A. The source you are citing is an American Journal, and the author of this piece specifically points out that American Medical Authorities do not accept this thesis.
You've got a lot to learn about the way scientific papers are published. If you go to
PubMed and look using "Crohn's" disease and "Mycobacterium paratuberculosis," you'll see that people have been researching this for a long time, with quite varied results. These results are indicative of what I said in my post above: there is a lot more going on in this disease than something so simplistic as a "germ." Read through the abstract posted above. This time actually read it instead of dismissing it as an "American Journal". Note that the disease itself makes the intestinal tissue much more susceptible to bacterial infection. The "link" the article at the top of this threat touts is more than likely to be a consequence of the disease rather than its cause.