Differentiation among strains and serotypes of Bacillus thuringiensis by M13 DNA fingerprinting

Abstract

The inter- and intraserotypic variations of Bacillus thuringiensis were studied by M13 DNA fingerprinting. Strain-specific patterns were obtained. The degree of homology was evaluated on the basis of pairwise comparisons and calculation of similarity indexes. Some strains belonging to the same serotype showed highly similar patterns, but others differed significantly. A high degree of polymorphism was established among the serotypes. These results provide evidence that the classification of B. thuringiensis strains on the basis of flagellar antigens does not always adequately reflect their genetic relatedness. DNA fingerprinting could help in future numerical taxonomic analysis of this species.