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{{Short description|Eukaryotic pathogen}}
{{italic title}}
{{Taxobox
{{Taxobox
| color = khaki
| image =
| image =
| image_caption =
| image_caption =
| regnum = [[Protist]]a
| domain = [[Eukaryota]]
| phylum = [[Choanozoa]]
| unranked_superregnum = [[Opisthokonta]]
| unranked_regnum = [[Holozoa]]
| classis = [[Ichthyosporea]]
| classis = [[Ichthyosporea]]
| ordo = [[Dermocystida]]
| ordo = [[Dermocystida]]
| familia =
| familia = Dermocystidiaceae
| genus = '''''Rhinosporidium'''''
| genus = ''[[Rhinosporidium]]''
|genus_authority=A. Minchin & H. Fantham, 1905<ref>{{GBIF|taxon=''Rhinosporidium'' A.Minchin & H.Fantham, 1905|id=7238413|access-date=10 January 2024}}</ref>
| species = '''''R. seeberi'''''
| species = '''''R. seeberi'''''
| binomial =
| binomial = ''Rhinosporidium seeberi''
| binomial_authority =
| binomial_authority =
|synonyms =
* ''Coccidium seeberi'' <small>Wernicke 1903</small>
* ''Rhinosporidium ayyari'' <small>Allen & Dave 1936</small>
* ''Rhinosporidium equi'' <small>Zschokke 1913</small>
* ''Rhinosporidium kinealyi'' <small>Minchin & Fantham 1905</small>
}}
}}

'''''Rhinosporidium seeberi''''' is a [[eukaryote|eukaryotic]] pathogen responsible for [[rhinosporidiosis]], a disease which affects humans, horses, dogs, and to a lesser extent cattle, cats, foxes, and birds.<ref name="berrocal">{{citation | pmc = 1800950 | title = Nasal rhinosporidiosis in a mule | author = Alexis Berrocal and Alfonso López | journal = Can Vet J. | year = 2007 | month = March | volume = 48 | issue = 3 | pages = 305–306 | pmid = 17436910 }}</ref> It is most commonly found in tropical areas, especially India and Sri Lanka.<ref name="berrocal" /><ref name="morelli" />
'''''Rhinosporidium seeberi''''' is a [[eukaryote|eukaryotic]] pathogen responsible for [[rhinosporidiosis]], a disease which affects humans, horses, dogs, and to a lesser extent cattle, cats, foxes, and birds.<ref name="berrocal">{{cite journal |last1=Berrocal |first1=Alexis |last2=López |first2=Alfonso |title=Nasal rhinosporidiosis in a mule |journal=The Canadian Veterinary Journal |date=March 2007 |volume=48 |issue=3 |pages=305–306 |pmid=17436910 |pmc=1800950 }}</ref> It is most commonly found in tropical areas, especially India and Sri Lanka.<ref name="berrocal" /><ref name="morelli" />


