Does dairy (e.g. crème fraîche) spoil faster if using the same spoon in older and newer product? If I'm using up the last of one package of crème fraîche and then starting on a newer package (later "best by" date), I avoid using the same spoon because of a theory that the newer package will get spoilt quicker.

Does anyone know if there is any sense in this?
Food in general spoils when bacteria, fungus, and other little bugs eat the food, multiply into more, create waste, and then die. I would imagine that the increased population of "bugs" found on a old, used, not washed spoon would cause the decomposition of new creme fraiche to accelerate, but if you wash the spoon, then no-problem.