MOSCOW, Dec. 12 (UPI) -- An old Russian way of keeping milk from going sour by putting a frog in the bucket of milk has led to the finding of new antibiotic substances, scientists say.

Organic chemist A.T. Lebedev of Moscow State University and colleagues have identified a number of potential new antibiotic compounds in the skin of the Russian Brown frog, a study published in the American Chemical Society's Journal of Proteome Research reported.


Amphibians secrete antimicrobial substances called peptides through their skin, the researchers said, as a first line of defense against bacteria and other microorganisms that thrive in the wet places frogs, toads, salamanders and other amphibians live.

A previous study identified 21 substances with antibiotic and other potential medical activity in the frogs' skin, and Lebedev and his colleagues say by using sensitive laboratory techniques they've discovered 76 additional compounds.

In lab tests, they said, some of the substances performed as well against salmonella and staphylococcus bacteria as some prescription antibiotic medicines.

"These peptides could be potentially useful for the prevention of both pathogenic and antibiotic resistant bacterial strains while their action may also explain the traditional experience of rural populations," the researchers wrote.