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LAST EXAMMMMMM Year I > Protozoa > Flashcards

Flashcards in Protozoa Deck (73):
1

What are protozoa

free living, single eukaryotic cells with cytoplasmic membrane and organelles that have 1 or 2 nuclei, mitochondria, food vacuoles and ER

2

what are the layers of protozoa

outer layer of cytoplasm called ectoplasm and inner layer called endoplasm

3

How do protozoa ingest human RBC

cytostome- small mouth

4

how do protozoa reproduce

asexually by replication and division
also sexually by fusion and division

5

What is the infective form of protozoa

cysts

6

what is the motile form of protozoa after ingested as cysts

trophozoite

7

What are the 5 intestinal protozoa that cause diarrhea

Entamoeba Histolytics- bloody
Giradia lamblia, Cyclospora cayteanensis- non bloody
Cryptosporidium and Isospora belli- immunocompromised

8

describe the precyst form of Entamoeba Histolytica

has aggregates of ribosomes called chromotoid bodies and food vacuoles that are extruded as cell shrinks to mature

9

What causes the blood in diarrhea from Entamoeba Histolytica

when the motile trophozoite invades intestinal mucosa

10

What suggests active infection of E histolytica

trophozoites with RBC in cytoplasm

11

What is the most sensitive and specific test for E histolytica

Ag detection assays of stool or serum

12

What wil a CAT scan or ultrasound look like of person with E histolytica

abscesses of liver sometimes

13

What does metronidazole kill

E histolytica, G lamblia, Trich vaginalis, Baceteroides fragilis, C dificile, Gardnerella vaginalis

14

What are the adverse effects of metronidazole

with alcohol causes stomach upset
metallic taste in mouth

15

What form of Giradia lamblia looks like a kite

the mature throphozoite

16

What are the signs of G lamblia infection and why?

fat in diarrhea with really bad odor
abdominal distention and cramps and gas
the trophozoite adheres to small intestine wall preventing intestinal fat absorption

17

Describe transmission of Cryptosporidium

ingested as round oocyst with 4 motile sporozoites
life cycle in intestinal epithelial cells

18

What can cryptosporidium cause in immunocompromised patients

severe, protracted diarrhea that is life-threatening

19

How do you Dx isospora and cyclospora

stool microscopy because both are acid fast!

20

What protozoa are flagellated

giardia and trich vaginalis

21

what are symptoms of trich vaginalis in women? men?

women: pruritis, burning while peeing, vaginal secretions(thin watery and malodorous)
men: asymptomatic

22

What are the free-living meningitis causing amoebas

Naegleria fowleri, Acanthamoeba and Balamuthia mandrillaris

23

What is the presentation of Naegleria fowler? how is it acquired?

swimming, organisms penetrate nasal mucosa and pass to cribioform plate
fever, HA, stiff neck, nausea and vomiting
CSF shows high neutrophils. high protein and low glucose

24

What does Acanthamoeba cause

chronic, granulomatous brain infection in immunocompromised patients
HA fever, seziures and focal neuro signs

25

What does Balamuthia mandrillaris cause

amebic encephalitis
infects immunocompetent and compromised
chronic granulmoatous skin lesions

26

What are the 4 common parasites in AIDS patients

cryptosporodium, Isospora
Pneumocystis carinii and Toxoplasma gondii

27

What is the presentation of toxoplasma gondii

fever, lymph node enlargement, HSM, pneumonia
infection of brain and meninges

28

What is the most common CNS infection in AIDS patients? presentation?

toxoplasma encephalitis
fever, HA, gait instability, weakness, sensory loss, chorioretinitis with blindness
(white yellof fluffy cotton patches in retina)

29

What does T gondii cause after crossing placenta

still birth if early on
chorioretinitis, seizures, mentral retardation, microcephaly, encephalitis

30

How do you Dx T gondii

CAT of brain showing contrast-enhacning mass
Examination of retina shows retinal inflammation
Inc Ig titers

31

What is the most common opportunistic infection in AIDS patients ? presentation?

PCP
fever, SOB nonproductive cough
b/l diffuse infiltrates

32

What would you see in someone with PCP

diffuse perihilar interstitial streaking b/l sparing the outer margins
flyer saucer fungi in silver staining

33

What are the organisms that cause malaria

Plasmodiums: falciparum, vivax, ovale, malariae and knowlesi

34

What plasmodium burst causing fever every 48 hours

ovale and vivax
"tertian malaria"

35

what plasmodium causes fever every 72 hours

P malariae
quartan malaria

36

When does P falciparum cause fevers

irregular between 36-48 hours

37

What are the thin motile forms of Plasmodia called

sporozoites

38

When plasmodium sporozoites enter liver cell what begins

pre-erythrocytic cycle because the sporpozoites rounds up to form a trophozoite that undergoes nuclear divisions forming big mass with thousands of nuclei called schizont
cytplasmic membrane forms around each nuclei making merozoites that are let out when the liver cell vursts

