Lecture Quiz 11/10/15 Flashcards
What are the 3 phases of the apicomplexan life cycle?
- Infectious phase
- Proliferative phase
- Sexual reproduction phase
In which of the 3 life cycle phases does sporogony occur?
Infectious phase
What is the product of sporogony in the infectious phase?
Sporozoites
In which of the 3 life cycle phases does gametogony occur?
Sexual reproduction phase
In which of the 3 life cycle phases does merogony (schizogony) occur?
Proliferative phase (asexual)
Which of the following are enteric only?
Isospora
Toxoplasma
Neospora
Sarcocystis
Cryptosporidium
Eimeria
Eimeria
Isospora
Cryptosporidium
Which of the following are enteric and exterintestinal?
Isopsora
Toxoplasma
Neospora
Sarcocystis
Cryptosporidium
Eimeria
Toxoplasma
Neospora
Sarcocystis
What do you call an infection with Eimeria?
Coccidiosis
Which age of animals are more commonly affected by Eimeria?
Younger animals
ALL Eimeria are obligate intracellular parasites. Where, specifically, are they usually found?
Gut epithelial cells AND/OR lacteal endothelium
Others: Kidneys; bile duct
Which species develop clinical signs to Eimeria?
Cattle
Sheep
Goats
Poultry
Rabbits
Camelids
The micropyle cap and micropyle are present in the oocyst of which species?
Eimeria
Eimeria has a direct life cycle; how is it transmitted?
What is the infective stage of Eimeria?
Sporulated oocyst
What is the life cycle of Eimeria as it develops into the infective stage?
A non-sporulated, non-infective oocyst is shed in the feces –> containing a single-celled sporont –> oocyts must undergo sporulation (sporogony) to become infective
Sporont –> ______ –> sporocyst –> ______
Sporont –> sporoblast –> sporocyst –> sporozoite
How many sporoblasts originate from one Eimeria sporont?
4
Explain the process for an Eimeria sporont developing into sporoblasts
1 sporont
2 sporozoites
4 sporoblasts
In Eimeria, how many sporozoites are there per sporocyst?
2
All Eimeria species sporulated oocysts contain :
____ # sporocysts with ____ # sporozoites each
_____ # sporozoites per oocytst
All Eimeria species sporulated oocysts contain :
4 sporocysts with 2 sprozoites each
=
8 sporozoites per oocyst
For Eimeria, where does sporogony occur?
In the environment
What are the environmental requirements of Eimeria sporogony?
Adequate moisture
Adequate oxygen
Adequate temperature
True or False:
- Sporogony in Eimeria species can occur over a range of temperatures.
- Sprogony occurs more rapidly in warmer temperature.
- More oocysts become infective in the fall.
- TRUE
- TRUE
- FALSE - More oocyts become infective in SUMMER
Species?
Eimeria
Merogony is synonymous to what other term?
Schizogony
Once in the host cell, the Eimeria sporozoite becomes what?
Meront
What term is synonymous to meront?
Schizont
The Eimeria meront (schizont) divides by multiple fission and produces what?
Many 1st generation merozoites
Merozoites of the final asexual generation proceed to what?
Gametogony
What type of reproduction is gametogony?
Sexual
True or False:
The trophozoite stage of Eimeria is not infective.
TRUE
Eimeria female gametes:
One merozoite –> one _____ –> one _____
One merozoite –> one macrogametocyte –> one macrogamete
Eimeria male gametes:
One merozoite –> one _____ –> MANY _____
One merozoite -> one microgametocyte –> MANY microgametes
True or False:
- Microgametes remain in host cells.
- Macrogametes exit host cells in search of a microgamete.
- FALSE - microgametes exit host cells in search of a macrogamete.
- FALSE - macrogametes remain in host cells.
After the microgamete fertilizes a macrogamete in the host cell, what develops?
Zygote
What does the zygote become?
Zygote becomes sporont within oocyst
Which Eimeria life stage is represented?
Microgamete
True or Flase:
Eimeria is unspecific to hosts.
FALSE
Each species is VERY host specific.
Ex: A calf is infected with E. zuernii and develops immunity to E. zuernii. That calf is still susceptible to the other 14 Eimeria species that infect cattle.
Clinical disease associated with Eimeria is based on 3 things, what are they?
- Eimeria species involved
- Number of oocysts ingetsed
- Host factors (age, immune status, nutrition)
What are the clinical signs associated with an Eimeria infection?
Enteritis
Anorexia
Decreased feed efficiency
Weight loss
Diarrhea (mucoid to bloody)
Dehydration
Anemia
Clinical parasitism with Eimeria in cattle (bovine coccidiosis) is most often seen at what age?
Calves less than or equal to 6 months old
What are the 3 clinical syndromes of bovine coccidiosis?
