PID quiz 4

what is symbiosis?

an association of two organisms which can not exist independently of each other

what are symbionts?

organisms that live in close association with each other

what are 4 categories/types of symbiosis?

phoresis

mutualism

commensalism

parasitism

what is phoresis?

an association in which two organisms are merely traveling together

what is mutualism?

an association in which both organisms are benefited

what is commensalism?

an association in which one partner is benefited and the other is unaffected

what is parasitism?

an association in which one partner is benefited and the other is harmed

what is a host in parasitism?

the partner who is harmed

what is a parasite in parasitism?

the partner who is benefited

who is usually bigger the host or the parasite?

host is usually bigger

what are the 5 categories of hosts?

definitive host

intermediate host

paratenic host

reservoir

incidental host

what is a definitive host?

harbors adult/sexual stage of parasite

what is intermediate host?

harbors larval/asexual stage of parasite

what is paratenic host?

host harbors a parasite that does not undergo required development, it just transfers parasite from one host to

what also call a paratenic host?

transfer host

what is a reservoir?

an definitive host that serves to maintain the parasites life cycle in nature

what is an incidental host?

an unusual host that is unnecessary for the maintenance of the parasite in nature

all parasites have an ____ host but not all parasites have an ____ host

all have a definitive host

not all have a intermediate host

what host types are dogs in his example? hosts for what parasites?

reservoir for leishmania spp.

definitive for toxocara canis and echinococcus

whats an example of an incidental host?

trichinella spiralis in human muscle

what is a vector?

an organisms thats usually an arthropod responsible for transmitting a parasite from one host to another

what are the 2 categories of vectors? describe each

biological: parasite develops or multiplies in vector

mechanical: parasite is unchanged in vector

whats an example of a biological vector?

female anopheles mosquito

whats an example of a mechanical vector?

Houseflies carry entamoeba histolytica

what host type can biological vectors be?

definitive or intermediate

what is an example of a definitive host vector?

a mosquito for malaria parasite sexual stage

what is an example of an intermediate host vector?

a mosquito for heartworm with larval stag L1-L3

what are 3 types of parasites?

obligate

temporary

facultative

what is a temporary parasite? ex?

parasite is parasitic for limited periods for either feeding or reproduction

-ticks

what is a facultative parasite?

organisms that are normally not parasitic can survive for a limited period when they accidentally find themselves in another organism

what ae the 2 terms to describe where a parasite lives/parasitizes?

ectoparasite

endoparasite

what is an ectoparasite? where does it live?

lives on host

causes infestations

what is an endoparasite? where does it live?

lives in host

causes infections

whats an example of a human ectoparasite?

Human body louse (pediculus humanus)

what is an example of an endoparastie?

round worm (ascaris suum)

what is a zoonosis?

any disease of vertebrate animals that is transmissible to humans

what do you have to specify in zoonosis that it is from a vetrebrate animal?

if it was from an invertebrate it would be a vector

what are 7 examples of zoonosis?

trichinellosis

chagas disease

schistosomiasis

giardiasis

toxoplasmosis

amebiosis

echinoccoocsis

where do protozoa multiply?

in definitive host

do helminths multiply in definitive host?

no, they can reproduce if theres more than one helminth in the host

-helminths do not multiply as they dont just go from one to two like a bacteria or protozoa could do

for a helminth what is the severity of disease proportional to?

the worm load introduced into the host

what is host specificity?

Parasites have a specificity for a particular definitive and intermediate host as often the parasites lifecycle can only be completed in a particular host

what parasites are particularly specific?

helminths

what can disease manifestations of a host differ depending on?

whether they serve as a definitive, intermediate or incidental host

the parasites that are the best adaptive are the ___ pathogenic

least pathogenic

what is the time length of host parasite interaction specifically?

long term/chronic

do parasites adapt to every niche in host?

yes

what are 4 conditions required for endemic parasitism?

reservoir of infection

means of transmission to susceptible hosts

ability to invade and establish in new hosts

ability to reproduce

what re the 3 groups of eukaryotic organisms that affect the health and well being of animals?

protozoa

helminths

arthropods

what are 3 subtypes of helminths? what are ex of each?

nematode-roundworm

cestode-tapeworm (flatworms)

trematode-fluke (flatworms)

what type of parasitization/ what type of parasite are helminths?

endoparasites

what type of parasitization/ what type of parasite are arthropods?

ectoparasites

what are the 2 categories of arthropods that are often parasites of animals?

arachnids

insects

what is the phylum and class of roundworms?

phylum: nemathelminthes

class: nematoda

what is the phylum and class of flatowrms?

phylum: platyhelminthes

class: cestoda (tapeworms) and trematoda (flukes)

what phyla of the kingdom of protozoa are parasites to animals?

nine hyla contain at least one genus of veterinary importance

what are 4 characteristics of nematodes used to identify them?

round/cylindrical shape

have complete alimenatry canal

have celom/body cavity

sexes are usually separate

the bigger the host the ___ the parasite

bigger the parasite

what pasta do nematodes look like?

spaghetti as they are roundworms

what are 6 characteristics of cestodes used to identify them?

