COMPARATIVE IMMUNOGENICITY OF UREA AND EDTA EXTRACTED CELL-SURFACE COMPONENTS FROM SALMONELLA-TYPHIMURIUM IN MICE

Swiss albino mice (group la to 4g) immunized with urea extracted cell surface components (UECSCs), recycled UECSCs, peak I(P I), recycled UE CSCs pooled peaks (PI+PII+PIII) and EDTA extracted CSCs of S. tryphimu rium 163, respectively, showed humoral (HIR) and cellular immune respo nses (CIR). The HIR was exhibited by increase in immunoglobulin (Ig) l evel at weekly intervals postimmunization (PI) anti postchallenge (PC) , and immediate type footpad thickness (ITFT) at 6 hr postinoculation of eliciting antigen (PEA) in the left hind footpad. However. the mice in group 4f immunized with EDTA extracted CSC showed comparatively hi gher level of 1g at 4 weeks P1 and 3 weeks PC. In immunized mice treat ed with carrageenan (group 1b, 2d, 4g), the Ig level decreased abruptl y at 1.2 and 3 weeks PC. The CIR was exhibited by delayed type footpad thickness (DTFT) at 72 hr PEA, nitroblue tetrazolium (NBT) reduction test at weekly PI and PC. Postchallenge heavy mortality was observed i n mice treated with carrageenan (macrophage depleted).The difference b etween the per cent protection of immunized groups(1a,2c, 3e) as well as immunized and carrageenan treated groups (1b, 2d) and mock vaccinat ed group (5h) was statistically significant. The corresponding-values in groups i.e. 4f, 4g and jh, were highly significant. The liver and s pleen of the sacrificed mice surviving challenge in the immunized grou ps showed more immunological, less immunopathological and pathological alterations on microscopic examination. while mice in group 4f showed only immunological alterations. The EDTA extracted CSCs were more imm unogenic and protective compared to UECSCs in mice.