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''Rhinosporidium seeberi'' is a eukaryotic pathogen responsible for rhinosporidiosis, a disease which affects humans, horses, dogs, and to a lesser extent cattle, cats, foxes, and birds. It is most commonly found in tropical areas, especially India and Sri Lanka.〔〔 The pathogen was first identified in 1892, and was comprehensively described in 1900 by Seeber. There are many aspects of the disease and of the pathogen ''Rhinosporidium seeberi'' which remain problematic and enigmatic. These include, the pathogen’s natural habitat, some aspects of its ‘life cycle’, its immunology, some aspects of the epidemiology of the disease in humans and in animals, the reasons for the delay at ''in vitro'' culture and establishment of disease in experimental animals and hence paucity of information on its sensitivity to drugs, and the immunology of the pathogen. Thankamani isolated an organism believed to be ''Rhinosporidium seeberi'' and gave the name "UMH.48." It was originally isolated from the biopsies and nasal swabs of Rhinosporidiosis patients. The various developmental stages of UMH.48 showed a strong resemblance with the structures seen in hisopathological sections of Rhinosporidiosis in tissue samples. The spores of UMH.48 were found to be viable even after a decade of preservation in the refrigerator without any subculture, resembling the features of ''Synchytridium endobioticum'', a lower aquatic fungus that causes black wart disease in potatoes. However carefully performed molecular studies would show the definitive identity of the organism. discusses recent research developments and clinical associations of this enigmatic disease. Incompletely resolved aspects of the disease, such as its epidemiology and pathogenesis, are expected to be understood in detail soon. == Phylogeny == For most of the 20th century, the classification of ''R. seeberi'' was unclear (being considered either a fungus or a protist), but it was shown to be part of a group called the Mesomycetozoea (or "DRIP clade"), which includes a number of well-known fish pathogens such as ''Dermocystidium'' and the Rosette Agent. The Mesomycetozoea is neither part of the fungi nor of animals, but diverged from them close to the time when they diverged from each other.〔 On the contrary, recent research by 18S rRNA gene sequencing of UMH.48 and fungal extracts of biopsy from new cases of nasal rhinosporidiosis showed 100% identity. Thus UMH.48 has been tentatively identified as a lower aquatic fungus close to ''Colletotrichum truncatum'', ''Glomerulla sps'' and ''Synchytrium minutum''. Based on the absence of a perfect sexual phase and asexual spores, very rare microscopic morphology, life cycle and remarkable resemblance with members of lower aquatic fungi, UMH.48 is identified as a Fungus (unknown) and not an Ascomycete or Protozoan or Mesomycetozoan ''Rhinosporidium'' is generally classified as having a single species, although there is some evidence that different host species may be infected by different strains. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Rhinosporidium seeberi」の詳細全文を読む スポンサード リンク
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