Apicomplexa Flashcards

(85 cards)

1
Q

What are the Apicomplexas we are concerned about?

A
Eimeria 
Cystoisospora
Cryptosporidium 
Toxoplasm
Neospora
Sarcocystis
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2
Q

Most of the effective drugs to the Apicomplexa work against what?

A

Apicoplast

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3
Q

What are the three basic life cycles of Apicomplexa?

A

Sporogony (Becomes infectious)
Gametogony (Sexual reproduction)
Merogony (Asexual phase happens in vector)

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4
Q

Which Apicomplexa has the simplest life cycle?

A

Eimeria

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5
Q

Eimeria are ________ parasites that are usually in the _________ cells

A

obligate intracellular

gut epithelial

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6
Q

How is Eimeria transmitted? What is the infective stage? Where does it develop? What is passed in the feces?

A

Fecal-oral
Sporulated oocyst
Sporulates in the environment
Non-infective, non-sporulated oocyst

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7
Q

Describe the life cycle of Eimeria starting with a non-sporulated oocyst

A

It contains a single sporont
Undergo sporogony to become infective.
Sporont undergoes two divisions to form 4 sporoblasts
Sporoblast develops into a sporocyst with 2 sporozoites

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8
Q

How many sporozoites does a sporulated oocyst have?

A

8

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9
Q

Where does sporogony occur for Eimeria?

A

In the environment

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10
Q

What temperature causes oocysts to sporulate faster?

A

Warmer temperature

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11
Q

What is the asexual proliferation phase called?

A

Merogany

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12
Q

In merogany, what do the sporozoites become?

A

Merozoites

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13
Q

Final asexual generation of merozoites proceed to what?

A

Gametogony

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14
Q

_____ is the sexual reproduction phase. What do the females become? Males?

A

Gametogony
Microgametes
Macrogametes

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15
Q

T/F There is no zoonosis in Eimeria species

A

TRUE; there is no crossover

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16
Q

T/F Immunity to Eimeria is species specific; there is absolutely no cross over

A

TRUE; once again. No crossover

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17
Q

What does clinical disease associated with Eimeria come from?

A

The amount of oocysts that are ingested
species
Host factors

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18
Q

What is the lag time for oocyst detection and clinical signs from Eimeria?

A

Clinical signs can usually be seen 1-2 days before the oocysts can be detected in feces

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19
Q

What are the three types of coccidiosis?

A

Winter, enteric, and nervous

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20
Q

_______ coccidiosis has clinical signs that are seen in Janurary to MArch

A

Winter

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21
Q

Where do cocidiosis lesions occur?

A

Distal ileum lesions are associated with the asexual phase

Cecum/colon is associated with the sexual stage

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22
Q

What steps could you take to control/prevent bovine coccidiosis?

A

Remove and treat clinical cases
Minimize crowding/improve sanitation
Keep feces out of water/feed
Kill oocytes with sunlight and dessication

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23
Q

What is the most pathogenic Eimeria in small ruminants

A

Eimeria ovinoidalis

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24
Q

What is the Eimeria that infects the ceca of chickens? The small intestine?

