Diseases such as tuberculosis, anthrax, and shigellosis -- a severe food-borne illness -- eventually could be treated with an entirely new and more-effective kind of antibiotic, thanks to a team of scientists led by Kenneth Keiler, an associate professor of biochemistry and molecular biology at Penn State University. The team describes 46 previously untested molecules that target and disrupt an important step in the process of protein synthesis in bacteria, thereby rendering bacteria incapable of replicating. In this image, Bacillus anthracis (anthrax) cells are being killed by one of these molecules. The molecule is naturally fluorescent, and it looks blue when it is excited by ultraviolet light in the microscope. Keiler and his team found that certain molecules inhibit the growth of very distantly related bacteria by stopping trans-translation, which is a "quality control" mechanism that is found in all species of bacteria.