The Apicomplexa (Sporozoa)

Question 1

I. belli: General Characteristics

Answer 1

release of immature oocysts from intestinal wall (all stages of oocytes developement in intestine)
ellipsoid / spindle-shaped with blunt ends
30*12

Question 2

I. belli: Development Cycle

Answer 2

protoplasm –> sporoblasts2 –> heavy cyst walls –> sporocyst2 –> sporozoite*8 (curved , sausage-shaped)
in 4-5 days
all can be seen in small intestine

Question 3

I. belli: Lab Tests

Answer 3

concentrate well with zinc sulfate
1.Sheather’s sugar flotation procedure (best)
2.modified acid-fast (sporoblasts to deep red , oocytes wall stain with precipitation)
3.auramine-rhodamine stains
4.duodenal string test (Enterotest): to recover oocysts
mature/immature oocytes with sporocyte2 with 3012 size

Question 4

I. belli: Pathogenesis

Answer 4

malabsorptive process: loose , pale yellow . foul-smelling stool - increased fecal fat - jejunal villous atrophy
up to 120 days

Question 5

I. belli: Clinical Findings

Answer 5

often asymptomatic and self-limited
raised eosinophilia
mild GI distress to severe dysentery
chronic diarrhea
vague/crampy abdominal pain
weight loss
wakness
malaise
anirexia

Question 6

I. belli: Treatment

Answer 6

1. trimethoprim-sulfamthoxazole - 3 weeks - for chronic infection in immnocompromised
2. pyrimethamine+sulfadiazine
3. pyrimethamine for treatment and prophylaxis

Question 7

Sarcocystis spp.: General Characteristics

Answer 7

by mature intramascular cysts in pork(S. suihominis)/beef(S. hominis)
intermediate host: human
sporocysts contain sporozoite*4

Question 8

Sarcocystis spp.: Development Cycle

Answer 8

zoites –> break the wall of the cyst to intestinal wall –> male microgametes/female macrogametes –> fertilizarion –> zygotes –> oocyst wall formation –> sporogony –> sporocyst2 –> sporozoite8
ruptured oocyst in feces

Question 9

Sarcocystis spp.: Clinical Findings

Answer 9

generally no clinical symptom
within 3-6 until 48 hours
nausea
stomach main
diarrhea
mild stomach pain and diarrhea for 2-3 weeks

Question 10

Cryptosporidium Pavrum: General Characteristics

Answer 10

development within the brush border of intestinal epithelial cells
infective stage: oocytes containing sporozoites
sporulated oocytes containing sporozoites*4 and no sporocyte pass within feces

Question 11

Cryptosporidium Pavrum: Development Cycle

Answer 11

sporozoite –> asexual generation*2 –> gametogony (within epithelial cells)

Question 12

Cryptosporidium Pavrum: Diagnostic Lab Test

Answer 12

1.by identifying meronts containing mrozoites / gamont containing micro-/macrogamete in intestinal biopsy
2.stool containing oocytes
3.Enterotest
4.H&E: small(2-4) round bodies
5.Masson’s stain: blue cytoplasm , red nucleus
6.Giesma’s stain: air-dried + methanol-fixed
7.ELISA
in duodenal biopsy: gamont / meront containing 4 or 8 merozoites
in fresh stool/concentration: oocytes with sporozoite*4 without sporocyst

Question 13

Cryptosporidium Pavrum: Concentration Technique

Answer 13

1. modified zinc sulfate centrifugal flotation technique
2. Sheather’s sugar
3. formalin-ethyl acetate sedimentation + flotation with hypertonic NaCl (separation from stool debris)

Question 14

Cryptosporidium Pavrum: Clinical Findings

Answer 14

human transmitted and zoonist
immunocompetent: 
diarrhea (most common)
anorexia
nausea
fever
abdominal discomfort
weight loss
up to 2 weeks
self-limited
immunocompromised:
\+ malabsorption

Question 15

Cryptosporidium Pavrum: Treatment

Answer 15

nitazoxanide –> self-limited

in AIDS: no treatment except treatment of underlying HIV