DNA RESTRICTION-ENDONUCLEASE PROFILES AND TYPING OF GEOGRAPHICALLY DIVERSE ISOLATES OF BACILLUS-LARVAE

DNA isolated from each of 20 Bacillus larvae isolates of geographically diverse origin (17 from Australia, one each from Fiji, Mexico and New Zealand) and cultured on brain heart infusion agar was digested with a range of restriction endonucleases. Based upon the degree of similarity in restriction endonuclease fragment patterns (REFP) produced by the restriction endonuclease Cfo I, five clonal types of B. larvae were identified. REFP were resolved on 3.5% polyacrylamide gels and visualized by silver staining. All the isolates showed many similarities in their REFP, however, those isolates cultured from geographically localized regions showed the greatest similarity. The superior resolving capabilities of polyacrylamide enabled these isolates to be further sub-typed according to minor variations in REFP.