• 치위생과학회지
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• 제23권2호
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• pp.103-111
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• 2023

Background: Some studies confirm the reduction of the number of Streptococcus mutans in saliva and dental plaque by Lactobacillus, however, these effects are not always confirmed in in vitro and clinical studies, and only the risk of dental caries has been reported. Our in vitro study aimed to reveal microbial and biochemical changes in the single cultures of S. mutans, Lactobacillus casei and Aggregatibactor actinomycetemcomitans and co-cultures of S. mutans and L. casei or A. actinomycetemcomitans according to sucrose concentration. We also aimed to confirm the anti-oral bacterial and anti-biofilm activities of L. casei and A. actinomycetemcomitans against S. mutans according to sucrose concentration. Methods: S. mutans (KCCM 40105), L. casei (KCCM 12452), and A. actinomycetemcomitans (KCTC 2581) diluted to 5×10⁶ CFU/ml were single cultured, and L. casei or A. actinomycetemcomitans applied at concentrations of 10%, 20%, 30% and 40% to S. mutans were co-cultured with selective medium containing 0%, 1% and 5% sucrose at 36.5℃ for 24 hours. Measurements of bacterial growth value and acid production, disk diffusion and biofilm formation assays were performed. Results: In the medium containing sucrose, the bacterial growth and biofilm formation by S. mutans, L. casei, and A. actinomycetemcomitans were increased. In contrast, 30% and 40% of L. casei in the medium containing 0% sucrose showed both anti-oral bacterial and anti-biofilm activities. This implies that L. casei can be used as probiotic therapy to reduce S. mutans in a 0% sucrose environment. Conclusion: The concentration of sucrose in the oral environment is important for the control of pathogenic bacteria that cause dental caries and periodontitis. To apply probiotic therapy using L. casei for S. mutans reduction, the concentration of sucrose must be considered.

• 대한의생명과학회지
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• 제13권4호
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• pp.341-347
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• 2007

Streptococcus mutans, one of a major causal agents of dental caries, is component of the dental plaque and produces various organic acids such as lactic acid as the end-product of glycolysis. In this study, we isolated S. mutans from Korean children with caries and also investigated the expression of protein under acid stress. S. mutans was identified at the species level using a 16S ribosomal DNA sequencing comparison method. The primer specificity was tested on eleven S. mutans strains isolated from Korean children with caries. The data showed that eleven strains are S. mutans. At treatment of concentration of 20 mM lactic acid in the mid-log phage, K-7 exhibited the highest maximum culture OD compared with those of other groups. As a consequence, we examined the expression of protein under 20 mM lactic acid stress using S. mutans K-7. The results of 2D gel electrophoresis by image analysis showed that thirteen proteins are up-regulated under the stress. Further study is being focused on amino acid analysis by mass spectrometry in order to analyze those spots.

• Restorative Dentistry and Endodontics
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• 제6권1호
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• pp.93-103
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• 1980

Streptococcus mutans were isolated from dental plaques of carious lesions of 4 patients on mitis-salivarius agar medium. Three patients known to harbor S. mutans in their dental plaques. Identification of the isolated S. mutans was established by colonial morphology on mitis-salivarius agar medium, the fermentation of mannitol and sorbitol, and confirmed by agglutinating reaction with home made anti-S. mutans NCTC 10449 (serotype c) antiserum. Of the isolated S. mutans, one strain (P2-1) showed strong agglutinating reaction with antiserum, another strain (P1-2) showed weak agglutinating reaction. P2-1 strongly adhered to the wall of the test tube containing 5% sucrose broth, while p1-2 weakly colonized on the wall of the test tube. Biotyping of the isolated S. mutans based on the fermentation of mannitol, sorbitol, raffinose and melibiose, and the production of ammonia from L-arginine, and the inhibition of acid production by bacitracin. Biochemical characteristics of P2-1 strain correlated with the recognized biotype c, pl-2 strain resembled biotype d of S. mutans.

