Scientists may have found first new antibiotic in 25 years
Scientists today hailed a potentially major advance against antibiotic resistance with the development of what could be the first new class of antibiotics in 25 years.
If approved for use in humans the new compound, called teixobactin, promises to combat pathogens that have already gained resistance to all available treatments.
Equally importantly, the novel method by which teixobactin was discovered also opens up a whole new mechanism by which scientists can hunt for other antibiotics.
The discovery, outlined in the journal Nature, comes after David Cameron warned that the world could be “cast back into the dark ages of medicine” unless we started taking action to combat growing resistance to antibiotics.
Teixobactin is not, however, able to kill some common strains of bacteria such as E. coli. But experiments on mice showed it could be able to tackle other pathogens such as MRSA and tuberculosis that have proven increasingly difficult to destroy through conventional means.
Professor Kim Lewis, from Northeastern University, said the research “started with the problem we are all pondering – that pathogens are acquiring resistance faster than we can introduce new antibiotics. It is causing a human health crisis. Now we have pathogens that are resistant to all available antibiotics”.
His laboratory is one of many around the world trying to develop new antibiotics to solve this. In autumn last year scientists at MIT announced promising results from an approach that involved engineering compounds to attack the precise genes in the target pathogens.
Professor Lewis in some ways took a more conventional approach by recognising that, until now, many of the potential antibiotics produced by nature have been unavailable to science.
“Most antibiotics we currently have, have been isolated from soil microorganisms. Only about 1 per cent of environmental microorganisms will grow on petri dishes in the lab.” He and his colleagues created a method for growing the other 99 per cent, by sandwiching them between permeable membranes that are then buried in the soil.
“We figured they do grow in soil, so that’s where we are going to grow them. We’re tricking the bacteria; they don’t know this is happening to them. They start growing and form colonies. Once that happens they become domesticated, and can grow on a petri dish.”
Using this technique his laboratory analysed 10,000 cultures. Among them 25 other new antibiotics were found, but teixobactin was deemed the most promising.
Scientists are particularly excited by the fact that teixobactin acts on a fundamental part of the bacteria. This means that it will be far harder for those bacteria to mutate and become resistant to it, as has happened with other antibiotics.
Between 1940 and 1960 a steady stream of new antibiotics were discovered and developed into drugs, revolutionising medicine. Since then developments have dried up and it has been a quarter of a century since any significant new antibiotics entered the market. This method means that it could be possible to isolate many other antibiotics in this way.
“The discovery suggests this is a promising source in general for antibiotics, and has a good chance of helping revive the field of antibiotic discovery,” said Professor Lewis. He estimated the compound is two years from clinical trials and, if successful, at least five years from production.
Other scientists welcomed the news. Professor Mark Woolhouse, from the University of Edinburgh, said: “Any report of a new antibiotic is auspicious, but what most excites me is the tantalising prospect that this discovery is just the tip of the iceberg. Most antibiotics are natural products derived from microbes in the soil. The ones we have discovered so far come from a tiny subset of the rich diversity of microbes that live there.
“It may be that we will find more, perhaps many more, antibiotics using these latest techniques. We should certainly be trying – the antibiotic pipeline has been drying up for many years now; we need to open it up again, and develop alternatives to antibiotics at the same time, if we are to avert a public health disaster.”
http://www.thetimes.co.uk/tto/health/article4316698.ece
