Jae-Yoon Park

Development of Porphyromonas gingivalis-specific quantitative real-time PCR primers based on the nucleotide sequence of rpoB

Species-specific quantitative real-time PCR (qPCR) primers were developed for the detection of Porphyromonas gingivalis. These primers, Pg-F/Pg-R, were designed based on the nucleotide sequences of RNA polymerase β-subunit gene (rpoB). Species-specific amplicons were obtained from the tested P. gingivalis strains but not in any of the other strains (46 strains of 46 species). The qPCR primers could detect as little as 4 fg of P. gingivalis chromosomal DNA. These findings suggest that these qPCR primers are suitable for applications in epidemiological studies.

Bacterial model system for screening and determining optimal concentration of anti-caries natural extracts

In general, an antimicrobial test for screening anti-caries natural extracts was performed by measuring the minimum bactericidal concentration (MBC) against the type strains of mutans streptococci. However, it is unclear if the antimicrobial efficiency of natural extracts on the type strains of mutans streptococci is the same on the clinical strains. In this study, we introduced a bacterial model system for the screening of anti-caries and determining the optimal concentration of them to develop oral hygiene products for Korean populations.

Development of Prevotella intermedia-specific PCR primers based on the nucleotide sequences of a DNA probe Pig27

The aim of this study was to develop Prevotella intermedia-specific PCR primers based on the P. intermedia-specific DNA probe. The P. intermedia-specific DNA probe was screened by inverted dot blot hybridization and confirmed by Southern blot hybridization. The nucleotide sequences of the species-specific DNA probes were determined using a chain termination method. Southern blot analysis showed that the DNA probe, Pig27, detected only the genomic DNA of P. intermedia strains. PCR showed that the PCR primers, Pin-F1/Pin-R1, had species-specificity for P. intermedia. The detection limits of the PCR primer sets were 0.4pg of the purified genomic DNA of P. intermedia ATCC 49046. These results suggest that the PCR primers, Pin-F1/Pin-R1, could be useful in the detection of P. intermedia as well as in the development of a PCR kit in epidemiological studies related to periodontal diseases.

Development of species-specific polymerase chain reaction primers for detection of Fusobacterium periodonticum

The purpose of this study was to develop species‐specific PCR primers for detection of Fusobacterium periodonticum. The specificity data showed that two sets of PCR primers, Fp‐F3/Fp‐R2 and Fp‐F1/Fp‐R2 PCR, produced amplicons from all the F. periodonticum, but not from the other species tested, which included 12 Fusobacterium species or subspecies and representative oral bacteria. The sensitivity of the primer sets was 4 or 40 pg of the chromosomal DNA from F. periodonticum ATCC 33693T. These results suggest that these two sets of PCR primers are quite sensitive in detection of F. periodonticum in molecular epidemiological studies of periodontitis.

Development of Prevotella nigrescens-specific PCR primers based on the nucleotide sequence of a Pn23 DNA probe

A previous study reported the cloning of a putative Prevotella nigrescens-specific DNA probe, Pn23, using random shotgun method. The present study evaluated the species-specificity of Pn23 for P. nigrescens using the clinical strains of Prevotella intermedia and P. nigrescens to develop P. nigrescens-specific polymerase chain reaction (PCR) primers. Southern blot analysis showed that the DNA probe, Pn23, detected only the genomic DNA of P. nigrescens strains. PCR showed that the two sets of PCR primers, Pn23-F1/Pn23-R1 and Pn23-F2/Pn23-R2, had species-specificity for P. nigrescens. Interestingly, the two sets of PCR primers, Pn23-F6/Pn23-R6 and Pn23-F7/Pn23-R7, had strain-specificity for P. nigrescens ATCC 33563. The detection limits of the four primer sets were 40 or 4 pg of the purified genomic DNA of P. nigrescens ATCC 33563. These results suggest that the DNA probe, Pn23, and the two sets of PCR primers, Pn23-F1/Pn23-R1 and Pn23-F2/Pn23-R2, can be useful for the detection of P. nigrescens in the molecular epidemiological studies of oral infectious diseases.