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Archives of Oral Biology Apr 2019How the interactions between Candida albicans and Actinomyces viscosus contributed to the root caries was not clear. This study aimed to investigate their cross-kingdom...
OBJECTIVE
How the interactions between Candida albicans and Actinomyces viscosus contributed to the root caries was not clear. This study aimed to investigate their cross-kingdom interactions on the biomass and the cariogenic virulence in dual-species biofilms.
DESIGN
Suspensions of C. albicans and A. viscosus were formed the mono and polymicrobial biofilms in vitro. Crystal violet assay, viable plate count, scanning electron microscopy and fluorescence in situ hybridization were used to analyze the biomass and biofilm structure. Glycolytic pH drop and the spectrophotometric method were used to evaluate the acid production and hydroxyapatite dissolution, respectively. The exopolysaccharide production was measured by the anthrone-sulfuric acid method, while the adhesion force was measured by atomic force microscopy.
RESULTS
The biomass and colony-forming units of mixed-species were significantly increased compared to that of the mono-species at 24 h, 48 h, 72 h. The structure of dual-species biofilm had more microcolonies and was much denser. The dual-species biofilms significantly decreased the pH value and damaged the hydroxyapatite compared with the mono-species biofilms at various time points, indicating the strong cariogenic virulence. Moreover, the dual-species biofilms significantly enhanced the exopolysaccharide production and adhesion force suggesting the increase of biofilm adhesion.
CONCLUSIONS
Cross-kingdom interactions of C. albicans and A. viscosus significantly elevated the biomass and cariogenic virulence of dual-species biofilm.
Topics: Actinomyces viscosus; Biofilms; Candida albicans; Dental Caries; In Situ Hybridization, Fluorescence; Microbial Interactions; Virulence
PubMed: 30822704
DOI: 10.1016/j.archoralbio.2019.02.008 -
Medicina (Kaunas, Lithuania) Oct 2021: species are part of the normal flora of humans and rarely cause disease. It is an uncommon cause of disease in humans. The clinical features of actinomycosis have...
: species are part of the normal flora of humans and rarely cause disease. It is an uncommon cause of disease in humans. The clinical features of actinomycosis have been described, and various anatomical sites (such as face, bones and joints, respiratory tract, genitourinary tract, digestive tract, central nervous system, skin, and soft tissue structures) can be affected. It is not easy to identify actinomycosis because it sometimes mimics cancer due to under-recognition. As new diagnostic methods have been applied, can now more easily be identified at the species level. Recent studies have also highlighted differences among species. We report a case of bacteremia with cutaneous actinomycosis. : A 66 years old male developed fever for a day with progressive right lower-leg erythematous swelling. Blood culture isolates yielded species, which was identified as by sequencing of the 16S rRNA gene. In addition, we searched for the term or actinomycosis cross-referenced with bacteremia or "blood culture" or "blood stream" from January 2010 to July 2020. The infectious diseases caused by species of from January 1977 to July 2020 were also reviewed. : The patient recovered well after intravenous ampicillin treatment. Poor oral hygiene was confirmed by dental examination. There were no disease relapses during the following period. Most cases of actinomycosis can be treated with penicillin. However, clinical alertness, risk factor evaluation, and identification of species can prevent inappropriate antibiotic or intervention. We also compiled a total of 18 cases of bacteremia after conducting an online database search. : In summary, we describe a case of fever and progressive cellulitis. species was isolated from blood culture, which was further identified as by 16S rRNA sequencing. The cellulitis improved after pathogen-directed antibiotics. Evaluation of risk factors in patients with bacteremia and further identification of the species are recommended for successful treatment.
Topics: Actinomyces; Actinomyces viscosus; Actinomycosis; Aged; Bacteremia; Humans; Male; RNA, Ribosomal, 16S
PubMed: 34684101
DOI: 10.3390/medicina57101064 -
Advances in Dental Research Feb 2018A genome-wide transcriptional analysis was performed to elucidate the bacterial cellular response of Streptococcus mutans and Actinomyces viscosus to NaF and SnF. The...
