1
|
Dawson BM, Ueland M, Carter DO, Mclntyre D, Barton PS. Bridging the gap between decomposition theory and forensic research on postmortem interval. Int J Legal Med 2024; 138:509-518. [PMID: 37491634 PMCID: PMC10861637 DOI: 10.1007/s00414-023-03060-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 07/05/2023] [Indexed: 07/27/2023]
Abstract
Knowledge of the decomposition of vertebrate animals has advanced considerably in recent years and revealed complex interactions among biological and environmental factors that affect rates of decay. Yet this complexity remains to be fully incorporated into research or models of the postmortem interval (PMI). We suggest there is both opportunity and a need to use recent advances in decomposition theory to guide forensic research and its applications to understanding the PMI. Here we synthesise knowledge of the biological and environmental factors driving variation in decomposition and the acknowledged limitations among current models of the PMI. To guide improvement in this area, we introduce a conceptual framework that highlights the multiple interdependencies affecting decay rates throughout the decomposition process. Our framework reinforces the need for a multidisciplinary approach to PMI research, and calls for an adaptive research cycle that aims to reduce uncertainty in PMI estimates via experimentation, modelling, and validation.
Collapse
Affiliation(s)
- Blake M Dawson
- School of Environmental and Rural Science, University of New England, Armidale, NSW, 2350, Australia.
| | - Maiken Ueland
- Centre for Forensic Science, School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - David O Carter
- Forensic Sciences Unit, School of Natural Sciences & Mathematics, Chaminade University of Honolulu, Honolulu, HI, 96822, USA
| | - Donna Mclntyre
- Graduate Research School, Federation University, Mount Helen, Ballarat, VIC, 3350, Australia
- Future Regions Research Centre, Federation University, Mount Helen, Ballarat, VIC, 3350, Australia
| | - Philip S Barton
- Future Regions Research Centre, Federation University, Mount Helen, Ballarat, VIC, 3350, Australia
- School of Life and Environmental Sciences, Deakin University, Geelong, VIC, 3216, Australia
| |
Collapse
|
2
|
Burcham ZM, Belk AD, McGivern BB, Bouslimani A, Ghadermazi P, Martino C, Shenhav L, Zhang AR, Shi P, Emmons A, Deel HL, Xu ZZ, Nieciecki V, Zhu Q, Shaffer M, Panitchpakdi M, Weldon KC, Cantrell K, Ben-Hur A, Reed SC, Humphry GC, Ackermann G, McDonald D, Chan SHJ, Connor M, Boyd D, Smith J, Watson JMS, Vidoli G, Steadman D, Lynne AM, Bucheli S, Dorrestein PC, Wrighton KC, Carter DO, Knight R, Metcalf JL. A conserved interdomain microbial network underpins cadaver decomposition despite environmental variables. Nat Microbiol 2024; 9:595-613. [PMID: 38347104 PMCID: PMC10914610 DOI: 10.1038/s41564-023-01580-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 12/08/2023] [Indexed: 03/07/2024]
Abstract
Microbial breakdown of organic matter is one of the most important processes on Earth, yet the controls of decomposition are poorly understood. Here we track 36 terrestrial human cadavers in three locations and show that a phylogenetically distinct, interdomain microbial network assembles during decomposition despite selection effects of location, climate and season. We generated a metagenome-assembled genome library from cadaver-associated soils and integrated it with metabolomics data to identify links between taxonomy and function. This universal network of microbial decomposers is characterized by cross-feeding to metabolize labile decomposition products. The key bacterial and fungal decomposers are rare across non-decomposition environments and appear unique to the breakdown of terrestrial decaying flesh, including humans, swine, mice and cattle, with insects as likely important vectors for dispersal. The observed lockstep of microbial interactions further underlies a robust microbial forensic tool with the potential to aid predictions of the time since death.
Collapse
Affiliation(s)
- Zachary M Burcham
- Department of Animal Sciences, Colorado State University, Fort Collins, CO, USA
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - Aeriel D Belk
- Department of Animal Sciences, Colorado State University, Fort Collins, CO, USA
- Department of Animal Sciences, Auburn University, Auburn, AL, USA
| | - Bridget B McGivern
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA
| | - Amina Bouslimani
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, San Diego, CA, USA
| | - Parsa Ghadermazi
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO, USA
| | - Cameron Martino
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA
| | - Liat Shenhav
- Center for Studies in Physics and Biology, Rockefeller University, New York, NY, USA
- Institute for Systems Genetics, New York Grossman School of Medicine, New York University, New York, NY, USA
- Department of Computer Science, New York University, New York, NY, USA
| | - Anru R Zhang
- Department of Biostatistics and Bioinformatics, Duke University, Durham, NC, USA
- Department of Computer Science, Duke University, Durham, NC, USA
| | - Pixu Shi
- Department of Biostatistics and Bioinformatics, Duke University, Durham, NC, USA
| | - Alexandra Emmons
- Department of Animal Sciences, Colorado State University, Fort Collins, CO, USA
| | - Heather L Deel
- Graduate Program in Cell and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Zhenjiang Zech Xu
- School of Food Science and Technology, Nanchang University, Nanchang, Jiangxi, China
| | - Victoria Nieciecki
- Department of Animal Sciences, Colorado State University, Fort Collins, CO, USA
- Graduate Program in Cell and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Qiyun Zhu
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
- Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ, USA
| | - Michael Shaffer
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA
| | - Morgan Panitchpakdi
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, San Diego, CA, USA
| | - Kelly C Weldon
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, San Diego, CA, USA
| | - Kalen Cantrell
- Department of Computer Science and Engineering, University of California San Diego, La Jolla, CA, USA
| | - Asa Ben-Hur
- Department of Computer Science, Colorado State University, Fort Collins, CO, USA
| | - Sasha C Reed
- U.S. Geological Survey, Southwest Biological Science Center, Moab, UT, USA
| | - Greg C Humphry
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA
| | - Gail Ackermann
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA
| | - Daniel McDonald
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA
| | - Siu Hung Joshua Chan
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO, USA
| | - Melissa Connor
- Forensic Investigation Research Station, Colorado Mesa University, Grand Junction, CO, USA
| | - Derek Boyd
- Forensic Anthropology Center, Department of Anthropology, University of Tennessee, Knoxville, TN, USA
- Department of Social, Cultural, and Justice Studies, University of Tennessee at Chattanooga, Chattanooga, TN, USA
| | - Jake Smith
- Forensic Anthropology Center, Department of Anthropology, University of Tennessee, Knoxville, TN, USA
- Mid-America College of Funeral Service, Jeffersonville, IN, USA
| | - Jenna M S Watson
- Forensic Anthropology Center, Department of Anthropology, University of Tennessee, Knoxville, TN, USA
| | - Giovanna Vidoli
- Forensic Anthropology Center, Department of Anthropology, University of Tennessee, Knoxville, TN, USA
| | - Dawnie Steadman
- Forensic Anthropology Center, Department of Anthropology, University of Tennessee, Knoxville, TN, USA
| | - Aaron M Lynne
- Department of Biological Sciences, Sam Houston State University, Huntsville, TX, USA
| | - Sibyl Bucheli
- Department of Biological Sciences, Sam Houston State University, Huntsville, TX, USA
| | - Pieter C Dorrestein
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, San Diego, CA, USA
| | - Kelly C Wrighton
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA
| | - David O Carter
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, School of Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, HI, USA
| | - Rob Knight
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA
- Department of Computer Science and Engineering, University of California San Diego, La Jolla, CA, USA
- Center for Microbiome Innovation, University of California San Diego, La Jolla, CA, USA
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Jessica L Metcalf
- Department of Animal Sciences, Colorado State University, Fort Collins, CO, USA.
- Graduate Program in Cell and Molecular Biology, Colorado State University, Fort Collins, CO, USA.
