A drug under clinical trials to treat tuberculosis could be the basis for a class of broad-spectrum drugs that act against various bacteria, fungal infections and parasites, yet evade resistance, according to a study. The team determined the different ways the drug SQ109 attacks the tuberculosis bacterium, how the drug can be tweaked to target other pathogens from yeast to malaria -- and how targeting multiple pathways reduces the probability of pathogens becoming resistant.