病毒是生物学上最丰富的实体,可能是水中粪便污染物的理想指标。人为活动引发了河流生态系统的剧烈变化,导致化学和生物属性发生重大变化。这里,我们评估了使用crAssphage作为南非河流粪便污染指标的可行性。猎枪分析显示这些河流中存在多种crassphage病毒,受到化学和生物污染的影响。总的来说,与原始地点相比,受污染地点的这些病毒的多样性和相对丰度更高。与粪便大肠杆菌计数相反,在原始河流中检测到crAssphage序列,支持上述标记可能是粪便污染的更准确指标的断言。我们的数据表明存在不同的假定宿主,其中包括门细菌的成员,Pseudomonadota,Verrucomicrobiota,还有Bacillota.系统发育分析揭示了新的亚家族,这表明河流可能藏有不同且无特征的crassphage进化枝。这些数据提供了关于多样性的第一个见解,分布,以及crassphage在河流中的功能作用。一起来看,结果支持crAssphage作为水质监测的可行标记的潜在应用。重要河流支持大量人口并提供重要的生态系统服务。尽管应用了粪便大肠杆菌测试和其他标记,我们缺乏快速和可重复的方法来确定河流中的粪便污染。即使在粪便指示细菌(FIB)被认为不存在或低于大肠杆菌的调节水平之后,也有水传播的病毒暴发的报道。这表明需要开发和应用改进的水生生态系统污染物指标。这里,我们评估了crAssphage作为两条南非河流粪便污染指标的可行性。我们评估了丰度,分布,以及通过FIB分析预测原始或污染的地点中这些病毒的多样性。我们证明crAssphage是粪便污染的理想和敏感标记,并描述了crAss样噬菌体的新进化枝。我们的数据中没有已知的类似cr的亚家族,这表明这些病毒的多样性可能反映了地理局部性和依赖性。
Viruses are the most biologically abundant entities and may be ideal indicators of fecal pollutants in water. Anthropogenic activities have triggered drastic ecosystem changes in rivers, leading to substantial shifts in chemical and biological attributes. Here, we evaluate the viability of using the presence of crAssphage as indicators of fecal contamination in South African rivers. Shotgun analysis revealed diverse crAssphage viruses in these rivers, which are impacted by chemical and biological pollution. Overall, the diversity and relative abundances of these viruses was higher in contaminated sites compared to pristine locations. In contrast to fecal coliform counts, crAssphage sequences were detected in pristine rivers, supporting the assertion that the afore mentioned marker may be a more accurate indicator of fecal contamination. Our data demonstrate the presence of diverse putative hosts which includes members of the phyla Bacteroidota, Pseudomonadota, Verrucomicrobiota, and Bacillota. Phylogenetic analysis revealed novel subfamilies, suggesting that rivers potentially harbor distinct and uncharacterized clades of crAssphage. These data provide the first insights regarding the diversity, distribution, and functional roles of crAssphage in rivers. Taken together, the results support the potential application of crAssphage as viable markers for water quality monitoring. IMPORTANCE Rivers support substantial populations and provide important ecosystem services. Despite the application of fecal coliform tests and other markers, we lack rapid and reproducible approaches for determining fecal contamination in rivers. Waterborne viral outbreaks have been reported even after fecal indicator bacteria (FIB) were suggested to be absent or below regulated levels of coliforms. This indicates a need to develop and apply improved indicators of pollutants in aquatic ecosystems. Here, we evaluate the viability of crAssphage as indicators of fecal contamination in two South African rivers. We assess the abundance, distribution, and diversity of these viruses in sites that had been predicted pristine or contaminated by FIB analysis. We show that crAssphage are ideal and sensitive markers for fecal contamination and describe novel clades of crAss-like phages. Known crAss-like subfamilies were unrepresented in our data, suggesting that the diversity of these viruses may reflect geographic locality and dependence.