Well, although I think the Singleton
pattern is overused, that's really what you're asking for here. If there's ever only supposed to be one JobsDB, then make it a static member of its own class, and put a static method in the JobsDB class which retrieves that one object. Now, you said another class creates that one instance, but perhaps you could let the JobsDB class create it itself?
Now any class that wants to get ahold of that one JobsDB instance just has to call "JobsDB.get()" to get it. JobsDB is a "Singleton class."