I've heard of this "problem"..
In a lot, of, European designed dishwashers. Esp, Miele & Bosch Models...
It would seem from my opinion to be from, egg residue, and the like, that the detergent isn't able to dissolve or kill off the protein, or carbohydrate from the soil.
Now, most detergents, contain, "Enzymes" which, generally do a good enough job, and are able to dissolve and keep this under control. But.. there are problems. Sometimes, the enzymes can't act fast enough, and Food residue (I think Egg, but it could be anything) gets stuck on dishwasher components. I think this is really problematic, on Dishwasher filter based machines, or dishwashers without built in Food disposers.
There are ways, to fix the problem. One is to use a Chlorine Laden Detergent, such as Finish or Cascade Gel. The Chlorine Content will off the protein content in food, and take away that awful smell. However, if your one to generally have, stuck on food, and tough to scrub dirty dishes, you may start to notice some things (not all) but some things may not come out as clean as well, or, you may have to use a longer cycle time than before..
Another idea is, to use a High-Enzyme content, detergent, such as Cascade Complete, or Finish Quantum or Powerball. The Tablets from Finish, and the Gel Packets, from Cascade, both contain enough enzyme content to dissolve through tough food, but they have the addition of Oxygen Bleach, to help control this problem, and help with Coffee & Tea stains.
Thing is, the Oxygen Bleach can only do so much, and I don't think it'll take care of that smell. It'll just help to prevent it from coming back.
I'd run a Dishwasher Cleaner, or Citric Acid Crystal (lemishine) cycle, to help clean it out. Although, the use of a Chlorinated Detergent, would definitely help.