Microsporidia hyperparasitic in anoplocephalid cestodes
Dissanaike, A. S;
(1955)
Microsporidia hyperparasitic in anoplocephalid cestodes.
PhD thesis, London School of Hygiene & Tropical Medicine.
DOI: https://doi.org/10.17037/PUBS.00682403
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1. A review of the protozoa reported from animal-parasitic
helminths is first made.
2. A detailed, description is given of the morphology
of the microsporidian found in Moniezias in this
country.
3. This parasite has been shown to be identical with
Nosema helminthorum Moniez, 1887, Plistonhora
helminthophthora Labbe, 1899, and Nosema bischoffi
Weiser, 1951. The valid name for this organism
therefore is Nosema helminthorum Moniez , 1887.
4. A 'pre- metachromatic granule' appearing in the sporont
stages, and the metachromatic bodies of the mature
spores have been studied from the point of view of
their chemical nature.
5. The spore wall of this parasite has been proved to
consist of chitin.
6. The mode of emergence of the sporoplasm has been shown
to occur in a manner hitherto unobserved in microsporidia.
7. N. helminthorum has been shown to infect Hymenolepisnana of mice and rats, under experimental conditions.
In three tapeworms, this microsporidian undergoes a
similar development to that in the Moniezias, but the
spores assume a smaller size.
8. A Taenia aaginata of man was also infected with
this organism but only early division stages were
obtained.
9. Two oribatid mites Xebillus tegeocranus and
Ceratoppia bipilis were fed on the spores of
N. helminthorum, and the cells of the midguts of
these mites became infected. The spores appearing in
the mites were smaller than those in the mice worms.
10. The significance of the experinmental infections has been
discussed, and the life-cycle of N. helminthorum has
been described from them.
11. The host distribution and the geographical distribution
of N. helminthorum and its host-parasite relationships
have been considered. This parasite is shown to be non-pathogeneic and the question of its host-restriction
has been discussed.
12,. A paraneoxenous association between Giardia ovis
and Nematodirus fillicollis of sheep has been discussed.
13. Finally a description is given of a new genus of
schizolregarine and a new species of microsporidian,
from the fat body of the flour beetle Tribolium castaneum. The oöcysts of the schizogregarine were
used in some of the experimental infections of Hymenolepis nana.