Accurate and sensitive analysis of Staphylococcus aureus through CRISPR-Cas12a based recycling signal amplification cascades for early diagnosis of skin and soft tissue infections.

Early-diagnosis and treatments of skin and soft tissue infections remain a huge challenge due to the difficulties in the detection of trace amounts of bacteria. We develop here a novel method through CRISPR-Cas12a based recycling signal amplification cascades and demonstrated its feasibility of Staphylococcus aureus detection in a sensitive and accurate way. The highlights of the proposed method are calculated as: i) the designed allosteric probe is responsible for accurate identification of SA through PBP2a-specific aptamer; ii) high sensitivity from three processes, including DNA polymerase-based target SA release, Nb.BbvCI enzyme induced ssDNA generation and attached CRISPR-Cas12a. As a result, the proposed method exhibited a detection range from 106 to 102 CFU/ml. Eventually, we believe that the proposed method could be expanded for the construction of diverse sensing platforms for detecting different trace bacteria.