Study on the Antimicrobial Effect of the Extracts of Clerodendron bungei Roots

[ Objective ] The aim was to research the antimicrobial effect of the extracts of Clerodendron bungei roots with different solvents on the common plant microbes. [ Method] The bacteria cake method was used to study the antimicrobial capability of Clerodendron bungei roots. [ Result ] The extracts have anti-bacterial action on Rhixoctonia cerealis V. Hoeven, Fusarium graminearum, Rhizoctonia solani and Setosphaeria turcica, especially the extract from distilled water has the strongest anti-bacterial action on Rhixoctonia cerealis V. Hoeven and Fusarium graminearum, the extract from ether has the strongest anti-bacterial action on Fusarium graminearum, the MIC all were 10 mg/ml. The extracts had different antimicrobial effect when pH value was from 5 to 8[ Conclusion] The extracts of Clerodendron bungei roots could inhibit the 4 pathogenic microorganism, and the antibacterial activity was affected by pH value greatly.

Preparation, characterization, antimicrobial and cytotoxicity studies of copper/zincloaded montmorillonite

Background： A series of modified montmorillonites（Mt） including zinc-loaded Mt（Zn-Mt）, copper-loaded Mt（Cu-Mt）, copper/zinc-loaded Mt with different Cu/Zn ratio（Cu/Zn-Mt-1, Cu/Zn-Mt-2, Cu/Zn-Mt-3） were prepared by an ion-exchange reaction, and characterized using X-ray diffraction（XRD）, fourier transformed infrared spectroscopy（FTIR） and transmission electron microscopy（TEM）. The specific surface areas, antimicrobial activity and cytotoxicity of the modified Mt were investigated.Results： In the modified Mt, hydrated Cu ions and Zn ions were exchanged in the interlayer space of Mt and the particles were irregular shapes. The results showed that Cu/Zn-Mt enhanced antibacterial and antifungal activity compared with Zn-Mt and Cu-Mt possibly due to the synergistic effect between Cu and Zn. Among the Cu/Zn-Mt with different Cu/Zn raitos, Cu/Zn-Mt with a Cu/Zn ratio of 0.98 or 0.51 showed higher antimicrobial activity against gram-negative bacteria（Escherichia coli）, gram-positive bacteria（Staphylococcus aureus）, fungi（Candida albicans）.Moreover, the antimicrobial activity of Cu/Zn-Mt was correlated with its specific surface area. Cytotoxicity studies on IPEC-J2 cell showed a slight cytotoxicity of Cu/Zn-Mt.Conclusions： The current data provide clear evidence that in terms of its antimicrobial activity and relatively low toxicity, the Cu/Zn-Mt holds great promise for applications in animal husbandry.

Copper as an alternative antimicrobial coating for implants-An in vitro study

AIM To investigate osteoconductive and antimicrobial properties of a titanium-copper-nitride(TiC uN) film and an additional BONIT~? coating on titanium substrates.METHODS For micro-structuring, the surface of titanium test samples was modified by titanium plasma spray(TPS). On the TPS-coated samples, the Ti Cu N layer was deposited by physical vapor deposition. The BONIT~? layer was coated electrochemically. The concentration of copper ions released from TiC uN films was measured by atomic absorption spectrometry. MG-63 osteoblasts on Ti Cu N and BONIT~? were analyzed for cell adhesion, viability and spreading. In parallel, Staphylococcus epidermidis(S. epidermidis) were cultivated on the samples and planktonic and biofilm-bound bacteria were quantified bycounting of the colony-forming units. RESULTS Field emission scanning electron microscopy(FESEM) revealed rough surfaces for TPS and TiC uN and a special crystalline surface structure on TiC uN + BONIT~?. TiC uN released high amounts of copper quickly within 24 h. These release dynamics were accompanied by complete growth inhibition of bacteria and after 2 d, no planktonic or adherent S. epidermidis were found on these samples. On the other hand viability of MG-63 cells was impaired during direct cultivation on the samples within 24 h. However, high cell colonization could be found after a 24 h pre-incubation step in cell culture medium simulating the in vivo dynamics closer. On pre-incubated TiC uN, the osteoblasts span the ridges and demonstrate a flattened, well-spread phenotype. The additional BONIT~?-coating reduced the copper release of the TiC uN layer significantly and showed a positive effect on the initial cell adhesion.CONCLUSION The Ti Cu N-coating inhibits the formation of bacterial biofilms on orthopedic implants by influencing the "race for the surface" to the advantage of osteoblasts.

