Development of a PCR method for rapid identification of new Streptococcus mutans serotype k strains.
In a previous study, we isolated and characterized a new serotype k of Streptococcus mutans from human blood and oral cavities. Analysis of the genes involved in biosynthesis of the serotype-specific polysaccharide of serotype k strains revealed that the serotype k-specific nucleotide alignment was commonly present in the 5' region of the rgpF gene (350 bp from the initial sequence) compared to the reference strains, and then a method for rapid identification of serotype k strains was developed by use of PCR with primers designed on the basis of the sequence of the variable region. PCR assays with primers specific for amplification of serotype k strains showed a negative reaction with serotype c, e, and f strains and a positive reaction with serotype k strains, with the sensitivity for identification of the serotype k strains shown to range from 5 to 50 cells. Next, the frequency of positive reactions for serotype k-specific primers was surveyed with DNA taken from saliva samples from 200 subjects (2 to 18 years of age), and 10 of those showed a positive reaction, which was higher than the frequency in our previous survey with a serological method. In addition, all saliva samples from subjects with serotype k strains in our previous study were shown to be positive with the serotype k-specific primers. These results indicate that this new PCR method is effective for identification of subjects with S. mutans serotype k.
Nakano
Kazuhiko
K
Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, 1-8 Yamada-oka, Suita, Osaka 565-0871, Japan.
Nomura
Ryota
R
Shimizu
Noriko
N
Nakagawa
Ichiro
I
Hamada
Shigeyuki
S
Ooshima
Takashi
T
D000293:Adolescent; D016470:Bacteremia / Q000382:microbiology; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001769:Blood / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D004697:Endocarditis, Bacterial / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009055:Mouth / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D012463:Saliva / Q000382:microbiology; D012680:Sensitivity and Specificity; D012703:Serotyping; D013290:Streptococcal Infections / Q000382:microbiology*; D013295:Streptococcus mutans / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D013997:Time Factors
D001426:Bacterial Proteins; D011135:Polysaccharides, Bacterial