Protozoa I: Intro, Giardia Flashcards by Anika Eidson

What is the basis of classification for protozoa?

Morphological similarities

Animal hosts

How well did you know this?

Not at all

Perfectly

List some protozoa that are important in animals and zoonoses and the diseases associated

Eimeria spp.: Coccidiosis in chickens and other hosts
Toxoplasma gondii, Tritrichomonas foetus, Neospora caninum, Sarcocystis cruzi: reproductive failure in various hosts
Sarcocystis neurona, Toxoplasma gondii: CNS disease

How well did you know this?

Not at all

Perfectly

What are general characteristics of protozoa?

Unicellular/multicellular stages
Eukaryotes with organelles
Aqueous environment to feed/reproduce
Life cycles vary (direct or indirect)
Reproduction includes asexual and sexual stages

How well did you know this?

Not at all

Perfectly

What is the genus and species of Giardia?

Giardia duodenalis

How well did you know this?

Not at all

Perfectly

What is the significance of the geographical distribution of Giardia?

It is the most common flagellate of birds, mammals, reptiles, and amphibians

How well did you know this?

Not at all

Perfectly

What is the host of G/ duodealis Assemblage A?

Humans and other primates, dogs, cats, livestock, rodents, and other wild mammals

How well did you know this?

Not at all

Perfectly

What is the host of G. bovis Assemblage E?

Cattle and other hoofed livestock

Not zoonotic

How well did you know this?

Not at all

Perfectly

How long is the direct life cycle of Giardia?

PPP: 5-7 days

How well did you know this?

Not at all

Perfectly

What is the reproduction of Giardia?

Asexual: binary fission

How well did you know this?

Not at all

Perfectly

What are the stages in the life cycle of Giardia?

Trophozoite

Fecal cyst

How well did you know this?

Not at all

Perfectly

What is the infective stage of Giardia?

Cyst stage in feces that can survive for months

How well did you know this?

Not at all

Perfectly

What are the routes of infection for Giardia?

Fecal-oral

Carnivorism

How well did you know this?

Not at all

Perfectly

What are the sites of infections for Giardia?

Small intestine
Trophozoites encyst in large intestine and the cyst stage is excreted in the feces
Intermittent shedder

How well did you know this?

Not at all

Perfectly

Are Giardia trophozoites mainly in the small intestine or large intestine?

Small intestine

How well did you know this?

Not at all

Perfectly

What is the motile stage of Giardia?

Trophozoites

How well did you know this?

Not at all

Perfectly

Describe Giardia trophozoites

Size range: 4-10 μm x 10-20 μm
2 nuclei
Flagellated

How well did you know this?

Not at all

Perfectly

What is the best way to find Giardia trophozoites?

Fresh sample (diarrgeic)
Direct smear

How well did you know this?

Not at all

Perfectly

Describe the direct smear for Giardia trophozoites

Look for motile trophozoites

Lugol’s iodine stain

How well did you know this?

Not at all

Perfectly

Describe Giardia fecal cysts

Size range: 4-10 μm x 6-15 μm
4 nuclei
No flagella

How well did you know this?

Not at all

Perfectly

What is the best way to find Giardia fecal cysts?

Flotation with zinc sulfate and Sheather’s solution (main test)
Antigen test
Direct FA test
PCR

How well did you know this?

Not at all

Perfectly

What are the clinical signs of Giardia?

Small bowel diarrhea
Usually young animals
Diarrhea; often intermittent
Malabsorption, weight loss
Mucus, fluid in small intestine
Often associated with concurrent infections

How well did you know this?

Not at all

Perfectly

Describe Giardia in ruminants

Primarily Assemblage E
High prevalence worldwide
Young are more susceptible to acute infections
Adults are chronically infected
Periparturient rise in Giardia cyst excretion in ewes

How well did you know this?

Not at all

Perfectly

What is used to treat Giardia?

Metronidazole
Albendazole
Fenbendazole*

How well did you know this?

Not at all

Perfectly

How can Giardia be controlled?

Environmental control

How well did you know this?

Not at all

Perfectly

What are the epidemiological factors of Giardia?

Cysts immediately infective Water-borne, food-borne, mechanical/transport hosts Population density/poor hygiene/fecal contamination Immune status/concurrent infection Age/passive immunity-colostrum Host specificity/reservoir hosts

What is the definitive host of Histomonas meleagridis?

Turkeys*, chickens, pheasants, guinea fowl

What are the primary sites of Histomonas meleagridis?

Liver and ceca

What is the type of life cycle for Histomonas meleagridis?

Direct life cycle, but Heterakis gallinarum is usually required as transport host

How is Histomonas meleagridis transported?

Via H. gallinarum eggs into bird host

What is the infective stage of Histomonas meleagridis?

Motile trophozoites

What is the primary route of infection for H. meleagridis?

Ingestion of infected embryonated H. gallinrum egg

What is the life cycle of H. meleagridis?

