Jul. 17 2017

Researchers Develop Yeast-Based Tool for Worldwide Pathogen Detection

Columbia University researchers have developed a tool to detect and treat pathogens in everything from human health to agriculture to water. Using only common household baker’s yeast, they 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. The study appears in the journal Science Advances.

The biosensor allows the researchers to detect a pathogen for less than one cent per test. Easy to use, cheap to produce with no cold storage facilities required, it stands to impact agriculture and health, especially in developing countries, where it is arguably needed the most.

Fungal pathogens  -- known as ‘hidden killers’-- present an increasingly urgent public health burden, causing an estimated two million deaths annually and inflicting devastating losses on plant crops and population decline in animal wildlife. The devastation is most pronounced in resource-poor areas where efforts to reduce infections have been hampered by the scarcity of cost-effective fungal diagnostics. Still, fungal pathogens and the diseases they cause are often neglected and research to combat them is underfunded.

In close collaboration with experts in public health, including Alastair Ager, PhD, Mailman School of Public Health adjunct professor of Population and Family Health, the team of investigators and students swapped out naturally-occurring cell surface receptors of Saccharomyces cerevisiae, or baker’s yeast, with pathogen-specific receptor proteins. 

“We realized that the same household baker’s yeast people use every day to brew beer and make bread could be programmed to detect a myriad of targets,” said Columbia University chemist Virginia Cornish, principal investigator. “We can now alter the DNA of the baker’s yeast to give it new functions that make it useful for a variety of applications. The prospect of using this technology in rural communities with little access to high-tech diagnostics is particularly compelling.” 

The project which began as a search to find a cost-effective, simple way to detect cholera, quickly evolved to address other needs including the ability to detect eleven major pathogens. In each case, their assay functioned accurately without sacrificing any of the sensitivity and specificity attainable with other, significantly more expensive tests.

“This is a great example of collaboration between cutting-edge laboratory science and field-focused global public health producing a potentially game-changing innovation,” said Dr. Ager, who is currently deputy chief scientific adviser to the UK Department for International Development advising on global health research investments.

The Columbia team is currently in conversations with global health non-profits and worldwide research, technology, development and citizen groups to determine the needs of specific countries. They believe there are many more applications for their sensor, including use in virus and bacteria detection, and a biosensor for cholera is in the works to aid in African surveillance efforts.