Salmonella Serotyping via Segmented PCR Assay
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Solution Overview
Problem
Current methods for detecting and serotyping Salmonella, particularly Salmonella ser. Enteritidis, are time-consuming and labor-intensive, requiring multiple days to determine serotypes, which delays submission to public health data systems and poses challenges in protecting the food supply.
Innovation Solution
A PCR-based method involving specific primer sets for O-grp-1 and H-ag amplification products, combined with labeled probes for detection, allows for simultaneous detection and serotyping of Salmonella in a multiplex format, enabling rapid identification of Salmonella serotypes, including Salmonella ser. Enteritidis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional Kauffmann-White serotyping methods are used, then comprehensive serotype identification is achieved, but the process becomes time-consuming and labor-intensive, requiring three to five days or more
Solution Approach 1:
The patent segments the complex serotyping process into two distinct stages: a first stage using a panel of antisera for broad serogroup classification, and a second stage using specific antisera for precise serovar identification. This segmentation allows rapid initial classification followed by targeted detailed analysis, reducing overall time while maintaining accuracy.
Solution Approach 2:
The first stage assay performs preliminary serogroup classification using a standardized panel of antisera before committing to the full serotyping process. This preliminary action identifies common serogroups quickly, allowing the system to skip unnecessary second-stage testing for straightforward cases while preparing targeted second-stage reagents in advance for complex cases.
2Measurement precision
If traditional serotyping methods are used, then complete serotype determination is achieved, but production and quality control of multiple antisera becomes difficult and time-consuming
Solution Approach 1:
The patent divides the antisera requirements into two segments: a core panel of antisera for the first stage that covers major serogroups, and a smaller set of specific antisera for the second stage. This segmentation reduces the overall number of antisera that must be produced and controlled, simplifying manufacturing while maintaining comprehensive serotyping capability.
Solution Approach 2:
The first-stage antisera panel is designed with universality to cover multiple serogroups and common serovars, allowing a single reagent to perform multiple classification functions. This multi-functionality reduces the total number of specialized antisera needed, simplifying production and quality control processes.
3Productivity
If rapid detection methods are implemented, then time to submission is reduced, but detection sensitivity and accuracy may be compromised
Solution Approach 1:
The patent implements a segmented detection approach where the first stage provides rapid screening with high throughput, and the second stage provides confirmatory analysis with high specificity. This segmentation allows the system to achieve both speed and accuracy by optimizing each stage for its specific purpose rather than compromising either.
Solution Approach 2:
The two-stage system incorporates feedback mechanisms where first-stage results inform second-stage testing decisions. Positive first-stage results trigger targeted second-stage confirmation, while negative or ambiguous results initiate appropriate follow-up protocols. This feedback loop ensures rapid processing of clear cases while maintaining accuracy through confirmation of uncertain cases.
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 provides a rapid, sensitive, and reliable detection system for Salmonella serotypes, significantly reducing the time required for serotyping and improving the accuracy of identifying Salmonella in samples, thus enhancing food safety and public health data reporting.
Implementation Method 1
each of the first stage primer sets includes a forward primer that hybridizes to a region flanking a respective target sequence under conditions suitable for a polymerase chain reaction, and a reverse primer that hybridizes to a different region of the target sequence under conditions suitable for a polymerase chain reaction
Implementation Method 2
detecting the presence or absence of each of the amplification products by hybridization to a labeled probe specific to the O-grp-1 amplification product or the H-ag amplification product
Data Source
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AI summary
Processes for the serotype specific detection and identification of one or more Salmonella serotypes are provided. A family of specific primers and probes are provided that allow screening of biological or environmental samples for robust, rapid, and reproducible detection and identification of one or more Salmonella serotypes in the sample.