Related Experiment Video

Updated: Oct 2, 2026

Enrichment and Detection of Clostridium perfringens Toxinotypes in Retail Food Samples
08:00

Enrichment and Detection of Clostridium perfringens Toxinotypes in Retail Food Samples

Published on: October 18, 2019

Perfringolysin O expression in Clostridium perfringens is independent of the upstream pfoR gene

Milena M Awad1, Julian I Rood

  • 1Bacterial Pathogenesis Research Group, Department of Microbiology, Monash University, Victoria 3800, Australia.

Journal of Bacteriology
|March 13, 2002
PubMed

Insights

The pfoR gene does not regulate perfringolysin O production in Clostridium perfringens. Studies found no change in perfringolysin O activity when pfoR was mutated or complemented, suggesting pfoR is not involved in pfoA regulation.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Pathogenesis

Background:

  • Clostridium perfringens causes gas gangrene via toxins like perfringolysin O.
  • Previous research suggested the pfoR gene regulates the perfringolysin O gene (pfoA) in E. coli.

Purpose of the Study:

  • To investigate the role of the pfoR gene in regulating perfringolysin O (pfoA) expression in Clostridium perfringens.
  • To confirm or refute the hypothesis that pfoR positively regulates pfoA.

Main Methods:

  • Constructed a pfoR-pfoA deletion mutant in C. perfringens.
  • Complemented the mutant with shuttle plasmids encoding pfoA, with and without pfoR.
  • Created chromosomal pfoR mutants using homologous recombination.

Main Results:

  • Complementing the deletion mutant with plasmids did not alter perfringolysin O production.
  • Chromosomal pfoR mutants showed no difference in perfringolysin O activity compared to wild-type.
  • Perfringolysin O expression remained unchanged despite pfoR mutations.

Conclusions:

  • The pfoR gene product is unlikely to play a role in the regulation of pfoA expression in Clostridium perfringens.
  • The hypothesis of positive regulation of pfoA by pfoR in C. perfringens was not supported by experimental evidence.

More Related Videos

A Purification and In Vitro Activity Assay for a (p)ppGpp Synthetase from Clostridium difficile09:53

A Purification and In Vitro Activity Assay for a (p)ppGpp Synthetase from Clostridium difficile

Published on: November 3, 2018

Generation of In-Frame Gene Deletion Mutants in Pseudomonas aeruginosa and Testing for Virulence Attenuation in a Simple Mouse Model of Infection08:34

Generation of In-Frame Gene Deletion Mutants in Pseudomonas aeruginosa and Testing for Virulence Attenuation in a Simple Mouse Model of Infection

Published on: January 8, 2020

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...
Prokaryotic Transcriptional Activators and Repressors01:58

Prokaryotic Transcriptional Activators and Repressors

The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
Protein Import into the Peroxisomes01:27

Protein Import into the Peroxisomes

Cells contain membrane-bound organelles called peroxisomes that oxidize organic molecules by transferring hydrogen atoms to oxygen, producing hydrogen peroxide. Peroxisomes enzymatically convert the released hydrogen peroxide into water and oxygen.
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
Coordination of Gene Expression Processes in Bacteria01:29

Coordination of Gene Expression Processes in Bacteria

The DNA replication, transcription, and translation processes are intricately coupled in bacteria, allowing efficient gene expression and rapid protein synthesis. While this physical and functional coordination is advantageous, it introduces challenges that bacteria overcome through specific regulatory mechanisms.Coupling of Replication, Transcription, and TranslationThe coupling of replication, transcription, and translation is a hallmark of bacterial gene expression. As the replisome unwinds...
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,...
Repressible Operon: trp Operon01:21

Repressible Operon: trp Operon

The trp operon in Escherichia coli exemplifies a repressible operon. It regulates the synthesis of tryptophan through repressor-mediated transcriptional control and attenuation. This dual regulatory mechanism ensures tryptophan biosynthesis occurs only when needed, conserving cellular resources.Structure of the trp OperonThe trp operon consists of five structural genes (trpE, trpD, trpC, trpB, and trpA) that encode enzymes for tryptophan biosynthesis. These genes are transcribed as a single...