Evaluation of biocidal efficacy of copper alloy coatings in comparison with solid metal surfaces: generation of organic copper phosphate nanoflowers.

PubMed

Gutierrez, H; Portman, T; Pershin, V; Ringuette, M

2013-03-01

To analyse the biocidal efficacy of thermal sprayed copper surfaces. Copper alloy sheet metals containing >60% copper have been shown to exhibit potent biocidal activity. Surface biocidal activity was assessed by epifluorescence microscopy. After 2-h exposure at 20 °C in phosphate-buffered saline (PBS), contact killing of Gram-negative Escherichia coli and Gram-positive Staphylococcus epidermidis by brass sheet metal and phosphor bronze was 3-4-times higher than that by stainless steel. SEM observations revealed that the surface membranes of both bacterial strains were slightly more irregular when exposed to brass sheet metal than stainless steel. However, when exposed to phosphor bronze coating, E. coli were 3-4 times larger with irregular membrane morphology. In addition, the majority of the cells were associated with spherical carbon-copper-phosphate crystalline nanostructures characteristic of nanoflowers. The membranes of many of the S. epidermidis exhibited blebbing, and a small subset was also associated with nanoflowers. Our data indicate that increasing the surface roughness of copper alloys had a pronounced impact on the membrane integrity of Gram-positive and, to a lesser degree, Gram-negative bacteria. In the presence of PBS, carbon-copper-phosphate-containing nanoflowers were formed, likely nucleated by components derived from killed bacteria. The intimate association of the bacteria with the nanoflowers and phosphor bronze coating likely contributed to their nonreversible adhesion. Thermal spraying of copper alloys provides a strategy for the rapid coating of three-dimensional organic and inorganic surfaces with biocidal copper alloys. Our study demonstrates that the macroscale surface roughness generated by the thermal spray process enhances the biocidal activity of copper alloys compared with the nanoscale surface roughness of copper sheet metals. Moreover, the coating surface topography provides conditions for the rapid formation of organic copper phosphate nanocrystals/nanoflowers. © 2012 The Society for Applied Microbiology.

Biofilm Inhibition by Novel Natural Product- and Biocide-Containing Coatings Using High-Throughput Screening.

PubMed

Salta, Maria; Dennington, Simon P; Wharton, Julian A

2018-05-10

The use of natural products (NPs) as possible alternative biocidal compounds for use in antifouling coatings has been the focus of research over the past decades. Despite the importance of this field, the efficacy of a given NP against biofilm (mainly bacteria and diatoms) formation is tested with the NP being in solution, while almost no studies test the effect of an NP once incorporated into a coating system. The development of a novel bioassay to assess the activity of NP-containing and biocide-containing coatings against marine biofilm formation has been achieved using a high-throughput microplate reader and highly sensitive confocal laser scanning microscopy (CLSM), as well as nucleic acid staining. Juglone, an isolated NP that has previously shown efficacy against bacterial attachment, was incorporated into a simple coating matrix. Biofilm formation over 48 h was assessed and compared against coatings containing the NP and the commonly used booster biocide, cuprous oxide. Leaching of the NP from the coating was quantified at two time points, 24 h and 48 h, showing evidence of both juglone and cuprous oxide being released. Results from the microplate reader showed that the NP coatings exhibited antifouling efficacy, significantly inhibiting biofilm formation when compared to the control coatings, while NP coatings and the cuprous oxide coatings performed equally well. CLSM results and COMSTAT analysis on biofilm 3D morphology showed comparable results when the NP coatings were tested against the controls, with higher biofilm biovolume and maximum thickness being found on the controls. This new method proved to be repeatable and insightful and we believe it is applicable in antifouling and other numerous applications where interactions between biofilm formation and surfaces is of interest.

Antimicrobial biocides in the healthcare environment: efficacy, usage, policies, and perceived problems.

PubMed

Maillard, Jean-Yves

2005-12-01

Biocides are heavily used in the healthcare environment, mainly for the disinfection of surfaces, water, equipment, and antisepsis, but also for the sterilization of medical devices and preservation of pharmaceutical and medicinal products. The number of biocidal products for such usage continuously increases along with the number of applications, although some are prone to controversies. There are hundreds of products containing low concentrations of biocides, including various fabrics such as linen, curtains, mattresses, and mops that claim to help control infection, although evidence has not been evaluated in practice. Concurrently, the incidence of hospital-associated infections (HAIs) caused notably by bacterial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) remains high. The intensive use of biocides is the subject of current debate. Some professionals would like to see an increase in their use throughout hospitals, whereas others call for a restriction in their usage to where the risk of pathogen transmission to patients is high. In addition, the possible linkage between biocide and antibiotic resistance in bacteria and the role of biocides in the emergence of such resistance has provided more controversies in their extensive and indiscriminate usage. When used appropriately, biocidal products have a very important role to play in the control of HAIs. This paper discusses the benefits and problems associated with the use of biocides in the healthcare environment and provides a constructive view on their overall usefulness in the hospital setting.

Antibacterial surface design - Contact kill

NASA Astrophysics Data System (ADS)

Kaur, Rajbir; Liu, Song

2016-08-01

Designing antibacterial surfaces has become extremely important to minimize Healthcare Associated Infections which are a major cause of mortality worldwide. A previous biocide-releasing approach is based on leaching of encapsulated biocides such as silver and triclosan which exerts negative impacts on the environment and potentially contributes to the development of bacterial resistance. This drawback of leachable compounds led to the shift of interest towards a more sustainable and environmentally friendly approach: contact-killing surfaces. Biocides that can be bound onto surfaces to give the substrates contact-active antibacterial activity include quaternary ammonium compounds (QACs), quaternary phosphoniums (QPs), carbon nanotubes, antibacterial peptides, and N-chloramines. Among the above, QACs and N-chloramines are the most researched contact-active biocides. We review the engineering of contact-active surfaces using QACs or N-chloramines, the modes of actions as well as the test methods. The charge-density threshold of cationic surfaces for desired antibacterial efficacy and attempts to combine various biocides for the generation of new contact-active surfaces are discussed in detail. Surface positive charge density is identified as a key parameter to define antibacterial efficacy. We expect that this research field will continue to attract more research interest in view of the potential impact of self-disinfective surfaces on healthcare-associated infections, food safety and corrosion/fouling resistance required on industrial surfaces such as oil pipes and ship hulls.

Laboratory observations of biocide efficiency against Legionella in model cooling tower systems

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

Thomas, W.M.; Eccles, J.; Fricker, C.

1999-07-01

The efficacy of specific oxidizing and non-oxidizing biocides was examined using a model cooling system inoculated with a microcosm containing an environmental isolate of Legionella pneumophila. The microcosm was prepared in a two-stage chemostat, which provided a consistent source of microbiological inoculum for the study. The microcosm consisted of both sessile (within biofilms) and planktonic Legionella in association with other microorganisms, including Pseudomonas species and cyst-forming ameobae. A procedure was established to successfully transfer the chemostat grown inoculum to the model cooling system and establish both sessile and planktonic forms of Legionella in the model cooling system. The greatest biocidalmore » effect for all of the biocides was observed immediately after dosing. This effect was relatively short-lived even for the slow acting biocides such isothiazolin (as 8 ppm active) where an effect was only observed over the first 12 hours. The faster acting biocides, DBNPA (as 8 ppm active) and gluteraldehyde (as 27 ppm active), did initially reduce Legionella populations but did not totally eliminate Legionella or provide lasting control. Chlorine and bromine (as 0.5--1.5 ppm free halogen), and ozone (as 0.1--0.5 ppm free reserve) reduced and controlled Legionella populations so long as a free reserve of oxidant was maintained. Legionella recovered quickly after biocide dosing, reestablishing similar levels to those observed before dosing.« less

Preparation, bioactivity, and application of novel biocidal materials

NASA Astrophysics Data System (ADS)

Wu, Rong

In this study, several novel N-halamine precursors were synthesized. These surface coupling agents were bonded to the surfaces of cotton fabric, cotton gauze, paper, glass, and sand. Once they were activated using household bleach, the surfaces and materials became biocidal. Possible uses for the biocidal cotton are in protective garments for hospital personnel and those who must fight against bioterrorism. The treated cotton gauze may be used to make an antimicrobial mask to stop infective pathogen transcontamination. Biocidal sand has the potential to be used as a disinfectant in a filter for wastewater or municipal water treatment. In fact, the N-halamine siloxanes can be applied to many other surfaces. The results of biocidal efficacy of some of the treated surfaces will be presented in this study. Several new hydantoinyl diols and quaternary ammonium hydantoinyl diols were prepared in this work also. They were copolymerized with commercial water borne acrylic polyol and commercial isocyanate to form polyurethane coatings. The biocidal polyurethane coatings were produced after activation by chlorination. Those diols also reacted with a two-component epoxy paint to render the paint antimicrobial. Several novel biocidal polymeric resins were synthesized by attachment of N-halamine moieties to the commercial polymer supported beads such as Merrifield resin and Amberlite IRA-67 ionic resin. The Merrifield resin and Amberlite IRA-67 ionic resin also were grafted with N-halamine functionality as well as with the N,N-dimethyl-dodecylamine moiety via 1,2-dichloroethane. Finally, several quaternary ammonium N-halamine polymers were prepared. Direct copolymerization of (triethoxysilyl)propyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro-[4,5]-decane-2,4-dione (TTDD-Si), or 3-(trimethoxysilyl)propyl-5,5-dimethylhydantoin (BA-1 ') with 3-(trimethoxysilylpropyl)dimethyloctadecyl ammonium chloride (DC 5700) produced dual functionality and water soluble biocidal materials and surfaces. (Abstract shortened by UMI.)

Stimulatory effect of cooling tower biocides on amoebae.

PubMed

Srikanth, S; Berk, S G

1993-10-01

Two species of amoebae were isolated from the cooling tower of an air-conditioning system and examined for effects of exposure to four cooling tower biocides, a thiocarbamate compound, tributyltin neodecanoate mixed with quaternary ammonium compounds, another quaternary ammonium compound alone, and an isothiazolin derivative. The amoebae isolated were Acanthamoeba hatchetti and a Cochliopodium species. Two other amoeba cultures, an A. hatchetti culture and Cochliopodium bilimbosum, were obtained from the American Type Culture Collection (ATCC) and were also tested. The cooling tower isolates were more resistant to most of the biocides than the ATCC isolates were. The isothiazolin derivative was the least inhibitory to all four amoeba isolates, and tributyltin neodecanoate mixed with quaternary ammonium compounds was the most inhibitory to three of the four isolates. After exposure to lower concentrations of the biocides, including for one strain the manufacturer's recommended concentration of one biocide, the cooling tower amoeba populations increased significantly compared with unexposed controls, whereas the ATCC isolates were not stimulated at any of the concentrations tested. In some cases, concentrations which stimulated cooling tower amoebae inhibited the growth of the ATCC isolates. These results suggest that cooling tower amoebae may adapt to biocides, underscoring the need to use freshly isolated cooling tower organisms rather than organisms from culture collections for testing the efficacy of such biocides. The stimulatory effect of biocides on amoeba populations is an alarming observation, since these organisms may be reservoirs for legionellae. Biocides used to control microbial growth may actually enhance populations of host organisms for pathogenic bacteria.

Antimicrobial biocides in the healthcare environment: efficacy, usage, policies, and perceived problems

PubMed Central

Maillard, Jean-Yves

2005-01-01

Biocides are heavily used in the healthcare environment, mainly for the disinfection of surfaces, water, equipment, and antisepsis, but also for the sterilization of medical devices and preservation of pharmaceutical and medicinal products. The number of biocidal products for such usage continuously increases along with the number of applications, although some are prone to controversies. There are hundreds of products containing low concentrations of biocides, including various fabrics such as linen, curtains, mattresses, and mops that claim to help control infection, although evidence has not been evaluated in practice. Concurrently, the incidence of hospital-associated infections (HAIs) caused notably by bacterial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) remains high. The intensive use of biocides is the subject of current debate. Some professionals would like to see an increase in their use throughout hospitals, whereas others call for a restriction in their usage to where the risk of pathogen transmission to patients is high. In addition, the possible linkage between biocide and antibiotic resistance in bacteria and the role of biocides in the emergence of such resistance has provided more controversies in their extensive and indiscriminate usage. When used appropriately, biocidal products have a very important role to play in the control of HAIs. This paper discusses the benefits and problems associated with the use of biocides in the healthcare environment and provides a constructive view on their overall usefulness in the hospital setting. PMID:18360573

Antimicrobial efficacy of a novel eucalyptus oil, chlorhexidine digluconate and isopropyl alcohol biocide formulation.

PubMed

Hendry, Emma; Conway, Barbara; Worthington, Tony

2012-10-30

Effective surface disinfection is a fundamental infection control strategy within healthcare. This study assessed the antimicrobial efficacy of novel biocide formulations comprising 5% and 2% eucalyptus oil (EO) combined with 2% chlorhexidine digluconate (CHG) and 70% isopropyl alcohol (IPA) contained within a wipe. The efficacy of this novel antimicrobial formulation to remove and eliminate methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Candida albicans from steel surfaces was investigated. Adpression studies of pre-contaminated wipes were also utilised to assess their potential to induce cross-contamination between hard surfaces. Furthermore, the bactericidal nature of the EO-formulation was established in addition to time-kill. The EO-containing formulations demonstrated bactericidal antimicrobial efficacy against all microorganisms and did not induce surface cross-contamination. There was no significant difference (p < 0.05) between the 5% and 2% EO formulations in their ability to remove microorganisms from steel surfaces, however both significantly (p < 0.05) removed more than the control formulations. Microbial biofilms were eliminated within 10 min (p < 0.05) when exposed to the EO formulations. Our novel EO-formulation demonstrated rapid antimicrobial efficacy for potential disinfection and elimination of microbial biofilms from hard surfaces and may therefore be a useful adjunct to current infection control strategies currently employed within healthcare facilities.

Antimicrobial Efficacy of a Novel Eucalyptus Oil, Chlorhexidine Digluconate and Isopropyl Alcohol Biocide Formulation

PubMed Central

Hendry, Emma; Conway, Barbara; Worthington, Tony

2012-01-01

Effective surface disinfection is a fundamental infection control strategy within healthcare. This study assessed the antimicrobial efficacy of novel biocide formulations comprising 5% and 2% eucalyptus oil (EO) combined with 2% chlorhexidine digluconate (CHG) and 70% isopropyl alcohol (IPA) contained within a wipe. The efficacy of this novel antimicrobial formulation to remove and eliminate methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Candida albicans from steel surfaces was investigated. Adpression studies of pre-contaminated wipes were also utilised to assess their potential to induce cross-contamination between hard surfaces. Furthermore, the bactericidal nature of the EO-formulation was established in addition to time-kill. The EO-containing formulations demonstrated bactericidal antimicrobial efficacy against all microorganisms and did not induce surface cross-contamination. There was no significant difference (p < 0.05) between the 5% and 2% EO formulations in their ability to remove microorganisms from steel surfaces, however both significantly (p < 0.05) removed more than the control formulations. Microbial biofilms were eliminated within 10 min (p < 0.05) when exposed to the EO formulations. Our novel EO-formulation demonstrated rapid antimicrobial efficacy for potential disinfection and elimination of microbial biofilms from hard surfaces and may therefore be a useful adjunct to current infection control strategies currently employed within healthcare facilities. PMID:23203047

Choice of optimal biocide combination to control flies (Diptera: Muscidae).

PubMed

Kavran, Mihaela; Zgomba, Marija F; Ignjatovic-Ćupina, Aleksandra M; Lazić, Sanja D; Petrić, Dušan V

2015-01-01

Flies - by feeding on decaying matter, human waste and food - have been implicated in the spread of numerous animal and human diseases. Excessive fly populations are generally associated with livestock units and domestic waste due to decaying organic matter. A large number of flies cause extreme disturbance in the behavior of the host, resulting in skin irritation, lesions, wounds, and secondary infections are likely to appear. The aim of this study was to evaluate the effects of combined applications of larvicide (cyromazine) and adulticides (acetamiprid in formulation with pheromone and thiamethoxam) on the suppression of fly populations. The study was conducted on a pig farm. The piglet farms are one of the most favorable places for fly breeding. Three units were used for biocide applications and a fourth unit as the control where biocides were not applied. The monitoring of pre- and post-treatment of adult fly populations was carried out by glued cardboards. The cards were hung on metal rods above piglet's cage. This monitoring method served as a parameter for the estimation of biological effectiveness. The highest degree of fly control (88.4% mortality 8 days after treatment) was achieved when a combination of cyromazine and thiamethoxam was used. A biocide based on sex pheromone (Z)-9-tricosene + acetamiprid was the most effective on flies 3 days after biocide application, with a mortality rate of 69.1 %. Thiamethoxam achieved the highest reduction of flies 6 days after treatment, with 78.19% obtained mortality. Biological efficacy of the applied biocides in combination ciromazine + thiamethoxam and thiamethoxam alone was justified.

Evaluation of the Biocidal Efficacy of Different Forms of Silver Against Cupriavidus (formerly Wautersia) Species Bacteria

NASA Technical Reports Server (NTRS)

Gazda, Daniel B.; Schultz, John R.; Wong, Wing; Algate, Michelle T.; Bryant, Becky; Castro, Victoria A.

2009-01-01

Contingency Water Containers (CWCs) are used to store potable and technical water that is transferred to the International Space Station (ISS) from the Shuttle orbiter vehicles. When CWCs are filled, water from the orbiter galley is passed through an ion exchange/activated carbon cartridge that removes the residual iodine biocide used on Shuttle before silver biocide is added. Removal of iodine and addition of silver is necessary to inhibit microbial growth inside CWCs and maintain compatibility with the water systems in the Russian segment of ISS. As part of nominal water transfer activities, crewmembers collect samples from several CWCs for postflight analysis. Results from the analysis of water transfer samples collected during the docked phases of STS-118/13A.1 and STS-120/10A showed that several of the CWCs contained up to 10(exp 4) CFU/mL of bacteria despite the fact that the silver concentrations in the CWCs were within acceptable limits. The samples contained pure cultures of a single bacteria, a Cupriavidus (formerly Wautersia) species that has been shown to be resistant to metallic biocides. As part of the investigation into the cause and remediation of the bacterial contamination in these CWCs, ground studies were initiated to evaluate the resistance of the Cupriavidus species to the silver biocides used on ISS and to determine the minimum effective concentration for the different forms of silver present in the biocides. The initial findings from those experiments are discussed herein.

Effects of Material Choice on Biocide Loss in Orion Water Storage Tanks

NASA Technical Reports Server (NTRS)

Wallace, W. T.; Wallace, S. L.; Gazda, D. B.; Lewis, J. F.

2016-01-01

When preparing for long-duration spaceflight missions, maintaining a safe supply of potable water is of the utmost importance. One major aspect of that is ensuring that microbial growth is minimized. Historically, this challenge has been addressed through the use of biocides. When using biocides, the choice of materials for the storage containers is important, because surface reactions can reduce biocide concentrations below their effective range. In the water storage system baselined for the Orion vehicle, the primary wetted materials are stainless steel (316 L) and a titanium alloy (Ti6Al4V). Previous testing with these materials has shown that the biocide selected for use in the system (ionic silver) will plate out rapidly upon initial wetting of the system. One potential approach for maintaining an adequate biocide concentration is to spike the water supply with high levels of biocide in an attempt to passivate the surface. To evaluate this hypothesis, samples of the wetted materials were tested individually and together to determine the relative loss of biocide under representative surface area-to-volume ratios after 24 hours. Additionally, we have analyzed the efficacy of disinfecting a system containing these materials by measuring reductions in bacterial counts in the same test conditions. Preliminary results indicate that the use of titanium, either individually or in combination with stainless steel, can result in over 95% loss of biocide, while less than 5% is lost when using stainless steel. In bacterial testing, viable organisms were recovered from samples exposed to the titanium coupons after 24 hours. By comparison, no organisms were recovered from the test vessels containing only stainless steel. These results indicate that titanium, while possessing some favorable attributes, may pose additional challenges when used in water storage tanks with ionic silver biocide.

Evaluation of Electrochemically Generated Potable Water Disinfectants for Use on the International Space Station

NASA Technical Reports Server (NTRS)

Rodriquez, Branelle; Anderson, Molly; Adams, Niklas; Vega, Leticia; Botkin, Douglas

2013-01-01

Microbial contamination and subsequent growth in spacecraft water systems are constant concerns for missions involving human crews. The current potable water disinfectant for the International Space Station (ISS) is iodine; however, with the end of the Space Shuttle Program, there is a need to develop redundant biocide systems that do not require regular up-mass dependencies. Throughout the course of a year, four different electrochemical systems were investigated as a possible biocide for potable water on the ISS. Research has indicated that a wide variability exists with regards to efficacy in both concentration and exposure time of these disinfectants; therefore, baseline efficacy values were established. This paper describes a series of tests performed to establish optimal concentrations and exposure times for four disinfectants against single and mixed species planktonic and biofilm bacteria. Results of the testing determined whether these electrochemical disinfection systems are able to produce a sufficient amount of chemical in both concentration and volume to act as a biocide for potable water on the ISS.

Settlement of the alien mollusc Brachidontes pharaonis in a Mediterranean industrial plant: bioassays for antifouling treatment optimization and management.

PubMed

Garaventa, F; Corrà, C; Piazza, V; Giacco, E; Greco, G; Pane, L; Faimali, M

2012-05-01

In this work, we investigated the efficacy of three new biocides (77351, 73532, 73503--NALCO®) as specific antifouling products against adult organisms of the bivalve Brachidontes pharaonis (Fischer P., 1870), a Lessepsian species introduced in the Mediterranean Sea by sea transport (ballast water), and which has recently shown invasive behaviour in an industrial plant in Southern Italy (Sicily). These biocides were tested to verify their efficacy, as well as their environmental compatibility at discharge point, using the crustacean belonging to the genus Artemia (Leach, 1819) as model organism, according to Government Decree (D. Lgs) No. 152/06. Biocides were also tested using alternative crustaceans, Amphibalanus amphitrite (Darwin, 1854), and Tigriopus fulvus (Fischer, 1860), in order to check whether their introduction as model species in the national regulation could affect discharge limit concentrations (DLC) due to their different sensitivity, with likely economic and technical repercussions in the industrial water treatment sector. Copyright © 2011 Elsevier Ltd. All rights reserved.

Evaluation of Electrochemically Generated Potable Water Disinfectants for Use on the International Space Station

NASA Technical Reports Server (NTRS)

Rodriquez, Branelle; Anderson, Molly; Anderson, Molly; Adam, Niklas; Vega, Leticia; Modica, Catherine; Bodkin, Douglas

2012-01-01

Microbial contamination and subsequent growth in spacecraft water systems are constant concerns for missions involving human crews. The current potable water disinfectant for the International Space Station (ISS) is iodine; however, with the end of the Space Shuttle program, there is a need to develop redundant biocide systems that do not require regular up ]mass dependencies. Throughout the course of a year, four different electrochemical systems were investigated as a possible biocide for potable water on the ISS. Research has indicated that there is a wide variability with regards to efficacy in both concentration and exposure time of these disinfectants, therefore baseline efficacy values were established. This paper describes a series of tests performed in order to establish optimal concentrations and exposure times for four disinfectants against single and mixed species planktonic and biofilm bacteria. Results of the testing determined whether these electrochemical disinfection systems are able to produce a sufficient amount of chemical in both concentration and volume to act as a biocide for potable water on ISS.

Efficiency of four currently used decontamination conditionings in Romania against Aspergillus and Candida strains.

PubMed

Lorin, D; Cristina, R T; Teusdea, V; Mitrănescu, E; Muselin, F; Butnariu, M; David, G; Dumitrescu, E

2017-09-01

Efficacy of four commercial biocidal products (noted A to D), using manufacturers' recommendations, and a contact time of 30minutes, were evaluated in the purpose of standard SR EN1657: 2006 adapted. Were used four strains, two as reference: Aspergillus brasiliensis (niger) (ATCC 16404) and Candida albicans (ATCC 10231), and two isolates: Aspergillus flavus and respectively Aspergillus fumigatus. The inoculum plates containing Malt Extract Agar (MEA) were incubated 48h for C. albicans and 72hours for Aspergillus spp. The standard SR EN1657: 2006 adapted was conducted in two phases: the test cultures preparation and the method validation. Method validation included: the control of experimental conditions and of neutralizant solution, and the method verification. Results revealed that three from the four tested products (A, B and D) had exerted biocidal effect on the studied strains at the recommended concentrations, the registered CFU values being reduced by more than 4 log 10 , conversely in the case of the product (C), applied against A. fumigatus at the recommended concentration of 2%, the biocidal effect was not detected, fact confirmed also by the CFU's value (3.59 log 10 ). The biocide retested at a greater concentration (of 5%), showed a biocidal effect against A. fumigatus after 30minutes, the CFU value being reduced, by more than 5.29 log 10 , evidencing the resistance emergence of A. fumigatus under the repeated pressure of biocides. It is re-confirming that merely the "chemical" defense measures to defuse the fungi's strategies become unproductive. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Modification of the surfaces of medical devices to prevent microbial adhesion and biofilm formation.

PubMed

Desrousseaux, C; Sautou, V; Descamps, S; Traoré, O

2013-10-01

The development of devices with surfaces that have an effect against microbial adhesion or viability is a promising approach to the prevention of device-related infections. To review the strategies used to design devices with surfaces able to limit microbial adhesion and/or growth. A PubMed search of the published literature. One strategy is to design medical devices with a biocidal agent. Biocides can be incorporated into the materials or coated or covalently bonded, resulting either in release of the biocide or in contact killing without release of the biocide. The use of biocides in medical devices is debated because of the risk of bacterial resistance and potential toxicity. Another strategy is to modify the chemical or physical surface properties of the materials to prevent microbial adhesion, a complex phenomenon that also depends directly on microbial biological structure and the environment. Anti-adhesive chemical surface modifications mostly target the hydrophobicity features of the materials. Topographical modifications are focused on roughness and nanostructures, whose size and spatial organization are controlled. The most effective physical parameters to reduce bacterial adhesion remain to be determined and could depend on shape and other bacterial characteristics. A prevention strategy based on reducing microbial attachment rather than on releasing a biocide is promising. Evidence of the clinical efficacy of these surface-modified devices is lacking. Additional studies are needed to determine which physical features have the greatest potential for reducing adhesion and to assess the usefulness of antimicrobial coatings other than antibiotics. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Enhanced Biocide Treatments with D-amino Acid Mixtures against a Biofilm Consortium from a Water Cooling Tower.

PubMed

Jia, Ru; Li, Yingchao; Al-Mahamedh, Hussain H; Gu, Tingyue

2017-01-01

Different species of microbes form mixed-culture biofilms in cooling water systems. They cause microbiologically influenced corrosion (MIC) and biofouling, leading to increased operational and maintenance costs. In this work, two D-amino acid mixtures were found to enhance two non-oxidizing biocides [tetrakis hydroxymethyl phosphonium sulfate (THPS) and NALCO 7330 (isothiazoline derivatives)] and one oxidizing biocide [bleach (NaClO)] against a biofilm consortium from a water cooling tower in lab tests. Fifty ppm (w/w) of an equimass mixture of D-methionine, D-leucine, D-tyrosine, D-tryptophan, D-serine, D-threonine, D-phenylalanine, and D-valine (D8) enhanced 15 ppm THPS and 15 ppm NALCO 7330 with similar efficacies achieved by the 30 ppm THPS alone treatment and the 30 ppm NALCO 7330 alone treatment, respectively in the single-batch 3-h biofilm removal test. A sequential treatment method was used to enhance bleach because D-amino acids react with bleach. After a 4-h biofilm removal test, the sequential treatment of 5 ppm bleach followed by 50 ppm D8 achieved extra 1-log reduction in sessile cell counts of acid producing bacteria, sulfate reducing bacteria, and general heterotrophic bacteria compared with the 5 ppm bleach alone treatment. The 10 ppm bleach alone treatment showed a similar efficacy with the sequential treatment of 5 ppm bleach followed by 50 ppm D8. The efficacy of D8 was found better than that of D4 (an equimass mixture of D-methionine, D-leucine, D-tyrosine, and D-tryptophan) in the enhancement of the three individual biocides against the biofilm consortium.

Enhanced Biocide Treatments with D-amino Acid Mixtures against a Biofilm Consortium from a Water Cooling Tower

PubMed Central

Jia, Ru; Li, Yingchao; Al-Mahamedh, Hussain H.; Gu, Tingyue

2017-01-01

Different species of microbes form mixed-culture biofilms in cooling water systems. They cause microbiologically influenced corrosion (MIC) and biofouling, leading to increased operational and maintenance costs. In this work, two D-amino acid mixtures were found to enhance two non-oxidizing biocides [tetrakis hydroxymethyl phosphonium sulfate (THPS) and NALCO 7330 (isothiazoline derivatives)] and one oxidizing biocide [bleach (NaClO)] against a biofilm consortium from a water cooling tower in lab tests. Fifty ppm (w/w) of an equimass mixture of D-methionine, D-leucine, D-tyrosine, D-tryptophan, D-serine, D-threonine, D-phenylalanine, and D-valine (D8) enhanced 15 ppm THPS and 15 ppm NALCO 7330 with similar efficacies achieved by the 30 ppm THPS alone treatment and the 30 ppm NALCO 7330 alone treatment, respectively in the single-batch 3-h biofilm removal test. A sequential treatment method was used to enhance bleach because D-amino acids react with bleach. After a 4-h biofilm removal test, the sequential treatment of 5 ppm bleach followed by 50 ppm D8 achieved extra 1-log reduction in sessile cell counts of acid producing bacteria, sulfate reducing bacteria, and general heterotrophic bacteria compared with the 5 ppm bleach alone treatment. The 10 ppm bleach alone treatment showed a similar efficacy with the sequential treatment of 5 ppm bleach followed by 50 ppm D8. The efficacy of D8 was found better than that of D4 (an equimass mixture of D-methionine, D-leucine, D-tyrosine, and D-tryptophan) in the enhancement of the three individual biocides against the biofilm consortium. PMID:28861053

Innate resistance to sporicides and potential failure to decontaminate.

PubMed

Maillard, J-Y

2011-03-01

Bacterial spores are frequently intrinsically resistant to biocides and only a number of alkylating and oxidising biocides are sporicidal under certain conditions. Activity against spores is affected by several key factors such as concentration, exposure time, soiling, and the types of surface to be treated. Sporicidal efficacy is usually achieved after an exposure time of several minutes with a high concentration of a biocide. Failure to understand these factors will result in decreased sporicide activity and spore survival. Sporicides in healthcare settings are used for surface disinfection and for the high level disinfection of certain medical devices (e.g. endoscopes). With efficacy data in mind, sporicidal activity should be achieved for the disinfection of medical devices where both high concentration and long exposure time occur. However, for the disinfection of environmental surfaces, high concentration is not recommended, nor is long exposure time achievable. In this case, sporicidal activity is severely reduced and spore survival following treatment is to be expected and contributes to the explanation of spore persistence on surfaces. Copyright © 2010 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.

Enhanced Inactivation of Escherichia coli and MS2 Coliphage by Cupric Ion in the Presence of Hydroxylamine: Dual Microbicidal Effects.

PubMed

Kim, Hyung-Eun; Nguyen, Thuy T M; Lee, Hongshin; Lee, Changha

2015-12-15

The inactivation of Escherichia coli and MS2 coliphage by Cu(II) is found to be significantly enhanced in the presence of hydroxylamine (HA). The addition of a small amount of HA (i.e., 5-20 μM) increased the inactivation efficacies of E. coli and MS2 coliphage by 5- to 100-fold, depending on the conditions. Dual effects were anticipated to enhance the biocidal activity of Cu(II) by the addition of HA, viz. (i) the accelerated reduction of Cu(II) into Cu(I) (a stronger biocide) and (ii) the production of reactive oxidants from the reaction of Cu(I) with dissolved oxygen (evidenced by the oxidative transformation of methanol into formaldehyde). Deaeration enhanced the inactivation of E. coli but slightly decreased the inactivation efficacy of MS2 coliphage. The addition of 10 μM hydrogen peroxide (H2O2) greatly enhanced the MS2 inactivation, whereas the same concentration of H2O2 did not significantly affect the inactivation efficacy of E. coli Observations collectively indicate that different biocidal actions lead to the inactivation of E. coli and MS2 coliphage. The toxicity of Cu(I) is dominantly responsible for the E. coli inactivation. However, for the MS2 coliphage inactivation, the oxidative damage induced by reactive oxidants is as important as the effect of Cu(I).

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

PubMed

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.

Study of archaeological underwater finds: deterioration and conservation

NASA Astrophysics Data System (ADS)

Crisci, G. M.; La Russa, M. F.; Macchione, M.; Malagodi, M.; Palermo, A. M.; Ruffolo, S. A.

2010-09-01

This study is aimed at an assessment of the methodologies, instruments and new applications for underwater archaeology. Research focused on study of the various kinds of degradation affecting underwater finds and stone materials aged in underwater environment, efficiency evaluation of various surface cleaning methods and study and mixing of protective products with consolidating resins and antimicrobial biocides to be applied to restored underwater finds. Transmitted light optical microscopy and scanning electron microscopy (SEM) were used to study surface biofilms and the interactions with samples of different stone materials such as brick, marble and granite immersed in the submarine archaeological area of Crotone (South of Italy). Surface cleaning tests were performed with application of ion exchange resins, EDTA, hydrogen peroxide and ultrasound techniques. Capillary water absorption, simulated solar ageing and colourimetric measurements were carried out to evaluate hydrophobic and consolidant properties; to assess biocidal efficacy, heterotrophic micro-organisms ( Aspergillus niger) were inoculated on agar plates and growth inhibition was measured.

Controlling the invasive diatom Didymosphenia geminata: an ecotoxicity assessment of four potential biocides.

PubMed

Jellyman, P G; Clearwater, S J; Clayton, J S; Kilroy, C; Blair, N; Hickey, C W; Biggs, B J F

2011-07-01

In 2004, an invasive mat-forming freshwater diatom, Didymosphenia geminata (didymo), was found in New Zealand causing concern with regard to potential consequences for local freshwater ecosystems. A four-stage research program was initiated to identify methods to control D. geminata. This article reports the results of Stage 2, in which four potential control compounds [Gemex™ (a chelated copper formulation), EDTA, Hydrothol®191, and Organic Interceptor™ (a pine oil formulation)] selected in Stage 1 were evaluated for their biocidal efficacy on D. geminata and effects on non-target organisms using both artificial stream and laboratory trials. Artificial stream trials evaluated the mortality rates of D. geminata and fishes to three concentrations of the four biocides, whereas laboratory toxicity trials tested the response of green alga and cladocera to a range of biocide concentrations and exposure times. In artificial stream trials, Gemex and Organic Interceptor were the most effective biocides against D. geminata for a number of measured indices; however, exposure of fishes to Organic Interceptor resulted in high mortality rates. Laboratory toxicity testing indicated that Gemex might negatively affect sensitive stream invertebrates, based on the cladoceran sensitivity at the proposed river control dose. A decision support matrix evaluated the four biocides based on nine criteria stipulated by river stakeholders (effectiveness, non-target species impacts, stalk removal, degradation profile, risks to health and safety, ease of application, neutralization potential, cost, and local regulatory requirements) and Gemex was identified as the product warranting further refinement prior to an in-river trial.

Daylight-driven rechargeable antibacterial and antiviral nanofibrous membranes for bioprotective applications

PubMed Central

Si, Yang; Zhang, Zheng; Wu, Wanrong; Fu, Qiuxia; Huang, Kang; Nitin, Nitin; Ding, Bin; Sun, Gang

2018-01-01

Emerging infectious diseases (EIDs) are a significant burden on global economies and public health. Most present personal protective equipment used to prevent EID transmission and infections is typically devoid of antimicrobial activity. We report on green bioprotective nanofibrous membranes (RNMs) with rechargeable antibacterial and antiviral activities that can effectively produce biocidal reactive oxygen species (ROS) solely driven by the daylight. The premise of the design is that the photoactive RNMs can store the biocidal activity under light irradiation and readily release ROS under dim light or dark conditions, making the biocidal function “always online.” The resulting RNMs exhibit integrated properties of fast ROS production, ease of activity storing, long-term durability, robust breathability, interception of fine particles (>99%), and high bactericidal (>99.9999%) and virucidal (>99.999%) efficacy, which enabled to serve as a scalable biocidal layer for protective equipment by providing contact killing against pathogens either in aerosol or in liquid forms. The successful synthesis of these fascinating materials may provide new insights into the development of protection materials in a sustainable, self-recharging, and structurally adaptive form. PMID:29556532

An evaluation of the efficacy of Aqualox for microbiological control of industrial cooling tower systems.

PubMed

Prince, E L; Muir, A V G; Thomas, W M; Stollard, R J; Sampson, M; Lewis, J A

2002-12-01

A comprehensive sampling protocol was employed to evaluate the efficacy of Aqualox, a biocide based on electrochemically activated water, against legionellae and heterotrophic bacteria in two industrial cooling tower systems. Both of the towers in the study remained free from evidence of Legionella spp. contamination throughout a five-month evaluation period, despite the previously demonstrated presence of legionellae in one of the test towers, and in two other towers on the same site, at levels well in excess of UK Health and Safety Commission (HSC) Approved Code of Practice and Guidance (ACOP) upper action limits. Levels of heterotrophic bacteria were controlled below 10(4) cfu/mL in both towers throughout most of the trial. Results also provided indirect evidence of significant activity against biofilm bacteria, with biofilm removal beginning almost immediately after commissioning of the Aqualox treatment systems. The results were particularly encouraging as the two towers studied had a long history of poor microbiological control using conventional bromine-based biocide products. Significant differences were observed between laboratory measurements of total viable counts on frequent liquid samples and those obtained from dip slides following HSC recommendations. Copyright 2002 The Hospital Infection Society

Biocidal and Sporicidal Efficacy of Pathoster® 0.35% and Pathoster® 0.50% Against Bacterial Agents in Potential Bioterrorism Use

PubMed Central

Candeliere, Antonio; Donatiello, Adelia; Pagano, Stefania; Iatarola, Michela; Tolve, Francesco; Antonino, Leonardo; Fasanella, Antonio

2016-01-01

The use of products that can neutralize or significantly reduce the microbial load and that are not harmful to human health and the environment represents a milestone in the fight against the spread of infectious diseases. Peracetic acid, besides being an excellent sterilizing and sporicidal agent, is harmless to humans and the environment when it is used in a common dosage. However, the high costs and loss of efficacy of the product very quickly after its reconstitution limit its use. We evaluated the efficacy and stability of 2 commercial products, based on stabilized peracetic acid (Pathoster® 0.35% and Pathoster® 0.50%) used against spores of Bacillus anthracis and spores of Bacillus cereus and vegetative forms of Yersinia pestis, Burkholderia mallei, Burkholderia pseudomallei, Francisella tularensis, Brucella abortus, and Brucella melitensis. The efficacy tests were based on the direct contact of the products with a standard suspension of the bacteria. The stability of the products was defined as the period of time during which the biocidal and sporicidal properties remained unchanged. The limit of effectiveness was the period after which the product was unable to exert a complete sterilization after a contact of 5 minutes with at least 1 of the 8 bacteria used in this work. Both formulations showed good efficacy against the microorganisms used in the study, confirming the utility of peracetic acid as a sterilizing product. After the reconstitution, Pathoster® 0.35% was stable until 16±1 days, while Pathoster® 0.50% was stable until 24±1 days. The formulations used in this study showed good performance and a significant stability of peracetic acid. PMID:27482880

Biocidal and Sporicidal Efficacy of Pathoster(®) 0.35% and Pathoster(®) 0.50% Against Bacterial Agents in Potential Bioterrorism Use.

PubMed

Candeliere, Antonio; Campese, Emanuele; Donatiello, Adelia; Pagano, Stefania; Iatarola, Michela; Tolve, Francesco; Antonino, Leonardo; Fasanella, Antonio

2016-01-01

The use of products that can neutralize or significantly reduce the microbial load and that are not harmful to human health and the environment represents a milestone in the fight against the spread of infectious diseases. Peracetic acid, besides being an excellent sterilizing and sporicidal agent, is harmless to humans and the environment when it is used in a common dosage. However, the high costs and loss of efficacy of the product very quickly after its reconstitution limit its use. We evaluated the efficacy and stability of 2 commercial products, based on stabilized peracetic acid (Pathoster(®) 0.35% and Pathoster(®) 0.50%) used against spores of Bacillus anthracis and spores of Bacillus cereus and vegetative forms of Yersinia pestis, Burkholderia mallei, Burkholderia pseudomallei, Francisella tularensis, Brucella abortus, and Brucella melitensis. The efficacy tests were based on the direct contact of the products with a standard suspension of the bacteria. The stability of the products was defined as the period of time during which the biocidal and sporicidal properties remained unchanged. The limit of effectiveness was the period after which the product was unable to exert a complete sterilization after a contact of 5 minutes with at least 1 of the 8 bacteria used in this work. Both formulations showed good efficacy against the microorganisms used in the study, confirming the utility of peracetic acid as a sterilizing product. After the reconstitution, Pathoster(®) 0.35% was stable until 16±1 days, while Pathoster(®) 0.50% was stable until 24±1 days. The formulations used in this study showed good performance and a significant stability of peracetic acid.

Adaptation of amoebae to cooling tower biocides.

PubMed

Srikanth, S; Berk, S G

1994-05-01

Adaptation of amoebae to four cooling tower Biocides, which included a thiocarbamate compound, tributyltin neodecanoate mixed with quaternary ammonium compounds (TBT/QAC), another QAC alone, and an isothiazolin derivative, was studied. Previously we found that amoebae isolated from waters of cooling towers were more resistant to cooling tower biocides than amoebae from other habitats. Acanthamoeba hatchetti and Cochliopodium bilimbosum, obtained from American Type Culture Collection and used in the previous studies, were tested to determine whether they could adapt to cooling tower Biocides. A. hatchetti was preexposed to subinhibitory concentrations of the four Biocides for 72h, after which they were tested for their resistance to the same and other biocides. C. bilimbosum was exposed to only two biocides, as exposure to the other two was lethal after 72 h. Preexposure to the subinhibitory concentrations of the Biocides increased the resistance of the amoebae, as indicated by a significant increase in the minimum inhibitory concentration (up to 30-fold). In addition, cross-resistance was also observed, i.e., exposure to one biocide caused resistance to other biocides. These results show that amoebae can adapt to biocides in a short time. The phenomenon of cross-resistance indicates that regularly alternating biocides, as is done to control microbial growth in cooling towers, may not be effective in keeping amoeba populations in check. On the contrary, exposure to one biocide may boost the amoebae's resistance to a second biocide before the second biocide is used in the cooling tower. Since amoebae may harbor Legionella, or alone cause human diseases, these results may be important in designing effective strategies for controlling pathogens in cooling towers.

Green biocides, a promising technology: current and future applications to industry and industrial processes.

PubMed

Ashraf, Muhammad Aqeel; Ullah, Saleem; Ahmad, Irshad; Qureshi, Ahmad Kaleem; Balkhair, Khaled S; Abdur Rehman, Muhammad

2014-02-01

The study of biofilms has skyrocketed in recent years due to increased awareness of the pervasiveness and impact of biofilms. It costs the USA literally billions of dollars every year in energy losses, equipment damage, product contamination and medical infections. But biofilms also offer huge potential for cleaning up hazardous waste sites, filtering municipal and industrial water and wastewater, and forming biobarriers to protect soil and groundwater from contamination. The complexity of biofilm activity and behavior requires research contributions from many disciplines such as biochemistry, engineering, mathematics and microbiology. The aim of this review is to provide a comprehensive analysis of emerging novel antimicrobial techniques, including those using myriad organic and inorganic products as well as genetic engineering techniques, the use of coordination complex molecules, composite materials and antimicrobial peptides and the use of lasers as such or their modified use in combination treatments. This review also addresses advanced and recent modifications, including methodological changes, and biocide efficacy enhancing strategies. This review will provide future planners of biofilm control technologies with a broad understanding and perspective on the use of biocides in the field of green developments for a sustainable future. © 2013 Society of Chemical Industry.

Studies on the impact, detection, and control of microbiology influenced corrosion related to pitting failures in the Russian oil and gas industry. Final CRADA report.

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

Ehst, D.

2006-09-30

The objectives of the Project are: (1) to design effective anti-corrosion preparations (biocides, inhibitors, penetrants and their combinations) for gas- and oil-exploration industries; (2) to study a possibility of development of environmentally beneficial ('green') biocides and inhibitors of the new generation; (3) to develop chemical and microbiological methods of monitoring of sites at risk of corrosion; and (4) to evaluate potentialities in terms of technology, raw materials and material and technical basis to set up a production of effective anti-corrosion preparations of new generation in Russia. During the four years of the project 228 compounds and formulations were synthesized andmore » studied in respect to their corrosion inhibiting activity. A series of compounds which were according to the Bubble tests more efficient (by a factor of 10-100) than the reference inhibitor SXT-1102, some possessing the similar activity or slightly better activity than new inhibitor ??-1154? (company ONDEO/Nalco). Two synthetic routes for the synthesis of mercaptopyrimidines as perspective corrosion inhibitors were developed. Mercaptopyrimidine derivatives can be obtained in one or two steps from cheap and easily available precursors. The cost for their synthesis is not high and can be further reduced after the optimization of the production processes. A new approach for lignin utilization was proposed. Water-soluble derivative of lignin can by transformed to corrosion protective layer by its electropolymerization on a steel surface. Varying lignosulfonates from different sources, as well as conditions of electrooxidation we proved, that drop in current at high anodic potentials is due to electropolymerization of lignin derivative at steel electrode surface. The electropolymerization potential can be sufficiently decreased by an increase in ionic strength of the growing solution. The lignosulfonate electropolymerization led to the considerable corrosion protection effect of carbon steel. More than three times decrease of corrosion rate on steel surface was observed after lignosulfonate electropolymerization, exceeding protective effect of standard commercially available corrosion inhibitor. Solikamsky lignin could be a promising candidate as a base for the development of the future green corrosion inhibitor. A protective effect of isothiazolones in compositions with other biocides and inhibitors was investigated. Additionally to high biocidal properties, combination of kathon 893 and copper sulfate may also produce a strong anticorrosion effect depending on concentrations of the biocides. Based on its joint biocidal and anticorrosion properties, this combination can be recommended for protection of pipelines against carbon dioxide-induced corrosion. By means of linear polarization resistance test, corrosion properties of biocides of different classes were studied. Isothiazolones can be recommended for treating oil-processing waters in Tatarstan to curb carbon dioxide - induced corrosion. A laboratory research on evaluation of the efficiency of biocides, inhibitors and penetrants by biological and physical-and-chemical methods has been carried out. It was shown that action of corrosion inhibitors and biocides strongly depends on character of their interaction with mineral substances available in waters on oil-exploration sites. It was found that one of approaches to designing environmentally safe ('green') antimicrobial formulations may be the use of synergetic combinations, which allow one to significantly decrease concentrations of biocides. It was shown that the efficacy of biocides and inhibitors depends on physicochemical characteristics of the environment. Anticorrosion and antimicrobial effects of biocides and inhibitors depended in much on the type of medium and aeration regimen. Effects of different biocides, corrosion inhibitors. penetrants and their combinations on the biofilm were investigated. It has been shown that minimal inhibiting concentrations of the reagents for the biofilm are much higher than those for aquatic microorganisms. Results obtained from the research in stationary conditions have been confirmed with data from experiments carried out in hydrodynamic conditions. New approaches to the investigation of biocorrosive processes on the basis of bioluminescent method of intracellular ATP determination have been developed. Approaches and methods developed on the basis of bioluminescent method could significantly simplify the analysis of biocorrosion processes and allow to conduct the analysis directly under the field conditions in situ. An express method to assess biogenic sulfate reduction in soil and water samples has been elaborated. The method intends for field application and allows one to no-problem assess action of such harmful and corrosion provoking microorganisms, as sulfate-reducing bacteria.« less

Enhanced bioactivity of ZnO nanoparticles—an antimicrobial study

PubMed Central

Padmavathy, Nagarajan; Vijayaraghavan, Rajagopalan

2008-01-01

In this study, we investigate the antibacterial activity of ZnO nanoparticles with various particle sizes. ZnO was prepared by the base hydrolysis of zinc acetate in a 2-propanol medium and also by a precipitation method using Zn(NO3)2 and NaOH. The products were characterized by x-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. Bacteriological tests such as minimum inhibitory concentration (MIC) and disk diffusion were performed in Luria-Bertani and nutrient agar media on solid agar plates and in liquid broth systems using different concentrations of ZnO by a standard microbial method for the first time. Our bacteriological study showed the enhanced biocidal activity of ZnO nanoparticles compared with bulk ZnO in repeated experiments. This demonstrated that the bactericidal efficacy of ZnO nanoparticles increases with decreasing particle size. It is proposed that both the abrasiveness and the surface oxygen species of ZnO nanoparticles promote the biocidal properties of ZnO nanoparticles. PMID:27878001

Enhanced bioactivity of ZnO nanoparticles—an antimicrobial study

NASA Astrophysics Data System (ADS)

Padmavathy, Nagarajan; Vijayaraghavan, Rajagopalan

2008-07-01

In this study, we investigate the antibacterial activity of ZnO nanoparticles with various particle sizes. ZnO was prepared by the base hydrolysis of zinc acetate in a 2-propanol medium and also by a precipitation method using Zn(NO3)2 and NaOH. The products were characterized by x-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. Bacteriological tests such as minimum inhibitory concentration (MIC) and disk diffusion were performed in Luria-Bertani and nutrient agar media on solid agar plates and in liquid broth systems using different concentrations of ZnO by a standard microbial method for the first time. Our bacteriological study showed the enhanced biocidal activity of ZnO nanoparticles compared with bulk ZnO in repeated experiments. This demonstrated that the bactericidal efficacy of ZnO nanoparticles increases with decreasing particle size. It is proposed that both the abrasiveness and the surface oxygen species of ZnO nanoparticles promote the biocidal properties of ZnO nanoparticles.

Comparative Virucidal Efficacy of Seven Disinfectants Against Murine Norovirus and Feline Calicivirus, Surrogates of Human Norovirus.

PubMed

Zonta, William; Mauroy, Axel; Farnir, Frederic; Thiry, Etienne

2016-03-01

Human noroviruses (HuNoV) are the leading cause of acute non-bacterial gastroenteritis in humans and can be transmitted either by person-to-person contact or by consumption of contaminated food. A knowledge of an efficient disinfection for both hands and food-contact surfaces is helpful for the food sector and provides precious information for public health. The aim of this study was to evaluate the effect of seven disinfectants belonging to different groups of biocides (alcohol, halogen, oxidizing agents, quaternary ammonium compounds, aldehyde and biguanide) on infectious viral titre and on genomic copy number. Due to the absence of a cell culture system for HuNoV, two HuNoV surrogates, such as murine norovirus and feline calicivirus, were used and the tests were performed in suspension, on gloves and on stainless steel discs. When, as criteria of efficacy, a log reduction >3 of the infectious viral titre on both surrogates and in the three tests is used, the most efficacious disinfectants in this study appear to be biocidal products B, C and D, representing the halogens, the oxidizing agents group and a mix of QAC, alcohol and aldehyde, respectively. In addition, these three disinfectants also elicited a significant effect on genomic copy number for both surrogate viruses and in all three tests. The results of this study demonstrate that a halogen compound, oxidizing agents and a mix of QAC, alcohol and aldehyde are advisable for HuNoV disinfection of either potentially contaminated surfaces or materials in contact with foodstuffs.

Adsorption interactions of humic acids with biocides

NASA Astrophysics Data System (ADS)

Mal'Tseva, E. V.; Ivanov, A. A.; Yudina, N. V.

2009-11-01

The chemical composition of humic acids from brown coal (Aldrich) was determined by element analysis, 13C NMR spectroscopy, and potentiometric titration. The adsorption ability of humic acids with different biocides (cyproconasol, propiconasol, tebuconasol, irgarol 1051, and DCOIT) was studied. The adsorption ability of a mixture of biocides in aqueous solutions was higher than that of the individual components. The limiting concentration of humic acids at which adsorption of biocides was maximum was determined. Adsorption constants were calculated by the Freundlich equation for each biocide in aqueous solution.

