The microbiology, pH, and oxidation reduction potential of larval masses in decomposing carcasses on Oahu, Hawaii

Publication date: Available online 9 August 2019Source: Journal of Forensic and Legal MedicineAuthor(s): Emily N. Junkins, Mark Speck, David O. CarterAbstractPrevious studies have begun to characterize the microbial community dynamics of the skin, soil, gut, and oral cavities of decomposing remains. One area that has yet to be explored in great detail is the microbiome of the fly larval mass, the community of immature flies that plays a significant role in decomposition. The current study aimed to characterize the microbiology and chemistry of larval masses established on pig (Sus scrofa domesticus) carcasses and to determine if these characteristics have potential as temporal evidence. Carcasses (n = 3) were decomposed on the soil surface of a tropical habitat on Oahu, Hawaii, USA and sampled over three days at 74 h, 80 h, 98 h, 104 h, 122 h, and 128 h (∼85–142 Accumulated Degree Days) postmortem. Larval masses were analyzed via high-throughput 16S rRNA sequencing and in situ chemical measurements (pH, temperature, oxidation-reduction potential). A trend was observed that resulted in three distinct microbial communities (pre-98 h, 98 h, and post-98 h). The oxidation-reduction potential (Eh) of larval masses apparently regulated microbial community structure with the most negative Eh being associated with the least rich and diverse microbial communities. Overall, a significant interaction between time and taxa was observed, particularly with bacteria...
Source: Journal of Forensic and Legal Medicine - Category: Forensic Medicine Source Type: research