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Australian Dental Journal Dec 2019Restorative materials have varying surface characteristics from natural tooth, which may affect oral-bacterial surface attachment/growth. This study examined 48-h...
BACKGROUND
Restorative materials have varying surface characteristics from natural tooth, which may affect oral-bacterial surface attachment/growth. This study examined 48-h Streptococcus mutans (Sm) or Actinomyces naeslundii (An) growth on various restorative materials and tooth surfaces.
METHODS
The quantity and viability of 48-hour-old Sm and An growth on polished (180- or 1200-grits), saliva-coated resin composite (RC), glass ionomer cements (GIC), resin-modified GIC (R-GIC), GIC containing casein phosphopeptide-amorphous calcium phosphate (3% (w/w), CPP-ACP GIC), amalgam or tooth blocks (5 × 5 × 1 mm ) were examined.
RESULTS
Rough-polished (arithmetical mean deviation of the assessed surface roughness profile (Ra): 1.50-1.75 µm) material surfaces revealed relatively higher proportion of inorganic, positively charged surface components ((Si + Al)/C) and greater quantity of surface attached bacteria than smooth polished (Ra: 0.20-0.35 µm) material groups (P < 0.001). Less Sm and An were observed on tooth, and smooth polished GIC and CPP-ACP GIC surfaces than on resin-based materials (RC, R-GIC) and amalgam (P ≤ 0.003). Viability of Sm was found to be lower on amalgam surfaces (P < 0.001), whereas that of An appeared lower on both amalgam surfaces and rough CPP-ACP GIC surfaces (P ≤ 0.033).
CONCLUSION
Surface roughness exerted a pronounced effect on in vitro growth/attached Sm/An quantity but may not have an impact on bacteria viability. Interestingly, despite smoother surfaces of various materials tested, fewer Sm/An were observed attaching on tooth surfaces.
Topics: Actinomyces; Composite Resins; Dental Materials; Glass Ionomer Cements; Humans; Materials Testing; Streptococcus mutans; Surface Properties
PubMed: 31442307
DOI: 10.1111/adj.12715 -
International Journal of Systematic and... Mar 2009Actinomyces naeslundii is an important early colonizer in the oral biofilm and consists of three genospecies (1, 2 and WVA 963) which cannot be readily differentiated...
Emended description of Actinomyces naeslundii and descriptions of Actinomyces oris sp. nov. and Actinomyces johnsonii sp. nov., previously identified as Actinomyces naeslundii genospecies 1, 2 and WVA 963.
Actinomyces naeslundii is an important early colonizer in the oral biofilm and consists of three genospecies (1, 2 and WVA 963) which cannot be readily differentiated using conventional phenotypic testing or on the basis of 16S rRNA gene sequencing. We have investigated a representative collection of type and reference strains and clinical and oral isolates (n=115) and determined the partial gene sequences of six housekeeping genes (atpA, rpoB, pgi, metG, gltA and gyrA). These sequences identified the three genospecies and differentiated them from Actinomyces viscosus isolated from rodents. The partial sequences of atpA and metG gave best separation of the three genospecies. A. naeslundii genospecies 1 and 2 formed two distinct clusters, well separated from both genospecies WVA 963 and A. viscosus. Analysis of the same genes in other oral Actinomyces species (Actinomyces gerencseriae, A. israelii, A. meyeri, A. odontolyticus and A. georgiae) indicated that, when sequence data were obtained, these species each exhibited <90 % similarity with the A. naeslundii genospecies. Based on these data, we propose the name Actinomyces oris sp. nov. (type strain ATCC 27044(T) =CCUG 34288(T)) for A. naeslundii genospecies 2 and Actinomyces johnsonii sp. nov. (type strain ATCC 49338(T) =CCUG 34287(T)) for A. naeslundii genospecies WVA 963. A. naeslundii genospecies 1 should remain as A. naeslundii sensu stricto, with the type strain ATCC 12104(T) =NCTC 10301(T) =CCUG 2238(T).
Topics: Actinomyces; Actinomycosis; Animals; Bacterial Proteins; Bacterial Typing Techniques; Blood; Cerebrospinal Fluid; DNA, Bacterial; Humans; Molecular Sequence Data; Mouth; Phenotype; Plague; Sequence Analysis, DNA; Species Specificity
PubMed: 19244431
DOI: 10.1099/ijs.0.000950-0 -
Heliyon Feb 2021Surface pre-reacted glass-ionomer (S-PRG) fillers release antibacterial borate and fluoride ions. We fabricated nanoscale S-PRG fillers (S-PRG nanofillers) for...
