PCR Primer Pairs for E. coli Serotype Differentiation
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Solution Overview
Problem
Current methods for detecting pathogenic Escherichia coli strains, particularly serotypes like E. coli O157:H7, are not sufficiently rapid or effective for differentiating between strains with varying public health implications, posing challenges in food and waterborne outbreak detection and regulation.
Innovation Solution
A PCR-based method using specific primer pairs (SEQ ID NOs:2 and 3, SEQ ID NOs:5 and 6, SEQ ID NOs:8 and 9, SEQ ID NOs:10 and 11, SEQ ID NOs:13 and 14, SEQ ID NOs:16 and 17) for amplification and melting curve analysis to detect pathogenic E. coli, allowing for differentiation of serotypes like O157:H7, O55:H7, O26:H11, and O145:HNM.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional detection methods are used for pathogenic E. coli, then detection capability is maintained, but detection speed and differentiation accuracy are insufficient
Solution Approach 1:
The detection system segments the E. coli differentiation task by targeting specific virulence factor genes (STEC virulence factors) rather than attempting to detect all E. coli strains uniformly. This allows rapid identification of pathogenic strains by focusing on distinctive genetic markers, thereby improving differentiation accuracy while reducing detection time.
Solution Approach 2:
The method changes the detection parameter from general E. coli presence to specific virulence factor gene detection. By using PCR amplification targeting specific genetic sequences (such as eae, stx, and other virulence genes), the system achieves rapid and accurate differentiation of pathogenic strains based on their unique genetic parameters rather than general bacterial presence.
2Productivity
If rapid detection methods are implemented, then detection speed improves, but reliability and accuracy of pathogenic strain identification may compromise
Solution Approach 1:
The detection system applies local quality by targeting specific local regions of the E. coli genome that encode virulence factors. Instead of attempting to detect the entire bacterial genome or all bacterial components, the method focuses on specific genetic loci (such as the eae gene for attaching-effacing properties or stx genes for Shiga toxin production). This localized approach ensures high reliability and accuracy by detecting only the most indicative markers of pathogenicity.
Solution Approach 2:
The method replaces traditional mechanical/biochemical detection methods with molecular genetics-based PCR amplification. This substitution enables rapid detection by directly analyzing genetic material rather than relying on slower cultural or biochemical tests, thereby improving detection speed while maintaining high reliability through specific genetic targeting.
3Adaptability or versatility
If multiple serotypes are differentiated, then public health surveillance capability improves, but test complexity increases
Solution Approach 1:
The detection system achieves universality by using a single PCR-based assay that can differentiate multiple E. coli serotypes and detect various virulence factors simultaneously. The method employs a universal detection platform that can identify different pathogenic strains (O157:H7, O103:H2, O111:HNM, etc.) through detection of their respective virulence factor genes, thereby providing multi-functional serotype differentiation without requiring separate tests for each serotype.
Solution Approach 2:
The method transitions from traditional two-dimensional differentiation (based on O and H antigens requiring complex serological testing) to a molecular dimension by detecting virulence factor genes directly. This dimensional change allows for rapid multi-serotype differentiation by analyzing genetic rather than phenotypic characteristics, thereby reducing test complexity while improving versatility.
4Measurement precision
If specific primer pairs are used for PCR amplification, then detection specificity improves, but the range of detectable serotypes is limited
Solution Approach 1:
The detection system segments the E. coli genome into multiple distinct virulence factor regions, each targeted by specific primer pairs. Instead of using a single universal primer set, the method employs multiple specialized primer pairs (e.g., for eae, stx, and other virulence genes) that can be selectively applied to detect different serotypes and pathogenicity factors, thereby achieving both high specificity and broad serotype coverage.
Solution Approach 2:
The method introduces dynamics by allowing flexible selection and combination of different primer pairs based on the specific detection needs. The system can dynamically adjust which primer pairs are used depending on the suspected serotype or virulence factor of interest, enabling adaptability to different detection scenarios while maintaining high specificity through targeted primer design.
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 enables rapid and accurate detection of pathogenic E. coli serotypes, enhancing public health surveillance and regulatory compliance by identifying specific strains within a sample, even in complex matrices like food and water samples.
Implementation Method 1
performing PCR amplification of the sample using a primer pair selected from the group consisting of (i) SEQ ID NOs:2 and 3, (ii) SEQ ID NOs:5 and 6, (iii) SEQ ID NOs:8 and 9, (iv) SEQ ID NOs:10 and 11, (v) SEQ ID NOs:13 and 14, and (vi) SEQ ID NOs:16 and 17, to produce a PCR amplification result
Implementation Method 2
in step (b) a melting curve analysis is used to detect for amplification product
Data Source
AI summary
Oligonucleotide sequences and methods for specifically detecting and differentiating amongst pathogenic E. coli in a complex sample. The complex sample can be a food sample, water sample, or selectively enriched food matrix. The methods of detection may utilize PCR amplification with, or without, an internal positive control, and appropriate primer pairs. Reagents for performing the methods can be supplied as a kit and/or in tablet form.