冷冻食品包装材料表面病毒采样方法的有效性评价研究

Effectiveness evaluation of virus sampling method on the surface of different packaging materials for frozen food

目的优化冷冻食品包装材料表面污染的病毒采样方法,并通过模拟冷冻食品包装材料表面被病毒污染的不同场景,对不同材质的包装材料表面污染的病毒回收率进行研究。方法在不同场景下,将实验用模式病毒均匀涂抹到不同材质的包装材料表面,使用目前实验室及商品化试剂中可用的几种病毒采样缓冲液,应用不同的采样方式进行样品采集,检测采集到的病毒半数组织培养感染剂量(TCID50)并计算回收率。结果3种采样缓冲液中,Hank’s平衡盐溶液对病毒的回收率最高,其次为PBS缓冲液和MEM培养基。5种采样方法中,湿棉棒每涂抹待采物品表面一次后旋转棉签位置再进行下一次涂抹的采样方法获得的病毒回收率最高。利用优化后的采样方法在室温条件下对病毒污染后的不同材质的包装材料表面进行病毒采样,结果显示,光滑塑料和金属材质表面的活病毒回收率分别为10.47%和3.55%,而从硬质塑料、厚纸板、牛皮纸及木板材料表面无法回收到活病毒。而对食品冷冻前后及不同场景的研究表明,光滑塑料表面在食品冷冻前后污染的病毒回收率分别为92.03%和4.83%,金属表面则分别为1.27%和4.94%;而硬质塑料表面仅在食品冷冻前被病毒污染的场景下可回收到活病毒,回收率为2.26%;厚纸板材料仅在食品冷冻后被病毒污染的场景下可回收到活病毒,回收率为1.27%。结论从物体表面回收活病毒情况依物表基质不同而异,该方法适用于较光滑的“硬质包装材料表面”污染活病毒的采集。利用上述优化的采样方法可有效回收冷冻食品硬质包装材料表面污染的活病毒。

Objective The sampling method of virus on food packaging surfaces was optimized.The virus recovery rate on different material surfaces was studied by simulating different scenes of virus contamination on the surfaces of frozen food packaging materials.Methods The virus was evenly coated on the surfaces of different materials in different scenarios.Different buffers and different sampling methods were used for sampling residual virus.The virus recovery rate was calculated by virus titer(TCID50).Results Among the three sample buffers,Hank’s balanced salt solution had the highest virus recovery rate,followed by PBS buffer and MEM media.Among the five sampling methods,the highest recovery was to apply the wet swab once on the surface and then rotated for the next swabing.Using the optimized sampling method to sample virus from the surfaces of different materials,the recovery rates of smooth plastic surface and metal surface were 10.47%and 3.55%,while the living virus of hard plastic surface,thick cardboard surface,kraft paper and wood surface could not be collected.The virus recovery rates of contaminated food on smooth plastic surface before and after frozen were 92.03%and 4.83%,and that of and metal surface were 1.27%and 4.94%.In addition,the recovery rate of hard plastic surface was 2.59%in contaminated food before frozen,and the recovery rate of thick cardboard surface was 1.27%only in the contaminated food after frozen.Conclusion The virvs recovery rates varies depending on the substrate of surfaces.This sampling method is suitable for collecting virus from smooth"hard surfaces".The residual virus on frozen food packaging surfaces can be effectively collected by the sampling method optimized above as well.