Researchers have found that the ancient RND-type multidrug efflux pump AcrB from Haemophilus influenzae targets the same drugs as its more evolved counterpart from Escherichia coli, showing that multidrug resistance is an ancient trait. The more ancient protein is unaffected by efflux pump inhibitors, which were designed to target the evolved pumps. Understanding these evolutionary differences will help researchers develop targeted therapies against multidrug-resistant bacterial pathogens.
