Benzethonium Research Articles

High prevalence of qacA/B carriage among clinical isolates of meticillin-resistant Staphylococcus aureus in Malaysia

The minimum inhibitory concentrations (MICs) of 60 meticillin-resistant Staphylococcus aureus (MRSA) isolates from Malaysia to three antiseptic agents - benzalkonium chloride (BZT), benzethonium chloride (BAC) and chlorhexidine digluconate (CHG) - were determined. All isolates had MICs ranging from 0.5 to 2 mg/L. Antiseptic resistance genes qacA/B and smr were detected in 83.3% and 1.6% of the isolates, respectively. Carriage of qacA/B correlated with reduced susceptibility to CHG and BAC. This is the first report of the prevalence of qacA/B and smr gene carriage in Malaysian MRSA isolates, with a high frequency of qacA/B carriage. The presence of these antiseptic resistance genes and associated reduced susceptibility to antiseptic agents may have clinical implications.

Improvement and characterization of surfactant-modified Prussian blue screen-printed carbon electrodes for selective H2O2 detection at low applied potentials

The development of a highly selective and sensitive H2O2 sensor, based on the electro-deposition of Prussian blue (PB) onto screen-printed carbon electrodes (SPCEs) modified by benzethonium chloride (BZTC), is described. This methodology provides a time-efficient method for producing stable films in the presence of a BZTC concentration which was optimized with respect to electrochemical and electroanalytical properties. Some parameters such as the amount of PB deposited, film thickness, reversibility, permeability, stability, electrocatalytic properties and sensitivity to H2O2 were considered in order to select the optimal sensor. Under optimal conditions (2mM BZTC), the surface coverage and apparent diffusion coefficient for K+ displayed values of 6.4±0.2×10−8molcm−2 and 5.2×10−11cm2s−1, respectively, one order of magnitude higher than without surfactant. The catalytic rate constant for the optimized film was 2.8×103M−1s−1 which was in good agreement with data found in the literature. BZTC(2mM)/PB operating at ∼0V vs. SCE displayed the highest H2O2 sensitivity (1.07±0.03AM−1cm−2, n=5) reported in the literature to date for PB-modified SPCEs, and showed an excellent limit of detection (<10−7M) and linearity range (up to ∼1.5mM). Sensors incorporating BZTC were significantly more stable in media containing Na+ ions, even at neutral pH, than unmodified devices, critical properties for sensor applications in biological environments. Finally, BZTC(2mM)/PB-based sensors stored dry at room temperature over 4months retained the ∼90% of their initial response to H2O2, a useful property for commercial applications.

Dose-response Evaluation Using an Epidermal Model, an Alternative to Skin Irritation Testing

Using 3-dimensional cultured human skin and epidermal models, an alternative to skin irritation testing have been developed. In the ECVAM (European Centre for the Validation of Alternative Methods) validation protocol, hazardous chemicals have been identified using these models. We considered it likely that these models would also be useful for examining the dose-response of the toxicity of a chemical. Therefore, we used the epidermal model (Labcyte, Japan Tissue Engineering Co. Ltd.) to evaluate the dose-response of cytotoxicity and compared the findings with those for irritancy by human patch testing of 4 chemicals: sodium lauryl sulfate, benzethonium chloride, nonanoic acid and propylene glycol. The cytotoxicity of the chemicals was found to be stronger than the irritancy shown by human patch data. Difference ratios ranging from 1.4 to 52.7 were found between irritancy and EC50(concentration causing a 50% reduction in the MTT assay compared to the untreated control value) in LabCyte for 4 chemicals and solvents. We consider that these models are useful for evaluating the dose-response of skin irritancy, and could be used to establish a database for risk assessment of chemicals.

