Department of Food Science, Center for Food Safety, University of Arkansas System Division of Agriculture, 1371 West Altheimer Dr, Fayetteville, AR, 72704, USA.
Food Microbiology and Food Preservation Research Unit, Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, 9000, Ghent, Belgium.
Food Environ Virol. 2024 Dec;16(4):492-505. doi: 10.1007/s12560-024-09613-3. Epub 2024 Sep 11.
Human norovirus (HuNoV) is the leading cause of foodborne illness in the developed world and a major contributor to gastroenteritis globally. Its low infectious dose and environmental persistence necessitate effective disinfection protocols. Sodium hypochlorite (NaOCl) bleach is a widely used disinfectant for controlling HuNoV transmission via contaminated fomites. This study aimed to evaluate the susceptibility of HuNoV genotypes (n = 11) from genogroups I, II, and IV to NaOCl in suspension. HuNoV was incubated for 1 and 5 min in diethyl pyrocarbonate (DEPC) treated water containing 50 ppm, 100 ppm, or 150 ppm NaOCl, buffered to maintain a pH between 7.0 and 7.5. Neutralization was achieved by a tenfold dilution into 100% fetal bovine serum. RNase pre-treatment followed by RT-qPCR was used to distinguish between infectious and non-infectious HuNoV. Statistical methods, including imputation, machine learning, and generalized linear models, were applied to process and analyze the data. Results showed that NaOCl reduced viral loads across all genotypes, though efficacy varied. Genotypes GI.1, GII.4 New Orleans, and GII.4 Sydney were the least susceptible, while GII.6 and GII.13 were the most susceptible. All NaOCl concentrations above 0 ppm were statistically indistinguishable, and exposure duration did not significantly affect HuNoV reduction, suggesting rapid inactivation at effective concentrations. For instance, some genotypes were completely inactivated within 1 min, rendering extended exposure unnecessary, while other genotypes maintained the initial concentration at both 1 and 5 min, indicating a need for longer contact times. These findings underscore the critical role of HuNoV genotype selection in testing disinfection protocols and optimizing NaOCl concentrations. Understanding HuNoV susceptibility to NaOCl bleach informs better disinfection strategies, aiding public health and food safety authorities in reducing HuNoV transmission and outbreaks.
人类诺如病毒（HuNoV）是发达国家食源性疾病的主要致病原，也是全球范围内胃肠炎的主要致病原。其感染剂量低且在环境中具有持久性，因此需要有效的消毒方案。次氯酸钠（NaOCl）漂白剂是一种广泛用于控制通过污染媒介物传播的 HuNoV 的消毒剂。本研究旨在评估基因型为 I、II 和 IV 的 HuNoV （n = 11）在悬浮液中对 NaOCl 的敏感性。HuNoV 在经二乙基焦碳酸酯（DEPC）处理的水中孵育 1 分钟和 5 分钟，水中含有 50 ppm、100 ppm 或 150 ppm 的 NaOCl，并缓冲至 pH 值在 7.0 到 7.5 之间。通过十倍稀释至 100%胎牛血清来实现中和。用 RNase 预处理后进行 RT-qPCR 以区分有感染性和无感染性的 HuNoV。应用统计方法，包括插补、机器学习和广义线性模型，来处理和分析数据。结果表明，NaOCl 降低了所有基因型的病毒载量，但效果有所不同。GI.1、GII.4 新奥尔良和 GII.4 悉尼基因型对 NaOCl 的抵抗力最低，而 GII.6 和 GII.13 对 NaOCl 的抵抗力最强。所有浓度高于 0 ppm 的 NaOCl 均无统计学差异，暴露时间也不会显著影响 HuNoV 的减少，表明在有效浓度下迅速失活。例如，一些基因型在 1 分钟内完全失活，因此不需要延长暴露时间，而其他基因型在 1 分钟和 5 分钟时都保持初始浓度，这表明需要更长的接触时间。这些发现强调了 HuNoV 基因型选择在测试消毒方案和优化 NaOCl 浓度方面的关键作用。了解 HuNoV 对 NaOCl 漂白剂的敏感性为制定更好的消毒策略提供了信息，有助于公共卫生和食品安全当局减少 HuNoV 的传播和暴发。
