Phase 1 Inclusion Criteria:  Patients having elective shoulder arthroplasty  Phase 1 Exclusion Criteria:  history of shoulder septic arthritis antibiotic use within 3 months prior to surgery recent treatment for acne Lacked fluency in English  Phase 2 Inclusion Criteria:  Patients having elective shoulder arthroplasty  Phase 2 Exclusion Criteria:  Lacked fluency in English