Related Experiment Videos
Plasmid diversity in neisseriae.
Mark W J van Passel1, Arie van der Ende, Aldert Bart
1Center for Infection and Immunity, Amsterdam, Department of Medical Microbiology, Academic Medical Center, P.O. Box 22660, 1100 DD Amsterdam, The Netherlands.
Infection and Immunity
|July 25, 2006
Summary
Plasmids show extensive diversity in commensal Neisseria species, with some groups found in both pathogenic and commensal strains, indicating horizontal gene transfer. This suggests potential dissemination of phage-related sequences between these bacteria.
Area of Science:
- Microbiology
- Genomics
- Evolutionary Biology
Background:
- Horizontal gene transfer is crucial for prokaryotic evolution, with plasmids mediating DNA transfer.
- Plasmids are known vehicles for DNA transfer, yet their diversity and prevalence in nasopharyngeal Neisseria species remain understudied.
Purpose of the Study:
- To investigate the plasmid diversity and prevalence in commensal Neisseria lactamica and pathogenic Neisseria meningitidis.
- To characterize and classify plasmids found in these Neisseria species.
Main Methods:
- Sequencing of 12 plasmids from Neisseria isolates and analysis of 5 public database sequences.
- Nucleic acid sequence, mobilization, and replicase protein alignments for plasmid classification.
- Comparison of plasmid genetic organization and protein identity with the meningococcal disease-associated (MDA) phage.
Main Results:
- Nine of 18 N. lactamica strains harbored plasmids, while only one of 20 N. meningitidis strains contained a plasmid.
- Six distinct plasmid groups (I-VI) were identified based on sequence and protein analysis.
- Three plasmid groups were found in both pathogenic and commensal Neisseria, suggesting interspecies exchange.
- Plasmids showed resemblance to the MDA phage, with shared genetic organization and protein identity.
Conclusions:
- Extensive plasmid diversity exists among commensal Neisseria.
- Evidence of plasmid exchange between pathogenic and commensal Neisseria species.
- Resemblance to MDA phage suggests dissemination of phage-related sequences within Neisseria populations.