Effects of PSK on resistance to bacterial infection in splenectomized mice.

Nontumor-bearing C3H/He mice were splenectomized and intravenously inoculated 7 days later with Streptococcus pneumoniae, Pseudomonas aeruginosa, or Escherichia coli. The survival rate was reduced by splenectomy in the animals inoculated with S. pneumoniae, but did not change in those inoculated with P. aeruginosa or E. coli. When splenectomy was performed 2 days after transplantation of X5563, and bacteria were inoculated 7 days after the operation, the survival rate was reduced even in those inoculated with P. aeruginosa or E. coli, and elimination of the bacteria from the blood and liver was delayed. This reduction in resistance to infection was alleviated by oral administration of PSK after the splenectomy.