Micro 29 - Protozoa Flashcards Preview

DIT Microbiology > Micro 29 - Protozoa > Flashcards

Flashcards in Micro 29 - Protozoa Deck (63):
1

How is cryptosporidium spread and can we remove it from the source?

Transmitted by oocysts in water or person to person. Filtration removes oocysts from water.

2

How does one get infected with Giardia lamblia what are the symptoms?

Ingested cysts turn into trophozoites that interfere with fat absorption. It causes acute, fatty, foul-smelling diarrhea, flatulence, and abdominal bloating.

3

How is the diagnosis of Giardia lamblia made?

Pear-shaped trophozoites or cysts in stool.(O and P).

4

What is the treatment for Giardia lamblia?

Metronidazole or Tinidazole.

5

What does Entomaoeba histolytica cause?

Amebiasis causing bloody diarrhea, causing Amoebic dysentery. Can perforated colon, causing a flask-shaped ulcer with a narrow opening and submucosal ulceration. Can also cause liver abscesses causing RUQ pain.

6

How is Entamoeba histolytica spread?

Transmitted through fecal-oral route.

7

How is Entamoeba histolytica diagnosed?

Trophozoites or cysts in stool (may see ingested RBC's). (O an P).
Or serology, or stool antigen.

8

What is the treatment for Entamoeba histolytica?

Kill trophozoites with Metronidazole > Tinidazole. Kill the cysts that may remain in the intestine with Iodoquinol or paromomycin.

9

On which infections do we use Metronidazole?

"GET GAP on the Metro!"
Giardia
Entamoeba
Trichomonas
Gardnerella vaginalis
Anaerobic bacteria
Pylori (H. pylori).

10

What is the most common protozoal infection in the US?

Tichomonas vaginalis.

11

What are the symptoms of Trichomonas vaginalis and how is it spread?

"The three F's for Trichomonas vaginalis"
Foul-smelling
Flagella
Flagyl (metronidazole)

Causes vaginitis and a foul-smelling, greenish vaginal discharge. Primarily transmitted through sexual activity.

12

How is Trichomonas vaginalis diagnosed?

A wet mount of vaginal discharge, looking for trophozoites (pear shaped and move around fast in their characteristic twitching motion.)

13

What are the similarities and diferences of Trichomoniasis and bacterial vaginosis (BV)?

Both are due to increase of vaginal pH and are treated with metronidazole.

Trichomoniasis is caused by sexually transmitted protozoan while the latter is caused by overgrowth of anaerobe (Gardnerella vaginalis).

14

Why are cats so important in Toxoplasma gondii?

Cats are the only host where the protozoan can complete it's reproductive cycle.

15

How is toxoplasma gondii transmitted to humans?

Handling of cat feces or litter because of oocysts that are liberated through the cat. Or by eating cysts infected meats.

16

What does toxoplasmosis cause in the brain of AIDS patients?

Ring enhancing lesions in the brain in MRI of AIDS patients.

17

What is the classic triad that Congenital toxoplasmosis cause on the fetus?

1. Chorioreinitis
2. Hydrocephalus
3. Intracranial calcifications.

18

How is toxoplasmosis diagnosed?

Serology or biopsy (because primary CNS lymphoma can also present as ring enhancing lesion on MRO).

19

What is the treatment for toxoplasmosis?

Sulfadiazine + pyrimethamine + folinic acid.

20

What is naegleria fowleri and what does it cause and how is it transmitted?

It is a ameba that causes rapidly fatal meningoencephalitis. Transmission from swimming in freshwater lakes. Enters nose and passes through cribriform plate to brain.

21

What is the treatment for Naegleria fowleri?

Amphotericin B (offlabel use) but few people have gotten the treatment in time to survive the infection.

22

What does cryptosporidium cause in AIDS patients?

Chronic, watery diarrhea.

23

What is Trypanosomiasis and what are the 2 relevant subspecies?

It is the bacteria that causes African sleeping sickness.
It is caused by Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense.

24

How is trypanosomiasis transmitted?

Blood-borne by vector, specifically through the tsetse fly.

25

What are the symptoms of African sleeping sickness?

A bloodstream infection, it causes fever, enlarged lymph nodes and somnolence. Late stage infection involves encephalitis, coma and death.

26

How is trypanosomiasis diagnosed?

Bloodsmear, long, wispy looking organisms in the blood.

27

What is the treatment for trypanosomiasis?

Suramin for early bloodstream infection. Melarsoprol for CNS involvement.

28

What does Trypanosoma cruzi cause?

Chagas disease.

29

How is Chagas disease transmitted?

