Parasitology exam review 2 quizzes/study guides/review questions?

Review q/summary slide

Parasitic protozoa are found in three primary phyla –
Sarcomastigophora, Apicomplexa, and Ciliophora
 Protozoal parasites are transmitted to host in the cyst stage
 Giardia is a common flagellate that can infect many mammals and
humans
 Trypanosomes and Leishmania spp. are zoonotic parasites found in the
southern U.S.
 Tritrichomonas foetus – causes infertility, abortion, and pyometra in cattle
 Cats are the only definitive host of Toxoplasma gondii that can affect
humans
 Cytauxzoon felis is an intracellular parasite of RBCs that is usually fatal to
cats
 Rickettsia are obligate intracellular parasites

What are proglottids? What is a scolex? Where and what is the hexacanth?

Proglottids: The different segments of the tape worm. One of the “boxcars” of a railroad train per say.

Scolex: The head

Hexacanth: Hexacanth is the larval stage of the cestode. They are found in the eggs in the gravid proglottids and have 6 hooks.

What are the 5 metacestode forms?

Cysticercoid, Cysticercus, Coenurus, Hydatid cyst, or Tetrathyridium. These larval stages differ in their choice of host, their structure, their predilection site, and their pathogenicity to the intermediate host.

What are examples of pseudotapeworms?

Diphyllobothrium latum, the “broad fish tapeworm,” and Spirometra mansonoides, the “zipper tapeworm.”

What is unique to Hymenolepis nana ?

It is the only tapeworm that does not need an intermediate host for any developmental stage in its life cycle.

What are the cestodes of ruminants, that are adult forms?

Moniezia benedini, Moniezia expansa, Thysanosoma actinoides,

What are two Taenia intermediate forms found in cattle and pigs?

Cysticercus fasciolaris and Cysticercus pisiformis

Horse Cestodes?

Anoplocephala perfoliata, Anoplocephala magna, and Paranoplocephala mamillana.

True tapeworms of dogs & cats – and their intermediate hosts?

Dipylidium caninum - intermediate host: Adult fleas

Taenia pisiformis - IH: Rabbits and hares

Taenia hydatigena - IH: ruminants

Taenia ovis - IH: sheep

Taenia taeniaeformis - IH: Rats and mice

Multiceps multiceps and Multiceps serialis - IH: Sheep and rabbits

Echinococcus granulosus - IH: Sheep, cattle, humans, and other herbivores

Echinococcus multiloculari - IH: Rats, mice, humans, and voles.

What are the parasites in the genus Multiceps?

Multiceps (Taenia) multiceps and Multiceps serialis

What is the significance of Echinococcus tapeworms?

They have extreme zoonotic potential

What is different about the Mesocestoides tapeworms?

Unusual true tapeworms in that they use two intermediate hosts instead of one intermediate host.

What are the 2 Pseudotapeworms of dogs and cats?

Spirometra, and Diphyllabothrum?

Life cycle of diplydium caninum? 

Describe trematodes?

Also called Flukes. Unsegmented, flattened, leaf like bodies, with one anterior sucker at the mouth and one ventral sucker near the middle of the body.

Which variety of trematodes do veterinarians focus on?

Subclass Digenea. Usually associated with wild and domestic animals and humans.

Describe the life cycle of trematodes using miracidium, sporocyst, redia, cercaria and meta-Cercaria

● Fluke’s produce eggs that exit from the uterus through the genital pore, which is usually passed out through the host's feces.

● If the egg makes contact with water, it will hatch and produce a motile stage called a miracidium. The miracidium swims using cilia to find an aquatic snail, which it penetrates through the skin and develops into a sporocyst.

● The sporocyst is just a sac where the next stage develops.

● The redia is the next stage and within the redia the cercaria develops.

● The Cercaria often has a tail and emerges from the snail and swims in the water.

From this point on, depending on the species the cercaria will go one of three ways.

1. It might directly penetrate the skin of the definitive host.

2. It might attach to vegetation, lose its tail, surround itself with a thick cyst wall, and then develop into metacercaria. Then the metacercaria will be eaten along with the vegetation by the definitive host.

3. Or it might lose its tail, penetrate a second intermediate host, surround itself with a thick cyst wall, and then develop into a metacercaria. This metacercaria would then be ingested with the second intermediate host by the definitive host.

What are the GI tract flukes of ruminants?

Dicrocoelium dendriticum, Paramphistomum species, Cotylophoron species, and Fasciola

hepatica, and Fasciola magna

List the GI flukes of the dog and cat.

Platynosomum fastosum, Nanophyetus salmincola, Alaria species

The lung fluke of dogs and cats.

Paragonimus kellicotti

What is the Schistosome of the dog?

Heterobilharzia americana. (Schistosome: blood flukes: unique flukes because they are not hermaphroditic [does not have both male and female reproductive organs])

What is the Schistosome of the bird (wild).

What is the Schistosome of the bird (wild).

What describes the Acanthocephalans? What are the two species that are parasitic in domestic animals?

They are called the thorny-headed worms/spiny-headed worms. They are elongate, cylindric worms, tapered on both ends, and possess a retractable proboscis, or “nose,” on the anterior end. This proboscis is covered with tiny backward-facing spines and serves as an organ of attachment.

Macracanthorhynchus hirudinaceus: the thorny-headed worm of swine. Oncicola canis: the canine acanthocephalan

What is the common intermediate host of the Acanthocephalans?

Dung Beetle.

What is the feline taeniid parasite? 

T. taeniaeformis

This tapeworm uses rabbits (/rodents) as the intermediate host?

Taenia pisformis

Where are the Proglottids of Dipylidium caninum often found?

In pets bed and/or hanging off hairs around the rectum

Which genus of tapeworm is most likely to be harmful to humans if it is ingested?

