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Microorganisms Nov 2021Oral probiotics are beneficial bacteria that can help prevent periodontal disease. However, little is known about the effects of oral probiotics on the formation of...
Oral probiotics are beneficial bacteria that can help prevent periodontal disease. However, little is known about the effects of oral probiotics on the formation of implant biofilms. This study aimed to evaluate the effects of oral probiotics CMU and CMS1 in an in vitro complex biofilm model on titanium implant surfaces. First, it was identified through colony biofilm assay that CMU and CMS1 inhibit the formation of multi-species biofilms formed by eight types of bacteria. Two types of saliva-coated titanium discs inoculated with early ( and ), secondary ( and ), and late () colonizers were treated with the oral probiotics and then incubated anaerobically for three days. The effects of oral probiotics on titanium disc biofilm formation were analyzed using culture methods, quantitative polymerase chain reaction (qPCR), and microscopic analysis. Both probiotics significantly inhibited the formation of biofilm, and all eight bacterial species were significantly reduced. The effectiveness of both probiotic strains was confirmed by all the methods used. Oral probiotics may have dramatically reduced the biofilm formation of secondary colonizers that act as bridges, thus inhibiting biofilm formation on the titanium surface. Our results suggest that the probiotic offers new possibilities for the prevention of peri-implant mucositis.
PubMed: 34946084
DOI: 10.3390/microorganisms9122482 -
BMC Oral Health Dec 2021The oral microbiota is a significant risk indicator for oral diseases, such as dental caries and periodontal inflammation. Much attention is presently paid to the...
BACKGROUND
The oral microbiota is a significant risk indicator for oral diseases, such as dental caries and periodontal inflammation. Much attention is presently paid to the development of functional foods (e.g. beverages containing cranberry constituents, or foods containing probiotics) that may serve as adjuncts for oral disease treatments (e.g. periodontitis and caries). Cranberry fruit, due to its unique chemical composition and antimicrobial potential, is a possible ingredient of such foods. The study aimed to investigate the effects of cranberry juice (CJ) and a cranberry functional beverage (mixture of 80% v/v apple juice, 20% v/v cranberry juice, and 0.25 g/100 mL ground cinnamon; CFB) on the growth and metabolic activity of selected oral bacteria.
METHODS
Serial dilution pour plate method (SDPP) was used to examine the effect of CJ and CFB on the growth of Actinomyces naeslundii, Streptococcus mutans, and Lactobacillus paracasei subsp. paracasei. 48-h electrical impedance measurements (EIM) during the cultivation of A. naeslundii were applied to evaluate the utility of the method as a rapid alternative for the assessment of the antimicrobial potential of cranberry beverages.
RESULTS
The tested bacteria differed in their susceptibility to the antimicrobial action of CJ and CFB, with L. paracasei subsp. paracasei being least vulnerable to CFB (according to SDPP). Although CJ at a concentration of 0.5 mL/mL, showed a bactericidal effect on the growth of S. mutans, A. naeslundii was more sensitive to CJ (SDPP). Its inhibitory effect on A. naeslundii was seen even at concentrations as small as 0.03125-0.125 mL/mL (SDPP and EIM). On the other hand, S. mutans seemed to be more vulnerable to CFB than A. naeslundii (SDPP).
CONCLUSIONS
CFB may be considered an adjunct in the treatment of oral diseases due to its action against selected oral pathogens, and not against the presumably beneficial L. paracasei subsp. paracasei. Bioelectrical impedance measurements appear to be a quick alternative to evaluating the antimicrobial activity of fruit beverages, but their utility should be confirmed with tests on other bacteria.
Topics: Beverages; Dental Caries; Fruit; Humans; Microbiota; Streptococcus mutans; Vaccinium macrocarpon
PubMed: 34930215
DOI: 10.1186/s12903-021-02025-w -
Frontiers in Cellular and Infection... 2021Secondary caries caused by oral microbiome dysbiosis and hybrid layer degradation are two important contributors to the poor resin-dentin bond durability. Cavity...
OBJECTIVE
Secondary caries caused by oral microbiome dysbiosis and hybrid layer degradation are two important contributors to the poor resin-dentin bond durability. Cavity cleansers with long-term antimicrobial and anti-proteolytic activities are in demand for eliminating bacteria-induced secondary caries and preventing hybrid layers from degradation. The objectives of the present study were to examine the long-term antimicrobial effect and anti-proteolytic potential of poly(amidoamine) dendrimers with amino terminal groups (PAMAM-NH) cavity cleanser.
