-
Archives of Oral Biology Jan 2023To assess the effect of Nystatin on Candida albicans and Streptococcus mutans duo-species biofilms using an in vitro cariogenic biofilm model.
OBJECTIVE
To assess the effect of Nystatin on Candida albicans and Streptococcus mutans duo-species biofilms using an in vitro cariogenic biofilm model.
DESIGN
Biofilms were formed on saliva-coated hydroxyapatite discs under high sugar challenge (1 % sucrose and 1 % glucose), with inoculation of 10CFU/ml S. mutans and 10CFU/ml C. albicans. Between 20 and 68 h, biofilms were treated with 28,000 IU Nystatin solution, 5 min/application, 4 times/day, to mimic the clinical application. Biofilm's three-dimensional structure was assessed using multi-photon confocal microscopy. The expression of C. albicans and S. mutans virulence genes was assessed via real-time PCR. Duplicate discs were used in 3 independent repeats. t-test and Mann-Whitney U test were used to compare outcomes between treatment and control group.
RESULTS
Nystatin treatment eliminated C. albicans in biofilms at 44 h. Nystatin-treated group had a significant reduction of biofilm dry-weight and reduced S. mutans abundance by 0.5 log CFU/ml at 44 and 68 h (p < 0.05). Worth noting that biomass distribution across the vertical layout was altered by Nystatin treatment, resulting in less volume on the substrate layers in Nystatin-treated biofilms compared to the control. Reduction of microcolonies size and volume was also observed in Nystatin-treated biofilms (p < 0.05). Nystatin-treated biofilms formed unique halo-shaped microcolonies with reduced core EPS coverage. Furthermore, Nystatin-treated biofilms had significant down-regulations of S. mutans gtfD and atpD genes (p < 0.05).
CONCLUSIONS
Nystatin application altered the formation and characteristics of C. albicans and S. mutans duo-species biofilms. Therefore, developing clinical regimens for preventing or treating dental caries from an antifungal perspective is warranted.
Topics: Streptococcus mutans; Candida albicans; Nystatin; Dental Caries; Biofilms
PubMed: 36395564
DOI: 10.1016/j.archoralbio.2022.105582 -
European Journal of Paediatric Dentistry Mar 2020Oral streptococci were found to be associated with Early Childhood Caries. The aim of this study was to evaluate the 6 different bacteria in the streptococcus group in...
AIM
Oral streptococci were found to be associated with Early Childhood Caries. The aim of this study was to evaluate the 6 different bacteria in the streptococcus group in the saliva of children with severe early childhood caries (S-ECC) by polymerase chain reaction (PCR).
MATERIALS AND METHODS
A total of 60 children between 3 and 6 years of age were divided into two groups: children with S-ECC (Group S-ECC; n=30) and children who were caries-free (Group CF; n=30), according to the dmft and dmfs indices. Unstimulated saliva was collected from all participants for the detection of streptococcal group bacteria, including: Streptococcus mutans, Streptococcus oralis, Streptococcus sanguinis, Streptococcus gordonii, Streptococcus salivarius, and Streptococcus sobrinus, using PCR-restriction fragment length polymorphism (RFLP) of amplified 16S rRNA gene. The data were analysed using SPSS software.
RESULTS
The prevalence of S. oralis was significantly higher in the S-ECC group compared to the CF group (p<0.05). However, the frequencies of S. mutans, S. sanguinis, S. gordonii, S. salivarius, and S. sobrinus were similar between the two groups (p>0.05). The amount of streptococci colonies was higher in the S-ECC group compared to the CF group (p<0.05).
CONCLUSION
S. mutans or S. sobrinus alone may not be the only indicators for high risk of caries, but the prevalence of S. oralis in saliva may be a risk factor for increased caries activity in S-ECC.
Topics: Child; Child, Preschool; Dental Caries; Humans; RNA, Ribosomal, 16S; Saliva; Streptococcus; Streptococcus mutans; Streptococcus sobrinus
PubMed: 32183522
DOI: 10.23804/ejpd.2020.21.01.03 -
Frontiers in Cellular and Infection... 2021Recent studies have shown phenotypic and metabolic heterogeneity in related species including , a typical oral commensal bacterium, , a cariogenic bacterium, and , which...
