Parasitology Flashcards

1
Q

In what ways do protozoan parasite groups differ?

A
  1. Locomotion
  2. Reproduction
  3. Location in host
  4. Life cycles
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2
Q

T/F Protozoa are single celled, host specific organisms that can transform stages in final host

A

True

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3
Q

What two groups can Phylum Apicomplexa be divided in to

A

Coccidia type (GI Tract)
Hemosporozoa (hemoparasites)

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4
Q

What are important features of coccidian parasites?

A

-Undergo sexual and asexual repro and are mostly GI parasites
-Direct and indirect lifecycles
-Host specific
-Diarrhea is the most common sign of clinical disease
-Diagnoses most commonly by identification of oocyst in feces

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5
Q

What environmental features contribute to coccidiosis in animals?

A

-heavy exposure
-diet changes
-stress
-weaning

Immunity can help prevent

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6
Q

T/F Coccidia oocysts undergo sporogony in the host and become a sporulated oocyst

A

False, sporogony occurs in the environment and forms a sporocyst that contains sporocysts

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7
Q

T/F the infective stage of coccidian parasites is the sporulated oocyst

A

True

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8
Q

What species do Eimeria spp commonly infect

A

-Ruminants
-Pigs
-Birds
-Rodents

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9
Q

What are the three stages of the Eimeria spp life cycle?

A
  1. Environmental (sporogony)
  2. Asexual replication (schizogony)
  3. Sexual replication (gametogony)
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10
Q

What two things affect the pathogenicity of coccida species?

A
  1. The cell type infected (infection at tip of villi causes less damage than infection at base)
  2. The number of generations of multiplication
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11
Q

What two species of cattle eimeria are the most pathogenic?

A

Eimeria bovis and E. zuernii

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12
Q

What are signs of clinical disease in ruminant coccidiosis?

A

-Diarrhea +/- blood
-Fecal stained perianal area
-Straining to defecate +/- rectal prolapse
-Weight loss and/or stunting
-Death

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13
Q

T/F Coccidiosis can be diagnosed by the presence of oocysts in feces

A

False, essentially all young animals will have oocysts in manure, use clinical judgement and look for other signs diarrhea

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14
Q

T/F poultry coccidiosis is one of the most important production diseases of poultry, with most birds being infected with multiple species with different infection sites and signs

A

True

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15
Q

What is the genus that causes enteric coccidiosis in dogs and cats

A

Cystoisospora

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16
Q

What is the prepatent period of canine and feline coccidiosis?

A

10-14 days

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17
Q

What is a spurious parasite?

A

A parasite of another animal species that passes through the gut and is on a fecal sample, but no infection occurs, coprophagia in dogs can lead to this

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18
Q

What can result from cystoisospora suis?

A

Neonatal diarrhea, stunting, and potentially death in pigs

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19
Q

What species causes hepatic coccidiosis of rabbits and what happens as a result?

A

Eimeria stiedae -> parasites are found in the bile duct and can cause severe damage

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20
Q

Define a trophozoite

A

Active feeding stage of protozoa

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21
Q

Define a merozoite

A

Uninucleated, elongated, motile daughter cell of many Apicomplexa

22
Q

Define a schizont

A

Protozoan cell undergoing schizogony by asexual reproduction involving multiple mitoses

23
Q

Define a gamete as it relates to protozoa

A

Haploid sexual cell that unites with another cell in sexual repro. Microgamete -> MALE Macrogamete -> FEMALE

24
Q

Define an oocyst

A

Encysted zygote of Apicomplexa

25
Q

Define a sporocyst

A

A cyst within an oocyst

26
Q

Define a sporozoite

A

last infective stage of sporogony, mostly uninuclear, elongated calls of Apicomplexa, infective for new host

27
Q

Define schizogony process

A

Process of multiple divisions in which a protozoan mother cell divides into daughter cells

28
Q

Define sporogony process

A

Process in life cycle of Apicomplexa in which a zygote divides yielding haploid sporozoites

29
Q

What are the two additional life cycle stages of Toxoplasma gondii

A
  1. Bradyzoite: zoite of Apicomplexa with slow multiplication in CYSTS
  2. Tachyzoite: zoite of Apicomplexa with quick ASEXUAL multiplication in a HOST CELL
30
Q

What is the only definitive host of Toxoplasma gondii and what does this mean

A

Felids, meaning the sexual stages occur only in cats

31
Q

What are the three infective stages of toxoplasma gondii?

