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1. a plant or animal that lives upon or within another living organism at whose expense it obtains some advantage; see also symbiosis. Parasites include multicelled and single-celled animals, fungi, and bacteria, and some authorities also include viruses.Those that feed upon human hosts can cause diseases ranging from the mildly annoying to the severe or even fatal. (See accompanying table.)
2. parasitic fetus.adj., adj parasit´ic.
accidental parasite one that parasitizes an organism other than the usual host.
facultative parasite one that may be parasitic upon another organism but can exist independently.
incidental parasite accidental parasite.
malarial parasite Plasmodium.
obligate parasite (obligatory parasite) one that is entirely dependent upon a host for its survival.
periodic parasite one that parasitizes a host for short periods.
temporary parasite one that lives free of its host during part of its life cycle.
Rhabditis/Rhab·di·tis/ (rab-di´tis) a genus of minute nematodes found mostly in damp earth, and as an accidental parasite in humans.
Rhabditis(răb-dī′tĭs) [Gr. rhabdos, rod]
A genus of small nematode worms, some of which are parasitic.
a genus of minute nematodes found mostly in damp earth but they may temporarily invade damaged skin; members of the family Rhabditidae.
not recorded as pathogenic.
causes bovine parasitic otitis and secondary myiasis.
Rhabditis clavopapillata, Rhabditis macrocerca
found as a contaminant on the hair of dogs and monkeys.
found in a granuloma of the gum in a horse.