- Humans and the Microbiome Program, Canadian Institute for Advanced Research, Toronto, Ontario, Canada.
| |
Collapse
|
3
|
Carter DO, Orimoto A, Gutierrez CA, Ribéreau-Gayon A, Pecsi EL, Perrault KA, Peterson AJ. A synthesis of carcass decomposition studies conducted at a tropical (Aw) taphonomy facility: 2013-2022. Forensic Sci Int Synerg 2023; 7:100345. [PMID: 37609572 PMCID: PMC10440585 DOI: 10.1016/j.fsisyn.2023.100345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/24/2023]
Abstract
Decomposition studies have been conducted in several regions of the world, but relatively few have investigated taphonomy in tropical environments. Even fewer have explored carcass decomposition during multiple tropical seasons, leaving the relationships between season and decomposition in tropical environments poorly understood. Ten decomposition studies using 30 carcasses were conducted in Honolulu, Hawaii, USA to start addressing this knowledge gap. These studies show that some postmortem processes were observed regardless of season. Carcass temperature and chemistry were spatiotemporally variable. Fly larval masses were consistently observed within 3 days (∼75 ADD) postmortem and carcasses lost 60%-90% of mass by 10 days (∼250 ADD) postmortem (Total Body Score ∼26). Season had a significant effect on decomposition, yet the warmest and most humid seasons did not always result in the most rapid and extensive decomposition. Seasonal variation appears to be less pronounced than at other tropical decomposition sites.
Collapse
Affiliation(s)
- David O. Carter
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, School of Natural Sciences & Mathematics, Chaminade University of Honolulu, Hawaii, USA
| | - Adam Orimoto
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, School of Natural Sciences & Mathematics, Chaminade University of Honolulu, Hawaii, USA
- Scientific Investigation Section, Honolulu Police Department, Honolulu, HI, USA
| | - Carlos A. Gutierrez
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, School of Natural Sciences & Mathematics, Chaminade University of Honolulu, Hawaii, USA
- True Forensic Science, Santiago, Chile
| | - Agathe Ribéreau-Gayon
- Department of Chemistry, Biochemistry, and Physics, Université du Québec à Trois-Rivières, Québec, Canada
- Research Group in Forensic Science, Université du Québec à Trois-Rivières, Québec, Canada
| | - Emily L. Pecsi
- Department of Anatomy, Université du Québec à Trois-Rivières, Québec, Canada
- Department of Environmental Sciences, Université du Québec à Trois-Rivières, Québec, Canada
| | - Katelynn A. Perrault
- Laboratory of Forensic and Bioanalytical Chemistry, Forensic Sciences Unit, School of Natural Sciences & Mathematics, Chaminade University of Honolulu, Hawaii, USA
| | - Alexis J.L. Peterson
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, School of Natural Sciences & Mathematics, Chaminade University of Honolulu, Hawaii, USA
- Department of the Medical Examiner, City and County of Honolulu, Honolulu, HI, USA
| |
Collapse
|
4
|
Ribéreau-Gayon A, Carter DO, Forbes S. Developing a new scoring method to evaluate human decomposition in a humid, continental (Dfb) climate in Quebec. J Forensic Sci 2023; 68:536-548. [PMID: 36645695 DOI: 10.1111/1556-4029.15201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/28/2022] [Accepted: 01/04/2023] [Indexed: 01/17/2023]
Abstract
The published literature shows a lack of methods to evaluate the patterns and extent of decomposition of human remains and to estimate the post-mortem interval (PMI) in humid, continental (Dfb) climates such as Quebec. The aim of this study was to address this gap in the current knowledge base by providing the first observations from human corpses studied under controlled conditions in Quebec. A 12-month study was conducted at the site for Research in Experimental and Social Thanatology; the first human taphonomy facility in Canada. Six human donors with known time of death were deposited across spring (n = 1), summer (n = 3), and autumn (n = 2) 2021. The lack of suitability of the total body score method to evaluate the extent of decomposition at the facility prompted the development of a new scoring system based on the macromorphoscopic changes observed. The scoring system was applied to the donors to evaluate decomposition throughout seasons. All donors followed comparable decomposition trajectories, regardless of the season of deposition. Eighty-five percent of taphonomic patterns appeared in the first 25 experimental days or 5000 Kelvin accumulated degree days (350 ADD). Extensive desiccation of tissues was observed at a median of 21 experimental days across donors, resulting in a plateau within decomposition with no extensive skeletonization. To the authors' knowledge, this is the first published report of experimentally observed desiccation in such a form in a Dfb climate. This study provides new data on the types of decomposition patterns to expect in forensic investigations in southern Quebec and comparable climates.
Collapse
Affiliation(s)
- Agathe Ribéreau-Gayon
- Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada.,Groupe de Recherche en Science Forensique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada.,Centre International de Criminologie Comparée, Université de Montréal, Montréal, Québec, Canada
| | - David O Carter
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, School of Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, Hawaii, USA
| | - Shari Forbes
- Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada.,Groupe de Recherche en Science Forensique, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada.,Centre International de Criminologie Comparée, Université de Montréal, Montréal, Québec, Canada
| |
Collapse
|
5
|
Deel H, Emmons AL, Kiely J, Damann FE, Carter DO, Lynne A, Knight R, Xu ZZ, Bucheli S, Metcalf JL. A Pilot Study of Microbial Succession in Human Rib Skeletal Remains during Terrestrial Decomposition. mSphere 2021; 6:e0045521. [PMID: 34259562 PMCID: PMC8386422 DOI: 10.1128/msphere.00455-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 06/21/2021] [Indexed: 11/20/2022] Open
Abstract
The bones of decomposing vertebrates are colonized by a succession of diverse microbial communities. If this succession is similar across individuals, microbes may provide clues about the postmortem interval (PMI) during forensic investigations in which human skeletal remains are discovered. Here, we characterize the human bone microbial decomposer community to determine whether microbial succession is a marker for PMI. Six human donor subjects were placed outdoors to decompose on the soil surface at the Southeast Texas Applied Forensic Science facility. To also assess the effect of seasons, three decedents were placed each in the spring and summer. Once ribs were exposed through natural decomposition, a rib was collected from each body for eight time points at 3 weeks apart. We discovered a core bone decomposer microbiome dominated by taxa in the phylum Proteobacteria and evidence that these bone-invading microbes are likely sourced from the surrounding decomposition environment, including skin of the cadaver and soils. Additionally, we found significant overall differences in bone microbial community composition between seasons. Finally, we used the microbial community data to develop random forest models that predict PMI with an accuracy of approximately ±34 days over a 1- to 9-month time frame of decomposition. Typically, anthropologists provide PMI estimates based on qualitative information, giving PMI errors ranging from several months to years. Previous work has focused on only the characterization of the bone microbiome decomposer community, and this is the first known data-driven, quantitative PMI estimate of terrestrially decomposed human skeletal remains using microbial abundance information. IMPORTANCE Microbes are known to facilitate vertebrate decomposition, and they can do so in a repeatable, predictable manner. The succession of microbes in the skin and associated soil can be used to predict time since death during the first few weeks of decomposition. However, when remains are discovered after months or years, often the only evidence are skeletal remains. To determine if microbial succession in bone would be useful for estimating time since death after several months, human subjects were placed to decompose in the spring and summer seasons. Ribs were collected after 1 to 9 months of decomposition, and the bone microbial communities were characterized. Analysis revealed a core bone decomposer microbial community with some differences in microbial assembly occurring between seasons. These data provided time since death estimates of approximately ±34 days over 9 months. This may provide forensic investigators with a tool for estimating time since death of skeletal remains, for which there are few current methods.
