Liang Xue

Human norovirus (HuNoV) is one of the most important foodborne viruses and poses a significant risk in frozen foods along the cold chain. Traditional disinfectants exhibit reduced efficacy in frozen matrices and often fail to meet the requirements for food applications. This study optimized and evaluated a novel antifreeze–peracetic acid formulation (Af-PAA) for application on frozen foods, achieving disinfection performance at −40 °C. The formulation was optimized using four indicator microorganisms, with effective Af-PAA concentrations of 200 mg/L for Escherichia coli, 200 mg/L for Staphylococcus aureus, 500 mg/L for Candida albicans, and 2000 mg/L for Aspergillus niger. HuNoV GII.4[P31] propagated in zebrafish was inoculated onto frozen food samples. The frozen blueberries (500 mg/L), carrots (500 mg/L), chicken breast (2000 mg/L), and Arctic shrimp (2000 mg/L) were then subjected to Af-PAA treatment at −40 °C for 60 min with 60 s vortex mixing. RNase-RT-qPCR analysis showed a 3.0–3.1 log₁₀ reduction in RNase-resistant HuNoV RNA signals across all tested food under the corresponding treatment concentrations. No visual changes were observed in treated foods. This study demonstrated that Af-PAA met tested food disinfectant requirements and effectively inactivated indicator microorganisms. HuNoV signals were also markedly reduced on the tested foods. These findings support its application for microbial risk control in cold-chain foods.

Human norovirus (HuNoV) is the leading cause of foodborne viral gastroenteritis worldwide, yet its persistence in foods is still commonly interpreted through a simplified framework of contamination and residual survival. Accumulating evidence indicates that HuNoV persistence in food systems may be shaped by dynamic, genotype-dependent interactions with multiple classes of candidate ligands and retention mechanisms associated with hosts, food matrices, and microbiota. This review synthesizes current advances in the molecular basis and ecological consequences of these interactions, with emphasis on canonical and non-canonical glycans, HBGA-like substances, proteinaceous ligands, and bacterial surface or matrix-associated components. Structural, biophysical, and food-model studies collectively suggest that such factors may modulate capsid engagement, tissue retention, bioaccumulation, environmental stability, and, in some experimental systems, infectivity-related outcomes in representative matrices including leafy vegetables, bivalve mollusks, and bacteria-rich food environments. This multi-ligand perspective helps explain the matrix-dependent limitations of conventional washing, depuration, disinfection, and nucleic acid-based detection, as well as the frequent disconnect between measured viral signals and actual transmission risk. By linking molecular recognition to real food scenarios, this review highlights a shift from single-receptor and single-treatment perspectives toward mechanism-informed detection, risk assessment, and intervention strategies. A more integrated understanding of virus-ligand-matrix-microbiota interactions will be essential for improving the prediction and control of HuNoV foodborne transmission.