Echinococcus

Which is the tapeworm of horses that could be treated with pyrantel pamoate?

Anoplocephala spp.

This small tapeworm is usually found in rodents but can also infect dogs and humans also. This parasite can be transmitted without an intermediate host.

Hymenolepis nana

The hold fast (attachment) organ of the adult tapeworm is called ___________.

Scolex

What is the intermediate host for Multiceps multiceps?

Sheep

The intermediate host of Fasciola hepatica is? 

Snails 

These stem cells come from the bone marrow and help make up the lymphoid system. Which cell does this describe?

B-cells

Metacercaria of Fasciola hepatica are found?

Encysted on vegetation around swamps and ponds

Which of the following flukes is considered to be the largest of the known species?

Fasciolodes magn

The most abundant of all immunoglobulins in the body are?

IgG

Paragonimus kellicotti is known as?

The lung fluke of the dog and cat

Fasciola hepatica can cause what in cattle?

can cause hepatitis in cattle with infection

Nanophyetus salmincola what does it cause/common name? 

“salmon poisoning” fluke of dogs

What is Digena?

most important class of digenetic flukes in veterinary medicine

Platynosomun fastosum what does it cause/common name?

known as a “lizard poisoning” fluke of cats

What is Cercaria?

Stage that is released from the snail that will either penetrate the second host or encyst on grass. 

Anaplasma marginale is a blood parasite causing anemia in which of the following species?

Bovine

Which protozoan parasite causes a venereal disease in cattle?

Tritrichomonas

Flagellate blood parasite of dogs & primates (can affect other species), it is small. It is more common in Central & South America than in the U.S., transmitted by blood sucking insects. ??

Trypanosoma

Which of the following parasites die and deteriorate very soon after passage?

Giardia trophozoites

Trophozoites and cyst forms are associated with? 

Protozoans

Which of the following is the most commonly diagnosed protozoan parasite in puppies and kittens?

Giardia

Which patient is least likely to be shedding Toxoplasma gondii organisms?

1. A 10-year-old cat that has not been outside in over 8 years: the owner has no other pets

2. A 1-year-old barn cat who hunts mice to supplement her diet of dry cat food

3. A sick, 5-year-old cat recently adopted from the local animal shelter, whose history is unknown.

4. A 4-month-old kitten that wandered up to the owner’s front door as a stray at the age of 3 months

1. A 10-year-old cat that has not been outside in over 8 years: the owner has no other pets

Which parasite causes malaria?

Plasmodium

Small coccidia with cats being the definitive host?

Toxoplasma

What are the characteristics of a Protozoan?

Unicellular (one-celled) organism

What are the four (4) phyla of Protozoans

1) Flagellated 2) Amoeboid 3) Apicomplexan 4) Ciliated

What is the trophozoite stage? What do flagellates have at least one of?

Trophozoite – is the “moving” stage (active) - Flagellates have a flagellum (at least one)

What is a cyst stage called? How do ciliates move?

Resistant cyst stage – Bradyzoite (never found that in the text book). Ciliates move by virtue of
cilia – hair like projections.

What group of parasites are the apicomplexans?

Coccidia – Emeria, Cystoisopora, Toxoplasma, Sarcocystis, Cryptosporidium. Also – Plasmodium,
Haemoproteus, Leukocytozoon, Babesia, Theileria, Cytauxzoon

What species play host to Giardia?

Pretty much all species do

Entamoeba histolytica causes what symptoms in people and most other host?

Dysentery - diarrhea

What is the former name of Cystoisospora?

Isospora

Which of the Cystoisospora spp. is the smallest?

C. burrowsi

The prepatent period for Cystoisospora is generally how long?

Usually 7 – 14 days

Who is the definitive host for Toxoplasma gondii ? Is it zoonotic ?

Cats – it is zoonotic because other species including humans can be dead-end intermediate host

What group of Protozoans do Cryptosporidium spp. belong to? Is this group zoonotic?

They belong to apicomplexans and they are zoonotic

What about Sarcocystis spp. ? What group of parasites do they belong in? Are they zoonotic?

Also apicomplexan group, but does not appear to be zoonotic

List the blood protozoans of dogs and cats?

Trypanosoma cruzi, Leishmania spp., Babesia canis, Cytauxzoon felis, Hepatozoon canis, H.
americanum

What is the amastigote stage vs. the trypomastigote stage?

Trypomastigote – does not live W/in a cell but is found free swimming. Amastigote – does not
have a flagellum – is found in reticulo-endothelial cells.

Are ciliates pathogenic in ruminants GI?

No, they are actually mutualistic – so both hosts benefit

What are the apicomplexans that affect ruminant’s GI system?

Eimeria bovis, E. zuernii, Cryptosporidium spp.

What are the 2 protozoans of the circulatory system of cattle?

Trypanosoma spp., Babesia bigemina

The protozoan of the urogenital system of ruminants is what? It causes what clinical signs?

Tritrichomonas foetus - cause reproductive “failure” and abortions

Protozoans of the GI of horses are?

Giardia, Eimeria leuckarti

Protozoans of the Blood/Circulatory system of horses?

Theileria (Babesia) equi

Is there a apicomplexan that affects the nervous system of the horse? How is it related to EPM or
other protozoal diseases?

Sarcocystis neurona – causes EPM, but…. It also mimics many other neurological diseases

What about swine do they have an apicomplexan, ciliate parasite?

Yes, Balantidium coli – a ciliate. Cystoisopora suis – an apicomplexan

What about birds/poultry? Do they have the same?

They have flagellates & apicomplexans – coccidia is rare in birds

Lab animals/ rodents Apicomplexan of Rabbits, which is most pathogenic?

Eimeria stiedae – highly pathogenic – many other Eimeria spp. affect the GI trac