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Flashcards in Protozoa Deck (81)
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1

The difference between giardia cysts and trophozoites

Cysts
- have 4 nuclei
- this is the infective stage
- found in solid feces
- small
- needs to be stained in order to be seen

Trophozoites
- tear shaped
- have 8 flagella
- found in loose feces

2

Giardia lifecycle

1. giardia are transmitted by ingesting the cyst stage in contaminated food or water. Can survive for months.
2. excystation occurs in teh duodenum
3. replication via longitudinal binary vision (asexual repro)
4. Encystment occurs in the lower intestinal tract - infective cysts passed in feces

3

Giardia duodenalis
Clinical signs

Giardia spp. Clinical signs

- usually none

Giardia spp. Clinical signs:
If any, they will have blunting of intestinal villi leading to malabsorption and diarrhea from damaged enterocytes

4

Giardia duodenalis
Diagnosis

Fecal floatation - for cysts
- use zinc sulfate for detection

ELISA

5

Giardia duodenalis
Treatment

- none approved
- fenbendazole and metronidazole used in dogs and cats
- treat once and everyone else in the household

6

Giardia duodenalis
Control and zoonosis

Control
- bathe animals
- removal of feces
- difficult - resistant cysts

Zoonosis
Not sure if zoonotic, but treat it like it is

7

Trichomonas blagburni
What animal gets it?
Characteristics

- cats
- pseudocysts
- longitudinal binary fission

8

Feline trichomoniasis
Clinical signs

Large-bowel disease
- age of onset ~ 9 months
- chronic diarrhea (blood and/or mucus)
- tenesmus
- Flatulence
- irritated anus
- fecal incontinence: main complaint from clients

9

Feline trichomoniasis
Transmission

- fecal-oral route
- survival outside host: needs nutrient rich substance to survive (diarrhea or water)

10

Feline trichomoniasis
Diagnosis

- direct fecal smear (a fecal would kill it; also super temperature sensitive)
- culture
- PCR
- colonic biopsy

11

Feline trichomoniasis
Treatment and control

No approved treatment
- ronidazole: watch for neuro signs as side effects though!
- metronidazole or tinidazole

- keep infected cats away from other cats
- no litter box sharing

12

How to tell giardia trophozoites from tritchomonas trophozoites

Giardia move gracefully while tritrichomonas is spastic and unorganized

13

Name 3 non-pathogenic trichomonads

1. Pentatrichomonas hominis - found in cecum and colon of mammals
2. Tritrichomonas canistomae and T. Felistomae - found in the mouths of dogs and cats

14

Trypanosomes
- in what species are they found?
- how are they transmitted?
- what does it cause/

- found in blood and tissues of vertebrates
- transmitted by blood feeding arthropods (ie flies)
- mostly non pathogenic

15

Trypanosoma cruzi
- what disease does it cause?
- who is the DH
- who are reservoir hosts
- what vector does it use
- where is it found

- causes American Trypanosomiasis in dogs and cats; causes Chagas disease in humans
- main DH: opossums and racoons
- reservoir hosts/spills over into dogs, cats and armadillos
- uses the reduviid bug (kissing bug) as a vector
- found in Mexico, central and south america; rare in the US

16

Trypanosoma cruzi
Morphology

Uses a trypomastigote for the subterminal kinetoplast

Amastigote (pseudocyst)

17

Trpanosoma cruzi
Lifecycle

1. Metacyclic trypomastigotes are the infective stage; passed in feces of IH. Enter host via bite wound, scratch, etc.
2. Trypomastigoes found in blood; enter cells of spleen, liver, lymphatics and muscle
3. Amastigotes replicate via binary fission form clusters in pseudocysts
4. Cells rupture and trypomastigotes remain in circulation or reinfect
5. Transform into epimastigotes - replicate via binary fission

18

American Trypanosomiasis: Dogs
(Trypanosoma cruzi)
Clinical signs

Acute stage: trypomastigotes in circulating blood

Chronic stage: no longer circulating
- congestive heart failure
- enlarged heart
- arrhythmia
- lethargy
- respiratory difficulties
- hepatomegaly
- anemia

19

Trypanosoma cruzi
Diagnosis

Serological testing
- blood smear

20

Trypanosoma cruzi
Treatment

- low efficacy against chronic disease
- harsh side effects
- treatment over 2 - 3 months: benznidazole, ravuconazole

21

Cystoisospora and Eimeria spp (coccidia)
- in what species are they found
- geography
- how many hosts

- very species specifc ie stenoxenous
- worldwide
- monoxenous - parasitize one host (DH)

22

Difference between cystoisopera and Eimeria eggs

Cystoisopera
- have 2 sporocysts and 4 sporozoites each

Eimeria
- have 4 sporocysts and 2 sporozoites each

23

Name 4 cystoisopora found in dogs

C. Canis
C. Ohioensis
C. Burrowsi
C. Neorivolta

24

Name 2 cystoisopora found in cats

1. C. Felis
2. C. Rivolta

25

Cystoisopera
Lifecycle

1. Undergo schizogony in feline small intestine
2. Undergoes gametogony (sexual reproduction) in epithelial cells of cat
3. Unsporulated oocyst then undergoes sporogony (asexual repro) to sporulated oocyst and makes it infective

26

Cystoisopora spp
Clinical signs and pathogenicity

- occassional diarrhea and death
- enteritis, colitis, weight loss, dehydration
- not zoonotic (species specific)

27

Prevalence of canine coccidiosis

Younger animals will have highest incidence of infection

Older animals serve as carriers and reservoirs

28

Cystoisopora
Control

- kennel sanitation; prompt feces removal
- disinfectants with high ammonia concentrations
- treatl all animals
- use steam or heat with disinfectants

29

Coccidosis treatment in dogs and cats

Sulfadimethoxine
Sulfaguanidine
Furazolidone
TMS
Sulfadimethoxine/ormetoprim
Quinacrine
Amprolium
Toltrazuril
Diclazuril
Ponazuril

30

Eimeria - is it a spurious parasite?

Yes; usually in dogs, sometimes in cats
Spurious = pseudoparasite.

When you see this its usually bc the dog ate another animal's poop

NOT A TRUE PARASITE OF THE DOG/CAT