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United States Department of Agriculture

Agricultural Research Service

Research Project: Biology and Control of Human Pathogens on Fresh Produce

Location: Produce Safety and Microbiology Research

Title: Application of porcine gastric mucin-conjugated magnetic beads and polyethylene glycol goncentration and detection of human noroviruses from green onion and grape)

Author
item Zhang, Qiang
item Liangwen, Pan
item Li, Xing
item Fang, Yun
item Tian, Peng

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/6/2011
Publication Date: 12/6/2011
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.

Last Modified: 8/24/2016
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