What could happen if the wrong organism is identified as the cause of disease?

OF COURSE THE WRONG MEDICATION WILL BE PROVIDE MYAN

If the wrong organism is identified, then people would probably be in danger. Because you wouldn't know if the actual species is deadly or not. Lets say that the wrongly identified organism isn't deadly, but the real one is. Everyone  is just strolling along, and then you're dead because it bit you.

And of course, if you're coming up with a cure, (because both are toxic) you're making the wrong one. Which could harm people just based off their bodies and what you're putting into them.  Everyone is different.