An international research team reports that the saliva of a Siberian brown bear (Ursus arctos collaris) subspecies can kill Staphylococcus aureus bacteria, a strain that is rapidly becoming resistant to all current antibiotics.

Image credits Oksanna Briere.

One subspecies of the Siberian brown bear can kill S.aureus with its bare saliva, a new paper reports. The animal’s range includes Mongolia, Siberia, and parts of northern China. While generally vegetarian, the bears also dine on caribou, elk, and fish. This wide menu has a profound impact on the subspecies’ microbiome, the team writes — including its surprising disinfectant ability.

‘Drool over this, please’

The discovery comes as part of a larger project aiming to study the microbiome of several wild animals. The project’s goal is to find naturally-occurring chemicals which can kill bacteria that also infect humans, especially the strains that are becoming or have become resistant to antibiotic treatments.

The team captured several specimens of the bear subspecies in the taiga — the forested parts of Siberia — and harvested saliva swabs for analysis. Using “state of the art screening techniques,” the team was able to identify the chemical make-up and microbiota of the samples.

One bacteria swimming its merry way in that saliva is Bacillus pumilus, a strain that secretes an antibiotic compound known as amicoumacin A. The team believes the bears obtain this bacterium when they munch on certain types of vegetation.

After finding B.pumilus in the saliva samples, the team looked to see how it interacts with other antibiotic-resistant bacteria such as S.aureus — which is associated with skin infections in humans. That’s how they discovered that the strain can effectively deal with the staphylococcus.

The findings could go a long way in hospitals and other healthcare facilities, which are struggling to remove the deadly bacteria. A naturally-occurring chemical that can help us fight staph would be quite valuable.

The team plans to continue the project in hopes of finding even more new compounds that can help us keep bacteria at bay.

The paper “Ultrahigh-throughput functional profiling of microbiota communities” has been published in the journal PNAS.