Collapse
Affiliation(s)
- Heather Deel
- Program in Cell & Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
- Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Alexandra L. Emmons
- Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Jennifer Kiely
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas, USA
| | | | - David O. Carter
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, Chaminade University of Honolulu, Honolulu, Hawaii, USA
- School of Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, Hawaii, USA
| | - Aaron Lynne
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas, USA
| | - Rob Knight
- Center for Microbiome Innovation, University of California San Diego, La Jolla, California, USA
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA
- Department of Computer Science and Engineering, University of California San Diego, La Jolla, California, USA
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
| | - Zhenjiang Zech Xu
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA
| | - Sibyl Bucheli
- Department of Biological Sciences, Sam Houston State University, Huntsville, Texas, USA
| | - Jessica L. Metcalf
- Program in Cell & Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
- Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, USA
| |
Collapse
|
6
|
Mickleburgh HL, Schwalbe EC, Bonicelli A, Mizukami H, Sellitto F, Starace S, Wescott DJ, Carter DO, Procopio N. Human Bone Proteomes before and after Decomposition: Investigating the Effects of Biological Variation and Taphonomic Alteration on Bone Protein Profiles and the Implications for Forensic Proteomics. J Proteome Res 2021; 20:2533-2546. [PMID: 33683123 PMCID: PMC8155572 DOI: 10.1021/acs.jproteome.0c00992] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
![]()
Bone proteomic studies
using animal proxies and skeletonized human
remains have delivered encouraging results in the search for potential
biomarkers for precise and accurate post-mortem interval (PMI) and
the age-at-death (AAD) estimation in medico-legal investigations.
The development of forensic proteomics for PMI and AAD estimation
is in critical need of research on human remains throughout decomposition,
as currently the effects of both inter-individual biological differences
and taphonomic alteration on the survival of human bone protein profiles
are unclear. This study investigated the human bone proteome in four
human body donors studied throughout decomposition outdoors. The effects
of ageing phenomena (in vivo and post-mortem) and
intrinsic and extrinsic variables on the variety and abundancy of
the bone proteome were assessed. Results indicate that taphonomic
and biological variables play a significant role in the survival of
proteins in bone. Our findings suggest that inter-individual and inter-skeletal
differences in bone mineral density (BMD) are important variables
affecting the survival of proteins. Specific proteins survive better
within the mineral matrix due to their mineral-binding properties.
The mineral matrix likely also protects these proteins by restricting
the movement of decomposer microbes. New potential biomarkers for
PMI estimation and AAD estimation were identified. Future development
of forensic bone proteomics should include standard measurement of
BMD and target a combination of different biomarkers.
Collapse
Affiliation(s)
- Hayley L Mickleburgh
- Department of Cultural Sciences, Linnaeus University, Kalmar 352 52, Sweden.,Forensic Anthropology Center, Texas State University, San Marcos 78666, Texas, United States
| | - Edward C Schwalbe
- Forensic Science Research Group, Faculty of Health and Life Sciences, Northumbria University, Ellison Building, Northumbria University Newcastle, Newcastle Upon Tyne NE1 8ST, U. K
| | - Andrea Bonicelli
- Forensic Science Research Group, Faculty of Health and Life Sciences, Northumbria University, Ellison Building, Northumbria University Newcastle, Newcastle Upon Tyne NE1 8ST, U. K
| | - Haruka Mizukami
- Forensic Science Research Group, Faculty of Health and Life Sciences, Northumbria University, Ellison Building, Northumbria University Newcastle, Newcastle Upon Tyne NE1 8ST, U. K
| | - Federica Sellitto
- Forensic Science Research Group, Faculty of Health and Life Sciences, Northumbria University, Ellison Building, Northumbria University Newcastle, Newcastle Upon Tyne NE1 8ST, U. K
| | - Sefora Starace
- Dipartimento di Chimica, University of Turin, Via P. Giuria 7, 10125 Turin, Italy
| | - Daniel J Wescott
- Forensic Anthropology Center, Texas State University, San Marcos 78666, Texas, United States
| | - David O Carter
- Forensic Sciences Unit, School of Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu 96816, Hawaii, United States
| | - Noemi Procopio
- Forensic Science Research Group, Faculty of Health and Life Sciences, Northumbria University, Ellison Building, Northumbria University Newcastle, Newcastle Upon Tyne NE1 8ST, U. K
| |
Collapse
|
7
|
Emmons AL, Mundorff AZ, Keenan SW, Davoren J, Andronowski J, Carter DO, DeBruyn JM. Characterizing the postmortem human bone microbiome from surface-decomposed remains. PLoS One 2020; 15:e0218636. [PMID: 32639969 PMCID: PMC7343130 DOI: 10.1371/journal.pone.0218636] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 05/19/2020] [Indexed: 01/19/2023] Open
Abstract
Microbial colonization of bone is an important mechanism of postmortem skeletal degradation. However, the types and distributions of bone and tooth colonizing microbes are not well characterized. It is unknown if microbial communities vary in abundance or composition between bone element types, which could help explain differences in human DNA preservation. The goals of the present study were to (1) identify the types of microbes capable of colonizing different human bone types and (2) relate microbial abundances, diversity, and community composition to bone type and human DNA preservation. DNA extracts from 165 bone and tooth samples from three skeletonized individuals were assessed for bacterial loading and microbial community composition and structure. Random forest models were applied to predict operational taxonomic units (OTUs) associated with human DNA concentration. Dominant bacterial bone colonizers were from the phyla Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes, and Planctomycetes. Eukaryotic bone colonizers were from Ascomycota, Apicomplexa, Annelida, Basidiomycota, and Ciliophora. Bacterial loading was not a significant predictor of human DNA concentration in two out of three individuals. Random forest models were minimally successful in identifying microbes related to human DNA concentration, which were complicated by high variability in community structure between individuals and body regions. This work expands on our understanding of the types of microbes capable of colonizing the postmortem human skeleton and potentially contributing to human skeletal DNA degradation.
Collapse
Affiliation(s)
- Alexandra L. Emmons
- Department of Anthropology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Amy Z. Mundorff
- Department of Anthropology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Sarah W. Keenan
- Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, Rapid City, South Dakota, United States of America
| | - Jonathan Davoren
- Bode Cellmark Forensics, Lorton, Virginia, United States of America
| | - Janna Andronowski
- Department of Anthropology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - David O. Carter
- Division of Natural Sciences and Mathematics, Laboratory of Forensic Taphonomy, Forensic Sciences Unit, Chaminade University of Honolulu, Honolulu, Hawaii, United States of America
| | - Jennifer M. DeBruyn
- Department of Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, Tennessee, United States of America
- * E-mail:
| |
Collapse
|
8
|
Junkins EN, Speck M, Carter DO. The microbiology, pH, and oxidation reduction potential of larval masses in decomposing carcasses on Oahu, Hawaii. J Forensic Leg Med 2019; 67:37-48. [DOI: 10.1016/j.jflm.2019.08.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 07/02/2019] [Accepted: 08/08/2019] [Indexed: 01/08/2023]
|
9
|
Cernosek T, Eckert KE, Carter DO, Perrault KA. Volatile Organic Compound Profiling from Postmortem Microbes using Gas Chromatography-Mass Spectrometry. J Forensic Sci 2019; 65:134-143. [PMID: 31479524 DOI: 10.1111/1556-4029.14173] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/02/2019] [Accepted: 08/05/2019] [Indexed: 11/29/2022]
Abstract
Volatile organic compounds (VOCs) are by-products of cadaveric decomposition and are responsible for the odor associated with decomposing remains. The direct link between VOC production and individual postmortem microbes has not been well characterized experimentally. The purpose of this study was to profile VOCs released from three postmortem bacterial isolates (Bacillus subtilis, Ignatzschineria indica, I. ureiclastica) using solid-phase microextraction arrow (SPME Arrow) and gas chromatography-mass spectrometry (GC-MS). Species were inoculated in headspace vials on Standard Nutrient Agar and monitored over 5 days at 24°C. Each species exhibited a different VOC profile that included common decomposition VOCs. VOCs exhibited upward or downward temporal trends over time. Ignatzschineria indica produced a large amount of dimethyldisulfide. Other compounds of interest included alcohols, aldehydes, aromatics, and ketones. This provides foundational data to link decomposition odor with specific postmortem microbes to improve understanding of underlying mechanisms for decomposition VOC production.
