Don't worry, gram-positive bacteria are very quickly innovating the amino acid chains in their peptidoglycan structure, thus thwarting any attempts we have at manipulating nature. Essentially we're fucked. In the meantime, what they are doing is really cool. This isn't completely off topic. The point is that we can learn to give ourselves a fighting chance, but mutation is just too rapid for us to ever get past. It's an arms race, and we are north korea.