Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MIMM 413 > Toxoplasmosis > Flashcards

Toxoplasmosis Flashcards

1
Q

true or false: toxo is a protozoa

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

true or false: toxo is a coccidia, microsporidia

A

-false
coccidia, sporozoa, microsporidia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

true or false: toxo gondii is a food and waterborn parasite

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

toxo gondii: development of oocysts that are shed with…..

A

the defenitive host feces and contaminate the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

when was toxo gondii first described and by who

A

1908 in Tunis by Nicolle and
Manceaux in the gundi, which is an African rodent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

when was toxo gondii named

A

1909

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

true or false: several decades passed before we knew what toxo gondii di to humans

A

yeah

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

when was the standard test developed for giardia

A

1948, serological dye test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

when was the life cycle for giardia first described and why who

A

start of 1970’s by frenkel and hutchinson

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

which parasite uses 2 sets of hosts for the completion of its life cycle

A

toxo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the 2 life cycle of toxo and it infects what

A

-1. ASEXUAL CYCLE IN
“INTERMEDIATE” HOSTS
Humans, cattle, rodents, pigs,
sheep, cats, etc
(all warm-blooded vertebrates)
-2. SEXUAL CYCLE IN
“DEFINITIVE” HOSTS
Cats and other Felids
via carnivorism / predation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

which steps of toxo are in the asexual cycle

A
  1. Tachyzoites
  2. Bradyzoites in tissue cysts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

which steps of toxo are in the sexual life cycle

A
  1. Macro- and microgametes
  2. Sporozoites in oocysts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

contamination of toxo occurs mostky how

A

-oral route
-ingestion of raw or partly cooked meat like pork, lamb or venison who contain tissue cyst (bradyzoites)
-ingestion of oocyst contaminated cat feces through hand to mouth contact
-drinking water contaminated with oocysts
-transplacental infection in utero (tachyzoites)
-transplantation of an infected organ (bradyzoites in tissue cyst)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

prevalence of toxo in humans

A

-up to 60% of the human population is seropositive
-Up to 60% in Québec (especially Nunavik Inuit), Nunavut, Western Europe
-depends on food habits and contact with cats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

prevalence of toxo in animals

A
  • ~ 10% in pork
  • ~ 40% in sheep/lamb
  • 20-63% in goats
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

true or false: toxoplasmosis is usually benign

A

trye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how many peeps are infected by toxo

A

30-60% are infected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

why is toxo mostly benign

A

because the immune response is super efficient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

when are symptoms for acute toxoplasmosis show usually

A

1-3 weeks post infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the acute stage of toxo

A

virulent tachyzoites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The acute stage (virulent tachyzoites) fades in a few days to weeks, leading to ……

A

the latent stage of the infection aka bradyzoite tissue cysts which is normally asymptomatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

