Related Experiment Video

Updated: Jun 15, 2026

Separation of the Cell Envelope for Gram-negative Bacteria into Inner and Outer Membrane Fractions with Technical Adjustments for Acinetobacter baumannii
10:24

Separation of the Cell Envelope for Gram-negative Bacteria into Inner and Outer Membrane Fractions with Technical Adjustments for Acinetobacter baumannii

Published on: April 10, 2020

Inactivation of phospholipase D diminishes Acinetobacter baumannii pathogenesis

Anna C Jacobs1, Indriati Hood, Kelli L Boyd

  • 1Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-5900, USA.

Infection and Immunity
|March 3, 2010
PubMed

Insights

Acinetobacter baumannii phospholipase D (PLD) is a key virulence factor. Disrupting PLD reduced bacterial growth in serum, invasion of host cells, and disease severity in a pneumonia model.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Bacterial Pathogenesis

Background:

  • Acinetobacter baumannii is a significant healthcare-associated pathogen.
  • Limited knowledge exists regarding its virulence factors and regulatory mechanisms.
  • Severe diseases include septicemia and ventilator-associated pneumonia.

Purpose of the Study:

  • To identify novel virulence factors of Acinetobacter baumannii.
  • To investigate factors contributing to severe disease forms like pneumonia.

Main Methods:

  • Created a transposon mutant library in a serum-resistant A. baumannii strain.
  • Screened the library for mutants with reduced growth in human serum.
  • Evaluated mutant phenotypes for epithelial cell invasion and a murine pneumonia model.

Main Results:

  • Disruption of phospholipase D (PLD) significantly reduced bacterial survival in serum.
  • PLD-deficient mutants showed impaired epithelial cell invasion.
  • Pathogenesis in a murine pneumonia model was diminished in the absence of PLD.

Conclusions:

  • Phospholipase D (PLD) is identified as a crucial virulence factor for Acinetobacter baumannii.
  • PLD contributes to bacterial serum resistance, host cell invasion, and overall disease progression.

More Related Videos

Anti-virulent Disruption of Pathogenic Biofilms using Engineered Quorum-quenching Lactonases07:47

Anti-virulent Disruption of Pathogenic Biofilms using Engineered Quorum-quenching Lactonases

Published on: January 1, 2016

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,...
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...
GPCRs Regulate Adenylyl Cylase Activity01:09

GPCRs Regulate Adenylyl Cylase Activity

Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells.
Two...
Antimicrobial Proteins01:23

Antimicrobial Proteins

Antimicrobial proteins are important components of the immune system. They aid the body in combating pathogens by either killing them directly or hindering their replication processes. Four main types of antimicrobial substances are interferons, the complement system, iron-binding proteins, and antimicrobial proteins.
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
Inhalation Anthrax01:25

Inhalation Anthrax

Anthrax is a zoonotic disease caused by Bacillus anthracis, a Gram-positive, spore-forming bacterium. It primarily affects herbivorous animals but can be transmitted to humans through skin contact, ingestion, or inhalation of spores.Cutaneous anthrax, the most common form, typically results from direct contact with bacterial spores through skin abrasions and is generally less severe. Gastrointestinal anthrax results from eating undercooked or contaminated meat. It affects the mouth, throat, or...
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...