Chemical Interactions of Hydraulic Fracturing Biocides with Natural Pyrite

NASA Astrophysics Data System (ADS)

Consolazio, Nizette A.

In conjunction with horizontal drilling, hydraulic fracturing or fracking has enabled the recovery of natural gas from low permeable shale formations. In addition to water, these fracking fluids employ proppants and up to 38 different chemical additives to improve the efficiency of the process. One important class of additives used in hydraulic fracturing is biocides. When applied appropriately, they limit the growth of harmful microorganisms within the well, saving energy producers 4.5 billion dollars each year. However, biocides or their harmful daughter products may return to the surface in produced water, which must then be appropriately stored, treated and disposed of. Little is known about the effect of mineral-fluid interactions on the fate of the biocides employed in hydraulic fracturing. In this study, we employed laboratory experiments to determine changes in the persistence and products of these biocides under controlled environments. While many minerals are present in shale formations, pyrite, FeS2(s) is particularly interesting because of its prevalence and reactivity. The FeII groups on the face of pyrite may be oxidized to form FeIII phases. Both of these surfaces have been shown to be reactive with organic compounds. Chlorinated compounds undergo redox reactions at the pyrite-fluid interface, and sulfur-containing compounds undergo exceptionally strong sorption to both pristine and oxidized pyrite. This mineral may significantly influence the degradation of biocides in the Marcellus Shale. Thus, the overall goal of this study was to understand the effect of pyrite on biocide reactivity in hydraulic fracturing, focusing on the influence of pyrite on specific functional groups. The first specific objective was to demonstrate the effect of pyrite and pyrite reaction products on the degradation of the bromine-containing biocide, DBNPA. On the addition of pyrite to DBNPA, degradation rates of the doubly brominated compound were found to increase significantly. DBNPA is proposed to undergo redox reactions with the pyrite surface, accepting two-electrons from pyrite, and thus becoming reduced. The primary product is the monobrominated analogue of DBNPA, 2-monobromo-3-nitrilopropionamide (or MBNPA). The surface area-normalized first-order initial degradation rate constant was found to be 5.1 L.m-2day-1. It was also determined that the dissolution and oxidation products of pyrite, Fe II, S2O32- and SO4 2- are unlikely to contribute to the reduction of the biocide. Taken together, the results illustrate that a surface reaction with pyrite has the ability to reduce the persistence of DBNPA, and as a consequence change the distribution of its reaction products. The second objective was to quantify the influence of water chemistry and interactions with pyrite on the degradation of the sulfur-containing biocide. Dazomet readily hydrolyzes in water due to the nucleophilic attack of hydroxide (OH-) anions. Thus the half-life of dazomet during the shut-in phase of hydraulic fracturing will decrease with increasing pH: 8.5 hours at pH 4.1 to 3.4 hours at pH 8.2.Dazomet degradation was rapidly accelerated upon exposure to the oxidized pyrite surface, reacting five times faster than hydrolysis in the absence of pyrite at a similar pH. The products measured were identical to those identified on hydrolysis (methyl isothiocyanate and formaldehyde) and no dissolved iron was detected in solutions. This suggests that the dithiocarbamate group in dazomet was able to chemisorb onto the oxidized pyrite surface, shifting the electron density of the molecule which resulted in accelerated hydrolysis of the biocide. The third objective explored the reactivity of various biocide functional groups due to the addition of pyrite. Several elimination mechanisms were identified, and tied to the reactivity of the specific functional group involved. The addition of pyrite led to accelerated degradation of dibromodicyanobutane. This is because the bromine (-Br) group is easily reduced. For methylene bis(thiocyanate), hydrolysis was a noteworthy elimination mechanism since the thiocyanate (-SCN) functionality is a good leaving group. Benzisothiazolinone and methyl isothiazolinone were stable at low pH due to the stabilizing donor-acceptor interactions between the organic biocides' carbonyl (-C=O) groups and salts in the solution. This body of work has illustrated that pristine pyrite can undergo redox reactions with brominated biocides used in hydraulic fracturing, reducing their persistence and altering the product distribution. This will change the efficacy and the risks associated with the use of these biocides in shales containing pyrite, particularly at lower pH where organic compounds are more stable to hydrolysis. However, at higher pH hydrolysis becomes more important, and additional studies will need to be conducted to investigate the pyrite contribution under these conditions. Conversely, the FeIII surface groups on oxidized pyrite can catalyze the hydrolysis of dazomet and may do so for other labile, sulfur-containing biocides as well. Overall, this research has shown that the physicochemical properties (such as the acid dissociation constant and the standard reduction potential) that govern the environmental reactivity of a molecule can be used to anticipate its reactivity in hydraulic fracturing.

Consumers' perceptions of biocidal products in households.

PubMed

Wieck, Stefanie; Olsson, Oliver; Kümmerer, Klaus

2018-03-01

Biocidal products are commonly used in households and can pose a risk to human health and the environment. The aim of this study was to evaluate consumers' use and understanding of biocidal products in order to identify starting points for minimising their exposure to these products and reducing possible emissions to the environment. In a case study, standardised questionnaires were used to interview consumers in 133 households in three neighbourhoods in Northern Germany, representing the urban-rural typologies in Europe: predominantly urban, intermediate and predominantly rural regions. The questions focussed on the comprehension of the term 'biocide', pest control habits, sources of information, risk perception of different product groups and possible emission reduction measures. Only 21% of the respondents understood the term 'biocide' correctly, whereas 29% thought of 'something that had to do with organic pest control', and 28% were not able to think of a possible meaning. The risk perception of biocidal products compared to plant protection products varied depending on the living conditions. In the urban neighbourhood, biocidal products were perceived as more dangerous than in the rural area. The main pests to be fought were ants, mould and fruit fly. The results of the study indicate that there is a considerable difference between the types of biocidal products that interviewees claimed to own and those that they actually did have in their households. Most notably, respondents did not realise that they owned surface disinfectants. This result indicates that consumers often seem not to be aware of using specific biocidal products. Also, this shows the limitations of collecting data on products owned with only one method, as the results from products inventories of the households deviate from the data collected in interviews. Our results show that the term 'biocide' is not fully understood by many people. To communicate possible risks of biocidal products, other terms would have to be used. Online information regarding general facts on necessary general hygiene measures and biocidal products against bacteria and insects are likely to be of highest relevance for consumers. However, risk communication for biocidal products in general is difficult because consumers are often not aware of using biocidal products. For this reason, information and awareness raising campaigns should be accompanied by further measures such as sales restrictions for specific user-groups or prohibitions of certain uses for a sustainable use of biocidal products. Copyright © 2017 Elsevier GmbH. All rights reserved.

Biocides in hydraulic fracturing: A comparison to agricultural and assessment of hazard and vulnerability with respect to groundwater pollution

NASA Astrophysics Data System (ADS)

Worrall, Fred; Wilson, Miles; Davies, Richard

2017-04-01

Biocides are one possible chemical additive to frack fluids and their role is to control bacterial growth. Since biocides are designed to be toxic to particular organisms, their accidental or deliberate release into the environment has become a growing topic of concern, especially with regards to fracking. The objective of this study was to consider whether biocides proposed for use in fracking, could be a threat to English groundwater based on past groundwater monitoring data. The study considered all groundwater samples analysed for biocides in English groundwater between 2005 and 2014. The monitoring records were compared to: records of application (both amount and area); and chemical and molecular data for the biocides. The study did not use traditional adsorption and degradation data as these parameters are prone to variability and are not pure molecular parameters. The study showed that of the 110 biocides tested for in English groundwaters in the decade 2005 - 2014. The total number of detections was 2234 out of 1475000 observations of 95 compounds, and 38 were compounds that were not applied during the period of record. The detection of these 38 compounds did not decline over the 10 year period implying very long residence times and that once compounds do pollute an aquifer, then they will be a persistent problem. The study was able to develop binomial regression models of the probability of detecting pesticide in groundwater based upon molecular and application variables; and solely upon molecular properties. The solubility of the range of biocides used in frack fluids would imply a potentially higher hazard than for most agricultural biocides, but molecular modelling implied that one compound could be safer than others.

Possible underestimations of risks for the environment due to unregulated emissions of biocides from households to wastewater.

PubMed

Wieck, Stefanie; Olsson, Oliver; Kümmerer, Klaus

2016-09-01

The aim of this study was to investigate the role of household products as possible sources of biocidal active substances in municipal wastewater and their regulation under the Biocidal Products Regulation (EU) 528/2012. In 131 households, we investigated the prevalence of products used to control pests, washing and cleaning agents and select personal care products with high release to wastewater. Inventories of these products were established with the help of barcode scanning. All uses of biocidal active substances were evaluated regarding their assessment under the Biocidal Products Regulation. 2963 products were scanned in total, with 48% being washing and cleaning agents, 43% personal care products and 9% products used to control pests. Biocidal active substances were found in each household. These were observed primarily in washing and cleaning agents and personal care products (90%), while only a small percentage of the observations of biocidal active substances was in biocidal products. 64% of the observations of biocidal active substances were in applications that do not fall under the Biocidal Products Regulation and are thus not subject to its environmental risk assessment. This study shows clearly that risks for the environment are underestimated because unregulated emissions to wastewater occur. It demonstrates that there are gaps in the current chemical legislation that lead to a release of substances into wastewater that were not subject to environmental risk assessment under the Biocidal Products Regulation. This is one example of the limitations of scientific risk assessment of chemicals - its complexity is immense. From our point of view, the results underline the importance of a sustainable use of the substances as this is the only way to decrease yet unidentified risks. Copyright © 2016 Elsevier Ltd. All rights reserved.

Resistance of Bacteria to Biocides.

PubMed

Maillard, Jean-Yves

2018-04-01

Biocides and formulated biocides are used worldwide for an increasing number of applications despite tightening regulations in Europe and in the United States. One concern is that such intense usage of biocides could lead to increased bacterial resistance to a product and cross-resistance to unrelated antimicrobials including chemotherapeutic antibiotics. Evidence to justify such a concern comes mostly from the use of health care-relevant bacterial isolates, although the number of studies of the resistance characteristics of veterinary isolates to biocides have increased the past few years. One problem remains the definition of "resistance" and how to measure resistance to a biocide. This has yet to be addressed globally, although the measurement of resistance is becoming more pressing, with regulators both in Europe and in the United States demanding that manufacturers provide evidence that their biocidal products will not impact on bacterial resistance. Alongside in vitro evidence of potential antimicrobial cross-resistance following biocide exposure, our understanding of the mechanisms of bacterial resistance and, more recently, our understanding of the effect of biocides to induce a mechanism(s) of resistance in bacteria has improved. This article aims to provide an understanding of the development of antimicrobial resistance in bacteria following a biocide exposure. The sections provide evidence of the occurrence of bacterial resistance and its mechanisms of action and debate how to measure bacterial resistance to biocides. Examples pertinent to the veterinary field are used where appropriate.

Effect of dry-ozone exposure on different polymer surfaces and their resulting biocidal action on sporulated bacteria

NASA Astrophysics Data System (ADS)

Mahfoudh, A.; Poncin-Épaillard, F.; Moisan, M.; Barbeau, J.

2010-08-01

The current work describes a novel technique by which certain types of polymers subjected to dry gaseous ozone acquire the ability to inactivate microorganisms, including those as resistant as bacterial spores. The originality and advantages of this ozone treatment of polymer surfaces rest on its simplicity (achieved at ambient temperature and pressure, a one step process …) and its efficacy. The inactivation efficiency is found to be specific to the nature of the treated polymer: 24 h after deposition of 10 6B. atrophaeus spores from a 100 µL suspension, high inactivation rates are observed with polymethyldisiloxane (99.997%, almost 5 log) and polystyrene (99.7%, more than 2 log), a lower rate with polyurethane (99.1%, 2 log) whereas polytetrafluoroethylene shows no detectable biocidal activity. Changes in hydrophilicity of these surfaces are monitored by means of contact-angle measurements while topographic modifications are characterized through atomic force microscopy. Ozone exposure brings about important topographic changes and chemical modifications on some polymers, which can be correlated with oxidation processes, increased wettability and surface energy. Variations of the dispersive and non-dispersive (polar) components of the surface energy are partially correlated with the polymer biocidal response. Furthermore, the basic component of the treated polymer (in contrast to its acidic component) seems to be correlated with the biocidal activity of the treated surfaces. Chemical species bearing ester groups, probably partially-oxidized styrene oligomers, as revealed by chemical analysis, could be involved in the biocidal activity. On practical grounds, since some of these treated polymers can strongly reduce microorganism loads on their surfaces, they could be particularly useful in hospital environment.

Continuous monitoring of bacterial attachment

NASA Technical Reports Server (NTRS)

Koeing, D. W.; Mishra, S. K.; Pierson, D. L.

1994-01-01

A major concern with the Space Station Freedom (SSF) water supply system is the control of longterm microbial contamination and biofilm development in the water storage and distribution systems. These biofilms have the potential for harboring pathogens as well as microbial strains containing resistance factors that could negatively influence crew health. The proposed means for disinfecting the water system on SSF (iodine) may encourage the selection of resistant strains. In fact, biofilm bacteria were observed in water lines from the Space Shuttle Columbia (OV-102); therefore, an alternative remediation method is required to disinfect spacecraft water lines. A thorough understanding of colonization events and the physiological parameters that will influence bacteria adhesion is required. The limiting factor for development of this technology is the ability to continuously monitor adhesion events and the effects of biocides on sessile bacteria. Methods were developed to allow bacterial adhesion and subsequent biocidal treatment to be monitored continuously. This technique couples automated image analysis with a continuous flow of a bacterial suspension through an optical flow cell. A strain of Pseudomonas cepacia isolated from the water supply of the Space Shuttle Discovery (OV-103) during STS-39 was grown in a nitrogen-limited continuous culture. This culture was challenged continuously with iodine during growth, and the adhesion characteristics of this strain was measure with regard to flow rate. Various biocides (ozone, hypochlorite, and iodine) were added to the flow stream to evaluate how well each chemical removed the bacteria. After biocide treatment, a fresh bacterial suspension was introduced into the flow cell, and the attachment rate was evaluated on the previously treated surface. This secondary fouling was again treated with biocide to determine the efficacy of multiple batch chemical treatments in removing biofilm.

Synergistic activity of biocides and antibiotics on resistant bacteria from organically produced foods.

PubMed

Fernández Fuentes, Miguel Angel; Abriouel, Hikmate; Gadea, Rebeca; Pérez Pulido, Rubén; Gálvez, Antonio; Ortega, Elena

2014-10-01

Synergism between biocides and antibiotics was investigated in 20 biocide and antibiotic-resistant bacterial strains that were previously isolated from organically produced foods, according to their antimicrobial resistance profiles. Most of the antibiotic/biocide combinations yielded synergistic interactions, reducing the inhibitory concentrations of biocides and antibiotics by 4- to 16-fold. Among enterococci, synergism with biocides was detected for amoxicillin (AM), cefuroxime (CX), erythromycin (EM), ciprofloxacin (CP), and trimethoprim/sulphametoxazol (T/S). Among staphylococci, interactions were synergistic (AM) and either synergistic or indifferent (CX and EM, depending on biocide). Among the three methicillin-resistant Staphylococcus aureus clinical strains included in the study, the combinations of methicillin and triclosan or hexachlorophene acted synergistically in all strains, but interactions were either synergistic or indifferent for the other biocides, depending on the strain. All combinations tested were synergistic for Lactobacillus (AM, CX, EM, and CP) and Micrococcus (AM, EM). In Salmonella, interactions were indifferent (AM, CX, EM, and CP) or synergistic (T/S). Synergism with biocides was also detected in Klebsiella isolates (AM, CX, and T/S), Enterobacter sp. (AM, CX, EM, and T/S), Pantoea (AM, CX, EM, CP, and T/S), and Chryseobacterium sp. (EM). These results suggest that combinations of biocides and antibiotics may open new possibilities to combat antimicrobial resistance.

Evaluation of Electrochemically Generated Potable Water Disinfectants for Use on the International Space Station

NASA Technical Reports Server (NTRS)

Vega, Leticia; Aber, Gregory; Adam, Niklas; Clements, Anna; Modica, Catherine; Younker, Diane

2011-01-01

Microbial contamination and subsequent growth in spacecraft water systems are constant concerns for missions involving human crews. The current potable water disinfectant is iodine; however, with the end of the Space Shuttle program, there is a need to develop redundant biocide systems which are less dependent on hardware that would need to be launched on a regular basis. Three systems for electrochemical production of potable water disinfectants are being assessed for use on the International Space Station (ISS). Since there is a wide variability in the literature with regards to efficacy in both concentration and exposure time of these disinfectants, there is a need to establish baseline efficacy values. This paper describes a series of tests performed in order to establish optimal concentrations and exposure times for four disinfectants against single and mixed species planktonic and biofilm bacteria and to determine whether these electrochemical disinfection devices are able to produce a sufficient amount of chemical in both concentration and volume to act as a biocide for potable water on ISS.

Resistance of Acanthamoeba Cysts to Disinfection Treatments Used in Health Care Settings▿

PubMed Central

Coulon, Céline; Collignon, Anne; McDonnell, Gerald; Thomas, Vincent

2010-01-01

Free-living amoebae that belong to the genus Acanthamoeba are widespread in the environment, including water. They are responsible for human infections and can host pathogenic microorganisms. Under unfavorable conditions, they form cysts with high levels of resistance to disinfection methods, thus potentially representing a threat to public health. In the present study we evaluated the efficacies of various biocides against trophozoites and cysts of several Acanthamoeba strains. We demonstrated that disinfectant efficacy varied depending on the strains tested, with environmental strains demonstrating greater resistance than collection strains. Trophozoites were inactivated by all treatments except those using glutaraldehyde as an active compound: for these treatments, we observed resistance even after 30 min exposure. Cysts resisted many treatments, including certain conditions with glutaraldehyde and other biocides. Moist heat at 55°C was not efficient against cysts, whereas exposure at 65°C was. Several chemical formulations containing peracetic acid, hydrogen peroxide, or ortho-phthalaldehyde presented greater efficacy than glutaraldehyde, as did ethanol and sodium hypochlorite; however, some of these treatments required relatively long incubation times to achieve cyst inactivation. Amoebal cysts can be highly resistant to some high-level disinfectants, which has implications for clinical practice. These results highlight the need to consider the effective disinfection of protozoa in their vegetative and resistant forms due to their intrinsic resistance. This is important not only to prevent the transmission of protozoa themselves but also due to the risks associated with a range of microbial pathogens that are found to be associated intracellularly with these microorganisms. PMID:20519477

Biocide Runoff from Building Facades: Degradation Kinetics in Soil.

PubMed

Bollmann, Ulla E; Fernández-Calviño, David; Brandt, Kristian K; Storgaard, Morten S; Sanderson, Hans; Bester, Kai

2017-04-04

Biocides are common additives in building materials. In-can and film preservatives in polymer-resin render and paint, as well as wood preservatives are used to protect facade materials from microbial spoilage. Biocides leach from the facade material with driving rain, leading to highly polluted runoff water (up to several mg L -1 biocides) being infiltrated into the soil surrounding houses. In the present study the degradation rates in soil of 11 biocides used for the protection of building materials were determined in laboratory microcosms. The results show that some biocides are degraded rapidly in soil (e.g., isothiazolinones: T 1/2 < 10 days) while others displayed higher persistence (e.g., terbutryn, triazoles: T 1/2 ≫ 120 days). In addition, mass balances of terbutryn and octylisothiazolinone were determined, including nine (terbutryn) and seven (octylisothiazolinone) degradation products, respectively. The terbutryn mass balance could be closed over the entire study period of 120 days and showed that relative persistent metabolites were formed, while the mass balances for octylisothiazolinone could not be closed. Octylisothiazolinone degradation products did not accumulate over time suggesting that the missing fraction was mineralized. Microtox-tests revealed that degradation products were less toxic toward the bacterium Aliivibrio fischeri than their parent compounds. Rain is mobilizing these biocides from the facades and transports them to the surrounding soils; thus, rainfall events control how often new input to the soil occurs. Time intervals between rainfall events in Northern Europe are shorter than degradation half-lives even for many rapidly degraded biocides. Consequently, residues of some biocides are likely to be continuously present due to repeated input and most biocides can be considered as "pseudo-persistent"-contaminants in this context. This was verified by (sub)urban soil screening, where concentrations of up to 0.1 μg g -1 were detected for parent compounds as well as terbutryn degradation products in soils below biocide treated facades.

A multiproxy approach to evaluate biocidal treatments on biodeteriorated majolica glazed tiles.

PubMed

Coutinho, M L; Miller, A Z; Martin-Sanchez, P M; Mirão, J; Gomez-Bolea, A; Machado-Moreira, B; Cerqueira-Alves, L; Jurado, V; Saiz-Jimenez, C; Lima, A; Phillips, A J L; Pina, F; Macedo, M F

2016-12-01

The Fishing House located on the grounds of the Marquis of Pombal Palace, Oeiras, Portugal, was built in the 18th century. During this epoch, Portuguese gardens, such as the one surrounding the Fishing House, were commonly ornamented with glazed wall tile claddings. Currently, some of these outdoor tile panels are covered with dark colored biofilms, contributing to undesirable aesthetic changes and eventually inducing chemical and physical damage to the tile surfaces. Phylogenetic analyses revealed that the investigated biofilms are mainly composed of green algae, cyanobacteria and dematiaceous fungi. With the aim of mitigating biodeterioration, four different biocides (TiO 2 nanoparticles, Biotin ® T, Preventol ® RI 80 and Albilex Biostat ® ) were applied in situ to the glazed wall tiles. Their efficacy was monitored by visual examination, epifluorescence microscopy and DNA-based analysis. Significant changes in the microbial community composition were observed 4 months after treatment with Preventol ® RI 80 and Biotin ® T. Although the original community was inactivated after these treatments, an early stage of re-colonization was detected 6 months after the biocide application. TiO 2 nanoparticles showed promising results due to their self-cleaning effect, causing the detachment of the biofilm from the tile surface, which remained clean 6 and even 24 months after biocide application. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Characterization of biocide-tolerant bacteria isolated from cheese and dairy small-medium enterprises.

PubMed

Fernández Márquez, Ma Luisa; Grande Burgos, Ma José; López Aguayo, Ma Carmen; Pérez Pulido, Rubén; Gálvez, Antonio; Lucas, Rosario

2017-04-01

A collection of 120 bacterial isolates from small medium enterprises involved in the production of cow milk and the manufacture of goat cheese were screened for sensitivity to biocides benzalkonium chloride (BC), cetrimide (CT), hexadecylpyridinium chloride (HDP), triclosan (TC), hexachlorophene (CF) and poly-(hexamethylen guanidinium) hydrochloride (PHMG). Nineteen isolates were selected according to biocide tolerance and identified by 16S rDNA sequencing as Lactococcus sp. (6) Enterococcus sp. (1), Lactobacillus sp. (4), Bacillus sp. (1) Escherichia sp. (5), Enterobacter sp. (1) and Helicobacter sp. (1). These were further characterised regarding antimicrobial resistance phenotype and genotype. Several isolates were multiply (3 or more) tolerant to biocides or resistant to antibiotics, but only two Escherichia sp. isolates and Enterobacter sp. were multiply resistant to biocides and antibiotics. Statistical analysis of biocide tolerance and antibiotic resistance revealed significant positive correlations between different biocides and between biocides and antibiotics. The biocide tolerance genes most frequently found were qacEΔ1 and qacA/B. The sulfonamide resistance gene sul1 was found in two Escherichia sp. isolates and in Enterobacter sp., all of which also carried qacEΔ1. Beta-lactam (bla CTX-M , bla PSE ) and tetracycline resistance genes [tet(A), tet(C) and tet(D)] were detected. Efflux pump genes acrB and mdfA were found in most Gram-negative isolates. Results from the study suggest that exposure to biocides can indirectly select for antibiotic resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.

Consumer exposure to biocides--identification of relevant sources and evaluation of possible health effects.

PubMed

Hahn, Stefan; Schneider, Klaus; Gartiser, Stefan; Heger, Wolfgang; Mangelsdorf, Inge

2010-02-03

Products containing biocides are used for a variety of purposes in the home environment. To assess potential health risks, data on products containing biocides were gathered by means of a market survey, exposures were estimated using a worst case scenario approach (screening), the hazard of the active components were evaluated, and a preliminary risk assessment was conducted. Information on biocide-containing products was collected by on-site research, by an internet inquiry as well as research into databases and lists of active substances. Twenty active substances were selected for detailed investigation. The products containing these substances were subsequently classified by range of application; typical concentrations were derived. Potential exposures were then estimated using a worst case scenario approach according to the European Commission's Technical Guidance Document on Risk Assessment. Relevant combinations of scenarios and active substances were identified. The toxicological data for these substances were compiled in substance dossiers. For estimating risks, the margins of exposure (MOEs) were determined. Numerous consumer products were found to contain biocides. However, it appeared that only a limited number of biocidal active substances or groups of biocidal active substances were being used. The lowest MOEs for dermal exposure or exposure by inhalation were obtained for the following scenarios and biocides: indoor pest control using sprays, stickers or evaporators (chlorpyrifos, dichlorvos) and spraying of disinfectants as well as cleaning of surfaces with concentrates (hydrogen peroxide, formaldehyde, glutardialdehyde). The risk from aggregate exposure to individual biocides via different exposure scenarios was higher than the highest single exposure on average by a factor of three. From the 20 biocides assessed 10 had skin-sensitizing properties. The biocides isothiazolinone (mixture of 5-chloro-2-methyl-2H-isothiazolin-3-one and 2-methyl-2H-isothiazolin-3-one, CMI/MI), glutardialdehyde, formaldehyde and chloroacetamide may be present in household products in concentrations which have induced sensitization in experimental studies. Exposure to biocides from household products may contribute to induction of sensitization in the population. The use of biocides in consumer products should be carefully evaluated. Detailed risk assessments will become available within the framework of the EU Biocides Directive.

Consumer exposure to biocides - identification of relevant sources and evaluation of possible health effects

PubMed Central

2010-01-01

Background Products containing biocides are used for a variety of purposes in the home environment. To assess potential health risks, data on products containing biocides were gathered by means of a market survey, exposures were estimated using a worst case scenario approach (screening), the hazard of the active components were evaluated, and a preliminary risk assessment was conducted. Methods Information on biocide-containing products was collected by on-site research, by an internet inquiry as well as research into databases and lists of active substances. Twenty active substances were selected for detailed investigation. The products containing these substances were subsequently classified by range of application; typical concentrations were derived. Potential exposures were then estimated using a worst case scenario approach according to the European Commission's Technical Guidance Document on Risk Assessment. Relevant combinations of scenarios and active substances were identified. The toxicological data for these substances were compiled in substance dossiers. For estimating risks, the margins of exposure (MOEs) were determined. Results Numerous consumer products were found to contain biocides. However, it appeared that only a limited number of biocidal active substances or groups of biocidal active substances were being used. The lowest MOEs for dermal exposure or exposure by inhalation were obtained for the following scenarios and biocides: indoor pest control using sprays, stickers or evaporators (chlorpyrifos, dichlorvos) and spraying of disinfectants as well as cleaning of surfaces with concentrates (hydrogen peroxide, formaldehyde, glutardialdehyde). The risk from aggregate exposure to individual biocides via different exposure scenarios was higher than the highest single exposure on average by a factor of three. From the 20 biocides assessed 10 had skin-sensitizing properties. The biocides isothiazolinone (mixture of 5-chloro-2-methyl-2H-isothiazolin-3-one and 2-methyl-2H-isothiazolin-3-one, CMI/MI), glutardialdehyde, formaldehyde and chloroacetamide may be present in household products in concentrations which have induced sensitization in experimental studies. Conclusions Exposure to biocides from household products may contribute to induction of sensitization in the population. The use of biocides in consumer products should be carefully evaluated. Detailed risk assessments will become available within the framework of the EU Biocides Directive. PMID:20128903

SOLUBILITY OF ORGANIC BIOCIDES IN SUPERCRITICAL CO2 AND CO2+ COSOLVENT MIXTURES

EPA Science Inventory

Solubilities of four organic biocides in supercritical carbon dioxide (Sc-CO2) were measured using a dynamic flowr apparatus over a pressure range of 10 to 30 MPa and temperature of 35-80 degrees C. The biocides studied were: Amical-48 (diiodomethyl p-tolyl sulfone), chlorothalo...

Decontamination Options for Bacillus anthracis-Contaminated Drinking Water Determined from Spore Surrogate Studies ▿

PubMed Central

Raber, Ellen; Burklund, Alison

2010-01-01

Five parameters were evaluated with surrogates of Bacillus anthracis spores to determine effective decontamination alternatives for use in a contaminated drinking water supply. The parameters were as follows: (i) type of Bacillus spore surrogate (B. thuringiensis or B. atrophaeus), (ii) spore concentration in suspension (102 and 106 spores/ml), (iii) chemical characteristics of the decontaminant (sodium dichloro-S-triazinetrione dihydrate [Dichlor], hydrogen peroxide, potassium peroxymonosulfate [Oxone], sodium hypochlorite, and VirkonS), (iv) decontaminant concentration (0.01% to 5%), and (v) exposure time to decontaminant (10 min to 1 h). Results from 138 suspension tests with appropriate controls are reported. Hydrogen peroxide at a concentration of 5% and Dichlor or sodium hypochlorite at a concentration of 2% were highly effective at spore inactivation regardless of spore type tested, spore exposure time, or spore concentration evaluated. This is the first reported study of Dichlor as an effective decontaminant for B. anthracis spore surrogates. Dichlor's desirable characteristics of high oxidation potential, high level of free chlorine, and a more neutral pH than that of other oxidizers evaluated appear to make it an excellent alternative. All three oxidizers were effective against B. atrophaeus spores in meeting the EPA biocide standard of greater than a 6-log kill after a 10-min exposure time and at lower concentrations than typically reported for biocide use. Solutions of 5% VirkonS and Oxone were less effective as decontaminants than other options evaluated in this study and did not meet the EPA's efficacy standard for a biocide, although they were found to be as effective for concentrations of 102 spores/ml. Differences in methods and procedures reported by other investigators make quantitative comparisons among studies difficult. PMID:20709855

Biocides in hydraulic fracturing: hazard and vulnerability with respect to potential groundwater pollution

NASA Astrophysics Data System (ADS)

Worrall, Fred; Wilson, Miles; Davies, Richard

2016-04-01

Biocides are one possible chemical additive to frack fluids and their role is to control bacterial growth. Bacterial growth might lead to biofilm build up; and acid sulfide species and hydrogen sulfide (H2S) production: biofilm build up may reduce formation permeability and hinder gas extraction. Kahrilas et al. (2014) published a review of common biocides used in fracking in the USA. The biocides assessed in the review were the sixteen most commonly used in the USA, based on the hydraulic fracturing chemical registry Frac Focus (Frac Focus, 2015). However, the review of Kahrilas et al. (2014) contained no data or observations and so the objective of this study was to consider whether biocides proposed for use in hydrofacturing could be a threat to English groundwater. The study considered all groundwater samples analysed for biocides in English groundwater between 2005 and 2014. The monitoring records were compared to: records of application (both amount and area); and chemical and molecular data for the biocides. The study did not use traditional adsorption and degradation data as these parameters are to prone to variability and are not pure molecular parameters. The study then used the approach of Worrall and Thomsen (2004) to consider the hazard represented by proposed frack biocides and the approach of Worrall and Kolpin (2003) to consider the vulnerability of the areas of potential shale gas exploitation. The study showed that of the 113 biocides tested for in English groundwaters in the decade 2005 - 2014 that 95 were detected above 0.1 g/l . Of these 95, 41 were compounds that were not recorded as being applied during the period of record and the detection of these 41 compounds did not decline over the 10 year period which implies very long residence times and that once compounds do pollute an aquifer then they will be a persistent problem. Furthermore, the solubility of the range of biocides used in frack fluids would imply a potentially higher hazard than for other compounds. For one proposed area of shale gas exploitation we could show that the for the 15 km radius around the proposed frack site the total average probability of detecting a pesticide above 0.1 μg l-1 was 0.08%, while for the same group of pesticides on the national scale, the probability of detection was 0.18%, i.e. for that area the aquifer was less vulnerable to biocide pollution than would be expected.

Adsorption and release of biocides with mesoporous silica nanoparticles

NASA Astrophysics Data System (ADS)

Popat, Amirali; Liu, Jian; Hu, Qiuhong; Kennedy, Michael; Peters, Brenton; Lu, Gao Qing (Max); Qiao, Shi Zhang

2012-01-01

In this proof-of-concept study, an agricultural biocide (imidacloprid) was effectively loaded into the mesoporous silica nanoparticles (MSNs) with different pore sizes, morphologies and mesoporous structures for termite control. This resulted in nanoparticles with a large surface area, tunable pore diameter and small particle size, which are ideal carriers for adsorption and controlled release of imidacloprid. The effect of pore size, surface area and mesoporous structure on uptake and release of imidacloprid was systematically studied. It was found that the adsorption amount and release profile of imidacloprid were dependent on the type of mesoporous structure and surface area of particles. Specifically, MCM-48 type mesoporous silica nanoparticles with a three dimensional (3D) open network structure and high surface area displayed the highest adsorption capacity compared to other types of silica nanoparticles. Release of imidacloprid from these nanoparticles was found to be controlled over 48 hours. Finally, in vivo laboratory testing on termite control proved the efficacy of these nanoparticles as delivery carriers for biopesticides. We believe that the present study will contribute to the design of more effective controlled and targeted delivery for other biomolecules.In this proof-of-concept study, an agricultural biocide (imidacloprid) was effectively loaded into the mesoporous silica nanoparticles (MSNs) with different pore sizes, morphologies and mesoporous structures for termite control. This resulted in nanoparticles with a large surface area, tunable pore diameter and small particle size, which are ideal carriers for adsorption and controlled release of imidacloprid. The effect of pore size, surface area and mesoporous structure on uptake and release of imidacloprid was systematically studied. It was found that the adsorption amount and release profile of imidacloprid were dependent on the type of mesoporous structure and surface area of particles. Specifically, MCM-48 type mesoporous silica nanoparticles with a three dimensional (3D) open network structure and high surface area displayed the highest adsorption capacity compared to other types of silica nanoparticles. Release of imidacloprid from these nanoparticles was found to be controlled over 48 hours. Finally, in vivo laboratory testing on termite control proved the efficacy of these nanoparticles as delivery carriers for biopesticides. We believe that the present study will contribute to the design of more effective controlled and targeted delivery for other biomolecules. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr11691j

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

PubMed

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

2013-05-15

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

Characterizing the microbial colonization of a dolostone quarry: implications for stone biodeterioration and response to biocide treatments.

PubMed

Cámara, Beatriz; De los Ríos, Asuncion; Urizal, Marta; de Buergo, Mónica Alvarez; Varas, Maria Jose; Fort, Rafael; Ascaso, Carmen

2011-08-01

This study examines the microbial colonization of three fronts of an abandoned dolostone quarry (Redueña, Madrid, Spain) exposed to atmospheric conditions for different time periods since Roman times to the present. Through scanning electron microscopy in backscattered electron mode (SEM-BSE), endolithic colonization was predominantly detected in the most recently exposed front, while in the longer exposed quarry fronts, epilithic forms of growth were most often observed. These observations were confirmed by denaturing gradient gel electrophoresis (DGGE) analysis. Based on the distribution pattern of microbial colonization in the different quarry fronts, we then established a sequence of colonization events that took place over this long time frame. Bioalteration processes related to this sequential colonization were also identified. Characterizing these sequential processes can be useful for interpreting biodeterioration processes in historic dolostone monuments, especially those affecting constructions in the area of the Redueña stone quarry. In a second experimental stage, different biocide treatments were tested on this quarry rock to find the best way to avoid the microbial colonization effects identified. Through combined SEM-BSE/DGGE analysis, the efficacy of several biocides against the microorganisms inhabiting the dolostones was assessed after 4 and 16 months treatment. In general, all treatments were effective at reducing around 80% of the lichen cover, although effects on endolithic lithobiontic communities were dependent on how well the rock surface had been mechanically cleaned prior to treatment and gradually disappeared over time.

Comparative toxicological effects of two antifouling biocides on the marine diatom Chaetoceros lorenzianus: Damage and post-exposure recovery.

PubMed

Chavan, Pooja; Kumar, Rajesh; Kirubagaran, Ramalingam; Venugopalan, Vayalam P

2017-10-01

Antifouling biocides are commonly used in coastal electric power stations to prevent biofouling in their condenser cooling systems. However, the environmental impact of the chemical biocides is less understood than the thermal stress effects caused by the condenser effluents. In this study, Chaetoceros lorenzianus, a representative marine diatom, was used to analyse the toxicity of two antifouling biocides, chlorine and chlorine dioxide. The diatom cells were subjected to a range of concentrations of the biocides (from 0.05 to 2mg/L, as total residual oxidants, TRO) for contact time of 30min. They were analysed for viability, genotoxicity, chlorophyll a and cell density endpoints. The cells were affected at all concentrations of the biocides (0.05-2mg/L), showing dose-dependent decrease in viability and increase in DNA damage. The treated cells were later incubated in filtered seawater devoid of biocide to check for recovery. The cells were able to recover in terms of overall viability and DNA damage, when they had been initially treated with low concentrations of the biocides (0.5mg/L of Cl 2 or 0.2mg/L of ClO 2 ). Chlorophyll a analysis showed irreparable damage at all concentrations, while cell density showed increasing trend of reduction, if treated above 0.5mg/L of Cl 2 and 0.2mg/L of ClO 2 . The data indicated that in C. lorenzianus, cumulative toxic effects and recovery potential of ClO 2 up to 0.2mg/L were comparable with those of Cl 2 , up to 0.5mg/L concentration in terms of the studied endpoints. The results indicate that at the biocide levels currently being used at power stations, recovery of the organism is feasible upon return to ambient environment. Similar studies should be carried out on other planktonic and benthic organisms, which will be helpful in the formulation of future guidelines for discharge of upcoming antifouling biocides such as chlorine dioxide. Copyright © 2017 Elsevier Inc. All rights reserved.

Alternatives to petroleum-based biocides for protecting hardwood lumber and manufactured products. Transferring technologies for industry No. 4. Final report

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

Murdoch, C.W.

1993-03-30

The report addresses the current and prospective mechanisms for developing environmentally responsible treatments for wood products that prevent stain, decay, and insect damage. The author examines various aspects of the problem and current prevention techniques, including an extended discussion of the attributes and shortcomings of six treatments reviewed by the Animal and Plant Health Inspection Service, US Department of Agriculture, in An Efficacy Review of Control Measures for Potential Pests of Imported Soviet Timber. The portion of the report labeled Uncommercialized Technologies presents the new, uncommercialized technologies discovered through this project. They include: guayule shrub-derived wood preservative; biological control strategies;more » tannins derived from tree bark; insect-specific toxins from arthropod and vertebrate venoms; and natural biocidal repellents.« less

Aspects of cooling tower biocides and protozoa

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

Berk, S.G.; Ashburn, R.J.; Ting, R.S.

1998-12-31

Previous work has shown that certain cooling tower amoebae and ciliated protozoa are resistant to several cooling tower biocides, even at the manufacturer`s recommended dosages. For the present study, an Acunthumoeba species was isolated from a cooling tower in Australia. Suspensions of the trophozoites (feeding stages) were exposed to isothiazolones. Cysts were tested separately. The minimum lethal concentration (MLC) for trophozoites was between 31-62 ppm of the biocide product, which is slightly less than the MLC for an amoebae species from the United States; and cyst forms were twofold more resistant than those of the US species, with a MLCmore » of 62,500 ppm. A ciliate and an amoeba species were also exposed to bromochlorodimethylhydantoin. The MLC for the ciliate species was 1 ppm of the biocide product, and the MLC was 30--40 ppm for the amoeba trophozoites. Since amoebae can expel vesicles containing live Legionella, experiments were conducted to determine whether exposure of Acunthamoebu polyphugu to biocides influenced release of such potentially infectious particles. Vesicle release was not inhibited by any of the three biocides: quaternary ammonium compounds (QACs), isothiazolones, and a thiocarbamate compound. These results suggest that amoebae from various sources are resistant to recommended levels of biocides, and the amoebae may continue to release potentially infectious vesicles in the presence of biocides.« less

Inactivation of Bacillus anthracis Spores by a Combination of Biocides and Heating under High-Temperature Short-Time Pasteurization Conditions ▿

PubMed Central

Xu, Sa; Labuza, Theodore P.; Diez-Gonzalez, Francisco

2008-01-01

The milk supply is considered a primary route for a bioterrorism attack with Bacillus anthracis spores because typical high-temperature short-time (HTST) pasteurization conditions cannot inactivate spores. In the event of intentional contamination, an effective method to inactivate the spores in milk under HTST processing conditions is needed. This study was undertaken to identify combinations and concentrations of biocides that can inactivate B. anthracis spores at temperatures in the HTST range in less than 1 min. Hydrogen peroxide (HP), sodium hypochlorite (SH), and peroxyacetic acid (PA) were evaluated for their efficacy in inactivating spores of strains 7702, ANR-1, and 9131 in milk at 72, 80, and 85°C using a sealed capillary tube technique. Strains ANR-1 and 9131 were more resistant to all of the biocide treatments than strain 7702. Addition of 1,260 ppm SH to milk reduced the number of viable spores of each strain by 6 log CFU/ml in less than 90 and 60 s at 72 and 80°C, respectively. After neutralization, 1,260 ppm SH reduced the time necessary to inactivate 6 log CFU/ml (TTI6-log) at 80°C to less than 20 s. Treatment of milk with 7,000 ppm HP resulted in a similar level of inactivation in 60 s. Combined treatment with 1,260 ppm SH and 1,800 ppm HP inactivated spores of all strains in less than 20 s at 80°C. Mixing 15 ppm PA with milk containing 1,260 ppm SH resulted in TTI6-log of 25 and 12 s at 72 and 80°C, respectively. TTI6-log of less than 20 s were also achieved at 80°C by using two combinations of biocides: 250 ppm SH, 700 ppm HP, and 150 ppm PA; and 420 ppm SH (pH 7), 1,100 ppm HP, and 15 ppm PA. These results indicated that different combinations of biocides could consistently result in 6-log reductions in the number of B. anthracis spores in less than 1 min at temperatures in the HTST range. This information could be useful for developing more effective thermal treatment strategies which could be used in HTST milk plants to process contaminated milk for disposal and decontamination, as well as for potential protective measures. PMID:18390680

Inactivation of Bacillus anthracis spores by a combination of biocides and heating under high-temperature short-time pasteurization conditions.

PubMed

Xu, Sa; Labuza, Theodore P; Diez-Gonzalez, Francisco

2008-06-01

The milk supply is considered a primary route for a bioterrorism attack with Bacillus anthracis spores because typical high-temperature short-time (HTST) pasteurization conditions cannot inactivate spores. In the event of intentional contamination, an effective method to inactivate the spores in milk under HTST processing conditions is needed. This study was undertaken to identify combinations and concentrations of biocides that can inactivate B. anthracis spores at temperatures in the HTST range in less than 1 min. Hydrogen peroxide (HP), sodium hypochlorite (SH), and peroxyacetic acid (PA) were evaluated for their efficacy in inactivating spores of strains 7702, ANR-1, and 9131 in milk at 72, 80, and 85 degrees C using a sealed capillary tube technique. Strains ANR-1 and 9131 were more resistant to all of the biocide treatments than strain 7702. Addition of 1,260 ppm SH to milk reduced the number of viable spores of each strain by 6 log CFU/ml in less than 90 and 60 s at 72 and 80 degrees C, respectively. After neutralization, 1,260 ppm SH reduced the time necessary to inactivate 6 log CFU/ml (TTI6-log) at 80 degrees C to less than 20 s. Treatment of milk with 7,000 ppm HP resulted in a similar level of inactivation in 60 s. Combined treatment with 1,260 ppm SH and 1,800 ppm HP inactivated spores of all strains in less than 20 s at 80 degrees C. Mixing 15 ppm PA with milk containing 1,260 ppm SH resulted in TTI6-log of 25 and 12 s at 72 and 80 degrees C, respectively. TTI6-log of less than 20 s were also achieved at 80 degrees C by using two combinations of biocides: 250 ppm SH, 700 ppm HP, and 150 ppm PA; and 420 ppm SH (pH 7), 1,100 ppm HP, and 15 ppm PA. These results indicated that different combinations of biocides could consistently result in 6-log reductions in the number of B. anthracis spores in less than 1 min at temperatures in the HTST range. This information could be useful for developing more effective thermal treatment strategies which could be used in HTST milk plants to process contaminated milk for disposal and decontamination, as well as for potential protective measures.

Ecotoxicological Assessment of Immersion Samples from Façade Render Containing Free or Encapsulated Biocides.

PubMed

Vermeirssen, Etiënne L M; Campiche, Sophie; Dietschweiler, Conrad; Werner, Inge; Burkhardt, Michael

2018-05-22

To protect house façades from fouling by microorganisms, biocides can be added to a render or paint before it is applied. During driving rain events, these biocides gradually leach out and have the potential to pollute soil or aquatic ecosystems. We studied the leaching behaviour of biocides and toxicity of leachates from renders with either free or encapsulated biocides. Both render types contained equal amounts of terbutryn, 2-octyl-3(2H)-isothiazolinone (OIT) and 4,5-dichloro-2-n-octyl-4-isothiazolino-3-one (DCOIT). Leachate samples were generated over nine immersion cycles according to a European standard and biocides were quantified. The first and ninth samples were tested using bioassays with algae, bacteria and water flea, the first sample with earthworms and springtails. Encapsulation reduced leaching of terbutryn, OIT and DCOIT four-, 17-, and 27-fold. For aquatic organisms, the toxicity of water from render containing encapsulated biocides was always lower than that of render with free biocides. Furthermore, toxicity decreased four- to five-fold over the nine immersion cycles. Inhibition of photosynthesis was the most sensitive endpoint, followed by algal growth rate, bacterial bioluminescence and water flea reproduction. Toxicity to algae was explained by terbutryn and toxicity to bacteria by OIT. None of the samples affected soil organisms. Results demonstrate that combining standardised leaching tests with standardised bioassays is a promising approach to evaluate the ecotoxicity of biocides that leach from façade renders. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

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

PubMed

Pagedar, Ankita; Singh, Jitender

2015-08-01

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

Lung cancer mortality and exposure to synthetic metalworking fluid and biocides: controlling for the healthy worker survivor effect.

PubMed

Garcia, Erika; Picciotto, Sally; Neophytou, Andreas M; Bradshaw, Patrick T; Balmes, John R; Eisen, Ellen A

2018-05-09

Synthetic metalworking fluids (MWFs), widely used to cool and lubricate industrial machining and grinding operations, have been linked with increased risk of several cancers. Estimates of their relation with lung cancer, however, are inconsistent. Controlling for the healthy worker survivor effect, we examined the relations between lung cancer mortality and exposure to synthetic MWF, as well as to biocides added to water-based fluids to control microbial growth, in a cohort of autoworkers. Biocides served as a marker for endotoxin, which has reported antitumour effects, and were hypothesised to be the reason prior studies found reduced lung cancer risk associated with exposure to synthetic fluids. Using the parametric g-formula, we estimated risk ratios (RRs) comparing cumulative lung cancer mortality under no intervention with what would have occurred under hypothetical interventions reducing exposure to zero (ie, a ban) separately for two exposures: synthetic fluids and biocides. We also specified an intervention on synthetic MWF and biocides simultaneously to estimate joint effects. Under a synthetic MWF ban, we observed decreased lung cancer mortality risk at age 86, RR=0.96 (0.91-1.01), but when we also intervened to ban biocides, the RR increased to 1.03 (0.95-1.11). A biocide-only ban increased lung cancer mortality (RR=1.07 (1.00-1.16)), with slightly larger RR in younger ages. Findings suggest a modest positive association for synthetic MWF with lung cancer mortality, contrary to the negative associations reported in earlier studies. Biocide exposure, however, was inversely associated with risk of lung cancer mortality. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Selection of an Alternate Biocide for the ISS Internal Thermal Control System Coolant, Phase 2

NASA Technical Reports Server (NTRS)

Wilson, Mark E.; Cole, Harold; Weir, Natalee; Oehler, Bill; Steele, John; Varsik, Jerry; Lukens, Clark

2004-01-01

The ISS (International Space Station) ITCS (Internal Thermal Control System) includes two internal coolant loops that utilize an aqueous based coolant for heat transfer. A silver salt biocide had previously been utilized as an additive in the coolant formulation to control the growth and proliferation of microorganisms within the coolant loops. Ground-based and in-flight testing demonstrated that the silver salt was rapidly depleted, and did not act as an effective long-term biocide. Efforts to select an optimal alternate biocide for the ITCS coolant application have been underway and are now in the final stages. An extensive evaluation of biocides was conducted to down-select to several candidates for test trials and was reported on previously. Criteria for that down-select included: the need for safe, non-intrusive implementation and operation in a functioning system; the ability to control existing planktonic and biofilm residing microorganisms; a negligible impact on system-wetted materials of construction; and a negligible reactivity with existing coolant additives. Candidate testing to provide data for the selection of an optimal alternate biocide is now in the final stages. That testing has included rapid biocide effectiveness screening using Biolog MT2 plates to determine minimum inhibitory concentration (amount that will inhibit visible growth of microorganisms), time kill studies to determine the exposure time required to completely eliminate organism growth, materials compatibility exposure evaluations, coolant compatibility studies, and bench-top simulated coolant testing. This paper reports the current status of the effort to select an alternate biocide for the ISS ITCS coolant. The results of various test results to select the optimal candidate are presented.

Comprehensive Evaluation of Biological Growth Control by Chlorine-Based Biocides in Power Plant Cooling Systems Using Tertiary Effluent

PubMed Central

Chien, Shih-Hsiang; Dzombak, David A.; Vidic, Radisav D.

2013-01-01

Abstract Recent studies have shown that treated municipal wastewater can be a reliable cooling water alternative to fresh water. However, elevated nutrient concentration and microbial population in wastewater lead to aggressive biological proliferation in the cooling system. Three chlorine-based biocides were evaluated for the control of biological growth in cooling systems using tertiary treated wastewater as makeup, based on their biocidal efficiency and cost-effectiveness. Optimal chemical regimens for achieving successful biological growth control were elucidated based on batch-, bench-, and pilot-scale experiments. Biocide usage and biological activity in planktonic and sessile phases were carefully monitored to understand biological growth potential and biocidal efficiency of the three disinfectants in this particular environment. Water parameters, such as temperature, cycles of concentration, and ammonia concentration in recirculating water, critically affected the biocide performance in recirculating cooling systems. Bench-scale recirculating tests were shown to adequately predict the biocide residual required for a pilot-scale cooling system. Optimal residuals needed for proper biological growth control were 1, 2–3, and 0.5–1 mg/L as Cl2 for NaOCl, preformed NH2Cl, and ClO2, respectively. Pilot-scale tests also revealed that Legionella pneumophila was absent from these cooling systems when using the disinfectants evaluated in this study. Cost analysis showed that NaOCl is the most cost-effective for controlling biological growth in power plant recirculating cooling systems using tertiary-treated wastewater as makeup. PMID:23781129

Comprehensive Evaluation of Biological Growth Control by Chlorine-Based Biocides in Power Plant Cooling Systems Using Tertiary Effluent.

