[Screening and real-time quantitative detection for genomic signatures of Bacillus anthracis]

A total amount of 117 candidate chromosomal sequences were screened for the genomic signatures of Bacillus anthracis by a 2-step approach. Out of them, 19 genomic signatures sequences were selected, among which, 6 genomic signatures were competent as the target sequence of TaqMan real-time PCR method. With the most significant alignment and specificity, fragment C04, together with pagA gene and capB gene from virulence plasmids pX01 and pX02, was selected to establish a TaqMan real-time PCR assay. For each target sequence, as little as 10 to 100 copies per reaction could be detected. Twelve bacterial species including 7 from Bacillus cereus group which were closely related to Bacillus anthracis were used to test the specificity of this assay. Data revealed that the assay gained a 100% specificity. Further performance of the assay was assessed with 10 simulative contaminated environmental samples and 20 negative control environmental samples; all of the Bacillus anthracis contaminated samples gave strong positive signals while the control samples were negative. This specific and sensitive real-time PCR assay could be used in rapid confirmation or exclusion of potential bio-attacks and the diagnosis of anthrax.