Tuesday, October 12, 2004

"BIOSENSOR: slashes time to detect Listeria bacteria"
A fiber-optic biosensor that reduces testing time for a deadly form of the Listeria bacteria from one week to less than 24 hours has been created by two Purdue University microbiologists and a control engineer. Listeriosis kills one in five that it infects and accounts for the highest rate of hospitalization and mortality among foodborne illnesses. Usually, when the (monocytogenes) Listeria bacteria is detected in a food sample, it has already been on store shelves for up to a week, because the detecting sensors are so crude that the food has to be cultured in petri dishes for that long before enough bacteria multiply to trip the alarm. "We still need to culture the food sample with our new biosensor, but for a much shorter time-less than a day," said Arun Bhunia, associate professor of food microbiology. Bhunia developed the sensor with Tao Geng, research associate in the Department of Food Science. Mark Morgan, an engineering professor in Purdue's Food Science Sensors and Controls Laboratory, also participated in the research. "Instead of having to recall food that is already on the shelves, we want test results before it gets delivered to stores," said Bhunia. The researchers are aiming eventually for real-time operation of the biosensor.