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Sample records for bactericidal agent triclosan

  1. The bactericidal agent triclosan modulates thyroid hormone-associated gene expression and disrupts postembryonic anuran development

    Energy Technology Data Exchange (ETDEWEB)

    Veldhoen, Nik [Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Skirrow, Rachel C. [Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2 (Canada); Osachoff, Heather [Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2 (Canada); Wigmore, Heidi [Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2 (Canada); Clapson, David J. [Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Gunderson, Mark P. [Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Van Aggelen, Graham [Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2 (Canada); Helbing, Caren C. [Department of Biochemistry and Microbiology, P.O. Box 3055, Stn. CSC, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada)]. E-mail: chelbing@uvic.ca

    2006-12-01

    We investigated whether exposure to environmentally relevant concentrations of the bactericidal agent, triclosan, induces changes in the thyroid hormone-mediated process of metamorphosis of the North American bullfrog, Rana catesbeiana and alters the expression profile of thyroid hormone receptor (TR) {alpha} and {beta}, basic transcription element binding protein (BTEB) and proliferating nuclear cell antigen (PCNA) gene transcripts. Premetamorphic tadpoles were immersed in environmentally relevant concentrations of triclosan and injected with 1 x 10{sup -11} mol/g body weight 3,5,3'-triiodothyronine (T{sub 3}) or vehicle control. Morphometric measurements and steady-state mRNA levels obtained by quantitative polymerase chain reaction were determined. mRNA abundance was also examined in Xenopus laevis XTC-2 cells treated with triclosan and/or 10 nM T{sub 3}. Tadpoles pretreated with triclosan concentrations as low as 0.15 {+-} 0.03 {mu}g/L for 4 days showed increased hindlimb development and a decrease in total body weight following T{sub 3} administration. Triclosan exposure also resulted in decreased T{sub 3}-mediated TR{beta} mRNA expression in the tadpole tail fin and increased levels of PCNA transcript in the brain within 48 h of T{sub 3} treatment whereas TR{alpha} and BTEB were unaffected. Triclosan alone altered thyroid hormone receptor {alpha} transcript levels in the brain of premetamorphic tadpoles and induced a transient weight loss. In XTC-2 cells, exposure to T{sub 3} plus nominal concentrations of triclosan as low as 0.03 {mu}g/L for 24 h resulted in altered thyroid hormone receptor mRNA expression. Exposure to low levels of triclosan disrupts thyroid hormone-associated gene expression and can alter the rate of thyroid hormone-mediated postembryonic anuran development.

  2. Bactericidal effects of triclosan in soap both in vitro and in vivo.

    Science.gov (United States)

    Kim, S A; Moon, H; Lee, K; Rhee, M S

    2015-12-01

    On December 2013, the US FDA proposed a rule stating that manufacturers must provide data to demonstrate that antibacterial soap is more effective than plain soap or water. The objective of the present study was to examine the in vitro and in vivo bactericidal effect of triclosan (the most widely used antiseptic agent in soap) in soap. Twenty bacterial strains (proposed by the FDA) were exposed to plain and antibacterial soaps (the same formulation as plain soap, but containing 0.3% triclosan) for 20 s at 22°C (room temperature) and 40°C (warm temperature). The temperature and time were selected to simulate the hand washing conditions and procedures used by consumers. The triclosan concentration of 0.3% is the maximum allowed by law. The decontamination efficacy of plain soap and antibacterial soap was also examined in vivo: the hands of volunteers were artificially inoculated with Serratia marcescens. There was no significant difference (P > 0.05) in bactericidal activity between plain soap and antibacterial soap at either test temperature. However, antibacterial soap showed significantly greater bactericidal effects after 9 h. These results suggest that although triclosan-containing soap does have antibacterial activity, the effects are not apparent during the short time required for hand washing. Antibacterial soap containing triclosan (0.3%) was no more effective than plain soap at reducing bacterial contamination when used under 'real-life' conditions. The present study provides practical information that may prove useful for both industry and governments. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Electrospun biodegradable polymers loaded with bactericide agents

    Directory of Open Access Journals (Sweden)

    Ramaz Katsarava

    2016-03-01

    Full Text Available Development of materials with an antimicrobial activity is fundamental for different sectors, including medicine and health care, water and air treatment, and food packaging. Electrospinning is a versatile and economic technique that allows the incorporation of different natural, industrial, and clinical agents into a wide variety of polymers and blends in the form of micro/nanofibers. Furthermore, the technique is versatile since different constructs (e.g. those derived from single electrospinning, co-electrospinning, coaxial electrospinning, and miniemulsion electrospinning can be obtained to influence the ability to load agents with different characteristics and stability and to modify the release behaviour. Furthermore, antimicrobial agents can be loaded during the electrospinning process or by a subsequent coating process. In order to the mitigate burst release effect, it is possible to encapsulate the selected drug into inorganic nanotubes and nanoparticles, as well as in organic cyclodextrine polysaccharides. In the same way, processes that involve covalent linkage of bactericide agents during surface treatment of electrospun samples may also be considered. The present review is focused on more recent works concerning the electrospinning of antimicrobial polymers. These include chitosan and common biodegradable polymers with activity caused by the specific load of agents such as metal and metal oxide particles, quaternary ammonium compounds, hydantoin compounds, antibiotics, common organic bactericides, and bacteriophages.

  4. Retainment of the antimicrobial agent triclosan in a septic tank

    DEFF Research Database (Denmark)

    Kirjanova, Ala; Rimeika, Mindaugas; Vollertsen, Jes

    2014-01-01

    Laboratory experiments were conducted to investigate the fate of the antimicrobial agent triclosan (TCS) in a conventional septic tank. The main mechanism of TCS removal from wastewater was identified to be rapid TCS sorption to suspended particles followed by settling of these particles to the b......Laboratory experiments were conducted to investigate the fate of the antimicrobial agent triclosan (TCS) in a conventional septic tank. The main mechanism of TCS removal from wastewater was identified to be rapid TCS sorption to suspended particles followed by settling of these particles...

  5. Long-term effects of the antibacterial agent triclosan on marine periphyton communities.

    Science.gov (United States)

    Eriksson, K Martin; Johansson, C Henrik; Fihlman, Viktor; Grehn, Alexander; Sanli, Kemal; Andersson, Mats X; Blanck, Hans; Arrhenius, Åsa; Sircar, Triranta; Backhaus, Thomas

    2015-09-01

    Triclosan is a widely used antibacterial agent that has become a ubiquitous contaminant in freshwater, estuary, and marine environments. Concerns about potential adverse effects of triclosan have been described in several recent risk assessments. Its effects on freshwater microbial communities have been well studied, but studies addressing effects on marine microbial communities are scarce. In the present study, the authors describe short- and long-term effects of triclosan on marine periphyton (microbial biofilm) communities. Short-term effects on photosynthesis were estimated after 60 min to 210 min of exposure. Long-term effects on photosynthesis, chlorophyll a fluorescence, pigment content, community tolerance, and bacterial carbon utilization were studied after exposing periphyton for 17 d in flow-through microcosms to 0.316 nM to 10,000 nM triclosan. Results from the short-term studies show that triclosan is toxic to periphyton photosynthesis. Half maximal effective concentration (EC50) values of 1080 nM and 3000 nM were estimated using (14)CO2-incorporation and pulse amplitude modulation (PAM) fluorescence measurements, respectively. After long-term triclosan exposure in flow-through microcosms, photosynthesis estimated using PAM fluorometry was not inhibited by triclosan concentrations up to 1000 nM but instead increased with increasing triclosan concentration. Similarly, at exposure concentrations of 31.6 nM and higher, triclosan caused an increase in photosynthetic pigments. At 316 nM triclosan, the pigment amounts were increased by a factor of 1.4 to 1.9 compared with the control level. Pollution-induced community tolerance was observed for algae and cyanobacteria at 100 nM triclosan and higher. Despite the widespread use of triclosan as an antibacterial agent, the compound did not have any effects on bacterial carbon utilization after long-term exposure.

  6. Metabolization of the bacteriostatic agent triclosan in edible plants and its consequences for plant uptake assessment.

    Science.gov (United States)

    Macherius, André; Eggen, Trine; Lorenz, Wilhelm; Moeder, Monika; Ondruschka, Jelka; Reemtsma, Thorsten

    2012-10-02

    Persistent environmental contaminants may enter agricultural fields via the application of sewage sludge, by irrigation with treated municipal wastewater or by manuring. It has been shown that such contaminants can be incorporated into crop plants. The metabolism of the bacteriostatic agents triclocarban, triclosan, and its transformation product methyl triclosan was investigated after their uptake into carrot cell cultures. A fast metabolization of triclosan was observed and eight so far unknown phase II metabolites, conjugates with saccharides, disaccharides, malonic acid, and sulfate, were identified by liquid chromatography-mass spectrometry. Triclocarban and methyl triclosan lack a phenolic group and remained unaltered in the cell cultures. Phase I metabolization was not observed for any of the compounds. All eight triclosan conjugates identified in the cell cultures were also detected in extracts of intact carrot plants cultivated on triclosan contaminated soils. Their total amount in the plants was assessed to exceed the amount of the triclosan itself by a factor of 5. This study shows that a disregard of conjugates in studies on plant uptake of environmental contaminants may severely underestimates the extent of uptake into plants and, eventually, the potential human exposure to contaminants via food of plant origin.

  7. Antibacterial agent triclosan suppresses RBL-2H3 mast cell function

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    Palmer, Rachel K., E-mail: rachel.palmer@maine.edu [Graduate School of Biomedical Sciences, University of Maine, Orono, ME 04469 (United States); Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469 (United States); Hutchinson, Lee M.; Burpee, Benjamin T.; Tupper, Emily J.; Pelletier, Jonathan H.; Kormendy, Zsolt; Hopke, Alex R.; Malay, Ethan T.; Evans, Brieana L.; Velez, Alejandro [Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469 (United States); Gosse, Julie A., E-mail: julie.gosse@umit.maine.edu [Graduate School of Biomedical Sciences, University of Maine, Orono, ME 04469 (United States); Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469 (United States)

    2012-01-01

    Triclosan is a broad-spectrum antibacterial agent, which has been shown previously to alleviate human allergic skin disease. The purpose of this study was to investigate the hypothesis that the mechanism of this action of triclosan is, in part, due to effects on mast cell function. Mast cells play important roles in allergy, asthma, parasite defense, and carcinogenesis. In response to various stimuli, mast cells degranulate, releasing allergic mediators such as histamine. In order to investigate the potential anti-inflammatory effect of triclosan on mast cells, we monitored the level of degranulation in a mast cell model, rat basophilic leukemia cells, clone 2H3. Having functional homology to human mast cells, as well as a very well defined signaling pathway leading to degranulation, this cell line has been widely used to gain insight into mast-cell driven allergic disorders in humans. Using a fluorescent microplate assay, we determined that triclosan strongly dampened the release of granules from activated rat mast cells starting at 2 μM treatment, with dose-responsive suppression through 30 μM. These concentrations were found to be non-cytotoxic. The inhibition was found to persist when early signaling events (such as IgE receptor aggregation and tyrosine phosphorylation) were bypassed by using calcium ionophore stimulation, indicating that the target for triclosan in this pathway is likely downstream of the calcium signaling event. Triclosan also strongly suppressed F-actin remodeling and cell membrane ruffling, a physiological process that accompanies degranulation. Our finding that triclosan inhibits mast cell function may explain the clinical data mentioned above and supports the use of triclosan or a mechanistically similar compound as a topical treatment for allergic skin disease, such as eczema. -- Highlights: ►The effects of triclosan on mast cell function using a murine mast cell model. ►Triclosan strongly inhibits degranulation of mast cells. ►Triclosan

  8. Characterization of dentifrices containing desensitizing agents, triclosan or whitening agents: EDX and SEM analysis.

    Science.gov (United States)

    Pinto, Shelon Cristina Souza; Hilgenberg, Sérgio Paulo; Wambier, Denise Stadler; Farago, Paulo Vitor; Bandéca, Matheus Coelho; Santos, Fábio André

    2014-01-01

    Dentifrices with different compositions are available on the market, but there is limited information about their properties. The aim of this in vitro study was to evaluate the physicochemical characteristics of 12 dentifrices divided into three categories, as containing desensitizing agents, Triclosan or whitening agents. Desiccation loss/residue analysis: 5 g of dentifrice was weighed five times for each group. pH analysis: 5 g of dentifrice were diluted in three parts of distilled water and analyzed using a digital potentiometer. Scanning electron microscopy (SEM): analysis of ashes, shape and size of the particles. Energy-dispersive x-ray spectroscopy (EDX): identification of the abrasive elements. Data were analyzed using ANOVA, Bonferroni post hoc test (α=0.05). Desiccation loss: 38.21% to 65.83%. Dentifrices containing Triclosan and desensitizing agents showed statistically significant differences among them (pSensodyne Branqueador (44.72%, 65.83%, respectively). Most dentifrices presented neutral or basic pH. Different shape and size particles were observed in the SEM analysis. Abrasive elements were identified in the EDX. These results demonstrate that the evaluated dentifrices had different properties and their composition influences directly their characteristics, thus resulting in a more or less abrasive action on tooth surface. Knowing the characteristics of the dentifrices is important to indicate the ideal product for each case.

  9. Consumer-mediated nutrient recycling is influenced by interactions between nutrient enrichment and the anti-microbial agent triclosan

    Science.gov (United States)

    Triclosan (5-chloro-2-(2, 4-dichlorophenoxy)phenol) is a widely used antimicrobial agent in personal care products whose fate and transport in aquatic ecosystems is a growing environmental concern. Evidence for chronic ecological effects of triclosan in aquatic organisms is increasing. At larger sca...

  10. Interactions between the antimicrobial agent triclosan and the bloom-forming cyanobacteria Microcystis aeruginosa

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiaolong [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Wuhan Zhongke Hydrobiological Environment Engineering Co., Ltd, Wuhan 430071 (China); Tu, Yenan; Song, Chaofeng; Li, Tiancui; Lin, Juan [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Wu, Yonghong [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, Nanjing 210008 (China); Liu, Jiantong [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Wu, Chenxi, E-mail: chenxi.wu@ihb.ac.cn [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China)

    2016-03-15

    Highlights: • Triclosan inhibit the growth and photosynthesis of M. aeruginosa at environmental relevant level. • TEM imaging showed destruction of M. aeruginosa cell ultrastructure during triclosan exposure. • Triclosan can be biotransformed by M. aeruginosa with methylation as a major pathway. • Presence of M. aeruginosa enhanced the photodegradation of triclosan. - Abstract: Cyanobacteria can co-exist in eutrophic waters with chemicals or other substances derived from personal care products discharged in wastewater. In this work, we investigate the interactions between the antimicrobial agent triclosan (TCS) and the bloom-forming cyanobacteria Microcystis aeruginosa. M. aeruginosa was very sensitive to TCS with the 96 h lowest observed effect concentration of 1.0 and 10 μg/L for inhibition of growth and photosynthetic activity, respectively. Exposure to TCS at environmentally relevant levels (0.1–2.0 μg/L) also affected the activities of superoxide dismutase (SOD) and the generation of reduced glutathione (GSH), while microcystin production was not affected. Transmission electron microscope (TEM) examination showed the destruction of M. aeruginosa cell ultrastructure during TCS exposure. TCS however, can be biotransformed by M. aeruginosa with methylation as a major biotransformation pathway. Furthermore, the presence of M. aeruginosa in solution promoted the photodegradation of TCS. Overall, our results demonstrate that M. aeruginosa plays an important role in the dissipation of TCS in aquatic environments but high residual TCS can exert toxic effects on M. aeruginosa.

  11. The fatty acid synthase inhibitor triclosan: repurposing an anti-microbial agent for targeting prostate cancer.

    Science.gov (United States)

    Sadowski, Martin C; Pouwer, Rebecca H; Gunter, Jennifer H; Lubik, Amy A; Quinn, Ronald J; Nelson, Colleen C

    2014-10-15

    Inhibition of FASN has emerged as a promising therapeutic target in cancer, and numerous inhibitors have been investigated. However, severe pharmacological limitations have challenged their clinical testing. The synthetic FASN inhibitor triclosan, which was initially developed as a topical antibacterial agent, is merely affected by these pharmacological limitations. Yet, little is known about its mechanism in inhibiting the growth of cancer cells. Here we compared the cellular and molecular effects of triclosan in a panel of eight malignant and non-malignant prostate cell lines to the well-known FASN inhibitors C75 and orlistat, which target different partial catalytic activities of FASN. Triclosan displayed a superior cytotoxic profile with a several-fold lower IC50 than C75 or orlistat. Structure-function analysis revealed that alcohol functionality of the parent phenol is critical for inhibitory action. Rescue experiments confirmed that end product starvation was a major cause of cytotoxicity. Importantly, triclosan, C75 and orlistat induced distinct changes to morphology, cell cycle, lipid content and the expression of key enzymes of lipid metabolism, demonstrating that inhibition of different partial catalytic activities of FASN activates different metabolic pathways. These finding combined with its well-documented pharmacological safety profile make triclosan a promising drug candidate for the treatment of prostate cancer.

  12. Triclosan-resistant bacteria isolated from feedlot and residential soils.

    Science.gov (United States)

    Welsch, Tanner T; Gillock, Eric T

    2011-01-01

    Triclosan is an antimicrobial agent that is currently incorporated into hundreds of consumer and medical products. It can be either a bacteriostatic or bactericidal agent, depending on its formulation. It has activity against Gram-positive and Gram-negative bacteria, as well as some viruses and protists. The purpose of this study was to determine whether triclosan-resistant bacteria could be isolated from the soil. Soils from cattle feedlots and residential lawns were collected and assayed for the presence of these organisms by plating samples on growth media containing triclosan. Organisms were subsequently identified by partial 16S rRNA sequencing analysis. All the organisms isolated in this study were Gram-negative rods, with members of genus Pseudomonas being particularly well represented. This result may not be surprising because Gram-negative organisms are generally more resistant to triclosan, and since Pseudomonas bacteria are known to have numerous efflux mechanisms for dealing with harmful substances.

  13. Bacteriostatic and bactericidal activities of 24 antimicrobial agents against Campylobacter fetus subsp. jejuni.

    OpenAIRE

    Vanhoof, R.; Gordts, B; Dierickx, R; Coignau, H; Butzler, J P

    1980-01-01

    The bacteriostatic and bactericidal activities of 24 antimicrobial agents were tested with the Dynatech MIC 2000 system against 86 strains of Campylobacter fetus subsp. jejuni from human sources. The penicillins (penicillin G, ampicillin, amoxycillin, carbenicillin) had poor activity. Ampicillin and amoxycillin were equally active. Cefotaxime revealed a rather good activity. Erythromycin, gentamicin, tobramycin, amikacin, and furazolidone were the most active compounds. Two strains (2.3%) wer...

  14. Triclosan antimicrobial polymers

    Directory of Open Access Journals (Sweden)

    Richard C. Petersen

    2016-03-01

    Full Text Available Triclosan antimicrobial molecular fluctuating energies of nonbonding electron pairs for the oxygen atom by ether bond rotations are reviewed with conformational computational chemistry analyses. Subsequent understanding of triclosan alternating ether bond rotations is able to help explain several material properties in Polymer Science. Unique bond rotation entanglements between triclosan and the polymer chains increase both the mechanical properties of polymer toughness and strength that are enhanced even better through secondary bonding relationships. Further, polymer blend compatibilization is considered due to similar molecular relationships and polarities. With compatibilization of triclosan in polymers a more uniform stability for nonpolar triclosan in the polymer solid state is retained by the antimicrobial for extremely low release with minimum solubility into aqueous solution. As a result, triclosan is projected for long extended lifetimes as an antimicrobial polymer additive. Further, triclosan rapid alternating ether bond rotations disrupt secondary bonding between chain monomers in the resin state to reduce viscosity and enhance polymer blending. Thus, triclosan is considered for a polymer additive with multiple properties to be an antimicrobial with additional benefits as a nonpolar toughening agent and a hydrophobic wetting agent. The triclosan material relationships with alternating ether bond rotations are described through a complete different form of medium by comparisons with known antimicrobial properties that upset bacterial cell membranes through rapid fluctuating mechanomolecular energies. Also, triclosan bond entanglements with secondary bonding can produce structural defects in weak bacterial lipid membranes requiring pliability that can then interfere with cell division. Regarding applications with polymers, triclosan can be incorporated by mixing into a resin system before cure, melt mixed with thermoplastic polymers

  15. Triclosan antimicrobial polymers

    Science.gov (United States)

    Petersen, Richard C.

    2016-01-01

    Triclosan antimicrobial molecular fluctuating energies of nonbonding electron pairs for the oxygen atom by ether bond rotations are reviewed with conformational computational chemistry analyses. Subsequent understanding of triclosan alternating ether bond rotations is able to help explain several material properties in Polymer Science. Unique bond rotation entanglements between triclosan and the polymer chains increase both the mechanical properties of polymer toughness and strength that are enhanced even better through secondary bonding relationships. Further, polymer blend compatibilization is considered due to similar molecular relationships and polarities. With compatibilization of triclosan in polymers a more uniform stability for nonpolar triclosan in the polymer solid state is retained by the antimicrobial for extremely low release with minimum solubility into aqueous solution. As a result, triclosan is projected for long extended lifetimes as an antimicrobial polymer additive. Further, triclosan rapid alternating ether bond rotations disrupt secondary bonding between chain monomers in the resin state to reduce viscosity and enhance polymer blending. Thus, triclosan is considered for a polymer additive with multiple properties to be an antimicrobial with additional benefits as a nonpolar toughening agent and a hydrophobic wetting agent. The triclosan material relationships with alternating ether bond rotations are described through a complete different form of medium by comparisons with known antimicrobial properties that upset bacterial cell membranes through rapid fluctuating mechanomolecular energies. Also, triclosan bond entanglements with secondary bonding can produce structural defects in weak bacterial lipid membranes requiring pliability that can then interfere with cell division. Regarding applications with polymers, triclosan can be incorporated by mixing into a resin system before cure, melt mixed with thermoplastic polymers that set on cooling

  16. Bacteriostatic and bactericidal activities of 24 antimicrobial agents against Campylobacter fetus subsp. jejuni.

    Science.gov (United States)

    Vanhoof, R; Gordts, B; Dierickx, R; Coignau, H; Butzler, J P

    1980-07-01

    The bacteriostatic and bactericidal activities of 24 antimicrobial agents were tested with the Dynatech MIC 2000 system against 86 strains of Campylobacter fetus subsp. jejuni from human sources. The penicillins (penicillin G, ampicillin, amoxycillin, carbenicillin) had poor activity. Ampicillin and amoxycillin were equally active. Cefotaxime revealed a rather good activity. Erythromycin, gentamicin, tobramycin, amikacin, and furazolidone were the most active compounds. Two strains (2.3%) were resistant to erythromycin. One strain (1.2%) was completely resistant to tobramycin. The tetracyclines (tetracyline, doxycycline, minocycline) were generally effective, but 8% of the strains were totally resistant to them. Minocycline was the most active. Chloramphenicol, thiamphenicol, and clindamycin had good activity. The bacteriostatic and bactericidal distributions for colistin, nalidixic acid, and metronidazole were broad.

  17. Subinhibitory concentrations of triclosan promote Streptococcus mutans biofilm formation and adherence to oral epithelial cells.

    Directory of Open Access Journals (Sweden)

    Telma Blanca Lombardo Bedran

    Full Text Available Triclosan is a general membrane-active agent with a broad-spectrum antimicrobial activity that is commonly used in oral care products. In this study, we investigated the effect of sub-minimum inhibitory concentrations (MICs of triclosan on the capacity of the cariogenic bacterium Streptococcus mutans to form biofilm and adhere to oral epithelial cells. As quantified by crystal violet staining, biofilm formation by two reference strains of S. mutans was dose-dependently promoted, in the range of 2.2- to 6.2-fold, by 1/2 and 1/4 MIC of triclosan. Observations by scanning electron microscopy revealed the presence of a dense biofilm attached to the polystyrene surface. Growth of S. mutans in the presence of triclosan at sub-MICs also increased its capacity to adhere to a monolayer of gingival epithelial cells. The expression of several genes involved in adherence and biofilm formation in S. mutans was investigated by quantitative RT-PCR. It was found that sub-MICs of triclosan significantly increased the expression of comD, gtfC, and luxS, and to a lesser extent of gtfB and atlA genes. These findings stress the importance of maintaining effective bactericidal concentrations of therapeutic triclosan since sub-MICs may promote colonization of the oral cavity by S. mutans.

  18. Subinhibitory concentrations of triclosan promote Streptococcus mutans biofilm formation and adherence to oral epithelial cells.

    Science.gov (United States)

    Bedran, Telma Blanca Lombardo; Grignon, Louis; Spolidorio, Denise Palomari; Grenier, Daniel

    2014-01-01

    Triclosan is a general membrane-active agent with a broad-spectrum antimicrobial activity that is commonly used in oral care products. In this study, we investigated the effect of sub-minimum inhibitory concentrations (MICs) of triclosan on the capacity of the cariogenic bacterium Streptococcus mutans to form biofilm and adhere to oral epithelial cells. As quantified by crystal violet staining, biofilm formation by two reference strains of S. mutans was dose-dependently promoted, in the range of 2.2- to 6.2-fold, by 1/2 and 1/4 MIC of triclosan. Observations by scanning electron microscopy revealed the presence of a dense biofilm attached to the polystyrene surface. Growth of S. mutans in the presence of triclosan at sub-MICs also increased its capacity to adhere to a monolayer of gingival epithelial cells. The expression of several genes involved in adherence and biofilm formation in S. mutans was investigated by quantitative RT-PCR. It was found that sub-MICs of triclosan significantly increased the expression of comD, gtfC, and luxS, and to a lesser extent of gtfB and atlA genes. These findings stress the importance of maintaining effective bactericidal concentrations of therapeutic triclosan since sub-MICs may promote colonization of the oral cavity by S. mutans.

  19. Triclosan: applications and safety.

    Science.gov (United States)

    Bhargava, H N; Leonard, P A

    1996-06-01

    Triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) is a nonionic, broad spectrum, antimicrobial agent that, because of its favorable safety profile, has been incorporated into a variety of many personal care products, including deodorant soaps, underarm deodorants, shower gels, and health care personnel handwashes. Triclosan exhibits a moderate degree of substantivity to the skin, and, in many products, it imparts a remnant antimicrobial effect. Although direct contact with the material under exaggerated exposure conditions causes dermal irritation in laboratory animals, it has only rarely been associated with skin irritation or sensitization in human being in formulated products. Acute, subacute/subchronic, and chronic toxicity profiles have been established to determine that triclosan is neither an acute oral toxicant nor that it acts as a carcinogen, mutagen, or teratogen. A new application for triclosan is in oral dentifrices for plaque control. Currently under investigation in the United States, it is approved for oral care application in Canada and many European countries.

  20. Degradation of Triclosan in aerated sludge

    DEFF Research Database (Denmark)

    Bester, Kai; Chen, Xijuan; Furgal, Karolina

    Triclosan is a bactericide used in increasing shelflife of cosmetics, improving hygenics in sportswear as well as in toothpaste and in mouth wash. More than 350 tons Triclosan is annually produced in Europe, and most of it finally is emitted into wastewater at the end of its life cycle. Therefore......, the fate of this compound in wastewater treatment is of high interest, especially as triclosan has detrimental effects on, e.g., micro-algae at very low concentrations.  It has been demonstrated, that the elimination of triclosan is very effective in wastewater treatment with eliminination rates > 90......%. However, a persistent transformation product (triclosan-methyl) is beeing formed in the activated sludge treatment process. In contrast to other studies, mass balances on wastewater treatment plants show that the fate of more than 50% of the incoming triclosan remains unknown. In this study we...

  1. Degradation of Triclosan in aerated sludge

    DEFF Research Database (Denmark)

    Bester, Kai; Chen, Xijuan; Furgal, Karolina;

    Triclosan is a bactericide used in increasing shelflife of cosmetics, improving hygenics in sportswear as well as in toothpaste and in mouth wash. More than 350 tons Triclosan is annually produced in Europe, and most of it finally is emitted into wastewater at the end of its life cycle. Therefore......, the fate of this compound in wastewater treatment is of high interest, especially as triclosan has detrimental effects on, e.g., micro-algae at very low concentrations.  It has been demonstrated, that the elimination of triclosan is very effective in wastewater treatment with eliminination rates > 90......%. However, a persistent transformation product (triclosan-methyl) is beeing formed in the activated sludge treatment process. In contrast to other studies, mass balances on wastewater treatment plants show that the fate of more than 50% of the incoming triclosan remains unknown. In this study we...

  2. A shape memory foam composite with enhanced fluid uptake and bactericidal properties as a hemostatic agent.

    Science.gov (United States)

    Landsman, T L; Touchet, T; Hasan, S M; Smith, C; Russell, B; Rivera, J; Maitland, D J; Cosgriff-Hernandez, E

    2017-01-01

    Uncontrolled hemorrhage accounts for more than 30% of trauma deaths worldwide. Current hemostatic devices focus primarily on time to hemostasis, but prevention of bacterial infection is also critical for improving survival rates. In this study, we sought to improve on current devices used for hemorrhage control by combining the large volume-filling capabilities and rapid clotting of shape memory polymer (SMP) foams with the swelling capacity of hydrogels. In addition, a hydrogel composition was selected that readily complexes with elemental iodine to impart bactericidal properties to the device. The focus of this work was to verify that the advantages of each respective material (SMP foam and hydrogel) are retained when combined in a composite device. The iodine-doped hydrogel demonstrated an 80% reduction in bacteria viability when cultured with a high bioburden of Staphylococcus aureus. Hydrogel coating of the SMP foam increased fluid uptake by 19× over the uncoated SMP foam. The composite device retained the shape memory behavior of the foam with more than 15× volume expansion after being submerged in 37°C water for 15 min. Finally, the expansion force of the composite was tested to assess potential tissue damage within the wound during device expansion. Expansion forces did not exceed 0.6N, making tissue damage during device expansion unlikely, even when the expanded device diameter is substantially larger than the target wound site. Overall, the enhanced fluid uptake and bactericidal properties of the shape memory foam composite indicate its strong potential as a hemostatic agent to treat non-compressible wounds.

  3. Triclosan: a safety profile.

    Science.gov (United States)

    DeSalva, S J; Kong, B M; Lin, Y J

    1989-09-01

    Triclosan (2, 4, 4'-trichloro-2'-hydroxydiphenyl ether), an antimicrobial agent, has been used extensively for 20 years in consumer products, principally in deodorants, soaps and other dermatological preparations. Recently, the use of triclosan has been extended to oral health care products such as dentifrices. This paper reviews safety information, both pre-clinical and clinical studies, from the literature, data submitted to the Antimicrobial I OTC Review Panel and unpublished work from the Pharmacology and Toxicology Department of the Colgate-Palmolive Company. The data spans acute, subacute, subchronic and chronic toxicity; mutagenicity, carcinogenicity, reproduction/teratology and pharmacokinetics. Results of these studies show that triclosan is well tolerated by a variety of species including man. In clinical studies with triclosan in solutions and dentifrices, a steady state was reached by day 7 with blood levels in the parts per billion (ppb) range and urine as the main route of excretion. Based on these studies, triclosan can be considered safe for use in dentifrice and mouthrinse products.

  4. Influence of fluoride- or triclosan-based desensitizing agents on adhesion of resin cements to dentin.

    Science.gov (United States)

    Dündar, Mine; Cal, Ebru; Gökçe, Bülent; Türkün, Murat; Ozcan, Mutlu

    2010-10-01

    Effect of desensitizers on the bond strength of resin cements to dentin was evaluated. Intact premolars (N = 90) were embedded in polymethyl methacrylate; dentin surfaces were exposed, and they were randomly divided into two main groups of cements (Duolink (D), Variolink II (V); n = 45 per group) and then into three desensitizer subgroups (n = 15 per subgroup). Teeth in controls (C) were treated according to cements' adhesion protocols; the other two groups received either fluoride- [Aqua-Prep F (F)] or triclosan-based [Seal&Protect (T)] desensitizers. Ceramic disks (Empress 2) were adhered; specimens were thermocycled (×5,000 cycles, 5-55 ± 1°C, dwell time 30 s) and subjected to shear bond strength test (MPa ± SD) in a universal testing machine (crosshead speed 1 mm/min). Failure types were classified using scanning electron microscope. For V, application of both desensitizers (29.6 ± 7.8 and 22.8 ± 2.8 for F and T, respectively) did not present significantly different results than that of the VC (21.2 ± 2.3; p > 0.05, one-way ANOVA). In D, F (20.6 ± 2.4) showed significantly higher results (p types.

  5. The antimicrobial agents triclocarban and triclosan as potent modulators of reproduction in Potamopyrgus antipodarum (Mollusca: Hydrobiidae).

    Science.gov (United States)

    Geiß, Cornelia; Ruppert, Katharina; Heidelbach, Tanja; Oehlmann, Jörg

    2016-11-09

    In this study, we assessed the chronic effects of the two antimicrobial substances triclocarban (TCC) and triclosan (TCS) on reproduction of a mollusk species by using the reproduction test with the New Zealand mudsnail Potamopyrgus antipodarum. Snails coming from a laboratory culture were exposed for 28 days to nominal concentrations ranging from 0.1 up to 10 µg/L for both chemicals (measured 0.082-8.85 µg TCC/L; 0.068-6.26 µg TCS/L). At the end of the experiment, snails were dissected and embryos in the brood pouch were counted to assess the individualized reproductive success of adult snails. Exposure to TCC resulted in an inverted u-shaped concentration-response relationship, with a stimulation of reproduction at low concentrations followed by an inhibition at higher concentrations. The no observed effect concentration (NOEC) and the lowest observed effect concentration (LOEC) were 0.082 and 0.287 µg/L, respectively. TCS caused significantly increased embryo numbers at all tested concentrations, except in the group of 0.170 µg/L. Therefore, the NOEC for TCS was 0.170 µg/L and the LOEC was 0.660 µg/L. These results indicate that TCC and TCS may cause reproductive effects at environmentally relevant concentrations indicating a potential risk for aquatic organisms in the environment.

  6. Bactericide Effect of Silver Nanoparticles as a Final Irrigation Agent in Endodontics on Enterococcus faecalis: An Ex Vivo Study

    Directory of Open Access Journals (Sweden)

    Pedro-IV González-Luna

    2016-01-01

    Full Text Available The objective of this study was to determine the bactericidal effect of silver nanoparticles as a final irrigation agent in endodontics. This study included 120 uniradicular extracted dental organs inoculated with Enterococcus faecalis (E. faecalis and organized into 4 groups: (A 30 teeth irrigated with a dispersion of silver nanoparticles (537 μg/mL; (B 30 teeth irrigated with a sodium hypochlorite solution (2.25%; (C 30 teeth irrigated with a dispersion of silver nanoparticles (537 μg/mL + EDTA (17%; and (D 30 teeth with a saline solution. After the irrigation protocol, the samples were analyzed through a spectrophotometer to measure the bactericidal effect and scanning electron microscope and atomic force microscope in order to observe the presence of dental smear layer. The results showed that nanoparticles of 10 nm and the sodium hypochlorite at 2.25% were effective for eliminating E. faecalis, with no significant difference between them.

  7. Fate of flame retardants and the antimicrobial agent triclosan in planted and unplanted biosolid-amended soils.

    Science.gov (United States)

    Davis, Elizabeth F; Gunsch, Claudia K; Stapleton, Heather M

    2015-05-01

    A comprehensive understanding of the fate of contaminant-laden biosolids is needed to fully evaluate the environmental impacts of biosolid land application. The present study examined the fate of several flame retardants and triclosan in biosolid-amended soil in a 90-d greenhouse experiment. Objectives included evaluating the persistence of these compounds in soil, their phytoaccumulation potential by alfalfa (Medicago sativa), and potential degradation reactions. Concentrations of the polybrominated diphenyl ether (PBDE) congeners BDE-47 and BDE-209 and the antimicrobial triclosan declined significantly over time in biosolid-amended soil planted with alfalfa and then reached a steady state by day 28. In contrast, no significant losses of those analytes were observed from soil in nonvegetated pots. The amount of an analyte lost from vegetated soil ranged from 43% for the flame retardant di(2-ethylhexyl)-2,3,4,5-tetrabromophthalate to 61% for triclosan and was significantly and negatively related to the log octanol-water partition coefficient. Alfalfa roots and shoots were monitored for the compounds, but no clear evidence of phytoaccumulation was observed. Methyl triclosan formation was observed in the biosolid-amended soils during the study period, indicating in situ biotransformation of triclosan. The present study demonstrates that, although they are highly recalcitrant, PBDEs, selected alternate brominated flame retardants, and triclosan are capable of undergoing dissipation from biosolid-amended soils in the presence of plants.

  8. [Advances on research of human exposure to triclosan].

    Science.gov (United States)

    Jin, Chenye; Chen, Yiming; Zhang, Peiqi; Xiong, Zhezhen; Wang, Caifeng; Tian, Ying

    2016-03-01

    Triclosan, a broad-spectrum antimicrobial agent, was reported to have been widely detected in various human biological samples such as urine, blood and human milk among foreign populations. In China, limited reports have been found on human exposure to triclosan, and the reported urinary triclosan concentrations were significantly lower than that of American populations. Besides, the potential influencing factors still remain unclear regarding human exposure to triclosan, but evidences suggest that those in middle age and with higher household income and higher social class tend to have higher urinary triclosan concentrations. Furthermore, triclosan exposure tend to differ by sex, geography, heredity, metabolism and life style.

  9. Biodegradation of triclosan and formation of methyl-triclosan in activated sludge under aerobic conditions

    DEFF Research Database (Denmark)

    Chen, Xijuan; Nielsen, Jeppe Lund; Furgal, Karolina

    2011-01-01

    Triclosan is an antimicrobial agent which is widely used in household and personal care products. Widespread use of this compound has led to the elevated concentrations of triclosan in wastewater, wastewater treatment plants (WWTPs) and receiving waters. Removal of triclosan and formation...... of triclosan- methyl was investigated in activated sludge from a standard activated sludge WWTP equipped with enhanced biological phosphorus removal. The removal was found to occur mainly under aerobic conditions while under anoxic (nitrate reducing) and anaerobic conditions rather low removal rates were...... determined. In a laboratory-scale activated sludge reactor 75% of the triclosan was removed under aerobic conditions within 150 h, while no removal was observed under anaerobic or anoxic conditions. One percent of the triclosan was converted to triclosan-methyl under aerobic conditions, less under anoxic...

  10. Effects of triclosan on various aquatic organisms.

    Science.gov (United States)

    Tatarazako, Norihisa; Ishibashi, Hiroshi; Teshima, Kenji; Kishi, Katsuyuki; Arizono, Koji

    2004-01-01

    Triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) is widely used as an antibacterial agent in various industrial products, such as textile goods, soap, shampoo, liquid toothpaste and cosmetics, and often detected in wastewater effluent. However, there is a paucity of data on the toxicity of triclosan and its effects on aquatic organisms. In this study, the acute toxicity of triclosan to the Microtox bacterium (Vibrio fischeri), a microalga (Selenastrum capricornutum), a crustacean (Ceriodaphnia dubia) and fish (Danio rerio and Oryzias latipes) was examined. As a result, the MicrotoxR bacterium, crustacean and fish had similar sensitivities towards triclosan toxicity (i.e., IC25 from 0.07 to 0.29 mg/L triclosan). In contrast, the microalga was about 30-80-fold (IC25 = 0.0034 mg/L triclosan) more sensitive to triclosan toxicity than the bacterium and fish. Therefore, triclosan is quite highly toxic to aquatic animals, and is particularly highly toxic to the green alga used as a test organism in this study. This result indicates that triclosan exerts a marked influence on algae, which are important organisms being the first-step producers in the ecosystem; therefore, the possible destruction of the balance of the ecosystem is expected if triclosan is discharged into the environment at high levels.

  11. Bactericide Effect of Silver Nanoparticles as a Final Irrigation Agent in Endodontics on Enterococcus faecalis: An Ex Vivo Study

    OpenAIRE

    Pedro-IV González-Luna; Gabriel-Alejandro Martínez-Castañón; Norma-Verónica Zavala-Alonso; Nuria Patiño-Marin; Nereyda Niño-Martínez; Javier Morán-Martínez; Jorge-Humberto Ramírez-González

    2016-01-01

    The objective of this study was to determine the bactericidal effect of silver nanoparticles as a final irrigation agent in endodontics. This study included 120 uniradicular extracted dental organs inoculated with Enterococcus faecalis (E. faecalis) and organized into 4 groups: (A) 30 teeth irrigated with a dispersion of silver nanoparticles (537 μg/mL); (B) 30 teeth irrigated with a sodium hypochlorite solution (2.25%); (C) 30 teeth irrigated with a dispersion of silver nanoparticles (537 μg...

  12. Identification of triclosan-degrading bacteria in a triclosan enrichment culture using stable isotope probing.

    Science.gov (United States)

    Lee, Do Gyun; Cho, Kun-Ching; Chu, Kung-Hui

    2014-02-01

    Triclosan, a widely used antimicrobial agent, is an emerging contaminant in the environment. Despite its antimicrobial character, biodegradation of triclosan has been observed in pure cultures, soils and activated sludge. However, little is known about the microorganisms responsible for the degradation in mixed cultures. In this study, active triclosan degraders in a triclosan-degrading enrichment culture were identified using stable isotope probing (SIP) with universally (13)C-labeled triclosan. Eleven clones contributed from active microorganisms capable of uptake the (13)C in triclosan were identified. None of these clones were similar to known triclosan-degraders/utilizers. These clones distributed among α-, β-, or γ-Proteobacteria: one belonging to Defluvibacter (α-Proteobacteria), seven belonging to Alicycliphilus (β-Proteobacteria), and three belonging to Stenotrophomonas (γ-Proteobacteria). Successive additions of triclosan caused a significant shift in the microbial community structure of the enrichment culture, with dominant ribotypes belonging to the genera Alicycliphilus and Defluvibacter. Application of SIP has successfully identified diverse uncultivable triclosan-degrading microorganisms in an activated sludge enrichment culture. The results of this study not only contributed to our understanding of the microbial ecology of triclosan biodegradation in wastewater, but also suggested that triclosan degraders are more phylogenetically diverse than previously reported.

  13. Influence of triclosan and triclocarban antimicrobial agents on the microbial activity in three physicochemically differing soils of south Australia

    Directory of Open Access Journals (Sweden)

    Abid Ali, Muhammad Arshad, Zahir A. Zahir

    2011-11-01

    Full Text Available Antimicrobial agents are being used in numerous consumer and health care products on account of which their annual global consumption has reached in millions of kilograms. They are flushed down the drain and become the part of wastewater and sewage sludge and end up in the ultimate sink of agricultural soils. Once they are in the soil, they may disturb the soil’s ecology as a result of which microbial activity useful for soil fertility and biodegradation of xenobiotics may severely be impacted. The present study was designed to assess the influence of two antimicrobial agents triclosan (TCS and triclocarban (TCC, commonly used in consumer and health care products, on the microbial activity in the three agricultural soils from South Australia having different characteristics. The study was laid out following the two factors factorial design by applying 14C-glucose at 5 µg g-1 with either TCS at 0, 30, 90 and 270 µg g-1 or TCC at 0, 50, 150 and 450 µg g-1 in three agricultural soils, Freeling (Typic Rhodoxeralf–sodic, Booleroo (Typic Rhodoxeralf and Avon (Calcixerralic Xerochrepts. The 14CO2, which was released as a result of microbial respiration, was trapped in 3 mL 1M NaOH and was quantified on Wallac WinSpectral α/β 1414 Liquid Scintillation Counter. The results revealed a significant difference in amounts of 14C-glucose mineralized in the three soils. A significant concentration dependant suppressive effect of TCS on the biomineralization of 14C-glucose appeared in all the tested soils as opposed to TCC where no such concentration dependent effect could be recorded. The reduction in 14C-glucose biomineralization in the Freeling, Booleroo and Avon soils was recorded up to 53.6, 38.5 and 37.4 % by TCS at 270 µg g-1 and 13.0, 5.8 and 1.6 % by TCC at 450 µg g-1 respectively. However, a significant negative correlation of CEC and pH was recorded with TCS and TCC effects. These results may imply that presence of such antimicrobial agents

  14. Antibacterial electrospun nanofibers from triclosan/cyclodextrin inclusion complexes.

    Science.gov (United States)

    Celebioglu, Asli; Umu, Ozgun C O; Tekinay, Turgay; Uyar, Tamer

    2014-04-01

    The electrospinning of nanofibers (NF) from cyclodextrin inclusion complexes (CD-IC) with an antibacterial agent (triclosan) was achieved without using any carrier polymeric matrix. Polymer-free triclosan/CD-IC NF were electrospun from highly concentrated (160% CD, w/w) aqueous triclosan/CD-IC suspension by using two types of chemically modified CD; hydroxypropyl-beta-cyclodextrin (HPβCD) and hydroxypropyl-gamma-cyclodextrin (HPγCD). The morphological characterization of the electrospun triclosan/CD-IC NF by SEM elucidated that the triclosan/HPβCD-IC NF and triclosan/HPγCD-IC NF were bead-free having average fiber diameter of 520 ± 250 nm and 1,100 ± 660 nm, respectively. The presence of triclosan and the formation of triclosan/CD-IC within the fiber structure were confirmed by (1)H-NMR, FTIR, XRD, DSC, and TGA studies. The initial 1:1 molar ratio of the triclosan:CD was kept for triclosan/HPβCD-IC NF after the electrospinning and whereas 0.7:1 molar ratio was observed for triclosan/HPγCD-IC NF and some uncomplexed triclosan was detected suggesting that the complexation efficiency of triclosan with HPγCD was lower than that of HPβCD. The antibacterial properties of triclosan/CD-IC NF were tested against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. It was observed that triclosan/HPβCD-IC NF and triclosan/HPγCD-IC NF showed better antibacterial activity against both bacteria compared to uncomplexed pure triclosan.

  15. Inhibitory and bactericidal action of the biocorrosion agents «INCORGAS» and «AMDOR».

    Science.gov (United States)

    Tsygankova, L E; Vigdorovich, V I; Esina, M N; Nazina, T N; Dubinskaya, E V

    2014-06-01

    Inhibiting action of A, B and M-X compositions against hydrosulfide corrosion of carbon steel, hydrogen diffusion through the steel membrane has been studied along with their bactericidal effect with respect to sulfate-reducing bacteria of Desulfomicrobium type. Bactericidal properties of the compositions have been studied in the Postgate medium. Corrosion tests have been made in the NACE medium saturated by hydrogen sulfide and carbon dioxide separately and together by methods of gravimetrical measurements and linear polarization resistance (LRP). Potentiodynamic polarization and electrochemical diffusion method have been used. Steel protection is determined in the inhibited solutions by combined action of corrosion products film and inhibitor. Presence of sulfate-reducing bacteria in medium increases hydrogen diffusion flux through the steel membrane by 2-3 times and essentially stimulates effect of the inhibitors. The inhibiting compositions decrease quantity of sulfate-reducing bacteria (SRB) by 95-98%. The obtained results testify about predominately bacteriostatic action of the inhibiting compositions, which has influence on the enzymatic systems of SRB cells responsible directly for the sulfate reduction because of substantially decreasing the biogenic hydrogen sulfide concentration in the system.

  16. Antimycobacterial agents differ with respect to their bacteriostatic versus bactericidal activities in relation to time of exposure, mycobacterial growth phase, and their use in combination.

    NARCIS (Netherlands)

    I.A.J.M. Bakker-Woudenberg (Irma); W. van Vianen (Wim); D. van Soolingen (Dick); H.A. Verbrugh (Henri); M.A. Agtmael (Michiel)

    2005-01-01

    textabstractA number of antimycobacterial agents were evaluated with respect to their bacteriostatic activity (growth inhibition) versus the bactericidal activity against a clinical isolate of Mycobacterium avium (Mycobacterium avium complex [MAC] strain 101) in relation to the time of exposure and

  17. Fate of triclosan in agricultural soils after biosolid applications

    Science.gov (United States)

    Triclosan (5-chloro-2-[2,4-dichloro-phenoxy]-phenol (TCS) is a bactericidal compound that is added to a wide variety of household and personal care products. The consumer use of these products releases TCS into urban wastewater and this compound ends up in the environment when agricultural land is ...

  18. Fate of triclocarban and triclosan in soils receiving biosolids applications

    Science.gov (United States)

    Triclosan (5-chloro-2-[2,4-dichloro-phenoxy]-phenol (TCS) and triclocarban (N-(4-chlorophenyl)-N’-(3,4-dichlorophenyl)urea) (TCC) are bactericidal compounds that are added to a wide range of household and personal care products such as hand soap, dish washing products, laundry detergents, cleaning w...

  19. Fate of Triclosan in activated sludge treatment - bridging the missing gap

    DEFF Research Database (Denmark)

    Bester, Kai; Chen, Xijuan; Furgal, Karolina

    Triclosan is a bactericide used in increasing shelflife of cosmetics, improving hygenics in sportswear as well as in toothpaste and in mouth wash. More than 350 tons Triclosan is annually produced in Europe, and most of it finally is emitted into wastewater at the end of its life cycle. Therefore......, the fate of this compound in wastewater treatment is of high interest, especially as triclosan has detrimental effects on, e.g., micro-algae at very low concentrations.  It has been demonstrated, that the elimination of triclosan is very effective in wastewater treatment with eliminination rates > 90......%. However, a persistent transformation product (triclosan-methyl) is beeing formed in the activated sludge treatment process. In contrast to other studies, mass balances on wastewater treatment plants show that the fate of more than 50% of the incoming triclosan remains unknown. In this study we...

  20. Fate of Triclosan in activated sludge treatment - bridging the missing gap

    DEFF Research Database (Denmark)

    Bester, Kai; Chen, Xijuan; Furgal, Karolina;

    Triclosan is a bactericide used in increasing shelflife of cosmetics, improving hygenics in sportswear as well as in toothpaste and in mouth wash. More than 350 tons Triclosan is annually produced in Europe, and most of it finally is emitted into wastewater at the end of its life cycle. Therefore......, the fate of this compound in wastewater treatment is of high interest, especially as triclosan has detrimental effects on, e.g., micro-algae at very low concentrations.  It has been demonstrated, that the elimination of triclosan is very effective in wastewater treatment with eliminination rates > 90......%. However, a persistent transformation product (triclosan-methyl) is beeing formed in the activated sludge treatment process. In contrast to other studies, mass balances on wastewater treatment plants show that the fate of more than 50% of the incoming triclosan remains unknown. In this study we...

  1. Effects of growth substrate on triclosan biodegradation potential of oxygenase-expressing bacteria.

    Science.gov (United States)

    Lee, Do Gyun; Chu, Kung-Hui

    2013-11-01

    Triclosan is an antimicrobial agent, an endocrine disrupting compound, and an emerging contaminant in the environment. This is the first study investigating triclosan biodegradation potential of four oxygenase-expressing bacteria: Rhodococcus jostii RHA1, Mycobacterium vaccae JOB5, Rhodococcus ruber ENV425, and Burkholderia xenovorans LB400. B. xenovorans LB400 and R. ruber ENV425 were unable to degrade triclosan. Propane-grown M. vaccae JOB5 can completely degrade triclosan (5 mg L(-1)). R. jostii RHA1 grown on biphenyl, propane, and LB medium with dicyclopropylketone (DCPK), an alkane monooxygenase inducer, was able to degrade the added triclosan (5 mg L(-1)) to different extents. Incomplete degradation of triclosan by RHA1 is probably due to triclosan product toxicity. The highest triclosan transformation capacity (Tc, defined as the amount of triclosan degraded/the number of cells inactivated; 5.63×10(-3) ng triclosan/16S rRNA gene copies) was observed for biphenyl-grown RHA1 and the lowest Tc (0.20×10(-3) ng-triclosan/16S rRNA gene copies) was observed for propane-grown RHA1. No triclosan degradation metabolites were detected during triclosan degradation by propane- and LB+DCPK-grown RHA1. When using biphenyl-grown RHA1 for degradation, four chlorinated metabolites (2,4-dichlorophenol, monohydroxy-triclosan, dihydroxy-triclosan, and 2-chlorohydroquinone (a new triclosan metabolite)) were detected. Based on the detected metabolites, a meta-cleavage pathway was proposed for triclosan degradation.

  2. Triclosan antimicrobial polymers

    OpenAIRE

    Petersen, Richard C.

    2016-01-01

    Triclosan antimicrobial molecular fluctuating energies of nonbonding electron pairs for the oxygen atom by ether bond rotations are reviewed with conformational computational chemistry analyses. Subsequent understanding of triclosan alternating ether bond rotations is able to help explain several material properties in Polymer Science. Unique bond rotation entanglements between triclosan and the polymer chains increase both the mechanical properties of polymer toughness and strength that are ...

  3. Preparation and release study of Triclosan in polyethylene/Triclosan anti-bacterial blend.

    Science.gov (United States)

    Kamalipour, Jamshid; Masoomi, Mahmood; Khonakdar, Hossein Ali; Razavi, Seyed Mohammad Reza

    2016-09-01

    In this study, medium density polyethylene (MDPE) incorporated with Triclosan antibacterial substance has been prepared and Triclosan release rate was investigated. The crystallinity level and matrix polarity, as two significant parameters in antibacterial release control, were studied. Triclosan, a well-established widespread antibacterial agent, was incorporated into medium density polyethylene (MDPE) and Maleic anhydride grafted polyethylene (PE-g-MA) was used to change the polarity of the MDPE matrix. A masterbatch of 10wt% Triclosan incorporated with the MDPE and various PE-g-MA concentrations were prepared using an internal mixer. Then the masterbatch was diluted in the MDPE matrix to produce compounds with 0.1, 0.5, and1wt% Triclosan via twin screw extruder. The compounds were molded by compression molding method and then were cooled in three different cooling rate methods: isothermal cooling (I), quenching (Q),and moderate 5-10°C/min cooling rate (M). Cooling rate effects on crystallinity level were investigated applying sample density measurement. UV-vis absorption spectroscopy was used to probe the release of Triclosan. Antibacterial properties of the compounds against Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus were measured. The results showed that by addition of PE-g-MA, Triclosan release rate was increased. It was confirmed that the sample crystallinity was decreased by the cooling rate enhancement. The results also showed that quenched samples indicated higher release of Triclosan. Cooling rate reduction and raising the polarity increased the release of Triclosan and improved the antibacterial properties of the compounds.

  4. Removal and reductive dechlorination of triclosan by Chlorella pyrenoidosa.

    Science.gov (United States)

    Wang, Shujuan; Wang, Xian; Poon, Karen; Wang, Yini; Li, Shangfu; Liu, Hongxia; Lin, Shuhai; Cai, Zongwei

    2013-09-01

    Triclosan that is widely used as antimicrobial agent has been detected as contaminant in various aquatic environments. In this work, removal and biodegradation of triclosan in water by using a ubiquitous green alga, Chlorella pyrenoidosa was investigated. When C. pyrenoidosa was exposed to a series concentration of triclosan from 100 to 800ngmL(-1), more than 50% of triclosan was eliminated by algal uptake from the culture medium during the first 1h exposure and reached equilibrium after the 6h treatment. In the biodegradation experiments, a removal percentage of 77.2% was obtained after C. pyrenoidosa was cultivated with 800ngmL(-1) triclosan for 96h. A major metabolite from the reductive dechlorination of triclosan was identified by using liquid chromatography coupled with electrospray ionization-mass spectrometry. The ultrastructural morphology of algal cells grown in the presence of triclosan was observed by using transmission electron microscopy and the growth of algal cells was detected. It was found that the trilcosan treatment resulted in the disruption of the chloroplast and the release of organic material into aquatic environment, which indicated that triclosan may affect membrane metabolism.

  5. Conformations and intermolecular interactions pattern in solid chloroxylenol and triclosan (API of anti-infective agents and drugs). A (35)Cl NQR, (1)H-(14)N NQDR, X-ray and DFT/QTAIM study.

    Science.gov (United States)

    Latosińska, J N; Latosińska, M; Tomczak, M A; Seliger, J; Zagar, V; Maurin, J K

    2012-02-01

    Two antibacterial and antifungal agents, chloroxylenol (4-chloro-3,5-dimethyl-phenol) and triclosan (5-chloro-2-(2',4'-dichlorophenoxy)-phenol), were studied experimentally in solid state with an X-ray, (35)Cl-nuclear quadrupole resonance (NQR) and (17)O-nuclear quadrupole double resonance (NQDR) spectroscopies and, theoretically, with the density functional theory/quantum theory of atoms in molecules (DFT/QTAIM). The crystallographic structure of triclosan, which crystallises in space group P31 with one molecule in the asymmetric unit [a = 12.64100(10), b = 12.64100(10), c = 6.71630(10) Å], was solved with an X-ray and refined to a final R-factor of 2.81% at room temperature. The NQR frequencies of (35)Cl and (17)O were detected with the help of the density functional theory (DFT) assigned to particular chlorine and oxygen sites in the molecules of both compounds. The NQR frequencies at (35)Cl sites in chloroxylenol and triclosan were found to be more differentiated than frequencies at the (17)O site. The former better describes the substituent withdrawing effects connected to π-electron delocalization within the benzene rings and the influence of temperature; whereas, those at the (17)O site provide more information on O-H bond and intermolecular interactions pattern. The conformation adopted by diphenyl ether of triclosan in solid state was found to be typical of diphenyl ethers, but the opposite to those adopted when it was bound to different inhibitors. According to an X-ray study, temperature had no effect on the conformation of the diphenyl ring of triclosan, which was the same at 90 K and at room temperature (RT). The scattering of NQR frequencies reproduced by the DFT under assumption of the X-ray data at 90 K and RT is found to be a good indicator of the quality of resolution of the crystallographic structure.

  6. Triclosan affects the microbial community in simulated sewage-drain-field soil and slows down xenobiotic degradation

    Energy Technology Data Exchange (ETDEWEB)

    Svenningsen, Hanne [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark); Department of Biology, University of Copenhagen, Solvgade 83H, DK-1307 Copenhagen K (Denmark); Henriksen, Trine [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark); Prieme, Anders [Department of Biology, University of Copenhagen, Solvgade 83H, DK-1307 Copenhagen K (Denmark); Johnsen, Anders R., E-mail: arj@geus.dk [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark)

    2011-06-15

    Effects of the common antibacterial agent triclosan on microbial communities and degradation of domestic xenobiotics were studied in simulated sewage-drain-field soil. Cultivable microbial populations decreased 22-fold in the presence of 4 mg kg{sup -1} of triclosan, and triclosan-resistant Pseudomonas strains were strongly enriched. Exposure to triclosan also changed the general metabolic profile (Ecoplate substrate profiling) and the general profile (T-RFLP) of the microbial community. Triclosan degradation was slow at all concentrations tested (0.33-81 mg kg{sup -1}) during 50-days of incubation. Mineralization experiments ({sup 14}C-tracers) and chemical analyses (LC-MS/MS) showed that the persistence of a linear alkylbenzene sulfonate (LAS) and a common analgesic (ibuprofen) increased with increasing triclosan concentrations (0.16-100 mg kg{sup -1}). The largest effect was seen for LAS mineralization which was severely reduced by 0.16 mg kg{sup -1} of triclosan. Our findings indicate that environmentally realistic concentrations of triclosan may affect the efficiency of biodegradation in percolation systems. - Highlights: > Triclosan may enter the soil environment through sewage. > Triclosan impacts the microbial community in sewage-drain-field soil. > Triclosan-resistant pseudomonads are strongly enriched. > Degradation of co-occurring LAS and ibuprofen is reduced. - Environmentally realistic triclosan concentrations in percolation systems may reduce the biodegradation of other xenobiotics and select for triclosan-resistant bacteria.

  7. Biodegradation of pesticide triclosan by A. versicolor in simulated wastewater and semi-synthetic media.

    Science.gov (United States)

    Ertit Taştan, Burcu; Dönmez, Gönül

    2015-02-01

    Triclosan is known as an antimicrobial agent, a powerful bacteriostat and an important pesticide. In this paper biodegradation of triclosan by Aspergillus versicolor was investigated. Effects of simulated wastewater and semi-synthetic media on fungal triclosan degradation process were detected. HPLC analysis showed that fungal triclosan biodegradation yield was 71.91% at about 7.5 mg/L concentration in semi-synthetic medium and was 37.47% in simulated wastewater. Fungus could be able to tolerate the highest triclosan concentration (15.69 mg/L). The biodegradation yield was 29.81% and qm was 2.22 mg/g at this concentration. Some of the parameters, such as pH, culture media, increasing triclosan and biomass concentrations were optimized in order to achieve the effective triclosan biodegradation process. The highest triclosan biodegradation yields of all microorganisms were achieved by A. versicolor.

  8. Surface plasmon resonance-induced photoactivation of gold nanoparticles as bactericidal agents against methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Mocan, Lucian; Ilie, Ioana; Matea, Cristian; Tabaran, Flaviu; Kalman, Ersjebet; Iancu, Cornel; Mocan, Teodora

    2014-01-01

    Systemic infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and other bacteria are responsible for millions of deaths worldwide, and much of this mortality is due to the rise of antibiotic-resistant organisms as a result of natural selection. Gold nanoparticles synthesized using the standard wet chemical procedure were photoexcited using an 808 nm 2 W laser diode and further administered to MRSA bacteria. Flow cytometry, transmission electron microscopy, contrast phase microscopy, and fluorescence microscopy combined with immunochemical staining were used to examine the interaction of the photoexcited gold nano-particles with MRSA bacteria. We show here that phonon-phonon interactions following laser photoexcitation of gold nanoparticles exhibit increased MRSA necrotic rates at low concentrations and short incubation times compared with MRSA treated with gold nanoparticles alone. These unique data may represent a step forward in the study of bactericidal effects of various nanomaterials, with applications in biology and medicine.

  9. Transcriptomic analysis of triclosan-susceptible and -tolerant Escherichia coli O157:H19 in response to triclosan exposure.

    Science.gov (United States)

    Lenahan, Mary; Sheridan, Áine; Morris, Dermot; Duffy, Geraldine; Fanning, Séamus; Burgess, Catherine M

    2014-04-01

    Triclosan is an active agent that is commonly found in biocide formulations which are used by the food industry to control microbial contamination. The aim of this study was to use microarray analysis to compare gene expression between a triclosan-susceptible Escherichia coli O157:H19 isolate (minimum inhibitory concentration [MIC] 6.25 μg/ml) and its in vitro generated triclosan-tolerant mutant (MIC >8,000 μg/ml). Gene expression profiling was performed on the wild-type and mutant isogenic pairs after 30 min exposure to the parent MIC for triclosan and an untreated control. Microarray analysis was carried out using the Affymetrix GeneChip E. coli Genome 2.0 Array, and differential expression of genes was analyzed using the pumaDE method in Bioconductor R software. Wild-type gene expression was found to be significantly different from the triclosan-tolerant mutant for a large number of genes, even in the absence of triclosan exposure. Significant differences were observed in the expression of a number of pathway genes involved in metabolism, transport, and chemotaxis. In particular, gene expression in the triclosan-tolerant mutant was highly up-regulated for 33 of 38 genes belonging to the flagellar assembly pathway. The presence of extended flagella in the mutant isolate was confirmed visually by transmission electron microscopy, although no significant difference was observed in the motility of the parent and mutant at low levels of triclosan. Data from this study show that at a transcriptomic level, a triclosan-tolerant E. coli O157:H19 mutant is significantly different from the wild-type strain in a number of different pathways, providing an increased understanding of triclosan tolerance.

  10. Triclosan Computational Conformational Chemistry Analysis for Antimicrobial Properties in Polymers.

    Science.gov (United States)

    Petersen, Richard C

    2015-03-01

    Triclosan is a diphenyl ether antimicrobial that has been analyzed by computational conformational chemistry for an understanding of Mechanomolecular Theory. Subsequent energy profile analysis combined with easily seen three-dimensional chemistry structure models for the nonpolar molecule Triclosan show how single bond rotations can alternate rapidly at a polar and nonpolar interface. Bond rotations for the center ether oxygen atom of the two aromatic rings then expose or hide nonbonding lone-pair electrons for the oxygen atom depending on the polar nature of the immediate local molecular environment. Rapid bond movements can subsequently produce fluctuations as vibration energy. Consequently, related mechanical molecular movements calculated as energy relationships by forces acting through different bond positions can help improve on current Mechanomolecular Theory. A previous controversy reported as a discrepancy in literature contends for a possible bacterial resistance from Triclosan antimicrobial. However, findings in clinical settings have not reported a single case for Triclosan bacterial resistance in over 40 years that has been documented carefully in government reports. As a result, Triclosan is recommended whenever there is a health benefit consistent with a number of approvals for use of Triclosan in healthcare devices. Since Triclosan is the most researched antimicrobial ever, literature meta analysis with computational chemistry can best describe new molecular conditions that were previously impossible by conventional chemistry methods. Triclosan vibrational energy can now explain the molecular disruption of bacterial membranes. Further, Triclosan mechanomolecular movements help illustrate use in polymer matrix composites as an antimicrobial with two new additive properties as a toughening agent to improve matrix fracture toughness from microcracking and a hydrophobic wetting agent to help incorporate strengthening fibers. Interrelated

  11. The impacts of triclosan on anaerobic community structures, function, and antimicrobial resistance.

    Science.gov (United States)

    McNamara, Patrick J; LaPara, Timothy M; Novak, Paige J

    2014-07-01

    Triclosan is a widespread antimicrobial agent that accumulates in anaerobic digesters used to treat the residual solids generated at municipal wastewater treatment plants; there is very little information, however, about how triclosan impacts microbial communities in anaerobic digesters. We investigated how triclosan impacts the community structure, function and antimicrobial resistance genes in lab-scale anaerobic digesters. Previously exposed (to triclosan) communities were amended with 5, 50, and 500 mg/kg of triclosan, corresponding to the median, 95th percentile, and 4-fold higher than maximum triclosan concentration that has been detected in U.S. biosolids. Triclosan amendment caused all of the Bacteria and Archaea communities to structurally diverge from that of the control cultures (based on ARISA). At the end of the experiment, all triclosan-amended Archaea communities had diverged from the control communities, regardless of the triclosan concentration added. In contrast, over time the Bacteria communities that were amended with lower concentrations of triclosan (5 mg/kg and 50 mg/kg) initially diverged and then reconverged with the control community structure. Methane production at 500 mg/kg was nearly half the methane production in control cultures. At 50 mg/kg, a large variability in methane production was observed, suggesting that 50 mg/kg may be a tipping point where function begins to fail in some communities. When previously unexposed communities were exposed to 500 mg triclosan/kg, function was maintained, but the abundance of a gene encoding for triclosan resistance (mexB) increased. This research suggests that triclosan could inhibit methane production in anaerobic digesters if concentrations were to increase and may also select for resistant Bacteria. In both cases, microbial community composition and exposure history alter the influence of triclosan.

  12. Removal of triclocarban and triclosan in a wastewater treatment plant and their accumulations onto the solids

    Science.gov (United States)

    The objective of this study was to investigate the fate of Triclosan (5-chloro-2-[2,4-dichloro-phenoxy]-phenol (TCS) and triclocarban (N-(4-chlorophenyl)-N’-(3,4-dichlorophenyl)urea) (TCC) within a wastewater treatment plant (WWTP). TCS and TCC are bactericidal compounds that have been detected in ...

  13. Humic substances-mediated microbial reductive dehalogenation of triclosan

    Science.gov (United States)

    Wang, L.; Xu, S.; Yang, Y.

    2015-12-01

    The role of natural organic matter in regulating the redox reactions as an electron shuttle has received lots of attention, because it can significantly affect the environmental degradation of contaminants and biogeochemical cycles of major elements. However, up to date, limited studies examined the role of natural organic matter in affecting the microbial dehalogenation of emergent organohalides, a critical detoxification process. In this study, we investigated the humic substance (HS)-mediated microbial dehalogenation of triclosan, a widely used antimicrobial agent. We found that the presence of HS stimulated the microbial degradation of triclosan by Shewanella putrefaciens CN-32. In the absence of HS, the triclosan was degraded gradually, achieving 8.6% residual at 8 days. With HS, the residual triclosan was below 2% after 4 days. Cl- was confirmed by ion chromatography analysis, but the dehalogenation processes and other byproducts warrant further investigations. The impact of HS on the degradation of triclosan was highly dependent on the concentration of HS. When the HS was below 15 mg/L, the degradation rate constant for triclosan increased with the organic carbon concentration. Beyond that point, the increased organic carbon concentration decreased the degradation of triclosan. Microbially pre-reduced HS abiotically reduced triclosan, testifying the electron shuttling processes. These results indicate that dissolved organic matter plays a dual role in regulating the degradation of triclosan: it mediates electron transport and inhibits the bioavailability through complexation. Such novel organic matter-mediated reactions for organohalides are important for evaluating the natural attenuation of emergent contaminants and designing cost-effective engineering treatment.

  14. Effects of different culture media on biodegradation of triclosan by Rhodotorula mucilaginosa and Penicillium sp.

    Science.gov (United States)

    Ertit Taştan, Burcu; Özdemir, Caner; Tekinay, Turgay

    Triclosan is an antimicrobial agent and a persistent pollutant. The biodegradation of triclosan is dependent on many variables including the biodegradation organism and the environmental conditions. Here, we evaluated the triclosan degradation potential of two fungi strains, Rhodotorula mucilaginosa and Penicillium sp., and the rate of its turnover to 2,4-dichlorophenol (2,4-DCP). Both of these strains showed less susceptibility to triclosan when grown in minimal salt medium. In order to further evaluate the effects of environmental conditions on triclosan degradation, three different culture conditions including original thermal power plant wastewater, T6 nutrimedia and ammonium mineral salts medium were used. The maximum triclosan degradation yield was 48% for R. mucilaginosa and 82% for Penicillium sp. at 2.7 mg/L triclosan concentration. Biodegradation experiments revealed that Penicillium sp. was more tolerant to triclosan. Scanning electron microscopy micrographs also showed the morphological changes of fungus when cells were treated with triclosan. Overall, these fungi strains could be used as effective microorganisms in active uptake (degradation) and passive uptake (sorption) of triclosan and their efficiency can be increased by optimizing the culture conditions.

  15. Short-term Dynamics and Retention of Triclosan in the Lower Hudson River Estuary

    Science.gov (United States)

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) is a antimicrobial agent present in a wide array of consumer based goods such as soaps, skin creams and dental care products. Triclosan is only partially removed by most wastewater treatment processes, with the remainder being ...

  16. Microbial Resistance to Triclosan: A Case Study in Natural Selection

    Science.gov (United States)

    Serafini, Amanda; Matthews, Dorothy M.

    2009-01-01

    Natural selection is the mechanism of evolution caused by the environmental selection of organisms most fit to reproduce, sometimes explained as "survival of the fittest." An example of evolution by natural selection is the development of bacteria that are resistant to antimicrobial agents as a result of exposure to these agents. Triclosan, which…

  17. Micropollutants in closed life-support systems: the case of triclosan, a biocide excreted via urine

    Science.gov (United States)

    Mastroleo, Felice; Pycke, Benny; Boon, Nico; de Wever, Heleen; Hendrickx, Larissa; Mastroleo, Felice; Wattiez, Ruddy; Mergeay, Max; Verstraete, Willy

    OBJECTIVES: The impact of triclosan on the growth and physiology of the bacterium Rhodospirillum rubrum was studied in the frame of the regenerative life-support system, Micro- Ecological Life Support System Alternative (MELiSSA). A wide range of compounds, such as steroid hormones, pharmaceuticals and personal care products, might enter the life support system via the excrements that are to be treated and recycled. Triclosan was chosen as the first compound to be tested because MELiSSA is a closed system, which is consequently particularly sensitive to compounds inhibiting the microbial metabolism. Because triclosan is increasingly used as an antimicrobial biocide in hygienic formulations (such as toothpaste, mouthwash, deodorants, etc.) and due to its chemical stability, it is considered an emerging pollutant in terrestrial ecosystems. METHODS: In a first phase, the triclosan concentration expected in the life-support system was estimated, the Minimal Inhibitory Concentration (MIC) was determined via plating, and the effect on growth kinetics was assessed by comparing growth parameters in the Gompertz model. In a second phase, the secondary effects of triclosan on cell physiology and gene expression were studied through flow-cytometry and microarray analyses, respectively. RESULTS: Based on the pharmacokinetic data from literature, the predicted concentration range is estimated to be 6-25µg/L triclosan in the Rhodospirillum rubrum compartment of the MELiSSA. The minimal inhibitory concentration of triclosan was determined to be 71 µg/L after 7 days of exposure on Sistrom medium. Upon exposure to 50-200µg/L triclosan, triclosan-resistant mutants of Rhodospirillum rubrum arose spontaneously at high frequency (3.1 ∗ 10 - 4). Analysis of the growth kinetics of the wild-type revealed that triclosan causes an important elongation of the lag-phase and a decrease in growth rate. At concentrations higher than 75mg/L(LD = 500mg/L), triclosan is bactericidal to wild

  18. Triclosan antagonises fluconazole activity against Candida albicans

    OpenAIRE

    2012-01-01

    Epub October 4th Triclosan is a broad-spectrum antimicrobial compound commonly used in oral hygiene products. Investigation of its activity against Candida albicans showed that triclosan was fungicidal at concentrations of 16 mg/L. However, at subinhibitory concentrations (0.5-2 mg/L) triclosan antagonized the activity of fluconazole. Although triclosan induced CDR1 expression in C. albicans, antagonism was still observed in cdr1? and cdr2? strains. Triclosan did not affect fluconazole upt...

  19. Accumulation and Risk of Triclosan in Surface Sediments Near the Outfalls of Municipal Wastewater Treatment Plants.

    Science.gov (United States)

    Chen, Lei; Wang, Zheng; Jing, Zhaoqian; Wang, Zhulai; Cao, Shiwei; Yu, Ting

    2015-10-01

    Triclosan is an antimicrobial agent which is widely used in many personal care products. This toxic chemical is frequently found in the aquatic environment. The municipal wastewater treatment plant (WWTP) effluent has been reported to be one of the major sources for triclosan in the aquatic system. The aim of the present study was to investigate the accumulation of triclosan in the surface sediments near the outfalls of the five major municipal WWTPs of Nanjing, China, as well as to evaluate its potential ecological risk. The concentration of triclosan in the sediment samples ranged from 48.3 to 226 ng/g dry weight, which was well correlated with the acute and genetic toxicity by bioassay. The results suggested that triclosan released from municipal WWTPs could accumulate in the surface sediments nearby and may pose undetermined risk to aquatic organisms.

  20. Bactericidal Activity of Probiotic Agents

    Directory of Open Access Journals (Sweden)

    A.Ye. Abaturov

    2013-12-01

    Full Text Available The article grounds the symbiotic drugs tp inhibit the growth of pathogenic flora, to improve immune status, to enhance the general resistance of the organism to the pathogenic contagions.

  1. In Vitro Oral Biofilm Formation on Triclosan-Coated Sutures in the Absence and Presence of Additional Antiplaque Treatment

    NARCIS (Netherlands)

    Venema, Sebastiaan; Abbas, Frank; van de Belt-Gritter, Betsy; van der Mei, Henny C.; Busscher, Henk J.; van Hoogmoed, Chris G.

    Purpose: This study evaluated the in vitro plaque inhibitory effect of triclosan-coated polyglactin 910 sutures in the absence and presence of an additional antiplaque agent commonly used after oral surgery. Materials and Methods: Triclosan-coated sutures were incubated for 4 hours in freshly

  2. In Vitro Oral Biofilm Formation on Triclosan-Coated Sutures in the Absence and Presence of Additional Antiplaque Treatment

    NARCIS (Netherlands)

    Venema, Sebastiaan; Abbas, Frank; van de Belt-Gritter, Betsy; van der Mei, Henny C.; Busscher, Henk J.; van Hoogmoed, Chris G.

    2011-01-01

    Purpose: This study evaluated the in vitro plaque inhibitory effect of triclosan-coated polyglactin 910 sutures in the absence and presence of an additional antiplaque agent commonly used after oral surgery. Materials and Methods: Triclosan-coated sutures were incubated for 4 hours in freshly collec

  3. Antimicrobial agent triclosan is a proton ionophore uncoupler of mitochondria in living rat and human mast cells and in primary human keratinocytes.

