Parasitology - Lecture 3 Flashcards
What are the general features of parasites of the superfamily Strongyloidea?
- often large buccal capsule
- mouth surrounded by corona radiata
- bursa well developed in M
- direct lifecycles
- mostly in large intestine
What are the families within the superfamily Strongyloidea?
- Family:
strongylidae
chabertiide
Syngamidae
What are the subfamilies within the family Strongylidae?
Strongylinae
Cyathostominae
What are the genuses within the subfamily strongylinae?
strongylus
Triodontophorus
What are the genuses within the subfamily Cyathosominae?
Cyathostomum
Cylicocyclus
cylicostephanus
What are the subfamilies within the family Chabertiidae?
Chabertiinae
Oesophagostominae
What are the genuses within the subfamily Chabertiinae?
chabertia
What are the genuses within the subfamily Oesophagostominae?
Oesophagostomum
What are the subfamilies within the family Syngamidae?
Syngaminae
Stephanurinae
What are the genuses within the subfamily Syngaminae?
Syngamus
Cyathostoma
What are the genuses within the subfamily Stephanurinae?
Stephanurus
What parasite genuses of the superfamily strongyloide infect horses?
Strongylus, Triodontophorus, Cyathostomum, Cylicocyclus, Cylicostephanus
What parasite genuses of the superfamily strongyloide infect ruminants?
Chabertia, Oesophagostumum
What parasite genuses of the superfamily strongyloide infect Pigs?
oesophgostomum, Stephanurus
What parasite genuses of the superfamily strongyloide infect birds?
Syngamus, Cyathostoma
Within the family Strongylidae, which subfamily are the ‘large strongyles’?
strongylinae
Within the family Strongylidae, which subfamily are the ‘small strongyles’?
cyathostominae
What species of strongylus are there?
- S. vulgarus
- S. edentatus
- S. equinus
- A. asini (not in aus)
explain the morphology of Strongylus vulgaris
size: 11-25mm
colour: dark red
anterior end: buccal capsule oval, big and contains 2 ear shaped (heart shaped) teeth and a dorsal gutter. 2 leaf crowns
posterior end (M): bursa and 2 thin, equal spicules
eggs: 90-50 microns, thin shelled, contain many cells (morula)
where do strongylus vulgaris locate in the host and what do they eat?
large intestine (caecum and colon) and eat blood and plugs of mucosa
Explain the lifecycle of strongylus vulgaris
- eggs shed in feces
- larvae develop in eggs if conditions are good and hatch
- L1-L3 develop in environment
- L3 migrate to grass where they are ingested
- L3 exsheath in SI and burrow into wall. moult to L4.
- L4 move to submucosal arterioles, migrate to cranial mesenteric artery where they spend 3-4 months before moulting to L5 (immature adults)
- L5 returns to intestine via bloodstream where they form pea sized nodules in intestine wall. these rupture to release the worms.
- PPT =6-7 months
describe the morphology of Strongylus edentatus
size: 23-44mm
anterior end: large oval buccal capsule with dorsal gutter and no teeth. 2 leaf crowns
posterior (M): bursa and 2 spicules
Where do Strongylus edentatus locate in the host?
adults: large intestine (caecum and colon)
larvae: liver and subperitoneal tissue (right flank)
describe the lifecycle of Strongylus edentatus
- L3 ingested from grass.
- L3 burrows through intestine and reaches the liver via the hepatic portal system
- L3 molt to L4 and migrate throughout the liver, creting nodules.
- L4 travels via hepatic ligment to the subperitoneal tissues on the right flank
- worms return to intestine via mesentery where they form nodules which release parasites into lumen
- PPT = 10-12 months
Describe the morphology of Strongylus equinus
size: 25-55mm
anterior end: big oval buccal capsule with 3 teeth. dorsal tooth bigger with a bifid tip and a dorsal gutter. 2 leaf crowns
where do strongylus equinus locate in the host?
adults: large intestine (caecum and colon)
larvae: liver and pancreas
describe the lifecycle of strongylus equinus
- L3 ingested and form nodules on wall of caecum and colon.
- molt to L4 in nodules and travel to liver across peritoneal cavity (takes 6+ weeks)
- no nodules formed from liver migration
- migrate to the pancreas before reaching the intestine
PPT = 8-9 months
What is the location in the host of parasites of the genus tridontophorus? and what species does it infect?
caecum and colon of equids
Describe the general morphology of parasites of the genus Triodontophorus
size: 9-25mm
anterior end: buccal capsule subglobular, thick walled, 3 radially arranged teeth that are half buccal capsule length, well developed dorsal gutter. has a mouth/ oral collar and leaf crowns
What is a species of the genus Triodontophorus?
T. tenuicollis
Describe the lifecycle of Triodontophorus tenuicollis
- host ingests L3
- L3 enter wall of cecum and colon, molt to L4
- L4 emerges into lumen
- molt to adult while in lumen
PPT = 9 weeks
Describe the feeding of Triodontophorus tenuicollis
- plug feeders and blood suckers
- feed in groups/ nests
- cause ulceration and blood loss
How many species are there within the subfamily Cyathostominae?
more than 50
Describe the general morphology of worms within the subfamily Cyathostominae
size: <1.5cm
colour: red sometimes
anterior end: buccal capsule short and cylindrical or ring shaped. Most dont have teeth
eggs: thin shelled, morula stage
what is the location in the host of parasites of the subfamily Cyathostominae?
caecum and colon
Describe the lifecycle of worms of the subfamily Cyathostominae
- eggs laid. L1 forms inside the egg, then hatches.
