The efficacy of henna (Lawsonia inermis L.) mouthwash versus chlorhexidine gluconate 0.2% mouthwash as adjuvant therapy of oral lichen planus: A randomized double-blind clinical trial.

ETHNOPHARMACOLOGICAL RELEVANCE: In modern medicine, some traditional remedies are introduced to be effective in treatment. Accordingly, the henna plant (Lawsonia inermis L.) is studied more than before. Previous studies have shown many medical properties for henna, such as anti-inflammatory and anti-fungal properties. AIM OF THE STUDY: Oral lichen planus (OLP) is a common mucocutaneous disease with chronic immunomodulatory disruptions. Topical corticosteroids are the first line of OLP treatment. Previous studies have suggested different adjunctive therapies for preventing the side effects of corticosteroids overuse. This study aimed to compare the effects of henna and chlorhexidine mouthwashes as adjunctive therapy. MATERIALS AND METHODS: This parallel-group, double-blind, randomized controlled study was conducted on forty OLP patients. Luteolin content was determined in Henna mouthwash composed of 2% aqueous extract of henna, 2% ethanol, 10% glycerol, and 0.1% methylparaben distilled water. Henna or chlorhexidine mouthwashes were prescribed twice daily as an adjuvant to the topical corticosteroid treatment. Visual analog scale (VAS) index and Thongprasom rating were used to measure pain intensity and clinical signs of patients at days 0,7, and 14. The collected data were analyzed using SPSS software (version 26.0; SPSS). Ordinal logistic regression was used to investigate the effect of independent variables on Thongprasom and VAS scores. RESULTS: In this clinical trial, 82.6% of the participants were women. There was no difference between the two study groups in terms of VAS scores (p = 0.404) and clinical features (p = 0.305) in the second follow-up visit. All drug regimens caused clinical signs and symptoms relief. CONCLUSIONS: There was no significant difference between the groups receiving topical corticosteroid supplementation, neither henna mouthwash nor chlorhexidine mouthwash. The therapeutic effects of henna mouthwash in the main or adjuvant treatment of OLP need more evaluation in future research. Henna mouthwash can be a good alternative to chlorhexidine mouthwash if no side effects are reported.

Development of Chlorhexidine Digluconate and Lippia sidoides Essential Oil Loaded in Microemulsion for Disinfection of Dental Root Canals: Substantivity Profile and Antimicrobial Activity.

The dental intracanal disinfection is crucial to achieve the success of endodontic treatment, avoiding the maintenance of endodontic infections. Chlorhexidine digluconate can act as an irrigating agent for it. However, it can cause tissue irritation in high concentrations. Therefore, combinations with other antimicrobial agents and more efficient therapeutic alternatives are studied, which make it possible to administer drugs more safely and with minimal adverse effects. Thus, the objective of this study was the development of a microemulsion containing chlorhexidine digluconate and essential oil of Lippia sidoides to be used for disinfection of dental root canals and to evaluate its profile of substantivity and antimicrobial activity. The microemulsions were obtained through phase diagrams, using the spontaneous formation method. We completed a physical-chemical characterization and evaluate the stability of the microemulsions, in addition to the substantivity profile in a bovine root dentin model, and in vitro antibacterial effect on Enterococcus faecalis. A method for quantifying chlorhexidine was developed using UV-Vis spectroscopy. The microemulsions showed acid pH, conductivity above 1.3 µScm-1, and dispersion index similar to water. The microemulsions showed antimicrobial inhibition halos similar to the commercial gel conventionally used, but with four times more substantivity to dentinal tissues. Microemulsions were obtained as a therapeutic alternative to formulations available on the market, presenting themselves as a system with great potential for the administration of drugs for disinfection of root canals.

Inhibitory effect of a mouth rinse formulated with chlorhexidine gluconate, ethanol, and green tea extract against major oral bacterial species.

Mouth rinses are a useful supplementary tool for the prevention of oral infectious diseases. Although the antimicrobial effects of mouth rinses have been investigated, there are few studies focusing on the comparison of the effects among various oral bacterial species. In the present study, the inhibitory effect of a commercial mouth rinse, "ConCoolF," and each of its major components, chlorhexidine gluconate, ethanol, and green tea extract, on multiple species of oral bacteria were investigated. Inhibition of bacterial growth was observed in all cariogenic streptococcal species with different genera, serotypes, and strains isolated from different countries when either the complete mouth rinse or chlorhexidine gluconate were used. However, no growth inhibition was observed when the bacteria were exposed to ethanol or green tea extract. Interestingly, growth inhibition was greatly reduced in non-cariogenic streptococci compared with cariogenic streptococci. In addition, both the mouth rinse and chlorhexidine gluconate inhibited the biofilms formed by both Streptococcus mutans (S. mutans) and Porphyromonas gingivalis (P. gingivalis), among which the inhibitory effect against S. mutans was higher than that against P. gingivalis. These results suggest that a mouth rinse containing chlorhexidine gluconate, ethanol, and green tea extract, or chlorhexidine gluconate alone, exhibits antimicrobial activity against several oral bacteria species, having greater activity against pathogenic bacteria.

Synergistic Antibacterial Efficacies of Chlorhexidine Digluconate or Protamine Sulfate Combined with Laminaria japonica or Rosmarinus officinalis Extracts against Streptococcus mutans.

Chlorhexidine digluconate inhibits oral bacteria and the formation of dental plaque. Protamine sulfate, a polycationic protein, exerts antibacterial activity by altering the cell wall of bacteria. Extracts of Laminaria japonica and Rosmarinus officinalis display antimicrobial effects against oral pathogens. The purpose of this study was to investigate the synergistic effect of chlorhexidine digluconate and protamine sulfate on the inhibitory activity of L. japonica and R. officinalis extracts against Streptococcus mutans, a major etiological agent for dental caries. Minimal inhibitory concentrations (MICs) of chlorhexidine digluconate, protamine sulfate, and L. japonica and R. officinalis extracts were determined by broth dilution method. Synergistic effect of chlorhexidine digluconate or protamine sulfate and extracts of L. japonica or R. officinalis was determined by fractional inhibitory concentration index (FIC). FIC demonstrated the synergistic effects of the different combinations of antibacterial agents. In this study, the use of sub-MIC of chlorhexidine digluconate or protamine sulfate with sub-MIC of L. japonica and R. officinalis extracts resulted in synergistic inhibitory effects of these antibacterial agents except for chlorhexidine digluconate and L. japonica combination.

Proton Nuclear Magnetic Resonance Spectroscopy Analysis of Mixtures of Chlorhexidine with Different Oxidizing Agents Activated by Photon-Induced Photoacoustic Streaming for Root Canal Irrigation.

Objective: The aim of this in vitro study was to investigate the possible interactions between photon-induced photoacoustic streaming (PIPS™)-activated oxidizing agents and 2% chlorhexidine digluconate. Background data: There is no information about the safety of laser-activated oxidizing agents in combination usage with chlorhexidine gluconate. Materials and methods: Groups were designed as follows G1: 98% para-chloroaniline (PCA); G2: 2% chlorhexidine (CHX); G3: 5.25% sodium hypochlorite (NaOCl) +2% CHX; G4: 5.25% NaOCl (30 sec PIPS activated) +2% CHX; G5: 5.25% NaOCl (60 sec PIPS activated) +2% CHX; G6: 3.5% chlorine dioxide (ClO2) + 2% CHX; G7: 3.5% (ClO2) (30 sec PIPS activated) +2% CHX; G8: 3.5% (ClO2) (60 sec PIPS activated) +2% CHX. The laser-irrigation protocol was performed with an erbium:yttrium-aluminum-garnet laser with a wavelength of 2940 nm equipped with a 140 mm long endodontic fiber tip (PIPS) using 10 mJ at 15 Hz (0.15 W), per pulse operating outputs. Groups were analyzed with proton nuclear magnetic resonance spectroscopy, using PCA as an internal standard. Results: No free PCA was formed in any groups of mixtures or after PIPS activation. Conclusions: Mixing of 3.5% ClO2 and 2% CHX does not form bulky precipitates, unlike the mixture NaOCl + CHX. PIPS activation does not cause changes in reactions of oxidizing agents.