    Science.gov (United States)

    Weatherly, Lisa M; Shim, Juyoung; Hashmi, Hina N; Kennedy, Rachel H; Hess, Samuel T; Gosse, Julie A

    2016-06-01

    Triclosan (TCS) is an antimicrobial used widely in hospitals and personal care products, at ~10 mm. Human skin efficiently absorbs TCS. Mast cells are ubiquitous key players both in physiological processes and in disease, including asthma, cancer and autism. We previously showed that non-cytotoxic levels of TCS inhibit degranulation, the release of histamine and other mediators, from rat basophilic leukemia mast cells (RBL-2H3), and in this study, we replicate this finding in human mast cells (HMC-1.2). Our investigation into the molecular mechanisms underlying this effect led to the discovery that TCS disrupts adenosine triphosphate (ATP) production in RBL-2H3 cells in glucose-free, galactose-containing media (95% confidence interval EC50 = 7.5-9.7 µm), without causing cytotoxicity. Using these same glucose-free conditions, 15 µm TCS dampens RBL-2H3 degranulation by 40%. The same ATP disruption was found with human HMC-1.2 cells (EC50 4.2-13.7 µm), NIH-3 T3 mouse fibroblasts (EC50 4.8-7.4 µm) and primary human keratinocytes (EC50 3.0-4.1 µm) all with no cytotoxicity. TCS increases oxygen consumption rate in RBL-2H3 cells. Known mitochondrial uncouplers (e.g., carbonyl cyanide 3-chlorophenylhydrazone) previously were found to inhibit mast cell function. TCS-methyl, which has a methyl group in place of the TCS ionizable proton, affects neither degranulation nor ATP production at non-cytotoxic doses. Thus, the effects of TCS on mast cell function are due to its proton ionophore structure. In addition, 5 µm TCS inhibits thapsigargin-stimulated degranulation of RBL-2H3 cells: further evidence that TCS disrupts mast cell signaling. Our data indicate that TCS is a mitochondrial uncoupler, and TCS may affect numerous cell types and functions via this mechanism. Copyright © 2015 John Wiley & Sons, Ltd.

  4. Absorption and metabolism of triclosan after application to the skin of B6C3F1 mice.

    Science.gov (United States)

    Fang, Jia-Long; Vanlandingham, Michelle; da Costa, Gonçalo Gamboa; Beland, Frederick A

    2016-05-01

    Triclosan is used as an antimicrobial agent in personal care products, household items, medical devices, and clinical settings. Humans can receive lifelong exposures to triclosan; however, data on the toxicity and carcinogenicity after topical application are lacking. This study determined the absorption, distribution, metabolism, and excretion of triclosan after application to the skin of B6C3F1 mice. [(14)C(U)]triclosan (10 or 100 mg triclosan/kg body weight) was administered topically to mice in two separate experiments: a vehicle selection experiment using propylene glycol, ethanol, and a generic cosmetic cream, and a toxicokinetic experiment. Mice were killed up to 72 h after triclosan administration, and excreta and tissues were analyzed for radioactivity. Ethanol had the best properties of the vehicles evaluated. Maximum absorption was obtained at approximately 12 h after dosing. Radioactivity appeared in the excreta and in all tissues examined, with the highest levels in the gall bladder and the lowest levels in the brain. Triclosan was metabolized to triclosan sulfate, triclosan glucuronide, 2,4-dichlorophenol, and hydroxytriclosan. The metabolite profile was tissue-dependent and the predominant route of excretion was fecal. The AUC(0-∞) and the Cmax of plasma and liver in females were greater than those in males. Slightly lower absorption was observed in mice with Elizabethan collars.

  5. Differential effects of triclosan on the activation of mouse and human peroxisome proliferator-activated receptor alpha.

    Science.gov (United States)

    Wu, Yuanfeng; Wu, Qiangen; Beland, Frederick A; Ge, Peter; Manjanatha, Mugimane G; Fang, Jia-Long

    2014-11-18

    Triclosan is an anti-bacterial agent used in many personal care products, household items, medical devices, and clinical settings. Liver tumors occur in mice exposed to triclosan, a response attributed to peroxisome proliferator-activated receptor alpha (PPARα) activation; however, the effects of triclosan on mouse and human PPARα have not been fully evaluated. We compared the effects of triclosan on mouse and human PPARα using PPARα reporter assays and on downstream events of PPARα activation using mouse hepatoma Hepa1c1c7 cells and human hepatoma HepG2 cells. PPARα transcriptional activity was increased by triclosan in a mouse PPARα reporter assay and decreased in a human PPARα reporter assay. Concentrations of triclosan inhibiting 50% cell growth were similar in both human and mouse hepatoma cells. Western blotting analysis showed that triclosan increased acyl-coenzyme A oxidase (ACOX1), a PPARα target, in Hepa1c1c7 cells but decreased the level in HepG2 cells. Treatment of Hepa1c1c7 cells with triclosan enhanced DNA synthesis and suppressed transforming growth factor beta-mediated apoptosis. This did not occur in HepG2 cells. These data demonstrate that triclosan had similar cytotoxicity in Hepa1c1c7 and HepG2 cells, but differential effects on the activation of PPARα, the expression of ACOX1, and downstream events including DNA synthesis and apoptosis.

  6. Exposure to triclosan augments the allergic response to ovalbumin in a mouse model of asthma.

    Science.gov (United States)

    Anderson, Stacey E; Franko, Jennifer; Kashon, Michael L; Anderson, Katie L; Hubbs, Ann F; Lukomska, Ewa; Meade, B Jean

    2013-03-01

    During the last decade, there has been a remarkable and unexplained increase in the prevalence of asthma. These studies were conducted to investigate the role of dermal exposure to triclosan, an endocrine-disrupting compound, on the hypersensitivity response to ovalbumin (OVA) in a murine model of asthma. Triclosan has had widespread use in the general population as an antibacterial and antifungal agent and is commonly found in consumer products such as soaps, deodorants, toothpastes, shaving creams, mouthwashes, and cleaning supplies. For these studies, BALB/c mice were exposed dermally to concentrations of triclosan ranging from 0.75 to 3% (0.375-1.5mg/mouse/day) for 28 consecutive days. Concordantly, mice were ip injected with OVA (0.9 µg) and aluminum hydroxide (0.5mg) on days 1 and 10 and challenged with OVA (125 µg) by pharyngeal aspiration on days 19 and 27. Compared with the animals exposed to OVA alone, increased spleen weights, OVA-specific IgE, interleukin-13 cytokine levels, and numbers of lung eosinophils were demonstrated when mice were coexposed to OVA and triclosan. Statistically significant increases in OVA-specific and nonspecific airway hyperreactivity were observed for all triclosan coexposed groups compared with the vehicle and OVA controls. In these studies, exposure to triclosan alone was not demonstrated to be allergenic; however, coexposure with a known allergen resulted in enhancement of the hypersensitivity response to that allergen, suggesting that triclosan exposure may augment the allergic responses to other environmental allergens.

  7. Kinetics and mechanism of photolysis and TiO2 photocatalysis of triclosan.

    Science.gov (United States)

    Son, Hyun-Seok; Ko, Gwangpyo; Zoh, Kyung-Duk

    2009-07-30

    The degradations of triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol), a potent broad-spectrum antimicrobial agent, were compared in TiO2-only in the dark condition, photolysis, and TiO2 photocatalysis with a UV-A lamp. TiO2 photocatalysis more effectively degraded and mineralized triclosan compared to TiO2-only and photolysis conditions. While triclosan removed only 30% by TiO2-only condition within 20 min, the triclosan degradation in photolysis and photocatalysis at the same time was 75 and 82%, respectively, and TOC removal was significantly higher in photocatalysis than in photolysis. The data of kinetics showed that triclosan adsorption onto TiO2 was fitted to Langmuir isotherm, and TiO2 photocatalysis was fitted to Langmuir-Hinshelwood model (b=27.99 mM(-1), K(triclosan)=9.49 mM(-1)). The neutral range of pH was favorable to photocatalysis due to the charge effect between TiO2 and triclosan. The addition of 2-propanol, a radical scavenger, significantly reduced the degradation of triclosan both in photolysis and photocatalysis. Dioxin-type intermediates such as dibenzo-dichloro-p-dioxin (DCDD), dibenzo-p-dioxin were produced in photolysis with and without 2-propanol, and also in photocatalysis with 2-propanol, but these intermediates were not detected in photocatalysis without 2-propanol. This result indicates that the photocatalytic degradation of triclosan is mainly achieved by radicals, and these radicals can further degrade dioxin-type intermediates once they are produced in photocatalysis.

  8. Effects of Triclosan on Neural Stem Cell Viability and Survival.

    Science.gov (United States)

    Park, Bo Kyung; Gonzales, Edson Luck T; Yang, Sung Min; Bang, Minji; Choi, Chang Soon; Shin, Chan Young

    2016-01-01

    Triclosan is an antimicrobial or sanitizing agent used in personal care and household products such as toothpaste, soaps, mouthwashes and kitchen utensils. There are increasing evidence of the potentially harmful effects of triclosan in many systemic and cellular processes of the body. In this study, we investigated the effects of triclosan in the survivability of cultured rat neural stem cells (NSCs). Cortical cells from embryonic day 14 rat embryos were isolated and cultured in vitro. After stabilizing the culture, triclosan was introduced to the cells with concentrations ranging from 1 μM to 50 μM and in varied time periods. Thereafter, cell viability parameters were measured using MTT assay and PI staining. TCS decreased the cell viability of treated NSC in a concentration-dependent manner along with increased expressions of apoptotic markers, cleaved caspase-3 and Bax, while reduced expression of Bcl2. To explore the mechanisms underlying the effects of TCS in NSC, we measured the activation of MAPKs and intracellular ROS. TCS at 50 μM induced the activations of both p38 and JNK, which may adversely affect cell survival. In contrast, the activities of ERK, Akt and PI3K, which are positively correlated with cell survival, were inhibited. Moreover, TCS at this concentration augmented the ROS generation in treated NSC and depleted the glutathione activity. Taken together, these results suggest that TCS can induce neurodegenerative effects in developing rat brains through mechanisms involving ROS activation and apoptosis initiation.

  9. Reproductive endocrine-disrupting effects of triclosan: Population exposure, present evidence and potential mechanisms.

    Science.gov (United States)

    Wang, Cai-Feng; Tian, Ying

    2015-11-01

    Triclosan has been used as a broad-spectrum antibacterial agent for over 40 years worldwide. Increasing reports indicate frequent detection and broad exposure to triclosan in the natural environment and the human body. Current laboratory studies in various species provide strong evidence for its disrupting effects on the endocrine system, especially reproductive hormones. Multiple modes of action have been suggested, including disrupting hormone metabolism, displacing hormones from hormone receptors and disrupting steroidogenic enzyme activity. Although epidemiological studies on its effects in humans are mostly negative but conflicting, which is typical of much of the early evidence on the toxicity of EDCs, overall, the evidence suggests that triclosan is an EDC. This article reviews human exposure to triclosan, describes the current evidence regarding its reproductive endocrine-disrupting effects, and discusses potential mechanisms to provide insights for further study on its endocrine-disrupting effects in humans.

  10. Synthesis, Leishmanicidal and Cytotoxic Activity of Triclosan-Chalcone, Triclosan-Chromone and Triclosan-Coumarin Hybrids

    OpenAIRE

    Elver Otero; Sebastián Vergara; Robledo, Sara M.; Wilson Cardona; Miguel Carda; Vélez,Ivan D; Carlos Rojas; Felipe Otálvaro

    2014-01-01

    Twelve hybrids derived from triclosan were obtained via Williamson etherification of O-triclosan alkyl bromide plus chalcone and O-coumarin or O-chromone alkyl bromide plus triclosan, respectively. Structures of the products were elucidated by spectroscopic analysis. The synthesized compounds were evaluated for antileishmanial activity against L. (V) panamensis amastigotes. Cytotoxic activity was also evaluated against mammalian U-937 cells. Compounds 7–9 and 17, were active against Leishmani...

  11. Effects of combined UV and chlorine treatment on chloroform formation from triclosan.

    Science.gov (United States)

    Ben, Weiwei; Sun, Peizhe; Huang, Ching-Hua

    2016-05-01

    The co-exposure to UV irradiation and free chlorine may occur in certain drinking water and wastewater treatment systems. This study investigated the effects of simultaneous low pressure ultraviolet (LPUV) irradiation and free chlorination on the formation of chloroform from triclosan which is a commonly used antibacterial agent. Different treatment systems (i.e., combined UV/chlorine, UV alone, and chlorine alone) were applied to examine the degradation of triclosan and formation of chloroform. The fate of representative intermediates, including chlorinated triclosan, dechlorinated triclosan intermediates and 2,4-dichlorophenol, were tracked to deduce the effect of combined UV/chlorine on the transformation of chloroform formation precursors. The relation between intermediates degradation and chloroform formation was investigated in depth by conducting stepwise experiments with UV and chlorine in different sequences. Results indicate that the combined UV/chlorine notably enhanced the chloroform formation from triclosan. From the reaction mechanism perspective the combined UV/chlorine, where the direct photolysis may play an important role, could accelerate the decay of intermediates and facilitate the generation of productive chloroform precursors. The radicals had modest influence on the degradation of triclosan and intermediates and partly hindered the formation of chloroform. These results emphasize the necessity of considering disinfection by-products formation in the application of combined UV/chlorine technology during water treatment.

  12. Impacts of Triclosan in Greywater on Soil Microorganisms

    Directory of Open Access Journals (Sweden)

    Danielle I. Harrow

    2011-01-01

    Full Text Available The use of greywater for irrigation is becoming a common practice in arid regions such as the Southwestern US, the Middle East, Australia, and China. While greywater supplies nutrients to soil ecosystems, the possible impact of trace contaminants, particularly pharmaceuticals and personal care products, has not been determined. This paper examined the impact of triclosan, an antibacterial agent commonly added to consumer products, on microbial populations and microbial diversity in soil irrigated with greywater. While there was no change in the total number of heterotrophic microorganisms in the soil, both the types and the antibiotic resistance of the microorganisms were significantly influenced by triclosan. The proportion of the microbial isolates resistant to antibiotics increased while at the same time, overall diversity of the microbial community decreased.

  13. Antibiotic Agents

    Science.gov (United States)

    ... agents. A recent survey reported that 76% of liquid soaps from 10 states in the US contained triclosan ... regulated depends upon its intended use and its effectiveness. The US Food and Drug Administration (FDA) regulates antibacterial soaps and antibacterial substances that will either be used ...

  14. Triclosan antagonizes fluconazole activity against Candida albicans.

    LENUS (Irish Health Repository)

    Higgins, J

    2012-01-01

    Triclosan is a broad-spectrum antimicrobial compound commonly used in oral hygiene products. Investigation of its activity against Candida albicans showed that triclosan was fungicidal at concentrations of 16 mg\\/L. However, at subinhibitory concentrations (0.5-2 mg\\/L), triclosan antagonized the activity of fluconazole. Although triclosan induced CDR1 expression in C. albicans, antagonism was still observed in cdr1Δ and cdr2Δ strains. Triclosan did not affect fluconazole uptake or alter total membrane sterol content, but did induce the expression of FAS1 and FAS2, indicating that its mode of action may involve inhibition of fatty acid synthesis, as it does in prokaryotes. However, FAS2 mutants did not exhibit increased susceptibility to triclosan, and overexpression of both FAS1 and FAS2 alleles did not alter triclosan susceptibility. Unexpectedly, the antagonistic effect was specific for C. albicans under hypha-inducing conditions and was absent in the non-filamentous efg1Δ strain. This antagonism may be due to the membranotropic activity of triclosan and the unique composition of hyphal membranes.

  15. Bactericidal micron-thin sol-gel films prevent pin tract and periprosthetic infection.

    Science.gov (United States)

    Qu, Haibo; Knabe, Christine; Burke, Megan; Radin, Shula; Garino, Jonathan; Schaer, Thomas; Ducheyne, Paul

    2014-08-01

    Orthopedic injuries constitute the majority of wounds sustained by U.S. soldiers in recent conflicts. The risk of infection is considerable with fracture fixation devices. In this pilot study, we examined the use of unique bactericidal micron-thin sol-gel films on fracture fixation devices and their ability to prevent and eradicate infections. External fixation was studied with micron-thin sol-gel coated percutaneous pins releasing triclosan and inserted medially into rabbit tibiae. A total of 11 rabbits received percutaneous pins that were either uncoated or sol-gel/triclosan coated. Internal fracture fixation was also studied using sol-gel coated intramedullary (IM) nails releasing vancomycin in the intramedullary tibiae. Six sheep received IM nails that were coated with a sol-gel film that either contained vancomycin or did not contain vancomycin. All animals were challenged with Staphylococcus aureus around the implant. Animals were euthanized at 1 month postoperative. Rabbits receiving triclosan/sol-gel coated percutaneous pins did not show signs of infection. Uncoated percutaneous pins had a significantly higher infection rate. In the sheep study, there were no radiographic signs of osteomyelitis with vancomycin/sol-gel coated IM nails, in contrast to the observations in the control cohort. Hence, the nanostructured sol-gel controlled release technology offers the promise of a reliable and continuous delivery system of bactericidals from orthopedic devices to prevent and treat infection.

  16. Evaluation of Durability to Laundering of Triclosan and Chitosan on a Textile Substrate

    Directory of Open Access Journals (Sweden)

    Anupama Sargur Ranganath

    2014-01-01

    Full Text Available In a hospital environment, textile substrates have been implicated as a vector in the transmission of disease. To mitigate the harmful spread of disease via textile substrates, an effective measure is treatment of textiles with antimicrobial agents. The current investigation compares one of the most widely used chemically synthesized antimicrobial agents, triclosan with chitosan, a naturally occurring antimicrobial agent. For the study, samples of a common polyester/cotton textile used in hospital settings were treated with triclosan and chitosan based antimicrobial agents. Following treatment, the samples were analyzed for their effectiveness against Staphylococcus aureus and Escherichia coli using standard AATCC Test Methods. The efficacy of the treatment to laundering was then evaluated by subjecting the treated samples to 50 washings and repeating the tests against the challenge microorganisms. Data obtained were statistically analyzed at a 95% confidence interval. Results showed that before laundering both triclosan and chitosan treated samples were extremely effective as antimicrobial agents. After laundering, chitosan was less effective against E.coli but maintained efficacy against S. aureus. The effectiveness of triclosan was not adversely affected after the laundering treatments.

  17. Triclosan promotes Staphylococcus aureus nasal colonization.

    Science.gov (United States)

    Syed, Adnan K; Ghosh, Sudeshna; Love, Nancy G; Boles, Blaise R

    2014-04-08

    The biocide triclosan is used in many personal care products, including toothpastes, soaps, clothing, and medical equipment. Consequently, it is present as a contaminant in the environment and has been detected in some human fluids, including serum, urine, and milk. Staphylococcus aureus is an opportunistic pathogen that colonizes the noses and throats of approximately 30% of the population. Colonization with S. aureus is known to be a risk factor for several types of infection. Here we demonstrate that triclosan is commonly found in the nasal secretions of healthy adults and the presence of triclosan trends positively with nasal colonization by S. aureus. We demonstrate that triclosan can promote the binding of S. aureus to host proteins such as collagen, fibronectin, and keratin, as well as inanimate surfaces such as plastic and glass. Lastly, triclosan-exposed rats are more susceptible to nasal colonization with S. aureus. These data reveal a novel factor that influences the ability of S. aureus to bind surfaces and alters S. aureus nasal colonization. IMPORTANCE Triclosan has been used as a biocide for over 40 years, but the broader effects that it has on the human microbiome have not been investigated. We demonstrate that triclosan is present in nasal secretions of a large portion of a test population and its presence correlates with Staphylococcus aureus nasal colonization. Triclosan also promotes the binding of S. aureus to human proteins and increases the susceptibility of rats to nasal colonization by S. aureus. These findings are significant because S. aureus colonization is a known risk factor for the development of several types of infections. Our data demonstrate the unintended consequences of unregulated triclosan use and contribute to the growing body of research demonstrating inadvertent effects of triclosan on the environment and human health.

  18. The impact of antibacterial handsoap constituents on the dynamics of triclosan dissolution from dry sand.

    Science.gov (United States)

    Koehler, Daniel A; Strevett, Keith A; Papelis, Charalambos; Kibbey, Tohren C G

    2017-11-01

    Triclosan has been widely used as an antibacterial agent in consumer and industrial products, and large quantities continue to be discharged to natural waters annually. The focus of this work was on studying the dynamics of triclosan dissolution following evaporative drying. Warm weather can cause the water in intermittent streams or the unsaturated zone to evaporate, causing nonvolatile compounds to form solid precipitates. Because dissolution of precipitates is a relatively slow process, the dynamics of dissolution following evaporation may play an important role in controlling the release of contaminants to the environment. The specific purpose of the work was to explore the effects of surfactant co-contaminants from an industrial antibiotic handsoap on the dissolution dynamics of triclosan. The work used a fiber optic-based optical cell to conduct stirred-batch dissolution experiments for sands coated with different mass loadings of triclosan. Results show that the presence of surfactants from the hand soap not only increase the apparent equilibrium solubility, but also increase the rate of approach to equilibrium. A model describing the dissolution process was developed, and was found to be consistent with experimental data. Results of the work suggest that even small solubility enhancement by surfactant co-contaminants may have a significant impact on dissolution dynamics. Because waters containing significant quantities of triclosan are also among those most likely to contain surfactant co-contaminants, it is likely that the release of triclosan to the environment following evaporation may be faster in many cases than would be predicted from experiments based on pure triclosan. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Triclosan potentiates epithelial-to-mesenchymal transition in anoikis-resistant human lung cancer cells.

    Directory of Open Access Journals (Sweden)

    Thidarat Winitthana

    Full Text Available Alteration of cancer cell toward mesenchymal phenotype has been shown to potentiate tumor aggressiveness by increasing cancer cell metastasis. Herein, we report the effect of triclosan, a widely used antibacterial agent found in many daily products, in enhancing the epithelial-to-mesenchymal transition (EMT in aggressive anoikis resistant human H460 lung cancer cells. EMT has been long known to increase abilities of the cells to increase migration, invasion, and survival in circulating system. The present study reveals that treatment of the cancer cells with triclosan at the physiologically related concentrations significantly increased the colony number of the cancer cells assessed by tumor formation assay. Also, the mesenchymal-like morphology and decrease in cell-to-cell adhesion were observed in triclosan-treated cells. Importantly, western blot analysis revealed that triclosan-treated cells exhibited decreased E-cadherin, while the levels of EMT markers, namely N-cadherin, vimentin, snail and slug were found to be significantly up-regulated. Furthermore, EMT induced by triclosan treatment was accompanied by the activation of focal adhesion kinase/ATP dependent tyrosine kinase (FAK/Akt and Ras-related C3 botulinum toxin substrate 1 (Rac1, which enhanced the ability of the cells to migrate and invade. In conclusion, we demonstrated for the first time that triclosan may potentiate cancer cells survival in detached condition and motility via the process of EMT. As mentioned capabilities are required for success in metastasis, the present study provides the novel toxicological information and encourages the awareness of triclosan use in cancer patients.

  20. Triclosan potentiates epithelial-to-mesenchymal transition in anoikis-resistant human lung cancer cells.

    Science.gov (United States)

    Winitthana, Thidarat; Lawanprasert, Somsong; Chanvorachote, Pithi

    2014-01-01

    Alteration of cancer cell toward mesenchymal phenotype has been shown to potentiate tumor aggressiveness by increasing cancer cell metastasis. Herein, we report the effect of triclosan, a widely used antibacterial agent found in many daily products, in enhancing the epithelial-to-mesenchymal transition (EMT) in aggressive anoikis resistant human H460 lung cancer cells. EMT has been long known to increase abilities of the cells to increase migration, invasion, and survival in circulating system. The present study reveals that treatment of the cancer cells with triclosan at the physiologically related concentrations significantly increased the colony number of the cancer cells assessed by tumor formation assay. Also, the mesenchymal-like morphology and decrease in cell-to-cell adhesion were observed in triclosan-treated cells. Importantly, western blot analysis revealed that triclosan-treated cells exhibited decreased E-cadherin, while the levels of EMT markers, namely N-cadherin, vimentin, snail and slug were found to be significantly up-regulated. Furthermore, EMT induced by triclosan treatment was accompanied by the activation of focal adhesion kinase/ATP dependent tyrosine kinase (FAK/Akt) and Ras-related C3 botulinum toxin substrate 1 (Rac1), which enhanced the ability of the cells to migrate and invade. In conclusion, we demonstrated for the first time that triclosan may potentiate cancer cells survival in detached condition and motility via the process of EMT. As mentioned capabilities are required for success in metastasis, the present study provides the novel toxicological information and encourages the awareness of triclosan use in cancer patients.

  1. Triclosan causes toxic effects to algae in marine biofilms, but does not inhibit the metabolic activity of marine biofilm bacteria.

    Science.gov (United States)

    Johansson, C Henrik; Janmar, Lisa; Backhaus, Thomas

    2014-07-15

    Effects of the antimicrobial agent triclosan to natural periphyton communities (biofilms, comprising primarily microalgae and bacteria) were assessed in two independent experiments during spring and summer. For that purpose a semi-static test system was used in which periphyton was exposed to a concentration range of 5-9054 nmol/L triclosan. Effects on algae were analyzed as content and composition of photosynthetic pigments. The corresponding EC50 values were 39.25 and 302.45 nmol/L for the spring and summer experiment, respectively. Effects on periphytic bacteria were assessed as effects on carbon utilization patterns, using Biolog Ecoplates. No inhibition of either total carbon utilization or functional diversity was observed, indicating a pronounced triclosan tolerance of the marine bacteria. In contrast, a small stimulation of the total carbon utilization was observed at triclosan concentrations exceeding 100 nmol/L. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Identification of methyl triclosan and halogenated analogues in male common carp (Cyprinus carpio) from Las Vegas Bay and semipermeable membrane devices from Las Vegas Wash, Nevada.

    Science.gov (United States)

    Leiker, Thomas J; Abney, Sonja R; Goodbred, Steven L; Rosen, Michael R

    2009-03-01

    Methyl triclosan and four halogenated analogues have been identified in extracts of individual whole-body male carp (Cyprinus carpio) tissue that were collected from Las Vegas Bay, Nevada, and Semipermeable Membrane Devices (SPMD) that were deployed in Las Vegas Wash, Nevada. Methyl triclosan is believed to be the microbially methylated product of the antibacterial agent triclosan (2, 4, 4'-trichloro-4-hydroxydiphenyl ether, Chemical Abstract Service Registry Number 3380-34-5, Irgasan DP300). The presence of methyl triclosan and four halogenated analogues was confirmed in SPMD extracts by comparing low- and high-resolution mass spectral data and Kovats retention indices of methyl triclosan with commercially obtained triclosan that was derivatized to the methyl ether with ethereal diazomethane. The four halogenated analogues of methyl triclosan detected in both whole-body tissue and SPMD extracts were tentatively identified by high resolution mass spectrometry. Methyl triclosan was detected in all 29 male common carp from Las Vegas Bay with a mean concentration of 596 microg kg(-1) wet weight (ww) which is more than an order of magnitude higher than previously reported concentrations in the literature. The halogenated analogs were detected less frequently (21%-76%) and at much lower concentrations (<51 microg kg(-1) ww). None of these compounds were detected in common carp from a Lake Mead reference site in Overton Arm, Nevada.

  3. Identification of methyl triclosan and halogenated analogues in male common carp (Cyprinus carpio) from Las Vegas Bay and semipermeable membrane devices from Las Vegas Wash, Nevada

    Science.gov (United States)

    Leiker, T.J.; Abney, S.R.; Goodbred, S.L.; Rosen, Michael R.

    2009-01-01

    Methyl triclosan and four halogenated analogues have been identified in extracts of individual whole-body male carp (Cyprinus carpio) tissue that were collected from Las Vegas Bay, Nevada, and Semipermeable Membrane Devices (SPMD) that were deployed in Las Vegas Wash, Nevada. Methyl triclosan is believed to be the microbially methylated product of the antibacterial agent triclosan (2, 4, 4'-trichloro-4-hydroxydiphenyl ether, Chemical Abstract Service Registry Number 3380-34-5, Irgasan DP300). The presence of methyl triclosan and four halogenated analogues was confirmed in SPMD extracts by comparing low- and high-resolution mass spectral data and Kovats retention indices of methyl triclosan with commercially obtained triclosan that was derivatized to the methyl ether with ethereal diazomethane. The four halogenated analogues of methyl triclosan detected in both whole-body tissue and SPMD extracts were tentatively identified by high resolution mass spectrometry. Methyl triclosan was detected in all 29 male common carp from Las Vegas Bay with a mean concentration of 596????g kg- 1 wet weight (ww) which is more than an order of magnitude higher than previously reported concentrations in the literature. The halogenated analogs were detected less frequently (21%-76%) and at much lower concentrations (< 51????g kg- 1 ww). None of these compounds were detected in common carp from a Lake Mead reference site in Overton Arm, Nevada.

  4. The effects of Triclosan on the Male Reproductive System of the Rat

    Science.gov (United States)

    Triclosan (TCS), a widely used antibacterial agent, has been shown to have endocrine disrupting activity in mammals. Although the majority of these studies report that TCS alters thyroid hormones, effects on the estrogenic and androgenic pathways have also been observed. These ...

  5. Triclosan enhances the uterine response to ethynyl estradiol: A dose response evaluation in the weanling rat

    Science.gov (United States)

    Triclosan (TCS) is an antimicrobial agent found in personal care products, such as soaps and toothpaste. TCS has been detected in human breast milk, blood and urine and has been reported to decrease thyroxine and testosterone in rats; thus, rising concerns that this endocrine dis...

  6. The Effects of Oral Triclosan Exposure on Reproductive Endpoints in the Female Wistar Rat.

    Science.gov (United States)

    Triclosan (TCS) is an antimicrobial agent commonly found in household personal care and consumer products such as soaps, toothpaste and kitchen utensils. Measurable amounts of TCS have been detected in human blood, urine, and breast milk. Recently, we and others have demonstrated...

  7. Temporal Trends of Triclosan in Sediment Cores Collected from Two Urbanized Estuaries

    Science.gov (United States)

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) is a antimicrobial agent present in a wide array of consumer based goods such as soaps, skin creams and dental care products. It has also been incorporated into consumer textiles and plastics due to its effectiveness as a bioci...

  8. Prenatal Triclosan Exposure and Anthropometric Measures Including Anogenital Distance in Danish Infants

    DEFF Research Database (Denmark)

    Lassen, Tina Harmer; Frederiksen, Hanne; Kyhl, Henriette Boye

    2016-01-01

    BACKGROUND: Triclosan (TCS) is widely used as an antibacterial agent in consumer products such as hand soap and toothpaste, and human exposure is widespread. TCS is suspected of having endocrine-disrupting properties, but few human studies have examined the developmental effects of prenatal TCS......, Swan SH, Main KM, Andersson AM, Lind DV, Husby S, Wohlfahrt-Veje C, Skakkebæk NE, Jensen TK. 2016. Prenatal triclosan exposure and anthropometric measures including anogenital distance in Danish infants. Environ Health Perspect 124:1261-1268; http://dx.doi.org/10.1289/ehp.1409637....

  9. Identification of Triclosan-O-Sulfate and other transformation products of Triclosan formed by activated sludge.

    Science.gov (United States)

    Chen, Xijuan; Casas, Mònica Escolà; Nielsen, Jeppe Lund; Wimmer, Reinhard; Bester, Kai

    2015-02-01

    Aerobic degradation experiments of Triclosan were performed in activated sludge to identify possible transformation products for this compound. During 7 days, the formation of biotransformation products such as 2,4-Dichlorophenol, 4-Chlorocatechol, 5-Hydroxy-Triclosan and other Monohydroxy-Triclosan derivatives as well as Dihydroxy-Triclosan-derivatives were observed. The structure of 5-Hydroxy-Triclosan was elucidated by NMR data for the first time in sludge degradation experiments. Additionally the production of a hitherto unknown transformation product in sludge, i.e., Triclosan-O-Sulfate was detected. During the incubations, the concentrations of this transformation product changed from zero to 330 μg L(-1). Based on the analysis of the biodegradation products, three types of reactions were identified: 1) chemical scission of ether bond to form phenols and catechols, 2) addition of OH moieties to the aromatic ring, and 3) adding of methyl or sulfate groups to the original hydroxyl group.

  10. Determination of triclosan in foodstuffs.

    Science.gov (United States)

    Sanches-Silva, Ana; Sendón-García, Raquel; López-Hernández, Julia; Paseiro-Losada, Perfecto

    2005-01-01

    A reverse-phase high-performance liquid chromatographic (RP-HPLC) method coupled with an ultraviolet detector was developed to determine triclosan which had migrated into foodstuffs from packaging materials. The method includes extraction with hexane, followed by evaporation to dryness and residue re-dissolution in ACN 90%. Chromatographic separation was performed with a Kromasil 100 C18 column (15 cm x 0.4 cm ID, 5 microm particle size) at 30 degrees C and using ACN and water as mobile phases. Regarding recoveries, good results (higher than 83% and lower than 112%) were obtained for the three representative food matrixes selected (orange juice, chicken breast meat, and Gouda cheese).

  11. Recent Evidence Regarding Triclosan and Cancer Risk

    Directory of Open Access Journals (Sweden)

    Michael T. Dinwiddie

    2014-02-01

    Full Text Available Triclosan is a broad-spectrum antibacterial commonly used in cosmetics, dentifrices, and other consumer products. The compound’s widespread use in consumer products and its detection in breast milk, urine, and serum have raised concerns regarding its potential association with various human health outcomes.  Recent evidence suggests that triclosan may play a role in cancer development, perhaps through its estrogenicity or ability to inhibit fatty acid synthesis. Our aims here are to review studies of human exposure levels, to evaluate the results of studies examining the effects of triclosan on cancer development, and to suggest possible directions for future research.

  12. Current and new strategies for the delivery of antiseptic agents.

    Science.gov (United States)

    Constant, Hélène; Falson, Françoise; Pirot, Fabrice

    2006-07-01

    The present mini-review explores the current methods used for the delivery of antiseptics and topical antimicrobials. Relevance of hand scrub with antiseptic liquid soap (e.g. chlorhexidine, PVP-iodine, triclosan) and alcohol-based hand rub is discussed and compared in terms of bactericidal activity, skin tolerance, and medical staff observance. New strategies for antibacterial delivery focus on the challenge of colloidal drug carrier such as liposomes, micro- and nanoparticles enabling sustained bactericidal effect and effective bacterial targeting.

  13. Hypothesis-driven weight-of-evidence analysis of endocrine disruption potential: a case study with triclosan.

    Science.gov (United States)

    Mihaich, Ellen; Capdevielle, Marie; Urbach-Ross, Daniella; Slezak, Brian

    2017-04-01

    Triclosan is an antimicrobial agent used in a range of consumer products, such as deodorants, oral care, clothing, and household items. As with many consumer products, triclosan can be rinsed down the drain and transported to wastewater treatment plants. While most is eliminated during activated sludge sewage treatment by biodegradation and adsorption, some triclosan enters the aquatic environment and may expose wildlife. Given the potential for exposure to both humans and wildlife, resolving whether triclosan is endocrine active is important due to growing concerns about potential adverse public health and environmental effects of endocrine-disrupting substances. A weight of evidence (WoE) analysis focusing on specific hypotheses related to interaction with estrogen, androgen, and thyroid hormone pathways, and steroidogenesis was applied to triclosan. This WoE procedure involved systematic consideration of each endpoint, focused on screening level studies in the US Endocrine Disruptor Screening Program, as well as those in levels 1 through 5 of the OECD Conceptual Framework. This was followed by a semiquantitative relevance weighting of each endpoint to a given hypothesis to reach scientifically justified conclusions. Use of all relevant and reliable information and consistent observations in multiple studies strengthen support for or against each mode of action hypothesis. Using data from multiple animal species and in vitro systems, this systematic and transparent WoE assessment indicated that triclosan is not acting as an agonist or antagonist within the estrogen, androgen, thyroid, or steroidogenic pathways and is not impacting endocrine pathways as a lead or primary mode of toxicity.

  14. Extracellular signal-regulated kinases 1/2 and Akt contribute to triclosan-stimulated proliferation of JB6 Cl 41-5a cells.

    Science.gov (United States)

    Wu, Yuanfeng; Beland, Frederick A; Chen, Si; Fang, Jia-Long

    2015-08-01

    Triclosan is a broad spectrum anti-bacterial agent widely used in many personal care products, household items, medical devices, and clinical settings. Human exposure to triclosan is mainly through oral and dermal routes. In previous studies, we found that sub-chronic dermal exposure of B6C3F1 mice to triclosan induced epidermal hyperplasia and focal necrosis; however, the mechanisms for these responses remain elusive. In this study, using mouse epidermis-derived JB6 Cl 41-5a cells, we found that triclosan stimulated cell growth in a concentration- and time-dependent manner. Enhanced cell proliferation was demonstrated by a substantial increase in the percentage of BrdU-positive cells, an elevation in the protein levels of cyclin D1 and cyclin A, and a reduction in the protein level of p27(Kip1). Western blotting analysis revealed that triclosan induced the activation of extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinases (JNK), p38, and Akt. Pre-treatment of the cells with PD184352, an inhibitor of the upstream kinase MEK1/2, or with wortmannin, an inhibitor of phosphoinositide 3-kinase, blocked triclosan-mediated phosphorylation of ERK1/2 and Akt, respectively, and substantially suppressed triclosan-stimulated cell proliferation, whereas the JNK inhibitor SP600125 or the p38 inhibitor SB203580 had little to no effect on triclosan-stimulated cell proliferation. The phosphorylation activation of ERK1/2 and Akt was further confirmed on the skin of mice dermally administered triclosan. These data suggest that the activation of ERK1/2 and Akt is involved in triclosan-stimulated proliferation of JB6 Cl 41-5a cells.

  15. Determining the distribution of triclosan and methyl triclosan in estuarine settings.

    Science.gov (United States)

    Pintado-Herrera, Marina G; González-Mazo, Eduardo; Lara-Martín, Pablo A

    2014-01-01

    We have developed a method for the analysis of two sewage-derived contaminants: triclosan (TCS), an antibacterial agent, and methyl triclosan (MTCS), a TCS metabolite. For solid samples (4 g), extraction and cleanup were integrated into the same step using pressurized liquid extraction (PLE) with in-cell-clean-up (1g of florisil). The extraction was performed using dichloromethane at 100 °C, 1500 psi and 3 static extraction cycles of 5 min each. For water samples (100mL), stir bar sorptive extraction-liquid desorption (SBSE-LD) was used. Bars were stirred for 10h and analytes were later desorbed using acetonitrile. Finally, MTCS and a silylated derivative of TCS were determined by gas chromatography-mass spectrometry (GC-MS). Recovery experiments in water and sediments were performed and the results ranged from 67% to 78%. Limits of detection (LODs) were 5 ng L(-1) for TCS and 1 ng L(-1) for MTCS, in water samples, and 0.1 ng g(-1) for TCS and MTCS in solid samples. The method was applied then to determine the levels of these compounds in the estuary of Guadalete River (SW Spain). TCS and MTCS concentrations up to 9.6 ng g(-1) in sediments and 310 ng L(-1) in water were measured. Their distribution was strongly influenced by the presence of wastewater sources, treated and untreated, along the sampling area, where maximum concentrations were detected. Highest values were reached in the water column during low tides as the water volume in the estuary becomes lower.

  16. Mitochondrial toxicity of triclosan on mammalian cells

    Directory of Open Access Journals (Sweden)

    Charmaine Ajao

    2015-01-01

    Full Text Available Effects of triclosan (5-chloro-2′-(2,4-dichlorophenoxyphenol on mammalian cells were investigated using human peripheral blood mono nuclear cells (PBMC, keratinocytes (HaCaT, porcine spermatozoa and kidney tubular epithelial cells (PK-15, murine pancreatic islets (MIN-6 and neuroblastoma cells (MNA as targets. We show that triclosan (1–10 μg ml−1 depolarised the mitochondria, upshifted the rate of glucose consumption in PMBC, HaCaT, PK-15 and MNA, and subsequently induced metabolic acidosis. Triclosan induced a regression of insulin producing pancreatic islets into tiny pycnotic cells and necrotic death. Short exposure to low concentrations of triclosan (30 min, ≤1 μg/ml paralyzed the high amplitude tail beating and progressive motility of spermatozoa, within 30 min exposure, depolarized the spermatozoan mitochondria and hyperpolarised the acrosome region of the sperm head and the flagellar fibrous sheath (distal part of the flagellum. Experiments with isolated rat liver mitochondria showed that triclosan impaired oxidative phosphorylation, downshifted ATP synthesis, uncoupled respiration and provoked excessive oxygen uptake. These exposure concentrations are 100–1000 fold lower that those permitted in consumer goods. The mitochondriotoxic mechanism of triclosan differs from that of valinomycin, cereulide and the enniatins by not involving potassium ionophoric activity.

  17. Bordetella parapertussis Circumvents Neutrophil Extracellular Bactericidal Mechanisms

    Science.gov (United States)

    Gorgojo, Juan; Scharrig, Emilia; Gómez, Ricardo M.; Harvill, Eric T.; Rodríguez, Maria Eugenia

    2017-01-01

    B. parapertussis is a whooping cough etiological agent with the ability to evade the immune response induced by pertussis vaccines. We previously demonstrated that in the absence of opsonic antibodies B. parapertussis hampers phagocytosis by neutrophils and macrophages and, when phagocytosed, blocks intracellular killing by interfering with phagolysosomal fusion. But neutrophils can kill and/or immobilize extracellular bacteria through non-phagocytic mechanisms such as degranulation and neutrophil extracellular traps (NETs). In this study we demonstrated that B. parapertussis also has the ability to circumvent these two neutrophil extracellular bactericidal activities. The lack of neutrophil degranulation was found dependent on the O antigen that targets the bacteria to cell lipid rafts, eventually avoiding the fusion of nascent phagosomes with specific and azurophilic granules. IgG opsonization overcame this inhibition of neutrophil degranulation. We further observed that B. parapertussis did not induce NETs release in resting neutrophils and inhibited NETs formation in response to phorbol myristate acetate (PMA) stimulation by a mechanism dependent on adenylate cyclase toxin (CyaA)-mediated inhibition of reactive oxygen species (ROS) generation. Thus, B. parapertussis modulates neutrophil bactericidal activity through two different mechanisms, one related to the lack of proper NETs-inducer stimuli and the other one related to an active inhibitory mechanism. Together with previous results these data suggest that B. parapertussis has the ability to subvert the main neutrophil bactericidal functions, inhibiting efficient clearance in non-immune hosts. PMID:28095485

  18. Kaempferol, a phytoestrogen, suppressed triclosan-induced epithelial-mesenchymal transition and metastatic-related behaviors of MCF-7 breast cancer cells.

    Science.gov (United States)

    Lee, Geum-A; Choi, Kyung-Chul; Hwang, Kyung-A

    2017-01-01

    As a phytoestrogen, kaempferol is known to play a chemopreventive role inhibiting carcinogenesis and cancer progression. In this study, the influences of triclosan, an anti-bacterial agent recently known for an endocrine disrupting chemical (EDC), and kaempferol on breast cancer progression were examined by measuring their effects on epithelial-mesenchymal transition (EMT) and metastatic-related behaviors of MCF-7 breast cancer cells. Morphological changes of MCF-7 cells were observed, and a wound-healing assay was performed after the treatment of triclosan and kaempferol. The effects of triclosan and kaempferol on protein expression of EMT-related markers such as E-cadherin, N-cadherin, Snail, and Slug and metastasis-related markers such as cathepsin B, D, MMP-2 and -9 were investigated by Western blot assay. In microscopic observations, triclosan (10(-6)M) or E2 (10(-9)M) induced transition to mesenchymal phenotype of MCF-7 cells compared with the control. Co-treatment of ICI 182,780 (10(-8)M), an ER antagonist, or kaempferol (25μM) with E2 or triclosan restored the cellular morphology to an epithelial phenotype. In a wound-healing scratch and a transwell migration assay, triclosan enhanced migration and invasion of MCF-7 cells, but co-treatment of kaempferol or ICI 182,780 reduced the migration and invasion ability of MCF-7 cells to the control level. In addition, kaempferol effectively suppressed E2 or triclosan-induced protein expressions of EMT and metastasis promoting markers. Taken together, triclosan may be a distinct xenoestrogenic EDC to promote EMT, migration, and invasion of MCF-7 breast cancer cells through ER. On the other hand, kaempferol can be an alternative chemopreventive agent to effectively suppress the metastatic behavior of breast cancer induced by an endogenous estrogen as well as exogenous xenoestrogenic compounds including triclosan.

  19. Triclosan's interactions in a biological greywater treatment system

    OpenAIRE

    Weihe, Anne Guri

    2013-01-01

    Triclosan have been tested for inhibition effect on greywater bacteria during four correlated experiments. Greywater LECA filters were added triclosan diluted in methanol in one labscale and one bench-scale experiments. COD values were used to determine differences between filters with and without triclosan addition. Triclosan was also added in two respiration experiments with microbiological evelopment in closed glass bottles. Logging of pressure fall with WTW OxiTop® equipment made it poss...

  20. Biological degradation of triclocarban and triclosan in a soil under aerobic and anaerobic conditions and comparison with environmental fate modelling

    Energy Technology Data Exchange (ETDEWEB)

    Ying Guangguo [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); CSIRO Land and Water, Adelaide Laboratory, PMB2, Glen Osmond SA 5064 (Australia)], E-mail: guang-guo.ying@gig.ac.cn; Yu Xiangyang [CSIRO Land and Water, Adelaide Laboratory, PMB2, Glen Osmond SA 5064 (Australia); Food Safety Research Institute, Jiangsu Academy of Agricultural Sciences, Nanjing 210014 (China); Kookana, Rai S. [CSIRO Land and Water, Adelaide Laboratory, PMB2, Glen Osmond SA 5064 (Australia)

    2007-12-15

    Triclocarban and triclosan are two antimicrobial agents widely used in many personal care products. Their biodegradation behaviour in soil was investigated by laboratory degradation experiments and environmental fate modelling. Quantitative structure-activity relationship (QSAR) analyses showed that triclocarban and triclosan had a tendency to partition into soil or sediment in the environment. Fate modelling suggests that either triclocarban or triclosan 'does not degrade fast' with its primary biodegradation half-life of 'weeks' and ultimate biodegradation half-life of 'months'. Laboratory experiments showed that triclocarban and triclosan were degraded in the aerobic soil with half-life of 108 days and 18 days, respectively. No negative effect of these two antimicrobial agents on soil microbial activity was observed in the aerobic soil samples during the experiments. But these two compounds persisted in the anaerobic soil within 70 days of the experimental period. - Triclocarban and triclosan can be degraded by microbial processes in aerobic soil, but will persist in anaerobic soil.

  1. Enhancing antibacterium and strength of cellulosic paper by coating triclosan-loaded nanofibrillated cellulose (NFC).

    Science.gov (United States)

    Liu, Kai; Chen, Lihui; Huang, Liulian; Ni, Yonghao; Sun, Bo

    2015-03-06

    The nanofibrillated cellulose (NFC) was used as substrates to carry triclosan (TCS), which was then applied as a coating agent for impacting antibacterial property to paper while also improving its strength. The TCS-loaded NFC material was further characterized. UV-vis spectra results showed that a characteristic absorption band at 282 nm was observed, which was attributed to triclosan, confirming its successful loading onto NFC. The antibacterial activity tests indicated that the coated paper exhibited excellent antibacterial activity against Escherichia coli, and the growth inhibition of bacteria (GIB) increased as the loading amount of triclosan coated on paper increased. The GIB can reach 98.7% when the 0.023 g TCS-loaded NFC was coated on paper. Meanwhile, the tensile and tear index of the coated paper increased by 18.0% and 26.4%, respectively compared to the blank paper. Therefore, the triclosan-loaded paper could be potentially used in the medical field. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Consumer products as sources of chemical exposures to children: case study of triclosan.

    Science.gov (United States)

    Ginsberg, Gary L; Balk, Sophie J

    2016-04-01

    Consumer products are often overlooked as sources of children's exposures to toxic chemicals. Various regulatory bodies have developed lists of chemicals of concern that can be found in products contacted by children. However, this information has not been summarized for health practitioners. This review organizes such chemicals and products into four categories, with the antibacterial agent triclosan used to illustrate the potential risks to children from a common ingredient in consumer products. Biomonitoring, house dust, indoor air, and product testing document children's exposures to a wide variety of chemicals. An increasing number of epidemiology studies have shown associations between these exposures and health effects in children. Triclosan is an example of a chemical contained in high contact products (e.g., soaps, lotions, and toothpaste) not necessarily designed for children. Triclosan exposure in children has been associated with increased responsiveness to airway allergens, with it also capable of endocrine disruption. However, the utility and necessity of this chemical in consumer products has not been demonstrated in most cases. Triclosan and the other examples provided show that a changing marketplace with little regulatory oversight of chemical uses can lead to unanticipated exposures and potential health risks to children.

  3. Identification of a gene cluster associated with triclosan catabolism.

    Science.gov (United States)

    Kagle, Jeanne M; Paxson, Clayton; Johnstone, Precious; Hay, Anthony G

    2015-06-01

    Aerobic degradation of bis-aryl ethers like the antimicrobial triclosan typically proceeds through oxygenase-dependent catabolic pathways. Although several studies have reported on bacteria capable of degrading triclosan aerobically, there are no reports describing the genes responsible for this process. In this study, a gene encoding the large subunit of a putative triclosan oxygenase, designated tcsA was identified in a triclosan-degrading fosmid clone from a DNA library of Sphingomonas sp. RD1. Consistent with tcsA's similarity to two-part dioxygenases, a putative FMN-dependent ferredoxin reductase, designated tcsB was found immediately downstream of tcsA. Both tcsAB were found in the midst of a putative chlorocatechol degradation operon. We show that RD1 produces hydroxytriclosan and chlorocatechols during triclosan degradation and that tcsA is induced by triclosan. This is the first study to report on the genetics of triclosan degradation.

  4. Conformational and Vibrational Studies of Triclosan

    Science.gov (United States)

    Özişik, Haci; Bayari, S. Haman; Saǧlam, Semran

    2010-01-01

    The conformational equilibrium of triclosan (5-chloro-2-(2, 4-dichlorophenoxy) phenol) have been calculated using density functional theory (DFTe/B3LYP/6-311++G(d, p)) method. Four different geometries were found to correspond to energy minimum conformations. The IR spectrum of triclosan was measured in the 4000-400 cm-1 region. We calculated the harmonic frequencies and intensities of the most stable conformers in order to assist in the assignment of the vibrational bands in the experimental spectrum. The fundamental vibrational modes were characterized depending on their total energy distribution (TED%) using scaled quantum mechanical (SQM) force field method.

  5. Triclosan Exposure enhances the Uterotrophic Response to Low Doses of Ethinyl Estradiol (EE) in the Female Wistar Rat

    Science.gov (United States)

    Triclosan [TCS; (5-cbloro-2-(2, 4-dichlorophenoxy) phenol)] is an antimicrobial agent commonly found in personal care and sanitizing products, such as soaps, toothpaste and hair products. Recent studies have identified TCS in human breast milk, blood and urine. TCS has also been ...

  6. The effect of triclosan on the uterotrophic response to extended doses of ethinyl estradiol in the weanling rat

    Science.gov (United States)

    Triclosan (TCS), a broad-spectrum antimicrobial agent found in many personal care products, has been detected in humans and has been shown to interact with endocrine systems in rats. We previously reported that TCS potentiated the estrogenic effect of ethinyl estradiol (EE) on u...

  7. Triclosan in Campy-Cefex Agar to aid in Enumeration of Naturally Occurring Campylobacter spp. in Broiler Ceca

    Science.gov (United States)

    Detecting and enumerating Campylobacter from poultry samples can be difficult without highly selective media because of competing microflora. We have found that adding 0.1 µg/ mL of Triclosan, an antibacterial agent, to Bolton enrichment broth prevents overgrowth of non-Campylobacter bacteria and si...

  8. Use of FabV-Triclosan Plasmid Selection System for Efficient Expression and Production of Recombinant Proteins in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Syed A Ali

    Full Text Available Maintenance of recombinant plasmid vectors in host bacteria relies on the presence of selection antibiotics in the growth media to suppress plasmid -free segregants. However, presence of antibiotic resistance genes and antibiotics themselves is not acceptable in several applications of biotechnology. Previously, we have shown that FabV-Triclosan selection system can be used to select high and medium copy number plasmid vectors in E. coli. Here, we have extended our previous work and demonstrated that expression vectors containing FabV can be used efficiently to express heterologous recombinant proteins in similar or better amounts in E. coli host when compared with expression vectors containing β-lactamase. Use of small amount of non-antibiotic Triclosan as selection agent in growth medium, enhanced plasmid stability, applicability in various culture media, and compatibility with other selection systems for multiple plasmid maintenance are noteworthy features of FabV-Triclosan selection system.

  9. Triclosan Exposure Is Associated with Rapid Restructuring of the Microbiome in Adult Zebrafish.

    Directory of Open Access Journals (Sweden)

    Christopher A Gaulke

    Full Text Available Growing evidence indicates that disrupting the microbial community that comprises the intestinal tract, known as the gut microbiome, can contribute to the development or severity of disease. As a result, it is important to discern the agents responsible for microbiome disruption. While animals are frequently exposed to a diverse array of environmental chemicals, little is known about their effects on gut microbiome stability and structure. Here, we demonstrate how zebrafish can be used to glean insight into the effects of environmental chemical exposure on the structure and ecological dynamics of the gut microbiome. Specifically, we exposed forty-five adult zebrafish to triclosan-laden food for four or seven days or a control diet, and analyzed their microbial communities using 16S rRNA amplicon sequencing. Triclosan exposure was associated with rapid shifts in microbiome structure and diversity. We find evidence that several operational taxonomic units (OTUs associated with the family Enterobacteriaceae appear to be susceptible to triclosan exposure, while OTUs associated with the genus Pseudomonas appeared to be more resilient and resistant to exposure. We also found that triclosan exposure is associated with topological alterations to microbial interaction networks and results in an overall increase in the number of negative interactions per microbe in these networks. Together these data indicate that triclosan exposure results in altered composition and ecological dynamics of microbial communities in the gut. Our work demonstrates that because zebrafish afford rapid and inexpensive interrogation of a large number of individuals, it is a useful experimental system for the discovery of the gut microbiome's interaction with environmental chemicals.

  10. Electrostatic accumulation and determination of triclosan in ultrathin carbon nanoparticle composite film electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Amiri, Mandana [Department of Chemistry, Sharif University of Technology, Teheran (Iran, Islamic Republic of); Shahrokhian, Saeed [Department of Chemistry, Sharif University of Technology, Teheran (Iran, Islamic Republic of); Psillakis, Elefteria [Laboratory of Aquatic Chemistry, Department of Environmental Engineering, Technical University of Crete, Polytechnioupolis, 73100 Chania-Crete (Greece); Marken, Frank [Department of Chemistry, University of Bath, Bath BA2 7AY (United Kingdom)]. E-mail: f.marken@bath.ac.uk

    2007-06-12

    A film composed of carbon nanoparticles and poly(diallyldimethylammonium chloride) or CNP-PDDAC is formed in a layer-by-layer deposition process at tin-doped indium oxide (ITO) substrates. Excess positive binding sites within this film in aqueous phosphate buffer at pH 9.5 are quantified by adsorption of iron(III)phthalocyanine tetrasulfonate and indigo carmine. Both anionic redox systems bind with Langmuirian characteristics (K {approx} 10{sup 5} mol{sup -1} dm{sup 3}) and show electrochemical reactivity throughout the film at different thicknesses. Therefore, the electrical conductivity in CNP-PDDAC films is good and the positive binding sites are approximately 140 pmol cm{sup -2} per layer. Structural instability of the CNP-PDDAC film in the presence of high concentrations of iron(III)phthalocyanine tetrasulfonate or indigo carmine is observed. Triclosan, a widely used anti-bacterial and anti-fungal agent, exists in aqueous media at pH 9.5 as a negatively charged chlorinated poly-aromatic phenol. Due to the negative charge, triclosan is readily accumulated into CNP-PDDAC films with an efficiency consistent with that expected for simple electrostatic interaction with the cationic binding sites. Oxidation of bound triclosan occurs at 0.6 V versus SCE in a chemically irreversible process. The CNP-PDDAC film electrode is renewed by rinsing in organic solvent and the triclosan oxidation response is shown to correlate with the triclosan concentration in solution from 0.5 to 50 {mu}M. Applications of the CNP-PDDAC film electrode (or improved versions of it) in analysis or in anodic extraction are proposed.

  11. Effectiveness of triclosan in the management of radiation-induced oral mucositis: A randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Satheeshkumar P

    2010-01-01

    Full Text Available Introduction: Oral care in cancer patients is an important aspect in the quality of life of patients undergoing cancer therpay. Mucositis, trismus, salivary gland dysfunction are the main complications of the cancer therapy, which lead to long-term comlications such as radiation caries, poor oral hygiene and osteoradionecrosis. A timely oral evaluation and intervention in these patients can reduce the severity of the potential complications. Triclosan is an antibacterial agent widely used in periodontal therapy, the effectiveness of triclosan in the management of radiation induced oral mucositis is evaluated here. Aims: 1 To determine the effectiveness of triclosan in the management of radiation-induced oral mucositis. 2 To compare the effectiveness of triclosan mouth rinse with conventional sodium bicarbonate mouth rinse. Materials and Methods: Twenty-four patients who underwent radiation therapy for oral cancer and subsequently developed oral mucositis were included in the study. They were randomly allocated into two groups on noticing grade I mucositis (erythema. The study group was advised to use triclosan mouthwash containing triclosan 0.03% W/V and sodium bicarbonate 2 mg mouth wash for the control group. A weekly follow-up evaluation of body weight, food intake, pain and grading of mucositis were made during the radiation treatment period and post radiation treatment period. Results: Both the groups were statistically identical. All the 24 patients in both the groups passed through grade 3 mucositis on the last day of radiotherapy. However, 10 patients in the control group and only one patient in the study group entered to grade 4 mucositis. A definite change was noticed in the severity of the mucositis, food intake and weight loss. The control group took more than 45 days to resolve while the study group took only less than 28 days. Discussion: The results of the study were evaluated and tried to formulate a hypothesis so as to explain

  12. Evidence of 2,7/2,8-dibenzodichloro-p-dioxin as a photodegradation product of triclosan in water and wastewater samples

    Energy Technology Data Exchange (ETDEWEB)

    Mezcua, Milagros; Gomez, M. Jose; Ferrer, Imma; Aguera, Ana; Hernando, M. Dolores; Fernandez-Alba, Amadeo R

    2004-10-25

    A photodegradation study of triclosan, a commonly used antimicrobial agent, was carried out in order to investigate the formation of dibenzodichlorodioxin as a by-product of photodegradation in various environmental matrices and under different conditions. Deionized water and wastewater samples, spiked at 8 {mu}g/mL with triclosan, were irradiated with natural sunlight. Aliquots of the spiked water samples were taken at different times of irradiation and compounds were isolated from the water samples by solid-phase extraction. Separation and detection of the compounds and degradation products was accomplished by gas chromatography-mass spectrometry. A major photolysis degradation product of triclosan, 2,7/2,8-dibenzodichloro-p-dioxin, was identified in wastewater samples. The photolysis experiment showed the simultaneous disappearance of triclosan and the appearance of the dioxin dependent on the pH and the organic matter content. Furthermore, a pilot survey monitoring for influent and effluent waters from a wastewater treatment plant was carried out. The presence of triclosan in all wastewater samples analyzed was revealed and dioxin was found in 80% of the cases, in influents and effluents, thus indicating its input and persistence through the wastewater treatment process. This represents a major finding since dioxins are more toxic than triclosan. Moreover, the presence of such compounds in wastewaters revealed the immediate need to improve the ''classical'' water treatment techniques, as well as considering limitation in water re-use.

  13. Triclosan Resistance of Pseudomonas aeruginosa PAO1 Is Due to FabV, a Triclosan-Resistant Enoyl-Acyl Carrier Protein Reductase ▿

    OpenAIRE

    Zhu, Lei; Lin, Jinshui; Ma, Jincheng; Cronan, John E.; Wang, Haihong

    2009-01-01

    Triclosan, a very widely used biocide, specifically inhibits fatty acid synthesis by inhibition of enoyl-acyl carrier protein (ACP) reductase. Escherichia coli FabI is the prototypical triclosan-sensitive enoyl-ACP reductase, and E. coli is extremely sensitive to the biocide. However, other bacteria are resistant to triclosan, because they encode triclosan-resistant enoyl-ACP reductase isozymes. In contrast, the triclosan resistance of Pseudomonas aeruginosa PAO1 has been attributed to active...

  14. Bactericidal activity of partially oxidized nanodiamonds.

    Science.gov (United States)

    Wehling, Julia; Dringen, Ralf; Zare, Richard N; Maas, Michael; Rezwan, Kurosch

    2014-06-24

    Nanodiamonds are a class of carbon-based nanoparticles that are rapidly gaining attention, particularly for biomedical applications, i.e., as drug carriers, for bioimaging, or as implant coatings. Nanodiamonds have generally been considered biocompatible with a broad variety of eukaryotic cells. We show that, depending on their surface composition, nanodiamonds kill Gram-positive and -negative bacteria rapidly and efficiently. We investigated six different types of nanodiamonds exhibiting diverse oxygen-containing surface groups that were created using standard pretreatment methods for forming nanodiamond dispersions. Our experiments suggest that the antibacterial activity of nanodiamond is linked to the presence of partially oxidized and negatively charged surfaces, specifically those containing acid anhydride groups. Furthermore, proteins were found to control the bactericidal properties of nanodiamonds by covering these surface groups, which explains the previously reported biocompatibility of nanodiamonds. Our findings describe the discovery of an exciting property of partially oxidized nanodiamonds as a potent antibacterial agent.

  15. Direct comparison of Xpert MTB/RIF assay with liquid and solid mycobacterial culture for quantification of early bactericidal activity

    NARCIS (Netherlands)

    Kayigire, X.A.; Friedrich, S.O.; Venter, A.; Dawson, R.; Gillespie, S.H.; Boeree, M.J.; Heinrich, N.; Hoelscher, M.; Diacon, A.H.; Aarnoutse, R.

    2013-01-01

    The early bactericidal activity of antituberculosis agents is usually determined by measuring the reduction of the sputum mycobacterial load over time on solid agar medium or in liquid culture. This study investigated the value of a quantitative PCR assay for early bactericidal activity determinatio

  16. Standardized comparison of antiseptic efficacy of triclosan, PVP-iodine, octenidine dihydrochloride, polyhexanide and chlorhexidine digluconate.

    Science.gov (United States)

    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.

  17. Synthesis, Leishmanicidal and Cytotoxic Activity of Triclosan-Chalcone, Triclosan-Chromone and Triclosan-Coumarin Hybrids

    Directory of Open Access Journals (Sweden)

    Elver Otero

    2014-08-01

    Full Text Available Twelve hybrids derived from triclosan were obtained via Williamson etherification of O-triclosan alkyl bromide plus chalcone and O-coumarin or O-chromone alkyl bromide plus triclosan, respectively. Structures of the products were elucidated by spectroscopic analysis. The synthesized compounds were evaluated for antileishmanial activity against L. (V panamensis amastigotes. Cytotoxic activity was also evaluated against mammalian U-937 cells. Compounds 7–9 and 17, were active against Leishmania parasites (EC50 = 9.4; 10.2; 13.5 and 27.5 µg/mL, respectively and showed no toxicity toward mammalian cells (>200 µg/mL. They are potential candidates for antileishmanial drug development. Compounds 25–27, were active and cytotoxic. Further studies using other cell types are needed in order to discriminate whether the toxicity shown by these compounds is against tumor or non-tumor cells. The results indicate that compounds containing small alkyl chains show better selectivity indices. Moreover, Michael acceptor moieties may modify both the leishmanicidal activity and cytotoxicity. Further studies are required to evaluate if the in vitro activity against Leishmania panamensis demonstrated here is also observed in vivo.

  18. Synthesis, leishmanicidal and cytotoxic activity of triclosan-chalcone, triclosan-chromone and triclosan-coumarin hybrids.

    Science.gov (United States)

    Otero, Elver; Vergara, Sebastián; Robledo, Sara M; Cardona, Wilson; Carda, Miguel; Vélez, Ivan D; Rojas, Carlos; Otálvaro, Felipe

    2014-08-28

    Twelve hybrids derived from triclosan were obtained via Williamson etherification of O-triclosan alkyl bromide plus chalcone and O-coumarin or O-chromone alkyl bromide plus triclosan, respectively. Structures of the products were elucidated by spectroscopic analysis. The synthesized compounds were evaluated for antileishmanial activity against L. (V) panamensis amastigotes. Cytotoxic activity was also evaluated against mammalian U-937 cells. Compounds 7-9 and 17, were active against Leishmania parasites (EC50=9.4; 10.2; 13.5 and 27.5 µg/mL, respectively) and showed no toxicity toward mammalian cells (>200 µg/mL). They are potential candidates for antileishmanial drug development. Compounds 25-27, were active and cytotoxic. Further studies using other cell types are needed in order to discriminate whether the toxicity shown by these compounds is against tumor or non-tumor cells. The results indicate that compounds containing small alkyl chains show better selectivity indices. Moreover, Michael acceptor moieties may modify both the leishmanicidal activity and cytotoxicity. Further studies are required to evaluate if the in vitro activity against Leishmania panamensis demonstrated here is also observed in vivo.

  19. Characterization and activity of an immobilized antimicrobial peptide containing bactericidal PEG-hydrogel.

    Science.gov (United States)

    Cleophas, Rik T C; Sjollema, Jelmer; Busscher, Henk J; Kruijtzer, John A W; Liskamp, Rob M J

    2014-09-01

    A single step immobilization-polymerization strategy of a highly active antimicrobial peptide into a soft hydrogel network on a poly(ethylene terephthalate) surface using thiol-ene chemistry is described. The bactericidal hydrogel was molecularly characterized via Coomassie and Lowry assay protein staining agents as well as by X-ray photoelectron spectroscopy. The bactericidal activity was established against Staphylococcus aureus and Staphylococcus epidermidis, two bacterial strains commonly associated with biomaterial infections. To gain further insight into the biological stability, the hydrogels were incubated with human serum prior to activity testing without loss of activity. These studies revealed a promising bactericidal hydrogel with good stability under physiological conditions.

  20. 75 FR 76461 - Petition for a Ban on Triclosan; Notice of Availability

    Science.gov (United States)

    2010-12-08

    ... AGENCY Petition for a Ban on Triclosan; Notice of Availability AGENCY: Environmental Protection Agency... authority under various statutes to regulate triclosan. Triclosan is an antimicrobial substance used in... ``pervasive and widespread use'' of triclosan poses significant risks to human health and the environment....

  1. 76 FR 5808 - Petition for a Ban on Triclosan; Notice of Availability; Extension of Comment Period

    Science.gov (United States)

    2011-02-02

    ... AGENCY Petition for a Ban on Triclosan; Notice of Availability; Extension of Comment Period AGENCY... comment. The petition asks EPA to use its authority under various statutes to regulate triclosan. In a... EPA to use its authority under various statutes to regulate triclosan. Triclosan is an...

  2. Effects of Triclosan on Marine Benthic and Epibenthic Organisms

    Science.gov (United States)

    Triclosan is an anti-microbial and anti-bacterial compound that has been widely used since the 1970s in consumer products, such as toothpaste, deodorant, and shampoo. Due to its widespread use, triclosan has been detected in various environmental media including wastewater sludg...

  3. The Evaluation of Teat Dipping Coating Agent for Cow Mastitis Pathogens Bactericidal and Bacteriostatic Test in Vitro%聚维酮碘乳头药浴涂膜剂对奶牛乳房炎致病菌体外抑菌效果评价

    Institute of Scientific and Technical Information of China (English)

    周庆民; 冯万宇; 徐馨; 侯美如; 黄健

    2015-01-01

    This study aims to understand in vitro bacteriostasis effectiveness(MIC and MBC)of the teat dipping coating agent on major pathogens(Escherichia coli, Staphylococcus aureus, Streptococcus agalactiaeand Streptococcus dysgalactiae)andprovideacertainofscientiifcevidence.Utilizing10timesmicrodilutionmethod, we determine in vitro effectiveness of the teat dipping coating agent on clinical isolates strain of the major cows mastitis. In order to compare bacteriostasis effectiveness of the teat dipping coating agent and antibiotics,we design the control group-ceftiofur and penicillin. The results show that in vitro the agent has signiifcant bacteriostasis effects on four major pathogens of cow mastitis, and the bactericidal and bacteriostatic concentration is lower than ceftiofur and penicillin.%本试验采用10倍稀释法进行了乳头药浴涂膜剂对奶牛乳房炎临床分离菌株(大肠杆菌、金黄色葡萄球菌、无乳链球菌及停乳链球菌)的体外抑菌效果测定。结果显示,乳头药浴涂膜剂对四种致病菌有良好的体外抑菌和杀菌作用,其抑杀菌浓度低于头孢噻呋和青霉素。

  4. Spectrophotometric determination of triclosan in personal care products

    Science.gov (United States)

    Lu, Huihui; Ma, Hongbing; Tao, Guanhong

    2009-09-01

    A spectrophotometric method for the determination of triclosan in personal care products was proposed. It was based on the reaction of sodium nitrite with p-sulfanilic acid in an acidic medium to form diazonium ion, with which triclosan further formed an azo compound in an alkaline medium. The resulting yellow colored product has a maximum absorption at 452 nm. A good linear relationship ( r = 0.9999) was obtained in the range of 0-30 mg L -1 triclosan. A detection limit of 0.079 g L -1 was achieved and the relative standard deviation was 0.24% ( n = 11) at 14 mg L -1 triclosan. The proposed method has been applied to the analyses of triclosan in several personal care products and the results were in good agreement with those obtained by high-performance liquid chromatography.

  5. Triclosan and methyl-triclosan dissipation in soils after biosolid application

    Science.gov (United States)

    Triclosan (TCS) is removed in waste water treatment plants (WWTP) primarily as biosolids (approx. 66%). Therefore, biosolids disposal as land applications represents a significant path for release to the environment. Biosolids collected over three years from a large WWTP had concentrations of TCS ...

  6. Biodegradation of triclosan and formation of methyl-triclosan in activated sludge under aerobic conditions

    DEFF Research Database (Denmark)

    Chen, Xijuan; Nielsen, Jeppe Lund; Furgal, Karolina

    2011-01-01

    of triclosan- methyl was investigated in activated sludge from a standard activated sludge WWTP equipped with enhanced biological phosphorus removal. The removal was found to occur mainly under aerobic conditions while under anoxic (nitrate reducing) and anaerobic conditions rather low removal rates were...

  7. Time-kill determination of the bactericidal activity of telavancin and vancomycin against clinical methicillin-resistant Staphylococcus aureus isolates from cancer patients.

    Science.gov (United States)

    Rolston, Kenneth Vi; Wang, Weiqun; Nesher, Lior; Smith, Jordan R; Rybak, Michael J; Prince, Randall A

    2017-04-01

    The bactericidal activity of vancomycin and telavancin was compared against 4 clinical methicillin-resistant Staphylococcus aureus isolates recently recovered from cancer patients, using minimum bactericidal concentration (MBC):MIC ratios and time-kill studies. All 4 isolates were susceptible to both agents based on individual MIC values. The 2 methodologies for assessing bactericidal activity produced variable results. Telavancin appeared to have somewhat better bactericidal activity than vancomycin based on narrower MBC:MIC ratios. However, based on the results of the time-kill studies, neither agent demonstrated reliable bactericidal activity (defined as a ≥3 log10 reduction of the starting inoculum at the end of 24hours) against these organisms. These findings might be of some therapeutic importance in certain clinical settings and/or specific patient populations (such as febrile neutropenic patients) in whom potent bactericidal activity is either desired or preferred.

  8. TRICLOSAN AND METHYL-TRICLOSAN MONITORING STUDY IN THE NORTHEAST OF SPAIN USING A MAGNETIC PARTICLE ENZYME IMMUNOASSAY AND CONFIRMATORY ANALYSIS BY GAS CHROMATOGRAPHY-MASS SPECTROMETRY

    Science.gov (United States)

    The occurrence of triclosan in the water environment around a Mediterranean region was investigated. Triclosan and methyl-triclosan content of ninety five environmental samples were screened using a magnetic particle enzyme immunoassay. Positive samples were confirmed by solid phase extraction (SPE...

  9. Developmental Triclosan Exposure Decreases Maternal and Offspring Thyroxine in Rats*

    Science.gov (United States)

    Epidemiological and laboratory data have demonstrated that disruption of maternal thyroid hormones during fetal developmental may result in irreversible neurological consequences in offspring. In a short-term exposure paradigm, triclosan decreased systemic thyroxine (T4) concentr...

  10. Triclosan: Current Status, Occurrence, Environmental Risks and Bioaccumulation Potential

    Directory of Open Access Journals (Sweden)

    Gurpreet Singh Dhillon

    2015-05-01

    Full Text Available Triclosan (TCS is a multi-purpose antimicrobial agent used as a common ingredient in everyday household personal care and consumer products. The expanded use of TCS provides a number of pathways for the compound to enter the environment and it has been detected in sewage treatment plant effluents; surface; ground and drinking water. The physico-chemical properties indicate the bioaccumulation and persistence potential of TCS in the environment. Hence, there is an increasing concern about the presence of TCS in the environment and its potential negative effects on human and animal health. Nevertheless, scarce monitoring data could be one reason for not prioritizing TCS as emerging contaminant. Conventional water and wastewater treatment processes are unable to completely remove the TCS and even form toxic intermediates. Considering the worldwide application of personal care products containing TCS and inefficient removal and its toxic effects on aquatic organisms, the compound should be considered on the priority list of emerging contaminants and its utilization in all products should be regulated.

  11. Triclosan: current status, occurrence, environmental risks and bioaccumulation potential.

    Science.gov (United States)

    Dhillon, Gurpreet Singh; Kaur, Surinder; Pulicharla, Rama; Brar, Satinder Kaur; Cledón, Maximiliano; Verma, Mausam; Surampalli, Rao Y

    2015-05-22

    Triclosan (TCS) is a multi-purpose antimicrobial agent used as a common ingredient in everyday household personal care and consumer products. The expanded use of TCS provides a number of pathways for the compound to enter the environment and it has been detected in sewage treatment plant effluents; surface; ground and drinking water. The physico-chemical properties indicate the bioaccumulation and persistence potential of TCS in the environment. Hence, there is an increasing concern about the presence of TCS in the environment and its potential negative effects on human and animal health. Nevertheless, scarce monitoring data could be one reason for not prioritizing TCS as emerging contaminant. Conventional water and wastewater treatment processes are unable to completely remove the TCS and even form toxic intermediates. Considering the worldwide application of personal care products containing TCS and inefficient removal and its toxic effects on aquatic organisms, the compound should be considered on the priority list of emerging contaminants and its utilization in all products should be regulated.

  12. Further research on the photo-SPME of triclosan

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Prado, Lucia; Llompart, Maria; Lores, Marta; Fernandez-Alvarez, Maria; Garcia-Jares, Carmen; Cela, Rafael [Universidad de Santiago de Compostela, Departamento de Quimica Analitica, Nutricion y Bromatologia. Facultad de Quimica, Instituto de Investigacion y Analisis Alimentario, Santiago de Compostela (Spain)

    2006-04-15

    In this study the photoinduced degradation of triclosan has been investigated by photo-solid-phase microextraction (photo-SPME). In photo-SPME, photodegradation is carried out on the SPME fibre containing the target compound. Triclosan was extracted from aqueous solutions by use of polydimethylsiloxane SPME fibres and these were subsequently exposed to UV irradiation (power 8 W, wavelength 254 nm) for different times (from 2 to 60 min). The photodegradation kinetics of triclosan were investigated, the photoproducts generated were tentatively identified, and the photochemical behaviour of these products was studied by use of this on-fibre approach followed by gas chromatographic-mass spectrometric analysis. Eight photoproducts were tentatively identified, including chlorinated phenols, chlorohydroxydiphenyl ethers, 2,8-dichlorodibenzo-p-dioxin, and a possible dichlorodibenzodioxin isomer or dichlorohydroxydibenzofuran. The main photodegradation mechanisms were postulated and photodegradation pathways proposed. The effect of pH on triclosan degradation and on triclosan-to-dioxin conversion was also investigated. Triclosan degradation occurred, and generation of 2,8-dichlorodibenzo-p-dioxin was confirmed, throughout the pH range studied (from 3 to 9). (orig.)

  13. THE BACTERICIDAL ACTION OF SYNTHETIC DETERGENTS.

    Science.gov (United States)

    Baker, Z; Harrison, R W; Miller, B F

    1941-11-30

    1. The bactericidal action of a number of anionic and cationic synthetic detergents on four Gram-positive and three Gram-negative bacteria has been investigated. 2. Cationic detergents, as a group, were found to exhibit marked bactericidal effects on Gram-positive microorganisms and somewhat less pronounced action on Gram-negative organisms. 3. The anionic detergents were germicidal only against the Gram-positive organisms, and they were considerably less effective than the cationic compounds. Of the anionic detergents, the most active one was an alkyl sulfate derived from a branched-chain, secondary alcohol. 4. Correlations between bactericidal action and inhibition of bacterial metabolism, and also between bactericidal action and chemical structure of the detergents are discussed.