METHODS
Adsorption tests by attenuated total reflectance-infrared (ATR-IR) spectroscopy and confocal laser scanning microscopy (CLSM) were first performed to evaluate whether the PAMAM-NH cavity cleanser had binding capacity to dentin surface to fulfill its relatively long-term antimicrobial and anti-proteolytic effects. For antibacterial testing, , , and were grown on dentin surfaces, prior to the application of cavity cleanser. Colony-forming unit (CFU) counts and live/dead bacterial staining were performed to assess antibacterial effects. Gelatinolytic activity within the hybrid layers was directly detected by zymography. Adhesive permeability of bonded interface and microtensile bond strength were employed to assess whether the PAMAM-NH cavity cleanser adversely affected resin-dentin bonding. Finally, the cytotoxicity of PAMAM-NH was evaluated by the Cell Counting Kit-8 (CCK-8) assay.
RESULTS
Adsorption tests demonstrated that the binding capacity of PAMAM-NH on dentin surface was much stronger than that of 2% chlorhexidine (CHX) because its binding was strong enough to resist phosphate-buffered saline (PBS) washing. Antibacterial testing indicated that PAMAM-NH significantly inhibited bacteria grown on the dentin discs as compared with the control group (p < 0.05), which was comparable with the antibacterial activity of 2% CHX (p > 0.05). Hybrid layers conditioned with PAMAM-NH showed significant decrease in gelatin activity as compared with the control group. Furthermore, PAMAM-NH pretreatment did not adversely affect resin-dentin bonding because it did not decrease adhesive permeability and microtensile strength. CCK-8 assay showed that PAMAM-NH had low cytotoxicity on human dental pulp cells (HDPCs) and L929.
CONCLUSIONS
PAMAM-NH cavity cleanser developed in this study could provide simultaneous long-term antimicrobial and anti-proteolytic activities for eliminating secondary caries that result from a dysbiosis in the oral microbiome and for preventing hybrid layers from degradation due to its good binding capacity to dentin collagen matrix, which are crucial for the maintenance of resin-dentin bond durability.
Topics: Anti-Bacterial Agents; Chlorhexidine; Dentin; Dentin-Bonding Agents; Humans; Streptococcus mutans
PubMed: 34869081
DOI: 10.3389/fcimb.2021.784153 -
Materials (Basel, Switzerland) Oct 2021Peri-implantitis (PI) is a relatively frequent pathology that compromises the overall survival of the dental implant. Adjunctive approaches for the conventional...
Peri-implantitis (PI) is a relatively frequent pathology that compromises the overall survival of the dental implant. Adjunctive approaches for the conventional mechanical debridement are being suggested to optimize the treatment of PI. The goal of the study was the assessment of the disinfection potential of the Q-Switch Nd: YAG laser on contaminated titanium implant surfaces. A total of 72 sterile titanium discs were used and divided into three groups: 24 contaminated titanium discs treated with the laser (study Group L), 24 contaminated titanium discs with no treatment (control 1-Group C), and 24 sterile titanium discs with no treatment (control 2-Group S). Multi-species biofilm was used: Porphyromonas gingivalis, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Streptococcus mutans, Streptococcus sobrinus, and Prevotella intermedia. Commensal bacteria were included also: Actinomyces naeslundii, Actinomyces viscosus, Streptococcus cristatus, Streptococcus gordonii, Streptococcus mitis, Streptococcus oralis, Streptococcus sanguinis, Streptococcus parasanguinis, and Veillonella parvula. Parameters delivered per pulse on the targeted surfaces of the titanium discs were an energy density of 0.597 J/cm each pulse, a pulse power of 270 mW, a laser beam spot of 2.4 mm in diameter, and a rate of repetition of 10 Hertz (Hz) for a pulse duration of 6 nanoseconds (ns). The mode was no contact, and a distance of 500 micrometers was used with a total time of irradiation equal to 2 s (s). The collection of microbiological samples was made for all groups; colony-forming units (CFU) were identified by two different practitioners, and the average of their examinations was considered for each sample. The average of the TBC (CFU/mL) was calculated for each group. Values were 0.000 CFU/mL, 4767 CFU/mL, and 0.000 CFU/mL for Group L, Group C, and Group S, respectively. Therefore, the suggested treatment protocol was able to provoke a total disinfection of the contaminated titanium surfaces. A statistical difference was only found between Group L vs. Group C and between Group S vs. Group C. The difference was not significant between Group S and Group L. In conclusion, the present study confirmed that the Q-Switch Nd: YAG laser under our specific conditions can provide a total disinfection of the contaminated titanium surfaces.
