Genetic diversity and population structure of clinical Sporothrix strains in South Africa.

Fuchs, T.*, Visagie, C. M., Wingfield, B. D., Wingfield, M. J.

Department of Biochemistry, Genetics & Microbiology; Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa

Sporotrichosis is a fungal disease affecting humans and mammals, caused by Sporothrix species (Ascomycota). The disease has growing public health implications worldwide. An outbreak of sporotrichosis in South Africa involving more than 3200 gold miners between 1938 and 1947 represents one of the world’s most notable incidents of the disease. Since this outbreak, sporadic cases have been reported in the country. Sporothrix schenckii, the type species of the genus, is believed to be the major disease agent in South Africa. However, research on South African clinical strains is limited, which is especially relevant given the current taxonomy of the genus that resolves pathogenic species in a clade separate from the environmental species. The recent development of microsatellite and mating type markers for the Sporothrix pathogenic clade has provided an opportunity to investigate clinical Sporothrix strains from South Africa. To achieve this goal, a large collection of these strains was genotyped, to consider their population structure and genetic diversity. Both MAT idiomorphs were found in the population, although these were skewed towards the MAT1-2 idiomorph. The microsatellite markers provided insights into the genetic diversity of clinical Sporothrix isolates and allowed comparisons with strains from other parts of the world. The results have provided new knowledge regarding the diversity of S. schenckii and the epidemiology of the pathogen in South Africa.

Keywords: Sporothrix, sporothricosis, microsatellite, diversity, population