Seasonal occurrence and abundance of norovirus in pre- and postharvest lettuce samples in Nanjing, China

Advancements in magnetic nanomaterial-assisted sensitive detection of foodborne bacteria: Dual-recognition strategies, functionalities, and multiplexing applications

Foodborne bacterial diseases are a major cause of human death. Sensitively quantifying those bacteria in foodstuffs is crucial for effective prevention. Yet, the matrix effect from abundant food interferents challenges this goal. Magnetic nanomaterials have been extensively utilized as effective sample pretreatment agents to facilitate the sensitive detection of bacterial pathogens, benefiting from their contribution to mitigating interference in food matrices. The advancement of magnetic scaffold-based biosensors in monitoring foodborne bacteria is reviewed in this work. This review highlights the dual-recognition strategies, which contribute to superior affordability and applicability in bacteria monitoring. The functionalities of magnetic nanoscaffolds in constructing pathogen-targeted biosensors are cataloged into three sections: magnetic separation mediators, signal generation probes, and agents for inactivating bacterial pathogens. Additionally, magnetic nanocomposite-driven multiplexing determination is critically discussed, with different detection approaches are highlighted. Further perspectives regarding superior multifunctional magnetic probes, tunable selection of bioreceptor, portable detection devices, smart identification, and differentiation of bacteria mixtures are introduced.

Recent Advances in Food Safety: Nanostructure-Sensitized Surface-Enhanced Raman Sensing

Food safety is directly related to human health and has attracted intense attention all over the world. Surface-enhanced Raman scattering (SERS), as a rapid and selective technique, has been widely applied in monitoring food safety. SERS substrates, as an essential factor for sensing design, greatly influence the analytical performance. Currently, nanostructure-based SERS substrates have garnered significant interest due to their excellent merits in improving the sensitivity, specificity, and stability, holding great potential for the rapid and accurate sensing of food contaminants in complex matrices. This review summarizes the fundamentals of Raman spectroscopy and the used nanostructures for designing the SERS platform, including precious metal nanoparticles, metal-organic frameworks, polymers, and semiconductors. Moreover, it introduces the mechanisms and applications of nanostructures for enhancing SERS signals for monitoring hazardous substances, such as foodborne bacteria, pesticide and veterinary drug residues, food additives, illegal adulterants, and packaging material contamination. Finally, with the continuous progress of nanostructure technology and the continuous improvement of SERS technology, its application prospect in food safety testing will be broader.

A systematic review and meta-analysis indicates a high risk of human noroviruses contamination in vegetable worldwide, with GI being the predominant genogroup

Human noroviruses (HuNoVs) are the most predominant viral agents of acute gastroenteritis. Vegetables are important vehicles of HuNoVs transmission. This study aimed to assess the HuNoVs prevalence in vegetables. We searched the Web of Science, Excerpta Medica Database, PubMed, and Cochrane databases until June 1, 2023. A total of 27 studies were included for the meta-analysis. Statistical analysis was conducted using Stata 14.0 software. This analysis showed that the pooled HuNoVs prevalence in vegetables was 7 % (95 % confidence interval (CI): 3-13) worldwide. The continent with largest number of studies was Europe, and the highest number of samples was lettuce. As revealed by the results of the subgroup meta-analysis, the prevalence of GI genogroup was the highest (3 %, 95 % CI: 1-7). A higher prevalence was seen in vegetables from farms (18 %, 95 % CI: 5-37), while only 4 % (95 % CI: 1-8) in retail. The HuNoVs prevalence of ready-to-eat vegetables and non-ready-to-eat vegetables was 2 % (95 % CI: 0-8) and 9 % (95 % CI: 3-16), respectively. The prevalence by quantitative real time RT-PCR was 8 % (95 % CI: 3-15) compared to 3 % (95 % CI: 0-13) by conventional RT-PCR. Furthermore, the HuNoVs prevalence in vegetables was 6 % (95 % CI: 1-14) in ISO pretreatment method and 8 % (95 % CI: 1-19) in non-ISO method, respectively. This study is helpful in comprehensively understanding the prevalence of HuNoVs contamination in vegetables worldwide.