Survival of Serratia marcescens in benzalkonium chloride and in multiple-dose medication vials: relationship to epidemic septic arthritis.

PubMed Central

Nakashima, A K; Highsmith, A K; Martone, W J

1987-01-01

In an epidemic of septic arthritis due to Serratia marcescens, the intra-articular injection of contaminated methylprednisolone may have played a key role. The epidemic strain was found in used multiple-dose vials of methylprednisolone and in a canister of cotton balls soaked in benzalkonium chloride. The cotton balls had been used for antisepsis and disinfection. Growth characteristics of the epidemic strain of S. marcescens were compared with those of control strains of S. marcescens which had been obtained from unrelated nosocomial outbreaks. The epidemic strain was able to survive in 1:100 dilutions of benzalkonium chloride and was able to grow to greater than 10(5) CFU/ml in multiple-dose vials of methylprednisoline; control strains could not be recovered after 24 h in the same solutions. The preservative in methylprednisolone is gamma-myristyl picolinium chloride, a compound chemically related to benzalkonium chloride. We speculate that the epidemic strain of S. marcescens, which was resistant to benzalkonium chloride, had cross-resistance to gamma-myristyl picolinium chloride. If the cotton balls were used to disinfect the tops of the multiple-dose vials of methylprednisolone, small numbers of organisms subsequently introduced into the solution could have grown to high concentrations. PMID:3298309

Ocular toxicity of beta-blockers and benzalkonium chloride in pigmented rabbits: electrophysiological and morphological studies.

PubMed

Chou, A; Hori, S; Takase, M

1985-01-01

Subconjunctival injection of 0.2 ml of the following solutions was carried out once a day for two weeks in the albino and pigmented rabbit: commercial 0.5% timolol or 1% befunolol ophthalmic solutions, both containing benzalkonium chloride, and also these drug solutions containing no preservative, ophthalmic base solutions containing benzalkonium chloride, physiological saline solution or phosphate buffer solution. One week after daily injections of the commercial drug solutions or base solutions with benzalkonium chloride, the electroretinogram (ERG) showed a marked reduction in the a- and b-wave amplitudes in the pigmented rabbit, but the ERG changes were slight in the albino rabbit. After two weeks of injections, histological studies of the pigmented rabbit eyes revealed retinal detachment, visual cell loss and atrophy of the retinal pigment epithelium and choroid; the changes in the albino rabbit eyes were minimal. Injections of the beta-blockers containing no benzalkonium resulted in no significant changes in the ERG or in the tissue structures of all rabbits. Injections of only physiological saline or phosphate buffer had no deleterious effects. Therefore, the ocular toxicity of the beta-blockers was thought to be minor and the toxic effects seen in this study were thought to be due to benzalkonium chloride, which possibly accumulates in the ocular pigments.

Assessment of the efficacy of benzalkonium chloride and sodium hypochlorite against Acanthamoeba polyphaga and Tetrahymena spp.

PubMed

Vaerewijck, M J M; Sabbe, K; Baré, J; Spengler, H-P; Favoreel, H W; Houf, K

2012-03-01

The efficacy of benzalkonium chloride and sodium hypochlorite against Acanthamoeba polyphaga and two Tetrahymena spp. was determined based on the European Standard EN 1276:2009 suspension test. Trophozoite viability was assessed by determination of the membrane integrity using flow cytometry as a fast screening technique. Bovine serum albumin was added to simulate clean (0.3 g/liter) and dirty (3 g/liter) conditions. Benzalkonium chloride caused cell lysis at concentrations above 50 mg/liter under clean and dirty conditions. A concentration of 50 mg of free chlorine per liter had a strong biocidal effect on acanthamoebae and tetrahymenae after 15 min under clean and dirty conditions. Our results suggest that benzalkonium chloride and sodium hypochlorite were effective against the three microorganisms at concentrations commonly applied in the food industry.

Development and validation of a rapid ultra-high performance liquid chromatography method for the assay of benzalkonium chloride using a quality-by-design approach.

PubMed

Mallik, Rangan; Raman, Srividya; Liang, Xiaoli; Grobin, Adam W; Choudhury, Dilip

2015-09-25

A rapid robust reversed-phase UHPLC method has been developed for the analysis of total benzalkonium chloride in preserved drug formulation. A systematic Quality-by-Design (QbD) method development approach using commercial, off the shelf software (Fusion AE(®)) has been used to optimize the column, mobile phases, gradient time, and other HPLC conditions. Total benzalkonium chloride analysis involves simple sample preparation. The method uses gradient elution from an ACE Excel 2 C18-AR column (50mm×2.1mm, 2.0μm particle size), ammonium phosphate buffer (pH 3.3; 10mM) as aqueous mobile phase and methanol/acetonitrile (85/15, v/v) as the organic mobile phase with UV detection at 214nm. Using these conditions, major homologs of the benzalkonium chloride (C12 and C14) have been separated in less than 2.0min. The validation results confirmed that the method is precise, accurate and linear at concentrations ranging from 0.025mg/mL to 0.075mg/mL for total benzalkonium chloride. The recoveries ranged from 99% to 103% at concentrations from 0.025mg/mL to 0.075mg/mL for total benzalkonium chloride. The validation results also confirmed the robustness of the method as predicted by Fusion AE(®). Copyright © 2015 Elsevier B.V. All rights reserved.

Gene expression in Listeria monocytogenes exposed to sublethal concentration of benzalkonium chloride.

PubMed

Tamburro, Manuela; Ripabelli, Giancarlo; Vitullo, Monia; Dallman, Timothy James; Pontello, Mirella; Amar, Corinne Francoise Laurence; Sammarco, Michela Lucia

2015-06-01

In this study, tolerance at sublethal concentration of benzalkonium chloride and transcription levels of mdrL, ladR, lde, sigB and bcrABC genes in Listeria monocytogenes strains were evaluated. Viable cells reduction occurred in 45% of strains and clinical isolates showed lower sensitivity than isolates from foods. An increased transcription of an efflux system encoding gene was found in 60% of strains, and simultaneous mdrL overexpression and ladR underexpression occurred in 30% of isolates. A significant association between reduced benzalkonium chloride activity and both mdrL and sigB overexpression was observed; sigB expression also correlated with both mdrL and ladR genes. The bcrABC gene was only found in six strains, all isolated from foods and sensitive to benzalkonium chloride, and in four strains an underexpression was observed. Disinfection at sublethal concentration was less effective in clinical isolates, and mdrL and sigB expression was significantly affected by disinfection. Further insights are needed to understand the adaptation to benzalkonium chloride and to evaluate whether changes in gene expression could affect the L. monocytogenes virulence traits and persistence in the environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

In vitro cytotoxic effects of benzalkonium chloride in corticosteroid injection suspension.

PubMed

Davis, Daniel; Cyriac, Mathew; Ge, Dongxia; You, Zongbing; Savoie, Felix H

2010-01-01

Some deleterious effects on cartilage and even severe arthropathy have been reported after intra-articular corticosteroid injections. The objective of the present in vitro study was to determine if an injectable corticosteroid suspension is toxic to articular chondrocytes and synovial cells. Human and bovine articular chondrocytes, bovine synovial cells, mouse C3H10T1/2 cells, and human osteosarcoma MG-63 cells were treated for thirty minutes in monolayer or suspension culture with an injectable corticosteroid suspension or its chemical components, including betamethasone sodium phosphate, betamethasone acetate, and benzalkonium chloride (as preservative). Cell viability was determined by means of microscopy or flow cytometry analysis. In monolayer culture, the betamethasone corticosteroids per se did not cause cell death, whereas benzalkonium chloride caused death of articular chondrocytes. In suspension culture, betamethasone sodium phosphate at dosages of as high as 6 mg/mL did not cause significant death of human or bovine articular chondrocytes (p > 0.05). In contrast, benzalkonium chloride caused a death rate of 10.6% in human articular chondrocytes at a dosage of 10 microg/mL (p < 0.01), 21.0% at a dosage of 13.3 microg/mL (p < 0.01), and 99.3% and 99.4% at dosages of 20 and 200 microg/mL, respectively (p < 0.001 for both). Similarly, benzalkonium chloride caused death of bovine articular chondrocytes, bovine synovial cells, C3H10T1/2 cells, and MG-63 cells in a dose-dependent manner. When treated with a combination of betamethasone sodium phosphate and 200 microg/mL benzalkonium chloride, >99% of human or bovine articular chondrocytes were dead (p < 0.001). The injectable corticosteroid suspension caused death in in vitro culture of human and bovine articular chondrocytes as well as bovine synovial cells because of its preservative benzalkonium chloride. The betamethasone corticosteroids per se did not cause significant chondrocyte death under the conditions tested.

Genomic and post-genomic effects of anti-glaucoma drugs preservatives in trabecular meshwork.

PubMed

Izzotti, Alberto; La Maestra, Sebastiano; Micale, Rosanna Tindara; Longobardi, Maria Grazia; Saccà, Sergio Claudio

2015-02-01

Oxidative stress plays an important role in glaucoma. Some preservatives of anti-glaucoma drugs, commonly used in glaucoma therapy, can prevent or induce oxidative stress in the trabecular meshwork. The aim of this study is to evaluate cellular and molecular damage induced in trabecular meshwork by preservatives contained in anti-glaucoma drugs. Cell viability (MTT test), DNA fragmentation (Comet test), oxidative DNA damage (8-oxo-dG), and gene expression (cDNA microarray) have been evaluated in trabecular meshwork specimens and in human trabecular meshwork cells treated with benzalkonium chloride, polyQuad, purite, and sofzia-like mixture. Moreover, antimicrobial effectiveness and safety of preservative contents in drugs was tested. In ex vivo experiments, benzalkonium chloride and polyQuad induced high level of DNA damage in trabecular meshwork specimens, while the effect of purite and sofzia were more attenuated. The level of DNA fragmentation induced by benzalkonium chloride was 2.4-fold higher in subjects older than 50 years than in younger subjects. Benzalkonium chloride, and polyQuad significantly increased oxidative DNA damage as compared to sham-treated specimens. Gene expression was altered by benzalkonium chloride, polyQuad, and purite but not by sofzia. In in vitro experiments, benzalkonium chloride and polyQuad dramatically decreased trabecular meshwork cell viability, increased DNA fragmentation, and altered gene expression. A lesser effect was also exerted by purite and sofzia. Genes targeted by these alterations included Fas and effector caspase-3. The efficacy of the preservatives in inhibiting bacterial growth increased the adverse effects in trabecular meshwork in terms of DNA damage and alteration of gene expression. Presented data indicates the delicate balance between efficacy and safety of drug preservatives as not yet optimized. Copyright © 2014 Elsevier B.V. All rights reserved.

Predictive Studies Suggest that the Risk for the Selection of Antibiotic Resistance by Biocides Is Likely Low in Stenotrophomonas maltophilia

PubMed Central

Sánchez, María Blanca; Decorosi, Francesca; Viti, Carlo; Oggioni, Marco Rinaldo; Martínez, José Luis; Hernández, Alvaro

2015-01-01

Biocides are used without restriction for several purposes. As a consequence, large amounts of biocides are released without any control in the environment, a situation that can challenge the microbial population dynamics, including selection of antibiotic resistant bacteria. Previous work has shown that triclosan selects Stenotrophomonas maltophilia antibiotic resistant mutants overexpressing the efflux pump SmeDEF and induces expression of this pump triggering transient low-level resistance. In the present work we analyze if two other common biocides, benzalkonium chloride and hexachlorophene, trigger antibiotic resistance in S. maltophilia. Bioinformatic and biochemical methods showed that benzalkonium chloride and hexachlorophene bind the repressor of smeDEF, SmeT. Only benzalkonium chloride triggers expression of smeD and its effect in transient antibiotic resistance is minor. None of the hexachlorophene-selected mutants was antibiotic resistant. Two benzalkonium chloride resistant mutants presented reduced susceptibility to antibiotics and were impaired in growth. Metabolic profiling showed they were more proficient than their parental strain in the use of some dipeptides. We can then conclude that although bioinformatic predictions and biochemical studies suggest that both hexachlorophene and benzalkonium chloride should induce smeDEF expression leading to transient S. maltophilia resistance to antibiotics, phenotypic assays showed this not to be true. The facts that hexachlorophene resistant mutants are not antibiotic resistant and that the benzalkonium chloride resistant mutants presenting altered susceptibility to antibiotics were impaired in growth suggests that the risk for the selection (and fixation) of S. maltophilia antibiotic resistant mutants by these biocides is likely low, at least in the absence of constant selection pressure. PMID:26201074

Fourteen-year survival of Pseudomonas cepacia in a salts solution preserved with benzalkonium chloride.

PubMed Central

Geftic, S G; Heymann, H; Adair, F W

1979-01-01

A strain of Pseudomonas cepacia that survived for 14 years (1963 to 1977) as a contaminant in an inorganic salt solution which contained commercial 0.05% benzalkonium chloride (CBC) as an antimicrobial preservative, was compared to a recent clinical isolate of P. cepacia. Ammonium acetate was present in the concentrated stock CBC solution, and served as a carbon and nitrogen source for growth when carried over into the salts solution with the CBC. The isolate's resistance to pure benzalkonium chloride was increased step-wise to a concentration of 16%. Plate counts showed 4 x 10(3) colony-forming units per ml in the salts solution. Comparison of growth rates, mouse virulence, antibiotics resistance spectra, and substrate requirements disclosed no differences between the contaminant and a recently isolated clinical strain of P. cepacia. The results indicate that it is critical that pharmaceutical solutions containing benzalkonium chloride as an antimicrobial preservative be formulated without extraneous carbon and nitrogen sources or be preserved with additional antimicrobial agents. PMID:453827

Determination of Benzalkonium Chloride in Commercial Disinfectant Formulations by Quantitative NMR Spectroscopy

DTIC Science & Technology

2012-11-01

disinfectant solutions containing benzalkonium chloride (BAC); a molluscicide and antifouling chemical. In order to determine the efficacy of this...formulations. The methods and results presented herein will be used in a separate study to assess the efficacy of BACs as antifouling agents under

Preparation of active antibacterial LDPE surface through multistep physicochemical approach: I. Allylamine grafting, attachment of antibacterial agent and antibacterial activity assessment.

PubMed

Bílek, František; Křížová, Táňa; Lehocký, Marián

2011-11-01

Low-density polyethylene (LDPE) samples were treated in air plasma discharge, coated by polyallyamine brush thought copolymeric grafting surface-from reaction and deposited four common antibacterial agents (benzalkonium chloride, bronopol, chlorhexidine and triclosan) to gain material with active antibacterial properties. Surface characteristics were evaluated by static contact angle measurement with surface energy evaluation ATR-FTIR, X-ray Photoelectron Spectroscopy (XPS) and SEM analysis. Inhibition zone on agar was used as in vitro test of antibacterial properties on two representative gram positive Staphylococcus aureus (S. aureus) and gram negative Escherichia coli (E. coli) strains. It was confirmed, that after grafting of polyallyamine, more antibacterial agent is immobilized on the surface. The highest increase of antibacterial activity was observed by the sample containing triclosan. Samples covered by bronopol did not show significant antibacterial activity. Copyright © 2011 Elsevier B.V. All rights reserved.

Safety and acceptability of vaginal disinfection with benzalkonium chloride in HIV infected pregnant women in west Africa: ANRS 049b phase II randomized, double blinded placebo controlled trial. DITRAME Study Group

PubMed Central

Msellati, P.; Meda, N.; Leroy, V.; Likikouet, R.; Van de Perre, P.; Cartoux, M.; Bonard, D.; Ouangre, A.; Combe, P.; Gautier-Charpenti..., L.; Sylla-Koko, F.; Lassalle, R.; Dosso, M.; Welffens-Ekra, C.; Dabis, F.; Mandelbrot, L.

1999-01-01

OBJECTIVES: To study the tolerance and acceptability in Africa of a perinatal intervention to prevent vertical HIV transmission using benzalkonium chloride disinfection. DESIGN: A randomized, double blinded phase II trial. SETTING: Prenatal care units in Abidjan (Cote d'Ivoire) and Bobo-Dioulasso (Burkina Faso). PATIENTS: Women accepting testing and counselling who were seropositive for HIV-1 and under 37 weeks of pregnancy were eligible. A total of 108 women (54 in each group) enrolled from November 1996 to April 1997, with their informed consent. INTERVENTION: Women self administered daily a vaginal suppository of 1% benzalkonium chloride or matched placebo from 36 weeks of pregnancy, and a single intrapartum dose. The neonate was bathed with 1% benzalkonium chloride solution or placebo within 30 minutes after birth. MAIN OUTCOME MEASURES: Adverse events were recorded weekly, with a questionnaire and speculum examination in women through delivery, and examination of the neonate through day 30. The incidence of genital signs and symptoms in the women and cutaneous or ophthalmological events in newborns were compared between groups on an intent to treat basis. RESULTS: The median duration of prepartum treatment was 21 days (range 0-87 days). Compliance was 87% for prepartum and 69% for intrapartum treatment, and 88% for the neonatal bath, without differences between the two groups. In women, the most frequent event was leucorrhoea; the incidence of adverse events did not differ between treatment groups. In children, the incidence of dermatitis and conjunctivitis did not differ between the benzalkonium chloride and placebo groups (p = 0.16 and p = 0.29, respectively). CONCLUSION: Vaginal disinfection with benzalkonium chloride is a feasible and well tolerated intervention in west Africa. Its efficacy in preventing vertical HIV transmission remains to be demonstrated. 


 PMID:10754950

Pseudomonas aeruginosa cells adapted to benzalkonium chloride show resistance to other membrane-active agents but not to clinically relevant antibiotics.

PubMed

Loughlin, M F; Jones, M V; Lambert, P A

2002-04-01

Our objective was to determine whether strains of Pseudomonas aeruginosa can adapt to growth in increasing concentrations of the disinfectant benzalkonium chloride (BKC), and whether co-resistance to clinically relevant antimicrobial agents occurs. Attempts were made to determine what phenotypic alterations accompanied resistance and whether these explained the mechanism of resistance. Strains were serially passaged in increasing concentrations of BKC in static nutrient broth cultures. Serotyping and genotyping were used to determine purity of the cultures. Two strains were examined for cross-resistance to other disinfectants and antibiotics by broth dilution MIC determination. Alterations in outer membrane proteins and lipopolysaccharide (LPS) expressed were examined by SDS-PAGE. Cell surface hydrophobicity and charge, uptake of disinfectant and proportion of specific fatty acid content of outer and cytoplasmic membranes were determined. Two P. aeruginosa strains showed a stable increase in resistance to BKC. Co-resistance to other quaternary ammonium compounds was observed in both strains; chloramphenicol and polymyxin B resistance were observed in one and a reduction in resistance to tobramycin observed in the other. However, no increased resistance to other biocides (chlorhexidine, triclosan, thymol) or antibiotics (ceftazidime, imipenem, ciprofloxacin, tobramycin) was detected. Characteristics accompanying resistance included alterations in outer membrane proteins, uptake of BKC, cell surface charge and hydrophobicity, and fatty acid content of the cytoplasmic membrane, although no evidence was found for alterations in LPS. Each of the two strains had different alterations in phenotype, indicating that such adaptation is unique to each strain of P. aeruginosa and does not result from a single mechanism shared by the whole species.

Effect of benzalkonium chloride on the stability of the precorneal tear film in rabbit and man.

PubMed Central

Wilson, W. S.; Duncan, A. J.; Jay, J. L.

1975-01-01

Benzalkonium chloride, a surface-active preservative commonly used in eyedrop preparations, has been shown to hasten the drying of the precorneal tear film. In the rabbit, 0.01 per cent benzalkonium (the concentration usually employed as a preservative) shortened the time required for the appearance of dry spots on the corneal surface by a factor of about four. In man, an approximately twofold hastening was demonstrated. This effect is thought to preclude the use of this substance as a preservative in eyedrop preparations for use as local anaesthetics. PMID:1203224

Effects of Benzalkonium Chloride on Planktonic Growth and Biofilm Formation by Animal Bacterial Pathogens

PubMed Central

Ebrahimi, Azizollah; Hemati, Majid; Shabanpour, Ziba; Habibian Dehkordi, Saeed; Bahadoran, Shahab; Lotfalian, Sharareh; Khubani, Shahin

2015-01-01

Background: Resistance toward quaternary ammonium compounds (QACs) is widespread among a diverse range of microorganisms and is facilitated by several mechanisms such as biofilm formation. Objectives: In this study, the effects of benzalkonium chloride on planktonic growth and biofilm formation by some field isolates of animal bacterial pathogens were investigated. Materials and Methods: Forty clinical isolates of Escherichia coli, Salmonella serotypes, Staphylococcus aureus and Streptococcus agalactiae (10 isolates of each) were examined for effects of benzalkonium chloride on biofilm formation and planktonic growth using microtiter plates. For all the examined strains in the presence of benzalkonium chloride, biofilm development and planktonic growth were affected at the same concentrations of disinfectant. Results: The means of strains growth increase after the minimal inhibitory concentration (MIC) were significant in all the bacteria (except for E. coli in 1/32 and S. agalactiae in of 1/8 MIC). Biofilm formation increased with decrease of antiseptics concentration; a significant increase was found in all the samples. The most turbidity related to S. aureus and the least to Salmonella. Conclusions: Bacterial resistance against quaternary ammonium compounds is increasing which can increase the bacterial biofilm formation. PMID:25793094

Effect of zinc and benzalkonium chloride on Nitrosomonas communis and potential nitrification in soil.

PubMed

Frühling, W; Rönnpagel, K; Ahlf, W

2001-10-01

A bacterial contact assay is described which uses a chemoautotrophic microorganism, Nitrosomonas communis (strain Nm2) to evaluate the biological effect of contaminated soils. The effects of two toxicants on the ammonium oxidation activity of the autochthonous microbial population in the soil are compared with inhibition of the same biological response in the new monospecies bioassay. Experiments were performed using soil samples dosed with organic and inorganic contaminants (benzalkonium chloride and zinc) to demonstrate the mode of operation and the sensitivity of the bioassay. The EC50 values of zinc and benzalkonium chloride were calculated to be 171 and 221 mg kg-1 soil, respectively. The toxic response provided by the bioassay can thus predict the effect of soil pollutants on the autochthonous nitrifying bacteria.

Disinfectant susceptibility of different Salmonella serotypes isolated from chicken and egg production chains.

PubMed

Long, M; Lai, H; Deng, W; Zhou, K; Li, B; Liu, S; Fan, L; Wang, H; Zou, L

2016-09-01

The study aimed to serotype the Salmonella isolates recovered from chicken and egg production chains, and to investigate the disinfectant resistance phenotypes and genotypes of these isolates. The Salmonella isolates were serotyped, and the minimal inhibitory concentrations (MICs) of disinfectants were determined. Results showed that the Salmonella isolates recovered from both chains were diverse, and the serotypes in each part of the production chain and between the two production chains were significantly different. In the chicken production chain, 19 different serotypes were recovered, while only five serotypes were found in the egg production chain. The isolates showed a high susceptibility to didecyldimethylammonium bromide (DDAB) but a low susceptibility to benzalkonium chloride (BC), benzalkonium bromide (BAB) and chlorhexidine (CHX). Salmonella Enteritidis and Salmonella Typhimurium were more resistant to BC and BAB. The qacEΔ1 and qacF resistance genes were detected in 26·7 and 7·7% of the isolates respectively. The qacEΔ1 gene was frequently found in Salmonella Derby and Salm. Enteritidis (P < 0·05). Our findings indicated that Salmonella was commonly present in both chains, and could serve as a critical vector in spreading disinfectant resistance associated with different serotypes. This study first demonstrated disinfectant resistance phenotypes and genotypes of serotyped Salmonella. The study highlights the need for monitoring the disinfectant resistance varied in different Salmonella serotypes. © 2016 The Society for Applied Microbiology.

Effect of enterocin AS-48 in combination with biocides on planktonic and sessile Listeria monocytogenes.

PubMed

Gómez, Natacha Caballero; Abriouel, Hikmate; Grande, M A José; Pulido, Rubén Pérez; Gálvez, Antonio

2012-05-01

Enterocin AS-48 was tested on a cocktail of Listeria monocytogenes strains in planktonic and sessile states, singly or in combination with biocides benzalkonium chloride, cetrimide, hexadecylpyridinium chloride, didecyldimethylammonium bromide, triclosan, poly-(hexamethylen guanidinium) hydrochloride, chlorhexidine, hexachlorophene, and the commercial sanitizers P3 oxonia and P3 topax 66. Combinations of sub-inhibitory bacteriocin concentrations and biocide concentrations 4 to 10-fold lower than their minimum inhibitory concentrations (MIC) completely inhibited growth of the planktonic listeriae. Inactivation of Listeria in biofilms formed on polystyrene microtiter plates required concentrations of enterocin AS-48 greater than 50 μg/ml, and biocide concentrations ten to 100-fold higher. In combination with enterocin AS-48 (25 or 50 μg/ml), microbial inactivation increased remarkably for all biocides except P3 oxonia and P3 topax 66 solutions. Polystyrene microtiter plates conditioned with enterocin solutions (0.5-25 μg/ml) decreased the adherence and biofilm formation of the L. monocytogenes cell cocktail, avoiding biofilm formation for at least 24 h at a bacteriocin concentration of 25 μg/ml. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Eye Drop Preservative Benzalkonium Chloride Potently Induces Mitochondrial Dysfunction and Preferentially Affects LHON Mutant Cells.

PubMed

Datta, Sandipan; Baudouin, Christophe; Brignole-Baudouin, Francoise; Denoyer, Alexandre; Cortopassi, Gino A

2017-04-01

Benzalkonium chloride (BAK) is the most commonly used eye drop preservative. Benzalkonium chloride has been associated with toxic effects such as "dry eye" and trabecular meshwork degeneration, but the underlying biochemical mechanism of ocular toxicity by BAK is unclear. In this study, we propose a mechanistic basis for BAK's adverse effects. Mitochondrial O2 consumption rates of human corneal epithelial primary cells (HCEP), osteosarcoma cybrid cells carrying healthy (control) or Leber hereditary optic neuropathy (LHON) mutant mtDNA [11778(G>A)], were measured before and after acute treatment with BAK. Mitochondrial adenosine triphosphate (ATP) synthesis and cell viability were also measured in the BAK-treated control: LHON mutant and human-derived trabecular meshwork cells (HTM3). Benzalkonium chloride inhibited mitochondrial ATP (IC50, 5.3 μM) and O2 consumption (IC50, 10.9 μM) in a concentration-dependent manner, by directly targeting mitochondrial complex I. At its pharmaceutical concentrations (107-667 μM), BAK inhibited mitochondrial function >90%. In addition, BAK elicited concentration-dependent cytotoxicity to cybrid cells (IC50, 22.8 μM) and induced apoptosis in HTM3 cells at similar concentrations. Furthermore, we show that BAK directly inhibits mitochondrial O2 consumption in HCEP cells (IC50, 3.8 μM) at 50-fold lower concentrations than used in eye drops, and that cells bearing mitochondrial blindness (LHON) mutations are further sensitized to BAK's mitotoxic effect. Benzalkonium chloride inhibits mitochondria of human corneal epithelial cells and cells bearing LHON mutations at pharmacologically relevant concentrations, and we suggest this is the basis of BAK's ocular toxicity. Prescribing BAK-containing eye drops should be avoided in patients with mitochondrial deficiency, including LHON patients, LHON carriers, and possibly primary open-angle glaucoma patients.

The Eye Drop Preservative Benzalkonium Chloride Potently Induces Mitochondrial Dysfunction and Preferentially Affects LHON Mutant Cells

PubMed Central

Datta, Sandipan; Baudouin, Christophe; Brignole-Baudouin, Francoise; Denoyer, Alexandre; Cortopassi, Gino A.

2017-01-01

Purpose Benzalkonium chloride (BAK) is the most commonly used eye drop preservative. Benzalkonium chloride has been associated with toxic effects such as “dry eye” and trabecular meshwork degeneration, but the underlying biochemical mechanism of ocular toxicity by BAK is unclear. In this study, we propose a mechanistic basis for BAK's adverse effects. Method Mitochondrial O2 consumption rates of human corneal epithelial primary cells (HCEP), osteosarcoma cybrid cells carrying healthy (control) or Leber hereditary optic neuropathy (LHON) mutant mtDNA [11778(G>A)], were measured before and after acute treatment with BAK. Mitochondrial adenosine triphosphate (ATP) synthesis and cell viability were also measured in the BAK-treated control: LHON mutant and human-derived trabecular meshwork cells (HTM3). Results Benzalkonium chloride inhibited mitochondrial ATP (IC50, 5.3 μM) and O2 consumption (IC50, 10.9 μM) in a concentration-dependent manner, by directly targeting mitochondrial complex I. At its pharmaceutical concentrations (107–667 μM), BAK inhibited mitochondrial function >90%. In addition, BAK elicited concentration-dependent cytotoxicity to cybrid cells (IC50, 22.8 μM) and induced apoptosis in HTM3 cells at similar concentrations. Furthermore, we show that BAK directly inhibits mitochondrial O2 consumption in HCEP cells (IC50, 3.8 μM) at 50-fold lower concentrations than used in eye drops, and that cells bearing mitochondrial blindness (LHON) mutations are further sensitized to BAK's mitotoxic effect. Conclusions Benzalkonium chloride inhibits mitochondria of human corneal epithelial cells and cells bearing LHON mutations at pharmacologically relevant concentrations, and we suggest this is the basis of BAK's ocular toxicity. Prescribing BAK-containing eye drops should be avoided in patients with mitochondrial deficiency, including LHON patients, LHON carriers, and possibly primary open-angle glaucoma patients. PMID:28444329

Inactivation of Viruses by Benzalkonium Chloride

PubMed Central

Armstrong, J. A.; Froelich, E. J.

1964-01-01

Benzalkonium chloride (as Roccal or Zephiran) was found to inactivate influenza, measles, canine distemper, rabies, fowl laryngotracheitis, vaccinia, Semliki Forest, feline pneumonitis, meningopneumonitis, and herpes simplex viruses after 10 min of exposure at 30 C or at room temperature. Poliovirus and encephalomyocarditis virus were not inactivated under the same conditions. It was concluded that all viruses tested were sensitive except members of the picorna group. The literature was reviewed. PMID:4288740

The effect of different mouth rinse products on intra-oral halitosis.

PubMed

Erovic Ademovski, S; Lingström, P; Renvert, S

2016-05-01

To evaluate the effect of different mouth rinses 12 h after rinsing on genuine intra-oral halitosis. Twenty-four adults with halitosis were included in a double-blind, crossover, randomized clinical trial. Halitosis was evaluated 12 h after rinsing with placebo and five mouth rinse products containing zinc acetate and chlorhexidine diacetate; zinc lactate, chlorhexidine and cetylpyridinium chloride; zinc acetate and chlorhexidine diacetate with reduced amounts of mint and menthol; zinc chloride and essential oil; and chlorine dioxide using the organoleptic method and a gas chromatograph. Test periods were separated by 1 week. Hydrogen sulphide (H2 S), methyl mercaptan (MM) and the organoleptic scores (OLS) were significantly reduced 12 h following rinsing with all substances compared to placebo (P < 0.05). H2 S was more effectively reduced after rinsing with zinc acetate and chlorhexidine diacetate and zinc acetate and chlorhexidine diacetate with reduced amounts of mint and menthol compared to rinsing with zinc chloride and essential oil (P < 0.05), and significantly lower values of MM were obtained after rinsing with zinc acetate and chlorhexidine diacetate compared to zinc lactate, chlorhexidine and cetylpyridinium chloride (P < 0.05). The percentage effectively treated individuals (H2 S (<112 ppb), MM (<26 ppb) and OLS score <2) varied from 58% percentage (zinc acetate and chlorhexidine diacetate) to 26% (zinc chloride and essential oil). All treatments resulted in reduction in halitosis 12 h after rinsing compared to placebo. H2 S and MM were most effectively reduced by zinc acetate and chlorhexidine diacetate. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Multicenter study of preservative sensitivity in patients with suspected cosmetic contact dermatitis in Korea.

PubMed

Lee, Sang S; Hong, Dong K; Jeong, Nam J; Lee, Jeung H; Choi, Yun-Seok; Lee, Ai-Young; Lee, Cheol-Heon; Kim, Kea J; Park, Hae Y; Yang, Jun-Mo; Lee, Ga-Young; Lee, Joon; Eun, Hee C; Moon, Kee-Chan; Seo, Seong J; Hong, Chang K; Lee, Sang W; Choi, Hae Y; Lee, Jun Y

2012-08-01

As many new cosmetic products are introduced into the market, attention must be given to contact dermatitis, which is commonly caused by cosmetics. We investigate the prevalence of preservative allergy in 584 patients with suspected cosmetic contact dermatitis at 11 different hospitals. From January 2010 to March 2011, 584 patients at 11 hospital dermatology departments presented with cosmetic contact dermatitis symptoms. These patients were patch-tested for preservative allergens. An irritancy patch test performed on 30 control subjects using allergens of various concentrations showed high irritancy rates. Preservative hypersensitivity was detected in 41.1% of patients. Allergens with the highest positive test rates were benzalkonium chloride (12.1%), thimerosal (9.9%) and methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) (5.5%). Benzalkonium chloride and chlorphenesin had the highest irritancy rate based on an irritancy patch test performed using various concentrations. Seven of 30 normal subjects had a positive irritant patch reading with 0.1% benzalkonium chloride and eight of 30 normal subjects had a positive irritant patch reading at 4 days with 0.5% chlorphenesin in petrolatum. Although benzalkonium chloride was highly positive for skin reactions in our study, most reactions were probably irritation. MCI/MI and thimerosal showed highly positive allergy reactions in our study. The optimum concentration of chlorphenesin to avoid skin reactions is less than 0.5%. © 2012 Japanese Dermatological Association.

Method and Apparatus for Preventing Biofouling of Surfaces

DTIC Science & Technology

2011-06-14

ammonium compounds that are suitable for this purpose include benzalkonium chloride , benzethonium chloride , methylbenzethonium chloride , cetalkonium... chloride , cetylpyridinium chloride , cetrimonium, cetrimide, dofanium chloride , tetraethylammonium bromide, didecyldimethylammonium chloride and domiphen...upon layers of impermeable nano-particles cause diffusing molecules to follow a tortuous, 8 slow path that results in a huge reduction in

Evaluation of antibiofilm effect of benzalkonium chloride, iodophore and sodium hypochlorite against biofilm of Pseudomonas aeruginosa of dairy origin.

PubMed

Pagedar, Ankita; Singh, Jitender

2015-08-01

The present study was undertaken with objectives of; a) to investigate and compare Pseudomonas aeruginosa isolates from two dairies for biofilm formation potential and, b) to compares three common biocides for biofilm eradication efficiencies. Amongst the isolates from commercial dairy, 70 % were strong and/or moderate biofilm former in comparison to 40 % isolates from small scale dairy. All isolates, irrespective of source, exhibited higher susceptibility to biocides in planktonic stage than in biofilm. Antibiofilm efficiencies of three biocides i.e. benzalkonium chloride, sodium hypochlorite and iodophore were determined in terms of their microbial biofilms eradicating concentration (MBEC). Our findings show that the three biocides were ineffective against preformed biofilms at recommended in-use concentrations. Biofilms were the most resistant to benzalkonium chloride and least against iodophore. A trend of decreasing MBECs was observed with extended contact time. The findings of present study warrant for a systematic approach for selecting types and concentrations of biocide for application as antibiofilm agent in food industry.

In vitro evaluation of benzalkonium chloride in the preservation of adhesive interfaces.

PubMed

Sabatini, C; Kim, J H; Ortiz Alias, P

2014-01-01

Inhibition of endogenous dentin matrix metalloproteinases (MMPs) by benzalkonium chloride (BAC) decreases collagen solubilization and may help improve resin-dentin bond stability. This study evaluated the resin-dentin bond stability of experimental adhesive blends containing BAC and the stability of dentin matrices by assessing the mass loss and collagen solubilization from dentin beams pretreated with BAC. Twenty-five healthy molars were used for the bond strength evaluation of a two-step etch-and-rinse adhesive (Adper Single Bond Plus, SB) modified with BAC or not. The following groups were tested: 1) SB with no inhibitor (control); 2) topical 2.0% chlorhexidine + SB; 3) 1.0% BAC etchant + SB; 4) 0.5% BAC-SB; and 5) 1.0% BAC-SB. Microtensile bond strength (μTBS) and failure mode distribution under standard error of the mean were evaluated after 24 hours and six months of storage in artificial saliva (AS). A two-way analysis of variance and Tukey test with a significance level of p<0.05 was used for data analysis. In addition, 30 completely demineralized dentin beams from human molars were either dipped in deionized water (DW, control) or dipped in 0.5% and 1.0% BAC for 60 seconds, and then incubated in AS. Collagen solubilization was assessed by evaluating the dry mass loss and quantifying the amount of hydroxyproline (HYP) released from hydrolyzed specimens after four weeks of incubation. The control group demonstrated lower μTBS than some of the experimental groups containing BAC at 24 hours and six months (p<0.05). When BAC was incorporated into the adhesive blend in concentrations of 0.5% and 1.0%, no reduction in dentin bond strength was observed after six months (p<0.05). Less mass loss and HYP release was seen for dentin matrices pretreated with BAC relative to the control pretreated with DW (p<0.05). This in vitro study demonstrates that BAC contributes to the preservation of resin-dentin bonds by reducing collagen degradation.

Aspergilli Response to Benzalkonium Chloride and Novel-Synthesized Fullerenol/Benzalkonium Chloride Nanocomposite

PubMed Central

Unković, Nikola; Ljaljević Grbić, Milica; Stupar, Miloš; Vukojević, Jelena; Janković, Vesna; Jović, Danica; Djordjević, Aleksandar

2015-01-01

A comprehensive comparative analysis of antifungal potential of benzalkonium chloride and newly synthesized fullerenol/benzalkonium chloride nanocomposite was conducted to assess the possible impact of carbon-based nanocarrier on antimicrobial properties of the commonly used biocide. Physical characterization of synthesized nanocomposite showed zeta potential of +37.4 mV and inhomogeneous particles size distribution, with nanocomposite particles' dimensions within 30–143 nm and maximum number of particles at 44 nm. The effect of pure and fullerenol nanocarrier-bound biocide was evaluated in eight Aspergillus species. In mycelial growth assay, nanocomposite was more potent, as fungicidal effect of 1.04/0.6 μg mL−1 was obtained in all but one of the isolates (A. niger), while proportional concentration of pure biocide (0.6 μg mL−1) completely inhibited mycelial growth of only three Aspergillus species. However, conidia appear to be less susceptible to nanocomposite treatment, as lower fungistatic (MIC) and fungicidal (MFC) concentrations were obtained with biocide alone (MIC in range from 0.03 to 0.15 μg mL−1 and MFC from 0.075 to 0.45 μg mL−1). To a different degree, both substances stimulated aflatoxin B1 production and inhibited ochratoxin A synthesis. Very low mycelium biomass yield, in range from 1.0 to 3.0 mg dry weight, was documented in both biocide and nanocomposite enriched medium. PMID:26295057

Propionibacterium acnes Has Low Susceptibility to Chlorhexidine Digluconate.

PubMed

Nakase, Keisuke; Fukushima, Hanae; Yukawa, Tomoko; Nakaminami, Hidemasa; Fujii, Takeshi; Noguchi, Norihisa

2018-04-01

The skin bacterium Propionibacterium acnes has been reported to be responsible for surgical site infections (SSIs). Skin disinfection before surgery therefore is of the utmost importance in the prevention of SSIs caused by skin bacteria. We assessed the susceptibility of clinical isolates of two skin bacteria, P. acnes and Staphylococcus epidermidis, to disinfectants. The range of chlorhexidine digluconate (CHG) minimum inhibitory concentrations (MICs) for P. acnes isolates was 0.25-1 mcg/mL. Furthermore, the minimum bactericidal concentrations (MBCs) for a range of disinfectants were determined to evaluate their rapid bactericidal activity. The MBC range of CHG against the P. acnes isolates was 4,096->32,768 mcg/mL (MBC 80 16,384 mcg/mL) after one minute of exposure and 1,024-32,768 mcg/mL (MBC 80 8,192 mcg/mL) after five minutes, indicating that some strains required a CHG MBC higher than the commercial concentration of 2% (20,000 mcg/mL). In contrast, the MBCs of glutaraldehyde, sodium hypochlorite, povidone-iodine, ethanol, benzalkonium chloride, and olanexidine gluconate were all sufficiently lower than their commercial concentrations. In S. epidermidis, the MBC range of CHG was 128-1,024 mcg/mL at one minute of exposure and 4-8 mcg/mL at five minutes. Different skin bacteria have different susceptibilities to disinfectants. To prevent SSIs, the selected disinfectant agent and the disinfection time should have bactericidal activity toward all the bacteria that pose a risk of infection.

Correlation between antibiotic and biocide resistance in mesophilic and psychrotrophic Pseudomonas spp. isolated from slaughterhouse surfaces throughout meat chain production.

PubMed

Lavilla Lerma, Leyre; Benomar, Nabil; Casado Muñoz, María del Carmen; Gálvez, Antonio; Abriouel, Hikmate

2015-10-01

The aim of this study was to evaluate biocide susceptibility in mesophilic and psychrotrophic pseudomonads isolated from surfaces of a goat and lamb slaughterhouse, which was representative of the region. To determine biocide resistance in pseudomonads, we determined for the first time the epidemiological cut-off values (ECOFFs) of benzalkonium, cetrimide, chlorhexidine, hexachlorophene, P3 oxonia, polyhexamethylene guanidine hydrochloride (PHMG), topax 66 and triclosan being generally very similar in different Pseudomonas spp. with some exceptions. Thus, resistance of pseudomonads was mainly shown to triclosan, and in lesser extent to cetrimide and benzalkonium chloride depending on the species, however they were highly susceptible to industrial formulations of biocides. By means of statistical analysis, positive correlations between antibiotics, biocides and both antimicrobials in pseudomonads were detected suggesting a co- or cross resistance between different antimicrobials in goat and lamb slaughterhouse environment. Cross-resistance between biocides and antibiotics in pseudomonads were especially detected between PHMG or triclosan and different antibiotics depending on the biocide and the population type. Thus, the use of those biocides as disinfectant in slaughterhouse zones must be carefully evaluated because of the selection pressure effect of antimicrobials on the emergence of resistant bacteria which could be spread to the consumer. It is noteworthy that specific industrial formulations such as topax 66 and oxonia P3 showed few correlations with antibiotics (none or 1-2 antibiotics) which should be taken into consideration for disinfection practices in goat and lamb slaughterhouse. Copyright © 2015 Elsevier Ltd. All rights reserved.

Use of glutaraldehyde and benzalkonium chloride for minimizing post-harvest physio-chemical and microbial changes responsible for sucrose losses in sugar cane.

PubMed

Singh, Pushpa; Arya, Namita; Tiwari, Priyanka; Suman, Archna; Rai, R K; Shrivastava, A K; Solomon, S

2008-08-27

Sugar cane is sensitive to enormous sucrose losses induced by physio-chemical and microbial changes, the severity being increased during the time lag between harvest and crushing in the mills. Minimization of the sucrose losses in the field is essential for better sugar recovery and prevention of sucrose losses. An experiment was conducted to evaluate the efficacy of glutaraldehyde and benzalkonium chloride for their effects on the microbial counts and physio-chemical changes responsible for sucrose losses. Glutaraldehyde and benzalkonium chloride (1000 + 250 ppm) reduced the losses in sucrose content to 7.1% as compared to the 30.8% loss in the control, thus improving the performance by 76.9%. The application of chemicals reduced the acid invertase activity (by 60%), lowered weight loss, titrable acidity, reducing sugars content, dextran, ethanol, and ethylene production and respiration rates. The application led to the reduction in the total bacterial, fungal, Leuconostoc, and yeast counts by 67.92, 51.3%, 26.08, and 51.2%, respectively.

Benzalkonium chloride neutralizes the irritant effect of sodium dodecyl sulfate.

PubMed

McFadden, J P; Holloway, D B; Whittle, E G; Basketter, D A

2000-11-01

When benzalkonium chloride (BKC), a cationic surfactant, is added to sodium dodecyl sulfate (SDS), an anionic surfactant, and used in patch testing, on the basis of their known physicochemical interaction, it is possible to predict that there will be a tendency towards a reduction in the expected irritant response when compared to SDS alone. The aim of this study was to investigate whether BKC could reduce the irritant response to SDS when applied after the SDS exposure. 54 non-atopic adult volunteers were recruited for the study. 20% SDS was applied for 2 h under occlusion. 1% BKC was then applied to the same site. Various controls, including SDS application followed by water for 2 h, were included. The irritant reaction was assessed at 24 h and 48 h. 40 of the 54 subjects had some reaction when SDS was applied for 2 h followed by either benzalkonium chloride or water control under occlusion. In comparison to water control, where BKC was applied after SDS, 20 of the 40 responders had a weaker reaction but only 4 had a stronger response. This study shows that BKC applied to skin exposed to SDS attenuates the resulting irritant reaction.

Evaluation of several chemical disinfectants for removing zebra mussels from unionid mussels

USGS Publications Warehouse

Waller, D.L.; Fisher, S.W.

1998-01-01

We evaluated the safety and effectiveness of chemical treatments for killing veliger and juvenile stages of the zebra mussel Dreissena polymorpha attached to unionid mussels. Static toxicity tests were conducted on eight unionid mussel species with common aquaculture chemicals (benzalkonium chloride, formalin, hydrogen peroxide, calcium chloride, potassium chloride, and sodium chloride). The concentration and duration of each chemical treatment tested had previously been found to kill zebra mussel veligers and juveniles. Several species (e.g., Elliptio dilatata, Lampsilis cardium, and Lasmigona complanata) incurred less than 10% mortality in chloride salt treatments, while in other species (e.g., Obliquaria reflexa and Leptodea fragilis) mortality varied greatly among treatment regimes. Treatments with benzalkonium chloride, formalin, and hydrogen peroxide were less than 90% effective on juvenile stages of zebra mussels and, therefore, were ruled out after preliminary trials. Limited application of specific chemical treatments may be feasible for more tolerant species; however, effective disinfection of unionid shells will require the use of chemical treatment followed by a quarantine period to completely remove zebra mussel larvae and juveniles.

Listeria monocytogenes Strains Selected on Ciprofloxacin or the Disinfectant Benzalkonium Chloride Exhibit Reduced Susceptibility to Ciprofloxacin, Gentamicin, Benzalkonium Chloride, and Other Toxic Compounds▿

PubMed Central

Rakic-Martinez, Mira; Drevets, Douglas A.; Dutta, Vikrant; Katic, Vera; Kathariou, Sophia

2011-01-01

Listeria monocytogenes is a leading agent for severe food-borne illness and death in the United States and other nations. Even though drug resistance has not yet threatened therapeutic interventions for listeriosis, selective pressure associated with exposure to antibiotics and disinfectants may result in reduced susceptibility to these agents. In this study, selection of several L. monocytogenes strains on either ciprofloxacin (2 μg/ml) or the quaternary ammonium disinfectant benzalkonium chloride (BC; 10 μg/ml) led to derivatives with increased MICs not only to these agents but also to several other toxic compounds, including gentamicin, the dye ethidium bromide, and the chemotherapeutic drug tetraphenylphosphonium chloride. The spectrum of compounds to which these derivatives exhibited reduced susceptibility was the same regardless of whether they were selected on ciprofloxacin or on BC. Inclusion of strains harboring the large plasmid pLM80 revealed that MICs to ciprofloxacin and gentamicin did not differ between the parental and plasmid-cured strains. However, ciprofloxacin-selected derivatives of pLM80-harboring strains had higher MICs than those derived from the plasmid-cured strains. Susceptibility to the antimicrobials was partially restored in the presence of the potent efflux inhibitor reserpine. Taken together, these data suggest that mutations in efflux systems are responsible for the multidrug resistance phenotype of strains selected on ciprofloxacin or BC. PMID:22003016

Alkaline ionic liquids applied in supported ionic liquid catalyst for selective hydrogenation of citral to citronellal

PubMed Central

Salminen, Eero; Virtanen, Pasi; Mikkola, Jyri-Pekka

2014-01-01

The challenge in preparation of ionic liquids containing a strong alkaline anion is to identify a suitable cation which can tolerate the harsh conditions induced by the anion. In this study, a commercial quaternary ammonium compound (quat) benzalkonium [ADBA] (alkyldimethylbenzylammonium) was used as a cation in the synthesis of different alkaline ionic liquids. In fact, the precursor, benzalkonium chloride, is a mixture of alkyldimethylbenzylammonium chlorides of various alkyl chain lengths and is commonly used in the formulation of various antiseptic products. The prepared ionic liquids were utilized as Supported Ionic Liquid Catalysts (SILCAs). Typically, a SILCA contains metal nanoparticles, enzymes, or metal complexes in an ionic liquid layer which is immobilized on a solid carrier material such as an active carbon cloth (ACC). The catalysts were applied in the selective hydrogenation of citral to citronellal which is an important perfumery chemical. Interestingly, 70% molar yield toward citronellal was achieved over a catalyst containing the alkaline ionic liquid benzalkonium methoxide. PMID:24790972

Resistance of Pseudomonas to Quaternary Ammonium Compounds. I. Growth in Benzalkonium Chloride Solution

PubMed Central

Adair, Frank W.; Geftic, Sam G.; Gelzer, Justus

1969-01-01

Resistant cells of Pseudomonas aeruginosa and a waterborne Pseudomonas sp. (strain Z-R) were able to multiply in nitrogen-free minimal salts solution containing various concentrations of commercially prepared, ammonium acetate-buffered benzalkonium chloride (CBC), a potent antimicrobial agent. As the CBC concentration increased, growth increased until a point was reached at which the extent of growth leveled off or was completely depressed. Minimal salts solutions of pure benzalkonium chloride (PBC) containing no ammonium acetate did not support bacterial growth. When ammonium acetate was added to PBC solutions in the same concentrations found in CBC solutions, growth patterns developed that were comparable to those found with CBC. Likewise, (NH4)2SO4 added to PBC solutions supported growth of both organisms. P. aeruginosa was initially resistant to CBC levels of 0.02% and it was adapted to tolerate levels as high as 0.36%. Strain Z-R was naturally resistant to 0.4% CBC. Since ammonium acetate, carried over by the CBC used in drug formulations and disinfectant solutions, has the potential to support the growth of resistant bacteria and thus make possible the risk of serious infection, it is suggested that regulations allowing the presence of ammonium acetate in CBC solution be reconsidered. PMID:4984761

Biopolymer-modified graphite oxide nanocomposite films based on benzalkonium chloride-heparin intercalated in graphite oxide

NASA Astrophysics Data System (ADS)

Meng, Na; Zhang, Shuang-Quan; Zhou, Ning-Lin; Shen, Jian

2010-05-01

Heparin is a potent anticoagulant agent that interacts strongly with antithrombin III to prevent the formation of fibrin clots. In the present work, poly(dimethylsiloxane)(PDMS)/graphite oxide-benzalkonium chloride-heparin (PDMS/modified graphite oxide) nanocomposite films were obtained by the solution intercalation technique as a possible drug delivery system. The heparin-benzalkonium chloride (BAC-HEP) was intercalated into graphite oxide (GO) layers to form GO-BAC-HEP (modified graphite oxide). Nanocomposite films were characterized by XRD, SEM, TEM, ATR-FTIR and TGA. The modified graphite oxide was observed to be homogeneously dispersed throughout the PDMS matrix. The effect of modified graphite oxide on the mechanical properties of the nanocomposite film was investigated. When the modified graphite oxide content was lower than 0.2 wt%, the nanocomposites showed excellent mechanical properties. Furthermore, nanocomposite films become delivery systems that release heparin slowly to make the nanocomposite films blood compatible. The in vitro studies included hemocompatibility testing for effects on platelet adhesion, platelet activation, plasma recalcification profiles, and hemolysis. Results from these studies showed that the anticoagulation properties of PDMS/GO-BCA-HEP nanocomposite films were greatly superior to those for no treated PDMS. Cell culture assay indicated that PDMS/GO-BCA-HEP nanocomposite films showed enhanced cell adhesion.

High-level vancomycin resistant Enterococcus faecium related to humans and pigs found in dust from pig breeding facilities.

PubMed

Braga, Teresa M; Pomba, Constança; Lopes, M Fátima Silva

2013-01-25

Environmental dust from animal breeding facilities was never screened for the presence of enterococci, nor of vancomycin-resistant enterococci (VRE), despite the possibility of being a vehicle of transmission of strains and antibiotic resistance genes between food-producing animals and man. Bio-security measures in pig facilities include disinfection with biocides to avoid the dissemination of opportunistic pathogenic bacteria, namely enterococci and in particular VRE. We thus undertook collection of enterococci and VRE in a representative number of breeding pig facilities in Portugal (n=171) and analyzed their susceptibility to benzalkonium chloride (BC) and chlorhexidine (CHX). A prevalence of 15% of VRE was found, with 6% high-level resistance found, and MIC values for CHX and BC were similar to those commonly found among enterococcal isolates from related environments, 8 μg/ml and 4 μg/ml, respectively. Among the isolated high-level vancomycin resistant Enterococcus faecium carrying the vanA genotype, we found multilocus sequence types closely related to pig and human isolates from European countries and Brazil. These results strongly advise constant surveillance of this environment and its inclusion in future epidemiologic studies on VRE. Copyright © 2012 Elsevier B.V. All rights reserved.

In vitro evaluation of the disinfection efficacy on Eimeria tenella unsporulated oocysts isolated from broilers.

PubMed

Guimarães, José S; Bogado, Alexey L Gomel; da Cunha, Thiago Cezar B; Garcia, João Luis

2007-01-01

The objective of this study was to evaluate in vitro the action of eight chemical principles by disinfection efficacy (DE) of Eimeria tenella oocysts. Disinfection efficacy was evaluated by either destruction or sporulation inhibition of the oocysts. Eight treatments were performed: T1 (Glutaraldehyde 42.5 g + Benzalkonium Chloride 7.5 g); T2 (Benzalkonium chloride + quaternary ammonium salt); T3 (formol 37% + Sodium Dodecylbenzene Sulfonate 12%); T4 (sodium hypochlorite 2%); T5 (Orthodichlorobenzene 60% + Xylene 30%); T6 (Polyoctyl polyamino ethyl glycine + Polyoxyethylene alkylphenol ether + Sodium Chloride); T7 (Chloramine T) and finally T8 (free iodine 2.25% + Phosphoric acid 15 g). The control test was carried out with distilled water (T9). The best DE were observed, respectively, in T3 (79.49%), T5 (75.60%) and T4 (65.56%) treatments.

[Benzalkonium chloride: unacceptable to sterilize or disinfect medical or dental instruments].

PubMed

Acosta-Gío, E; Herrero-Farías, A; Mata-Portuguez, V H

2001-01-01

To compare the sporicidal activity of benzalkonium chloride (BKC) with that of glutaraldehyde. A comparative study was conducted at the microbiology laboratory of Facultad de Odontología, Universidad Nacional Autónoma de México. Bacillus subtilis ATCC 9372 spores were exposed to these germicides (1 spore x mL) on a 0.22 mm filter. After completing the contact time the spores were washed and the filters were incubated on nutrient agar for 72 h at 37 degrees C. BKC did not eliminate B. subtilis spores at the concentration used, not even after increasing contact time to 15 h (900-fold the recommended time). Two percent glutaraldehyde destroyed spores only after 10 h of contact. Urea and sodium chloride showed no sporicidal activity. The results confirm that BKC lacks sporicidal activity and confirm that this quaternary ammonium compound is not able to "sterilize" or "disinfect" medical and dental instruments.

Polyquaternium-1-Preserved Travoprost 0.003% or Benzalkonium Chloride-Preserved Travoprost 0.004% for Glaucoma and Ocular Hypertension.

PubMed

Peace, James H; Ahlberg, Peter; Wagner, Mathias; Lim, John M; Wirta, David; Branch, James D

2015-08-01

To demonstrate equivalence of polyquaternium-1-preserved travoprost 0.003% with benzalkonium chloride-preserved travoprost 0.004% in patients with open-angle glaucoma or ocular hypertension. Double-masked, randomized, 2-treatment, equivalence clinical trial. setting: Multicenter clinical trial conducted in 60 centers in the United States and Europe. Adult patients with open-angle glaucoma or ocular hypertension. One eye per patient was analyzed. Patients were randomized 1:1 to receive polyquaternium-1-preserved travoprost 0.003% (n = 442) or benzalkonium chloride-preserved travoprost 0.004% (n = 422) once daily for 3 months. Mean intraocular pressure (IOP) was assessed at 8 AM, 10 AM, and 4 PM at week 2, week 6, and month 3. Supportive outcomes were mean and percent IOP change, percentage of patients achieving IOP <18 mm Hg or ≥30% IOP reduction, and adverse events. Mean IOP was similar between groups at all study visits (travoprost 0.003% range, 17.5-18.9 mm Hg; travoprost 0.004% range, 17.4-19.0 mm Hg). Mean change (least squares mean differences, -0.1 to 0.3 mm Hg; 95% confidence interval, -0.5 to 0.7 mm Hg) and percentage change (travoprost 0.003%, 28.4%-30.7%; travoprost 0.004%, 28.5%-31.0%) from baseline were comparable. The percentages of patients with IOP <18 mm Hg and ≥30% reduction of IOP were also similar. Hyperemia was the most frequent treatment-related adverse event with both formulations (travoprost 0.003%, 11.8%; travoprost 0.004%, 14.5%). In patients with open-angle glaucoma or ocular hypertension, polyquaternium-1-preserved travoprost 0.003% solution provided equivalent IOP-lowering efficacy to that of benzalkonium chloride-preserved travoprost 0.004%. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Combined treatments of enterocin AS-48 with biocides to improve the inactivation of methicillin-sensitive and methicillin-resistant Staphylococcus aureus planktonic and sessile cells.

PubMed

Caballero Gómez, Natacha; Abriouel, Hikmate; Grande, M José; Pérez Pulido, Rubén; Gálvez, Antonio

2013-05-15

Control of staphylococci during cleaning and disinfection is important to the food industry. Broad-spectrum bacteriocins with proved anti-staphylococcal activity, such as enterocin AS-48, could open new possibilities for disinfection in combination with biocides. In the present study, enterocin AS-48 was tested singly or in combination with biocides against a cocktail of six Staphylococcus aureus strains (including three methicillin-resistant strains) in planktonic state as well as in biofilms formed on polystyrene microtiter plates. Cells were challenged with enterocin, biocides or enterocin/biocide combinations. Inactivation of planktonic cells increased significantly (p<0.05) when enterocin AS-48 (25mg/l) was tested in combination with benzalkonium chloride (BC), cetrimide (CT) and hexadecylpyridinium chloride (HDP), and non-significantly in combination with didecyldimethylammonium bromide (AB), triclosan (TC), hexachlorophene (CF), polyhexamethylen guanidinium chloride (PHMG), chlorhexidine (CH) or P3-oxonia (OX). In the sessile state (24h biofilms), staphylococci required higher biocide concentrations in most cases, except for OX. Inactivation of sessile staphylococci increased remarkably when biocides were applied in combination with enterocin AS-48, especially when the bacteriocin was added at 50mg/l. During storage, the concentrations of sessile as well as planktonic cells in the treated samples decreased remarkably for BC, TC and PHMG, but OX failed to inhibit proliferation of the treated biofilms as well as growth of planktonic cells. The observed inhibitory effects during storage were potentiated when the biocides were combined with 50 mg/l enterocin AS-48. Results from this study suggest that selected combinations of enterocin AS-48 and biocides offer potential use against planktonic and sessile, methicillin-sensitive and methicillin-resistant S. aureus. Copyright © 2013 Elsevier B.V. All rights reserved.

Benzalkonium Chloride: A Bronchoconstricting Preservative in Continuous Albuterol Nebulizer Solutions.

PubMed

Prabhakaran, Sreekala; Abu-Hasan, Mutasim; Hendeles, Leslie

2017-05-01

For convenience, many pediatric hospitals are preparing solutions for continuous nebulized albuterol using the 0.5% 20-ml multidose albuterol dropper bottle. This product contains benzalkonium chloride (BAC) that, by itself, produces bronchospasm that is dose dependent and cumulative. The bronchoconstrictive effects of BAC are greater in patients with more severe airway obstruction and increased airway responsiveness. Use of BAC-containing albuterol during severe acute asthma exacerbations may antagonize the bronchodilator response to albuterol, prolong treatment, and increase the risk of albuterol-related systemic adverse effects. Such a deleterious effect of BAC is difficult to detect because some patients improve slowly or may even worsen during treatment. We recommend that only preservative-free albuterol products be used. © 2017 Pharmacotherapy Publications, Inc.

No reduction with ageing of the number of myenteric neurons in benzalkonium chloride treated rats.

PubMed

Garcia, S B; Demarzo, M M P; Vinhadeli, W S; Llorach-Velludo, M A; Zoteli, J; Herrero, C F P S; Zucoloto, S

2002-10-04

The number of myenteric neurons may be reduced by topical serosal application of benzalkonium chloride (BAC). We studied the effects of ageing in the population of neurons that survive after the application of BAC. Ten treated and ten control animals were killed at intervals of 2, 6, 12 and 18 months after the surgery. We performed myenteric neurons counting in serially cut histological preparations of the descending colon. The control animals revealed a continuous loss of myenteric neurons number with increasing of age. Interestingly, contrary to control animals, the BAC-treated rats presented no neuron loss with ageing at any experimental time. The reasons for their survival with ageing could be related to a neuroplasticity phenomenon.

[Jejunal myenteric denervation induced by benzalkonium chloride].

PubMed

Ramalho, F S; Santos, G C; Ramalho, L N; Kajiwara, J K; Zucoloto, S

1994-01-01

The effects of benzalkonium chloride (BAC) on the number of myenteric neurons, muscle thickness and external perimeter after acute (until 10 days after BAC application) and chronic (30 and 60 days after BAC application) denervation of the proximal jejunum were determined in rats. There was a significant reduction in the number of myenteric neurons of all segments treated with BAC. The extent of denervation varied along the time, and it was reduced in the denervated segments of the chronic group in comparison with the acute group. This may be due to the neuroplasticity phenomenon appearing during the chronic phase. Myenteric denervation increased the thickness of the propria muscle layer, especially in the longitudinal muscle layer, suggesting a higher sensitivity of this layer to myenteric denervation.

Benzalkonium runoff from roofs treated with biocide products - In situ pilot-scale study.

PubMed

Gromaire, M C; Van de Voorde, A; Lorgeoux, C; Chebbo, G

2015-09-15

Roof maintenance practices often involve the application of biocide products to fight against moss, lichens and algae. The main component of these products is benzalkonium chloride, a mixture of alkyl benzyl dimethyl ammonium chlorides with mainly C12 and C14 alkyl chain lengths, which is toxic for the aquatic environment. This paper describes, on the basis of an in-situ pilot scale study, the evolution of roof runoff contamination over a one year period following the biocide treatment of roof frames. Results show a major contamination of roof runoff immediately after treatment (from 5 to 30 mg/L), followed by an exponential decrease. 175-375 mm of cumulated rainfall is needed before the runoff concentrations become less than EC50 values for fish (280 μg/l). The residual concentration in the runoff water remains above 4 μg/L even after 640 mm of rainfall. The level of benzalkonium ions leaching depends on the roofing material, with lower concentrations and total mass leached from ceramic tiles than from concrete tiles, and on the state of the tile (new or worn out). Mass balance calculations indicate that a large part of the mass of benzalkonium compounds applied to the tiles is lost, probably due to biodegradation processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sorption and leaching of benzalkonium chlorides in agricultural soils.

PubMed

Khan, Adnan Hossain; Macfie, Sheila M; Ray, Madhumita B

2017-07-01

The adsorption and leaching characteristics of two commonly used benzalkonium chlorides (BACs), benzyl dimethyl dodecyl ammonium chloride (BDDA) and benzyl dimethyl tetradecyl ammonium chloride (BDTA) using three agricultural soils with varied proportions of silt, sand, clay, and organic matter were determined. BACs are cationic surfactants used in large quantities for sanitary and personal care products and are abundant in environmental samples. Adsorption isotherm data (aqueous concentration in the range of 25-150 mg L -1 ) fitted the Langmuir model better than the Freundlich model. BDTA with a longer alkyl chain adsorbed more to soil compared to BDDA, and the soil with the highest percentage of clay adsorbed the most. Column tests conducted using soils amended with lime stabilised biosolids and artificial rain water at a flow rate of 0.2 mL min -1 indicate very low leaching of BACs. Less than 1% of the available BDDA leached through sandy loam soil column with a depth of 9 cm. Therefore, the possibility of BACs to become bioavailable through leaching is very low at environmentally relevant concentrations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison between the resistance of benzalkonium chloride-adapted and -nonadapted biofilms of Listeria monocyogenes to modified atmosphere packaging and nisin once transferred to mussels.

PubMed

Saá Ibusquiza, P; Herrera, J J R; Cabo, M L

2011-07-01

Benzalkonium chloride-adapted and -nonadapted Listeria monocytogenes biofilm cells were transferred by contact to cooked or live mussels and packed in rich CO(2) and O(2), respectively. The viabilities of transferred cells during storage of these packed samples at 2.5 °C were compared. In addition, in cooked mussels the combined effect of CO(2) and nisin against the survival of L. monocytogenes was also studied by using a first-order factorial design. The results obtained demonstrated that biofilms formed by benzalkonium chloride-adapted L. monocytogenes cells could be more resistant to the application of modified atmospheres rich in CO(2) and nisin once they have been transferred to cooked mussels by contact (simulating cross-contamination). This implies an increase in the risk associated with the presence of these cells in food processing plants. Significant empirical equations obtained after 7, 11, and 20 days showed an inhibitory effect of CO(2) and nisin against L. monocytogenes. However, a significant positive interaction between both variables highlights an incompatibility between CO(2) and nisin at high concentrations. Results also demonstrated that L. monocytogenes could persist after cross-contamination during the processing of live mussels, so L. monocytogenes is of concern as a contaminant in live mussels packaged in high-O(2) atmospheres. Copyright ©, International Association for Food Protection

Comparative Transcriptomic and Phenotypic Analysis of the Responses of Bacillus cereus to Various Disinfectant Treatments▿ †

PubMed Central

Ceragioli, Mara; Mols, Maarten; Moezelaar, Roy; Ghelardi, Emilia; Senesi, Sonia; Abee, Tjakko

2010-01-01

Antimicrobial chemicals are widely applied to clean and disinfect food-contacting surfaces. However, the cellular response of bacteria to various disinfectants is unclear. In this study, the physiological and genome-wide transcriptional responses of Bacillus cereus ATCC 14579 exposed to four different disinfectants (benzalkonium chloride, sodium hypochlorite, hydrogen peroxide, and peracetic acid) were analyzed. For each disinfectant, concentrations leading to the attenuation of growth, growth arrest, and cell death were determined. The transcriptome analysis revealed that B. cereus, upon exposure to the selected concentrations of disinfectants, induced common and specific responses. Notably, the common response included genes involved in the general and oxidative stress responses. Exposure to benzalkonium chloride, a disinfectant known to induce membrane damage, specifically induced genes involved in fatty acid metabolism. Membrane damage induced by benzalkonium chloride was confirmed by fluorescence microscopy, and fatty acid analysis revealed modulation of the fatty acid composition of the cell membrane. Exposure to sodium hypochlorite induced genes involved in metabolism of sulfur and sulfur-containing amino acids, which correlated with the excessive oxidation of sulfhydryl groups observed in sodium hypochlorite-stressed cells. Exposures to hydrogen peroxide and peracetic acid induced highly similar responses, including the upregulation of genes involved in DNA damage repair and SOS response. Notably, hydrogen peroxide- and peracetic acid-treated cells exhibited high mutation rates correlating with the induced SOS response. PMID:20348290

Development and Testing of a Colorimetric 96 Well Plate Assay for the Determination of HD Hydrolysis Rate in Various Formulations

DTIC Science & Technology

2005-01-01

Cold Foam 1% ethylene glycol 1% benzalkonium chloride 1% polyvinylpolypyrrolidone 1% Brij 58 1% Benzyldimethyl tetradecyl ammonium chloride dihydrate...described in this report was authorized by the Defense Threat Reduction Agency. This work was started in December 2003 and completed in March 2004. The...LITERA TURE CITED ..................................................................................... 15 5 FIGURES 1. Rates of Chloride Release in

Antibiotic Agents

MedlinePlus

... residue-producing ). Common examples of this group are triclosan, triclocarban, and benzalkonium chloride. See the Table of ... soaps from 10 states in the US contained triclosan and approximately 30% of bar soaps contained triclocarban. ...

Randomized Controlled Trial of Antiseptic Hand Hygiene Methods in an Outpatient Surgery Clinic.

PubMed

Therattil, Paul J; Yueh, Janet H; Kordahi, Anthony M; Cherla, Deepa V; Lee, Edward S; Granick, Mark S

2015-12-01

Outpatient wound care plays an integral part in any plastic surgery practice. However, compliance with hand hygiene measures has shown to be low, due to skin irritation and lack of time. The objective of this trial was to determine whether single-use, long-acting antiseptics can be as effective as standard multiple-use hand hygiene methods in an outpatient surgical setting. A prospective, randomized controlled trial was performed in the authors' outpatient plastic surgery clinic at Rutgers New Jersey Medical School, Newark, NJ to compare the efficacy of an ethyl alcohol-based sanitizer (Avagard D Instant Hand Aniseptic, 3M Health Care, St. Paul, MN), a benzalkonium chloride-based sanitizer (Soft & Shield, Bioderm Technologies, Inc, Trenton, NJ, distributed by NAPP Technologies, Hackensack, NJ ), and soap and- water handwashing. Subjects included clinic personnel, who were followed throughout the course of a 3-hour clinic session with hourly hand bacterial counts taken. During the course of the trial, 95 subjects completed the clinic session utilizing 1 of the hand hygiene methods (36 ethyl alcohol-based sanitizer, 38 benzalkonium chloride-based sanitizer, and 21 soap-and-water handwashing). There was no difference between hand bacterial counts using the different methods at 4 hourly time points (P greater than 0.05). Hand bacterial counts increased significantly over the 3-hour clinic session with the ethyl alcohol-based sanitizer (9.24 to 21.90 CFU, P less than 0.05), benzalkonium chloride-based sanitizer (6.69 to 21.59 CFU, P less than 0.05), and soap-and-water handwashing (8.43 to 22.75 CFU, P less than 0.05). There does not appear to be any difference in efficacy between single-use, long-acting sanitizer, and standard multiple-use hand hygiene methods. Hand bacterial counts increased significantly over the course of the 3-hour clinic session regardless of the hand hygiene measure used. Hand condition of subjects was improved with the ethyl alcohol-based sanitizer and the benzalkonium chloride-based sanitizer compared with soap-and-water handwashing.

Effects of Formulation on Microbicide Potency and Mitigation of the Development of Bacterial Insusceptibility

PubMed Central

Cowley, Nicola L.; Forbes, Sarah; Amézquita, Alejandro; McClure, Peter; Humphreys, Gavin J.

2015-01-01

Risk assessments of the potential for microbicides to select for reduced bacterial susceptibility have been based largely on data generated through the exposure of bacteria to microbicides in aqueous solution. Since microbicides are normally formulated with multiple excipients, we have investigated the effect of formulation on antimicrobial activity and the induction of bacterial insusceptibility. We tested 8 species of bacteria (7 genera) before and after repeated exposure (14 passages), using a previously validated gradient plating system, for their susceptibilities to the microbicides benzalkonium chloride, benzisothiozolinone, chlorhexidine, didecyldimethyl ammonium chloride, DMDM-hydantoin, polyhexamethylene biguanide, thymol, and triclosan in aqueous solution (nonformulated) and in formulation with excipients often deployed in consumer products. Susceptibilities were also assessed following an additional 14 passages without microbicide to determine the stability of any susceptibility changes. MICs and minimum bactericidal concentrations (MBC) were on average 11-fold lower for formulated microbicides than for nonformulated microbicides. After exposure to the antimicrobial compounds, of 72 combinations of microbicide and bacterium there were 19 ≥4-fold (mean, 8-fold) increases in MIC for nonformulated and 8 ≥4-fold (mean, 2-fold) increases in MIC for formulated microbicides. Furthermore, there were 20 ≥4-fold increases in MBC (mean, 8-fold) for nonformulated and 10 ≥4-fold (mean, 2-fold) increases in MBC for formulated microbicides. Susceptibility decreases fully or partially reverted back to preexposure values for 49% of MICs and 72% of MBCs after further passage. In summary, formulated microbicides exhibited greater antibacterial potency than unformulated actives and susceptibility decreases after repeated exposure were lower in frequency and extent. PMID:26253662

Interaction of antimicrobial preservatives with blow-fill-seal packs: correlating sorption with solubility parameters.

PubMed

Amin, Aeshna; Dare, Manish; Sangamwar, Abhay; Bansal, Arvind Kumar

2012-01-01

The aim of this work was to study the interaction of four commonly used ophthalmic antimicrobial preservatives [benzyl alcohol (BA), chlorbutol (CBL), benzalkonium chloride (BKC), and chlorhexidine gluconate (CG)] with Blow-Fill-Seal (BFS) packs. Effect of packaging material [low-density polyethylene (LDPE), polypropylene (PP)], humidity (25% RH, 75% RH) and concentration (0.5, 1.0, 2.0 mM BA/CBL in LDPE) was studied. BKC and CG gave negligible loss (<4%) in BFS packs over a period of 3 months. BA and CBL, however, gave marked losses in LDPE (ca. 70-90%) and PP (ca. 7-25%) packs. Humidity did not have any effect on the sorption loss of any preservative. Loss of BA switched from Case II to anomalous behavior with increasing initial concentration. A two-stage sorption behavior was inherent at all concentrations. Loss of CBL followed anomalous behavior with biphasic kinetics of loss. It was concluded that all the four preservatives were appropriate for use in PP BFS packs. However, only BKC and CG were amenable to be used in LDPE BFS packs. Lastly, an empirical expression consisting of the "solubility parameter distance" and "molar volume" of preservatives was developed to correlate the preservative loss in LDPE with the physicochemical properties of the preservatives.

Benzalkonium Chloride and Glaucoma

PubMed Central

Kaufman, Paul L.; Kiland, Julie A.

2014-01-01

Abstract Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapoptosis, cytoskeleton changes, and immunoinflammatory reactions. These same effects have been reported in cultured human TM cells exposed to concentrations of BAK found in common glaucoma drugs and in the TM of primary open-angle glaucoma donor eyes. It is possible that a relationship exists between chronic exposure to BAK and glaucoma. The hypothesis that BAK causes/worsens glaucoma is being tested experimentally in an animal model that closely reflects human physiology. PMID:24205938

Ocular Surface Disease in Glaucoma: Effect of Polypharmacy and Preservatives.

PubMed

Ramli, Norlina; Supramaniam, Gowri; Samsudin, Amir; Juana, Azida; Zahari, Mimiwati; Choo, May May

2015-09-01

To evaluate the prevalence of ocular surface disease (OSD) in glaucoma and nonglaucoma subjects using different clinical tests and to determine the effect of number of antiglaucoma medications and preservatives on OSD. This is a cross-sectional, case-comparison study at the Eye Clinic of the University of Malaya Medical Centre, Malaysia, between June 2012 and January 2013. Glaucoma subjects (n = 105) using topical antiglaucoma medications were compared with control subjects (n = 102) who were not on any topical medications. The presence of OSD was assessed using the tear film breakup time (TBUT) test, corneal staining, Schirmer test, and Ocular Surface Disease Index (OSDI) questionnaire grading. The prevalence of OSD varied from 37 to 91% in the glaucoma group, depending on the type of clinical test. More subjects in the glaucoma group had corneal staining (63% vs. 36%, p = 0.004), abnormal Schirmer tests (39% vs. 25%, p = 0.049), and moderate OSDI symptoms (17% vs. 7%, p = 0.028). The percentage with abnormal TBUT increased with higher numbers of topical medications and was high with both benzalkonium chloride-containing and preservative-free eye drops (90% and 94%, respectively, both p < 0.001). Benzalkonium chloride was associated with a nearly three times higher odds ratio of showing abnormal OSDI. Ocular surface disease is common in those using topical antiglaucoma medications. Abnormal TBUT is associated with increasing number of eye drops and benzalkonium chloride-containing eye drops, although this also occurs with the use of preservative-free eye drops.

XTT assay for evaluating the effect of alcohols, hydrogen peroxide and benzalkonium chloride on biofilm formation of Staphylococcus epidermidis.

PubMed

Chaieb, Kamel; Zmantar, Tarek; Souiden, Yosra; Mahdouani, Kacem; Bakhrouf, Amina

2011-01-01

To analyze the degree of biofilm formation on three ica-positives Staphylococcus epidermidis as a function of biocides, the medium was supplemented with increasing concentrations of isopropanol, ethanol, and methanol at 0, 1, 4, 6, 8, 10, 12 and 14% (v/v), hydrogen peroxide (0, 0.125, 0.25, 0.5, 1, 2, 3, 4 and 5% v/v) and benzalkonium chloride (0, 0.125, 0.25, 0.5, 1, 2, 3, 4 and 6 μg ml⁻¹). In biocide-free biofilms, the results showed that two strains (S. epidermidis CIP106510 and E24) were strongly biofilm positive displaying a high oxidative activity (1.254 and 0.855, respectively) in comparison with the non-adherent one (S22). In addition biofilm formation was induced with 1% alcohol (isopropanol and ethanol) supplementation. The three studied strains cultured in TSB supplemented with 2% methanol displayed a strong oxidative activity (P=0.008). Moreover wells with 0.125% hydrogen peroxide enhanced increasing oxidative activity of S. epidermidis CIP106510 and S22. A significant induction of biofilm was noted after treatment with 1 μg ml⁻¹ of benzalkonium chloride. This study suggests that some biocides currently used in hospitals are ineffective against nosocomial pathogens growing in biofilms when used at weak concentration and fail to control this reservoir for hospital-acquired infection. Copyright © 2010 Elsevier Ltd. All rights reserved.

Multidose Preservative Free Eyedrops by Selective Removal of Benzalkonium Chloride from Ocular Formulations.

PubMed

Hsu, Kuan-Hui; Gupta, Karishma; Nayaka, Harish; Donthi, Aashrit; Kaul, Siddarth; Chauhan, Anuj

2017-12-01

About 70% of eye drops contain benzalkonium chloride (BAK) to maintain sterility. BAK is an effective preservative but it can cause irritation and toxicity. We propose to mitigate ocular toxicity without compromising sterility by incorporating a filter into an eye drop bottle to selectively remove BAK during the process of drop instillation. The filter is a packed bed of particles made from poly(2-hydroxyethyl methacrylate) (pHEMA), which is a common ophthalmic material. We showed that pHEMA particle prepared by using ethoxylated trimethylolpropane triacrylate as crosslinker can be incorporated into a modified eyedrop bottle tip to selectively remove the preservative as the formulation is squeezed out of the bottle. Hydraulic permeability of the plug is measured to determine the resistance to eye drop squeezing, and % removal of BAK and drugs are determined. The modified tip has a hydraulic permeability of about 2 Darcy, which allows eyedrops formulations to flow through without excessive resistance. The tip is designed such that the patients can create an eyedrop of solution of 1-10 cP viscosity in 4 s with a nominal pressure. During this short contact time, the packed particles removed nearly 100% of benzalkonium chloride (BAK) from a 15 mL, 0.012% BAK solution but have only minimal impact on the concentration of contained active components. Our novel design can eliminate the preservative induced toxicity from eye drops thereby impacting hundreds of millions of patients with chronic ophthalmic diseases like glaucoma and dry eyes.

Cyclopentolate Ophthalmic

MedlinePlus

... e.g., use sunglasses). Cyclopentolate may make your eyes sensitive to sunlight.you should know that ophthalmic cyclopentolate contains benzalkonium chloride, which can be absorbed by soft contact lenses. If you wear contact lenses, remove them before instilling ophthalmic cyclopentolate.

Bepotastine Ophthalmic

MedlinePlus

... that you think may be caused by contact lenses. Bepotastine eye drops contain benzalkonium chloride, which can be absorbed ... you are wearing contact lenses. Remove your contact lenses before you use bepotastine eye drops and do not replace them for at ...

Fundamental Studies on High Temperature Deformation, Recrystallization, and Grain Growth of Two-Phase Materials

DTIC Science & Technology

1990-09-26

50 ml. Glycerine R -etch 17 ml. Benzalkonium Chloride 35 ml. Ethanol Kroll - etch 2 ml. Hydrofluoric Acid ( 50 %) 4 ml. Nitric Acid Conc. 100 ml...The amount of work given ( 60 % reduction in area ) in this last step was found to be sufficient to recrystallize all of the alloys within 12 hours at...formed at the center of thedisc with the following solution: 10 gins. Zinc Chloride 5 gms. Aluminum Chloride 300 ml. Methanol 50 ml. N - Butanol A JEOL

The sensitivity to chlorhexidine and cetyl pyridinium chloride of staphylococci on the hands of dental students and theatre staff exposed to these disinfectants.

PubMed

Millns, B; Martin, M V; Field, E A

1994-02-01

The aim of this investigation was to study the possible emergence of resistant isolates of the genus Staphylococcus on the hands of dental personnel who use 'Hibiscrub' (chlorhexidine-detergent preparation) and cetyl pyridinium-coated gloves. Resistance was determined by a rate-of-kill technique. In four dental student groups (first, second, third and fourth years) no microorganisms survived 30 min exposure to cetyl pyridinium chloride (CPC) or to chlorhexidine diacetate (CDA). In a theatre staff group, no microorganisms survived 30 s exposure to CPC; and only one of 23 isolates survived 30 min exposure to CDA, but was killed after 60 min exposure. It is concluded that staphylococci resistant to either of these disinfectants do not present a problem in dental students or theatre staff.

Inhibitory effects of antiseptic mouthrinses on Streptococcus mutans, Streptococcus sanguinis and Lactobacillus acidophilus.

PubMed

Evans, A; Leishman, S J; Walsh, L J; Seow, W K

2015-06-01

Oral antiseptics are valuable in controlling oral infections caused by cariogenic bacteria. The aim of this study was to investigate the effects of mouthrinses and pure antiseptic compounds on Streptococcus mutans and non-mutans bacteria (Streptococcus sanguinis and Lactobacillus acidophilus). The agar diffusion assay was employed to determine bacterial growth inhibition. Commercial mouthrinses containing chlorhexidine gluconate (0.2%), cetylpyridinium chloride (0.05%) and sodium fluoride (0.05%) produced statistically similar growth inhibition of S. mutans, S. sanguinis and L. acidophilus (with zones of inhibition ranging from 7.56 ± 0.52 mm to 7.39 ± 0.53 mm, 17.44 ± 0.94 mm to 18.31 ± 0.62 mm and 8.61 ± 1.43 to 8.67 ± 1.43 mm respectively, p > 0.05). The chlorhexidine mouthwash produced the greatest mean growth inhibition of S. sanguinis and S. mutans compared to all other mouthrinses tested (p < 0.01). The minimum concentrations at which inhibition against S. mutans could be detected were chlorhexidine gluconate at 0.005% (wt/vol), cetylpyridinium chloride 0.01% (wt/ vol), povidone iodine 10% (wt/vol) and sodium hypochlorite 0.5% (vol/vol). Chlorhexidine (0.01%), cetylpyridinium chloride (0.01%), povidone iodine (10%) and sodium hypochlorite (0.5%) are effective at inhibiting the growth of S. mutans, S. sanguinis and L. acidophilus. © 2015 Australian Dental Association.

Efficacy of detergents and fresh produce disinfectants against microorganisms associated with mixed raw vegetables.

PubMed

Samadi, Nasrin; Abadian, Neda; Bakhtiari, Donya; Fazeli, Mohammad Reza; Jamalifar, Hossein

2009-07-01

Efficacy of commercial detergent and disinfectants to eliminate microorganisms associated with fresh vegetables eaten raw in Iran, including radish, parsley, basil, coriander (cilantro), Allium porrum (leek), and peppermint were studied. The raw vegetables were subjected to a triple wash treatment of washing in tap water for mud removal, washing in water containing a detergent (dishwashing liquid) or disinfectant individually, and rinsing in tap water. The population of total mesophilic microbes on the surface of untreated vegetables ranged from 10(5) to 10(6) CFU/g. Washing in tap water or treatment with detergent (333 ppm for 10 min) or benzalkonium chloride (92 ppm for 15 min) reduced the total microbial count, most probable number (MPN) of coliforms, MPN of fecal coliforms, and MPN of fecal streptococci by about 1.2 to 2.3 log. No significant differences in microbial populations were found on vegetables after decontamination with tap water, detergent, or benzalkonium chloride (P > 0.05). Treatments with peracetic acid (100 ppm for 15 min) and hydrogen peroxide (133 ppm for 30 min) reduced the total mesophilic microbial counts by about 2.8 log. The microbial reductions with calcium hypochlorite (300 ppm for 15 min) and combined hydrogen peroxide and silver ion (133 ppm for 30 min) were significantly higher than those obtained after rinsing in tap water or after detergent or benzalkonium chloride wash (P < 0.05). Pretreatment with detergent slightly enhanced the efficacy of all decontamination treatments, but results were not significantly different from those obtained after individual application of disinfectants.

A rabbit dry eye model induced by topical medication of a preservative benzalkonium chloride.

PubMed

Xiong, Cuiju; Chen, Dong; Liu, Jingbo; Liu, Bingqian; Li, Naiyang; Zhou, Yang; Liang, Xuanwei; Ma, Ping; Ye, Chengtian; Ge, Jian; Wang, Zhichong

2008-05-01

To establish a rabbit dry eye model with topical medication of the ocular preparation preservative benzalkonium chloride (BAC). Sixteen white rabbits were used. One eye of each rabbit was chosen randomly for topical administration of 0.1% BAC twice daily for 14 days. The other untreated eyes served as controls. Schirmer test, fluorescein, and rose bengal staining were performed before and after BAC treatment on days 3, 5, 7, and 14. Conjunctiva impression cytology specimens were collected on days 0, 7, and 14. The rabbits were killed after day 14. Immunofluorescence staining was performed to detect mucin-5 subtype AC (MUC5AC) on conjunctival cryosections. Cornea and conjunctiva structures were evaluated by light and electron microscopy. Compared with untreated controls, BAC-treated eyes showed significant decreases in Schirmer scores (P = 0.01) and increases in fluorescein scores (P < 0.001) on days 5, 7, and 14. A significant increase in rose bengal scores was noticed as early as day 3 (P = 0.001). Decreases in goblet cell density occurred on days 7 and 14 (P = 0.001). Decreased MUC5AC and histopathologic and ultrastructural disorders of the cornea and conjunctiva were also observed in the BAC group. These findings demonstrated that an ophthalmic preservative, benzalkonium chloride, induced a dry eye syndrome in rabbits with damage to the cornea and conjunctiva, decreased aqueous tear basal secretion, goblet cell loss, and MUC5AC deficiency. This rabbit model was consistent with human dry eye syndrome in both aqueous tear and mucin deficiency and may be appropriate for studying dry eye syndrome.

Dexamethasone Ophthalmic

MedlinePlus

... stopping to breast-feed if you use dexamethasone eye drops.tell your doctor if you wear soft contact lenses. If the brand of dexamethasone you are using contains benzalkonium chloride, wait at least 15 minutes after using the medicine to put in soft contact lenses.

Cold Water Cleaning and Sanitizing of Kitchenware in the Field

DTIC Science & Technology

1989-12-01

product would not be expected Product may result in irritat tact dermatitis have been rep benzalkonium chloride compoun mists or vapors may result in...CONSERVATION COLD WATER 19. ABSTRACT {Continue on reverse if necessary and identify by block number) In emergency situations in the field, where reduction ...MATERIAL: <CAS#) ! % Bv Wt. I TLV I PEL n-Alkyl Dimethyl Benzyl Ammonium Chloride (68424-85-1) Octyl decy I dimethyl

Comparative susceptibility of Salmonella Typhimurium biofilms of different ages to disinfectants.

PubMed

Wong, Hui San; Townsend, Kirsty M; Fenwick, Stan G; Maker, Garth; Trengove, Robert D; O'Handley, Ryan M

2010-10-01

There is a general consensus that with increasing age a biofilm shows increased resistance to antimicrobials. In this study the susceptibility of 3-, 5- and 7-day-old Salmonella enterica serovar Typhimurium biofilms to disinfectants was evaluated. It was hypothesized that 7-day-old biofilms would be more resistant to disinfectants compared to 3- and 5-day-old biofilms. Biofilms were formed using the MBEC™ system and treated with six chemical disinfectants for 1 and 5 min. Four disinfectants at the highest concentration available showed 100% reduction in viable cells from all ages of biofilms after exposure for 5 min, and ethanol at 70% v/v was the least effective against biofilms, followed by chlorhexidine gluconate (CG). At the recommended user concentrations, only sodium hypochlorite showed 100% reduction in viable cells from all ages of biofilms. Benzalkonium chloride and CG were the least effective against biofilms, followed by quaternary ammonium compound which only showed 100% reduction in viable cells from 5-day-old biofilms. Overall, the results from this study do not display enhanced resistance in 7-day-old biofilms compared to 3- and 5-day-old biofilms. It is concluded that under the conditions of this study, the age of biofilm did not contribute to resistance towards disinfectants. Rather, the concentration of disinfectant and an increased contact time were both shown to play a role in successful sanitization.

Restoring conjunctival tolerance by topical nuclear factor-κB inhibitors reduces preservative-facilitated allergic conjunctivitis in mice.