The pathogen was first identified in 1892, and was comprehensively described in 1900 by Seeber.
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.<ref>{{cite journal|last=V|first=Thankamani|journal=SAJOSPS|year=2005|month=Jan-June|pages=118–123|url=http://drthankamani.blog.com/files/2013/04/sajosps-pdf.pdf}}</ref><ref>{{cite journal|last=V|first=Thankamani|coauthors=Lipin Dev M S|title=Demonstration of viability & developmental stages of 10 year old refrigerated culture of Rhinosporidium seeberi (?) UMH.48 first ever isolated from nasal Rhinosporidiosis- Yet another milestone, a tribute to Guillermo Seeber|journal=IJPI’s Journal of Biotechnology and Biotherapeutics|year=2011|volume=1|issue=3|pages=11–21|url=http://www.ijpijournals.com/search.php}}</ref><ref name="Raquel 2012 190">{{cite journal|last=Raquel|first=Vilela|coauthors=Leonel Mendoza|title=The taxonomy and phylogenetics of the human and animal pathogen Rhinosporidium seeberi: A critical review|journal=Revista Iberoamericana de Micología|date=2012.03.012|year=2012|volume=29|issue=4|pages=185–199 [190]|doi=10.1016/j.riam|pmid=22504725|url=http://www.ncbi.nlm.nih.gov/pubmed/?term=The+taxonomy+and+phylogenetics+of+the+human+and+animal+pathogen+Rhinosporidium+seeberi%3A+A+critical+review|accessdate=2012 Oct-Dec}}</ref>
Many aspects of the disease and of the pathogen ''Rhinosporidium seeberi'' remain problematic and enigmatic. These include the pathogen’s natural habitat, some aspects of its ‘lifecycle’, 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, hence paucity of information on its sensitivity to drugs, and the immunology of the pathogen. Thankamani isolated an organism believed to be ''R. 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 ''[[Synchytrium endobioticum]]'', a lower aquatic fungus that causes black wart disease in potatoes. However, carefully performed molecular studies showed the definitive identity of the organism.<ref>{{cite journal |last=V |first=Thankamani |title=''Rhinosporidium Seeberi'' Grown in Culture |journal=Sajosps |date=June 2005 |pages=118–123 |url=http://drthankamani.blog.com/files/2013/04/sajosps-pdf.pdf }}</ref><ref>{{cite journal |last1=Thankamani |first1=V |last2=Lipin-Dev |first2=MS |date=2011 |title=Demonstration of viability and development stages of 10 years old refrigerated culture of Rhinosporidium seeberi (?) UMH. 48 first ever isolated from nasal Rhinosporidiosis yet another milestone, a tribute to Guillermo Seeber |journal=IJPI's Journal of Biotechnology and Biotherapeutics |volume=1 |pages=11–21 }}{{rs|date=January 2024}}</ref><ref name="Raquel 2012 190">{{cite journal|last=Raquel|first=Vilela|author2=Leonel Mendoza |title=The taxonomy and phylogenetics of the human and animal pathogen ''Rhinosporidium seeberi'': A critical review|journal=Revista Iberoamericana de Micología|date=October 2012|volume=29|issue=4|pages=185–199 [190]|doi=10.1016/j.riam.2012.03.012|pmid=22504725}}</ref><ref>{{cite book |first1=Sarath N |last1=Arseculeratne |first2=Dhammika N. |last2=Atapattu |title=Rhinosporidiosis in Humans and Animals & Rhinosporidium seeberi |publisher=Faculty of Medicine, University of Peradeniya |year=2011 |isbn=978-955-589-157-8 }}{{pn|date=January 2024}}</ref>

A recently published book by Sarath N Arseculeratne and Dhammika N.Atapattu on Rhinosporidiosis (Rhinosporidiosis in Humans and Animals & ''Rhinosporidium seeberi''; 2011-1st edition)comprehensively 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.


⚫
<!-- weasel words Incompletely resolved aspects of the disease, such as its epidemiology and pathogenesis, are expected to be understood in detail soon.
-->
== Phylogeny ==
== 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]]<ref name="pmid15735413">{{Citation |author=Arseculeratne SN |title=Rhinosporidiosis: what is the cause? |journal=Curr. Opin. Infect. Dis. |volume=18 |issue=2 |pages=113–8 |year=2005 |month=April |pmid=15735413 |doi= 10.1097/01.qco.0000160898.82115.e8|url=http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?issn=0951-7375&volume=18&issue=2&spage=113 |postscript=.}}</ref> (or "DRIP clade"),<ref name="pmid17657050">{{Citation |author=Arseculeratne SN |title=Recent advances in rhinosporidiosis and rhinosporidium seeberi |journal=Indian J Med Microbiol |volume=20 |issue=3 |pages=119–31 |year=2002 |pmid=17657050 |doi= |url=http://www.ijmm.org/article.asp?issn=0255-0857;year=2002;volume=20;issue=3;spage=119;epage=131;aulast=Arseculeratne |postscript=.}}</ref> 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 [[animal]]s, but diverged from them close to the time when they diverged from each other.<ref name="Raquel 2012 190"/><ref>{{citation | pmc = 85368 | title = Phylogenetic Analysis of Rhinosporidium seeberi’s 18S Small-Subunit Ribosomal DNA Groups This Pathogen among Members of the Protoctistan Mesomycetozoa Clade | author = Roger A. Herr, Libero Ajello, John W. Taylor, Sarath N. Arseculeratne, and Leonel Mendoza1 | journal = J Clin Microbiol | year = 1999 | month = September | volume = 37 | issue = 9 | pages = 2750–2754 | pmid = 10449446 }}</ref> 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]]<ref>{{cite journal|last=V|first=Thankamani|coauthors=Lipin Dev M S|title=Rhinosporidium seeberi proven as a fungus for the first time after a century since its discovery|journal=Research in Biotechnology|year=2012|volume=3|issue=1|pages=41–46|url=http://www.researchinbiotechnology.com/index.php/rib/article/view/71}}</ref>
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]]<ref name="pmid15735413">{{cite journal |last1=Arseculeratne |first1=Sarath Nanda |title=Rhinosporidiosis: what is the cause? |journal=Current Opinion in Infectious Diseases |date=April 2005 |volume=18 |issue=2 |pages=113–118 |doi=10.1097/01.qco.0000160898.82115.e8 |pmid=15735413 |s2cid=38343304 }}</ref><ref>{{cite journal |last1=Fredricks |first1=D N |last2=Jolley |first2=J A |last3=Lepp |first3=P W |last4=Kosek |first4=J C |last5=Relman |first5=D A |title=Rhinosporidium seeberi: a human pathogen from a novel group of aquatic protistan parasites |journal=Emerging Infectious Diseases |date=2000 |volume=6 |issue=3 |pages=273–282 |doi=10.3201/eid0603.000307 |pmid=10827117 |pmc=2640875 }}</ref> (or "DRIP clade"),<ref name="pmid17657050">{{cite journal |last1=Arseculeratne |first1=Sn |title=Recent Advances in Rhinosporidiosis and Rhinosporidium Seeberi |journal=Indian Journal of Medical Microbiology |date=July 2002 |volume=20 |issue=3 |pages=119–131 |doi=10.1016/S0255-0857(21)03243-6 |pmid=17657050 }}</ref> which includes a number of well-known fish pathogens such as ''[[Dermocystidium]]'' and ''[[Sphaerothecum destruens]]''. The Mesomycetozoea are neither part of the fungi nor of [[animal]]s, but diverged from them close to the time when they diverged from each other.<ref name="Raquel 2012 190"/><ref>{{cite journal |last1=Herr |first1=Roger A. |last2=Ajello |first2=Libero |last3=Taylor |first3=John W. |last4=Arseculeratne |first4=Sarath N. |last5=Mendoza |first5=Leonel |title=Phylogenetic Analysis of Rhinosporidium seeberi 's 18S Small-Subunit Ribosomal DNA Groups This Pathogen among Members of the Protoctistan Mesomycetozoa Clade |journal=Journal of Clinical Microbiology |date=September 1999 |volume=37 |issue=9 |pages=2750–2754 |doi=10.1128/JCM.37.9.2750-2754.1999 |pmid=10449446 |pmc=85368 }}</ref>


