Every potent antibiotic—doxycycline, rifampin, levofloxacin—recognizes some molecular component of human cells that is different from a bacterial cell. In this sense, every antibiotic is a “cellular medicine”—a drug that relies on the distinctions between a microbial cell and a human cell. The more we learn about cell biology, the subtler distinctions we uncover, and the more potent antimicrobials we can learn to create.
