Analysis of Synchronous and Asynchronous In Vitro Infections with Homologous Murine Norovirus Strains Reveals Time-Dependent Viral Interference Effects

Abstract

Viral recombination is a key mechanism in the evolution and diversity of noroviruses. In vivo, synchronous single-cell coinfection by multiple viruses, the ultimate prerequisite to viral recombination, is likely to be a rare event and delayed secondary infections are a more probable occurrence. Here, we determine the effect of a temporal separation of in vitro infections with the two homologous murine norovirus strains MNV-1 WU20 and CW1 on the composition of nascent viral populations. WU20 and CW1 were either synchronously inoculated onto murine macrophage cell monolayers (coinfection) or asynchronously applied (superinfection with varying titres of CW1 at half-hour to 24-h delays). Then, 24 h after initial co-or superinfection, quantification of genomic copy numbers and discriminative screening of plaque picked infectious progeny viruses demonstrated a time-dependent predominance of primary infecting WU20 in the majority of viral progenies. Our results indicate that a time interval from one to two hours onwards between two consecutive norovirus infections allows for the establishment of a barrier that reduces or prevents superinfection.

Charge Detection Mass Spectrometry Reveals Favored Structures in the Assembly of Virus-Like Particles: Polymorphism in Norovirus GI.1

“…It is the leading cause of foodborne illness in the United States, and responsible for the loss of over $60 billion annually from healthcare expenses and lost productivity worldwide. 1,2 The virus has significant genetic diversity with 10 genogroups and 49 genotypes identified. 1 Genogroups I, II, IV, VIII and IX (GI, GII, GIV, GIV, and GIX) infect humans, though most infections involve GI and GII.…”

“…1,2 The virus has significant genetic diversity with 10 genogroups and 49 genotypes identified. 1 Genogroups I, II, IV, VIII and IX (GI, GII, GIV, GIV, and GIX) infect humans, though most infections involve GI and GII. 3 There is no vaccine, and due to its genetic diversity and the propensity of norovirus to quickly evolve, a more traditional, cost-effective approach is preferred to the next-generation vaccines used to combat COVID-19.…”