Exploring the value of microorganisms in the appendix for inferring postmortem interval in Sprague-Dawley rats using high-throughput sequencing

作者全名："Li, Weihan; Xing, Yu; Gan, Li; Peng, Wenli; Deng, Shixiong"

作者地址："[Li, Weihan; Xing, Yu; Gan, Li; Peng, Wenli; Deng, Shixiong] Chongqing Med Univ, Dept Forens Med, Chongqing, Peoples R China; [Deng, Shixiong] Chongqing Med Univ, Dept Forens Med, 1 Yixueyuan Rd, Chongqing 400016, Peoples R China"

通信作者："Deng, SX (通讯作者)，Chongqing Med Univ, Dept Forens Med, 1 Yixueyuan Rd, Chongqing 400016, Peoples R China."

来源：JOURNAL OF FORENSIC SCIENCES

ESI学科分类：CLINICAL MEDICINE

WOS号：WOS:000888130800001

JCR分区：Q3

影响因子：1.6

年份：2022

卷号：　

期号：　

开始页：　

结束页：　

文献类型：Article; Early Access

关键词：appendiceal flora; Illumina NovaSeq sequencing; legal medicine; postmortem interval; random forest algorithm; regression model

摘要："Various microorganisms play an important role in daily functions in the body and continue to flourish after death. Our prior investigation using frozen cadavers revealed that the appendix, rather than the transverse colon, was a superior sampling site for intestinal bacteria because the appendiceal flora had higher diversity than that in the transverse colon in the majority of experimental periods after death. We sought to explore out more about whether the appendicular flora is significantly related to postmortem interval (PMI) at natural temperatures following the host's death. In this work, we employed high-throughput sequencing to evaluate the contents of rats' appendices within 2 weeks after death and then utilized the random forest algorithm to build a PMI prediction model after completing basic visual analyses on the sequencing data. The findings revealed that Firmicutes was the absolute dominant species of appendicular flora; alpha-diversity of appendix flora first increased and then decreased, with the highest point appearing at 36 h after death; and the primary metabolic functions were carbohydrate metabolism, amino acid metabolism, as well as cofactors and vitamin metabolism. Finally, a random forest regression model for PMI prediction was built by the training data at the family level, with the mean absolute error of 10.27 h for prediction within 14 days postmortem, and the test set data subsequently proved the model's reliability. Changes in appendicular flora were strongly related to the PMI following rats' deaths, so we have reason to believe that the appendicular flora is valuable in predicting PMI."

基金机构：Natural Science Foundation of Chongqing [cstc2021jcyj- msxmX0485]

基金资助正文："Natural Science Foundation of Chongqing, Grant/Award Number: cstc2021jcyj- msxmX0485"