Bacteria that cause cholera and bubonic plague turn from harmless to deadly with the flip of a genetic switch. Jam the switch and you might prevent infection, said Vladimir Svetlov, a microbiology research associate at Ohio State University and one of a group of scientists who defined the structure of a protein that appears to be the key. The discovery is one of many this year to identify structures and chemicals crucial to disease. All of this work could lead to new medicines.

At the same time, germs we once fought off with antibiotics are fighting back, forcing governments and health organizations worldwide to spend billions of dollars to find new remedies.
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Redinbo is part of a team that recently discovered that two osteoporosis drugs block a key site on E. coli bacteria, preventing it from passing antibiotic resistance genes to other E. coli.

By their nature, bacteria exchange pieces of their DNA with neighboring bacteria, leading to new forms that are virulent or resistant — or both. “This is not minor evolution,” said Irina Artsimovitch, associate professor of microbiology at Ohio State. “This is a huge genome exchange.”