-flat body with no colem (body cavity)

-no alimantary canal

-hermaphroditic

-have a scolex (head) with 4 suckers (bothria)

-a strobila (body) that is segmented

-all are parasitic with an indirect life cycle

what pasta do cestodes look like?

fettuccine (as they are flatworms)

what are 5 characteristics of trematodes used to identify them?

dorso-ventrally flattened like a leaf

have an incomplete alimentary canal (one opening that acts as both mouth and anus)

no celom

hermaphroditic

have oral and ventral suckers for attachment

if given a question on test and know its a worm and it tells you that it is not hermaphroditic what worm type is it?

nematodes (roundworms) as the other 2 types are hermaphroditic

what are the 4 insect types we are focusing on as parasites? what are their orders?

flies: diptera

fleas: siphonaptera

lice: phthiraptera

hemiptera

what are the 2 arachnids we are focusing on as parasites?

ticks

mites

what are 3 characteristics use to identify if looking at an insect?

adults have 3 pairs of legs

have head, thorax and abdomen

have antenna

what are 5 characteristics use to determine if looking at arachnids?

nymphs and adults have 4 pairs or legs

larvae have 3 pairs of legs

the body is a cephalo-thorax and abdomen

have no antennae

have palps

what 3 characteristics use to determine in looking at mite/acari?

they are microscopic (less than 1mm long)

the body has scales, spines and setae

legs may have claws or suckers used to attach to host

are protozoa unicellular?

yes

what 4 things can protozoa use for locomotion?

pseudopodia

flagella

cilia

gliding movements using no locomotion organelle

what are protozoa classified by?

the mode of locomotion

how tell difference between a trophozoite and a cyst of a protozoa?

trophozoite is larger and has cilia and a kidney bean shaped nucleus

true or false all helminths including nematodes, tapeworms and flukes have complete alimentary canals?

false

which type of host would it be if there is a dog in which a larva develops to adult stage?

definitive host

which type of host would it be if theres a pig in which an egg develops into a larvae?

intermediate host

which type of host would it be if there is a cat with a protozoa that undergoes sexual reproduction?

definitive host

what are 3 life cycle types?

direct with no intermediate host

indirect with an intermediate host

indirect with a vector

whats an example of a direct life cycle with no intermediate host? explain

Intestinal hookworms

eggs are in feces which hatch and develop into larva in environment where it then can penetrate human skin and then become an adult in the human intestine and their eggs are shed out in the humans feces

whats an example of an indirect life cycle with an indirect host?

T. solium

eggs in feces in the environment which are injected by pigs who are the intermediate host. The oncosperes (eggs) hatch in pig and develop in pig muscle which can then be eaten by a human who is the definitive host where become adult in small intestine and are shed out to enviroment in human feces

whats an example of an indirect life cycle with a vector?

Meta promastigote

have procyclic promastigote which matures into metagcyclic promastigote and can infect macrophage of mammal, and can be picked up by sand fly and transferred to another mammal

Disease manifestations may be different depending on whether an animal serves as a _____, ____, or _______ ____

serves as an definitive, intermediate, or incidental host

can humans serve as both definitive and intermediate hosts? ex?

yes

human is a definitive host and a intermediate host for taenia solium

for taenia solium when a human is a definitve host what is the consequence? what about when human is an intermediate host?

definitive: generally asymptomatic

intermediate: severe consequences

are the outcomes of parasite on host highly variable?

yes

what 4 things help to determine the outcome a parasite has on a host?

-type of host (definitive vs intermediate)

-severity (infection dose and number of organisms)

-route of exposure

-if its chronic

what are 6 common routes of exposure to parasite? ex of each?

ingestion: giaradia, toxoplasma gondii, cryptosporidium, cestodes, some nematodes, some trematodes

skin or mucosal penetration: hookworm, schistosomes

transplacental (prenatal): toxoplasma gondii, toxocara canis, strongyloides stercoralis

transmammary (milk): toxocara canis, T. cati, ancylosotma caninum

arthropod bite (vector): babesia, heartworm, leishmania, tyrpanosomes

sexual intercourse: tritrichomonas foetus

where does protozoa multiply?

in host