LY146032 compared with penicillin G in experimental aortic valve endocarditis caused by group G streptococci.

Rabbits with group G streptococcal aortic endocarditis received no therapy (controls); repeated doses of procaine penicillin G, 300 mg/kg (body weight) per day, administered intramuscularly; or LY146032, a new peptolide antibiotic, 20 mg/kg per day, administered intravenously. Penicillin G and LY146032 reduced mean intravegetation group G streptococcal densities significantly below those observed in controls at both day 3 and day 6 of therapy. Penicillin G effected a more rapid clearance of intravegetation streptococci than LY146032 by day 3, but not by day 6, of therapy.