A
  1. Tachyzoites (groups)
  2. Bradyzoites (tissue cysts)
  3. Sporozoites (sporulated oocysts)
32
Q

What happens when a warmblooded animal eats a sporulated oocyst?

A
  1. the sporozoites emerge
  2. they penetrate intestine
  3. they undergo rapid multiplication in cell -> tachyzoites spread to all other tissues
  4. Eventually convert to cysts containing bradyzoites
33
Q

T/F The tachyzoite is the pathogenic stage of toxoplasma gondii

A

True

34
Q

What are the methods in which cats get infected with toxoplasma gondii?

A
  1. They ingest bradyzoites in cysts, which is the most common and efficient route
  2. They ingest sporulated oocysts or tachyzoites, which is less efficient and may not lead to patent infection
35
Q

What is the result of all non-felid toxoplasma gondii infections, regardless of the route?

A

tachyzoites multiple and then bradyzoites form cysts

36
Q

T/F Clinical disease from toxoplasma gondii in cats is fairly common

A

false, its rare and caused by tissue tachyzoites

37
Q

What happens when small ruminants are infected with toxoplasma gondii?

A

It is a common cause of abortion that can occur when first infection takes place during pregnancy, but immunity develops and the animal is protected during subsequent pregnancies

38
Q

What are the distinguishing features of Neospora caninum?

A

-canids are the definitive hosts
-dogs must ingest bradyzoites in cysts in intermediate hosts
-intestinal cycle in dogs with no clinical signs, but infection during pregnancy can produce infected litters with rare paralysis

39
Q

What can result from a Neospora caninum infection in cattle?

A

Abortion or persistent infection -> leads to calf being born that will eventually abort

40
Q

What are the distinguishing features of Sarcocystis spp.?

A

-Obligate indirect life cycle
-host specific for intermediate and definitive host
-forms a SARCOCYST in intermediate host

41
Q

What is the infective stage of Sarcocystis spp.?

A

Individual SPOROCYSTS that result from sporulated oocysts passed in feces having their walls broken down

42
Q

What disease results from Sarcocystis neurona?

A

Equine Protozoal Myeloencephalitis (EPM)
Horse is a dead end host

43
Q

What are distinguishing features of Cryptosporidium spp?

A

-It’s not a true coccidia and very tiny
-NO sporogony in the environment meaning it’s immediately infective
-Located immediately under the cell membrane of the microvilli: intracellular and extracytoplasmic

44
Q

What species of Cryptosporidium spp causes neonatal calf diarrhea and can also infect humans?

A

C. parvum

45
Q

What are distinguishing features of coccidian parasites?

A

-Blood borne apicomplexans
-transmitted by hematophagous arthropods
-sexual repro occurs in invertebrate hosts
-piroplasms are most important in vet med (tick borne and babesia)

46
Q

In what ways can Babesia spp be transmitted to other tick stages?

A
  1. One tick stage to another (horizontal)
  2. Female tick to eggs (vertical)
47
Q

What is the disease pathogenesis of Babesia spp.?

A

Release of merozoites results in destruction of RBCs, antigens are absorbed and removed by host.
Results in anemia (hemolytic or autoimmune)

48
Q

How is Babesia spp. diagnosed?

A

Detection in Giemsa stained smears
Serology
PCR

49
Q

What are clinical signs of Babesia spp. in dogs?

A

Anemia, splenomegaly, fever
Transmitted by brown dog tick

50
Q

T/F Bovine babesiosis was eradicated in the US and we got rid of the tick (Rhipicephalus microplus)

A

True