scholarly journals Effects of brief sodium fluoride treatments on the growth of early and mature cariogenic biofilms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ye Han

AbstractAlthough fluoride has been widely used as a preventive agent for dental caries, the effects of fluoride on the activities of biofilms in different stages of cariogenic biofilm formation are less studied. This study was designed to investigate the antibiofilm activity of sodium fluoride during the early and mature stages of Streptococcus mutans (S. mutans) biofilm formation. S. mutans biofilms were formed on saliva-coated hydroxyapatite disks. In the early (0–46 h) and mature (46–94 h) biofilm stages, the biofilms were treated with different concentrations of fluoride (250, 500, 1000, 2000 ppm; 5 times in total, 1 min/treatment). Acidogenicity, dry weight, colony-forming units (CFUs), water-soluble/insoluble extracellular polysaccharides (EPSs), and intracellular polysaccharides were analysed, and confocal laser scanning microscopy images were obtained of the two stages of biofilms to determine antibiofilm activities of fluoride at varying concentrations during the formation of early and mature biofilms. In the early stages of cariogenic biofilm formation, test groups with all fluoride concentrations significantly inhibited the growth of S. mutans biofilms. The antibiofilm and anti-EPS formation activities of the brief fluoride treatments increased with a concentration-dependent pattern. At the mature biofilm stage, only the 2000 ppm fluoride treatment group significantly inhibited biofilm accumulation, activity, and intracellular/extracellular polysaccharide content compared with those of the control and other fluoride treatment groups. The antimicrobial effect of fluoride treatment on the growth of S. mutans biofilms was linked with the stage of cariogenic biofilm formation. The inhibition of S. mutans biofilm growth by fluoride treatment was easier in the early formation stage than in the mature stage. Fluoride treatment in the early stage of cariogenic biofilm formation may be an effective approach to controlling cariogenic biofilm development and preventing dental caries.

2021 ◽  
Author(s):  
Ye Han

Abstract Although fluoride has been widely used in the prevention of dental caries, the effect of fluoride on the activity of biofilm in different stages of cariogenic biofilm formation is less studied. This study aimed to investigate the antibiofilm activity of sodium fluoride during early and mature Streptococcus mutans (S. mutans) biofilms formation. S. mutans biofilms were formed on saliva-coated hydroxyapatite disks. In the early (0 ~ 46 h) and mature (46 ~ 94 h) biofilm stages, the biofilm was treated with different concentrations of fluoride (250, 500, 1000, 2000 ppm; 5 times in total, 1 min/treatment). Acidogenicity, dry weight, colony-forming units, water-soluble/insoluble extracellular polysaccharides (EPS), and intracellular polysaccharides were analyzed and confocal laser scanning microscopy images were obtained of the two stages of biofilms (early and mature biofilms). To determine the antibiofilm activity of sodium fluoride during the formation of early and mature biofilms, and to evaluate the relationship between different concentrations of sodium fluoride and antibiofilm activity. In the early cariogenic biofilm formation stage, all fluoride concentration test groups (250, 500, 1000, 2000 ppm) significantly inhibited the growth of S. mutans biofilm. The antibiofilm and anti-EPS formation activities of the brief fluoride treatment increased in a concentration-dependent pattern. At the mature biofilm stage, only the 2000 ppm fluoride treatment group significantly inhibited biofilm accumulation, activity, and intracellular/extracellular polysaccharide content compared with the control and other fluoride treatment groups. The antimicrobial activity of fluoride is related to the formation stage of cariogenic biofilm. The early formation stage of cariogenic biofilm is more susceptible to the inhibition of fluorine than the mature stage. The fluoride treatment in the early formation stage of cariogenic biofilm may be an effective means to control the development of cariogenic biofilm and prevent caries.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yutao Yang ◽  
Shiyu Liu ◽  
Yuanli He ◽  
Zhu Chen ◽  
Mingyun Li

Streptococcus mutans, with the ability of high-rate acid production and strong biofilm formation, is considered the predominant bacterial species in the pathogenesis of human dental caries. Natural products which may be bioactive againstS. mutanshave become a hot spot to researches to control dental caries. LongZhang Gargle, completely made from Chinese herbs, was investigated for its effects on acid production and biofilm formation byS. mutansin this study. The results showed an antimicrobial activity of LongZhang Gargle againstS. mutansplanktonic growth at the minimum inhibitory concentration (MIC) of 16% and minimum bactericidal concentration (MBC) of 32%. Acid production was significantly inhibited at sub-MIC concentrations. Biofilm formation was also significantly disrupted, and 8% was the minimum concentration that resulted in at least 50% inhibition of biofilm formation (MBIC50). A scanning electron microscopy (SEM) showed an effective disruption of LongZhang Gargle onS. mutansbiofilm integrity. In addition, a confocal laser scanning microscopy (CLSM) suggested that the extracellular polysaccharides (EPS) synthesis could be inhibited by LongZhang Gargle at a relatively low concentration. These findings suggest that LongZhang Gargle may be a promising natural anticariogenic agent in that it suppresses planktonic growth, acid production, and biofilm formation againstS. mutans.


