A paper-based test that can diagnose drug-resistant tuberculosis rapidly is the goal a UT professor and his research team plan to pursue with the help of a recent grant.
The Bill & Melinda Gates Foundation awarded the Grand Challenges in Global Health grant to cellular and molecular biology professor Andrew Ellington’s team, as well as 21 other groups of researchers working to improve world health conditions. Ellington and his team of eight researchers were awarded the $1.6 million grant Dec. 16. Ellington’s test, if successful, would have the greatest impact on countries lacking effective point-of-care diagnostic systems, said John Bernardo, chair of the World Health Organization’s initiative Stop TB USA. Bernardo said these systems make diagnosing tuberculosis difficult, but the test would make it simpler.
Tuberculosis is an infectious disease caused by strains of bacteria affecting the lungs and spreading to the rest of the body and characterized by symptoms of coughing up blood, fever and weight loss. In the United States, testing is conducted by culturing a sample taken from the patient in a laboratory, but in countries where adequate infrastructure is lacking, testing is often conducted by using smears of mucus from the body’s lower airways, he said.
“Currently it takes days to confirm tuberculosis in this country and it takes even longer in countries abroad that are often poorer countries that lack appropriate infrastructure,” Bernardo said. “There’s no way to rapidly diagnose the disease and what we need is a rapid diagnosis method. A rapid field test that doesn’t require diagnostics involving cultures or refrigeration and would indicate drug-resistance would be most beneficial to these poorer nations.”
Smears also do not detect drug-resistant tuberculosis, although knowing patients’ resistance status is vital to proper treatment, he said.
“These tests aren’t very accurate, because there are other bacteria that may also resemble TB on the smear,” Bernardo said. “If you don’t use the correct drug or combination of drugs, it will have no effect, and if it is pulmonary tuberculosis, then it can still be spread to other people by breathing.”
Bernardo said tuberculosis, when counted with patients co-infected with HIV, kills more people each year than any other infection in the world.
The need for a more accurate, point-of-care, portable test that can be done without refrigeration was communicated to Ellington by one of his former students, Grace Eckhoff, a UT biology 2010 alumnus. Eckhoff interned in Afghanistan and studied drug resistant tuberculosis.
“She would go and tell us her challenges,” Ellington said. “It was her work that inspired us.”
Xi Chen, post-doctoral research associate for the project, said the team will try to accomplish the low-cost, yet accurate diagnostic tool by forgoing the use of enzymes that are expensive to mass-produce and focus on newer techniques.
“Instead, we propose to use short nucleic acids, also known as oligonucleotides, which can be made in very large scale with relatively low cost,” Chen said. “The key concept of our approach, called DNA circuitry, which makes nucleic acid-only, enzyme-free diagnosis theoretically possible, has only been developed in recent years.”
Ellington said his team’s work is likely years from completion, and David Laude, interim dean of the College of Natural Sciences, said the diagnostic technology Ellington develops would rely on a network of health care professionals to reach
“Like many scientists, Ellington’s work will be cumulative with the work of many others,” Laude said. “The directions he’s taking, if they are taken up by health care organizations, could directly affect people’s lives. But that is still a long ways off, and again will require the concerted efforts of many individuals, most of whom are not scientists but who contribute much more effectively and directly to public health.”
Printed on Thursday, January 19, 2012 as: Tuberculosis research team receives grant to fund study