Studying interactions between noroviruses and their environment to reduce foodborne transmission

人类诺如病毒（hNoV）是全世界急性胃肠炎的主要病因。在加拿大，它导致65%的食源性疾病，每年超过100万例。它对各种环境条件和许多常规消毒剂的抵抗力有助于其传播。食源性病毒最近已成为几项研究的主题，以解释它们在环境中的高影响和抗性。尽管如此，这些研究的一个重要部分是用纯病毒培养物进行的，没有考虑它们与微生物群落的相互作用。然而，在感染之前和感染期间，食源性病毒与共生细菌共存。虽然已经研究了人类肠道微生物群中细菌对肠道病毒传染性的影响，但关于病毒-细菌相互作用的重要性仍然存在一些空白。病毒与食物菌群之间的相互作用及其在食物基质中hNoV持续存在中的作用也是如此。在这个为期五年的研究项目中，将采用基于分子生物学、生物物理学、消化生理学、界面化学和食品科学的多学科方法来研究病毒与细菌的相互作用，以及这些相互作用如何影响病毒的持久性和对消毒剂的耐药性。我们特别寻求(i)利用斑马鱼幼虫系统收集在加拿大传播的hNoV；（ii）研究hNoV在不同食物基质中的体外行为和胃肠道耐药性；（iii）确定hNoV与不同环境中其他微生物之间的相互作用，以及（iv）评估这些相互作用对病毒灭活策略有效性的影响以及对食源性病毒的一般影响。提出的研究计划完全是原创的，是我们以前工作的合理延续。它处理食品部门的甲型h1n1流感问题，这是防治食源性疾病的国家和国际优先事项。该计划的结果将产生有关hNoV在食物环境中的行为以及解释其持久性和抗性的因素的宝贵数据。了解这些与传播有关的现象，对于制定最佳战略以减少食物链各环节甲型h1n1流感的发病率，从而打破从食品环境到消费者的传播循环至关重要。除了在食品部门制定更有效的灭活策略外，我们的研究结果还可用于制定指南，以限制hNoV的传播，加强食品安全，从而使消费者放心。从长远来看，我们的结果将产生重大的社会经济影响，因为实施最有效的方法来减少病毒性食源性疾病的发病率，只能减轻医疗保健系统的负担，减少缺勤和加拿大和世界范围内因召回受污染产品而造成的损失。

Human norovirus (hNoV) is the leading cause of acute gastroenteritis worldwide. In Canada, it causes 65% of foodborne illnesses, more than one million cases each year. Its resistance to a wide range of environmental conditions and to many conventional disinfectants contributes to its transmissibility. Foodborne viruses have recently been the subject of several studies to explain their high impact and resistance in the environment. Nonetheless, an important part of these studies was carried out with pure viral cultures without considering their interactions with the microbial community. However, foodborne viruses coexist with commensal bacteria prior to and during infection. Although the effect of bacteria in the human gut microbiota on the infectiousness of enteric viruses has been examined, several gaps remain regarding the importance of virus-bacteria interactions. The same is true for interactions between viruses and food microflora and their role in the persistence of hNoV in food matrices. In this five-year research program, a multidisciplinary approach based on molecular biology, biophysics, digestive physiology, interface chemistry and food science will be applied to study interactions virus-bacteria and how these influence viral persistence and resistance to sanitizers. We especially seek to (i) develop a collection of hNoV circulating in Canadia using a zebrafish larvae system; (ii) study in vitro the behavior and gastrointestinal resistance of hNoV in various food matrices; (iii) identify interactions between hNoV and other microorganisms in different environments, and (iv) evaluate the impact of these interactions on the effectiveness of viral inactivation strategies and implications for foodborne viruses in general. The proposed research program is entirely original and is a logical continuation of our previous works. It addresses the problem of hNoV in the food sector, a national and international priority in the fight against foodborne diseases. The results of this program will generate valuable data on the behavior of hNoV in the food environment and the factors that explain its persistence and resistance. Understanding these phenomena related to the transmission is essential to establishing the best strategies to reduce the incidence of hNoV at all points in the food chain and thus break the cycle of transmission from the food environment to consumers. In addition to the development of more effective inactivation strategies in the food sector, our results could also be used in the development of guidelines to limit the transmission of hNoV, reinforce food safety and thereby reassure consumers. On the longer term, our results will have a significant socio-economic impact since implementing the most effective means of reducing the incidence of viral foodborne illness can only lessen the burden on the healthcare system and reduce absenteeism and losses due to recalls of contaminated products in Canada and worldwide.