Related Experiment Video

Updated: Apr 26, 2026

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
11:32

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Published on: February 23, 2014

14.6K

Spermidine biosynthesis and transport modulate pneumococcal autolysis

Adam J Potter1, James C Paton2

  • 1Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia.

Journal of Bacteriology
|August 6, 2014
PubMed

Insights

Streptococcus pneumoniae synthesizes spermidine, a polyamine crucial for pathogenesis. Spermidine deficiency delays bacterial autolysis by modulating the LytA autolysin, impacting cell wall integrity.

Area of Science:

  • Microbiology
  • Bacterial Pathogenesis
  • Molecular Biology

Background:

  • Polyamines are vital small cationic molecules with significant biological roles.
  • Pathogenic bacteria utilize polyamines in critical pathogenesis functions.
  • Streptococcus pneumoniae causes substantial global morbidity and mortality.

Purpose of the Study:

  • To characterize the polyamine biosynthetic pathway in Streptococcus pneumoniae.
  • To investigate the role of spermidine in S. pneumoniae pathogenesis.
  • To elucidate the mechanism by which spermidine affects bacterial autolysis.

Main Methods:

  • Analysis of the polyamine biosynthetic pathway in S. pneumoniae.
  • Generation and characterization of mutant strains lacking spermidine synthesis or transport.
  • Assessment of bacterial growth and autolysis in defined media.
  • Investigation of spermidine interactions within the pneumococcal cell wall.

Main Results:

  • S. pneumoniae synthesizes spermidine from arginine.
  • Spermidine synthesis is not essential for growth in polyamine-free media.
  • Mutants deficient in spermidine synthesis or transport exhibit delayed autolysis.
  • Spermidine modulates the activity of the autolysin LytA.

Conclusions:

  • Spermidine plays a significant role in Streptococcus pneumoniae pathogenesis.
  • Spermidine influences bacterial autolysis by interacting with cell wall components like teichoic acids.
  • Targeting the spermidine pathway or transport could represent a novel therapeutic strategy against pneumococcal infections.

More Related Videos

Synthesis of Masarimycin, a Small Molecule Inhibitor of Gram-Positive Bacterial Growth09:10

Synthesis of Masarimycin, a Small Molecule Inhibitor of Gram-Positive Bacterial Growth

Published on: January 7, 2022

1.8K
Using the Overlay Assay to Qualitatively Measure Bacterial Production of and Sensitivity to Pneumococcal Bacteriocins06:05

Using the Overlay Assay to Qualitatively Measure Bacterial Production of and Sensitivity to Pneumococcal Bacteriocins

Published on: September 30, 2014

13.2K

Related Concept Videos

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...
707
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,...
943
Inhibitors of Gram-positive Cell Wall Synthesis01:23

Inhibitors of Gram-positive Cell Wall Synthesis

Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...
178
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...
70
Production of Antibiotics01:27

Production of Antibiotics

Penicillin, one of the earliest and most widely used antibiotics, is produced industrially by the filamentous fungus Penicillium chrysogenum. Large stirred-tank bioreactors ranging from tens to hundreds of thousands of liters maintain tightly controlled temperature, pH, and dissolved oxygen conditions to support fungal metabolism and maximize antibiotic yield. Penicillin is a secondary metabolite, synthesized primarily during the stationary growth phase, which requires a carefully managed...
245
Biosynthesis of Nucleic Acids01:28

Biosynthesis of Nucleic Acids

Nucleic acid biosynthesis is a fundamental biochemical process that produces the purine and pyrimidine nucleotides essential for DNA and RNA synthesis. This pathway maintains a balanced nucleotide pool, preventing imbalances that could jeopardize genetic integrity and cellular function. Given the crucial role of nucleotides, their synthesis is tightly regulated to ensure proper cellular homeostasis.Purine BiosynthesisThe biosynthesis of purine nucleotides begins with ribose-5-phosphate, a...
1.7K