Recent studies have shown phenotypic and metabolic heterogeneity in related species including , a typical oral commensal bacterium, , a cariogenic bacterium, and , which functions as an accessory pathogen in periodontopathic biofilm. In this study, metabolites characteristically contained in the saliva of individuals with good oral hygiene were determined, after which the effects of an identified prebiotic candidate, D-tagatose, on phenotype, gene expression, and metabolic profiles of those three key bacterial species were investigated. Examinations of the saliva metabolome of 18 systemically healthy volunteers identified salivary D-tagatose as associated with lower dental biofilm abundance in the oral cavity (Spearman's correlation coefficient; = -0.603, = 0.008), then the effects of D-tagatose on oral streptococci were analyzed . In chemically defined medium (CDM) containing D-tagatose as the sole carbohydrate source, and each showed negligible biofilm formation, whereas significant biofilms were formed in cultures of . Furthermore, even in the presence of glucose, and showed growth suppression and decreases in the final viable cell count in a D-tagatose concentration-dependent manner. In contrast, no inhibitory effects of D-tagatose on the growth of were observed. To investigate species-specific inhibition by D-tagatose, the metabolomic profiles of D-tagatose-treated , , and cells were examined. The intracellular amounts of pyruvate-derived amino acids in and , but not in , such as branched-chain amino acids and alanine, tended to decrease in the presence of D-tagatose. This phenomenon indicates that D-tagatose inhibits growth of those bacteria by affecting glycolysis and its downstream metabolism. In conclusion, the present study provides evidence that D-tagatose is abundant in saliva of individuals with good oral health. Additionally, experimental results demonstrated that D-tagatose selectively inhibits growth of the oral pathogens and . In contrast, the oral commensal seemed to be negligibly affected, thus highlighting the potential of administration of D-tagatose as an oral prebiotic for its ability to manipulate the metabolism of those targeted oral streptococci.
Topics: Biofilms; Hexoses; Humans; Prebiotics; Species Specificity; Streptococcus gordonii; Streptococcus mutans
PubMed: 34804997
DOI: 10.3389/fcimb.2021.767944 -
Dental Press Journal of Orthodontics Sep 2019The objective of this study was to formulate experimental orthodontic bracket adhesives and test their mechanical properties, fluoride release and antibacterial activity.
OBJECTIVE
The objective of this study was to formulate experimental orthodontic bracket adhesives and test their mechanical properties, fluoride release and antibacterial activity.
METHODS
Four experimental antibacterial orthodontic bracket adhesives were prepared with different compositions of synthesized antibacterial monomers replacing total 5% of dental monomers in the control Transbond XT (3M): 5%C11, 3.5%C11+1.5%C2, 5%C16, and 3.5%C16+1.5%C2. Transbond XT alone was used as control. These groups were used to bond premolar brackets to extracted premolars. Shear bond strength (SBS) was tested using an Instron machine. For antibacterial test, disk specimens (10mm diameter, 1mm thick, n=4) were fabricated and incubated with cultures of cariogenic Streptococcus mutans for 48h, and following gentle sonication, S. mutans biofilms in colony-forming-units (CFU) on the disks were enumerated by plating on agar medium. The data were analyzed using ANOVA and Tukey test (α=0.05).
RESULTS
All experimental groups had similar shear bond strength (no significant difference) to the control. All experimental groups showed significant inhibitory effect against S. mutans biofilm formation, when compared to the control, but there was no significant difference between experimental groups.
CONCLUSION
Antibacterial orthodontic adhesive can be fabricated to have similar mechanical properties but better caries-inhibitory effect than current adhesive.
Topics: Anti-Bacterial Agents; Dental Bonding; Dental Cements; Dental Stress Analysis; Materials Testing; Orthodontic Brackets; Resin Cements; Shear Strength; Streptococcus mutans
PubMed: 31508710
DOI: 10.1590/2177-6709.24.4.073-079.oar -
Applied and Environmental Microbiology Dec 2020Amino sugars, particularly glucosamine (GlcN) and -acetylglucosamine (GlcNAc), are abundant carbon and nitrogen sources supplied in host secretions and in the diet to...
