Histochemical studies of rhinosporidium seeberi

Bader, G.; Grueber, H.L.E.

doi:10.1007/bf00548922

Cited by 22 publications

(5 citation statements)

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“…The significance and role of these electron microscopical findings in the development of endospores are unclear. The electron-lucent inner layer appearing in intermediate sporangia is thought to be composed of cellulose and/or hemicellulose [11]. Savino & Margo [5] suggest that developing endospores arise from this layer and that the older endospores are pushed towards the centre of the sporangia by the younger endospores.…”

Section: Discussionmentioning

confidence: 99%

“…lipid droplets [8] multilamellar bodies [13] in mature endospores: lipid bodies [7,12] cytoplasmic vacuoles [2] sporozoite [5] germinative bodies [11,17] protrusions of the cell wall [11,17] spherules [2,15] electron-dense ciruclar structures [7] electron-dense inclusions [12] [6,15]. Homogenized tissue from a dog's nasal polyp was used to inoculate culture flasks containing monolayers of epithelial human rectal (HRT) cells.…”

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confidence: 99%

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Rhinosporidiosis: a description of an unprecedented outbreak in captive swans (Cygnusspp.) and a proposal for revision of the ontogenic nomenclature ofRhinosporidium seeberi

Kennedy¹,

Buggage

Ajello³

1995

Med Mycol

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Rhinosporidiosis is a mucocutaneous zooanthroponotic disease caused by Rh/nosporidium seeberi, a fungal-like organism of uncertain classification with an unknown mode of transmission. Over a 3 year period, 41 captive swans (Cygnus olor and C. atratus) developed conjunctival and cutaneous polypoid lesions diagnosed as rhinosporidiosis by histopathological examination including light and electron microscopy. Investigation of this avian outbreak, the first of its kind, provides additional insight into the epidemiology of this enigmatic aetiologic agent, which has yet to be isolated and cultivated in vitro. The occurrence of rhinosporidiosis in swans supports an aquatic environment as the reservoir for R. seeberi, which is often associated with exposure to water. We report the first known occurrence of rhinosporidiosis in 41 captive mute (C. olor) and Australian black (C. atratus) swans dwelling on a lake in a Central Florida city. Additionally, we review the development stages of R. seeberi and propose a revision in its ontogenic nomenclature to reflect its probable taxonomic classification as a member of the kingdom Fungi.

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Section: Discussionmentioning

confidence: 99%

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confidence: 99%

Rhinosporidiosis: a description of an unprecedented outbreak in captive swans (Cygnusspp.) and a proposal for revision of the ontogenic nomenclature ofRhinosporidium seeberi

Kennedy¹,

Buggage

Ajello³

1995

Med Mycol

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“…Although the early photographic documentation published in the first part of the 20th century suggested that R. seeberi was a typical eukaryotic microbe with complex stages of its nuclear cycle (Acevedo, 1958;Ashworth, 1924;Kurunaratne, 1964), these observations were conveniently overlooked by the studies of the last 40 years (Apple, 1983;Arseculeratne, 2002;Bader & Grueber, 1970;Easley et al, 1986;Herr et al, 1999b;Kannan-Kutty & Teh, 1974Kennedy et al, 1995;Savino & Margo, 1983;Silva et al, 2005;Teh, 1974;Thianprasit & Thagerngpol, 1989;Vanbreuseghem, 1973). Ashworth (1924) described for the first time in R. seeberi the stages of the nuclear cycle during prophase, metaphase, anaphase and telophase.…”