  14. EVALUATION OF BACTERICIDAL EFFECTIVENESS OF BENZALKONIUM CHLORIDE

    OpenAIRE

    K. Imandel; M.B. Shaywaard; F. Mobaraki

    1996-01-01

    Benzalkonium chloride is a quaternary ammounium Compounds derivative under different names such as Afxhang, Hamoon, Mahan etc, which have great and expanded use in sanitation and medical affairs. Bactericidal activity of these disinfectants was fulfilled according to National Standard Method No.2842 on Staph. Aureus, Sal. Typhimouium and E. coli. This laboratory test showed that, except Mahan that has not bactericidal efficacy on E.coli at concentration 0.4 percent, other disinfectants under ...

  15. Docking and molecular dynamics studies on triclosan derivatives binding to FabI.

    Science.gov (United States)

    Yang, Xuyun; Lu, Junrui; Ying, Ming; Mu, Jiangbei; Li, Peichun; Liu, Yue

    2017-01-01

    FabI, enoyl-ACP reductase (ENR), is the rate-limiting enzyme in the last step for fatty acids biosynthesis in many bacteria. Triclosan (TCL) is a commercial bactericide, and as a FabI inhibitor, it can depress the substrate (trans-2-enoyl-ACP) binding with FabI to hinder the fatty acid synthesis. The structure-activity relationship between TCL derivatives and FabI protein has already been acknowledged, however, their combination at the molecular level has never been investigated. This paper uses the computer-aided approaches, such as molecular docking, molecular dynamics simulation, and binding free energy calculation based on the molecular mechanics/Poisson-Bolzmann surface area (MM/PBSA) method to illustrate the interaction rules of TCL derivatives with FabI and guide the development of new derivatives. The consistent data of the experiment and corresponding activity demonstrates that electron-withdrawing groups on side chain are better than electron-donating groups. 2-Hydroxyl group on A ring, promoting the formation of hydrogen bond, is vital for bactericidal effect; and the substituents at 4-position of A ring, 2'-position and 4'-position of B ring benefit antibacterial activity due to forming a hydrogen bond or stabilizing the conformation of active pocket residues of receptor. While the substituents at 3'-position and 5'-position of B ring destroy the π-π stacking interaction of A ring and NAD(+) which depresses the antibacterial activity. This study provides a new sight for designing novel TCL derivatives with superior antibacterial activity.

  16. Effects of triclosan on marine benthic and epibenthic organisms.

    Science.gov (United States)

    Perron, Monique M; Ho, Kay T; Cantwell, Mark G; Burgess, Robert M; Pelletier, Marguerite C

    2012-08-01

    Triclosan is an antimicrobial compound that has been widely used in consumer products such as toothpaste, deodorant, and shampoo. Because of its widespread use, triclosan has been detected in various environmental media, including wastewater, sewage sludge, surface waters, and sediments. Triclosan is acutely toxic to numerous aquatic organisms, but very few studies have been performed on estuarine and marine benthic organisms. For whole sediment toxicity tests, the sediment-dwelling estuarine amphipod, Ampelisca abdita, and the epibenthic mysid shrimp, Americamysis bahia, are commonly used organisms. In the present study, median lethal concentration values (LC50) were obtained for both of these organisms using water-only and whole sediment exposures. Acute 96-h water-only toxicity tests resulted in LC50 values of 73.4 and 74.3 µg/L for the amphipod and mysid, respectively. For the 7-d whole sediment toxicity test, LC50 values were 303 and 257 mg/kg (dry wt) for the amphipod and mysid, respectively. Using equilibrium partitioning theory, these whole sediment values are equivalent to interstitial water LC50 values of 230 and 190 µg/L for the amphipod and mysid, respectively, which are within a threefold difference of the observed 96-h LC50 water-only values. Triclosan was found to accumulate in polychaete tissue in a 28-d bioaccumulation study with a biota-sediment accumulation factor of 0.23 kg organic carbon/kg lipid. These data provide some of the first toxicity data for triclosan with marine benthic and epibenthic species while also indicating a need to better understand the effects of other forms of sediment carbon, triclosan ionization, and organism metabolism of triclosan on the chemical's behavior and toxicity in the aquatic environment.

  17. Triclosan Alters Thyroid Hormone Homeostasis via Up-regulation of Hepatic Catabolism

    Science.gov (United States)

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) decreases serum thyroxine (T4) in the weanling rat. Scientific uncertainties include: by what mode of action (MOA) does triclosan decrease T4, and does triclosan induce hypothyroxinemia in dams and neonates? To test the hypothes...

  18. Faster photodegradation rate and higher dioxin yield of triclosan induced by cationic surfactant CTAB.

    Science.gov (United States)

    Qiao, Xianliang; Zheng, Xiaodong; Xie, Qing; Yang, Xianhai; Xiao, Jie; Xue, Weifeng; Chen, Jingwen

    2014-06-30

    Triclosan has received extensive attention as it has been frequently detected in the aquatic environment. Photolysis was found to be a major pathway governing the fate of triclosan in the aquatic environment. However, the effects of surfactants that usually coexist with triclosan, on the photodegradation of triclosan, are largely unknown. In this study, the effects of selected surfactants on the photodegradation of triclosan were investigated experimentally. The results show that anionic sodium dodecyl benzene sulfonate, sodium dodecyl sulfate and neutral polyoxyethylene (20) sorbitan monooleate inhibit the photolysis of triclosan, whereas cationic cetyltrimethylammonium bromide (CTAB) significantly accelerates the photodegradation rate of triclosan. The interactions between the hydrophilic group of CTAB and anionic triclosan lead to the apparent decrease of pKa of triclosan from 8.4 to 6.1, which increase the fraction of anionic triclosan from 4% to 89% in neutral solution. A red shift in the UV-VIS absorption spectrum is exhibited, thus leading to the increased photodegradation rate of triclosan. The accelerations caused by CTAB were observed under xenon lamp and Hg lamp irradiances, as well as under natural sunlight. Effect of CTAB demonstrated pH dependence with significantly enhancement under pH 5∼9 and inhibition at pH=3. The presence of CTAB also increased the yield of 2,8-dichlorodibenzo-p-dioxin from the photolysis of triclosan about 7 times at pH=7.

  19. Resistance and recovery of river biofilms receiving short pulses of Triclosan and Diuron.

    Science.gov (United States)

    Proia, L; Morin, S; Peipoch, M; Romaní, A M; Sabater, S

    2011-08-01

    The effects of the herbicide Diuron (DIU) and the bactericide Triclosan (TCS) were assessed on laboratory-grown stream biofilms. Four week-old biofilms were exposed in mesocosms to 48-hours of short pulses of either DIU or TCS. The direct and indirect effects of each toxicant on the biofilms, and the subsequent recovery of the biofilms, were evaluated according to structural and functional biomarkers. These parameters were analyzed immediately before exposure, immediately after exposure, and 9 and 16days post-exposure. DIU caused an increase in diatom mortality (+79%), which persisted until the end of the experiment. TCS also affected diatom mortality (+41%), although the effect did not appear until 1week post-exposure. TCS caused an increase in bacterial mortality (+45%); however, this parameter returned to normal values 1week post-exposure. TCS compromised the cellular integrity of the green alga Spirogyra sp., whereas DIU did not. TCS also strongly inhibited phosphate uptake (-71%), which did not return to normal values until 2weeks post-exposure. DIU directly affected algae, but barely affected the heterotrophs, whereas TCS seriously impaired bacteria (direct effect) as well as autotrophs (indirect effect). However, the biofilms recovered their normal structure and function within only a few days to a few weeks. These findings demonstrate the capacity of biofilms to cope with periodic inputs of toxicants, but also the risks associated to repeated exposure or multi-contamination in aquatic ecosystems.

  20. Use of pooled samples to assess human exposure to parabens, benzophenone-3 and triclosan in Queensland, Australia.

    Science.gov (United States)

    Heffernan, A L; Baduel, C; Toms, L M L; Calafat, A M; Ye, X; Hobson, P; Broomhall, S; Mueller, J F

    2015-12-01

    Parabens, benzophenone-3 and triclosan are common ingredients used as preservatives, ultraviolet radiation filters and antimicrobial agents, respectively. Human exposure occurs through consumption of processed food and use of cosmetics and consumer products. The aim of this study was to provide a preliminary characterisation of exposure to selected personal care product chemicals in the general Australian population. De-identified urine specimens stratified by age and sex were obtained from a community-based pathology laboratory and pooled (n=24 pools of 100). Concentrations of free and total (sum of free plus conjugated) species of methyl, ethyl, propyl and butyl paraben, benzophenone-3 and triclosan were quantified using isotope dilution tandem mass spectrometry; with geometric means 232, 33.5, 60.6, 4.32, 61.5 and 87.7ng/mL, respectively. Age was inversely associated with paraben concentration, and females had concentrations approximately two times higher than males. Total paraben and benzophenone-3 concentrations are significantly higher than reported worldwide, and the average triclosan concentration was more than one order of magnitude higher than in many other populations. This study provides the first data on exposure of the general Australian population to a range of common personal care product chemical ingredients, which appears to be prevalent and warrants further investigation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Bactericidal Influence of Silver Nanocomposites on Clavibacter michiganensis ssp. sepedonicus

    Directory of Open Access Journals (Sweden)

    Perfileva А.I.

    2016-05-01

    Full Text Available The results of studying the effect of silver nanocomposites received by chemical synthesis on the bacterium Clavibacter michiganensis ssp. sepedonicus (Cms are presented. Cms is a Gram-positive bacterium, which causes one of the most dangerous potato diseases, ring rot. The effective alongside ecologically safe methods for combating Cms are lacking. As the agent, possible for application for this purpose, we investigated silver nanocomposites. For definition of nanocomposites influence on Cms we applied seedings to calculation the colony-forming units, after an incubation of bacteria with a nanocomposite in the distilled water (the grown poor environment and on a nutrient medium. Influence of silver nanocomposites on cellular respiration which was estimated on oxygen absorption speed is also investigated. Thus, the obtained results demonstrate the occurrence of bactericidal effects of the substances under study, and favor the supposition on advisability of further research into the silver nanocomposites as the agents for agricultural recovery from the bacterial pathogens.

  2. Triclosan removal in wetlands constructed with different aquatic plants.

    Science.gov (United States)

    Liu, Jianing; Wang, Jingmin; Zhao, Congcong; Hay, Anthony G; Xie, Huijun; Zhan, Jian

    2015-10-22

    Triclosan (TCS) is widely used in consumer products as an antimicrobial agent. Constructed wetlands have the potential for TCS removal, but knowledge about the relative importance of sediment, plants, and microbes is limited. TCS removal performance was investigated in well-operated constructed wetlands planted with three different types of aquatic plants: emergent Cattail (C-T), submerged Hornwort (H-T), and floating Lemnaminor (L-T). Results showed that the TCS removal efficiencies from water were all greater than 97 %. Maximal TCS adsorption to sediment in the C-T wetland (13.8 ± 0.6 ng/g) was significantly lower than in the H-T wetland (21.0 ± 0.3 ng/g) or the L-T wetland (21.4 ± 0.6 ng/g). The maximal TCS concentrations in plants were 5.7 ± 0.2 and 7.2 ± 0.5 μg/g for H-T and L-T, respectively, and it was below the minimal detection limit (MDL) in C-T. Deep 16S rRNA gene sequencing results revealed that C-T wetland had the highest community richness and diversity. Some bacteria, like beta-Proteobacteria, gamma-Proteobacteria, and Bacteroidetes were detected and might have significant correlations with TCS degradation. Overall, with regard to soils, plants, and microorganism, accumulation in sediment and plants in H-T and L-T was high, while in C-T biodegradation likely played an important role.

  3. Environmental Exposure to Triclosan and Semen Quality.

    Science.gov (United States)

    Zhu, Wenting; Zhang, Hao; Tong, Chuanliang; Xie, Chong; Fan, Guohua; Zhao, Shasha; Yu, Xiaogang; Tian, Ying; Zhang, Jun

    2016-02-17

    Triclosan (2,4,4'-trichloro-2'-hydroxy-diphenyl ether, TCS) is widely used in personal care, household, veterinary and industrial products. It was considered as a potential male reproductive toxicant in previous in vitro and in vivo studies. However, evidence from human studies is scarce. Our study aims to investigate the relationship between TCS exposure and semen quality. We measured urinary TCS concentrations in 471 men recruited from a male reproductive health clinic. TCS was detected in 96.7% of urine samples, with a median concentration of 0.97 ng (mg·creatinine)(-1) (interquartile range, 0.41-2.95 ng (mg·creatinine)(-1)). A multiple linear regression analysis showed a negative association between natural logarithm (Ln) transformed TCS concentration (Ln-TCS) and Ln transformed number of forward moving sperms (adjusted coefficient β = -0.17; 95% confidence interval (CI) (-0.32, -0.02). Furthermore, among those with the lowest tertile of TCS level, Ln-TCS was negatively associated with the number of forward moving sperms (β = -0.35; 95% CI (-0.68, -0.03)), percentage of sperms with normal morphology (β = -1.64; 95% CI (-3.05, -0.23)), as well as number of normal morphological sperms, sperm concentration and count. Our findings suggest that the adverse effect of TCS on semen quality is modest at the environment-relevant dose in humans. Further studies are needed to confirm our findings.

  4. Staphylococcus epidermidis isolated in 1965 are more susceptible to triclosan than current isolates.

    Directory of Open Access Journals (Sweden)

    Sissel Skovgaard

    Full Text Available Since its introduction to the market in the 1970s, the synthetic biocide triclosan has had widespread use in household and medical products. Although decreased triclosan susceptibility has been observed for several bacterial species, when exposed under laboratory settings, no in vivo studies have associated triclosan use with decreased triclosan susceptibility or cross-resistance to antibiotics. One major challenge of such studies is the lack of strains that with certainty have not been exposed to triclosan. Here we have overcome this challenge by comparing current isolates of the human opportunistic pathogen Staphylococcus epidermidis with isolates collected in the 1960s prior to introduction of triclosan to the market. Of 64 current S. epidermidis isolates 12.5% were found to have tolerance towards triclosan defined as MIC≥0.25 mg/l compared to none of 34 isolates obtained in the 1960s. When passaged in the laboratory in the presence of triclosan, old and current susceptible isolates could be adapted to the same triclosan MIC level as found in current tolerant isolates. DNA sequence analysis revealed that laboratory-adapted strains carried mutations in fabI encoding the enoyl-acyl carrier protein reductase isoform, FabI, that is the target of triclosan, and the expression of fabI was also increased. However, the majority of the tolerant current isolates carried no mutations in fabI or the putative promoter region. Thus, this study indicates that the widespread use of triclosan has resulted in the occurrence of S. epidermidis with tolerance towards triclosan and that the adaptation involves FabI as well as other factors. We suggest increased caution in the general application of triclosan as triclosan has not shown efficacy in reducing infections and is toxic to aquatic organisms.

  5. EVALUATION OF BACTERICIDAL EFFECTIVENESS OF BENZALKONIUM CHLORIDE

    Directory of Open Access Journals (Sweden)

    K. Imandel

    1996-06-01

    Full Text Available Benzalkonium chloride is a quaternary ammounium Compounds derivative under different names such as Afxhang, Hamoon, Mahan etc, which have great and expanded use in sanitation and medical affairs. Bactericidal activity of these disinfectants was fulfilled according to National Standard Method No.2842 on Staph. Aureus, Sal. Typhimouium and E. coli. This laboratory test showed that, except Mahan that has not bactericidal efficacy on E.coli at concentration 0.4 percent, other disinfectants under the study in concentrations of 0.4, 0.8, 1, 1.2 percent have reliable antibacterial properties, and bacterial resistance to benzalkonium chloride has not occurred yet.

  6. Environmental Exposure to Triclosan and Semen Quality

    Directory of Open Access Journals (Sweden)

    Wenting Zhu

    2016-02-01

    Full Text Available Triclosan (2,4,4′-trichloro-2′-hydroxy-diphenyl ether, TCS is widely used in personal care, household, veterinary and industrial products. It was considered as a potential male reproductive toxicant in previous in vitro and in vivo studies. However, evidence from human studies is scarce. Our study aims to investigate the relationship between TCS exposure and semen quality. We measured urinary TCS concentrations in 471 men recruited from a male reproductive health clinic. TCS was detected in 96.7% of urine samples, with a median concentration of 0.97 ng (mg·creatinine−1 (interquartile range, 0.41–2.95 ng (mg·creatinine−1. A multiple linear regression analysis showed a negative association between natural logarithm (Ln transformed TCS concentration (Ln-TCS and Ln transformed number of forward moving sperms (adjusted coefficient β = −0.17; 95% confidence interval (CI (−0.32, −0.02. Furthermore, among those with the lowest tertile of TCS level, Ln-TCS was negatively associated with the number of forward moving sperms (β = −0.35; 95% CI (−0.68, −0.03, percentage of sperms with normal morphology (β = −1.64; 95% CI (−3.05, −0.23, as well as number of normal morphological sperms, sperm concentration and count. Our findings suggest that the adverse effect of TCS on semen quality is modest at the environment-relevant dose in humans. Further studies are needed to confirm our findings.

  7. Urinary triclosan is associated with elevated body mass index in NHANES.

    Directory of Open Access Journals (Sweden)

    Joanna Lankester

    Full Text Available BACKGROUND: Triclosan-a ubiquitous chemical in toothpastes, soaps, and household cleaning supplies-has the potential to alter both gut microbiota and endocrine function and thereby affect body weight. METHODS: We investigated the relationship between triclosan and body mass index (BMI using National Health and Nutrition Examination Surveys (NHANES from 2003-2008. BMI and spot urinary triclosan levels were obtained from adults. Using two different exposure measures-either presence vs. absence or quartiles of triclosan-we assessed the association between triclosan and BMI. We also screened all NHANES serum and urine biomarkers to identify correlated factors that might confound observed associations. RESULTS: Compared with undetectable triclosan, a detectable level was associated with a 0.9-point increase in BMI (p<0.001. In analysis by quartile, compared to the lowest quartile, the 2nd, 3rd and 4th quartiles of urinary triclosan were associated with BMI increases of 1.5 (p<0.001, 1.0 (p = 0.002, and 0.3 (p = 0.33 respectively. The one strong correlate of triclosan identified in NHANES was its metabolite, 2,4-dichlorophenol (ρ = 0.4; its association with BMI, however, was weaker than that of triclosan. No other likely confounder was identified. CONCLUSIONS: Triclosan exposure is associated with increased BMI. Stronger effect at moderate than high levels suggests a complex mechanism of action.

  8. Removal of triclosan in nitrifying activated sludge: effects of ammonia amendment and bioaugmentation.

    Science.gov (United States)

    Lee, Do Gyun; Cho, Kun-Ching; Chu, Kung-Hui

    2015-04-01

    This study investigated two possible strategies, increasing ammonia oxidation activity and bioaugmenting with triclosan-degrader Sphingopyxis strain KCY1, to enhance triclosan removal in nitrifying activated sludge (NAS). Triclosan (2 mg L(-1)) was removed within 96-h in NAS bioreactors amended with 5, 25 and 75 mg L(-1) of ammonium (NH4-N). The fastest triclosan removal was observed in 25 mg NH4-NL(-1) amended-bioreactors where high ammonia oxidation occurred. Inhibition of ammonia oxidation and slower triclosan removal were observed in 75 mg NH4-NL(-1) amended-bioreactors. Triclosan removal was correlated to the molar ratio of the amount of nitrate produced to the amount of ammonium removed. Bioaugmentation with strain KCY1 did not enhance triclosan removal in the bioreactors with active ammonia oxidation. Approximately 36-42% and 59% of triclosan added were removed within 24-h by ammonia-oxidizing bacteria and unknown triclosan-degrading heterotrophs, respectively. The results suggested that increasing ammonia oxidation activity can be an effective strategy to enhance triclosan removal in NAS.

  9. Bactericidal properties of pradofloxacin against veterinary pathogens.

    Science.gov (United States)

    Silley, Peter; Stephan, Bernd; Greife, Heinrich A; Pridmore, Andrew

    2012-05-25

    Pradofloxacin is a new veterinary 8-cyano-fluoroquinolone developed for use against bacterial infections in dogs and cats involving both aerobic and anaerobic bacteria. The minimal bactericidal concentrations have been determined against clinical isolates of Staphylococcus pseudintermedius, Staphylococcus aureus, Escherichia coli, Pasteurella multocida, Streptococcus canis, Proteus spp., Fusobacterium spp., Porphyromonas gingivalis and Prevotella species. A subset of these species was selected, and the in vitro rate of kill by pradofloxacin was determined. For 27 of the 30 tested aerobic strains the pradofloxacin MBC was within two doubling dilutions of the MIC. For the remaining strains, the MIC and MBC were within three to four doubling dilutions. Pradofloxacin also demonstrated bactericidal activity against all anaerobic strains, and the MBC was equal to the MIC for four of the strains, within 1 doubling dilution for three strains, within 2 dilutions for a further 3 strains and within 3 dilutions for the remaining five strains. As pradofloxacin concentration was increased, a faster rate of killing was observed; bactericidal effects were seen in all cases at concentrations ≤ 0.25 μg/mL. The bactericidal activity against the anaerobic strains was marked, of particular relevance was the complete absence of regrowth even at 48 h at concentrations as low as 0.125 μg/mL. In conclusion, pradofloxacin exhibits clear bactericidal activity in terms of MBC and kill kinetics against aerobic and anaerobic clinical isolates from dogs and cats at concentrations that are greatly exceeded within the systemic circulation after administration of the recommended therapeutic doses to the target animals. It is expected that such a rapid rate of kill will play a significant role in clinical efficacy. These data demonstrate the complete and rapid killing of anaerobic bacteria by a veterinary 8-cyano-fluoroquinolone.

  10. Fate of Triclosan and Triclocarban in Land-Applied Biosolids

    Science.gov (United States)

    The heavily-used antimicrobials, triclosan and triclocarbon, are commonly present in biosolids generated in waste water treatment plants. A common practice for handling biosolids is to use them as soil amendments. We have embarked on a cooperative study with the Blue Plains Waste Water Treatment P...

  11. Examining triclosan-induced potentiation of the estrogen uterotrophic effect

    Science.gov (United States)

    Triclosan (TCS), a widely used antibacterial, has been shown to be an endocrine disruptor. We reported previously that TCS potentiated the estrogenic effect of ethinyl estradiol (EE) on uterine growth in rats orally administered 3 μg/kg EE and TCS (2 to 18 mg/kg) in the utero...

  12. Fate of triclosan and methyltriclosan in soil from biosolids application

    Science.gov (United States)

    Biosolids contain synthetic chemicals that have the potential to alter soil microbial communities and disrupt endocrine functions if they move offsite. In this study, the persistence of triclosan (TCS), an antibacterial compound normally found in biosolids and in soils after biosolids applications ...

  13. Determination of Triclosan and Ketoprofen in River Water and ...

    African Journals Online (AJOL)

    NICO

    The method was validated by spiking ultra-pure water and wastewater ... detected in human milk.5 Triclosan inhibits the enoyl-acyl carrier ... simple, sensitive, accurate, rapid and affordable for the simulta- .... to other solvents tested. This is in ...

  14. An immunoassay for the detection of triclosan-O-glucuronide, a primary human urinary metabolite of triclosan.

    Science.gov (United States)

    Ranganathan, Anupama; Gee, Shirley J; Hammock, Bruce D

    2015-09-01

    Triclosan-O-glucuronide (TCSG) is one of the primary urinary metabolites of the antibacterial compound triclosan or TCS that is found in many personal care products and consumer goods. We have developed a competitive, indirect heterologous ELISA for the detection of the target TCSG in urine. Such an ELISA for TCSG could be developed as a useful tool to measure this important biomarker of human exposure to TCS. Immunogens were prepared by conjugating TCSG to thyroglobulin, via heterobifunctional cross-linkers AEDP or 3-[(2-aminoethyl)dithio] propionic acid•hydrochloride and TFCS or N-[ε-trifluoroacetylcaproyloxy]succinimide ester. The coating antigen was prepared by the direct conjugation of TCSG to bovine serum albumin. Antibodies raised in rabbits 2619, 2621 (immunogen TCSG-AEDP-Thy), and 2623 (immunogen TCSG-TFCS-Thy), and the coating antigen were screened and characterized to determine their optimal concentrations. The optimized ELISA, developed with antibody 2621, gave an IC50 value of 2.85 ng/mL, with the linear range (IC20-IC80) determined to be 2.6-24.8 ng/mL. Selectivity of the assay was assessed by measuring cross-reactivity of antibody 2621 to related congeners such as the aglycone TCS, triclosan-O-sulfate, triclocarban, a polybrominated diphenyl ether derivative, and 3-phenoxybenzyl alcohol glucuronide. There was virtually no recognition by antibody 2621 to any of these cross-reactants. Graphical Abstract Urinary biomarker analysis of triclosan glucuronide.

  15. Oxidation of triclosan by ferrate: Reaction kinetics, products identification and toxicity evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Yang Bin [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Ying Guangguo, E-mail: guang-guo.ying@csiro.au [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Zhao Jianliang; Zhang Lijuan; Fang Yixiang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Nghiem, Long Duc [School of Civil Mining and Environmental Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia)

    2011-02-15

    Research highlights: {yields} Triclosan reacted rapidly with ferrate. {yields} Oxidation resulted in a decrease in algal toxicity. {yields} No inhibition of algae growth from ferrate. - Abstract: The oxidation of triclosan by commercial grade aqueous ferrate (Fe(VI)) was investigated and the reaction kinetics as a function of pH (7.0-10.0) were experimentally determined. Intermediate products of the oxidation process were characterized using both GC-MS and RRLC-MS/MS techniques. Changes in toxicity during the oxidation process of triclosan using Fe(VI) were investigated using Pseudokirchneriella subcapitata growth inhibition tests. The results show that triclosan reacted rapidly with Fe(VI), with the apparent second-order rate constant, k{sub app}, being 754.7 M{sup -1} s{sup -1} at pH 7. At a stoichiometric ratio of 10:1 (Fe(VI):triclosan), complete removal of triclosan was achieved. Species-specific rate constants, k, were determined for reaction of Fe(VI) with both the protonated and deprotonated triclosan species. The value of k determined for neutral triclosan was 6.7({+-}1.9) x 10{sup 2} M{sup -1} s{sup -1}, while that measured for anionic triclosan was 7.6({+-}0.6) x 10{sup 3} M{sup -1} s{sup -1}. The proposed mechanism for the oxidation of triclosan by the Fe(VI) involves the scission of ether bond and phenoxy radical addition reaction. Coupling reaction may also occur during Fe(VI) degradation of triclosan. Overall, the degradation processes of triclosan resulted in a significant decrease in algal toxicity. The toxicity tests showed that Fe(VI) itself dosed in the reaction did not inhibit green algae growth.

  16. Urinary Triclosan is Associated with Elevated Body Mass Index in NHANES

    OpenAIRE

    Joanna Lankester; Chirag Patel; Mark R Cullen; Catherine Ley; Julie Parsonnet

    2013-01-01

    BACKGROUND: Triclosan-a ubiquitous chemical in toothpastes, soaps, and household cleaning supplies-has the potential to alter both gut microbiota and endocrine function and thereby affect body weight. METHODS: We investigated the relationship between triclosan and body mass index (BMI) using National Health and Nutrition Examination Surveys (NHANES) from 2003-2008. BMI and spot urinary triclosan levels were obtained from adults. Using two different exposure measures-either presence vs. absenc...

  17. Bacteriophages as Bactericides in Plant Protection

    Directory of Open Access Journals (Sweden)

    Aleksa Obradović

    2009-01-01

    Full Text Available Control of plant pathogenic bacteria is a serious problem in production of many agricultural crops. High multiplication rate, adaptability and life inside plant tissue make bacteria unsuitable and inaccessible for most of control measures. Consequently, the list of bactericides available for plant protection is very short. Lately, biological control measures have been intensively studied as a potential solution of the problem. Investigation of bacteriophages,viruses that attack bacteria, is a fast-expanding area of research in plant protection. Several experiments have shown that they can be used as a very efficient tool for control of plant pathogenic bacteria. The fact that they are widespread natural bacterial enemies, simple for cultivation and management, host-specific, suitable for integration with other control practices, human and environment friendly, provide a great advantage for the application of phages over other bactericides.

  18. Staphylococcus epidermidis isolated in 1965 are more susceptible to triclosan than current isolates

    DEFF Research Database (Denmark)

    Skovgaard, Sissel; Nielsen, Lene Nørby; Larsen, Marianne Halberg;

    2013-01-01

    pathogen Staphylococcus epidermidis with isolates collected in the 1960s prior to introduction of triclosan to the market. Of 64 current S. epidermidis isolates 12.5% were found to have tolerance towards triclosan defined as MIC≥0.25 mg/l compared to none of 34 isolates obtained in the 1960s. When passaged...... in the laboratory in the presence of triclosan, old and current susceptible isolates could be adapted to the same triclosan MIC level as found in current tolerant isolates. DNA sequence analysis revealed that laboratory-adapted strains carried mutations in fabI encoding the enoyl-acyl carrier protein reductase...

  19. Urinary Concentrations of Triclosan in the U.S. Population: 2003-2004

    National Research Council Canada - National Science Library

    Antonia M. Calafat; Xiaoyun Ye; Lee-Yang Wong; John A. Reidy; Larry L. Needham

    Background: Triclosan is a synthetic chemical with broad antimicrobial activity that has been used extensively in consumer products, including personal care products, textiles, and plastic kitchenware. Objectives...

  20. An Efficient and Economical Assay to Screen for Triclosan Binding to FabI.

    Science.gov (United States)

    Demissie, Robel D; Kabre, Pauline; Tuntland, Micheal L; Fung, Leslie W-M

    2016-04-01

    Triclosan is an effective inhibitor for enoyl acyl carrier protein reductase (ENR) in fatty acid biosynthesis. Triclosan-resistant mutants of ENR have emerged. Thus, it is important to detect these triclosan-resistant mutations in ENR. Generally, enzyme activity assays on the mutants are used to determine the effect of triclosan on ENR activity. Since the substrates are linked to acyl carrier protein (ACP), the assays are challenging due to the need to prepare the ACP and link it to the substrates. Non-ACP-linked (coenzyme A [CoA]-linked) substrates can be used in some ENR, but not in all. Consequently, screening for triclosan-resistant mutants is also challenging. We have developed a simple thermal shift assay, which does not use ACP-linked substrates, to determine the binding ability of triclosan to the ENR active site, and thus it can be used for screening for triclosan-resistant mutants. Staphylococcus aureus FabI enzyme and its mutants were used to demonstrate the binding ability of triclosan with NADP(+) to FabI. The direct correlation between the binding ability and enzyme activity was demonstrated with Francisella tularensis FabI. This method may also be applied to select effective triclosan analogues that inhibit ENR activity.

  1. Comparative study of bactericidal activities, postantibiotic effects, and effects of bacterial virulence of penicillin G and six macrolides against Streptococcus pneumoniae.

    OpenAIRE

    Fuursted, K.; Knudsen, J D; Petersen, M B; Poulsen, R L; Rehm, D

    1997-01-01

    In this report, we present MIC, bactericidal activity, postantibiotic effect (PAE), and in vivo infectivity data for postantibiotic-phase pneumococci. We compared and evaluated penicillin G and six macrolides, erythromycin, azithromycin, clarithromycin, dirithromycin, roxithromycin, and spiramycin, against 10 strains of pneumococci with various levels of susceptibility to penicillin. All of the agents, except azithromycin, exhibited a bactericidal effect (a > or = 3 log10 decrease in the numb...

  2. Effects of chronic triclosan exposure upon the antimicrobial susceptibility of 40 ex-situ environmental and human isolates.

    Science.gov (United States)

    Ledder, R G; Gilbert, P; Willis, C; McBain, A J

    2006-05-01

    Triclosan (TCS) exposure of Escherichia coli selects for tolerant clones, mutated in their enoyl-acyl carrier protein reductase (FabI). It has been inferred that this phenomenon is widespread amongst bacterial genera and might be associated with resistance to third party agents. Ex-situ, low passage isolates of enteric, human axilla, human oral origin and bacteria isolated from a domestic drain, together with selected type cultures were exposed to escalating concentrations of TCS over 10 passages using a gradient plate technique. One fresh faecal isolate of E. coli was included as a positive control. TCS susceptibility was determined for all strains before and after exposure, whilst enteric isolates were additionally assessed for susceptibility towards chlorhexidine, tetracycline, chloramphenicol, nalidixic acid and ciprofloxacin, and the oral isolates towards chlorhexidine, tetracycline and metronidazole. Triclosan exposure of E. coli markedly decreased TCS susceptibility. TCS susceptibility also decreased for Klebsiella oxytoca, Aranicola proteolyticus and Stenotrophomonas maltophilia. Susceptibility of the remaining 35 strains to TCS and the other test agents remained unchanged. These data suggest that selection for high level resistance by TCS exposure is not widespread and appears to be confined to certain enteric bacteria, especially E. coli. Change in TCS susceptibility did not affect susceptibility towards chemically unrelated antimicrobials. Acquired high-level TCS resistance is not a widespread phenomenon.

  3. Pseudomonas aeruginosa bacteriophage PA1Ø requires type IV pili for infection and shows broad bactericidal and biofilm removal activities.

    Science.gov (United States)

    Kim, Shukho; Rahman, Marzia; Seol, Sung Yong; Yoon, Sang Sun; Kim, Jungmin

    2012-09-01

    We isolated a new lytic Pseudomonas aeruginosa phage that requires type IV pili for infection. PA1Ø has a broad bactericidal spectrum, covering Gram-positive and Gram-negative bacteria, and can eradicate biofilm cells. PA1Ø may be developed as a therapeutic agent for biofilm-related mixed infections with P. aeruginosa and Staphylococcus aureus.

  4. Triclosan and triclosan-loaded liposomal nanoparticles in the treatment of acute experimental toxoplasmosis.

    Science.gov (United States)

    El-Zawawy, Lobna A; El-Said, Doaa; Mossallam, Shereen F; Ramadan, Heba S; Younis, Salwa S

    2015-02-01

    Efficacy of triclosan (TS) and TS-loaded liposomes against the virulent strain of Toxoplasma gondii (T. gondii) was evaluated. Swiss albino mice were intraperitoneally infected with 10(4) tachyzoites of RH HXGPRT(-) strain of T. gondii, then were orally treated with 150 mg/kg TS or 100 mg/kg TS liposomes twice daily for 4 days. Mice mortality, peritoneal and liver parasite burdens, viability, infectivity and ultrastructural changes of peritoneal tachyzoites of infected treated mice were studied, in comparison with those of infected non-treated controls. Drug safety was biochemically assessed by measuring liver enzymes and thyroxin. Both TS and TS liposomes induced significant reduction in mice mortality, parasite burden, viability and infectivity of tachyzoites harvested from infected treated mice. Scanning electron microscopy of treated tachyzoites showed distorted shapes, reduced sizes, irregularities, surface protrusions, erosions and peeling besides apical region distortion. Transmission electron microscopy showed that treated tachyzoites were intracellularly distorted, had cytoplasmic vacuolation, discontinuous plasma membranes, nuclear abnormalities and disrupted internal structures. Besides, in TS liposomes-treated subgroup, most tachyzoites were seen intracellularly with complete disintegration of the parasite plasma and nuclear membranes, with complete destruction of the internal structures. Biochemical safety of TS and TS liposomes was proven. Accordingly, TS can be considered as a promising alternative to the standard therapy for treating acute murine toxoplasmosis. Liposomal formulation of TS enhanced its efficacy and allowed its use in a lower dose.

  5. Substance flow analysis and assessment of environmental exposure potential for triclosan in mainland China.

    Science.gov (United States)

    Huang, Chu-Long; Ma, Hwong-Wen; Yu, Chang-Ping

    2014-11-15

    Triclosan (TCS) is a widely-used antimicrobial agent in many consumer products around the world, and China is a major producer and consumer of TCS. In this study substance flow analysis (SFA) was used to construct a static model of anthropogenic TCS metabolism in China in 2008. The systematic SFA results were used to determine possible exposure pathways and trends in environmental exposure potential through different pathways. TCS discharged in wastewater mainly flowed into surface water sediment, ocean, and soil, where it accumulates in aquatic and agricultural products that may pose a higher risk to human health than brief exposure during consumption. Only 22% of TCS discharged was removed in the built environment with the remainder discharged into the natural environment, indicating that anthropogenic TCS metabolism in China is unsustainable. Per capita TCS consumption increased 209% from 2003 to 2012, resulting in increased discharge and accumulation in the environment. If current trends continue, it will increase to 713 mg capita(-1) yr(-1) in 2015 and 957 mg capita(-1) yr(-1) in 2020. Accordingly, annual environmental exposure potential will increase from 388 mg capita(-1) in 2008 to 557 mg capita(-1) in 2015 and 747 mg capita(-1) in 2020, indicating an increasing trend of exposure to environmental TCS. Results of Pearson correlation analysis suggested that feasible countermeasures to reduce environmental exposure potential for triclosan would include encouraging the development of small cities, raising awareness of health risks, nurturing environmentally-friendly consumer values, and improving the environmental performance of TCS-containing products.

  6. Antimicrobial activity of toothpastes containing natural extracts, chlorhexidine or triclosan.

    Science.gov (United States)

    De Rossi, Andiara; Ferreira, Danielly Cunha Araújo; da Silva, Raquel Assed Bezerra; de Queiroz, Alexandra Mussolino; da Silva, Léa Assed Bezerra; Nelson-Filho, Paulo

    2014-01-01

    The objective of this in vitro study was to evaluate the antimicrobial effect of toothpastes containing natural extracts, chlorhexidine or triclosan. The effectiveness of toothpastes containing natural extracts (Parodontax®), 0.12% chlorhexidine (Cariax®), 0.3% triclosan (Sanogil®) or fluoride (Sorriso®, control) was evaluated against yeasts, Gram-positive and Gram-negative bacteria using the disk diffusion method. Water was used as a control. Disks impregnated with the toothpastes were placed in Petri dishes containing culture media inoculated with 23 indicative microorganisms by the pour plate method. After incubation, the inhibition growth halos were measured and statistical analyses (α=0.05) were performed. The results indicated that all formulations, except for conventional toothpaste (Sorriso®), showed antimicrobial activity against Gram-positive bacteria and yeasts. The toothpaste containing natural extracts (Parodontax®) was the only product able to inhibit the growth of Pseudomonas aeruginosa. The toothpastes containing chlorhexidine, triclosan or natural extracts presented antimicrobial activity against Gram-positive bacteria and yeasts.

  7. Bactericidal Performance of Flame-Sprayed Nanostructured Titania-Copper Composite Coatings

    Science.gov (United States)

    George, N.; Mahon, M.; McDonald, A.

    2010-09-01

    A large concern surrounding stainless steel surfaces is the ability of bacteria to grow and attach to them quite easily. One possible solution to destroy these pathogens is to coat surfaces with a biocidal agent. The photocatalytic effect of titanium dioxide (TiO2) is known to have a bactericidal effect. Coatings of TiO2 were prepared on 1010 low carbon steel substrates using an oxy-acetylene flame spray torch. TiO2 coatings containing 5 wt.% copper (Cu) were fabricated to increase the bactericidal effect of the coating. After deposition, the coatings were polished to an average roughness of 1 μm. Solutions of Pseudomonas aeruginosa (PAK) bacteria were placed onto the coating surface for periods of up to 3 h, and the amount of surviving bacteria were counted. Some samples were irradiated with white light and other samples were held in a dark chamber. In coatings of copper-free flame-sprayed TiO2, the high flame temperatures facilitated the conversion of the anatase phase to the rutile phase, which limited the photocatalytic destruction of the bacterial cells. However, TiO2-copper composite coatings showed a large bactericidal effect, killing approximately 75% of PAK bacterial cells after 3 h. Under the same conditions, the TiO2-copper composite coatings had the same bactericidal capabilities as pure copper surfaces, with the composite coatings showing improved bactericidal performance when exposed to light. It was proposed that increased concentrations of reactive oxide species produced due to TiO2 photocatalysis improved the performance of the irradiated TiO2-copper composite coatings.

  8. Disparity between timed-kill and checkerboard methods for determination of in vitro bactericidal interactions of vancomycin plus rifampin versus methicillin-susceptible and -resistant Staphylococcus aureus.

    Science.gov (United States)

    Bayer, A S; Morrison, J O

    1984-08-01

    The role of rifampin as an adjunctive agent to vancomycin in the therapy of serious systemic staphylococcal infections remains controversial. Several in vitro studies utilizing differing methodologies to define the bactericidal interactions of vancomycin plus rifampin versus Staphylococcus aureus have yielded markedly disparate results. The in vitro bactericidal synergistic activities of vancomycin plus rifampin were examined versus 48 clinical isolates of S. aureus, both methicillin susceptible and resistant. Each strain was tested simultaneously in timed-kill curve and checkerboard systems. By timed-kill curve, vancomycin plus rifampin usually had either an indifferent (67%) or synergistic (19 to 29%) effect, with a frequency dependent on sampling times; bactericidal antagonism was infrequently noted after 48 h of incubation (4%). Indifference was seen as a prevention of rifampin resistance by vancomycin. Synergy was more commonly noted at 48 than at 24 h of incubation. The bactericidal interaction results were similar for both methicillin-susceptible and -resistant strains. In contrast to the killing curve data, the checkerboard technique uniformly demonstrated bactericidal antagonism of vancomycin plus rifampin against all 48 staphylococci. We conclude that the nature of the in vitro bactericidal interactions of vancomycin plus rifampin against S. aureus is difficult to establish in vitro. This fact relates to the markedly disparate findings, which depended on both the synergy technique utilized and the test system conditions employed. In vivo studies are required to delineate the bactericidal interaction potentials of vancomycin plus rifampin versus S. aureus.

  9. TRICLOSAN ALTERS THYROID HORMONES HOMEOSTASIS VIA UP-REGULATION OF HEPATIC CATABOLISM.

    Science.gov (United States)

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is a chlorinated phenolic antibacterial compound used in household and hygiene products. The structural similarity of triclosan to thyroid hormones, in vitro studies demonstrating activation of the human pregnane X receptor (PXR)...

  10. Occurrence of triclosan in plasma of wild Atlantic bottlenose dolphins (Tursiops truncatus) and in their environment

    Energy Technology Data Exchange (ETDEWEB)

    Fair, Patricia A., E-mail: pat.fair@noaa.go [National Oceanic and Atmospheric Administration, National Ocean Services, Center for Coastal Environmental Health and Biomolecular Research, 219 Fort Johnson Road, Charleston, SC 29412-9110 (United States); Lee, H.-B. [Aquatic Ecosystem Protection Research Division, Environment Canada, 867 Lakeshore Road, Burlington, ON L7R 4A6 (Canada); Adams, Jeff [National Oceanic and Atmospheric Administration, National Ocean Services, Center for Coastal Environmental Health and Biomolecular Research, 219 Fort Johnson Road, Charleston, SC 29412-9110 (United States); Darling, Colin; Pacepavicius, Grazina; Alaee, Mehran [Aquatic Ecosystem Protection Research Division, Environment Canada, 867 Lakeshore Road, Burlington, ON L7R 4A6 (Canada); Bossart, Gregory D. [Center for Coastal Research, Marine Mammal Research and Conservation Program, Harbor Branch Oceanographic Institute at Florida Atlantic University, 5600 U.S. 1 North, Ft. Pierce, FL 34946 (United States); Henry, Natasha [National Oceanic and Atmospheric Administration, National Ocean Services, Center for Coastal Environmental Health and Biomolecular Research, 219 Fort Johnson Road, Charleston, SC 29412-9110 (United States); Muir, Derek [Aquatic Ecosystem Protection Research Division, Environment Canada, 867 Lakeshore Road, Burlington, ON L7R 4A6 (Canada)

    2009-08-15

    The presence of triclosan, a widely-used antibacterial chemical, is currently unknown in higher trophic-level species such as marine mammals. Blood plasma collected from wild bottlenose dolphins (Tursiops truncatus) in Charleston, SC (CHS) (n = 13) and Indian River Lagoon, FL (IRL) (n = 13) in 2005 was analyzed for triclosan. Plasma concentrations in CHS dolphins ranged from 0.12 to 0.27 ng/g wet weight (mean 0.18 ng/g), with 31% of the sampled individuals having detectable triclosan. The mean IRL dolphin plasma concentrations were 0.072 ng/g wet weight (range 0.025-0.11 ng/g); 23% of the samples having detectable triclosan. In the CHS area, triclosan effluent values from two WWTP were both 190 ng/L and primary influents were 2800 ng/L and 3400 ng/L. Triclosan values in CHS estuarine surface water samples averaged 7.5 ng/L (n = 18) ranging from 4.9 to 14 ng/L. This is the first study to report bioaccumulation of anthropogenic triclosan in a marine mammal highlighting the need for further monitoring and assessment. - Triclosan in bottlenose dolphin plasma and their environment.

  11. Solid phase microextraction speciation analysis of triclosan in aqueous mediacontaining sorbing nanoparticles

    NARCIS (Netherlands)

    Zielinska, K.

    2014-01-01

    Solid phase microextraction (SPME) is applied in the speciation analysis of the hydrophobic compound triclosan in an aqueous medium containing sorbing SiO2 nanoparticles (NPs). It is found that these NPs, as well as their complexes with triclosan, partition between the bulk medium and the solid

  12. Solid phase microextraction speciation analysis of triclosan in aqueous mediacontaining sorbing nanoparticles

    NARCIS (Netherlands)

    Zielinska, K.

    2014-01-01

    Solid phase microextraction (SPME) is applied in the speciation analysis of the hydrophobic compound triclosan in an aqueous medium containing sorbing SiO2 nanoparticles (NPs). It is found that these NPs, as well as their complexes with triclosan, partition between the bulk medium and the solid phas

  13. Use of a Novel Sediment Exposure to Determine the Effects of Triclosan on Estuarine Benthic Communities

    Science.gov (United States)

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy) phenol) is a relatively new, commonly used antimicrobial compound found in many personal care products. Triclosan is toxic to marine organisms at the ug/l level, can photo-degrade to a dioxin, accumulate in humans, and has been found t...

  14. Urinary levels of bisphenol A, triclosan and 4-nonylphenol in a general Belgian population.

    Science.gov (United States)

    Pirard, Catherine; Sagot, Clémence; Deville, Marine; Dubois, Nathalie; Charlier, Corinne

    2012-11-01

    Bisphenol A, triclosan and 4-nonylphenol are among the endocrine disruptors which are widely used in daily products. In this study, we reported total urinary levels of bisphenol A, triclosan and 4-nonylphenol, in order to evaluate the baseline contamination of a general population in Belgium. Bisphenol A and triclosan were detected in respectively 97.7% and 74.6% of the samples examined demonstrating that the general Belgian population is extensively exposed to both chemicals. On the other hand, 4-nonylphenol was not detected in any urine samples analyzed, suggesting either low exposure, inadequate biomarker, or that urine is an inappropriate biological matrix for assessing exposure to nonylphenol commercial mixtures. Geometric mean concentration was determined for bisphenol A at 2.55 μg/l and for triclosan at 2.70 μg/l. No significant difference was observed between levels and gender for both bisphenol A and triclosan. When classified by age, the 20-39 year group showed the highest triclosan levels, while all age groups seemed to be similarly exposed to bisphenol A. Both bisphenol A and triclosan urinary levels were not correlated with creatinine excretion in our healthy population, questioning the relevance of the creatinine adjustment in reporting these chemical levels. Bisphenol A levels in urine of people living in the same home and collected on the same time were fairly correlated, confirming the assumption that dietary intake would be the primary route of exposure. Triclosan urinary levels were not correlated with bisphenol A levels.

  15. Probabilistic application of a fugacity model to predict triclosan fate during wastewater treatment.

    Science.gov (United States)

    Bock, Michael; Lyndall, Jennifer; Barber, Timothy; Fuchsman, Phyllis; Perruchon, Elyse; Capdevielle, Marie

    2010-07-01

    The fate and partitioning of the antimicrobial compound, triclosan, in wastewater treatment plants (WWTPs) is evaluated using a probabilistic fugacity model to predict the range of triclosan concentrations in effluent and secondary biosolids. The WWTP model predicts 84% to 92% triclosan removal, which is within the range of measured removal efficiencies (typically 70% to 98%). Triclosan is predominantly removed by sorption and subsequent settling of organic particulates during primary treatment and by aerobic biodegradation during secondary treatment. Median modeled removal efficiency due to sorption is 40% for all treatment phases and 31% in the primary treatment phase. Median modeled removal efficiency due to biodegradation is 48% for all treatment phases and 44% in the secondary treatment phase. Important factors contributing to variation in predicted triclosan concentrations in effluent and biosolids include influent concentrations, solids concentrations in settling tanks, and factors related to solids retention time. Measured triclosan concentrations in biosolids and non-United States (US) effluent are consistent with model predictions. However, median concentrations in US effluent are over-predicted with this model, suggesting that differences in some aspect of treatment practices not incorporated in the model (e.g., disinfection methods) may affect triclosan removal from effluent. Model applications include predicting changes in environmental loadings associated with new triclosan applications and supporting risk analyses for biosolids-amended land and effluent receiving waters.

  16. Erratum: Probabilistic application of a fugacity model to predict triclosan fate during wastewater treatment.

    Science.gov (United States)

    Bock, Michael; Lyndall, Jennifer; Barber, Timothy; Fuchsman, Phyllis; Perruchon, Elyse; Capdevielle, Marie

    2010-10-01

    The fate and partitioning of the antimicrobial compound, triclosan, in wastewater treatment plants (WWTPs) is evaluated using a probabilistic fugacity model to predict the range of triclosan concentrations in effluent and secondary biosolids. The WWTP model predicts 84% to 92% triclosan removal, which is within the range of measured removal efficiencies (typically 70% to 98%). Triclosan is predominantly removed by sorption and subsequent settling of organic particulates during primary treatment and by aerobic biodegradation during secondary treatment. Median modeled removal efficiency due to sorption is 40% for all treatment phases and 31% in the primary treatment phase. Median modeled removal efficiency due to biodegradation is 48% for all treatment phases and 44% in the secondary treatment phase. Important factors contributing to variation in predicted triclosan concentrations in effluent and biosolids include influent concentrations, solids concentrations in settling tanks, and factors related to solids retention time. Measured triclosan concentrations in biosolids and non-United States (US) effluent are consistent with model predictions. However, median concentrations in US effluent are over-predicted with this model, suggesting that differences in some aspect of treatment practices not incorporated in the model (e.g., disinfection methods) may affect triclosan removal from effluent. Model applications include predicting changes in environmental loadings associated with new triclosan applications and supporting risk analyses for biosolids-amended land and effluent receiving waters.

  17. Preparation and bactericide activity of gallic acid stabilized gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Alvarez, S. A. [UASLP, Doctorado Institucional en Ingenieria y Ciencia de Materiales (Mexico); Martinez-Castanon, G. A., E-mail: mtzcastanon@fciencias.uaslp.m [UASLP, Maestria en Ciencias Odontologicas, Facultad de Estomatologia (Mexico); Nino-Martinez, N. [UASLP, Facultad de Ciencias (Mexico); Reyes-Macias, J. F.; Patino-Marin, N.; Loyola-Rodriguez, J. P. [UASLP, Maestria en Ciencias Odontologicas, Facultad de Estomatologia (Mexico); Ruiz, Facundo [UASLP, Facultad de Ciencias (Mexico)

    2010-10-15

    In this work, gold nanoparticles with three different sizes (13.7, 39.4, and 76.7 nm) were prepared using a simple aqueous method with gallic acid as the reducing and stabilizing agent, the different sizes were obtained varying some experimental parameters as the pH of the reaction and the amount of the gallic acid. The prepared nanoparticles were characterized using X-ray diffraction, transmission electron microscopy, dynamic light scattering, and UV-Vis spectroscopy. Samples were identified as elemental gold and present spherical morphology, a narrow size distribution and good stabilization according to TEM and DLS results. The antibacterial activity of this gallic acid stabilized gold nanoparticles against S. mutans (the etiologic agent of dental caries) was assessed using a microdilution method obtaining a minimum inhibitory concentration of 12.31, 12.31, and 49.25 {mu}g/mL for 13.7, 39.4, and 76.7 nm gold nanoparticles, respectively. The antibacterial assay showed that gold nanoparticles prepared in this work present a bactericide activity by a synergistic action with gallic acid. The MIC found for this nanoparticles are much lower than those reported for mixtures of gold nanoparticles and antibiotics.

  18. Preparation and bactericide activity of gallic acid stabilized gold nanoparticles

    Science.gov (United States)

    Moreno-Álvarez, S. A.; Martínez-Castañón, G. A.; Niño-Martínez, N.; Reyes-Macías, J. F.; Patiño-Marín, N.; Loyola-Rodríguez, J. P.; Ruiz, Facundo

    2010-10-01

    In this work, gold nanoparticles with three different sizes (13.7, 39.4, and 76.7 nm) were prepared using a simple aqueous method with gallic acid as the reducing and stabilizing agent, the different sizes were obtained varying some experimental parameters as the pH of the reaction and the amount of the gallic acid. The prepared nanoparticles were characterized using X-ray diffraction, transmission electron microscopy, dynamic light scattering, and UV-Vis spectroscopy. Samples were identified as elemental gold and present spherical morphology, a narrow size distribution and good stabilization according to TEM and DLS results. The antibacterial activity of this gallic acid stabilized gold nanoparticles against S. mutans (the etiologic agent of dental caries) was assessed using a microdilution method obtaining a minimum inhibitory concentration of 12.31, 12.31, and 49.25 μg/mL for 13.7, 39.4, and 76.7 nm gold nanoparticles, respectively. The antibacterial assay showed that gold nanoparticles prepared in this work present a bactericide activity by a synergistic action with gallic acid. The MIC found for this nanoparticles are much lower than those reported for mixtures of gold nanoparticles and antibiotics.

  19. Identification of triclosan-degrading bacteria using stable isotope probing, fluorescence in situ hybridization and microautoradiography

    DEFF Research Database (Denmark)

    Lolas, Ihab Bishara Lolas; Chen, Xijuan; Bester, Kai

    2012-01-01

    Triclosan is considered a ubiquitous pollutant and can be detected in a wide range of environmental samples. Triclosan removal by wastewater treatment plants has been largely attributed to biodegradation processes; however, very little is known about the micro-organisms involved. In this study, DNA......-based stable isotope probing (DNA-SIP) combined with microautoradiography-fluorescence in situ hybridization (MAR-FISH) was applied to identify active triclosan degraders in an enrichment culture inoculated with activated sludge. Clone library sequences of 16S rRNA genes derived from the heavy DNA fractions...... of enrichment culture incubated with 13C-labelled triclosan showed a predominant enrichment of a single bacterial clade most closely related to the betaproteobacterial genus Methylobacillus. To verify that members of the genus Methylobacillus were actively utilizing triclosan, a specific probe targeting...

  20. Photoelectrocatalytic degradation of triclosan on TiO2 nanotube arrays and toxicity change.

    Science.gov (United States)

    Liu, Haijin; Cao, Xianglin; Liu, Guoguang; Wang, Yingling; Zhang, Nan; Li, Tong; Tough, Robert

    2013-09-01

    Triclosan, one of the most widely used disinfectants, has been found to be toxic to animals and human beings. In this paper, triclosan was degraded on TiO2 nanotube arrays, using a photoelectrocatalytic (PEC) process under UV illumination, with Na2SO4 as the supporting electrolyte. The effect of bias potential was investigated and the results showed that 0V was the most appropriate potential for the degradation of triclosan. In 30min, 78.7% of triclosan had degraded during the PEC process. Intermediate analysis showed that 2,7-dichlorodibenzodioxin (DCDD) had formed during the degradation. The toxicity change during the PEC process was investigated using a luminescent bacteria test, with the results demonstrating that the toxicity of the reaction liquid decreased at the beginning and subsequently increased to a stable level. The indications were that some intermediates such as 2,7-dichlorodibenzodioxin was more toxic and stable than triclosan in the solution.

  1. Triclosan exacerbates the presence of {sup 14}C-bisphenol A in tissues of female and male mice

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, Tyler; Tang, Brandon; Catanzaro, Denys de, E-mail: decatanz@mcmaster.ca

    2014-07-15

    Current human generations are commonly exposed to both triclosan (TCS), an antimicrobial agent, and bisphenol A (BPA), the monomer of polycarbonate plastics and epoxies. Both are readily absorbed into circulation and found distributed among diverse tissues. Potential interactions between TCS and BPA are largely unstudied. We investigated whether TCS exposure affects the distribution of ingested {sup 14}C-BPA in select tissues. CF-1 mice were each subcutaneously injected with TCS then orally administered 50 μg/kg {sup 14}C-BPA. Females received 0, 0.2, 0.6, 1, 2, or 18 mg TCS (equivalent respectively to 0, 6.3, 16.9, 30.1, 60.5, and 558.9 mg/kg). Males received 0, 0.2, 2, or 18 mg TCS (equivalent respectively to 0, 5.3, 53.4, and 415.0 mg/kg). Levels of radioactivity were measured through liquid scintillation counting in blood serum and brain, reproductive, and other tissues. Significantly elevated levels of radioactivity were observed following combined TCS and {sup 14}C-BPA administration, with minimally effective TCS doses being tissue-dependent (Females: lungs, 0.6 mg; uterus, 1 mg; heart, muscle, ovaries, and serum, 18 mg. Males: serum, 0.2 mg; epididymides, 2 mg). Subsequently, we found that 2 or 6 mg TCS increased radioactivity in the ovaries and serum of females orally given only 5 μg/kg {sup 14}C-BPA. These data indicate that TCS can interact with BPA in vivo, magnifying its presence in certain tissues and serum. The data are consistent with evidence that TCS utilizes enzymes that are critical for metabolism and excretion of BPA. Further research should investigate the mechanisms through which these two chemicals interact at environmentally-relevant doses. - Highlights: • We examined whether triclosan exposure affects the distribution of oral {sup 14}C-BPA. • Radioactivity was elevated in select tissues of mice injected sc with triclosan. • In females, this effect was most pronounced in the uterus, ovaries, and lungs. • In males, this effect was

  2. The associations of triclosan and paraben exposure with allergen sensitization and wheeze in children.

    Science.gov (United States)

    Spanier, Adam J; Fausnight, Tracy; Camacho, Tareq F; Braun, Joseph M

    2014-01-01

    Triclosan and parabens are chemicals used in personal care and medical products as microbicides and preservatives. Triclosan and paraben exposure may be associated with allergy (atopy), but these associations have not been evaluated with respect to other atopic states such as eczema (atopic dermatitis). This study examines the associations of urinary triclosan and paraben concentrations with allergic sensitization and asthma in children according to eczema history. We performed a cross-sectional analysis of U.S. children aged 6-18 years who participated in the National Health and Nutrition Examination Survey (2005-2006). Triclosan and paraben concentrations were measured in urine. We assessed associations of triclosan and parabens with allergic sensitization and asthma using multivariable logistic regression in 837 children with complete data and stratified our results by eczema status. After covariate adjustment, triclosan and methyl and propyl paraben concentrations were positively associated with the odds of aeroallergen sensitization. Eczema did not significantly modify the association between triclosan or paraben levels and aeroallergen sensitization, asthma, or wheeze. The odds of parent-reported atopic asthma increased 34% (95% CI, 0, 81) across triclosan concentration quartiles. Increasing triclosan concentrations (quartiles) were associated with 2.3 times the odds of food sensitization (95% CI, 1.14, 4.44) among children with eczema, but not among children without eczema (OR, 1.25; 95% CI 0.93, 1.68; effect measure modification, p = 0.04). Triclosan and paraben exposures may increase the risk of atopic asthma and aeroallergen sensitization. Prospective studies are necessary to confirm these findings and determine if these chemicals pose a risk to children's health.

  3. The associations of triclosan and paraben exposure with allergen sensitization and wheeze in children

    Science.gov (United States)

    Fausnight, Tracy; Camacho, Tareq F.; Braun, Joseph M.

    2014-01-01

    Triclosan and parabens are chemicals used in personal care and medical products as microbicides and preservatives. Triclosan and paraben exposure may be associated with allergy (atopy), but these associations have not been evaluated with respect to other atopic states such as eczema (atopic dermatitis). This study examines the associations of urinary triclosan and paraben concentrations with allergic sensitization and asthma in children according to eczema history. We performed a cross-sectional analysis of U.S. children aged 6–18 years who participated in the National Health and Nutrition Examination Survey (2005–2006). Triclosan and paraben concentrations were measured in urine. We assessed associations of triclosan and parabens with allergic sensitization and asthma using multivariable logistic regression in 837 children with complete data and stratified our results by eczema status. After covariate adjustment, triclosan and methyl and propyl paraben concentrations were positively associated with the odds of aeroallergen sensitization. Eczema did not significantly modify the association between triclosan or paraben levels and aeroallergen sensitization, asthma, or wheeze. The odds of parent-reported atopic asthma increased 34% (95% CI, 0, 81) across triclosan concentration quartiles. Increasing triclosan concentrations (quartiles) were associated with 2.3 times the odds of food sensitization (95% CI, 1.14, 4.44) among children with eczema, but not among children without eczema (OR, 1.25; 95% CI 0.93, 1.68; effect measure modification, p = 0.04). Triclosan and paraben exposures may increase the risk of atopic asthma and aeroallergen sensitization. Prospective studies are necessary to confirm these findings and determine if these chemicals pose a risk to children's health. PMID:25584915

  4. Occurrence of triclosan in the tropical rivers receiving the effluents from the hospital wastewater treatment plant.

    Science.gov (United States)

    Yang, Gordon C C; Tsai, Hsin-Jen; Chang, Fu-Kuei

    2015-03-01

    The objective of this study was to determine the occurrence of triclosan in the tropical rivers where received the effluents from a hospital wastewater treatment plant (HWWTP) in southern Taiwan. Three and ten sampling sites were selected at the Jiaosu River (S0-S2) and Dian-Bao River (S3-S12), respectively. The samples of the HWWTP influent, effluent and receiving river water and sediment were collected and analyzed using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/ MS). Results showed that the triclosan level in surface water of the Jiaosu River and Dian-Bao River ranged from 3 to 68 ng/L and ranged from triclosan to the neighboring river. The mean value of triclosan concentration in the downstream surface water of the Jiaosu River (S1 20.2 ng/L) was approximately three times higher than that of the background level (S0 6.0 ng/L) (p = 0.011). The concentrations of triclosan in two surface water samples were over the predicted no effect concentration (PNEC) of 50 ng/L for algae. In addition, significant seasonal differences of triclosan in surface water of Jiaosu River (p = 0.020) and the HWWTP effluents (p = 0.302) were also observed. The concentrations of triclosan in sediments of these two rivers seemed stable. On average, triclosan was detected in 86 % of the sediment samples with a range from Triclosan in surface water and sediments of the tropical rivers might be rapidly photolyzed due to plenty of sunshine. It is worth to further investigate the occurrence and fate of triclosan photoproduct in the aquatic environment of the tropics.

  5. Triclosan Induces Thymic Stromal Lymphopoietin in Skin Promoting Th2 Allergic Responses.

    Science.gov (United States)

    Marshall, Nikki B; Lukomska, Ewa; Long, Carrie M; Kashon, Michael L; Sharpnack, Douglas D; Nayak, Ajay P; Anderson, Katie L; Jean Meade, B; Anderson, Stacey E

    2015-09-01

    Triclosan is an antimicrobial chemical incorporated into many personal, medical and household products. Approximately, 75% of the U.S. population has detectable levels of triclosan in their urine, and although it is not typically considered a contact sensitizer, recent studies have begun to link triclosan exposure with augmented allergic disease. We examined the effects of dermal triclosan exposure on the skin and lymph nodes of mice and in a human skin model to identify mechanisms for augmenting allergic responses. Triclosan (0%-3%) was applied topically at 24-h intervals to the ear pinnae of OVA-sensitized BALB/c mice. Skin and draining lymph nodes were evaluated for cellular responses and cytokine expression over time. The effects of triclosan (0%-0.75%) on cytokine expression in a human skin tissue model were also examined. Exposure to triclosan increased the expression of TSLP, IL-1β, and TNF-α in the skin with concomitant decreases in IL-25, IL-33, and IL-1α. Similar changes in TSLP, IL1B, and IL33 expression occurred in human skin. Topical application of triclosan also increased draining lymph node cellularity consisting of activated CD86(+)GL-7(+) B cells, CD80(+)CD86(+) dendritic cells, GATA-3(+)OX-40(+)IL-4(+)IL-13(+) Th2 cells and IL-17 A(+) CD4 T cells. In vivo antibody blockade of TSLP reduced skin irritation, IL-1β expression, lymph node cellularity, and Th2 responses augmented by triclosan. Repeated dermal exposure to triclosan induces TSLP expression in skin tissue as a potential mechanism for augmenting allergic responses.

  6. Effect of cations on the solubilization/deposition of triclosan in sediment-water-rhamnolipid system.

    Science.gov (United States)

    Chen, Yuanbo; Hu, Yongyou; Guo, Qian; Yan, Jia; Wu, Wenjin

    2016-09-01

    Cations had great influence on the self-assembly of rhamnolipid, which in turn affected the fate of triclosan. The migration of triclosan from sediment to water benefited its biodegradation but it could be transformed into more toxic compounds. To regulate the fate of triclosan and reduce environmental risks extremely, the effect of four common cations in surface water (Na(+)/K(+)/Ca(2+)/Mg(2+)) on the solubilization/deposition of triclosan in sediment-water-rhamnolipid system was investigated. The interaction among cations, triclosan and rhamnolipid was explored based on self-assembly of rhamnolipid and water solubility of triclosan in rhamnolipid solutions. Results showed that cations had little influence on the fate of triclosan in the absence of rhamnolipid. Cations, especially Ca(2+)/Mg(2+), reduced the critical micelle concentration, micellar size and zeta potential of rhamnolipid solutions. The changes in self-assembly of rhamnolipid with different cations led to the difference of residual rhamnolipid concentration in water, which was nearly invariant with 0.01 M Na(+)/K(+) while decreased significantly with 0.01 M Ca(2+)/Mg(2+). Consequently, water solubility of triclosan in rhamnolipid solutions increased with the addition of Na(+)/K(+) whereas decreased with Ca(2+)/Mg(2+). In sediment-water- rhamnolipid system, triclosan was slightly solubilized from sediment to water with Na(+)/K(+) while deposited in sediment with Ca(2+)/Mg(2+). These findings provided an alternative application of rhamnolipid for the remediation of triclosan-polluted sediment. Copyright © 2016. Published by Elsevier Ltd.

  7. Bactericidal antibiotics induce programmed metabolic toxicity

    Directory of Open Access Journals (Sweden)

    Aislinn D. Rowan

    2016-03-01

    Full Text Available The misuse of antibiotics has led to the development and spread of antibiotic resistance in clinically important pathogens. These resistant infections are having a significant impact on treatment outcomes and contribute to approximately 25,000 deaths in the U.S. annually. If additional therapeutic options are not identified, the number of annual deaths is predicted to rise to 317,000 in North America and 10,000,000 worldwide by 2050. Identifying therapeutic methodologies that utilize our antibiotic arsenal more effectively is one potential way to extend the useful lifespan of our current antibiotics. Recent studies have indicated that modulating metabolic activity is one possible strategy that can impact the efficacy of antibiotic therapy. In this review, we will address recent advances in our knowledge about the impacts of bacterial metabolism on antibiotic effectiveness and the impacts of antibiotics on bacterial metabolism. We will particularly focus on two studies, Lobritz, et al. (PNAS, 112(27: 8173-8180 and Belenky et al. (Cell Reports, 13(5: 968–980 that together demonstrate that bactericidal antibiotics induce metabolic perturbations that are linked to and required for bactericidal antibiotic toxicity.

  8. Serum and blister fluid pharmacokinetics and bactericidal activities of ampicillin-sulbactam, cefotetan, cefoxitin, ceftizoxime, and ticarcillin-clavulanate.

    Science.gov (United States)

    Jaresko, G S; Barriere, S L; Johnson, B L

    1992-01-01

    Ampicillin-sulbactam, ticarcillin-clavulanate, cefoxitin, cefotetan, and ceftizoxime are promoted for the treatment of mixed aerobic-anaerobic bacterial infections. Their activities have been compared in vitro but not in vivo. In order to assess the in vivo activities of these agents in serum and interstitial fluid, we administered single, intravenous doses of these antimicrobial agents to healthy subjects. Concentrations of the antimicrobial agents in serum and suction-induced blister fluid and bactericidal activity were measured by high-pressure liquid chromatography and the standard methodology of the National Committee for Clinical Laboratory Standards, respectively. The organisms used for bactericidal activity tests were one isolate each of Staphylococcus aureus, Klebsiella pneumoniae, and Bacteroides fragilis. Pharmacokinetic parameters in serum and blister fluid were similar to those derived in other investigations. Of note were the high and prolonged concentrations of ticarcillin and cefotetan in blister fluid, despite high-level serum protein binding. The bactericidal activities in serum and blister fluid reflected the relative in vitro activities and kinetic dispositions of the various antimicrobial agents except for the bactericidal activity of cefotetan, which was substantially lower in blister fluid than serum, despite a blister fluid:serum area under the concentration-time curve ratio of 1.5. Similarly, the activity of ticarcillin-clavulanate in blister fluid was also substantially less than would have been predicted by the blister fluid:serum ratio of the area under the concentration-time curve of 1.1, possibly because of the low concentrations of clavulanate in blister fluid. The rankings of the in vivo bactericidal activities of the five drugs were as follows: for S. aureus, ampicillin-sulbactam > ticarcillin-clavulanate > ceftizoxime > cefoxitin > cefotetan; for K. pneumoniae, ceftizoxime > cefotetan > ampicillin-sulbactam = ticarcillin

  9. Impairment of the Bacterial Biofilm Stability by Triclosan

    Science.gov (United States)

    Hubas, Cédric; Behrens, Sebastian; Ricciardi, Francesco; Paterson, David M.

    2012-01-01

    The accumulation of the widely-used antibacterial and antifungal compound triclosan (TCS) in freshwaters raises concerns about the impact of this harmful chemical on the biofilms that are the dominant life style of microorganisms in aquatic systems. However, investigations to-date rarely go beyond effects at the cellular, physiological or morphological level. The present paper focuses on bacterial biofilms addressing the possible chemical impairment of their functionality, while also examining their substratum stabilization potential as one example of an important ecosystem service. The development of a bacterial assemblage of natural composition – isolated from sediments of the Eden Estuary (Scotland, UK) – on non-cohesive glass beads (<63 µm) and exposed to a range of triclosan concentrations (control, 2 – 100 µg L−1) was monitored over time by Magnetic Particle Induction (MagPI). In parallel, bacterial cell numbers, division rate, community composition (DGGE) and EPS (extracellular polymeric substances: carbohydrates and proteins) secretion were determined. While the triclosan exposure did not prevent bacterial settlement, biofilm development was increasingly inhibited by increasing TCS levels. The surface binding capacity (MagPI) of the assemblages was positively correlated to the microbial secreted EPS matrix. The EPS concentrations and composition (quantity and quality) were closely linked to bacterial growth, which was affected by enhanced TCS exposure. Furthermore, TCS induced significant changes in bacterial community composition as well as a significant decrease in bacterial diversity. The impairment of the stabilization potential of bacterial biofilm under even low, environmentally relevant TCS levels is of concern since the resistance of sediments to erosive forces has large implications for the dynamics of sediments and associated pollutant dispersal. In addition, the surface adhesive capacity of the biofilm acts as a sensitive measure of

  10. Impairment of the bacterial biofilm stability by triclosan.

    Directory of Open Access Journals (Sweden)

    Helen V Lubarsky

    Full Text Available The accumulation of the widely-used antibacterial and antifungal compound triclosan (TCS in freshwaters raises concerns about the impact of this harmful chemical on the biofilms that are the dominant life style of microorganisms in aquatic systems. However, investigations to-date rarely go beyond effects at the cellular, physiological or morphological level. The present paper focuses on bacterial biofilms addressing the possible chemical impairment of their functionality, while also examining their substratum stabilization potential as one example of an important ecosystem service. The development of a bacterial assemblage of natural composition--isolated from sediments of the Eden Estuary (Scotland, UK--on non-cohesive glass beads (<63 µm and exposed to a range of triclosan concentrations (control, 2-100 µg L(-1 was monitored over time by Magnetic Particle Induction (MagPI. In parallel, bacterial cell numbers, division rate, community composition (DGGE and EPS (extracellular polymeric substances: carbohydrates and proteins secretion were determined. While the triclosan exposure did not prevent bacterial settlement, biofilm development was increasingly inhibited by increasing TCS levels. The surface binding capacity (MagPI of the assemblages was positively correlated to the microbial secreted EPS matrix. The EPS concentrations and composition (quantity and quality were closely linked to bacterial growth, which was affected by enhanced TCS exposure. Furthermore, TCS induced significant changes in bacterial community composition as well as a significant decrease in bacterial diversity. The impairment of the stabilization potential of bacterial biofilm under even low, environmentally relevant TCS levels is of concern since the resistance of sediments to erosive forces has large implications for the dynamics of sediments and associated pollutant dispersal. In addition, the surface adhesive capacity of the biofilm acts as a sensitive measure of

  11. Biosynthesis of Antitumoral and Bactericidal Sanguinarine

    Science.gov (United States)

    García, Víctor P.; Valdés, F.; Martín, R.; Luis, J. C.; Afonso, A. M.; Ayala, J. H.

    2006-01-01

    A simple, rapid, and reliable TLC method for the separation and determination of sanguinarine has been established. This intensively studied biologically active alkaloid has a wide range of potentially useful medicinal properties, such as antimicrobial, antiinflammatory, and antitumoral activities. Sanguinarine has also been incorporated into expectorant mixtures and has a strong bactericidal effect upon gram-positive bacteria, particularly Bacillus anthracis and staphylococci. These medicinal properties are due to the interaction of sanguinarine with DNA. A fibre-optic-based fluorescence instrument for in situ scanning was used for quantitative measurements. The sanguinarine was determined over the range 5–40 ng and a detection limit of 1.60 ng. The method was applied to the quantification of sanguinarine in tissue culture extracts of Chelidonium majus L. PMID:16883053

  12. Residual water bactericide monitor development program

    Science.gov (United States)

    1973-01-01

    A silver-ion bactericidal monitor is considered for the Space Shuttle Potable Water System. Potentiometric measurement using an ion-selective electrode is concluded to be the most feasible of available techniques. Four commercially available electrodes and a specially designed, solid-state, silver-sulfide electrode were evaluated for their response characteristics and suitability for space use. The configuration of the solid-state electrode with its Nernstian response of 10 to 10,000 ppb silver shows promise for use in space. A pressurized double-junction reference electrode with a quartz-fiber junction and a replaceable bellows electrolyte reservoir was designed verification-tested, and paired with a solid-state silver-sulfide electrode in a test fixture.

  13. Occurrence of triclosan in plasma of wild Atlantic bottlenose dolphins (Tursiops truncatus) and in their environment.

    Science.gov (United States)

    Fair, Patricia A; Lee, Hing-Biu; Adams, Jeff; Darling, Colin; Pacepavicius, Grazina; Alaee, Mehran; Bossart, Gregory D; Henry, Natasha; Muir, Derek

    2009-01-01

    The presence of triclosan, a widely-used antibacterial chemical, is currently unknown in higher trophic-level species such as marine mammals. Blood plasma collected from wild bottlenose dolphins (Tursiops truncatus) in Charleston, SC (CHS) (n = 13) and Indian River Lagoon, FL (IRL) (n = 13) in 2005 was analyzed for triclosan. Plasma concentrations in CHS dolphins ranged from 0.12 to 0.27 ng/g wet weight (mean 0.18 ng/g), with 31% of the sampled individuals having detectable triclosan. The mean IRL dolphin plasma concentrations were 0.072 ng/g wet weight (range 0.025-0.11 ng/g); 23% of the samples having detectable triclosan. In the CHS area, triclosan effluent values from two WWTP were both 190 ng/L and primary influents were 2800 ng/L and 3400 ng/L. Triclosan values in CHS estuarine surface water samples averaged 7.5 ng/L (n = 18) ranging from 4.9 to 14 ng/L. This is the first study to report bioaccumulation of anthropogenic triclosan in a marine mammal highlighting the need for further monitoring and assessment.

