Abstract：
In recent years, the frequency of nosocomial infections has increased. Hospital water systems support the growth of microbes, especially opportunistic premise plumbing pathogens. In this study, planktonic prokaryotic communities present in water samples taken from hospital showers and hand basins, collected over three different sampling phases, were characterized by 16S rRNA gene amplicon sequencing. Significant differences in the abundance of various prokaryotic taxa were found through univariate and multivariate analysis. Overall, the prokaryotic communities of hospital water were taxonomically diverse and dominated by biofilm forming, corrosion causing, and potentially pathogenic bacteria. The phyla Proteobacteria, Actinobacteriota, Bacteroidota, Planctomycetota, Firmicutes, and Cyanobacteria made up 96% of the relative abundance. The α-diversity measurements of prokaryotic communities showed no difference in taxa evenness and richness based on sampling sites (shower or hand basins), sampling phases (months), and presence or absence of Vermamoeba vermiformis. However, β-diversity measurements showed significant clustering of prokaryotic communities based on sampling phases, with the greatest difference observed between the samples collected in phase 1 vs phase 2/3. Importantly, significant difference was observed in prokaryotic communities based on flow dynamics of the incoming water. The Pielou\'s evenness diversity index revealed a significant difference (Kruskal Wallis, p < 0.05) and showed higher species richness in low flow regime (< 13 minutes water flushing per week and ≤ 765 flushing events per six months). Similarly, Bray-Curtis dissimilarity index found significant differences (PERMANOVA, p < 0.05) in the prokaryotic communities of low vs medium/high flow regimes. Furthermore, linear discriminant analysis effect size showed that several biofilm forming (e.g., Pseudomonadales), corrosion causing (e.g., Desulfobacterales), extremely environmental stress resistant (e.g., Deinococcales), and potentially pathogenic (e.g., Pseudomonas) bacterial taxa were in higher amounts under low flow regime conditions. This study demonstrated that a hospital building water system consists of a complex microbiome that is shaped by incoming water quality and the building flow dynamics arising through usage.
摘要：
近年来,医院感染的频率增加了。医院供水系统支持微生物的生长，尤其是机会性前提下的管道病原体。在这项研究中,从医院淋浴和手盆采集的水样中存在浮游原核生物群落，在三个不同的采样阶段收集，通过16SrRNA基因扩增子测序进行表征。通过单变量和多变量分析发现各种原核分类群的丰度存在显着差异。总的来说,医院水的原核生物群落在分类学上是多样化的，并以生物膜形成为主导，腐蚀原因,和潜在的致病细菌。门变形杆菌,放线菌,拟杆菌,Planctomycetota,Firmicutes,蓝细菌占相对丰度的96％。原核生物群落的α多样性测量显示，基于采样点（淋浴或手盆）的分类单元均匀度和丰富度没有差异，采样阶段（月），以及是否存在Vermamoeba。然而,β多样性测量显示，基于采样阶段，原核生物群落具有显著的聚类，在第1阶段与第2/3阶段收集的样品之间观察到最大的差异。重要的是,根据进水的流动动力学，在原核群落中观察到显着差异。Pielou的均匀度多样性指数显示出显著差异(KruskalWallis，p<0.05），并在低流量状态下显示出更高的物种丰富度（每周<13分钟冲洗水，每六个月≤765次冲洗事件）。同样，Bray-Curtis差异指数发现显著差异(PERMANOVA，p<0.05）在低流量与中/高流量的原核群落中。此外，线性判别分析效应大小表明，几种生物膜形成(例如，Pseudomonadales),腐蚀原因(例如，脱硫杆菌)，极其耐环境应力(例如，Deinococcales)，和潜在的致病性(例如，假单胞菌）细菌类群在低流动状态条件下的数量较高。这项研究表明，医院建筑供水系统由复杂的微生物组组成，该微生物组由进入的水质和使用过程中产生的建筑流量动力学形成。
