PaRaSiToLoGy Practicals 1 Nematodes - trematodes srjp_011686.
-
Upload
curtis-francis -
Category
Documents
-
view
232 -
download
1
Transcript of PaRaSiToLoGy Practicals 1 Nematodes - trematodes srjp_011686.
PaRaSiToLoGy Practicals 1
Nematodes - trematodes
srjp_011686
Enterobius vermicularis ova
• D-shaped
• Scratching of the perianal area leads to hand contamination with infective ova and reinfection of the host
Enterobius vermicularis - Male Enterobius vermicularis - Female
Strongly curved ventral end and conspicuous copulatory spicule
Pointed tail in females; more
frequently found in cellophane
tape preparations
Common name: PINWORM
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
Trichuris trichiura - female
Common Name: WHIP WORM
Trichuris trichiura – male worm
• characteristically coiled tail
Trichuris trichiura – cross section appendix
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.
Capillaria philippinensis ova
• “peanut shaped”
• unembryonated fertile eggs
• striated shells and inconspicuous polar prominences
Capillaria philippinensis - adult worm
• Common name: “PUDOC WORM”
• Diagnostic stage: unembroyenated egg, fertilized egg and larva
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.
Ancylostoma caninum – adult female worm
Ancylostoma caninum – adult male worm
Ancylostoma caninum
The anterior portion of the of an adult is responsible for the
attachment which is known as the mouth part. Has 3
cutting plates.
Hookworm – adult male
Hookworm – adult female
Necator americanus – mouth part
Hookworm – rhabtidiform larvae
Hookworm – filariform 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 (rhabtidiform larva)
• maybe confused with strongyloides larva normally passed in feces
• has long, tubular, buccal canal and the genital primordium cannot be seen
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 - 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
Ascaris lumbricoides – unfertilized ovum
Has a poorly developed irregular mammillated layer.
Ascaris lumbricoides – fertilized ovum
Presence of mammillated external layer of the thick shell; one stage cell normally found
in feces.
Ascaris lumbricoides – embryonated ovum
Ascaris lumbricoides – decorticated ovum
The outer albuminoid,
mammillated layer is absent.
Males: curved tail
Females: straight tail
Intermediate host for Schistosoma japonicum
Schistosoma japonicum ova in human intestine
Schistosoma japonicum ova in x-section appendix
Ascaris lumbricoides – embryonated ovum
Schistosoma japonicum ova in liver
Schistosoma japonicum ova in spleen
Schistosoma japonicum ova in human brain
Note: kahit ako, hindi ko makita yung ova sa mga organ. Sorry, ito lang kasi yung nakita kong pix…
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”
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
male
Schistosoma japonicum – adult
female
Schistosoma japonicum – ova
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