PubMed

Guzmán, Mauricio; Sabbione, Florencia; Gabelloni, María Laura; Vanzulli, Silvia; Trevani, Analía Silvina; Giordano, Mirta Nilda; Galletti, Jeremías Gastón

2014-09-04

To evaluate the role of nuclear factor-κB (NF-κB) activation in eye drop preservative toxicity and the effect of topical NF-κB inhibitors on preservative-facilitated allergic conjunctivitis. Balb/c mice were instilled ovalbumin (OVA) combined with benzalkonium chloride (BAK) and/or NF-κB inhibitors in both eyes. After immunization, T-cell responses and antigen-induced ocular inflammation were evaluated. Nuclear factor-κB activation and associated inflammatory changes also were assessed in murine eyes and in an epithelial cell line after BAK exposure. Benzalkonium chloride promoted allergic inflammation and leukocyte infiltration of the conjunctiva. Topical NF-κB inhibitors blocked the disruptive effect of BAK on conjunctival immunological tolerance and ameliorated subsequent ocular allergic reactions. In line with these findings, BAK induced NF-κB activation and the secretion of IL-6 and granulocyte-monocyte colony-stimulating factor in an epithelial cell line and in the conjunctiva of instilled mice. In addition, BAK favored major histocompatibility complex (MHC) II expression in cultured epithelial cells in an NF-κB-dependent fashion after interaction with T cells. Benzalkonium chloride triggers conjunctival epithelial NF-κB activation, which seems to mediate some of its immune side effects, such as proinflammatory cytokine release and increased MHC II expression. Breakdown of conjunctival tolerance by BAK favors allergic inflammation, and this effect can be prevented in mice by topical NF-κB inhibitors. These results suggest a new pharmacological target for preservative toxicity and highlight the importance of conjunctival tolerance in ocular surface homeostasis. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Alcaftadine Ophthalmic

MedlinePlus

... if your eye(s) is/are red. If your eyes are not red and you wear contact lenses, you should know that alcaftadine solution contains benzalkonium chloride, which can be absorbed by soft contact lenses. Remove your contact lenses before instilling alcaftadine and put them back in 10 minutes later.

Olopatadine Ophthalmic

MedlinePlus

... if your eye(s) is/are red. If your eye is not red and you wear contact lenses, you should know that olopatadine solution contains benzalkonium chloride, which can be absorbed by soft contact lenses. Remove your contact lenses before applying olopatadine and put them back in 10 minutes later.

Azelastine Ophthalmic

MedlinePlus

... if your eye(s) is/are red. If your eye is not red and you wear contact lenses, you should know that azelastine solution contains benzalkonium chloride, which can be absorbed by soft contact lenses. Remove your contact lenses before instilling azelastine and put them back in 10 minutes later.

Ketotifen Ophthalmic

MedlinePlus

... if your eye(s) is/are red. If your eyes are not red and you wear contact lenses, you should know that ketotifen solution contains benzalkonium chloride, which can be absorbed by soft contact lenses. Remove your contact lenses before instilling ketotifen and put them back in 10 minutes later.

Removal of Listeria monocytogenes dual-species biofilms using combined enzyme-benzalkonium chloride treatments.

PubMed

Rodríguez-López, Pedro; Carballo-Justo, Alba; Draper, Lorraine A; Cabo, Marta L

2017-01-01

The effects of pronase (PRN), cellulase (CEL) or DNaseI alone or combined with benzalkonium chloride (BAC) against Listeria monocytogenes-carrying biofilms were assayed. The best removal activity against L. monocytogenes-Escherichia coli biofilms was obtained using DNaseI followed by PRN and CEL. Subsequently, a modified logistic model was used to quantify the combined effects of PRN or DNaseI with BAC. A better BAC performance after PRN compared to DNaseI eradicating L. monocytogenes was observed. In E. coli the effects were the opposite. Finally, effects of DNaseI and DNaseI-BAC treatments were compared against two different L. monocytogenes-carrying biofilms. DNaseI-BAC was more effective against L. monocytogenes when co-cultured with E. coli. Nonetheless, comparing the removal effects after BAC addition, these were higher in mixed-biofilms with Pseudomonas fluorescens. However, a high number of released viable cells was observed after combined treatments. These results open new perspectives of enzymes as an anti-biofilm strategy for environmental pathogen control.

Quantifying the combined effects of pronase and benzalkonium chloride in removing late-stage Listeria monocytogenes-Escherichia coli dual-species biofilms.

PubMed

Rodríguez-López, Pedro; Puga, Carmen H; Orgaz, Belén; Cabo, Marta L

2017-09-01

This work presents the assessment of the effectivity of a pronase (PRN)-benzalkonium chloride (BAC) sequential treatment in removing Listeria monocytogenes-Escherichia coli dual-species biofilms grown on stainless steel (SS) using fluorescence microscopy and plate count assays. The effects of PRN-BAC on the occupied area (OA) by undamaged cells in 168 h dual-species samples were determined using a first-order factorial design. Empirical equations significantly (r 2 = 0.927) described a negative individual effect of BAC and a negative interactive effect of PRN-BAC achieving OA reductions up to 46%. After treatment, high numbers of remaining attached and released viable and cultivable E. coli cells were detected in PRN-BAC combinations when low BAC concentrations were used. Therefore, at appropriate BAC doses, in addition to biofilm removal, sequential application of PRN and BAC represents an appealing strategy for pathogen control on SS surfaces while hindering the dispersion of live cells into the environment.

A hybridization approach to efficient TiO2 photodegradation of aqueous benzalkonium chloride.

PubMed

Suchithra, Padmajan Sasikala; Carleer, Robert; Ananthakumar, Solaippan; Yperman, Jan

2015-08-15

TiO2 get positively charged upon UV-irradiation and repel the cationic pollutants away from the surface. Hybridization of AC onto TiO2 (ACT) tends catalyst surface negatively charged besides providing highly favorable adsorptions sites for cationic pollutants. The photodegradation of benzalkonium chloride (BKC), a quaternary ammonium surfactant and a pharmaceutical, is investigated with ACT. The surface charge of the catalyst in surfactant and non-surfactant aqueous dispersion under UV-irradiation is investigated and explained. The anomalous increase in COD values at the beginning of BKC-photodegradation is explained. The intermediate products formed are identified in both solution and solid phase. Trace amount of dodecane remained adsorbed on the catalyst surface after 1h UV-irradiation, but complete mineralization of BKC is achieved with 2h UV-irradiation. We propose that BKC photodegradation starts by central fission of benzyl CN bond followed by dealkylation, and demethylation steps. Copyright © 2015 Elsevier B.V. All rights reserved.

Topical timolol with and without benzalkonium chloride: epithelial permeability and autofluorescence of the cornea in glaucoma.

PubMed

de Jong, C; Stolwijk, T; Kuppens, E; de Keizer, R; van Best, J

1994-04-01

Epithelial permeability and autofluorescence of the cornea were determined by fluorophotometry in 21 patients with open-angle glaucoma or ocular hypertension using timolol medication with the preservative benzalkonium chloride (BAC) and 2 weeks after changing to timolol medication without BAC. The investigation was performed to determine whether removal of BAC would reduce toxic effects on the cornea and complaints of sensations of burning or dry eye. Corneal epithelial permeability decreased significantly after changing medication (mean decrease per patient 27%, P = 0.025). Corneal autofluorescence increased significantly after changing medication suggesting an alteration in corneal metabolism (mean increase per patient 6%, P = 0.003). Timolol without BAC was found to be as effective as timolol with BAC in reducing intraocular pressure (P = 0.4). Removal of BAC from timolol resulted in an improvement of corneal epithelial barrier function and in a reduction of complaints. The improvement was found to be proportional to the duration of the preceding BAC-containing therapy.

Effect of temperature and benzalkonium chloride on nitrate reduction.

PubMed

Hajaya, Malek G; Tezel, Ulas; Pavlostathis, Spyros G

2011-04-01

The effect of temperature and benzalkonium chloride (BAC) on nitrate reduction was investigated in batch assays using a mixed nitrate reducing culture. Nitrate was transformed completely, mainly through denitrification, to dinitrogen at 5, 10, 15 and 22 °C. In the absence of BAC, reduction of individual nitrogen oxides had different susceptibility to temperature and transient nitrite accumulation was observed at low temperatures. When the effect of BAC was tested up to 100 mg/L from 5 to 22 °C, denitrification was inhibited at and above 50mg BAC/L with transient nitrite accumulation at all temperatures. The effect of BAC was described by a competitive inhibition model. Nitrite reduction was the denitrification step most susceptible to BAC, especially at low temperatures. BAC was not degraded during the batch incubation and was mostly biomass-adsorbed. Overall, this study shows that low temperatures exacerbate the BAC inhibitory effect, which in turn is controlled by adsorption to biomass. Copyright © 2011 Elsevier Ltd. All rights reserved.

[Optimization of benzalkonium chloride concentration in 0.0015% tafluprost ophthalmic solution from the points of ocular surface safety and preservative efficacy].

PubMed

Asada, Hiroyuki; Takaoka-Shichijo, Yuko; Nakamura, Masatsugu; Kimura, Akio

2010-06-01

Optimization of benzalkonium chloride (alkyl dimethylbenzylammonium chloride: BAK) concentration as preservative in 0.0015% tafluprost ophthalmic solution (Tapros 0.0015% ophthalmic solution), an anti-glaucoma medicine, was examined from the points of ocular surface safety and preservative efficacy. BAKC(12), which is dodecyl dimethylbenzylammonium chloride, and BAKmix, which is the mixture of dodecyl, tetradecyl and hexadecyl dimethylbenzylammonium chloride were used in this study. The effects of BAKC(12) concentrations and the BAK types, BAKC(12) and BAKmix, in tafluprost ophthalmic solution on ocular surface safety were evaluated using the in vitro SV 40-immobilized human corneal epithelium cell line (HCE-T). Following treatments of Tafluprost ophthalmic solutions with BAKC(12), its concentration dependency was observed on cell viability of HCE-T. The cell viability of HCE-T after treatment of these solutions with 0.001% to 0.003% BAKC(12) for 5 minutes were the same level as that after treatment of the solution without BAK. Tafluprost ophthalmic solution with 0.01% BAKC(12) was safer for the ocular surface than the same solution with 0.01% BAKmix. Preservatives-effectiveness tests of tafluprost ophthalmic solutions with various concentrations of BAKC(12) were performed according to the Japanese Pharmacopoeia (JP), and solutions with more than 0.0005% BAKC(12) conformed to JP criteria. It was concluded that 0.0005% to 0.003% of BAKC(12) in tafluprost ophthalmic solution was optimal, namely, well-balanced from the points of ocular surface safety and preservative efficacy.

Technical Note: Could benzalkonium chloride be a suitable alternative to mercuric chloride for preservation of seawater samples?

NASA Astrophysics Data System (ADS)

Gloël, J.; Robinson, C.; Tilstone, G. H.; Tarran, G.; Kaiser, J.

2015-08-01

Instrumental equipment unsuitable or unavailable for fieldwork as well as lack of ship space can necessitate the preservation of seawater samples prior to analysis in a shore-based laboratory. Mercuric chloride (HgCl2) is routinely used for such preservation, but its handling and subsequent disposal incur significant risks and expense. Benzalkonium chloride (BAC) has been used previously for freshwater samples. Here, we assess BAC as a less hazardous alternative microbial inhibitor for marine samples prior to the measurement of oxygen-to-argon (O2/Ar) ratios, as used for the determination of plankton net community production. BAC at a concentration of 50 mg dm-3 inhibited microbial activity for at least three days in seawater with chlorophyll a (Chl a) concentrations up to 1 mg m-3, possibly longer when Chl a concentrations were lower. BAC concentrations of 100 and 200 mg dm-3 were no more effective than 50 mg dm-3. With fewer risks to human health and the environment, and no requirement for expensive waste disposal, BAC could be a viable alternative to HgCl2 for short-term preservation of seawater samples, but is not a replacement for HgCl2 in the case of oxygen triple isotope analysis, which requires storage over weeks to months. In any event, further tests on a case-by-case basis should be undertaken if use of BAC was considered, since its inhibitory activity may depend on concentration and composition of the microbial community.

Comparison of the efficacy of preservative free ipratropium bromide and Atrovent nebuliser solution.

PubMed Central

Rafferty, P; Beasley, R; Holgate, S T

1988-01-01

The paradoxical bronchoconstriction observed with commercially available isotonic ipratropium bromide nebuliser solution (Atrovent) in patients with asthma results from an adverse reaction to the preservatives, benzalkonium chloride and ethylenediaminetetra-acetic acid (EDTA). The airway response to inhaled Atrovent and preservative free ipratropium bromide nebuliser solutions has been examined in a double blind study. On separate occasions 30 asthmatic subjects inhaled 2 ml of the solutions and airway calibre was measured in terms of FEV1 for 45 minutes. Atrovent nebuliser solution provoked a greater than 20% fall in FEV1 in five of the 30 subjects, whereas this did not occur after preservative free ipratropium bromide. Inhalation of the preservative free solution resulted in more rapid and greater overall bronchodilatation than Atrovent, with mean maximum increases in FEV1 of 29.2% and 18.5% respectively. It is concluded that the risk of paradoxical bronchoconstriction with ipratropium bromide is considerably reduced by removal of benzalkonium chloride and EDTA and that preservative free ipratropium bromide is a more potent bronchodilator than the currently available Atrovent solution. PMID:2971274

Embryotoxicity of benzalkonium chloride in vaginally treated rats.

PubMed

Buttar, H S

1985-12-01

The effects of the spermicide benzalkonium chloride (BKC) were studied on the conceptus of rat. Single doses (0, 25, 50, 100 or 200 mg kg-1) of aqueous solutions of BKC were administered intravaginally (1 ml kg-1) on gestational day 1. The vulval metallic clips, used to prevent leakage of the solution, were removed 24 h post-treatment. Fetuses were obtained and examined for malformations on day 21 of gestation. slight to copious amounts of vaginal discharge and vaginitis were noticed in rats treated with the two largest doses of BKC. A dose-related increase in resorptions and fetal death, reduction in litter size and weight were observed in BKC-treated dams. The conceptus loss seemed to occur both before and after implantation. BKC did not cause any discernible visceral malformations, although minor sternal defects occurred in fetuses exposed to 100 and 200 mg kg-1 of the spermicide. These results suggest that single vaginal application of BKC is embryo- and fetocidal in the rat at a dose about 143 times higher than that recommended for controlling conception in women.

Light-activated phenalen-1-one bactericides: efficacy, toxicity and mechanism compared with benzalkonium chloride.

PubMed

Muehler, Denise; Sommer, Kerstin; Wennige, Sara; Hiller, Karl-Anton; Cieplik, Fabian; Maisch, Tim; Späth, Andreas

2017-11-01

Five photoactive compounds with variable elongated alkyl-substituents in a phenalen-1-one structure were examined in view of structural similarity to the antimicrobial agent benzalkonium chloride (BAC). All phenalen-1-ones and BAC were evaluated for their antimicrobial properties against Staphylococcus aureus, methicillin-resistant S. aureus, Escherichia coli, Pseudomonas aeruginosa and for their eukaryotic toxicity against normal human epidermal keratinocyte (NHEK) cells to narrow down the BAC-like effect and the photodynamic effect depending on the chemical structure. All compounds were investigated for effective concentration ranges, where a bacterial reduction of 5 log 10 is achieved, while an NHEK survival of 80% is ensured. Effective concentration ranges were found for four out of five photoactive compounds, but not for BAC and the compound with BAC-like alkyl chain length. Chain length size and polar area of the respective head-groups of phenalen-1-one compounds or BAC showed an influence on the incorporation inside lipid membranes and thus, head-groups may have an impact on the toxicity of antimicrobials.

Effect of benzalkonium chloride on viability and energy metabolism in exponential- and stationary-growth-phase cells of Listeria monocytogenes.

PubMed

Luppens, S B; Abee, T; Oosterom, J

2001-04-01

The difference in killing exponential- and stationary-phase cells of Listeria monocytogenes by benzalkonium chloride (BAC) was investigated by plate counting and linked to relevant bioenergetic parameters. At a low concentration of BAC (8 mg liter(-1)), a similar reduction in viable cell numbers was observed for stationary-phase cells and exponential-phase cells (an approximately 0.22-log unit reduction), although their membrane potential and pH gradient were dissipated. However, at higher concentrations of BAC, exponential-phase cells were more susceptible than stationary-phase cells. At 25 mg liter(-1), the difference in survival on plates was more than 3 log units. For both types of cells, killing, i.e., more than 1-log unit reduction in survival on plates, coincided with complete inhibition of acidification and respiration and total depletion of ATP pools. Killing efficiency was not influenced by the presence of glucose, brain heart infusion medium, or oxygen. Our results suggest that growth phase is one of the major factors that determine the susceptibility of L. monocytogenes to BAC.

Prolonged exposure of mixed aerobic cultures to low temperature and benzalkonium chloride affect the rate and extent of nitrification.

PubMed

Yang, Jeongwoo; Tezel, Ulas; Li, Kexun; Pavlostathis, Spyros G

2015-03-01

The combined effect of benzalkonium chloride (BAC) and prolonged exposure to low temperature on nitrification was investigated. Ammonia oxidation at 22-24°C by an enriched nitrifying culture was inhibited at increasing BAC concentrations and ceased at 15 mg BAC/L. The non-competitive inhibition coefficient was 1.5±0.9 mg BAC/L. Nitrification tests were conducted without and with BAC at 5mg/L using an aerobic, mixed heterotrophic/nitrifying culture maintained at a temperature range of 24-10°C. Maintaining this culture at 10°C for over one month in the absence of BAC, resulted in slower nitrification kinetics compared to those measured when the culture was first exposed to 10°C. BAC was degraded by the heterotrophic population, but its degradation rate decreased significantly as the culture temperature decreased to 10°C. These results confirm the negative impact of quaternary ammonium compounds on the nitrification process, which is further exacerbated by prolonged, low temperature conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hazards of Improper Dispensary: Literature Review and Report of an Accidental Chloroform Injection.

PubMed

Verma, Prashant; Tordik, Patricia; Nosrat, Ali

2018-06-01

Several clear, transparent solutions are used in endodontics. Inappropriate dispensing methods can lead to accidental injection or accidental irrigation. These accidents can cause permanent tissue damage including damage to the bone, periodontium, nerves, and vasculature. This article reports on the consequences of an accidental chloroform injection. Nonsurgical retreatment of tooth #8 was planned as part of a restorative treatment plan in a 69-year-old woman. The dentist accidentally injected chloroform instead of local anesthesia because chloroform was loaded into the anesthetic syringe. The patient experienced severe pain and swelling and soft tissue necrosis and suffered permanent sensory and motor nerve damage. A review of the literature was performed on accidents caused by improper dispensary, namely accidental injections and accidental irrigations. The data were extracted and summarized. Sodium hypochlorite, chlorhexidine, formalin, formocresol, 1:1000 adrenaline, benzalkonium chloride, and lighter fuel were accidentally injected as an intraoral nerve block or as infiltration injections. Bone and soft tissue necrosis, tooth loss, and sensory nerve damage (anesthesia and paresthesia) were the most common consequences reported. Such disastrous events can be prevented by appropriate labeling and separate dispensing methods for each solution. There is a need for disseminating information on toxicity and biocompatibility of materials/solutions used in endodontics. The authors recommend training dental students and endodontic residents on immediate and long-term therapeutic management of patients when an accidental injection or accidental irrigation occurs. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effect of low concentrations of benzalkonium chloride on acanthamoebal survival and its potential impact on empirical therapy of infectious keratitis.

PubMed

Tu, Elmer Y; Shoff, Megan E; Gao, Weihua; Joslin, Charlotte E

2013-05-01

The significant antiacanthamoebal effect of benzalkonium chloride, at or below concentrations used for preservation of common ophthalmic preparations, should be understood both when choosing empiric antibiotic therapy for infectious keratitis and when assessing the persistent rise in Acanthamoeba cases in the United States since 2003. To characterize the antiacanthamoebal efficacy of low concentrations of benzalkonium chloride (BAK) for drug preservation and therapeutic effect against Acanthamoeba. Experimental study with a review of the literature. Laboratory. A concentration of 10(4) trophozoites of 3 well-characterized clinical strains of Acanthamoeba were exposed at 0.5, 2.0, 3.5, 5.0, and 6.5 hours to BAK (0.001%, 0.002%, and 0.003%), moxifloxacin hydrochloride (0.5%), and moxifloxacin (0.5%) + BAK (0.001% and 0.003%) with hydrogen peroxide (3%) and amoeba saline controls. Amoeba survival was calculated using the most probable number method recorded as log kill values. The relationship of BAK concentration and exposure time as well as the relative effect of BAK and moxifloxacin on acanthamoebal survival were analyzed. Amoebicidal activity of BAK is both time dependent and concentration dependent in pooled and strain-stratified analyses (P < .001). Moxifloxacin demonstrated no significant independent inhibitory effect or additive effect to BAK efficacy on acanthamoebal survival. The profound antiacanthamoebal effect of BAK, 0.003%, was similar to that of hydrogen peroxide for certain strains. Low concentrations of BAK, previously demonstrated to concentrate and persist in ocular surface epithelium, exhibit significant antiacanthamoebal activity in vitro at or below concentrations found in commercially available ophthalmic anti-infectives. The unexplained persistence of the Acanthamoeba keratitis outbreak in the United States, clusters abroad, and clinical studies reporting resolution or modification of Acanthamoeba keratitis without specific antiacanthamoebal therapy suggests that other contributing factors should be considered, including changes in the formulations used for empirical therapy of presumed infectious keratitis occurring in the same period.

Antimicrobial activity of calcium hydroxide and chlorhexidine on intratubular Candida albicans

PubMed Central

Jacques Rezende Delgado, Ronan; Helena Gasparoto, Thaís; Renata Sipert, Carla; Ramos Pinheiro, Claudia; Gomes de Moraes, Ivaldo; Brandão Garcia, Roberto; Antônio Hungaro Duarte, Marco; Monteiro Bramante, Clóvis; Aparecido Torres, Sérgio; Pompermaier Garlet, Gustavo; Paula Campanelli, Ana; Bernardineli, Norberti

2013-01-01

This study investigated the efficacy of calcium hydroxide and chlorhexidine gel for the elimination of intratubular Candida albicans (C. albicans). Human single-rooted teeth contaminated with C. albicans were treated with calcium hydroxide, 2% chlorhexidine gel, calcium hydroxide plus 2% chlorhexidine gel, or saline (0.9% sodium chloride) as a positive control. The samples obtained at depths of 0–100 and 100–200 µm from the root canal system were analyzed for C. albicans load by counting the number of colony forming units and for the percentage of viable C. albicans using fluorescence microscopy. First, the antimicrobial activity of calcium hydroxide and the 2% chlorhexidine gel was evaluated by counting the number of colony forming units. After 14 days of intracanal medication, there was a significant decrease in the number of C. albicans colony forming units at a depth of 0–100 µm with chlorhexidine treatment either with or without calcium hydroxide compared with the calcium hydroxide only treatment. However, there were no differences in the number of colony forming units at the 100–200 µm depth for any of the medications investigated. C. albicans viability was also evaluated by vital staining techniques and fluorescence microscopy analysis. Antifungal activity against C. albicans significantly increased at both depths in the chlorhexidine groups with and without calcium hydroxide compared with the groups treated with calcium hydroxide only. Treatments with only chlorhexidine or chlorhexidine in combination with calcium hydroxide were effective for elimination of C. albicans. PMID:23538639

Efficacy of antimicrobial agents incorporated in orthodontic bonding systems: a systematic review and meta-analysis.

PubMed

de Almeida, C M; da Rosa, W L O; Meereis, C T W; de Almeida, S M; Ribeiro, J S; da Silva, A F; Lund, Rafael Guerra

2018-06-01

The purpose of this study was to evaluate the efficacy of orthodontic bonding systems containing different antimicrobial agents, as well as the influence of antimicrobial agent incorporation in the bonding properties of these materials. Eight databases were searched: PubMed (Medline), Web of Science, Scopus, Lilacs, Ibecs, BBO, Scielo and Google Scholar. Any study that evaluated antimicrobial activity in experimental or commercial orthodontic bonding systems was included. Data were tabulated independently and in duplicated by two authors on pre-designed data collection form. The global analysis was carried out using a random-effects model, and pooled-effect estimates were obtained by comparing the standardised mean difference of each antimicrobial orthodontic adhesive with the respective control group. A p-value < .05 was considered as statistically significant. Thirty-two studies were included in the qualitative analysis; of these, 22 studies were included in the meta-analysis. Antimicrobial agents such as silver nanoparticles, benzalkonium chloride, chlorhexidine, triclosan, cetylpyridinium chloride, Galla chinensis extract, acid ursolic, dimethylaminododecyl methacrylate, dimethylaminohexadecyl methacrylate, 2-methacryloyloxyethyl phosphorylcholine, 1,3,5-triacryloylhexahydro-1,3,5-triazine, zinc oxide and titanium oxide have been incorporated into orthodontic bonding systems. The antimicrobial agent incorporation in orthodontic bonding systems showed higher antimicrobial activity than the control group in agar diffusion (overall standardised mean difference: 3.71; 95% CI 2.98 to 4.43) and optical density tests (0.41; 95% CI -0.05 to 0.86) (p < .05). However, for biofilm, the materials did not present antimicrobial activity (6.78; 95% CI 4.78 to 8.77). Regarding bond strength, the global analysis showed antimicrobial orthodontic bonding systems were statistically similar to the control. Although there is evidence of antibacterial activity from in vitro studies, clinical and long-term studies are still necessary to confirm the effectiveness of antibacterial orthodontic bonding systems in preventing caries disease.

Technical note: Could benzalkonium chloride be a suitable alternative to mercuric chloride for preservation of seawater samples?

NASA Astrophysics Data System (ADS)

Gloël, J.; Robinson, C.; Tilstone, G. H.; Tarran, G.; Kaiser, J.

2015-12-01

Instrumental equipment unsuitable or unavailable for fieldwork as well as lack of ship space can necessitate the preservation of seawater samples prior to analysis in a shore-based laboratory. Mercuric chloride (HgCl2) is routinely used for such preservation, but its handling and subsequent disposal incur environmental risks and significant expense. There is therefore a strong motivation to find less hazardous alternatives. Benzalkonium chloride (BAC) has been used previously as microbial inhibitor for freshwater samples. Here, we assess the use of BAC for marine samples prior to the measurement of oxygen-to-argon (O2 / Ar) ratios, as used for the determination of biological net community production. BAC at a concentration of 50 mg dm-3 inhibited microbial activity for at least 3 days in samples tested with chlorophyll a (Chl a) concentrations up to 1 mg m-3. BAC concentrations of 100 and 200 mg dm-3 were no more effective than 50 mg dm-3. With fewer risks to human health and the environment, and no requirement for expensive waste disposal, BAC could be a viable alternative to HgCl2 for short-term preservation of seawater samples, but is not a replacement for HgCl2 in the case of oxygen triple isotope analysis, which requires storage over weeks to months. In any event, further tests on a case-by-case basis should be undertaken if use of BAC was considered, since its inhibitory activity may depend on concentration and composition of the microbial community.

Uptake and phytotoxic effect of benzalkonium chlorides in Lepidium sativum and Lactuca sativa.

PubMed

Khan, Adnan Hossain; Libby, Mark; Winnick, Daniel; Palmer, John; Sumarah, Mark; Ray, Madhumita B; Macfie, Sheila M

2018-01-15

Cationic surfactants such as benzalkonium chlorides (BACs) are used extensively as biocides in hospitals, food processing industries, and personal care products. BACs have the potential to reach the rooting zone of crop plants and BACs might thereby enter the food chain. The two most commonly used BACs, benzyl dimethyl dodecyl ammonium chloride (BDDA) and benzyl dimethyl tetradecyl ammonium chloride (BDTA), were tested in a hydroponic system to assess the uptake by and phytotoxicity to lettuce (Lactuca sativa L.) and garden cress (Lepidium sativum L.). Individually and in mixture, BACs at concentrations up to 100 mg L -1 did not affect germination; however, emergent seedlings were sensitive at 1 mg L -1 for lettuce and 5 mg L -1 for garden cress. After 12 d exposure to 0.25 mg L -1 BACs, plant dry weight was reduced by 68% for lettuce and 75% for garden cress, and symptoms of toxicity (necrosis, chlorosis, wilting, etc.) were visible. High performance liquid chromatography-mass spectroscopy analysis showed the presence of BACs in the roots and shoots of both plant species. Although no conclusive relationship was established between the concentrations of six macro- or six micro-nutrients, growth inhibition or BAC uptake, N and Mg concentrations in BAC-treated lettuce were 50% lower than that of control, indicating that BACs might induce nutrient deficiency. Although bioavailability of a compound in hydroponics is significantly higher than that in soil, these results confirm the potential of BACs to harm vascular plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficacy of disinfecting solutions in removing biofilms from polyvinyl chloride tracheostomy tubes.

PubMed

Silva, Rodrigo C; Carver, Ryan A; Ojano-Dirain, Carolyn P; Antonelli, Patrick J

2013-01-01

Bacterial biofilms are prevalent in pediatric tracheostomy tubes (TTs) and are not completely cleared by standard cleaning with gauze and household detergents. We aimed to examine the effectiveness of different disinfecting solutions to remove Staphylococcus aureus (SA) and Pseudomonas aerginosa (PA) biofilms from TTs. Prospective, controlled, in vitro microbiologic study. Uniform coupons obtained from polyvinyl chloride (PVC) pediatric TTs were briefly exposed to human plasma. The samples were incubated in growth media with either PA or SA for 7 days, and total bacterial growth was monitored by media turbidity. Five sets of 18 coupons each were exposed for 5 minutes to one of five different solutions: 2% aqueous chlorhexidine gluconate solution, 0.3% aqueous sodium hypochlorite, Polident denture cleanser, 3% hydrogen peroxide, or preservative-free phosphate-buffered saline (PBS) as a negative control. Biofilm presence was measured with bacterial counts, and surface integrity was assessed with scanning electron microscopy (SEM). All treatments significantly reduced mean SA counts (P = <.001). Sodium hypochlorite and chlorhexidine were more effective than peroxide and Polident. Chlorhexidine, sodium hypochlorite, and peroxide reduced PA counts (P = .001, .001, and .002, respectively), but Polident tabs had no significant effect. SEM revealed preserved TT surface integrity after exposure to all solutions. Disinfection with sodium hypochlorite or chlorhexidine solutions significantly reduces SA and PA biofilms on PVC TTs. Standard home care of reusable pediatric TTs may be improved by use of these readily available solutions. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Cellulose Nanocrystal Entrapment of Benzalkonium Chloride in Southern Pine: Biological, Chemical, and Physical Properties

Treesearch

Carol A. Clausen; Vina W. Yang; Rachel A. Arango; Laura E. Hasburgh; Patricia K. Lebow; Richard S. Reiner

2015-01-01

Protecting wood products from biodeterioration has been a dynamic area of research in the past decade with an emphasis on the development of non-arsenical wood preservatives. Naturally occurring cellulose nanomaterials that are reported to have unique chemical properties, high strength, and stiffness were evaluated for the potential to improve durability of wood either...

Specific detection of membrane-toxic substances with a conductivity assay.

PubMed

Eich, J; Dürholt, H; Steger-Hartmann, T; Wagner, E

2000-03-01

A conductivity assay that represents a new biotest able to detect the effects of membrane-toxic compounds, e.g., detergents, organic solvents, and radical formers, on various organisms was previously described and developed. The conductivity assay measures ion leakage from cells, tissues, or whole plant and animal organisms whose membrane systems have been damaged by membrane-toxic compounds. In this study the specificity of the conductivity assay for membrane-toxic compounds was tested by comparing the electrolyte efflux from Elodea canadensis leaves during incubation with a well-known detergent (benzalkonium chloride) using different plant physiological and biochemical techniques (photochemical efficiency, plasmolysis capacity, NBT reduction, and electron microscopy of membranes of E. canadensis leaves). The comparison of the different methods proved that the electrolyte loss during benzalkonium chloride incubation determined in the conductivity assay is due to membrane impairment. The observed electrolyte loss correlated with a reduction of photochemical efficiency and a decrease in both plasmolysis and NBT reduction capacity. Furthermore, a disintegration of the plasmalemma could be seen in the electron micrographs. These results indicate that the measured electrolyte loss in the conductivity assay is a specific effect of membrane-toxic compounds. Copyright 2000 Academic Press.

Preliminary SEM Observations on the Surface of Elastomeric Impression Materials after Immersion or Ozone Disinfection

PubMed Central

Prombonas, Anthony; Yannikakis, Stavros; Karampotsos, Thanasis; Katsarou, Martha-Spyridoula; Drakoulis, Nikolaos

2016-01-01

Introduction Surface integrity of dental elastomeric impression materials that are subjected to disinfection is of major importance for the quality of the final prosthetic restorations. Aim The aim of this qualitative Scanning Electronic Microscopy (SEM) study was to reveal the effects of immersion or ozone disinfection on the surface of four dental elastomeric impression materials. Materials and Methods Four dental elastomeric impression material brands were used (two vinyl polysiloxane silicones, one polyether, and one vinyl polyether silicone). Total of 32 specimens were fabricated, eight from each impression material. Specimens were immersion (0.525% sodium hypochlorite solution or 0.3% benzalkonium chloride solution) or ozone disinfected or served as controls and examined with SEM. Results Surface degradation was observed on several speci-mens disinfected with 0.525% sodium hypochlorite solution. Similar wavy-wrinkling surface structures were observed in almost all specimens, when treated either with 0.3% benzalkonium chloride solution or ozone. Conclusion The SEM images obtained from this study revealed that both immersion disinfectants and ozone show similar impression material surface alterations. Ozone seems to be non-inferior as compared to immersion disinfectants, but superior as to environmental protection. PMID:28208993

Long-term exposure to benzalkonium chloride disinfectants results in change of microbial community structure and increased antimicrobial resistance.

PubMed

Tandukar, Madan; Oh, Seungdae; Tezel, Ulas; Konstantinidis, Konstantinos T; Pavlostathis, Spyros G

2013-09-03

The effect of benzalkonium chlorides (BACs), a widely used class of quaternary ammonium disinfectants, on microbial community structure and antimicrobial resistance was investigated using three aerobic microbial communities: BACs-unexposed (DP, fed a mixture of dextrin/peptone), BACs-exposed (DPB, fed a mixture of dextrin/peptone and BACs), and BACs-enriched (B, fed only BACs). Long-term exposure to BACs reduced community diversity and resulted in the enrichment of BAC-resistant species, predominantly Pseudomonas species. Exposure of the two microbial communities to BACs significantly decreased their susceptibility to BACs as well as three clinically relevant antibiotics (penicillin G, tetracycline, ciprofloxacin). Increased resistance to BACs and penicillin G of the two BACs-exposed communities is predominantly attributed to degradation or transformation of these compounds, whereas resistance to tetracycline and ciprofloxacin is largely due to the activity of efflux pumps. Quantification of several key multidrug resistance genes showed a much higher number of copies of these genes in the DPB and B microbial communities compared to the DP community. Collectively, our findings indicate that exposure of a microbial community to BACs results in increased antibiotic resistance, which has important implications for both human and environmental health.

The mixture of liquid foam soap, ethanol and citric acid as a new fixative-preservative solution in veterinary anatomy.

PubMed

Turan, Erkut; Gules, Ozay; Kilimci, Figen Sevil; Kara, Mehmet Erkut; Dilek, Omer Gurkan; Sabanci, Seyyid Said; Tatar, Musa

2017-01-01

The present study investigates the efficiency of liquid foam soap, ethanol, citric acid and benzalkonium chloride as a fixative-preservative solution (a soap-and ethanol-based fixing solution, or SEFS). In this study, ethanol serves as the fixative and preservative, liquid foam soap as the modifying agent, citric acid as the antioxidant and benzalkonium chloride as the disinfectant. The goat cadavers perfused with SEFS (n=8) were evaluated over a period of one year with respect to hardness, colour and odour using objective methods. Colour and hardness were compared between one fresh cadaver and the SEFS-embalmed cadavers. Histological and microbiological examinations were also performed in tissue samples. Additionally, the cadavers were subjectively evaluated after dissection and palpation. The SEFS provided the effectiveness expected over a 1-year embalming period for the animal cadavers. No bacteria or fungi were isolated except for some non-pathogenic Bacillus species. Visible mould was not present on either cadavers or in the surrounding environment. The cadavers maintained an appearance close to their original anatomical appearance, with muscles having good hardness and elasticity for dissection. Copyright © 2016 Elsevier GmbH. All rights reserved.

In Vitro and in Vivo Experimental Studies on Trabecular Meshwork Degeneration Induced by Benzalkonium Chloride (An American Ophthalmological Society Thesis)

PubMed Central

Baudouin, Christophe; Denoyer, Alexandre; Desbenoit, Nicolas; Hamm, Gregory; Grise, Alice

2012-01-01

Purpose: Long-term antiglaucomatous drug administration may cause irritation, dry eye, allergy, subconjunctival fibrosis, or increased risk of glaucoma surgery failure, potentially due to the preservative benzalkonium chloride (BAK), whose toxic, proinflammatory, and detergent effects have extensively been shown experimentally. We hypothesize that BAK also influences trabecular meshwork (TM) degeneration. Methods: Trabecular specimens were examined using immunohistology and reverse transcriptase–polymerase chain reaction. A trabecular cell line was stimulated by BAK and examined for apoptosis, oxidative stress, fractalkine and SDF-1 expression, and modulation of their receptors. An experimental model was developed with BAK subconjunctival injections to induce TM degeneration. Mass spectrometry (MS) imaging assessed BAK penetration after repeated instillations in rabbit eyes. Results: Trabecular specimens showed extremely low densities of trabecular cells and presence of cells expressing fractalkine and fractalkine receptor and their respective mRNAs. Benzalkonium in vitro induced apoptosis, oxidative stress, and fractalkine expression and inhibited the protective chemokine SDF-1 and Bcl2, also inducing a sustained intraocular pressure (IOP) increase, with dramatic apoptosis of trabecular cells and reduction of aqueous outflow. MS imaging showed that BAK could access the TM at measurable levels after repeated instillations. Conclusion: BAK enhances all characteristics of TM degeneration typical of glaucoma—trabecular apoptosis, oxidative stress, induction of inflammatory chemokines—and causes degeneration in acute experimental conditions, potentially mimicking long-term accumulation. BAK was also shown to access the TM after repeated instillations. These findings support the hypothesis that antiglaucoma medications, through toxicity of their preservative, may cause further long-term trabecular degeneration and therefore enhance outflow resistance, reducing the impact of IOP-lowering agents. PMID:23818734

In vitro and in vivo experimental studies on trabecular meshwork degeneration induced by benzalkonium chloride (an American Ophthalmological Society thesis).

PubMed

Baudouin, Christophe; Denoyer, Alexandre; Desbenoit, Nicolas; Hamm, Gregory; Grise, Alice

2012-12-01

Long-term antiglaucomatous drug administration may cause irritation, dry eye, allergy, subconjunctival fibrosis, or increased risk of glaucoma surgery failure, potentially due to the preservative benzalkonium chloride (BAK), whose toxic, proinflammatory, and detergent effects have extensively been shown experimentally. We hypothesize that BAK also influences trabecular meshwork (TM) degeneration. Trabecular specimens were examined using immunohistology and reverse transcriptase-polymerase chain reaction. A trabecular cell line was stimulated by BAK and examined for apoptosis, oxidative stress, fractalkine and SDF-1 expression, and modulation of their receptors. An experimental model was developed with BAK subconjunctival injections to induce TM degeneration. Mass spectrometry (MS) imaging assessed BAK penetration after repeated instillations in rabbit eyes. Trabecular specimens showed extremely low densities of trabecular cells and presence of cells expressing fractalkine and fractalkine receptor and their respective mRNAs. Benzalkonium in vitro induced apoptosis, oxidative stress, and fractalkine expression and inhibited the protective chemokine SDF-1 and Bcl2, also inducing a sustained intraocular pressure (IOP) increase, with dramatic apoptosis of trabecular cells and reduction of aqueous outflow. MS imaging showed that BAK could access the TM at measurable levels after repeated instillations. BAK enhances all characteristics of TM degeneration typical of glaucoma-trabecular apoptosis, oxidative stress, induction of inflammatory chemokines-and causes degeneration in acute experimental conditions, potentially mimicking long-term accumulation. BAK was also shown to access the TM after repeated instillations. These findings support the hypothesis that antiglaucoma medications, through toxicity of their preservative, may cause further long-term trabecular degeneration and therefore enhance outflow resistance, reducing the impact of IOP-lowering agents.

Development of a Protocol for Predicting Bacterial Resistance to Microbicides

PubMed Central

Knapp, Laura; Amézquita, Alejandro; McClure, Peter; Stewart, Sara

2015-01-01

Regulations dealing with microbicides in Europe and the United States are evolving and now require data on the risk of the development of resistance in organisms targeted by microbicidal products. There is no standard protocol to assess the risk of the development of resistance to microbicidal formulations. This study aimed to validate the use of changes in microbicide and antibiotic susceptibility as initial markers for predicting microbicide resistance and cross-resistance to antibiotics. Three industrial isolates (Pseudomonas aeruginosa, Burkholderia cepacia, and Klebsiella pneumoniae) and two Salmonella enterica serovar Typhimurium strains (SL1344 and 14028S) were exposed to a shampoo, a mouthwash, eye makeup remover, and the microbicides contained within these formulations (chlorhexidine digluconate [CHG] and benzalkonium chloride [BZC]) under realistic, in-use conditions. Baseline and postexposure data were compared. No significant increases in the MIC or the minimum bactericidal concentration (MBC) were observed for any strain after exposure to the three formulations. Increases as high as 100-fold in the MICs and MBCs of CHG and BZC for SL1344 and 14028S were observed but were unstable. Changes in antibiotic susceptibility were not clinically significant. The use of MICs and MBCs combined with antibiotic susceptibility profiling and stability testing generated reproducible data that allowed for an initial prediction of the development of resistance to microbicides. These approaches measure characteristics that are directly relevant to the concern over resistance and cross-resistance development following the use of microbicides. These are low-cost, high-throughput techniques, allowing manufacturers to provide to regulatory bodies, promptly and efficiently, data supporting an early assessment of the risk of resistance development. PMID:25636848

Presence of antiseptic resistance genes in porcine methicillin-resistant Staphylococcus aureus.

PubMed

Wong, T Z; Zhang, M; O'Donoghue, M; Boost, M

2013-03-23

Numerous studies have documented the presence of methicillin-resistant Staphylococcus aureus (MRSA) in meat-producing animals, which has led to concern about its spread into the community. Disinfectants play an important role in reduction of contamination in both animal husbandry and food-preparation, helping control spread of organisms from foodstuffs, including raw meat. Plasmid-borne antiseptic resistance (AR) genes increasing tolerance to several disinfectants have been reported in S. aureus of human origin (qacA/B and smr) and from bovine, equine, and caprine staphylococcal isolates (qacG, qacH, and qacJ). This study investigated the presence of AR genes in porcine MRSA isolates. Plasmid DNA from 100 MRSA ST9 strains isolated from pig carcasses was amplified for the presence of AR genes. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) to benzalkonium chloride (BC) and chlorhexidine gluconate (CHX) were determined in AR gene-positive isolates. qacG was present in 45 strains, eight of which also harbored smr. No strains carried qacA/B, qacH or qacJ. Presence of smr increased MICs to both BC and CHX and MBCs of CHX, but qacG presence only resulted in elevated MBC for CHX. This is the first report of AR genes from a porcine source. AR gene positivity has previously been associated with methicillin resistance and AR gene presence in these strains may increase their ability to persist in the environment. Improved implementation of hygiene measures during transportation and pre- and post-slaughter should be considered to prevent spread in the community. Copyright © 2012 Elsevier B.V. All rights reserved.

Development and validation of an HPLC/UV/MS method for simultaneous determination of 18 preservatives in grapefruit seed extract.

PubMed

Ganzera, Markus; Aberham, Anita; Stuppner, Hermann

2006-05-31

Grapefruit seed extracts are used in cosmetics, food supplements, and pesticides because of their antimicrobial properties, but suspicions about the true nature of the active compounds arose when synthetic disinfectants such as benzethonium or benzalkonium chloride were found in commercial products. The HPLC method presented herein allows the quality assessment (qualitative and quantitative) of these products for the first time. On the basis of a standard mixture of 18 preservatives most relevant for food and grapefruit products, a method was developed allowing the baseline separation of all compounds within 40 min. Optimum results were obtained with a C-8 stationary phase and a solvent system comprising aqueous trifluoroacetic acid, acetonitrile, and 2-propanol. The assay was fully validated and shown to be sensitive (LOD < or= 12.1 ng on-column), accurate (recovery rates > or = 96.1%), repeatable (sigma(rel) < or = 3.5%), precise (intra-day variation < or = 4.5%, interday variation < or = 4.1%), and rugged. Without any modifications the method could be adopted for LC-MS experiments, where the compounds of interest were directly assignable in positive ESI mode. The quantitative results of several products for ecofarming confirmed previous studies, as seven out of nine specimens were adulterated with preservatives in varying composition. The samples either contained benzethonium chloride (2.5-176.9 mg/mL) or benzalkonium chloride (138.2-236.3 mg/mL), together with smaller amounts of 4-hydroxybenzoic acid esters, benzoic acid, and salicylic acid.

Not only biocidal products: Washing and cleaning agents and personal care products can act as further sources of biocidal active substances in wastewater.

PubMed

Wieck, Stefanie; Olsson, Oliver; Kümmerer, Klaus

2018-06-01

The emission sources of biocidal active substances in households have been under discussion since these substances have been detected frequently in municipal wastewater and receiving surface water bodies. Therefore, the goal of this study was to investigate the products responsible for the emission of these substances to wastewater. We analysed the wastewater of two streets for a set of biocidal active substances. Time-proportional sampling was conducted for one week of each season during one year in each street. The 14 substances analysed with liquid chromatography coupled with tandem mass spectrometry were 1,2-benzisothiazol-3(2H)-one (BIT), C 12 -benzalkonium chloride, carbendazim, 5-chloro-2-methyl-2H-isothiazol-3-one (CMIT), dichlorooctylisothiazolinone (DCOIT), N,N-diethyl-meta-toluamide (DEET), diuron, icaridine, 2-octyl-2H-isothiazol-3-one (OIT), piperonyl butoxide (PBO), triclosan, tebuconazole, terbutryn and tetramethrin. Using data available from household product inventories of the two streets, we searched the lists of ingredients for the products possibly being responsible for the emissions. Except for four substances, all substances have been detected in at least 10% of the samples. Highest concentrations were measured for C 12 -benzalkonium chloride with an average concentration in the daily samples of 7.7 μg/L in one of the streets. Next to C 12 -benzalkonium chloride, BIT, DEET and icaridine were detected in all samples in average concentrations above 1 μg/L in at least one street. The results show that washing and cleaning agents were important sources for preservatives such as BIT and OIT, while triclosan was apparently mainly emitted through personal care products. The mosquito repelling substances DEET and icaridine were found throughout the year, with highest emissions in summer and autumn. In conclusion, the results demonstrate that the sources of biocidal active substances in municipal wastewater are complex and that measures for the prevention of the emission of biocidal active substances into the aquatic environment have to be carried out under different legislations. This has to be taken into account discussing emission reduction at the source. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparison of irrigation solutions and devices in a contaminated musculoskeletal wound survival model.

PubMed

Owens, Brett D; White, Daniel W; Wenke, Joseph C

2009-01-01

There is much to learn about the effectiveness of different methods currently used for the irrigation of open wounds. The purpose of this study was to compare various approaches in a survival animal model. We used an established goat model involving the creation of a reproducible complex musculoskeletal wound followed by inoculation with Pseudomonas aeruginosa (lux) bacteria. This genetically altered luminescent bacterium provides the ability for quantitative analysis with a photon-counting camera system. For Study 1, wound irrigation was performed six hours after the injury and inoculation; the goats were assigned to four treatment groups: normal saline solution, bacitracin solution, castile soap, and benzalkonium chloride. All wounds received sharp débridement and irrigation with use of a pulsatile lavage device (19 psi). Images and photon counts were obtained prior to irrigation, after irrigation, and forty-eight hours after injury and inoculation. For Study 2, we used the same animal model and compared bulb syringe and pulsatile lavage irrigation with saline solution. In Study 1, the irrigation treatment lowered the bacterial counts in all treatment groups. The greatest reduction was seen with castile soap, which lowered the photon count to 13% of the pretreatment level. This was followed by benzalkonium chloride, bacitracin, and saline solution at 18%, 22%, and 29%, respectively. At forty-eight hours, imaging showed a rebound in bacterial counts in every group. The highest rebound was measured in the castile soap group, which rebounded to 120% of the pretreatment level. The benzalkonium chloride group experienced a rebound to 94% of the pretreatment level. These were followed by bacitracin solution (89%) and normal saline solution (68%). In Study 2, both treatment methods were effective in removing 75% of the bacteria initially. At forty-eight hours, the bacterial levels in the pulsed lavage group rebounded to 94% of the original levels (compared with 48% in the bulb syringe group). The difference in the mean photon count ratios at forty-eight hours was significant (p = 0.048). Approaches used to remove bacteria from wounds, such as irrigants other than saline solution or high-pressure devices, may not have the best clinical outcome.

Effectiveness of a mouthrinse containing active ingredients in addition to chlorhexidine and triclosan compared with chlorhexidine and triclosan rinses on plaque, gingivitis, supragingival calculus and extrinsic staining.

PubMed

Kumar, S; Patel, S; Tadakamadla, J; Tibdewal, H; Duraiswamy, P; Kulkarni, S

2013-02-01

To assess the effectiveness of three different mouthrinses--chlorhexidine, triclosan + sodium fluoride and chlorhexidine + triclosan + sodium fluoride + zinc chloride--on plaque, calculus, gingivitis and stains and to evaluate the occurrence of adverse effects with these three treatments. Forty-eight healthy subjects participated in a double-blind, randomized, parallel experiment and were randomly allocated to any one of the three experimental mouthrinses: group A (0.2% chlorhexidine (CHX) gluconate), group B (0.03% triclosan + 0.025% sodium fluoride (NaF) + 12% ethyl alcohol) or group C (0.2% CHX + 0.3% triclosan + 0.3% NaF + 0.09% Zn chloride (ZnCl(2)). All the subjects were assessed for gingivitis, plaque, supragingival calculus and extrinsic stains at baseline and at the end of the 21-day experimental period. There was a significant difference (P = 0.046) in the effectiveness for the prevention of gingivitis and plaque, with subjects of group A and group C presenting least and highest gingival and plaque scores, respectively. Significant differences (P = 0.03) were observed for the accumulation of supragingival calculus where the deposition of calculus in group A was nearly double that of the group B, and group B was most effective in the prevention of supragingival calculus. Highest deposition of extrinsic stains was in the group A followed by group C and group B. There was no significant difference between the three treatments for adverse events' occurrence. CHX mouthrinse was most effective in controlling plaque and gingivitis but caused greatest deposition of extrinsic stains. Supragingival calculus deposition was least in triclosan + NaF group followed by CHX + triclosan + NaF + ZnCl(2) and CHX. More than half of the subjects reported adverse events during the experimental phase. © 2012 John Wiley & Sons A/S.

Long-Term Bond Strength of Two Benzalkonium Chloride-Modified Adhesive Systems to Eroded Dentin

PubMed Central

Lussi, Adrian; Peutzfeldt, Anne

2017-01-01

This study investigated the effect of benzalkonium chloride (BAC) modification of two adhesive systems on long-term bond strength to normal and artificially eroded dentin. A total of 128 extracted human molars were sectioned and the buccal and oral surfaces of each molar were ground until the dentin. One half was left untreated (normal dentin) while the other half underwent artificial erosion. Resin composite was bonded to the buccal or oral surface following treatment with Adper Scotchbond 1XT or OptiBond FL without or with 1% BAC incorporation. Shear bond strength (SBS) was measured after 24 h (100% humidity, 37°C) or 1 year (tap water, 37°C). SBS results were statistically analyzed (α = 0.05). SBS was significantly lower to artificially eroded dentin than to normal dentin (p < 0.001). Storage for 1 year had no effect on SBS to normal dentin but led to a significant decrease in SBS to artificially eroded dentin (p < 0.001). BAC incorporation decreased the 24 h SBS to normal dentin (p = 0.018), increased the 24 h SBS to eroded dentin (p = 0.001), and had no effect on the 1-year SBS for either substrate. Consequently, BAC incorporation did not improve bond durability. PMID:28875148

Genoprotective effect of hyaluronic acid against benzalkonium chloride-induced DNA damage in human corneal epithelial cells

PubMed Central

Wu, Han; Zhang, Huina; Wang, Changjun; Wu, Yihua; Xie, Jiajun; Jin, Xiuming; Yang, Jun

2011-01-01

Purpose The aim of this study was to investigate hyaluronic acid (HA) protection on cultured human corneal epithelial cells (HCEs) against benzalkonium chloride (BAC)-induced DNA damage and intracellular reactive oxygen species (ROS) increase. Methods Cells were incubated with different concentrations of BAC with or without the presence of 0.2% HA for 30 min. DNA damage to HCEs was examined by alkaline comet assay and by immunofluorescence microscopic detection of the phosphorylated form of histone variant H2AX (γH2AX) foci. ROS production was assessed by the fluorescent probe, 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). Cell apoptosis was determined with annexin V staining by flow cytometry. Results HA significantly reduced BAC-induced DNA damage as indicated by the tail length (TL) and tail moment (TM) of alkaline comet assay and by γH2AX foci formation, respectively. Moreover, HA significantly decreased BAC-induced ROS increase and cell apoptosis. However, exposure to HA alone did not produce any significant change in DNA damage, ROS generation, or cell apoptosis. Conclusions BAC could induce DNA damage and cell apoptosis in HCEs, probably through increasing oxidative stress. Furthermore, HA was an effective protective agent that had antioxidant properties and could decrease DNA damage and cell apoptosis induced by BAC. PMID:22219631

The mucosal toxicity of different benzalkonium chloride analogues evaluated with an alternative test using slugs.

PubMed

Adriaens, E; Dierckens, K; Bauters, T G; Nelis, H J; van Goethem, F; Vanparys, P; Remon, J P

2001-07-01

The objective of this study was to evaluate the mucosal toxicity of different benzalkonium chloride (BAC) analogues using slugs as the alternative test organism. The effect of different BAC analogues on the mucosal tissue of slugs was determined from the protein, lactate dehydrogenase, and alkaline phosphatase released from the foot mucosa after treatment. Additionally, mucus production and reduction in body weight of the slugs were measured. The eye irritation potency of the molecules was evaluated with the Bovine Corneal Opacity and Permeability (BCOP) assay. The antimicrobial activity of the different BAC analogues was also assessed. All BAC analogues induced severe damage to the mucosal epithelium of the slugs, and the irritation increased with decreasing alkyl chain length: BAC-C16 < BAC-C14 < BAC-C12 approximately BAC-mix. A similar ranking was obtained with the BCOP assay for eye irritation. The relative order of activities among the three BAC analogues was the same, i.e., BAC-C14 > or = BAC-C16 > BAC-C12. The BAC-C14 exhibited higher activity than the BAC-mix. The toxicity and activity of BAC analogues depend on the alkyl chain length. The use of BAC-C14 as a conservative agent in pharmaceutical preparations instead of the BAC-mix should be considered.

Morphological and functional changes after benzalkonium chloride treatment of the small intestinal Thiry-Vella loop in rats.

PubMed

Móricz, K; Gyetvai, B; Bárdos, G

1998-08-01

The aim of this work was to study the effects of benzalkonium chloride (BAC) treatment on the small intestine and its functioning in rats surgically prepared with Thiry-Vella intestinal loop. The loops were treated with either BAC, which ablated much of the myenteric plexus and extrinsic innervation, or with physiological saline (SAL). In vivo drinking experiments were performed to examine the effect on fluid intake and behavioral indices of distending the loop with a balloon. Spontaneous motility and its changes induced by acetylcholine (ACh) and histamine (His) were studied on isolated stripes in vitro. Finally, samples from the loops were examined histologically. Though reduction of the cell number was less than expected and no differences of the thickness of the muscular layer between the two groups was observed, BAC treatment altered the pattern of spontaneous activity and also the sensitivity to ACh and His in isolated stripes. In vivo distension of the SAL-treated loops reduced fluid intake and produced signs of aversivity; these effects were absent in the BAC-treated group. Our results show that despite the differences in the degree of ablation from those obtained by others, BAC treatment can be used to study the mechanisms underlying the effects of the enteral stimuli on the behavior.

Efflux mediated adaptive and cross resistance to ciprofloxacin and benzalkonium chloride in Pseudomonas aeruginosa of dairy origin.

PubMed

Pagedar, Ankita; Singh, Jitender; Batish, Virender K

2011-06-01

The present study was undertaken to investigate the role of efflux pump activity (EPA) in conferring adaptive and cross resistances against ciprofloxacin (CF) and benzalkonium chloride (BC) in dairy isolates of Pseudomonas aeruginosa. Biofilm formation potential was correlated with development of adaptive resistance in originally resistant strains. Irrespective of parent strains's susceptibility, isolates developed substantial adaptive resistance against CF and BC. Significant difference was observed in ability of non resistant isolates to develop adaptive resistance against CF and BC (P < 0.02) and subsequent cross resistance. EPA was quantified using EtBr (Ethidium Bromide) model and its role was more prominent [confirmed by its inhibition using efflux pump inhibitor (EPI) 2,4-dinitrophenol (DNP)], in conferring adaptive resistance (P = 0.147) than cross resistance (P = 0.343). Reduction in adaptive resistances due to EPI was more evident in originally non resistant strains, which reaffirms EPA as probable mechanism of adaptive resistance. The present study perhaps first of its kind, suggests an active role of EPA in conferring adaptive and cross resistances in food related P. aeruginosa isolates and supports reverse hypothesis that antibiotic-resistant organisms eventually become tolerant to other antibacterial agents as well. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Short-term effects of benzalkonium chloride and atrazine on Elodea canadensis using a miniaturised microbioreactor system for an online monitoring of physiologic parameters.

PubMed

Vervliet-Scheebaum, Marco; Ritzenthaler, Raphael; Normann, Johannes; Wagner, Edgar

2008-02-01

The study evaluated the effects of benzalkonium chloride (BAC) and atrazine on the macrophyte Elodea canadensis (Michaux) using a miniaturised monitoring test system consisting of a microbioreactor of reduced volume and integrated sensors for the online measurement of physiologic parameters, like oxygen production and different parameters of fluorescence. Different concentrations of both chemicals were applied to leaves of E. canadensis and the physiologic endpoints evaluated after 1h. A concentration-dependent reduction of the oxygen production and of the effective quantum yield of energy conversion was recorded. The mini-PAM technique implemented in the presented system allowed for a clear monitoring of the kinetic of BAC and atrazine, showing their distinct mode of action. No observable adverse effects were recorded up to concentrations of 2.5 mg/L and 10 microg/L, for BAC and atrazine, respectively. These values are in accordance with available results in the literature, hence indicating that the microbioreactor test system might be suitable, on the one hand, for the laboratory screening of potential short-term toxicity of contaminants on aquatic plants, and on the other hand, serve as an in situ field biomonitoring system for the rapid detection of pollutants in water.

Subminimal Inhibitory Concentrations of the Disinfectant Benzalkonium Chloride Select for a Tolerant Subpopulation of Escherichia coli with Inheritable Characteristics

PubMed Central

Moen, Birgitte; Rudi, Knut; Bore, Erlend; Langsrud, Solveig

2012-01-01

Exposure of Escherichia coli to a subminimal inhibitory concentration (25% below MIC) of benzalkonium chloride (BC), an antimicrobial membrane-active agent commonly used in medical and food-processing environments, resulted in cell death and changes in cell morphology (filamentation). A small subpopulation (1–5% of the initial population) survived and regained similar morphology and growth rate as non-exposed cells. This subpopulation maintained tolerance to BC after serial transfers in medium without BC. To withstand BC during regrowth the cells up regulated a drug efflux associated gene (the acrB gene, member of the AcrAB-TolC efflux system) and changed expression of outer membrane porin genes (ompFW) and several genes involved in protecting the cell from the osmotic- and oxidative stress. Cells pre-exposed to osmotic- and oxidative stress (sodium chloride, salicylic acid and methyl viologen) showed higher tolerance to BC. A control and two selected isolates showing increased BC-tolerance after regrowth in BC was genome sequenced. No common point mutations were found in the BC- isolates but one point mutation in gene rpsA (Ribosomal protein S1) was observed in one of the isolates. The observed tolerance can therefore not solely be explained by the observed point mutation. The results indicate that there are several different mechanisms responsible for the regrowth of a tolerant subpopulation in BC, both BC-specific and general stress responses, and that sub-MIC of BC may select for phenotypic variants in a sensitive E. coli culture. PMID:22605968

Subminimal inhibitory concentrations of the disinfectant benzalkonium chloride select for a tolerant subpopulation of Escherichia coli with inheritable characteristics.

PubMed

Moen, Birgitte; Rudi, Knut; Bore, Erlend; Langsrud, Solveig

2012-01-01

Exposure of Escherichia coli to a subminimal inhibitory concentration (25% below MIC) of benzalkonium chloride (BC), an antimicrobial membrane-active agent commonly used in medical and food-processing environments, resulted in cell death and changes in cell morphology (filamentation). A small subpopulation (1-5% of the initial population) survived and regained similar morphology and growth rate as non-exposed cells. This subpopulation maintained tolerance to BC after serial transfers in medium without BC. To withstand BC during regrowth the cells up regulated a drug efflux associated gene (the acrB gene, member of the AcrAB-TolC efflux system) and changed expression of outer membrane porin genes (ompFW) and several genes involved in protecting the cell from the osmotic- and oxidative stress. Cells pre-exposed to osmotic- and oxidative stress (sodium chloride, salicylic acid and methyl viologen) showed higher tolerance to BC. A control and two selected isolates showing increased BC-tolerance after regrowth in BC was genome sequenced. No common point mutations were found in the BC- isolates but one point mutation in gene rpsA (Ribosomal protein S1) was observed in one of the isolates. The observed tolerance can therefore not solely be explained by the observed point mutation. The results indicate that there are several different mechanisms responsible for the regrowth of a tolerant subpopulation in BC, both BC-specific and general stress responses, and that sub-MIC of BC may select for phenotypic variants in a sensitive E. coli culture.

Effectiveness of Oral Antiseptics on Tooth Biofilm: A Study in vivo.

PubMed

Mouchrek Junior, José Carlos Elias; Nunes, Lívia Helena de Araújo Castro; Arruda, Cleidiane Silveira; Rizzi, Claudia de Castro; Mouchrek, Adriana Quinzeiro E Silva; Tavarez, Rudys Rodolfo De Jesus; Tonetto, Mateus Rodrigues; Bandeca, Matheus Coelho; Maia Filho, Etevaldo Matos

2015-08-01

To evaluate the effectiveness of five different mouthwashes through measurement of the plaque index. Fifty subjects took part in this blind study, randomized into blocks of five groups according to the active ingredient of the mouthwash: CHX group (0.12% chlorhexidine gluconate), essential oils (EO) group, cetylpyridinium chloride (CPC) group, Tri group (triclosan) and Hamamelis virginiana (HV) group. All subjects were evaluated for a reduction in the bacterial plaque index at 7, 14 and 21 days. There was a significant reduction in the mean plaque index during the period of evaluation (p < 0.01), and the reduction during the period of evaluation was different between mouthwashes (p < 0.01). The reduction in the plaque index at the end of 21 days was, in decreasing order, CHX > EO > CPC > Tri > HV. The reduction in the plaque index during the period of evaluation was different between the types of mouth-wash. The mouthwash containing the active ingredient chlorhexidine was the most effective, followed by the essential oil, cetylpyridinium chloride, triclosan and H. virginiana.

Outer membrane changes in Pseudomonas stutzeri resistant to chlorhexidine diacetate and cetylpyridinium chloride.

PubMed

Tattawasart, U; Maillard, J Y; Furr, J R; Russell, A D

2000-11-01

Changes in outer membrane proteins (OMP) and lipopolysaccharide (LPS) in cells of strains of Pseudomonas stutzeri sensitive and resistant to chlorhexidine diacetate (CHA) or cetylpyridinium chloride (CPC) have been examined. Four of five CHA-resistant strains had alterations in OMP profiles, including the expression of two additional protein bands. All the CPC-resistant strains had altered OMP profiles but the changes varied from strain to strain. Loss of the fastest-migrating bands was observed in the LPS from CHX-resistant strains. In strain JM 302R with high-level CHX resistance (minimal inhibitory concentration 100 mg/l as opposed to 2.5 mg/l in the parent-strain, JM 302), all the fast-migrating bands were lost and the strain showed 'cross-resistance' to polymyxin, gentamicin and ethylenediamine tetraacetic acid. It is however, possible that the altered LPS patterns reflect a response to alterations in other components rather than being directly associated per se with the enhanced resistance.

Efficacy of Biocides Used in the Modern Food Industry To Control Salmonella enterica, and Links between Biocide Tolerance and Resistance to Clinically Relevant Antimicrobial Compounds

PubMed Central

Condell, Orla; Iversen, Carol; Cooney, Shane; Power, Karen A.; Walsh, Ciara; Burgess, Catherine

2012-01-01

Biocides play an essential role in limiting the spread of infectious disease. The food industry is dependent on these agents, and their increasing use is a matter for concern. Specifically, the emergence of bacteria demonstrating increased tolerance to biocides, coupled with the potential for the development of a phenotype of cross-resistance to clinically important antimicrobial compounds, needs to be assessed. In this study, we investigated the tolerance of a collection of susceptible and multidrug-resistant (MDR) Salmonella enterica strains to a panel of seven commercially available food-grade biocide formulations. We explored their abilities to adapt to these formulations and their active biocidal agents, i.e., triclosan, chlorhexidine, hydrogen peroxide, and benzalkonium chloride, after sequential rounds of in vitro selection. Finally, cross-tolerance of different categories of biocidal formulations, their active agents, and the potential for coselection of resistance to clinically important antibiotics were investigated. Six of seven food-grade biocide formulations were bactericidal at their recommended working concentrations. All showed a reduced activity against both surface-dried and biofilm cultures. A stable phenotype of tolerance to biocide formulations could not be selected. Upon exposure of Salmonella strains to an active biocidal compound, a high-level of tolerance was selected for a number of Salmonella serotypes. No cross-tolerance to the different biocidal agents or food-grade biocide formulations was observed. Most tolerant isolates displayed changes in their patterns of susceptibility to antimicrobial compounds. Food industry biocides are effective against planktonic Salmonella. When exposed to sublethal concentrations of individual active biocidal agents, tolerant isolates may emerge. This emergence was associated with changes in antimicrobial susceptibilities. PMID:22367085

Efficacy of biocides used in the modern food industry to control salmonella enterica, and links between biocide tolerance and resistance to clinically relevant antimicrobial compounds.

PubMed

Condell, Orla; Iversen, Carol; Cooney, Shane; Power, Karen A; Walsh, Ciara; Burgess, Catherine; Fanning, Séamus

2012-05-01

Biocides play an essential role in limiting the spread of infectious disease. The food industry is dependent on these agents, and their increasing use is a matter for concern. Specifically, the emergence of bacteria demonstrating increased tolerance to biocides, coupled with the potential for the development of a phenotype of cross-resistance to clinically important antimicrobial compounds, needs to be assessed. In this study, we investigated the tolerance of a collection of susceptible and multidrug-resistant (MDR) Salmonella enterica strains to a panel of seven commercially available food-grade biocide formulations. We explored their abilities to adapt to these formulations and their active biocidal agents, i.e., triclosan, chlorhexidine, hydrogen peroxide, and benzalkonium chloride, after sequential rounds of in vitro selection. Finally, cross-tolerance of different categories of biocidal formulations, their active agents, and the potential for coselection of resistance to clinically important antibiotics were investigated. Six of seven food-grade biocide formulations were bactericidal at their recommended working concentrations. All showed a reduced activity against both surface-dried and biofilm cultures. A stable phenotype of tolerance to biocide formulations could not be selected. Upon exposure of Salmonella strains to an active biocidal compound, a high-level of tolerance was selected for a number of Salmonella serotypes. No cross-tolerance to the different biocidal agents or food-grade biocide formulations was observed. Most tolerant isolates displayed changes in their patterns of susceptibility to antimicrobial compounds. Food industry biocides are effective against planktonic Salmonella. When exposed to sublethal concentrations of individual active biocidal agents, tolerant isolates may emerge. This emergence was associated with changes in antimicrobial susceptibilities.

Genetic relatedness, antimicrobial and biocide susceptibility comparative analysis of methicillin-resistant and -susceptible Staphylococcus pseudintermedius from Portugal.

PubMed

Couto, Natacha; Belas, Adriana; Couto, Isabel; Perreten, Vincent; Pomba, Constança

2014-08-01

Forty methicillin-resistant and -susceptible Staphylococcus pseudintermedius (MRSP and MSSP, respectively) from colonization and infection in dogs and cats were characterized for clonality, antimicrobial, and biocide susceptibility. MSSP were genetically more diverse than MRSP by multi-locus sequence typing and pulsed-field gel electrophoresis. Three different spa types (t06, t02, t05) and two SCCmec types (II-III and V) were detected in the MRSP isolates. All MRSP and two MSSP strains were multidrug-resistant. Several antibiotic resistance genes (mecA, blaZ, tet(M), tet(K), aac(6')-Ie-aph(2')-Ia, aph(3')-III, ant(6)-Ia, sat4, erm(B), lnu(A), dfr(G), and catp(C221)) were identified by microarray and double mutations in the gyrA and grlA genes and a single mutation in the rpoB gene were detected by sequence analysis. No differences were detected between MSSP and MRSP in the chlorhexidine acetate (CHA) minimum inhibitory concentrations (MICs). However, two MSSP had elevated MIC to triclosan (TCL) and one to benzalkonium chloride and ethidium bromide. One MSSP isolate harboured a qacA gene, while in another a qacB gene was detected. None of the isolates harboured the sh-fabI gene. Three of the biocide products studied had high bactericidal activity (Otodine(®), Clorexyderm Spot Gel(®), Dermocanis Piocure-M(®)), while Skingel(®) failed to achieve a five log reduction in the bacterial counting. S. pseudintermedius have become a serious therapeutic challenge in particular if methicillin- resistance and/or multidrug-resistance are involved. Biocides, like CHA and TCL, seem to be clinically effective and safe topical therapeutic options.

Influence of growth media on the sensitivity of Staphylococcus aureus and Pseudomonas aeruginosa to cationic biocides.

PubMed

Brill, Florian; Goroncy-Bermes, Peter; Sand, Wolfgang

2006-01-01

In this study, the influence of culturing Staphylococcus aureus and Pseudomonas aeruginosa under different growth conditions on their inactivation by the cationic active compounds benzalkonium chloride, chlorhexidine digluconate and octenidine dihydrochloride was investigated. Cells were grown in non-agitated tryptone soya broth as well as on tryptone soya agar according to national and international standards for evaluating chemical disinfectants. In quantitative suspension tests, cells of both test organisms grown on agar were significantly more sensitive to all three biocides than cells grown in broth. The differences in antimicrobial activity were greater in the case of S. aureus than in the case of P. aeruginosa. With S. aureus cultures, differences in the reduction factor of up to 5 log steps were found, with P. aeruginosa up to 2.5 log steps. The results of our uptake tests performed with S. aureus and octenidine dihydrochloride indicated that the growth conditions and the associated different stress factors either had an influence on the composition of the cell surface of this test organism or induced the formation of an efflux system. Cells of S. aureus cultured in broth took up only one-fifth of the amount of biocide molecules compared to cells from agar cultures. These data correlated with the results of the suspension tests. A low uptake of biocides apparently led to a reduced killing rate. In contrast to S. aureus, no significant differences in the uptake of octenidine dihydrochloride by cells of P. aeruginosa could be observed. These cells took up the same amount of the antimicrobial substance, whether on agar or in broth. In view of these results, possible consequences should be considered prior to changing test regulations.

Genomic and transcriptomic insights into how bacteria withstand high concentrations of benzalkonium chloride biocides.

PubMed

Kim, Minjae; Hatt, Janet K; Weigand, Michael R; Krishnan, Raj; Pavlostathis, Spyros G; Konstantinidis, Konstantinos T

2018-04-13

Benzalkonium chlorides (BAC) are commonly used biocides in broad-spectrum disinfectant solutions. How microorganisms cope with BAC exposure remains poorly understood, despite its importance for disinfection and disinfectant-induced antibiotic resistance. To provide insights into these issues, we exposed two isolates of an opportunistic pathogen, Pseudomonas aeruginosa , to increasing concentrations of BAC. One isolate was pre-adapted to BAC as it originated from a bioreactor fed with sub-inhibitory concentrations of BAC for 3 years, while the other originated from a bioreactor that received no BAC. Replicated populations of both isolates were able to survive high concentrations of BAC, up to 1200 and 1600mg/L for the non- and pre-adapted ones, respectively, exceeding typical application doses. RNA-seq analysis revealed up-regulation of efflux pump genes and decreased expression of porins related to BAC transport as well as reduced growth rate. Increased expression of spermidine (a polycation) synthase genes and mutations in the pmrB (polymyxin resistance) gene, which cause a reduction in membrane negative charge, suggested that a major adaptation to exposure to the cationic surfactant BAC was to actively stabilize cell surface charge. Collectively, these results revealed that P. aeruginosa adapts to BAC exposure by a combination of mechanisms, and provided genetic markers to monitor BAC-resistant organisms that may have applications in the practice of disinfection. Importance Benzalkonium chlorides (BAC) are widely used as biocides in disinfectant solutions, food processing lines, domestic households, and healthcare facilities. Due to their wide use and mode of action, there has been rising concern that BAC may promote antibiotic resistance. Consistently, at least 40 outbreaks have been attributed to infection by disinfectant- and antibiotic-resistant pathogens such as Pseudomonas aeruginosa However, the underlying molecular mechanisms that bacteria deal with BAC exposure remain poorly elucidated. Elucidating these mechanisms may be important for monitoring and limiting the spreading of disinfectant-resistant pathogens. Using an integrated approach that combined genomics and transcriptomics with physiological characterization of BAC-adapted isolates, this study provided a comprehensive understanding of the BAC-resistance mechanisms in P. aeruginosa Our findings also revealed potential genetic markers to detect and monitor the abundance of BAC-resistant pathogens across clinical or environmental settings. Copyright © 2018 American Society for Microbiology.

Research and Development of Wound Dressing in Maxillofacial Trauma.

DTIC Science & Technology

1983-03-14

Lidocaine 7 Table 4 PVP-1 2 (BASF 17/12) Microcapsule Size Distribution 8 Table 5 Processing Summary of PVP-1 2 (BASF 17/12) Microencapsulation 9 Table...benzalkonium chloride (Maquat LC-12S) was also incorporated into fabrics and powders. The povidone iodine (BASF 17/12) was microencapsulated using the... microcapsules con- taining povidone iodine. At 30% polymer, 70% of the product was between :- 212-600 microns. This material gave in vitro release of

Improved High-Quality Draft Genome Sequence and Annotation of Burkholderia contaminans LMG 23361T.

PubMed

Jung, Ji Young; Ahn, Youngbeom; Kweon, Ohgew; LiPuma, John J; Hussong, David; Marasa, Bernard S; Cerniglia, Carl E

2017-04-20

Burkholderia contaminans LMG 23361 is the type strain of the species isolated from the milk of a dairy sheep with mastitis. Some pharmaceutical products contain disinfectants such as benzalkonium chloride (BZK) and previously we reported that B. contaminans LMG 23361 T possesses the ability to inactivate BZK with high biodegradation rates. Here, we report an improved high-quality draft genome sequence of this strain. Copyright © 2017 Jung et al.

Intensity and duration of in-vitro antibacterial activity of different adhesives used in orthodontics.

PubMed

Passariello, Claudio; Sannino, Gianpaolo; Petti, Stefano; Gigola, Pierangelo

2014-04-01

This work investigated the antibacterial activity of 14 bonding agents to predict their ability to inhibit white-spot development during orthodontic treatment. Standardized, sterilized disks of each material were continuously rinsed (for up to 180 d) in a flow of sterile saline. At predetermined time points, the residual ability of each material to inhibit bacterial growth (determined by measuring the size of inhibition halos around disks placed onto appropriate culture media seeded with Streptococcus gordonii DSM6777, Streptococcus sanguinis DSM20567, Streptococcus mutans DSM20523, or Lactobacillus acidophilus DSM20079) and biofilm formation (determined by measuring the numbers of bacteria adherent to disks following incubation in appropriate broths) was tested in triplicate and compared with the baseline activities of freshly prepared materials. Overall antibacterial and anti-biofilm activities, adjusted for exposure time and strain of bacteria, were assessed. The decrease of antibacterial activity was faster (30-60 d) and complete for fluoride-enriched materials, but slower (90 d) and partial for antimicrobial-containing materials (benzalkonium chloride, zinc oxide, chlorexidine, or MDPB). Materials enriched with benzalkonium chloride, chlorexidine, or MDPB showed the highest antibacterial activities. Anti-biofilm assays yielded similar results. These data could be helpful for clinicians in the choice of the best performing bonding agent also in light of duration of the clinical application. © 2014 Eur J Oral Sci.

Ultrasound improves antimicrobial effect of sodium dichloroisocyanurate to reduce Salmonella Typhimurium on purple cabbage.

PubMed

Duarte, Ana Lúcia Almeida; do Rosário, Denes Kaic Alves; Oliveira, Syllas Borburema Silva; de Souza, Hygor Lendell Silva; de Carvalho, Raquel Vieira; Carneiro, Joel Camilo Souza; Silva, Pollyanna Ibrahim; Bernardes, Patrícia Campos

2018-03-23

The consumer's interest in ready-to-eat, fast-ready, nutritious and fresh foods is a major challenge for the food industry. Thus, studies on new sanitization methods are relevant. The effect of Sodium Hypochlorite (SH), Benzalkonium Chloride (BC), and Sodium Dichloroisocyanurate (SD) isolated or combined with Ultrasound (US) in purple cabbage quality over 7 days of storage at 8 ± 1 °C was evaluated. The natural microbiota (mesophilic aerobic bacteria, lactic acid bacteria and coliforms), intentionally inoculated Salmonella Typhimurium, physicochemical quality (anthocyanins, pH, total titratable acidity, instrumental color and mass loss) and sensorial quality (multiple comparison test and visual sensory acceptance) were analyzed. The best treatments for natural microbiota reduction were BC and US + BC, which in general reduced between 1.9 and 3.2 log cfu/g. US improved (p < .05) the effect of SD reducing almost 4 log cycles in the population of S. Typhimurium adhered to cabbage. The treatments with benzalkonium chloride resulted in important physicochemical changes in cabbage. The treatments SD and US + SD did not alter the physicochemical and sensorial characteristics of purple cabbage. Therefore, ultrasound combined with sodium dichloroisocyanurate is a promising alternative for the reduction of microbiological contaminants of purple cabbage without physicochemical, sensory and anthocyanin content loss. Copyright © 2018 Elsevier B.V. All rights reserved.

Benzalkonium chloride accelerates the formation of the amyloid fibrils of corneal dystrophy-associated peptides.

PubMed

Kato, Yusuke; Yagi, Hisashi; Kaji, Yuichi; Oshika, Tetsuro; Goto, Yuji

2013-08-30

Corneal dystrophies are genetic disorders resulting in progressive corneal clouding due to the deposition of amyloid fibrils derived from keratoepithelin, also called transforming growth factor β-induced protein (TGFBI). The formation of amyloid fibrils is often accelerated by surfactants such as sodium dodecyl sulfate (SDS). Most eye drops contain benzalkonium chloride (BAC), a cationic surfactant, as a preservative substance. In the present study, we aimed to reveal the role of BAC in the amyloid fibrillation of keratoepithelin-derived peptides in vitro. We used three types of 22-residue synthetic peptides covering Leu110-Glu131 of the keratoepithelin sequence: an R-type peptide with wild-type R124, a C-type peptide with C124 associated with lattice corneal dystrophy type I, and a H-type peptide with H124 associated with granular corneal dystrophy type II. The time courses of spontaneous amyloid fibrillation and seed-dependent fibril elongation were monitored in the presence of various concentrations of BAC or SDS using thioflavin T fluorescence. BAC and SDS accelerated the fibrillation of all synthetic peptides in the absence and presence of seeds. Optimal acceleration occurred near the CMC, which suggests that the unstable and dynamic interactions of keratoepithelin peptides with amphipathic surfactants led to the formation of fibrils. These results suggest that eye drops containing BAC may deteriorate corneal dystrophies and that those without BAC are preferred especially for patients with corneal dystrophies.

Conjunctival and corneal reactions in rabbits following short- and repeated exposure to preservative-free tafluprost, commercially available latanoprost and 0.02% benzalkonium chloride

PubMed Central

Liang, H; Baudouin, C; Pauly, A; Brignole-Baudouin, F

2008-01-01

Aim: To compare the conjunctival and corneal reactions of commercially available solution of latanoprost (Xalatan) and preservative-free (PF) tafluprost in rabbits. Methods: The rabbits received 50 μl of phosphate-buffered saline (PBS), PF-tafluprost 0.0015%, latanoprost 0.005% or benzalkonium chloride (BAK) 0.02%; all solutions were applied at 5 min intervals for a total of 15 times. The ocular surface toxicity was investigated using slit-lamp biomicroscopy examination, flow cytometry (FCM) and on imprints for CD45 and tumour necrosis factor-receptor 1 (TNFR1) conjunctival impression cytology (CIC) and corneal in vivo confocal microscopy (IVCM). Standard immunohistology also assessed inflammatory/apoptotic cells. Results: Clinical observation and IVCM images showed the highest ocular surface toxicity with latanoprost and BAK, while PF-tafluprost and PBS eyes presented almost normal corneoconjunctival aspects. FCM showed a higher expression of CD45+ and TNFR1+ in latanoprost- or BAK-instilled groups, compared with PF-tafluprost and PBS groups. Latanoprost induced fewer positive cells for inflammatory marker expressions in CIC specimens compared with BAK-alone, both of which were higher than with PF-tafluprost or PBS. Immunohistology showed the same tendency of toxic ranking. Conclusion: The authors confirm that rabbit corneoconjunctival surfaces presented a better tolerance when treated with PF-tafluprost compared with commercially available latanoprost or BAK solution. PMID:18723745

Accelerated solvent extraction followed by on-line solid-phase extraction coupled to ion trap LC/MS/MS for analysis of benzalkonium chlorides in sediment samples

USGS Publications Warehouse

Ferrer, I.; Furlong, E.T.

2002-01-01

Benzalkonium chlorides (BACs) were successfully extracted from sediment samples using a new methodology based on accelerated solvent extraction (ASE) followed by an on-line cleanup step. The BACs were detected by liquid chromatography/ion trap mass spectrometry (LC/MS) or tandem mass spectrometry (MS/MS) using an electrospray interface operated in the positive ion mode. This methodology combines the high efficiency of extraction provided by a pressurized fluid and the high sensitivity offered by the ion trap MS/MS. The effects of solvent type and ASE operational variables, such as temperature and pressure, were evaluated. After optimization, a mixture of acetonitrile/water (6:4 or 7:3) was found to be most efficient for extracting BACs from the sediment samples. Extraction recoveries ranged from 95 to 105% for C12 and C14 homologues, respectively. Total method recoveries from fortified sediment samples, using a cleanup step followed by ASE, were 85% for C12BAC and 79% for C14-BAC. The methodology developed in this work provides detection limits in the subnanogram per gram range. Concentrations of BAC homologues ranged from 22 to 206 ??g/kg in sediment samples from different river sites downstream from wastewater treatment plants. The high affinity of BACs for soil suggests that BACs preferentially concentrate in sediment rather than in water.

Topical application of benzalkonium chloride to the stomach serosa increases gastric emptying time, acid secretion, serum gastrin and size of the mucosa.

PubMed

Zucoloto, S; Romanello, L M F; Garcia, S B; Sobreira, L F R; Barbosa, A J A; Troncon, L E A

2002-11-01

In the present study we evaluated the effects of gastric myenteric denervation using benzalkonium chloride (BAC) on the time for gastric emptying, as well as gastric secretion, and mucosal epithelial cell size and population in rats. Wistar rats were treated with topical serosal application of BAC to the stomach. Control animals received saline. Ninety days after surgery, gastric emptying time, gastric acid secretion and serum gastrin levels were studied. Next, the animals were sacrificed and the stomachs were removed, fixed in formalin and histologically processed for histomorphometry of the height, area and volume of the glandular portion, and volume and population of mucous, chief, parietal, G- and labelled cells. BAC animals showed a significant delay in gastric emptying and an increase in gastric acid secretion and serum gastrin levels. These animals also presented a significant reduction of myenteric neuron number, hypertrophy of parietal and chief cells, hyperplasia of G cells and an increase in the gastric mucosa area. The absence of the myenteric plexus seems to protect the stomach from the hyperplastic effects of hypergastrinemia. Gastric food stasis may act as a factor triggering morphological and functional alterations of the gastric epithelium. Although gastric food stasis is a common finding in medical practice, its physiopathological consequences are poorly understood and have not been frequently discussed in the literature.

Is the use of benzalkonium chloride as a preservative for nasal formulations a safety concern? A cautionary note based on compromised mucociliary transport.

PubMed

Bernstein, I L

2000-01-01

Topical nasal solution and suspension delivery systems are available for short- and long-acting vasoconstrictors, ipratropium, cromolyn, azelastine, and glucocorticosteroids. The use of intranasal glucocorticosteroids has increased substantially because the efficacy of these agents has been well established for the treatment of perennial and seasonal allergic rhinitis. Adverse local effects of burning, irritation, and dryness are occasionally associated with glucocorticosteroid nasal preparations. Benzalkonium chloride (BKC) is a quaternary ammonium antimicrobial agent included in some nasal solutions (including glucocorticosteroids) to prevent the growth of bacteria. Some reports suggest that BKC in nasal sprays may cause adverse effects, including reduced mucociliary transport, rhinitis medicamentosa, and neutrophil dysfunction. This article summarizes recent literature about possible adverse biologic effects associated with BKC as a nasal spray preservative by examining its effects on the following properties of mucociliary transport: ciliary motion, ciliary form, ciliary beat frequency, electron microscopy, and particle movement/saccharin clearance tests. Both animal and human in vitro data suggest that BKC promotes ciliostasis and reduction in mucociliary transport that may be partially masked by absorption and dilution effects occurring in respiratory mucus. These possible confounding factors may account for several disparate human in vivo results. The use of BKC-free glucocorticosteroid formulations should be considered, particularly in patients who complain of nasal burning, dryness, or irritation.

Cell viability score as an integrated indicator for cytotoxicity of benzalkonium chloride-containing antiglaucoma eyedrops.

PubMed

Ayaki, Masahiko; Iwasawa, Atsuo; Niwano, Yoshimi

2012-01-01

We evaluated the in vitro cytotoxicity of benzalkonium chloride (BAK)-containing antiglaucoma eyedrops. We prepared cell cultures of SIRC, BCE C/D-1b, RC-1, and Chang conjunctiva. The viability of cell cultures was determined using the MTT and neutral red assays. The cell viability score (CVS) was used to compare the toxicity of test solutions. %CVS50 and %CVS40/80 of each eyedrop solution were 71 and 26 for Lumigan(®) (0.002% bimatoprost with 0.005% BAK), 100 and 99 for Tapros(®) (0.0015% tafluprost, a new formula from 2010 with 0.001% BAK), 39 and -29 for 2% Trusopt(®) (2% dorzolamide with 0.0075% BAK), 28 and -43 for Xalacom(®) (latanoprost/0.5% timolol with 0.02% BAK), 88 and 66 for DuoTrav(®) (travoprost/0.5% timolol with no BAK), 36 and -35 for Cosopt(®) (2% dorzolamide/0.5% timolol with 0.0075% BAK) and 53 and -1 for Combigan(®) (0.15% brimonidin/0.5% timolol with 0.005% BAK). Only Xalacom(®) and Tapros(®) did not show an apparent decrease in %CVS as compared to the corresponding concentration of BAK. In conclusion, the cytotoxicity of tested eyedrops was dependent on BAK. Only the eyedrops containing latanoprost or tafluprost showed a reduction in the cytotoxicity of BAK.

Changes in Ocular Surface Characteristics after Switching from Benzalkonium Chloride-Preserved Latanoprost to Preservative-Free Tafluprost or Benzalkonium Chloride-Preserved Tafluprost.

PubMed

Tokuda, Naoto; Kitaoka, Yasushi; Matsuzawa, Akiko; Tsukamoto, Ayaka; Sase, Kana; Sakae, Shinsuke; Takagi, Hitoshi

2017-01-01

The aim of the present study was to examine the effects of switching from Latanoprost ophthalmic solution containing a preservative to preservative-free Tafluprost ophthalmic solution or Tafluprost containing a preservative on ocular surfaces. Forty patients (40 eyes) with glaucoma (mean age: 62.0 ± 10.9 years) using Latanoprost with preservative for six months or longer were assigned either to a Tafluprost-containing-preservative group (20 eyes) or preservative-free-Tafluprost group (20 eyes). The intraocular pressure, corneal epithelial barrier function (fluorescein uptake concentration with fluorophotometer FL-500), superficial punctate keratopathy (AD classification), and tear film breakup time (TBUT) were assessed before switching and at 12 weeks after switching. No significant differences in intraocular pressure were noted after switching in either group. Corneal epithelial barrier function was improved significantly after switching in both the Tafluprost-containing-preservative and the preservative-free-Tafluprost groups. There were no significant differences in AD scores after switching in the Tafluprost-containing-preservative group, but significant improvements were noted in the preservative-free-Tafluprost group. No significant differences in TBUT were noted in the Tafluprost-containing-preservative or preservative-free-Tafluprost groups after switching. After switching from preservative Latanoprost to Tafluprost containing-preservative or preservative-free Tafluprost, corneal epithelial barrier function was improved while the intraocular pressure reduction was retained.

The effectiveness of a single-stage versus traditional three-staged protocol of hospital disinfection at eradicating vancomycin-resistant Enterococci from frequently touched surfaces.