  14. Effects of triclosan on bacterial community composition and 'Vibrio' populations in natural seawater microcosms

    Directory of Open Access Journals (Sweden)

    Keri Ann Lydon

    2017-05-01

    Full Text Available Pharmaceuticals and personal care products, including antimicrobials, can be found at trace levels in treated wastewater effluent. Impacts of chemical contaminants on coastal aquatic microbial community structure and pathogen abundance are unknown despite the potential for selection through antimicrobial resistance. In particular, 'Vibrio', a marine bacterial genus that includes several human pathogens, displays resistance to the ubiquitous antimicrobial compound triclosan. Here we demonstrated through use of natural seawater microcosms that triclosan (at a concentration of ~5 ppm can induce a significant 'Vibrio' growth response (68–1,700 fold increases in comparison with no treatment controls for three distinct coastal ecosystems: Looe Key Reef (Florida Keys National Marine Sanctuary, Doctors Arm Canal (Big Pine Key, FL, and Clam Bank Landing (North Inlet Estuary, Georgetown, SC. Additionally, microbial community analysis by 16 S rRNA gene sequencing for Looe Key Reef showed distinct changes in microbial community structure with exposure to 5 ppm triclosan, with increases observed in the relative abundance of 'Vibrio'naceae (17-fold, Pseudoalteromonadaceae (65-fold, Alteromonadaceae (108-fold, Colwelliaceae (430-fold, and Oceanospirillaceae (1,494-fold. While the triclosan doses tested were above concentrations typically observed in coastal surface waters, results identify bacterial families that are potentially resistant to triclosan and/or adapted to use triclosan as a carbon source. The results further suggest the potential for selection of 'Vibrio' in coastal environments, especially sediments, where triclosan may accumulate at high levels.

  15. Improving the aqueous solubility of triclosan by solubilization, complexation, and in situ salt formation.

    Science.gov (United States)

    Grove, Christine; Liebenberg, Wilna; du Preez, Jan L; Yang, Wenzhan; de Villiers, Melgardt M

    2003-01-01

    Triclosan, an antimicrobial, although widely incorporated into many skin care products, toothpastes, and liquid soaps, presents formulation difficulties because it is practically insoluble in water. The objective of this study was to improve the aqueous solubility of triclosan through solubilization, complexation, and salt formation. The solubility of triclosan in distilled water and in phosphate buffers (pH 7.4) was determined at 30 degrees C. The order of solubilizing performance of the solubilizers was: N-methylglucamine> or =L-arginine>sodium lauryl sulfate>beta-cyclodextrin> or =hydroxypropyl-beta-cyclodextrin>ethanolamine>sodium benzoate>sodium methyl 4-hydroxybenzoate>triethanolamine> or =diethanolamine. These solubilizers increased the solubility of triclosan from 80- to 6000-fold. Micellar solubilization and the formation of either salts or complexes are postulated as possible mechanisms for the increase in the solubility of triclosan by the surfactant sodium lauryl sulphate, the cyclic sugar derivatives beta-cyclodextrin and 2-hydropropyl-beta-cyclodextrin, the amino acid L-arginine, and the amino sugar alcohol N-methylglucamine. Furthermore, although the bacteriostatic efficacy of triclosan was significantly increased when solubilized with N-methylglucamine, L-arginine, and ethanolamine, increased solubilization did not increase the effectiveness of triclosan for all solubilizers tested.

  16. The HR96 activator, atrazine, reduces sensitivity of D. magna to triclosan and DHA.

    Science.gov (United States)

    Sengupta, Namrata; Litoff, Elizabeth J; Baldwin, William S

    2015-06-01

    HR96 is a CAR/PXR/VDR ortholog in invertebrates, and a promiscuous endo- and xenobiotic nuclear receptor involved in acclimation to toxicants. Daphnia HR96 is activated by chemicals such as atrazine and linoleic acid (LA) (n-6 fatty acid), and inhibited by triclosan and docosahexaenoic acid (DHA) (n-3 fatty acid). We hypothesized that inhibitors of HR96 may block the protective responses of HR96 based on previously performed luciferase assays. Therefore, we performed acute toxicity tests with two-chemical mixtures containing a HR96 inhibitor (DHA or triclosan) and a HR96 activator (LA or atrazine). Surprisingly, results demonstrate that triclosan and DHA are less toxic when co-treated with 20-80 μM atrazine. Atrazine provides concentration-dependent protection as lower concentrations have no effect and higher concentrations cause toxicity. LA, a weaker HR96 activator, did not provide protection from triclosan or DHA. Atrazine's protective effects are presumably due to its ability to activate HR96 or other toxicologically relevant transcription factors and induce protective enzymes. Atrazine did not significantly induce glucosyltransferase, a crucial enzyme in triclosan detoxification. However, atrazine did increase antioxidant activities, crucial pathways in triclosan's toxicity, as measured through GST activity and the TROLOX equivalence assay. The increase in antioxidant capacity is consistent with atrazine providing protection from a wide range of toxicants that induce ROS, including triclosan and unsaturated fatty acids predisposed to lipid peroxidation.

  17. Bacteria survival probability in bactericidal filter paper.

    Science.gov (United States)

    Mansur-Azzam, Nura; Hosseinidoust, Zeinab; Woo, Su Gyeong; Vyhnalkova, Renata; Eisenberg, Adi; van de Ven, Theo G M

    2014-05-01

    Bactericidal filter papers offer the simplicity of gravity filtration to simultaneously eradicate microbial contaminants and particulates. We previously detailed the development of biocidal block copolymer micelles that could be immobilized on a filter paper to actively eradicate bacteria. Despite the many advantages offered by this system, its widespread use is hindered by its unknown mechanism of action which can result in non-reproducible outcomes. In this work, we sought to investigate the mechanism by which a certain percentage of Escherichia coli cells survived when passing through the bactericidal filter paper. Through the process of elimination, the possibility that the bacterial survival probability was controlled by the initial bacterial load or the existence of resistant sub-populations of E. coli was dismissed. It was observed that increasing the thickness or the number of layers of the filter significantly decreased bacterial survival probability for the biocidal filter paper but did not affect the efficiency of the blank filter paper (no biocide). The survival probability of bacteria passing through the antibacterial filter paper appeared to depend strongly on the number of collision between each bacterium and the biocide-loaded micelles. It was thus hypothesized that during each collision a certain number of biocide molecules were directly transferred from the hydrophobic core of the micelle to the bacterial lipid bilayer membrane. Therefore, each bacterium must encounter a certain number of collisions to take up enough biocide to kill the cell and cells that do not undergo the threshold number of collisions are expected to survive. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Evaluation of anti-gingivitis benefits of stannous fluoride dentifrice among triclosan dentifrice users.

    Science.gov (United States)

    He, Tao; Barker, Matthew L; Biesbrock, Aaron; Miner, Melanie; Amini, Pejmon; Goyal, C Ram; Qaqish, Jimmy

    2013-08-01

    To evaluate the anti-gingivitis benefits of a 0.454% highly bioavailable stannous fluoride dentifrice (SnF2) relative to a 0.3% triclosan/copolymer dentifrice (triclosan/copolymer) among triclosan/copolymer dentifrice users with residual gingivitis. This was a randomized, controlled, double-blind, parallel group, 2-month clinical study. Self-reported triclosan/copolymer dentifrice users were recruited and provided with triclosan/copolymer dentifrice to use for 1 month. After this 1-month acclimation period, subjects who had residual gingivitis at the baseline visit were randomized to either the SnF2 dentifrice or the triclosan/copolymer dentifrice (positive control). Subjects performed their treatment unsupervised using their assigned dentifrice following manufacturers' usage instructions for 2 months. The Gingival Bleeding Index (GBI) and Modified Gingival Index (MGI) were used to measure gingivitis benefits at baseline and Month 2. An analysis of covariance was performed to compare treatment groups for the post-baseline scores as well as change from baseline, with the baseline score as a covariate. All comparisons were two-sided at the 0.05 level of significance. A total of 150 subjects were randomized to treatment. Both treatment groups experienced significant reductions in number of bleeding sites, gingival bleeding index (GBI), and gingival inflammation (MGI) relative to baseline (P dentifrice group demonstrated significantly lower adjusted mean scores versus the triclosan/copolymer group for number of bleeding sites, GBI, and MGI (P < 0.001). Between-treatment group comparisons for change from baseline values showed that the improvement in number of bleeding sites from baseline for the SnF2 group was 49% greater versus that of the triclosan/copolymer group (P < 0.001), and the GBI and MGI improvements from baseline for the SnF2 group were 48% and 37%, greater, respectively, relative to the triclosan/copolymer group (P < 0.001).

  19. Triclosan and methyl-triclosan monitoring study in the northeast of Spain using a magnetic particle enzyme immunoassay and confirmatory analysis by gas chromatography mass spectrometry

    Science.gov (United States)

    Kantiani, Lina; Farré, Marinella; Asperger, Danijela; Rubio, Fernando; González, Susana; López de Alda, Maria J.; Petrović, Mira; Shelver, Weilin L.; Barceló, Damià

    2008-10-01

    SummaryFor the first time, the occurrence of triclosan and its metabolite methyl-triclosan was investigated in a typical Mediterranean area using a two-step methodology based on screening using a magnetic particle immunoassay (IA) and confirmatory analysis by solid phase extraction (SPE) followed by gas chromatography-mass spectrometry (GC-MS). In this study, 95 environmental samples were analyzed. A commercial immunoassay was assessed for use in the different types of water selected for this study. A large monitoring study was performed on the influent and the effluent of eight wastewater treatment plants (WWTPs), water samples from Ebro and Llobregat rivers, and drinking water. All wastewater samples tested in this study (influents and effluents) showed the presence of triclosan, with concentrations for raw influents being high (10 μg/L as average value). The percentages of triclosan removal for the WWTPs were evaluated (30-70%) along the different treatment processes showing that the best removal rates were obtained by the processes equipped with membrane bioreactors (MBRs). However, important concentrations of triclosan were detected even after treatment by MBRs. The presence of this biocide was confirmed in 50% of the river samples analyzed. Twenty two drinking water samples from the Barcelona city area were investigated, and in this case no triclosan was detected. Due to its properties and the widespread usage of triclosan, there is a need for monitoring and controlling the amounts present in wastewater effluents, river water, drinking water catchments areas, and drinking water. To this end, we present a feasible methodology using a magnetic particle-based immunoassay as a screening, followed by confirmatory analysis using solid phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS).

  20. [Study on synergistic effect of bactericidal effect of chlorine dioxide solution by surfactant].

    Science.gov (United States)

    Wang, Kuitao; Tian, Vuena; Gu, Na; Zhang, Congjing; Niu, Jiajing

    2013-03-01

    To study the effect of gemini fluorocarbon, sodium p-perfluorous nonenoxybenzene sulfonate and sodium dodecyl sulfate on the chlorine dioxide solution sterilization to object surface. Pure chlorine dioxide solution as the reference disinfectant, carrier quantitative bactericidal test and simulated test on-site were used to carry out laboratory observation according to The disinfection technical specifications (2002). Carrier quantitative bactericidal test showed that the addition dosage of gemini fluoronates, sodium dodecyl sulfate surfactant and perfluorinated the nonene oxy benzene sulfonate in disinfectant solution were 60, 60 and 40 mg/L respectively, the killing log value of Staphylococcus aureus exposed to the disinfectant solution containing chlorine dioxide 50 mg/L for 10 mm were all more than 3; and the addition dosage of gemini fluorinates, sodium dodecyl sulfate and perfluorinated the nonene oxy benzene sulfonate in disinfectant solution were 60 mg/L, the killing log value of Escherichia coli exposed to the disinfectant solution containing chlorine dixoxide 20 mg/L for 10 min were all more than 3. The bactericidal effect of the mixture use of surfactant and chlorine dioxide was better than the single use of chlorine dioxide. The simulated test on-site showed that the killing log value of Escherichia coli exposed to the disinfectant solution containing perfluorinated the nonene oxy benzene sulfonate 40 mg/L and chlorine dioxide 20 mg/L for 15 min was more than 3. Surface active agent on germicidal efficacy of chlorine dioxide solution had synergistic action.

  1. In vitro bactericidal activities of Japanese rice-fluid against Helicobacter pylori strains

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Kawakami, Kozue Oana, Masayoshi Hayama, Hiroyoshi Ota, Masahiko Takeuchi, Kazuhiro Miyashita, Tsunetomo Matsuzawa, Kiyomi Kanaya

    2006-01-01

    Full Text Available Background: Helicobacter pylori has now been widely recognized as a causative agent of gastroduodenal diseases. The development of safer anti- H. pylori compounds is desirable due to the antibiotic-resistant strains emerged to date. Methods: We successfully developed the compounds of Rice-fluid derived from unpolished, polished, and usually cooked Japanese rice, and investigated their in vitro antibacterial activities by means of the Time-Kill-Curve methods against various species of bacteria including H. pylori strains. Results: All of the compounds revealed keen bactericidal activities against H. pylori, followed by Streptococcus pneumoniae and Campylobacter jejuni strains, but failed to affect the viability of other bacterial species investigated including staphylococci, enterococci, Pseudomonas aeruginosa, and other gram-negative rods belonging to the family Enterobacteraceae. The bactericidal activities were demonstrated to be time- and concentration-dependent. Conclusions: The compounds of Rice-fluid are considered to be potentially new and safe therapeutic regimens against H. pylori infections. The mechanism of their bactericidal activities against H. pylori strains remains to be elucidated.

  2. Efficacy of triclosan as an antimicrobial hand soap and its potential impact on antimicrobial resistance: a focused review.

    Science.gov (United States)

    Giuliano, Christopher A; Rybak, Michael J

    2015-03-01

    Triclosan is a synthetic biocide found in many household products, including antimicrobial hand soap. Levels of triclosan have been found throughout the environment and in human urine, blood, and even breast milk. Increasing levels of exposure to triclosan have led to concerns over the development of resistance to triclosan and cross-resistance to other antimicrobials. We performed a literature search to assess whether the widespread use of triclosan displays a favorable benefit: risk ratio, defined by evaluation of triclosan's efficacy as an antimicrobial hand soap and its potential effect on the development of antimicrobial resistance. Data from laboratory-based studies regarding the efficacy of triclosan are conflicting, although well-designed studies suggest no significant difference in efficacy over nonantimicrobial soap. In addition, when triclosan was introduced in a community setting, no beneficial effects were observed on the reduction of infections over nonantimicrobial soap. Resistance to triclosan and cross-resistance to antimicrobials have been consistently demonstrated in laboratory settings, although overall resistance rates and cross-resistance rates in the community setting are low. Based on the available evidence, the risk of potential antimicrobial resistance outweighs the benefit of widespread triclosan use in antimicrobial soaps. © 2015 Pharmacotherapy Publications, Inc.

  3. Branched and ionic β-Cyclodextrins multilayer assembling onto polyacrylonitrile membranes for removal and controlled release of triclosan.

    Science.gov (United States)

    Pérez-Álvarez, Leyre; Matas, Janire; Gómez-Galván, Flor; Ruiz-Rubio, Leire; León, Luis M; Vilas-Vilela, Jose Luis

    2017-01-20

    The present study summarizes the formation and characterization of multilayers of polyacrylonitrile (PAN) membranes with β-cyclodextrin derivatives in order to be potentially interesting for triclosan (TR) controlled delivery with antibacterial purposes, as well as, for the removal of TR from wastewater. With this object, cationic and anionic branched β-cyclodextrins (bβCDs) were incorporated by layer-by-layer (LbL) process onto previously synthesized and hydrolyzed PAN membranes. FTIR, XPS and labelling with fluoresceinamine (FA) let to study the formation and stability of the prepared multilayered systems. TR is a widely used antibacterial and antifungal agent with proven ability to inhibit bacterial growth that, however, recently has shown a potential toxicity. The ability of obtained bβCDs/PAN multilayered membranes to retain TR in water was evaluated by two different loading procedures. The delivery kinetic profile of TR from loaded membranes was also analyzed showing the maximum release in the first 24h.

  4. Importance of sigma factor mutations in increased triclosan resistance in Salmonella Typhimurium

    DEFF Research Database (Denmark)

    Gantzhorn, Mette Rørbæk; Olsen, John Elmerdahl; Thomsen, Line Elnif

    2015-01-01

    to disinfectants might lead to decreased susceptibility to antibiotics. The current study aimed to identify genetic changes causing high level triclosan resistance in S. enterica serovar Typhimurium and evaluate how these affected antibiotic resistance and efflux pump activity. RESULTS: Wild type strains S....... Typhimurium 4/74 and DTU3 were adapted to increasing concentrations of the biocide triclosan by serial passage. High level triclosan resistant isolates (MIC > 1000 μg/ml) were obtained. Strains were genome sequenced, and SNPs in fabI, rpoS and rpoD were found to be associated with high level resistance....... However, work with defined mutants revealed that a SNP in fabI was not sufficient to obtain high level resistance. This required additional mutations in the sigma factors rpoS or rpoD. The adapted strains showed triclosan-dependent increased efflux, increased fabI expression and reduced susceptibility...

  5. Triclosan exposure reduces thyroxine levels in pregnant and lactating rat dams and in directly exposed offspring

    DEFF Research Database (Denmark)

    Petersen, Marta Axelstad; Boberg, Julie; Vinggaard, Anne Marie

    2013-01-01

    Thyroid disrupting chemicals can potentially disrupt brain development. Two studies investigating the effect of the antibacterial compound triclosan on thyroxine (T4) levels in rats are reported. In the first, Wistar rat dams were gavaged with 75, 150 or 300 mg triclosan/kg bw/day throughout...... gestation and lactation. Total T4 serum levels were measured in dams and offspring, and all doses of triclosan significantly lowered T4 in dams, but no significant effects on T4 levels were seen in the offspring at the end of the lactation period. Since this lack of effect could be due to minimal exposure...... through maternal milk, a second study using direct per oral pup exposure from postnatal day 3–16 to 50 or 150 mg triclosan/kg bw/day was performed. This exposure pointed to significant T4 reductions in 16 day old offspring in both dose groups. These results corroborate previous studies showing...

  6. Evidence for triclosan-induced activation of human and rodent xenobiotic nuclear receptors

    Science.gov (United States)

    The bacteriostat triclosan (2,4,40-trichloro-20-hydroxydiphenylether) (TCS) decreases rat serum thyroxine via putative nuclear receptor (NR) interaction(s) and subsequent transcriptional up-regulation of hepatic catabolism and clearance. However, due to the evolutionary divergenc...

  7. Triclosan-loaded poly(amido amine) dendrimer for simultaneous treatment and remineralization of human dentine.

    Science.gov (United States)

    Zhou, Yan; Yang, Jiaojiao; Lin, Zaifu; Li, Jiyao; Liang, Kunneng; Yuan, He; Li, Sheyu; Li, Jianshu

    2014-03-01

    In order to treat dental caries of damaged dentine, triclosan-loaded carboxyl-terminated poly(amido amine) dendrimer (PAMAM-COOH) is prepared and characterized. While being incubated in artificial saliva, triclosan-loaded PAMAM-COOH formulation can induce in situ remineralization of hydroxyapatite (HA) on etched dentine, and the regenerated HA has a similar crystal structure with natural dentine. It can also release the encapsulated triclosan for a long period. The interesting drug release profiles are controlled by both dendrimer encapsulation capability and the mineralization degree, which are ideal to obtain multifunctional properties of long-term release of anti-bacterial drug for local treatment during the remineralization process. The triclosan-loaded G4-COOH provides a general strategy to cure dental caries and repair damaged dentine at the same time, which forms a potential restorative material for dental repair.

  8. Importance of sigma factor mutations in increased triclosan resistance in Salmonella Typhimurium

    DEFF Research Database (Denmark)

    Gantzhorn, Mette Rørbæk; Olsen, John Elmerdahl; Thomsen, Line Elnif

    2015-01-01

    . Typhimurium 4/74 and DTU3 were adapted to increasing concentrations of the biocide triclosan by serial passage. High level triclosan resistant isolates (MIC > 1000 μg/ml) were obtained. Strains were genome sequenced, and SNPs in fabI, rpoS and rpoD were found to be associated with high level resistance....... However, work with defined mutants revealed that a SNP in fabI was not sufficient to obtain high level resistance. This required additional mutations in the sigma factors rpoS or rpoD. The adapted strains showed triclosan-dependent increased efflux, increased fabI expression and reduced susceptibility...... towards the antibiotics enrofloxacin and sulphamethoxazole/trimethoprim. CONCLUSIONS: Medium level triclosan resistance could be obtained by fabI mutations in S. Typhimurium, however, high level resistance was found to require sigma factor mutations in addition to a fabI mutation. Reduced antibiotic...

  9. Triclosan and Hydroxylated Polybrominated Diphenyl Ethers in Lake and Esturaine Sediments

    Science.gov (United States)

    Arnold, W. A.; Kerrigan, J. F.; McNeill, K.; Erickson, P. R.; Grandbois, M.

    2014-12-01

    Halogenated diphenyl ethers are a class of emerging contaminants that includes the antibacterial compound triclosan and the flame retardant polybrominated diphenyl ethers (PBDEs). Both triclosan and hydroxylated polybrominated diphenyl ethers (OH-BDEs) are known to form dioxins when exposed to sunlight in aqueous solution. Thus, it is important to understand the sources and presence of these compounds in the environment, especially because OH-BDEs are breakdown products of PBDEs and also naturally produced compounds. In this work, the levels of OH-BDEs were determined in lake sediments from Minnesota and esturaine sediments from San Francisco Bay. Both surface sediments over a broad spatial area and sediment cores were collected and analyzed. Triclosan was used as a marker of wastewater as a source of the targeted emerging contaminants. The relationship between triclosan and OH-BDE levels provides insight into the importance of natural and anthropogenic influences on the levels of OH-BDEs.

  10. Update on antibacterial soaps: the FDA takes a second look at triclosans.

    Science.gov (United States)

    Bergstrom, Kendra Gail

    2014-04-01

    In December of 2013 the Food and Drug Administration announced it would look further into the safety and efficacy of the biocide triclosan and requested further safety data as part of a new review with the Environmental Protection Agency. The use of triclosan has increased exponentially since its introduction in in 1972, to the point that 75% of commercial soap brands contain triclosan and 76% of a nationwide sample of adults and children excrete triclosan in the urine. This announcement raised an important dialog about the appropriate use of all over the counter biocides. Particular concerns include whether these biocides are more effective than regular soaps, whether they may create new drug resistant bacteria, and whether they may also act as hormone disruptors in humans or the environment.

  11. Comparative evaluation of microleakage in conventional glass ionomer cements and triclosan incorporated glass ionomer cements

    Directory of Open Access Journals (Sweden)

    Rani Somani

    2014-01-01

    Full Text Available Aim and Objective: The aim of the following study is to comparatively evaluate the microleakage of triclosan incorporated GIC with conventional restorative GIC. Materials and Methods: Triclosan in powder form was added to conventional GIC to formulate a concentration of 2.5%. Class five cavities were prepared in non-carious extracted molars and were respectively restored with conventional restorative GIC and triclosan incorporated GIC. Samples were kept in 10% methylene blue dye. Ground sections were obtained and were observed under a binocular microscope for dye penetration. Result: No significant difference was found in the microleakage of two groups. Conclusion: Triclosan incorporated GIC can be considered as an alternative to GIC with enhanced antibacterial property.

  12. Assessment of toxic effects of triclosan on the terrestrial snail (Achatina fulica).

    Science.gov (United States)

    Wang, Xiaonan; Liu, Zhengtao; Wang, Wanhua; Yan, Zhenguang; Zhang, Cong; Wang, Weili; Chen, Lihong

    2014-08-01

    Triclosan (TCS) is a broad-spectrum antimicrobial agent used in personal care products, and as a result, is widespread in the environment. Toxicity tests of TCS on aquatic organisms have been reported, but limited toxicity data on terrestrial species are available. In this study, the 28-d chronic toxicity of TCS on the biomass, shell diameter growth, and total food intake of the terrestrial snail Achatina fulica were tested. Moreover, biochemical responses, including changes in the activity of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and the content of malondialdehyde (MDA), were examined after 14-d and 28-d exposure. Results showed that TCS had toxic effects on the biomass, shell diameter growth, and total food intake of A. fulica with no observed effect concentration (NOEC) values of 24 mg kg(-1). As for the antioxidant enzymes, TCS caused significant oxidative stress even at the low concentration of 24 mg kg(-1). The CAT and POD activities at the high concentrations of 200 and 340 mg kg(-1), respectively, were significantly inhibited. The SOD and CAT activity in treatments below 118 mg kg(-1) and the MDA content in all treatments showed dose-effect relationships. This study demonstrated that TCS caused adverse effects on terrestrial invertebrates, and provided valuable information for the risk assessment imposed by TCS in the terrestrial environment.

  13. Triclosan causes spontaneous abortion accompanied by decline of estrogen sulfotransferase activity in humans and mice.

    Science.gov (United States)

    Wang, Xiaoli; Chen, Xiaojiao; Feng, Xuejiao; Chang, Fei; Chen, Minjian; Xia, Yankai; Chen, Ling

    2015-12-15

    Triclosan (TCS), an antibacterial agent, is identified in serum and urine of humans. Here, we show that the level of urinary TCS in 28.3% patients who had spontaneous abortion in mid-gestation were increased by 11.3-fold (high-TCS) compared with normal pregnancies. Oral administration of TCS (10 mg/kg/day) in mice (TCS mice) caused an equivalent urinary TCS level as those in the high-TCS abortion patients. The TCS-exposure from gestation day (GD) 5.5 caused dose-dependently fetal death during GD12.5-16.5 with decline of live fetal weight. GD15.5 TCS mice appeared placental thrombus and tissue necrosis with enhancement of platelet aggregation. The levels of placenta and plasma estrogen sulfotransferase (EST) mRNA and protein in TCS mice or high-TCS abortion patients were not altered, but their EST activities were significantly reduced compared to controls. Although the levels of serum estrogen (E2) in TCS mice and high-TCS abortion patients had no difference from controls, their ratio of sulfo-conjugated E2 and unconjugated E2 was reduced. The estrogen receptor antagonist ICI-182,780 prevented the enhanced platelet aggregation and placental thrombosis and attenuated the fetal death in TCS mice. The findings indicate that TCS-exposure might cause spontaneous abortion probably through inhibition of EST activity to produce placental thrombosis.

  14. The impact of triclosan on the spread of antibiotic resistance in the environment

    Directory of Open Access Journals (Sweden)

    Daniel E Carey

    2015-01-01

    Full Text Available Triclosan (TCS is a commonly used antimicrobial agent that enters wastewater treatment plants (WWTPs and the environment. An estimated 1.1x105 to 4.2x105 kg of TCS are discharged from these WWTPs per year in the United States. The abundance of TCS along with its antimicrobial properties have given rise to concern regarding its impact on antibiotic resistance in the environment. The objective of this review is to assess the state of knowledge regarding the impact of TCS on multidrug resistance in environmental settings, including engineered environments such as anaerobic digesters. Pure culture studies are reviewed in this paper to gain insight into the substantially smaller body of research surrounding the impacts of TCS on environmental microbial communities. Pure culture studies, mainly on pathogenic strains of bacteria, demonstrate that TCS is often associated with multidrug resistance. Research is lacking to quantify the current impacts of TCS discharge to the environment, but it is known that resistance to TCS and multidrug resistance can increase in environmental microbial communities exposed to TCS. Research plans are proposed to quantitatively define the conditions under which TCS selects for multidrug resistance in the environment.

  15. Differential gene expression patterns during embryonic development of sea urchin exposed to triclosan.

    Science.gov (United States)

    Hwang, Jinik; Suh, Sung-Suk; Park, Mirye; Park, So Yun; Lee, Sukchan; Lee, Taek-Kyun

    2017-02-01

    Triclosan (TCS; 2,4,4'-trichloro-2'-hydroxydiphenyl ether) is a broad-spectrum antibacterial agent used in common industrial, personal care and household products which are eventually rinsed down the drain and discharged with wastewater effluent. It is therefore commonly found in the aquatic environment, leading to the continual exposure of aquatic organisms to TCS and the accumulation of the antimicrobial and its harmful degradation products in their bodies. Toxic effects of TCS on reproductive and developmental progression of some aquatic organisms have been suggested but the underlying molecular mechanisms have not been defined. We investigated the expression patterns of genes involved in the early development of TCS-treated sea urchin Strongylocentrotus nudus using cDNA microarrays. We observed that the predominant consequence of TCS treatment in this model system was the widespread repression of TCS-modulated genes. In particular, empty spiracles homeobox 1 (EMX-1), bone morphogenic protein, and chromosomal binding protein genes showed a significant decrease in expression in response to TCS. These results suggest that TCS can induce abnormal development of sea urchin embryos through the concomitant suppression of a number of genes that are necessary for embryonic differentiation in the blastula stage. Our data provide new insight into the crucial role of genes associated with embryonic development in response to TCS. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 426-433, 2017.

  16. Study on the sorption process of triclosan on cationic microfibrillated cellulose and its antibacterial activity.

    Science.gov (United States)

    Zhang, Hongjie; Zeng, Xu; Xie, Jinglei; Li, Zhiqiang; Li, Hailong

    2016-01-20

    Cationic microfibrillated cellulose (CMFC), as one kind of cellulose-based materials, is widely used in many fields. In this work, it was functionalized with a traditional antibacterial agent (triclosan, TCS). The sorption process of TCS onto CMFC was expressed by kinetic and isotherm models. The results showed that there was a high correlation coefficient (R(2)>0.9) in the pseudo-second-order model and the isotherm models, indicating that CMFC had a good sorption capacity for TCS. The sorption type was chemisorption, and the reaction power was electrostatic interactions. The antibacterial activity of the assembled TCS/CMFC compound was tested by disk diffusion method, and it was found a higher antibacterial activity than CMFC alone (bigger inhibition zone diameters). Further, the functionalized TCS/CMFC compound was used in the fiber network during handsheets making, and it had a higher antibacterial rate than TCS alone (increase by 45.1% against Escherichia coli and by 54.8% against Staphylococcus aureus, respectively).

  17. Assessment of the antibacterial activity of a triclosan-containing cutting board.

    Science.gov (United States)

    Møretrø, Trond; Høiby-Pettersen, Gunn S; Habimana, Olivier; Heir, Even; Langsrud, Solveig

    2011-03-30

    Several studies have shown that consumers may not clean cutting boards properly between preparation of raw and cooked meat. Cutting boards may therefore act as sources for contamination of cooked meat or other ready-to-eat foods with pathogenic and spoilage bacteria. The aim of the work was to investigate if cutting boards containing the antimicrobial compound triclosan can reduce the viability of bacteria, thus acting as a hygiene barrier. Survival and growth of food pathogens and spoilage bacteria on two cutting boards without antimicrobials and a commercial cutting board containing triclosan were tested. No difference in bacterial counts on cutting boards without and with triclosan was found after exposure to naturally contaminated chicken filets for one hour. Pathogenic and spoilage bacteria were inoculated on coupons (6.7-7 log per coupon) of cutting boards and incubated at 25°C at controlled relative humidity for 24 and 72 h. At a relative humidity of 100%, growth of Escherichia coli, Salmonella, Staphylococcus aureus, coagulase-negative staphylococci (CNS) and Serrratia spp. was observed and no antibacterial effect of the triclosan-containing board was found except for against Listeria monocytogenes. At lower humidity (70% RH) less growth was found on the triclosan-containing cutting board than untreated boards after 24h. After 72 h of incubation, cell counts were reduced on triclosan-containing boards, with the most pronounced antibacterial effects observed against Salmonella, S. aureus and CNS. For S. aureus and Salmonella it was found that when a lower initial cell count was applied (3.5 log per coupon), the triclosan-containing board had an antibacterial effect under humid conditions, as well as a more pronounced antibacterial effect under dry conditions. An agar overlay assay showed that triclosan migrated out of the coupons. Repeated washing of the triclosan-containing cutting boards reduced the antibacterial effect, thus the amount of triclosan

  18. Prenatal Triclosan Exposure and Anthropometric Measures Including Anogenital Distance in Danish Infants

    Science.gov (United States)

    Lassen, Tina Harmer; Frederiksen, Hanne; Kyhl, Henriette Boye; Swan, Shanna H.; Main, Katharina M.; Andersson, Anna-Maria; Lind, Dorte Vesterholm; Husby, Steffen; Wohlfahrt-Veje, Christine; Skakkebæk, Niels E.; Jensen, Tina Kold

    2016-01-01

    Background: Triclosan (TCS) is widely used as an antibacterial agent in consumer products such as hand soap and toothpaste, and human exposure is widespread. TCS is suspected of having endocrine-disrupting properties, but few human studies have examined the developmental effects of prenatal TCS exposure. Objectives: We prospectively examined associations between prenatal TCS exposure and anthropometric measures at birth and anogenital distance (AGD) at 3 months of age. Methods: Pregnant women from the Odense Child Cohort (n = 514) provided urine samples at approximately gestational week 28 (median 28.7 weeks, range 26.4–34.0), and urinary TCS concentration was measured by isotope dilution TurboFlow–liquid chromatography–tandem mass spectrometry. Multiple linear regression analysis was used to examine associations between prenatal TCS exposure and measures of size at birth (birth weight, length, head and abdominal circumference) and AGD at 3 months of age (median 3.3 months, range 2.3–6.7 months), controlling for potential confounders. Results: Newborn boys in the highest quartile of prenatal TCS exposure had a 0.7-cm [95% confidence interval (CI): –1.2, –0.1, p = 0.01] smaller head circumference than boys in the lowest quartile. Additionally in boys, inverse associations of borderline statistical significance were observed between prenatal TCS exposure and abdominal circumference at birth and AGD at 3 months of age (p-values < 0.10). Prenatal TCS exposure was not significantly associated with any of the outcomes in girls. However, AGD was measured in fewer girls, and we observed no significant interactions between a child’s sex and prenatal TCS exposure in anthropometric measures at birth. Conclusion: Prenatal TCS exposure was associated with reduced head and abdominal circumference at birth and with reduced AGD at 3 months of age in boys, although the last two findings were statistically nonsignificant. These findings require replication but are

  19. Bioaccumulation of triclosan and triclocarban in plants grown in soils amended with municipal dewatered biosolids.

    Science.gov (United States)

    Prosser, Ryan S; Lissemore, Linda; Topp, Edward; Sibley, Paul K

    2014-05-01

    Biosolids generally contain the microbiocidal agents triclosan (TCS) and triclocarban (TCC) that are persistent during wastewater treatment and sorp to organic material. The present study investigated the concentration of TCS in tissues of radish, carrot, and soybean grown in potted soil amended with biosolids. Highest mean concentrations of TCS in radish, carrot, and soybean root tissue midway through the life cycle were 24.8 ng/g, 49.8 ng/g, and 48.1 ng/g dry weight, respectively; by the conclusion of the test, however, concentrations had declined to 2.1 ng/g, 5.5 ng/g, and 8.4 ng/g dry weight, respectively. Highest mean concentrations of TCS in radish and carrot shoot tissue were 33.7 and 18.3 ng/g dry weight at days 19 and 45, respectively, but had declined to 13.7 ng/g and 5.5 ng/g dry weight at days 34 and 69, respectively. Concentration of TCS in all samples of soybean seeds was below method detection limit (i.e., 2.8 ng/g dry wt). The present study also examined the concentration of TCS and TCC in edible portions of green pepper, carrot, cucumber, tomato, radish, and lettuce plants grown in a field amended with biosolids. Triclosan was detected only in cucumber and radish up to 5.2 ng/g dry weight. Triclocarban was detected in carrot, green pepper, tomato, and cucumber up to 5.7 ng/g dry weight. On the basis of the present study and other studies, we estimate that vegetable consumption represents less than 0.5% of the acceptable daily intake of TCS and TCC. These results demonstrate that, if best management practices for land application of biosolids in Ontario are followed, the concentration of TCS and TCC in edible portions of plants represents a negligible exposure pathway to humans.

  20. The bactericidal effect of a Genius (R) Nd : YAG laser

    NARCIS (Netherlands)

    Kranendonk, A.A.; Reijden, W.A. van der; Winkelhoff, A.J. van; Weijden, G.A. van der

    2010-01-01

    PURPOSE: To evaluate the 'in vitro' bactericidal effect of the Nd:YAG laser (Genius, MØlsgaard Dental, Copenhagen, Denmark) on six periodontal pathogens. METHODS: Suspensions of six different periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedi

  1. The bactericidal effect of a Genius Nd: YAG laser

    NARCIS (Netherlands)

    Kranendonk, A.A.; van der Reijden, W.A.; van Winkelhoff, A.J.; van der Weijden, G.A.

    2010-01-01

    Purpose: To evaluate the ‘in vitro’ bactericidal effect of the Nd:YAG laser (Genius, MØlsgaard Dental, Copenhagen, Denmark) on six periodontal pathogens. Methods: Suspensions of six different periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedi

  2. The bactericidal effect of a Genius (R) Nd : YAG laser

    NARCIS (Netherlands)

    Kranendonk, A.A.; Reijden, W.A. van der; Winkelhoff, A.J. van; Weijden, G.A. van der

    2010-01-01

    PURPOSE: To evaluate the 'in vitro' bactericidal effect of the Nd:YAG laser (Genius, MØlsgaard Dental, Copenhagen, Denmark) on six periodontal pathogens. METHODS: Suspensions of six different periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedi

  3. Sublethal Triclosan Exposure Decreases Susceptibility to Gentamicin and Other Aminoglycosides in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Christensen, Ellen Gerd; Gram, Lone; Kastbjerg, Vicky Gaedt

    2011-01-01

    The human food-borne pathogen Listeria monocytogenes is capable of persisting in food processing plants despite cleaning and sanitation and is likely exposed to sublethal biocide concentrations. This could potentially affect susceptibility of the bacterium to biocides and other antimicrobial agen...... is commonly used in listeriosis treatment. The triclosan-induced resistance is, hence, of great concern. Further investigations are needed to determine the molecular mechanisms underlying the effect of triclosan....

  4. Triclosan Derivatives: Towards Potent Inhibitors of Drug-Sensitive and Drug-Resistant Mycobacterium tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Freundlich, Joel S.; Wang, Feng; Vilchèze, Catherine; Gulten, Gulcin; Langley, Robert; Schiehser, Guy A.; Jacobus, David P.; Jacobs, Jr., William R.; Sacchettini, James C.; (Einstein); (TAM); (Jacobus)

    2009-06-30

    Isoniazid (INH) is a frontline antitubercular drug that inhibits the enoyl acyl carrier protein reductase InhA. Novel inhibitors of InhA that are not cross-resistant to INH represent a significant goal in antitubercular chemotherapy. The design, synthesis, and biological activity of a series of triclosan-based inhibitors is reported, including their promising efficacy against INH-resistant strains of M. tuberculosis. Triclosan has been previously shown to inhibit InhA, an essential enoyl acyl carrier protein reductase involved in mycolic acid biosynthesis, the inhibition of which leads to the lysis of Mycobacterium tuberculosis. Using a structure-based drug design approach, a series of 5-substituted triclosan derivatives was developed. Two groups of derivatives with alkyl and aryl substituents, respectively, were identified with dramatically enhanced potency against purified InhA. The most efficacious inhibitor displayed an IC{sub 50} value of 21 nM, which was 50-fold more potent than triclosan. X-ray crystal structures of InhA in complex with four triclosan derivatives revealed the structural basis for the inhibitory activity. Six selected triclosan derivatives were tested against isoniazid-sensitive and resistant strains of M. tuberculosis. Among those, the best inhibitor had an MIC value of 4.7 {mu}g mL{sup -1} (13 {mu}M), which represents a tenfold improvement over the bacteriocidal activity of triclosan. A subset of these triclosan analogues was more potent than isoniazid against two isoniazid-resistant M. tuberculosis strains, demonstrating the significant potential for structure-based design in the development of next generation antitubercular drugs.

  5. Meta-analysis of biosolid effects on persistence of triclosan and triclocarban in soil.

    Science.gov (United States)

    Fu, Qiuguo; Sanganyado, Edmond; Ye, Qingfu; Gan, Jay

    2016-03-01

    Biosolids are extensively used in agriculture as fertilizers while offering a practical solution for waste disposal. Many pharmaceutical and personal care products (PPCPs), such as triclosan and triclocarban, are enriched in biosolids. Biosolid amendment changes soil physicochemical properties, which may in turn alter the persistence of PPCPs and hence the risk for secondary contamination such as plant uptake. To delineate the effect of biosolids on PPCPs persistence, triclosan and triclocarban were used as model compounds in this study and their sorption (Kd) and persistence (t1/2) were determined in different soils before and after biosolid amendment. Biosolids consistently increased sorption of triclosan and triclocarban in soil. The Kd of triclosan increased by 3.9-21 times following amendment of a sandy loam soil with biosolids at 2-10%. The persistence of both compounds was prolonged, with t1/2 of triclosan increasing from 10 d in the unamended soil to 63 d after biosolid amendment at 10%. The relationship between t1/2 and Kd was further examined through a meta-analysis using data from this study and all relevant published studies. A significant linear relationship between t1/2 and Kd was observed for triclosan (r(2) = 0.69, p triclosan was prolonged by 7.5 d, while t1/2 of triclocarban was extended by 4.7 d. Therefore, biosolid amendment greatly enhances persistence of triclosan and triclocarban, likely due to enhanced sorption or decreased chemical bioavailability. This finding highlights the importance to consider the effect of biosolids when evaluating the environmental risks of these and other biosolid-borne PPCPs.

  6. Triclosan-coated sutures and sternal wound infections: a prospective randomized clinical trial.

    Science.gov (United States)

    Steingrimsson, S; Thimour-Bergström, L; Roman-Emanuel, C; Scherstén, H; Friberg, Ö; Gudbjartsson, T; Jeppsson, A

    2015-12-01

    Surgical site infection is a common complication following cardiac surgery. Triclosan-coated sutures have been shown to reduce the rate of infections in various surgical wounds, including wounds after vein harvesting in coronary artery bypass grafting patients. Our purpose was to compare the rate of infections in sternotomy wounds closed with triclosan-coated or conventional sutures. A total of 357 patients that underwent coronary artery bypass grafting were included in a prospective randomized double-blind single-center study. The patients were randomized to closure of the sternal wound with either triclosan-coated sutures (Vicryl Plus and Monocryl Plus, Ethicon, Inc., Somerville, NJ, USA) (n = 179) or identical sutures without triclosan (n = 178). Patients were followed up after 30 days (clinical visit) and 60 days (telephone interview). The primary endpoint was the prevalence of sternal wound infection according to the Centers for Disease Control and Prevention (CDC) criteria. The demographics in both groups were comparable, including age, gender, body mass index, and rate of diabetes and smoking. Sternal wound infection was diagnosed in 43 patients; 23 (12.8%) sutured with triclosan-coated sutures compared to 20 (11.2%) sutured without triclosan (p = 0.640). Most infections were superficial (n = 36, 10.1%), while 7 (2.0%) were deep sternal wound infections. There were 16 positive cultures in the triclosan group and 17 in the non-coated suture group (p = 0.842). The most commonly identified main pathogens were Staphylococcus aureus (45.4%) and coagulase-negative staphylococci (36.4%). Skin closure with triclosan-coated sutures did not reduce the rate of sternal wound infection after coronary artery bypass grafting. (clinicaltrials.gov: NCT01212315).

  7. [Bactericidal activity of colloidal silver against grampositive and gramnegative bacteria].

    Science.gov (United States)

    Afonina, I A; Kraeva, L A; Tseneva, G Ia

    2010-01-01

    It was shown that colloidal silver solution prepared in cooperation with the A. F. Ioffe Physical Technical Institute of the Russian Academy of Sciences, had significant bactericidal activity. Stable bactericidal effect on gramnegative microorganisms was observed after their 2-hour exposition in the solution of colloidal silver at a concentration of 10 ppm. Grampositive capsule-forming microorganisms were less susceptible to the colloidal silver solution: their death was observed after the 4-hour exposition in the solution.

  8. Triclosan Resistance in a Bacterial Fish Pathogen, Aeromonas salmonicida subsp. salmonicida, is Mediated by an Enoyl Reductase, FabV.

    Science.gov (United States)

    Khan, Raees; Lee, Myung Hwan; Joo, Hae-Jin; Jung, Yong-Hoon; Ahmad, Shabir; Choi, Jin-Hee; Lee, Seon-Woo

    2015-04-01

    Triclosan, the widely used biocide, specifically targets enoyl-acyl carrier protein reductase (ENR) in the bacterial fatty acid synthesis system. Although the fish pathogen Aeromonas salmonicida subsp. salmonicida exhibits triclosan resistance, the nature of this resistance has not been elucidated. Here, we aimed to characterize the triclosan resistance of A. salmonicida subsp. salmonicida causing furunculosis. The fosmid library of triclosan-resistant A. salmonicida subsp. salmonicida was constructed to select a fosmid clone showing triclosan resistance. With the fosmid clone showing triclosan resistance, a subsequent secondary library search resulted in the selection of subclone pTSR-1. DNA sequence analysis of pTSR-1 revealed the presence of a chromosomal-borne fabV-encoding ENR homolog. The ENR of A. salmonicida (FabVas) exhibited significant homology with previously known FabV, including the catalytic domain YX(8)K. fabVas introduction into E. coli dramatically increased its resistance to triclosan. Heterologous expression of FabVas might functionally replace the triclosan-sensitive FabI in vivo to confer E. coli with triclosan resistance. A genome-wide search for fabVas homologs revealed the presence of an additional fabV gene (fabVas2) paralog in A. salmonicida strains and the fabVas orthologs from other gram-negative fish pathogens. Both of the potential FabV ENRs expressed similarly with or without triclosan supplement. This is the first report about the presence of two potential FabV ENRs in a single pathogenic bacterium. Our result suggests that triclosan-resistant ENRs are widely distributed in various bacteria in nature, and the wide use of this biocide can spread these triclosan-tolerant ENRs among fish pathogens and other pathogenic bacteria.

  9. Triclosan exposure reduces thyroxine levels in pregnant and lactating rat dams and in directly exposed offspring.

    Science.gov (United States)

    Axelstad, Marta; Boberg, Julie; Vinggaard, Anne Marie; Christiansen, Sofie; Hass, Ulla

    2013-09-01

    Thyroid disrupting chemicals can potentially disrupt brain development. Two studies investigating the effect of the antibacterial compound triclosan on thyroxine (T₄) levels in rats are reported. In the first, Wistar rat dams were gavaged with 75, 150 or 300 mg triclosan/kg bw/day throughout gestation and lactation. Total T₄ serum levels were measured in dams and offspring, and all doses of triclosan significantly lowered T₄ in dams, but no significant effects on T₄ levels were seen in the offspring at the end of the lactation period. Since this lack of effect could be due to minimal exposure through maternal milk, a second study using direct per oral pup exposure from postnatal day 3-16 to 50 or 150 mg triclosan/kg bw/day was performed. This exposure pointed to significant T₄ reductions in 16 day old offspring in both dose groups. These results corroborate previous studies showing that in rats lactational transfer of triclosan seems limited. Since an optimal study design for testing potential developmental neurotoxicants in rats, should include exposure during both the pre- and postnatal periods of brain development, we suggest that in the case of triclosan, direct dosing of pups may be the best way to obtain that goal.

  10. Investigations of immunotoxicity and allergic potential induced by topical application of triclosan in mice.

    Science.gov (United States)

    Anderson, Stacey E; Meade, B Jean; Long, Carrie M; Lukomska, Ewa; Marshall, Nikki B

    2016-01-01

    Triclosan is an antimicrobial chemical commonly used occupationally and by the general public. Using select immune function assays, the purpose of these studies was to evaluate the immunotoxicity of triclosan following dermal exposure using a murine model. Triclosan was not identified to be a sensitizer in the murine local lymph node assay (LLNA) when tested at concentrations ranging from 0.75-3.0%. Following a 28-day exposure, triclosan produced a significant increase in liver weight at concentrations of ≥ 1.5%. Exposure to the high dose (3.0%) also produced a significant increase in spleen weights and number of platelets. The absolute number of B-cells, T-cells, dendritic cells and NK cells were significantly increased in the skin draining lymph node, but not the spleen. An increase in the frequency of dendritic cells was also observed in the lymph node following exposure to 3.0% triclosan. The IgM antibody response to sheep red blood cells (SRBC) was significantly increased at 0.75% - but not at the higher concentrations - in the spleen and serum. These results demonstrate that dermal exposure to triclosan induces stimulation of the immune system in a murine model and raise concerns about potential human exposure.

  11. Electro-Fenton degradation of antimicrobials triclosan and triclocarban

    Energy Technology Data Exchange (ETDEWEB)

    Sires, Ignasi [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Oturan, Nihal [Universite de Marne la Vallee, Laboratoire des Geomateriaux et Geologie de l' Ingenieur, 5 Boulevard Descartes, Champs-sur-Marne, 77454 Marne-la-Vallee Cedex 2 (France); Oturan, Mehmet A. [Universite de Marne la Vallee, Laboratoire des Geomateriaux et Geologie de l' Ingenieur, 5 Boulevard Descartes, Champs-sur-Marne, 77454 Marne-la-Vallee Cedex 2 (France); Rodriguez, Rosa Maria [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Garrido, Jose Antonio [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Brillas, Enric [Laboratori d' Electroquimica dels Materials i del Medi Ambient, Departament de Quimica Fisica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain)]. E-mail: brillas@ub.edu

    2007-05-05

    The antimicrobials triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) and triclocarban (N-(4-chlorophenyl)-N'-(3,4-dichlorophenyl)urea) have been degraded by four electro-Fenton systems using undivided electrolytic cells with a Pt or boron-doped diamond (BDD) anode and a carbon felt or O{sub 2} diffusion cathode. The main oxidant is hydroxyl radical ({center_dot}OH) produced both on the anode surface from water oxidation and in the medium by Fenton's reaction, which takes place between electrogenerated H{sub 2}O{sub 2} and Fe{sup 2+} coming from cathodic reduction of O{sub 2} and Fe{sup 3+}, respectively. Triclosan from saturated aqueous solutions of pH 3.0 is completely removed in all cells, decreasing its decay rate in the order: Pt/carbon felt > BDD/carbon felt > Pt/O{sub 2} diffusion > BDD/O{sub 2} diffusion, in agreement with their {center_dot}OH generation ability from Fenton's reaction. Glyoxylic, maleic and oxalic acids are identified as aliphatic intermediates. Complexes between oxalic acid and iron ions persist largely in solution, although Fe{sup 2+}-oxalato complexes are mineralized by {center_dot}OH in the medium and Fe{sup 3+}-oxalato complexes are destroyed by {center_dot}OH on BDD. Analogous treatments of more concentrated triclosan solutions using a 20:80 (v/v) acetonitrile/water mixture as solvent evidence the role of hydroxyl radicals along the degradation. In this hydroorganic medium hydroxylated derivatives such as 2,4-dichlorophenol, 4-chlorocatechol, chlorohydroquinone and chloro-p-benzoquinone, and carboxylic acids such as maleic, oxalic, formic and acetic acids are detected as products. Complete destruction of iron-oxalato complexes and released Cl{sup -} ion involves some oxidizing species coming from parallel acetonitrile oxidation. The same electro-Fenton systems also yield the overall removal of triclocarban in acetonitrile/water mixtures, giving rise to urea, hydroquinone, chlorohydroquinone, 1-chloro-4

  12. Two major medicinal honeys have different mechanisms of bactericidal activity.

    Directory of Open Access Journals (Sweden)

    Paulus H S Kwakman

    Full Text Available Honey is increasingly valued for its antibacterial activity, but knowledge regarding the mechanism of action is still incomplete. We assessed the bactericidal activity and mechanism of action of Revamil® source (RS honey and manuka honey, the sources of two major medical-grade honeys. RS honey killed Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa within 2 hours, whereas manuka honey had such rapid activity only against B. subtilis. After 24 hours of incubation, both honeys killed all tested bacteria, including methicillin-resistant Staphylococcus aureus, but manuka honey retained activity up to higher dilutions than RS honey. Bee defensin-1 and H₂O₂ were the major factors involved in rapid bactericidal activity of RS honey. These factors were absent in manuka honey, but this honey contained 44-fold higher concentrations of methylglyoxal than RS honey. Methylglyoxal was a major bactericidal factor in manuka honey, but after neutralization of this compound manuka honey retained bactericidal activity due to several unknown factors. RS and manuka honey have highly distinct compositions of bactericidal factors, resulting in large differences in bactericidal activity.

  13. Physicochemical properties of bactericidal plasma-treated water

    Science.gov (United States)

    Ikawa, Satoshi; Tani, Atsushi; Nakashima, Yoichi; Kitano, Katsuhisa

    2016-10-01

    Plasma-treated water (PTW), i.e. distilled water (DW) exposed to low-temperature atmospheric pressure helium plasma, exhibited strong bactericidal activity against Escherichia coli in suspension even within a few minutes of preparation. This effect was enhanced under acidic conditions. The bactericidal activity of PTW was attenuated according to first-order kinetics and the half-life was highly temperature dependent. The electron spin resonance (ESR) signal of an adduct of the superoxide anion radical (\\text{O}2-\\bullet ) was detected in an aqueous solution using a spin-trapping reagent mixed with PTW, and adding superoxide dismutase to the PTW resulted in a loss of the bactericidal activity and weakening of the ESR adduct signal of \\text{O}2-\\bullet in the spin-trapping. These results suggest that \\text{O}2-\\bullet plays an important role in imparting bactericidal activity to PTW. Moreover, molecular nitrogen was required both in the ambient gas and in the DW used to prepare the PTW. We, therefore, suggest that the reactive molecule in PTW with bactericidal effects is not a free reactive oxygen species but nitrogen atom(s)-containing molecules that release \\text{O}2-\\bullet , such as peroxynitrous acid (ONOOH) or peroxynitric acid (O2NOOH). Considering the activation energy for degradation of these species, we conclude that peroxynitric acid stored in PTW induces the bactericidal effect.

  14. Triclosan demonstrates synergic effect with amphotericin B and fluconazole and induces apoptosis-like cell death in Cryptococcus neoformans

    Directory of Open Access Journals (Sweden)

    Elaheh eMovahed

    2016-03-01

    Full Text Available Objectives: Cryptococcus neoformans is an opportunistic fungus that causes fatal meningoencephalitis especially in AIDS patients. There is an increasing need for discovery of new anti-cryptococcal drugs due to emergence of resistance cases in recent years. In this study, we aim to elucidate the antifungal effect of triclosan against C. neoformans.Methods: Minimal inhibitory concentration (MIC of triclosan in different C. neoformans strains was first examined. The in vitro interactions between triclosan and two standard anti-fungal drugs (amphotericin B and fluconazole were further evaluated by microdilution checkerboard assay. Mechanism of triclosan fungicidal activity was then investigated by viewing the cell morphology under transmission electron microscope.Results: We reported that triclosan potently inhibited the growth of C. neoformans. A combination of triclosan with amphotericin B or with fluconazole enhanced their fungicidal effects. Triclosan-treated C. neoformans displayed characteristics such as nuclear chromatin condensation, extensive intracellular vacuolation and mitochondrial swelling, indicating that triclosan triggered apoptosis-like cell death.Conclusion: In summary, our report suggests triclosan as an independent drug or synergent for C. neoformans treatment.

  15. Toxic Assessment of Triclosan and Triclocarban on Artemia salina.

    Science.gov (United States)

    Xu, Xiaolu; Lu, Yin; Zhang, Deyong; Wang, Yinyin; Zhou, Xianshan; Xu, Huiying; Mei, Yu

    2015-12-01

    In this study, we investigated the possible acute toxic and genotoxic effects of triclosan (TCS) and triclocarban (TCC) on Artemia salina. Genotoxicity was evaluated using single-cell gel electrophoresis and apoptotic frequency assays (Annexin V-FITC/PI assay). Acute toxicity test results showed that TCC (LC50-24 h = 17.8 µg/L) was more toxic than TCS (LC50-24 h = 171.1 µg/L). Significant increases in both genotoxic biomarkers were observed at 24 h after initial exposure, indicating that these two chemicals are potentially dangerous for this aquatic biological model. Although further studies are required, a comparison of data both in vitro and in vivo allowed us to suggest possible mechanisms of action for TCS and TCC in this sentinel organism.

  16. Resilience and recovery: The effect of triclosan exposure timing during development, on the structure and function of river biofilm communities

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, J.R., E-mail: john.lawrence@ec.gc.ca [Environment Canada, 11 Innovation Blvd., Saskatoon, SK S7N 3H5 (Canada); Topp, E. [Agriculture and Agri-Food Canada, London, ON (Canada); Waiser, M.J.; Tumber, V.; Roy, J.; Swerhone, G.D.W. [Environment Canada, 11 Innovation Blvd., Saskatoon, SK S7N 3H5 (Canada); Leavitt, P. [University of Regina, Regina, SK (Canada); Paule, A. [Global Institute for Water Security, University of Saskatchewan, Saskatoon, SK (Canada); Korber, D.R. [Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK (Canada)

    2015-04-15

    Highlights: • Triclosan negatively affected structure and metabolism of biofilms under all exposure conditions. • Biofilm age, timing and exposure regime alter the effects of triclosan. • Regardless of exposure regime algae and cyanobacteria were the most affected. • Although recovery was evident no community regained the reference condition. • Initial recruitment may be significant in determining community recovery. - Abstract: Triclosan (TCS) is a ubiquitous antibacterial agent found in soaps, scrubs, and consumer products. There is limited information on hazardous effects of TCS in the environment. Here, rotating annular reactors were used to cultivate river biofilm communities exposed to 1.8 μg l{sup −1} TCS with the timing and duration of exposure and recovery during development varied. Two major treatment regimens were employed: (i) biofilm development for 2, 4 or 6 weeks prior to TCS exposure and (ii) exposure of biofilms to TCS for 2, 4 or 6 weeks followed by recovery. Biofilms not exposed to TCS were used as a reference condition. Communities cultivated without and then exposed to TCS all exhibited reductions in algal biomass and significant (p < 0.05) reductions in cyanobacterial biomass. No significant effects were observed on bacterial biomass. CLSM imaging of biofilms at 8 weeks revealed unique endpoints in terms of community architecture. Community composition was altered by any exposure to TCS, as indicated by significant shifts in denaturing gradient gel electrophoresis fingerprints and exopolymer composition relative to the reference. Bacterial, algal and cyanobacterial components initially exposed to TCS were significantly different from those TCS-free at time zero. Pigment analyses suggested that significant changes in composition of algal and cyanobacterial populations occurred with TCS exposure. Bacterial thymidine incorporation rates were reduced by TCS exposure and carbon utilization spectra shifted in terms substrate metabolism

  17. Rapid antibacterial activity of 2 novel hand soaps: evaluation of the risk of development of bacterial resistance to the antibacterial agents.

    Science.gov (United States)

    Geraldo, Ingrid M; Gilman, Allan; Shintre, Milind S; Modak, Shanta M

    2008-08-01

    To evaluate the antimicrobial efficacy of and risk of organisms developing resistance to 2 novel hand soaps: (1) a soap containing triclosan, polyhexamethylene biguanide, and benzethonium chloride added to a soap base (TPB soap); and (2) a soap containing farnesol, polyhexamethylene biguanide, and benzethonium chloride added to a soap base (FPB soap). Tests also included soaps containing only triclosan. The risk of emergence of resistant bacterial mutants was investigated by determining the susceptibility changes after repeated exposure of bacteria to the drugs and soaps in vitro. The effectiveness of the soaps was evaluated using an in vitro tube dilution method, a volunteer method (the ASTM standard), and 2 pig skin methods. The minimum inhibitory concentration and minimum bactericidal concentration of triclosan against Staphylococcus aureus increased 8- to 62.5-fold, whereas those of TPB and FPB (both alone and in soap) were unchanged. In vitro, TPB and FPB soaps produced higher log(10) reductions in colony-forming units of all tested organisms (4.95-8.58) than did soaps containing triclosan alone (0.29-4.86). In the test using the pig skin and volunteer methods, TPB soap produced a higher log(10) reduction in colony-forming units (3.1-3.3) than did the soap containing triclosan alone (2.6-2.8). The results indicate that TPB and FPB soaps may provide superior rapid and broad-spectrum efficacy with a lower risk of organisms developing resistance than do soaps containing triclosan alone. Pig skin methods may be used to predict the efficacy of antibacterial soaps in the rapid disinfection of contaminated hands. Hand washing with TPB and FPB soaps by healthcare workers and the general population may reduce the transmission of pathogens, with a lower risk of promoting the emergence of resistant organisms.

  18. Triclosan exposure alters postembryonic development in a Pacific tree frog (Pseudacris regilla) Amphibian Metamorphosis Assay (TREEMA)

    Energy Technology Data Exchange (ETDEWEB)

    Marlatt, Vicki L. [Nautilus Environmental, 8864 Commerce Court, Burnaby, B.C. V5A 4N7 (Canada); Veldhoen, Nik [Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055 Stn CSC, Victoria, B.C. V8W 3P6 (Canada); Lo, Bonnie P. [Nautilus Environmental, 8864 Commerce Court, Burnaby, B.C. V5A 4N7 (Canada); Bakker, Dannika; Rehaume, Vicki; Vallee, Kurtis [Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055 Stn CSC, Victoria, B.C. V8W 3P6 (Canada); Haberl, Maxine; Shang, Dayue; Aggelen, Graham C. van; Skirrow, Rachel C. [Pacific and Yukon Laboratory for Environmental Testing, Emergencies Operational Analytical Laboratories and Research Support Division, Environment Canada, 2645 Dollarton Highway, North Vancouver, B.C. V7H 1B1 (Canada); Elphick, James R. [Nautilus Environmental, 8864 Commerce Court, Burnaby, B.C. V5A 4N7 (Canada); Helbing, Caren C., E-mail: chelbing@uvic.ca [Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055 Stn CSC, Victoria, B.C. V8W 3P6 (Canada)

    2013-01-15

    The Amphibian Metamorphosis Assay (AMA), developed for Xenopus laevis, is designed to identify chemicals that disrupt thyroid hormone (TH)-mediated biological processes. We adapted the AMA for use on an ecologically-relevant North American species, the Pacific tree frog (Pseudacris regilla), and applied molecular endpoints to evaluate the effects of the antibacterial agent, triclosan (TCS). Premetamorphic (Gosner stage 26-28) tadpoles were immersed for 21 days in solvent control, 1.5 {mu}g/L thyroxine (T{sub 4}), 0.3, 3 and 30 {mu}g/L (nominal) TCS, or combined T{sub 4}/TCS treatments. Exposure effects were scored by morphometric (developmental stage, wet weight, and body, snout-vent and hindlimb lengths) and molecular (mRNA abundance using quantitative real time polymerase chain reaction) criteria. T{sub 4} treatment alone accelerated development concomitant with altered levels of TH receptors {alpha} and {beta}, proliferating cell nuclear antigen, and gelatinase B mRNAs in the brain and tail. We observed TCS-induced perturbations in all of the molecular and morphological endpoints indicating that TCS exposure disrupts coordination of postembryonic tadpole development. Clear alterations in molecular endpoints were evident at day 2 whereas the earliest morphological effects appeared at day 4 and were most evident at day 21. Although TCS alone (3 and 30 {mu}g/L) was protective against tadpole mortality, this protection was lost in the presence of T{sub 4}. The Pacific tree frog is the most sensitive species examined to date displaying disruption of TH-mediated development by a common antimicrobial agent.

  19. Bactericidal activity of ethanolic extracts of propolis against Staphylococcus aureus isolated from mastitic cows.

    Science.gov (United States)

    Santana, Henrique Freitas; Barbosa, Ana Andréa Teixeira; Ferreira, Sukarno Olavo; Mantovani, Hilário Cuquetto

    2012-02-01

    Staphylococcus aureus is an important pathogen for both humans and animals, and it has been an ubiquitous etiological agent of bovine mastitis in dairy farms worldwide. Elimination of S. aureus with classic antibiotics is difficult, and the current study aimed to evaluate the efficacy of ethanolic extracts of propolis (EEP) against S. aureus cultivated in complex media or milk. EEP (0-0.5 mg ml(-1)) decreased growth of S. aureus in BHI media and 1 mg ml(-1) was bactericidal against washed cell suspensions (10(7) CFU ml(-1)). Propolis extracts also killed S. aureus cells resuspended in milk, but the bactericidal dose was at least 20-fold greater. Cultures that were transferred for at least 60 generations with sub-lethal doses of propolis did not change much their sensibility to EEP. Atomic force microscopy images revealed changes in morphology and cell size of S. aureus cells exposed to EEP (0.5 mg ml(-1)). Our results indicate that propolis extracts might be effective against mastitis-causing S. aureus strains in vivo, but milk constituents affect the inhibitory activity of propolis. Considering that propolis-resistance appears to be a phenotype not easily selected, the use of EEP combined or not with other antimicrobial agents might be useful for mastitis control in vivo.

  20. Synthesis and evaluation of bactericidal properties of CuO nanoparticles against Aeromonas hydrophila

    Directory of Open Access Journals (Sweden)

    Sayedeh Fatemeh Shaffiey

    2014-04-01

    Full Text Available   Objective(s: CuO is one of the most important transition metal oxides due to its captivating properties. It is used in various technological applications such as high critical temperature superconductors, gas sensors, in photoconductive applications, and so on. Recently, it has been used as an antimicrobial agent against various bacterial species.   Materials and Methods: Here, we synthesized CuO nanoparticles (NPs and explored the antibacterial activity of CuO NPs preparation. Results: Single crystalline nanoparticles of copper oxide having almost uniform particle size of 5-6 nm has been synthesized by a facile and versatile route. XRD spectra confirmed the formation of single phase CuO NPs. Transmission electron microscopy results corroborate well with XRD results. The technique employed is free from toxic solvents, organics and amines, is based on a simple reaction of copper sulfate and de-ionized water (DI, and their bactericidal effects against of Aeromonas hydrophila ATCC 7966T bacteria were investigated. Minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC with liquid culture for all of the Aeromonas hydrophila culture Medias was done. Conclusion: Present study confirms that Copper oxide nanoparticles have great promise as antimicrobial agent against Aeromonas hydrophila

  1. Retrospective monitoring of triclosan and methyl-triclosan in fish. Results from the German Environmental Specimen Bank

    Energy Technology Data Exchange (ETDEWEB)

    Boehmer, W.; Ruedel, H.; Wenzel, A. [Fraunhofer IME, Schmallenberg (Germany); Schroeter-Kermani, C. [Umweltbundesamt, Berlin (Germany)

    2004-09-15

    During the last years there were several reports on the appearance of the biocides triclosan (TCS; 5- chloro-2-(2,4-dichlorophenoxy)phenol; CAS No. 3380-34-5) and chlorophene (CP; 4-Chloro-2- (phenylmethyl)phenol; CAS No. 120-32-1) in the environment. TCS is used in numerous personal care products like toothpaste and soaps, but also in textiles and shoes. The current annual consumption in Germany is estimated to be 40 t (0.5 g per capita and year). During use large amounts of TCS and CP are disposed into waste water. Modern waste water treatment plants (WWTP) eliminate approximately 95 % of TCS, mainly by biodegradation and adsorption to sludge. It was observed that during waste water treatment methyl-triclosan (MTCS; 5-chloro-2-(2,4-dichlorophenoxy)anisole; CAS No. 4640-01-1) is formed, probably due to microbial methylation. In a WWTP effluent up to 1 % MTCS in relation to TCS was detected. The environmental half-life of TCS is assumed to be low, mainly because it is susceptible to photodegradation at environmental pH levels while MTCS is stable under these conditions. The logPow values of 4.7 for TCS and 5.2 for MTCS (estimated with KowWin Vers. 1,67, respectively) indicate potential for bioaccumulation. Based in order to investigate the exposure of aquatic organisms towards CP, TCS and MTCS in Germany a retrospective monitoring of breams (Abramis brama) from representative rivers was initiated. Samples from the period 1994 to 2003 were taken from the archive of the German Environmental Specimen Bank (ESB) to evaluate temporal changes and regional differences of the occurrence of the target compounds.

  2. A comparison between the oxidation with laccase and horseradish peroxidase for triclosan conversion.

    Science.gov (United States)

    Melo, C F; Dezotti, M; Marques, M R C

    2016-01-01

    Triclosan is a broad-spectrum biocide used in personal-care products that is suspected to be linked to the emergence of antibiotic-resistant bacteria. In the present work, the enzymes horseradish peroxidase and laccase from Trametes versicolor were evaluated for the conversion of triclosan in an aqueous matrix. The removal of antibacterial activity by the enzymatic processes was evaluated by an assay based on the growth inhibition of Escherichia coli K12. The horseradish peroxidase (HRP) process appears more advantageous than the laccase process in removing triclosan from an aqueous matrix, considering the reaction parameters pH, temperature, catalytic efficiency, and enzyme concentration. The highest conversion of triclosan catalysed by laccase was observed at pH 5.0, that is, lower than the typical pH range (6.5-7.5) of sewage treatment plants' effluents. The efficiency of laccase process was much more impacted by variations in the temperature in the range of 10-40°C. Kinetic studies showed that triclosan is a substrate more specific for HRP than for laccase. The protein content for the HRP-catalysed process was 14 times lower than that for the laccase process. Decay kinetics suggest that reaction mechanisms depend on enzyme concentration and its concentration. Both processes were able to reduce the antibacterial activity, and the residual activity of the treated solution is probably due to non-converted triclosan and not due to the reaction products. The laccase-catalysed conversion of triclosan in an environmental relevant concentration required a higher amount of enzyme than that required in the HRP process.

  3. Spectroscopic Determination of Triclosan Concentration in a Series of Antibacterial Soaps: A First-Year Undergraduate Laboratory Experiment

    Science.gov (United States)

    Wyllie, Graeme R. A.

    2015-01-01

    The antibacterial chemical triclosan is a common component in personal care products but recently the subject of many reports concerning environmental toxicity and health impacts. Although triclosan concentration in a soap can be determined simply via high-performance liquid chromatography, this is a technique not routinely available in the…

  4. Accumulation of triclosan from diet and its neuroendocrine effects in Atlantic croaker (Micropogonias undulatus) under two temperature Regimes.

    Science.gov (United States)

    Hedrick-Hopper, Tiffany L; Koster, Lauren P; Diamond, Sandra L

    2015-12-01

    Rising water temperatures due to climate change may increase the uptake and effects of triclosan in aquatic organisms. Our objectives were to investigate the accumulation of dietary triclosan and its neuroendocrine effects in Atlantic croaker, an estuarine fish, under two temperatures and during depuration. A pilot study was used to select a dietary exposure of 50 mg/kg. For 10 days, fish were exposed to one of four diet/temperature treatments (n = 16/treatment): normal diet at 26 °C and 29 °C and triclosan-treated diet at 26 °C and 29 °C. Fish exposed to triclosan at 26 °C accumulated 2.6 mg/kg wet weight on average versus 5.6 mg/kg wet weight at 29 °C. Triclosan exposure significantly impacted reflexes, resulting in the loss of the dorsal fin reflex (DS) in 53% of fish, while temperature and triclosan-temperature interactions were not significant. Triclosan body burden did not significantly predict DS loss. There were no significant differences in thyroid hormone levels among groups. Triclosan-treated fish at 26 °C were fed untreated pellets for 5 additional weeks. Two fish lost the DS during the first depuration week, and no affected fish recovered the reflex. These results have important implications for fish and their predators, as the DS may be important for swimming performance and social patterning.

  5. Toxicity of triclosan, penconazole and metalaxyl on Caulobacter crescentus and a freshwater microbial community as assessed by flow cytometry.

    Science.gov (United States)

    Johnson, David R; Czechowska, Kamila; Chèvre, Nathalie; van der Meer, Jan Roelof

    2009-07-01

    Biocides are widely used for domestic hygiene, agricultural and industrial applications. Their widespread use has resulted in their introduction into the environment and raised concerns about potential deleterious effects on aquatic ecosystems. In this study, the toxicity of the biocides triclosan, penconazole and metalaxyl were evaluated with the freshwater bacterium Caulobacter crescentus and with a freshwater microbial community using a combination of single- and double-stain flow cytometric assays. Growth of C.  crescentus and the freshwater community were repressed by triclosan but not by penconazole or metalaxyl at concentrations up to 250 μM. The repressive effect of triclosan was dependent on culture conditions. Caulobacter crescentus was more sensitive to triclosan when grown with high glucose at high cell density than when grown directly in sterilized lake water at low cell density. This suggests that the use of conventional growth conditions may overestimate biocide toxicity. Additional experiments showed that the freshwater community was more sensitive to triclosan than C.  crescentus, with 10 nM of triclosan being sufficient to repress growth and change the phylogenetic composition of the community. These results demonstrate that isolate-based assays may underestimate biocide toxicity and highlight the importance of assessing toxicity directly on natural microbial communities. Because 10 nM of triclosan is within the range of concentrations observed in freshwater systems, these results also raise concerns about the risk of introducing triclosan into the environment.

  6. Relationship between urinary triclosan and paraben concentrations and serum thyroid measures in NHANES 2007-2008.

    Science.gov (United States)

    Koeppe, Erika S; Ferguson, Kelly K; Colacino, Justin A; Meeker, John D

    2013-02-15

    Triclosan and parabens are broad spectrum antimicrobials used in a range of consumer products. In vitro and animal studies have suggested the potential for these compounds to disrupt thyroid function, though studies in humans have been limited. The objective of the study was to assess the relationship of urinary concentrations of triclosan and parabens with serum thyroid measures in a large, representative sample of the US population. We conducted an exploratory, cross-sectional analysis of data on urinary biomarkers of triclosan and paraben exposure and serum thyroid measures obtained from 1831 subjects (ages≥12 years) as part of the 2007-2008 National Health and Nutrition Examination Survey (NHANES). We found evidence of some inverse associations between parabens and circulating thyroid hormone levels in adults, with the strongest and most consistent associations among females. We also observed a positive association between triclosan and total triiodothyonine (T3) concentrations in adolescents. These results, in accordance with the in vitro and animal literature, suggest that paraben, and potentially triclosan, exposures may be associated with altered thyroid hormone levels in humans. Further research is needed for confirmation and to determine the potential clinical and public health significance of these findings.

  7. Relationship between Urinary Triclosan and Paraben Concentrations and Serum Thyroid Measures in NHANES 2007–2008

    Science.gov (United States)

    Koeppe, Erika S.; Ferguson, Kelly K.; Colacino, Justin A.; Meeker, John D.

    2013-01-01

    Triclosan and parabens are broad spectrum antimicrobials used in a range of consumer products. In vitro and animal studies have suggested the potential for these compounds to disrupt thyroid function, though studies in humans have been limited. The objective of the study was to assess the relationship of urinary concentrations of triclosan and parabens with serum thyroid measures in a large, representative sample of the US population. We conducted an exploratory, cross-sectional analysis of data on urinary biomarkers of triclosan and paraben exposure and serum thyroid measures obtained from 1,831 subjects (ages ≥12 years) as part of the 2007–2008 National Health and Nutrition Examination Survey (NHANES). We found evidence of some inverse associations between parabens and circulating thyroid hormone levels in adults, with the strongest and most consistent associations among females. We also observed a positive association between triclosan and total triiodothyonine (T3) concentrations in adolescents. These results, in accordance with the in vitro and animal literature, suggest that paraben, and potentially triclosan, exposures may be associated with altered thyroid hormone levels in humans. Further research is needed for confirmation and to determine the potential clinical significance of these findings. PMID:23340023

  8. Toxicity of biosolids-derived triclosan and triclocarban to six crop species.

    Science.gov (United States)

    Prosser, Ryan S; Lissemore, Linda; Solomon, Keith R; Sibley, Paul K

    2014-08-01

    Biosolids are an important source of nutrients and organic matter, which are necessary for the productive cultivation of crop plants. Biosolids have been found to contain the personal care products triclosan and triclocarban at high concentrations relative to other pharmaceuticals and personal care products. The present study investigates whether exposure of 6 plant species (radish, carrot, soybean, lettuce, spring wheat, and corn) to triclosan or triclocarban derived from biosolids has an adverse effect on seed emergence and/or plant growth parameters. Plants were grown in soil amended with biosolids at a realistic agronomic rate. Biosolids were spiked with triclosan or triclocarban to produce increasing environmentally relevant exposures. The concentration of triclosan and triclocarban in biosolids-amended soil declined by up to 97% and 57%, respectively, over the course of the experiments. Amendment with biosolids had a positive effect on the majority of growth parameters in radish, carrot, soybean, lettuce, and wheat plants. No consistent triclosan- or triclocarban-dependent trends in seed emergence and plant growth parameters were observed in 5 of 6 plant species. A significant negative trend in shoot mass was observed for lettuce plants exposed to increasing concentrations of triclocarban (ptriclosan and triclocarban pose a negligible risk to seed emergence and growth of crop plants.

  9. Effects of a chronic lower range of triclosan exposure to a stream mesocosm community

    Science.gov (United States)

    Nietch, C.T.; Quinlan, E.L.; Lazorchak, J.; Impellitteri, C.; Raikow, D.; Walters, David M.

