[Investigation of Cryptococcus neoformans Mating Capability in Peloidotherapy Muds]

The human pathogen Cryptococcus neoformans has been isolated from a variety of environmental sources, including avian excreta, soil, trees, and decaying wood. In addition to the biological characteristics of the yeast, the structure and properties of the external environment play a pivotal role in the process of environmental colonization. Peloidotherapy has been used since ancient times in the Aegean Region (near Denizli, Türkiye) as a treatment or supportive therapy for pathological disorders and musculoskeletal conditions. This therapy involves either immersing patients in natural pools or rehydrating dried mud and applying it directly to the body. Notably, the organic content of these peloids is quite low. Additionally, commercially packaged peloidotherapy muds undergo high-temperature treatments, which alter their physicochemical properties. While it is possible that sexual reproduction might occur during environmental colonization by cryptococcal species, even in environments with low organic content, there is currently insufficient data to confirm this phenomenon in peloids. The aim of this study was to investigate the sexual reproduction of C.neoformans in peloids with low organic content, which are used in peloidotherapy practices in our country.The aim of this study was to investigate the sexual reproduction of C.neoformans in muds with poor organic content used in peloidotherapy in our country. In this study, commercially packaged peloid samples (1 g/L, filtered in distilled water) from three active sources in the Denizli Basin -Sarayköy, Gölemezli, and Karahayıt- were used to prepare media with varying pH levels, supplemented with 3 g/L CaCO3 and 1 g/L agar. Two reference strains, C.neoformans KN99 Aa and KN99 Aα, were tested for their ability to mate on these media. Over the course of a month, the plates were periodically examined for sexual structures, including filaments, hyphae, clamp connections, basidia and basidiospores. Sexual structures were observed in two of the three samples, indicating that, despite their low organic content, reusable and commercially available peloids can support C.neoformans, particularly under conditions of immunosuppression. Moreover, the low organic content and the mineral variability of peloids across regions provide a unique environment for studying factors that influence the natural life cycle of significant human pathogens like C.neoformans.