Zilei Zhang

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.

The prevalence of norovirus in oysters poses a significant threat to food safety, necessitating a comprehensive understanding of contamination patterns. This study explores the temporal dynamics of norovirus distribution in various oyster tissues over a contamination period ranging from 6 to 96 h. Four tissues—the gill, palp, digestive gland, and stomach—were subjected to systematic monitoring using RT-qPCR for absolute quantification. Results revealed rapid norovirus detection in all tissues six hours post-contamination, with subsequent variations in detection rates. Gill and digestive gland tissues exhibited a peak in detection at 12–24 h, aligning with the oyster’s gastrointestinal circulatory system. The digestive gland, distinguished by specific enrichment and adsorption capabilities, demonstrated the highest virus concentration at 48 h. In contrast, the stomach displayed a reemergence of norovirus. Beyond 72 h, detection remained exclusive to the digestive gland, with Ct values comparable to earlier time points. At 96 h, a limited amount of norovirus was detected in the digestive gland, emphasizing the importance for timely monitoring. In addition to providing critical insights into optimal detection strategies, these findings highlight the time-related characteristics of norovirus contamination in oysters. The study identifies the digestive gland as a key target for reliable monitoring, providing valuable data to improve protocols for reducing hazards associated with oyster consumption and foodborne norovirus infections. This research contributes to the understanding of norovirus dynamics in oyster tissues and reinforces current efforts aimed at ensuring food safety and public health.

Zika virus (ZIKV), an emerging arthropod-borne flavivirus, was first isolated in Uganda in 1947 from monkeys and first detected in humans in Nigeria in 1952; it has been associated with a dramatic burden worldwide. Since then, interventions to reduce the burden of ZIKV infection have been mainly restricted to mosquito control, which in the end proved to be insufficient by itself. Hence, the situation prompted scientists to increase research on antivirals and vaccines against the virus. These efforts are still ongoing as the pathogenesis and immune evasion mechanisms of ZIKV have not yet been fully elucidated. Understanding the viral disease mechanism will provide a better landscape to develop prophylactic and therapeutic strategies against ZIKV. Currently, no specific vaccines or drugs have been approved for ZIKV. However, some are undergoing clinical trials. Notably, different platforms have been evaluated for the design of vaccines, including DNA, mRNA, viral vectors, virus-like particles (VLPs), inactivated virus, live attenuated virus, peptide and protein-based vaccines, passive immunizations by using monoclonal antibodies (MAbs), and vaccines that target vector-derived antigens. These vaccines have been shown to induce specific humoral and cellular immune responses and reduce viremia and viral RNA titers, both in vitro and in vivo. This review provides a comprehensive summary of current advancements in the development of vaccines against Zika virus.