1887

Abstract

Despite numerous studies of the parasitic phase, the stages of its nuclear cycle leading to the formation of endoconidia have yet to be properly described. resists culture and can only be investigated on histological preparations. We have evaluated tissue sections collected from 35 host species with rhinosporidosis searching for the presence of mitotic figures during sporangia development. This study found that soon after endoconidia release, the prominent reddish vesicles typical of this stage vanished leading to the development of juvenile sporangia (JS) 12–70 µm in diameter. This stage possesses granular cytoplasm, a thick cell wall, and a central reddish nucleus with a conspicuous nucleolus. The first nuclear division takes place in the JS. It is a rarely encountered event characterized by the development of a distorted nucleus leading to the formation of two nuclei without cytokinesis. The finding of multiple nuclear divisions at prophase-, metaphase- and telophase-like stages without cytokinesis was detected in intermediate sporangia (IS). IS with multiple dividing nuclei seem to be at the same stage of nuclear partitioning, suggesting synchronized nuclear division. In these sporangia, the nuclei continue divisions without cytokinesis until the sporangia reach ≥300 µm in diameter. The last nuclear division prior to cytokinesis appears to take place in very large sporangia with thousands of nuclei. The build-up of cytoplasm around each nucleus and the formation of a thin cell wall lead to the formation of endoconidia. This study revealed the presence of several mechanisms of pathogenesis in that deserved further investigation.

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2013-08-01
2024-12-04
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References

