Related Experiment Video

Updated: Aug 19, 2026

Inducing Meningococcal Meningitis Serogroup C in Mice via Intracisternal Delivery
10:03

Inducing Meningococcal Meningitis Serogroup C in Mice via Intracisternal Delivery

Published on: November 5, 2019

Sequence variation in the porB gene from B:P1.4 meningococci causing New Zealand's epidemic

Kristin H Dyet1, Diana R Martin

  • 1Communicable Disease Group, Institute of Environmental Science and Research, Porirua, New Zealand.

Journal of Clinical Microbiology
|February 8, 2005
PubMed

Insights

Meningococcal disease in New Zealand is linked to specific bacteria strains. Researchers found that variations in the porB gene, while originating from a common source, suggest divergence from the original strain, impacting vaccine development strategies.

Area of Science:

  • Microbiology
  • Epidemiology
  • Genetics

Background:

  • New Zealand has faced a meningococcal disease epidemic since 1991.
  • The epidemic is primarily caused by serogroup B meningococci (B:P1.7-2,4), belonging to the ST-41/ST-44 complex, lineage III.
  • While most epidemic strains express type 4 PorB, isolates with alternative porB genes have been detected.

Purpose of the Study:

  • To investigate the genetic relatedness of meningococcal isolates exhibiting alternative porB genes.
  • To understand the evolutionary mechanisms driving porB variation in epidemic strains.
  • To establish a baseline for assessing the impact of strain-specific vaccines on porB divergence.

Main Methods:

  • Multilocus restriction typing (MLRT) was employed.
  • MLRT results were validated using multilocus sequence typing (MLST).
  • Analysis focused on the genetic origins and variation of the porB gene in case isolates.

Main Results:

  • Isolates with alternative porB genes share a common clonal origin with the predominant B:P1.7-2,4 strain.
  • Strains with non-type 4 porB genes are considered divergent descendants of the original type 4 porB strains.
  • PorB variation is linked to mosaic gene formation, potentially through point mutation rather than horizontal gene transfer.

Conclusions:

  • Alternative porB genes in meningococcal isolates represent divergence from the primary epidemic strain.
  • Point mutation appears to be a significant mechanism for porB sequence variation.
  • This study provides crucial data for monitoring porB evolution in response to potential vaccine interventions.

More Related Videos

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/4306:06

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43

Published on: September 11, 2020

Heuristic Mining of Hierarchical Genotypes and Accessory Genome Loci in Bacterial Populations08:03

Heuristic Mining of Hierarchical Genotypes and Accessory Genome Loci in Bacterial Populations

Published on: December 7, 2021

Related Concept Videos

Comparing Copy Number Variations and SNPs02:26

Comparing Copy Number Variations and SNPs

Sequencing of the human genome has opened up several best-kept secrets of the genome. Scientists have identified thousands of genome variations that exist within a population. These variations can be a single nucleotide or a larger chromosomal variation.
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Mechanism of Antibiotic Resistance in MRSA01:25

Mechanism of Antibiotic Resistance in MRSA

Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...
Exon Recombination02:32

Exon Recombination

The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes. 
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Bacterial Meningitis01:24

Bacterial Meningitis

Bacterial meningitis is a severe infectious disease involving inflammation of the meninges, the protective membranes surrounding the brain and spinal cord. It occurs when pathogenic bacteria cross the blood–brain barrier and enter the cerebrospinal fluid. Common causative organisms include Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae type b, Listeria monocytogenes, and Escherichia coli K1. The exact route of entry varies by pathogen and host condition.Routes of Entry...
Single Nucleotide Polymorphisms-SNPs01:05

Single Nucleotide Polymorphisms-SNPs

A single nucleotide polymorphism or SNP is a single nucleotide variation at a specific genomic position in a large population. It is the most prevalent type of sequence variation found in the human genome. Point mutations that occur in more than 1% of the population qualify as SNPs. These are present once every 1000 nucleotides on an average in the human genome. Replacement of a purine with another purine (A/G) or a pyrimidine with another pyrimidine (C/T) is known as a transition. In contrast,...
Clinical Significance of Antibiotic Resistance01:25

Clinical Significance of Antibiotic Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...