Necrobiome Species Investigation on a Decomposing Sus scrofa Domesticus

This project identifies microbe species present within the necrobiome of a swine, Sus scrofa domesticus, decomposing in the microclimate of McMinnville, Oregon. Current forensic science research reports on the usefulness of monitoring microbiome taxa during the course of decomposition, finding that changes in the taxa follow a steady progression that can be used to determine postmortem interval (PMI), the amount of time it takes an animal to completely decompose. Forensic microbiome research uses statistical modeling based upon the known procreation rate for specific bacterial decomposer species to determine how long an individual has been decaying and has found moderate success as a forensic tool. Other methods of identifying PMI are notoriously unreliable primarily due to changes in individual ecosystems that are difficult to replicate elsewhere. We collected samples of biofilm growth over the decomposing swine and sequenced them, then compared the results to existing data. Acinetobacter and Carnobacterium were present, consistent with data from other studies. In conjunction with existing forensic taphonomy research, the results from this microbiological data can help establish a method for predicting the PMI in the Pacific NW. Future studies will collect data throughout the stages of decomposition to determine when species changes occur.