Background: Human noroviruses are the leading cause of foodborne gastroenteritis worldwide. Accumulating evidence suggests that food matrices containing fucosylated or histo-blood group antigen (HBGA)-like glycans may facilitate viral attachment and persistence, yet the molecular mechanisms underlying these interactions remain unclear. Methods: In this study, we performed a comparative computational analysis of norovirus–glycan interactions by integrating AlphaFold3-based structure prediction, molecular docking, and molecular dynamics simulations. A total of 182 P-domain models representing all genotypes across five human norovirus genogroups (GI, GII, GIV, GVIII, and GIX) were predicted and docked with a lettuce-derived core-fucosylated hexasaccharide (H₂N₂F₂) previously identified by our group. The three complexes exhibiting the most favorable docking energies were further examined using 40 ns molecular dynamics simulations, followed by MM/GBSA binding free energy calculations and per-residue decomposition analyses. Results: Docking results indicated that the majority of modeled P proteins were able to adopt energetically favorable interaction poses with H₂N₂F₂, with predicted binding energies ranging from −3.7 to −7.2 kcal·mol⁻¹. The most favorable docking energies were observed for GII.6_S9c_KC576910 (−7.2 kcal·mol⁻¹), GII.3_MX_U22498 (−7.1 kcal·mol⁻¹), and GII.4_CARGDS11182_OR700741 (−6.8 kcal·mol⁻¹). Molecular dynamics simulations suggested stable ligand engagement within canonical HBGA-binding pockets, with recurrent residues such as Asp374, Gln393, and Arg345 contributing to electrostatic and hydrophobic interactions, consistent with previously reported HBGA-binding motifs. MM/GBSA analyses revealed comparatively favorable binding tendencies among these complexes, particularly for globally prevalent genotypes including GII.3, GII.4, and GII.6. Conclusions: This work provides a large-scale structural and energetic assessment of the potential interactions between a naturally occurring lettuce-derived fucosylated hexasaccharide and human norovirus P domains. The results support the notion that core-fucosylated food-associated glycans can serve as interaction partners for diverse norovirus genotypes and offer comparative molecular insights into glycan recognition patterns relevant to foodborne transmission. The integrative AlphaFold3–docking–dynamics framework presented here may facilitate future investigations of virus–glycan interactions within food matrices.

Foodborne diseases are major public health problems globally. Metagenomics has emerged as a widely used tool for pathogen screening. In this study, we conducted an updated Tn5 transposase-assisted RNA/DNA hybrid co-tagmentation (TRACE) library construction approach. To address the detection of prevalent known foodborne viruses and the discovery of unknown pathogens, we employed both specific primers and oligo-T primers during reverse transcription. The method was validated using clinical samples confirmed by RT-qPCR and compared with standard RNA-seq library construction methods. The mapping-based approach enabled the retrieval of nearly complete genomes (>95%) for the majority of virus genome segments (86 out of 88, 97.73%), with a mean coverage depth of 21,494.53× (ranging from 77.94× to 55,688.58×). Co-infection phenomena involving prevalent genotypes of Norovirus with Astrovirus and Human betaherpesvirus 6B were observed in two samples. The updated TRACE-seq exhibited superior performance in viral reads percentages compared to standard RNA-seq library preparation methods. This updated method has expanded its target pathogens beyond solely Norovirus to include other prevalent foodborne viruses. The feasibility and potential effectiveness of this approach were then evaluated as an alternative method for surveilling foodborne viruses, thus paving the way for further exploration into whole-genome sequencing of viruses.

A significant foodborne pathogen that causes acute gastroenteritis worldwide is sapovirus. Currently, there have been reports of certain recombinant strains of sapovirus, and the genetic diversity of this virus is continuously increasing. In this study, sapovirus nucleotide sequences with entire VP1 and NS6-7 regions were obtained from GenBank, and phylogenetic analysis and genetic distance calculations were performed to investigate the genetic diversity of the VP1 and NS6-7 regions of this virus. In addition to the 19 known genogroups, a small number of sequences were discovered to be beyond the range of known genogroups and were temporarily divided (Bat NA1-Bat NA3). This was based on the genetic diversity of the entire VP1 region. Based on the VP1 region, 38 key reference sequences were also suggested. Furthermore, for 33 sequences for which the genotyping tool mistyped, the genotype and genogroup information were modified. We also attempted to categorize sapovirus based on the genetic diversity of the nucleotide sequences of NS6-7 region. Phylogenetically, 17 P (polymerase)-groups (GI.P-GIII.P, GV.P-GVIII.P, GX.P-GXIX.P) and one tentative (GNA1.P) were identified based on the genetic diversity of nucleotide sequences in the entire NS6-7 region, and 35 related reference sequences were also suggested. Nine recombinant sequences, including six recombinant genotypes (GI.1[P4], GI.2[P1], GII.4[P1], GII.4[PNA1], GII.6[P2], and GV.5[P3]), were identified by genetic diversity differences between VP1 and NS6-7 of sapovirus. With this approach, sapovirus recombination events may be effectively characterized.