2007 ◽  
Vol 62 (5-6) ◽  
pp. 433-438 ◽  
Author(s):  
Elzbieta Walencka ◽  
Marzena Wieckowska-Szakiel ◽  
Sylwia Rozalska ◽  
Beata Sadowska ◽  
Barbara Rozalska

Bacterial biofilms which are responsible for a number of diseases are very difficult to control effectively because of their high resistance to antibiotics and the host defence system. The use of natural products decreasing or preventing initial adhesion of bacteria and biofilm formation is one of the alternative therapeutic strategies taken into consideration. We ask the question, whether a crude extract from the cell wall of Saccharomyces cerevisiae (mannoprotein), which possesses surfactant activity, may be used as inhibitor of Staphylococcus aureus and S. epidermidis biofilm development. By using the “bactericidal spot assay” it was demonstrated that mannoprotein had no direct antibiotic activity against the tested strains. The influence of this extract on initial adhesion, biofilm formation and dispersal of preformed biofilms was studied using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. In this assay, live bacteria with an active electron transport system reduce the tetrazolium salt to a water-soluble purple formazan product, and optical density reading (A550) values are directly dependent on their cell numbers. Yeast-derived surfactant, when adsorbed in the microplate wells or present in the medium, was effective both in decreasing the initial deposition of staphylococci and in reducing the amount of growing biofilm, quantitated after 24 h of co-incubation with the bacteria. It also changed the parameters of biofilm morphology analyzed by PHLIP - the confocal laser scanning microscopy image quantification package. Mannoprotein also accelerated the detachment of mature staphylococcal biofilms, preformed in optimal conditions. It was concluded that mannoprotein anti-biofilm action reflects its influence on cell surface hydrophobicity.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yalan Deng ◽  
Yingming Yang ◽  
Bin Zhang ◽  
Hong Chen ◽  
Yangyu Lu ◽  
...  

AbstractStreptococcus mutans (S. mutans) is generally regarded as a major contributor to dental caries because of its ability to synthesize extracellular polysaccharides (EPS) that aid in the formation of plaque biofilm. The VicRKX system of S. mutans plays an important role in biofilm formation. The aim of this study was to investigate the effects of vicK gene on specific characteristics of EPS in S. mutans biofilm. We constructed single-species biofilms formed by different mutants of vicK gene. Production and distribution of EPS were detected through atomic force microscopy, scanning electron microscopy and confocal laser scanning microscopy. Microcosmic structures of EPS were analyzed by gel permeation chromatography and gas chromatography-mass spectrometry. Cariogenicity of the vicK mutant was assessed in a specific pathogen-free rat model. Transcriptional levels of cariogenicity-associated genes were confirmed by quantitative real-time polymerase chain reaction. The results showed that deletion of vicK gene suppressed biofilm formation as well as EPS production, and EPS were synthesized mostly around the cells. Molecular weight and monosaccharide components underwent evident alterations. Biofilms formed in vivo were sparse and contributed a decreased degree of caries. Moreover, expressional levels of genes related to EPS synthesis were down-regulated, except for gtfB. Our report demonstrates that vicK gene enhances biofilm formation and subsequent caries development. And this may due to its regulations on EPS metabolism, like synthesis or microcosmic features of EPS. This study suggests that vicK gene and EPS can be considered as promising targets to modulate dental caries.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259895
Author(s):  
Ye Han

The increased incidence of dental caries by cigarette smoking (CS) has been widely reported in epidemiological studies, but the relationship between CS and cariogenic biofilm growth has been rarely studied. This study aims to investigate the effects of CS exposure on the growth and virulence of Streptococcus mutans biofilms (S. mutans). Briefly, S. mutans biofilms were formed on saliva-coated hydroxyapatite disks, which were exposed to CS 1, 3, and 6 times per day, respectively. In addition, S. mutans biofilms without CS exposure were considered as the control group. Acidogenicity, dry weight, colony-forming units (CFUs), water-soluble/insoluble extracellular polysaccharides (EPSs), and intracellular polysaccharides (IPSs) were analyzed and confocal laser scanning microscopy (CLSM) images of 74-h-old S. mutans biofilms were obtained. The lowest accumulation of biofilms and EPSs were detected in the 6 times/day CS exposure group compared with those of the control group and other CS exposure groups in 74-h-old S. mutans biofilms. CLSM also revealed the lowest bacterial count (live and dead cells) and EPSs biovolume in the six times/day CS exposure group in 74-h-old S. mutans biofilms. CS exposure inhibited the growth of S. mutans biofilm in vitro study, the anti-cariogenic biofilm formation was enhanced with a dose (frequency)-dependent at which frequency has more influence in the present findings.


