Genomic variations in mosquitocidal strains of Bacillus sphaericus detected by M13 DNA fingerprinting

The genomic variation of Bacillus sphaericus reference and local strains belonging to different serotypes was examined by DNA fingerprinting. A phage M13 DNA probe detected a number of variable fragments in the restriction digests of total strain DNAs. The patterns of band distribution showed a certain homology among mosquitocidal strains, expressed by similarity index D and might be a reliable criterion for assessing the level of genomic similarity between closely related strains. An important advantage of DNA fingerprinting is the differentiation of one bacterial strain from another, both expressing common phenotype and possessing highly similar genomic portions. The strain variation revealed by the M13 probe will be useful for characterization of individual strains within a serotype. It could help as well to solve some uncertain cases based on the results obtained by other methods of identification.