Peroxide Disinfection of Vesicle-Cloaked Murine Norovirus Clusters: Vesicle Membranes Protect Viruses from Inactivation

Vesicle-cloaked virus clusters, also known as viral vesicles, exhibit higher infectivity than free viruses and demonstrate persistence in the environment as well as resilience against disinfection. These emerging pathogens represent significant, yet often underestimated, health risks. Our study investigated peroxide disinfection of murine norovirus vesicles, a surrogate for human norovirus vesicles, and elucidated disinfection mechanisms. Peracetic acid, a neutral peroxide, rapidly inactivated murine norovirus vesicles. In contrast, negatively charged peroxides, i.e., peracetate and peroxymonosulfate, exhibited restricted effectiveness in inactivating murine noroviruses within vesicles. The largely intact viruses cloaked within vesicles remained infectious and retained their ability to replicate upon vesicle lysis triggered by mechanical forces, enzymatic activity, or chemical reactions following disinfection. Peroxides primarily targeted vesicle/viral proteins, particularly amino acid residues such as cysteine and methionine, without affecting the viral ORF2 gene fragment or vesicle structures. Disruption of viral internalization, rather than binding, plays a key role in infectivity loss. This work highlights the protective role of vesicle membranes and emphasizes the need for innovative disinfection approaches to effectively target viruses cloaked within vesicles.

囊泡包裹的病毒簇（vesicle-cloaked virus clusters），又称病毒囊泡（viral vesicles），其感染性高于游离病毒，且可在环境中长期存续、耐受消毒处理。这类新兴病原体构成了显著却常被低估的健康风险。本研究以鼠诺如病毒囊泡作为人诺如病毒囊泡的替代模型，探究了其过氧化物消毒效果并阐明了消毒机制。中性过氧化物过氧乙酸可快速灭活鼠诺如病毒囊泡；与之相反，带负电的过氧化物（即过乙酸盐与过一硫酸盐）对囊泡内鼠诺如病毒的灭活效果有限。经消毒处理后，当机械力、酶活性或化学反应触发囊泡破裂时，包裹于囊泡内的完整病毒仍可恢复感染性并具备复制能力。过氧化物主要靶向囊泡/病毒蛋白，尤其是半胱氨酸（cysteine）与甲硫氨酸（methionine）等氨基酸残基，并不会影响病毒开放阅读框2（ORF2, Open Reading Frame 2）基因片段或囊泡结构。病毒内化过程受阻而非病毒结合过程被阻断，是其感染性丧失的核心原因。本研究凸显了囊泡膜的保护作用，并强调亟需开发创新型消毒策略，以有效靶向并灭活囊泡内包裹的病毒。