• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.684-695
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• 2003

The aim of this study was to investigate the effect of composite resin components on proliferation and glucan synthesis by cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus. Light curing pit and fissure sealant was chosen for evluation. Specimens were eluted in deionized water for 10 minutes, 1, 12, and 24 hours. Extracts of specimens were diluted into 1/2, 1/4, and 1/8 with addition of BHI broth and BHI-YS. Bacteria were cultured in media included eluted components, and measured optical density($A_{600}$). The following results were obtained 1. 1/4 concentration of elutes for 10 minutes significantly inhibited the proliferation of S. mutans, whereas 1/2, 1/8 concentration of elutes stimulated it. Also, exacts, especially 1/2, 1/4 concentration, for 1 hours stimulated it. But exacts for 12, 24 hours had not effects on the proliferation of S. mutans. 2. 1/4 concentration of elutes for 10 minutes inhibited growth of S. sobrinus, whereas extracts for 1, 12, 24 hours had not effects on the proliferation of S. sobrinuss. 3. Extracts from composite resin stimulated total growth of S. mutans more than growth control group, where as inhibited it of S. sobrinus. 4. Extracts from composite resin, especially 1/4 concentration of it for 10 minutes increased the formation of water insoluble glucan of S. mutans. But elutes for 1, 12, 24 hours, and 1/8 concentration of it for 10 minutes inhibited it. 5. Except 1/4 concentration of elutes for 10 minutes, extracts decreased the formation of water insoluble glucan of S. sobrinus. 6. Total amount of formated glucan was 3-fold higher in S. mutans than in S. sobrinus.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.1-11
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• 2009

Essential oils are mixture of volatile, lipophilic compounds originating from plants. Essential oils have potential biological effects, i.e., antibacterial, antifungal, spasmolytic and antiplasmodial activities and insect-repellent property. In this study, five essential oils, namely R, LG, FR, O, and NM, extracted from various aromatic plants were used to test their antimicrobial activity against the oral microorganisms. The effects of essential oils were investigated against eight important bacteria, Streptococcus mutans (S. mutans), Staphylococcus aureus (S. aureus), Streptococcus sanguis (S. sanguis), Streptococcus anginosus (S. anginosus), Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans), Streptococcus sobrinus (S. sobrinus), Staphylococcus epidermidis (S. epidermidis), and Escherichia coli (E. coli). Essential oils, except NM, effectively inhibited the growth of tested oral pathogenic microorganisms dose-dependently. However, the essential oils didn't show a significant inhibitory effect against E. coli and S. epidermidis. Consequently, these results represented that essential oil-mediated anti-microbial activity was prominent against the oral pathogenic bacteria. For example, minimum bactericidal concentration(MBC) of R, LG, FR oil against A. actinomycetemcomitans was very low as 0.078 mg/mL. In addition, minimum inhibitory concentration (MIC) of R, LG, FR, O oil against S. mutans was low as 0.156 mg/mL in vitro.

• Korean Journal of Plant Resources
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• v.23 no.5
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• pp.436-444
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• 2010

Methanol extracts of the aerial and rhizome parts obtained from ten species of ferns has been screened for antimicrobial activities against Bacillus subtilis, Escherichia coli, Listeria monocytogenes, Propionibacterium acnes, Streptococcus mutans and Streptococcus sobrinus. Antimicrobial activities were carried out using broth microdilution method and paper disc diffusion assay and the extracts which showed clear zones more than 15mm in concentration of 2 mg/disc were tested for its antimicrobial activities at the $0.125{\sim}2\;mg{\cdot}mL^{-1}$ concentration of each extract for three days. The non-sterilized crude methanol extracts of Osmunda cinnamomea var. fokiensis rhizome showed the highest antimicrobial activities on B. subtilis(39%), E. coli (33%) and L. monocytogenes(58%) at the concentration of $2\;mg{\cdot}mL^{-1}$ after 72 hours. In P. acnes, frond extract of O. cinnamomea var. fokiensis showed most vigorous antimicrobial activities in the all extracts but it showed weak activity(clear zone diameters below 15 mm). All extracts has the antimicrobial activities on Streptococcus, but they exhibited weak activity. At the concentration of $2\;mg{\cdot}mL^{-1}$, only Osmunda japonica rhizome extracts showed 28 and 39% of antimicrobial activities on S. mutans and S. sobrinus after 72 hours and the other extracts showed below 10% of antimicrobial activities on S. mutans and S. sobrinus.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.239-242
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• 2002