when is toxo benign

A

-aids peeps
-during pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

aids patients: toxo

A

toxoplasmosis can develop. The most notable manifestation is toxoplasmic encephalitis, which is fatal without drug treatment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
primary infection of toxo during pregnancy
possibly leading to hydrocephaly, microcephaly, intracranial calcification, and chorioretinitis, with the possibility of miscarriage or intrauterine death. Ocular toxoplasmosis may develop later in life.
26
infection of toxo during 1st trimester
incidence of transplacental infection is low (15%) but the disease in neonates is most severe.
27
infection of toxo during 3rd trimester:
– the incidence of transplacental infection is high (65%) but the infant is usually asymptomatic at birth.
28
what is the symptomatic phase of toxo in aids
Symptomatic phase when CD4+ T cell count < 200 cells/µl due to tissue cyst reactivation -- toxoplasmic encephalitis (TE)
29
true or false: the tachyzoite of toxo is the acute phase of toxo
it is the acute/invasive/proliferatibe stage
30
what are the rhoptries in toxo
unique secretory/excretory organelles found exclusively in the Apicomplexa. -Important at the time of invasion and critical in the establishment of a productive infection
31
what are dense granules
secrete their contents during and after invation -major t cell antigen for class 1 mhc
32
true or false: in toxo they have stage specific surface antigens
-true they are known as adhesins
33
in toxo: GPI-anchored proteins, which act as redundant receptors for binding to...
sulf proteoglycans on various host cells
34
what is the dormant stage of toxo
-the bradyzoite -aka the dormant stage
35
true or false: bradyzoite looks like tachyzoite
true -But distinct antigenically and physiologically (different set of SAG surface antigens)
36
what are the reserve of carbohydrates for toxo
amylopectin granules
37
bradyzoites of toxo live where and are derived from what
- in tissue cysts,w hich are derived from a parasitophorous vacuole and a cyst wall
38
how big are bradyzoites
10-200 um
39
the dormant stahe of toxo is found where
found in muscles (infective stage), brain
40
unlike tachyzoite in toxo, bradyzoites are resistant to what
low ph and host digestive proteases in the stomach
41
The transition from tachyzoite to bradyzoite is associated with morphological changes:....
narrowing of the parasite body, movement of the nucleus toward the parasite posterior, an increase in the number of micronemes (blue) and amylopectin granules (white), and more electron-dense rhoptries (maroon).
42
one stress response pathway in toxo linked to stage conversion involves what
phosphorylation of the alpha subunit of eukaryotic initiation factor-2 (TgIF2α), which is mediated by stress-activated TgIF2α kinases (TgIF2Ks).
43
what is the sexual stage for toxo
the sporozoite/oocyst
44
how big is the toxo ooxyst
13um in size
45
the oocyst of toxo is resistant stage viable in moist soil for ...
18 months
46
the oocyst is a product of what
-product of sexual cycle (micro- and macrogametes), which occurs in the intestinal cells of definitive hosts (cats)
47
oocyst in toxo are passed out in the feces of ...
s by definitive hosts/carnivores (cat) feces-10-14 days after infection
48
true or false: in toxo, each oocysts contain 4 sporocysts
false, it is 2
49
true or false: oocysts are infective to humans and other herbivore hosts
true
50
oocysts of toxo are resistant to what
Physical agents UV, dessication, freezing Chemical agents Ozone, bleach, iodine, ethanol, formalin, salts
51
persistence of oocysts toxo
18 months in soil 54 months in water
52
true or false: is unsporulated and non-infectious when excreted
true
53
what do toxo oocysts contain
it contains a single, undifferentiated cytoplasmic mass and is essentially the zygote stage of the parasite surrounded by a protective wall
54
in toxo: sporulation occurs by what
meiotic division
55
meotic division in toxo oocysts
During this process, the cytoplasm divides into a characteristic number of sub-masses (secondary sporoblasts), which develop a resistant wall and are termed sporocysts. Within the sporocysts, the infectious stages (sporozoites) are formed. The sporozoites are thus protected by both the oocyst and sporocyst walls
56
how many sporozoites are in a sporocyst
4
57
true or false: can shed oocysts in their feces for several weeks after the initial contamination
true
58
how long do oocysts of toxo can become infectuous
1-2 days
59
how many % of cats shed oocyst at any one time
2%
60
oocyst of toxo shedding does not recur after....
even after repeated exposure to the parasite
60
true or false: toxo oocysts have been detected on cat fur and in their infectuous form
false: in their non infectuous form
61
when was the outbreak of toxo in bc
1995 on vancouver island
62
which parasite is a significant cause of death of sea otters
toxo -38% of lil sea otters had toxo
63
true or false: toxo is a threat for the safety of public water supplies
true
64
what is the type of immune response to toxo
controlled by cell mediated immunity -cd8 are the major effectors -cd4 are important for regulation of immune response -nk and macrophages are the first line of defense
65
what cytokine is important for th1 response to toxo gondii
il12 -you also have infy to kill intracellular parasites
66
true or false: it is hard to show that someone is infected by toxo
yeah because it is intracellular
67
how is toxo diagnosed
Acute infection is assessed by serology (IgG & IgM) IgG antibodies usually appear 1 to 2 weeks after the initiation of infection, reaching peak titers in 6 to 8 weeks, then gradually decline over 1 to 2 years.
68
how are the titers for toxo
-usually low -persists for life
69
true or false: toxo titers correlates with disease severity
false it does not
70
how is acute infection of toxo diagnosed?
-serology -elisas are available and now preferred
71
intra-uterine and cerebral disease of toxo can be diagnosed how
pcr
72
treatment of toxo acute
-pyrimethamine -sulfadiazine -clindamycin -spiramycin
73
treatment of toxo chronic
-tissue cyst are resistant to most treatment -atovaquone -clindamycin
74
why is toxo so sucessful
-it is protected from many immune effector mechanisms because it is intracellular -can infect any nucleated cell in any warm blooded vertebrate
75
the vacuole of toxo are resistant to what
fusion with the host cell lysosomes
76
true or false: t gondii manipulated host cell processes
true
77
what does T gondii manipulate
host cells and immune effectors
78
why are toxo hosts rarely killed
A balanced host-parasite interaction is established and is necessary for T. gondii survival, persistence and transmission
79

MIMM 413 (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions