Sublethal force: New antibiotic aims to tame bacterial toxins

Using an innovative screening approach, researchers in the lab of John Mekalanos have identified an entirely new class of antibiotics active against the cholera bacterium. While traditional antibiotics kill bacteria outright by interfering with processes essential for their survival, the new agents block production of bacterial proteins that promote infection and cause cholera symptoms. Tests in animals proved that the new compounds could prevent bacterial colonization.

The work opens up a new world of potential for antibacterial drugs that aim to block the unique disease-causing talents of cholera bacteria, which include the production of cholera toxin. “What we’ve done is made a custom, organism-specific antibiotic against Vibrio cholerae,” said Mekalanos, the Adele Lehman professor of microbiology and molecular genetics and head of that department. Since most bacteria that cause human disease elaborate virulence factors such as toxins, Mekalanos said, “There is no reason our approach can’t be replicated for a number of other important pathogens.” The research appeared Oct. 13, 2005 in the online edition of Science.