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79 Cards in this Set
- Front
- Back
Name 6 genera of Intestinal Apicomplexa
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1. Cryptosporidium
2. Eimeria 3. Isospora (Cystoisospora) 4. Neospora? 5. Toxoplasma 6. Sarcocystis? |
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Monoxenous means?
Gve example of monoxenous parasite (in Intestinal Apicomplexa): |
1 host, host specific
The species usually strictly host specific, using only a single host species e.g. Eimeria and Isospora (Cystoisospora); but sometimes will infect other host undergoing only asexual reproduction? |
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Eimeria has how many sporocysts? how many sporozoites in each sporocyst?
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4 beers each for 2 dollars
4 sporocysts each containing 2 sporozoites (pic shows Eimera's reptilian isolet) |
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Cystoisospora has how many sporozoites?
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2 sporocysts each containing 4 sporozoites
2 beers each for 4 dollars Cystoisospora more expensive... |
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T or F: Merozoites can contain thousands of Schizonts
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False: Formation of Schizonts (which contain thousands of merozoites)
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What protozoan parasite associated with BOVINE Coccidiosis?
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EIMERIA spp.
(E. bovis , E. zuernii ) |
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What are symptom of Winter Coccidiosis ?
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Bloody diarrhea, tenesmus (straining). Rectal prolapses may occur. Secondary bact. enteritis and pneumonia is common sequelae.
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Most common EIMERIA spp.
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E. bovis
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Worldwide distribution; estimated to cost > $70 million annually in production losses. Extending calving due to coccidiosis would cost $60-$70.
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E. zuernii
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Eimeria nonpathogenic in what animals?
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Nonpathogenic species in horses & pigs
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Eimeria Very important pathogen in what spp.?
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cattle & poultry industries.
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Eimeria clinical signs usually in calves of what age?
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usually appears in 4 wk-old calves
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What is the only species of enteric coccidia reported from N. American horses, oocysts very large with thick dark brown wall, appears to be prevalent and relatively harmless?
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only E. leukarti - mostly harmless, large oocysts
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What is the most important species involved in coccidiosis in pigs?
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I. suis
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What is the causative agent of avian coccidia, it is most severe in young chicks, causes enlarged inflammed cecae and bloody cecal contents, diarrhea, reduced weight gain and egg producction?
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E. tenelia
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If cow has recovered from Eimeria, can it be reinfected?
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No, unless immune suppressed e.g. via stress
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Lamma & alpacca Eimeria spp.?
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E. macusaniensis
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How do you diagnose coccidia?
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emonstration of oocysts on fecal flotation
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E. macusaniensis symptoms
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Severely affected animals had signs of lethargy, weight loss, anorexia and diarrhea. Also evidence of: circ. shock, protein loss, renal insuff., bile stasis and hepatic lipidosis
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In rabbits, Liver (E. stiedai) is more important than the intestinal
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True
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CYSTOISOSPORA have how many sporozoites?
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Sporulated oocysts have 2 sporocysts, each with 4 sporozoites.
(2 beers for 4 dollars |
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Species of isospora in dogs
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Four species of Isospora in dogs
Isospora canis is the largest oocyst (36 X 30 µm). Isospora ohioensis, I. neorivolta, and I. burrowsi |
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isospora found where in dog?:?
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All inhabit the small or large intestine
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Hypozoite – occur in __?
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Hypozoite – occur in tissues of paratenic hosts
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What is recommended for all calves aged less than 3 weeks of age and newborns, calves that recieved this were significantly less likely to shed cryptosporidium oocysts?
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halofuginone lactate (halocur)
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CYSTOISOSPORA TWO EXCEPTIONS
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1. extraintestinal stages (hypnozoite = 1 sporozoite) occur in the tissues of paratenic hosts (mice, rats, hamsters, opossum).
2. extraintestinal stages occur in the tissues of the dog, cat and humans (I. belli). |
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how is life cycle of sarcocystis unique?
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asexual stage in intermediate host (prey) and sexual stage is in definitive host
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Neospora is taxonomically and genetically related to ?
What is more likely to cross placental barrier? |
Neospora caninum is easily mistaken for Toxoplasma;
but Neospora more likely to cross placental barrier |
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What is the definitive host of Neospora caninum? What are the intermediate hosts? What is the most common host?
