• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.207-216
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• 2005

Mutans streptococci have been reported to be implicated in dental caries. Of these streptococcal species, Streptococcus mutans and Streptococcus sobrinus are most commonly found in human dental caries. Prevalence of these bacterial species in dental caries is found to be varied in different races and countries. Therefore, importance of these bacteria in dental caries remains to be determined. The present study was peformed to detect S. mutans and S. sobrinus in 52 Korean children with dental caries between 2 to 6 years of age. For the study, plaque samples were collected from caries-active(CA) and caries-free(CF) teeth of each subject. DNA was extracted from the plaques and amplified by polymerase chain reaction(PCR) using primers corresponding to dex and gtf genes. The results obtained from the study were as follows: 1. Of 52 children, 37 children (71.2%) were found to harbor S. mutans and/or S. sobrinus. 2. Of the MS-infected 37 children, 3 children (5.8%) harbored S. mutans and/or S. sobrinus in the CF plaques only, 22 children (42.3%) in the CA plaques only and 12 children (23.1%) in both CF and CA plaques. 3. S mutans and/or S. sobrinus were detected in 34 CA plaques (65.4%), while 15 in CF plaques (28.8%) 4. In the case of CF plaques, 8 plaques (15.4%) were observed to harbor S. mutans only, 6 plaques (11.5%) to harbor S. sobrinus only and 1 plaque (1.9%) to harbor both species. 5. Of CA plaques, 24 plaques (46.2%) were detected to have S. mutans only, 2 plaques (3.8%) to have S. sobrinus only and 8 plaques (15.4%) to have both species. 6. In comparison with the efficiency of two different primers for PCR, it was found that the primer based on gtf gene was more effective in detecting S. mutans, while the primer corresponding to dex gene was better for S. sobrinus. Overall results suggest that MS appears to be important in dental caries of the Korean children, and S. mutans is more closely associated with than dental caries as compared to S. sobrinus.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.4
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• pp.587-596
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• 2006

Most of oral streptococci express the Antigen I/II (AgI/II) proteins, cell wall anchored adhesions. AgI/II protein binds to salivary agglutinin glycoprotein, a component of tooth pellicle and to ligands in other bacteria. These associations play important roles in bacterial colonization. Recently, it was reported that diverse host molecules also interact with AgI/II protein and that these interactions induce inflammatory responses from host cells. Among mutans streptococci containing -type hemolytic activity, Streptococcus mutans is a causative agent for dental caries. Compared with many other strains of S. mutans, GS-5 strain is unique in that this bacterium expresses truncated secretory AgI/II protein due to the nonsense mutation in the agI/II gene. This indicates that S. mutans GS-5 has a different clinical role and a recent report supported this idea based on the results from clinically isolated S. mutans strains. Previously, we had cloned agI/II gene from S. mutans GS-5 and generated recombinant N-terminal AgI/II protein. In this study, we further produced a hybridoma line expressing anti-AgI/II monoclonal antibodies named as 1C11A. This antibody showed high sensitivity to AgI/II protein in Western blot and ELISA. This new reagent will provide a basis for investigating the mechanisms of AgI/II-related diseases.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.2
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• pp.247-254
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• 2007

Mutans streptococci have been reported to be implicated in dental caries. Of these streptococcal species, Streptcoccus mutans and Streptococcus sobrinus are most commonly found in human dental caries. Prevalence of these bacterial species in dental caries is found to be varied in different races and countries. Therefore, importance of these bacteria in dental caries remains to be determined The present study was performed to find out correlation S. mutans and S. sobrinus with dental caries in 125 Korean children with mixed dentition between 6 to 11 years of age. They were classified as group A(6-8 years) and group B(9-11 years) by age. For the study, stimulated saliva samples were collected from each subject. The vials containing saliva specimens were serially diluted (1:10) in saline and plated in duplicate on tryptone-yeast extract-cysteine with sucrose and bacitracin (TYCSB) for S. mutans and S. sobrinus. After genomic DNA was extracted from the samples, polymerase chain reaction (PCR) amplification was performed for identification using universal primers and specific primers to S. mutans and S. sobrinus. Data of microbial variables were compared to caries status of the subjects. According to this study, the result were as follows : 1. S. mutans versus S. sobrinus were moderate positive linear correlated in both group A(r=0.70) and group B(r=0.50). 2. Between S. mutans and dental caries there were weak positive linear correlation in both group A(r= 0.25) and group B(r=0.34). 3. S. sobrinus versus dental caries were not correlated in group A but slightly correlated in group B(r=0.21). 4. Between S. mutans and age, there were not correlation in both group. 5. S. sobrinus versus age were weak correlated in group A(r=0.32) but not correlated in group B.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.73-82
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• 2008

