Background/objectives: Lyme disease diagnosis remains challenging due to the limitations of current methods. While PCR-based assays are widely used, their sensitivity can be affected by sample type and the inhibition of host DNA. This study aimed to evaluate the feasibility and sensitivity of a CRISPR/Cas12-based detection system for Borrelia burgdorferi sensu lato, comparing its performance with real-time PCR.
Methods: DNA from three Borrelia genospecies (B. burgdorferi, B. garinii, and B. afzelii) was amplified targeting the OspA gene. Detection was performed using a Cas12/crRNA system with a fluorescent ssDNA reporter. Sensitivity assays were conducted on serial dilutions of Borrelia DNA, with and without human genomic DNA, and results were compared with qPCR.
Results: Direct detection of Borrelia DNA without amplification was not feasible. However, when combined with PCR, the Cas12/crRNA system reliably detected as few as 5 genome copies per reaction. End-point PCR extended to 60 cycles improved detection robustness for B. garinii and B. afzelii, although sensitivity decreased in the presence of human genomic DNA.
Conclusions: The Cas12/crRNA-based system offers a sensitive and accessible alternative to qPCR, especially in settings lacking real-time PCR instrumentation. Future developments may include integration with isothermal amplification and microfluidic platforms to enhance direct detection capabilities.
Keywords: Borrelia; Cas12; Lyme disease; PCR; detection.