DNA fingerprinting of plants and animals is performed for food security, food safety, identification and parentage. In food animals, DNA fingerprinting can be used to trace meat to the source animal. The technique can be used to identify endangered and non-endangered fish species, while the sources of plants can be verified to prevent counterfeiting of seeds and stock. Pathogenic food organisms can be quickly identified by their DNA fingerprints, allowing doctors to provide timely, targeted treatment.
Tracking polluted water back to the source of its contamination can help researchers assess potential health risks and determine methods for cleaning up the affected water. Now those same techniques can be utilized to keep food safe.
For about a decade, researchers have used a technique called microbial source tracking to trace water pollution back to its source. One of those researchers, Dr. Alexandria Graves, a soil scientist at NC State, collects genetic libraries of varieties of bacterial pathogens like E. coli from water samples and then cracks their DNA code to look for similar genetic “fingerprints†in the environment. In an admittedly simple example, if specific genetic fingerprints in an E. coli sample from polluted water downstream from a hog lagoon match those in or near the lagoon, that evidence can point the finger at the lagoon as the source.
Similarly, researchers are also trying to track the sources of the harmful pathogens that can contaminate food and cause illness – common microbes like E. coli, Salmonella and Enterococcus faecium, many of which are already resistant to antibiotics and are increasingly resistant to food-preservation measures. Food-borne diseases are responsible for an estimated 76 million illnesses and 5,000 deaths each year in the United States, according to estimates published in 1999.
