Parasitology Exam 3

what is the correctly listed 4 major protozoan classifications

Flagellates, amoeba, ciliates, apicomplexans

what are are the two stages of protozoans

trophozoite, bradyzoite

trophozoite

active, moving, feeding, multiplying form of protozoans

bradyzoite

dormant stage of protozoan in tissue

which protozoans have asexual reproduction

flagellates and amoebas

schizogony

repeated nuclear divisions in protozoa to create a multinuclear cell; one cell splits into multiple at one time

what are the two ways of asexual reproduction in protozoans

schizogony and binary fission

sexual reproduction in protozoans

two cells exchanging genetic information

what happens during the cyst stage of protozoans

can be environmentally resistant, protozoan may replicate inside of the cyst stage ad release one or more organisms from the cyst

what is a stage that some protozoans have

cyst stage

examples of flagellate protozoans

Leishmania, Trypanosoma, Trichomonas, Giardia

flagellates

protozoa with at least one flagellum

what does a flagella do

allow protozoa movement in fluid

Amoebae

protozoa with amorphous shape and pseudopodia

Pseudopodia

false feet found on amoebae protozoa that is a temporary projection in the direction of movement

example of Amoebae protozoa

Entamoeba histolytica

Ciliates

protozoa with cilia

cilia

short hairlike projections on ciliate protozoa that facilitates movement through beating and undulating motions

example of Ciliate protozoa

Balantidium coli

Apicomplexans

banana shaped protozoa without external locomotory organelles that move via undulations

how do apicomplexans move

undulations

what kind of life cycle do apicomplexans have

complex life cycle that is more integrated into the host, some intracellular

Examples of apicomplexans

eimeria, toxoplasma, cryptosporidium, plasmodium, babesia, cytauxozoon

what is the final host of Giardia spp

dog, cat, equine, ruminant, exotic, humans

what kind of protozoa is Giardia spp

flagellate

where is Giardia spp found

intestine of dog, cat, equine, ruminant, exotics, human

what are the two stages of Giardia spp

trophozoite, cyst

where is the trophozoite stage of Giardia spp found

intestines, GI tract of dog, cat, equine, ruminant, humans, exotics

what is the trophozoite stage of Giardia spp and where is it found

motile, pear shaped with 4 flagella pairs and 2 nuclei, found in intestines and GI tract of dog, cat, equine, ruminant, exotics, humans

where is the cyst stage of Giardia spp found

in feces and the environment

what is the cyst stage of Giardia spp and where is it found

resistant, oval shaped with 4 nuclei, found in feces and the environment

what are the methods to diagnose Giardia spp

cysts diagnosed with zinc sulfate centrifugation or Sheather Sugar Solution, trophozoite diagnosed with direct fecal smear, Lugol's iodine used to view internal structures, Giardia ELISA

when is Giardia spp asymptomatic

asymptomatic to diarrhea

how do you diagnose Giardia spp cysts

zinc sulfate centrifugation or Sheather Sugar Solution

what is the downside to using Zinc sulfate centrifugation or Sheather Sugar Solution

Giardia has intermittent shedding periods and may not show up on the test if it is not shedding and cause a false negative

how do you diagnose Giardia spp trophozoites

direct fecal smear, falling leaf

what is Lugol's iodine used for

to view the internal structures of Giardia spp. when diagnosing

what is Giardia ELISA used for, what are the pros and cons

used to diagnose Giardia spp, has less false negatives but can have false positives because an animal can continue to be positive for giardia 3 months after clearing the infection

Giardia species

Giardia duodenalis, Giardia lamblia, Giardia intestinalis

Giardia spp life cycle

Giardia cyst passed in stool, cyst contaminates water or food, food ingested by host, cyst excysts in small intestine, Trophozoite in lumen attaches to brush border of small intestine and absorbs nutrients, trophozoite divides via binary fission, trophozoite encysts in distal small intestine or large intestine, infectious cyst passed in feces can survive weeks to months and can re-infect host

what kind of transmission does Giardia have

fecal oral transmission

cyst

the infective resistant form of a protozoa that survives in the environment

where does giardia attach in the host

brush border of the intestines

what is the order of development of protozoans

trophozoite encysts, becomes a cyst dormant stage, cyst excysts and becomes a trophozoite again

malabsorption

difficulty in the digestion or absorption of nutrients from food

what does Giarida cause in the host

damage to the intestine brush border, proteinase secretion, T. lymphocyte enterocytic injury, protozoal diarrhea

what a protozoan causes in the host

pathophysiology

what is special about Giardia spp development

Giardia has intermittent shedding but trophozoites die if passed in feces, cyst is ingested and excysts in small intestine

can Giardia trophozoites survive in feces

no

Giardia spp treatment

clean and bleach the environment, Fenbendazole panacur, can prescribe metronidazole, bathe pet, ask about coprophagia, probiotics, persistent positive ELISA

