Molecular diversity ofFonsecaea(Chaetothyriales) causing chromoblastomycosis in southern China

Abstract

Chromoblastomycosis is a chronic, cutaneous and subcutaneous infection caused by members of the order Chaetothyriales and commonly found in China. Among the etiologic agents, members of the genus Cladophialophora are predominant in northern China. Alternatively, Fonsecaea spp. are particularly common in southern China. However, the identification of Fonsecaea isolates recovered in China is difficult due to the fact that different species lack distinctive morphological characters. Therefore, the identification of 24 Fonsecaea isolates from symptomatic patients were re-evaluated by using morphology, ITS rDNA sequence diversity and partly through the use of randomly amplified polymorphic DNA (RAPD) typing. Twenty strains, including a morphological mutant were found to be Fonsecaea monophora, while four strains corresponded to F. pedrosoi. We have demonstrated that Fonsecaea monophora is the predominant etiologic agent of chromoblastomycosis in southern China and populations showed marked geographic structuring.

Chromoblastomycosis

“…The cases were distributed all over the country, covering more than 21 provinces. The highest prevalence rates were found for Guangdong Province (84/196) and Shandong Province (38/196) based on literature published from 1990 to 2015 (136). There may be areas of hyperendemicity; for example, in a study of CBM conducted by Dai et al in Zhangqiu City, Shandong Province, up to 300 cases of CBM were found in 1998 (135).…”

“…Although the age range extended from 9 years to 90 years, children were rarely affected (1.2%) (109). In China, the majority of CBM patients are males (6.7:1), with a mean age of 54.75 years (range, 10 to 81 years) (136). Although CBM in children is infrequent, from 1992 to 2004, 22 cases (aged 2 to 19 years) of C. carrionii infections were reported in the semiarid state of Falcón, Venezuela, (88).…”

Fonsecaea pugnacius, a Novel Agent of Disseminated Chromoblastomycosis

“…Fonsecaea infections are relatively frequent in the humid climate zones of Brazil and southern China (7,20). The state of Maranhão in northeast Brazil is a region of chromoblastomycosis hyperendemicity.…”

“…Although traumatic inoculation from thorns or wood splinters is a likely source of onset of the disease (4), the infection process and route of dispersal have been insufficiently clarified (5,6), particularly in disseminated cases. Several members of the black yeast order Chaetothyriales in the genera Cladophialophora, Exophiala, Fonsecaea, Phialophora, and Rhinocladiella are able to cause chromoblastomycosis or chromoblastomycosis-like infections, of which infections with C. carrionii and F. pedrosoi are the most frequent (1,7,8).…”

Murine Model of a Disseminated Infection by the Novel Fungus Fonsecaea monophora and Successful Treatment with Posaconazole

“…The dematiaceous fungus Fonsecaea monophora is a causal agent of cerebral phaeohyphomycosis (10) and chromoblastomycosis (11)(12)(13). On the basis of molecular studies (3,7), this fungus has recently been segregated from Fonsecaea pedrosoi, a traditionally well-known pathogen.…”