Dental caries is an infectious disease caused by mutans streptococci, and is a primary etiologic agent of dental caries in humans. The molecular pathogenesis of mutans streptococcal-associated dental caries occurs in three phases. Firstly, S. mutans attaches to tooth surface via a cell surface adhesion termed antigen I/II. In the second phase, the glucosyltransferase(GTFs) synthesize polymers like glucans in the presence of sucrose. In the third phase, the multivalent glucans interacts with glucan binding proteins (GBPs) and they make dental plaque and accumulation of microorganisms. Many studies and clinical trials have indicated that a mucosal immune response to these antigens(Ag I/II, GTFs, GBPs) of S. mutans can influence the pathogenesis of dental caries. So these antigens can be important vaccine candidates for immunologic intervention against dental caries. In this study, we cloned the genes for GTFb, GTFc, GTFd from S. mutans GS-5 and did the nucleotide sequence analysis. And the recombinant proteins of GTFd and N-terminus of GTFd were expressed. Intact GTF which we get from this experiment can be used for antibody production specific for any GTF activity domain through animal experiment.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.505-513
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• 2009

Streptococcus mutans plays a major role in the formation of dental plaque and it is considered one of the important pathogens in the development of dental caries. Established dental plaque can be more resistant to antimicrobial agents and offers nutrient rich and relatively stable cariogenic conditions for bacteria. Thus bacteria growing in dental plaque have strong resistance to antimicrobial agents and they are not removed easily by the flow of saliva. Many researchers have been performed using natural materials, especially herbal extracts to prevent dental plaque. However, the strains of mutans streptococci used in the researches were not from Koreans. Therefore, it would be necessary to evaluate the antimicrobial activity of herbal extracts against clinical isolates of Streptococcus mutans isolated from saliva of Koreans living in Jeollabuk-do. For this study four clinical isolates were isolated from saliva samples of seventeen Korean people to investigate whether essential oils of Artemisia spp. have antimicrobial activity against them including four reference strains of Streptococcus mutans. Minimum inhibitory concentrations, Minimum bactericidal concentrations and time kill studies were performed and the results showed that Artemisia lavandulaefolia DC, Artemisia scoparia, and Artemisia capillaries have antimicrobial activity against the Streptococcus mutans clinical isolates and reference strains.

• Journal of dental hygiene science
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• v.13 no.2
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• pp.182-190
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• 2013

Composition of oral microbial flora is suggested to play a role in the maintenance of oral health. Among them, Streptococcus mutans plays an essential role in the formation of dental plaque and it is being noticed as incipient infective bacteria of dental caries. The purpose of this study was to prepare the basic data about distribution of Streptococcus mutans detected from saliva by measuring colony density. It is well known that smoking as well as drinking is a factor of dental caries, however there are few investigations about distribution of Streptococcus mutans either smoking or drinking. The materials of this study were collected from students of dentistry college with general characteristics obtained by self-administered questionnaires. Students were asked to gently chew the paraffin to get saliva for 1 minute. Bacitracin disc in the culture medium was activated for 15 minutes, and then sample was incubated in the activated medium at $37^{\circ}C$ incubator for 48 hours. Streptococcus mutans colonization per 1 ml saliva was measured by the number of criteria. The severe levels of dental caries activity were significantly increased in the case of smoking (from 5.6% to 10%) or drinking (form 0% to 7%), respectively. Also, dental caries activity increased according to smoking and drinking periods longer. However, using the SPSS analytical process (Mann-Whitney's U), no significant differences were observed between the smoking and the non-smoking or the drinking and non-drinking, respectively. These results obtained from dental caries activity of saliva suggest that distribution of Streptococcus mutans following smoking or drinking can be used as a significant information for oral health.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1567-1571
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• 2006

Lophatheri Herba of Lophatherum gracile Bronghiart(Gramineae) has long been used for treatment of inflammation, fever and edema in Korea. In order to investigate antibacterial activity of the Lophatheri Herba against Streptococcus mutans ATCC27351, paper disc test and pH check were carried out with 80% ethanol extract of Lophatheri Herba(LEX). The LEX showed significant antibacterial activity. And at the dose of 50 mg/kg, LEX showed signifiant inhibition on the paw edema, vascular permeability and myeloperoxidase activity in rat's paw tissue. These results indicate that LEX has antibacterial activity against the Streptococcus mutans and anti-inflammatory effect.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.32-40
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• 2018

