Molecular epidemiology of Colombian Histoplasma capsulatum isolates shows their polyphyletic behavior and point out raw chicken manure as one of the infections sources

The thermally dimorphic fungus Histoplasma capsulatum is the causative agent of histoplasmosis, which is the most prevalent endemic mycosis in America. The replacement of organic matter in agro-ecosystems is necessary in the tropics, and the use of organic fertilizers has increased. Cases and outbreaks due to the presence of the fungus in these components have been reported. In Colombia, chicken manure is the most common raw material in the organic fertilizers production. In this work, we reached the isolation of the fungus from a chicken manure. Then, we were able to compare genetically 3 environmental isolates with 42 Colombian human clinical isolates. The genetic comparison showed the environmental isolates grouping together with the clinical isolates. This result suggests chicken manure as one of the infection source with H. capsulatum. Also, the phylogenetic analysis using another H. capsulatum isolates from databases showed that the Colombian isolates widely distributed in the relation tree. This result pointed out the great genetic diversity among H. capsulatum Colombian population.