OBJECTIVES
Surface pre-reacted glass-ionomer (S-PRG) fillers release antibacterial borate and fluoride ions. We fabricated nanoscale S-PRG fillers (S-PRG nanofillers) for antibacterial coating of tooth surfaces and assessed the antibacterial effects of this coating in vitro. In addition, we creating a canine model of periodontitis to evaluate the effectiveness of S-PRG nanofiller application on tooth roots and improvement of periodontal parameters.
METHODS
Human dentin blocks were coated with S-PRG nanofiller (average particle size: 0.48 μm) and then characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDX), and ion-releasing test. Antibacterial effects of dentin blocks coated with S-PRG nanofiller were examined using bacterial strains, and Next, we created an experimental model of periodontitis in furcation of premolars of beagle dogs. Then, S-PRG nanofiller coating was applied onto exposed tooth root surfaces. Periodontal parameters, gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL), were measured from baseline until 4 weeks. In addition, bone healing was radiographically and histologically examined.
RESULTS
SEM and EDX revealed that S-PRG nanofillers uniformly covered the dentin surface after coating. Dentin blocks coated with S-PRG nanofiller showed ion-releasing property, bacterial growth inhibition, and sterilization effects. In the experimental periodontitis model, S-PRG nanofiller coating significantly reduced clinical inflammatory parameters, such as GI (P < 0.01) and BOP (P < 0.05), compared to uncoated samples. In addition, PPD and CAL significantly decreased by S-PRG nanofiller coating (2 weeks: P < 0.05; 3 and 4 weeks: P < 0.01), suggesting the improvement of periodontitis. Micro-CT and histology revealed that bone healing of furcation defects was enhanced by S-PRG nanofiller coating.
CONCLUSION
S-PRG nanofiller coating provides antibacterial effects to tooth surfaces and improves clinical parameters of periodontitis.
PubMed: 33644453
DOI: 10.1016/j.heliyon.2021.e06147 -
Journal of Oral Microbiology 2018: Dental caries results from a dysbiosis of tooth-associated biofilms and frequently extends through enamel into dentin which has a different structure and composition....
: Dental caries results from a dysbiosis of tooth-associated biofilms and frequently extends through enamel into dentin which has a different structure and composition. : To evaluate the metatranscriptome of caries to determine the metabolic potential of caries communities compared with health. : Samples from children, caries-free (CF: = 4) or with coronal (CC: = 5) or dentin (DC: = 5) caries were examined for gene expression potential. Functional profiling was performed using HUMAnN2 (HMP Unified Metabolic Analysis Network). : There was increased gene expression diversity in DC compared with CC and CF. Genes in CF included alcohol dehydrogenase from , methylenetetrahydrofolate reductase from and choline kinase from streptococci. Genes in CC mapped mainly to . Arginine deiminase in DC mapped to and . Glycerol kinase genes mapped to in all groups whereas glycerol kinase in DC were from and streptococci. Uracil-DNA glycosylase in DC mapped to and . Repressor LexA in DC mapped to and . : Functional profiling revealed enzyme activities in both caries and caries-free communities and clarified marked differences between coronal and dentin caries in bacterial composition and potential gene expression.
PubMed: 30034639
DOI: 10.1080/20002297.2018.1495976 -
International Journal of Molecular... Nov 2022This study was aimed at engineering photocrosslinkable azithromycin (AZ)-laden gelatin methacryloyl fibers via electrospinning to serve as a localized and biodegradable...
This study was aimed at engineering photocrosslinkable azithromycin (AZ)-laden gelatin methacryloyl fibers via electrospinning to serve as a localized and biodegradable drug delivery system for endodontic infection control. AZ at three distinct amounts was mixed with solubilized gelatin methacryloyl and the photoinitiator to obtain the following fibers: GelMA+5%AZ, GelMA+10%AZ, and GelMA+15%AZ. Fiber morphology, diameter, AZ incorporation, mechanical properties, degradation profile, and antimicrobial action against and were also studied. In vitro compatibility with human-derived dental pulp stem cells and inflammatory response in vivo using a subcutaneous rat model were also determined. A bead-free fibrous microstructure with interconnected pores was observed for all groups. GelMA and GelMA+10%AZ had the highest fiber diameter means. The tensile strength of the GelMA-based fibers was reduced upon AZ addition. A similar pattern was observed for the degradation profile in vitro. GelMA+15%AZ fibers led to the highest bacterial inhibition. The presence of AZ, regardless of the concentration, did not pose significant toxicity. In vivo findings indicated higher blood vessel formation, mild inflammation, and mature and thick well-oriented collagen fibers interweaving with the engineered fibers. Altogether, AZ-laden photocrosslinkable GelMA fibers had adequate mechanical and degradation properties, with 15%AZ displaying significant antimicrobial activity without compromising biocompatibility.
