Tuberculosis is a major public health problem. The deadly disease affects millions of people around the world annually, and no new medications have been discovered to fight TB in decades. But new research indicates that may be about to change.
Over the past four decades, the tuberculosis bacteria has evolved to be resistant to many, if not most, of the drugs used to curb the disease. So, to fight it, University of Lausanne researcher Stewart Cole says he and his team needed to come up with a new strategy to kill the TB-causing bacteria.
"We have demonstrated that there is an important enzyme which is required to build the cell wall of Mycobacterium tuberculosis," Cole says. "And our compound blocks this enzyme from acting."
When this enzyme is blocked, the cell wall gets assembled incorrectly, and the bacteria burst open, dying in the process. Cole says no other drug has exploited this enzyme in the cell wall of Mycobacterium tuberculosis.
One advantage of this strategy is that there's no similar enzyme in the walls of human cells. So there's little chance that the drug will make people sick.
"Thus far, we have tested the compound - which is called a benzothiazinone - in the test tube. We've tested it on bacteria grown under different conditions. We've tested it on bacteria growing within human cells in the laboratory, and we've also tested it in an animal model of tuberculosis in the mouse," Cole says.
Cole says the drug did a good job of killing the bacteria in all three kinds of tests. He says the next step is to do safety tests in humans. To do that, Cole and his team need to ask healthy people to take the drug to see that it does not make them sick.
"Then [we can] go on and see whether it's effective in people suffering from tuberculosis," Cole says. "So we are very close to the beginning of clinical trials."
Cole is part of what he calls a "virtual drug discovery company" called the New Medicines for Tuberculosis Consortium. A paper describing the consortium's finding is published in the journal Science.