PubMed

Chien, Shih-Hsiang; Dzombak, David A; Vidic, Radisav D

2013-06-01

Recent studies have shown that treated municipal wastewater can be a reliable cooling water alternative to fresh water. However, elevated nutrient concentration and microbial population in wastewater lead to aggressive biological proliferation in the cooling system. Three chlorine-based biocides were evaluated for the control of biological growth in cooling systems using tertiary treated wastewater as makeup, based on their biocidal efficiency and cost-effectiveness. Optimal chemical regimens for achieving successful biological growth control were elucidated based on batch-, bench-, and pilot-scale experiments. Biocide usage and biological activity in planktonic and sessile phases were carefully monitored to understand biological growth potential and biocidal efficiency of the three disinfectants in this particular environment. Water parameters, such as temperature, cycles of concentration, and ammonia concentration in recirculating water, critically affected the biocide performance in recirculating cooling systems. Bench-scale recirculating tests were shown to adequately predict the biocide residual required for a pilot-scale cooling system. Optimal residuals needed for proper biological growth control were 1, 2-3, and 0.5-1 mg/L as Cl 2 for NaOCl, preformed NH 2 Cl, and ClO 2 , respectively. Pilot-scale tests also revealed that Legionella pneumophila was absent from these cooling systems when using the disinfectants evaluated in this study. Cost analysis showed that NaOCl is the most cost-effective for controlling biological growth in power plant recirculating cooling systems using tertiary-treated wastewater as makeup.

Effects of Antifouling Biocides on Molecular and Biochemical Defense System in the Gill of the Pacific Oyster Crassostrea gigas.

PubMed

Park, Mi Seon; Kim, Young Dae; Kim, Bo-Mi; Kim, Youn-Jung; Kim, Jang Kyun; Rhee, Jae-Sung

2016-01-01

Antifouling biocides such as organotin compounds and their alternatives are potent toxicants in marine ecosystems. In this study, we employed several molecular and biochemical response systems of the Pacific oyster Crassostrea gigas to understand a potential mode of action of antifouling biocides (i.e. tributyltin (TBT), diuron and irgarol) after exposure to different concentrations (0.01, 0.1, and 1 μg L-1) for 96 h. As a result, all the three antifouling biocides strongly induced the antioxidant defense system. TBT reduced both enzymatic activity and mRNA expression of Na+/K+-ATPase and acetylcholinesterase (AChE). Lower levels of both Na+/K+-ATPase activity and AChE mRNA expression were observed in the diuron-exposed oysters compared to the control, while the irgarol treatment reduced only the transcriptional expression of AChE gene. We also analyzed transcript profile of heat shock protein (Hsp) superfamily in same experimental conditions. All antifouling biocides tested in this study significantly modulated mRNA expression of Hsp superfamily with strong induction of Hsp70 family. Taken together, overall results indicate that representative organotin TBT and alternatives have potential hazardous effects on the gill of C. gigas within relatively short time period. Our results also suggest that analyzing a series of molecular and biochemical parameters can be a way of understanding and uncovering the mode of action of emerging antifouling biocides. In particular, it was revealed that Pacific oysters have different sensitivities depend on the antifouling biocides.

Biocidal properties of maltose reduced silver nanoparticles against American foulbrood diseases pathogens.

PubMed

Çulha, Mustafa; Kalay, Şaban; Sevim, Elif; Pinarbaş, Müberra; Baş, Yıldız; Akpinar, Rahşan; Karaoğlu, Şengül Alpay

2017-12-01

Bee disease caused by spore-forming Paenibacillus larvae and Paenibacillus alvei is a serious problem for honey production. Thus, there is an ongoing effort to find an effective agent that shows broad biocidal activity with minimal environmental hazard. In this study, the biocidal effect of maltose reduced silver nanoparticles (AgNPs) is evaluated against American foulbrood and European foulbrood pathogens. The results demonstrate that the maltose reduced AgNPs are excellent short and long-term biocides against P. larvae isolates. The long-term effect suggests that the Ag + ions are released from the AgNPs with increasing time in a controlled manner.

Modeling of facade leaching in urban catchments

NASA Astrophysics Data System (ADS)

Coutu, S.; Del Giudice, D.; Rossi, L.; Barry, D. A.

2012-12-01

Building facades are protected from microbial attack by incorporation of biocides within them. Flow over facades leaches these biocides and transports them to the urban environment. A parsimonious water quantity/quality model applicable for engineered urban watersheds was developed to compute biocide release from facades and their transport at the urban basin scale. The model couples two lumped submodels applicable at the basin scale, and a local model of biocide leaching at the facade scale. For the facade leaching, an existing model applicable at the individual wall scale was utilized. The two lumped models describe urban hydrodynamics and leachate transport. The integrated model allows prediction of biocide concentrations in urban rivers. It was applied to a 15 km2urban hydrosystem in western Switzerland, the Vuachère river basin, to study three facade biocides (terbutryn, carbendazim, diuron). The water quality simulated by the model matched well most of the pollutographs at the outlet of the Vuachère watershed. The model was then used to estimate possible ecotoxicological impacts of facade leachates. To this end, exceedance probabilities and cumulative pollutant loads from the catchment were estimated. Results showed that the considered biocides rarely exceeded the relevant predicted no-effect concentrations for the riverine system. Despite the heterogeneities and complexity of (engineered) urban catchments, the model application demonstrated that a computationally "light" model can be employed to simulate the hydrograph and pollutograph response within them. It thus allows catchment-scale assessment of the potential ecotoxicological impact of biocides on receiving waters.

Considerations on Directive 98/8 of the European Commission - the biocide directive.

PubMed

Patryn, Rafał; Jarosz, Mirosław J; Włoszczak-Szubzda, Anna; Sak, Jarosław; Pawlikowski, Jakub

2011-01-01

Nowadays, versatile human activity requires the development of technologies in the chemical and biological industries that ultimately enable an increase in human activity, and help create the living conditions in the domain of human civilization. Increasing this activity very frequently requires the implementation of new technologies concerning the active elimination of numerous threats and obstacles which are found in the human and natural environment. The concept of so-called biocidal products has been introduced into the European legislation as long as ten years ago, defining them as various types of 'chemical substances or microorganisms which can deter, render harmless, or exert a controlling eff ect on any harmful organism, by chemical or biological means'. They can be added to other materials (typically liquids) to protect them against biological infestation and growth. Biocidal products - due to their specificity, toxicity and composition - create a serious risk for human and animal life and health, as well as for the natural environment, it is therefore fully justified to have legal regulations concerning such biocides. Because biocidal products are intended to kill living organisms, and as such, many biocidal products pose a significant risk to human health and welfare, and have significant adverse eff ects on the natural environment. Great care is required when handling biocides and appropriate protective clothing and equipment should be used. Currently, Directive 98/8/EC is a comprehensive set of legal regulations concerning biocidal products, their specificity, principles relating to their placing on the market, and guidelines for their control. It is worth emphasizing that Directive 98/8/EC implements the clampdown on poisoning cases with biocides, the duty of which was passed to the so-called Centres of Consultation and Toxicological Information. These centres provide round-the-clock (24-hour) medical consultation and assistance in cases of poisonings with these products. The presented study constitutes an in-depth presentation and analysis of the European law concerning biocides and the current regulations applying to them.

Modelling biofilm-induced formation damage and biocide treatment in subsurface geosystems

PubMed Central

Ezeuko, C C; Sen, A; Gates, I D

2013-01-01

Biofilm growth in subsurface porous media, and its treatment with biocides (antimicrobial agents), involves a complex interaction of biogeochemical processes which provide non-trivial mathematical modelling challenges. Although there are literature reports of mathematical models to evaluate biofilm tolerance to biocides, none of these models have investigated biocide treatment of biofilms growing in interconnected porous media with flow. In this paper, we present a numerical investigation using a pore network model of biofilm growth, formation damage and biocide treatment. The model includes three phases (aqueous, adsorbed biofilm, and solid matrix), a single growth-limiting nutrient and a single biocide dissolved in the water. Biofilm is assumed to contain a single species of microbe, in which each cell can be a viable persister, a viable non-persister, or non-viable (dead). Persisters describe small subpopulation of cells which are tolerant to biocide treatment. Biofilm tolerance to biocide treatment is regulated by persister cells and includes ‘innate’ and ‘biocide-induced’ factors. Simulations demonstrate that biofilm tolerance to biocides can increase with biofilm maturity, and that biocide treatment alone does not reverse biofilm-induced formation damage. Also, a successful application of biological permeability conformance treatment involving geologic layers with flow communication is more complicated than simply engineering the attachment of biofilm-forming cells at desired sites. PMID:23164434

Aspects of tests and assessment of filtering materials used for respiratory protection against bioaerosols. Part I: type of active substance, contact time, microorganism species.

PubMed

Majchrzycka, Katarzyna; Gutarowska, Beata; Brochocka, Agnieszka

2010-01-01

This paper presents the results of a study on antimicrobial activity of polymer filter nonwovens produced by needle-punching or melt-blowing with an addition of disinfecting agents. The first part of the paper discusses how the biocidal activity of nonwovens is a function of the active agent added to the nonwovens, the duration of the contact of microorganisms with nonwovens and the type of microorganisms. The types of fibres and disinfecting agents had a considerable effect on the biocidal activity of nonwovens. The biocidal effect of nonwovens increased with the duration of their contact with microorganisms. Fibre activity differed considerably depending on the species of the microorganism. The microorganisms most sensitive to biocidal activity of the active filter nonwoven were S. aureus, M. flavus and E. coli. There were no biocidal effects on spore-forming bacterium B. subtilis.

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

PubMed Central

Nardello-Rataj, Véronique

2014-01-01

Summary Host–guest chemistry is useful for the construction of nanosized objects. Some of the widely used hosts are probably the cyclodextrins (CDs). CDs can form water-soluble complexes with numerous hydrophobic compounds. They have been widespread used in medicine, drug delivery and are of interest for the biocides encapsulation. Indeed, this enables the development of more or less complex systems that release antimicrobial agents with time. In this paper, the general features of CDs and their applications in the field of biocides have been reviewed. As the key point is the formation of biocide–CD inclusion complexes, this review deals with this in depth and the advantages of biocide encapsulation are highlighted throughout several examples from the literature. Finally, some future directions of investigation have been proposed. We hope that scientists studying biocide applications receive inspiration from this review to exploit the opportunities offered by CDs in their respective research areas. PMID:25550722

Availability and Efficacy of Ballast Water Treatment Technology: Background and Issue Paper

DTIC Science & Technology

2010-06-01

transiting the Great Lakes- implications for HAB invasions. Harmful Algae , 6, 519-530. Dobroski, N., Scianni, C., Gehringer, D., & Falkner M.. 2009a. 2009...538. Drake, L., Doblin, M., & Dobbs, F. 2007. Potential microbial bioinvasions via ships’ ballast water, sediment, and biofilm . Marine Pollution...water biocides against vegetative microalgae, dinoflagellate cysts and bacteria. Harmful Algae , 6, 567-584. Gregg. M., Rigby, G., & Hallegraeff

Loading and release mechanisms of a biocide in polystyrene-block-poly(acrylic acid) block copolymer micelles.

PubMed

Vyhnalkova, Renata; Eisenberg, Adi; van de Ven, Theo G M

2008-07-24

The kinetics of loading of polystyrene197-block-poly(acrylic acid)47 (PS197-b-PAA47) micelles, suspended in water, with thiocyanomethylthiobenzothiazole biocide and its subsequent release were investigated. Loading of the micelles was found to be a two-step process. First, the surface of the PS core of the micelles is saturated with biocide, with a rate determined by the transfer of solid biocide to micelles during transient micelle-biocide contacts. Next, the biocide penetrates as a front into the micelles, lowering the Tg in the process (non-Fickian case II diffusion). The slow rate of release is governed by the height of the energy barrier that a biocide molecule must overcome to pass from PS into water, resulting in a uniform biocide concentration within the micelle, until Tg is increased to the point that diffusion inside the micelles becomes very slow. Maximum loading of biocide into micelles is approximately 30% (w/w) and is achieved in 1 h. From partition experiments, it can be concluded that the biocide has a similar preference for polystyrene as for ethylbenzene over water, implying that the maximum loading is governed by thermodynamics.

Effects of Antifouling Biocides on Molecular and Biochemical Defense System in the Gill of the Pacific Oyster Crassostrea gigas

PubMed Central

Park, Mi Seon; Kim, Young Dae; Kim, Bo-Mi; Kim, Youn-Jung; Kim, Jang Kyun; Rhee, Jae-Sung

2016-01-01

Antifouling biocides such as organotin compounds and their alternatives are potent toxicants in marine ecosystems. In this study, we employed several molecular and biochemical response systems of the Pacific oyster Crassostrea gigas to understand a potential mode of action of antifouling biocides (i.e. tributyltin (TBT), diuron and irgarol) after exposure to different concentrations (0.01, 0.1, and 1 μg L-1) for 96 h. As a result, all the three antifouling biocides strongly induced the antioxidant defense system. TBT reduced both enzymatic activity and mRNA expression of Na+/K+-ATPase and acetylcholinesterase (AChE). Lower levels of both Na+/K+-ATPase activity and AChE mRNA expression were observed in the diuron-exposed oysters compared to the control, while the irgarol treatment reduced only the transcriptional expression of AChE gene. We also analyzed transcript profile of heat shock protein (Hsp) superfamily in same experimental conditions. All antifouling biocides tested in this study significantly modulated mRNA expression of Hsp superfamily with strong induction of Hsp70 family. Taken together, overall results indicate that representative organotin TBT and alternatives have potential hazardous effects on the gill of C. gigas within relatively short time period. Our results also suggest that analyzing a series of molecular and biochemical parameters can be a way of understanding and uncovering the mode of action of emerging antifouling biocides. In particular, it was revealed that Pacific oysters have different sensitivities depend on the antifouling biocides. PMID:28006823

New environmentally-benign concepts in wood protection: the combination of organic biocides and non-biocidal additives

Treesearch

Frederick Green; Tor P. Schultz

2003-01-01

The principal wood preservative for residential use is currently a broad-spectrum biocide which contains As, Cr and Cu. However, the use of totally organic wood preservative systems in certain applications or localities may be required in the future. This will greatly increase the price of treated wood. The combination of organic biocides with non-biocidal additives to...

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

PubMed

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

2015-10-01

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

The environmental fate and effects of antifouling paint biocides.

PubMed

Thomas, K V; Brooks, S

2010-01-01

Antifouling (AF) biocides are the active ingredients in AF paints that prevent the settlement, adhesion and growth of organisms to a painted surface. A wide range of chemicals are used as AF biocides, which have very different physico-chemical properties and therefore differing environmental fates, behaviour and effects. Copper has been used as an antifoulant for centuries and extensive research has been performed to understand how copper speciation influences bioavailability and toxicity. For biocides that have been widely used over a number of decades, for example Irgarol 1051 and diuron, there are a large amount of environmental data in the public domain, including for their respective metabolites, that allows their environmental safety and potential risk to the environment to be assessed. For other biocides such as dichlofluanid, DCOIT (SeaNine 211) and zinc/copper pyrithione, there is a good understanding of their fate and effects. However, few monitoring studies have been performed and not so much is known about the fate and effects of their metabolites. There are also new or candidate biocides such as triphenylborane pyridine, Econea, capsaicin and medetomidine for which there is very little information in the public domain. This review provides an overview of the environmental fate and occurrence data that are in the public domain for AF biocides and provides some insight into the effects of these compounds on non-target organisms.

Biocidal Efficacy of a Flocculating Emergency Water Purification Tablet

DTIC Science & Technology

1994-07-01

size filters (Millipore, Bedford, Mass.). A 2-g waters were challenged with 107 Giardia muris cysts per liter portion of the recovered floc was...of Giardia muris cyst inactivation by lower microbial counts. Although CF tablets will remove some 1chlorine. Appl. Environ. Microbiol. 5O-1 15-1117...removed poliovirus type I from water at low temperatures genie dye as measures of Giardia muris cyst inactivation by ozone. even at high pH

Suitability of small environmental chambers to test the emission of biocides from treated materials into the air

NASA Astrophysics Data System (ADS)

Horn, Wolfgang; Jann, Oliver; Wilke, Olaf

Biocides are used to protect materials that might be damaged by fungal, microbial or insect activity. The aim of this study is to develop a method for the measurement of these organic compounds, which generally have low or moderate vapor pressures. The biocides considered in this study are permethrin, dichlofluanid, tolylfluanid, iodpropinylbutylcarbamat, octylisothiazolinone, tebuconazole and propiconazole. The emission from two commercial products (plastic foil, wool carpet) containing biocides and of seven types of biocidal formulations applied to wood or clay tiles were investigated in 20-l glass emission test chambers. Each chamber test was performed over a period of 100-200 days, and one investigation was conducted over several years. Compared to volatile organic compounds, low-volatility compounds show totally different emission curves in chamber tests; maximal emission values may be reached in days or weeks. A period of 3 months is sometimes necessary for the determination of area-specific emission rates (SER a's). The SER a's (μg m -2 h -1) from biocide-containing products were determined for permethrin (0.006), propiconazole (0.3), dichlofluanid (2.0), tolylfluanid (1.0), octylisothiazolinone (2.5) and iodpropinylbutylcarbamat (2). In most cases, the SER a stayed at its maximum value or declined slowly over the test period. Additionally, a chamber test begun in 1994 with a piece of wood treated with a typical mixture of biocides dissolved in a technical solvent was continued. SER a's (μg m -2 h -1) for dichlofluanid (0.20), tebuconazole (0.49) and permethrin (0.08) remained detectable after the period of nearly 9 years during which the sample remained continuously in the chamber. This test proved the very slow decrease of emission of low-volatility compounds like permethrin and tebuconazole.

Adverse Effect of Antifouling Compounds on the Reproductive Mechanisms of the Ascidian Ciona intestinalis

PubMed Central

Gallo, Alessandra; Tosti, Elisabetta

2013-01-01

Fertilization and embryo development that occur in sea water are sensitive to xenobiotics from anthropogenic sources. In this work, we evaluated the influence of two antifouling biocides, tributyltin (TBT) and diuron, on the reproductive mechanisms of the marine invertebrate Ciona intestinalis. By using electrophysiological techniques, we examined the impact of these compounds on the electrical properties of the mature oocytes and of events occurring at fertilization. With different toxicity assays, we studied the effect of the two biocides on the gametes by evaluating fertilization rate and embryo development. Results show that sodium (Na+) currents were significantly reduced by either of the two biocides, whereas conductance was significantly increased. The fertilization current frequency and amplitude, fertilization rate and larval development were affected only by TBT. This study suggests that: (i) the two biocides affect either the electrical properties of the oocyte plasma membrane and the reproductive success representing a risk factor for the survival of the species exposed to environmental pollution; (ii) the ascidian Ciona intestinalis may represent a good model organism to test toxicity of marine pollutants. Possible mechanisms of action of the two biocides are discussed. PMID:24065165

Antibody engineering--a valuable asset in preventing closed environment epidemics.

PubMed

Fjallman, Ted; Hall, J Christopher

2005-01-01

Investigations of Mir, Space Shuttle, Skylab and Apollo missions report extensive colonisation of the spacecraft by bacteria and fungi, which can lead to degradative effects on spacecraft equipment and devastating effects on space-grown crops. More than 80% of terrestrial greenhouse epidemics are due to the fungal genera Phytophthora, Pythium and Fusarium, which have been found in life support system test-beds. The advent of recombinant antibody technologies, including ribosome display and phage display, has made it possible to develop antibodies against virtually any toxin or organism and allows for maturation of antibodies by in vitro molecular evolution. These antibodies may play an important role in an integrated pest management regime for life support systems. Efficacy of existing fungal countermeasures could be increased by chemical linkage to antibodies, which target the site of action of the biocide or trap the pathogen in a biofilter. Novel recombinant antibody-biocide fusions can be expressed in situ by plants or symbiotic microbes to create direct disease resistance. c2005 Elsevier Ltd. All rights reserved.

Decay model for biocide treatment of unballasted vessels: application for the Laurentian Great Lakes.

PubMed

Sano, Larissa L; Bartell, Steven M; Landrum, Peter F

2005-10-01

A biocide decay model was developed to assess the potential efficacy and environmental impacts associated with using glutaraldehyde to treat unballasted overseas vessels trading on the Laurentian Great Lakes. The results of Monte Carlo simulations indicate that effective glutaraldehyde concentrations can be maintained for the duration of a vessel's oceanic transit (approximately 9-12 days): During this transit, glutaraldehyde concentrations were predicted to decrease by approximately 10% from initial treatment levels (e.g., 500 mgL(-1)). In terms of environmental impacts, mean glutaraldehyde concentrations released at Duluth-Superior Harbor, MN were predicted to be 100-fold lower than initial treatment concentrations, and ranged from 3.2 mgL(-1) (2 SD: 2.74) in April to 0.7 mgL(-1) (2 SD: 1.28) in August. Sensitivity analyses indicated that the re-ballasting dilution factor was the major variable governing final glutaraldehyde concentrations; however, lake surface temperatures became increasingly important during the warmer summer months.

Chapter 14: Evaluating the Leaching of Biocides from Preservative-Treated Wood Products

Treesearch

Stan T. Lebow

2014-01-01

Leaching of biocides is an important consideration in the long term durability and any potential for environmental impact of treated wood products. This chapter discusses factors affecting biocide leaching, as well as methods of evaluating rate and quantity of biocide released. The extent of leaching is a function of preservative formulation, treatment methods, wood...

Protecting wood from mould, decay, and termites with multi-component biocide systems

Treesearch

Carol A. Clausen

2007-01-01

Biocides must be developed for controlling mould establishment on cellulose-based building materials. Accordingly, biocides intended for indoor applications must be non- toxic, non-volatile, odourless, hypoallergenic, and able to provide long-term protection under conditions of high humidity. Multi-component biocide systems were tested in American Wood-Preservers’...

Biofilms and Oxidizing Biocides; Evaluation of Disinfection and Removal Effects by Using Established Microbial Systems.

PubMed

Tachikawa, Mariko

2017-01-01

The formation of bacterial biofilms and their disinfection and removal have been important subjects in the maintenance of water quality in areas such as public spas, swimming pools, food processing lines, industrial water systems, and in the hygienic control of medical devices, hospital procedures, etc. Presented here is an outline of biofilm formation, as well as studies on the disinfection and removal of biofilms by oxidizing biocides using established biofilms. These studies using established biofilms may increase the understanding of the variable response of biofilms to planktonic bacteria, and the unique aspects of oxidizing biocides in the disinfection and removal of biofilms.

Comparative evaluation of the activity of commercial biocides in relation to micromycetes

NASA Astrophysics Data System (ADS)

Strokova, Valeria; Nelyubova, Victoria; Vasilenko, Marina; Goncharova, Elena; Rykunova, Marina; Kalatozi, Elina

2017-11-01

The paper presents the results of comparative studies of commercial biocides of Russian production, used in the technology of biostable materials for construction purposes, to micromycetes of various species and type diversity. The influence of the type of biocide additive on their fungicidal activity was established. The fungicidal effect of bioactive agents was evaluated using a disc-diffusion method. The analysis of the results is carried out both using the traditional approach and a modified method using a scoring of the degree of impact.

Biocide and antibiotic resistance of Enterococcus faecalis and Enterococcus faecium isolated from the swine meat chain.

PubMed

Rizzotti, Lucia; Rossi, Franca; Torriani, Sandra

2016-12-01

In this study nine strains of Enterococcus faecalis and 12 strains of Enterococcus faecium, isolated from different sample types in the swine meat chain and previously characterized for the presence of antibiotic resistance genes, were examined for phenotypic tolerance to seven biocides (chlorexidine, benzalkonium chloride, triclosan, sodium hypochlorite, 2-propanol, formaldehyde and hydrogen peroxide) and resistance to nine antibiotics (ampicillin, vancomycin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline and chloramphenicol). Moreover, the presence of efflux system encoding genes qacA/B, qacC, qacE, qacEΔ1, emeA, and stress response genes, sigV and gsp65, involved in the tolerance to biocides, was analysed. Most strains were not tolerant to the biocides, but showed minimum inhibitory concentrations (MICs) higher than the recommended cut-off values for all the antibiotics tested, except for vancomycin and chloramphenicol. Only weak correlations, if any, were found between biocide and antibiotic resistance data. One E. faecalis strain was tolerant to triclosan and one E. faecium strain, with higher tolerance to chlorexidine than the other strains tested, was found to carry a qacA/B gene. Our results indicated that phenotypic resistance to antibiotics is very frequent in enterococcal isolates from the swine meat chain, but phenotypic tolerance to biocides is not common. On the other hand, the gene qacA/B was found for the first time in the species E. faecium, an indication of the necessity to adopt measures suitable to control the spread of biocide resistance determinants among enterococci. Copyright © 2016 Elsevier Ltd. All rights reserved.

Material Testing in Support of the ISS Electrochemical Disinfection Feasibility Study

NASA Technical Reports Server (NTRS)

Clements, Anna; Shindo, David; Modica, Cathy

2011-01-01

The International Space Station Program recognizes the risk of microbial contamination in their potable and non-potable water sources. With the end of the Space Shuttle Program, the ability to send up shock-kits of biocides in the event of an outbreak becomes even more difficult. Currently, the US Segment water system relies primarily on iodine to mitigate contamination concerns. To date, several small cases of contamination have occurred which have been remediated. NASA, however, realizes that having a secondary method of combating a microbial outbreak is a prudent investment. NASA is looking into developing hardware that can generate biocides electrochemically, and potentially deploying that hardware. The specific biocides that the technology could generate include: hydrogen peroxide, oxone, hypochlorite and peracetic acid. In order to use these biocides on deployed water systems, the project must determine that all the materials in the potential application are compatible with the biocides at their anticipated administered concentrations. This paper will detail the materials test portion of the feasibility assessment including the plan for both metals and non-metals along with results to date.

Compatibility Study of Silver Biocide in Drinking Water with Candidate Metals for Crew Exploration Vehicle Potable Water System

NASA Technical Reports Server (NTRS)

Adam, Niklas M.

2009-01-01

The stability of silver biocide, used to keep drinking water on the CEV potable water sterile, is unknown as the system design is still in progress. Silver biocide in water can deplete rapidly when exposed to various metal surfaces. Additionally, silver depletion rates may be affected by the surface-area-to-volume (SA/V) ratios in the water system. Therefore, to facilitate the CEV water system design, it would be advantageous to know the biocide depletion rates in water exposed to the surfaces of these candidate metals at various SA/V ratios. Certain surface treatments can be employed to reduce the depletion rates of silver compared to the base metal. The purpose of this work is to determine the compatibility of specific spaceflight-certified metals that could used in the design of the CEV potable water system with silver biocide as well as understand the effect of surface are to volume ratios of metals used in the construction of the potable water system on the silver concentration.

Risks of Using Antifouling Biocides in Aquaculture

PubMed Central

Guardiola, Francisco Antonio; Cuesta, Alberto; Meseguer, José; Esteban, Maria Angeles

2012-01-01

Biocides are chemical substances that can deter or kill the microorganisms responsible for biofouling. The rapid expansion of the aquaculture industry is having a significant impact on the marine ecosystems. As the industry expands, it requires the use of more drugs, disinfectants and antifoulant compounds (biocides) to eliminate the microorganisms in the aquaculture facilities. The use of biocides in the aquatic environment, however, has proved to be harmful as it has toxic effects on the marine environment. Organic booster biocides were recently introduced as alternatives to the organotin compounds found in antifouling products after restrictions were imposed on the use of tributyltin (TBT). The replacement products are generally based on copper metal oxides and organic biocides. The biocides that are most commonly used in antifouling paints include chlorothalonil, dichlofluanid, DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, Sea-nine 211®), Diuron, Irgarol 1051, TCMS pyridine (2,3,3,6-tetrachloro-4-methylsulfonyl pyridine), zinc pyrithione and Zineb. There are two types of risks associated with the use of biocides in aquaculture: (i) predators and humans may ingest the fish and shellfish that have accumulated in these contaminants and (ii) the development of antibiotic resistance in bacteria. This paper provides an overview of the effects of antifouling (AF) biocides on aquatic organisms. It also provides some insights into the effects and risks of these compounds on non-target organisms. PMID:22408407

Risks of using antifouling biocides in aquaculture.

PubMed

Guardiola, Francisco Antonio; Cuesta, Alberto; Meseguer, José; Esteban, Maria Angeles

2012-01-01

Biocides are chemical substances that can deter or kill the microorganisms responsible for biofouling. The rapid expansion of the aquaculture industry is having a significant impact on the marine ecosystems. As the industry expands, it requires the use of more drugs, disinfectants and antifoulant compounds (biocides) to eliminate the microorganisms in the aquaculture facilities. The use of biocides in the aquatic environment, however, has proved to be harmful as it has toxic effects on the marine environment. Organic booster biocides were recently introduced as alternatives to the organotin compounds found in antifouling products after restrictions were imposed on the use of tributyltin (TBT). The replacement products are generally based on copper metal oxides and organic biocides. The biocides that are most commonly used in antifouling paints include chlorothalonil, dichlofluanid, DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, Sea-nine 211(®)), Diuron, Irgarol 1051, TCMS pyridine (2,3,3,6-tetrachloro-4-methylsulfonyl pyridine), zinc pyrithione and Zineb. There are two types of risks associated with the use of biocides in aquaculture: (i) predators and humans may ingest the fish and shellfish that have accumulated in these contaminants and (ii) the development of antibiotic resistance in bacteria. This paper provides an overview of the effects of antifouling (AF) biocides on aquatic organisms. It also provides some insights into the effects and risks of these compounds on non-target organisms.

Biocidal additives for lubricating/cooling fluids

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

Morozova, L.P.; Klyavlina, E.A.; Lebedev, E.V.

1984-03-01

This article reports on the synthesis of new biocidal products for the protection of water emulsions of lubricating/cooling fluids (LCFs) against microbiological damage. The new biocides are based on compounds belonging to the classes of oxazolidines and oxazines, and also compounds of these classes but activated by nitro derivatives of aromatic hydrocarbons. Results are presented from evaluations of the biocidal activity of the new products with respect to aerobes, anaerobes, and fungi growing in a 3% emulsion of the widely used LCF Ukrinol-1. The comparative evaluation was based on the optimal biocidal concentration corresponding to the smallest quantity of addedmore » biocide to give maximum suppression of the microorganisms in a minimum time, and with the longest period of effectiveness. The lubricating properties of the biocides were evaluated in an emulsion of the Ukrinol-1 LCF is a four-ball tester. It is concluded that the developed biocides are homogeneous, transparent liquids with a specific odor and can be considered as nontoxic to man; they mix readily with components used in formulating LCFs and detergents (sulfonates, oxyethylated alcohols, phenols, polyglycols, fatty acid soaps, etc.). They are readily soluble in water and in oils. Includes 3 tables.« less

A novel anti-influenza copper oxide containing respiratory face mask.

PubMed

Borkow, Gadi; Zhou, Steve S; Page, Tom; Gabbay, Jeffrey

2010-06-25

Protective respiratory face masks protect the nose and mouth of the wearer from vapor drops carrying viruses or other infectious pathogens. However, incorrect use and disposal may actually increase the risk of pathogen transmission, rather than reduce it, especially when masks are used by non-professionals such as the lay public. Copper oxide displays potent antiviral properties. A platform technology has been developed that permanently introduces copper oxide into polymeric materials, conferring them with potent biocidal properties. We demonstrate that impregnation of copper oxide into respiratory protective face masks endows them with potent biocidal properties in addition to their inherent filtration properties. Both control and copper oxide impregnated masks filtered above 99.85% of aerosolized viruses when challenged with 5.66+/-0.51 and 6.17+/-0.37 log(10)TCID(50) of human influenza A virus (H1N1) and avian influenza virus (H9N2), respectively, under simulated breathing conditions (28.3 L/min). Importantly, no infectious human influenza A viral titers were recovered from the copper oxide containing masks within 30 minutes (< or = 0.88 log(10)TCID(50)), while 4.67+/-1.35 log(10)TCID(50) were recovered from the control masks. Similarly, the infectious avian influenza titers recovered from the copper oxide containing masks were < or = 0.97+/-0.01 log(10)TCID(50) and from the control masks 5.03+/-0.54 log(10)TCID(50). The copper oxide containing masks successfully passed Bacterial Filtration Efficacy, Differential Pressure, Latex Particle Challenge, and Resistance to Penetration by Synthetic Blood tests designed to test the filtration properties of face masks in accordance with the European EN 14683:2005 and NIOSH N95 standards. Impregnation of copper oxide into respiratory protective face masks endows them with potent anti-influenza biocidal properties without altering their physical barrier properties. The use of biocidal masks may significantly reduce the risk of hand or environmental contamination, and thereby subsequent infection, due to improper handling and disposal of the masks.

Biocides in the Yangtze River of China: spatiotemporal distribution, mass load and risk assessment.

PubMed

Liu, Wang-Rong; Zhao, Jian-Liang; Liu, You-Sheng; Chen, Zhi-Feng; Yang, Yuan-Yuan; Zhang, Qian-Qian; Ying, Guang-Guo

2015-05-01

Nineteen biocides were investigated in the Yangtze River to understand their spatiotemporal distribution, mass loads and ecological risks. Fourteen biocides were detected, with the highest concentrations up to 166 ng/L for DEET in surface water, and 54.3 ng/g dry weight (dw) for triclocarban in sediment. The dominant biocides were DEET and methylparaben, with their detection frequencies of 100% in both phases. An estimate of 152 t/y of 14 biocides was carried by the Yangtze River to the East China Sea. The distribution of biocides in the aquatic environments was significantly correlated to Gross Domestic Product (GDP), total phosphorus (TP) and total nitrogen (TN), suggesting dominant input sources from domestic wastewater of the cities along the river. Risk assessment showed high ecological risks posed by carbendazim in both phases and by triclosan in sediment. Therefore, proper measures should be taken to reduce the input of biocides into the river systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effective delivery of volatile biocides employing mesoporous silicates for treating biofilms

PubMed Central

Chan, Andrea C.; Townley, Helen E.

2017-01-01

Nanoparticulate delivery of biocides has the potential to decrease levels of exposure to non-target organisms, and miminize long-term exposure that can promote the development of resistance. Silica nanoparticles are an ideal vehicle since they are inert, biocompatible, biodegradable, and thermally and chemically stable. Encapsulation of biocides within nanoparticulates can improve their stability and longevity and maximize the biocidal potential of hydrophobic volatile compounds. Herein, we have shown that the plant secondary metabolites allyl isothiocyanate and cinnamaldehyde demonstrated increased antimicrobial activity against Escherichia coli in planktonic form, when packaged into mesoporous silica nanoparticles. Furthermore, the biocide-loaded nanoparticles showed activity against Pseudomonas aeruginosa biofilms that have inherent resistance to antimicrobial agents. The delivery platform can also be expanded to traditional biocides and other non-conventional antimicrobial agents. PMID:28077760

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

PubMed

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

2006-07-01

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

Ecotoxicological potential of the biocides terbutryn, octhilinone and methylisothiazolinone: Underestimated risk from biocidal pathways?

PubMed

Kresmann, Simon; Arokia, Arokia Hansel Rajan; Koch, Christoph; Sures, Bernd

2018-06-01

The use of biocides by industry, agriculture and households increased throughout the last two decades. Many new applications with known substances enriched the variety of biocidal pollution sources for the aquatic environment. While agriculture was the major source for a long time, leaching from building facades and preservation of personal care and cleaning products was identified as new sources in the last few years. With the different usage forms of biocidal products the complexity of legislative regulation increased as well. The requirements for risk assessment differ from one law to another and the potential risk of substances under different regulations might be underestimated. Still EC 50 and predicted no-effect concentration (PNEC) values gained from testing with different species are the core of environmental risk assessment, but ecotoxicological data is limited or lacking for many biocides. In this study the biocides widely used in facade coatings and household products terbutryn, octhilinone and methylisothiazolinone were tested with the Daphnia magna acute immobilisation assay, the neutral red uptake assay and the ethoxyresorufin-O-deethylase (EROD) assay, performed with rainbow trout liver (RTL-W1) cells. Further, the MTT assay with the ovarian cell line CHO-9 from Chinese hamster was used as mammalian model. Octhilinone induced the strongest effects with EC 50 values of 156μg/l in the D. magna assay, while terbutryn showed the weakest effects with 8390μg/l and methylisothiazolinone 513μg/l respectively. All other assays showed higher EC 50 values and thus only weak effects. EROD assays did not show any effects. With additional literature and database records PNEC values were calculated: terbutryn reached 0.003μg/l, octhilinone 0.05μg/l and methylisothiazolinone 0.5μg/l. Potential ecotoxicological risks of these biocides are discussed, considering environmental concentrations. Copyright © 2017 Elsevier B.V. All rights reserved.

40 CFR 430.17 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides...

40 CFR 430.47 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides...

40 CFR 430.17 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides...

40 CFR 430.67 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides...

40 CFR 430.67 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides...

Antimicrobial activity of a new intact skin antisepsis formulation.

PubMed

Russo, Antonello; Viotti, Pier Luigi; Vitali, Matteo; Clementi, Massimo

2003-04-01

Different antiseptic formulations have shown limitations when applied to disinfecting intact skin, notably short-term tolerability and/or efficacy. The purpose of this study was optimizing a new antiseptic formulation specifically targeted at intact skin disinfection and evaluating its in vitro microbicidal activity and in vivo efficacy. The biocidal properties of the antiseptic solution containing 0.5% chloramine-T diluted in 50% isopropyl alcohol (Cloral; Eurospital SpA Trieste, Italy) were measured in vitro versus gram-positive-, gram-negative-, and acid-alcohol-resistant germs and fungi with standard suspension tests in the presence of fetal bovine serum. Virus-inhibiting activity was evaluated in vitro against human cytomegalovirus, herpes simplex virus, poliovirus, hepatitis B virus, and hepatitis C virus. Tests used different methods for the different biologic and in vitro replication capacity of these human viruses. Lastly, Cloral tolerability and skin colonization retardation efficacy after disinfection were studied in vivo. The antiseptic under review showed fast and sustained antimicrobial activity. The efficacy of Cloral against clinically important bacterial and viral pathogens and fungi was highlighted under the experimental conditions described in this article. Finally, microbial regrowth lag and no side effects were documented in vivo after disinfection of 11 volunteers. A stable chloramine-T solution in isopropyl alcohol may be suggested for intact skin antisepsis.

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

PubMed

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.

Antimicrobial Efficacy of Multipurpose Disinfecting Solutions in the Presence of Contact Lenses and Lens Cases.

PubMed

Gabriel, Manal M; McAnally, Cindy; Bartell, John

2018-03-01

The aim of this study was to use antimicrobial efficacy endpoint methodology to determine compatibility of multipurpose disinfecting solutions (MPSs), lens cases, and hydrogel lenses for disinfection (AEEMC) against International Organization for Standardization (ISO)-specified microorganisms and clinical ocular isolates of Stenotrophomonas maltophilia. Six MPSs (PQ/Aldox 1, 2, and 3; PQ/Alexidine; PQ/PHMB; and PHMB) were challenged against ISO-specified microorganisms and S. maltophilia using the AEEMC test. AEEMC tests were performed with and without balafilcon A, etafilcon A, and senofilcon A lenses in lens cases with organic soil. Exposure times included disinfection time (DT) and 24 hr. Additionally, all six MPSs were challenged with two strains of S. maltophilia, based on the ISO Stand-alone test. The efficacy against bacteria for PQ/Aldox and PQ/Alexidine MPSs was not diminished by the presence of lenses. The efficacy of PQ/PHMB and PHMB MPSs against Serratia marcescens was significantly reduced compared with the no-lens control at DT for at least one lens type. The PHMB MPS with lenses present also demonstrated reduced efficacy against Staphylococcus aureus at DT versus the control. PQ/Aldox MPSs retained activity against Fusarium solani with lenses present; however, all other test MPSs demonstrated reduced F. solani efficacy at DT with lenses present. With lenses, all MPSs showed reduced efficacy against Candida albicans. AEEMC antimicrobial efficacy test results vary based on challenge microorganism, contact lenses, and MPS biocide systems. This study highlights the importance of evaluating MPSs for compatibility with lenses and lens cases.

Antimicrobial Efficacy of Multipurpose Disinfecting Solutions in the Presence of Contact Lenses and Lens Cases

PubMed Central

McAnally, Cindy; Bartell, John

2018-01-01

Objective: The aim of this study was to use antimicrobial efficacy endpoint methodology to determine compatibility of multipurpose disinfecting solutions (MPSs), lens cases, and hydrogel lenses for disinfection (AEEMC) against International Organization for Standardization (ISO)–specified microorganisms and clinical ocular isolates of Stenotrophomonas maltophilia. Methods: Six MPSs (PQ/Aldox 1, 2, and 3; PQ/Alexidine; PQ/PHMB; and PHMB) were challenged against ISO-specified microorganisms and S. maltophilia using the AEEMC test. AEEMC tests were performed with and without balafilcon A, etafilcon A, and senofilcon A lenses in lens cases with organic soil. Exposure times included disinfection time (DT) and 24 hr. Additionally, all six MPSs were challenged with two strains of S. maltophilia, based on the ISO Stand-alone test. Results: The efficacy against bacteria for PQ/Aldox and PQ/Alexidine MPSs was not diminished by the presence of lenses. The efficacy of PQ/PHMB and PHMB MPSs against Serratia marcescens was significantly reduced compared with the no-lens control at DT for at least one lens type. The PHMB MPS with lenses present also demonstrated reduced efficacy against Staphylococcus aureus at DT versus the control. PQ/Aldox MPSs retained activity against Fusarium solani with lenses present; however, all other test MPSs demonstrated reduced F. solani efficacy at DT with lenses present. With lenses, all MPSs showed reduced efficacy against Candida albicans. Conclusions: AEEMC antimicrobial efficacy test results vary based on challenge microorganism, contact lenses, and MPS biocide systems. This study highlights the importance of evaluating MPSs for compatibility with lenses and lens cases. PMID:27598555

Resistance to Antibiotics, Biocides, Preservatives and Metals in Bacteria Isolated from Seafoods: Co-Selection of Strains Resistant or Tolerant to Different Classes of Compounds

PubMed Central

Romero, José L.; Grande Burgos, María J.; Pérez-Pulido, Rubén; Gálvez, Antonio; Lucas, Rosario

2017-01-01

Multi-drug resistant bacteria (particularly those producing extended-spectrum β-lactamases) have become a major health concern. The continued exposure to antibiotics, biocides, chemical preservatives, and metals in different settings such as the food chain or in the environment may result in development of multiple resistance or co-resistance. The aim of the present study was to determine multiple resistances (biocides, antibiotics, chemical preservatives, phenolic compounds, and metals) in bacterial isolates from seafoods. A 75.86% of the 87 isolates studied were resistant to at least one antibiotic or one biocide, and 6.90% were multiply resistant to at least three biocides and at least three antibiotics. Significant (P < 0.05) moderate or strong positive correlations were detected between tolerances to biocides, between antibiotics, and between antibiotics with biocides and other antimicrobials. A sub-set of 30 isolates selected according to antimicrobial resistance profile and food type were identified by 16S rDNA sequencing and tested for copper and zinc tolerance. Then, the genetic determinants for biocide and metal tolerance and antibiotic resistance were investigated. The selected isolates were identified as Pseudomonas (63.33%), Acinetobacter (13.33%), Aeromonas (13.33%), Shewanella, Proteus and Listeria (one isolate each). Antibiotic resistance determinants detected included sul1 (43.33% of tested isolates), sul2 (6.66%), blaTEM (16.66%), blaCTX−M (16.66%), blaPSE (10.00%), blaIMP (3.33%), blaNDM−1 (3.33%), floR (16.66%), aadA1 (20.0%), and aac(6′)-Ib (16.66%). The only biocide resistance determinant detected among the selected isolates was qacEΔ1 (10.00%). A 23.30 of the selected isolates were able to grow on media containing 32 mM copper sulfate, and 46.60% on 8 mM zinc chloride. The metal resistance genes pcoA/copA, pcoR, and chrB were detected in 36.66, 6.66, and 13.33% of selected isolates, respectively. Twelve isolates tested positive for both metal and antibiotic resistance genes, including one isolate positive for the carbapenemase gene blaNDM−1 and for pcoA/copA. These results suggest that exposure to metals could co-select for antibiotic resistance and also highlight the potential of bacteria on seafoods to be involved in the transmission of antimicrobial resistance genes. PMID:28912764

Information technologies in public health management: a database on biocides to improve quality of life.

PubMed

Roman, C; Scripcariu, L; Diaconescu, Rm; Grigoriu, A

2012-01-01

Biocides for prolonging the shelf life of a large variety of materials have been extensively used over the last decades. It has estimated that the worldwide biocide consumption to be about 12.4 billion dollars in 2011, and is expected to increase in 2012. As biocides are substances we get in contact with in our everyday lives, access to this type of information is of paramount importance in order to ensure an appropriate living environment. Consequently, a database where information may be quickly processed, sorted, and easily accessed, according to different search criteria, is the most desirable solution. The main aim of this work was to design and implement a relational database with complete information about biocides used in public health management to improve the quality of life. Design and implementation of a relational database for biocides, by using the software "phpMyAdmin". A database, which allows for an efficient collection, storage, and management of information including chemical properties and applications of a large quantity of biocides, as well as its adequate dissemination into the public health environment. The information contained in the database herein presented promotes an adequate use of biocides, by means of information technologies, which in consequence may help achieve important improvement in our quality of life.

Image Cytometric Analysis of Algal Spores for Evaluation of Antifouling Activities of Biocidal Agents.

PubMed

Il Koo, Bon; Lee, Yun-Soo; Seo, Mintae; Seok Choi, Hyung; Leng Seah, Geok; Nam, Taegu; Nam, Yoon Sung

2017-07-31

Chemical biocides have been widely used as marine antifouling agents, but their environmental toxicity impose regulatory restriction on their use. Although various surrogate antifouling biocides have been introduced, their comparative effectiveness has not been well investigated partly due to the difficulty of quantitative evaluation of their antifouling activity. Here we report an image cytometric method to quantitatively analyze the antifouling activities of seven commercial biocides using Ulva prolifera as a target organism, which is known to be a dominant marine species causing soft fouling. The number of spores settled on a substrate is determined through image analysis using the intrinsic fluorescence of chlorophylls in the spores. Pre-determined sets of size and shape of spores allow for the precise determination of the number of settled spores. The effects of biocide concentration and combination of different biocides on the spore settlement are examined. No significant morphological changes of Ulva spores are observed, but the amount of adhesive pad materials is appreciably decreased in the presence of biocides. It is revealed that the growth rate of Ulva is not directly correlated with the antifouling activities against the settlement of Ulva spores. This work suggests that image cytometric analysis is a very convenient, fast-processable method to directly analyze the antifouling effects of biocides and coating materials.

Use of a predictive protocol to measure the antimicrobial resistance risks associated with biocidal product usage.

PubMed

Wesgate, Rebecca; Grasha, Pierre; Maillard, Jean-Yves

2016-04-01

In this study we assessed the propensity of biocide exposure in the development of antimicrobial resistance in bacteria. Our protocol is based on reporting changes in established antimicrobial susceptibility profiles in biocides and antibiotics after during use exposure to a product. The during use exposure reflects worse conditions of product use during application. It differs from the term low concentration, which usually reflects a concentration below the minimal inhibitory concentration, but not necessarily a concentration that occurs in practice. Our results showed that exposure to triclosan (0.0004%) was associated with a high risk of developing resistance and cross-resistance in Staphylococcus aureus and Escherichia coli. This was not observed with exposure to chlorhexidine (0.00005%) or a hydrogen peroxide-based biocidal product (in during use conditions). Interestingly, exposure to a low concentration of hydrogen peroxide (0.001%) carried a risk of emerging resistance to antibiotics if the presence of the oxidizing agent was maintained. We observed a number of unstable clinical resistances to antibiotics after exposure to the cationic biocide and oxidizing agent, notably to tobramycin and ticarcillin-clavulanic acid. Using a decision tree based on the change in antimicrobial susceptibility test results, we were able to provide information on the effect of biocide exposure on the development of bacterial resistance to antimicrobials. Such information should address the call from the U.S. Food and Drug Administration and European Union Biocidal Products Regulation for manufacturers to provide information on antimicrobial resistance and cross-resistance in bacteria after the use of their product. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Determination of biocides as well as some biocide metabolites from facade run-off waters by solid phase extraction and high performance liquid chromatographic separation and tandem mass spectrometry detection.

PubMed

Bester, K; Lamani, X

2010-08-06

Biocides are used to protect buildings, boats, and other materials from microbial infestations. A huge variety of compounds are being used: isothiazolinones, e.g., to prevent bacterial growth in paints, triazines and phenylureas against algal growth on water exposed materials while carbamates are used against fungal investations. However these biocides can be leached from the respective materials. As these are very effective compounds it is important to know the concentrations of these biocides in the leachates as well as their leaching behaviour to assess their risk to the environment. In this study, a method for the determination of biocides from facade material run-off water by means of high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) was developed. Due to the amphiphilic character and the expected varying pH-values in the samples, the extractions as well as the HPLC-method development proved to be demanding. The water samples (leachates) were buffered with a phosphate buffer to pH 7. As some of the biocides are very hydrophilic, different SPE cartridges were tested to identify the SPE material with the highest recovery rates for all compounds. For gaining a good separation, analyte trapping was performed on the HPLC column. Quantification was performed using a mass spectrometer in multi-reaction monitoring with two transitions per compound. The final recovery rates were conducted using a cartridge with a divenylbenzyl polymer sorbent. A combination of methanol and acetonitrile as eluents was used to reach recovery rates in the range of 70-100%. The limit of quantification for the compounds of interest ranged from 0.01 to 0.1 microg/L. Copyright 2010 Elsevier B.V. All rights reserved.

Biocide and antibiotic susceptibility of Salmonella isolates obtained before and after cleaning at six Danish pig slaughterhouses.

PubMed

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

2014-07-02

Salmonella sp. continues to be one of the most important foodborne pathogens. Control measures in terms of cleaning and disinfection on food production plants are very important for limiting the risk of contaminated food products to reach the consumer. In the last decade concern has arisen that bacteria exposed to disinfectants can develop resistance toward disinfectants and can have a higher risk of developing antibiotic resistance. The objectives of this study were to examine the prevalence of biocide resistant Salmonella sp. in Danish pig slaughterhouses, to evaluate if there was a correlation between susceptibilities to biocides and antibiotics, and to examine if cleaning and disinfection select isolates with changed susceptibility toward biocides or antibiotics. Salmonella sp. was isolated from the environment in Danish pig slaughterhouses before and after cleaning and disinfection. The susceptibility toward three different biocides, triclosan and two commercial disinfection products: Desinfect Maxi, a quaternary ammonium compound, and Incimaxx DES, an acetic compound, was determined. We found no resistance toward the biocides tested, but we did find that isolates obtained after cleaning had higher minimum inhibitory concentration (MIC) values toward one of the disinfectants (Incimaxx DES) compared to isolates obtained before cleaning and disinfection. This could indicate selection of strains that are more tolerant, due to the cleaning and disinfection. Furthermore, we found that there was a weak statistical correlation between MICs toward the biocides and some antibiotics, but no difference in log(MIC)s toward antibiotics between isolates obtained before and after cleaning, nor did we find any difference in the number of resistances of isolates obtained before and after cleaning and disinfection. Copyright © 2014 Elsevier B.V. All rights reserved.

40 CFR 430.106 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart J...

Biofilm Surface Density Determines Biocide Effectiveness

PubMed Central

Bas, Sara; Kramer, Mateja; Stopar, David

2017-01-01

High resistance of biofilms for chemical challenges is a serious industrial and medical problem. In this work a gradient of surface covered with biofilm has been produced and correlated to the effectiveness of different commercially available oxidative biocides. The results for thin Escherichia coli biofilms grown in rich media supplemented with glucose or lactose on glass or poly methyl methacrylate surfaces indicate that the effectiveness of hydrogen peroxide or chlorine dioxide and quaternary ammonium compounds is inversely proportional to the fraction of the surface covered with the biofilm. In areas where biofilm covered more than 90% of the available surface the biocide treatment was inefficient after 60 min of incubation. The combined effect of oxidant and surfactant increased the effectiveness of the biocide. On the other hand, the increased biofilm viscoelasticity reduced biocide effectiveness. The results emphasize differential biocide effectiveness depending on the fraction of the attached bacterial cells. The results suggest that biofilm biocide resistance is an acquired property that increases with biofilm maturation. The more dense sessile structures present lower log reductions compared to less dense ones. PMID:29276508

Lens material and formulation of multipurpose solutions affects contact lens disinfection.