Collapse
Affiliation(s)
- Terezie Cernosek
- Laboratory of Forensic and Bioanalytical Chemistry, Forensic Sciences Unit, Division of Natural Sciences and Mathematics, Chaminade University of Honolulu, 3140 Waialae Avenue, Honolulu, HI
| | - Kevin E Eckert
- Laboratory of Forensic and Bioanalytical Chemistry, Forensic Sciences Unit, Division of Natural Sciences and Mathematics, Chaminade University of Honolulu, 3140 Waialae Avenue, Honolulu, HI
| | - David O Carter
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, Division of Natural Sciences and Mathematics, Chaminade University of Honolulu, 3140 Waialae Avenue, Honolulu, HI
| | - Katelynn A Perrault
- Laboratory of Forensic and Bioanalytical Chemistry, Forensic Sciences Unit, Division of Natural Sciences and Mathematics, Chaminade University of Honolulu, 3140 Waialae Avenue, Honolulu, HI
| |
Collapse
|
10
|
Dibner H, Mangca Valdez C, Carter DO. An Experiment to Characterize the Decomposer Community Associated with Carcasses (
Sus scrofa domesticus
) on Oahu, Hawaii. J Forensic Sci 2019; 64:1412-1420. [DOI: 10.1111/1556-4029.14009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 12/10/2018] [Accepted: 01/07/2019] [Indexed: 01/08/2023]
Affiliation(s)
- Hannah Dibner
- Laboratory of Forensic Taphonomy Forensic Sciences Unit Division of Natural Sciences and Mathematics Chaminade University of Honolulu Honolulu HI 96816
- SNA International, supporting Defense POW/MIA Accounting Agency Laboratory Joint Base Pearl Harbor‐Hickam Honolulu HI 96853
| | - Chelsie Mangca Valdez
- Laboratory of Forensic Taphonomy Forensic Sciences Unit Division of Natural Sciences and Mathematics Chaminade University of Honolulu Honolulu HI 96816
- Division of Social Sciences University of Hawaii – West Oahu Kapolei HI 96707
| | - David O. Carter
- Laboratory of Forensic Taphonomy Forensic Sciences Unit Division of Natural Sciences and Mathematics Chaminade University of Honolulu Honolulu HI 96816
| |
Collapse
|
11
|
Kodama WA, Xu Z, Metcalf JL, Song SJ, Harrison N, Knight R, Carter DO, Happy CB. Trace Evidence Potential in Postmortem Skin Microbiomes: From Death Scene to Morgue. J Forensic Sci 2018; 64:791-798. [PMID: 30408195 DOI: 10.1111/1556-4029.13949] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 10/11/2018] [Accepted: 10/12/2018] [Indexed: 11/29/2022]
Abstract
Microbes can be used effectively as trace evidence, at least in research settings. However, it is unknown whether skin microbiomes change prior to autopsy and, if so, whether these changes interfere with linking objects to decedents. The current study included microbiomes from 16 scenes of death in the City and County of Honolulu and tested whether objects at the scenes can be linked to individual decedents. Postmortem skin microbiomes were stable during repeated sampling up to 60 h postmortem and were similar to microbiomes of an antemortem population. Objects could be traced to decedents approximately 75% of the time, with smoking pipes and medical devices being especially accurate (100% match), house and car keys being poor (0%), and other objects like phones intermediate (~80%). These results show that microbes from objects at death scenes can be matched to individual decedents, opening up a new method of establishing associations and identifications.
Collapse
Affiliation(s)
- Whitney A Kodama
- City and County of Honolulu Department of the Medical Examiner, 835 Iwilei Street, Honolulu, 96817, HI.,Laboratory of Forensic Taphonomy, Forensic Sciences Unit, Division of Natural Sciences and Mathematics, Chaminade University of Honolulu, 3140 Waialae Avenue, Honolulu, 96816, HI
| | - Zhenjiang Xu
- School of Food Science and Technology, Nanchang University, 235 Nanjing East Road, Nanchang City, Jiangxi, Nanchang, China.,State Key Laboratory of Food Science and Technology, Nanchang University, 235 Nanjing East Road, Nanchang City, Jiangxi, Nanchang, China.,Department of Pediatrics, University of California, San Diego, 9500 Gilman Drive, La Jolla, 92093, CA
| | - Jessica L Metcalf
- Department of Animal Sciences, Colorado State University, 350 W. Pitkin Street, Ft. Collins, 80523-1171, CO
| | - Se Jin Song
- Department of Pediatrics, University of California, San Diego, 9500 Gilman Drive, La Jolla, 92093, CA
| | - Nicholas Harrison
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, Division of Natural Sciences and Mathematics, Chaminade University of Honolulu, 3140 Waialae Avenue, Honolulu, 96816, HI
| | - Rob Knight
- Department of Pediatrics, University of California, San Diego, 9500 Gilman Drive, La Jolla, 92093, CA.,Department of Computer Science and Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, 92093, CA.,Center for Microbiome Innovation, University of California, San Diego, 9500 Gilman Drive, La Jolla, 92093-0403, CA
| | - David O Carter
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, Division of Natural Sciences and Mathematics, Chaminade University of Honolulu, 3140 Waialae Avenue, Honolulu, 96816, HI
| | - Christopher B Happy
- City and County of Honolulu Department of the Medical Examiner, 835 Iwilei Street, Honolulu, 96817, HI
| |
Collapse
|
12
|
Ribéreau-Gayon A, Carter DO, Regan S. New evidence of predation on humans by cookiecutter sharks in Kauai, Hawaii. Int J Legal Med 2018; 132:1381-1387. [PMID: 29445874 PMCID: PMC6096562 DOI: 10.1007/s00414-018-1786-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 01/17/2018] [Indexed: 11/27/2022]
Abstract
The feeding patterns of species of large sharks on human corpses are well documented in the literature however, that of smaller sharks are less known. This may introduce uncertainty in the medicolegal conclusions. For that reason, accurate identification of patterns of shark predation is very relevant, specifically in areas bordered by the sea. In the case described here, an unidentified lesion was noted on the body of a victim of a scuba diving accident off the island of Kauai, in Hawaii. The aim of this study was to identify the origin of the lesion and investigate its potential to inform on the context of death and/or decomposition. The original outline of the lesion was digitally reconstructed to enable the collection of measurements which were compared with the literature and interpreted with an interdisciplinary approach. This approach permitted to determine that the macroscopic appearance and dimensions of the lesion (major axis = 3.53 cm) were consistent with a bitemark of a cookiecutter shark (Isistius brasiliensis). It was further determined that the bitemark was incomplete and that the specimen involved had a total length of about 24 cm and was likely to be a juvenile. This is the second report in the published literature of cookiecutter bitemarks on humans in the Hawaiian waters. This study brings new evidence-based insights into the interactions between cookiecutter sharks and human remains in marine environments and provides a valuable contribution to the knowledge base on the topic.