''Rhinosporidium'' is generally classified as having a single species, although there is some evidence that different host species may be infected by different strains.<ref name="silva">{{citation | pmc = 1081358 | doi = 10.1128/JCM.43.4.1865-1868.2005 | year = 2005 | month = Apr | author = Silva, V; Pereira, Cn; Ajello, L; Mendoza, L | title = Molecular evidence for multiple host-specific strains in the genus Rhinosporidium. | volume = 43 | issue = 4 | pages = 1865–8 | pmid = 15815010 | journal = Journal of clinical microbiology | url = http://jcm.asm.org/cgi/pmidlookup?view=long&pmid=15815010 | format = Free full text }}</ref>
''Rhinosporidium'' is generally classified as having a single species, although some evidence indicates that different host species may be infected by different strains.<ref name="silva">{{cite journal |last1=Silva |first1=Victor |last2=Pereira |first2=Cristiane N. |last3=Ajello |first3=Libero |last4=Mendoza |first4=Leonel |title=Molecular Evidence for Multiple Host-Specific Strains in the Genus Rhinosporidium |journal=Journal of Clinical Microbiology |date=April 2005 |volume=43 |issue=4 |pages=1865–1868 |doi=10.1128/JCM.43.4.1865-1868.2005 |pmid=15815010 |pmc=1081358 }}</ref>


