protozoan parasites with direct life cycles

Question 1

what are protozoa?

Answer 1

-single celled organisms
-very small organisms measured in microns
-eukaryotes
-unknown until the invention of the microscope in 1675

Question 2

what are the examples of disease caused by parasitic protozoa

Answer 2

-amoebic dysentry
-malaria
-sleeping sickness and animal trypanosomiasis
-tick borne diseases of livestock
-toxoplasmosis
-coccidiosis

Question 3

what are the four phyla of parasitic protozoa?

Answer 3

-phylum apicomplexa
-phylum euglenozoa
-phylum ciliophora
-phylum amoebozoa

Question 4

Treating protozoal disease and preventing protozoal infection is…

Answer 4

expensive

Question 5

what is phylum ampicomplexas?

Answer 5

ampicomplexans move by body flexion, all are parasitic, using the apical complex to invade host cells

Question 6

what is phylum euglenozoa?

Answer 6

flagellates move by one or more whip like processes or flagella

Question 7

what is phylum ciliospore?

Answer 7

ciliates move by short hair like processes or cilia

Question 8

what is phylum amoeboxoa

Answer 8

amoebae move by processes or pseudopodia

Question 9

what are some diseases that are coccidia

Answer 9

-eimeria
-toxoplasma
-neospora
-cryptosporidium
-isospora
-sarcocystitis

Question 10

what are some diseases that are piroplasms

Answer 10

-babesia
-theileria

Question 11

what are some diseases that are ciliates

Answer 11

balantidium
rumen
ciliates

Question 12

what are some diseases that are flagellates

Answer 12

-leishmania
-trichomonas
-trypanosoma
-giardia
-histomonas

Question 13

what is a definitive host?

Answer 13

One in which a parasite reaches maturity and usually reproduces sexually

Question 14

what is an intermediate host?

Answer 14

One in which the parasite develops, but does not reach maturity or reproduce sexually

Question 15

what is a vector?

Answer 15

Intermediate host that carries adn transmits parasite developmental stages to another host

Question 16

what is a direct life cycle?

Answer 16

Only definitive host require

Question 17

what is an indirect life cycle?

Answer 17

Requires definitive and intermediate hosts

Question 18

what is a vector-borne life cycle?

Answer 18

Requires definitive host and intermediate host vector

Question 19

what are enteric pathogens?

Answer 19

Direct and indirect life cycles
Water borne or soil transmitted

Question 20

what are haemoparasites?

Answer 20

-Indirect life cycles

-Vector borne-Transmission by mosquitos, tsetse fly, sticks

-Causes fevers, anaemia and worse

Question 21

what are systemic pathogens?

Answer 21

Like Enteric and haemoparasites but more serious

Question 22

what are the basic forms of coccidial parasites?

Answer 22

-trophozoite
-gametes
-oocyst

Question 23

what is the structure of apical complex?

Answer 23

-rhoptries
-micronemes
-polar rings
-conoid

Question 24

what is the function of apical complexes?

Answer 24

-enable parasite to penetrate host cells

-activated by the release of sequestered calcium ions into the parasite cytoplasm

Question 25

how do ampicoplexa enter the host cell?

Answer 25

1. receptor detects host cell 2. reorientation 3. parasite inside vacuole 4. parasitophorous vacuole forming

Question 26

what is special about the way ampicoplexa multiply?

Answer 26

-multiply sexually within host by schizogony -multiple nuclear division precedes cytoplasmic division

Question 27

what are the stages of the eimeria species direct life cycle?

Answer 27

1. Only definitive host is necessary for its completion 2. One phase in host and one in environment 3. Host becomes infected by ingesting sporulated oocysts fmro environment such as food or bedding 4. Sporozoites are released into gut epithelial cells where under go one or more asexual cycles of schizogony 5. Go onto invade further gut epithelial cells and can also form macrogametes or microgames here 6. Microgametes fertilise macrogametes to produce oocysts which are released into the gut lumen and voided in the faeces into the environment 7. Oocysts can survive for months in the environment but must undergo maturation/sporulation to form sporocysts and sporozoites which are infectious once ingested

Question 28

what are the environmental conditions affecting coccidia and disease?

