1. Practicals 1 Nematodes - trematodes
PaRaSiToLoGy
Practicals 1
Nematodes - trematodes
srjp_011686

2. Enterobius vermicularis ova
D-shaped
Scratching of the perianal area leads to hand contamination with infective ova and reinfection of the host

3. Enterobius vermicularis - Female Enterobius vermicularis - Male
Common name: PINWORM
Enterobius vermicularis - Female
Enterobius vermicularis - Male
Pointed tail in females; more frequently found in cellophane tape preparations
Strongly curved ventral end and conspicuous copulatory spicule

5. Trichuris trichiura (fertilized ova)
smooth shell with polar prominences, known as polar “plugs”
“football shaped”; “chinese lantern”
female worm shed 3,000 and 20,000 eggs per day
requires tropical temperature for embryonation to occur
an infective egg can survive for 1 year

6. Trichuris trichiura - female
Common Name: WHIP WORM
Trichuris trichiura - female

7. Trichuris trichiura – male worm
characteristically coiled tail
Trichuris trichiura – cross section appendix

8. Trichinella spiralis ( Muscle Worm)
Cosmopolitan in distribution
when infective larvae in inadequately cooked pork is ingested, they reach maturity in the intestine
larvae enters the bloodstream and are carried to the muscle tissue throughout the body
pigs and rats are the most important reservoir hosts in nature
Larvae are most abundant in tongue, masseter muscle, diaphragm and other active muscle tissues.

9. Capillaria philippinensis ova
“peanut shaped”
unembryonated fertile eggs
striated shells and inconspicuous polar prominences

10. Capillaria philippinensis - adult worm
Common name: “PUDOC WORM”
Diagnostic stage: unembroyenated egg, fertilized egg and larva

11. Ancylostoma braziliense – female worm
Ancylostoma braziliense – male worm
Ancylostoma species
The posterior end of the male has a broad transluscent membranous caudal bursa with rib like rays and spicule which is used for attachment to the female during copulation.

13. Ancylostoma caninum – adult female worm
The anterior portion of the of an adult is responsible for the attachment which is known as the mouth part. Has 3 cutting plates.
Ancylostoma caninum – adult male worm

15. Necator americanus – mouth part Hookworm – adult female
Hookworm – adult male
Necator americanus – mouth part
Hookworm – adult female

18. Hookworm (rhabtidiform larva)
maybe confused with strongyloides larva normally passed in feces
has long, tubular, buccal canal and the genital primordium cannot be seen
Hookworm – rhabtidiform larvae
Hookworm (3rd stage, filariform larva)
much longer and more slender than the rhabtiditoid form
short esophagus, long intestine, pointed tail
this stage is usually found in soil or in feces cultured for 5 days or longer
Hookworm – filariform larvae

19. Strongyloides stercoralis - rhabditiform
If free living female in feces, are allowed to stand at room temperature and remain moist for 2-3 days, the rhabditoid larva may develop into free living adult
Strongyloides stercoralis - rhabditiform
Strongyloides Stercoralis - Filariform
3rd stage, infective stage
longer and slender than rhabditoid stage
differentiated from hookworm filariform by its long esophagus, equal in length intestine, and by its blunt, notched tail
Parasitic females rarely are seen in feces
Strongyloides stercoralis - filariform

21. Ascaris lumbricoides – unfertilized ovum
Ascaris lumbricoides – embryonated ovum
Has a poorly developed irregular mammillated layer.
Ascaris lumbricoides – fertilized ovum
The outer albuminoid, mammillated layer is absent.
Ascaris lumbricoides – decorticated ovum
Presence of mammillated external layer of the thick shell; one stage cell normally found in feces.

22. Males: curved tail
Females: straight tail

26. Intermediate host for Schistosoma japonicum
Ascaris lumbricoides – embryonated ovum
Schistosoma japonicum ova in x-section appendix
Intermediate host for Schistosoma japonicum
Schistosoma japonicum ova in liver
Schistosoma japonicum ova in human intestine

27. Schistosoma japonicum ova in human brain
Schistosoma japonicum ova in spleen
Note: kahit ako, hindi ko makita yung ova sa mga organ. Sorry, ito lang kasi yung nakita kong pix…

28. Schistosoma spp: cercaria are the infective forms
Schistosoma spp: cercaria are the infective forms. After encountering the skin, the cercariae penetrate and lose the tail transforming into schistosomulae.
Known as the “forked tail cercaria”

29. Schistosoma japonicum – adult male
Schistosoma japonicum – in copula
adult schistosomes live in pairs in the portal system and in mesenteric venules
Females are slender and longer; are held in the gynecophoric canal during copulation
Males have a ventral infolding from the ventral sucker to the posterior end forming the gynecophoric canal
Schistosoma japonicum – adult female

30. Schistosoma japonicum – ova
smaller than those of S. haematobium and S. mansoni
Ovoid and has thin clear shell
a small spine or hook on its lateral margin that may be inconspicuous or difficult to see
contains a miracidium when passed into the feces
Schistosoma japonicum – ova