HCV Genotyping Using NS5B Region Sequencing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current HCV genotyping methods, particularly those using the 5'NC region, are not as accurate as sequencing-based assays and face challenges due to the high genetic variability of the hepatitis C virus, leading to inconsistencies in identifying virus types and subtypes, which is crucial for clinical analysis and therapeutic intervention.
Innovation Solution
A method involving the sequencing of the NS5B region of the HCV genome using degenerate oligonucleotide sequencing primers to amplify and determine the genotype, specifically targeting regions from nucleotide positions 8344 to 8547, enabling accurate identification of HCV genotypes and subtypes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sequencing-based assays are used to improve genotyping accuracy, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent segments the HCV genome into specific regions (5'NC region, NS5B region, or other conserved regions) for targeted sequencing. By focusing on specific segments rather than the entire genome, the assay achieves high genotyping accuracy while reducing sequencing complexity and cost. The method allows selection of optimal regions based on conservation levels and genotype differentiation capabilities.
Solution Approach 2:
The patent employs parameter changes by adjusting sequencing parameters such as read depth, coverage thresholds, and alignment stringency to optimize accuracy. It also utilizes phylogenetic analysis parameters and database comparison settings to enhance genotyping precision. These parameter optimizations enable high accuracy without requiring proportionally increased sequencing complexity.
2Adaptability or versatility
If degenerate primers are used to cover multiple HCV species, then adaptability is improved, but measurement precision deteriorates
Solution Approach 1:
The patent employs dynamic primer design where degenerate primers are used for initial amplification to capture diversity, followed by subsequent sequencing and phylogenetic analysis that adapts to the specific genotype identified. This dynamic approach allows the assay to maintain broad adaptability across HCV species while achieving precise genotype identification through computational analysis rather than fixed primer specificity alone.
Solution Approach 2:
The patent introduces computational intermediaries including phylogenetic analysis algorithms and database comparisons as mediators between the degenerate primer amplification and final genotype identification. These computational tools process the sequence data and translate it into accurate genotype assignments, resolving the contradiction between primer universality and identification precision.
3Measurement precision
If high-resolution sequencing is performed to distinguish subtypes, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The patent applies partial action by sequencing only the necessary portions of the HCV genome (such as the 5'NC region or NS5B region) rather than the entire genome. This targeted approach provides sufficient precision for subtype identification while significantly reducing sequencing time and resource requirements. The method identifies the minimum essential region needed for accurate genotyping.
Solution Approach 2:
The patent performs preliminary actions including pre-aligning sequences against reference databases, pre-filtering for quality thresholds, and pre-establishing phylogenetic trees before final genotype assignment. These preliminary computational steps enable rapid subtype identification without requiring extensive real-time analysis, thus reducing overall sequencing time while maintaining high precision.
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 approach improves the accuracy of HCV genotyping by correlating nucleotide sequences with specific genotypes and subtypes, providing a more reliable method for clinical analysis and therapeutic decision-making.
Implementation Method 1
oligonucleotide primers and probes (e.g., PCR amplification primers, sequencing primers, and site-specific probes) that are complementary to and are capable of hybridizing to corresponding nucleic acid sequences of the HCV genome
Implementation Method 2
the HCV RNA-dependent RNA polymerase, which is encoded by the non-structural 5B (NS5B) gene
Data Source
AI summary
The present invention is directed to methods and reagents for determining the genotype of a hepatitis C virus (HCV) species present in a test sample. The invention more particularly relates to mixtures of degenerate amplification and sequencing primers, and methods of using such primers, that are complementary to a plurality of HCV species, and are capable of generating nucleotide sequence information for a region of NS5B of HCV that is, for each species, indicative of the type and/or subtype, of the species present in the sample.