Related Experiment Video

Updated: Aug 21, 2026

Total Protein Extraction and 2-D Gel Electrophoresis Methods for Burkholderia Species
08:31

Total Protein Extraction and 2-D Gel Electrophoresis Methods for Burkholderia Species

Published on: October 15, 2013

Role of quorum sensing in the pathogenicity of Burkholderia pseudomallei

Ricky L Ulrich1, David DeShazer1, Ernst E Brueggemann1

  • 1Bacteriology Division1 and Toxinology/Aerobiology Division2, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), 1425 Porter Street, Fort Detrick, MD 21702-5011, USA 3Microbiology, Dstl, CBS Porton Down, Salisbury SP4 0JQ, UK 4Orion Genomics, Center for Emerging Technologies, 4041 Forest Park, St. Louis, MO 63108, USA.

Journal of Medical Microbiology
|October 22, 2004
PubMed

Insights

Quorum sensing (QS) genes in Burkholderia pseudomallei are crucial for pathogenicity in animal models. Disrupting QS increases survival and reduces colonization, though it doesn't impact exoproduct secretion.

Area of Science:

  • Microbiology
  • Bacterial Pathogenesis
  • Molecular Biology

Background:

  • Burkholderia pseudomallei causes melioidosis in humans and animals.
  • The role of quorum sensing (QS) in B. pseudomallei pathogenicity via inhalation or intraperitoneal challenge is not well understood.

Purpose of the Study:

  • To investigate the role of QS in the in vivo pathogenicity of B. pseudomallei.
  • To identify the specific QS genes (luxI and luxR homologues) involved in animal pathogenicity.

Main Methods:

  • In vivo studies using BALB/c mice (inhalational exposure) and Syrian hamsters (intraperitoneal challenge).
  • Genetic manipulation of B. pseudomallei to create luxI mutants.
  • Mass spectrometry to analyze signaling molecules.
  • Heterologous expression in Escherichia coli.
  • LD50 determination and organ colonization assessment.
  • Semi-quantitative plate assays for exoproduct secretion.

Main Results:

  • B. pseudomallei encodes at least three luxI and five luxR homologues involved in pathogenicity.
  • Mutagenesis of the QS system increased survival time and reduced organ colonization in aerosolized mice.
  • QS mutants showed a significant increase in LD50 in Syrian hamsters.
  • QS does not appear to affect lipase, protease, or phospholipase C biosynthesis/secretion.

Conclusions:

  • B. pseudomallei possesses multiple luxIR genes that regulate pathogenicity.
  • Disruption of QS significantly reduces B. pseudomallei's pathogenicity in animal models.
  • QS regulation of exoproduct secretion in B. pseudomallei was not observed in this study.

More Related Videos

A Hydroponic Co-cultivation System for Simultaneous and Systematic Analysis of Plant/Microbe Molecular Interactions and Signaling11:16

A Hydroponic Co-cultivation System for Simultaneous and Systematic Analysis of Plant/Microbe Molecular Interactions and Signaling

Published on: July 22, 2017

Time-lapse Imaging of Bacterial Swarms and the Collective Stress Response06:26

Time-lapse Imaging of Bacterial Swarms and the Collective Stress Response

Published on: May 23, 2020

Related Concept Videos

Gene Regulation in Microbial Communities: Quorum Sensing01:28

Gene Regulation in Microbial Communities: Quorum Sensing

Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
Bacterial Signaling01:30

Bacterial Signaling

Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell...
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...
Global Regulatory Systems01:28

Global Regulatory Systems

Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
Stringent Response in E. coli01:23

Stringent Response in E. coli

Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
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...