Isofagomine Inhibits Multiple TcdB Variants and Protects Mice from Clostridioides difficile-Induced Mortality.

Area of Science:

• Microbiology
• Toxicology
• Pharmacology

Background:

• Clostridioides difficile infection (CDI) is a major cause of nosocomial diarrhea.
• Toxins TcdA and TcdB are key virulence factors in CDI pathogenesis.
• Existing therapies require evaluation against emerging toxin variants.

Purpose of the Study:

• To assess the inhibitory efficacy of isofagomine against multiple Clostridioides difficile toxin variants.
• To evaluate isofagomine's protective effects in cellular and murine models of CDI.
• To determine isofagomine's impact on the gastrointestinal microbiota during CDI.

Main Methods:

• In vitro enzymatic assays to evaluate isofagomine inhibition of TcdA and TcdB variants.
• Cell-based assays assessing protection against toxin-induced cell rounding.
• In vivo studies using murine models of C. difficile infection.
• Analysis of gastrointestinal microbiota composition post-treatment.

Main Results:

• Isofagomine demonstrated inhibition of the glucosyltransferase domain across multiple TcdB variants.
• Isofagomine protected cells from TcdB-induced cell rounding.
• Isofagomine significantly reduced mortality in murine models of CDI.
• Treatment with isofagomine facilitated the recovery of the gut microbiota.

Conclusions:

• Isofagomine exhibits broad-spectrum activity against key C. difficile toxins.
• Isofagomine shows potential as a therapeutic or prophylactic agent for CDI.
• Isofagomine's ability to restore gut microbiota may prevent recurrent CDI.