Expression, purification and cell cytotoxicity of actin-modifying binary toxin from Clostridium difficile

Area of Science:

• Microbiology
• Toxicology
• Molecular Biology

Background:

• Clostridium difficile infection (CDI) poses significant healthcare challenges, causing a spectrum of gastrointestinal illness.
• Virulence in C. difficile is primarily attributed to Toxin A and Toxin B.
• Some strains also produce a binary toxin (CDT), comprising CDTa and CDTb subunits, whose role in CDI pathogenesis remains unclear.

Purpose of the Study:

• To develop methods for expressing and purifying recombinant CDTa and CDTb subunits.
• To investigate the ability of purified CDTa and CDTb to combine and form active CDT.
• To assess the cytotoxicity of the reconstituted CDT.

Main Methods:

• Recombinant expression of CDTa and CDTb in Escherichia coli.
• Purification of individual CDTa and CDTb subunits.
• In vitro combination of purified subunits to form CDT.
• Cytotoxicity assays using Vero cells.

Main Results:

• Successful expression and purification of recombinant CDTa and CDTb were achieved.
• Purified CDTa and CDTb subunits combined to form an active binary toxin.
• The reconstituted CDT exhibited cytotoxicity towards Vero cells.

Conclusions:

• The study provides a method for producing milligram quantities of recombinant CDT subunits.
• This work facilitates further functional and structural studies of the C. difficile binary toxin.
• The findings contribute to understanding the potential role of CDT in CDI pathogenesis.