Tiny levels of nicotine kill the tuberculosis bacterium, researchers in Florida have discovered. They say it might be possible to use nicotine to treat the growing problem of drug-resistant forms of TB.
鈥淭he amount of nicotine needed to kill the bacteria is less than in one cigarette,鈥� says Saleh Naser of the University of Central Florida, who presented his results at a meeting of the American Society for Microbiology in Orlando on Monday.
鈥淏ut we are not saying smoke and get lung cancer,鈥� he emphasises. Rather, he hopes that nicotine pills or sprays could be developed if further studies show that nicotine works on people.
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Other researchers are sceptical. 鈥淟ots of patients smoke and still get the disease,鈥� says Salman Siddici of the company Bectin Dickinson, who has worked on TB. 鈥淢any drugs inhibit growth in the lab but don鈥檛 work in vivo.鈥�
Chance discovery
Naser made the discovery by chance. A colleague of his inserted a gene for a protein into tobacco plants, to see if it would kill the TB bacterium. But when Naser tested the antibactericidal properties of these plants, he found normal tobacco was just as effective at killing cells. Further studies showed nicotine was responsible for the effect.
Naser and his colleague George Ghobrial found that as little as 0.27 micrograms of nicotine per millilitre was enough to kill Mycobacterium tuberculosis. It was also effective against other strains of Mycobacteria.
Naser says that smoking doesn鈥檛 work because the level of nicotine fluctuates so much. 鈥淭he dosage is wrong,鈥� he says.
The advantage of nicotine, Naser claims, is that it should work against antibiotic-resistant bacteria. However, he doesn鈥檛 yet understand how it destroys bacterial cells. His team now plans to test nicotine on TB bacteria growing in tissue cultures.
