3.1 - ASCARIS LUMBRICOIDES Flashcards
Phylum
Nemathelminthes
Class
Nematoda
3 types of musculature of nematodes
- polymyarian
- meromyarian
- holomyarian
more than five rows of cells
polymyarian
between two to five rows of cells
meromyarian
less than two rows of cells
holomyarian
Intestinal Species (7)
- Ascaris lumbricoides
- Trichuris trichiura
- Enterobius vermicularis
- Capillaria philippinensis
- Ancylostoma duodenale
- Necator americanus
- Strongyloides stercoralis
Tissue Species (2)
Blood Species (4)
- Trichinella spiralis
- Dracunculus medinensis
Blood Species:
- Wuchereria bancrofti
- Brugia malayi
- Onchocerca volvulus
- Loa loa
Animal Species
- Ancylostoma caninum
- Ancylostoma braziliense
- Toxocara cati
- Toxocara canis
- nonsegmented, cylindrical, symmetrical
- cuticle - protective covering
- complete digestive tract
- dioecious - separate sexes
- chemoreceptors
General Morphology of Nematodes
chemoreceptors
- amphid
- aphasmid
- phasmid
amphid
with head/cephalic
aphasmid
absence of phasmid (tail)
phasmid
with tail/caudal
all nematodes have ?
amphids
all nematodes have phasmids except: (they have ?)
- Trichuris trichiura
- Capillaria philippinensis
- Trichinella spiralis
stichocytes (secretory cells)
all nematodes inhabit the small intestine except: (what do they inhabit?)
- Enterobius vermicularis
- Trichuris trichiura
large intestine
life cycle of nematodes
eggs
- unfertilized
- fertilized
- embryonated –> infective stage
larva
- rhabditiform
- filariform (3rd larval stage, infective stage, L3)
adult –> most mature stage
MOT: ingestion
through eggs
Ascaris, Trichuris, Enterobius
MOT: ingestion
through larva
Capillaria, Angiostrongylus, Trichinella
MOT: skin penetration
Hookworms, Strongyloides
MOT: inhalation
Enterobius vermicularis
MOT: transmammary
S. stercoralis, A. duodenale
MOT: vectors
filarial worms
common names
Ascaris lumbricoides
giant intestinal round worm
common names
Enterobius vermicularis
pin worm, seat worm, society worm
common names
Trichuris trichiura
human whip worm
common names
Capillaria philippinensis
pudoc worm
common names
Ancylostoma duodenale
old world hookworm
common names
Necator americanus
new world hookworm/American murderer
common names
Strongyloides stercoralis
Threadworm
common names
Ancylostoma caninum
dog hookworm
common names
Ancylostoma braziliense
cat hookworm
common names
Ancylostoma ceylanicum
civet cat found in Ceylon Sri Lanka
- largest intestinal roundworm
- soil transmitted helminth
Ascaris lumbricoides
definitive host of A. lumbricoides
man
habitat of A. lumbricoides
small intestine
MOT of A. lumbricoides
ingestion of eggs
infective stage of A. lumbricoides
embryonated egg
diagnostic stage of A. lumbricoides
egg and adult worm
- creamy-white to pink in color
- oviparous (unembryonated eggs)
- spicules (copulatory organs)
general morphology of A. lumbricoides
unique diagnostic feature of A. lumbricoides
trilobate lips
- 20-35 cm in length
- pointed or straight tail
- oviparous (200,000 eggs per day)
female adult A. lumbricoides
- <30cm length
- curved tail, bent or coiled
- spicules
male adult A. lumbricoides
- 88um to 94um by 39 to 44um
- Longer, Narrower
- More oval or oblong in shape
- Thin Egg Shell
- Irregular mammilated coating with refractile granules
- Outer layer of the unfertilized egg
- will never mature
- sign that female adults are inside
unfertilized eggs
- 45 to 70um by 35 to 50um
- Coarsely mammillated albuminous covering
- Thick outer layer as supporting structure
- Delicate vitelline, lipoidal inner membrane
- Underneath the thick mammilated albuminous covering
- more defined
- capable of embryonation
fertilized eggs
outer layer of fertilized egg
coarsely mammillated albuminous covering
middle layer of fertilized egg
glycogen layer
inner layer of fertilized egg
lipoidal inner membrane
- infective mature stage
- needs soil to be ?
- contains the larvae
- can be corticated or decorticated
embryonated eggs
thick outer shell
corticated
lost the mammillated covering
decorticated
it takes ? for fertilized eggs to become embryonated and to be infective
2-3 weeks
life cycle of ascaris
- mouth
- small intestine
- lymphatic vessel
- lungs
- throat
- cough
- swallow
- small intestine
- adult
- mate
- feces
- soil
- embryonate
the female ascaris lays ? eggs per day
200,000
- ascariasis
- Loffler syndrome
- bowel obstruction with fever and malaise
- intestinal perforation and migration
- occlusion of appendix
- lactose maldigestion
pathogenesis and clinical manifestations
Ascaris infection
Ascariasis
- pneumonitis
- Disease manifested during lung migration
- Bilateral diffuse, mottled pulmonary infiltrates and mild bronchitis associated with peripheral eosinophilia
Loffler Syndrome
Virulence Factors
- Pepsin inhibitor 3 (PI-3)
- Phosphorylcholine
- Pepsin: enzyme produced by the parietal cells of the stomach that aids in protein or food digestion
- Protects worm from digestion
- Safely pass through the stomach and lodge into the small intestine
- Evade the juices of digestive tract
Pepsin Inhibitor 3 (PI-3)
Suppresses lymphocyte proliferation
Phosphorylcholine
diagnosis
- DFS
- kato thick smear
- concentration test
extraintestinal organs affected by ascaris
liver, gallbladder, pancreas, bile ducts,
- An estimated 807 million-1.3 billion people in the world
- Poor personal hygiene, poor sanitation, and in places where human feces are used as fertilizer
epidemiology
treatment
drug of choice: albendazole
related to Ascaris lumbricoides
Ascaris suum
common name of Ascaris suum
pig roundworm
Ascaris suum is high risk for people who?
raise pigs or use raw pig manure as fertilizer
