ABSTRACT
Sonicates of Mycobacterium intracellulare grown in synthetic medium were separated into ammonium sulfate (50%) precipitable and nonprecipitable fractions. Gel filtration of the precipitable fraction through columns of Sephacryl S-300 resulted in four fractions labeled A, B, C and D in order of elution. Fractions C and D were further fractionated into 12 and 13 subfractions, respectively. The subfractions were examined for reactivity by rocket immunoelectrophoresis (R-IE) procedures and by skin tests in homologously and heterologously immunized guinea pigs (M. kansasii, M. fortuitum, M. marinum, M. scrofulaceum and M. bovis). Extensive sharing of antigenic determinants was observed for all of the reactive subfractions by R-IE. None of the subfractions showed significant skin test specificity. Possible reasons for the nonspecificity are discussed.
Subject(s)
Antigens, Bacterial/immunology , Mycobacterium avium/immunology , Mycobacterium/immunology , Animals , Antigens, Bacterial/isolation & purification , Chromatography, Gel , Cross Reactions , Epitopes/analysis , Female , Guinea Pigs , Immunoelectrophoresis/methods , Skin Tests , Species Specificity , UltrasonicsABSTRACT
Bactericidal and enzyme-linked immunosorbent assays were used to determine the immunoglobulin classes responsible for group- and type-specific immunity to Neisseria meningitidis among healthy, unvaccinated individuals and persons who received group-B N meningitidis polysaccharide-serotype-2 protein vaccine. Bactericidal antibodies to the group B polysaccharide were primarily IgM; only a few individuals had both IgM and IgG antibodies. IgG bactericidal antibodies were detected only in those individuals with high IgM-antibody levels to group B meningococci. Increased levels of bactericidal antibodies to the group-B polysaccharide were infrequently found in vaccinees, possibly because of high prevaccination bactericidal-antibody levels. Bactericidal antibodies to the group-C polysaccharide were IgM, IgG, or both. Vaccine-induced antibodies to lipopolysaccharide were not bactericidal for a group-C serotype-2 strain with the lipopolysaccharide immunotype of the vaccine strain.
