Study of high-pressure process to inactivate Norwalk virus underway


Blacksburg, Va. Virginia Tech's High Pressure Processing Laboratory is part of a $600,000 study of the effects of high hydrostatic pressure in inactivating Norwalk virus in seafood, funded by the U.S. Department of Agriculture's Cooperative State Research, Education, and Extension Service to study.

The laboratory is a facility of the Department of Food Science and Technology, devoted to improving food safety and food processing. Virginia Tech will collaborate with the USDA Agricultural Research Service (ARS) Microbial Safety of Aquaculture Products Center of Excellence in Dover, Del. and the Rollins School of Public Health at Emory University in Atlanta.

Norwalk and Norwalk-like viruses (collectively 'noroviruses') are the most common cause of food borne disease outbreaks in the United States, with 22 million cases reported annually. Disease is characterized by nausea and gastroenteritis, and usually passes in 2-3 days with no long-term effects. The disease is rarely fatal, but dehydration can become dangerous in rare cases. In the United States, most outbreaks are linked to consumption of raw oysters and clams, contaminated water, raw salads, and ready-to-eat foods. Noroviruses are resistant to detergents, solvents, high temperatures and freezing, and are extremely contagious.

Researchers Daniel Holliman, an M.D. working in the Virginia Tech lab; George Flick, university distinguished professor of food science at Virginia Tech; Christine Moe of Emory University; and David Kingsley and Gary Richards of USDA/ARS will identify one or more high pressure processing schedules resulting in virus inactivation. Co-PI Angela Correa of Virginia Tech will develop a suite of education and outreach materials on the applications of high pressure for human pathogen reduction in foods.

The study will also evaluate murine norovirus-1 (MNV-1) as a research surrogate for human norovirus, specifically Norwalk virus. Results obtained from human subjects will be compared to those obtained using mice to determine if the mouse model is equally effective for determining rates of virus inactivation achieved through high pressure processing. Validation of a murine model would greatly simplify future research on noroviruses.

Most importantly, the study should make consumers safer from foodborne infectious disease.

Other funded research projects under way in the lab include "Use of High Hydrostatic Pressure Treatments to Eliminate Vegatative Pathogens in Fresh Crabmeat and Spores and Spore Forming Pathogens in Fresh Crabmeat and Shrimp," "The Effect of High Hydrostatic Pressure Processing on Microbial Quality, Shelf-life Extension, Drip Loss, and Physical Characteristics of Eastern Oysters (Crassostrea virginica)," and the Gulf Oyster Industry Program: "The Use of High Hydrostatic Pressure to Inactivate Hepatitis A virus in Gulf Coast Oysters (Crassostrea virginica)."

Faculty members and students are also researching the effects of harvesting, processing, and distribution on the formation of histamine, and other biogenic amines in major commercial mid-Atlantic fish species; the presence and dynamics of Listeria monocytogenes and other Listeria species in ready-to-eat fish and shellfish products (i.e., smoked fish, crab meat, shrimp); effects of varying high processing pressures on the inactivation of the spore forming microorganism Bacillus cereus; and the identification of microorganisms surviving high pressure treatments in various fresh and processed foods.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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