PubMed

Santos, Lívia; Oliveira, Rosário; Oliveira, M Elisabete C D Real; Azeredo, Joana

2011-08-01

To assess the disinfection efficacy of multipurpose solutions (MPS) against different bacterial species adhered either to silicon hydrogel or to conventional hydrogel contact lenses (CLs). The influences of the MPS formulation and the chemical composition of the lens material were investigated. This investigation followed the standard 14729, which establishes the guidelines for assessing CL disinfecting solutions. Two commercially available (Opti-Free(®) Express(®) and Renu(®) Multiplus) solutions and one recalled solution (Complete(®) MoisturePlus™) were used in this study. After disinfection, the number of survivors was estimated by the colony forming units' method. The lens material appears to influence disinfection. The conventional hydrogel polymacon exhibited the highest disinfection scores, a fact that should be related with the lack of electrostatic attraction towards the biocides and its hydrophilicity. The MPS formulation appears to have influence in disinfection efficacy as well. For most adhered bacteria, Opti-Free(®) was capable of reducing cell concentration in 4-log. Disinfection results from multivariate factors and this study confirmed that the lens material and the MPS play a very important role in the disinfection efficacy of CL. Copyright © 2011. Published by Elsevier Ltd.

Diatom communities on commercial biocidal fouling control coatings after one year of immersion in the marine environment.

PubMed

Muthukrishnan, Thirumahal; Dobretsov, Sergey; De Stefano, Mario; Abed, Raeid M M; Kidd, Barry; Finnie, Alistair A

2017-08-01

Little is known about the effect of commercial biocidal fouling control coatings on fouling diatom communities and their growth forms after long periods of exposure in the marine tropical environment. The current study investigated the abundance and composition of fouling diatom communities developed on 11 commercially available biocidal antifouling coatings, covering the three main technology types in recent historic use (Self-Polishing Copolymers, Self-Polishing Hybrid and Controlled Depletion Polymers) after one year of static immersion at two locations in Muscat, Oman (Marina Shangri La and Marina Bandar Rowdha). Light microscopy demonstrated that the total abundance of diatoms and the relative abundance of growth forms were significantly affected by the choice of biocidal antifouling coating and experimental location. Using scanning electron microscopy, a total of 21 diatom genera were identified which were grouped into adnate, motile, plocon and erect growth forms. The adnate growth forms, mainly the genera Amphora, Cocconeis and Mastogloia, dominated the other growth forms in terms of their relative abundance. Current results revealed the importance of exposure location and choice of biocidal antifouling coating on the relative abundance of diatom growth forms. Copyright © 2017 Elsevier Ltd. All rights reserved.

The aluminium and iodine pentoxide reaction for the destruction of spore forming bacteria.

PubMed

Clark, Billy R; Pantoya, Michelle L

2010-10-21

The threat of biological weapons is a major concern in the present day and has led to studying methods to neutralize spore forming bacteria. A new technique involves the use of a thermite reaction that exhibits biocidal properties to limit bacterial growth. The objective was to examine the influence on bacteria growth upon spore exposure to thermite reactions with and without biocidal properties. Three thermites are considered: two that have biocidal properties (aluminium (Al) combined with iodine pentoxide (I(2)O(5)) and Al combined with silver oxide (Ag(2)O)); and, one that produces a highly exothermic reaction but has no biocidal properties (Al combined with iron oxide (Fe(2)O(3))). Results show that Al + I(2)O(5) is extremely effective at neutralizing spores after only one hour of exposure. The temperature generated by the reaction was not determined to be an influential factor affecting spore growth kinetics. Further analysis of the thermite reactions revealed that the Al + I(2)O(5) reaction produces iodine gas that effectively interacts with the spores and neutralizes bacteria growth, while the Al + Ag(2)O reaction temperature does not vaporize silver. In the condensed phase silver does not interact with the spores enough to neutralize bacteria growth. This study gives evidence that a thermite can be used as a stable transportation and delivery system for biocidal gas.

NANOTECHNOLOGY: A NOVEL APPROACH TO PREVENT BIOCIDE LEACHING

EPA Science Inventory

This project will demonstrate the environmental benefits of introducing biocide into wood using hydrophobic nanoparticles as a delivery vehicle and controlled release device for organic and inorganic biocides. The primary benefits expected from use of nanoparticles as controll...

Emission of biocides from treated materials: test procedures for water and air.

PubMed

Schoknecht, Ute; Wegner, Robby; Horn, Wolfgang; Jann, Oliver

2003-01-01

Methods for the determination of biocide emissions from treated materials into water and air were developed and tested in order to support a comparative ecological assessment of biocidal products. Leaching tests, experiments with simulated rain, extraction cleaning of carpets and emission chamber tests were performed with a series of treated materials. The experiments focused on the effect of changes in the procedure as well as characteristics of the specimens and demonstrate the suitability of the proposed methods for biocides of different product types. It was demonstrated that emissions of biocides into water can be compared on the basis of leaching tests in which the emission kinetics of the active ingredients are recorded. However, the water volume per surface area and the timetable for water changes have to be defined in such tests. Functions of flux rates related to time can be well described for inorganic compounds, whereas modelling of the data is more complicated for organic substances. Emission chamber tests using 20-litre and 23-litre glass exsiccators, originally developed to study volatile organic compounds, were successfully adapted for the investigation of the emission of biocides from treated materials which are usually semi volatile organic compounds. However test parameters and the method of analysis have to be adapted to the substances to be determined. Generally, it was found that the emission curves for the semi volatile organic compounds investigated differ from those of volatile organic compounds.

Leaching of biocides from building facades: Upscaling of a local two-region leaching model to the city scale

NASA Astrophysics Data System (ADS)

Coutu, S.; Rota, C.; Rossi, L.; Barry, D. A.

2011-12-01

Facades are protected by paints that contain biocides as protection against degradation. These biocides are leached by rainfall (albeit at low concentrations). At the city scale, however, the surface area of building facades is significant, and leached biocides are a potential environmental risk to receiving waters. A city-scale biocide-leaching model was developed based on two main steps. In the first step, laboratory experiments on a single facade were used to calibrate and validate a 1D, two-region phenomenological model of biocide leaching. The same data set was analyzed independently by another research group who found empirically that biocide leachate breakthrough curves were well represented by a sum of two exponentials. Interestingly, the two-region model was found analytically to reproduce this functional form as a special case. The second step in the method is site-specific, and involves upscaling the validated single facade model to a particular city. In this step, (i) GIS-based estimates of facade heights and areas are deduced using the city's cadastral data, (ii) facade flow is estimated using local meteorological data (rainfall, wind direction) and (iii) paint application rates are modeled as a stochastic process based on manufacturers' recommendations. The methodology was applied to Lausanne, Switzerland, a city of about 200,000 inhabitants. Approximately 30% of the annually applied mass of biocides was estimated to be released to the environment.

Biocides in hydraulic fracturing fluids: a critical review of their usage, mobility, degradation, and toxicity.

PubMed

Kahrilas, Genevieve A; Blotevogel, Jens; Stewart, Philip S; Borch, Thomas

2015-01-06

Biocides are critical components of hydraulic fracturing ("fracking") fluids used for unconventional shale gas development. Bacteria may cause bioclogging and inhibit gas extraction, produce toxic hydrogen sulfide, and induce corrosion leading to downhole equipment failure. The use of biocides such as glutaraldehyde and quaternary ammonium compounds has spurred a public concern and debate among regulators regarding the impact of inadvertent releases into the environment on ecosystem and human health. This work provides a critical review of the potential fate and toxicity of biocides used in hydraulic fracturing operations. We identified the following physicochemical and toxicological aspects as well as knowledge gaps that should be considered when selecting biocides: (1) uncharged species will dominate in the aqueous phase and be subject to degradation and transport whereas charged species will sorb to soils and be less bioavailable; (2) many biocides are short-lived or degradable through abiotic and biotic processes, but some may transform into more toxic or persistent compounds; (3) understanding of biocides' fate under downhole conditions (high pressure, temperature, and salt and organic matter concentrations) is limited; (4) several biocidal alternatives exist, but high cost, high energy demands, and/or formation of disinfection byproducts limits their use. This review may serve as a guide for environmental risk assessment and identification of microbial control strategies to help develop a sustainable path for managing hydraulic fracturing fluids.

Bactericidal Specificity and Resistance Profile of Poly(Quaternary Ammonium) Polymers and Protein-Poly(Quaternary Ammonium) Conjugates.

PubMed

Ji, Weihang; Koepsel, Richard R; Murata, Hironobu; Zadan, Sawyer; Campbell, Alan S; Russell, Alan J

2017-08-14

Antibacterial polymers are potentially powerful biocides that can destroy bacteria on contact. Debate in the literature has surrounded the mechanism of action of polymeric biocides and the propensity for bacteria to develop resistance to them. There has been particular interest in whether surfaces with covalently coupled polymeric biocides have the same mechanism of action and resistance profile as similar soluble polymeric biocides. We designed and synthesized a series of poly(quaternary ammonium) polymers, with tailorable molecular structures and architectures, to engineer their antibacterial specificity and their ability to delay the development of bacterial resistance. These linear poly(quaternary ammonium) homopolymers and block copolymers, generated using atom transfer radical polymerization, had structure-dependent antibacterial specificity toward Gram positive and negative bacterial species. When single block copolymers contained two polymer segments of differing antibacterial specificity, the polymer combined the specificities of its two components. Nanoparticulate human serum albumin-poly(quaternary ammonium) conjugates of these same polymers, synthesized via "grafting from" atom transfer radical polymerization, were strongly biocidal and also exhibited a marked decrease in the rate of bacterial resistance development relative to linear polymers. These protein-biocide conjugates mimicked the behavior of surface-presented polycationic biocides rather than their nonproteinaceous counterparts.

40 CFR 430.76 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... limitations are only applicable at facilities where chlorophenolic-containing biocides are used. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. Zinc limitations are only applicable at facilities where zinc...

40 CFR 430.76 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... limitations are only applicable at facilities where chlorophenolic-containing biocides are used. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. Zinc limitations are only applicable at facilities where zinc...

40 CFR 430.65 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart F [NSPS] Pollutant...

40 CFR 430.15 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart A [NSPS] Pollutant...

40 CFR 430.45 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart D [NSPS for...

40 CFR 430.35 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart C [NSPS for...

Biocidal packaging for pharmaceuticals, foods, and other perishables.

PubMed

Larson, Alyssa M; Klibanov, Alexander M

2013-01-01

Many consumer goods must be protected from bacterial and fungal colonization to ensure their integrity and safety. By making these items' packaging biocidal, the interior environment can be preserved from microbial spoilage without altering the products themselves. Herein we briefly review this concept, referred to as active packaging, and discuss existing methods for constructing active packaging systems. They are based on either packaging materials that release biocides or those that are themselves intrinsically biocidal (or biostatic), with numerous variations within each category.

In Vitro Activity of Glucosinolates and Their Degradation Products against Brassica-Pathogenic Bacteria and Fungi

PubMed Central

Sotelo, T.; Lema, M.; Soengas, P.; Cartea, M. E.

2014-01-01

Glucosinolates (GSLs) are secondary metabolites found in Brassica vegetables that confer on them resistance against pests and diseases. Both GSLs and glucosinolate hydrolysis products (GHPs) have shown positive effects in reducing soil pathogens. Information about their in vitro biocide effects is scarce, but previous studies have shown sinigrin GSLs and their associated allyl isothiocyanate (AITC) to be soil biocides. The objective of this work was to evaluate the biocide effects of 17 GSLs and GHPs and of leaf methanolic extracts of different GSL-enriched Brassica crops on suppressing in vitro growth of two bacterial (Xanthomonas campestris pv. campestris and Pseudomonas syringae pv. maculicola) and two fungal (Alternaria brassicae and Sclerotinia scletoriorum) Brassica pathogens. GSLs, GHPs, and methanolic leaf extracts inhibited the development of the pathogens tested compared to the control, and the effect was dose dependent. Furthermore, the biocide effects of the different compounds studied were dependent on the species and race of the pathogen. These results indicate that GSLs and their GHPs, as well as extracts of different Brassica species, have potential to inhibit pathogen growth and offer new opportunities to study the use of Brassica crops in biofumigation for the control of multiple diseases. PMID:25362058

The wide spectrum high biocidal potency of Bioxy formulation when dissolved in water at different concentrations

PubMed Central

Dagher, Fadi

2017-01-01

Traditional surface disinfectants that have long been applied in medicine, animal husbandry, manufacturing and institutions are inconvenient at best and dangerous at worst. Moreover, some of these substances have adverse environmental impacts: for example, quaternary ammonium compounds (“quats”) are reproductive toxicants in both fish and mammals. Halogens are corrosive both to metals and living tissues, are highly reactive, can be readily neutralized by metals, and react with organic matter to form toxic, persistent by-products such as dioxins and furans. Aldehydes may be carcinogenic to both human and animals upon repeated exposures, are corrosive, cross-link living tissues and many synthetic materials, and may lose efficacy when pathogens enzymatically adapt to them. Alcohols are flammable and volatile and can be enzymatically degraded by certain bacterial pathogens. Quats are highly irritating to mucous membranes and over time can induce pathogen resistance, especially if they are not alternated with functionally different disinfectants. In contrast, peracetic acid (PAA), a potent oxidizer, liberates hydrogen peroxide (itself a disinfectant), biodegrades to carbon dioxide, water and oxygen, and is at least as efficacious as contact biocides e.g., halogens and aldehydes. Nevertheless, the standard form of liquid PAA is highly corrosive, is neutralized by metals and organic matter, gives off noxious odours and must be stored in vented containers. For the reasons stated above, Bioxy formulations were developed, a series of powder forms of PAA, which are odourless, stable in storage and safe to transport and handle. They generate up to 10% PAA in situ when dissolved in water. A 0.2% aqueous solution of Bioxy (equivalent to 200 ppm PAA) effected a 6.76 log reduction in Methicillin-resistant Staphylococcus aureus (MRSA) within 2 minutes after application. A 5% aqueous solution of Bioxy achieved a 3.93 log reduction in the bovine tuberculosis bacillus Mycobacterium bovis, within 10 minutes after contact. A 1% solution of Bioxy reduced vancomycin-resistant enterococci (VRE) and Pseudomonas aeruginosa by 6.31 and 7.18 logs, respectively, within 3 minutes after application. A 0.5% solution of Bioxy inactivated porcine epidemic diarrhea virus (PEDV) within 15 minutes of contact, and a 5% solution of Bioxy realized a 5.36 log reduction in the spores of Clostridium difficile within 10 minutes of application. In summary, Bioxy is safe and easy to transport and store, poses negligible human, animal and environmental health risks, shows high levels of pathogen control efficacy and does not induce microbial resistance. Further investigations are recommended to explore its use as an industrial biocide. PMID:28207828

The wide spectrum high biocidal potency of Bioxy formulation when dissolved in water at different concentrations.

PubMed

Dagher, Dori; Ungar, Ken; Robison, Richard; Dagher, Fadi

2017-01-01

Traditional surface disinfectants that have long been applied in medicine, animal husbandry, manufacturing and institutions are inconvenient at best and dangerous at worst. Moreover, some of these substances have adverse environmental impacts: for example, quaternary ammonium compounds ("quats") are reproductive toxicants in both fish and mammals. Halogens are corrosive both to metals and living tissues, are highly reactive, can be readily neutralized by metals, and react with organic matter to form toxic, persistent by-products such as dioxins and furans. Aldehydes may be carcinogenic to both human and animals upon repeated exposures, are corrosive, cross-link living tissues and many synthetic materials, and may lose efficacy when pathogens enzymatically adapt to them. Alcohols are flammable and volatile and can be enzymatically degraded by certain bacterial pathogens. Quats are highly irritating to mucous membranes and over time can induce pathogen resistance, especially if they are not alternated with functionally different disinfectants. In contrast, peracetic acid (PAA), a potent oxidizer, liberates hydrogen peroxide (itself a disinfectant), biodegrades to carbon dioxide, water and oxygen, and is at least as efficacious as contact biocides e.g., halogens and aldehydes. Nevertheless, the standard form of liquid PAA is highly corrosive, is neutralized by metals and organic matter, gives off noxious odours and must be stored in vented containers. For the reasons stated above, Bioxy formulations were developed, a series of powder forms of PAA, which are odourless, stable in storage and safe to transport and handle. They generate up to 10% PAA in situ when dissolved in water. A 0.2% aqueous solution of Bioxy (equivalent to 200 ppm PAA) effected a 6.76 log reduction in Methicillin-resistant Staphylococcus aureus (MRSA) within 2 minutes after application. A 5% aqueous solution of Bioxy achieved a 3.93 log reduction in the bovine tuberculosis bacillus Mycobacterium bovis, within 10 minutes after contact. A 1% solution of Bioxy reduced vancomycin-resistant enterococci (VRE) and Pseudomonas aeruginosa by 6.31 and 7.18 logs, respectively, within 3 minutes after application. A 0.5% solution of Bioxy inactivated porcine epidemic diarrhea virus (PEDV) within 15 minutes of contact, and a 5% solution of Bioxy realized a 5.36 log reduction in the spores of Clostridium difficile within 10 minutes of application. In summary, Bioxy is safe and easy to transport and store, poses negligible human, animal and environmental health risks, shows high levels of pathogen control efficacy and does not induce microbial resistance. Further investigations are recommended to explore its use as an industrial biocide.

Assessment of Silver Based Disinfection Technology for CEV and Future US Spacecraft

NASA Technical Reports Server (NTRS)

Callahan, Michael R.; Adam, Niklas M.; Roberts, Michael S.; Garland, Jay L.; Sager, John C.; Pickering, Karen D.

2007-01-01

Silver biocide offers a potential advantage over iodine, the current state-of-the-art in US spacecraft disinfection technology, in that silver can be safely consumed by the crew. As such, silver may reduce the overall complexity and mass of future spacecraft potable water systems, particularly those used to support long duration missions. A primary technology gap identified for the use of silver biocide is one of material compatibility. Wetted materials of construction are required to be selected such that silver ion concentrations can be maintained at biocidally effective levels. Preliminary data on silver biocide depletion rates in heritage spacecraft potable water system wetted-materials of construction has been gathered as part of a multi-phase test project aimed at the characterization of silver based biocide technology through: development of preferred materials lists, investigation of silver biocide forms and delivery methods, down-selection of silver biocide technologies, and integrated testing. A 10% - 20% loss in silver ion concentration per day was observed for acid passivated Nitronic 40 tubing with surface area to volume (S/V) ratios of approximately 4.59 cm-1. The Nitronic 40 tubes were tested both with and without biocide pretreatment. Silver biocide depletion was also observed at approximately 0.1% per day for the first 35 days of exposure to acid passivated Inconel 718 coupon, S/V of approximately 0.14 cm-1. Surface analysis by scanning election microscopy (SEM) suggested deposition of silver metal on both test materials. SEM analysis also provided evidence of potential variability in the passivation process for tube configuration of the Nitronic 40 test apparatus. These preliminary results are presented and discussed herein, along with the current project status.

40 CFR 430.105 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart J [NSPS for secondary fiber non-deink facilities where paperboard from wastepaper is...

40 CFR 430.115 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-containing biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart K [NSPS for non-integrated mills where fine paper is...

Chemistry of Durable and Regenerable Biocidal Textiles

ERIC Educational Resources Information Center

Gang Sun; Worley, S. Dave

2005-01-01

Antimicrobial textiles can be categorized into two groups, biocidal and biostatic materials, according to their functions. Biostatic functions refer to inhibiting growth of microorganisms on textiles and preventing the materials from biodegradation and biocidal materials are able to kill microorganisms, thus eliminating their growth, sterilizing…

Crew Exploration Vehicle Potable Water System Verification Description

NASA Technical Reports Server (NTRS)

Tuan, George; Peterson, Laurie J.; Vega, Leticia M.

2010-01-01

A stored water system on the crew exploration vehicle (CEV) will supply the crew with potable water for: drinking and food rehydration, hygiene, medical needs, sublimation, and various contingency situations. The current baseline biocide for the stored water system is ionic silver, similar in composition to the biocide used to maintain the quality of the water, transferred from the orbiter to the International Space Station, stored in contingency water containers. In the CEV water system, a depletion of the ionic silver biocide is expected due to ionic silver-plating onto the surfaces of materials within the CEV water system, thus negating its effectiveness as a biocide. Because this may be the first time NASA is considering a stored water system for long-term missions that do not maintain a residual biocide, a team of experts in materials compatibility, biofilms and point-of-use filters, surface treatment and coatings, and biocides has been created to pinpoint concerns and perform the testing that will help alleviate concerns related to the CEV water system.

Bioactivity and laundering resistance of five commercially available, factory-treated permethrin-impregnated fabrics for the prevention of mosquito-borne diseases: the need for a standardized testing and licensing procedure.

PubMed

Faulde, Michael K; Pages, Frederic; Uedelhoven, Waltraud

2016-04-01

Personal protective measures against hematophagous vectors constitute the first line of defense against arthropod-borne diseases. In this regard, a major advance has been the development of residual insecticides that can be impregnated into clothing. Currently, however, information on specific treatment procedures, initial insecticide concentrations, arthropod toxicity, residual activity, and laundering resistance is either fragmentary or non-existent, and no World Health Organization Pesticides Evaluation Scheme or other guidelines exist for the standardized testing and licensing of insecticide-treated clothing. The aim of this study was to analyze the insecticide content, contact toxicity, laundering resistance, and residual activity of five commercially available and commonly used permethrin-treated fabrics-Insect Shield, ExOfficio, Sol's Monarch T-shirts, battle dress uniforms (BDUs), and Labonal socks-against vector-competent Aedes aegypti, Anopheles stephensi, and Culex pipiens mosquitoes under laboratory conditions. Prior to laundering, permethrin concentrations ranged from 4300 to 870 mg/m(2) whereas, after 100 defined machine launderings, the remaining permethrin content fell to between 1800 and 20 mg/m(2), a percentage permethrin loss of 58.1 to 98.5 %. The highest 99 % knockdown (KD99) efficacy of permethrin was detected in Ae. aegypti, followed by An. stephensi and Cx. pipiens demonstrating that Ae. aegypti is the most sensitive species and Cx. pipiens the least sensitive. After 100 launderings, the remaining biocidal efficacy differed markedly among the five brands, with KD99 times varying from 38.8 ± 2.9 to >360 min for Ae. aegypti, from 44 ± 3.5 to >360 min for An. stephensi, and from 98 ± 10.6 to >360 min for Cx. pipiens. Overall, the ranking of the residual biocidal efficacies within the five brands tested was as follows: BDU ≈ Labonal > Sol's Monarch > ExOfficio > Insect Shield. When applying German Armed Forces licensing conditions, none of the four products available in the civilian market would completely meet all the necessary efficacy and safety requirements fulfilled by BDUs. Therefore, we strongly recommend standardized testing and licensing procedures for insecticide-treated clothing, with defined cutoff values for initial maximum and post-laundering minimum concentrations of permethrin as well as figures for permethrin migration rates, arthropod toxicity, homogeneity on fabrics, residual activity, and laundering resistance.

Nanotechnology : implications for the wood preservation industry

Treesearch

Carol A. Clausen

2007-01-01

Nanotechnology has the potential to greatly impact the wood protection industry through the creation of nanomaterials with unique properties. Nanobiocides may find applications as co-biocides, or may alter treatability properties such as penetration and biocide distribution. Nanocarrier delivery systems may increase the applications for organic biocides through...

40 CFR 430.16 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... pretreatment standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart A [PSES...

40 CFR 430.107 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... standards for new sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart J [PSNS for secondary fiber non-deink facilities where paperboard from wastepaper is...

40 CFR 430.16 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... pretreatment standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart A [PSES...

40 CFR 430.77 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... applicable at facilities where chlorophenolic-containing biocides are used. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. Zinc limitations are only applicable at facilities where zinc hydrosulfite is used as a bleaching...

40 CFR 430.37 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... standards for new sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart C [PSNS for unbleached kraft facilities where linerboard is produced] Pollutant or...

40 CFR 430.96 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... pretreatment standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart I [Facilities...

40 CFR 430.77 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... applicable at facilities where chlorophenolic-containing biocides are used. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. Zinc limitations are only applicable at facilities where zinc hydrosulfite is used as a bleaching...

40 CFR 430.97 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... for new sources (PSNS) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart I [Facilities where fine paper is produced] Pollutant or pollutant property PSNS Maximum...

40 CFR 430.95 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart I [Facilities where fine paper is produced] [NSPS] Pollutant or pollutant property Kg/kkg...

Adaptive Resistance to Biocides in Salmonella enterica and Escherichia coli O157 and Cross-Resistance to Antimicrobial Agents

PubMed Central

Braoudaki, M.; Hilton, A. C.

2004-01-01

The mechanisms by which bacteria resist killing by antibiotics and biocides are still poorly defined, although repeated exposure to sublethal concentrations of antibacterial agents undoubtedly contributes to their development. This study aimed both to investigate the potential of Salmonella enterica and Escherichia coli O157 for adaptive resistance to commonly used biocides and to determine any cross-resistance to antibiotics. Strains were repeatedly passaged in media containing increasing concentrations of a biocide or antibiotic until adaptive resistance was obtained. A wide panel of antimicrobial agents was then screened by using the adapted strain to determine cross-resistance, if any. Adaptive resistance was readily achieved for both S. enterica and E. coli O157. Cross-resistance in adaptively resistant S. enterica varied with the serotype; Salmonella enterica serovar Enteritidis expressed cross-resistance to chloramphenicol, whereas Salmonella enterica serovar Typhimurium expressed cross-resistance to chlorhexidine. Benzalkonium chloride-resistant Salmonella enterica serovar Virchow showed elevated resistance to chlorhexidine; however, chlorhexidine-resistant Salmonella serovar Virchow did not demonstrate reciprocal cross-resistance to benzalkonium chloride, suggesting specific rather than generic resistance mechanisms. E. coli O157 strains acquired high levels of resistance to triclosan after only two sublethal exposures and, when adapted, repeatedly demonstrated decreased susceptibilities to various antimicrobial agents, including chloramphenicol, erythromycin, imipenem, tetracycline, and trimethoprim, as well as to a number of biocides. These observations raise concern over the indiscriminate and often inappropriate use of biocides, especially triclosan, in situations where they are unnecessary, whereby they may contribute to the development of microbial resistance mechanisms. PMID:14715734

Increased Usage of Antiseptics Is Associated with Reduced Susceptibility in Clinical Isolates of Staphylococcus aureus

PubMed Central

Hardy, Katherine; Sunnucks, Katie; Gil, Hannah; Shabir, Sahida; Trampari, Eleftheria; Hawkey, Peter

2018-01-01

ABSTRACT Hospital-acquired infection is a major cause of morbidity and mortality, and regimes to prevent infection are crucial in infection control. These include the decolonization of vulnerable patients with methicillin-resistant Staphylococcus aureus (MRSA) carriage using antiseptics, including chlorhexidine and octenidine. Concern has been raised, however, regarding the possible development of biocide resistance. In this study, we assembled a panel of S. aureus isolates, including isolates collected before the development of chlorhexidine and octenidine and isolates, from a major hospital trust in the United Kingdom during a period when the decolonization regimes were altered. We observed significant increases in the MIC and minimum bactericidal concentration (MBC) of chlorhexidine in isolates from periods of high usage of chlorhexidine. Isolates with increased MICs and MBCs of octenidine rapidly emerged after octenidine was introduced in the trust. There was no apparent cross-resistance between the two biocidal agents. A combination of variable-number tandem repeat (VNTR) analysis, PCR for qac genes, and whole-genome sequencing was used to type isolates and examine possible mechanisms of resistance. There was no expansion of a single strain associated with decreased biocide tolerance, and biocide susceptibility did not correlate with carriage of qac efflux pump genes. Mutations within the NorA or NorB efflux pumps, previously associated with chlorhexidine export, were identified, however, suggesting that this may be an important mechanism of biocide tolerance. We present evidence that isolates are evolving in the face of biocide challenge in patients and that changes in decolonization regimes are reflected in changes in susceptibility of isolates. PMID:29844113

Comparison of respiratory activity and culturability during monochloramine disinfection of binary population biofilms.

PubMed Central

Stewart, P S; Griebe, T; Srinivasan, R; Chen, C I; Yu, F P; deBeer, D; McFeters, G A

1994-01-01

Biofilm bacteria challenged with monochloramine retained significant respiratory activity, even though they could not be cultured on agar plates. Microbial colony counts on agar media declined by approximately 99.9% after 1 h of disinfection, whereas the number of bacteria stained by a fluorescent redox dye experienced a 93% reduction. Integrated measures of biofilm respiratory activity, including net oxygen and glucose utilization rates, showed only a 10 to 15% reduction. In this biofilm system, measures of microbial respiratory activity and culturability yielded widely differing estimates of biocide efficacy. PMID:8017950

Biocidal Energetic Materials for the Destruction of Spore Forming Bacteria

DTIC Science & Technology

2015-07-01

Bacteria Spore Gas Antibacterial Thermal Unclassified Unclassified Unclassified SAR 47 Suhithi Peiris...naturally antibacterial and biocidal properties using combustion synthesis of mildly energetic reactants; and, (2) engineering an aerosolized spray...of biocidal gases using unique a deflagration synthesis approach. Accomplishments for all years: Major Activity 1: Creating highly porous

40 CFR 430.66 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart F Pollutant or pollutant property PSES...

40 CFR 430.46 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... pretreatment standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart D [PSES for...

40 CFR 430.36 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... pretreatment standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using those biocides. PSES must be attained on or before July 1, 1984: Subpart C [PSES for...

40 CFR 430.66 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... standards for existing sources (PSES) if it uses chlorophenolic-containing biocides. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides. PSES must be attained on or before July 1, 1984: Subpart F Pollutant or pollutant property PSES...

40 CFR 430.34 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... biocides are used must achieve the following effluent limitations representing the degree of effluent...-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart C [BAT effluent limitations for...

40 CFR 430.104 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... chlorophenolic-containing biocides are used must achieve the following effluent limitations representing the... applicable to non-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart J [BAT effluent...

40 CFR 430.64 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... biocides are used must achieve the following effluent limitations representing the degree of effluent...-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart F Pollutant or pollutant property BAT...

40 CFR 430.14 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... biocides are used must achieve the following effluent limitations representing the degree of effluent...-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart A [BAT effluent limitations] Pollutant...

40 CFR 430.44 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... biocides are used must achieve the following effluent limitations representing the degree of effluent...-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart D [BAT effluent limitations for...

40 CFR 430.94 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... chlorophenolic-containing biocides are used must achieve the following effluent limitations representing the... applicable to non-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these biocides: Subpart I [Facilities...

Analysis of metal and biocides resistance genes in drug resistance and susceptible Salmonella enterica from food animals

USDA-ARS?s Scientific Manuscript database

Background Generally drug resistant bacteria carry antibiotic resistance genes and heavy metal and biocide resistance genes on large conjugative plasmids. The presence of these metal and biocide resistance genes in susceptible bacteria are not assessed comprehensively. Hence, WGS data of susceptib...

Formulation of Biocides Increases Antimicrobial Potency and Mitigates the Enrichment of Nonsusceptible Bacteria in Multispecies Biofilms

PubMed Central

Forbes, Sarah; Cowley, Nicola; Mistry, Hitesh; Amézquita, Alejandro

2017-01-01

ABSTRACT The current investigation aimed to generate data to inform the development of risk assessments of biocide usage. Stabilized domestic drain biofilm microcosms were exposed daily over 6 months to increasing concentrations (0.01% to 1%) of the biocide benzalkonium chloride (BAC) in a simple aqueous solution (BAC-s) or in a complex formulation (BAC-f) representative of a domestic cleaning agent. Biofilms were analyzed by culture, differentiating by bacterial functional group and by BAC or antibiotic susceptibility. Bacterial isolates were identified by 16S rRNA sequencing, and changes in biofilm composition were assessed by high-throughput sequencing. Exposure to BAC-f resulted in significantly larger reductions in levels of viable bacteria than exposure to BAC-s, while bacterial diversity greatly decreased during exposure to both BAC-s and BAC-f, as evidenced by sequencing and viable counts. Increases in the abundance of bacteria exhibiting reduced antibiotic or BAC susceptibility following exposure to BAC at 0.1% were significantly greater for BAC-s than BAC-f. Bacteria with reduced BAC and antibiotic susceptibility were generally suppressed by higher BAC concentrations, and formulation significantly enhanced this effect. Significant decreases in the antimicrobial susceptibility of bacteria isolated from the systems before and after long-term BAC exposure were not detected. In summary, dose-dependent suppression of bacterial viability by BAC was enhanced by formulation. Biocide exposure decreased bacterial diversity and transiently enriched populations of organisms with lower antimicrobial susceptibility, and the effects were subsequently suppressed by exposure to 1% BAC-f, the concentration most closely reflecting deployment in formulated products. IMPORTANCE Assessment of the risks of biocide use has been based mainly on the exposure of axenic cultures of bacteria to biocides in simple aqueous solutions. The current investigation aimed to assess the effects of formulation on the outcome of biocide exposure in multispecies biofilms. Formulation of the cationic biocide BAC significantly increased antimicrobial potency. Bacteria with lower antimicrobial susceptibility whose populations were enriched after low-level biocide exposure were more effectively suppressed by the biocide at in-use concentrations (1% [wt/vol]) in a formulation than in a simple aqueous solution. These observations underline the importance of simulating normal deployment conditions in considering the risks and benefits of biocide use. PMID:28115386

Quaternary Ammonium Biocides: Efficacy in Application

PubMed Central

2014-01-01

Quaternary ammonium compounds (QACs) are among the most commonly used disinfectants. There has been concern that their widespread use will lead to the development of resistant organisms, and it has been suggested that limits should be place on their use. While increases in tolerance to QACs have been observed, there is no clear evidence to support the development of resistance to QACs. Since efflux pumps are believe to account for at least some of the increased tolerance found in bacteria, there has been concern that this will enhance the resistance of bacteria to certain antibiotics. QACs are membrane-active agents interacting with the cytoplasmic membrane of bacteria and lipids of viruses. The wide variety of chemical structures possible has seen an evolution in their effectiveness and expansion of applications over the last century, including non-lipid-containing viruses (i.e., noroviruses). Selection of formulations and methods of application have been shown to affect the efficacy of QACs. While numerous laboratory studies on the efficacy of QACs are available, relatively few studies have been conducted to assess their efficacy in practice. Better standardized tests for assessing and defining the differences between increases in tolerance versus resistance are needed. The ecological dynamics of microbial communities where QACs are a main line of defense against exposure to pathogens need to be better understood in terms of sublethal doses and antibiotic resistance. PMID:25362069

Temperate and virulent Lactobacillus delbrueckii bacteriophages: comparison of their thermal and chemical resistance.

PubMed

Ebrecht, Ana C; Guglielmotti, Daniela M; Tremmel, Gustavo; Reinheimer, Jorge A; Suárez, Viviana B

2010-06-01

The aim of this work was to study the efficiency of diverse chemical and thermal treatments usually used in dairy industries to control the number of virulent and temperate Lactobacillus delbrueckii bacteriophages. Two temperate (Cb1/204 and Cb1/342) and three virulent (BYM, YAB and Ib3) phages were studied. The thermal treatments applied were: 63 degrees C for 30 min (low temperature--long time, LTLT), 72 degrees C for 15 s (high temperature--short time, HTST), 82 degrees C for 5 min (milk destined to yogurt elaboration) and 90 degrees C for 15 min (FIL-IDF). The chemical agents studied were: sodium hypochlorite, ethanol, isopropanol, peracetic acid, biocides A (quaternary ammonium chloride), B (hydrogen peroxide, peracetic acid and peroctanoic acid), C (alkaline chloride foam), D (p-toluensulfonchloroamide, sodium salt) and E (ethoxylated nonylphenol and phosphoric acid). The kinetics of inactivation were drew and T(99) (time necessary to eliminate the 99% of phage particles) calculated. Results obtained showed that temperate phages revealed lower resistance than the virulent ones to the treatment temperatures. Biocides A, C, E and peracetic acid showed a notable efficiency to inactivate high concentrations of temperate and virulent L. delbrueckii phages. Biocide B evidenced, in general, a good capacity to eliminate the phage particles. Particularly for this biocide virulent phage Ib3 showed the highest resistance in comparison to the rest of temperate and virulent ones. On the contrary, biocide D and isopropanol presented a very low capacity to inactivate all phages studied. The efficiency of ethanol and hypochlorite was variable depending to the phages considered. These results allow a better knowledge and give useful information to outline more effective treatments to reduce the phage infections in dairy plants. 2009 Elsevier Ltd. All rights reserved.

Promising biocidal activity of thymol loaded chitosan silver nanoparticles (T-C@AgNPs) as anti-infective agents against perilous pathogens.

PubMed

Manukumar, H M; Umesha, S; Kumar, H N Naveen

2017-09-01

The advent of biodegradable polymer-encapsulated drug nanoparticles has made an exciting area of drug delivery research. The present study investigated novel and simple route for synthesis of thymol loaded chitosan silver nanoparticles (T-C@AgNPs) using chitosan and thymol as reducing, capping agent respectively to understand the therapeutic efficacy. The UV-vis spectroscopy, DLS, FT-IR, SEM, EDS, XRD used for characterization and radical scavenging activity, anti-microbial and biocompatibility was taken to ascertain an efficacy of novel T-C@AgNPs. The T-C@AgNPs intense peak at 490nm indicates the formation of nanoparticles and had average particle size of 28.94nm with spherical shape, monodisperse state in water, also exhibited excellent biocompatibility of cubic shaped pure silver element containing T-C@AgNPs. The antibacterial activity was studied for gram positive and gram negative food-borne pathogens and effective inhibition at 100μgmL -1 to S. aureus, S. epidermidis, S. haemolyticus (10.08, 10.00, 11.23mm) and S. typhimurium, P. aeruginosa and S. flexneri (9.28, 9.33, 12.03mm) compared to antibiotic Streptomycin. This study revealed the efficacy against multiple food-borne pathogens and therapeutic efficacy of T-C@AgNPs offers a valuable contribution in the area of nanotechnology. This proved to be a first-class novel antimicrobial material for the first time in this study. Copyright © 2017 Elsevier B.V. All rights reserved.

A Novel Anti-Influenza Copper Oxide Containing Respiratory Face Mask

PubMed Central

Borkow, Gadi; Zhou, Steve S.; Page, Tom; Gabbay, Jeffrey

2010-01-01

Background Protective respiratory face masks protect the nose and mouth of the wearer from vapor drops carrying viruses or other infectious pathogens. However, incorrect use and disposal may actually increase the risk of pathogen transmission, rather than reduce it, especially when masks are used by non-professionals such as the lay public. Copper oxide displays potent antiviral properties. A platform technology has been developed that permanently introduces copper oxide into polymeric materials, conferring them with potent biocidal properties. Methodology/Principal Findings We demonstrate that impregnation of copper oxide into respiratory protective face masks endows them with potent biocidal properties in addition to their inherent filtration properties. Both control and copper oxide impregnated masks filtered above 99.85% of aerosolized viruses when challenged with 5.66±0.51 and 6.17±0.37 log10TCID50 of human influenza A virus (H1N1) and avian influenza virus (H9N2), respectively, under simulated breathing conditions (28.3 L/min). Importantly, no infectious human influenza A viral titers were recovered from the copper oxide containing masks within 30 minutes (≤0.88 log10TCID50), while 4.67±1.35 log10TCID50 were recovered from the control masks. Similarly, the infectious avian influenza titers recovered from the copper oxide containing masks were ≤0.97±0.01 log10TCID50 and from the control masks 5.03±0.54 log10TCID50. The copper oxide containing masks successfully passed Bacterial Filtration Efficacy, Differential Pressure, Latex Particle Challenge, and Resistance to Penetration by Synthetic Blood tests designed to test the filtration properties of face masks in accordance with the European EN 14683:2005 and NIOSH N95 standards. Conclusions/Significance Impregnation of copper oxide into respiratory protective face masks endows them with potent anti-influenza biocidal properties without altering their physical barrier properties. The use of biocidal masks may significantly reduce the risk of hand or environmental contamination, and thereby subsequent infection, due to improper handling and disposal of the masks. PMID:20592763

Leaching of biocides used in façade coatings under laboratory test conditions.

PubMed

Schoknecht, Ute; Gruycheva, Jana; Mathies, Helena; Bergmann, Hannelore; Burkhardt, Michael

2009-12-15

The European Biocidal Products Directive 98/8/EC requires a risk assessment concerning possible effects of active ingredients on the environment. Biocides can be leached from treated materials exposed to outdoor use. These emissions have to be estimated and evaluated during the authorization procedure. Different immersion and irrigation tests were performed to investigate leaching of biocides from façade coatings. Several marketed formulations of textured coatings and paints spiked with a mixture of commonly used active ingredients (OIT, DCOIT, IPBC, carbendazim, isoproturon, diuron, terbutryn, and Irgarol 1051) were investigated. The emission process can be described by time-dependent functions that depend on the test conditions. The results of all test procedures confirm that leachability is related to water solubility and n-octanol-water partition coefficient of the active ingredients and that leaching of biocides from façade coatings is mainly a diffusion controlled process. Other factors like the composition of the product, availability and transport of water, concentration of active ingredients in the coatings, as well as UV-exposure of the coatings influence biocide emissions.

In vitro activity of glucosinolates and their degradation products against brassica-pathogenic bacteria and fungi.

PubMed

Sotelo, T; Lema, M; Soengas, P; Cartea, M E; Velasco, P

2015-01-01

Glucosinolates (GSLs) are secondary metabolites found in Brassica vegetables that confer on them resistance against pests and diseases. Both GSLs and glucosinolate hydrolysis products (GHPs) have shown positive effects in reducing soil pathogens. Information about their in vitro biocide effects is scarce, but previous studies have shown sinigrin GSLs and their associated allyl isothiocyanate (AITC) to be soil biocides. The objective of this work was to evaluate the biocide effects of 17 GSLs and GHPs and of leaf methanolic extracts of different GSL-enriched Brassica crops on suppressing in vitro growth of two bacterial (Xanthomonas campestris pv. campestris and Pseudomonas syringae pv. maculicola) and two fungal (Alternaria brassicae and Sclerotinia scletoriorum) Brassica pathogens. GSLs, GHPs, and methanolic leaf extracts inhibited the development of the pathogens tested compared to the control, and the effect was dose dependent. Furthermore, the biocide effects of the different compounds studied were dependent on the species and race of the pathogen. These results indicate that GSLs and their GHPs, as well as extracts of different Brassica species, have potential to inhibit pathogen growth and offer new opportunities to study the use of Brassica crops in biofumigation for the control of multiple diseases. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Silver biocide's real-world success.

PubMed

Pearson, Susan

2015-03-01

Although temperature control has been the UK's longest-serving means of controlling the growth and proliferation of Legionella in hot and cold water systems, there are other factors, including major rises in energy costs, that warrant the use of biocides--including in the healthcare sector. In 2000, the HSE's new 'L8' guidelines took this into account, giving equal weight to both temperature reg~mes and biocides, such as chlorine dioxide, as control methods. Susan Pearson BSc reports on one potentially effective biocide- silver hydrogen peroxide, explains how it 'works' in practice, and highlights the recent 'real-world' evidence of its effectiveness and advantages.

Glass-(nAg, nCu) biocide coatings on ceramic oxide substrates.

PubMed

Esteban-Tejeda, Leticia; Malpartida, Francisco; Díaz, Luis Antonio; Torrecillas, Ramón; Rojo, Fernando; Moya, José Serafín

2012-01-01

The present work was focused on obtaining biocide coatings constituted by a glassy soda-lime matrix containing silver or copper nanoparticles on ceramic (alumina and zirconia based) substrates. Both glassy coatings showed a high biocide activity against Gram-, Gram+ bacteria and yeast, reducing cell numbers more than three logarithms. Silver nanoparticles had a significantly higher biocide activity than copper nanoparticles, since the lixiviation levels required to reduce cell numbers more than 3 logarithms was of almost 1-2 µg/cm(2) in the case of silver nanoparticles, and 10-15 µg/cm(2) for the copper nanoparticles.

Occurrence of imidacloprid, carbendazim, and other biocides in Italian house dust: Potential relevance for intakes in children and pets.

PubMed

Salis, Severyn; Testa, Cecilia; Roncada, Paola; Armorini, Sara; Rubattu, Nicola; Ferrari, Angelo; Miniero, Roberto; Brambilla, Gianfranco

2017-09-02

The occurrence of pesticides intended for non-agricultural use was investigated in 206 dust samples drawn from vacuum-cleaner bags from residential flats in Italy. The multi-residue analysis targeted on 95 different active principles was performed with UPLC-MS/MS, with a Limit of Quantification (LOQ) of 0.008 μg/g dry weight. The results indicated the presence of imidacloprid (IMI) and carbendazim (CARB) in 30% and 26% of the samples, with a mean and P95 concentration between 1.6 and 39 and between 0.08 and 4.9 μg/g, respectively. Combined presence of two biocides was noted in 19.4% samples, of three biocides in 9.2% samples, of four biocides in 3.4% samples, and of five and six biocides in 0.5% and 1% samples, respectively. According to the estimated dust intake in infants/toddlers aged 6-24 months (16-100 mg d -1 ) and cats (200 mg d -1 ), it was possible to obtain risk characterization with respect to the Acceptable Daily Intake (ADI) for IMI of 0.060 mg/kg body weight (bw) proposed by the European Food Safety Authority (EFSA) and the chronic Population Adjusted Dose (cPAD) of 0.019 mg/kg bw d -1 by US-EPA. Under the worst-case scenario, the presence of IMI in dust indicates potential exceedance of the cPAD in kittens, to be considered as sentinel also accounting for combined exposure. This study highlights the relevance of consumer empowerment about the responsible use of pesticides as biocidal products in indoor environment.

2-(Decylthio)ethanamine hydrochloride: A new multifunctional biocide which enhances corrosion inhibition

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

Walter, R.W.; Cooke, L.M.

1997-12-01

2-(Decylthio)ethanamine hydrochloride is a new multifunctional biocide that is registered for use in a variety of recirculating cooling water systems. This biocide has broad spectrum activity against bacteria, fungi and algae. It also has biofilm and corrosion inhibition properties. Data on these various activities will be presented for both laboratory and field evaluations.

Quantitative comparison of the results obtained by the multiple-dose guinea pig maximization test and the non-radioactive murine local lymph-node assay for various biocides.

PubMed

Yamano, Tetsuo; Shimizu, Mitsuru; Noda, Tsutomu

2005-07-01

We compared the results of the multiple-dose guinea pig maximization test (GPMT) and the non-radioactive murine local lymph-node assay (LLNA) for various biocides. Thirteen out of 17 positive biocides in the GPMT gave positive results in the LLNA. In the GPMT, the minimum first induction doses ranged over four orders (0.00005-0.5%), while elicitation-threshold doses, which were evaluated using an optimally sensitized group of animals in the multiple-dose studies, ranged over five orders (0.00006-2.8%). In the LLNA, minimum induction doses ranged over more than three orders (0.01-30%). With respect to 13 biocides that were positive in both the GPMT and the LLNA, results were quantitatively compared. When compared after conversion to corresponding area doses (microg/cm), the minimum doses required to elicit skin reaction in guinea pigs were always lower than that for induction in mice with all biocides. Correlation between minimum induction doses from the GPMT and the LLNA seemed poor (r=0.57), while that between minimum induction doses in the LLNA and elicitation-threshold doses in the GPMT was relatively good (r=0.73). The results suggest the possibility to estimate human elicitation-threshold doses, which are definitely lacking in the process of risk assessment for skin-sensitizers, from the data of the LLNA.

Synthesis of novel benzodioxane midst piperazine moiety decorated chitosan silver nanoparticle against biohazard pathogens and as potential anti-inflammatory candidate: A molecular docking studies.

PubMed

Karthik, C S; Manukumar, H M; Ananda, A P; Nagashree, S; Rakesh, K P; Mallesha, L; Qin, Hua-Li; Umesha, S; Mallu, P; Krishnamurthy, N B

2018-03-01

Nanoparticles (NPs) are currently being investigated along with the use of biodegradable polymer containing active agents in many areas of medicine for targeted applications. The present study was aimed to synthesize novel compound Benzodioxane midst piperazine (BP) and characterization of a BP decorated chitosan silver nanoparticles (BP*C@AgNPs) and shown effective against hazardous pathogens, and also having anti-inflammatory property. It was further evaluated for molecular docking proofs, and toxicity. The BP*C@AgNPs had spherical shape with size of 36.6nm with wide biocidal activity against hazardous Gram-positive and Gram-negative bacteria with excellent inhibition at 100μg/mL for S. aureus (10.08±0.05mm ZOI), and E. coli (10.03±0.04mm ZOI) compared to antibiotic Streptomycin. The anti-inflammatory activity exhibited IC 50 value of 71.61±1.05μg/mL for BP*C@AgNPs compared to indomethacin (IC 50 =40.15±1.21μg/mL). Also, the docking study of BP showed excellent score for COX1 and DNA gyrase. This in silico study confirmed the achieved efficacy of BP, with less toxicity against normal PMBCs in vitro and in vivo studies. This study concludes that, the novel synthesized BP*C@AgNPs had excellent biocidal property and as anti-inflammatory candidate revealed by docking studies, it confirms BP*C@AgNPs for first-class therapeutic applications in the area of medicinal nanotechnology for the coming days. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis of D-glucosamine quaternary ammonium derivatives and evaluation of their antifungal activity together with aminodeoxyglucose derivatives against two wood fungi Coriolus versicolor and Poria placenta: structure-activity relationships.

PubMed

Muhizi, Théoneste; Coma, Véronique; Grelier, Stéphane

2011-03-01

Structure-activity relationships are often reported in scientific studies. These may be employed in searching for new acceptable biocides to use against harmful microorganisms, because the biocides used hitherto encounter various problems, including lack of efficiency, high toxicity and persistence. Nowadays, scientists are trying to find new, environmentally acceptable biocides to replace these earlier biocides. Different compounds from renewable materials have been studied and have shown pronounced antifungal activity against wood fungi. These include aminopolysaccharide derivatives and different quaternary ammonium polymers. A biological study carried out with these products indicated a possible relationship between amino groups and differences in biological activity observed. In this study, an amino group was successively fixed to different carbon atoms of glucose, and glucosamine was also modified by both N-alkylation and quaternisation. The impact of the amino group position on antifungal activity against two wood decay fungi was investigated. The amino group at the anomeric position showed the highest antifungal activity against both Coriolus versicolor Quel. and Poria placenta (Fr.) Cooke. Furthermore, the positive impact of both N-alkylation and quaternisation on the growth of both strains was demonstrated. The anomeric position of the amino group and the N-alkylation and quaternisation of amino sugars considerably increase the antifungal activity of these compounds. Copyright © 2010 Society of Chemical Industry.

Radiation-Resistant Hybrid Lotus Effect for Achieving Photoelectrocatalytic Self-Cleaning Anticontamination Coatings

NASA Technical Reports Server (NTRS)

Taylor, Edward W.; Pirich, Ronald G.

2011-01-01

An experiment involving radiation-resistant hydrophobic coatings is planned for space exposure and experimental testing on the International Space Station (ISS) in 2011. The Lotus biocide coatings are designed for supporting space exploration missions. This innovation is an antibacterial, anti-contamination, and self-cleaning coating that uses nano-sized semiconductor semimetal oxides to neutralize biological pathogens and toxic chemicals, as well as to mitigate dust accumulation (see figure). The Lotus biocide coating is thin (approximately microns thick), lightweight, and the biocide properties will not degrade with time or exposure to biological or chemical agents. The biocide is stimulated chemically (stoichiometric reaction) through exposure to light (photocatalysis), or by an applied electric field (electrocatalysis). The hydrophobic coating samples underwent preliminary high-energy proton and alpha-ray (helium ion) irradiations at the Lawrence Berkeley National Laboratory 88" cyclotron and demonstrated excellent radiation resistance for a portion of the Galactic Cosmic Ray (GRC) and Solar Proton spectrum. The samples will undergo additional post-flight studies when returned to Earth to affirm further the radiation resistance properties of the space exposed coatings.

Effects of five antifouling biocides on settlement and growth of zoospores from the marine macroalga Ulva lactuca L.

