A novel dual probe-based method for mutation detection using isothermal amplification.

Area of Science:

• Molecular Biology
• Microbiology
• Genetics

Background:

• Rising multi-drug resistance necessitates cost-efficient and rapid detection tools for mutations.
• Accurate identification of drug resistance mutations is crucial for effective treatment strategies.

Purpose of the Study:

• To develop and evaluate a novel dual-probe isothermal amplification detection system for identifying mutations associated with drug resistance.
• To assess the accuracy of this system in detecting rifampicin resistance mutations in the rpoB gene of Mycobacterium tuberculosis.

Main Methods:

• Integration of a calibrator probe and an indicator probe into an isothermal amplification detection system.
• Design of probes to bind distinct regions on the same amplicon for mutation presence/absence determination.
• Evaluation using 127 artificial samples, clinical MTB strains, and a verification panel to detect rifampicin resistance mutations at rpoB codons 516, 526, and 531.

Main Results:

• The dual-probe method achieved 100% accuracy for wild types and mutants at codons 526 and 531.
• Mutations at codon 516 were identified with 95% accuracy for mutants and 100% for wild types.
• 100% accuracy was observed for wild-type strains using clinical samples and a verification panel, including successful detection of a rifampicin-resistant strain.

Conclusions:

• The dual-probe isothermal mutation detection system is a versatile and accurate approach for nucleic acid testing.
• This method demonstrates significant promise for drug resistance testing, particularly in resource-limited settings.
• The system can identify mutations without prior knowledge of their specific direction, enhancing its applicability.