Parasites: General Concepts & Ectoparasites Flashcards
- key concepts with parasites - mode of infection - types of hosts - life cycle - parasite fitness/survival - food - life cycle strategies - host-parasite balance
microspora
- Phylum: Microsporidia
- obligate, intracellular protozoan parasites
- spore-forming
- infecting every major animal group
zoonotic microsporidia have to overcome 2 obstacles
- more advance immune systems
2. much higher body temps
mammalian species
Enterocytozoon bieneusi
facultative parasite
organism that may become parasitic, but does not require a host for completion of its life cycle
- e.g. Blastomyces dermatitidis, Blastomycosis (fungi)
opportunistic infection
infection caused by pathogens (bacteria, viruses, fungi, or protozoa) that take advantage of an opportunity not normally available such as host weakened immune system, altered microbiota or breached integumentary barriers
parasitism
when organism for all or part of its life derives at least some, but often all of it’s food from a living organism of another species (host)
- ONE WHO EATS AT ANOTHER’S TABLE
ectoparasite
flea living on a dog; flea feeds on dog’s blood which is detrimental to dog
ectoparasite
caligid copepod (sea lice) living on skin of fish - but these parasites spend part of their life cycle as free-living
endoparasite
cestode platyhelminth living in intestine of fish and mammals
parasitism
Ht - x or X
commensalism
Ht +/- 0 (-x)
mutualism
Ht + Y
Helminths
- parasitic worms
- large
- multicellular
- vermiform or “worm-like” in form
Phylum Nematoda
roundworms
Phylum Platyhelminthes
flatworms
Class Cestoda
tapeworms
Class Trematoda
flukes: endoparasites
Class Monogenea
skin flukes: ectoparasites
Class Turbellaria
free-living flatworms, some parasitic forms
Phylum Acanthocephala
thorny-headed worms
Phylum Annelida
segmented worms
- not parasitic (leeches)
Kingdom Protozoa
- Phylum Mastigophora (flagellates)
- Phylum Apicomplexa
- Phylum Ciliphora (ciliates)
Kingdom Animalia
- Phylum Arthropoda insects/arachnids, copepods)
- Phylum Cnidaria (Myxozoa)
parasitism
non-mutual non-symbiotic relationship btwn species, where one species (parasite) benefits at the expense of the other (host)
ectoparasite
live on their host
endoparasite
live in their host
parasites
- smaller than their host
- reduce host biological fitness to some extent (pathogenicity/virulence)
- typically do not kill their host
- reproduce at a faster rate than their host