Harnessing multiplex crRNA enables an amplification-free/CRISPR-Cas12a-based diagnostic methodology for Nosema bombycis

Abstract

Nosema bombycis is transmitted horizontally and vertically from infected female moths to progeny eggs, bringing substantial economic losses to sericulture production. Timely and accurate detection of N. bombycis can effectively block the spread of silkworm pébrine disease, which is of great significance for its prevention and control. In this study, we established a multiplex-crRNA CRISPR/Cas12a nucleic acid amplification-free detection method for N. bombycis .. Specificity and sensitivity assessments confirmed that this method specifically detects N. bombycis without cross-reacting with other pathogens. It can detect N. bombycis at levels as low as 2 pg of genomic DNA. This method could also provide information on pathogen quantification, which will be important for in-field applications and promotions. The multiplex-crRNA CRISPR/Cas12a detection method saves hands-on time, reduces the risk of aerosol pollution, and can be directly applied to detecting silkworms infected with Nosema bombycis . This study provides a new approach for the inspection and quarantine of silkworm pébrine disease in sericulture and provides a new method for the detection of other pathogens.