Lactobacillus plantarum lipoteichoic acid disrupts mature Enterococcus faecalis biofilm.

Apical periodontitis is caused by biofilm-mediated root canal infection. Early phase oral bacterial biofilms are inhibited by Lactobacillus plantarum lipoteichoic acid (Lp.LTA). However, mature biofilms that develop over 3 weeks are more resistant to traditional endodontic medicaments. Therefore, this study examined the effectiveness of Lp.LTA on disrupting mature Enterococcus faecalis biofilms, and on enhancing the effects of endodontic medicaments. LTA was purified from L. plantarum through butanol extraction followed by hydrophobic and ion-exchange chromatography. E. faecalis biofilms were formed over 3 weeks on glass bottom dishes and in dentin blocks obtained from human single-rooted premolars. These mature biofilms were treated with or without Lp.LTA for 1 h, followed by additional treatment with either chlorhexidine digluconate (CHX), calcium hydroxide (CH), or triple antibiotics for 24 h. Biofilms on glass were live/dead stained and quantified by ZEN through confocal laser microscopy. Bio-films in dentin were fixed, sputter coated and analyzed by ImageJ with scanning electron microscopy. Preformed E. faecalis mature biofilms on the culture dishes were dose-dependently disrupted by Lp.LTA. Lp.LTA potentiated the effects of CHX or CH on the disruption of mature biofilm. Interestingly, CHX-induced disruption of preformed E. faecalis mature biofilms was synergistically enhanced only when pre-treated with Lp.LTA. Furthermore, in the dentin block model, Lp.LTA alone reduced E. faecalis mature biofilm and pre-treatment with Lp.LTA promoted the anti-biofilm activity of CHX. Lp.LTA could be an anti-biofilm or supplementary agent that can be effective for E. faecalis-biofilm-induced diseases.

The Contribution of Photodynamic Inactivation vs. Corsodyl Mouthwash to the Control of Streptococcus mutans Biofilms.

This work compared the inhibition effect of the commercially available mouthwash Corsodyl, containing 0.1% chlorhexidine digluconate, and photodynamic inactivation (PDI) employing methylene blue (MB) with irradiation from a red laser on 24-h biofilms formed by Streptococcus mutans strains on hydroxyapatite surfaces. The cytotoxicity of Corsodyl and MB was evaluated by Galleria mellonella surviving assay. The viability of biofilm cells after exposure to mouthwash and PDI was determined by counting colony-forming units. The inhibitory effect of antimicrobial agents was confirmed by confocal scanning laser microscopy. MB did not exhibit a cytotoxic effect on larval survival. Non-diluted Corsodyl slightly decreased the survival of larvae. Using our PDI parameters achieved better inhibition than with non-PDI, proving a significant effect on the eradication of S. mutans biofilms and therefore could be an appropriate supplement for the eradication of dental caries.

Anti-biofilm and anti-inflammatory effect of a herbal nanoparticle mouthwash: a randomized crossover trial.

