i have read your query. yes acne is caused by a bacteria called propionibacterium acnes but beside this other factors also play in forming acne. change in keratinization pattern in pilosebaceous unit which leads to a keratinous material to cause blocking of sebum secretion leads to comedone formation. these comedones plugging and complex interaction between androgens and bacteria in the plugged pilosebaceous units leads to inflammation. this is the reason for using antibiotics for the management of acne along with medicine like retinoids (adapalene or isotretinoin) for maintaining keratinization. for further doubts consult a dermatologist online --> <link>
why do antibiotics clear acne?