Defense Date

2020

Document Type

Thesis

Degree Name

Master of Science

Department

Forensic Science

First Advisor

Dr. Baneshwar Singh

Second Advisor

Dr. Sarah Seashols-Wiliams

Third Advisor

Dr. Paul Brooks

Abstract

The conception of the Human Microbiome Project advanced the understanding of microbial communities in the human body and previous research has established that unique microbial signatures can help distinguish each body fluid. While these signatures have been developed for the prokaryotic microbiome, the next step is the examination of the eukaryotic microbiome. Eukaryotic signatures could provide a greater specificity and statistical weight when discerning between body fluids. These microbial markers can be implemented to develop a confirmatory assay for body fluid identification that works in tandem with other DNA based methods in the forensic workflow. Using a VCU approved IRB protocol, samples of urine (n=100), feces (n=72), and saliva (n=77) were collected. DNA was isolated and quantified using Qiagen’s QIAamp DNA Investigator and DNA Micro kits. The V9 region of the 18S rDNA was amplified using dual-index strategy and samples were sequenced on the Illumina MiSeq FGx. The sequences were analysed using Mothur (v 1.39.5) and RStudio (v 3.6.3). The relative abundance of eukaryote taxa and an Analysis of Molecular Variance (AMOVA) indicated significant differences in the eukaryotic community structure between all body fluids, except male and female urine. At the family level, feces was characterized by the combined presence of Saccharomycetaceae (80.1%). Malasseziaceae (37.4% male, 36.6% female) and Diptera (22.6% male, 19.4% female) were indicators for urine, while Poales (43.3%) and Asparagales (10.3%) indicated saliva. The species richness was greater in urine but less in feces and saliva when compared to the species richness of the prokaryotic microbiome. Overall, these results indicate that each body fluid has a unique eukaryotic community and potential for use in body fluid identification, especially as a compliment to the bacterial signatures that have already been developed. The results of this study are a novel addition to previous work, and advance the use of microbial forensics as an alternative method in forensic serology.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

5-5-2020

Available for download on Wednesday, May 05, 2021

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