PubMed: 34683666
DOI: 10.3390/ma14206078 -
Microorganisms Oct 2021This study evaluated the microbial colonization (adhesion and biofilm) on modified surfaces of a titanium alloy, Ti-35Nb-7Zr-5Ta, anodized with Ca and P or F ions, with...
This study evaluated the microbial colonization (adhesion and biofilm) on modified surfaces of a titanium alloy, Ti-35Nb-7Zr-5Ta, anodized with Ca and P or F ions, with and without silver deposition. The chemical composition, surface topography, roughness (Ra), and surface free energy were evaluated before and after the surface modifications (anodizing). Adhesion and biofilm formation on saliva-coated discs by primary colonizing species (, , ) and a periodontal pathogen () were assessed. The surfaces of titanium alloys were modified after anodizing with volcano-shaped micropores with Ca and P or nanosized with F, both with further silver deposition. There was an increase in the Ra values after micropores formation; CaP surfaces became more hydrophilic than other surfaces, showing the highest polar component. For adhesion, no difference was detected for on all surfaces, and some differences were observed for the other three species. No differences were found for biofilm formation per species on all surfaces. However, biofilm counts on distinct surfaces were lower than , , and on some surfaces. Therefore, anodized Ti-35Nb-7Zr-5Ta affected microbial adhesion and subsequent biofilm, but silver deposition did not hinder the colonization of these microorganisms.
PubMed: 34683474
DOI: 10.3390/microorganisms9102154 -
Journal of Fungi (Basel, Switzerland) Aug 2021is a phytopathogenic fungus. To know more about the metabolites produced by this fungus, the objective of this work was to identify, isolate and characterize substances...
is a phytopathogenic fungus. To know more about the metabolites produced by this fungus, the objective of this work was to identify, isolate and characterize substances present in extracts of the growth broth and mycelium, using gas chromatography with mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). It was also objective to evaluate the antibacterial activity of the extracts. Among the compounds identified, fatty acids, esters, and steroids can be highlighted. The main compounds identified are 9-hexadecenoic, hexadecenoic, oleic, octadecanoic, lauric, myristic, palmitic, doceno-13-enoic, stearic, linoleic, and nonadecanoic acids present in almost all extracts. For the antibacterial activity, the broth microdilution method was used. The ethyl acetate extract of the mycelium presented inhibitory concentrations (MICs) against the bacterium (100 μg mL) and (200 μg mL). Finally, two steroids were isolated and identified in the hexane extract of mycelium: ergosta-6,22-dien-3β,5α,8α-triol and brassicasterol.
PubMed: 34575718
DOI: 10.3390/jof7090680 -
Journal of Dental Research Mar 2022An intuitive, clinically relevant index of microbial dysbiosis as a summary statistic of subgingival microbiome profiles is needed. Here, we describe a subgingival...
An intuitive, clinically relevant index of microbial dysbiosis as a summary statistic of subgingival microbiome profiles is needed. Here, we describe a subgingival microbial dysbiosis index (SMDI) based on machine learning analysis of published periodontitis/health 16S microbiome data. The raw sequencing data, split into training and test sets, were quality filtered, taxonomically assigned to the species level, and centered log-ratio transformed. The training data set was subject to random forest analysis to identify discriminating species (DS) between periodontitis and health. DS lists, compiled by various "Gini" importance score cutoffs, were used to compute the SMDI for samples in the training and test data sets as the mean centered log-ratio abundance of periodontitis-associated species subtracted by that of health-associated ones. Diagnostic accuracy was assessed with receiver operating characteristic analysis. An SMDI based on 49 DS provided the highest accuracy with areas under the curve of 0.96 and 0.92 in the training and test data sets, respectively, and ranged from -6 (most normobiotic) to 5 (most dysbiotic) with a value around zero discriminating most of the periodontitis and healthy samples. The top periodontitis-associated DS were spp., and , while and were the top health-associated DS. The index was highly reproducible by hypervariable region. Applying the index to additional test data sets in which nitrate had been used to modulate the microbiome demonstrated that nitrate has dysbiosis-lowering properties in vitro and in vivo. Finally, 3 genera (, and ) were identified that could be used for calculation of a simplified SMDI with comparable accuracy. In conclusion, we have developed a nonbiased, reproducible, and easy-to-interpret index that can be used to identify patients/sites at risk of periodontitis, to assess the microbial response to treatment, and, importantly, as a quantitative tool in microbiome modulation studies.
