TY - JOUR T1 - THE ANTIBACTERIAL ACTIVITY OF PENICILLIN IN EXPERIMENTAL INFECTIONS OF MICE WITH C. DIPHTHERIAE JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 120 LP - 127 VL - 84 IS - 2 AU - N. ERCOLI AU - M. N. LEWIS AU - LUCILLE J. MOENCH Y1 - 1945/06/01 UR - http://jpet.aspetjournals.org/content/84/2/120.abstract N2 - 1. Experimental systemic and local infections of mice with C. diptheriae are described. In the systemic, principally bacillary, infection, penicillin exerted a marked activity, while it had no effect when administered topically on the local infection. 2. Penicillin had no effect on diphtheria toxin in guinea pigs injected with lethal doses of toxin-antitoxin mixtures. 3. High doses of penicillin delayed the death of guinea pigs infected with cultures of C. diphtheriae. The delay of death is considered due to a decrease of toxin formation induced by the antibacterial effect of penicillin. 4. Cultures of diphtheria bacilli grown in presence of penicillin do not lose their toxigenic properties if tested on the skin of rabbits. 5. Only extremely high doses of penicillin (10,000 units/cc.) neutralize diphtheria toxin in vitro. 6. It is concluded that penicillin will not be effective in human cases characterized by toxemia, while it might be useful in certain conditions of predominantly bacillary character, such as very early cases or carriers. ER -