Listeria Detection via Aptamer Capture and Mechanical Lysis
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Solution Overview
Problem
Current methods for detecting Listeria species, particularly Listeria monocytogenes, are not sufficiently rapid or sensitive, especially in environmental samples, leading to delays in food production and potential health risks due to the need for extensive testing and the inability to accurately detect low cell concentrations.
Innovation Solution
A novel bacteria detection kit and method utilizing aptamers for capturing bacterial cells, followed by mechanical lysis and quantitative reverse transcription polymerase chain reaction (qRT-PCR) amplification, specifically targeting conserved ribosomal RNA sequences of Listeria species, which enhances sensitivity and specificity by using oligonucleotides designed to align with RNA ribosome sequences and stabilize probe-target DNA duplexes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional detection methods are used, then the testing process is thorough, but the detection speed is slow and time-consuming
Solution Approach 1:
The patent applies preliminary action by performing mechanical lysis of bacterial cells before the PCR amplification step. This pre-treatment releases nucleic acids in advance, eliminating the need for lengthy cultural enrichment steps used in conventional methods. The result is a direct detection approach that maintains high sensitivity while dramatically reducing detection time from days to hours.
Solution Approach 2:
The patent extracts and directly analyzes nucleic acids from bacterial cells through mechanical lysis, bypassing the need for bacterial cultivation. By taking out the nucleic acid material directly from the sample and using it as template for PCR, the method achieves rapid detection without sacrificing sensitivity, as the amplification process can detect trace amounts of genetic material.
2Measurement precision
If conventional detection methods are used, then the testing is comprehensive, but the ability to detect low cell concentrations is insufficient
Solution Approach 1:
The patent changes the detection parameter from measuring bacterial growth (colony formation) to measuring nucleic acid amplification. By using PCR to amplify specific genetic sequences, the method can detect extremely low cell concentrations (as low as 1-10 cells per sample) because the amplification process generates detectable signals from trace amounts of template DNA, vastly improving detection sensitivity compared to conventional culture methods.
Solution Approach 2:
The patent replaces the biological/mechanical system of bacterial cultivation with a biochemical amplification system. Instead of relying on bacteria to grow and form visible colonies over days, the method uses enzymatic PCR amplification to exponentially increase the amount of target nucleic acid, enabling detection of minute quantities of bacterial material through chemical-biological processes rather than physical growth.
3Loss of time
If rapid detection methods are used, then the detection time is reduced, but the accuracy and reliability decrease
Solution Approach 1:
The patent uses specific oligonucleotide primers and probes as intermediaries that selectively bind to Listeria-specific genetic sequences. These targeted molecular mediators ensure high specificity and accuracy by distinguishing Listeria DNA from other bacterial DNA, even in rapid detection. The use of species-specific genetic markers as intermediaries maintains reliability while enabling fast PCR-based detection without broad-spectrum cultural enrichment.
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 achieves an RNA analytical sensitivity limit of less than 10 fg of Listeria RNA, detecting Listeria at concentrations below 5 CFU/mL without false positives or negatives, significantly improving upon existing commercial kits by being 100-times more sensitive and capable of identifying multiple Listeria species in the presence of non-target RNA.
Implementation Method 1
capturing the bacterial cells using aptamers
Implementation Method 2
lysing the captured bacterial cells
Implementation Method 3
amplifying the bacterial RNA using quantitative reverse transcription polymerase chain reaction (qRT-PCR)
Implementation Method 4
amplification using primers and probe sets with similarity to the L. monocytogenes rnpB gene
Data Source
AI summary
Provided are compositions, kits, and methods for the accurate detection of Listeria. In certain aspects and embodiments, the compositions, kits, and methods may provide improvements in relation to specificity, sensitivity, and speed of detection.