A genome-wide transcriptional analysis was performed to elucidate the bacterial cellular response of Streptococcus mutans and Actinomyces viscosus to NaF and SnF. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of SnF were predetermined before microarray study. Gene expression profiling microarray experiments were carried out in the absence (control) and presence (experimental) of 10 ppm and 100 ppm Sn (in the form of SnF) and fluoride controls for 10-min exposures (4 biological replicates/treatment). These Sn levels and treatment time were chosen because they have been shown to slow bacterial growth of S. mutans (10 ppm) and A. viscosus (100 ppm) without affecting cell viability. All data generated by microarray experiments were analyzed with bioinformatics tools by applying the following criteria: 1) a q value should be ≤0.05, and 2) an absolute fold change in transcript level should be ≥1.5. Microarray results showed SnF significantly inhibited several genes encoding enzymes of the galactose pathway upon a 10-min exposure versus a negative control: lacA and lacB (A and B subunits of the galactose-6-P isomerase), lacC (tagatose-6-P kinase), lacD (tagatose-1,6-bP adolase), galK (galactokinase), galT (galactose-1-phosphate uridylyltransferase), and galE (UDP-glucose 4-epimerase). A gene fruK encoding fructose-1-phosphate kinase in the fructose pathway was also significantly inhibited. Several genes encoding fructose/mannose-specific enzyme IIABC components in the phosphotransferase system (PTS) were also downregulated, as was ldh encoding lactate dehydrogenase, a key enzyme involved in lactic acid synthesis. SnF downregulated the transcription of most key enzyme genes involved in the galactose pathway and also suppressed several key genes involved in the PTS, which transports sugars into the cell in the first step of glycolysis.
Topics: Actinomyces viscosus; Gene Expression Profiling; Genes, Bacterial; Microarray Analysis; Microbial Sensitivity Tests; RNA, Messenger; Sodium Fluoride; Streptococcus mutans; Tin Fluorides
PubMed: 29355427
DOI: 10.1177/0022034517737027 -
International Journal of Antimicrobial... Jun 2019Candida albicans and Actinomyces viscosus are prominent microbes associated with dental root caries. The aim of this study was to investigate the effect of C. albicans...
Candida albicans and Actinomyces viscosus are prominent microbes associated with dental root caries. The aim of this study was to investigate the effect of C. albicans on A. viscosus biofilms and to identify the mechanisms associated with this interaction. A. viscosus and C. albicans strains (wide-type and mutants) were used to form biofilms in vitro and in vivo, which were subsequently analysed by crystal violet assay and scanning electron microscopy (SEM) to investigate the effect of C. albicans on A. viscosus growth. A viable plate count and survival curve for C. albicans mutants and A. viscosus combinations were used to identify which C. albicans pathway was crucial for cross-kingdom interactions. Voriconazole was used to block their interactions both in vitro and in vivo. SEM, fluorescence in situ hybridisation (FISH), quantitative PCR and survival curve analyses were performed to evaluate the activity of voriconazole on C. albicans and A. viscosus interactions. The biomass and virulence of mixed-species biofilms were significantly enhanced compared with the A. viscosus biofilm alone. However, this was not observed in the mixed-species biofilms with the C. albicans mutant erg11Δ/Δ in vitro and in vivo, indicating that azoles may work on the mixed-species biofilms. As expected, voriconazole can effectively reduce the biomass of mixed-species biofilms. A high concentration of voriconazole (1 µg/mL) reduced the abundance of C. albicans, whilst a low voriconazole concentration (0.25 µg/mL) blocked their interactions similar to the effect of the erg11Δ/Δ mutant. Voriconazole may be a candidate strategy to combat root caries pathogens.
Topics: Actinomyces viscosus; Animals; Antifungal Agents; Biofilms; Candida albicans; Ergosterol; Gentian Violet; Humans; In Situ Hybridization, Fluorescence; Metabolic Networks and Pathways; Microbial Interactions; Microbial Viability; Microscopy, Electron, Scanning; Provitamins; Staining and Labeling; Voriconazole
PubMed: 30818001
DOI: 10.1016/j.ijantimicag.2019.02.010 -
Frontiers in Bioengineering and... 2022Peri-implantitis is the leading cause of dental implant failure, initially raised by biofilm accumulation on the implant surface. During the development of biofilm, ()...
