Do antibiotics target more quickly dividing cells as well?
One of the classic antibiotics, penicillin, actually only attacks growing cells because it attacks the mechanism whereby the cell wall gets bigger. It’s called a penicillin-binding protein and in fact it’s building a new cell wall. If the cell is just quiet then the penicillin has no effect at all. So non-growing cells are totally resistant to penicillin. Not all antibiotics work that way but that particular one works that way. [In biofilms,] the cells on the outside are used to growing a bit faster. They are used to nutrients if they aerobic, they see more oxygen. Can you discuss the stages of a biofilm from start to finish in terms of genes being turned on and off? The very first thing that the bacteria have to do is come along as planktonic cells. They have to make a decision to stay on the surface. Otherwise they are popping on and off all the time. So when they irreversibly adhere, then they start a process where they start to turn a bunch of genes on and that’s within 15 minutes