PubMed

Friedman, N Deborah; Walton, Aaron L; Boyd, Sarah; Tremonti, Christopher; Low, Jillian; Styles, Kaylene; Harris, Owen; Alfredson, David; Athan, Eugene

2013-03-01

Environmental contamination is a reservoir for vancomycin-resistant enterococcus (VRE) in hospitals. Environmental sampling of surfaces was undertaken anytime before disinfection and 1 hour after disinfection utilizing a sodium dichloroisocyanurate-based, 3-staged protocol (phase 1) or benzalkonium chloride-based, single-stage clean (phase 2). VRE colonization and infection rates are presented from 2010 to 2011, and audits of cleaning completeness were also analyzed. Environmental samples collected before disinfection were significantly more likely to be contaminated with VRE during phase 1 than phase 2: 25.2% versus 4.6%, respectively; odds ratio (OR), 7.01 (P < .01). Environmental samples collected after disinfection were also significantly more likely to yield VRE during phase 1 compared with phase 2: 11.2% versus 1.1%, respectively; OR, 11.73 (P < .01). Rates of VRE colonization were higher during 2010 than 2011. Cleaning audits showed similar results over both time periods. During use of a chlorine-based, 3-staged protocol, significantly higher residual levels of VRE contamination were identified, compared with levels detected during use of a benzalkonium chloride-based product for disinfection. This reduction in VRE may be due to a new disinfection product, more attention to the thoroughness of cleaning, or other supplementary efforts in our institution. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Efflux pump-mediated benzalkonium chloride resistance in Listeria monocytogenes isolated from retail food.

PubMed

Jiang, Xiaobing; Yu, Tao; Liang, Yu; Ji, Shengdong; Guo, Xiaowei; Ma, Jianmin; Zhou, Lijun

2016-01-18

In this study, efflux pump-mediated benzalkonium chloride (BC) resistance, including plasmid-encoded (Qac protein family and BcrABC) and chromosome-borne efflux pumps, was investigated in Listeria monocytogenes from retail food in China. Among the 59 L. monocytogenes strains, 13 (22.0%) strains were resistant to BC. The PCR results showed that bcrABC was harbored by 2 of 13 BC resistant strains. However, none of the qac genes were detected among the 59 strains. The bcrABC was absent in both of the plasmid cured strains, indicating that this BC resistance determinant was plasmid-encoded in the two bcrABC-positive strains. In the presence of reserpine, most of the bcrABC-negative strains had decreases in the MICs of BC, suggesting the existence of other efflux pumps and their role in BC resistance. After exposed to reserpine, the reduction in BC MICs was observed in the two cured strains, indicating that efflux pumps located on chromosome was also involved in BC resistance. Our findings suggest that food products may act as reservoirs for BC resistant isolates of L. monocytogenes and plasmid- and chromosome-encoded efflux pumps could mediate the BC resistance of L. monocytogenes, which is especially relevant to the adaption of this organism in food-related environments with frequent BC use. Copyright © 2015 Elsevier B.V. All rights reserved.

Transformation of benzalkonium chloride under nitrate reducing conditions.

PubMed

Tezel, Ulas; Pavlostathis, Spyros G

2009-03-01

The effect and transformation potential of benzalkonium chlorides (BAC) under nitrate reducing conditions were investigated at concentrations up to 100 mg/L in batch assays using a mixed, mesophilic (35 degrees C) methanogenic culture. Glucose was used as the carbon and energy source and the initial nitrate concentration was 70 mg N/L Dissimilatory nitrate reduction to ammonia (DNRA) and to dinitrogen (DNRN) were observed at BAC concentrations up to 25 mg/L At and above 50 mg BAC/L, DNRA was inhibited and DNRN was incomplete resulting in accumulation of nitrous oxide. Long-term inhibition of methanogenesis and accumulation of volatile fatty acids were observed at and above 50 mg BAC/L Over 99% of the added BAC was recovered from all cultures except the one amended with 100 mg BAC/L where 37% of the initially added BAC was transformed during the 100 day incubation period. Abiotic and biotic assays performed with 100 mg/L of BAC and 5 mM (in the liquid phase) of either nitrate, nitrite, or nitric oxide demonstrated that BAC transformation was abiotic and followed the modified Hofmann degradation pathway, i.e., bimolecular nucleophilic substitution with nitrite. Alkyl dimethyl amines (tertiary amines) were produced at equamolar levels to BAC transformed, but were not further degraded. This is the first report demonstrating the transformation of BAC under nitrate reducing conditions and elucidating the BAC transformation pathway.

Antimicrobial effects of electrolytic products of sodium chloride--comparative evaluation with sodium hypochlorite solution and efficacy in handwashing.

PubMed

Hitomi, S; Baba, S; Yano, H; Morisawa, Y; Kimura, S

1998-11-01

We examined the in vitro bactericidal effects and efficacy on handwashing of water containing electrolytic products of sodium chloride (electrolytic water). The electrolytic water, whose pH and concentration of free residual chlorine were 6.7-6.9 and 20-22 ppm, respectively, showed equal reduction of both Staphylococcus aureus and Escherichia coli to dilution of commercially available sodium hypochlorite containing 60 ppm of free residual chlorine. This bactericidal effect was calculated to be due to hypochlorous acid, based on the pH and the amount of chlorine in solution. Handwashing with the electrolytic water reduced the numbers of S. aureus on hands by 1/10(2), while running water and 0.2% benzalkonium chloride with 80% ethanol gave a 1/10 and 1/10(5) reduction, respectively. We conclude that electrolytic water might be applicable for handwashing in place of running water.

[Survey of synthetic disinfectants in grapefruit seed extract and its compounded products].

PubMed

Sugimoto, Naoki; Tada, Atsuko; Kuroyanagi, Masanori; Yoneda, Yuko; Yun, Young Sook; Kunugi, Akira; Sato, Kyoko; Yamazaki, Takeshi; Tanamoto, Ken-Ichi

2008-02-01

Grapefruit seed extract (GSE), derived from the seeds of grapefruit (Citrus paradisi MCAF.), is listed as a natural food additive in Japan. Products containing GSE are used as disinfectants made from only natural sources, especially after Japanese researchers found that GSE prevents the growth of norovirus. On the other hand, recent overseas studies indicated that synthetic disinfectants, such as benzalkonium and benzethonium chlorides, were present in some commercial GSE products. To confirm the quality of commercial GSE products available in Japanese markets, we carried out comprehensive research to identify the major constituents of commercial GSE products which are used as food additives (13 products from 6 manufacturers), dietary supplements (5 products from 4 manufacturers), cosmetic materials (16 products from 10 manufacturers) and disinfectant or deodorant sprays (7 products from 7 manufacturers). By means of NMR and LC/MS analysis, synthetic disinfectants such as benzethonium or benzalkonium salts were detected in most of the commercial GSE products.

Inhibition of orally produced volatile sulfur compounds by zinc, chlorhexidine or cetylpyridinium chloride--effect of concentration.

PubMed

Young, Alix; Jonski, Grazyna; Rölla, Gunnar

2003-10-01

Zinc ions, chlorhexidine (CHX) and cetylpyridinium chloride (CPC) are all known to inhibit production of volatile sulfur compounds (VSCs). The objective was to examine the anti-VSC dose-response effects of each of the above agents. Oral malodor was induced in 13 test subjects using the cysteine challenge method. The oral VSC response to rinses with 6 mm l-cysteine (pH 7.2) before and 1, 2 and 3 h after rinsing with zinc ions (Zn2+: 0.1, 0.3 and 1.0%), CHX and CPC (0.025 and 0.2%) was measured. Mouth air was analysed for VSC by gas chromatography (GC) according to current methodology. Zinc had a marked dose- and time-dependent anti-VSC effect. Zinc at 1% concentration had a somewhat unpleasant taste, whereas the lowest concentration was found acceptable. Chlorhexidine maintained a moderate anti-VSC effect over time. At 3 h, 0.2% CHX was the most effective agent but tasted relatively unpleasant. Cetylpyridinium at a concentration of 0.2% was only marginally more effective than 0.025% CHX over the 3 h, while 0.025% CPC had no better anti-VSC effect than water at both 2 h and 3 h. It was concluded that the three test agents demonstrated different anti-VSC kinetics. Although Zn had the best anti-VSC effect at 1 h, 0.2% CHX was at least as effective as 1% Zn at 3 h, most likely as a result of its unique substantivity.

Acute Mountain Sickness at 4500 m is not Altered by Repeated Eight-Hour Exposures to 3200-3550 m Normobaric Hypoxic Equivalent,

DTIC Science & Technology

1987-09-10

subject had his own numbered device, which was disassembled, washed and disinfected ( benzalkonium chloride , 1:1000 v/v) each evening. 4 Subjects...fluctuations throughout the 10-day period after the reduction in altitude equivalent which occurred during day I, either in the group mean values (shown) or...significant reduction in hemoglobin concentration in the control group over the sea level treatment period, with a concomitant, but non-significant

Homologs of the Acinetobacter baumannii AceI transporter represent a new family of bacterial multidrug efflux systems.

PubMed

Hassan, Karl A; Liu, Qi; Henderson, Peter J F; Paulsen, Ian T

2015-02-10

Multidrug efflux systems are a major cause of resistance to antimicrobials in bacteria, including those pathogenic to humans, animals, and plants. These proteins are ubiquitous in these pathogens, and five families of bacterial multidrug efflux systems have been identified to date. By using transcriptomic and biochemical analyses, we recently identified the novel AceI (Acinetobacter chlorhexidine efflux) protein from Acinetobacter baumannii that conferred resistance to the biocide chlorhexidine, via an active efflux mechanism. Proteins homologous to AceI are encoded in the genomes of many other bacterial species and are particularly prominent within proteobacterial lineages. In this study, we expressed 23 homologs of AceI and examined their resistance and/or transport profiles. MIC analyses demonstrated that, like AceI, many of the homologs conferred resistance to chlorhexidine. Many of the AceI homologs conferred resistance to additional biocides, including benzalkonium, dequalinium, proflavine, and acriflavine. We conducted fluorimetric transport assays using the AceI homolog from Vibrio parahaemolyticus and confirmed that resistance to both proflavine and acriflavine was mediated by an active efflux mechanism. These results show that this group of AceI homologs represent a new family of bacterial multidrug efflux pumps, which we have designated the proteobacterial antimicrobial compound efflux (PACE) family of transport proteins. Bacterial multidrug efflux pumps are an important class of resistance determinants that can be found in every bacterial genome sequenced to date. These transport proteins have important protective functions for the bacterial cell but are a significant problem in the clinical setting, since a single efflux system can mediate resistance to many structurally and mechanistically diverse antibiotics and biocides. In this study, we demonstrate that proteins related to the Acinetobacter baumannii AceI transporter are a new class of multidrug efflux systems which are very common in Proteobacteria: the proteobacterial antimicrobial compound efflux (PACE) family. This is the first new family of multidrug efflux pumps to be described in 15 years. Copyright © 2015 Hassan et al.

Decrease in corneal damage due to benzalkonium chloride by the addition of sericin into timolol maleate eye drops.

PubMed

Nagai, Noriaki; Ito, Yoshimasa; Okamoto, Norio; Shimomura, Yoshikazu

2013-01-01

We investigated the protective effects of sericin on corneal damage due to benzalkonium chloride (BAC) used as a preservative in commercially available timolol maleate eye drops using rat debrided corneal epithelium and a human cornea epithelial cell line (HCE-T). Corneal wounds were monitored using a fundus camera TRC-50X equipped with a digital camera; eye drops were instilled into the rat eyes five times a day after corneal epithelial abrasion. The viability of HCE-T cells was calculated by TetraColor One; and Escherichia coli (ATCC 8739) were used to measure antimicrobial activity. The reducing effects on transcorneal penetration and intraocular pressure (IOP) of the eye drops were determined using rabbits. The corneal wound healing rate and rate constants (kH) as well as cell viability were higher following treatment with 0.005% BAC solution containing 0.1% sericin than in the case of treatment with BAC solution alone; the antimicrobial activity was approximately the same for BAC solutions with and without sericin. In addition, the kH for rat eyes instilled with commercially available timolol maleate eye drops containing 0.1% sericin was significantly higher than that of eyes instilled with timolol maleate eye drops without sericin, and the addition of sericin did not affect the corneal penetration or IOP reducing effect of commercially available timolol maleate eye drops. A preservative system comprising BAC and sericin may provide effective therapy for glaucoma patients requiring long-term anti-glaucoma agents.

In vitro inactivation of Chlamydia trachomatis and of a panel of DNA (HSV-2, CMV, adenovirus, BK virus) and RNA (RSV, enterovirus) viruses by the spermicide benzalkonium chloride.

PubMed

Bélec, L; Tevi-Benissan, C; Bianchi, A; Cotigny, S; Beumont-Mauviel, M; Si-Mohamed, A; Malkin, J E

2000-11-01

Kinetics of inactivation by the detergent spermicide benzalkonium chloride (BZK) of Chlamydia trachomatis and of a panel of DNA viruses [herpes simplex virus hominis type 2 (HSV-2), cytomegalovirus (CMV), adenovirus (ADV) and BK virus (BKV)] and RNA [respiratory syncytial virus (RSV) and enterovirus (ENV)] were established in accordance with a standardized in vitro protocol. After a 5 min incubation, inactivation of >95% of HSV-2 and CMV was obtained at a concentration of 0.0025% (w/v) (25 Ig/L); concentrations as low as 0.0005%, 0.0050% and 0.0125%, induced a 3.0 log10 reduction in infectivity of HSV-2 and CMV, RSV and ADV, respectively. After a 60 min incubation, concentrations of 0.0125% and 0.050% provided a 3.0 log10 reduction in infectivity of ENV and BKV, respectively. These features indicate that sensitivity to BZK was very high (HSV-2 and CMV) or high (RSV) for enveloped viruses, intermediate (ADV) or low (ENV and BKV) for non-enveloped viruses. Furthermore, BZK had marked antichlamydial activity, showing >99% killing after only a 1 min incubation at a concentration of 0.00125%. BZK demonstrates potent in vitro activity against the majority of microorganisms causing sexually transmitted infectious diseases, including those acting as major genital cofactors of human immunodeficiency virus transmission. These attributes qualify BZK as a particularly attractive candidate for microbicide development.

Weakening effect of cell permeabilizers on gram-negative bacteria causing biodeterioration.

PubMed

Alakomi, H-L; Paananen, A; Suihko, M-L; Helander, I M; Saarela, M

2006-07-01

Gram-negative bacteria play an important role in the formation and stabilization of biofilm structures on stone surfaces. Therefore, the control of growth of gram-negative bacteria offers a way to diminish biodeterioration of stone materials. The effect of potential permeabilizers on the outer membrane (OM) properties of gram-negative bacteria was investigated and further characterized. In addition, efficacy of the agents in enhancing the activity of a biocide (benzalkonium chloride) was assessed. EDTA, polyethylenimine (PEI), and succimer (meso-2,3-dimercaptosuccinic) were shown to be efficient permeabilizers of the members of Pseudomonas and Stenotrophomonas genera, as indicated by an increase in the uptake of a hydrophobic probe (1-N-phenylnaphthylamine) and sensitization to hydrophobic antibiotics. Visualization of Pseudomonas cells treated with EDTA or PEI by atomic force microscopy revealed damage in the outer membrane structure. PEI especially increased the surface area and bulges of the cells. Topographic images of EDTA-treated cells were compatible with events assigned for the effect of EDTA on outer membranes, i.e., release of lipopolysaccharide and disintegration of OM structure. In addition, the effect of EDTA treatment was visualized in phase-contrast images as large areas with varying hydrophilicity on cell surfaces. In liquid culture tests, EDTA and PEI supplementation enhanced the activity of benzalkonium chloride toward the target strains. Use of permeabilizers in biocide formulations would enable the use of decreased concentrations of the active biocide ingredient, thereby providing environmentally friendlier products.

Distinct Effect of Benzalkonium Chloride on the Esterase and Aryl Acylamidase Activities of Butyrylcholinesterase.

PubMed

Jaganathan; Boopathy

2000-08-01

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) from vertebrates, other than their predominant acylcholine hydrolase (esterase) activity, display a genuine aryl acylamidase activity (AAA) capable of hydrolyzing the synthetic substrate o-nitroacetanilide to o-nitroaniline. This AAA activity is strongly inhibited by classical cholinesterase (ChE) inhibitors. In the present study, benzalkonium chloride (BAC), a cationic detergent widely used as a preservative in pharmaceutical preparations, has been shown to distinctly modulate the esterase and AAA activities of BChEs. The detergent BAC was able to inhibit the esterase activity of human serum and horse serum BChEs and AChEs from electric eel and human erythrocyte. The remarkable property of BAC was its ability to profoundly activate the AAA activity of human serum and horse serum BChEs but not the AAA activity of AChEs. Thus BAC seem to preferentially activate the AAA activity of BChEs alone. Results of the study using the ChE active site-specific inhibitor diisopropyl phosphorofluoridate indicated that BAC binds to the active site of ChEs. Furthermore, studies using a structural homolog of BAC indicated that the alkyl group of BAC is essential not only for its interaction with ChEs but also for its distinct effect on the esterase and AAA activities of BChEs. This is the first report of a compound that inhibits the esterase activity, while simultaneously activating the AAA activity, of BChEs. Copyright 2000 Academic Press.

Mechanism and toxicity research of benzalkonium chloride oxidation in aqueous solution by H2O2/Fe(2+) process.

PubMed

Zhang, Qian; Xia, Yu-Feng; Hong, Jun-Ming

2016-09-01

As widely used disinfectants, the pollution caused by benzalkonium chloride (BAC) has attracted a lot of attention in recent years. Since it is not suitable for biodegradation, BAC was degraded firstly by Fenton advanced oxidation technologies (AOTs) in this research to enhance the biodegradability of the pollutions. The result revealed that the optimal molar ratio of H2O2/Fe(2+) for BAC degradation was 10:1, and the COD removal rate was 32 %. To clarify the pathway of degradation, the technique of GC-MS was implemented herein to identify intermediates and the toxicity of those BAC intermediates were also novelty tested through microbial fuel cells (MFC). The findings indicated that ten transformation products including benzyl dimethyl amine and dodecane were formed during the H2O2/Fe(2+) processes, which means the degradation pathway of BAC was initiated both on the hydrophobic (alkyl chain) and hydrophilic (benzyl and ammonium moiety) region of the surfactant. The toxicity of BAC before and after treated by Fenton process was monitored through MFC system. The electricity generation was improved 337 % after BAC was treated by H2O2/Fe(2+) oxidation processes which indicated that the toxicity of those intermediates were much lower than BAC. The mechanism and toxicity research in this paper could provide the in-depth understanding to the pathway of BAC degradation and proved the possibility of AOTs for the pretreatment of a biodegradation process.

Benzalkonium Chloride Accelerates the Formation of the Amyloid Fibrils of Corneal Dystrophy-associated Peptides*

PubMed Central

Kato, Yusuke; Yagi, Hisashi; Kaji, Yuichi; Oshika, Tetsuro; Goto, Yuji

2013-01-01

Corneal dystrophies are genetic disorders resulting in progressive corneal clouding due to the deposition of amyloid fibrils derived from keratoepithelin, also called transforming growth factor β-induced protein (TGFBI). The formation of amyloid fibrils is often accelerated by surfactants such as sodium dodecyl sulfate (SDS). Most eye drops contain benzalkonium chloride (BAC), a cationic surfactant, as a preservative substance. In the present study, we aimed to reveal the role of BAC in the amyloid fibrillation of keratoepithelin-derived peptides in vitro. We used three types of 22-residue synthetic peptides covering Leu110-Glu131 of the keratoepithelin sequence: an R-type peptide with wild-type R124, a C-type peptide with C124 associated with lattice corneal dystrophy type I, and a H-type peptide with H124 associated with granular corneal dystrophy type II. The time courses of spontaneous amyloid fibrillation and seed-dependent fibril elongation were monitored in the presence of various concentrations of BAC or SDS using thioflavin T fluorescence. BAC and SDS accelerated the fibrillation of all synthetic peptides in the absence and presence of seeds. Optimal acceleration occurred near the CMC, which suggests that the unstable and dynamic interactions of keratoepithelin peptides with amphipathic surfactants led to the formation of fibrils. These results suggest that eye drops containing BAC may deteriorate corneal dystrophies and that those without BAC are preferred especially for patients with corneal dystrophies. PMID:23861389

Antimicrobial efficacy of 0·05% cetylpyridinium chloride mouthrinses.

PubMed

Sreenivasan, P K; Haraszthy, V I; Zambon, J J

2013-01-01

This study evaluated the antimicrobial activity of two commercially available 0·05% cetylpyridinium chloride (CPC) mouthrinses with or without alcohol and examined its antimicrobial activity on oral bacterial species including fresh clinical isolates compared to a chlorhexidine mouthrinse and a control fluoride mouthrinse without CPC. Two different approaches were used to evaluate antimicrobial activity. First, the minimum inhibitory concentration (MIC) was determined for each mouthrinse against a panel of 25 micro-organisms including species associated with dental caries, gingivitis and periodontitis. Second, supragingival dental plaque obtained from 15 adults was incubated with the four mouthrinses to evaluate antimicrobial activity on micro-organisms in oral biofilms. Both CPC mouthrinses exhibited lower MIC's, that is, greater antimicrobial activity, against oral Gram-negative bacteria especially periodontal pathogens and species implicated in halitosis such as Aggregatibacter actinomycemcomitans, Campylobacter rectus, Eikenella corrodens, Porphyromonas gingivalis, Prevotella intermedia and Solobacterium moorei than the control mouthrinse. Ex-vivo tests on supragingival plaque micro-organisms demonstrated significantly greater antimicrobial activity by the CPC mouthrinses (>90% killing, P < 0·001) and the chlorhexidine rinse (>98% killing, P < 0·05) compared to the control fluoride mouthrinse. Whilst the chlorhexidine mouthrinse was most effective, mouthrinses containing 0·05% CPC formulated with or without alcohol demonstrated broad-spectrum antimicrobial activity against both laboratory strains and supragingival plaque bacteria compared to a control mouthrinse without CPC. These in vitro and ex-vivo studies provide a biological rationale for previous clinical studies demonstrating the efficacy of CPC mouthrinses in reducing supragingival plaque and plaque-associated gingivitis. © 2012 The Society for Applied Microbiology.

Fundamental Studies on Ambient Temperature Creep Deformation Behavior of Alpha and Alpha-Beta Titanium Alloys

DTIC Science & Technology

1994-02-15

Solutions [49] A-Etch 25 (mL) Hydrofluoric Acid (HF 50%) 25 Nitric Acid Cone (HN03) 50 Glycerine R-Etch 18.5 gm (17 mL) Benzalkonium Chloride 35 (mL... Reduction Project (0704-0188) Washington, DC 20503. 1. AGENCY USE ONLY (Leave Blank) 2. REPORT DATE 1994 3. REPORT TYPE AND DATES COVERED Final 4...K and a 60% reduction in area was given for all of the alloys. This work was found to be sufficient to recrystallize all of the alloys within 12

Selective removal and inactivation of bacteria by nanoparticle composites prepared by surface modification of montmorillonite with quaternary ammonium compounds.

PubMed

Khalil, Rowaida K S

2013-10-01

The purpose of the present study was to prepare new nanocomposites with antibacterial activities by surface modification of montmorillonite using quaternary ammonium compounds that are widely applied as disinfectants and antiseptics in food-processing environments. The intercalation of four quaternary ammonium compounds namely benzalkonium chloride, cetylpyridinium chloride monohydrate, hexadecyltrimethylammonium bromide, tetraethylammonium chloride hydrate into montmorillonite layers was confirmed by X-ray diffraction. The antibacterial influences of the modified clay variants against important foodborne pathogens differed based on modifiers quantities, microbial cell densities, and length of contact. Elution experiments through 0.1 g of the studied montmorillonite variants indicated that Staphylococcus aureus, Pseudomonas aeroginosa, and Listeria monocytogenes were the most sensitive strains. 1 g of hexadecyltrimethylammonium bromide intercalated montmorillonites demonstrated maximum inactivation of L. monocytogenes populations, with 4.5 log c.f.u./ml units of reduction. In adsorption experiments, 0.1 g of tetraethylammonium chloride hydrate montmorillonite variants significantly reduced the growth of Escherichia coli O157:H7, L. monocytogenes, and S. aureus populations by 5.77, 6.33, and 7.38 log units respectively. Growth of wide variety of microorganisms was strongly inhibited to undetectable levels (

Effectiveness of a Chlorhexidine Digluconate 0.12% and Cetylpyridinium Chloride 0.05% Solution in eliminating Candida albicans Colonizing Dentures: A Randomized Clinical in vivo Study.

PubMed

Aoun, Georges; Cassia, Antoine; Berberi, Antoine

2015-06-01

Effective denture hygiene is important for patients suffering from denture stomatitis (DS). This study aimed to evaluate the efficacy of a solution containing 0.12% chlorhexidine (CHX) digluconate and 0.05% cetylpyridinium chloride (CPC) in eliminating Candida albicans colonizing dentures. Forty denture wearers (11 men, 29 women; age range 40 to 80 years) with clinical evidence of DS were randomly divided into two groups, one test and one control. The dentures of the test group were treated by immersion in a solution of 0.12% CHX and 0.05% CPC while those of the control group were immersed in distilled water. Swabs were collected from the fitting surfaces of the upper dentures prior and post cleaner use and examined mycologically. Reduction in the number of colony-forming units (CFU) of Candida albicans after immersion of the dentures in a solution of 0.12% CHX and 0.05% CPC was significantly greater than that of the control group. A solution of 0.12% CHX and 0.05% CPC tested as a product of disinfection of the acrylic dentures showed significant results after immersion of 8 night hours for 4 days.

UV/chlorine as an advanced oxidation process for the degradation of benzalkonium chloride: Synergistic effect, transformation products and toxicity evaluation.

PubMed

Huang, Nan; Wang, Ting; Wang, Wen-Long; Wu, Qian-Yuan; Li, Ang; Hu, Hong-Ying

2017-05-01

Benzalkonium chlorides (BACs), as typical cationic surfactants and biocides widely applied in household and industrial products, have been frequently detected as micropollutants in many aquatic environments. In this study, the combination of UV irradiation and chlorine (UV/chlorine), a newly interested advanced oxidation process, was used to degrade dodecylbenzyldimethylammonium chloride (DDBAC). UV/chlorine showed synergistic effects on DDBAC degradation comparing to UV irradiation or chlorination alone. Radical quenching experiments indicated that degradation of DDBAC by UV/chlorine involved both UV photolysis and radical species oxidation, which accounted for 48.4% and 51.6%, respectively. Chlorine dosage and pH are essential parameters affecting the treatment efficiency of UV/chlorine. The pseudo first order rate constant (k obs, DDBAC ) increased from 0.046 min -1 to 0.123 min -1 in response to chlorine dosage at 0-150 mg/L, and the degradation percentage of DDBAC within 12 min decreased from 81.4% to 56.6% at pH 3.6-9.5. Five main intermediates were identified and semi-quantified using HPLC-MS/MS and a possible degradation pathway was proposed. The degradation mechanisms of DDBAC by UV/chlorine included cleavage of the benzyl-nitrogen bond and hydrogen abstraction of the alkyl chain. Trichloromethane (TCM), chloral hydrate (CH), trichloropropanone (TCP), dichloropropanone (DCP) and dichloroacetonitrile (DCAN) were detected using GC-ECD. The formation of chlorinated products increased rapidly initially, then decreased (TCM, TCP, DCP and DCAN) or remained stable (CH) with extended treatment. The actual formation of TCM peaked at 30 min (50.3 μg/L), while other chlorinated products did not exceed 10 μg/L throughout the process. Based on the luminescent bacterial assay, DDBAC solution underwent almost complete detoxification subjected to UV/chlorine treatment for 120 min, which is more effective than UV irradiation or chlorination alone. Copyright © 2017 Elsevier Ltd. All rights reserved.

Changes in rabbit corneal innervation induced by the topical application of benzalkonium chloride.

PubMed

Chen, Wensheng; Zhang, Zhenhao; Hu, Jiaoyue; Xie, Hui; Pan, Juxin; Dong, Nuo; Liu, Zuguo

2013-12-01

To investigate the effect of benzalkonium chloride (BAK) on corneal nerves. Fifty-four adult New Zealand Albino rabbits were randomly divided into 3 groups. BAK at concentrations of 0.005%, 0.01%, or 0.02% was applied once daily to 1 eye of each rabbit for 9 days. The contralateral untreated eyes were used as controls. Corneal mechanical sensitivity, aqueous tear production, tear break-up time (BUT), fluorescein, and Rose Bengal staining scores were compared with those of control values on days 3, 6, and 9. Corneal whole mounts were immunostained with a specific antitubulin βIII antibody to label nerve fibers. Epithelial superficial nerve terminal, subbasal, and stromal nerve fiber densities were quantified. The structure of the central cornea was examined by means of in vivo confocal microscopy on day 9. The topical application of BAK resulted in lower corneal sensitivity and higher Rose Bengal staining scores on day 3, whereas there were no significant changes in the BUT, Schirmer, and corneal fluorescein scores. Decreased nerve densities in superficial and subbasal layers were observed in BAK-treated eyes on days 3 and 6, respectively. The eyes treated with 0.02% BAK exhibited significantly reduced Schirmer scores, BUT, and stromal nerve fiber density, and increased fluorescein staining scores on day 9. Corneal superficial epithelial cell size was significantly larger in all BAK-treated eyes compared with that in control eyes. The topical application of BAK can quickly cause corneal hypoesthesia without tear deficiency. Changes in corneal innervation significantly correlate with BAK-induced ocular surface changes.

[Ocular Surface Evaluation in Patients Treated with Prostaglandin Analogues Considering Preservative Agent].

PubMed

Mlčáková, E; Mlčák, P; Karhanová, M; Langová, K; Marešová, K

The aim of this study was to evaluate the ocular surface in patients treated with prostaglandin analogues considering contained preservative agent. 60 patients with glaucoma or ocular hypertension treated with prostaglandin analogue monotherapy were enrolled in this observational study. 20 patients with glaucoma suspect or ocular hypertension without local or systemic glaucoma medication formed the control group. Demographic data and medical history were recorded for each participant. Patients filled in the Ocular surface disease index© (OSDI) questionnaire and underwent an ophthalmological examination including assessment of conjunctival hyperaemia according to Efron, tear film break up time (BUT) and fluorescein staining according to the Oxford grading scheme. Treated participants were divided into 3 groups according to the preservative contained in the currently used prostaglandin analogue: the preservative-free group (18 patients), the polyquaternium group (17 patients) and the benzalkonium chloride (BAK) group (25 patients). The control group had significantly lower fluorescein staining than the preservative-free group (p=0.001), the polyquaternium group (p=0.007) and the BAK group (p=0.002). The conjunctival hyperaemia was significantly lower in the preservative-free group compared to the polyquaternium group (p=0.011). There was no significant difference among the other groups. The difference neither in the OSDI score nor in the BUT was statistically important. This study confirmed that the ocular surface is worse in patients treated with prostaglandin analogue monotherapy than in people without glaucoma medication. A significant difference among treated patients depending on a preservative agent was not proved.Key words: benzalkonium chloride, glaucoma, ocular surface disease, preservatives, prostaglandin analogues.

A mouse dry eye model induced by topical administration of benzalkonium chloride.

PubMed

Lin, Zhirong; Liu, Xiaochen; Zhou, Tong; Wang, Yihui; Bai, Li; He, Hui; Liu, Zuguo

2011-01-25

To develop a dry eye model of mouse induced by topical administration of benzalkonium chloride (BAC) and investigate the possible mechanisms. BAC at concentration of 0.2% was applied to the mouse ocular surface for 7 days. Phenol red thread tear test, tear break-up time (BUT) test, corneal inflammatory index scoring, fluorescein and rose bengal test were performed to evaluate the toxic effects of BAC on the ocular surface. Global specimens were collected on day (D) 7 and labeled with a series of antibodies including cytokeratin 10 (K10) and mucin 5AC (MUC5AC). Apoptosis of ocular surface epithelium was evaluated by in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Histologic analysis and transmission electron microscopy (TEM) were performed on D7. BAC at a concentration of 0.2% successfully induced a dry eye condition with decreased tear volume and BUTs, increased corneal fluorescein and rose bengal scores. The Inflammatory index was increased in accompaniment with higher tumor necrosis factor-α (TNF-α) expression and more inflammatory infiltration in the cornea. Immunolabeling revealed positive K10 expression in BAC-treated corneal epithelium and fewer MUC5AC-positive cells in the BAC-treated conjunctival fornix. TUNEL assay showed more apoptotic cells in the corneal basal epithelium. TEM showed that the size and intervals of the microvillis were both reduced in the corneal epithelium. Topical administration of 0.2% BAC in mouse induces changes resembling that of dry eye syndrome in humans, and thus, represents a novel model of dry eye.

Catecholamine levels in the brain of rats exposed by inhalation to benzalkonium chloride.

PubMed

Swiercz, Radosław; Grzelińska, Zofia; Gralewicz, Sławomir; Wasowicz, Wojciech

2009-01-01

The aim of the study was to obtain quantitative data on the effect of inhalation exposure to benzalkonium chloride (BAC) on the concentration of catecholamines and their metabolites in selected brain structures. Additionally, concentration of corticosterone (CORT) in plasma was estimated. Wistar rats were subjected to a single (6-hour) or repeated (3 days, 6 h/day) exposure to BAC aerosol at ca. 30 mg/m3. The Waters integrated analytical system of HPLC was used to determine the plasma corticosterone. Qualitative and quantitative determinations of catecholamines and their metabolites: 3,4-dihydroxyphenylacetic (DOPAC) and homovanillic (HVA) acids were performed with the use of the Waters integrity HPLC. The determinations have shown that in the BAC-exposed rats the plasma CORT concentration was several times higher than in the control rats. A significant increase of the concentration of dopamine (DA) (striatum and diencephalon) and noradrenaline (NA) (hippocampus and cerebellum) and a significant reduction of adrenaline (A) level (cortex, hippocampus, striatum and mesencephaloon) was found to occur in the brain of rats exposed to BAC compared to control. In the animals exposed to BAC, the concentration of DOPAC, a DA metabolite, was significantly reduced, but the change occurred mainly in the striatum. This resulted in a significant decrease of the DOPAC/DA and HVA/DA metabolic ratio in this structure. It is assumed that the alterations in the concentration of catecholamines and their metabolites in the BAC-exposed rats were related to the unexpectedly strong and persistent activation of the hypothalamo-pituitary-adrenocortical (HPA) axis evidenced by the high plasma CORT concentration.

Comparative study of in vitro ocular surface cytotoxicity of a fixed combination of 0.5% timolol/1% dorzolamide eyedrop and its components with 0.005% benzalkonium chloride.

PubMed

Ayaki, Masahiko; Iwasawa, Atsuo; Niwano, Yoshimi

2012-01-01

We evaluated the cytotoxicity of antiglaucoma ophthalmic solutions preserved with the same concentration of benzalkonium chloride (BAK) in four cultured corneal and conjunctival cell lines. The viability of cell cultures was determined following the exposure of cells to timolol maleate, dorzolamide, and their fixed combination, Kosoputo(®) (MSD, a Japanese formulation of Cosopt(®) (Merck)), and two commercially available eyedrop solutions, 0.5% Timpotol(®) (containing 0.5% timolol maleate, MSD) and 1% Trusopt(®) (containing 1% dorzolamide, MSD) for varying exposure times and at various dilutions using the MTT and neutral red assays. All the three commercially available eyedrop solutions tested in this study were preserved with 0.005% BAK. The toxicity of each solution was compared using the % cell viability score (CVS) . Cell viability was also subjected to statistical analysis using ANOVA, Dunnett's multiple comparison tests and a chi-square test. %CVS50/%CVS40/80s for the tested solutions were 53/-13 for 0.5% Timoptol(®), 100/88 for preservative-free 0.5% timolol maleate, 50/ -10 for 1% Trusopt(®), 72/100 for preservative-free 1% dorzolamide, and 44/-17 for Kosoputo(®). The results of statistical analysis were consistent to them. In conclusion, Kosoputo(®) had greater cytotoxicity than each component; however, in actual use it may have the advantages of reduced toxicity (side effect) due to reduced instillation frequency, and better patient adherence to the treatment regimen as well as a comparable pressure reduction effect.

A Comparison of the Effects of Benzalkonium Chloride on Ocular Surfaces between C57BL/6 and BALB/c Mice

PubMed Central

Yang, Qian; Zhang, Yafang; Liu, Xiuping; Wang, Nan; Song, Zhenyu; Wu, Kaili

2017-01-01

Models of benzalkonium chloride (BAC)-induced ocular disruption have been created and are widely used in various animals. This study aimed to compare the effects of BAC on the ocular surfaces of C57BL/6 and BALB/c mice. C57BL/6 and BALB/c mice were treated separately with BAC eye-drops at different concentrations. Eyes were evaluated by scoring epithelial disruption, corneal opacity and neovascularization in vivo, and by histological assays with hematoxylin/eosin (H/E) and periodic acid-Schiff stainings and by determining the expression of inflammatory factors in vitro on Days 7 and 14. The in vivo corneal epithelial disruption, corneal edema/opacity and neovascularization, which were in accordance with the results of the H/E staining and peaked at Day 7, were observed in a dose-dependent manner in the BAC-treated mice, with more severe signs in the C57BL/6 mice than the BALB/c mice. The loss of conjunctival goblet cells in the conjunctivas and the increasing expression of monocyte chemoattractant protein 1 (MCP-1), growth-regulated protein alpha (GROa) and macrophage inflammatory protein-1 alpha (MIP-1a) in the corneas were found in a dose-dependent manner in both strains of mice. Topical application of BAC can dramatically disrupt the ocular surfaces of C57BL/6 and BALB/c mice, and the disruptions were much more severe in the C57BL/6 mice that received high doses of BAC. PMID:28245636

The anti-MMP activity of benzalkonium chloride

PubMed Central

Tezvergil-Mutluay, Arzu; Mutluay, M. Murat; Gu, Li-sha; Zhang, Kai; Agee, Kelli A.; Carvalho, Ricardo M.; Manso, Adriana; Carrilho, Marcela; Tay, Franklin R.; Breschi, Lorenzo; Suh, Byoung-In; Pashley, David H.

2013-01-01

SUMMARY Objective This study evaluated the ability of benzalkonium chloride (BAC) to bind to dentine and to inhibit soluble recombinant MMPs and bound dentine matrix metalloproteinases (MMPs). Methods Dentine powder was prepared from extracted human molars. Half was left mineralized; the other half was completely demineralized. The binding of BAC to dentine powder was followed by measuring changes in the supernatant concentration using UV spectrometry. The inhibitory effects of BAC on rhMMP-2, -8 and -9 were followed using a commercially available in vitro proteolytic assay. Matrix-bound endogenous MMP-activity was evaluated in completely demineralized beams. Each beam was either dipped into BAC and then dropped into 1 mL of a complete medium (CM) or they were placed in 1 mL of CM containing BAC for 30 d. After 30 d, changes in the dry mass of the beams or in the hydroxyproline (HYP) content of hydrolyzates of the media were quantitated as indirect measures of matrix collagen hydrolysis by MMPs. Results Demineralized dentine powder took up 10-times more BAC than did mineralized powder. Water rinsing removed about 50% of the bound BAC, while rinsing with 0.5 M NaCl removed more than 90% of the bound BAC. BAC concentrations 0.5 wt% produced 100% inhibition of soluble recombinant MMP-2, -8 or -9, and inhibited matrix-bound MMPs between 55-66% when measured as mass loss or 76-81% when measured as solubilization of collagen peptide fragments. Conclusions BAC is effective at inhibiting both soluble recombinant MMPs and matrix-bound dentine MMPs in the absence of resins. PMID:20951183

Coselection of Cadmium and Benzalkonium Chloride Resistance in Conjugative Transfers from Nonpathogenic Listeria spp. to Other Listeriae

PubMed Central

Katharios-Lanwermeyer, S.; Rakic-Martinez, M.; Elhanafi, D.; Ratani, S.; Tiedje, J. M.

2012-01-01

Resistance to the quaternary ammonium disinfectant benzalkonium chloride (BC) may be an important contributor to the ability of Listeria spp. to persist in the processing plant environment. Although a plasmid-borne disinfectant resistance cassette (bcrABC) has been identified in Listeria monocytogenes, horizontal transfer of these genes has not been characterized. Nonpathogenic Listeria spp. such as L. innocua and L. welshimeri are more common than L. monocytogenes in food processing environments and may contribute to the dissemination of disinfectant resistance genes in listeriae, including L. monocytogenes. In this study, we investigated conjugative transfer of resistance to BC and to cadmium from nonpathogenic Listeria spp. to other nonpathogenic listeriae, as well as to L. monocytogenes. BC-resistant L. welshimeri and L. innocua harboring bcrABC, along with the cadmium resistance determinant cadA2, were able to transfer resistance to other nonpathogenic listeriae as well as to L. monocytogenes of diverse serotypes, including strains from the 2011 cantaloupe outbreak. Transfer among nonpathogenic Listeria spp. was noticeably higher at 25°C than at 37°C, whereas acquisition of resistance by L. monocytogenes was equally efficient at 25 and 37°C. When the nonpathogenic donors were resistant to both BC and cadmium, acquisition of cadmium resistance was an effective surrogate for transfer of resistance to BC, suggesting coselection between these resistance attributes. The results suggest that nonpathogenic Listeria spp. may behave as reservoirs for disinfectant and heavy metal resistance genes for other listeriae, including the pathogenic species L. monocytogenes. PMID:22904051

A mouse dry eye model induced by topical administration of benzalkonium chloride

PubMed Central

Lin, Zhirong; Liu, Xiaochen; Zhou, Tong; Wang, Yihui; Bai, Li; He, Hui

2011-01-01

Purpose To develop a dry eye model of mouse induced by topical administration of benzalkonium chloride (BAC) and investigate the possible mechanisms. Methods BAC at concentration of 0.2% was applied to the mouse ocular surface for 7 days. Phenol red thread tear test, tear break-up time (BUT) test, corneal inflammatory index scoring, fluorescein and rose bengal test were performed to evaluate the toxic effects of BAC on the ocular surface. Global specimens were collected on day (D) 7 and labeled with a series of antibodies including cytokeratin 10 (K10) and mucin 5AC (MUC5AC). Apoptosis of ocular surface epithelium was evaluated by in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Histologic analysis and transmission electron microscopy (TEM) were performed on D7. Results BAC at a concentration of 0.2% successfully induced a dry eye condition with decreased tear volume and BUTs, increased corneal fluorescein and rose bengal scores. The Inflammatory index was increased in accompanyment with higher tumor necrosis factor-α (TNF-α) expression and more inflammatory infiltration in the cornea. Immunolabeling revealed positive K10 expression in BAC-treated corneal epithelium and fewer MUC5AC-positive cells in the BAC-treated conjunctival fornix. TUNEL assay showed more apoptotic cells in the corneal basal epithelium. TEM showed that the size and intervals of the microvillis were both reduced in the corneal epithelium. Conclusions Topical administration of 0.2% BAC in mouse induces changes resembling that of dry eye syndrome in humans, and thus, represents a novel model of dry eye. PMID:21283525

Interactions between Surfactants in Solution and Electrospun Protein Fibers: Effects on Release Behavior and Fiber Properties.

PubMed

Stephansen, Karen; García-Díaz, María; Jessen, Flemming; Chronakis, Ioannis S; Nielsen, Hanne M

2016-03-07

Intermolecular interaction phenomena occurring between endogenous compounds, such as proteins and bile salts, and electrospun compounds are so far unreported, despite the exposure of fibers to such biorelevant compounds when applied for biomedical purposes, e.g., tissue engineering, wound healing, and drug delivery. In the present study, we present a systematic investigation of how surfactants and proteins, as physiologically relevant components, interact with insulin-loaded fish sarcoplasmic protein (FSP) electrospun fibers (FSP-Ins fibers) in solution and thereby affect fiber properties such as accessible surface hydrophilicity, physical stability, and release characteristics of an encapsulated drug. Interactions between insulin-loaded protein fibers and five anionic surfactants (sodium taurocholate, sodium taurodeoxycholate, sodium glycocholate, sodium glycodeoxycholate, and sodium dodecyl sulfate), a cationic surfactant (benzalkonium chloride), and a neutral surfactant (Triton X-100) were studied. The anionic surfactants increased the insulin release in a concentration-dependent manner, whereas the neutral surfactant had no significant effect on the release. Interestingly, only minute amounts of insulin were released from the fibers when benzalkonium chloride was present. The FSP-Ins fibers appeared dense after incubation with this cationic surfactant, whereas high fiber porosity was observed after incubation with anionic or neutral surfactants. Contact angle measurements and staining with the hydrophobic dye 8-anilino-1-naphthalenesulfonic acid indicated that the FSP-Ins fibers were hydrophobic, and showed that the fiber surface properties were affected differently by the surfactants. Bovine serum albumin also affected insulin release in vitro, indicating that also proteins may affect the fiber performance in an in vivo setting.

Antiseptic mouth rinses: an update on comparative effectiveness, risks and recommendations.

PubMed

Osso, Diane; Kanani, Nehal

2013-02-01

Antiseptic mouth rinses are widely recommended and marketed to improve oral health. This article summarizes current studies on the comparative effectiveness of selected antiseptic mouth rinses in controlling plaque and gingivitis, as well as risks associated with daily exposure, including salivary flow rate, oral cancer and wear of composite restorations. Electronic database searches were conducted using Google Scholar and PubMed to identify articles comparing the effectiveness of 4 commercially marketed antiseptic mouth rinses differing in active ingredients (0.12% chlorhexidine gluconate, essential oils (menthol, thymol and eucalyptol) and methyl salicylate, 0.7% cetylpyridinium chloride and 20% aloe vera gel) for controlling plaque and gingivitis. Criteria for inclusion included controlled clinical trials and systematic reviews appearing in English language publications evaluating the comparative effectiveness of the mouth rinses in controlling plaque and gingivitis, as well as risks associated with daily usage. The majority of studies have shown mouth rinses containing chlorhexidine gluconate or essential oils and methyl salicylate provide clinically significant anti-gingivitis and anti-plaque benefits. Cetylpyridinium chloride has been found to provide only limited clinical benefits compared to inactive control mouth rinse. Inadequate evidence is available to evaluate the clinical effectiveness of aloe vera gel. Chlorhexidine, essential oils and cetylpyridinium have been found to be safe. However, limited data are available on the effects of the mouth rinse on wear patterns of dental restorations. Studies reviewed reported no significant difference in salivary flow rate related to alcohol based mouth rinse. Research supports the effectiveness of antiseptic mouth rinses in reducing plaque and gingivitis as an adjunct to home care. Insufficient evidence is available to support the claim that oral antiseptics can reduce the risk of developing periodontitis or the rate of progression of periodontitis.

Polymorphic Variation in Susceptibility and Metabolism of Triclosan-Resistant Mutants of Escherichia coli and Klebsiella pneumoniae Clinical Strains Obtained after Exposure to Biocides and Antibiotics

PubMed Central

Curiao, Tânia; Marchi, Emmanuela; Viti, Carlo; Oggioni, Marco R.; Baquero, Fernando; Martinez, José Luis

2015-01-01

Exposure to biocides may result in cross-resistance to other antimicrobials. Changes in biocide and antibiotic susceptibilities, metabolism, and fitness costs were studied here in biocide-selected Escherichia coli and Klebsiella pneumoniae mutants. E. coli and K. pneumoniae mutants with various degrees of triclosan susceptibility were obtained after exposure to triclosan (TRI), benzalkonium chloride (BKC), chlorhexidine (CHX) or sodium hypochlorite (SHC), and ampicillin or ciprofloxacin. Alterations in antimicrobial susceptibility and metabolism in mutants were tested using Phenotype MicroArrays. The expression of AcrAB pump and global regulators (SoxR, MarA, and RamA) was measured by quantitative reverse transcription-PCR (qRT-PCR), and the central part of the fabI gene was sequenced. The fitness costs of resistance were assessed by a comparison of relative growth rates. Triclosan-resistant (TRIr) and triclosan-hypersusceptible (TRIhs) mutants of E. coli and K. pneumoniae were obtained after selection with biocides and/or antibiotics. E. coli TRIr mutants, including those with mutations in the fabI gene or in the expression of acrB, acrF, and marA, exhibited changes in susceptibility to TRI, CHX, and antibiotics. TRIr mutants for which the TRI MIC was high presented improved metabolism of carboxylic acids, amino acids, and carbohydrates. In TRIr mutants, resistance to one antimicrobial provoked hypersusceptibility to another one(s). TRIr mutants had fitness costs, particularly marA-overexpressing (E. coli) or ramA-overexpressing (K. pneumoniae) mutants. TRI, BKC, and CIP exposure frequently yielded TRIr mutants exhibiting alterations in AraC-like global regulators (MarA, SoxR, and RamA), AcrAB-TolC, and/or FabI, and influencing antimicrobial susceptibility, fitness, and metabolism. These various phenotypes suggest a trade-off of different selective processes shaping the evolution toward antibiotic/biocide resistance and influencing other adaptive traits. PMID:25824225

Polymorphic variation in susceptibility and metabolism of triclosan-resistant mutants of Escherichia coli and Klebsiella pneumoniae clinical strains obtained after exposure to biocides and antibiotics.

PubMed

Curiao, Tânia; Marchi, Emmanuela; Viti, Carlo; Oggioni, Marco R; Baquero, Fernando; Martinez, José Luis; Coque, Teresa M

2015-01-01

Exposure to biocides may result in cross-resistance to other antimicrobials. Changes in biocide and antibiotic susceptibilities, metabolism, and fitness costs were studied here in biocide-selected Escherichia coli and Klebsiella pneumoniae mutants. E. coli and K. pneumoniae mutants with various degrees of triclosan susceptibility were obtained after exposure to triclosan (TRI), benzalkonium chloride (BKC), chlorhexidine (CHX) or sodium hypochlorite (SHC), and ampicillin or ciprofloxacin. Alterations in antimicrobial susceptibility and metabolism in mutants were tested using Phenotype MicroArrays. The expression of AcrAB pump and global regulators (SoxR, MarA, and RamA) was measured by quantitative reverse transcription-PCR (qRT-PCR), and the central part of the fabI gene was sequenced. The fitness costs of resistance were assessed by a comparison of relative growth rates. Triclosan-resistant (TRI(r)) and triclosan-hypersusceptible (TRI(hs)) mutants of E. coli and K. pneumoniae were obtained after selection with biocides and/or antibiotics. E. coli TRI(r) mutants, including those with mutations in the fabI gene or in the expression of acrB, acrF, and marA, exhibited changes in susceptibility to TRI, CHX, and antibiotics. TRI(r) mutants for which the TRI MIC was high presented improved metabolism of carboxylic acids, amino acids, and carbohydrates. In TRI(r) mutants, resistance to one antimicrobial provoked hypersusceptibility to another one(s). TRI(r) mutants had fitness costs, particularly marA-overexpressing (E. coli) or ramA-overexpressing (K. pneumoniae) mutants. TRI, BKC, and CIP exposure frequently yielded TRI(r) mutants exhibiting alterations in AraC-like global regulators (MarA, SoxR, and RamA), AcrAB-TolC, and/or FabI, and influencing antimicrobial susceptibility, fitness, and metabolism. These various phenotypes suggest a trade-off of different selective processes shaping the evolution toward antibiotic/biocide resistance and influencing other adaptive traits. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Analysis of residual products in triethylbenzylammonium chloride by HPLC. Study of the retention mechanism.

PubMed

Prieto-Blanco, M C; López-Mahía, P; Prada-Rodríguez, D

2006-04-01

The control of industrial products for minimization of their impact on the environment and human health requires the development of specific analysis methods. Information provided by these methods about toxic components, by-products, and other derivatives may also be useful to reduce the possible impact of industrial products. The studied compound in this paper, triethylbenzylammonium chloride (TEBA), is mainly used in industrial synthesis. This quaternary compound and its residual products coming from quaternization reaction (benzyl chloride, benzaldehyde, and benzyl alcohol) are analyzed by HPLC. The separation is based on control of the silanophilic contribution to TEBA retention because of the quaternary nature of this compound. The effect of the three buffers (sodium acetate, ammonium acetate, and sodium formate) and their concentrations in the chromatographic behavior of the quaternary compound is examined. The buffer cation and anion regulate TEBA retention. Also, the concentration of the quaternary compound is another parameter that had influence in some aspects of its chromatographic behavior (e.g., retention and symmetry). The proposed method is applied to TEBA synthesis along, with the formation and removal of impurities with the results compared with those obtained for the quaternary compound benzalkonium chloride.

A comparison between DACC with chlorhexidine acetate-soaked paraffin gauze and foam dressing for skin graft donor sites.

PubMed

Lee, Jun Won; Park, Seong Hoon; Suh, In Suck; Jeong, Hii Sun

2018-01-02

Retrograde infections often occur with excessive or incomplete drainage of exudate, or as a result of adherence of dressings to wounds. Dialkylcarbamoyl chloride (DACC) irreversibly binds to bacterial surfaces and physically removes bacteria when dressings are changed. Chlorhexidine acetate-soaked paraffin gauze provides a moist wound-healing environment. We hypothesise that when DACC is combined with chlorhexidine acetate-soaked paraffin gauze, wound healing times decrease. From January 2013 to June 2015, medical records were retrospectively evaluated in 60 patients who underwent split-thickness skin grafts (STSG). Patients were divided into two groups: a 'thick skin group' and a 'thin skin group'. These two groups were further subdivided into a control group, where conventional foam dressings were applied to wounds, and an experimental group, where chlorhexidine acetate-soaked paraffin gauze with DACC was applied (DACC group). We compared the wound healing time between these subgroups. Differences in infected wound healing times were also compared. The Mann-Whitney test was applied to compare wound healing times between groups. Epithelialisation duration was significantly shorter in the DACC group. The control group had longer wound healing times, regardless of wound size. In the thick skin group, the median healing duration was 12 days in the control subgroup, compared with 9.5 days in the DACC subgroup (p=0.049). In the thin skin subgroup, the median healing duration in the control group was 18 days, compared with 10 days in the DACC subgroup (p=0.013). Application of DACC and chlorhexidine acetate-soaked paraffin gauze to skin graft donor sites can shorten healing times and is effective in treating infected wounds.

Intrinsic Resistance of Burkholderia cepacia Complex to Benzalkonium Chloride

PubMed Central

Ahn, Youngbeom; Kim, Jeong Myeong; Kweon, Ohgew; Kim, Seong-Jae; Jones, Richard C.; Woodling, Kellie; Gamboa da Costa, Gonçalo; LiPuma, John J.; Hussong, David; Marasa, Bernard S.

2016-01-01

ABSTRACT Pharmaceutical products that are contaminated with Burkholderia cepacia complex (BCC) bacteria may pose serious consequences to vulnerable patients. Benzyldimethylalkylammonium chloride (BZK) cationic surfactants are extensively used in medical applications and have been implicated in the coselection of antimicrobial resistance. The ability of BCC to degrade BZK, tetradecyldimethylbenzylammonium chloride (C14BDMA-Cl), dodecyldimethylbenzylammonium chloride (C12BDMA-Cl), decyldimethylbenzylammonium chloride (C10BDMA-Cl), hexyldimethylbenzylammonium chloride, and benzyltrimethylammonium chloride was determined by incubation in 1/10-diluted tryptic soy broth (TSB) to determine if BCC bacteria have the ability to survive and inactivate these disinfectants. With BZK, C14BDMA-Cl, and C12BDMA-Cl, inhibition of the growth of 20 BCC strains was observed in disinfectant solutions that ranged from 64 to 256 µg/ml. The efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone increased the sensitivity of bacteria to 64 µg/ml BZK. The 20 BCC strains grew well in 1/10-diluted TSB medium with BZK, C12BDMA-Cl, and C10BDMA-Cl; they absorbed and degraded the compounds in 7 days. Formation of benzyldimethylamine and benzylmethylamine as the initial metabolites suggested that the cleavage of the C alkyl-N bond occurred as the first step of BZK degradation by BCC bacteria. Proteomic data confirmed the observed efflux activity and metabolic inactivation via biodegradation in terms of BZK resistance of BCC bacteria, which suggests that the two main resistance mechanisms are intrinsic and widespread. PMID:27879334

Efficiency of inhibitor for biocorrosion influenced by consortium sulfate reducing bacteria on carbon steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahat, Nur Akma; Othman, Norinsan Kamil; Sahrani, Fathul Karim

2015-09-25

The inhibition efficiency of benzalkonium chloride (BKC) in controlling biocorrosion on the carbon steel surfaces has been investigated. The carbon steel coupons were incubated in the presence of consortium SRB (C-SRB) with and without BKC for the difference medium concentration. The corrosion rate and inhibition efficiency have been evaluated by a weight loss method. The morphology of biofilm C-SRB on the steel surfaces were characterized with variable pressure scanning electron microscopy (VPSEM). The results revealed that BKC exhibits a low corrosion rate, minimizing the cell growth and biofilm development on the carbon steel surfaces.

Fundamental Studies on High Temperature Deformation Recrystallization, and Grain Growth of Two-Phase Materials.

DTIC Science & Technology

1988-01-01

gm (17 ml) Benzalkonium . Chloride (50%) 35 ml Ethanol The Ti-V alloys were etched with the following etchant for 6 to 10 seconds. 4 mlHN03 conc. 2 ml...60 % reduction in area was given for all the alloys. This work was found to be sufficient to recrystallize all of the alloys within 6 hours at 9730 K...condition of net reduction in surfaces 17 °.4- *. *¢ ’ N N-, . ’ . . ’,, . , . . .,...’,’." ,,_...,. ,...’.’.’, ...-.......-.. : ’If LS becomes b2 .(db]/d1

Efficiency of inhibitor for biocorrosion influenced by consortium sulfate reducing bacteria on carbon steel

NASA Astrophysics Data System (ADS)

Mahat, Nur Akma; Othman, Norinsan Kamil; Sahrani, Fathul Karim

2015-09-01

The inhibition efficiency of benzalkonium chloride (BKC) in controlling biocorrosion on the carbon steel surfaces has been investigated. The carbon steel coupons were incubated in the presence of consortium SRB (C-SRB) with and without BKC for the difference medium concentration. The corrosion rate and inhibition efficiency have been evaluated by a weight loss method. The morphology of biofilm C-SRB on the steel surfaces were characterized with variable pressure scanning electron microscopy (VPSEM). The results revealed that BKC exhibits a low corrosion rate, minimizing the cell growth and biofilm development on the carbon steel surfaces.

Fundamental Studies on High Temperature Deformation, Recrystallization, and Grain Growth of Two-Phase Materials.

DTIC Science & Technology

1987-02-18

17 ml) Benzalkonium Chloride (50%) 4 35 ml Ethanol The Ti-V alloys were etched with the following ethant for about 10 sec. 4% HNO 3 2% HF Bal. H 0 2...that in the last *step all the alloys were processed in the ax+ 6 field from 973 0K L 0 (700 C). The amount of work given in this step (60% reduction in...interfaces (29). The interfaces move by random jumping of atoms from grain to grain, the driving force for the process being the reduction of free

The Use of Chlorhexidine/n-Propyl Gallate (CPG) as an Ambient-Temperature Urine Preservative

NASA Technical Reports Server (NTRS)

Nillen, Jeannie L.; Smith, Scott M.

2003-01-01

A safe, effective ambient temperature urine preservative, chlorhexidine/n-propyl gallate (CPG), has been formulated for use during spacefli ght that reduces the effects of oxidation and bacterial contamination on sample integrity while maintaining urine pH. The ability of this preservative to maintain stability of nine key analytes was evaluated for a period of one year. CPG effectively maintained stability of a mmonia, total nitrogen, 3-methylhistidine, chloride, sodium, potassiu m, and urea; however, creatinine and osmolality were not preserved by CPG. These data indicate that CPG offers prolonged room-temperature storage for multiple urine analytes, reducing the requirements for f rozen urine storage on future spaceflights. Iii medical applications on Earth, this technology can allow urine samples to be collected in remote settings and eliminate the need to ship frozen samples.

Antimicrobial activity of topically-applied soyaethyl morpholinium ethosulfate micelles against Staphylococcus species.

PubMed

Yang, Shih-Chun; Aljuffali, Ibrahim A; Sung, Calvin T; Lin, Chwan-Fwu; Fang, Jia-You

2016-03-01

Here we evaluated the antibacterial efficacy of soyaethyl morpholinium ethosulfate (SME) micelles as an inherent bactericide against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA). The antimicrobial activity was examined by in vitro culture model and murine model of skin infection. Cationic micelles formed by benzalkonium chloride or cetylpyridinium chloride were used for comparison. The minimum inhibitory concentration and minimum bactericidal concentration against S. aureus and MRSA were 1.71-3.42 and 1.71-6.84 μg/ml, respectively. Topical administration of SME micelles significantly decreased the cutaneous infection and MRSA load in mice. The killing of bacteria was caused by direct cell wall/membrane rupture. SME micelles also penetrated into the bacteria to elicit a Fenton reaction and oxidative stress. SME micelles have potential as antimicrobial agents due to their lethal effect against S. aureus and MRSA with a low toxicity to mammalian cells.

Poly(vinyl chloride) catheters modified with pH-responsive poly(methacrylic acid) with affinity for antimicrobial agents

NASA Astrophysics Data System (ADS)

Zuñiga-Zamorano, Ivette; Meléndez-Ortiz, H. Iván; Costoya, Alejandro; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Bucio, Emilio

2018-01-01

Radiation-grafting of pH-responsive methacrylic acid (MAA) onto poly(vinyl chloride) (PVC) was carried out by the pre-irradiation method using gamma rays, which demonstrated to be an efficient and fast procedure for obtaining PVC-g-MAA copolymers. The influence of preparation conditions, such as absorbed dose, monomer concentration, reaction time, and reaction temperature on the grafting yield was studied. The grafting of MAA onto PVC catheters was confirmed by means of Fourier transform infrared spectroscopy (FT-IR), thermogravimetry analysis (TGA), and differential scanning calorimetry (DSC). The pH-responsiveness of the grafted copolymers (critical point 8.5) was measured by swelling under cyclic changes in the pH of the medium. Interestingly, PVC-g-MAA showed enhanced capability to immobilize benzalkonium chloride and, particularly, ciprofloxacin and to sustain the release this antimicrobial agent at both acid and alkaline pH. Tests carried out with Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus point out that the developed functionalized catheters may play a role in the prevention/management of urinary tract infections.

Effectiveness of disinfectants used in cooling towers against Legionella pneumophila.

PubMed

García, M T; Pelaz, C

2008-01-01

Legionella persists in man-made aquatic installations despite preventive treatments. More information about disinfectants could improve the effectiveness of treatments. This study tests the susceptibility of Legionella pneumophila serogroup (sg) 1 against 8 disinfectants used in cooling tower treatments. We determined the minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and bactericidal effect of sodium hypochlorite (A), hydrogen peroxide with silver nitrate (B), didecyldimethylammonium chloride (C), benzalkonium chloride (D), tributyltetradecylphosphonium chloride (E), tetrahydroxymethylphosphonium sulfide (F), 2,2-dibromonitropropionamide (G) and chloromethylisothiazolone (H) against 28 L. pneumophila sg 1 isolates. MIC and MBC values were equivalent. Bacteria are less susceptible to disinfectants F, B, D and A than to H, E, C and G. All disinfectants induced a bactericidal effect. The effect rate is dose dependent for G, H, F and B; the effect is fast for the rest of disinfectants at any concentration. The bactericidal activity of disinfectants A, G and F depends on the susceptibility test used. All disinfectants have bactericidal activity against L. pneumophila sg 1 at concentrations used in cooling tower treatments. Results depend on the assay for some products.

Evaluation of 5 cleaning and disinfection methods for nets used to collect zebrafish (Danio rerio).

PubMed

Collymore, Chereen; Porelli, Gina; Lieggi, Christine; Lipman, Neil S

2014-11-01

Few standardized methods of cleaning and disinfecting equipment in zebrafish facilities have been published, even though the effectiveness of these procedures is vital to preventing the transmission of pathogenic organisms. Four chemical disinfectants and rinsing with municipal tap water were evaluated for their ability to disinfect nets used to capture zebrafish. The disinfectants included benzalkonium chloride+methylene blue, sodium hypochlorite, chlorine dioxide, and potassium peroxymonosulfate+sodium chloride for a soak time of 5 or 30 min. Disinfection effectiveness was evaluated by using an ATP-based system that measured the reduction in absolute number and percentage of relative light units. In addition, nets were cultured aerobically on blood and MacConkey agar plates to determine the number of bacteria remaining after disinfection procedures. Soaking nets in sodium hypochlorite for 30 min and in potassium peroxymonosulfate+sodium chloride for 5 or 30 min were effective means of disinfection, according to at least 90% reduction in the number of relative light units and no bacterial growth after cleaning. These results will aid facility managers, veterinarians and investigators in selecting net cleaning and disinfection protocols.

Evaluation of 5 Cleaning and Disinfection Methods for Nets Used to Collect Zebrafish (Danio rerio)

PubMed Central

Collymore, Chereen; Porelli, Gina; Lieggi, Christine; Lipman, Neil S

2014-01-01

Few standardized methods of cleaning and disinfecting equipment in zebrafish facilities have been published, even though the effectiveness of these procedures is vital to preventing the transmission of pathogenic organisms. Four chemical disinfectants and rinsing with municipal tap water were evaluated for their ability to disinfect nets used to capture zebrafish. The disinfectants included benzalkonium chloride+methylene blue, sodium hypochlorite, chlorine dioxide, and potassium peroxymonosulfate+sodium chloride for a soak time of 5 or 30 min. Disinfection effectiveness was evaluated by using an ATP-based system that measured the reduction in absolute number and percentage of relative light units. In addition, nets were cultured aerobically on blood and MacConkey agar plates to determine the number of bacteria remaining after disinfection procedures. Soaking nets in sodium hypochlorite for 30 min and in potassium peroxymonosulfate+sodium chloride for 5 or 30 min were effective means of disinfection, according to at least 90% reduction in the number of relative light units and no bacterial growth after cleaning. These results will aid facility managers, veterinarians and investigators in selecting net cleaning and disinfection protocols. PMID:25650972

The antifungal properties of chlorhexidine digluconate and cetylpyrinidinium chloride on oral Candida.

PubMed

Fathilah, A R; Himratul-Aznita, W H; Fatheen, A R N; Suriani, K R

2012-07-01

C. tropicalis and C. krusei have emerged as virulent species causing oral infections. Both have developed resistance to commonly prescribed azole antifungal agents. The study aimed to determine the effect of mouth rinses containing chlorhexidine digluconate (CHX), cetylpyridinium chloride (CPC) and their combination (CHX-CPC) on the growth of these strains. The minimal inhibition concentrations (MIC) of the mouth rinses were determined. The growth curves of the strains produced under the mouth rinse-treated and untreated conditions, as well as alterations to the morphology of the growth colonies and cells following the treatments were compared and analysed. The MICs of CPC compared to CHX mouth rinses were found to be lower for both Candida sp. In the mixed formulation, CPC doubled the inhibitory effect of CHX towards both Candida sp., while CHX quadrupled the activity of CPC towards C. tropicalis. The growth colonies also appeared coarse, wrinkled and dried. The profound effects shown may suggest the fungicidal activities of the mouth rinses incorporated with CHX, CPC or their combination on both C. tropicalis and C. krusei. Gargling using mouth rinses with such fungicidal activity would enhance a rapid reduction in the candidal population of patients with fungal infection. Copyright © 2012 Elsevier Ltd. All rights reserved.

Anti-inflammatory effects of nitric oxide-releasing hydrocortisone NCX 1022, in a murine model of contact dermatitis

PubMed Central

Hyun, Eric; Bolla, Manlio; Steinhoff, Martin; Wallace, John L; Soldato, Piero del; Vergnolle, Nathalie

2004-01-01

The concept that nitric oxide (NO) release can be beneficial in inflammatory conditions has raised more attention in the recent years, particularly with the development of nitric oxide-releasing anti-inflammatory drugs. There is considerable evidence that NO is capable of enhancing the anti-inflammatory benefits of conventional anti-inflammatory drugs. Since hydrocortisone is the most widely used anti-inflammatory drug for the treatment of skin inflammation, we compared the anti-inflammatory effects of hydrocortisone to an NO-releasing derivative of hydrocortisone, NCX 1022, in a murine model of irritant contact dermatitis, induced by epidermal application of benzalkonium chloride. Topical pre- and post-treatment with NCX 1022 (3 nmol) in C57BL6 mice not only reduced ear oedema formation in a dose-dependent manner, but also was significantly more effective than the parent compound during the initial stages of inflammation (from 1 to 5 h). NCX 1022, but not hydrocortisone, significantly inhibited granulocyte recruitment (tissue myeloperoxidase activity). Histological samples of mouse ears treated with NCX 1022 showed significant reduction in both the number of infiltrated cells and disruption of the tissue architecture compared to hydrocortisone-treated tissues. With intravital microscopy, we observed that both pre- and post-treatments with NCX 1022 were more effective than hydrocortisone in terms of inhibiting benzalkonium chloride-induced leukocyte adhesion to the endothelium, without affecting the flux of rolling leukocytes or venule diameter. These results suggest that by releasing NO, NCX 1022 modulates one of the early events of skin inflammation: the recruitment of leukocytes to the site of inflammation. Overall, we have shown that NO-hydrocortisone provided faster and greater protective effects, reducing major inflammatory parameters (leukocyte adhesion and recruitment, oedema formation, tissue disruption) compared to its parental compound. PMID:15313880

The effect of resveratrol on protecting corneal epithelial cells from cytotoxicity caused by moxifloxacin and benzalkonium chloride.

PubMed

Tsai, Tzu-Yun; Chen, Ta-Ching; Wang, I-Jong; Yeh, Chao-Yuan; Su, Ming-Jai; Chen, Ruey-Hua; Tsai, Tzu-Hsun; Hu, Fung-Rong

2015-02-10

Moxifloxacin (MOX), a fourth generation fluoroquinolone (FQ), has a wide antibacterial spectrum, but may show cytotoxicity characterized by high productions of reactive oxygen species (ROS). This study investigated the protective role of a common antioxidant agent, resveratrol (trans-3,5,4'-trihydroxystilbene), against the cytotoxicity caused by MOX. Experiments were performed with a human corneal epithelial cell line (HCECs; ATCC-CRL-11515). Another commonly used FQ, levofloxacin (LEV), and the most commonly used preservatives, benzalkonium chloride (BAC), were also used for comparison with MOX. Cell viability and morphologic changes after treatment were evaluated with trypan blue exclusion assay, propidium iodine/annexin V-FITC staining, and flow cytometry. Chemiluminescence immunoassay was used for ROS quantification. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, wound healing assay, and intracellular detections of oxidative stress were performed to evaluate the effects of resveratrol. The MOX group, similar to the BAC group, showed significant cell shrinkage and death compared with the LEV group. High ROS production in HCECs of MOX group was observed both by chemiluminescence immunoassay and intracellular images. Within the observations of MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay, live cell images, and wound healing process in vitro, the cytotoxic effects of the MOX and BAC groups were opposed by resveratrol. Human corneal epithelial cells pretreated with resveratrol demonstrated better cell viability and healing rate in the early stage. The protective effects of antioxidant agents indicate that MOX, similar to BAC, causes oxidative stress-related cell damage. The results also inspired us to think about a "supplementary regimen" to increase safety and decrease the adverse effect in the treatment of corneal infections. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

Effect of a Benzalkonium Chloride Surfactant-Sodium Hypochlorite Combination on Elimination of Enterococcus faecalis.

PubMed

Baron, Aleksandr; Lindsey, Kimberly; Sidow, Stephanie J; Dickinson, Douglas; Chuang, Augustine; McPherson, James C

2016-01-01

The purpose of this investigation was to determine the effect of a sodium hypochlorite-surfactant combination on the removal of Enterococcus faecalis from infected teeth. Sixty-four extracted human single canal anterior teeth were prepared with rotary instrumentation and sterilized. Teeth were divided into 4 groups, N = 16. Three experimental groups were inoculated with E. faecalis and cultured for 21 days before use: positive control group, no irrigation; NaOCl group, irrigated with 5 mL 6% NaOCl; and NaOCl/BAK group, irrigated with 5 mL 6% NaOCl/0.008% benzalkonium chloride (BAK). The negative control group received medium only and no inoculate. Paper point sampling of the canals was obtained before irrigation (S1) for all 4 groups and for 2 groups after irrigation (S2) to determine remaining colony-forming units. After sampling, all teeth were split in half and evaluated for bacterial viability colony-forming units and penetration of dentinal tubules by using fluorescent vital dye staining and confocal laser scanning microscopy. Comparison of pre-irrigation and post-irrigation paper point samples from the 2 irrigated groups showed a significant reduction in bacterial canal load (P < .001, Kruskal-Wallis), with a significantly lower load in the NaOCl/BAK group than in the NaOCl group (P = .001, Mann-Whitney U test); 68.8% of the NaOCl/BAK samples gave no recoverable counts. In contrast, no significant difference between these groups was found for counts recovered from dentin. Confocal laser scanning microscopy showed no differences in tubule penetration. The addition of BAK to NaOCl significantly reduced the number of remaining bacteria within the canal after irrigation compared with NaOCl alone. Published by Elsevier Inc.

Benzalkonium Chloride Provides Remarkable Stability to Liquid Protein Lures for Trapping Anastrepha obliqua (Diptera: Tephritidae).

PubMed

Lasa, R; Williams, T

2017-12-05

Hydrolyzed protein lures are widely used to monitor fruit fly pests but are rapidly degraded by microbial activity and must be replaced frequently. To improve the stability of lures, the quaternary ammonium biocide, benzalkonium chloride (BC), was evaluated in mixtures with two hydrolyzed proteins commonly used to monitor Anastrepha spp. The mean number of Anastrepha obliqua adults captured during six consecutive weeks using Captor + borax with the addition of 240 mg BC/liter, not renewed during the test, was similar to Captor + borax that was replaced at weekly intervals and was more effective than Captor + borax without BC. Numbers of A. obliqua flies captured in 30% CeraTrap diluted in water containing 240 mg BC/liter were similar to those caught in traps baited with Captor + borax or 30% CeraTrap without BC in the first 9 d of evaluation but was significantly more effective than both lures after 56 d. After >2 mo of use, 30% CeraTrap containing 240 mg BC/liter remained as effective as newly prepared 30% CeraTrap. The addition of BC to lures reduced surface tension of liquid lures by ~40-50%. However, when BC was increased to 720 mg BC/liter, only a small additional reduction in surface tension was observed and higher concentrations of BC did not increase capture rates. These findings could contribute to reduced costs for trapping networks and the development of long-lasting formulations of liquid protein lures for bait stations and mass-trapping targeted at major tephritid pests. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Co-Culture with Listeria monocytogenes within a Dual-Species Biofilm Community Strongly Increases Resistance of Pseudomonas putida to Benzalkonium Chloride

PubMed Central

Giaouris, Efstathios; Chorianopoulos, Nikos; Doulgeraki, Agapi; Nychas, George-John

2013-01-01

Biofilm formation is a phenomenon occurring almost wherever microorganisms and surfaces exist in close proximity. This study aimed to evaluate the possible influence of bacterial interactions on the ability of Listeria monocytogenes and Pseudomonas putida to develop a dual-species biofilm community on stainless steel (SS), as well as on the subsequent resistance of their sessile cells to benzalkonium chloride (BC) used in inadequate (sub-lethal) concentration (50 ppm). The possible progressive adaptability of mixed-culture biofilms to BC was also investigated. To accomplish these, 3 strains per species were left to develop mixed-culture biofilms on SS coupons, incubated in daily renewable growth medium for a total period of 10 days, under either mono- or dual-species conditions. Each day, biofilm cells were exposed to disinfection treatment. Results revealed that the simultaneous presence of L. monocytogenes strongly increased the resistance of P. putida biofilm cells to BC, while culture conditions (mono-/dual-species) did not seem to significantly influence the resistance of L. monocytogenes biofilm cells. BC mainly killed L. monocytogenes cells when this was applied against the dual-species sessile community during the whole incubation period, despite the fact that from the 2nd day this community was mainly composed (>90%) of P. putida cells. No obvious adaptation to BC was observed in either L. monocytogenes or P. putida biofilm cells. Pulsed field gel electrophoresis (PFGE) analysis showed that the different strains behaved differently with regard to biofilm formation and antimicrobial resistance. Such knowledge on the physiological behavior of mixed-culture biofilms could provide the information necessary to control their formation. PMID:24130873

The leaves of Diospyros kaki exert beneficial effects on a benzalkonium chloride-induced murine dry eye model.

PubMed

Kim, Kyung-A; Hyun, Lee Chung; Jung, Sang Hoon; Yang, Sung Jae

2016-01-01

In this study, the beneficial effects of the oral administration of ethanol extract of Diospyros kaki (EEDK) were tested on a mouse dry eye model induced by benzalkonium chloride (BAC). A solution of 0.2% BAC was administered topically to mouse eyes for 14 days, twice daily, to induce dry eye. Various concentrations of EEDK were administrated daily by oral gavage for 14 days after BAC treatment. Preservative-free eye drops were instilled in the positive-control group. The tear secretion volume (Schirmer's test), tear break-up time (BUT), and fluorescein score were measured on the ocular surface. BAC-induced corneal damage was tested with hematoxylin-eosin staining. Moreover, apoptotic cell death in the corneal epithelial layer was investigated with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. The protein expression level of interleukin-1alpha (IL-1α), IL-1β, IL-6, tumor necrosis factor- alpha (TNF-α), and monocyte chemotactic protein-1 (MCP-1) was determined with western blot analysis. Furthermore, squamous metaplasia in the corneal epithelial layer was detected with immunofluorescent staining for cytokeratine-10. The cellular proliferation in the cornea was examined with immunohistochemical staining for Ki-67. EEDK treatment resulted in prolonged BUT, decreased fluorescein score, increased tear volume, and smoother epithelial cells compared with BAC treatment alone in the cornea. Moreover, EEDK treatment inhibited the inflammatory response and corneal epithelial cell death in a BAC-induced murine dry eye model, and changes in squamous cells were inhibited. Proliferative activity in the corneal epithelium cells was improved with EEDK. EEDK could be a potential therapeutic agent in the clinical treatment of dry eye.

Use of porcine vaginal tissue ex-vivo to model environmental effects on vaginal mucosa to toxic shock syndrome toxin-1.

PubMed

Davis, Catherine C; Baccam, Mekhine; Mantz, Mary J; Osborn, Thomas W; Hill, Donna R; Squier, Christopher A

2014-01-15

Menstrual toxic shock syndrome (mTSS) is a rare, recognizable, and treatable disease that has been associated with tampon use epidemiologically. It involves a confluence of microbial risk factors (Staphylococcus aureus strains that produce the superantigen-TSST-1), as well as environmental characteristics of the vaginal ecosystem during menstruation and host susceptibility factors. This paper describes a series of experiments using the well-characterized model of porcine vaginal mucosa ex-vivo to assess the effect of these factors associated with tampon use on the permeability of the mucosa. The flux of radiolabeled TSST-1 and tritiated water ((3)H2O) through porcine vaginal mucosa was determined at various temperatures, after mechanical disruption of the epithelial surface by tape stripping, after treatment with surfactants or other compounds, and in the presence of microbial virulence factors. Elevated temperatures (42, 47 and 52°C) did not significantly increase flux of (3)H2O. Stripping of the epithelial layers significantly increased the flux of labeled toxin in a dose-dependent manner. Addition of benzalkonium chloride (0.1 and 0.5%) and glycerol (4%) significantly increased the flux of (3)H2O but sodium lauryl sulfate at any concentration tested did not. The flux of the labeled toxin was significantly increased in the presence of benzalkonium chloride but not Pluronic® L92 and Tween 20 and significantly increased with addition of α-hemolysin but not endotoxin. These results show that the permeability of porcine vagina ex-vivo to labeled toxin or water can be used to evaluate changes to the vaginal environment and modifications in tampon materials, and thus aid in risk assessment. Copyright © 2013 Elsevier Inc. All rights reserved.

Cytoprotective effect of lacritin on human corneal epithelial cells exposed to benzalkonium chloride in vitro

PubMed Central

Feng, Mary M.; Baryla, Julia; Liu, Hong; Laurie, Gordon W.; McKown, Robert L.; Ashki, Negin; Bhayana, Dinesh

2015-01-01

Purpose Benzalkonium chloride (BAK) is the most commonly found preservative in eye drops, and has been shown to cause ocular surface inflammation and toxicity. Lacritin is a human tear glycoprotein secreted from the lacrimal glands that has been found to be cytoprotective. This study was designed to determine if the presence of lacritin confers protection to a cultured human corneal epithelial (HCE) cell line, CRL-11515, and primary HCE cells after exposure to the ocular preservative agent BAK. Materials and Methods Recombinant human lacritin was cloned into intein fusion vectors, expressed in E. coli, and purified on chitin beads and DEAE Sepharose. Metabolic curves were established using the MTT assay after exposure of subconfluent CRL-11515 cells to BAK or lacritin. Western blot analysis of lipidated LC3 (LC3-II) provided a measure of autophagy in CRL-11515 cells exposed to lacritin and/or BAK. Results BAK reduced CRL-11515 cellular metabolic activity in a time and dose dependent manner. BAK-induced cellular stress was evident by elevated autophagy that increased with rising concentrations of BAK compared to control (P < 0.05). Lacritin increased HCE cell proliferation at an optimal dose of 1 nM. Preconditioning HCE cells with 1 nM lacritin for 24 hours prior to BAK exposure significantly dampened levels of LC3-II (P < 0.05) and promoted a significant increase in cellular metabolic activity (P < 0.01) compared to BAK alone. Conclusions These results suggest lacritin protects cultured HCE cells stressed with BAK. Lacritin may have the potential to be used as a topical adjunctive therapy in eyes chronically exposed to BAK. PMID:24401093

Cytoprotective effect of lacritin on human corneal epithelial cells exposed to benzalkonium chloride in vitro.

PubMed

Feng, Mary M; Baryla, Julia; Liu, Hong; Laurie, Gordon W; McKown, Robert L; Ashki, Negin; Bhayana, Dinesh; Hutnik, Cindy M L

2014-06-01

Benzalkonium chloride (BAK) is the most commonly found preservative in eye drops, and has been shown to cause ocular surface inflammation and toxicity. Lacritin is a human tear glycoprotein secreted from the lacrimal glands that has been found to be cytoprotective. This study was designed to determine if the presence of lacritin confers protection to a cultured human corneal epithelial (HCE) cell line, CRL-11515, and primary HCE cells after exposure to the ocular preservative agent BAK. Recombinant human lacritin was cloned into intein fusion vectors, expressed in E. coli, and purified on chitin beads and DEAE Sepharose. Metabolic curves were established using the MTT assay after exposure of sub-confluent CRL-11515 cells to BAK or lacritin. Western blot analysis of lipidated LC3 (LC3-II) provided a measure of autophagy in CRL-11515 cells exposed to lacritin and/or BAK. BAK reduced CRL-11515 cellular metabolic activity in a time- and dose-dependent manner. BAK-induced cellular stress was evident by elevated autophagy that increased with rising concentrations of BAK compared to control (p < 0.05). Lacritin increased HCE cell proliferation at an optimal dose of 1 nM. Preconditioning HCE cells with 1 nM lacritin for 24 h prior to BAK exposure significantly dampened levels of LC3-II (p < 0.05) and promoted a significant increase in cellular metabolic activity (p < 0.01) compared to BAK alone. These results suggest lacritin protects cultured HCE cells stressed with BAK. Lacritin may have the potential to be used as a topical adjunctive therapy in eyes chronically exposed to BAK.

Therapeutic effects of topical doxycycline in a benzalkonium chloride-induced mouse dry eye model.

PubMed

Zhang, Zhen; Yang, Wen-Zhao; Zhu, Zhen-Zhen; Hu, Qian-Qian; Chen, Yan-Feng; He, Hui; Chen, Yong-Xiong; Liu, Zu-Guo

2014-05-06

We investigated the therapeutic effects and underlying mechanisms of topical doxycycline in a benzalkonium chloride (BAC)-induced mouse dry eye model. Eye drops containing 0.025%, 0.1% doxycycline or solvent were administered to a BAC-induced dry eye model four times daily. The clinical evaluations, including tear break-up time (BUT), fluorescein staining, inflammatory index, and tear volume, were performed on days 0, 1, 4, 7, and 10. Global specimens were collected on day 10 and processed for immunofluorescent staining, TUNEL, and periodic acid-Schiff assay. The levels of inflammatory mediators in the corneas were determined by real-time PCR. The total and phosphorylated nuclear factor-κB (NF-κB) were detected by Western blot. Both 0.025% and 0.1% doxycycline treatments resulted in increased BUT, lower fluorescein staining scores, and inflammatory index on days 4, 7, and 10, while no significant change in tear volume was observed. The 0.1% doxycycline-treated group showed more improvements in decreasing fluorescein staining scores, increasing Ki-67-positive cells, and decreasing TUNEL- and keratin-10-positive cells than other groups. The mucin-filled goblet cells in conjunctivas were increased, and the expression of CD11b and levels of matrix metalloproteinase-9, IL-1β, IL-6, TNF-α, macrophage inflammatory protein-2, and cytokine-induced neutrophil chemoattractant in corneas were decreased in both doxycycline-treated groups. In addition, doxycycline significantly reduced the phosphorylation of NF-κB activated in the BAC-treated corneas. Topical doxycycline showed clinical improvements and alleviated ocular surface inflammation on BAC-induced mouse dry eye, suggesting a potential as an anti-inflammatory agent in the clinical treatment of dry eye.

Combination of exogenous cell transplantation and 5-HT{sub 4} receptor agonism induce endogenous enteric neural crest-derived cells in a rat hypoganglionosis model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Hui; Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi’an Jiaotong University, No 96, Yan Ta Xi Road, Xi’an 710061, Shaanxi; Zheng, Bai-Jun

Enteric neural crest-derived cells (ENCCs) can migrate into endogenous ganglia and differentiate into progeny cells, and have even partially rescued bowel function; however, poor reliability and limited functional recovery after ENCC transplantation have yet to be addressed. Here, we investigated the induction of endogenous ENCCs by combining exogenous ENCC transplantation with a 5-HT{sub 4} receptor agonist mosapride in a rat model of hypoganglionosis, established by benzalkonium chloride treatment. ENCCs, isolated from the gut of newborn rats, were labeled with a lentiviral eGFP reporter. ENCCs and rats were treated with the 5-HT{sub 4} receptor agonist/antagonist. The labeled ENCCs were then transplantedmore » into the muscular layer of benzalkonium chloride-treated colons. At given days post-intervention, colonic tissue samples were removed for histological analysis. ENCCs and neurons were detected by eGFP expression and immunoreactivity to p75{sup NTR} and peripherin, respectively. eGFP-positive ENCCs and neurons could survive and maintain levels of fluorescence after transplantation. With longer times post-intervention, the number of peripherin-positive cells gradually increased in all groups. Significantly more peripherin-positive cells were found following ENCCs plus mosapride treatment, compared with the other groups. These results show that exogenous ENCCs combined with the 5-HT{sub 4} receptor agonist effectively induced endogenous ENCCs proliferation and differentiation in a rat hypoganglionosis model. - Highlights: • Survival and differentiation of exogenous ENCCs in treated colons. • With longer times post-intervention, the number of ENCCs and their progeny cells gradually increased. • Exogenous ENCCs combined with the 5-HT4 receptor agonist ffectively induced ENCCs proliferation and differentiation.« less

Corneal neurotoxicity due to topical benzalkonium chloride.

PubMed

Sarkar, Joy; Chaudhary, Shweta; Namavari, Abed; Ozturk, Okan; Chang, Jin-Hong; Yco, Lisette; Sonawane, Snehal; Khanolkar, Vishakha; Hallak, Joelle; Jain, Sandeep

2012-04-06

The aim of this study was to determine and characterize the effect of topical application of benzalkonium chloride (BAK) on corneal nerves in vivo and in vitro. Thy1-YFP+ neurofluorescent mouse eyes were treated topically with vehicle or BAK (0.01% or 0.1%). Wide-field stereofluorescence microscopy was performed to sequentially image the treated corneas in vivo every week for 4 weeks, and changes in stromal nerve fiber density (NFD) and aqueous tear production were determined. Whole-mount immunofluorescence staining of corneas was performed with antibodies to axonopathy marker SMI-32. Western immunoblot analyses were performed on trigeminal ganglion and corneal lysates to determine abundance of proteins associated with neurotoxicity and regeneration. Compartmental culture of trigeminal ganglion neurons was performed in Campenot devices to determine whether BAK affects neurite outgrowth. BAK-treated corneas exhibited significantly reduced NFD and aqueous tear production, and increased inflammatory cell infiltration and fluorescein staining at 1 week (P < 0.05). These changes were most significant after 0.1% BAK treatment. The extent of inflammatory cell infiltration in the cornea showed a significant negative correlation with NFD. Sequential in vivo imaging of corneas showed two forms of BAK-induced neurotoxicity: reversible neurotoxicity characterized by axonopathy and recovery, and irreversible neurotoxicity characterized by nerve degeneration and regeneration. Increased abundance of beta III tubulin in corneal lysates confirmed regeneration. A dose-related significant reduction in neurites occurred after BAK addition to compartmental cultures of dissociated trigeminal ganglion cells. Although both BAK doses (0.0001% and 0.001%) reduced nerve fiber length, the reduction was significantly more with the higher dose (P < 0.001). Topical application of BAK to the eye causes corneal neurotoxicity, inflammation, and reduced aqueous tear production.

Anti-inflammatory effects of nitric oxide-releasing hydrocortisone NCX 1022, in a murine model of contact dermatitis.

