摘要

       本研究旨在探讨生活热水系统（DHWS）中聚丙烯随机（PPR）、聚氯乙烯和不锈钢管道生物膜形成过程中微生物群落和抗生素抗性基因（ARGs）的动态及其相互作用。全尺度分类用于以0.1%和1%为阈值划分丰富属和稀有属。生物膜群落结构呈现出时间模式，主要由条件稀有或丰富类群（CRAT）和条件稀有类群（CRT）决定。观察了生物膜形成过程中微生物群落的动态变化，管道材料对条件丰富类群（CAT）和CRAT的影响大于CRT和稀有类群（RT）。 CRAT 显示出最复杂的内部关联，并被确定为核心分类群。值得注意的是，相对丰度较低的 CRT 和 RT 在网络中也发挥了重要作用。对于潜在病原体，本研究鉴定了 17 个属，它们的总相对丰度在 PPR 样品中最高（3.6-28.9%）。 CRAT 的肠球菌是年轻生物膜中的主要潜在病原体。在潜在病原体和非致病细菌之间观察到的共排斥模式 (140) 比共发生 (104) 多 36 种。总共预测了 38 个 ARG，在它们之间检测到 109 个负相关和 165 个正相关。一些潜在的病原体（埃希氏菌/志贺氏菌和伯克霍尔德氏菌）和非致病细菌（Meiothermus 和鞘氨醇）被确定为 ARG 的可能宿主。本研究有助于全面了解生物膜微生物群落和ARGs，为新建DHWS的管理和生物安全保障提供参考。

       This study aimed to explore the dynamics of microbial communities and antibiotic resistance genes (ARGs) during biofilm formation on polypropylene random (PPR), polyvinyl chloride and stainless steel pipes in domestic hot water system (DHWS), as well as their interactions. Full-scale classification was used to divide abundant and rare genera with 0.1% and 1% as the thresholds. The biofilm community structure presented a temporal pattern, which was mainly determined by conditionally rare or abundant taxa (CRAT) and conditionally rare taxa (CRT). The dynamics of microbial community during biofilm formation were observed, and the effect of pipe material on conditionally abundant taxa (CAT) and CRAT was greater than CRT and rare taxa (RT). CRAT showed the most complex internal associations and were identified as the core taxa. Notably, CRT and RT with low relative abundance, also played an important role in the network. For potential pathogens, 17 genera were identified in this study, and their total relative abundance was the highest (3.6–28.9%) in PPR samples. Enterococcus of CRAT was the dominant potential pathogen in young biofilms. There were 36 more co-exclusion patterns (140) observed between potential pathogens and nonpathogenic bacteria than co-occurrence (104). A total of 38 ARGs were predicted, and 109 negative and 165 positive correlations were detected between them. Some potential pathogens (Escherichia/Shigella and Burkholderia) and nonpathogenic bacteria (Meiothermus and Sphingopyxis) were identified as the possible hosts of ARGs. This study is helpful for a comprehensive understanding of the biofilm microbial community and ARGs, and provides a reference for the management and biosafety guarantee of newly-built DHWS.

https://www.sciencedirect.com/science/article/abs/pii/S0048969720378955