Protozoa III & IV: Apicomplexa Eimeria, Isospora

Question 1

What is sporogony in the Apicomplexa generic life cycle?

Answer 1

Asexual reproduction; a single zygote produces infective sporozites

Question 2

What is merogony (schizogony) in the Apicomplexa generic life cycle?

Answer 2

Asexual reproduction; sporozites undergo a rapid division to become meront stages containing numerous invasive merozoites
Several generations possible, depending on species

Question 3

What is gametogony (gamogony) in the Apicomplexa generic life cycle?

Answer 3

Merozoites differentiate into gametes

Question 4

What is fertilization in the Apicomplexa generic life cycle?

Answer 4

Gametes fuse to produce zygote

Question 5

What is the Coccidian generic life cycle?

Answer 5

Zygote—sporogony—sporozoites—host cell invasion—merozites (which undergo merogony/schizogony)—Gamogony—gametes—fertilization— and the cycle begins again at zygote

Question 6

What is the specificity of Eimeria spp.?

Answer 6

Host specific and site specific

Question 7

What is the most common Eimeria spp. in cattle?

Answer 7

E. zuernii

Also, E. bovis

Question 8

Is Eimeria infectious in a dog or cat?

Answer 8

No

Question 9

Why could Eimeria be seen in the fecal float of a dog?

Answer 9

They eat poop

Question 10

What are the pathogenic species of Eimeria?

Answer 10

E. bovis, E. zuernii (cattle)

E. tenella, E. maxima (chickens)

Question 11

What are Eimeria oocysts like?

Answer 11

Unsporulated when released in feces

Question 12

Where does sporogony occur for Eimeria?

Answer 12

In the environment

Question 13

Describe the Eimeria sporulated oocyst?

Answer 13

Has 4 sporocsyts, each with 2 sporozoites

Question 14

Describe the Eimeria life cycle

Answer 14

Ingested
Sporozoites infect target cells
Merogony
Gametogony
Gametes fuse- oocyst produced

Question 15

What are factors that contribute to the pathology of Eimeria?

Answer 15

Host
Species
Site of infection
Challenge

Question 16

What are general clinical signs of Eimeria?

Answer 16

Severe, watery diarrhea, dehydration
Bloody feces
Loss of weight/decreased weight gain
Lethargy/depression

Question 17

When is damage done with Eimeria?

Answer 17

Once oocysts are present

Question 18

What disease is E. zuernii associated with?

Answer 18

Nervous coccidiosis

Question 19

What is the prepatent period of EImeria in cattle?

Answer 19

2-3 weeks

Question 20

What are the pathogenic Eimeria species in sheep?

Answer 20

E. ahsata
E. ovina
E. ovinoidalis

Question 21

How are the lesions from Eimeria diagnosed?

Answer 21

Direct smear
Lesion scoring
Histology

Question 22

What is the fecal examination of Eimeria?

Answer 22

Sugar flotation, McMaster’s

If identifying oocyst, don’t refrigerate because it delays the sporulation process (48 hour process)

Question 23

What are methods of control for Eimeria?

Answer 23

Anticoccidials: prophylactic treatment
Live cocci vaccines (poultry)
Environmental control (sanitation, litter management)
Animal management (monitoring; mixed ages; prophylactic treatment programs)

Question 24

Describe the direct life cycle of Isospora/Cystoisospora

Answer 24

Unsporulated oocysts shed in environment— sporogony— sporulated—oocysts

Question 25

Describe the Isospora/Cystoisospora oocysts

Answer 25

2 dporocysts with 4 sporozites each

Question 26

What are the target cells of Isospora?

Answer 26

Intestinal

Question 27

What are the target cells of Cystoisospora?

Answer 27

Intestinal development if the definitive host ingests sporulated oocyst Extraintestinal development if paratenic host ingests sporulated oocyst- monozoic tissue cyst form

Question 28

What are the asexual stages of the Isospora/Cystoisospora direct life cycle?

Answer 28

``` Sporozoites invade host intestinal cell and undergo merogony Merozoites formed Invade new host cell Second generation of merozoites Invade new cells ```

Question 29

What are the sexual stages of the Isospora/Cystoisospora direct life cycle?

Answer 29

``` Gametogony: Male/female gametes Fertilization Oocysts produced Passed in feces unsporulated ```

Question 30

Describe the indirect life cycle of Cystoisospora

Answer 30

Insporulated oocysts shed in environment Sporogony Sprulated oocysts (2 sporocysts with 4 sporozoites each)

Question 31

What does the definitive host ingest in the indirect life cycle of Cystoisospora?

Answer 31

Sporulated oocysts

Question 32

What does the paratenic host ingest in the indirect life cycle of Cystoisospora?

Answer 32

Monozoic cysts, then sporozoites released, and infect intestinal cells

Question 33

What are the asexual stages of the Cystoisospora indirect life cycle?

Answer 33

``` Sporozoites invade host intestinal cell undergo merogony Merozoites formed Invade new host cell Second generation of merozoites Invade new cells ```

Question 34

What are the sexual stages of the Cystoisospora indirect life cycle?

Answer 34

``` Gametogony: Male/female gametes Fertilization Oocysts produced Passed in feces unsporulated ```

Question 35

What is the PPP for Isospora/Cystoisospora?

Answer 35

At least 1 week

Question 36

Describe Isospora suis

Answer 36

Neonatal porcine coccidiosis Ubiquitous where pigs are farrowed in confinement 15-20% of swine diarrhea diagnostic cases in US

Question 37

What is the PPP of Neonatal porcine coccidiosis/Isospora suis?

Answer 37

As short as 5 days, oocysts shed in 1-3 weeks

Question 38

What are the clinical signs and pathology os Isospora suis?

Answer 38

``` Diarrhea Dehydration Lethargy Destruction of villus epithelium in SI Mortalities ```

Question 39

What is the diarrhea caused by Isospora suis like?

Answer 39

Develops 7-14 days of age | Pasty yellow; becomes fluid after 2-3 days

Question 40

How is the fecal oocyst of Isospora suis detected?

Answer 40

Fecal flotation

Question 41

What are the control methods of Isospora suis?

Answer 41

Place sows on anticoccidial during third trimester Steam clean facilites Albon and other sulfonamides Baycox

Question 42

Describe Cystoisospora in dogs

Answer 42

Ubiquitous in young dogs | Host specific

Question 43

What are the clinical signs of Cystoisospora in young dogs?

Answer 43

Diarrhea, dehydration, anorexia, weight loss | Asexual/sexual stage destroy intestinal cells

Question 44

At what age is Isospora/Cystoisospora more pathogenic in cats?

Answer 44

4 weeks or younger

Question 45

What are the diagnostics of Isospora/Cystoisospora in dogs and cats?

Answer 45

Fecal oocyst is detected by fecal flotation | Sporulation: 16 hours

Question 46

What are the control methods of Isospora/Cystoisospora in dogs and cats?

Answer 46

Disencourage ingestion of paratenic hosts Sanitation Treat all animals Anticoccidials