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What are the 5 major groupings of parasites?
nematodes, protozoa, cestodes, trematodes, ectoparasites
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What are the ectoparasites of interest in veterinary medicine?
arthropoda, specifically insecta and arachnida
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Interaction among organisms in which one organism lives with, in, or on the body of another.
symbiosis
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Symbiosis in which one organism benefit from the association while the host is harmed in some way.
parasitism
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Kind of symbiosis in which one symbiont, the commensal, benefits and the other, the host, is neither helped nor harmed.
mutualism
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Physical acts the host can do to avoid or remove the parasite.
host environment
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Advantages of parasitism for the host. (4)
outcompete others for a niche, genetic diversity/fitness, premunition/ concomitant immunity, cross-protective immunity
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What is the most important disadvantage of parasitism for the host?
inflammation: acute, subacute, and chronic
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What 3 major groupings of parasites are helminths?
nematodes, cestodes, trematodes
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Stage infective to host, no free living stage, no environmental stage, and no other host involved for development.
direct life-cycle
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Another host of vector is required for development; there is a free living stage, or the parasite develops outside of the host to an infective stage.
indirect life-cycle
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Host in which a parasite reaches sexual maturity.
definitive host
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Host that is required for parasite development but does not reach sexual maturity in, asexual.
intermediate host
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Host in which the parasite does not undergo development in, but remains alive and infective.
paratenic/transport host
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Incorrect host, may have infection but can result in dead end for parasite; lacks adaptations.
aberrant host
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Nematodes are __________ or ___________.
free-living; parasitic
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Describe the morphology of a nematode.
unsegmented, cylindrical
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Nematodes have an ______________, unlike cestodes, which do not.
alimentary canal
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The sexes of nematodes are...
usually separate
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Nematodes are aka ____________.
roundworms
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Describe the lifecycle of Ancylostoma spp.
Eggs passed in feces--> eggs hatch and develop into infective larvae --> larvae are ingested or penetrate skin --> adult worms lay eggs in small intestine --> eggs are passed in feces --> repeat cycle
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Ancylostoma are a type of __________.
nematode
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What are the transmission routes of Ancylostoma? (4)
ingestion of larvae, larval penetration through skin, transplacental, transmammary
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Giardia intestinalis and Babesia canis are examples of ____________.
protozoans
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Castodes are aka _____________.
tapeworms
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Describe the morphology of cestodes.
flat body, no cavity, scolex (head), body has proglottids (segments)
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Cestodes have a(n) ___________ life cycle with ____________.
indirect; intermediate
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Echinococcus is a type of ___________.
cestode
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Describe the lifecycle of Echinococcus.
Eggs are ingested by intermediate host --> tissues of intermediate host are ingested by definitive host --> adult worms mature in small intestine --> posterior segments of adult worms are passed in feces --> eggs are released from segments --> repeat cycle
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Trematodes are aka ___________.
flukes
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Describe the morphology of trematodes. (3)
dorso-ventrally flattened, oral and ventral suckers, have alimentary canal
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What is the sexuality of trematodes?
hermaphroditic
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Diptera are...
flies (arthropoda--> insecta)
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What are the 4 life stages of the fly?
egg--> larvae --> puparium --> adult
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Phthirptera are...
lice (arthropoda--> insecta)
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What are the 3 life stages of a louse?
egg--> nymph --> adult
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Siphonaptera are...
fleas (arhtropoda--> insecta)
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Ticks and mites are members of...
arthropoda--> arachnida
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Diplomonadida/ Trichmonadida is an order of ____________; they are __________ of the __(2)__; 2 examples include...
Protozoa; flagellates;intestine and mucosa; Giardia, Tritrichomonas
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Trypanosomatida is an order of ___________; they are __________ transmitted by ______________; 2 examples include...