Laboratory evidence has demonstrated the antimicrobial effect of Melaleuca alternifolia (MEL) against oral microorganisms. This randomized, double-blind, crossover clinical trial, compared the anti-biofilm and anti-inflammatory effects of MEL nanoparticles with 0.12% chlorhexidine gluconate (CHX) on biofilm-free (BF) and biofilm-covered (BC) surfaces. Before each experimental period, the participants refrained from all oral hygiene practices for 72 hours. The 60 participants were randomly assigned to professional prophylaxis in two quadrants (Q1-Q3 or Q2-Q4), and rinsed with MEL or CHX for four days. The Quigley & Hein plaque index (QHPI), gingival crevicular fluid (GCF) volume, and participants' perceptions were assessed. CHX showed significantly lower mean QHPI on BF (2.65 ± 0.34 vs. 3.34 ± 0.33, p < 0.05) and BC surfaces (2.84 ± 0.37 vs. 3.37 ± 0.33, p < 0.05). Intragroup comparisons indicated reductions in GCF in all the groups, with significant differences only for CHX on BF surfaces (p < 0.05). Intergroup comparisons revealed no significant differences (p > 0.05). Based on individual perceptions, CHX had better taste and biofilm control, but resulted in a greater change in taste. Nevertheless, MEL demonstrated anti-inflammatory effects similar to those of CHX. Further clinical trials testing different protocols, concentrations and follow-up periods are required to establish its clinical application.

Efficacy of oil pulling therapy with coconut oil on four-day supragingival plaque growth: A randomized crossover clinical trial.

OBJECTIVES: The aim of this study was to evaluate the plaque-inhibiting effects of oil pulling using 4- day plaque regrowth study model compared to 0.2% chlorhexidine gluconate (CHX) containing mouthrinse. DESIGN: The study was an observer-masked, randomized, cross-over design clinical trial, involving 29 volunteers to compare 0.2% CHX and oil pulling therapy in a 4- day plaque regrowth model. After the preparatory period, in which the subjects received professional prophylaxis, the subjects commenced rinsing with their allocated rinsed. On day 5 plaque index (PI), gingival index (GI), stain index (SI), bleeding on probing (BOP) were recorded from the subjects. Each participant underwent a 14- day wash out period and then used the other mouthrinse for four days. RESULTS: Oil pulling therapy presented similar inhibitory activity on plaque regrowth compared with CHX (PI = 1.67 ±â€¯0.24, 1.61 ±â€¯0.20, respectively) with less staining (SI = 0.21 ±â€¯0.13, 0.47 ±â€¯0.27, respectively). In addition, GI and BOP was similar in both groups (p > 0.05). CONCLUSION: Oil pulling with coconut oil seems to have similar plaque inhibition activity as CHX. In addition it caused less tooth staining than CHX. These findings suggest that oil pulling therapy may be an alternative to CHX rinse.

Control of bacterial and fungal biofilms by natural products of Ziziphus joazeiro Mart. (Rhamnaceae).

The aim of this study is to verify the action of the aqueous leaf extract Ziziphus joazeiro in the eradication of bacterial and fungal biofilms, and to compare these effects with the stem bark extracts, as well as with conventional standard drugs. The presence of secondary metabolites was observed through phytochemical prospection assays. The effect of the aqueous extract on microbial biofilm formation was observed by OD600 nm absorbance and the crystal violet assay. For bacterial and fungal biofilms, chlorhexidine gluconate and fluconazole, respectively, were used as positive controls. Phytochemical characterization showed the presence of secondary metabolite classes common to both extracts such as flavonoids, steroids and saponins. In particular, in the aqueous leaf extract phenols, condensed tannins and alkaloids were observed. Eradication results using the aqueous leaf extract showed an inhibition of the microbial biofilm mass, moreover the biofilms were more sensitive to the bark extract, which presented a greater inhibition number and an action similar to standard drugs. It is important to highlight the leaf extract showed significant eradication at the lowest concentrations for mature yeast biofilms, thus demonstrating its potential to modify microbial resistance susceptibility. Bacterial and fungal biofilm eradication results using the Ziziphus joazeiro aqueous extracts presented a biofilm inhibition effect for both, moreover the results support the ethnopharmacological knowledge surrounding the use of Ziziphus joazeiro stems in the community. In comparison, the bark extract presented a more effective treatment than the leaf extract against biofilms, presenting inhibition levels similar to the used standard drugs.

The effect of three different solutions on preventing oral mucositis in cancer patients undergoing stem cell transplantation: a non-randomized controlled trial: A Turkish study - NON-RANDOMISED TRIAL.