Topics: Rats; Humans; Animals; Azithromycin; Hydrogels; Gelatin; Infection Control
PubMed: 36430238
DOI: 10.3390/ijms232213761 -
Microorganisms Aug 2023Acne vulgaris is a common inflammatory condition that is multi-factorial and impacted by both intrinsic and extrinsic features. Several previous studies have assessed...
Acne vulgaris is a common inflammatory condition that is multi-factorial and impacted by both intrinsic and extrinsic features. Several previous studies have assessed for correlations between factors such as circulating hormones, stress, or the microbiome. However, there have not been any correlations specifically against lesion counts or differentiating correlations between inflammatory and non-inflammatory lesion counts. Here, we correlate several factors against acne lesions. Twenty men and women with mild to moderate acne were recruited, and their hormonal levels and their gut microbiome were collected and correlated against their inflammatory and non-inflammatory lesions of acne. Facial non-inflammatory lesions were weakly correlated to sebum excretion rate and weakly inversely correlated to forehead and cheek hydration. We examined stress through the use of a normalized peak-to-trough ratio (higher numbers indicated less stress), which correlated with skin hydration and inversely correlated with sebum excretion rate. Sebum excretion rate was weakly correlated to testosterone levels, and facial hydration correlated with estradiol levels. Correlations with the gut microbiome showed differential correlations with inflammatory and non-inflammatory lesions, with correlating to inflammatory lesion counts, while correlated to non-inflammatory lesions. Overall, measures of stress and circulating hormones correlate to skin biophysical properties and acne lesion counts. Also, different gut bacteria correlate with either inflammatory or non-inflammatory lesion counts. We hope that our findings stimulate further work on the gut-mind-stress-skin axis within acne.
PubMed: 37630609
DOI: 10.3390/microorganisms11082049 -
Applied Microbiology Sep 1969Typical actinomycosis has been produced in mice following single intraperitoneal injections of saline suspensions of Actinomyces israelii and A. naeslundii. A. israelii...
Typical actinomycosis has been produced in mice following single intraperitoneal injections of saline suspensions of Actinomyces israelii and A. naeslundii. A. israelii produced infections in 95.8% of the animals inoculated. A. naeslundii, generally considered to be a saprophytic organism, produced lesions in 89.7% of the inoculated animals. The finding that A. naeslundii produced lesions in mice similar to those produced by A. israelii suggests that A. naeslundii has similar pathogenic potential for man. The isolation of A. naeslundii from suppurative lesions of man also supports this conclusion.
Topics: Actinomyces; Actinomycosis; Animals; Injections, Intraperitoneal; Liver; Lung; Male; Mice; Spleen
PubMed: 5373677
DOI: 10.1128/am.18.3.427-432.1969 -
Infection and Immunity Feb 1999Ammonia production from urea by ureolytic oral bacteria is believed to have a significant impact on oral health and the ecological balance of oral microbial populations....
Ammonia production from urea by ureolytic oral bacteria is believed to have a significant impact on oral health and the ecological balance of oral microbial populations. In this study we cloned and characterized the urease gene cluster of Actinomyces naeslundii, which is one of the pioneer organisms in the oral cavity and a significant constituent of supragingival and subgingival dental plaque in children and adults. An internal fragment of the ureC gene of A. naeslundii WVU45 was initially amplified by PCR with degenerate primers derived from conserved amino acid sequences of the large catalytic subunit of urease in bacteria and plants. The PCR product was then used as a probe to identify recombinant bacteriophages carrying the A. naeslundii urease gene cluster and roughly 30 kbp of flanking DNA. Nucleotide sequence analysis demonstrated that the gene cluster was comprised of seven contiguously arranged open reading frames with significant homologies at the protein and nucleotide sequence levels to the ureABCEFGD genes from other organisms. By using primer extension, a putative transcription initiation site was mapped at 66 bases 5' to the start codon of ureA. A urease-deficient strain was constructed by insertion of a kanamycin resistance determinant within the ureC gene via allelic replacement. In contrast to the wild-type organism, the isogenic mutant was unable to grow in a semidefined medium supplemented with urea as the nitrogen source and was not protected by the addition of urea against killing in moderately acidic environments. These data indicated that urea can be effectively utilized as a nitrogen source by A. naeslundii via a urease-dependent pathway and that ureolysis can protect A. naeslundii against environmental acidification at physiologically relevant pH values. Therefore, urease could confer to A. naeslundii critical selective advantages over nonureolytic organisms in dental plaque, constituting an important determinant of plaque ecology.
