Researchers have discovered a viral protein that acts as an antibiotic against E. coli. The new finding, announced today in the journal Science, opens up a novel approach to designing drugs to fight other bacteria, such as those that cause pneumonia, ear infections, cholera and Lyme disease.

Thomas G. Bernhardt of Texas A&M University and his colleagues found the protein in a tiny virus, or phage, known as Q Beta. Scientists had long wondered how Q Beta and other small phages eliminate bacteria. The new research shows that Q Beta's killer accomplishes this feat in much the same way that antibiotics do, by preventing the bacterial cell from making its outer cell wall. Thus, instead of dividing and multiplying, the cells commit suicide.

In theory, pharmaceutical companies could mimic protein antibiotics such as the one housed in Q Beta, team member Douglas K. Struck points out. Drugs based on these proteins could be made to target multiple bacteria or single pathogens. "As bacteria's natural enemies, their potential as sources for ways to kill bacteria should have been thoroughly explored long ago, but it is only now, with the emerging worldwide crisis in antibiotic resistance, that phages are finally getting attention in their own right," Ing-Nang Wang, another co-author on the report, remarks. "It looks like small phages are a gold mine for protein antibiotics."