Frog Skin Oozes Possibly Powerful Antibiotic

Amphibians secrete new weapon for drug arsenal

31 August 2010

The skin of certain frogs, including this foothill yellow-legged frog, contains secretions that may lead to new antibiotics to fight infections that shrug off the effects of existing antibiotics.

The emerging battle against drug-resistant bacteria poses a huge threat to public health worldwide. That threat has loomed larger as the number of effective antibiotic drugs has dwindled.

J. Michael Conlon, a biochemist at the United Arab Emirates University, says frog skin, which protects the amphibians from injury and disease, is coming to the rescue by providing a wealth of new antibiotic compounds to fight drug resistant fungi and bacteria.

"Frogs of necessity have to live in a warm moist environment that is very conducive to the growth of micro-organisms. They've been around for a long, long time, at least 300 million years" says Conlon. "So, it's not so surprising that, over the course of evolution, they have developed defenses against these invading pathogens."

Conlon has identified germ-fighting chemicals from more than 200 frog species from around the world by isolating peptides or strings of proteins that have the ability to kill bacteria and fungi.

He says the challenge is to get those agents to work in humans. "The problem is that as well as efficiently killing micro-organisms, they are to various degrees toxic to mammalian cells. So it's not a great idea to cure infection if you kill the patient at the same time."