Enteric
Winter
Nervous
What clinical signs might be associated with Eimeria: bovine nervous coccidiosis?
CNS signs
GI signs
Muscle tremors
Staggers (nystagmus, convulsions, opisthotonos, +/- blindness)
Explain the mortality rate of Eimeria: bovine nervous coccidiosis.
High mortality rate with OR without treatment
For bovine Eimeria coccidiosis, where might you find lesions associated with asexual replication?
Distal ileum
For bovine Eimeria coccidiosis, where might you find lesions associated with sexual reproduction of the organism?
Cecum
Colon
Provide some prevention and control options for cattle farmers dealing with an Eimeria coccidiosis
Minimize overcrowding
Improve nutrition
Improve sanitation
Keep feces out of food/water supplies
Kill oocysts (sunlight, dessication)
Chemical disinfectants
What is the OBJECTIVE when dealing with / controlling an infection with Eimeria in cattle?
Allow limited exposure to the parasite to stimulate immunity without developing CLINICAL DISEASE
How might Isosporus be transmitted?
- Fecal-oral transmission
- Paratenic host
What is the infective stage of isospora?
Sporulated oocyst
For Isospora, a rodent ingests a sporulated oocyst.
What is then released in the GI tract?
Sporozoite
Where do the sporozoites go once released in the GIT?
Penetrate the gut wall
Enter extra-intestinal cells
What does the sporozoite then form in the tissues?
Monozoic cyst
When the definitive ingests the rodent, what does the monozoic cyst release?
Sporozoite
Once the sporozoite for Isospora is released from the monozoic cyst in the intestine of the definitive host, what process is initiated?
Merogony
In summary, now explain the complete pathogenesis of Isospora infection from a paratenic host.
* Rodent ingests sporulated oocyst *
Sporozoites are released in the GI tract
Sporozoites penetrate the gut wall
Sporozoites enter extra-intestinal cells
Each sporozoite form a monozoic cyst
* Definitve host ingests rodent *
Sporozoite released from monozoic cyst
This initiates merogony in the intestine of the dog or cat
- For cystoisospora, what stage is shed in the feces?
- Where does sporogony occur?
- Where does merogony occur?
- Where does gametogony occur?
- Unsporulated cysts shed in feces
- Sporogony in environemtn
- Merogony in small intestine
- Gametogony in small intestine
True or False:
Cystoisospora is usually non-pathogenic to mildly pathogenic.
TRUE
True or False:
Oocyst shedding of Isospora occurs right before clinical signs develop.
FALSE
Clinical signs precede oocyst shedding
Oragnism?
Isospora
Complete the chart:
What is the name of the Isospora that infects swine?
Cystoisospora suis
What specific disease does Cystoisospora suis cause in swine?
Neonatal porcine coccidiosis (NPC)
What is one characteristic known about the transmission of Cystoisospora suis?
NO paratenic host known
At what age does Cystoisospora suis typically affect pigs?
7-10 days of age
True or False:
- Cystoisospora suis in affected pigs can easily be treated with antibiotics.
- Cystoisospora is more prevalent in the humid periods of summer.
- FALSE - affected pigs are NON-RESPONSIVE to antibiotics
- TRUE
In post-mortem examination of a Cystoisospora suis case, where in the body would you look for gross lesions?
Jejunum
Ileum
On post-mortem examination of Cystoisospora suis, what changes would you see in histology of the jejunum and ileum?
Villus atrophy
+
Parasites
What is the main mode of control of ALL coccidia?
SANITATION
Cryptosporidium is divisible into 2 groups based on location.
What are those 2 locations?
Stomach
Intestines
Which species of Cryptosporidium is probably the main zoonotic species/subspecies affecting immunocompetent people?
Cryptosporidium parvum (genotype II)
In what species can you find Cryptosporidium parvum genotype II?
Cattle
Which Cryptosporidium species is most commonly found in humans?
Cryptosporidium hominis
( parvum genotype I )
Which species of Cryptosporidia infect dogs and cats, respectively, and are considered zoonotic?
Cryptosporidium canis - Dogs
Cryptosporidium felis - Cats
Which organism differs from other Apicomplexans and develops in the enterocyte microvillus border, not in the cytoplasm of host cells?
Cryptosporidium parvum
As for Cryptosporidium, where does sporogony occur?
WITHIN THE HOST
Different from others we’ve talked about!!!!!!
- Which organism produces 2 types of oocytes?
- What are those types?
- Cryptosporidium parvum
- Thick-shelled & Thin-shelled
What is the difference between the thick-shelled oocyst of Cryptosporidium parvum and the thin-shelled oocyst?
Thick-shelled –> Passed in feces –> New host
Thin-shelled –> Can cause autoinfection
In which condition will calves recover as local immunity develops and is considered to be “self-limiting”?
Enteric cryptosporidiosis