IMMUNE-RESPONSE OF RABBITS IMMUNIZED WITH OUTER-MEMBRANE PROTEINS (PORINS) OF SALMONELLA-DUBLIN 51

Porins complexed with polysaccharide of Salmonella dublin 51 used for immunization of rabbits proved non-toxic. Agglutinin titre ranged from 1:40 to 1:320 against '0' 9, 12 antigen. Titre against porins by dot- ELISA was 1:100-1:400. Antiporins in the serum samples of 2 rabbits we re demonstrable at 5 weeks postimmunization by counter-immunoelectroph oresis (CIE), while it was detected in the 4 rabbits at 6 weeks post-c hallenge before sacrifice by both immunodiffusion and CIE. The immedia te type skin hypersensitivity reaction was 12.00-15.00 mm (skin thickn ess) at 6 hr post-antigen inoculation in the rabbits, at 5 weeks post- immunization. Skin biopsy collected at 6 hr (peak skin reaction) post- antigen inoculation revealed infiltration of neutrophils. The antipori n in the serum samples of all the rabbits were also detected by dot-EL ISA at 6 weeks post-challenge before sacrifice. The cell-mediated immu ne response (leucocytemigration inhibition and delayed type of skin hy persensitivity reaction) in the immunized rabbits was insignificant. T he percentage protection of the immunized rabbits was 66.66% (statisti cally significant) against oral challenge.