- ingested L3
- L3 exsheaths and enters glands of Lieberkuhn in caecum and colon.
- host forms a cyst around parasite, where it will develop
- L3 can either molt to L4, emerge from cyst and molt to adult. or persist as inhibited L3 for up to 2.5 years
- emergence of parasites into lumen is major pthogenic event. they all emerge at once and can kill the host
PPT = 5-6 to 18 weeks
What factors are involved in ‘inhibited’ development?
- environmental
- population of cyathostomes in the GIT
- immune response
What factors can trigger the resumption of larval development and emergence from nodules in Cyathostomes
- change in season
- anthelmintic treatments (removal of worms from GIT might trigger replacements)
- immunosuppression
What species from the superfamily Strongyloidea infect ruminants?
- Chabertia ovina
- Oesophagostomum spp.
Describe the morphology of Chabertia ovina?
size: 14-20mm
anterior end: large, subglobular buccal capsule, opens anteroventrally. small leaf crowns. transverse and ventral cervical groove
posterior end (M): bursa well developed.
posterior end (F): short tail, sharply reduced posterior to anus and ends in dorsally curved point
eggs: 90-50 microns, thin shelled, many cells inside (morula)
describe the lifecycle of Chabertia ovina
- L3 ingested with pasture
- L3 exsheath and enter mucosa of SI
- moult to L4 after 1 week
- L4 returns to lumen and migrates to LI where they moult to adults
PPT = 6-7 weeks
Where do oesophagostomum spp. locate in in the host? what hosts?
large intestine of ruminants, pigs, etc.
Describe the general morphology of Oesophagostomum spp.
anterior end: mouth surrounded by mouth collar. shallow, cylindrical and ring shaped buccal capsule. cervical groove present. cuticle between mouth and ventral groove is inflated to form a cephalic vesicle.
What is the host and location in the host of Oesophagostomum columbianum?
large intestine of sheep, goats, etc.
What is the host and location in the host of Oesophagostomum venulosum?
large intestine of sheep, goats, etc.
What is the host and location in the host of Oesophagostomum radiatum?
large intestine of cattle
Describe the general lifecycle of Oesophagostomum spp.
-eggs shed in poop
- L1-L3 in environment, then ingested with pasture
- L3 enters mucosa of any part of intestine (sml or lrg) and forms nodules. molts to L4 in nodules
- L4 leavs nodules and molts to adult in lumen of lrg intestine.
PPT = 6 weeks
What condition is caused by infection of Oesophagostomum spp. in the gut wall?
peritonitis (perforation of the intestine)
What species from the superfamily Strongyloidea infect pigs?
Oesophagostomum spp.
Stephanurus dentatus
Describe the morphology of Oesophagostomum dentatum
- stout, whitish body, up to 14mm long
- cephalic vesicle prominent
- almost absent cervical alae
- cervical papillae: towards posterior end of oesophgus
- eggs: ovoid, thin shelled. many cells inside (morula)
What species and where does Oesophagostomum dentatum infect?
large intestine of pigs
Describe the lifecycle of Oesophagostomum dentatum
similar to other species of oesophagostomum, except L3 mainly enters to mucosa of the lrg intestine (instead of both lrg and sml) and cause nodules.
What is a common name for Oesophagostomum dentatum?
nodule worm of the pig
What is a common name for Stephanurus dentatus?
kidney worm
Where do adult Stephanurus dentatus worms locate in the host?
- perirenal fat in cysts that are connected to the pelvis of the kidney or to the uterus.
- pelvis of the kidney and walls of the ureters
Where do larvae Stephanurus dentatus worms locate in the host?
liver, peritoneal cavity and other organs
Describe the morphology of Stephanurus dentatus
- lrg, stout worms M= 2-3cm F= 3-5cm
- cuticle is very transparent (easily see organs)
- cup shaped buccal capsule, small leaf crown
- triangular teeth at base of buccal capsule
- M have a small bursa, rays are short
- tail of F is short and stumpy
- eggs: thin shelled, 32-64 cells (morula)
describe the lifecycle of Stephanurus dentatus
- eggs passed in urine
- L1-L3 in environment
- earthworms may serve as transport host
- infection via ingestion of L3 in food, water or earthworms. also percutaneously
- molt to L4 after ingestion and migrate to liver via portal vein
- final molt in liver and wander in parenchyma of liverfor 3-9 months
- pierce liver capsule and migrate to perirenal region
- immature adults perforate walls of ureters, form cysts and sexual mature
- PPT = 6-12 months
What species from the superfamily Strongyloidea infect birds?
Syngamus trachea
What is a common name for Syngamus trachea? Why is it named that?
gape worm. because the bird has its mouth gaping open
What are the hosts and location within the host of Syngamus trachea? What does it feed on?
- turkey, fowl, pheasants, etc.
- trachea.
- blood
Describe the morphology of Syngamus trachea
- female and male always coupled and has a Y shape
- red colour when fresh
- eggs: ellipsoidal shape, operculum at each pole, relatively thick shelled, morula stage
Describe the lifecycle of Syngamus trachea
- eggs coughed up, swallowed and pooped into environment
- L1-L3 within egg.
- infection of host by ingestion of eggs with L3, free L3 (not very resistant) or paratenic host containing L3 (earthworms, slugs, snails, etc.).
- L3 travel to liver, lungs (moults twice) and trachea
PPT= 16-20 days
