Clinical Avirulent C. difficile Strains Using cdtR Mutations

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Clostridioides difficile infections vary in severity due to strain virulence differences, with ST1 strains being particularly challenging due to high toxin production and antibiotic resistance, necessitating improved methods to reduce virulence and treat associated intestinal disorders.

Innovation Solution

Mutations in the cdtR gene, such as a 69-base pair deletion, reduce or eliminate the virulence of C. difficile strains by attenuating toxin expression, allowing for the use of engineered avirulent strains or bacteriophages encoding mutant cdtR to treat or prevent infections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wildtype virulent C. difficile strains are used, then high toxin production and antibiotic resistance are achieved, but virulence and disease severity increase

Engineering Contradiction:

Improveantibiotic resistanceVSAvoidvirulence

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful virulence factor (cdtR gene) into a benefit by creating a mutant version that provides therapeutic protection. The cdtR mutant strain, while lacking full virulence, colonizes the gut and protects against wildtype infection, transforming the harmful pathogen into a protective agent.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the genetic parameter of the C. difficile strain by introducing mutations in the cdtR gene. This genetic modification alters the strain's virulence parameters while maintaining colonization capability, creating a therapeutic strain with modified properties.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If cdtR mutant strains are administered, then protection against wildtype infection is achieved, but colonization capability must be maintained

Engineering Contradiction:

Improveprotection efficacyVSAvoidcolonization

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by making specific targeted mutations only in the cdtR gene while leaving the rest of the genome intact. This localized genetic modification preserves the strain's ability to colonize the gut while specifically reducing virulence factors, maintaining beneficial properties while eliminating harmful ones.

Inventive Principle:

Principle #3Local quality

3Object-generated harmful factors

If ST1 strains are targeted, then high toxin production is addressed, but antibiotic resistance increases treatment difficulty

Engineering Contradiction:

Improvetoxin productionVSAvoidtreatment complexity

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent extracts the problematic cdtR gene function from the ST1 strain by creating a mutant version. This extraction removes the high toxin production capability while retaining other strain characteristics, isolating the harmful element for modification while preserving the rest of the strain's properties.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS20250325599A1A clinical isolated avirulent strain protects against wildtype virulent clostridioides difficile infection

Publication Date: 2025.10.23 UNIVERSITY OF CHICAGO

AI summary

Aspects herein concern cdtR mutations that can lead to reduced or absent virulence in C. difficile bacteria. Disclosed are compositions and methods using the cdtR mutants to treat or prevent C. difficile infections or diseases caused by C. difficile. Also disclosed are methods for detecting or determining C. difficile virulence based on mutation status of the cdtR gene in C. difficile.