Thermostable Luciferase Assay for Rapid Bactericidal Screening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for screening bactericidal compounds and determining bacterial sensitivity are slow, unreliable, and lack sensitivity, particularly when testing stationary phase or biofilm bacteria, and are prone to artificial ATP release due to physical or chemical stress.
Innovation Solution
A real-time luciferin-luciferase assay using thermostable luciferase measures ATP efflux from live bacteria without physical or chemical stress, allowing rapid detection of bactericidal activity and bacterial sensitivity, applicable to various bacterial strains and forms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional growth inhibition assays are used to screen bactericidal compounds, then the method can detect bacterial growth inhibition, but the test takes many hours (e.g., 20 hours) before a result is obtained
Solution Approach 1:
The patent replaces the mechanical/growth-based detection system (measuring bacterial growth inhibition over time) with a biochemical detection system (measuring ATP release via luciferin-luciferase bioluminescence assay). This substitution allows rapid detection of bactericidal activity within minutes rather than hours, as the biochemical signal is immediately generated when bacteria are killed and release their ATP contents.
Solution Approach 2:
The patent utilizes bioluminescence (light emission) as a detectable signal to monitor bactericidal activity. When bacteria are exposed to bactericidal compounds, cell lysis releases ATP which reacts with luciferin and luciferase to produce light. This optical signal provides real-time, rapid detection of bacterial cell death, eliminating the need for time-consuming growth measurements.
2Measurement precision
If osmotic shock is applied to bacteria to release ATP for detection, then ATP can be measured, but this causes artificial ATP release that skews results and reduces reliability
Solution Approach 1:
The patent applies preliminary anti-action by using gentle handling and isotonic buffer conditions before ATP measurement to prevent artificial cell lysis. The bacteria are treated with bactericidal compounds under controlled conditions, and ATP is measured without subjecting the cells to subsequent osmotic shock or mechanical stress. This preventive approach ensures that any ATP release is truly due to bactericidal activity rather than artificial manipulation.
Solution Approach 2:
The patent uses an intermediary substance (bactericidal compound) that mediates between the bacterial cell and the detection system. The compound causes controlled cell lysis and ATP release in a reversible manner, allowing ATP to be measured without requiring harsh osmotic shock. The intermediary substance enables the detection process while maintaining experimental reliability.
3Adaptability or versatility
If stationary phase or biofilm bacteria are tested, then the method can assess antibiotic efficacy against difficult-to-kill bacteria, but traditional methods cannot reliably detect ATP release from these cells
Solution Approach 1:
The patent creates a universal detection system that works across multiple bacterial forms (planktonic cells, stationary phase cells, biofilm bacteria). The luciferin-luciferase ATP detection method is applicable to all these forms because it directly measures ATP release regardless of the bacteria's growth state or structural organization. This universal approach enables assessment of antibiotic efficacy against the most difficult-to-kill bacterial forms.
Solution Approach 2:
The patent changes the detection parameter from indirect growth measurements to direct ATP concentration measurement. By measuring ATP efflux, the method can detect bacterial cell death in stationary phase and biofilm bacteria that are invisible to traditional growth inhibition assays. This parameter change enables the method to penetrate the limitations of detecting metabolically inactive or encapsulated bacteria.
4Productivity
If large numbers of compounds are screened simultaneously, then high-throughput screening is achieved, but the complexity of the screening system increases
Solution Approach 1:
The patent segments the screening process into discrete, modular components: bacterial sample preparation, compound addition, ATP measurement, and data analysis. This segmentation allows each component to be optimized independently and facilitates automation. The modular design enables high-throughput screening using standard laboratory equipment rather than requiring complex custom systems.
Solution Approach 2:
The patent implements a self-service detection system where the bacteria themselves produce the detection signal through ATP release. The luciferin-luciferase system automatically detects and quantifies ATP efflux without requiring additional reagents, indicators, or complex signal processing. This self-service approach simplifies the screening system while enabling high-throughput analysis of large compound libraries.
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
The method provides rapid, sensitive, and reliable screening of bactericidal compounds and bacterial sensitivity, suitable for large libraries and automated systems, capable of detecting ATP leakage patterns specific to each antibiotic family.
Implementation Method 1
adding a mixture of luciferin and a thermostable luciferase to said test bacterial sample(s); adding a candidate composition to said test bacterial sample(s); and incubating the test bacterial sample(s) to which the mixture of luciferin and thermostable luciferase and the candidate composition have been added at a temperature between 20 and 60° C., preferably between 35 and 37° C. and measuring bioluminescence in real-time
Data Source
AI summary
The present invention relates to a method for screening compounds for bactericidal activity using thermostable luciferase and based on a real-time bioluminescence measurement. The present invention further relates to a method for determining the sensitivity of a bacterial sample originating from a subject suffering from a bacterial infection to a group of known antibiotics and to a method for assessing the minimum inhibitory concentration (MIC) of a bactericidal compound.