Decomposition Of Corpses Research Articles

Effect of seasons on the decomposition by necrophagous insects of pig (Sus scrofa domesticus L.) carcasses exposed to the open air in the Sudano-guinean and Sub-sudanese zones of Côte d'Ivoire

Determining the post-mortem interval (PMI) of a corpse discovered 72 hours after death is becoming complex and imprecise in forensic medicine. It is necessary to use other investigative methods to determine the date of death. The aim of this research was to determine the impact of the seasons on the decomposition of pig corpses exposed to the open air by necrophagous insects. The research was carried out in the North (at the Botanical Garden of the Peleforo Gon Coulibaly University in Korhogo) and in the Centre (in the Bouaké region). Insects were collected directly from decomposing carcasses using a mowing net and flexible forceps for larvae and Coleoptera. Pitfall-traps were also used for collection. Diptera and Coleoptera were collected during the dry and rainy seasons in the Sudano-guinean and Sub-Sudanese zones. Chrysomya albiceps, belonging to the Calliphoridae, was the majority species. Because of its plethora of species in the two study areas, C. albiceps could be one of the main species for determining the minimum MPI in Côte d'Ivoire. Five stages of decomposition were observed in the two study zones, although a sixth stage (dry putrefaction) was observed in the Sub-sudanese zone during the harmattan period. Stratiomyidae and Piophilidae contributed to the total decomposition of carcasses during the rainy season. The Histeridae family was the richest in species. Dermestes maculatus was the richest in individuals. Carcasses in the rainy and dry seasons were respectively decomposed by an average of 97.18% in the rainy season and 84.32% in the dry season in the two study areas.

Functional redundancy in carrion decomposition by temperate forest ant communities

Abstract Scavenging of small avian corpses may provide ants with a valuable source of nutrients, a possibility poorly studied. Here, we assessed whether ants are efficient carrion‐decomposers of avian corpses in Mediterranean dehesas through an exclusion experiment comparing decomposition rates among three treatments: vertebrate exclusion, vertebrate + invertebrate exclusion and control. Treatments were applied in a paired design in bird cavities and on the ground in two zones to assess functional redundancy. Ant community was characterized by pitfall traps, and key functional traits influencing ants' presence on carrion were identified by using phylogenetic comparative methods. Carrion decomposition was influenced by the exclusion treatment, being significantly faster when ants and other invertebrates were not excluded, but not by location (cavity/ground). Vertebrates were less likely to detect baits in cavities and removed more bait mass in the most transformed zone. Twelve of 25 ant species in the community were found foraging on baits. Ant communities differed between carrion location and localities. Phylogenetic analyses revealed that the proneness of ant species to forage on carrion was unrelated to morphological or social traits, but behavioural, being higher among species foraging collectively. Our results show that ants play a functionally unique role in the decomposition of small corpses in dehesas, and particularly so in trees and less transformed pastureland. Decomposition involves different species in different microhabitats, suggesting high functional redundancy across ants. Our findings provide new insights into the role of ants as scavengers and expand our understanding of the functioning of Mediterranean communities.

16S rRNA, metagenomics and 2bRAD-M sequencing to decode human thanatomicrobiome

Microorganisms are essential in the decomposition of corpses and play a significant role in forensic science. However, previous studies have primarily focused on animal remains, specifically the gut, skin, and burial environment. Insufficient research has been conducted on the microbiota of human cadavers, especially in cases of advanced decomposition and additional tissues, resulting in a lack of relevant reference data. In this study, the microbiota of eight cadavers at different stages of decomposition were detected using 16S rRNA, metagenomic sequencing and 2bRAD-M sequencing. Nine different sites, including oral and nasal cavities, heart, liver, spleen, lung, kidney, muscle and gut, were analysed and the efficacy of these methods was evaluated. The results showed that 16S rRNA sequencing was the most cost-effective method for the study of cadavers in the early stages of decomposition, whereas for cadaveric tissues in the late stages of decomposition, 2bRAD-M could overcome host contamination more effectively than metagenomic sequencing. This paves the way for new opportunities in data retrieval and promotes in-depth investigations into the microbiota.

