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{{About0|Chromoblastomycosis}} | {{About0|Chromoblastomycosis}} | ||
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{{Chromoblastomycosis}} | |||
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==Overview== | ==Overview== | ||
'''''Fonsecaea pedrosoi''''' is a fungal species in the family [[Herpotrichiellaceae]], and the major causative agent of [[chromoblastomycosis]].<ref name=Alviano2004/> This species is commonly found in tropical and sub-tropical regions where it grows as a soil [[saprotroph]].<ref name=DebRoy2013/> Farming activities in the [[endemism|endemic]] zone are a [[risk factor]] for the development of chromoblastomycosis.<ref name=DebRoy2013/><ref name=Nimrichter2005/> | '''''Fonsecaea pedrosoi''''' is a fungal species in the family [[Herpotrichiellaceae]], and the major causative agent of [[chromoblastomycosis]].<ref name=Alviano2004>{{cite journal|last=Alviano|first=D|author2=Franzen, A |author3=Travassos, L |author4=Holandino, C |author5=Rozental, S |author6=Ejzemberg, R |author7=Rodrigues, M |title=Melanin from ''Fonsecaea pedrosoi'' induces production of human antifungal antibodies and enhances the antimicrobial efficacy of phagocytes |journal=Infection and Immunity |year=2004 |volume=72 |issue=1 |pages=229–237 |doi=10.1128/IAI.72.1.229-237.2004|pmid=14688100}}</ref> This species is commonly found in tropical and sub-tropical regions where it grows as a soil [[saprotroph]].<ref name=DebRoy2013>{{cite journal |last=Deb Roy |first=A |author2=Das, D |author3=Deka, M |title=Chromoblastomycosis – A clinical mimic of squamous carcinoma |journal=Mycopathologia |year=2013 |volume=6 |issue=9 |pages=458–460 |doi=10.4066/AMJ.2013.1806}}</ref> Farming activities in the [[endemism|endemic]] zone are a [[risk factor]] for the development of chromoblastomycosis.<ref name=DebRoy2013>{{cite journal |last=Deb Roy |first=A |author2=Das, D |author3=Deka, M |title=Chromoblastomycosis – A clinical mimic of squamous carcinoma |journal=Mycopathologia |year=2013 |volume=6 |issue=9 |pages=458–460 |doi=10.4066/AMJ.2013.1806}}</ref><ref name=Nimrichter2005>{{cite journal|last=Nimrichter|first=L|author2=Cerqueira, M |author3=Leitao, E |author4= Miranda, K |author5=Nakayasu, E |author6= Almeida, S |author7=Rodrigues, M |title=Structure, cellular distribution, antigenicity, and biological functions of ''Fonsecaea pedrosoi'' ceramide monohexosides |journal=Infection and Immunity |year=2005 |volume=73 |issue=12 |pages=7860–7868 |doi=10.1128/IAI.73.12.7860-7868.2005|pmid=16299276}}</ref> | ||
==Classification== | ==Classification== | ||
''[[Fonsecaea]]'' is a genus of [[Ascomycota|ascomycetous]] fungi affiliated with the family [[Herpotrichiellaceae]].<ref name=Najafzadeh2011/> The genus comprises three sibling species, all with pathogenic potential: ''F. pedrosoi'', ''[[Fonsecaea monophora monophora|F. monophora]]'' and ''[[Fonsecaea nubica|F. nubica]]''.<ref name=Najafzadeh2011/> | ''[[Fonsecaea]]'' is a genus of [[Ascomycota|ascomycetous]] fungi affiliated with the family [[Herpotrichiellaceae]].<ref name=Najafzadeh2011>{{cite journal|last=Najafzadeh|first=M|author2=Sun, J |author3=Vincete, V |author4=Klaassen, C |author5=Bonifaz, A |author6=Gerrits van den Ende, A |author7=Sybren de Hoog, G |title= Molecular epidemiology of ''Fonsecaea'' species |journal=Emerging Infectious Diseases |year=2011 |volume=17|issue=3|pages=464–69|doi= 10.3201/eid1703.100555}}</ref> The genus comprises three sibling species, all with pathogenic potential: ''F. pedrosoi'', ''[[Fonsecaea monophora monophora|F. monophora]]'' and ''[[Fonsecaea nubica|F. nubica]]''.<ref name=Najafzadeh2011>{{cite journal|last=Najafzadeh|first=M|author2=Sun, J |author3=Vincete, V |author4=Klaassen, C |author5=Bonifaz, A |author6=Gerrits van den Ende, A |author7=Sybren de Hoog, G |title= Molecular epidemiology of ''Fonsecaea'' species |journal=Emerging Infectious Diseases |year=2011 |volume=17|issue=3|pages=464–69|doi= 10.3201/eid1703.100555}}</ref> | ||
==Ecology and distribution== | ==Ecology and distribution== | ||
