How a harmful bacterium senses iron—and why it matters for fighting infections

Pseudomonas aeruginosa is a common culprit in hospital-acquired bacterial infections and is growing more resistant to antibiotics. New findings from Aaron Smith, professor of chemistry and biochemistry at UMBC, and collaborators at Oklahoma State University show how a two-protein system inside the bacterium operates like a sensitive switch: The pair detects iron both outside and inside the cell and then rewrites large parts of the microbe's metabolism in response.