Protozoa; haemoflagellates; biting insects; Trypanosoma, Leishmania
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Apicomplexa is an order of ___________; they are parasites of _________; they include... (2)
Protozoa; epithelial cells; coccidia and tissue cyst apicomplex
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With Apicomplexa, what type of reproduction takes place?
sexual and asexual
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Piroplasmorida is an order of _________; they infect _________; they reproduce by ________ in a _______ vector; 2 examples include...
Protozoa; blood cells; sexual reproduction; tick; Babesia, Theileria
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Haemosporida is an order of _________; they infect __________; they reproduce by _________ in a _________ vector; 2 examples include...
Protozoa; sexual reproduction; biting insect; Plasmodium, Haemoproteus
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Diplomonadida is _________.
Giardia
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Describe the life cycle of Giardia intestinalis (Giardia lamblia, Giardia duodenalis).
contamination of water/food/fomites with infective cysts --> ingestion --> cysts mature to trophozoites in host, which multiply and produce more cysts --> cysts and trophozoites passed in stool --> cysts persist in environment, trophozoites die --> repeat cycle
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Trophozoites of Giardia intestinalis are adapted for...
using their sucking discs to attach to the mucous epithelial cells of the upper portion of the small intestine.
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5 ways that Giardia intestinalis causes intestinal malabsorption.
secretion of proteases by intestinal cells, trophozoites produce lectin, adhere to enterocytes, fat not emulsified/ cannot be absorbed, mechanical obstruction
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A & B Giardia assemblages are found in...
humans
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C & D Giardia assemblages are found in...
dogs
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E Giardia assemblages are found in...
hoofed stock
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F Giardia assemblages are found in...
felines
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G Giardia assemblages are found in...
rats
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Giardia is asymptomatic for ________; _____ cysts are needed to initiate infection.
5-20 days; 10
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2 types of organisms from the Order Trichomonadida.
Tritrichomonas, Histomonas
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Ciliophora is an order of ____________; an example is ____________.
Protozoa; Balantidium coli
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Protozoa with a single nucleus, rodlike axostyle, undulating membrane, 3-5 flagella.
Trichomonadida
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Trichomonadida do not have a ________ stage.
cyst
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Tritrichomonas foetus is a ________ disease of __________.
venereal; cattle
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Describe the pathogenesis of Tritrichomonas foetus in bulls versus cows.
- bulls- asymptomatic chronic carriers
- cows- parasites replicate in vagina, invade uterus, and cause abortion
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How do you control Tritrichmonas foetus?
test and cull infected bulls
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Tritrichomonas blagburni causes...
feline intermittent large bowel diarrhea in young purebred cats or high density housing situations.
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Trichomonas gallinae affects the ___________ of __________.
upper respiratory tract; birds
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Transmission of Trichomonas gallinae is...
from adult crop to offspring through contaminated water or predation of infected birds.
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Trichomonas gallinae causes what kinds of lesions? (2)
necrotic ulceration, caseous lesions adherent to mucosa of oropharynx, crop, and esophagus
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Histomonas meleagridis invades the _________ of ____(4)____, where they become ________ and _________ and migrate to the ___________.
cecal wall; young turkeys, pheasant, quail, chickens (carrier); pleomorphic; amoeboid; liver
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Histomonas meleagridis causes... (3)
hemorrhagic liver, cecal inflammation and ulceration
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You can find the trophozoites of Histomonas meleagridis in the... (2)
cecum or liver.
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Transmission of Histomonas melegridis is through ___________, a __________, whereby the _____ may be ingested by an earthworm that is eaten by the definitive host.
Heterakis gallinae (transport host); cecal worm (nematode); ova
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What are the 4 stages of Trypanosoma?
epimastigote (vector), metacyclic (infective from vector to mammalian host), trypomastigote (mammalian host), amastigote (T. cruzi)
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Stage of Trypanosoma in which the undulating membrane and flagellum originate anterior to the nucleus.
epimastigote (vector)
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Infective stage of Trypanosoma, when it goes from the vector to the mammalian host.
metacyclic
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The stage of Trypanosoma in which the undulating membrane and flagellum originates at the posterior end of the parasite.
trypomastigote (mammalian host)
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The stage of Trypanosoma in which the undulating membrane is absent and the flagellum is internal.
amastigote (T. cruzi)
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What are the 2 major groups of Trypanosoma?
