Characteristics of pathogenic Neisseria meningitidis in Moscow: prevalence of 'non-European' strains

OBJECTIVE: To investigate the distribution of serogroups, serotypes and subtypes, and susceptibility to antibiotics, of 75 strains isolated from patients with systemic meningococcal disease in Moscow in 1993--95. RESULTS: In contrast to the situation in most European countries, 21% of group A strains were found. Sixty-nine per cent of the strains were non-serotypeable using the current panel of antibodies, and 21% of strains were non-subtypeable. Twenty-nine different serotype---subtype combinations were found among 69 strains of group A, B and C. No combination predominated clearly; relatively more frequent strains had the formulae B:NT:P1.2, A:4:P1.5, 10 and C:4:P1.10. Recently, such strains have been very rare in western Europe; in contrast, the strains predominating in western Europe were not found in Moscow. All strains were sensitive to penicillin, chloramphenicol and rifampicin. CONCLUSIONS: Moscow strains of Neisseria meningitidis demonstrated a substantial diversity of serotypes and subtypes that probably corresponded to a post-epidemic situation in Russia. The obvious difference in circulating strains and presumably in immunity of populations in western Europe and Russia increases the probability of mutual exchange of pathogenic strains and stresses the need for group B vaccine protecting from both western and eastern European variants of meningococci