The purification and protective capacity of Bordetella pertussis outer membrane proteins.

The whole cell vaccine (WCV) of Bordetella pertussis is protective in the intracerebral (i.c.) mouse protection assay. We found a correlation between the i.c. mouse protection assay potency and the presence of the virulence-associated outer membrane proteins (OMPs) in outer membrane complexes (OMC). The virulence-associated 92, 32 and 30 kDa OMPs were purified and the N-terminal amino acid sequences were determined. The N-terminal amino acid sequences of the 30 and 32 kDa OMPs show homology with the C-terminal fragment of the P.93 precursor of the 69 kDa OMP (pertactin). The purified 32 kDa OMP was protective in the i.c. test when presented as mixed protein-detergent micelles. The 92 kDa OMP became a protective antigen when nonprotective levels of pertussis toxin were added. We found a correlation between the i.c. mouse protection value and the 92 kDal38 kDa (porin) ratio in OMC preparations.

Improved serodiagnosis of whooping cough caused by Bordetella pertussis by determination of IgG anti-LPF antibody levels.

The enzyme-linked immunosorbent assay (ELISA) has been used for the determination of the isotype and the specificity of Bordetella pertussis serum antibodies induced by natural infection and by vaccination. In a previous study (J. Med. Microbiol., 16, 417-426 (1984)) it was shown that the presence of pertussis serum IgA antibodies could be used as an indicator of infection: IgA antibodies were not induced by vaccination nor transported from the mother to the serum of the child. In the present study ELISA was used for the determination of IgA, IgM and IgG antibodies. From the results obtained with sera from suspected pertussis cases, it was concluded that antibodies against FHA are hardly induced by infection, in contrast to anti-LPF (determined in a fetuin sandwich ELISA) and anti-LPS antibodies. In view of the lower standard deviation of the mean anti-LPF antibody titer these antibodies were studied more extensively. From a number of bacteriologically proved pertussis cases, it was shown that high levels of IgG anti-LPF antibodies were found before IgA antibodies could be detected. On the other hand, we had the impression that IgG antibodies declined more rapidly than IgA antibodies. One has, however, to take into account that IgG antibodies are transferred from mother to child. From assay of sera from infants prior to, during and two months after vaccination (ages of vaccination: 3, 4, 5 and 12 months) it was concluded that IgG anti-LPF antibodies were induced to a much lower level by DTP-polio vaccination (10 O.U. per dose) than by natural infection.(ABSTRACT TRUNCATED AT 250 WORDS)