PubMed

Hyun, Eric; Bolla, Manlio; Steinhoff, Martin; Wallace, John L; Soldato, Piero Del; Vergnolle, Nathalie

2004-11-01

1 The concept that nitric oxide (NO) release can be beneficial in inflammatory conditions has raised more attention in the recent years, particularly with the development of nitric oxide-releasing anti-inflammatory drugs. There is considerable evidence that NO is capable of enhancing the anti-inflammatory benefits of conventional anti-inflammatory drugs. 2 Since hydrocortisone is the most widely used anti-inflammatory drug for the treatment of skin inflammation, we compared the anti-inflammatory effects of hydrocortisone to an NO-releasing derivative of hydrocortisone, NCX 1022, in a murine model of irritant contact dermatitis, induced by epidermal application of benzalkonium chloride. 3 Topical pre- and post-treatment with NCX 1022 (3 nmol) in C57BL6 mice not only reduced ear oedema formation in a dose-dependent manner, but also was significantly more effective than the parent compound during the initial stages of inflammation (from 1 to 5 h). NCX 1022, but not hydrocortisone, significantly inhibited granulocyte recruitment (tissue myeloperoxidase activity). Histological samples of mouse ears treated with NCX 1022 showed significant reduction in both the number of infiltrated cells and disruption of the tissue architecture compared to hydrocortisone-treated tissues. 4 With intravital microscopy, we observed that both pre- and post-treatments with NCX 1022 were more effective than hydrocortisone in terms of inhibiting benzalkonium chloride-induced leukocyte adhesion to the endothelium, without affecting the flux of rolling leukocytes or venule diameter. 5 These results suggest that by releasing NO, NCX 1022 modulates one of the early events of skin inflammation: the recruitment of leukocytes to the site of inflammation. Overall, we have shown that NO-hydrocortisone provided faster and greater protective effects, reducing major inflammatory parameters (leukocyte adhesion and recruitment, oedema formation, tissue disruption) compared to its parental compound.

Tolerance development in Listeria monocytogenes-Escherichia coli dual-species biofilms after sublethal exposures to pronase-benzalkonium chloride combined treatments.

PubMed

Rodríguez-López, Pedro; Cabo, Marta López

2017-10-01

This study was designed to assess the effects that sublethal exposures to pronase (PRN) and benzalkonium chloride (BAC) combined treatments have on Listeria monocytogenes-Escherichia coli dual-species biofilms grown on stainless steel in terms of tolerance development (TD) to these compounds. Additionally, fluorescence microscopy was used to observe the changes of the biofilm structure. PRN-BAC exposure was carried out using three different approaches and TD was evaluated treating biofilms with a final 100 μg/ml PRN followed by 50 μg/ml BAC combined treatment. Results showed that exposure to PRN-BAC significantly decreased the number of adhered L. monocytogenes (P < 0.05), while E. coli counts remained generally unaltered. It was also demonstrated that the incorporation of recovery periods during sublethal exposures increased the tolerance of both species of the mixed biofilm to the final PRN-BAC treatment. Moreover, control biofilms became more resistant to PRN-BAC if longer incubation periods were used. Regardless of the treatment used, log reduction values were generally lower in L. monocytogenes compared to E. coli. Additionally, microscopy images showed an altered morphology produced by sublethal PRN-BAC in exposed L. monocytogenes-E. coli dual-species biofilms compared to control samples. Results also demonstrated that L. monocytogenes-E. coli dual-species biofilms are able to develop tolerance to PRN-BAC combined treatments depending on way they have been previously exposed. Moreover, they suggest that the generation of bacterial tolerance should be included as a parameter for sanitation procedures design. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of SofZia-preserved travoprost and benzalkonium chloride-preserved latanoprost on the ocular surface -- a multicentre randomized single-masked study.

PubMed

Aihara, Makoto; Oshima, Hiromi; Araie, Makoto

2013-02-01

To assess the effect of SofZia-preserved travoprost on ocular surface conditions in comparison with benzalkonium chloride (BAK)-preserved latanoprost. A prospective randomized multicentre single-masked comparative study. Patients with open-angle glaucoma or ocular hypertension who had been treated with BAK-preserved latanoprost 0.005% (Xalatan(®) ) monotherapy for at least 3 months. Patients were enrolled at 23 facilities. Patients were randomly divided into the X-X group, continuous use of Xalatan(®) , or the X-T group, switching from Xalatan(®) to SofZia-preserved travoprost 0.004% (TravatanZ(®) ), and followed for 3 months. The superficial punctate keratopathy (SPK), conjunctival epitheliopathy, hyperaemia, tear break-up time (TBUT) and intraocular pressure (IOP) were examined for each patient in a masked manner. Changes in the frequency of keratoconjunctival epitheliopathy were evaluated 3 months after study initiation. Intra- and intergroup comparisons of changes in SPK, conjunctival epitheliopathy, hyperaemia, TBUT and IOP were also carried out. Two hundred twenty patients participated and 215 completed the 3-month study. The frequency of keratoconjunctival epitheliopathy significantly decreased in the X-T group (p = 0.036) and the intergroup difference was also significant (p = 0.001). SPK scores and TBUT were significantly improved in the X-T group (p = 0.034, 0.049), also with significant intergroup differences in the cornea excluding the inferior area and TBUT. There were no significant intergroup differences in changes of the hyperaemia scores and the IOP reduction. Switching to SofZia-preserved travoprost after BAK-preserved latanoprost resulted in a lower incidence of keratoconjunctival epitheliopathy, especially in the cornea, with no clinically relevant changes in hyperaemia and IOP. © 2012 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

The effect of benzalkonium chloride additions to AH Plus sealer. Antimicrobial, physical and chemical properties.

PubMed

Arias-Moliz, M T; Ruiz-Linares, M; Cassar, G; Ferrer-Luque, C M; Baca, P; Ordinola-Zapata, R; Camilleri, J

2015-07-01

The aim of this study was to determine the antimicrobial and antibiofilm activities and physicochemical properties of AH Plus sealer mixed with different concentrations of benzalkonium chloride (BC). AH Plus was tested alone and mixed with 1%, 2% and 3% of BC. The antimicrobial and antibiofilm activities of the sealers against Enterococcus faecalis were evaluated by the direct contact test (DCT) and by confocal laser scanning microscopy, respectively. Setting time, flow and solubility were assessed according to ANSI/ADA specifications. Microhardness and contact angle tests were also performed. The chemical changes of the sealers were evaluated by X-ray diffraction analysis, and both Fourier transform infrared spectroscopy (FT-IR) and attenuated total reflectance Fourier transform infrared (ATR FT-IR). AH Plus+3% BC was the only sealer to promote total elimination of E. faecalis and the biovolume in this group was significantly lower than in the rest of the sealers (p>0.05). The physical properties of the sealers were according to the ANSI/ADA specifications. The microhardness decreased significantly when BC was added and a significant reduction in contact angle was obtained when incorporating 2% and 3% BC (p<0.05). No phase changes were observed with the modified sealers. The addition of 2% or higher concentrations BC to AH Plus showed antimicrobial and antibiofilm activities without affecting the properties specified in ANSI/ADA standards. However, additives to the root canal sealer altered other physical and chemical properties that are not commonly found in the literature to evaluate filling materials. The present study highlights that the antimicrobial properties of AH Plus can be significantly improved with the addition of BC. Testing beyond what is specified in standards may be indicated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Clinical audit examining the impact of benzalkonium chloride-free anti-glaucoma medications on patients with symptoms of ocular surface disease.

PubMed

Goldberg, Ivan; Graham, Stuart L; Crowston, Jonathan G; d'Mellow, Guy

2015-04-01

Ocular surface disease (OSD) is relatively common in glaucoma patients. OSD symptoms could be linked to prolonged exposure to preservatives in anti-glaucoma medications, especially benzalkonium chloride (BAK). The OBSERVE clinical audit was designed to track the impact of intraocular pressure lowering medications in patients with evidence of OSD to test the hypothesis that BAK-free anti-glaucoma preparations offer clinical advantages over BAK-containing products. Prospective clinical audit from March 2012 to April 2013, open to ophthalmologists practising in Australia. There were 375 patients enrolled, with a completion rate of 64%. The cohort was predominantly female (68%) with an average age of 71 years. Patients were screened for inclusion during a routine consultation. If eligible, they were enrolled. At the ophthalmologist's discretion, some patients were switched to BAK-free anti-glaucoma products. Data were collected via an online survey completed by the ophthalmologist during three appointments over a 16- to 30-week period for all patients. Intraocular pressure, tear-film breakup time, McMonnies Dry Eye Questionnaire score and reported lubricant use. Patients who switched to BAK-free preparations reported a significant fall in the use of lubricants (P = <0.001). Patients in both groups experienced a significant improvement in McMonnies Dry Eye Questionnaire score (P = <0.0001). The percentage of patients with low tear-film breakup time decreased significantly in both groups (P = 0.0001). There was no significant change in intraocular pressure from pre-study levels for either group (P = 0.105). BAK-free anti-glaucoma preparations were associated with a change in lubricant use, suggesting reduction in some OSD symptoms, but more research is needed. © 2014 Royal Australian and New Zealand College of Ophthalmologists.

Corneal Neurotoxicity Due to Topical Benzalkonium Chloride

PubMed Central

Sarkar, Joy; Chaudhary, Shweta; Namavari, Abed; Ozturk, Okan; Chang, Jin-Hong; Yco, Lisette; Sonawane, Snehal; Khanolkar, Vishakha; Hallak, Joelle; Jain, Sandeep

2012-01-01

Purpose. The aim of this study was to determine and characterize the effect of topical application of benzalkonium chloride (BAK) on corneal nerves in vivo and in vitro. Methods. Thy1-YFP+ neurofluorescent mouse eyes were treated topically with vehicle or BAK (0.01% or 0.1%). Wide-field stereofluorescence microscopy was performed to sequentially image the treated corneas in vivo every week for 4 weeks, and changes in stromal nerve fiber density (NFD) and aqueous tear production were determined. Whole-mount immunofluorescence staining of corneas was performed with antibodies to axonopathy marker SMI-32. Western immunoblot analyses were performed on trigeminal ganglion and corneal lysates to determine abundance of proteins associated with neurotoxicity and regeneration. Compartmental culture of trigeminal ganglion neurons was performed in Campenot devices to determine whether BAK affects neurite outgrowth. Results. BAK-treated corneas exhibited significantly reduced NFD and aqueous tear production, and increased inflammatory cell infiltration and fluorescein staining at 1 week (P < 0.05). These changes were most significant after 0.1% BAK treatment. The extent of inflammatory cell infiltration in the cornea showed a significant negative correlation with NFD. Sequential in vivo imaging of corneas showed two forms of BAK-induced neurotoxicity: reversible neurotoxicity characterized by axonopathy and recovery, and irreversible neurotoxicity characterized by nerve degeneration and regeneration. Increased abundance of beta III tubulin in corneal lysates confirmed regeneration. A dose-related significant reduction in neurites occurred after BAK addition to compartmental cultures of dissociated trigeminal ganglion cells. Although both BAK doses (0.0001% and 0.001%) reduced nerve fiber length, the reduction was significantly more with the higher dose (P < 0.001). Conclusion. Topical application of BAK to the eye causes corneal neurotoxicity, inflammation, and reduced aqueous tear production. PMID:22410563

Effect of intracolonic benzalkonium chloride on trinitrobenzene sulphonic acid-induced colitis in the rat.

PubMed

Miampamba, M; Parr, E J; McCafferty, D M; Wallace, J L; Sharkey, K A

1998-03-01

We investigated the effects of benzalkonium chloride (BAC) on trinitrobenzene sulphonic acid (TNBS)-induced colitis in rats. TNBS was administered intrarectally before and/or after BAC treatment. In the first study, the effects of treatment with BAC 6, 12 or 24 h after TNBS were examined. In the second study, animals were treated with BAC before, after or before and after TNBS, and were examined 7 days later. The severity of colitis was assessed by macroscopic and histological scoring of the colonic damage and by determination of colonic myeloperoxidase (MPO) activity. Macrophages and CD4+ and CD8+ T cells were examined by immunohistochemistry. When BAC was instilled into the colon 6, 12 or 24 h after TNBS, weight loss and macroscopic and histological features of the colon were similar to that of controls (TNBS alone). In contrast, MPO activity was significantly reduced in all three groups post-treated with BAC. In the groups examined 7 days after TNBS treatment, rats post-treated with BAC exhibited increased weight gain and significantly reduced macroscopic damage and MPO activity compared to the TNBS control group. Rats pre-treated with BAC exhibited less macroscopic damage of the colon than rats receiving only TNBS, but histological damage, MPO and weight gain were unchanged from TNBS controls. Immunohistochemistry revealed that BAC pre-treatment increased the numbers of macrophages and T cells in the colon. After TNBS treatment, macrophage accumulation was evident in the colon, but T cells were scarce. However, these cells were preserved or enhanced in the colonic mucosa in TNBS-treated rats that had been pre-treated with BAC. Treatment with BAC, particularly after induction of colitis, produces a significant reduction in the severity of tissue injury and inflammation through mechanisms that are not fully understood.

In vitro antibacterial and cytotoxicity assessments of an orthodontic bonding agent containing benzalkonium chloride.

PubMed

Saito, Kayo; Hayakawa, Tohru; Kawabata, Rihito; Meguro, Daijiro; Kasai, Kazutaka

2009-03-01

To assess the antibacterial activity and cytotoxicity of an orthodontic bonding material containing an antibacterial agent. Superbond C&B (4-methacryloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butyl borane [4-META/MMA-TBB]) resin was mixed with benzalkonium chloride (BAC) to obtain final BAC concentrations of 0.25%, 0.75%, 1.25%, 1.75%, 2.5%, and 5.0% (wt/ wt). Antibacterial activity against Streptococcus mutans and Streptococcus sobrinus was evaluated by soaking the BAC-resin in distilled water at 37 degrees C for periods of 30, 90, and 180 days. Antibacterial activity of the BAC-resin was measured by the disk diffusion method, and the inhibition zone around each sample was measured and recorded. For evaluation of cytotoxicity, BAC-resin samples were put into cell culture inserts placed above human gingival cells and were incubated at 37 degrees C for 1, 3, and 6 days. Cytotoxicity was assessed with a tetrazolium bromide reduction assay. The antibacterial activity of BAC-incorporated resin samples decreased significantly after immersion in water for 180 days, regardless of BAC concentration. The antibacterial activity of nonimmersed resin containing 0.25% or 1.75% BAC was comparable with that of 5.0% BAC-resin immersed for 180 days. In cytotoxicity tests, most cells died when exposed to resins containing 1.75%, 2.5%, and 5% BAC. No difference was observed between resins containing 0.25% and 0.75% BAC at 1, 3, and 6 days of culture. The addition of BAC to 4-META/MMA-TBB resin confers an antibacterial effect even after immersion in water, and 4-META/MMA-TBB resin containing 0.25% to 0.75% BAC has no significant cytotoxic effect.

Clinical study to know the efficacy of Amlexanox 5% with other topical Antiseptic, Analgesic and Anesthetic agents in treating minor RAS.

PubMed

Darshan, D D; Kumar, C N Vijay; Kumar, A D Manoj; Manikantan, N S; Balakrishnan, Dhanya; Uthkal, M P

2014-02-01

To evaluate the efficacy of topical antiinflammatory agent (amlexanox 5%), along with topical antiseptic, analgesic, and anesthetic agent (benzalkonium chloride 0.01%, choline salicylate 8.7% and lidocaine hydrochloride 2%), in promoting ulcer healing, decreasing ulcer size, erythema, pain and recurrence in minor RAS. A randomized control trial was conducted on 100 patients of RAS who fulfilled the inclusion criteria. The number, size, erythema and pain with the ulcer were recorded. Visual analogue scale (VAS) and erythema scale were used to record pain and erythema. 50 patients comprising the study group received anti inflammatory paste (amlexanox 5%) applied four times daily and the control group of 50 patients received topical antiseptic, analgesic, and anesthetic agent (benzalkonium chloride 0.01%, choline salicylate 8.7% and lidocaine hydrochloride 2%) paste, patients were evaluated after 3rd, 6th, 9th and on 30th, 60th day for recurrence. The study group had reduction in ulcer number, size; erythema, pain and frequency of ulcers during follow up. The healing period and recurrence of ulceration reduced in both the groups but the study group had significant reduction in 30th and 60th day follow up for recurrence of ulcers. Amlexanox 5% can reduce the frequency, duration and symptoms associated with the aphthous ulcers with no sideeffects attributed to the drug. How to cite the article: Darshan DD, Kumar CN, Kumar AD, Manikantan NS, Balakrishnan D, Uthkal MP. Clinical study to know the efficacy of Amlexanox 5% with other topical Antiseptic, Analgesic and Anesthetic agents in treating minor RAS. J Int Oral Health 2014;6(1);5-11.

Clinical study to know the efficacy of Amlexanox 5% with other topical Antiseptic, Analgesic and Anesthetic agents in treating minor RAS

PubMed Central

Darshan, D D; Kumar, C N Vijay; Kumar, A D Manoj; Manikantan, N S; Balakrishnan, Dhanya; Uthkal, M P

2014-01-01

Background: To evaluate the efficacy of topical antiinflammatory agent (amlexanox 5%), along with topical antiseptic, analgesic, and anesthetic agent (benzalkonium chloride 0.01%, choline salicylate 8.7% and lidocaine hydrochloride 2%), in promoting ulcer healing, decreasing ulcer size, erythema, pain and recurrence in minor RAS. Materials & Methods: A randomized control trial was conducted on 100 patients of RAS who fulfilled the inclusion criteria. The number, size, erythema and pain with the ulcer were recorded. Visual analogue scale (VAS) and erythema scale were used to record pain and erythema. 50 patients comprising the study group received anti inflammatory paste (amlexanox 5%) applied four times daily and the control group of 50 patients received topical antiseptic, analgesic, and anesthetic agent (benzalkonium chloride 0.01%, choline salicylate 8.7% and lidocaine hydrochloride 2%) paste, patients were evaluated after 3rd, 6th, 9th and on 30th, 60th day for recurrence. Results: The study group had reduction in ulcer number, size; erythema, pain and frequency of ulcers during follow up. The healing period and recurrence of ulceration reduced in both the groups but the study group had significant reduction in 30th and 60th day follow up for recurrence of ulcers. Conclusion: Amlexanox 5% can reduce the frequency, duration and symptoms associated with the aphthous ulcers with no sideeffects attributed to the drug. How to cite the article: Darshan DD, Kumar CN, Kumar AD, Manikantan NS, Balakrishnan D, Uthkal MP. Clinical study to know the efficacy of Amlexanox 5% with other topical Antiseptic, Analgesic and Anesthetic agents in treating minor RAS. J Int Oral Health 2014;6(1);5-11. PMID:24653596

Analysis of residual products in benzyl chloride used for the industrial synthesis of quaternary compounds by liquid chromatography with diode-array detection.

PubMed

Prieto-Blanco, M C; López-Mahía, P; Prada-Rodríguez, D

2009-02-01

In industrial and pharmaceutical processes, the study of residual products becomes essential to guarantee the quality of compounds and to eliminate or minimize toxic residual products. Knowledge about the origin of impurities (raw materials, processes, the contamination of industrial plants, etc.) is necessary in preventive treatment and in the control of a product's lifecycle. Benzyl chloride is used as raw material to synthesize several quaternary ammonium compounds, such as benzalkonium chloride, which may have pharmaceutical applications. Benzaldehyde, benzyl alcohol, toluene, chloro derivatives of toluene, and dibenzyl ether are compounds that may be found as impurities in technical benzyl chloride. We proposed a high-performance liquid chromatography method for the separation of these compounds, testing two stationary phases with different dimensions and particle sizes, with the application of photodiode array-detection. The linearity for four possible impurities (benzaldehyde, toluene, alpha,alpha-dichlorotoluene, and 2-chlorotoluene) ranged from 0.1 to 10 microg/mL, limits of detection from 11 to 34 ng/mL, and repeatability from 1% to 2.9% for a 0.3-1.2 microg/mL concentration range. The method was applied to samples of technical benzyl chloride, and alpha,alpha-dichlorotoluene and benzaldehyde were identified by spectral analysis and quantitated. The selection of benzyl chloride with lower levels of impurities is important to guarantee the reduction of residual products in further syntheses.

Virucidal agents in the eve of manorapid synergy®

PubMed Central

Galabov, Angel S.

2007-01-01

Virucidal agents are chemical substances that attack and inactivate viral particles outside the cell (virions). In general this is accomplished by damaging their protein shells (capsid) or the substance penetrates the core itself, where it destroys the genetic material. Damage to the virion structure is also possible. These agents are used not only for traditional surface disinfection or sterilization of blood, blood products, and other medicinal products as well as in antiviral chemotherapy. They have also been used in recent times for inactivation of viruses in foodstuffs, detergents or cosmetics. Below is given an overview of the data currently available on the performance of these substances when used for the latter applications (cleaning and cosmetics). These include: hydrogen peroxide, hypochlorites, cupric and ferric ions, per-acids ethanol, parachlorometaxylenol in a sodium C14-16 olefin sulfonate, glutaraldehyde, quaternary ammonium salts, chlorhexidine and chlorhexidine gluconate, curdline sulphate, glycerol, lipids, azodicarbonamide, cicloxolone sodium, dichlorisocyanuric acid (sodium salt), benzalkonium salts, disulfate benzamides and benzisothiazolones, congo red, ascorbic acid, nonoxynol-9, para-aminobenzoic acid, bis(monosuccinamide) derivative of p,p’-bis(2-aminoethyl) diphenlyi-C60) (fullerene). merocyanine, benzoporphyrin derivative monoacid ring A, rose bengal, hypericin, hypocrellin A, anthraquinones extracted from plants, sulfonated anthraquinones and other anthraquinone derivatives gramicidine, gossypol, garlic (Allium sativum) extract and its components: ajoene, diallyl thiosulfinate (allicin), allyl methyl thioulfinate, methyl allyl thiosulfinate, extracts of ledium, motherworth, celandine, black currant, coaberry and bilberry, extract of Cordia salicifolia, steam distillate from Houttuynia cordata (Saururaceae) and its component, 5,6,7-trimethoxyflavone from Calicarpa japonica, isoscullarein (5,7,8,4’-tetrahydroxyflavone) from Scutellaria baikalensis and isoscutellarein-8-methylether, alkaloids and phytosteryl ester compounds. PMID:20200679

Sustained release ophthalmic formulations of pilocarpine.

PubMed

Deshpande, S G; Shirolkar, S

1989-03-01

The bioavailability of drugs from conventional ophthalmic formulations is low. To optimize the therapy, sustained release ophthalmic dosage forms are warranted. Hydrogels such as sodium-carboxymethyl cellulose, hydroxypropylmethyl cellulose, Carbopol-940, Carbopol-941 and Lutrol-FC-127 increase the duration of action of various drugs. Gels containing pilocarpine were prepared and evaluated by measuring the intensity and duration of miotic response in albino rabbits. Carbopol-940 gels, being the best of those used, were studied further for the effect of its concentration and of additives (benzalkonium chloride, phenylmercuric nitrate, chlorbutol and disodium edetate), autoclaving at 121 degrees C for 30 min and irradiation with gamma rays (2.5 Mrad), on the end product.

Effectiveness of a nonrinse, alcohol-free antiseptic hand wash.

PubMed

Moadab, A; Rupley, K F; Wadhams, P

2001-06-01

This study evaluated the efficacy of a novel surfactant, allantoin, and benzalkonium chloride hand sanitizer using the US Food and Drug Administration's method for testing antiseptic hand washes that podiatric physicians and other health-care personnel use. The alcohol-free product, HandClens, was compared with an alcohol-based product, Purell. Independent researchers from the California College of Podiatric Medicine conducted the study using 40 volunteer students from the class of 2001. The results show that HandClens outperformed Purell and met the regulatory requirements for a hand sanitizer. Purell failed as an antimicrobial hand wash and was less effective than a control soap used in the study.

Direct effect of chlorine dioxide, zinc chloride and chlorhexidine solution on the gaseous volatile sulfur compounds.

PubMed

Kim, Ju-Sik; Park, Ji-Woon; Kim, Dae-Jung; Kim, Young-Ku; Lee, Jeong-Yun

2014-11-01

This study focused on the ability of aqueous anti-volatile-sulfur-compound (VSC) solutions to eliminate gaseous VSCs by direct contact in a sealed space to describe possible mode of action of anti-VSC agents. Twenty milliliters of each experimental solution, 0.16% sodium chlorite, 0.25% zinc chloride, 0.1% chlorhexidine and distilled water, was injected into a Teflon bag containing mixed VSCs, hydrogen sulfide, methyl mercaptan and dimethyl sulfide and mixed vigorously for 30 s. The VSC concentration was measured by gas chromatography before, immediately after, 30 min and 60 min after mixing. The sodium chlorite solution reduced the VSC concentration remarkably. After mixing, nearly all VSCs were eliminated immediately and no VSCs were detected at 30 and 60 min post-mixing. However, in the other solutions, the VSC concentration decreased by ∼30% immediately after mixing and there was no further decrease. The results suggest that sodium chlorite solution has the effect of eliminating gaseous VSCs directly. This must be because it can release chlorine dioxide gas which can react directly with gaseous VSCs. In the case of other solutions that have been proved to be effective to reduce halitosis clinically, it can be proposed that their anti-VSC effect is less likely due to the direct chemical elimination of gaseous VSCs in the mouth.

[Preservatives in ophthalmology].

PubMed

Messmer, E M

2012-11-01

Preservatives are a legal requirement for eye drops in multidose containers. Moreover, they are necessary for stabilization and intraocular penetration for a number of ophthalmic preparations. Most preservatives act in a relatively unspecific manner as detergents or by oxidative mechanisms and thereby cause side effects at the ocular surface. They may also affect the lens, trabecular meshwork and the retina. Benzalkonium chloride is the most commonly used preservative in ophthalmology and is more toxic than other or newer preservatives, such as polyquaternium-1 (Polyquad), sodium perborate, oxychloro-complex (Purite®) and SofZia. Preservative-free topical medication is highly recommended for patients with ocular surface disease, frequent eye drop administration, proven allergy to preservatives and contact lens wear.

Personal care product preservatives: risk assessment and mixture toxicities with an industrial wastewater.

PubMed

Carbajo, Jose B; Perdigón-Melón, Jose A; Petre, Alice L; Rosal, Roberto; Letón, Pedro; García-Calvo, Eloy

2015-04-01

The aquatic toxicity of eight preservatives frequently used in personal care products (PCPs) (iodopropynyl butylcarbamate, bronopol, diazolidinyl urea, benzalkonium chloride, zinc pyrithione, propylparaben, triclosan and a mixture of methylchloroisothiazolinone and methylisothiazolinone) was assessed by means of two different approaches: a battery of bioassays composed of single species tests of bacteria (Vibrio fischeri and Pseudomonas putida) and protozoa (Tetrahymena thermophila), and a whole biological community resazurin-based assay using activated sludge. The tested preservatives showed considerable toxicity in the studied bioassays, but with a marked difference in potency. In fact, all biocides except propylparaben and diazolidinyl urea had EC50 values lower than 1 mg L(-1) in at least one assay. Risk quotients for zinc pyrithione, benzalkonium chloride, iodopropynyl butylcarbamate and triclosan as well as the mixture of the studied preservatives exceeded 1, indicating a potential risk for the process performance and efficiency of municipal sewage treatment plants (STPs). These four single biocides explained more than 95% of the preservative mixture risk in all bioassays. Each individual preservative was also tested in combination with an industrial wastewater (IWW) from a cosmetics manufacturing facility. The toxicity assessment was performed on binary mixtures (preservative + IWW) and carried out using the median-effect principle, which is a special case of the concept of Concentration Addition (CA). Almost 70% of all experiments resulted in EC50 values within a factor of 2 of the values predicted by the median-effect principle (CI values between 0.5 and 2). The rest of the mixtures whose toxicity was mispredicted by CA were assessed with the alternative concept of Independent Action (IA), which showed higher predictive power for the biological community assay. Therefore, the concept used to accurately predict the toxicity of mixtures of a preservative with a complex industrial wastewater depends on degree of biological complexity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ecotoxicity of disinfectant benzalkonium chloride and its mixture with antineoplastic drug 5-fluorouracil towards alga Pseudokirchneriella subcapitata

PubMed Central

Ženko, Maja

2018-01-01

Background Benzalkonium chloride (BAC) is one of the most common ingredients of the disinfectants. It is commonly detected in surface and wastewaters where it can interact with the residues of pharmaceuticals that are also common wastewater pollutants. Among the latter, the residues of antineoplastic drugs are of particular concern as recent studies showed that they can induce adverse effect in aquatic organisms at environmentally relevant concentrations. Methods Ecotoxicity of BAC as an individual compound and in a binary mixture with an antineoplastic drug 5-fluorouracil (5-FU) was determined towards alga Pseudokirchneriella subcapitata, a representative of primary producers. The toxicity of the BAC+5-FU binary mixture was predicted by the two basic models: concentration addition (CA) and independent action (IA), and compared to the experimentally determined toxicity. Additionally combination index (CI) was calculated to determine the type of interaction. Results After 72 h exposure to BAC a concentration dependent growth inhibition of P. subcapitata was observed with an EC50 0.255 mg/L. Comparing the predicted no effect concentration to the measured concentrations in the surface waters indicate that BAC at current applications and occurrence in aquatic environment may affect algal populations. The measured toxicity of the mixture was higher from the predicted and calculated CI confirmed synergistic effect on the inhibition of algal growth, at least at EC50 concentration. The observed synergism may have impact on the overall toxicity of wastewaters, whereas it is less likely for general environments because the concentrations of 5-FU are several orders of magnitude lower from its predicted no effect concentration. Discussion These results indicate that combined effects of mixtures of disinfectants and antineoplastic drugs should be considered in particular when dealing with environmental risk assessment as well as the management of municipal and hospital wastewaters. PMID:29938131

A new safety concern for glaucoma treatment demonstrated by mass spectrometry imaging of benzalkonium chloride distribution in the eye, an experimental study in rabbits.

PubMed

Brignole-Baudouin, Françoise; Desbenoit, Nicolas; Hamm, Gregory; Liang, Hong; Both, Jean-Pierre; Brunelle, Alain; Fournier, Isabelle; Guerineau, Vincent; Legouffe, Raphael; Stauber, Jonathan; Touboul, David; Wisztorski, Maxence; Salzet, Michel; Laprevote, Olivier; Baudouin, Christophe

2012-01-01

We investigated in a rabbit model, the eye distribution of topically instilled benzalkonium_(BAK) chloride a commonly used preservative in eye drops using mass spectrometry imaging. Three groups of three New Zealand rabbits each were used: a control one without instillation, one receiving 0.01%BAK twice a day for 5 months and one with 0.2%BAK one drop a day for 1 month. After sacrifice, eyes were embedded and frozen in tragacanth gum. Serial cryosections were alternately deposited on glass slides for histological (hematoxylin-eosin staining) and immunohistological controls (CD45, RLA-DR and vimentin for inflammatory cell infiltration as well as vimentin for Müller glial cell activation) and ITO or stainless steel plates for MSI experiments using Matrix-assisted laser desorption ionization time-of-flight. The MSI results were confirmed by a round-robin study on several adjacent sections conducted in two different laboratories using different sample preparation methods, mass spectrometers and data analysis softwares. BAK was shown to penetrate healthy eyes even after a short duration and was not only detected on the ocular surface structures, but also in deeper tissues, especially in sensitive areas involved in glaucoma pathophysiology, such as the trabecular meshwork and the optic nerve areas, as confirmed by images with histological stainings. CD45-, RLA-DR- and vimentin-positive cells increased in treated eyes. Vimentin was found only in the inner layer of retina in normal eyes and increased in all retinal layers in treated eyes, confirming an activation response to a cell stress. This ocular toxicological study confirms the presence of BAK preservative in ocular surface structures as well as in deeper structures involved in glaucoma disease. The inflammatory cell infiltration and Müller glial cell activation confirmed the deleterious effect of BAK. Although these results were obtained in animals, they highlight the importance of the safety-first principle for the treatment of glaucoma patients.

Therapeutic Effects of Sodium Hyaluronate on Ocular Surface Damage Induced by Benzalkonium Chloride Preserved Anti-glaucoma Medications

PubMed Central

Liu, Xing; Yu, Fen-Fen; Zhong, Yi-Min; Guo, Xin-Xing; Mao, Zhen

2015-01-01

Background: Long-term use of benzalkonium chloride (BAC)-preserved drugs is often associated with ocular surface toxicity. Ocular surface symptoms had a substantial impact on the glaucoma patients’ quality of life and compliance. This study aimed to investigate the effects of sodium hyaluronate (SH) on ocular surface toxicity induced by BAC-preserved anti-glaucoma medications treatment. Methods: Fifty-eight patients (101 eyes), who received topical BAC-preserved anti-glaucoma medications treatment and met the severe dry eye criteria, were included in the analysis. All patients were maintained the original topical anti-glaucoma treatment. In the SH-treated group (56 eyes), unpreserved 0.3% SH eye drops were administered with 3 times daily for 90 days. In the control group (55 eyes), phosphate-buffered saline were administered with 3 times daily for 90 days. Ocular Surface Disease Index (OSDI) questionnaire, break-up time (BUT) test, corneal fluorescein staining, corneal and conjunctival rose Bengal staining, Schirmer test, and conjunctiva impression cytology were performed sequentially on days 0 and 91. Results: Compared with the control group, SH-treated group showed decrease in OSDI scores (Kruskal-Wallis test: H = 38.668, P < 0.001), fluorescein and rose Bengal scores (Wilcoxon signed-ranks test: z = −3.843, P < 0.001, and z = −3.508, P < 0.001, respectively), increase in tear film BUT (t-test: t = −10.994, P < 0.001) and aqueous tear production (t-test: t = −10.328, P < 0.001) on day 91. The goblet cell density was increased (t-test: t = −9.981, P < 0.001), and the morphology of the conjunctival epithelium were also improved after SH treatment. Conclusions: SH significantly improved both symptoms and signs of ocular surface damage in patients with BAC-preserved anti-glaucoma medications treatment. SH could be proposed as a new attempt to reduce ocular surface toxicity, and alleviate symptoms of ocular surface damage in BAC-preserved anti-glaucoma medications treatment. PMID:26365960

A New Safety Concern for Glaucoma Treatment Demonstrated by Mass Spectrometry Imaging of Benzalkonium Chloride Distribution in the Eye, an Experimental Study in Rabbits

PubMed Central

Brignole-Baudouin, Françoise; Desbenoit, Nicolas; Hamm, Gregory; Liang, Hong; Both, Jean-Pierre; Brunelle, Alain; Fournier, Isabelle; Guerineau, Vincent; Legouffe, Raphael; Stauber, Jonathan; Touboul, David; Wisztorski, Maxence; Salzet, Michel; Laprevote, Olivier; Baudouin, Christophe

2012-01-01

We investigated in a rabbit model, the eye distribution of topically instilled benzalkonium_(BAK) chloride a commonly used preservative in eye drops using mass spectrometry imaging. Three groups of three New Zealand rabbits each were used: a control one without instillation, one receiving 0.01%BAK twice a day for 5 months and one with 0.2%BAK one drop a day for 1 month. After sacrifice, eyes were embedded and frozen in tragacanth gum. Serial cryosections were alternately deposited on glass slides for histological (hematoxylin-eosin staining) and immunohistological controls (CD45, RLA-DR and vimentin for inflammatory cell infiltration as well as vimentin for Müller glial cell activation) and ITO or stainless steel plates for MSI experiments using Matrix-assisted laser desorption ionization time-of-flight. The MSI results were confirmed by a round-robin study on several adjacent sections conducted in two different laboratories using different sample preparation methods, mass spectrometers and data analysis softwares. BAK was shown to penetrate healthy eyes even after a short duration and was not only detected on the ocular surface structures, but also in deeper tissues, especially in sensitive areas involved in glaucoma pathophysiology, such as the trabecular meshwork and the optic nerve areas, as confirmed by images with histological stainings. CD45-, RLA-DR- and vimentin-positive cells increased in treated eyes. Vimentin was found only in the inner layer of retina in normal eyes and increased in all retinal layers in treated eyes, confirming an activation response to a cell stress. This ocular toxicological study confirms the presence of BAK preservative in ocular surface structures as well as in deeper structures involved in glaucoma disease. The inflammatory cell infiltration and Müller glial cell activation confirmed the deleterious effect of BAK. Although these results were obtained in animals, they highlight the importance of the safety-first principle for the treatment of glaucoma patients. PMID:23209668

Travoprost 0.004%/timolol 0.5%-fixed combination with and without benzalkonium chloride: a prospective, randomized, doubled-masked comparison of safety and efficacy

PubMed Central

Kitazawa, Y; Smith, P; Sasaki, N; Kotake, S; Bae, K; Iwamoto, Y

2011-01-01

Purpose The purpose of this study is to compare the safety and intraocular pressure (IOP)-lowering efficacy of travoprost/timolol in a benzalkonium chloride (BAK)-free fixed combination preserved with polyquaternium-1 (TRA/TIM BAK-free), with travoprost/timolol-fixed combination preserved with BAK (TRA/TIM), in patients with open-angle glaucoma or ocular hypertension. Methods In this prospective randomized controlled trial, subjects with IOP of at least 22 mm Hg in one or both eyes at 0900 h, and IOP of at least 21 mm Hg in one or both eyes at 1100 h and 1600 h at two eligibility visits were randomly assigned to receive either TRA/TIM BAK-free (n=195) or TRA/TIM (n=193), dosed once daily in the morning (0900 h) for 6 weeks. IOP was assessed at 0900 h, 1100 h, and 1600 h at each scheduled visit (baseline, 2 and 6 weeks after randomization). Results Mean IOP reduction across all visits and time points was 8.0 mm Hg in the TRA/TIM BAK-free group and 8.4 mm Hg in the TRA/TIM group (P=0.0943). The difference in mean IOP between groups ranged from 0.2 to 0.7 mm Hg across visits and time points, with a mean pooled difference of 0.4 mm Hg (95% CI: −0.1 to 0.8), demonstrating equivalence of the two formulations. The most common drug-related adverse event was hyperemia of the eye (ocular hyperemia and conjunctival hyperemia combined), occurring in 11.8% of the TRA/TIM BAK-free group and 13.0% of the TRA/TIM group. Conclusion Travoprost/timolol BAK-free demonstrated equivalence to travoprost/timolol preserved with BAK in efficacy. No clinically relevant differences in the safety profiles of travoprost/timolol BAK-free and travoprost/timolol preserved with BAK were identified. PMID:21701528

Comparison of a travoprost BAK-free formulation preserved with polyquaternium-1 with BAK-preserved travoprost in ocular hypertension or open-angle glaucoma.

PubMed

Gandolfi, Stefano; Paredes, Tania; Goldberg, Ivan; Coote, Michael; Wells, Anthony; Volksone, Lasma; Pillai, Manju R; Stalmans, Ingeborg; Denis, Philippe

2012-01-01

To demonstrate that the intraocular pressure (IOP)-lowering effect of travoprost 0.004% preserved with polyquaternium-1 (travoprost benzalkonium chloride [BAK]-free) is non-inferior to that of travoprost 0.004% preserved with benzalkonium chloride (travoprost BAK) in patients with ocular hypertension or open-angle glaucoma. A total of 371 patients randomly received travoprost BAK-free (n=185) or travoprost BAK (n=186) dosed once daily in the evening for 3 months. Patients were evaluated at 9 am, 11 AM, and 4 PM at baseline, weeks 2 and 6, and month 3. Intraocular pressure was also evaluated 36 and 60 hours after the month 3 visit. Travoprost BAK-free is non-inferior to travoprost BAK. The 95% upper confidence limits for the difference in mean IOP at month 3 (primary efficacy) were 0.5 mmHg, 0.6 mmHg, and 0.5 mmHg, at 9 AM, 11 AM, and 4 PM, respectively. Mean IOP reductions from baseline ranged from 7.6 to 8.7 mmHg in the travoprost BAK-free group and from 7.7 to 9.2 mmHg in the travoprost BAK group. At 36 and 60 hours after the last dose, mean IOP remained 6.8 mmHg and 5.7 mmHg below baseline in the travoprost BAK-free group, vs 7.3 mmHg and 6.0 mmHg in the travoprost BAK group, respectively. The safety profile of travoprost BAK-free was similar to that of travoprost BAK. Travoprost BAK-free safely and effectively lowers IOP in eyes with open-angle glaucoma or ocular hypertension. This BAK-free formulation has comparable safety, efficacy, and duration of IOP-lowering effect to travoprost preserved with BAK. Travoprost BAK-free is an effective option for IOP reduction while avoiding BAK exposure.

Travoprost 0.004%/timolol 0.5%-fixed combination with and without benzalkonium chloride: a prospective, randomized, doubled-masked comparison of safety and efficacy.

PubMed

Kitazawa, Y; Smith, P; Sasaki, N; Kotake, S; Bae, K; Iwamoto, Y

2011-09-01

The purpose of this study is to compare the safety and intraocular pressure (IOP)-lowering efficacy of travoprost/timolol in a benzalkonium chloride (BAK)-free fixed combination preserved with polyquaternium-1 (TRA/TIM BAK-free), with travoprost/timolol-fixed combination preserved with BAK (TRA/TIM), in patients with open-angle glaucoma or ocular hypertension. In this prospective randomized controlled trial, subjects with IOP of at least 22  mm Hg in one or both eyes at 0900  h, and IOP of at least 21  mm Hg in one or both eyes at 1100  h and 1600  h at two eligibility visits were randomly assigned to receive either TRA/TIM BAK-free (n=195) or TRA/TIM (n=193), dosed once daily in the morning (0900  h) for 6 weeks. IOP was assessed at 0900  h, 1100  h, and 1600  h at each scheduled visit (baseline, 2 and 6 weeks after randomization). Mean IOP reduction across all visits and time points was 8.0  mm Hg in the TRA/TIM BAK-free group and 8.4  mm Hg in the TRA/TIM group (P=0.0943). The difference in mean IOP between groups ranged from 0.2 to 0.7  mm Hg across visits and time points, with a mean pooled difference of 0.4  mm Hg (95% CI: -0.1 to 0.8), demonstrating equivalence of the two formulations. The most common drug-related adverse event was hyperemia of the eye (ocular hyperemia and conjunctival hyperemia combined), occurring in 11.8% of the TRA/TIM BAK-free group and 13.0% of the TRA/TIM group. Travoprost/timolol BAK-free demonstrated equivalence to travoprost/timolol preserved with BAK in efficacy. No clinically relevant differences in the safety profiles of travoprost/timolol BAK-free and travoprost/timolol preserved with BAK were identified.

Soft antimicrobial agents: synthesis and activity of labile environmentally friendly long chain quaternary ammonium compounds.

PubMed

Thorsteinsson, Thorsteinn; Másson, Már; Kristinsson, Karl G; Hjálmarsdóttir, Martha A; Hilmarsson, Hilmar; Loftsson, Thorsteinn

2003-09-11

A series of soft quaternary ammonium antimicrobial agents, which are analogues to currently used quaternary ammonium preservatives such as cetyl pyridinium chloride and benzalkonium chloride, were synthesized. These soft analogues consist of long alkyl chain connected to a polar headgroup via chemically labile spacer group. They are characterized by facile nonenzymatic and enzymatic degradation to form their original nontoxic building blocks. However, their chemical stability has to be adequate in order for them to have antimicrobial effects. Stability studies and antibacterial and antiviral activity measurements revealed relationship between activity, lipophilicity, and stability. Their minimum inhibitory concentration (MIC) was as low as 1 microg/mL, and their viral reduction was in some cases greater than 6.7 log. The structure-activity studies demonstrate that the bioactive compounds (i.e., MIC for Gram-positive bacteria of <10 microg/mL) have an alkyl chain length between 12 and 18 carbon atoms, with a polar headgroup preferably of a small quaternary ammonium group, and their acquired inactivation half-life must be greater than 3 h at 60 degrees C.

How to deal with morning bad breath: A randomized, crossover clinical trial.

PubMed

Oliveira-Neto, Jeronimo M; Sato, Sandra; Pedrazzi, Vinícius

2013-11-01

The absence of a protocol for the treatment of halitosis has led us to compare mouthrinses with mechanical oral hygiene procedures for treating morning breath by employing a hand-held sulfide monitor. To compare the efficacy of five modalities of treatment for controlling morning halitosis in subjects with no dental or periodontal disease. This is a five-period, randomized, crossover clinical trial. Twenty volunteers were randomly assigned to the trial. Testing involved the use of a conventional tongue scraper, a tongue scraper joined to the back of a toothbrush's head, two mouthrinses (0.05% cetylpyridinium chloride and 0.12% chlorhexidine digluconate) and a soft-bristled toothbrush and fluoride toothpaste for practicing oral hygiene. Data analysis was performed using SPSS version 17 for Windows and NCSS 2007 software (P < 0.05). The products and the periods were compared with each other using the Friedman's test. When significant differences (P < 0.05) were determined, the products and periods were compared in pairs by using the Wilcoxon's test and by adjusting the original significance level (0.05) for multiple comparisons by using the Bonferroni's method. The toothbrush's tongue scraper was able to significantly reduce bad breath for up to 2 h. Chlorhexidine reduced bad breath only at the end of the second hour, an effect that lasted for 3 h. Mechanical tongue cleaning was able to immediately reduce bad breath for a short period, whereas chlorhexidine and mechanical oral hygiene reduced bad breath for longer periods, achieving the best results against morning breath.

Flammability of topical preparations and surgical dressings in cutaneous and laser surgery: a controlled simulation study.

PubMed

Arefiev, Katharine; Warycha, Melanie; Whiting, Dennis; Alam, Murad

2012-10-01

Surgical fires are a rare, but serious complication of dermatologic procedures involving electrosurgical and laser devices. Given the lack of data regarding basic fire safety principles, many dermatologists remain unaware of this potential risk. We evaluated the flammability of topical preparations and surgical drapes commonly encountered in the immediate operative field during cutaneous and laser surgery. Surgical dressings, drapes, and pork belly skin were examined for fire risk upon exposure to isopropyl alcohol, chlorhexidine gluconate, and aluminum chloride under dry, saturated, and damp conditions. Both electrosurgery and a carbon-dioxide laser were used as ignition sources. At least some char was observed in 86 of 126 simulated conditions (68%). Flames occurred in 2 test conditions: dry underpad drapes and cotton balls exposed to the carbon-dioxide laser. In general, drapes and dressings dampened or saturated with isopropyl alcohol failed to ignite with electrofulguration or electrodessication, although sparks and moderate char developed on pork belly skin and the underpad drape. Materials dampened or saturated with chlorhexidine gluconate, which contains isopropyl alcohol, generated less smoke and char compared with materials exposed to aluminum chloride, which does not contain alcohol. Future studies may assess the flammability of materials in the setting of oxygen supplementation. In common cutaneous surgical environments, electrosurgery or ablative laser may lead to char and rarely to fire. Char may be seen in up to two thirds of simulated conditions, and in a minute proportion of conditions, fire is observed. Copyright © 2012 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Surface treatment influences electrochemical stability of cpTi exposed to mouthwashes.

PubMed

Beline, Thamara; Garcia, Camila S; Ogawa, Erika S; Marques, Isabella S V; Matos, Adaias O; Sukotjo, Cortino; Mathew, Mathew T; Mesquita, Marcelo F; Consani, Rafael X; Barão, Valentim A R

2016-02-01

The role of surface treatment on the electrochemical behavior of commercially pure titanium (cpTi) exposed to mouthwashes was tested. Seventy-five disks were divided into 15 groups according to surface treatment (machined, sand blasted with Al2O3, and acid etched) and electrolyte solution (artificial saliva — control, 0.12% chlorhexidine digluconate, 0.05% cetylpyridinium chloride, 0.2% sodium fluoride, and 1.5% hydrogen peroxide) (n = 5). Open-circuit-potential and electrochemical impedance spectroscopy were conducted at baseline and after 7 and 14 days of immersion in each solution. Potentiodynamic test and total weight loss of disks were performed after 14 days of immersion. Scanning electron microscopy, energy dispersive spectroscopy, white light interferometry and profilometry were conducted for surface characterization before and after the electrochemical tests. Sandblasting promoted the lowest polarization resistance (Rp) (P b .0001) and the highest capacitance (CPE) (P b .006), corrosion current density (Icorr) and corrosion rate (P b .0001). In contrast, acid etching increased Rp and reduced CPE, independent to the mouthwash; while hydrogen peroxide reduced Rp (P b .008) and increased Icorr and corrosion rate (P b .0001). The highest CPE values were found for hydrogen peroxide and 0.2% sodium fluoride. Immersion for longer period improved the electrochemical stability of cpTi (P b .05). In conclusion, acid etching enhanced the electrochemical stability of cpTi. Hydrogen peroxide and sodium fluoride reduced the resistance to corrosion of cpTi, independent to the surface treatment. Chlorhexidine gluconate and cetylpyridinium chloride did not alter the corrosive behavior of cpTi.

Ion-pair in-tube solid-phase microextraction and capillary liquid chromatography using a titania-based column: application to the specific lauralkonium chloride determination in water.

PubMed

Prieto-Blanco, M C; Moliner-Martínez, Y; López-Mahía, P; Campíns-Falcó, P

2012-07-27

A quick, miniaturized and on-line method has been developed for the determination in water of the predominant homologue of benzalkonium chloride, dodecyl dimethyl benzyl ammonium chloride or lauralkonium chloride (C(12)-BAK). The method is based on the formation of an ion-pair in both in-tube solid-phase microextraction (IT-SPME) and capillary liquid chromatography. The IT-SPME optimization required the study of the length and nature of the stationary phase of capillary and the processed sample volume. Because to the surfactant character of the analyte both, the extracting and replacing solvents, have played a decisive role in the IT-SPME optimized procedure. Conditioning the capillary with the mobile phase which contains the counter ion (acetate), using an organic additive (tetrabutylammonium chloride) added to the sample and a mixture water/methanol as replacing solvent (processed just before the valve is switched to the inject position), allowed to obtain good precision of the retention time and a narrow peak for C(12)-BAK. A reversed-phase capillary based TiO(2) column and a mobile phase containing ammonium acetate at pH 5.0 for controlling the interactions of cationic surfactant with titania surface were proposed. The optimized procedure provided adequate linearity, accuracy and precision at the concentrations interval of 1.5-300 μg L(-1) .The limit of detection (LOD) was 0.5 μg L(-1) using diode array detection (DAD). The applicability of proposed IT-SPME-capillary LC method has been assessed in several water samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Spectral domain optical coherence tomography in Celestone® retinal toxicity.

PubMed

Marticorena-Álvarez, P; González Guijarro, J

2016-03-01

After inadvertent intravitreal injection of Celestone® (betamethasone sodium phosphate and acetate, benzalkonium chloride) in a patient, the macular spectral domain optical coherence tomography (SD-OCT) images showed hyper-reflectivity, thinning, and irregular spikes in the inner retinal layers. These early findings could explain the toxic secondary anatomical changes due to the drug itself and/or to its excipients. Late and permanent SD-OCT findings included changes in the ellipsoid zone and cystic-like spaces. In this case, SD-OCT images can help to better understand the pathophysiology of the retinal damage and to diagnose the associated complications, providing information with prognostic value. Copyright © 2015 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

Copper and Quaternary Ammonium Cations Exert Synergistic Bactericidal and Antibiofilm Activity against Pseudomonas aeruginosa▿

PubMed Central

Harrison, Joe J.; Turner, Raymond J.; Joo, Daniel A.; Stan, Michelle A.; Chan, Catherine S.; Allan, Nick D.; Vrionis, Helen A.; Olson, Merle E.; Ceri, Howard

2008-01-01

Biofilms are slimy aggregates of microbes that are likely responsible for many chronic infections as well as for contamination of clinical and industrial environments. Pseudomonas aeruginosa is a prevalent hospital pathogen that is well known for its ability to form biofilms that are recalcitrant to many different antimicrobial treatments. We have devised a high-throughput method for testing combinations of antimicrobials for synergistic activity against biofilms, including those formed by P. aeruginosa. This approach was used to look for changes in biofilm susceptibility to various biocides when these agents were combined with metal ions. This process identified that Cu2+ works synergistically with quaternary ammonium compounds (QACs; specifically benzalkonium chloride, cetalkonium chloride, cetylpyridinium chloride, myristalkonium chloride, and Polycide) to kill P. aeruginosa biofilms. In some cases, adding Cu2+ to QACs resulted in a 128-fold decrease in the biofilm minimum bactericidal concentration compared to that for single-agent treatments. In combination, these agents retained broad-spectrum antimicrobial activity that also eradicated biofilms of Escherichia coli, Staphylococcus aureus, Salmonella enterica serovar Cholerasuis, and Pseudomonas fluorescens. To investigate the mechanism of action, isothermal titration calorimetry was used to show that Cu2+ and QACs do not interact in aqueous solutions, suggesting that each agent exerts microbiological toxicity through independent biochemical routes. Additionally, Cu2+ and QACs, both alone and in combination, reduced the activity of nitrate reductases, which are enzymes that are important for normal biofilm growth. Collectively, the results of this study indicate that Cu2+ and QACs are effective combinations of antimicrobials that may be used to kill bacterial biofilms. PMID:18519726

How to deal with morning bad breath: A randomized, crossover clinical trial

PubMed Central

Oliveira-Neto, Jeronimo M.; Sato, Sandra; Pedrazzi, Vinícius

2013-01-01

Context: The absence of a protocol for the treatment of halitosis has led us to compare mouthrinses with mechanical oral hygiene procedures for treating morning breath by employing a hand-held sulfide monitor. Aims: To compare the efficacy of five modalities of treatment for controlling morning halitosis in subjects with no dental or periodontal disease. Settings and Design: This is a five-period, randomized, crossover clinical trial. Materials and Methods: Twenty volunteers were randomly assigned to the trial. Testing involved the use of a conventional tongue scraper, a tongue scraper joined to the back of a toothbrush's head, two mouthrinses (0.05% cetylpyridinium chloride and 0.12% chlorhexidine digluconate) and a soft-bristled toothbrush and fluoride toothpaste for practicing oral hygiene. Statistical Analysis Used: Data analysis was performed using SPSS version 17 for Windows and NCSS 2007 software (P < 0.05). The products and the periods were compared with each other using the Friedman's test. When significant differences (P < 0.05) were determined, the products and periods were compared in pairs by using the Wilcoxon's test and by adjusting the original significance level (0.05) for multiple comparisons by using the Bonferroni's method. Results: The toothbrush's tongue scraper was able to significantly reduce bad breath for up to 2 h. Chlorhexidine reduced bad breath only at the end of the second hour, an effect that lasted for 3 h. Conclusions: Mechanical tongue cleaning was able to immediately reduce bad breath for a short period, whereas chlorhexidine and mechanical oral hygiene reduced bad breath for longer periods, achieving the best results against morning breath. PMID:24554886

Effect of sodium hypochlorite irrigation with or without surfactants on the bond strength of an epoxy-based sealer to dentin.

PubMed

Guneser, Mehmet Burak; Arslan, Dilara; Dincer, Asiye Nur; Er, Gamze

2017-05-01

This study evaluated the effect of sodium hypochlorite (NaOCl) irrigation with or without surfactants on the bond strength of an epoxy-based sealer to the root canal dentin. Eighty decoronated single-rooted human mandibular premolars were instrumented using the rotary system. The roots were subsequently rinsed with 5 ml 17 % EDTA for 1 min and then randomly divided into 3 test groups (n = 20) and 1 control group (n = 20) according to the type of irrigation with experimental 5 % NaOCl (Wizard, RehberKimya, Istanbul, Turkey) solutions: Group 1: NaOCl-0.1 % benzalkonium chloride; Group 2: NaOCl-0.1 % Tween 80; Group 3: NaOCl-0.1 % Triton X-100; control group: NaOCl without any surfactants. Five samples from each group were prepared for scanning electron microscopy to examine the surface of root canal dentin. The 15 samples remaining in each group were obturated with gutta-percha and AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany) using the cold lateral compaction technique. A push-out test was used to measure the bond strength between the sealer and root canal dentin. Data were analyzed using two-way analysis of variance and Tukey's post hoc tests (P = 0.05). The NaOCl-0.1 % Triton X-100 group demonstrated the highest mean bond-strength values in all root thirds among the groups (P < 0.05). However, the bond strength of the sealer in the NaOCl-0.1 % benzalkonium chloride and NaOCl-0.1 % Tween 80 groups did not differ from that in the control group (P > 0.05). Additionally, the bond-strength values decreased in the corono-apical direction for all groups (P < 0.05). NaOCl solution with Triton X-100 can provide higher bond strength of the epoxy resin-based sealer to root dentin compared to NaOCl solution wiithout any surfactant. The bond strength of sealer to dentin can be improved by the addition of the surfactants to NaOCl solution.

Reduction of cytotoxicity of benzalkonium chloride and octenidine by Brilliant Blue G.

PubMed

Bartok, Melinda; Tandon, Rashmi; Alfaro-Espinoza, Gabriela; Ullrich, Matthias S; Gabel, Detlef

2015-01-01

The irritative effects of preservatives found in ophthalmologic solution, or of antiseptics used for skin disinfection is a consistent problem for the patients. The reduction of the toxic effects of these compounds is desired. Brilliant Blue G (BBG) has shown to meet the expected effect in presence of benzalkonium chloride (BAK), a well known preservative in ophthalmic solutions, and octenidine dihydrochloride (Oct), used as antiseptic in skin and wound disinfection. BBG shows a significant protective effect on human corneal epithelial (HCE) cells against BAK and Oct toxicity, increasing the cell survival up to 51 % at the highest BAK or Oct concentration tested, which is 0.01 %, both at 30 min incubation. Although BBG is described as a P2x7 receptor antagonist, other selective P2x7 receptor antagonists, OxATP (adenosine 5'-triphosphate-2',3'-dialdehyde) and DPPH (N'-(3,5-dichloropyridin-4-yl)-3-phenylpropanehydrazide), did not reduce the cytotoxicity of neither BAK nor Oct. Therefore we assume that the protective effect of BBG is not due to its action on the P2x7 receptor. Brilliant Blue R (BBR), a dye similar to BBG, was also tested for protective effect on BAK and Oct toxicity. In presence of BAK no significant protective effect was observed. Instead, with Oct a comparable protective effect was seen with that of BBG. To assure that the bacteriostatic effect is not affected by the combinations of BAK/BBG, Oct/BBG and Oct/BBR, bacterial growth inhibition was analyzed on different Gram-negative and Gram-positive bacteria. All combinations of BAK or Oct with BBG hinder growth of Gram-positive bacteria. The combinations of 0.001 % Oct and BBR above 0.025 % do not hinder the growth of B. subtilis. For Gram-negative bacteria, BBG and BBR reduce, but do not abolish, the antimicrobial effect of BAK nor of Oct. In conclusion, the addition of BBG at bacterial inhibitory concentrations is suggested in the ready-to-use ophthalmic preparations and antiseptic solutions.

Reduction of cytotoxicity of benzalkonium chloride and octenidine by Brilliant Blue G

PubMed Central

Bartok, Melinda; Tandon, Rashmi; Alfaro-Espinoza, Gabriela; Ullrich, Matthias S.; Gabel, Detlef

2015-01-01

The irritative effects of preservatives found in ophthalmologic solution, or of antiseptics used for skin disinfection is a consistent problem for the patients. The reduction of the toxic effects of these compounds is desired. Brilliant Blue G (BBG) has shown to meet the expected effect in presence of benzalkonium chloride (BAK), a well known preservative in ophthalmic solutions, and octenidine dihydrochloride (Oct), used as antiseptic in skin and wound disinfection. BBG shows a significant protective effect on human corneal epithelial (HCE) cells against BAK and Oct toxicity, increasing the cell survival up to 51 % at the highest BAK or Oct concentration tested, which is 0.01 %, both at 30 min incubation. Although BBG is described as a P2x7 receptor antagonist, other selective P2x7 receptor antagonists, OxATP (adenosine 5’-triphosphate-2’,3’-dialdehyde) and DPPH (N’-(3,5-dichloropyridin-4-yl)-3-phenylpropanehydrazide), did not reduce the cytotoxicity of neither BAK nor Oct. Therefore we assume that the protective effect of BBG is not due to its action on the P2x7 receptor. Brilliant Blue R (BBR), a dye similar to BBG, was also tested for protective effect on BAK and Oct toxicity. In presence of BAK no significant protective effect was observed. Instead, with Oct a comparable protective effect was seen with that of BBG. To assure that the bacteriostatic effect is not affected by the combinations of BAK/BBG, Oct/BBG and Oct/BBR, bacterial growth inhibition was analyzed on different Gram-negative and Gram-positive bacteria. All combinations of BAK or Oct with BBG hinder growth of Gram-positive bacteria. The combinations of 0.001 % Oct and BBR above 0.025 % do not hinder the growth of B. subtilis. For Gram-negative bacteria, BBG and BBR reduce, but do not abolish, the antimicrobial effect of BAK nor of Oct. In conclusion, the addition of BBG at bacterial inhibitory concentrations is suggested in the ready-to-use ophthalmic preparations and antiseptic solutions. PMID:26417355

Use of porcine vaginal tissue ex-vivo to model environmental effects on vaginal mucosa to toxic shock syndrome toxin-1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Catherine C.; Baccam, Mekhine; Mantz, Mary J.

Menstrual toxic shock syndrome (mTSS) is a rare, recognizable, and treatable disease that has been associated with tampon use epidemiologically. It involves a confluence of microbial risk factors (Staphylococcus aureus strains that produce the superantigen—TSST-1), as well as environmental characteristics of the vaginal ecosystem during menstruation and host susceptibility factors. This paper describes a series of experiments using the well-characterized model of porcine vaginal mucosa ex-vivo to assess the effect of these factors associated with tampon use on the permeability of the mucosa. The flux of radiolabeled TSST-1 and tritiated water ({sup 3}H{sub 2}O) through porcine vaginal mucosa was determinedmore » at various temperatures, after mechanical disruption of the epithelial surface by tape stripping, after treatment with surfactants or other compounds, and in the presence of microbial virulence factors. Elevated temperatures (42, 47 and 52 °C) did not significantly increase flux of {sup 3}H{sub 2}O. Stripping of the epithelial layers significantly increased the flux of labeled toxin in a dose-dependent manner. Addition of benzalkonium chloride (0.1 and 0.5%) and glycerol (4%) significantly increased the flux of {sup 3}H{sub 2}O but sodium lauryl sulfate at any concentration tested did not. The flux of the labeled toxin was significantly increased in the presence of benzalkonium chloride but not Pluronic® L92 and Tween 20 and significantly increased with addition of α-hemolysin but not endotoxin. These results show that the permeability of porcine vagina ex-vivo to labeled toxin or water can be used to evaluate changes to the vaginal environment and modifications in tampon materials, and thus aid in risk assessment. - Highlights: • Model assessed local effects of tampon use on vaginal mucosa. • Risks were evaluated using two tracers to assess permeability in an ex vivo model. • Mechanical damage to the epithelial surface increased tracer penetration. • Surfactants increased penetration of tracers across vaginal mucosa. • Alpha-hemolysin increased the penetration of bacterial toxin across vaginal mucosa.« less

Research on the stability of a rabbit dry eye model induced by topical application of the preservative benzalkonium chloride.

PubMed

Li, Chaoyang; Song, Yiyue; Luan, Shaohong; Wan, Pengxia; Li, Naiyang; Tang, Jing; Han, Yu; Xiong, Cuiju; Wang, Zhichong

2012-01-01

Dry eye is a common disease worldwide, and animal models are critical for the study of it. At present, there is no research about the stability of the extant animal models, which may have negative implications for previous dry eye studies. In this study, we observed the stability of a rabbit dry eye model induced by the topical benzalkonium chloride (BAC) and determined the valid time of this model. Eighty white rabbits were randomly divided into four groups. One eye from each rabbit was randomly chosen to receive topical 0.1% BAC twice daily for 2 weeks (Group BAC-W2), 3 weeks (Group BAC-W3), 4 weeks (Group BAC-W4), or 5 weeks (Group BAC-W5). Fluorescein staining, Schirmer's tests, and conjunctival impression cytology were performed before BAC treatment (normal) and on days 0, 7, 14 and 21 after BAC removal. The eyeballs were collected at these time points for immunofluorescence staining, hematoxylin and eosin (HE) staining, and electron microscopy. After removing BAC, the signs of dry eye in Group BAC-W2 lasted one week. Compared with normal, there were still significant differences in the results of Schirmer's tests and fluorescein staining in Groups BAC-W3 and BAC-W4 on day 7 (P<0.05) and in Group BAC-W5 on day 14 (P<0.05). Decreases in goblet cell density remained stable in the three experimental groups at all time points (P<0.001). Decreased levels of mucin-5 subtype AC (MUC5AC), along with histopathological and ultrastructural disorders of the cornea and conjunctiva could be observed in Group BAC-W4 and particularly in Group BAC-W5 until day 21. A stable rabbit dry eye model was induced by topical 0.1% BAC for 5 weeks, and after BAC removal, the signs of dry eye were sustained for 2 weeks (for the mixed type of dry eye) or for at least 3 weeks (for mucin-deficient dry eye).

Formulation and in vitro evaluation of cysteamine hydrochloride viscous solutions for the treatment of corneal cystinosis.

PubMed

Bozdağ, Sibel; Gümüş, Koray; Gümüş, Ozlem; Unlü, Nurşen

2008-09-01

In the present study, viscous solutions of cysteamine hydrochloride (CH) were prepared by using 0.5%, 1.0%, 1.5% or 3.0% of hydroxypropylmethylcellulose (HPMC) and were evaluated for their in-vitro characteristics and stability. Osmolalities, pH and viscosity of the formulations were determined. The influence of benzalkonium chloride and autoclave sterilization on solution characteristics was also investigated. For stability assessment, the viscous solutions were stored at +4 and +25 degrees C over 12 months. In-vitro characteristics and CH contents of the stored solutions were monitored. Irritation tests for the formulations were evaluated on rabbit eyes. Dialysis sac technique was used to perform in vitro release study of the solutions containing 1.0% and 1.5% HPMC. All of the viscous solutions tested showed non-newtonian (dilatant) flow behavior. Osmolality values were ranked between 351.2+/-6.2 and 355.1+/-7.9 mOsm kg(-1), and pH values were between 3.97+/-0.1 and 3.98+/-0.2 for all the solutions. Furthermore, no significant changes in dilatant behavior, osmolality or pH values of the pure HPMC solutions were observed. After addition of the excipients or CH-excipients, increased viscosity values were noted in these formulations. Neither benzalkonium chloride nor autoclave sterilization had any influence on viscosity, pH or osmolality values of the solution containing 1.5% HPMC. Stability studies showed that a faster decrease in the concentration of CH was observed in the formulations stored at 25 degrees C compared to those kept at 4 degrees C; no changes were determined in osmolality values of the solutions at all storage conditions. Increased pH and decreased viscosity values were noted in HPMC solutions containing CH and excipients, while no changes in these values were observed for pure HPMC solutions kept at 4 and 25 degrees C. In vitro release tests revealed that 81.2% and 85.3% of CH were released from the viscous solutions containing 1.5% and 1% HPMC, respectively, in 8h. No irritation was observed when the viscous solutions were tested on rabbit and human eyes.

Research on the Stability of a Rabbit Dry Eye Model Induced by Topical Application of the Preservative Benzalkonium Chloride

PubMed Central

Luan, Shaohong; Wan, Pengxia; Li, Naiyang; Tang, Jing; Han, Yu; Xiong, Cuiju; Wang, Zhichong

2012-01-01

Background Dry eye is a common disease worldwide, and animal models are critical for the study of it. At present, there is no research about the stability of the extant animal models, which may have negative implications for previous dry eye studies. In this study, we observed the stability of a rabbit dry eye model induced by the topical benzalkonium chloride (BAC) and determined the valid time of this model. Methods and Findings Eighty white rabbits were randomly divided into four groups. One eye from each rabbit was randomly chosen to receive topical 0.1% BAC twice daily for 2 weeks (Group BAC-W2), 3 weeks (Group BAC-W3), 4 weeks (Group BAC-W4), or 5 weeks (Group BAC-W5). Fluorescein staining, Schirmer's tests, and conjunctival impression cytology were performed before BAC treatment (normal) and on days 0, 7, 14 and 21 after BAC removal. The eyeballs were collected at these time points for immunofluorescence staining, hematoxylin and eosin (HE) staining, and electron microscopy. After removing BAC, the signs of dry eye in Group BAC-W2 lasted one week. Compared with normal, there were still significant differences in the results of Schirmer's tests and fluorescein staining in Groups BAC-W3 and BAC-W4 on day 7 (P<0.05) and in Group BAC-W5 on day 14 (P<0.05). Decreases in goblet cell density remained stable in the three experimental groups at all time points (P<0.001). Decreased levels of mucin-5 subtype AC (MUC5AC), along with histopathological and ultrastructural disorders of the cornea and conjunctiva could be observed in Group BAC-W4 and particularly in Group BAC-W5 until day 21. Conclusions A stable rabbit dry eye model was induced by topical 0.1% BAC for 5 weeks, and after BAC removal, the signs of dry eye were sustained for 2 weeks (for the mixed type of dry eye) or for at least 3 weeks (for mucin-deficient dry eye). PMID:22438984

Evaluation of the cytotoxic effects of ophthalmic solutions containing benzalkonium chloride on corneal epithelium using an organotypic 3-D model

PubMed Central

Khoh-Reiter, Su; Jessen, Bart A

2009-01-01

Background Benzalkonium chloride (BAC) is a common preservative used in ophthalmic solutions. The aim of this study was to compare the cytotoxic effects of BAC-containing ophthalmic solutions with a BAC-free ophthalmic solution using an organotypic 3-dimensional (3-D) corneal epithelial model and to determine the effects of latanoprost ophthalmic solution and its BAC-containing vehicle on corneal thickness in a monkey model. Methods The cytotoxicity of commercially available BAC-containing ophthalmic formulations of latanoprost (0.02% BAC) and olopatadine (0.01% BAC) was compared to that of BAC-free travoprost and saline in a corneal organotypic 3-D model using incubation times of 10 and 25 minutes. To compare the extent of differentiation of 3-D corneal cultures to monolayer transformed human corneal epithelial (HCE-T) cell cultures, expression levels (mRNA and protein) of the corneal markers epidermal growth factor receptor, transglutaminase 1 and involucrin were quantified. Finally, latanoprost ophthalmic solution or its vehicle was administered at suprapharmacologic doses (two 30 μL drops twice daily in 1 eye for 1 year) in monkey eyes, and corneal pachymetry was performed at baseline and at weeks 4, 13, 26 and 52. Results In the 3-D corneal epithelial culture assays, there were no significant differences in cytotoxicity between the BAC-containing latanoprost and olopatadine ophthalmic solutions and BAC-free travoprost ophthalmic solution at either the 10- or 25-minute time points. The 3-D cultures expressed higher levels of corneal epithelial markers than the HCE-T monolayers, indicating a greater degree of differentiation. There were no significant differences between the corneal thickness of monkey eyes treated with latanoprost ophthalmic solution or its vehicle (both containing 0.02% BAC) and untreated eyes. Conclusion The lack of cytotoxicity demonstrated in 3-D corneal cultures and in monkey studies suggests that the levels of BAC contained in ophthalmic solutions are not likely to cause significant direct toxicity to epithelium of otherwise normal corneas. PMID:19638217

Effect of benzalkonium chloride-free latanoprost ophthalmic solution on ocular surface in patients with glaucoma.

PubMed

Walimbe, Tejaswini; Chelerkar, Vidya; Bhagat, Purvi; Joshi, Abhijeet; Raut, Atul

2016-01-01

Benzalkonium chloride (BAK), included as a preservative in many topical treatments for glaucoma, induces significant toxicity and alters tear breakup time (TBUT). BAK-containing latanoprost, an ester prodrug of prostaglandin F2α, can cause ocular adverse events (AEs) associated with BAK. The purpose of this study was to evaluate the efficacy and safety of BAK-free latanoprost. A prospective, open-label, single-arm, multicenter, 8-week study in patients with primary open-angle glaucoma or ocular hypertension taking BAK-containing latanoprost for ≥12 months was performed. Patients were switched to BAK-free latanoprost ophthalmic solution 0.005% administered once daily, and eyes were assessed after 28 and 56 days. Primary efficacy and safety variables were TBUT and treatment-emergent AEs, respectively. At day 56, 40 eyes were evaluable. Mean TBUT increased significantly from baseline (3.67±1.60 seconds) to 5.03±2.64 and 6.06±3.39 seconds after 28 and 56 days of treatment with BAK-free latanoprost (P<0.0001). Ocular Surface Disease Index(©) (OSDI(©)) score also decreased significantly to 12.06±13.40 and 7.06±10.75 at 28 and 56 days, respectively, versus baseline (18.09±18.61, P<0.0001). In addition, inferior corneal staining score decreased significantly to 0.53 from baseline (0.85, P=0.0033). A reduction in conjunctival hyperemia and intraocular pressure was observed at both time points. No treatment-related serious AEs were evident and 12 (26.08%) treatment-emergent AEs occurred in seven patients, with eye pain and irritation being the most frequent. No clinically significant changes in vital signs or slit lamp examinations were observed. Results indicate that switching from BAK-containing latanoprost to BAK-free latanoprost resulted in significant improvements in TBUT, OSDI(©) score, and inferior corneal staining score, and measurable reductions in conjunctival hyperemia score. Furthermore, BAK-free latanoprost was well tolerated with only mild-to-moderate and self-limiting AEs. BAK-free latanoprost appears to be effective in protecting ocular surface integrity in glaucoma patients but further studies are needed to confirm this beneficial effect.

Effects of benzalkonium chloride on growth and survival of Chang conjunctival cells.

PubMed

De Saint Jean, M; Brignole, F; Bringuier, A F; Bauchet, A; Feldmann, G; Baudouin, C

1999-03-01

The aim of this study was to investigate the action of benzalkonium chloride (BAC), used as a preservative in most ophthalmic topical solutions, on epithelial conjunctival cells in vitro. A continuous human conjunctival cell line (Wong-Kilbourne derivative of Chang conjunctiva) was exposed to BAC solutions at various concentrations (0.1%-0.0001%) during a period of 10 minutes. Cells were examined before treatment and 3, 24, 48, and 72 hours later, after reexposure to normal cell culture conditions. Cell number and viability were assessed with crystal violet and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide colorimetric assays. The expression of the apoptotic marker Apo 2.7, nuclear antigen p53, membrane proteins Fas and Fas ligand, and DNA content was studied by flow cytometry. Morphologic aspects of cell nuclei were analyzed on slides with a nucleic acid-specific dye, 4',6'-diamidino-2-phenylindole dihydrochloride. Cytoskeleton was labeled with a monoclonal anti-pancytokeratin antibody. In addition, apoptosis was measured by DNA electrophoresis assays in agarose gel. Cell exposure to 0.1% and 0.05% BAC induced cell lysis immediately after treatment. All cells (100%) treated with 0.01% BAC died in a delayed manner within 24 hours, with most of the characteristics of apoptosis (chromatin condensation and DNA fragmentation, reduction in cell volume, expression of the apoptotic marker Apo 2.7, and apoptotic changes in DNA content). Aliquots of 0.005%, 0.001%, 0.0005%, and 0.0001% BAC induced growth arrest and apoptotic cell death in a dose-dependent manner between 24 and 72 hours after treatment. The expressions of Fas and p53 did not vary after BAC treatment. Fas ligand was always negative. These results suggest that BAC induces cell growth arrest and death at a concentration as low as 0.0001%. The mode of BAC-induced cell death is dose-dependent. Cells die by necrosis after BAC treatment at high concentrations and by apoptosis if low concentrations of BAC are applied. This new aspect of in vitro toxicity of BAC could in part explain some ocular surface disorders observed in patients undergoing long-term topical treatments with preservative-containing drugs.

Corrosion kinetics and topography analysis of Ti-6Al-4V alloy subjected to different mouthwash solutions.

PubMed

Faverani, Leonardo Perez; Barao, Valentim Adelino Ricardo; Pires, Maria Flávia Araújo; Yuan, Judy Chia-Chun; Sukotjo, Cortino; Mathew, Mathew T; Assunção, Wirley Gonçalves

2014-10-01

This study evaluated the corrosion kinetics and surface topography of Ti-6Al-4V alloy exposed to mouthwash solutions (0.12% chlorhexidine digluconate, 0.053% cetylpyridinium chloride and 3% hydrogen peroxide) compared to artificial saliva (pH6.5) (control). Twenty Ti-6Al-4V alloy disks were used and divided into 4 groups (n=5). For the electrochemical assay, standard tests as open circuit potential and electrochemical impedance spectroscopy (EIS) were applied at baseline, 7 and 14days after immersion in the solutions. Scanning electron microscopy, atomic force microscopy and profilometry (average roughness - Ra) were used for surface characterization. Total weight loss of disks was calculated. Data were analyzed by ANOVA and Bonferroni's test (α=0.05). Hydrogen peroxide generated the lowest polarization resistance (Rp) values for all periods (P<0.05). For the capacitance (Cdl), similar results were observed among groups at baseline (P=0.098). For the 7 and 14-day periods, hydrogen peroxide promoted the highest Cdl values (P<0.0001). Hydrogen peroxide promoted expressive superficial changes and greater Ra values than the others (P<0.0001). It could be concluded that solutions containing cetylpyridinium chloride and chlorhexidine digluconate might be the mouthwashes of choice during the post-operatory period of dental implants. However, hydrogen peroxide is counter-indicated in these situations. Further studies evaluating the dynamics of these solutions (tribocorrosion) and immersing the disks in daily cycles (two or three times a day) to mimic a clinical situation closest to the application of mouthwashes in the oral cavity are warranted to prove our results. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of new chlorhexidine- and cetylpyridinium chloride-based mouthrinse formulations adjunctive to scaling and root planing: pilot study.

PubMed

García-Gargallo, M; Zurlohe, M; Montero, E; Alonso, B; Serrano, J; Sanz, M; Herrera, D

2017-11-01

To compare the effect of two newly formulated chlorhexidine (CHX) and cetylpyridinium chloride (CPC) mouthrinses after scaling and root planing (SRP) in terms of clinical, microbiological, patient-based variables and adverse events, with a positive control with the same active components, already marketed and tested. A pilot, randomized clinical trial, double-blind, parallel design with 1-month follow-up was conducted. Chronic periodontitis patients requiring non-surgical periodontal therapy were enrolled and randomly assigned to: (i) SRP and test-1 (new reformulation: 0.12% CHX and 0.05% CPC); (ii) SRP and test-2 (new formulation: 0.03% CHX and 0.05% CPC); or (iii) SRP and positive control (commercial product: 0.12% CHX and 0.05% CPC). All variables were evaluated at baseline and 1 month after SRP. Quantitative variables were compared by means of anova or Kruskal-Wallis test and qualitative variables by chi-square or McNemar tests. Thirty patients (10 per group) were included. After 1 month, there were significant differences among groups in plaque levels (P = 0.016) as test-1 showed less sites with plaque than test-2 (31.15% [standard error-SE 2.21%] versus 49.39% [SE 4.60%), respectively). No significant differences were found for global patient perception of the product or in adverse effects. Test groups showed better results in levels and proportions (P = 0.022) of Capnocytophaga spp. Within the limitations of this pilot study, it can be concluded that the newly formulated 0.12% CHX and 0.05% CPC mouthrinse showed larger plaque level reductions, without showing more adverse effects, when compared to the other two mouthrinses, after SRP. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Component Release and Mechanical Properties of Endodontic Sealers following Incorporation of Antimicrobial Agents.

PubMed

Gjorgievska, Elizabeta S; Nicholson, John W; Coleman, Nichola J; Booth, Samantha; Dimkov, Aleksandar; Hurt, Andrew

2017-01-01

Root canal sealers with antimicrobial activity are highly beneficial; therefore, their antimicrobial properties could be improved by incorporation of antimicrobial agents. In the present study, the release of the quaternary ammonium compounds from endodontic sealers admixed with either benzalkonium chloride (BC) or cetylpyridinium chloride (CPC) at loadings of 2% wt was monitored. The effect of these additives on the compressive strengths and their release from the sealers was determined after 1 and 4 weeks. All of the materials studied were found to be capable of releasing antimicrobial additive in useful quantities. The release of CPC occurred to a statistically significant greater extent than BC for all materials. The addition of both BC and CPC generally decreased the compressive strength of all the endodontic sealers, with the exception of CPC in AH Plus, where the compressive strength was significantly increased. This suggests that, for these endodontic sealers, the antimicrobial additives alter the setting chemistry. AH Plus is an epoxy-based material cured with an amine, and in this case the increase in compressive strength with CPC is attributed to an enhanced cure reaction with this system. In all other cases, the additive inhibited the cure reaction to a greater or lesser extent.

Determination of selected quaternary ammonium compounds by liquid chromatography with mass spectrometry. Part II. Application to sediment and sludge samples in Austria.

PubMed

Martínez-Carballo, Elena; González-Barreiro, Carmen; Sitka, Andrea; Kreuzinger, Norbert; Scharf, Sigrid; Gans, Oliver

2007-03-01

Soxhlet extraction and high-performance liquid chromatography (HPLC) coupled to tandem mass spectrometry detection (MS/MS) was used for the determination of selected quaternary ammonium compounds (QACs) in solid samples. The method was applied for the determination of alkyl benzyl, dialkyl and trialkyl quaternary ammonium compounds in sediment and sludge samples in Austria. The overall method quantification limits range from 0.6 to 3 microg/kg for sediments and from 2 to 5 microg/kg for sewage sludges. Mean recoveries between 67% and 95% are achieved. In general sediments were especially contaminated by C12 chain benzalkonium chloride (BAC-C12) as well as by the long C-chain dialkyldimethylammonium chloride (DDAC-C18) with a maximum concentration of 3.6 mg/kg and 2.1mg/kg, respectively. Maxima of 27 mg/kg for DDAC-C10, 25 mg/kg for BAC-C12 and 23 mg/kg for BAC-C14 were determined for sludge samples. The sums of the 12 selected target compounds range from 22 mg/kg to 103 mg/kg in the sludge samples.

Vaginal microbicides: detecting toxicities in vivo that paradoxically increase pathogen transmission

PubMed Central

Cone, Richard A; Hoen, Timothy; Wong, XiXi; Abusuwwa, Raed; Anderson, Deborah J; Moench, Thomas R

2006-01-01

Background Microbicides must protect against STD pathogens without causing unacceptable toxic effects. Microbicides based on nonoxynol-9 (N9) and other detergents disrupt sperm, HSV and HIV membranes, and these agents are effective contraceptives. But paradoxically N9 fails to protect women against HIV and other STD pathogens, most likely because it causes toxic effects that increase susceptibility. The mouse HSV-2 vaginal transmission model reported here: (a) Directly tests for toxic effects that increase susceptibility to HSV-2, (b) Determines in vivo whether a microbicide can protect against HSV-2 transmission without causing toxicities that increase susceptibility, and (c) Identifies those toxic effects that best correlate with the increased HSV susceptibility. Methods Susceptibility was evaluated in progestin-treated mice by delivering a low-dose viral inoculum (0.1 ID50) at various times after delivering the candidate microbicide to detect whether the candidate increased the fraction of mice infected. Ten agents were tested – five detergents: nonionic (N9), cationic (benzalkonium chloride, BZK), anionic (sodium dodecylsulfate, SDS), the pair of detergents in C31G (C14AO and C16B); one surface active agent (chlorhexidine); two non-detergents (BufferGel®, and sulfonated polystyrene, SPS); and HEC placebo gel (hydroxyethylcellulose). Toxic effects were evaluated by histology, uptake of a 'dead cell' dye, colposcopy, enumeration of vaginal macrophages, and measurement of inflammatory cytokines. Results A single dose of N9 protected against HSV-2 for a few minutes but then rapidly increased susceptibility, which reached maximum at 12 hours. When applied at the minimal concentration needed for brief partial protection, all five detergents caused a subsequent increase in susceptibility at 12 hours of ~20–30-fold. Surprisingly, colposcopy failed to detect visible signs of the N9 toxic effect that increased susceptibility at 12 hours. Toxic effects that occurred contemporaneously with increased susceptibility were rapid exfoliation and re-growth of epithelial cell layers, entry of macrophages into the vaginal lumen, and release of one or more inflammatory cytokines (Il-1β, KC, MIP 1α, RANTES). The non-detergent microbicides and HEC placebo caused no significant increase in susceptibility or toxic effects. Conclusion This mouse HSV-2 model provides a sensitive method to detect microbicide-induced toxicities that increase susceptibility to infection. In this model, there was no concentration at which detergents provided protection without significantly increasing susceptibility. PMID:16740164

Electrophysiologic and morphologic effects of ophthalmic preparations on rabbit cornea epithelium.

PubMed

Burstein, N L; Klyce, S D

1977-10-01

The effects of several components of ophthalmic preparations on isolated rabbit cornea were studied by continuous electrophysiologic monitoring followed by fixation for scanning electron microscopy (SEM). Benzalkonium chloride (0.001 percent), thimerosal (0.0004 percent), and amphotericin B (0.0025 percent) all briefly increased ion transport, then greatly decreased epithelial resistance. Severe disruption of surface cell layers occurred simultaneously with resistance decrease. Silver nitrate (0.00017 percent) stimulated transport with less accompanying morphologic damage. Tetracaine (0.05 percent) disrupted epithelial function and caused exfoliation of several cell layers. Chlorobutanol (0.1 percent) produced a nearly complete loss of the squamous cell layer. Chloramphenicol, epinephrine, and pilocarpine produced minor changes in structure and electrophysiology at full clinical concentration. It was concluded that low concentrations of preservatives in ophthalmic preparations disrupt the barrier and transport properties of the corneal epithelium.

Synthesis and Antibacterial Activity of Quaternary Ammonium 4-Deoxypyridoxine Derivatives

PubMed Central

Shtyrlin, Nikita V.; Sapozhnikov, Sergey V.; Galiullina, Albina S.; Kayumov, Airat R.; Bondar, Oksana V.; Mirchink, Elena P.; Isakova, Elena B.; Firsov, Alexander A.; Balakin, Konstantin V.

2016-01-01

A series of novel quaternary ammonium 4-deoxypyridoxine derivatives was synthesized. Two compounds demonstrated excellent activity against a panel of Gram-positive methicillin-resistant S. aureus strains with MICs in the range of 0.5–2 μg/mL, exceeding the activity of miramistin. At the same time, both compounds were inactive against the Gram-negative E. coli and P. aeruginosa strains. Cytotoxicity studies on human skin fibroblasts and embryonic kidney cells demonstrated that the active compounds possessed similar toxicity with benzalkonium chloride but were slightly more toxic than miramistin. SOS-chromotest in S. typhimurium showed the lack of DNA-damage activity of both compounds; meanwhile, one compound showed some mutagenic potential in the Ames test. The obtained results make the described chemotype a promising starting point for the development of new antibacterial therapies. PMID:27800491

Chlorhexidine salt-loaded polyurethane orthodontic chains: in vitro release and antibacterial activity studies.

PubMed

Padois, Karine; Bertholle, Valérie; Pirot, Fabrice; Hyunh, Truc Thanh Ngoc; Rossi, Alessandra; Colombo, Paolo; Falson, Françoise; Sonvico, Fabio

2012-12-01

The widespread use of indwelling medical devices has enormously increased the interest in materials incorporating antibiotics and antimicrobial agents as a means to prevent dangerous device-related infections. Recently, chlorhexidine-loaded polyurethane has been proposed as a material suitable for the production of devices which are able to resist microbial contamination. The aim of the present study was to characterize the in vitro release of chlorhexidine from new polymeric orthodontic chains realized with polyurethane loaded with two different chlorhexidine salts: chlorhexidine diacetate or chlorhexidine digluconate. The orthodontic chains constituted of three layers: a middle polyurethane layer loaded with chlorhexidine salt inserted between two layers of unloaded polymer. In vitro release of chlorhexidine diacetate and digluconate from orthodontic chains loaded with 10% or 20% (w/w) chlorhexidine salt was sustained for 42 days and followed Fickian diffusion. The drug diffusion through the polyurethane was found to be dependent not only on chlorhexidine loading, but also on the type of chlorhexidine salt. The antibacterial activity of 0.2% (w/w) chlorhexidine diacetate-loaded orthodontic chain was successfully tested towards clinically isolated biofilm forming ica-positive Staphylococcus epidermidis via agar diffusion test. In conclusion, the chlorhexidine salt-loaded chains could provide an innovative approach in the prevention of oral infections related to the use of orthodontic devices.

Prevention of zebra mussel infestation and dispersal during aquaculture operations

USGS Publications Warehouse

Waller, D.L.; Fisher, S.W.; Dabrowska, H.

1996-01-01

The zebra mussel Dreissena polymorpha, an exotic invasive species, poses a major threat to North American fish management programs and the aquaculture industry. Fish hatcheries may become infected with zebra mussels from a variety of sources, including the water supply, fish shipments, boats, and equipment. The hatcheries could then serve as agents for the overland dispersal of zebra mussels into stocked waters and to other fish hatcheries. We evaluated the effectiveness and safety of aquaculture chemicals for use in controlling zebra mussels in fish hatcheries and preventing dispersal of veligers during fish transport. Chemicals were evaluated for use in fish transport and as disinfectants for ponds and equipment. Standardized static toxicity tests were conducted with representative species of warmwater, coolwater, and coldwater fishes and with larval (3-d-old veligers), early juvenile (settling larvae), and adult zebra mussels. Chemical concentrations and exposure durations were based on recommended treatment levels for fish, eggs, and ponds. Recommended treatment levels were also exceeded, if necessary, to establish lethal levels for zebra mussels of different developmental stages. Our results indicate that some chemicals currently in use in hatcheries may be effective for controlling zebra mussels in various operations. Chloride salts were the safest and most effective therapeutants tested for use in fish transport. The toxicity of chloride salts to fish varied among species and with temperature; only one treatment regime (sodium chloride at 10,000 mg/L) was safe to all fish species that we tested, but it was only effective on veliger and settler stages of the zebra mussel. Effective disinfectants were benzalkonium chloride for use on equipment and rotenone for use in ponds after fish are harvested. The regulatory status of the identified chemicals is discussed as well as several nonchemical control alternatives.

