Parasitology Exam 2

nematodes

known generally as roundworms, 1 million species, 25000 known species in 12 clades, found in virtually every environment, includes parasites and free-living nematodes, parasitism arose multiple times

pseudocoelom

fluid filled body cavity

cuticle

outer covering, contains inelastic collagen fibers

lateral chords

muscle fibers run longitudinally dorsally and ventrally

nematode characteristics

well developed muscled esophagus, intestine runs full length of body terminating in rectum and anus, excretory pore and unicellular glands make up excretory system

copulatory bursa

bursate nematodes used to grip females

copulatory spicules

used to dilate vulva; vary greatly among species

how do the mouth and stoma differ?

buccal capsule with teeth at base, tooth shape and capsule size/shape species specific

what do nematode eggs look like?

they are all morphologically similar

trichostrongylus

“black scour worm”, due to feces accumulation on fleece

haemonchus

abomasum of ruminants, feeds on blood and causes anemia

what is essential to keep the parasite alive?

keep the host alive

arrested development

latent inhibited or hypobiotic larvae, larvae encyst in the mucosal lining of the gastrointestinal tract and stay there

strongyloidea

larger and stouter than trichostrongylids, most pathogenic parasites affecting horses especially S.vulgaris

cyathostominosis

caused by large numbers existing at the same time and is often fatal

ancylostoma caninum

canine hookworm, feed on large quantities of blood, infection via ingestion, skin penetration, transmammary, primarily causes anemia

peracute hookworm disease

result of transmammary transmission, puppies deteriorate in second week of life, often fatally

acute hookworm disease

sudden exposure of older puppies to large number of larvae, typically good prognosis with treatment

chronic hookworm disease

occur without any signs

secondary hookworm disease

older, immunocompromised dogs, anemia, generally seen with malnutrition

cutaneous larval migrans

larvae enter skin (usually feet) and migrate, extremely itchy

parelaphostrongylus tenuis

meningeal worm or brain worm, white tailed deer are definitive hosts

slow response time, head tilt, stumbling, emaciation, weakness, walking in circles, blindness, no fear of humans, death

angiostrongylus cantonensis

larvae shed in rat feces and ingested by snail intermediate hosts, crustaceans and amphibians. Eosinophilic meningitis

rhabditiform espophagus

consisting of corpus, isthmus and bulb

halocephalobus gingivalis

only a single egg in the uterus, no males have been reported, horses, humans possibly cattle, meningoencephalomnyeitis

one of the most unique parasitic life cycle

only females are parasitic and reproduce asexually via parthenogenesis in the small intestine

ascaridia

roundworms, mouth surrounded by 3 lips, tail of male usually curved, eggs are extremely resistant and can remain in soil for years

ascaris suum

pathogenic parasite of swine, liver lesions that cause condemnation by meat inspectors, ling migration

A.lumbricoides

human ascarid, 0.8-1.2 billion people globally, stunted growth distended abdomen

parascaris univalens

predominant species, foals develop naturally acquired immunity between 6-12 months of age, can cause impaction colic

toxascaris leonina

infects dogs and cats in cooler climates, can arrest development of tissue in paratenic host

visceral larval migrans

migration through tissues

ocular larval migrans

migration to eye, retinal scarring

toxocara canis

small intestine of dogs, commonly seen in puppies, transplacental transmission, abdominal discomfort, obstruction, possible rupture

T.cati

small intestine of cats, less lethal than dogs

Baylisascarus procyonis

roundworms of raccoons

neural larval migrans

larva migrate to brain, permanent neurological damage or death, meningioencephalitis

programmed DNA elimination

in general, germline (sex cells, passed on) and somatic (tissues, not passed on) genomes are the same in multicellular organisms

a lot of invertebrates and vertebrates exhibit programmed DNA elimination

0.5-95% of germline genome is lost, 1000+ genes lost that are related to reproduction, distinct genomes in cells and nuclei

what can happen due to changes in genome

cancer and disease

dracunculus

guinea worm in humans, subcutaneous tissues of carnivores and humans, females can be up to 4 feet long, female ejects part of body from ulcer when wetted and prolapses part of uterus to expel larvae

