Abstract
A fundamental question in the field of medical mycology is the origin of virulence in those fungal pathogens acquired directly from the environment. In recent years, it was proposed that the virulence of certain environmental animal-pathogenic microbes, such as Cryptococcus neoformans, originated from selection pressures caused by species-specific predation. In this study, we analyzed the interaction of C. neoformans with three Paramecium spp., all of which are ciliated mobile protists. In contrast to the interaction with amoebae, some Paramecium spp. rapidly ingested C. neoformans and killed the fungus. This study establishes yet another type of protist-fungal interaction supporting the notion that animal-pathogenic fungi in the environment are under constant selection by predation.
Acknowledgements
We thank Andre Nicola for helping with the fluorescent microscopy work and for providing Uvitex 2B. We also thank Susana Frases-Carvajal and Nareen Abboud for their insight and advice regarding each of the experimental procedures.
This work was supported by National Institutes of Health grants AI33774, AI33142, and HL59842-01 to A.C. CJC was supported by Training Program in Cellular and Molecular Biology and Genetics, T32 GM007491. SZF is supported by the Dr Marshall Horwitz Fellowship of Yeshiva University.
Declaration of interest: None.
This paper was first published online on Early Online on 15 March 2010.