December 1999: Vol. 79, No. 1December 1999: Vol. 79, No. 1 |
 SPROUTS ARE A NO-NO NOW  Pile on the lettuce, tomatoes, carrots, and onions. Add plenty of croutons and dressing. But the next time you're making that mouth-watering salad, think twice before you load up on the alfalfa sprouts. "The procedures for disinfecting seeds and sprouts aren't totally effective," says UGA food safety researcher Larry Beuchat. "If you have one cell of a pathogen (e.g., Salmonella or E. coli) present in one seed, then by the end of the production process there may be a million or more cells of the pathogen per gram of finished product." And since sprouts aren't commonly cooked, there's no step to kill the harmful bacteria. "The overall risk is low," says Beuchat, "but it's definitely there."  Stacie Sutton
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If the work of UGA researchers pans out, fish could soon replace, or at least supplement, mice for screening chemicals in the lab. A team of toxicologists has transferred genes from bacteria into the Japanese medaka, a tiny freshwater fish previously used for cancer research, to help evaluate the genetic health risks of chemicals in the environment.
 Experimenting on fish is cheaper than on lab mice, says Winn, and less sensitive, politically. |
"Transgenic fish offer nearly every kind of exposure route as mice. In tests, they can be exposed at low-dose, realistic levels," says Richard Winn, an environmental toxicologist in UGA's Warnell School of Forest Resources.
Winn says fish are also cheaper to use, costing just "pennies a year," compared to about 20 cents a day to maintain lab mice. Fish are also "less sensitive, politically, than mammals for use in biomedical research."
Transgenic fish carry specific DNA sequences that serve as targets for DNA damage or mutations. Researchers expose the fish to a potential contaminant, then analyze tissues for mutations in the indicator bacteria. Because the same detection system is used in lab mice, Winn said comparative studies are currently possible using two different species.
Fish can be used for screening organic materials such as PCBs, as well as heavy metals, radiation, herbicides and pesticides. They are especially useful, Winn said, in toxicity screening the more than 2,000 new chemical compounds introduced in the market each year.
Winn's group has funding through the Georgia Biotechnology Center of the Georgia Research Alliance for the $1.3 million Aquatic Biotechnology and Environmental Laboratory—to be built at the Warnell School's Whitehall Forest. The facility will serve as a national center for multi-disciplinary research; it will help in the development and transfer of technology and emerging industries; and it will include aquatic toxicology laboratories for biological testing under highly controlled environmental conditions. The lab will accommodate fresh- and saltwater species, including specialized strains developed for aquaculture, environmental hazard assessment, biomedicine and biotechnology.