crRNA array-mediated CRISPR/Cas12a coupling with dual RPA for highly sensitive detection of Streptomyces aureofaciens...

Accurate and sensitive detection of Streptomyces aureofaciens Tü117 is crucial for hypertension classification and early warning. To achieve this, a dual recombinase polymerase amplification coupled with a crRNA array-mediated CRISPR/Cas12a assay (DR-CAMCas) was developed, enabling multi-signal output for precise identification and detection of S. aureofaciens Tü117. The 16S rDNA and LipReg4 genes of S. aureofaciens Tü117 are amplified simultaneously via one-step dual RPA, activating the crRNA array-mediated CRISPR/Cas12a system to cleave exogenous FQ-reporters, releasing fluorescent signals. DR-CAMCas offers high amplification efficiency, multi-site recognition through crRNA array signal superposition, and the programmability of CRISPR/Cas12a, achieving ultrasensitive detection with a linear range of 10 to 10⁸ cfu/mL and a limit of detection of approximately 3 cfu/mL. DR-CAMCas successfully detected S. aureofaciens Tü117 in fecal samples from high-salt diet-induced hypertensive mice and hypertensive patients, matching qPCR results and demonstrating high reliability and practicality. Additionally, target-induced cleavage of a DNA linker by DR-CAMCas dispersed AuNPs-DNA probes, enabling colorimetric detection. Integrated onto lateral flow sensors, DR-CAMCas allows point-of-care testing via simple visual strip analysis. Its triple signal output meets diverse detection needs, offering a promising tool for diagnosing salt-sensitive hypertension.