Correlating the Postmortem Interval to the Human Necromicrobiome in a Semi-Arid Desert Environment
Presentation Type
Poster Presentation
Category
Social Sciences/Humanities
Abstract/Artist Statement
Accurate estimation of the postmortem interval (PMI) is a central goal in forensic investigations. However, traditional methods based on observable physiological changes are highly variable and influenced by environmental and regional factors. This study investigates the human necromicrobiome, specifically skin-associated microbial communities, as a more reliable and standardized approach for PMI estimation in semi-arid environments. Necromicrobiome research supports the development of forensic taphonomic tools that enhance the accuracy and efficiency of human identification and expand access to justice, particularly in dry, arid regions.
Research was conducted at the Forensic Investigation Research Station (FIRS) in western Colorado, the westernmost and second-highest elevation human decomposition facility in the United States, located at 4,646 feet above sea level. This environment is underrepresented in existing PMI models, emphasizing the need for region-specific forensic tools. Taxonomic identification was performed through amplification of the bacterial 16S rRNA gene, and accumulated degree days (ADD) were used to establish PMI timelines.
Previous work by Burcham et al. (2024) demonstrated that skin-associated microbial communities provide more reliable PMI estimates than soil-based communities and participate in a consistent decomposition network across environments. Their results identified Helcococcus seattlensis as a strong predictor of PMI, with consistent presence across multiple climates, suggesting potential as a universal decomposer indicator. In contrast, taxa common in temperate environments, such as O. alkaliphila, Savagea sp., Peptoniphilus stercorisius, Ignatzschineria sp., and Acinetobacter sp., were less prevalent in arid conditions.
Similar microbial succession patterns are expected at FIRS, which would validate prior findings and provide a regional reference for forensic practitioners. Overall, this study contributes to the understanding of skin microbiome succession in semi-arid, high-elevation environments and supports the development of non-invasive, scientifically validated PMI estimation models.
Mentor Name
Meradeth Snow
Correlating the Postmortem Interval to the Human Necromicrobiome in a Semi-Arid Desert Environment
UC North Ballroom
Accurate estimation of the postmortem interval (PMI) is a central goal in forensic investigations. However, traditional methods based on observable physiological changes are highly variable and influenced by environmental and regional factors. This study investigates the human necromicrobiome, specifically skin-associated microbial communities, as a more reliable and standardized approach for PMI estimation in semi-arid environments. Necromicrobiome research supports the development of forensic taphonomic tools that enhance the accuracy and efficiency of human identification and expand access to justice, particularly in dry, arid regions.
Research was conducted at the Forensic Investigation Research Station (FIRS) in western Colorado, the westernmost and second-highest elevation human decomposition facility in the United States, located at 4,646 feet above sea level. This environment is underrepresented in existing PMI models, emphasizing the need for region-specific forensic tools. Taxonomic identification was performed through amplification of the bacterial 16S rRNA gene, and accumulated degree days (ADD) were used to establish PMI timelines.
Previous work by Burcham et al. (2024) demonstrated that skin-associated microbial communities provide more reliable PMI estimates than soil-based communities and participate in a consistent decomposition network across environments. Their results identified Helcococcus seattlensis as a strong predictor of PMI, with consistent presence across multiple climates, suggesting potential as a universal decomposer indicator. In contrast, taxa common in temperate environments, such as O. alkaliphila, Savagea sp., Peptoniphilus stercorisius, Ignatzschineria sp., and Acinetobacter sp., were less prevalent in arid conditions.
Similar microbial succession patterns are expected at FIRS, which would validate prior findings and provide a regional reference for forensic practitioners. Overall, this study contributes to the understanding of skin microbiome succession in semi-arid, high-elevation environments and supports the development of non-invasive, scientifically validated PMI estimation models.