Everyone on this forum has been real helpful and I just want to thank you all!!!

I have a question about make-up brushes and it may sound silly. Do you clean your brushes? With what (if you do)? And how often? I find that I start to break out and I wonder if its from bacteria on my brushes. Example my checks will get black heads where I apply my blush. Has anyone had this problem? I always wash my face before I appy any make-up. I replace the sponge on my Philosophy Supernatural Foundation/Powder about every 2 weeks because after 2 weeks with the same sponge I begin to break on all over. Please Help!!!

Amy