Amino sugars, particularly glucosamine (GlcN) and -acetylglucosamine (GlcNAc), are abundant carbon and nitrogen sources supplied in host secretions and in the diet to the biofilms colonizing the human oral cavity. Evidence is emerging that these amino sugars provide ecological advantages to beneficial commensals over oral pathogens and pathobionts. Here, we performed transcriptome analysis on and growing in single-species or dual-species cultures with glucose, GlcN, or GlcNAc as the primary carbohydrate source. Compared to glucose, GlcN caused drastic transcriptomic shifts in each species of bacteria when it was cultured alone. Likewise, cocultivation in the presence of GlcN yielded transcriptomic profiles that were dramatically different from the single-species results from GlcN-grown cells. In contrast, GlcNAc elicited only minor changes in the transcriptome of either organism in single- and dual-species cultures. Interestingly, genes involved in pyruvate metabolism were among the most significantly affected by GlcN in both species, and these changes were consistent with measurements of pyruvate in culture supernatants. Differing from what was found in a previous report, growth of alone with GlcN inhibited the expression of multiple operons required for mutacin production. Cocultivation with consistently increased the expression of two manganese transporter operons ( and ) and decreased expression of mutacin genes in Conversely, appeared to be less affected by the presence of but did show increases in genes for biosynthetic processes in the cocultures. In conclusion, amino sugars profoundly alter the interactions between pathogenic and commensal streptococci by reprogramming central metabolism. Carbohydrate metabolism is central to the development of dental caries. A variety of sugars available to dental microorganisms influence the development of caries by affecting the physiology, ecology, and pathogenic potential of tooth biofilms. Using two well-characterized oral bacteria, one pathogen () and one commensal (), in an RNA deep-sequencing analysis, we studied the impact of two abundant amino sugars on bacterial gene expression and interspecies interactions. The results indicated large-scale remodeling of gene expression induced by GlcN in particular, affecting bacterial energy generation, acid production, protein synthesis, and release of antimicrobial molecules. Our study provides novel insights into how amino sugars modify bacterial behavior, information that will be valuable in the design of new technologies to detect and prevent oral infectious diseases.
Topics: Amino Sugars; Gene Expression; Gene Expression Profiling; Genes, Bacterial; Microbiota; Mouth; Streptococcus gordonii; Streptococcus mutans; Symbiosis
PubMed: 33097515
DOI: 10.1128/AEM.01459-20 -
Acta Crystallographica. Section D,... Sep 2021Streptococcus gordonii is a member of the viridans streptococci and is an early colonizer of the tooth surface. Adherence to the tooth surface is enabled by proteins...
Streptococcus gordonii is a member of the viridans streptococci and is an early colonizer of the tooth surface. Adherence to the tooth surface is enabled by proteins present on the S. gordonii cell surface, among which SspB belongs to one of the most well studied cell-wall-anchored adhesin families: the antigen I/II (AgI/II) family. The C-terminal region of SspB consists of three tandemly connected individual domains that display the DEv-IgG fold. These C-terminal domains contain a conserved Ca-binding site and isopeptide bonds, and they adhere to glycoprotein 340 (Gp340; also known as salivary agglutinin, SAG). Here, the structural and functional characterization of the C domain at 2.7 Å resolution is reported. Although the individual C-terminal domains of Streptococcus mutans AgI/II and S. gordonii SspB show a high degree of both sequence and structural homology, superposition of these structures highlights substantial differences in their electrostatic surface plots, and this can be attributed to the relative orientation of the individual domains (C, C and C) with respect to each other and could reflect their specificity in binding to extracellular matrix molecules. Studies further confirmed that affinity for Gp340 or its scavenger receptor cysteine-rich (SRCR) domains requires two of the three domains of C, namely C or C, which is different from AgI/II. Using protein-protein docking studies, models for this observed functional difference between C and C in their binding to SRCR are presented.
