Entire Parasites

What class are flatworms

plathyelminthes

What class are nematoda

nematoda

Do platyhelminths have a body cavity?

no they are acoelomate

Describe the digestive tract of platyhelminths

incomplete or absent

What are the two classes of platyhelminths

trematoda (flukes)

cestoda (tapeworms)

How do platyhelminths attach?

suckers and hooks

Are platyhelminths hermaphoroditic or dioecious

hermaphroditic

What are flukes?

trematoda

What are tapeworms?

cestoda

Where are the suckers on flukes?

both oral and ventral surfaces

Describe the life cycle of fluke parasites?

at least one intermediate host

What is the class of flukes

tremadota

What is the class of tapeworms

cestoda

What is an important food born zoonotic trematode

liver flukes

Where are liver flukes found?

bile ducts

What are the two intermediate hosts of the liver fluke?

snails and fish

Where are liver flukes often found?

In geographical areas which eat raw fish

Describe the dioecious nature of blood flukes

Male and female always coupled

Male is smaller

What is the intermediate host of blood flukes?

snail

How do blood flukes infect the definitive host (humans)

skin penetration by larvae

Why do platyhelminths exist in the small intestine?

They lack a digestive system, so use the digestive system of the host

Describe the sexual dimorphisim of cestoda

not present, they are hermaphroditical

Where do the larvae of cestoda reside?

essentially anywhere

Describe the life cycle of cestoda (tapeworms)

indirect

What are the two hosts for the pork tapeworm

pork = ih

human = ih and/or dh

What is a gravid progottolid

A sexually mature progotolid full of fertilised eggs

How do humans become infected with pork tapeworm?

ingest cysts in unsufficently cooked pork

What stage of nematodes is generally the infectious one?

The third larval stage

What does it mean for eggs to be mamillated

covered with small, rounded bumps

What is the benefit of roundworm eggs being mamillated

protection

Where do hookworms attach?

The musoca (innter lining of membranes)

What structure do hookworms use to attach to the mucosa?

The buccal capsule

What is the buccal capsule?

The mouth structure of hookworms

Why are hookworms called hookworms

they are bent dorsally, appear like hooks

What class are hookworms?

nematode

What class or arthropods are Lice?

Insecta

What class of arthropods are

Arachnida

What causes sacbes?

mites

What causes lice?

insects

What is unique about lice reproduction?

They glue eggs to the hair of host

What does Ivermectin combat?

What did bacteria Streptomyces avermitilis yield?

Ivermectin

Where was Streptomyces avermitilis origonally isolated from?

Soil in Japan

What is the mechanisim of ivermectin?

allows an influx of GABA-gated receptors (which are not present in mammals)

What is the risk of Ivermectin in mammals?

High doses can affect the brain negatively

What are Wolbachia pipientis

A symbiotic bacterium used to combat dengue fever

What is Dudingtonia flagrans?

a fungi used to inhibit roundworms

How is Dudingtonia flagrans administered?

Spores are ingested orally

How do Dudingtonia flagrans inhibit roundworms?

The spores germinate in feces and trap worm larvae inside

What is Steinernema carpocapsae used for?

Against arthropods

How does Steinernema carpocapsae kill arthropods?

kills arthropod stages by using symbiotic bacteria

harmless to other animals

Where does ivermectin come from?

Streptomyces avermitili

What gates does ivermectin target?

Glutamate gated and GABA gated Cl- channels

How is ivermectin administered?

orally

Where will you find glutamate and GABA gated Cl- cells?

the nerve cells of parasites

What is Wolbachia pipientis?

A bacteria capable of fighting dengue fever

How does Wolbachia pipientis fight denuge fever?

It is a beneficial bacteria which competes with pathogens

What does Dudingtonia flagran target?

roundworms

How does Dudingtonia flagran target roundworms?

By trapping larve in hyphae

What does the Nematode Steinernema carpocapsa target?

arthropods

How does the Nematode Steinernema carpocapsa target arthropods?

Carries symbiotic bacteria which is toxic to the arthropods

What environmental condition does the Nematode Steinernema carpocapsa require for it to be effective against arthropods and why?

moisture and for motility

Define parasitism

one individual living at the expense of another

What are parasites to their hosts?

to some degree metabolically dependent

What is a direct lifecycle?

Only one species of host

What is the name for parasites that follow a direct lifestyle?

Monoxenous parasites

What is an indirect lifecycle?

Hosts of different species

What is the definitive most?

Where the parasite reaches sexual maturity

What is the intermediate host?

required for development but not the site of sexual maturity

What are the 2 types of resting stages of protozoans?

cysts or spores

Where are protozoan parasites found?

intra or extracellular

What are protozoans similar to?

metazoan cells (multicellular animals)

Do protozoans reproduce sexually or asexually?

both

How do protozoans reproduce asexually

binary fission

How do protozoans reproduce sexually

conjugation

two protozoans fuse briefly and exchange DNA

What is the “false foot” of the protozoa called?

pseudopod

What is protozoa gliding?

actin + myosin protein puling

Which class of protozoans typically glide?

Apicomplexa

What is the most prevalent protozoan parasite

Giardia

What are giardia resistant to?

chlorine treatment

What can giardia pass through?

advanced membrane filters

Where do giardia attach?

small intestine

What are the two life forms of giardia

trophozite (food animal) and cyst

What is the large portion of the Giardia trophozite surface called?

ventral disc

What is the shape of the Giardia trophozite

pear shaped

Describe the structure of the Giardia trophozoite

Two nuclei, 4 pair of flagella, 2 median bodies

Describe the structure of the Giardia cyst

4 nuclei and oval shaped

What is the life cycle of Giardia

direct

How do Giardia infect hosts?

ingestion of cysts in contaminated goods

What triggers excitation of Giardia

gastric acid during passage through stomach

What triggers encytation of Giardia

exposure to bile salts and ph 7.8

Where are cysts of Giardia shed from the host to?

Feces

What is the causative agent of tyoxoplasmosis?

Toxoplasma gondii

Why is Toxoplasma gondii so successful?

Can infect all warm blooded animal cells

Cysts can survive inside immune cells

What is the survivable temperature range of toxoplasma gondii?

12-65

What individuals are particularly at risk from toxoplasmosis?

foetus

immuno-comprimised

sea mammels and marsupials

What can toxoplasmosis do to the intermediet host?

behavioural changes

What is the definitive host of toxoplasmosis?

felines