''Fonsecaea pedrosoi'' occurs in soil and on plants and trees where it grows as a [[saprotroph]].<ref name=Najafzadeh2011/><ref name=Nimrichter2005/><ref name=Sangwan2013/> It is found predominantly in tropical regions especially South- and Central America.<ref name=Najafzadeh2011/><ref name=Yang2012/> All three recognized species of ''Fonsecaea'' exhibit geographically patterned genetic variation. The closely related species ''F. monophora'' and ''F. nubica'' are distributed worldwide and show the greater population-level [[genetic diversity]] than the geographically restricted ''F. pedrosoi''.<ref name=Najafzadeh2011/> Environmental surveys have documented the recovery of ''F. pedrosoi'' on rotting wood of the Cambara tree, (''[[Gochnatia polymorpha]]'') from the [[Empresa Brasileira de Pesquisa Agropecuária|Brazilian Corporation of Agricultural Research]] forest in [[Colombo, Paraná]], [[Brazil]].<ref name=vicente2001/> It has been also isolated from living trees, stumps, woodpiles and fence posts in central [[Nigeria]].<ref name=okeke1986 /> | ''Fonsecaea pedrosoi'' occurs in soil and on plants and trees where it grows as a [[saprotroph]].<ref name=Najafzadeh2011>{{cite journal|last=Najafzadeh|first=M|author2=Sun, J |author3=Vincete, V |author4=Klaassen, C |author5=Bonifaz, A |author6=Gerrits van den Ende, A |author7=Sybren de Hoog, G |title= Molecular epidemiology of ''Fonsecaea'' species |journal=Emerging Infectious Diseases |year=2011 |volume=17|issue=3|pages=464–69|doi= 10.3201/eid1703.100555}}</ref><ref name=Nimrichter2005>{{cite journal|last=Nimrichter|first=L|author2=Cerqueira, M |author3=Leitao, E |author4= Miranda, K |author5=Nakayasu, E |author6= Almeida, S |author7=Rodrigues, M |title=Structure, cellular distribution, antigenicity, and biological functions of ''Fonsecaea pedrosoi'' ceramide monohexosides |journal=Infection and Immunity |year=2005 |volume=73 |issue=12 |pages=7860–7868 |doi=10.1128/IAI.73.12.7860-7868.2005|pmid=16299276}}</ref><ref name=Sangwan2013>{{cite journal |last1=Sangwan |first1=Jyoti |last2=Jachuck|first2=SJ |title=''Fonsecaea Pedrosoi'': A rare etiology in fungal keratitis |journal=Journal of Clinical and Diagnostic Research |year=2013 |doi=10.7860/JCDR/2013/6627.3491}}</ref> It is found predominantly in tropical regions especially South- and Central America.<ref name=Najafzadeh2011>{{cite journal|last=Najafzadeh|first=M|author2=Sun, J |author3=Vincete, V |author4=Klaassen, C |author5=Bonifaz, A |author6=Gerrits van den Ende, A |author7=Sybren de Hoog, G |title= Molecular epidemiology of ''Fonsecaea'' species |journal=Emerging Infectious Diseases |year=2011 |volume=17|issue=3|pages=464–69|doi= 10.3201/eid1703.100555}}</ref><ref name=Yang2012>{{cite journal|last=Yang|first=Y|author2=Yongxuan, H |author3=Zhang, J |author4= Li, X |author5=Lu, C |author6= Xi, L |title= A refractory case of chromoblastomycosis due to ''Fonsecaea monophora'' with improvement by photodynamic therapy|journal = Medical Mycology 2012 |volume=50|issue=1|pages=649–653|doi=10.3109/13693786.2012.655258 |year=2012|last7=Xi|first7=Liyan}}</ref> All three recognized species of ''Fonsecaea'' exhibit geographically patterned genetic variation. The closely related species ''F. monophora'' and ''F. nubica'' are distributed worldwide and show the greater population-level [[genetic diversity]] than the geographically restricted ''F. pedrosoi''.<ref name=Najafzadeh2011>{{cite journal|last=Najafzadeh|first=M|author2=Sun, J |author3=Vincete, V |author4=Klaassen, C |author5=Bonifaz, A |author6=Gerrits van den Ende, A |author7=Sybren de Hoog, G |title= Molecular epidemiology of ''Fonsecaea'' species |journal=Emerging Infectious Diseases |year=2011 |volume=17|issue=3|pages=464–69|doi= 10.3201/eid1703.100555}}</ref> Environmental surveys have documented the recovery of ''F. pedrosoi'' on rotting wood of the Cambara tree, (''[[Gochnatia polymorpha]]'') from the [[Empresa Brasileira de Pesquisa Agropecuária|Brazilian Corporation of Agricultural Research]] forest in [[Colombo, Paraná]], [[Brazil]].<ref name=vicente2001>{{cite journal|last1=Vicente|first1=Vânia Aparecida|last2=Angelis|first2=Derlene Attili de|last3=Queiróz-Telles Filho|first3=Flávio|last4=Pizzirani-Kleiner|first4=Aline Aparecida|title=Isolation of herpotrichiellacious fungi from the environment|journal=Brazilian Journal of Microbiology|date=2001|volume=32|issue=1|pages=47–51|doi=10.1590/S1517-83822001000100011}}</ref> It has been also isolated from living trees, stumps, woodpiles and fence posts in central [[Nigeria]].<ref name=okeke1986>{{cite journal |last1=Okeke |first1=CN |last2=Gugnani |first2=HC |title=Studies on pathogenic dematiaceous fungi. 1. Isolation from natural sources |journal=Mycopathologia |year=1986 |volume=94 |issue=1 |pages=19–25 |pmid=3724831 |doi=10.1007/bf00437257}}</ref> | ||
==Physiology== | ==Physiology== | ||
