Species identification of oral viridans streptococci by restriction fragment polymorphism analysis of rRNA genes

J D Rudney, C J Larson
1993 Journal of Clinical Microbiology  
Oral streptococci formerly classified as Streptococcus sanguis have been divided into six genetic groups. Methods to identify those species by genotype are needed. This study compared restriction fragment polymorphisms of rRNA genes (ribotypes) for seven S. gordonii, three S. sanguis, four S. oralis, three S. mitis, one S. crista, and seven S. parasanguis strains classified in previous DNA hybridization studies, as well as one clinical isolate. DNA was digested with HindIH, PvuII, HindIH and
more » ... vuII, HindIH and PvuII combined, EcoRI, BamHI, AatII, AlwNI, and DraII. DNA fragments were hybridized with a digoxigenin-labeled cDNA probe obtained by reverse transcription of Escherichia coli 16S and 23S rRNA. S. oralis, S. mitis, and S. parasanguis all showed an isolated 2,290-bp band in AatII ribotypes that was absent from S. gordonii, S. sanguis, and S. crista. The last three groups showed species-specific bands with AatII and also with PvuH. S. oralis could be distinguished from S. mitis and S. parasanguis in AlwNI and DraH ribotypes. S. mitis and S. parasanguis could not be distinguished, since they shared multiple bands in PvuH, AlwNI, and EcoRI patterns. The clinical isolate in the panel was very similar to S. sanguis by all enzymes used. Our findings suggest that ribotyping may be useful for genotypic identification of oral viridans streptococci. Initial digests of clinical isolates might be made with AatII, followed by PvuII orAlwNI. Isolates then could be identified by comparing ribotype patterns with those of reference strains. This approach could facilitate clinical studies of these newly defined species. 2467
doi:10.1128/jcm.31.9.2467-2473.1993 fatcat:onr3zlgwerdgtg7nnk3lzpxpuu