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.