== Epidemiology ==
== Epidemiology ==


Infection in humans with this organism has been reported from ~70 countries, with the majority of cases (95%) reported from [[India]] and [[Sri Lanka]]: per capita, Sri Lanka has the highest incidence in the world. The disease is also found in other parts of the world.<ref name="morelli" >{{citation | pmc = 1560165 | doi = 10.1186/1746-1596-1-25 | year = 2006 | month = Aug | author = Morelli, L; Polce, M; Piscioli, F; Del, Nonno, F; Covello, R; Brenna, A; Cione, A; Licci, S | title = Human nasal rhinosporidiosis: an Italian case report. | volume = 1 | issue = 1| pages = 25 | pmid = 16945122 | journal = Diagnostic pathology | url = http://www.diagnosticpathology.org/content/1//25 | format = Free full text }}</ref><ref>{{citation | pmc = 2007358 | title = Rhinosporidium Seeberi: Pathological Histology and Report of the Third Case from the United States | author = Carl Vernon Weller and Aaron D. Riker | journal = Am J Pathol | year = 1930 | month = November | volume = 6 | issue = 6 | pages = 721–732 | pmid = 19969938 }}</ref><ref>{{citation | pmc = 1680264 | title = Rhinosporidiosis in a Dog | author = B. Hoff and D. A. Hall | journal = Can Vet J. | year = 1986 | month = June | volume = 27 | issue = 6 | pages = 231–232 | pmid = 17422665 }}</ref>
Infection in humans with this organism has been reported from about 70 countries, with the majority of cases (95%) reported from [[India]] and [[Sri Lanka]]; per capita, Sri Lanka has the highest incidence in the world. The disease is also found in other parts of the world.<ref name="morelli">{{cite journal |last1=Morelli |first1=Luca |last2=Polce |first2=Mario |last3=Piscioli |first3=Francesco |last4=Del Nonno |first4=Franca |last5=Covello |first5=Renato |last6=Brenna |first6=Alessia |last7=Cione |first7=Antonio |last8=Licci |first8=Stefano |title=Human nasal rhinosporidiosis: an Italian case report |journal=Diagnostic Pathology |date=December 2006 |volume=1 |issue=1 |page=25 |doi=10.1186/1746-1596-1-25 |pmid=16945122 |pmc=1560165 |doi-access=free }}</ref><ref>{{cite journal |last1=Weller |first1=Carl Vernon |last2=Riker |first2=Aaron D. |title=Rhinosporidium Seeberi: Pathological Histology and Report of the Third Case from the United States |journal=The American Journal of Pathology |date=November 1930 |volume=6 |issue=6 |pages=721–732.11 |pmid=19969938 |pmc=2007358 }}</ref><ref>{{cite journal |last1=Hoff |first1=B. |last2=Hall |first2=D. A. |title=Rhinosporidiosis in a Dog |journal=The Canadian Veterinary Journal |date=June 1986 |volume=27 |issue=6 |pages=231–232 |pmid=17422665 |pmc=1680264 }}</ref>


An all-India survey conducted in 1957 found that this disease was absent from the states of [[Jummu]] and [[Kashmir]], [[Himachal pradesh|Himachal Pradesh]], [[Punjab (India)|Punjab]], [[Haryana]] and the North Eastern states of India. In [[Tamil Nadu]], 4 endemic areas were identified in the survey - ([[Madurai]], [[Ramnad]], [[Rajapalayam]] and [[Sivaganga]]). The common denominator found in these areas was the practice of bathing in common ponds.
An all-India survey conducted in 1957 found that this disease was absent from the states of [[Jammu and Kashmir (union territory)|Jammu and Kashmir]], [[Himachal pradesh|Himachal Pradesh]], [[Punjab (India)|Punjab]], [[Haryana]] and the north eastern states of India. In [[Tamil Nadu]], four endemic areas were identified in the survey—([[Madurai]], [[Ramnad]], [[Rajapalayam]], and [[Sivaganga]]). The common factor found in these areas was the practice of bathing in common ponds.


== Transmission and Dissemination ==
== Transmission and dissemination ==


#[[Demellow]]'s theory of infection {{citation needed|date=June 2013}}
#[[Demellow]]'s theory of infection {{citation needed|date=June 2013}}
#[[Karunarathnae]]'s autoinoculation theory {{citation needed|date=June 2013}}
#[[Karunarathnae]]'s [[autoinoculation]] theory {{citation needed|date=June 2013}}
#Haematogenous spread - to distant sites
#Haematogenous spread – to distant sites
#Lymphatic spread - causing [[lymphadenitis]] (rare)
#Lymphatic spread – causing [[lymphadenitis]] (rare)


Demellow postulated that while bathing in common ponds, the nasal mucosa came into contact with infectious material. Karunarathnae proposed that the satellite lesions in skin and conjunctival mucosa arose as a result of auto inoculation.
Demellow postulated that while bathing in common ponds, the nasal mucosa came into contact with infectious material. Karunarathnae proposed that the satellite lesions in skin and conjunctival mucosa arose as a result of autoinoculation.


