At the Health Sciences Center, associate professor Dr. Graham Timmins is continuing to make advances by developing a breath test that has the potential to determine if someone has TB within minutes.
By sampling the breath of the animals Timmins said he was able to tell 100 percent of the time whether or not an animal was infected with TB.
Typical TB tests require several weeks to reach a diagnosis, and in developing countries where medical facilities are few and ill-equipped, detection sensitivity can be as low as 40 to 60 percent, he said.
In an effort to speed up diagnosis time and improve sensitivity, Timmins developed a breath test that is the first of its kind for detection of TB, and has begun testing it on an animal model.
TB is a contagious bacterial infection, typically in the lungs, that can lead to death when left untreated. While it is a problem all over the world, its prevalence is particularly high in developing countries, Timmins said.
“TB is a huge worldwide problem. Probably a third of the world is infected with TB. Most of that is what’s called ‘latent infections,’ so you’ll get exposed to it and if your immune system is strong then most people mount an effective immune response,” he said. “But (in latent TB) the TB doesn’t die - it will stay with you forever.”
The disease can lie dormant indefinitely, but can become reactivated if a person’s immune system is dampened because of factors like poor diet, HIV infection, certain medications or even simply from getting older, Timmins said.
The test works by harnessing TB bacteria’s own actions. Most drugs used to treat TB are actually broken down by the bacteria during the process.
So, Timmins labeled a common antibiotic prescribed to TB patients, isoniazid, with a type of rocket fuel that contains an extremely rare gas molecule (15N2). The subject inhaled the labeled antibiotic into the lungs, where the TB bacteria broke the drug down.
This degradation released the gas molecule and the animal breathed it out. If the animal was not infected with TB then the drug was not broken down and the gas molecule was not released.
In order to analyze samples collected with this breath test, Timmins has teamed up with Zachary Sharp, a professor of Earth and planetary sciences at UNM. Sharp’s lab contains high-tech machines that he used mainly for geological studies until several years ago when Timmins asked to use his equipment and expertise for his project. They have been collaborating ever since.
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“(Timmins) is a brilliant, wonderful colleague,” Sharp said. “And he’s the first person from the medical side of campus to be using our equipment.”
One of the most exciting aspects of the breath test is its potential to detect whether a patient is infected with an antibiotic-resistant TB strain. While mortality rates for traditional TB are very low when treated, an antibiotic-resistant strain is much more dangerous, Timmins said.
According to the World Health Organization, resistance to antibiotics in TB bacteria arises primarily when people are either prescribed incorrect antibiotics, or when they fail to take the full course. This new resistant TB strain can then be transmitted to other people.
TB bacteria won’t degrade a drug it is resistant to, so a combination of antibiotics could be given to a patient, and resistance could be determined by whether or not they were broken down, releasing their individual signaling molecules and eliciting a unique profile for each strain of TB, Timmins said.
“That’s where we’re going, we’ve only established it for isoniazid, but theoretically there’s no real reason why we can’t do a bunch of other drugs as well,” Timmins said. “If you can look for four or five drug sensitivities all at once, that becomes quite valuable.”
The most effective way to prevent resistance from developing and the disease from spreading is to identify as many people with TB as possible and to determine as quickly as possible whether their infection is drug-resistant, he said.
Timmins said he hopes this test can eventually be adapted to be used easily all over the world.
“There’s every reason to suspect that we could make this a portable device,” explained Timmins.
Sharp shares Timmins’ enthusiasm and expects to continue working together in the future.
“I think it’s just great, I think it’s an important breakthrough to be able to make this diagnosis quickly and accurately, and we’re excited about moving forward,” Sharp said.
Lauren Topper is a freelance reporter at the Daily Lobo. She can be reached at news@dailylobo.com, or on Twitter @lauretopps.
