Recombinant Bacteriophage Indicator for Rapid Microbial Detection

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Solution Overview

Problem

Current methods for detecting microorganisms, such as bacteria, in samples are slow, requiring several days due to the need for enrichment cultures and are not sufficiently sensitive, especially for detecting low numbers of bacteria.

Innovation Solution

The use of a recombinant indicator bacteriophage with an indicator gene inserted into the bacteriophage genome, which, upon infection of target bacteria, produces a detectable indicator protein complex that can be rapidly detected using a detection reagent and substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional enrichment culture methods are used for microbial detection, then sensitivity is improved, but detection time increases to several days

Engineering Contradiction:
Improvedetection sensitivityVSAvoiddetection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent uses bacteriophages as intermediary agents that specifically infect target bacteria and express indicator proteins. The phages serve as mediators between the sample and detection system, enabling rapid detection without requiring traditional enrichment cultures. The indicator protein expression occurs within minutes of phage infection, dramatically reducing detection time while maintaining sensitivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the detection parameter from bacterial growth-based enrichment (traditional method) to direct indicator protein expression (new method). By using phage-induced protein expression instead of microbial proliferation, the system achieves rapid detection within minutes to hours rather than days, while maintaining the ability to detect low numbers of target bacteria.

Inventive Principle:
Principle #35Parameter changes

2Loss of time

If direct immunoassays or gene probes are used for rapid detection, then detection time is reduced, but sensitivity decreases due to requirement for overnight enrichment

Engineering Contradiction:
Improvedetection timeVSAvoiddetection sensitivity
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The patent employs bacteriophages as intermediary agents that bridge the gap between rapid detection and high sensitivity. The phages specifically bind to and infect target bacteria, then express indicator proteins that can be detected within minutes. This intermediary approach eliminates the need for overnight enrichment while achieving both rapid detection and high sensitivity for low numbers of target bacteria.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical/biological enrichment process (overnight incubation and bacterial growth) with a direct molecular detection system. Instead of relying on bacterial proliferation to amplify the signal, the system uses phage-induced indicator protein expression, substituting a time-consuming biological process with a rapid molecular mechanism that achieves both speed and sensitivity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If PCR tests are used for high sensitivity and selectivity, then detection precision is improved, but the sample size that can be economically tested is limited

Engineering Contradiction:
Improvedetection sensitivityVSAvoidtestable sample size
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent uses bacteriophages as intermediary agents that can be applied to large volumes of samples. Unlike PCR which requires processing individual small samples, the phage-based system can treat entire bulk samples directly. The phages infect target bacteria throughout the sample matrix, and the indicator protein expression can be detected in the bulk, enabling economical testing of large sample sizes while maintaining high sensitivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a universal detection system that works across different sample types and volumes. The phage-based indicator system can be applied to various sample matrices (food, water, clinical samples) and sample sizes without requiring the same level of sample preparation or economic constraint as PCR. The system provides multi-functional capability for rapid, sensitive detection in diverse applications.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Measurement precision

If traditional biological enrichment is used, then detection sensitivity is improved, but the lag time makes identification too slow for public health response

Engineering Contradiction:
Improvedetection sensitivityVSAvoidlag time
Core Design Contradiction:
Measurement precisionVSDuration of action of moving object

Solution Approach 1:

The patent employs bacteriophages as intermediary agents that dramatically reduce the lag time between sample collection and detection. The phages immediately infect target bacteria upon contact, and indicator protein expression begins within minutes. This intermediary mechanism eliminates the hours-to-days lag time of traditional enrichment cultures, enabling rapid public health response while maintaining sensitivity for detecting low numbers of pathogenic bacteria.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent performs preliminary action by pre-equipping the detection system with indicator-expressing phages that are ready to immediately detect target bacteria. Instead of waiting for bacteria to grow and become detectable through traditional enrichment, the system has pre-prepared indicator proteins that are expressed as soon as phage infection occurs. This preliminary preparation of the detection mechanism enables instant response to samples.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method allows for the rapid detection of as few as 10 bacteria in a sample within a significantly shorter timeframe than traditional methods, achieving high sensitivity and specificity without the need for extensive enrichment.

Implementation Method 1

the indicator protein complex is a luciferase

Methodology Applied
Scientific EffectBioluminescence: Bioluminescence

Implementation Method 2

the indicator gene encodes a first peptide or polypeptide subunit of an indicator protein

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP4028540B1Methods and systems for the rapid detection of microorganisms using recombinant infectious agents to express an indicator subunit
Publication Date: 2025.01.29 LABORATORY CORPORATION OF AMERICA HOLDINGS INC
  • EP4028540B1 patent drawingFigure 1
  • EP4028540B1 patent drawingFigure 2
  • EP4028540B1 patent drawingFigure 3

AI summary

Disclosed herein are methods and systems for rapid detection of microorganisms such as bacteria in a sample. A genetically modified bacteriophage is also disclosed which comprises an indicator gene encoding one subunit of an indicator protein. The specificity of the bacteriophage allows detection of a particular bacteria of interest and an indicator signal may be amplified to optimize assay sensitivity.