IDENTIFICATION OF CLINICALLY RELEVANT VIRIDANS GROUP STREPTOCOCCI TO THE SPECIES LEVEL BY PCR

A PCR assay that allows identification of clinically relevant viridans group streptococci (Streptococcus gordonii, S. mitis, S, mutans, S, o ralis, S, salivarius, and S. sanguis) to the species level and identif ication of milleri group streptococci (S, anginosus, S, constellatus, and S, intermedius) to the group level was developed. This assay was b ased on specific amplification of internal fragments of genes encoding D-alanine:D-alanine ligases which are species specific and ubiquitous in prokaryotes possessing peptidoglycan. The specificity of this assa y was tested on 9 reference strains and 91 characterized clinical isol ates, This assay offers a specific and rapid alternative to phenotypic or DNA-DNA hybridization methods for identification of clinically rel evant viridans group streptococci.