2010 ◽  
Vol 55 (2) ◽  
pp. 860-866 ◽  
Author(s):  
Zhao-Xiang Peng ◽  
Bing Tu ◽  
Yang Shen ◽  
Lin Du ◽  
Ling Wang ◽  
...  

ABSTRACTOur previous study (Z. X. Peng et al., Carbohydr. Polym.81:275-283, 2010) demonstrated that water-soluble quaternary ammonium salts, which are produced by the reaction of chitosan with glycidyl trimethylammonium chloride, provide chitosan derivatives with enhanced antibacterial ability. Because biofilm formation is believed to comprise the key step in the development of orthopedic implant-related infections, we further evaluated the efficacy of hydroxypropyltrimethyl ammonium chloride chitosan (HACC) with different degrees of substitution (DS; referred to as HACC 6%, 18%, and 44%) in preventing biofilm formation on a titanium surface. We used a tissue culture plate method to quantify the biomass ofStaphylococcus epidermidisandStaphylococcus aureusbiofilms and found that HACC, especially HACC 18% and 44%, significantly inhibited biofilm formation compared to the untreated control, even at concentrations far below their MICs (P< 0.05). Scanning electron microscopy showed that inhibition of biofilm formation on titanium increased dramatically with increased DS and HACC concentrations. Confocal laser scanning microscopy indicated that growth of a preexisting biofilm on titanium was inhibited by concentrations of HACC 18% and 44% below their minimum biofilm eradication concentrations. We also demonstrated that HACC inhibited the expression oficaA, which mediates the production of extracellular polysaccharides, both in new biofilms and in preexisting biofilms on titanium. Our results indicate that HACC may serve as a new antibacterial agent to inhibit biofilm formation and prevent orthopedic implant-related infections.


2016 ◽  
Vol 6 (01) ◽  
pp. 5218
Author(s):  
Laxmi Mohandas ◽  
Anju T. R. ◽  
Sarita G. Bhat*

An assortment of redox-active phenazine compounds like pyocyanin with their characteristic blue-green colour are synthesized by Pseudomonas aeruginosa, Gram-negative opportunistic pathogens, which are also considered one of the most commercially valuable microorganisms. In this study, pyocyanin from Pseudomonas aeruginosa BTRY1 from food sample was assessed for its antibiofilm activity by micro titer plate assay against strong biofilm producers belonging to the genera Bacillus, Staphylococcus, Brevibacterium and Micrococcus. Pyocyanin inhibited biofilm activity in very minute concentrations. This was also confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Both SEM and CLSM helped to visualize the biocontrol of biofilm formation by eight pathogens. The imaging and quantification by CLSM also established the impact of pyocyanin on biofilm-biocontrol mainly in the food industry.


2019 ◽  
Vol 98 (7) ◽  
pp. 739-745 ◽  
Author(s):  
C. Cugini ◽  
M. Shanmugam ◽  
N. Landge ◽  
N. Ramasubbu

The oral cavity contains a rich consortium of exopolysaccharide-producing microbes. These extracellular polysaccharides comprise a major component of the oral biofilm. Together with extracellular proteins, DNA, and lipids, they form the biofilm matrix, which contributes to bacterial colonization, biofilm formation and maintenance, and pathogenesis. While a number of oral microbes have been studied in detail with regard to biofilm formation and pathogenesis, the exopolysaccharides have been well characterized for only select organisms, namely Streptococcus mutans and Aggregatibacter actinomycetemcomitans. Studies on the exopolysaccharides of other oral organisms, however, are in their infancy. In this review, we present the current research on exopolysaccharides of oral microbes regarding their biosynthesis, regulation, contributions to biofilm formation and stability of the matrix, and immune evasion. In addition, insight into the role of exopolysaccharides in biofilms is highlighted through the evaluation of emerging techniques such as pH probing of biofilm colonies, solid-state nuclear magnetic resonance for macromolecular interactions within biofilms, and super-resolution microscopy analysis of biofilm development. Finally, exopolysaccharide as a potential nutrient source for species within a biofilm is discussed.


