Production and use of carrier-free18F in studies on the effect of trace amounts of fluoride on the metabolism of the oral cariogenic bacterium Streptococcus mutans

1988 ◽  
Vol 122 (2) ◽  
pp. 327-331 ◽  
Author(s):  
N. Psapros ◽  
H. Duschner
2012 ◽  
Vol 79 (5) ◽  
pp. 1436-1443 ◽  
Author(s):  
Kei Fujishima ◽  
Miki Kawada-Matsuo ◽  
Yuichi Oogai ◽  
Masayuki Tokuda ◽  
Mitsuo Torii ◽  
...  

ABSTRACTLarge numbers of bacteria coexist in the oral cavity.Streptococcus sanguinis, one of the major bacteria in dental plaque, produces hydrogen peroxide (H2O2), which interferes with the growth of other bacteria.Streptococcus mutans, a cariogenic bacterium, can coexist withS. sanguinisin dental plaque, but to do so, it needs a means of detoxifying the H2O2produced byS. sanguinis. In this study, we investigated the association of three oxidative stress factors, Dpr, superoxide dismutase (SOD), and AhpCF, with the resistance ofS. sanguinisto H2O2. The knockout ofdprandsodsignificantly increased susceptibility to H2O2, while the knockout ofahpCFhad no apparent effect on susceptibility. In particular,dprinactivation resulted in hypersensitivity to H2O2. Next, we sought to identify the factor(s) involved in the regulation of these oxidative stress genes and found that PerR negatively regulateddprexpression. The knockout ofperRcaused increaseddprexpression levels, resulting in low-level susceptibility to H2O2compared with the wild type. Furthermore, we evaluated the roles ofperR,dpr, andsodwhenS. mutanswas cocultured withS. sanguinis. Culturing of thedprorsodmutant withS. sanguinisshowed a significant decrease in theS. mutanspopulation ratio compared with the wild type, while theperRmutant increased the ratio. Our results suggest thatdprandsodinS. mutansare involved in coexistence withS. sanguinis, and PerR is associated with resistance to H2O2in regulating the expression of Dpr.


2018 ◽  
Vol 53 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Kyungsun Kim ◽  
Jung-Sub An ◽  
Bum-Soon Lim ◽  
Sug-Joon Ahn

Bisphenol A glycidyl methacrylate (bis-GMA), which is released into the oral environment by dental composites through incomplete polymerization, hydrolysis, and mechanical degradation, can significantly influence oral ecology around resin-based materials. The purpose of this study was to investigate how bis-GMA changes the virulence properties of Streptococcus mutans, a major cariogenic bacterium in humans. The results show that bis-GMA not only inhibited the planktonic growth of cells in medium containing glucose, fructose, or mannose, but also reduced the viability of S. mutans. However, the presence of bis-GMA increased sugar transport and intracellular polysaccharide accumulation in S. mutans, thereby increasing the potential of cell persistence. In addition, bis-GMA could enhance S. mutans’s adhesion to hard surfaces and glucan synthesis, which could contribute to biofilm formation. Although free bis-GMA made cells vulnerable to acidic stress, it also provided increased resistance to hydrogen peroxide, which might confer an advantage in competition with other oral microorganisms during the early stage of biofilm development. Interestingly, the presence of bis-GMA did not change the ability of S. mutans to interact with saliva. The results suggest that leachable bis-GMA could contribute to biofilm-related secondary dental caries at the marginal interface between resin-based materials and teeth by altering the virulent properties of S. mutans, although bis-GMA reduced the planktonic growth and viability of S. mutans.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ronit Vogt Sionov ◽  
Danae Tsavdaridou ◽  
Muna Aqawi ◽  
Batya Zaks ◽  
Doron Steinberg ◽  
...  

