Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: INTERVENTION TECHNOLOGIES FOR MINIMALLY PROCESSED FOODS

Location: Food Safety and Intervention Technologies Research

Title: High pressure inactivation of human norovirus virus-like particles: evidence that the capsid of human norovirus is highly pressure resistant)

Author
item Fangfei, Lou
item Huang, Pengwei
item Neetoo, Hudaa
item Gurtler, Joshua
item Niemira, Brendan
item Chen, Haiqiang
item Jaing, Xi
item Li, Jianrong

Submitted to: Applied and Environmental Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/16/2012
Publication Date: 5/15/2012
Citation: Fangfei, L., Huang, P., Neetoo, H., Gurtler, J., Niemira, B.A., Chen, H., Jaing, X., Li, J. 2012. High pressure inactivation of human norovirus virus-like particles: evidence that the capsid of human norovirus is highly pressure resistant. Applied and Environmental Microbiology. DOI: 10.1128/AEM.00532-12.

Interpretive Summary: Human norovirus is a pathogenic virus, and a leading cause of intestinal illness worldwide. High pressure processing has been considered a promising non-thermal processing technology to inactivate food- and water-borne viral pathogens. Due to the lack of an effective cell culture for human norovirus, the effectiveness of high pressure processing on inactivating human norovirus remains unknown. Therefore, developing a new model system to evaluate the survival of human norovirus is urgently needed. We evaluated the effectiveness of high pressure processing on disrupting the structure and function integrity of virus-like particles, non-pathogenic particles that resemble human norovirus. We evaluated them by direct examination via electron microscopy and by measurement of the binding ability of the treated particles. Pressurization at 500-600 megapascals (MPa) was not sufficient to disrupt the structure and function of these particles, even with a very long holding time of 60 min. The disrupting efficacy of high pressure processing increased with the pressure level. The time required for a complete disruption of the particles at 700, 800, and 900 MPa was 45, 15, and 2 min, respectively. Pressure-treated particles are better able to bind to type A blood antigens than to the types B and O blood antigens. Additionally, smaller particles appeared to be much more stable than the larger particles. A treatment of 800-900 MPa is capable of effectively disrupting the structure of the human norovirus within a short holding time. The virus-like particles therefore represents a better model than two commonly used model organisms, the murine norovirus and the feline calicivirus. With a better model to work with, high pressure processing can be more effectively developed as a method to inactivate human pathogenic viruses on food.

Technical Abstract: Human norovirus (NoV) is the leading cause of non-bacterial acute gastroenteritis epidemics worldwide. High pressure processing (HPP) has been considered a promising non-thermal processing technology to inactivate food- and water-borne viral pathogens. Due to the lack of an effective cell culture for human NoV, the effectiveness of HPP on inactivating human NoV remains unknown. Therefore, developing a new model system to evaluate the survival of human NoV is urgently needed. Using human NoV virus-like particles (VLPs) as a model, we evaluated the effectiveness of HPP on disrupting human NoV based on the structure and function integrity of VLPs by electron microscopy and histo-blood group antigen (HBGA) receptor binding assays. We found that pressurization at 500-600 MPa for 2 min, a pressure level that completely inactivates the murine norovirus (MNV) and feline calicivirus (FCV), was not sufficient to disrupt the structure and function of human NoV VLPs, even with a holding time of 60 min. The disrupting efficacy of HPP increased with the pressure level. The time required for a complete disruption of human NoV VLPs at 700, 800, and 900 MPa was 45, 15, and 2 min, respectively. The human NoV VLPs are more resistant to HPP in their ability to bind the type A than the types B and O HBGAs. Additionally, the 23-nm VLPs appeared to be much more stable than the 38-nm VLPs. While human NoV VLP is highly resistant to HPP, a level of 800-900MPa is capable of effectively disrupting human NoV capsid within a short holding time. The apparent high resistance of human NoV capsid to HPP also indicates that the human NoV VLPs represents a better model than MNV and FCV to study the survival of human NoV under various conditions.

Last Modified: 8/24/2016
Footer Content Back to Top of Page