IMMUNOGENIC COMPLEXES OBTAINED FROM SALMONELLA TYPHI-MURIUM AND SALMONELLA TYPHI-TY2 BY THE BACTERIAL ACETONE POWDER METHOD

  • 1 January 1979
    • journal article
    • research article
    • Vol. A130  (1) , 47-60
Abstract
An immunogenic complex was isolated from S. typhimurium and another from S. typhi Ty2 by the bacterial acetone powder method which eliminated the cell wall, the DNA almost completely and the membrane phospholipids. The complexes were denominated new vaccines. The S. typhimurium new vaccine induced, even at doses of 0.5 .mu.g dry wt per mouse, a high degree of protection against challenge of the virulent microorganism. By immunoelectrophoresis, 21 antigen-antibody [Ag-Ab] systems could be detected, 2 of them corresponding to O Ag. The S. typhi Ty2 new vaccine induced better protection than the standard vaccine (heat-phenol inactivated typhoid vaccine) when both vaccines were compared in the relative potency test. The new vaccine had very low toxicity when inoculated in humans at doses of 1 .mu.g dry wt and elicited a high Ab titer (1/1790 mean of 10 sera) in 75% of the tested population as estimated by complement fixation. The standard vaccine induced a low Ab titer (1/222, mean of 5 sera) in 50% of the humans inoculated with 108 bacterial cells. The new vaccine did not induce undesirable effects whereas the standard vaccine induced an important inflammatory process in 100% of the cases, with intense local pain in 67% 24 h post-inoculation.