Clinical isolates of grow consistently at temperatures up to {{convert|35|C|F}}.<ref name=rippon1988/> In contrast, environmental isolates of ''F. pedrosoi'' exhibit growth consistently up to 35°C, and irregularly up to {{convert|37|C|F}}<ref name=gugnani1989 /> Physiological studies have shown the degradation of [[urea]] and [[tyrosine]], and the lack of growth on the proteins [[gelatin]], [[casein]] and the [[purine]]s [[xanthine]] and [[hypoxanthine]].<ref name=gugnani1989 /> Likewise, [[lipase]] activity was demonstrated, but [[phospholipase]], [[collagenase]] and [[amylase]] were not expressed.<ref name=gugnani1989 /> | Clinical isolates of grow consistently at temperatures up to {{convert|35|C|F}}.<ref name=rippon1988>{{cite book |last=Rippon |first=John Willard |title=Medical Mycology: The Pathogenic Fungi and the Pathogenic Actinomycetes |year=1988 |publisher=Saunders |location=Philadelphia, PA |isbn=0721624448 |edition=3rd}}</ref> In contrast, environmental isolates of ''F. pedrosoi'' exhibit growth consistently up to 35°C, and irregularly up to {{convert|37|C|F}}<ref name=gugnani1989>{{cite journal |last1=Gugnani |first1=H.C. |last2=Okeke |first2=C.N. |title=Physiological characteristics of environmental isolates of pathogenic dematiaceous fungi |journal=Mycoses |year=2009 |volume=32 |issue=2 |pages=78–83 |doi=10.1111/j.1439-0507.1989.tb02206.x|pmid=2710157 }}</ref> Physiological studies have shown the degradation of [[urea]] and [[tyrosine]], and the lack of growth on the proteins [[gelatin]], [[casein]] and the [[purine]]s [[xanthine]] and [[hypoxanthine]].<ref name=gugnani1989>{{cite journal |last1=Gugnani |first1=H.C. |last2=Okeke |first2=C.N. |title=Physiological characteristics of environmental isolates of pathogenic dematiaceous fungi |journal=Mycoses |year=2009 |volume=32 |issue=2 |pages=78–83 |doi=10.1111/j.1439-0507.1989.tb02206.x|pmid=2710157 }}</ref> Likewise, [[lipase]] activity was demonstrated, but [[phospholipase]], [[collagenase]] and [[amylase]] were not expressed.<ref name=gugnani1989>{{cite journal |last1=Gugnani |first1=H.C. |last2=Okeke |first2=C.N. |title=Physiological characteristics of environmental isolates of pathogenic dematiaceous fungi |journal=Mycoses |year=2009 |volume=32 |issue=2 |pages=78–83 |doi=10.1111/j.1439-0507.1989.tb02206.x|pmid=2710157 }}</ref> | ||
==Human disease== | ==Human disease== | ||
''Fonsecaea pedrosoi'' is one of several main causative agents of human [[chromoblastomycosis]], a [[chronic (medicine)|chronic]] fungal infection localized to skin and [[subcutaneous tissue]].<ref name=Alviano2004/><ref name=Yang2012/><ref name=DebRoy2013 /> The disease was first described by Alexandrino Pedroso in 1911.<ref name=DebRoy2013/> The fungus infects the host through the traumatic implantation of sexual spores known as [[conidia]] or hyphal fragments.<ref name=Alviano2004/> Once introduced in the subcutaneous tissues, the [[propagule]]s germinate to establish an invasive [[mycelium]] associated with [[sclerosis (medicine)|sclerotic]] cells.<ref name=Alviano2004/> This proliferation manifests as a well-defined, chronically progressive, crusted [[ulcer (dermatology)|ulceration]] of the skin known as [[chromoblastomycosis]].<ref name=Nimrichter2005/><ref name=DebRoy2013/><ref name=Kondo2005/> Clinically it is often misdiagnosed as [[squamous cell carcinoma]].<ref name=DebRoy2013/> | ''Fonsecaea pedrosoi'' is one of several main causative agents of human [[chromoblastomycosis]], a [[chronic (medicine)|chronic]] fungal infection localized to skin and [[subcutaneous tissue]].<ref name=Alviano2004>{{cite journal|last=Alviano|first=D|author2=Franzen, A |author3=Travassos, L |author4=Holandino, C |author5=Rozental, S |author6=Ejzemberg, R |author7=Rodrigues, M |title=Melanin from ''Fonsecaea pedrosoi'' induces production of human antifungal antibodies and enhances the antimicrobial efficacy of phagocytes |journal=Infection and Immunity |year=2004 |volume=72 |issue=1 |pages=229–237 |doi=10.1128/IAI.72.1.229-237.2004|pmid=14688100}}</ref><ref name=Yang2012>{{cite journal|last=Yang|first=Y|author2=Yongxuan, H |author3=Zhang, J |author4= Li, X |author5=Lu, C |author6= Xi, L |title= A refractory case of chromoblastomycosis due to ''Fonsecaea monophora'' with improvement by photodynamic therapy|journal = Medical Mycology 2012 |volume=50|issue=1|pages=649–653|doi=10.3109/13693786.2012.655258 |year=2012|last7=Xi|first7=Liyan}}</ref><ref name=DebRoy2013 /> The disease was first described by Alexandrino Pedroso in 1911.<ref name=DebRoy2013>{{cite journal |last=Deb Roy |first=A |author2=Das, D |author3=Deka, M |title=Chromoblastomycosis – A clinical mimic of squamous carcinoma |journal=Mycopathologia |year=2013 |volume=6 |issue=9 |pages=458–460 |doi=10.4066/AMJ.2013.1806}}</ref> The fungus infects the host through the traumatic implantation of sexual spores known as [[conidia]] or hyphal fragments.