Intro to Eukaryotic Pathogens: Part 1 Protozoa-Steinauer

Question 1

What are the 3 types of eukaryotic microbes? Describe them.

Answer 1

1. Protozoa-Unicellular.
2. Helminths (worms)-Flatworms (trematodes/flukes and cestodes/tapeworms); Roundworms (nematodes)
3. Fungi- Cell wall made of chitin. Singe-cell (yeast) or multicellular (molds)

Question 2

What microbes are “parasites”?

Answer 2

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.

Question 3

What is the basic anatomy of protozoa?

Answer 3

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.

Question 4

Medically important protozoa: Intestinal Protozoa.

General info and life cycle.

Answer 4

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.

Question 5

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

Answer 5

Giardia lamblia

Question 6

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

Answer 6

Cryptosporidium parvum and C. hominis

Question 7

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

Answer 7

Cyclospora

Question 8

What stain is used for both types of coccidian?

Answer 8

acid fast stain

Question 9

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

Answer 9

Trichomonas vaginalis.

Has a virus called trichomonasvirus that is responsible for those pathogenic patients

Question 10

What are some species of vector borne blood and tissue parasites?

Answer 10

Plasmodium species (malaria)
oPlasmodium falciparum
oPlasmodium knowlesi
oPlasmodium vivax
oPlasmodium ovale

Question 11

What is the life cycle of vector borne blood and tissue parasites?

Answer 11

• Mosquito vector (anopheles)

* Injects sporozoites into human that migrate to liver → turns into merozoites → RBC → trophozoite.

Question 12

What are the 2 types of infections with malaria?

Answer 12

Uncomplicated: Acute febrile illness
•Cycles of fever: Paroxysm
•Cold and chills then high fever then break
Complicated
•Cerebral malaria: seizures, coma, multiorgan system failure.

Question 13

• 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

Answer 13

Trypanosomiasis aka Chagas Disease in America

Question 14

• 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

Answer 14

Trypanosomiasis aka African Sleeping Sickness in Africa

Question 15

• No trypomastigote, only amastigote

* Spread by bite from Sandfly Phlebotomus

Answer 15

Leishmaniasis

Question 16

• Infect phagocytic cells in spleen and liver
• Develops months to years after bite
• Fever weight loss, splenomegaly, anemia

Answer 16

Visceral Leishmaniasis

Question 17

• Cutaneous lesion
• Few weeks to months
• Small red papule
• Ulcers with raised hardened borders, pruritic, not painful
• Scarring
• Amastigote in skin scraping

Answer 17

Cutaneous Leishmaniasis

Question 18

• Infect phagocytic cells in soft palate and mucosal tissues like ears and nose
• Leishmania brasiliensis
• Begins as cutaneous leishmaniasis
• May progress to erode mucosal and cartilaginous tissue

Answer 18

Mucocutaneous Leishmaniasis

Question 19

•Parasite of cats
•Produces oocysts (coccidian)
•Humans can be infected through eating vegetables from a garden where cats have pooper or interacting with litter boxes
•Asymptomatic or flu-like symptoms
•More serious in pregnant women and the immunocompromised
 Most serious is woman is exposed for the first time early in pregnancy
 Symptoms are seizures, growth retardation, hydrocephalus and miscarriage

Answer 19

Toxoplasma gondii

Question 20

•Contact lens wearers, abrasion
•Disease
 Foreign body sensation, photophobia, decreased visual acuity, tearing, pain and redness
 Permanent visual impairment or blindness
•Tophozoite stage then a cyst stage which can last in tap water a long time

Answer 20

Acanthamoeba

Question 21

Trypomastigote

Answer 21

• Extracellular

* Sickle shaped

Question 22

Amastigote

Answer 22

• Intracellular

* Circular with 2 dark staining bodies