Chemistry Professor Discusses Fight Against Tuberculosis


On Nov. 16, for the last lecture of the semester in the Natural Science and Mathematics (NS&M) Colloquium Series, Cynthia S. Dowd, a researcher and assistant professor of chemistry at George Washington University, provided information about the therapeutics that are now being used to combat Mycobacterium Tuberculosis (TB).

The deadly disease tuberculosis has affected the world for hundreds of years.  “There have been traces of TB found in Egyptian mummies dating back to 3000 or 2400 B.C.,” said Dowd. She explained that TB is a disease of the lungs with symptoms including weight loss and a cough that contains blood. It is a contagious disease that can be passed from the infected person through coughs and sneezes. “Tuberculosis kills two million people per year,” Dowd stated.

TB is a tough disease to fight because there are two strands of it, latent and active. Dowd explained that with latent TB, the person is just a carrier and does not exhibit any symptoms. However, latent TB can become active if a person contracts Human Immunodeficiency Virus (HIV). Dowd remarked, “In the world, there are over eight million active cases of tuberculosis, but two to three billion cases of latent TB.” So far, nothing has been found that will permanently kill latent TB.

Other issues that come with fighting TB are the drugs used to attempt to do so. “TB will never be a disease killed by one drug only,” said Dowd. In fact, eliminating TB involves at least six months of two different phases and six different drugs. But in many cases of TB, the patient will exhibit a resistance to the drugs. Dowd’s lecture focused on how researchers are currently developing drugs to combat tuberculosis that will shorten the duration of therapy, be effective against resistant strains, and kill both active and latent TB cells.

Designing a drug to combat mycobacterium tuberculosis is a difficult process. Because TB has a thick cell wall, it is hard to find something that will break through it. But the silver lining is, “Since TB is old, there is a lot of information known about steps that should be taken in the drug making process,” Dowd stated. This has helped researchers locate an essential enzyme that should work against latent and active TB: 1 deoxy-d-xylulose 5-phosphate reductoisomerase (DXR). This is an inhibitor that should get around the cell wall by changing the structure of the molecules. Researchers have conducted tests and are doing all they can to stop mycobacterium TB.

Those in attendance at the lecture were glad to hear about the developments in this long battle against TB. Elizabeth Lee, a junior, was excited that Dowd provided a continuation of what she was learning in her bio-chemistry class. “Since we’re talking about inhibitors in class I enjoyed the real life application. It was really interesting.” Lee said. Everyone expressed their gratitude to Dowd for sharing her research.