Protozoa and Worms Flashcards Preview

MS2 - Infectious Disease > Protozoa and Worms > Flashcards

Flashcards in Protozoa and Worms Deck (22)
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1
Q

What are the three groups of protozoans?

A
  • Amebae: single-celled organisms
  • Flagellates: distinguished by flagellum
  • Coccidians: have structures that resemble cocci
2
Q

What are the three groups of helminths?

A
  • Trematodes: Schistosoma
  • Nematodes: Ascaris, Strongyloides, Ancylostoma, Necator, Enterobius, Trichinella, Wuchereria
  • Cestodes: Taenia, Diphyllobothirum, and Echinococcus
3
Q

Visceral Leishmaniasis will present with ________________ in the cytoplasm of macrophages.

A

amastigotes

4
Q

The ____________ form of Leishmania is transmittable.

A

promastigote

5
Q

Describe the forms of amastigote, promastigote, epimastigote, and trypomastigote.

A
  • Amastigote: small, circular, tiny flagellum
  • Promastigote: elongated, flagellum present on the tip of organism
  • Epimastigote: elongated, flagellum coming from middle of organism
  • Trypomastigote: elongated, flagellum comes from opposite end of organism as the tapered tip
6
Q

Sketchy notably omitted one sign from Chagas disease: ___________.

A

Romaña’s sign –periorbital edema

7
Q

What histologic sample is characteristic of E. histolycia?

A

RBCs within trophozoites (like the red cups in the trophozoite puddle)

8
Q

Trichomonas has multiple ___________ and does not make _____________.

A

flagella; cysts

9
Q

_____________ staining can reveal Giardia lamblia.

A

Trichrome

10
Q

______________ are characteristic of amastigotes.

A

The “pair of dots” sign

11
Q

Cyclospora is often confused with Cryptosporidium because both stain acid-fast. How are they different?

A

Cyclospora is larger

12
Q

How can you differentiate schizonts from gametocytes?

A

Schizonts are round cells with many round dots inside. Gametocytes are longer and slender.

13
Q

A patient presents with myalgia after making sausage. What other symptoms might he have?

A

Conjunctivitis and vomiting (like Mr. Porky with the red glasses and green drool)

14
Q

What shape is typical of the Enterobius vermicularis egg?

A

Flat on one side and curved on the other

15
Q

What nematodes have a pulmonary phase?

A
  • Strongyloides stercoralis

* Ascaris lumbricoides

16
Q

Where can the cysts of Taenia travel in cysticercosis?

A

Anywhere in the body – skin, eye, brain

17
Q

______________ can look a lot like Leishmaniasis.

A

The leishmanial form of Trypanosoma cruzi (which produces facial edema, lymphadenopathy, hepatosplenomegaly, and fever)

18
Q

What would you see in a non-fresh sample of E. histolytica stool?

A

Only cysts –the trophozoite form will break

19
Q

What two histologic presentations may be seen in Toxoplasma samples?

A
  • Pseudocysts inside macrophages

* Trohpozoites (banana-shaped)

20
Q

What sizes are Cryptospora and Cyclospora?

A
  • Crypto: 4 - 6 um

* Cyclo: 8 - 10 um

21
Q

Which intestinal nematode is big enough to be confused with earthworms?

A

Ascaris lumbricoides

22
Q

What anatomic sign distinguishes A. lumbricoides from earthworms?

A

Ascaris has longitudinal muscles