Collapse
Affiliation(s)
- Agathe Ribéreau-Gayon
- Institute of Archaeology, University College London, 31-34 Gordon Square, London, WC1H 0PY, UK. .,Department of Security and Crime Science-Centre for the Forensic Sciences, University College London, 35 Tavistock Square, London, WC1H 9EZ, UK. .,Centre for the Forensic Sciences, University College London, 35 Tavistock Square, London, WC1H 9EZ, UK.
| | - David O Carter
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, Division of Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, HI, USA
| | | |
Collapse
|
13
|
Belk AD, Deel HL, Burcham ZM, Knight R, Carter DO, Metcalf JL. Animal models for understanding microbial decomposition of human remains. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.ddmod.2019.08.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
14
|
Ribéreau-Gayon A, Rando C, Morgan RM, Carter DO. The suitability of visual taphonomic methods for digital photographs: An experimental approach with pig carcasses in a tropical climate. Sci Justice 2017; 58:167-176. [PMID: 29685298 DOI: 10.1016/j.scijus.2017.12.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 11/24/2017] [Accepted: 12/04/2017] [Indexed: 10/18/2022]
Abstract
In the context of increased scrutiny of the methods in forensic sciences, it is essential to ensure that the approaches used in forensic taphonomy to measure decomposition and estimate the postmortem interval are underpinned by robust evidence-based data. Digital photographs are an important source of documentation in forensic taphonomic investigations but the suitability of the current approaches for photographs, rather than real-time remains, is poorly studied which can undermine accurate forensic conclusions. The present study aimed to investigate the suitability of 2D colour digital photographs for evaluating decomposition of exposed human analogues (Sus scrofa domesticus) in a tropical savanna environment (Hawaii), using two published scoring methods; Megyesi et al., 2005 and Keough et al., 2017. It was found that there were significant differences between the real-time and photograph decomposition scores when the Megyesi et al. method was used. However, the Keough et al. method applied to photographs reflected real-time decomposition more closely and thus appears more suitable to evaluate pig decomposition from 2D photographs. The findings indicate that the type of scoring method used has a significant impact on the ability to accurately evaluate the decomposition of exposed pig carcasses from photographs. It was further identified that photographic taphonomic analysis can reach high inter-observer reproducibility. These novel findings are of significant importance for the forensic sciences as they highlight the potential for high quality photograph coverage to provide useful complementary information for the forensic taphonomic investigation. New recommendations to develop robust transparent approaches adapted to photographs in forensic taphonomy are suggested based on these findings.
Collapse
Affiliation(s)
- Agathe Ribéreau-Gayon
- Department of Security and Crime Science, University College London, 35 Tavistock Square, London WC1H 9EZ, United Kingdom; Centre for the Forensic Sciences, University College London, 35 Tavistock Square, London WC1H 9EZ, United Kingdom; Institute of Archaeology, University College London, 31-34 Gordon Square, London WC1H 0PY, United Kingdom.
| | - Carolyn Rando
- Institute of Archaeology, University College London, 31-34 Gordon Square, London WC1H 0PY, United Kingdom.
| | - Ruth M Morgan
- Department of Security and Crime Science, University College London, 35 Tavistock Square, London WC1H 9EZ, United Kingdom; Centre for the Forensic Sciences, University College London, 35 Tavistock Square, London WC1H 9EZ, United Kingdom.
| | - David O Carter
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, Division of Natural Sciences and Mathematics, Chaminade University of Honolulu, HI, United States.
| |
Collapse
|
15
|
Metcalf JL, Xu ZZ, Bouslimani A, Dorrestein P, Carter DO, Knight R. Microbiome Tools for Forensic Science. Trends Biotechnol 2017; 35:814-823. [PMID: 28366290 DOI: 10.1016/j.tibtech.2017.03.006] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 01/28/2023]
Abstract
Microbes are present at every crime scene and have been used as physical evidence for over a century. Advances in DNA sequencing and computational approaches have led to recent breakthroughs in the use of microbiome approaches for forensic science, particularly in the areas of estimating postmortem intervals (PMIs), locating clandestine graves, and obtaining soil and skin trace evidence. Low-cost, high-throughput technologies allow us to accumulate molecular data quickly and to apply sophisticated machine-learning algorithms, building generalizable predictive models that will be useful in the criminal justice system. In particular, integrating microbiome and metabolomic data has excellent potential to advance microbial forensics.
Collapse
Affiliation(s)
- Jessica L Metcalf
- Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523, USA.
| | - Zhenjiang Z Xu
- Department of Pediatrics, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Amina Bouslimani
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Pieter Dorrestein
- Department of Pediatrics, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA; Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA; Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA; Center for Microbiome Innovation, Jacobs School of Engineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - David O Carter
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, Division of Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, HI 96816, USA
| | - Rob Knight
- Department of Pediatrics, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA; Center for Microbiome Innovation, Jacobs School of Engineering, University of California, San Diego, La Jolla, CA 92093, USA; Department of Computer Science and Engineering, Jacobs School of Engineering, University of California San Diego, La Jolla, CA 92093, USA
| |
Collapse
|
16
|
Maile AE, Inoue CG, Barksdale LE, Carter DO. Toward a universal equation to estimate postmortem interval. Forensic Sci Int 2017; 272:150-153. [DOI: 10.1016/j.forsciint.2017.01.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 01/09/2017] [Accepted: 01/10/2017] [Indexed: 10/20/2022]
|
17
|
Flores D, Miller AL, Showman A, Tobita C, Shimoda LMN, Sung C, Stokes AJ, Tomberlin JK, Carter DO, Turner H. Fluorescence Imaging of Posterior Spiracles from Second and Third Instars of Forensically Important Chrysomya rufifacies (Diptera: Calliphoridae) . J Forensic Sci 2016; 61:1578-1587. [PMID: 27706817 DOI: 10.1111/1556-4029.13189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 01/22/2016] [Accepted: 01/23/2016] [Indexed: 11/30/2022]
Abstract
Entomological protocols for aging blowfly (Diptera: Calliphoridae) larvae to estimate the time of colonization (TOC) are commonly used to assist in death investigations. While the methodologies for analyzing fly larvae differ, most rely on light microscopy, genetic analysis, or, more rarely, electron microscopy. This pilot study sought to improve resolution of larval stage in the forensically important blowfly Chrysomya rufifacies using high-content fluorescence microscopy and biochemical measures of developmental marker proteins. We established fixation and mounting protocols, defined a set of measurable morphometric criteria and captured developmental transitions of 2nd instar to 3rd instar using both fluorescence microscopy and anti-ecdysone receptor Western blot analysis. The data show that these instars can be distinguished on the basis of robust, nonbleaching, autofluorescence of larval posterior spiracles. High-content imaging techniques using confocal microscopy, combined with morphometric and biochemical techniques, may therefore aid forensic entomologists in estimating TOC.
Collapse
Affiliation(s)
- Danielle Flores
- Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816.,Graduate Program in Molecular Biosciences and Bioengineering, University of Hawaii at Mānoa, 1650 East-West Road, Honolulu, HI, 96816
| | - Amy L Miller
- Graduate Program in Molecular Biosciences and Bioengineering, University of Hawaii at Mānoa, 1650 East-West Road, Honolulu, HI, 96816
| | - Angelique Showman
- Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816.,Laboratory of Forensic Taphonomy, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816
| | - Caitlyn Tobita
- Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816
| | - Lori M N Shimoda
- Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816
| | - Carl Sung
- Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816
| | - Alexander J Stokes
- Laboratory of Experimental Medicine, John A. Burns School of Medicine, University of Hawaìi, 651 Ilalo Street, Honolulu, HI, 96813
| | | | - David O Carter
- Graduate Program in Molecular Biosciences and Bioengineering, University of Hawaii at Mānoa, 1650 East-West Road, Honolulu, HI, 96816
| | - Helen Turner
- Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816
| |
Collapse
|
18
|
|
19
|
Metcalf JL, Xu ZZ, Weiss S, Lax S, Van Treuren W, Hyde ER, Song SJ, Amir A, Larsen P, Sangwan N, Haarmann D, Humphrey GC, Ackermann G, Thompson LR, Lauber C, Bibat A, Nicholas C, Gebert MJ, Petrosino JF, Reed SC, Gilbert JA, Lynne AM, Bucheli SR, Carter DO, Knight R. Microbial community assembly and metabolic function during mammalian corpse decomposition. Science 2015; 351:158-62. [PMID: 26657285 DOI: 10.1126/science.aad2646] [Citation(s) in RCA: 272] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/25/2015] [Indexed: 12/22/2022]
Abstract
Vertebrate corpse decomposition provides an important stage in nutrient cycling in most terrestrial habitats, yet microbially mediated processes are poorly understood. Here we combine deep microbial community characterization, community-level metabolic reconstruction, and soil biogeochemical assessment to understand the principles governing microbial community assembly during decomposition of mouse and human corpses on different soil substrates. We find a suite of bacterial and fungal groups that contribute to nitrogen cycling and a reproducible network of decomposers that emerge on predictable time scales. Our results show that this decomposer community is derived primarily from bulk soil, but key decomposers are ubiquitous in low abundance. Soil type was not a dominant factor driving community development, and the process of decomposition is sufficiently reproducible to offer new opportunities for forensic investigations.