By the reduviid bug, the "kissing" bug. It is a painless bite but it defecates, and the bacteria is in the dropping. The human scratches the site of bite near the dropping and that is how it gets infected.

30

What does Chagas disease cause?

Dilated cardiomyopathy.
Megaesophagus.
Megacolon.

31

How is Chagas diagnosed?

Bloodsmear.

32

What is the treatment for Chaga disease?

Benznidazole or Nifutimox.

33

What is Leishmania donavani and what are the two mains types of clinical presentations?

An intracellular parasitic protozoan. It can cause Visceral leishmaniasis or cutaneous leishmaniasis.

34

How is Leishmania donovania transmitted?

Via the sand fly. Dogs and other animals can be the reservoir.

35

What are the clinical presentations of Visceral leishmaniasis?

Spiking fevers.
Hepatosplenomegaly.
Pancytopenia.

36

How is Visceral Leishmaniasis diagnosed?

Amastigotes inside macrophages.

37

What is the treatment for Viscerla leishmaniasis?

Liposomal amphotericin B.

38

What are the clinical presentations of Cutaneous leishmaniasis?

Ulcerating papules that are slow to heal.

39

What is the treatment for Cutaenous leishmaniasis?

Sodium stibogluconate.

40

What are the species that causes malaria?

1. P. vivax
2. P. Ovale
3. P. falciparum
4. P. malariae

41

How is malaria transmitted?

By the Anopheles mosquito.

42

What are the symptoms of malaria?

Cyclic symptoms like fever, occur when RBCs rupture and release merozoites. Also causes fever, headache, anemia and splenomegaly.

43

What species of malaria has a 48-hour cycle?

P. ovale.
P. vivax.

44

What species of malaria has a 72-hour cycle?

P. malariae.

45

Which species of malaria is the most severe?

P. falciparum (it has the longest name).

46

What are some clinical aspects of malaria caused by P. vivax and P. ovale?

It is the malaria that has a dormant infection in liver that needs to be treated with primaquine.

47

What are some clinical aspects of malaria caused by P. falciparum?

It does not have a dormant phase, it is the most severe form and the most common in Africa. It can cause sequestration of RBCs, causing occlusion of small vessels that causes mini infarcts anywhere in the body.
On blood smear, they are the only species that has a banana-shaped gametocyte.

48

How is malaria diagnosed?

By bloodsmear.

49

Describe the cycle of malaria.

1. Anopheles mosquito bites human.
2. It releases sporozoites into the blood stream, which travel into the hepatocytes, initiating the exoerythrocytic cycle.
3. The sporozoites make early schizonts inside the liver, which mature into tiny late schizonts, rupturing the hepatocytes at the end to release merozoites into the blood stream.
4. The merozoites invade the RBCs, initiating the erythrocytic cycle.
5. The merozoites mature into trophozoites (resembling diamon ring) inside the RBC, that mature into early schizont, late schizont, and at the end rupture the RBC, releasing merozoites and triggering fever and chills.

50

What is the treatment of malaria?

1. Chloroquine. (+ Primaquine if it is P. vivax or P. ovale).
2. If Chloroquine-resistant, Quinine + doxycyline, Atovaquone-proguanil, Artemether-lumefantrine, Mefloquine.

51

What is babesiosis and what organism causes it?

Protozoa infection that causes malaria-like symptoms. It is caused by Babesia microti.

52

How is babesiosis diagnosed?

Blood smear: Has "Maltese cross" in RBC as Merozoite form and Ring form in RBC as Trophozoite.

53

What are the clinical symptoms of babesiosis?

Causes feer and hemolytic anemia.

54

In which part of the USA does babesiosis occurs predominantly? And why?

Occurs mostly in northeastern USA due to the vector Ixodes tick. This vector also carries Borrelia burgdorferi and Anaplasma phagocytophilum, which are responsible for Lyme disease and anaplasmosis, respectively, making co-infections very common.

55

What is the treatment for babesisosis?

Quinine + clindamycin.

56

What stage of malaria does it look like a diamond ring?

Early trophozoite.

57

What stage of malaria does it ruptures the cell host?

Merozoite.

58

What stage of the malaria is replicating intracellularly?

Schizont.

59

What stage of malaria is the form injected from the Anopheles mosquito?

Sporozoite.

60

What form of malaria is banana-shaped?

Gametocyte of Plasmodium falciparum.

61

RFR: Ring-enhancing brain lesion in an HIV patient?

Toxoplasma gondii.

62

RFR: Treatment for Trichomonas vaginalis?

Metronidazole.

63

RFR: Most common protozoal diarrhea?

Giardia lamblia.