Intro to Eukaryotic Pathogens: Part 1 Protozoa-Steinauer Flashcards
What are the 3 types of eukaryotic microbes? Describe them.
- Protozoa-Unicellular.
- Helminths (worms)-Flatworms (trematodes/flukes and cestodes/tapeworms); Roundworms (nematodes)
- Fungi- Cell wall made of chitin. Singe-cell (yeast) or multicellular (molds)
What microbes are “parasites”?
Protozoa and Helminths make up the “parasites.”
•Neglected tropical disease: infect the “bottom billion”
•Found in tropical areas because they are warm and moist.
•Adds to the poverty cycle.
What is the basic anatomy of protozoa?
Unicellular.
Some have more than one nucleus.
•Micronucleus and macronucleus.
•Multiple nuclei in cyst stage (important for identification)
Morphological variation through life cycle.
•Environmental vs. tissue forms.
Medically important protozoa: Intestinal Protozoa.
General info and life cycle.
Typically water born or food born. Fecal contamination from animals or humans, infecting the water or food w/ cysts. 1. Intestinal amebas oEntamoeba histolytica oTypically asymptomatic oInvasive •Amoebic dysentery •Liver abscess •Brain abscess oCosmopolitan •1-2% people in U.S. infected oTypical patient: traveler to developing country oLife cycle: Trophozoite (“troph) lives in colon, is passed out of the body and becomes a cyst with 4 nuclei in the environment.
Which Intestinal Protozoa is described as: Most frequently diagnosed intestinal parasitic disease in U.S.
oWatery, “greasy”, foul-smelling diarrhea, abdominal pain, nausea. Lasts 2-6 weeks.
oHas adhesive disc to adhere to mucosa.
oWildlife important reservoir from stream.
oTypical patient: Hiker/camper/traveler
Giardia lamblia
Which Intestinal Protozoan (intestinal coccidia) is described as: Cattle important reservoir •Deer, dogs and cats, others •Not as common as giardia. •Acute intestinal illness oDiarrhea with large fluid loss o1-2 weeks •Immunocompromised = chronic
Cryptosporidium parvum and C. hominis
Which Intestinal Protozoan (intestinal coccidia) is described as: 2013 outbreak 631 cases, 25 states
•Watery diarrhea
oIntermittent and lasts several weeks or months
•HIV-Like Cryptosporidium
Cyclospora
What stain is used for both types of coccidian?
acid fast stain
What type of medically important protozoa is described as: No cyst stage. Only get thru direct contact, not from environment.
•Most common non-viral STD worldwide
•Has flagella and undulating membrane.
•Symptoms:
50-70% Women asymptomatic, men mostly asymptomatic
Itching, burning with urination, foul greenish discharge
Miscarriage, preterm delivery
Predisposes women to infection with other viruses
Trichomonas vaginalis.
Has a virus called trichomonasvirus that is responsible for those pathogenic patients
What are some species of vector borne blood and tissue parasites?
Plasmodium species (malaria) oPlasmodium falciparum oPlasmodium knowlesi oPlasmodium vivax oPlasmodium ovale
What is the life cycle of vector borne blood and tissue parasites?
- Mosquito vector (anopheles)
* Injects sporozoites into human that migrate to liver → turns into merozoites → RBC → trophozoite.
What are the 2 types of infections with malaria?
Uncomplicated: Acute febrile illness
•Cycles of fever: Paroxysm
•Cold and chills then high fever then break
Complicated
•Cerebral malaria: seizures, coma, multiorgan system failure.
- Present in southern US
- 30-40% of affected pts will develop cardiomyopathy, digestive megasyndromes or both
- 1 in 29,000 blood donors in US positive
- Acute is within 1 month of bite
- Followed by chronic intermediate stage which is asymptomatic
- 30% of pts go to chronic stage
- Spread by bite from Rejuviid bug
Trypanosomiasis aka Chagas Disease in America
- Present in Africa
- 10,000 cases/year
- Un-treated cases → encephalitis and death
- No amastigote or intracellular stage
- Spread by bite from Glossina or Tutsy fly
Trypanosomiasis aka African Sleeping Sickness in Africa
- No trypomastigote, only amastigote
* Spread by bite from Sandfly Phlebotomus
Leishmaniasis