gnathostoma spp

donut shaped ring around anterior end covered in spines, stomach walls of wild and domestic carnivores, second stage larvae ingested by copepod, intermediate host

extensive tissue migration in definitive host

form cyst in stomach wall, can be fatal if broken open into peritoneal cavity

larvae can migrate for years in human accidental hosts

physaloptera sp

stomach of carnivores, associated with vomiting and can be seen on endoscopy

thelazia spp

little harms to cattle, horses, flies as intermediate host

thelaziidae

conjunctival and lachrymal sac of domestic animals

Spirocera lupi

fibrous nodules in esophagus or stomach of canids, coprophagous beetles as intermediate hosts, vomiting, difficulty swallowing, aortic aneurysm

habronema sp

parasites of equine stomach, ingested by maggots, migrate to head of fly, switch host in warm, moist areas

causes summer sores, extremely itchy, difficult to heal wounds

dirofilaria immitis

canine heartworm- one of most deadly parasites in dogs, endemic in all parts of USA, parasitize pulmonary arteries, females 10-12 inches long, cats and ferrets can also be infected, mosquitoes intermediate host

worms may enter right side of heart in heavy infections, cause reduced blood pressure

dead worms carried into lungs and can cause arterial death

fatigue easily, cough, unthrifty

lymphatic filariasis

elephantitis, caused by wuchereria bancrofti (90%), Brugia malayi and B.timori

adults reside in lymphatic system for 6-8 years

subcutaneous filariasis

african eye worms, deer flies are vectors and intermediate hosts, can cross sclera of eye, swollen eyes

serous cavity filariasis

black flies or biting midge intermediate host, fever, fatigue, itching, abdominal pain, headache

enoplida

do not have tails and instead anus is terminal, first stage larvae have anchiostyle, a curbed solid stylet

dictophyme renale

giant kidney worm, carnivores, swine, humans, mink are primary definitive host, females can be 1 meter in length, fish and frogs are paratenic hosts

trichinella spiralis

found in domestic pig, currently very rare and infections tend to be from meat other than domestic pork, adult and larval stages occur in the single host, adults in small intestine, larvae in cysts in striated muscle

human trichinosis

undercooked pork, bear, horse, five larvae per gram of body weight is fatal

trichuris

adults only found in mammals, whip shaped with a hair like anterior end that embeds in intestinal wall, infective eggs are highly resistant and persist in environments

trichuris vulpis

canine whipworm, most symptom free, heavy infection causes intermittent diarrhea flecked with blood

T.trichura

human whipworm, most symptom free, can cause retarded growth in children, abdominal pain, rectal prolapse, diarrhea

leeches

terminal suckers for locomotion and attachment, fasten to skin, pierce skin and suck blood, enzyme hirudin acts as anticoagulent, some attach to oropharyngeal or laryngeal mucous membrane while swimming, severe bouts of coughing and choking with blood

obligate parasites

cannot complete life cycle without host

facultative parasites

can complete life cycle without host

stem parasites

attach to host stem

root parasite

attach to host root

hemiparasitic plants

remain photosynthetic to some degree

holoparasitic plants

obtains all fixed carbon from their host

haustorium

a cellular bridge between host and parasite used for nutrient transfer

annuals

go through their entire life cycle, from seed to flower, in a single season (peas, beans, zucchini)

biennials

take two years to complete their life cycle, with growth in the first and flowering in the second (onion, cabbage, parsley)

perennials

grow in their first year and flower repeatedly in subsequent years (rhubarb, asparagus, strawberries)

laureaceae

hemiparasitic stem vines can kill host plant, stunt growth and limit reproduction, act as vectors for plant diseases, used to treat jellyfish stings, cancer, birthing issues and other

hydnoraceae

root holoparasites leafless, emit feces-like odor to attract insect pollinators

comandraceae

root hemiparasites, found in north america

viscaceae

aerial stem hemiparasite of trees, berries are toxic to humans, featured in many different mythologies

krameriaceae

hemiparasitic root parasite of perennial herbs and shrubs, commonly called rattany, diarrhea remedy, dried roots ised to color wine and can be found in the south