It is presumed that because of its relationship to fish pathogens, ''Rhinosporidium'' evolved from aquatic pathogens similar to the other [[Mesomycetozoea]] and evolved to infect mammal and bird hosts. It is not known if this happened once or more than once.<ref name="silva" />
Because of its relationship to fish pathogens, ''Rhinosporidium'' is presumed to have evolved from aquatic pathogens similar to the other Mesomycetozoea and evolved to infect mammal and bird hosts. If this happened once or more than once is unknown.<ref name="silva" />


== Natural habitat ==
== Natural habitat ==


Karunarathnae also proposed that ''Rhinosporidium'' existed in a dimorphic state - a [[saprotroph]] in soil and water and a [[yeast]] form inside living tissues. Recent studies done using Fluorescent in-situ-hybridization techniques provide evidence that its natural habitat is reservoir water, and, perhaps, soil contaminated with this water.<ref>The Identification of the Natural Habitat of Rhinosporidium seeberi with R. seeberi - Specific in situ Hybridization Probes. Kumara Kaluarachchi, Saranga Sumathipala, Navaratne Eriyagama, Dhammika Atapattu, Sarath Arseculeratne. J Infect Dis Antimicrob Agents 2008;25:25-32.</ref>
Karunarathnae also proposed that ''Rhinosporidium'' existed in a dimorphic state—a [[saprotroph]] in soil and water and a [[yeast]] form inside living tissues. Recent studies done using fluorescent ''in situ'' hybridization techniques provide evidence that its natural habitat is reservoir water, and perhaps, soil contaminated with this water.<ref>{{cite journal |author1=Kumara Kaluarachchi |author2=Saranga Sumathipala |author3=Navaratne Eriyagama |author4=Dhammika Atapattu |author5=Sarath Arseculeratne |title=The Identification of the Natural Habitat of ''Rhinosporidium seeberi'' with ''R. seeberi''—Specific in situ Hybridization Probes |journal=J Infect Dis Antimicrob Agents |volume=25 |issue=1 |pages=25–32 |year=2008 |publisher=Infectious Disease Association of Thailand |url=http://www.idthai.org/Publication/pdf/Vol25-1/25-32-Full%20Text.pdf
}}</ref>


== Pathology ==
== Pathology ==
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One report indicates that patients with rhinosporidiosis possess anti-''R. seeberi'' [[Immunoglobulin G|IgG]] to an inner wall [[antigen]] expressed only during the mature sporangial stage. This finding suggests that the mapping of antigenic proteins may lead to important antigens with the potential as vaccine candidates.
One report indicates that patients with rhinosporidiosis possess anti-''R. seeberi'' [[Immunoglobulin G|IgG]] to an inner wall [[antigen]] expressed only during the mature sporangial stage. This finding suggests that the mapping of antigenic proteins may lead to important antigens with the potential as vaccine candidates.


Humoral and Cell-mediated [[Immune system|Immune responses]] in human patients and in experimental mice have been defined; several mechanisms of immune evasion by ''R. seeberi'' have been identified.
Humoral and cell-mediated [[Immune system|immune responses]] in human patients and in experimental mice have been defined; several mechanisms of immune evasion by ''R. seeberi'' have been identified.


A novel method for the determination of the viability of rhinosporidial endospores by MTT-reduction led to the study of the sensitivity of endospores to biocides and [[Antimicrobial|anti-microbial]] drugs (paper in preparation for submission).
A novel method for the determination of the viability of rhinosporidial endospores by MTT-reduction led to the study of the sensitivity of endospores to biocides and [[antimicrobial]] drugs (paper in preparation for submission).


== Clinical features ==
== Clinical features ==
[[Image:Rhinosporidiosis.jpg|thumb|Image showing a large rhinosporidial mass in the [[oropharynx]] of a patient.]]
[[Image:Rhinosporidiosis.jpg|thumb|Image showing a large rhinosporidial mass in the [[oropharynx]] of a patient]]
This organism infects the mucosa of the [[nasal cavity]] producing a mass like lesion. This mass appears to be polypoidal in nature with a granular surface speckled with whitish spores. The rhinosporidial mass has been classically described as a strawberry like mulberry mass. This mass may extend from the nasal cavity into the nasopharynx and present itself in the [[Mouth|oral cavity]]. These lesions commonly cause bleeding from the nasal cavity.
This organism infects the mucosa of the [[nasal cavity]], producing a mass-like lesion. This mass appears to be polypoidal in nature with a granular surface speckled with whitish spores. The rhinosporidial mass has been classically described as a strawberry-like mulberry mass. This mass may extend from the nasal cavity into the nasopharynx and present itself in the [[Mouth|oral cavity]]. These lesions commonly cause bleeding from the nasal cavity.


''Rhinosporidium seeberi'' can also affect the [[lacrimal gland]] and also rarely the skin and genitalia.
''R. seeberi'' can also affect the [[lacrimal gland]] and also rarely the skin and genitalia.