Potentials of Mouthwashes in Disinfecting Cariogenic Bacteria and Biofilms Leading to Inhibition of Caries

Objectives:The aim of this study was to compare the effects of certain commercially available mouthwashes on cariogenic bacteria and biofilms, following the acquisition of inhibition potentials of caries.Materials and Methods:Mouthwashes containing I) chlorhexidine gluconate (CHG; 0.0005% w/v), II) benzethonium chloride (BTC; 0.01% w/v), III) an essential oil (Listerine), and IV) povidone-iodine (PVP-I; 0.035% w/v) were tested on planktonic cariogenic bacteria, biofilms, and an ex vivo caries model. Bacterial aliquots were inoculated with each solution separately and vortexed for 10 seconds at room temperature. Bacterial viability was subsequently investigated by fluorescence microscopy (FM) after staining with a BacLight viability kit and the number of colony-forming units (CFUs) was counted. Similarly, mouthwash solutions were applied to artificial cariogenic biofilms, and bacterial viability of the biofilms was investigated as stated above. Inhibition potentials of two selected mouthwashes of carious lesions were investigated using biofilm-induced caries and a secondary caries model. In all steps, a phosphate-buffered saline (PBS) solution was included as a control.Results:Planktonic cariogenic bacteria and bacteria embedded in biofilms were killed in remarkably large numbers with Listerine and PVP-I treatment compared to PBS and other gargles. CFU counts also showed significant reduction after treatment with Listerine and PVP-I compared to other solutions (P<0.05). Listerine also displayed significant (P<0.05) inhibition effects in preventing the progression of demineralization.Conclusion:Bactericidal potencies of the mouthwashes varied significantly, suggesting that mouthwashes like Listerine can be useful for the prevention of caries and secondary caries.

Biocomposite films based on alginate and organically modified clay

Sodium alginate/sodium montmorillonite hybrid films were prepared by casting from the suspension of sodium alginate and different clay samples. Clay samples had been modified with a cationic surfactant, a cationic polymer, and a small polar molecule, respectively. Benzethonium chloride, polyethyleneimine and urea were used as clay modifiers. The composite films begin to disintegrate at a higher temperature and with less weight loss than the pure alginate films. This suggests an enhancement of the film thermal stability due to the modification of the alginate with clay samples.

Evaluation of Four Antiseptics Using a Novel Murine Norovirus

We isolated a novel murine norovirus (MNV), MT30-2 strain, from feces of conventional mice in Japan to evaluate the virucidal activity of four antiseptics. The MNV MT30-2 strain was inactivated by as little as 0.2% (w/v) povidone-iodine (PVP-I) and 0.1% (w/v) sodium hypochlorite (NaOCl) treatment as determined by a novel plaque assay. Importantly, PVP-I reduced the MNV titer by 4 log(10) within 15 s of exposure. The other two antiseptics, benzethonium chloride (BEC) and chlorhexidine gluconate (CHG), did not reduce the MNV titer even when treatment lasted for 60 s. When the virus titer was reduced by PVP-I or NaOCl treatment, the amount of MNV RNA was not reduced, indicating that the presence of viral RNA was not related to the virucidal activity of the antiseptics. PVP-I and NaOCl will be useful in controlling the spread of MNV, which is a common problem in mice colonies. In this study, we isolated a novel MNV and newly revealed that two antiseptics (PVP-I and NaOCl) were able to inactivate MNV at low concentrations and in a short contact time.

Two-Phase Titration Method for Cationic Surface Active Agents Determination with Use of 5-(3-Bromo-4-hydroxy-5-methoxyphenyl)-7,7-dimethyl-7H-indolo[1,2-a]quinolinium Perchlorate Dye

Abstract The direct two-phase titration method with use of solvatochromic dye, i. e. 5-(3-bromo-4-hydroxy-5-methoxyphenyl)-7,7-dimethyl-7H-indolo[1,2-a]quinolinium perchlorate (1) for cationic surfactants determination is presented which is the modification of an earlier described procedure for anionic surface active substances detection. The method was tested on standard solution of benzethonium chloride (cationic detergent) which enables to estimate its accuracy as well as on few commercially available products to verify its utility. The influence of pH value of the probe on the titration endpoint determination was discussed and a simple solution of this problem has been proposed.