Validation of a new method for the detection of Ethyl glucuronide in larvae of Lucilia sericata as a marker of ante-mortem alcohol consumption

Larvae and insects are an important and alternative biological matrix in the development anpost-mortem forensic toxicology. They are very useful when conventional matrices are not available, in particular when the loss of biological fluids, due to the decomposition of corpses or to a traumatic death, occurs. The purpose of this study is to develop and validate an analytical method in Ultra High-Performance Liquid Chromatography at High Resolution Mass Spectrometry (HPLC/HR-MS) for the research and quantification of Ethyl glucuronide (EtG) on larvae. The criteria taken into consideration for the validation are linearity, quantitation limits (LOD and LLOQ), accuracy, precision, carryover, interferences and ionization suppression/enhancement. The method was shown to be linear within the tested range, with a coefficient of determination higher than 0.99. LOD was 2 pg mg−1, while LLOQ was 5 pg mg-1. Accuracy, precision and ionization/suppression enhancement fulfilled the criteria indicated in the guidelines used for the validation. The establishment and validation of this method allowed the identification of Ethyl glucuronide on the larvae of Lucilia sericata (Calliphoridae) of a subject found death in an advanced state of decomposition.

Anatomy in the painting of Rembrandt Harmenszoon van Rijn

Works of art have a substantial impact on viewers not only because of the beauty of the image but also because of the dominance of the decisive moment they express. Rembrandt Harmenszoon van Rijn managed with his group portrait The Anatomy Lesson of Dr Nicolaes Tulp to draw viewers into the scene of dissection of a body thanks to the dynamics of the painted characters. At the beginning of the 16th century, the practice of public autopsies spread throughout Europe. In 1555, King Philip II granted the Guild of Surgeons in Amsterdam the privilege of dissecting executed criminals for educational and scientific purposes. Dissections were performed once a year during the winter months to prevent rotting and decomposition of corpses, and the procedure itself often lasted several days. Dr Nicolaes Tulp performed the autopsy of a hanged convict in 1632, which Rembrandt immediately painted. With this piece, the artist presented the beginning of a new pedagogical approach to teaching anatomy. The picture represents Dr Nicolaes Tulp instructing seven onlookers as he is dissecting a hand and showing the flexor digitorum superficialis.

Bacterial bioerosion of bones is a post-skeletonisation phenomenon and appears contingent on soil burial

The post-mortem changes that take place during the decomposition of corpses are extremely complex and have been the subject of considerable research because of their obvious importance to forensic scientists. Considerable advances have been made in understanding the interplay of the various factors that influence decay, and the timescales over which they operate. Similarly, changes to the chemistry and microstructure of bones, post-skeletonisation, are of intense interest to archaeological scientists and the past few decades has seen tremendous advances in our understanding of how post-burial diagenesis may impact endogenous evidence within ancient and fossil bones.In recent years it has been postulated that the early stages of putrefaction of a body have a profound effect on the microstructure of bones and that these changes persist over archaeological timescales. One of the most important mechanisms for post-depositional degradation of bones is bacterial bioerosion. The question of the origin of the bacteria responsible, and why some archaeological bones are bioeroded while others are not, has received considerable attention in recent years. The assertion by some that the bacteria originate in the gut, and infiltrate bone tissues via the vascular network during the putrefactive stages of decay, has led to a number of claims as to what can be inferred by the presence, or absence, of bacterial tunnelling in bones. These claims include evidence for human mummification, identification of stillborns and infanticide, and animal sacrifices.Here we present evidence from SEM histological examinations of bones from field experiments using intact pig carcasses interred in brick lined tombs; a forensic case of a body exposed on a concrete floor for ten years; together with de-fleshed bones from freshly slaughtered cows buried in tropical soils for 1-10 years. None of the decomposing pig carcasses, nor the human corpse, showed any signs of bacterial tunnelling in their bones. By contrast, the de-fleshed bones buried directly in soils showed evidence of tunnelling after only one year and considerable tunnelling after ten years. Our results cannot support the “enteric hypothesis” that the bone tunnelling microorganisms that degrade buried bones originate in the gut microbiota but rather suggest that gut bacteria play no role in the post-mortem degradation of buried bones. It therefore follows that no conclusions about post-mortem treatment of human or animal corpses can be deduced from the presence, or absence, of microbial tunnelling in skeletonised remains from an archaeological (or forensic) context.