Section: Discussionmentioning

confidence: 99%

“…Although some investigators using staining protocols recorded the presence of nucleic acids in the EDB (Arseculeratne, 2002) the finding of a true nucleus inside these structures has not yet been documented (Kannan-Kutty & Teh, 1974, Teh, 1974Vanbreuseghem, 1973;Vilela & Mendoza, 2012). Conversely, some histochemical analyses found that these vesicles contain lipidic and proteinaceous elements (Arseculeratne, 2002;Bader & Grueber, 1970;Vanbreuseghem, 1973), a finding that agrees with the position of Ashworth (1924) and Easley et al (1986). Furthermore, our data and other studies showed that the nuclei of R. seeberi are~2-4 mm in diameter (Easley et al, 1986;Thianprasit & Thagerngpol, 1989;Kennedy et al, 1995;Pereira et al, 2005;Savino & Margo, 1983;Vanbreuseghem, 1973;Vilela & Mendoza, 2012), thus the presence of a nucleus inside a 0.5-3.0 mm-diameter vesicle is highly questionable.…”

Section: Discussionmentioning

confidence: 99%

Presumptive synchronized nuclear divisions without cytokinesis in the Rhinosporidium seeberi parasitic life cycle

Mendoza

Vilela

2013

Microbiology

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Despite numerous studies of the Rhinosporidum seeberi parasitic phase, the stages of its nuclear cycle leading to the formation of endoconidia have yet to be properly described. R. seeberi 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 mm 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 mm 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 R. seeberi that deserved further investigation.

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“…Few reports regarding the isolation of these organisms over the laboratory media are documented, however, no confirmation was made over these claims hence it remains uncultivable in media like other organisms (Levy et al, 1986;Arsecularatne and Ajello, 1998). Appropriate specimens involve biopsy tissue from affected areas for punch biopsy, fine-needle aspiration biopsy (FNAB), histochemical studies, cytological and histological examination (Narayanarao, 1966;Bader and Grueber, 1970). Histopathology shows multiple budding sporangia entrenched in fibrovascular stroma infiltrated with chronic inflammatory cells.…”

Section: Diagnosismentioning

confidence: 99%

Rhinosporidiosis: A Riddled Disease of Man and Animals

Tiwari¹

2015

Adv. Anim. Vet. Sci.

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| Rhinosporidiosis is a non-contagious, sporadic, chronic granulomatous infection of man and large domestic animals, characterised by the production of large polyps with high recurrence rate. Polyps occur mainly in nasal, ocular regions; cutaneous and disseminated forms are relatively rare. Spread of these organisms to other areas in an affected person may involve blood, lymph or auto infection. Rhinosporidiosis has been reported form more than 70 countries and mainly the reports are concentrated from Sri Lanka and Southern India. Surgical removal of the polyp will be the cure and in some cases dapsone has given some cure. From the day of inception of this disease there had been a controversy for causative agent of this condition among eukaryotic protozoan parasite or algae or fungi or prokaryotic blue green algae which finally confirmed as a fungi Rhinosporidium seeberi. Recent works by various researchers shows that R. seeberi belong to the class Mesomycetozoea. Other mystery remains in its habitat and its inability to be cultured on laboratory media. Similarly, laboratory animal infection does not yield classical form of disease as it does in human and large animals. The pathogen is so mysterious that the mechanism behind evasion of immune mechanism is also not clear. Still various aspects of disease such as mode of transmission, mechanism of infection, biology of rhinosporidiosis, immunological response and laboratory culture techniques are unresolved mysteries due to paucity of documented data which demands more exploration. This review illustrates main features of rhinosporidiosis and systematic approaches for the diagnosis and treatment of this controversial pathogen.

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Histochemical studies of rhinosporidium seeberi

Cited by 22 publications

References 3 publications

Rhinosporidiosis: a description of an unprecedented outbreak in captive swans (Cygnusspp.) and a proposal for revision of the ontogenic nomenclature ofRhinosporidium seeberi

Rhinosporidiosis: a description of an unprecedented outbreak in captive swans (Cygnusspp.) and a proposal for revision of the ontogenic nomenclature ofRhinosporidium seeberi

Presumptive synchronized nuclear divisions without cytokinesis in the Rhinosporidium seeberi parasitic life cycle

Rhinosporidiosis: A Riddled Disease of Man and Animals

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