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November 8, 2014

DNA the new weapon against food-borne illnesses

By Stephanie M. Lee
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Featured in the San Francisco Chronicle

To prevent and contain outbreaks of food-borne illness, which sicken 1 in 6 Americans annually, a Bay Area startup is developing bar codes that go directly on fruits and vegetables. But you may overlook them: they’re DNA-size.Using technology invented at Lawrence Livermore National Laboratory, DNATrek is creating liquids that each contain a unique DNA sequence. The odorless, colorless and tasteless solution peppers the surface of produce, or blends into other oils and liquids, with a genetic bar code that can be identified by a special machine.The technology could solve the enormous challenge of tracing an outbreak’s source — the places where food items are grown, packed and shipped. When people start feeling the symptoms of salmonella or E. coli, many clues about the contaminated product’s origins, such as the shipment boxes, already have disappeared.

The Food and Drug Administration has already recognized the invention as a safe food additive, but for now, the industry does not use it. After large-scale tests that are set to begin next year, DNATrek believes that its tool will emerge as a powerful weapon against food-borne illnesses, which cost the country an estimated $150 billion a year in health-related expenses, and counterfeit food products, which cost the global industry $10 billion to $15 billion annually.DNATrek suggests that its bar codes may have come in handy in 2012, when an E. coli outbreak caused by contaminated spinach led 13 people to be hospitalized, and in 2011, when 33 Americans died after eating tainted cantaloupe.

“If there’s a problem at home and there’s a piece of the cantaloupe left, you can pick it out of the trash, you can scrub the surface, and all the available information is there and you know exactly where it came from,” said Anthony Zografos, founder and CEO of the self-funded, three-employee startup that expects to close a round of seed funding by the end of the month.

Safety concerns

Although the company says the DNA sequences are too tiny to be harmful to people or cause genetic changes to the food, some advocates worry they could have unintended consequences for human health and the environment. “DNA does not perform one task, but can have a myriad of unforeseen impacts,” Dana Perls, who tracks food and technology issues for the environmental group Friends of the Earth, said in an e-mail.

George Farquar, a physical chemist at Lawrence Livermore, patented the product in 2010 with about $3 million in research funding from the Department of Defense. Originally conceived as a biodefense tool, it combines FDA-approved foodstuffs, such as sugar, and a unique DNA sequence to create safe, inhalable microparticles for the purposes of tracking airflow indoors and outdoors. It has been used to test whether, for instance, air detection systems are able to notice particles that resemble anthrax. Last week, company executives and scientists traveled to the Pentagon to run their third series of tests.Zografos, a business strategist, got wind of the technology, licensed it and formed a company around it. The biodefense applications were important yet small, he realized, compared with the need for tools that track and maintain food safety.

Farquar and Zografos say growers, packers, shippers and others in the supply chain would spray food with their signature genetic bar code. Up for grabs is an infinite number of potential DNA sequences taken from nature or created in a lab. These would be combined with a safe-to-eat food additive, such as the waxes that are now sometimes added to the surfaces of apples and cucumbers.Should an outbreak or counterfeiting occur, the produce’s bar code would be detected and identified with a polymerase chain reaction technology, a relatively simple and inexpensive tool used in molecular biology. Regulators could deduce the route the produce had traveled and where the contamination might have begun.“In 15 to 20 minutes,” Zografos said, “you know exactly where it came from.”The spray will probably cost $1 for every 1,000 pounds of produce, which Zografos said would add up to significantly less than the costs of recalling produce and treating sickened consumers.The company stressed that sprinkling bits of DNA on an organism is not the same as genetically modifying one. And at roughly 100 base pairs long, the added DNA is too short to be a health risk or cause changes to the food item, the inventors say.

Different sequences

To ensure that no genetic changes will occur, the company said, DNA would not be paired with similar items: for example, a fruit would be coated with a sequence from a tree or a flower, not a fruit.

“There’s no risk at all to an individual from being exposed to the DNA,” Farquar said.But Perls, of Friends of the Earth, said the company’s plan to use numerous DNA sequences, instead of just one, “makes it that much more difficult to assess the predictable and unforeseen consequences.”“I am not clear that mixing the sequence with a substance that has been tested as safe necessarily means that any risks of the new DNA sequences would be rendered safe as well,” she continued. “It doesn’t seem like one would cancel the other out. These sequences are also designed to last. What is the impact of the new particles over time?”The spray stays on food for about seven weeks before fading away, unless it is scrubbed off before then, the company said. The company said it will seek to confirm safety and effectiveness during its upcoming pilot tests, which will be done in cooperation with growers and producers on five to six types of produce.To succeed, Zografos and his staff must satisfactorily address safety concerns, educate the public and persuade industry members to get on board, said Jennifer McEntire, chief science officer at the Acheson Group, a strategic consulting firm for food and beverage companies, and a member of the DNATrek advisory board.If it all works out, she said, the technology could bring a lot to the table.“Even if you’re not the producer that caused the problem, it would be really nice to be able to prove that 'I know it couldn’t have been me,’” McEntire said. “The flip side of the coin is to know quickly what was the problem and be able to pinpoint it and address it quickly.”Stephanie M. Lee is a San Francisco Chronicle staff writer. E-mail:

This post originally appeared in the San Francisco Chronicle. Read it here.