Surfactant-promoted Prussian Blue-modified carbon electrodes: Enhancement of electro-deposition step, stabilization, electrochemical properties and application to lactate microbiosensors for the neurosciences

We report here for the first time a comparison of the beneficial effects of different cationic surfactants – cetyl trimethyl ammonium bromide (CTAB), benzethonium chloride (BZT) and cetylpyridinium chloride (CPC) – for the electrochemical synthesis of Prussian Blue (PB) films, using cyclic voltammetry (CV), on screen-printed carbon electrodes (SPCEs). Their electrochemical properties were investigated, paying special attention to parameters such as the amount of PB deposited, film thickness, charge transfer rate, permeability, reversibility, stability and sensitivity to hydrogen peroxide detection. All surfactant-enhanced PB-modified SPCEs displayed a significant improvement in their electrochemical properties compared with PB-modified SPCEs formed in the absence of surfactants. Surfactant-modified electrodes displayed a consistently higher PB surface concentration value of 2.1±0.4×10−8molcm−2 (mean±SD, n=3) indicating that PB deposition efficiency was improved 2–3 fold. K+ and Na+ permeability properties of the films were also studied, as were kinetic parameters, such as the surface electron transfer rate constant (ks) and the transfer coefficient (α). The hydrogen peroxide sensitivity of surfactant-modified PB films generated by 10 electro-deposition CV cycles gave values of 0.63AM−1cm−2, which is higher than those reported previously for SPCEs by other authors. Finally, the first lactate microbiosensor described in the literature based on BZT-modified PB-coated carbon fiber electrodes is presented. Its very small cross-section (∼10μm diameter) makes it particularly suitable for neuroscience studies in vivo.

Visual and confocal microscopic interpretation of patch tests to benzethonium chloride and benzalkonium chloride

Quaternary ammonium compounds (Quats), such as benzalkonium chloride (BAC) and benzethonium chloride (BEC), are widely used as antibacterial active ingredients and preservatives in personal care products, disinfectants, and ophthalmic preparations. BAC is known to be a marginal irritant when patch tested at 0.15% aq. Data on BEC are limited. To differentiate irritant from allergic patch test reactions to quaternary ammonium compounds. Eight subjects who were considered likely to react based on history of rash after exposure to disinfectants or a history of prior positive patch test to BAC were recruited, as well as two patients undergoing routine patch testing. BAC (0.15% aq), BAC (0.15% pet), BEC (0.05% aq), BEC (0.15% pet), BEC (0.15% aq), BEC (0.5% aq), sodium lauryl sulfate (2.0%), and deionized water were applied under Finn chambers for 48 h. Four days and 7 days after application, the sites were examined visually and then by in vivo reflectance confocal microscopy (RCM) which was interpreted by blinded experts. Two patients with definite allergic reactions according to visual patch test reads and RCM were clinically relevant. Cross-reaction between BEC and BAC was demonstrated in one patient. RCM imaging correlated well with clinical scoring and interpretation of patch test reactions in terms of irritancy vs. allergy for BEC and BAC. Relevant allergic reactions to quats occur in humans. Possible cross-reaction was noted to occur between BAC and BEC. RCM appears to be a useful tool in distinguishing between irritancy and sensitization during patch testing to BAC and BEC. Further study of prevalence and best test concentration and vehicle is needed.

Bactericidal activity of topical antiseptics and their gargles against Bordetella pertussis

Bordetella pertussis is the etiological agent of whooping cough, a common cause of respiratory illness in both children and adults. In the present study, we investigated the bactericidal activity of four antiseptics-povidone-iodine (PVP-I), benzethonium chloride (BEC), chlorhexidine gluconate (CHG) and benzalkonium chloride (BAC)-against B. pertussis ATCC9797 and clinical isolates. Among the topical antiseptics, PVP-I, BEC, and BAC, PVP-I and BAC in particular, showed high bactericidal activity, whereas CHG had low activity. PVP-I gargle also showed high bactericidal activity, similar to topical PVP-I. However, BEC gargle had low bactericidal activity. Our results indicate that topical PVP-I and BAC, and PVP-I gargle would be useful as effective antiseptics against B. pertussis.

