Goodbye 'R' rule? Oyster pathogen test may help make shellfish safer

October 14, 2009

( -- The oyster lover’s axiom of edibility -- that this shellfish is safest to eat in any month with an 'r' in it -- may soon become somewhat of a culinary anachronism, thanks to a new food-safety test developed with help from the University of Florida.

Oysters are typically considered safest to eat in cooler months (September through April) because the shellfish-infecting bacteria in the genus Vibrio flourish best in warm temperatures.

Even in the “r” months, slurping an oyster opens some people to infection from these bacteria, which can cause fever, nausea, abdominal pain, diarrhea and has even led to finger amputation when it’s given a chance to penetrate a cut or skin lesion.

However, a new quick and inexpensive developed by DuPont Qualicon and refined by UF’s Institute of Food and Agricultural Sciences could make weeding out pathogen-loaded oysters much more practical and efficient. Oysters are a $14 million industry in the Sunshine State, according to the Department of Agriculture and Consumer Services.

The test is based on a technology dubbed “quantitative ,” or QPCR diagnostics. Given a small sampling of oyster, shrimp or ahi tuna, the system tracks found in three harmful species of Vibrio by amplifying their DNA into large amounts that are easily detected.
This is the first time this technology could be used in detecting pathogens in seafood on an industrial scale. So, after initially developing the basic lab-bench test, DuPont turned to UF to prepare it for commercial use and regulatory approval.

“Whether you have raw oysters or if you’re trying to validate some sort of treatment method, the old way of testing these bacteria in oysters just isn’t very practical because it’s pricy and takes about a week,” said Anita Wright, a UF food science professor whose Florida Sea Grant work is validating and expanding applications of the new test for seafood processing and research purposes.

This USDA-funded research evaluates treatments such as freezing, high pressure, irradiation, or mild heating, and is funded by the Florida Gulf Coast Oyster Industry Council.

Wright will present findings from her work at the Oct. 17-23 biennial meeting of the Interstate Shellfish Sanitation Conference, followed by a workshop to demonstrate the methodology. Her findings will also be published in the next issue of the American Organization of Analytical Chemists.

The ISSC is a shellfish regulatory cooperation that will determine if the test is reliable enough to be used industrywide. If approved, the test could be an especially big boon for harvesters in the Gulf of Mexico, the source of a third of all U.S. oysters.

Warmer water temperatures and factors such as pollution make Vibrio species a major concern for Gulf-harvested shellfish. Forty percent or more of Gulf oysters carry these pathogens in the “non-r” months, according to the FDA.

Provided by University of Florida (news : web)

Explore further: Federal agencies say seafood safe

Related Stories

Federal agencies say seafood safe

December 10, 2005

Federal officials and officials from Alabama, Mississippi and Louisiana say there is no reason to be concerned over eating Gulf states seafood.

New method found to freeze oyster eggs

December 28, 2005

A new method of freezing Pacific oyster eggs could have major implications for the world's seafood industry, it was reported Tuesday.

New research study to shed light on emerging seaborne pathogen

January 21, 2009

A new research study at the University of Delaware seeks to determine why Vibrio parahaemolyticus, a microorganism that lives in seawater and is related to the bacterium that causes cholera, is expanding its range and virulence.

Vibrio bacteria found in Norwegian seafood and seawater

February 24, 2009

( -- While working on her doctorate, Anette Bauer Ellingsen discovered potentially disease-causing vibrios (Vibrio cholerae, V. parahaemolyticus and V. vulnificus) in Norwegian seafood and inshore seawater.

Recommended for you

A new form of real gold, almost as light as air

November 25, 2015

Researchers at ETH Zurich have created a new type of foam made of real gold. It is the lightest form ever produced of the precious metal: a thousand times lighter than its conventional form and yet it is nearly impossible ...

Moonlighting molecules: Finding new uses for old enzymes

November 27, 2015

A collaboration between the University of Cambridge and MedImmune, the global biologics research and development arm of AstraZeneca, has led researchers to identify a potentially significant new application for a well-known ...

Atom-sized craters make a catalyst much more active

November 24, 2015

Bombarding and stretching an important industrial catalyst opens up tiny holes on its surface where atoms can attach and react, greatly increasing its activity as a promoter of chemical reactions, according to a study by ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.