General + Phylum Apicomplexa (Coccidia) (Cram)

Common name for parasites of the Kingdom Protista

Protozoans

Are protozoans multicellular or unicellular?

Unicellular

Kingdom Protista parasites do not have ova, what are the eggs called?

Oocysts

How are the different Phyla of Kingdom Protista divided?

Based on movement

What are the three Phyla of Kingdom Protista of veterinary medicine significance?

1. Phylum Apicomplexa

2. Phylum Sarcomastigophora

3. Phylum Ciliophora

What kind of motility do Phylum Apicomplexa parasites have?

Non–motile

True or false: All members of Phylum Apicomplexa are parasitic

True

Are parasites of Phylum Apicomplexa intracellular, extracellular, or intercellular?

Intracellular, they cause disease by destroying cells from within

What are the two most important groups within Phylum Apicomplexa?

1. Coccidia

2. Hemosporidians

Coccidia develop in the epithelial cells of the gut and cause _______ (coccidiosis)

enteritis

How are coccidia typically transmitted?

Fecal contamination

What are the six important coccidia genera? Remember: Every Cat Secretely Craves Nonstop Touch

1. Eimeria

2. Cystoisospora

3. Sarcocystis

4. Cryptosporidium

5. Neospora

6. Toxoplasma

Are coccidia typically host specific or not?

Typically host specific

What are the two Eimeria species specific to cattle?

1. Eimeria zuernii

2. Eimeria bovis

What is the Eimeria species specific to rabbits?

Eimeria stiedae

What are the three Cystoisospora species specific to dogs, cats, and pigs respectively?

Dogs – Cystoisospora canis

Cats – Cystoisospora felis

Pigs – Cystoisospora suis

True or false: A host cannot be parasitized by multiple species of coccidia simultaneously, the species will compete with each other

False. A host can be parasitized by multiple spieces of coccidia (ie. Eimeria bovis and Eimeria zuernii in cattle)

Clinical symptoms are important for the diagnosis of coccidia, what else is a diagnosis based on?

Identification of oocysts in the host's feces

Is replication of coccidia species sexual, asexual or both?

Both

Which genera sometimes uses paratenic hosts, Cystoisospora or Eimeria?

Cystoisospora

What are the structures outlined in orange and blue called?

Orange – Sporozoite

Blue – Sporocyst

What is the infective stage of coccidia?

Sporozoites

Sporozoites are liberated from the oocyst and the sporocyst in the host and invade the host's intestinal cells to asexually reproduce. What is the term for the asexual reproduction of sporozoites?

Shizogony

As sporozoites mature they can look for other cells to invade or may undergo sexual reproduction. What is the term for the sexual reproduction of sporozoites?

Gametogony

What is the prepatent period of coccidiosis in dogs and cats?

7–14 days

Drug that slows or weakens coccidia, but does not kill them

Coccidiostatic

Drug that kill coccidia

Coccidiocidal

What is the genus species of coccidia that affects cats, and poses a zoonotic risk especially to pregnant women?

Toxoplasma gondii

What are the intermediate hosts of Toxoplasma gondii?

Almost every mammal and bird

What is the site of Toxoplasma gondii in the definitive host?

Small intestine

What is the site of Toxoplasma gondii in the intermediate host?

Muscles (also liver, lung, eye, and brain)

Term for the rapidly multiplying stages of Toxoplasma gondii in sporulated oocysts

Tachyzoites

Term for the slowly multiplying stages of Toxoplamsa gondii that form tissue cysts within the muscle of the IH

Bradyzoites

Can cats also have bradyzoites?

Yes

What are the two ways a cat can become infected with Toxoplasma gondii?

1. Paratenic host (usually rodent)

2. Oral ingestion (infective oocyst)

The prepatent period of Toxoplasma gondii depends on the life stage ingested. Between bradyzoites and oocysts/tachyzoites. Which PPP is longer?

Oocysts and tachyzoites are longer (up to 3 weeks)

What are the two types of Toxoplasma gondii infections in humans?

1. Acquired

2. Congenital

What are the three stages of Toxoplasma gondii ingested by a human that can cause acquired toxoplasmosis?

1. Bradyzoites

2. Tachyzoites

3. Sporozoites

What stage of Toxoplasma gondii needs to be ingested by a pregnant woman to cause congenital toxoplasmosis in the fetus?

Sporozoites

What are some symptoms of congenital toxoplasmosis in humans?

Abortion (early pregnancy), stillbirth, blindness, retardation, learning difficulties

What can be done to protect pregnant women from Toxoplasma gondii?

Pregnant women do not clean litter boxes, litter boxes are deep cleaned frequently, wear gloves while gardening, wash hands after handling cats

Fecal testing is ineffective when testing for Toxoplasma gondii, cats only release oocysts once in their life for 1–2 weeks. What test is done instead?

Serological testing

What are the two Cryptosporidium species that affect mice and calves and just calves respectively?

Mice and calves – Cryptosporidium muris

Calves – Cryptosporidium parvum

What age of calf do C. muris and C. parvum affect respectively?

C. muris – Older than 3 months

C. parvum – 1–3 weeks old

What type of calf do Cryptosporidium species affect more: beef or dairy calves?

Dairy calves

What is the site of Cryptosporidium in the definitive host?

Small intestine

At what stage are Cryptosporidium infective?

Oocysts, don't need to be sporulated

Are Cryptosporidium species zoonotic?

Yes

What is the genus species of coccidia that affects the nervous system of horses?

Sarcocystis neurona

What is the definitive host of Sarcocystis neurona?

Opossum

What are some of the intended intermediate hosts for Sarcocystis neurona, the parasite will form sarcocysts in the host's skeletal muscles

Cats, ferrets, raccoons, sea otters, skunks, and seals

What kind of host is a horse when infected with Sarcocystis neurona?

Dead end host

What is the name of the neurological disease caused by Sarcocystis neurona in horses?

Equine protozoal myeloencephalitis (EPM)

What are some clinical signs of EPM in horses?

Ataxia, head tilt, recumbency, muscle atrophy of hindlimbs, and dysphagia

How many sporocysts and sporozoites are present in a sporulated Sarcocystis neurona oocyst?

Sporocysts = 2

Sporozoites (per sporocyst) = 4

What is the genus species of coccidia that causes abortion in cattle?

Neospora caninum

What is the definitive host of Neospora caninum?

Dogs and wild dogs

What are some intermediate hosts of Neospora caninum?

Cattle, sheep, goats, bison, moose, and white–tailed deer

What life stage of Neospora caninum can intermediate hosts and sometimes definitive hosts harbour in their tissues?

Bradyzoites

Is Neospora caninum zoonotic?

No

What can be done to prevent dogs from becoming infected with Neospora caninum?

Fence off cattle and don't allow dogs to ingest cow's placental tissue