The Composition of Mixed Micelles Formed by Dodecyl Trimethyl Ammonium Bromide and Benzethonium Chloride in Water

AbstractThe composition of the mixed micelles formed by benzethonium chloride and dodecyl trimethyl ammonium bromide in water were experimentally determined by a combination of surfactant ion‐selective electrodes and UV–Vis spectroscopy measurements. Results were compared with the computed compositions from three theories on mixed micelles available in the literature (Regular Solution, Motomura’ and Georgiev's). The basis of the Junquera and Aicart method and the determination of the micelle aggregation number (N) by pyrene fluorescence quenching, i.e., the constancy of N and the mixed micelle composition when the total concentration is changed, were not supported by our experimental results. Experimental micelle compositions were statistically equal to those computed by Regular Solution Theory. The mixed micelle composition and the quantity of non‐micellized surfactant molecules change with concentration above the critical micelle concentration, and therefore do not support the assumptions used in the Junquera and Aicart procedure and in the determination of N by pyrene fluorescence quenching. The reason why the latter procedure gives N values similar to those obtained from other techniques is discussed.

Study of Electrical Parameters and Energy Efficiency in Photogalvanic Cell Containing Erythrosine as a Photosensitizer in Benzethonium Chloride – EDTA System

Photogalvanic effect was studied in a photogalvanic cell containing Erythrosine as photosensitizer in Benzethonium Chloride EDTA system . A sintered filter was used in H-cell between the diffusion length. In Erythrosine - Benzethonium Chloride - EDTA system the photopotential and photocurrent were observed 890.0 mV and 250.0 mA respectively. The conversion efficiency of the system was observed 0.8282 % and fill factor was determined as 0.33. The cell performance was observed 95.0 minutes in dark. The effects of different parameters on the electrical output of the cell and current-voltage (i-V) characteristics of the cell were studied. A mechanism was also proposed for the generation of photocurrent in photogalvanic cell. Key words : Photogalvanic effect; Erythrosine; Benzethonium Chloride; Fill factor; Conversion efficiency

Physiological and transcriptional characterization of persistent and nonpersistent Listeria monocytogenes isolates.

This study aimed to characterize physiological differences between persistent and presumed nonpersistent Listeria monocytogenes strains isolated at processing facilities and to investigate the molecular basis for this by transcriptomic sequencing. Full metabolic profiles of two strains, one persistent and one nonpersistent, were initially screened using Biolog's Phenotype MicroArray (PM) technology. Based on these results, in which major differences from selected antimicrobial agents were detected, another persistent strain and two nonpersistent strains were characterized using two antimicrobial PMs. Resistance to quaternary ammonium compounds (QACs) was shown to be higher among persistent strains. Growth of persistent and nonpersistent strains in various concentrations of the QACs benzethonium chloride (BZT) and cetylpyridinium chloride (CPC) was determined. Transcriptomic sequencing of a persistent and a presumed nonpersistent strain was performed to compare gene expression among these strains in the presence and absence of BZT. Two strains, designated "frequent persisters" because they were the most frequently isolated at the processing facility, showed overall higher resistance to QACs. Transcriptome analysis showed that BZT induced a complex peptidoglycan (PG) biosynthesis response, which may play a key role in BZT resistance. Comparison of persistent and nonpersistent strains indicated that transcription of many genes was upregulated among persistent strains. This included three gene operons: pdu, cob-cbi, and eut. These genes may play a role in the persistence of L. monocytogenes outside the human host.

