New, Faster Salmonella Detector Developed at Auburn University

Researchers from Auburn University have developed a device which can detect the presence of the salmonella bacteria in real time -- whether in the fields or in the factory. The technological advancement comes as welcome news as the most recent salmonella outbreak in the US sickened more than 300 people across 20 states.

The new device, which is detailed in the Journal of Applied Physics, is a system that employs a "magnetoelastic biosensor" -- basically a low-cost, wireless acoustic wave sensor -- to detect the presence of salmonella. The biosensors are coated with a layer of "phage," a virus that naturally recognizes bacteria. The specific type of virus coating the sensors can vary depending on which bacteria the device is being used to test for.

The biggest advancement for the new detection device is its speed. Old salmonella detectors work slowly, but the new design can yeild results much faster, said Yating Chai, a doctoral student in Auburn University's materials engineering program who was involved in the development of the device.

Traditional mechanisms required the sensor to be inside a coil in order to make accurate measurements.

"The key to our discovery is that measurement of biosensors can now be made 'outside the coil' by using a specially designed microfabricated reading device," Chai explained.

"In the past, if we were trying to detect whether or not a watermelon was contaminated with salmonella on the outside of its surface, the sensors would be placed on the watermelon, and then passed through a large coil surrounding it to read the sensors," Chai said.

But the new system is a handheld device that can simply be waved across the surface of an item; making contact is not required.

"Now, tests can be carried out in agricultural fields or processing plants in real time -- enabling both the food and processing plant equipment and all surfaces to be tested for contamination," Chai added.

The speed and ease with which the new detecting device works could eventually be of great benefit, should the design be adopted into widespread use.

Foodborne illness can be a difficult-to-control problem, especially in developing nations. Quick detection of bacteria causing illness will play a critical role in stopping contamination, which is good news, even in America where about 48 million people contract a foodborne illness every year, according to CDC data.