scholarly journals The Impact of CO2 Laser Treatment and Acidulated Phosphate Fluoride on Enamel Demineralization and Biofilm Formation

2019 ◽  
Vol 10 (3) ◽  
pp. 200-206
Author(s):  
Ana Bárbara de Araújo Loiola ◽  
Carolina Patrícia Aires ◽  
Fabiana Almeida Curylofo-Zotti ◽  
Antônio Luiz Rodrigues Junior ◽  
Aline Evangelista Souza-Gabriel ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Co2 Laser ◽  
Biofilm Formation ◽  
Enamel Demineralization ◽  
Demineralized Enamel ◽  
Continuous Co2 Laser ◽  
Co2 Laser Treatment ◽  
The Impact

Introduction: This study evaluated the impact of CO2 laser treatment and acidulated phosphate fluoride (APF) on enamel demineralization and biofilm formation, using in vitro and in situ designs. Methods: Demineralized enamel slabs were distributed among 8 groups: placebo, placebo + continuous CO2 laser, placebo + repeated CO2 laser, placebo + ultrapulsed CO2 laser, 1.23% APF, APF + continuous CO2 laser, APF + repeated CO2 laser and APF + ultrapulsed CO2 laser. In the in vitro study, 15 enamel slabs from each group were subjected to a pH-cycling regimen for 14 days. In the cross over in situ design, 11 volunteers wore palatal appliances with demineralized enamel slabs for 2 periods of 14 days each. Drops of sucrose solution were dripped onto enamel slabs 8×/day. Biofilms formed on slabs were collected and the colony-forming units (CFU) of Streptococcus mutans and Lactobacillus were determined. Results: For both in vitro and in situ studies, there was no significant difference between treatments (P>0.05). However, all treatments increased microhardness of demineralized enamel (P<0.05). After a further in situ cariogenic challenge, with the exception of the placebo, all treatments maintained microhardness values (P<0.05). Microbiological analysis showed no difference in Streptococcus mutans (P>0.05) or Lactobacillus (P>0.05) counts between groups. Conclusion: The results suggest that APF gel combined with the CO2 laser, regardless of the pulse emission mode used, was effective in controlling enamel demineralization, but none of the tested treatments was able to prevent bacterial colonization.

Does Finishing and Polishing of Restorative Materials Affect Bacterial Adhesion and Biofilm Formation? A Systematic Review

2018 ◽  
Vol 43 (1) ◽  
pp. E37-E52 ◽  
Author(s):  
DAM Dutra ◽  
GKR Pereira ◽  
KZ Kantorski ◽  
LF Valandro ◽  
FB Zanatta
Keyword(s):  
Systematic Review ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Surface Characteristics ◽  
Periodontal Inflammation ◽  
Restorative Materials ◽  
The Impact

SUMMARY Biofilm (bacterial plaque) accumulation on the surface of restorative materials favors the occurrence of secondary caries and periodontal inflammation. Surface characteristics of restorations can be modified by finishing and/or polishing procedures and may affect bacterial adhesion. The aim of this systematic review was to characterize how finishing and polishing methods affect the surface properties of different restorative materials with regard to bacterial adhesion and biofilm formation. Searches were carried out in MEDLINE-PubMed, EMBASE, Cochrane-CENTRAL, and LILACS databases. From 2882 potential articles found in the initial searches, only 18 met the eligible criteria and were included in this review (12 with in vitro design, four with in situ design, and two clinical trials). However, they presented high heterogeneity regarding materials considered and methodology for evaluating the desired outcome. Risk bias analysis showed that only two studies presented low risk (whereas 11 showed high and five showed medium risk). Thus, only descriptive analyses considering study design, materials, intervention (finishing/polishing), surface characteristics (roughness and surface free energy), and protocol for biofilm formation (bacterial adhesion) could be performed. Some conclusions could be drawn: the impact of roughness on bacterial adhesion seems to be related not to a roughness threshold (as previously believed) but rather to a range, the range of surface roughness among different polishing methods is wide and material dependent, finishing invariably creates a rougher surface and should always be followed by a polishing method, each dental material requires its own treatment modality to obtain and maintain as smooth a surface as possible, and in vitro designs do not seem to be powerful tools to draw relevant conclusions, so in vivo and in situ designs become strongly recommended.