After ingestion, H. gallinarum egg hatches, Histomonas is released in the intestine. It goes systemic via blood vessles, then moves to the liver/ceca and the trophozites undergo binary fission. In the ceca, Histomonas infects Heterakis gallinarum female and is incorporated into nematode eggs

What are alternate infection routes of Histomonas meleagridis?

Paratenic host | Bird to bird transmission: cloacal drinking

What is the most susceptible bird species to Histomonas meleagridis?

Turkeys

What is Histomonas meleagridis the causative agent of?

Blackhead

What are the clinical signs of Blackhead?

``` Lethargy Stilted gate Cyanosis 7-12 days PI Mortality- 17 days PI ```

What are the liver lesions associated with Histomonas meleagridis?

Circular depressions of necrosis, enlarged

What are the ceca lesions associated with Histomonas meleagridis?

Cecal core, ulceration leading to perforation and then peritonitis

What is the treatment for Histomonas meleagridis?

Currently no approved drugs Control of cecal worm: Heterakis gallinarum Avoid cohabitation of bird species, problems with free-range birds

What are the hosts for Trichomonads?

Wide range | Vertebrates: amphibians, birds, mammals, fish, and invertebrates

What are the two categories of species of Trichomonads?

Parasitic and commensal | Commensals are used to rule out if it is parasitic or not

What are the trophozoite characteristics of Trichomonads?

``` 3-5 anterior flagella Undulating membrane Axostyle Single nucleus No cyst stage 4-30 μm Most species are not pathogenic ```

What is the host of Tritrichomonas foetus?

Cattle

What is the location of Tritrichomonas foetus in the female?

Reproductive tract | Vagina/uterus

What is the location of Tritrichomonas foetus in the male?

Sheath of penis | Sometime seminal vesicles and testicles

What is the location of Tritrichomonas foetus in the fetus?

Fluids from abortion | Stomach of aborted fetus

What kind of life cycle does Tritrichomonas foetus have?

Direct life cycle

What is the direct life cycle of Tritrichomonas foetus?

Flagellated trophozoites introduced during coitus--- trophozoites reproduce asexually in reproductive tract via binary fission--- mature trophozoites in 14-20 days PI No cyst stage

What are the symptoms of Tritrichomonas foetus in males?

Males are asymptomatic

What are the signs of Tritrichomonas foetus in females?

``` Repeat breeders Infertility Vaginitis Cervicitis Chronic inflammation of vulva and vagina ```

What are signs of Tritrichomonas foetus in the fetus?

Usually aborted in first 16 weeks

Describe Tritrichomonas foetus trophozites

``` Motile Flagellated Undulating membrane 3 anterior flagella Presence of trophozoites on wet mounts Sample from reproductive tract ---Physiological saline ---The "no-no's" ```

How do you culture Tritrichomonas foetus?

InPouch TF System

What is the treatment for Tritrichomonas foetus?

No drugs approved/available Metronidazole has shown some efficacy Vaccine

How can you control Tritrichomonas foetus?

``` Management strategies evolving and vary Control animal movement; test before introduction of bull/cows AI Test bull annually Use younger bulls Cull positive cows; vaccinate females ```

What does Tritrichomonas blagburni (foetus) cause in Felids?

Feline Trichomoniasis | Intestinal trichomoniasis in cats (large intestine)

What is the transmission of Tritrichomonas blagburni (foetus) in Felids?

Likely: trophozoites transmitted fecal-oral | Breed/age susceptibility (young, pure-bred domestic show cats; group housed)

What is the pathogenesis of Feline Trichomoniasis?

Large bowel inflammation - --Chronic diarrhea/relapses - --Stools hemorrhagic/mucoid

What is the diagnosis of Feline Trichomoniasis?

History of diarrhea: Problem ---FIV, corona virus, FeLV, Cryptosporidium, Giardia Motile trichomonads in feces Culture (InPouch); PCR

How is Feline Trichomoniasis controlled?

Isolation of cats, repeat testing, + cattery

What is the site and pathology of Tritrichomonas foetus in swine?

Site: stomach, colon, nasal passages Pathology: none

What is the site and pathology of Tritrichomonas foetus in dogs?

Site: Large intestine Pathology: Diarrhea

What is the host of Trichomonas gallinae?

Wide range of avian species

What is the location of Trichomonas gallinae in the host?

Primarily upper GI tract | Extraintestinal

What is the Trichomonas gallinae trophozite like?

4 anterior flagella Undulating membrane, axostyle Single nucleus No cyst stage

What is the Trichomonas gallinae life cycle?

Trophozoites introduced orally---- divide (longitudinal binary fission)--- passed to next host orally

What are the routes of infection for Trichomonas gallinae?

Mother---offspring (regurgitation) Water/feed contamination Predator/prey Courtship

What is the pathology for Trichomonas gallinae?

``` "Canker", roup, frounce, trichomoniasis Upper GI tract Invade mucosal surface Caseous lesions Secondary infection Strain differences ```

What is the diagnosis of Trichomonas gallinae?

Gross lesion Direct smear Histopathology

What is the treatment of Trichomonas gallinae?

Dimetronidazole | Environmental control

What has been found to cause infections in a T-Rex?

Trichomonas sp.