Program in Cell & Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523, USA.
Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523, USA.
Forensic Sci Int. 2022 Nov;340:111425. doi: 10.1016/j.forsciint.2022.111425. Epub 2022 Aug 18.
During decomposition, flies interact with the remains to lay eggs and acquire nutrients, and in the process, they bring their microbes with them. While it is known that flies have their own unique core microbiome, it is not known if flies associated with human cadavers have a different core microbiome. Differences in the fly microbiome may influence the types of microbes transmitted from the flies to the cadaver, therefore potentially affecting assembly of the human decomposer microbiome. The first purpose of this study was to characterize the microbiome of flies associated with human cadavers by fly organ and season. This is because fly interactions with cadavers vary by season, and because it is likely that external fly organs [i.e., the labellum and tarsi] make more direct contact and are likely involved in increased mechanical transmission with the cadaver than internal organs such as the oocyte. The second purpose of this study was to determine if the fly microbes contribute to the human decomposer microbiome. To accomplish these aims, 10 human cadavers were placed outdoors across three seasons and allowed to decompose. A total of 40 flies that landed on the cadaver were collected and dissected by the labellum, tarsi, and oocyte. In addition to fly collections, samples from the cadavers were collected using a sterile swab at sites including the cheek of the face, inner cheek, bicep, torso, and anus. Overall, it was shown that flies associated with human cadavers have a similar microbiome to flies from previous studies that were not associated with human cadavers. However, there are differences in the microbiome between seasons and fly parts. We also show evidence that flies act as a microbial source to the human decomposer microbiome, which is important for understanding the ecological mechanisms of human cadaver microbial community assembly.
在分解过程中，苍蝇与遗骸相互作用以产卵并获取营养，在此过程中，它们会携带自己的微生物。虽然已知苍蝇有其独特的核心微生物组，但尚不清楚与人类尸体有关的苍蝇是否具有不同的核心微生物组。苍蝇微生物组的差异可能会影响从苍蝇传播到尸体的微生物类型，从而可能影响人体分解者微生物组的组装。本研究的首要目的是通过蝇器官和季节来描述与人体尸体有关的蝇的微生物组。这是因为苍蝇与尸体的相互作用因季节而异，而且外部苍蝇器官（即唇瓣和跗节）可能比卵等内部器官更直接地接触并参与与尸体的机械传播，因此更有可能影响苍蝇微生物组的组装。本研究的第二个目的是确定苍蝇微生物组是否有助于人体分解者微生物组。为了实现这些目标，将 10 具人体尸体放置在户外三个季节，让其分解。总共收集了 40 只降落在尸体上的苍蝇，并通过唇瓣、跗节和卵进行了解剖。除了苍蝇采集外，还使用无菌拭子从尸体的包括脸颊、内颊、二头肌、躯干和肛门在内的部位采集样本。总体而言，研究表明与人体尸体有关的苍蝇的微生物组与先前未与人体尸体有关的苍蝇的微生物组相似。但是，在季节和苍蝇部位之间，微生物组存在差异。我们还提供了证据表明苍蝇是人体分解者微生物组的微生物来源，这对于理解人体尸体微生物群落组装的生态机制很重要。
