DETECTING MICROBES CAUSING food-borne disease isn't as easy as you might think.

Even though the food industry spends billions of dollars attempting to safeguard the food supply, food-borne disease is blamed for thousands of deaths each year.

But Hua Wang is hoping to change that. With colleagues including professors Ahmed Yousef and Steve Schwartz, her work is funded in part by the Center for Advanced Processing and Packaging Studies, the OARDC equipment fund, and from start-up funds she received when she joined the university.

Wang, an assistant professor of food science and technology, is developing a rapid testing system to detect food-borne microorganisms. The system is based on a cutting-edge technology called "real-time PCR" that can be used to quickly identify signature DNA sequences from microbes that cause food-borne disease or spoilage.

"PCR is for Polymerase Chain Reaction," Wang said. "It takes a selective DNA fragment and amplifies it. Previously, it took 18 hours or longer for bacterium to grow from one cell to a colony and further to characterize what it is. With PCR, amplification can take place in minutes."

Traditional PCR techniques have been around for a decade but generated too many false positives, Wang said. Real-time PCR modifies the technique in a way that reduces the chance of false positives by 99.9 percent. With the new technique, scientists like Wang develop primers and probes that are specific for the microbes they're looking for. When a specific probe, about 15 to 30 base-long nucleotides, binds to the right PCR product from the microbe in question, a fluorescent signal results.

The hope is that protocols under development can catch pathogens such as E. coli O157:H7 in ground beef or Listeria monocytogenes in hot dogs and lunchmeat before the foods reach market. That would save lives and millions of dollars, Wang said.

"Traditional methods just take too long. Sometimes foods can be spoiled if held until the results come back," Wang said. "And detecting the presence of a tiny amount of pathogens in food can be very difficult."

Shari Plimpton agrees. As program manager for the Center for Innovative Food Technology, a division of Edison Industrial Systems Center, Inc., Plimpton works with the food industry to help them implement new technologies.

"We estimate right now that there are probably anywhere from 6 to 33 million cases of food-borne illness in the United States, and that alone can represent $3 billion to $6.5 billion worth of savings to be able to prevent that kind of illness," Plimpton said.

Food spoilage from microbes is a major issue as well, Plimpton said. "To be able to detect the microorganisms and keep those products from spoiling as quickly, we can expect the savings would be at least in the $5 billion to $6 billion range, if not higher."

The catch? Probes must be developed for each targeted microbial group, and protocols must be refined for each food product. Looking ahead, Wang sees several years of laboratory work. "Then it's up to the industry and regulatory agencies to implement and set up the standards for how to use this technology," she said. "We hope within a few years this technology will see application."

Samples are ready to be tested in Hua Wang's lab.

Hua Wang sees much promise in a technique that can reduce food spoilage and food-borne illness.

Preparing samples for real-time PCR analysis takes legwork, but the process could prevent many food-safety and spoilage problems.

Doctoral student Hongliang Luo helps refine a process that identifies DNA fingerprints from food contaminants.