USE OF GEOPHYSICAL TECHNIQUES FOR ANALYSIS OF TRACE METALS IN A CEMETERY UNSATURATED SOIL ZONE

The purpose of this research was to apply two geophysical methods [Resistivity Imaging Technique (RI) and Inductive Electromagnetic Technique (EM-31)] to verify this tool’s efficiency in locating in subsurface contamination plumes and/or metal ions released by decomposition of corpses and their shells at Necrópole Nossa Senhora Aparecida, Piedade, SP.
 This research was carried out from October 2015 to September 2016. In the first phase, we used the Resistivity Imaging technique and later we applied the electromagnetic technique. This period between one investigation and another was useful to verify if anomalies changed during that period. Results showed that localized anomalies did not move and that results of both methodologies were similar, considering limitations of each technique.

Corpse decay of wild animals leads to the divergent succession of nrfA-type microbial communities.

Animal carcasses introduce large amounts of nitrates and ammonium into the soil ecosystem. Some of this ammonium is transformed from nitrite through the nrfA-type microbial community. However, it is unclear how nrfA-type microorganisms respond to the decomposition of corpses. This study applied high-throughput sequencing to characterize the ecological succession of nrfA-type microbial communities in grassland soil. Our results showed that Cyclobacterium and Trueperella were the predominant genera for nrfA-type communities in soil with a decomposing corpse (experimental group), while Cyclobacterium and Archangium were dominant in soil without a corpse (control group). The alpha diversity indexes and the resistance and resilience indexes of the microbial communities initially increased and then decreased during decomposition. Compared with the control group, nrfA-encoding community structure in the experimental group gradually became divergent with succession and temporal turnover accelerated. Network analysis revealed that the microbial communities of the experimental group had more complex interactions than those of the control groups. Moreover, the bacterial community assembly in the experimental group was governed by stochastic processes, and the communities of the experimental group had a weaker dispersal capacity than those of the control group. Our results reveal the succession patterns of the nrfA-type microbial communities during degradation of wild animal corpses, which can offer references for demonstrating the ecological mechanism underlying the changes in the nrfA-type microbial community during carcass decay. KEY POINTS: • Corpse decay accelerates the temporal turnover of the nrfA-type community in soil. • Corpse decay changes the ecological succession of the nrfA-type community in soil. • Corpse decay leads to a complex co-occurrence pattern of the nrfA-type community in soil.

Specific VOC-Profile of Decomposed Sasquatch Remains

A method using a thermal desorber combined with a gas chromatograph coupled to a mass spectrometer was proposed to identify the volatile organic compounds (VOCs) released in decomposed Sasquatch remains. It is known that specific VOCs are generated during the decomposition of Sasquatch and animal corpses that allow us to determine to which species the remains correspond, and the time elapsed since their dead. We found a combination of 8 compounds (ethyl propionate, propyl propionate, propyl butyrate, ethyl pentanoate, pyridine, diethyl disulfide, methyl (methylthio) ethyl disulfide and 3-methylthio1-propanol) that led to the distinction of Sasquatch remains from another animal remains. These markers would allow a more efficiently training of cadaver dogs or portable detection devices could be developed.

Delineation of necroleachate pathways using electrical resistivity tomography (ERT): Case study on a cemetery in Brazil

