Serratia in dishwasher

I have been battling this for a few years. I will do a deep clean, which takes many hours, but of course I can’t get at all the areas where this stuff is growing, and it just comes back. Is it worth it to hire a repair person to take the thing apart to try to eradicate it, or do I just replace the dishwashe — and if the latter, will the existing pipes just spread it to a new dishwasher?

I think the source of the serratia was that my last dog was colonized with it — it grew in the water bowl if not cleaned frequently. Doesn’t seem to be an issue with our current dog.