Along with the bacteria "C. acnes", the bacterial species "Staphylococcus epidermidis" ("S. epidermidis") also takes a part in the physiopathology of acne vulgaris. The proliferation of "S. epidermidis" with "C. acnes" causes the formation of biofilms, which blocks the hair follicles and pores, creating an environment under the skin. This enables for increased growth of both "C. acnes" and "S. epidermidis" under the skin. The proliferation of "C. acnes" causes the formation of biofilms and a biofilm matrix, making it even harder to treat the acne.