Synthesis and Characterization of Green Potassium Nanoparticles from Sideroxylon Capiri and Evaluation of Their Potential Antimicrobial

In the present study,the green synthesis of potassium nanoparticles(K-NPs)was assessed using aqueous extract of Sideroxylon capiri.The potassium nanoparticles were analyzed by UV-visible spectroscopic techniques,X-ray spectrometers of energy dispersive(SEM-EDS)and dynamic light scattering.The results showed high values at 3.5 keV confirming the formation of potassium nanoparticles and the SEM analysis showed an agglomerated particles size between 360 to 200 nm with a spherical morphology.The K-NPs showed an effective antibacterial activity against the test organisms mainly with Bacillus cereus,Enterobacter aerogenes,Fusarium solani and Botrytis cinerea.However further studies about nanotoxicity of K-NPs are needed to confirm their potential in the control of the pathogen microorganisms under field conditions.

Antimicrobial Effect of Silver Ionised Water Prepared with the Sintering Coating Method—Effect on Acid Production in Plaque

Purpose: To investigate the effect of silver ionised water on acid production in plaque. Methods: After injecting 0.5 mL of silver ionised water (concentration: 5 ppm) produced with the sintering coating method in the sensor part of the pH metre, plaque collected from the oral cavity by one platinum loop was mixed in. Immediately after that, a 5% sucrose solution (1 g/20 mL) was added and the pH was continuously measured for 30 minutes at 1-minute intervals (A). Similarly, silver ionised water was mixed with 5% sucrose solution in the same way as in (A) at 3 (B), 5 (C), 10 (D) and 15 minutes (E) after plaque contamination. The pH was measured at 1-minute intervals. The pH of the purified water containing no silver ionised water mixed with plaque and sugar solution at the same time was measured and used as a control. Each experiment was conducted three times, and the pH measured every minute was compared as a percentage of the pH at the beginning of the measurement (100%). Results: Analysis of variance of the repeated measurements to determine the effect of silver ionised water on the decrease in pH revealed a main effect of silver ionised water and an interaction between time and group [F(1.302,20.826) = 39.145, p < 0.01]. Multiple comparisons using Dunnett’s method showed a significant decline in the rate of decrease in pH from B to E as compared with that in the control (p < 0.01). Conclusion: Silver ionised water was found to inhibit the acid production in plaque.

Effectiveness of Disinfection of Anesthetics Tubes in Oral Surgery -An in Vitro Study

Context： Anesthetic tubes are always on the surgical table, for this reason, it＇s necessary to perform its disinfection, generally by chemicals. Aim： Was to analyze the effectiveness of tubes decontamination made by disinfectant substances used in a clinical setting and to identify the microorganisms found on their surface. Materials and Methods： 14 anesthetic tubes were collected from dental clinic, on 5 groups. 01 plastic and 01 glass tubes that were not submitted to any disinfection process composed the control group and they had been sown in Agar Blood. Experimental groups underwent immersion and fixation with the proposed chemicals for 1 minute, laminar flow hood was used to seed it in Agar Blood and then it was transferred to incubator for 24 hours at 37℃. Tests were used to identify the main Gram positive pathogenic genera. Gram-negative pathogenic colonies isolated were seeded in biochemical means of identification. Results： It was possible to identify the presence of Staphylococcus coagulase negative, Staphylococcus aureus, Streptococcus viridans, Staphylococcus saprophyticus, Escherichia coli and Acinetobacter spp, as well as the effectiveness of chemical solutions proposed in this study. Conclusions： All chemical solutions proposed in this study were effective for the surface disinfection process of anesthetic tubes.