<ref name=Alviano2004>{{cite journal|last=Alviano|first=D|author2=Franzen, A |author3=Travassos, L |author4=Holandino, C |author5=Rozental, S |author6=Ejzemberg, R |author7=Rodrigues, M |title=Melanin from ''Fonsecaea pedrosoi'' induces production of human antifungal antibodies and enhances the antimicrobial efficacy of phagocytes |journal=Infection and Immunity |year=2004 |volume=72 |issue=1 |pages=229–237 |doi=10.1128/IAI.72.1.229-237.2004|pmid=14688100}}</ref> Once introduced in the subcutaneous tissues, the [[propagule]]s germinate to establish an invasive [[mycelium]] associated with [[sclerosis (medicine)|sclerotic]] cells.<ref name=Alviano2004>{{cite journal|last=Alviano|first=D|author2=Franzen, A |author3=Travassos, L |author4=Holandino, C |author5=Rozental, S |author6=Ejzemberg, R |author7=Rodrigues, M |title=Melanin from ''Fonsecaea pedrosoi'' induces production of human antifungal antibodies and enhances the antimicrobial efficacy of phagocytes |journal=Infection and Immunity |year=2004 |volume=72 |issue=1 |pages=229–237 |doi=10.1128/IAI.72.1.229-237.2004|pmid=14688100}}</ref> This proliferation manifests as a well-defined, chronically progressive, crusted [[ulcer (dermatology)|ulceration]] of the skin known as [[chromoblastomycosis]].<ref name=Nimrichter2005>{{cite journal|last=Nimrichter|first=L|author2=Cerqueira, M |author3=Leitao, E |author4= Miranda, K |author5=Nakayasu, E |author6= Almeida, S |author7=Rodrigues, M |title=Structure, cellular distribution, antigenicity, and biological functions of ''Fonsecaea pedrosoi'' ceramide monohexosides |journal=Infection and Immunity |year=2005 |volume=73 |issue=12 |pages=7860–7868 |doi=10.1128/IAI.73.12.7860-7868.2005|pmid=16299276}}</ref><ref name=DebRoy2013>{{cite journal |last=Deb Roy |first=A |author2=Das, D |author3=Deka, M |title=Chromoblastomycosis – A clinical mimic of squamous carcinoma |journal=Mycopathologia |year=2013 |volume=6 |issue=9 |pages=458–460 |doi=10.4066/AMJ.2013.1806}}</ref><ref name=Kondo2005>{{cite journal|last=Kondo|first=M|author2=Hiruma, M |author3=Nishioka, Y |author4=Mochida, K |author5=Ikeda, S |author6=Ogawa, H |title=A case of chromomycosis caused by ''Fonsecaea pedrosoi'' and a review of reported cases of dematiaceous fungal infection in Japan |journal=Mycoses |year=2005 |volume=48 |issue=1 |pages=221–225 |doi=10.1111/j.1439-0507.2005.01089.x}}</ref> Clinically it is often misdiagnosed as [[squamous cell carcinoma]].<ref name=DebRoy2013>{{cite journal |last=Deb Roy |first=A |author2=Das, D |author3=Deka, M |title=Chromoblastomycosis – A clinical mimic of squamous carcinoma |journal=Mycopathologia |year=2013 |volume=6 |issue=9 |pages=458–460 |doi=10.4066/AMJ.2013.1806}}</ref> | ||
===Histology=== | ===Histology=== | ||
The disease is characterized by the appearance of spherical, brownish yellow cells with thick, darkly pigmented walls.<ref name=Alviano1992/> The presence of the agent is associated with host cell proliferation and enlargement known as [[hyperplasia]] localized to the [[stratified squamous epithelium]] and the formation of mycotic [[granuloma]]s.<ref name=DebRoy2013/> Sclerotic bodies are present both extracellularly and intracellularly throughout the affected tissue and are a defining feature of chromoblastomycosis.<ref name=DebRoy2013/><ref name=Kondo2005/> The melanin content of sclerotic bodies may be important in the establishment of host immune responses.<ref name=Alviano2004/> | The disease is characterized by the appearance of spherical, brownish yellow cells with thick, darkly pigmented walls.<ref name=Alviano1992>{{cite journal |last=Alviano |first=C |author2=Farbiarz, S |author3=Travassos, L |author4=Angluster, J |author5=De Souza, W |title=Effect of environmental factors on ''Fonsecaea pedrosoi'' morphogenesis with emphasis on sclerotic cells induced by propranolol |journal= Mycopathologia |year=1992 |volume=119 |issue=1 |pages=17–23 |doi=10.1007/BF00492225|pmid=1406903 }}</ref> The presence of the agent is associated with host cell proliferation and enlargement known as [[hyperplasia]] localized to the [[stratified squamous epithelium]] and the formation of mycotic [[granuloma]]s.<ref name=DebRoy2013>{{cite journal |last=Deb Roy |first=A |author2=Das, D |author3=Deka, M |title=Chromoblastomycosis – A clinical mimic of squamous carcinoma |journal=Mycopathologia |year=2013 |volume=6 |issue=9 |pages=458–460 |doi=10.4066/AMJ.2013.1806}}</ref> Sclerotic bodies are present both extracellularly and intracellularly throughout the affected tissue and are a defining feature of chromoblastomycosis.