Related Experiment Video

Updated: Mar 29, 2026

Phage Phenomics: Physiological Approaches to Characterize Novel Viral Proteins
09:40

Phage Phenomics: Physiological Approaches to Characterize Novel Viral Proteins

Published on: June 11, 2015

13.0K

Characterization of MDAΦ, a temperate filamentous bacteriophage of Neisseria meningitidis

Julie Meyer1,2,3,4, Terry Brissac1,4,3,2, Eric Frapy1,4,3,2

  • 1Institut Necker-Enfants Malades, 14 Rue Maria Helena Vieira Da Silva, CS 61431, 75014, Paris, France.

Microbiology (Reading, England)
|November 26, 2015
PubMed

Insights

The meningococcal disease associated (MDA) island encodes a functional filamentous bacteriophage. This phage infects Neisseria meningitidis strains, potentially contributing to invasive disease.

Area of Science:

  • Microbiology
  • Genomics
  • Bacteriology

Background:

  • The mechanisms underlying Neisseria meningitidis invasiveness remain largely unknown.
  • Comparative genomics revealed a conserved 8 kb island in invasive strains.

Purpose of the Study:

  • To investigate the nature and function of the meningococcal disease associated (MDA) island.
  • To determine if the MDA island represents a functional bacteriophage.

Main Methods:

  • Comparative genomics
  • Molecular biology techniques
  • Immunolabelling
  • Bacteriophage infection assays

Main Results:

  • The MDA island exhibits characteristics of a filamentous prophage, similar to CTXΦ.
  • The MDA prophage utilizes the type IV pilus secretin PilQ for productive cycle and secretion.
  • Specific genes (orf1, orf2, orf9) are essential for the replicative form.
  • Filamentous particles (approx. 1200 nm), coated with ORF4, are present on the bacterial surface.
  • The MDA bacteriophage infects N. meningitidis strains using type IV pili as a receptor (via ORF6).

Conclusions:

  • The MDA island encodes a functional filamentous bacteriophage.
  • This bacteriophage is capable of producing infectious particles and infecting N. meningitidis.
  • The MDA bacteriophage may play a role in meningococcal pathogenesis and invasiveness.

More Related Videos

Author Spotlight: An Adapted Optical Density-Based Microplate Assay for Characterizing Actinobacteriophage Infection03:33

Author Spotlight: An Adapted Optical Density-Based Microplate Assay for Characterizing Actinobacteriophage Infection

Published on: June 30, 2023

2.9K
Visualisation and Quantification of Intracellular Interactions of Neisseria meningitidis and Human α-actinin by Confocal Imaging12:58

Visualisation and Quantification of Intracellular Interactions of Neisseria meningitidis and Human α-actinin by Confocal Imaging

Published on: October 24, 2010

18.7K

Related Concept Videos

DNA Bacteriophages01:26

DNA Bacteriophages

Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
1.4K
Lytic Cycle of Bacteriophages01:30

Lytic Cycle of Bacteriophages

Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the...
80.0K
Regulation of Bacterial Virulence01:28

Regulation of Bacterial Virulence

Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
36
Viral Replication: Lytic Cycle01:20

Viral Replication: Lytic Cycle

Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized lytic replication cycle in Escherichia coli (E. coli). This process ensures the rapid proliferation of the virus while ultimately leading to the destruction of the bacterial host.Attachment and DNA InjectionThe infection process begins with the recognition and binding of the T4 phage to the E. coli cell surface. Tail fibers of the phage...
2.5K
Bacterial Phylum Tenericutes01:24

Bacterial Phylum Tenericutes

The phylum Tenericutes, which includes the single class Mollicutes, comprises bacteria that lack cell walls. The term "Mollicutes" derives from the Latin word mollis, meaning "soft." These organisms are among the smallest known and are commonly referred to as mycoplasmas due to the prominence of the genus Mycoplasma, which includes well-known human pathogens. Despite their inability to stain gram-positively (a result of their lack of cell walls), mycoplasmas are phylogenetically related to the...
584
Bacterial Phylum Proteobacteria01:26

Bacterial Phylum Proteobacteria

Proteobacteria, one of the largest and most diverse bacterial phyla, encompasses a wide range of Gram-negative bacteria distinguished by their outer membrane composed of lipopolysaccharides. These microorganisms exhibit various metabolic capabilities, including phototrophy, chemolithotrophy, and heterotrophy, and thrive in diverse environments from soil to aquatic systems and host-associated niches. The phylum is divided into six classes: Alphaproteobacteria, Betaproteobacteria,...
1.2K