Chlorhexidine Induces VanA-Type Vancomycin Resistance Genes in Enterococci

PubMed Central

Bhardwaj, Pooja; Ziegler, Elizabeth

2016-01-01

Chlorhexidine is a bisbiguanide antiseptic used for infection control. Vancomycin-resistant E. faecium (VREfm) is among the leading causes of hospital-acquired infections. VREfm may be exposed to chlorhexidine at supra- and subinhibitory concentrations as a result of chlorhexidine bathing and chlorhexidine-impregnated central venous catheter use. We used RNA sequencing to investigate how VREfm responds to chlorhexidine gluconate exposure. Among the 35 genes upregulated ≥10-fold after 15 min of exposure to the MIC of chlorhexidine gluconate were those encoding VanA-type vancomycin resistance (vanHAX) and those associated with reduced daptomycin susceptibility (liaXYZ). We confirmed that vanA upregulation was not strain or species specific by querying other VanA-type VRE. VanB-type genes were not induced. The vanH promoter was found to be responsive to subinhibitory chlorhexidine gluconate in VREfm, as was production of the VanX protein. Using vanH reporter experiments with Bacillus subtilis and deletion analysis in VREfm, we found that this phenomenon is VanR dependent. Deletion of vanR did not result in increased chlorhexidine susceptibility, demonstrating that vanHAX induction is not protective against chlorhexidine. As expected, VanA-type VRE is more susceptible to ceftriaxone in the presence of sub-MIC chlorhexidine. Unexpectedly, VREfm is also more susceptible to vancomycin in the presence of subinhibitory chlorhexidine, suggesting that chlorhexidine-induced gene expression changes lead to additional alterations in cell wall synthesis. We conclude that chlorhexidine induces expression of VanA-type vancomycin resistance genes and genes associated with daptomycin nonsusceptibility. Overall, our results indicate that the impacts of subinhibitory chlorhexidine exposure on hospital-associated pathogens should be further investigated in laboratory studies. PMID:26810654

Implant decontamination with 2% chlorhexidine during surgical peri-implantitis treatment: a randomized, double-blind, controlled trial.

PubMed

de Waal, Y C M; Raghoebar, G M; Meijer, H J A; Winkel, E G; van Winkelhoff, A J

2015-09-01

The objective of this randomized, double-blind, controlled trial was to evaluate the clinical, radiographic, and microbiological effects of implant surface decontamination with a 2% chlorhexidine (CHX) solution in comparison with a 0.12% chlorhexidine + 0.05% cetylpyridinium chloride (CPC) solution during resective surgical peri-implantitis treatment. Forty-four patients (108 implants) with peri-implantitis were treated with resective surgical treatment consisting of bone re-contouring, surface debridement and chemical decontamination, and apically repositioned flap. Patients were randomly allocated to decontamination with a 2% CHX solution (test group) or 0.12% CHX + 0.05% CPC (control group). Clinical and radiographic parameters were recorded before treatment (baseline), and at 3, 6, and 12 months after treatment. Microbiological parameters were recorded during surgery. Multilevel analysis showed no significant differences in bleeding, suppuration, probing pocket depth, and radiographic bone loss between control and test group over three follow-up measurements (3, 6, and 12 months) from baseline. Both decontamination procedures resulted in significant reductions in anaerobic bacterial counts on the implant surface, but no significant difference was noted between control and test group (mean log 3.37 ± 2.34 vs. 3.65 ± 2.87, P = 0.99). The use of a 2% CHX solution for implant surface decontamination during resective peri-implantitis therapy does not lead to improved clinical, radiographic, or microbiological results compared with a 0.12% CHX + 0.05% CPC solution. Overall, the additional use of CHX reduces anaerobic bacterial load on the implant surface better than mechanical debridement alone, but does not seem to enhance clinical treatment outcomes (ClinicalTrials.gov number NCT01852253). © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparative effect of a new mouthrinse containing chlorhexidine, triclosan and zinc on volatile sulphur compounds: a randomized, crossover, double-blind study.

PubMed

Mendes, L; Coimbra, J; Pereira, A L; Resende, M; Pinto, M G

2016-08-01

The aims of this study were to compare the volatile sulphur compounds (VSC)-reducing effect of two commercial mouthrinses using a morning bad breath model and to assess the role of mechanical plaque control (MPC) when performed previously to mouthrinse use. Eleven volunteers with good oral health were enrolled in a double-blind, randomized, six-step crossover design study with a 7-day washout period. Two commercial mouthrinses were tested using a saline solution (NaCl 0.9%) as a negative control: one mouthrinse contained 0.05% chlorhexidine, 0.05% cetylpyridinium chloride and 0.14% zinc lactate (CHX-CPC-Zn), while the other contained 0.05% chlorhexidine, 0.15% triclosan and 0.18% zinc pidolate (CHX-triclosan-Zn). A portable sulphide monitor (Halimeter(®) ) was used for VSC quantification. Measurements were made at baseline, and 1, 3 and 5 h after rinsing. Significant differences were detected by analysis of variance. No significant differences between groups were detected at baseline. We were unable to demonstrate a significant influence of mechanical plaque control on the reduction of VSC levels when performed before mouthrinse use (P = 0.631). Both mouthrinses effectively lowered VSC levels in all test intervals (P < 0.05). No statistically significant differences were found between mouthrinses in any of the test intervals (P = 0.629, 0.069 and 0.598 at 1, 3 and 5 h). This study demonstrated that CHX-CPC-Zn and CHX-triclosan-Zn have significant and similar effects in reducing VSC levels, which persist for at least 5 h. Such effects were independent of previous MPC, which failed to improve on the results of mouthrinse use alone. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Chlorhexidine in cosmetic products - a market survey.

PubMed

Opstrup, Morten S; Johansen, Jeanne D; Bossi, Rossana; Lundov, Michael D; Garvey, Lene H

2015-01-01

Chlorhexidine may cause type I and type IV allergy. Some chlorhexidine-allergic individuals have been exposed in the healthcare setting as patients or healthcare workers, but for others the source of sensitization is unknown. Chlorhexidine may be used as a preservative or an antimicrobial agent in cosmetic products at a concentration up to 0.3%, as set by the European Cosmetics Directive (now Regulations). To identify cosmetic product types containing chlorhexidine, and to measure the concentration of chlorhexidine in selected products. Between February 2013 and April 2013, we checked for chlorhexidine in cosmetic products in 14 supermarkets, one hairdressing salon and one beauty and retail store in Copenhagen, Denmark by reading the ingredient labels. The chlorhexidine concentration was measured in 10 selected products by high-performance liquid chromatography (HPLC) with an ultraviolet (UV) detector. Chlorhexidine was found in 80 of 2251 checked products (3.6%) in the following categories: hair products (57/760), creams (9/324), face washes (4/24), wet wipes (4/63), skin tonics (3/22), make-up removers (2/25), and mouth washes (1/17). Chlorhexidine concentrations were 0.01-0.15%. We found chlorhexidine in various cosmetic product types, predominantly aimed at females, and in hair products. The measured chlorhexidine concentrations were all within the permitted limit. The relevance for allergic sensitization should be further explored. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Urine Preservative

NASA Technical Reports Server (NTRS)

Smith, Scott M. (Inventor); Nillen, Jeannie (Inventor)

2001-01-01

Disclosed is CPG, a combination of a chlorhexidine salt (such as chlorhexidine digluconate, chlorhexidine diacetate, or chlorhexidine dichloride) and n-propyl gallate that can be used at ambient temperatures as a urine preservative.

The forgotten role of alcohol: a systematic review and meta-analysis of the clinical efficacy and perceived role of chlorhexidine in skin antisepsis.

PubMed

Maiwald, Matthias; Chan, Edwin S Y

2012-01-01

Skin antisepsis is a simple and effective measure to prevent infections. The efficacy of chlorhexidine is actively discussed in the literature on skin antisepsis. However, study outcomes due to chlorhexidine-alcohol combinations are often attributed to chlorhexidine alone. Thus, we sought to review the efficacy of chlorhexidine for skin antisepsis and the extent of a possible misinterpretation of evidence. We performed a systematic literature review of clinical trials and systematic reviews investigating chlorhexidine compounds for blood culture collection, vascular catheter insertion and surgical skin preparation. We searched PubMed, CINAHL, the Cochrane Library, the Agency for Healthcare Research and Quality website, several clinical trials registries and a manufacturer website. We extracted data on study design, antiseptic composition, and the following outcomes: blood culture contamination, catheter colonisation, catheter-related bloodstream infection and surgical site infection. We conducted meta-analyses of the clinical efficacy of chlorhexidine compounds and reviewed the appropriateness of the authors' attribution. In all three application areas and for all outcomes, we found good evidence favouring chlorhexidine-alcohol over aqueous competitors, but not over competitors combined with alcohols. For blood cultures and surgery, we found no evidence supporting chlorhexidine alone. For catheters, we found evidence in support of chlorhexidine alone for preventing catheter colonisation, but not for preventing bloodstream infection. A range of 29 to 43% of articles attributed outcomes solely to chlorhexidine when the combination with alcohol was in fact used. Articles with ambiguous attribution were common (8-35%). Unsubstantiated recommendations for chlorhexidine alone instead of chlorhexidine-alcohol were identified in several practice recommendations and evidence-based guidelines. Perceived efficacy of chlorhexidine is often in fact based on evidence for the efficacy of the chlorhexidine-alcohol combination. The role of alcohol has frequently been overlooked in evidence assessments. This has broader implications for knowledge translation as well as potential implications for patient safety.

First epidemiological study of contact dermatitis in Spain - 1977. Spanish Contact Dermatitis Research Group.

PubMed

Camarasa, J M

1979-01-01

The present work is the first epidemiological study carried out by the Spanish Contact Dermatitis Research Group during 1977. During this year 2806 patients were studied with patch test among 30873 dermatological patients. The 60-62% of the totality had reactivity to one or more patches. Four major groups of allergens were able to consider, following the incidence in their power of sensitize. First group with strong incidence include: Nickel, Chromate, Cobalt, T.M.T.D.,P.P.D.A., Mercapto mix., and Wood tars. Second and third groups with medium incidence contain: Caines, Carbonates, Neomycin, Balsam of Peru, Mercury, Lanolin, Naphtyl mix., Formaldehyde, Benzalkonium chloride, P. P. D. A. mix, and Turpentine. Four group show very low incidence substances, as: Epoxi, Sulfonamides, Etilendiamine, Parabens, Chinoform, Colophony and Cinnamon oil. Few comments about age and occupations are included.

FY 2017 Center Innovation Fund Annual Report - Highlights/Abstract section

NASA Technical Reports Server (NTRS)

Hintze, Paul; Youngquist, Robert C.; Massa, Gioia D.; Meier, Anne J.

2017-01-01

This project evaluated the feasibility of low pressure cold plasma (CP) for two applications: disinfection of produce grown in space and sterilization of medical equipment in space. Currently there is no ISS capability for disinfecting pick and eat crops, food utensils, food production areas, or medical devices. This deficit is extended to projected long duration missions. Small, portable, cold plasma devices would provide an enhanced benefit to crew health and address issues concerning microbial cross contamination. The technology would contribute to the reduction of solid waste since currently crews utilize benzalkonium chloride wet wipes for cleaning surfaces and might use PRO-SAN wipes for cleaning vegetables. CP cleaning/disinfection/sterilization can work on many surfaces, including all metals, most polymers, and this project evaluated produce. Therefore CP provides a simple system that has many different cleaning application in space: produce, medical equipment, cutlery, miscellaneous tools.

Testing a new alcohol-free hand sanitizer to combat infection.

PubMed

Dyer, D L; Gerenraich, K B; Wadhams, P S

1998-08-01

Universal precautions require that perioperative health care personnel wash their hand before and after all patient contact. Time constraints, however, can make adhering to universal precautions, including proper hand washing, difficult. Some perioperative health care workers, therefore, routinely use rise-free hand sanitizers to supplement normal hand washing. This study evaluated immediate and persistent antimicrobial effectiveness of two alcohol--containing hand sanitizers and a novel surfactant, allantoin, benzalkonium chloride (SAB) hand sanitizer using a federally approved effectiveness protocol. Results indicate that all three products were equally effective after a single application. After repeated use, the alcohol-containing sanitizers did not meet federal performance standards, and the alcohol-free sanitizer did. These properties and others illustrated in this article indicate that the nonflammable, alcohol-free SAB hand sanitizer is the most favorable of the rise-free hand sanitizer formulas for normal hand washing.

Endocrine cells in the denervated intestine

PubMed Central

Santos, Gilda C; Zucoloto, Sérgio; Garcia, Sérgio B

2000-01-01

This study deals with the effects of myenteric denervation of the proximal jejunum on endocrine cell population of the crypt-villus unit, 5 months after treatment with benzalkonium chloride (BAC). Male Wistar albino rats weighing on average 100 g were allocated to two groups: the BAC group − the proximal jejunal serosa was treated with 2 mm BAC for 30 min, and the control group − treated with saline solution (0,9% NaCl). There was a significant reduction in neurone number in the jejunal myenteric plexus of the BAC group and the endocrine cell population (serotoninergic and argyrophilic cells) was significantly increased in this intestine segment. In conclusion, the present findings provide further evidence that the myenteric denervation induced by BAC may lead to the development of a local imbalance of the neurotransmitters, with a consequent induction of enteroendocrine cell (argyrophilic and serotoninergic cells) hyperplasia in the crypt and villus. PMID:10971748

Commonly used disinfectants fail to eradicate Salmonella enterica biofilms from food contact surface materials.

PubMed

Corcoran, M; Morris, D; De Lappe, N; O'Connor, J; Lalor, P; Dockery, P; Cormican, M

2014-02-01

Salmonellosis is the second most common cause of food-borne illness worldwide. Contamination of surfaces in food processing environments may result in biofilm formation with a risk of food contamination. Effective decontamination of biofilm-contaminated surfaces is challenging. Using the CDC biofilm reactor, the activities of sodium hypochlorite, sodium hydroxide, and benzalkonium chloride were examined against an early (48-h) and relatively mature (168-h) Salmonella biofilm. All 3 agents result in reduction in viable counts of Salmonella; however, only sodium hydroxide resulted in eradication of the early biofilm. None of the agents achieved eradication of mature biofilm, even at the 90-min contact time. Studies of activity of chemical disinfection against biofilm should include assessment of activity against mature biofilm. The difficulty of eradication of established Salmonella biofilm serves to emphasize the priority of preventing access of Salmonella to postcook areas of food production facilities.

Interaction between chlorhexidine digluconate and EDTA.

PubMed

Rasimick, Brian J; Nekich, Michelle; Hladek, Megan M; Musikant, Barry L; Deutsch, Allan S

2008-12-01

The combination of chlorhexidine and EDTA produces a white precipitate. The aim of this study was to determine if the precipitate involves the chemical degradation of chlorhexidine. The precipitate was produced and redissolved in a known amount of dilute trifluoroacetic acid. The amount of chlorhexidine and EDTA present in the dissolved precipitate was determined by reverse-phase high performance liquid chromatography (HPLC) with ultraviolet detection at 288 nm. More than 90% of the precipitate's mass was found to be EDTA or chlorhexidine. The remainder is suspected to be water, gluconate, and sodium. Parachloroaniline, a potentially carcinogenic decomposition product of chlorhexidine, was not detected in the precipitate (the limit of detection was 1%). The molar ratio of chlorhexidine to EDTA in the precipitate was about 1.6 to 1. Based on the results, chlorhexidine forms a salt with EDTA rather than undergoing a chemical reaction.

Contact allergy to chlorhexidine in a tertiary dermatology clinic in Denmark.

PubMed

Opstrup, Morten S; Johansen, Jeanne D; Zachariae, Claus; Garvey, Lene H

2016-01-01

Chlorhexidine is a widely used disinfectant in the healthcare setting and in cosmetic products. A high prevalence of chlorhexidine contact allergy was reported in Denmark in the 1980s (2.0-5.4% of patients patch tested). It is unknown whether the prevalence is still high, which products cause the contact allergy, and whether accidental re-exposure occurs in some patients. To estimate the prevalence of chlorhexidine contact allergy in a tertiary dermatology clinic in Denmark; to investigate whether patch testing with both chlorhexidine diacetate and chlorhexidine digluconate is necessary; to investigate how many patients have combined immediate-type allergy and contact allergy; and to identify which products cause chlorhexidine contact allergy, and whether patients are accidentally re-exposed. This was a retrospective study including all patients patch tested with chlorhexidine during 2003-2013 at the Department of Dermato-Allergology at Copenhagen University Hospital Gentofte (n = 8497). All patients with a positive patch test reaction to chlorhexidine were sent a questionnaire comprising questions about the cause of the allergy and re-exposure. Overall, 1.0% (n = 82) of all patients patch tested with chlorhexidine were positive. A decrease in the prevalence was observed over time, most likely because of lowering of the test concentration from 1.0 to 0.5% in 2008. Of the 82 patients, 28 (0.3%) had positive test reactions to both chlorhexidine salts, 43 (0.5%) had a positive test reaction only to chlorhexidine diacetate, and 11 (0.1%) had a positive test reaction to chlorhexidine digluconate. Three patients were both patch test-positive and prick test-positive. A known cause of the allergy was reported by 19 patients (40%) in the questionnaire: the products used in the healthcare setting were mainly reported, but some reported cosmetic products. Accidental re-exposure was reported by 15 patients (32%), of whom 13 reported symptoms. The prevalence of chlorhexidine contact allergy does not seem to be higher in Denmark than in other European countries. Patch testing with both chlorhexidine diacetate and chlorhexidine digluconate may be beneficial. Testing for immediate-type allergy in patients with a positive patch test reaction to chlorhexidine is recommended. Chlorhexidine-containing products used in the healthcare setting and in cosmetics are potential causes of sensitization and allergy. Re-exposure is common, highlighting the fact that patients and healthcare personnel need to be well informed about possible sources of exposure. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Component Release and Mechanical Properties of Endodontic Sealers following Incorporation of Antimicrobial Agents

PubMed Central

Nicholson, John W.; Coleman, Nichola J.; Booth, Samantha; Dimkov, Aleksandar

2017-01-01

Root canal sealers with antimicrobial activity are highly beneficial; therefore, their antimicrobial properties could be improved by incorporation of antimicrobial agents. In the present study, the release of the quaternary ammonium compounds from endodontic sealers admixed with either benzalkonium chloride (BC) or cetylpyridinium chloride (CPC) at loadings of 2% wt was monitored. The effect of these additives on the compressive strengths and their release from the sealers was determined after 1 and 4 weeks. All of the materials studied were found to be capable of releasing antimicrobial additive in useful quantities. The release of CPC occurred to a statistically significant greater extent than BC for all materials. The addition of both BC and CPC generally decreased the compressive strength of all the endodontic sealers, with the exception of CPC in AH Plus, where the compressive strength was significantly increased. This suggests that, for these endodontic sealers, the antimicrobial additives alter the setting chemistry. AH Plus is an epoxy-based material cured with an amine, and in this case the increase in compressive strength with CPC is attributed to an enhanced cure reaction with this system. In all other cases, the additive inhibited the cure reaction to a greater or lesser extent. PMID:28620615

Chlorhexidine digluconate effects on planktonic growth and biofilm formation in some field isolates of animal bacterial pathogens.

PubMed

Ebrahimi, Azizollah; Hemati, Majid; Habibian Dehkordi, Saeed; Bahadoran, Shahab; Khoshnood, Sheida; Khubani, Shahin; Dokht Faraj, Mahdi; Hakimi Alni, Reza

2014-05-01

To study chlorhexidine digluconate disinfectant effects on planktonic growth and biofilm formation in some bacterial field isolates from animals. The current study investigated chlorhexidine digluconate effects on planktonic growth and biofilm formation in some field isolates of veterinary bacterial pathogens. Forty clinical isolates of Escherichia coli, Salmonella serotypes, Staphylococcus. aureus and Streptococcus agalactiae (10 isolates for each) were examined for chlorhexidine digluconate effects on biofilm formation and planktonic growth using microtiter plates. In all of the examined strains in the presence of chlorhexidine digluconate, biofilm development and planktonic growth were affected at the same concentrations of the disinfectant. Chlorhexidine digluconate inhibited the planktonic growth of different bacterial species at sub-MICs. But they were able to induce biofilm development of the E. coli, Salmonella spp., S. aureus and Str. agalactiae strains. Bacterial resistance against chlorhexidine is increasing. Sub-MIC doses of chlorhexidine digluconate can stimulate the formation of biofilm strains.

Prevalence of Chlorhexidine-Resistant Methicillin-Resistant Staphylococcus aureus following Prolonged Exposure

PubMed Central

Millar, Eugene V.; Crawford, Katrina B.; Cui, Tianyuan; Lanier, Jeffrey B.; Tribble, David R.; Ellis, Michael W.

2014-01-01

Chlorhexidine has been increasingly utilized in outpatient settings to control methicillin-resistant Staphylococcus aureus (MRSA) outbreaks and as a component of programs for MRSA decolonization and prevention of skin and soft-tissue infections (SSTIs). The objective of this study was to determine the prevalence of chlorhexidine resistance in clinical and colonizing MRSA isolates obtained in the context of a community-based cluster-randomized controlled trial for SSTI prevention, during which 10,030 soldiers were issued chlorhexidine for body washing. We obtained epidemiological data on study participants and performed molecular analysis of MRSA isolates, including PCR assays for determinants of chlorhexidine resistance and high-level mupirocin resistance and pulsed-field gel electrophoresis (PFGE). During the study period, May 2010 to January 2012, we identified 720 MRSA isolates, of which 615 (85.4%) were available for molecular analysis, i.e., 341 clinical and 274 colonizing isolates. Overall, only 10 (1.6%) of 615 isolates were chlorhexidine resistant, including three from the chlorhexidine group and seven from nonchlorhexidine groups (P > 0.99). Five (1.5%) of the 341 clinical isolates and five (1.8%) of the 274 colonizing isolates harbored chlorhexidine resistance genes, and four (40%) of the 10 possessed genetic determinants for mupirocin resistance. All chlorhexidine-resistant isolates were USA300. The overall prevalence of chlorhexidine resistance in MRSA isolates obtained from our study participants was low. We found no association between extended chlorhexidine use and the prevalence of chlorhexidine-resistant MRSA isolates; however, continued surveillance is warranted, as this agent continues to be utilized for infection control and prevention efforts. PMID:24841265

Effects of benzalkonium chloride- or polyquad-preserved fixed combination glaucoma medications on human trabecular meshwork cells

PubMed Central

Ammar, David A.

2011-01-01

Purpose We investigated the potential short and long-term effects in cultured human trabecular meshwork (TM) cells of various topical glaucoma formulations containing different preservatives. Methods We tested the fixed combination medications 0.004% travoprost plus 0.5% timolol preserved with either 0.015% benzalkonium chloride (BAK; DuoTrav®), or with 0.001% polyquad (PQ; DuoTrav® BAK-free); and 0.005% latanoprost plus 0.5% timolol preserved with 0.020% BAK (Xalacom®). Also tested was a range of BAK concentrations (0.001%–0.020%) in balanced salt solution (BSS). Cells were treated for 25 min at 37 °C with solutions diluted 1:10 and 1:100 to mimic the reduced penetration of topical preparations to the anterior chamber. The percentage of live cells was determined immediately after treatment through the uptake of the fluorescent vital dye calcein-AM. To determine any long-term effects, we assayed release of matrix metalloproteinase 9 (MMP-9) and apoptosis 24 h after treatments. Results BAK demonstrated a dose-dependent reduction in TM cell viability, ranging from 71±5% live cells at 0.001% BAK (diluted 1:10) to 33±3% live cells at 0.020% BAK (diluted 1:10). Travoprost (0.004%) plus 0.5% timolol preserved with 0.015% BAK had statistically fewer live TM cells (79±7%) than the same preparation preserved with 0.001% polyquad® (PQ; 93±1%; p<0.001). Latanoprost plus timolol preserved with 0.020% BAK (29±9% live cells) was similar to the 0.020% BAK (33±3%) treatment. However, travoprost plus timolol preserved in 0.015% BAK had significantly more live cells (83±12%) than the 1:10 dilution of 0.015% BAK (49±10%). We also found 0.020% BAK (diluted 1:100) resulted in elevated levels of extracellular MMP-9 at 24 h. Conclusions These results demonstrate that the substitution of the preservative BAK from topical ophthalmic drugs results in greater in vitro viability of TM cells. Travoprost with timolol, but not latanoprost with timolol, countered some of the toxic BAK effects. BAK treatment appeared to cause elevated levels of MMP-9, a matrix metalloproteinase implicated in the pathogenesis of glaucoma. PMID:21750606

Effectiveness of ophthalmic solution preservatives: a comparison of latanoprost with 0.02% benzalkonium chloride and travoprost with the sofZia preservative system.

PubMed

Ryan, Gerard; Fain, Joel M; Lovelace, Cherie; Gelotte, Karl M

2011-04-21

Although in vitro and in vivo laboratory studies have suggested that benzalkonium chloride (BAK) in topical ophthalmic solutions may be detrimental to corneal epithelial cells, multiple short- and long-term clinical studies have provided evidence supporting the safety of BAK. Despite the conflicting evidence, BAK is the most commonly used preservative in ophthalmic products largely due to its proven antimicrobial efficacy. This study was designed to characterize the antimicrobial performance of two commonly used topical ocular hypotensive agents that employ different preservative systems: latanoprost 0.005% with 0.02% BAK and travoprost 0.004% with sofZia, a proprietary ionic buffer system. Each product was tested for antimicrobial effectiveness by European Pharmacopoeia A (EP-A) standards, the most stringent standards of the three major compendia, which specify two early sampling time points (6 and 24 hours) not required by the United States Pharmacopeia or Japanese Pharmacopoeia. Aliquots were inoculated with between 10(5) and 10(6) colony-forming units of the test organisms: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Aspergillus brasiliensis. Sampling and enumeration were conducted at protocol-defined time points through 28 days. BAK-containing latanoprost met EP-A criteria by immediately reducing all bacterial challenge organisms to the test sensitivity and fungal challenges within the first six hours while the preservative activity of travoprost with sofZia did not. Complete bacterial reduction by travoprost with sofZia was not shown until seven days into the test, and fungal reduction never exceeded the requisite 2 logs during the 28-day test. Travoprost with sofZia also did not meet EP-B criteria due to its limited effectiveness against Staphylococcus aureus. Both products satisfied United States and Japanese pharmacopoeial criteria. Latanoprost with 0.02% BAK exhibited more effective microbial protection than travoprost with sofZia using rates of microbial reduction, time to no recovery for all challenges and evaluation against EP-A criteria as measures. The rapid and complete reduction of all microbial challenges demonstrates that antimicrobial activity of latanoprost with 0.02% BAK exceeds that of travoprost with sofZia preservative system in these products and provides a more protective environment in the event of contamination and subsequent exposure to microorganisms during use.

Effectiveness of ophthalmic solution preservatives: a comparison of latanoprost with 0.02% benzalkonium chloride and travoprost with the sofZia preservative system

PubMed Central

2011-01-01

Background Although in vitro and in vivo laboratory studies have suggested that benzalkonium chloride (BAK) in topical ophthalmic solutions may be detrimental to corneal epithelial cells, multiple short- and long-term clinical studies have provided evidence supporting the safety of BAK. Despite the conflicting evidence, BAK is the most commonly used preservative in ophthalmic products largely due to its proven antimicrobial efficacy. This study was designed to characterize the antimicrobial performance of two commonly used topical ocular hypotensive agents that employ different preservative systems: latanoprost 0.005% with 0.02% BAK and travoprost 0.004% with sofZia, a proprietary ionic buffer system. Methods Each product was tested for antimicrobial effectiveness by European Pharmacopoeia A (EP-A) standards, the most stringent standards of the three major compendia, which specify two early sampling time points (6 and 24 hours) not required by the United States Pharmacopeia or Japanese Pharmacopoeia. Aliquots were inoculated with between 105 and 106 colony-forming units of the test organisms: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Aspergillus brasiliensis. Sampling and enumeration were conducted at protocol-defined time points through 28 days. Results BAK-containing latanoprost met EP-A criteria by immediately reducing all bacterial challenge organisms to the test sensitivity and fungal challenges within the first six hours while the preservative activity of travoprost with sofZia did not. Complete bacterial reduction by travoprost with sofZia was not shown until seven days into the test, and fungal reduction never exceeded the requisite 2 logs during the 28-day test. Travoprost with sofZia also did not meet EP-B criteria due to its limited effectiveness against Staphylococcus aureus. Both products satisfied United States and Japanese pharmacopoeial criteria. Conclusions Latanoprost with 0.02% BAK exhibited more effective microbial protection than travoprost with sofZia using rates of microbial reduction, time to no recovery for all challenges and evaluation against EP-A criteria as measures. The rapid and complete reduction of all microbial challenges demonstrates that antimicrobial activity of latanoprost with 0.02% BAK exceeds that of travoprost with sofZia preservative system in these products and provides a more protective environment in the event of contamination and subsequent exposure to microorganisms during use. PMID:21510881

Variations in biofilm formation, desiccation resistance and Benzalkonium chloride susceptibility among Listeria monocytogenes strains isolated in Canada.

PubMed

Piercey, Marta J; Ells, Timothy C; Macintosh, Andrew J; Truelstrup Hansen, Lisbeth

2017-09-18

Listeria monocytogenes is a pathogenic foodborne microorganism noted for its ability to survive in the environment and food processing facilities. Survival may be related to the phenotype of individual strains including the ability to form biofilms and resist desiccation and/or sanitizer exposure. The objectives of this research were to compare 14 L. monocytogenes strains isolated from blood (3), food (6) and water (5) with respect to their benzalkonium chloride (BAC) sensitivity, desiccation resistance, and ability to form biofilm. Correlations were tested between those responses, and the presence of the SSI-1 (Stress Survival Islet) and LGI1/CC8 (Listeria Genomic Island 1 in a clonal complex 8 background) genetic markers. Genetic sequences from four strains representing different phenotypes were also probed for predicted amino acid differences in biofilm, desiccation, and membrane related genes. The water isolates were among the most desiccation susceptible strains, while strains exhibiting desiccation resistance harboured SSI-1 or both the SSI-1 and LGI1/CC8 markers. BAC resistance was greatest in planktonic LGI1/CC8 cells (relative to non-LGI1/CC8 cells), and higher BAC concentrations were also needed to inhibit the formation of biofilm by LGI1/CC8 strains during incubation for 48h and 6days compared to other strains. Formation of biofilm on stainless steel was not significantly (p>0.05) different among the strains. Analysis of genetic sequence data from desiccation and BAC sensitive (CP4 5-1, CP5 2-3, both from water), intermediate (Lm568, food) and desiccation and BAC resistant (08 5578, blood, human outbreak) strains led to the finding of amino acid differences in predicted functional protein domains in several biofilm, desiccation and peptidoglycan related genes (e.g., lmo0263, lmo0433, lmo0434, lmo0771, lmo0973, lmo1080, lmo1224, lmo1370, lmo1744, and lmo2558). Notably, the LGI1/CC8 strain 08-5578 had a frameshift mutation in lmo1370, a gene previously associated with desiccation resistance. In conclusion, the more desiccation and BAC resistant LGI1/CC8 isolates may pose a challenge for sanitation efforts. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Hyperosmolarity potentiates toxic effects of benzalkonium chloride on conjunctival epithelial cells in vitro

PubMed Central

Godefroy, David; Riancho, Luisa; Rostène, William; Baudouin, Christophe; Brignole-Baudouin, Françoise

2012-01-01

Purpose Benzalkonium chloride (BAK), the most commonly used preservative in eye drops, is known to induce ocular irritation symptoms and dry eye in long-term treated patients and animal models. As tear film hyperosmolarity is diagnostic of some types of dry eye disease, we determined in vitro on conjunctival epithelial cells the cytoxicity of BAK in hyperosmolar conditions through cell viability, apoptosis, and oxidative stress assays. Methods The Wong Kilbourne derivative of Chang conjunctival epithelial cells were cultured for 24 h or 48 h either in NaCl-induced hyperosmolar conditions (400–425–500 mOsM), in low concentrations of BAK (10−4%, 3.10−4%, and 5.10−4%), or in combination of both. We investigated cell viability through lysosomal integrity evaluation, cell death (cell membrane permeability and chromatin condensation), and oxidative stress (reactive oxygen species, superoxide anion) using spectrofluorimetry. Immunohistochemistry was performed for cytoskeleton shrinkage (phalloidin staining), mitochondrial permeability transition pore (cytochrome c release), the apoptosis effector active caspase-3, and the caspase-independent apoptosis factor AIF. We also observed early effects induced by the experimental conditions on the conjunctival cell layers using phase contrast imaging of live cells. Results As compared to standard culture solutions, hyperosmolar stress potentiated BAK cytotoxicity on conjunctival cells through the induction of oxidative stress; reduction of cell viability; cell membrane permeability increase; cell shrinkage with cell blebbing, as shown in phase contrast imaging of live cells; and chromatin condensation. Like BAK, but to a much lesser extent, hyperosmolarity increased cell death in a concentration-dependent manner through a caspase-dependent apoptosis characterized by a release of cytochrome c in the cytoplasm from mitochondria and the activation of caspase-3. Moreover, the caspase-independent apoptosis factor AIF was found translocated from mitochondria to the nucleus in both conditions. Conclusions This study showed increased cytotoxic effects of BAK in hyperosmotic conditions, with characteristic cell death processes, namely caspase-dependent and independent apoptosis and oxidative stress. As BAK is known to disrupt tear film, which could promote evaporative dry eye and tear hyperosmolarity, BAK could promote the conditions enhancing its own cytotoxicity. This in vitro hyperosmolarity model thus highlights the risk of inducing a vicious cycle and the importance of avoiding BAK in patients with dry eye conditions. PMID:22529703

Hyperosmolarity potentiates toxic effects of benzalkonium chloride on conjunctival epithelial cells in vitro.

PubMed

Clouzeau, Chloé; Godefroy, David; Riancho, Luisa; Rostène, William; Baudouin, Christophe; Brignole-Baudouin, Françoise

2012-01-01

Benzalkonium chloride (BAK), the most commonly used preservative in eye drops, is known to induce ocular irritation symptoms and dry eye in long-term treated patients and animal models. As tear film hyperosmolarity is diagnostic of some types of dry eye disease, we determined in vitro on conjunctival epithelial cells the cytoxicity of BAK in hyperosmolar conditions through cell viability, apoptosis, and oxidative stress assays. The Wong Kilbourne derivative of Chang conjunctival epithelial cells were cultured for 24 h or 48 h either in NaCl-induced hyperosmolar conditions (400-425-500 mOsM), in low concentrations of BAK (10(-4)%, 3.10(-4)%, and 5.10(-4)%), or in combination of both. We investigated cell viability through lysosomal integrity evaluation, cell death (cell membrane permeability and chromatin condensation), and oxidative stress (reactive oxygen species, superoxide anion) using spectrofluorimetry. Immunohistochemistry was performed for cytoskeleton shrinkage (phalloidin staining), mitochondrial permeability transition pore (cytochrome c release), the apoptosis effector active caspase-3, and the caspase-independent apoptosis factor AIF. We also observed early effects induced by the experimental conditions on the conjunctival cell layers using phase contrast imaging of live cells. As compared to standard culture solutions, hyperosmolar stress potentiated BAK cytotoxicity on conjunctival cells through the induction of oxidative stress; reduction of cell viability; cell membrane permeability increase; cell shrinkage with cell blebbing, as shown in phase contrast imaging of live cells; and chromatin condensation. Like BAK, but to a much lesser extent, hyperosmolarity increased cell death in a concentration-dependent manner through a caspase-dependent apoptosis characterized by a release of cytochrome c in the cytoplasm from mitochondria and the activation of caspase-3. Moreover, the caspase-independent apoptosis factor AIF was found translocated from mitochondria to the nucleus in both conditions. This study showed increased cytotoxic effects of BAK in hyperosmotic conditions, with characteristic cell death processes, namely caspase-dependent and independent apoptosis and oxidative stress. As BAK is known to disrupt tear film, which could promote evaporative dry eye and tear hyperosmolarity, BAK could promote the conditions enhancing its own cytotoxicity. This in vitro hyperosmolarity model thus highlights the risk of inducing a vicious cycle and the importance of avoiding BAK in patients with dry eye conditions.

Effects of benzalkonium chloride- or polyquad-preserved fixed combination glaucoma medications on human trabecular meshwork cells.

PubMed

Ammar, David A; Kahook, Malik Y

2011-01-01

We investigated the potential short and long-term effects in cultured human trabecular meshwork (TM) cells of various topical glaucoma formulations containing different preservatives. We tested the fixed combination medications 0.004% travoprost plus 0.5% timolol preserved with either 0.015% benzalkonium chloride (BAK; DuoTrav®), or with 0.001% polyquad (PQ; DuoTrav(®) BAK-free); and 0.005% latanoprost plus 0.5% timolol preserved with 0.020% BAK (Xalacom(®)). Also tested was a range of BAK concentrations (0.001%-0.020%) in balanced salt solution (BSS). Cells were treated for 25 min at 37 °C with solutions diluted 1:10 and 1:100 to mimic the reduced penetration of topical preparations to the anterior chamber. The percentage of live cells was determined immediately after treatment through the uptake of the fluorescent vital dye calcein-AM. To determine any long-term effects, we assayed release of matrix metalloproteinase 9 (MMP-9) and apoptosis 24 h after treatments. BAK demonstrated a dose-dependent reduction in TM cell viability, ranging from 71±5% live cells at 0.001% BAK (diluted 1:10) to 33±3% live cells at 0.020% BAK (diluted 1:10). Travoprost (0.004%) plus 0.5% timolol preserved with 0.015% BAK had statistically fewer live TM cells (79±7%) than the same preparation preserved with 0.001% polyquad® (PQ; 93±1%; p<0.001). Latanoprost plus timolol preserved with 0.020% BAK (29±9% live cells) was similar to the 0.020% BAK (33±3%) treatment. However, travoprost plus timolol preserved in 0.015% BAK had significantly more live cells (83±12%) than the 1:10 dilution of 0.015% BAK (49±10%). We also found 0.020% BAK (diluted 1:100) resulted in elevated levels of extracellular MMP-9 at 24 h. These results demonstrate that the substitution of the preservative BAK from topical ophthalmic drugs results in greater in vitro viability of TM cells. Travoprost with timolol, but not latanoprost with timolol, countered some of the toxic BAK effects. BAK treatment appeared to cause elevated levels of MMP-9, a matrix metalloproteinase implicated in the pathogenesis of glaucoma. © 2011 Molecular Vision

Chlorhexidine Digluconate Effects on Planktonic Growth and Biofilm Formation in Some Field Isolates of Animal Bacterial Pathogens

PubMed Central

Ebrahimi, Azizollah; Hemati, Majid; Habibian Dehkordi, Saeed; Bahadoran, Shahab; Khoshnood, Sheida; Khubani, Shahin; Dokht Faraj, Mahdi; Hakimi Alni, Reza

2014-01-01

Background: To study chlorhexidine digluconate disinfectant effects on planktonic growth and biofilm formation in some bacterial field isolates from animals. Objectives: The current study investigated chlorhexidine digluconate effects on planktonic growth and biofilm formation in some field isolates of veterinary bacterial pathogens. Materials and Methods: Forty clinical isolates of Escherichia coli, Salmonella serotypes, Staphylococcus. aureus and Streptococcus agalactiae (10 isolates for each) were examined for chlorhexidine digluconate effects on biofilm formation and planktonic growth using microtiter plates. In all of the examined strains in the presence of chlorhexidine digluconate, biofilm development and planktonic growth were affected at the same concentrations of the disinfectant. Results: Chlorhexidine digluconate inhibited the planktonic growth of different bacterial species at sub-MICs. But they were able to induce biofilm development of the E. coli, Salmonella spp., S. aureus and Str. agalactiae strains. Conclusions: Bacterial resistance against chlorhexidine is increasing. Sub-MIC doses of chlorhexidine digluconate can stimulate the formation of biofilm strains. PMID:24872940

Gold Nanoparticle Conjugation Enhances the Antiacanthamoebic Effects of Chlorhexidine

PubMed Central

Aqeel, Yousuf; Siddiqui, Ruqaiyyah; Anwar, Ayaz; Shah, Muhammad Raza

2015-01-01

Acanthamoeba keratitis is a serious infection with blinding consequences and often associated with contact lens wear. Early diagnosis, followed by aggressive topical application of drugs, is a prerequisite in successful treatment, but even then prognosis remains poor. Several drugs have shown promise, including chlorhexidine gluconate; however, host cell toxicity at physiologically relevant concentrations remains a challenge. Nanoparticles, subcolloidal structures ranging in size from 10 to 100 nm, are effective drug carriers for enhancing drug potency. The overall aim of the present study was to determine whether conjugation with gold nanoparticles enhances the antiacanthamoebic potential of chlorhexidine. Gold-conjugated chlorhexidine nanoparticles were synthesized. Briefly, gold solution was mixed with chlorhexidine and reduced by adding sodium borohydride, resulting in an intense deep red color, indicative of colloidal gold-conjugated chlorhexidine nanoparticles. The synthesis was confirmed using UV-visible spectrophotometry that shows a plasmon resonance peak of 500 to 550 nm, indicative of gold nanoparticles. Further characterization using matrix-assisted laser desorption ionization-mass spectrometry showed a gold-conjugated chlorhexidine complex at m/z 699 ranging in size from 20 to 100 nm, as determined using atomic force microscopy. To determine the amoebicidal and amoebistatic effects, amoebae were incubated with gold-conjugated chlorhexidine nanoparticles. For controls, amoebae also were incubated with gold and silver nanoparticles alone, chlorhexidine alone, neomycin-conjugated nanoparticles, and neomycin alone. The findings showed that gold-conjugated chlorhexidine nanoparticles exhibited significant amoebicidal and amoebistatic effects at 5 μM. Amoebicidal effects were observed by parasite viability testing using a Trypan blue exclusion assay and flow-cytometric analysis using propidium iodide, while amoebistatic effects were observed using growth assays. In contrast, chlorhexidine alone, at a similar concentration, showed limited effects. Notably, neomycin alone or conjugated with nanoparticles did not show amoebicidal or amoebistatic effects. Pretreatment of A. castellanii with gold-conjugated chlorhexidine nanoparticles reduced amoeba-mediated host cell cytotoxicity from 90% to 40% at 5 μM. In contrast, chlorhexidine alone, at similar concentrations, had no protective effects for the host cells. Similarly, amoebae treated with neomycin alone or neomycin-conjugated nanoparticles showed no protective effects. Overall, these findings suggest that gold-conjugated chlorhexidine nanoparticles hold promise in the improved treatment of A. castellanii keratitis. PMID:26666949

Efficacy of chlorhexidine digluconate-containing formulations and other mouthrinses against periodontopathogenic microorganisms.

PubMed

Eick, Sigrun; Goltz, Susann; Nietzsche, Sandor; Jentsch, Holger; Pfister, Wolfgang

2011-09-01

To determine in vitro the action of chlorhexidine digluconate and different commercially available mouthrinses on oral microorganisms. Minimal inhibitory concentrations and possible induction of resistance by chlorhexidine digluconate, an essential oil-containing mouthwash and an amine fluoride/stannous fluoride solution, were determined against microorganisms normally found in the oral cavity (10 streptococci, 2 enterobacteria, 1 Candida albicans, 8 Porphyromonas gingivalis, 6 Aggregatibacter actinomycetemcomitans, and 1 Fusobacterium nucleatum). Further, the effect of a 1-minute exposure on cell and bacterial viability was studied. The susceptibility of the oral microorganisms to chlorhexidine digluconate ranged from 0.01% to 0.50%. Passages on agar plates containing subinhibitory concentrations of chlorhexidine digluconate resulted in a transitory moderate increase in the tolerance to chlorhexidine digluconate in five of the 24 isolates. After 1 minute of exposure, chlorhexidine digluconate solutions as well as the essential oil and the amine/stannous fluoride-containing solutions showed a high activity against the tested microorganisms. Commercially available chlorhexidine digluconate formulations (ie, those with antidiscoloration systems) were partly less efficient than the corresponding manually prepared chlorhexidine digluconate preparation. The determination of MTT resulted in a strong cytotoxicity of all tested preparations to gingival fibroblasts. The results indicate that most of the chlorhexidine digluconate formulations as well as essential oil and the amine fluoride/stannous fluoride solutions are active against oral microbes. Long-term use of these agents would not result in emergent antimicrobial resistance.

The incorporation of chlorhexidine in a two-step self-etching adhesive preserves dentin bond in vitro.

PubMed

Zhou, Jianfeng; Tan, Jianguo; Chen, Li; Li, Deli; Tan, Yao

2009-10-01

To investigate whether the incorporation of chlorhexidine in a two-step self-etching adhesive can preserve dentin bond strengths. Different amounts of 20% chlorhexidine digluconate were added directly to the primer of Clearfil SE Bond to prepare mixtures of four different concentrations of chlorhexidine: 0.05%, 0.1%, 0.5% and 1.0%. Sixteen extracted third molars were randomly divided into 4 groups. Each group corresponded to one of the four chlorhexidine concentrations. Each of the 16 teeth was sectioned into two halves. One half was bonded with Clearfil SE Bond without chlorhexidine, and the other half was bonded with Clearfil SE Bond containing different concentrations of chlorhexidine. Specimens were stored in 0.9% NaCl containing 0.02% sodium azide at 37 degrees C. Microtensile bond strengths were tested 24h after specimen preparation or 12 months later. The modes of fractures were examined under a stereomicroscope. Twelve-month storage resulted in significant bond strength reduction of all control groups (p<0.05). When incorporated in SE Bond primer, chlorhexidine preserved dentin bond in the 0.1%, 0.5% and 1.0% chlorhexidine group (p<0.05); in the 0.05% group, there is no statistical difference of bond strength between control group and experimental group tested at the 12-month period (p>0.05). When incorporated in the primer of Clearfil SE Bond, chlorhexidine can preserve dentin bond as long as the concentration of chlorhexidine in the primer is higher than or equal to 0.1%.

CHLORHEXIDINE INHIBITS L1 CELL ADHESION MOLECULE MEDIATED NEURITE OUTGROWTH IN VITRO

PubMed Central

Milstone, Aaron M.; Bamford, Penny; Aucott, Susan W.; Tang, Ningfeng; White, Kimberly R.; Bearer, Cynthia F.

2013-01-01

Background Chlorhexidine is a skin disinfectant that reduces skin and mucous membrane bacterial colonization and inhibits organism growth. Despite numerous studies assessing chlorhexidine safety in term infants, residual concerns have limited its use in hospitalized neonates, especially low birth weight preterm infants. The aim of this study was to assess the potential neurotoxicity of chlorhexidine on the developing central nervous system using a well-established in vitro model of neurite outgrowth that includes laminin and L1 cell adhesion molecule (L1) as neurite outgrowth promoting substrates. Methods Cerebellar granule neurons are plated on either poly L-lysine, L1 or laminin. Chlorhexidine, hexachlorophene or their excipients are added to the media. Neurons are grown for 24 h, then fixed and neurite length measured. Results Chlorhexidine significantly reduced the length of neurites grown on L1 but not laminin. Chlorhexidine concentrations as low as 125 ng/ml statistically significantly reduced neurite length on L1. Hexachlorophene did not affect neurite length. Conclusion Chlorhexidine at concentrations detected in the blood following topical applications in preterm infants specifically inhibited L1 mediated neurite outgrowth of cerebellar granule neurons. It is now vital to determine whether the blood brain barrier is permeable to chlorhexidine in preterm infants. PMID:24126818

Chlorhexidine-calcium phosphate nanoparticles - Polymer mixer based wound healing cream and their applications.

PubMed

Viswanathan, Kaliyaperumal; Monisha, P; Srinivasan, M; Swathi, D; Raman, M; Dhinakar Raj, G

2016-10-01

In this work, we developed a wound healing cream composed of two different polymers, namely chitosan and gelatin with chlorhexidine along with calcium phosphate nanoparticles. The physicochemical properties of the prepared cream were investigated based on SEM, EDX, Raman, FTIR and the results indicated that the cream contained gelatin, chitosan, calcium phosphate nanoparticles and chlorhexidine. The maximum swelling ratio studies indicated that the ratio was around of 52±2.2 at pH7.4 and the value was increased in acidic and alkaline pH. The antimicrobial activity was tested against bacteria and the results indicated that, both chlorhexidine and the hybrid cream devoid of chlorhexidine exhibited antimicrobial activity but the chlorhexidine impregnated cream showed three fold higher antimicrobial activity than without chlorhexidine. In vivo wound healing promoting activities of hybrid cream containing 0.4mg/L chlorhexidine were evaluated on surgically induced dermal wounds in mice. The results indicated that the cream with incorporated chlorhexidine significantly enhanced healing compared with the control samples. For the field validations, the veterinary clinical animals were treated with the cream and showed enhanced healing capacity. In conclusion, a simple and efficient method for design of a novel wound healing cream has been developed for veterinary applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Calcium-silicate mesoporous nanoparticles loaded with chlorhexidine for both anti- Enterococcus faecalis and mineralization properties.

PubMed

Fan, Wei; Li, Yanyun; Sun, Qing; Ma, Tengjiao; Fan, Bing

2016-10-21

In infected periapical tissues, Enterococcus faecalis is one of the most common dominant bacteria. Chlorhexidine has been proved to show strong antibacterial ability against E. faecalis but is ineffective in promoting mineralization for tissues around root apex. Mesoporous calcium-silicate nanoparticles are newly synthesized biomaterials with excellent ability to promote mineralization and carry-release bioactive molecules in a controlled manner. In this study, mesoporous calcium-silicate nanoparticles were functionalized with chlorhexidine and their releasing profile, antibacterial ability, effect on cell proliferation and in vitro mineralization property were evaluated. The chlorhexidine was successfully incorporated into mesoporous calcium-silicate nanoparticles by a mixing-coupling method. The new material could release chlorhexidine as well as Ca 2+ and SiO 3 2- in a sustained manner with an alkaline pH value under different conditions. The antimicrobial ability against planktonic E. faecalis was dramatically improved after chlorhexidine incorporation. The nanoparticles with chlorhexidine showed no negative effect on cell proliferation with low concentrations. On dentin slices, the new synthesized material demonstrated a similar inhibitory effect on E. faecalis as the chlorhexidine. After being immersed in SBF for 9 days, numerous apatite crystals could be observed on surfaces of the material tablets. Mesoporous calcium-silicate nanoparticles loaded with chlorhexidine exhibited release of ions and chlorhexidine, low cytotoxicity, excellent antibacterial ability and in vitro mineralization. This material could be developed into a new effective intra-canal medication in dentistry or a new bone defect filling material for infected bone defects.

Minimizing human infection from Escherichia coli O157:H7 using GUMBOS

PubMed Central

Cole, Marsha R.; Li, Min; Jadeja, Ravirajsinh; El-Zahab, Bilal; Hayes, Daniel; Hobden, Jeffery A.; Janes, Marlene E.; Warner, Isiah M.

2013-01-01

Objectives Reduction in faecal shedding of Shiga toxin-producing enterohaemorrhagic Escherichia coli (EHEC) in food-producing animals is a viable strategy to minimize human disease initiated by exposure to these microorganisms. To this end, an intervention strategy involving the electrostatic hybridization of two commonly used anti-infective agents for veterinary practice (i.e. chlorhexidine and ampicillin) was evaluated to curtail EHEC-transmitted disease from ruminant sources. Chlorhexidine di-ampicillin is a novel group of uniform material based on organic salts (GUMBOS) with inherent in vitro antibacterial activity that comes from its parent antimicrobial ions, chlorhexidine and ampicillin. Methods Antibacterial activities for chlorhexidine diacetate, sodium ampicillin, chlorhexidine di-ampicillin and stoichiometrically equivalent 1 : 2 chlorhexidine diacetate : sodium ampicillin were assessed using the serial 2-fold dilution method and time–kill studies against seven isolates of E. coli O157:H7 and one non-pathogenic E. coli 25922. Further studies to investigate synergistic interactions of reacted and stoichiometrically equivalent unreacted antimicrobial agents at MICs and possible mechanisms were also investigated. Results Synergism and in vitro antibacterial activities against EHEC were observed in this study, which suggests chlorhexidine di-ampicillin could be a useful reagent in reducing EHEC transmission and minimizing EHEC-associated infections. Likewise, chlorhexidine di-ampicillin reduced HeLa cell toxicity as compared with chlorhexidine diacetate or the stoichiometric combination of antimicrobial agents. Further results suggest that the mechanisms of action of chlorhexidine di-ampicillin and chlorhexidine diacetate against E. coli O157:H7 are similar. Conclusions Reacting antimicrobial GUMBOS as indicated in this study may enhance the approach to current combination drug therapeutic strategies for EHEC disease control and prevention. PMID:23447139

Minimizing human infection from Escherichia coli O157:H7 using GUMBOS.

PubMed

Cole, Marsha R; Li, Min; Jadeja, Ravirajsinh; El-Zahab, Bilal; Hayes, Daniel; Hobden, Jeffery A; Janes, Marlene E; Warner, Isiah M

2013-06-01

Reduction in faecal shedding of Shiga toxin-producing enterohaemorrhagic Escherichia coli (EHEC) in food-producing animals is a viable strategy to minimize human disease initiated by exposure to these microorganisms. To this end, an intervention strategy involving the electrostatic hybridization of two commonly used anti-infective agents for veterinary practice (i.e. chlorhexidine and ampicillin) was evaluated to curtail EHEC-transmitted disease from ruminant sources. Chlorhexidine di-ampicillin is a novel group of uniform material based on organic salts (GUMBOS) with inherent in vitro antibacterial activity that comes from its parent antimicrobial ions, chlorhexidine and ampicillin. Antibacterial activities for chlorhexidine diacetate, sodium ampicillin, chlorhexidine di-ampicillin and stoichiometrically equivalent 1 : 2 chlorhexidine diacetate : sodium ampicillin were assessed using the serial 2-fold dilution method and time-kill studies against seven isolates of E. coli O157:H7 and one non-pathogenic E. coli 25922. Further studies to investigate synergistic interactions of reacted and stoichiometrically equivalent unreacted antimicrobial agents at MICs and possible mechanisms were also investigated. Synergism and in vitro antibacterial activities against EHEC were observed in this study, which suggests chlorhexidine di-ampicillin could be a useful reagent in reducing EHEC transmission and minimizing EHEC-associated infections. Likewise, chlorhexidine di-ampicillin reduced HeLa cell toxicity as compared with chlorhexidine diacetate or the stoichiometric combination of antimicrobial agents. Further results suggest that the mechanisms of action of chlorhexidine di-ampicillin and chlorhexidine diacetate against E. coli O157:H7 are similar. Reacting antimicrobial GUMBOS as indicated in this study may enhance the approach to current combination drug therapeutic strategies for EHEC disease control and prevention.

Initial effect of controlled release chlorhexidine on subgingival microorganisms.

PubMed

Daneshmand, Nazanin; Jorgensen, Michael G; Nowzari, Hessam; Morrison, John L; Slots, Jørgen

2002-10-01

Little or no data exist on the ability of subgingival application of PerioChip (2.5 mg chlorhexidine gluconate in a biodegradable chip; Astra Pharmaceuticals, Westborough, MA, USA) to suppress periodontopathic microorganisms. The present study compared the subgingival microbiota of periodontitis sites receiving the chlorhexidine chip plus scaling and root planing (Sc/Rp) or Sc/Rp alone. Seven males and six females, mean age 49 years, with moderate to advanced periodontitis participated in the study. In each patient, two bilateral pockets probing 6-7 mm were randomly assigned to treatment by chlorhexidine chip + Sc/Rp, or by Sc/Rp alone. Subgingival placement of chlorhexidine chips was carried out according to the manufacturer's instructions. Sc/Rp was performed with hand instruments for at least 10 min in each study tooth. Subgingival samples were collected by paper-points at baseline, at 2 weeks and at 4 weeks post-treatment. Anaerobic culture methods were used for microbial isolation and identification. The microbiologic examination was carried out blindly. Microbiological data were evaluated by a repeated measures analysis of variance. No statistical difference was found in total colony counts between subgingival sites treated with chlorhexidine chip + Sc/Rp and those treated with Sc/Rp alone. Also, the percentage of major periodontal pathogens (Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Bacteroides forsythus) and the percentage of total periodontal pathogens (A. actinomycetemcomitans, P. gingivalis, B. forsythus, Prevotella intermedia-group, Fusobacterium, Eubacterium, Campylobacter rectus, Peptostreptococcus micros, Eikenella corrodens, enteric rods) were not significantly different between the chlorhexidine chip + Sc/Rp group and the Sc/Rp group. At baseline, A. actinomycetemcomitans was recovered from 4 chlorhexidine chip + Sc/Rp sites and 2 Sc/Rp sites, P. gingivalis from 5 chlorhexidine chip + Sc/Rp sites and 4 Sc/Rp sites, and B. forsythus from 9 chlorhexidine chip + Sc/Rp and 7 Sc/Rp sites. At 4 weeks, A. actinomycetemcomitans was detected in 2 chlorhexidine chip + Sc/Rp sites but not in any site receiving Sc/Rp, P. gingivalis in 2 chlorhexidine chip + Sc/Rp sites but not in any Sc/Rp site, and B. forsythus in 1 chlorhexidine chip + Sc/Rp and in 2 Sc/Rp sites. The present data obtained from bilateral periodontitis lesions of 13 adults suggest that chlorhexidine chip treatment of adult periodontitis lesions provides little or no additional antimicrobial benefits compared to thorough Sc/Rp alone.

Penetration of Chlorhexidine into Human Skin ▿

PubMed Central

Karpanen, T. J.; Worthington, T.; Conway, B. R.; Hilton, A. C.; Elliott, T. S. J.; Lambert, P. A.

2008-01-01

This study evaluated a model of skin permeation to determine the depth of delivery of chlorhexidine into full-thickness excised human skin following topical application of 2% (wt/vol) aqueous chlorhexidine digluconate. Skin permeation studies were performed on full-thickness human skin using Franz diffusion cells with exposure to chlorhexidine for 2 min, 30 min, and 24 h. The concentration of chlorhexidine extracted from skin sections was determined to a depth of 1,500 μm following serial sectioning of the skin using a microtome and analysis by high-performance liquid chromatography. Poor penetration of chlorhexidine into skin following 2-min and 30-min exposures to chlorhexidine was observed (0.157 ± 0.047 and 0.077 ± 0.015 μg/mg tissue within the top 100 μm), and levels of chlorhexidine were minimal at deeper skin depths (less than 0.002 μg/mg tissue below 300 μm). After 24 h of exposure, there was more chlorhexidine within the upper 100-μm sections (7.88 ± 1.37 μg/mg tissue); however, the levels remained low (less than 1 μg/mg tissue) at depths below 300 μm. There was no detectable penetration through the full-thickness skin. The model presented in this study can be used to assess the permeation of antiseptic agents through various layers of skin in vitro. Aqueous chlorhexidine demonstrated poor permeation into the deeper layers of the skin, which may restrict the efficacy of skin antisepsis with this agent. This study lays the foundation for further research in adopting alternative strategies for enhanced skin antisepsis in clinical practice. PMID:18676882

Chlorhexidine digluconate induces mitotic recombination in diploid cells of Aspergillus nidulans.

PubMed

Souza-Júnior, S A; Castro-Prado, M A A

2005-05-01

Chlorhexidine digluconate (1,1'-hexamethylene-bis[(5-p-clorophenyl)-biguanide]) is a bisbiguanidine antiseptic, used to decrease plaque formation and to control periodontal diseases. The determination of the frequency of mitotic crossing-over constitutes a very important method for detecting carcinogenic agents. The recombinogenic potential of chlorhexidine digluconate was evaluated on Aspergillus nidulans by the production of cells homozygous for the following nutritional markers: riboA1, pabaA124, biA1, methA17 and pyroA4. A. nidulans was exposed to three concentrations of chlorhexidine digluconate (1, 5, and 10 microM). Inhibition of colony development, conidiophore morphological alteration (cytotoxic effect), and the recombinogenic effect, indicated by homozygotization index (HI) values higher than 2.0, were observed for all concentrations of chlorhexidine digluconate. A homozygous pyro+//pyro+ diploid strain and a diploid homozygous for the recessive w gene were isolated from UT448//A757 diploid treated with chlorhexidine digluconate, emphasazing its recombinogenic potential. Although, beneficial effects of chlorhexidine, as an antiseptic agent, are reported in the literature, our results revealed that chlorhexidine digluconate, at less levels lowered those used clinically, caused toxic and recombinogenic effects on diploid A. nidulans strain.

Dissolution of pulp tissue by aqueous solution of chlorhexidine digluconate and chlorhexidine digluconate gel.

PubMed

Okino, L A; Siqueira, E L; Santos, M; Bombana, A C; Figueiredo, J A P

2004-01-01

To evaluate the activity of various root canal irrigants on bovine pulp tissue. The irrigants tested were: 0.5, 1.0 and 2.5% sodium hypochlorite; 2% aqueous solution of chlorhexidine digluconate; 2% chlorhexidine digluconate gel (Natrosol); and distilled water as control. Bovine pulp fragments were weighed and placed in contact with 20 mL of each tested substance in a centrifuge at 150 r.p.m. until total dissolution. Dissolution speed was calculated by dividing pulp weight by dissolution time. Statistical analysis was performed using the Kruskal-Wallis test. Distilled water and both solutions of chlorhexidine did not dissolve the pulp tissue within 6 h. Mean dissolution speeds for 0.5, 1.0 and 2.5% sodium hypochlorite solutions were 0.31, 0.43 and 0.55 mg min(-1), respectively. The solvent ability of chlorhexidine solutions was similar to that of distilled water. The results for sodium hypochlorite solutions, chlorhexidine solutions and distilled water were statistically different (P>0.01). Both chlorhexidine preparations and distilled water were not able to dissolve pulp tissue. All sodium hypochlorite solutions were efficient in dissolving pulp tissue; the dissolution speed varied with the concentration of the solution.

Sampling and analysis of quaternary ammonium compounds (QACs) traces in indoor atmosphere.

PubMed

Vincent, Guillaume; Kopferschmitt-Kubler, Marie Christine; Mirabel, Philippe; Pauli, Gabrielle; Millet, Maurice

2007-10-01

Quaternary Ammonium Compounds (QACs) are widely found in disinfectants used in hospitals. Benzalkonium chloride (BAC) and didecyldimethylammonium chloride (DDAC) predominate in the disinfecting formulations. These compounds are strong irritants and can play a role in the induction of Occupational Asthma among the professionals of health and cleaning. In order to evaluate the potential health effect of these quaternary ammonium compounds to hospital employers, the development of an analytical method for their quantification in indoor air was developed. DDAC aerosols are trapped by adsorption on XAD-2 resin SKC tube. The air in hospital buildings was sampled using a constant debit Gillian pump at a flow of 1.0 l/min (+/-5%). Ion Chromatography (IC) was chosen for the analysis of DDAC especially for its high sensitivity and specificity. The Limit of Detection (LOD) by IC for DDAC is 0.56 mug/ml. Therefore the LOD of atmospheric DDAC is 28 microg/m(3) with an air volume of 100 l and a desorption volume of 5 ml. All DDAC air samples were lower than the LOD of the analytical method by IC. Under the standard conditions of use of the disinfecting solutions (Surfanios, Ampholysine Plus and Amphospray 41), the insignificant volatility of DDAC would not seem to be able to contaminate the indoor hospital atmosphere during the disinfection process. However, the DDAC can contaminate working atmospheres if it is put in suspension by aerosolisation.

Alcoholic versus aqueous chlorhexidine for skin antisepsis: the AVALANCHE trial

PubMed Central

Charles, Daniel; Heal, Clare F.; Delpachitra, Meth; Wohlfahrt, Michael; Kimber, Debbie; Sullivan, Julie; Browning, Sheldon; Saednia, Sabine; Hardy, Alexandra; Banks, Jennifer; Buttner, Petra

2017-01-01

BACKGROUND: Preoperative skin antisepsis is routine practice. We compared alcoholic chlorhexidine with aqueous chlorhexidine for skin antisepsis to prevent surgical site infection after minor skin excisions in general practice. METHODS: We conducted this prospective, multicentre, randomized controlled trial in 4 private general practices in North Queensland, Australia, from October 2015 to August 2016. Consecutive adult patients presenting for minor skin excisions were randomly assigned to undergo preoperative skin antisepsis with 0.5% chlorhexidine in 70% ethanol (intervention) or 0.5% chlorhexidine aqueous solution (control). Our primary outcome was surgical site infection within 30 days of excision. We also measured the incidence of adverse reactions. RESULTS: A total of 916 patients were included in the study: 454 underwent antisepsis with alcoholic chlorhexidine and 462 with aqueous chlorhexidine. Of these, 909 completed follow-up. In the intention-to-treat analysis of cases available at follow-up, there was no significant difference in the incidence of surgical site infection between the alcoholic chlorhexidine arm (5.8%, 95% confidence interval [CI] 3.6% to 7.9%) and the aqueous chlorhexidine arm (6.8%, 95% CI 4.5% to 9.1%). The attributable risk reduction was 0.010 (95% CI –0.021 to 0.042), the relative risk was 0.85 (95% CI 0.51 to 1.41), and the number needed to treat to benefit was 100. Per protocol and sensitivity analyses produced similar results. The incidence of adverse reactions was low, with no difference between groups (p = 0.6). INTERPRETATION: There was no significant difference in efficacy between alcoholic and aqueous chlorhexidine for the prevention of surgical site infection after minor skin excisions in general practice. Trial registration: https://www.anzctr.org.au, no. ACTRN12615001045505 PMID:28790056

Mechanisms of Increased Resistance to Chlorhexidine and Cross-Resistance to Colistin following Exposure of Klebsiella pneumoniae Clinical Isolates to Chlorhexidine

PubMed Central

Bock, Lucy J.; Bonney, Laura C.

2016-01-01

ABSTRACT Klebsiella pneumoniae is an opportunistic pathogen that is often difficult to treat due to its multidrug resistance (MDR). We have previously shown that K. pneumoniae strains are able to “adapt” (become more resistant) to the widely used bisbiguanide antiseptic chlorhexidine. Here, we investigated the mechanisms responsible for and the phenotypic consequences of chlorhexidine adaptation, with particular reference to antibiotic cross-resistance. In five of six strains, adaptation to chlorhexidine also led to resistance to the last-resort antibiotic colistin. Here, we show that chlorhexidine adaptation is associated with mutations in the two-component regulator phoPQ and a putative Tet repressor gene (smvR) adjacent to the major facilitator superfamily (MFS) efflux pump gene, smvA. Upregulation of smvA (10- to 27-fold) was confirmed in smvR mutant strains, and this effect and the associated phenotype were suppressed when a wild-type copy of smvR was introduced on plasmid pACYC. Upregulation of phoPQ (5- to 15-fold) and phoPQ-regulated genes, pmrD (6- to 19-fold) and pmrK (18- to 64-fold), was confirmed in phoPQ mutant strains. In contrast, adaptation of K. pneumoniae to colistin did not result in increased chlorhexidine resistance despite the presence of mutations in phoQ and elevated phoPQ, pmrD, and pmrK transcript levels. Insertion of a plasmid containing phoPQ from chlorhexidine-adapted strains into wild-type K. pneumoniae resulted in elevated expression levels of phoPQ, pmrD, and pmrK and increased resistance to colistin, but not chlorhexidine. The potential risk of colistin resistance emerging in K. pneumoniae as a consequence of exposure to chlorhexidine has important clinical implications for infection prevention procedures. PMID:27799211

Resistance of bioparticles formed of phosphate-accumulating bacteria and zeolite to harsh environmental conditions.

PubMed

Ivankovic, Tomislav; Hrenovic, Jasna; Matonickin-Kepcija, Renata

2013-01-01

Extreme environmental conditions, such as pH fluctuations, high concentrations of toxicants or grazing of protozoa, can potentially be found in wastewater treatment systems. This study was carried out to provide specific evidence on how 'bioparticles' can resist these conditions. The term 'bioparticle' is used to describe a particle comprising natural zeolitized tuff with a developed biofilm of the phosphate-accumulating bacterial species, Acinetobacter junii, on the surface. The bacteria in the biofilm were protected from the negative influence of extremely low pH, high concentrations of benzalkonium-chloride and grazing by Paramecium caudatum and Euplotes affinis, even under conditions that caused complete eradication of planktonic bacteria. During an incubation of 24 h, the biofilms were maintained and bacteria detached from the bioparticles, thus bioaugmenting the wastewater. The bioparticles provided a safe environment for the survival of bacteria in harsh environmental conditions and could be used for successful bioaugmentation in wastewater treatment plants.

A new respirometric endpoint-based biosensor to assess the relative toxicity of chemicals on immobilized human cells.

PubMed

Dragone, Roberto; Frazzoli, Chiara; Grappelli, Claudio; Campanella, Luigi

2009-01-01

Several functional and biochemical parameters have been proposed as biomarkers of effect of environmental pollutants. A rapid biosensor working with immobilized human U-937 cells was developed and applied to environmentally relevant chemicals with different structures and toxicological pathways, i.e. benzalkonium chloride, clofibric acid, diclofenac, mercury nitrate, ofloxacin, and sodium dodecyl sulphate. Respiration of cells was relied upon as a comprehensive biochemical effect for screening purposes. Analytical parameter (DeltappmO(2)) and toxicological index (respiratory inhibition, delta%) measured after 1h of exposure were utilized for dose-response relationship study. Results (toxicity rating scales based on delta(50)% and steepness) were compared with those obtained by the same approach previously optimized on Saccharomyces cerevisiae. The toxicity rating scale obtained by the biomarker based on human mitochondrial and cell metabolic activities compared well with previous scale obtained on yeast cells and with available in-vivo acute toxicity indexes; respiration was confirmed as toxicological endpoint reliably measurable by the biosensor.

Intra-Abdominal Hypertension Causes Bacterial Growth in Lungs: An Animal Study

PubMed Central

Papakrivou, Eleni; Manoulakas, Efstratios; Mitroudi, Magda; Tepetes, Konstantinos; Papazoglou, Konstantinos; Zakynthinos, Epaminondas

2017-01-01

To study the effect of intra-abdominal hypertension (IAH) on the frequency of pneumonia with an experimental study, thirteen Sprague-Dawley rats were included. Eight out of thirteen animals were randomly assigned to receive 10 ml of benzalkonium chloride 0.2% (megacolon group) and five animals received 10 ml NaCl 0.9% (controls). Animals were anaesthetized by intramuscular delivery of ketamine. The incidence of positivity for bacteria lung tissue cultures and mesenteric lymph node cultures was assessed at the 21st day after animals' sacrification, or before in case of death. All megacolon group animals presented progressive increase of the abdomen and increased IAP (≥10 mmHg) whereas the frequency of their evacuations was almost eliminated. Controls presented normal evacuations, no sign of abdominal distention, and normal IAP. In megacolon group animals, there was evidence of significant amount of bacteria in lung cultures. In contrast, no bacteria were found in control animals. PMID:28357400

Reduction of illness absenteeism in elementary schools using an alcohol-free instant hand sanitizer.

PubMed

White, C G; Shinder, F S; Shinder, A L; Dyer, D L

2001-10-01

Hand washing is the most effective way to prevent the spread of communicable disease. The purpose of this double-blind, placebo-controlled study was to assess whether an alcohol-free, instant hand sanitizer containing surfactants, allantoin, and benzalkonium chloride could reduce illness absenteeism in a population of 769 elementary school children and serve as an effective alternative when regular soap and water hand washing was not readily available. Prior to the study, students were educated about proper hand washing technique, the importance of hand washing to prevent transmission of germs, and the relationship between germs and illnesses. Children in kindergarten through the 6th grade (ages 5-12) were assigned to the active or placebo hand-sanitizer product and instructed to use the product at scheduled times during the day and as needed after coughing or sneezing. Data on illness absenteeism were tracked. After 5 weeks, students using the active product were 33% less likely to have been absent because of illness when compared with the placebo group.

Antimicrobial drug resistance in Staphylococcus aureus isolated from cattle in Brazil.

PubMed

Pereira, M S; Siqueira-Júnior, J P

1995-06-01

Isolates of Staphylococcus aureus obtained from apparently healthy cattle in the State of Paraiba, Brazil were characterized in relation to resistance to 21 antimicrobial agents. Among the 46 isolates obtained, resistance to penicillin was most frequent, followed by resistance to cadmium, streptomycin, arsenate, tetracycline, mercury, erythromycin and kanamycin/neomycin. All isolates were susceptible to fusidic acid, ethidium bromide, cetrimide, chloramphenicol, benzalkonium chloride, doxycycline, gentamicin, methicillin, minocycline, novobiocin, rifamycin, tylosin and vancomycin. Only six isolates were susceptible to all the drugs tested. With respect to the antibiotics, multi-resistant isolates were uncommon. These results are probably a consequence of the peculiarities of local drug usage pressures. In relation to metal ions, resistance to mercury was rare while resistance to arsenate was relatively frequent, which contrasts with the situation for human Staph. aureus strains. After treatment with ethidium bromide, elimination of resistance to penicillin, tetracycline, streptomycin, erythromycin and cadmium was observed, which was consistent with the genetic determinants being plasmid-borne.

Effectiveness of Alpha-toxin Fab Monoclonal Antibody Therapy in Limiting the Pathology of Staphylococcus aureus Keratitis.

PubMed

Caballero, Armando R; Foletti, Davide L; Bierdeman, Michael A; Tang, Aihua; Arana, Angela M; Hasa-Moreno, Adela; Sangalang, Emma Ruth B; O'Callaghan, Richard J

2015-08-01

To investigate the effectiveness of a high-affinity human monoclonal antibody Fab fragment to Staphylococcus aureus alpha-toxin (LTM14 Fab) as therapy for S. aureus keratitis. A single topical drop of the LTM14 Fab antibody to alpha-toxin alone, or in 0.006% benzalkonium chloride (BAK), was applied every 30 min to S. aureus-infected rabbit corneas from 9 to 14 hours post-infection. Erosions and pathology were measured at 15 h post-infection. LTM14 Fab with BAK limited corneal erosions better than LTM14 Fab alone (p = 0.036), and both limited erosions compared to untreated eyes (p ≤ 0.0001). Overall pathology was similar in all groups (p ≥ 0.070), but iritis and chemosis were reduced by treatment (p ≤ 0.036). The high-affinity human monoclonal Fab fragment antibody (LTM14 Fab) to S. aureus alpha-toxin was effective in reducing corneal damage during S. aureus keratitis.

Low Sensitivity of Listeria monocytogenes to Quaternary Ammonium Compounds

PubMed Central

Mereghetti, L.; Quentin, R.; Marquet-Van Der Mee, N.; Audurier, A.

2000-01-01

Ninety-seven epidemiologically unrelated strains of Listeria monocytogenes were investigated for their sensitivities to quaternary ammonium compounds (benzalkonium chloride and cetrimide). The MICs for seven serogroup 1/2 strains were high. Three came from the environment and four came from food; none were isolated from human or animal samples. All 97 strains carried the mdrL gene, which encodes a multidrug efflux pump, and the orfA gene, a putative transcriptional repressor of mdrL. The absence of plasmids in four of the seven resistant strains and the conservation of resistance after plasmid curing suggested that the resistance genes are not plasmid borne. Moreover, PCR amplification and Southern blot hybridization experiments failed to find genes phylogenetically related to the qacA and smr genes, encoding multidrug efflux systems previously described for the genus Staphylococcus. The high association between nontypeability by phages and the loss of sensitivity to quaternary ammonium compounds are suggestive of an intrinsic resistance due to modifications in the cell wall. PMID:11055967

Influence of freezing stress on morphological alteration and biofilm formation by Listeria monocytogenes: relationship with cell surface hydrophobicity and membrane fluidity.

PubMed

Miladi, Hanene; Ammar, Emna; Ben Slama, Rihab; Sakly, Nawfel; Bakhrouf, Amina

2013-11-01

The morphological changes and adhesive property of three Listeria monocytogenes strains submitted to freezing stress (-20 °C) were studied. The atomic force micrographs showed a reduction in the cell size and an evolution to coccoid shape. The phenotypic slime production of L. monocytogenes and the expression of the adhesive gene were investigated before and after 10 months of incubation in salmon at -20°. Our results showed that after ten months, stressed stains become more adherent and able to produce slime. In addition, we noted that this pathogen presents same physiological changes to adapt to starvation conditions. The cellular fatty acids composition of adhered and floating cells of three L. monocytogenes strains was taken into consideration. The stressed strains presented different chain lengths and therefore an increase in the hydrophobicity level. Moreover, we noted that the adhesive property of L. monocytogenes strains affects the Benzalkonium chloride bacterial sensitivity which increased after biofilm formation.

Quantitative evaluation of dermatological antiseptics.

PubMed

Leitch, C S; Leitch, A E; Tidman, M J

2015-12-01

Topical antiseptics are frequently used in dermatological management, yet evidence for the efficacy of traditional generic formulations is often largely anecdotal. We tested the in vitro bactericidal activity of four commonly used topical antiseptics against Staphylococcus aureus, using a modified version of the European Standard EN 1276, a quantitative suspension test for evaluation of the bactericidal activity of chemical disinfectants and antiseptics. To meet the standard for antiseptic effectiveness of EN 1276, at least a 5 log10 reduction in bacterial count within 5 minutes of exposure is required. While 1% benzalkonium chloride and 6% hydrogen peroxide both achieved a 5 log10 reduction in S. aureus count, neither 2% aqueous eosin nor 1 : 10 000 potassium permanganate showed significant bactericidal activity compared with control at exposure periods of up to 1 h. Aqueous eosin and potassium permanganate may have desirable astringent properties, but these results suggest they lack effective antiseptic activity, at least against S. aureus. © 2015 British Association of Dermatologists.

Chlorhexidine with or without alcohol against biofilm formation: efficacy, adverse events and taste preference.

PubMed

Santos, Gabriela Otero Dos; Milanesi, Fernanda Carpes; Greggianin, Bruna Frizon; Fernandes, Marilene Issa; Oppermann, Rui Vicente; Weidlich, Patricia

2017-05-04

In recent years, different chlorhexidine formulations have been tested, including an alcohol-free alternative, but the effect of this solution on early biofilm formation is not clear. A crossover, randomized, double-blind clinical trial was conducted to evaluate the effect of two chlorhexidine solutions against supra- and subgingival biofilm formation (NCT#02656251). Thirty-five participants were randomized and asked to rinse twice daily with 15 ml of an alcohol-containing 0.12% chlorhexidine solution, an alcohol-free 0.12% chlorhexidine solution, or placebo. The study was conducted in three experimental periods of 4 days each, with a 10-day washout between the periods. All the experimental periods followed the same protocol, except that the solutions were switched. Biofilm distribution was evaluated every 24 hours by the Plaque-Free Zone Index, during 96 hours. Adverse events were self-reported and sensory evaluation was performed using a hedonic scale. Compared to the placebo, the chlorhexidine solutions resulted in a significantly higher number of surfaces free of plaque over 96 hours (p < 0.01), and were able to prevent subgingival biofilm formation (p < 0.01). The alcohol-free chlorhexidine solution was associated with a lower incidence of adverse events, compared with alcohol-containing chlorhexidine (p < 0.05); it also received better sensory evaluation and acceptance by trial participants, compared with the alcohol-containing chlorhexidine (p = 0.007), and had a similar inhibitory effect on the formation of supra- and subgingival biofilms.

Antibacterial Effect of Azadirachta indica (Neem) or Curcuma longa (Turmeric) against Enterococcus faecalis Compared with That of 5% Sodium Hypochlorite or 2% Chlorhexidine in vitro.

PubMed

Joy Sinha, Dakshita; D S Nandha, Kanwar; Jaiswal, Natasha; Vasudeva, Agrima; Prabha Tyagi, Shashi; Pratap Singh, Udai

2017-01-01

The purpose of this study was to compare the antibacterial properties of Azadirachta indica (neem) or Curcuma longa (turmeric) against Enterococcus faecalis with those of 5% sodium hypochlorite or 2% chlorhexidine as root canal irrigants in vitro. The activity of neem, chlorhexidine, sodium hypochlorite, or turmeric against E. faecalis was measured on agar plates using the agar diffusion method. The tube dilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the irrigants used. Chlorhexidine or neem exhibited the greatest antibacterial activity when used as endodontic irrigants against E. faecalis, followed by sodium hypochlorite. No statistically significant difference was observed between neem, sodium hypochlorite, or chlorhexidine. The MIC of neem was 1: 128, which was similar to that of chlorhexidine. The MBC for each of these irrigants was 1: 16. Neem yielded antibacterial activity equivalent to 2% chlorhexidine or sodium hypochlorite against E. faecalis, suggesting that it offers a promising alternative to the other root canal irrigants tested.

Daily Bathing with Chlorhexidine and Its Effects on Nosocomial Infection Rates in Pediatric Oncology Patients.

PubMed

Raulji, Chittalsinh M; Clay, Kristin; Velasco, Cruz; Yu, Lolie C

2015-01-01

Infections remain a serious complication in pediatric oncology patients. To determine if daily bathing with Chlorhexidine gluconate can decrease the rate of nosocomial infection in pediatric oncology patients, we reviewed rates of infections in pediatric oncology patients over a 14-month span. Intervention group received daily bath with Chlorhexidine, while the control group did not receive daily bath. The results showed that daily bath with antiseptic chlorhexidine as daily prophylactic antiseptic topical wash leads to decreased infection density amongst the pediatric oncology patients, especially in patients older than 12 years of age. Furthermore, daily chlorhexidine bathing significantly reduced the rate of hospital acquired infection in patients older than 12 years of age. The findings of this study suggest that daily bathing with chlorhexidine may be an effective measure of reducing nosocomial infection in pediatric oncology patients.

Regulation of the aceI multidrug efflux pump gene in Acinetobacter baumannii.

PubMed

Liu, Qi; Hassan, Karl A; Ashwood, Heather E; Gamage, Hasinika K A H; Li, Liping; Mabbutt, Bridget C; Paulsen, Ian T

2018-06-01

To investigate the function of AceR, a putative transcriptional regulator of the chlorhexidine efflux pump gene aceI in Acinetobacter baumannii. Chlorhexidine susceptibility and chlorhexidine induction of aceI gene expression were determined by MIC and quantitative real-time PCR, respectively, in A. baumannii WT and ΔaceR mutant strains. Recombinant AceR was prepared as both a full-length protein and as a truncated protein, AceR (86-299), i.e. AceRt, which has the DNA-binding domain deleted. The binding interaction of the purified AceR protein and its putative operator region was investigated by electrophoretic mobility shift assays and DNase I footprinting assays. The binding of AceRt with its putative ligand chlorhexidine was examined using surface plasmon resonance and tryptophan fluorescence quenching assays. MIC determination assays indicated that the ΔaceI and ΔaceR mutant strains both showed lower resistance to chlorhexidine than the parental strain. Chlorhexidine-induced expression of aceI was abolished in a ΔaceR background. Electrophoretic mobility shift assays and DNase I footprinting assays demonstrated chlorhexidine-stimulated binding of AceR with two sites upstream of the putative aceI promoter. Surface plasmon resonance and tryptophan fluorescence quenching assays suggested that the purified ligand-binding domain of the AceR protein was able to bind with chlorhexidine with high affinity. This study provides strong evidence that AceR is an activator of aceI gene expression when challenged with chlorhexidine. This study is the first characterization, to our knowledge, of a regulator controlling expression of a PACE family multidrug efflux pump.

Inhibitory effect of sodium hypochlorite and chlorhexidine digluconate in clinical isolates of Sporothrix schenckii.

PubMed

Madrid, Isabel Martins; Mattei, Antonella Souza; Santin, Rosema; dos Reis Gomes, Angelita; Cleff, Marlete Brum; Meireles, Mário Carlos Araújo

2012-05-01

The susceptibility of Sporothrix schenckii isolates from clinical cases of canine, feline and human sporotrichosis, and from the environment, was evaluated with 4% sodium hypochlorite and 6.6% chlorhexidine digluconate using the broth microdilution, agar diffusion and direct exposure techniques. The minimal inhibitory concentration was smaller than 0.8% for chlorhexidine digluconate and between 8% and 4% for sodium hypochlorite. Inhibition zones were not found in agar diffusion for sodium hypochlorite, and zones averaging 1.9 mm were found for chlorhexidine digluconate. In the direct exposure test, sodium hypochlorite demonstrated best performance at 20 min of contact, as chlorhexidine digluconate presented little antimicrobial activity. © 2011 Blackwell Verlag GmbH.

Influence of chlorhexidine digluconate concentration and application time on resin-dentin bond strength durability.

PubMed

Loguercio, Alessandro D; Stanislawczuk, Rodrigo; Polli, Luceli G; Costa, Jully A; Michel, Milton D; Reis, Alessandra

2009-10-01

Although it is known that chlorhexidine application may preserve resin-dentin bonds from degradation, the lowest optimal concentration and application time have yet to be established. This study evaluated the effects of different concentrations of chlorhexidine digluconate and different application times on the preservation of resin-dentin bonds formed using two etch-and-rinse adhesives. In experiment 1, after acid etching, the occlusal demineralized dentin was rewetted either with water or with 0.002, 0.02, 0.2, 2, or 4% chlorhexidine for 60 s. In experiment 2, the surfaces were rewetted with water, or with 0.002% or 2% chlorhexidine for 15 or 60 s. After this, both adhesives and composite resin were applied and light-cured. Bonded sticks (0.8 mm(2)) were tested under tension (0.5 mm min(-1)) immediately or after 6 months of storage in water. Two bonded sticks from each tooth were immersed in silver nitrate and analyzed quantitatively using scanning electron microscopy. Reductions in microtensile bond strengths and higher silver nitrate uptake were observed for both adhesives when the rewetting procedure was performed with water. Stable bonds were maintained for up to 6 months under all chlorhexidine conditions tested, irrespective of the chlorhexidine concentration and application time. The use of 0.002% chlorhexidine for 15 s seems to be sufficient to preserve resin-dentin interfaces over a 6-month period.

Measurements of chlorhexidine, p-chloroaniline, and p-chloronitrobenzene in saliva after mouth wash before and after operation with 0.2% chlorhexidine digluconate in maxillofacial surgery: a randomised controlled trial.

PubMed

Below, H; Assadian, O; Baguhl, R; Hildebrandt, U; Jäger, B; Meissner, K; Leaper, D J; Kramer, A

2017-02-01

Chlorhexidine gluconate is used to prevent the accumulation of dental plaque and gingivitis, infection of the surgical site, and ventilator-associated pneumonia in maxillofacial surgery, but it is not clear whether the metabolites of chlorhexidine are detectable in the patient's saliva at clinically relevant concentrations. Forty-three patients who had orofacial operations were randomised to use a 0.2% chlorhexidine gluconate (n=23), or an octenidine-based, chlorhexidine-free (n=20), mouthwash once preoperatively and three times daily for five postoperative days. After the first, 8.7 (23.3) mg/L chlorhexidine (0.7%-2.5% of the total amount used) was measured in saliva. The concentration increased to 15.2 (6.2) mg/L after the second rinse (first postoperative day), and peaked at 29.4 (11.2) mg/L on the fourth postoperative day. It remained detectable for up to 12hours after the last one, but was not detectable in serum or urine at any time. The potentially carcinogenic metabolite p-chloroaniline was detectable in saliva at higher concentrations in the chlorhexidine group (0.55mg/L) than the octenidine group (0.21mg/L), and p-chloronitrobenzene was detected in both groups in only minimal concentrations (0.001-0.21mg/L). Chlorhexidine gluconate mouthwashes do increase the concentration of p-chloroaniline, but a single use seems to be safe. Whether prolonged exposure over many years may have carcinogenic potential is still not clear. Based on the hitherto unknown kinetics of p-chloroaniline in saliva, the recent recommendation of the Federal Drug Administration (FDA) in the USA to limit the use of a chlorhexidine gluconate mouthwash to a maximum of six months seems to be justified. Copyright © 2016 The British Association of Oral and Maxillofacial Surgeons. All rights reserved.

Using a Systems Engineering Initiative for Patient Safety to Evaluate a Hospital-wide Daily Chlorhexidine Bathing Intervention.

PubMed

Caya, Teresa; Musuuza, Jackson; Yanke, Eric; Schmitz, Michelle; Anderson, Brooke; Carayon, Pascale; Safdar, Nasia

2015-01-01

We undertook a systems engineering approach to evaluate housewide implementation of daily chlorhexidine bathing. We performed direct observations of the bathing process and conducted provider and patient surveys. The main outcome was compliance with bathing using a checklist. Fifty-seven percent of baths had full compliance with the chlorhexidine bathing protocol. Additional time was the main barrier. Institutions undertaking daily chlorhexidine bathing should perform a rigorous assessment of implementation to optimize the benefits of this intervention.

Enhancing blood donor skin disinfection using natural oils.

PubMed

Alabdullatif, Meshari; Boujezza, Imen; Mekni, Mohamed; Taha, Mariam; Kumaran, Dilini; Yi, Qi-Long; Landoulsi, Ahmed; Ramirez-Arcos, Sandra

2017-12-01

Effective donor skin disinfection is essential in preventing bacterial contamination of blood components with skin flora bacteria like Staphylococcus epidermidis. Cell aggregates of S. epidermidis (biofilms) are found on the skin and are resistant to the commonly used donor skin disinfectants chlorhexidine-gluconate and isopropyl alcohol. It has been demonstrated that essential oils synergistically enhance the antibacterial activity of chlorhexidine-gluconate. The objective of this study was to test plant-extracted essential oils in combination with chlorhexidine-gluconate or chlorhexidine-gluconate plus isopropyl alcohol for their ability to eliminate S. epidermidis biofilms. The composition of oils extracted from Artemisia herba-alba, Lavandula multifida, Origanum marjoram, Rosmarinus officinalis, and Thymus capitatus was analyzed using gas chromatography-mass spectrometry. A rabbit model was used to assess skin irritation caused by the oils. In addition, the anti-biofilm activity of the oils used alone or in combination with chlorhexidine-gluconate or chlorhexidine-gluconate plus isopropyl alcohol was tested against S. epidermidis biofilms. Essential oil concentrations 10%, 20%, and 30% were chosen for anti-biofilm assays, because skin irritation was observed at concentrations greater than 30%. All oils except for O. marjoram had anti-biofilm activity at these three concentrations. L. multifida synergistically enhanced the anti-biofilm activity of chlorhexidine-gluconate and resulted in the highest anti-biofilm activity observed when combined with chlorhexidine-gluconate plus isopropyl alcohol. Gas chromatography-mass spectrometry revealed that the main component contributing to the activity of L. multifida oil was a natural terpene alcohol called linalool. The anti-biofilm activity of chlorhexidine-gluconate plus isopropyl alcohol can be greatly enhanced by L. multifida oil or linalool. Therefore, these components could potentially be used to improve blood donor skin disinfection. © 2017 AABB.

