Assuming you rinse them off and you have a reasonably large amount of cutlery, I'd say you are definitely too paranoid about this specific thing. Your entire kitchen is a bacterial growth medium - just leaving things out means they get covered in bacteria. Those bacteria will grow and this is fine - the most efficient use of your thoughts is fixing the really large offenders, one of which is: Do you properly wash your hands (most people do not, or at all)?