Cemeteries can be considered as potential sources of soil and groundwater contamination in burial sites where there is no collection and treatment system for necroleachate, an effluent rich in organic matter and inorganic elements produced during the decomposition of corpses. Brazilian cemeteries are mostly located in the interior of cities, where collective or family deposits with the absence of necroleachate collection devices predominates. The tropical climate, the recurrence, and the distribution of corpses, combined with soil permeability, are decisive elements in the percolation and distribution of necroleachate in the subsurface. An important tool for the diagnosis and evaluation of organic and inorganic contamination in soil and shallow aquifers is geophysics, through research methods related to the contrast of physical properties in the presence of this type of contaminant. This research consists of a geophysical investigation in a medium-sized cemetery in the southeastern Brazil, using the DC resistivity method using three different electrodes arrays: Wenner, Schlumberger and Dipole-Dipole. Additionally, results were combined with the history of burials in the 5 years prior to the geophysical study. The 2D inversion models confirm the presence of low resistivity anomalies related to the presence of ionic compounds. 3D visualization models with results of the three acquisition arrays are compared to the amount of burial by compartmentalized areas of the cemetery, which clearly reveals a relationship of areas with high and recent recurrence of burials and areas of low resistivity in depth. The results do not present significant differences between arrays, with similarities in terms of location and dimension of the most significant areas of low resistivity.

Perubahan Kadar Nitrogen Total Pada Tanah Sebagai Alternatif Estimasi Post-Mortem Interval

AbstractForensic taphonomy is a branch of forensic science which in its application uses processes related to the decomposition of corpses and uses soil evidence to estimate post-mortem interval (PMI) or post burial. Soil has evidential value because it contains minerals, plants and animal materials that are useful for characterization. This research was conducted by analyzing soil characteristics, namely soil pH and soil moisture and total nitrogen content in soil samples taken from under rabbit carcasses that were placed on the soil surface, buried 25 cm and 50 cm at each decomposition stage. The results obtained showed significant differences at each stage of decomposition and laying of the carcasses.

Carcass decomposition influences the metabolic profiles and enriches noxious metabolites in different water types by widely targeted metabolomics

Carcass decomposition could be considered as a common phenomenon in nature. However, during degradation processes, animal carcasses produce many toxic and harmful metabolites, posing potential ecological risks to water safety, thereby threatening human health. However, the metabolites produced by decomposition of animal corpses are not well understood. In this study, building on our previous baseline study of microbial community between the experimental groups (with animal carcasses) and control groups (without carcasses), the samples at the ultimate stage (19th day) of carcass decomposition were chosen to investigate the metabolic profiles and uncover the relationships between water quality, microbes and noxious metabolites in two types of water (Yellow River water and tap water) using fish as animal model by widely targeted metabolomics. Our results showed amino acid metabolomics, indole and its derivatives, and pyridine and pyridine derivatives mainly occurred in the corpse groups, suggesting that these metabolites are markers of carcass decomposition. And some noxious metabolites (e.g., polyamine, amines, and benzene and substituted derivatives) highly associated with carcass decomposition, which revealed new insights into how to investigate the hazard materials in water. And these noxious metabolites in the corpse groups were even increased 214543-fold in average compared with the control groups. Meanwhile, treatment was the most important factor affecting the water metabolites while microbiome contributed a small proportion to the metabolic profiles. Several opportunistic pathogenic genera Comamonas, Bacteriodes and Alcaligenes co-occurred most frequently with several kinds of polyamines and amines while some dominant genera Rhodoferax, Delftia and Brevundimonas had significant positive relationships with specific benzene and substituted derivatives. This work demonstrates that carcass decomposition causes water quality deterioration by producing various toxic metabolites, thus providing new insights into noxious metabolites when exposed to animal carcasses in aquatic environment.

Forensic taphonomy: Characterization of the gravesoil chemistry using a multivariate approach combining chemical and volatile analyses

Soil thanatochemistry, defined as the study of the chemical changes occurring during the decomposition of buried corpses, is a young and inadequately documented field of research. In this study, we aim to determine the effects of decomposition on soil physico-chemical properties by combining pedological, chemical, and volatile analyses of soils surrounding buried animals. We examined chemical and volatile changes over time occurring throughout the soil column in two common soil-texture types (sandy loam and loam). We buried dead rats and let them decompose for two months. During their excavations, we characterized the physico-chemical conditions of three soil layers above the rats and one layer below, including (1) pH, dry matter, and electrical conductivity, (2) organic carbon and total nitrogen, (3) bioavailable nutrients (K, Na, Mg, Ca, and P), and (4) volatile organic compounds. Multivariate analyses (permMANOVA) revealed that a decaying rat is associated with changes in soil chemical characteristics in both soil types. However, the observed changes were not homogenous throughout the soil columns. Conditions in soil layers nearest the cadavers changed most during decomposition. We generated a predictive model by combining chemical and volatile analyses (10 % error rate), allowing us to identify key gravesoil indicators that could be used to reveal the former existence of a buried corpse in loam and sandy loam (indicators in order of importance): organic carbon, calcium, pH, conductivity, dimethyl-disulfide, and nitrogen.