The Intra-oral Effect on Enamel Demineralization of Extracellular Matrix Material Synthesized from Sucrose by Streptococcus mutans

1986 ◽  
Vol 65 (6) ◽  
pp. 918-923 ◽  
Author(s):  
D.T. Zero ◽  
J. van Houte ◽  
J. Russo
Keyword(s):  
Extracellular Matrix ◽  
Streptococcus Mutans ◽  
Cell Density ◽  
Matrix Material ◽  
Enamel Demineralization ◽  
Oral Test ◽  
Ph Stat

The role of extracellular matrix material (EMM) synthesized from sucrose (S) by Streptococcus mutans IB-1600 in altering the demineralizing potential of artificial plaque was evaluated with an intra-oral enamel demineralization test (IEDT). The artificial plaque samples were prepared from cells cultivated in Todd-Hewitt broth (THB) supplemented with various S concentrations and by mixing THB-grown cells with increasing proportions of EMM (heat-killed THB + 2% S-cultivated cells). The samples were also evaluated for cell density (DNA content) and acidogenicity in vitro (pH-stat), as well as for in situ pH changes during a 45-minute intra-oral test following a 10% glucose rinse. An increase in the proportion of EMM relative to cell density was associated with an increase in enamel demineralization. This trend reversed when the ratio of cells to EMM was less than 1 :19. Experiments involving strains of S. mitis, S. sanguis, and S. salivarius suggested a similar effect of EMM. The intra-oral pH data suggest that the presence of EMM may enhance demineralization by altering diffusion properties of plaque.

scholarly journals Antibiofilm and antivirulence potential of silver nanoparticles against multidrug-resistant Acinetobacter baumannii

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helal F. Hetta ◽  
Israa M. S. Al-Kadmy ◽  
Saba Saadoon Khazaal ◽  
Suhad Abbas ◽  
Ahmed Suhail ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Infection Model ◽  
The Impact

AbstractWe aimed to isolate Acinetobacter baumannii (A. baumannii) from wound infections, determine their resistance and virulence profile, and assess the impact of Silver nanoparticles (AgNPs) on the bacterial growth, virulence and biofilm-related gene expression. AgNPs were synthesized and characterized using TEM, XRD and FTIR spectroscopy. A. baumannii (n = 200) were isolated and identified. Resistance pattern was determined and virulence genes (afa/draBC, cnf1, cnf2, csgA, cvaC, fimH, fyuA, ibeA, iutA, kpsMT II, PAI, papC, PapG II, III, sfa/focDE and traT) were screened using PCR. Biofilm formation was evaluated using Microtiter plate method. Then, the antimicrobial activity of AgNPs was evaluated by the well-diffusion method, growth kinetics and MIC determination. Inhibition of biofilm formation and the ability to disperse biofilms in exposure to AgNPs were evaluated. The effect of AgNPs on the expression of virulence and biofilm-related genes (bap, OmpA, abaI, csuA/B, A1S_2091, A1S_1510, A1S_0690, A1S_0114) were estimated using QRT-PCR. In vitro infection model for analyzing the antibacterial activity of AgNPs was done using a co-culture infection model of A. baumannii with human fibroblast skin cell line HFF-1 or Vero cell lines. A. baumannii had high level of resistance to antibiotics. Most of the isolates harbored the fimH, afa/draBC, cnf1, csgA and cnf2, and the majority of A. baumannii produced strong biofilms. AgNPs inhibited the growth of A. baumannii efficiently with MIC ranging from 4 to 25 µg/ml. A. baumannii showed a reduced growth rate in the presence of AgNPs. The inhibitory activity and the anti-biofilm activity of AgNPs were more pronounced against the weak biofilm producers. Moreover, AgNPs decreased the expression of kpsMII , afa/draBC,bap, OmpA, and csuA/B genes. The in vitro infection model revealed a significant antibacterial activity of AgNPs against extracellular and intracellular A. baumannii. AgNPs highly interrupted bacterial multiplication and biofilm formation. AgNPs downregulated the transcription level of important virulence and biofilm-related genes. Our findings provide an additional step towards understanding the mechanisms by which sliver nanoparticles interfere with the microbial spread and persistence.

