Heterogeneity of Serotypes of Neisseria meningitidis that Cause Endemic Disease

Abstract

Three collections of strains of Neisseria meningitidis that caused meningococcal disease during nonepidemic periods were serotyped to determine whether serotypes that cause endemic disease are more heterogeneous than those responsible for epidemic disease. Thirty-four strains isolated from pediatric patients in Houston, Texas, from February 1977 to March 1978 were of three separate serogroups and 11 serotypes; 27 contemporary (1977-1978) strains from predominantly military populations, obtained nationwide, were of six serogroups and six serotypes, while 11 strains isolated at military posts in the southwest United States from 1970 through 1976 were of four serogroups and five serotypes. Between 9% and 20% of the strains were nontypable, while type II strains which were responsible for the epidemics in the Northern and Western Hemispheres earlier in the 1970's, accounted for only 20%-44% of the strains. In contast to epidemics, which appear to be caused by a single serotype, endemic meningococcal disease appears to be caused by a broad, heterogeneous distribution of serotypes. Thus, development of a serotype-specific vaccine may have limited application to the prevention of endemic meningococcal disease.

Structural Relationships and Sialylation among Meningococcal L1, L8, and L3,7 Lipooligosaccharide Serotypes

“…In contrast, 70% of contemporaneously carried but non-invasive ET-5 complex strains expressed the L1,8,10 immunotype, and only 24% expressed L3,7,9 alone. We found that L3 and L7 also were expressed commonly by the diverse strains (19,26,43) that cause endemic disease (25/34; 74%), but these endemic L3,7 strains always expressed other LOS types, as well, including L8 (14) and L1 (3).…”

“…Strains-We have extensively characterized N. meningitidis strains 6940 (B:L1) the prototype L1 strain (16), and 126E (C:L1,8) (5,17,18), and 190I (B:L1,3,7) (19). We selected Neisseria lactamica strain 1207-0 and N. meningitidis strains 8529 (B:L3,7) and 8532 (B:L8) from the collections of the WRAIR.…”

“…LOS Serotyping-We used the SPRIA inhibition technique developed by Zollinger and Mandrell (1), with the original polyclonal rabbit antisera, to determine the LOS serotype(s) of 34 consecutive and unique blood and cerebrospinal fluid N. meningitidis isolates from epidemiologically unrelated pediatric patients with endemic disease in Houston, TX, from February 1977 through March 1978 (18,19,25,26). This system arbitrarily sets 35% of the inhibition of a type-specific antiserum by the homologous prototype strain as the threshold criterion for a serotype designation (1).…”

“…To our knowledge, this is the first application of LOS serotyping to strains that caused discrete, sporadic disease during a prolonged period in a single location and that were of diverse protein serotypes (19,26,43). With use of mAbs, Jones et al (6) found that 97% of hyperendemic ET-5 complex strains isolated from cases in the United Kingdom expressed the L3,7 immunotype and that only 13% of these invasive "L3,7,9" strains also expressed "L1, 8,10."…”

Immunogenic and protective properties of meningococcal serotype 2a protein in the hen-embryo model

“…proteins that are included in vaccines should be performed to determine their possible role in providing protection against group B meningococci of other serotypes (Holten, 1979) including non-typable strains that appear to be more prevalent during endemic periods of disease (Broud, Griffiss and Baker, 1979;Jones and Eldridge, 1981).…”