Peri-implantitis is the leading cause of dental implant failure, initially raised by biofilm accumulation on the implant surface. During the development of biofilm, () plays a pivotal role in initial attachment as well as the bacterial coaggregation of multispecies pathogens. Hence, eliminating the -associated biofilm is fundamental for the regeneration of the lost bone around implants. Whereas clinical evidence indicated that antimicrobials and debridement did not show significant effects on the decontamination of biofilm on the implant surface. In this study, alpha-amylase was investigated for its effects on disassembling biofilm. Then, in order to substantially disperse biofilm under biosafety concentration, D-arginine was employed to appraise its enhancing effects on alpha-amylase. In addition, molecular dynamics simulations and molecular docking were conducted to elucidate the mechanism of D-arginine enhancing alpha-amylase. 0.1-0.5% alpha-amylase showed significant effects on disassembling biofilm, with definite cytotoxicity toward MC3T3-E1 cells meanwhile. Intriguingly, 8 mM D-arginine drastically enhanced the eradication of biofilm biomass by 0.01% alpha-amylase with biosafety in 30 min. The exopolysaccharides of biofilm were also thoroughly hydrolyzed by 0.01% alpha-amylase with 8 mM D-arginine. The biofilm thickness and integrity were disrupted, and the exopolysaccharides among the extracellular matrix were elusive. Molecular dynamics simulations showed that with the hydrogen bonding of D-arginine to the catalytic triad and calcium-binding regions of alpha-amylase, the atom fluctuation of the structure was attenuated. The distances between catalytic triad were shortened, and the calcium-binding regions became more stable. Molecular docking scores revealed that D-arginine facilitated the maltotetraose binding process of alpha-amylase. In conclusion, these results demonstrate that D-arginine enhances the disassembly effects of alpha-amylase on biofilm through potentiating the catalytic triad and stabilizing the calcium-binding regions, thus providing a novel strategy for the decontamination of biofilm contaminated implant surface.
PubMed: 35309977
DOI: 10.3389/fbioe.2022.864012 -
Journal of Dental Sciences Mar 2016The co-operative effect of exogenous dextranase (Dex) and sodium fluoride (NaF) on monospecies biofilms is impressive. Here we investigated the effects of the...
BACKGROUND/PURPOSE
The co-operative effect of exogenous dextranase (Dex) and sodium fluoride (NaF) on monospecies biofilms is impressive. Here we investigated the effects of the combination on a mature cariogenic multispecies biofilm and analyzed the potential mechanism.
MATERIALS AND METHODS
A multispecies biofilm of , , and was established . Dex and NaF were added separately or together. The effects of the agents on the biomass were measured. The exopolysaccharide production was determined with the scintillation counting method. The viability and morphology were evaluated using colony forming unit and confocal laser scanning microscopy, respectively.
RESULTS
In general, biofilms treated with Dex and a little concentration of NaF exhibited a lower biomass, exopolysaccharide production, and viability compared with the control group (P < 0.05). Confocal laser scanning microscopy using a vital fluorescence technique showed the combination treated biofilms appeared to be loose relatively and single cells could be observed. Furthermore, the thickness and viability were also lower than either of the separate agent groups (P < 0.05).
CONCLUSION
Overall, these findings reveal that a combination of 1 U/mL Dex and 80 μg/mL NaF is a promising candidate for disrupting complex cariogenic multispecies biofilms. This feature may be in that Dex loses the structure of biofilms, thereby facilitating NaF penetration and enhancing its antibacterial effects.
PubMed: 30894944
DOI: 10.1016/j.jds.2015.08.001 -
Annals of Medicine and Surgery (2012) Sep 2022The present study aims to study antibacterial effects and cellular mechanisms of iron oxide magnetic nanoparticles loaded with piroctone olamine (Fe3O4@PO NPs) against...
