They can get really hard to beat. Once they hit you once you are screwed they will hit you with the spinning attack they will do until until you die you won't be able to do anything.
KEEP YOUR DISTANCE and use the Bees and Explosive ammo.
Jump to evade the green goo they throw because if they get you you will get stuck and hide behind the bookcases as much as possible.
If you manage to drain them a lot of health SAVE. You can save anytime you want in this game.
Lots of achievements are broken in this game so anyway it's a good idea to have a save before you beat them in case.