A new antibiotic with "a unique approach" to attacking and killing bacteria has been discovered by scientists.
Researchers in Canada believe the newly found corbomycin could be a "promising clinical candidate" in the quest to tackle the growing issue of microbes becoming resistant to antibiotics.
According to the World Health Organisation, antibiotic resistance is one of the biggest threats to global health, with an estimated 700,000 deaths worldwide every year.
Corbomycin, along with a lesser-known antibiotic known as complestatin, have been found to kill bacteria by blocking the function of their cell wall, a phenomenon scientists have observed for the first time.
Beth Culp, a PhD candidate in biochemistry and biomedical sciences at McMaster University in Hamilton, Ontario, said: "Bacteria have a wall around the outside of their cells that gives them shape and is a source of strength.
"Antibiotics like penicillin kill bacteria by preventing building of the wall, but the antibiotics that we found actually work by doing the opposite - they prevent the wall from being broken down. This is critical for cells to divide.
"In order for a cell to grow, it has to divide and expand.
"If you completely block the breakdown of the wall, it is like it is trapped in a prison, and can't expand or grow."
Both corbomycin and complestatin come from a family of antibiotics called glycopeptides that are produced by soil bacteria. Tests on mice showed these antibiotics can block infections caused by Staphylococcus aureus, a group of drug-resistant bacteria that can cause serious infections such as blood poisoning and toxic shock syndrome.
The researchers used a cell imaging technique to make their discovery.
Ms Culp said: "This approach can be applied to other antibiotics and help us discover new ones with different mechanisms of action. We found one completely new antibiotic in this study but, since then, we've found a few others in the same family that have this same new mechanism."
Brendan Wren, professor of microbial pathogenesis at the London School of Hygiene & Tropical Medicine - who was not involved in the study, said: "The study is a promising approach to discovering new antibiotics against MRSA and possibly other bacteria. But as this new group of antibiotics have only been tested in mice, there is still a long way to go before this could be a product as there will be considerations of costs and testing for toxicity and efficacy in humans."
The findings are published in the journal 'Nature'.