39

What is the exo-erythrocytic cycle

merozoites that infect another liver cell after initial exposure already happened (some left for blood)

40

what is the erythrocytic cycle of plasmodia

when merozoites enter blood cells
trophozoite shaped like a ring with nuclear diamond
RBC lysis causes fevers, chills and sweats

41

What plasmodia form dormant counterparts

vivax and ovale
they are called hypnozoites-- relapsing malaria

42

Which plasmodia have severe clinical manifestations

falciparum and knowles

43

What plasmodium is R to chloroquine

faciparum
except in parts of Central America

44

What is cerebral malaria characterized by

seizures and impaired consciousness leading to coma

45

What mutation allows resistance to P vivax and falciparum

absence of RBC membrane Ag Duffy a and b: vivax
sickle cell for falciparum

46

What phase of P vivax and oval is protected from chloroquine

when in exo-erythrocytic cycles in liver

47

What is the main Tx for the exo-erythrocytic cycles of malaria in liver

primaquine

48

what drug is used for P falciparum

quinine
artemether is the new one

49

What are common features of anti-malarials

oral
cause GI upset
cause hemolysis in those with G6PD deficiency
safe in all trimesters of pregnancy

50

What is Babesiosis and what carries it

infection like malaria from a tick that invades RBCs causing fever and hemolytic anemia

51

What is different from babesiosis and malaria besides mode transmission

babesiosis does not infect liver cells

52

what is the shape of the babesia trophozoite

X shaped tetrad of 4 merozoites

53

What are the shapes of leishmania and trypanosomas

round cell w/o flagella: amastigotes
flagellated motile forms: promastigotes, epimastigotes and trypomastigotes

54

How is leishmania transmitted

sandfly
South and central america, Africa and middle east

55

where does the sandfly infect

promastigote invades macrophages then changes to amastigote and replicates in lymph nodes, spleen, liver and bone marrow

56

What are the 3 clinical forms of leishmania

cutaneous
mucocutaneous
Visceral

57

Presentation of cutaneous leishmania

site of bite there is a skin ulcer called "oriental sore"
heals after a year leaving pale scar
invokes DTH so can use PPD like test

58

Where is diffuse cutaneous leishmania seen? presentation?

Venezuela and Ethiopia with patients that have deficient immune systems
concentration of nodular lesions near nose
no DTH because defective immune system

59

Presentation of mucocutaneous leishmania

dermal ulcer that heals
months and years later ulcers in mucous membrane arise and could cause erosion of nasal septum, palate and lips

60

Presentation of visceral leishmania

malnourished children
abdominal discomfort and distention
low grade fever, anorexia and weight loss

61

What leishmaniasis has massive splenoegaly

L donovani's

62

Is the leishmanin skin test useful during active disease

no because cell mediated immunity is deficient

63

What do you use to Tx leishmania

stibogluconate

64

What transmits AFrican sleeping sickness

tsetse fly
trypanosoma

65

what is presentation of african sleeping sickness

har red painful skin ulcer that heals in 2 weeks
systemic: fever, HA, dizzyness and lymph node swelling
goes away and returns weeks later
then drowsiness, behavioral change, difficulty walking, slurred speech, coma and death

66

What are the two forms of african sleeping sickness and pathogens

West is caused by Trypanosoma brucei gambiense: slowly progressing wasting
East is caused by T brucei rhodesiense: more severe and rapid

67

Why do the trypanosomes cause intermittent fvers

from variable surface glycoproteins that they continueally change

68

How can you Dx trypanosome infection

visualization of trypomastigoes in peripheral blood, lymph nodes, spinal fluid
rapid card agglutination for anti-T brucei gambiense Ab is available

69

How do you Tx trypanosome infection

suramin or pentamidine if CNS not involved yet
CNS involvement- use eflornithine or nifurtimox when melarsoprol

70

What is Chagas disease caused by and presentation

Trypanosoma cruzi (American)
hardened red area(chagoma) with fever, malaise and swollen lymph nodes
HEart inflammation causing tachycardia and EKG changes
CNS- meningoencephalitis
resolves in a month and enters intermediate phase

71

Describe presentation of chronic chagas disease

hear arrhythmias and dilated cardiomyopathy
megadisease of colon and esophagus

72

How do you Dx Chagas

direct examination of blood for motile trypomastigotes
Xenodiagnosis: bugs feed on patient and one month later intestinal contents of bugs examined for parasite

73

What could you get from intake of material infected with pig feces

Balantidium Coli
diarrhea
Tx with tetracycline