    2013-01-01

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is an antimicrobial found in consumer soaps and toothpaste. It is in treated wastewater effluents at low part per billion concentrations, representing a potentially chronic exposure condition for biota inhabiting receiving streams. A naturally colonized benthos was created using flow-through indoor mesocosms. Then the benthic communities were dosed to achieve different in-stream triclosan concentrations (Control, 0.1, 0.5, 1.0, 5.0, and 10 µg/L) for 56 days. Water quality parameters and endpoints from bacteria to macroinvertebrates plus interacting abiotic components were measured. Effects of triclosan on specific microbial endpoints were observed at all doses, including an effect on litter decomposition dynamics at doses 1.0 µg/L and higher. Resistance of periphytic bacteria to triclosan significantly increased in doses 0.5 µg/L and above. By the end of dosing, the antimicrobial appeared to stimulate the stream periphyton at the three lowest doses while the two highest doses exhibited decreased stocks of periphyton, including significantly lower bacteria cell densities, and cyanobacteria abundance compared to the control. Beside an effect on benthic ostracods, the changes that occurred in the periphyton did not translate to significant change in the colonizing nematodes, the macroinvertebrate community as a whole, or other measurements of stream function. The results shed light on the role a low, chronic exposure to triclosan may play in effluent dominated streams.

  10. In Vitro Bactericidal Activity of 4- and 5-Chloro-2-hydroxy-N-[1-oxo-1-(phenylaminoalkan-2-yl]benzamides against MRSA

    Directory of Open Access Journals (Sweden)

    Iveta Zadrazilova

    2015-01-01

    Full Text Available A series of nine substituted 2-hydroxy-N-[1-oxo-1-(phenylaminoalkan-2-yl]benzamides was assessed as prospective bactericidal agents against three clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA and S. aureus ATCC 29213 as the reference and quality control strain. The minimum bactericidal concentration was determined by subculturing aliquots from MIC determination onto substance-free agar plates. The bactericidal kinetics of compounds 5-chloro-2-hydroxy-N-[(2S-3-methyl-1-oxo-1-{[4-(trifluoromethylphenyl]amino}butan-2-yl]benzamide (1f, N-{(2S-1-[(4-bromophenylamino]-3-methyl-1-oxobutan-2-yl}-4-chloro-2-hydroxybenzamide (1g, and 4-chloro-N-{(2S-1-[(3,4-dichlorophenylamino]-3-methyl-1-oxobutan-2-yl}-2-hydroxybenzamide (1h was established by time-kill assay with a final concentration of the compound equal to 1x, 2x, and 4x MIC; aliquots were removed at 0, 4, 6, 8, and 24 h time points. The most potent bactericidal agent was compound 1f exhibiting remarkable rapid concentration-dependent bactericidal effect even at 2x MIC at 4, 6, and 8 h (with a reduction in bacterial count ranging from 3.08 to 3.75 log10 CFU/mL and at 4x MIC at 4, 6, 8, and 24 h (5.30 log10 CFU/mL reduction in bacterial count after incubation against MRSA 63718. Reliable bactericidal effect against other strains was maintained at 4x MIC at 24 h.

  11. Study of the mechanism of permeabilization of lecithin liposomes and rat liver mitochondria by the antimicrobial drug triclosan.

    Science.gov (United States)

    Belosludtsev, Konstantin N; Belosludtseva, Natalia V; Tenkov, Kirill S; Penkov, Nikita V; Agafonov, Alexey V; Pavlik, Lyubov L; Yashin, Valery A; Samartsev, Victor N; Dubinin, Mikhail V

    2017-09-19

    The effect of the antimicrobial compound triclosan (5-chloro-2'-(2,4-dichlorophenoxy)phenol;) on the permeability of lecithin liposomes and rat liver mitochondria was studied. It was found that triclosan was able to increase nonspecific permeability of liposomes in a dose-dependent manner, which was detected by the release of the fluorescent probe sulforhodamine B (SRB) from vesicles. A partial release of SRB occurs instantly at the moment of triclosan addition, which is followed by a slow leakage of the dye. The triclosan-induced release of SRB from liposomes grew as pH of the medium was decreased from 9.5 to 7.5. As revealed by the laurdan generalized polarization (GP) technique, triclosan increased laurdan GP in lecithin liposomes, indicating a decrease in membrane fluidity. Measurements of GP as a function of fluorescence excitation wavelength gave an ascending line for triclosan-containing liposomes, which can be interpreted as phase heterogeneity of the lipid/triclosan system. Dynamic light scattering experiments also showed that at a high triclosan-to-lipid molar ratio (~0.5), a population of smaller light-scattering particles (~0.4 of the size of liposomes) appear in the system. Experiments with rat liver mitochondria demonstrated that triclosan (10-70μM) induced a high-amplitude cyclosporin А-insensitive swelling of the organelles accompanied the release of cytochrome c. On the basis of the results obtained, possible mechanisms of the toxic effect of triclosan in eukaryotic cells are discussed. Copyright © 2017. Published by Elsevier B.V.

  12. Endocrine Disrupting Effects of Triclosan on the Placenta in Pregnant Rats.

    Directory of Open Access Journals (Sweden)

    Yixing Feng

    Full Text Available Triclosan (TCS is a broad-spectrum antimicrobial agent that is frequently used in pharmaceuticals and personal care products. Reports have shown that TCS is a potential endocrine disruptor; however, the potential effects of TCS on placental endocrine function are unclear. The aim of this study was to investigate the endocrine disrupting effects of TCS on the placenta in pregnant rats. Pregnant rats from gestational day (GD 6 to GD 20 were treated with 0, 30, 100, 300 and 600 mg/kg/d TCS followed by analysis of various biochemical parameters. Of the seven tissues examined, the greatest bioaccumulation of TCS was observed in the placenta. Reduction of gravid uterine weight and the occurrence of abortion were observed in the 600 mg/kg/d TCS-exposed group. Moreover, hormone detection demonstrated that the serum levels of progesterone (P, estradiol (E2, testosterone (T, human chorionic gonadotropin (hCG and prolactin (PRL were decreased in groups exposed to higher doses of TCS. Real-time quantitative reverse transcriptase-polymerase chain reaction (Q-RT-PCR analysis revealed a significant increase in mRNA levels for placental steroid metabolism enzymes, including UDP-glucuronosyltransferase 1A1 (UGT1A1, estrogen sulfotransferase 1E1 (SULT1E1, steroid 5α-reductase 1 (SRD5A1 and steroid 5α-reductase 2 (SRD5A2. Furthermore, the transcriptional expression levels of progesterone receptor (PR, estrogen receptor (ERα and androgen receptor (AR were up-regulated. Taken together, these data demonstrated that the placenta was a target tissue of TCS and that TCS induced inhibition of circulating steroid hormone production might be related to the altered expression of hormone metabolism enzyme genes in the placenta. This hormone disruption might subsequently affect fetal development and growth.

  13. Triclosan-Induced Aminoglycoside-Tolerant Listeria monocytogenes Isolates Can Appear as Small-Colony Variants

    DEFF Research Database (Denmark)

    Kastbjerg, Vicky Gaedt; Hein-Kristensen, Line; Gram, Lone

    2014-01-01

    Exposure of the human food-borne pathogen Listeria monocytogenes to sublethal concentrations of triclosan can cause resistance to several aminoglycosides. Aminoglycoside-resistant isolates exhibit two colony morphologies: normal-size and pinpoint colonies. The purposes of the present study were...... to characterize the small colonies of L. monocytogenes and to determine if specific genetic changes could explain the triclosan-induced aminoglycoside resistance in both pinpoint and normal-size isolates. Isolates from the pinpoint colonies grew poorly under aerated conditions, but growth was restored by addition......, and addition of heme caused the pinpoint isolates to revert to normal colony size. Triclosan-induced gentamicin-resistant isolates had mutations in several different genes, and it cannot be directly concluded how the different mutations caused gentamicin resistance. However, since many of the mutations...

  14. Altered antibiotic tolerance in anaerobic digesters acclimated to triclosan or triclocarban.

    Science.gov (United States)

    Carey, Daniel E; McNamara, Patrick J

    2016-11-01

    Bench-scale anaerobic digesters were amended to elevated steady-state concentrations of triclosan (850 mg/kg) and triclocarban (150 mg/kg) using a synthetic feed. After more than 9 solids retention time (SRT) values of acclimatization, biomass from each digester (and a control digester that received no antimicrobials) was used to assess the toxicity of three antibiotics. Methane production rate was measured as a surrogate for activity in microcosms that received doses of antibiotics ranging from no-antibiotic to inhibitory concentrations. Biomass amended with triclocarban was more sensitive to tetracycline compared to the control indicating synergistic inhibitory effects between this antibiotic and triclocarban. In contrast, biomass amended with triclosan was able to tolerate statistically higher levels of ciprofloxacin indicating that triclosan can induce functional resistance to ciprofloxacin in an anaerobic digester community.

  15. Use of the Malthus-AT system to assess the efficacy of permeabilizing agents on the activity of antibacterial agents against Pseudomonas aeruginosa.

    Science.gov (United States)

    Ayres, H M; Payne, D N; Furr, J R; Russell, A D

    1998-06-01

    The Malthus-AT system provided a satisfactory method for examining the effects of permeabilizing agents on the activity of sub-inhibitory concentrations of antibacterial agents against Pseudomonas aeruginosa G48. Under this system, disodium edetate potentiated the activity of chlorhexidine diacetate (CHA), cetylpyridinium chloride, para-chlorometaxylenol and triclosan. Nitrilotriacetic acid enhanced the activity of some of the antibacterials tested, whereas sodium polyphosphate markedly reduced the efficacy of CHA.

  16. Green Synthesis of Silver Nanoparticles and Their Bactericidal and Antimycotic Activities against Oral Microbes

    Directory of Open Access Journals (Sweden)

    Osvelia E. Rodríguez-Luis

    2016-01-01

    Full Text Available Nanotechnology is a new discipline with huge applications including medicine and pharmacology industries. Although several methods and reducing agents have been employed to synthesize silver nanoparticles, reactive chemicals promote toxicity and nondesired effects on the human and biological systems. The objective of this work was to synthesize silver nanoparticles from Glycyrrhiza glabra and Amphipterygium adstringens extracts and determine their bactericidal and antimycotic activities against Enterococcus faecalis and Candida albicans growth, respectively. 1 and 10 mM silver nitrate were mixed with an extract of Glycyrrhiza glabra and Amphipterygium adstringens. Green silver nanoparticles (AgNPs were characterized by TEM, Vis-NIR, FTIR, fluorescence, DLS, TGA, and X-ray diffraction (XRD analysis. Bactericidal and antimycotic activities of AgNPs were determined by Kirby and Bauer method and cell viability MTT assays. AgNPs showed a spherical shape and average size of 9 nm if prepared with Glycyrrhiza glabra extract and 3 nm if prepared with Amphipterygium adstringens extract. AgNPs inhibited the bacterial and fungal growth as was expected, without a significant cytotoxic effect on human epithelial cells. Altogether, these results strongly suggest that AgNPs could be an interesting option to control oral biofilms.

  17. Efficiency of Chlorine Dioxide as a Bactericide1

    Science.gov (United States)

    Benarde, Melvin A.; Israel, Bernard M.; Olivieri, Vincent P.; Granstrom, Marvin L.

    1965-01-01

    We found chlorine dioxide to be a more effective disinfectant than chlorine in sewage effluent at pH 8.5. Chlorine dioxide was also found to be a more stable bactericide in relation to pH in the range studied. Images Fig. 1 PMID:5325940

  18. Studies on bactericidal efficacy of pumpkin (Cucurbita moschata Duchesne) peel

    Institute of Scientific and Technical Information of China (English)

    El Zawane Kamarudin; Qamar Uddin Ahmed; Zuvairea Nazren Mohd Sirajudin; Ahmad Jalal Khan Chowdhury

    2014-01-01

    Objective: To explore the in vitro antibacterial potential of the peel of Cucurbita moschata Duchesne (tropical pumpkin) (C. moschata) against human pathogenic bacteria. Methods:In the present study, dichloromethane (DCM), methanol (MEOH) and aqueous extracts of C. moschata peel were examined for in vitro antibacterial potency against eight bacterial strains i.e. Bacillus cereus, Burkholderia cepacia, Escherichia coli, Enterococcus faecalis, Staphyloccocus aureus, Pseudomonas aerugenosa, Vibrio alginolyticus, Vibrio parahaemolyticus using Kirby-Bauer disk diffusion susceptibility and broth micro-dilution methods. Results: DCM extract of pumpkin peel exhibited the maximum zone of inhibition against Staphyloccocus aureus (21 mm) whereas aqueous extract of pumpkin peel revealed the least zone of inhibition against Escherichia coli (8 mm). MEOH extract gave maximum zone of inhibition against Pseudomonas aerugenosa (19 mm). Broth micro-dilution method showed minimum inhibitory concentration for the DCM extract against Burkholderia cepacia at 6.25 mg/mL. The minimum bactericidal concentrations were also determined to know the nature of all extracts. DCM and MEOH extracts exhibited bactericidal nature to all bacterial strains except for the Vibrio alginolyticus. The minimum bactericidal concentrations values exhibited bactericidal nature ranging from 3.12 mg/mL to 100.00 mg/mL. The screening of antimicrobial properties of different extracts of C. moschata peel revealed that the DCM extract possessed good antimicrobial efficacy compared to MEOH and aqueous extracts. Conclusions: Peel of C. moschata possesses antibacterial compounds and could be potential source for a new class of antibiotics.

  19. Two Major Medicinal Honeys Have Different Mechanisms of Bactericidal Activity

    NARCIS (Netherlands)

    Kwakman, P.H.S.; te Velde, A.A.; de Boer, L.; Vandenbroucke-Grauls, C.M.J.E.; Zaat, S.A.J.

    2011-01-01

    Honey is increasingly valued for its antibacterial activity, but knowledge regarding the mechanism of action is still incomplete. We assessed the bactericidal activity and mechanism of action of Revamil (R) source (RS) honey and manuka honey, the sources of two major medical-grade honeys. RS honey k

  20. Mutacin II, a Bactericidal Lantibiotic from Streptococcus mutans

    NARCIS (Netherlands)

    Chikindas, Michael L.; Novák, Jan; Driessen, Arnold J.M.; Konings, Wilhelmus; Schilling, Kurt M.; Caufield, Page W.

    1995-01-01

    Mutacin II is a lantibiotic that is produced by group II Streptococcus mutans, it inhibits the growth of other streptococci as well as many other gram-positive microorganisms by a hitherto unknown mechanism, Mutacin LI possesses bactericidal activity against susceptible cells. It transiently depolar

  1. Bactericidal activity of glutaraldehyde-like compounds from olive products.

    Science.gov (United States)

    Medina, Eduardo; Brenes, Manuel; García, Aranzazu; Romero, Concepción; de Castro, Antonio

    2009-12-01

    The bactericidal effects of several olive compounds (nonenal, oleuropein, tyrosol, the dialdehydic form of decarboxymethyl elenolic acid either free [EDA] or linked to tyrosol [TyEDA] or to hydroxytyrosol [HyEDA]), other food phenolic compounds (catechin, epicatechin, eugenol, thymol, carvacrol, and carnosic acid), and commercial disinfectants (glutaraldehyde [GTA] and ortho-phthalaldehyde [OPA]), were tested against strains of Pseudomonas fluorescens, Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli. It was found that the bactericidal activities of olive GTA-like compounds (EDA, HyEDA, and TyEDA) were greater than those exerted by several food phenolic substances. Surprisingly, these olive antimicrobials were as active as the synthetic biocides GTA and OPA against the four bacteria studied. Thus, it has been proposed that the bactericidal activity of the main olive antimicrobials is primarily due to their dialdehydic structure, which is similar to that of the commercial biocides GTA and OPA. Our results clearly reveal that olive GTA-like compounds possess a strong bactericidal activity even greater than that of other food phenolic compounds or synthetic biocides.

  2. Use of the mouse spot test to investigate the mutagenic potential of triclosan (Irigasan DP300)

    Energy Technology Data Exchange (ETDEWEB)

    Russell, L.B.; Montgomery, C.S.

    1980-01-01

    Triclosan, a chlorophenoxyphenol used in several commercial products, was tested in the mouse in vivo somatic mutation test (spot test) by intraperitoneal injection on day 9.25 or 10.25 postconception. Although the dose range tested overlapped the toxic, the frequency of presumed somatic mutations was not significantly greater in the experimental groups than in the methanol-injected controls; and the results rule out with 95% confidence a spot incidence 5 or more times greater than the control incidence. These findings fail to confirm the claim by Fahrig et al. (1978) that triclosan is mutagenic in the spot test.

  3. Removal mechanisms and plant species selection by bioaccumulative factors in surface flow constructed wetlands (CWs): In the case of triclosan.

    Science.gov (United States)

    Zhao, Congcong; Xie, HuiJun; Xu, Jingtao; Zhang, Jian; Liang, Shuang; Hao, Jingcheng; Ngo, Huu Hao; Guo, Wenshan; Xu, Xiaoli; Wang, Qian; Wang, Jingmin

    2016-03-15

    Plants can bioaccumulate triclosan and bond with microbes and sediments in constructed wetlands (CWs) as well. However, little is known regarding the species-specific removal mechanism of CWs components and the selection of suitable wetland plant species for triclosan disposal. In this work, the use of bioaccumulation factors (BAFs) and biota to sediment accumulation factors (BSAFs) for choosing the best triclosan removal plant species was studied in laboratory-scale CWs. By the end of the experiment, over 80% of triclosan was removed and a specie-effect distribution was revealed in CWs with emergent, submerged and floating plants. By mass balance calculation, negative correlation between triclosan concentration in plants and degradation process was observed. The significant correlations between Log BSAFs values and triclosan concentration in plants or degradation contribution made it possible and reasonable in wetland plants selection. Introductions on plant species were provided considering the target removal process or regulation method. This work provided new information on plant species selection in CWs for triclosan removal or its emergency remediation by using bioaccumulative factors. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Anti-bactericidal properties of stingray Dasyatis pastinaca groups V, IIA, and IB phospholipases A2: a comparative study.

    Science.gov (United States)

    Bacha, Abir Ben

    2014-10-01

    Group IIA secreted phospholipase A2 (group IIA sPLA2) is known to display potent Gram-positive bactericidal activity in vitro and in vivo. We have analyzed the bactericidal activity of the full set of native stingray and dromedary groups V, IIA, and IB sPLA2s on several Gram-positive and Gram-negative strains. The rank order potency among both marine and mammal sPLA2s against Gram-positive bacteria is group IIA > V > IB, whereas Gram-negative bacteria exhibited a much higher resistance. There is a synergic action of the sPLA2 with lysozyme when added to the bacteria culture prior to sPLA2.The bactericidal efficiency of groups V and IIA sPLA2s was shown to be dependent upon the presence of calcium ions and to a less extent Mg(2+) ions and then a correlation could be made to its hydrolytic activity of membrane phospholipids. Importantly, we showed that stingray and dromedary groups V, IIA, and IB sPLA2s present no cytotoxicity after their incubation with MDA-MB-231cells. stingray groups V and IIA sPLA2s, like mammal ones, may be considered as future therapeutic agents against bacterial infections.

  5. Altered Competitive Fitness, Antimicrobial Susceptibility, and Cellular Morphology in a Triclosan-Induced Small-Colony Variant of Staphylococcus aureus.

    Science.gov (United States)

    Forbes, Sarah; Latimer, Joe; Bazaid, Abdulrahman; McBain, Andrew J

    2015-08-01

    Staphylococcus aureus can produce small-colony variants (SCVs) that express various phenotypes. While their significance is unclear, SCV propagation may be influenced by relative fitness, antimicrobial susceptibility, and the underlying mechanism. We have investigated triclosan-induced generation of SCVs in six S. aureus strains, including methicillin-resistant S. aureus (MRSA). Parent strains (P0) were repeatedly passaged on concentration gradients of triclosan using a solid-state exposure system to generate P10. P10 was subsequently passaged without triclosan to generate X10. Susceptibility to triclosan and 7 antibiotics was assessed at all stages. For S. aureus ATCC 6538, SCVs were further characterized by determining microbicide susceptibility and competitive fitness. Cellular morphology was examined using electron microscopy, and protein expression was evaluated through proteomics. Triclosan susceptibility in all SCVs (which could be generated from 4/6 strains) was markedly decreased, while antibiotic susceptibility was significantly increased in the majority of cases. An SCV of S. aureus ATCC 6538 exhibited significantly increased susceptibility to all tested microbicides. Cross-wall formation was impaired in this bacterium, while expression of FabI, a target of triclosan, and IsaA, a lytic transglycosylase involved in cell division, was increased. The P10 SCV was 49% less fit than P0. In summary, triclosan exposure of S. aureus produced SCVs in 4/6 test bacteria, with decreased triclosan susceptibility but with generally increased antibiotic susceptibility. An SCV derived from S. aureus ATCC 6538 showed reduced competitive fitness, potentially due to impaired cell division. In this SCV, increased FabI expression could account for reduced triclosan susceptibility, while IsaA may be upregulated in response to cell division defects.

  6. Antibacterial activity of four mouthrinses containing triclosan against salivary Staphylococcus aureus Atividade antibacteriana de quatro anti-sépticos bucais contendo triclosan contra Staphylococcus aureus da saliva

    Directory of Open Access Journals (Sweden)

    Juliane Maria Guerreiro Tanomaru

    2008-09-01

    Full Text Available The maximum inhibitory dilution (MID of triclosan-based mouthwashes against 28 Staphylococcus aureus strains was evaluated. Dilutions ranging from 1/10 to 1/655,360 were prepared. Strains were inoculated using a Steers multipoint inoculator. The MID was considered as the maximum dilution capable of inhibiting microorganism growth. The mouthwashes presented different MIDs.A Diluição Inibitória Máxima (DIM de anti-sépticos bucais à base de triclosan contra 28 cepas de Staphylococcus aureus foi avaliada. Diluições de 1/10 a 1/655.360 foram preparadas. As cepas foram inoculadas com inoculador multipontual Steers. A DIM foi a maior diluição do anti-séptico que inibiu crescimento microbiano. Os anti-sépticos apresentaram diferentes DIMs.

  7. A Kunitz proteinase inhibitor from corms of Xanthosoma blandum with bactericidal activity.

    Science.gov (United States)

    Lima, Thaís B; Silva, Osmar N; Migliolo, Ludovico; Souza-Filho, Carlos R; Gonçalves, Eduardo G; Vasconcelos, Ilka M; Oliveira, José T A; Amaral, André C; Franco, Octávio L

    2011-05-27

    Bacterial infections directly affect the world's population, and this situation has been aggravated by indiscriminate use of antimicrobial agents, which can generate resistant microorganisms. In this report, an initial screening of proteins with antibacterial activity from corms of 15 species of the Xanthosoma genus was conducted. Since Xanthosoma blandum corms showed enhanced activity toward bacteria, a novel protein with bactericidal activity was isolated from this particular species. Edman degradation was used for protein N-termini determination; the primary structure showed similarities with Kunitz inhibitors, and this protein was named Xb-KTI. This protein was further challenged against serine proteinases from different sources, showing clear inhibitory activities. Otherwise, no hemolytic activity was observed for Xb-KTI. The results demonstrate the biotechnological potential of Xb-KTI, the first proteinase inhibitor with antimicrobial activity described in the Xanthosoma genus.

  8. Synthesis of nanosilver particles by reverse micelle method and study of their bactericidal properties

    Science.gov (United States)

    Dung, Tran Thi Ngoc; Buu, Ngo Quoc; Viet Quang, Dang; Thi Ha, Huynh; Bang, Le Anh; Hoai Chau, Nguyen; Thi Ly, Nguyen; Trung, Nguyen Vu

    2009-09-01

    Nanosilver particles have been synthesized by the reverse micelle method, where AgNO3 was used as a silver ions source, NaBH4 and quercetin - as reducing agents, CTAB, SDOSS and AOT- as surfactants, while the stabilizer was Vietnamese chitosan. Studying the factors influencing the process of nanosilver particle formation, it was shown that the particle size of the nanosilver products depends on the concentration of the reaction components and their stoichiometric ratio. It was also shown that the reaction system using AOT surfactant is capable of producing nanosilver particles with smallest nanoparticles (phiav ~ 5 nm) and good particle-size distribution. The study on bactericidal activity of the nanosilver products indicated that the disinfecting solution with a nanosilver concentration of 3 ppm was able to inhibit all E.coli and Coliforms, TPC and fungi at 15 ppm, while Vibrio cholerae cells were inactivated completely with 0.5 ppm of nanosilver after 30 minutes exposition.

  9. Triclocarban, triclosan and its transformation product methyl triclosan in native earthworm species four years after a commercial-scale biosolids application.

    Science.gov (United States)

    Macherius, André; Lapen, David R; Reemtsma, Thorsten; Römbke, Jörg; Topp, Edward; Coors, Anja

    2014-02-15

    Triclocarban (TCC), triclosan (TCS) and methyl triclosan (Me-TCS) were detected in soil and the native population of earthworms of an agricultural field in Ottawa, Canada, about four years after a commercial-scale application of biosolids. In soil that received biosolids, TCC and TCS were detected at median concentrations of 13.0 and 1.5 ng/g soil (d.w.), respectively, while Me-TCS, the transformation product of triclosan, was detected at a six-fold higher median concentration than its precursor. In earthworms collected at the biosolids-amended field-plot about four years post application, Me-TCS was also detected at higher concentrations (26 to 114 ng/g tissue d.w.) than TCS (16-51 ng/g) and TCC (4-53 ng/g). These data provide evidence that not only parent compounds but also their transformation products need to be considered in faunal bioaccumulation studies. Moreover, the preliminary results for pooled earthworm samples from different ecological groups suggest that the degree of bioaccumulation of biosolids-associated contaminants may depend on the habitat and feeding behavior of the organisms.

  10. Evaluation of the bactericidal effect of five products for surgical hand disinfection according to prEN 12054 and prEN 12791.

    Science.gov (United States)

    Marchetti, M G; Kampf, G; Finzi, G; Salvatorelli, G

    2003-05-01

    Surgical hand disinfection (with an alcohol-based hand rub) and surgical handwash (with an antiseptic-based liquid soap) are accepted measures to reduce the risk for surgical site infections. The new European Standards allow a comparison of their antimicrobial efficacy. The bactericidal activity of surgical hand rubs [Sterillium and Softaman, (active ingredient=alcohols)] and handwashes [Derman plus (triclosan), Hibiscrub (chlorhexidine) and Betadine (PVP-iodine)] was tested according to the prEN 12054 suspension test using Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus hirae, and to prEN 12791 for the effect on resident skin flora in comparison with 1-propanol, 60% (v/v). All five products achieved a reduction of test bacteria within 3 min of >10(5)-fold so fulfilling prEN 12054. However, only Hibiscrub, Sterillium and Softa Man met the requirements of prEN 12791, giving a mean reduction of resident micro-organisms (immediate and sustained effect) which was not significantly lower than the reference alcohol (P>0.1; Wilcoxon matched-pairs signed-rank test). Sterillium was significantly more effective than the reference alcohol (immediate and sustained affect). Products for surgical hand disinfection may have equal antimicrobial activity in suspension tests but show large differences under practical conditions. Healthcare workers should not rely on results from suspension tests when deciding on a product for surgical hand disinfection.

  11. Comparison of antimicrobial effect between Triclosan Toothpaste and Nono-Silver Toothpaste

    OpenAIRE

    Chen, Y.(California Institute of Technology, Pasadena, USA); Burns, E; Goh, SH; Wong, R.; Seneviratne, CJ; Hagg, U; Mcgrath, C.; Samaranayake, LP

    2012-01-01

    OBJECTIVE: To evaluate the antimicrobial effect of two commercial available toothpastes in vitro. MATERIALS AND METHODS: Two toothpastes: Colgate Total® toothpaste (triclosan containing) and NanoCare Nano silver® toothpaste (nano-silver containing) were investigated. The antimicrobial effect on bacteria planktonic status was tested by agar diffusion assay. A dual-species biofilm mod...

  12. Triclosan Decreases Rat Thyroxine: Mode-of-Action, Developmental Susceptibility and Human Relevance

    Science.gov (United States)

    Triclosan (TCS) decreases serum thyroxine (T4) in the rat. In vivo and in vitro approaches were used to address three uncertainties: by what mode-of-action (MOA) does TCS decrease T4; does TCS decrease T4 developmentally; and, are effects observed in rats relevant to humans? To t...

  13. Complete Proton and Carbon Assignment of Triclosan via One- and Two- Dimensional Nuclear Magnetic Resonance Analysis

    Science.gov (United States)

    Students from an upper-division undergraduate spectroscopy class analyzed one- and two-dimensional 400 MHz NMR spectroscopic data from triclosan in CDCl3. Guided assignment of all proton and carbon signals was completed via 1D proton and carbon, nuclear Overhauser effect (nOe), distortionless enhanc...

  14. The challenge of predicting problematic chemicals using a decision analysis tool: Triclosan as a case study.

    Science.gov (United States)

    Perez, Angela L; Gauthier, Alison M; Ferracini, Tyler; Cowan, Dallas M; Kingsbury, Tony; Panko, Julie

    2017-01-01

    Manufacturers lack a reliable means for determining whether a chemical will be targeted for deselection from their supply chain. In this analysis, 3 methods for determining whether a specific chemical (triclosan) would meet the criteria necessary for being targeted for deselection are presented. The methods included a list-based approach, use of a commercially available chemical assessment software tool run in 2 modes, and a public interest evaluation. Our results indicated that triclosan was included on only 6 of the lists reviewed, none of which were particularly influential in chemical selection decisions. The results from the chemical assessment tool evaluations indicated that human and ecological toxicity for triclosan is low and received scores indicating that the chemical would be considered of low concern. However, triclosan's peak public interest tracked several years in advance of increased regulatory scrutiny of this chemical suggesting that public pressure may have been influential in deselection decisions. Key data gaps and toxicity endpoints not yet regulated such as endocrine disruption potential or phototoxicity, but that are important to estimate the trajectory for deselection of a chemical, are discussed. Integr Environ Assess Manag 2017;13:198-207. © 2016 SETAC.

  15. Effects of Extended Exposure to the Antibacterial Triclosan in the the Adult Female Rat

    Science.gov (United States)

    Triclosan (TCS), an antibacterial, has been shown to have endocrine disrupting activity in the rat. We reported previously that TCS advanced puberty in the female rat in the female pubertal assay and potentiated the estrogenic effect of ethinyl estradiol (EE) on uterine growth i...

  16. Spatial Distribution of Triclosan in Sediments and Water of an Urbanized Estuarine Embayment

    Science.gov (United States)

    Triclosan (TCS) is a broad spectrum anti-microbial compound found in many consumer and personal care products. TCS enters water bodies primarily through wastewater treatment plant (WWTP) effluent and may also be introduced by combined sewer overflows or surface water runoff. TC...

  17. Fate of triclocarban, triclosan and methyltriclosan during wastewater and biosolids treatment processes

    Science.gov (United States)

    Triclocarban (TCC) and Triclosan (TCS) are two antibacterial chemicals present in household and personal care products. Methyltriclosan is a biodegradation product of TCS formed under aerobic conditions. TCC and TCS are discharged to Waste Water Treatment Plants (WWTP) where they are removed from ...

  18. Effects of Triclosan on Marine Benthic and Epibenthic Organisms (Journal Article)

    Science.gov (United States)

    Triclosan (TCS) is an antimicrobial compound that has been widely used in consumer products, such as toothpaste, deodorant, and shampoo. Due to its widespread use, TCS has been detected in various environmental media including wastewater, sewage sludge, surface waters, and sedim...

  19. Routes of uptake of diclofenac, fluoxetine, and triclosan into sediment-dwelling worms.

    Science.gov (United States)

    Karlsson, Maja V; Marshall, Stuart; Gouin, Todd; Boxall, Alistair B A

    2016-04-01

    The present study investigated the route and degree of uptake of 2 ionizable pharmaceuticals (diclofenac and fluoxetine) and 1 ionizable compound used in personal care products (triclosan) into the sediment-dwelling worm Lumbriculus variegatus. Studies were done on complete worms ("feeding") and worms where the head was absent ("nonfeeding") using (14) C-labeled ingredients. Biota sediment accumulation factors (BSAF), based on uptake of (14) C, for feeding worms increased in the order fluoxetine (0.3) triclosan (9), which is correlated with a corresponding increase in log octanol-water partition coefficient. Biota sediment accumulation factor estimates are representative of maximum values because the degree of biotransformation in the worms was not quantified. Although no significant differences were seen between the uptake of diclofenac and that of fluoxetine in feeding and nonfeeding worms, uptake of the more hydrophobic antimicrobial, triclosan, into the feeding worms was significantly greater than that in the nonfeeding worms, with the 48-h BSAF for feeding worms being 36% higher than that for the nonfeeding worms. The results imply that dietary uptake contributes to the uptake of triclosan, which may be a result of the high hydrophobicity of the compound. Models that estimate exposure of ionizable substances may need to consider uptake from both the water column and food, particularly when assessing risks from dynamic exposures to organic contaminants.

  20. Examining triclosan-induced estrogenic and androgenic effects on the rat reproductive system

    Science.gov (United States)

    Background: Triclosan (TCS), a widely used antibacterial, has been shown to be an endocrine disruptor. We reported previously that TCS potentiated the estrogenic effect of ethinyl estradiol (EE) on uterine growth in female rats co-administered EE (3 μg/kg) and TCS (2 to 18 m...

  1. Removal of two antibacterial compounds triclocarban and triclosan in a waste water treatment plant

    Science.gov (United States)

    This study investigates the fate of Triclocarban (TCC) and Triclosan (TCS) in a waste water treatment plant (WWTP). Our goal was to identify the most effective removal step and to determine the amount on the solid phase versus degraded. Our influent contained higher TCS than TCC concentrations (8....

  2. Using a Novel Sediment Exposure to Determine the Effects of Triclosan on Marine Benthic Communities

    Science.gov (United States)

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol), is an emerging contaminant commonly used as an antimicrobial compound in many personal care products such as softsoap, detergent, toothpaste, mouthwash, and is infused in many consumer products, such as kitchen utensils, toys, b...

  3. Effects of a Chronic Lower Range of Triclosan Exposure on a Stream Mesocosm Community

    Science.gov (United States)

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is an antimicrobial found in consumer soaps and toothpaste. It is in treated wastewater effluents at low part per billion concentrations, representing a potentially chronic exposure condition for biota inhabiting receiving strea...

  4. Fate of Triclosan and Evidence for Reductive Dechlorination of Triclocarban in Estuarine Sediment

    Science.gov (United States)

    The biocides triclosan (TCS) and triclocarban (TCC) are wastewater contaminants whose occurrence and fate in estuarine sediments remain unexplored. We examined contaminant profiles in 137Cs/7Be-dated sediment cores taken near wastewater treatment plants in the Chesapeake Bay watershed (CB), Maryland...

  5. Bactericidal effects of mouth rinses on oral bacteria.

    Science.gov (United States)

    Kasuga, Y; Ikenoya, H; Okuda, K

    1997-11-01

    The bactericidal efficacy of two types of Listerine; Listerine and Cool Mint Listerine, and povidone iodine on oral microorganisms, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pyogenes, Helicobacter pylori and Candida albicans were examined. Most of the oral bacteria were killed completely by a 10-sec exposure to Listerine or Cool Mint Listerine. H. pylori, MRSA and C. albicans were also reduced by a 30-sec exposure to the Listerine mouth rinse. Bacteria in dental plaque were decreased by exposure to Listerine, Cool Mint Listerine, and povidone iodine for 30 seconds. Mouthwashing with Listerine for 30 seconds resulted in a decrease to approximately 1/100 of the viable bacterial counts in saliva. These bactericidal effects against bacteria in saliva and dental plaque indicated that Listerine and Cool Mint Listerine antiseptic are useful in oral cavity as antiseptic mouth rinses.

  6. Urinary levels of triclosan and parabens are associated with aeroallergen and food sensitization

    Science.gov (United States)

    Savage, Jessica H.; Matsui, Elizabeth C.; Wood, Robert A.; Keet, Corinne A.

    2013-01-01

    Background Endocrine-disrupting compounds (EDCs) have immune-modulating effects. We were interested in determining their association with allergic sensitization. Objective To determine the association between EDCs and allergic sensitization and if this relationship depended on the antimicrobial properties of the EDCs and/or gender. Methods Data were obtained from the 2005–2006 National Health and Nutrition Examination Survey in which urinary bisphenol A, triclosan, benzophenone-3, and propyl, methyl, butyl and ethyl paraben, and specific IgE were available on 860 children. Aeroallergen and food sensitization were defined as having at least one positive (≥0.35 kU/L) specific IgE to an aeroallergen or a food. Logistic regression was used to determine the association of EDCs and sensitization. Analyses were adjusted for urinary creatinine, age, ethnicity, and poverty index ratio. Results The odds of aeroallergen sensitization significantly increased with the level of the antimicrobial EDCs triclosan and propyl and butyl paraben (p≤0.04). The odds of food sensitization significantly increased with the level of urinary triclosan among male subjects (odds ratio for 3rd versus 1st tertile 3.9, p=0.02 for trend). There was a significant interaction between gender and triclosan, with males being more likely to be food sensitized with exposure (p=0.03). Similar associations were not identified for the non-antimicrobial EDCs bisphenol A and benzophenone-3 (p>0.2). Conclusions As a group, EDCs are not associated with allergen sensitization. However, levels of the antimicrobial EDCs triclosan and parabens were significantly associated with allergic sensitization. The potential role of antimicrobial EDCs in allergic disease warrants further study as they are commonly used in Western society. PMID:22704536

  7. Simultaneous quantitation of parabens, triclosan, and methyl triclosan in indoor house dust using solid phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Fan, Xinghua; Kubwabo, Cariton; Rasmussen, Pat; Jones-Otazo, Heather

    2010-10-06

    An integrated analytical method for the simultaneous determination of five parabens (methyl-, ethyl-, propyl-, butyl-, and benzyl-), triclosan, and methyl triclosan in indoor house dust was developed based on gas chromatographic-mass spectrometric technique (GC/MS). Analytes were extracted from dust samples by sonication. After sample cleanup by solid-phase extraction (SPE), the extracts were derivatized with N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) and then analyzed by gas chromatography coupled with ion trap mass spectrometry operated in multiple reaction monitoring (MRM) mode. For quantitation, isotope-labelled internal standards were used for each corresponding target analyte. Only 0.05 g of dust sample was needed for the analysis. Method detection limits ranged from 6.5 to 10 ng/g, and absolute recoveries from 74% to 92%. The developed method demonstrated good repeatability and reproducibility, with relative standard deviations (RSDs) less than 16% for all the analytes. The analytes were determined in dust samples collected using two vacuum sampling methods from 63 Canadian homes: a sample of fresh or "active" dust (FD) collected using a Pullman-Holt vacuum sampler, and a composite sample taken from the household vacuum cleaner (HD). Methyl paraben, propyl paraben, and triclosan were detected in all HD and FD samples. HD samples yielded median values for methyl paraben, propyl paraben, and triclosan of 1080, 463, and 378 ng/g, respectively, which were comparable to the FD sample medians of 1120, 618 and 571 ng/g. Ethyl paraben was detected at frequencies of 89% in FD and 73% in HD samples, with median values of 52 and 25 ng/g, respectively. Butyl paraben was detected at frequencies of 44% in FD and 75% in HD samples, with median values of paraben and methyl triclosan were not detected in any of the samples collected by either method. Samples collected according to the fresh dust protocol agreed with the household vacuum samples 90% of the time

  8. Studies on bactericidal efficacy of pumpkin (Cucurbita moschata Duchesne peel

    Directory of Open Access Journals (Sweden)

    El Zawane Kamarudin

    2014-02-01

    Full Text Available Objective: T o explore the in vitro antibacterial potential of the peel of Cucurbita moschata D uchesne ( tropical pumpkin ( C. moschata against human pathogenic bacteria. Methods: I n the present study, dichloromethane ( DCM , methanol ( MEOH and aqueous extracts of C. moschata peel were examined for in vitro antibacterial potency against eight bacterial strains i.e. Bacillus cereus, Burkholderia cepacia, Escherichia coli, Enterococcus faecalis, Staphyloccocus aureus, Pseudomonas aerugenosa, Vibrio alginolyticus, Vibrio parahaemolyticus using K irby- B auer disk diffusion susceptibility and broth micro-dilution methods. Results: DCM extract of pumpkin peel exhibited the maximum zone of inhibition against Staphyloccocus aureus ( 21 mm whereas aqueous extract of pumpkin peel revealed the least zone of inhibition against Escherichia coli ( 8 mm . MEOH extract gave maximum zone of inhibition against Pseudomonas aerugenosa ( 19 mm . B roth micro-dilution method showed minimum inhibitory concentration for the DCM extract against Burkholderia cepacia at 6 . 25 mg/m L . T he minimum bactericidal concentrations were also determined to know the nature of all extracts. DCM and MEOH extracts exhibited bactericidal nature to all bacterial strains except for the Vibrio alginolyticus. T he minimum bactericidal concentrations values exhibited bactericidal nature ranging from 3 . 12 mg/m L to 100 . 00 mg/m L . T he screening of antimicrobial properties of different extracts of C. moschata peel revealed that the DCM extract possessed good antimicrobial efficacy compared to MEOH and aqueous extracts. Conclusions: P eel of C. moschata possesses antibacterial compounds and could be potential source for a new class of antibiotics.

  9. TLR signaling augments macrophage bactericidal activity through mitochondrial ROS

    OpenAIRE

    West, A. Phillip; Brodsky, Igor E.; Rahner, Christoph; Woo, Dong Kyun; Erdjument-Bromage, Hediye; Tempst, Paul; Walsh, Matthew C; Choi, Yongwon; Shadel, Gerald S.; Ghosh, Sankar

    2011-01-01

    Reactive oxygen species (ROS) are essential components of the innate immune response against intracellular bacteria, and it is thought that professional phagocytes generate ROS primarily via the phagosomal NADPH oxidase (Phox) machinery 1 . However, recent studies have suggested that mitochondrial ROS (mROS) also contribute to macrophage bactericidal activity, although the mechanisms linking innate immune signaling to mitochondria for mROS generation remain unclear 2-4 . Here we demonstrate t...

  10. Bactericidal activity of titanium dioxide ultraviolet-induced films

    Energy Technology Data Exchange (ETDEWEB)

    Pleskova, S.N., E-mail: pleskova@mail.ru [Laboratory of Biochemistry and Molecular Biology, Tomsk State University, ave. Lenina 36, Tomsk 634050 (Russian Federation); Golubeva, I.S., E-mail: golubmay@mail.ru [Institute of applied biotechnology of Nizhny Novgorod, Yablonevaya Street 22, Nizhny Novgorod 603093 (Russian Federation); Verevkin, Y.K., E-mail: verevkin@appl.sci-nnov.ru [Institute of applied physics of the Russian Academy of Science, Ul' yanov Street, 46, Nizhny Novgorod 603950 (Russian Federation)

    2016-02-01

    TiO{sub 2} films are used as a self-sterilization surface due to their property to form reactive oxygen species (ROS) when irradiated with ultraviolet light. These ROS attack bacteria and kill them. We present a new way to enhance the bactericidal activity of TiO{sub 2}-films: formation of nanopores on the surface by four-beam high-power laser irradiation. Such surfaces have significantly higher antibacterial activity as compared to conventional TiO{sub 2} surfaces after 15 and 60 min of UV irradiation. Study of the bacterial cell morphology by atomic force microscopy after 60 min irradiation showed that Staphylococcus aureus 956 and Escherichia coli 321–5 undergo significant morphological changes. S. aureus assume atypical elongated shapes after UV treatment alone and swollen forms with protrusions after UV treatment on TiO{sub 2} surface. E. coli exhibit oval or round forms after UV treatment alone, and round forms with small protrusions, and destroyed cells after incubation under UV on the TiO{sub 2} film. - Highlights: • Nanopores on the TiO{sub 2} surface enhance the bactericidal activity of films. • The bactericidal effect of TiO{sub 2} is strain-specific. • The bacterial morphology significantly changes after UV/TiO{sub 2} treatment.

  11. Effects of Chronic Exposure to Triclosan on Reproductive and Thyroid Endpoints in the Adult Wistar Female Rat

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes the results of a long term adult female rat oral exposure to triclosan and includes hormone, estrous cyclicity, thyroid histology and liver...

  12. Bacterial community variation and microbial mechanism of triclosan (TCS) removal by constructed wetlands with different types of plants.

    Science.gov (United States)

    Zhao, Congcong; Xie, HuiJun; Xu, Jingtao; Xu, Xiaoli; Zhang, Jian; Hu, Zhen; Liu, Cui; Liang, Shuang; Wang, Qian; Wang, Jingmin

    2015-02-01

    Triclosan (TCS) is a broad-spectrum synthetic antimicrobial agent that is toxic to microbes and other aquatic organisms. Constructed wetlands (CWs) are now popular in TCS removal. However, knowledge on the effects of TCS on the bacterial community and microbial removal mechanism in CWs is lacking. The effects of TCS (60 μg L(-1)) on bacterial communities in batch-loaded CWs with emergent (Typha angustifolia), submerged (Hydrilla verticillata), and floating plant (Salvinia natans) were analyzed by 454 pyrosequencing technology. After six periods of experiment, the TCS removal efficiencies were over 90% in CWs, and negative effects of TCS on bacterial community richness and diversity were observed. Moreover, plant species effect existed. Bacterial strains that contributed to TCS biodegradation in CWs were successfully identified. In TCS-treated T. angustifolia and H. verticillata CWs, beta-Proteobacteria increased by 16.63% and 18.20%, respectively. In TCS-treated S. natans CWs, delta- and gamma-Proteobacteria and Sphingobacteria increased by 9.36%, 19.49%, and 31.37%, respectively, and could relate to TCS biodegradation. TCS affected the development of certain bacteria, and eventually, the bacterial community structures in CWs. This research provided ecologically relevant information on bacterial community and microbial removal mechanism in CWs under TCS treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Occurrence of triclosan, triclocarban, and its lesser chlorinated congeners in Minnesota freshwater sediments collected near wastewater treatment plants

    Science.gov (United States)

    Venkatesan, Arjun K.; Pycke, Benny F.G.; Barber, Larry B.; Lee, Kathy E.; Halden, Rolf U.

    2012-01-01

    The antimicrobial agents triclosan (TCS), triclocarban (TCC) and their associated transformation products are of increasing concern as environmental pollutants due to their potential adverse effects on humans and wildlife, including bioaccumulation and endocrine-disrupting activity. Analysis by tandem mass spectrometry of 24 paired freshwater bed sediment samples (top 10 cm) collected by the U.S. Geological Survey near 12 wastewater treatment plants (WWTPs) in Minnesota revealed TCS and TCC concentrations of up to 85 and 822 ng/g dry weight (dw), respectively. Concentrations of TCS and TCC in bed sediments collected downstream of WWTPs were significantly greater than upstream concentrations in 58% and 42% of the sites, respectively. Dichloro- and non-chlorinated carbanilides (DCC and NCC) were detected in sediments collected at all sites at concentrations of up to 160 and 1.1 ng/g dw, respectively. Overall, antimicrobial concentrations were significantly higher in lakes than in rivers and creeks, with relative abundances decreasing from TCC > TCS > DCC > NCC. This is the first statewide report on the occurrence of TCS, TCC and TCC transformation products in freshwater sediments. Moreover, the results suggest biological or chemical TCC dechlorination products to be ubiquitous in freshwater environments of Minnesota, but whether this transformation occurs in the WWTP or bed sediment remains to be determined.

  14. Modification of triclosan scaffold in search of improved inhibitors for enoyl-acyl carrier protein (ACP) reductase in Toxoplasma gondii.

    Science.gov (United States)

    Stec, Jozef; Fomovska, Alina; Afanador, Gustavo A; Muench, Stephen P; Zhou, Ying; Lai, Bo-Shiun; El Bissati, Kamal; Hickman, Mark R; Lee, Patty J; Leed, Susan E; Auschwitz, Jennifer M; Sommervile, Caroline; Woods, Stuart; Roberts, Craig W; Rice, David; Prigge, Sean T; McLeod, Rima; Kozikowski, Alan P

    2013-07-01

    Through our focused effort to discover new and effective agents against toxoplasmosis, a structure-based drug design approach was used to develop a series of potent inhibitors of the enoyl-acyl carrier protein (ACP) reductase (ENR) enzyme in Toxoplasma gondii (TgENR). Modifications to positions 5 and 4' of the well-known ENR inhibitor triclosan afforded a series of 29 new analogues. Among the resulting compounds, many showed high potency and improved physicochemical properties in comparison with the lead. The most potent compounds 16 a and 16 c have IC50 values of 250 nM against Toxoplasma gondii tachyzoites without apparent toxicity to the host cells. Their IC50 values against recombinant TgENR were found to be 43 and 26 nM, respectively. Additionally, 11 other analogues in this series had IC50 values ranging from 17 to 130 nM in the enzyme-based assay. With respect to their excellent in vitro activity as well as improved drug-like properties, the lead compounds 16 a and 16 c are deemed to be excellent starting points for the development of new medicines to effectively treat Toxoplasma gondii infections. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Effects of triclosan on the early life stages and reproduction of medaka Oryzias latipes and induction of hepatic vitellogenin.

    Science.gov (United States)

    Ishibashi, Hiroshi; Matsumura, Naomi; Hirano, Masashi; Matsuoka, Munekazu; Shiratsuchi, Hideki; Ishibashi, Yasuhiro; Takao, Yuji; Arizono, Koji

    2004-04-14

    Triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) is widely used as antibacterial agent in various industrial products, such as textile goods, soap, shampoo, liquid toothpaste and cosmetics, and often detected in wastewater effluent. In this study, the effects of TCS on the early life stages and reproduction of medaka (Oryzias latipes) were investigated. The 96-h median lethal concentration value of TCS for 24-h-old larvae was 602 microg/l. The hatchability and time to hatching in fertilized eggs exposed to 313 microg/l TCS for 14 days were significantly decreased and delayed, respectively. An assessment of the effects of a TCS 21-day exposure period on the reproduction of paired medaka showed no significant differences in the number of eggs produced and fertility among the control and 20, 100 and 200 microg/l TCS treatment groups. However, concentrations of hepatic vitellogenin were increased significantly in males treated with TCS at 20 and 100 microg/l. In the F(1) generations, although the hatching of embryos in the 20 microg/l treatment showed adverse effects, there was no dose-response relationship between hatchability and TCS treatment levels. These results suggest that TCS has high toxicity on the early life stages of medaka, and that the metabolite of TCS may be a weak estrogenic compound with the potential to induce vitellogenin in male medaka but with no adverse effect on reproductive success and offspring.

  16. Triclosan exposure results in alterations of thyroid hormone status and retarded early development and metamorphosis in Cyprinodon variegatus.

    Science.gov (United States)

    Schnitzler, Joseph G; Frédérich, Bruno; Dussenne, Mélanie; Klaren, Peter H M; Silvestre, Frédéric; Das, Krishna

    2016-12-01

    Thyroid hormones are critically involved in somatic growth, development and metamorphosis of vertebrates. The structural similarity between thyroid hormones and triclosan, an antimicrobial compound widely employed in consumer personal care products, suggests triclosan can have adverse effects on the thyroid system. The sheepshead minnow, Cyprinodon variegatus, is now used in ecotoxicological studies that have recently begun to focus on potential disruption of the thyroid axis by endocrine disrupting compounds. Here, we investigate the in vivo effects of exposure to triclosan (20, 50, and 100μgL(-1)) on the thyroid system and the embryonic and larval development of C. variegatus. Triclosan exposure did not affect hatching success, but delayed hatching time by 6-13h compared to control embryos. Triclosan exposure affected the ontogenetic variations of whole body thyroid hormone concentrations during the larval phase. The T3 peak around 12-15 dph, described to be indicative for the metamorphosis climax in C. variegatus, was absent in triclosan-exposed larvae. Triclosan exposure did not produce any deformity or allometric repatterning, but a delayed development of 18-32h was observed. We conclude that the triclosan-induced disruption of the thyroid system delays in vivo the start of metamorphosis in our experimental model. We observed a global developmental delay of 24-45h, equivalent to 4-7% prolongation of the developmental time in C. variegatus. The costs of delayed metamorphosis can lead to reduction of juvenile fitness and could be a determining factor in the outcome of competitive interactions.

  17. Human fetal exposure to triclosan and triclocarban in an urban population from Brooklyn, New York.

    Science.gov (United States)

    Pycke, Benny F G; Geer, Laura A; Dalloul, Mudar; Abulafia, Ovadia; Jenck, Alizee M; Halden, Rolf U

    2014-01-01

    Triclosan (TCS) and triclocarban (TCC) are antimicrobial agents formulated in a wide variety of consumer products (including soaps, toothpaste, medical devices, plastics, and fabrics) that are regulated by the U.S. Food and Drug Administration (FDA) and U.S. Environmental Protection Agency. In late 2014, the FDA will consider regulating the use of both chemicals, which are under scrutiny regarding lack of effectiveness, potential for endocrine disruption, and potential contribution to bacterial resistance to antibiotics. Here, we report on body burdens of TCS and TCC resulting from real-world exposures during pregnancy. Using liquid chromatography tandem mass spectrometry, we determined the concentrations of TCS, TCC, and its human metabolites (2'-hydroxy-TCC and 3'-hydroxy-TCC) as well as the manufacturing byproduct (3'-chloro-TCC) as total concentrations (Σ-) after conjugate hydrolysis in maternal urine and cord blood plasma from a cohort of 181 expecting mother/infant pairs in an urban multiethnic population from Brooklyn, NY recruited in 2007-09. TCS was detected in 100% of urine and 51% of cord blood samples after conjugate hydrolysis. The interquartile range (IQR) of detected TCS concentrations in urine was highly similar to the IQR reported previously for the age-matched population of the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2004, but typically higher than the IQR reported previously for the general population (detection frequency = 74.6%). Urinary levels of TCC are reported here for the first time from real-world exposures during pregnancy, showing a median concentration of 0.21 μg/L. Urinary concentrations of TCC correlated well with its phase-I metabolite ∑-2'-hydroxy-TCC (r = 0.49) and the manufacturing byproduct ∑-3'-chloro-TCC C (r = 0.79), and ∑-2'-hydroxy-TCC correlated strongly with ∑-3'-hydroxy-TCC (r = 0.99). This human biomonitoring study presents the first body burden data for TCC from exposures

  18. Profound perturbation induced by triclosan exposure in mouse gut microbiome: a less resilient microbial community with elevated antibiotic and metal resistomes.

    Science.gov (United States)

    Gao, Bei; Tu, Pengcheng; Bian, Xiaoming; Chi, Liang; Ru, Hongyu; Lu, Kun

    2017-06-12

    Environmental chemical-induced perturbations of gut microbiome are associated with a series of adverse health outcomes. The effects of triclosan on human health have been controversial in recent years. The purpose of this study is to investigate the functional impact of triclosan on the mouse gut microbiome and the link between triclosan exposure and resistomes in gut bacteria. We combined 16S rRNA gene sequencing and shotgun metagenomics sequencing to examine the compositional and functional impact of triclosan exposure on the gut microbiota of C57BL/6 mice. 16S rRNA sequencing results revealed that 13-week triclosan exposure in drinking water induced significant perturbations in mouse gut bacterial assemblages with distinct trajectories compared to controls. Metagenomics sequencing results indicated a remarkable enrichment of gut bacterial genes related to triclosan resistance, stress response, antibiotic resistance and heavy metal resistance. Triclosan exposure has a profound impact on the mouse gut microbiome by inducing perturbations at both compositional and functional levels. To our best knowledge, this is the first evidence regarding the functional alterations of gut microbiome induced by triclosan exposure, which may provide novel mechanistic insights into triclosan exposure and associated diseases.

  19. Comparative study of bactericidal activities, postantibiotic effects, and effects of bacterial virulence of penicillin G and six macrolides against Streptococcus pneumoniae.

    Science.gov (United States)

    Fuursted, K; Knudsen, J D; Petersen, M B; Poulsen, R L; Rehm, D

    1997-04-01

    In this report, we present MIC, bactericidal activity, postantibiotic effect (PAE), and in vivo infectivity data for postantibiotic-phase pneumococci. We compared and evaluated penicillin G and six macrolides, erythromycin, azithromycin, clarithromycin, dirithromycin, roxithromycin, and spiramycin, against 10 strains of pneumococci with various levels of susceptibility to penicillin. All of the agents, except azithromycin, exhibited a bactericidal effect (a > or = 3 log10 decrease in the number of CFU per milliliter) after 4 h of exposure to a concentration equal to 10 times the MIC, displaying the following hierarchy: spiramycin = penicillin G = erythromycin = dirithromycin = clarithromycin = roxithromycin > azithromycin. The bactericidal rate of penicillin G was significantly lower for resistant strains (MIC, > or = 2 microg/ml), while bactericidal rates of macrolides were unaffected by penicillin susceptibility. A PAE was induced in all of the strains by all of the antibiotics after exposure for 1 h to a concentration equivalent to 10 times the MIC. The mean duration of PAEs varied between 2.3 and 3.9 h, showing the following hierarchy: spiramycin = dirithromycin = clarithromycin = erythromycin = roxithromycin > azithromycin > penicillin G. Virulence studies were performed with immunocompetent mice by intraperitoneal inoculation of virulent, penicillin-susceptible serotype 3 pneumococci which had been pre-exposed to penicillin G or a macrolide for 1 h. A significant decrease in the virulence of postantibiotic-phase pneumococci was induced only by erythromycin, azithromycin, dirithromycin, and spiramycin, displaying 5.9-, 7.1-, 4.2-, and 3.6-fold increases in the 50% lethal dose (LD50) compared to a control suspension, respectively. No significant correlation could be demonstrated between the LD50 and the MIC, bactericidal activity, or PAE duration. These results suggest that antimicrobial interaction with host defenses in terms of virulence might be a

  20. Bactericidal and cytotoxic effects of Erythrina fusca leaves aquadest extract

    Directory of Open Access Journals (Sweden)

    Janti Sudiono

    2013-03-01

    Full Text Available Background: Empirically, Erythrina fusca has been used as traditional herb for its antibacterial and antiinflammation properties. Periodontal disease is one of the most oral infectious diseases with microorganism predominated as the contributing factors. Porphyromonas gingivalis (P. gingivalis is one of the main bacteria pathogen found in periodontal diseases. Purpose: The purpose of this study was to examine the bactericidal effect of Erythrina fusca Leaves Aquadest Extract (EFLAE at various concentrations on P. gingivalis and cytotoxic effect on fibroblast. Methods: Pure P. gingivalis was cultured in Brain Heart Infusion (BHI medium for 24 hours with or without various concentrations of treatment of EFLAE. Calculation and statistical analysis of remaining bacteria were performed by inhibitory zone method to evaluate the EFLAE bactericidal effect and compared to chlorhexidine as positive control. To evaluate the cytotoxic effect, NIH 3T3 cells were cultured in Dulbecco’s Modification of Eagle’s Medium (DMEM containing of 10% fetal bovine serum (FBS and 1% penicillin-streptomycin, pH 7.2, in 5% CO2, and stored in humidified incubator under temperature 370 C. Cells were treated with/without various concentrations of EFLAE for 48 hours. The viable cells were then counted using 3-(4,5- Dimethylthiazol-2-yl-2,5 diphenyl tetrazodium bromide (MTT method. Results: EFLAE have bactericidal effect on P. gingivalis in a concentration dependent manner starting from 78%. The concentration of 90% EFLAE had stronger bactericidal effect (35.004 ± 1.546 than those of chlorhexidine as positive control (32.313 ± 1.619. One-way ANOVA showed significant bactericidal effect differences among concentrations of EFLAE and chlorhexidine (p<0.05 while Tuckey HSD test showed significant difference only between lower concentration of EFLAE (78%, 79% and chlorhexidine. With the highest concentration of EFLAE (100% applied in the bactericidal test, no cytotoxic effect

  1. [Bactericidal activity of serum and chemotherapy in sensitive and resistant exciter (author's transl)].

    Science.gov (United States)

    Eyer, H; Metz, H; Preac-Mursic, V

    1975-11-21

    Comparing examinations with Ampicillin sensitive and resistant bacteria-strains show that the bactericidal activity of serum is dependent on the bacteria-strains, on the Ampicillin sensitivity of the particular exciter and on the number of bacteria/ml (germ count). Bactericide effect could always be obtained with sensitive strains as a result of additional chemotherapy. With several resistant strains a bactericide effect could not be obtained in this case the continuous optimal Ampicillin addition was the decisive factor. Because of the extremely complicated process of the bactericide one should not make general conclusions from the individual experimental results.

  2. Occurrence and distribution of triclosan in the German Bight (North Sea)

    Energy Technology Data Exchange (ETDEWEB)

    Xie Zhiyong [GKSS Research Centre Geesthacht, Institute for Coastal Research, Max-Planck Strasse 1, D-21502 Geesthacht (Germany); Institute of Ecology and Environmental Chemistry, University of Lueneburg, Scharnhorststrasse 1, D-21335 Lueneburg (Germany)], E-mail: zhiyong.xie@gkss.de; Ebinghaus, Ralf; Floeser, Goetz; Caba, Armando [GKSS Research Centre Geesthacht, Institute for Coastal Research, Max-Planck Strasse 1, D-21502 Geesthacht (Germany); Ruck, Wolfgang [Institute of Ecology and Environmental Chemistry, University of Lueneburg, Scharnhorststrasse 1, D-21335 Lueneburg (Germany)

    2008-12-15

    The potential of triclosan (TCS) acting as an endocrine disruptor has led to growing concern about the presence of TCS in the environment. In this study, seawater samples were collected from the German Bight during sampling campaigns conducted with the German research ships Gauss and Ludwig Prandtl. TCS was determined both in the dissolved phase and in the suspended particulate matters with concentrations ranging 0.8-6870 pg L{sup -1} and <1-95 pg L{sup -1}, respectively. High concentrations of TCS were present in the estuaries of the Elbe and the Weser, indicating significant input of TCS by the river discharge. The correlation coefficient (R{sup 2}) between the dissolved concentration and salinity was 0.79 for the data obtained from the Gauss cruise, showing an obvious declining trend from the coast to the open sea. - Investigation with coastal survey reveals distribution of triclosan in marine waters.

  3. Bactericidal activity of Pistacia lentiscus mastic gum against Helicobacter pylori.

    Science.gov (United States)

    Marone, P; Bono, L; Leone, E; Bona, S; Carretto, E; Perversi, L

    2001-12-01

    In this study we evaluated the antibacterial activity of mastic gum, a resin obtained from the Pistacia lentiscus tree, against clinical isolates of Helicobacter pylori. The minimal bactericidal concentrations (MBCs) were obtained by a microdilution assay. Mastic gum killed 50% of the strains tested at a concentration of 125 microg/ml and 90% at a concentration of 500 microg/ml. The influence of sub-MBCs of mastic gum on the morphologies of H. pylori was evaluated by transmission electron microscopy. The lentiscus resin induced blebbing, morphological abnormalities and cellular fragmentation in H. pylori cells.

  4. High-level tolerance to triclosan may play a role in Pseudomonas aeruginosa antibiotic resistance in immunocompromised hosts: evidence from outbreak investigation

    Directory of Open Access Journals (Sweden)

    D'Arezzo Silvia

    2012-01-01

    Full Text Available Abstract Background and methods Pseudomonas aeruginosa is a major infectious threat to immunocompromised patients. We recently reported a fatal epidemic of multidrug-resistant P. aeruginosa in an onchoematology unit, linked to massive contamination of a triclosan-based disinfectant. The aim of this study is to evaluate the antimicrobial activity of triclosan and chlorhexidine digluconate against the epidemic strain of P. aeruginosa, to confirm the hypothesis that the soap dispenser acted as a continuous source of the infection during the outbreak, and to explore the potential role of triclosan in increasing the level of resistance to selected antibiotics. Susceptibility tests and time-kill assays for disinfectans were performed using two commercial formulations containing triclosan and chlorhexidine digluconate, respectively. Antibiotic susceptibility testing was performed by the broth microdilution method. Findings The P. aeruginosa epidemic strain exhibited an extremely high level of triclosan resistance (apparent MIC = 2,125 mg/L, while it was markedly susceptible to chlorhexidine digluconate (apparent MIC = 12.5 mg/L. Upon gradual adaptation to triclosan, the epidemic strain survived for a long period (> 120 h in the presence of 3,400 mg/L (equivalent to 1.6 × MIC of triclosan, concomitantly increasing the resistance to six antibiotics that are typical substrates of drug efflux pumps of the resistance nodulation division family. This effect was reversed by efflux pump inhibitors. Conclusions The epidemic P. aeruginosa strain was resistant to triclosan and its previous exposure to triclosan increases antibiotic resistance, likely through active efflux mechanisms. Since P. aeruginosa can become tolerant to elevated triclosan concentrations, the use of triclosan-based disinfectants should be avoided in those healthcare settings hosting patients at high risk for P. aeruginosa infection.

  5. Dissipation of triclosan, triclocarban, carbamazepine and naproxen in agricultural soil following surface or sub-surface application of dewatered municipal biosolids

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rajab, Abdul Jabbar; Sabourin, Lyne [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Lapen, David R. [Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6 (Canada); Topp, Edward, E-mail: ed.topp@agr.gc.ca [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Department of Biology, Western University, London, ON N6A 5B7 (Canada)

    2015-04-15

    In many jurisdictions land application of municipal biosolids is a valued source of nutrients for crop production. The practice must be managed to ensure that crops and adjacent water are not subject to contamination by pharmaceuticals or other organic contaminants. The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC), the anti-epileptic drug carbamazepine (CBZ), and the nonsteroidal anti-inflammatory drug naproxen (NAP) are widely used and are carried in biosolids. In the present study, the effect of biosolids and depth of placement in the soil profile on the rates of TCS, TCC, CBZ, and NAP dissipation were evaluated under semi-field conditions. Aggregates of dewatered municipal biosolids (DMBs) supplemented with {sup 14}C-labeled residues were applied either on the soil surface or in the subsurface of the soil profile, and incubated over several months under ambient outdoor conditions. The dissipation of TCS, TCC and NAP was significantly faster in sub-surface than surface applied biosolid aggregates. In contrast the dissipation rate for CBZ was the same in surface applied and incorporated aggregates. Overall, the present study has determined a significant effect of depth of placement on the dissipation rate of biodegradable molecules. - Highlights: • We characterized the soil fate of four organic contaminants carried in biosolids. • Biosolids were placed on the soil surface or incorporated within the soil profile. • Naproxen, triclosan and triclocarban were dissipated more rapidly when incorporated. • Depth of placement did not influence the rate of carbamazepine dissipation. • Soil incorporation of biosolids will result in more rapid dissipation of contaminants.

  6. Use the Extended Activated Sludge Process to Remove Triclosan (TCS) from Wastewater Treatment Plant

    OpenAIRE

    MAROOF, Mostafa Maan; UYSAL, Yağmur

    2015-01-01

    The antibacterial personal care product Triclosan (TCS), is a broad spectrum antibacterial. It has been used for more than 40 years as an antiseptic, disinfectant or preservative in clinical settings, and in the various consumer products including cosmetics, plastic materials and toys. It has lately been determined in the sources of the aquatic environment; its potential effect on ecosystems. The contaminants can reach the soil and aquatic environment through land application of wastewater ef...

  7. Functional characterization of triclosan-resistant enoyl-acyl-carrier protein reductase (FabV in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Yong-Heng Huang

    2016-11-01

    Full Text Available Pseudomonas aeruginosa is extremely resistant to triclosan. Previous studies have shown that P. aeruginosa encodes a triclosan-resistant enoyl-acyl-carrier protein reductase (ENR, FabV, and that deletion of fabV causes P. aeruginosa to be extremely sensitive to triclosan. In this report, we complemented a P. aeruginosa fabV deletion strain with several triclosan-resistant ENR encoding genes, including Vibrio cholera fabV, Bacillus subtilis fabL and Enterococcus faecalis fabK. All complemented strains restored triclosan resistance to the level of the wild-type strain, which confirmed that triclosan-resistant ENR allows P. aeruginosa to be extremely resistant to triclosan. Moreover, fabV exhibits pleiotropic effects. Deletion of fabV led P. aeruginosa to show attenuated swarming motility, decreased rhamnolipid, pyoverdine and acylhomoserine lactones (AHLs production. Complementation of the fabV mutant with any one ENR encoding gene could restore these features to some extent, in comparison with the wild-type strain. Furthermore, we found that addition of exogenous AHLs could restore to the fabV mutant strain the ability to swarm on semisolid plates and to produce more virulence factors than the fabV mutant strain. These findings indicate that deletion of fabV reduced the activity of ENR in P. aeruginosa, decreased fatty acid synthesis, and subsequently depressed the production of AHLs and other virulence factors, which finally may led to a reduction in the pathogenicity of P. aeruginosa. Therefore, fabV should be an ideal target for the control of P. aeruginosa infectivity.

  8. Functional Characterization of Triclosan-Resistant Enoyl-acyl-carrier Protein Reductase (FabV) in Pseudomonas aeruginosa

    Science.gov (United States)

    Huang, Yong-Heng; Lin, Jin-Shui; Ma, Jin-Cheng; Wang, Hai-Hong

    2016-01-01

    Pseudomonas aeruginosa is extremely resistant to triclosan. Previous studies have shown that P. aeruginosa encodes a triclosan-resistant enoyl-acyl-carrier protein reductase (ENR), FabV, and that deletion of fabV causes P. aeruginosa to be extremely sensitive to triclosan. In this report, we complemented a P. aeruginosa fabV deletion strain with several triclosan-resistant ENR encoding genes, including Vibrio cholerae fabV, Bacillus subtilis fabL and Enterococcus faecalis fabK. All complemented strains restored triclosan resistance to the level of the wild-type strain, which confirmed that triclosan-resistant ENR allows P. aeruginosa to be extremely resistant to triclosan. Moreover, fabV exhibits pleiotropic effects. Deletion of fabV led P. aeruginosa to show attenuated swarming motility, decreased rhamnolipid, pyoverdine and acyl-homoserine lactones (AHLs) production. Complementation of the fabV mutant with any one ENR encoding gene could restore these features to some extent, in comparison with the wild-type strain. Furthermore, we found that addition of exogenous AHLs could restore the fabV mutant strain to swarm on semisolid plates and to produce more virulence factors than the fabV mutant strain. These findings indicate that deletion of fabV reduced the activity of ENR in P. aeruginosa, decreased fatty acid synthesis, and subsequently depressed the production of AHLs and other virulence factors, which finally may led to a reduction in the pathogenicity of P. aeruginosa. Therefore, fabV should be an ideal target for the control of P. aeruginosa infectivity. PMID:27965638

  9. Copper and quaternary ammonium cations exert synergistic bactericidal and antibiofilm activity against Pseudomonas aeruginosa.

    Science.gov (United States)

    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

    2008-08-01

    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 Cu(2+) 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 Cu(2+) 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 Cu(2+) and QACs do not interact in aqueous solutions, suggesting that each agent exerts microbiological toxicity through independent biochemical routes. Additionally, Cu(2+) 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 Cu(2+) and QACs are effective combinations of antimicrobials that may be used to kill bacterial biofilms.

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

    Science.gov (United States)

    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

  11. Methyl-triclosan binding to human serum albumin: multi-spectroscopic study and visualized molecular simulation.

    Science.gov (United States)

    Lv, Wenjuan; Chen, Yonglei; Li, Dayong; Chen, Xingguo; Leszczynski, Jerzy

    2013-10-01

    Methyl-triclosan (MTCS), a transformation product and metabolite of triclosan, has been widely spread in environment through the daily use of triclosan which is a commonly used anti-bacterial and anti-fungal substance in consumer products. Once entering human body, MTCS could affect the conformation of human serum albumin (HSA) by forming MTCS-HSA complex and alter function of protein and endocrine in human body. To evaluate the potential toxicity of MTCS, the binding mechanism of HSA with MTCS was investigated by UV-vis absorption, circular dichroism and Fourier transform infrared spectroscopy. Binding constants, thermodynamic parameters, the binding forces and the specific binding site were studied in detail. Binding constant at room tempreture (T = 298K) is 6.32 × 10(3)L mol(-1); ΔH(0), ΔS(0) and ΔG(0) were 22.48 kJ mol(-1), 148.16 J mol(-1)K(-1) and -21.68 kJ mol(-1), respectively. The results showed that the interactions between MTCS and HSA are mainly hydrophobic forces. The effects of MTCS on HSA conformation were also discussed. The binding distance (r = 1.2 nm) for MTCS-HSA system was calculated by the efficiency of fluorescence resonance energy transfer. The visualized binding details were also exhibited by molecular modeling method and the results could agree well with that from the experimental study.

  12. Evaluation of triclosan in Minnesota lakes and rivers: Part II - human health risk assessment.

    Science.gov (United States)

    Yost, Lisa J; Barber, Timothy R; Gentry, P Robinan; Bock, Michael J; Lyndall, Jennifer L; Capdevielle, Marie C; Slezak, Brian P

    2017-08-01

    Triclosan, an antimicrobial compound found in consumer products, has been detected in low concentrations in Minnesota municipal wastewater treatment plant (WWTP) effluent. This assessment evaluates potential health risks for exposure of adults and children to triclosan in Minnesota surface water, sediments, and fish. Potential exposures via fish consumption are considered for recreational or subsistence-level consumers. This assessment uses two chronic oral toxicity benchmarks, which bracket other available toxicity values. The first benchmark is a lower bound on a benchmark dose associated with a 10% risk (BMDL10) of 47mg per kilogram per day (mg/kg-day) for kidney effects in hamsters. This value was identified as the most sensitive endpoint and species in a review by Rodricks et al. (2010) and is used herein to derive an estimated reference dose (RfD(Rodricks)) of 0.47mg/kg-day. The second benchmark is a reference dose (RfD) of 0.047mg/kg-day derived from a no observed adverse effect level (NOAEL) of 10mg/kg-day for hepatic and hematopoietic effects in mice (Minnesota Department of Health [MDH] 2014). Based on conservative assumptions regarding human exposures to triclosan, calculated risk estimates are far below levels of concern. These estimates are likely to overestimate risks for potential receptors, particularly because sample locations were generally biased towards known discharges (i.e., WWTP effluent). Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Mass balance analysis of triclosan, diethyltoluamide, crotamiton and carbamazepine in sewage treatment plants.

    Science.gov (United States)

    Nakada, N; Yasojima, M; Okayasu, Y; Komori, K; Suzuki, Y

    2010-01-01

    The behavior of antibacterial triclosan, insect-repellent diethyltoluamide (DEET), anticonvulsant carbamazepine, and antipruritic crotamiton was investigated at two sewage treatment plants (STPs) to clarify their complete mass balance. Twenty-four-hour flow-proportional composite samples were collected from the influent and effluent of primary and final sedimentation tanks, a biofiltration tank and disinfection tanks. Sludge samples (i.e., activated and excess sludge) and samples of the return flow from the sludge treatment process were collected in the same manner. The analytes in both the dissolved and particulate phases were individually determined by a gas chromatograph equipped with mass spectrometer. Triclosan was dominantly detected in the particulate phase especially in the early stage of treatment (up to 83%) and was efficiently removed (over 90%) in STPs, mainly by sorption to sewage sludge. Limited removal was observed for DEET (55+/-24%), while no significant removal was demonstrated for crotamiton or carbamazepine. The solid-water distribution coefficients (K(d), n=4) for triclosan (log K(d): 3.7-5.1), DEET (1.3-1.9) and crotamiton (1.1-1.6) in the sludge samples are also determined in this study. These findings indicate the limitations of current sewage treatment techniques for the removal of these water-soluble drugs (i.e. DEET, carbamazepine, and crotamiton).

  14. GC-MS analysis and ecotoxicological risk assessment of triclosan, carbamazepine and parabens in Indian rivers.

    Science.gov (United States)

    Ramaswamy, Babu Rajendran; Shanmugam, Govindaraj; Velu, Geetha; Rengarajan, Bhuvaneshwari; Larsson, D G Joakim

    2011-02-28

    Pharmaceutical and personal care products are used extensively worldwide and their residues are frequently reported in aquatic environments. In this study, antiepileptic, antimicrobial and preservative compounds were analyzed in surface water and sediment from the Kaveri, Vellar and Tamiraparani rivers, and in the Pichavaram mangrove in India by gas chromatography-mass spectrometry (GC-MS). The mean concentration of carbamazepine recorded in the Kaveri River water (28.3 ng/L) was higher than in the other rivers and the mangrove. Because carbamazepine is used only in human drugs, this may reflect the relative contributions of human excretions/sewage in these rivers. The mean triclosan level in the Tamiraparani River (944 ng/L) was an order of magnitude greater than in the other water systems, and the concentrations at two of the sites reported here (3800-5160 ng/L) are, to our best knowledge, among the highest detected in surface waters. Sediment levels were, however, comparable with other sites. We conclude that industrial releases are likely major contributors of triclosan into this river system. Among parabens, ethyl paraben was predominantly observed. Hazard Quotients suggest greater environmental risks for triclosan than for carbamazepine and parabens. This is the first study on antiepileptic, antimicrobial and preservatives in rivers and mangroves from India.

