Protozoan Parasites

Protozoa

• Single-celled

• eukaryotic

• heterotrophic organisms

• Motile (at least one life stage)

• depend on a host for survival

3 transmission modes of Protozoa

1. Fecal-oral

2. direct contact

3. contaminated environment

Symptoms of Protozoan Infection

GI upset, weight loss, anemia

Locomotion in Protozoa

1. cilia

2. flagella

3. pseudopodia

4. gliding

Feeding Mechanism of Protozoa

• Absorb nutrients

• phagocytosis/pinocytosis

• ciliated protozoa use cytostome

ciliated protozoa use ___ for feeding

cytostome

cytostome

a mouth like structure that ciliated protozoa "push" food toward

Trophozoite

Feeding/reproductive stage of protozoa

Cysts

protective wall formed by protozoa for survival outside host

How do protozoans reproduce 

asexually via mitosis

Amoebic Dysentery is caused by ___

Entamoeba histolytica

Which disease can be passed from humans to dogs & cats

Amoebic Dysentery

The trophozoite stage of Amoebic Dysentery exists only in what 2 places

1. host

2. fresh loose feces

where can Entamoeba histolytica cysts survive outside the host

1. water

2. soils

3. foods

esp under moist conditions

What type of protozoan is the giardia spp.

flagellate

what is the most common protozoan species of importance

Giardia spp.

flagellate, vegetative stage (trophozoites) of Giardia inhabit what area in the body

lumen of small intestine

what do the trophozoites of Giardia attach to on the lumen of small intestine

brush border of epithelial cells

where do trophozoites of Giardia migrate to and encyst in

lower gastrointestinal

most common clinical sign of giardia

• diarrhea

• watery, mucous containing

___ have been shown to inactivate giardia cysts

QACs

what type of protozoan is Leishmania spp

flagellates

Diagnostic test for Giardia spp.

SNAP ELISA

symptoms of Leishmania spp.

• skin lesions

• ocular abnormalities

• epistaxis

how is Leishmania spp. transmitted

sand fly

term for canine disease of Leishmania spp.

• viscerocutaneous

• canine leishmaniosis

Leishmania spp. can also be transmitted ___

• vertically

• from mom to pup

3 types of diagnosis of Leishmania spp

1. PCR

2. ELISA

3. cytology

what can effectively reduce sand fly bites and transmission of leishmaniosis.

Specific repellent topical insecticides

what 2 types of tissue does Trypanosoma cruzi prefer

1. cardiac muscle

2. smooth muscle

tropism

preference for a particular type of tissue

chagas is most recognized in what two animals

1. dogs

2. people

symptoms of Trypanosoma cruzi

• HIGH incidence of sudden death in late stages

• secondary to myocarditis, cardiac arrhythmia, or R sided heart failure​

vector of Trypanosoma cruzi

• kissing bugs

• triatomine bugs

seropositive

giving a positive result in a test of blood serum, e.g. for the presence of a virus.

what type of protozoan is Trichomonas spp.

flagellates

The most important trichomonad in veterinary practice

Tritrichomonas foetus

what does Tritrichomonas foetus cause in cattle

reproductive problems

what does Tritrichomonas foetus cause in cows specifically

• early abortion

• irregular estrous cycle or infertility

• Uterine discharge

• endometritis

• pyometra

what does Tritrichomonas foetus cause in cats

digestive disorders (typhlocolitis)

chronically infected bulls show ___ of digestive disorders Tritrichomonas foetus

no clinical signs

What is a reportable disease

• Tritrichomonas foetus

• STD

where does babesia spp. asexually reproduce

inside the RBC

how is babesia transmitted

Rhipicephalus (Boophilus sp) ticks​

Theileria orientalis

• potential major pathogen in cattle

• considered an emerging disease in US

where is Theileria spp. ​found

• Primarily use WBC for life cycle first

• THEN RBC

#1 prevention strategy against protozoan infections

Sanitation

Emerging Protozoan Threats

Some protozoa (Chagas, Cytauxzoon, Leishmania) are emerging threats in North America

Heterotrophic

Must absorb nutrients from another animal

Arthropod vectors

ingestion by carnivores of organisms within intermediate host

Ciliate pathogen that can infect humans

Balantidium coli

where do Balantidium coli live in

lives in cecum & colon of pigs

Balantidium coli - trophozoites encysted in what type of material

fecal material

effects of Balantidium coli in pigs

• production losses

• poor weight gain

how is Trypanosoma spp. transmitted

tse-tse fly

what can Trypanosoma spp. cause while residing on the skin

• localized inflammation

• chancres

symptoms of Trypanosoma spp.

• fever

• anemia

• weight loss

what type of protozoan is Trypanosoma spp.

flagellates

Surra

different trypanosome transmitted by non tse-tse biting flies

Dourine

Equine trypanosome transmitted via sexual contact

where is Piroplasms​ found

1. red blood cells

2. other circulating cells

3. endothelial cells

vector of piroplasm

"hard" (ixodid) ticks

Three major families of piroplasms of veterinary importance:

1. Babesia spp​

2. Thieleria spp​

3. Cytauxzooan spp

common name for Cytauxzooan felis

bobcat fever

what cells do Cytauxzooan felis target in the cat’s body

1. Infects the macrophages first

2. once released into circulation they infect the red blood cells​

THE largest infectious killer of cats in our geographic region

Cytauxzooan felis

symptoms of Cytauxzooan felis

• Fever

• lethargy

• leukopenia

• thrombocytopenia

• anemia​

what sporozoan parasites can be found in every species

Coccidia

coccidia species with simplest life cycle

Eimeria spp.​

Eimeria spp.​

• inhabit the epithelial lining

• deeper tissues of the GI tract​

what type of pathogen is coccidia considered as

opportunistic pathogen

which part of the coccidia life cycle is resistant to most disinfectants

oocyst

oocyst

a cyst containing a zygote formed by a parasitic protozoan

how is Cytauxzooan felis transmitted

Lone star tick (Ambylomma americanum)

which part of the Cryptosporidium life cycle is resistant to most disinfectants

oocyst

which sporozoan parasite is highly zoonotic 

Cryptosporidium

Cryptosporidium symptoms

• yellowish, mucoid, watery diarrhea

• scours in calves

Equine Protozoal Myelitis (EPM)​ - dead end host

horse

Equine Protozoal Myelitis (EPM)​ - definitive host

oppossum

How can horses get Equine Protozoal Myelitis (EPM)​

eating opossum feces

Toxoplasma gondii complex life cycle usually requires what 2 type of hosts

1. definitive host

2. intermediate host

how does a cat get infected with Toxoplasma gondii

ingest an infected intermediate host

when will cats start to shed infective Toxoplasma gondii cysts

3-10 days after ingestion of intermediate host

how long will cats continue to shed Toxoplasma gondii cysts

10-14 days

how do humans get infected by Toxoplasma gondii

ingestion of oocysts

oocysts in feces must ___ to become infectious

• sporulate

• takes 1-5 days

which disease does CDC estimate 60 million americans might have been infected with​ before

Toxoplasmosis

which cats are more likely to contract Toxoplasmosis​

cats that hunt rodents (like mices or rate)

Toxoplasma gondii

• high rates of infection

• low rates of disease

Equine Protozoal Myelitis (EPM)​ symptoms

• weakness

• ataxia

• muscle wasting