Abstract Background Streptococcus mutans is a common cariogenic bacterium in the oral cavity involved in plaque formation. Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) has been introduced into tooth mousse to encourage remineralization of dental enamel. The aim of this research was to study the effect of tooth mousse containing CPP-ACP (GC Tooth Mousse®) or CPP-ACP with 0.2% fluoride (CPP-ACPF; GC Tooth Mousse Plus®; GCP) on S. mutans planktonic growth and biofilm formation. Methods S. mutans was cultivated in the presence of different dilutions of the tooth mousse containing CPP-ACP or CPP-ACPF, and the planktonic growth was determined by ATP viability assay and counting colony-forming units (CFUs). The resulting biofilms were examined by crystal violet staining, MTT metabolic assay, confocal laser scanning microscopy (CLSM), and scanning electron microscope (SEM). Results The CPP-ACP tooth mousse (GC) at a dilution of 5–50 mg/ml (0.5–5%) did not inhibit planktonic growth, and even increased the ATP content and the number of viable bacteria after a 24 h incubation. The same was observed for the CPP-ACPF tooth mousse (GCP), except for the higher concentrations (25 and 50 mg/ml) that led to a drop in the bacterial count. Importantly, both compounds significantly decreased S. mutans biofilm formation at dilutions as low as 1.5–3 mg/ml. 12.5 mg/ml GC and 6.25 mg/ml GCP inhibited biofilm formation by 90% after 4 h. After 24 h, the MBIC90 was 6.25 mg/ml for both. CLSM images confirmed the strong inhibitory effect GC and GCP had on biofilm formation when using 5 mg/ml tooth mousse. SEM images of those bacteria that managed to form biofilm in the presence of 5 mg/ml tooth mousse, showed alterations in the bacterial morphology, where the streptococci appear 25–30% shorter on the average than the control bacteria. Conclusion Our data show that the tooth mousse containing CPP-ACP reduces biofilm formation of the cariogenic bacterium S. mutans without killing the bacteria. The use of natural substances which inhibit biofilm development without killing the bacteria, has therapeutic benefits, especially in orthodontic pediatric patients.


2021 ◽  
Author(s):  
Shuhei Ikeda ◽  
Satoshi Saito ◽  
Satoshi Hosoki ◽  
Shuichi Tonomura ◽  
Yumi Yamamoto ◽  
...  

Abstract Streptococcus mutans, a major cariogenic bacterium, expressing the collagen-binding protein Cnm induces cerebrovascular inflammation, resulting in the impairment of blood brain barrier integrity followed by cerebral bleeding. We here examined the association of Cnm-positive S. mutans with cerebral microbleeds (CMBs) in acute stroke patients selected from a single-center registry database. Of 428 patients who received oral bacterial examinations among 3154 stroke patients, 326 patients who harbored S. mutans were identified. After excluding four patients without imaging data, we compared 72 patients with Cnm-positive S. mutans and 250 with Cnm-negative S. mutans. Deep, lobar and infratentorial CMBs were observed in 46 (63.9%), 36 (50.0%), 25 (34.7%) patients with Cnm-positive S. mutans and 144 (57.6%), 114 (45.6%), 101 (40.4%) with Cnm-negative S. mutans. Possession of Cnm-positive S. mutans was related to higher numbers of both deep and lobar, but not infratentorial, CMBs (risk ratios 1.57 [1.07‒2.30], deep; 5.44 [2.50‒11.85], lobar). Statistical significance persisted after adjusting for age, sex, hypertension, stroke type, National Institutes of Health Stroke Scale score, and cerebral amyloid angiopathy (risk ratios 1.61 [1.14‒2.27], deep; 5.14 [2.78‒9.51], lobar). Our study indicated that reduction of Cnm-positive S. mutans may serve as a therapeutic approach for improving the prognosis of stroke patients.


1989 ◽  
Vol 53 (9) ◽  
pp. 2307-2311 ◽  
Author(s):  
Senji SAKANAKA ◽  
Mujo KIM ◽  
Makoto TANIGUCHI ◽  
Takehiko YAMAMOTO

2011 ◽  
Vol 55 (6) ◽  
pp. 2679-2687 ◽  
Author(s):  
Chang Liu ◽  
Roberta J. Worthington ◽  
Christian Melander ◽  
Hui Wu

ABSTRACTStreptococcus mutansis a major cariogenic bacterium. It has adapted to the biofilm lifestyle, which is essential for pathogenesis of dental caries. We aimed to identify small molecules that can inhibit cariogenicS. mutansand to discover lead structures that could give rise to therapeutics for dental caries. In this study, we screened a focused small-molecule library of 506 compounds. Eight small molecules which inhibitedS. mutansat a concentration of 4 μM or less but did not affect cell growth or biofilm formation of commensal bacteria, represented byStreptococcus sanguinisandStreptococcus gordonii, in monospecies biofilms were identified. The active compounds share similar structural properties, which are characterized by a 2-aminoimidazole (2-AI) or 2-aminobenzimidazole (2-ABI) subunit. In multispecies biofilm models, the most active compound also inhibited cell survival and biofilm formation ofS. mutansbut did not affect commensal streptococci. This inhibitor downregulated the expression of six biofilm-associated genes,ftf,pac,relA,comDE,gbpB, andgtfB, in planktonicS. mutanscells, while it downregulated the expression of onlyftf,pac, andrelAin the biofilm cells ofS. mutans. The most potent compound also inhibited production of two key adhesins ofS. mutans, antigen I/II and glucosyltransferase (GTF). However, the compound did not alter the expression of the corresponding genes in bothS. sanguinisandS. gordonii, indicating that it possesses a selective inhibitory activity againstS. mutans.


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