13. cestodes Flashcards
lifecycle of cestodes
tapeworms
general characteristics of cestodes
No gut. Absorb food through surface.
Hermaphrodite - both sex organs in each proglottid (segment).
Almost all require at least 2 hosts to complete life cycle
tapeworm
tapeworms hold onto host with
scolex
tapeworm chains are also called
strobila- independent pregressively maturing reproductive unit
what organ is missing in tape worm
no digestion or feeding
absorb nurtients through skin
gravid proglottid
oldest segment of tapeworm hold eggs
mature proglottid
adult section of tapeworm that has all the things needed for reproduction
oncosphere
egg of tapeworm
First stage larva, infective for first (or only) intermediate host
Consists of an embryo (hexacanth - 6 hooks) surrounded by two embryonic membranes
what do cyclophyllidea look like?
four radial muscular suckers on scolex
rostellum- retractable hooks
longer then wide
genital pore on lateral side
no opening to release eggs
tapeworm
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Cyclophyllidea- tapeworm
four radial suckers
rostellum with retractable hooks
lateral genital pore
no opening to release egg
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Taenia saginate DH and IH are
human
cattle
tapeworm
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Taenia solium infect
DH- human
IH- pig
tapeworm
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Taenia solium cause
cysts formation throughout muscle and brain
tapeworm of pigs to humans
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
lifecycle of Taenia solium
egg or gravid proglottids ingested by pig
forms cyst in tissue
human eats infected meat
tapeworm grows in small intestine
pig tapeworm
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Echinococcus granulosus infect
dogs
small tapeworm (4-5 segments)
scolex with rostellum and 4 suckers
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
lifecycle of Echinococcus granulosus
embyonated egg in dog poop
oncosphere hatches and forms hydatid cyst in lungs and liver
form protoscolex form cyst
dog ingest protoscolex
attach to dog intestine
grow into adult and make eggs
DH- dog
IH- sheep
IH- human- attack liver and lungs
Family taeniidae
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
hydatid disease
caused by echinoccosis(tapeworm)
larval stage
E. granulosus- cysts grow but don’t infiltrate
E. multilocularis- alveolar echinococcis- cysts grow and infltrate surrounding tissue- can be fatal
E. vogeli- polycyctsic
E. oligarthrus- extremely rare
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
hydatid cyst have
caused by Echinococcus tape worm
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
protoscolices found in hydatid cyst
hydatid sane
can be invaginated, evaginate
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Anoplocephala perfoliata infect
horses and donkeys
adults can be pathogenic
2 inches long
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
life cycle of anoplocephalidae
host eats mite with cysticercoid
develop into adult tape worm in intestine
mature gravid proglottids are shed and oncosphere eggs are released
mites eats oncosphere egg
oncosphere- cysticercoid inside mite
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
tapeworms of horses
Anoplocephala perfoliata
Anoplocephala magna, Paranoplocephala
mamillana (aka Anoplocephaloides mamillana)
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Anoplocephala perfoliata are found in the
cecum and in the ileum clustered near the
iliocecal valve of horses
Adults can be pathogenic, causing ulceration and associated inflammation, leading to serious, persistent diarrhea
tapeworm of horses
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Dipylidium caninum infect
dog tapeworm
spread by fleas and biting lice
double-pored
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
— is a double pored dog tapeworm
Dipylidium caninum
spread by fleas and biting lice
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
life cycle of dipylidium caninum
flea eat larva
fleas mature- oncosphere- cysticercoid
flea bites dog
grows to adult in small intestine
shed eggs
double pored dog tapeworm
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Anoplocephala magna, Paranoplocephala
mamillana are found in — and cause
tapeworm of horses
small intestine
usually non-pathogenic
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Hynebolepis nana lifecycle
can be spread by autoinfection- eggs hatch in intestine and complete life cycle and reinfect host without need for intermediate host
can infect humans and mice
