Protective effect of beta-glucan against systemic Streptococcus pneumoniaeinfection in mice

The antimicrobial effect of soluble beta-1,3-D-glucan from Sclerotinia scle rotiorum (SSG) was examined in mice experimentally infected intraperitoneal ly (i.p.) with Streptococcus pneumoniae serotypes 4 and 6B. SSG was adminis tered i.p. either 3 days before challenge or 3-48 h after challenge. The nu mber of bacteria in blood samples and the mouse survival rates were recorde d. Pre-challenge SSG administration protected Jose-dependently against both S. pneumoniae type 4 and 6B infections. SSG injected 24 h post-challenge h ad a curative effect against type 6B but not type 4 pneumococcal infection. The data demonstrate that SSG administered systemically protects against p neumococcal infection in mice. (C) 2000 Federation of European Microbiologi cal Societies. Published by Elsevier Science B.V. All rights reserved.