Collapse
Affiliation(s)
- Jessica L Metcalf
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA. Department of Pediatrics, University of California, San Diego, San Diego, CA 92037, USA.
| | - Zhenjiang Zech Xu
- Department of Pediatrics, University of California, San Diego, San Diego, CA 92037, USA
| | - Sophie Weiss
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80303, USA
| | - Simon Lax
- Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA. Institute for Genomic and Systems Biology, University of Chicago, 900 East 57th Street, Chicago, IL 606037, USA
| | - Will Van Treuren
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Embriette R Hyde
- Department of Pediatrics, University of California, San Diego, San Diego, CA 92037, USA
| | - Se Jin Song
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA. Department of Pediatrics, University of California, San Diego, San Diego, CA 92037, USA
| | - Amnon Amir
- Department of Pediatrics, University of California, San Diego, San Diego, CA 92037, USA
| | - Peter Larsen
- Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA. Biosciences Division, Argonne National Laboratory, South Cass Avenue, Argonne, IL 60439, USA
| | - Naseer Sangwan
- Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA. Biosciences Division, Argonne National Laboratory, South Cass Avenue, Argonne, IL 60439, USA. Department of Surgery, University of Chicago, A27 South Maryland Avenue, Chicago, IL 60637, USA
| | - Daniel Haarmann
- Department of Biological Sciences, Sam Houston State University, Huntsville, TX 77340, USA
| | - Greg C Humphrey
- Department of Pediatrics, University of California, San Diego, San Diego, CA 92037, USA
| | - Gail Ackermann
- Department of Pediatrics, University of California, San Diego, San Diego, CA 92037, USA
| | - Luke R Thompson
- Department of Pediatrics, University of California, San Diego, San Diego, CA 92037, USA
| | - Christian Lauber
- Nestlé Institute of Health Sciences, École Polytechnique Fédérale Lausanne, Bâtiment H, 1015 Lausanne, Switzerland
| | - Alexander Bibat
- BioFrontiers Institute, University of Colorado, Boulder, CO 80303, USA
| | | | - Matthew J Gebert
- BioFrontiers Institute, University of Colorado, Boulder, CO 80303, USA
| | - Joseph F Petrosino
- Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Sasha C Reed
- U.S. Geological Survey, Southwest Biological Science Center, Moab, UT 84532, USA
| | - Jack A Gilbert
- Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA. Institute for Genomic and Systems Biology, University of Chicago, 900 East 57th Street, Chicago, IL 606037, USA. Biosciences Division, Argonne National Laboratory, South Cass Avenue, Argonne, IL 60439, USA. Department of Surgery, University of Chicago, A27 South Maryland Avenue, Chicago, IL 60637, USA. Marine Biological Laboratory, 7 MBL St, Woods Hole, MA 02543, USA
| | - Aaron M Lynne
- Department of Biological Sciences, Sam Houston State University, Huntsville, TX 77340, USA
| | - Sibyl R Bucheli
- Department of Biological Sciences, Sam Houston State University, Huntsville, TX 77340, USA
| | - David O Carter
- Laboratory of Forensic Taphonomy, Forensic Sciences Unit, Division of Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, HI 96816, USA
| | - Rob Knight
- Department of Pediatrics, University of California, San Diego, San Diego, CA 92037, USA. Department of Computer Science and Engineering, University of California, San Diego, San Diego, CA 92037, USA.
| |
Collapse
|
20
|
Chun LP, Miguel MJ, Junkins EN, Forbes SL, Carter DO. An initial investigation into the ecology of culturable aerobic postmortem bacteria. Sci Justice 2015; 55:394-401. [DOI: 10.1016/j.scijus.2015.07.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 07/17/2015] [Accepted: 07/22/2015] [Indexed: 01/13/2023]
|
21
|
Breton H, Kirkwood AE, Carter DO, Forbes SL. The impact of carrion decomposition on the fatty acid methyl ester (FAME) profiles of soil microbial communities in southern Canada. Canadian Society of Forensic Science Journal 2015. [DOI: 10.1080/00085030.2015.1108036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
22
|
Iancu L, Carter DO, Junkins EN, Purcarea C. Using bacterial and necrophagous insect dynamics for post-mortem interval estimation during cold season: Novel case study in Romania. Forensic Sci Int 2015. [DOI: 10.1016/j.forsciint.2015.07.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
23
|
Weiss S, Carter DO, Metcalf JL, Knight R. Carcass mass has little influence on the structure of gravesoil microbial communities. Int J Legal Med 2015; 130:253-63. [DOI: 10.1007/s00414-015-1206-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 05/18/2015] [Indexed: 10/23/2022]
|
24
|
Carter DO, Metcalf JL, Bibat A, Knight R. Seasonal variation of postmortem microbial communities. Forensic Sci Med Pathol 2015; 11:202-7. [DOI: 10.1007/s12024-015-9667-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2015] [Indexed: 12/01/2022]
|
25
|
Metcalf JL, Wegener Parfrey L, Gonzalez A, Lauber CL, Knights D, Ackermann G, Humphrey GC, Gebert MJ, Van Treuren W, Berg-Lyons D, Keepers K, Guo Y, Bullard J, Fierer N, Carter DO, Knight R. A microbial clock provides an accurate estimate of the postmortem interval in a mouse model system. eLife 2013; 2:e01104. [PMID: 24137541 PMCID: PMC3796315 DOI: 10.7554/elife.01104] [Citation(s) in RCA: 196] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 09/20/2013] [Indexed: 12/13/2022] Open
Abstract
Establishing the time since death is critical in every death investigation, yet existing techniques are susceptible to a range of errors and biases. For example, forensic entomology is widely used to assess the postmortem interval (PMI), but errors can range from days to months. Microbes may provide a novel method for estimating PMI that avoids many of these limitations. Here we show that postmortem microbial community changes are dramatic, measurable, and repeatable in a mouse model system, allowing PMI to be estimated within approximately 3 days over 48 days. Our results provide a detailed understanding of bacterial and microbial eukaryotic ecology within a decomposing corpse system and suggest that microbial community data can be developed into a forensic tool for estimating PMI. DOI:http://dx.doi.org/10.7554/eLife.01104.001 Our bodies—especially our skin, our saliva, the lining of our mouth and our gastrointestinal tract—are home to a diverse collection of bacteria and other microorganisms called the microbiome. While the roles played by many of these microorganisms have yet to be identified, it is known that they contribute to the health and wellbeing of their host by metabolizing indigestible compounds, producing essential vitamins, and preventing the growth of harmful bacteria. They are important for nutrient and carbon cycling in the environment. The advent of advanced sequencing techniques has made it feasible to study the composition of this microbial community, and to monitor how it changes over time or how it responds to events such as antibiotic treatment. Sequencing studies have been used to highlight the significant differences between microbial communities found in different parts of the body, and to follow the evolution of the gut microbiome from birth. Most of these studies have focused on live animals, so little is known about what happens to the microbiome after its host dies. In particular, it is not known if the changes that occur after death are similar for all individuals. Moreover, the decomposing animal supplies nutrients and carbon to the surrounding ecosystem, but its influence on the microbial community of its immediate environment is not well understood. Now Metcalf et al. have used high-throughput sequencing to study the bacteria and other microorganisms (such as nematodes and fungi) in dead and decomposing mice, and also in the soil beneath them, over the course of 48 days. The changes were significant and also consistent across the corpses, with the microbial communities in the corpses influencing those in the soil, and vice versa. Metcalf et al. also showed that these measurements could be used to estimate the postmortem interval (the time since death) to within approximately 3 days, which suggests that the work could have applications in forensic science. DOI:http://dx.doi.org/10.7554/eLife.01104.002
Collapse
Affiliation(s)
- Jessica L Metcalf
- Biofrontiers Institute , University of Colorado at Boulder , Boulder , United States
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Meyer J, Anderson B, Carter DO. Seasonal variation of carcass decomposition and gravesoil chemistry in a cold (Dfa) climate. J Forensic Sci 2013; 58:1175-1182. [PMID: 23822087 DOI: 10.1111/1556-4029.12169] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 07/06/2012] [Accepted: 07/13/2012] [Indexed: 11/30/2022]
Abstract
It is well known that temperature significantly affects corpse decomposition. Yet relatively few taphonomy studies investigate the effects of seasonality on decomposition. Here, we propose the use of the Köppen-Geiger climate classification system and describe the decomposition of swine (Sus scrofa domesticus) carcasses during the summer and winter near Lincoln, Nebraska, USA. Decomposition was scored, and gravesoil chemistry (total carbon, total nitrogen, ninhydrin-reactive nitrogen, ammonium, nitrate, and soil pH) was assessed. Gross carcass decomposition in summer was three to seven times greater than in winter. Initial significant changes in gravesoil chemistry occurred following approximately 320 accumulated degree days, regardless of season. Furthermore, significant (p < 0.05) correlations were observed between ammonium and pH (positive correlation) and between nitrate and pH (negative correlation). We hope that future decomposition studies employ the Köppen-Geiger climate classification system to understand the seasonality of corpse decomposition, to validate taphonomic methods, and to facilitate cross-climate comparisons of carcass decomposition.
