The use of oligonucleotide probes for meningococcal serotype characterization

Abstract

In the present study we examine the potential use of oligonucleotide probes to characterize Neisseria meningitidis serotypes without the use of monoclonal antibodies (MAbs). Antigenic diversity on PorB protein forms the bases of serotyping method. However, the current panel of MAbs underestimated, by at least 50% the PorB variability, presumably because reagents for several PorB variable regions (VRs) are lacking, or because a number of VR variants are not recognized by serotype-defining MAbs. We analyzed the use of oligonucleotide probes to characterize serotype 10 and serotype 19 of N. meningitidis. The porB gene sequence for the prototype strain of serotype 10 was determined, aligned with 7 other porB sequences from different serotypes, and analysis of individual VRs were performed. The results of DNA probes 21U (VR1-A) and 615U (VR3-B) used against 72 N. meningitidis strains confirm that VR1 type A and VR3 type B encode epitopes for serotype-defined MAbs 19 and 10, respectively. The use of probes for characterizing serotypes possible can type 100% of the PorB VR diversity. It is a simple and rapid method specially useful for analysis of large number of samples.

Heterogeneity in non‐epitope loop sequence and outer membrane protein complexes alters antibody binding to the major porin protein PorB in serogroup B Neisseria meningitidis

“…It has long been recognized that meningococcal serotyping methods are problematic and may dramatically underrepresent the diversity of circulating PorB loop sequences. Because serotyping methods rely on the high‐affinity interaction of mAbs with distinct conformational epitopes – which may be diminished by minute changes in the epitope‐specific amino acid sequence – recognition by serotype‐specific antibodies may not always be possible, and roughly half of all meningococcal strains have been estimated to be nontypeable by these methods (Sacchi et al ., ).…”

Rapid Genetic Grouping of Factor H-Binding Protein (Genome-Derived Neisserial Antigen 1870), a Promising Group B Meningococcal Vaccine Candidate

“…A conventional PCR-based approach also has been used to assign capsular groups (16) and PorB variable region types (18).…”