The aim of this study was to determine the efficacy of a 3 tone plaque disclosing gel in assessing the risk of caries related to the population of Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus spp. quantified using a quantitative real-time polymerase chain reaction (qRT-PCR). 15 healthy children of ages 9 - 12 years were randomly examined. The 3 tone plaque disclosing gel was applied on teeth surfaces, which changed the color to pink or red, blue or purple and light blue. Plaque was divided into 3 groups based on staining. Genomic DNA from each sample was subjected to a qRT-PCR assay for quantitative detection of target bacteria. The Kruskal-Wallis test was conducted for correlation between the color of plaque and the number of bacterial species. The levels of S. mutans, S. sobrinus, and Lactobacillus spp. were significantly different in the plaque samples of the 3 groups (p < 0.05). The proportion of S. sobrinus to S. mutans showed correlation to the color of plaque. The different color-dyed plaque was related to the number of acidogenic bacteria. The 3 tone plaque disclosing gel could be used as one of the indicators to assess the clinical risk of caries associated with the population of S. mutans, S. sobrinus, and Lactobacillus spp.

• Journal of Oral Medicine and Pain
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• v.32 no.1
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• pp.45-55
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• 2007

Plant extract has attracted considerable interest in oral disease therapy. The present study was performed to observe the antibacterial effect on cariogenic Streptococcus mutans GS5 and Streptococcus sobrinus 6715, and periodontopathic Actinobacillus actinomycetemcomitans Y4 of phytoncide from Chamaecyparis obtusa Sieb. et Zucc employing the measurement of optical density, viable cell counts, and antibiotic sensitivity. The results were as follows: 1. Minimum inhibitory concentration of the phytoncide for S. mutans, S. sobrinus, and A. actinomycetemcomitans was observed to be 0.5%, 1%, and 0.2%, respectively. 2. Minimum bactericidal concentration of the phytoncide for S. mutans, S. sobrinus, and A. actinomycetemcomitans was determined to be 0.5%, 2%, and 0.2%, respectively. 3. The bacteria exposed to the phytoncide become more sensitive to antibiotics. The phytoncide enhanced significantly antibacterial activity of ampicillin against S. mutans and S. sobrinus. It also increased significantly the activity of penicillin and amoxicillin against S. sobrinus. In contrast, the phytoncide augmented the activity of amoxicillin and cefotaxime against A. actinomycetemcomitans but the increase was not statistically significant. The overall results indicate that phytoncide from Chamaecyparis obtusa Sieb. et Zucc used for this study has a strong antibacterial activity against cariogenic and periodontopathic bacteria and that it also has permeabilizing effect on certain antibiotics against these bacteria. Therefore, the phytoncide may be used as a candidate for prevention and therapeutic agent against oral infectious disease including dental caries and periodontal disease.

• Korean Journal of Oriental Medicine
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• v.12 no.1
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• pp.69-75
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• 2006

This research was aimed to search for natural antimicrobial agents that are sefe for humans and specific for oral pathogens. Acanthoic was isolated from the chloroform fraction of methanol extract of Acanthopanax koreanum $N_{AKAI}$ and its structure were elucidated by 13-NMR, 1H-NNR and ESIMS. Antibacterial activity of acanthoic acid was investigated by the minimum inhibitory (MIC) and minimun bactericidal (MBC) concentration. MIC/MBC of acanthoic acid against Streptococcus mutans $N_{AKAI}$ causing dental caries was determined to be $2/4\;{\mu}g/mL$, which was much lower than these of other natural antimicrobial agents such as $8/16\;{\mu}g/mL$ of sangurinarine and $250/500\;{\mu}/mL$ of green tea extract, $500/600\;{\mu}g/mL$ of thymol and borneol. Acanthoic and significantly inhibited the growth of other cariogenic bacteria such as Streptococcus sobrinus $N_{AKAI}$ and Streptococcus sanguis $N_{AKAI}$, and Streptococcus gordonii $N_{AKAI}$ in the MIC range of $4{\sim}32\;{\mu}g/mL$. My finding suggests that acanthoic acid could be employed as a potential antibacterial agent for preventing dental caries.