Discipline: Biological Sciences
Subcategory: Microbiology/Immunology/Virology
Shannon Pittman - Alabama State University
Co-Author(s): Gulnaz Javan, Alabama State University, Montgomery, AL
Studies of the human thanatomicrobiome (thanatos-, Greek for death) have demonstrated that microorganisms are the primary mediators of putrefaction after death. However, there are knowledge gaps concerning the source, diversity, and trajectory of microbes in regards to geographical factors related to cadavers. The current thanatomicrobiome study focuses on the consequences of host death on microbial signatures between corpses discovered in the United States and Finland. This study is the first of its kind to use next-generation sequencing and bioinformatics techniques to compare postmortem microbial diversity of corpses from two different geographical locations. We hypothesized that as a body decays, time-dependent succession of microbial signatures within the liver will establish dissimilar phylogenic profiles of bacterial taxa. We investigated the microorganisms obtained from the livers of corpses from 65 human remains from the two countries (n=130) with postmortem intervals ranging from 3-264 hours. To distinguish the composition and diversity of thanatomicrobiomic signatures, we performed DNA extraction, PCR, and high-throughput sequencing targeting the V4 region of the 16S rRNA gene using bacterial primers 515F-806R. As a positive control, microbial assessments of buccal cavity swabs were also analyzed. Our results revealed that there were significant differences (p <0.001) among locations and postmortem intervals in unweighted and weighted Unifrac ADONIS tests. Recent findings in our initial thanatomicrobiome studies of American corpses discovered that a majority of microorganisms in the human body after death are the obligate anaerobes, Clostridia. Surprisingly, in the current study, there was a paucity of Clostridia in the Finland corpses. A future research question would be, 'What is the influence of the Postmortem Clostridium Effect on microbial communities in human cadavers from distinct ecological niches'? Here, this study encompasses the largest cohort of cadavers to date and substantiates the Human Postmortem Microbiome Project.
Not SubmittedFunder Acknowledgement(s): National Science Foundation HRD 1401075
Faculty Advisor: Dr. Gulnaz Javan, gjavan@alasu.edu
Role: In conducting this research I performed i) DNA extraction, ii) Polymerase Chain Reaction, iii)Gel Electrophoresis