Evaluating the efficacy of disinfection processes to inactivate human enteric viruses is important for the prevention and control of waterborne diseases caused by exposure to those viruses via drinking water. Here, we evaluated the inactivation of two representative human enteric viruses (adenovirus type 40 [AdV] and coxsackievirus B5 [CV]) by thermal or free-chlorine disinfection. In addition, we compared the infectivity reduction ratio of a plant virus (pepper mild mottle virus [PMMoV], a recently proposed novel surrogate for human enteric viruses for the assessment of virus removal by coagulation‒rapid sand filtration and membrane filtration) with that of the two human enteric viruses to assess the suitability of PMMoV as a human enteric virus surrogate for use in thermal and free-chlorine disinfection processes. Finally, we examined whether conventional or enhanced viability polymerase chain reaction (PCR) analysis using propidium monoazide (PMA) or improved PMA (PMAxx) with or without an enhancer could be used as alternatives to infectivity assays (i.e., plaque-forming unit method for AdV and CV; local lesion count assay for PMMoV) for evaluating virus inactivation by disinfection processes. We found that PMMoV was more resistant to heat treatment than AdV and CV, suggesting that PMMoV is a potential surrogate for these two enteric viruses with regard to thermal disinfection processes. However, PMMoV was much more resistant to chlorine treatment compared with AdV and CV (which is chlorine-resistant) (CT value for 4-log₁₀ inactivation: PMMoV, 84.5 mg-Cl₂∙min/L; CV, 1.15–1.19 mg-Cl₂∙min/L), suggesting that PMMoV is not useful as a surrogate for these enteric viruses with regard to free-chlorine disinfection processes. For thermal disinfection, the magnitude of the signal reduction observed with PMAxx-Enhancer-PCR was comparable with the magnitude of reduction in infectivity, indicating that PMAxx-Enhancer-PCR is a potential alternative to infectivity assay. However, for free-chlorine disinfection, the magnitude of the signal reduction observed with PMAxx-Enhancer-PCR was smaller than the magnitude of the reduction in infectivity, indicating that PMAxx-Enhancer-PCR underestimated the efficacy of virus inactivation (i.e., overestimated the infectious virus concentration) by chlorine treatment. Nevertheless, among the PCR approaches examined in the present study (PCR alone, PMA-PCR or PMAxx-PCR either with or without enhancer), PMAxx-Enhancer-PCR provided the most accurate assessment of the efficacy of virus inactivation by thermal or free chlorine disinfection processes.

评估消毒过程灭活人类肠道病毒的功效对于预防和控制由饮用水接触这些病毒引起的水传播疾病很重要。在这里，我们通过热或游离氯消毒评估了两种代表性的人类肠道病毒（40型腺病毒[AdV]和柯萨奇病毒B5 [CV]）的灭活作用。此外，我们还比较了植物病毒（辣椒轻度斑驳病毒[PMMoV]，一种最近提出的新型人类肠道病毒替代品，用于评估凝结‒快速砂滤和膜滤除病毒）的传染性降低率。两种人类肠道病毒，以评估PMMoV作为人类肠道病毒替代品在热和游离氯消毒过程中的适用性。最后，我们检查了使用传统的或增强的生存力聚合酶链反应（PCR）分析（使用单叠氮化丙锭（PMA）或改进的PMA（PMAxx））（带有或不带有增强剂）是否可以用作传染性测定的替代方法（即AdV和CV；用于PMMoV的局部病变计数测定），用于通过消毒过程评估病毒的灭活作用。我们发现PMMoV比AdV和CV更耐热处理，这表明就热消毒过程而言，PMMoV是这两种肠病毒的潜在替代物。但是，与AdV和CV（具有耐氯性）相比，PMMoV具有更强的耐氯处理性（4 log的CT值）。我们发现PMMoV比AdV和CV更耐热处理，这表明就热消毒过程而言，PMMoV是这两种肠病毒的潜在替代物。但是，与AdV和CV（具有耐氯性）相比，PMMoV具有更强的耐氯处理性（4 log的CT值）。我们发现PMMoV比AdV和CV更耐热处理，这表明就热消毒过程而言，PMMoV是这两种肠病毒的潜在替代物。但是，与AdV和CV（具有耐氯性）相比，PMMoV具有更强的耐氯处理性（4 log的CT值）。₁₀失活：PMMoV，84.5 mg-Cl ₂ ∙min / L; CV，1.15-1.19 mg-Cl ₂∙min / L），这表明PMMoV不能作为游离氯消毒过程中这些肠道病毒的替代品。对于热消毒，用PMAxx-Enhancer-PCR观察到的信号减少幅度可与感染性降低的幅度相媲美，这表明PMAxx-Enhancer-PCR是感染性测定的一种潜在替代方法。但是，对于游离氯消毒，使用PMAxx-Enhancer-PCR观察到的信号减少幅度小于感染性降低的幅度，这表明PMAxx-Enhancer-PCR低估了病毒灭活的功效（即，高估了病毒灭活的效力）。传染性病毒浓度）通过氯处理。不过，在本研究中所研究的PCR方法中（单独进行PCR，具有或不具有增强子的PMA-PCR或PMAxx-PCR），