PhoX Enzyme Detection for Vibrio Parahaemolyticus Virulence

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods fail to easily distinguish between virulent and non-virulent phenotypes of Vibrio parahaemolyticus strains causing acute hepatopancreatic necrosis disease (AHPND) in shrimp aquaculture, which affects shrimp production and causes significant economic losses.

Innovation Solution

Utilizing alkaline phosphatase PhoX enzyme as a marker to phenotype Vibrio parahaemolyticus as non-virulent by detecting its presence in shrimp culture water, alongside using antibodies or fragments thereof to specifically bind to PhoX enzyme, and optionally detecting PirA VP< and/or PirB VP< toxins, through assays like ELISA.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional detection methods are used to identify Vibrio parahaemolyticus strains, then detection can be performed, but it is difficult to distinguish between virulent and non-virulent phenotypes

Engineering Contradiction:
Improvedetection precisionVSAvoiddifficulty of phenotype differentiation
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent employs colorimetric substrates for alkaline phosphatase that produce visible color changes to differentiate between virulent and non-virulent phenotypes. The assay system uses colorimetric detection where the presence or absence of alkaline phosphatase activity results in distinct color signals, enabling easy visual differentiation of bacterial phenotypes without complex equipment.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The invention detects phenotypic differences by measuring alkaline phosphatase activity levels as a key parameter. By quantifying the enzymatic activity through colorimetric assays, the method transforms the biological phenotype into a measurable physical parameter (enzyme activity), allowing precise distinction between virulent and non-virulent strains based on this biochemical parameter.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If complex detection assays are developed to distinguish virulent from non-virulent strains, then detection precision improves, but device complexity and ease of operation deteriorate

Engineering Contradiction:
Improvephenotype detection precisionVSAvoidassay complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The detection method utilizes the inherent alkaline phosphatase enzyme activity of the bacteria themselves as the detection marker. The bacteria's own metabolic enzymes serve as the diagnostic tool, eliminating the need for external labeling or complex reagent systems. This self-service approach simplifies the assay while maintaining high detection precision for phenotype differentiation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent introduces colorimetric substrates as intermediaries that convert invisible enzymatic activity into visible color signals. These substrate mediators bridge the gap between the biological phenomenon (alkaline phosphatase activity) and the detectable output (color change), simplifying the detection process while maintaining accuracy without requiring complex instrumentation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of time

If phenotype switching is monitored in real-time, then early detection capability improves, but detection time and resource requirements increase

Engineering Contradiction:
Improvedisease detection timeVSAvoiddetection throughput
Core Design Contradiction:
Loss of timeVSProductivity

Solution Approach 1:

The method detects alkaline phosphatase activity directly in culture samples without requiring extensive sample preparation or incubation steps. By using a rapid colorimetric assay that can be performed on relatively simple samples, the system achieves early detection capability while maintaining efficient throughput, as the detection reaction itself is quick and does not require complex pre-processing procedures.

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

Effectively differentiates between virulent and non-virulent Vibrio parahaemolyticus strains, enabling early detection and monitoring of AHPND, thereby reducing disease impact on shrimp populations and associated economic losses.

Implementation Method 1

The present invention discloses that detection of the presence of alkaline phosphatase PhoX enzyme... as a marker to phenotype said Vibrio parahaemolyticus as non-virulent

Methodology Applied
Scientific EffectEnzyme catalysis: Enzyme

Implementation Method 2

usage of molecules which bind to the alkaline phosphatase PhoX enzyme of Vibrio parahaemolyticus (such as in an ELISA/antibody-based assay)

Methodology Applied
Scientific EffectAntigen-antibody binding: Absorption (physical)

Data Source

PatentEP4028770B1Means to detect whether acute hepatopancreatic necrosis disease-causing vibrio parahaemolyticus is virulent or non-virulent
Publication Date: 2025.09.10 UNIV GENT
  • EP4028770B1 patent drawingFigure 1(i)
  • EP4028770B1 patent drawingFigure 1(ii)
  • EP4028770B1 patent drawingFigure 2A~2C

AI summary

The present invention relates to the field of monitoring acute hepatopancreatic necrosis disease in shrimp. More specifically, the present invention discloses that detection of the presence of alkaline phosphatase Phox enzyme, or, of the PiRAvp and/or the PirBvp toxins of acute hepatopancreatic necrosis disease-causing Vibrio parahaemolyticus correlates with non-virulence or virulence, respectively of said bacterium. Hence, a assay capable of detecting said Phox enzyme and/or said toxins could be very useful to monitor said disease in shrimp.