The bacteria cannot make type III antigen. The bacteria are mutants that still make type-III molecules, but they lack the ability to attach them to a polysaccharide capsule. Bacterial sex is important. Different mechanism from us. But also the same general principles apply.
Bacteria have mutations.
Why bacteria are useful as genetic organisms. Phage and bacterial sexual processes. F-factors are new. Lots of this repeats high school biology. Complementation and recombination.