title: Point mutation in meningococcal por A gene associated with increased endemic disease.
abstract: The por A gene, which encodes expression of meningococcal class 1 outer membrane protein, responsible for antigenic subtype specificity, has been cloned and sequenced in an isolate of Neisseria meningitidis (B:15:P1.7,16) from a patient in the Gloucester area with meningococcal meningitis. Comparison of the sequence with that of the equivalent gene from the P1.7,16 reference strain reveals a point mutation which generates a single aminoacid change in the epitope responsible for P1.16 specificity. Monoclonal antibodies with P1.16 specificity do not react with synthetic peptides that correspond to the altered epitope, and do not promote complement-mediated bactericidal killing of the isolate. Analysis of other strains shows widespread distribution of infections due to B:15:P1.7,16 meningococci with the altered epitope (P1.16b) in England and Wales.
authors.affiliation: Department of Microbiology, University of Southampton Medical School, UK.
authors.forename: B T
authors.initials: BT
authors.lastname: McGuinness
authors.forename: I N
authors.initials: IN
authors.lastname: Clarke
authors.forename: P R
authors.initials: PR
authors.lastname: Lambden
authors.forename: A K
authors.initials: AK
authors.lastname: Barlow
authors.forename: J T
authors.initials: JT
authors.lastname: Poolman
authors.forename: D M
authors.initials: DM
authors.lastname: Jones
authors.forename: J E
authors.initials: JE
authors.lastname: Heckels
mesh_terms: D000911:Antibodies, Monoclonal; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000032:analysis*; D004739:England / Q000453:epidemiology; D000939:Epitopes / Q000032:analysis*; D006801:Humans; D008585:Meningitis, Meningococcal / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D009345:Neisseria meningitidis / Q000145:classification / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013045:Species Specificity
chemical_list: D000911:Antibodies, Monoclonal; D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; D000939:Epitopes