Related Experiment Video

Updated: May 31, 2026

Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291
06:51

Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291

Published on: December 10, 2016

Identification of a novel virulence factor in Clostridium difficile that modulates toxin sensitivity of cultured

Masashi Miura1, Haru Kato, Osamu Matsushita

  • 1Department of Foodborne Infection Research (SRL, Inc.), Kitasato University School of Medicine, 1-15-1 Sagamihara-shi, Minami-ku, Kanagawa 252-0374, Japan. miuram@med.kitasato-u.ac.jp

Infection and Immunity
|July 13, 2011
PubMed

Insights

A newly discovered protein, Srl, from Clostridium difficile enhances the harmful effects of toxins A and B. This protein contributes to disease severity by increasing toxin-induced cell damage in intestinal epithelial cells.

Area of Science:

  • Microbiology
  • Cell Biology
  • Pathogenesis

Background:

  • Clostridium difficile infection is a significant cause of antibiotic-associated diarrhea.
  • Toxins A and B are key virulence factors, but other bacterial factors may contribute to disease.
  • The precise mechanisms of C. difficile pathogenesis, particularly the role of minor proteins, are not fully understood.

Purpose of the Study:

  • To investigate the role of minor proteins in C. difficile pathogenesis.
  • To identify novel factors that influence host cell responses to C. difficile toxins.
  • To characterize the function of a previously uncharacterized protein, Srl, in modulating toxin activity.

Main Methods:

  • Analysis of C. difficile culture filtrate to identify factors affecting actin cytoskeleton organization.
  • Characterization of a novel F-actin aggregated structure termed "actin aggregate."
  • Purification and functional analysis of the hypothetical protein Srl, including its effect on cell viability and transepithelial resistance.

Main Results:

  • A previously uncharacterized protein, Srl, was identified in C. difficile culture filtrate.
  • Recombinant Srl induced actin aggregate formation and enhanced the cytotoxicity of toxins A and B.
  • Srl alone did not exhibit cytotoxicity, but it potentiated toxin-induced decreases in cell viability and transepithelial resistance.

Conclusions:

  • Srl is a novel C. difficile factor that enhances the cytotoxicity of toxins A and B.
  • Srl may contribute to the pathogenesis of C. difficile infection by modulating intestinal epithelial cell sensitivity to toxins.
  • Targeting Srl could be a potential therapeutic strategy to reduce C. difficile-associated disease severity.

More Related Videos

A Protocol to Characterize the Morphological Changes of Clostridium difficile in Response to Antibiotic Treatment12:58

A Protocol to Characterize the Morphological Changes of Clostridium difficile in Response to Antibiotic Treatment

Published on: May 25, 2017

Culturing and Maintaining Clostridium difficile in an Anaerobic Environment11:13

Culturing and Maintaining Clostridium difficile in an Anaerobic Environment

Published on: September 14, 2013

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 Toxins01:12

Bacterial Toxins

Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to 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...