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Dogs are the definitive host of Neospora caninum. Intermediate hosts are herbivores, especially cows.
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Most of Neospora related abortions happen in what term?
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mid to late term abortions
(in bovine btw. 4-8 mo. of gestation) |
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Which cows more likely to abort due Neospora infection?
A. asymptomatic cow with congenital infection OR B. cow infected by ingesting oocysts (horizontal transmission) |
A. Although may be asymptomatic with congenital infection, more like to abort!
~Somehow Neospora maintains low grade infection which becomes reactivated upon pregancy, crossing placental barrier with ease. |
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Is Neospora zoonotic?
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unknown, although antibodies found against parasite, no parasite or clinical signs detected
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How might dog get Neospora infection horizontally (if not congenital infection)?
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Eating a placenta or aborted fetus of dairy cow
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What possible clinical signs / symptoms of Neospora in puppy? (3)
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CNS signs, dermatitis, pneumonia
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What possible clinical signs / symptoms of Neospora in older animal? (4)
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Older dogs
Neural, myocarditis, generalized disease, myositis, dermatitis Dermal Neosporosis more common in older dogs, get ulcers |
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Best way to diagnose neonate calf?
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Get serum, preferably pre-colostrum, before it has gotten antibodies from mother (check this)
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How might dairy cow get infected with Neoplasma horizontally (if not congenital infection)?
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Dogs can pass oocysts if defecate on hay etc, although do not shed a lot Neospora oocysts and difficult to detect
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What tissue of aborted fetus might look to detect Neospora cysts/tachyzoites?
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Brain, heart, occular musc. of eye, maybe liver
(NOT sk.muscle like Sarcocysta) |
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Neospora caninum cysts are (smaller OR bigger) than T. gondii cysts?
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Neospora are smaller
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Equine protozoal myeloencephalitis is caused by what parasite? Sign include lameness, ataxia, excess sweating, and loss of reflex also occur.
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Sarcocystis neurona.
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Identify this parasite. Cats are only def. host; any mammal (even cats) can be intermediate host and only pathogenic in IH.
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Toxoplasma gondii
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Congenitally infected pups may exhibit CNS signs, hind limb paralysis. Hyperextension of the hind limbs. What parasite?
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Neonates with NEOSPORA infection may show CNS signs described here.
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Are horses definitive host for Sarcocystis?
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No, The horse is dead-end (aberrant) host.
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Zoonotic apicomplexa?
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Toxoplasma (cats are true definitive host), Sarcocystis, Cryptosporidium Parvum
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Horse Muscle
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Sarcocystis
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Poultry Feces
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Eimeria
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Ruminant Feces
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Eimeria
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What species SARCOCYSTIS has opossum as definitive host?
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S. neurona
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What are intermediate host for S. neurona? (6)
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many IH: armadillo, skunk, raccoon, sea otter, cat,
horse & marine mammals! serves as a dead end host (not true IH) |
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Worldwide Distribution
Obligatory 2 host / Predator-Prey Life Cycle (canine & feline) Regional Prevalences: High in ruminants, swine & horses |
SARCOCYSTIS
* Predator-Prey Life Cycle |
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SARCOCYSTIS can cause what in horse?
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Equine Protozoal Myeloencephalitis (EPM)
# 1 Cause of neurological signs in horses. |
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T or F: S. neurona is of much importance in equine pathology
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True: horse is not true intermediate, b/c dead end host
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More than 60% cases of Equine Protozoal Myeloencephalitis (EPM) (sarcocystis) seen in what age group?
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60% of the cases are in > 4-yr-olds
but ages range from 2 mo → 19 yr-old |
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Definitive host for Sarco. cruzi
Intermediate host for " |
canine, coyote, red fox, raccoon, wolf
~IH is cattlecattle |
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(EPM) (sarcocystis) seen mostly in what horse breeds? (3)
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Thoroughbreds, Standardbreds, and Quarter Horses affected most often.
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How does predator become infected with Sarcocystis ?
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predator becomes infected when ingest "sarcocyst" in muscle (cardiac or sk.) tisssue of prey (IH)
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Asexual phase of Sarcocystis is in DH or IH?
