Related Experiment Video

Updated: May 16, 2026

Use of Galleria mellonella as a Model Organism to Study Legionella pneumophila Infection
12:30

Use of Galleria mellonella as a Model Organism to Study Legionella pneumophila Infection

Published on: November 22, 2013

Infection of nonphagocytic host cells by legionella

Shandra R Day1, Costi D Sifri, Paul S Hoffman

  • 1Division of Infectious Diseases and International Health, University of Virginia Health System, Charlottesville, VA, USA.

Methods in Molecular Biology (Clifton, N.J.)
|November 15, 2012
PubMed

Insights

Legionella pneumophila infects various cells, including L929 fibroblasts and HeLa cells. Assays using these cells help measure bacterial infectivity and study virulence factors.

Area of Science:

  • Microbiology
  • Cell Biology
  • Pathogen Research

Background:

  • Legionella pneumophila is an intracellular pathogen.
  • It infects protozoa and mammalian cells like macrophages, fibroblasts, and epithelial cells.
  • Studying L. pneumophila infection in non-phagocytic cells aids in understanding invasion and virulence.

Purpose of the Study:

  • To describe detailed methods for evaluating L. pneumophila infectivity.
  • To enable comparison of virulence among different bacterial strains.
  • To facilitate the study of invasion mechanisms and pathogen development.

Main Methods:

  • L929 plaque assay: virulent L. pneumophila strains form plaques on L929 cell monolayers, enumerated to measure infectivity.
  • HeLa cell invasion assay: evaluates L. pneumophila invasiveness in HeLa cells.
  • Both methods allow tracking of bacterial development, including cyst-like forms.

Main Results:

  • The L929 plaque assay provides a quantifiable measure of L. pneumophila infectivity.
  • The HeLa cell assay allows for the assessment of relative infectivity and invasion mechanisms.
  • These assays are effective for studying virulence factors and bacterial lifecycle stages.

Conclusions:

  • Standardized assays using L929 and HeLa cells are valuable tools for Legionella research.
  • These methods facilitate the study of L. pneumophila virulence, invasion, and development.
  • The described assays contribute to a better understanding of this important bacterial pathogen.

More Related Videos

Tractable Mammalian Cell Infections with Protozoan-primed Bacteria13:54

Tractable Mammalian Cell Infections with Protozoan-primed Bacteria

Published on: April 2, 2013

Legionella pneumophila Outer Membrane Vesicles: Isolation and Analysis of Their Pro-inflammatory Potential on Macrophages08:34

Legionella pneumophila Outer Membrane Vesicles: Isolation and Analysis of Their Pro-inflammatory Potential on Macrophages

Published on: February 22, 2017

Related Concept Videos

Colonisation of Pathogens01:25

Colonisation of Pathogens

Pathogen colonization of host tissues is a critical step in the development of infectious diseases. Various pathogenic microorganisms, including bacteria, fungi, viruses, and protozoa, have evolved complex strategies to attach to, invade, and persist within host environments. These mechanisms enable pathogens to establish infections, evade immune responses, and resist antimicrobial treatments.Attachment to Host CellsIn bacteria, colonization typically begins with adherence to host epithelial...
Atypical Pneumonia01:14

Atypical Pneumonia

Atypical pneumonia, often caused by Mycoplasma pneumoniae, is a form of pulmonary infection that differs from the classical presentation of bacterial pneumonia in both its cause and clinical symptoms. Mycoplasma pneumoniae is a pleomorphic bacterium notable for its lack of a rigid cell wall. This structural characteristic imparts resistance to beta-lactam antibiotics and significantly influences the bacterium’s behavior within the human host.Other pathogens responsible for the disease include...
Bacterial Phylum Spirochaetes01:30

Bacterial Phylum Spirochaetes

Spirochetes, unique bacteria in the phylum Spirochaetes, are gram-negative, motile, tightly coiled, slender, and flexible. They inhabit aquatic sediments and animals, with some causing diseases like syphilis. Spirochetes are classified into eight genera based on habitat, pathogenicity, phylogeny, and characteristics.Their distinctive motility arises from endoflagella, located within the cell’s periplasm. These endoflagella anchor at the cell poles and extend along the cell length, encased by a...
Viral Replication: Lysogenic Cycle01:16

Viral Replication: Lysogenic Cycle

The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. This process is primarily observed in temperate phages, such as bacteriophage lambda (λ), which infects Escherichia coli. The cycle allows the viral genome to persist across bacterial generations while keeping host cells viable.Integration of the Viral GenomeUpon infection, bacteriophage lambda attaches to the bacterial surface and injects its...
Lysogenic Cycle of Bacteriophages00:43

Lysogenic Cycle of Bacteriophages

In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
Reservoir of Infection01:30

Reservoir of Infection

Infectious diseases arise from intricate interactions between pathogens and their reservoirs. A reservoir of infection refers to the natural habitat where a pathogen lives, grows, and multiplies, serving as a continual source of infection. Reservoirs are broadly classified as either living or nonliving, and each plays a unique role in disease transmission, significantly influencing public health interventions and control strategies.Humans act as reservoirs for a wide array of pathogens,...