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64 Cards in this Set
- Front
- Back
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What does Phylum Apicomplexa consist of?
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The intestinal coccidia
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what are the 4 species of intestinal coccidia?
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1. Blastocystis hominis
2. Isospora belli 3. Cryptosporidium parvum 4. Cyclospora cayetanensis |
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what are general characteristics of coccidia?
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-used to be sporozoa
-have a sexual stage in the life cycle - oocysts -most sever inf. in immunocomp. |
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How big is the blastocystis hominis cyst?
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usually about 10u, can range from 5-32 though.
-Has three sporocysts surrounding surrounding central pallor |
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What is the significance of Blastocystis hominis?
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Commensal in 10-16% of people, but only causes diarrhea if there are >5 per field
-Normal to find in a specimen. |
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What sets B. hominis apart from the other 3 coccidia?
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It's the only one with a cyst; the other three are oocysts.
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What is the morphology of Isospora belli?
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-Oocyst that's 25-35 x 10-15u
-has 1-2 sporocysts -may stain acid fast |
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Where is Isospora belli significant?
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-Endemic in brazil, Columbia and Chile.
-Asymptomatic, may cause diarrh. -Causes dysentary in immunocomp. |
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what is the most significant of the coccidia?
What does it cause? |
Milwaukee's very own claim to fame, Cryptosporidium parvum
Causes: Cryptosporidiosis |
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Where is Cryptosporidium found?
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Worldwide in drinking H2O and swimming pools - oocysts resist chlorine.
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What are the hosts of Crypto parvum?
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Humans and other animals
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What is the morphology of cryptospordium?
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IT'S TINY! 4-6u oocyst
Have to use acid fast stain to be able to see it - that's why it took forever to identify in 1993 outbreak. |
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What features are seen in the oocyst?
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an Attachment organ, up to 4 sporozoites.
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What are symptoms of Cryptosporidiosis, seen in three levels of the infection?
-Mild -Acute -Chronic |
-Mild inf: flu-like symp.
-Acute inf: frothy, explosive diarrhea -Chronic inf. may disseminate to other organs w/ 50% death rate. |
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What 2 bases is Cryptosporidium diagnosed on?
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1. Morphological
2. Immunological |
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What two methods are used for morphological diagnosis of Cryptosporidium?
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1. Sheather's sugar flotation
2. Modified acid fast stain |
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why are the two methods used?
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Sheathers - concentrates the diarrhea, not ethyl b/c the oocyst is too light.
Mod AFstain so you can see it. |
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what conditions should you work under to identify cryptosporidium?
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Biological safety cabinet!!!
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What 2 medicines are used to treat cryptosporidium?
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Paramomycin
Spiramycin |
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How is Cryptosporidium prevented?
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1. H2O filtration
2. Good hygiene |
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What is cyclospora cayetanensis similar to, but how is it different?
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Similar to Cryptosporidium, but bigger. 8-10u
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Where is Cyclospora cayetanensis found and transmitted?
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Found in Warm/moist climates
Waterborne - likes storage tanks Guatamala rasberries lettuce and basil |
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What are the hosts of Cyclospora cayetanensis?
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Humans and maybe cattle
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How is Cyclospora identified and diagnosed? what symptoms does i cause?
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Very similar to Cryptosporidium for all, except bigger. Acid fast stain.
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How is Cyclospora cayetanensis treated?
How is it prevented? |
Trimethoprim
Sulfamethoxazole Bactrim is them put together To prevent: Avoid contaminated water and wash your berries |
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What organism comprises the Tissue coccidia?
What subphylum is this again? |
Subphylum Apicomplexa
Toxoplasma gondii |
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what disease does Toxoplasma gondii cause?
Where is it found? |
Toxoplasmosis
Worldwide |
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What are the definitive hosts of T. gondii? Why?
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Domestic or wild cats - they house the mature parasite
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What are the intermediate hosts of T. gondii? Why?
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Humans, rodents, cattle, others
They house the larval or sexually immature parasites but are necessary to lifecyle. |
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What testing is most important for diagnosing Toxoplasmosis?
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Serological
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What kind of parasite is seen for morphologically identifying Toxoplasma?
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Tachyzoite - 3-6u
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What type of parasite is Toxoplasma to humans?
What type of specimen is it seen in? |
Obligate intracellular parasite.