BACKGROUND
The present study aims to study antibacterial effects and cellular mechanisms of iron oxide magnetic nanoparticles loaded with piroctone olamine (Fe3O4@PO NPs) against some cariogenic bacteria ( and
METHODS
Nanoparticles was synthesized by the coprecipitation method. Antibacterial effects of Fe3O4@PO NPs were performed by calculating the minimum inhibitory concentration (MIC). We also evaluated the level of reactive oxygen species (ROS) and protein leakage to assess whether antibacterial effects may be dependent on these mechanisms.
RESULTS
The results demonstrated that PO showed the lowest antibacterial effect compared to other drugs tested with MICs values of 53.33 and 64 μg/ml for and , respectively. In contrast, the highest antibacterial effect was related to Fe3O4@PONPs with MICs values of 2.66 and 3.33 μg/ml for and , respectively. Fe3O4@PONPs, Fe3O4MNP, and PO markedly increased (p < 0.001) ROS production and protein leakage of tested bacteria at ≥¼ MIC, ≥1/3 MIC, and ½ MIC, respectively.
CONCLUSION
The findings of the present survey revealed the promising antibacterial effects of Fe3O4@PONP against some cariogenic bacteria; whereas it triggered the ROS production and protein leakage as the possible antibacterial mode of action of anti-infective agents. However, additional surveys are necessary to elucidate the accurate mechanisms of these nanoparticles.
PubMed: 36147164
DOI: 10.1016/j.amsu.2022.104291 -
Journal of Oral and Maxillofacial... 2019The Ayurvedic system of medicine is popular in India and has gone through various change and remains as the mainstay of medical relief to a large population. Dental...
INTRODUCTION
The Ayurvedic system of medicine is popular in India and has gone through various change and remains as the mainstay of medical relief to a large population. Dental caries is the one of the major issue in the recent time, and there is no definite caries prevention method so far apart from Topical fluoride application, regular oral hygiene measures, pit and fissure sealants and diet measure. In spite of the above mentioned preventive measures the people are still prone to dental caries. In order to find a better solution the present study evaluates the antimicrobial properties widely available and cost effective herbal extracts of Solanum xanthocarpum and Pistacia lentiscus extract on cariogenic oral microbial flora.
AIM
To Evaluate the Antimicrobial properties of Solanum xanthocarpum and Pistacia lentiscus extracts on cariogenic oral microbial flora.
METHODOLOGY
The antimicrobial properties of Solanum xanthocarpum and Pistacia lentiscus extracts on cariogenic oral microbial flora (streptococcus mutans, lactobacillus, actinomyces viscosus) by different culture techniques to estimate the zone of inhibition (well diffusion method) and minimum inhibitory concentration (tube dilution method).
RESULTS
The antimicrobial efficacy of Solanum xanthocarpum and Pistacia lentiscus on test bacteria were analysed using kurskal wallis test and values of 0.003 and 0.002 were obtained respectively, since the values were less than 0.005, indicating that both herbal products possess statistically significant antimicrobial properties.
CONCLUSION
The antimicrobial effects of the herbal extracts were almost on par with commercially available allopathic agents like chlorhexidine on oral cariogenic microbes. The efficacy should be further validated in a large scale studies and can be utilized for caries prevention in the form of mouth rinses, dentifrices and topical application in the future.
PubMed: 31942118
DOI: 10.4103/jomfp.JOMFP_30_19 -
Anaerobe Jun 2022Obligate and facultative anaerobic bacteria adhering to dental implants are a major cause for peri-implant inflammation, which, if left untreated, can lead to implant...
OBJECTIVES
Obligate and facultative anaerobic bacteria adhering to dental implants are a major cause for peri-implant inflammation, which, if left untreated, can lead to implant loss. Previously, our group developed a new route for the synthesis of isoeugenol-functionalized aqueous nanogels for implant coatings.
