McMaster researchers find 'great leads' for new antibiotics

A group of researchers at McMaster University are addressing the issue of drug resistance by taking the road less travelled to come up with new approach to find antibiotics.

Instead of looking for new antibiotics under conventional nutrient-rich conditions in the laboratory, the McMaster team developed technology to find antibacterial compounds under nutrient-poor conditions.

Nutrient-limited conditions are more akin to the environment that bacteria face in the human body during an infection, according to Eric Brown, lead author of the research paper and a biochemistry professor at McMaster.

Convention says you try to kill bacteria under the richest growth condition that you can create in the laboratory, Brown told CBC Hamilton. And yet we know that life is not that kind to bacteria when they are infecting the human body. They actually struggle quite a bit.

The paper is published in the online edition of Nature Chemical Biology on Sunday.

The team created a growth environment that lacks vitamins and amino acids to force the bacteria to synthesize their own building blocks.

'Arms race' with bacteria

The next step was like looking for a needle in a haystack, said Brown, as his team tried to find chemical compounds that block the ability of bacteria to make these nutrients.

The researchers sifted through 30,000 chemical compounds a process aided by a robotic liquid handling technology at McMaster.

The researchers discarded chemicals that blocked bacterial growth in conventional nutrient-rich conditions and focused specifically on those that were only active in nutrient-poor conditions. They narrowed the fielddown to 71 such chemicals and investigated three of them.

The team's discovery has the potential to address the issue of antibiotic drug resistance, Brown said.

Mutation and exchange of genetic materials among bacteria can lead to highly resistant strains, he said. So it's a bit of an arms race.

The next stage for the researchers is to investigate whetherthe discovered compounds can be turned into new antibiotics.

"Drug discovery and development is a long road, but we think these three are great leads for a new kind of antibiotic," he told CBC Hamilton.