OBJECTIVE: To evaluate the effect of different solutions administered to patients undergoing stem cell transplantation on oral mucositis. METHODS: The non-randomised controlled trial was conducted at a Istanbul Medipol Mega university hospital in Turkey between May 2014 and June 2016, and comprised patients undergoing stem cell transplantation. They were divided into three groups. Group 1 had patients using chlorhexidine gluconate and benzydamine hydrochloride solution. Group 2 had those using calcium and phosphate solution. Group 3 patients were using black mulberry syrup. Data was collected using a structured questionnaire and the World Health Organisation mucositis assessment scale. Assessment was done on days 7, 14 and 21. Clinical significance of oral solutions was statistically determined. RESULTS: Of the 83 patients, 30(36%) were in group 1, 28(34%) in group 2, and 25(30%) in group 3. On day 7, there was no significant difference in terms of grades among the groups (p>0.05). On day 14, grade 2 mucositis was seen in 2(8%) patents in group 3, 5(17.9%) in group 2 and 5(16.7%) in group 1; Grade 3 mucositis was seen in 2(6.7%) patients in group 1, but none in the other two groups. On day 21, grade 3 mucositis was present in 2(8.0%) in group 3, 2(7.1%) in group 2, and 4(13.3%) in group 1. CONCLUSIONS: The use of black mulberry and calcium-phosphate solutions was found to be beneficial in preventing and treating oral mucositis.

In vitro evaluation of Eugenia dysenterica in primary culture of human gingival fibroblast cells.

Eugenia dysenterica is a Brazilian tree investigated for its properties and bioactive compounds, which are believed to have both pharmacological and phytochemical therapeutic effects. The leaves of this tree contain tannins, flavonoids, terpenes, and saponins, with reportedly beneficial effects to the human body. Despite these therapeutic applications, its effects have never been tested on oral tissues. Therefore, the aim of the present study was to evaluate the cytotoxic and antioxidant effects and the anti-inflammatory and repair properties of the acetone fraction of E. dysenterica on primary culture of human gingival fibroblasts and on the immortalized murine macrophage cell line (RAW 264.7). For this purpose, a metabolic activity assay, a wound healing assay, a nitric oxide assay, and RT-qPCR were performed. The assays revealed a cytoprotective effect of this plant, suggested by the increase in the expression of SOD1 and NRF2. An antioxidant potential effect was observed in the DPPH• assay. However, the fraction of E. dysenterica did not show anti-inflammatory activity. In conclusion, Eugenia dysenterica may promote cytoprotection when associated with chlorhexidine digluconate because of its antioxidant effect. However, additional studies are necessary on other human dental tissues using other parts of the plant in order to develop a possible mouthwash to assist patients with oral disorders.

Comparison of anti-peritoneal fibrotic effects between an mTORC1-specific blocker and a PI3K/mTOR dual-blocker.

OBJECTIVE: To compare the anti-peritoneal fibrotic effects between a mammalian target of rapamycin complex 1-specific blocker and a phosphatidyl-inositol 3-kinase/mammalian target of rapamycin dual-blocker. METHODS: A total of 40 male Sprague-Dawley rats were randomly divided into five groups with eight animals per group. The normal group (N group) did not receive any intervention. The normal saline group (NS group) received an intraperitoneal injection of normal saline at 1 ml/100 g daily. The model group (3 W group), rapamycin (RAPA) group and BEZ235 (PI3K/mTOR dual-blocker) group all received an intraperitoneal injection of 0.1% chlorhexidine gluconate at 1 ml/100g daily. And the RAPA and BEZ235 groups also received a 0.5 mg/d RAPA or 2.5 mg/d BEZ235 gavage every day, respectively. Rats in each group were sacrificed after 3 weeks. RESULTS: Immunohistochemistry, real-time PCR and western blotting analysis of fibrosis-related indicators (FN, Col 1, and α-SMA) confirmed that RAPA and BEZ235 significantly inhibited peritoneal fibrosis and that these two drugs had similar effects. The p-Akt, p-mTOR, p-p70S6K expression levels were significantly up-regulated in the 3 W group compared to the NS group, confirming that the mTOR pathway was significantly activated during peritoneal fibrosis. RAPA significantly inhibited the phosphorylation of mTOR and p70S6K but did not have significant effects on p-Akt upstream of mTOR. BEZ235 had significant inhibitory effects on all signaling molecules (p-Akt, p-mTOR, and p-p70S6K) in the mTOR pathway. CONCLUSION: RAPA did not up-regulate p-Akt in a negative feedback fashion. Both drugs effectively inhibited peritoneal fibrosis.