Collapse
Affiliation(s)
- Jessica Meyer
- Department of Entomology, University of Nebraska-Lincoln, 102 Entomology Hall, Lincoln, NE, 68583-0816
| | - Brianna Anderson
- Department of Entomology, University of Nebraska-Lincoln, 102 Entomology Hall, Lincoln, NE, 68583-0816
| | - David O Carter
- Department of Entomology, University of Nebraska-Lincoln, 102 Entomology Hall, Lincoln, NE, 68583-0816
- Division of Natural Sciences and Mathematics, Laboratory of Forensic Taphonomy, Chaminade University of Honolulu, 115 Wesselkamper Science Center, 3140 Waialae Avenue, Honolulu, HI, 96816
| |
Collapse
|
27
|
Anderson B, Meyer J, Carter DO. Dynamics of ninhydrin-reactive nitrogen and pH in gravesoil during the extended postmortem interval. J Forensic Sci 2013; 58:1348-1352. [PMID: 23879466 DOI: 10.1111/1556-4029.12230] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 09/05/2012] [Accepted: 09/30/2012] [Indexed: 11/28/2022]
Abstract
Estimating the postmortem interval of skeletal remains is difficult, as few tools exist to do so. To address this problem, we conducted a field experiment to measure the chemistry of swine (Sus scrofa domesticus Linnaeus) gravesoil after 1 year and 3 years postmortem. Carcasses were placed on the soil surface of a pasture during June in a cold (Dfa) climate. Significant (p < 0.05) increases in ninhydrin-reactive nitrogen, pH, total nitrogen, and nitrate in gravesoil were detected 1 year postmortem. Significant differences in gravesoil chemistry were not detected 3 years postmortem. These observations coincided with gaps in plant growth 1 year postmortem and the development of lush vegetation 3 years postmortem. We conclude that these phenomena can be used to assist the decision-making process regarding the allocation of resources during the early stages of a death investigation.
Collapse
Affiliation(s)
- Brianna Anderson
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, 68583, NE, USA
| | - Jessica Meyer
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, 68583, NE, USA
| | - David O Carter
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, 68583, NE, USA
| |
Collapse
|
28
|
Damann FE, Tanittaisong A, Carter DO. Potential carcass enrichment of the University of Tennessee Anthropology Research Facility: a baseline survey of edaphic features. Forensic Sci Int 2012; 222:4-10. [PMID: 22613367 DOI: 10.1016/j.forsciint.2012.04.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Revised: 03/05/2012] [Accepted: 04/25/2012] [Indexed: 11/29/2022]
Abstract
The University of Tennessee Anthropology Research Facility (ARF) is known for its unique contribution to forensic science as a site of human decomposition research. Studies conducted at ARF are integral in our understanding of the processes of human decomposition. As such, the authors are interested in the long-term effects of continuous human decomposition on the soil environment. Soil samples collected from within and outside the ARF were evaluated for moisture content, pH, organic content, total carbon and nitrogen content, and biomass by lipid-bound phosphorus, and total extracted DNA. Analyses revealed no significant differences (p<0.05) among the sampled areas within the facility, and yet demonstrated a possible trend toward increased levels of total N, Lipid-P, and water, suggesting an influx of high-quality nutrients into the ARF soil. Furthermore, elevated pH readings, presumably resulting from ammonification of the soil, were observed in areas of high decomposition. The negative control samples proved significantly different from nearly all samples collected within the facility, the exceptions being total carbon content and extractable DNA. These findings indicate that while landscape samples inside may be similar to themselves, they are dissimilar to those taken in a similar temperate forest biome with no recorded history of human decomposition.
Collapse
Affiliation(s)
- Franklin E Damann
- National Museum of Health and Medicine, 2460 Linden Lane, Bldg 2500, Silver Spring, MD 20910, USA.
| | | | | |
Collapse
|
29
|
Fujikawa A, Barksdale L, Higley LG, Carter DO. Changes in the morphology and presumptive chemistry of impact and pooled bloodstain patterns by Lucilia sericata (Meigen) (Diptera: Calliphoridae). J Forensic Sci 2011; 56:1315-8. [PMID: 21554312 DOI: 10.1111/j.1556-4029.2011.01800.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Bloodstain pattern analysis can be critical to accurate crime scene reconstruction. However, bloodstain patterns can be altered in the presence of insects and can confound crime scene reconstruction. To address this problem, we conducted a series of controlled laboratory experiments to investigate the effect of Lucilia sericata (Meigen) on impact bloodstains and pooled bloodstains in association with three combinations of common surfaces (linoleum/painted drywall, wood floor/wallpaper, and carpet/wood paneling). L. sericata fed from the pooled bloodstains and added insect stains through regurgitation and defecation of consumed blood. L. sericata formed defecatory trails of insect stains that indicated directionality. Defecatory stains fluoresced when viewed at 465 nm with an orange filter. These observations differed from Calliphora vicina insect stains because feeding on blood spatter was not observed and trails of insect stains were formed by L. sericata. The fluorescence of defecatory stains can be used as a method to detect insect stains and discriminate them from real bloodstains.
Collapse
Affiliation(s)
- Amanda Fujikawa
- Department of Entomology, University of Nebraska-Lincoln, 202 Entomology Hall, Lincoln, NE 68583-0816, USA
| | | | | | | |
Collapse
|
30
|
Patel NS, Larson SA, Carter DO, Drijber RA, Bailey CP. Microbial Diversity in Soil Assessed by Two Different Capillary Electrophoresis Methods. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.927.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Rhae A Drijber
- Agronomy and HorticultureUniversity of Nebraska at LincolnLincolnNE
| | | |
Collapse
|
31
|
Spicka A, Johnson R, Bushing J, Higley LG, Carter DO. Carcass mass can influence rate of decomposition and release of ninhydrin-reactive nitrogen into gravesoil. Forensic Sci Int 2011; 209:80-5. [PMID: 21277125 DOI: 10.1016/j.forsciint.2011.01.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 05/19/2010] [Accepted: 01/03/2011] [Indexed: 11/28/2022]
Abstract
To investigate the use of ninhydrin-reactive nitrogen (NRN) in gravesoil to estimate early postmortem interval (PMI), we conducted an experiment to decompose swine (Sus scrofa) carcasses of contrasting mass (∼1 kg, ∼20 kg, ∼40 kg, ∼50 kg). Carcasses were placed on the soil surface during June 2007 to monitor mass loss and the concentration of gravesoil NRN over an interval of 15 days. Carcasses of a mass ≤ 20 kg decomposed more rapidly than larger carcasses. However, 1 kg carcasses were associated with a slower release of NRN into gravesoil but a greater concentration of NRN per kg carcass (NRN(C)). We conclude that carcass mass can affect the rate of decomposition and release of NRN into gravesoil, which reflects an interaction between carcass volume and blow fly colonization. Furthermore, we conclude that neonatal carcasses require a different equation than larger carcasses when using gravesoil chemistry to estimate PMI.
