Coccidia Flashcards
Phylum_____
•____ forming, microscopic,____-celled parasites
•____ intracellular protozoanà need host cell to reproduce
Apicomplexa
Spore
single
Obligate
Infects_____
– Causes severe____
–____ as diagnostic specimen
–______: confirmatory
gastrointestinal tract
diarrhea
Stool
Stool Culture
Disease:
–______ disease
– Host specific, EXCEPT_______ (all mammals)
Coccidiosis
Toxoplasma gondii
•______ in immunocompromised hosts
– AIDS patients, transplant patients, malnourished children
• May be______ in immunocompetent individuals
Opportunistic
asymptomatic
Members
- Isospora
- Cyclospora
- Cryptosporidium
- Toxoplasma
- Sarcocystis
Alternation of sexual and asexual multiplication
• 3 sequential stages:
1.______ producing micro- (male) and macro-(female) gametocytes (gamonts)
- Sexual cycle or_____ producing oocyst containing sporozoites
- Asexual cycle or_____ producing merozoites (meronts)
Gametogony
Sporogony
Schizogony
Humans are the only known hosts
Cystoisospora/Isospora belli
Cystoisospora/Isospora belli
Transmission:
– ingestion of_______
• (sporulated oocyst contains___ sporocysts each containing___ sporozoites)
• Sporulation of oocyst in food or water
MATURE OOCYST
2; 4
Cystoisospora
Habitat:
distal duodenum and proximal ileum
Cystoisospora
• Microgametes fertilizes the macrogamete and forms the_______ à passed out through the feces
•_______: Embyronic element divides inside the oocyst and forms the 2 sporoblasts
• Sporoblasts matures into______ containing 4 sporozoites each
• Sporulated oocyst is ingested and releases______
• Sporozoites infects intestinal cells where it undergoes______ to produce merozoites
• After several schizogony, some merozoites differentiate and undergo______ to form the microgamete and macrogamete
unsporulated oocyst
SPOROGONY
sporocysts
sporozoites
SCHIZOGONY
GAMETOGONY
Cystoisospora
Asexual and sexual development occur in one host
•________
– Mature oocyst (containing 2 sporocysts, each with 4 sporozoites) when ingested release sporozoites invading intestinal cells of small intestine > trophozoite > merozoites
•________
– Some merozoites develop into macro- and microgametocytes > zygote > ocyst which are passed out with feces and undergo maturation in the environment
Asexual (schizogony)
Sexual (sporogony)
– prolonged mild diarrhea (sometimes lasting for 6 months), abdominal pain, fever, malaise, flatulence
– Malabsorption syndrome with weight loss
– Dissemination of parasites to other organs in AIDS patients
Cystoisosporiasis
Oocyst of I. belli
• A._____
– elongate and ovoidal
– 20-33 u x 10-19 u
• B. ____ with two Sporoblasts
• C.____
– Sporocysts with 4 long and slender sporozoites each
Immature Oocyst
Immature Oocyst
Mature with Sporocysts
Cyclospora cayetanensis
• Originally,______-like body (CLB)
– Photosynthesizing organelles and autofluorescing particles characteristic of blue green algae
• Transmission:
– Ingestion of_____
• 2 sporocysts with 2 sporozoites each
• Habitat:
–______
cyanobacterium
MATURE OOCYST
Small intestine, with jejunum as predilection
Cyclospora cayetanensis
• Ingestion of____ oocyst
• Oocyst releases____ in the intestine
• Sporozoites invade epithelium of small intestine (predominantly jejunum
sporulated
sporozoites
Cyclospora
Sporozoites undergo merogony
- First generation:
Meronts contain____ merozoites - Second generation:
Meronts contain___ merozoites
• Some merozoites develop micro- and macrogamete
8-12
4
•
– Mature oocyst (containing 2 porocysts, each with 4 sporozoites) when ingested release sporozoites invading intestinal cells of small intestine: JEJUNUM àmeronts I (8-12)à meronts II (4)
Asexual (schizogony)
– Some merozoites develop into macro- and microgametocytesà zygote à unsporulated oocyst with feces à maturation in warm environment
Sexual (sporogony)
Generally, self-limiting
– IMMUNITY w/ repeated infections
Clysospora
Other Symptoms
– Fatigue, anorexia, weight loss, nausea, vomiting, abdominal pain, flatulence, bloating, and dyspnea
• D-xylose malabsorption: proximal small intestine malabsorption
• NO DEATHS reported
Clysospora
Clysosporis
Diagnosis
• Direct microscopic examination
• Concentration technique
• Acid fast staining (_____stain)
•______: autofluorescent
– Fluorescent microscopy:
____ or _____
• Polymerase chain reaction
Kinyoun’s stain
Oocyst
blue or green circles
• Infects humans (opportunistic) and other animals
• Intracellular, extracytoplasmic (brush borders)
• Transmission:
– ingestion of thickwalled oocysts from the environment, pets and farm animals
Cryptosporidium
Habitat:
– GIT
• 2 species
– Cryptosporidium hominis (mainly in humans)
– Cryptosporidium parvum
Humans passed out as he awaits thickwalled oocyst
• Oocyst is already mature upon passing out
• When ingested, oocyst releases 4 sporozoites which infects intestinal cells
• Sporozoites undergo SCHIZOGONY to produce merozoites type 1 (8 daughter cells)
Cryptospordium
All stages of development are completed in the gastrointestinal tract of the host
Cryptospordium