<ref name=DebRoy2013>{{cite journal |last=Deb Roy |first=A |author2=Das, D |author3=Deka, M |title=Chromoblastomycosis – A clinical mimic of squamous carcinoma |journal=Mycopathologia |year=2013 |volume=6 |issue=9 |pages=458–460 |doi=10.4066/AMJ.2013.1806}}</ref><ref name=Kondo2005>{{cite journal|last=Kondo|first=M|author2=Hiruma, M |author3=Nishioka, Y |author4=Mochida, K |author5=Ikeda, S |author6=Ogawa, H |title=A case of chromomycosis caused by ''Fonsecaea pedrosoi'' and a review of reported cases of dematiaceous fungal infection in Japan |journal=Mycoses |year=2005 |volume=48 |issue=1 |pages=221–225 |doi=10.1111/j.1439-0507.2005.01089.x}}</ref> The melanin content of sclerotic bodies may be important in the establishment of host immune responses.<ref name=Alviano2004>{{cite journal|last=Alviano|first=D|author2=Franzen, A |author3=Travassos, L |author4=Holandino, C |author5=Rozental, S |author6=Ejzemberg, R |author7=Rodrigues, M |title=Melanin from ''Fonsecaea pedrosoi'' induces production of human antifungal antibodies and enhances the antimicrobial efficacy of phagocytes |journal=Infection and Immunity |year=2004 |volume=72 |issue=1 |pages=229–237 |doi=10.1128/IAI.72.1.229-237.2004|pmid=14688100}}</ref> | ||
===Risk factors for infection=== | ===Risk factors for infection=== | ||
Farmers in Central and South America are most susceptible to chromoblastomycosis due to ''F. pedrosoi''.<ref name=Kondo2005/><ref name=Nimrichter2005/> Infection often occurs in the upper body and legs of agricultural laborers since these areas are more prone to exposure to infected soil, plant debris or other fomites.<ref name=Nimrichter2005/> The sex ratio of disease is globally variable. In Brazil, the agent has shown a 4:1 proclivity for men, likely as a function of exposure differences relating to work and lifestyle,<ref name=Kondo2005/> while Japanese infections have shown evenly distributed infection rates between the sexes.<ref name=Kondo2005/> | Farmers in Central and South America are most susceptible to chromoblastomycosis due to ''F. pedrosoi''.<ref name=Kondo2005>{{cite journal|last=Kondo|first=M|author2=Hiruma, M |author3=Nishioka, Y |author4=Mochida, K |author5=Ikeda, S |author6=Ogawa, H |title=A case of chromomycosis caused by ''Fonsecaea pedrosoi'' and a review of reported cases of dematiaceous fungal infection in Japan |journal=Mycoses |year=2005 |volume=48 |issue=1 |pages=221–225 |doi=10.1111/j.1439-0507.2005.01089.x}}</ref><ref name=Nimrichter2005>{{cite journal|last=Nimrichter|first=L|author2=Cerqueira, M |author3=Leitao, E |author4= Miranda, K |author5=Nakayasu, E |author6= Almeida, S |author7=Rodrigues, M |title=Structure, cellular distribution, antigenicity, and biological functions of ''Fonsecaea pedrosoi'' ceramide monohexosides |journal=Infection and Immunity |year=2005 |volume=73 |issue=12 |pages=7860–7868 |doi=10.1128/IAI.73.12.7860-7868.2005|pmid=16299276}}</ref> Infection often occurs in the upper body and legs of agricultural laborers since these areas are more prone to exposure to infected soil, plant debris or other fomites.<ref name=Nimrichter2005>{{cite journal|last=Nimrichter|first=L|author2=Cerqueira, M |author3=Leitao, E |author4= Miranda, K |author5=Nakayasu, E |author6= Almeida, S |author7=Rodrigues, M |title=Structure, cellular distribution, antigenicity, and biological functions of ''Fonsecaea pedrosoi'' ceramide monohexosides |journal=Infection and Immunity |year=2005 |volume=73 |issue=12 |pages=7860–7868 |doi=10.1128/IAI.73.12.7860-7868.2005|pmid=16299276}}</ref> The sex ratio of disease is globally variable. In Brazil, the agent has shown a 4:1 proclivity for men, likely as a function of exposure differences relating to work and lifestyle,<ref name=Kondo2005>{{cite journal|last=Kondo|first=M|author2=Hiruma, M |author3=Nishioka, Y |author4=Mochida, K |author5=Ikeda, S |author6=Ogawa, H |title=A case of chromomycosis caused by ''Fonsecaea pedrosoi'' and a review of reported cases of dematiaceous fungal infection in Japan |journal=Mycoses |year=2005 |volume=48 |issue=1 |pages=221–225 |doi=10.1111/j.1439-0507.2005.01089.x}}</ref> while Japanese infections have shown evenly distributed infection rates between the sexes.<ref name=Kondo2005>{{cite journal|last=Kondo|first=M|author2=Hiruma, M |author3=Nishioka, Y |author4=Mochida, K |author5=Ikeda, S |author6=Ogawa, H |title=A case of chromomycosis caused by ''Fonsecaea pedrosoi'' and a review of reported cases of dematiaceous fungal infection in Japan |journal=Mycoses |year=2005 |volume=48 |issue=1 |pages=221–225 |doi=10.1111/j.1439-0507.2005.01089.x}}</ref> | ||
