PDF(Pubmed)
Abstract：
Biofilms within drinking water distribution systems serve as a habitat for drinking water microorganisms. However, biofilms can negatively impact drinking water quality by causing water discoloration and deterioration and can be a reservoir for unwanted microorganisms. In this study, we investigated whether indicator organisms for drinking water quality, such as coliforms, can settle in mature drinking water biofilms. Therefore, a biofilm monitor consisting of glass rings was used to grow and sample drinking water biofilms. Two mature drinking water biofilms were characterized by flow cytometry, ATP measurements, confocal laser scanning microscopy, and 16S rRNA sequencing. Biofilms developed under treated chlorinated surface water supply exhibited lower cell densities in comparison with biofilms resulting from treated groundwater. Overall, the phenotypic as well as the genotypic characteristics were significantly different between both biofilms. In addition, the response of the biofilm microbiome and possible biofilm detachment after minor water quality changes were investigated. Limited changes in pH and free chlorine addition, to simulate operational changes that are relevant for practice, were evaluated. It was shown that both biofilms remained resilient. Finally, mature biofilms were prone to invasion of the coliform, Serratia fonticola. After spiking low concentrations (i.e., ±100 cells/100 mL) of the coliform to the corresponding bulk water samples, the coliforms were able to attach and get established within the mature biofilms. These outcomes emphasize the need for continued research on biofilm detachment and its implications for water contamination in distribution networks.
OBJECTIVE: The revelation that even low concentrations of coliforms can infiltrate into mature drinking water biofilms highlights a potential public health concern. Nowadays, the measurement of coliform bacteria is used as an indicator for fecal contamination and to control the effectiveness of disinfection processes and the cleanliness and integrity of distribution systems. In Flanders (Belgium), 533 out of 18,840 measurements exceeded the established norm for the coliform indicator parameter in 2021; however, the source of microbial contamination is mostly unknown. Here, we showed that mature biofilms, are susceptible to invasion of Serratia fonticola. These findings emphasize the importance of understanding and managing biofilms in drinking water distribution systems, not only for their potential to influence water quality, but also for their role in harboring and potentially disseminating pathogens. Further research into biofilm detachment, long-term responses to operational changes, and pathogen persistence within biofilms is crucial to inform strategies for safeguarding drinking water quality.
OBJECTIVE: The revelation that even low concentrations of coliforms can infiltrate into mature drinking water biofilms highlights a potential public health concern. Nowadays, the measurement of coliform bacteria is used as an indicator for fecal contamination and to control the effectiveness of disinfection processes and the cleanliness and integrity of distribution systems. In Flanders (Belgium), 533 out of 18,840 measurements exceeded the established norm for the coliform indicator parameter in 2021; however, the source of microbial contamination is mostly unknown. Here, we showed that mature biofilms, are susceptible to invasion of Serratia fonticola. These findings emphasize the importance of understanding and managing biofilms in drinking water distribution systems, not only for their potential to influence water quality, but also for their role in harboring and potentially disseminating pathogens. Further research into biofilm detachment, long-term responses to operational changes, and pathogen persistence within biofilms is crucial to inform strategies for safeguarding drinking water quality.
摘要：
饮用水分配系统内的生物膜充当饮用水微生物的栖息地。然而,生物膜可以通过引起水变色和变质而对饮用水质量产生负面影响，并且可以是不需要的微生物的水库。在这项研究中,我们调查了饮用水水质的指示生物，如大肠杆菌，可以在成熟的饮用水生物膜中沉淀。因此,由玻璃环组成的生物膜监测器用于生长和采样饮用水生物膜。通过流式细胞术对两种成熟的饮用水生物膜进行了表征，ATP测量，共聚焦激光扫描显微镜，和16SrRNA测序。与处理过的地下水产生的生物膜相比，在处理过的氯化地表水下形成的生物膜显示出较低的细胞密度。总的来说,两种生物膜之间的表型和基因型特征显着不同。此外,研究了微小水质变化后生物膜微生物组的响应和可能的生物膜脱离。pH值和游离氯添加量的变化有限，模拟与实践相关的操作变化，进行了评估。结果表明，两种生物膜都保持弹性。最后,成熟的生物膜容易入侵大肠杆菌，松香沙雷菌.加标低浓度后(即，±100细胞/100毫升）的大肠杆菌到相应的大量水样中，大肠杆菌能够附着并建立在成熟的生物膜中。这些结果强调了需要继续研究生物膜分离及其对分配网络中水污染的影响。
目的：即使低浓度的大肠杆菌也能渗透到成熟的饮用水生物膜中，这一发现凸显了潜在的公共卫生问题。如今,大肠杆菌的测量被用作粪便污染的指标，并控制消毒过程的有效性以及分配系统的清洁度和完整性。在佛兰德斯（比利时），在2021年的18,840个测量中，有533个超过了大肠杆菌指标参数的既定标准；但是，微生物污染的来源大部分是未知的。这里,我们证明了成熟的生物膜，容易受到沙雷氏菌的侵袭。这些发现强调了在饮用水分配系统中理解和管理生物膜的重要性，不仅因为它们可能影响水质，而且还因为它们在窝藏和潜在传播病原体中的作用。进一步研究生物膜的分离，对业务变化的长期反应，和生物膜中的病原体持久性对于保护饮用水质量的策略至关重要。
目的：即使低浓度的大肠杆菌也能渗透到成熟的饮用水生物膜中，这一发现凸显了潜在的公共卫生问题。如今,大肠杆菌的测量被用作粪便污染的指标，并控制消毒过程的有效性以及分配系统的清洁度和完整性。在佛兰德斯（比利时），在2021年的18,840个测量中，有533个超过了大肠杆菌指标参数的既定标准；但是，微生物污染的来源大部分是未知的。这里,我们证明了成熟的生物膜，容易受到沙雷氏菌的侵袭。这些发现强调了在饮用水分配系统中理解和管理生物膜的重要性，不仅因为它们可能影响水质，而且还因为它们在窝藏和潜在传播病原体中的作用。进一步研究生物膜的分离，对业务变化的长期反应，和生物膜中的病原体持久性对于保护饮用水质量的策略至关重要。