Effect of chlorhexidine-containing prophylactic agent on the surface characterization and frictional resistance between orthodontic brackets and archwires: an in vitro study

PubMed Central

2013-01-01

Background The purpose of this study was to assess the surface characterization and frictional resistance between stainless steel brackets and two types of orthodontic wires made of stainless steel and nickel-titanium alloys after immersion in a chlorhexidine-containing prophylactic agent. Methods Stainless steel orthodontic brackets with either stainless steel (SS) or heat-activated nickel-titanium (Ni-Ti) wires were immersed in a 0.2% chlorhexidine and an artificial saliva environment for 1.5 h. The frictional force was measured on a universal testing machine with a crosshead speed of 10 mm/min over a 5-mm of archwire. The surface morphology of bracket slots and surface roughness of archwires after immersion in chlorhexidine were also characterized using a scanning electron microscope (SEM) and an atomic force microscope (AFM), respectively. Results There was no significant difference in the frictional resistance values between SS and Ni-Ti wires immersed in either chlorhexidine or artificial saliva. The frictional resistance values for the SS and Ni-Ti wires immersed in 0.2% chlorhexidine solution were not significantly different from that inartificial saliva. No significant difference in the average surface roughness for both wires before (as-received) and after immersion in either chlorhexidine or artificial saliva was observed. Conclusions One-and-half-hour immersion in 0.2% chlorhexidine mouthrinse did not have significant influence on the archwires surface roughness or the frictional resistance between stainless steel orthodontic brackets and archwires made of SS and Ni-Ti. Based on these results, chlorhexidine-containing mouthrinses may be prescribed as non-destructive prophylactic agents on materials evaluated in the present study for orthodontic patients. PMID:24325758

The role of fluoride and chlorhexidine in preserving hardness and mineralization of enamel and cementum after gamma irradiation.

PubMed

Abdalla, Rowida; Niazy, Maha A; Jamil, Wael E; Hazzaa, Hala A; Elbatouti, Amal A

2017-05-01

The purpose of this study was to evaluate the effect of 0.05% sodium fluoride and 0.12% chlorhexidine mouthwashes on the micro-hardness of tooth enamel and cementum that was exposed to therapeutic doses of gamma radiation. Sixty extracted human teeth were divided into two groups, one was irradiated, the other was not irradiated. The two groups were further subdivided into three subgroups, which were each treated either with 0.05% sodium fluoride or with 0.12% chlorhexidine; the third subgroup served as a control. After demineralization-remineralization cycling, teeth from the irradiated groups showed a significantly lower micro-hardness when compared to those from the non-irradiated groups. Both in the irradiated and non-irradiated groups, teeth from the control subgroups showed a significantly lower micro-hardness, as compared to teeth treated with sodium fluoride and chlorhexidine. For non-irradiated enamel samples, those treated with chlorhexidine showed a significantly less micro-hardness compared to those treated with sodium fluoride. In contrast, irradiated enamel showed no significant difference in micro-hardness, whatever treatment (chlorhexidine or sodium fluoride) was applied. For cementum, treatment with chlorhexidine resulted in a significantly lower micro-hardness compared to sodium fluoride, both for the irradiated and non-irradiated groups. It is concluded that gamma irradiation with therapeutic doses typically used for head and neck carcinoma treatment has a direct effect in reducing micro-hardness of tooth enamel and cementum. Mouthwash protocols including, for example, application of 0.05% sodium fluoride or 0.12% chlorhexidine three times per day for 6 weeks, can protect enamel and cementum against the reduction in hardness and demineralization caused by gamma irradiation. Sodium fluoride offers more protection compared to chlorhexidine.

Development of resistance of mutans streptococci and Porphyromonas gingivalis to chlorhexidine digluconate and amine fluoride/stannous fluoride-containing mouthrinses, in vitro.

PubMed

Kulik, Eva M; Waltimo, Tuomas; Weiger, Roland; Schweizer, Irene; Lenkeit, Krystyna; Filipuzzi-Jenny, Elisabeth; Walter, Clemens

2015-07-01

The aim if this study was to determine the minimal inhibitory concentrations of chlorhexidine digluconate and an amine fluoride/stannous fluoride-containing mouthrinse against Porphyromonas gingivalis and mutans streptococci during an experimental long-term subinhibitory exposition. Five P. gingivalis strains and four mutans streptococci were subcultivated for 20-30 passages in subinhibitory concentrations of chlorhexidine digluconate or an amine fluoride/stannous fluoride-containing mouthrinse. Pre-passaging minimal inhibitory concentrations for chlorhexidine ranged from 0.5 to 2 mg/l for mutans streptococci and from 2 to 4 mg/l for the P. gingivalis isolates. For the amine fluoride/stannous fluoride-containing mouthrinse minimal inhibitory values from 0.125 to 0.25% for the mutans streptococci and from 0.063 to 0.125% for the P. gingivalis isolates were determined. Two- to fourfold increased minimal inhibitory concentrations against chlorhexidine were detected for two of the five P. gingivalis isolates, whereas no increase in minimal inhibitory concentrations was found for the mutans streptococci after repeated passaging through subinhibitory concentrations. Repeated exposure to subinhibitory concentrations of the amine fluoride/stannous fluoride-containing mouthrinse did not alter the minimally inhibitory concentrations of the bacterial isolates tested. Chlorhexidine and the amine fluoride/stannous fluoride-containing mouthrinse are effective inhibitory agents against the oral bacterial isolates tested. No general development of resistance against chlorhexidine or the amine fluoride/stannous fluoride-containing mouthrinse was detected. However, some strains showed potential to develop resistance against chlorhexidine after prolonged exposure. The use of chlorhexidine should be limited to short periods of time. The amine fluoride/stannous fluoride-containing mouthrinse appears to have the potential to be used on a long-term basis.

Formulation and stability of an extemporaneous 0.02% chlorhexidine digluconate ophthalmic solution.

PubMed

Lin, Shu-Chiao; Huang, Chih-Fen; Shen, Li-Jiuan; Wang, Hsueh-Ju; Lin, Chia-Yu; Wu, Fe-Lin Lin

2015-12-01

Acanthamoeba keratitis is difficult to treat because Acanthamoeba cysts are resistant to the majority of antimicrobial agents. Despite the efficacy of 0.02% chlorhexidine in treating Acanthamoeba keratitis, a lack of data in the literature regarding the formulation's stability limits its clinical use. The objective of this study was to develop an optimal extemporaneous 0.02% chlorhexidine digluconate ophthalmic formulation for patients in need. With available active pharmaceutical ingredients, 0.02% chlorhexidine digluconate sample solutions were prepared by diluting with BSS Plus Solution or acetate buffer. Influences of the buffer, type of container, and temperature under daily-open condition were assessed based on the changes of pH values and chlorhexidine concentrations of the test samples weekly. To determine the beyond-use date, the optimal samples were stored at 2-8°C or room temperature, and analyzed at time 0 and at Week 1, Week 2, Week 3, Week 4, Week 5, Week 8, Week 12, and Week 24. Despite chlorhexidine exhibiting better stability in acetate buffer than in BSS solution, its shelf-life was < 14 days when stored in a light-resistant low-density polyethylene container. The acetate-buffered 0.02% chlorhexidine digluconate solution stored in light-resistant high-density polyethylene eyedroppers did not exhibit significant changes in pH or strength at any time interval. The acetate-buffered 0.02% chlorhexidine digluconate ophthalmic solution stored in light-resistant high-density polyethylene eyedroppers demonstrated excellent stability at 2-25°C for 6 months after being sealed and for 1 month after opening. This finding will enable us to prepare 0.02% chlorhexidine digluconate ophthalmic solutions based on a doctor's prescription. Copyright © 2014. Published by Elsevier B.V.

A Randomized Controlled Trial of Chlorhexidine Vaginal and Infant Wipes to Reduce Perinatal Mortality and Morbidity

PubMed Central

Saleem, S; Rouse, DJ; McClure, EM; Reza, T; Yahya, Y; Memon, IA; Zaidi, Anita; Khan, NH; Memon, G; Soomro, N; Pasha, O; Wright, LL; Moore, J; Goldenberg, RL

2013-01-01

Background Sepsis is a leading cause of perinatal death in developing countries. Vaginal organisms acquired during labor play a significant role. Prior studies suggest that chlorhexidine wiping of the maternal vagina during labor and of the neonate may reduce peripartum infections. Methods We performed a placebo-controlled, randomized trial of chlorhexidine vaginal and neonatal wipes to reduce neonatal sepsis and mortality in three hospitals in Pakistan. The primary study outcome was a composite of neonatal sepsis or 7-day perinatal mortality. Findings From 2005 to 2008, 5,008 laboring women and their neonates were randomized to receive either chlorhexidine wipes (n = 2,505) or wipes with a saline placebo (n = 2,503). The primary outcome was similar in the chlorhexidine and control groups, (3.1% vs. 3.4%; RR 0.91, 95% CI 0.67, 1.24), as was the composite rate of neonatal sepsis or 28-day perinatal mortality, (3.8% vs. 3.9%, RR 0.96, 95% CI 0.73, 1.27). At day 7, the chlorhexidine group had a lower rate of neonatal skin infection. (3.3 vs. 8.2%, p<0.0001) With the exception of less frequent 7-day hospitalization in the chlorhexidine group, there were no significant differences in maternal outcomes between the groups. Interpretation This trial provides evidence that the use of maternal chlorhexidine vaginal wipes during labor and neonatal chlorhexidine wipes does not reduce maternal and perinatal mortality or neonatal sepsis. The finding of reduced superficial skin infections on day 7 without change in sepsis or mortality suggests that this difference, although statistically significant, may not be of major importance. Trial Registration: Clinicaltrials.gov: NCT00121394 PMID:20502294

Chlorhexidine hexametaphosphate as a wound care material coating: antimicrobial efficacy, toxicity and effect on healing.

PubMed

Barbour, Michele E; Maddocks, Sarah E; Grady, Helena J; Roper, James A; Bass, Mark D; Collins, Andrew M; Dommett, Rachel M; Saunders, Margaret

2016-08-01

In this study, chlorhexidine hexametaphosphate (CHX-HMP) is investigated as a persistent antimicrobial coating for wound care materials. CHX-HMP was used as a wound care material coating and compared with chlorhexidine digluconate materials with respect to antimicrobial efficacy, toxicity and wound closure. Antimicrobial efficacy at day 1, 3 and 7 was observed with experimental and commercial materials. CHX-HMP coated materials had less toxic effect on human placental cells than commercial chlorhexidine dressings. CHX-HMP in pluronic gel did not delay healing but reduced wound colonization by E. faecalis. CHX-HMP could become a useful component of wound care materials with sustained antimicrobial efficacy, lower toxicity than chlorhexidine digluconate materials, and reduction in wound colonization without affecting closure.

Pectin gelation with chlorhexidine: Physico-chemical studies in dilute solutions.

PubMed

Lascol, Manon; Bourgeois, Sandrine; Guillière, Florence; Hangouët, Marie; Raffin, Guy; Marote, Pedro; Lantéri, Pierre; Bordes, Claire

2016-10-05

Low methoxyl pectin is known to gel with divalent cations (e.g. Ca(2+), Zn(2+)). In this study, a new way of pectin gelation in the presence of an active pharmaceutical ingredient, chlorhexidine (CX), was highlighted. Thus chlorhexidine interactions with pectin were investigated and compared with the well-known pectin/Ca(2+) binding model. Gelation mechanisms were studied by several physico-chemical methods such as zeta potential, viscosity, size measurements and binding isotherm was determined by Proton Nuclear Magnetic Resonance Spectroscopy ((1)H NMR). The binding process exhibited similar first two steps for both divalent ions: a stoichiometric monocomplexation of the polymer followed by a dimerization step. However, stronger interactions were observed between pectin and chlorhexidine. Moreover, the dimerization step occurred under stoichiometric conditions with chlorhexidine whereas non-stoichiometric conditions were involved with calcium ions. In the case of chlorhexidine, an additional intermolecular binding occurred in a third step. Copyright © 2016 Elsevier Ltd. All rights reserved.

Treatment of oral malodour. Medium-term efficacy of mechanical and/or chemical agents: a systematic review.

PubMed

Slot, Dagmar E; De Geest, Sophie; van der Weijden, Fridus A; Quirynen, Marc

2015-04-01

What is the effect of a dentifrice (DF), a mouthwash (MW), tongue cleaning (TC), or any combination of these as adjunct to toothbrushing on intra-oral malodour and tongue coating as compared to toothbrushing alone in systemically healthy patients, when used for a minimum follow-up period of 2 weeks? The MEDLINE-PubMed, Cochrane-CENTRAL and EMBASE databases were searched up to August 2014. Measurements of Volatile Sulphur Compounds and organoleptic scores of oral malodour were selected as outcome variables. Data were extracted and a descriptive analysis was performed. Independent screening of 1054 unique papers resulted in 12 eligible clinical trials with a medium-term (≥2 weeks) duration. The majority of studies provided a significant reduction in oral malodour when evaluating products with an active ingredient (incorporated into a DF or a MW) used adjunctively to toothbrushing. The added value of tongue cleaning over a MW was evaluated in one study. Due to very limited evidence, the potential effect of a specifically formulated dentifrice, a mouthwash or a tongue scraper for treating oral malodour is, in general, unclear. For mouthwashes containing the active ingredients chlorhexidine + cetylpyridinium chloride + zinc (CHX + CPC + Zn) and zinc chloride + cetylpyridinium chloride (ZnCl + CPC) most evidence was available. The strength of a recommendation to use these products was graded to be 'weak'. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Short term comparative study of topical 2% carteolol with and without benzalkonium chloride in healthy volunteers

PubMed Central

Baudouin, C.; de Lunardo, C.

1998-01-01

AIM—A crossover, randomised double blind study was undertaken in 30 healthy volunteers, in order to compare the tolerance of 2% carteolol with and without preservative in short term use.
METHODS—Complete ophthalmic examinations were performed before and 30, 60, and 180 minutes after instillation of one drop of the solution, and after 3 days of preservative treatment. After a 5 day washout, the same examinations were done with the second drug.
RESULTS—Results showed good general tolerance for both formulations. No significant difference in subjective tolerance, corneal aesthesiometry, punctuate keratitis, Schirmer's test, intraocular pressure (IOP) decrease (about 25% in the two groups at 3 hours, 10% after 3 days of treatment), resting cardiac frequency, or blood pressure was observed. However, break up time was significantly reduced from baseline by preserved carteolol both at 3 hours (10.40 (5.9) seconds to 6.15 (3.9) seconds, p=0.001) and after 3 days (7.72 (5.5) seconds, p=0.04). Preservative free carteolol did not significantly change the break up time (baseline 9.08 (5.7) seconds; 3 hours = 7.88 (5.5) seconds, not significant; day 3 = 8.35 (5.8), non-significant).
CONCLUSIONS—These results confirm that carteolol is well tolerated, either with or without preservative. The preservative free group showed better stability of the tear film, without loss of effect on IOP. This difference, although mild in the healthy young subjects in the present study could be much more relevant in those patients treated long term, older patients, and/or those suffering from ocular surface disorders. In such instances, preservative free drugs could be of potential benefit to protect the lacrimal fluid integrity and corneoconjunctival surface.

 Keywords: glaucoma; carteolol; benzalkonium; preservatives; β blockers PMID:9536878

Corneal Injury from Presurgical Chlorhexidine Skin Preparation.

PubMed

Bever, Gregory J; Brodie, Frank L; Hwang, David G

2016-12-01

Chlorhexidine skin preparation has been shown to provide highly effective antimicrobial presurgical skin cleansing. However, there is a significant risk of ocular toxicity when it is used in periocular areas. We describe 2 cases of significant corneal damage resulting from 4% chlorhexidine gluconate preoperative skin cleanser, despite the use of protective occlusive dressing over the eyes. Because of the potential for severe corneal toxicity resulting from use of chlorhexidine, alternative agents such as 10% povidone-iodine should be considered for skin preparation near periocular areas whenever possible. If chlorhexidine gluconate must be employed near periocular areas, great care must be exercised to avoid contact with the eyes, and additional protective measures (e.g., absorbent eye pads along with tightly occlusive dressings) must be used whenever possible. Copyright © 2016 Elsevier Inc. All rights reserved.

Characterization of biocide-tolerant bacteria isolated from cheese and dairy small-medium enterprises.

PubMed

Fernández Márquez, Ma Luisa; Grande Burgos, Ma José; López Aguayo, Ma Carmen; Pérez Pulido, Rubén; Gálvez, Antonio; Lucas, Rosario

2017-04-01

A collection of 120 bacterial isolates from small medium enterprises involved in the production of cow milk and the manufacture of goat cheese were screened for sensitivity to biocides benzalkonium chloride (BC), cetrimide (CT), hexadecylpyridinium chloride (HDP), triclosan (TC), hexachlorophene (CF) and poly-(hexamethylen guanidinium) hydrochloride (PHMG). Nineteen isolates were selected according to biocide tolerance and identified by 16S rDNA sequencing as Lactococcus sp. (6) Enterococcus sp. (1), Lactobacillus sp. (4), Bacillus sp. (1) Escherichia sp. (5), Enterobacter sp. (1) and Helicobacter sp. (1). These were further characterised regarding antimicrobial resistance phenotype and genotype. Several isolates were multiply (3 or more) tolerant to biocides or resistant to antibiotics, but only two Escherichia sp. isolates and Enterobacter sp. were multiply resistant to biocides and antibiotics. Statistical analysis of biocide tolerance and antibiotic resistance revealed significant positive correlations between different biocides and between biocides and antibiotics. The biocide tolerance genes most frequently found were qacEΔ1 and qacA/B. The sulfonamide resistance gene sul1 was found in two Escherichia sp. isolates and in Enterobacter sp., all of which also carried qacEΔ1. Beta-lactam (bla CTX-M , bla PSE ) and tetracycline resistance genes [tet(A), tet(C) and tet(D)] were detected. Efflux pump genes acrB and mdfA were found in most Gram-negative isolates. Results from the study suggest that exposure to biocides can indirectly select for antibiotic resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.

21 CFR 529.400 - Chlorhexidine tablets and suspension.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Chlorhexidine tablets and suspension. 529.400... Chlorhexidine tablets and suspension. (a) Specification. Each tablet and each 28-milliliter syringe of.... 000856 in § 510.600(c) of this chapter. (c) Conditions of use—(1) Amount. Place 1 or 2 tablets deep in...

Prevention of nosocomial infection in cardiac surgery by decontamination of the nasopharynx and oropharynx with chlorhexidine gluconate: a randomized controlled trial.

PubMed

Segers, Patrique; Speekenbrink, Ron G H; Ubbink, Dirk T; van Ogtrop, Marc L; de Mol, Bas A

2006-11-22

Nosocomial infections are an important cause of morbidity and mortality after cardiac surgery. Decolonization of endogenous potential pathogenic microorganisms is important in the prevention of nosocomial infections. To determine the efficacy of perioperative decontamination of the nasopharynx and oropharynx with 0.12% chlorhexidine gluconate for reduction of nosocomial infection after cardiac surgery. A prospective, randomized, double-blind, placebo-controlled clinical trial conducted at the Onze Lieve Vrouwe Gasthuis, Amsterdam, the Netherlands, between August 1, 2003, and September 1, 2005. Of 991 patients older than 18 years undergoing elective cardiothoracic surgery during the study interval, 954 were eligible for analysis. Oropharyngeal rinse and nasal ointment containing either chlorhexidine gluconate or placebo. Incidence of nosocomial infection, in addition to the rate of Staphylococcus aureus nasal carriage and duration of hospital stay. The incidence of nosocomial infection in the chlorhexidine gluconate group and placebo group was 19.8% and 26.2%, respectively (absolute risk reduction [ARR], 6.4%; 95% confidence interval [CI], 1.1%-11.7%; P = .002). In particular, lower respiratory tract infections and deep surgical site infections were less common in the chlorhexidine gluconate group than in the placebo group (ARR, 6.5%; 95% CI, 2.3%-10.7%; P = .002; and 3.2%; 95% CI, 0.9%-5.5%; P = .002, respectively). For the prevention of 1 nosocomial infection, 16 patients needed to be treated with chlorhexidine gluconate. A significant reduction of 57.5% in S aureus nasal carriage was found in the chlorhexidine gluconate group compared with a reduction of 18.1% in the placebo group (P<.001). Total hospital stay for patients treated with chlorhexidine gluconate was 9.5 days compared with 10.3 days in the placebo group (ARR, 0.8 days; 95% CI, 0.24-1.88; P = .04). Decontamination of the nasopharynx and oropharynx with chlorhexidine gluconate appears to be an effective method to reduce nosocomial infection after cardiac surgery. clinicaltrials.gov Identifier: NCT00272675.

The conductivity measurements applied for the evaluation of controlled release of chlorhexidine from thermosensitive N-isopropylacrylamide derivative microgels.

PubMed

Musiał, Witold; Kokol, Vanja; Voncina, Bojana

2009-01-01

The aim of the work was the evaluation of the conductivity changes in aqueous environment, consisting of chlorhexidine, and N-isopropylacrylamide derivative microgel, during increasing the temperature between 25 degrees C and 42 degrees C, as a prerequisite to develop the this microgel for controlled release of chlorhexidine, when alterations in temperature are involved. Conductivity of studied systems underwent specific alterations, when temperature increased. For the system with polymer PNM I the values of conductivity were in the range 104,47 microS/cm - 134,70 microS/ cm, for temperature range 25 degrees C and 42 degrees C. In the case of PNM II - CX system, respective values reached 91,75 microS/cm - 135,95 microS/cm. The lowest conductivity values were observed when PNM III - CX mixture was studied: 96,90 microS/cm and 117,37 microS/cm. When a complex of derivatives of N-isopropylacrylamide with chlorhexidine undergoes thermal alteration, there is a potential to obtain controlled release of chlorhexidine from the polymeric bead in the range between 25 degrees C and 42 degrees C. The affinity of chlorhexidine to the polymer may be assessed in this systems applying the conductivity measurements. The solubility of chlorhexidine in the polymeric systems should be in future evaluated, to determine role of this factor in the conductivity alterations.

The use of chlorhexidine to reduce maternal and neonatal mortality and morbidity in low-resource settings

PubMed Central

McClure, Elizabeth M; Goldenberg, Robert L; Brandes, Neal; Darmstadt, Gary L; Wright, Linda L

2009-01-01

Of the 4 million neonatal deaths and 500,000 maternal deaths that occur annually worldwide, almost 99% are in developing countries and one-third are associated with infections. Implementation of proven interventions and targeted research on a select number of promising high-impact preventative and curative interventions are essential to achieve Millennium Development Goals for reduction of child and maternal mortality. Feasible, simple, low-cost interventions have the potential to significantly reduce the mortality and severe morbidity associated with infection in these settings. Studies of chlorhexidine in developing countries have focused on three primary uses: 1) intrapartum vaginal and neonatal wiping, 2) neonatal wiping alone, and 3) umbilical cord cleansing. A study of vaginal wiping and neonatal skin cleansing with chlorhexidine, conducted in Malawi in the 1990s suggested that chlorhexidine has potential to reduce neonatal infectious morbidity and mortality. A recent trial of cord cleansing conducted in Nepal also demonstrated benefit. Although studies have shown promise, widespread acceptance and implementation of chlorhexidine use has not yet occurred. This paper is derived in part from data presented at a conference on the use of chlorhexidine in developing countries and reviews the available evidence related to chlorhexidine use to reduce mortality and severe morbidity due to infections in mothers and neonates in low-resource settings. It also summarizes issues related to programmatic implementation. PMID:17399714

Establishment of a multi-species biofilm model to evaluate chlorhexidine efficacy.

PubMed

Touzel, R E; Sutton, J M; Wand, M E

2016-02-01

Chronic infections, for example, diabetic foot ulcers, have a large impact in terms of patient morbidity and mortality. These wounds are characterized by complex polymicrobial communities of bacteria, which may include a number of difficult-to-eradicate multidrug-resistant pathogens. To establish a multi-species biofilm model to test the efficacy of chlorhexidine and chlorhexidine-containing formulas in eradication of polymicrobial biofilms. A Centers for Disease Control and Prevention bioreactor was used to establish a multi-species biofilm incorporating Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis with equal numbers of each pathogen. This model was used to test the effectiveness of chlorhexidine at controlling the pre-formed biofilm. Chlorhexidine digluconate (CHD) was added to the bioreactor at a range of concentrations. K. pneumoniae and P. aeruginosa survived within multi-species biofilms, up to and including 4% CHD, whereas S. aureus was reduced to below the level of detection at 1%. Wiping the biofilm-containing coupons from the bioreactor with chlorhexidine-containing medical wipes resulted in >3 to <4log10 reduction after 24h, for all species. When the coupons were embedded in a simulated wound bed, formed in an agar plate, CHD-containing medical dressings completely eliminated S. aureus (>8log10 reduction), but had minimal effect (<3log10) against the other species tested. The study demonstrates that the effectiveness of chlorhexidine may be limited in settings where it is required to act on multi-species biofilms. This may compromise the ability of chlorhexidine to control the infection and spread of these pathogens. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Effects of chlorhexidine gluconate oral care on hospital mortality: a hospital-wide, observational cohort study.

PubMed

Deschepper, Mieke; Waegeman, Willem; Eeckloo, Kristof; Vogelaers, Dirk; Blot, Stijn

2018-05-09

Chlorhexidine oral care is widely used in critically and non-critically ill hospitalized patients to maintain oral health. We investigated the effect of chlorhexidine oral care on mortality in a general hospitalized population. In this single-center, retrospective, hospital-wide, observational cohort study we included adult hospitalized patients (2012-2014). Mortality associated with chlorhexidine oral care was assessed by logistic regression analysis. A threshold cumulative dose of 300 mg served as a dichotomic proxy for chlorhexidine exposure. We adjusted for demographics, diagnostic category, and risk of mortality expressed in four categories (minor, moderate, major, and extreme). The study cohort included 82,274 patients of which 11,133 (14%) received chlorhexidine oral care. Low-level exposure to chlorhexidine oral care (≤ 300 mg) was associated with increased risk of death [odds ratio (OR) 2.61; 95% confidence interval (CI) 2.32-2.92]. This association was stronger among patients with a lower risk of death: OR 5.50 (95% CI 4.51-6.71) with minor/moderate risk, OR 2.33 (95% CI 1.96-2.78) with a major risk, and a not significant OR 1.13 (95% CI 0.90-1.41) with an extreme risk of mortality. Similar observations were made for high-level exposure (> 300 mg). No harmful effect was observed in ventilated and non-ventilated ICU patients. Increased risk of death was observed in patients who did not receive mechanical ventilation and were not admitted to ICUs. The adjusted number of patients needed to be exposed to result in one additional fatality case was 47.1 (95% CI 45.2-49.1). These data argue against the indiscriminate widespread use of chlorhexidine oral care in hospitalized patients, in the absence of proven benefit in specific populations.

Daily chlorhexidine bathing does not increase skin toxicity after remission induction or stem cell transplantation.

PubMed

Deeren, Dries; Dewulf, Evelyne; Verfaillie, Lydie

2016-12-01

A recent multicenter study demonstrated that bathing with chlorhexidine reduces the transmission of resistant organisms and the risk of hospital-acquired bloodstream infections in ICUs. We wanted to confirm the feasibility of this strategy in a cohort of patients in a typical intensive haematology unit. Patients treated with remission induction chemotherapy, autologous or allogeneic stem cell transplantation received daily chlorhexidine bathing. To avoid deshydratation of skin, we used prophylactic application of hydrating lotion, replaced by corticosteroid cream in case of skin toxicity of chemotherapy or conditioning. We studied 15 consecutive admissions of 12 patients. Daily chlorhexidine bathing never needed to be interrupted, even though 53% of patients were treated with intravenous cytarabine. Patients were satisfied with the skin treatment and reported few unwanted effects. Daily chlorhexidine bathing was feasible in our intensive haematology unit in all patients and did not increase skin toxicity, even when treated with IV cytarabine.

Effect of ophthalmic solution components on acrylic intraocular lenses.

PubMed

Ayaki, Masahiko; Nishihara, Hitoshi; Yaguchi, Shigeo; Koide, Ryohei

2007-01-01

To investigate the effect of ophthalmic solution components on the surface of acrylic intraocular lenses (IOLs). Department of Opthalmology, Showa University School of Medicine. Measurement of the contact angles of ophthalmic solutions on 3 acrylic IOLs was performed. The solutions were diclofenac sodium (Diclod), bromfenac sodium (Bronuck), betamethasone phosphate (Rinderon), dibekacin sulfate (Panimycin), polysorbate 80 (Tween 20), benzalkonium chloride, chlorobutanol, methylparahydroxybenzoate, and propylparahydroxybenzoate. The IOLs were incubated at 35 degrees C for 2 weeks in undiluted ophthalmic solutions and in 1:10 dilutions of ophthalmic solution components. The IOLs were sectioned and observed by scanning electron microscopy. The contact angle of Diclod and Bronuck solutions was the smallest. The contact angle of Rinderon and Panimycin was similar to that of distilled water. Scanning electron microscopy examination of IOLs incubated in ophthalmic solution components showed intralenticular changes. The IOLs immersed in ophthalmic solutions did not show any change, even after extended incubation. The chemical components of ophthalmic solutions, such as surfactants and solvents, permeate acrylic IOLs, suggesting the potential for long-term adverse effects of eyedrops in pseudophakic eyes.

A comparative study of different aspects of manipulating ratio spectra applied for ternary mixtures: Derivative spectrophotometry versus wavelet transform

NASA Astrophysics Data System (ADS)

Salem, Hesham; Lotfy, Hayam M.; Hassan, Nagiba Y.; El-Zeiny, Mohamed B.; Saleh, Sarah S.

2015-01-01

This work represents a comparative study of different aspects of manipulating ratio spectra, which are: double divisor ratio spectra derivative (DR-DD), area under curve of derivative ratio (DR-AUC) and its novel approach, namely area under the curve correction method (AUCCM) applied for overlapped spectra; successive derivative of ratio spectra (SDR) and continuous wavelet transform (CWT) methods. The proposed methods represent different aspects of manipulating ratio spectra of the ternary mixture of Ofloxacin (OFX), Prednisolone acetate (PA) and Tetryzoline HCl (TZH) combined in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision.

Novel spectrophotometric methods for simultaneous determination of timolol and dorzolamide in their binary mixture.

PubMed

Lotfy, Hayam Mahmoud; Hegazy, Maha A; Rezk, Mamdouh R; Omran, Yasmin Rostom

2014-05-21

Two smart and novel spectrophotometric methods namely; absorbance subtraction (AS) and amplitude modulation (AM) were developed and validated for the determination of a binary mixture of timolol maleate (TIM) and dorzolamide hydrochloride (DOR) in presence of benzalkonium chloride without prior separation, using unified regression equation. Additionally, simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra were developed and validated for simultaneous determination of the binary mixture namely; simultaneous ratio subtraction (SRS), ratio difference (RD), ratio subtraction (RS) coupled with extended ratio subtraction (EXRS), constant multiplication method (CM) and mean centering of ratio spectra (MCR). The proposed spectrophotometric procedures do not require any separation steps. Accuracy, precision and linearity ranges of the proposed methods were determined and the specificity was assessed by analyzing synthetic mixtures of both drugs. They were applied to their pharmaceutical formulation and the results obtained were statistically compared to that of a reported spectrophotometric method. The statistical comparison showed that there is no significant difference between the proposed methods and the reported one regarding both accuracy and precision. Copyright © 2014 Elsevier B.V. All rights reserved.

A comparative study of different aspects of manipulating ratio spectra applied for ternary mixtures: derivative spectrophotometry versus wavelet transform.

PubMed

Salem, Hesham; Lotfy, Hayam M; Hassan, Nagiba Y; El-Zeiny, Mohamed B; Saleh, Sarah S

2015-01-25

This work represents a comparative study of different aspects of manipulating ratio spectra, which are: double divisor ratio spectra derivative (DR-DD), area under curve of derivative ratio (DR-AUC) and its novel approach, namely area under the curve correction method (AUCCM) applied for overlapped spectra; successive derivative of ratio spectra (SDR) and continuous wavelet transform (CWT) methods. The proposed methods represent different aspects of manipulating ratio spectra of the ternary mixture of Ofloxacin (OFX), Prednisolone acetate (PA) and Tetryzoline HCl (TZH) combined in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision. Copyright © 2014 Elsevier B.V. All rights reserved.

Bi-layered nanocomposite bandages for controlling microbial infections and overproduction of matrix metalloproteinase activity.

PubMed

Anjana, J; Mohandas, Annapoorna; Seethalakshmy, S; Suresh, Maneesha K; Menon, Riju; Biswas, Raja; Jayakumar, R

2018-04-15

Chronic diabetic wounds is characterised by increased microbial contamination and overproduction of matrix metalloproteases that would degrade the extracellular matrix. A bi-layer bandage was developed, that promotes the inhibition of microbial infections and matrix metalloprotease (MMPs) activity. Bi-layer bandage containing benzalkonium chloride loaded gelatin nanoparticles (BZK GNPs) in chitosan-Hyaluronic acid (HA) as a bottom layer and sodium alendronate containing chitosan as top layer was developed. We hypothesized that the chitosan-gelatin top layer with sodium alendronate could inhibit the MMPs activity, whereas the chitosan-HA bottom layer with BZK GNPs (240±66nm) would enable the elimination of microbes. The porosity, swelling and degradation nature of the prepared Bi-layered bandage was studied. The bottom layer could degrade within 4days whereas the top layer remained upto 7days. The antimicrobial activity of the BZK NPs loaded bandage was determined using normal and clinical strains. Gelatin zymography shows that the proteolytic activity of MMP was inhibited by the bandage. Copyright © 2017 Elsevier B.V. All rights reserved.

Overview of the [corrected] travoprost /timolol BAK-free fixed combination.

PubMed

Konstas, Anastasios G P; Quaranta, Luciano; Realini, Tony

2012-04-01

Glaucoma is the second leading cause of blindness globally, representing a significant public health concern. More than 60 million people are affected by glaucoma worldwide; as this population ages, the number is expected to increase. Glaucoma is a collection of heterogeneous diseases sharing common clinical characteristics. The goal of treatment is to prevent significant visual dysfunction through reduction of intraocular pressure (IOP). This is a review of the current literature about combination therapeutic regimens for the reduction of IOP, focusing on the risk : benefit profile of a fixed-combination therapy using travoprost and timolol. Since the debut of prostaglandin analogues in the 1990s, only modest innovation has occurred in glaucoma pharmacology. A growing body of research has established that the preservative benzalkonium chloride (BAK) might not be the benign contributor expected of excipient ingredients. Thus, BAK-free treatments were developed, with the goal of IOP reduction without furthering ocular surface disease symptoms. The BAK-free travoprost/timolol combination represents an important addition to glaucoma medication options and may fill an unmet need in this therapeutic arena.

Stress Tolerance of Methylobacterium Biofilms in Bathrooms

PubMed Central

Yano, Takehisa; Kubota, Hiromi; Hanai, Junya; Hitomi, Jun; Tokuda, Hajime

2013-01-01

A comprehensive survey of microbial flora within pink biofilms in bathrooms was performed. Pink biofilms develop relatively rapidly in bathrooms, can be difficult to remove, and are quick to recur. Bacterium-sized cells were found to be predominant in 42 pink biofilms in Japan using a scanning electron microscope. Methylobacterium strains were detected from all samples in bathrooms by an isolation method. To explain this predominance, 14 biofilm samples were analyzed by fluorescence in situ hybridization. Methylobacterium was indicated to be the major genus in all biofilms. The isolated Methylobacterium survived after contact with 1.0% cleaning agents, including benzalkonium chloride for 24 h. Their tolerance did not differ under biofilm-like conditions on fiber reinforced plastics (FRP), a general material of bath tubs, floors, and walls. Also, the strains exhibited higher tolerance to desiccation than other isolated species on FRP. Some Methylobacterium survived and exhibited potential to grow after four weeks of desiccation without any nutrients. These specific characteristics could be a cause of their predominance in bathrooms, an environment with rapid flowing water, drying, low nutrients, and occasional exposure to cleaning agents. PMID:23207727

Potential bacterial contamination of eyedrops used for tonometry.

PubMed

Palmberg, R; Gutierrez, Y S; Miller, D; Feuer, W J; Anderson, D R

1994-05-15

We compared the potential for bacterial contamination of a proparacaine hydrochloride solution preserved with benzalkonium chloride, which is used with fluorescein paper for tonometry, to that of a fluorescein-benoxinate hydrochloride combination solution preserved with chlorobutanol. We contaminated bottles of each solution with Pseudomonas aeruginosa or Staphylococcus aureus (10(7) organisms per milliliter of eyedrop solution). From the fluorescein-benoxinate hydrochloride solution, Staphylococcus organisms were cultured in declining numbers over time, with a half-life of nine seconds, and no Staphylococcus organisms were recovered after five minutes. Pseudomonas organisms disappeared from this solution within 15 seconds. Neither species was viable after 15 seconds in the proparacaine hydrochloride solution. Additionally, we cultured 12 bottles of fluorescein-benoxinate hydrochloride and 15 bottles of proparacaine hydrochloride that had been in use in the clinic for one month. No organisms were recovered from a drop dispensed from any bottle or from the tips, caps, rims, or solution from within any bottle, except that five colonies of Staphylococcus grew from the external rim of one bottle. We conclude that both solutions sterilize themselves rapidly and effectively. Either may be used safely for tonometry.

Effects of intra-articular chlorhexidine diacetate lavage on the stifle in healthy dogs.

PubMed

Anderson, M A; Payne, J T; Kreeger, J M; Wagner-Mann, C C; Schmidt, D A; Mann, F A

1993-10-01

Eight dogs were determined to be orthopedically normal on the basis of prelavage physical examination, stifle radiography, synovial fluid analysis, and force plate analysis (peak vertical force normalized for body weight, and time on the force plate). Each dog had 1 stifle randomly assigned to be lavaged with 100 ml of a commercially available 0.05% (w/v) chlorhexidine diacetate solution, and the contralateral stifle was lavaged with lactated Ringer's solution. Difference was not detected between the chlorhexidine diacetate and lactated Ringer's solution-treated joints, with regard to results of synovial fluid analysis and clinical lameness evaluations on days 4 and 8 after lavage. Chlorhexidine diacetate caused a more intense synovitis than did lactated Ringer's solution, as determined by histologic evaluation of synovial membrane specimens after necropsy on day 8; however, a difference in the intensity of toluidine blue staining of articular cartilage was not found between treatments. Chlorhexidine diacetate, as a 0.05% (w/v) solution, cannot be recommended as a joint lavage fluid until the duration of inflammatory changes in the synovial membrane are determined or until the chemical constituents of chlorhexidine diacetate causing the synovitis can be identified and removed.

Glass ionomer cements functionalised with a concentrated paste of chlorhexidine hexametaphosphate provides dose-dependent chlorhexidine release over at least 14 months.

PubMed

Bellis, Candice A; Nobbs, Angela H; O'Sullivan, Dominic J; Holder, James A; Barbour, Michele E

2016-02-01

The aim of this study was to create prototype glass ionomer cements (GICs) incorporating a concentrated paste of chlorhexidine-hexametaphosphate (CHX-HMP), and to investigate the long-term release of soluble chlorhexidine and the mechanical properties of the cements. The purpose is the design of a glass ionomer with sustained anticaries efficacy. CHX-HMP paste was prepared by mixing equimolar solutions of chlorhexidine digluconate and sodium hexametaphosphate, adjusting ionic strength, decanting and centrifuging. CHX-HMP paste was incorporated into a commercial GIC in substitution for glass powder at 0.00, 0.17, 0.34, 0.85 and 1.70% by mass CHX-HMP. Soluble chlorhexidine release into artificial saliva was observed over 436 days using absorbance at 255nm. Diametral tensile and compressive strength were measured after 7 days' setting (37°C, 100% humidity) and tensile strength after 436 days' aging in artificial saliva. 0.34% CHX-HMP GICs were tested for their ability to inhibit growth of Streptococcus mutans in vitro. GICs supplemented with CHX-HMP exhibited a sustained dose-dependent release of soluble chlorhexidine. Diametral tensile strength of new specimens was unaffected up to and including 0.85% CHX-HMP, and individual values of tensile strength were unaffected by aging, but the proportion of CHX-HMP required to adversely affect tensile strength was lower after aging, at 0.34%. Compressive strength was adversely affected by CHX-HMP at substitutions of 0.85% CHX-HMP and above. Supplementing a GIC with CHX-HMP paste resulted in a cement which released soluble chlorhexidine for over 14 months in a dose dependent manner. 0.17% and 0.34% CHX-HMP did not adversely affect strength at baseline, and 0.17% CHX-HMP did not affect strength after aging. 0.34% CHX-HMP GICs inhibited growth of S. mutans at a mean distance of 2.34mm from the specimen, whereas control (0%) GICs did not inhibit bacterial growth. Although GICs release fluoride in vivo, there is inconclusive evidence regarding any clinical anticaries effect. In this study, GICs supplemented with a paste of chlorhexidine-hexametaphosphate (CHX-HMP) exhibited a sustained release of chlorhexidine over at least 14 months, and small additions of CHX-HMP did not adversely affect strength. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modulation of drug resistance and biofilm formation of Staphylococcus aureus isolated from the oral cavity of Tunisian children.

PubMed

Zmantar, Tarek; Ben Slama, Rihab; Fdhila, Kais; Kouidhi, Bochra; Bakhrouf, Amina; Chaieb, Kamel

This study aims to investigate the antimicrobial and the anti-biofilm activities of Lactobacillus plantarum extract (LPE) against a panel of oral Staphylococcus aureus (n=9) and S. aureus ATCC 25923. The in vitro ability of LPE to modulate bacterial resistance to tetracycline, benzalchonium chloride, and chlorhexidine were tested also. The minimum inhibitory concentrations (MICs) and the minimal bactericidal concentrations of Lactobacillus plantarum extract, tetracycline, benzalchonium chloride and clohrhexidine were determined in absence and in presence of a sub-MIC doses of LPE (1/2 MIC). In addition, the LPE potential to inhibit biofilm formation was assessed by microtiter plate and atomic force microscopy assays. Statistical analysis was performed on SPSS v. 17.0 software using Friedman test and Wilcoxon signed ranks test. These tests were used to assess inter-group difference (p<0.05). Our results revealed that LPE exhibited a significant antimicrobial and anti-biofilm activities against the tested strains. A synergistic effect of LPEs and drug susceptibility was observed with a 2-8-fold reduction. LPE may be considered to have resistance-modifying activity. A more detailed investigation is necessary to determine the active compound responsible for therapeutic and disinfectant modulation. Copyright © 2016 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

Sodium chloride and potassium sorbate: a synergistic combination against Enterococcus faecalis biofilms: an in vitro study.

PubMed

van der Waal, Suzette V; Jiang, Lei-Meng; de Soet, Johannes J; van der Sluis, Lucas W M; Wesselink, Paul R; Crielaard, Wim

2012-10-01

Incomplete disinfection of the root canal system is a major cause of post-treatment disease. This study aimed to investigate the disinfecting property of organic acid salts and sodium chloride (NaCl), in a double-hurdle strategy, on Enterococcus faecalis biofilms. First of all, the high-throughput resazurin metabolism assay (RMA) was used to test a range of organic acid salts. Then, to gain more insight into the efficacy of sorbate salt solutions, 48-h E. faecalis biofilms were evaluated in colony-forming unit (CFU) assays. Chlorhexidine (CHX) and calcium hydroxide [Ca(OH)(2) ] were tested in parallel as controls. Sorbate salt produced the largest and most significant reduction of fluorescence intensity in the RMA assay. Neither NaCl nor potassium sorbate (KS) alone induced a clinically relevant reduction of CFU counts after 1 h. Surprisingly, the combination of the two in a single solution had a synergistic effect on the inactivation of E. faecalis. Potassium sorbate amplified the efficacy of NaCl. Of the salts tested, NaCl with KS eradicated E. faecalis biofilms within 1 h. This study showed that the double-hurdle strategy indeed leads to synergistic efficacy and is a possible next step in the complete disinfection of endodontic infections. © 2012 Eur J Oral Sci.

The Effect of Coconut Oil pulling on Streptococcus mutans Count in Saliva in Comparison with Chlorhexidine Mouthwash.

PubMed

Kaushik, Mamta; Reddy, Pallavi; Sharma, Roshni; Udameshi, Pooja; Mehra, Neha; Marwaha, Aditya

2016-01-01

Oil pulling is an age-old practice that has gained modern popularity in promoting oral and systemic health. The scientific verification for this practice is insufficient. Thus, this study evaluated the effect of coconut oil pulling on the count of Streptococcus mutans in saliva and to compare its efficacy with that of Chlorhexidine mouthwash: in vivo. The null hypothesis was that coconut oil pulling has no effect on the bacterial count in saliva. A randomized controlled study was planned and 60 subjects were selected. The subjects were divided into three groups, Group A: Oil pulling, Group B: Chlorhexidine, and Group C: Distilled water. Group A subjects rinsed mouth with 10 ml of coconut oil for 10 minutes. Group B subjects rinsed mouth with 5 ml Chlorhexidine mouthwash for 1 minute and Group C with 5 ml distilled water for 1 minute in the morning before brushing. Saliva samples were collected and cultured on 1st day and after 2 weeks from all subjects. Colonies were counted to compare the efficacy of coconut oil and Chlorhexidine with distilled water. Statistically significant reduction in S. mutans count was seen in both the coconut oil pulling and Chlorhexidine group. Oil pulling can be explored as a safe and effective alternative to Chlorhexidine. Edible oil-pulling therapy is natural, safe and has no side effects. Hence, it can be considered as a preventive therapy at home to maintain oral hygiene.

Comparison of antibacterial efficacy of coconut oil and chlorhexidine on Streptococcus mutans: An in vivo study.

PubMed

Peedikayil, Faizal C; Remy, Vimal; John, Seena; Chandru, T P; Sreenivasan, Prathima; Bijapur, Gufran Ahmed

2016-01-01

Streptococcus mutans is the most common organism causing dental caries. Various chemotherapeutic agents are available that help in treating the bacteria, with each having their own merits and demerits. Recent research has shown that coconut oil has anti-inflammatory and antimicrobial action. Therefore, the present was conducted to determine the antibacterial efficacy of coconut oil and to compare it with chlorhexidine. A total of fifty female children aged 8-12 years were included in the study. Twenty five children were randomly distributed to each group, i.e., the study group (coconut oil) and the control group (chlorhexidine). The participants were asked to routinely perform oil swishing with coconut oil and chlorhexidine and rinse every day in the morning after brushing for 2-3 minutes. S. mutans in saliva and plaque were determined using a chairside method, i.e., the Dentocult SM Strip Mutans test. Patients were instructed to continue oil swishing for 30 days. S. mutans . counts in plaque and saliva on day 1, day 15, and day 30 were recorded and the results were compared using Wilcoxon matched pairs signed ranks test. The results showed that there is a statistically significant decrease in S. mutans . count from coconut oil as well as chlorhexidine group from baseline to 30 days. The study also showed that in comparison of coconut oil and chlorhexidine there is no statistically significant change regarding the antibacterial efficacy. Coconut oil is as effective as chlorhexidine in the reduction of S. mutans .

In Vitro Evaluation of Mitochondrial Function and Estrogen Signaling in Cell Lines Exposed to the Antiseptic Cetylpyridinium Chloride

PubMed Central

Datta, Sandipan; He, Guochun; Tomilov, Alexey; Sahdeo, Sunil; Denison, Michael S.

2017-01-01

Background: Quaternary ammonium salts (QUATS), such as cetylpyridinium chloride (CPC) and benzalkonium chloride (BAK), are frequently used in antiseptic formulations, including toothpastes, mouthwashes, lozenges, throat and nasal sprays, and as biocides. Although in a recent ruling, the U.S. Food and Drug Administration (FDA) banned CPC from certain products and requested more data on BAK’s efficacy and safety profile, QUATS, in general, and CPC and BAK, in particular, continue to be used in personal health care, food, and pharmaceutical and cleaning industries. Objectives: We aimed to assess CPC's effects on mitochondrial toxicity and endocrine disruption in vitro. Method: Mitochondrial O2 consumption and adenosine triphosphate (ATP) synthesis rates of osteosarcoma cybrid cells were measured before and after CPC and BAK treatment. Antiestrogenic effects of the compounds were measured by a luciferase-based assay using recombinant human breast carcinoma cells (VM7Luc4E2, ERalpha-positive). Results: CPC inhibited both mitochondrial O2 consumption [half maximal inhibitory concentration (IC50): 3.8μM] and ATP synthesis (IC50: 0.9μM), and additional findings supported inhibition of mitochondrial complex 1 as the underlying mechanism for these effects. In addition, CPC showed concentration-dependent antiestrogenic activity half maximal effective concentration [(EC50): 4.5μM)]. BAK, another antimicrobial QUATS that is structurally similar to CPC, and the pesticide rotenone, a known complex 1 inhibitor, also showed mitochondrial inhibitory and antiestrogenic effects. In all three cases, there was overlap of the antiestrogenic activity with the mitochondrial inhibitory activity. Conclusions: Mitochondrial inhibition in vitro occurred at a CPC concentration that may be relevant to human exposures. The antiestrogenic activity of CPC, BAK, rotenone, and triclosan may be related to their mitochondrial inhibitory activity. Our findings support the need for additional research on the mitochondrial inhibitory and antiestrogenic effects of QUATS, including CPC and BAK. https://doi.org/10.1289/EHP1404 PMID:28885978

The Effects of a Sanquinarine Mouthrinse after Periodontal Surgery.

DTIC Science & Technology

1987-01-01

Grossman, K.: Optimal dosage of chlorhexidine digluconate in chemical plaque control when applied with an oral irrigator. J. Clin. Periodont. 8:189- 202...appear to be associated with the use of chlorhexidine , antibiotics and sanguinarine " (Lobene, 1979; Southard, et al., 1984). Plaque organisms that...patient discomfort (Levin, 1980). To minimize the influence of bacteria, chlorhexidine is used during the immediate post- operative period following

Time-Dependent Effect of Chlorhexidine Surgical Prep

DTIC Science & Technology

2011-10-15

2011 by J.A. Child Available online 15 October 2011 Keywords: Chlorhexidine Surgical site infection s u m m a r y Despite continued advances in... antisepsis is performed immediately prior to the surgical procedure. There are many different types of preoperative skin preparation solutions such...prep solution for preoperative skin antisepsis . Despite this, recent evidence suggests the superiority of an aqueous chlorhexidine scrub followed by

Antiplaque Effect of Essential Oils and 0.2% Chlorhexidine on an In Situ Model of Oral Biofilm Growth: A Randomised Clinical Trial

PubMed Central

Tomás, Inmaculada

2015-01-01

Objective To evaluate the in situ antiplaque effect after 4 days of using of 2 commercial antimicrobial agents in short term on undisturbed plaque-like biofilm. Trial Design and Participants An observer-masked, crossover randomised clinical trial on 15 oral and systemically healthy volunteers between 20–30 years who were randomly and sequentially allocated in the same group which performed 3 interventions in different randomised sequences. Intervention The participants wore an appliance in 3 different rinsing periods doing mouthwashes twice a day (1/0/1) with essential oils, 0.2% chlorhexidine or sterile water (negative control). At the end of each 4-day mouthwash period, samples were removed from the appliance. Posteriorly, after bacterial vital staining, samples were analysed using a Confocal Laser Scanning Microscope. Main Outcome Measures Bacterial vitality, thickness and covering grade by the biofilm after 4 days of applying each of the mouthwashes. Results The essential oils and the 0.2% chlorhexidine were significantly more effective than the sterile water at reducing bacterial vitality, thickness and covering grade by the biofilm. No significant differences were found between the 0.2% chlorhexidine and the essential oils at reducing the bacterial vitality (13.2% vs. 14.7%). However, the 0.2% chlorhexidine showed more reduction than the essential oils in thickness (6.5 μm vs. 10.0 μm; p<0.05) and covering grade by the biofilm (20.0% vs. 54.3%; p<0.001). Conclusion The essential oils and 0.2% chlorhexidine showed a high antiplaque effect. Although the 0.2% chlorhexidine showed better results with regard to reducing the thickness and covering grade by the biofilm, both antiseptics showed a high and similar antibacterial activity. Clinical Relevance Daily essential oils or 0.2% chlorhexidine mouthwashes are effective when reducing dental plaque formation in the short term. Although 0.2% chlorhexidine continues to be the “gold standard” in terms of antiplaque effect, essential oils could be considered a reliable alternative. Trial Registration ClinicalTrials.gov NCT02124655 PMID:25689859

Evaluation of sodium hydroxide-N-acetyl-l-cysteine and 0.7% chlorhexidine decontamination methods for recovering Mycobacterium tuberculosis from sputum samples: A comparative analysis (The Gambia Experience).

PubMed

Gitteh, Ensa; Kweku Otu, Jacob; Jobarteh, Tijan; Mendy, Francis; Faal-Jawara, Isatou Tutty; Ofori-Anyinam, Nana Boatema; Ayorinde, Abigail; Secka, Ousman; Gehre, Florian

2016-12-01

To determine the culture yield and time to detection of mycobacterial growth between samples decontaminated using 0.7% chlorhexidine and sodium hydroxide-N-acetyl-l-cysteine (NaOH-NALC) and cultured on the Löwenstein-Jensen (LJ) medium. We also aimed to determine the contamination rate between the 0.7% chlorhexidine and NaOH-NALC decontamination methods. The study was carried out on 68 sputa samples (42 smear positives and 26 smear negatives). Of these 68 samples, 46 were collected from men and 26 from women with an approximate average age of 27years. All the sputum samples were decontaminated using the standard NaOH-NALC and 0.7% chlorhexidine methods. The concentrates were cultured in parallel on LJ media in which reading of the slope for mycobacterial growth was obtained daily for the first 2weeks and then weekly until week 8. The mycobacterial recovery rate, time to detection, and contamination rate were then compared. The overall recovery rate of mycobacterial growth on samples treated with both decontamination methods inoculated on LJ media is 51.5% (35/68). Specifically, mycobacterial growth rates on samples treated with 0.7% chlorhexidine and standard NaOH-NALC on LJ media were 61.8% (42/68) and 54.4% (37/68), respectively. However, the growth of Mycobacterium tuberculosis complex was faster on samples treated with 0.7% chlorhexidine than those treated with NaOH-NALC (average, 32±5days vs. 33±5.2days, respectively). The contamination rate on samples treated with 0.7% chlorhexidine was 1.5% (1/68), whereas on those treated with NaOH-NALC, the rate was 4.4% (3/68). The 0.7% chlorhexidine decontamination method is rapid and has less contamination rate in terms of mycobacterial recovery compared with the standard NaOH-NALC method. Therefore, the 0.7% chlorhexidine decontamination method would be an ideal alternative option for decontamination of sputum samples and recovery/isolation of M. tuberculosis in resource-poor countries. Copyright © 2016.

Systematic Review and Cost Analysis Comparing Use of Chlorhexidine with Use of Iodine for Preoperative Skin Antisepsis to Prevent Surgical Site Infection

PubMed Central

Lee, Ingi; Agarwal, Rajender K.; Lee, Bruce Y.; Fishman, Neil O.; Umscheid, Craig A.

2013-01-01

Objective To compare use of chlorhexidine with use of iodine for preoperative skin antisepsis with respect to effectiveness in preventing surgical site infections (SSIs) and cost. Methods We searched the Agency for Healthcare Research and Quality website, the Cochrane Library, Medline, and EMBASE up to January 2010 for eligible studies. Included studies were systematic reviews, meta-analyses, or randomized controlled trials (RCTs) comparing preoperative skin antisepsis with chlorhexidine and with iodine and assessing for the outcomes of SSI or positive skin culture result after application. One reviewer extracted data and assessed individual study quality, quality of evidence for each outcome, and publication bias. Meta-analyses were performed using a fixed-effects model. Using results from the meta-analysis and cost data from the Hospital of the University of Pennsylvania, we developed a decision analytic cost-benefit model to compare the economic value, from the hospital perspective, of antisepsis with iodine versus antisepsis with 2 preparations of chlorhexidine (ie, 4% chlorhexidine bottle and single-use applicators of a 2% chlorhexidine gluconate [CHG] and 70% isopropyl alcohol [IPA] solution), and also performed sensitivity analyses. Results Nine RCTs with a total of 3,614 patients were included in the meta-analysis. Meta-analysis revealed that chlorhexidine antisepsis was associated with significantly fewer SSIs (adjusted risk ratio, 0.64 [95% confidence interval, [0.51–0.80]) and positive skin culture results (adjusted risk ratio, 0.44 [95% confidence interval, 0.35–0.56]) than was iodine antisepsis. In the cost-benefit model baseline scenario, switching from iodine to chlorhexidine resulted in a net cost savings of $16–$26 per surgical case and $349,904–$568,594 per year for the Hospital of the University of Pennsylvania. Sensitivity analyses showed that net cost savings persisted under most circumstances. Conclusions Preoperative skin antisepsis with chlorhexidine is more effective than preoperative skin antisepsis with iodine for preventing SSI and results in cost savings. PMID:20969449

Impact of Newborn Skin-Cleansing With Chlorhexidine on Neonatal Mortality in Southern Nepal: A Community-Based, Cluster-Randomized Trial

PubMed Central

Tielsch, James M.; Darmstadt, Gary L.; Mullany, Luke C.; Khatry, Subarna K.; Katz, Joanne; LeClerq, Steven C.; Shrestha, Shardaram; Adhikari, Ramesh

2008-01-01

OBJECTIVE Hospital-based data from Africa suggest that newborn skin-cleansing with chlorhexidine may reduce neonatal mortality. Evaluation of this intervention in the communities where most births occur in the home has not been done. Our objective was to assess the efficacy of a 1-time skin-cleansing of newborn infants with 0.25% chlorhexidine on neonatal mortality. METHODS The design was a community-based, placebo-controlled, cluster-randomized trial in Sarlahi District in southern Nepal. Newborn infants were cleansed with infant wipes that contained 0.25% chlorhexidine or placebo solution as soon as possible after delivery in the home (median: 5.8 hours). The primary outcome was all-cause mortality by 28 days. After the completion of the randomized phase, all newborns in study clusters were converted to chlorhexidine treatment for the subsequent 9 months. RESULTS A total of 17 530 live births occurred in the enrolled sectors, 8650 and 8880 in the chlorhexidine and placebo groups, respectively. Baseline characteristics were similar in the treatment groups. Intention-to-treat analysis among all live births showed no impact of the intervention on neonatal mortality. Among live-born infants who actually received their assigned treatment (98.7%), there was a nonsignificant 11% lower neonatal mortality rate among those who were treated with chlorhexidine compared with placebo. Low birth weight infants had a statistically significant 28% reduction in neonatal mortality; there was no significant difference among infants who were born weighing ≥2500 g. After conversion to active treatment in the placebo clusters, there was a 37% reduction in mortality among low birth weight infants in the placebo clusters versus no change in the chlorhexidine clusters. CONCLUSIONS Newborn skin-wiping with chlorhexidine solution once, soon after birth, reduced neonatal mortality only among low birth weight infants. Evidence from additional trials is needed to determine whether this inexpensive and simple intervention could improve survival significantly among low birth weight infants in settings where home delivery is common and hygiene practices are poor. PMID:17210728

[Antiseptic sensitivity of clinical strains of Pseudomonas aeruginosa].

PubMed

Adarchenko, A A; Krasil'nikov, A P; Sobeshchuk, O P

1989-12-01

MICs, the frequency of clinical and statistic resistance and the antiseptic activity index were studied in complex on out-of-hospital and hospital ecovars of P. aeruginosa. The forms resistant to a number of antiseptics, i.e. chloramine B, chlorhexidine, decamethoxine and dioxidine whose frequency eventually increased were shown to be widely distributed. The antiseptic sensitivity spectrum was more narrow and more heterogeneous than that of other bacteria, the heterogeneity level being dependent on the antiseptic type and bacterial ecovar. The activity of pervomur, phenol, resorcin and boric acid was higher against the clinical strains of P. aeruginosa while iodopyrin, sulfacetamide sodium and dioxidine were less active. The P. aeruginosa strains had natural resistance to cetylpyridinium chloride, rokkal, ethonium, sodium laurate and laurylsulfate and rivanol. It was recommended to assay antiseptic sensitivity of agents causing purulent inflammatory infections and to control circulation of antiseptic resistant variants of bacteria in hospitals.

The effect of a mouthrinse containing chlorine dioxide in the clinical reduction of volatile sulfur compounds.

PubMed

Soares, Leo Guimaraes; Guaitolini, Roberto Luiz; Weyne, Sergio de Carvalho; Falabella, Marcio Eduardo Vieira; Tinoco, Eduardo Muniz Barretto; da Silva, Denise Gomes

2013-07-01

This study sought to evaluate the clinical effect of a mouthrinse containing 0.3% chlorine dioxide (ClO2) in reducing oral volatile sulfur compounds (VSC). Halitosis was induced by L-cysteine in 11 volunteers, and 4 solutions were compared: a test solution containing 0.3% ClO2, 0.07% cetylpyridinium chloride (CPC), and 0.05% sodium fluoride; a placebo; a solution containing 0.05% CPC; and a control solution of 0.2% chlorhexidine gluconate (CHX). VSC levels were assessed using a Halimeter, and 6 measurements were made from baseline to 3 hours postrinse. The VSC reduction rate of the test mouthrinse was superior to the placebo and the CPC solution. There was no difference between the test solution and the CHX solution in VSC reduction rates immediately postrinse, or at 2 and 3 hours postrinse; both solutions were statistically superior to the placebo and the CPC solution.

Antimocrobial Polymer

DOEpatents

McDonald, William F.; Huang, Zhi-Heng; Wright, Stacy C.

2005-09-06

A polymeric composition having antimicrobial properties and a process for rendering the surface of a substrate antimicrobial are disclosed. The composition comprises a crosslinked chemical combination of (i) a polymer having amino group-containing side chains along a backbone forming the polymer, (ii) an antimicrobial agent selected from quaternary ammonium compounds, gentian violet compounds, substituted or unsubstituted phenols, biguanide compounds, iodine compounds, and mixtures thereof, and (iii) a crosslinking agent containing functional groups capable of reacting with the amino groups. In one embodiment, the polymer is a polyamide formed from a maleic anhydride or maleic acid ester monomer and alkylamines thereby producing a polyamide having amino substituted alkyl chains on one side of the polyamide backbone; the crosslinking agent is a phosphine having the general formula (A)3P wherein A is hydroxyalkyl; and the antimicrobial agent is chlorhexidine, dimethylchlorophenol, cetyl pyridinium chloride, gentian violet, triclosan, thymol, iodine, and mixtures thereof.

Efficacy of Concomitant Therapy with Fluoride and Chlorhexidine Varnish on Remineralization of Incipient Lesions in Young Children

PubMed Central

Tandon, Shobha; Nayak, Rashmi; Ratnanag, P Venkat; Prajapati, Deepesh; Kamath, Namitha

2016-01-01

Aim To assess the effect of combined use of chlorhexidine and fluoride varnish on the remineralization of incipient carious lesions in young children. Materials and methods Twenty caries-active children (80 lesions) were randomly divided into four groups and subjected to initial examination. Caries status was assessed visually and with the aid of DIAGNOdent. Baseline enamel biopsies were obtained. Subjects of groups I and II received fluoride and chlorhexidine varnish respectively. Group III received both fluoride and chlorhexidine varnish alternatively, for a period of 4 weeks. Group IV served as the control. At 3-month follow-up, the incipient lesions were assessed again with DIAGNOdent and enamel biopsy. Results Increased calcium, phosphate, and fluoride levels were noticed in groups I, II, III compared to group IV, at the 3-month follow-up (p < 0.001). Conclusion The combined therapy with fluoride and chlorhex-idine varnish may be considered an alternative therapy for early reversal of incipient lesions. How to cite this article Naidu S, Tandon S, Nayak R, Ratnanag PV, Prajapati D, Kamath N. Efficacy of Concomitant Therapy with Fluoride and Chlorhexidine Varnish on Remineralization of Incipient Lesions in Young Children. Int J Clin Pediatr Dent 2016;9(4):296-302. PMID:28127159

Effectiveness of intra-alveolar chlorhexidine gel in reducing dry socket following surgical extraction of lower third molars. A pilot study.

PubMed

Requena-Calla, Silvana; Funes-Rumiche, Italo

2016-04-01

Dry socket is one of the most studied complications in dentistry and several studies have sought an effective and safe method for its prevention and treatment. The aim of this study was to evaluate the effectiveness of intra-alveolar gel chlorhexidine in preventing dry socket after the surgical removal of third molars. The sample involved the treatment of 40 patients who required extraction of third molars impacted, which were randomly assigned to research groups: experimental group (chlorhexidine gel 0.12%) and control group (placebo gel). Performed the extraction was administered 1 mL of chlorhexidine gel or 1 mL of placebo gel within the socket. The removal of suture was on the fifth postoperative day in which the presence or absence of dry socket was evaluated. No relationship between the appearance of dry socket after application of chlorhexidine gel or placebo gel (X2 test, p = 0.311) was found. However, significant differences (U Mann-Whitney test, p = 0.036) in the pain presented on the fifth postoperative day were evident (VAS). The administration of intra-alveolar chlorhexidine gel 0.12% could generate a better response to postoperative pain after the removal of third molars. Third molar surgery, dry socket, chorhexidine gel.

An in vitro analysis model for investigating the staining effect of various chlorhexidine-based mouthwashes.

PubMed

Kouadio, Alain-Ayepa; Struillou, Xavier; Bories, Céline; Bouler, Jean-Michel; Badran, Zahi; Soueidan, Assem

2017-03-01

There are different mouthwashes containing chlorhexidine in different concentrations, as well as various excipients. Chlorhexidine induce stains or discoloration in teeth and mucous membranes. The aim of this work was to design a model to reproduce in vitro staining associated with the use of different mouthwashes containing chlorhexidine. We used as substrates of natural teeth and elephant ivory slices. Different incubation baths were conducted over 21 days in culture dishes at 37°C. At the beginning of experiment before incubation (D0) and after 21 days (D21) of incubation with different mouthwashes, pictures of substrates were taken in a standardized manner and an image analysis software was used to analyse and quantify the staining under the various conditions by using the 3 main colours (Red, Green, Blue, RGB). The results of this work demonstrate a very good reproducibility of the protocol, and secondly, a different expression statistically significant of the primary blue colour. We suggest that for a given concentration of chlorhexidine, the staining effects may vary depending on the excipients used. This replicable model, easy to implement over a relatively short duration, can be used for evaluation of existing mouthwashes, and to test the excipients anti discoloration proposed by manufacturers. Key words: In vitro, chlorhexidine, mouthwashes, dental stain, tooth discoloration.

An investigation of the bactericidal activity of chlorhexidine digluconateagainst multidrug-resistant hospital isolates.

PubMed

Ekizoğlu, Melike; Sağiroğlu, Meral; Kiliç, Ekrem; Hasçelik, Ayşe Gülşen

2016-04-19

Hospital infections are among the most prominent medical problems around the world. Using proper biocides in an appropriate way is critically important in overcoming this problem. Several reports have suggested that microorganisms may develop resistance or reduce their susceptibility to biocides, similar to the case with antibiotics. In this study we aimed to determine the antimicrobial activity of chlorhexidine digluconate against clinical isolates. The susceptibility of 120 hospital isolated strains of 7 bacterial genera against chlorhexidine digluconate was determined by agar dilution test, using minimum inhibitory concentration (MIC) values and the EN 1040 Basic Bactericidal Activity Test to determine the bactericidal activity. According to MIC values, Pseudomonas aeruginosa and Stenotrophomonas maltophilia were found to be less susceptible to chlorhexidine digluconate. Quantitative suspension test results showed that 4% chlorhexidine digluconate was effective against antibiotic resistant and susceptible bacteria after 5 min of contact time and can be safely used in our hospital. However, concentrations below 4% chlorhexidine digluconate caused a decrease in bactericidal activity, especially for Staphylococcus aureus and P. aeruginosa. It is crucial to use biocides at appropriate concentrations and to perform surveillance studies to trace resistance or low susceptibility patterns of S. aureus, P. aeruginosa, and other hospital isolates.

Micellar and analytical implications of a new potentiometric PVC sensor based on neutral ion-pair complexes of dodecylmethylimidazolium bromide-sodium dodecylsulfate.

PubMed

Sanan, Reshu; Mahajan, Rakesh Kumar

2013-03-15

With an aim to characterize the micellar aggregates of imidazolium based ionic liquids, a new potentiometric PVC sensor based on neutral ion-pair complexes of dodecylmethylimidazolium bromide-sodium dodecylsulfate (C12MeIm(+)DS(-)) has been developed. The electrode exhibited a linear response for the concentration range of 7.9×10(-5)-9.8×10(-3) M with a super-Nernstian slope of 92.94 mV/decade, a response time of 5 s and critical micellar concentration (cmc) of 10.09 mM for C12MeImBr. The performance of the electrode in investigating the cmc of C12MeImBr in the presence of two drugs [promazine hydrochloride (PMZ) and promethazine hydrochloride (PMT)] and three triblock copolymers (P123, L64 and F68) has been found to be satisfactory on comparison with conductivity measurements. Various micellar parameters have been evaluated for the binary mixtures of C12MeImBr with drugs and triblock copolymers using Clint's, Rubingh's, and Motomura's approach. Thus the electrode offers a simple, straightforward and relatively fast technique for the characterization of micellar aggregates of C12MeImBr, complementing existing conventional techniques. Further, the analytical importance of proposed C12MeIm(+)-ISE as end point indicator in potentiometric titrations and for direct determination of cationic surfactants [cetylpyridinium chloride (CPC), tetradecyltrimethylammonium bromide (TTAB), benzalkonium chloride (BC)] in some commercial products was judged by comparing statistically with classical two-phase titration methods. Copyright © 2013 Elsevier Inc. All rights reserved.

Incorporation of chlorhexidine diacetate in provisional cements: antimicrobial activity against Streptococcus mutans and the effect on tensile strength in vitro.

PubMed

Lewinstein, I; Zenziper, E; Block, J; Kfir, A

2012-11-01

To test the antibacterial capacities and tensile strengths of three commercially available provisional cements to which chlorhexidine diacetate was added and compare them to the same unmodified cements. Sixty cylindrical samples were prepared from either three noneugenol provisional cements or the same cements modified by the addition of chlorhexidine diacetate at 7.5% w/w, with a total of 360 samples. The cements tested included Tempbond NE, Rely X Temp NE and Freegenol. Forty-eight samples from each cement were aged in saline that was replaced twice a week for up to 96 days. Twelve of these samples were removed at either 1, 15, 30 or 96 days and assessed for antibacterial properties against Streptococcus mutans with an agar diffusion test. Twelve samples of each cement, with and without chlorhexidine diacetate, were also tested 7 days after the initial setting for their tensile strength using a diametrical tensile strength test applied with an Instron machine. The results were analysed using either one-way or three-way anova. The addition of chlorhexidine diacetate resulted in provisional cements with antibacterial properties that persisted through ageing in saline for up to 96 days. The addition of chlorhexidine did not reduce the diametrical strength of the cements. The addition of chlorhexidine diacetate to provisional cements rendered all three cements antibacterial against S. mutans and this activity was maintained even after prolonged ageing of the cements, without compromising their tensile strength at 7 days. © 2012 International Endodontic Journal.

Evaluation of chlorhexidine gluconate mouthrinse-induced staining using a digital colorimeter: an in vivo study.

PubMed

Bagis, Bora; Baltacioglu, Esra; Özcan, Mutlu; Ustaomer, Seda

2011-03-01

To investigate the persistence of staining after the use of chlorhexidine gluconate mouthrinse. Twenty-four subjects (nine women and 15 men) who underwent periodontal therapy and were prescribed the use of 0.2% chlorhexidine gluconate mouthrinse participated in this study. Color values of maxillary central incisors, canines, and first molars were recorded at baseline; 3 days; and 1, 2, and 3 weeks of twice-daily chlorhexidine gluconate use with a digital intraoral colorimeter according to the CIE L*a*b* coordinates. While color-change (Delta E) values showed significant differences (P=.020) at different time points (10.1, 8.9, 8.9, 9.4, after 3 days and 1, 2, and 3 weeks, respectively), the duration of chlorhexidine gluconate use did not significantly affect the results (P=.873) (two-way ANOVA, Tukey test). No significant difference was found among Delta L* (P=.070), Delta a* (P=.169), and Delta b* (P=.691) values at any time point (one-way ANOVA). Measurements of baseline to day 3 differences showed significantly higher Delta E values than those at other time points (P<.05), but this change remained nonsignificant after 1, 2, and 3 weeks of chlorhexidine gluconate use (P>.05) (Tukey test). The highest visible staining occurred on the first molars at all time points (83%, 79%, 79%, and 96% after 3 days and 1, 2, and 3 weeks, respectively) compared to the other teeth evaluated. The staining effect of chlorhexidine gluconate mouthrinse on natural dentition should be expected to be the highest in the first few days of use.

Comparison of antibacterial efficacy of coconut oil and chlorhexidine on Streptococcus mutans: An in vivo study

PubMed Central

Peedikayil, Faizal C.; Remy, Vimal; John, Seena; Chandru, T. P.; Sreenivasan, Prathima; Bijapur, Gufran Ahmed

2016-01-01

Aims: Streptococcus mutans is the most common organism causing dental caries. Various chemotherapeutic agents are available that help in treating the bacteria, with each having their own merits and demerits. Recent research has shown that coconut oil has anti-inflammatory and antimicrobial action. Therefore, the present was conducted to determine the antibacterial efficacy of coconut oil and to compare it with chlorhexidine. Materials and Methods: A total of fifty female children aged 8–12 years were included in the study. Twenty five children were randomly distributed to each group, i.e., the study group (coconut oil) and the control group (chlorhexidine). The participants were asked to routinely perform oil swishing with coconut oil and chlorhexidine and rinse every day in the morning after brushing for 2–3 minutes. S. mutans in saliva and plaque were determined using a chairside method, i.e., the Dentocult SM Strip Mutans test. Patients were instructed to continue oil swishing for 30 days. S. mutans. counts in plaque and saliva on day 1, day 15, and day 30 were recorded and the results were compared using Wilcoxon matched pairs signed ranks test. Results: The results showed that there is a statistically significant decrease in S. mutans. count from coconut oil as well as chlorhexidine group from baseline to 30 days. The study also showed that in comparison of coconut oil and chlorhexidine there is no statistically significant change regarding the antibacterial efficacy. Conclusion: Coconut oil is as effective as chlorhexidine in the reduction of S. mutans. PMID:27891311

Evaluation of Low-Dose Ultraviolet Light C for Reduction of Select ESKAPE Pathogens in a Canine Skin and Muscle Model.

PubMed

Dujowich, Mauricio; Case, J Brad; Ellison, Gary; Wellehan, James F X

2016-08-01

This study aimed at comparing the ability of low-dose UVC, 0.05% chlorhexidine, and combined UVC with 0.05% chlorhexidine to reduce colony-forming units (CFUs) on select ESKAPE pathogens (Staphylococcus aureus, Klebsiella pneumoniae, and Enterococcus faecium) in a canine skin and muscle model. Surgical site infections (SSIs) result in increased morbidity and cost. UVC damages DNA, rendering bacteria nonviable and does not discriminate between drug-sensitive and multi-drug-resistant organisms. Specimens were inoculated with one of three pathogens. Samples were treated with a 254 nm UVC mercury lamp or a 270 nm UVC LED light at 0.015, 0.03, or 0.04 J/cm(2) doses; 0.05% and 2% chlorhexidine were used as positive controls. To evaluate synergism, 0.05% chlorhexidine was used with 0.015 J/cm(2) of UVC. CFUs were counted and compared against the negative control. There were no significant differences in CFU counts between samples of the same tissue type treated with different light sources of the same UVC dose. UVC significantly decreased CFUs when compared against all negative controls in both skin and muscle. There was no consistently superior bactericidal UVC dose identified for individual bacteria or for tissue type. The bactericidal activity of UVC at 0.015 J/cm(2) versus 0.05% chlorhexidine was not different in muscle for any bacteria. The bactericidal activity of UVC at 0.015 J/cm(2) was superior to 0.05% chlorhexidine in skin for S. aureus and K. pneumonia, but not E. faecium. Combination of UVC and 0.05% chlorhexidine showed synergy against E. faecium when evaluated on skin. Low-dose UVC shows promise as a rapid, effective, and synergistic means of reducing bacterial burdens, which may decrease the incidence of SSIs. It should be further evaluated for use when 2% chlorhexidine would be contraindicated or impractical, such as open wounds or surgical sites.

Comparison of Battlefield-expedient Topical Antimicrobial Agents for the Prevention of Burn Wound Sepsis in a Rat Model

DTIC Science & Technology

2005-08-01

Bertek Pharmaceuticals, Morgantown WV); 5% mafenide hydrochloride solution (MHS, Sigma, St. Louis, MO), and 4% chlorhexidine digluconate solution...silver sulphadiazine 1 per cent, silver sulphadiazine 1 per cent plus chlorhexidine digluconate 0.2 per cent and mafenide acetate 8.5 per cent for...Comparison of silver sulfadiazine 1% with chlorhexidine digluconate 0.2% to silver sulfadiazine 1% alone in the prophylactic topical anti- bacterial treatment

Effect of 0.2% chlorhexidine on microbial and fungal contamination of dental unit waterlines

PubMed Central

Agahi, Raha Habib; Hashemipour, Maryam Alsadat; Kalantari, Mahsa; Ayatollah-Mosavi, Amin; Aghassi, Hossein; Nassab, Amir Hossein Gandjalikhan

2014-01-01

Background: It is known that dental unit waterline can be a source of infection. The aim of this study was to evaluate the efficacy of a mouthwash, chlorhexidine, in controlling microbial and fungal contamination of dental unit waterlines. Materials and Methods: In the present experimental study, the water in high-speed handpieces and air/water syringes of 35 dental units in a dental school was investigated microbiologically. Five of the units and one tap water served as controls; 100-200-mL water samples were collected aseptically in sterile containers in the morning after a 2-min purge. Water reservoir bottles were emptied and 50 mL of 0.2% chlorhexidine mouthwash was introduced into the tank. Then the water syringe was used to flush the waterline until the pink-colored chlorhexidine was observed to flow from the water syringe. Before the next day's session and before the students used the unit, two water samples from the water syringe and water turbine was collected. The samples were transferred to the laboratory. After 48 h at 37°C, the microbial colonies were counted. The number of these colonies was evaluated using colony forming unit CFU. Data were analyzed with Mann — Whitney U test and SPSS 13.5 statistical program. The statistical significance was defined at P ≤ 0.05. Results: All 35 units were contaminated before chlorhexidine use; no contamination was detected after adding chlorhexidine to the waterlines of the units. After week 1, 28 of the 30 treated dental unit waterlines (DUWLs) had values of CFU/mL less than 200. Conclusion: The present study showed that the use of chlorhexidine could reduce microbial counts in dental unit waterlines. PMID:25097645

Influence of newborn health messages on care-seeking practices and community health behaviors among participants in the Zambia Chlorhexidine Application Trial.

PubMed

Sivalogan, Kasthuri; Semrau, Katherine E A; Ashigbie, Paul G; Mwangi, Sheila; Herlihy, Julie M; Yeboah-Antwi, Kojo; Banda, Bowen; Grogan, Caroline; Biemba, Godfrey; Hamer, Davidson H

2018-01-01

Identifying and understanding traditional perceptions that influence newborn care practices and care-seeking behavior are crucial to developing sustainable interventions to improve neonatal health. The Zambia Chlorhexidine Application Trial (ZamCAT), a large-scale cluster randomized trial, assessed the impact of 4% chlorhexidine on neonatal mortality and omphalitis in Southern Province, Zambia. The main purpose of this post-ZamCAT qualitative study was to understand the impact of newborn care health messages on care-seeking behavior for neonates and the acceptability, knowledge, and attitudes towards chlorhexidine cord care among community members and health workers in Southern Province. Five focus group discussions and twenty-six in-depth interviews were conducted with mothers and health workers from ten health centers (5 rural and 5 peri-urban/urban). Community perceptions and local realities were identified as fundamental to care-seeking decisions and influenced individual participation in particular health-seeking behaviors. ZamCAT field monitors (data collectors) disseminated health messages at the time of recruitment at the health center and during subsequent home visits. Mothers noted that ZamCAT field monitors were effective in providing lessons and education on newborn care practices and participating mothers were able to share these messages with others in their communities. Although the study found no effect of chlorhexidine cord washes on neonatal mortality, community members had positive views towards chlorhexidine as they perceived that it reduced umbilical cord infections and was a beneficial alternative to traditional cord applications. The acceptability of health initiatives, such as chlorhexidine cord application, in community settings, is dependent on community education, understanding, and engagement. Community-based approaches, such as using community-based cadres of health workers to strengthen referrals, are an acceptable and potentially effective strategy to improve care-seeking behaviors and practices.

Effectiveness of liquid soap vs. chlorhexidine gluconate for the removal of Clostridium difficile from bare hands and gloved hands.

PubMed

Bettin, K; Clabots, C; Mathie, P; Willard, K; Gerding, D N

1994-11-01

To compare liquid soap versus 4% chlorhexidine gluconate in 4% alcohol for the decontamination of bare or gloved hands inoculated with an epidemic strain of Clostridium difficile. C difficile (6.7 log10 colony-forming units [CFU], 47% spores), was seeded onto bare or latex gloved hands of ten volunteers and allowed to dry. Half the volunteers initially washed with soap and half with chlorhexidine, followed by the other agent 1 week later. Cultures were done with Rodac plates at three sites on the hand: finger/thumbtips, the palmar surfaces of the fingers, and the palm. Statistical comparison was by paired Student's t test. On bare hands, soap and chlorhexidine did not differ in residual bacterial counts on the finger/thumbtips (log10 CFU, 2.0 and 2.1, P = NS) and fingers (log10 CFU, 2.4 and 2.5, P = NS). Counts were too high on bare palms to quantitate. On gloved hands, soap was more effective than chlorhexidine on fingers (log10 CFU 1.3 and 1.7, P < .01) and palms (log10 CFU 1.5 and 2.0, P < .01), but not finger/thumbtips (log10 CFU 1.6 with each, P = NS). Residual C difficile counts were lower on gloved hands than bare hands (P < 0.01 to < 0.0001). The two agents did not differ significantly in residual counts of C difficile on bare hands, but on gloved hands residual counts were lower following soap wash than following chlorhexidine wash. These observations support the use of either soap or chlorhexidine as a handwash for removal of C difficile, but efficacy in the prevention of C difficile transmission must be determined by prospective clinical trials.

A Comparative Analysis of Antimicrobial Property of Wine and Ozone with Calcium Hydroxide and Chlorhexidine

PubMed Central

Ebenezar, A. V. Rajesh; Anand, Nirupa; Mary, A.Vinita; Mony, Bejoy

2015-01-01

Background The antibacterial properties of wine and ozone have been established but their antibacterial efficacies against endodontic pathogens are yet to be ascertained. Aim The purpose of this study is to comparatively evaluate the antibacterial property of ozonated water, white wine (14%) and de-alcoholised white wine. Materials and Methods S.mutans and E.faecalis were subcultured and inoculated in a nutrient broth for 24 hours. The following groups were formulated: Group 1A:2% Chlorhexidine (Control group); Group 1B:White wine; Group 1C:Dealcoholised white wine; Group 1D:Ozonated water; Group 2A: Ca(OH)2 + Chlorhexidine (Control group); Group 2B: White wine + Ca(OH)2; Group 2C:De-alcoholised White wine + Ca(OH)2 + chlorhexidine; Group 2D:White wine + Ca(OH)2 + chlorhexidine and group 2E: Dealcoholised white wine + Ca(OH)2 + chlorhexidine. The samples were allowed to diffuse into the culture medium for two hours, later the S. mutans were streaked on to the blood agar medium and the E. faecalis were streaked on to the Muller Hilton agar medium and incubated for 48 hours at 370C the zone of inhibition was measured after 48 hours. Results There was no growth of microorganisms seen with ozonated water. Chlorhexidine showed large zone of inhibition compared to the other groups. White wine has better antimicrobial property than de-alcoholised white wine, but when mixed with calcium hydroxide the dealcoholised white wine has better action against the microorganisms. Conclusion Ozonated water has the best antibacterial property and the antibacterial action of Calcium hydroxide is enhanced when it is mixed with de-alcoholised white wine. PMID:26266206

Effectiveness of Intraoral Chlorhexidine Protocols in the Prevention of Ventilator-Associated Pneumonia: Meta-Analysis and Systematic Review.

PubMed

Villar, Cristina C; Pannuti, Claudio M; Nery, Danielle M; Morillo, Carlos M R; Carmona, Maria José C; Romito, Giuseppe A

2016-09-01

Ventilator-associated pneumonia (VAP) is common in critical patients and related with increased morbidity and mortality. We conducted a systematic review and meta-analysis, with intention-to-treat analysis, of randomized controlled clinical trials that assessed the effectiveness of different intraoral chlorhexidine protocols for the prevention of VAP. Search strategies were developed for the MEDLINE, EMBASE, and LILACS databases. MeSH terms were combined with Boolean operators and used to search the databases. Eligible studies were randomized controlled trials of mechanically ventilated subjects receiving oral care with chlorhexidine or standard oral care protocols consisting of or associated with the use of a placebo or no chemicals. Pooled estimates of the relative risk and corresponding 95% CIs were calculated with random effects models, and heterogeneity was assessed with the Cochran Q statistic and I(2). The 13 included studies provided data on 1,640 subjects that were randomly allocated to chlorhexidine (n = 834) or control (n = 806) treatments. A preliminary analysis revealed that oral application of chlorhexidine fails to promote a significant reduction in VAP incidence (relative risk 0.80, 95% CI 0.59-1.07, I(2) = 45%). However, subgroup analyses showed that chlorhexidine prevents VAP development when used at 2% concentration (relative risk 0.53, 95% CI 0.31-0.91, I(2) = 0%) or 4 times/d (relative risk 0.56, 95% CI 0.38-0.81, I(2) = 0%). We found that oral care with chlorhexidine is effective in reducing VAP incidence in the adult population if administered at 2% concentration or 4 times/d. Copyright © 2016 by Daedalus Enterprises.

A Randomized, Clinical Trial of Preadmission Chlorhexidine Skin Preparation for Lower Extremity Total Joint Arthroplasty.

PubMed

Kapadia, Bhaveen H; Elmallah, Randa K; Mont, Michael A

2016-12-01

Periprosthetic infections are devastating postoperative complications of total joint arthroplasty (TJA), with native skin flora commonly identified as causative organisms. We compared 2% chlorhexidine gluconate-impregnated cloths to standard-of-care antiseptic bathing in patients before TJA, to evaluate periprosthetic infection risk at 1-year follow-up. This was a prospective, randomized, controlled trial at a single institution of patients undergoing hip or knee arthroplasty. Chlorhexidine-treated patients (275 arthroplasties) applied 2% chlorhexidine gluconate-impregnated cloths the night before and morning of admission. The standard-of-care cohort (279 arthroplasties) bathed with soap and water preadmission. Patients were excluded according to the following: (1) unable to comply with study requirements, (2) pregnant, (3) <18 years, (4) medical history of immunosuppression or steroid use, (5) chronic hepatitis B/C infection, (6) had infection around joint requiring surgery, or (7) chose not to participate. A total of 539 patients (554 arthroplasties) were included in the final population. There were no significant differences in American Society of Anesthesiologists grade, cut time, risk scores, or diabetes and smoking prevalence between cohorts (P > .05). A lower periprosthetic infection rate was found in the chlorhexidine cohort (0.4%) when compared to standard-of-care cohorts (2.9%). The infection odds ratio was 8.15 (95% confidence interval = 1.01-65.6; P = .049) for the standard-of-care cohort compared to the chlorhexidine cohort. No differences in assessed risk factors were found between groups. No severe adverse events were observed. Preoperative chlorhexidine cloth use decreased the risk of periprosthetic infection. This may be an appropriate antiseptic protocol to implement for patients undergoing lower extremity TJA. Copyright © 2016 Elsevier Inc. All rights reserved.

Glass fibre-reinforced composite laced with chlorhexidine digluconate and yeast adhesion.

PubMed

Waltimo, T; Luo, G; Samaranayake, L P; Vallittu, P K

2004-02-01

The aim of this study was to lace dental glass fibre reinforced composite (FRC) prepreg with chlorhexidine digluconate and to examine the adherence of common oral fungal pathogen Candida albicans to FRC made of the prepreg. Four different test and control material groups each comprising 16 test specimens ((5.0 x 5.0 x 0.8) mm3) each were used as substrates for C. albicans adherence. A porous polymer pre-impregnated woven glass fibre prepreg was laced with solution of chlorhexidine gluconate and it was used with autopolymerized denture base polymer to fabricate FRC test specimens. Control group (Group 1) consisted of FRC test specimens stored in water. In Group 2, the test specimens were stored in 10% chlorhexidine digluconate solution for 24 h. Group 3 consisted of specimens fabricated using such fibre reinforcements which were pre-soaked in 20% chlorhexidine digluconate and dried before preparation with denture base resin, and followed by storage of the specimens in water. Group 4 was similar to Group 3 but instead of water storage the specimens were immersed in 10% chlorhexidine digluconate for 24 h. For the candidal adhesion assay the test and control specimens were incubated in standardized suspensions of four different strains of C. albicans, rinsed and prepared for light-microscopy. The mean number of adherent cells in each group was counted microscopically and analysed statistically. There were significantly (P < 0.05) more adherent C. albicans cells found in Group 1 than in the other three groups which did not differ significantly from each other. The lowest numbers of adherent cells were found in Group 3. Pretreating the porous polymer pre-impregnated glass fibre reinforcement with chlorhexidine digluconate result in reduction in the number of adherent yeast cells on the surface FRC material.

Effect of chlorhexidine and ethanol on the durability of the adhesion of the fiber post relined with resin composite to the root canal.

