Avoiding bacterial "friendly fire"

Antibiotic-producing bacteria have evolved a range of mechanisms to escape the lethal effects of their own chemical warfare, including antibiotic elimination through specific efflux pumps, antibiotic inactivation by modification of its chemical structure, modification of the antimicrobial target, and antibiotic sequestration. It has been suggested that self-protecting mechanisms have contributed to the widespread resistance of pathogenic bacteria to clinically important antibiotics. In the September 12 Science, John Biggins and colleagues at the University of Wisconsin–Madison describe a novel method by which some bacteria resist the potent toxins they produce and shed light on how bacteria might develop resistance to pharmaceutical antibiotics (Science, 301:1537-1541, September 12, 2003).

Biggins et al. studied the poorly known mechanism of resistance to enediynes, a set of antibiotics that are among the most potent cytotoxic antitumoral agents to have been discovered in the past decade. These highly reactive substances destroy bacteria by generating a reactive diradical ...