New antimicrobial destroys E. coli in 30 seconds

The increase in drug-resistant bacteria and concerns raised over triclosan have highlighted an urgent need for new antimicrobial materials.

Triclosan, a common ingredient found in many products such as toothpastes, soaps and detergents to reduce or prevent bacterial infections, has been linked to making bacteria resistant to antibiotics and adverse health effects. The European Union has restricted the use of triclosan in cosmetics and the US Food and Drug Administration is conducting an ongoing review of this ingredient.

Driven to find a suitable alternative, scientists in Singapore have synthesised a chemical compound, made up of molecules linked together in a chain, which can kill 99.7% of E. coli bacteria within 30 seconds. Its chain-like structure helps it to penetrate the cell membrane and destroy the bacteria. In contrast, antibiotics only kill the bacteria without destroying the cell membrane. Leaving the cell structure intact allows new antibiotic-resistant bacteria to grow.

Known as imidazolium oligomers, the material comes in the form of a white powder that is soluble in water. The researchers at the Institute of Bioengineering and Nanotechnology (IBN) of A*STAR found that once this was dissolved in alcohol, it formed gels spontaneously. This material could be incorporated in alcoholic sprays that are used for sterilisation in hospitals or homes.

The material was also tested against other common strains of antibiotic-resistant bacteria and fungi, such as Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans, and was able to kill 99.9% of these microbes within two minutes.

The findings have been published in the peer-reviewed journal Small.