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Flashcards in protozoa Deck (83):
1

Parasites are divided to

1. Protozoa
2. Helminthes

2

Helminthes are divided to

1. Nematodes (roundworms)
2. Cestodes (tapeworms)
3. Trematodes (flukes)

3

Protozoa infections are divided to

1. GI infections
2. CNS infections
3. Hematologic infections
4. other infections (visceral infections and STD)

4

Protozoa GI infections - bugs and diseases

1. Giardia lamblia - giardiasis
2. Entamoeba histolytica - amebiasis
3. Cryptosporidium - diarrhea

5

Giardia lamblia - disease and symptoms

Giardiasis: 1. bloating 2. flatulence
3. foul smelling, fatty diarrhea

6

Giardiasis is often seen in

campers/hikers

7

Giardia lamblia - transmission

cysts in water

8

Giardia lamblia - diagnosis

multinucleated trophozoites or cysts in stool

9

trophozoite?

a growing stage in the life cycle of some sporozoan parasites, when they are absorbing nutrients from the host. (pathogenic state)

10

Giardiasis - treatment

metronidazole

11

Entamoeba histolytica - disease and symptoms

Amebasis: 1. bloody diarrhea (dysentery)
2. liver abscess (anchovy paste exudate)
3. RUG pain

12

amebiasis - gross appearance

flask-shaped ulcer in colon

13

Entamoeba histolytica - rout from colon to liver abscess

invades through the intestinal wall to enter to the bloodstream

14

anchovy paste exudate

Amoebic abscesses of the liver produce brownish pus, which is described as looking like "anchovy paste"

15

Entamoeba histolytica - transmission

cysts in water

16

Entamoeba histolytica infection - diagnosis

- serology and/or
- trophozoites with RBCs in the cytoplasm
or cysts with up to 4 nuclei in stool

17

Entamoeba histolytica infection - treatment

1. metronidazole
2. iodoquinol for asymptomatic cyst passers

18

Cryptosporidium - disease and symptoms

severe nonbloody diarrhea in AIDS
Mild disease (watery diarrhea) in immunocompoment

19

Cryptosporidium - transmission

oocysts in water

20

Cryptosporidium - diagnosis

oocysts on acid-fast stain

21

Cryptosporidium - treatment/prevention

prevention by filtering city water supplies
notazoxamide in immunocompetent hosts
no clear treatment for AIDS patient

22

Protozoa - CNS infection - bugs and diseases

Toxoplasma gondi - toxoplasmosis
Naegleria fowleri - rapidly fatal meningoencephalitis
Trypanosoma brucei - African sleeping disease

23

Toxoplasma gondi infection and symptoms

1. Congenital toxoplasmosis --> classic triad of chorioretinitis, hydrocephalus, intracranial calcification
2. reactivation in aids --> brain abscess

24

Toxoplasma gondi transmission

cysts in undercooked meat (MC)
oocysts in cat feces
crosses placenta

25

Toxoplasma gondi - pregnant women should

avoid cats

26

Toxoplasma gondi - diagnosis

serology
biopsy (tachyzoite)
CT/MIR ring-enhancing lesion

27

Toxoplasma gondi in AIDS - CT/MIR

ring-enhancing lesion

28

Toxoplasma gondi infection - treatment

sulfadiazine + Pyrimethamine

29

Trypanosoma brucei - subspecies

1. Trypanosoma brucei rhodesiense
2. Trypanosoma brucei gambiense

30

Trypanosoma brucei - disease and symptoms

African sleeping disease: 1. enlarged lymph nodes
2. recurring fever 3. somnolence 4. Coma

31

Mechanism of recurring fever in African sleeping disease

antigenic variation

32

African sleeping disease - transmission

Tsetse fly, a painful bit

33

African sleeping disease - diagnosis

Trypomastigote in blood smear

34

African sleeping disease - treatment

suramin for blood-borne disease
melarsoprol for CNS penetration

35

Naegleria fowleri - disease and symptoms

rapidly fatal meningoencephalitis

36

Naegleria fowleri - transmission

swiming in freshwater lakes --> enters via cribriform plate

37

Naegleria fowleri - diagnosis

amoebas in spinal fluid

38

Naegleria fowleri - treatment

amphotericin B has been effective for a few survivors

39

Protozoan hematologic infections - bugs and diseases

1. Plasmodium --> Malaria
2. Babesia --> Babesiosis

40

Protozoan hematologic infections - Babesia - disease and symptoms

Babesiosis --> fever and hemolytic anemias
high risk of severe disease with asplenia

41

Babesios - area (map)

northeastern US

42

Babesios - high risk in

asplenia

43

Babesios - tranmission

ixodes tick

44

Babesiosis - treatment

Atovaquone + azithromycin

45

Babesios - diagnosis

1. Blood smear: ring form and Maltese cross
2. PCR

46

Plasmodium - bugs

P. vivax
P. oval
P. falciparum
P. malariae

47

Malaria - general symptoms

1. fever
2. headache
3. anemia
4. splenomegaly

48

Malaria - fever according to bug

P. vivax/ovale --> 48hr cycle (tertian: fever on first day and third day, thus fever are actually 48hr apart)
P. falciparum --> severe. irregular fever pattern
P. malariae --> 72 hr cycle (quartan)

49

malaria is AKA

blackwater fever

50

other complications of malaria, beside general symptoms

occlude capillaries in brain (cerebral malaria), kidney, lung (esp with P. Falciparum)