===Treatment=== | ===Treatment=== | ||
Infections by ''F. pedrosoi'' are more difficult to treat than those of ''F. monophora''.<ref name=Yang2012/> In severe cases, treatment is quite complex and involves a combination of antifungal drug therapy and surgical excision.<ref name=Nimrichter2005/> Antifungal agents like [[itraconazole]] and [[terbinafine]] are commonly used. Surgery is often used to treat small, localized infections,<ref name=DebRoy2013/> although [[cryotherapy]] has been suggested an alternative approach.<ref name=Nimrichter2005/> Topical application of [[amphotericin B]] followed by long-term administration of oral antifungal therapy has been shown to be effective in the treatment of corneal chromoblastomycosis from ''F. pedrosoi''.<ref name=Sangwan2013/> The diagnosis and treatment of chromoblastomycosis by ''F. pedrosoi'' remains clinically challenging due to the relative rarity of the disease, its slow, chronic nature, the absence of clinical features readily differentiating it from other more common diseases such as squamous cell carcinoma, the restricted nature of therapies, and the lack of literature.<ref name=Kondo2005/><ref name=Yang2012/> | Infections by ''F. pedrosoi'' are more difficult to treat than those of ''F. monophora''.<ref name=Yang2012>{{cite journal|last=Yang|first=Y|author2=Yongxuan, H |author3=Zhang, J |author4= Li, X |author5=Lu, C |author6= Xi, L |title= A refractory case of chromoblastomycosis due to ''Fonsecaea monophora'' with improvement by photodynamic therapy|journal = Medical Mycology 2012 |volume=50|issue=1|pages=649–653|doi=10.3109/13693786.2012.655258 |year=2012|last7=Xi|first7=Liyan}}</ref> In severe cases, treatment is quite complex and involves a combination of antifungal drug therapy and surgical excision.<ref name=Nimrichter2005>{{cite journal|last=Nimrichter|first=L|author2=Cerqueira, M |author3=Leitao, E |author4= Miranda, K |author5=Nakayasu, E |author6= Almeida, S |author7=Rodrigues, M |title=Structure, cellular distribution, antigenicity, and biological functions of ''Fonsecaea pedrosoi'' ceramide monohexosides |journal=Infection and Immunity |year=2005 |volume=73 |issue=12 |pages=7860–7868 |doi=10.1128/IAI.73.12.7860-7868.2005|pmid=16299276}}</ref> Antifungal agents like [[itraconazole]] and [[terbinafine]] are commonly used. Surgery is often used to treat small, localized infections,<ref name=DebRoy2013>{{cite journal |last=Deb Roy |first=A |author2=Das, D |author3=Deka, M |title=Chromoblastomycosis – A clinical mimic of squamous carcinoma |journal=Mycopathologia |year=2013 |volume=6 |issue=9 |pages=458–460 |doi=10.4066/AMJ.2013.1806}}</ref> although [[cryotherapy]] has been suggested an alternative approach.<ref name=Nimrichter2005>{{cite journal|last=Nimrichter|first=L|author2=Cerqueira, M |author3=Leitao, E |author4= Miranda, K |author5=Nakayasu, E |author6= Almeida, S |author7=Rodrigues, M |title=Structure, cellular distribution, antigenicity, and biological functions of ''Fonsecaea pedrosoi'' ceramide monohexosides |journal=Infection and Immunity |year=2005 |volume=73 |issue=12 |pages=7860–7868 |doi=10.1128/IAI.73.12.7860-7868.2005|pmid=16299276}}</ref> Topical application of [[amphotericin B]] followed by long-term administration of oral antifungal therapy has been shown to be effective in the treatment of corneal chromoblastomycosis from ''F. pedrosoi''.<ref name=Sangwan2013>{{cite journal |last1=Sangwan |first1=Jyoti |last2=Jachuck|first2=SJ |title=''Fonsecaea Pedrosoi'': A rare etiology in fungal keratitis |journal=Journal of Clinical and Diagnostic Research |year=2013 |doi=10.7860/JCDR/2013/6627.3491}}</ref> The diagnosis and treatment of chromoblastomycosis by ''F. pedrosoi'' remains clinically challenging due to the relative rarity of the disease, its slow, chronic nature, the absence of clinical features readily differentiating it from other more common diseases such as squamous cell carcinoma, the restricted nature of therapies, and the lack of literature.<ref name=Kondo2005>{{cite journal|last=Kondo|first=M|author2=Hiruma, M |author3=Nishioka, Y |author4=Mochida, K |author5=Ikeda, S |author6=Ogawa, H |title=A case of chromomycosis caused by ''Fonsecaea pedrosoi'' and a review of reported cases of dematiaceous fungal infection in Japan |journal=Mycoses |year=2005 |volume=48 |issue=1 |pages=221–225 |doi=10.1111/j.1439-0507.2005.01089.x}}</ref><ref name=Yang2012>{{cite journal|last=Yang|first=Y|author2=Yongxuan, H |author3=Zhang, J |author4= Li, X |author5=Lu, C |author6= Xi, L |title= A refractory case of chromoblastomycosis due to ''Fonsecaea monophora'' with improvement by photodynamic therapy|journal = Medical Mycology 2012 |volume=50|issue=1|pages=649–653|doi=10.3109/13693786.2012.655258 |year=2012|last7=Xi|first7=Liyan}}</ref> | ||
