Raiding the Ocean's Medicine Cabinet

Antibiotics are losing their effectiveness against disease. But the world’s waters could be full of new drugs, just waiting to be discovered.

- Helen Scales

Mud and sponges probably don’t feature highly on most scuba divers’ bucket lists. But scientist and explorer Brian Murphy, based at the University of Illinois at Chicago, has his sights set on the sediments lurking at the bottom of lakes and the gooey animals clinging to submerged shipwrecks. And for good reason. He recently brought back a blob of mud from Lake Michigan and found it contained bacteria that make two previously unknown molecules. Lab tests showed that this class of compounds is lethal to the bacterium that causes tuberculosis, a disease that existing drugs are struggling with. “For millions of years bacteria have fought one another,” says Murphy. “We’re just harnessing that power.”

Around the world, super bugs are on the rise. Earlier this year, two patients in the US were discovered with strains of E. coli that’s resistant to many antibiotics, including drugs that doctors only use as a last resort. It’s an alarming trend in which bacteria are gaining the upper hand in their battle against the antibiotics we use to kill them, hastened by the world’s overuse of these drugs.

“The way to combat drug resistance is to find new chemistry,” says Murphy. He’s one of many modern-day prospectors who are searching for that new chemistry underwater.

PLUMBING THE DEPTHS

From icy polar seas to scorching hydro thermal vents, and from coral reefs to inland lakes, the vast, aquatic realms covering seventenths of our planet are home to an immense diversity of life. They include many animals that evolved complex chemical defences, along with a profusion of microbes; it is thought that around 90 per cent of oceanic life is microscopic. From among these creatures, researchers are uncovering molecules that could form the basis for new medicines.