A team of researchers led by Dr Angelika Gründling from Imperial College London has discovered 4 proteins that act as receptors for an essential signalling molecule in bacteria such as the methicillin-resistant Staphylococcus aureus (MRSA).This micrograph shows methicillin-resistant Staphylococcus aureus (Janice Haney Carr / CDC / Jeff Hageman / M.H.S.) A recently discovered molecule called cyclic diadenylate monophosphate (c-di-AMP for short) appears to play a vital role as a messenger in many bacteria, carrying signals between parts of the cell. There is evidence that strains with more c-di-AMP are more resistant to antibiotics.But until now, very little was known about...