Collapse
Affiliation(s)
- Ashley Spicka
- Department of Biology, Nebraska Wesleyan University, Lincoln, NE 68583-0816, USA
| | | | | | | | | |
Collapse
|
32
|
Striman B, Fujikawa A, Barksdale L, Carter DO. Alteration of expirated bloodstain patterns by Calliphora vicina and Lucilia sericata (Diptera: Calliphoridae) through ingestion and deposition of artifacts. J Forensic Sci 2010; 56 Suppl 1:S123-7. [PMID: 21039518 DOI: 10.1111/j.1556-4029.2010.01575.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bloodstain pattern analysis can provide insight into a sequence of events associated with a violent crime. However, bloodstain pattern analysis can be confounded by the feeding activity of blow flies. We conducted two laboratory experiments to investigate the relationships between Lucilia sericata (green bottle fly) and Calliphora vicina (blue bottle fly), expirated bloodstains, and pooled bloodstains on a range of surfaces (linoleum, wallpaper, textured paint). C. vicina and L. sericata changed bloodstain pattern morphology through feeding and defecation. They also deposited artifacts in rooms where blood was not present originally. Chemical presumptive tests (Hemastix(®) , phenolphthalein, leucocrystal violet, fluorescein) were not able to differentiate between insect artifacts and bloodstains. Thus, C. vicina and L. sericata can confound bloodstain pattern analysis, crime scene investigation, and reconstruction. Crime scene investigators should be aware of these fundamental behaviors, and the effects that blow flies can have on expirated and pooled bloodstain patterns.
Collapse
Affiliation(s)
- Becca Striman
- Department of Entomology, University of Nebraska-Lincoln, 68503-0816, USA
| | | | | | | |
Collapse
|
33
|
Carter DO, Yellowlees D, Tibbett M. Moisture can be the dominant environmental parameter governing cadaver decomposition in soil. Forensic Sci Int 2010; 200:60-6. [DOI: 10.1016/j.forsciint.2010.03.031] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2009] [Revised: 11/16/2009] [Accepted: 03/21/2010] [Indexed: 10/19/2022]
|
34
|
Benninger LA, Carter DO, Forbes SL. The biochemical alteration of soil beneath a decomposing carcass. Forensic Sci Int 2008; 180:70-5. [DOI: 10.1016/j.forsciint.2008.07.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2007] [Revised: 06/29/2008] [Accepted: 07/01/2008] [Indexed: 10/21/2022]
|
35
|
|
36
|
Carter DO, Yellowlees D, Tibbett M. Cadaver decomposition in terrestrial ecosystems. Naturwissenschaften 2006; 94:12-24. [PMID: 17091303 DOI: 10.1007/s00114-006-0159-1] [Citation(s) in RCA: 304] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 07/31/2006] [Accepted: 08/01/2006] [Indexed: 10/23/2022]
Abstract
A dead mammal (i.e. cadaver) is a high quality resource (narrow carbon:nitrogen ratio, high water content) that releases an intense, localised pulse of carbon and nutrients into the soil upon decomposition. Despite the fact that as much as 5,000 kg of cadaver can be introduced to a square kilometre of terrestrial ecosystem each year, cadaver decomposition remains a neglected microsere. Here we review the processes associated with the introduction of cadaver-derived carbon and nutrients into soil from forensic and ecological settings to show that cadaver decomposition can have a greater, albeit localised, effect on belowground ecology than plant and faecal resources. Cadaveric materials are rapidly introduced to belowground floral and faunal communities, which results in the formation of a highly concentrated island of fertility, or cadaver decomposition island (CDI). CDIs are associated with increased soil microbial biomass, microbial activity (C mineralisation) and nematode abundance. Each CDI is an ephemeral natural disturbance that, in addition to releasing energy and nutrients to the wider ecosystem, acts as a hub by receiving these materials in the form of dead insects, exuvia and puparia, faecal matter (from scavengers, grazers and predators) and feathers (from avian scavengers and predators). As such, CDIs contribute to landscape heterogeneity. Furthermore, CDIs are a specialised habitat for a number of flies, beetles and pioneer vegetation, which enhances biodiversity in terrestrial ecosystems.
Collapse
Affiliation(s)
- David O Carter
- School of Pharmacy and Molecular Sciences, James Cook University, Townsville, QLD 4811, Australia.
| | | | | |
Collapse
|
37
|
Tibbett M, Carter DO, Haslam T, Major R, Haslam R. A laboratory incubation method for determining the rate of microbiological degradation of skeletal muscle tissue in soil. J Forensic Sci 2004; 49:560-5. [PMID: 15171177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
A controlled laboratory experiment is described, in principle and practice, which can be used for the of determination the rate of tissue decomposition in soil. By way of example, an experiment was conducted to determine the effect of temperature (12 degrees, 22 degrees C) on the aerobic decomposition of skeletal muscle tissue (Organic Texel x Suffolk lamb (Ovis aries)) in a sandy loam soil. Measurements of decomposition processes included muscle tissue mass loss, microbial CO2 respiration, and muscle tissue carbon (C) and nitrogen (N). Muscle tissue mass loss at 22 degrees C always was greater than at 12 degrees C (p < 0.001). Microbial respiration was greater in samples incubated at 22 degrees C for the initial 21 days of burial (p < 0.01). All buried muscle tissue samples demonstrated changes in C and N content at the end of the experiment. A significant correlation (p < 0.001) was demonstrated between the loss of muscle tissue-derived C (Ct) and microbially-respired C (Cm) demonstrating CO2 respiration may be used to predict mass loss and hence biodegradation. In this experiment Q10 (12 degrees C-22 degrees C) = 2.0. This method is recommended as a useful tool in determing the effect of environmental variables on the rate of decomposition of various tissues and associated materials.
Collapse
Affiliation(s)
- Mark Tibbett
- School of Earth and Geographical Sciences, University of Western Australia, Crawley, WA 6009, Australia.
| | | | | | | | | |
Collapse
|
38
|
Carter DO, Tibbett M. Taphonomic mycota: fungi with forensic potential. J Forensic Sci 2003; 48:168-71. [PMID: 12570221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Forensic archaeologists and criminal investigators employ many different techniques for the location, recovery, and analysis of clandestine graves. Many of these techniques are based upon the premise that a grave is an anomaly and therefore differs physically, biologically, or chemically from its surroundings. The work reviewed in this communication demonstrates how and why field mycology might provide a further tool towards the investigation of scenes of crime concealed in forest ecosystems. The fruiting structures of certain fungi, the ammonia and the postputrefaction fungi, have been recorded repeatedly in association with decomposed mammalian cadavers in disparate regions of the world. The ecology and physiology of these fungi are reviewed briefly with a view to their potential as a forensic tool. This application of mycology is at an interface with forensic archaeology and forensic taphonomy and may provide a means to detect graves and has the potential to estimate postburial interval.
Collapse
Affiliation(s)
- David O Carter
- School of Pharmacy and Molecular Sciences, James Cook University, Townsville, Queensland, Australia.
| | | |
Collapse
|