Parasitic Diseases- Protozoa Flashcards
what are the 4 classifications of protozoa?
- mastigophora: flagellates
- sarcodina: amoebae
- ciliophora: ciliates
- apicomplexa: apicomplexans
describe mastigophora
have a long flagella for movement
describe sarcodina (3)
only a few parasites in this class, water-borne and cause neurologic symptoms
describe ciliophora, give a special case
have cilia for movement, rumen protozoa are ciliates, but NOT parasites, symbiotic
describe apicomplexa
angular vertex structure to help parasite burrow into cells and tissue
give 2 common charaterisitics of all protozoans
- unicellular
2. have 2 life cycle phases: cyst/oocyst and trophozoite
describe the cyst/oocyst life cycle phase of protozoans (3)
- resistance phase to protect from dehydration/in the environment
- infective to new hosts
- covered by a protecting wall
describe the trophozoite phase of protozoans
- vegetative form, inside the host
- parasite replicates by sexual or asexual methods and feeds on the host
- has the ability to move around in host body
describe the typical fecal-oral life cycle of protozoans in terms of cyst/oocyst and trophozite
- cysts are passed in feces, resistant, and infective
- once in new host, excystation occurs and now the trophozoite is feeding, motile, and replicating
- trophozoite undergoes encystment and is passed in feces as cycle starts again
what classification of protozoan is Giardia spp.?
a flegellate
where is the protozoan Giardia spp. found?
in the small intestine of a wide range of mammalian hosts
where does Giardia spp. attach in the host? why can this be a problem for the protozoan?
to the ventral surface on intestinal lining; the epithelial cells lining intestinal villi are continually being shed so the Giardia trophozoites have to relocate frequently
when attached to the intestinal lining, what do Giardia trophozoites do? (2)
- asexual mitosis to replicate
2. mainly cause diarrhea and steatorrhea (yellow, fatty feces) due to eating the intestinal lining
what does a heavy infection of Giardia spp. do to the host?
flattens intestinal mucosa, which causes decreased production of digestive enzymes, malabsorption, of nutrients, and weight loss
what type of life cycle does Giardia spp. have?
direct life cycle
describe the direct life cycle of Giardia spp.
trophozoites live in the villi of the small intestine, where they undergo encystation, then the cysts pass in feces, where they are ingested by the host and undergo excystation to become trophozoites in the villi again
what is the one health concern for Giardia spp.? how avoid?
zoonotic!! wash your vegetables (if fertilized with manure) and treat your water!
how do you diagnose Giardia spp.?
find cysts in feces
how do you treat Giardia spp.?
kind of back door, there’s no approved drugs for treatment in dogs and cats in the USA… but antihelmintics work pretty well
how do you control the spread of Giardia spp.? (3)
isolate infected individuals, bathe them to remove cysts, and remove feces from areas and animals to limit ingestion spread
what classification of protozoans are coccidia?
apicomplexans
what are the 2 types of coccidia?
- eimeria
2. isospora
what mess-you-up things do coccidia do and how?
acute invasion and destruction of intestinal mucosa, can get inside cells (intracellular parasites!)
what symptoms do coccidia cause?
the general, nonspecific symptoms most often seen in increased stress such as diarrhea, fever, loss of appetite, weight loss, death in extreme cases
in what 6 animals is coccidiosis and economically important disease?
- cattle
- sheep
- goats
- pigs
- poultry
- rabbits
in what 3 animals is coccidiosis less common?
- dogs
- cats
- horses
in an eimeria oocyst, or egg, how many sporocysts are there and how many sporozoites are there in those?
4 sporocysts, each with 2 sporozoites, so each oocyst can make 8 trophozite protozoans
in an iospora oocyst, or egg, how many sporocysts are there and how many sporozoites are inside that?
2 sporocyst each with 4 sporozoites, so each oocyst can also make 8 trophozoite protozoans
describe the amount of species of coccidia
multiple species with specific hosts
what kind of life cycle do coccidia have?
direct, only one host
describe the life cycle of coccidia
- sporogony, or oocysts are ingested into digestive system
- schizogony: oocysts enter intestinal cells and undergo asexual replication to be come trophozoites
- gamogony: trophozites differentiate into male (flagella) and female cells that meet and produce an oocysts which is passes in feces to be ingested and continue cycle
what does the gamogony phase of the coccidia life cycle create?
genetic variation
where is coccidiosis seen?
universally, but most commonly in young animals housed or confined in small areas contaminated with oocysts
what kind of pathogen are coccidia?
opportunistic, if pathogenic, their virulence may be influence by many stressors
describe prevention of coccidia (3)
- hygiene
- reduce stressors
- coccidiostats like monensin, althought have developed resistance to monensin
what type of protozoan is sarcocystis?
