Differentiation ofBacillus anthracisand other âBacillus cereusgroupâ bacteria using IS231-derived sequences

Sequences based on the conserved 20 bp inverted repeat of IS231 variants were used as polymerase chain reaction-based fingerprinting primers of the member species of the Bacillus cereus group (B. anthracis, B. cereus, B. thuringiensis and B. mycoides), because of their close association with transposons, principally Tn4430 in B. thuringiensis. Fingerprints of B. anthracis were simple, and specifically allowed its identification and sub-differentiation from other members of the group. Fingerprints for B. cereus were strain-specific; those for B. thuringensis gave a 1650 bp product, characteristic of IS231 variants A-F. The same reaction conditions gave one or two bands for both B. anthracis and B. cereus that differed by restriction endonuclease mapping from the B. thuringiensis PCR product and established IS231 restriction maps; this does not preclude some kind of relationship between these products and IS231.