The researchers, from the University of Sydney, Monash University and the University of Queensland, in Australia, University of Warwick in the UK, Colorado State University in the US and the Simon Fraser University, Canada, published their findings this month in Nature Communications.
Richard Payne, professor of chemical biology at the University of Sydney and an author of the study, tells SciDev.Net that the team focused on soil bacteria which inhibited other bacterial species. “All of our compounds are made by chemical synthesis, but inspired by the sansanmycin family of natural products produced by the Streptomyces sp. soil bacteria.”
“If we show that we can clear TB infection in vivo we hope to progress to pre-clinical studies.”
Richard Payne, University of Sydney
Tested in the laboratory, these recreated compounds, or analogues, proved to be effective killers of Mycobacterium tuberculosis which causes TB, Payne says.
“These analogues inhibit the action of a key protein needed to build a protective cell wall around the TB bacterium — currently available drugs do not target this wall-building protein,” Payne says. The analogues also effectively kill TB-causing bacteria inside macrophages, the cells in which the bacteria live in human lungs.”
It is too early to say whether the new compounds will lead to TB drugs. “So far we have only shown that the compounds have potent anti-mycobacterial activity in vitro and in macrophages,” Pane says. “If we show that we can clear TB infection in vivo we hope to progress to pre-clinical studies.”
Cost is a factor with the synthetic route taken by the team “too expensive for a TB drug that needs to be used in some of the world’s poorest nations,” Payne says.
Gregory Cook, professor of microbiology and immunology at the University of Otago, Dunedin, New Zealand, says the discovery could “really open up the possibility of producing a new class of compounds to combat drug-resistant TB.”
What is even “cooler,” he says, “is that the researchers discovered this compound by looking at natural products, in much the same way as Waksman discovered streptomycin in the 1940s”. Since sansanmycin is very specific for TB, resistance should not develop as quickly as with a broad-spectrum agent like streptomycin, Cook says.
In 2015, there were an estimated 10.4 million new cases of TB and 1.4 million TB deaths with more than 250,000 of them caused by drug-resistant infections.
This piece was produced by SciDev.Net’s Asia & Pacific desk.