  1. Acevedo P. C. ( 1958). Rhinosporidium seeberi: considerações sôbre morfologia, ciclo parasitário e posição sistemática . Thesis, Facultade de Medicina, Universidade do Pará; Belém, Pará, Brazil:
    [Google Scholar]
  2. Apple D. J. ( 1983). “Papillome” der conjunktiva bedingt durch rhinosporidiose. Fortschr Ophthalmol 79:571–574[PubMed]
    [Google Scholar]
  3. Arseculeratne S. N. ( 2002). Recent advances in rhinosporidiosis and Rhinosporidium seeberi . Indian J Med Microbiol 20:119–131[PubMed]
    [Google Scholar]
  4. Ashworth J. H. ( 1924). On Rhinosporidium seeberi (Wernicke, 1903) with special reference to its sporulation and affinities. Trans R Soc Edinb 53:301–342 [View Article]
    [Google Scholar]
  5. Bader G., Grueber H. L. E. ( 1970). Histochemical studies of Rhinosporidium seeberi . Virchows Arch A Pathol Pathol Anat 350:76–86 [View Article][PubMed]
    [Google Scholar]
  6. Beattie J. M. ( 1906). Rhinosporidium kinealyi: A sporozoon of the nasal mucous membrane. J Pathol Bacteriol 11:270–275 [View Article]
    [Google Scholar]
  7. Easley J. R., Meuten D. J., Levy M. G., Dykstra M. J., Breitschwerdt E. B., Holzinger E. A., Cattley R. C. ( 1986). Nasal rhinosporidiosis in the dog. Vet Pathol 23:50–56[PubMed]
    [Google Scholar]
  8. Fischer A. H., Jacobson K. A., Rose J., Zeller R. ( 2006). Preparation of cells and tissues for fluorescence microscopy. Basic Methods in Microscopy103–123 Spector D. L., Goldman R. D. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
    [Google Scholar]
  9. Herr R. A., Ajello L., Taylor J. W., Arseculeratne S. N., Mendoza L. ( 1999a). Phylogenetic analysis of Rhinosporidium seeberi’s 18S small-subunit ribosomal DNA groups this pathogen among members of the protoctistan Mesomycetozoa clade. J Clin Microbiol 37:2750–2754[PubMed]
    [Google Scholar]
  10. Herr R. A., Mendoza L., Arseculeratne S. N., Ajello L. ( 1999b). Immunolocalization of an endogenous antigenic material of Rhinosporidium seeberi expressed only during mature sporangial development. FEMS Immunol Med Microbiol 23:205–212 [View Article][PubMed]
    [Google Scholar]
  11. Kannan-Kutty M., Teh E. C. ( 1974). Rhinosporidium seeberi: an electron microscopic study of its life cycle. Pathol 6:63–70 [View Article]
    [Google Scholar]
  12. Kannan-Kutty M., Teh E. C. ( 1975). Rhinosporidium seeberi. An ultrastructural study of its endosporulation phase and trophocyte phase. Arch Pathol 99:51–54[PubMed]
    [Google Scholar]
  13. Kennedy F. A., Buggage R. R., Ajello L. ( 1995). Rhinosporidiosis: a description of an unprecedented outbreak in captive swans (Cygnus spp.) and a proposal for revision of the ontogenic nomenclature of Rhinosporidium seeberi . J Med Vet Mycol 33:157–165 [View Article][PubMed]
    [Google Scholar]
  14. Kurunaratne W. A. E. ( 1964). Rhinosporidiosis in Man London: Athlone Press;
    [Google Scholar]
  15. Mendoza L., Herr R. A., Arseculeratne S. N., Ajello L. ( 1999). In vitro studies on the mechanisms of endospore release by Rhinosporidium seeberi . Mycopathologia 148:9–15 [View Article][PubMed]
    [Google Scholar]
  16. Mendoza L., Taylor J. W., Ajello L. ( 2002). The class mesomycetozoea: a heterogeneous group of microorganisms at the animal-fungal boundary. Annu Rev Microbiol 56:315–344 [View Article][PubMed]
    [Google Scholar]
  17. Minchin E. A., Fantham H. B. ( 1905). Rhinosporidium kinealyi n.g., n.sp. a new sporozoan from the mucous membrane of the septum nasi of man. Quart J Microbiol Sci 49:521–532
    [Google Scholar]
  18. Nrao S. N. ( 1966). Rhinospordium seeberi–a histochemical study. Indian J Exp Biol 4:10–14[PubMed]
    [Google Scholar]
  19. Pereira C. N., Di Rosa I., Fagotti A., Simoncelli F., Pascolini R., Mendoza L. ( 2005). The pathogen of frogs Amphibiocystidium ranae is a member of the order dermocystida in the class mesomycetozoea. J Clin Microbiol 43:192–198 [View Article][PubMed]
    [Google Scholar]
  20. Savino D. F., Margo C. E. ( 1983). Conjunctival Rhinosporidiosis. Light and electron microscopic study. Ophthalmology 90:1482–1489[PubMed] [CrossRef]
    [Google Scholar]
  21. Seeber G. R. ( 1900). Un nuevo esporozuario parasito del hombre. Dos casos encontrados en polypos nasales . Thesis, Universidad Nacional de Buenos Aires, Imprenta Libreria “Boullosa”; Buenos Aires, Argentina:
    [Google Scholar]
  22. Silva V., Pereira C. N., Ajello L., Mendoza L. ( 2005). Molecular evidence for multiple host-specific strains in the genus Rhinosporidium . J Clin Microbiol 43:1865–1868 [View Article][PubMed]
    [Google Scholar]
  23. Suga H., Ruiz-Trillo I. ( 2013). Development of ichthyosporeans sheds light on the origin of metazoan multicellularity. Dev Biol 377:284–292 [View Article][PubMed]
    [Google Scholar]
  24. Teh E. C. ( 1974). Surface structure of the endospores of Rhinosporidium seeberi . Sabouraudia 12:263–265 [View Article]
    [Google Scholar]
  25. Teh E. C., Kannan-Kutty M. ( 1975). Rhinosporidium seeberi: spherules and their significance. Pathology 7:133–137 [View Article][PubMed]
    [Google Scholar]
  26. Thianprasit M., Thagerngpol K. ( 1989). Rhinosporidiosis. Curr Top Med Mycol 3:64–85 [View Article][PubMed]
    [Google Scholar]
  27. Vanbreuseghem R. ( 1973). Ultrastructure of rhinosporidium seeberi . Int J Dermatol 12:20–28 [View Article][PubMed]
    [Google Scholar]
  28. Vilela R., Mendoza L. ( 2012). The taxonomy and phylogenetics of the human and animal pathogen Rhinosporidium seeberi: a critical review. Rev Iberoam Micol 29:185–199 [View Article][PubMed]
    [Google Scholar]
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