Identification of Specific Pluripotent Stem Cell Death—Inducing Small Molecules by Chemical Screening

A potential application of embryonic and inducible pluripotent stem cells for the therapy of degenerative diseases involves pure somatic cells, free of tumorigenic undifferentiated embryonic and inducible pluripotent stem cells. In complex collections of chemicals with pharmacological potential we expect to find molecules able to induce specific pluripotent stem cell death, which could be used in some cell therapy settings to eliminate undifferentiated cells. Therefore, we have screened a chemical library of 1120 small chemicals to identify compounds that induce specifically apoptotic cell death in undifferentiated mouse embryonic stem cells (ESCs). Interestingly, three compounds currently used as clinically approved drugs, nortriptyline, benzethonium chloride and methylbenzethonium chloride, induced differential effects in cell viability in ESCs versus mouse embryonic fibroblasts (MEFs). Nortriptyline induced apoptotic cell death in MEFs but not in ESCs, whereas benzethonium and methylbenzethonium chloride showed the opposite effect. Nortriptyline, a tricyclic antidepressant, has also been described as a potent inhibitor of mitochondrial permeability transition, one of two major mechanisms involved in mitochondrial membrane permeabilization during apoptosis. Benzethonium chloride and methylbenzethonium chloride are quaternary ammonium salts used as antimicrobial agents with broad spectrum and have also been described as anticancer agents. A similar effect of benzethonium chloride was observed in human induced pluripotent stem cells (hiPSCs) when compared to both primary human skin fibroblasts and an established human fibroblast cell line. Human fibroblasts and hiPSCs were similarly resistant to nortriptyline, although with a different behavior. Our results indicate differential sensitivity of ESCs, hiPSCs and fibroblasts to certain chemical compounds, which might have important applications in the stem cell-based therapy by eliminating undifferentiated pluripotent stem cells from stem cell-derived somatic cells to prevent tumor formation after transplantation for therapy of degenerative diseases.

Study and Development of Reversed-Phase HPLC Systems for the Determination of 2-Imidazolines in the Presence of Preservatives in Pharmaceutical Preparations

Different HPLC chromatographic systems were investigated on a C18 ACE 5 pm, 150 x 4.6 mm id column for the determination of tymazoline, tramazoline, and antazoline, with either naphazoline or xylometazoline, in commercial preparations. For the development and optimization of the systems, a Response Surface Method (r=0.925-0.980) was used to illustrate the changes in k as a function of pH values and different salt concentrations. The simultaneous separation of 2-imidazolines was accomplished at 40 degrees C with 0.01 M ammonium acetate-methanol (50+50, v/v, pH 6.0) mobile phase at a flow rate of 1.2 mL/min. In order to deal with the usual coexistence of 2-imidazolines with benzethonium and benzalkonium chloride preservatives, it was necessary to use another chromatographic system, 0.01 M ammonium acetate-methanol (50+50, v/v) mobile phase on a cyano ACE 5 pm, 150 x 4.6 mm id column. As part of a more thorough theoretical investigation, a partial least-squares (PLS) technique was used for modeling the RP-HPLC retention data. The model was based on molecular structure descriptors of the analytes' X variables and on their retention time (Log K) Y. The goodness of fit was estimated by the PLS correlation coefficient (r2) and root mean square error of estimation values, which were 0.994 and 0.0479, respectively.

Antibacterial Effect of Food Additives and Detergents against Histamine-Producing Bacteria on Food Contact Material Surfaces

We investigated the antibacterial activity of food additives and detergents against histamine-producing bacteria on food contact material surfaces. Based on minimum inhibitory concentration (MIC) testing with Morganella morganii NBRC3848, Raoultella planticola NBRC3317 and Enterobacter aerogenes NCTC10006, we screened nine food additives and four detergents with relatively high inhibitory potency. We prepared food contact material surfaces contaminated with histamine-producing bacteria, and dipped them into fourteen agents (100 µg/mL). Sodium hypochlorite, benzalkonium chloride, benzethonium chloride, n-hexadecyltrimethylammonium chloride and 1-n-hexadecylpyridinium chloride showed antibacterial activity against histamine-producing bacteria. We prepared low concentrations of the five agents (10 and 50 µg/mL) and tested them in the same way. Sodium hypochlorite showed high antibacterial activity at 10 µg/mL, and the other four showed activity at 50 µg/mL. So, washing the material surface with these reagents might be effective to prevent histamine food poisoning owing to bacterial contamination of food contact surfaces.