Common sites affected:
Common sites affected:


# Nose - 78%
# Nose – 78%
# Nasopharynx - 68%
# Nasopharynx – 68%
# Tonsil - 3%
# Tonsil – 3%
# Eye - 1%
# Eye – 1%
# Skin - very rare
# Skin – very rare


== Treatment ==
== Treatment ==
Treatment is generally by surgical removal of the infected tissues.<ref name="morelli" />
Treatment is generally by surgical removal of the infected tissues.<ref name="morelli" />


[[Povidone-iodine]] and anti-fungal drugs like [[amphotericin-B]], [[Dapsone]] and [[silver nitrate]] have been suggested as possible antiseptics.<ref name="pmid16687856">{{Citation |author=Arseculeratne SN, Atapattu DN, Balasooriya P, Fernando R |title=The effects of biocides (antiseptics and disinfectants) on the endospores of Rhinosporidium seeberi |journal=Indian J Med Microbiol |volume=24 |issue=2 |pages=85–91 |year=2006 |month=April |pmid=16687856 |doi= 10.4103/0255-0857.25176|url=http://www.ijmm.org/article.asp?issn=0255-0857;year=2006;volume=24;issue=2;spage=85;epage=91;aulast=Arseculeratne |postscript=.}}</ref>
[[Povidone-iodine]] and antifungal drugs such as [[amphotericin B]], [[dapsone]], and [[silver nitrate]] have been suggested as possible antiseptics.<ref name="pmid16687856">{{cite journal |last1=Arseculeratne |first1=SN |last2=Atapattu |first2=DN |last3=Balasooriya |first3=P |last4=Fernando |first4=R |title=The Effects of Biocides (Antiseptics and Disinfectants) on the Endospores of Rhinosporidium Seeberi |journal=Indian Journal of Medical Microbiology |date=April 2006 |volume=24 |issue=2 |pages=85–91 |doi=10.1016/S0255-0857(21)02404-X |doi-access=free }}</ref>


== See also ==
== See also ==
[[List of parasites (human)]]
* [[List of parasites (human)]]


==References==
==References==
Line 85: Line 91:


== External links ==
== External links ==
*{{cite web |title=''Rhinosporidium seeberi'' |work=NCBI Taxonomy Browser |url=https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=90339 |id=90339}}
* [http://www.orlhns.info/index.php?title=Rhinosporidiosis Concise information on Rhinosporidiosis]
* [https://web.archive.org/web/20070927225221/http://www.orlhns.info/index.php?title=Rhinosporidiosis Concise information on Rhinosporidiosis]
* [http://rad.usuhs.edu/medpix/tf_case.html?mode=pt&pt_id=10955#top Rhinosporidium Images]
* [http://rad.usuhs.edu/medpix/tf_case.html?mode=pt&pt_id=10955#top Rhinosporidium Images]
* [http://www.drtbalu.com/rhinosporidiosis.html drtbalu otolaryngology online]
* [http://www.drtbalu.com/rhinosporidiosis.html drtbalu otolaryngology online]
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{{Mycoses}}
{{Mycoses}}
{{Mesomycetozoea}}
{{Mesomycetozoea}}
{{Taxonbar|from=Q3764550}}


[[Category:Mesomycetozoea]]
[[Category:Mesomycetozoea]]
[[Category:Parasitic protists]]
[[Category:Parasitic opisthokonts]]
[[Category:Opisthokont species]]
[[Category:Parasites of mammals]]
[[Category:Parasites of mammals]]

Latest revision as of 16:48, 15 April 2024

Rhinosporidium seeberi
Scientific classification
Domain:
Eukaryota
(unranked):
Opisthokonta
(unranked):
Holozoa
Class:
Ichthyosporea
Order:
Dermocystida
Family:
Dermocystidiaceae
Genus:
Rhinosporidium

A. Minchin & H. Fantham, 1905[1]
Species:
R. seeberi
Binomial name
Rhinosporidium seeberi
Synonyms
  • Coccidium seeberi Wernicke 1903
  • Rhinosporidium ayyari Allen & Dave 1936
  • Rhinosporidium equi Zschokke 1913
  • Rhinosporidium kinealyi Minchin & Fantham 1905

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.[2] It is most commonly found in tropical areas, especially India and Sri Lanka.[2][3]

The pathogen was first identified in 1892, and was comprehensively described in 1900 by Seeber.