PubMed

Cecchin, Doglas; de Almeida, José Flávio Affonso; Gomes, Brenda P F A; Zaia, Alexandre Augusto; Ferraz, Caio Cesar Randi

2011-05-01

The aim of this study was to investigate the effects of pretreatment of gel chlorhexidine and ethanol on the bond strength and durability of the adhesion of the fiber post relined with resin composite to the root dentin. Sixty bovine incisor roots were divided into four groups: irrigation with physiologic solution (control), 5 minutes with chlorhexidine, 1 minute with ethanol, and 5 minutes with chlorhexidine followed by 1 minute with ethanol. Fiber posts relined with resin composite were cemented with RelyX ARC (3M ESPE, St Paul, MN) and a self-etching adhesive system Clearfil SE Bond (Kuraray, Kurashiki, Japan). Each group was randomly divided into three subgroups: 24 hours of water storage, 12 months of water storage, and 12 months of oil storage. All roots were sectioned transversely in the coronal, middle, and apical regions, producing 1-mm thick slices, and the push-out test was performed. Statistical analysis was performed using analysis of variance and the Tukey test for post hoc comparisons (α = 0.05). Immediate groups showed similar bond strength values with or without chlorhexidine and/or ethanol pretreatment (P > .05). A significant decrease in the bond strength in the control group was observed after 12 months of storage in water and oil (P < .05). The use of chlorhexidine- and/or ethanol-preserved bond strength in the groups stored in water and oil for 12 months (P < .05). Chlorhexidine and/or ethanol pretreatment were capable of preserving the bond strength of the fiber post relined with resin composite to root dentin for 12 months. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effect of 0.2% chlorhexidine on microbial and fungal contamination of dental unit waterlines.

PubMed

Agahi, Raha Habib; Hashemipour, Maryam Alsadat; Kalantari, Mahsa; Ayatollah-Mosavi, Amin; Aghassi, Hossein; Nassab, Amir Hossein Gandjalikhan

2014-05-01

It is known that dental unit waterline can be a source of infection. The aim of this study was to evaluate the efficacy of a mouthwash, chlorhexidine, in controlling microbial and fungal contamination of dental unit waterlines. In the present experimental study, the water in high-speed handpieces and air/water syringes of 35 dental units in a dental school was investigated microbiologically. Five of the units and one tap water served as controls; 100-200-mL water samples were collected aseptically in sterile containers in the morning after a 2-min purge. Water reservoir bottles were emptied and 50 mL of 0.2% chlorhexidine mouthwash was introduced into the tank. Then the water syringe was used to flush the waterline until the pink-colored chlorhexidine was observed to flow from the water syringe. Before the next day's session and before the students used the unit, two water samples from the water syringe and water turbine was collected. The samples were transferred to the laboratory. After 48 h at 37°C, the microbial colonies were counted. The number of these colonies was evaluated using colony forming unit CFU. Data were analyzed with Mann - Whitney U test and SPSS 13.5 statistical program. The statistical significance was defined at P ≤ 0.05. All 35 units were contaminated before chlorhexidine use; no contamination was detected after adding chlorhexidine to the waterlines of the units. After week 1, 28 of the 30 treated dental unit waterlines (DUWLs) had values of CFU/mL less than 200. The present study showed that the use of chlorhexidine could reduce microbial counts in dental unit waterlines.

Prehospital oral chlorhexidine does not reduce the rate of ventilator-associated pneumonia among critically ill trauma patients: A prospective concurrent-control study.

PubMed

Mohr, Nicholas M; Pelaez Gil, Carlos A; Harland, Karisa K; Faine, Brett; Stoltze, Andrew; Pearson, Kent; Ahmed, Azeemuddin

2015-08-01

The purpose of the study was to test the hypothesis that prehospital oral chlorhexidine administered to intubated trauma patients will decrease the Clinical Pulmonary Infection Score (CPIS) during the first 2 days of hospitalization. Prospective interventional concurrent-control study of all intubated adult trauma patients transported by air ambulance to a 711-bed Midwestern academic trauma center over a 1-year period. Patients transported by 2 university-based helicopters were treated with oral chlorhexidine after intubation, and the control group was patients transported by other air transport services. Sixty-seven patients were enrolled, of which 23 received chlorhexidine (9 patients allocated to the intervention were not treated). The change in CPIS score was no different between the intervention and control groups by intention to treat (1.06- vs 1.40-point reduction, P = .520), and no difference was observed in tracheal colonization (29.0% vs 36.7%, P = .586). No differences were observed in the rate of clinical pneumonia (8.7% vs 8.6%, P = .987) or mortality (P = .196) in the per-protocol chlorhexidine group. The prehospital administration of oral chlorhexidine does not reduce the CPIS score over the first 48 hours of admission for intubated trauma patients. Further study should explore other prehospital strategies of reducing complications of critical illness. Copyright © 2015 Elsevier Inc. All rights reserved.

Antibacterial effects of fluoride varnish compared with chlorhexidine plus fluoride in disabled children.

PubMed

Baygin, Ozgul; Tuzuner, Tamer; Kusgoz, Adem; Senel, Ahmet Can; Tanriver, Mehmet; Arslan, Ipek

2014-01-01

To evaluate the effects of fluoride varnish vs a combination of chlorhexidine-thymol varnish plus a gel containing chlorhexidine and fluoride on oral hygiene and caries prevention in disabled children. Ninety patients aged 3-17 years who were treated under general anaesthesia were randomly assigned into three groups as follows: group 1: Fluor Protector (0.1% fluoride varnish); group 2: Cervitec Plus (1% chlorhexidine- 1% thymol varnish) + Cervitec Gel (0.2% chlorhexidine-0.2% sodium fluoride); group 3: control (toothbrushing only). Mutans streptococci (MS) and lactobacilli (LB) levels, visible plaque index (VPI) and gingival bleeding index (GBI) were evaluated at four stages: T0, before general anaesthesia; T1, one month after treatment; T2, six months after treatment; T3, twelve months after treatment. The data were evaluated using Kruskal-Wallis and Mann-Whitney U-tests (P < 0.05). Groups 1 and 2 showed significantly lower scores than group 3 for all parameters at T1 and T2. No statistically significant difference was detected among any of the the groups at T3 (P > 0.05). The use of materials that include both fluoride and chlorhexidine as routine treatment of children with disability may increase the success of restorations by improving oral hygiene, reduce the need for future restorative treatments and thus the need for general anaesthesia.

[Comparison of antibacterial effects of different antiseptics after hand washing].

PubMed

Buluş, Nesrin; Kaleli, Ilknur

2004-01-01

The aim of this study was to compare 4% chlorhexidine gluconate, 7.5% povidone iodine and liquid soap, which are used as hand washing solutions for the immediate, cumulative and residual effects in bacterial growth. For this purpose, 18 volunteers washed their hands with 7.5% povidone iodine, 4% chlorhexidine gluconate and liquid soap by applying standard hygienic hand washing technique. In order to find out the bacterial amount in the hands of study group, glove liquid test was used. For the evaluation of immediate effects, samples were collected just after the washing procedure, for the residual effects samples were collected from gloved hands after 3 hours, and for the cumulative effects, samples were collected after 5 days with daily hand washings. It is found that the immediate effects of 4% chlorhexidine gluconate was superior than others, and 7.5% povidone iodine was superior to liquid soap. There was no difference between 4% chlorhexidine gluconate and 7.5% povidone iodine for residual effects. The cumulative effects were observed for 4% chlorhexidine gluconate and 7.5% povidone iodine, while there was no cumulative effect for liquid soap. According to these results, it can be suggested that 4% chlorhexidine gluconate can be used as a reliable antiseptic agent in the hospitals, especially for laboratories, intensive care units and operating rooms, owing to its favourable immediate, residual and cumulative effects.

The effect of incorporating different concentrations of chlorhexidine digluconate on the degree of conversion of an experimental adhesive resin.

PubMed

Moharam, Lamiaa-Mahmoud; Salem, Haidy-Nabil; Elgamily, Hanaa-Mahmoud

2018-04-01

The aim of this study was to evaluate the effect of chlorhexidine digluconate incorporation on the degree of conversion of an experimental adhesive resin. The experimental resin was prepared from 70 wt% bisphenol A glycerolate dimethacrylate, 30 wt% hydroxyethyl methacrylate, silanized SiO2 nanofillers, 0.5% of camphorquinone and ethyl 4-dimethylaminebenzoate (binary photo-initiator system). Five chlorhexidine digluconate concentrations (0, 0.5, 1, 2 and 4 wt%) were then incorporated into the experimental resin. Thirty Potassium Bromide pellets were prepared then divided into six groups (n=5/group), repre¬senting the tested adhesive resins (Single Bond 2, 0, 0.5, 1, 2 and 4 wt% chlohexidine-incorporated experimental adhesive resins), that were applied to the pellets without light-curing (uncured specimens). Another 30 pellets were prepared and treated with the previous materials then light-cured using LED light-curing device (cured specimens). Degree of conversion of the uncured and the cured specimens were evaluated using FTIR analysis. Adper Single Bond 2 showed the highest degree of conversion mean values followed by 0.5 wt% chlorhexidine concentration then 2 wt% followed by 4 wt% then 1 wt% concentrations, while 0 wt% concentration showed the lowest mean values. Chlorhexidine digluconate had slight significant influence on the efficiency of polymerization of the experimental adhesive resin. Key words: Chlorhexidine digluconate, different concentrations, degree of conversion, experimental adhesive resin.

Recolonization of mutans Streptococci after application of chlorhexidine gel.

PubMed

Vale, Glauber Campos; Cury, Altair Antoninha Del Bel; Arthur, Rodrigo Alex; Cury, Jaime Aparecido; Tabchoury, Cínthia Pereira Machado

2014-01-01

Streptococcus mutans is specifically suppressed by intensive treatment with chlorhexidine gel, but the time for recolonization and the effect on other oral bacteria are not totally clear. In this study, recolonization of mutans streptococci was evaluated in nine healthy adult volunteers, who were highly colonized with this microorganism. Stimulated saliva was collected before (baseline) and at 1, 7, 14, 21 and 28 days after application of 1% chlorhexidine gel on volunteers' teeth for two consecutive days. On each day, the gel was applied using disposable trays for 3 x 5 min with intervals of 5 min between each application. Saliva was plated on blood agar to determine total microorganisms (TM); on mitis salivarius agar to determine total streptococci (TS) and on mitis salivarius agar plus bacitracin to determine mutans streptococci (MS). Chlorhexidine was capable of reducing the counts of MS and the proportion of MS with regard to total microorganisms (%MS/TM) (p<0.05), but these values did not differ statistically from baseline (p>0.05) after 14 days for MS and 21 days for %MS/TM. The counts of TM and TS and the proportion of MS to total streptococci did not differ statistically from baseline (p>0.05) after chlorhexidine treatment. The results suggest that the effect of chlorhexidine gel treatment on suppression of mutans streptococci is limited to less than a month in highly colonized individuals.

The use of an oxidising mouthwash to reduce staining associated with chlorhexidine. Studies in vitro and in vivo.

PubMed

Addy, M; al-Arrayed, F; Moran, J

1991-04-01

Discolouration of the teeth, tongue and dental restorative materials associated with the use of cationic antiseptics is still the limiting factor in long-term usage of antiplaque agents such as chlorhexidine. Oxidising agents have been used successfully to remove dental stain in animals, but products and regimens have not been evaluated in humans. These pilot studies in vitro and in vivo assessed a long-established oxidising mouthwash, based on peroxyborate, for stain removal from teeth and acrylic. The laboratory studies measured chlorhexidine tea stain removal from tooth and acrylic specimens. The oxidising agent markedly reduced staining on specimens. In a short-term clinical experiment, dental staining was forced over a 2 1/2-day period by reciprocal chlorhexidine and tea rinsing. 5 rinses with the oxidising mouthwash during the next 1 1/2 days dramatically reduced staining compared with water after rinses. Additionally, a single rinse with peroxyborate following the 5 water after rinses, again considerably reduced the residual staining. Effects on tongue staining were less impressive. Both experimental models produced findings consistent with those from the animal model. The results suggest proprietary oxidising mouthwashes could have a place in the control of dental stain associated with the use of chlorhexidine. Further studies to evaluate such products in a more conventional chlorhexidine regimen are indicated.

Fracture toughness of heat cured denture base acrylic resin modified with Chlorhexidine and Fluconazole as bioactive compounds.

PubMed

Al-Haddad, Alaa; Vahid Roudsari, Reza; Satterthwaite, Julian D

2014-02-01

This study investigated the impact of incorporating Chlorhexidine and Fluconazole as bioactive compounds on the fracture toughness of conventional heat cured denture base acrylic resin material (PMMA). 30 single edge-notched (SEN) samples were prepared and divided into three groups. 10% (mass) Chlorhexidine and 10% (mass) Diflucan powder (4.5% mass Fluconazole) were added to heat cured PMMA respectively to create the two study groups. A third group of conventional heat cured PMMA was prepared as the control group. Fracture toughness (3-point bending test) was carried out for each sample and critical force (Fc) and critical stress intensity factor (KIC) values measured. Data were subject to parametric statistical analysis using one-way ANOVA and Post hoc Bonferroni test (p=0.05). Fluconazole had no significant effect on the fracture toughness of the PMMA while Chlorhexidine significantly reduced the KIC and therefore affected the fracture toughness. When considering addition of a bioactive material to PMMA acrylic, Chlorhexidine will result in reduced fracture toughness of the acrylic base while Fluconazole has no effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

Distribution and visualisation of chlorhexidine within the skin using ToF-SIMS: a potential platform for the design of more efficacious skin antiseptic formulations.

PubMed

Judd, Amy M; Scurr, David J; Heylings, Jon R; Wan, Ka-Wai; Moss, Gary P

2013-07-01

In order to increase the efficacy of a topically applied antimicrobial compound the permeation profile, localisation and mechanism of action within the skin must first be investigated. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to visualise the distribution of a conventional antimicrobial compound, chlorhexidine digluconate, within porcine skin without the need for laborious preparation, radio-labels or fluorescent tags. High mass resolution and high spatial resolution mass spectra and chemical images were achieved when analysing chlorhexidine digluconate treated cryo-sectioned porcine skin sections by ToF-SIMS. The distribution of chlorhexidine digluconate was mapped throughout the skin sections and our studies indicate that the compound appears to be localised within the stratum corneum. In parallel, tape strips taken from chlorhexidine digluconate treated porcine skin were analysed by ToF-SIMS to support the distribution profile obtained from the skin sections. ToF-SIMS can act as a powerful complementary technique to map the distribution of topically applied compounds within the skin.

The antibacterial effects of silver, titanium dioxide and silica dioxide nanoparticles compared to the dental disinfectant chlorhexidine on Streptococcus mutans using a suite of bioassays

PubMed Central

Besinis, Alexandros; De Peralta, Tracy

2014-01-01

Metal-containing nanomaterials have the potential to be used in dentistry for infection control, but little is known about their antibacterial properties. This study investigated the toxicity of silver (Ag), titanium dioxide and silica nanoparticles (NPs) against the oral pathogenic species of Streptococcus mutans, compared to the routine disinfectant, chlorhexidine. The bacteria were assessed using the minimum inhibitory concentration assay for growth, fluorescent staining for live/dead cells, and measurements of lactate. All the assays showed that Ag NPs had the strongest antibacterial activity of the NPs tested, with bacterial growth also being 25-fold lower than that in chlorhexidine. The survival rate of bacteria under the effect of 100 mg l−1 Ag NPs in the media was 2% compared to 60% with chlorhexidine, while the lactate concentration was 0.6 and 4.0 mM, respectively. Silica and titanium dioxide NPs had limited effects. Dialysis experiments showed negligible silver dissolution. Overall, Ag NPs were the best disinfectant and performed better than chlorhexidine. Improvements to the MIC assay are suggested. PMID:23092443

Chlorhexidine gluconate, its properties and applications in endodontics

PubMed Central

Mohammadi, Zahed

2008-01-01

The major objective in endodontic therapy is to disinfect the entire root canal system. This requires that the pulpal content be eliminated as sources of infection. This goal may be accomplished by mechanical instrumentation and chemical irrigation, in conjunction with medication of the root canal between treatment sessions. Microorganisms and their by-products are considered to be the major cause of pulpal and periradicular pathosis. In order to reduce or eliminate bacteria from the root canal system, various irrigants have been used during treatment. Chlorhexidine is a cationic solution which can be used during treatment. It has a wide range of antimicrobial activity. Furthermore, because of its cationic structure, chlorhexidine has a unique property named substantivity. The purpose of this paper is to review different aspects of chlorhexidine in endodontics. PMID:24265633

Reduced susceptibility to chlorhexidine disinfectant among New Delhi metallo-beta-lactamase-1 positive Enterobacteriaceae and other multidrug-resistant organisms: Report from a tertiary care hospital in Karachi, Pakistan.

PubMed

Mal, P B; Farooqi, J; Irfan, S; Hughes, M A; Khan, E

2016-01-01

We analysed susceptibility of multidrug-resistant organisms (MDROs) including New Delhi metallo-beta-lactamase-1 positive Enterobacteriaceae to chlorhexidine and compared results to their susceptible counterparts. Susceptibilities of chlorhexidine digluconate in a standard (CHX-S) preparation and two commercial disinfectants containing different CHX concentrations (2% w/v and 4% w/w) were performed. MDROs had narrower range of higher CHX-S minimum inhibitory concentrations (MICs) as compared to pan-sensitive organisms. The MIC values for commercial disinfectants products for MDROs were many folds higher (20-600 times), than CHX-S for in vitro use. Increasing antibiotic resistance among bacterial isolates can be an indirect marker of reduced susceptibility to chlorhexidine in hospital setting.

Mouth sores

MedlinePlus

... gel (Lidex), anti-inflammatory amlexanox paste (Aphthasol), or chlorhexidine gluconate (Peridex) mouthwash. Over-the-counter medicines, such as ... Aphthasol). A special type of mouthwash such as chlorhexidine gluconate (such as Peridex). Alternative Names Aphthous stomatitis; Herpes ...

Randomized controlled trial of chlorhexidine dressing and highly adhesive dressing for preventing catheter-related infections in critically ill adults.

PubMed

Timsit, Jean-François; Mimoz, Olivier; Mourvillier, Bruno; Souweine, Bertrand; Garrouste-Orgeas, Maïté; Alfandari, Serge; Plantefeve, Gaétan; Bronchard, Régis; Troche, Gilles; Gauzit, Remy; Antona, Marion; Canet, Emmanuel; Bohe, Julien; Lepape, Alain; Vesin, Aurélien; Arrault, Xavier; Schwebel, Carole; Adrie, Christophe; Zahar, Jean-Ralph; Ruckly, Stéphane; Tournegros, Caroline; Lucet, Jean-Christophe

2012-12-15

Most vascular catheter-related infections (CRIs) occur extraluminally in patients in the intensive care unit (ICU). Chlorhexidine-impregnated and strongly adherent dressings may decrease catheter colonization and CRI rates. To determine if chlorhexidine-impregnated and strongly adherent dressings decrease catheter colonization and CRI rates. In a 2:1:1 assessor-masked randomized trial in patients with vascular catheters inserted for an expected duration of 48 hours or more in 12 French ICUs, we compared chlorhexidine dressings, highly adhesive dressings, and standard dressings from May 2010 to July 2011. Coprimary endpoints were major CRI with or without catheter-related bloodstream infection (CR-BSI) with chlorhexidine versus nonchlorhexidine dressings and catheter colonization rate with highly adhesive nonchlorhexidine versus standard nonchlorhexidine dressings. Catheter-colonization, CR-BSIs, and skin reactions were secondary endpoints. A total of 1,879 patients (4,163 catheters and 34,339 catheter-days) were evaluated. With chlorhexidine dressings, the major-CRI rate was 67% lower (0.7 per 1,000 vs. 2.1 per 1,000 catheter-days; hazard ratio [HR], 0.328; 95% confidence interval [CI], 0.174-0.619; P = 0.0006) and the CR-BSI rate 60% lower (0.5 per 1,000 vs. 1.3 per 1,000 catheter-days; HR, 0.402; 95% CI, 0.186-0.868; P = 0.02) than with nonchlorhexidine dressings; decreases were noted in catheter colonization and skin colonization rates at catheter removal. The contact dermatitis rate was 1.1% with and 0.29% without chlorhexidine. Highly adhesive dressings decreased the detachment rate to 64.3% versus 71.9% (P < 0.0001) and the number of dressings per catheter to two (one to four) versus three (one to five) (P < 0.0001) but increased skin colonization (P < 0.0001) and catheter colonization (HR, 1.650; 95% CI, 1.21-2.26; P = 0.0016) without influencing CRI or CR-BSI rates. A large randomized trial demonstrated that chlorhexidine-gel-impregnated dressings decreased the CRI rate in patients in the ICU with intravascular catheters. Highly adhesive dressings decreased dressing detachment but increased skin and catheter colonization. Clinical trial registered with www.clinicaltrials.gov (NCT 01189682).

Effect of Chlorhexidine Bathing Every Other Day on Prevention of Hospital-Acquired Infections in the Surgical ICU: A Single-Center, Randomized Controlled Trial.

PubMed

Swan, Joshua T; Ashton, Carol M; Bui, Lan N; Pham, Vy P; Shirkey, Beverly A; Blackshear, Jolene E; Bersamin, Jimmy B; Pomer, Rubie May L; Johnson, Michael L; Magtoto, Audrey D; Butler, Michelle O; Tran, Shirley K; Sanchez, Leah R; Patel, Jessica G; Ochoa, Robert A; Hai, Shaikh A; Denison, Karen I; Graviss, Edward A; Wray, Nelda P

2016-10-01

To test the hypothesis that compared with daily soap and water bathing, 2% chlorhexidine gluconate bathing every other day for up to 28 days decreases the risk of hospital-acquired catheter-associated urinary tract infection, ventilator-associated pneumonia, incisional surgical site infection, and primary bloodstream infection in surgical ICU patients. This was a single-center, pragmatic, randomized trial. Patients and clinicians were aware of treatment-group assignment; investigators who determined outcomes were blinded. Twenty-four-bed surgical ICU at a quaternary academic medical center. Adults admitted to the surgical ICU from July 2012 to May 2013 with an anticipated surgical ICU stay for 48 hours or more were included. Patients were randomized to bathing with 2% chlorhexidine every other day alternating with soap and water every other day (treatment arm) or to bathing with soap and water daily (control arm). The primary endpoint was a composite outcome of catheter-associated urinary tract infection, ventilator-associated pneumonia, incisional surgical site infection, and primary bloodstream infection. Of 350 patients randomized, 24 were excluded due to prior enrollment in this trial and one withdrew consent. Therefore, 325 were analyzed (164 soap and water versus 161 chlorhexidine). Patients acquired 53 infections. Compared with soap and water bathing, chlorhexidine bathing every other day decreased the risk of acquiring infections (hazard ratio = 0.555; 95% CI, 0.309-0.997; p = 0.049). For patients bathed with soap and water versus chlorhexidine, counts of incident hospital-acquired infections were 14 versus 7 for catheter-associated urinary tract infection, 13 versus 8 for ventilator-associated pneumonia, 6 versus 3 for incisional surgical site infections, and 2 versus 0 for primary bloodstream infection; the effect was consistent across all infections. The absolute risk reduction for acquiring a hospital-acquired infection was 9.0% (95% CI, 1.5-16.4%; p = 0.019). Incidences of adverse skin occurrences were similar (18.9% soap and water vs 18.6% chlorhexidine; p = 0.95). Compared with soap and water, chlorhexidine bathing every other day decreased the risk of acquiring infections by 44.5% in surgical ICU patients.

Inhibition of de novo plaque growth by a new 0.03 % chlorhexidine mouth rinse formulation applying a non-brushing model: a randomized, double blind clinical trial.

PubMed

Mor-Reinoso, Carolina; Pascual, Andres; Nart, Jose; Quirynen, Marc

2016-09-01

The aim of this study was to investigate the plaque inhibitory effect of a new 0.03 % chlorhexidine digluconate (CHX) and 0.05 % cetylpyridinium chloride (CPC) mouthrinse formulation and to explore patients' experience and side effects after its use. This short-term, randomized, double blind, parallel, clinical trial enrolled 150 periodontally healthy patients. These volunteers were randomly allocated to one of following mouthrinse groups (n = 50/group): 0.12 % CHX + 0.05 % CPC (Perio-Aid® Treatment alcohol-free), 0.03 % CHX + 0.05 % CPC new test formulation or to the placebo group. Clinical parameters (plaque, gingival, and stain indexes) and microbiological samples were taken at baseline, before supragingival cleaning, and after 4 days of undisturbed plaque growth, rinsing twice/day with one of the mouthrinses. Plaque reduction was similar for the 0.12 % CHX (-0.52 ± 0.55) and 0.03 % CHX (-0.47 ± 0.49) groups. Both showed significant reductions in plaque accumulation compared to the placebo (p < 0.001). The new formulation had less of a negative impact on taste perception when compared to the 0.12 % CHX solution. The new CHX mouthrinse was also able to control bacterial loads and reduce some periodontopathogens. This study indicated that the new 0.03 % CHX + 0.05 % CPC formulation exerted clinical efficacy similar to that achieved by an already-marketed 0.12 % CHX + 0.05 % CPC mouthrinse, but with slightly fewer side effects. Lower CHX mouthrinse formulations could be effective in the inhibition of plaque regrowth with reduced unpleasant subjective side effects.

Decontamination of stethoscope membranes with chlorhexidine: Should it be recommended?

PubMed

Álvarez, José A; Ruíz, Susana R; Mosqueda, Juan L; León, Ximena; Arreguín, Virginia; Macías, Alejandro E; Macias, Juan H

2016-11-01

To determine differences in the recontamination of stethoscope membranes after cleaning with chlorhexidine, triclosan, or alcohol. Experimental, controlled, blinded trial to determine differences in the bacterial load on stethoscope membranes. Membranes were cultured by direct imprint after disinfection with 70% isopropyl alcohol, 1% triclosan, or 1% chlorhexidine and normal use for 4 hours. As a baseline and an immediate effect control, bacterial load of membranes without disinfection and after 1 minute of disinfection with isopropyl alcohol was determined as well. Three hundred seventy cultures of in-use stethoscopes were taken, 74 from each arm. In the baseline arm the median growth was 10 CFU (interquartile range [IQR], 32-42 CFU); meanwhile, in the isopropyl alcohol immediate-effect arm it was 0 CFU (IQR, 0-0 CFU). In the arms cultured after 4 hours, a median growth of 8 CFU (IQR, 1-28 CFU) in the isopropyl alcohol arm, 4 CFU (IQR, 0-17 CFU) in the triclosan arm, and 0 CFU (IQR, 0-1 CFU) in the chlorhexidine arm were seen. No significant differences were observed between the bacterial load of the chlorhexidine arm (after 4 hours of use) and that of the isopropyl alcohol arm (after 1 minute without use) (Z= 2.41; P > .05). Chlorhexidine can inhibit recontamination of stethoscope membranes and its use could help avoid cross-infection. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Analytical Method for the Detection of Residual Active Ingredients Found in Neutralized Suspensions of Antimicrobial Products.

PubMed

Kamel, Alaa; Tomasino, Stephen F

2017-03-01

An analytical method for determining the presence and levels of residual active ingredients found in neutralized suspensions of phenolic and quaternary ammonium salt-based antimicrobial products was developed using solid-phase extraction in combination with LC-tandem MS. A single-laboratory validation of the method was performed at three concentration levels for the quaternary ammonium compounds (also referred to as benzalkonium chlorides or BACs) and the phenols in the presence of letheen broth neutralizer at 2.5 and 2.75 μg/mL, respectively, as well as at dilutions of 1:10 and 1:100 in those concentrations. The method's lowest LODs were 0.005 μg/g for BACs and 0.006 μg/g for phenols. The average recovery of the fortified samples for both active ingredients ranged between 80 and 124%, and RSDs were generally <20%. In a related study, the effectiveness of letheen broth with and without sodium thiosulfate was evaluated as a neutralizer for sodium hypochlorite. The results showed that letheen broth without sodium thiosulfate neutralizes chlorine concentrations up to 60 ppm, and that 200 μg sodium thiosulfate are required to neutralize a 72 ppm concentrated chlorine solution in letheen broth.

A comparative study of progressive versus successive spectrophotometric resolution techniques applied for pharmaceutical ternary mixtures

NASA Astrophysics Data System (ADS)

Saleh, Sarah S.; Lotfy, Hayam M.; Hassan, Nagiba Y.; Salem, Hesham

2014-11-01

This work represents a comparative study of a novel progressive spectrophotometric resolution technique namely, amplitude center method (ACM), versus the well-established successive spectrophotometric resolution techniques namely; successive derivative subtraction (SDS); successive derivative of ratio spectra (SDR) and mean centering of ratio spectra (MCR). All the proposed spectrophotometric techniques consist of several consecutive steps utilizing ratio and/or derivative spectra. The novel amplitude center method (ACM) can be used for the determination of ternary mixtures using single divisor where the concentrations of the components are determined through progressive manipulation performed on the same ratio spectrum. Those methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the official BP methods, showing no significant difference with respect to accuracy and precision.

Clinical Development of a Cytomegalovirus DNA Vaccine: From Product Concept to Pivotal Phase 3 Trial.

PubMed

Smith, Larry R; Wloch, Mary K; Chaplin, Jennifer A; Gerber, Michele; Rolland, Alain P

2013-09-25

2013 marks a milestone year for plasmid DNA vaccine development as a first-in-class cytomegalovirus (CMV) DNA vaccine enters pivotal phase 3 testing. This vaccine consists of two plasmids expressing CMV antigens glycoprotein B (gB) and phosphoprotein 65 (pp65) formulated with a CRL1005 poloxamer and benzalkonium chloride (BAK) delivery system designed to enhance plasmid expression. The vaccine's planned initial indication under investigation is for prevention of CMV reactivation in CMV-seropositive (CMV⁺) recipients of an allogeneic hematopoietic stem cell transplant (HCT). A randomized, double-blind placebo-controlled phase 2 proof-of-concept study provided initial evidence of the safety of this product in CMV⁺ HCT recipients who underwent immune ablation conditioning regimens. This study revealed a significant reduction in viral load endpoints and increased frequencies of pp65-specific interferon-γ-producing T cells in vaccine recipients compared to placebo recipients. The results of this endpoint-defining trial provided the basis for defining the primary and secondary endpoints of a global phase 3 trial in HCT recipients. A case study is presented here describing the development history of this vaccine from product concept to initiation of the phase 3 trial.

Simultaneous determination of Fluticasone propionate and Azelastine hydrochloride in the presence of pharmaceutical dosage form additives

NASA Astrophysics Data System (ADS)

Merey, Hanan A.; El-Mosallamy, Sally S.; Hassan, Nagiba Y.; El-Zeany, Badr A.

2016-05-01

Fluticasone propionate (FLU) and Azelastine hydrochloride (AZE) are co-formulated with phenylethyl alcohol (PEA) and Benzalkonium chloride (BENZ) (as preservatives) in pharmaceutical dosage form for treatment of seasonal allergies. Different spectrophotometric methods were used for the simultaneous determination of cited drugs in the dosage form. Direct spectrophotometric method was used for determining of AZE, while Derivative of double divisor of ratio spectra (DD-RS), Ratio subtraction coupled with ratio difference method (RS-RD) and Mean centering of the ratio spectra (MCR) are used for the determination of FLU. The linearity of the proposed methods was investigated in the range of 5.00-40.00 and 5.00-80.00 μg/mL for FLU and AZE, respectively. The specificity of the developed methods was investigated by analyzing laboratory prepared mixtures containing different ratios of cited drugs in addition to PEA and their pharmaceutical dosage form. The validity of the proposed methods was assessed using the standard addition technique. The obtained results were statistically compared with those obtained by official or the reported method for FLU or AZE, respectively showing no significant difference with respect to accuracy and precision at p = 0.05.

The antimicrobial effect of benzalkonium chloride on some pathogenic microbes observed on fibers of acrylic carpet.

PubMed

Khajavi, Ramin; Sattari, Morteza; Ashjaran, Ali

2007-02-15

In the presented research, the main aim is to investigate the antibacterial effectiveness of BAC solutions on acrylic fibers used in machinery carpet. An acrylic pile carpet laid in a public place for 30 days and the existence of some microbes were investigated on it. The antimicrobial effect of different BAC solutions for identified microbes was studied in vitro. The acrylic fibers were treated with the same different solutions of BAC as before and the antibacterial effectiveness was assessed by the zone of inhibition method in different times. Two pieces of carpet untreated and treated with BAC solution sewed together and laid for one week in the public place and the amounts of bacterial growth determined by colony count method and the results compared. Finally some mechanical properties of treated acrylic fibers measured after 30 days and compared with untreated one. The results showed the presence of some pathogenic microbes on the laid carpet such as Escherichia coli and Staphylococcus aureus. The inhalation time for treated acrylic fibers improved. The amount of colony growth on treated carpet reduced considerably and besides the mechanical tests results showed no significant deterioration effect of studied properties in comparing with untreated yarn.

Susceptibility of 169 USA300 methicillin-resistant Staphylococcus aureus isolates to two copper-based biocides, CuAL42 and CuWB50.

PubMed

Luna, Vicki Ann; Hall, Tony J; King, Debbie S; Cannons, Andrew C

2010-05-01

To test the activity of two copper-based biocides, CuAL42 and CuWB50, and benzalkonium chloride against 169 isolates of methicillin-resistant Staphylococcus aureus (MRSA) pulsotype USA300, a virulent, multiply resistant, widespread clone in the USA. Tests including MIC, MBC and time-kill studies were performed multiple times. The MIC range, MIC(50) and MIC(90) (0.59-18.75, 4.69 and 4.69 ppm, respectively) and the MBC range, MBC(50) and MBC(90) (1.17-18.75, 4.69 and 9.38 ppm, respectively) for CuAL42 were identical with those obtained with CuWB50, except that the MBC range for CuWB50 was wider (0.59-37.5 ppm). In time-kill studies, a 6 log(10) reduction of cfu was achieved within 1 h (150 ppm) and 0.5 h (300 ppm) for CuAL42, and 1.5 h (150 ppm) and 0.75 h (300 ppm) for CuWB50. Both copper-based biocides can effectively kill USA300 MRSA and may facilitate the eradication of the organism from healthcare settings.

Inactivation kinetics of various chemical disinfectants on Aeromonas hydrophila planktonic cells and biofilms.

PubMed

Jahid, Iqbal Kabir; Ha, Sang-Do

2014-05-01

The present article focuses on the inactivation kinetics of various disinfectants including ethanol, sodium hypochlorite, hydrogen peroxide, peracetic acid, and benzalkonium chloride against Aeromonas hydrophila biofilms and planktonic cells. Efficacy was determined by viable plate count and compared using a modified Weibull model. The removal of the biofilms matrix was determined by the crystal violet assay and was confirmed by field-emission scanning electron microscope. The results revealed that all the experimental data and calculated Weibull α (scale) and β (shape) parameters had a good fit, as the R(2) values were between 0.88 and 0.99. Biofilms are more resistant to disinfectants than planktonic cells. Ethanol (70%) was the most effective in killing cells in the biofilms and significantly reduced (p<0.05) the biofilms matrix. The Weibull parameter b-value correlated (R(2)=0.6835) with the biofilms matrix removal. The present findings deduce that the Weibull model is suitable to determine biofilms matrix reduction as well as the effectiveness of chemical disinfectants on biofilms. The study showed that the Weibull model could successfully be used on food and food contact surfaces to determine the exact contact time for killing biofilms-forming foodborne pathogens.

Chlorhexidine mouthrinse as an adjunctive treatment for gingival health.

PubMed

James, Patrice; Worthington, Helen V; Parnell, Carmel; Harding, Mairead; Lamont, Thomas; Cheung, Andrea; Whelton, Helen; Riley, Philip

2017-03-31

Dental plaque associated gingivitis is a reversible inflammatory condition caused by accumulation and persistence of microbial biofilms (dental plaque) on the teeth. It is characterised by redness and swelling of the gingivae (gums) and a tendency for the gingivae to bleed easily. In susceptible individuals, gingivitis may lead to periodontitis and loss of the soft tissue and bony support for the tooth. It is thought that chlorhexidine mouthrinse may reduce the build-up of plaque thereby reducing gingivitis. To assess the effectiveness of chlorhexidine mouthrinse used as an adjunct to mechanical oral hygiene procedures for the control of gingivitis and plaque compared to mechanical oral hygiene procedures alone or mechanical oral hygiene procedures plus placebo/control mouthrinse. Mechanical oral hygiene procedures were toothbrushing with/without the use of dental floss or interdental cleaning aids and could include professional tooth cleaning/periodontal treatment.To determine whether the effect of chlorhexidine mouthrinse is influenced by chlorhexidine concentration, or frequency of rinsing (once/day versus twice/day).To report and describe any adverse effects associated with chlorhexidine mouthrinse use from included trials. Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 28 September 2016); the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 8) in the Cochrane Library (searched 28 September 2016); MEDLINE Ovid (1946 to 28 September 2016); Embase Ovid (1980 to 28 September 2016); and CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; 1937 to 28 September 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. We included randomised controlled trials assessing the effects of chlorhexidine mouthrinse used as an adjunct to mechanical oral hygiene procedures for at least 4 weeks on gingivitis in children and adults. Mechanical oral hygiene procedures were toothbrushing with/without use of dental floss or interdental cleaning aids and could include professional tooth cleaning/periodontal treatment. We included trials where participants had gingivitis or periodontitis, where participants were healthy and where some or all participants had medical conditions or special care needs. Two review authors independently screened the search results extracted data and assessed the risk of bias of the included studies. We attempted to contact study authors for missing data or clarification where feasible. For continuous outcomes, we used means and standard deviations to obtain the mean difference (MD) and 95% confidence interval (CI). We combined MDs where studies used the same scale and standardised mean differences (SMDs) where studies used different scales. For dichotomous outcomes, we reported risk ratios (RR) and 95% CIs. Due to anticipated heterogeneity we used random-effects models for all meta-analyses. We included 51 studies that analysed a total of 5345 participants. One study was assessed as being at unclear risk of bias, with the remaining 50 being at high risk of bias, however, this did not affect the quality assessments for gingivitis and plaque as we believe that further research is very unlikely to change our confidence in the estimate of effect. Gingivitis After 4 to 6 weeks of use, chlorhexidine mouthrinse reduced gingivitis (Gingival Index (GI) 0 to 3 scale) by 0.21 (95% CI 0.11 to 0.31) compared to placebo, control or no mouthrinse (10 trials, 805 participants with mild gingival inflammation (mean score 1 on the GI scale) analysed, high-quality evidence). A similar effect size was found for reducing gingivitis at 6 months. There were insufficient data to determine the reduction in gingivitis associated with chlorhexidine mouthrinse use in individuals with mean GI scores of 1.1 to 3 (moderate or severe levels of gingival inflammation). Plaque Plaque was measured by different indices and the SMD at 4 to 6 weeks was 1.45 (95% CI 1.00 to 1.90) standard deviations lower in the chlorhexidine group (12 trials, 950 participants analysed, high-quality evidence), indicating a large reduction in plaque. A similar large reduction was found for chlorhexidine mouthrinse use at 6 months. Extrinsic tooth staining There was a large increase in extrinsic tooth staining in participants using chlorhexidine mouthrinse at 4 to 6 weeks. The SMD was 1.07 (95% CI 0.80 to 1.34) standard deviations higher (eight trials, 415 participants analysed, moderate-quality evidence) in the chlorhexidine mouthrinse group. There was also a large increase in extrinsic tooth staining in participants using chlorhexidine mouthrinse at 7 to 12 weeks and 6 months. Calculus Results for the effect of chlorhexidine mouthrinse on calculus formation were inconclusive. Effect of concentration and frequency of rinsing There were insufficient data to determine whether there was a difference in effect for either chlorhexidine concentration or frequency of rinsing. Other adverse effects The adverse effects most commonly reported in the included studies were taste disturbance/alteration (reported in 11 studies), effects on the oral mucosa including soreness, irritation, mild desquamation and mucosal ulceration/erosions (reported in 13 studies) and a general burning sensation or a burning tongue or both (reported in nine studies). There is high-quality evidence from studies that reported the Löe and Silness Gingival Index of a reduction in gingivitis in individuals with mild gingival inflammation on average (mean score of 1 on the 0 to 3 GI scale) that was not considered to be clinically relevant. There is high-quality evidence of a large reduction in dental plaque with chlorhexidine mouthrinse used as an adjunct to mechanical oral hygiene procedures for 4 to 6 weeks and 6 months. There is no evidence that one concentration of chlorhexidine rinse is more effective than another. There is insufficient evidence to determine the reduction in gingivitis associated with chlorhexidine mouthrinse use in individuals with mean GI scores of 1.1 to 3 indicating moderate or severe levels of gingival inflammation. Rinsing with chlorhexidine mouthrinse for 4 weeks or longer causes extrinsic tooth staining. In addition, other adverse effects such as calculus build up, transient taste disturbance and effects on the oral mucosa were reported in the included studies.

The effect of passive ultrasonic activation of 2% chlorhexidine or 5.25% sodium hypochlorite irrigant on residual antimicrobial activity in root canals.

PubMed

Weber, Carol Diener; McClanahan, Scott B; Miller, Glenn A; Diener-West, Marie; Johnson, James D

2003-09-01

Ninety-four single-canal roots were prepared using the step-down technique. Forty-two canals were irrigated with 2% chlorhexidine, 42 canals with 5.25% sodium hypochlorite (NaOCl), and 10 control canals with phosphate-buffered saline (PBS). The chlorhexidine and NaOCl groups were each then equally divided into a final irrigation group and a 1-min passive ultrasonic irrigation group. Canals were enlarged with a Parapost drill. The apical 3-5 mm was covered with nail polish. Canals were rinsed with PBS, dried, refilled with PBS, and stored. At 6 h, 20 microl of fluid was pipetted from each canal and placed into wells on agar plates, which were inoculated with Streptococcus sanguinis. The plates were incubated, and zones of inhibition were measured. Sampling was repeated at 24, 48, 72, 96, 120, 144, and 168 h. Residual antimicrobial activity with 2% chlorhexidine was statistically significantly superior to 5.25% NaOCl with irrigation alone and with final passive ultrasonic activation (p < 0.001). Chlorhexidine experimental groups demonstrated residual antimicrobial activity for as long as 168 h.

A prospective clinical evaluation of the effects of chlorhexidine, warm saline mouth washes and microbial growth on intraoral sutures.

PubMed

Fomete, B; Saheeb, B D; Obiadazie, A C

2015-06-01

Post operative care of sutured wound is important after surgery. Sutured wounds within the oral cavity are kept clean through frequent rinses with either normal saline, chlorhexidine mouth rinses, hydrogen peroxide diluted with saline, or fresh tap water. The patients were randomised into 3 groups (A, B and C). The container used had 34 chlorhexidine, 34 warm saline and 32 warm water mouth rinses. The latter served as control. All selected patients had scaling and polishing done preoperatively when needed. All participants in each group did not receive antibiotics but received analgesics (paracetamol 1 g 8 h for 5 days,). There were 49 females and 51 males, in the age range between 18 and 50 years. Microorganisms were found to grow on sutures with streptococcus viridians predominating followed by staphylococcus epidermides. The effects of chlorhexidine, warm saline and warm tap water mouth washes were not statistically significant. Chlorhexidine, warm salt water and warm tap water averagely produced the same number of colony forming units of bacteria, which shows that the three different mouth washes are equally effective as post-operative mouth rinses after oral surgery.

21 CFR 216.24 - Drug products withdrawn or removed from the market for reasons of safety or effectiveness.

Code of Federal Regulations, 2011 CFR

2011-04-01

...: All oral gel drug products containing carbetapentane citrate. Casein, iodinated: All drug products containing iodinated casein. Chlorhexidine gluconate: All tinctures of chlorhexidine gluconate formulated for...

An unexpected cause of an acute hypersensitivity reaction during recovery from anaesthesia.

PubMed

Thong, C L; Lambros, M; Stewart, M G; Kam, P C A

2005-08-01

Acute hypersensitivity reactions to chlorhexidine in the operating room are probably more likely to occur during the early phases of anaesthesia because chlorhexidine is often used for cleaning the surgical field or during placement of indwelling catheters. We report a case of an acute hypersensitivity reaction that occurred in the post anaesthetic care unit. Subsequent skin testing suggested sensitivity to chlorhexidine, which had been applied over the vaginal mucosa at the end of surgery. Relevant issues in the investigation of acute hypersensitivity reactions in the post anaesthetic period are discussed.

Developmental neurotoxicity of different pesticides in PC-12 cells in vitro.

PubMed

Christen, Verena; Rusconi, Manuel; Crettaz, Pierre; Fent, Karl

2017-06-15

The detection of developmental neurotoxicity (DNT) of chemicals has high relevance for protection of human health. However, DNT of many pesticides is only little known. Furthermore, validated in vitro systems for assessment of DNT are not well established. Here we employed the rat phaeochromocytoma cell line PC-12 to evaluate DNT of 18 frequently used pesticides of different classes, including neonicotinoids, pyrethroids, organophosphates, organochlorines, as well as quaternary ammonium compounds, the organic compound used in pesticides, piperonyl butoxide, as well as the insect repellent diethyltoluamide (DEET). We determined the outgrowth of neurites in PC-12 cells co-treated with nerve growth factor and different concentrations of biocides for 5days. Furthermore, we determined transcriptional alterations of selected genes that may be associated with DNT, such as camk2α and camk2β, gap-43, neurofilament-h, tubulin-α and tubulin-β. Strong and dose- dependent inhibition of neurite outgrowth was induced by azamethiphos and chlorpyrifos, and dieldrin and heptachlor, which was correlated with up-regulation of gap-43. No or only weak effects on neurite outgrowth and transcriptional alterations occurred for neonicotinoids acetamiprid, clothianidin, imidacloprid and thiamethoxam, the pyrethroids λ-cyhalothrin, cyfluthrin, deltamethrin, and permethrin, the biocidal disinfectants C12-C14-alkyl(ethylbenzyl)dimethylammonium (BAC), benzalkonium chloride and barquat (dimethyl benzyl ammonium chloride), and piperonyl butoxide and DEET. Our study confirms potential developmental neurotoxicity of some pesticides and provides first evidence that azamethiphos has the potential to act as a developmental neurotoxic compound. We also demonstrate that inhibition of neurite outgrowth and transcriptional alterations of gap-43 expression correlate, which suggests the employment of gap-43 expression as a biomarker for detection and initial evaluation of potential DNT of chemicals. Copyright © 2017 Elsevier Inc. All rights reserved.

Identification of alkyl dimethylbenzylammonium surfactants in water samples by solid-phase extraction followed by ion trap LC/MS and LC/MS/MS

USGS Publications Warehouse

Ferrer, I.; Furlong, E.T.

2001-01-01

A novel methodology was developed for the determination of alkyl (C12, C14, and C16) dimethylbenzylammonium chloride (benzalkonium chloride or BAC, Chemical Abstract Service number: 8001-54-5) in water samples. This method is based on solid-phase extraction (SPE) using polymeric cartridges, followed by high-performance liquid chromatography/ion trap mass spectrometry (LC/MS) and tandem mass spectrometry(MS/MS) detection, equipped with an electrospray interface in positive ion mode. Chromatographic separation was achieved for three BAC homologues by using a C18 column and a gradient of acetonitrile/10 millimolar aqueous ammonium formate. Total method recoveries were higher than 71% in different water matrices. The main ions observed by LC/MS were at mass-to-charge ratios (m/z) of 304, 332, and 360, which correspond to the molecular ions of the C12, C14, and C16 alkyl BAC, respectively. The unequivocal structural identification of these compounds in water samples was performed by LC/MS/MS after isolation and subsequent fragmentation of each molecular ion. The main fragmentation observed for the three different homologues corresponded to the loss of the toluyl group in the chemical structure, which leads to the fragment ions at m/z 212, 240, and 268 and a tropylium ion, characteristic of all homologues, at m/z 91. Detection limits for the methodology developed in this work were in the low nanogram-per-liter range. Concentration levels of BAC - ranging from 1.2 to 36.6 micrograms per liter - were found in surface-water samples collected downstream from different wastewater-treatment discharges, thus indicating its input and persistence through the wastewater-treatment process.

Evaluation of Different Methods for Removing Oral Biofilm in Patients Admitted to the Intensive Care Unit

PubMed Central

Oliveira, Maria Sonia; Borges, Alvaro Henrique; Mattos, Fernanda Zanol; Semenoff, Tereza Aparecida Della Vedove; Segundo, Alex Semenoff; Tonetto, Mateus Rodrigues; Bandeca, Matheus Coêlho; Porto, Alessandra Nogueira

2014-01-01

Background: The present study aimed to evaluate the different methods for removing oral biofilm in combination with 0.12% chlorhexidine, in patients admitted to the intensive care unit (ICU) of the General University Hospital. Materials and Methods: Initially, the patients were included in the study and underwent periodontal evaluation by means of the visible plaque index (VPI) and gingival bleeding index (GBI). The removal of visible biofilm, by a professional, was carried out using a toothbrush and dental floss, followed by the application of a 0.12% chlorhexidine solution. The patients were included in this randomized and controlled study into four groups (total n = 48), as follows: Chlorhexidine and gauze 12/12 h; chlorhexidine and gauze 24/24 h; chlorhexidine and brushing 12/12 h; chlorhexidine and brushing 24/24 h. The patients underwent the biofilm removal protocol for 7 days and then were subjected to a new clinical evaluation as to VPI and GBI. Data analysis was performed through stratification and arrangement of the records, in order to carry out the associations with health indicators used in the study, and the statistical tests used were Kappa and t-test for independent and paired samples. Results: A decrease in the VPI and GBI values when comparing baseline to the final evaluation for all groups was observed. Conclusion: Based on the methodology, it was possible to concluded that chlorhexidine associated with the mechanical action of the toothbrush or gauze in the times 12 h and 24 h in the ICU environment presented the same results as regards amount of visible biofilm. How to cite the article: Oliveira MS, Borges AH, Mattos FZ, Semenoff TA, Segundo AS, Tonetto MR, Bandeca MC, Porto AN. Evaluation of different methods for removing oral biofilm in patients admitted to the intensive care unit. J Int Oral Health 2014;6(3):61-4. PMID:25083034

Biological Impact of Senescence Induction in Prostate Cancer Therapy

DTIC Science & Technology

2009-01-01

wells after treatment with decreasing compound concentrations. Data showing chlorhexidine, bithionol, cytarabine and crassin acetate effectively...Doxorubicin were included as a positive control. Of the candidate compounds, methotrexate, cytarabine , chlorhexidine and IC 261 did not induce

Cholorhexidine, octenidine or povidone iodine for catheter related infections: A randomized controlled trial.

PubMed

Bilir, Ayten; Yelken, Birgül; Erkan, Ayse

2013-06-01

Protection of the catheter site by antimicrobial agents is one of the most important factors in the prevention of infection. Povidone iodine and chlorhexidine gluconate are the most common used agents for dressing. The purpose of this study was to compare the effects of povidone iodine, chlorhexidine gluconate and octenidine hydrochloride in preventing catheter related infections. Patients were randomized to receive; 4% chlorhexidine gluconate, 10% povidone iodine or octenidine hydrochlorodine for cutaneous antisepsis. Cultures were taken at the site surrounding catheter insertion and at the catheter hub after removal to help identify the source of microorganisms. Catheter related sepsis was 10.5% in the povidone iodine and octenidine hydrochlorodine groups. Catheter related colonization was 26.3% in povidone iodine group and 21.5% in octenidine hydrochlorodine group. 4% chlorhexidine or octenidine hydrochlorodine for cutaneous disinfection before insertion of an intravascular device and for post-insertion site care can reduce the catheter related colonization.

A study of long-term stability and antimicrobial activity of chlorhexidine, polyhexamethylene biguanide, and silver nanoparticle incorporated in sericin-based wound dressing.

PubMed

Ampawong, Sumate; Aramwit, Pornanong

2017-09-01

In this study, three kinds of antiseptics which were 0.05% chlorhexidine, 0.2% polyhexamethylene biguanide (PHMB), or 200 ppm silver nanoparticle was introduced to incorporate in the sericin-based scaffold to produce the antimicrobial dressing for the treatment of infected chronic wound. The effects of antiseptic incorporation on the stability, release of sericin, and short-term and long-term (6 months) antimicrobial activity of the sericin dressing against gram-negative and gram-positive bacteria were investigated. We showed that the incorporation of each antiseptic did not have significant effect on the internal morphology (pore size ~ 73-105 μm), elasticity (Young's modulus ~ 200-500 kPa), and the sericin release behavior of the sericin-based dressing. The release of sericin from the dressing was prolonged over 120 h and thereafter. Comparing among three antiseptics, 0.05% chlorhexidine incorporated in the sericin dressing showed the highest immediate and long-term (6 months) antimicrobial effect (largest inhibition zone) against most bacteria either gram-positive or gram-negative bacteria. The in vivo safety test following ISO10993 standard (Biological evaluation of medical devices - Part 6: Tests for local effects after implantation) confirmed that the sericin dressing incorporating 0.05% chlorhexidine did not irritate to tissue, comparing with the commercial material used generally in clinic (Allevyn®, Smith & Nephew). We suggested the sericin dressing incorporating 0.05% chlorhexidine for the treatment of infected chronic wound. Chlorhexidine would reduce the risk of infection while the sericin may promote wound healing.

Double-blind, placebo-controlled, randomized study of chlorhexidine prophylaxis for 5-fluorouracil-based chemotherapy-induced oral mucositis with nonblinded randomized comparison to oral cooling (cryotherapy) in gastrointestinal malignancies.

PubMed

Sorensen, Jens Benn; Skovsgaard, Torben; Bork, Ellen; Damstrup, Lars; Ingeberg, Sten

2008-04-01

The purpose was to evaluate prevention of oral mucositis (OM) using chlorhexidine compared with placebo and with oral cooling (cryotherapy) during fluorouracil (5-FU)-based chemotherapy in gastrointestinal (GI) cancer. Patients with previously untreated GI cancer receiving bolus 5-FU/leucovorin chemotherapy were randomized to chlorhexidine mouthrinse 3 times a day for 3 weeks (Arm A), double-blind placebo (normal saline) with the same dose and frequency (Arm B), or cryotherapy with crushed ice 45 minutes during chemotherapy (Arm C). Patients self-reported on severity (CTC-grading) and duration of OM. Among 225 patients randomized, 206 answered the questionnaire (70, 64, and 63 patients in Arms A, B, and C, respectively) and were well balanced with respect to diagnoses, stage, age, sex, smoking habits, and performance status. Mucositis grade 3-4 occurred more frequently in Arm B (33%) than in A (13%, P< .01) and C (11%, P< .005). Duration was significantly longer in B than in both A (P= .035) and C (P= .003). The frequency and duration of OM are significantly improved by prophylactic chlorhexidine and by cryotherapy. The latter is easy and inexpensive but has limited use, as it is drug- and schedule-dependent. The current study is the first double-blind randomized evaluation of prophylactic chlorhexidine in a large adult patient population with solid tumors receiving highly OM-inducing chemotherapy. A role for chlorhexidine in the prevention of OM is suggested, which should be evaluated further.

Surgical hand preparation with chlorhexidine soap or povidone iodine: new methods to increase immediate and residual effectiveness, and provide a safe alternative to alcohol solutions.

PubMed

Herruzo, R; Vizcaino, M J; Yela, R

2018-04-01

Surgical use of 4% chlorhexidine soap (CHX-4) and 10% povidone iodine (PVP-I-10) does not meet the standards defined by EN 12791. To investigate the possibility of increasing the immediate and residual effects of these antiseptics. Over three consecutive weeks, n-propanol, standard CHX-4 and PVP-I-10 were tested in two experimental groups of volunteers. The new method for applying the antiseptic substances involved standard hand rub and rinse of CHX-4 or PVP-I-10, followed by application of an aqueous solution based on 5% chlorhexidine or PVP-I-10 with no further rinsing of the hands prior to donning gloves. Samples were taken to assess immediate and residual effects, analysing the logarithmic reduction of colony-forming units. At t=0 h, n-propanol was superior in bactericidal effect to standard CHX-4 (P<0.05), but the new chlorhexidine protocol was superior to both standard CHX-4 (P<0.01) and n-propanol (P<0.05); the same effect was observed at t=3 h (residual effect). At t=0 h, n-propanol was significantly superior to standard PVP-I-10, but the new PVP-I-10 protocol was superior, although not significantly, to n-propanol. There was no significant residual effect at t=3 h. The new protocol for chlorhexidine application permits surgical hand preparation with chlorhexidine, as a safe alternative to alcohol solutions, because it meets the standards defined by EN 12791. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Clinical efficacy of turmeric use in gingivitis: A comprehensive review.

PubMed

Stoyell, Karissa A; Mappus, Jennifer L; Gandhi, Mona A

2016-11-01

Gingivitis affects an estimated 80% of the population, and is characterized as the world's most predominant inflammatory periodontal disease. Without intervention, gingivitis can advance to alveolar bone loss. Therefore, the primary goal in patients suffering with gingivitis is to control plaque buildup and soft tissue inflammation. Current guidelines consider chlorhexidine as the gold standard in the prevention and treatment of gingivitis. However, negative side effects of chlorhexidine, including oral mucosal erosion, discoloration of teeth, and bitter taste, provide an opportunity for alternative medications. Turmeric, a commonly used herb, possesses anti-inflammatory, antioxidant, antibacterial, antiviral, and antifungal properties. By virtue of these properties, multiple controlled trials have been performed to investigate the efficacy of turmeric in gingivitis. The aim of this comprehensive review is to summarize and evaluate the evidence on the efficacy of turmeric as compared to chlorhexidine in the prevention and treatment of gingivitis. PubMed, MedLine (Web of Science), and EBSCO (academic search complete) were utilized as primary literature search tools. The following search strategy was used: ((turmeric OR curcumin OR curcuma) AND (gingivitis OR "gum inflammation")). Five reviewed studies show that both turmeric and chlorhexidine significantly decrease plaque index (PI) and gingival index (GI), and can therefore be used in the prevention and treatment of gingivitis. Both chlorhexidine and turmeric can be used as an adjunct to mechanical means in preventing and treating gingivitis. However, trials longer than 21 days with a greater number of patients are necessary to further evaluate the comparison between turmeric and chlorhexidine. Copyright © 2016 Elsevier Ltd. All rights reserved.

Antifungal activity of synthetic antiseptics and natural compounds against Candida dubliniensis before and after in vitro fluconazole exposure.

PubMed

Reginato, Cássia Franco; Bandeira, Laíssa Arévalo; Zanette, Régis Adriel; Santurio, Janio Morais; Alves, Sydney Hartz; Danesi, Cristiane Cademartori

2017-01-01

This study evaluated the susceptibilities of oral candidiasis-derived Candida albicans, fluconazole-resistant (FR) Candida dubliniensis, and fluconazole-susceptible (FS) C. dubliniensis to synthetic antiseptics [chlorhexidine gluconate (CHX), cetylpyridinium chloride (CPC), and triclosan (TRC)] and natural compounds (carvacrol, eugenol and thymol). Susceptibility tests were performed based on the M27-A3 reference method. The fluconazole-resistant C. dubliniensis strains were obtained after prolonged in vitro exposure to increasing fluconazole concentrations. The geometric mean values for minimum inhibitory concentrations and minimum fungicidal concentrations were compared among the groups. Fluconazole-susceptible C. dubliniensis was more sensitive to CPC and TRC than FR C. dubliniensis and C. albicans were. However, eugenol and thymol were more active against FR C. dubliniensis. The fungicidal activities of CHX and TRC were similar for the three groups, and FR C. dubliniensis and C. albicans had similar sensitivities to CPC. The resistance of C. dubliniensis to fluconazole affects its sensitivity the synthetic antiseptics and natural compounds that were tested.

Organically Doped Metals: A New Family of Materials

DTIC Science & Technology

2010-02-25

comparison to their individual components. Biocidal activity tests of ( chlorhexidine digluconate )@Ag revealed high synergistic activity of the...sustainable release of its components, namely chlorhexidine molecules and Ag+. A very encouraging observation has been demonstrated on a E. coli strain, which

Sealing ability of mineral trioxide aggregate (MTA) combined with distilled water, chlorhexidine, and doxycycline.

PubMed

Arruda, Roberta A A; Cunha, Rodrigo S; Miguita, Kenner B; Silveira, Cláudia F M; De Martin, Alexandre S; Pinheiro, Sérgio L; Rocha, Daniel G P; Bueno, Carlos E S

2012-09-01

The aim of this study was to evaluate the sealing ability of mineral trioxide aggregate (MTA Bio) combined with different mixing agents (distilled water, chlorhexidine, doxycycline), used as an apical root-end filling material. Forty-two extracted human teeth were divided into three groups (n = 12); six teeth were used as controls. Root-ends were resected at 90 degrees, 3 mm from the apex. Root-end cavities were prepared using ultrasonic tips and filled with MTA Bio plus distilled water, 2% chlorhexidine solution, or 10% doxycycline solution. Apical sealing was assessed by microleakage of 50% silver nitrate solution. Roots were longitudinally sectioned in a buccolingual plane and analyzed using an operating microscope (20× magnification). Depth of dye leakage into the dentinal walls was measured in millimeters. Results were analyzed using ANOVA and Tukey's test (P = 0.05). MTA Bio plus distilled water showed significantly higher mean leakage results (1.06 mm) when compared with MTA Bio plus doxycycline (0.61 mm), and higher, although not significant, results when compared with MTA Bio plus chlorhexidine (0.79 mm). In conclusion, replacing distilled water with two biologically active mixing agents (doxycycline and chlorhexidine) did not alter the sealing properties of MTABio. The antimicrobial properties of these combinations should be further investigated.

Comparative evaluation of terminalia chebula extract mouthwash and chlorhexidine mouthwash on plaque and gingival inflammation - 4-week randomised control trial.

PubMed

Gupta, Devanand; Gupta, Rajendra Kumar; Bhaskar, Dara John; Gupta, Vipul

2015-01-01

The present study was conducted to assess the effectiveness of Terminalia chebula on plaque and gingival inflammation and compare it with the gold standard chlorhexidine (CHX 0.2%) and distilled water as control (placebo). A double-blind randomised control trial was conducted among undergraduate students who volunteered. They were randomly allocated into three study groups: 1) Terminalia chebula mouthwash (n = 30); 2) chlorhexidine (active control) (n = 30); 3) distilled water (placebo) (n = 30). Assessment was carried out according to plaque score and gingival score. Statistical analysis was carried out to compare the effect of both mouthwashes. ANOVA and post-hoc LSD tests were performed using SPSS version 17 with p ≤ 0.05 considered statistically significant. Our result showed that Terminalia chebula mouthrinse is as effective as chlorhexidine in reducing dental plaque and gingival inflammation. The results demonstrated a significant reduction of gingival bleeding and plaque indices in both groups over a period of 15 and 30 days as compared to the placebo. The results of the present study indicate that Terminalia chebula may prove to be an effective mouthwash. Terminalia chebula extract mouthrinse can be used as an alternative to chlorhexidine mouthrinse as it has similar properties without the side-effects of the latter.

Evaluation of effect of addition of 2% chlorhexidine on the sealing ability of Biodentine: An in vitro study

PubMed Central

Suri, Navleen Kaur; Nikhil, Vineeta; Jha, Padmanabh; Jaiswal, Shikha

2015-01-01

Aim: To evaluate the effect of the addition of 2% chlorhexidine on the sealing ability of Biodentine. Materials and Methods: Forty-six extracted human premolar teeth with single canal and apical foramen were selected, cleaned, and decoronated to standardize the length of 17 mm. Canals were prepared using ProTaper rotary files till size F4. The samples were divided into 2 experimental groups of 20 samples each on the basis of absence/presence of 2% chlorhexidine in liquid: Group BM = Biodentine mixed with the provided liquid, Group BC = Biodentine mixed with 2% chlorhexidine in provided liquid. Three samples, each were assigned to control groups: Group BP (positive control) = No root end filling was placed, Group BN (negative control) = Root ends were filled as in Group BM, and entire external surface was coated with sticky wax. The samples were then evaluated for the apical sealing using fluid filtration method. Results: Results were analyzed using Student's t-test (P ≤ 0.05). Group BC showed the better sealing ability (3.06) as compared to Group BM (3.85). However, the difference was statistically insignificant (P > 0.05). Conclusion: Addition of 2% chlorhexidine to the liquid enhanced the sealing ability of Biodentine. PMID:26752844

Comparative antimicrobial activity, in vitro and in vivo, of soft N-chloramine systems and chlorhexidine.

PubMed Central

Selk, S H; Pogány, S A; Higuchi, T

1982-01-01

Antimicrobial activity of the following four new N-chloramine compounds was evaluated: two chlorinated simple amino acids, a chlorinated half-ester of succinic acid, and a chlorinated half-ester of glutaric acid. For comparison, the known bactericidal agents 3-chloro-4,4-dimethyl-2-oxazolidinone and chlorhexidine were evaluated by the same procedure. The contact germicidal efficiency screen was used to examine the in vitro bactericidal activity of all six compounds in the absence and presence of 5% horse serum or 5% Triton X-100. The four new compounds were found to have greater germicidal activity than the other compounds tested and to exhibit low toxicity and skin irritation values. The in vivo bactericidal activity was evaluated in two studies. In the occlusion test, three of the four new compounds plus chlorhexidine diacetate were tested. The N-chloramines were significantly superior to chlorhexidine in preventing the expansion of the normal flora under occlusion. In the scrub test, a gloved-hand wash method was used to compare the antimicrobial effect of a 1% solution of the chlorinated half-ester of succinic acid in triacetin with that of a commercial germicidal hand wash containing 4% chlorhexidine gluconate. The two preparations exhibited essentially the same hand-degerming activity. PMID:6805433

Extracellular dextran and DNA affect the formation of Enterococcus faecalis biofilms and their susceptibility to 2% chlorhexidine.

PubMed

Li, Weilan; Liu, Hongyan; Xu, Qiong

2012-07-01

Enterococcus faecalis is frequently recovered from root-filled teeth with refractory apical periodontitis. The ability of E. faecalis to form a matrix-encased biofilm contributes to its pathogenicity; however, the role of extracellular dextran and DNA in biofilm formation and its effect on the susceptibility of the biofilm to chlorhexidine remains poorly understood. E. faecalis biofilms were incubated on dentin blocks. The effect of a dextran-degrading enzyme (dextranase) and DNase I on the adhesion of E. faecalis to dentin was measured using the colony-forming unit (CFU) counting method. CFU assays and confocal laser scanning microscopy were used to investigate the influence of dextranase and DNase I on the antimicrobial activity of 2% chlorhexidine. The CFU count assays indicated that the formation of biofilms by E. faecalis was reduced in cells treated with dextranase or DNase I compared with that in untreated cells (P < .05). In addition, we found that treating E. faecalis biofilms with dextranase or DNase I effectively sensitized the biofilms to 2% chlorhexidine (P < .05). Both dextranase and DNase I decrease the adhesion of E. faecalis to dentin and sensitized E. faecalis biofilms to 2% chlorhexidine. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effect of dentin etching and chlorhexidine application on metalloproteinase-mediated collagen degradation

PubMed Central

Raquel, Osorio; Mónica, Yamauti; Estrella, Osorio; Estrella, Ruiz-Requena María; David, Pashley; Franklin, Tay; Manuel, Toledano

2013-01-01

Dentin matrix metalloproteinases (MMPs) are involved in collagen degradation of resin-dentin interfaces. This study evaluated if collagen degradation can be prevented by chlorhexidine after different dentin demineralization procedures. Human dentin demineralization was performed with phosphoric acid (PA), EDTA, or acidic monomers (ClearfilSEBond and XENOV). Specimens were stored (24 h, 1 wk or 3 wk) in the presence or absence of chlorhexidine. In half of the groups, active MMP-2 was incorporated into the storing solution. C-terminal telopeptide determination (ICTP) was performed in the supernatants. Collagen degradation was higher in PA and EDTA-demineralized dentin. Chlorhexidine reduced collagen degradation in these groups only for 24 h. When dentin was demineralized with SEBond or Xeno, collagen degradation was reduced up to 30%, but addition of exogenous MMP-2 significantly increased collagen degradation. In self-etchant treated dentin the inhibitory effect of chlorhexidine on MMPs lasted up to 3 wk. Treating dentin with EDTA, PA or self-etching agents produces enough demineralization to permit cleavage of the exposed collagen. Monomers infiltration may exert protection on demineralized collagen, probably through immobilization of MMPs. The partial inhibitory action of CHX on MMP activity produced by self-etching adhesives was prolonged compared to the short-acting in PA or EDTA-treated dentin. PMID:21244516

pH-controlled drug release for dental applications

NASA Astrophysics Data System (ADS)

Wironen, John Francis

A large proportion of the dental fillings replaced at present are revised because of the perceived presence of a recurrent caries under or adjacent to the restoration. Many of these perceived caries may not exist, while others may go undetected. This work describes the preparation of drug loaded polymer microspheres that sense the presence of the bacteria that cause caries by the associated presence of acid by-products of digestion. These microspheres are designed to swell and release their antimicrobial drugs once the pH drops to a level that would normally cause caries. The preparation of the microspheres as well as their loading with potassium fluoride, chlorhexidine digluconate, chlorhexidine dihydrochloride, chlorhexidine diacetate, and tetracycline hydrochloride are described. A detailed study of the controlled release behavior of fluoride as a function of polymer composition and pH is presented first. A study of the release kinetics of potassium fluoride, chlorhexidine digluconate, diacetate, dihydrochloride, and tetracycline hydrochloride as a function of pH in the same polymer system is then presented. Additional studies of the swelling kinetics of chlorhexidine-loaded microspheres in various pH buffers are discussed with special reference to correlations with the controlled-release data. Finally, an experiment in which the microspheres are tested in an in vitro bacteria model that includes Streptococcus mutans is presented and discussed in detail.

Chlorhexidine avoids skin bacteria recolonization more than triclosan.

PubMed

Macias, Juan H; Alvarez, Mildred F; Arreguin, Virginia; Muñoz, Juan M; Macias, Alejandro E; Alvarez, Jose A

2016-12-01

We do not know whether differences exist between the residual effect of 2% chlorhexidine in 70% isopropyl alcohol when compared with 1% triclosan in 70% isopropyl alcohol. Using an analytic, longitudinal, controlled, and comparative experimental trial, with blinded measurements, we recruited healthy, adult volunteers from the University of Guanajuato who completed a stabilization phase of skin microbiota and had no history of skin allergies. Four 25-cm 2 areas of the inner surface of the forearms were designated for study: unscrubbed control for establishing baseline bacterial counts, scrubbed control with tridistilled water, scrubbed with chlorhexidine, and scrubbed with triclosan. Quantitative cultures were taken of all the areas at 0, 3, and 24 hours, using agar plates with neutralizing agents. A total of 135 healthy volunteers were tested. At 24 hours, the unscrubbed control counts were 288 CFU/cm 2 , whereas the scrubbed control counts were 96 CFU/cm 2 ; 24 CFU/cm 2 for chlorhexidine and 96 CFU/cm 2 for triclosan (Kruskal-Wallis χ 2 H = 64.27; P <.001). Chlorhexidine is the best antiseptic option when a prolonged antiseptic effect is needed; for instance, when implanting medical devices or performing surgical procedures. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Delmopinol-induced matrix removal facilitates photodynamic therapy and chlorhexidine methods for disinfecting mixed oral biofilms

NASA Astrophysics Data System (ADS)

Rogers, Stephen Christopher

It is often observed that the slimy matrixes of various bacterial-formed biofilms can limit their disinfection. This investigation demonstrated that disinfection effectiveness by either photodynamic therapy (PDT) or chlorhexidine irrigation is significantly improved by collapse of that matrix using the non-bactericidal reagent delmopinol as part of the treatment sequence. Cyclic shear-producing conditions were used to grow 4-day, whole salivary and growth media biofilms on glow-discharge-treated polystyrene (N=46) and mini-germanium internal reflection prisms to serve in a periodontal crypt model of disinfection by either methylene-blue-mediated PDT or by chlorhexidine irrigation. Assays for bacterial viability, with and without treatments, were performed by alamarBlueRTM fluorescent methods, statistically applied (ANOVA, Tukey's HSD). Multiple Attenuated Internal Reflection Infrared (MAIR-IR) assays confirmed selective removal of the predominantly polysaccharide matrix materials by the delmopinol treatment, but not by equivalent water or chlorhexidine methods. Confocal-IR microscopy showed that the delmopinol reagent, alone, caused about one-third of each wet biofilm to be removed, while bacterial re-growth was confirmed by alamarBlueRTM assay. Chlorhexidine and PDT suppression of bacterial activity without regrowth was significantly improved with the added delmopinol treatment, and is likely to provide similarly beneficial results in the effective disinfection of diverse biofilms in many settings.

"Nature cures:" An alternative herbal formulation as a denture cleanser.

PubMed

Sushma, R; Sathe, Tanuja Tanaji; Farias, Anand; Sanyal, Pronob Kumar; Kiran, Shashi

2017-01-01

Candida albicans is one of the microorganisms which harbor the oral cavity, especially in elderly. However, the incidence of existence of this increases in patients using removable dental prosthesis. There is therefore a need to test the anticandidal efficacy of these cost-effective, easily available products to be used as routine denture cleansers. (1) To evaluate antifungal properties of triphala churna on the heat cure denture base material. (2) To evaluate the antifungal effect of chlorhexidine gluconate on the heat cure denture base material. (3) To compare the antifungal effect of triphala churna and chlorhexidine gluconate with a control. (4) To evaluate which among triphala churna and chlorhexidine gluconate has a better antifungal property on the heat cure denture base material. Study population consisted of sixty dentures wearers from those attending the Outpatient Department of Prosthodontics of the School of Dentistry, Krishna Institute of Medical Sciences Deemed University, Karad. Swabs were collected from the dentures before and after the use of triphala and chlorhexidine. The swabs were cultured on Sabouraud dextrose agar and the total Candida counts were determined. Triphala as an antifungal is shown to have more efficacy than the conventional chlorhexidine mouthwash. Résumé Arrière-plan: Candida albicans est l'un des micro-organismes qui abritent la cavité buccale surtout chez les personnes âgées. Cependant, l'incidence de l'existence de cette augmentation chez les patients utilisant des prothèses dentaires amovibles. Il est donc nécessaire de tester l'efficacité anticancédique de ces produits rentables et faciles à utiliser pour être utilisés comme nettoyants de routine pour prothèses dentaires. Buts et Objectifs: (1) Évaluer les propriétés antifongiques de Triphala churna sur le matériau de base de la prothèse thermo-durcissable. (2) Évaluer l'effet antifongique du gluconate de chlorhexidine sur le matériau de base de la prothèse thermo-durcissable. (3) Comparer l'effet antifongique de Triphala churna et du gluconate de chlorhexidine avec un témoin. (4) Évaluer lequel parmi Triphala churna et le gluconate de chlorhexidine a une meilleure propriété antifongique sur le matériel de base de la prothèse de durcissement à chaud. Matériaux et Méthode: La population de l'étude était constituée de soixante porteurs de prothèses dentaires de ceux qui fréquentaient le Département de Prosthodontie de l'École des Sciences Dentaires de l'Institut Krishna des Sciences Médicales de l'Université de Karad. Des prélèvements ont été effectués sur les prothèses avant et après l'utilisation de Triphala et de chlorhexidine. On a cultivé les écouvillons sur de l'agar Sabouraud dextrose et on a déterminé le nombre total de candida. Triphala comme un anti fongique est démontré pour avoir plus d'efficacité que le lavage de la bouche classique chlorhexidine.

Effectiveness of 4% chlorhexidine umbilical cord care on neonatal mortality in Southern Province, Zambia (ZamCAT): a cluster-randomised controlled trial.

PubMed

Semrau, Katherine E A; Herlihy, Julie; Grogan, Caroline; Musokotwane, Kebby; Yeboah-Antwi, Kojo; Mbewe, Reuben; Banda, Bowen; Mpamba, Chipo; Hamomba, Fern; Pilingana, Portipher; Zulu, Andisen; Chanda-Kapata, Pascalina; Biemba, Godfrey; Thea, Donald M; MacLeod, William B; Simon, Jonathon L; Hamer, Davidson H

2016-11-01

Chlorhexidine umbilical cord washes reduce neonatal mortality in south Asian populations with high neonatal mortality rates and predominantly home-based deliveries. No data exist for sub-Saharan African populations with lower neonatal mortality rates or mostly facility-based deliveries. We compared the effect of chlorhexidine with dry cord care on neonatal mortality rates in Zambia. We undertook a cluster-randomised controlled trial in Southern Province, Zambia, with 90 health facility-based clusters. We enrolled women who were in their second or third trimester of pregnancy, aged at least 15 years, and who would remain in the catchment area for follow-up of 28 days post-partum. Newborn babies received clean dry cord care (control) or topical application of 10 mL of a 4% chlorhexidine solution once per day until 3 days after cord drop (intervention), according to cluster assignment. We used stratified, restricted randomisation to divide clusters into urban or two rural groups (located <40 km or ≥40 km to referral facility), and randomly assigned clusters (1:1) to use intervention (n=45) or control treatment (n=45). Sites, participants, and field monitors were aware of their study assignment. The primary outcomes were all-cause neonatal mortality within 28 days post-partum and all-cause neonatal mortality within 28 days post-partum among babies who survived the first 24 h of life. Analysis was by intention to treat. Neonatal mortality rate was compared with generalised estimating equations. This study is registered at ClinicalTrials.gov (NCT01241318). From Feb 15, 2011, to Jan 30, 2013, we screened 42 356 pregnant women and enrolled 39 679 women (mean 436·2 per cluster [SD 65·3]), who had 37 856 livebirths and 723 stillbirths; 63·8% of deliveries were facility-based. Of livebirths, 18 450 (99·7%) newborn babies in the chlorhexidine group and 19 308 (99·8%) newborn babies in the dry cord care group were followed up to day 28 or death. 16 660 (90·0%) infants in the chlorhexidine group had chlorhexidine applied within 24 h of birth. We found no significant difference in neonatal mortality rate between the chlorhexidine group (15·2 deaths per 1000 livebirths) and the dry cord care group (13·6 deaths per 1000 livebirths; risk ratio [RR] 1·12, 95% CI 0·88-1·44). Eliminating day 0 deaths yielded similar findings (RR 1·12, 95% CI 0·86-1·47). Despite substantial reductions previously reported in south Asia, chlorhexidine cord applications did not significantly reduce neonatal mortality rates in Zambia. Chlorhexidine cord applications do not seem to provide clear benefits for newborn babies in settings with predominantly facility-based deliveries and lower (<30 deaths per 1000 livebirths) neonatal mortality rates. Bill & Melinda Gates Foundation. Copyright © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.

Comparative evaluation of antibacterial property and substantivity of chlorhexidine containing dentifrices with sodium lauryl sulfate and Tween as surfactants: an in vivo study.

PubMed

Venu, V; Prabhakar, A R; Basappa, N

2013-01-01

The aim of the study was to determine the antibacterial property and substantivity of chlorhexidine containing dentifrices with sodium lauryl sulfate (SLS) and Tween as surfactants. It is a double-blind cross over the study, a total of 20 children within their mixed dentition period (7-13 year) having Streptococci mutans count more than 10(6) were selected for the main study. Three types of chlorhexidine containing dentifrices were used with a washout period of 1 week. Out of the three toothpastes, one was without surfactant and other two toothpastes contained SLS and Tween as surfactants respectively. 20 volunteers brushed for 1 min during the study day with their assigned toothpaste. Saliva samples were collected before brushing, immediately after brushing and 1, 3, 5, and 7 hand sent for microbial analysis. The culture carried out by inoculating saliva sample onto Mitis salivarius agar for selective isolation of S. mutans followed by counting of colony forming unit. Group I and III (Chlorhexidine and CHX + Tween) had shown statistically significant reduction in bacterial count until 7 h when compared to their baseline values ( P < 0.001). Group II toothpaste (CHX + SLS) had shown significant reduction in bacterial count until 3 h only. On inter group comparison, Group III had shown good amount of percentage reduction in bacterial count when compared to other groups. CHX + Tween toothpaste had shown statistically significant reduction in antibacterial activity and substantivity than other groups. These findings show chlorhexidine containing toothpaste with non-ionic surfactant will be able to maintain the antibacterial property and substantivity of chlorhexidine.

Effect of chlorhexidine/silver sulfadiazine-impregnated central venous catheters in an intensive care unit with a low blood stream infection rate after implementation of an educational program: a before-after trial.

PubMed

Schuerer, Douglas J E; Zack, Jeanne E; Thomas, James; Borecki, Ingrid B; Sona, Carrie S; Schallom, Marilyn E; Venker, Melissa; Nemeth, Jennifer L; Ward, Myrna R; Verjan, Linda; Warren, David K; Fraser, Victoria J; Mazuski, John E; Boyle, Walter A; Buchman, Timothy G; Coopersmith, Craig M

2007-08-01

Current guidelines recommend using antiseptic- or antibiotic-impregnated central venous catheters (CVCs) if, following a comprehensive strategy to prevent catheter-related blood stream infection (CR-BSI), infection rates remain above institutional goals based on benchmark values. The purpose of this study was to determine if chlorhexidine/silver sulfadiazine-impregnated CVCs could decrease the CR-BSI rate in an intensive care unit (ICU) with a low baseline infection rate. Pre-intervention and post-intervention observational study in a 24-bed surgical/trauma/burn ICU from October, 2002 to August, 2005. All patients requiring CVC placement after March, 2004 had a chlorhexidine/silver sulfadiazine-impregnated catheter inserted (post-intervention period). Twenty-three CR-BSIs occurred in 6,960 catheter days (3.3 per 1,000 catheter days)during the 17-month control period. After introduction of chlorhexidine/silver sulfadiazine-impregnated catheters, 16 CR-BSIs occurred in 7,732 catheter days (2.1 per 1,000 catheter days; p = 0.16). The average length of time required for an infection to become established after catheterization was similar in the two groups (8.4 vs. 8.6 days; p = 0.85). Chlorhexidine/silver sulfadiazine-impregnated catheters did not result in a statistically significant change in the microbiological profile of CR-BSIs, nor did they increase the incidence of resistant organisms. Although chlorhexidine/silver sulfadiazine-impregnated catheters are useful in specific patient populations, they did not result in a statistically significant decrease in the CR-BSI rate in this study, beyond what was achieved with education alone.

[The Effect of Dongchimi Juice Containing Kimchi Lactobacillus on the Oral Health of Patients at a Long-Term Care Hospital: Comparison with Chlorhexidine Solution].

PubMed

Lee, Seung Ah; Lee, Dongsuk

2017-08-01

The aim of this study was to identify the effect of Dongchimi juice containing kimchi Lactobacillus as an oral hygiene agent and to compare it with that of chlorhexidine solution (0.12% dilution). This study employed a pretest-posttest experimental design in which a single group of patients was exposed to two different treatments over a period of time. The study included 32 patients hospitalized at a long-term care hospital in Korea. Data were collected between August 12, 2016 and September 28, 2016. The patients first used chlorhexidine solution as an oral care agent for 1 week. After an interval of 2 weeks, they used Dongchimi juice for 1 week. Each agent was applied 2 times a day depending on the protocol. The oral status of the patients was measured using Beck's Oral Exam Guide (OEG) scores. The number of pathogens in the oral cavity was counted by culture, and the patients' subjective satisfaction score for each oral agent was measured using a visual analogue scale. T-test and Mann-Whitney test were performed to identify significant differences between Dongchimi juice and chlorhexidine solution by using PASW Statistics for Windows, Version 18.0 (SPSS Inc., Chicago, IL, USA). The OEG score was not statistically different with the use of chlorhexidine solution and Dongchimi juice. However, decreasing number of pathogens and the subjective satisfaction score were higher with Dongchimi juice than with the chlorhexidine solution. These findings support the use of Dongchimi juice containing kimchi Lactobacillus as an oral hygiene agent for Korean patients. © 2017 Korean Society of Nursing Science

Novel Multiplex PCR Assay for Detection of Chlorhexidine-Quaternary Ammonium, Mupirocin, and Methicillin Resistance Genes, with Simultaneous Discrimination of Staphylococcus aureus from Coagulase-Negative Staphylococci

PubMed Central

McClure, Jo-Ann; Zaal DeLongchamp, Johanna; Conly, John M.

2017-01-01

ABSTRACT Methicillin-resistant Staphylococcus aureus (MRSA) is a clinically significant pathogen that is resistant to a wide variety of antibiotics and responsible for a large number of nosocomial infections worldwide. The Agency for Healthcare Research and Quality and the Centers for Disease Control and Prevention recently recommended the adoption of universal mupirocin-chlorhexidine decolonization of all admitted intensive care unit patients rather than MRSA screening with targeted treatments, which raises a serious concern about the selection of resistance to mupirocin and chlorhexidine in strains of staphylococci. Thus, a simple, rapid, and reliable approach is paramount in monitoring the prevalence of resistance to these agents. We developed a simple multiplex PCR assay capable of screening Staphylococcus isolates for the presence of antiseptic resistance genes for chlorhexidine and quaternary ammonium compounds, as well as mupirocin and methicillin resistance genes, while simultaneously discriminating S. aureus from coagulase-negative staphylococci (CoNS). The assay incorporates 7 PCR targets, including the Staphylococcus 16S rRNA gene (specifically detecting Staphylococcus spp.), nuc (distinguishing S. aureus from CoNS), mecA (distinguishing MRSA from methicillin-susceptible S. aureus), mupA and mupB (identifying high-level mupirocin resistance), and qac and smr (identifying chlorhexidine and quaternary ammonium resistance). Our assay demonstrated 100% sensitivity, specificity, and accuracy in a total of 23 variant antiseptic- and/or antibiotic-resistant control strains. Further validation of our assay using 378 randomly selected and previously well-characterized local clinical isolates confirmed its feasibility and practicality. This may prove to be a useful tool for multidrug-resistant Staphylococcus monitoring in clinical laboratories, particularly in the wake of increased chlorhexidine and mupirocin treatments. PMID:28381601

Comparative Evaluation of Two Final Irrigation Techniques for the Removal of Precipitate Formed by the Interaction between Sodium Hypochlorite and Chlorhexidine.

PubMed

Metri, Malasiddappa; Hegde, Swaroop; Dinesh, K; Indiresha, H N; Nagaraj, Shruthi; Bhandi, Shilpa H

2015-11-01

To evaluate the effectiveness of two final irrigation techniques for the removal of precipitate formed by the interaction between sodium hypochlorite (NaOCl) and chlorhexidine (CHX). Sixty freshly extracted human maxillary incisor teeth were taken and randomly divided into three groups, containing 20 teeth each. Group 1 (control group), were irrigated with 5 ml of 2.5% NaOCl and a final flush with 5 ml of 2% chlorhexidine. Group 2 were irrigated with 5 ml of 2.5% NaOCl and 5 ml of 2% chlorhexidine followed by 5 ml of saline and agitated with F-files. Group 3 were irrigated with 5 ml of 2.5% NaOCl and 5 ml of 2% chlorhexidine followed by 5 ml of 15% citric acid and passively agitated with ultrasonics. A thin longitudinal groove was made along the buccal and lingual aspect of the root using diamond disks and split with chisel and mallet. Both halves of the split tooth will be examined under stereomicroscope. Results were tabulated and analyzed statistically using analysis of variance (ANOVA) and Mann-Whitney U test. There was a significant difference between the mean values (p < 0.05) in groups 2 and 3 compared to group 1 at each level. Passive ultrasonic irrigation is more effective than the F-file agitation technique to remove the precipitate at all three levels measured. Combination of sodium hypochlorite and chlorhexidine irrigation protocol has been practiced since from many years to achieve good results. However, it has adverse effect in the form of precipitate and which is considered to be a carcinogenic in nature, hence this precipitate should be removed.

Antiseptic solutions modulate the paracrine-like activity of bone chips: differential impact of chlorhexidine and sodium hypochlorite.

PubMed

Sawada, Kosaku; Caballé-Serrano, Jordi; Bosshardt, Dieter D; Schaller, Benoit; Miron, Richard J; Buser, Daniel; Gruber, Reinhard

2015-09-01

Chemical decontamination increases the availability of bone grafts; however, it remains unclear whether antiseptic processing changes the biological activity of bone. Bone chips were incubated with four different antiseptic solutions including (1) povidone-iodine (0.5%), (2) chlorhexidine diguluconate (0.2%), (3) hydrogen peroxide (1%) and (4) sodium hypochlorite (0.25%). After 10 min. of incubation, changes in the capacity of the bone-conditioned medium (BCM) to modulate gene expression of gingival fibroblasts was investigated. Conditioned medium obtained from freshly prepared bone chips increased the expression of TGF-β target genes interleukin 11 (IL11), proteoglycan4 (PRG4), NADPH oxidase 4 (NOX4), and decreased the expression of adrenomedullin (ADM), and pentraxin 3 (PTX3) in gingival fibroblasts. Incubation of bone chips with 0.2% chlorhexidine, followed by vigorously washing resulted in a BCM with even higher expression of IL11, PRG4 and NOX4. These findings were also detected with a decrease in cell viability and an activation of apoptosis signalling. Chlorhexidine alone, at low concentrations, increased IL11, PRG4 and NOX4 expression, independent of the TGF-β receptor I kinase activity. In contrast, 0.25% sodium hypochlorite almost entirely abolished the activity of BCM, whereas the other two antiseptic solutions, 1% hydrogen peroxide and 0.5% povidone-iodine, had relatively no impact respectively. These in vitro findings demonstrate that incubation of bone chips with chlorhexidine differentially affects the activity of the respective BCM compared to the other antiseptic solutions. The data further suggest that the main effects are caused by chlorhexidine remaining in the BCM after repeated washing of the bone chips. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Impact of 4.0% chlorhexidine cord cleansing on the bacteriologic profile of the newborn umbilical stump in rural Sylhet District, Bangladesh: a community-based, cluster-randomized trial.

