Phase I Study of Safety and Immunogenicity of ADU-623

Four doses of IV ADU-623 at a dose of 3 x 10\^7cfu

Four doses of IV ADU-623 at a dose of 3 x 10\^8cfu

Four doses of IV ADU-623 at a dose of 3 x 10\^9cfu

A 3-day course of oral amoxicillin (500 mg three times per day) or trimethoprim/sulfamethoxazole in penicillin-allergic patients (160 mg trimethoprim / 800mg sulfamethoxazole at 12 hour intervals) will be initiated for each patient 3 days following each dose of ADU-623. Patients will receive a 7-day course of antibiotics starting at the end of treatment visit.