Bacterial genomic DNA was extracted from the strains using Wizard Genomic DNA Purification kit (Promega, Madison, WI). We confirmed the appropriate extraction of the bacterial DNA by PCR using universal primers (Tamura et al., 2005) and P. gingivalis-16S rRNA-specific Everolimus primers (Amano et al., 1999). The PCR amplification was performed in a total volume of 20 μL consisting of PCR Pre-Mix (STD02-M50h; SolGent, Korea), 0.5 μM each primer, and 5 μL of the template DNA solution in sterile distilled water. The amplification reaction was performed in a thermal cycler (Model 9700;

Applied Biosystems, Branchburg, NJ) with the following cycling parameters: an initial denaturation at 95 °C for 5 min, 30 cycles consisting of 94 °C for 30 s, 55 °C for

30 s, and 72 °C for 30 s, and a final extension at 72 °C for 7 min. Positive and negative controls were included in each PCR set and in the processing of all samples. The PCR products were electrophoresed on 1.8% agarose gels. The previous type II primers hybridized to the DNA of P. gingivalis strains harboring type Ib as well as type II fimA, while the new primers specifically amplified only the DNA fragment of type II fimA-P. gingivalis (Table 1). The genotype specificity of the type II (new) primers was further confirmed using the pure culture of strain HG1691 (type Ib) and the mixed culture of strains A7A1-28 (type II) and HG1691. The type Ib primers were used as a positive control. The previous type II primers generated a 257-bp PCR product from the DNA of HG1691, while the new primers did not (Fig. 1a). The sensitivity of the type II and type II (new) primers LGK-974 molecular weight was compared using a decreasing amount (5000–0.5 pg) of A7A1-28 genomic DNA. These two sets of the primers generated PCR products of the expected sizes, 257 and 292-bp, respectively, from as low as 5 pg of the DNA (Fig. 1b). But, the band intensity of the PCR product amplified from 5 pg of the DNA using the new primers, which analyzed using ImageJ (NIH), was 3.14 ± 0.85 (mean ± SD)-fold higher than that amplified using the previous type II primers. Rebamipide Using both the sets of

the primers, we determined the prevalence of type II fimA in the patients with peri-implantitis (PI), which is the destructive inflammatory process affecting the soft and hard tissues surrounding dental implants, as the associated microbiota resembles that found in periodontitis (Becker et al., 1990; Rams et al., 1991). According to an ethically acceptable protocol approved by the IRB Committee of Kyung Hee University School of Dentistry (approval number: KHUSD 1009-02), subgingival plaque samples were taken from 171 Korean adults with PI; two paper points were inserted into the PI pocket for 30 s and then removed and placed in a sterile tube with 1 mL of sterile phosphate buffered saline. Bacterial genomic DNA was extracted from the samples as described earlier.