Department of Environmental Health, Water and Health Unit, National Institute for Health and Welfare, P.O. Box 95, FI-70701 Kuopio, Finland.
J Water Health. 2012 Sep;10(3):406-18. doi: 10.2166/wh.2012.003.
A contaminated drinking water distribution network can be responsible for major outbreaks of infections. In this study, two chemical decontaminants, peracetic acid (PAA) and chlorine, were used to test how a laboratory-scale pipeline system can be cleaned after simultaneous contamination with human adenovirus 40 (AdV40) and Escherichia coli. In addition, the effect of the decontaminants on biofilms was followed as heterotrophic plate counts (HPC) and total cell counts (TCC). Real-time quantitative polymerase chain reaction (qPCR) was used to determine AdV40 and plate counting was used to enumerate E. coli. PAA and chlorine proved to be effective decontaminants since they decreased the levels of AdV40 and E. coli to below method detection limits in both water and biofilms. However, without decontamination, AdV40 remained present in the pipelines for up to 4 days. In contrast, the concentration of cultivable E. coli decreased rapidly in the control pipelines, implying that E. coli may be an inadequate indicator for the presence of viral pathogens. Biofilms responded to the decontaminants by decreased HPCs while TCC remained stable. This indicates that the mechanism of pipeline decontamination by chlorine and PAA is inactivation rather than physical removal of microbes.
受污染的饮用水分配网络可能是导致大规模感染爆发的原因。在这项研究中，使用了两种化学消毒剂，过氧乙酸（PAA）和氯，来测试实验室规模的管道系统在同时受到人类腺病毒 40（AdV40）和大肠杆菌污染后如何进行清洁。此外，还跟踪了消毒剂对异养平板计数（HPC）和总细胞计数（TCC）的生物膜的影响。实时定量聚合酶链反应（qPCR）用于检测 AdV40，平板计数用于计数 E. coli。PAA 和氯被证明是有效的消毒剂，因为它们将 AdV40 和 E. coli 的水平降低到低于方法检测限，无论是在水中还是在生物膜中。然而，如果不进行消毒，AdV40 在管道中最多可存在 4 天。相比之下，可培养的 E. coli 在对照管道中的浓度迅速下降，这意味着 E. coli 可能不是病毒病原体存在的合适指标。生物膜对消毒剂的反应是 HPC 减少，而 TCC 保持稳定。这表明氯和 PAA 对管道进行消毒的机制是灭活而不是微生物的物理去除。
