Genetic diversity of Histoplasma capsulatum strains isolated from soil, animals, and clinical specimens in Rio de Janeiro State, Brazil, by a PCR-based random amplified polymorphic DNA

Little is known about the genetic strain diversity and geographical range o f Histoplasma capsulatum isolated in Rio de Janeiro State, Brazil. We chara cterized 13 environmental, 7 animal, and 28 clinical H. capsulatum isolates by using a PCR-based random amplified polymorphic DNA (RA-PD) assay. DNA f ingerprinting of these soil, animal, and clinical specimens was performed w ith four primers (1253, 1281, D-9355, and D-10513) and generated amplicons with considerable polymorphism. Although all of the isolates exhibited more than 80% genetic relatedness, they could be clustered into four to six gen otypes for each primer. The RAPD profiles of H. capsulatum isolated from Ri o de Janeiro State could be distinguished from those of the U.S. strains in cluded in this study (Downs, G222B, G-186B, and FLS1) by showing less than 70% similarity to each primer. The genetic polymorphisms between H. capsula tum strains isolated from animals and soil obtained in the same geographic areas were 100% similar, suggesting that an environmental microniche could be acting as a source of infection for animals and the local human populati on.