parasitology lab exam 2

what structure carries the hooks in taeniids

proboscis-like structure called rostellum

how many sets of reproductive organs per proglottids in taeniids

1

describe gravid proglottids in taeniids

they have a tree like uterus

how many larval hooks do enclosed oncospheres contain in taenii

6

what distinguishes taeniid eggs from other tapeworm eggs

thick wall and radial striations to give a sunburst appearance.

what are intermediate hosts for taeniid

mammal, usually prey mammals for definitive host

where are adult taeniid’s found

In the predator host’s small intestine

what do taeniid eggs do

they get ingested by the intermediate host. They hatch and penetrate the gut and grow into the intermediate host tissue.

list body parts of adult taeniid

scolex, neck region, and mature proglottids

list taeniid female reproductive systems found in the mature proglottids

ovary, yolk glands, vagina, uterus

list taeniid male reproductive systems found in the mature proglottids

testes and cirrus pouch

T/F cyclophyllidean cestodes eggs usually stay in the uterus until the entire proglottid is shed in the feces

True

which worm genus is smaller, echinococcus or teaniid

echinococcus is smaller

protoscolex is a stage/structure of what

a portion of a unilocular hydatid cyst located inside the broad capsule. found in echinococcus and taenia spp.

what occurs within each chamber the of germinal membrane of E. multilocular cysts?

larval scolices (protoscolices)

how does multilocular hydatid cyst affect host tissue?

Grows very invasively

do cysticercoid larvae develop in intermediate or definitive host and what kind of organism is it?

in intermediate and arthropods

what kind of larvae have inverted scolexes

taenia

what type has fluid filled cysts?

taenia species

is cysticercoid cyst fluid filled or solid tissue

solid tissue cyst

most common tapeworm of cats and dogs

Dipylidium

What is the intermediate host of D. caninum?

flea or uncommonly lice

How do dogs and cats become infected with D. caninum?

by ingesting fleas that contain the larva

list some differences between proglottids of taenia and dipylidium

the taenia has larger more pronounced sexual organs and Dipylidium has 2 vaginas or the exits or whateva

which genus doesn’t have much of any hooks or suckers on the scolex

Diphyllobothrium

what is unique about the Diphyllobothrium proglottid?

genital pore median instead of lateral

what genus of tapeworms does not have hooks on the eggs and may have an operculum

Pseudophyllidean tapeworm eggs

describe Pseudophyllidean maturation

Egg → Coracidium → Procercoid → Plerocercoid → adult

what are general characteristics of Trematoda and what are they aka

Flukes. Adults possess suckers for attachment and all species are parasitic

what is the important subclass of trematodes

Digenea- seen in people and land animals

describe trematoda life cycle/characteristics

endoparasites(internal), asexual reproduction in snail host with sexual reproduction in the vertebrate host.

T/F - Digenea have a low specificity for their snail host

False, they do have high specificity for the snail host.

What organism has a digestive system composed of pharynx leading into a branched cecum or ceca(plural)

Digenea trematodes

describe trematode eggs

operculated (have cap), brown or yellow

what are the 6 stages of trematode life cycle

egg, miracidium, asexual reproduction in the snail, cercaria, metacecaria, adult.

Where do trematode eggs need to be and how can they be found in a sample.

They need to be somewhere near a snail for survival and they can be tested for using sedimentation technique in fecal samples.

what is unique about the miracidium stage

This stage emerges from the egg, they have cilia, and they swim and penetrate the snail intermediate host.

Describe the first step of asexual reproduction in the snail host.

miracidium loses its cilia and becomes a reproductive body called a sporocyst

sporocyst?

produces larval stages within itself, a stage of trematodes particularly stichosomes

what do the sporocyst larval stages turn into? And what do they do?

Redia, escape the sporocyst and invade the snail gonads/digestive gland.

What is formed by the redia

Cercariae

stage of trematode that has a short free living existence before penetrating the second intermediate host. Some species encyst on vegetation and other have tails for swimming.

Cercaria

what is a metacercaria?

A stage of trematodes that is encysted. It can be encysted in a secondary intermediate host which is highly variable or just on vegetation. It is ingested by the definitive host.

is fasciola a large or small trematode

very large

what is ceca?

intestine, simple forked blind pouches

what is the oral and potential ventral suckers for

digestive system, intake food, and attachment organs

Muscular pharynx and tubular esophagus belong to what system in what genus

digestive system in trematoda

are trematodes hermaphrodites

yes, except stichosomes

list the female organs of a trematode

ovary, vitelline aka yolk glands, uterus, and genital pore

list the male organs of trematodes

paired testis and cirrus and cirrus pouch (acts as a penis)

what genus does this depict

trematode

what does digenetic mean

requires two or most hosts to complete the life cycle

what family of trematodes is very important for human medicine.

