Diagnostic Parasitology practical spot book (Cestodes)
Page 11 of 21
Slide Number
031
Tapeworms
Taenia saginata (gravid segment)
Longer than broad (2x0.7cm)
Marginal common genital pore
- Uterus, with lateral branches, 15-30 (average 18) on each
side.
Diagnostic Parasitology practical spot book (Cestodes)
Page 12 of 21
Slide Number
032
Tapeworms
Taenia solium (gravid segment):
Resembles that of T. saginata but the number of the lateral
uterine branches is less i.e. 7-12 (average 9) on each side.
Diagnostic Parasitology practical spot book (Cestodes)
Page 13 of 21
Slide Number
Tapeworms
Egg of Taenia spp.:
Both eggs of T. saginata & T. solium are morphologically similar:
Shape: spherical, 30-40u in diameter
Shell: radially striated embryophore
Color: brownish
Content: mature (hexacanth larva)
033
Diagnostic Parasitology practical spot book (Cestodes)
Page 14 of 21
Slide Number
034
Tapeworms
Section in the muscle of an intermediate host (cattle
or pig) showing a cysticercus (larva stage of:
Taenia spp.):
- Oval cyst, lined with germinal epithelium and surrounded by
fibrous tissue reaction of the intermediate host.
- Invaginated scolex (since in the section one can not detect
the presence or absence of hooks, the species of the larva is
not determined)
Diagnostic Parasitology practical spot book (Cestodes)
Page 15 of 21
Slide Number
035
Tapeworms
Jar showing adult Taenia spp.:
Flat, ribbon-shaped segmented worm
Measures several meters x 1cm
Mature segment
Square or slightly broader than long
Common genital pore: marginal, irregularly
alternating
Gravid segment
Longer than broad
Uterus acquires lateral branches
- Determination of the species depends on microscopical
examination of the scolex (for rostellum & hooks) or gravid
segment (for number of lateral uterine branches)
Diagnostic Parasitology practical spot book (Cestodes)
Page 16 of 21
Slide Number
036
Tapeworms
Hymenolepis nana (whole worm)
Size: 1-3cmx1mm
- Scolex: Suckers: 4 true muscular ones Rostellum with one
circles of hooks
- Mature Segment:
• Broader than long (0.5x0.15mm)
• Common genital pore: marginal, unilateral (on same
side)
• Testes: 3; one towards common genital pore and 2
close on the other side.
Ovary: between the testes:
Gravid segment: Broader than long
Uterus: sac full of eggs
Diagnostic Parasitology practical spot book (Cestodes)
Page 17 of 21
Slide Number
037
Tapeworms
Hymenolepis nana egg:
Shape: spherical, 30-50u is diameter
- Shell: 2 coverings: outer than shell and inner embryophore
with 2 polar thickenings, from each arises 4-8 filaments.
Color: translucent
Content: mature (hexacanth larva)
Diagnostic Parasitology practical spot book (Cestodes)
Page 18 of 21
Slide Number
038
Tapeworms
Echinococcus granulosus: (adult worm)
- Size: mall (2-8mm)
- Scolex: globular; 4 true muscular suckers; rostellum with 2
circles of hooks
- Strobila: formed of 3 segments (one immature, one mature
and one gravid)
- Mature segment:
- longer than broad;
- marginal common genital pore;
- one set of male and female genital organs (similar to
those of Taenia spp.)
Gravid segment
- longer than broad
- uterus with lateral pouches
Diagnostic Parasitology practical spot book (Cestodes)
Tapeworms
Egg of Echinococcus spp:
Similar to egg of Taenia spp.
Page 19 of 21
Slide Number
039
Diagnostic Parasitology practical spot book (Cestodes)
Page 20 of 21
Slide Number
Tapeworms
Section in an organ (liver or lung) containing
hydatid cyst
a. Wall consist of:
i. Outer fibrous tissue (host tissue reaction)
ii. Laminated cuticular layer (ectocyt)
iii. Inner germinal layer (endocyt)
040
b. Contents:
i. Scolices
ii. Brood capsules (sacs of germinal layer containing scolices)
iii. Daughter cyst: exogenous & endogenous
iv. Hydatid fluid
Diagnostic Parasitology practical spot book (Cestodes)
Tapeworms
Hydatid sand:
-
Page 21 of 21
Slide Number
041
Scolices: each carries 4 muscular suckers and
invaginated rostellum with hooks
Brood capsules: sacs arising from the germinal layer
in which scolices develop