  15. Bactericidal Property of the Benzalkonium Chloride in Industrial Circulating Water%洁儿灭在工业循环水中的杀菌性能研究

    Institute of Scientific and Technical Information of China (English)

    孙彩霞; 陈燕敏; 吴晋英; 黄长山

    2016-01-01

    In the thesis,the bactericidal property of benzalkonium chloride was tested by the method of plate counting. The bactericidal effciency was improved with increasing the concentration of benzalkonium chloride. At the same time the bacterial agent which prepared by the benzalkonium chloride had a better scale inbibtion effect , and could be sately applied to industrial circulating water pipeline system.%通过平板计数法考察了不同浓度的洁儿灭对工业循环水中异养菌的杀菌性能,结果显示,洁儿灭杀菌效率随着浓度的增加而增加,且由洁儿灭配制而成的杀菌剂阻垢性能较好,能安全地应用到工业循环水管道系统中。

  16. Serum Bactericidal Assay: New Role in Salmonella Detection.

    Science.gov (United States)

    Chen, Yu; Wu, Da; Sun, Min; Deng, Mingjun; Cui, Shuhua; Liang, Chengzhu; Geng, Juan; Sun, Tao; Long, Ling; Xiao, Xizhi

    2016-01-01

    While inspecting animal feed for Salmonella contamination, we routinely observed bacterial colonies on selective agars that were similar in appearance to those formed by Salmonella. These were identified as Citrobacter freundii, Proteus mirabilis, and Serratia fonticola using biochemical and serological techniques. Because the presence of these bacterial species confounds identification of Salmonella, we refer to them as "interference bacteria." Polyvalent antisera against these interference bacteria were prepared by immunizing rabbits with a mixture of all three organisms. To minimize or eliminate interference by these bacteria, the polyvalent antisera were introduced between the steps of selective enrichment and Salmonella-selective plating. The antisera raised against the interference bacteria, when combined with neonatal rabbit complement, exhibited specific bactericidal activity against C. freundii, P. mirabilis, and S. fonticola. The respective serum bactericidal assay titers were 2(9), 2(8), and 2(10). In selective broth, polyvalent antisera could also kill the target bacterial cells effectively. We tested 526 samples (186 white fishmeal, 97 red fishmeal, and 243 cattle bone powder) using the polyvalent antisera and found that the rates of contamination of each species of the three respective foods decreased by 58.8, 100, and 83%. Our data indicates that polyvalent sera against C. freundii, P. mirabilis, and S. fonticola can be used as inhibitors to increase the accuracy of Salmonella detection.

  17. Bactericidal behavior of Cu-containing stainless steel surfaces

    Science.gov (United States)

    Zhang, Xiangyu; Huang, Xiaobo; Ma, Yong; Lin, Naiming; Fan, Ailan; Tang, Bin

    2012-10-01

    Stainless steels are one of the most common materials used in health care environments. However, the lack of antibacterial advantage has limited their use in practical application. In this paper, antibacterial stainless steel surfaces with different Cu contents have been prepared by plasma surface alloying technology (PSAT). The steel surface with Cu content 90 wt.% (Cu-SS) exhibits strong bactericidal activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) within 3 h. Although the Cu-containing surface with Cu content 2.5 wt.% (CuNi-SS) can also kill all tested bacteria, this process needs 12 h. SEM observation of the bacterial morphology and an agarose gel electrophoresis were performed to study the antibacterial mechanism of Cu-containing stainless steel surfaces against E. coli. The results indicated that Cu ions are released when the Cu-containing surfaces are in contact with bacterial and disrupt the cell membranes, killing the bacteria. The toxicity of Cu-alloyed surfaces does not cause damage to the bacterial DNA. These results provide a scientific explanation for the antimicrobial applications of Cu-containing stainless steel. The surfaces with different antibacterial abilities could be used as hygienic surfaces in healthcare-associated settings according to the diverse requirement of bactericidal activities.

  18. The bactericidal activity of glutaraldehyde-impregnated polyurethane.

    Science.gov (United States)

    Sehmi, Sandeep K; Allan, Elaine; MacRobert, Alexander J; Parkin, Ivan

    2016-10-01

    Although glutaraldehyde is known to be bactericidal in solution, its potential use to create novel antibacterial polymers suitable for use in healthcare environments has not been evaluated. Here, novel materials were prepared in which glutaraldehyde was either incorporated into polyurethane using a simple "swell-encapsulation-shrink" method (hereafter referred to as "glutaraldehyde-impregnated polyurethane"), or simply applied to the polymer surface (hereafter referred to as "glutaraldehyde-coated polyurethane"). The antibacterial activity of glutaraldehyde-impregnated and glutaraldehyde-coated polyurethane samples was tested against Escherichia coli and Staphylococcus aureus. Glutaraldehyde-impregnated polyurethane resulted in a 99.9% reduction in the numbers of E. coli within 2 h and a similar reduction of S. aureus within 1 h, whereas only a minimal reduction in bacterial numbers was observed when the biocide was bound to the polymer surface. After 15 days, however, the bactericidal activity of the impregnated material was substantially reduced presumably due to polymerization of glutaraldehyde. Thus, although glutaraldehyde retains antibacterial activity when impregnated into polyurethane, activity is not maintained for extended periods of time. Future work should examine the potential of chemical modification of glutaraldehyde and/or polyurethane to improve the useful lifespan of this novel antibacterial polymer. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  19. Crosstalk between circadian rhythmicity, mitochondrial dynamics and macrophage bactericidal activity

    Science.gov (United States)

    Oliva-Ramírez, Jacqueline; Moreno-Altamirano, María Maximina B; Pineda-Olvera, Benjamín; Cauich-Sánchez, Patricia; Sánchez-García, F Javier

    2014-01-01

    Biological functions show rhythmic fluctuations with 24-hr periodicity regulated by circadian proteins encoded by the so-called ‘clock’ genes. The absence or deregulation of circadian proteins in mice leads to metabolic disorders and in vitro models have shown that the synthesis of pro-inflammatory cytokines by macrophages follows a circadian rhythm so showing a link between circadian rhythmicity, metabolism and immunity. Recent evidence reveals that mitochondrial shape, position and size, collectively referred to as mitochondrial dynamics, are related to both cell metabolism and immune function. However, studies addressing the simultaneous crosstalk between circadian rhythm, mitochondrial dynamics and cell immune function are scarce. Here, by using an in vitro model of synchronized murine peritoneal macrophages, we present evidence that the mitochondrial dynamics and the mitochondrial membrane potential (Δψm) follow a circadian rhythmic pattern. In addition, it is shown that the fusion of mitochondria along with high Δψm, indicative of high mitochondrial activity, precede the highest phagocytic and bactericidal activity of macrophages on Salmonella typhimurium. Taken together, our results suggest a timely coordination between circadian rhythmicity, mitochondrial dynamics, and the bactericidal capacity of macrophages. PMID:24903615

  20. Phosphorylcholine allows for evasion of bactericidal antibody by Haemophilus influenzae.

    Directory of Open Access Journals (Sweden)

    Sarah E Clark

    Full Text Available The human pathogen Haemophilus influenzae has the ability to quickly adapt to different host environments through phase variation of multiple structures on its lipooligosaccharide (LPS, including phosphorylcholine (ChoP. During colonization with H. influenzae, there is a selection for ChoP+ phase variants. In a murine model of nasopharyngeal colonization, this selection is lost in the absence of adaptive immunity. Based on previous data highlighting the importance of natural antibody in limiting H. influenzae colonization, the effect of ChoP expression on antibody binding and its bactericidal activity was investigated. Flow cytometric analysis revealed that ChoP+ phase variants had decreased binding of antibody to LPS epitopes compared to ChoP- phase variants. This difference in antibody binding correlated with increased survival of ChoP+ phase variants in the presence of antibody-dependent, complement-mediated killing. ChoP+ phase variants were also more resistant to trypsin digestion, suggesting a general effect on the physical properties of the outer membrane. Moreover, ChoP-mediated protection against antibody binding correlated with increased resilience of outer membrane integrity. Collectively, these data suggest that ChoP expression provides a selective advantage during colonization through ChoP-mediated effects on the accessibility of bactericidal antibody to the cell surface.

  1. Algerian propolis extracts: Chemical composition, bactericidal activity and in vitro effects on gilthead seabream innate immune responses.

    Science.gov (United States)

    Soltani, El-Khamsa; Cerezuela, Rebeca; Charef, Noureddine; Mezaache-Aichour, Samia; Esteban, Maria Angeles; Zerroug, Mohamed Mihoub

    2017-03-01

    Propolis has been used as a medicinal agent for centuries. The chemical composition of four propolis samples collected from four locations of the Sétif region, Algeria, using gas chromatography-mass spectrometry was determined. More than 20 compounds and from 30 to 35 compounds were identified in the aqueous and ethanolic extracts, respectively. Furthermore, the antimicrobial activity of the propolis extracts against two marine pathogenic bacteria was evaluated. Finally, the in vitro effects of propolis on gilthead seabream (Sparus aurata L.) leucocyte activities were measured. The bactericidal activity of ethanolic extracts was very high against Shewanella putrefaciens, average against Photobacterium damselae and very low against Vibrio harveyi. The lowest bactericidal activity was always that found for the aqueous extracts. When the viability of gilthead seabream head-kidney leucocytes was measured after 30 min' incubation with the different extracts, both the ethanolic and aqueous extracts of one of the propolis samples (from Babor) and the aqueous extract of another (from Ain-Abbassa) provoked a significant decrease in cell viability when used at concentrations of 100 and 200 μg ml(-1). Furthermore, significant inhibitory effects were recorded on leucocyte respiratory burst activity when isolated leucocytes where preincubated with the extracts. This effect was dose-dependent in all cases except when extracts from a third propolis sample (from Boutaleb) were used. Our findings suggest that some of Algerian propolis extracts have bactericidal activity against important bacterial pathogens in seabream and significantly modulate in vitro leucocyte activities, confirming their potential as a source of new natural biocides and/or immunomodulators in aquaculture practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Short-term exposure to triclosan decreases thyroxine in vivo via upregulation of hepatic catabolism in young long-evans rats

    Science.gov (United States)

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol)is a chlorinated phenolic antibacterial compound used in consumer products. Structural similarity of triclosan to thyroid hormones, in vitro activation ofthe human pregnane X receptor (PXR) and induction of hepatic Phase I enzymes...

  3. Ten-year trends in urinary concentrations of triclosan and benzophenone-3 in the general U.S. population from 2003 to 2012.

    Science.gov (United States)

    Han, Changwoo; Lim, Youn-Hee; Hong, Yun-Chul

    2016-01-01

    Despite their popular use and emerging evidences of adverse health effects, consequent trends in population level triclosan and benzophenone-3 exposure have been poorly evaluated. Therefore, we examined temporal trends of urinary triclosan and benzophenone-3 concentration in the general U.S. population by combining five cycles of National Health and Nutritional Examination Survey (NHANES, 2003-2012) data. We calculated percent changes and the least square geometric means (LSGMs) of urinary triclosan and benzophenone-3 concentration from 10,232 participants by using multivariable regression models. As a result, LSGM concentration of urinary triclosan and benzophenone-3 did not show statistically significant changes over the study period. [Percent change (95% CI): Triclosan, -7.35% (-20.86, 8.47); Benzophenone-3, 7.08% (-27.88, 58.99)] However, we found decreasing trend of urinary triclosan concentration and increasing trend of urinary benzophenone-3 concentration since 2005-2006. Socio-demographic factors which affected urinary concentration of triclosan and benzophenone-3 persisted throughout 10 year study period. Highest income group showed higher level of urinary triclosan and benzophenone-3 concentration. Overall concentration of benzophenone-3 was higher in female than in male, and higher in non-Hispanic Whites than any other races/ethnicities.

  4. TRICLOSAN MONITORING OF WASTEWATER AND RIVER WATER SAMPLES FROM THE NORTHEAST OF SPAIN AND THE MIDWEST USA BY ELISA AND GC/MS

    Science.gov (United States)

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is a broad spectrum antibacterial that is incorporated into numerous household products such as soaps, deodorants, toothpastes, toys, bedding, socks, and trash bags to decrease bacterial contamination. Triclosan is structurally similar to environmen...

  5. In situ photoproduction of dichlorodibenzo- p-dioxin from non-ionic triclosan isolated in solid argon

    Science.gov (United States)

    Kuş, Nihal; Reva, Igor; Bayarı, Sevgi; Fausto, Rui

    2012-01-01

    The infrared spectrum of triclosan [or 5-chloro-2-(2,4-dichlorophenoxy)phenol] isolated in a low temperature (˜15 K) argon matrix has been recorded and assigned with help of DFT claculations undertaken with the B3LYP functional and the 6-311++G(d,p) basis set. The obtained spectrum doubtlessly exhibits the characteristic vibrational signature of the neutral (phenol) form of the compound, which exists in two different conformations (forms I and II) in the matrix, in a I: II population ratio of ca. 0.75. Upon broadband UV irradiation of the matrix-isolated triclosan with unfiltered light provided by a xenon arc lamp, formation of 2,8-dichlorodibenzo- p-dioxin (2,8-DCDD) was observed, together with HCl. The reaction seems to occur through initial photoproduction of the triclosan phenol radical derivative, and involve in the initial step participation of dissociative (πσ ∗) excited states along the OH stretching coordinate, as observed previously for other phenol derivatives. The photochemically detached hydrogen atom derived from triclosan may then react with the closest located chlorine atom in the triclosan molecule to yield HCl and a biradical species, which can subsequently undergo a ring-closure reaction by intramolecular recombination, leading to the observed 2,8-DCDD.

  6. Mucoadhesive, triclosan-loaded polymer microspheres for application to the oral cavity: preparation and controlled release characteristics.

    Science.gov (United States)

    Kockisch, Sandra; Rees, Gareth D; Tsibouklis, John; Smart, John D

    2005-01-01

    The aim of this study was to develop mucoadhesive microspheres that can be utilised for the controlled release of triclosan in oral-care formulations, specifically dental pastes. Using a double-emulsion solvent evaporation technique, triclosan was incorporated into microspheres that were prepared from Gantreztrade mark MS-955, Carbopol 974P, polycarbophil or chitosan and the profiles for its release were established under simulated 'in use' conditions. Triclosan was rapidly released into a sodium lauryl sulphate containing buffer from all but the chitosan microspheres. The release of triclosan from microspheres suspended in a non-aqueous paste, was found to be sustained over considerable time-periods, which were influenced strongly by the nature of the polymeric carrier. For microspheres that were fabricated from Gantrez, Carbopol or polycarbophil, the release appeared to obey zero-order kinetics whereas in the case of chitosan-derived vehicles, the release profile fitted the Baker and Lonsdale model. The work has demonstrated that these polymeric microspheres, particularly those of chitosan, are promising candidates for the sustained release of triclosan in the oral cavity.

  7. Bactericidal antibody response to Pseudomonas aeruginosa by adults with urinary tract infections.

    Science.gov (United States)

    Smalley, D L; Ourth, D D

    1979-01-01

    In this investigation we found that adults with upper urinary tract infections caused by Pseudomonas aeruginosa produced serum antibodies with bactericidal activity against the bacterium. Seventeen of 20 infected adults showed bactericidal activity with a titer range of 1:10 to 1:10,000. PMID:117024

  8. Staphylococcus aureus but not Listeria monocytogenes adapt to triclosan and adaptation correlates with increased fabI expression and agr deficiency

    DEFF Research Database (Denmark)

    Nielsen, Lene Nørby; Larsen, Marianne Halberg; Skovgaard, Sissel

    2013-01-01

    Background. The ability of pathogens to adapt to the widely used biocide, triclosan, varies substantially. The purpose of the study was to examine bacterial adaptation over an extended period of time to low increments of triclosan concentrations. Focus was two human pathogens, S. aureus and L....... monocytogenes that previously have displayed inherent high and low adaptability, respectively. Results. Three strains of L. monocytogenes and two strains of S. aureus including the community-acquired USA300 were exposed to increasing, sub-lethal concentrations of triclosan in triclosan-containing agar gradients....... Following 25 days of exposure on agar plates to sub-lethal concentrations of triclosan with a twofold concentration increase every second day, minimum inhibitory concentration (MIC) for S. aureus increased from 0.125 (8325-4) and 0.0625 (USA 300) mg/L to 4 mg/L. The MIC of all three L. monocytogenes strains...

  9. Passive dosing of triclosan in multi-generation tests with copepods - Stable exposure concentrations and effects at the low µg l-1 range

    DEFF Research Database (Denmark)

    Ribbenstedt, Anton; Mustajärvi, Lukas; Breitholtz, Magnus

    2017-01-01

    to test the applicability of passive dosing to maintain stable concentrations of the organochlorine bacteriocide triclosan in the water phase during a 6-week multi-generation population development test with the harpacticoid copepod Nitocra spinipes. Triclosan was loaded into silicone (1000 mg), which...... was used as passive dosing phase in the exposure vials. The distribution ratio for triclosan between silicone and water (Dsilicone-water ) was 10466 ± 1927. A population development test was conducted at three concentration levels of triclosan that were measured to be 3-5 µg L(-1) , 7-11 µg L(-1) and 16...... exerted on juvenile development. Progressively lower development index values in the populations exposed to increasing triclosan concentrations suggest developmental retardation. Our results further stress the need for chronic exposure during ecotoxicity testing in chemical risk assessment as even...

  10. Passive dosing of triclosan in multi-generation tests with copepods - Stable exposure concentrations and effects at the low µg l-1 range

    DEFF Research Database (Denmark)

    Ribbenstedt, Anton; Mustajärvi, Lukas; Breitholtz, Magnus;

    2016-01-01

    to test the applicability of passive dosing to maintain stable concentrations of the organochlorine bacteriocide triclosan in the water phase during a 6-week multi-generation population development test with the harpacticoid copepod Nitocra spinipes. Triclosan was loaded into silicone (1000 mg), which...... was used as passive dosing phase in the exposure vials. The distribution ratio for triclosan between silicone and water (Dsilicone-water ) was 10466 ± 1927. A population development test was conducted at three concentration levels of triclosan that were measured to be 3-5 µg L(-1) , 7-11 µg L(-1) and 16...... exerted on juvenile development. Progressively lower development index values in the populations exposed to increasing triclosan concentrations suggest developmental retardation. Our results further stress the need for chronic exposure during ecotoxicity testing in chemical risk assessment as even...

  11. Bactericidal Antibiotics Do Not Appear To Cause Oxidative Stress in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Feld, Louise; Knudsen, Gitte Maegaard; Gram, Lone

    2012-01-01

    self-destruction by internal production of hydroxyl radicals. The purpose of the present study was to determine if a similar mechanism is involved in antibiotic killing of the infectious human pathogen, Listeria monocytogenes. We treated wild-type L. monocytogenes and oxidative stress mutants (Δsod......Oxidative stress can be an important contributor to the lethal effect of bactericidal antibiotics in some bacteria, such as Escherichia coli and Staphylococcus aureus. Thus, despite the different target-specific actions of bactericidal antibiotics, they have a common mechanism leading to bacterial...... and Δfri) with three different bactericidal antibiotics and found no difference in killing kinetics. In contrast, wild-type E. coli and an oxidative stress mutant (ΔsodA ΔsodB) differed significantly in their sensitivity to bactericidal antibiotics. We conclude that bactericidal antibiotics did not appear...

  12. In vitro and in vivo bactericidal activity of Vitex negundo leaf extract against diverse multidrug resistant enteric bacterial pathogens

    Institute of Scientific and Technical Information of China (English)

    Muhammad Kamruzzaman; S.M. Nayeemul Bari; Shah M. Faruque

    2013-01-01

    Objective: To investigate in vitro and in vivo antibacterial potentials of Vitex negundo (V. negundo) leaf extracts against diverse enteric pathogens. Methods: Water and methanol extracts of V. negundo leaves were evaluated against enteric bacterial pathogens by using standard disc diffusion, viable bacterial cell count methods, determination of minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC). Results: Methanol extract of V. negundo leaves showed potent antibacterial activity (inhibition zone: 9.9-22.6 mm, MIC:200-3 200 μg/mL, MBC: 200-6 400 μg/mL) against all the pathogenic enteric bacteria (Vibriocholerae , Vibrio parahaemolyticus, Vibrio mimicus, Echerichia coli, Shigella spps., and Aeromonas spps) tested. Methanol extract of V. negundo leaves showed potent bactericidal activity both in vitro laboratory conditions (MBC, 200-400 μg/mL) and in the intestinal environment (Dose, 1-2 mg/mL) of infant mice against pathogenic Vibrio cholerae, the major causative agent of cholera. Furthermore, assays using the mice cholera model showed that V. negundo methanol extract can protect mice from Vibrio cholerae infection and significantly decrease the mortality rate (P<0.0001). Conclusions: For the first time we showed that methanol extract of V. negundo leaves exhibited strong vibriocidal activity both in vitro and in vivo conditions. Therefore, it will be useful to identify and isolate the active compounds of this extract that could be a good alternative of antibiotics to treat cholera.

  13. Anti-biofilm and bactericidal effects of magnolia bark-derived magnolol and honokiol on Streptococcus mutans.

    Science.gov (United States)

    Sakaue, Yuuki; Domon, Hisanori; Oda, Masataka; Takenaka, Shoji; Kubo, Miwa; Fukuyama, Yoshiyasu; Okiji, Takashi; Terao, Yutaka

    2016-01-01

    Dental caries affects people of all ages and is a worldwide health concern. Streptococcus mutans is a major cariogenic bacterium because of its ability to form biofilm and induce an acidic environment. In this study, the antibacterial activities of magnolol and honokiol, the main constituents of the bark of magnolia plants, toward planktonic cell and biofilm of S. mutans were examined and compared with those of chlorhexidine. The minimal inhibitory concentrations of magnolol, honokiol and chlorhexidine for S. mutans were 10, 10 and 0.25 µg/mL, respectively. In addition, each agent showed bactericidal activity against S. mutans planktonic cells and inhibited biofilm formation in a dose- and time-dependent manner. Magnolol (50 µg/mL) had greater bactericidal activity against S. mutans biofilm than honokiol (50 µg/mL) and chlorhexidine (500 µg/mL) at 5 min after exposure, while all showed scant activity against biofilm at 30 s. Furthermore; chlorhexidine (0.5-500 µg/mL) exhibited high cellular toxicity for the gingival epithelial cell line Ca9-22 at 1 hr, whereas magnolol (50 µg/mL) and honokiol (50 µg/mL) did not. Thus; it was found that magnolol has antimicrobial activities against planktonic and biofilm cells of S. mutans. Magnolol may be a candidate for prevention and management of dental caries.

  14. MetQ of Neisseria gonorrhoeae Is a Surface-Expressed Antigen That Elicits Bactericidal and Functional Blocking Antibodies

    Science.gov (United States)

    Semchenko, Evgeny A.; Day, Christopher J.

    2016-01-01

    ABSTRACT Neisseria gonorrhoeae, the causative agent of the sexually transmitted infection (STI) gonorrhea, is a growing public health threat for which a vaccine is urgently needed. We characterized the functional role of the gonococcal MetQ protein, which is the methionine binding component of an ABC transporter system, and assessed its potential as a candidate antigen for inclusion in a gonococcal vaccine. MetQ has been found to be highly conserved in all strains investigated to date, it is localized on the bacterial surface, and it binds l-methionine with a high affinity. MetQ is also involved in gonococcal adherence to cervical epithelial cells. Mutants lacking MetQ have impaired survival in human monocytes, macrophages, and serum. Furthermore, antibodies raised against MetQ are bactericidal and are able to block gonococcal adherence to epithelial cells. These data suggest that MetQ elicits both bactericidal and functional blocking antibodies and is a valid candidate antigen for additional investigation and possible inclusion in a vaccine for prevention of gonorrhea. PMID:27895130

  15. Cytotoxicity and inhibitory effects of low-concentration triclosan on adipogenic differentiation of human mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Li-Wu [Division of Personalized Nutrition and Medicine, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States); Wu, Qiangen [Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States); Green, Bridgett; Nolen, Greg [Division of Personalized Nutrition and Medicine, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States); Shi, Leming [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States); LoSurdo, Jessica [Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 (United States); Deng, Helen [Arkansas Department of Health, Little Rock, AR 72205 (United States); Bauer, Steven [Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 (United States); Fang, Jia-Long, E-mail: jia-long.fang@fda.hhs.gov [Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States); Ning, Baitang, E-mail: baitang.ning@fda.hhs.gov [Division of Personalized Nutrition and Medicine, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States)

    2012-07-15

    Humans at all ages are continually exposed to triclosan (TCS), a widely used antimicrobial agent that can be found in many daily hygiene products, such as toothpastes and shampoos; however, the toxicological and biological effects of TCS in the human body after long-term and low-concentration exposure are far from being well understood. In the current study, we investigated the effects of TCS on the differentiation of human mesenchymal stem cells (hMSCs) by measuring the cytotoxicity, morphological changes, lipid accumulation, and the expression of adipocyte differentiation biomarkers during 21-day adipogenesis. Significant cytotoxicity was observed in un-induced hMSCs treated with high-concentration TCS (≥ 5.0 μM TCS), but not with low-concentration treatments (≤ 2.5 μM TCS). TCS inhibited adipocyte differentiation of hMSCs in a concentration-dependent manner in the 0.156 to 2.5 μM range as indicated by morphological changes with Oil Red O staining, which is an index of lipid accumulation. The inhibitory effect was confirmed by a decrease in gene expression of specific adipocyte differentiation biomarkers including adipocyte protein 2, lipoprotein lipase, and adiponectin. Our study demonstrates that TCS inhibits adipocyte differentiation of hMSCs under concentrations that are not cytotoxic and in the range observed in human blood. -- Highlights: ► TCS is cytotoxic to un-induced hMSCs at concentrations ≥ 5.0 μM. ► TCS at concentrations ≤ 2.5 μM is not cytotoxic to induced hMSCs. ► TCS at non-cytotoxic concentrations inhibits lipid formation in induced hMSCs. ► TCS decreases the expression of specific biomarkers of adipocyte differentiation. ► TCS at concentrations observed in human blood inhibits adipogenesis of hMSCs.

  16. Impact of biosolids on the persistence and dissipation pathways of triclosan and triclocarban in an agricultural soil

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rajab, Abdul Jabbar; Sabourin, Lyne; Scott, Andrew [Agriculture and Agri-Food Canada, London, ON, Canada N5V 4T3 (Canada); Lapen, David R. [Agriculture and Agri-Food Canada, Ottawa, ON, Canada K1A 0C6 (Canada); Topp, Edward, E-mail: ed.topp@agr.gc.ca [Agriculture and Agri-Food Canada, London, ON, Canada N5V 4T3 (Canada)

    2009-11-15

    The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC) are widely used in many personal care products. Knowledge concerning the fate of these two compounds in different environmental matrices is scarce. In this study, the fate of TCS and TCC in soil following direct addition, or when residues were applied via either liquid municipal biosolids (LMB) or dewatered municipal biosolids (DMB) was investigated in laboratory dissipation experiments and under outdoor conditions using radioisotope methods. In laboratory incubations, {sup 14}C-TCC or {sup 14}C-TCS was added to microcosms containing a loam soil and the rate of {sup 14}CO{sub 2} accumulation and loss of solvent-extractable {sup 14}C were determined during incubation at 30 {sup o}C. Compared to when TCC or TCS was added directly to soil, both chemicals were mineralized more rapidly when applied in LMB, and both were mineralized more slowly when applied in DMB. The application matrix had no effect on the rate of removal of extractable residues. In field experiments, parent compounds were incorporated directly in soil, incorporated via LMB, or a single aggregate of amended DMB was applied to the soil surface. During the experiment soil temperatures ranged from 20 {sup o}C to 10 {sup o}C. Dissipation was much slower in the field than in the laboratory experiments. Removal of non-extractable residues was faster in the presence of LMB than the other treatments. Recovery of extractable and non-extractable residues suggested that there was little atmospheric loss of {sup 14}C. Triclocarban readily formed non-extractable residues with DMB whereas TCS did not. Overall, this study has identified that both the pathways and the kinetics of TCS and TCC dissipation in soil are different when the chemicals are carried in biosolids compared to when these chemicals are added directly to the soil.

  17. The effects of a new therapeutic triclosan/copolymer/sodium-fluoride dentifrice on oral bacteria, including odorigenic species.

    Science.gov (United States)

    Furgang, David; Sreenivasan, Prem K; Zhang, Yun Po; Fine, Daniel H; Cummins, Diane

    2003-09-01

    This investigation examined the in vitro and ex vivo antimicrobial effects of a new dentifrice, Colgate Total Advanced Fresh, formulated with triclosan/copolymer/sodium fluoride, on oral bacteria, including those odorigenic bacteria implicated in bad breath. The effects of Colgate Total Advanced Fresh were compared to commercially available fluoride dentifrices that served as controls. Three experimental approaches were undertaken for these studies. In the first approach, the dentifrice formulations were tested in vitro against 13 species of oral bacteria implicated in bad breath. The second approach examined the antimicrobial activity derived from dentifrice that was adsorbed to and released from hydroxyapatite disks. In this approach, dentifrice-treated hydroxyapatite disks were immersed in a suspension of bacteria, and reduction in bacterial viability from the release of bioactive agents from hydroxyapatite was determined. The third approach examined the effect of treating bacteria immediately after their removal from the oral cavity of 11 adult human volunteers. This ex vivo study examined the viability of cultivable oral bacteria after dentifrice treatment for 2 minutes. Antimicrobial effects were determined by plating Colgate Total Advanced Fresh and control-dentifrice-treated samples on enriched media (for all cultivable oral bacteria) and indicator media (for hydrogen-sulfide-producing organisms), respectively. Results indicated that the antimicrobial effects of Colgate Total Advanced Fresh were significantly greater than either of the other dentifrices for all 13 oral odorigenic bacterial strains tested in vitro (P Colgate Total Advanced Fresh-treated hydroxyapatite disks were significantly more active in reducing bacterial growth than the other dentifrices tested (P oral bacteria with Colgate Total Advanced Fresh demonstrated a 90.9% reduction of all oral cultivable bacteria and a 91.5% reduction of oral bacteria producing hydrogen sulfide compared with

  18. Killing of gram-negative bacteria by polymorphonuclear leukocytes: role of an O2-independent bactericidal system.

    Science.gov (United States)

    Weiss, J; Victor, M; Stendhal, O; Elsbach, P

    1982-04-01

    Previous studies have suggested that a cationic bactericidal/permeability-increasing protein (BPI) present in both rabbit and human polymorphonuclear leukocytes is the principal O2-independent bactericidal agent of these cells toward several strains of Escherichia coli and Salmonella typhimurium (1978. J. Biol. Chem. 253: 2664--2672; 1979. J. Biol. Chem. 254: 11000--11009). To further evaluate the possible role of this protein in the killing of gram-negative bacteria by polymorphonuclear leukocytes, we have measured the bactericidal activity of intact rabbit peritoneal exudate leukocytes under aerobic or anaerobic conditions and of intact human leukocytes from a patient with chronic granulomatous disease. Anaerobic conditions were created by flushing the cells under a nitrogen stream. Effective removal of oxygen was demonstrated by the inability of nitrogen-flushed leukocytes to mount a respiratory burst (measured as increased conversion of 1-[14C]glucose leads to 14CO2 or by superoxide production) during bacterial ingestion. At a bacteria/leukocyte ratio of 10:1, killing of gram-positive, BPI-resistant, Staphylococcus epidermidis is markedly impaired in the absence of oxygen (76.4 +/- 3.3% killing in room air, 29.2 +/- 8.2% killing in nitrogen). Essentially all increased bacterial survival is intracellular. In contrast, both a nonopsonized rough strain (MR-10) and an opsonized smooth strain (MS) of S. typhimurium 395 are killed equally well in room air and nitrogen. A maximum of 70--80 MR-10 and 30--40 MS are killed per leukocyte either in the presence or absence of oxygen. There is no intracellular bacterial survival in either condition indicating that intracellular O2-independent bactericidal system(s) of rabbit polymorphonuclear leukocytes can at least match the leukocyte's ingestive capacity. Whole homogenates and crude acid extracts manifest similar bactericidal capacity toward S. typhimurium 395. This activity can be accounted for by the BPI content of these

  19. Multi-omics approach to study global changes in a triclosan-resistant mutant strain of Acinetobacter baumannii ATCC 17978.

    Science.gov (United States)

    Fernando, Dinesh M; Chong, Patrick; Singh, Manu; Spicer, Victor; Unger, Mark; Loewen, Peter C; Westmacott, Garrett; Kumar, Ayush

    2017-01-01

    Acinetobacter baumannii AB042, a triclosan-resistant mutant strain, was examined for modulated gene expression using whole-genome sequencing, transcriptomics and proteomics in order to understand the mechanism of triclosan resistance as well as its impact on A. baumannii. Data revealed modulated expression of the fatty acid metabolism pathway, co-factors known to play a role in the synthesis of fatty acids, as well as several transcriptional regulators. The membrane composition of the mutant revealed a decrease in C18 with a corresponding increase in C16 fatty acids compared with the parent strain A. baumannii ATCC 17978. These data indicate that A. baumannii responds to triclosan by altering the expression of genes involved in fatty acid metabolism, antibiotic resistance and amino acid metabolism.

  20. Bactericidal Antibiotics Increase Hydroxyphenyl Fluorescein Signal by Altering Cell Morphology

    DEFF Research Database (Denmark)

    Paulander, Wilhelm; Wang, Ying; Folkesson, Sven Anders;

    2014-01-01

    It was recently proposed that for bactericidal antibiotics a common killing mechanism contributes to lethality involving indirect stimulation of hydroxyl radical (OH center dot) formation. Flow cytometric detection of OH center dot by hydroxyphenyl fluorescein (HPF) probe oxidation was used...... to support this hypothesis. Here we show that increased HPF signals in antibiotics-exposed bacterial cells are explained by fluorescence associated with increased cell size, and do not reflect reactive oxygen species (ROS) concentration. Independently of antibiotics, increased fluorescence was seen...... for elongated cells expressing the oxidative insensitive green fluorescent protein (GFP). Although our data question the role of ROS in lethality of antibiotics other research approaches point to important interplays between basic bacterial metabolism and antibiotic susceptibility. To underpin...

  1. Bactericidal Antibiotics Increase Hydroxyphenyl Fluorescein Signal by Altering Cell Morphology

    DEFF Research Database (Denmark)

    Paulander, Wilhelm; Wang, Ying; Folkesson, Sven Anders

    2014-01-01

    It was recently proposed that for bactericidal antibiotics a common killing mechanism contributes to lethality involving indirect stimulation of hydroxyl radical (OH center dot) formation. Flow cytometric detection of OH center dot by hydroxyphenyl fluorescein (HPF) probe oxidation was used...... to support this hypothesis. Here we show that increased HPF signals in antibiotics-exposed bacterial cells are explained by fluorescence associated with increased cell size, and do not reflect reactive oxygen species (ROS) concentration. Independently of antibiotics, increased fluorescence was seen...... for elongated cells expressing the oxidative insensitive green fluorescent protein (GFP). Although our data question the role of ROS in lethality of antibiotics other research approaches point to important interplays between basic bacterial metabolism and antibiotic susceptibility. To underpin...

  2. Bactericidal antibiotics increase hydroxyphenyl fluorescein signal by altering cell morphology.

    Directory of Open Access Journals (Sweden)

    Wilhelm Paulander

    Full Text Available It was recently proposed that for bactericidal antibiotics a common killing mechanism contributes to lethality involving indirect stimulation of hydroxyl radical (OH• formation. Flow cytometric detection of OH• by hydroxyphenyl fluorescein (HPF probe oxidation was used to support this hypothesis. Here we show that increased HPF signals in antibiotics-exposed bacterial cells are explained by fluorescence associated with increased cell size, and do not reflect reactive oxygen species (ROS concentration. Independently of antibiotics, increased fluorescence was seen for elongated cells expressing the oxidative insensitive green fluorescent protein (GFP. Although our data question the role of ROS in lethality of antibiotics other research approaches point to important interplays between basic bacterial metabolism and antibiotic susceptibility. To underpin such relationships, methods for detecting bacterial metabolites at a cellular level are needed.

  3. Synergistic bactericidal interaction of josamycin with human neutrophils in vitro.

    Science.gov (United States)

    Labro, M T; el Benna, J

    1990-10-01

    Josamycin and erythromycin have been compared for their in-vitro interaction with bactericidal killing by human neutrophils. The mechanism of this interaction was studied in two ways. First, the target organisms (Staphylococcus aureus and Pseudomonas aeruginosa) were incubated for 60 min with josamycin, erythromycin or control buffer prior to use in a human polymorphonuclear neutrophil (PMN) killing assay. Second the macrolides were added directly to acellular killing systems mimicking those acting inside the phagolysosome; oxygen-independent systems were obtained from a crude granule extract of PMN and oxygen-dependent systems consisted either of a mixture of xanthine plus xanthine oxidase or of a solution of H2O2. Whereas josamycin-pretreated P. aeruginosa were twice as sensitive to killing by PMN than were control cells, this was not the case for S. aureus. Both oxidant generating systems were more effective in destroying S. aureus in the presence of josamycin (3 and 30 mg/l). Erythromycin showed a similar synergy but only with the xanthine plus xanthine oxidase system. This synergy was observed with neither of the O2-independent systems for S. aureus, nor with any acellular system for P. aeruginosa. These data suggest that at least two kinds of mechanism may explain the bactericidal synergy observed between macrolides and PMN. The first (for macrolide-resistant species such as P. aeruginosa) could be due to alterations in the bacteria by the antibiotics, while the second (for macrolide-sensitive species such as S. aureus) could be based upon an as yet unexplained transformation of the molecules by reactive oxygen species into more "toxic" forms. These differences between josamycin and erythromycin could arise from differences in their chemical structure.

  4. Dental adhesives with bioactive and on-demand bactericidal properties.

    Science.gov (United States)

    Welch, Ken; Cai, Yanling; Engqvist, Håkan; Strømme, Maria

    2010-05-01

    The aim of the present work was to perform the first in vitro evaluation of a new interfacial bond-promoting material-and-method concept for on-demand long term bacteria inhibition in dental restoration procedures. The bioactivity, mechanical bonding strength and photocatalytic bactericidal properties, induced by low dose ultraviolet-A (UV-A) irradiation of dental adhesives containing crystalline titania nanoparticles (NPs), were analyzed. Dental adhesives with a NP content of 20wt% were shown to be bioactive in terms of spontaneous hydroxylapatite formation upon storage in simulated body fluid and the bioactivity was found to be promoted by chemical etching of the adhesives. The mechanical bonding strength between the adhesives and a HA tooth model was shown to be unaffected by the NPs up to a NP content of 30wt%. Elimination of Staphylococcus epidermidis in contact with the adhesives was found to depend both on UV photocatalytic irradiation intensity and time. Efficient elimination of the bacteria could be achieved using a UV-A dose of 4.5J/cm(2) which is about 6 times below the safe maximum UV dose according to industry guidelines, and 20 times below the average UV-A dose received during an ordinary sun bed session. The combined features of bioactivity and on-demand bactericidal effect should open up the potential to create dental adhesives that reduce the incidence of secondary caries and promote closure of gaps forming at the interface towards the tooth via remineralization of adjacent tooth substance, as well as prevention of bacterial infections via on-demand UV-A irradiation. 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. Triclosan as a surrogate for household biocides: an investigation into biocides in aquatic environments of a highly urbanized region.

    Science.gov (United States)

    Chen, Zhi-Feng; Ying, Guang-Guo; Liu, You-Sheng; Zhang, Qian-Qian; Zhao, Jian-Liang; Liu, Shuang-Shuang; Chen, Jun; Peng, Feng-Jiao; Lai, Hua-Jie; Pan, Chang-Gui

    2014-07-01

    Biocides are widely formulated in household and personal care products. We investigated the distribution and ecological risks of 16 household biocides in aquatic environments of a highly urbanized region in South China, evaluated triclosan as a chemical indicator for this group of household chemicals, and proposed a novel approach to predict the environmental occurrence and fate of these household biocides by using triclosan usage data and a level-III fugacity model. Eleven biocides were quantitatively detected at concentrations up to 264 ± 15.3 ng/L for climbazole in surface water, and up to 5649 ± 748 ng/g for triclocarban in sediment of four rivers in the region. The distribution of biocides in the aquatic environments was significantly correlated with environmental variables such as total nitrogen, total phosphorus and population. Domestic sewage in the region was the dominant pollution source for most biocides such as azole fungicides (fluconazole, climbazole, clotrimazole, ketoconazole, miconazole, and carbendazim) and disinfectants (triclosan and triclocarban). Preliminary risk assessment showed high ecological risks posed by two biocides carbendazim and triclosan in river waters. Mostly important, triclosan was found to be a reliable chemical indicator to surrogate household biocides both in water and sediment based on the correlation analysis. In addition, the fugacity modeling could provide simulated concentrations comparable to the monitoring results. Therefore, with the usage data of the chemical indicator triclosan and correlation formula with other biocides, this model can be applied for predicting the occurrence and fate of various household biocides in a catchment.

  6. Bactericidal paper trays doped with silver nanoparticles for egg storing applications

    Indian Academy of Sciences (India)

    KALIYAPERUMAL VISWANATHAN; M LATHA MALA PRIYADHARSHINI; KARUPPASAMY NIRMALA; MUTHUSAMY RAMAN; GOPAL DHINAKAR RAJ

    2016-06-01

    In this study, a cost-effective way to deposit the silver nanoparticles (AgNPs) on paper egg trays was developed, which proved suitable for prolonged storage of table eggs for house-hold use without deterioration of egg quality. Silver nanoparticles were synthesized based on chemical reduction approach and mixed with gelatin–chitosan mixer used as a colloidal stabilizer as well as fixing agent. AgNPs-doped paper egg trays were characterized by TEM, SEM, FTIR, EDX and XRD. AgNPs containing egg trays were tested for its bactericidal effect against commonly found bacteria on egg shells, E. coli, S. aureus, Streptococcus spp and Salmonella spp. Storing of eggs in the AgNPs-deposited paper egg trays improved the shelf-life of the eggs by more than 14 days compared to controls (eggs stored in conventional trays). In conclusion, the developed paper trays possessed strong antimicrobial activity and it could be an effective storage material for eggs.

  7. Synthesis of nanosilver particles by reverse micelle method and study of their bactericidal properties

    Energy Technology Data Exchange (ETDEWEB)

    Tran Thi Ngoc Dung; Ngo Quoc Buu; Dang Viet Quang; Le Anh Bang; Nguyen Hoai Chau; Nguyen Thi Ly [Institute of Environmental Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay Distr., Hanoi (Viet Nam); Huynh Thi Ha [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay Distr., Hanoi (Viet Nam); Nguyen Vu Trung [National Institute for Infectious and Tropical Diseases, 1 Ton That Tung, Dong Da Distr., Hanoi (Viet Nam)], E-mail: ttndzung@yahoo.com, E-mail: buu_nq@yahoo.com

    2009-09-01

    Nanosilver particles have been synthesized by the reverse micelle method, where AgNO{sub 3} was used as a silver ions source, NaBH{sub 4} and quercetin - as reducing agents, CTAB, SDOSS and AOT- as surfactants, while the stabilizer was Vietnamese chitosan. Studying the factors influencing the process of nanosilver particle formation, it was shown that the particle size of the nanosilver products depends on the concentration of the reaction components and their stoichiometric ratio. It was also shown that the reaction system using AOT surfactant is capable of producing nanosilver particles with smallest nanoparticles ({phi}{sub av} {approx} 5 nm) and good particle-size distribution. The study on bactericidal activity of the nanosilver products indicated that the disinfecting solution with a nanosilver concentration of 3 ppm was able to inhibit all E.coli and Coliforms, TPC and fungi at 15 ppm, while Vibrio cholerae cells were inactivated completely with 0.5 ppm of nanosilver after 30 minutes exposition.

  8. Bactericidal Effect of Pterostilbene Alone and in Combination with Gentamicin against Human Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Wee Xian Lee

    2017-03-01

    Full Text Available The antibacterial activity of pterostilbene in combination with gentamicin against six strains of Gram-positive and Gram-negative bacteria were investigated. The minimum inhibitory concentration and minimum bactericidal concentration of pterostilbene were determined using microdilution technique whereas the synergistic antibacterial activities of pterostilbene in combination with gentamicin were assessed using checkerboard assay and time-kill kinetic study. Results of the present study showed that the combination effects of pterostilbene with gentamicin were synergistic (FIC index < 0.5 against three susceptible bacteria strains: Staphylococcus aureus ATCC 25923, Escherichia coli O157 and Pseudomonas aeruginosa 15442. However, the time-kill study showed that the interaction was indifference which did not significantly differ from the gentamicin treatment. Furthermore, time-kill study showed that the growth of the tested bacteria was completely attenuated with 2 to 8 h treatment with 0.5 × MIC of pterostilbene and gentamicin. The identified combinations could be of effective therapeutic value against bacterial infections. These findings have potential implications in delaying the development of bacterial resistance as the antibacterial effect was achieved with the lower concentrations of antibacterial agents.

  9. Bactericidal Effect of Pterostilbene Alone and in Combination with Gentamicin against Human Pathogenic Bacteria.

    Science.gov (United States)

    Lee, Wee Xian; Basri, Dayang Fredalina; Ghazali, Ahmad Rohi

    2017-03-17

    The antibacterial activity of pterostilbene in combination with gentamicin against six strains of Gram-positive and Gram-negative bacteria were investigated. The minimum inhibitory concentration and minimum bactericidal concentration of pterostilbene were determined using microdilution technique whereas the synergistic antibacterial activities of pterostilbene in combination with gentamicin were assessed using checkerboard assay and time-kill kinetic study. Results of the present study showed that the combination effects of pterostilbene with gentamicin were synergistic (FIC index < 0.5) against three susceptible bacteria strains: Staphylococcus aureus ATCC 25923, Escherichia coli O157 and Pseudomonas aeruginosa 15442. However, the time-kill study showed that the interaction was indifference which did not significantly differ from the gentamicin treatment. Furthermore, time-kill study showed that the growth of the tested bacteria was completely attenuated with 2 to 8 h treatment with 0.5 × MIC of pterostilbene and gentamicin. The identified combinations could be of effective therapeutic value against bacterial infections. These findings have potential implications in delaying the development of bacterial resistance as the antibacterial effect was achieved with the lower concentrations of antibacterial agents.

  10. Avaliação ecotoxicológica do fármaco Triclosan para invertebrados marinhos

    OpenAIRE

    Fernando Sanzi Cortez

    2011-01-01

    Triclosan é um composto orgânico de baixa solubilidade que vem sendo utilizado em formulações de cremes dentais e faciais, xampu, sabonetes, embalagens de gêneros alimentícios e diversos tipos de materiais, tais como, adesivos, brinquedos, sapatos, selantes, tintas, colchão, roupas, pisos, toldos e rejuntes. O amplo uso deste composto deve-se à grande eficácia contra bactérias Gram negativas e Gram positivas. Por seu extenso uso, evidências da presença de Triclosan têm sido frequentemente rel...

  11. Fully automated determination of parabens, triclosan and methyl triclosan in wastewater by microextraction by packed sorbents and gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Marino, Iria, E-mail: iria.gonzalez@usc.es [Department of Analytical Chemistry, Nutrition and Food Sciences, Institute for Food Analysis and Research-IIAA, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Benito Quintana, Jose; Rodriguez, Isaac [Department of Analytical Chemistry, Nutrition and Food Sciences, Institute for Food Analysis and Research-IIAA, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Schrader, Steffi; Moeder, Monika [Department of Analytical Chemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, D-04318 Leipzig (Germany)

    2011-01-17

    A fully automated method for the determination of triclosan (TCS), its derivative methyl triclosan (MeTCS) and six parabens (esters of 4-hydroxybenzoic acid) including branched and linear isomers of propyl (i-PrP and n-PrP) and butyl paraben (i-BuP and n-BuP) in sewage water samples is presented. The procedure includes analytes enrichment by microextraction by packed sorbent (MEPS) coupled at-line to large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS). Under optimised conditions, compounds were extracted from 2 mL samples, adjusted at pH 3, using a C18 MEPS-sorbent. Adsorbed analytes were eluted directly into the Programmable Temperature Vaporizer (PTV) injector of the chromatograph with 2 x 25 {mu}L of ethyl acetate. They were quantified using standard solutions in ultrapure water submitted to the same sample enrichment process as real sewage water samples. After signal normalisation using isotopic labelled species as internal surrogates, no differences were noticed among the extraction efficiency for sewage and ultrapure water; moreover, the proposed method reported lineal calibration curves from 0.1 to 10 ng mL{sup -1}, relative standard deviations (%RSD) between 2 and 7.1% and limits of detection (LODs) varying from 0.001 to 0.015 ng mL{sup -1} in ultrapure water and from 0.02 to 0.59 ng mL{sup -1} in the most complex sample (raw wastewater).

  12. Insights into the photochemical transformation pathways of triclosan and 2′-HO-BDE-28

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ya-nan; Xie, Qing; Chen, Jingwen, E-mail: jwchen@dlut.edu.cn; Li, Yingjie; Fu, Zhiqiang

    2015-12-30

    Highlights: • Direct photolysis of anionic HO-PXDEs occurs through excited singlet states. • Dioxin products are formed from excited singlet states of HO-PXDEs. • Self-sensitized photolysis is involved in the phototransformation of HO-PXDEs. • {sup 1} O{sub 2} and ·OH can be generated in energy or electron transfer reactions between excited HO-PXDEs and dissolved O{sub 2}. - Abstract: Hydroxylated polyhalogenated diphenyl ethers (HO-PXDEs) have been recognized as a group of widely detected emerging contaminants in natural waters. Photolysis was proved to be an important transformation pathway for these compounds and their direct phototransformation results in highly toxic dioxins. However, the roles of excited states and reactive oxygen species in the photochemical transformation of these compounds are still unclear. In this study, 2′-HO-2,4,4′-trichlorodiphenyl ether (triclosan) and 2′-HO-2,4,4′-tribromodiphenyl ether (2′-HO-BDE-28) were selected as model compounds to investigate their phototransformation processes. Results showed that the direct photolysis reactions of both triclosan and 2′-HO-BDE-28 occurred via their respective excited singlet states, leading to the generation of dioxins. In addition, the energy and electron transfer reactions between excited states of model compounds and molecular O{sub 2} can lead to the generation of {sup 1}O{sub 2} and ·OH, which results in self-sensitized photolysis. We also found that both the k, Φ dioxin yield for anionic triclosan were higher than those of anionic 2′-HO-BDE-28. This study revealed the roles of the excited states in direct photolysis and the generation pathway of reactive oxygen species in self-sensitized photolysis of HO-PXDEs, which is important for understanding the phototransformation mechanisms of HO-PXDEs.

  13. Preimplantation Exposure to Bisphenol A and Triclosan May Lead to Implantation Failure in Humans

    Directory of Open Access Journals (Sweden)

    Mu Yuan

    2015-01-01

    Full Text Available Endocrine disrupting chemicals (EDCs are chemicals that have the capacity to interfere with normal endocrine systems. Two EDCs, bisphenol A (BPA and triclosan (TCS, are mass-produced and widespread. They both have estrogenic properties and similar chemical structures and pharmacokinetic features and have been detected in human fluids and tissues. Clinical evidence has suggested a positive association between BPA exposure and implantation failure in IVF patients. Studies in mouse models have suggested that preimplantation exposure to BPA and TCS can lead to implantation failure. This paper reviews the relationship between preimplantation exposure to BPA and TCS and implantation failure and discusses the remaining problems and possible solutions.

  14. Preparation of AgBr@SiO{sub 2} core@shell hybrid nanoparticles and their bactericidal activity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yuanyuan [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Yang, Lisu [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Henna Sports School, Zhengzhou 450045 (China); Zhao, Yanbao, E-mail: yanbaozhao@126.com [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Li, Binjie; Sun, Lei; Luo, Huajuan [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China)

    2013-04-01

    AgBr@SiO{sub 2} core@shell hybrid nanoparticles (NPs) were successfully prepared by sol-gel method. Their morphology and structure were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The hybrid NPs are predominantly spherical in shape, with an average diameter of 180–200 nm, and each NP contains one inorganic core. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the hybrid NPs were examined against Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli), respectively. Results indicated that the AgBr@SiO{sub 2} NPs had excellent antibacterial activity. - Highlights: ► Presents a novel antibacterial agent “AgBr@ SiO{sub 2} NPs”. ► AgBr@SiO{sub 2} hybrid NPs could provide long-term antimicrobial effect. ► AgBr@SiO{sub 2} hybrid NPs have excellent antibacterial activity.

  15. Antimicrobial Activity of Peptides Derived from Olive Flounder Lipopolysaccharide Binding Protein/Bactericidal Permeability-Increasing Protein (LBP/BPI

    Directory of Open Access Journals (Sweden)

    Bo-Hye Nam

    2014-10-01

    Full Text Available We describe the antimicrobial function of peptides derived from the C-terminus of the olive flounder LBP BPI precursor protein. The investigated peptides, namely, ofLBP1N, ofLBP2A, ofLBP4N, ofLBP5A, and ofLBP6A, formed α-helical structures, showing significant antimicrobial activity against several Gram-negative bacteria, Gram-positive bacteria, and the yeast Candida albicans, but very limited hemolytic activities. The biological activities of these five analogs were evaluated against biomembranes or artificial membranes for the development of candidate therapeutic agents. Gel retardation studies revealed that peptides bound to DNA and inhibited migration on an agarose gel. In addition, we demonstrated that ofLBP6A inhibited polymerase chain reaction. These results suggested that the ofLBP-derived peptide bactericidal mechanism may be related to the interaction with intracellular components such as DNA or polymerase.

  16. Correlation between bactericidal activity of fosfomycin trometamol in an in vitro model of the urinary bladder and susceptibility testing.

    Science.gov (United States)

    Pinasi, C; Albini, E; Marca, G

    1987-01-01

    The present study was undertaken to define an interpretative guideline for disk diffusion susceptibility testing with fosfomycin trometamol, a new antimicrobial agent which has been developed for the treatment of urinary tract infections. Two potencies of fosfomycin disk were used: 50 and 200 micrograms, prepared in the presence and absence of glucose-6-phosphate. To verify the reliability of the results obtained in susceptibility testing, we have also evaluated the bactericidal activity of fosfomycin trometamol versus sensitive and resistant strains in an 'in vitro' model simulating the hydrokinetic aspects involved in the treatment of bacterial cystitis. The data obtained evidenced the role of glucose-6-phosphate in antimicrobial susceptibility tests as well as the importance of the urinary antibiotic concentrations to define sensitive and resistant bacteria. On the basis of our results, we recommend that a 200-microgram disk of fosfomycin containing 50 micrograms of glucose-6-phosphate should be used in antimicrobial susceptibility testing with fosfomycin trometamol.

  17. Antimicrobial activity of peptides derived from olive flounder lipopolysaccharide binding protein/bactericidal permeability-increasing protein (LBP/BPI).

    Science.gov (United States)

    Nam, Bo-Hye; Moon, Ji-Young; Park, Eun-Hee; Kim, Young-Ok; Kim, Dong-Gyun; Kong, Hee Jeong; Kim, Woo-Jin; Jee, Young Ju; An, Cheul Min; Park, Nam Gyu; Seo, Jung-Kil

    2014-10-17

    We describe the antimicrobial function of peptides derived from the C-terminus of the olive flounder LBP BPI precursor protein. The investigated peptides, namely, ofLBP1N, ofLBP2A, ofLBP4N, ofLBP5A, and ofLBP6A, formed α-helical structures, showing significant antimicrobial activity against several Gram-negative bacteria, Gram-positive bacteria, and the yeast Candida albicans, but very limited hemolytic activities. The biological activities of these five analogs were evaluated against biomembranes or artificial membranes for the development of candidate therapeutic agents. Gel retardation studies revealed that peptides bound to DNA and inhibited migration on an agarose gel. In addition, we demonstrated that ofLBP6A inhibited polymerase chain reaction. These results suggested that the ofLBP-derived peptide bactericidal mechanism may be related to the interaction with intracellular components such as DNA or polymerase.

  18. Two approaches to form antibacterial surface: Doping with bactericidal element and drug loading

    Energy Technology Data Exchange (ETDEWEB)

    Sukhorukova, I.V.; Sheveyko, A.N.; Kiryukhantsev-Korneev, Ph.V. [National University of Science and Technology “MISIS”, Leninsky pr. 4, Moscow 119049 (Russian Federation); Anisimova, N.Y.; Gloushankova, N.A.; Zhitnyak, I.Y. [N.N Blokhin Russian Cancer Research Center of RAMS, Kashirskoe shosse 24, Moscow 115478 (Russian Federation); Benesova, J. [Institute of Experimental Medicine of the ASCR, Vídenska 1083, Prague 14220 (Czech Republic); Institute of Biophysics, 2nd Faculty of Medicine, Charles University in Prague, V Uvalu 84, Prague 15006 (Czech Republic); Amler, E. [Institute of Experimental Medicine of the ASCR, Vídenska 1083, Prague 14220 (Czech Republic); Faculty of Biomedical Engineering, Czech Technical University in Prague (Czech Republic); Shtansky, D.V., E-mail: shtansky@shs.misis.ru [National University of Science and Technology “MISIS”, Leninsky pr. 4, Moscow 119049 (Russian Federation)

    2015-03-01

    Graphical abstract: - Highlights: • Bioactive materials with rate-controlled release of antibacterial agent. • Ag{sup +} ion release from TiCaPCON-Ag films depended on Ag content. • TiCaPCON-coated Ti network structure with blind pores loaded with co-amoxiclav. • Strong bactericidal effect of drug-loaded samples. • Antibacterial yet biocompatible and bioactive surfaces. - Abstract: Two approaches (surface doping with bactericidal element and loading of antibiotic into specially formed surface microcontainers) to the fabrication of antibacterial yet biocompatible and bioactive surfaces are described. A network structure with square-shaped blind pores of 2.6 ± 0.6 × 10{sup −3} mm{sup 3} for drug loading was obtained by selective laser sintering (SLS). The SLS-fabricated samples were loaded with 0.03, 0.3, 2.4, and 4 mg/cm{sup 2} of co-amoxiclav (amoxicillin and clavulanic acid). Ag-doped TiCaPCON films with 0.4, 1.2, and 4.0 at.% of Ag were obtained by co-sputtering of composite TiC{sub 0.5}-Ca{sub 3}(PO{sub 4}){sub 2} and metallic Ag targets. The surface structure of SLS-prepared samples and cross-sectional morphology of TiCaPCON-Ag films were studied by scanning electron microscopy. The through-thickness of Ag distribution in the TiCaPCON-Ag films was obtained by glow discharge optical emission spectroscopy. The kinetics of Ag ion release in normal saline solution was studied using inductively coupled plasma mass spectrometry. Bacterial activity of the samples was evaluated against S. epidermidis, S. aureus, and K. pneum. ozaenae using the agar diffusion test and photometric method by controlling the variation of optical density of the bacterial suspension over time. Cytocompatibility of the Ag-doped TiCaPCON films was observed in vitro using chondrocytic and MC3T3-E1 osteoblastic cells. The viability and proliferation of chondrocytic cells were determined using the MTS assay and PicoGreen assay tests, respectively. The alkaline phosphatase (ALP

  19. Effect of habituation to tea tree (Melaleuca alternifolia) oil on the subsequent susceptibility of Staphylococcus spp. to antimicrobials, triclosan, tea tree oil, terpinen-4-ol and carvacrol.

    Science.gov (United States)

    Thomsen, Natalie A; Hammer, Katherine A; Riley, Thomas V; Van Belkum, Alex; Carson, Christine F

    2013-04-01

    The aim of this study was to seek additional data on the antimicrobial susceptibility of Staphylococcus spp. after habituation to low levels of the topical antimicrobial agent tea tree (Melaleuca alternifolia) oil. Meticillin-susceptible Staphylococcus aureus (MSSA), meticillin-resistant S. aureus (MRSA) and coagulase-negative staphylococci (CoNS) were habituated to 0.075% tea tree oil for 3 days. Subsequently, the susceptibility of five isolates each of MSSA, MRSA and CoNS to fusidic acid, mupirocin, chloramphenicol, linezolid and vancomycin was determined by Etest, and susceptibility to tea tree oil, terpinen-4-ol, carvacrol and triclosan was determined by agar dilution. Following habituation to 0.075% tea tree oil, antimicrobial MICs differed between control and habituated isolates on 33 occasions (out of a possible 150), with MICs being higher in habituated isolates on 22 occasions. Using clinical breakpoint criteria, one MSSA isolate changed susceptibility category from vancomycin-susceptible (MIC=2 μg/mL) to intermediate susceptibility (MIC=3 μg/mL) after habituation in one of two replicates. For the non-antibiotic antimicrobial agents, MICs of habituated and control isolates differed on 12 occasions (out of a possible 120); 10 occasions in MRSA and 2 occasions in MSSA. MICs were higher for habituated isolates on five occasions. However, all the differences were one serial dilution only and were not regarded as significant. Habituation to sublethal concentrations of tea tree oil led to minor changes in MICs of antimicrobial agents, only one of which may have been clinically relevant. There is no evidence to suggest that tea tree oil induces resistance to antimicrobial agents.

  20. Chemical Conversion Pathways and Kinetic Modeling for the OH-Initiated Reaction of Triclosan in Gas-Phase

    Directory of Open Access Journals (Sweden)

    Xue Zhang

    2015-04-01

    Full Text Available As a widely used antimicrobial additive in daily consumption, attention has been paid to the degradation and conversion of triclosan for a long time. The quantum chemistry calculation and the canonical variational transition state theory are employed to investigate the mechanism and kinetic property. Besides addition and abstraction, oxidation pathways and further conversion pathways are also considered. The OH radicals could degrade triclosan to phenols, aldehydes, and other easily degradable substances. The conversion mechanisms of triclosan to the polychlorinated dibenzopdioxin and furan (PCDD/Fs and polychlorinated biphenyls (PCBs are clearly illustrated and the toxicity would be strengthened in such pathways. Single radical and diradical pathways are compared to study the conversion mechanism of dichlorodibenzo dioxin (DCDD. Furthermore, thermochemistry is discussed in detail. Kinetic property is calculated and the consequent ratio of kadd/ktotal and kabs/ktotal at 298.15 K are 0.955 and 0.045, respectively. Thus, the OH radical addition reactions are predominant, the substitute position of OH radical on triclosan is very important to generate PCDD and furan, and biradical is also a vital intermediate to produce dioxin.

  1. Effects of triclosan, diclofenac, and nonylphenol on mesophilic and thermophilic methanogenic activity and on the methanogenic communities

    DEFF Research Database (Denmark)

    Symsaris, Evangelos C.; Fotidis, Ioannis; Stasinakis, Athanasios S.

    2015-01-01

    In this study, a toxicity assay using a mesophilic wastewater treatment plant sludge-based (SI) and a thermophilic manure-based inoculum (MI), under different biomass concentrations was performed to define the effects of diclofenac (DCF), triclosan (TCS), and nonylphenol (NP) on anaerobic digestion...

  2. Effects of triclosan on aquatic invertebrates in tropics and the influence of pH on its toxicity on microalgae

    NARCIS (Netherlands)

    Khatikarn, Jidapa; Satapornvanit, Kriengkrai; Price, Oliver R.; Den Brink, van Paul J.

    2016-01-01

    The antimicrobial triclosan (TCS) has been detected in household wastewaters (untreated and treated) and receiving environments across the globe. The toxic effects of TCS on temperate standard aquatic test organisms have been widely reported with microalgae being the most sensitive. However,

  3. Using equilibrium passive dosing to maintain stable exposure concentrations of triclosan in a 6-week toxicity test

    DEFF Research Database (Denmark)

    Sobek, A.; Ribbenstedt, A.; Mustajärvi, L.

    2015-01-01

    stable exposure concentrations of triclosan (log Kow 4.8) in a 6-week multigeneration test with the benthic copepod Nitocra spinipes. The tests were performed in 10 mL vials casted with 1000 mg of silicone (DC 1-2577). Based on a previous pilot study, three triclosan concentrations were selected...... and tested (15 μg L-1; 30 μg L-1; 60 μg L-1) as well as a control (no triclosan). At test beginning, each vial contained 12 individuals consisting of 3 individuals from four different life stages. The test includes feeding with phytoplankton three times a week, which can lead to declining freely dissolved...... triclosan concentrations. In the present study this was buffered by passive dosing. Water was exchanged every 7th day by transferring the animals from the spend solution into a pre-equilibrated passive dosing glass. During the first two weeks, the copepods grow exponentially and can reach numbers of several...

  4. Spatial Distribution of the Emerging Contaminant Triclosan in the Sediments of an Urbanized Estuary: Greenwich Bay, Rhode Island, USA

    Science.gov (United States)

    Increase in the use of personal care products (PCPs) has resulted in the release and accumulation of a diverse assemblage of emerging chemicals in the environment. One such chemical, triclosan (TCS), an antimicrobial compound, has been incorporated into many PCPs for approximate...

  5. Effects of triclosan on aquatic invertebrates in tropics and the influence of pH on its toxicity on microalgae

    NARCIS (Netherlands)

    Khatikarn, Jidapa; Satapornvanit, Kriengkrai; Price, Oliver R.; Den Brink, van Paul J.

    2016-01-01

    The antimicrobial triclosan (TCS) has been detected in household wastewaters (untreated and treated) and receiving environments across the globe. The toxic effects of TCS on temperate standard aquatic test organisms have been widely reported with microalgae being the most sensitive. However, envi

  6. Using a Novel Sediment Exposure to Determine the Effects of Triclosan on Marine Benthic Communities (SETAC Europe)

    Science.gov (United States)

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol), is an emerging contaminant commonly used as an antimicrobial compound in many personal care products such as softsoap, detergent, toothpaste, mouthwash, and is infused in many consumer products, such as kitchen utensils, toys, b...

  7. Spatial Variability of Factors Influencing the Distribution of Triclosan in Sediments and Water of an Urbanized Estuarine Embayment

    Science.gov (United States)

    Triclosan (TCS) is a broad spectrum anti-microbial compound added to many consumer and personal care products. TCS enters water bodies primarily through wastewater treatment plant (WWTP) effluent and may be introduced by combined sewer overflows or surface water runoff. In estu...

  8. Spatial Distribution of the Emerging Contaminant Triclosan in Sediments and Water of an Urbanized Estuary: Greenwich Bay, Rhode Island, USA

    Science.gov (United States)

    The use of personal care products (PCPs) has resulted in the release and accumulation of a diverse assemblage of emerging chemicals in the environment. Many PCPs incorporate triclosan (TCS), an antimicrobial compound, within their formulations and as a result, TCS is frequently ...

  9. Effect of biosolids-derived triclosan and triclocarban on the colonization of plant roots by arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Prosser, R S; Lissemore, L; Shahmohamadloo, R S; Sibley, P K

    2015-03-01

    Arbuscular mycorrhizal fungi (AMF) form a symbiotic relationship with the majority of crop plants. AMF provide plants with nutrients (e.g., P), modulate the effect of metal and pathogen exposure, and increase tolerance to moisture stress. The benefits of AMF to plant growth make them important to the development of sustainable agriculture. The land application of biosolids is becoming an increasingly common practice in sustainable agriculture, as a source of nutrients. However, biosolids have been found to contain numerous pharmaceutical and personal care products including antimicrobial chemicals such as triclosan and triclocarban. The potential risks that these two compounds may pose to plant-AMF interactions are poorly understood. The current study investigated whether biosolids-derived triclosan and triclocarban affect the colonization of the roots of lettuce and corn plants by AMF. Plants were grown in soil amended with biosolids that contained increasing concentrations of triclosan (0 to 307 μg/g dw) or triclocarban (0 to 304 μg/g dw). A relationship between the concentration of triclosan or triclocarban and colonization of plants roots by AMF was not observed. The presence of biosolids did not have a significant (p>0.05) effect on percent colonization of corn roots but had a significant, positive effect (ptriclosan and triclocarban did not inhibit the colonization of crop plant roots by AMF.

  10. Complete Genome Sequence of the Triclosan- and Multidrug-Resistant Pseudomonas aeruginosa Strain B10W Isolated from Municipal Wastewater

    Science.gov (United States)

    Zhong, Chuanqing; Nelson, Matthew; Cao, Guangxiang

    2017-01-01

    ABSTRACT Here, we report the complete genome sequence of the triclosan- and multidrug-resistant Pseudomonas aeruginosa strain B10W, obtained from municipal wastewater in Hawaii. The bacterium has a 6.7-Mb genome, contains 6,391 coding sequences and 78 RNAs, with an average G+C content of 66.2 mol%. PMID:28104659

  11. Plaque control evaluation of a stabilized stannous fluoride dentifrice compared to a triclosan dentifrice in a six-week trial.

    Science.gov (United States)

    Sharma, N; He, T; Barker, M L; Biesbrock, A R

    2013-01-01

    To compare the anti-plaque efficacy of a stabilized 0.454% stannous fluoride (referred to as SnF2) dentifrice versus a 0.3% triclosan dentifrice formulated with a copolymer and sodium fluoride (referred to as triclosan). The study had a randomized, double-blind, two-treatment, parallel-group design, and compared plaque reduction from baseline after both three and six weeks of treatment with either the SnF2 or triclosan dentifrices using a manual toothbrush. Subjects brushed their teeth using their assigned treatment dentifrices according to the manufacturer's instructions. Following overnight plaque accumulation, levels of plaque were assessed by an experienced examiner using the Rustogi, et al. Modified Navy Plaque Index at the start of the study (baseline), and after three and six weeks of regular brushing. Groups were compared using analysis of covariance separately for Weeks 3 and 6, and by repeated measures for Weeks 3 and 6 combined. One-hundred and twenty subjects were randomized to treatment and 114 subjects completed the study. Both treatment groups showed a statistically significant reduction from baseline in mean plaque values for all three tooth areas (whole mouth, gingival margin, interproximal) at both Weeks 3 and 6 (p dentifrices showed statistically significant reductions from baseline in whole mouth, gumline, and interproximal accumulated overnight plaque after three and six weeks of brushing, but the SnF2 dentifrice showed statistically significantly greater plaque reductions versus the triclosan dentifrice.

  12. Efficacy of a silicone urinary catheter impregnated with chlorhexidine and triclosan against colonization with Proteus mirabilis and other uropathogens.

    Science.gov (United States)

    Gaonkar, Trupti A; Caraos, Lauserpina; Modak, Shanta

    2007-05-01

    We sought to develop an infection-resistant urinary catheter. We evaluated 3 types of catheters for their efficacy against uropathogens in an in vitro model of the urinary tract. The catheter impregnated with chlorhexidine and triclosan suppressed the growth of uropathogens, including Proteus mirabilis, for 20-30 days or longer.

  13. Studies of Toxoplasma gondii and Plasmodium falciparum enoyl acyl carrier protein reductase and implications for the development of antiparasitic agents

    Energy Technology Data Exchange (ETDEWEB)

    Muench, Stephen P. [The Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN (United Kingdom); Prigge, Sean T. [Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); McLeod, Rima [Department of Ophthalmology and Visual Sciences, Paediatrics (Infectious Diseases) and Pathology and the Committees on Molecular Medicine, Genetics, Immunology and The College, The University of Chicago, Chicago, IL 60637 (United States); Rafferty, John B. [The Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN (United Kingdom); Kirisits, Michael J. [Department of Ophthalmology and Visual Sciences, Paediatrics (Infectious Diseases) and Pathology and the Committees on Molecular Medicine, Genetics, Immunology and The College, The University of Chicago, Chicago, IL 60637 (United States); Roberts, Craig W. [Department of Immunology, University of Strathclyde, Glasgow G4 0NR, Scotland (United Kingdom); Mui, Ernest J. [Department of Ophthalmology and Visual Sciences, Paediatrics (Infectious Diseases) and Pathology and the Committees on Molecular Medicine, Genetics, Immunology and The College, The University of Chicago, Chicago, IL 60637 (United States); Rice, David W., E-mail: d.rice@sheffield.ac.uk [The Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN (United Kingdom)

    2007-03-01

    The crystal structures of T. gondii and P. falciparum ENR in complex with NAD{sup +} and triclosan and of T. gondii ENR in an apo form have been solved to 2.6, 2.2 and 2.8 Å, respectively. Recent studies have demonstrated that submicromolar concentrations of the biocide triclosan arrest the growth of the apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii and inhibit the activity of the apicomplexan enoyl acyl carrier protein reductase (ENR). The crystal structures of T. gondii and P. falciparum ENR in complex with NAD{sup +} and triclosan and of T. gondii ENR in an apo form have been solved to 2.6, 2.2 and 2.8 Å, respectively. The structures of T. gondii ENR have revealed that, as in its bacterial and plant homologues, a loop region which flanks the active site becomes ordered upon inhibitor binding, resulting in the slow tight binding of triclosan. In addition, the T. gondii ENR–triclosan complex reveals the folding of a hydrophilic insert common to the apicomplexan family that flanks the substrate-binding domain and is disordered in all other reported apicomplexan ENR structures. Structural comparison of the apicomplexan ENR structures with their bacterial and plant counterparts has revealed that although the active sites of the parasite enzymes are broadly similar to those of their bacterial counterparts, there are a number of important differences within the drug-binding pocket that reduce the packing interactions formed with several inhibitors in the apicomplexan ENR enzymes. Together with other significant structural differences, this provides a possible explanation of the lower affinity of the parasite ENR enzyme family for aminopyridine-based inhibitors, suggesting that an effective antiparasitic agent may well be distinct from equivalent antimicrobials.

  14. Treatment and prevention of Staphylococcus epidermidis experimental biomaterial-associated infection by bactericidal peptide 2

    NARCIS (Netherlands)

    P.H.S. Kwakman; A.A.T. Velde; C.M.J.E. Vandenbroucke-Grauls; S.J.H. van Deventer; S.A.J. Zaat

    2006-01-01

    Biomaterial-associated infections (BAI) are the major cause of failure of indwelling medical devices and are predominantly caused by staphylococci, especially Staphylococcus epidermidis. We investigated the in vitro microbicidal activity of the synthetic antimicrobial peptide bactericidal peptide 2

  15. Serum bactericidal activity as indicator of innate immunity in pacu Piaractus mesopotamicus (Holmberg, 1887

    Directory of Open Access Journals (Sweden)

    J.D. Biller-Takahashi

    2013-12-01

    Full Text Available The immune system of teleost fish has mechanisms responsible for the defense against bacteria through protective proteins in several tissues. The protein action can be evaluated by serum bactericidal activity and this is an important tool to analyze the immune system. Pacu, Piaractus mesopotamicus, is one of the most important fish in national aquaculture. However there is a lack of studies on its immune responses. In order to standardize and assess the accuracy of the serum bactericidal activity assay, fish were briefly challenged with Aeromonas hydrophila and sampled one week after the challenge. The bacterial infection increased the concentration of protective proteins, resulting in a decrease of colony-forming unit values expressed as well as an enhanced serum bactericidal activity. The protocol showed a reliable assay, appropriate to determine the serum bactericidal activity of pacu in the present experimental conditions.

  16. Efficacy of a triclosan formula in controlling early subgingival biofilm formation: a randomized trial.

    Science.gov (United States)

    Andrade, Ernesto; Weidlich, Patricia; Angst, Patrícia Daniela Melchiors; Gomes, Sabrina Carvalho; Oppermann, Rui Vicente

    2015-01-01

    The aim of this study was to determine the efficacy of rinses with slurries of a dentifrice containing triclosan (TCS), as compared with rinses with slurries from a control dentifrice, in controlling early subgingival biofilm formation. A double-blind, randomized and cross-over clinical trial was designed, and 26 dental students were included. In the first period, participants were randomized to rinse with a TCS slurry or a control slurry, in a 12 h interval, and to refrain from mechanical cleaning. A Plaque Free Zone Index was assessed at 24 h, 48 h, 72 h and 96 h. After a washout period of 10 days, the second experimental period was conducted, following the same protocol as the first period, except that the slurry groups were switched. Use of the TCS slurry resulted in a significantly higher percentage of plaque-free surfaces, both at 24 h and at 72 h (p < 0.01). In the of 48-72 h interval, the triclosan slurry showed a lower percentage of sites converted to a score of 2 (38.1% for the test versus 40% for the control product, p = 0.015). In conclusion, rinsing with slurries of dentifrice containing TCS retards the down growth of bacterial biofilms from the supra- to the subgingival environment.

  17. Efficacy of a triclosan formula in controlling early subgingival biofilm formation: a randomized trial

    Directory of Open Access Journals (Sweden)

    Ernesto ANDRADE

    2015-01-01

    Full Text Available The aim of this study was to determine the efficacy of rinses with slurries of a dentifrice containing triclosan (TCS, as compared with rinses with slurries from a control dentifrice, in controlling early subgingival biofilm formation. A double-blind, randomized and cross-over clinical trial was designed, and 26 dental students were included. In the first period, participants were randomized to rinse with a TCS slurry or a control slurry, in a 12 h interval, and to refrain from mechanical cleaning. A Plaque Free Zone Index was assessed at 24 h, 48 h, 72 h and 96 h. After a washout period of 10 days, the second experimental period was conducted, following the same protocol as the first period, except that the slurry groups were switched. Use of the TCS slurry resulted in a significantly higher percentage of plaque-free surfaces, both at 24 h and at 72 h (p < 0.01. In the of 48-72 h interval, the triclosan slurry showed a lower percentage of sites converted to a score of 2 (38.1% for the testversus 40% for the control product, p = 0.015. In conclusion, rinsing with slurries of dentifrice containing TCS retards the down growth of bacterial biofilms from the supra- to the subgingival environment.

