Identification of Antemortem and Postmortem Injuries in Nude Mice Based on Microbial Communities

Area of Science:

• Forensic Science
• Microbiology
• Pathology

Background:

• Differentiating antemortem (before death) from postmortem (after death) injuries is crucial in forensic investigations.
• Morphological examination alone can be insufficient for accurate injury timing.

Purpose of the Study:

• To establish antemortem and postmortem abdominal injury models in nude mice.
• To analyze morphological and microbial changes in wounds over time.
• To assess the utility of microbial community analysis in distinguishing antemortem from postmortem injuries.

Main Methods:

• Abdominal injury models were created in BALB/c nude mice, divided into antemortem and postmortem (4h, 72h) groups.
• Wound morphology and histopathology were assessed on days 1-15 post-injury.
• Microbial communities were analyzed using 16S rRNA sequencing, with diversity indices (Shannon, Observed species) and community composition (Jaccard similarity, PERMANOVA) evaluated.

Main Results:

• Morphological examination could not differentiate injury types by day 8.
• Significant differences in microbial diversity (Shannon, Observed species) and composition (Jaccard, PERMANOVA) were observed between antemortem and 72h postmortem groups.
• PERMANOVA R-squared values increased with time, indicating distinct microbial community shifts.

Conclusions:

• Wound microbial community analysis provides a novel method for differentiating antemortem from postmortem injuries.
• Microbial profiling offers valuable insights into injury timing, complementing traditional forensic methods.
• This approach shows promise for forensic applications in injury assessment.