Emory researcher David Weiss has spent years studying a baffling phenomenon called heteroresistance, in which a tiny fraction of bacteria remain resistant to antibiotics, while the remainder succumb. Recently, he brought his scientific acumen to the equally deadly threat of fungal bloodstream infections in patients receiving bone marrow transplants. Bloodstream infections can be lethal in these patients, including infections from Candida parapsilosis, a species of fungi that can live in the d...