Fighting Shigella by Blocking Its Disease-Causing Toxin

Area of Science:

• Microbiology
• Biochemistry
• Drug Discovery

Background:

• Shiga toxin, produced by Shigella and Shiga toxin-producing Escherichia coli (STEC), causes severe gastrointestinal illness and hemolytic uremic syndrome (HUS).
• Developing effective inhibitors against Shiga toxin is crucial for managing infections and preventing life-threatening complications.

Purpose of the Study:

• To evaluate and compare the efficacy of three classes of carbohydrate-based inhibitors: glycodendrimers, glycopolymers, and oligosaccharides.
• To identify potent inhibitors for Shiga toxin with potential therapeutic applications.

Main Methods:

• Synthesis and characterization of glycodendrimers, glycopolymers, and oligosaccharides.
• In vitro inhibition assays to determine the potency of carbohydrate-based compounds against Shiga toxin.

Main Results:

• Multivalent inhibitors demonstrated enhanced potency, with divalent and tetravalent compounds showing millimolar and micromolar inhibition, respectively.
• A galabiose-based polymeric inhibitor exhibited the highest potency, achieving nanomolar inhibition.
• Alginate and chitosan oligosaccharides also effectively inhibited Shiga toxin.

Conclusions:

• Carbohydrate-based compounds, particularly glycopolymers and specific oligosaccharides, are effective inhibitors of Shiga toxin.
• The identified potent inhibitors, including alginate and chitosan oligosaccharides, hold promise as prophylactic or therapeutic agents against Shigella and STEC infections.