scholarly journals Understanding the Basis of METH Mouth Using a Rodent Model of Methamphetamine Injection, Sugar Consumption, and Streptococcus mutans Infection

mBio ◽  
2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Hiu Ham Lee ◽  
Preethi Sudhakara ◽  
Shreena Desai ◽  
Kildare Miranda ◽  
Luis R. Martinez
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Human Saliva ◽  
Tooth Decay ◽  
Content Type ◽  
Oral Rinse ◽  
Tooth Grinding ◽  
Oral Tissue ◽  
Public Health Strategies ◽  
The Impact

ABSTRACT “METH mouth” is a common consequence of chronic methamphetamine (METH) use, resulting in tooth decay and painful oral tissue inflammation that can progress to complete tooth loss. METH reduces the amount of saliva in the mouth, promoting bacterial growth, tooth decay, and oral tissue damage. This oral condition is worsened by METH users’ compulsive behavior, including high rates of consumption of sugary drinks, recurrent tooth grinding, and a lack of frequent oral hygiene. Streptococcus mutans is a Gram-positive bacterium found in the oral cavity and associated with caries in humans. Hence, we developed a murine model of METH administration, sugar intake, and S. mutans infection to mimic METH mouth in humans and to investigate the impact of this drug on tooth colonization. We demonstrated that the combination of METH and sucrose stimulates S. mutans tooth adhesion, growth, and biofilm formation in vivo. METH and sucrose increased the expression of S. mutans glycosyltransferases and lactic acid production. Moreover, METH contributes to the low environmental pH and S. mutans sucrose metabolism, providing a plausible mechanism for bacterium-mediated tooth decay. Daily oral rinse treatment with chlorhexidine significantly reduces tooth colonization in METH- and sucrose-treated mice. Furthermore, human saliva inhibits S. mutans colonization and biofilm formation after exposure to either sucrose or the combination of METH and sucrose. These findings suggest that METH might increase the risk of microbial dental disease in users, information that may help in the development of effective public health strategies to deal with this scourge in our society. IMPORTANCE “METH mouth” is characterized by severe tooth decay and gum disease, which often causes teeth to break or fall out. METH users are also prone to colonization by cariogenic bacteria such as Streptococcus mutans. In addition, this oral condition is aggravated by METH users’ compulsive behavior, including the consumption of beverages with high sugar content, recurrent tooth grinding, and a lack of frequent oral hygiene. We investigated the effects of METH and sugar consumption on S. mutans biofilm formation and tooth colonization. Using a murine model of METH administration, sucrose ingestion, and oral infection, we found that the combination of METH and sucrose increases S. mutans adhesion and biofilm formation on the teeth of C57BL/6 mice. However, daily chlorhexidine-based oral rinse treatment reduces S. mutans tooth colonization. Similarly, METH has been associated with dry mouth or hyposalivation in users. Hence, we assessed the impact of human saliva on biofilm formation and demonstrated that surface preconditioning with saliva substantially reduces S. mutans biofilm formation. Our results are significant because to our knowledge, this is the first basic science study focused on elucidating the fundamentals of METH mouth using a rodent model of prolonged drug injection and S. mutans oral infection. Our findings may have important translational implications for the development of treatments for the management of METH mouth and more effective preventive public health strategies that can be applied to provide effective dental care for METH users in prisons, drug treatment centers, and health clinics.

The effect of polyhydroxyalkanoates in Pseudomonas chlororaphis PA23 biofilm formation, stress endurance, and interaction with the protozoan predator Acanthamoeba castellanii

2021 ◽  
pp. 1-15
Author(s):  
Akrm Ghergab ◽  
Nisha Mohanan ◽  
Grace Saliga ◽  
Ann Karen C. Brassinga ◽  
David Levin ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Acanthamoeba Castellanii ◽  
Pseudomonas Chlororaphis ◽  
Enhanced Sensitivity ◽  
Hostile Environments ◽  
The Impact ◽  
Environmental Fitness ◽  
Root Attachment

