UTA chemist to develop simple, paper-based test for drug-resistant TB

Developing a simple, paper-based test for drug-resistant tuberculosis (TB) is the goal of a University of Texas at Austin chemist, whose project just received a $1.6 million point-of-care diagnostics grant through Grand Challenges in Global Health, an initiative created by the Bill & Melinda Gates Foundation.

The Grand Challenges initiative seeks to engage creative minds across scientific disciplines to work on solutions that could lead to breakthrough advances for people in the developing world.

Andy Ellington, professor of chemistry, will seek to develop a system for rapidly diagnosing drug-resistant TB in areas that lack the appropriate infrastructure, such as parts of Afghanistan and Africa. His project was one of 22 Grand Challenges grants announced Dec. 16.

"New and improved diagnostics to use at the point-of-care can help health workers around the world save countless lives," said Chris Wilson, director of global health discovery at the Bill & Melinda Gates Foundation. "Our hope is that these bold ideas lead to affordable, easy-to-use tools that can rapidly diagnose diseases and trigger timelier treatment in resource-poor communities."

Diagnostics for many pathogens require refrigeration, several days to culture, or analysis in advanced laboratories. Ellington's goal is to develop a real-time test using a small strip of paper that does not require refrigeration.

"It is critical to have a point-of-care, real-time test that fits the technology climate of the place where it is used," said Ellington. "You have to do tests without refrigeration, and they need to be portable, cheap and disposable. Essentially, they need to be what a home pregnancy test is. Our diagnostic would be like that but for TB."

Unique to Ellington's approach is his attempt to build a diagnostic system using synthetic DNA embedded in paper. The DNA will work much like an integrated circuit in electronics, but in this case the signal it will amplify will be the presence of the TB bacteria in saliva.

Ellington says the ultimate goal of such "molecular computation" is to develop a DNA circuit that recognizes drug-resistant TB bacteria and produces a color easily seen by the naked eye. Appropriate interventions can then be made quickly for the patient and before the TB spreads further.

"From our research and that of others, we know what all the parts are that will make this work," Ellington said. "The problem we are working on now is making the circuit sensitive enough to the minute levels of TB bacteria in a normal sample and decreasing false positives."