• 대한치과의사협회지
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• 제48권6호
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• pp.436-442
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• 2010

Objective: Transmission of S. mutans, a major dental caries pathogen, occurs mainly during the first 2.5 years of age. Children appear to acquire S. mutans mostly from their mothers, but few studies have investigated preventive effect of xylitol to S. mutans transmission from mother to child. The aim of this study was to perform a follow-up evaluation the preventive effect of xylitol chewing gum of the S. mutans of children's oral cavities, which included the characteristics of vertical transmission from mother to child. Methods: The mothers voluntarily participating in a women's oral health prevention program were divided into two groups (a control and a xylitol group). The subjects were 20 mother-child pairs, who were monitored for 30 months. Xylitol chewing gum group had consumed 2 gum pellets, 3 times a day for 24 months, and then they were followed until 30 months. At baseline, 24 and 30 months whole stimulated saliva samples were collected from the mothers. Children were also recruited from 6 months to 30 months after birth and were collected their dental plaque samples. After isolation and identification, the analysis of the colony count, transmission electron microscopy and real-time RT-PCR were performed to analyze the characteristics of S. mutans. Results: The S. mutans counts decreased steadily in the xylitol group at 24 months, but increased at 30 months. The similar results were showed at their children. While the glucan synthesis was decreased at xylitol group both mother and child. The expression of gtfB, gtfD and ftf were significantly reduced in the xylitol group both mother and child (p<0.05). Conclusions: These findings indicate that chewing xylitol gum over a long period may decrease the expression of the genes associated virulence and reduced the glucan synthesis of S. mutans, which can result the preventing the mother-to-child transmission of S. mutans.

• 치위생과학회지
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• 제4권3호
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• pp.127-131
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• 2004

본 연구는 소목 추출물의 S. mutans KCTC 3065에 대한 항균효과를 paper disc method로 검색하여, 소목의 S. mutans KCTC 3065 생장에 관한 영향을 평가하였다. 1. S. mutans KCTC 3065에 대한 소목 추출물의 최소생장 억제농도는 2.5mg/ml이었다. 2. 소목 추출물의 S. mutans KCTC 3065생장에 대한 효과는 대조군이 8시간에서 1.05로 최대 생장률을 보였으나, 소목 추출물을 2mg/ml을 투여한 배지에서는 16시간 만에 0.36으로 최대생장을 보였다. 3. S. mutans KCTC 3065를 8시간 동안 배양한 후 배지내 pH를 측정한 결과 대조군은 pH 5.08이었으며, 소목 추출물이 투여된 배지는 pH 6.69이었다. 4. S. mutans KCTC 3065를 8시간 동안 배양한 후 배지내 탄수화물 변화량을 측정한 결과 대조군은 0.81mg/ml이었으며, 소목 추출물이 투여된 배지는 2.06mg/ml 이었다. 5. S. mutans KCTC 3065를 8시간 동안 배양한 후 배지내 단백질 변화량을 측정한 결과 대조군은 8.39mg/ml이었으며, 소목 추출물이 투여된 배지는 12.3mg/ml 이었다. 6. S. mutans KCTC 3065의 다당류 생성에 미치는 효과는 대조군의 경우 배양 8시간에 300mg/100ml을 생성하였으나, 소목 추출물이 투여된 배지에서는 60mg/100ml을 생성하였다.

• 대한소아치과학회지
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• 제38권2호
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• pp.155-160
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• 2011

최근 들어, 수복 치료 등을 이용한 질병의 직접적인 치료보다는 예방 치료에 대한 중요성이 강조되면서, 그 동안 사용되었던 화학적인 약물을 통한 예방 치료 이외에도 유산균등을 이용한 probiotics에 대한관심이 높아지고 있다. 여러 논문에서 Lactobacillus와 Bifidobateria들이 DMFS와 S. mutans를 감소한다고 보고하고 있다. 하지만, 이러한 미생물들의 접종 시기와 접종 농도에 대한 언급은 부족하다. 따라서 본 실험에서는 probiotics의 대표적인 균인, L. rhamnosus GG를 이용하여 예방 효과를 보기 위한 적정 농도를 재정립하고, 접종시기를 고찰하였다. S. mutans 배지에 $1{\times}10^6$ CFU이상 농도의 L. rhamnosus를 접종하였을 때 S. mutans count가 현저하게 감소하는 것을 볼 수 있었다. 접종 순서는 L. rhamnosus와 S. mutans를 동시에 접종하거나 L. rhamnosus를 S. mutans 보다 선행하여 접종하였을 때가, S. mutans를 L. rhamnosus 보다 선행하여 접종하였을 때에 비교하여 S. mutans count를 더 감소시켰다. 이 실험의 결과로 보아 probiotics의 접종 시기는 probiotics을 임상에 적용할 때 반드시 고려되어야 하겠다.