Topics: Adhesins, Bacterial; Amino Acid Sequence; Bacterial Proteins; Binding Sites; Humans; Streptococcal Infections; Streptococcus gordonii; Streptococcus mutans; Structure-Activity Relationship
PubMed: 34473090
DOI: 10.1107/S2059798321008135 -
Journal of Applied Oral Science :... 2021Fixed orthodontic appliances may lead to biofilm accumulation around them that may increase caries risk. This study aimed to evaluate the influence of quaternary...
METHODOLOGY
Fixed orthodontic appliances may lead to biofilm accumulation around them that may increase caries risk. This study aimed to evaluate the influence of quaternary ammonium methacrylates (QAMs) on the physicochemical properties, cytotoxicity, and antibacterial activity of adhesive resins for orthodontic purposes. A base resin was prepared with a comonomer blend and photoinitiator/co-initiator system. Two different QAMs were added to the base adhesive: dimethylaminododecyl methacrylate at 5 wt.% (DMADDM) or dimethylaminohexadecyl methacrylate (DMAHDM) at 10 wt.%. The base adhesive, without QAMs, (GC) and the commercial Transbond™ XT Primer 3M (GT) were used as control. The resins were tested immediately and after six months of aging in the water regarding the antibacterial activity and shear bond strength (SBS). The antibacterial activity was tested against Streptococcus mutans via metabolic activity assay (MTT test). The groups were also tested for the degree of conversion (DC) and cytotoxicity against keratinocytes.
RESULTS
The resins containing QAM showed antibacterial activity compared to the commercial material by immediately reducing the metabolic activity by about 60%. However, the antibacterial activity decreased after aging (p<0.05). None of the groups presented any differences for SBS (p>0.05) and DC (p>0.05). The incorporation of DMADDM and DMAHDM significantly reduced the keratinocyte viability compared to the GT and GC groups (p<0.05).
CONCLUSION
Both adhesives with QAMs showed a significant reduction in bacterial metabolic activity, but this effect decreased after water aging. Lower cell viability was observed for the group with the longer alkyl chain-QAM, without significant differences for the bonding ability and degree of conversion. The addition of QAMs in adhesives may affect the keratinocytes viability, and the aging effects maybe decrease the bacterial activity of QAM-doped materials.
Topics: Anti-Bacterial Agents; Biofilms; Dental Cements; Materials Testing; Methacrylates; Orthodontic Brackets; Resin Cements; Streptococcus mutans
PubMed: 33950080
DOI: 10.1590/1678-7757-2020-1031 -
Nan Fang Yi Ke Da Xue Xue Bao = Journal... Jun 2021To investigate the types of gene mutations and their distribution in clinical isolates of () and explore the association of gene mutation with the capacity of mutacin...
OBJECTIVE
To investigate the types of gene mutations and their distribution in clinical isolates of () and explore the association of gene mutation with the capacity of mutacin Ⅳ production by S. mutans.
OBJECTIVE
We assessed the capacity of mutacin Ⅳ production in 80 clinical isolates of using an inhibition zone assay. The minimum spanning tree and phylogenetic tree of these isolates were constructed using core genome multilocus sequence typing and maximum likelihood method, respectively. GeneMarkS software was used to predict the coding genes of these isolates, and the predicted genes were blasted against the gene sequence of the reference genome UA159 to determine gene mutations and their distribution characteristics in the clinical isolates. The mutation types affecting mutacin Ⅳ production were identified by analyzing the differentially distributed mutations between mutacin Ⅳ-producing isolates and mutacin Ⅳ-free isolates and by comparing the inhibition zones between isolates with gene mutations and those without mutations.
OBJECTIVE
Among the 80 clinical isolates of , 25 isolates were capable of mutacin Ⅳ production and 55 did not produce mutacin Ⅳ. The minimum spanning tree showed that the allelic differences were less among the mutacin Ⅳproducing isolates than among the mutacin Ⅳ-free isolates, and the origins of the mutacin Ⅳ-producing isolates were similar. We identified a total of 34 single base mutations in the 80 clinical isolates, and among them, C31T (=0.001), G533A ( < 0.001), C756T (=0.025), and C1036T (=0.003) showed significant differential distributions between the mutacin Ⅳ-producing and mutacin Ⅳ-free isolates. These differentially distributed mutations were positively correlated with the capacity of mutacin Ⅳ production of the bacteria.
