Identification and characterization of specific sequences encoding pathogenicity associated proteins in the genome of commensalNeisseriaspecies

Abstract

The distribution of distinct sequences in pathogenic and commensal Neisseria species was investigated systematically by dot blot analysis. Probes representing the genes of Rmp, pilin and IgA1 protease were found to hybridize exclusively to the chromosomal DNA of the pathogenic species, Neisseria gonorrhoeae and/or Neisseria meningitidis. In contrast, specific sequences for the genes of the porin protein Por and the opacity protein (Opa) were also detected in a panel of commensal Neisseria species such as N. lactamica, N. subflava, N. flava, N. mucosa and N. sicca. Using opa-specific oligonucleotides as probes in chromosomal blots, the genomes of the commensal Neisseria species show a totally reduced repertoire of cross-hybridizing loci compared to the complex opa gene family of N. gonorrhoeae. DNA sequence analysis of one opa-related gene derived from N. flava and N. sicca, respectively, revealed a large degree of homology with previously described gonococcal and meningococcal genes, e.g., a typical repetitive sequence in the leader peptide and the distribution of the hypervariable and conserved regions. This observation, together with the finding, that the gene is constitutively transcribed, leads to the assumption that some of the commensal Neisseria species may have the potential for the expression of a protein harboring similar functions as the Opa proteins in pathogenic Neisseriae.

Rapid characterization of outer‐membrane proteins in Neisseria lactamica by SELDI–TOF‐MS (surface‐enhanced laser desorption ionization–time‐of‐flight MS) for use in a meningococcal vaccine

“…Furthermore, proteins specific to N. meningitidis have been found at 55 and 35 kDa [26]. Wolf and Stern [27] reported that the sequence encoding RmpM is only present in the pathogenic Neisseria species; however, we report here the presence of a 27 kDa protein in N. lactamica OMVs.…”

“…PorB is also expressed as a homotrimer or a heterotrimer with PorA. The homotrimer can be created from either PorB2 or PorB3 depending on the strain, which induces the production of highly opsonic and bactericidal antibodies [27]. In addition, peaks A, F and N were identified as NspA by cross‐reaction with a meningococcal NspA monoclonal antibody (Me‐7).…”

The Biology of Neisseria Adhesins

“…A single meningococcal strain can harbour 3–4 opa genes ( opaA , opaB , opaD and opaJ ) [82,83], whilst up to 11 opa genes can be expressed in gonococci at separate loci throughout the genome [84]. The commensal strains N. subflava , N. mucosa and N. sicca , were shown to harbour one opa gene, whereas two opa genes were found in N. flava and in N. lactamica [85,86,87]. …”