Antimicrobial and Photocatalytic Effect of Silicate and Silicone Hygienic Coatings

Antimicrobial and photocatalytic effect of silicate and silicone paints were tested. Silicate paints are based on water styrene-acrylic dispersion with mineral binder into form of potassium water glass. Silicone paints are based on water acrylic dispersion with silicone resin emulsion. Silicate and silicone paints were formulated with photocatalytic active nanooxides TiO2 and ZnO. Photocatalytic efficiency of coatings was measured as an absorbance change of organic dye Orange II solution at a wavelength of 485 nm. Antimicrobial properties of coatings were tested using agar plate methods. As test microorganisms Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Penicillium chrysogenum and Aspergillus niger suspension （density 10^6 cells/mL） were used. The inhibition effect of tested coatings and inhibitory zones were evaluated after incubation. Coatings containing nanoparticles of titanium dioxide and zinc oxide showed antimicrobial activity against the test microorganisms. Whereas coating with zinc oxide nanoparticles successfully inhibited the growth of both bacteria and fungi, the photocatalytic nanoparticles of titanium dioxide inhibited bacteria but not fungi （weak inhibition was observed）.

Residual activity of cetrimide and chlorhexidine on Enterococcus faecalis-infected root canals

Effective final irrigation regimen is an important step in order to achieve better disinfection and ensure residual antimicrobial effects after root canal preparation. The aim of this study was to compare the residual antimicrobial activity of 0.2% cetrimide, and 0.2% and 2% chlorhexidine in root canals infected with Enterococcus faecalis. Biofilms of E. faecalis were grown on uniradicular roots for 4 weeks. After root canal preparation, root canals were irrigated with 17% ethylenediaminetetraacetic acid （EDTA） to remove the smear layer. The roots were randomly divided into three experimental groups （n=26） according to the final irrigating solution： Group I, 5 mL 0.2% cetrimide; Group II, 5 mL 0.2% chlorhexidine; and Group III, 5 mL 2% chlorhexidine. Samples were collected for 50 days to denote the presence of bacterial growth. The proportion of ungrown specimens over 50 days was evaluated using the nonparametric Kaplan-Meier survival analysis. Differences among groups were tested using the log-rank test and the level of statistical significance was set at P〈0.05. The highest survival value was found with 2% chlorhexidine, showing statistically significant differences from the other two groups. At 50 days, E. faecalisgrowth was detected in 69.23% specimens in Groups I and II, and in 34.61% specimens of Group III. There were no significant differences between 0.2% cetrimide and 0.2% chlorhexidine. Final irrigation with 2% chlorhexidine showed greater residual activity than 0.2% chlorhexidine and 0.2% cetrimide in root canals infected with E. faecalis.

Review of the potential of mesenchymal stem cells for the treatment of infectious diseases

The therapeutic value of mesenchymal stem cells (MSCs) for the treatment of infectious diseases and the repair of disease-induced tissue damage has been explored extensively. MSCs inhibit inflammation, reduce pathogen load and tissue damage encountered during infectious diseases through the secretion of antimicrobial factors for pathogen clearance and they phagocytose certain bacteria themselves. MSCs dampen tissue damage during infection by downregulating thelevels of pro-inflammatory cytokines, and inhibiting the excessive recruitment ofneutrophils and proliferation of T cells at the site of injury. MSCs aid in theregeneration of damaged tissue by differentiating into the damaged cell types orby releasing paracrine factors that direct tissue regeneration, differentiation, andwound healing. In this review, we discuss in detail the various mechanisms bywhich MSCs help combat pathogens, tissue damage associated with infectiousdiseases, and challenges in utilizing MSCs for therapy.

A green synthesis of antimicrobial compounds from marine microalgae Nannochloropsis oculata

Objective:To determine the antibacterial and anti-candidal activities of fatty acid methyl esters(FAME)extracted from marine microalga Nannochloropsis oculata and evaluate the inhibition activity of DNA isolated from test pathogenic microorganism.Methods:FAME was synthesized by transesterification of oil using immobilized lipase and characterized using gas chromatography-mass spectrometer.The FAME profile was determined using gas chromatography.The antimicrobial effect was tested by disc diffusion method against Gram-positive bacteria Staphylococcus aureus,Bacillus subtilis,Gram-negative bacteria Escherichia coli,Pseudomonas aeruginosa and yeast Candida albicans,at varying concentrations of 10,20 and 30μL/disc.Results:The results shown that palmitic acid(C16:0),oleic acid(C18:1)and arachidic acid(C20:0)were dominant in Nannochloropsis oculata oil.The study revealed that FAME was more active against Gram-negative than against Gram-positive and yeast.DNA inhibition activity results also confirmed that FAME had the bactericidal effect that was revealed by sheared fragments of DNA.Conclusions:The results indicated that microalgal FAME could be potentially utilized as a newer and good source of therapeutic agent in pharmaceutical industry.