apicomplexans
what kind of life cycle does sarcocystis have?
indirect; has an intermediate host and and final host
who is the intermediate host for sarcocystis?
usually herbivores
who is the final host for sarcocystis?
carnivores, like dogs
what is the one health concern about sarcosystis? what can this cause?
can be zoonotic for strains whos final “carnivore” host is humans, this kind usually comes from pigs and can cause meat condemnation
what is the range of symptoms caused by sarcocystis in intermediate hosts and what does it depend on?
can be chronic to asymptomatic, depending on parasite load
what symptoms are observed in the final host of sarcocystis?
acute to chronic diarrhea due to intestinal growth of parasites
what are the symptoms of sarcocystis in the intermediate host dependent on?
location of cysts
when sarcocystis cysts are in the muscle of the intermediate host, what are the symptoms?
loss of tail hair, hyperexcitabilty, weakness, prostration, death
describe the 4 aspects of control of sarcocystis
- no effective treatment for muscle cysts
- prevent ingestion of prey carcasses or raw tissues by carnivores
- prevent grass and water contamination in intermediary hosts
- give anticoccidials in final hosts
describe the indirect life cycle of sarcocystis
cysts in the muscles of herbivores are ingested via meat by herbivores, cysts undergo excystation into trophozoites for sexual reproduction (micro = sperm) (macro = female) to produce more oocysts that are secreted in feces and ingested by grazing intermediary hosts and start cycle again
is sarcocystis a common diagnosis?
no, due ot its general symptoms
do the oocysts of sarcocystis contain any sporozoites?
nope, just sporocysts that have to decyst into trophozoite
what classification of protozoan is Toxoplasma gondii?
apicomplexans
what kind of life cycle does Toxoplasma gondii have?
indirect
what is the intermediate host of Toxoplasma gondii and what happens to them?
herbivores, they get the disease
what is the final host of Toxoplasma gondii?
cats
what is the one health concern for Toxoplasma gondii?
zoonotic, pregnant women no scoop litterbox
what are the symptoms of Toxoplasma gondii in young and immunocompromised animals? (7)
- intersitial pneumonia
- myocarditis
- hepatic necrosis
- meningoecephalomyelitis
- chorioetinitis
- lymphadenopathy
- myositis
what is the most common symptoms of Toxoplasma gondii when human are intermediate host?
chorioetinitis (eye inflammation)
describe the diagnosis of Toxoplasma gondii (2)
- indirect diagnosis by serologic testing
2. postmortem diagnosis via histologic, bioassay, and molecular methods
how do you treat acute toxoplasmosis?
anti-coccidial drugs (also kinda backdoor)
describe the indirect life cycle of Toxoplasma gondii
trophozoites in cat intestine produce oocysts (sexual replication) that are excreted in feces, where they sporulate into trophozoite and are ingested by herbivores who acquire the parasite, which travels trhough the body and encysts in muscles
what super scary thing can the trophozoites of Toxoplasma gondii do?
pass through the placenta and cause abortion
when testing for Toxoplasma gondii, what are the 3 dots?
- control
- IgG
- IgM
what does it mean if you get a positive result for IgM antibodies when testing to Toxoplasma gondii?
animal is going through the disease right now
what does it mean when you get a positive result for IgG antibodies when testing for Toxoplasma gondii?
animal previously had disease
what type of protozoan is Trichomonas foetus (Trichomonas)?
flagellate
in what animals is Trichomonas a problem?
cattle, esp beef
what dpes Trichomonas cause?
early fetal death and infertility (embryonic death)
is there any treatment for Trichomonas?
nope, cull the animal
where does Trichomonas live?
cattle repro tract
where in bulls is Trichomonas found?
preputal mucosa, can even infect semen
where in female cows is Trichomonas found? what does this mean (2)
os cervix, so can either infect more bulls and keep spreading or make it to the placenta and kill the fetus
how is Trichomonas transmitted?
venereally (STD for cattle)
what type of protozoan is Leishmaniosis?
flagellate
where in the body is Leishmaniosis found?
in the blood, not the intestines like most other protozoans
how is Leishmaniosis transmitted?
by sand flies
what kidn of life cycle does Leishmaniosis have?
indirect
describe the life cycle of Leishmaniosis?
a dog is infected with promastigotes, macrophages phaocytose promastigotes, and inside macrophages they multiplicate and change into amastigotes, where a mosquito can ingest during a blood meal, change to mastigotes, then macrophages inside the mosquitoes’ intestine burst and release promastigotes, and then mosquito bites a healthy dog to continue life cycle
