Monoclonal antibody to serotype 17 of Neisseria meningitidis and their prevalence in Brazilian States

Abstract

Neisseria meningitidis are gram-negative diplococci responsible for cases of meningococcal disease all over the world. The epidemic potential of N. meningitidis serogroup B and C is clearly a function of their serotype antigens more than of their capsular polysaccharides. Until recently, hiperimmune sera were used to detect typing antigens on the bacteria. The advent of monoclonal antibodies (MAbs) offered the opportunity to eliminate many of the cross-reactions and have improved the accuracy and reproducibility of meningococcal serotyping. We have produced a MAb to the outer membrane protein of the already existent serotype 17 that have been detected by the use of hiperimmune rabbit sera. The prevalence of this serotype epitope is low in the Brazilian strains. By using the MAb 17 we could not decrease the percentage of nontypeable serogroup C strains. However, there were a decreasing in nontypeable strains to 13% into serogroup B strains and to 25% into the other serogroups.

Clonal Distribution of Invasive Neisseria meningitidis Serogroup C Strains Circulating from 1976 to 2005 in Greater São Paulo, Brazil

“…MAbs for SerTs 8 (2725H6) and 15 (1951C8) OMVs, SDS-PAGE, and immunoblotting. Outer membrane vesicles (OMVs) were prepared and purified from a serogroup C NT:NST isolate (strain N.753/ 00), the isolate chosen for MAb production, as previously described (10,27,28,40). This serogroup C spinal fluid isolate was recovered in 2000 from a 17-yearold female in GSP with a fatal case of MD.…”

Correlation between Serological and Sequencing Analyses of the PorB Outer Membrane Protein in the Neisseria meningitidis Serotyping System

“…The current panel of 15 serotype-defining monoclonal antibodies (MAbs) reacts with only one PorB VR in any given strain; this finding has historically been interpreted to suggest that a given strain possesses only one immunodominant epitope on the entire PorB protein. Furthermore, 20 to 60% of meningococcal B and C isolates from any given population cannot be serotyped with these reagents, a problem which could distort the serotype prevalence data in defined areas (18,20,25). The characterization of VR loops and recent evidence that a serotype-specific sequence can reside in any of four loops suggest that the sensitivity of serotyping could be improved through further antigenic analysis of the PorB protein.…”

Sequencing of the porB Gene: a Step toward a True Characterization of Neisseria meningitidis

“…From 20 to 60% of meningococcal B and C isolates from any given population can be nontypeable (NT) using that panel of MAbs (11). This problem is already distorting the serotype prevalence data in defined areas (12,13,16).…”