OBJECTIVE
gene mutations that affect the capacity of mutacin Ⅳ production are present in the clinical strains of .
Topics: Bacteriocins; Mutation; Phylogeny; Streptococcus mutans
PubMed: 34238740
DOI: 10.12122/j.issn.1673-4254.2021.06.10 -
Journal of Dental Research Aug 2019resides in the oral polymicrobial biofilm and is a major contributor to the development of dental caries. Interestingly, high salivary nitrite concentrations have been...
resides in the oral polymicrobial biofilm and is a major contributor to the development of dental caries. Interestingly, high salivary nitrite concentrations have been associated with a decreased prevalence of dental caries. Moreover, the combination of hydrogen peroxide-producing oral commensal streptococci and nitrite has been shown to mediate the generation of reactive nitrogen species, which have antimicrobial activity. The goal of this study was to examine whether nitrite affects virulence during polymicrobial infections with the commensal . Here, we report that the combination of and nitrite inhibited growth and biofilm formation in vitro. Glucan production, which is critical for biofilm formation, was also inhibited in 2-species biofilms with containing nitrite as compared with biofilms that contained no nitrite. In the in vivo caries model, enamel and dentin carious lesions were significantly reduced in rats that were colonized with prior to infection with and received nitrite in the drinking water, as compared with animals that had a single infection or were co-colonized with both bacteria and received no nitrite. Last, we report that LiaS, a sensor kinase of the LiaFSR 3-component system, mediates resistance to nitrosative stress. In summary, our data demonstrate that commensal streptococci and nitrite provide protection against pathogenesis. Modulating nitrite concentrations in the oral cavity could be a useful strategy to combat the prevalence of dental caries.
Topics: Animals; Biofilms; Coinfection; Dental Caries; Diet; Microbiota; Nitrites; Random Allocation; Rats; Rats, Inbred F344; Streptococcus; Streptococcus mutans; Symbiosis
PubMed: 31219733
DOI: 10.1177/0022034519855348 -
Frontiers in Cellular and Infection... 2021The present cross-sectional study investigated whether Firmicutes (F) and Bacteroidetes (B) levels in the mouth reflected the gut condition in obesity and early...
The present cross-sectional study investigated whether Firmicutes (F) and Bacteroidetes (B) levels in the mouth reflected the gut condition in obesity and early childhood caries (ECC). Eighty preschoolers (3-5 years) were equally assigned into four groups: 1. obese + ECC, 2. obese + caries-free (CF), 3. eutrophic + ECC, and 4. eutrophic + CF. Nutritional status and ECC were assessed based on the WHO criteria. Dental biofilm and fecal samples were collected for F and B quantification using RT-PCR analysis. Data were evaluated using three-way-ANOVA and Pearson's correlation (α = 0.05). Regardless of the anatomical location effect ( = 0.22), there were higher values for F in the obese children + ECC compared with those in obese + caries-free (CF) in both mouth and gut ( < 0.05). The correlation for F at these sites was negative in obese children + ECC (r = -0.48; = 0.03) and positive in obese children + CF (r=0.50; = 0.03). Bacteroidetes were influenced by ECC ( = 0.03) and the anatomical location ( = 0.00), and the levels tended to be higher in the mouth of the obese children + ECC ( = 0.04). The F/B ratio was higher in the gut and was affected by the anatomical location ( = 0.00). This preliminary study suggested that modulated by ECC, counts of oral Firmicutes reflected corresponding condition in the gut of obese preschoolers. In addition, we first evidenced that the Firmicutes phylum behave differently according to the nutritional status and caries experience and that supragingival biofilm and gut could share levels of similarity.
Topics: Child; Child, Preschool; Cross-Sectional Studies; Dental Caries; Dental Caries Susceptibility; Firmicutes; Humans; Obesity; Streptococcus mutans
PubMed: 34123864
DOI: 10.3389/fcimb.2021.593734