GAINESVILLE---Just when you thought you'd heard enough about DNA testing from the so-called "Trial of the Century," University of Florida researchers are using the same science to police polluters.
With the oft-mentioned DNA "fingerprint" test, scientists at UF's Institute of Food and Agricultural Sciences are able to accurately point the finger at who is polluting water bodies by isolating E. coli bacteria in water samples and testing it for resistance to antibiotics and by testing its DNA.
"E. coli is present in the digestive tracts of all warm-blooded animals," said Mark Tamplin, a professor of home economics at UF/IFAS. "By testing the E. coli (present in fecal matter) for antibiotic resistance and looking at the DNA chains, we can tell if it is human pollution or animal pollution. Different animals will have different E. coli and will have greater DNA patterns because there are more animal species. Humans have fewer DNA patterns."
Tamplin and his research team, working with a grant from the U.S. Department of Commerce's National Estuarine Research Reserve System, studied pollution at two sites in Florida: Rookery Bay near Naples on Florida's southwest coast, and Apalachicola Bay, an oyster-harvesting area in North Florida.
About 90 percent of all Florida oysters are harvested in the Apalachicola Bay area. Lee Edmiston, research coordinator at the Apalachicola Bay reserve who helped collect water samples for the two-year survey, said bacteria from pollutants causes fecal coliform counts to rise. When the counts get too high, the state, fearing illness from consumption of raw oysters, closes the bay to oyster harvesting.
"There's always been a question as to whether the bacteria was natural or manmade," Edmiston said. "There was never a way to differentiate that before this research."