Could chlorhexidine be an adequate positive control for antimicrobial photodynamic therapy in- in vitro studies?

BACKGROUND: Chlorhexidine digluconate (CHX) is commonly applied as positive control of new antimicrobials, because it is considered the gold-standard for chemical plaque control. The aim of this study was to compare the effect of treatments with curcumin-mediated aPDT and CHX in relation to the viability of specific microorganism groups in two distinct times (immediately and 24 h later). METHODS: Dentin caries microcosms were grown on bovine dentin discs (37 °C, anaerobiosis) for 3 days in the Active Attachment Amsterdam Biofilm Model. The biofilms were treated with 300 µM curcumin and 75 J.cm-² LED, or 0.06% and 0.12% CHX. Then, total microorganisms, total streptococci, mutans streptococci, and total lactobacilli counts were determined. The statistical analysis was conducted by Kruskal-Wallis and post-hoc Dunn's tests (P < 0.05). RESULTS: Curcumin-mediated aPDT (C + L+), 0.06% and 0.12% CHX reduced mutans streptococci counts (0.19, 0.10 and 0.07 log10 respectively) in the immediate analysis. After 24 h, it was observed a re-growth of microorganisms treated by curcumin-mediated aPDT, whereas both CHX concentrations demonstrated a decrease of the viable microorganisms. CONCLUSION: This study confirmed the substantive effect of CHX and the immediate effect of aPDT. The use of a neutralizer solution was important to block the substantivity of CHX and permit its fair comparison with aPDT, allowing its use as a positive control in further studies.

Dual 0.02% chlorhexidine digluconate - 0.1% disodium EDTA loaded thermosensitive ocular gel for Acanthamoeba keratitis treatment.

Poor bioavailability and low residence time limit the efficiency of conventional biguanide-based eye drops against Acanthamoeba keratitis. The aim of this work was to formulate an original anti-amoebic thermoreversible ocular gel combining biguanide and metalloproteases inhibitor - chelating agent. Chlorhexidine digluconate (CHX)-ethylenediaminetetraacetic acid disodium salt (Na2EDTA) were compounded in poloxamer 407 saline solution. 0.02% CHX - 0.1% Na2EDTA loaded thermosensitive ocular gel exhibited appropriate pH (5.73 ±â€¯0.06), iso-osmolality (314 ±â€¯5 mOsm/kg), viscosity (ranged between 15 and 25 mPa.s) and thermal gelation (26.5 °C and 33 °C) properties. Bioadhesion of gel was successfully tested onto isolated bovine eyes as well as the assessment of CHX penetration into the cornea. Intracorneal CHX concentration was found greater than trophozoite minimum amoebicidal concentration and minimal cysticidal concentration after 15-min and 2-h ocular exposure, respectively, while any CHX permeation through the cornea was detected (<51 ng/cm2/h). Improvement of CHX ocular bioavailability was attributed to probable solubilization of tear film lipid layer by poloxamer. In vitro efficiency of CHX-Na2EDTA ocular gel was confirmed from the drastic reduction of trophozoite and cyst survival (to 25% and 2%, respectively), confirming the potential of the multicomponent pharmaceutical material strategy for the treatment of Acanthamoeba keratitis.