We have synthesized branched oligosaccharides (BOS) by the mixed-culture fermentation (MBOS), fructosyltransferase (FBOS) or glucosyltransferase (GBOS) with high concentration of sucrose (3M). MBOS was further modified as iron and sulfate-oligosaccharides. The modified MBOS were stable at high temperatures (up to $140^{\circ}C$) and low pHs (2 to 4). Most highly branched and modified oligosaccharide (0.34%, w/v) effectively inhibited fructose release from sucrose by Streptococcus mutans 6715 mutansucrase. FBOS, GBOS, iron-MBOS inhibited the mutansucrase activities from Streptococcus sobrinus about 46.8%, 49.2% and 43.1%, respectively. Most highly branched and modified oligo- saccharides (0.5%, w/v) effectively inhibited the fonnation of insoluble glucan and adherence of S. mutans or S. sobrinus cell in the presence of sucrose. Modified oligosaccharides affected the growth and acid production of oral pathogens. Cytotoxicity test showed that highly branched and modified oligosaccharides was non-toxic.

• International Journal of Oral Biology
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• v.35 no.4
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• pp.191-195
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• 2010

Oleanolic acid is a natural triterpenoid that exists widely in foods and some medicinal herbs. The purpose of this study was to determine the antimicrobial activity of oleanolic acid against Streptococcus mutans strains isolated from a Korean population. Antimicrobial activity against these bacteria was evaluated by minimal inhibitory concentration (MIC) and time kill curves. The tolerance of human gingival fibroblasts and human periodontal ligaments to oleanolic acid was tested using a methyl thiazolyl tetrazolium (MTT) assay. The $MIC_{90}$ value of oleanolic acid for both S. mutans and S. sobrinus isolated from Koreans was 8 ${\mu}g/ml$. Oleanolic acid showed bactericidal effects against S. mutans ATCC $25175^T$ and S. sobrinus ATCC $33478^T$ at $1\;{\times}\;MIC$ ($8{\mu}g/ml$) and had no cytotoxic effects against KB cells at this dose. The results suggest that oleanolic acid could be useful in the future development of oral hygiene products for the prevention of dental caries.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.462-469
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• 2004

The aim of this study was to investigate the susceptibility of mutans streptococci (S. mutans and S. sobrinus) and Streptococcus anginosus, for seven antibiotics, penicillin G, amoxicillin, ciprofloxacin, cefuroxime, erythromycin, bacitracin, and vancomycin. The minimum inhibitory concentration (MIC) of seven antibiotics against 3 species (type strains) of mutans streptococci and S. anginosus, 10 strains (wild type) of S. mutans, 7 strains (wild type) of S. sobrinus, and 11 strains (wild type) of S. anginosus, were measured by broth dilution method. All of the type strains of mutans streptococci and S. anginosus had the same susceptibility for penicillin G, amoxicillin, cefuroxime and bacitracin. Type strain of S. anginosus was sensitive in ciprofloxacin, but those of mutans streptococci were not. All of the clinical isolates of mutans streptococci and S. anginosus had the same susceptibility for the seven antibiotics. Our data reveal that mutans streptococci and S. anginosus have similar antibiotic-resistant character. In addition. these results may offer the basic data to verify the antibiotic-resistant mechanism of mutans streptococci and S. anginosus.

• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.484-486
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• 2006

Maltosyl (G2)-mannitol, produced by the transglycosylation of mannitol with maltotriose by Bacillus stearothermophilus maltogenic amylase, was not found to support lactic acid production by Streptococcus sobrinus NRRL 14555. Furthermore, the synthesis of water-insoluble glucans from maltosyl-mannitol by S. sobrinus NRRL 14555 was much lower than that from xylitol or mannitol. Consequently, these results suggest that maltosyl-mannitol could be used as a noncariogenic sugar substitute in food products.

• International Journal of Oral Biology
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• v.36 no.1
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• pp.7-11
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• 2011

Ursolic acid is a triterpenoid compound present in many plants. This study examined the antimicrobial activity of ursolic acid against mutans streptococci (MS) isolated from the Korean population. The antimicrobial activity was evaluated by the minimum inhibitory concentration (MIC) and time kill curves of MS. The cytotoxicity of ursolic acid against KB cells was tested using an MTT assay. The $MIC_{90}$ values of ursolic acid for Streptococcus mutans and Streptococcus sobrinus isolated from the Korean population were $2 {\mu}g$/ml and $4 {\mu}g$/ml, respectively. Ursolic acid had a bactericidal effect on S. mutans ATCC $25175^T$ and S. sobrinus ATCC $33478^T$ at > $2 \;{\times}\; MIC (4 {\mu}g$/ml) and $4 \;{\times}\; MIC (8 {\mu}g$/ml), respectively. Ursolic acid had no cytotoxic effect on KB cells at concentrations at which it exerted antimicrobial effects. The results suggest that ursolic acid can be used in the development of oral hygiene products for the prevention of dental caries.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.90-97
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• 2000

There are various kinds of factors associated with the formation of dental plaque in oral cavity such as nutrient molecules and chemical agents. The factors influencing the formation of insoluble glucan by Streptococcus sobrinus and its replication were examined on orthodontic wires. The results were as follows: 1. Insoluble glucan was well produced in the media initially adjusted at pH 7.0 than pH 5.5 or pH 8.5 like bacterial replication. 2. The synthesis of insoluble glucan and bacterial replication were significantly increased in the media containing 2.5% yeast extract. The formation of insoluble glucan was inhibited by 10 folds in the media containing 20% of sucrose than 1.25%, but the replication of bacteria was increased by 20 folds. 3. Insoluble glucan was significantly formed at a concentration of 1.0mM of calcium chloride, 40mM of potassium chloride, 0.1mM of magnesium chloride, while the replication of bacteria was little influenced by them regardless their concentration. 4. The formation of insoluble glucan and bacterial replication were significant in the media containing 10mM of sodium bicarbonate, but both were completely inhibited at 100mM or above. The production of insoluble glucan and the bacterial replication were largely decreased at 10mM of Tris while insoluble glucan was formed in abundance at 100mM of Tris. 5. The synthesis of insoluble glucan and the bacterial replication were inhibited at 10mM or above of sodium phosphate and potassium phosphate.

• The korean journal of orthodontics
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• v.35 no.4 s.111
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• pp.312-319
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• 2005

Streptococcus mutans and Streptococcus sobrinus are major etiological agents in enamel demineralization around orthodontic appliances. This study was designed to examine the prevalence of these streptococci on orthodontic brackets in vivo using polymerase chain reaction. Four incisor brackets in the upper and lower arches were removed and collected from 80 patients at the time of debonding. The genomic DMA of adhered bacteria was extracted and each dextranase gene of S. mutans and S. sobrinus was amplified using the specific oligonucleotide primers. The results showed that the maxillary incisor brackets were colonized by both cariogenic streptococci to a somewhat higher degree than that taken from the mandible. The prevalence of S. mutans was $50.0\%$ on the maxillary incisor brackets and $33.8\%$ on the mandibular incisor brackets, and that of S. sobrinus was $17.5\%$ and $15.0\%$, respectively. Both species were detected on the maxillary incisor brackets of 7 patients $(8.8\%)$ and the mandibular incisor brackets of 5 patients $(6.3\%)$. These results suggest that cariogenic streptococci can adhere to the incisor brackets and may be resident species on the incisor brackets.