Análise da atividade cemiterial na qualidade da água no município de Presidente Prudente-SP

Os cemitérios são essenciais à sociedade e precisam ser analisados a fim de que possam proporcionar uma relação harmoniosa com o meio ambiente, minimizando os impactos que essa atividade pode gerar. De acordo com a potencialidade de contaminação dos cemitérios, e as alterações nos meios físico e biótico, é atribuída à atividade cemiterial um potencial impacto ambiental. O líquido liberado pela decomposição dos cadáveres, o necrochorume, é a principal causa da poluição ambiental. O presente trabalho teve como objetivo analisar a qualidade da água superficial próximo aos cemitérios do município de Presidente Prudente- SP. As análises físico-químicas e microbiológicas foram executadas em amostras de água superficiais, em pontos próximos dos cemitérios. A partir dos resultados obtidos foi possível identificar que os cemitérios do município podem proporcionar impactos ambientais negativos ao meio ambiente, causando contaminação dos recursos hídricos superficiais.

Connecting Existing Cemeteries Saving Good Soils (for Livings)

Background: Urban sprawl consumes and degrades productive soils worldwide. Fast and safe decomposition of corpses requires high-quality functional soils, and land use which competes with both agriculture and buildings. On one hand, cremation does not require much land, but it has a high energy footprint, produces atmospheric pollution, and is unacceptable to some religious communities. On the other hand, as exhumations are not practiced, “green burials” require more surface area than current burial practices, so a new paradigm for managing land use is required. Conclusions: In this paper, we propose a concept for ‘green belt communalities’ (i.e., ecological corridors with multiple, yet flexible, uses and services for future generations). With the expansion of urban centers, ecological corridors gradually disappear. Cemeteries for burial plots preclude alternative uses of the land for a long time. By combining these two aspects (need for connectivity and land take imposed by cemeteries), two positive results can be achieved: protecting memories of the past and connecting ecosystems with multiple-use corridors. This new paradigm works best in flat or hilly terrain where there are already several urban agglomerations that contain traditional cemeteries. Stakeholders who might consider this concept are local administrators, planners, and the communities of individuals who share specific beliefs on burial systems.

Succession of oral microbiota community as a tool to estimate postmortem interval

The establishment of postmortem interval is one of the most important aspects of forensic expertise. Microbes may provide a novel way to estimate the postmortem intervals in order to avoid many of these limitations. The oral cavity harbors one of the most diverse microbiomes that play a key role in the decomposition of corpses. In this study, the oral bacterial community showed obvious changes in relative abundance during the process of mice decomposition. Meanwhile, at different taxonomic levels, specific bacteria were found to be significantly correlated with the postmortem interval. Linear regression models between relative abundance and the postmortem interval were constructed. Among these species, Gamma-proteobacteria and Proteus were the best ones that can be used to infer the postmortem interval, especially late postmortem interval. Therefore, we suggest that succession of oral microbial community can be developed as a forensic tool for estimating the postmortem interval.

Research Progress of Aquatic Corpse Decomposition and Postmortem Submersion Interval Estimation.

Human corpses can be found in a variety of aquatic environments. The decomposition of corpses in aquatic environments is different from those on land. A large number of factors influence the decomposition process in water, therefore postmortem submersion interval （PMSI） is difficult to estimate. To date, while studies on aquatic corpses are obviously fewer than those on terrestrial corpses, there are many problems in practical work. This review summarizes the stages and influencing factors of aquatic corpse decomposition, and introduces the relevant research progress of PMSI estimation based on decomposition stages, postmortem phenomena, aquatic insects, biofilm, and physical and chemical methods, in order to provide reference for aquatic decomposition researches and practices.

