rRNA gene RFLP as an identification tool for Corynebacterium species

The value of rRNA gene RFLP analysis (ribotyping) as a tool for Corynebacte rium and Turicella species identification was evaluated. Seventy-four strai ns representing 26 different species or subspecies were analysed by BstEII, SmaI and SphI ribotyping. Numerical analysis of the resulting rDNA banding patterns was performed by Dice coefficient correlation in order to establi sh a database for species identification. In general, most of the strains b elonging to the same species clustered together. Interestingly, BstEll clus tering of many species followed known phylogenetic lineages. This was not e vident with the more heterogeneous SmaI and SphI patterns. The SmaI pattern s contained a 1800 bp band in the digests of all species studied with the e xception of Corynebacterium urealyticum. SphI digestion resulted in the mos t heterogeneous patterns. The information provided by all three enzymes was considered essential for the reliable linking of strains of unknown identi ty with defined species in the database. It is concluded that ribotyping pr ovides an useful tool for screening and characterization of potentially new Corynebacterium species.