A solution in the soil

Jenny Chalmers 25 January 2015

Antibiotics are chemical compounds which either kill bacteria, or stop them from reproducing. More than 150 have been developed to treat bacterial infections, and they are estimated to have saved millions of lives since the discovery of penicillin in 1928. However, many bacteria are now becoming resistant to antibiotics, making these ‘miracle’ drugs useless against several deadly diseases. 

Bacteria can evolve resistance to antibiotics in several ways, through adapting the cellular process targeted by the antibiotic, or by pumping the antibiotic molecule out of their cell. Unnecessary prescription of antibiotics, pre-emptive administration in livestock to prevent disease (now banned in Europe since 2006) and not finishing a full course of antibiotics have all contributed to the rise in antibiotic resistance. Over-use of antibiotics applies a strong selective pressure for bacteria to evolve resistance.

The Health Protection Agency say they are “seeing an increasing number of resistant strains year on year,” with some of the deadliest pathogens becoming resistant to multiple antibiotics, such as extensively drugresistant tuberculosis, and a few strains resistant to all antibiotics. In the UK, 2500 patients die each year from blood poisoning by antibioticresistant superbugs. England’s chief medical officer, Professor Dame Sally Davies, has described this situation as an “apocalypse.”

Resistance to current antibiotics is not a problem if new antibiotics are constantly introduced. However, no novel classes of antibiotics have made it since the Lipopeptides were discovered in 1987. In addition to increased costs of development, only four pharmaceutical companies are now actively researching antibiotics. There is, however, some hope. Several programmes have recently been launched to encourage research into antibiotics, for example the European IMI has provided £190 million for research into antibiotics.

In January 2015, scientists at Boston’s Northeastern University reported a novel approach for discovering antibiotics. Many bacteria secrete their own antibiotics to fend off competition from other bacteria. Professor Kim Lewis and his team believe they can grow nearly 50% by exposing the bacteria to soil. 25 new antibiotic compounds have already been discovered with this method, and 1 of these – Teixobactin – has already been shown to be non-toxic to mammalian tissues and able to clear deadly doses of MRSA in mice.

Although the new discoveries are promising, they only delay the problem of an antibiotic “apocalypse.” Antibiotic prescriptions in England are still rising, and it is now the right time for educating about the intelligent use of antibiotics .