Many aspects of the disease and of the pathogen Rhinosporidium seeberi remain problematic and enigmatic. These include the pathogen’s natural habitat, some aspects of its ‘lifecycle’, 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, hence paucity of information on its sensitivity to drugs, and the immunology of the pathogen. Thankamani isolated an organism believed to be R. 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 Synchytrium endobioticum, a lower aquatic fungus that causes black wart disease in potatoes. However, carefully performed molecular studies showed the definitive identity of the organism.[4][5][6][7]

Phylogeny

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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[8][9] (or "DRIP clade"),[10] which includes a number of well-known fish pathogens such as Dermocystidium and Sphaerothecum destruens. The Mesomycetozoea are neither part of the fungi nor of animals, but diverged from them close to the time when they diverged from each other.[6][11]

Rhinosporidium is generally classified as having a single species, although some evidence indicates that different host species may be infected by different strains.[12]

Epidemiology

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Infection in humans with this organism has been reported from about 70 countries, with the majority of cases (95%) reported from India and Sri Lanka; per capita, Sri Lanka has the highest incidence in the world. The disease is also found in other parts of the world.[3][13][14]

An all-India survey conducted in 1957 found that this disease was absent from the states of Jammu and Kashmir, Himachal Pradesh, Punjab, Haryana and the north eastern states of India. In Tamil Nadu, four endemic areas were identified in the survey—(Madurai, Ramnad, Rajapalayam, and Sivaganga). The common factor found in these areas was the practice of bathing in common ponds.

Transmission and dissemination

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  1. Demellow's theory of infection [citation needed]
  2. Karunarathnae's autoinoculation theory [citation needed]
  3. Haematogenous spread – to distant sites
  4. Lymphatic spread – causing lymphadenitis (rare)

Demellow postulated that while bathing in common ponds, the nasal mucosa came into contact with infectious material. Karunarathnae proposed that the satellite lesions in skin and conjunctival mucosa arose as a result of autoinoculation.

Because of its relationship to fish pathogens, Rhinosporidium is presumed to have evolved from aquatic pathogens similar to the other Mesomycetozoea and evolved to infect mammal and bird hosts. If this happened once or more than once is unknown.[12]

Natural habitat

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Karunarathnae also proposed that Rhinosporidium existed in a dimorphic state—a saprotroph in soil and water and a yeast form inside living tissues. Recent studies done using fluorescent in situ hybridization techniques provide evidence that its natural habitat is reservoir water, and perhaps, soil contaminated with this water.[15]

Pathology

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One report indicates that patients with rhinosporidiosis possess anti-R. seeberi IgG to an inner wall antigen expressed only during the mature sporangial stage. This finding suggests that the mapping of antigenic proteins may lead to important antigens with the potential as vaccine candidates.

Humoral and cell-mediated immune responses in human patients and in experimental mice have been defined; several mechanisms of immune evasion by R. seeberi have been identified.

A novel method for the determination of the viability of rhinosporidial endospores by MTT-reduction led to the study of the sensitivity of endospores to biocides and antimicrobial drugs (paper in preparation for submission).

Clinical features

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Image showing a large rhinosporidial mass in the oropharynx of a patient

This organism infects the mucosa of the nasal cavity, producing a mass-like lesion. This mass appears to be polypoidal in nature with a granular surface speckled with whitish spores. The rhinosporidial mass has been classically described as a strawberry-like mulberry mass. This mass may extend from the nasal cavity into the nasopharynx and present itself in the oral cavity. These lesions commonly cause bleeding from the nasal cavity.

R. seeberi can also affect the lacrimal gland and also rarely the skin and genitalia.

Common sites affected:

  1. Nose – 78%
  2. Nasopharynx – 68%
  3. Tonsil – 3%
  4. Eye – 1%
  5. Skin – very rare

Treatment

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Treatment is generally by surgical removal of the infected tissues.[3]

Povidone-iodine and antifungal drugs such as amphotericin B, dapsone, and silver nitrate have been suggested as possible antiseptics.[16]