Answer 28

-temperature -humidity -hygiene

Question 29

what are the host factors affecting coccidia and disease?

Answer 29

-age- young -immunity- naive -density- intensification

Question 30

what is the pathology caused by Eimeria tenella?

Answer 30

-thickening of mucosa, inflammation, haemorrhage and necorsis -eimeria tenella has a predilection for the caeca: useful for diagnosis

Question 31

Name a Coccidian species which affects Chickens?

Answer 31

E. tenella E. praecox

Question 32

Name a Coccidian species which affects Cattle?

Answer 32

E. bovis

Question 33

Name a Coccidian species which affects Sheep and goats?

Answer 33

E. ovanoidallis

Question 34

Name a Coccidian species which affects pigs

Answer 34

cystoisospora suis

Question 35

Name a Coccidian species which affects dogs?

Answer 35

cystoisospora canis

Question 36

Name a Coccidian species which affects cats?

Answer 36

cystoisospora felis

Question 37

Name a Coccidian species which affects Rabbits

Answer 37

E. intestinalis E. flavescens

Question 38

what are the infective stages of eimeria?

Answer 38

-unsporulated oocyst requires warmth, moisture and oxygen to sporulate -forms sporulated cyst which can resist disinfection and persist in environment

Question 39

what are the infective stages of eimeria?

Answer 39

-unsporulated oocyst requires warmth, moisture and oxygen to sporulate -forms sporulated cyst which can resist disinfection and persist in environment

Question 40

what is cryptosporiuim parvum?

Answer 40

-A very tin cocidian parasite -Pathogen of domestic animals and humans -Disease: cryptosporidiosis -Common zoonosis Clinical signs= Intermittent anorexia and diarrhoea -No treatment (Self limiting)

Question 41

what happens in autoinfection?

Answer 41

may sporelate before leaving infection and release sporozoites that infect same individual

Question 42

Where is cryptosporidium schizonts located?

Answer 42

-located within brush border

Question 43

where does cryptosporidium schizonts develop?

Answer 43

space between cytoplasm and cell membrane

Question 44

what are some other features of cryptosporidium schizonts?

Answer 44

-intracellular but extracytoplasmic location -infected microvilli are destroyed when the parasite leaves the cells

Question 45

how big are cryoptosporidium oocysts and what are they resistant to?

Answer 45

3-5um in diameter Chlorination

Question 46

is autoinfection possible in cryoptosporidium oocysts?

Answer 46

yes- sporozoites released from oocysts within the intestine may re-infect same individual

Question 47

what are giardia lamlia?

Answer 47

-causes diarrhoea in many birds and mammals e.g. dogs and humans -zoonosis -trophozoites attach with suckers to epithelial cells of the small intestine -the very distinctive trophozoites can sometimes be found in the faeces

Question 48

what are tritrichomonas feoeus features?

Answer 48

-simple direct life cycle -sexual transmission

Question 49

what are the tritrichomonas feoeus features in the bull and the cow

Answer 49

Bull is asymptomatic Cow has... -infertility -abortion -embryonic and early fetal death -fetal maceration -pyometra -vaginal discharge

Question 50

what are the tritrichomonas feoeus features in cats?

Answer 50

typhlocolitis

Question 51

what are the features of spironucleus meleagridis?

Answer 51

-small <10um -catarrhal enteritis in turkey poults and game birds -adult birds are asymptomatic carriers -transmission by faeco-oral route of encysted

Question 52

what are is the presentation of histomonas meleagridis?

Answer 52

'blackhead' in turkeys and chickens

Question 53

what does histomonas meleagridis cause?

Answer 53

-necrotic lesions in the caecum -focal necrosis in liver -cyanosis of head and wattle due to poor blood supply

Question 54

how does histomonas meleagridis migrate?

Answer 54

in portal circulation

Question 55

what is the indirect life cycle of histomonas meleagridis?

Answer 55

-heterakis gallinarium -found in caecum -histomonas invades nematode -histomonas within heterakis eggs

Question 56

what can ingest heterakis eggs?

Answer 56

-birds OR -ingested by and develop within earthworm -bird eats earworm containing heterakis containing histomonas -becomes infected with both parasites simultaneously

Question 57

what is histomonas meleagridis found in?

Answer 57

free range turkeys and chickens