Abstract
In the present studies on the intraperitoneal infection of staphylococci in mice, virulence enhancement with gastric mucin and immune effects of staphylococcal a-toxoid in the case of intraperitoneal challenge by staphylococci with mucin were investigated and the following results were obtained:
1. LD50in the intraperitoneal inoculation of staphylococci freshly isolated from supprative lesions decreased by addition of 0.2-0.2 ml of 5% gastric mucin suspension.
2. The degree of the decrease of LD50by addition of mucin was not always connected with the coagulase production of the strains. And the decrease was remarkable in the Smith strain etc., but not in the Terajima strain which was preserved for a long time.
3. Mice inoculated intraperitoneally with staphylococci and mucin were killed by septicemia, and the bacterial amounts in organs such as kidney, spleen, liver, heart and lung increased far more than those in the injection of the cocci without mucin.
4. Most of mice intraperitoneally challenged as above died in an earlier stage. The number of bacteria of various organs was measured at intervals after the inoculation and proved to be different in the course of time by the difference of strains and organs, but the increase of number could be recognized about four hours after the inoculation in every case.
5. Intraperitoneal challenge of staphylococci with mucin was found to be a useful method for the observation of immune effects of staphylococcal a-toxoid.
6. In addition to the immune effects, the appearance of hypersensitiveness in mice by staphylococcalα-toxoids could also be demonstrated by these intraperitoneal challenge.
