A microbial clock provides an accurate estimate of the postmortem interval in a mouse model system.
A microbial clock provides an accurate estimate of the postmortem interval in a mouse model system.
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DOI：
10.7554/elife.01104
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发表时间：
2013-10-15
期刊：
影响因子：
7.7
通讯作者：
Knight R
中科院分区：
文献类型：
--
作者：
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
确定死亡时间在每一次死亡调查中都是至关重要的，但现有的技术容易受到一系列错误和偏见的影响。例如，法医昆虫学被广泛用于评估死后间隔(PMI)，但误差可能从几天到几个月不等。微生物可能为估计PMI提供了一种新的方法，避免了许多这些限制。在这里，我们展示了死后微生物群落的变化是戏剧性的、可测量的和可重复的，在小鼠模型系统中，允许在大约3天内在48天内估计PMI。我们的结果提供了对腐烂身体系统中细菌和微生物真核生态的详细了解，并表明微生物群落数据可以发展为估计PMI的法医工具。DOI：http://dx.doi.org/10.7554/eLife.01104.001我们的身体--特别是我们的皮肤、唾液、口腔内壁和胃肠道--是各种细菌和其他微生物的家园，这些微生物被称为微生物群。虽然其中许多微生物的作用尚未确定，但已知它们通过代谢不可消化的化合物、产生必要的维生素和防止有害细菌的生长来促进宿主的健康和福祉。它们对环境中的营养和碳循环很重要。先进测序技术的出现使研究这种微生物群落的组成并监测它如何随时间变化或对抗生素治疗等事件做出反应成为可能。测序研究被用来强调在身体不同部位发现的微生物群落之间的显著差异，并跟踪肠道微生物群自出生以来的演变。这些研究大多集中在活的动物身上，所以对宿主死亡后微生物群会发生什么知之甚少。特别是，还不知道死后发生的变化是否对所有人都是相似的。此外，正在分解的动物为周围的生态系统提供养分和碳，但它对周围环境中微生物群落的影响尚不清楚。现在，梅特卡夫等人。在48天的时间里，他们使用高通量测序技术研究了死亡和腐烂小鼠体内的细菌和其他微生物(如线虫和真菌)，以及它们下面的土壤中的细菌和其他微生物。这些变化是显著的，而且在身体中也是一致的，身体中的微生物群落影响土壤中的微生物群落，反之亦然。Metcalf等人。这些测量还表明，这些测量可以用来估计死后间隔(自死亡以来的时间)大约在3天内，这表明这项工作可能在法医科学中有应用。DOI：http://dx.doi.org/10.7554/eLife.01104.002
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