Toxoplasma gondii Flashcards Preview

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Flashcards in Toxoplasma gondii Deck (24):
1

order

eucoccindiorida- parasite of epithelial cells

2

hosts

cats and other felids

3

intermediate hosts

humans, dogs, livestock, or birds

4

is there zoonosis?

yes

5

size

12 micrometers

6

what does the oocysts contain once sporulated?

2 sporocysts each with 4 sporozoites

7

life cycle

unsporulated oocysts are shed in cats feces
oocysts form into tachyzoites- rapidly multiply
intermediate host ingest tachyzoites and they localize in muscle tissue and become bradyzoites
cat eats the tissues of the intermediate host with cysts
tissue cysts wall is digested in cats stomach
liberated bradyzoites initiate schizogonous and gametogenous development resulting in production of oocysts

also, organs invade extraintestinal tissues where tachyzoites and bradyzoites proceed as in intermediate host

8

how long do oocysts take to sporulate?

1-5 days

9

how do intermediate hosts become infected?

ingesting soil contaminated with oocysts

10

how do cats become infected

eat the intermediate host harboring tissue cysts or by directly ingesting the sporulated oocysts

11

_____ may also become infected with tissue cysts after ingestion of sporulated oocysts

wild game- liberated sporozoites spread via blood. tissue cysts form containing bradyzoites

12

what is the invasive and proliferative stage?

tachyzoite

13

how can humans become infected?

foodborne- eating raw infected meat
animal to human- ex. cat litter
mother to baby- transplacental

14

what happens in the human host?

parasites form tissue cysts
these cysts remain there throughout the life of the host

15

how are humans diagnosed?

serology or biopsy specimen

16

site of infection

intestinal and extratintestinal tissues

17

pathogenesis

most animals asymptomatic - depends on organs involved
death of intestinal cells
acute toxoplasmosis- severe with FIV
pneumonia

18

diagnosis

serological test
ELISA or IFA tests

19

cats develop ____ after initial infection and shed only ___ in a lifetime

immunity, once

20

how often are oocysts usually shed in cat feces?

1-2 week period

21

treatment

humans avoid feces and eating uncooked meat
no vaccine approved
Nonsulfonamides and sulfonamides

22

serious concern of exposure of human ___ to hazard of death

fetuses

23

what is toxoplasmosis?

transplacental transmission- many side effects to fetus

24

toxoplasmosis can effect either a ____ host or a ____ host

nonimmune, immune