CAstV Detection via Precapsid-Targeted Oligonucleotides
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Solution Overview
Problem
Current diagnostic methods for detecting chicken astrovirus (CAstV) are limited by the inability to distinguish between different astroviruses, low sensitivity, and the need for gene sequencing, which complicates the detection of CAstV in biological samples due to sequence diversity and the lack of conserved regions for primer design.
Innovation Solution
Development of nucleic acid probes and primers with specificity to the highly conserved 'precapsid' region of the CAstV genome, allowing for sensitive detection using RT-PCR and hybridization assays, with specific primer pairs and probes designed to target this region for broad detection of CAstV sequence variants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional RT-PCR tests use primers targeting the RNA polymerase sequence, then detection can be performed, but the tests cannot distinguish between different avian astroviruses and require gene sequencing for identification
Solution Approach 1:
The invention segments the astrovirus genome into distinct diagnostic regions, using primers that target specific conserved sequences in the capsid protein coding region. This segmentation allows differentiation between CAstV and ANV without requiring full gene sequencing, as each virus type has characteristic sequence patterns in the targeted region.
Solution Approach 2:
The invention applies local quality by designing primers with specific binding characteristics tailored to conserved regions of the capsid protein gene. The primers are designed to bind with high affinity to specific sequences that are conserved across CAstV strains but differ from ANV sequences, enabling local differentiation without analyzing the entire genome.
2Productivity
If electron microscopy is used to detect astroviruses, then virus presence can be demonstrated, but the method lacks sensitivity and is not suited for high sample throughput
Solution Approach 1:
The invention replaces the mechanical imaging system of electron microscopy with a molecular detection system based on RT-PCR. This substitution enables automated, high-throughput processing of multiple samples simultaneously through liquid handling and thermal cycling, while maintaining or improving sensitivity through nucleic acid amplification rather than direct visual detection.
Solution Approach 2:
The invention introduces nucleic acid amplification as an intermediary step between sample collection and detection. By amplifying viral RNA to DNA through RT-PCR, the method creates a detectable signal that can be quantified and differentiated, providing both high sensitivity and the ability to process multiple samples through automated amplification and detection systems.
3Reliability
If antigen-detecting diagnostic tests are developed, then specific virus detection is possible, but no virus-specific antisera are available for CAstVs
Solution Approach 1:
The invention replaces antibody-based antigen detection with nucleic acid-based detection. Instead of requiring virus-specific antisera that are difficult to produce, the method uses PCR primers that can be synthesized chemically and bind to conserved viral RNA sequences. This substitution makes the diagnostic test more manufacturable and accessible, as nucleic acid primers are easier to produce and standardize than animal-derived antisera.
4Measurement precision
If primers are designed to target conserved regions of CAstV, then detection sensitivity is improved, but sequence diversity makes it difficult to identify conserved regions
Solution Approach 1:
The invention performs preliminary sequence analysis and alignment of multiple CAstV isolates to identify conserved regions before designing primers. By pre-characterizing the sequence variability across different strains and laboratories, the invention can design primers that target regions with sufficient conservation across all known CAstV variants, ensuring broad detection capability while maintaining sensitivity.
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 solution enables highly sensitive and universal detection of CAstV, improving diagnostic capabilities and addressing the limitations of existing methods by utilizing primers and probes that bind to a conserved region of the CAstV genome, enhancing detection sensitivity and specificity.
Implementation Method 1
nucleic acid probes and primers with binding specificity to a highly conserved region, herein defined as the 'precapsid' region among different CAstV sequence variants
Implementation Method 2
Reverse Transcriptase Polymerase Chain Reaction (PCR) methodologies to detect enteric viruses in avians
Implementation Method 3
amplifying the reverse transcription products, using a primer pair capable of amplifying a specific amplification product which includes a nucleic acid sequence of or which complements the precapsid region
Data Source
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AI summary
There is provided an oligonucleotide sequence capable of binding to a portion of a CAstV genome, wherein the oligonucleotide sequence has binding specificity to the precapsid region of CAstV or to cDNA of the precapsid region. The oligonucleotide sequence can be one of a primer pair for use in a method for detecting the presence of CAstV in a biological sample by reverse transcription followed by amplification of the reverse transcription products using such primer pair, or a method for amplifying CAstV cDNA using such primer pair.