rafflesiaceae

stem and root holoparasite of vines, no stem, leaves or roots, smell like rotting fish, rafflesia arnoldii have the largest flowers in the world, 3 ft across and 15 lbs, southeast asia and considered a delicacy in thailand

cynomoriaceae

root holoparasite often found in saline habitats, attracts flies with sweet scent used in herbal medicines, contraceptive, toothpaste, high blood pressure, vomiting, venereal disease and more

cytinaceae

root holoparasite of shrubs and trees, lacks roots and leaves reduced to scales

apondanthaceae

stem and root holoparasite of legumes, endoparasite- lives inside its host except to flower

mistrastemonaceae

holoparasitic root endoparasite of beech, chestnut and oak trees, produce witches brooms, a mass of shoots and may also form fairy rings, observed only during winter, pollinated by social wasps

lennoaceae

succulent root holoparasite

convulvlaceae

over 150 species, temprate and tropical climates globally, annual vining stem parasite, can be holo or hemiparasitic, many different hosts, including agriculturally important plants such as alfalfa, potatoes and clover, moderate to severe reduction in plant growth, loss of vigor and death, makes host plant more susceptible to disease and pests

cymothoa exigua

tongue eating louse, females attach to tongue of fish, severs blood vessels, feeds on blood

tongue necrosis and falls off

replaces tongue- only instance of a parasite replacing a host organ

epicaridea

parasites of crustaceans, can be ecto or endoparasites, some cause bulges on carapace

cnidocytes

aquatic organisms with specialized stinging cells

polypodium hydriforme

found in oocysts of sturgeon and paddlefish, nutrients from yolk of oocyst for free living stage-released during spawning

myxoza

obligate parasites, contains smallest organisms known-average size 10-20 microns, fish intermediate host, annelid or brozoa definitive host, do not cause disease in natural host, infection may last a lifetime, introduced to fisheries and cause disease

tetracapsuloides bryosalmonae

causes parasitic disease in salmon, up to 90% mortality

glochidium

larval stages that parasitize fish gills

cancellaria cooperii

a snail that feeds on the blood of rays

eulimidae snails

feed on fluids of brittle stars, seas stars, sea cucumbers and sea urchins

candiru

vampire fish, catfish that feed on the blood of larger fish, most are small, native to amazon basin, various historical accounts of fish attacking humans or going up urethra, accuracy questionable

simenchelys parasitica

snubnosed eel

deep sea fish- up to nearly 6000 ft, burrow in and feed on larger fish

aspidontus taeniatus

false cleanerfish, mimics cleaner wrasse, feeds on fins of fish

isistius brasiliensis

cookiecutter shark, warm oceanic water near islands, live in deep ocean and migrate vertically at night to feed, glowing belly attracts hosts, attaches, spins and cuts out circular piece of flesh

lamprey

jawless fish, feed on blood of other fish, coastal and freshwater of temperate regions

buphagus-oxpeckers

endemic to sub-saharan africa, perch on large mammals: zebra, buffalo, cattle, hippos, rhinos, giraffes

feed on ticks, botfly larvae, blood, earwax and dandruff

open new wounds to feed on blood

geospiza septentrionalis

vampire ground finch native to galapagos islands, drink blood of other birds during dry season when food is scarce

nazca and blue footed boobies peck until blood is drawn and feed, mimics removal of ectoparasites

largest and most pointed beaks of ground finches

brood parasites

rely on other species to raise their young

cuculidae

cuckoos, two inner toes point forward, outer two backwards, nearly 60 species are obligate brood parasites, egg shells thicker and stronger to resist damage, egg hatches earlier and chick kicks out other eggs/young

molothrus

cowbirds, six species in south, central and north america, obligate brood parasites, destroy rest of eggs in nest if host destroys cowbird egg

vampire bats

common, hairy-legged, and white winged, central and south america, front teeth specialized for cutting, can walk, jump, and run on land unlike other bats

only species of mammal that feeds exclusively on blood

detect infrared radiation to locate blood in hosts, hunt only when dark

rest in colonies in caves, hollow trees, can consume half of body weight in a single feeding due to rapid digestion

vector born diseases and humans

17% of all infectious disease and 700,000 deaths annually