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intermediate host
(in muscle sarcocyst have brady zoites = slowly diving merozoites) |
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Species of sarcocystis which has human as DH? What are IH?
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sarcocystis hominis (IH is cattle)
sarco.suihominis (IH is pig) |
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Definitive host for Sarco. cruzi, S.equicanis, S.tenella, S.fayeri, S.miescheriana?
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canine, coyote, red fox, raccoon, wolf
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What is IH for S. tenella (in wild dogs, raccon)?
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S. tenella IH is sheep
~DH in wild dogs, raccon |
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Most specific and sensitive test for DIAGNOSIS: EPM? (2)
(Equine Protozoal Myeloencephalitis ) |
Western blot (and IFAT) to detect anti-S. neurona antibodies in CSF (NOT serum), because guess specific aB can cross BBB?
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Differential Diagnosis of EPM (7)
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Neospora
Toxoplasma Sarcocystis spp. Equine Herpes Head or spine trauma Cervical stenotic myelopathy Wobbler’s syndrome |
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Symptoms of EPM
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Variable; asymmetric posterior ataxia, weakness, proprioceptive deficits, muscle atrophy and a wide variety of cranial nerve signs. Severity is directly related to the number of sporocysts ingested.
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Very sensitive and specific for the detection of S. neurona antigen in histopathology prepared tissue samples (e.g., brain and spinal cord)?
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Avidin-Biotin Immunohistochemical Staining (immunohistochemisty)
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3 ways cats can contract Toxoplasma?
Which leads to shortest PPP? |
ingest cyst, oocyst, or tachyzoite
*PPP is 3-10 days for TISSUE CYST -induced infections (occurs in 97% of cats that ingest tissue cysts). Ingesting sporulated T. gondii oocysts or tachyzoites results in oocyst-excreting infection in only 16-20% of cats. |
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TOXOPLASMA gondii - DH ?
Does sexual or asexual reprod. occur in cat? |
CAT
BOTH SEXUAL & ASEXUAL REPRODUCTION = OOCYSTS IN THE FECES |
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Sexual development: in cat takes place in what tissue?
Asexual development? |
Sex. dev. : occurs in intestinal epithelium
Asexual development: Intestinal phase (Merozoites). |
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What is Extraintestinal phase of toxoplasma?
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Extraintestinal phase - Tachyzoites are rapidly-dividing tissue stages. Usually found in the liver, lungs, spleen, or lymph nodes.
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T or F:Toxoplasma tachyzoites can cross the placental barrier (transplacental transmission).
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true
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Toxoplasma Bradyzoites (in cysts) are the slowly dividing tissue stages that are usually found in the ?? (tissues)
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Bradyzoites (in cysts) are the slowly dividing tissue stages that are usually found in the brain, heart, skeletal muscle and eye.
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Facultative intermediate hosts: for toxoplasma?
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Facultative intermediate hosts: Wide range of vertebrates/birds.
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Infective Stages for toxoplasma?
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Sporulated oocysts (10 µm) – only domestic and wild felids shed oocysts
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Symptoms of toxoplasma in human infections ?
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Most human infections are ASYMPTOMATIC; but can have acquired and re-activated toxoplasmosis
--- if immunocompr. Fever, malaise, lymphadenopathy, encephalitis, myocarditis, pneumonitis and retinochoroiditis. |
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Congenital toxoplasmosis leads to ? (5)
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Retinochoroiditis, intra-cerebral calcification, hydrocephalus, convulsions and death.
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Immunity to toxoplasmosis?
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Intestinal immunity is NOT life long.
Immunosuppression with high doses of corticosteroids will cause chronically infected cats to re-excrete T. gondii oocysts. |
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Cats that have previously recovered from a T. gondii infection will re-excrete T. gondii oocysts if they get a primary ____.
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I. felis infection
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T or F: Cats that have I. felis followed by T. gondii inf. will re-excrete T. gondii oocysts if challenged with I felis.
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False; dev. strong immunity to T. gondii NOT re-excrete it if have I.felis first!
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Toxoplasmosis in cattle? sheep?
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RARE; ; usually asymptomatic in cattle
Major cause of abortion; focal placentitis. in sheep |
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A sheep has aborted due Toxoplasma inf.; could you do fecal float to diagnose?
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NO, only in cat!
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