PubMed

Wendt, Ida; Arrhenius, Åsa; Backhaus, Thomas; Hilvarsson, Annelie; Holm, Kristina; Langford, Katherine; Tunovic, Timur; Blanck, Hans

2013-10-01

Antifouling biocides are found in the marine ecosystem were they can affect non-target organisms. In this study the effects of five antifouling biocides on the settlement and growth of Ulva lactuca zoospores were investigated. The biocides investigated were copper (Cu(2+)), 4,5-dichloro-2-n-octyl-3(2H)-isothiazolone (DCOIT), triphenylborane pyridine (TPBP), tolylfluanid and medetomidine. Full concentration-response curves where determined for each compound. EC50 values were determined for copper, DCOIT, TPBP and tolylfluanid, all of which inhibited settlement and growth in a concentration dependent manner with the following toxicity ranking; tolylfluanid (EC50 80 nmol L(-1)) ~ DCOIT (EC50 83 nmol L(-1)) > TPBP (EC50 400 nmol L(-1)) > Cu(2+) (EC50 2,000 nmol L(-1)). Medetomidine inhibited settlement and growth only at the extreme concentration of 100,000 nmol L(-1) (93% effect). The low toxicity is possibly a consequence of a lack of receptors that medetomidine can bind to in the U. lactuca zoospores.

Antimicrobial Materials for Advanced Microbial Control in Spacecraft Water Systems

NASA Technical Reports Server (NTRS)

Birmele, Michele; Caro, Janicce; Newsham, Gerard; Roberts, Michael; Morford, Megan; Wheeler, Ray

2012-01-01

Microbial detection, identification, and control are essential for the maintenance and preservation of spacecraft water systems. Requirements set by NASA put limitations on the energy, mass, materials, noise, cost, and crew time that can be devoted to microbial control. Efforts are being made to attain real-time detection and identification of microbial contamination in microgravity environments. Research for evaluating technologies for capability enhancement on-orbit is currently focused on the use of adenosine triphosphate (ATP) analysis for detection purposes and polymerase chain reaction (peR) for microbial identification. Additional research is being conducted on how to control for microbial contamination on a continual basis. Existing microbial control methods in spacecraft utilize iodine or ionic silver biocides, physical disinfection, and point-of-use sterilization filters. Although these methods are effective, they require re-dosing due to loss of efficacy, have low human toxicity thresholds, produce poor taste, and consume valuable mass and crew time. Thus, alternative methods for microbial control are needed. This project also explores ultraviolet light-emitting diodes (UV-LEDs), surface passivation methods for maintaining residual biocide levels, and several antimicrobial materials aimed at improving current microbial control techniques, as well as addressing other materials presently under analysis and future directions to be pursued.

Effects of single and repeated exposure to biocidal active substances on the barrier function of the skin in vitro.

PubMed

Buist, Harrie E; van de Sandt, Johannes J M; van Burgsteden, Johan A; de Heer, Cees

2005-10-01

The dermal route of exposure is important in worker exposure to biocidal products. Many biocidal active substances which are used on a daily basis may decrease the barrier function of the skin to a larger extent than current risk assessment practice addresses, due to possible skin effects of repeated exposure. The influence of repeated and single exposure to representative biocidal active substances on the skin barrier was investigated in vitro. The biocidal active substances selected were alkyldimethylbenzylammonium chloride (ADBAC), boric acid, deltamethrin, dimethyldidecylammonium chloride (DDAC), formaldehyde, permethrin, piperonyl butoxide, sodium bromide, and tebuconazole. Of these nine compounds, only the quaternary ammonium chlorides ADBAC and DDAC had a clear and consistent influence on skin permeability of the marker compounds tritiated water and [(14)C]propoxur. For these compounds, repeated exposure increased skin permeability more than single exposure. At high concentrations the difference between single and repeated exposure was quantitatively significant: repeated exposure to 300 mg/L ADBAC increased skin permeability two to threefold in comparison to single exposure. Therefore, single and repeated exposure to specific biocidal products may significantly increase skin permeability, especially when used undiluted.

Virulence factors and antimicrobial resistance in Escherichia coli strains isolated from hen egg shells.

PubMed

Grande Burgos, María José; Fernández Márquez, Maria Luisa; Pérez Pulido, Rubén; Gálvez, Antonio; Lucas López, Rosario

2016-12-05

Eggs may contain extraintestinal pathogenic (ExPEC) and diarrheogenic (DEC) Escherichia coli which in addition may carry antibiotic resistance. The wide use of biocides and disinfectants in the food industry may induce biocide tolerance in bacteria. The aim of the present study was to evaluate biocide tolerance and antibiotic resistance in E. coli from hen egg shells. A total of 27 isolates obtained from a screening of 180 eggs were studied. Seven isolates carried both eae and bfpA genes of typical enteropathogenic E. coli (EPEC) strains, while 14 isolates only carried eae associated with atypical EPEC strains. Shiga toxin genes stx and stx2 were detected in four isolates. Heat-stable and heat-labile enterotoxin genes as well as aggR were also detected. Several isolates had minimum inhibitory concentrations (MICs) that were higher than the wild-type for the biocide hexadecylpyridinium chloride (HDP, 18.52%) or the commercial disinfectant P3 oxonia (OX, 14.81%). Antibiotic resistance was detected for ampicillin (37.03%), streptomycin (37.03%), tetracycline (37.03%), chloramphenicol (11.11%), nalidixic acid (18.51%) and trimethoprim-sulfamethoxazole (14.81%). Eight isolates (29.63%) were biocide tolerant and antibiotic resistant. Efflux pump genes detected included acrB (96.29%), mdfA (85.18%) and oxqA (37.03%), in addition to quaternary ammonium compound (QAC) resistance genes qacA/B (11.11%) and qacE (7.40%). Antibiotic resistance genes detected included bla CTX-M-2 (22.22%), bla TEM (3.70%), bla PSE (3.70%), tet(A) (29.63%), tet(B) (29.63%), tet(C) (7.40%), tet(E) (11.11%), aac(6')-Ib (3.70%), sul1 (14.81%), dfrA12 (3.70%) and dfrA15 (3.70%). Most isolates (96.30%) carried more than one genetic determinant of resistance. The most frequent combinations were efflux pump components acrB and mdfA with tetracycline resistance genes (33.33% of isolates). Isolates carrying QAC resistance genes also carried between 4 and 8 of the additional antimicrobial resistance genes investigated. Regardless of biocide tolerance and antibiotic resistance, all isolates were sensitive to carvacrol (0.25%), thymol (0.125%) and trisodium phosphate (1 to 1.5%), but they exhibited a heterogeneous response to sodium lactate and lysozyme-EDTA combinations that apparently were not related with antibiotic resistance. Results from the study reveal not only a low incidence of biocide tolerance but also the presence of multiple resistance strains carrying multiple genetic determinants of resistance. Copyright © 2016 Elsevier B.V. All rights reserved.

Significant Differences Characterise the Correlation Coefficients between Biocide and Antibiotic Susceptibility Profiles in Staphylococcus aureus.

PubMed

Oggioni, Marco R; Coelho, Joana Rosado; Furi, Leonardo; Knight, Daniel R; Viti, Carlo; Orefici, Graziella; Martinez, Jose-Luis; Freitas, Ana Teresa; Coque, Teresa M; Morrissey, Ian

2015-01-01

There is a growing concern by regulatory authorities for the selection of antibiotic resistance caused by the use of biocidal products. We aimed to complete the detailed information on large surveys by investigating the relationship between biocide and antibiotic susceptibility profiles of a large number of Staphylococcus aureus isolates using four biocides and antibiotics commonly used in clinical practice. The minimal inhibitory concentration (MIC) for most clinically-relevant antibiotics was determined according to the standardized methodology for over 1600 clinical S. aureus isolates and compared to susceptibility profiles of benzalkonium chloride, chlorhexidine, triclosan, and sodium hypochlorite. The relationship between antibiotic and biocide susceptibility profiles was evaluated using non-linear correlations. The main outcome evidenced was an absence of any strong or moderate statistically significant correlation when susceptibilities of either triclosan or sodium hypochlorite were compared for any of the tested antibiotics. On the other hand, correlation coefficients for MICs of benzalkonium chloride and chlorhexidine were calculated above 0.4 for susceptibility to quinolones, beta-lactams, and also macrolides. Our data do not support any selective pressure for association between biocides and antibiotics resistance and furthermore do not allow for a defined risk evaluation for some of the compounds. Importantly, our data clearly indicate that there does not involve any risk of selection for antibiotic resistance for the compounds triclosan and sodium hypochlorite. These data hence infer that biocide selection for antibiotic resistance has had so far a less significant impact than feared.

Biocides in urban wastewater treatment plant influent at dry and wet weather: concentrations, mass flows and possible sources.

PubMed

Bollmann, Ulla E; Tang, Camilla; Eriksson, Eva; Jönsson, Karin; Vollertsen, Jes; Bester, Kai

2014-09-01

In recent years, exterior thermal insulation systems became more and more important leading to an increasing amount of houses equipped with biocide-containing organic façade coatings or fungicide treated wood. It is known that these biocides, e.g. terbutryn, carbendazim, and diuron, as well as wood preservatives as propiconazole, leach out of the material through contact with wind driven rain. Hence, they are present in combined sewage during rain events in concentrations up to several hundred ng L(-1). The present study focused on the occurrence of these biocides in five wastewater treatment plants in Denmark and Sweden during dry and wet weather. It was discovered, that biocides are detectable not only during wet weather but also during dry weather when leaching from façade coatings can be excluded as source. In most cases, the concentrations during dry weather were in the same range as during wet weather (up to 100 ng L(-1)); however, for propiconazole noteworthy high concentrations were detected in one catchment (4.5 μg L(-1)). Time resolved sampling (12 × 2 h) enabled assessments about possible sources. The highest mass loads during wet weather were detected when the rain was heaviest (e.g. up to 116 mg h(-1) carbendazim or 73 mg h(-1) mecoprop) supporting the hypothesis that the biocides were washed off by wind driven rain. Contrary, the biocide emissions during dry weather were rather related to household activities than with emissions from buildings, i.e., emissions were highest during morning and evening hours (up to 50 mg h(-1)). Emissions during night were significantly lower than during daytime. Only for propiconazole a different emission behaviour during dry weather was observed: the mass load peaked in the late afternoon (3 g h(-1)) and declined slowly afterwards. Most likely this emission was caused by a point source, possibly from inappropriate cleaning of spray equipment for agriculture or gardening. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

PubMed

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

2012-03-01

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

Concentration patterns of agricultural pesticides and urban biocides in surface waters of a catchment of mixed land use

NASA Astrophysics Data System (ADS)

Stamm, C.; Wittmer, I.; Bader, H.-P.; Scheidegger, R.; Alder, A.; Lück, A.; Hanke, I.; Singer, H.

2009-04-01

Organic pesticides and biocides that are found in surface waters, can originate from agricultural and urban sources. For a long time, agricultural pesticides have received substantially more attention than biocidal compounds from urban use like material protection or in-can preservatives (cosmetics etc.). Recent studies however revealed that the amounts of urban biocides used may exceed those of agricultural pesticides. This study aims at comparing the input of several important pesticides and biocides into a small Swiss stream with a special focus on loss events triggered by rainfall. A set of 16 substances was selected to represent urban and agricultural sources. The selected substances are either only used as biocides (irgarol, isothiazolinones, IPBC), as pesticides (atrazine, sulcotrione, dichlofluanid, tolylfluanid) or have a mixed use (isoproturon, terbutryn, terbutylazine, mecoprop, diazinon, carbendazim) The study catchment has an area of 25 km2 and is inhabited by about 12'000 people. Four sampling sites were selected in the river system in order to reflect different urban and agricultural sources. Additionally, we sampled a combined sewer overflow, a rain sewer and the outflow of a wastewater treatment plant. At each site discharge was measured continuously from March to November 2007. During 16 rain events samples were taken by automatic devices at a high temporal resolution. The results, based on more than 500 analyzed samples, revealed distinct concentration patterns for different compounds and sources. Agricultural pesticides exhibited a strong seasonality as expected based on the application periods. During the first one or two rain events after application the concentrations reached up to several thousand ng/l during peak flow (atrazine, isoproturon). The temporal patterns of urban biocides were more diverse. Some compounds obviously stem from permanent sources independent of rainfall because they were found mostly in the outlet of the wastewater treatment plant throughout the year. The insecticide diazinon for example showed a background concentration in treated waste water of approximately 50 ng/l. Substances like mecoprop, which are used in urban areas (roof protection, private gardens) and agriculture showed a mixed pattern. At the time scale of single events two concentration peaks have been observed. One of them was due to the fast reaction of sewer overflows or rain sewers carrying urban storm water. The delayed peak was caused by fast flow from agricultural soils. Overall, the study revealed complex concentration patterns for the different compounds. Source identification was only possible by means of a comprehensive approach including different nested measuring sites, a broad range of different compounds that were complemented by tracer substances like caffeine or drugs and their metabolites (sulfamethoxazole, N4-acetylsulfamethoxazole, diclofenac) that can be non-ambiguously attributed to sources like treated or untreated wastewater.

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

PubMed Central

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

2015-01-01

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

The effect of ozonated cooling water on the corrosion behavior of stainless steel, titanium and copper alloys. Ozone biocidal action on sessile and planktonic bacteria

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

Videla, H.A.; Guiamet, P.S.; Mele, M.F.L. de

1999-11-01

Two aspects of ozone utilization as sole chemical treatment for cooling water demand a better understanding: (a) the effect of dissolved ozone on the corrosion behavior of heat exchanger structural materials and (b) the biocidal action of ozone on bacterial biofilms. To assess the effect of ozone dissolved in synthetic cooling water on the corrosion behavior of different structural materials (stainless steel; 70:30 copper-nickel; aluminum brass and titanium), voltamperometric experiments and corrosion potential vs. time measurements were made at ozone concentrations between 0.1 and 1.2 ppm. Present results show that the passive behavior of stainless steel and titanium is notmore » affected by dissolved ozone whereas copper alloys are susceptible to corrosion in the presence of ozone. To study the biocidal action of various concentrations of dissolved ozone against planktonic and sessile bacteria, liquid cultures and biofilms of Pseudomonas fluorescense, formed on different structural materials, were used at different contact times. The results show that dissolved ozone is an effective biocide for controlling planktonic cells but its effectiveness decreases in the presence of sessile bacteria and the extracellular polymeric matrix of the biofilm. It is suggested that the penetration of ozone through the biofilm depends on the simultaneous diffusion and reaction of the biocide with the biofilm matrix which may exhibit local differences in biomass distribution and hydrodynamic conditions.« less

Enterococcus hirae biofilm formation on hospital material surfaces and effect of new biocides.

PubMed

Di Lodovico, Silvia; Cataldi, Valentina; Di Campli, Emanuela; Ancarani, Elisabetta; Cellini, Luigina; Di Giulio, Mara

2017-08-02

Nowadays, the bacterial contamination in the hospital environment is of particular concern because the hospital-acquired infections (HAIs), also known as nosocomial infections, are responsible for significant morbidity and mortality. This work evaluated the capability of Enterococcus hirae to form biofilm on different surfaces and the action of two biocides on the produced biofilms. The biofilm formation of E. hirae ATCC 10541 was studied on polystyrene and stainless steel surfaces through the biomass quantification and the cell viability at 20 and 37 °C. The effect of LH IDROXI FAST and LH ENZYCLEAN SPRAY biocides on biomasses was expressed as percentage of biofilm reduction. E. hirae at 20 and 37 °C produced more biofilm on the stainless steel in respect to the polystyrene surface. The amount of viable cells was greater at 20 °C than with 37 °C on the two analyzed surfaces. Biocides revealed a good anti-biofilm activity with the most effect for LH ENZYCLEAN SPRAY on polystyrene and stainless steel at 37 °C with a maximum biofilm reduction of 85.72 and 86.37%, respectively. E. hirae is a moderate biofilm producer depending on surface material and temperature, and the analyzed biocides express a remarkable antibiofilm action. The capability of E. hirae to form biofilm can be associated with its increasing incidence in hospital-acquired infections, and the adoption of suitable disinfectants is strongly recommended.

Alkyl ammonium cation stabilized biocidal polyiodides with adaptable high density and low pressure.

PubMed

He, Chunlin; Parrish, Damon A; Shreeve, Jean'ne M

2014-05-26

The effective application of biocidal species requires building the active moiety into a molecular back bone that can be delivered and decomposed on demand under conditions of low pressure and prolonged high-temperature detonation. The goal is to destroy storage facilities and their contents while utilizing the biocidal products arising from the released energy to destroy any remaining harmful airborne agents. Decomposition of carefully selected iodine-rich compounds can produce large amounts of the very active biocides, hydroiodic acid (HI) and iodine (I2). Polyiodide anions, namely, I3(-), I5(-), which are excellent sources of such biocides, can be stabilized through interactions with large, symmetric cations, such as alkyl ammonium salts. We have designed and synthesized suitable compounds of adaptable high density up to 3.33 g cm(-3) that are low-pressure polyiodides with various alkyl ammonium cations, deliverable iodine contents of which range between 58.0-90.9%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Does microbial resistance to biocides create a hazard to food hygiene?

PubMed

Meyer, Bernhard

2006-12-01

Numerous reports are available on microbial resistance to antibiotics as well as to biocides. Instances of cross-resistance between these substance groups have been reported. Resistance, which is a genetically determined phenomenon, has to be distinguished from phenotypic adaptation processes, which are not hereditary. Adaptation can be avoided by rigorous cleaning and disinfection, avoiding concentrations of disinfectants below the microbicidal concentration. Resistance phenomena have to be divided into intrinsic and acquired resistance. Intrinsic resistance is the naturally greater resistance of certain microbial species compared to others. The term acquired resistance is used if certain strains of a microbial species differ significantly in their susceptibility to biocides compared to the average of this species. An overview of existing reports of resistance to different biocidal substances is given. In most of these reports, resistance is defined as an elevated minimum inhibitory concentration. The relevance of these data for disinfection processes, where microbicidal concentrations are applied, is discussed. Rotational use of different types of disinfectants, to avoid development of resistance, has been discussed controversially. Because of the unspecific mechanism of action of biocides, and the lack of scientific evidence for its need, rotational use of disinfectants is not recommended. In conclusion the risk of hazards in food production and processing caused by resistance to biocides is regarded as low.

Extent of fungal growth on fiberglass duct liners with and without biocides under challenging environmental conditions.

PubMed

Samimi, Behzad S; Ross, Kristen

2003-03-01

Eight brands of fiberglass duct liners, including three that contained biocides, were exposed to challenging environmental conditions that would promote fungal growth. Twenty-four rectangular sheet metal ducts in three groups of eight ducts per group were lined with the eight selected liners. Each group of ducts was exposed to one of the three test conditions within an environmental chamber for a period of 15 days. These conditions were a) 75 percent RH, b) 75 percent RH plus water spray, c) 75 percent RH plus dry nutrient, and d) 75 percent RH plus water plus nutrient. Viable spores of Aspergillus niger were aerosolized into each duct as seed. On the 16th day, air and surface samples for fungal spores were collected from inside ducts. The results of air sampling using N6 sampler and visual inspection indicated that two out of three biocide-containing liners, Permacote and Toughgard, inhibited fungal growth but only under condition A. The third biocide-containing liner, Aeroflex Plus, was effective even when it was wet (conditions A and B). All three biocide-containing liners failed to inhibit fungal growth under conditions C and D. Among the five other types of liners that did not contain biocides, ATCO Flex with a smooth Mylar coating was more preferable, exhibiting lower fungal activity during conditions A, B, and C. All liners failed under condition D when nutrient and water were added together. Surface sampling using adhesive tape failed to produce representative results, apparently due to rough/porous surface of duct liners. It was concluded that duct liners with biocide treatment could be less promoting to microbial growth under high humidity as long as their surfaces remain clean and water-free. A liner with an impermeable and smooth surface seems to be less subject to microbial growth under most conditions than biocide-containing liners having porous and/or rough surfaces.

Biocidal Properties of Anti-Icing Additives for Aircraft Fuels

PubMed Central

Neihof, R. A.; Bailey, C. A.

1978-01-01

The biocidal and biostatic activities of seven glycol monoalkyl ether compounds were evaluated as part of an effort to find an improved anti-icing additive for jet aircraft fuel. Typical fuel contaminants, Cladosporium resinae, Gliomastix sp., Candida sp., Pseudomonas aeruginosa, and a mixed culture containing sulfate-reducing bacteria were used as assay organisms. Studies were carried out over 3 to 4 months in two-phase systems containing jet fuel and aqueous media. Diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and 2-methoxyethanol were generally biocidal in aqueous concentrations of 10 to 17% for all organisms except Gliomastix, which required 25% or more. 2-Ethoxyethanol, 2-propoxyethanol, and 2-butoxyethanol were biocidal at progressively lower concentrations down to 1 to 2% for 2-butoxyethanol. The enhanced antimicrobial activity of these three compounds was attributed to cytoplasmic membrane damage because of the correlation between surface tension measurements and lytic activity with P. aeruginosa cells. The mechanism of action of the less active compounds appeared to be due to osmotic (dehydrating) effects. When all requirements are taken into account, diethylene glycol monomethyl ether appears to be the most promising replacement for the currently used additive, 2-methoxyethanol. PMID:646356

Desorption of biocides from renders modified with acrylate and silicone.

PubMed

Styszko, Katarzyna; Bollmann, Ulla E; Wangler, Timothy P; Bester, Kai

2014-01-01

Biocides are used in the building industry to prevent algal, bacterial and fungal growth on polymericrenders and thus to protect buildings. However, these biocides are leached into the environment. To better understand this leaching, the sorption/desorption of biocides in polymeric renders was assessed. In this study the desorption constants of cybutryn, carbendazim, iodocarb, isoproturon, diuron, dichloro-N-octylisothiazolinone and tebuconazole towards acrylate and silicone based renders were assessed at different pH values. At pH 9.5 (porewater) the constants for an acrylate based render varied between 8 (isoproturon) and 9634 (iodocarb) and 3750 (dichloro-N-octylisothiazolinone), respectively. The values changed drastically with pH value. The results for the silicone based renders were in a similar range and usually the compounds with high sorption constants for one polymer also had high values for the other polymer. Comparison of the octanol water partitioning constants (Kow) with the render/water partitioning constants (Kd) revealed similarities, but no strong correlation. Adding higher amounts of polymer to the render material changed the equilibria for dichloro-N-octylisothiazolinone, tebuconazole, cybutryn, carbendazim but not for isoproturon and diuron. Copyright © 2013 Elsevier Ltd. All rights reserved.

Quality of alcohol-based hand disinfectants and their regulatory status. Development and marketing authorisation.

PubMed

Stengele, Michael

2008-10-01

A 2005 survey showed that there are at least four legal product classifications for hand disinfectants in the European Union: medicinal products, biocidal products, cosmetics and medical devices. An internationally harmonized classification does not exist. The regulatory status of those products is defined at national level. In order to assure compliance with the regulations these four classifications provide different levels of official surveillance varying from product-specific marketing authorisations and production site audits to the obligation to just work in accordance with certain general guidelines. Biocidal product regulations cover eco-toxicological and toxicological aspects, but do not very much address to the customers' quality and efficacy expectations. In contrast, the medicinal product legislation is the most ambitious one claiming quality, safety, efficacy, and an independent benefit risk-assessment by an authority. In respect of ambition, the two remaining product categories--cosmetics and medical devices--rank between the both classifications mentioned above. For medical devices, it is the responsibility of the manufacturer to make sure the products meet defined essential requirements regarding quality, safety and performance and to have an appropriate quality assurance system implemented under third party control. For cosmetics there are some legal restrictions, but within these it is the sole responsibility of the manufacturer to ensure that the products are safe and fulfil their claims. This paper describes one way out of this increasingly complex situation, the definition of a single quality standard meeting the users' expectations as well as all legal requirements regardless of the specific sales country. This international quality standard for products would take priority over any individual national standard, to the benefit of users.

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

PubMed Central

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

2015-01-01

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

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

PubMed

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

2015-01-01

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

Toward Tailor-Made Biocide Materials Based on Poly(propylene)/Copper Nanoparticles.

PubMed

Palza, Humberto; Gutiérrez, Sebastian; Delgado, Katherine; Salazar, Oriana; Fuenzalida, Victor; Avila, Jonathan I; Figueroa, Guillermo; Quijada, Raúl

2010-03-16

A set of poly(propylene) composites containing different amounts of copper nanoparticles (CNP) were prepared by the melt mixed method and their antimicrobial behavior was quantitatively studied. The time needed to reduce the bacteria to 50% dropped to half with only 1 v/v % of CNP, compared to the polymer without CNP. After 4 h, this composite killed more than 99.9% of the bacteria. The biocide kinetics can be controlled by the nanofiller content; composites with CNP concentrations higher than 10 v/v % eliminated 99% of the bacteria in less than 2 h. X-ray photoelectron spectroscopy did not detect CNP at the surface, therefore the biocide behavior was attributed to copper in the bulk of the composite. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Case study: Use of isothiazolinone and nitro-morpholine biocides to control microbial contamination in diesel and gasoline storage and distribution systems

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

Chesneau, H.L.; Passman, F.J.; Daniels, D.

1995-05-01

Responding to feed-back from its retail outlet network, a major, vertically integrated petroleum company undertook to diagnose and remediate diesel and gasoline performance problems. Analysis of samples from tanks at refinery, distribution terminal and retail outlet sites established that uncontrolled microbial contamination was rampant throughout the distribution system. The company then developed and instituted a two-phase action plan. During Phase I, all tanks received corrective (shock) biocide treatment preceding mechanical tank cleaning and fuel polishing. An ongoing Phase II program currently includes routine sampling and analysis combined with periodic preventive biocide treatment. This paper describes the initial problem diagnosis, correctivemore » action plan and preventive program; recommending the Phase II program as a model for all companies involved with refining, distribution or retailing gasoline.« less

Contact allergy to preservatives: ESSCA* results with the baseline series, 2009-2012.

PubMed

Giménez-Arnau, A M; Deza, G; Bauer, A; Johnston, G A; Mahler, V; Schuttelaar, M-L; Sanchez-Perez, J; Silvestre, J F; Wilkinson, M; Uter, W

2017-04-01

Allergic contact dermatitis caused by biocides is common and causes significant patient morbidity. To describe the current frequency and pattern of patch test reactivity to biocide allergens included in the baseline series of most European countries. Data collected by the European Surveillance System on Contact Allergies (ESSCA) network between 2009 and 2012 from 12 European countries were analysed. Methylisothiazolinone 0.2% aq. produced the highest prevalence of sensitization during the study period, with an overall prevalence of 4.5%. The mixture methylchloroisothiazolinone /methylisothiazolinone tested at 0.02% aq. followed closely, with 4.1% of positive reactions. Other preservatives with lower rates of sensitization, but still over 1%, include methyldibromo glutaronitrile (MDBGN) 0.5% pet. and iodopropynyl butylcarbamate (IPBC) 0.2% pet. Formaldehyde releasers and parabens yielded less than 1% positive reactions during the study period. Some regional differences in the prevalence of contact allergy to biocides among European countries were observed. Contact allergy to biocides is common throughout Europe, and regional differences could be explained by differences in exposure or characteristics of the population tested. Timely regulatory action for isothiazolinones is required. Although MDBGN is banned from cosmetics products since 2005, sensitization prevalence has not appeared to plateau. IPBC is an emerging allergen with an increasing prevalence over the last few years, and its inclusion in the European baseline series may be appropriate. © 2016 European Academy of Dermatology and Venereology.

Phenotypic changes contributing to Enterobacter gergoviae biocide resistance.

PubMed

Périamé, M; Philippe, N; Condell, O; Fanning, S; Pagès, J-M; Davin-Regli, A

2015-08-01

Enterobacter gergoviae is a recurrent contaminant of cosmetic and hygiene products. To understand how this bacterium adapts to biocides, we studied Ent. gergoviae CIP 76.01 and its triclosan and Methylisothiazolinone-chloromethylisothiazolinone (MIT-CMIT) tolerant isogenic mutants. They were compared with others also isolated from contaminated cosmetics. Phenotypic differences were noted and these included changes in the bacterial envelope and flagella along with differences in motility, and biofilm growth rates. Triclosan and MIT-CMIT derivatives expressed flagella and other MIT-CMIT derivatives exhibited some external appendages. Those bacteria expressing a high-level minimal inhibitory concentration to MIT-CMIT, expressed a strong biofilm formation. No differential phenotypes were noted for carbon source utilisation. Enterobacter gergoviae demonstrated a diverse response to both of these preservatives contained in cosmetic preparations, depending on their concentrations. Interestingly, this adaptive response is associated with modifications of filament structure-related proteins contributing to increase the organism motility and the production of biofilm. Recurrent contaminations of cosmetics products by Ent. gergoviae, needed a better understanding concerning the bacterial adaptation to preservative agents, with particular concern to triclosan and MIT-CMIT. We demonstrated that bacteria response is associated to various mechanisms represented by expression of external appendages (pili or fimbriae) that control cell motility and biofilm formation and evolving as the concentration of biocides adaptation increased. Such mechanisms which are not chemical specific can also promote a cross-resistance to other biocidal agents. The characterization of Ent. gergoviae adaptability to biocides allows industry to adjust the ranges of concentrations and composition of preservatives in formula. © 2015 The Society for Applied Microbiology.

Effects of three oxidizing biocides on Legionella pneumophila serogroup 1.

PubMed Central

Domingue, E L; Tyndall, R L; Mayberry, W R; Pancorbo, O C

1988-01-01

A study was conducted to determine the bactericidal effects of ozone and hydrogen peroxide relative to that of free chlorine on Legionella pneumophila serogroup 1. In laboratory batch-type experiments, organisms seeded at various densities were exposed to different concentrations of these biocides in demand-free buffers. Bactericidal effects were measured by determining the ability of L. pneumophila to grow on buffered charcoal-yeast extract agar supplemented with alpha-ketoglutarate. Ozone was the most potent of the three biocides, with a greater than 99% kill of L. pneumophila occurring during a 5-min exposure to 0.10 to 0.30 micrograms of O3 per ml. The bactericidal action of O3 was not markedly affected by changes in pH or temperature. Concentrations of 0.30 and 0.40 micrograms of free chlorine per ml killed 99% of the L. pneumophila after 30- and 5-min exposures, respectively. A 30-min exposure to 1,000 micrograms of H2O2 per ml was required to effect a 99% reduction of the viable L. pneumophila population. However, no viable L. pneumophila could be detected after a 24-h exposure to 100 or 300 micrograms of H2O2 per ml. Attempts were made to correlate the biocidal effects of O3 and H2O2 with the oxidation of L. pneumophila fatty acids. These tests indicated that certain biocidal concentrations of O3 and H2O2 resulted in a loss or severe reduction of L. pneumophila unsaturated fatty acids. PMID:3377492

Development of antimicrobial active packaging materials based on gluten proteins.

PubMed

Gómez-Heincke, Diana; Martínez, Inmaculada; Partal, Pedro; Guerrero, Antonio; Gallegos, Críspulo

2016-08-01

The incorporation of natural biocide agents into protein-based bioplastics, a source of biodegradable polymeric materials, manufactured by a thermo-mechanical method is a way to contribute to a sustainable food packaging industry. This study assesses the antimicrobial activity of 10 different biocides incorporated into wheat gluten-based bioplastics. The effect that formulation, processing, and further thermal treatments exert on the thermo-mechanical properties, water absorption characteristics and rheological behaviour of these materials is also studied. Bioplastics containing six of the 10 examined bioactive agents have demonstrated suitable antimicrobial activity at 37 °C after their incorporation into the bioplastic. Moreover, the essential oils are able to create an antimicrobial atmosphere within a Petri dish. Depending on the selected biocide, its addition may alter the bioplastics protein network in a different extent, which leads to materials exhibiting less water uptake and different rheological and thermo-mechanical behaviours. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

The application of bioactive compounds from the food industry to control mold growth in indoor waterborne coatings.

PubMed

Bellotti, N; Salvatore, L; Deyá, C; Del Panno, M T; del Amo, B; Romagnoli, R

2013-04-01

Microbial growth in indoor environments creates health problems, especially in people with asthma; approximately 80% of these patients are allergic to mold. Antimicrobial coatings are formulated to generate surfaces that are easy to clean and may also incorporate active agents, commonly called biocides, which inhibit microbial colonization, subsequent growth and bio-deterioration of the substrates. Some research lines seek to replace traditional organometallic and organochlorines biocides with environmentally acceptable ones. The aim of this research was, primarily, to explore the possible application of different compounds used in food industry like preservatives to be used as antimicrobial additives for antimicrobial coatings. Four biocides were tested against two different ambient molds isolated from an interior painted wall (Chaetomium globosum and Alternaria alternate). The selected biocides were zinc salicylate, zinc benzoate, calcium benzoate and potassium sorbate. The resulting paints were subjected to biological and physical tests (viscosity, hiding power, humidity absorption and biocides leaching rate). Bioassays revealed that zinc benzoate and zinc salicylate resulted active against both fungi. Copyright © 2012 Elsevier B.V. All rights reserved.

Crew Exploration Vehicle (CEV) Potable Water System Verification Description

NASA Technical Reports Server (NTRS)

Peterson, Laurie; DeVera, Jean; Vega, Leticia; Adam, Nik; Steele, John; Rector, Tony; Gazda, Daniel; Roberts, Michael

2008-01-01

The Crew Exploration Vehicle (CEV), also known as Orion, will ferry a crew of up to six astronauts to the International Space Station (ISS), or a crew of up to four astronauts to the moon. The first launch of CEV is scheduled for approximately 2014. A stored water system on the CEV will supply the crew with potable water for various purposes: drinking and food rehydration, hygiene, medical needs, sublimation, and various contingency situations. The current baseline biocide for the stored water system is ionic silver, similar in composition to the biocide used to maintain quality of the water transferred from the Orbiter to the ISS and stored in Contingency Water Containers (CWCs). In the CEV water system, the ionic silver biocide is expected to be depleted from solution due to ionic silver plating onto the surfaces of the materials within the CEV water system, thus negating its effectiveness as a biocide. Since the biocide depletion is expected to occur within a short amount of time after loading the water into the CEV water tanks at the Kennedy Space Center (KSC), an additional microbial

Biocides: Capturing bugs and bigger markets

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

Hairston, D.W.

1995-10-01

Deep in the dark interior of cooling water towers, intake streams and purifiers, there is a jungle. Hundreds of thousands of microorganisms dwell in algae and biofilm, breeding mutant and increasingly resistant strains of bacteria. For biocide manufacturers, the imperative is to find better ways to control the proliferation of the microscopic bugs. Some of the most robust demand for biocides is in the cooling water market, particularly as industrial water treatment continues to switch from gaseous chlorine to bromine compounds. The trend toward closed-loop and faster cycles for process water treatment will require more biological control. Biocides are expectedmore » to benefit from that trend, but in pulp and paper operations, chlorine dioxide may reap the biggest gains. Also making inroads is an electrolytic system that uses ClO{sub 2} to control microorganisms in cooling towers. Despite growing demand for safe and more-effective biocides in Europe and the US, new product development is stymied by the rigorous and costly process of getting regulatory approval. In the US, EPA registration can cost $5--10 million and take 5 to 10 years.« less

The Potential of Antimicrobial Peptides as Biocides

PubMed Central

Laverty, Garry; Gorman, Sean P.; Gilmore, Brendan F.

2011-01-01

Antimicrobial peptides constitute a diverse class of naturally occurring antimicrobial molecules which have activity against a wide range of pathogenic microorganisms. Antimicrobial peptides are exciting leads in the development of novel biocidal agents at a time when classical antibiotics are under intense pressure from emerging resistance, and the global industry in antibiotic research and development stagnates. This review will examine the potential of antimicrobial peptides, both natural and synthetic, as novel biocidal agents in the battle against multi-drug resistant pathogen infections. PMID:22072905

Micro-Biocidal Activity of Yeast Cells by Needle Plasma Irradiation at Atmospheric Pressure

NASA Astrophysics Data System (ADS)

Kurumi, Satoshi; Takahashi, Hideyuki; Taima, Tomohito; Suzuki, Kaoru; Hirose, Hideharu; Masutani, Shigeyuki

In this study, we report on the biocidal activity technique by needle helium plasma irradiation at atmospheric pressure using borosilicate capillary nozzle to apply for the oral surgery. The diameter of needle plasma was less than 50 µm, and temperature of plasma irradiated area was less than body temperature. Needle plasma showed emission due to OH and O radical. Raman spectra and methylene blue stain showed yeast cells were inactivated by needle plasma irradiation.

Incorporation of the zosteric sodium salt in silica nanocapsules: synthesis and characterization of new fillers for antifouling coatings

NASA Astrophysics Data System (ADS)

Ruggiero, Ludovica; Crociani, Laura; Zendri, Elisabetta; El Habra, Naida; Guerriero, Paolo

2018-05-01

In the last decade many commercial biocides were gradually banned for toxicity. This work reports, for the first time, the synthesis and characterization of silica nanocontainers loaded with a natural product antifoulant (NPA), the zosteric sodium salt which is a non-commercial and environmentally friendly product with natural origin. The synthesis approach is a single step dynamic self-assembly with tetraethoxysilane (TEOS) as silica precursor. Unlike conventional mesoporous silica nanoparticles, the structure of these silica nanocontainers provides loading capacity and allows prolonged release of biocide species. The obtained nanocapsules have been characterized morphologically by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The encapsulation was checked by FTIR ATR spectroscopy and thermogravimetric analyses. The results of the release studies show the great potential of the here presented newly developed nanofillers in all applications where a controlled release of non-toxic and environmentally friendly biocides is required.

Research and development of an electrochemical biocide reactor

NASA Technical Reports Server (NTRS)

See, G. G.; Bodo, C. A.; Glennon, J. P.

1975-01-01

An alternate disinfecting process to chemical agents, heat, or radiation in an aqueous media has been studied. The process is called an electrochemical biocide and employs cyclic, low-level voltages at chemically inert electrodes to pass alternating current through water and, in the process, to destroy microorganisms. The paper describes experimental hardware, methodology, and results with a tracer microorganism (Escherichia coli). The results presented show the effects on microorganism kill of operating parameters, including current density (15 to 55 mA/sq cm (14 to 51 ASF)), waveform of applied electrical signal (square, triangular, sine), frequency of applied electrical signal (0.5 to 1.5 Hz), process water flow rate (100 to 600 cc/min (1.6 to 9.5 gph)), and reactor resident time (0 to 4 min). Comparisons are made between the disinfecting property of the electrochemical biocide and chlorine, bromine, and iodine.

Antifouling processes and toxicity effects of antifouling paints on marine environment. A review.

PubMed

Amara, Intissar; Miled, Wafa; Slama, Rihab Ben; Ladhari, Neji

2018-01-01

The production infrastructure in aquaculture invariably is a complex assortment of submerged components with cages, nets, floats and ropes. Cages are generally made from polyamide or high density polyethylene (PEHD). All of these structures serve as surfaces for biofouling. However, cage nets and supporting infrastructure offer fouling organisms thousands of square meters of multifilament netting. That's why, before immersing them in seawater, they should be coated with an antifouling agent. It helps to prevent net occlusion and to increase its lifespan. Biofouling in marine aquaculture is a specific problem and has three main negative effects. It causes net occlusion and so restricts water and oxygen exchange. Besides, the low dissolved oxygen levels from poor water exchange increases the stress levels of fish, lowers immunity and increases vulnerability to disease. Also, the extra weight imposed by fouling causes cage deformation and structural fatigue. The maintenance and loss of equipment cause the increase of production costs for the industry. Biocides are chemical substances that can prohibit or kill microorganisms responsible for biofouling. The expansion of the aquaculture industry requires the use of more drugs, disinfectants and antifoulant compounds (biocides) to eliminate the microorganisms in the aquaculture facilities. Unfortunately, the use of biocides in the aquatic environment has proved to be harmful as it has toxic effects on the marine environment. The most commonly used biocides in antifouling paints are Tributyltin (TBT), Chlorothalonil, Dichlofluanid, Sea-Nine 211, Diuron, Irgarol 1051 and Zinc Pyrithione. Restrictions were imposed on the use of TBT, that's why organic booster biocides were recently introduced. The replacement products are generally based on copper metal oxides and organic biocides. This paper provides an overview of the effects of antifouling biocides on aquatic organisms. It will focus on the eight booster biocides in common use, despite little data are available for some of them. Toxicity values and effects of these antifoulants will also be mentioned for different species of fish, crustaceans, invertebrates and algae. Copyright © 2017 Elsevier B.V. All rights reserved.

Leaching of biocides from façades under natural weather conditions.

PubMed

Burkhardt, M; Zuleeg, S; Vonbank, R; Bester, K; Carmeliet, J; Boller, M; Wangler, T

2012-05-15

Biocides are included in organic building façade coatings as protection against biological attack by algae and fungi but have the potential to enter the environment via leaching into runoff from wind driven rain. The following field study correlates wind driven rain to runoff and measured the release of several commonly used organic biocides (terbutryn, Irgarol 1051, diuron, isoproturon, OIT, DCOIT) in organic façade coatings from four coating systems. During one year of exposure of a west oriented model house façade in the Zurich, Switzerland area, an average of 62.7 L/m(2), or 6.3% of annual precipitation came off the four façade panels installed as runoff. The ISO method for calculating wind driven rain loads is adapted to predict runoff and can be used in the calculation of emissions in the field. Biocide concentrations tend to be higher in the early lifetime of the coatings and then reach fairly consistent levels later, generally ranging on the order of mg/L or hundreds of μg/L. On the basis of the amount remaining in the film after exposure, the occurrence of transformation products, and the calculated amounts in the leachate, degradation plays a significant role in the overall mass balance.

Reduction of healthcare-associated infections in a long-term care brain injury ward by replacing regular linens with biocidal copper oxide impregnated linens.

PubMed

Lazary, A; Weinberg, I; Vatine, J-J; Jefidoff, A; Bardenstein, R; Borkow, G; Ohana, N

2014-07-01

Contaminated textiles in hospitals contribute to endogenous, indirect-contact, and aerosol transmission of nosocomial related pathogens. Copper oxide impregnated linens have wide-spectrum antimicrobial, antifungal, and antiviral properties. Our aim was to determine if replacing non-biocidal linens with biocidal copper oxide impregnated linens would reduce the rates of healthcare-associated infections (HAI) in a long-term care ward. We compared the rates of HAI in two analogous patient cohorts in a head injury care ward over two 6-month parallel periods before (period A) and after (period B) replacing all the regular non-biocidal linens and personnel uniforms with copper oxide impregnated biocidal products. During period B, in comparison to period A, there was a 24% reduction in the HAI per 1000 hospitalization-days (p<0.05), a 47% reduction in the number of fever days (>38.5°C) per 1000 hospitalization-days (p<0.01), and a 32.8% reduction in total number of days of antibiotic administration per 1000 hospitalization-days (p<0.0001). Accordingly there was saving of approximately 27% in costs of antibiotics, HAI-related treatments, X-rays, disposables, labor, and laundry, expenses during period B. The use of biocidal copper oxide impregnated textiles in a long-term care ward may significantly reduce HAI, fever, antibiotic consumption, and related treatment costs. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Ozonation of Common Textile Auxiliaries

NASA Astrophysics Data System (ADS)

Iskender, Gulen; Arslan-Alaton, Idil; Koyunluoglu, Sebnem; Yilmaz, Zeynep; Germirli Babuna, Fatos

2016-10-01

The treatability of four different commonly applied textile auxiliary chemicals, namely two tannin formulations (Tannin 1: a condensation product of aryl sulphonate; Tannin 2: natural tannic acid) and two biocidal finishing agents (Biocide 1: 2,4,4’-trichloro-2’- hydroxydiphenyl ether; Biocide 2: a nonionic diphenyl alkane derivative) with ozone was investigated. Increasing the ozone dose yielded higher COD removals for the natural tannin. Optimum ozone doses of 485 and 662 mg/h were obtained at a pH of 3.5 for natural and synthetic tannin carrying textile bath discharges, respectively. When the reaction pH was increased from 3.5 to 7.0, a slight decrease in COD removal was observed for the natural tannin due to ozone selectivity towards its polyaromatic structure. The same increase in ozonation pH enhanced COD removals for the synthetic tannin as a result of enhanced ozone decomposition rendering free radical chain reactions dominant. Optimum ozone doses of 499 and 563 mg/h were established for Biocide 1 and 2, respectively. With the increase of ozonation, pH exhibited a positive influence on COD removals for both textile tannins. A substantial improvement in terms of TOC removals was observed as the reaction pH was increased from 3.5 to 7.0 for the synthetic tannin, and from 7 to 12 for both textile biocides. Higher AOX removals were evident at pH 7 than at pH 12 for Biocide 1 as a result of the higher selectivity of the dehalogenation reaction at neutral pH.

Controlled release for crop and wood protection: Recent progress toward sustainable and safe nanostructured biocidal systems.

PubMed

Mattos, Bruno D; Tardy, Blaise L; Magalhães, Washington L E; Rojas, Orlando J

2017-09-28

We review biocide delivery systems (BDS), which are designed to deter or control harmful organisms that damage agricultural crops, forests and forest products. This is a timely topic, given the growing socio-economical concerns that have motivated major developments in sustainable BDS. Associated designs aim at improving or replacing traditional systems, which often consist of biocides with extreme behavior as far as their solubility in water. This includes those that compromise or pollute soil and water (highly soluble or volatile biocides) or those that present low bioavailability (poorly soluble biocides). Major breakthroughs are sought to mitigate or eliminate consequential environmental and health impacts in agriculture and silviculture. Here, we consider the most important BDS vehicles or carriers, their synthesis, the environmental impact of their constituents and interactions with the active components together with the factors that affect their rates of release such as environmental factors and interaction of BDS with the crops or forest products. We put in perspective the state-of-the-art nanostructured carriers for controlled release, which need to address many of the challenges that exist in the application of BDS. Copyright © 2017 Elsevier B.V. All rights reserved.

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

PubMed

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

2012-05-01

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

Increased Usage of Antiseptics Is Associated with Reduced Susceptibility in Clinical Isolates of Staphylococcus aureus.

PubMed

Hardy, Katherine; Sunnucks, Katie; Gil, Hannah; Shabir, Sahida; Trampari, Eleftheria; Hawkey, Peter; Webber, Mark

2018-05-29

Hospital-acquired infection is a major cause of morbidity and mortality, and regimes to prevent infection are crucial in infection control. These include the decolonization of vulnerable patients with methicillin-resistant Staphylococcus aureus (MRSA) carriage using antiseptics, including chlorhexidine and octenidine. Concern has been raised, however, regarding the possible development of biocide resistance. In this study, we assembled a panel of S. aureus isolates, including isolates collected before the development of chlorhexidine and octenidine and isolates, from a major hospital trust in the United Kingdom during a period when the decolonization regimes were altered. We observed significant increases in the MIC and minimum bactericidal concentration (MBC) of chlorhexidine in isolates from periods of high usage of chlorhexidine. Isolates with increased MICs and MBCs of octenidine rapidly emerged after octenidine was introduced in the trust. There was no apparent cross-resistance between the two biocidal agents. A combination of variable-number tandem repeat (VNTR) analysis, PCR for qac genes, and whole-genome sequencing was used to type isolates and examine possible mechanisms of resistance. There was no expansion of a single strain associated with decreased biocide tolerance, and biocide susceptibility did not correlate with carriage of qac efflux pump genes. Mutations within the NorA or NorB efflux pumps, previously associated with chlorhexidine export, were identified, however, suggesting that this may be an important mechanism of biocide tolerance. We present evidence that isolates are evolving in the face of biocide challenge in patients and that changes in decolonization regimes are reflected in changes in susceptibility of isolates. IMPORTANCE Infection in hospitals remains a major cause of death and disease. One way in which we combat this is by decolonizing at-risk patients from carriage of bacteria which can cause disease such as MRSA. This is done with antiseptics, including chlorhexidine and octenidine. There is concern, however, that bacteria may be able to become resistant to these antiseptics. In this study, we looked at isolates of MRSA and found that there was a correlation between the use of antiseptics and increased resistance in the isolates. We also suggest that the mechanism by which these more tolerant isolates may become resistant to antiseptics is that of changing a transport pump that exports these agents. This information suggests that we need to study the impact of antiseptics on clinically important bacteria more closely. Copyright © 2018 Hardy et al.

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

PubMed

Wieck, Stefanie; Olsson, Oliver; Kümmerer, Klaus

2018-06-01

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

Control of Microbial Sulfide Production with Biocides and Nitrate in Oil Reservoir Simulating Bioreactors

PubMed Central

Xue, Yuan; Voordouw, Gerrit

2015-01-01

Oil reservoir souring by the microbial reduction of sulfate to sulfide is unwanted, because it enhances corrosion of metal infrastructure used for oil production and processing. Reservoir souring can be prevented or remediated by the injection of nitrate or biocides, although injection of biocides into reservoirs is not commonly done. Whether combined application of these agents may give synergistic reservoir souring control is unknown. In order to address this we have used up-flow sand-packed bioreactors injected with 2 mM sulfate and volatile fatty acids (VFA, 3 mM each of acetate, propionate and butyrate) at a flow rate of 3 or 6 pore volumes (PV) per day. Pulsed injection of the biocides glutaraldehyde (Glut), benzalkonium chloride (BAC) and cocodiamine was used to control souring. Souring control was determined as the recovery time (RT) needed to re-establish an aqueous sulfide concentration of 0.8–1 mM (of the 1.7–2 mM before the pulse). Pulses were either for a long time (120 h) at low concentration (long-low) or for a short time (1 h) at high concentration (short-high). The short-high strategy gave better souring control with Glut, whereas the long-low strategy was better with cocodiamine. Continuous injection of 2 mM nitrate alone was not effective, because 3 mM VFA can fully reduce both 2 mM nitrate to nitrite and N2 and, subsequently, 2 mM sulfate to sulfide. No synergy was observed for short-high pulsed biocides and continuously injected nitrate. However, use of continuous nitrate and long-low pulsed biocide gave synergistic souring control with BAC and Glut, as indicated by increased RTs in the presence, as compared to the absence of nitrate. Increased production of nitrite, which increases the effectiveness of souring control by biocides, is the most likely cause for this synergy. PMID:26696994

Crew Exploration Vehicle (CEV) Potable Water System Verification Description

NASA Technical Reports Server (NTRS)

Peterson, Laurie; DeVera, Jean; Vega, Leticia; Adam, Nik; Steele, John; Gazda, Daniel; Roberts, Michael

2009-01-01

The Crew Exploration Vehicle (CEV), also known as Orion, will ferry a crew of up to six astronauts to the International Space Station (ISS), or a crew of up to four astronauts to the moon. The first launch of CEV is scheduled for approximately 2014. A stored water system on the CEV will supply the crew with potable water for various purposes: drinking and food rehydration, hygiene, medical needs, sublimation, and various contingency situations. The current baseline biocide for the stored water system is ionic silver, similar in composition to the biocide used to maintain quality of the water transferred from the Orbiter to the ISS and stored in Contingency Water Containers (CWCs). In the CEV water system, the ionic silver biocide is expected to be depleted from solution due to ionic silver plating onto the surfaces of the materials within the CEV water system, thus negating its effectiveness as a biocide. Since the biocide depletion is expected to occur within a short amount of time after loading the water into the CEV water tanks at the Kennedy Space Center (KSC), an additional microbial control is a 0.1 micron point of use filter that will be used at the outlet of the Potable Water Dispenser (PWD). Because this may be the first time NASA is considering a stored water system for longterm missions that does not maintain a residual biocide, a team of experts in materials compatibility, biofilms and point of use filters, surface treatment and coatings, and biocides has been created to pinpoint concerns and perform testing to help alleviate those concerns related to the CEV water system. Results from the test plans laid out in the paper presented to SAE last year (Crew Exploration Vehicle (CEV) Potable Water System Verification Coordination, 2008012083) will be detailed in this paper. Additionally, recommendations for the CEV verification will be described for risk mitigation in meeting the physicochemical and microbiological requirements on the CEV PWS.

Evolution in the Lab: Biocide Resistance in E.coli.

