[Meningococcal meningitis in Spain (1878-1987). VI. Evolution of the proteic subtypes within the serotypes 2 and 15 of Neisseria meningitidis during the epidemic wave].

We have serotyped 620 strains of Neisseria meningitidis, isolated from patients between 1978-1987. These strains, belonging to serotypes 2 and 15, were the most prevalent ones detected during the last epidemic outbreak in Spain. These strains were analyzed by means of polyacrylamide gel electro-phoresis and monoclonal antibody coagglutination, to differentiate subtypes into type 15 and type 2 complex (2a, 2b and 2c types). The proportion of type 2b strains is quite high in group B, and the proportion of subtypes P1.15 and P1.16 is very similar in the same serogroup. We compared the results with those obtained in other countries in our geographical area.