my father had open heart surgery May., 2013. he has had a chest wound for approximately 5 months in which a wound specialist removed infected sutures. The wound continues to drain infection. A bubble that looks like a clear blister starts at the middle of the chest scar, it fills with infection. Antibiotics work for only a short time, then the bubble reappears. He has been on Amoxicillin now for 14 days with another 14 days prescribed. Is this normal and is there anything you can tell me about the cause and treatment? thank you!