Researchers develop yeast-based tool for worldwide pathogen detection

Columbia University researchers have developed a tool that is likely to revolutionize the way we detect and treat pathogens in everything from human health to agriculture to water. 

Using only common household baker's yeast, they've created an extremely low-cost, low-maintenance, on-site dipstick test they hope will aid in the surveillance and early detection of fungal pathogens responsible for major human disease, agricultural damage and food spoilage worldwide.

"Our biosensor allows us to detect a pathogen for less than one cent per test; it is easy to use, cheap to produce and doesn't require cold-storage facilities," said Principle Investigator and Columbia University Chemist Virginia Cornish. "It stands to impact agriculture and health, especially in developing countries, where it is arguably needed the most. We're excited about the possibilities."

The project began as a search to find a cost-effective, simple way to detect cholera, but quickly evolved to address other needs.

Cornish and a team of her students swapped out naturally-occurring cell surface receptors of Saccharomyces cerevisiae, or baker's yeast, with pathogen-specific receptor proteins. They started by building a biosensor for the detection of Candida albicans, a human fungal pathogen (a type of yeast) that occurs naturally in the human gut, but can cause serious medical problems and even death if the population gets out of control.

The experiment was a breakthrough success. The sensor turned red when exposed to the fungal target. The team had developed a functional, simple, highly-specific, one-component sensor using only yeast.