Principles of parasitism Flashcards
commensalism
reproduce in the host but not a true parasite
parasitism
interferes with host
metabolic dependency of one organism upon a second
fitness characterized by parasite’s ability to:
become established in host
resist environmental stresses
survive host defenses
reproduce and disseminate its progeny
obligatory parasite
cannot complete its lifecycle without spending part or all of its time on or within a host
may use successive series of different hosts
may have free-living stages
facultative parasite
become parasitic when eaten or opportunistically enter host
endoparasite
organism living within host environment
ectoparasite
organism living on host
aberrant parasite
organisms found in locations where they do not normally occur
-do not mature/ facilitate transmission, result in disease state
accidental/ incidental parasite
enter or attach to host species different from ones which normally associated
repeated successful colonization can develop new host association
may not survive on host
pseudoparasite
diagnostic parasite stages that resemble protozoan cysts in feces, blood or urine
hyperparasite
when parasitic organism is host to another parasite species
definitive host
parasite attains reproductive maturity
circulation or passage of progeny capable of colonizing additional host species
intermediate host
larval or intermediate stage parasite must undergo development to become infective for final host
often required developmental stage for completion of life cycle
paratenic host
host used by larvae/ intermediate stage to facilitate transmission to final host
do not undergo development!!
bridges ecological gap between passage of infective stages and successful transmission
reservoir host
maintain a parasite in population at sufficient levels to facilitate its transmission between hosts
may be definitive, intermediate, or paratenic
emphasis on population rather than individual!!