PubMed

Mullany, Luke C; Saha, Samir K; Shah, Rasheduzzaman; Islam, Mohammad Shahidul; Rahman, Mostafiz; Islam, Maksuda; Talukder, Radwanur Rahman; El Arifeen, Shams; Darmstadt, Gary L; Baqui, Abdullah H

2012-05-01

Randomized trials from South Asia indicate umbilical cord chlorhexidine cleansing reduces mortality and omphalitis. No community-based data are available on bacteriological profile of the cord, early neonatal colonization dynamics, or impact of cord cleansing on colonizing organisms. Such data could clarify the design of scaled chlorhexidine interventions. Umbilical swabs were collected at home (days 1, 3, 6) after birth from infants participating in a trial of 3 cord-care regimens (no chlorhexidine, single cleansing, multiple cleansing) in Sylhet, Bangladesh. Overall and organism-specific positivity rates were estimated by cord-care regimen and by day of collection. Between September 2008 and October 2009, 1923 infants contributed 5234 umbilical swabs. Positivity rate was high (4057 of 5234, 77.5%) and varied substantially across groups. Immediate (day 1) reductions in cord colonization were observed in single- (prevalence rate ratio = 0.75, 95% confidence interval: 0.70-0.81) and multiple- (prevalence rate ratio = 0.71, 95% confidence interval: 0.66-0.77) cleansing groups. Reductions persisted and increased in magnitude through day 6 only if babies received multiple applications. On days 1, 3, and 6, respectively, multiple cleansing consistently reduced invasive organisms such as Escherichia coli (49%, 64%, and 42% lower), Klebsiella pneumoniae (46%, 53%, and 33% lower), and Staphylococcus aureus (34%, 84%, and 85% lower). Cord cleansing with 4.0% chlorhexidine immediately after birth reduces overall and organism-specific colonization of the stump. Reductions are greater and sustained longer with daily cleansing through the first week of life, suggesting that programs promoting chlorhexidine cleansing should favor multiple over single applications.

Effect of smoking on the results of a chlorhexidine digluconate treatment extended up to 3 months after scaling and root planing-a pilot study.

PubMed

Stratul, Stefan-Ioan; Sculean, Anton; Rusu, Darian; Didilescu, Andreea; Kasaj, Adrian; Jentsch, Holger

2011-01-01

The aim of the study was to evaluate the impact of smoking on a prolongated chlorhexidine digluconate regimen after scaling and root planing. Forty-two smokers (test group) and 85 nonsmoking patients (control group) with generalized chronic periodontitis were examined for clinical attachment level (CAL), probing depth (PD), bleeding on probing (BoP), and Plaque Index (Pl) at baseline and after 1 and 3 months. During scaling and root planing, a 0.2% chlorhexidine digluconate solution and a 1% chlorhexidine digluconate gel were used. The subjects used a 0.2% chlorhexidine digluconate solution twice daily for 3 months. The Mann-Whitney U and Wilcoxon tests were used for statistical analysis. There were significant improvements of all studied variables after 1 and 3 months in both groups. After 3 months, the mean improvement in the test group was 1.62 mm for CAL, 2.85 mm for PD, and 48% for BoP; in the control group, the values were 2.18 mm for CAL, 2.81 mm for PD, and 47% for BoP. Only the maximum changes of CAL between 1 and 3 months (test group, 0.32 mm vs 0.69 mm in the control group) and PD (test group, 0.47 mm vs 0.76 mm in the control group) were significantly different between the groups (P < .05 and P = .05, respectively). The present data appear to suggest that the use of chlorhexidine digluconate twice daily during a period of 3 months following nonsurgical periodontal therapy may result in significant clinical improvements in smokers and nonsmokers.

Adjunctive effect of chlorhexidine antiseptics in mechanical periodontal treatment: first results of a preliminary case series.

PubMed

Calderini, A; Pantaleo, G; Rossi, A; Gazzolo, D; Polizzi, E

2013-08-01

The aim of the present case series was to evaluate the clinical and microbiological effects of a single session of mechanical and manual scaling and root planing (SRP) combined with the use of two different chlorhexidine formulations in the treatment for generalized chronic periodontitis. Ten patients affected by chronic periodontal disease with periodontal probing depth (PPD) ≥ 5 mm were treated with SRP plus local chlorhexidine. In each patient, similar teeth, treated with SRP with the adjunctive use of chlorhexidine digluconate and dihydrochloride or chlorhexidine gluconate, respectively, were selected and assigned to a test and a control group. In both groups, PPD, bleeding on probing (BOP) parameters, total bacterial counts (TBC) and quality of periodontal bacteria at time 0 and 6 weeks after treatment were measured. PPD significantly decreased over time both in the test and in the control group; however, no significant differences between the two groups were observed. BOP and TBC were significantly lower in the test than in the control group 6 weeks after treatment. In the post-treatment revaluation, a significant decrease both in the treatment and in the control group, for each of the single periodontal pathogens, was observed. In this study--a preliminary case series with small sample size and short follow-up--the adjunctive use of chlorhexidine (CHX) to SRP resulted in clinical and microbiological benefits in the treatment for generalized chronic periodontitis. A CHX gel formulation consisting of CHX digluconate and CHX dihydrochloride seems to lead some additional benefits over SRP plus CHX gluconate in the short term. Additional investigations are needed to evaluate the effectiveness of this antiseptic therapy. © 2012 John Wiley & Sons A/S.

Efficacy of peracetic acid in rapid disinfection of Resilon and gutta-percha cones compared with sodium hypochlorite, chlorhexidine, and povidone-iodine.

PubMed

Subha, N; Prabhakar, V; Koshy, Minu; Abinaya, K; Prabu, M; Thangavelu, Lavanya

2013-10-01

The aim of this investigation was to compare the effectiveness of 3% sodium hypochlorite (NaOCl), 2% chlorhexidine, 1% peracetic acid, and 10% povidone-iodine in the rapid disinfection of Resilon (Pentron Clinical Technologies, LLC, Wallingford, CT) and gutta-percha cones contaminated with Enterococcus faecalis and Bacillus subtilis. Two hundred fifty-six samples consisting of 128 gutta-percha cones and 128 Resilon cones were used in this study. The materials were tested for disinfection according to the type of solution (3% NaOCl, 2% chlorhexidine, 1% peracetic acid, or 10% povidone-iodine), the time of exposure to each solution (1 or 5 minutes), and the type of microorganisms (E. faecalis or B. subtilis). Subsequent to the disinfection, samples were placed in test tubes containing 10 mL Mueller-Hinton broth and incubated at 37°C for 7 days. All test tubes were observed at 24-hour intervals and visually checked for turbidity, signifying microbial growth. In this study, 1% peracetic acid showed the best results for both 1 minute and 5 minutes of disinfection, 2% chlorhexidine showed the second best results although it was statistically at par with peracetic acid, and 3% hypochlorite ranked third in disinfection; this was statistically significant when compared with peracetic acid and chlorhexidine. Disinfection by povidone-iodine was the least within all the groups for both contact times although disinfection for 5 minutes showed better results than disinfection for 1 minute for gutta-percha. The outcome of this study confirmed the efficacy of 1% peracetic acid and 2% chlorhexidine in the rapid disinfection of both Resilon and gutta-percha. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The efficacy of 2% chlorhexidine gluconate in 70% alcohol compared with 10% povidone iodine in reducing blood culture contamination in pediatric patients.

PubMed

Tangsathapompong, Auchara; Banjongmanee, Pornumpa; Unrit, Kengkaj; Sritipsukho, Paskorn; Mungkornkaew, Narisara; Sajak, Sirinporn

2014-08-01

Blood culture is the gold standard for diagnosis of septicemia. However; false-positive blood cultures are associated with increased health care costs due to unnecessary treatment. To evaluate the efficacy of 2% chlorhexidine gluconate in 70% alcohol compared with 10% povidone iodine in reducing blood culture contamination inpediatricpatients. This is a prospective study of pediatric patients who were admitted at a tertiary-care hospital. Pediatric patients who neededpercutaneous blood cultures were recruitedfrom two general pediatric wards and the pediatric intensive care unit. The authors used 10% povidone iodine as an antiseptic in odd months and 2% chlorhexidine gluconate in 70% alcohol as an antiseptic in even months in obtaining the blood culture samples. There were 1,269 blood culture specimens taken from 821 patients. 654 specimens used 10%povidone iodine as an antiseptic and 619 specimens used 2% chlorhexidine gluconate in 70% alcohol as an antiseptic. The 10% povidone iodine group and the 2% chlorhexidine gluconate in 70% alcohol group had the risk of blood culture contamination of 3.21% (95%CI: 2.00%-4.87%) and 2.28% (95% CI: 1.25%-3.79%) respectively. The risk difference ofblood culture contamination was 0.93% (95% confidence interval: 0. 86-2.72%) with p = 0.31. The most common contamination organism was Coagulase negative staphylococci (68.57%). No adverse skin reactions were observed in both antiseptic solutions groups. Use of2% chlorhexidine gluconate in 70% alcohol as an antiseptic seems to reduce the risk of blood culture contamination compared to use of 10% povidone iodine. In addition, neither of the antiseptic solutions resulted in adverse skin reactions.

Comparison of efficacy of herbal disinfectants with chlorhexidine mouthwash on decontamination of toothbrushes: An experimental trial.

PubMed

Anand, P J Swathy; Athira, S; Chandramohan, Sabari; Ranjith, K; Raj, V Veena; Manjula, V D

2016-01-01

Toothbrushes in regular use can become heavily contaminated with microorganisms, which can cause infection or reinfection. There is a need for toothbrush disinfection methods, which are rapidly effective, cost-effective, nontoxic, and that can be easily implemented. To compare the efficacy of 3% neem, garlic of concentration 4.15 mg/mL and green tea of concentration 40 mg/mL with 0.2% chlorhexidine mouthwash as toothbrush disinfectants. The study was a parallel in vitro comparative experimental trial conducted among 75 randomly selected boys aged between 18 years and 21 years. The subjects were divided into five groups, namely, Group I, Group II, Group III, Group IV, and Group V. They were provided with a new set of precoded toothbrushes and nonfluoridated tooth pastes. After 14 days of tooth brushing, the toothbrushes were immersed in antimicrobial solution for 12 h [Group I--distilled water (control), Group II--3% neem, Group III--garlic of concentration 4.15 mg/mL, Group IV--green tea of concentration 40 mg/mL, and Group V--0.2% chlorhexidine] and then subjected to microbial analysis to check the presence of Streptococcus mutans. The t-test and analysis of variance (ANOVA) were done using Statistical Package for the Social Sciences (SPSS) software version 16. All test solutions showed a statistically significant reduction of Streptococcus mutans count (P < 0.001). There was no statistical difference between the efficacies of neem, garlic, and green tea when compared with chlorhexidine mouthwash (P > 0.05). Neem, garlic, and green tea are equally efficacious as chlorhexidine and these herbal products can be used as potent alternatives to chlorhexidine as disinfectant for toothbrushes.

Preoperative Disinfection of Surgeons' Hands: Use of Alcoholic Solutions and Effects of Gloves on Skin Flora

PubMed Central

Lowbury, E. J. L.; Lilly, H. A.; Ayliffe, G. A. J.

1974-01-01

A single application of about 10 ml of 95% alcoholic chlorhexidine (0·5%) or tetrabrom-o-methyl phenol (0·1%) rubbed on to the hands until they were dry led to mean reduction in viable bacterial counts from standard handwashings of 97·9 ± 1·09% and 91·8 ± 4·63% respectively. After six of such treatments, three on each of two successive days, the mean reductions in relation to viable counts before the first treatment were 99·7 ± 0·09% for alcoholic chlorhexidine and 99·5 ± 0·17% for tetrabrom-o-methyl phenol. These reductions were greater than those obtained with 4% chlorhexidine detergent solution— 87·1 ± 3·5% and 98·2 ± 1·6%, and with 95% or 70% ethyl alcohol and with aqueous 0·5% chlorhexidine. Preoperative washing of the surgeon's hands with alcoholic chlorhexidine used without addition of water is more effective and less expensive than handwashing with antiseptic detergent preparations and running water. The viable counts of washings from hands treated with various antiseptics, including ethyl alcohol, were lower in relation to the pretreatment levels when gloves had been worn for three hours than when samples for counts were taken immediately after the antiseptic treatment. No such difference was found in samplings from hands washed with unmedicated soap. Tests for residual action of antiseptics on the skin showed a greater effect with alcoholic chlorhexidine than with tetrabrom-o-methyl phenol, though both showed greater residual activity than an Irgasan DP 300 detergent preparation. No residual action was shown after 70% ethyl alcohol. PMID:4609555

Novel Multiplex PCR Assay for Detection of Chlorhexidine-Quaternary Ammonium, Mupirocin, and Methicillin Resistance Genes, with Simultaneous Discrimination of Staphylococcus aureus from Coagulase-Negative Staphylococci.

PubMed

McClure, Jo-Ann; Zaal DeLongchamp, Johanna; Conly, John M; Zhang, Kunyan

2017-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a clinically significant pathogen that is resistant to a wide variety of antibiotics and responsible for a large number of nosocomial infections worldwide. The Agency for Healthcare Research and Quality and the Centers for Disease Control and Prevention recently recommended the adoption of universal mupirocin-chlorhexidine decolonization of all admitted intensive care unit patients rather than MRSA screening with targeted treatments, which raises a serious concern about the selection of resistance to mupirocin and chlorhexidine in strains of staphylococci. Thus, a simple, rapid, and reliable approach is paramount in monitoring the prevalence of resistance to these agents. We developed a simple multiplex PCR assay capable of screening Staphylococcus isolates for the presence of antiseptic resistance genes for chlorhexidine and quaternary ammonium compounds, as well as mupirocin and methicillin resistance genes, while simultaneously discriminating S. aureus from coagulase-negative staphylococci (CoNS). The assay incorporates 7 PCR targets, including the Staphylococcus 16S rRNA gene (specifically detecting Staphylococcus spp.), nuc (distinguishing S. aureus from CoNS), mecA (distinguishing MRSA from methicillin-susceptible S. aureus ), mupA and mupB (identifying high-level mupirocin resistance), and qac and smr (identifying chlorhexidine and quaternary ammonium resistance). Our assay demonstrated 100% sensitivity, specificity, and accuracy in a total of 23 variant antiseptic- and/or antibiotic-resistant control strains. Further validation of our assay using 378 randomly selected and previously well-characterized local clinical isolates confirmed its feasibility and practicality. This may prove to be a useful tool for multidrug-resistant Staphylococcus monitoring in clinical laboratories, particularly in the wake of increased chlorhexidine and mupirocin treatments. Copyright © 2017 American Society for Microbiology.

Chlorhexidine and tooth-brushing as prevention strategies in reducing ventilator-associated pneumonia rates.

PubMed

Roberts, Nesta; Moule, Pam

2011-01-01

Ventilator-associated pneumonia (VAP) is a common complication of mechanical ventilation after endotracheal intubation. The role of chlorhexidine and tooth-brushing has been considered as a clinical intervention to reduce infection rates, however, evidence to inform this needs appraising. This paper presents a critical review on the effect of chlorhexidine gluconate (CHX) and tooth-brushing in decreasing rates of VAP in mechanically ventilated adult patients cared for in intensive care settings. A literature search was conducted using a number of bibliographic databases (n = 6). A number of parameters were used to exclude irrelevant papers. A total n = 17 papers were located and accessed, which were directly related to the field. Eight studies that met the criteria and addressed the study aims were reviewed. CHX was successful in reducing the rate of VAP and using a combination of CHX and colistine resulted in better oropharyngeal decontamination which reduced and delayed VAP. Chlorhexidine was also effective in reducing dental plaque in patients cared for in intensive care and had the potential to reduce nosocomial infections. Results of studies investigating the use of tooth-brushing in reducing VAP incidence proved inconsistent, although all recommend tooth-brushing as important in maintaining good oral hygiene. The use of chlorhexidine has been proven to be of some value in reducing VAP, although may be more effective when used with a solution which targets gram-negative bacteria. Tooth-brushing is recommended in providing a higher standard of oral care to mechanically ventilated patients and reducing VAP when used with chlorhexidine. However, limitations in study design and inconsistency in results suggest that further research is required into the effects of tooth-brushing. © 2011 The Authors. Nursing in Critical Care © 2011 British Association of Critical Care Nurses.

21 CFR 556.120 - Chlorhexidine.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.120 Chlorhexidine. A tolerance of zero is established for residues of...

21 CFR 556.120 - Chlorhexidine.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.120 Chlorhexidine. A tolerance of zero is established for residues of...

21 CFR 556.120 - Chlorhexidine.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.120 Chlorhexidine. A tolerance of zero is established for residues of...

21 CFR 556.120 - Chlorhexidine.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.120 Chlorhexidine. A tolerance of zero is established for residues of...

21 CFR 556.120 - Chlorhexidine.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.120 Chlorhexidine. A tolerance of zero is established for residues of...

Chlorhexidine droplet splash from a skin preparation gallipot: effect of height of pouring.

PubMed

Evans, L; Cunningham, M; Tilakaratna, P

2013-12-01

Chlorhexidine contamination of equipment used in central neuraxial anaesthesia has been implicated in causing adhesive arachnoiditis. We measured the extent of chlorhexidine splash during pouring into a gallipot (antiseptic skin preparation container) from heights of 5 cm, 10 cm, 15 cm and 20 cm. Twenty experiments were performed at each height. Measurements made up to a horizontal distance of 40 cm radius from the gallipot showed a median (IQR [range]) maximum spread of splash droplets ≥ 2 mm diameter of 26.2 (10.2-36.4 [0-40]) cm. The 40-cm radius measurement area was divided into 5-cm-wide zones to assess spread. At pouring heights of 15 cm and 20 cm, all zones were contaminated. These results demonstrate that pouring chlorhexidine into a gallipot generates significant splash, and we recommend that this should be avoided near equipment used for neuraxial anaesthesia. © 2013 The Association of Anaesthetists of Great Britain and Ireland.

Cholorhexidine, octenidine or povidone iodine for catheter related infections: A randomized controlled trial

PubMed Central

Bilir, Ayten; Yelken, Birgül; Erkan, Ayse

2013-01-01

Background: Protection of the catheter site by antimicrobial agents is one of the most important factors in the prevention of infection. Povidone iodine and chlorhexidine gluconate are the most common used agents for dressing. The purpose of this study was to compare the effects of povidone iodine, chlorhexidine gluconate and octenidine hydrochloride in preventing catheter related infections. Materials and Methods: Patients were randomized to receive; 4% chlorhexidine gluconate, 10% povidone iodine or octenidine hydrochlorodine for cutaneous antisepsis. Cultures were taken at the site surrounding catheter insertion and at the catheter hub after removal to help identify the source of microorganisms. Results: Catheter related sepsis was 10.5% in the povidone iodine and octenidine hydrochlorodine groups. Catheter related colonization was 26.3% in povidone iodine group and 21.5% in octenidine hydrochlorodine group. Conclusion: 4% chlorhexidine or octenidine hydrochlorodine for cutaneous disinfection before insertion of an intravascular device and for post-insertion site care can reduce the catheter related colonization. PMID:24250702

Antimicrobial effects of essential oils in combination with chlorhexidine digluconate.

PubMed

Filoche, S K; Soma, K; Sissons, C H

2005-08-01

The aim of the present study was to compare antimicrobial effects of essential oils alone and in combination with chlorhexidine digluconate against planktonic and biofilm cultures of Streptococcus mutans and Lactobacillus plantarum. The essential oils included cinnamon, tea-tree (Melaleuca alternifola), manuka (Leptospermum scoparium), Leptospermum morrisonii, arnica, eucalyptus, grapefruit, the essential oil mouthrinse Cool Mint Listerine and two of its components, menthol and thymol. Cinnamon exhibited the greatest antimicrobial potency (1.25-2.5 mg/ml). Manuka, L. morrisonii, tea-tree oils, and thymol also showed antimicrobial potency but to a lesser extent. The combination effect of the essential oil-chlorhexidine was greater against biofilm cultures of both S. mutans and L. plantarum than against planktonic cultures. The amount of chlorhexidine required to achieve an equivalent growth inhibition against the biofilm cultures was reduced 4-10-fold in combination with cinnamon, manuka, L. morrisonii, thymol, and Listerine. We conclude that there may be a role for essential oils in the development of novel anticaries treatments.

[Prospective randomized study regarding the effect of the preoperative antibiotic and chlorhexidine rinse on wound healing after mandibular third molar surgery].

PubMed

Kaposvári, István; Körmöczi, Kinga; László, Zsuzsa Beáta; Oberna, Ferenc; Horváth, Ferenc; Joób-Fancsaly, Árpád

2017-01-01

The study compares the antibiotic prophylaxis combined with postoperative antibiotic therapy to preoperative chlorhexidine rinse combined with postoperative antibiotic therapy in preventing complications after surgical removal of a mandibular third molar. 71 healthy patients in four groups were enrolled in the study: I. prophylactic dose of 2000 mg of amoxicillin clavulanate, continued with amoxicillin clavulanate postoperatively; II. prophylactic dose of 600 mg of clindamycin, continued with clindamycin postoperatively; III. prophylactic chlorhexidin rinsing, continued randomized amoxicillin clavulanate or clindamycin postoperatively; IV. control, with clindamycin postoperatively. The pain was smaller in the prophylaxis groups. Alveolitis occurred only in the control group: 2 patients. Wound opening occurred in 22,2 % in group IV., 14,2 % in group II, 10 % in group I., 5 % in group III. We consider completing the indicated postoperative antibiotic prescription with antibiotic or antiseptic prophylaxis. Chlorhexidin prophylaxis could have the same positive effect. Orv. Hetil., 2017, 158(1), 13-19.

Serratia marcescens outbreak due to contaminated 2% aqueous chlorhexidine.

PubMed

de Frutos, Mónica; López-Urrutia, Luis; Domínguez-Gil, Marta; Arias, Marta; Muñoz-Bellido, Juan Luis; Eiros, José María; Ramos, Carmen

2017-12-01

An outbreak of Serratia marcescens infections outbreak is described, as well as the epidemiological study that linked the outbreak to the use of 2% aqueous chlorhexidine antiseptic. In late November 2014 an increasing incidence of S. marcescens isolates was detected in patients treated in the emergency department. It was considered a possible outbreak, and an epidemiological investigation was started. S. marcescens was isolated in 23 samples from 16 patients and in all new bottles of two lots of 2% aqueous chlorhexidine. The contaminated disinfectant was withdrawn, and the Spanish Drugs Agency was alerted (COS 2/2014). The epidemiological study showed that strains isolated from clinical samples and from chlorhexidine belonged to the same clone. No further isolates were obtained once the disinfectant was withdrawn. The suspicion of an outbreak and the epidemiological study were essential to control the incidence. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Topical applications of chlorhexidine to the umbilical cord for prevention of omphalitis and neonatal mortality in southern Nepal: a community-based, cluster-randomised trial

PubMed Central

Mullany, Luke C; Darmstadt, Gary L; Khatry, Subarna K; Katz, Joanne; LeClerq, Steven C; Shrestha, Shardaram; Adhikari, Ramesh; Tielsch, James M

2008-01-01

Summary Background Omphalitis contributes to neonatal morbidity and mortality in developing countries. Umbilical cord cleansing with antiseptics might reduce infection and mortality risk, but has not been rigorously investigated. Methods In our community-based, cluster-randomised trial, 413 communities in Sarlahi, Nepal, were randomly assigned to one of three cord-care regimens. 4934 infants were assigned to 4·0% chlorhexidine, 5107 to cleansing with soap and water, and 5082 to dry cord care. In intervention clusters, the newborn cord was cleansed in the home on days 1−4, 6, 8, and 10. In all clusters, the cord was examined for signs of infection (pus, redness, or swelling) on these visits and in follow-up visits on days 12, 14, 21, and 28. Incidence of omphalitis was defined under three sign-based algorithms, with increasing severity. Infant vital status was recorded for 28 completed days. The primary outcomes were incidence of neonatal omphalitis and neonatal mortality. Analysis was by intention-to-treat. This trial is registered with Clinicaltrials.gov, number NCT00109616. Findings Frequency of omphalitis by all three definitions was reduced significantly in the chlorhexidine group. Severe omphalitis in chlorhexidine clusters was reduced by 75% (incidence rate ratio 0·25, 95% CI 0·12−0·53; 13 infections/4839 neonatal periods) compared with dry cord-care clusters (52/4930). Neonatal mortality was 24% lower in the chlorhexidine group (relative risk 0·76 [95% CI 0·55−1·04]) than in the dry cord care group. In infants enrolled within the first 24 h, mortality was significantly reduced by 34% in the chlorhexidine group (0·66 [0·46−0·95]). Soap and water did not reduce infection or mortality risk. Interpretation Recommendations for dry cord care should be reconsidered on the basis of these findings that early antisepsis with chlorhexidine of the umbilical cord reduces local cord infections and overall neonatal mortality. PMID:16546539

Susceptibility in vitro of canine methicillin-resistant and -susceptible staphylococcal isolates to fusidic acid, chlorhexidine and miconazole: opportunities for topical therapy of canine superficial pyoderma.

PubMed

Clark, S M; Loeffler, A; Bond, R

2015-07-01

Increasing multidrug resistance amongst canine pathogenic staphylococci has renewed interest in topical antibacterial therapy for skin infections in the context of responsible veterinary prescribing. We therefore determined the activity in vitro of three clinically relevant topical agents and synergism between two of them against Staphylococcus pseudintermedius and Staphylococcus aureus. The MICs of fusidic acid (n = 199), chlorhexidine (n = 198), miconazole (n = 198) and a 1:1 combination of miconazole/chlorhexidine (n = 198) were determined for canine isolates [50 MRSA and 49 methicillin-resistant S. pseudintermedius (MRSP), 50 MSSA and 50 methicillin-susceptible S. pseudintermedius (MSSP)] collected from the UK and Germany using an agar dilution method (CLSI VET01-A4). Fractional inhibitory concentration (FIC) indices were calculated to assess the interaction of miconazole with chlorhexidine. MICs of each drug/combination were significantly (P < 0.0005) higher for S. aureus when compared with S. pseudintermedius. Most strains (n = 172) had an MIC of fusidic acid of ≤0.03 mg/L (MIC ≥64 mg/L, n = 5 MRSA). All strains had MICs of chlorhexidine of 0.5-4 mg/L, except for one MRSA (MIC = 8 mg/L). All but four strains had MICs of miconazole of 1-4 mg/L (MIC = 16 mg/L, n = 3; MIC = 256 mg/L, n = 1). Miconazole/chlorhexidine (1:1 ratio) had a synergistic effect against 49/50 MRSA, 31/50 MSSA, 12/49 MRSP and 23/49 MSSP. Since the majority of these staphylococci, including methicillin-resistant isolates, had MICs that should be readily exceeded by topical skin application of these agents, their therapeutic efficacy for canine superficial pyoderma should be assessed. The synergistic interaction shown in vitro supports further clinical evaluation of miconazole/chlorhexidine combination therapy for staphylococcal infection. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

The effectiveness of a preprocedural mouthrinse containing cetylpyridinium chloride in reducing bacteria in the dental office.

PubMed

Feres, Magda; Figueiredo, Luciene Cristina; Faveri, Marcelo; Stewart, Bernal; de Vizio, William

2010-04-01

During oral procedures, microorganisms from the oral cavity may contaminate nearby surfaces. The authors evaluated the efficacy of a commercial preprocedural mouthrinse containing 0.05 percent cetylpyridinium chloride (CPC) in reducing the levels and composition of viable bacteria in oral spatter. The authors randomly assigned 60 participants receiving oral prophylaxis with an ultrasonic scaler to one of four groups: a preprocedural rinse solution containing 0.05 percent CPC, 0.12 percent chlorhexidine (CHX) or water, or no rinsing. Airborne microorganisms were collected on blood agar plates. The composition of the spatter was analyzed for 39 oral bacterial species by means of checkerboard DNA-DNA hybridization. CPC and CHX were equally effective in lowering the levels of spatter bacteria and performed better than water and no rinsing (P < .05, Kruskal-Wallis test). The composition of the spatter from the control groups showed higher proportions (P < .05, Kruskal-Wallis test) of Fusobacterium species and lower proportions of Capnocytophaga species when compared with the spatter from the CPC and CHX groups. A commercial mouthrinse containing 0.05 percent CPC when used as a preprocedural mouthrinse was equally effective as CHX in reducing the levels of spatter bacteria generated during ultrasonic scaling. Owing to its strong antibacterial effect and the fact that it has fewer side effects than CHX, a solution containing 0.05 percent CPC may be a good alternative to that containing 0.12 CHX as a preprocedural mouthrinse used to help decrease the level of contamination in spatter.

Third-degree burns caused by ignition of chlorhexidine: A case report and systematic review of the literature

PubMed Central

Vo, Anthony; Bengezi, Omar

2014-01-01

Ignition of chlorhexidine by an electrocautery unit is rare but can have devastating consequences for the patient and the surgeon. A case involving a 77-year-old man who underwent removal of an indwelling artificial urethral sphincter is presented. The chlorhexidine was ignited when the urologist activated the electrocautery unit, causing third-degree burns to the patient. A plastic surgeon treated the burns with surgical debridement and split-thickness skin grafting. A systematic review of the literature was performed with best practice recommendations. To the authors’ knowledge, the present case is the ninth such case reported. PMID:25535466

Antimicrobial efficacy of an innovative emulsion of medium chain triglycerides against canine and feline periodontopathogens.

PubMed

Laverty, G; Gilmore, B F; Jones, D S; Coyle, L; Folan, M; Breathnach, R

2015-04-01

To test the in vitro antimicrobial efficacy of a non-toxic emulsion of free fatty acids against clinically relevant canine and feline periodontopathogens Antimicrobial kill kinetics were established utilising an alamarBlue(®) viability assay against 10 species of canine and feline periodontopathogens in the biofilm mode of growth at a concentration of 0·125% v/v medium chain triglyceride (ML:8) emulsion. The results were compared with 0·12% v/v chlorhexidine digluconate and a xylitol-containing dental formulation. Mammalian cellular cytotoxicity was also investigated for both the ML:8 emulsion and chlorhexidine digluconate (0·25 to 0·0625% v/v) using in vitro tissue culture techniques. No statistically significant difference was observed in the antimicrobial activity of the ML:8 emulsion and chlorhexidine digluconate; a high percentage kill rate (>70%) was achieved within 5 minutes of exposure and was maintained at subsequent time points. A statistically significant improvement in antibiofilm activity was observed with the ML:8 emulsion compared with the xylitol-containing formulation. The ML:8 emulsion possessed a significantly lower (P < 0·001) toxicity profile compared with the chlorhexidine digluconate in mammalian cellular cytotoxicity assays. The ML:8 emulsion exhibited significant potential as a putative effective antimicrobial alternative to chlorhexidine- and xylitol- based products for the reduction of canine and feline periodontopathogens. © 2015 British Small Animal Veterinary Association.

In vitro susceptibility of gram-negative bacterial isolates to chlorhexidine gluconate.

PubMed

Mengistu, Y; Erge, W; Bellete, B

1999-05-01

To investigate the susceptibility of clinical isolates of gram-negative bacteria to chlorhexidine gluconate. Prospective laboratory study. Tikur Anbessa Hospital, Addis Ababa, Ethiopia. Clinical specimens from 443 hospital patients. Significant number of gram negative bacteria were not inhibited by chlorhexidine gluconate (0.02-0.05%) used for antisepsis. Four hundred and forty three strains of gram-negative bacteria were isolated from Tikur Anbessa Hospital patients. Escherichia coli (31.6%) and Klebsiella pneumoniae (23%) were the most frequently isolated bacteria followed by Proteus species (13.3%), Pseudomonas species (9.2%), and Citrobacter species (6.1%). Each organism was tested to chlorhexidine gluconate (CHG), minimum inhibitory concentration (MIC) ranging from 0.0001% to 1%w/v. All Salmonella species and E. coli were inhibited by CHG, MIC < or = 0.01%. Twenty nine per cent of Acinetobacter, 28% of K. pneumoniae and Enterobacter species and 19-25% of Pseudomonas, Proteus and Providencia species were only inhibited at high concentrations of CHG (> or = 0.1%). Our results showed that a significant number of the gram-negative bacterial isolates were not inhibited by CHG at the concentration used for disinfection of wounds or instruments (MIC 0.02-0.05% w/v). It is therefore important to select appropriate concentration of this disinfectant and rationally use it for disinfection and hospital hygiene. Continuing follow up and surveillance is also needed to detect resistant bacteria to chlorhexidine or other disinfectants in time.

Effects of intra-alveolar placement of 0.2% chlorhexidine bioadhesive gel on dry socket incidence and postsurgical pain: a double-blind split-mouth randomized controlled clinical trial.

PubMed

Haraji, Afshin; Rakhshan, Vahid; Khamverdi, Naiemeh; Alishahi, Hadiseh Khanzadeh

2013-01-01

To assess the effects of intra-alveolar application of chlorhexidine gel on the incidence of alveolar osteitis (dry socket) and the severity of postsurgical pain. A total of 160 impacted mandibular third molars were extracted in 80 patients enrolled in this trial. In each subject, a socket was randomly selected and packed to the crest of the alveolar ridge with a gelatin sponge dressing saturated in 0.2% chlorhexidine gel. The contralateral socket was packed with a dry dressing as the placebo. None of the included patients took antibiotics or analgesics. The occurrence of dry socket and patients' pain levels were assessed at the first and third postoperative days. The data were analyzed using Spearman correlation coefficient, McNemar, Wilcoxon, and chi-square tests. Chlorhexidine gel significantly reduced dry socket incidence from 32.6% to 11.3% (P ≤ .001 [McNemar and chi-square], absolute risk reduction = 21.2%, relative risk reduction = 65.4%, odds ratio = 0.263, relative risk = 0.345). It also significantly relieved postoperative pain on both sides in all the patients (P ≤ .001 [Wilcoxon]) and also in the 54 subjects who did not develop dry socket (P ≤ .001 [Wilcoxon]). Besides decreasing the incidence of dry socket, chlorhexidine gel can reduce postsurgical pain in patients with and without dry socket.

Comparison of Antimicrobial Activity of Chlorhexidine, Coconut Oil, Probiotics, and Ketoconazole on Candida albicans Isolated in Children with Early Childhood Caries: An In Vitro Study

PubMed Central

Ahmed Bijapur, Gufran; Kottayi, Soni; Jose, Deepak

2016-01-01

Background. Early childhood caries (ECC) is associated with early colonisation and high levels of cariogenic microorganisms. With C. albicans being one of those, there is a need to determine the effectiveness of various chemotherapeutic agents against it. The study is aimed at isolating Candida species in children with ECC and at studying the antifungal effect of coconut oil, probiotics, Lactobacillus, and 0.2% chlorhexidine on C. albicans in comparison with ketoconazole. Materials and Methods. Samples were collected using sterile cotton swabs, swabbed on the tooth surfaces from children with ECC of 3 to 6 yrs and streaked on Sabouraud dextrose agar (HI Media) plates and incubated in a 5% CO2 enriched atmosphere at 37°C for 24 hours. Candida was isolated and its susceptibility to probiotics, chlorhexidine, ketoconazole, and coconut oil was determined using Disc Diffusion method. Results. The mean zone of inhibition for chlorhexidine was 21.8 mm, whereas for coconut oil it was 16.8 mm, for probiotics it was 13.5 mm, and for ketoconazole it was 22.3 mm. The difference between the groups was not statistically significant (Chi-square value 7.42, P value 0.06). Conclusion. Chlorhexidine and coconut oil have shown significant antifungal activity which is comparable with ketoconazole. PMID:27051559

A randomized clinical trial of chlorhexidine in the maintenance of oral candidiasis-free period in HIV infection

PubMed Central

Nittayananta, W; DeRouen, TA; Arirachakaran, P; Laothumthut, T; Pangsomboon, K; Petsantad, S; Vuddhakul, V; Sriplung, H; Jaruratanasirikul, S; Martin, MD

2011-01-01

OBJECTIVE To determine if chlorhexidine can be used as an intervention to prolong the time to relapse of oral candidiasis. SUBJECTS AND METHODS A double-blinded randomized clinical trial was performed in 75 HIV/AIDS subjects with oral candidiasis. Clotrimazole troche was prescribed, and the subjects were re-examined every 2 weeks until the lesions were completely eradicated. The subjects were then randomly divided into two groups; 0.12% chlorhexidine (n = 37, aged 22–52 years, mean 34 years) and 0.9% normal saline (n = 38, aged 22–55 years, mean 38 years). They were re-examined every 2 weeks until the next episode was observed. RESULTS The time to recurrence of oral candidiasis between the chlorhexidine and the saline group was not statistically significant (P > 0.05). The following variables were significantly associated with the time of recurrence; frequency of antifungal therapy (P = 0.011), total lymphocyte (P = 0.017), alcohol consumption (P = 0.043), and candidiasis on gingiva (P = 0.048). The subjects with lower lymphocyte showed shorter oral candidiasis-free periods (P = 0.034). CONCLUSIONS Chlorhexidine showed a small but not statistically significant effect in maintenance of oral candidiasis-free period. This lack of significance may be due to the small sample size. Further study should be performed to better assess the size of the effect, or to confirm our findings. PMID:18627504

The potential pathogenicity of chlorhexidine-sensitive Acanthamoeba strains isolated from contact lens cases from asymptomatic individuals in Tenerife, Canary Islands, Spain.

PubMed

Martín-Navarro, Carmen M; Lorenzo-Morales, Jacob; Cabrera-Serra, M Gabriela; Rancel, Fernando; Coronado-Alvarez, Nieves M; Piñero, José E; Valladares, Basilio

2008-11-01

Pathogenic strains of the genus Acanthamoeba are causative agents of a serious sight-threatening infection of the eye known as Acanthamoeba keratitis. The prevalence of this infection has risen in the past 20 years, mainly due to the increase in number of contact lens wearers. In this study, the prevalence of Acanthamoeba in a risk group constituted by asymptomatic contact lens wearers from Tenerife, Canary Islands, Spain, was evaluated. Contact lenses and contact lens cases were analysed for the presence of Acanthamoeba isolates. The isolates' genotypes were also determined after rDNA sequencing. The pathogenic potential of the isolated strains was subsequently established using previously described molecular and biochemical assays, which allowed the selection of three strains with high pathogenic potential. Furthermore, the sensitivity of these isolates against two standard drugs, ciprofloxacin and chlorhexidine, was analysed. As the three selected strains were sensitive to chlorhexidine, its activity and IC(50) were evaluated. Chlorhexidine was found to be active against these strains and the obtained IC(50) values were compared to the concentrations of this drug present in contact lens maintenance solutions. It was observed that the measured IC(50) was higher than the concentration found in these maintenance solutions. Therefore, the ineffectiveness of chlorhexidine-containing contact lens maintenance solutions against potentially pathogenic strains of Acanthamoeba is demonstrated in this study.

Comparative evaluation of compressive strength, diametral tensile strength and shear bond strength of GIC type IX, chlorhexidine-incorporated GIC and triclosan-incorporated GIC: An in vitro study.

PubMed

Jaidka, Shipra; Somani, Rani; Singh, Deepti J; Shafat, Shazia

2016-04-01

To comparatively evaluate the compressive strength, diametral tensile strength, and shear bond strength of glass ionomer cement type IX, chlorhexidine-incorporated glass ionomer cement, and triclosan-incorporated glass ionomer cement. In this study, glass ionomer cement type IX was used as a control. Chlorhexidine diacetate, and triclosan were added to glass ionomer cement type IX powder, respectively, in order to obtain 0.5, 1.25, and 2.5% concentrations of the respective experimental groups. Compressive strength, diametral tensile strength, and shear bond strength were evaluated after 24 h using Instron Universal Testing Machine. The results obtained were statistically analyzed using the independent t-test, Dunnett test, and Tukey test. There was no statistical difference in the compressive strength, diametral tensile strength, and shear bond strength of glass ionomer cement type IX (control), 0.5% triclosan-glass ionomer cement, and 0.5% chlorhexidine-glass ionomer cement. The present study suggests that the compressive strength, diametral tensile strength, and shear bond strength of 0.5% triclosan-glass ionomer cement and 0.5% chlorhexidine-glass ionomer cement were similar to those of the glass ionomer cement type IX, discernibly signifying that these can be considered as viable options for use in pediatric dentistry with the additional value of antimicrobial property along with physical properties within the higher acceptable range.

Effect of Two Herbal Mouthwashes on Gingival Health of School Children

PubMed Central

Sharma, Ratika; Hebbal, Mamata; Ankola, Anil V.; Murugaboopathy, Vikneshan; Shetty, Sindhu Jayasimha

2014-01-01

This study aimed at determining the effect of indigenously prepared neem and mango chewing stick mouthwashes on plaque and gingival indices. A sample of 105 children aged 12-15 years was randomized into three groups, namely neem, mango, and chlorhexidine mouthwash groups. All the children were examined at baseline and gingival and plaque indices were recorded. Baseline scores for plaque and gingivitis were fair and moderate, respectively, in all the three groups and there existed no statistically significant difference among them. Ten millilitres each of herbal and chlorhexidine mouthwashes (0.2%) were administered according to the group allocation twice daily for 21 days. Indices were reassessed at 21 days (immediately after intervention) and at 1 month, 2 months, and 3 months after discontinuing the mouthwashes. Statistically significant reduction (P < 0.001) in plaque index was found in all the three mouthwash groups at 21 days and at 1 month from discontinuing the mouthwash. Chlorhexidine additionally showed statistically significant reduction in plaque index at 2 months from discontinuing the mouthwash. Statistically significant reduction (P < 0.001) in gingival index was found in all the three mouthwash groups at 21 days (immediately after discontinuing the mouthwash) and at 1 and 2 months from discontinuing the mouthwash. To conclude, all the three mouthwashes were effective antiplaque and antigingivitis agents. Chlorhexidine and neem possess equivalent efficacy in reducing plaque, while chlorhexidine has superior antigingivitis properties. PMID:25379471

The Efficacy of Calcium Hydroxide Powder mixed with 0.2% Chlorhexidine Digluconate or mixed with Normal Saline as Intracanal Medicament in the Treatment of Apical Periodontitis.

PubMed

Menakaya, Ifeoma N; Adegbulugbe, Ilemobade C; Oderinu, Olabisi H; Shaba, Olufemi P

2015-08-01

To compare the efficacy of calcium hydroxide powder mixed with 0.2% chlorhexidine digluconate or mixed with normal saline as intracanal medicament in the treatment of apical periodontitis. Subjects were 55 in number aged 17 to 60 years. Two-visit conventional root canal treatment was performed on 70 teeth. The teeth were divided by randomization (balloting) into two groups: control group and experimental group, each with 35 teeth treated with calcium hydroxide mixed with normal saline or with 0.2% chlorhexidine digluconate as intracanal medicament respectively. All treated teeth were evaluated clinically and radiographically for signs and symptom of periapical infection at specified periods postoperatively. Overall efficacy of medicament was rated based on quality guidelines for endodontic treatment by the European Society of Endodontology 2006. A postoperative favorable outcome of 97.1% in the control group and 94.3% in the experimental group was observed at 6-month review. This difference was not statistically significant (p > 0.05). The use of normal saline or 0.2% chlorhexidine digluconate to mix calcium hydroxide used as intracanal medicament during endodontic treatment resulted in high postoperative favorable outcomes. Efficacy of 0.2% chlorhexidine digluconate as a vehicle for mixing calcium hydroxide as an intracanal medicament in the treatment of apical periodontitis is comparable to the efficacy of calcium hydroxide mixed with normal saline.

Effect of Two Traditional Polyacrylic Acid Conditioners and 2% Chlorhexidine Digluconate on Cavosurface Microleakage of Glass Ionomer Restorations.

PubMed

Lugassy, Diva; Segal, Pnina; Blumer, Sigalit; Eger, Michal; Shely, Asaf; Matalon, Shlomo

2018-05-11

A lack of appropriate adhesiveness is one of the biggest problems in restorative dentistry today and the main cause of microleakage. This is especially true in pediatric dentistry where moisture control is more difficult to achieve. Glass ionomer restorative materials increase adhesion and decrease microleakage given their chemical adhesion to the remaining tooth substance. Pretreatment improves the adhesion quality. The aim of this study was to assess the microleakage of Glass ionomer restorative materials following application of 20% polyacrylic acid, 10% polyacrylic acid or 2% chlorhexidine digluconate in Class V cavities. Two Class V preparations were prepared on the buccal and lingual surfaces of 24 extracted human molars. The gingival wall was set below or above the CEJ. The teeth were divided into 2 groups. Group 1 was treated with 20% polyacrylic acid or 10% polyacrylic acid. Group 2 was treated with 10% polyacrylic acid or 2% chlorhexidine digluconate. Microleakage was evaluated using a light-reflecting stereomicroscope and stain penetration test. Two percent chlorhexidine digluconate was as efficient as the other conditioners. No statistically significant differences were found among the three types of conditioners. Dye penetration was significantly greater into dentin than into enamel among all three conditioners in both groups (P<0.001). Two percent chlorhexidine digluconate, with its known added advantages, can be used as a pretreatment conditioner in GI restorations.

Chlorhexidine mouthwash plaque levels and gingival health.

PubMed

Richards, Derek

2017-06-23

Data sourcesCochrane Oral Health's Trials Register; Cochrane Central Register of Controlled Trials (CENTRAL) Medline; clinicaltrials.gov and the World Health Organization International Clinical Trials Registry Platform. There were no language or date restrictions on searches.Study selectionRandomised controlled trials (RCTs) assessing the effects of chlorhexidine mouthrinse used as an adjunct to mechanical oral hygiene procedures for at least four weeks on gingivitis in children and adults.Data extraction and synthesisTwo reviewers independently abstracted data and assessed risk of bias. Mean and standardised mean differences were used for continuous outcomes and risk ratios for dichotomous outcomes. Meta-analysis was carried out where studies of similar comparisons reported the same outcomes at the same time interval.ResultsFifty-one RCTs involving a total of 5,345 patients were included. Only one study was at low risk of bias, the other 50 were at high risk. For patients with mild gingivitis (gingival index [GI] 0 to 3 scale) four to six weeks' use of chlorhexidine mouthrinse reduced gingivitis by 0.21 (95% CI; 0.11 to 0.31) with a similar effect at six months. There were insufficient data to assess the effect on patients with moderate or severe gingival inflammation. For plaque there was a larger effect in favour of chlorhexidine mouthrinse at four to six weeks, SMD (standardised mean difference) = -1.45 (95% CI; -1.90 to -1.00), with a similarly large reduction at six months. A large increase in extrinsic tooth staining was seen with chlorhexidine use at four to six weeks, SMD = 1.07 (95%CI; 0.80 to 1.34) and seven to twelve weeks and six months. A range of other adverse effects were reported including taste disturbance/alteration, oral mucosa symptoms including soreness, irritation, mild desquamation and mucosal ulceration/erosions, and a general burning sensation or a burning tongue or both.ConclusionsThere is high quality evidence from studies that reported the Löe and Silness Gingival Index of a reduction in gingivitis in individuals with mild gingival inflammation on average (mean score of 1 on the 0 to 3 GI scale) that was not considered to be clinically relevant. There is high quality evidence of a large reduction in dental plaque with chlorhexidine mouthrinse used as an adjunct to mechanical oral hygiene procedures for four to six weeks and six months. There is no evidence that one concentration of chlorhexidine rinse is more effective than another. There is insufficient evidence to determine the reduction in gingivitis associated with chlorhexidine mouthrinse use in individuals with mean GI scores of 1.1 to 3 indicating moderate or severe levels of gingival inflammation. Rinsing with chlorhexidine mouthrinse for four weeks or longer causes extrinsic tooth staining. In addition, other adverse effects such as calculus build up, transient taste disturbance and effects on the oral mucosa were reported in the included studies.

Intrinsic Klebsiella pneumoniae contamination of liquid germicidal hand soap containing chlorhexidine.

PubMed

Brooks, Steven E; Walczak, Mary A; Malcolm, Sharon; Hameed, Rizwanullah

2004-10-01

We describe intrinsic contamination with Klebsiella pneumoniae occurring during the manufacture of germicidal hand soap, labeled as containing 2% chlorhexidine, used throughout a 350-bed community medical center. A 3-year retrospective study failed to find evidence of increased incidence of clinical isolates of this strain.

Prevention and treatment of dry socket.

PubMed

Dodson, Tom

2013-03-01

Cochrane Oral Health Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase databases were searched together with reference lists of identified articles. Topic experts and organisations were also contacted. Only randomised controlled trials were considered and there were no restrictions regarding language or date of publication. Data abstraction and risk of bias assessment were conducted in duplicate and Cochrane statistical guidelines were followed. The GRADE tool was used to assess the quality of the body of evidence. Twenty-one trials with 2570 participants were included. Eighteen trials (2376 participants) related to prevention and three to treatment (194 participants). Six studies were at high risk of bias, 14 of unclear risk and one study at low risk. There was moderate evidence (four trials, 750 participants) that chlorhexidine mouthrinses (0.12% and 0.2% concentrations) both before and after extraction(s) prevented approximately 42% of dry socket(s) with a RR of 0.58 (95% CI 0.43 to 0.78; P < 0.001). The number of patients needed to be treated (0.12% and 0.2%) with chlorhexidine rinse to prevent one patient having dry socket (NNT) was 232 (95% CI 176 to 417), 47 (95% CI 35 to 84) and 8 (95% CI 6 to 14) at prevalences of dry socket of 1%, 5% and 30% respectively. Thee was moderate evidence (two trials, in 133 participants) that placing chlorhexidine gel (0.2%) after extractions prevented approximately 58% of dry socket(s) with a RR of 0.42 (95% CI 0.21 to 0.87; P = 0.02) with NNT of 173 (95% CI 127 to 770), 35 (95% CI 25 to 154) and 6 (95% CI 5 to 26) at prevalences of dry socket of 1%, 5% and 30% respectively. There was insufficient evidence to determine the effects of other intrasocket preventive interventions or interventions to treat dry socket. There is some evidence that rinsing with chlorhexidine (0.12% and 0.2%) or placing chlorhexidine gel (0.2%) in the sockets of extracted teeth, provides a benefit in preventing dry socket. There was insufficient evidence to determine the effects of the other 10 preventative interventions each evaluated in single studies. There was insufficient evidence to determine the effects of any of the interventions to treat dry socket. The present review found some evidence for the association of minor adverse reactions with use of 0.12%, 0.2% and 2% chlorhexidine mouthrinses, though most studies were not designed to detect the presence of hypersensitivity reactions to mouthwash as part of the study protocol. No adverse events were reported in relation to the use of 0.2% chlorhexidine gel placed directly into a socket (though previous allergy to chlorhexidine was an exclusion criterion in these trials). In view of recent reports in the UK of two cases of serious adverse events associated with irrigation of dry socket with chlorhexidine mouthrinse, it is recommended that all members of the dental team prescribing chlorhexidine products are aware of the potential for both minor and serious adverse side effects. It is beyond the scope of this review to describe and detail The Cochrane Collaboration. The reader can seek out more information at http://www.cochrane.org/. In brief, a systematic review supported and published by the Cochrane group represents the gold standard to support clinical decision-making.

Antagonistic interactions amongst bacteriocin-producing enteric bacteria in dual species biofilms.

PubMed

Tait, K; Sutherland, I W

2002-01-01

The objective of this study was to investigate the antagonistic interactions between bacteriocin-producing enteric bacteria in dual species biofilms and the interspecies interactions correlated with sensitivity to biocides. When compared with their single species counterparts, the dual species biofilms formed by bacteriocin-producing strains exhibited a decrease in biofilm size and an increase in sensitivity to the antimicrobial agents hypochlorite, triclosan and benzalkonium chloride. The five dual species biofilms studied all resulted in biofilms containing a mixture of the two strains. This was attributed to the spatial distribution of cells within the biofilm, with each strain forming its own microcolonies. The production of a bacteriocin also gave a strain a competitive advantage when interacting with a bacteriocin-sensitive strain within a biofilm, both in gaining a foothold in a new environment and in preventing the colonization of a potential competitor into a pre-established biofilm. It was concluded that bacteriocins might be used specifically for interacting with competing strains within a biofilm, as opposed to a planktonic, environment. Unlike planktonically grown bacteriocin-producing populations, where one strain will always be out-competed, bacteriocin-producing and bacteriocin-sensitive strains can coexist in biofilm communities, clearly demonstrating major differences between biofilm and planktonic competition. This paper highlights the importance of bacteriocin production in the development of biofilm communities.

The Influence of Interfering Substances on the Antimicrobial Activity of Selected Quaternary Ammonium Compounds

PubMed Central

Araújo, Paula A.; Lemos, Madalena; Mergulhão, Filipe; Melo, Luís; Simões, Manuel

2013-01-01

Standard cleaning processes may not remove all the soiling typically found in food industry, such as carbohydrates, fats, or proteins. Contaminants have a high impact in disinfection as their presence may reduce the activity of disinfectants. The influence of alginic acid, bovine serum albumin, yeast extract, and humic acids was assessed on the antimicrobial activities of benzalkonium chloride and cetyltrimethyl ammonium bromide against Bacillus cereus vegetative cells and Pseudomonas fluorescens. The bacteria (single and consortium) were exposed to surfactants (single and combined) in the absence and presence of potential disinfection interfering substances. The antimicrobial effects of the surfactants were assessed based on the bacterial respiratory activity measured by oxygen uptake rate due to glucose oxidation. The tested surfactants were efficient against both bacteria (single and consortium) with minimum bactericidal concentrations ranging from 3 to 35 mg·L−1. The strongest effect was caused by humic acids that severely quenched antimicrobial action, increasing the minimum bactericidal concentration of the surfactants on P. fluorescens and the consortium. The inclusion of the other interfering substances resulted in mild interferences in the antibacterial activity. This study clearly demonstrates that humic acids should be considered as an antimicrobial interfering substance in the development of disinfection strategies. PMID:26904590

Occupational dermatitis in health care workers evaluated for suspected allergic contact dermatitis.

PubMed

Kadivar, Salmon; Belsito, Donald V

2015-01-01

Contact dermatitides occur commonly among health care workers (HCWs). To contrast the atopic status and incidence, location, and final diagnosis of skin diseases afflicting HCWs versus non-HCWs (NHCWs) evaluated for suspicion of allergic contact dermatitis (ACD); and among the population diagnosed with ACD, to compare the incidence and occupational relatedness of allergens found in HCWs with the rates observed in NHCWs. Between July 1, 1994, and May 30, 2014, 2611 patients underwent patch testing by the senior author. Of these, 165 were classified as HCWs based on their primary occupation. Statistical analysis was done using a χ test. Health care workers were more likely than NHCWs to be women and to have hand dermatitis. Women, but not men, HCWs suffered more irritant contact dermatitis. Health care workers had significantly more work-related ACD, especially to formaldehyde, quaternium-15, 2-bromo-2-nitropropane-1,3-diol, cocamide diethanolamine (DEA), thiuram mix, carba mix, thimerosal, benzalkonium chloride, glutaraldehyde, and bacitracin. Only patients suspected of having ACD were tested. Our population was geographically limited to metropolitan Kansas City, MO and metropolitan New York, NY. Health care workers suffer more from occupational ACD, especially of the hands, than do NHCWs, including to allergens not present on available standard allergen series.

The Effect of Dry Eye Disease on Scar Formation in Rabbit Glaucoma Filtration Surgery

PubMed Central

Ji, Hong; Zhu, Yingting; Zhang, Yingying; Jia, Yu; Li, Yiqing; Ge, Jian; Zhuo, Yehong

2017-01-01

The success rate of glaucoma filtration surgery is closely related to conjunctival inflammation, and the main mechanism of dry eye disease (DED) is inflammation. The aim of this study was to evaluate the effect of DED on bleb scar formation after rabbit glaucoma filtration surgery. Sixteen New Zealand white rabbits were randomly divided into control and DED groups. A DED model was induced by twice-daily topical administration of 0.1% benzalkonium chloride (BAC) drops for three weeks. Ocular examinations were performed to verify the DED model. Surgical effects were assessed, and histologic assessments were performed on the 28th postoperative day. Higher fluorescein staining scores, lower basal tear secretion levels and goblet cell counts, and increased interleukin 1β (IL-1β) levels were observed in the DED group. The DED eyes displayed significantly higher intraocular pressure (IOP)% on the 14th postoperative day; a smaller bleb area on days 14, 21 and 28; and a shorter bleb survival time. Moreover, proliferating cell nuclear antigen (PCNA) and alpha-smooth muscle actin (α-SMA) levels were significantly increased in the DED group. These results demonstrate that DED promotes filtering bleb scar formation and shortens bleb survival time; these effects may be mediated via IL-1β. PMID:28555041

Ophthalmic preservatives: focus on polyquaternium-1.

PubMed

Rolando, Maurizio; Crider, Julie Y; Kahook, Malik Y

2011-11-01

Ophthalmic preservatives, such as polyquaternium-1 (PQ-1), are critical for the inhibition of growth of microbial contaminants in multi-dose bottles of topical medications. These antimicrobial agents must have a high efficacy against pathogenic organisms, while maintaining a favorable tolerability and safety profile. This review focuses on the ophthalmic preservative PQ-1. For comparison purposes, the most commonly used preservative, benzalkonium chloride (BAK), is also discussed. This survey focuses primarily on data collected during the past 10 years. Effective drug delivery requires more than just an active ingredient that achieves its desired biological effect on end-target tissues. In addition, drugs must be stable in the containers that they are stored in, and must possess minimal undesired local and systemic side effects that can cause patients to decrease their adherence. In addressing these concerns, specifically in topical ophthalmic drops, one must take into account the active ingredients, vehicle components and preservatives. Medications with fewer adverse effects may lead to enhanced adherence to therapy; therefore, the induction of such adverse outcomes must be considered by physicians when treating patients with chronic ocular disease. Although BAK will continue to be used in ophthalmic medications, due to its familiarity and compatibility with a broad range of topical ocular formulations, PQ-1 is certainly a viable alternative in the preservative formulary armamentarium.

A comparative study of novel spectrophotometric methods based on isosbestic points; application on a pharmaceutical ternary mixture

NASA Astrophysics Data System (ADS)

Lotfy, Hayam M.; Saleh, Sarah S.; Hassan, Nagiba Y.; Salem, Hesham

This work represents the application of the isosbestic points present in different absorption spectra. Three novel spectrophotometric methods were developed, the first method is the absorption subtraction method (AS) utilizing the isosbestic point in zero-order absorption spectra; the second method is the amplitude modulation method (AM) utilizing the isosbestic point in ratio spectra; and third method is the amplitude summation method (A-Sum) utilizing the isosbestic point in derivative spectra. The three methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The components at the isosbestic point were determined using the corresponding unified regression equation at this point with no need for a complementary method. The obtained results were statistically compared to each other and to that of the developed PLS model. The specificity of the developed methods was investigated by analyzing laboratory prepared mixtures and the combined dosage form. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed.

Antimicrobial activity of essential oils against Staphylococcus aureus biofilms.

PubMed

Vázquez-Sánchez, Daniel; Cabo, Marta L; Rodríguez-Herrera, Juan J

2015-12-01

The present study was aimed to evaluate the potential of essential oils to remove the foodborne pathogen Staphylococcus aureus from food-processing facilities. The effectiveness of 19 essential oils against planktonic cells of S. aureus was firstly assessed by minimal inhibitory concentration. Planktonic cells showed a wide variability in resistance to essential oils, with thyme oil as the most effective, followed by lemongrass oil and then vetiver oil. The eight essential oils most effective against planktonic cells were subsequently tested against 48-h-old biofilms formed on stainless steel. All essential oils reduced significantly (p < 0.01) the number of viable biofilm cells, but none of them could remove biofilms completely. Thyme and patchouli oils were the most effective, but high concentrations were needed to achieve logarithmic reductions over 4 log CFU/cm(2) after 30 min exposure. Alternatively, the use of sub-lethal doses of thyme oil allowed to slow down biofilm formation and to enhance the efficiency of thyme oil and benzalkonium chloride against biofilms. However, some cellular adaptation to thyme oil was detected. Therefore, essential oil-based treatments should be based on the rotation and combination of different essential oils or with other biocides to prevent the emergence of antimicrobial-resistant strains. © The Author(s) 2014.

[Quaternary ammonium cytotoxicity in a human conjunctival cell line].

PubMed

Debbasch, C; de Saint Jean, M; Pisella, P J; Rat, P; Warnet, J M; Baudouin, C

1999-11-01

Ophthalmic preparations can induce conjunctival toxicity, often caused by preservatives. The aim of this study was to evaluate in vitro cytotoxicity of quaternary ammonium. Cytotoxicity tests were done on a continuous human conjunctival cell line using microplate cold light cytofluorimetry. Membrane integrity (neutral red test), DNA condensation (Hoechst 33342 test) and reactive oxygen species (ROS) production (dichlorofluorescein diacetate and hydroethidine tests) were evaluated on living cells treated with different concentrations of benzalkonium chloride, benzododecinium bromide and cetrimide (0.00001 to 0.01%) after 15 minutes of treatment or 15 minutes and 24 hours of cell recovery. All the compounds tested showed similar in vitro effects. Using the neutral red test, we observed a decrease in membrane integrity even at 0.005% and 0.01% (p < 0.001) and after a short time (15 minutes). A stimulation of ROS production (H2O2 and O2) was observed at 0.00001% and above (p < 0.001), associated with a chromatine condensation due to an apoptotic phenomenon. A necrotic phenomenon is suggested at high concentrations of quaternary ammonium preservatives whereas an apoptotic mechanism exists for lower concentrations. This toxicity observed in vitro can explain some of the ocular surface damage caused by long-term use of preserved eye-drops.

The Cutaneous Microbiome and Aspects of Skin Antimicrobial Defense System Resist Acute Treatment with Topical Skin Cleansers.

PubMed

Two, Aimee M; Nakatsuji, Teruaki; Kotol, Paul F; Arvanitidou, Evangelia; Du-Thumm, Laurence; Hata, Tissa R; Gallo, Richard L

2016-10-01

The human skin microbiome has been suggested to play an essential role in maintaining health by contributing to innate defense of the skin. These observations have inspired speculation that the use of common skin washing techniques may be detrimental to the epidermal antibacterial defense system by altering the microbiome. In this study, several common skin cleansers were used to wash human forearms and the short-term effect on the abundance of the antimicrobial peptide LL-37 and the abundance and diversity of bacterial DNA was measured. Despite small but significant decreases in the amount of LL-37 on the skin surface shortly after washing, no significant change in the bacterial community was detected. Furthermore, Group A Streptococcus did not survive better on the skin after washing. In contrast, the addition of antimicrobial compounds such as benzalkonium chloride or triclocarban to soap before washing decreased the growth of Group A Streptococcus applied after rinse. These results support prior studies that hand washing techniques in the health care setting are beneficial and should be continued. Additional research is necessary to better understand the effects of chronic washing and the potential impact of skin care products on the development of dysbiosis in some individuals. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

A comparative study of progressive versus successive spectrophotometric resolution techniques applied for pharmaceutical ternary mixtures.

PubMed

Saleh, Sarah S; Lotfy, Hayam M; Hassan, Nagiba Y; Salem, Hesham

2014-11-11

This work represents a comparative study of a novel progressive spectrophotometric resolution technique namely, amplitude center method (ACM), versus the well-established successive spectrophotometric resolution techniques namely; successive derivative subtraction (SDS); successive derivative of ratio spectra (SDR) and mean centering of ratio spectra (MCR). All the proposed spectrophotometric techniques consist of several consecutive steps utilizing ratio and/or derivative spectra. The novel amplitude center method (ACM) can be used for the determination of ternary mixtures using single divisor where the concentrations of the components are determined through progressive manipulation performed on the same ratio spectrum. Those methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the official BP methods, showing no significant difference with respect to accuracy and precision. Copyright © 2014 Elsevier B.V. All rights reserved.

Virucidal activity of chemical biocides against mimivirus, a putative pneumonia agent.

PubMed

Campos, Rafael Kroon; Andrade, Ketyllen Reis; Ferreira, Paulo Cesar Peregrino; Bonjardim, Cláudio Antônio; La Scola, Bernard; Kroon, Erna Geessien; Abrahão, Jônatas Santos

2012-12-01

Acanthamoeba polyphaga mimivirus (APMV), the largest known virus, has been studied as a putative pneumonia agent, especially in hospital environments. Despite the repercussions of the discovery of APMV, there has been no study related to the control of APMV and the susceptibility of this virus to disinfectants. This work investigated the virucidal activity against mimivirus of chemical biocides commonly used in clinical practice for the disinfection of hospital equipment and rooms. APMV was dried on sterilized steel coupons, exposed to different concentrations of alcohols (ethanol, 1-propanol and 2-propanol) and commercial disinfectants (active chlorine, glutaraldehyde and benzalkonium chloride) and titrated in amoebas using the TCID50 value. The stability of APMV on an inanimate surface was also tested in the presence and absence of organic matter for 30 days. APMV showed a high level of resistance to chemical biocides, especially alcohols. Only active chlorine and glutaraldehyde were able to decrease the APMV titers to undetectable levels. Dried APMV showed long-lasting stability on an inanimate surface (30 days), even in the absence of organic matter. The data presented herein may help health and laboratory workers plan the best strategy to control this putative pneumonia agent from surfaces and devices. Copyright © 2012 Elsevier B.V. All rights reserved.

Use of juglone as antibacterial and potential efflux pump inhibitors in Staphylococcus aureus isolated from the oral cavity.

PubMed

Zmantar, Tarek; Miladi, Hanene; Kouidhi, Bochra; Chaabouni, Yassine; Ben Slama, Rihab; Bakhrouf, Amina; Mahdouani, Kacem; Chaieb, Kamel

2016-12-01

In this study the minimal inhibitory concentration (MICs) of tetracycline (Tet), erythromycin (Ery) and benzalkonium chloride (BC) in absence and in presence of a sub-MIC of juglone (Jug) were determined. In addition, the Ethidium bromide (EtBr) efflux assay was performed to assess the effect of Jug on EtBr cells accumulation. Our results showed a selective antimicrobial activity of Jug against the tested strains. A synergistic effect of Jug, drugs (Tet and Ery) and disinfectant (BC) was noticed with a reduction rate varied from 2 to 16-fold. In addition, the efflux of EtBr was inhibited depending on the Jug concentration. In the presence of Jug, a decrease in loss of EtBr from bacteria was observed. The concentration inducing 50 % of EtBr efflux inhibition after 15 min was about 182 μg ml -1 for S. aureus ATCC 25923, 236 μg ml -1 for S. aureus B193 and 195 μg ml -1  for S. aureus B456. It appears from this study that Jug may be used as a natural source for resistance-modifying activity in same bacteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

Myenteric denervation differentially reduces enteroendocrine serotonin cell population in rats during postnatal development.

PubMed

Hernandes, Luzmarina; Fernandes, Marilda da Cruz; Pereira, Lucieni Cristina Marques da Silva; Freitas, Priscila de; Gama, Patrícia; Alvares, Eliana Parisi

2006-05-01

The enteric nervous and enteroendocrine systems regulate different processes in the small intestine. Ablation of myenteric plexus with benzalkonium chloride (BAC) stimulates epithelial cell proliferation, whereas endocrine serotonin cells may inhibit the process. To evaluate the connection between the systems and the influence of myenteric plexus on serotoninergic cells in rats during postnatal development, the ileal plexus was partially removed with BAC. Rats were treated at 13 or 21 days and sacrificed after 15 days. The cell bodies of myenteric neurons were stained by beta NADH-diaphorase to detect the extension of denervation. The number of enteroendocrine cells in the ileum was estimated in crypts and villi in paraffin sections immunostained for serotonin. The number of neurons was reduced by 27.6 and 45% in rats treated on the 13th and 21st days, respectively. We tried to establish a correlation of denervation and the serotonin population according to the age of treatment. We observed a reduction of immunolabelled cells in the crypts of rats treated at 13 days, whereas this effect was seen in the villi of rats denervated at 21 days. These results suggest that the enteric nervous system might control the enteroendocrine cell population and this complex mechanism could be correlated to changes in cell proliferation.

Breakdown evaluation of corneal epithelial barrier caused by antiallergic eyedrops using an electrophysiologic method.

PubMed

Nakashima, Mikiro; Nakamura, Tadahiro; Teshima, Mugen; To, Hideto; Uematsu, Masafumi; Kitaoka, Takashi; Taniyama, Kotaro; Nishida, Koyo; Nakamura, Junzo; Sasaki, Hitoshi

2008-02-01

The aim of this study was to examine the usefulness of an electrophysiologic method for predicting corneal epithelial breakdown by antiallergic eyedrops and comparing the results with those in other appraisal methods. Six kinds of antiallergic eyedrops, including benzalkonium chloride (BK) as an ophthalmic preservative and two kinds of BK-free antiallergic eyedrops, were used in this study. Eyedrops were applied to excise rabbit corneas and monitoring was performed according to an electrophysiologic method, using a commercially available chamber system to mimic human tear turnover. Changes in transepithelial electrical resistance (TEER) in the corneal surface were recorded. The cytotoxicity of each kind of eyedrops in a normal rabbit corneal epithelial (NRCE) cell line and a human endothelial cell line EA.hy926 was also examined. The extent of decrease in the corneal TEER after applying antiallergic eyedrops was dependent on the concentration of the BK included as a preservative, but it was also affected by the different kinds of drugs when the BK concentration was low. Higher cytotoxicity of the eyedrops against the NRCE and EA.hy926 cell lines was observed with a reduction of TEER. Monitoring changes in the corneal TEER, according to the electrophysiologic method with the application of antiallergic eyedrops, is useful for predicting corneal epithelial breakdown caused by their instillation.

Assessment of altered lipid homeostasis by HILIC-ion mobility-mass spectrometry-based lipidomics[S

PubMed Central

Hines, Kelly M.; Herron, Josi; Xu, Libin

2017-01-01

Ion mobility-mass spectrometry (IM-MS) has proven to be a highly informative technique for the characterization of lipids from cells and tissues. We report the combination of hydrophilic-interaction liquid chromatography (HILIC) with traveling-wave IM-MS (TWIM-MS) for comprehensive lipidomics analysis. Main lipid categories such as glycerolipids, sphingolipids, and glycerophospholipids are separated on the basis of their lipid backbones in the IM dimension, whereas subclasses of each category are mostly separated on the basis of their headgroups in the HILIC dimension, demonstrating the orthogonality of HILIC and IM separations. Using our previously established lipid calibrants for collision cross-section (CCS) measurements in TWIM, we measured over 250 CCS values covering 12 lipid classes in positive and negative modes. The coverage of the HILIC-IM-MS method is demonstrated in the analysis of Neuro2a neuroblastoma cells exposed to benzalkonium chlorides (BACs) with C10 or C16 alkyl chains, which we have previously shown to affect gene expression related to cholesterol and lipid homeostasis. We found that BAC exposure resulted in significant changes to several lipid classes, including glycerides, sphingomyelins, phosphatidylcholines, and phosphatidylethanolamines. Our results indicate that BAC exposure modifies lipid homeostasis in a manner that is dependent upon the length of the BAC alkyl chain. PMID:28167702

Efficacy of a hospital-wide environmental cleaning protocol on hospital-acquired methicillin-resistant Staphylococcus aureus rates.

PubMed

Watson, Paul Andrew; Watson, Luke Robert; Torress-Cook, Alfonso

2016-07-01

Environmental contamination has been associated with over half of methicillin-resistant Staphylococcus aureus (MRSA) outbreaks in hospitals. We explored if a hospital-wide environmental and patient cleaning protocol would lower hospital acquired MRSA rates and associated costs. This study evaluates the impact of implementing a hospital-wide environmental and patient cleaning protocol on the rate of MRSA infection and the potential cost benefit of the intervention. A retrospective, pre-post interventional study design was used. The intervention comprised a combination of enhanced environmental cleaning of high touch surfaces, daily washing of patients with benzalkonium chloride, and targeted isolation of patients with active infection. The rate of MRSA infection per 1000 patient days (PD) was compared with the rate after the intervention (Steiros Algorithm ® ) was implemented. A cost-benefit analysis based on the number of MRSA infections avoided was conducted. The MRSA rates decreased by 96% from 3.04 per 1000 PD to 0.11 per 1000 PD ( P <0.0001). This reduction in MRSA infections, avoided an estimated $1,655,143 in healthcare costs. Implementation of this hospital-wide protocol appears to be associated with a reduction in the rate of MRSA infection and therefore a reduction in associated healthcare costs.

Resistance to quaternary ammonium compounds in food-related bacteria.

PubMed

Sidhu, Maan Singh; Sørum, Henning; Holck, Askild

2002-01-01

Microbial resistance to antimicrobial agents continues to be a major problem. The frequent use and misuse of disinfectants based on quaternary ammonium compounds (QACs) in food-processing industries have imposed a selective pressure and may contribute to the emergence of disinfectant-resistant microorganisms. A total number of 1,325 Gram-negative isolates (Escherichia coli, other coliforms Vibrio spp., and Aeromonas spp.) and 500 Enterococcus spp. from food and food-processing industries and fish farming were screened for natural resistance to the QAC-based disinfectant benzalkonium chloride (BC). Of the 1,825 isolates, 16 strains, mainly from meat retail shops, showed low-level resistance to BC. None of the Enterococcus spp. from broiler, cattle, and pigs, the antibiotic-resistant E. coli from pig intestine and fish pathogens Vibrio spp. and Aeromonas spp. from the Norwegian fish farming industry were resistant to BC. The BC-resistant strains were examined for susceptibility to 15 different antibiotics, disinfectants, and dyes. No systematic cross-resistance between BC and any of the other antimicrobial agents tested was detected. Stable enhanced resistance in Enterobacter cloacae isolates was demonstrated by step-wise adaptation in increasing concentrations of BC. In conclusion, BC resistance among food-associated Gram-negative bacteria and Enterococcus spp. is not frequent, but resistance may develop to user concentrations after exposure to sublethal concentrations of BC.

SCI with Brain Injury: Bedside-to-Bench Modeling for Developing Treatment and Rehabilitation Strategies

DTIC Science & Technology

2012-10-01

SIMVASTATIN 2 SIMVASTATIN 1 METOPROLOL 1 METOPROLOL 1 Discharge  Medications Note that the length of stay in rehabilitation is shorter in SCVMC, a...ENOXAPARIN 3 GABAPENTIN 3 GABAPENTIN 2 DOXYCYCLINE 3 DOXYCYCLINE 1 LISINOPRIL 3 LISINOPRIL 1 CHLORHEXIDINE 2 CHLORHEXIDINE 2 METOPROLOL 2 METOPROLOL 2

Biological Impact of Senescence Induction in Prostate Cancer

DTIC Science & Technology

2010-01-01

with decreasing compound concentrations. Data showing chlorhexidine, bithionol, cytarabine and crassin acetate effectively inhibited proliferation...senescence with 25 nM doxorubicin were included as a positive control. Of the candi- date compounds, methotrexate, cytarabine , chlorhexidine, and IC261...then normalized to expression in untreated cells. Candidate compounds: methotrexate (MET), chlorhexadine (CHL), crassin acetate (CRA), cytarabine

SCI with Brain Injury: Bedside to Bench Modeling for Developing Treatment and Rehabilitation Strategies

DTIC Science & Technology

2013-10-01

LISINOPRIL 1 CHLORHEXIDINE 2 CHLORHEXIDINE 2 METOPROLOL 2 METOPROLOL 2 DEXTROSE 2 DEXTROSE 1 MICONAZOLE 2 MICONAZOLE 1 HEPARIN 1 HEPARIN 3 FENTANYL 1... FENTANYL 2 BACLOFEN 1 BACLOFEN 1 FERROUS  SULFATE 1 FERROUS  SULFATE 1 QUETIAPINE 1 QUETIAPINE 1 Admission  Medications 24 VA Frequency SCVMC

21 CFR 524.402 - Chlorhexidine.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Chlorhexidine. 524.402 Section 524.402 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS.... See Nos. 000856 and 058829 in § 510.600(c) of this chapter. (c) Conditions of use in dogs, cats, and...

Pilot study to evaluate 3 hygiene protocols on the reduction of bacterial load on the hands of veterinary staff performing routine equine physical examinations.

PubMed

Traub-Dargatz, Josie L; Weese, J Scott; Rousseau, Joyce D; Dunowska, Magdalena; Morley, Paul S; Dargatz, David A

2006-07-01

Reduction factors (RFs) for bacterial counts on examiners' hands were compared when performing a standardized equine physical examination, followed by the use of one of 3 hand-hygiene protocols (washing with soap, ethanol gel application, and chlorohexidine-ethanol application). The mean RFs were 1.29 log10 and 1.44 log10 at 2 study sites for the alcohol-gel (62% ethyl alcohol active ingredient) protocols and 1.47 log10 and 1.94 log10 at 2 study sites for the chlorhexidine-alcohol (61% ethyl alcohol plus 1% chlorhexidine active ingredients) protocols, respectively. The RFs were significantly different (P < 0.0001) between the hand-washing group and the other 2 treatment groups (the alcohol-gel and the chlorhexidine-alcohol lotion). The use of alcohol-based gels or chlorhexidine-alcohol hand hygiene protocols must still be proven effective in equine practice settings, but in this study, these protocols were equivalent or superior to hand washing for reduction in bacterial load on the hands of people after they perform routine physical examinations.

Effect of endodontic irrigating solutions on the microhardness and roughness of root canal dentin: an in vitro study.

PubMed

Patil, Chetan R; Uppin, Veerendra

2011-01-01

To evaluate the effect of widely used endodontic irrigating solutions on root dentin microhardness and surface roughness. One hundred twenty, non-carious extracted human permanent incisor teeth were selected. The crowns of the teeth were sectioned and the roots were separated longitudinally to get 240 specimens. These specimens were then divided into six groups according to the irrigating solutions used. The solutions used were 5% and 2.5% NaOCl solutions, 3% H2 O2 , 17% EDTA solution, 0.2% chlorhexidine gluconate, and distilled water. Then, the specimens were subjected to microhardness and roughness testing. The data were analyzed using ANOVA and Tukey's multiple comparison tests. The results of this study indicated that all irrigation solutions, except 0.2% chlorhexidine gluconate, decreased the microhardness of root dentin, and 3% H2 O2 and 0.2% chlorhexidine gluconate had no effect on surface roughness. Within the limitation of this study, it is concluded that 0.2% chlorhexidine gluconate seems to be an appropriate irrigation solution, because of its harmless effect on the microhardness and surface roughness of root canal dentin.

Biofilm removal and antimicrobial activity of two different air-polishing powders: an in vitro study.

PubMed

Drago, Lorenzo; Del Fabbro, Massimo; Bortolin, Monica; Vassena, Christian; De Vecchi, Elena; Taschieri, Silvio

2014-11-01

Biofilm removal plays a central role in the prevention of periodontal and peri-implant diseases associated with microbial infections. Plaque debridement may be accomplished by air polishing using abrasive powders. In this study, a new formulation consisting of erythritol and chlorhexidine is compared with the standard glycine powder used in air-polishing devices. Their in vitro antimicrobial and antibiofilm effects on Staphylococcus aureus, Bacteroides fragilis, and Candida albicans are investigated. Biofilm was allowed to grow on sandblasted titanium disks and air polished with glycine or erythritol-chlorhexidine powders. A semiquantitative analysis of biofilm by spectrophotometric assay was performed. A qualitative analysis was also carried out by confocal laser scanning microscopy. Minimum inhibitory concentrations and minimum microbicidal concentrations were evaluated, together with the microbial recovery from the residual biofilm after air-polishing treatment. The combination of erythritol and chlorhexidine displayed stronger antimicrobial and antibiofilm activity than glycine against all microbial strains tested. Air polishing with erythritol-chlorhexidine seems to be a viable alternative to the traditional glycine treatment for biofilm removal.

Comparison of two shampoos for treatment of Malassezia pachydermatis-associated seborrhoeic dermatitis in basset hounds.

PubMed

Bond, R; Rose, J F; Ellis, J W; Lloyd, D H

1995-03-01

A randomised-double-blind parallel study compared the clinical and antimicrobial efficacies of a miconazole-chlorhexidine shampoo with a selenium sulphide shampoo for the treatment of seborrhoeic dermatitis associated with Malassezia pachydermatis in 33 basset hounds. All 16 miconazole-chlorhexidine treated hounds and 11 of 17 selenium sulphide treated hounds improved when shampooed at three-day intervals for three weeks. The miconazole-chlorhexidine treated hounds showed significantly greater reductions in pruritus (P < 0.01), erythema (P < 0.001), exudation (P < 0.01) and overall severity (P < 0.001), and in counts of M pachydermatis (P < 0.001), total bacteria (P < 0.001) and coagulase-positive staphylococci (P < 0.001), when compared to the selenium sulphide treated group. Improvements in scaling and coat condition did not vary significantly between the two groups. These results indicate that seborrhoeic dermatitis in basset hounds is often associated with elevated cutaneous populations of M pachydermatis and bacteria, and that the miconazole-chlorhexidine shampoo is more effective than the selenium sulphide product for the treatment for this disease.

Pilot study to evaluate 3 hygiene protocols on the reduction of bacterial load on the hands of veterinary staff performing routine equine physical examinations

PubMed Central

Traub-Dargatz, Josie L.; Weese, J. Scott; Rousseau, Joyce D.; Dunowska, Magdalena; Morley, Paul S.; Dargatz, David A.

2006-01-01

Abstract Reduction factors (RFs) for bacterial counts on examiners’ hands were compared when performing a standardized equine physical examination, followed by the use of one of 3 hand-hygiene protocols (washing with soap, ethanol gel application, and chlorohexidine-ethanol application). The mean RFs were 1.29 log10 and 1.44 log10 at 2 study sites for the alcohol-gel (62% ethyl alcohol active ingredient) protocols and 1.47 log10 and 1.94 log10 at 2 study sites for the chlorhexidine-alcohol (61% ethyl alcohol plus 1% chlorhexidine active ingredients) protocols, respectively. The RFs were significantly different (P < 0.0001) between the hand-washing group and the other 2 treatment groups (the alcohol-gel and the chlorhexidine-alcohol lotion). The use of alcohol-based gels or chlorhexidine-alcohol hand hygiene protocols must still be proven effective in equine practice settings, but in this study, these protocols were equivalent or superior to hand washing for reduction in bacterial load on the hands of people after they perform routine physical examinations. PMID:16898109

Evaluation and Comparison of the Antibacterial Activity against Streptococcus mutans of Grape Seed Extract at Different Concentrations with Chlorhexidine Gluconate: An in vitro Study.

PubMed

Swadas, Milan; Dave, Bhavna; Vyas, Soham M; Shah, Nupur

2016-01-01

Streptococcus mutans has been implicated as primary microorganisms which cause dental caries in humans. There has been an increased interest in the therapeutic properties of some medicinal plants and natural compounds which have demonstrated antibacterial activities. Grape is one of the plants of this group which contains tannin and polyphenolic compound. To evaluate and compare antibacterial activity of grape seed extract at different concentrations with chlorhexidine gluconate against S. mutans. Grape seeds were extracted with ethanol/water ratio of 70:30 volume/volume. The extracts were filtered through Whatman No. 1 filter paper until it becomes colorless. Streptococcus mutans strains were taken. To check the antimicrobial properties of grape seed extract at different concentration and chlorhexidine gluconate, they were added to S. mutans strain and incubated for 48 hours than colony-forming units/mL were checked. Grape seed extract at higher concentration were found to be more potent against S. mutans. Chlorhexidine gluconate was found to have most potent antibacterial action compared to all different concentrations of grape seed extract. Grape seed extract as a natural antimicrobial compound has inhibitory effect against S. mutans. Swadas M, Dave B, Vyas SM, Shah N. Evaluation and Comparison of the Antibacterial Activity against Streptococcus mutans of Grape Seed Extract at Different Concentrations with Chlorhexidine Gluconate: An in vitro Study. Int J Clin Pediatr Dent 2016;9(3):181-185.

Antibacterial effect of triantibiotic mixture, chlorhexidine gel, and two natural materials Propolis and Aloe vera against Enterococcus faecalis: An ex vivo study.

PubMed

Bazvand, Leila; Aminozarbian, Mohammad Ghasem; Farhad, Alireza; Noormohammadi, Hamid; Hasheminia, Seyed Mohsen; Mobasherizadeh, Sina

2014-07-01

The aim of this ex vivo study was to compare the antimicrobial effect of triantibiotic paste, 0.2% chlorhexidine gel, Propolis and Aloe vera on Enterococcus faecalis in deep dentin. Ninety fresh extracted single-rooted teeth were used in a dentin block model. Seventy-five teeth were infected with E. faecalis and divided into four experimental groups (n = 15). Experimental groups were treated with triantibiotic mixture with distilled water, 0.2% chlorhexidine gel, 70% ethanol + Propolis and Aloe vera. Fifteen teeth treated with distilled water as the positive control and 15 samples, free of bacterial contamination, were considered as the negative control. Gates-Glidden drill #4 was used for removal of surface dentin and Gates-Glidden drill #5 was used to collect samples of deep dentin. The samples were prepared and colony-forming units were counted. Data were analyzed by one-way ANOVA and post hoc Tukey tests. Statistical significance was defined at P < 0.05. Triantibiotic mixture group exhibited the least bacterial growth. However, the rate of bacterial growth showed no significant differences between chlorhexidine and Propolis groups (P > 0.05). Aloe vera had antibacterial effects on E. faecalis, but in comparison with other medicaments, it was less effective (P < 0.05). This experimental study showed that triantibiotic mixture, 0.2% chlorhexidine gel, Propolis and Aleo vera were relatively effective against E. faecalis. All the intracanal medicements had similar effects on E. faecalis in deep dentin except for Aloe vera.

Standardized comparison of antiseptic efficacy of triclosan, PVP-iodine, octenidine dihydrochloride, polyhexanide and chlorhexidine digluconate.

PubMed

Koburger, T; Hübner, N-O; Braun, M; Siebert, J; Kramer, A

2010-08-01

This study presents a comparative investigation of the antimicrobial efficacy of the antiseptics PVP-iodine, triclosan, chlorhexidine, octenidine and polyhexanide used for pre-surgical antisepsis and antiseptic treatment of skin, wounds and mucous membranes based on internationally accepted standards. MICs and MBCs were determined in accordance with DIN 58940-7 and 58940-8 using Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus), Enterococcus faecalis (including vancomycin-resistant Enterococcus), Streptococcus pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Clostridium perfringens, Haemophilus influenzae and Candida albicans. The microbicidal efficacy was determined in accordance with DIN EN 1040 and 1275 using S. aureus, P. aeruginosa and C. albicans. For chlorhexidine, octenidine and polyhexanide, MIC(48) and MBC(24) ranged from 16 to 32 mg/L. Maximum values for triclosan ranged from 256 to 512 mg/L, with an efficacy gap against P. aeruginosa, while the maximum values of PVP-iodine were 1024 mg/L, with a gap against S. pneumoniae. Comparing the minimal effective concentrations, octenidine was most effective. After 1 min, only octenidine and PVP-iodine fulfil the requirements for antiseptics. Tests under standardized and harmonized conditions help to choose the most efficacious agent. When a prolonged contact time is feasible, ranking of agents would be polyhexanide = octenidine > chlorhexidine > triclosan > PVP-iodine. This is consistent with the recommendations for antisepsis of acute wounds. Polyhexanide seems to be preferable for chronic wounds due to its higher tolerability. If an immediate effect is required, ranking would be octenidine = PVP-iodine> polyhexanide > chlorhexidine > triclosan.

Effectiveness of probiotic, chlorhexidine and fluoride mouthwash against Streptococcus mutans – Randomized, single-blind, in vivo study

PubMed Central

Jothika, Mohan; Vanajassun, P. Pranav; Someshwar, Battu

2015-01-01

Aim: To determine the short-term efficiency of probiotic, chlorhexidine, and fluoride mouthwashes on plaque Streptococcus mutans level at four periodic intervals. Materials and Methods: This was a single-blind, randomized control study in which each subject was tested with only one mouthwash regimen. Fifty-two healthy qualified adult patients were selected randomly for the study and were divided into the following groups: group 1- 10 ml of distilled water, group 2- 10 ml of 0.2% chlorhexidine mouthwash, group 3- 10 ml of 500 ppm F/400 ml sodium fluoride mouthwash, and group 4- 10 ml of probiotic mouthwash. Plaque samples were collected from the buccal surface of premolars and molars in the maxillary quadrant. Sampling procedure was carried out by a single examiner after 7 days, 14 days, and 30 days, respectively, after the use of the mouthwash. All the samples were subjected to microbiological analysis and statistically analyzed with one-way analysis of variance (ANOVA) and post-hoc test. Results: One-way ANOVA comparison among groups 2, 3, and 4 showed no statistical significance, whereas group 1 showed statistically significant difference when compared with groups 2, 3, and 4 at 7th, 14th, and 30th day. Conclusion: Chlorhexidine, sodium fluoride, and probiotic mouthwashes reduce plaque S. mutans levels. Probiotic mouthwash is effective and equivalent to chlorhexidine and sodium fluoride mouthwashes. Thus, probiotic mouthwash can also be considered as an effective oral hygiene regimen. PMID:25984467

[Subcutaneous implantation type central venous port management in patients with malignant tumors effect of different antiseptic agents on central venous port-related infection].

PubMed

Sato, Junya; Kumagai, Masumi; Kato, Kenichi; Akahane, Akio; Suzuki, Michiko; Kashiwaba, Masahiro; Sone, Miyuki; Kudo, Kenzo

2014-08-01

Subcutaneous implantation type central venous ports(CV ports)are used in chemotherapy. Here, we prospectively examined the frequency of CV port-related infections when the disinfectant was changed from 10% povidone iodine to 1% chlorhexidine ethanol or 70% ethanol. The subjects were patients with malignant tumors, who had newly been implanted with CV ports. We examined CV port-related infections at 1 week after CV port implantation and every 2 weeks thereafter, following sterilization upon insertion of a Huber needle to the CV port. CV port evulsion due to CV port-related infection was noted in 3 patients(4.8%)in whom 15%chlorhexidine ethanol was used(n=62)and in 2 patients(3.3%)in whom 70% ethanol was used(n=60). Infection rates per 1,000 days of CV port use were 1.48% and 1.01%, respectively. Thus, the outcomes of sterilization using 1% chlorhexidine ethanol and 70% ethanol did not differ significantly from those on using 10% povidone iodine for sterilization, based on preliminary results at our institution(3 of 59 patients[5.1%]had port evulsion due to CV port-related infection and the infection rate per 1,000 days of CV port use was 1.47%, Akahane et al, 2012). Chlorhexidine ethanol and ethanol are very convenient to use because they dry quickly and do not need discoloration. Accordingly, chlorhexidine ethanol and ethanol might be useful in CV port management.