==References== | ==References== | ||
Latest revision as of 13:48, 6 August 2015
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 Conidiophores of Fonsecaea pedrosoi from slide culture on Modified Leonian's agar
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This page is about microbiologic aspects of the organism(s). For clinical aspects of the disease, see Chromoblastomycosis.
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Chromoblastomycosis Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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Fonsecaea pedrosoi On the Web |
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American Roentgen Ray Society Images of Fonsecaea pedrosoi |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Fonsecaea pedrosoi is a fungal species in the family Herpotrichiellaceae, and the major causative agent of chromoblastomycosis.[1] This species is commonly found in tropical and sub-tropical regions where it grows as a soil saprotroph.[2] Farming activities in the endemic zone are a risk factor for the development of chromoblastomycosis.[2][3]
Classification
Fonsecaea is a genus of ascomycetous fungi affiliated with the family Herpotrichiellaceae.[4] The genus comprises three sibling species, all with pathogenic potential: F. pedrosoi, F. monophora and F. nubica.[4]
Ecology and distribution
Fonsecaea pedrosoi occurs in soil and on plants and trees where it grows as a saprotroph.[4][3][5] It is found predominantly in tropical regions especially South- and Central America.[4][6] All three recognized species of Fonsecaea exhibit geographically patterned genetic variation. The closely related species F. monophora and F. nubica are distributed worldwide and show the greater population-level genetic diversity than the geographically restricted F. pedrosoi.[4] Environmental surveys have documented the recovery of F. pedrosoi on rotting wood of the Cambara tree, (Gochnatia polymorpha) from the Brazilian Corporation of Agricultural Research forest in Colombo, Paraná, Brazil.[7] It has been also isolated from living trees, stumps, woodpiles and fence posts in central Nigeria.[8]
Physiology
Clinical isolates of grow consistently at temperatures up to 35 °C (95 °F).[9] In contrast, environmental isolates of F. pedrosoi exhibit growth consistently up to 35°C, and irregularly up to 37 °C (98.6 °F)[10] Physiological studies have shown the degradation of urea and tyrosine, and the lack of growth on the proteins gelatin, casein and the purines xanthine and hypoxanthine.[10] Likewise, lipase activity was demonstrated, but phospholipase, collagenase and amylase were not expressed.[10]
Human disease
Fonsecaea pedrosoi is one of several main causative agents of human chromoblastomycosis, a chronic fungal infection localized to skin and subcutaneous tissue.[1][6][2] The disease was first described by Alexandrino Pedroso in 1911.[2] The fungus infects the host through the traumatic implantation of sexual spores known as conidia or hyphal fragments.[1] Once introduced in the subcutaneous tissues, the propagules germinate to establish an invasive mycelium associated with sclerotic cells.[1] This proliferation manifests as a well-defined, chronically progressive, crusted ulceration of the skin known as chromoblastomycosis.[3][2][11] Clinically it is often misdiagnosed as squamous cell carcinoma.[2]
Histology
The disease is characterized by the appearance of spherical, brownish yellow cells with thick, darkly pigmented walls.[12] The presence of the agent is associated with host cell proliferation and enlargement known as hyperplasia localized to the stratified squamous epithelium and the formation of mycotic granulomas.[2] Sclerotic bodies are present both extracellularly and intracellularly throughout the affected tissue and are a defining feature of chromoblastomycosis.[2][11] The melanin content of sclerotic bodies may be important in the establishment of host immune responses.[1]
Risk factors for infection
