Meeting Abstract
In the context of wildlife forensics, knowing the time interval from the moment of death to discovery or the postmortem interval (PMI) range can reduce the number of potential suspects to those without a viable alibi for the time of the crime. A PMI range can be determined by tracking the temporal succession of the microbial communities associated with a decomposing body. We characterized temporal shifts in the taxonomic and in silico predicted functional composition of the postmortem microbiome associated with the gut tracts of European Starling (Sturnus vulgaris) carcasses over three days. The objectives for this study were to: 1) characterize the gut microbiomes of starlings antemortem and postmortem; 2) compare microbial taxonomic and functional composition among different gut tract regions including the small and large intestines, ceca, and cloaca; and 3) determine if and how avian gut microbial taxonomic and functional composition changed in a repeatable and predictive pattern during decomposition. We detected significant differences between antemortem and postmortem samples in both taxonomic and functional composition after 24 hours, but the microbiome remained stable between 24 and 72 hours postmortem. There were significant differences between gut tract regions in both taxonomic and in silico predicted functional composition antemortem, but sample location microbiomes converged after death. Our findings are the first to describe the postmortem microbiome in an avian model, and provide preliminary data for the potential forensic utility of the avian gut postmortem microbiome in estimating time of death.
