ARS | Publication request: Application of porcine gastric mucin-conjugated magnetic beads and polyethylene glycol goncentration and detection of human noroviruses from green onion and grape

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 6, 2011
Publication Date: December 6, 2011
Citation: Zhang, Q., Liangwen, P., Li, X., Fang, Y., Tian, P. 2011. Application of porcine gastric mucin-conjugated magnetic beads and polyethylene glycol goncentration and detection of human noroviruses from green onion and grape. Journal of Food Science. 33:241-245.

Interpretive Summary: Contaminated produce related norovirus (NoV) outbreak is a major public health concern. The development of a simple assay for concentrating and detecting NoV contamination in fresh produce that can be performed in a single day would be of great benefit to the producers and regulators of produce production. In this study, we developed a simple assay to concentrate NoV from green onion and grape samples that can be performed within a few hours. We identified buffers that significantly improve the release of virus from contaminated produce surfaces. We determined that the PGM-MB viral concentration method is both faster to perform and produced significantly better virus yields than the same-day PEG-precipitation concentration method. We also found that the PGM-MB viral concentration method even exceeds the virus yield of the overnight PEG-precipitation concentration method. Overall, the PGM-MB method takes significantly less time than current PEG precipitation methods, recovers a higher yield of NoV, and hence exhibits higher sensitivity.

Technical Abstract: Objective: To set up detection methods for norovirus in fruits and vegetables by using porcine gastric mucin-conjugated magnetic beads (PGM-MB) and polyethylene glycol 8000 (PEG8000) concentrating and detecting the norovirus in green onion and grape. Methods: The highest virus dilution given a positive Ct was assigned as 1RT-RCR unit, and a standard curve was constructed with the Ct value of 1 RTU 10, RTU 102 , RTU 103, RTU 104 , RTU virus dilution. The green onion and grape samples were inoculated by norovirus, concentrated with PGM-MB or PEG8000 method, and then detected with RT-PCR. Quantify the recovered norovirus with the standard curve. The recovery was analyzed by student t-test. Results: For green onions with high inoculation, the recovery of the two methods was similar; but for low inoculation, the recovery of PGM-MB method was higher than PEG8000, and the detection limit for PGM-MB method was lower. For grapes, PGM-MB method was better than PEG8000, as with higher recovery and lower detection limit. Conclusion: PGM-MB concentration is good, quick and easy, and suitable for detection of norovirus in fruit and vegetables.