Well, there's the Dornier Do-24. Turbine AND multi engine. It's on a German registry, so someone somewhere must be able to sign not only off a MES rating, but a turbine type rating for an aircraft that no else could possibly be certified for. There are no ATO's for these one-off's. Yet, it flies.
And of course there is a MES rating in EASA-land, they just call it MEP (Sea). It's just that it can't be issued by anyone because they're bureaucrats.