ABSTRACT

Environmental DNA (eDNA) offers a new avenue for investigating changes in the water microbial community associated with faecal contamination. Faeces in drinking water might include pathogens, which result in serious waterborne diseases in humans. Therefore, drinking water requires comprehensive information about microbial diversity that comes from faecal contamination of different sources to reduce the risk of gastrointestinal diseases. Here, we investigated the microbial diversity of water and faecal samples at 15 recreational campgrounds in New Zealand. In total, 42 faecal (two rabbits, seven ducks, seven ruminants, seven passerines, nine possum and ten Pukeko) and 75 water (37 intakes and 38 taps) samples were analysed using 16S rRNA metabarcoding. Our results suggested that water samples harbour a higher microbial diversity than faeces. Canonical correspondence analysis of bacterial communities and NeighborNet tree of recognised pathogens showed clustering of samples from similar sources. Phylogenetic analyses showed evidence for the presence of Arcobacter and Sulfurospirillum and indicator organisms Escherichia and enterococci in water, while Campylobacter was mainly found in faeces. These findings provide novel insights toward understanding the quality of drinking water and allow future use for the identification of faecal contamination in water.

摘要

环境 DNA (eDNA) 为研究与粪便污染相关的水微生物群落变化提供了新途径。饮用水中的粪便可能含有病原体，会导致人类严重的水传播疾病。因此，饮用水需要有关来自不同来源的粪便污染的微生物多样性的全面信息，以降低胃肠道疾病的风险。在这里，我们调查了新西兰 15 个休闲露营地的水和粪便样本的微生物多样性。总共使用 16S rRNA 元条形码分析了 42 份粪便（两只兔子、七只鸭子、七只反刍动物、七只雀鸟、九只负鼠和十只 Pukeko）和 75 份水（37 次摄入和 38 次水龙头）样本。我们的结果表明，水样比粪便含有更高的微生物多样性。细菌群落的规范对应分析和已识别病原体的 NeighborNet 树显示了来自相似来源的样本的聚类。系统发育分析表明存在Arcobacter和Sulfurospirillum以及指示生物埃希氏菌和肠球菌在水中，而弯曲杆菌主要存在于粪便中。这些发现为了解饮用水的质量提供了新的见解，并允许未来用于识别水中的粪便污染。