Superfamily Strongyloidea Flashcards
What are the general features of the superfamily strongyloidea?
Contain corona radiata Some contain teeth Contains well developed bursa Contains direct life cycles Thin shell, many cells Large buccal capsule Contain cephalic vesicle
Strongyloidea routes of tranmission?
Ingestion
Milk
Transcutaneously
What is the superfamily strongyloidea’s lifecycle?
Female lays eggs within host, eggs shed in faeces, L1- L3 in envirornment, L3 infective stage is ingested by host, moves to the site of infection –> hypobiosis / matures into adults and produces eggs.
Strongyloidea that infect horses
Known as large and small strongyles.
Strongylinae = large strongyles –> S. vulgaris, S. Edentatus, S. equinus
Triodontophorus
Cyanthostominae = small strongyles
Strongyloidea that infect ruminants
Chabertia ovina
Oesphagostomum spp.
Strongyloidea that infect pigs
Oesophagostomum spp.
Stephanurus dentatus
Strongyloidea that infects birds
Syngamus trachea
What are the main features of Strongylus vulgaris
Infects horses, very large buccal capsule, leaf crown, 2 rounded teeth, dorsal gutter
Adults located in the large intestine, caecum and colon
Larvae located in the cranial mesenteric artery –> cause major pathology.
L4 stage once in the intestine, burrow through the mucosa and enter into the submucosal arteries and migrate against the bloodflow to the cranial mesenteric artery. Spend 3-4 months in this artery before molting to L5, then return to intestine generating a nodule which ruptures. Feeds on blood and mucous
What is the parasites that contain 2 rounded teeth within horses?
Strongylus vulgaris (Large strongyle)
What is the larval parasite which is located in the cranial mesenteric artery and adult stage within the L intestine
Strongylus vulgaris (large strongyle)
What are the main features of Stronglyus Edentus?
Very large buccal capsule, no teeth, 2 leaf crown, contains dorsal gutter
Adults located in large intestine
Larvae (L3) invade the intestinal submucosa and reace the liver via the hepatic portal system. Moult to L4 within the liver and generate nodules. Travel back to intestine underneath the liver capsule to the tissues in the right flank, then move to the wall of the intestine. Generate more nodules before moving into the intestine and molting to adults.
Which species of large strongyle larvae travels from the intestine to the liver, to the right flank, back to the liver?
Strongylus edentus
Which species of horse stronglyus does not contain teeth?
Strongylus edentus
What are the main features of strongylus equinus?
Large buccal capsule, Contains three sharp teeth, dorsal tooth is the largest, contains dorsal gutter and leaf crown.
Adults located in large intestine
Larvae (L3) invade the caecum and colon and form nodules, molt to L4 within the nodules and migrate to the liver for 6+ weeks. Then migrate to the pancreas and back to the intestine. Mature into adults. Eggs shed in faeces. (eggs thin shelled, many celled)
Which horse stongylus contains 3 sharp teeth?
Strongylus Equinus (large strongyle)
Which strongylus larvae migrates to the ceacum and colon, then the liver, then pacreas and back to the large intestine?
Strongus Equinus (large strongyle)
What are the main features of the Genus Triodontophorus? Give a species example
Triodontophorous tenuciollis
Located in the caecum and colon of the horse. Feed in groups and cause ulceration. Larval stages form the nodules. L3 move into the wall of the caecum and colon to mature, L4 enter into the lumen
Contain large buccal capsule with three teeth and has an oral collar sound the mouth.
What are the main features of the subfamily cyanthostominae (small strongyles)?
Are in horses, more than 50+ species, have evolved and developed resistance.
Red in colour, short buccal capsule, located mainly in caecum and colon. Feed on mucosa
Which factors affect development within the small strongyles within Strongyloidea?
Can move into hypobiosis = common.
Determined by environmental conditions, seasons, population of parasites in GIT, immune response.
Factors that trigger the resumption of larval development is the season, antihelmithic treatment, immunosuppression
What is the lifecycle of small strongyles?
Similar to large strongyles - location difference
Eggs are typical strongylida eggs, shed in environment, L1 to L3 in environment. L3 is the infective stage where it is ingested by horses. L3 exsheath and enter the crypts of liberkuhn within the caecum and colon. Cyst formation around the glands and will surround larvae in groups.
Will either molt to L4 and emerge from nodules or undergo hypobiosis in nodules for many months which causes major pathology. Have synchronised emergence and cause death.
What types of worms infect horses and are within the Crypts of Liberkuhn in the caecum / colon?
Small strongyles
Which parasites have small buccal capsules and infect horses?
Small strongyles
What are the main features of Chabertia ovina? Which species do they infect and what is their lifecycle?
Located within the large intestine of sheep and goats (sometimes cattle).
Buccal capsule is rotated and is very large. No teeth, have corona radiata. Have a well developed bursa. Within females, they have a bent posterior end.
Similar lifecycle to other strongyloidea species. L3 infective stage is ingested, is infegested and enter into the mucosa of the small intestine. Molt to L4 before migrating to the lumen and large intestine where they mature and feed on the mucosa –> causes hemorrhage.
What are the main features of Genus Oesophagostomum?
Located within the large intestine. Hosts are ruminants and pigs. Eggs have wide poles but are thin shelled, many cells.
Generate nodules within the large intestine –> pimples –> causes peritonitis
The parasite has a shallow buccal capsule, cephalic vesicle, mouth collar and a transverse groove at the level of the vesicle.
