My students and I study Salmonella bacteria, as well as some of the viruses that infect these organisms. Most of this research deals with a molecule produced by Salmonella called lipopolysaccharide, which forms a barrier on its external surfaces, thereby rendering them more resistant to various chemicals and other entities that might otherwise harm them. In the past, I have studied how certain viruses use enzyme activity to burrow their way through the lipopolysaccharide barrier so that they can infect the Salmonella bacteria. More recently, our efforts have been focused on understanding how some of these same "burrowing" viruses are also able to achieve a condition known as cell surface conversion. A cell surface converting virus is one that, upon successfully infecting a bacterium, immediately sets about producing enzymes that cause the structure of the surface lipopolysaccharide of the bacterium to be modified. Such lipopolysaccharide structural changes make it impossible for the bacterium to be infected by other viruses of the same type (i.e. "the early virus gets the bacterium!", which sounds a little bit like words of advice many of us remember receiving from our parents!)