The answer is absoloutly YES! Its quite common that I come across some people that don’t cleanse their makeup brushes however it is very important that you do! Bacteria harbours on brushes and every time you use a brush it transfers bacteria too and from your products, to your brushes and your face. This is what can commonly cause spots.
You can purchase a brush cleanser from most Cosmetic companies; the one that I use is MAC’s Brush Cleanser, its very gentle on the hairs of your makeup brush and is a quick fix to sanitise your brush of any bacteria.