Superbug's resistance secret is discovered

A SUPERBUG'S resistance secret has been uncovered by scientists, paving the way for new drugs to fight infections.

For the first time, researchers have discovered how a key protein helps MRSA (methicillin resistant Staphylococcus aureus) bacteria to evade antibiotics.

The bug is particularly problematic in hospitals where patients with open wounds and weakened immune systems are at greater risk of infection than the general public.

The protein, discovered by American researchers and known as "Cfr", acts on the ribosome, a molecular "factory" in cells responsible for making proteins that are vital for survival.

Many antibiotics bind on the ribosome in bacteria and stop it functioning, causing the bugs to die. Through a chemical process called "methylation", Cfr blocks the binding of antibiotics to the ribosome. At the same time it helps to keep the machinery working. In the case of MRSA, the introduction of Cfr makes the superbug resistant to seven classes of antibiotics.

Scientists found that it passed from Staphylococcus sciuri, which normally only infects animals, to the human bug Staphylococcus aureus - which commonly lives in the nose and on the skin without causing harm, but can be highly dangerous when it mutates into its resistant cousin MRSA.

The new research has been published in the journal Science. Lead scientist Dr Squire Booker, from Pennsylvania State University in the United States, said: "We now have a very clear chemical picture of a very clever mechanism for antibiotic resistance that some bacteria have evolved. Because we know the specific mechanism by which bacterial cells evade several classes of antibiotics, we can begin to think about how to disrupt the process so that standard antibiotics can do their jobs."