Aureomycin and Terramycin Treatment of Pasteurella multocida Infection and Neomycin's in vitro Effects on P. multocida ∗

Abstract

Summary

(1) Both aureomycin and terramycin administered subcutaneously, either prophylactically or therapeutically (4 hours after infection) to white mice infected intra-peritoneally with 1,000 MLD₁₀₀ of P. multocida prolonged survival and lowered the fatility rate. Aureomycin was distinctly superior to terramycin; a single dose of 2 mg (133 mg/kg) of aureomycin resulted in a survival rate of approximately 87%, whereas that of the mice treated with terramycin was approximately 47%. Smaller doses (1 mg and less) of both antibiotics were less effective. Treatment over a period of 6 days did not increase substantially the survival rate as compared to a single dose treatment on day of infection. (2) In vitro neomycin was of the same bacteriostatic potency as streptomycin against 7 strains of P. multocida and was markedly superior against the eighth, streptomycin-resistant, strain.