ERIC Educational Resources Information Center

Welden, Charles W.; Hossler, Rex A.

2003-01-01

Describes a laboratory experiment on resistance to teach about evolution and issues of misuse of antimicrobial compounds. Investigates Escherichia coli's response to treatment of triclosan, a biocide used in consumer products. (Contains 12 references.) (YDS)

BioCIDER: a Contextualisation InDEx for biological Resources discovery

PubMed Central

Horro, Carlos; Cook, Martin; Attwood, Teresa K.; Brazas, Michelle D.; Hancock, John M.; Palagi, Patricia; Corpas, Manuel; Jimenez, Rafael

2017-01-01

Abstract Summary The vast, uncoordinated proliferation of bioinformatics resources (databases, software tools, training materials etc.) makes it difficult for users to find them. To facilitate their discovery, various services are being developed to collect such resources into registries. We have developed BioCIDER, which, rather like online shopping ‘recommendations’, provides a contextualization index to help identify biological resources relevant to the content of the sites in which it is embedded. Availability and Implementation BioCIDER (www.biocider.org) is an open-source platform. Documentation is available online (https://goo.gl/Klc51G), and source code is freely available via GitHub (https://github.com/BioCIDER). The BioJS widget that enables websites to embed contextualization is available from the BioJS registry (http://biojs.io/). All code is released under an MIT licence. Contact carlos.horro@earlham.ac.uk or rafael.jimenez@elixir-europe.org or manuel@repositive.io PMID:28407033

Biofilms in vitro and in vivo: do singular mechanisms imply cross-resistance?

PubMed

Gilbert, P; Allison, D G; McBain, A J

2002-01-01

Microbial biofilm has become inexorably linked with man's failure to control them by antibiotic and biocide regimes that are effective against suspended bacteria. This failure relates to a localized concentration of biofilm bacteria, and their extracellular products (exopolymers and extracellular enzymes), that moderates the access of the treatment agent and starves the more deeply placed cells. Biofilms, therefore, typically present gradients of physiology and concentration for the imposed treatment agent, which enables the less susceptible clones to survive. Such clones might include efflux mutants in addition to genotypes with modifications in single gene products. Clonal expansion following subeffective treatment would, in the case of many antibiotics, lead to the emergence of a resistant population. This tends not to occur for biocidal treatments where the active agent exhibits multiple pharmacological activity towards a number of specific cellular targets. Whilst resistance development towards biocidal agents is highly unlikely, subeffective exposure will lead to the selection of less susceptible clones, modified either in efflux or in their most susceptible target. The latter might also confer resistance to antibiotics where the target is shared. Thus, recent reports have demonstrated that sublethal concentrations of the antibacterial and antifungal agent triclosan can select for resistant mutants in Escherichia coli and that this agent specifically targets the enzyme enoyl reductase that is involved in lipid biosynthesis. Triclosan may, therefore, select for mutants in a target that is shared with the anti-E. coli diazaborine compounds and the antituberculosis drug isoniazid. Although triclosan may be a uniquely specific biocide, sublethal concentrations of less specific antimicrobial agents may also select for mutations within their most sensitive targets, some of which might be common to therapeutic agents. Sublethal treatment with chemical antimicrobial agents has also been demonstrated to induce the expression of multidrug efflux pumps and efflux mutants. Whilst efflux does not confer protection against use concentrations of biocidal products it is sufficient to confer protection against therapeutic doses of many antibiotics. It has, therefore, been widely speculated that biocide misuse may have an insidious effect, contributing to the evolution and persistence of drug resistance within microbial communities. Whilst such notions are supported by laboratory studies that utilize pure cultures, recent evidence has strongly refuted such linkage within the general environment where complex, multispecies biofilms predominate and where biocidal products are routinely deployed. In such situations the competition, for nutrients and space, between community members of disparate sensitivities far outweighs any potential benefits bestowed by the changes in an individual's antimicrobial susceptibility.

Study of the activity of quaternary ammonium compounds in the mitigation of biofouling in heat exchangers-condensers cooled by seawater.

PubMed

Trueba, Alfredo; Otero, Félix M; González, José A; Vega, Luis M; García, Sergio

2013-01-01

The effectiveness of two quaternary ammonium compounds (QACs) (non-oxidising biocides) to reduce the growth of biofilm adhering to the tubes of a heat exchanger-condenser cooled by seawater was evaluated. Their effectiveness was compared to that of a conventional oxidising biocide (sodium hypochlorite [NaOCl]) under the same testing conditions. Each biocide was applied intermittently (6 h on, 6 h off) in a first shock stage (1.5 ppm over 8 days) and a second stabilising stage (0.5 ppm over 20 days). The results showed that the antifouling effectiveness of the first of the QACs (fifth generation) was comparable to that shown by the oxidising power of NaOCl. Although the reaction time was longer than that of NaOCl, both the compounds removed the biofilm, and the tube was practically restored to its clean condition. Treatment with the second of the QACs (fourth generation) allowed for the stabilisation of biofilm growth, but not for its removal. Ecotoxicology studies classified the QACs as environmentally harmless under the testing conditions.

Environmentally friendly procedure based on VA-MSPD for the determination of booster biocides in fish tissue.

PubMed

Vieira, Augusto A; Caldas, Sergiane S; Escarrone, Ana Laura Venquiaruti; Arias, Jean Lucas de Oliveira; Primel, Ednei Gilberto

2018-03-01

Booster biocides have been widely applied to ships and other submerged structures. These compounds can be released into the marine environment as the result of vessel hull leaching and may remain in different environmental compartments. This study aimed at introducing an environmentally friendly procedure for the extraction of irgarol and diuron from fish samples by vortex-assisted matrix solid phase dispersion (VA-MSPD) with detection by liquid chromatography tandem mass spectrometry. Different types of solid supports and solvents were evaluated. The best results were found when 0.5g mussel shell, 0.5g sodium sulfate and 5mL ethanol were used. Analytical recoveries ranged from 81 to 110%, with RSD below 10%, whereas the matrix effect was between -17 and 1% (for all samples under study). LOQ values of irgarol and diuron were 5 and 50ngg -1 , respectively. The method under investigation proved to be a promising alternative to controlling contamination of fish by booster biocides, with low consumption of biodegradable reagents. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relationship of Triamine-Biocide Tolerance of Salmonella enterica Serovar Senftenberg to Antimicrobial Susceptibility, Serum Resistance and Outer Membrane Proteins.

PubMed

Futoma-Kołoch, Bożena; Dudek, Bartłomiej; Kapczyńska, Katarzyna; Krzyżewska, Eva; Wańczyk, Martyna; Korzekwa, Kamila; Rybka, Jacek; Klausa, Elżbieta; Bugla-Płoskońska, Gabriela

2017-07-11

A new emerging phenomenon is the association between the incorrect use of biocides in the process of disinfection in farms and the emergence of cross-resistance in Salmonella populations. Adaptation of the microorganisms to the sub-inhibitory concentrations of the disinfectants is not clear, but may result in an increase of sensitivity or resistance to antibiotics, depending on the biocide used and the challenged Salmonella serovar. Exposure of five Salmonella enterica subsp. enterica serovar Senftenberg ( S. Senftenberg) strains to triamine-containing disinfectant did not result in variants with resistance to antibiotics, but has changed their susceptibility to normal human serum (NHS). Three biocide variants developed reduced sensitivity to NHS in comparison to the sensitive parental strains, while two isolates lost their resistance to serum. For S. Senftenberg, which exhibited the highest triamine tolerance (6 × MIC) and intrinsic sensitivity to 22.5% and 45% NHS, a downregulation of flagellin and enolase has been demonstrated, which might suggest a lower adhesion and virulence of the bacteria. This is the first report demonstrating the influence of biocide tolerance on NHS resistance. In conclusion, there was a potential in S. Senftenberg to adjust to the conditions, where the biocide containing triamine was present. However, the adaptation did not result in the increase of antibiotic resistance, but manifested in changes within outer membrane proteins' patterns. The strategy of bacterial membrane proteins' analysis provides an opportunity to adjust the ways of infection treatments, especially when it is connected to the life-threating bacteremia caused by Salmonella species.

Relationship of Triamine-Biocide Tolerance of Salmonella enterica Serovar Senftenberg to Antimicrobial Susceptibility, Serum Resistance and Outer Membrane Proteins

PubMed Central

Futoma-Kołoch, Bożena; Dudek, Bartłomiej; Kapczyńska, Katarzyna; Wańczyk, Martyna; Korzekwa, Kamila; Rybka, Jacek; Klausa, Elżbieta; Bugla-Płoskońska, Gabriela

2017-01-01

A new emerging phenomenon is the association between the incorrect use of biocides in the process of disinfection in farms and the emergence of cross-resistance in Salmonella populations. Adaptation of the microorganisms to the sub-inhibitory concentrations of the disinfectants is not clear, but may result in an increase of sensitivity or resistance to antibiotics, depending on the biocide used and the challenged Salmonella serovar. Exposure of five Salmonella enterica subsp. enterica serovar Senftenberg (S. Senftenberg) strains to triamine-containing disinfectant did not result in variants with resistance to antibiotics, but has changed their susceptibility to normal human serum (NHS). Three biocide variants developed reduced sensitivity to NHS in comparison to the sensitive parental strains, while two isolates lost their resistance to serum. For S. Senftenberg, which exhibited the highest triamine tolerance (6 × MIC) and intrinsic sensitivity to 22.5% and 45% NHS, a downregulation of flagellin and enolase has been demonstrated, which might suggest a lower adhesion and virulence of the bacteria. This is the first report demonstrating the influence of biocide tolerance on NHS resistance. In conclusion, there was a potential in S. Senftenberg to adjust to the conditions, where the biocide containing triamine was present. However, the adaptation did not result in the increase of antibiotic resistance, but manifested in changes within outer membrane proteins’ patterns. The strategy of bacterial membrane proteins’ analysis provides an opportunity to adjust the ways of infection treatments, especially when it is connected to the life-threating bacteremia caused by Salmonella species. PMID:28696348

Bacteria survival probability in bactericidal filter paper.

PubMed

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.

Micronized Copper Wood Preservatives: Efficacy of Ion, Nano, and Bulk Copper against the Brown Rot Fungus Rhodonia placenta

PubMed Central

Civardi, Chiara; Schubert, Mark; Fey, Angelika; Wick, Peter; Schwarze, Francis W. M. R.

2015-01-01

Recently introduced micronized copper (MC) formulations, consisting of a nanosized fraction of basic copper (Cu) carbonate (CuCO3·Cu(OH)2) nanoparticles (NPs), were introduced to the market for wood protection. Cu NPs may presumably be more effective against wood-destroying fungi than bulk or ionic Cu compounds. In particular, Cu- tolerant wood-destroying fungi may not recognize NPs, which may penetrate into fungal cell walls and membranes and exert their impact. The objective of this study was to assess if MC wood preservative formulations have a superior efficacy against Cu-tolerant wood-destroying fungi due to nano effects than conventional Cu biocides. After screening a range of wood-destroying fungi for their resistance to Cu, we investigated fungal growth of the Cu-tolerant fungus Rhodonia placenta in solid and liquid media and on wood treated with MC azole (MCA). In liquid cultures we evaluated the fungal response to ion, nano and bulk Cu distinguishing the ionic and particle effects by means of the Cu2+ chelator ammonium tetrathiomolybdate (TTM) and measuring fungal biomass, oxalic acid production and laccase activity of R. placenta. Our results do not support the presence of particular nano effects of MCA against R. placenta that would account for an increased antifungal efficacy, but provide evidence that attribute the main effectiveness of MCA to azoles. PMID:26554706

Micronized Copper Wood Preservatives: Efficacy of Ion, Nano, and Bulk Copper against the Brown Rot Fungus Rhodonia placenta.

PubMed

Civardi, Chiara; Schubert, Mark; Fey, Angelika; Wick, Peter; Schwarze, Francis W M R

2015-01-01

Recently introduced micronized copper (MC) formulations, consisting of a nanosized fraction of basic copper (Cu) carbonate (CuCO3·Cu(OH)2) nanoparticles (NPs), were introduced to the market for wood protection. Cu NPs may presumably be more effective against wood-destroying fungi than bulk or ionic Cu compounds. In particular, Cu- tolerant wood-destroying fungi may not recognize NPs, which may penetrate into fungal cell walls and membranes and exert their impact. The objective of this study was to assess if MC wood preservative formulations have a superior efficacy against Cu-tolerant wood-destroying fungi due to nano effects than conventional Cu biocides. After screening a range of wood-destroying fungi for their resistance to Cu, we investigated fungal growth of the Cu-tolerant fungus Rhodonia placenta in solid and liquid media and on wood treated with MC azole (MCA). In liquid cultures we evaluated the fungal response to ion, nano and bulk Cu distinguishing the ionic and particle effects by means of the Cu2+ chelator ammonium tetrathiomolybdate (TTM) and measuring fungal biomass, oxalic acid production and laccase activity of R. placenta. Our results do not support the presence of particular nano effects of MCA against R. placenta that would account for an increased antifungal efficacy, but provide evidence that attribute the main effectiveness of MCA to azoles.

A Novel Cyclophilin B Gene in the Red Tide Dinoflagellate Cochlodinium polykrikoides: Molecular Characterizations and Transcriptional Responses to Environmental Stresses.

PubMed

Abassi, Sofia; Wang, Hui; Park, Bum Soo; Park, Jong-Woo; Ki, Jang-Seu

2017-01-01

The marine dinoflagellate Cochlodinium polykrikoides is one of the most common ichthyotoxic species that causes harmful algal blooms (HABs), which leads to ecological damage and huge economic loss in aquaculture industries. Cyclophilins (CYPs) belong to the immunophilin superfamily, and they may play a role in the survival mechanisms of the dinoflagellate in stress environments. In the present study, we identified a novel cyclophilin gene from C. polykrikoides and examined physiological and gene transcriptional responses to biocides copper sulphate (CuSO 4 ) and sodium hypochlorite (NaOCl). The full length of CpCYP was 903 bp, ranging from the dinoflagellate splice leader (DinoSL) sequence to the polyA tail, comprising a 639 bp ORF, a 117 bp 5'-UTR, and a 147 bp 3'-UTR. Motif and phylogenetic comparisons showed that CpCYP was affiliated to group B of CYP. In biocide stressors, cell counts, chlorophyll a , and photosynthetic efficiency ( Fv / Fm ) of C. polykrikoides were considerably decreased in both exposure time- and dose-dependent manners. In addition, CpCYP gene expression was significantly induced after 24 h exposure to the biocide-treated stress conditions. These results indicate an effect of the biocides on the cell physiology and expression profile of CpCYP , suggesting that the gene may play a role in environmental stress responses.

Promising silicones modified with cationic biocides for the development of antimicrobial medical devices.

PubMed

Ghamrawi, Sarah; Bouchara, Jean-Philippe; Tarasyuk, Oksana; Rogalsky, Sergiy; Lyoshina, Lyudmila; Bulko, Olga; Bardeau, Jean-François

2017-06-01

We have tested silicones containing 2% or 5% of the cationic biocides polyhexamethylene guanidine dodecylbenzenesulfonate (PHMG-DBS), 1-octyl-3-methylimidazolium tetrafluoroborate (OMIM-BF 4 ) or 1-dodecyl-3-methylimidazolium tetrafluoroborate (DMIM-BF 4 ) against the major relevant bacterial and yeast species in health care-associated infections (HCAI). Study conducted according to the international standard ISO 22196 revealed that silicones containing 2% or 5% DMIM-BF 4 or 5% PHMG-DBS presented the highest antimicrobial activity, leading to a logarithmic growth reduction of 3.03 to 6.46 and 3.65 to 4.85 depending on the bacterial or fungal species. Heat-pretreated silicones containing 2% DMIM-BF 4 kept a high activity, with at least a 3-log reduction in bacterial growth, except against P. aeruginosa where there was only a 1.1-log reduction. After 33days, the release ratio of cationic biocide from silicone films containing 5% of DMIM-BF 4 was found to be 5.6% in pure water and 1.9% in physiological saline solution, respectively. No leaching of PHMG-DBS polymeric biocide was detected under the same conditions. These results demonstrate unambiguously that silicones containing 2% DMIM-BF 4 or 5% PHMG-DBS present high antimicrobial activity, as well as high leaching resistance and therefore may be good candidates for the development of safer medical devices. Copyright © 2017 Elsevier B.V. All rights reserved.

Nanosilver Biocidal Properties and Their Application in Disinfection of Hatchers in Poultry Processing Plants

PubMed Central

Banach, Marcin; Tymczyna, Leszek; Chmielowiec-Korzeniowska, Anna; Pulit-Prociak, Jolanta

2016-01-01

The aim of this study was to use aqueous suspensions of silver nanoparticles with a wide spectrum of particle sizes, variable morphology, high stability, and appropriate physicochemical properties to examine their bactericidal and fungicidal properties against microorganisms present in poultry processing plants. At the same time, the particles were tested for preventing the production of odorogenous pollutants during incubation and thereby reducing the emission of harmful gases from such types of facilities. The results show that the use of nanosilver preparations in order to disinfect eggs and hatchers reduced microbiological contamination. The bactericidal and fungicidal efficacy of the applied preparation was comparable to UV radiation and its effectiveness increasing during the incubation. Good results were achieved in terms of the level of organic gaseous contaminants, which decreased by 86% after the application of the nanosilver preparation. PMID:26903785

40 CFR 430.15 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

..., concentration limitations (mg/l) shall apply, where provided. Concentration limitations will only apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must...

40 CFR 430.95 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

...-continuous dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration... biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not...

40 CFR 430.105 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

...-continuous dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration... biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not...

40 CFR 430.75 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

...-continuous dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration... are only applicable at facilities where chlorophenolic-containing biocides are used. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not...

40 CFR 430.75 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

...-continuous dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration... are only applicable at facilities where chlorophenolic-containing biocides are used. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not...

40 CFR 430.95 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

...-continuous dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration... biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not...

40 CFR 430.105 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

...-continuous dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration... biocides are used shall be subject to pentachlorophenol and trichlorophenol limitations. Permittees not using chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not...

Bactericidal activity of glutaraldehyde-like compounds from olive products.

PubMed

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.

40 CFR 430.65 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration limitations will only apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these...

40 CFR 430.15 - New source performance standards (NSPS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration limitations will only apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these...

40 CFR 430.45 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration limitations will only apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these...

40 CFR 430.65 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration limitations will only apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these...

40 CFR 430.15 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration limitations will only apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these...

40 CFR 430.15 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration limitations will only apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these...

40 CFR 430.35 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration limitations will only apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these...

40 CFR 430.45 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration limitations will only apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these...

40 CFR 430.35 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... dischargers, concentration limitations (mg/l) shall apply, where provided. Concentration limitations will only apply to non-continuous dischargers. Only facilities where chlorophenolic-containing biocides are used... chlorophenolic-containing biocides must certify to the permit-issuing authority that they are not using these...

THE BIOCIDE TRIBUTYLTIN ALTERS TESTOSTERONE ESTERIFICATION IN MUD SNAILS (ILYANASSA OBSOLETA)

EPA Science Inventory

The Biocide Tributyltin Alters Testosterone Esterification in Mud Snails (Ilyanassa obsoleta)

Meredith P. Gooding and Gerald A. LeBlanc
Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, NC 27695-7633

Tributyltin (TBT...

Potential development of a new cotton-based antimicrobial wipe

USDA-ARS?s Scientific Manuscript database

The adsorption of a cationic biocide on various cotton and synthetic nonwoven fabrics was investigated using UV-Vis absorption spectroscopy. The results reveal that rayon and greige cotton nonwovens adsorb nearly three times more cationic biocide than comparable bleached cotton substrates. Polyester...

Fluorescence microscopy techniques for quantitative evaluation of organic biocide distribution in antifouling paint coatings: application to model antifouling coatings.

PubMed

Goodes, L R; Dennington, S P; Schuppe, H; Wharton, J A; Bakker, M; Klijnstra, J W; Stokes, K R

2012-01-01

A test matrix of antifouling (AF) coatings including pMMA, an erodible binder and a novel trityl copolymer incorporating Cu₂O and a furan derivative (FD) natural product, were subjected to pontoon immersion and accelerated rotor tests. Fluorescence and optical microscopy techniques were applied to these coatings for quantification of organic biocide and pigment distribution. Total leaching of the biocide from the novel copolymer binder was observed within 6 months of rotor immersion, compared to 35% from the pMMA coating. In pontoon immersions, 61% of the additive was lost from the pMMA coating, and 53% from the erodible binder. Profiles of FD content in the binders revealed an accelerated loss of additive from the surface of the CDP resulting from rosin degradation, compared to even depletion from pMMA. In all samples, release of the biocide was inhibited beyond the Cu₂O front, corresponding to the leached layer in samples where Cu₂O release occurred.

Electrochemical Disinfection Feasibility Assessment Materials Evaluation for the International Space Station

NASA Technical Reports Server (NTRS)

Rodriquez, Branelle; Shindo, David; Montgomery, Eliza

2013-01-01

The International Space Station (ISS) Program recognizes the risk of microbial contamination in their potable and non-potable water sources. The end of the Space Shuttle Program limited the ability to send up shock kits of biocides in the event of an outbreak. Currently, the United States Orbital Segment water system relies primarily on iodine to mitigate contamination concerns, which has been successful in remediating the small cases of contamination documented. However, a secondary method of disinfection is a necessary investment for future space flight. Over the past year, NASA Johnson Space Center has investigated the development of electrochemically generated systems for use on the ISS. These systems include: hydrogen peroxide, ozone, sodium hypochlorite, and peracetic acid. To use these biocides on deployed water systems, NASA must understand of the effect these biocides have on current ISS materials prior to proceeding forward with possible on-orbit applications. This paper will discuss the material testing that was conducted to assess the effects of the biocides on current ISS materials.

Biogenic nanosilica blended by nanofibrillated cellulose as support for slow-release of tebuconazole

NASA Astrophysics Data System (ADS)

Mattos, Bruno D.; Magalhães, Washington L. E.

2016-09-01

Despite the potential application of nanotechnology in the agricultural sector, it is not as competitive as other industrial sectors because these approaches do not demonstrate a sufficient economic return to counterbalance the high production costs. For biocidal purposes, the reduction of the initial costs can be addressed if biogenic nanosilica and nanofibrillated cellulose were used to prepare nanocomposite for further utilization as support for slow-release of tebuconazole. Infrared spectroscopy and thermogravimetric analysis revealed that biocide was entrapped in the cellulose/silica nanocomposites network. The scanning electron microscopy and X-ray microtomography evaluation showed the nanocomposite's microstructure based on irregular shape nanosilica blended by nanofibrillated cellulose in a randomly organized network. Elemental mapping images showed the tebuconazole better dispersed in the composite blended with lower content of cellulose. The nanofibrillated cellulose played an important role in the release rate of the biocide mainly at short-term periods. At 15 days of immersion, the pure biocide had 95 % release compared with 30-45 % release of the tebuconazole loaded in the nanocomposites.

Comparing the biocidal properties of non-thermal plasma sources by reference protocol

NASA Astrophysics Data System (ADS)

Khun, Josef; Jirešová, Jana; Kujalová, Lucie; Hozák, Pavel; Scholtz, Vladimír

2017-10-01

The previously proposed reference protocol enabling easy comparison of biocidal properties of different non-thermal plasma sources has been followed and discussed. For inactivation tests the reference protocol has used spores of Gram positive bacterium Bacillus subtilis (ATCC 6633) deposited on a polycarbonate membrane as reference sample. In this work, biocidal properties of a negative glow corona, positive streamer corona, positive transient spark and cometary discharges are being compared in both open air and closed apparatus. Despite the total number of bacteria surviving 1 h exposure has decreased by up to 7 orders in closed apparatus, in open one, only weak inhibition bactericidal effect has been observed.

Disinfection of Spacecraft Potable Water Systems by Passivation with Ionic Silver

NASA Technical Reports Server (NTRS)

Birmele, Michele N.; McCoy, LaShelle e.; Roberts, Michael S.

2011-01-01

Microbial growth is common on wetted surfaces in spacecraft environmental control and life support systems despite the use of chemical and physical disinfection methods. Advanced control technologies are needed to limit microorganisms and increase the reliability of life support systems required for long-duration human missions. Silver ions and compounds are widely used as antimicrobial agents for medical applications and continue to be used as a residual biocide in some spacecraft water systems. The National Aeronautics and Space Administration (NASA) has identified silver fluoride for use in the potable water system on the next generation spacecraft. Due to ionic interactions between silver fluoride in solution and wetted metallic surfaces, ionic silver is rapidly depleted from solution and loses its antimicrobial efficacy over time. This report describes research to prolong the antimicrobial efficacy of ionic silver by maintaining its solubility. Three types of metal coupons (lnconel 718, Stainless Steel 316, and Titanium 6AI-4V) used in spacecraft potable water systems were exposed to either a continuous flow of water amended with 0.4 mg/L ionic silver fluoride or to a static, pre-treatment passivation in 50 mg/L ionic silver fluoride with or without a surface oxidation pre-treatment. Coupons were then challenged in a high-shear, CDC bioreactor (BioSurface Technologies) by exposure to six bacteria previously isolated from spacecraft potable water systems. Continuous exposure to 0.4 mg/L ionic silver over the course of 24 hours during the flow phase resulted in a >7-log reduction. The residual effect of a 24-hour passivation treatment in 50 mg/L of ionic silver resulted in a >3-log reduction, whereas a two-week treatment resulted in a >4-log reduction. Results indicate that 0.4 mg/L ionic silver is an effective biocide against many bacteria and that a prepassivation of metal surfaces with silver can provide additional microbial control.

THE REMOVAL OF INVASIVE SPECIES THROUGH GENE SILENCING IN MICROALGAE CULTIVATION FOR BIODIESEL

EPA Science Inventory

The successful completion of this project will be a significant advancement in promoting a domestic supply of sustainable biodiesel. Additionally, the “green” biocide proposed in this project is significantly less toxic to the environment compared to current biocides and algae...

Silver Ion Biocide Delivery System for Water Disinfection

NASA Technical Reports Server (NTRS)

Slote, Benjamin M.; Salley, Edward; Carr, Daniel; Kimble, Michael C.; Adam, Niklas

2016-01-01

U.S. space exploration missions have long considered returning to the Moon and exploration of Mars that challenge life support systems. For these long duration missions, there is interest in replacing the iodine water treatment system with ionic silver, a proven biocide. For long duration exploration missions, it is imperative that an effective biocide be used that prevents microbial growth, biofilm formation, and microbially induced corrosion in the water storage and distribution systems while minimizing logistical supply requirements associated with the biocide delivery system. Two biocide delivery systems have been developed that electrochemically produce silver ions for disinfecting water throughout the water storage and distribution system. One system uses a newly developed hybrid micro-filtration and ion-exchange membrane to produce an abundance of silver ions at the 1000 ppb level upstream in the water distribution system to prevent biofilm growth. This is followed by a downstream collection module that electrochemically removes these silver ions before the water is discharged. Another approach uses a membraneless reactor to produce a 1000 ppb silver ion concentration level that also has a mechanically driven electrode cleaning mechanism that removes oxide films ensuring long life operation. By maintaining a sufficiently high level of silver ions throughout the water storage and distribution system, biofilm formation is suppressed. This approach overcomes present concerns where spurious silver deposition occurs on the container and flow line surfaces thus lowering the silver ion concentration to unsatisfactory disinfection levels.

Fate of hydraulic fracturing chemicals under down-hole conditions

NASA Astrophysics Data System (ADS)

Blotevogel, J.; Kahrilas, G.; Corrin, E. R.; Borch, T.

2013-12-01

Hydraulic fracturing is a method to increase the yield of oil and natural gas extraction from unconventional rock formations. The process of hydrofracturing occurs via injecting water, sand, and chemicals into the production well and subjecting this mixture to high pressures to crack the rock shale, allowing increased amounts of gas and oil to seep out of the target formation. Typical constituents of the chemical mixtures are biocides, which are applied to inhibit growth of sulfate reducing bacteria in order to prevent pipe corrosion and production of hazardous gases. However, very little is known about the persistence, fate, and activity of biocides when subjected to the high temperatures and pressures of down-hole conditions. Thus, the objective of this talk is to present data from ongoing experiments focused on determining the fate of biocides commonly used for hydraulic fracturing under conditions simulating down-hole environments. Using stainless steel reactors, the high pressures and temperatures of down-hole conditions in the Marcellus shale are simulated, while concentration, speciation, and degradation of priority biocides are observed as a function of time, using primarily LC/MS techniques. The impact of water quality, shale, temperature, and pressure on the transformation kinetics and pathways of biocides will be discussed. Finally, field samples (both sediments and flowback brine) from the Marcellus shale are analyzed to verify that our lab simulations mirror real-life conditions and results.

Azole fungicides: occurrence and fate in wastewater and surface waters.

PubMed

Kahle, Maren; Buerge, Ignaz J; Hauser, Andrea; Müller, Markus D; Poiger, Thomas

2008-10-01

The mode of action of azole compounds implies a potential to affect endocrine systems of different organisms and is reason for environmental concern. The occurrence and fate of nine agricultural azole fungicides, some of them also used as biocides, and four azole pharmaceuticals were studied in wastewater treatment plants (WWTPs) and lakes in Switzerland. Two pharmaceuticals (fluconazole, clotrimazole, 10-110 ng L(-1)) and two biocides (propiconazole, tebuconazole, 1-30 ng L(-1)) were consistently observed in WWTP influents. Loads determined in untreated and treated wastewater indicated thatfluconazole, propiconazole, and tebuconazole were largely unaffected by wastewater treatment, but clotrimazole was effectively eliminated (> 80%). Incubation studies with activated sludge showed no degradation for fluconazole and clotrimazole within 24 h, but strong sorption of clotrimazole to activated sludge. Slow degradation and some sorption were observed for tebuconazole and propiconazole (degradation half-lives, 2-3 d). In lakes, fluconazole, propiconazole, and tebuconazole were detected at low nanogram-per-liter levels. Concentrations of the pharmaceutical fluconazole correlated with the expected contamination by domestic wastewater, but not those of the biocides. Per capita loads of propiconazole and tebuconazole in lakes suggested additional inputs; for example, from agricultural use or urban runoff rainwater.

Susceptibility of 169 USA300 methicillin-resistant Staphylococcus aureus isolates to two copper-based biocides, CuAL42 and CuWB50.

PubMed

Luna, Vicki Ann; Hall, Tony J; King, Debbie S; Cannons, Andrew C

2010-05-01

To test the activity of two copper-based biocides, CuAL42 and CuWB50, and benzalkonium chloride against 169 isolates of methicillin-resistant Staphylococcus aureus (MRSA) pulsotype USA300, a virulent, multiply resistant, widespread clone in the USA. Tests including MIC, MBC and time-kill studies were performed multiple times. The MIC range, MIC(50) and MIC(90) (0.59-18.75, 4.69 and 4.69 ppm, respectively) and the MBC range, MBC(50) and MBC(90) (1.17-18.75, 4.69 and 9.38 ppm, respectively) for CuAL42 were identical with those obtained with CuWB50, except that the MBC range for CuWB50 was wider (0.59-37.5 ppm). In time-kill studies, a 6 log(10) reduction of cfu was achieved within 1 h (150 ppm) and 0.5 h (300 ppm) for CuAL42, and 1.5 h (150 ppm) and 0.75 h (300 ppm) for CuWB50. Both copper-based biocides can effectively kill USA300 MRSA and may facilitate the eradication of the organism from healthcare settings.

Biocorrosion of mild steel and copper used in cooling tower water and its control.

PubMed

Li, Xiao Lei; Narenkumar, Jayaraman; Rajasekar, Aruliah; Ting, Yen-Peng

2018-03-01

The present study describes the biocorrosion of mild steel (MS1010) and pure copper (Cu) in cooling water environments (both field and lab study). Electrochemical and surface analyses of both metals were carried out to confirm the corrosion susceptibility in the presence of bacteria and inhibitor. Surface analysis of the MS and Cu coupons revealed that biofilm was developed with increasing exposure time in the field study. In the lab study, accumulation of extracellular polymeric substance over the metal surface was noticed and led to the severe pitting type of corrosion on both metal surfaces. Besides, the anti-corrosive study was carried out using the combinations of commercial corrosion inhibitor (S7653-10 ppm) with biocide (F5100-5 ppm), and the results reveal that the corrosion rate of MS and Cu was highly reduced to 0.0281 and 0.0021 mm/year (inhibitor system) than 0.1589 and 0.0177 mm/year (control system). Inhibition efficiency for both metals in the presence of inhibitor with biocide was found as 82 and 88% for MS and Cu, respectively. The present study concluded that MS was very susceptible to biocorrosion, compared to copper metal in cooling water environment. Further, the combination of the both inhibitor and biocide was effectively inhibiting the biocorrosion which was due to its antibacterial and anti-corrosive properties.

Inactivation of murine norovirus by chemical biocides on stainless steel

PubMed Central

2009-01-01

Background Human norovirus (NoV) causes more than 80% of nonbacterial gastroenteritis in Europe and the United States. NoV transmission via contaminated surfaces may be significant for the spread of viruses. Therefore, measures for prevention and control, such as surface disinfection, are necessary to interrupt the dissemination of human NoV. Murine norovirus (MNV) as a surrogate for human NoV was used to study the efficacy of active ingredients of chemical disinfectants for virus inactivation on inanimate surfaces. Methods The inactivating properties of different chemical biocides were tested in a quantitative carrier test with stainless steel discs without mechanical action. Vacuum-dried MNV was exposed to different concentrations of alcohols, peracetic acid (PAA) or glutaraldehyde (GDA) for 5 minutes exposure time. Detection of residual virus was determined by endpoint-titration on RAW 264.7 cells. Results PAA [1000 ppm], GDA [2500 ppm], ethanol [50% (v/v)] and 1-propanol [30% (v/v)] were able to inactivate MNV under clean conditions (0.03% BSA) on the carriers by ≥ 4 log10 within 5 minutes exposure time, whereas 2-propanol showed a reduced effectiveness even at 60% (v/v). Furthermore, there were no significant differences in virus reduction whatever interfering substances were used. When testing with ethanol, 1- and 2-propanol, results under clean conditions were nearly the same as in the presence of dirty conditions (0.3% BSA plus 0.3% erythrocytes). Conclusion Products based upon PAA, GDA, ethanol and 1-propanol should be used for NoV inactivation on inanimate surfaces. Our data provide valuable information for the development of strategies to control NoV transmission via surfaces. PMID:19583832

Antifungal Properties of Cationic Phenylene Ethynylenes and Their Impact on β-Glucan Exposure.

PubMed

Pappas, Harry C; Sylejmani, Rina; Graus, Matthew S; Donabedian, Patrick L; Whitten, David G; Neumann, Aaron K

2016-08-01

Candida species are the cause of many bloodstream infections through contamination of indwelling medical devices. These infections account for a 40% mortality rate, posing a significant risk to immunocompromised patients. Traditional treatments against Candida infections include amphotericin B and various azole treatments. Unfortunately, these treatments are associated with high toxicity, and resistant strains have become more prevalent. As a new frontier, light-activated phenylene ethynylenes have shown promising biocidal activity against Gram-positive and -negative bacterial pathogens, as well as the environmental yeast Saccharomyces cerevisiae In this study, we monitored the viability of Candida species after treatment with a cationic conjugated polymer [poly(p-phenylene ethynylene); PPE] or oligomer ["end-only" oligo(p-phenylene ethynylene); EO-OPE] by flow cytometry in order to explore the antifungal properties of these compounds. The oligomer was found to disrupt Candida albicans yeast membrane integrity independent of light activation, while PPE is able to do so only in the presence of light, allowing for some control as to the manner in which cytotoxic effects are induced. The contrast in killing efficacy between the two compounds is likely related to their size difference and their intrinsic abilities to penetrate the fungal cell wall. Unlike EO-OPE-DABCO (where DABCO is quaternized diazabicyclo[2,2,2]octane), PPE-DABCO displayed a strong propensity to associate with soluble β-glucan, which is expected to inhibit its ability to access and perturb the inner cell membrane of Candida yeast. Furthermore, treatment with PPE-DABCO unmasked Candida albicans β-glucan and increased phagocytosis by Dectin-1-expressing HEK-293 cells. In summary, cationic phenylene ethynylenes show promising biocidal activity against pathogenic Candida yeast cells while also exhibiting immunostimulatory effects. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Antifungal Properties of Cationic Phenylene Ethynylenes and Their Impact on β-Glucan Exposure

PubMed Central

Pappas, Harry C.; Sylejmani, Rina; Graus, Matthew S.; Donabedian, Patrick L.; Whitten, David G.

2016-01-01

Candida species are the cause of many bloodstream infections through contamination of indwelling medical devices. These infections account for a 40% mortality rate, posing a significant risk to immunocompromised patients. Traditional treatments against Candida infections include amphotericin B and various azole treatments. Unfortunately, these treatments are associated with high toxicity, and resistant strains have become more prevalent. As a new frontier, light-activated phenylene ethynylenes have shown promising biocidal activity against Gram-positive and -negative bacterial pathogens, as well as the environmental yeast Saccharomyces cerevisiae. In this study, we monitored the viability of Candida species after treatment with a cationic conjugated polymer [poly(p-phenylene ethynylene); PPE] or oligomer [“end-only” oligo(p-phenylene ethynylene); EO-OPE] by flow cytometry in order to explore the antifungal properties of these compounds. The oligomer was found to disrupt Candida albicans yeast membrane integrity independent of light activation, while PPE is able to do so only in the presence of light, allowing for some control as to the manner in which cytotoxic effects are induced. The contrast in killing efficacy between the two compounds is likely related to their size difference and their intrinsic abilities to penetrate the fungal cell wall. Unlike EO-OPE-DABCO (where DABCO is quaternized diazabicyclo[2,2,2]octane), PPE-DABCO displayed a strong propensity to associate with soluble β-glucan, which is expected to inhibit its ability to access and perturb the inner cell membrane of Candida yeast. Furthermore, treatment with PPE-DABCO unmasked Candida albicans β-glucan and increased phagocytosis by Dectin-1-expressing HEK-293 cells. In summary, cationic phenylene ethynylenes show promising biocidal activity against pathogenic Candida yeast cells while also exhibiting immunostimulatory effects. PMID:27161628

Optimisation of biocide dose as a function of residual biocide in a heat exchanger pilot plant effluent.

PubMed

Eguía, Emilio; Trueba, Alfredo; Girón, Alfredo; Río-Calonge, Belén; Otero, Félix; Bielva, Carlos

2007-01-01

Biofouling is one of the most serious problems facing numerous industrial processes. In the case of a heat exchanger unit, biological deposits adhering to the inside surface of its tubes reduce heat transfer and, thus, the thermal performance of the cycle. Control of this phenomenon is proving fundamental for both land and marine equipment to operate in optimum working conditions. Hence, it is necessary to apply antifouling methods capable of keeping surfaces free of any kind of biofouling. This paper reports on the behaviour resulting from use of the flow inversion method vs that obtained by using various chemical treatments. The study compares the effectiveness of certain chemical treatments (Na hypochlorite, peracetic acid and a compound formed by Na bromide + Na hypochlorite) for removing a biofouling film that has already formed on the inside surfaces of tubes in a heat exchanger pilot plant. The paper also addresses the issue of optimising the concentration of biocide dose as a function of the residual biocide in order minimise the environmental impact caused by effluent from industrial plants. The results indicate that it is possible to eliminate a biofilm formed on the inside surfaces of tubes by the use of intermittent doses of chemical treatments at low concentrations and over long application times. Furthermore, once the stabilisation phase is reached 6 d after starting the treatment, it is possible to maintain the conditions achieved using only 20% of the initial dosage.

Identification of ypqP as a New Bacillus subtilis Biofilm Determinant That Mediates the Protection of Staphylococcus aureus against Antimicrobial Agents in Mixed-Species Communities

PubMed Central

Sanchez-Vizuete, Pilar; Le Coq, Dominique; Bridier, Arnaud; Herry, Jean-Marie; Aymerich, Stéphane

2014-01-01

In most habitats, microbial life is organized in biofilms, three-dimensional edifices sustained by extracellular polymeric substances that enable bacteria to resist harsh and changing environments. Under multispecies conditions, bacteria can benefit from the polymers produced by other species (“public goods”), thus improving their survival under toxic conditions. A recent study showed that a Bacillus subtilis hospital isolate (NDmed) was able to protect Staphylococcus aureus from biocide action in multispecies biofilms. In this work, we identified ypqP, a gene whose product is required in NDmed for thick-biofilm formation on submerged surfaces and for resistance to two biocides widely used in hospitals. NDmed and S. aureus formed mixed biofilms, and both their spatial arrangement and pathogen protection were mediated by YpqP. Functional ypqP is present in other natural B. subtilis biofilm-forming isolates. However, the gene is disrupted by the SPβ prophage in the weak submerged-biofilm-forming strains NCIB3610 and 168, which are both less resistant than NDmed to the biocides tested. Furthermore, in a 168 laboratory strain cured of the SPβ prophage, the reestablishment of a functional ypqP gene led to increased thickness and resistance to biocides of the associated biofilms. We therefore propose that YpqP is a new and important determinant of B. subtilis surface biofilm architecture, protection against exposure to toxic compounds, and social behavior in bacterial communities. PMID:25326298

Can vaccinia virus be replaced by MVA virus for testing virucidal activity of chemical disinfectants?

PubMed

Rabenau, Holger F; Rapp, Ingrid; Steinmann, Jochen

2010-06-23

Vaccinia virus strain Lister Elstree (VACV) is a test virus in the DVV/RKI guidelines as representative of the stable enveloped viruses. Since the potential risk of laboratory-acquired infections with VACV persists and since the adverse effects of vaccination with VACV are described, the replacement of VACV by the modified vaccinia Ankara strain (MVA) was studied by testing the activity of different chemical biocides in three German laboratories. The inactivating properties of different chemical biocides (peracetic acid, aldehydes and alcohols) were tested in a quantitative suspension test according to the DVV/RKI guideline. All tests were performed with a protein load of 10% fetal calf serum with both viruses in parallel using different concentrations and contact times. Residual virus was determined by endpoint dilution method. The chemical biocides exhibited similar virucidal activity against VACV and MVA. In three cases intra-laboratory differences were determined between VACV and MVA - 40% (v/v) ethanol and 30% (v/v) isopropanol are more active against MVA, whereas MVA seems more stable than VACV when testing with 0.05% glutardialdehyde. Test accuracy across the three participating laboratories was high. Remarkably inter-laboratory differences in the reduction factor were only observed in two cases. Our data provide valuable information for the replacement of VACV by MVA for testing chemical biocides and disinfectants. Because MVA does not replicate in humans this would eliminate the potential risk of inadvertent inoculation with vaccinia virus and disease in non-vaccinated laboratory workers.

40 CFR 430.34 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

... biocides are used must achieve the following effluent limitations representing the degree of effluent... shall be subject to concentration limitations. Concentration limitations are only applicable to non-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit...

40 CFR 430.14 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

... biocides are used must achieve the following effluent limitations representing the degree of effluent... shall be subject to concentration limitations. Concentration limitations are only applicable to non-continuous dischargers. Permittees not using chlorophenolic-containing biocides must certify to the permit...

40 CFR 430.14 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... chlorophenolic-containing biocides are used must achieve the following effluent limitations representing the.../kkg (lb/1000 lb) but shall be subject to concentration limitations. Concentration limitations are only applicable to non-continuous dischargers. Permittees not using chlorophenolic-containing biocides must...

Linking the Physicochemical Properities of Titania with Its Biocidal Properities

EPA Science Inventory

LINKING THE PHYSICOCHEMICAL PROPERTIES OF TITANIA WITH ITS BIOCIDAL PROPERTIES. C. Han1, L. Putvin2, M. Pelaez1, H. Zamankhan3, H. Choi3, D. Betancourt4a, D. Dionysiou1. B. Veronesi4b, 1 Department of Biomedical, Chemical and Environmental Engineering, University of Cincinnati...

Limiting sucrose loss in Louisiana raw sugar factories: Are biocides necessary?

USDA-ARS?s Scientific Manuscript database

Sucrose deterioration takes place post-harvest in sugarcane, and is a significant problem for the sugar industry. In Louisiana, the majority of sucrose destruction occurs when cane is stock piled in mill yards and during overnight truck sleeper loads. Biocides are used in Louisiana raw sugarcane fac...

INVESTIGATION OF GAS-PHASE OZONE AS A POTENTIAL BIOCIDE

EPA Science Inventory

The paper presents data on the effect of ozone on both vegetative and spore-forming fungi as well as on spore-forming bacteria. (NOTE: Despite the wide use of ozone generators in indoor air cleaning, there is little research data on ozone's biocidal activity in the gas phase.) Dr...

Effect of Plasterboard Composition on Stachybotrys chartarum Growth and Biological Activity of Spores

PubMed Central

Murtoniemi, Timo; Nevalainen, Aino; Hirvonen, Maija-Riitta

2003-01-01

The effects of plasterboard composition on the growth and sporulation of Stachybotrys chartarum as well as on the inflammatory potential of the spores were studied. S. chartarum was grown on 13 modified plasterboards under saturated humidity conditions. The biomass was estimated by measuring the ergosterol content of the S. chartarum culture while the spore-induced cytotoxicity and production of nitric oxide (NO), tumor necrosis factor alpha (TNF-α), and interleukin-6 in mouse macrophages was used to illustrate the bioactivity of spores. The ergosterol content of S. chartarum correlated with the number of spores collected from plasterboards. The growth and sporulation decreased compared to that of the reference board in those cases where (i) the liner was treated with biocide, (ii) starch was removed from the plasterboard, or (iii) desulfurization gypsum was used in the core. Spores collected from all the plasterboards were toxic to the macrophages. The biocide added to the core did not reduce the growth; in fact, the spores collected from that board evoked the highest cytotoxicity. The conventional additives used in the core had inhibitory effects on growth. Recycled plasterboards used in the core and the board lacking the starch triggered spore-induced TNF-α production in macrophages. In summary, this study shows that the growth of a strain of S. chartarum on plasterboard and the subsequent bioactivity of spores were affected by minor changes to the composition of the core or liners, but it could not be totally prevented without resorting to the use of biocides. However, incomplete prevention of microbial growth by biocides even increased the cytotoxic potential of the spores. PMID:12839740

Organotins and new antifouling biocides in water and sediments from three Korean Special Management Sea Areas following ten years of tributyltin regulation: Contamination profiles and risk assessment.

PubMed

Lam, Nguyen Hoang; Jeong, Hui-Ho; Kang, Su-Dong; Kim, Dae-Jin; Ju, Mi-Jo; Horiguchi, Toshihiro; Cho, Hyeon-Seo

2017-08-15

A simultaneous monitoring study on organotins (butyltins and phenyltins) and most frequently used alternative antifouling biocides (Irgarol 1051, Diuron, Sea-Nine 211 and M1) in water and sediments (n=44) collected from three Special Management Sea Areas operated by Korean government. The lower concentration of butyltins (BTs) than that of new antifouling biocides (NEW) was found in water but the significant greater concentration of BTs than that of NEW was still found in sediments. The tributyltin (TBT) levels in water exceeded the chronic criterion to protect seawater aquatic life at several sites. Even ten years after the ban of the use of TBT-based antifouling paint, the concentrations of TBT, Diuron and Irgarol 1051 in sediments from shipyards exceeded global sediment quality guidelines and potentially poses adverse risks on marine organisms and extremely high concentration of TBT up to 2304ng/g was found for a sediment collected at a shipyard. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antifouling booster biocides in coastal waters of Panama: First appraisal in one of the busiest shipping zones.

PubMed

Batista-Andrade, Jahir Antonio; Caldas, Sergiane Souza; de Oliveira Arias, Jean Lucas; Castro, Italo Braga; Fillmann, Gilberto; Primel, Ednei Gilberto

2016-11-15

A baseline study for antifouling booster biocides in coastal waters of Panama is presented. Solid Phase Extraction (SPE) was used for extraction and Liquid Chromatography tandem Mass Spectrometry (LC-MS/MS) was applied for the quantification of irgarol 1051, diuron, (2-thiocyanomethylthio)benzothiazole (TCMTB), 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) and dichlofluanid. TCMTB, DCOIT and dichlofluanid were not detected in any seawater sample, while irgarol 1051 and diuron were found in four out of thirteen areas (<0.3 to 5.0ngL -1 and <2.7 to 70ngL -1 , respectively). Although the hotspots were identified in areas influenced by marinas and in one of the ports, diuron and irgarol 1051 levels were all lower than the threshold levels set by the Environmental Quality Standard of United Kingdom. However, this is only a snapshot of the status of costal water contamination by antifouling booster biocides and a more comprehensive assessment is needed to assess risks associated to long term exposure. Copyright © 2016. Published by Elsevier Ltd.

The effect of contact lens materials on disinfection activity of polyquaternium-1 and myristamidopropyl dimethylamine multipurpose solution against Staphylococcus aureus.

PubMed

Shoff, Megan E; Lucas, Anne D; Phillips, K Scott; Brown, Jennifer N; Hitchins, Victoria M; Eydelman, Malvina B

2012-11-01

This study examined the interaction of seven different lens materials with a multipurpose solution (MPS) containing the disinfectants polyquaternium-1 (0.001%) and myristamidopropyl dimethylamine (0.0005%). The objective of this study was to determine whether the different lens materials affect the concentration of a disinfectant in this commercially available MPS and the efficacy of the disinfectant against Staphylococcus aureus. Silicone hydrogel lenses (galyfilcon A, senofilcon A, comfilcon A, enfilcon A, balafilcon A, and lotrafilcon B) and a conventional hydrogel lens (etafilcon A) were soaked in polypropylene lens cases filled with commercially available MPS containing 0.001% polyquaternium-1 and 0.0005% myristamidopropyl dimethylamine for 6, 12, 24, 72, and 168 hours. Empty lens cases were also filled with MPS. After each time point, solutions from cases containing the seven types of lenses and controls were assayed for activity against S. aureus according to International Standards Organization 14729 standard with modifications. Test solutions were analyzed for polyquaternium-1 and myristamidopropyl dimethylamine concentration at each time point. The concentration of polyquaternium-1 and myristamidopropyl dimethylamine remaining in the lens cases was reduced only slightly over time. Storage with the lenses did not adversely affect biocidal efficacy of the solution, and in some cases, it was significantly better (P=0.0029). The efficacy of this polyquaternium-1 and myristamidopropyl dimethylamine MPS to kill S. aureus was not adversely affected by the presence of lens materials soaking in the cases. Thus, current methods for performing solution antimicrobial testing should be reevaluated.

Biocide squirting from an elastomeric tri-layer film.

PubMed

Sonntag, Philippe; Hoerner, Pierre; Cheymol, André; Argy, Gilles; Riess, Gérard; Reiter, Günter

2004-05-01

Protective layers typically act in a passive way by simply separating two sides. Protection is only efficient as long as the layers are intact. If a high level of protection has to be achieved by thin layers, complementary measures need to be in place to ensure safety, even after breakage of the layer-an important issue in medical applications. Here, we present a novel approach for integrating a biocide liquid into a protective film (about 300-500 microm thick), which guarantees that a sufficient amount of biocide is rapidly released when the film is punctured. The film is composed of a middle layer, containing the liquid in droplet-like compartments, sandwiched between two elastomeric boundary layers. When the film is punctured, the liquid squirts out of the middle layer. A theoretical model was used to determine the size and density of droplets that are necessary to ensure a sufficient quantity of biocide is expelled from an adequately elastic matrix to provide protection at the site of damage. We demonstrate the utility of this approach for the fabrication of surgical gloves.

Development of a biocidal treatment regime to inhibit biological growths on cultural heritage: BIODAM

NASA Astrophysics Data System (ADS)

Young, M. E.; Alakomi, H.-L.; Fortune, I.; Gorbushina, A. A.; Krumbein, W. E.; Maxwell, I.; McCullagh, C.; Robertson, P.; Saarela, M.; Valero, J.; Vendrell, M.

