Microbiology Question: Download Microbiology PDF

A 15 year old boy comes in to clinic with pain in his right ear. He is on his school swim team and spends about 2 hours per day in the pool. Along with the pain in his ear, he has watery drainage coming from the ear canal. On exam his vital signs are normal, and he appears healthy, but his left external ear looks quite red and there is copious watery, slightly green drainage coming from the ear. The organism mostly likely causing this is?