[Immunostimulation in an animal model using intestinal bacteria preparations]

The treatment of mice with an injection preparation consisting of killed R-tribes of non-pathogenous E. coli caused an increase in microbicidic activities in the animal's blood and effects a significant protection against consecutive infections with Salmonella typhimurium. The enhancement of the animal' resistance capacity appears to be non-specific, and connected with the activity of leucocytes. Oral application of preparations of intestinal bacteria led to increased resistance against consecutive infections with Salmonella typhimurium and Haemophilus influenzae. Three different oral vaccines have been used: Streptococcus faecalis and E. coli, a viable vaccine of non-pathogenous Streptococcus faecalis and a viable vaccine of E. coli. The enhancement of the resistance can be attributed to an induction of the chemotactic efficiency of the animal neutrophilic cells. The chemotactic response of these cells seems to be enhanced. The mode of action of both the other oral vaccines remains obscure.