2008-12-01

Existing chemical treatments to prevent biological damage to monuments often involve considerable amounts of potentially dangerous and even poisonous biocides. The scientific approach described in this paper aims at a drastic reduction in the concentration of biocide applications by a polyphasic approach of biocides combined with cell permeabilisers, polysaccharide and pigment inhibitors and a photodynamic treatment. A variety of potential agents were screened to determine the most effective combination. Promising compounds were tested under laboratory conditions with cultures of rock deteriorating bacteria, algae, cyanobacteria and fungi. A subsequent field trial involved two sandstone types with natural biofilms. These were treated with multiple combinations of chemicals and exposed to three different climatic conditions. Although treatments proved successful in the laboratory, field trials were inconclusive and further testing will be required to determine the most effective treatment regime. While the most effective combination of chemicals and their application methodology is still being optimised, results to date indicate that this is a promising and effective treatment for the control of a wide variety of potentially damaging organisms colonising stone substrates.

Biocidal Defeat Agents Produced by Silver-Iodine Nanoenergetic Gas Generators

NASA Astrophysics Data System (ADS)

Davila, Ivan

Nanostructured aluminum (Al), iodine pentoxide (I2O5) nano-rods, and silver oxide (Ag2O) nanoparticles, (Al-I2O5-Ag 2O) were used to compose the ternary thermite composition that serves as a Nanoenergetic Gas Generator (NGG). This composition produces biocidal gases giving the mixture the ability to destroy highly pathogenic microorganisms or bacteria. The dissemination of the biocidal gas in combustion chamber was observed using a high-speed camera. The testing of NGG combustion process against the living Escherichia coli (E.coli) K-12 strain cells, that were cultivated/placed on the sample/chamber surfaces, demonstrated that iodine and silver atoms clouds were deposited to the bacteria surface. The 10/75/15 wt % of I2O5/Ag2O/Al composition demonstrated the best performance for destroying of E.coli with efficiency over 99 %. The results of the experiments showed that gaseous silver and iodine generated from NGG combustion produces a strong biocidal environment that has a great potential to neutralize highly pathogenic microorganisms and bacteria.

Dynamics of the Action of Biocides in Pseudomonas aeruginosa Biofilms▿†

PubMed Central

Bridier, A.; Dubois-Brissonnet, F.; Greub, G.; Thomas, V.; Briandet, R.

2011-01-01

The biocidal activity of peracetic acid (PAA) and benzalkonium chloride (BAC) on Pseudomonas aeruginosa biofilms was investigated by using a recently developed confocal laser scanning microscopy (CLSM) method that enables the direct and real-time visualization of cell inactivation within the structure. This technique is based on monitoring the loss of fluorescence that corresponds to the leakage of a fluorophore out of cells due to membrane permeabilization by the biocides. Although this approach has previously been used with success with various Gram-positive species, it is not directly applicable to the visualization of Gram-negative strains such as P. aeruginosa, particularly because of limitations regarding fluorescence staining. After adapting the staining procedure to P. aeruginosa, the action of PAA and BAC on the biofilm formed by strain ATCC 15442 was investigated. The results revealed specific inactivation patterns as a function of the mode of action of the biocides. While PAA treatment triggered a uniform loss of fluorescence in the structure, the action of BAC was first localized at the periphery of cell clusters and then gradually spread throughout the biofilm. Visualization of the action of BAC in biofilms formed by three clinical isolates then confirmed the presence of a delay in penetration, showing that diffusion-reaction limitations could provide a major explanation for the resistance of P. aeruginosa biofilms to this biocide. Biochemical analysis suggested a key role for extracellular matrix characteristics in these processes. PMID:21422224

Biocide leaching during field experiments on treated articles.

PubMed

Schoknecht, Ute; Mathies, Helena; Wegner, Robby

2016-01-01

Biocidal products can be sources of active substances in surface waters caused by weathering of treated articles. Marketing and use of biocidal products can be limited according to the European Biocidal Products Regulation if unacceptable risks to the environment are expected. Leaching of active substances from treated articles was observed in field experiments to obtain information on leaching processes and investigate the suitability of a proposed test method. Leaching under weathering conditions proceeds discontinuously and tends to decrease with duration of exposure. It does not only mainly depend on the availability of water but is also controlled by transport processes within the materials and stability of the observed substances. Runoff amount proved to be a suitable basis to compare results from different experiments. Concentrations of substances are higher in runoff collected from vertical surfaces compared to horizontal ones, whereas the leached amounts per surface area are higher from horizontal surfaces. Gaps in mass balances indicate that additional processes such as degradation and evaporation may be relevant to the fate of active substances in treated articles. Leached amounts of substances were considerably higher when the materials were exposed to intermittent water contact under laboratory conditions as compared to weathering of vertically exposed surfaces. Experiences from the field experiments were used to define parameters of a procedure that is now provided to fulfil the requirements of the Biocidal Products Regulation. The experiments confirmed that the amount of water which is in contact with exposed surfaces is the crucial parameter determining leaching of substances.

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

PubMed Central

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

2015-01-01

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

[Concentration of biocides in indoor rooms using pyrethroids as an example].

PubMed

Walker, G; Keller, R; Beckert, J; Butte, W

1994-06-01

Pyrethroids are an analogous substance group to one of the oldest known, naturally occurring insecticides pyrethrum and have replaced a number of pesticides such as Lindane, DDT and PCP on the market. Biocides are more persistent indoors than in nature, which could lead to permanent health hazards for the people concerned. Within a few days after application pyrethroids are rarely detected in room air but can be traced for a long time on textiles, furniture and in dust particles (3, 8). The investigation results of approx. 100 analyses from dust and carpet samples show that approx. 1/3 of these samples are positive for at least one pyrethroid and contain a concentration of > 2 mg substance per kg sample. The evaluation of 35 air samples taken from rooms where substances containing pyrethroids had been used at least a month prior to the investigation (the samples were sampled on active charcoal or Chromosorb) showed that pyrethroids could no longer be traced above the detection limit of 0.05-0.1 micrograms/m3. We therefore think that when investigating a contamination of rooms by biocides it is more advisable to determine pyrethroid and its synergists in the suspended dust portion and corresponding dust sample rather than analysing air by adsorption to active charcoal, Chromosorb or other carrier materials. From the observed concentrations of biocides one could conclude that in an indoor setting secondary contamination by biocides plays a more significant role in the total-body-load than that of air contamination.

Concentrations of antifouling biocides in sediment and mussel samples collected from Otsuchi bay, Japan.

PubMed

Harino, Hiroya; Yamamoto, Yoshikazu; Eguchi, Sayaka; Kawai, Shini'chiro; Kurokawa, Yuko; Arai, Takaomi; Ohji, Madoka; Okamura, Hideo; Miyazaki, Nobuyuki

2007-02-01

Organotin compounds (OTs) and representative booster biocides were measured in sediment and mussels from Otsuchi Bay, Japan. The mean amounts of tributyltin (TBT) and triphenyltin (TPT) compounds in sediment were 13 microg kg(-1) dry and 3 microg kg(-1) dry, respectively. Representative booster biocides (Sea-Nine 211, Diuron, Dichlofluanid, Irgarol 1501, M1, which is a degradation compound of Irgarol 1051, and Copper pyrithione) were also detected in sediment from Otsuchi Bay. OT concentrations were higher than those of the measured booster biocides. Otsuchi Bay was divided into four parts by cluster analysis based on OT concentrations in sediment sampled from the bay. These areas included the vicinity of a shipyard, a small fishing port, the closed inner area of the bay, and the mouth of the bay. Higher concentrations of TBT and TPT and a higher ratio of TBT to total BTs were observed in the vicinity of the shipyard. A higher concentration of TPT in comparison with TBT was detected in a small fishing port. Furthermore, OT concentrations in the mouth of the bay were higher than those in the closed-off section. OT concentrations in mussels decreased with distance from the shipyard. Otsuchi Bay was then divided into three parts by cluster analysis based on the concentrations of representative booster biocides found in the bay's sediment. These areas included the vicinity of a shipyard, a small fishing port, and other sites. Concentrations of Diuron and Irgarol 1051 in the vicinity of a shipyard and a small fishing port were dramatically high in comparison with the other sites. Copper pyrithione and Dichlofluanid in addition to Diuron and Irgarol 1051 were also detected in the area of a small fishing port. The concentrations of antifouling biocides were highest in the water in front of the shipyard and showed a marked decrease with distance from the shipyard.

Dynamics of biocide emissions from buildings in a suburban stormwater catchment - concentrations, mass loads and emission processes.

PubMed

Bollmann, Ulla E; Vollertsen, Jes; Carmeliet, Jan; Bester, Kai

2014-06-01

Biocides such as isothiazolinones, carbamates, triazines, phenylureas, azoles and others are used to protect the surfaces of buildings, e.g. painted or unpainted render or wood. These biocides can be mobilized from the materials if rainwater gets into contact with these buildings. Hence, these biocides will be found in rainwater runoff (stormwater) from buildings that is traditionally managed as "clean water" in stormwater sewer systems and often directly discharged into surface waters without further treatment. By means of a 9 month event-based high resolution sampling campaign the biocide emissions in a small suburban stormwater catchment were analysed and the emission dynamics throughout the single rain events were investigated. Five out of twelve of the rain events (peak events) proved significantly higher concentrations than the rest (average) for at least one compound. Highest median concentrations of 0.045 and 0.052 μg L(-1) were found for terbutryn and carbendazim, while the concentrations for isoproturon, diuron, N-octylisothiazolinone, benzoisothiazolinone, cybutryn, propiconazole, tebuconazole, and mecoprop were one order of magnitude lower. However, during the peak events the concentrations reached up to 1.8 and 0.3 μg L(-1) for terbutryn and carbendazim, respectively. Emissions of an averaged single family house into the stormwater sewer turned out to be 59 and 50 μg event(-1) house(-1) terbutryn and carbendazim, respectively. Emissions for the other biocides ranged from 0.1 to 11 μg event(-1) house(-1). Mass load analysis revealed that peak events contributed in single events as much to the emissions as 11 average events. However, the mass loads were highly dependent on the amounts of rainwater, i.e. the hydraulic flow in the receiving sewer pipe. The analysis of the emission dynamics showed first flush emissions only for single parameters in three events out of twelve. Generally biocides seemed to be introduced into the stormwater system rather continuously during the respective events than in the beginning of them. Mass flows during the events did correlate to driving rain, whereas mass loads neither correlated to the length or the intensity of rainfall nor the length of dry period. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effects of contact lens materials on a multipurpose contact lens solution disinfection activity against Staphylococcus aureus.

PubMed

Shoff, Megan E; Lucas, Anne D; Brown, Jennifer N; Hitchins, Victoria M; Eydelman, Malvina B

2012-11-01

To determine the effect of 8 different lens materials on polyhexamethylene biguanide (PHMB) concentration in multipurpose solution (MPS) levels over time and to determine the effect of lenses on lens solution microbial efficacy over time. Silicone hydrogel lenses and conventional hydrogel lenses were soaked in polypropylene lens cases filled with contact lens MPS containing 1 ppm PHMB for 6, 12, 24, 72, and 168 hours. Cases filled with the same solution without lenses were controls. After each time period, solutions from cases with the 8 types of lenses and controls were assayed for activity against Staphylococcus aureus according to International Organization for Standardization-14729 with modifications. Solutions were analyzed for PHMB concentration at each time point. Some of the different lens materials significantly affected the PHMB concentration (P<0.0001) and the biocidal efficacy. Etafilcon A lenses significantly decreased PHMB levels after only 6 hours of lens soak time. The product lot of MPS used was also significant (P<0.0001). Enfilcon A, senofilcon A, and lotrafilcon B lenses did not significantly decrease PHMB levels. The efficacy of MPS was affected by some lens materials and PHMB concentration. Lens materials differ in their effect on PHMB concentration and the subsequent efficacy of the MPS. Over time, some lens materials can significantly reduce the PHMB concentration and the MPS's microbial activity against S. aureus.

Influence of trophic conditions on exopolysaccharide production: bacterial biofilm susceptibility to chlorine and monochloramine.

PubMed

Samrakandi, M M; Roques, C; Michel, G

1997-08-01

This study examines the controversial efficacy of chlorine and monochloramine against biofilms that differ in their extracellular polysaccharide (EPS) content. The results point out a net variability of bacterial biofilm susceptibility according to the nutrients present. Chlorine and monochloramine showed an equal biocidal activity on lactose medium-grown E. coli ATCC 10536 and glycerol-ammonium nitrate medium-grown nonmucoid Pseudomonas aeruginosa biofilms. In contrast, the effect of monochloramine is greater compared with that of chlorine on E. coli and mucoid P. aeruginosa biofilms grown in sucrose and glycerol-ammonium nitrate media, respectively. In these culture conditions, treatment with 25 mg monochloramine/L for 2 h reduced culturable cells by 4.5 logs (99.997%) for E. coli and about 3 logs (99.87%) for mucoid P. aeruginosa while the similar treatment with chlorine reduced culturable cells in these biofilms by 2.2 logs (99.4%) and 1 log (10%), respectively. The decrease of chlorine disinfection efficacy on sucrose and glycerol-ammonium nitrate medium-grown biofilms is postulated to be linked to the higher polysaccharide production observed in these media. It seems likely that monochloramine produces a high leakage of material absorbing at 260 nm from sucrose medium-grown E. coli biofilm, which could indicate its better penetration into biofilms.

New promising antifouling agent based on polymeric biocide polyhexamethylene guanidine molybdate.

PubMed

Protasov, Alexander; Bardeau, Jean-Francois; Morozovskaya, Irina; Boretska, Mariia; Cherniavska, Tetiana; Petrus, Lyudmyla; Tarasyuk, Oksana; Metelytsia, Larisa; Kopernyk, Iryna; Kalashnikova, Larisa; Dzhuzha, Oleg; Rogalsky, Sergiy

2017-09-01

A new polymeric biocide polyhexamethylene guanidine (PHMG) molybdate has been synthesized. The obtained cationic polymer has limited water solubility of 0.015 g/100 mL and is insoluble in paint solvents. The results of acute toxicity studies indicate moderate toxicity of PHMG molybdate, which has a median lethal dose at 48 h of 0.7 mg/L for Daphnia magna and at 96 h of 17 mg/L for Danio rerio (zebrafish) freshwater model organisms. Commercial ship paint was then modified by the addition of a low concentration of polymeric biocide 5% (w/w). The painted steel panels were kept in Dnipro River water for the evaluation of the dynamics of fouling biomass. After 129-d exposure, Bryozoa dominated in biofouling of tested substrates, forming 86% (649 g/m 2 ) of the total biomass on control panel surfaces. However, considerably lower Bryozoa fouling biomass (15 g/m 2 ) was detected for coatings containing PHMG molybdate. Dreissenidae mollusks were found to form 88% (2182 g/m 2 ) of the fouling biomass on the control substrates after 228 d of exposure, whereas coatings containing PHMG molybdate showed a much lower biomass value of 23.6 g/m 2 . The leaching rate of PHMG molybdate in water was found to be similar to rates for conventional booster biocides ranging from 5.7 μg/cm 2 /d at the initial stage to 2.2 μg/cm 2 /d at steady state. Environ Toxicol Chem 2017;36:2543-2551. © 2017 SETAC. © 2017 SETAC.

Comparison of methods for evaluating ground-contact copper preservative depletion

Treesearch

Stan Lebow; Steven Halverson

2008-01-01

Depletion of the biocide(s) used to treat wood has a major influence on service life and environmental concerns. However, little is known about the extent of depletion from the specific leaching method employed. Wood treated with two types of copper-based preservatives were leached using three different methods: field stakes (American Wood Protection Association (AWPA...

Multi-component biocide protects wood from fungi and insects in UC2 applications

Treesearch

Carol A. Clausen; Vina W. Yang

2007-01-01

Development of synergistic biocides to protect wood in interior applications has been of particular interest since the recent increase of indoor mold infestations. Many products have been developed to address the recent influx of indoor mold infestations. Researchers must emphasize the use of environmentally benign chemicals due to the need for safety of human...

Encapsulation of Antifouling Organic Biocides in Poly(lactic acid) Nanoparticles.

PubMed

Kamtsikakis, Aristotelis; Kavetsou, Eleni; Chronaki, Konstantina; Kiosidou, Evangelia; Pavlatou, Evangelia; Karana, Alexandra; Papaspyrides, Constantine; Detsi, Anastasia; Karantonis, Antonis; Vouyiouka, Stamatina

2017-09-26

The scope of the current research was to assess the feasibility of encapsulating three commercial antifouling compounds, Irgarol 1051, Econea and Zinc pyrithione, in biodegradable poly(lactic acid) (PLA) nanoparticles. The emulsification-solvent evaporation technique was herein utilized to manufacture nanoparticles with a biocide:polymer ratio of 40%. The loaded nanoparticles were analyzed for their size and size distribution, zeta potential, encapsulation efficiency and thermal properties, while the relevant physicochemical characteristics were correlated to biocide-polymer system. In addition, the encapsulation process was scaled up and the prepared nanoparticles were dispersed in a water-based antifouling paint in order to examine the viability of incorporating nanoparticles in such coatings. Metallic specimens were coated with the nanoparticles-containing paint and examined regarding surface morphology.

Relationship between Legionella pneumophila and Acanthamoeba polyphaga: Physiological status and susceptibility to chemical inactivation

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

Barker, J.; Farrell, I.; Brown, M.R.W.

1992-08-01

Survival studies were conducted on Legionella pneumophila cells that had been grown intracellulary in Acanthamoeba polyphaga and then exposed to polyhexamethylene biguanide (PHMB), benzisothiazolone (BIT), and 5-chloro-N-methylisothiazolone (CMIT). Susceptibilities were also determined for L. pneumophila grown under iron-sufficient and iron-depleted conditions. BIT was relatively ineffective against cells to PHMB and CMIT. The activities of all three biocides were greatly reduced against L. pneumophila grown in amoebae. PHMB (1 [times] MIC) gave 99.99% reductions in viability for cultures grown in broth within 6 h and no detectable survivors at 24 h but only 90 and 99.9% killing at 6 h andmore » 24 h, respectively, for cells grown in amoebae. The antimicrobial properties of the three biocides against A. polyphaga were also determined. The majority of amoebae recovered from BIT treatment, but few, if any, survived CMIT treatment or exposure of PHMB. This study not only shows the profound effect that intra-amoebal growth has on the physiological status and antimicrobial susceptibility of L. pneumophila but also reveals PHMB to be a potential biocide for effective water treatment. In this respect, PHMB has significant activity, below its recommended use concentrations, against both the host amoeba and L. pneumophila.« less

An investigation of the bactericidal activity of chlorhexidine digluconateagainst multidrug-resistant hospital isolates.

PubMed

Ekizoğlu, Melike; Sağiroğlu, Meral; Kiliç, Ekrem; Hasçelik, Ayşe Gülşen

2016-04-19

Hospital infections are among the most prominent medical problems around the world. Using proper biocides in an appropriate way is critically important in overcoming this problem. Several reports have suggested that microorganisms may develop resistance or reduce their susceptibility to biocides, similar to the case with antibiotics. In this study we aimed to determine the antimicrobial activity of chlorhexidine digluconate against clinical isolates. The susceptibility of 120 hospital isolated strains of 7 bacterial genera against chlorhexidine digluconate was determined by agar dilution test, using minimum inhibitory concentration (MIC) values and the EN 1040 Basic Bactericidal Activity Test to determine the bactericidal activity. According to MIC values, Pseudomonas aeruginosa and Stenotrophomonas maltophilia were found to be less susceptible to chlorhexidine digluconate. Quantitative suspension test results showed that 4% chlorhexidine digluconate was effective against antibiotic resistant and susceptible bacteria after 5 min of contact time and can be safely used in our hospital. However, concentrations below 4% chlorhexidine digluconate caused a decrease in bactericidal activity, especially for Staphylococcus aureus and P. aeruginosa. It is crucial to use biocides at appropriate concentrations and to perform surveillance studies to trace resistance or low susceptibility patterns of S. aureus, P. aeruginosa, and other hospital isolates.

Virucidal activity of chemical biocides against mimivirus, a putative pneumonia agent.

PubMed

Campos, Rafael Kroon; Andrade, Ketyllen Reis; Ferreira, Paulo Cesar Peregrino; Bonjardim, Cláudio Antônio; La Scola, Bernard; Kroon, Erna Geessien; Abrahão, Jônatas Santos

2012-12-01

Acanthamoeba polyphaga mimivirus (APMV), the largest known virus, has been studied as a putative pneumonia agent, especially in hospital environments. Despite the repercussions of the discovery of APMV, there has been no study related to the control of APMV and the susceptibility of this virus to disinfectants. This work investigated the virucidal activity against mimivirus of chemical biocides commonly used in clinical practice for the disinfection of hospital equipment and rooms. APMV was dried on sterilized steel coupons, exposed to different concentrations of alcohols (ethanol, 1-propanol and 2-propanol) and commercial disinfectants (active chlorine, glutaraldehyde and benzalkonium chloride) and titrated in amoebas using the TCID50 value. The stability of APMV on an inanimate surface was also tested in the presence and absence of organic matter for 30 days. APMV showed a high level of resistance to chemical biocides, especially alcohols. Only active chlorine and glutaraldehyde were able to decrease the APMV titers to undetectable levels. Dried APMV showed long-lasting stability on an inanimate surface (30 days), even in the absence of organic matter. The data presented herein may help health and laboratory workers plan the best strategy to control this putative pneumonia agent from surfaces and devices. Copyright © 2012 Elsevier B.V. All rights reserved.

[Health risks from pest control products].

PubMed

Pieper, C; Holthenrich, D; Schneider, H

2014-05-01

According to European biocide legislation, pest control products require assessment and authorization by the responsible national or European authorities. Biocidal products can only be authorized if they have no unacceptable effects on human health. The health risk assessment performed for authorization comprises (a) the derivation of reference values for the active substances and substances of concern contained in the biocidal product and (b) an exposure assessment. These parameters are required for risk characterization. No unacceptable health risks are expected if the determined exposure is less than the relevant reference value. In addition, the toxicological information is used for classification of the biocidal product. The assessment may, where necessary, result in specific conditions for use or other restrictions aimed at minimizing risk. The risk to human health from pest control products is mainly based on the toxicological properties of their active substances. Commonly, the coformulants used in pest control products are of less concern than the active substances (e.g., food ingredients and animal feed products). For example, most rodenticides belong to the group of anticoagulants, which are also effective in humans. Regarding intoxications through insecticides, the group of pyrethroids is of particular importance. Fumigants containing metal phosphides, hydrogen cyanide, or sulfuryl difluoride are particularly toxic. This toxicity is linked to the high acute inhalation toxicity of the gaseous active substances themselves or, in the case of phosphides, of the released gas phosphane. The aim of health risk assessment for the authorization of biocidal products is to ensure their safe application for users and all other persons involved, assuming an adequate and label-compliant use.

Efflux-mediated antimicrobial resistance.

PubMed

Poole, Keith

2005-07-01

Antibiotic resistance continues to plague antimicrobial chemotherapy of infectious disease. And while true biocide resistance is as yet unrealized, in vitro and in vivo episodes of reduced biocide susceptibility are common and the history of antibiotic resistance should not be ignored in the development and use of biocidal agents. Efflux mechanisms of resistance, both drug specific and multidrug, are important determinants of intrinsic and/or acquired resistance to these antimicrobials, with some accommodating both antibiotics and biocides. This latter raises the spectre (as yet generally unrealized) of biocide selection of multiple antibiotic-resistant organisms. Multidrug efflux mechanisms are broadly conserved in bacteria, are almost invariably chromosome-encoded and their expression in many instances results from mutations in regulatory genes. In contrast, drug-specific efflux mechanisms are generally encoded by plasmids and/or other mobile genetic elements (transposons, integrons) that carry additional resistance genes, and so their ready acquisition is compounded by their association with multidrug resistance. While there is some support for the latter efflux systems arising from efflux determinants of self-protection in antibiotic-producing Streptomyces spp. and, thus, intended as drug exporters, increasingly, chromosomal multidrug efflux determinants, at least in Gram-negative bacteria, appear not to be intended as drug exporters but as exporters with, perhaps, a variety of other roles in bacterial cells. Still, given the clinical significance of multidrug (and drug-specific) exporters, efflux must be considered in formulating strategies/approaches to treating drug-resistant infections, both in the development of new agents, for example, less impacted by efflux and in targeting efflux directly with efflux inhibitors.

Development of an accumulation assay and evaluation of the effects of efflux pump inhibitors on the retention of chlorhexidine digluconate in Pseudomonas aeruginosa and Staphylococcus aureus.

PubMed

Mombeshora, Molly; Mukanganyama, Stanley

2017-07-26

Chlorhexidine digluconate (CHG) is used as a disinfectant. The emergence of pathogens resistant to the biocide raises health concern. Information on specific efflux mechanisms utilised by bacteria to confer reduced susceptibility to the biocide, may be used to develop ways of preventing the efflux of the biocide from nosocomial pathogens resulting in higher disinfection activity. The aim of the study was to evaluate the role of ATP-binding cassette transporters on the transport of CHG in bacteria. Clinical strains of Pseudomonas aeruginosa, Staphylococcus aureus and their respective laboratory strains ATCC 27853 and ATCC 9144 were used for susceptibility tests. The minimum inhibitory concentration (MIC) of CHG with or without an efflux pump inhibitor [reserpine or carbonyl cyanide m-chlorophenylhydrazone (CCCP)] was determined using the broth microdilution method. A spectrophotometric method to quantify the amount of chlorhexidine in a sample was developed, validated and used to quantify CHG within P. aeruginosa and S. aureus cells. In the presence of reserpine, the MIC of CHG against the clinical strains of P. aeruginosa and S. aureus decreased from 6.3 to 3.2 µg/ml but showed no change against both ATCC isolates. The MIC of CHG in the presence of CCCP for both strains of P. aeruginosa remained unchanged but showed a reduction for both isolates of S. aureus. The suitability of the spectrophotometric method developed for quantifying the amount of CHG accumulated in microbial cells was validated and used successfully to quantify CHG accumulated within bacterial cells. The spectrophotometric determination of CHG within microbial cells may be used to quantify CHG in microbial cells. Only the clinical strain of P. aeruginosa showed significant efflux of CHG suggesting the participation of efflux transporters in the pumping out of CHG from this isolate. The use of efflux pump inhibitors together with the biocide may be explored to preventing the efflux of the biocide from P. aeruginosa resulting in order to increase disinfection activity.

Arbuscular mycorrhizal inoculation following biocide treatment improves Calocedrus decurrens survival and growth in nursery and outplanting sites

Treesearch

Michael Amaranthus; David Steinfeld

2005-01-01

Commercial production of tree seedlings often includes various biocidal soil treatments for disease control. Such treatments can be effective in eliminating or reducing disease organisms in the soil, but may also eliminate non-targeted beneficial soil organisms, such as mycorrhizal fungi, that improve seedling performance, both in the nursery as well as the outplanted...

Acyclic N-Halamine Polymeric Biocidal Films

DTIC Science & Technology

2010-07-01

surfaces were rechargeable upon chlorine loss. antimicrobial, bacteria, biocidal coatings, biofilms , N-halamine U U U UU 14 Joe Wander 850 283-6240...halamine, biofilms , antimicrobial. INTRODUCTION A variety of antimicrobial organic materials, including phosp ho- nium salts [1-4], quaternary ammonium...Cotton Cellulose , J. Appl. Polym. Sci., 81: 617-624. 21. Sun, Y. and Sun, G. (2002). Durable and Regenerable Antimicrobial Textile Materials Prepared

Evaluation of the potential of ozone as a power plant biocide

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

Mattice, J.S.; Trabalka, J.R.; Adams, S.M.

1978-09-01

A review of the literature on the chemistry and biological effects of ozone was conducted to evaluate the potential of ozone to function as a power plant biocide. Evaluation of this potential is dependent upon determining the ability of ozone to maintain the integrity of both the condenser cooling system and the associated ecosystem. The well-known bactericidal capacity of ozone and the limited biofouling control studies conducted thus far suggest that ozone can control both slime and macroinvertebrate fouling at power plants. However, full-scale demonstrations of the minimum levels of ozone required and of solution of the practical aspects ofmore » application have not been performed.« less

Biocides Steering Group on human exposure assessment: a preliminary report.

PubMed

van Hemmen, J J

1999-06-30

In a project granted by DG XI of the European Commission, it is attempted to collate experimental and theoretical data on human (workers and consumers) exposure assessment to biocidal products, and to outline the methodology for sampling and measurement. On the basis of the available evidence, approaches are presented for the exposure assessment to be used for estimation of risks in authorization procedures under the recently accepted Directive 98/8/EC. Gaps in knowledge are indicated, making it possible to study the issues involved in a comprehensive and cost-effective way. Some recommendations are given on how to best do this. The current project has been detailed in a final report.

Superabsorbent cryogels decorated with silver nanoparticles as a novel water technology for point-of-use disinfection.

PubMed

Loo, Siew-Leng; Fane, Anthony G; Lim, Teik-Thye; Krantz, William B; Liang, Yen-Nan; Liu, Xin; Hu, Xiao

2013-08-20

This paper reports the preparation of poly(sodium acrylate) (PSA) cryogels decorated with silver nanoparticles (AgNPs) for point-of-use (POU) water disinfection. The PSA/Ag cryogels combine the high porosity, excellent mechanical and water absorption properties of cryogels, and uniform dispersion of fine AgNPs on the cryogel pore surface for rapid disinfection with minimal Ag release (<100 μg L(-1)). They were used in a process that employed their ability to absorb water, which subsequently could be released via application of mild pressure. Their antibacterial performance was evaluated based on the disinfection efficacies of E. coli and B. subtilis . The PSA/Ag cryogels had excellent disinfection efficacies showing close to a 3 log reduction of viable bacteria after a brief 15 s contact time. They were highly reusable as there was no significant difference in the disinfection efficacies over five cycles of operation. The biocidal action of the PSA/Ag cryogels is believed to be dominated by surface-controlled mechanisms that are dependent on direct contact of the interface of PSA/Ag cryogels with the bacterial cells. The PSA/Ag cryogels are thought to offer a simpler approach for drinking water disinfection in disaster relief applications.

Efflux pump induction by quaternary ammonium compounds and fluoroquinolone resistance in bacteria.

PubMed

Buffet-Bataillon, Sylvie; Tattevin, Pierre; Maillard, Jean-Yves; Bonnaure-Mallet, Martine; Jolivet-Gougeon, Anne

2016-01-01

Biocides, primarily those containing quaternary ammonium compounds (QAC), are heavily used in hospital environments and various industries (e.g., food, water, cosmetic). To date, little attention has been paid to potential implications of QAC use in the emergence of antibiotic resistance, especially fluoroquinolone-resistant bacteria in patients and in the environment. QAC-induced overexpression of efflux pumps can lead to: cross resistance with fluoroquinolones mediated by multidrug efflux pumps; stress response facilitating mutation in the Quinolone Resistance Determining Region; and biofilm formation increasing the risk of transfer of mobile genetic elements carrying fluoroquinolone or QAC resistance determinants. By following the European Biocidal Product Regulation, manufacturers of QAC are required to ensure that their QAC-based biocidal products are safe and will not contribute to emerging bacterial resistance.

Inhibition of calcium carbonate precipitation by aqueous extract of Paronychia argentea

NASA Astrophysics Data System (ADS)

Belarbi, Zineb; Gamby, Jean; Makhloufi, Laid; Sotta, Bruno; Tribollet, Bernard

2014-01-01

This paper focuses on the development of a new green inhibitor “aqueous extract of Paronychia argentea” for reducing calcium carbonate scale formation on metallic surfaces. The effects of temperature and biocides on the efficiency of the inhibitor were investigated. Their antiscaling properties have been evaluated by the chronoamperometry method and the calcareous layers were characterized by scanning electron microscopy observations. A complete scaling inhibition was obtained with a concentration of 70 ppm of green inhibitor for calcocarbonically pure water at 20 °C and 45 °C. However, its efficiency was decreased at 60 °C. Different commercially available biocides named B310, B320, B330 and B340 were also tested. The biocide B340 was the only found not compatible with green inhibitor.

EU Regulation of Nanobiocides: Challenges in Implementing the Biocidal Product Regulation (BPR)

PubMed Central

Brinch, Anna; Hansen, Steffen Foss; Hartmann, Nanna B.; Baun, Anders

2016-01-01

The Biocidal Products Regulation (BPR) contains several provisions for nanomaterials (NMs) and is the first regulation in the European Union to require specific testing and risk assessment for the NM form of a biocidal substance as a part of the information requirements. Ecotoxicological data are one of the pillars of the information requirements in the BPR, but there are currently no standard test guidelines for the ecotoxicity testing of NMs. The overall objective of this work was to investigate the implications of the introduction of nano-specific testing requirements in the BPR and to explore how these might be fulfilled in the case of copper oxide nanoparticles. While there is information and data available in the open literature that could be used to fulfill the BPR information requirements, most of the studies do not take the Organisation for Economic Co-operation and Development’s nanospecific test guidelines into consideration. This makes it difficult for companies as well as regulators to fulfill the BPR information requirements for nanomaterials. In order to enable a nanospecific risk assessment, best practices need to be developed regarding stock suspension preparation and characterization, exposure suspensions preparation, and for conducting ecotoxicological test. PMID:28344290

EU Regulation of Nanobiocides: Challenges in Implementing the Biocidal Product Regulation (BPR).

PubMed

Brinch, Anna; Hansen, Steffen Foss; Hartmann, Nanna B; Baun, Anders

2016-02-16

The Biocidal Products Regulation (BPR) contains several provisions for nanomaterials (NMs) and is the first regulation in the European Union to require specific testing and risk assessment for the NM form of a biocidal substance as a part of the information requirements. Ecotoxicological data are one of the pillars of the information requirements in the BPR, but there are currently no standard test guidelines for the ecotoxicity testing of NMs. The overall objective of this work was to investigate the implications of the introduction of nano-specific testing requirements in the BPR and to explore how these might be fulfilled in the case of copper oxide nanoparticles. While there is information and data available in the open literature that could be used to fulfill the BPR information requirements, most of the studies do not take the Organisation for Economic Co-operation and Development's nanospecific test guidelines into consideration. This makes it difficult for companies as well as regulators to fulfill the BPR information requirements for nanomaterials. In order to enable a nanospecific risk assessment, best practices need to be developed regarding stock suspension preparation and characterization, exposure suspensions preparation, and for conducting ecotoxicological test.

Analysis and imaging of biocidal agrochemicals using ToF-SIMS.

PubMed

Converso, Valerio; Fearn, Sarah; Ware, Ecaterina; McPhail, David S; Flemming, Anthony J; Bundy, Jacob G

2017-09-06

ToF-SIMS has been increasingly widely used in recent years to look at biological matrices, in particular for biomedical research, although there is still a lot of development needed to maximise the value of this technique in the life sciences. The main issue for biological matrices is the complexity of the mass spectra and therefore the difficulty to specifically and precisely detect analytes in the biological sample. Here we evaluated the use of ToF-SIMS in the agrochemical field, which remains a largely unexplored area for this technique. We profiled a large number of biocidal active ingredients (herbicides, fungicides, and insecticides); we then selected fludioxonil, a halogenated fungicide, as a model compound for more detailed study, including the effect of co-occurring biomolecules on detection limits. There was a wide range of sensitivity of the ToF-SIMS for the different active ingredient compounds, but fludioxonil was readily detected in real-world samples (wheat seeds coated with a commercial formulation). Fludioxonil did not penetrate the seed to any great depth, but was largely restricted to a layer coating the seed surface. ToF-SIMS has clear potential as a tool for not only detecting biocides in biological samples, but also mapping their distribution.

Biocidal and inhibitory activity screening of de novo synthesized surfactants against two eukaryotic and two prokaryotic microbial species.

PubMed

Tiecco, Matteo; Cardinali, Gianluigi; Roscini, Luca; Germani, Raimondo; Corte, Laura

2013-11-01

Thirty-six quaternary ammonium salts, of which 28 structurally different non-commercially available surfactants, were tested to screen their biocidal and inhibitory antimicrobial activity. Their activity was compared to commercially available amphiphiles as well as to non-amphiphilic quaternary ammonium salts. As target of these compounds four microbial species were employed of which two (Saccharomyces cerevisiae and Candida albicans) were important yeast in the food and clinical environment and the other two (Escherichia coli and Listeria innocua) represented the Gram negative and positive bacteria, respectively. The surfactants showed the ability to kill the microbial cells in water solution and to variably hamper their growth onto agar medium. The non-amphiphilic compounds (which represent analogues of some surfactants used in this study, since they have the same head group but no hydrophobic portion) had little effect in solution and no effect against the microbial growth on plate. Amphoteric and non-amphoteric zwitterionic surfactants showed reduced biocidal activity. The most active antimicrobial agent was N-tetradecyltropinium bromide (23S) surfactant. The presence of cells did not significantly affect the ability to form micelles, as demonstrated by comparative conductometric measurements. Copyright © 2013 Elsevier B.V. All rights reserved.

Kinetic Tetrazolium Microtiter Assay

NASA Technical Reports Server (NTRS)

Pierson, Duane L.; Stowe, Raymond; Koenig, David

1993-01-01

Kinetic tetrazolium microtiter assay (KTMA) involves use of tetrazolium salts and Triton X-100 (or equivalent), nontoxic, in vitro color developer solubilizing colored metabolite formazan without injuring or killing metabolizing cells. Provides for continuous measurement of metabolism and makes possible to determine rate of action of antimicrobial agent in real time as well as determines effective inhibitory concentrations. Used to monitor growth after addition of stimulatory compounds. Provides for kinetic determination of efficacy of biocide, greatly increasing reliability and precision of results. Also used to determine relative effectiveness of antimicrobial agent as function of time. Capability of generating results on day of test extremely important in treatment of water and waste, disinfection of hospital rooms, and in pharmaceutical, agricultural, and food-processing industries. Assay also used in many aspects of cell biology.

Combined effects of pharmaceuticals, personal care products, biocides and organic contaminants on the growth of Skeletonema pseudocostatum.

PubMed

Petersen, Karina; Heiaas, Harald Hasle; Tollefsen, Knut Erik

2014-05-01

Organisms in the environment are exposed to a number of pollutants from different compound groups. In addition to the classic pollutants like the polychlorinated biphenyls, polyaromatic hydrocarbons (PAHs), alkylphenols, biocides, etc. other compound groups of concern are constantly emerging. Pharmaceuticals and personal care products (PPCPs) can be expected to co-occur with other organic contaminants like biocides, PAHs and alkylphenols in areas affected by wastewater, industrial effluents and intensive recreational activity. In this study, representatives from these four different compound groups were tested individually and in mixtures in a growth inhibition assay with the marine algae Skeletonema pseudocostatum (formerly Skeletonema costatum) to determine whether the combined effects could be predicted by models for additive effects; the concentration addition (CA) and independent action (IA) prediction model. The eleven tested compounds reduced the growth of S. pseudocostatum in the microplate test in a concentration-dependent manner. The order of toxicity of these chemicals were irgarol>fluoxetine>diuron>benzo(a)pyrene>thioguanine>triclosan>propranolol>benzophenone 3>cetrimonium bromide>4-tert-octylphenol>endosulfan. Several binary mixtures and a mixture of eight compounds from the four different compound groups were tested. All tested mixtures were additive as model deviation ratios, the deviation between experimental and predicted effect concentrations, were within a factor of 2 from one or both prediction models (e.g. CA and IA). Interestingly, a concentration dependent shift from IA to CA, potentially due to activation of similar toxicity pathways at higher concentrations, was observed for the mixture of eight compounds. The combined effects of the multi-compound mixture were clearly additive and it should therefore be expected that PPCPs, biocides, PAHs and alkylphenols will collectively contribute to the risk in areas contaminated by such complex mixtures. Copyright © 2014 Elsevier B.V. All rights reserved.

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

PubMed

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

2014-08-01

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

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

PubMed

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

2006-01-01

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

Biocides for the Battlefield - Interim Report

DTIC Science & Technology

2010-09-24

for public release; distribution is unlimited. James H . Wynne Materials Chemistry Branch Chemistry Division Preston a. Fulmer Chemical Dynamics and...b. ABSTRACT c. THIS PAGE 18. NUMBER OF PAGES 17. LIMITATION OF ABSTRACT Biocides for the Battlefield—Interim Report James H . Wynne and Preston A...distribution is unlimited. Unclassified Unclassified Unclassified SAR 25 James H . Wynne (202) 404-4010 The ability to disinfect surfaces and manufacture self

Microencapsulation of Biocides for Reduced Copper, Long-life Antifouling Coatings

DTIC Science & Technology

2007-02-01

together with Microtek produce microencapsulated DCOIT. Laboratory facilities equipped to produce from 100g – 500kg batches of microcapsules . These...FINAL REPORT Microencapsulation of Biocides for Reduced Copper, Long-life Antifouling Coatings ESTCP Project WP-0306 FEBRUARY 2007...octyl-4-isothi azolin-3-one (DCOIT) hns been microencapsulated nnd incorporated into collUllercially relevanl AF coatings. Re•ulls demon•ll’ntt long

Performance of the Tin-Free Antifouling Coating International Ecoloflex in DSTO/RAN Trials

DTIC Science & Technology

2008-10-01

Science and Technology Organisation DSTO-TR-2203 ABSTRACT A national and global ban on the application of antifouling paints containing tributyltin (TBT...Ecoloflex in DSTO/RAN Trials Executive Summary The antifouling biocide tributyltin (TBT) has provided the most effective means of preventing fouling...24 DSTO-TR-2203 1. Introduction Antifouling paints containing tributyltin (TBT) as the primary biocide were

Environmental Fate and Effects of Organotin Biocides: A Molecular and Microbiological Assessment.

DTIC Science & Technology

1986-12-12

GROUP__ biocides, antifouling compounds, environment, tributyltin , 08 organotin, tin, standards, biodegradation, organometals !9.\\ASTRACT (Continue on...and effects of the toxic tributyltin species, an active agent in new ship antifouling coatings. -44-4eiped- vltratrace’butyltin measurement’ ehdl c d...Standards Gaithersburg, MD 20899 Introduction New tributyltin -based antifouling paints, some types already widely used in the private sector, offer

Resistance to Biocides in Listeria monocytogenes Collected in Meat-Processing Environments

PubMed Central

Conficoni, Daniele; Losasso, Carmen; Cortini, Enzo; Di Cesare, Andrea; Cibin, Veronica; Giaccone, Valerio; Corno, Gianluca; Ricci, Antonia

2016-01-01

The emergence of microorganisms exerting resistance to biocides is a challenge to meat-processing environments. Bacteria can be intrinsically resistant to biocides but resistance can also be acquired by adaptation to their sub-lethal concentrations. Moreover, the presence of biocide resistance determinants, which is closely linked to antibiotic resistance determinants, could lead to co-selection during disinfection practices along the food chain, and select cross-resistant foodborne pathogens. The purpose of this work was to test the resistance of wild strains of Listeria monocytogenes, isolated from pork meat processing plants, toward benzalkonium chloride (BC), used as proxy of quaternary ammonium compounds. Furthermore, the expression of two non-specific efflux pumps genes (lde and mdrL) under biocide exposure was evaluated. L. monocytogenes were isolated from five processing plants located in the Veneto region (northeast of Italy) before and after cleaning and disinfection (C&D) procedures. A total of 45 strains were collected: 36 strains before and nine after the C&D procedures. Collected strains were typed according to MLST and ERIC profiles. Strains sampled in the same site, isolated before, and after the C&D procedures and displaying the same MLST and ERIC profiles were tested for their sensitivity to different concentrations of BC, in a time course assay. The expression of non-specific efflux pumps was evaluated at each time point by qPCR using tufA gene as housekeeping. A differential expression of the two investigated genes was observed: lde was found to be more expressed by the strains isolated before C&D procedures while its expression was dose-dependent in the case of the post C&D procedures strain. On the contrary, the expression of mdrL was inhibited under low biocidal stress (10 ppm BC) and enhanced in the presence of high stress (100 ppm BC). These findings suggests a possible role for C&D procedures to select L. monocytogenes persisters, pointing out the importance of dealing with the identification of risk factors in food plants sanification procedures that might select more tolerant strains. PMID:27807430

Nonhazardous Urine Pretreatment Method

NASA Technical Reports Server (NTRS)

Akse, James R.; Holtsnider, John T.

2012-01-01

A method combines solid phase acidification with two non-toxic biocides to prevent ammonia volatilization and microbial proliferation. The safe, non-oxidizing biocide combination consists of a quaternary amine and a food preservative. This combination has exhibited excellent stabilization of both acidified and unacidified urine. During pretreatment tests, composite urine collected from donors was challenged with a microorganism known to proliferate in urine, and then was processed using the nonhazardous urine pre-treatment method. The challenge microorganisms included Escherichia coli, a common gram-negative bacteria; Enterococcus faecalis, a ureolytic gram-positive bacteria; Candida albicans, a yeast commonly found in urine; and Aspergillus niger, a problematic mold that resists urine pre-treatment. Urine processed in this manner remained microbially stable for over 57 days. Such effective urine stabilization was achieved using non-toxic, non-oxidizing biocides at higher pH (3.6 to 5.8) than previous methods in use or projected for use aboard the International Space Station (ISS). ISS urine pretreatment methods employ strong oxidants including ozone and hexavalent chromium (Cr(VI)), a carcinogenic material, under very acidic conditions (pH = 1.8 to 2.4). The method described here offers a much more benign chemical environment than previous pretreatment methods, and will lower equivalent system mass (ESM) by reducing containment volume and mass, system complexity, and crew time needed to handle pre-treatment chemicals. The biocides, being non-oxidizing, minimize the potential for chemical reactions with urine constituents to produce volatile, airborne contaminants such as cyanogen chloride. Additionally, the biocides are active under significantly less acidic conditions than those used in the current system, thereby reducing the degree of required acidification. A simple flow-through solid phase acidification (SPA) bed is employed to overcome the natural buffering capacity of urine, and to lower the pH to levels that fix ammoniacal nitrogen in the non-volatile and highly water soluble NH4 + form. Citric acid, a highly soluble, solid tricarboxylic acid essential to cellular metabolism, and typically used as a food preservative, has also been shown to efficiently acidify urine in conjunction with non-oxidizing biocides to provide effective stabilization with respect to both microbial growth and ammonia volatilization.

C-Phycocyanin protects against acute tributyltin chloride neurotoxicity by modulating glial cell activity along with its anti-oxidant and anti-inflammatory property: A comparative efficacy evaluation with N-acetyl cysteine in adult rat brain.

PubMed

Mitra, Sumonto; Siddiqui, Waseem A; Khandelwal, Shashi

2015-08-05

Spirulina is a widely used health supplement and is a dietary source of C-Phycocyanin (CPC), a potent anti-oxidant. We have previously reported the neurotoxic potential of tributyltin chloride (TBTC), an environmental pollutant and potent biocide. In this study, we have evaluated the protective efficacy of CPC against TBTC induced neurotoxicity. To evaluate the extent of neuroprotection offered by CPC, its efficacy was compared with the degree of protection offered by N-acetylcysteine (NAC) (a well known neuroprotective drug, taken as a positive control). Male Wistar rats (28 day old) were administered with 20mg/kg TBTC (oral) and 50mg/kg CPC or 50mg/kg NAC (i.p.), alone or in combination, and various parameters were evaluated. These include blood-brain barrier (BBB) damage; redox parameters (ROS, GSH, redox pathway associated enzymes, oxidative stress markers); inflammatory, cellular, and stress markers; apoptotic proteins and in situ cell death assay (TUNEL). We observed increased CPC availability in cortical tissue following its administration. Although BBB associated proteins like claudin-5, p-glycoprotein and ZO-1 were restored, CPC/NAC failed to protect against TBTC induced overall BBB permeability (Evans blue extravasation). Both CPC and NAC remarkably reduced oxidative stress and inflammation. NAC effectively modulated redox pathway associated enzymes whereas CPC countered ROS levels efficiently. Interestingly, CPC and NAC were equivalently capable of reducing apoptotic markers, astroglial activation and cell death. This study illustrates the various pathways involved in CPC mediated neuroprotection against this environmental neurotoxicant and highlights its capability to modulate glial cell activity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

CrossWater - Modelling micropollutant loads from different sources in the Rhine basin

NASA Astrophysics Data System (ADS)

Moser, Andreas; Bader, Hans-Peter; Fenicia, Fabrizio; Scheidegger, Ruth; Stamm, Christian

2015-04-01

The contamination of fresh surface waters with micropollutants originating from various sources is a growing environmental issue. The challenges for an effective political regulation are numerous, particularly for international water basins. One prerequisite for effective management is the knowledge of water quality across different parts of a basin. In this study within the Rhine basin, the spatial patterns of micropollutant loads and concentrations from different use classes are investigated with a mass flow analysis and compared to the established territorial jurisdictions on micropollutants and water quality. The source area of micropollutants depends on the specific use of a compound. The focus of this study is on i) herbicides from agricultural landuse, ii) biocides from material protection on buildings and iii) human pharmaceuticals from households. The total mass of micropollutants available for release to the stream network is estimated based on statistical application and consumption data. Based on GIS data of agricultural landuse, vector data of buildings, wastewater treatment plant (WWTP) locations, respectively, the available mass of micropollutants is spatially distributed to the catchment areas. The actual release of micropollutants to the stream network is calculated with empirical loss rates related to river discharge for agricultural herbicides and to precipitation for biocides. For the pharmaceuticals the release is coupled to the metabolism rates and elimination rates in WWTP. For a first approximation national sales are downscaled to the catchment level to specify the available mass for selected model compounds (agricultural herbicides: Isoproturon, biocides: Carbendazim, human pharmaceuticals: Carbamazepine and Diclofenac). The available mass of herbicides and biocides is multiplied with empirical loss rates independent from discharge or precipitation to calculate the loads. The release of the pharmaceuticals was calculated by multiplying average consumption numbers with the person equivalent of the WWTP and the elimination rates. The comparison of pollutant loads to 7-day composite samples of all compounds at 15 locations along the Rhine yield plausible results.

Prevalence of bacteria resistant to antibiotics and/or biocides on meat processing plant surfaces throughout meat chain production.

PubMed

Lavilla Lerma, Leyre; Benomar, Nabil; Gálvez, Antonio; Abriouel, Hikmate

2013-02-01

In order to investigate the prevalence of resistant bacteria to biocides and/or antibiotics throughout meat chain production from sacrifice till end of production line, samples from various surfaces of a goat and lamb slaughterhouse representative of the region were analyzed by the culture dependent approach. Resistant Psychrotrophs (n=255 strains), Pseudomonas sp. (n=166 strains), E. coli (n=23 strains), Staphylococcus sp. (n=17 strains) and LAB (n=82 represented mainly by Lactobacillus sp.) were isolated. Resistant psychrotrophs and pseudomonads (47 and 29%, respectively) to different antimicrobials were frequently detected in almost all areas of meat processing plant regardless the antimicrobial used, although there was a clear shift in the spectrum of other bacterial groups and for this aim such resistance was determined according to several parameters: antimicrobial tested, sampling zone and the bacterial group. Correlation of different parameters was done using a statistical tool "Principal component analysis" (PCA) which determined that quaternary ammonium compounds and hexadecylpyridinium were the most relevant biocides for resistance in Pseudomonas sp., while ciprofloxacin and hexachlorophene were more relevant for psychrotrophs, LAB, and in lesser extent Staphylococcus sp. and Escherichia coli. On the other hand, PCA of sampling zones determined that sacrifice room (SR) and cutting room (CR) considered as main source of antibiotic and/or biocide resistant bacteria showed an opposite behaviour concerning relevance of antimicrobials to determine resistance being hexadecylpyridinium, cetrimide and chlorhexidine the most relevant in CR, while hexachlorophene, oxonia 6P and PHMG the most relevant in SR. In conclusion, rotational use of the relevant biocides as disinfectants in CR and SR is recommended in an environment which is frequently disinfected. Copyright © 2012 Elsevier B.V. All rights reserved.

Quorum Sensing and the Use of Quorum Quenchers as Natural Biocides to Inhibit Sulfate-Reducing Bacteria.

