Lecture 2: Cestodes Flashcards
cestodes are
tapeworms
phylum for tapeworms
platyhelminthes “flatworms” which includes trematodes “flukes” and cestodes “tapeworms”
Class Cestoda includes Orders
Cyclophyllidea “true tapeworms” like Dipylidium caninum
Pseudophyllidea “psuedotapeworms” like Spirometra mansonides
morphological recap of cyclophyllidean tapeworms
hermaphroditic (like most flukes)
always endoparasitic
adults lack digestive tract, but have muscular system to move
scolex (head) contains four suckers/acetabula
armed or unarmed (hooks)
germinal neck and body (strobila) with segments (proglottids)
more mature proglottids are farther from scolex
each proglottid contains excretory system, nervous system and is hermaphroditic
cyclophyllidean tapes only have a __ pore
genital
hermaphroditic
pseudophyllidean tapes have a __ and __ pore but are still hermaphroditic
uterine and male genital pore
cucumber seed tapeworm
diphylidium caninum
distribution of dipylidium caninum
worldwide
DH of diphylidium caninum
dogs, cats, humans
IH for dipylidium caninum
fleas (ctenocephalides felis, c. canis, pulex irritans) and dog lous (trichodectes canis)
juvi tapeworm is called a
cysticercoid (metacestode), each is one adult/one scolex
diphylidium caninum reproductive system
2 sets of reproductive organs / proglottid and genital pores on the lateral aspects of proglotids
scolex of diphylidium caninum
4 circular suckers/acetabulum
ARMED (hooks)
eggs of dipylidium caninum
packets with up to 65eggs/packet
6 hooked hexacanth embryos inside eggs
will need to smash up proglottid to get egg packets
proglottids of dipylidium caninum can be found
in feces, in pet beds, in fur around anus
look like cucumber seeds
LC of dipylidium caninum
proglottids shed in feces
rupture and release egg packets
eggs ingested by IH (flea or louse larvae)
hexacanth embryo mature to cysticercoid inside adult flea w/in 36hr when it is on the DH (temperature triggers)
flea is ingested by DH, scolex attaches to SI
what is unique about the d. caninum LC
Embryo matures to cysticercoid once flea is on the DH!
treatment for d. caninum
can be difficult or easy
must control fleas/lice
treat tapes with praziquantel, fenbendazole once IH is gone
taeniid type tapeworms
long rectangular proglottids
large worms
usually ARMED
single genital pore per proglottid (d. caninum has 2 genital pores)
unique eggs but can’t tell which taeniid spp by looking at eggs
general taeniid LC
Adults in SI of DH
proglottids passed in feces
IH ingests eggs (hexacanth embryo) released and penetrates intestinal mucosa to enter circulation
metacestode stage developes in various organs/tissues
DH ingests raw meat with metacestodes
mutton tapeworm
taenia ovis
DH taenia ovis
SI of dog
metacestode of Taenia ovis
skeletal and cardiac muscle of sheep and goats (masseter, heart, diaphragm)
ruminant tapeworm of dogs or abdominal bladderworm
taenia hydatigena
adult taenia hydatigena
SI of dogs
metacestode of taenia hydatigena
peritoneal cavity of sheep and goats (serosal surfaces of abdominal organs and liver)
rabbit tapeworm or abdominal bladderowrm
taenia pisiformis
metacestode of taenia pisiformis
peritoneal cavity of rabbits (serosal surfaces of abdominal organs)
feline taeniid or strobilocercus of rats
taenia taeniaeformis
adult taenia taeniaeformis
SI of felids
metacestode of taenia taeniaeformis
liver of rats and mice
metacestode is a __ in case of taenia taeniaeformis vs other dog taenia discussed were ___
strobilocercus (single non-invaginated scolex attached to bladder)
cysticercus (single invaginated scolex “inside out scolex” )
this taeniae tapeworm is found in SI of dogs and the metacestode stage is a unilocular hydatid cyst
echinococcus granulosus
short tapeworm, metacestode stage contains a large bladder filled with hundreds of scolices that acts as a brood capsule and is also termed to look like ‘hydatid sand” (unilocular hydatid cyst)
which taeniid has zoonotic potential
echinococcus granulosus
be cautious with all taeniids bc the eggs all look alike
echinococcus granulosus metacestode stage is found
liver, lung, brain of cattle, sheep, horses, pigs, humans (unilocular hydatid cyst) - can try to sx remove depending on location
scary tiny tapeworm that makes a thin multilocular hydatid cyst
echinococcus multilocularis
metacestode stages of echinococcus multilocularis are found in what animals
rodents and humans (liver, lungs, brain, other)
contains thousands of brood capsules each containing hundreds of protoscolices
multilocular hydatid cyst of echinococcus multilocularis tapeworm
sheep coenurus tapeworm or gid bladderworm
taenia multiceps
taenia multiceps metacestode is found where
brain/SC of sheep and goats. Metacestode is a coenurus (large fluid filled bladder with several hundred scolices)
rabbit coenurus tapeworm or subcutaneous bladderworm
taenia serialis
taenia serialis is metacestode is found where
SC and IM c.t. of the RABBIT, metacestode is a coenurus (fluid filled bladder with hundreds of scolices lined up into rows
what is different from the coenurus of taenia serialis vs. taenia multiceps
scolices line up in rows
which Taeniid tapeworms have 1 adult metacestode types
T. ovis, hydatigena, pisiformis (cysticercus metacestode)
T. taeniaeformis (strobilocercus metacestode)
which Taeniid tapeworms have thousands of adults in metacestode type
echinococcus granulosum (unilocular hydatid cyst) and multilocularis (multilocular hydatid cyst)
which taeniid tapeworm metacestode types have hundreds of adults
taenia multiceps and serialis (coenurus)
diagnosing taeniid tapeworms
fecal float
high specific gravity
adult
treatment options for taeniid tapeworms
praziquantel
fenbendazole
spirometra mansonoides
pseudophyllidean tapeworm of dogs, cats, and raccoons
zoonotic
one set of reproductive organs, uterine pores, and scolex with 2 bothria
spirometra mansonoides
will see black dots down middle
stages of spirometra mansonoides
operculated eggs ciliated coracidium metacestode stages: procercoid in 1IH copepod ( Plerocercoid in 2IH (frog, rat, snake, NOT a fish)
Life cycle of spirometra mansonoides
adults in SI cat/dog
eggs passed in feces via uterine pore (operculated)
copepod eats coracidium
procercoid in copepod is eaten by frog, rate, stank
plerocercoid or sparganum encysts in muscels of 2IH and is eaten by DH
plerocercoid that is encysted
sparganum (ie frog legs with sparganum cysts = pseudo tapeworms)
is spirometra mansonoides zoonotic
yes, humans can eat infected copepod or if meat uses as a poultice (wtf, just don’t do that)
the broad fish tapeworm
diphyllobothrium latum
DH of diphyllobothrium latum
SI dogs, cats, polar bears, humans… fish eating mammals
IH of diphyllobothrium latum
1IH copepod (like spirometra) 2IH freshwater fish (unlike spirometra)
is diphyllobothrium latum zoonotic?
yes
may see vitamin B12 deficiency
2 types of pseudophyllidean tapeworms discussed
spirometra mansonoides
diphyllobothrium latum
cyclophyllidean tapeworms discussed (true tapes)
dipylidium caninum taeniid types (taenia and echinococcus)
