rRNA gene RFLP as an identification tool for Corynebacterium species

The value of rRNA gene RFLP analysis (ribotyping) as a tool for Corynebacterium and Turicella species identification was evaluated. Seventy-four strains 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 establish a database for species identification. In general, most of the strains belonging to the same species clustered together. Interestingly, BstEII clustering of many species followed known phylogenetic lineages. This was not evident with the more heterogeneous SmaI and SphI patterns. The SmaI patterns contained a 1800 bp band in the digests of all species studied with the exception of Corynebacterium urealyticum. SphI digestion resulted in the most heterogeneous patterns. The information provided by all three enzymes was considered essential for the reliable linking of strains of unknown identity with defined species in the database. It is concluded that ribotyping provides an useful tool for screening and characterization of potentially new Corynebacterium species.