Pseudomonas chlororaphis PA23 is a biocontrol agent capable of protecting canola against the fungal pathogen Sclerotinia sclerotiorum. In addition to producing antifungal compounds, this bacterium synthesizes and accumulates polyhydroxyalkanoate (PHA) polymers as carbon and energy storage compounds. Because the role of PHA in PA23 physiology is currently unknown, we investigated the impact of this polymer on stress resistance, adherence to surfaces, and interaction with the protozoan predator Acanthamoeba castellanii. Three PHA biosynthesis mutants were created, PA23phaC1, PA23phaC1ZC2, and PA23phaC1ZC2D, which accumulated reduced PHA. Our phenotypic assays revealed that PA23phaC1ZC2D produced less phenazine (PHZ) compared with the wild type (WT) and the phaC1 and phaC1ZC2 mutants. All three mutants exhibited enhanced sensitivity to UV irradiation, starvation, heat stress, cold stress, and hydrogen peroxide. Moreover, motility, exopolysaccharide production, biofilm formation, and root attachment were increased in strains with reduced PHA levels. Interaction studies with the amoeba A. castellanii revealed that the WT and the phaC1 and phaC1ZC2 mutants were consumed less than the phaC1ZC2D mutant, likely due to decreased PHZ production by the latter. Collectively these findings indicate that PHA accumulation enhances PA23 resistance to a number of stresses in vitro, which could improve the environmental fitness of this bacterium in hostile environments.

scholarly journals Impact of Bacterial Biofilm Formation on In Vitro and In Vivo Activities of Antibiotics

1998 ◽  
Vol 42 (4) ◽  
pp. 895-898 ◽  
Author(s):  
Silvia Schwank ◽  
Zarko Rajacic ◽  
Werner Zimmerli ◽  
Jürg Blaser
Keyword(s):  
Animal Model ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Phenotypic Resistance ◽  
Vitro Model ◽  
The Impact ◽  
Isogenic Strains

ABSTRACT The impact of bacterial adherence on antibiotic activity was analyzed with two isogenic strains of Staphylococcus epidermidis that differ in the features of their in vitro biofilm formation. The eradication of bacteria adhering to glass beads by amikacin, levofloxacin, rifampin, or teicoplanin was studied in an animal model and in a pharmacokinetically matched in vitro model. The features of S. epidermidis RP62A that allowed it to grow on surfaces in multiple layers promoted phenotypic resistance to antibiotic treatment, whereas strain M7 failed to accumulate, despite initial adherence on surfaces and growth in suspension similar to those for RP62A. Biofilms of S. epidermidis M7 were better eradicated than those of strain RP62A in vitro (46 versus 31%;P < 0.05) as well as in the animal model (39 versus 9%; P < 0.01).

Materials Sealing Preventing Biofilm Formation in Implant/Abutment Joints: Which Is the Most Effective? A Systematic Review and Meta-Analysis

2020 ◽  
Vol 46 (2) ◽  
pp. 163-171
Author(s):  
Cecília Alves de Sousa ◽  
Maria Beatriz Bello Taborda ◽  
Gustavo Antônio Correa Momesso ◽  
Eduardo Passos Rocha ◽  
Paulo Henrique dos Santos ◽  
...  
Keyword(s):  
Systematic Review ◽  
Biofilm Formation ◽  
Meta Analysis ◽  
Significance Level ◽  
Gutta Percha ◽  
Significant Difference ◽  
Physical Barriers ◽  
External Connection

The purpose of this systematic review was to evaluate the literature available for materials exhibiting the best efficacy in preventing biofilm formation in the interior of implants. We searched PubMed/MEDLINE, Scopus, and Cochrane databases. This review is registered with the PROSPERO database and followed the suitability of the PRISMA protocol. The initial search resulted in 326 articles from the databases. After they were read, 8 articles remained, and the inclusion and exclusion criteria were applied. Six of these 8 articles were classified as in vitro and 2 were classified as in situ. The regions of the implants evaluated ranged from the interface of the pieces to the occlusal upper access of the abutment. The implant connections evaluated the Morse taper, external connection, and internal connection. Meta-analysis of the quantitative data was performed at a significance level of .05. Cotton exhibited poor control of infiltration, even in combination with other materials. Isolated gutta-percha (GP) and polytetrafluoroethylene (PTFE) tape with composite resin (CR) or GP performed better as physical barriers. The best results for chemical barriers were observed by the application of 1% chlorhexidine gluconate (CG) gel, thymol varnish, and the deposition of Ag films onto the surface. The applied meta-analysis did not show a significant difference in comparison between the different types of implant connections (P &gt; .05). The application of CG and thymol varnish antimicrobials was effective in preventing biofilm formation and easy clinical execution; these could be used in combination with CR, GP, and PTFE.