Farmers in Central and South America are most susceptible to chromoblastomycosis due to F. pedrosoi.[11][3] Infection often occurs in the upper body and legs of agricultural laborers since these areas are more prone to exposure to infected soil, plant debris or other fomites.[3] The sex ratio of disease is globally variable. In Brazil, the agent has shown a 4:1 proclivity for men, likely as a function of exposure differences relating to work and lifestyle,[11] while Japanese infections have shown evenly distributed infection rates between the sexes.[11]
Treatment
Infections by F. pedrosoi are more difficult to treat than those of F. monophora.[6] In severe cases, treatment is quite complex and involves a combination of antifungal drug therapy and surgical excision.[3] Antifungal agents like itraconazole and terbinafine are commonly used. Surgery is often used to treat small, localized infections,[2] although cryotherapy has been suggested an alternative approach.[3] Topical application of amphotericin B followed by long-term administration of oral antifungal therapy has been shown to be effective in the treatment of corneal chromoblastomycosis from F. pedrosoi.[5] The diagnosis and treatment of chromoblastomycosis by F. pedrosoi remains clinically challenging due to the relative rarity of the disease, its slow, chronic nature, the absence of clinical features readily differentiating it from other more common diseases such as squamous cell carcinoma, the restricted nature of therapies, and the lack of literature.[11][6]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Alviano, D; Franzen, A; Travassos, L; Holandino, C; Rozental, S; Ejzemberg, R; Rodrigues, M (2004). "Melanin from Fonsecaea pedrosoi induces production of human antifungal antibodies and enhances the antimicrobial efficacy of phagocytes". Infection and Immunity. 72 (1): 229–237. doi:10.1128/IAI.72.1.229-237.2004. PMID 14688100.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Deb Roy, A; Das, D; Deka, M (2013). "Chromoblastomycosis – A clinical mimic of squamous carcinoma". Mycopathologia. 6 (9): 458–460. doi:10.4066/AMJ.2013.1806.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Nimrichter, L; Cerqueira, M; Leitao, E; Miranda, K; Nakayasu, E; Almeida, S; Rodrigues, M (2005). "Structure, cellular distribution, antigenicity, and biological functions of Fonsecaea pedrosoi ceramide monohexosides". Infection and Immunity. 73 (12): 7860–7868. doi:10.1128/IAI.73.12.7860-7868.2005. PMID 16299276.
- ↑ 4.0 4.1 4.2 4.3 4.4 Najafzadeh, M; Sun, J; Vincete, V; Klaassen, C; Bonifaz, A; Gerrits van den Ende, A; Sybren de Hoog, G (2011). "Molecular epidemiology of Fonsecaea species". Emerging Infectious Diseases. 17 (3): 464–69. doi:10.3201/eid1703.100555.
- ↑ 5.0 5.1 Sangwan, Jyoti; Jachuck, SJ (2013). "Fonsecaea Pedrosoi: A rare etiology in fungal keratitis". Journal of Clinical and Diagnostic Research. doi:10.7860/JCDR/2013/6627.3491.
- ↑ 6.0 6.1 6.2 6.3 Yang, Y; Yongxuan, H; Zhang, J; Li, X; Lu, C; Xi, L; Xi, Liyan (2012). "A refractory case of chromoblastomycosis due to Fonsecaea monophora with improvement by photodynamic therapy". Medical Mycology 2012. 50 (1): 649–653. doi:10.3109/13693786.2012.655258.
- ↑ Vicente, Vânia Aparecida; Angelis, Derlene Attili de; Queiróz-Telles Filho, Flávio; Pizzirani-Kleiner, Aline Aparecida (2001). "Isolation of herpotrichiellacious fungi from the environment". Brazilian Journal of Microbiology. 32 (1): 47–51. doi:10.1590/S1517-83822001000100011.
- ↑ Okeke, CN; Gugnani, HC (1986). "Studies on pathogenic dematiaceous fungi. 1. Isolation from natural sources". Mycopathologia. 94 (1): 19–25. doi:10.1007/bf00437257. PMID 3724831.
- ↑ Rippon, John Willard (1988). Medical Mycology: The Pathogenic Fungi and the Pathogenic Actinomycetes (3rd ed.). Philadelphia, PA: Saunders. ISBN 0721624448.
- ↑ 10.0 10.1 10.2 Gugnani, H.C.; Okeke, C.N. (2009). "Physiological characteristics of environmental isolates of pathogenic dematiaceous fungi". Mycoses. 32 (2): 78–83. doi:10.1111/j.1439-0507.1989.tb02206.x. PMID 2710157.
- ↑ 11.0 11.1 11.2 11.3 11.4 11.5 Kondo, M; Hiruma, M; Nishioka, Y; Mochida, K; Ikeda, S; Ogawa, H (2005). "A case of chromomycosis caused by Fonsecaea pedrosoi and a review of reported cases of dematiaceous fungal infection in Japan". Mycoses. 48 (1): 221–225. doi:10.1111/j.1439-0507.2005.01089.x.
- ↑ Alviano, C; Farbiarz, S; Travassos, L; Angluster, J; De Souza, W (1992). "Effect of environmental factors on Fonsecaea pedrosoi morphogenesis with emphasis on sclerotic cells induced by propranolol". Mycopathologia. 119 (1): 17–23. doi:10.1007/BF00492225. PMID 1406903.