Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Ave, Windsor, Ontario N9B 3P4, Canada.
Canada Centre for Inland Waters, Environment and Climate Change Canada, 867 Lakeshore Rd, Burlington, Ontario L7R 4A6, Canada.
Sci Total Environ. 2022 Feb 10;807(Pt 3):150996. doi: 10.1016/j.scitotenv.2021.150996. Epub 2021 Oct 14.
The introduction and proliferation of pathogenic organisms in aquatic systems is a serious global issue that consequently leads to economic, financial, and health concerns. Health and safety related to recreational water use is typically monitored through water quality assessments that are outdated and can be misleading. These traditional methods focus on broad taxa groups, provide no insight into the active community or source of contamination, and the sediment compartments (bed and suspended) are often overlooked. To bridge this knowledge gap, our study aimed to 1) examine the metatranscriptome of the microbial community associated with suspended sediment (SS) in freshwater systems; 2) explore the influence of SS in tributaries to the littoral zone of the receiving lake; and 3) compare the SS fraction with previously reported nearshore bed sediment data. Samples were collected seasonally from Lake St. Clair and Lake Erie. Beaches in this region are influenced by both agriculture runoff and continued urban expansion. Results show that both adjacent tributary and beach SS have similar microbial functional diversity and are strongly correlated by site and season. We identified expression of transcripts encoding sequences with similarities to genes involved in nine bacterial infectious disease pathways, including legionellosis (sdhA) and Vibrio cholerae pathogenesis. According to MG-RAST gene categories, lake samples typically showed higher overall expression (p < 0.05) of transcripts with similarities to genes involved in infectious disease pathways compared to the tributaries, with summer upregulated (p < 0.05) compared to fall. Our data suggests SS acts as a strong vector for pathogen transport, making this facet an important area for further research as it pertains to human health regarding recreational water use. To our knowledge, this work is the first to investigate SS in aquatic microbial communities using metatranscriptomic analyses and has significant potential to help address growing issues of microbial contamination impacting freshwater security.
水生系统中病原生物的引入和扩散是一个严重的全球性问题，因此会引发经济、财务和健康方面的关注。与娱乐用水相关的健康和安全通常通过水质评估来监测，但这些传统方法已经过时，并且可能具有误导性。这些传统方法侧重于广泛的分类群，无法深入了解活跃的群落或污染来源，并且往往忽略了沉积物（床和悬浮）。为了弥补这一知识空白，我们的研究旨在：1）检查与淡水系统悬浮沉积物（SS）相关的微生物群落的宏转录组；2）探索 SS 对受纳湖滨浅水区支流的影响；3）将 SS 部分与之前报道的近岸床沉积物数据进行比较。本研究从安大略省的苏必利尔湖和伊利湖采集了季节性样本。该地区的海滩受到农业径流和城市扩张的影响。结果表明，相邻的支流和海滩 SS 具有相似的微生物功能多样性，并且主要受地点和季节的强烈影响。我们鉴定出了与 9 种细菌性传染病途径相关的基因编码序列相似的转录本的表达，包括军团病（sdhA）和霍乱弧菌发病机制。根据 MG-RAST 基因分类，与支流相比，湖泊样本通常表现出更高的与传染病途径相关基因相似的转录本的总体表达（p < 0.05），夏季的表达上调（p < 0.05）高于秋季。我们的数据表明 SS 是病原体传播的强大载体，因此这一方面是进一步研究的重要领域，因为它涉及到人类健康与娱乐用水相关的问题。据我们所知，这项工作是首次使用宏转录组分析研究水生微生物群落中的 SS，并且具有很大的潜力来帮助解决影响淡水安全的微生物污染问题。