Only can see in a biopsy or exudate from tissue. |
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What are 2 ways Toxoplasmosis can be transmitted to humans?
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1. from Oocysts in cat feces
2. From Bradyzoites in raw meat -Humans ingest them and macrophages phagocytize. |
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What's an important and concerning happening in the life cycle of toxoplasma?
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Tachyzoites in blood can cross the placenta and enter the CNS of a fetus, causing congenital infection.
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what are 3 types of Toxoplasma that humans can have?
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1. Acquired toxoplasmosis
2. Congenital 3. Recrudescent |
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what symptoms are seen in acquired toxoplasmosis?
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Mild, flu-like, might not know.
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What symptoms of acquired toxoplasmosis are seen in IMMUNOCOMPROMISED?
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Much more severe:
-Paralysis -Convulsions -Pneumonitis -Hepatitis -Myocarditis |
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What is the most severe form of toxoplasmosis?
What tissues are affected? |
Congenital
CNS: mental retardation/seizures Eyes: blindness Blueberry muffin petechiae on forehead. |
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What is recrudesent toxoplasmosis?
What tissue is affected? |
Infection that arises though the patient had it years earlier
Flares when immunity is compromised. Encephalitis |
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How is toxoplasmosis diagnosed?
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Microscopic - tissue biopsy in histology lab
Serological |
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What 4 serological tests are used for diagnosing toxoplasmosis?
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1. Indirect flouresc. Ab
2. Elisa 3. Torch panels 4. Ophthalmology exam |
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What is a TORCH panel?
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TO = toxoplasma
R = Rubella C = cytomegalovirus H = herpes All have smlar symptoms, so tests for them all. |
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How is toxoplasmosis treated?
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Pyramethamin and SUlfandiazine, but you don't really need to know this Keren.
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How do you prevent Toxoplasmosis?
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Cook meat well
Don't go near cat poop |
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What phylum of Protozoa is not very well understood and has 5 genera you don't need to memorize?
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Phylum Microspora
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Who are Microsporidian infections seen in usually?
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Immunocompromised, rare otherwise.
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Who are usual hosts of microspora?
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Humans, insects, animals
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What is the morphology of Microscpora?
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Small; 1-4u, seen with electron micrograph.
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What 5 diseases do Microspora cause?
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1. Enteritis, cholecystitis
2. Keratitis 3. Nephritis 4. Hepatitis, peritonitis 5. Sinusitis, pneumonitis |
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What is cholecystitis?
Keratitis? Conjunctivitis? |
Inflammation of the gallbladder. Keratitis = corneal inflamm.
Conjunct = around the eye |
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How is Microsporan infection diagnosed?
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-Acid fast stain (partially AF)
-Electron microscopy is best |
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What are the 4 Acid fast protozoa in Phylum apicomplexa and Microspora then?
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-Cryptosporidium
-Cyclospora -Isospora -Microspora |
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Changing pace now..
What subphylum comprises Atrial Amoeba? |
Subphylum Sarcodina (amoeba)
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What 2 species are in subphylum Sarcodina?
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1. Naegleria fowleri
2. Acanthamoeba |
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Where is Naegleria fowleri primarily found?
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In lake bottoms in warm places like Florida.
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How do you get Naegleria fowleri?
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by diving to lake bottoms
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What type of life cycle does N. fowleri have?
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Trophozoites live in water
Get in nasal pssgs of humans Penetrate cribiform plate Enter brain, produce enzymes, turn brain to jelly. |
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What disease does Naegleria fowleri cause?
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Primary amoebic meningoencephalitis
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What are the symptoms of prim. amoebic meningoencephalitis?
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-Blocked nose
-Severe frontal headache -Nausea, fever -Death in 4-5 days Boy in florida got it... sad |
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How is N. fowleri diagnosed?
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By finding trophs about 10-20u in spinal fluid CSF, along w/ RBCs and WBCs
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How is N. fowleri encephalitis treated and prevented?
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Amphotericin B
Don't swim in Florida |
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What is a very similar organism to N. fowleri?
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Acanthamoeba - caused corneal infection in bball player cuz he didn't wash his contacts gross
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What disease does Acanthamoeba commonly cause?
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Keratitis
Meningoencephalitis |
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How is Acanthamoebiasis diagnosed?
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Immunoflourescent Ab
Morphology - see an ameboid w/ a vacuole. |