See also

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References

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  1. ^ "Rhinosporidium A.Minchin & H.Fantham, 1905". Global Biodiversity Information Facility. Retrieved 10 January 2024.
  2. ^ a b Berrocal, Alexis; López, Alfonso (March 2007). "Nasal rhinosporidiosis in a mule". The Canadian Veterinary Journal. 48 (3): 305–306. PMC 1800950. PMID 17436910.
  3. ^ a b c Morelli, Luca; Polce, Mario; Piscioli, Francesco; Del Nonno, Franca; Covello, Renato; Brenna, Alessia; Cione, Antonio; Licci, Stefano (December 2006). "Human nasal rhinosporidiosis: an Italian case report". Diagnostic Pathology. 1 (1): 25. doi:10.1186/1746-1596-1-25. PMC 1560165. PMID 16945122.
  4. ^ V, Thankamani (June 2005). "Rhinosporidium Seeberi Grown in Culture" (PDF). Sajosps: 118–123.
  5. ^ Thankamani, V; Lipin-Dev, MS (2011). "Demonstration of viability and development stages of 10 years old refrigerated culture of Rhinosporidium seeberi (?) UMH. 48 first ever isolated from nasal Rhinosporidiosis yet another milestone, a tribute to Guillermo Seeber". IJPI's Journal of Biotechnology and Biotherapeutics. 1: 11–21.[unreliable source?]
  6. ^ a b Raquel, Vilela; Leonel Mendoza (October 2012). "The taxonomy and phylogenetics of the human and animal pathogen Rhinosporidium seeberi: A critical review". Revista Iberoamericana de Micología. 29 (4): 185–199 [190]. doi:10.1016/j.riam.2012.03.012. PMID 22504725.
  7. ^ Arseculeratne, Sarath N; Atapattu, Dhammika N. (2011). Rhinosporidiosis in Humans and Animals & Rhinosporidium seeberi. Faculty of Medicine, University of Peradeniya. ISBN 978-955-589-157-8.[page needed]
  8. ^ Arseculeratne, Sarath Nanda (April 2005). "Rhinosporidiosis: what is the cause?". Current Opinion in Infectious Diseases. 18 (2): 113–118. doi:10.1097/01.qco.0000160898.82115.e8. PMID 15735413. S2CID 38343304.
  9. ^ Fredricks, D N; Jolley, J A; Lepp, P W; Kosek, J C; Relman, D A (2000). "Rhinosporidium seeberi: a human pathogen from a novel group of aquatic protistan parasites". Emerging Infectious Diseases. 6 (3): 273–282. doi:10.3201/eid0603.000307. PMC 2640875. PMID 10827117.
  10. ^ Arseculeratne, Sn (July 2002). "Recent Advances in Rhinosporidiosis and Rhinosporidium Seeberi". Indian Journal of Medical Microbiology. 20 (3): 119–131. doi:10.1016/S0255-0857(21)03243-6. PMID 17657050.
  11. ^ Herr, Roger A.; Ajello, Libero; Taylor, John W.; Arseculeratne, Sarath N.; Mendoza, Leonel (September 1999). "Phylogenetic Analysis of Rhinosporidium seeberi 's 18S Small-Subunit Ribosomal DNA Groups This Pathogen among Members of the Protoctistan Mesomycetozoa Clade". Journal of Clinical Microbiology. 37 (9): 2750–2754. doi:10.1128/JCM.37.9.2750-2754.1999. PMC 85368. PMID 10449446.
  12. ^ a b Silva, Victor; Pereira, Cristiane N.; Ajello, Libero; Mendoza, Leonel (April 2005). "Molecular Evidence for Multiple Host-Specific Strains in the Genus Rhinosporidium". Journal of Clinical Microbiology. 43 (4): 1865–1868. doi:10.1128/JCM.43.4.1865-1868.2005. PMC 1081358. PMID 15815010.
  13. ^ Weller, Carl Vernon; Riker, Aaron D. (November 1930). "Rhinosporidium Seeberi: Pathological Histology and Report of the Third Case from the United States". The American Journal of Pathology. 6 (6): 721–732.11. PMC 2007358. PMID 19969938.
  14. ^ Hoff, B.; Hall, D. A. (June 1986). "Rhinosporidiosis in a Dog". The Canadian Veterinary Journal. 27 (6): 231–232. PMC 1680264. PMID 17422665.
  15. ^ Kumara Kaluarachchi; Saranga Sumathipala; Navaratne Eriyagama; Dhammika Atapattu; Sarath Arseculeratne (2008). "The Identification of the Natural Habitat of Rhinosporidium seeberi with R. seeberi—Specific in situ Hybridization Probes" (PDF). J Infect Dis Antimicrob Agents. 25 (1). Infectious Disease Association of Thailand: 25–32.
  16. ^ Arseculeratne, SN; Atapattu, DN; Balasooriya, P; Fernando, R (April 2006). "The Effects of Biocides (Antiseptics and Disinfectants) on the Endospores of Rhinosporidium Seeberi". Indian Journal of Medical Microbiology. 24 (2): 85–91. doi:10.1016/S0255-0857(21)02404-X.
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