A

Eimeria tenella

Eimeria necatrix

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25
What causes hepatic coccidosis in rabbits?
Eimeria stiedae
26
What is the one difference between Eimeria and Isospora?
Isospora often utilizes a paratenic host
27
Dogs infected with cystoisospora sheds what in feces? What is infective? Where does sporogony take place?
Unsporulated oocyst Sporulated oocyst Environment
28
What are some clinical signs associated with cystoisospora infection? Where are these most common?
anorexia, weight loss, possible vomiting. Can see oocysts in feces Seen in kennels or catteries
29
What is unique about cystoisospora oocysts?
They have no micropyle cap They have only 2 sporocysts 4 sporozoites per sporocyst
30
What is the best way to control cystoisospora?
Saitation and post-partum treatment of queen or bitch
31
__________ is the cystoisospora that is ubiquitous with swine and causes neonatal diarrhea
Cystoisospora suis
32
T/F Snail is a common paratenic host for Cystoisospora suis
FALSE; there generally is no PH for this
33
Where would you look to complete a post-mortem diagnosis for Cystoisospora suis?
Jejunum and duodenum for fibronecrotic membranes
34
What are the treatments of choice for Cystoisospora suis?
Toltrazuril and Diclazuril
35
_____ causes cryptosporidosis
Cryptosporidium
36
Intestinal cryptosporidia in humans and cattle is most commonly caused by what?
Cryptosporidium parvum
37
What is unique about Cryptosporidium parvum?
Sporogony occurs within the host
38
What type of Cryptosporidium parvum infects cattle? Humans?
Type 1 | Type 2
39
The sporulated oocyst of Cryptosporidium parvum has how many sporozoites?
4
40
What are the two types of oocysts that Cryptosporidium parvum produces?
Thick shelled | Thin shelled
41
What are the differences between the thick shelled and thin shelled oocysts of Cryptosporidium?
Thick shelled are passed in feces | Thin shelled is auto-infective
42
T/F Cryptosporidium is zoonotic
TRUE; it can give ya the screamers
43
T/F Cryptosporidium must be treated, even in the immune competent host
FALSE; this is usually self limiting as the system catches up
44
What would you use to diagnose cryptosporidium ante-mortem?
Sugar fecal float | Oocysts will be pale pink and refractile in this solution
45
What is the treatment for Cryptosporidium?
Eh, idk nothing really works. | Provide supportive care
46
What is difficult about preventing and controlling Cryptosporidium in a herd?
It is autoinfective so just limiting the oocyst exposure may not work. Water purification also does not eliminate Cryptosporidium
47
How can you kill cryptosporidium oocyst/
Repeated thawing and freezing
48
What is the cause of Toxoplasmosis?
Toxoplasma gondii
49
T/F Toxoplasma gondii can infect all warm blooded animals and is highly zoonotic
TRUE
50
What is different about the Tozoplasma gondii life cycle?
They have tachyzoites and bradyzoites
51
What are tachyzoites? Bradyzoites?
Tachyzoites: quick proliferating intracellular stage Bradyzoites: slow proliferating stage within a tissue cyst
52
What is the source of infection for Toxoplasma gondii?
Sporulated oocyst ingestion Ingest tissue cyst with bradyzoites from IH Transplacentally via tachyzoites
53
What is the definitive host for Toxoplasma gondii? What is the life cycle like?
Cats Merogony and gametogony occur in the GI tract. Shed unsporulated oocysts. Extra-intestinal reproduction also occurs: tachyzoites in any cell, bradyzoites in tissue cysts.
54
What is the life cycle of Toxoplasma gondii in the intermediate host? What is an intermediate host?
Infection via ingestion of sporulated oocysts ONLY intracellular takes place Tachyzoites and bradyzoites can be found in the brain, eyes, and muscle Mammals and basically any animal.
55
T/F Intermediate hosts infected with Toxoplasma gondii shed oocysts
FALSE
56
T/F Cysts in the IH persist for the life of the animal
TRUE
57
Can tachyzoites be cleared by an immune-competent host?
Yes. When the cyst walls break down and release the bradyzoites, which then find a new cell, they revert back to tachyzoites which can be cleared
58
What are the clinical signs of animals infected with Toxoplasma gondii?
Generally asymptomatic | Tachyzoites can cause inflammation in multiple organ systems
59
T/F Cats only shed oocysts of Toxoplasma gondii once in their life
TRUE; they only shed oocysts after their first primary exposure
60
What symptoms would you see in humans infected with Toxoplasma gondii?
Flu-like symptoms in immune competent adults | Encephalitis in immune compromised adults
61
What would you do to diagnose Toxoplasma gondii?
Fecal floats to detect the oocysts
62
How do you prevent infection with Toxoplasma gondii?
Prevent the ingestion of tissue cysts (wear gloves when handling raw meat) Wash hands after handling raw meat Don't drink unpasteurized goat milk Prevent oocyte sporulation and ingestion
63
How do you prevent cats from becoming infected with Toxoplasma gondii?
Prevent hunting, don't feed raw meat, and clean out the litter box daily.
64
________ is only known to have dogs and coyotes as its definitive host
Neospora caninum
65
Neospora caninum uses what for intermediate hosts?
Cattle and deer
66
How can infection of Neospora caninum occur?
Ingestion of sporulated oocysts Ingestion of tissue cysts with bradyzoites Transplacental transfer of tachyzoites (MOST COMMON)
67
What is the life cycle of Neospora caninum in the dog?
intestinal merogony and gametogony Non-sporulated oocysts shed in the feces Extra-intestinal occurs in all hosts Sporozoites or bradyzoites become tachyzoites, which can infect any cell type and can usually cause the problems
68
What is different about the Neospora caninum cysts?
They have much thicker walls than the Toxoplasma gondii ones.
69
Bovine _____ is a major cause of cattle abortions worldwide
neosporosis
70
Inflammation of the placenta and fetus in cattle is associated with what form of Neospora caninum?
Tachyzoites
71
How do you prevent your cattle from becoming infected with Neospora caninum?
Usually endemic resulting from transplacental infection | Can see outbreaks with feed and dog feces
72
Canine neosporosis is usually a problem in _____ and is a result of ______ infection
Pups | congenital
73
What are some of the signs of canine neosporosis?
Leg weakness and ataxia | Can progress to paralysis of the hind limbs
74
What causes protozoal myeloencephalitis?
Sarcocystosis
75
What is the life cycle of Sarcocystis?
Obligate indirect cycle involving 2 hosts Carnivore is definitive host Herbivore is intermediate host
76
Describe the life cycle of Sarcocystis in the intermediate host
Merogony: muscular phase that is initiated by merozoites from last stage of merogony gives rise to cysts with bradyzoites in mature muscles that persist for the life of the host
77
Describe the life cycle of sarcocystis in the definitive host
Infection occurs via ingestion of bradyzoites, from the tissue cysts in IH. Bradyzoites infect enterocytes; undergo gametogony and produce oocysts. Oocysts sporulate in the gut, produces sporocysts or sporulated oocysts in the feces
78
T/F Sarcocystis is immediately infective once it is passes in the feces of carnivores
TRUE; sheds sporozoites or sporulated oocysts
79
What Sarcocystis species causes Equine protozoal myelitis
Sarcocystis neurona
80
What is the definitive host for Sarcocystis neurona?
Opossum
81
T/F Sarcocystis neurona is not really a big problem in the US
FALSE; if you see a horse with CNS type disease this should raise on your list of differentials
82
T/F Horses are an abberrant intermediate host for Sarcocystis neurona
TRUE; they are a dead end intermediate host
83
What are some signs associated with equine protozoal myeloencephalitis ?
Focal, soft, discolored areas of the spinal cord that are generally asymmetric Usually are just general CNS clinical signs
84
What are some risk factors for equine protozoal myeloencephalitis?
Opossums in your barn | Barns near your farm
85
How do you diagnose equine protozoal myeloencephalitis?
This is more or less a rule out lesion