Giardia prevention and control

medication, hygiene control, sanitation

Entamoeba histolytica

amebiasis, amebic dysentery

what does Entamoeba histolytica cause

Bloody diarrhea

what are the forms of Entamoeba histolytica

trophozoite, cyst

what kind of protozoa is Entamoeba histolytica

amoeba

where does Entamoeba histolytica infect

large intestine

how does Entamoeba histolytica infect the host

very invasive, invades GI tract mucosa to gain access to vessels and enters the body

what are the factors that can cause an infection of Entamoeba histolytica

pathogen, patient, GI environment

what does an infection of Entamoeba histolytica cause

adherence and damage to colonic epithelial cells or invasion of organs, cytolysis and apoptosis, local damage ulceration, increased permeability of intestine to give protozoa access to organs, proteinase release

what does the inflammatory cytokine release caused by Entamoeba histolytica cause

ulceration, local damage and increased permeability of intestinal epithelial cells provides amoeba protozoa access to host organs

what does a severe infection of Entamoeba histolytica cause

death

why is Entamoeba histolytica hard to kill

it is an amoeba that is bigger than defense cells

what causes amoebic dysentery

bleeding of the intestinal lumen caused by Entamoeba histolytica

how do you diagnose Entamoeba histolytica

fecal float to detect cysts and trophozoites, direct fecal smear

what kind of transmission does Entamoeba histolytica have

fecal oral

Entamoeba histolytica life cycle

cysts and trophozoites in feces, encyst in environment and become infective stage, host eats cyst, cyst excysts into trophozoite in small intestine, trophozoite forms and travels into large intestine and remains in the lumen, can invade mucosa and gain access to blood vessels, can travel to the brain, liver, and lungs, there the trophozoite divides via binary fission, encysts into cyst form and exits via feces

what is the infectious stage of Entamoeba histolytica

mature cysts

what is the infectious stage of Giardia spp

mature cysts

where stages of Entamoeba histolytica are found in feces

cysts and trophozoite

Cystoisospora spp

Coccidia

what is the definitive host of Cystoisospora

canine, feline, swine

what is the definitive host of Entamoeba histolytica

Humans

what kind of protozoan is Cystoisospora

apicomplexan

what is special about Cystoisopora development

it is an obligate intracellular pathogen that requires the host to survive

where is Cystoisospora found

small intestine of canine, feline, swine

apicomplexan development

has both sexual and asexual reproduction

what does Cystoisospora spp cause

watery diarrhea with no blood, typically asymptomatic

how is Cystoisospora diagnosed

oocyst observed on fecal float

oocyst

reproductive life cycle part of Cystoisospora that has multiple immature organisms inside

what is the infective stage of Cystoisospora and where is it found

sporozoite stage inside of oocyst in environment

what does Cytoisospora spp cause

enterocyte and underlying mucosal destruction, diarrhea, malabsorption, maldigestion

what kind of asexual reproduction does Cystoisospora have

mergony

what kind of sexual reproduction does Cystoisospora have

gametogony

Cystoisospora life cycle

infective oocyst ingested, sporozoites released and enter enterocyte, merogony occurs, enterocyte bursts and releases merozoite trophozoite stage, merozoites penetrate new enterocyte, gametogony occurs and creates unsporulated oocysts, enterocyte bursts and releases unsporulated oocysts, oocysts passed in feces and sporulates in the environment

Cystoisospora life cycle inside paratenic host

paratenic host ingests sporulated oocyst, sporozoite released and encysts in enterocyte and becomes dormant bradyzoite stage

what is found in an oocyte of Cystoisospora

2 sporocysts each with 4 sporozoites

how many sporozoites are inside an oocyte of cystoisospora

8

what is the prepatent period of Cystoisospora spp

two weeks

what is special about the oocysts of Cystoisospora

environmentally resistant even to disinfectants

what is the treatment for Cystoisospora spp

sulfonamides, albon sulfadimethoxine

Toxoplasma gondii

toxoplasma

how does Toxoplasma gondii infect the host

ingestion of sporulated oocyst from feces or ingestion of warm-blood animal (rodent or bird) that contain cysts

what is the definitive host of Toxoplasma gondii

feline

what kind of protozoa is Toxoplasma gondii

apicomplexan

how do humans acquire toxoplasmosis

fecal oral, ingestion of undercooked meat, unpasteurized goat milk, contaminated hands and cooking surfaces, unwashed veggies

what does Toxoplasma gondii cause

congenital toxoplasmosis

Toxoplasma gondii incidental host

non feline animals and pregnant humans

what does finding anitbodies in a test mean

the host has a current or prior infection

what does finding antigens in a test mean

the host probably is currently infected with the parasite

what does a negative fecal test for Toxoplasma gondii mean

the cat is not currently shedding oocysts