IH- flour beetle
not pathogenic- but disturbing
tapeworm
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Mesocestoididae life cycle
egg shed in gravid proglottids in feces
IH host unkown (arthropod?) eat egg(oncosphere)
second IH- to form tetrathyridium- asexual reproduction (mouse, frog)
dog or cat or human eat second IH
adult form in small intestine
tapeworm
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Davaineidae proglottina infect
chicken and pigeons
tapeworm
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Raillietine echinobothrida infect
chicken and turkeys
tapeworm
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
lifecycle of Davainae proglottina
egg from chicken or pigeon
eaten by IH (slug or snail)
oncosphere- cysticercoid
DH eat infected IH
parasite grows in small intestine
tapeworm
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
lifecycle of Raillietine echinobothrida
egg from chicken or turkey
eaten by IH (slug or snail)
oncosphere- cysticercoid
DH eat infected IH
parasite grows in small intestine
tapeworm
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
pseudophyllidae look like
scolex with two shallow longitudinal grooves- bothria
no hooks
segments have uterine pore for release of eggs
terminal segments are senile rather then gravid
eggs have a shell
require as least 2 IH
tapeworm
Pseudophyllidea- Diphyllobothrium, spirometra
— form gravid terminal segments
— form senile terminal segments
cyclophyllidea
pseudophyllidea
tapeworms
life cycle of Diphyllobothrium latum
aquatic stage:
operculate egg
coracidium
1st IH- copepod→procercoid
2nd IH →plerocercoid
3rd/ PH
DH eat IH or PH
tapeworm
Pseudophyllidea- Diphyllobothrium, spirometra
Spirometra mansonoides infect
dogs, cats, wild carnivores and pigs
humans can be 2nd IH - cause eye issues
tapeworm
Pseudophyllidea- Diphyllobothrium, spirometra
Diphyllobothrium latum infect
dog, cat, wild carnivore and humans
tapeworm
Pseudophyllidea- Diphyllobothrium, spirometra
spirometra mansonoides cause — in human
sparganosis
eye issue- swelling
humans act as 2nd IH
tapeworm
Pseudophyllidea- Diphyllobothrium, spirometra
Pseudophyllidea- Diphyllobothrium, spirometra
Cyclophyllidea- taeniidae, anoplocephalidae, dilepididae, hymenolopododae, mesocestoididae, Davaineidae
Adult cestodes (tapeworms) reside in the small intestine of definitive
hosts, with — found in or near host feces.
eggs and gravid segments
— are found in extraintestinal tissues in intermediate (and sometimes definitive) hosts and can cause severe pathogenesis.
Larval tapeworms
With a few exceptions, — are not particularly pathogenic.
adult tapeworms
— are hermaphroditic.
Cestodes(tapeworms)
Cestodes have no organs of —; nutrients are absorbed through the surface of the worm.
feeding and digestion
— cestode segments have no opening for release of eggs
and therefore produce gravid segments; — cestode
segments do release eggs and produce senile (empty) segments.
Cyclophyllidean
pseudophyllidean
— tapeworms have aquatic stages in their life cycles.
Pseudophyllidean
acanthocephalans look
thorn head
seperate sexus
no gut
cement gland in male- seals female vagina after sex
Acanthocpehalans: macracanthorhynchus, oncicola
acanthocephalans
Acanthocpehalans: macracanthorhynchus, oncicola
M. hirudinaceus infect
intestine of pigs, can infect dogs and other mammals
IH: dung beetles
can be pathogenic
no longer common in USA because of concrete floors
Acanthocpehalans: macracanthorhynchus, oncicola
— are the IH of Macracathorhynchus hirudinaceus
dung, may and water beetles
DH: pigs, can infect dogs and other mammals
Acanthocpehalans: macracanthorhynchus, oncicola
Oncicola canis lifecycle
not really known
DH- rare in dogs and cats
IH- unkown- dung beetle?
Possible paratenic hosts (lizards?, birds?, etc.)
Acanthocpehalans: macracanthorhynchus, oncicola
M. hirudinaceus egg
fully developed larve in egg
generic acanthocephalan egg
Acanthocpehalans: macracanthorhynchus, oncicola
how to diagnosis M. hirudinaceus
thick brown shelled ovoid egg
adults with spiny nose, no gut or circulatory system
Acanthocpehalans: macracanthorhynchus, oncicola
how does M. hirudinaceus attach to host
uses hooks
no mouth
cause necrosis and flattened villi at site of attachment
Acanthocpehalans: macracanthorhynchus, oncicola
symptoms of M. hirudinaceus
Can be asymptomatic
Ulceration and granuloma formation at site of infection
Acute
– Peritonitis
- mechanical disruption of intestine wall
Chronic
– Related to worm burden
– Competition for nutrients
– Diarrhea, wasting, failure to thrive
spiny nose
Acanthocpehalans: macracanthorhynchus, oncicola
