The Streptococcus anginosus species comprises five 16S rRNA ribogroups with different phenotypic characteristics and clinical relevance

A collection of 267 consecutively isolated Streptococcus anginosus strains was screened for the prevalence of previously described 'motile' strains by hybridization with oligonucleotide probes in a reverse line blot assay. The motile strains represented 101 (37.8%) of the S, anginosus strains. The vast majority of these strains fermented mannitol and raffinose, whereas most other S, anginosus strains did not (P97% sequence similarities), and that most sequence divergences between the ribogroups occurred in the 1024-1064 bp region of the 16S rRNA gene. The present data confirm the heterogeneity within the S, anginosus species.