Lang Jennifer M, Erb Racheal, Pechal Jennifer L, Wallace John R, McEwan Ryan W, Benbow Mark Eric
Department of Biology, University of Dayton, Dayton, OH 45469-2320, USA.
Department of Biology, Millersville University, Millersville, PA 17551, USA.
Microorganisms. 2016 Jan 4;4(1):1. doi: 10.3390/microorganisms4010001.
Biofilms are a ubiquitous formation of microbial communities found on surfaces in aqueous environments. These structures have been investigated as biomonitoring indicators for stream heath, and here were used for the potential use in forensic sciences. Biofilm successional development has been proposed as a method to determine the postmortem submersion interval (PMSI) of remains because there are no standard methods for estimating the PMSI and biofilms are ubiquitous in aquatic habitats. We sought to compare the development of epinecrotic (biofilms on Sus scrofa domesticus carcasses) and epilithic (biofilms on unglazed ceramic tiles) communities in two small streams using bacterial automated ribosomal intergenic spacer analysis. Epinecrotic communities were significantly different from epilithic communities even though environmental factors associated with each stream location also had a significant influence on biofilm structure. All communities at both locations exhibited significant succession suggesting that changing communities throughout time is a general characteristic of stream biofilm communities. The implications resulting from this work are that epinecrotic communities have distinctive shifts at the first and second weeks, and therefore the potential to be used in forensic applications by associating successional changes with submersion time to estimate a PMSI. The influence of environmental factors, however, indicates the lack of a successional pattern with the same organisms and a focus on functional diversity may be more applicable in a forensic context.
生物膜是在水生环境中的表面发现的无处不在的微生物群落结构。这些结构已被作为河流健康状况的生物监测指标进行研究，在此被用于法医学的潜在用途。生物膜的演替发展已被提议作为确定尸体死后浸水间隔时间（PMSI）的一种方法，因为目前尚无估算PMSI的标准方法，且生物膜在水生栖息地中普遍存在。我们试图通过细菌自动核糖体基因间隔区分析，比较两条小溪中尸体上的（家猪尸体上的生物膜）和石头上的（无釉瓷砖上的生物膜）群落的发展情况。即使与每个溪流位置相关的环境因素也对生物膜结构有显著影响，但尸体上的群落与石头上的群落仍有显著差异。两个位置的所有群落都表现出显著的演替，这表明随着时间推移群落的变化是溪流生物膜群落的一个普遍特征。这项工作的意义在于，尸体上的群落在第一周和第二周有明显变化，因此有可能通过将演替变化与浸水时间相关联来估算PMSI，从而用于法医应用。然而，环境因素的影响表明，缺乏相同生物体的演替模式，在法医背景下关注功能多样性可能更适用。
