Abstract
The morphological changes occurring inBlastocystis hominis at different time points following in vitro encystment were studied by electron microscopy. The following stages of the parasite were sequentially seen: (a) the amoebic form, which was irregular in shape, with a majority of the organelles being concentrated at the condensed cytoplasmic region; (b) the pre-cystic form, which was rounded and had an electron-dense material forming a homogeneous wall around the central body; and (c) the cystic form, which had a very prominent, thick osmiophilic electron-dense wall, within which there were many inclusions and possibly reproductive granules. The amoebic form appeared to be an intermediate stage between the vacuolar form and the pre-cystic form, as this stage allowed the parasite to ingest bacteria to enhance encystment. The pre-cystic stage had previously been shown in experimental infection to be infective. The role of the cystic stage in producing infection is currently being investigated.
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Suresh, K., Howe, J., Chong, S.Y. et al. Ultrastructural changes during in vitro encystment ofBlastocystis hominis . Parasitol Res 80, 327–335 (1994). https://doi.org/10.1007/BF02351875
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DOI: https://doi.org/10.1007/BF02351875