In vitro evaluation of Eugenia dysenterica in primary culture of human gingival fibroblast cells

Abstract: Eugenia dysenterica is a Brazilian tree investigated for its properties and bioactive compounds, which are believed to have both pharmacological and phytochemical therapeutic effects. The leaves of this tree contain tannins, flavonoids, terpenes, and saponins, with reportedly beneficial effects to the human body. Despite these therapeutic applications, its effects have never been tested on oral tissues. Therefore, the aim of the present study was to evaluate the cytotoxic and antioxidant effects and the anti-inflammatory and repair properties of the acetone fraction of E. dysenterica on primary culture of human gingival fibroblasts and on the immortalized murine macrophage cell line (RAW 264.7). For this purpose, a metabolic activity assay, a wound healing assay, a nitric oxide assay, and RT-qPCR were performed. The assays revealed a cytoprotective effect of this plant, suggested by the increase in the expression of SOD1 and NRF2. An antioxidant potential effect was observed in the DPPH• assay. However, the fraction of E. dysenterica did not show anti-inflammatory activity. In conclusion, Eugenia dysenterica may promote cytoprotection when associated with chlorhexidine digluconate because of its antioxidant effect. However, additional studies are necessary on other human dental tissues using other parts of the plant in order to develop a possible mouthwash to assist patients with oral disorders.

Effect of povidone iodine, chlorhexidine digluconate and toyocamycin on amphizoic amoebic strains, infectious agents of Acanthamoeba keratitis - a growing threat to human health worldwide.

INTRODUCTION: Free-living amoebae, ubiquitous in outer environments, in predisposing circumstances may exist as parasites, infectious agents of Acanthamoeba keratitis. In recent decades, the vision-threatening corneal infection is a growing human health threat worldwide, including Poland. The applied therapy is often ineffective due to diagnostic mistakes, various pathogenicity of Acanthamoeba strains and high resistance of cysts to drugs; many agents with possible anti-amoebic activity are still being tested. In the presented study, selected chemicals are investigated in terms of their in vitro effect on corneal and environmental Acanthamoeba strains. MATERIAL AND METHODS: Samples of a corneal isolate from a patient with severe Acanthamoeba keratitis,of assessed on the basis of genotype associations of 18S rRNA and the type strain, Acanthamoeba castellanii Neff cultivated in bacteria-free condition, were exposed to povidone iodine, chlorhexidine digluconate or toyocamycin. In vitro population dynamics of the strains were monitored and compared to those of control cultures. RESULTS: All chemicals showed anti-amoebic effects with different degrees of effectiveness. Significant differences were observed in the in vitro population dynamics, and the morpho-physiological status of A. castellanii Neff T4 and corneal strains determined as A. polyphaga T4 genotype, exposed to povidone iodine or toyocamycin, in comparison with chlorhexidine taken as reference. CONCLUSIONS: Time-dependent amoebstatic in vitro effects were demonstrated for all agents, in particular, the results of assays with povidone iodine are promising. No significant stimulation of encystation appeared; however, as cysticidal efficacy of chemicals is expected, complementary research is needed on different Acanthamoeba strains with modified agent concentrations and method application.

Evaluation of the antibacterial efficacy of various root canal disinfection methods against Enterococcus faecalis biofilm. An ex-vivo study.