  18. Comparison of hand hygiene antimicrobial efficacy: Melaleuca alternifolia essential oil versus triclosan

    Directory of Open Access Journals (Sweden)

    Juliana Rizzo Gnatta

    2013-12-01

    Full Text Available OBJECTIVE: this study aimed to evaluate the efficacy of hand hygiene performed with two different soap formulations: 0.3% Melaleuca alternifolia essential oil versus 0.5% triclosan, and to compare them with two reference hygiene procedures: the official methodology procedure (soft soap versus the draft version of the procedure (soft soap + propan-2-ol. METHOD: using the European EN 1499 method, logarithmic reduction factors were determined for the number of colony forming units of Escherichia coli K12 before and after hand hygiene of 15 volunteer subjects, and compared using the one-tailed Wilcoxon test. RESULTS: referring to the soft soap, there was no difference between the performance of soap with 0.3% M. alternifolia and soap containing 0.5% triclosan. The soft soap + propan-2-ol proved to be more effective than the other hand hygiene procedures. CONCLUSION: studies to verify the therapeutic efficacy of essential oil in hand hygiene can improve adherence to this practice.

  19. Triclosan/triclocarban levels in maternal and umbilical blood samples and their association with fetal malformation.

    Science.gov (United States)

    Wei, Ling; Qiao, Pengyun; Shi, Ying; Ruan, Yan; Yin, Jie; Wu, Qingqing; Shao, Bing

    2017-03-01

    Triclosan (TCS) and triclocarban (TCC) are widely used as antimicrobial compounds in consumer products. TCS and TCC are frequently found in waste water and sewage. In this study, we investigate the potential impact of exposure to triclosan (TCS) and triclocarban (TCC) on fetal abnormalities. We measured TCS and TCC levels in maternal and umbilical cord blood samples from 39 pregnant women diagnosed with fetal or post-birth abnormalities at Beijing Obstetrics and Gynecology Hospital. 52 pregnant women who gave birth to healthy neonates during the same period of time were included as controls. Applying ultra-performance liquid chromatography-tandem mass spectrometry, TCS and TCC concentrations were measured in maternal and fetal sera. Significantly increased levels of TCS were detected in maternal sera from mothers with abnormal births. Similar levels of TCS or TCC were found in maternal and cord sera in control group. The concentrations of TCS or TCC in maternal sera correlated with those in umbilical cord sera (r=0.649, P<0.01). These observations suggest that maternal blood test could be a useful assay for detecting fetal exposure to TCS and TCC, and high exposure to TCS may be potentially associated with increased risk for fetal malformations.

  20. Effect of xylitol, sodium fluoride and triclosan containing mouth rinse on Streptococcus mutans

    Directory of Open Access Journals (Sweden)

    Priya Subramaniam

    2011-01-01

    Full Text Available Introduction : Prevention of dental caries is one of the main strategies in contemporary pediatric dental practice. Mouth rinses are widely used as an adjunct to maintain oral hygiene. It is important for these products to be effective and safe for regular use in children. Objective : The aim of the study was to investigate the efficacy of a newly introduced xylitol, sodium fluoride and triclosan containing mouth rinse in reducing levels of plaque Streptococcus mutans and to compare it with that of a 0.12% chlorhexidine mouth rinse. Materials and Methods : Thirty children were randomly divided into two groups of 15 children each. Group I (study group was given a mouth rinse containing xylitol (5%, sodium fluoride (0.05% and triclosan (0.03% and Group II (control group was given a chlorhexidine (0.12% mouth rinse. Both mouth rinses were alcohol free. Mouth rinsing was carried out twice daily, half an hour after breakfast and half an hour following dinner, for a period of 21 days under the supervision of the investigator. Results: In both groups, there was a significant reduction in the mean S. mutans count at the end of 21 days (P < 0.001. No significant difference was observed between the two mouth rinses. Conclusion: The use of a low fluoride-xylitol based mouth rinse appears to be a suitable choice for regular use in children.

  1. Null bactericidal effect of ultraviolet radiation emitted by LEDs.

    Directory of Open Access Journals (Sweden)

    Francisco Alcántara Muñoz

    2016-11-01

    Full Text Available This research has aimed to assess the bactericidal effect of ultraviolet light emitted by LEDS on the growth on Petri dishes of microorganisms whose legal limits in foods have been established. An electrically fed apparatus has been designed with precise timing and a camera to prevent light spillage, in which two ultraviolet radiation emission devices were connected by LED technology at different wavelengths: through an array of LEDS emitting at around 350nm, and a single specific emission LED at 280nm. 1000 cfu of E. Coli and S. aureus sown on PCA were used as prototypes of gram negative and positive bacteria, respectively, onto which ultraviolet light was radiated at different time intervals, by means of both devices, with the whole experiment being carried out in triplicate . In none of the three series of treatments at the two wavelengths were reductions in microbial growth observed. The series of sowings on PCA were done on unseeded plates in order to be able to discard the likelihood of subsequent recontamination.

  2. The Application of Bactericidal Silver Nanoparticles in Wound Treatment

    Directory of Open Access Journals (Sweden)

    Geewoo Nam

    2015-07-01

    Full Text Available Even with the prevalence of wounds, the medical technol‐ ogy for efficiently managing skin damage is still primitive. The disruption of any of the numerous healing processes can lead to problems in the time-sensitive healing actions of the dermal and epidermal layers. Bacterial infection is one of the major obstacles to proper wound healing as it poses a danger of causing long-term negative effects. Keeping the wound free of bacteria is imperative to the proper and hasty repair of dermal wounds. Silver has been widely used to treat wounds for its bactericidal properties. Although the mechanism of silver’s antibacterial action is not fully understood, it exhibits a significant antimicrobial efficacy against a wide spectrum of bacterial species. A number of different approaches to the mechanism are reported and presented in this review. Silver nanoparticles (AgNPs have been reported to exhibit enhanced antibac‐ terial activity due to their increased surface-area-to-volume ratio. AgNPs are capable of various modifications, signifi‐ cantly broadening the therapeutic properties of the mate‐ rial as a result. This review explores the different aspects of silver and silver nanoparticles, and their antibacterial properties, which can be applied in the field of wound treatments.

  3. Bactericidal effect of Nd:YAG laser irradiation in endodontics

    Science.gov (United States)

    Aun, Carlos E.; Barberini, Alexandre F.; Camargo, Selma C. C.; Silva Kfouri, Luciana; Lorenzetti Simionato, Maria R.

    1999-05-01

    The success of endodontic therapy is based on the elimination of bacterial colonization from the endodontic system and periapical tissues. Recent studies have been showing the bactericidal effect of laser in root canal treatment. The propose of the study is to evaluate the effect of Nd:YAG laser irradiation in contaminated root canal treatment. The propose of the study is to evaluate the effect of Nd:YAG laser irradiation in contaminated root canals from upper central incisor. For the experiment 12 teeth were selected, respect at the apical third, sterilized, and 10 μm Streptococcus sanguis liquid culture were inoculated in the root canals. The laser test groups were irradiated with Nd:YAG laser at standard setting of 15Hz, 100mj and 1,5 W for 10, 20 and 30 seconds each in slow helicoidal movements from the apex to the top using a 300 micrometers fiber. After the procedure the specimens were placed in Tryptic Soy Agar, the number of colony forming units was evaluated. The experiment showed a significant reduction on viability of Streptococcus sanguis at the respective time of 20 and 30 seconds.

  4. The influence of a triclosan toothpaste on adverse events in patients with cardiovascular disease over 5-years.

    Science.gov (United States)

    Cullinan, Mary P; Palmer, Janet E; Carle, Anne D; West, Malcolm J; Westerman, Bill; Seymour, Gregory J

    2015-03-01

    Adverse effects of long-term usage of triclosan-containing toothpaste in humans are currently unknown. We assessed the effect of long-term use of 0.3% triclosan-toothpaste on serious adverse events (SAEs) in patients with cardiovascular disease (CVD). 438 patients with a history of stable CVD were entered into the 5-year longitudinal Cardiovascular and Periodontal Study at Prince Charles Hospital, Brisbane, Australia and randomised into test (triclosan) or placebo groups. There were no significant differences in demographics or clinical features between the groups. Patients were examined at baseline, and annually for 5-years. SAEs were classified according to the System Organ Classes defined by MedDRA (Medical Dictionary for Regulatory Activities). Results were analysed using chi square and Kaplan Meier analysis. Overall, 232 patients (123 in the triclosan group; 109 in the placebo group) experienced 569 SAEs (288 in the triclosan group and 281 in the placebo group). There was no significant difference between the groups in numbers of patients experiencing SAEs (p=0.35) or specific cardiovascular SAEs (p=0.82), nor in time to the first SAE or first cardiovascular SAE, irrespective of gender, age or BMI after adjusting for multiple comparisons (p>0.05). The adjusted odds of experiencing an SAE were estimated to increase by 2.7% for each year of age (p=0.02) and the adjusted odds of experiencing a cardiovascular SAE were estimated to increase by 5.1% for each unit increase in BMI (p=0.02). Most cardiovascular events were related to unstable angina or myocardial infarcts, 21 were associated with arrhythmia and 41 were vascular events such as aortic aneurysm and cerebrovascular accident. Within the limitations of the present study the data suggest that the use of triclosan-toothpaste may not be associated with any increase in SAEs in this CVD population. The long-term impact of triclosan on hormone-related disease, such as cancer, in humans remains to be determined.

  5. Fungi and bacteria. [fungicide and bactericide measures for spacecraft in tropical regions

    Science.gov (United States)

    Daniels, G. E.

    1973-01-01

    Spacecraft equipment is usually protected from fungi and bacteria by incorporating a fungicide-bactericide in the material, by a fungicide-bactericide spray, or by reducing the relative humidity to a degree where growth will not take place. A unique method to protect delicate, expensive bearings in equipment was to maintain a pressure (with dry air or nitrogen) slightly above the outside atmosphere (few millibars) within the working parts of the equipment, thus preventing fungi from entering equipment.

  6. [Bactericidal activity of sitafloxacin and other new quinolones against antimicrobial resistant Streptococcus pneumoniae].

    Science.gov (United States)

    Kobayashi, Intetsu; Kanayama, Akiko; Hasegawa, Miyuki; Kaneko, Akihiro

    2013-02-01

    We conducted a study assess the bactericidal activity of sitafloxacin (STFX) against Streptococcus pneumoniae isolates recovered from respiratory infections including penicillin-resistant (PRSP) isolates, macrolide resistant isolates possessing mefA and ermB resistance genes and quinolone resistance isolates with mutations in gyrA or gyrA and parC. Each isolate tested was grown in hemosupplemented Mueller-Hinton broth and adjusted to approximately 10(5) CFU/ mL. Isolates were than exposed to a Cmax antimicrobial blood level that would be attained with routine antimicrobial administration and an antimicrobial level that would be expected 4 hours post-Cmax (Cmax 4hr). Bactericidal activity was measured for up to 8 hours. Excluding a subset of S. pneumoniae isolates with mutations in the quinolone resistance determining region (QRDR), all quinolones showed bactericidal activity at Cmax and Cmax 4 hr antimicrobial concentrations for up to 8 hours. Against S. pneumoniae isolates with either gyrA or gyrA and parC mutations, bactericidal activity of STFX was shown for up to 4 to 8 hours following Cmax based on a limit of detection of quinolones tested where adjusted to concentrations corresponding to their MICs, STFX showed the most rapid bactericidal activity against PRSP. This rapid bactericidal activity in PRSP is a key to the effectiveness of STFX. Our findings show that beyond inhibition of bacterial replication by blocking their DNA replication pathway and synthesis of proteins, STFX demonstrated characteristics contributing to greater bactericidal activity compared to GRNX. In conclusion, of the newer quinolones, STFX showed the strongest bactericidal activity against S. pneumoniae isolates with mutations in the QRDR which indicates that it may show the most effective clinical utility among the quinolones in respiratory infections.

  7. Bactericidal Effects of Natural Nanotopography of Dragonfly Wing on Escherichia coli.

    Science.gov (United States)

    Bandara, Chaturanga D; Singh, Sanjleena; Afara, Isaac O; Wolff, Annalena; Tesfamichael, Tuquabo; Ostrikov, Kostya; Oloyede, Adekunle

    2017-03-01

    Nanotextured surfaces (NTSs) are critical to organisms as self-adaptation and survival tools. These NTSs have been actively mimicked in the process of developing bactericidal surfaces for diverse biomedical and hygiene applications. To design and fabricate bactericidal topographies effectively for various applications, understanding the bactericidal mechanism of NTS in nature is essential. The current mechanistic explanations on natural bactericidal activity of nanopillars have not utilized recent advances in microscopy to study the natural interaction. This research reveals the natural bactericidal interaction between E. coli and a dragonfly wing's (Orthetrum villosovittatum) NTS using advanced microscopy techniques and proposes a model. Contrary to the existing mechanistic models, this experimental approach demonstrated that the NTS of Orthetrum villosovittatum dragonfly wings has two prominent nanopillar populations and the resolved interface shows membrane damage occurred without direct contact of the bacterial cell membrane with the nanopillars. We propose that the bacterial membrane damage is initiated by a combination of strong adhesion between nanopillars and bacterium EPS layer as well as shear force when immobilized bacterium attempts to move on the NTS. These findings could help guide the design of novel biomimetic nanomaterials by maximizing the synergies between biochemical and mechanical bactericidal effects.

  8. Passive dosing of triclosan in multi-generation tests with copepods - Stable exposure concentrations and effects at the low µg l-1 range

    DEFF Research Database (Denmark)

    Ribbenstedt, Anton; Mustajärvi, Lukas; Breitholtz, Magnus

    2016-01-01

    Ecotoxicity testing is a crucial component of chemical risk assessment. Still, due to methodological difficulties related to controlling exposure concentrations over time, data on long-term effects of organic chemicals at low concentrations are limited. The aim of the present study was therefore...... to test the applicability of passive dosing to maintain stable concentrations of the organochlorine bacteriocide triclosan in the water phase during a 6-week multi-generation population development test with the harpacticoid copepod Nitocra spinipes. Triclosan was loaded into silicone (1000 mg), which...... was used as passive dosing phase in the exposure vials. The distribution ratio for triclosan between silicone and water (Dsilicone-water ) was 10466 ± 1927. A population development test was conducted at three concentration levels of triclosan that were measured to be 3-5 µg L(-1) , 7-11 µg L(-1) and 16...

  9. Triclosan (TCS) and Triclocarban (TCC) cause lifespan reduction and reproductive impairment through oxidative stress-mediated expression of the defensome in the monogonont rotifer (Brachionus koreanus).

    Science.gov (United States)

    Han, Jeonghoon; Won, Eun-Ji; Hwang, Un-Ki; Kim, Il-Chan; Yim, Joung Han; Lee, Jae-Seong

    2016-01-01

    Triclosan (TCS) and Triclocarban (TCC) are used as antimicrobial agents and have been widely dispersed and detected in the marine environment. However, the toxicities of TCS and TCC have been poorly investigated in marine invertebrates. In this study, the effects of TCS and TCC on mortality, population growth, lifespan, and fecundity were examined in the monogonont rotifer (Brachionus koreanus) using cellular ROS levels, GST enzymatic activity, and gene expression of defensomes. The median lethal concentration (LC50) of TCS (393.1μg/L) and TCC (388.1μg/L) was also determined in the same species. In TCS- and TCC-exposed B. koreanus, growth retardation and reduced fecundity were observed and were shown to have a potentially deleterious effect on the life cycle of B. koreanus. In addition, time-dependent increases in ROS content (%) and GST enzymatic activity were shown in response to TCS and TCC exposure. Additionally, transcript levels of detoxification proteins (e.g., CYPs), antioxidant proteins (e.g., GST-sigma, Cu/ZnSOD, CAT), and heat shock proteins (Hsps) were modulated in response to TCS and TCC exposure over a 24h period. Our results indicate that TCS and TCC induce oxidative stress and transcriptional regulation of detoxification, antioxidant, and heat shock proteins, resulting in changes in lifespan and fecundity.

  10. Widespread occurrence of bisphenol A diglycidyl ethers, p-hydroxybenzoic acid esters (parabens), benzophenone type-UV filters, triclosan, and triclocarban in human urine from Athens, Greece.

    Science.gov (United States)

    Asimakopoulos, Alexandros G; Thomaidis, Nikolaos S; Kannan, Kurunthachalam

    2014-02-01

    Biomonitoring of human exposure to bisphenol A diglycidyl ethers (BADGEs; resin coating for food cans), p-hydroxybenzoic acid esters (parabens; preservatives), benzophenone-type UV filters (BP-UV filters; sunscreen agents), triclosan (TCS; antimicrobials), and triclocarban (TCC; antimicrobials) has been investigated in western European countries and North America. Nevertheless, little is known about the exposure of Greek populations to these environmental chemicals. In this study, 100 urine samples collected from Athens, Greece, were analyzed by liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for the determination of total concentrations of five derivatives of BADGEs, six parabens and their metabolite (ethyl-protocatechuate), five derivatives of BP-UV filters, TCS, and TCC. Urinary concentrations of BADGEs, parabens, ethyl-protocatechuate, BP-UV filters, TCS and TCC (on a volume basis) ranged 0.3-20.9 (geometric mean: 0.9), 1.6-1010 (24.2), paraben (100%), bisphenol A bis (2,3-dihydroxypropyl) ether (90%), ethyl paraben (87%), 2,4-dihydroxybenzophenone (78%), propyl paraben (72%), and TCS (71%). Estimated daily intakes (EDIurine), calculated on the basis of the measured urinary concentrations, ranged from 0.023 μg/kg bw/day for Σ5BADGEs to 31.4 μg/kg bw/day for Σ6Parabens.

  11. Effect of ZnO morphology on affecting bactericidal property of ultra high molecular weight polyethylene biocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Rajeev Kumar [Biomaterials Processing and Characterization Laboratory, Indian Institute of Technology Kanpur, Kanpur -208016 (India); Agarwal, Meenakshi [Amity Institute of Nanotechnology, Amity University, Noida, Uttar Pradesh - 201303 (India); Balani, Kantesh, E-mail: kbalani@iitk.ac.in [Biomaterials Processing and Characterization Laboratory, Indian Institute of Technology Kanpur, Kanpur -208016 (India)

    2016-05-01

    Bacterial infection of implants can be controlled by selective trapping of bacteria, followed with consequent killing by targeted antibacterial agents. Herein, the role of various ZnO morphologies, viz. micro-rods (R), nanoparticles (NP), and micro-disks (D) on antibacterial efficacy of ZnO via release of Zn{sup 2+} and H{sub 2}O{sub 2} is assessed, both as isolated powders and via incorporating them in cytocompatible ultra high molecular weight polyethylene (UHMWPE). Though ZnO is antibacterial, interestingly, all ZnO morphologies elicited a supportive growth of gram-negative bacteria (Escherichia coli) in culture medium (until 28–35 μg/ml). But, all ZnO morphologies did elicit bactericidal effect on gram positive bacteria (Staphylococcus aureus or Staphylococcus epidermidis) both in culture medium (for 0–2.5 μg/ml) or when incorporated (5–20 wt.%) into UHMWPE. The bactericidal mechanisms were quantified for various ZnO morphologies via: (i) H{sub 2}O{sub 2} production, (ii) Zn{sup 2+} release, and (iii) the presence of surface oxygen vacancies. On one hand, where only ZnO(NP) elicited release of H{sub 2}O{sub 2} in the absence of light, maximum Zn{sup 2+} release was elicited by ZnO(D). Interestingly, when ZnO is incorporated as reinforcement (5–20 wt.%), its antibacterial action against E. coli was vividly observed due to selective proliferation of bacteria only on friendly UHMWPE matrix. Hence, luring bacteria on affable UHMWPE surface can be complemented with their targeted killing by ZnO present in composite. - Highlights: • The role of ZnO morphology in affecting bactericidal mechanisms • Quantification of Zn{sup 2+} release, H{sub 2}O{sub 2} production and surface oxygen vacancy defects • Inherent resistance by gram negative bacteria at lower ZnO concentrations • Containment of bacteria on polymeric surface and consequent targeted killing by ZnO.

  12. [Bactericidal Activity of Constructed Recombinant Fusion Protein Pheromonicin-CT].

    Science.gov (United States)

    Yu, Huan; Zuo, Yue-wen; Qiu, Xiao-qing

    2015-11-01

    To construct engineering peptide pheromonicin-Clostrzaum tretant krn-ui), and to test its bactericidal activity. We amplified the gene of variable regions from hybridoma cells which secreted monoclonal antibody (mAb) against antigen in the membrane of Clostridium tetani and linked the small antibody mimetic to the channel-forming domain of colicin Ia to create Ph-CT. The Ph-CT was purified by CM sepharose ion-exchange column. Its in vitro antibacterial activity was evaluated by colony culture with different doses of Ph-CT (final concentration 2, 4, 8, and 16 microg/mL,respectively). Then we inoculated culture medium with CT strains and different doses of Ph-CT (final concentration of 4 and 16 microg/mL). The in vivo antibacterial activity of Ph-CT was evaluated by cumulative survival of mice. After 16 hours' anaerobic culture, the mice was treated with filtered CT medium or CT medium. We constructed Ph-CT successfully. CT colonies appeared in the CT medium treated with Ph-CT (2, 4 microg/mL), while no colony appeared in the CT medium treated with Ph-CT (8, 16 microg/mL). All mice survived when they were injected with filtered CT medium treated with Ph-CT (4, 16 microg/mL) and CT medium treated with Ph-CT (16 microg/mL). Three (50%) mice survived when they were injected with CT medium treated with Ph-CT (4 microg/mL). All mice in the control groups died after CT infections. Ph-CT may be of value as antibiotics against Clostridium tetani.

  13. Time-resolved fluoroimmunoassay for bactericidal/permeability-increasing protein

    Directory of Open Access Journals (Sweden)

    J.-O. Häggblom

    1996-01-01

    Full Text Available Bactericidal/permeability-increasing protein (BPI is a cationic antimicrobial protein produced by polymorphonuclear leukocytes, that specifically interacts with and kills Gram-negative bacteria. BPl competes with lipopolysaccharide-binding protein (LBP secreted by liver cells into blood plasma for binding to lipopolysaccharide (LPS and thus reduces the proinflammatory effects of LPS. We have developed a time-resolved fluoroimmunoassay for BPI and measured the concentration of BPI in human serum and plasma samples. The assay is based on a rabbit antibody against recombinant BPI. This antibody specifically adheres to polymorphonuclear leukocytes in immunostained human tissues. The difference in the serum concentration of BPI between unselected hospitalized patients with and without an infection was statistically significant. The mean concentration of BPI in serum samples was 28.3 μg/l (range 1.64–132, S.D. 26.8, n = 83. In contrast, there was no difference between the two groups in the BPI levels in plasma samples. For all individuals tested, BPI levels were consistently higher in plasma samples compared to the matched serum samples. The mean concentration of BPI in plasma samples was 52.3 μg/l (range 0.9–403, S.D. 60.6, n = 90. There was a positive correlation between the concentration of BPI and the white blood cell count as well as between the BPI concentration and C-reactive protein (CRP in serum samples. In conclusion, the present study demonstrates that BPI can be quantified reliably by time-resolved fluoroimmunoassay in human serum samples.

  14. Exopolysaccharide dispelled by calcium hydroxide with volatile vehicles related to bactericidal effect for root canal medication

    Directory of Open Access Journals (Sweden)

    Lei Lei

    Full Text Available ABSTRACT Objective: Enterococcus faecalis is the dominant microbial species responsible for persistent apical periodontitis with ability to deeply penetrate into the dentin. Exopolysaccharides (EPS contribute to the pathogenicity and antibiotic resistance of E. faecalis. Our aim was to investigate the antimicrobial activity of calcium hydroxide (CH, camphorated parachlorophenol (CMCP, and chlorhexidine (CHX against E. faecalis in dentinal tubules. Material and Methods: Decoronated single-canal human teeth and semicylindrical dentin blocks were incubated with E. faecalis for 3 weeks. Samples were randomly assigned to six medication groups for 1 week (n=10 per group: CH + 40% glycerin-water solution (1:1, wt/vol; CMCP; 2% CHX; CH + CMCP (1:1, wt/vol; CH + CMCP (2:3, wt/vol; and saline. Bacterial samples were collected and assayed for colony-forming units. After dentin blocks were split longitudinally, confocal laser scanning microscopy was used to assess the proportion of viable bacteria and EPS production in dentin. Results: CMCP exhibited the best antimicrobial activity, while CH was the least sensitive against E. faecalis (p0.05. CH combined with CMCP inhibited EPS synthesis by E. faecalis, which sensitized biofilms to antibacterial substances. Moreover, increasing concentrations of CMCP decreased EPS matrix formation, which effectively sensitized biofilms to disinfection agents. Conclusion: The EPS matrix dispelled by CH paste with CMCP may be related to its bactericidal effect; the visualization and analysis of EPS formation and microbial colonization in dentin may be a useful approach to verify medicaments for antimicrobial therapy.

  15. The bactericidal effect of dendritic copper microparticles, contained in an alginate matrix, on Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Simon F Thomas

    Full Text Available Although the bactericidal effect of copper has been known for centuries, there is a current resurgence of interest in the use of this element as an antimicrobial agent. During this study the use of dendritic copper microparticles embedded in an alginate matrix as a rapid method for the deactivation of Escherichia coli ATCC 11775 was investigated. The copper/alginate produced a decrease in the minimum inhibitory concentration from free copper powder dispersed in the media from 0.25 to 0.065 mg/ml. Beads loaded with 4% Cu deactivated 99.97% of bacteria after 90 minutes, compared to a 44.2% reduction in viability in the equivalent free copper powder treatment. There was no observed loss in the efficacy of this method with increasing bacterial loading up to 10(6 cells/ml, however only 88.2% of E. coli were deactivated after 90 minutes at a loading of 10(8 cells/ml. The efficacy of this method was highly dependent on the oxygen content of the media, with a 4.01% increase in viable bacteria observed under anoxic conditions compared to a >99% reduction in bacterial viability in oxygen tensions above 50% of saturation. Scanning electron micrographs (SEM of the beads indicated that the dendritic copper particles sit as discrete clusters within a layered alginate matrix, and that the external surface of the beads has a scale-like appearance with dendritic copper particles extruding. E. coli cells visualised using SEM indicated a loss of cellular integrity upon Cu bead treatment with obvious visible blebbing. This study indicates the use of microscale dendritic particles of Cu embedded in an alginate matrix to effectively deactivate E. coli cells and opens the possibility of their application within effective water treatment processes, especially in high particulate waste streams where conventional methods, such as UV treatment or chlorination, are ineffective or inappropriate.

  16. The Bactericidal Effect of Dendritic Copper Microparticles, Contained in an Alginate Matrix, on Escherichia coli

    Science.gov (United States)

    Thomas, Simon F.; Rooks, Paul; Rudin, Fabian; Atkinson, Sov; Goddard, Paul; Bransgrove, Rachel; Mason, Paul T.; Allen, Michael J.

    2014-01-01

    Although the bactericidal effect of copper has been known for centuries, there is a current resurgence of interest in the use of this element as an antimicrobial agent. During this study the use of dendritic copper microparticles embedded in an alginate matrix as a rapid method for the deactivation of Escherichia coli ATCC 11775 was investigated. The copper/alginate produced a decrease in the minimum inhibitory concentration from free copper powder dispersed in the media from 0.25 to 0.065 mg/ml. Beads loaded with 4% Cu deactivated 99.97% of bacteria after 90 minutes, compared to a 44.2% reduction in viability in the equivalent free copper powder treatment. There was no observed loss in the efficacy of this method with increasing bacterial loading up to 106 cells/ml, however only 88.2% of E. coli were deactivated after 90 minutes at a loading of 108 cells/ml. The efficacy of this method was highly dependent on the oxygen content of the media, with a 4.01% increase in viable bacteria observed under anoxic conditions compared to a >99% reduction in bacterial viability in oxygen tensions above 50% of saturation. Scanning electron micrographs (SEM) of the beads indicated that the dendritic copper particles sit as discrete clusters within a layered alginate matrix, and that the external surface of the beads has a scale-like appearance with dendritic copper particles extruding. E. coli cells visualised using SEM indicated a loss of cellular integrity upon Cu bead treatment with obvious visible blebbing. This study indicates the use of microscale dendritic particles of Cu embedded in an alginate matrix to effectively deactivate E. coli cells and opens the possibility of their application within effective water treatment processes, especially in high particulate waste streams where conventional methods, such as UV treatment or chlorination, are ineffective or inappropriate. PMID:24831035

  17. Photopolymerizable phosphate acrylates as comonomers in dental adhesives with or without triclosan monomer units

    Energy Technology Data Exchange (ETDEWEB)

    Melinte, Violeta [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Buruiana, Tinca, E-mail: tbur@icmpp.ro [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Aldea, Horia [Gr. T. Popa University of Medicine and Pharmacy, Faculty of Dentistry, Iasi (Romania); Matiut, Simona [Praxis Medical Investigations, 33 Independence, 700102 Iasi (Romania); Silion, Mihaela; Buruiana, Emil C. [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania)

    2014-01-01

    Phosphate diacrylates (CO-DAP, TMP-DAP) based on castor oil or trimethylolpropane were synthesized and evaluated in dental adhesive formulations in comparison with 3-acryloyloxy-2-hydroxypropyl methacrylate phosphate (AMP-P). In an attempt to promote antibacterial activity, another photopolymerizable monomer (TCS-UMA) containing 5-chloro-2-(2,4-dichlorophenoxy)phenol moiety (triclosan) was prepared and incorporated in adhesive resins. Each of these monomers had a molecular structure confirmed by spectral methods. The photopolymerization rates for monomers (0.063–0.088 s{sup −1}) were lower than those determined in the monomer combinations (0.116–0.158 s{sup −1}) incorporating phosphate diacrylate (11 wt.%), BisGMA (33 wt.%), TEGDMA (10 wt.%), UDMA (10 wt.%) and HEMA (15 wt.%), the degree of conversion varying between 63.4 and 74.5%. The formed copolymers showed high values for water sorption (18.65–57.02 μg/mm{sup 3}) and water solubility (3.51–13.38 μg/mm{sup 3}), and the contact angle was dependent on the presence of CO-DAP (θ{sub F1}: 66.67°), TMP-DAP (θ{sub F2}: 55.05°) or AMP-P (θ{sub F3}: 52.90°) in the photocrosslinked specimens compared to the sample without phosphate monomer (θ{sub F4}: 82.14°). The scanning electron microscopy image of the dentin–resin composite interface after applying our F1 formulation (pH: 4.1) and its light-curing for 20 s supports the evidence of the formation of the hybrid layer with the tooth structure created by self-etching approach, with no gaps or cracks in the adhesive. A comparative analysis of the adhesion achieved with commercial adhesive systems (Single Bond Universal, C-Bond) rather indicates similarities than differences between them. The addition of triclosan methacrylate (1 wt.%) into the formulation inhibited the bacterial growth of the Streptococcus mutans and Escherichia coli in the direct contact area due to the covalently linked antibacterial monomer. - Highlights: • Synthesis of

  18. Effect of ZnO morphology on affecting bactericidal property of ultra high molecular weight polyethylene biocomposite.

    Science.gov (United States)

    Sharma, Rajeev Kumar; Agarwal, Meenakshi; Balani, Kantesh

    2016-05-01

    Bacterial infection of implants can be controlled by selective trapping of bacteria, followed with consequent killing by targeted antibacterial agents. Herein, the role of various ZnO morphologies, viz. micro-rods (R), nanoparticles (NP), and micro-disks (D) on antibacterial efficacy of ZnO via release of Zn(2+) and H2O2 is assessed, both as isolated powders and via incorporating them in cytocompatible ultra high molecular weight polyethylene (UHMWPE). Though ZnO is antibacterial, interestingly, all ZnO morphologies elicited a supportive growth of gram-negative bacteria (Escherichia coli) in culture medium (until 28-35 μg/ml). But, all ZnO morphologies did elicit bactericidal effect on gram positive bacteria (Staphylococcus aureus or Staphylococcus epidermidis) both in culture medium (for 0-2.5 μg/ml) or when incorporated (5-20 wt.%) into UHMWPE. The bactericidal mechanisms were quantified for various ZnO morphologies via: (i) H2O2 production, (ii) Zn(2+) release, and (iii) the presence of surface oxygen vacancies. On one hand, where only ZnO(NP) elicited release of H2O2 in the absence of light, maximum Zn(2+) release was elicited by ZnO(D). Interestingly, when ZnO is incorporated as reinforcement (5-20 wt.%), its antibacterial action against E. coli was vividly observed due to selective proliferation of bacteria only on friendly UHMWPE matrix. Hence, luring bacteria on affable UHMWPE surface can be complemented with their targeted killing by ZnO present in composite.

  19. Salicylic acid and some of its derivatives as antibacterial agents for viscose fabric.

    Science.gov (United States)

    Kantouch, A; El-Sayed, A Atef; Salama, M; El-Kheir, A Abou; Mowafi, S

    2013-11-01

    Salicylic acid and three of its derivatives were used to provide antibacterial properties to viscose fabrics. The four bactericides used were bonded to the viscose fabrics using epichlorohydrin or polymer binders. Optimization of the salicylic acid and its derivatives as well as the concentration of polymers was reported. The ability of the polymer binders to attract and bind the four bactericides was observed. The overall results show that the antibacterial reactivity of salicylic acid and its derivatives are in the following order 5-bromosalicylic acid>salicylic acid>5-chlorosalicylic acid>4-chlorosalicylic acid. Using epichlorohydrin as a binding agent, unfortunately, inhibits the bactericidal activity of the four bactericides. The FTIR study concludes that the reaction between salicylic acid as well as its derivatives with epichlorohydrin takes place through the phenolic group of the acids. The unexpected deterioration in the bactericidal properties of salicylic acid and its derivatives as a result of the treatment with epichlorohydrin could be due to the nature of interaction between the epichlorohydrin molecule and the acids molecules. PVP and PU show superior ability to sustain the four bactericides used even after 10 washing cycles.

  20. Human milk bactericidal properties: effect of lyophilization and relation to maternal factors and milk components.

    Science.gov (United States)

    Salcedo, Jaime; Gormaz, Maria; López-Mendoza, Maria C; Nogarotto, Elisabetta; Silvestre, Dolores

    2015-04-01

    Lyophilization appears to be a viable method for storing human milk, assuring no microbiological contamination and preserving its health benefits and antibacterial properties. The aim of the study is to evaluate and compare the effects of different storage methods (lyophilization and freezing at -20°C and -80°C) and maternal factors (gestational length or time postpartum) upon the microbiological contents and bactericidal activity of human milk. The possible relation between bactericidal activity and the content of certain nutrients and functional components is also investigated. Microbiological content, bactericidal activity, sialic acid, and ganglioside contents, as well as protein, fat, and lactose concentrations were assessed in 125 human milk samples from 65 healthy donors in the Human Milk Bank of La Fe (Valencia, Spain). Lyophilization and storage at -80°C significantly reduced the content of mesophilic aerobic microorganisms and Staphylococcus epidermidis when compared with storage at -20°C. Bactericidal activity was not significantly modified by lyophilization when compared with freezing at either -20°C or -80°C. Bactericidal activity was not correlated with fat, protein, or lactose content, but was significantly correlated to ganglioside content. The bactericidal activity was significantly greater (P milk and in milk from women with term delivery than in milk from early lactation (days 1-7 postpartum) and milk from women with preterm delivery, respectively. Lyophilization and storage at -80°C of human milk yields similar results and are superior to storage at -20C with regard to microbial and bactericidal capacities, being a feasible alternative for human milk banks.

  1. Human Lysozyme Synergistically Enhances Bactericidal Dynamics and Lowers the Resistant Mutant Prevention Concentration for Metronidazole to Helicobacter pylori by Increasing Cell Permeability

    Directory of Open Access Journals (Sweden)

    Xiaolin Zhang

    2016-10-01

    Full Text Available Metronidazole (MNZ is an effective agent that has been employed to eradicate Helicobacter pylori (H. pylori. The emergence of broad MNZ resistance in H. pylori has affected the efficacy of this therapeutic agent. The concentration of MNZ, especially the mutant prevention concentration (MPC, plays an important role in selecting or enriching resistant mutants and regulating therapeutic effects. A strategy to reduce the MPC that can not only effectively treat H. pylori but also prevent resistance mutations is needed. H. pylori is highly resistant to lysozyme. Lysozyme possesses a hydrolytic bacterial cell wall peptidoglycan and a cationic dependent mode. These effects can increase the permeability of bacterial cells and promote antibiotic absorption into bacterial cells. In this study, human lysozyme (hLYS was used to probe its effects on the integrity of the H. pylori outer and inner membranes using as fluorescent probe hydrophobic 1-N-phenyl-naphthylamine (NPN and the release of aspartate aminotransferase. Further studies using a propidium iodide staining method assessed whether hLYS could increase cell permeability and promote cell absorption. Finally, we determined the effects of hLYS on the bactericidal dynamics and MPC of MNZ in H. pylori. Our findings indicate that hLYS could dramatically increase cell permeability, reduce the MPC of MNZ for H. pylori, and enhance its bactericidal dynamic activity, demonstrating that hLYS could reduce the probability of MNZ inducing resistance mutations.

  2. Comparative in vitro activity of oritavancin and other agents against methicillin-susceptible and methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Sweeney, Debora; Shinabarger, Dean L; Arhin, Francis F; Belley, Adam; Moeck, Greg; Pillar, Chris M

    2017-02-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infections constitute a threat to the public health due to their prevalence and associated mortality and morbidity. Several agents have been recently approved to treat MRSA skin infections including lipoglycopeptides (dalbavancin, oritavancin, and telavancin), ceftaroline, and tedizolid. This study compared the MIC, minimum bactericidal concentration (MBC), and time-kill of these agents alongside daptomycin, linezolid, and vancomycin against MRSA (n=15); meropenem, cefazolin, and nafcillin were also included against methicillin-susceptible S. aureus (MSSA [n=12]). MIC and MBC testing was conducted in accordance with Clinical and Laboratory Standards Institute guidelines, and time-kills were evaluated at multiples of the MIC and the free-drug maximum plasma concentration (fCmax) at both standard and high inoculum densities for a subset of MRSA (n=2) and MSSA (n=2). MRSA and MSSA were highly susceptible to all agents, with the lipoglycopeptides having the most potent activity by MIC50/90. All agents excluding tedizolid and linezolid were bactericidal by MBC for MRSA and MSSA, though dalbavancin and telavancin exhibited strain-specific bactericidal activity for MRSA. All agents excluding tedizolid and linezolid were bactericidal by time-kill at their respective fCmax against MRSA and MSSA at standard inoculum density, though oritavancin exhibited the most rapid bactericidal activity. Oritavancin and daptomycin at their respective fCmax maintained similar kill curves at high inoculum density. In contrast, the killing observed with other agents was typically reduced or slowed at high inoculum density. These data demonstrate the rapid bactericidal activity of oritavancin and daptomycin against S. aureus relative to other MRSA agents regardless of bacterial burden.

  3. Degradation of triclocarban by a triclosan-degrading Sphingomonas sp. strain YL-JM2C.

    Science.gov (United States)

    Mulla, Sikandar I; Hu, Anyi; Wang, Yuwen; Sun, Qian; Huang, Shir-Ly; Wang, Han; Yu, Chang-Ping

    2016-02-01

    Bacterial degradation plays a vital role in determining the environmental fate of micropollutants like triclocarban. The mechanism of triclocarban degradation by pure bacterium is not yet explored. The purpose of this study was to identify metabolic pathway that might be involved in bacterial degradation of triclocarban. Triclosan-degrading Sphingomonas sp. strain YL-JM2C was first found to degrade up to 35% of triclocarban (4 mg L(-1)) within 5 d. Gas chromatography-mass spectrometry detected 3,4-dichloroaniline, 4-chloroaniline and 4-chlorocatechol as the major metabolites of the triclocarban degradation. Furthermore, total organic carbon results confirmed that the intermediates, 3,4-dichloroaniline (4 mg L(-1)) and 4-chloroaniline (4 mg L(-1)) could be degraded up to 77% and 80% by strain YL-JM2C within 5 d.

  4. Bactericidal Activity of Octenidine to Various Genospecies of Borrelia burgdorferi, Sensu Lato Spirochetes in Vitro and in Vivo.

    Science.gov (United States)

    Tylewska-Wierzbanowska, Stanisława; Rogulska, Urszula; Lewandowska, Grażyna; Chmielewski, Tomasz

    2017-07-06

    The aim of our studies was to invent a reliable method for detection of the bactericidal activity of disinfectants against Borrelia burgdorferi in suspension (in vitro) and in cell line cultures (in vivo). In the suspension method, 0.01% octenidine at 20°C and 35°C was bactericidal to Borrelia afzeli; Borrelia garini, B. burgdorferi sensu stricto after 5 minutes treatment. Increase of the temperature to 35°C speed up the bactericidal effect to 1 minute. The bactericidal action of octenidine towards B. burgdorferi spirochetes growing in fibroblasts was less effective and needed a longer time to kill them than in the suspension.

  5. Triclosan loaded electrospun nanofibers based on a cyclodextrin polymer and chitosan polyelectrolyte complex.

    Science.gov (United States)

    Ouerghemmi, Safa; Degoutin, Stéphanie; Tabary, Nicolas; Cazaux, Frédéric; Maton, Mickaël; Gaucher, Valérie; Janus, Ludovic; Neut, Christel; Chai, Feng; Blanchemain, Nicolas; Martel, Bernard

    2016-11-20

    This work focuses on the relevance of antibacterial nanofibers based on a polyelectrolyte complex formed between positively charged chitosan (CHT) and an anionic hydroxypropyl betacyclodextrin (CD)-citric acid polymer (PCD) complexing triclosan (TCL). The study of PCD/TCL inclusion complex and its release in dynamic conditions, a cytocompatibility study, and finally the antibacterial activity assessment were studied. The fibers were obtained by electrospinning a solution containing chitosan mixed with PCD/TCL inclusion complex. CHT/TCL and CHT-CD/TCL were also prepared as control samples. The TCL loaded nanofibers were analyzed by Scanning Electron Microscopy (SEM), Fourier Transformed Infrared spectroscopy (FTIR) and X-Ray Diffraction (XRD). Nanofibers stability and swelling behavior in aqueous medium were pH and CHT:PCD weight ratio dependent. Such results confirmed that CHT and PCD interacted through ionic interactions, forming a polyelectrolyte complex. A high PCD content in addition to a thermal post treatment at 90°C were necessary to reach a nanofibers stability during 15days in soft acidic conditions, at pH=5.5. In dynamic conditions (USP IV system), a prolonged release of TCL with a reduced burst effect was observed on CHT-PCD polyelectrolyte complex based fibers compared to CHT-CD nanofibers. These results were confirmed by a microbiology study showing prolonged antibacterial activity of the nanofibers against Escherichia coli and Staphylococcus aureus. Such results could be explained by the fact that the stability of the polyelectrolyte CHT-PCD complex in the nanofibers matrix prevented the diffusion of the PCD/triclosan inclusion complex in the supernatant, on the contrary of the similar system including cyclodextrin in its monomeric form.

  6. The behavior of active bactericidal and antifungal coating under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Gang; Zhang, Xiaodong; Zhao, Yan; Su, Haijia, E-mail: suhj@mail.buct.edu.cn; Tan, Tianwei

    2014-02-15

    In the present paper, the novel active bactericidal and antifungal coatings (ABAC) have been prepared through the immobilization of Fe-doped TiO{sub 2} (anatase) with chitosan. The characterization of ABAC using optical microscope imaging, SEM, AFM and FTIR shows that the Fe doped TiO{sub 2} is embedded into the chitosan coating with favorable dispersion through the hydrogen bonds interaction between chitosan molecules and TiO{sub 2}. The contact angle measurement demonstrated the hydrophilicity of ABAC (θ = 34.5 ± 4.1°). The bactericidal activity of ABAC has been evaluated by inactivating three different test strains: Escherichia coli, Candida albicans and Aspergillus niger which illustrates the apparently higher bactericidal ability than chitosan, Fe-TiO{sub 2} and chitosan/TiO{sub 2} (pure) under visible light irradiation and its bactericidal activity is lasting for at least 24 h. ABAC showed rapid and efficient antibacterial ability for the three tested strains and its antibacterial ratio in 2 h for E. coli, C. albicans and A. niger was 99.9%, 97.0% and 95.0%, respectively. The prepared chitosan/TiO{sub 2} composite emulsion shows favorable storage stability and can be stored up to 1 year without losing its bactericidal activity. ABAC is a low-cost and eco-friendly antibacterial coating products and promising for domestic, medical and industrial applications.

  7. Bactericidal and anti-adhesive properties of culinary and medicinal plants against Helicobacter pylori

    Institute of Scientific and Technical Information of China (English)

    Rachel O'Mahony; Huda Al-Khtheeri; Deepeka Weerasekera; Neluka Fernando; Dino Vaira; John Holton; Christelle Basset

    2005-01-01

    AIM: To investigate the bactericidal and anti-adhesive properties of 25 plants against Helicobacter pylori (H pylori).METHODS: Twenty-five plants were boiled in water to produce aqueous extracts that simulate the effect of cooking. The bactericidal activity of the extracts was assessed by a standard kill-curve with seven strains of H pylori. The anti-adhesive property was assessed by the inhibition of binding of four strains of FITC-labeled H pylori to stomach sections. RESULTS: Of all the plants tested, eight plants, including Bengal quince, nightshade, garlic, dill, black pepper, coriander, fenugreek and black tea, were found to have no bactericidal effect on any of the isolates. Columbo weed, long pepper, parsley, tarragon, nutmeg, yellow-berried nightshade, threadstem carpetweed, sage and cinnamon had bactericidal activities against H pylori, but total inhibition of growth was not achieved in this study. Among the plants that killed H pylori, turmeric was the most efficient, followed by cumin, ginger, chilli, borage, black caraway, oregano and liquorice. Moreover, extracts of turmeric; borage and parsley were able to inhibit the adhesion of H pylori strains to the stomach sections.CONCLUSION: Several plants that were tested in our study had bactericidal and/or anti-adhesive effects on H pylori. Ingestion of the plants with anti-adhesive properties could therefore provide a potent alternative therapy for H pylori infection, which overcomes the problem of resistance associated with current antibiotic treatment.

  8. The behavior of active bactericidal and antifungal coating under visible light irradiation

    Science.gov (United States)

    Xiao, Gang; Zhang, Xiaodong; Zhao, Yan; Su, Haijia; Tan, Tianwei

    2014-02-01

    In the present paper, the novel active bactericidal and antifungal coatings (ABAC) have been prepared through the immobilization of Fe-doped TiO2 (anatase) with chitosan. The characterization of ABAC using optical microscope imaging, SEM, AFM and FTIR shows that the Fe doped TiO2 is embedded into the chitosan coating with favorable dispersion through the hydrogen bonds interaction between chitosan molecules and TiO2. The contact angle measurement demonstrated the hydrophilicity of ABAC (θ = 34.5 ± 4.1°). The bactericidal activity of ABAC has been evaluated by inactivating three different test strains: Escherichia coli, Candida albicans and Aspergillus niger which illustrates the apparently higher bactericidal ability than chitosan, Fe-TiO2 and chitosan/TiO2 (pure) under visible light irradiation and its bactericidal activity is lasting for at least 24 h. ABAC showed rapid and efficient antibacterial ability for the three tested strains and its antibacterial ratio in 2 h for E. coli, C. albicans and A. niger was 99.9%, 97.0% and 95.0%, respectively. The prepared chitosan/TiO2 composite emulsion shows favorable storage stability and can be stored up to 1 year without losing its bactericidal activity. ABAC is a low-cost and eco-friendly antibacterial coating products and promising for domestic, medical and industrial applications.

  9. Bactericidal Mechanisms of Ag2O/TNBs under both Dark and Light Conditions

    Science.gov (United States)

    Jin, Yinjia; Dai, Zhaoyi; Liu, Fei; Kim, Hyunjung; Tong, Meiping; Hou, Yanglong

    2013-04-01

    Ag2O deposited titanium dioxides nanobelts (Ag2O/TNBs) were fabricated and used to investigate the toxic effects on aquatic microorganisms. The disinfection activities of Ag2O/TNBs on two representative bacterial strains: Gram-negative E. coli and Gram-positive B. subtilis, were examined under both dark and light conditions. Ag2O/TNBs exhibited stronger bactericidal activities than TNBs under both dark and light conditions. For both cell types, disinfection effects of Ag2O/TNBs were greater under light conditions relative to those under dark conditions. The bactericidal mechanisms of Ag2O/TNBs under both dark and light conditions were explored. Under dark conditions, neither Ag+ ions released from Ag2O/TNBs nor TNBs contributed to the bactericidal activities of Ag2O/TNBs. Under light conditions, both the released Ag+ions and TNBs yet were found to have contributions to the bactericidal effects of Ag2O/TNBs. Active species (H2O2, ?O2-, ande-) generated by Ag2O/TNBs played important roles in the disinfection processes under both dark and light conditions. Without the presence of active species, the direct contact of Ag2O/TNBs with bacterial cells had no bactericidal effect.

  10. Bactericidal/permeability-increasing protein preserves leukocyte functions after major liver resection.

    Science.gov (United States)

    Wiezer, M J; Meijer, C; Sietses, C; Prins, H A; Cuesta, M A; Beelen, R H; Meijer, S; van Leeuwen, P A

    2000-08-01

    To analyze postoperative leukocyte functions in patients undergoing hemihepatectomy, and to assess the effect of treatment with the endotoxin-neutralizing agent bactericidal/permeability-increasing protein (rBPI21). Extensive liver resection is associated with a high incidence of infectious complications. Because elimination of pathogenic microorganisms occurs mainly by leukocytes, this increased rate of infections is most likely due to an impaired function of these cells. Endotoxin, translocated from the gut into the systemic circulation as a result of increased gut permeability and reduced hepatic clearance function after major liver resection, may play an important role in the impairment of posthepatectomy leukocyte function. To investigate whether hemihepatectomy results in impaired leukocyte functions and to determine the role of endotoxin in this process, leukocyte oxidative burst and leukocyte antigen expression were studied in three groups of patients: patients undergoing a hemihepatectomy and receiving rBPI21 treatment, patients undergoing hemihepatectomy and receiving placebo, and as an extra control group patients undergoing other major abdominal surgeries. Blood samples were collected before surgery, 2 hours after surgery, and at days 1, 2, 5, and 7. Phorbol myristate acetate-stimulated oxidative burst was measured using dihydrorhodamine, and leukocyte surface expression of the antigens CD11b, CD16, and CD14 was investigated by indirect immunofluorescence. Both oxidative burst and membrane surface expression were quantified by flow cytometry. An indication of the antiendotoxin effect of rBPI21 treatment was provided by assessment of plasma lipopolysaccharide binding protein (LBP) levels by enzyme-linked immunosorbent assay. The oxidative burst in the hemihepatectomized patients receiving placebo and the controls increased 2 hours after surgery, whereas it decreased in the rBPI21-treated patients, resulting in significant differences between the groups

  11. Ecotoxicological assessment of the pharmaceutical compound Triclosan to freshwater invertebrates with emphasis to spiked sediment tests; Avaliacao ecotoxicologica do farmaco Triclosan para invertebrados de agua doce com enfase em ensaios com sedimento marcado ('spiked sediment')

    Energy Technology Data Exchange (ETDEWEB)

    Pusceddu, Fabio Hermes

    2009-07-01

    The increasing of Pharmaceutical and Personal Care Products (PPCPs) occurrence in the aquatic environment cause adverse effects on the human health and aquatic communities. The environmental risk of the PPCPs associated with the possibility of synergic effects between PCPPs and the increase of the use of synthetic organic compounds, unchained a great concern on the toxic potential to biota aquatic. Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) is a pharmaceutical compound widely used due your antibacterial mechanism effect, found in at least 932 products such as shampoos, toilet soaps, deodorants, lotions, toothpaste, detergents, socks and underwear, among others. Currently, studies about the Triclosan toxicity in the water and, mainly in the sediment, are poorly. We have the knowledge that the photodegradation of this product results into dichlorodibenzo-p-dioxin, and now it has great discussion on environmental agencies, like EPA, about the release or restriction of this product. The aim of this work is to assess the effects of Triclosan on mortality of insect larvae Chironomus xanthus and mortality and reproduction inhibition of microcrustacea Ceriodaphnia dubia exposed to Triclosan spiked sediments based on standard methods EPA and OECD. The EC50;96H obtained on acute toxicity tests with C. xanthus was 45,26 mg.Kg{sup -1}. The chronic toxicity tests with C. dubia using spiked sediments were performed following the procedure in Burton and MacPherson (1995). A no-observed-effect concentrations and lowest-observed-effect concentration were 5,78 e 6,94 mg.Kg{sup -1}, respectively. (author)

  12. Synergistic bactericidal activity of chlorhexidine-loaded, silver-decorated mesoporous silica nanoparticles.

    Science.gov (United States)

    Lu, Meng-Meng; Wang, Qiu-Jing; Chang, Zhi-Min; Wang, Zheng; Zheng, Xiao; Shao, Dan; Dong, Wen-Fei; Zhou, Yan-Min

    2017-01-01

    Combination of chlorhexidine (CHX) and silver ions could engender synergistic bactericidal effect and improve the bactericidal efficacy. It is highly desired to develop an efficient carrier for the antiseptics codelivery targeting infection foci with acidic microenvironment. In this work, monodisperse mesoporous silica nanoparticle (MSN) nanospheres were successfully developed as an ideal carrier for CHX and nanosilver codelivery through a facile and environmentally friendly method. The CHX-loaded, silver-decorated mesoporous silica nanoparticles (Ag-MSNs@CHX) exhibited a pH-responsive release manner of CHX and silver ions simultaneously, leading to synergistically antibacterial effect against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. Moreover, the effective antibacterial concentration of Ag-MSNs@CHX showed less cytotoxicity on normal cells. Given their synergistically bactericidal ability and good biocompatibility, these nanoantiseptics might have effective and broad clinical applications for bacterial infections.

  13. Effects of refrigeration on the bactericidal activity of human milk: a preliminary study.

    Science.gov (United States)

    Martínez-Costa, Cecilia; Silvestre, María Dolores; López, María Carmen; Plaza, Auxiliadora; Miranda, María; Guijarro, Raquel

    2007-08-01

    This study analyzed the bactericidal activity of human milk and how it is influenced by refrigerated storage. Nine samples of mature human milk were collected and divided into 3 aliquots. One was analyzed immediately, and the other 2 were refrigerated at 4 degrees C to 6 degrees C for 48 and 72 hours, respectively. All of the fresh samples exhibited bactericidal activity with an average value of 83.47% +/- 18.37%. Refrigeration for 48 hours did not cause significant modifications, whereas storage beyond 72 hours significantly lowered the degree of bacteriolysis versus fresh milk. In conclusion, human milk possesses bactericidal activity that remains stable during the first 48 hours of refrigerated storage, but it is significantly reduced beyond 72 hours.

  14. The bactericidal effects of the respiratory burst and the myeloperoxidase system isolated in neutrophil cytoplasts.

    Science.gov (United States)

    Odell, E W; Segal, A W

    1988-10-07

    Neutrophil polymorphonuclear leucocytes kill bacteria by oxygen-dependent and oxygen-independent mechanisms. Many potentially toxic mechanisms have been described, but the complexity of the phagosomal environment and the synergy between oxidative and non-oxidative systems hamper the investigation of individual bactericidal mechanism in whole cells. Neutrophil cytoplasts are greatly depleted of granule proteins and permit the investigation of the bactericidal effects of the respiratory burst in isolation. In this study they have been used to examine the role of the respiratory burst and myeloperoxidase in oxygen-dependent killing of Staphylococcus aureus. Cytoplasts generated oxygen radicals at comparable rates to human neutrophils and phagocytosed but did not kill S. aureus. The selective reconstitution of the myeloperoxidase-hydrogen peroxide-halide system by coating bacteria with myeloperoxidase conferred on cytoplasts the ability to kill intracellular bacteria. However, extracellular killing by diffusible bactericidal factors was not detected in this system.

  15. Bactericidal pathway of Escherichia coli in buffered saline treated with oxygen radicals

    Science.gov (United States)

    Kobayashi, Tsuyoshi; Iwata, Natsumi; Oh, Jun-Seok; Hahizume, Hiroshi; Ohta, Takayuki; Takeda, Keigo; Ishikawa, Kenji; Hori, Masaru; Ito, Masafumi

    2017-04-01

    Bactericidal effects of phosphate buffered saline treated with electrically neutral oxygen radicals on Escherichia coli (E. coli) are studied using an atmospheric pressure radical source and colony counting method. To clarify the bactericidal mechanism, the chemistry in phosphate buffers treated with oxygen radicals with and without saline has been quantitatively investigated using the well-established chemical reporters N,N-diethyl-p-phenylenediamine reagent and Amplex Red for residual chlorine (HClO and ClO-) and hydrogen peroxide (H2O2), respectively. From the results, we have found that the presence of chlorine in the solutions treated with oxygen radicals is the most important factor in the further chemical reactions to generate hypochlorous acid in E. coli death, and H2O2 is also linked to the bactericidal effect via an indirect chemical pathway.

  16. LINE-1 gene hypomethylation and p16 gene hypermethylation in HepG2 cells induced by low-dose and long-term triclosan exposure: The role of hydroxyl group.

    Science.gov (United States)

    Zeng, Liudan; Ma, Huimin; Pan, Shangxia; You, Jing; Zhang, Gan; Yu, Zhiqing; Sheng, Guoying; Fu, Jiamo

    2016-08-01

    Triclosan (TCS), a frequently used antimicrobial agent in pharmaceuticals and personal care products, exerts liver tumor promoter activities in mice. Previous work showed high-dose TCS (1.25-10μM) induced global DNA hypomethylation in HepG2 cells. However, whether or how tumor suppressor gene methylation changed in HepG2 cells after low-dose and long-term TCS exposure is still unknown. We investigate here the effects and mechanisms of DNA methylation of global DNA(GDM), repetitive genes, and liver tumor suppressor gene (p16) after exposing HepG2 cells to low-dose TCS (0.625-5nM)for two weeks using HPLC-MS/MS, Methylight, Q-MSP, Pyrosequencing, and Massarray methods. We found that low-dose TCS exposure decreased repetitive elements LINE-1 methylation levels, but not global DNA methylation, through down-regulating DNMT1 (DNA methyltransferase 1) and MeCP2 (methylated DNA binding domain) expression, and up-regulating 8-hydroxy-2-deoxyguanosine (8-OHdG) levels. Interestingly, low-dose TCS elevated p16 gene methylation and inhibited p16 expression, which were not observed in high-dose (10μM) group. Meanwhile, methyl-triclosan could not induce these two types of DNA methylation changes, suggesting the involvement of hydroxyl in TCS-mediated DNA methylation changes. Collectively, our results suggested low concentrations of TCS adversely affected HepG2 cells through DNA methylation dysregulation, and hydroxyl group in TCS played an important role in the effects. This study provided a better understanding on hepatotoxicity of TCS at environmentally relevant concentrations through epigenetic pathway.

  17. The binding of triclosan to SmeT, the repressor of the multidrug efflux pump SmeDEF, induces antibiotic resistance in Stenotrophomonas maltophilia.

    Directory of Open Access Journals (Sweden)

    Alvaro Hernández

    2011-06-01

    Full Text Available The wide utilization of biocides poses a concern on the impact of these compounds on natural bacterial populations. Furthermore, it has been demonstrated that biocides can select, at least in laboratory experiments, antibiotic resistant bacteria. This situation has raised concerns, not just on scientists and clinicians, but also on regulatory agencies, which are demanding studies on the impact that the utilization of biocides may have on the development on resistance and consequently on the treatment of infectious diseases and on human health. In the present article, we explored the possibility that the widely used biocide triclosan might induce antibiotic resistance using as a model the opportunistic pathogen Stenotrophomonas maltophilia. Biochemical, functional and structural studies were performed, focusing on SmeDEF, the most relevant antibiotic- and triclosan-removing multidrug efflux pump of S. maltophilia. Expression of smeDEF is regulated by the repressor SmeT. Triclosan released SmeT from its operator and induces the expression of smeDEF, thus reducing the susceptibility of S. maltophilia to antibiotics in the presence of the biocide. The structure of SmeT bound to triclosan is described. Two molecules of triclosan were found to bind to one subunit of the SmeT homodimer. The binding of the biocide stabilizes the N terminal domain of both subunits in a conformation unable to bind DNA. To our knowledge this is the first crystal structure obtained for a transcriptional regulator bound to triclosan. This work provides the molecular basis for understanding the mechanisms allowing the induction of phenotypic resistance to antibiotics by triclosan.

  18. Triclosan can select for an AdeIJK-overexpressing mutant of Acinetobacter baumannii ATCC 17978 that displays reduced susceptibility to multiple antibiotics.

    Science.gov (United States)

    Fernando, Dinesh M; Xu, Wayne; Loewen, Peter C; Zhanel, George G; Kumar, Ayush

    2014-11-01

    In order to determine if triclosan can select for mutants of Acinetobacter baumannii ATCC 17978 that display reduced susceptibilities to antibiotics, we isolated a triclosan-resistant mutant, A. baumannii AB042, by serial passaging of A. baumannii ATCC 17978 in growth medium supplemented with triclosan. The antimicrobial susceptibility of AB042 was analyzed by the 2-fold serial dilution method. Expression of five different resistance-nodulation-division (RND) pump-encoding genes (adeB, adeG, adeJ, A1S_2818, and A1S_3217), two outer membrane porin-encoding genes (carO and oprD), and the MATE family pump-encoding gene abeM was analyzed using quantitative reverse transcriptase (qRT) PCR. A. baumannii AB042 exhibited elevated resistance to multiple antibiotics, including piperacillin-tazobactam, doxycycline, moxifloxacin, ceftriaxone, cefepime, meropenem, doripenem, ertapenem, ciprofloxacin, aztreonam, tigecycline, and trimethoprim-sulfamethoxazole, in addition to triclosan. Genome sequencing of A. baumannii AB042 revealed a (116)G→V mutation in fabI, the gene encoding the target enzyme for triclosan. Expression analysis of efflux pumps showed overexpression of the AdeIJK pump, and sequencing of adeN, the gene that encodes the repressor of the adeIJK operon, revealed a 73-bp deletion which would cause a premature termination of translation, resulting in an inactive truncated AdeN protein. This work shows that triclosan can select for mutants of A. baumannii that display reduced susceptibilities to multiple antibiotics from chemically distinct classes in addition to triclosan resistance. This multidrug resistance can be explained by the overexpression of the AdeIJK efflux pump.

  19. The binding of triclosan to SmeT, the repressor of the multidrug efflux pump SmeDEF, induces antibiotic resistance in Stenotrophomonas maltophilia.

    Directory of Open Access Journals (Sweden)

    Alvaro Hernández

    2011-06-01

    Full Text Available The wide utilization of biocides poses a concern on the impact of these compounds on natural bacterial populations. Furthermore, it has been demonstrated that biocides can select, at least in laboratory experiments, antibiotic resistant bacteria. This situation has raised concerns, not just on scientists and clinicians, but also on regulatory agencies, which are demanding studies on the impact that the utilization of biocides may have on the development on resistance and consequently on the treatment of infectious diseases and on human health. In the present article, we explored the possibility that the widely used biocide triclosan might induce antibiotic resistance using as a model the opportunistic pathogen Stenotrophomonas maltophilia. Biochemical, functional and structural studies were performed, focusing on SmeDEF, the most relevant antibiotic- and triclosan-removing multidrug efflux pump of S. maltophilia. Expression of smeDEF is regulated by the repressor SmeT. Triclosan released SmeT from its operator and induces the expression of smeDEF, thus reducing the susceptibility of S. maltophilia to antibiotics in the presence of the biocide. The structure of SmeT bound to triclosan is described. Two molecules of triclosan were found to bind to one subunit of the SmeT homodimer. The binding of the biocide stabilizes the N terminal domain of both subunits in a conformation unable to bind DNA. To our knowledge this is the first crystal structure obtained for a transcriptional regulator bound to triclosan. This work provides the molecular basis for understanding the mechanisms allowing the induction of phenotypic resistance to antibiotics by triclosan.

  20. Bactericidal Effects and Mechanism of Action of Olanexidine Gluconate, a New Antiseptic.

    Science.gov (United States)

    Hagi, Akifumi; Iwata, Koushi; Nii, Takuya; Nakata, Hikaru; Tsubotani, Yoshie; Inoue, Yasuhide

    2015-08-01

    Olanexidine gluconate [1-(3,4-dichlorobenzyl)-5-octylbiguanide gluconate] (development code OPB-2045G) is a new monobiguanide compound with bactericidal activity. In this study, we assessed its spectrum of bactericidal activity and mechanism of action. The minimal bactericidal concentrations of the compound for 30-, 60-, and 180-s exposures were determined with the microdilution method using a neutralizer against 320 bacterial strains from culture collections and clinical isolates. Based on the results, the estimated bactericidal olanexidine concentrations with 180-s exposures were 869 μg/ml for Gram-positive cocci (155 strains), 109 μg/ml for Gram-positive bacilli (29 strains), and 434 μg/ml for Gram-negative bacteria (136 strains). Olanexidine was active against a wide range of bacteria, especially Gram-positive cocci, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, and had a spectrum of bactericidal activity comparable to that of commercial antiseptics, such as chlorhexidine and povidone-iodine. In vitro experiments exploring its mechanism of action indicated that olanexidine (i) interacts with the bacterial surface molecules, such as lipopolysaccharide and lipoteichoic acid, (ii) disrupts the cell membranes of liposomes, which are artificial bacterial membrane models, (iii) enhances the membrane permeability of Escherichia coli, (iv) disrupts the membrane integrity of S. aureus, and (v) denatures proteins at relatively high concentrations (≥160 μg/ml). These results indicate that olanexidine probably binds to the cell membrane, disrupts membrane integrity, and its bacteriostatic and bactericidal effects are caused by irreversible leakage of intracellular components. At relatively high concentrations, olanexidine aggregates cells by denaturing proteins. This mechanism differs slightly from that of a similar biguanide compound, chlorhexidine.

  1. Influence of Rifampin Therapy on Serum Bactericidal Activity in the Presence of Cloxacillin and Vancomycin

    Directory of Open Access Journals (Sweden)

    Andrew MR Mackenzie

    1990-01-01

    Full Text Available In this study the effect of rifampin on serum inhibitory and serum bactericidal titres was examined. Sera were prepared from pooled human serum to contain vancomycin (10 mg/L, cloxacillin (5 mg/L or rifampin (1 mg/L, and the combinations cloxacillin/rifampin and vancomycin/rifampin. These five sera were tested by a microtitre method for serum inhibitory power and serum bactericidal titre against 11 strains of Staphylococcus aureus. A 48 h incubation period was required to detect full colony growth for subculture plates. It was found with all strains that the effect of the addition of rifampin to the other two antibiotics was to increase the serum inhibitory power, lower the serum bactericidal titre, increase the inhibitory/cidal ratio, and slow colony growth on subculture. In the clinical part of the study it was shown that only three of 38 sera (8% from patients receiving betalactam or vanomycin but not rifampin gave an inhibitory/cidal ratio greater than 8, but that nine of 10 sera (90% from patients receiving rifampin in addition to betalactam or vancomycin gave a ratio greater than 8 (P<0.001. The study verified that the effect of rifampin in serum was to increase inhibitory power and decrease bactericidal titre. The clinical significance of these results is not known and it is suggested that a high ratio of inhibitory to bactericidal titre in the presence of rifampin is to be expected, and that a low bactericidal titre under these circumstances is not necessarily an indication to modify therapy.

  2. Morphology-dependent bactericidal activities of Ag/CeO2 catalysts against Escherichia coli.

    Science.gov (United States)

    Wang, Lian; He, Hong; Yu, Yunbo; Sun, Li; Liu, Sijin; Zhang, Changbin; He, Lian

    2014-06-01

    Silver-loaded CeO2 nanomaterials (Ag/CeO2) including Ag/CeO2 nanorods, nanocubes, nanoparticles were prepared with hydrothermal and impregnation methods. Catalytic inactivation of Escherichia coli with Ag/CeO2 catalysts through the formation of reactive oxygen species (ROS) was investigated. For comparison purposes, the bactericidal activities of CeO2 nanorods, nanocubes and nanoparticles were also studied. There was a 3-4 log order improvement in the inactivation of E. coli with Ag/CeO2 catalysts compared with CeO2 catalysts. Temperature-programmed reduction of H2 showed that Ag/CeO2 catalysts had higher catalytic oxidation ability than CeO2 catalysts, which was the reason for that Ag/CeO2 catalysts exhibited stronger bactericidal activities than CeO2 catalysts. Further, the bactericidal activities of CeO2 and Ag/CeO2 depend on their shapes. Results of 5,5-dimethyl-1-pyrroline-N-oxide spin-trapping measurements by electron spin resonance and addition of catalase as a scavenger indicated the formation of OH, O2(-), and H2O2, which caused the obvious bactericidal activity of catalysts. The stronger chemical bond between Ag and CeO2 nanorods led to lower Ag(+) elution concentrations. The toxicity of Ag(+) eluted from the catalysts did not play an important role during the bactericidal process. Experimental results also indicated that Ag/CeO2 induced the production of intracellular ROS and disruption of the cell wall and cell membrane. A possible production mechanism of ROS and bactericidal mechanism of catalytic oxidation were proposed.

  3. Development and evaluation of triclosan loaded poly-ε-caprolactone nanoparticulate system for the treatment of periodontal infections

    Energy Technology Data Exchange (ETDEWEB)

    Aminu, Nafiu; Baboota, Sanjula; Pramod, K. [Jamia Hamdard, Department of Pharmaceutics, Faculty of Pharmacy (India); Singh, Manisha; Dang, Shweta [Jaypee Institute of Information Technology, Department of Biotechnology (India); Ansari, Shahid H. [Jamia Hamdard, Department of Pharmacognosy and Phytochemistry, Faculty of Pharmacy (India); Sahni, Jasjeet K.; Ali, Javed, E-mail: javedaali@yahoo.com [Jamia Hamdard, Department of Pharmaceutics, Faculty of Pharmacy (India)

    2013-11-15

    Periodontal disease affects tooth-supporting structures and nanoparticles (NPs) have been a promising approach for its treatment. The purpose of the study was to develop triclosan-loaded poly-ε-caprolactone (PCL) NPs for the treatment of periodontal infections. Solvent displacement method was used to prepare NPs following Box–Behnken design. The NPs were evaluated with respect to particle size, polydispersity index, surface morphology, zeta potential, thermal properties, in vitro drug release, and cell viability assay. The optimized NPs were in the size range of 180–230 nm with a mean size of 205.61 ± 10.4 nm. Entrapment efficiency (EE) of 91.02 ± 2.4 % was obtained with a drug loading of 21.71 ± 1.3 %. About 97 % of drug was released in vitro after 3 h. NPs demonstrated almost 100 % cell viability in L929 cell lines. Shelf life of the nanoparticles was 17.07 months. PCL affected particle size whereas triclosan affected loading and EE. The optimized NPs were spherical with smooth surface and exhibited biphasic in vitro release pattern. NPs had optimum zeta potential and PDI and were stable on storage. Absence of cytotoxicity of NPs to L929 cells indicated its safety. Triclosan-loaded PCL nanoparticles could thus serve as a novel colloidal drug delivery system against periodontal infections.

  4. Development and evaluation of triclosan loaded poly-ɛ-caprolactone nanoparticulate system for the treatment of periodontal infections

    Science.gov (United States)

    Aminu, Nafiu; Baboota, Sanjula; Pramod, K.; Singh, Manisha; Dang, Shweta; Ansari, Shahid H.; Sahni, Jasjeet K.; Ali, Javed

    2013-11-01

    Periodontal disease affects tooth-supporting structures and nanoparticles (NPs) have been a promising approach for its treatment. The purpose of the study was to develop triclosan-loaded poly-ɛ-caprolactone (PCL) NPs for the treatment of periodontal infections. Solvent displacement method was used to prepare NPs following Box-Behnken design. The NPs were evaluated with respect to particle size, polydispersity index, surface morphology, zeta potential, thermal properties, in vitro drug release, and cell viability assay. The optimized NPs were in the size range of 180-230 nm with a mean size of 205.61 ± 10.4 nm. Entrapment efficiency (EE) of 91.02 ± 2.4 % was obtained with a drug loading of 21.71 ± 1.3 %. About 97 % of drug was released in vitro after 3 h. NPs demonstrated almost 100 % cell viability in L929 cell lines. Shelf life of the nanoparticles was 17.07 months. PCL affected particle size whereas triclosan affected loading and EE. The optimized NPs were spherical with smooth surface and exhibited biphasic in vitro release pattern. NPs had optimum zeta potential and PDI and were stable on storage. Absence of cytotoxicity of NPs to L929 cells indicated its safety. Triclosan-loaded PCL nanoparticles could thus serve as a novel colloidal drug delivery system against periodontal infections.

  5. The nature of inherent bactericidal activity: insights from the nanotopology of three species of dragonfly

    Science.gov (United States)

    Mainwaring, David E.; Nguyen, Song Ha; Webb, Hayden; Jakubov, Timur; Tobin, Mark; Lamb, Robert N.; Wu, Alex H.-F.; Marchant, Richard; Crawford, Russell J.; Ivanova, Elena P.

    2016-03-01

    While insect wings are widely recognised as multi-functional, recent work showed that this extends to extensive bactericidal activity brought about by cell deformation and lysis on the wing nanotopology. We now quantitatively show that subtle changes to this topography result in substantial changes in bactericidal activity that are able to span an order of magnitude. Notably, the chemical composition of the lipid nanopillars was seen by XPS and synchrotron FTIR microspectroscopy to be similar across these activity differences. Modelling the interaction between bacterial cells and the wing surface lipids of 3 species of dragonflies, that inhabit similar environments, but with distinctly different behavioural repertoires, provided the relationship between surface structure and antibacterial functionality. In doing so, these principal behavioural patterns correlated with the demands for antimicrobial efficiency dictated by differences in their foraging strategies. This work now reveals a new feature in the design elegance of natural multi-functional surfaces as well providing insights into the bactericidal mechanism underlying inherently antimicrobial materials, while suggesting that nanotopology is related to the evolutionary development of a species through the demands of its behavioural repertoire. The underlying relationship between the processes of wetting, adhesion and capillarity of the lipid nanopillars and bactericidal efficiency suggests new prospects for purely mechano-responsive antibacterial surfaces.While insect wings are widely recognised as multi-functional, recent work showed that this extends to extensive bactericidal activity brought about by cell deformation and lysis on the wing nanotopology. We now quantitatively show that subtle changes to this topography result in substantial changes in bactericidal activity that are able to span an order of magnitude. Notably, the chemical composition of the lipid nanopillars was seen by XPS and synchrotron

  6. Use of lyophilized skin for testing the bactericidal activity of teat disinfectants.

    Science.gov (United States)

    Bramley, A J; Hogben, E M

    1983-02-01

    The bactericidal activities of various concentrations of 3 disinfectants commonly used for teat disinfection were compared in vitro using small discs of pig skin previously contaminated with Staphylococcus aureus. Solutions containing 40 g/l Na hypochlorite, 25 or 50 g/l chlorhexidine digluconate or iodophor containing 5 g/l iodine were found to have equivalent or superior bactericidal activity to a solution containing 10 g/l Na hypochlorite. This in vitro technique offers a convenient alternative to in vivo tests for teat disinfectants and with minor modifications could be applicable to the testing of skin antiseptics in general.

  7. INVOLVEMENT OF BACTERICIDAL FACTORS FROM THROMBIN-STIMULATED PLATELETS IN CLEARANCE OF ADHERENT VIRIDANS STREPTOCOCCI IN EXPERIMENTAL INFECTIVE ENDOCARDITIS

    NARCIS (Netherlands)

    VANDERWERFF, J; ZAAT, SAJ; JOLDERSMA, W; HESS, J

    1995-01-01

    Platelets activated with thrombin release bactericidal factors. We studied the role of the susceptibility of viridans streptococci to these bactericidal factors in the development of infective endocarditis (IE). By using the experimental endocarditis rabbit model, the initial adherence and the devel

  8. Structure-activity studies of the inhibition of FabI, the enoyl reductase from Escherichia coli, by triclosan: kinetic analysis of mutant FabIs.

