A new Salmonella detection test developed at Iowa State University can shorten the time to detect salmonella. Using a tape like paper to pull bacteria from the food source, then a soapy, salty water mixture is applied to the tape and in two hours an ultraviolet light source will cause the salmonella will give off a green-fluorescent glow.
It’s inexpensive, quick and easy.
Researcher Byron Brehm-Stecher and Bleda Bisha developed the test through the college of Food Science and Nutrition. For more information contact contact Byron Brehm-Stecher, Food Science and Human Nutrition, (515) 294-6469, [email protected] or Dan Kuester, News Service, (515) 294-0704, [email protected].
Brehm-Stecher's and Bisha's findings will be published in the journal Applied and Environmental Microbiology, published by the American Society of Microbiology.
Once at a location where an outbreak of salmonella has occurred, investigators can test the produce for contamination. Outbreaks can be due to other factors such as food preparation.
Once investigators find the origin of the salmonella, they can take steps to contain it, said Brehm-Stecher.
Salmonella can be found on produce such as tomatoes, cilantro, peppers, spinach and others. The produce can be contaminated while it is in the fields or during processing. Washing the produce thoroughly can help, but cannot ensure the produce will be safe.
The tape-FISH technique can also be used to test produce that is not suspected of being contaminated, but the volume of produce that would need to be tested may make this impractical. However, the technique could be very valuable as a basic research tool. Researchers could investigate how salmonella and other types of organisms interact on produce surfaces, said Brehm-Stecher.
This is the first application of tape-FISH to salmonella, but the idea came to the ISU researcher while reading about art restoration.
In 2008, Brehm-Stecher read about an Italian group that was using a similar approach to look for bacteria on ancient catacombs. Those researchers were hoping to identify and remove bacteria that were slowly eating away at the relics.