Clustered regularly interspaced short palindromic repeats (CRISPR) site in Bacillus anthracis

OBJECTIVE: To investigate the polymorphism of clustered regularly interspaced short palindromic repeats (CRISPR) in Bacillu santhracis and the application to molecular typing based on the polymorphism of CRISPR in B. anthracis. METHODS: We downloaded the whole genome sequence of 6 B. anthracis strains and extracted the CRISPR sites. We designed the primers of CRISPR sites and amplified the CRISPR fragments in 193 B. anthracis strains by PCR and sequenced these fragments. In order to reveal the polymorphism of CRISPR in B. anthracis, wealigned all the extracted sequences and sequenced results by local blasting. At the same time, we also analyzed the CRISPR sites in B. cereus and B. thuringiensis. RESULTS: We did not find any polymorphism of CRISPR in B. anthracis. CONCLUSION: The molecular typing approach based on CRISPR polymorphism is not suitable for B. anthracis, but it is possible for us to distinguish B. anthracis from B. cereus and B. thuringiensis.