2010 ◽  
Vol 59 (10) ◽  
pp. 1225-1234 ◽  
Author(s):  
H. M. H. N. Bandara ◽  
O. L. T. Lam ◽  
R. M. Watt ◽  
L. J. Jin ◽  
L. P. Samaranayake

The objective of this study was to evaluate the effect of the bacterial endotoxin LPS on Candida biofilm formation in vitro. The effect of the LPS of Pseudomonas aeruginosa, Klebsiella pneumoniae, Serratia marcescens and Salmonella typhimurium on six different species of Candida, comprising Candida albicans ATCC 90028, Candida glabrata ATCC 90030, Candida krusei ATCC 6258, Candida tropicalis ATCC 13803, Candida parapsilosis ATCC 22019 and Candida dubliniensis MYA 646, was studied using a standard biofilm assay. The metabolic activity of in vitro Candida biofilms treated with LPS at 90 min, 24 h and 48 h was quantified by XTT reduction assay. Viable biofilm-forming cells were qualitatively analysed using confocal laser scanning microscopy (CLSM), while scanning electron microscopy (SEM) was employed to visualize the biofilm structure. Initially, adhesion of C. albicans was significantly stimulated by Pseudomonas and Klebsiella LPS. A significant inhibition of Candida adhesion was noted for the following combinations: C. glabrata with Pseudomonas LPS, C. tropicalis with Serratia LPS, and C. glabrata, C. parapsilosis or C. dubliniensis with Salmonella LPS (P<0.05). After 24 h of incubation, a significant stimulation of initial colonization was noted for the following combinations: C. albicans/C. glabrata with Klebsiella LPS, C. glabrata/C. tropicalis/C. krusei with Salmonella LPS. In contrast, a significant inhibition of biofilm formation was observed in C. glabrata/C. dubliniensis/C. krusei with Pseudomonas LPS, C. krusei with Serratia LPS, C. dubliniensis with Klebsiella LPS and C. parapsilosis/C. dubliniensis /C. krusei with Salmonella LPS (P<0.05). On further incubation for 48 h, a significant enhancement of biofilm maturation was noted for the following combinations: C. glabrata/C. tropicalis with Serratia LPS, C. dubliniensis with Klebsiella LPS and C. glabrata with Salmonella LPS, and a significant retardation was noted for C. parapsilosis/C. dubliniensis/C. krusei with Pseudomonas LPS, C. tropicalis with Serratia LPS, C. glabrata/C. parapsilosis/C. dubliniensis with Klebsiella LPS and C. dubliniensis with Salmonella LPS (P<0.05). These findings were confirmed by SEM and CLSM analyses. In general, the inhibition of the biofilm development of LPS-treated Candida spp. was accompanied by a scanty architecture with a reduced numbers of cells compared with the profuse and densely colonized control biofilms. These data are indicative that bacterial LPSs modulate in vitro Candida biofilm formation in a species-specific and time-dependent manner. The clinical and the biological relevance of these findings have yet to be explored.


Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3170 ◽  
Author(s):  
Vika Gabe ◽  
Tomas Kacergius ◽  
Saleh Abu-Lafi ◽  
Mouhammad Zeidan ◽  
Basheer Abu-Farich ◽  
...  

The accumulation of biofilm by Streptococcus mutans bacteria on hard tooth tissues leads to dental caries, which remains one of the most prevalent oral diseases. Hence, the development of new antibiofilm agents is of critical importance. The current study reports the results from testing the effectiveness of octyl gallate (C8-OG) against: (1) S. mutans biofilm formation on solid surfaces (polystyrene, glass), (2) acidogenicity, (3) and the expression of biofilm-related genes. The amount of biofilm formed by S. mutans bacteria was evaluated using the colorimetric method and optical profilometry. The pH of the biofilm growth medium was measured with microelectrode. A quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was used to assess the expression of genes encoding glucan binding protein B (gbpB), glucosyltransferases B, -C, -D (gtfB, -C, -D), and the F-ATPase β subunit of the F1 protein (atpD). The results show that C8-OG significantly diminished biofilm formation by exposed S. mutans on solid surfaces and suppressed acidogenicity in a dose-dependent manner, compared to unexposed bacteria (p < 0.05). The C8-OG concentration of 100.24 µM inhibited S. mutans biofilm development on solid surfaces by 100% and prevented a decrease in pH levels by 99%. In addition, the RT-qPCR data demonstrate that the biofilm-producing bacteria treated with C8-OG underwent a significant reduction in gene expression in the case of the four genes under study (gbpB, gtfC, gtfD, and atpD), and there was a slight decrease in expression of the gtfB gene. However, C8-OG treatments did not produce significant expression change compared to the control for the planktonic cells, although there was a significant increase for the atpD gene. Therefore, C8-OG might be a potent antibiofilm and/or anticaries agent for oral formulations that aim to reduce the prevalence of dental caries.


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