How potent bacterial toxin kills MRSA superbug found

Scientists have discovered how a potent bacterial toxin is able to target and kill MRSA bacteria, paving the way for potential new treatments against antibiotic-resistant superbugs.

MRSA is a bacterial superbug that is resistant to several antibiotics and frequently spreads in hospitals where people are more susceptible to infection. New research, published in the journal Nature Chemical Biology, explained how a bacterial toxin, lysostaphin, specifically recognises MRSA cell walls and quickly causes the breakdown of this pathogen. The lysostaphin is able to increase the number of its molecules bound to the surface of the MRSA cell and this allows the enzyme to 'walk' along the cell walls and cause rapid breakdown.

Lysostaphin is an enzyme that has been shown to eradicate Staphylococcal infections, such as MRSA, alone or in combination with antibiotics. Although the enzyme was discovered over 50 years ago, not much has been known about how it kills these infections, the researchers said. The scientists hope to use their findings to develop new treatments for MRSA and other antibiotic resistant superbugs which target the infection in a similar way.

"Lysostaphin is arguably the most studied enzyme after lysozyme, so we are delighted that our research is able to explain the mechanism underpinning its potent antibacterial activity," said Stephane Mesnage, Senior Lecturer at the University of Sheffield. "Our study explains how this enzyme is able to target and digest the MRSA bacteria and why it is so potent. "Hospital-acquired infections caused by bacteria resistant to last resort antibiotics are on the rise, but our work could lead to the development of new treatments for these superbugs that use the same targeting mechanism," Mesnage said.