    Science.gov (United States)

    Sivaraman, Sharada; Zwahlen, Jacque; Bell, Alasdair F; Hedstrom, Lizbeth; Tonge, Peter J

    2003-04-22

    Triclosan, a common antibacterial additive used in consumer products, is an inhibitor of FabI, the enoyl reductase enzyme from type II bacterial fatty acid biosynthesis. In agreement with previous studies [Ward, W. H., Holdgate, G. A., Rowsell, S., McLean, E. G., Pauptit, R. A., Clayton, E., Nichols, W. W., Colls, J. G., Minshull, C. A., Jude, D. A., Mistry, A., Timms, D., Camble, R., Hales, N. J., Britton, C. J., and Taylor, I. W. (1999) Biochemistry 38, 12514-12525], we report here that triclosan is a slow, reversible, tight binding inhibitor of the FabI from Escherichia coli. Triclosan binds preferentially to the E.NAD(+) form of the wild-type enzyme with a K(1) value of 23 pM. In agreement with genetic selection experiments [McMurry, L. M., Oethinger, M., and Levy, S. B. (1998) Nature 394, 531-532], the affinity of triclosan for the FabI mutants G93V, M159T, and F203L is substantially reduced, binding preferentially to the E.NAD(+) forms of G93V, M159T, and F203L with K(1) values of 0.2 microM, 4 nM, and 0.9 nM, respectively. Triclosan binding to the E.NADH form of F203L can also be detected and is defined by a K(2) value of 51 nM. We have also characterized the Y156F and A197M mutants to compare and contrast the binding of triclosan to InhA, the homologous enoyl reductase from Mycobacterium tuberculosis. As observed for InhA, Y156F FabI has a decreased affinity for triclosan and the inhibitor binds to both E.NAD(+) and E.NADH forms of the enzyme with K(1) and K(2) values of 3 and 30 nM, respectively. The replacement of A197 with Met has no impact on triclosan affinity, indicating that differences in the sequence of the conserved active site loop cannot explain the 10000-fold difference in affinities of FabI and InhA for triclosan.

  9. Synthesis of silver nanoparticles by endosymbiont Pseudomonas fluorescens CA 417 and their bactericidal activity.

    Science.gov (United States)

    Syed, Baker; M N, Nagendra Prasad; B L, Dhananjaya; K, Mohan Kumar; S, Yallappa; S, Satish

    2016-12-01

    The present study emphasizes on biogenic synthesis of silver nanoparticles and their bactericidal activity against human and phytopathogens. Nanoparticle synthesis was performed using endosymbiont Pseudomonas fluorescens CA 417 inhabiting Coffea arabica L. Synthesized nanoparticles were characterized using hyphenated spectroscopic techniques such as UV-vis spectroscopy which revealed maximum absorption 425nm. Fourier transform infrared spectroscopy (FTIR) analysis revealed the possible functional groups mediating and stabilizing silver nanoparticles with predominant peaks occurring at 3346 corresponding to hydroxyl group, 1635 corresponding carbonyl group and 680 to aromatic group. X-ray diffraction (XRD) analysis revealed the Bragg's diffraction pattern with distinct peaks at 38° 44°, 64° and 78° revealing the face-centered cubic (fcc) metallic crystal corresponding to the (111), (200), (220) and (311) facets of the crystal planes at 2θ angle. The energy dispersive X-ray spectroscopy (EDS) analysis revealed presence of high intense absorption peak at 3keV is a typical characteristic of nano-crystalline silver which confirmed the presence of elemental silver. TEM analysis revealed the size of the nanoparticles to be in the range 5-50nm with polydisperse nature of synthesized nanoparticles bearing myriad shapes. The particle size determined by Dynamic light scattering (DLS) method revealed average size to be 20.66nm. The synthesized silver nanoparticles exhibited significant antibacterial activity against panel of test pathogens. The results showed Klebsiella pneumoniae (MTCC 7407) and Xanthomonas campestris to be more sensitive among the test human pathogen and phyto-pathogen respectively. The study also reports synergistic effect of silver nanoparticles in combination with kanamycin which displayed increased fold activity up to 58.3% against Klebsiella pneumoniae (MTCC 7407). The results of the present investigation are promising enough and attribute towards

  10. Bactericidal and wound-healing properties of sodium hypochlorite solutions: the 1991 Lindberg Award.

    Science.gov (United States)

    Heggers, J P; Sazy, J A; Stenberg, B D; Strock, L L; McCauley, R L; Herndon, D N; Robson, M C

    1991-01-01

    Toxic effects of sodium hypochlorite on wound healing elements have been confined to a restricted range of sodium hypochlorite concentrations. We investigated concentrations of sodium hypochlorite for antibacterial activity and tissue toxicity at varying time intervals. We attempted to find the efficacious therapeutic concentration that was both microbicidal and nontoxic. Gram-negative and gram-positive isolates (0.1/ml of 1 x 10(8)/ml) were introduced into various concentrations of buffered and unbuffered sodium hypochlorite solutions for determinations of bactericidal activity at 5-, 10-, 15-, and 30-minute intervals. Concentrations of sodium hypochlorite were 0.25%, 0.025%, and 0.0125%. In vitro assays with fibroblasts at the same concentrations were also performed to determine toxicity at the same time intervals. An in vivo incisional model was also used to determine the effects of sodium hypochlorite therapy on wound healing. Bactericidal effects were observed for concentrations as low as 0.025%. Tissue toxicity, both in vitro and in vivo, was observed at concentrations of 0.25% but not at a concentration of 0.025%. Although concentrations below this level were nontoxic, they were not bactericidal. Therefore a modified "Dakin's" solution at a concentration of 0.025% is therapeutically efficacious as a fluid dressing, since it preserves bactericidal properties and eliminates the detrimental potential on wound healing.

  11. Characterization and Activity of an Immobilized Antimicrobial Peptide Containing Bactericidal PEG-Hydrogel

    NARCIS (Netherlands)

    Cleophas, Rik T. C.; Sjollema, Jelmer; Busscher, Henk J.; Kruijtzer, John A. W.; Liskamp, Rob M. J.

    2014-01-01

    A single step immobilization-polymerization strategy of a highly active antimicrobial peptide into a soft hydrogel network on a poly(ethylene terephthalate) surface using thiol-ene chemistry is described. The bactericidal hydrogel was molecularly characterized via Coomassie and Lowry assay protein s

  12. Peroxiredoxin-3 Is Involved in Bactericidal Activity through the Regulation of Mitochondrial Reactive Oxygen Species

    Science.gov (United States)

    Lee, Sena; Wi, Sae Mi; Min, Yoon

    2016-01-01

    Peroxiredoxin-3 (Prdx3) is a mitochondrial protein of the thioredoxin family of antioxidant peroxidases and is the principal peroxidase responsible for metabolizing mitochondrial hydrogen peroxide. Recent reports have shown that mitochondrial reactive oxygen species (mROS) contribute to macrophage-mediated bactericidal activity in response to Toll-like receptors. Herein, we investigated the functional effect of Prdx3 in bactericidal activity. The mitochondrial localization of Prdx3 in HEK293T cells was confirmed by cell fractionation and confocal microscopy analyses. To investigate the functional role of Prdx3 in bactericidal activity, Prdx3-knockdown (Prdx3KD) THP-1 cells were generated. The mROS levels in Prdx3KD THP-1 cells were significantly higher than those in control THP-1 cells. Moreover, the mROS levels were markedly increased in response to lipopolysaccharide. Notably, the Salmonella enterica serovar Typhimurium infection assay revealed that the Prdx3KD THP-1 cells were significantly resistant to S. Typhimurium infection, as compared with control THP-1 cells. Taken together, these results indicate that Prdx3 is functionally important in bactericidal activity through the regulation of mROS. PMID:28035213

  13. Integrated antifouling and bactericidal polymer membranes through bioinspired polydopamine/poly(N-vinyl pyrrolidone) coating

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianghong [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Faculty of Materials Science and Engineering, Hubei University, Wuhan 430062 (China); Yuan, Shuaishuai [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Shi, Dean, E-mail: deanshi2012@yahoo.com [Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Faculty of Materials Science and Engineering, Hubei University, Wuhan 430062 (China); Yang, Yingkui; Jiang, Tao [Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Faculty of Materials Science and Engineering, Hubei University, Wuhan 430062 (China); Yan, Shunjie; Shi, Hengchong [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Luan, Shifang, E-mail: sfluan@ciac.ac.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yin, Jinghua [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2016-07-01

    Graphical abstract: - Highlights: • Antifouling and bactericidal capabilities were facilely integrated into a surface via bioinspired coating. • The modification technique was very facile and universal to different types of substrate materials. • The integrated antifouling and bactericidal surfaces have great potential in wound dressing applications. - Abstract: Polypropylene (PP) non-woven has been widely used as wound dressing; however, the hydrophobic nature of PP can initiate bacterial attachment and subsequent biofilm formation. Herein, we propose a facile approach to functionalize PP non-woven with poly(ethylene glycol) (PEG) and poly(N-vinyl pyrrolidone)-iodine complex (PVP-I). PVP and PEG were successively tethered onto PP non-woven surface via versatile bioinspired dopamine (DA) chemistry, followed by complexing iodine with PVP moieties. It was demonstrated through the field emission scanning electron microscope (SEM) and spread plate method that the as-modified PP non-woven integrated both antifouling property of PEG for suppressing bacterial adhesion, and bactericidal property of PVP-I for killing the few adherent bacteria. Meanwhile, it could greatly resist platelet and red blood cell adhesion. The integrated antifouling and bactericidal PP non-woven surfaces might have great potential in various wound dressing applications.

  14. Predicting of bactericidal activity of chemical disinfectants using disinfection activity coefficient of solution

    OpenAIRE

    Gjorgjeska, Biljana

    2011-01-01

    There is the need for defining standard technique for quantitative determination of bactericidal activity of chemical disinfectant substances, as well as the need for defining parameter for comparing various chemical disinfectants. The methods which are usually used for evaluation of antiseptic activity of disinfectant aqueous solutions are microbiological.

  15. DEVELOPMENT OF INDUSTRIAL TECHNOLOGY BACTERICIDAL PATCH OF THICK OAK BARK EXTRACT

    Directory of Open Access Journals (Sweden)

    N. V. Hohlenkova

    2013-06-01

    Full Text Available Theoretically and experimentally efficient technology of bactericidal patch of thick oak bark extract in LLC "ВUС Sarepta-mediplast" have been substantiated. According to the research critical parameters of production were identified, established their permissible deviations.

  16. Selenium-mediated protection in reversing the sensitivity of bacterium to the bactericidal antibiotics.

    Science.gov (United States)

    Li, Zhonglei; Tan, Jun; Shao, Lei; Dong, Xiaojing; Ye, Richard D; Chen, Daijie

    2017-05-01

    Inducing production of damaging reactive oxygen species (ROS) is an important criterion to distinguish the bactericidal antibiotics from bacteriostatic antibiotics. Selenoenzymes were generally recognized to be a powerful antioxidant capable of scavenging free radicals, protecting the cells from the harmful effects of ROS. Therefore, the present study was carried out to investigate the selenium (Se)-mediated protection in reversing antibiotic sensitivity and the role of selenoenzymes in alleviating the negative effects of oxidative stress. The cellular antioxidant activity of Se-enriched bacteria was analyzed, as well as intracellular ROS production and elimination when Se-enriched bacteria in the presence of various antibiotics. Compared to complete inhibition of the parental strain by bactericidal antibiotics, it only exhibited slight and reversible inhibition of Se-enriched Escherichia coli ATCC25922 and Staphylococcus aureus ATCC25923 at the same conditions, which indicated that intracellular selenium provided substantial protection against antibiotics. ROS generation caused by bactericidal antibiotics was confirmed by fluorescence spectrophotometry using 2', 7'-dichloro- uorescein diacetate (DCFH-DA) as substrate. The time course experiments of pretreatment with selenium showed significant decrease of ROS level at 2h. In summary, the present study provides experimental evidence supporting selenoenzymes has good scavenging effect to ROS and can protect bacteria from oxidative stress injury induced by bactericidal antibiotics. Copyright © 2017 Elsevier GmbH. All rights reserved.

  17. Increased bactericidal activity of colistin on Pseudomonas aeruginosa biofilms in anaerobic conditions

    DEFF Research Database (Denmark)

    Mette, Kolpen; Appeldorff, Cecilie F; Brandt, Sarah;

    2016-01-01

    that production of OH⋅ may not contribute significantly to the bactericidal activity of colistin on P. aeruginosa biofilm. Thus, we investigated the effect of colistin treatment on biofilm of wildtype PAO1, a catalase deficient mutant (ΔkatA) and a colistin resistant CF isolate cultured in microtiter plates...

  18. Influence of nano-MgO particle size on bactericidal action against Bacillus subtilis var. niger

    Institute of Scientific and Technical Information of China (English)

    HUANG Lei; LI Dianqing; LIN Yanjun; David G.Evans; DUAN Xue

    2005-01-01

    Nano-MgO with various particle sizes, synthesized by different methods using Mg(NO3)2·6H2O, Na2CO3, Na2SO4, urea and ammonia solution as reactants, was used to carry out bactericidal experiments on Bacillus subtilis var. niger. The results were compared with the effect of TiO2, a common kind of photocatalytic material. The materials were characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), low temperature N2 adsorption-desorption measurements and FT-IR, and the results showed that the bactericidal ability of MgO increases with decreasing particle size. Nano-MgO and an interior wall-paint containing the material have better bactericidal effects than nono-TiO2 in both presence and absence of light. The bactericidal mechanism is discussed. The surface of MgO can generate high concentrations of which is highly active and can react with the peptide linkages in the coating walls of the spores. The spores are destroyed by the resulting damage to their structure.

  19. Anti-adherence and bactericidal activity of sphingolipids against Streptococcus mutans

    NARCIS (Netherlands)

    Cukkemane, N.; Bikker, F.J.; Nazmi, K.; Brand, H.S.; Sotres, J.; Lindh, L.; Arnebrant, T.; Veerman, E.C.I.

    2015-01-01

    This study evaluated the anti-biofilm activity of sphingosine, phytosphingosine (PHS), and sphinganine for: (i) anti-adherence activity on hydroxyapatite (HA) surfaces; and (ii) bactericidal activity on different Streptococcus mutans phenotypes (i.e. planktonic cells and cells from a disrupted biofi

  20. Characterization and activity of an immobilized antimicrobial peptide containing bactericidal PEG-hydrogel

    NARCIS (Netherlands)

    Cleophas, Rik T C; Sjollema, Jelmer; Busscher, Henk J; Kruijtzer, John A W; Liskamp, Rob M J

    2014-01-01

    A single step immobilization-polymerization strategy of a highly active antimicrobial peptide into a soft hydrogel network on a poly(ethylene terephthalate) surface using thiol-ene chemistry is described. The bactericidal hydrogel was molecularly characterized via Coomassie and Lowry assay protein s

  1. Increased bactericidal activity of colistin on Pseudomonas aeruginosa biofilms in anaerobic conditions

    DEFF Research Database (Denmark)

    Kolpen, Mette; Appeldorff, Cecilie F.; Brandt, Sarah;

    2016-01-01

    that production of OH˙may not contribute significantly to the bactericidal activity of colistin on P. aeruginosa biofilm. Thus, we investigated the effect of colistin treatment on biofilm of wild-type PAO1, a catalase-deficient mutant (katA) and a colistin-resistant CF isolate cultured in microtiter plates...

  2. Synergistic bactericidal activity of Ag-TiO₂ nanoparticles in both light and dark conditions.

    Science.gov (United States)

    Li, Minghua; Noriega-Trevino, Maria Eugenia; Nino-Martinez, Nereyda; Marambio-Jones, Catalina; Wang, Jinwen; Damoiseaux, Robert; Ruiz, Facundo; Hoek, Eric M V

    2011-10-15

    High-throughput screening was employed to evaluate bactericidal activities of hybrid Ag-TiO₂ nanoparticles comprising variations in TiO₂ crystalline phase, Ag content, and synthesis method. Hybrid Ag-TiO₂ nanoparticles were prepared by either wet-impregnation or UV photo deposition onto both Degussa P25 and DuPont R902 TiO₂ nanoparticles. The presence of Ag was confirmed by ICP, TEM, and XRD analysis. The size of Ag nanoparticles formed on anatase/rutile P25 TiO₂ nanoparticles was smaller than those formed on pure rutile R902. When activated by UV light, all hybrid Ag-TiO₂ nanoparticles exhibited stronger bactericidal activity than UV alone, Ag/UV, or UV/TiO₂. For experiments conducted in the dark, bactericidal activity of Ag-TiO₂ nanoparticles was greater than either bare TiO₂ (inert) or pure Ag nanoparticles, suggesting that the hybrid materials produced a synergistic antibacterial effect unrelated to photoactivity. Moreover, less Ag(+) dissolved from Ag-TiO₂ nanoparticles than from Ag nanoparticles, indicating the antibacterial activities of Ag-TiO₂ was not only caused by releasing of toxic metal ions. It is clear that nanotechnology can produce more effective bactericides; however, the challenge remains to identify practical ways to take advantage of these exciting new material properties.

  3. Bactericidal Action of Photo-Irradiated Aqueous Extracts from the Residue of Crushed Grapes from Winemaking.

    Science.gov (United States)

    Tsukada, Mana; Sheng, Hong; Tada, Mika; Mokudai, Takayuki; Oizumi, Satomi; Kamachi, Toshiaki; Niwano, Yoshimi

    2016-01-01

    Our previous studies revealed that photo-irradiation of polyphenols could exert bactericidal action via reactive oxygen species (ROS). In the present study, the photo-irradiation-induced bactericidal activity of the aqueous extract from the residue of crushed grapes from winemaking was investigated in relation to ROS formation. Staphylococcus aureus suspended in the extract was irradiated with LED light at 400 nm. This solution killed the bacteria, and a 3-4 log and a >5-log reduction of the viable counts were observed within 10 and 20 min, respectively. LED light irradiation alone also killed the bacteria, but the viable counts were 2-4 log higher than those of the photo-irradiated extract. In contrast, almost no change occurred in the suspension without LED irradiation. When hydroxyl radical scavengers were added to the suspension, the bactericidal effect of the photo-irradiated extract was attenuated. Furthermore, electron spin resonance analysis demonstrated that hydroxyl radicals were generated by the photo-irradiation of the extract. The present study suggests that polyphenolic compounds in the extract exert bactericidal activity via hydroxyl radical formation upon photo-irradiation.

  4. The nature of inherent bactericidal activity: insights from the nanotopology of three species of dragonfly.

    Science.gov (United States)

    Mainwaring, David E; Nguyen, Song Ha; Webb, Hayden; Jakubov, Timur; Tobin, Mark; Lamb, Robert N; Wu, Alex H-F; Marchant, Richard; Crawford, Russell J; Ivanova, Elena P

    2016-03-28

    While insect wings are widely recognised as multi-functional, recent work showed that this extends to extensive bactericidal activity brought about by cell deformation and lysis on the wing nanotopology. We now quantitatively show that subtle changes to this topography result in substantial changes in bactericidal activity that are able to span an order of magnitude. Notably, the chemical composition of the lipid nanopillars was seen by XPS and synchrotron FTIR microspectroscopy to be similar across these activity differences. Modelling the interaction between bacterial cells and the wing surface lipids of 3 species of dragonflies, that inhabit similar environments, but with distinctly different behavioural repertoires, provided the relationship between surface structure and antibacterial functionality. In doing so, these principal behavioural patterns correlated with the demands for antimicrobial efficiency dictated by differences in their foraging strategies. This work now reveals a new feature in the design elegance of natural multi-functional surfaces as well providing insights into the bactericidal mechanism underlying inherently antimicrobial materials, while suggesting that nanotopology is related to the evolutionary development of a species through the demands of its behavioural repertoire. The underlying relationship between the processes of wetting, adhesion and capillarity of the lipid nanopillars and bactericidal efficiency suggests new prospects for purely mechano-responsive antibacterial surfaces.

  5. Photopolymerizable phosphate acrylates as comonomers in dental adhesives with or without triclosan monomer units.

    Science.gov (United States)

    Melinte, Violeta; Buruiana, Tinca; Aldea, Horia; Matiut, Simona; Silion, Mihaela; Buruiana, Emil C

    2014-01-01

    Phosphate diacrylates (CO-DAP, TMP-DAP) based on castor oil or trimethylolpropane were synthesized and evaluated in dental adhesive formulations in comparison with 3-acryloyloxy-2-hydroxypropyl methacrylate phosphate (AMP-P). In an attempt to promote antibacterial activity, another photopolymerizable monomer (TCS-UMA) containing 5-chloro-2-(2,4-dichlorophenoxy)phenol moiety (triclosan) was prepared and incorporated in adhesive resins. Each of these monomers had a molecular structure confirmed by spectral methods. The photopolymerization rates for monomers (0.063-0.088s(-1)) were lower than those determined in the monomer combinations (0.116-0.158s(-1)) incorporating phosphate diacrylate (11wt.%), BisGMA (33wt.%), TEGDMA (10wt.%), UDMA (10wt.%) and HEMA (15wt.%), the degree of conversion varying between 63.4 and 74.5%. The formed copolymers showed high values for water sorption (18.65-57.02μg/mm(3)) and water solubility (3.51-13.38μg/mm(3)), and the contact angle was dependent on the presence of CO-DAP (θF1: 66.67°), TMP-DAP (θF2: 55.05°) or AMP-P (θF3: 52.90°) in the photocrosslinked specimens compared to the sample without phosphate monomer (θF4: 82.14°). The scanning electron microscopy image of the dentin-resin composite interface after applying our F1 formulation (pH: 4.1) and its light-curing for 20s supports the evidence of the formation of the hybrid layer with the tooth structure created by self-etching approach, with no gaps or cracks in the adhesive. A comparative analysis of the adhesion achieved with commercial adhesive systems (Single Bond Universal, C-Bond) rather indicates similarities than differences between them. The addition of triclosan methacrylate (1wt.%) into the formulation inhibited the bacterial growth of the Streptococcus mutans and Escherichia coli in the direct contact area due to the covalently linked antibacterial monomer.

  6. Removal of triclosan via peroxidases-mediated reactions in water: Reaction kinetics, products and detoxification

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jianhua; Peng, Jianbiao [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China); Zhang, Ya [Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection of the People’s Republic of China, Nanjing 210042 (China); Ji, Yuefei [College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095 (China); Shi, Huanhuan; Mao, Liang [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China); Gao, Shixiang, E-mail: ecsxg@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China)

    2016-06-05

    Highlights: • Enzymatic treatment of triclosan in water by soybean and horseradish peroxidases. • pH, H{sub 2}O{sub 2} concentration and enzyme dosage affected the removal efficiency of TCS. • The removal of TCS by SBP was more efficient than that of HRP. • K{sub CAT} and K{sub CAT}/K{sub M} values for SBP toward TCS were much higher than those for HRP. • Polymers formed via radical coupling mechanism were nontoxic to the growth of alga. - Abstract: This study investigated and compared reaction kinetics, product characterization, and toxicity variation of triclosan (TCS) removal mediated by soybean peroxidase (SBP), a recognized potential peroxidase for removing phenolic pollutants, and the commonly used horseradish peroxidase (HRP) with the goal of assessing the technical feasibility of SBP-catalyzed removal of TCS. Reaction conditions such as pH, H{sub 2}O{sub 2} concentration and enzyme dosage were found to have a strong influence on the removal efficiency of TCS. SBP can retain its catalytic ability to remove TCS over broad ranges of pH and H{sub 2}O{sub 2} concentration, while the optimal pH and H{sub 2}O{sub 2} concentration were 7.0 and 8 μM, respectively. 98% TCS was removed with only 0.1 U mL{sup −1} SBP in 30 min reaction time, while an HRP dose of 0.3 U mL{sup −1} was required to achieve the similar conversion. The catalytic performance of SBP towards TCS was more efficient than that of HRP, which can be explained by catalytic rate constant (K{sub CAT}) and catalytic efficiency (K{sub CAT}/K{sub M}) for the two enzymes. MS analysis in combination with quantum chemistry computation showed that the polymerization products were generated via C−C and C−O coupling pathways. The polymers were proved to be nontoxic through growth inhibition of green alga (Scenedesmus obliquus). Taking into consideration of the enzymatic treatment cost, SBP may be a better alternative to HRP upon the removal and detoxification of TCS in water

  7. Bactericidal effect of S-nitrosothiols against clinical isolates from keratitis

    Directory of Open Access Journals (Sweden)

    de Oliveira MG

    2012-11-01

    Full Text Available Angelino Julio Cariello,1 Paulo José Martins Bispo,2 Gabriela Freitas Pereira de Souza,3 Antonio Carlos Campos Pignatari,2 Marcelo Ganzarolli de Oliveira,3 Ana Luisa Hofling-Lima11Department of Ophthalmology, 2Division of Infectious Diseases, Federal University of São Paulo, 3Institute of Chemistry, University of Campinas, Campinas, São Paulo, BrazilBackground: The purpose of this study was to evaluate the antimicrobial activity of two nitric oxide donors, ie, S-nitrosoglutathione (GSNO and S-nitroso-N-acetylcysteine (SNAC, against clinical isolates from patients with infectious keratitis.Methods: Reference broth microdilution assays were performed to determine the minimum inhibitory and bactericidal concentrations for GSNO and SNAC against four American Type Culture Collection strains and 52 clinical isolates from patients with infectious keratitis as follows: 14 (26.9% Pseudomonas species; 13 (25.0% coagulase-negative Staphylococci; 10 (19.2% Staphylococcus aureus; nine (17.3% Serratia marcescens; and six (11.5% Enterobacter aerogenes. Sterility control and bacterial growth control were also performed.Results: SNAC showed lower minimum inhibitory and bactericidal concentrations than GSNO for all clinical isolates from patients with infectious keratitis. For Gram-positive bacteria, mean minimum inhibitory and bactericidal concentrations were 2.1 ± 1.3 and 8.6 ± 3.8 mM for SNAC and 4.6 ± 3.2 and 21.5 ± 12.5 mM for GSNO (P < 0.01. For Gram-negative bacteria, mean minimum inhibitory and bactericidal concentrations were 3.3 ± 1.4 and 6.1 ± 3.4 mM for SNAC and 12.4 ± 5.4 and 26.5 ± 10.1 mM for GSNO (P < 0.01. The minimum bactericidal to inhibitory concentration ratio was ≤8 in 100% of all isolates tested for SNAC and in 94.2% tested for GSNO.Conclusions: SNAC and GSNO had effective inhibitory and bactericidal effects against bacterial isolates from keratitis. SNAC showed greater antimicrobial activity than GSNO against all bacteria

  8. A complex of equine lysozyme and oleic acid with bactericidal activity against Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Emily A Clementi

    Full Text Available HAMLET and ELOA are complexes consisting of oleic acid and two homologous, yet functionally different, proteins with cytotoxic activities against mammalian cells, with HAMLET showing higher tumor cells specificity, possibly due to the difference in propensity for oleic acid binding, as HAMLET binds 5-8 oleic acid molecules per protein molecule and ELOA binds 11-48 oleic acids. HAMLET has been shown to possess bactericidal activity against a number of bacterial species, particularly those with a respiratory tropism, with Streptococcus pneumoniae displaying the greatest degree of sensitivity. We show here that ELOA also displays bactericidal activity against pneumococci, which at lower concentrations shows mechanistic similarities to HAMLET's bactericidal activity. ELOA binds to S. pneumoniae and causes perturbations of the plasma membrane, including depolarization and subsequent rupture, and activates an influx of calcium into the cells. Selective inhibition of calcium channels and sodium/calcium exchange activity significantly diminished ELOA's bactericidal activity, similar to what we have observed with HAMLET. Finally, ELOA-induced death was also accompanied by DNA fragmentation into high molecular weight fragments - an apoptosis-like morphological phenotype that is seen during HAMLET-induced death. Thus, in contrast to different mechanisms of eukaryote cell death induced by ELOA and HAMLET, these complexes are characterized by rather similar activities towards bacteria. Although the majority of these events could be mimicked using oleic acid alone, the concentrations of oleic acid required were significantly higher than those present in the ELOA complex, and for some assays, the results were not identical between oleic acid alone and the ELOA complex. This indicates that the lipid, as a common denominator in both complexes, is an important component for the complexes' bactericidal activities, while the proteins are required both to solubilize

  9. A complex of equine lysozyme and oleic acid with bactericidal activity against Streptococcus pneumoniae.

    Science.gov (United States)

    Clementi, Emily A; Wilhelm, Kristina R; Schleucher, Jürgen; Morozova-Roche, Ludmilla A; Hakansson, Anders P

    2013-01-01

    HAMLET and ELOA are complexes consisting of oleic acid and two homologous, yet functionally different, proteins with cytotoxic activities against mammalian cells, with HAMLET showing higher tumor cells specificity, possibly due to the difference in propensity for oleic acid binding, as HAMLET binds 5-8 oleic acid molecules per protein molecule and ELOA binds 11-48 oleic acids. HAMLET has been shown to possess bactericidal activity against a number of bacterial species, particularly those with a respiratory tropism, with Streptococcus pneumoniae displaying the greatest degree of sensitivity. We show here that ELOA also displays bactericidal activity against pneumococci, which at lower concentrations shows mechanistic similarities to HAMLET's bactericidal activity. ELOA binds to S. pneumoniae and causes perturbations of the plasma membrane, including depolarization and subsequent rupture, and activates an influx of calcium into the cells. Selective inhibition of calcium channels and sodium/calcium exchange activity significantly diminished ELOA's bactericidal activity, similar to what we have observed with HAMLET. Finally, ELOA-induced death was also accompanied by DNA fragmentation into high molecular weight fragments - an apoptosis-like morphological phenotype that is seen during HAMLET-induced death. Thus, in contrast to different mechanisms of eukaryote cell death induced by ELOA and HAMLET, these complexes are characterized by rather similar activities towards bacteria. Although the majority of these events could be mimicked using oleic acid alone, the concentrations of oleic acid required were significantly higher than those present in the ELOA complex, and for some assays, the results were not identical between oleic acid alone and the ELOA complex. This indicates that the lipid, as a common denominator in both complexes, is an important component for the complexes' bactericidal activities, while the proteins are required both to solubilize and/or present the

  10. Ambroxol inhibits mucoid conversion of Pseudomonas aeruginosa and contributes to the bactericidal activity of ciprofloxacin against mucoid P. aeruginosa biofilms.

    Science.gov (United States)

    Wang, Wenlei; Yu, Jialin; He, Yu; Wang, Zhengli; Li, Fang

    2016-07-01

    Pseudomonas aeruginosa is an opportunistic human pathogen that can cause severe infections in immunocompromised individuals. Because it forms biofilms, which protect against host immune attack and increase resistance to conventional antibiotics, mucoid P. aeruginosa is nearly impossible to eradicate. Moreover, mucoid conversion of P. aeruginosa in cystic fibrosis (CF) patients leads to poor outcomes. This conversion is mainly due to mucA gene mutation, which is thought to be induced by polymorphonuclear leukocytes (PMNs) and the reactive oxygen species they release. Ambroxol, a mucolytic agent with antioxidant characteristics, is used clinically, and this compound has recently been demonstrated to possess anti-biofilm properties. In this study, we found that ambroxol inhibits the H2 O2 -mediated conversion of P. aeruginosa from a non-mucoid to a mucoid phenotype, an effect that is due to its antioxidant property against H2 O2 . Furthermore, the bactericidal activity of ciprofloxacin against mucoid P. aeruginosa biofilms was increased in vitro when used in combination with ambroxol.

  11. Acute effects of triclosan, diclofenac and carbamazepine on feeding performance of Japanese medaka fish (Oryzias latipes).

    Science.gov (United States)

    Nassef, Mohamed; Matsumoto, Shuhei; Seki, Masanori; Khalil, Fatma; Kang, Ik Joon; Shimasaki, Yohei; Oshima, Yuji; Honjo, Tsuneo

    2010-08-01

    The toxicity of three pharmaceutical and personal care products (PPCPs)--carbamazepine (CBMZ), diclofenac (DCF), and triclosan (TCS)--was examined by measuring their effects on feeding behavior and swimming speed of adult Japanese medaka fish (Oryzias latipes). Medaka were exposed to 6.15 mg L(-1) CBMZ, 1.0 mg L(-1) DCF, 0.17 mg L(-1) TCS, or no PPCP (control) for 9 d. Fish behaviors were monitored during days 5-9 of the exposure period. Feeding behavior (time to eat midge larvae, TE) and swimming speed (SS) of individual exposed and control fish were tracked in two dimensions, using an automated system with a digital charge-coupled device camera. As a result, feeding behavior was affected by exposure to CBMZ and DCF, while SS was altered by exposure to CBMZ and TCS. Thus, TCS, DCF and CBMZ appear to affect fish behaviors through different mechanisms. Overall, the results suggest that behavioral changes may provide a sensitive indicator for assessing the toxicity of PPCPs to aquatic organisms. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  12. Characterization of triclosan metabolism in Sphingomonas sp. strain YL-JM2C

    Science.gov (United States)

    Mulla, Sikandar I.; Wang, Han; Sun, Qian; Hu, Anyi; Yu, Chang-Ping

    2016-02-01

    Triclosan (TCS) is one of the most widespread emerging contaminants and has adverse impact on aquatic ecosystem, yet little is known about its complete biodegradation mechanism in bacteria. Sphingomonas sp, strain YL-JM2C, isolated from activated sludge of a wastewater treatment plant, was very effective on degrading TCS. Response surface methodology (RSM) was applied to optimize the conditions like temperature and pH. From RSM, the optimal TCS degradation conditions were found to be 30 °C and pH 7.0. Under optimal conditions, strain YL-JM2C completely mineralized TCS (5 mg L-1) within 72 h. Gas chromatography-mass spectrometry analysis revealed that 2,4-dichlorophenol, 2-chlorohydroquinone and hydroquinone are three main by-products of TCS. Furthermore, stable isotope experimental results revealed that the 13C12-TCS was completely mineralized into CO2 and part of heavier carbon (13C) of labeled TCS was utilized by strain YL-JM2C to synthesize fatty acids (PLFAs). Cell surface hydrophobicity (CSH) and degradation test results suggested that the strain could enhance degradation capacity of TCS through increasing CSH. In addition, the bacterium also completely degraded spiked TCS (5 mg L-1) in wastewater collected from the wastewater treatment plant. Hence, these results suggest that the strain has potential to remediate TCS in the environment.

  13. Sorption of triclosan on electrospun fibrous membranes: Effects of pH and dissolved organic matter

    Directory of Open Access Journals (Sweden)

    Jiangjie Xu

    2015-11-01

    Full Text Available Three hydrophobic and polyporous electrospun fibrous membranes (EFMs were prepared by electrospinning methoxy polyethylene glycol-poly(lactide-co-glycolide (MPEG-PLGA, poly(d,l-lactide-co-glycolide (PLGA and poly(d,l-lactide (PDLLA. The effects of pH and dissolved organic matter (DOM on triclosan (TCS sorption by EFMs in aqueous solution were investigated. The results indicated that hydrogen bonding, hydrophobic and π–π bonding interactions led to fast adsorption, which governed the adsorption rates of TCS onto EFMs. The maximum sorption capacities of MPEG-PLGA, PLGA and PDLLA reached 130, 93 and 99 mg g−1, respectively, which were in positive correlation with their pore volumes and influenced by pore filling processes. The solution pH could significantly influence the TCS sorption by EFMs. In acid condition, protonated TCS facilitated their sorption onto EFMs. No obvious sorption was observed in alkaline condition due to repulsive forces between negatively charged EFMs and deprotonated TCS (pKa = 7.9. The presence of DOM inhibited TCS sorption onto EFMs due to competitive adsorption. The results could be due to the occupation of the adsorption sites and the blockage of the pore entrance by DOM.

  14. Degradation of triclosan in the presence of p-aminobenzoic acid under simulated sunlight irradiation.

    Science.gov (United States)

    Zhai, Pingping; Chen, Xuan; Dong, Wenbo; Li, Hongjing; Chovelon, Jean-Marc

    2017-01-01

    This study aimed to investigate the degradation of triclosan (TCS) in the presence of p-aminobenzoic acid (PABA) under simulated sunlight irradiation (λ ≥ 290 nm). The effect of PABA concentration, pH, dissolved organic matter (DOM), and DOM-hydrolytic Fe(III) species complexes on the photodegradation of TCS in the presence of PABA (TCS-PABA) was also studied. The photolysis of TCS-PABA obeyed pseudo-first-order kinetics well, and the degradation of TCS-PABA enhanced with increasing solution pH (from 3.0 to 11.0). The presence of PABA inhibited the degradation of TCS-PABA, and the weakest inhibitory effect was observed while the concentration of PABA was 5 mg L(-1). The addition of DOM (Suwannee River fulvic acid standard I [SRFA], Suwannee River HA standard II [SRHA], and Suwannee River natural organic matter [SRNOM]) showed different inhibition effects on TCS-PABA degradation. However, higher Fe(III) concentration at the DOM concentration of 5 mg L(-1) could favor the formation of DOM-hydrolytic Fe(III) species complexes, further accelerating the degradation of TCS-PABA. In comparison with deionized water (DI water), TCS-PABA could be better photodegraded in river water nearby the effluent of a wastewater treatment plant. This study provides useful information for understanding the natural behavior of TCS in the presence of other organic contaminants.

  15. Uptake and accumulation of antimicrobials, triclocarban and triclosan, by food crops in a hydroponic system.

    Science.gov (United States)

    Mathews, Shiny; Henderson, Shannon; Reinhold, Dawn

    2014-05-01

    Commonly used in personal care products, triclocarban (TCC) and triclosan (TCS) are two chemicals with antimicrobial properties that have recently been recognized as environmental contaminants with the potential to adversely affect human health. The objective of the study described herein was to evaluate the potential of food crops to uptake TCC and TCS. Eleven food crops, grown in hydroponic nutrient media, were exposed to a mixture of 500 μg L(-1) TCC and TCS. After 4 weeks of exposure, roots accumulated 86-1,350 mg kg(-1) of antimicrobials and shoots had accumulated 0.33-5.35 mg kg(-1) of antimicrobials. Translocation from roots to shoots was less than 1.9 % for TCC and 3.7 % for TCS, with the greatest translocation for TCC observed for pepper, celery, and asparagus and for TCS observed for cabbage, broccoli, and asparagus. For edible tuber- or bulb-producing crops, the concentrations of both TCC and TCS were lower in the tubers than in the roots. Exposure calculations using national consumption data indicated that the average exposure to TCC and TCS from eating contaminated crops was substantially less than the exposure expected to cause adverse effects, but exceeded the predicted exposure from drinking water. Exposure to antimicrobials through food crops would be substantially reduced through limiting consumption of beets and onions.

  16. Photochemical reaction between triclosan and nitrous acid in the atmospheric aqueous environment

    Science.gov (United States)

    Ma, Jianzhong; Zhu, Chengzhu; Lu, Jun; Lei, Yu; Wang, Jizhong; Chen, Tianhu

    2017-05-01

    Nitrous acid (HONO) is an important tropospheric pollutant and a major source of hydroxyl radical in the atmospheric gas phase. However, studies on the role of HONO in atmospheric aqueous phase chemistry processes are relatively few. The present work investigated the photochemical reaction of HONO with triclosan (TCS), which is an emerging contaminant, using a combination of laser flash photolysis spectrometry and gas chromatography mass spectrometry. With these techniques, the reaction pathway of HONO with TCS was proposed by directly monitoring the transient species and detecting the stable products. ·OH was generated from the photodissociation of the HONO aqueous solution and attacked TCS molecules on different sites to produce the TCS-OH adducts with a second-order rate constant of 1.11 × 109 L mol-1 s-1. The ·OH added a C atom adjacent to the ether bond in the aromatic ring of TCS and self-decayed when the ether bond broke. The intermediates generated from the addition of ·OH to the benzene ring of the TCS molecular structure were immediately nitrated by HONO, which played a key role in the formation process of nitrocompounds. An atmospheric model suggests that the aqueous oxidation of TCS by ·OH is a major reaction at high liquid water concentrations, and the photolysis of TCS dominates under low-humidity conditions.

  17. The commonly used antimicrobial additive triclosan is a liver tumor promoter.

    Science.gov (United States)

    Yueh, Mei-Fei; Taniguchi, Koji; Chen, Shujuan; Evans, Ronald M; Hammock, Bruce D; Karin, Michael; Tukey, Robert H

    2014-12-02

    Triclosan [5-chloro-2-(2,4-dichlorophenoxy)phenol; TCS] is a synthetic, broad-spectrum antibacterial chemical used in a wide range of consumer products including soaps, cosmetics, therapeutics, and plastics. The general population is exposed to TCS because of its prevalence in a variety of daily care products as well as through waterborne contamination. TCS is linked to a multitude of health and environmental effects, ranging from endocrine disruption and impaired muscle contraction to effects on aquatic ecosystems. We discovered that TCS was capable of stimulating liver cell proliferation and fibrotic responses, accompanied by signs of oxidative stress. Through a reporter screening assay with an array of nuclear xenobiotic receptors (XenoRs), we found that TCS activates the nuclear receptor constitutive androstane receptor (CAR) and, contrary to previous reports, has no significant effect on mouse peroxisome proliferation activating receptor α (PPARα). Using the procarcinogen diethylnitrosamine (DEN) to initiate tumorigenesis in mice, we discovered that TCS substantially accelerates hepatocellular carcinoma (HCC) development, acting as a liver tumor promoter. TCS-treated mice exhibited a large increase in tumor multiplicity, size, and incidence compared with control mice. TCS-mediated liver regeneration and fibrosis preceded HCC development and may constitute the primary tumor-promoting mechanism through which TCS acts. These findings strongly suggest there are adverse health effects in mice with long-term TCS exposure, especially on enhancing liver fibrogenesis and tumorigenesis, and the relevance of TCS liver toxicity to humans should be evaluated.

  18. Association of triclosan to casein proteins through solvent-mediated high-pressure homogenization.

    Science.gov (United States)

    Roach, A; Dunlap, J; Harte, F

    2009-03-01

    The association of triclosan (TCS), a widely used hydrophobic compound, to the bovine casein micelle is investigated in this study. The use of high-pressure homogenization (HPH) at 0, 100, 200, and 300 MPa was introduced as a method for the dissociation of casein micelles in a skim milk/ethanol solution (1: 1, v/v) in the presence of TCS at 20, 80, and 160 mg/L where ethanol evaporation served as the final step for TCS association to caseins. The majority of TCS (over 80%) was associated with the caseins regardless of initial TCS concentration or applied pressure. TCS association to caseins was enhanced by 30% with continued pressurization to 300 MPa. Micellar dissociation and reassociation was found to be an irreversible process as evidenced by microscopy images. Pressurization to 300 MPa resulted in the formation of an integrated protein network of casein proteins and noncovalently linked whey proteins where the solubility of TCS was enhanced up to 40 times its reported water solubility at the highest initial TCS level of 160 mg/L. Reformed micelles exhibited Newtonian flow behavior at all pressure levels. This study provides evidence for the solubility enhancing quality of TCS through the solvent-mediated pressure/shear-induced dissociation of casein proteins.

  19. Triclosan and anuran metamorphosis: no effect on thyroid-mediated metamorphosis in Xenopus laevis.

    Science.gov (United States)

    Fort, Douglas J; Rogers, Robert L; Gorsuch, Joseph W; Navarro, Lisa T; Peter, Robert; Plautz, James R

    2010-02-01

    Nieuwkoop and Faber stage 51 Xenopus laevis larvae were exposed for 21 days to four different concentrations of triclosan (TCS): <0.2 (control), 0.6, 1.5, 7.2, or 32.3 microg TCS/l. Primary endpoints were survival, hind limb length, body length (whole; snout to vent), developmental stage, wet whole body weight, and thyroid histology. Thyroid hormone (TH) concentrations were determined in whole thyroid and plasma samples from stage-matched exposure day 21 specimens. TH receptor-beta (TRbeta) expression was measured in stage-matched tail fin tissue samples collected at exposure days 0 and 21. Reduced larval growth occurred at exposure day 21 with 1.5 microg/l treatment. Larval developmental stage at exposure day 21 was not significantly different from controls based on observed parameters. Thyroid histology was not affected by TCS, and thyroxine (T4) levels in thyroid glands or plasma were not different from controls. A concentration-dependent increase in TRbeta expression in exposure day 21 larvae was not detected. However, increased expression was found in stage-matched larvae exposed to 1.5 or 7.2 microg TCS/l. Our study indicates that environmentally relevant TCS concentrations do not alter the normal course of thyroid-mediated metamorphosis in this standard anuran model.

  20. Biodegradable polyesters reinforced with triclosan loaded polylactide micro/nanofibers: Properties, release and biocompatibility

    Directory of Open Access Journals (Sweden)

    L. J. del Valle

    2012-04-01

    Full Text Available Mechanical properties and drug release behavior were studied for three biodegradable polyester matrices (polycaprolactone, poly(nonamethylene azelate and the copolymer derived from 1,9-nonanediol and an equimolar mixture of azelaic and pimelic acids reinforced with polylactide (PLA fibers. Electrospinning was used to produce suitable mats constituted by fibers of different diameters (i.e. from micro- to nanoscale and a homogeneous dispersion of a representative hydrophobic drug (i.e. triclosan. Fabrics were prepared by a molding process, which allowed cold crystallization of PLA micro/nanofibers and hot crystallization of the polyester matrices. The orientation of PLA molecules during electrospinning favored the crystallization process, which was slightly enhanced when the diameter decreased. Incorporation of PLA micro/nanofibers led to a significant increase in the elastic modulus and tensile strength, and in general to a decrease in the strain at break. The brittle fracture was clearer when high molecular weight samples with high plastic deformation were employed. Large differences in the release behavior were detected depending on the loading process, fiber diameter size and hydrophobicity of the polyester matrix. The release of samples with the drug only loaded into the reinforcing fibers was initially fast and then became slow and sustained, resulting in longer lasting antimicrobial activity. Biocompatibility of all samples studied was demonstrated by adhesion and proliferation assays using HEp-2 cell cultures.

  1. Degradation of triclosan in aqueous solution by dielectric barrier discharge plasma combined with activated carbon fibers.

    Science.gov (United States)

    Xin, Lu; Sun, Yabing; Feng, Jingwei; Wang, Jian; He, Dong

    2016-02-01

    The degradation of triclosan (TCS) in aqueous solution by dielectric barrier discharge (DBD) plasma with activated carbon fibers (ACFs) was investigated. In this study, ACFs and DBD plasma coexisted in a planar DBD plasma reactor, which could synchronously achieve degradation of TCS, modification and in situ regeneration of ACFs, enhancing the effect of recycling of ACFs. The properties of ACFs before and after modification by DBD plasma were characterized by BET and XPS. Various processing parameters affecting the synergetic degradation of TCS were also investigated. The results exhibited excellent synergetic effects in DBD plasma-ACFs system on TCS degradation. The degradation efficiency of 120 mL TCS with initial concentration of 10 mg L(-1) could reach 93% with 1 mm thick ACFs in 18 min at input power of 80 W, compared with 85% by single DBD plasma. Meanwhile, the removal rate of total organic carbon increased from 12% at pH 6.26-24% at pH 3.50. ACFs could ameliorate the degradation efficiency for planar DBD plasma when treating TCS solution at high flow rates or at low initial concentrations. A possible degradation pathway of TCS was investigated according to the detected intermediates, which were identified by liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) combined with theoretical calculation of Gaussian 09 program.

  2. Serum bactericidal activity in a secondary school population following an outbreak of meningococcal disease: effects of carriage and secretor status.

    Science.gov (United States)

    Zorgani, A A; James, V S; Stewart, J; Blackwell, C C; Elton, R A; Weir, D M

    1996-06-01

    Sera obtained from 106 children following an outbreak of Neisseria meningitidis (B:4:P1.15) were screened for bactericidal antibodies against isolates of meningococci and Neisseria lactamica. Most had high titres of antibodies to N. lactamica and N. meningitidis NG:4:- but not to capsulate isolates: B:4:P1.15; B:15:P1.16; B:4:-; C:4:-. Bactericidal activity was higher for both carriers and secretors but the differences were not significant. Bactericidal activity was not associated with total or specific IgA or IgM. Carriers had significantly higher levels of IgG to N. lactamica but not to NG:4:- in sera with bactericidal activity for each of the capsulate strains. Among non-carriers, higher levels of IgG to N. lactamica were associated with killing of B:4:P1.15 and B:4:-. Secretors' sera with bactericidal activity had significantly higher levels of IgG to N. lactamica compared with sera that were not bactericidal. This was not observed among non-secretors. Antibodies to the outbreak strain were adsorbed by all Neisseria isolates tested and absorption of sera with N. lactamica alone completely removed the bactericidal activity against the outbreak strain.

  3. Spectrally selective UV bactericidal effect for curative treatment of post-surgical intra-abdominal abscesses and other infections

    Science.gov (United States)

    Dudelzak, Alexander E.; Miller, Mark A.; Babichenko, Sergey M.

    2004-07-01

    Results of in-vitro studies of bactericidal effects of ultraviolet (UV) irradiation on strains causing drug-resistant endo-cavital infections (Enterococcus, Staphylococcus aureus, Pseudomonas aeruginosa, and others) are presented. An original technique to measure effects of UV-irradiation on bacterial growth at different wavelengths has been developed. Spectral dependences of the bactericidal effect have been observed, and spectral maxima of bactericidal efficiency have been found. Applications to curative treatments of wounds, post-surgical intra-abdominal abscesses and other diseases are discussed.

  4. Sporicidal/bactericidal textiles via the chlorination of silk.

    Science.gov (United States)

    Dickerson, Matthew B; Lyon, Wanda; Gruner, William E; Mirau, Peter A; Slocik, Joseph M; Naik, Rajesh R

    2012-03-01

    Bacterial spores, such as those of the Bacillus genus, are extremely resilient, being able to germinate into metabolically active cells after withstanding harsh environmental conditions or aggressive chemical treatments. The toughness of the bacterial spore in combination with the use of spores, such as those of Bacillus anthracis, as a biological warfare agent necessitates the development of new antimicrobial textiles. In this work, a route to the production of fabrics that kill bacterial spores and cells within minutes of exposure is described. Utilizing this facile process, unmodified silk cloth is reacted with a diluted bleach solution, rinsed with water, and dried. The chlorination of silk was explored under basic (pH 11) and slightly acidic (pH 5) conditions. Chloramine-silk textiles prepared in acidified bleach solutions were found to have superior breaking strength and higher oxidative Cl contents than those prepared under caustic conditions. Silk cloth chlorinated for ≥1 h at pH 5 was determined to induce >99.99996% reduction in the colony forming units of Escherichia coli, as well as Bacillus thuringiensis Al Hakam (B. anthracis simulant) spores and cells within 10 min of contact. The processing conditions presented for silk fabric in this study are highly expeditionary, allowing for the on-site production of protein-based antimicrobial materials from a variety of agriculturally produced feed-stocks. © 2012 American Chemical Society

  5. Bactericidal Efficiency of Silver Nanoparticles Synthesized from Annona squamosa

    Science.gov (United States)

    Jayavardhanan, R.; Nanda, Anima

    2016-09-01

    Nanotechnology is described as an emerging technology that not only holds promise for society, but also is capable of providing novel approaches to overcome our common problems. The present study focused on the synthesis of silver nanoparticles using the metabolites of Annona squamosa seeds. The biological reduction procedure proposed in this method was considered as better one compared to chemical mediated reduction methods. The advantages include nontoxic to the environment, less energy consuming and highly suitable for further biological applications. The seeds were separated from the fruit pulp, grinded into powder and dissolved in distilled water. The suspension was used as reducing agent and treated with silver nitrate at the concentration of 1mM. The reduction reaction was continuously monitored by UV-visible photo spectrometer. Further the samples were subjected to AFM, SEM and XRD analysis for the confirmation of their size, structure, agglomerations and the arrangements of crystals. Finally the antibacterial properties of nanoparticles were tested against clinically important pathogenic microorganisms using disc diffusion method and compared with the activities of standard antibiotics. The combinational effects of nanoparticles with commercial antibiotics also were tested by the same method.

  6. Quantification of Hydroxylated Polybrominated Diphenyl Ethers (OH-BDEs, Triclosan, and Related Compounds in Freshwater and Coastal Systems.

    Directory of Open Access Journals (Sweden)

    Jill F Kerrigan

    Full Text Available Hydroxylated polybrominated diphenyl ethers (OH-BDEs are a new class of contaminants of emerging concern, but the relative roles of natural and anthropogenic sources remain uncertain. Polybrominated diphenyl ethers (PBDEs are used as brominated flame retardants, and they are a potential source of OH-BDEs via oxidative transformations. OH-BDEs are also natural products in marine systems. In this study, OH-BDEs were measured in water and sediment of freshwater and coastal systems along with the anthropogenic wastewater-marker compound triclosan and its photoproduct dioxin, 2,8-dichlorodibenzo-p-dioxin. The 6-OH-BDE 47 congener and its brominated dioxin (1,3,7-tribromodibenzo-p-dioxin photoproduct were the only OH-BDE and brominated dioxin detected in surface sediments from San Francisco Bay, the anthropogenically impacted coastal site, where levels increased along a north-south gradient. Triclosan, 6-OH-BDE 47, 6-OH-BDE 90, 6-OH-BDE 99, and (only once 6'-OH-BDE 100 were detected in two sediment cores from San Francisco Bay. The occurrence of 6-OH-BDE 47 and 1,3,7-tribromodibenzo-p-dioxin sediments in Point Reyes National Seashore, a marine system with limited anthropogenic impact, was generally lower than in San Francisco Bay surface sediments. OH-BDEs were not detected in freshwater lakes. The spatial and temporal trends of triclosan, 2,8-dichlorodibenzo-p-dioxin, OH-BDEs, and brominated dioxins observed in this study suggest that the dominant source of OH-BDEs in these systems is likely natural production, but their occurrence may be enhanced in San Francisco Bay by anthropogenic activities.

  7. Cytogenetic analysis of oral mucosa cells, induced by chlorhexidine, essential oils in ethanolic solution and triclosan mouthwashes

    Energy Technology Data Exchange (ETDEWEB)

    Ros-Llor, Irene; Lopez-Jornet, Pia, E-mail: majornet@um.es

    2014-07-15

    Objectives: The aim of this study was to evaluate DNA damage and cytokinetic defects, proliferative potential and cell death caused by the frequent use of mouthrinses containing chlorhexidine, triclosan and essential oils in ethanolic solution, compared to a placebo mouthwash. Study design: This double-blind, prospective, randomized clinical trial included 80 Caucasian patients. Subjects were divided into four groups: Group I used a mouthrinse, Triclosan; Group II used physiological saline; Group III used chlorhexidine; Group IV a mouthrinse with essential oils in ethanolic solution. All subjects used the mouthrinses for two weeks (15 ml, twice a day, rinsing for 30 s). Two cell samples per subject were collected, before and after mouthrinse use (on day 0 and day 15). Samples were processed as follows: cell collection from cheeks with a cytobrush; cell centrifuge; slide preparation, fixation and staining; and fluorescent microscope analysis. 2000 exfoliated cells were screened for nuclear abnormalities, particularly the presence of micronuclei by means of cytome assay. Results: No significant differences between study times (before and after use of mouthwash) were identified for any of the variables studied (p>0.05). Differences between mouthrinse groups were also compared but no significant differences were found (p>0.05). Conclusions: This study did not observe any genotoxic effect resulting from mouthrinse use. - Highlights: • Mouthrinses are used widely, mainly for their capacity to control dental plaque. • No genotoxic effects from the mouthrinses triclosan, chlorhexidine essential oils solution. • The buccal cytome assay is a sensitive, non-invasive, and low cost technique.

  8. Adsorption of triclosan on carbon nanotubes%三氯生在碳纳米管上的吸附

    Institute of Scientific and Technical Information of China (English)

    胡翔; 赵娜; 魏杰

    2009-01-01

    Pharmaceutical and personal care products(PPCPs)have gained widespread public attention as a new environmental problem.Carbon nanotubes were used to adsorb triclosan from aqueous solution.The influences of diameter and dosage of carbon nanotubes,temperature,pH value and oscillation time on triclosan removal rate were evaluated in this paper.Experimental results indicated that the adsorb velocity of tficlosan on carbon nanotubes is very fast,and the removal rate is increased with the decrease of carbon nanotubes diameter.Low temperature is helpful for adsorption process.The removal rate of triclosan can reach 97% when the pH value is in the range of 6.5 to 7.The adsorption process can be well described by the Langmuir and Freundlich equilibrium models.%药品和个人护理用品(PPCPs)已成为一个引起广泛关注的新的环境问题.采用碳纳米管(CNTs)对水溶液中的三氯生进行吸附处理,考察了碳纳米管粒径及用量、温度、pH、振荡时间等因素对三氯生去除率的影响.研究结果表明,碳纳米管能快速吸附水中的三氯生,粒径较小的碳纳米管町获得较高的三氯生去除率;低温有利于吸附反应的进行;pH在6.5~7.0时,三氯生的去除率可达97%.三氯生在碳纳米管上的吸附可以很好地用Langmuir和Freundlieh吸附等温方程进行描述.

  9. Quantification of Hydroxylated Polybrominated Diphenyl Ethers (OH-BDEs), Triclosan, and Related Compounds in Freshwater and Coastal Systems

    Science.gov (United States)

    Kerrigan, Jill F.; Engstrom, Daniel R.; Yee, Donald; Sueper, Charles; Erickson, Paul R.; Grandbois, Matthew; McNeill, Kristopher; Arnold, William A.

    2015-01-01

    Hydroxylated polybrominated diphenyl ethers (OH-BDEs) are a new class of contaminants of emerging concern, but the relative roles of natural and anthropogenic sources remain uncertain. Polybrominated diphenyl ethers (PBDEs) are used as brominated flame retardants, and they are a potential source of OH-BDEs via oxidative transformations. OH-BDEs are also natural products in marine systems. In this study, OH-BDEs were measured in water and sediment of freshwater and coastal systems along with the anthropogenic wastewater-marker compound triclosan and its photoproduct dioxin, 2,8-dichlorodibenzo-p-dioxin. The 6-OH-BDE 47 congener and its brominated dioxin (1,3,7-tribromodibenzo-p-dioxin) photoproduct were the only OH-BDE and brominated dioxin detected in surface sediments from San Francisco Bay, the anthropogenically impacted coastal site, where levels increased along a north-south gradient. Triclosan, 6-OH-BDE 47, 6-OH-BDE 90, 6-OH-BDE 99, and (only once) 6’-OH-BDE 100 were detected in two sediment cores from San Francisco Bay. The occurrence of 6-OH-BDE 47 and 1,3,7-tribromodibenzo-p-dioxin sediments in Point Reyes National Seashore, a marine system with limited anthropogenic impact, was generally lower than in San Francisco Bay surface sediments. OH-BDEs were not detected in freshwater lakes. The spatial and temporal trends of triclosan, 2,8-dichlorodibenzo-p-dioxin, OH-BDEs, and brominated dioxins observed in this study suggest that the dominant source of OH-BDEs in these systems is likely natural production, but their occurrence may be enhanced in San Francisco Bay by anthropogenic activities. PMID:26466159

  10. Integrated antifouling and bactericidal polymer membranes through bioinspired polydopamine/poly(N-vinyl pyrrolidone) coating

    Science.gov (United States)

    Wang, Xianghong; Yuan, Shuaishuai; Shi, Dean; Yang, Yingkui; Jiang, Tao; Yan, Shunjie; Shi, Hengchong; Luan, Shifang; Yin, Jinghua

    2016-07-01

    Polypropylene (PP) non-woven has been widely used as wound dressing; however, the hydrophobic nature of PP can initiate bacterial attachment and subsequent biofilm formation. Herein, we propose a facile approach to functionalize PP non-woven with poly(ethylene glycol) (PEG) and poly(N-vinyl pyrrolidone)-iodine complex (PVP-I). PVP and PEG were successively tethered onto PP non-woven surface via versatile bioinspired dopamine (DA) chemistry, followed by complexing iodine with PVP moieties. It was demonstrated through the field emission scanning electron microscope (SEM) and spread plate method that the as-modified PP non-woven integrated both antifouling property of PEG for suppressing bacterial adhesion, and bactericidal property of PVP-I for killing the few adherent bacteria. Meanwhile, it could greatly resist platelet and red blood cell adhesion. The integrated antifouling and bactericidal PP non-woven surfaces might have great potential in various wound dressing applications.

  11. Reinforcement of the bactericidal effect of ciprofloxacin on Pseudomonas aeruginosa biofilm by hyperbaric oxygen treatment

    DEFF Research Database (Denmark)

    Kolpen, Mette; Mousavi, Nabi; Sams, Thomas

    2016-01-01

    mechanisms affecting antibiotic effectiveness on biofilms remain unclear, accumulating evidence suggests that the efficacy of several bactericidal antibiotics such as ciprofloxacin is enhanced by stimulation of the aerobic respiration of pathogens, and that lack of O2 increases their tolerance. Reoxygenation...... of O2-depleted biofilms may thus improve susceptibility to ciprofloxacin possibly by restoring aerobic respiration. We tested such a strategy using reoxygenation of O2-depleted P. aeruginosa strain PAO1 agarose-embedded biofilms by hyperbaric oxygen treatment (HBOT) (100% O2, 2.8bar), enhancing...... the diffusive supply for aerobic respiration during ciprofloxacin treatment. This proof-of-principle study demonstrates that biofilm reoxygenation by HBOT can significantly enhance the bactericidal activity of ciprofloxacin on P. aeruginosa. Combining ciprofloxacin treatment with HBOT thus clearly has potential...

  12. Bactericidal Activity of Oleo-gum Resins Doped with Metal Oxides

    Directory of Open Access Journals (Sweden)

    MSc Diogo José Horst

    2016-12-01

    Full Text Available This work aimed to evaluate the bactericidal activity of vegetable oil-gum resins (Styrax benzoin, Commiphora mirrha, and Boswellia papyrifera doped with metal oxides (TiO2, P25, MoO3 e Cu2O in nanometric dimension. The in vitro susceptibility of pathogenic Gram-negative bacteria E. coli was accessed. The antibiogram essay was performed using the semi-quantitative method Kirby-Bauer (KB agar diffusion test. The materials obtained were characterized by ultraviolet visible (UV-Vis spectrophotometry, additionally; its morphology was characterized by scanning electron microscopy (SEM. The results show that in most cases the materials present bactericidal activity, thereby inhibiting both planktonic and surface associated growth of this microorganism.

  13. Bactericidal Antibiotics Induce Toxic Metabolic Perturbations that Lead to Cellular Damage.

    Science.gov (United States)

    Belenky, Peter; Ye, Jonathan D; Porter, Caroline B M; Cohen, Nadia R; Lobritz, Michael A; Ferrante, Thomas; Jain, Saloni; Korry, Benjamin J; Schwarz, Eric G; Walker, Graham C; Collins, James J

    2015-11-03

    Understanding how antibiotics impact bacterial metabolism may provide insight into their mechanisms of action and could lead to enhanced therapeutic methodologies. Here, we profiled the metabolome of Escherichia coli after treatment with three different classes of bactericidal antibiotics (?-lactams, aminoglycosides, quinolones). These treatments induced a similar set of metabolic changes after 30 min that then diverged into more distinct profiles at later time points. The most striking changes corresponded to elevated concentrations of central carbon metabolites, active breakdown of the nucleotide pool, reduced lipid levels, and evidence of an elevated redox state. We examined potential end-target consequences of these metabolic perturbations and found that antibiotic-treated cells exhibited cytotoxic changes indicative of oxidative stress, including higher levels of protein carbonylation, malondialdehyde adducts, nucleotide oxidation, and double-strand DNA breaks. This work shows that bactericidal antibiotics induce a complex set of metabolic changes that are correlated with the buildup of toxic metabolic by-products.

  14. Cefodizime (HR 221) potentiation of human neutrophil oxygen-independent bactericidal activity.

    Science.gov (United States)

    Labro, M T; Amit, N; Babin-Chevaye, C; Hakim, J

    1987-03-01

    The enhanced bactericidal activity of human neutrophils induced by cefotaxime and cefodizime, two methoxy-imino-amino- 2-thiazolyl cephalosporins, is linked to the cell stimulation of oxygen-dependent and oxygen-independent killing systems, respectively. Cefotaxime enhances both the killing and the oxidative response of neutrophils to opsonized particulate stimuli (bacteria for both activities and opsonized zymosan for the oxidative burst). These effects were not observed with non-opsonized particles (bacteria or zymosan) or soluble stimuli. On the contrary, cefodizime enhances killing of opsonized and non-opsonized bacteria by neutrophils regardless of treatment with phenylbutazone which blocks neutrophil oxidative metabolism. Cefodizime does not universally alter the oxidative burst induced by various stimuli, but has been shown to enhance the bactericidal activity of crude extracts of neutrophil granules. The data suggest that cefodizime and non O2-dependent killing systems of neutrophils cooperate in killing bacteria.

  15. Invasive African Salmonella Typhimurium induces bactericidal antibodies against O-antigens.

    Science.gov (United States)

    Rondini, Simona; Lanzilao, Luisa; Necchi, Francesca; O'Shaughnessy, Colette M; Micoli, Francesca; Saul, Allan; MacLennan, Calman A

    2013-10-01

    Nontyphoidal Salmonella are a major and emerging cause of fatal invasive disease in Africa, and are genetically distinct from those found elsewhere in the world. Understanding the targets of protective immunity to these African Salmonellae is key to vaccine development. We immunized mice and rabbits with heat-inactivated wild-type African invasive Salmonella Typhimurium D23580 and rough mutants lacking O-antigen. Wild-type Salmonella, unlike rough bacteria, induced a large bactericidal antibody response mainly against O-antigen. Bactericidal ability of anti-O-antigen antibodies was confirmed following purification by affinity chromatography. The current findings support the development of an O-antigen conjugate vaccine against invasive nontyphoidal Salmonellae for Africa.

  16. Synthesis and bactericidal activities of novel pyrazole-l-carbothioamide derivatives

    Institute of Scientific and Technical Information of China (English)

    LIU Xinhua; WANG Shifan; SONG Baoan

    2007-01-01

    4-(2-Hydroxy-phenyl)-but-3-en-2-one (1) was prepared via condensation of salicylaldehyde with acetone,and then reaction of the ketone 1 with thiosemicarbazide was accompanied by cyclization to give substituted pyrazole (2).Seven new 5-(2-hydroxy-phenyl)-3-methyl-4,5-dihydropyrazole- 1-carbothioamide derivatives (3a-3g) were synthesized by the acylation of 2 and characterized by means of elemental analysis,infrared (IR),and 1H nuclear magnetic resonance (NMR).The compounds 3c,3d,and 3g showed certain bactericidal activity against E.coli;while compound 3g showed certain bactericidal activity against P.vulgaris.

  17. Bactericidal efficacy of elevated pH on fish pathogenic and environmental bacteria

    Directory of Open Access Journals (Sweden)

    Clifford E. Starliper

    2013-07-01

    Full Text Available Ship ballast water is a recognized medium for transfer and introductions of nonindigenous species. There is a need for new ballast water treatment methods that effectively and safely eliminate or greatly minimize movements of these species. The present study employed laboratory methods to evaluate the bactericidal efficacy of increased pH (pH 10.0–12.0 for exposure durations of up to 72 h to kill a variety of Gram-negative and Gram-positive bacteria including fish pathogens (Aeromonas spp., Yersinia ruckeri, Edwardsiella ictaluri, Serratia liquefaciens, Carnobacterium sp., other common aquatic-inhabitant bacteria (Serratia marcescens, Pseudomonas fluorescens, Staphylococcus sp., Bacillus sp. and indicators listed in International Maritime Organization D2 Standards; namely, Vibrio cholera (an environmental isolate from fish, Escherichia coli and Enterococcus faecalis. Volumes of 5 N NaOH were added to tryptic soy broth to obtain desired pH adjustments. Viable cells were determined after 0, 4, 12, 24, 48, and 72 h. Initial (0 h cell numbers ranged from 3.40 × 104 cfu/mL for Bacillus sp. to 2.44 × 107 cfu/mL for E. faecalis. The effective endpoints of pH and treatment duration necessary to realize 100% bactericidal effect varied; however, all bacteria tested were killed within 72 h at pH 12.0 or lower. The lowest parameters examined, 4 h at pH 10.0, were bactericidal to V. cholera, E. ictaluri, three of four isolates of E. coli, and (three of four Aeromonas salmonicida subsp. salmonicida. Bactericidal effect was attained at pH 10.0 within 12 h for the other A. salmonicida subsp. salmonicida, and within 24 h for P. fluorescens, and the remaining E. coli.

  18. Electrochemical analysis of the UV treated bactericidal Ti6Al4V surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Pacha-Olivenza, Miguel A. [Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Department of Applied Physics, Faculty of Science, University of Extremadura, Av. Elvas s/n, 06071 Badajoz (Spain); Gallardo-Moreno, Amparo M., E-mail: amparogm@unex.es [Department of Applied Physics, Faculty of Science, University of Extremadura, Av. Elvas s/n, 06071 Badajoz (Spain); Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Vadillo-Rodríguez, Virginia; González-Martín, M. Luisa [Department of Applied Physics, Faculty of Science, University of Extremadura, Av. Elvas s/n, 06071 Badajoz (Spain); Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Pérez-Giraldo, Ciro [Department of Microbiology, Faculty of Medicine, University of Extremadura, Av. Elvas s/n, 06071 Badajoz (Spain); Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) (Spain); Galván, Juan C. [National Centre for Metallurgical Research (CENIM-CSIC), Av. Gregorio del Amo 8, 28040-Madrid (Spain)

    2013-04-01

    This research investigates in detail the bactericidal effect exhibited by the surface of the biomaterial Ti6Al4V after being subjected to UV-C light. It has been recently hypothesized that small surface currents, occurring as a consequence of the electron–hole pair recombination taking place after the excitation process, are behind the bactericidal properties displayed by this UV-treated material. To corroborate this hypothesis we have used different electrochemical techniques, such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization plots and Mott–Schottky plots. EIS and Mott–Schottky plots have shown that UV-C treatment causes an initial increase on the surface electrical conduction of this material. In addition, EIS and polarization plots demonstrated that higher corrosion currents occur at the UV treated than at the non-irradiated samples. Despite this increase in the corrosion currents, EIS has also shown that such currents are not likely to affect the good stability of this material oxide film since the irradiated samples completely recovered the control values after being stored in dark conditions for a period not longer than 24 h. These results agree with the already-published in vitro transitory behavior of the bactericidal effect, which was shown to be present at initial times after the biomaterial implantation, a crucial moment to avoid a large number of biomaterial associated infections. Highlights: ► Bactericidal response of UV-treated Ti6Al4V is explained through electrochemistry. ► There is an increase in the superficial electrical conduction after UV-treatment. ► Higher corrosion currents for UV-treated against non-UV-treated samples are shown. ► EIS shows the recuperation on irradiated samples in agreement with microbial tests.

  19. Enhanced bactericidal action of acidified sodium chlorite caused by the saturation of reactants.

    Science.gov (United States)

    Kim, N H; Park, T H; Rhee, M S

    2014-06-01

    Factors affecting the antibacterial action of acidified sodium chlorite (ASC), a widely used disinfectant, have not been determined. This study investigated the significant factors suggesting efficient production method to maximize bactericidal action of ASC. The effects of (i) preparation procedures (total three methods); (ii) initial concentrations of reactants: sodium chlorite (SC) and citric acid (CTA) (up to maximum solubility of each reactant) and (iii) final pH values (3·0 and 2·5) to the bactericidal action of ASC were investigated with a fixed final concentration of SC (10 ppm) using various foodborne pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium and Staphylococcus aureus). The antimicrobial compounds produced and the bactericidal effects depended on the preparation procedure and the initial concentrations of the reactants. The ASC prepared by premixing highly concentrated reactants (in particular > 40%) followed by dilution (dilution after reaction, DAR) was more effective in inactivating foodborne pathogens, and it produced higher antimicrobial compound (Cl(2) and ClO(2)) yields than the other procedures. A 5-min treatment with ASC, produced using the other procedures, resulted in a reduction of < 3·5 log CFU ml(-1) (Gram positive = 0·18-0·78; Gram negative = 0·03-3·49 log CFU ml(-1)), whereas ASC produced with the DAR procedure using the saturated reactants completely inactivated all of the test pathogens within 5 min without recovery (initial concentration = 6·94-7·08 log CFU ml(-1)). The ASC production with the DAR procedure using the saturated reactants maximizes both the antimicrobial compound yields and bactericidal effects of the ASC solutions. This study will contribute to increase the efficiency of ASC treatments for disinfections reducing the effective SC concentrations for industrial use. © 2014 The Society for Applied Microbiology.

  20. Polymeric coatings eliminate the bactericidal effects of Nanoscale zero-valent iron to Escherichia coli

    Science.gov (United States)

    Lowry, G. V.; Gregory, K.; Li, Z.

    2009-12-01

    Nanoscale zero-valent iron (NZVI) particles that are used in aquifer remediation may come in contact with subsurface bacteria, and may adversely affect subsurface bacteria. Studies showed that NZVI is toxic toward E. coli at concentrations as low as a few mg/L. However, NZVI particles used in remediation are coated with polymers or natural organic matter (NOM). It is unclear how these surface coatings may affect the bactericidal properties of NZVI. The objectives of this study were to assess the effect that (i) coatings (both anthropogenic and natural) and (ii) particle oxidative state have on the bactericidal properties of NZVI on a gram-negative bacteria, Escherichia coli. Bacteria (106 cells/L) were exposed to 100 mg/L of bare or coated NZVI for 60 minutes under either aerobic or anaerobic conditions. Bacteria were plated at specified times over 60 minutes to determine the number of viable bacteria in the reactor. Bare NZVI was cytotoxic at only 100 mg/L NZVI with over 5 log kill after 60 minutes of exposure. Exposure under aerobic conditions resulted in less than 1 log kill. The lower bactericidal effects were due to rapid oxidation of the iron to Fe(II) and Fe(III) mineral phases that are not toxic. All organic coatings on NZVI decreased or eliminated NZVI cytotoxicity when exposed at the same NZVI concentrations as in the bare case. The decrease in bactericidal effects of coated NZVI over bare NZVI was due to electrosteric repulsions afforded by the coatings that inhibited contact of NZVI with the bacteria. The inhibition of attachment to bacteria was confirmed with TEM and with NZVI sedimentation studies. Application of coatings may be considered as a means of decreasing the effects of NZVI on subsurface bacteria in field application.

  1. Bactericidal efficacy of elevated pH on fish pathogenic and environmental bacteria

    Science.gov (United States)

    Starliper, Clifford E.; Watten, Barnaby J.

    2013-01-01

    Ship ballast water is a recognized medium for transfer and introductions of nonindigenous species. There is a need for new ballast water treatment methods that effectively and safely eliminate or greatly minimize movements of these species. The present study employed laboratory methods to evaluate the bactericidal efficacy of increased pH (pH 10.0–12.0) for exposure durations of up to 72 h to kill a variety of Gram-negative and Gram-positive bacteria including fish pathogens (Aeromonas spp., Yersinia ruckeri, Edwardsiella ictaluri, Serratia liquefaciens, Carnobacterium sp.), other common aquatic-inhabitant bacteria (Serratia marcescens, Pseudomonas fluorescens, Staphylococcus sp., Bacillus sp.) and indicators listed in International Maritime Organization D2 Standards; namely, Vibrio cholera (an environmental isolate from fish), Escherichia coli and Enterococcus faecalis. Volumes of 5 N NaOH were added to tryptic soy broth to obtain desired pH adjustments. Viable cells were determined after 0, 4, 12, 24, 48, and 72 h. Initial (0 h) cell numbers ranged from 3.40 × 104 cfu/mL for Bacillus sp. to 2.44 × 107 cfu/mL for E. faecalis. The effective endpoints of pH and treatment duration necessary to realize 100% bactericidal effect varied; however, all bacteria tested were killed within 72 h at pH 12.0 or lower. The lowest parameters examined, 4 h at pH 10.0, were bactericidal to V. cholera, E. ictaluri, three of four isolates of E. coli, and (three of four) Aeromonas salmonicida subsp. salmonicida. Bactericidal effect was attained at pH 10.0 within 12 h for the other A. salmonicida subsp. salmonicida, and within 24 h for P. fluorescens, and the remaining E. coli.

  2. Evaluation of the bactericidal activity of Telavancin against Staphylococcus aureus using revised testing guidelines.

    Science.gov (United States)

    Sweeney, Debora; Shinabarger, Dean L; Smart, Jennifer I; Bruss, Jon; Pillar, Chris M

    2017-09-01

    The in vitro broth microdilution testing method for telavancin, a lipoglycopeptide active against S. aureus, was revised in 2014 to include polysorbate-80 in the test media. This study evaluates the bactericidal activity of telavancin against S. aureus in media containing polysorbate-80 by in vitro time-kill analysis alongside relevant comparators. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Microarray