates
- Sarcomastigophora
- contains at least one flagellum during trophozoite form
- live in fluid medium (CSF, blood, etc.)
- pear shaped
- can be greatly pathogenic
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Giardia spp.
- most commonly misdiagnosed, underdiagnosed and overdiagnosed
- two forms can be found in feces
- trophozoite - motile stage in small intestines
- cyst - resistant stage for environmental transmission
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- Trophozoite form of Giardia spp.
- Flagellate
- 4 pairs of flagella
- 2 nuclei look like eyes
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- Giardia cyst. resistant stage
- may appear in the feces one week after infection
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Tests used to diagnose Giardia spp
- Direct Smear: Lugol's idoine stain or New Methylene Blue stain to examine for trophozoites
- Fecal Flotation: Zinc Sulfate, Lugol's Idoine, New Methylene Blue
- Giardia Antigen Tests: ELISA
- PCR: (polymerase chain reaction) - DNA test
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- Tritrichomonas foetus
- Flagellate
- REPORTABLE
- causes spontaneous abortion and infertility
- diagnosis from fluids of aborted fetus, uterine discharge, vaginal or preputial wash
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Bull breeding soundness exam
- prepuce is flushed with 0.9% NaCl and examind for moving organisms
- Incubated on media. Positive at 2 days, but may take 6-8
- Negative at day 10
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Tritrichomonas foetus in cats
- Sarcomastigophora - Flagellate
- fecal oral transmission
- typically cats under 2 years of age
- chronic diarrhea, difficult to diagnose and treat
- best test is PCR
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Amoebae
- Sarcomastigophera
- move via pseudopodia or "false feet"
- two forms: motile trophozoite, resistant cyst
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- Entamoeba histolytica
- left: Trophozoite (single nucleous, small endosome)
- Right: cyst (multiple nuclei)
- Amoebic dysentry in humans
- motile trophozoite (feeding stage) and cyst stage
- diagnosis on fecal float, zinc sulfate, direct smear
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Ciliophora
- Ciliates
- covered with tiny short hairs called cilia
- two forms: motile trophozoite, resistant cyst
- two nuclei: macronucleus and micronucleus
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- Balantidium coli
- Middle: Trophozoite
- Right: cyst
- Ciliophora - Ciliates
- not pathogenic to pigs
- diarrhea in dogs
- pathogenic to humans via ingestion of cyst
- ciliated with large kidney shaped macronucleus
- fecal flotation and fecal smear of fresh diarrheic feces
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- Ichthyophthirius multifiliis
- Ich
- Ciliophora - Ciliates
- infects skin, gills, fins, and eyes of fish
- can form whtie spots just below the skin
- diagnosis by observation or skin scrape
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Apicomplexa - Coccidia
- Coccidians, piroplasms, and malarial organisms
- Most diverse and complicated
- epithelium of intestines, blood cells, tissues
- internal locomotive organelles
- move via undulations
- shape - banana, comma, boomerang
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- Cystoisospora spp
- [formerly Isopora spp.]
- Coccidiosis = clinical syndrome
- common in kittens and puppies, also in pigs
- diagnosis on fecal float - oocyst in fresh feces
- prepatent period is 7-14 days
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Coccidiosis
- clinical syndrome of Cystoisospora
- common in kittens and puppies, also in pigs
- diagnosis on fecal float -- oocyst in fresh feces
- PPP 7-14 days
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Toxoplasma gondii
- Apicomplexa - Coccidia
- toxoplasmosis - ZOONOTIC
- intestinal coccidian of cats
- felids only known definitive hosts
- any warm-blooded animal can be paratenic host
- ingestion of prey that contains cysts
- ingestion of sporulated oocysts from feces
- Oocysts shed 3-10 days after ingesting bradyzoites
- Sporulated oocyst becomes infective in 1-5 days
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Diagnosis of Toxoplasmosis in Cats
- Blood tests - IgM, IgG, PCR
- oocysts best detected by centrifugal fecal flotation wit hsheathers sugar solution
- appearnce similar to other oocysts
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Toxoplasmosis in Humans
- Zoonotic
- undercooked meat
- unpasteurized goat milk
- contaiminated hands/cooking surfaces
- unwashed vegetables
- ingestion of sporulated oocysts from cat feces (rare)
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Oocysts of Toxoplasma gondii
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Cryptosporidia spp
- Cryptosporidiosis
- Apicomplexa - Coccidia
- in small intestine of cats, dogs, cattle, sheep, pigs, goats, birds, rodents, reptiles, wild animals
- diagnosis: very small oocysts on fecal flotation or fresh acid-fast stained smears
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Cryptosporidia spp. : cryptosporidiosis "Crypto"
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Zoonosis of Cryptosporidium spp.
- Cryptosporodium parvum
- calf feces
- most frequent case of waterborne disease in US
- fertilizing salad vegetables with manure
- contaminated food handlers
- most are self-limiting.
- no treatment
- chronic cases in AIDs patients
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- Eimeria leukarti
- Apicomplexa - Coccidia
- horses
- large and dark brown
- GI tract
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Eimeria spp.
- Apicomplexa - Coccidia
- Ruminants, horses, rabbits, mice, rats, guinea pigs
- GI tract
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- Eimeria bovis
- Apicomplexa - coccidia
- micropyle present
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Sarcocystis neurona
- Sarcocystis
- Apicomplexa - coccidia
- infects spinal cord of horses
- causes Equine Protozoal Myeloencephalitis (EPM)
- Ataxia, weakness, muscle wasting
- Diagnosis on histopathology
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- Sarcocystis neurona
- Equine protozoal myeloencephalitis
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Babesia canis
- Apicomplexa - intercellular parasite
- canine piroplasm
- intracellular parasite of RBCs
- spread by tick Rhipicephalus sanguineus
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Babesia bigemina
- Apicomplexa - intercellular parasite
- RBC parasite of cattle
- tick carrier R. annulatus
- reportable disease
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Babesia equi and Babesia caballi
- Apicomplexa - intercellular parasite
- RBC parasite of horses
- equine piroplasm
- spread by Dermacentor tick
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Cytauxzoon felis
- Apicomplexa - intercellular parasite
- RBC parasite of cats
- Ringform piroplasm
- spread by Dermacentor tick
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Haemoproteus spp
- Apicomplexa - intracellular parasite
- in RBCs of birds
- can cause death
- sausage shaped
- intermediate hosts are Culicoides sp. and Chrysops sp
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Leucocytozoon spp
- Infects WBCs primarily
- Greatly distorts cell
- spread by Simulium sp
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Plasmodium spp
- Apicomplexa - Intercellular parasite
- avian malaria
- mosquito is intermediate host
- developmental stages in spleen, liver
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Sugar solution (Sheather's)
- Doesn't float as many eggs as sodium nitrite,
- sticky if spilled
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Sodium nitrite (Fecasol)
- most efficient,
- can form crystals and deform eggs if left to sit too long
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Magnesium sulfate
- epsom salts
- inexpensive
- forms crystals
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Saturated sodium chloride
- not generally recommended
- corrodes equipment
- distorts eggs
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