• 약학회지
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• 제49권2호
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• pp.122-127
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• 2005

Dental caries is one of the most common oral diseases in the world. Glucosyltransferase (Gtase) of Streptococcus mutans (S. mutans) plays an important role in the develo pment of dental caries. For the purpose to develop anti- caries, we examined the effect of metabolites isolated from Streptomyces sp. M-20 on Gtase and the growth of S. mutans. Streptomyces sp. M-20 isolated from Mongolian soil showed 95~96% sequence homology with that of Streptomyces lin- colnensis. The metabolites of Streptomyces sp. M-20 were partially purified by extraction with ethyl acetate, silica gel column chromatography and preparative TLC. Partially purified metabolite, red colored component (MR-20) in ethyl acetate fraction showed potent antibacterial activitiy against S. mutans and inhibitory activity against Gtase purified from S. mutans, while another isolated yellow component (MY-20) showed no activity against S. mutans. The inhibitory activity of MR-20 against Gtase was confirmed by activity staining on SDS-polyacrylamide gel electrophoresis. The concentration of MR-20 for 50% inhibition $(IC_{50})$ against Gtase activity was $60{\mu}g/ml$. These results suggest that MR-20 can be developed for antibacterial agent and anticaries.

• 대한소아치과학회지
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• 제33권3호
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• pp.401-410
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• 2006

치아 우식은 구강 내 미생물에 의해 치아 석회 조직의 일부가 용해되고 파괴되는 감염성 질환이다. 치아 우식의 원인균은 Streptococcus mutans와 같은 Mutans streptococci로 알려져 있고, 이 미생물이 치면에 접착하여 군집을 형성하는 능력이 균의 독성에 중요한 역할을 한다. S. mutans가 치면의 타액성 피막에 부착하는 데에는 AgI/II와 같은 세포표면의 섬유성 단백질을 매개로 한다. 그러므로, AgI/II는 S. mutans GS-5에 대한 백신 개발에 적절한 목표가 된다. 본 실험은 S. mutans GS-5로부터 AgI/II 유전자를 복제하고 염기서열분석을 하였다. 복제된 AgI/II와 앞서 보고된 S. mutans GS-5의 해당 부위의 280개의 핵산은 완벽하게 일치하였다. 복제된 유전자를 두 부위로 절단하여 형질전환을 통해 재조합 단백질인 AgI/IImr을 얻었고, 정제된 재조합 단백질을 쥐에게 주입하여 다클론 항체를 얻었다. 추출된 다클론 항체는 AgI/IImr항원단백질에 반응하였고, 대조군으로 쓰인 단백질에는 반응하지 않았다.

• 대한치과교정학회지
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• 제24권1호
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• pp.181-192
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• 1994

The effect of topical application on the number of S. mutans was tested in a group of 44 orthodontic patients (mean age, 12Y 3M). They were divided into 5 groups according to the method using NaF and $SnF_2$. The number of S. mutans CFU were counted in stimulated saliva of each subject at baseline, and after one, two, three, and eight weeks. The following results were obtained. 1. In NaF rinsing group, and NaF topical application and NaF rinsing group, the number of S. mutans per ml saliva was not significantly changed. 2. In $SnF_2$ topical application group, and $SnF_2$ topical and NaF rinsing group, the number of S. mutans per ml saliva was significantly reduced. 3. After 8 weeks, there were no significant reduction of the number of S. mutans in comparison with baseline.

• Restorative Dentistry and Endodontics
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• 제42권1호
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• pp.39-47
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• 2017

Objectives: Although the coating of surface sealants to dental composite resin may potentially reduce bacterial adhesion, there seems to be little information regarding this issue. This preliminary in vitro study investigated the adhesion of Streptococcus mutans (S. mutans) on the dental composite resins coated with three commercial surface sealants. Materials and Methods: Composite resin (Filtek Z250) discs (8 mm in diameter, 1 mm in thickness) were fabricated in a mold covered with a Mylar strip (control). In group PoGo, the surfaces were polished with PoGo. In groups PS, OG, and FP, the surfaces polished with PoGo were coated with the corresponding surface sealants (PermaSeal, PS; OptiGuard, OG; Fortify Plus, FP). The surfaces of the materials and S. mutans cells were characterized by various methods. S. mutans adhesion to the surfaces was quantitatively evaluated using flow cytometry (n = 9). Results: Group OG achieved the lowest water contact angle among all groups tested (p < 0.001). The cell surface of S. mutans tested showed hydrophobic characteristics. Group PoGo exhibited the greatest bacterial adhesion among all groups tested (p < 0.001). The sealant-coated groups showed statistically similar (groups PS and FP, p > 0.05) or significantly lower (group OG, p < 0.001) bacterial adhesion when compared with the control group. Conclusions: The application of the surface sealants significantly reduced S. mutans adhesion to the composite resin polished with the PoGo.