Benzalkonium bromide as a new potential instillation drug for bladder cancer: Hypothesis and pilot study

SummaryNon-muscle-invasive urothelial carcinoma of the bladder has a high rate of recurrence, necessitating use of a variety of adjuvant treatments. A single, immediate post-operative administration of chemotherapy is an important measure for reducing the rate of recurrences, but the overall effect is not satisfactory and the treatment is a burden to the patient. Hence, there is a need for a new, more effective and cheaper agent for adjuvant treatment of non-muscle-invasive bladder carcinomas.Although cationic surfactants such as benzalkonium salts are used clinically and hygienically for the control of bacterial growth, there have been reports that cationic surfactants such as benzethonium chloride induce apoptosis in normal and in cancerous cells. We report our experience with benzalkonium bromide (BB) accidentally administered into a patient‘s bladder as saline. It caused severe hematuria and pain, but after a week of persistent administration in the bladder, the patient was cured, as supported by evidence from cystoscopy, indicating that BB destroys bladder mucosa and suggesting that BB maybe a novel agent for use in a single, immediate post-operative administration. We present preliminary data to support this hypothesis and provide discussion we hope will be useful as the foundation for further experiments.

Adsorption of trace levels of bromate from aqueous solution by organo-montmorillonite

Organo-montmorillonite was prepared by the modification of montmorillonite (Mont) with cetylpyridinium chloride (CPC), benzethonium chloride (BC) or hexadecyl trimethylammonium chloride (HDTMAC) to study the adsorption of bromate from aqueous solutions. The adsorption from a 0.78μM bromate solution on CPC–Mont occurred rapidly. The equilibrium was attained within 2h at bromate concentrations <0.078μM, the maximum contaminant level established for drinking water. BC–Mont and HDTMAC–Mont were not effective for the adsorption of bromate in trace concentrations.

Benzethonium Increases the Cytotoxicity of S(+)-Ketamine in Lymphoma, Neuronal, and Glial Cells

Ketamine has been demonstrated to be neurotoxic in animals as well as in patients. Preservatives added to ketamine have been accused to induce this neurotoxicity. Therefore, we investigated whether the most widely used preservative of ketamine-benzethonium chloride-enhances the toxicity of S(+)-ketamine in vitro in lymphoma, neuroblastoma cells and primary astrocytes. Human Jurkat T-lymphoma- and neuroblastoma cells (SHEP) were incubated for 24 hours with commercially available S-ketamine containing benzethonium, pure S-ketamine and pure benzethonium chloride. The rate of early- and late-apoptotic cells was evaluated by flowcytometry. In a second step the combined toxicity of benzethonium and ketamine was investigated in neuroblastoma cells and primary rat astrocytes in a mitochondrial activity assay (XTT). The additivity of the toxicities was evaluated by employing isobolographic analysis. In Jurkat T-lymphoma and neuroblastoma cells benzethonium increased the toxicity of ketamine from 32% to 80% and from 64% to 84% cell deaths, respectively. In neuroblastoma cells as well as in primary rat astrocytes the measured combined toxicity was within the confidence interval of the calculated pure additive toxicity as seen in the isobolograms. We conclude that benzethonium increases the local toxicity of ketamine in cells of hematopoietic, neuronal and glial origin in an additive manner. Therefore, caution is recommended especially when using preservative containing S-ketamine as an additive for long-term neuraxial analgesia.

A Case of Naphazoline Intoxication after the Ingestion of a Topical Antiseptic Solution

Senepul™ solution is frequently used as a topical antiseptic solution in Korea in cases with abrasion, laceration and impetigo. 100 ml of this solution contains a mixture of 100 mg naphazoline hydrochloride, 100 mg dibucaine hydrochloride, 200 mg chlorpheniramine maleate, and 100 mg benzethonium chloride. Naphazoline is an alpha sympathomimetic and an imidazoline derivative. In excessive dosage or ingested by accident, naphazoline may cause not only local but also systemic side effects like hypertension, bradycardia with arrhythmia, hypotension, respiratory depression, excitation or severe central nervous system depression. We report a case of a patient with prolonged bradycardia, hypotension, central nervous system depression that occurred after ingestion of a small amount of this topical antiseptic solution.