Salivaria (saliva), Stercoraris (feces-T. cruzi)
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Trypanosoma brucei and T. congolense are distributed throughout _________ by the ________; they cause __________ in _________ and are fatal to __(4)__; ________ native to Africa are carriers.
Africa; Tsetse fly; nagana; domestic cattle; horses, mules, camels, and dogs; wild ungulates
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Describe the lifecycle of Trypanosoma brucei.
Tsetse fly innoculates metacyclic tryps into the skin --> Tryps enter the lymph and lymph nodes then blood stream --> Tryps divide by binary fission --> trypomastigotes are in the blood --> Tsetse fly takes blood meal --> repeat cycle
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The incubation of Trypanosoma brucei is ________; clinical signs include... (8)
1-4 weeks; fever, anemia, weight loss, lymphadenopathy, splenomegaly, CNS, pooling of blood, collapse of circulatory system
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Trypanosoma equiperdum is __________ transmitted, causing disease called __________; eradicated from U but still monitored.
sexually transmitted; dourine
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During the acute stage of infection with Trypanosoma equiperdum, signs include... (5)
selling and d/c of genitalia, skin lesions, emaciation, paresis, fever
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What are the 2 forms of infection with Leishmaniasis in humans?
cutaneous/mucocutaneous, visceral
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Leishmaniasis infects...
humans, dogs, cats, horses
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How does Leishmaniasis manifest in dogs? (3)
visceral and cutaneous lesions, alopecia, non-pruritic
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How does Leishmaniasis manifest in cats and horses?
skin lesions
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Describe the life cycle of Leishmaniasis.
sandfly takes blood meal and injects promastigote into skin --> promastigotes phagocytized by macrophages --> romastigotes transform to amastigotes inside macs --> amastigotes multiply in tissues --> sandfly takes blood meal --> repeat cycle
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Leishmania promastigotes enter the blood from a ________; they are covered with _______ and _________, which mediate their uptake by __________; the parasite survives because...
vector-sandfly; GP63; lipphosphoglycan (LPG); macrophages; they survive the highly acidic environment of phagolysosome.
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Leishmaniasis causes ___________ dissemination, ________infection, and __________ due to circulating immune complexes.
systemic; chronic; glomerulonephritis
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Entamoeba histolytica exists as __(2)__.
trophozoites and cysts
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Chronic carriers of Entamoeba histolytica shed pathogen through...
dysentery with sloughing of epithelium and peritonitis
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Entamoeba histolytica is present in...
tropics, poor areas
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Describe the lifecycle of Entamoeba histolytica.
mature cysts ingested --> excystation --> trophozoites form inside host --> trophozoites multiply to create more cysts and trophozoites --> cysts and trophozoites passed in feces --> repeat cycle
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For Entamoeba histolytica the _______ is the diagnostic stage and the _______ is the infective/diagnostic stage.
trophozoite; cyst
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Primary amoebic meningoencephalitis in humans that is associated with springs, natural warm spas.
Naegleria
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Naegleria has _________ stage; humans are ________.
free-living; aberrant (dead-end) host
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Describe the life cycle of Naegleria.
cyst --> form trophozoite in environment --> becomes flagellated form --> promitosis to replicate --> amoeba penetrate nasal mucosa of human while in water --> amoeba migrate to brain via olfactory nerve --> disease --> dead end
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Balantidium coli is a _______ that is nonpathogenic in _______; it causes __________ in primates, __________ in dogs and horses.
ciliate; swine; dysentery; large bowel ulceration
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Balantidium coli has a _______ lifecycle through ________ of ________; its stages include __(2)__; it reproduces by _________.
direct; ingestion; cysts; trophozoite; cyst; binary fission
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