Molecular epidemiology of Fonsecaea species

Abstract

To assess population diversities among 81 strains of fungi in the genus Fonsecaea that had been identified down to species level, we applied amplified fragment-length polymorphism (AFLP) technology and sequenced the internal transcribed spacer regions and the partial cell division cycle, beta-tubulin, and actin genes. Many species of the genus Fonsecaea cause human chromoblastomycosis. Strains originated from a global sampling of clinical and environmental sources in the Western Hemisphere, Asia, Africa, and Europe. According to AFLP fingerprinting, Fonsecaea isolates clustered in 5 groups corresponding with F. pedrosoi, F. monophora, and F. nubica: the latter 2 species each comprised 2 groups, and F. pedrosoi appeared to be of monophyletic origin. F. pedrosoi was found nearly exclusively in Central and South America. F. monophora and F. nubica were distributed worldwide, but both showed substantial geographic structuring. Clinical cases outside areas where Fonsecaea is endemic were probably distributed by human migration.

Figure

Geographic distribution of Fonsecaea spp. samples analyzed by using amplified fragment-length polymorphism. Light pink shading indicates zone of clinical Fonsecaea spp. endemicity, according to published case reports. Sizes of pies and numbers reported within the pies denote the number of strains examined; colors represent Fonsecaea spp. populations: orange, F. nubica population 1; fuchsia, F. nubica population 2; dark blue, F. monophora population 3; light blue, F. monophora population 4; yellow, F. pedrosoi population 5.

Figure A1

Clustering of amplified fragment-length polymorphism banding pattern of isolates of Fonsecaea spp. analyzed by using unweighted pair group method with arithmetic means. Red bars indicate clonal dispersal. Clusters 1 and 2 are F. nubica, clusters 3 and 4 are F. monophora, and cluster 5 is F. pedrosoi.