Dunedin researchers find way to kill drug-resistant strains of TB

Many TB infections come from drug-resistant strains that cannot be treated with antibiotics.
Photo: 123RF

Dunedin researchers have found a way to kill drug-resistant strains of tuberculosis, and the discovery could also help fight other diseases.

Tuberculosis is a deadly disease that infects millions of people each year. Many of these infections come from drug-resistant strains: forms of the disease that cannot be treated with antibiotics.

Killing around 4,000 people every day, tuberculosis was the deadliest infectious disease in the world until it was dethroned by Covid-19. Although it is rare in New Zealand, infecting only 300 people a year, it is disproportionately high in neighboring Southeast Asia and remains very difficult to treat.

But a new discovery from Natalie Waller, a PhD student at the University of Otago, and lead researcher Matthew McNeil could change that. With the right combination of antibiotics, McNeil said it’s possible to exploit weaknesses in previously impenetrable strains and prevent others from becoming resistant in the first place.

“We made two major discoveries,” he said. “The first is that we have found new ways to quickly kill drug-resistant strains of tuberculosis.”

When a pathogen becomes resistant to one specific antibiotic, McNeil said it sometimes becomes vulnerable to another. By identifying this weakness, the disease could be quickly eliminated.

“TB is a huge public health problem, there are around 10 million new cases each year worldwide, and around half a million are due to drug-resistant strains,” he said.

“They are very difficult to treat, treatment options are limited, those that are available are often very toxic and require much longer treatment times.”

McNeil said existing treatment for antibiotic-resistant tuberculosis could take up to two years, but their discovery could shorten that to weeks.

“The second [finding] is that we have new ways to combine different drugs to prevent drug resistance from occurring,” he said.

This discovery had promising implications for other drug-resistant diseases.

“Drug resistance is a big problem in other infectious diseases,” McNeil said. “[It] comes in many shapes and sizes, but some of the same principles can be applied to other pathogens, and in fact, other research groups are currently investigating ways to find weaknesses unique to these.

Although promising, the idea would require extensive testing before it could be used for treatment.

“The next thing is scaling up, so we’re going to see if these observations we’ve made in the lab translate to different animal models,” McNeil said.

“All is well, hopefully in the future there will be clinical trials around this work.”