Topics: Dysbiosis; Humans; Microbiota; Periodontitis; RNA, Ribosomal, 16S; Treponema denticola
PubMed: 34428955
DOI: 10.1177/00220345211035775 -
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 -
Antibiotics (Basel, Switzerland) May 2021This study aimed to evaluate the synergistic antimicrobial activity of extracts obtained from (Miswak), (myrrh) and (neem) in combination with commercially available...
BACKGROUND AND OBJECTIVES
This study aimed to evaluate the synergistic antimicrobial activity of extracts obtained from (Miswak), (myrrh) and (neem) in combination with commercially available antimicrobial agents: penicillin, tetracycline, ofloxacin and fluconazole on endodontic pathogens such as and .
MATERIALS AND METHODS
Microbiological samples from the root canals of the teeth undergoing retreatment were taken using sterile paper points kept at full length in the canal for 30 s. The disc diffusion method was used to check the susceptibility of microbes to the plant extracts and antimicrobials by measuring the diameter of the inhibition zones. Against the microbes, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC) of the plant extracts were assessed. The fractional inhibitory concentration index (FICI) was used to estimate the synergistic effect of plant extracts combined with antimicrobials against the resistant endodontic microbes.
RESULTS
The findings clearly indicate the effectiveness of all the three plant extracts, against all the experimental pathogenic microorganisms except for the ineffectiveness of against Maximum antimicrobial activity was displayed by against (MIC = 0.09 ± 1.2 mg/mL, MBC = 0.78 ± 1.25 mg/mL) and the minimum antimicrobial activity was displayed by against (MIC = 12.5 ± 3.25 mg/mL, MBC = 100 ± 3.75 mg/mL). The best synergy was displayed by with fluconazole against (FICI = 0.45).
CONCLUSIONS
The current study delineates the variable antimicrobial activity of plant extracts against the experimental endodontic pathogenic microorganisms. Plant extracts in conjunction with various antimicrobials can be valuable aids in combating relatively resistant endodontic microorganisms that have been the cause of worry in recent years, leading to failure even in treatment procedures following all required protocols.
PubMed: 34065139
DOI: 10.3390/antibiotics10050552 -
Microorganisms Apr 2021Caries preventive varnishes containing only fluoride might differ from those containing a combination of fluoride and antimicrobial components in terms of mineralization...
Caries preventive varnishes containing only fluoride might differ from those containing a combination of fluoride and antimicrobial components in terms of mineralization properties and their impact on the cariogenic biofilm. We compared a fluoride and a fluoride + chlorhexidine (CHX)/cetylpyridinium chloride (CPC) varnish on root caries formation in vitro. One hundred bovine root dentin samples were allocated to five groups ( = 20/group): (1) 7700 ppm fluoride varnish (Fluorprotector S (F)), (2) experimental placebo varnish for F (F-P), (3) 1400 ppm fluoride + 0.3% CHX/0.5% CPC varnish (Cervitec F (CF)), (4) experimental placebo varnish for CF (CF-P), (5) untreated control. Cariogenic challenge was provided using a multi-station, continuous-culture 3-species ( (SM), (LR), (AN)) biofilm model for 10 days. Mineral loss (ΔZ) was evaluated using transversal microradiography and bacterial counts in the biofilm assessed as colony-forming units. Fluorescence in situ hybridization (FISH) and confocal microscopy were performed to assess the three-dimensional biofilm architecture. Mean ± SD (vol% × μm) ΔZ was significantly lower for F (9133 ± 758) and CF (9835 ± 1677) compared to control (11362 ± 919) ( < 0.05), without significant differences between F and CF. SM counts were significantly lower and LR counts significantly higher in F- and CF-biofilms compared to control. AN counts were significantly higher in the F-biofilms than in all other groups. According to FISH, SM and LR invaded dentinal tubules only in the control-group. In the CF-group, the basal biofilm layer did not contain SM and AN. Both F and CF varnishes had similar caries-preventive effects and a considerable impact on biofilm structure and composition.
PubMed: 33916105
DOI: 10.3390/microorganisms9040737