COMPLEX MICROBIAL-ZOOLOGICAL CHARACTERISTICS OF THE POSTMORTEM PERIOD DURING THE PRODUCTION OF FORENSIC MEDICAL EXAMINATION

Aim. To provide a complex microbial-zoological characteristics of the postmortem period. Materials and methods: Microbiological studies: material for examination was isolated from three species of animals, including domestic pig (Sus scrofa domesticus) weighing 50-100 kg, domestic chickens (burnt and unburnt) (Gallus gallus) weighing 1.5–2 kg and house mice (Mus musculus) weighing 80 g. In addition, human corpses, bone remains and over 1000 microorganism isolates were investigated. Entomological studies: material for examination was isolated from human corpses and their bone remains (17), pigs (10), chickens (32), representatives of the mammalian class (20), 79 objects in total. 32394 insects were investigated. Studies of injuries caused by certain vertebrates: 34 human corpses and their bone remains were examined. Results. Main trends in the microbial decomposition of dead bodies have been determined, which are of great practical significance for the diagnosis of the remoteness of death during the course of forensic medical examination. General characteristics of the process of corpse decomposition by necrophilous insects are given. The effect of the thermal factor (high temperature) on the microbiological and entomological features of corpse decomposition has been established. Anatomical, topographical and morphological features of injuries caused by some vertebrates have been determined. Conclusion. Our results prove the existence of a close relationship between the objects of forensic medical examination and the microbial processes that occur during the decomposition of corpses and under the action of insects and scavengers.

Where Did They Come from-Multi-Drug Resistant Pathogenic Escherichia coli in a Cemetery Environment?

Human burial in cemeteries facilitates the decomposition of corpses without posing a public health danger. However, the role of cemeteries as potential environmental reservoirs of drug-resistant pathogens has not been studied. Thus, we investigated cemeteries as potential environmental reservoirs of multi-drug resistant (MDR) pathogenic Escherichia coli. E. coli isolates were obtained from water samples (collected from surface water bodies and boreholes in three cemeteries) after isolation using the Colilert® 18 system. Pathogenic potentials of the isolates were investigated using real-time polymerase chain reactions targeting seven virulence genes (VGs) pertaining to six E. coli pathotypes. The resistance of isolates to eight antibiotics was tested using the Kirby–Bauer disc diffusion method. The mean E. coli concentrations varied from <1 most probable number (MPN)/100 mL to 2419.6 MPN/100 mL with 48% of 100 isolates being positive for at least one of the VGs tested. Furthermore, 87% of the isolates were resistant to at least one of the antibiotics tested, while 72% of the isolates displayed multi-drug resistance. Half of the MDR isolates harboured a VG. These results suggest that cemeteries are potential reservoirs of MDR pathogenic E. coli, originating from surrounding informal settlements, which could contaminate groundwater if the cemeteries are in areas with shallow aquifers.

A decomposição cadavérica e as dificuldades de gestão dos espaços funerários

Compreender a decomposição cadavérica é fundamental na prática forense, nomeadamente para a estimativa do intervalo pós-morte (PMI1), sendo também relevante na gestão funerária, tarefa cada vez mais difícil devido à sobrelotação dos cemitérios dos grandes centros populacionais. Aplicando os princípios da Tafonomia a uma amostra de 35 inumações (18 indivíduos do sexo masculino e 17 do feminino, todos adultos; PMI entre 3 e 83 anos) de dois cemitérios municipais da Figueira da Foz, analisaram-se os seguintes parâmetros: decomposição cadavérica, preservação esquelética, PMI, tipo e composição da sepultura, idade e sexo do indivíduo. Este estudo mostrou que houve variações no desenrolar do processo de decomposição dos cadáveres analisados, dos quais 14 sofreram fenómenos de preservação (2 mumificaram e 10 saponificaram). A decomposição depende do PMI, mas esta relação é variável e não linear, tornando impossível prever o estado de decomposição do cadáver apenas com base no PMI de forma a programar devidamente as exumações/trasladações necessárias à gestão dos espaços funerários. Tornou-se evidente que o prazo legal de 3 anos é insuficiente para a rotação das sepulturas. Observou-se também que o tipo de sepultura, o vestuário e a presença de fralda tiveram influência na decomposição dos cadáveres.