National Food Virology Reference Centre, Bureau of Microbial Hazards, Food Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, Ontario, Canada K1A 0K9.
(ORCID: https://orcid.org/0000-0003-0736-0423 [N.N.]).
J Food Prot. 2020 Mar 1;83(3):388-396. doi: 10.4315/0362-028X.JFP-19-345.
Foodborne viruses such as norovirus and hepatitis A virus (HAV) are highly transmissible, persistent in the environment, and resistant to many conventional inactivation methods. Foods can become contaminated with these viruses either at the source of harvest or during food handling and processing. Multiple lines of evidence suggest that foodborne viruses can survive desiccation and dry conditions. Several foodborne virus outbreaks have been linked to low-moisture foods (LMFs), indicating that these foods can be vehicles of virus transmission. However, the efficiencies of common virus extraction methodologies have not been examined with LMFs. We adapted the International Organization for Standardization (ISO) 15216-1:2017 method for virus recovery for use with chocolate, pistachios, and cornflakes. We also developed a magnetic bead assay for the recovery of HAV from LMFs and used the porcine gastric mucin-coated magnetic beads (PGM-MBs) to extract norovirus surrogates, feline calicivirus (FCV), and murine norovirus (MNV) from the same LMFs. The efficiency of virus recovery using the bead-based assay was then compared with that of the ISO 15216-1:2017 method. In chocolate and pistachios, the recovery rates with the PGM-MB method were 5.6- and 21.3-fold higher, respectively, for FCV and 1.65- and 18-fold higher, respectively, for MNV than those with the ISO 15216-1:2017 method. However, the PGM-MB method failed to recover MNV and FCV from cornflakes. The recovery rates for HAV in chocolate, pistachios, and corn flakes with the magnetic bead method were 11.5-, 3-, and 5.6-fold higher, respectively, than those with the ISO 15216-1:2017 method. Thus, depending upon the food matrix and the target virus, the bead-based assays can be used to efficiently and rapidly extract viruses from LMFs.
食源病毒，如诺如病毒和甲型肝炎病毒（HAV）具有高度传染性，在环境中具有持久性，并且能够抵抗许多常规的灭活方法。这些病毒可以在收获源或食品处理和加工过程中污染食品。有多种证据表明食源病毒可以在干燥和干燥条件下存活。有几起食源病毒暴发与低水分食品（LMF）有关，这表明这些食品可能是病毒传播的载体。但是，尚未用 LMF 检查常见病毒提取方法的效率。我们根据国际标准化组织（ISO）15216-1：2017 病毒回收方法，对巧克力、开心果和玉米片进行了修改。我们还开发了一种用于从 LMF 中回收 HAV 的磁珠测定法，并使用猪胃粘膜包被的磁珠（PGM-MB）从相同的 LMF 中提取诺如病毒替代物、猫杯状病毒（FCV）和鼠诺如病毒（MNV）。然后将基于珠的测定法的病毒回收率与 ISO 15216-1：2017 方法进行了比较。在巧克力和开心果中，使用 PGM-MB 方法的 FCV 和 MNV 的回收率分别比 ISO 15216-1：2017 方法高 5.6 倍和 21.3 倍，而 MNV 和 FCV 的回收率分别高 1.65 倍和 18 倍。但是，PGM-MB 方法未能从玉米片中回收 MNV 和 FCV。用磁珠法从巧克力、开心果和玉米片中回收 HAV 的回收率分别比 ISO 15216-1：2017 方法高 11.5 倍、3 倍和 5.6 倍。因此，根据食品基质和目标病毒，基于珠的测定法可用于有效地从 LMF 中快速提取病毒。
