Thanatomicrombiome dynamics: bacterial community succession in the human mouth throughout decomposition

WCU Author/Contributor (non-WCU co-authors, if there are any, appear on document)
Emily Cathan Ashe (Creator)
Institution
Western Carolina University (WCU )
Web Site: http://library.wcu.edu/
Advisor
Seán O'Connell

Abstract: Research on the post-mortem human microbiome, or thanatomicrobiome, is a rapidly developing topic in the field of forensic science. To date, the study of the thanatomicrobiome has primarily been centered on utilizing the shifting bacterial communities associated with human decomposition to more effectively establish an accurate time of death. Often, this is done by sequencing the 16S rDNA of the entire community to observe the fluctuations in the composition of the community throughout decomposition, then using those community profiles to produce predictive models to determine the post-mortem interval. Given that few studies have attempted to incorporate the functional changes within these communities, the purpose of this experiment was to shed some light on the potential functions of these post-mortem microbial communities by examining not only the 16S rDNA of the community, but the entire metagenome and metatranscriptome of the community as well. As the substrate decomposes and nutrient sources are altered, it is reasonable to expect that the changing bacterial community will be accompanied by changes in the community’s metabolic capabilities. This experiment also included the identification and functional characterization of 47 unique cultured isolates some of whose identities were able to be tied back to their corresponding 16S rDNA communities and whose metabolic activities may be tied back to metatranscriptome of those communities. From this study it was likely that the thanatomicrobiome of the oral cavity was influenced by the environment (e.g., temperature, precipitation) and there were no clear patterns between the 16S rDNA community profiles and the post-mortem interval. These results suggest that the thanatomicrobiome of the mouth may not be as suitable as internal organ systems are for determining time since death. However, functional gene expression may yet reveal more useful patterns and work is ongoing in this endeavor.

Additional Information

Publication
Thesis
Language: English
Date: 2019
Keywords
16S, community, decomposition, post-mortem, succession, thanatomicrobiome

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