Tb mycobacteria finding hailed

Greg Cook.
Greg Cook.
University of Otago microbiologists have made an ''amazing discovery'' that offers new hope for developing revolutionary new antibiotics to attack tuberculosis.

Recent World Health Organisation figures show 1.3 million people died from Tb throughout the world in 2012.

Prof Greg Cook, of the Otago microbiology and immunology department, led the research team which has identified a ''highly promising'' new target for anti-Tb drug therapy, in research published in the United States journal PNAS today.

The Otago researchers helped unravel the mystery of why mycobacteria - a family which includes the microbe that causes Tb - are such extraordinarily hardy organisms.

Helped by fellow researchers in the US and Germany, the Otago scientists have clarified the mechanisms by which the aerobic soil microbe Mycobacterium smegmatis can long persist without, or almost without, oxygen.

Hydrogen was a key factor that enabled mycobacteria to survive oxygen limitation for long periods, they found.

Prof Cook said it had long been puzzling how mycobacteria generated energy while in oxygen-starved dormant states, such as, when in people with latent Tb infections, Mycobacterium tuberculosis bacteria were ''walled in by clumps of immune and other body cells''.

But such patients had to be monitored for the rest of their lives because the bacteria became active again.

Enzymes that enabled bacteria to produce hydrogen, and to generate energy from it, could become an ''excellent next-generation drug target'' in latent Tb infections, which affected about one-third of the world's population, he said.

One of the paper's lead authors is Dr Michael Berney, a former research fellow in Prof Cook's laboratory.

Other co-authors included Prof Cook and Dr Chris Greening, who also co-led the study and recently completed his PhD studies at the same laboratory.