Lecture 1 Flashcards
host
organism being lived off of; drawing nutrients from and developing in
parasite
organism living off another organism. usually benefit for parasite, not host
definitive host
the end host; the host where any type of sexual repro is occurring
intermediate host
a host in betwen. will have no sexual repro in that intermediate host, maybe asexual repro or migration, but key is no sexual repro
paratenic (transport host)
parasite gets in and holds onto parasite until they are eaten by definitive host. the parasite will encyst - attach themselves and wait to be eaten by the definitive host
mechanical vector
no encystment, no migration, no asexual or sexual repro. its basically carried from one host to the next.
an ex: a fly that is feeding on blood. the blood gets all over its mouthparts which could contain a parasite. then when fly takes next bloodmeal it can transmit the parasite to the next host.
prepatent period
when your host ingests an infected stage and the parasite will develop in that host, once its developed you will see diagnostic stages recovered in feces.
–> time from infection of a parasite until diagnostic stages can be recovered from host.
patent period
period of time parasite can be detected through various diagnostic techniques.
the big 3 groups of parasites
protozoans (microscopic)
helminths - worms
arthropods - insects & arachnids
what do protozoans consist of?
amoebas, ciliates, flagellates, apicomplexans
what are the phylums of helminths?
platyhelminths = flatworms nematodes = traditional worms like roundworms acanthocephalans = thorny head worms
what are the classes of platyhelminthes?
trematdoes = flukes cestodes = tapeworms
symbiosis
living together
phoresis
traveling together
commensalism
one benefits and the other is neither helped nor harmed
ex: birds around cattle
mutualism
all members benefit
ex: bacteria in cattle
parasitism
the parasite benefits at the expense of the host
endoparasite
parasite on the inside of the body. when this happens you are said to be “infected”
ectoparasite
parasite on the outside of the body. when this occurs it is said to be an infestation
obligate
a parasite that has to live in host in order to complete their life cycle and survive.
ex: ticks
facultative parasite
can complete their lifecycle somewhere else; they don’t need a host.
ex: blowflies - they can lay their eggs pretty much anywhere
temporary
can only come to host when they need something specific (like a mosquito)
continuous parasite
a parasite that has to be on or in a host at all times in order to survive.
ex: lice
parasitIASIS
when an animal is infected with a parasite but looks great
parasitOSIS
an animal infected with a parasite that IS showing outward signs of disease
sylvatic cycles
involve parasites of wild animals infecting humans
urban or domestic cycles
involve parasites of companion or food animals or of domestic pests (like rats or mice) infecting humans
2 methods of evolution of parasitism
- parasite co-evolved with host (less pathogenic)
- parasite more recently colonized host (more pathogenic; a result of keeping animal in environment for which they are not adapted like alpacas in FL)
how parasites escape immunity
- molecular mimicry
- antigenic variation
- secretion of substances that disable the immune system
molecular mimicry
mimicking linear amino acid epitopes of vertebrate hosts
antigenic variation
continuing evolving things like new surface glycoproteins eluding destruction by host
mechanisms to increase fecundity
- produce large numbers of eggs or cysts
- hermaphroditism
- asexual reproduction
provosis
covered in spines
euryxenous
infect a wide variety of hosts
stenoxenous
extremely host specific
