[Phagocytic capacity of peritoneal exudate cells from rats immunized with a ribosomal preparation of Ty2 Salmonella typhi]

It was compared the activity of exudate peritoneal cells (EPC) obtained from CFW mice immunized either with Salmonella typhi Ty2 ribosomal fraction or whole-cell heat inactivated vaccine, both in comparison with EPC from sham-immunized. In the group which received ribosomal preparation, a subcutaneous dose equivalent to 100 micrograms of RNA in incomplete Freund's adjuvant (IFA) was initially used and 14 days after a booster of the same dose in IFA was given. A single dose of whole-cell heat inactivated vaccine, with 10(6) bacteria in IFA was employed subcutaneously in animals of the second group. EPC from controls and immunized mice were withdrawn at periods of 7, 11, 14, 18, 22, 25, 29 and 31 days after immunization and each sample was incubated in vitro in presence of live virulent non-opsonized S. typhi Ty2 in 1:200 cell-bacteria relation. Twenty four hours after cultivation, EPC bacterial capacity was determined after cell disruption and enumeration of survival bacteria were made through viable counts. Results have shown that EPC from mice immunized were more efficient in eliminating intracellular bacteria than those which came from sham-immunized animals. Also, it was found that EPC from mice immunized with ribosomal preparation were more efficient (maximum P = 0.005) than EPC from the mice which received killed whole bacteria.