[Development of an identification method for Streptococcus oligofermentans: a new species of oral streptococci with molecular markers].
OBJECTIVE
To establish a quick and reliable method to identify Streptococcus oligofermentans, a new species of oral streptococci.


METHODS
With two-step PCR, a pair of the 16S rDNA-specific primers of Streptococcus oligofermentans and a pair of primers of lactate oxidase gene (lox) were used to amplify the gene fragments from the genomic DNAs of 11 strains consisting of 9 species of the pure culture of oral streptococci. Pooled plaque samples from 9 caries-free volunteers were cultured on a selective medium of MSA with erythromycin and tentative strains of Streptococcus oligofermentans were isolated. The isolates were further identified by the two-step PCR and finally confirmed by 16S rDNA sequence analysis.


RESULTS
With the two-step PCR, the two gene fragments were only amplified from the three identified strains of Streptococcus oligofermentans, but not the rest of 8 strains of oral streptococci. Isolates from the dental plaque of caries-free volunteers were identified as Streptococcus oligofermentans by PCR and then further confirmed by 16S rDNA sequence homology analysis.


CONCLUSIONS
Streptococcus oligofermentans could be identified by the two-step PCR approach with the specific 16S rDNA primers and lactate oxidase gene primers.
Zhang
Jie
J
Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
Tong
Hui-chun
HC
Dong
Xiu-zhu
XZ
Yue
Lin
L
Gao
Xue-jun
XJ
D015373:Bacterial Typing Techniques / Q000379:methods*; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D006899:Mixed Function Oxygenases / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013291:Streptococcus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*
D017931:DNA Primers; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D006899:Mixed Function Oxygenases; C021497:lactate 2-monooxygenase