Mitis-salivarius (MS) agar has been used widely in microbial epidemiological
studies because oral viridans streptococci can be selectively grown on this medium. Even
though the previous findings reported the limited selecting power of MS agar for streptococcus
strains, the identities of non-streptococcal strains from human oral samples which
can grow on this medium are not clear yet. In this study, we identified non-streptococcal
organisms grown on MS agar plates by polymerase chain reaction (PCR) amplification and
sequencing of the 16S ribosomal RNA (rRNA) gene.