Topics: Actinomyces; Base Sequence; Binding Sites; Chromosome Mapping; DNA Primers; DNA, Bacterial; Humans; Molecular Sequence Data; Multigene Family; Sequence Analysis, DNA; Transcription, Genetic; Urease
PubMed: 9916052
DOI: 10.1128/IAI.67.2.504-512.1999 -
Restorative Dentistry & Endodontics May 2021The aim of this study was to evaluate bacterial nanocellulose (BNC) membranes incorporated with antimicrobial agents regarding cytotoxicity in fibroblasts of the...
OBJECTIVES
The aim of this study was to evaluate bacterial nanocellulose (BNC) membranes incorporated with antimicrobial agents regarding cytotoxicity in fibroblasts of the periodontal ligament (PDLF), antimicrobial activity, and inhibition of multispecies biofilm formation.
MATERIALS AND METHODS
The tested BNC membranes were BNC + 1% clindamycin (BNC/CLI); BNC + 0.12% chlorhexidine (BNC/CHX); BNC + nitric oxide (BNC/NO); and conventional BNC (BNC; control). After PDLF culture, the BNC membranes were positioned in the wells and maintained for 24 hours. Cell viability was then evaluated using the MTS calorimetric test. Antimicrobial activity against , , and () was evaluated using the agar diffusion test. To assess the antibiofilm activity, BNC membranes were exposed for 24 hours to the mixed culture. After sonicating the BNC membranes to remove the remaining biofilm and plating the suspension on agar, the number of colony-forming units (CFU)/mL was determined. Data were analyzed by 1-way analysis of variance and the Tukey, Kruskal-Wallis, and Dunn tests (α = 5%).
RESULTS
PDLF metabolic activity after contact with BNC/CHX, BNC/CLI, and BNC/NO was 35%, 61% and 97%, respectively, compared to BNC. BNC/NO showed biocompatibility similar to that of BNC ( = 0.78). BNC/CLI showed the largest inhibition halos, and was superior to the other BNC membranes against ( < 0.05). The experimental BNC membranes inhibited biofilm formation, with about a 3-fold log CFU reduction compared to BNC ( < 0.05).
CONCLUSIONS
BNC/NO showed excellent biocompatibility and inhibited multispecies biofilm formation, similarly to BNC/CLI and BNC/CHX.
PubMed: 34123756
DOI: 10.5395/rde.2021.46.e20 -
FEMS Microbiology Ecology Dec 2008In dental plaque alpha-haemolytic streptococci, including Streptococcus gordonii, are considered beneficial for oral health. These organisms produce hydrogen peroxide...
In dental plaque alpha-haemolytic streptococci, including Streptococcus gordonii, are considered beneficial for oral health. These organisms produce hydrogen peroxide (H(2)O(2)) at concentrations sufficient to kill many oral bacteria. Streptococci do not produce catalase yet tolerate H(2)O(2). We recently demonstrated that coaggregation with Actinomyces naeslundii stabilizes arginine biosynthesis in S. gordonii. Protein arginine residues are sensitive to oxidation by H(2)O(2). Here, the ability of A. naeslundii to protect S. gordonii against self-produced H(2)O(2) was investigated. Coaggregation with A. naeslundii enabled S. gordonii to grow in the absence of arginine, and promoted survival of S. gordonii following growth with or without added arginine. Arginine-replete S. gordonii monocultures contained 20-30 microM H(2)O(2) throughout exponential growth. Actinomyces naeslundii did not produce H(2)O(2) but synthesized catalase, removed H(2)O(2) from coaggregate cultures and decreased protein oxidation in S. gordonii. On solid medium, S. gordonii inhibited growth of A. naeslundii; exogenous catalase overcame this inhibition. In coaggregate cultures, A. naeslundii cell numbers were >90% lower than in monocultures after 24 h. These results indicate that coaggregation with A. naeslundii protects S. gordonii from oxidative damage. However, high cell densities of S. gordonii inhibit A. naeslundii. Therefore, H(2)O(2) may drive these organisms towards an ecologically balanced community in natural dental plaque.
Topics: Actinomyces; Anti-Bacterial Agents; Bacterial Adhesion; Bacterial Proteins; Biofilms; Dental Plaque; Ecosystem; Hydrogen Peroxide; Oxidants; Oxidation-Reduction; Streptococcus gordonii; Survival Analysis
PubMed: 18785881
DOI: 10.1111/j.1574-6941.2008.00585.x