Schistosomes

what is unique about schistosomes?

The have separate sexes

what are the 3 main species of Schistosomes that impact humans

S. mansoni, s.haematobium, and s. japonicum

where do S. mansoni and S. japonicum live in humans?

These two species live in mesenteric veins

where does S. haematobium live?

veins in the bladder

in what species does the male wrap his body around the female in a state of permanent copulation? and what is the name of the grove that the female fits into?

S. mansoni and gynecophoric canal

what is the primary source of pathology for schistosomes

eggs as they pass through tissue to reach the gut/bladder.

what can happen if mesenteric schistosome eggs are moved into the liver?

they can cause inflammation and granuloma formation

how are trematode eggs tested for?

fecal examination but sedimentation test instead of fecal flotation

How many suckers does Fasciola have?

2

What is the function of the vitelline glands?

provide essential nutrients for egg formation including the hard shell and embryo nutrients

How big is a Fasciola egg?

~140 microns long by ~75 microns wide

How do you tell the difference between a male and female schistosome?

Males are short and stouter with a distinct ventral groove. Females are darker and smoother, longer and slender.

What is the gynecophoric canal?

where the female worm resides in schistosome reproduction

What structures present in the adult are also present in the cercaria?

basically everything except the tail and penetration glands

What stages of the fluke life cycle are found in the snail?

miracidium, sporocysts, rediae, and cercariae

How does H&E staining work

hematoxylin stains nucleic acids dark blue or black and eosin stains the cytoplasm pink-magenta

Trichrome stain

used to identify protozoan parasites in fecal smears. the cytoplasm stains blue/green and the nuclei stain red/magenta

Iron-hematoxylin stain

used for nuclei morphology, used on fecal smears and tissue sections. Cytoplasm stains yellow gold and the hematoxylin stains the nucleus dark blue/ black

Giemsa stain

usually used on blood smears but also the other two. cytoplasm stains bluish and nuclei stain red/magenta

pseudopodia

the way amoebas move, clear areas.

what is the difference between vesicular and compact nuclei

how tight the chromatin are, vesicular is more lose and considered to contain a lot of fluid.

what stage is this

trophozoite stage

what stage is this

cyst stage (fecal)

what phylum is toxoplasma

apicomplexa

what are the unique organelles in apicomplexa

rhoptries, micronemes, and dense granules. also the apicoplast

rhoptries function

responsible for forming the parasitophorous vacuole that houses the parasite inside the cell.

Micronemes function

Release adhesin proteins that begin initial attachment to the host cell and allow the gliding motility so the parasite can explore the surface of the host cell.

what do the dense granules do

modify the vacuole housing the parasite to increase survival and replication chance of success.

dense granules are found where

cytoplasm

how often does taxoplasma divide once it invades a host cell

every 6-8 hours

What is the divalent cation that plays a critical messenger role during Toxoplasma egress?

calcium ion Ca2+

Is Toxoplasma enclosed in a vacuole inside the host cell or is free in cytoplasm?

inside a special vacuole

Why is the intracellular life cycle of Toxoplasma is called as the lytic cycle?

the rapid replication of the tachyzoite stage causes the cell to burst or lyse

what parasite causes malaria

Plasmodium

what are merozoites

invasive asexual stage of plasmodium produced in the liver that rapidly infect RBCs

most important blood protozoan pathogen in domestic animals and one of the most important in humans.

Babesia

How is Babesia transmitted

tick (ixodes scapularis) transmitted parasite, specifically the sporozoite stage.

where are babesia merozoites formed?

vertabrate red blood cells, usually seen at 2 in a cell sometimes 4

what is the most useful diagnostic procedure for babesia

geimsa staining blood smears

what species of Babesia affect cattle?

B. bovis and B. bigemina

what species of babesia affect dogs

B. canis and B. gibsoni

what species of babesia targets humans

B. microti

what is the causative agent of Chagas Disease

what disease does Trypanosoma cruzi cause

how is Trypanosoma cruzi transfered

through the feces of triatomine bugs

is T. cruzi intra or extra cellular

extracellular

what can chronic infections of T. cruzi lead to?

heart failure

what are the 4 stages of Trypanosoma

Trypomastigote, Epimastigote, Promastigote, Amastigote