Identification of fungi found on desiccated human remains in an arid outdoor environment

Three fungi not previously reported on desiccated human remains were identified on cadavers at the Forensic Investigation Research Station (FIRS) in Whitewater, Colorado. The location of the FIRS provides the unique opportunity to observe the stages of decomposition in a high desert environment. The two cadavers used in the study were in the late stages of decomposition (PMI of approximately 1520 and 1820 days) to the point of desiccation and had developed an extensive black crust on the skin that remained. Skin samples of the two cadavers were taken and plated onto potato dextrose agar to determine whether fungi were present on the desiccated tissues. Three different fungi consistently dominated cultures grown from numerous samples taken from each cadaver. Based on morphological observations, nuclear rDNA sequence data, and phylogenetic analyses, two fungi were identified to species (Aureobasidium melanogenum and Didymella glomerata) and one fungus was identified to the genus level (Alternaria). These results will contribute to the understanding of the role that fungi might play in late-stage decomposition and the extended postmortem period.