Researchers Map Signaling Molecules that Bacteria Use to Communicate

Researchers at the University of Copenhagen have mapped how Staphylococcus bacteria communicate using signaling molecules. This communication helps bacteria coordinate actions, such as infecting a wound. However, other bacterial species can interfere with these signals, weakening their ability to act in unison.

The study, published in mBio, focused particularly on Staphylococcus aureus, a species that includes methicillin-resistant strains (MRSA), which are known for being difficult to treat with antibiotics. Using their findings, the researchers identified a signaling molecule from another Staphylococcus species, Staphylococcus simulans, that weakened MRSA communication.

“With our mapping, we can identify which signaling molecules are most effective against MRSA. We found that a signal from another Staphylococcus variant, Staphylococcus simulans, was very potent against S. aureus. Originally, the signaling molecule was isolated from a bacterial strain from a cow, but it is also present on goats, horses and humans,” says Christian Adam Olsen, one of the authors of the new study.

Tests in mice showed that the S. simulans signal worked effectively to prevent MRSA skin infections. “With a single dose of this signaling molecule, the mice could overcome an MRSA skin infection just as effectively as mice treated daily with an antibiotic ointment,” explained co-author Benjamin Svejdal Sereika-Bejder.

The researchers also examined whether MRSA would develop resistance to the signaling molecule, as often happens with antibiotics. “We observed that under laboratory conditions, the bacteria did not develop resistance even after 15 days,” said Sereika-Bejder. Unlike antibiotics, the signaling molecule does not kill the bacteria but disrupts their ability to coordinate hostile actions. 

According to Professor Olsen, “There is no evolutionary pressure on the bacteria to develop resistance, as they do not perceive the signaling molecules as being lethal.” This approach offers a potential alternative to traditional antibiotics by allowing bacteria to live but making it harder for them to cause disease.