51

Malaria - transmission

anopheles mosquito (sporozoites)

52

Briefly describe the life cycle of plasmodia parasite

sporozoites in mosquito salive enter into human blood --> sporozoites enter liver cells and multiply and differentiate --> Merozoites are release from liver cells and enter RBCs --> Multiplication and differentiation into trophozoites and gamezytes within RBCs --> RBCs rupture releasing moro trophozoites, merozoites and gametocytes --> mosquito picks up male and female gametocytes when ingesting human blood

53

Malaria - relapse vs recrudescence

Relapse occurs in P. vivax and P. ovale infection ressults from hypnozoites --> reactivation of hypnozoites in liver
Recrudescence occurs in P. malariae and P. falciparum infections and results from incomplete eradication of the parasites

54

Malaria - diagnosis

1. Blood smear: trophozoites ring within RBCs, schizont containing merozoites
2. Red granules (Schuffner stippling) through RBC cytoplasm seen with P. vivax/ovale

55

Schuffner stippling

Red granules through RBC cytoplasm seen with P. vivax/ovale

56

Malaria - treatment for every situation

1. Chloroquine (for sensitive species)
2. Mefloquine or atovaquone/proquanil (for resistant)
3. IV quinidine or artesunate (If life threatening) --> test for G6PD
4. P. vivax/ovale add primaquine for hypnozoite --> test for G6PD

57

antimalaria drugs --> test for G6PD with which drugs

1. quinidine
2. artesunate
3.primaquine

58

Protozoa visceral infections - bugs and disease

1. Trypanosoma cruzi --> Chagas disease
2. Leishmania donovani --> Visceral leishmaniasis (kala-azar), cutaneous leismaniasis

59

Leishmania donovani - disease and symptoms / aka

A. Visceral leishmaniasis (kala-azar):
1. spiking fevers
2. hepatosplenomegaly
3. pancytopenia
B. cutaneous leismaniasis: 1. Skin ulcers

60

Leishmania donovani - transmission

sandfly

61

Visceral leishmaniasis (kala-azar) - diagnosis

macrphages contating amastigotes

62

Visceral leishmaniasis (kala-azar) - treatment

amphotericin B
sodium stibogluconate

63

Trypanosoma cruzi - disease and symptoms

Chagas disease:
1. dialted cardiomyopathy with apical atrophy
2. megalcolon
3. megaesophagus

64

Trypanosoma cruzi - disease / map

Chagas disease
SOUTH AMERICA

65

Chagas disease sign

ROMANA SIGN: unilateral periorbital swelling --> characteristic of acute stage

66

Trypanosoma cruzi - Transmission

Reduviid bug (kissing bug) feces, deposited in a painless bite

67

Trypanosoma cruzi - diagnosis

Trypomastigote in blood smear

68

Trypanosoma cruzi -treatment

Benzidazole or nifurtimox

69

Protozoa sexual transmitted infections - bugs and disease

Trichomonas vaginalis --> vaginitis

70

Trichomonas vaginalis - disease and symptoms

vaginitis:
foul-smelling, greenish discharge, itching and burning

71

bacterial vaginosis vs protozoal vaginitis according to symptoms

vaginitis: foul-smelling, greenish discharge, itching and burning
Bcterial vaginosis: gray vaginal discharge with fishy smell, nonpainful

72

Trichomonas vaginalis - transmission

sexual

73

Trichomonas vaginalis - outside human form

cannot exits outside human because it cannot form cysts

74

Trichomonas vaginalis - diagnosis

trophozoites (motile) on wet mount
strawberry cervix

75

Trichomonas vaginalis - treatment

Metronidazole for patient and partner (prophylaxis)

76

treatment for all protozoal infections (except malaria)

Giardiasis --> Metronidazole
amebiasis --> metronidazole, iodoquinol for asymptomatic cyst passers
cryptosporidium --> prevention by filtering city water supplies, nitazoxanide in immunocompetent, no clear treatment for aids
Toxoplasma gondi --> Sulfadiazine+pyrimethamine
Naegleria fowleri --> Amphotericin B
Trypanosoma brucei --> Suramin for blood-borne disease or melarsoprol for CNS penetration
Babesia --> atovaquone + azithromycin
Tripanosoma cruzi --> Benzidazole or nifurtimox
Leishmania donovavi --> amphotericin sodium stibogluconate
trichomonas vaginalis --> Metronidazole for patient and partner (prophylaxis)

77

Malaria - treatment for every situation

1. Chloroquine (for sensitive species)
2. Mefloquine or atovaquone/proquanil (for resistant)
3. IV quinidine or artesunate (If life threatening) --> test for G6PD
4. P. vivax/ovale add primaquine for hypnozoite --> test for G6PD

78

protozoa infection in asplenia

Babesia

79

Chloroquine - mechanism of action

Blocks detoxification of heme into hemozoin --> Heme accumulates and is toxic to plasmodia (block polymerase)

80

Chloroquine - clinical use

plasmodium species other than P. falciparum (resistance)

81

Chloroquine - P. falciparum (why)

resistance -->membrane pump that decreases intracellular concentration in drugs

82

P. falciparum - treatment

artemether/lumefantrine or atovaquone/proquanil

83

Chloroquine - toxicity

1. Retinopathy
2. Pruritus (esp in dark-skinned individuals)