Related Experiment Video

Updated: Jun 17, 2026

Establishment of a High-throughput Setup for Screening Small Molecules That Modulate c-di-GMP Signaling in Pseudomonas aeruginosa
11:31

Establishment of a High-throughput Setup for Screening Small Molecules That Modulate c-di-GMP Signaling in Pseudomonas aeruginosa

Published on: June 30, 2016

Growth-related changes in intracellular spermidine and its effect on efflux pump expression and quorum sensing in

Ying Ying Chan1, Kim Lee Chua1

  • 1Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, 117597, Singapore.

Microbiology (Reading, England)
|December 26, 2009
PubMed

Insights

The Burkholderia pseudomallei BpeAB-OprB pump regulates spermidine homeostasis and effluxes antibiotics. Inhibiting spermidine synthesis reduces efflux pump activity and may offer therapeutic benefits.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • The Burkholderia pseudomallei BpeAB-OprB pump is a resistance-nodulation-division (RND) family efflux pump.
  • This pump is known to efflux antibiotics and acylhomoserine lactones (AHLs) involved in quorum sensing.

Purpose of the Study:

  • To investigate the role of the BpeAB-OprB pump in spermidine homeostasis.
  • To explore the impact of spermidine on efflux pump expression and function.
  • To evaluate potential therapeutic strategies targeting spermidine metabolism.

Main Methods:

  • Studied cell density-dependent expression of bpeA-lacZ.
  • Quantified intracellular spermidine and N-acetylspermidine levels in wild-type and mutant strains.
  • Assessed the binding of the BpeR repressor to the bpeABoprB regulatory region in vitro.
  • Measured bpeA-lacZ transcription in vivo with exogenous spermidine and N-acetylspermidine.
  • Investigated the effect of spermidine synthesis inhibition on AHL efflux.

Main Results:

  • BpeAB-OprB effluxes antibiotics and AHLs; its expression is cell density-dependent and inducible.
  • Intracellular spermidine levels increase with cell density and are lower in pump mutants.
  • Spermidine disrupts BpeR repressor binding and activates bpeA-lacZ transcription.
  • Inhibition of spermidine synthesis reduces AHL efflux by BpeAB-OprB.

Conclusions:

  • The BpeAB-OprB pump plays a significant role in spermidine homeostasis in B. pseudomallei.
  • Modulating intracellular spermidine levels affects efflux pump activity.
  • Targeting spermidine synthesis may be a viable therapeutic strategy to reduce antibiotic resistance and virulence factors like motility and biofilm formation.

More Related Videos

Live-Cell Fluorescence Microscopy to Investigate Subcellular Protein Localization and Cell Morphology Changes in Bacteria05:57

Live-Cell Fluorescence Microscopy to Investigate Subcellular Protein Localization and Cell Morphology Changes in Bacteria

Published on: November 23, 2019

Quantification of Violacein in Chromobacterium violaceum and Its Inhibition by Bioactive Compounds07:13

Quantification of Violacein in Chromobacterium violaceum and Its Inhibition by Bioactive Compounds

Published on: August 8, 2025

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...
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...
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...
Gene Regulation During Sporulation01:17

Gene Regulation During Sporulation

Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as...
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...