scholarly journals O-Vanillin Attenuates the TLR2 Mediated Tumor-Promoting Phenotype of Microglia

2020 ◽  
Vol 21 (8) ◽  
pp. 2959
Author(s):  
Paul Triller ◽  
Julia Bachorz ◽  
Michael Synowitz ◽  
Helmut Kettenmann ◽  
Darko Markovic
Keyword(s):  
Malignant Gliomas ◽  
Experimental Models ◽  
Brain Macrophages ◽  
Human Microglia ◽  
Glioma Growth ◽  
Toll Like Receptor 2 ◽  
Brain Slice Cultures ◽  
The Impact

Malignant gliomas are primary brain tumors with poor prognoses. These tumors are infiltrated by brain intrinsic microglia and peripheral monocytes which promote glioma cell invasion. In our previous studies, we discovered that the activation of Toll-like receptor 2 (TLR2) on microglia/brain macrophages converts them into a protumorigenic phenotype through the induction of matrix metalloproteinases (MMP) 9 and 14. In the present study, we used in vitro and in situ microglia-glioma interaction experimental models to test the impact of a novel inhibitor of TLR 2, ortho vanillin (O-Vanillin) to block TLR2 mediated microglia protumorigenic phenotype. We demonstrate that O-Vanillin inhibits the TLR2 mediated upregulation of MMP 9, MMP 14, IL 6 and iNOS expression. Similarly, the glioma supernatant induced MMP 9 and MMP 14 expression in murine and human microglia is abrogated by O-Vanillin treatment. O-Vanillin is not toxic for microglia, astrocytes or oligodendrocytes. Glioma growth in murine brain slice cultures is significantly reduced after treatment with O-Vanillin, and this reduced glioma growth depends on the presence of microglia. In addition, we also found that O-Vanillin inhibited the glioma induced proliferation of murine primary microglia. In summary, O-Vanillin attenuates the pro-tumorigenic phenotype of microglia/brain macrophages and thus qualifies as a candidate for glioma therapy.

scholarly journals Doxorubicin-Induced Translocation of mtDNA into the Nuclear Genome of Human Lymphocytes Detected Using a Molecular-Cytogenetic Approach

2020 ◽  
Vol 21 (20) ◽  
pp. 7690
Author(s):  
Tigran Harutyunyan ◽  
Ahmed Al-Rikabi ◽  
Anzhela Sargsyan ◽  
Galina Hovhannisyan ◽  
Rouben Aroutiounian ◽  
...  
Keyword(s):  
Human Lymphocytes ◽  
Nuclear Genome ◽  
Biological Phenomenon ◽  
Molecular Cytogenetic ◽  
Chromosome Breaks ◽  
Pathological Conditions ◽  
The Impact ◽  
In Vitro Treatment

Translocation of mtDNA in the nuclear genome is an ongoing process that contributes to the development of pathological conditions in humans. However, the causal factors of this biological phenomenon in human cells are poorly studied. Here we analyzed mtDNA insertions in the nuclear genome of human lymphocytes after in vitro treatment with doxorubicin (DOX) using a fluorescence in situ hybridization (FISH) technique. The number of mtDNA insertions positively correlated with the number of DOX-induced micronuclei, suggesting that DOX-induced chromosome breaks contribute to insertion events. Analysis of the odds ratios (OR) revealed that DOX at concentrations of 0.025 and 0.035 µg/mL significantly increases the rate of mtDNA insertions (OR: 3.53 (95% CI: 1.42–8.76, p < 0.05) and 3.02 (95% CI: 1.19–7.62, p < 0.05), respectively). Analysis of the distribution of mtDNA insertions in the genome revealed that DOX-induced mtDNA insertions are more frequent in larger chromosomes, which are more prone to the damaging action of DOX. Overall, our data suggest that DOX-induced chromosome damage can be a causal factor for insertions of mtDNA in the nuclear genome of human lymphocytes. It can be assumed that the impact of a large number of external and internal mutagenic factors contributes significantly to the origin and amount of mtDNA in nuclear genomes.

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