Estimating postmortem interval based on oral microbial community succession in rat cadavers

Area of Science:

• Forensic Science
• Microbiology
• Molecular Biology

Background:

• Accurate postmortem interval (PMI) estimation is critical in forensic investigations.
• Cadaver decay is influenced by microbial communities, with oral microbiota playing a significant role.
• High-throughput sequencing has advanced forensic microbiology, offering new PMI estimation methods.

Purpose of the Study:

• To investigate the relationship between oral microbial community succession and PMI in a simulated outdoor environment.
• To identify specific oral microorganisms as potential biomarkers for PMI estimation.

Main Methods:

• Collected outdoor soil to simulate a realistic death environment.
• Focused on analyzing oral microbial community changes over time in rat cadavers.
• Employed linear regression and random forest regression models to correlate microbial abundance with PMI.

Main Results:

• Established a link between oral microbial community dynamics and PMI.
• Identified several bacterial genera, including Ignatzschineria, Morganella, Proteus, and Pseudomonas, as potential indicators for PMI estimation.
• Developed predictive models for PMI based on oral microbial profiles.

Conclusions:

• Oral microbial community succession is a viable indicator for estimating PMI.
• Specific oral bacteria can serve as reliable biomarkers for forensic investigations.
• This research provides a novel approach to enhance the accuracy of postmortem interval determination.