STORY SOURCE: Dr. Daniel Lim, (813) 974-1618
Media Contact: Marsha Strickhouser,(813) 974-9051, e-mail: [email protected]
USF researchers use high-tech biosensors to assess food and water safety
TAMPA, Fla. (March 16, 2001) - Using portable fiber optic biosensors, lasers and a computer, researchers at the University of South Florida can immediately find diseases that can threaten public health, including those caused by E. coli, Listeria, Salmonella, Cryptosporidium and Camphylobacter.
The state-of-the-art machine, no bigger than a car battery, can now detect food-borne pathogens in minutes, rather than days, said Daniel Lim, a professor in USF's Department of Biology and Department of Environmental and Occupational Health.
Approximately 5,000 people die each year due to food-borne pathogens, said Lim.
"Much of the morbidity and mortality can be prevented with more timely methods to detect food-borne pathogens," Lim said in an article in the National Food Processors Association Journal this past October.
In the past, it could take 24 to 72 hours to get results. Now Lim and his researchers use "real time" to get their results, which uses state-of-the-art techniques that can respond immediately. Now scientists can get results from the biosensor within 20 minutes.
"We've looked at many methods over the years in attempts to find better and faster ways to detect the pathogens. The biosensor is the fastest technique that we have found thus far. It is a revolutionary breakthrough in pathogen detection," said Lim.
"Such modern technology for real time/near time detection of pathogenic microorganisms will play increasingly important roles in the food industry, reduce morbidity and mortality rates from food-borne disease, and enhance food safety programs," said Lim.
USF is one of only a handful of centers in the country to have this machine, which is made by Research International in Woodinville, Wash. The U.S. Army and the Naval Research Laboratory also have the machine. USF serves as the microbiology research arm of this program for Research International, said Lim.
At the Naval Research Laboratory, the same biosensors have been used to identify toxins from Iraq. It was also used at the World Trade Organization Conference in Seattle for use in the possible detection of bioterrorism threats such as anthrax.
Lim's laboratory is considered one of the leading biosensor laboratories in the world. Microbiologists here have given tours to scientists from all over the country and world, and recently to Japanese companies worried about food poisoning in food processing plants. The USF lab boasts $2.5 million in funding from agencies such as the National Science Foundation, the Department of Defense, the U.S. Environmental Protection Agency and the Water Environment Research Foundation.
Lim's lab helps locally in ways that affect everyday lives.
For example, when area beaches are closed due to high coliform counts in the water, the counts aren't for specific pathogens.
"Unfortunately, during this delay, water conditions are not stable," said Lim. "As rainfall and tides change, coliform counts can also change; and at the same time, the beaches are closed, therefore hurting tourism. The device we have not only can detect specific pathogens such as E. coli and Salmonella, it can do so within a few hours, thereby providing more accurate and timely information," said Lim.
The biosensor can help in the food industry, also. Meat plants can only recall meat when they think it might be contaminated or tainted.
Before, scientists could detect a bacteria from food samples only after the bacteria had been grown for 1-2 days to a least a million organisms, Lim said. The bacteria also had to be separated or isolated from the food sample, which also caused delay.
"The beauty of this new procedure is two-fold," said Lim. "It can detect very small numbers of bacteria - as few as several hundred bacteria - within minutes, not days. And it can detect these bacteria directly from samples of sewage, beach water or food."
Lim is working with Pinellas County environmental engineers to use the biosensor to detect beach pathogens. Nationally, he is working with the Environmental Protection Agency, including possible work in Santa Barbara, Calif., to look at the quality of their beach water.
The Florida Department of Health will soon occupy a new laboratory building located in an area of the USF Research and Development Park. This laboratory, which processes environmental and clinical samples for health departments in this region of Florida, would provide a facility for testing new techniques such as Lim's biosensor.
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