BACKGROUND: Complete elimination of bacteria and their by-products from the root canal system is very difficult with current techniques. The purpose of this study was to compare the antibacterial efficacy of different disinfection protocols against Enterococcus faecalis (E. faecalis) biofilms. METHODS: Seventy-six extracted single-rooted human teeth were selected. Root canal preparation was done by proTaper rotary instruments. The smear layer was removed by 17% EDTA, followed by 5.25% sodium hypochlorite. After sterilization using gamma irradiation, sterilized specimens were inoculated with an E. faecalis suspension, incubated for 4 days and 4 weeks and then randomly divided into two experimental groups (4 days, 4 weeks old biofilms). After the confirmation of biofilm formation with SEM, the specimens in the experimental groups were randomly divided into five experimental subgroups according to the method of disinfection applied, which included: Diode laser irradiation (810 nm, 2 W), Light activated disinfection (LAD) with Indocyanine Green, 0.2% Chlorhexidine gluconate (0.2% CHX), 0.2% CHX + LAD and 0.2% CHX + Diode groups. RESULTS: Complete biofilm bacterial elimination was not observed in either of the experimental groups. CHX + LAD (0.2%) method exhibited the highest reduction value in biofilm and only Diode alone revealed the lowest in all the root canal portions. Disinfection protocols also showed significantly lower antibacterial efficacy against 4-week old than the 4-day old matured biofilms (P < 0.05). CONCLUSION: All the evaluated methods in this study were effective in the relative elimination of the E. faecalis biofilms except diode laser alone. Nevertheless, 0.2% CHX + LAD exhibited significantly higher efficacy in reducing both 4-day and 4-week old biofilms.

Growth Media Affect Assessment of Antimicrobial Activity of Plant-Derived Polyphenols.

This study aimed to investigate the effects of different microbial growth media on the laboratory assessment of antimicrobial activity of natural polyphenolic compounds. The inhibition of the tea polyphenol EGCG on growth of selected oral microorganisms was evaluated in complex media and a protein-free chemically defined medium (CDM). Other antimicrobial agents (polyphenolic grape seed extract, plant alkaloid berberine, methyl salicylate, and chlorhexidine gluconate) were also tested in the study. The presence of proteins and their effects on the antimicrobial activity of EGCG were investigated by the addition of BSA to the CDM. The MICs of EGCG against test oral microorganisms were 4 to 64 times higher in complex media than in CDM. The polyphenolic grape seed extract exhibited similar discrepancies. However, the MICs of the nonpolyphenolic compounds (berberine, methyl salicylate, and chlorhexidine) were not significantly different between the two growth media. The MIC of EGCG against S. mutans UA159 in CDM with added BSA was 16 times higher than that in CDM alone. Therefore, nonproteinaceous CDM should be used to avoid interference of proteins with the active ingredients when testing the antimicrobial activity of plant-derived polyphenolic compounds against microorganisms. This will also minimize the discrepancies noted in results obtained by different investigators.

Chlorhexidine bathing and Clostridium difficile infection in a surgical intensive care unit.

BACKGROUND: Clostridium difficile is the most common causative pathogen for hospital-acquired infections in the intensive care unit. This study evaluated the effect of chlorhexidine bathing every other day in preventing hospital-acquired C. difficile infection (CDI) using data from the CHlorhexidine Gluconate BATHing (CHG-BATH) randomized trial. METHODS: The primary endpoint was the proportion of patients acquiring CDIs among patients at risk for incident CDIs. Infections detected >48 h after randomization were classified as incident CDIs. Infections detected before or within 48 h of randomization were classified as prevalent CDIs. RESULTS: Of 38 patients (11.7%) who met criteria for potential CDI and underwent adjudication, 24 (7.4%) received oral or enema vancomycin, 18 (5.5%) had a positive C. difficile molecular assay, 14 (4.3%) received an International Classification of Diseases, Ninth Revision, Clinical Modification code for CDI, and 2 (0.6%) had possible pseudomembranous colitis on histopathology reports. The prevalence of CDI was 3.7% (6 of 164) in the soap and water arm and 4.3% (7 of 161) in the chlorhexidine arm. Compared with daily soap and water bathing, 2% chlorhexidine bathing every other day was not associated with the prevention of hospital-acquired CDI (1.3% [2 of 152] soap and water versus 2.0% [3 of 148] chlorhexidine, P = 0.68). CONCLUSIONS: It is inconclusive if there was an association between chlorhexidine bathing and incidence of CDI among surgical intensive care unit patients in this study as statistical power was limited. There are limited published data evaluating the association between chlorhexidine bathing and CDI, and this study provides data for future systematic reviews and meta-analyses.