METHODS
Here, the antimicrobial activity of several new nanogels differing in spacer length (n = 6, 9, 44), radius (60-200 nm), and amount of isoeugenol functional substance (1-20 mol%) was tested against the following peri-implantitis-associated species: Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Aggregatibacter actinomycetemcomitans, Escherichia coli, Actinomyces viscosus, Enterococcus faecalis, Staphylococcus aureus, Streptococcus oralis, S. parasanguinis, and the yeast Candida albicans. The minimal bactericidal concentration (MBC) and fungicidal concentration (MFC) were determined for each combination. In addition, transmission electron microscopy (TEM) and fluorescence microscopy after live-dead-staining (LD-S) were performed to visualize nanogel-microbe interactions.
RESULTS
Two nanogels, NG9-3 and NG9-4 (colloids of 80-150 nm, with a spacer length of n = 9 and feeding between 5 and 10 mol% isoeugenol), had an inhibitory effect on all Gram-positive species and on P. gingivalis and P. intermedia with MBC ≥31.25 μg/ml. TEM and LD-S images showed that cellular adhesion and uptake of nanogels resulted in swelling, shedding, or even complete detachment of the cell wall and then to bursting (see graphical abstract).
CONCLUSIONS
Functional nanogels can be used as building blocks in the design of bioactive coatings on implants to prevent infection and accelerate tissue regeneration, but the concentrations required are higher than for antibiotics.
Topics: Aggregatibacter actinomycetemcomitans; Dental Implants; Eugenol; Humans; Nanogels; Peri-Implantitis; Porphyromonas gingivalis; Prevotella intermedia
PubMed: 35367366
DOI: 10.1016/j.anaerobe.2022.102552 -
Frontiers in Microbiology 2022To investigate the degradation effect of bovine trypsin on multispecies biofilm of periodontitis-related bacteria and to provide an experimental reference for exploring...
To investigate the degradation effect of bovine trypsin on multispecies biofilm of periodontitis-related bacteria and to provide an experimental reference for exploring new methods for controlling biofilms of periodontitis-related microorganisms, the multispecies biofilm of periodontitis-related microorganisms was established. Standard strains of subsp. , , and were co-cultured to form the biofilm. The experimental groups were treated with bovine trypsin, distilled water was applied as the blank control group, and phosphate saline buffer (pH = 7.4) as the negative control group. Morphological observation and quantitative analysis of extracellular polymeric substances (EPS), live bacteria, and dead bacteria were conducted using a laser confocal microscope. The morphological changes of EPS and bacteria were also observed using a scanning electron microscope. The results of morphological observations of modeling were as follows. EPS aggregated as agglomerates, and bacteria flora were wrapped by them, showing a three-dimensional network structure, and channel-like structures were inside the biofilm. Live bacteria were distributed on the surface of the EPS or embedded in them, dead bacteria aggregated between live flora and the bottom layer of biofilms. After being treated with bovine trypsin, the three-dimensional network structure and the channel-like structure disappeared, and the EPS and live and dead bacteria decreased. Quantitative analysis results are as follows. When biofilm was treated for 30 s, 1 min, and 3 min, the minimum effective concentrations of bovine trypsin to reduce EPS were 2 mg/ml ( < 0.05), 0.5 mg/ml ( < 0.05), and 0.25 mg/ml ( < 0.05), respectively. The minimum effective concentrations of bovine trypsin to reduce the live or dead bacteria were 2 mg/ml ( < 0.05), 0.5 mg/ml ( < 0.05), and 0.5 mg/ml ( < 0.05), respectively. There was no significant difference in the ratio of live/dead bacteria after the biofilm was treated for 30 s with bovine trypsin at the concentration of 0.25, 0.5, 1, and 2 mg/ml ( > 0.05), and the minimum effective concentration to reduce the ratio of live bacteria/dead bacteria was 0.25 mg/ml ( < 0.05) after treatment for 1 min and 3 min. Therefore, bovine trypsin can destroy biofilm structure, disperse biofilm and bacteria flora, and reduce the EPS and bacterial biomass, which are positively correlated with the application time and concentration.
PubMed: 35992661
DOI: 10.3389/fmicb.2022.951291