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Distribution of specific DNA sequences among pathogenic and commensal Neisseria species
Abstract:
Several traits, including pili and the outer membrane proteins P.II and H.8, have been associated with pathogenic Neisseria species. We examined several Neisseria species for DNA sequence homology to cloned pilin, P.II, and H.8 genes. Strains of Neisseria gonorrhoeae and N. meningitidis showed hybridization to all of these genes. Commensal strains showed little hybridization to any of these genes. Strains of N. lactamica and N. cinerea showed intermediate patterns of hybridization. Generally, organisms that expressed a given trait showed DNA homology to the corresponding cloned gene. However, we observed pili on some commensal strains that did not show hybridization to the cloned gonococcal pilin gene.
Insights
Pathogenic Neisseria species, like Neisseria gonorrhoeae and Neisseria meningitidis, possess genes for pili and outer membrane proteins P.II and H.8. Commensal Neisseria strains generally lack these specific gene sequences.
Area of Science:
- Microbiology
- Genetics
- Molecular Biology
Background:
- Pathogenic Neisseria species possess specific traits like pili and outer membrane proteins (P.II, H.8).
- Understanding the genetic basis of these traits can differentiate pathogenic from commensal Neisseria.
Purpose of the Study:
- To investigate DNA sequence homology of pilin, P.II, and H.8 genes across various Neisseria species.
- To correlate the presence of these genes with pathogenic or commensal status.
Main Methods:
- DNA hybridization assays were performed using cloned pilin, P.II, and H.8 genes.
- Various Neisseria species, including pathogenic and commensal strains, were analyzed.
Main Results:
- Neisseria gonorrhoeae and Neisseria meningitidis strains hybridized strongly to all tested genes.
- Commensal Neisseria strains showed minimal hybridization.
- N. lactamica and N. cinerea displayed intermediate hybridization patterns.
- A discrepancy was noted where some commensal strains with pili did not hybridize to the cloned gonococcal pilin gene.
Conclusions:
- The presence of pilin, P.II, and H.8 genes is strongly associated with pathogenic Neisseria species.
- While generally true, exceptions exist, suggesting potential variations in pilin gene sequences among commensal strains.