PubMed

Scarascia, Giantommaso; Wang, Tiannyu; Hong, Pei-Ying

2016-12-15

Sulfate-reducing bacteria (SRB) are one of the main protagonist groups of biocorrosion in the seawater environment. Given their principal role in biocorrosion, it remains a crucial task to develop strategies to reduce the abundance of SRBs. Conventional approaches include the use of biocides and antibiotics, which can impose health, safety, and environmental concerns. This review examines an alternative approach to this problem. This is achieved by reviewing the role of quorum sensing (QS) in SRB populations and its impact on the biofilm formation process. Genome databases of SRBs are mined to look for putative QS systems and homologous protein sequences representative of autoinducer receptors or synthases. Subsequently, this review puts forward the potential use of quorum quenchers as natural biocides against SRBs and outlines the potential strategies for the implementation of this approach.

Biocidal action of ozone-treated polystyrene surfaces on vegetative and sporulated bacteria

NASA Astrophysics Data System (ADS)

Mahfoudh, Ahlem; Barbeau, Jean; Moisan, Michel; Leduc, Annie; Séguin, Jacynthe

2010-03-01

Surfaces of materials can be modified to ensure specific interaction features with microorganisms. The current work discloses biocidal properties of polystyrene (PS) Petri-dish surfaces that have been exposed to a dry gaseous-ozone flow. Such treated PS surfaces are able to inactivate various species of vegetative and sporulated bacteria on a relatively short contact time. Denaturation of proteins seems likely based on a significant loss of enzymatic activity of the lysozyme protein. Characterization of these surfaces by atomic-force microscopy (AFM), Fourier-transform infra-red (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) reveals specific structural and chemical modifications as compared to untreated PS. Persistence of the biocidal properties of these treated surfaces is observed. This ozone-induced process is technically simple to achieve and does not require active precursors as in grafting.

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

PubMed

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

2015-09-15

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

Nanostructured Block Copolymer Coatings for Biofouling Inhibition

DTIC Science & Technology

2015-06-30

nm) High resolution vibrational sensitive images Figure 7 - The instrument provides best-in-world performance. The images are of a boron nitride...2 patents pending, publications and some trade secrets. The pure biocide has been tested by independent labs for toxicity to various mammals and...cash investments in Sylleta, which continue. In Figure 8 are the data on the toxicity of the active ingredient (biocide), which is surface tethered in

Effects of materials surface preparation for use in spacecraft potable water storage tanks

NASA Astrophysics Data System (ADS)

Wallace, William T.; Wallace, Sarah L.; Loh, Leslie J.; Kuo, C. K. Mike; Hudson, Edgar K.; Marlar, Tyler J.; Gazda, Daniel B.

2017-12-01

Maintaining a safe supply of potable water is of utmost importance when preparing for long-duration spaceflight missions, with the minimization of microbial growth being one major aspect. While biocides, such as ionic silver, historically have been used for microbial control in spaceflight, their effectiveness is sometimes limited due to surface reactions with the materials of the storage containers that reduce their concentrations below the effective range. For the Multi-Purpose Crew Vehicle, the primary wetted materials of the water storage system are stainless steel and a titanium alloy, and ionic silver has been chosen to serve as the biocide. As an attempt to understand what processes might reduce the known losses of silver, different treatment processes were attempted and samples of the wetted materials were tested, individually and together, to determine the relative loss of biocide under representative surface area-to-volume ratios. The results of testing presented here showed that the materials could be treated by a nitric acid rinse or a high-concentration silver spike to reduce the loss of silver and bacterial growth. It was also found that the minimum biocidal concentration could be maintained for over 28 days. These results have pointed to approaches that could be used to successfully maintain silver in spacecraft water systems for long-duration missions.

Biocide triclosan impairs byssus formation in marine mussels Mytilus galloprovincialis.

PubMed

Motta, C M; Tizzano, M; Tagliafierro, A M; Simoniello, P; Panzuto, R; Esposito, L; Migliaccio, V; Rosati, L; Avallone, B

2018-05-22

The effects of the biocide Triclosan, used in personal care products and known as a common environmental contaminant, on byssal apparatus were studied in the marine mussel Mytilus galloprovincialis. Experimental evidences indicated that an exposure for 7 days at a concentration of 10 μg/L induced marked alterations in the byssus gland resulting in a significant delay in byssus regrowth and in a decrease in threads resistance to traction. Such alterations in animals exposed to tidal and waves action would cause a significant loss in ecological fitness and severely impact on mussel survival. Triclosan release in coastal environments therefore should be more carefully monitored to prevent drastic consequences. Copyright © 2018 Elsevier Ltd. All rights reserved.

The potent antimicrobial properties of cell penetrating peptide-conjugated silver nanoparticles with excellent selectivity for gram-positive bacteria over erythrocytes.

PubMed

Liu, Lihong; Yang, Jun; Xie, Jianping; Luo, Zhentao; Jiang, Jiang; Yang, Yi Yan; Liu, Shaomin

2013-05-07

Silver nanoparticles are of great interest for use as antimicrobial agents. Studies aimed at producing potent nano-silver biocides have focused on manipulation of particle size, shape, composition and surface charge. Here, we report the cell penetrating peptide catalyzed formation of antimicrobial silver nanoparticles in N,N-dimethylformamide. The novel nano-composite demonstrated a distinctly enhanced biocidal effect toward bacteria (gram-positive Bacillus subtilis, gram-negative Escherichia coli) and pathogenic yeast (Candida albicans), as compared to triangular and extremely small silver nanoparticles. In addition, a satisfactory biocompatibility was verified by a haemolysis test. Our results provide a paradigm in developing strategies that can maximize the silver nanoparticle application potentials while minimizing the toxic effects.

Consumer antibacterial soaps: effective or just risky?

PubMed

Aiello, Allison E; Larson, Elaine L; Levy, Stuart B

2007-09-01

Much has been written recently about the potential hazards versus benefits of antibacterial (biocide)-containing soaps. The purpose of this systematic literature review was to assess the studies that have examined the efficacy of products containing triclosan, compared with that of plain soap, in the community setting, as well as to evaluate findings that address potential hazards of this use--namely, the emergence of antibiotic-resistant bacteria. The PubMed database was searched for English-language articles, using relevant keyword combinations for articles published between 1980 and 2006. Twenty-seven studies were eventually identified as being relevant to the review. Soaps containing triclosan within the range of concentrations commonly used in the community setting (0.1%-0.45% wt/vol) were no more effective than plain soap at preventing infectious illness symptoms and reducing bacterial levels on the hands. Several laboratory studies demonstrated evidence of triclosan-adapted cross-resistance to antibiotics among different species of bacteria. The lack of an additional health benefit associated with the use of triclosan-containing consumer soaps over regular soap, coupled with laboratory data demonstrating a potential risk of selecting for drug resistance, warrants further evaluation by governmental regulators regarding antibacterial product claims and advertising. Further studies of this issue are encouraged.

Application of green fluorescent protein to measure antimicrobial efficacy and the kinetics of cell death against Escherichia coli.

PubMed

Greenhalgh, Richard; Greenhalgh, Malcolm; Alshareef, Fadwa; Robson, Geoffrey D

2017-10-01

Industrial antimicrobials have been extensively used to control unwanted microbial growth by incorporation into a variety of products such as plastics and paints, reducing biodeterioration and biofouling and extending the lifespan of the product. Industrial antimicrobials generally have broad sites of action affecting core cellular functions such as central metabolism, enzyme function, cell wall or DNA synthesis and can either be biocidal or biostatic. In addition, susceptibility can be affected by the metabolic state of the microbe, with metabolically inactive cells generally more resistant than metabolically active cells. Previously it was demonstrated that cytosolically expressed green fluorescent protein could be used as a real-time viability indicator in the yeast Aureobasidium pullulans based on the pH dependent fluorescence of GFP and the collapse of the proton gradient across the cell membrane during cell death. In this study we report on the development and validation of an equivalent GFP fluorescence viability assay in Escherichia coli and used this assay to study the effect of five antimicrobials commonly used in plastics; 4,5-dichloro-2-octyl-isothiazol-3-one (DCOIT), sodium pyrithione, 1,2-benzisothiazol-3-one (BIT), 2-octyl-isothiazol-3-one (OIT) and n-butyl-1,2-benzisothiazol-3-one (BBIT). The results demonstrate broad differences amongst the antimicrobials in both relative efficacy, rate of effect and for some antimicrobials, marked differences in sensitivity toward growing and non-growing cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Control of multidrug-resistant planktonic Acinetobacter baumannii: biocidal efficacy study by atmospheric-pressure air plasma

NASA Astrophysics Data System (ADS)

Zhe, RUAN; Yajun, GUO; Jing, GAO; Chunjun, YANG; Yan, LAN; Jie, SHEN; Zimu, XU; Cheng, CHENG; Xinghao, LIU; Shumei, ZHANG; Wenhui, DU; Paul, K. CHU

2018-04-01

In this research, an atmospheric-pressure air plasma is used to inactivate the multidrug-resistant Acinetobacter baumannii in liquid. The efficacy of the air plasma on bacterial deactivation and the cytobiological variations after the plasma treatment are investigated. According to colony forming units, nearly all the bacteria (6-log) are inactivated after 10 min of air plasma treatment. However, 7% of the bacteria enter a viable but non-culturable state detected by the resazurin based assay during the same period of plasma exposure. Meanwhile, 86% of the bacteria lose their membrane integrity in the light of SYTO 9/PI staining assay. The morphological changes in the cells are examined by scanning electron microscopy and bacteria with morphological changes are rare after plasma exposure in the liquid. The concentrations of the long-living RS, such as H2O2, {{{{NO}}}3}-, and O3, in liquid induced by plasma treatment are measured, and they increase with plasma treatment time. The changes of the intracellular ROS may be related to cell death, which may be attributed to oxidative stress and other damage effects induced by RS plasma generated in liquid. The rapid and effective bacteria inactivation may stem from the RS in the liquid generated by plasma and air plasmas may become a valuable therapy in the treatment of infected wounds.

Regenerable Iodine Water-Disinfection System

NASA Technical Reports Server (NTRS)

Sauer, Richard L.; Colombo, Gerald V.; Jolly, Clifford D.

1994-01-01

Iodinated resin bed for disinfecting water regenerated to extend useful life. Water flows through regeneration bed of crystalline iodine during regeneration. At other times, flow diverted around regeneration bed. Although regeneration cycle manually controlled readily automated to start and stop according to signals from concentration sensors. Further benefit of regeneration is bed provides highly concentrated biocide source when needed. Concentrated biocide used to superiodinate system after contamination from routine maintenance or unexpected introduction of large concentration of microbes.

Nonhazardous Chemical Treatments and Smart Monitoring and Control System for Heating and Cooling Systems

DTIC Science & Technology

2007-06-01

box with the dip slides provides application instructions and illustrates acceptable bacteria levels. Both dip slide and Biotrace ATP Luminometer...Control Good Control Poor Control Biotrace ATP Planktonic 100 to 300 RLU 300 to 1000 RLU >1000 RLU Dip Tube Anaerobic Bacteria 0 organism/mL ɝ...completed monthly to record biocide levels and bacteria tests. Another biocide test method, the Biotrace ATP Luminometer, measures planktonic

Quorum Sensing and the Use of Quorum Quenchers as Natural Biocides to Inhibit Sulfate-Reducing Bacteria

PubMed Central

Scarascia, Giantommaso; Wang, Tiannyu; Hong, Pei-Ying

2016-01-01

Sulfate-reducing bacteria (SRB) are one of the main protagonist groups of biocorrosion in the seawater environment. Given their principal role in biocorrosion, it remains a crucial task to develop strategies to reduce the abundance of SRBs. Conventional approaches include the use of biocides and antibiotics, which can impose health, safety, and environmental concerns. This review examines an alternative approach to this problem. This is achieved by reviewing the role of quorum sensing (QS) in SRB populations and its impact on the biofilm formation process. Genome databases of SRBs are mined to look for putative QS systems and homologous protein sequences representative of autoinducer receptors or synthases. Subsequently, this review puts forward the potential use of quorum quenchers as natural biocides against SRBs and outlines the potential strategies for the implementation of this approach. PMID:27983678

The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor.

PubMed

Minnoş, Bihter; Ilhan-Sungur, Esra; Çotuk, Ayşın; Güngör, Nihal Doğruöz; Cansever, Nurhan

2013-01-01

The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor was investigated over a 10-month period in a hotel. Planktonic and sessile numbers of sulphate reducing bacteria (SRB) and heterotrophic bacteria were monitored. The corrosion rate was determined by the weight loss method. The corrosion products were analyzed by energy dispersive X-ray spectroscopy and X-ray diffraction. A mineralized, heterogeneous biofilm was observed on the coupons. Although a biocide and a corrosion inhibitor were regularly added to the cooling water, the results showed that microorganisms, such as SRB in the mixed species biofilm, caused corrosion of galvanized steel. It was observed that Zn layers on the test coupons were completely depleted after 3 months. The Fe concentrations in the biofilm showed significant correlations with the weight loss and carbohydrate concentration (respectively, p < 0.01 and p < 0.01).

Toxicity of anti-fouling biocides to encysted metacercariae of Echinoparyphium recurvatum (Digenea: Echinostomatidae) and their snail hosts.

PubMed

Morley, N J; Leung, K M Y; Morritt, D; Crane, M

2004-07-01

The toxicity of the anti-fouling biocides tributyltin (TBTO), copper, and Irgarol 1051 (irgarol) at a nominal concentration of 10 microg/l over a 30 day period were investigated against the viability of metacercarial cysts of the digenean parasite Echinoparyphium recurvatum resident within the body of two common freshwater snails, Lymnaea peregra and Physa fontinalis. Reduced parasite viability was found under most exposures in both snail species. However a greater effect of toxicant exposure was found in cysts within P. fontinalis compared to those in L. peregra. This was associated with an increased mortality of the host snail. Among all tested biocides, TBTO exposures induced the highest mortality to both the parasite and their hosts. These results suggest that parasite viability is interlinked with survival of the host snail. The mechanisms of differing toxicity between host species and its relevance to successful parasite transmission to the next host are discussed.

Distribution of butyltins and alternative antifouling biocides in sediments from shipping and shipbuilding areas in South Korea.

PubMed

Kim, Nam Sook; Hong, Sang Hee; An, Joon Geon; Shin, Kyung-Hoon; Shim, Won Joon

2015-06-15

The occurrence and distribution of tributyltin (TBT) and alternative biocides were investigated in sediment from semi-enclosed bays, fishing ports, and large commercial harbors in Korea. Extremely high concentration of TBT (55,264ngSn/g) was detected near a large shipyard, even after a total ban on its use in Korea. Diuron was the biocide with the highest detection frequency and concentration levels, followed by Irgarol 1051. Sea-Nine 211 was detected at 3 of 32 stations surveyed. Dichlofluanid, zinc and copper pyrithiones levels were below the detection limits at all the stations surveyed. The relatively high levels of Diuron (9-62.3ng/g) and Irgarol 1051 (1.5-11.5ng/g) were detected in harbor and shipyard areas. Diuron and Irgarol 1051 levels including TBT in sediments from hot spots in Korea exceeded global sediment quality guidelines. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antibacterial and Antifungal Activity of ZnO Containing Glasses.

PubMed

Esteban-Tejeda, Leticia; Prado, Catuxa; Cabal, Belén; Sanz, Jesús; Torrecillas, Ramón; Moya, José Serafín

2015-01-01

A new family of non-toxic biocides based on low melting point (1250°C) transparent glasses with high content of ZnO (15-40wt%) belonging to the miscibility region of the B2O3-SiO2-Na2O-ZnO system has been developed. These glasses have shown an excellent biocide activity (logarithmic reduction >3) against Gram- (E. coli), Gram+ (S. aureus) and yeast (C. krusei); they are chemically stable in different media (distilled water, sea-like water, LB and DMEN media) as well as biocompatible. The cytotoxicity was evaluated by the Neutral Red Uptake using NIH-3T3 (mouse embryonic fibroblast cells) and the cell viability was >80%. These new glasses can be considered in several and important applications in the field of inorganic non-toxic biocide agents such as medical implants, surgical equipment, protective apparels in hospitals, water purifications systems, food packaging, food storages or textiles.

Antibacterial and Antifungal Activity of ZnO Containing Glasses

PubMed Central

Esteban-Tejeda, Leticia; Prado, Catuxa; Cabal, Belén; Sanz, Jesús; Torrecillas, Ramón; Moya, José Serafín

2015-01-01

A new family of non-toxic biocides based on low melting point (1250°C) transparent glasses with high content of ZnO (15–40wt%) belonging to the miscibility region of the B2O3-SiO2-Na2O-ZnO system has been developed. These glasses have shown an excellent biocide activity (logarithmic reduction >3) against Gram- (E. coli), Gram+ (S. aureus) and yeast (C. krusei); they are chemically stable in different media (distilled water, sea-like water, LB and DMEN media) as well as biocompatible. The cytotoxicity was evaluated by the Neutral Red Uptake using NIH-3T3 (mouse embryonic fibroblast cells) and the cell viability was >80%. These new glasses can be considered in several and important applications in the field of inorganic non-toxic biocide agents such as medical implants, surgical equipment, protective apparels in hospitals, water purifications systems, food packaging, food storages or textiles. PMID:26230940

Microwave assisted synthesis, characterization and biocidal activities of some new chelates of carbazole derived Schiff bases of cadmium and tin metals

NASA Astrophysics Data System (ADS)

Yadav, Manju; Mishra, Neelima; Sharma, Nutan; Chandra, Sulekh; Kumar, Dinesh

2014-11-01

This study is planned to report the advancement of green microwave approach in the fabrication of a new series of biologically potent (N^X, where X = O/S) donor Schiff bases and their cadmium(II) and tin(II) complexes. The ligands and their metal complexes have been characterized in terms of elemental analysis, molar ionic conductance, magnetic moment and spectral (IR, UV-Vis, NMR (1H, 119Sn), FAB-mass, thermal and XRD) data. The data revealed that the ligands coordinated to the metal center via nitrogen and oxygen/sulfur atoms and form an octahedral arrangement of the ligands around central metal atom. All compounds were evaluated for their in vitro antimicrobial activities against two pathogenic bacteria Bacillus subtilis and Escherichia coli and two fungi Aspergillus niger and Aspergillus flavus by standard disc diffusion method. The discs were stored in an incubator at 37 °C. The compounds were dissolved in DMF at 500 and 1000 ppm concentrations for screening biocidal activity. The compounds were dissolved in DMF to get the 100 and 200 ppm concentration of test solutions for screening fungicidal activity. The inhibition zone around each disc was measured (in mm) after 24 h and 96 h for biocidal and fungicidal activities respectively.

Determination of toxic compounds in paper-recycling process waters by gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry.

PubMed

Rigol, A; Latorre, A; Lacorte, S; Barceló, D

2002-07-19

Three analytical methods were developed for the determination of toxic compounds in recirculating waters of a paper-recycling industry. Three main groups of compounds were considered: (i) wood extractives originated from the raw material; (ii) biocides added during the production process and (iii) surfactants and other adjuvants present in the formulates of these biocides. Wood extractives considered in this study included fatty and resin acids. They were analysed by liquid-liquid extraction using methyl tert.-butyl ether, followed by gas chromatography-mass spectrometry for previous formation of the respective trimethylsilyl esters. Water samples were also extracted with Oasis HLB (copolymer [poly(divinylbenzene-co-N-vinylpyrrolidone]) solid-phase extraction cartridges of 60 mg and analysed by liquid chromatography-electrospray mass spectrometry for the determination of additives and biocides. Using these two approaches levels up to 15 mg/l for total resin and fatty acids, 5 mg/l for alkylbenzene sulfonates and 2-(thiocyanomethylthio)benzotiazol, 100 microg/l for bisphenol A and 2,2-dibromo-3-nitrilepropionamide, and 300 microg/l for nonylphenol ethoxycarboxylate were detected in process waters at different production treatment stages. These levels are of relevance since poor water quality affects the paper-recycling process, the primary water treatment process and eventually, the environmental water quality.

Ecological risks of home and personal care products in the riverine environment of a rural region in South China without domestic wastewater treatment facilities.

PubMed

Zhang, Nai-Sheng; Liu, You-sheng; Van den Brink, Paul J; Price, Oliver R; Ying, Guang-Guo

2015-12-01

Home and personal care products (HPCPs) including biocides, benzotriazoles (BTs) and ultraviolet (UV) filters are widely used in our daily life. After use, they are discharged with domestic wastewater into the receiving environment. This study investigated the occurrence of 29 representative HPCPs, including biocides, BTs and UV filters, in the riverine environment of a rural region of South China where no wastewater treatment plants were present, and assessed their potential ecological risks to aquatic organisms. The results showed the detection of 11 biocides and 4 BTs in surface water, and 9 biocides, 3 BTs and 4 UV filters in sediment. In surface water, methylparaben (MeP), triclocarban (TCC), and triclosan (TCS) were detected at all sites with median concentrations of 9.23 ng/L, 2.64 ng/L and 5.39 ng/L, respectively. However, the highest median concentrations were found for clotrimazole (CLOT), 5-methyl-1H-benzotriazole (MBT) and carbendazim (CARB) at 55.6 ng/L, 33.7 ng/L and 13.8 ng/L, respectively. In sediment, TCC, TCS, and UV-326 were detected with their maximum concentrations up to 353 ng/g, 155 ng/g, and 133 ng/g, respectively. The concentrations for those detected HPCPs in surface water and sediment were generally lower in the upper reach (rural area) of Sha River than in the lower reach of Sha River with close proximity to Dongjiang River (Pt-test<0.05), indicating other input sources of HPCPs in the lower reach. Biocides showed significantly higher levels in surface water in the wet season than in the dry and intermediate seasons. Preliminary risk assessment demonstrated that the majority of HPCPs monitored represented low risk in surface waters. There are potentially greater risks to aquatic organisms from the use of TCS and TCC in the wet season than in dry and intermediate seasons in surface waters. This preliminary assessment also indicates potential concerns associated with TCC, TCS, DEET, CARB, and CLOT in sediments, although additional data should be generated to assess this fully. Thus future research is needed to investigate ecological effects of these HPCPs on benthic organisms in sediment of rural rivers receiving untreated wastewater discharge. Copyright © 2015 Elsevier Inc. All rights reserved.

Effectiveness of bromicide against Legionella pneumophila in a cooling tower

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

Fliermans, C.B.; Harvey, R.S.

1983-01-01

Cooling towers are considered to be man-made amplifiers of Legionella. Thus the proper maintenance and choice of biocides is important. The only biocide that has thus far been shown to be effective in field tests is the judicious use of chlorination. Perturbation studies were conducted on an industrial cooling tower shown to contain Legionella, using 1-bromo-3-chloro-5,5-dimethylhydantoin (Bromicide, Great Lakes Chemical Corp.). At the manufacturer's recommended concentrations neither the density nor the activity of Legionella was affected. At concentrations greater than 2.0 ppM free residual, the Bromicide was not effective in reducing Legionella to source water concentrations, nor was it effectivemore » in reducing the INT activity of the bacterium in situ. The data indicate that at concentrations up to 2.0 ppM, Bromicide is not effective in these tower studies. 23 references, 3 tables.« less

Mixed Oxidant Process for Control of Biological Growth in Cooling Towers

DTIC Science & Technology

2010-02-01

Concentration is < 1% (vs. 12.5% for bulk bleach ) • Will not form chlorine gas • No transport or storage of hazardous chemicals • Uses only salt as...Eliminates purchase, transport, and storage of hazardous biocide compounds such as hypochlorite or chlorine gas • Provides a constant dosage level of...patented MIOX equipment design • Chemical and biocidal properties are more effective than conventional chlorine Bulk Bleach On-Site Hypo Mixed Oxidants E

Space Science

NASA Image and Video Library

2003-06-07

The heart of a colorimetric solid phase extractor (CSPE) test kit quickly measures the concentration of the biocides silver or iodine in astronauts’ drinking water to determine whether concentrations are safe. When 10 milliliters (ml) of water is drawn through the disk, the disk will turn color (yellow in this picture for iodine) indicating the presence of the biocides. The device could someday be used to test water safety at reservoirs and water treatment plants on Earth. (photo credit: Microanalytical Instrumentation Center, Iowa State University).

Antifouling booster biocide extraction from marine sediments: a fast and simple method based on vortex-assisted matrix solid-phase extraction.

PubMed

Caldas, Sergiane Souza; Soares, Bruno Meira; Abreu, Fiamma; Castro, Ítalo Braga; Fillmann, Gilberto; Primel, Ednei Gilberto

2018-03-01

This paper reports the development of an analytical method employing vortex-assisted matrix solid-phase dispersion (MSPD) for the extraction of diuron, Irgarol 1051, TCMTB (2-thiocyanomethylthiobenzothiazole), DCOIT (4,5-dichloro-2-n-octyl-3-(2H)-isothiazolin-3-one), and dichlofluanid from sediment samples. Separation and determination were performed by liquid chromatography tandem-mass spectrometry. Important MSPD parameters, such as sample mass, mass of C18, and type and volume of extraction solvent, were investigated by response surface methodology. Quantitative recoveries were obtained with 2.0 g of sediment sample, 0.25 g of C18 as the solid support, and 10 mL of methanol as the extraction solvent. The MSPD method was suitable for the extraction and determination of antifouling biocides in sediment samples, with recoveries between 61 and 103% and a relative standard deviation lower than 19%. Limits of quantification between 0.5 and 5 ng g -1 were obtained. Vortex-assisted MPSD was shown to be fast and easy to use, with the advantages of low cost and reduced solvent consumption compared to the commonly employed techniques for the extraction of booster biocides from sediment samples. Finally, the developed method was applied to real samples. Results revealed that the developed extraction method is effective and simple, thus allowing the determination of biocides in sediment samples.

Triclosan exposure modulates estrogen-dependent responses in the rat uterotrophic assay.

EPA Science Inventory

Our previous studies in the juvenile rat indicated that the biocide triclosan may alter steroid hormone levels. Here, we hypothesize that triclosan possesses estrogenic activity. In the first study, we evaluated the potential estrogenicity of triclosan using the immature rat uter...

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

PubMed

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

2011-01-01

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

Control of corrosive bacterial community by bronopol in industrial water system.

PubMed

Narenkumar, Jayaraman; Ramesh, Nachimuthu; Rajasekar, Aruliah

2018-01-01

Ten aerobic corrosive bacterial strains were isolated from a cooling tower water system (CWS) which were identified based on the biochemical characterization and 16S rRNA gene sequencing. Out of them, dominant corrosion-causing bacteria, namely, Bacillus thuringiensis EN2, Terribacillus aidingensis EN3, and Bacillus oleronius EN9, were selected for biocorrosion studies on mild steel 1010 (MS) in a CWS. The biocorrosion behaviour of EN2, EN3, and EN9 strains was studied using immersion test (weight loss method), electrochemical analysis, and surface analysis. To address the corrosion problems, an anti-corrosive study using a biocide, bronopol was also demonstrated. Scanning electron microscopy and Fourier-transform infrared spectroscopy analyses of the MS coupons with biofilm developed after exposure to CWS confirmed the accumulation of extracellular polymeric substances and revealed that biofilms was formed as microcolonies, which subsequently cause pitting corrosion. In contrast, the biocide system, no pitting type of corrosion, was observed and weight loss was reduced about 32 ± 2 mg over biotic system (286 ± 2 mg). FTIR results confirmed the adsorption of bronopol on the MS metal surface as protective layer (co-ordination of NH 2 -Fe 3+ ) to prevent the biofilm formation and inhibit the corrosive chemical compounds and thus led to reduction of corrosion rate (10 ± 1 mm/year). Overall, the results from WL, EIS, SEM, XRD, and FTIR concluded that bronopol was identified as effective biocide and corrosion inhibitor which controls the both chemical and biocorrosion of MS in CWS.

A Radio Frequency Electric Current Enhances Antibiotic Efficacy against Bacterial Biofilms

PubMed Central

Caubet, R.; Pedarros-Caubet, F.; Chu, M.; Freye, E.; de Belém Rodrigues, M.; Moreau, J. M.; Ellison, W. J.

2004-01-01

Bacterial biofilms are notably resistant to antibiotic prophylaxis. The concentration of antibiotic necessary to significantly reduce the number of bacteria in the biofilm matrix can be several hundred times the MIC for the same bacteria in a planktonic phase. It has been observed that the addition of a weak continuous direct electric current to the liquid surrounding the biofilm can dramatically increase the efficacy of the antibiotic. This phenomenon, known as the bioelectric effect, has only been partially elucidated, and it is not certain that the electrical parameters are optimal. We confirm here the bioelectric effect for Escherichia coli biofilms treated with gentamicin and with oxytetracycline, and we report a new bioelectric effect with a radio frequency alternating electric current (10 MHz) instead of the usual direct current. None of the proposed explanations (transport of ions within the biofilm, production of additional biocides by electrolysis, etc.) of the direct current bioelectric effect are applicable to the radio frequency bioelectric effect. We suggest that this new phenomenon may be due to a specific action of the radio frequency electromagnetic field upon the polar parts of the molecules forming the biofilm matrix. PMID:15561841

Predicting herbicide and biocide concentrations in rivers across Switzerland

NASA Astrophysics Data System (ADS)

Wemyss, Devon; Honti, Mark; Stamm, Christian

2014-05-01

Pesticide concentrations vary strongly in space and time. Accordingly, intensive sampling is required to achieve a reliable quantification of pesticide pollution. As this requires substantial resources, loads and concentration ranges in many small and medium streams remain unknown. Here, we propose partially filling the information gap for herbicides and biocides by using a modelling approach that predicts stream concentrations without site-specific calibration simply based on generally available data like land use, discharge and nation-wide consumption data. The simple, conceptual model distinguishes herbicide losses from agricultural fields, private gardens and biocide losses from buildings (facades, roofs). The herbicide model is driven by river discharge and the applied herbicide mass; the biocide model requires precipitation and the footprint area of urban areas containing the biocide. The model approach allows for modelling concentrations across multiple catchments at the daily, or shorter, time scale and for small to medium-sized catchments (1 - 100 km2). Four high resolution sampling campaigns in the Swiss Plateau were used to calibrate the model parameters for six model compounds: atrazine, metolachlor, terbuthylazine, terbutryn, diuron and mecoprop. Five additional sampled catchments across Switzerland were used to directly compare the predicted to the measured concentrations. Analysis of the first results reveals a reasonable simulation of the concentration dynamics for specific rainfall events and across the seasons. Predicted concentration ranges are reasonable even without site-specific calibration. This indicates the transferability of the calibrated model directly to other areas. However, the results also demonstrate systematic biases in that the highest measured peaks were not attained by the model. Probable causes for these deviations are conceptual model limitations and input uncertainty (pesticide use intensity, local precipitation, etc.). Accordingly, the model will be conceptually improved. This presentation will present the model simulations and compare the performance of the original and the modified model versions. Finally, the model will be applied across approximately 50% of the catchments in the Swiss Plateau, where necessary input data is available and where the model concept can be reasonably applied.

Recent Advances in the Study of Microbiologically Influenced Corrosion

DTIC Science & Technology

1993-01-01

Bacterial Behavior During Biofouling of Surfaces. Proceedings of Biofouling/ Biocorrosion in Water Systems (1992 Symposium American Chemical Society...Enhancement of Biocide Action for Improved Biofouling and Biocorrosion Con- trol. Proceedings of BiofoulinglBiocorrosion in Water Systems (1992 Symposium

Analysis of the proposed EU regulation concerning biocide products and its opportunities for alternative approaches and a toxicology for the 21st century (t4 report).

PubMed

Ferrario, Daniele; Rabbit, Richard R

2012-01-01

On June 12, 2009, the European Commission adopted a proposal for a Regulation concerning the placement on the market and use of biocidal products, which, when it enters into force on January 1, 2013, will repeal and replace Directive 98/8/EC. The main reason for the revision of the current Directive was to promote best practices for environmental and human health protection, along with implementation of current developments in safety testing in order to create safer biocides. Moreover, the proposed Regulation aims to take into consideration the newest legislation on chemicals. This article evaluates the proposed Regulation in comparison to Directive 98/8/EC. Although the new proposal requires the sharing of vertebrate animal test data, both for product authorization and for newly developed active substances, it misses - in contrast to REACH - the opportunity to recognize the accelerating development of alternative approaches to animal testing, most recently with new momentum provided by "Toxicity Testing for the 21st Century", and to support the evolution of toxicology towards a new approach to testing. The new methods promise not only to decrease animal pain and suffering, but also to provide faster results and better prediction for human risk assessment compared to traditional methods. Unfortunately, methods mandated for human risk assessment in the proposal are still mainly based on traditional animal study extrapolation. We put forward and discuss possible alternative strategies, such as in vitro testing, integrated testing strategies, toxicokinetics, "omics", systems biology, bioinformatics, and computational modeling, all of which could be more encouraged by the proposal. Current opportunities to improve our tools for biocide risk assessment are discussed, delineating advantages, limitations, and development needs. It is suggested to open the proposed Regulation to alternative approaches that are based on human biology more than on extrapolation from animals to humans.

Toxicity of antifouling biocides to the intertidal harpacticoid copepod Tigriopus japonicus (Crustacea, Copepoda): effects of temperature and salinity.

PubMed

Kwok, K W H; Leung, K M Y

2005-01-01

Intertidal harpacticoid copepods are commonly used in eco-toxicity tests worldwide. They predominately live in mid-high shore rock pools and often experience a wide range of temperature and salinity fluctuation. Most eco-toxicity tests are conducted at fixed temperature and salinity and thus the influence of these environmental factors on chemical toxicity is largely unknown. This study investigated the combined effect of temperature and salinity on the acute toxicity of the copepod Tigriopus japonicus against two common biocides, copper (Cu) and tributyltin (TBT) using a 2 x 3 x 4 factorial design (i.e. two temperatures: 25 and 35 degrees C; three salinities: 15.0 per thousand, 34.5 per thousand and 45.0 per thousand; three levels of the biocide plus a control). Copper sulphate and tributyltin chloride were used as the test chemicals while distilled water and acetone were utilised as solvents for Cu and TBT respectively. 96 h-LC50s of Cu and TBT were 1024 and 0.149 microg l(-1) respectively (at 25 degrees C; 34.5 per thousand) and, based on these results, nominal biocide concentrations of LC0 (i.e. control), LC30, LC50 and LC70 were employed. Analysis of Covariance using 'concentration' as the covariate and both 'temperature' and 'salinity' as fixed factors, showed a significant interaction between temperature and salinity effects for Cu, mortality increasing with temperature but decreasing with elevated salinity. A similar result was revealed for TBT. Both temperature and salinity are, therefore, important factors affecting the results of acute eco-toxicity tests using these marine copepods. We recommend that such eco-toxicity tests should be conducted at a range of environmentally realistic temperature/salinity regimes, as this will enhance the sensitivity of the test and improve the safety margin in line with the precautionary principle.

In-depth resistome analysis by targeted metagenomics.

PubMed

Lanza, Val F; Baquero, Fernando; Martínez, José Luís; Ramos-Ruíz, Ricardo; González-Zorn, Bruno; Andremont, Antoine; Sánchez-Valenzuela, Antonio; Ehrlich, Stanislav Dusko; Kennedy, Sean; Ruppé, Etienne; van Schaik, Willem; Willems, Rob J; de la Cruz, Fernando; Coque, Teresa M

2018-01-15

Antimicrobial resistance is a major global health challenge. Metagenomics allows analyzing the presence and dynamics of "resistomes" (the ensemble of genes encoding antimicrobial resistance in a given microbiome) in disparate microbial ecosystems. However, the low sensitivity and specificity of available metagenomic methods preclude the detection of minority populations (often present below their detection threshold) and/or the identification of allelic variants that differ in the resulting phenotype. Here, we describe a novel strategy that combines targeted metagenomics using last generation in-solution capture platforms, with novel bioinformatics tools to establish a standardized framework that allows both quantitative and qualitative analyses of resistomes. We developed ResCap, a targeted sequence capture platform based on SeqCapEZ (NimbleGene) technology, which includes probes for 8667 canonical resistance genes (7963 antibiotic resistance genes and 704 genes conferring resistance to metals or biocides), and 2517 relaxase genes (plasmid markers) and 78,600 genes homologous to the previous identified targets (47,806 for antibiotics and 30,794 for biocides or metals). Its performance was compared with metagenomic shotgun sequencing (MSS) for 17 fecal samples (9 humans, 8 swine). ResCap significantly improves MSS to detect "gene abundance" (from 2.0 to 83.2%) and "gene diversity" (26 versus 14.9 genes unequivocally detected per sample per million of reads; the number of reads unequivocally mapped increasing up to 300-fold by using ResCap), which were calculated using novel bioinformatic tools. ResCap also facilitated the analysis of novel genes potentially involved in the resistance to antibiotics, metals, biocides, or any combination thereof. ResCap, the first targeted sequence capture, specifically developed to analyze resistomes, greatly enhances the sensitivity and specificity of available metagenomic methods and offers the possibility to analyze genes related to the selection and transfer of antimicrobial resistance (biocides, heavy metals, plasmids). The model opens the possibility to study other complex microbial systems in which minority populations play a relevant role.

Ignition, Combustion and Tuning of Nanocomposite Thermites

DTIC Science & Technology

2010-01-01

8.2.10. The linescan indicates that an Ag/ Cu matrix is in surface contact with Al and O (assumed to be Al2O3). It is speculated the morphology is...chemical reaction. Generally, these are loose powders Al2O3 Al 3 As prepared, these are generally loose been used as the fuel, due to a...considered recently for its potential use in thermite-based biocidal applications.116 Silver exhibits biocidal properties in many forms.117 Morones et al

Evaluation of Biofilms and the Effects of Biocides Thereon

NASA Technical Reports Server (NTRS)

Pierson, Duane L. (Inventor); Koenig, David W. (Inventor); Mishra, Saroj K. (Inventor)

2002-01-01

Biofilm formation is monitored by real-time continuous measurement. Images are formed of sessile cells on a surface and planktonic cells adjacent the surface. The attachment of cells to the surface is measured and quantitated, and sessile and planktonic cells are distinguished using image processing techniques. Single cells as well as colonies are monitored on or adjacent a variety of substrates. Flowing streams may be monitored. The effects of biocides on biofilms commonly isolated from recyclable water systems are measured.

Rhamnolipids from non-pathogenic Burkholderia thailandensis E264: Physicochemical characterization, antimicrobial and antibiofilm efficacy against oral hygiene related pathogens.

PubMed

Elshikh, Mohamed; Funston, Scott; Chebbi, Alif; Ahmed, Syed; Marchant, Roger; Banat, Ibrahim M

2017-05-25

Biosurfactants are naturally occurring surface active compounds that have mainly been exploited for environmental applications and consumer products, with their biomedical efficacy an emerging area of research. Rhamnolipids area major group of biosurfactants that have been reported for their antimicrobial and antibiofilm efficacy. One of the main limiting factors for scaled up production and downstream applications of rhamnolipids is the fact that they are predominantly produced from the opportunistic pathogen Pseudomonas aeruginosa. In this article, we have reported the production and characterisation of long chain rhamnolipids from non-pathogenic Burkholderia thailandensis E264 (ATCC 700388). We have also investigated the antibacterial and antibiofilm properties of these rhamnolipids against some oral pathogens (Streptococcus oralis, Actinomyces naeslundii, Neisseria mucosa and Streptococcus sanguinis), important for oral health and hygiene. Treating these bacteria with different concentrations of long chain rhamnolipids resulted in a reduction of 3-4 log of bacterial viability, placing these rhamnolipids close to being classified as biocidal. Investigating long chain rhamnolipid efficacy as antibiofilm agents for prospective oral-related applications revealed good potency against oral-bacteria biofilms in a co-incubation experiments, in a pre-coated surface format, in disrupting immature biofilms and has shown excellent combination effect with Lauryl Sodium Sulphate which resulted in a drastic decrease in its minimal inhibitory concentration against different bacteria. Investigating the rhamnolipid permeabilization effect along with their ability to induce the formation of reactive oxygen species has shed light on the mechanism through which inhibition/killing of bacteria may occur. Copyright © 2017 Elsevier B.V. All rights reserved.

Size- and shape-dependent clinical and mycological efficacy of silver nanoparticles on dandruff.

PubMed

Anwar, Mohammad F; Yadav, Deepak; Jain, Swati; Kapoor, Sumeet; Rastogi, Shweta; Arora, Indu; Samim, Mohammed

2016-01-01

Dandruff is a prominent scalp problem caused by the growth of fungus Malassezia furfur, potentially cascading into dermal inflammation, itching, and tissue damage. The present work outlines a detailed analysis of the treatment of scalp infection using silver nanomaterials (Ag NMs), and focuses on biocidal activity owing to manipulation of size, shape, and structure. Monodisperse silver spherical nanoparticles (NPs) and nanorods (NRs) were synthesized by chemical routes that were characterized using analytical and spectroscopic techniques. Ag NMs demonstrated enhanced biocidal tendencies compared to market available drugs, itracanozole and ketoconazole, showing greater zones of inhibition. The obtained 20 nm and 50 nm spherical-shaped NPs and 50 nm NRs showed concentration-, size-, and shape-dependent antifungal activity, with 20 nm spherical-shaped NPs exhibiting excellent potency. Minimum inhibitory concentration for 20 nm was lowest at 0.2 mg/mL in comparison to 0.3 mg/mL for NRs. Primary irritation index was 0.33 and 0.16 for 20 nm and 50 nm spherical-shaped NPs, respectively, while 50 nm rod-shaped NMs exhibited negligible redness. An in vivo model for M. furfur infection was generated by passing fungi subcutaneously in rats' skin. Again, 20 nm particles showed best normalization of skin after 10 days on regular dosing, in comparison with bigger and rod-shaped particles. The statistical clinical score was highest for Ag nanorods, followed by 50 nm Ag NPs-treated animals. It was observed that 20 nm spherical particles exhibited the lowest score (0) compared with others as well as with antifungal drugs. Biochemical analysis performed by checking antioxidant enzymatic activities indicated tissue repair and normalization of enzymes and protein concentration by Ag NPs.

Size- and shape-dependent clinical and mycological efficacy of silver nanoparticles on dandruff

PubMed Central

Anwar, Mohammad F; Yadav, Deepak; Jain, Swati; Kapoor, Sumeet; Rastogi, Shweta; Arora, Indu; Samim, Mohammed

2016-01-01

Dandruff is a prominent scalp problem caused by the growth of fungus Malassezia furfur, potentially cascading into dermal inflammation, itching, and tissue damage. The present work outlines a detailed analysis of the treatment of scalp infection using silver nanomaterials (Ag NMs), and focuses on biocidal activity owing to manipulation of size, shape, and structure. Monodisperse silver spherical nanoparticles (NPs) and nanorods (NRs) were synthesized by chemical routes that were characterized using analytical and spectroscopic techniques. Ag NMs demonstrated enhanced biocidal tendencies compared to market available drugs, itracanozole and ketoconazole, showing greater zones of inhibition. The obtained 20 nm and 50 nm spherical-shaped NPs and 50 nm NRs showed concentration-, size-, and shape-dependent antifungal activity, with 20 nm spherical-shaped NPs exhibiting excellent potency. Minimum inhibitory concentration for 20 nm was lowest at 0.2 mg/mL in comparison to 0.3 mg/mL for NRs. Primary irritation index was 0.33 and 0.16 for 20 nm and 50 nm spherical-shaped NPs, respectively, while 50 nm rod-shaped NMs exhibited negligible redness. An in vivo model for M. furfur infection was generated by passing fungi subcutaneously in rats’ skin. Again, 20 nm particles showed best normalization of skin after 10 days on regular dosing, in comparison with bigger and rod-shaped particles. The statistical clinical score was highest for Ag nanorods, followed by 50 nm Ag NPs-treated animals. It was observed that 20 nm spherical particles exhibited the lowest score (0) compared with others as well as with antifungal drugs. Biochemical analysis performed by checking antioxidant enzymatic activities indicated tissue repair and normalization of enzymes and protein concentration by Ag NPs. PMID:26792991

Pseudomonas aeruginosa adapts to octenidine in the laboratory and a simulated clinical setting, leading to increased tolerance to chlorhexidine and other biocides.

PubMed

Shepherd, M J; Moore, G; Wand, M E; Sutton, J M; Bock, L J

2018-03-31

Octenidine is frequently used for infection prevention in neonatal and burn intensive care units, where Pseudomonas aeruginosa has caused nosocomial outbreaks. To investigate the efficacy and impact of using octenidine against P. aeruginosa. Seven clinical isolates of P. aeruginosa were exposed to increasing concentrations of octenidine over several days. Fitness, minimum bactericidal concentrations after 1 min, 5 min and 24 h, and minimum inhibitory concentrations (MICs) of a variety of antimicrobials were measured for the parental and octenidine-adapted P. aeruginosa strains. Octenidine and chlorhexidine MICs of a population of P. aeruginosa isolated from a hospital drain trap, exposed to a diluted octenidine formulation four times daily for three months, were also tested. Some planktonic cultures of P. aeruginosa survived >50% of the working concentration of an in-use octenidine formulation at the recommended exposure time. Seven strains of P. aeruginosa stably adapted following continuous exposure to increasing concentrations of octenidine. Adaptation increased tolerance to octenidine formulations and chlorhexidine up to 32-fold. In one strain, it also led to increased MICs of antipseudomonal drugs. Subsequent to continuous octenidine exposure of a multi-species community in a simulated clinical setting, up to eight-fold increased tolerance to octenidine and chlorhexidine of P. aeruginosa was also found, which was lost upon removal of octenidine. Incorrect use of octenidine formulations may lead to inadequate decontamination, and even increased tolerance of P. aeruginosa to octenidine, with resulting cross-resistance to other biocides. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Emission of biocides from hospitals: comparing current survey results with European Union default values.

PubMed

Tluczkiewicz, Inga; Bitsch, Annette; Hahn, Stefan; Hahn, Torsten

2010-04-01

Under the European Union (EU) Biocidal Products Directive 98/8/EC, comprehensive evaluations on substances of the Third Priority List were conducted until 31 July 2007. This list includes, among other categories, disinfectants for human hygiene (e.g., skin and surface disinfection). For environmental exposure assessment of biocides, the EU emission scenarios apply. Currently available default values for disinfectants are based on consumption data from not more than 8 hospitals and were originally assembled for other purposes. To revalidate these default values, a survey on annual consumption data was performed in 27 German hospitals. These data were analyzed to provide consumption data per bed and day and per nurse and day for particular categories of active ingredients and were compared with default values from the EU emission scenario documents. Although several deviations were detected, an overall acceptable correspondence between Emission Scenario Documents default values and the current survey data was found. (c) 2009 SETAC

Long-term changes in Prosobranchia (Gastropoda) abundances on the German North Sea coast: the role of the anti-fouling biocide tributyltin

NASA Astrophysics Data System (ADS)

Nehring, S.

2000-05-01

Tributyltin (TBT) has been used as a biocide in marine anti-fouling paints since the early 1970s. Due to its strong ecotoxicity and the relatively high levels in the water column as well as in port sediments on the German North Sea coast, it probably has negative ecological effects on organisms other than those targeted. An analysis of the long-term development of prosobranch stocks in the inner German Bight reveals a decrease in abundance of many species. For most species the decline cannot be attributed to TBT, but in four prosobranch species ( Buccinum undatum, Hydrobia ulvae, Littorina littorea and Nucella lapillus) significant ecological effects by TBT pollution are very probable. Although research for alternative non-TBT anti-fouling paints (e.g. biocide-free types on the basis of silicone) has been intensified, the potential threats to ecosystems and the ecotoxicological profiles of these alternatives have to be carefully evaluated.

Assessment of TBT and organic booster biocide contamination in seawater from coastal areas of South Korea.

PubMed

Kim, Nam Sook; Shim, Won Joon; Yim, Un Hyuk; Hong, Sang Hee; Ha, Sung Yong; Han, Gi Myung; Shin, Kyung-Hoon

2014-01-15

Seawater samples from major enclosed bays, fishing ports, and harbors of Korea were analyzed to determine levels of tributyltin (TBT) and booster biocides, which are antifouling agents used as alternatives to TBT. TBT levels were in the range of not detected (nd) to 23.9 ng Sn/L. Diuron and Irgarol 1051, at concentration ranges of 35-1360 ng/L and nd to 14 ng/L, respectively, were the most common alternative biocides present in seawater, with the highest concentrations detected in fishing ports. Hot spots were identified where TBT levels exceeded environmental quality targets even 6 years after a total ban on its use in Korea. Diuron exceeded the UK environmental quality standard (EQS) value in 73% of the fishing port samples, 64% of the major bays, and 42% of the harbors. Irgarol 1051 levels were marginally below the Dutch and UK EQS values at all sites. Copyright © 2013 Elsevier Ltd. All rights reserved.

FAST TRACK COMMUNICATION: Plasma agents in bio-decontamination by dc discharges in atmospheric air

NASA Astrophysics Data System (ADS)

Machala, Zdenko; Chládeková, Lenka; Pelach, Michal

2010-06-01

Bio-decontamination of water and surfaces contaminated by bacteria (Salmonella typhimurium) was investigated in two types of positive dc discharges in atmospheric pressure air, in needle-to-plane geometry: the streamer corona and its transition to a novel regime called transient spark with short high current pulses of limited energy. Both generate a cold non-equilibrium plasma. Electro-spraying of treated water through a needle electrode was applied for the first time and resulted in fast bio-decontamination. Experiments providing separation of various biocidal plasma agents, along with the emission spectra and coupled with oxidation stress measurements in the cell membranes helped to better understand the mechanisms of microbial inactivation. The indirect exposure of contaminated surfaces to neutral active species was almost as efficient as the direct exposure to the plasma, whereas applying only UV radiation from the plasma had no biocidal effects. Radicals and reactive oxygen species were identified as dominant biocidal agents.

Microwave assisted synthesis, characterization and biocidal activities of some new chelates of carbazole derived Schiff bases of cadmium and tin metals.

PubMed

Yadav, Manju; Mishra, Neelima; Sharma, Nutan; Chandra, Sulekh; Kumar, Dinesh

2014-11-11

This study is planned to report the advancement of green microwave approach in the fabrication of a new series of biologically potent (N^X, where X=O/S) donor Schiff bases and their cadmium(II) and tin(II) complexes. The ligands and their metal complexes have been characterized in terms of elemental analysis, molar ionic conductance, magnetic moment and spectral (IR, UV-Vis, NMR ((1)H, (119)Sn), FAB-mass, thermal and XRD) data. The data revealed that the ligands coordinated to the metal center via nitrogen and oxygen/sulfur atoms and form an octahedral arrangement of the ligands around central metal atom. All compounds were evaluated for their in vitro antimicrobial activities against two pathogenic bacteria Bacillus subtilis and Escherichia coli and two fungi Aspergillus niger and Aspergillus flavus by standard disc diffusion method. The discs were stored in an incubator at 37°C. The compounds were dissolved in DMF at 500 and 1000 ppm concentrations for screening biocidal activity. The compounds were dissolved in DMF to get the 100 and 200 ppm concentration of test solutions for screening fungicidal activity. The inhibition zone around each disc was measured (in mm) after 24 h and 96 h for biocidal and fungicidal activities respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

The toxicity of the three antifouling biocides DCOIT, TPBP and medetomidine to the marine pelagic copepod Acartia tonsa.

PubMed

Wendt, Ida; Backhaus, Thomas; Blanck, Hans; Arrhenius, Åsa

2016-07-01

Copepods, the largest group of pelagic grazers, are at risk from exposure to antifouling biocides. This study investigated the toxicity of the antifouling biocides 4,5-dichloro-2-octyl-1,2-thiazol-3(2H)-one (DCOIT), triphenylborane pyridine (TPBP) and 4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (medetomidine) to the copepod Acartia tonsa, using mortality and egg production as endpoints. The toxicity ranking for mortality was as follows: DCOIT (LC50 57 nmol l(-1)) = TPBP (LC50 56 nmol l(-1)) > medetomidine (LC50 241 nmol l(-1)). Egg production was more sensitive than mortality to TPBP (EC50 3.2 nmol l(-1)), while DCOIT and medetomidine inhibited egg production at roughly the same concentrations (72 and 186 nmol l(-1) respectively). Furthermore, TPBP seems to affect egg hatching directly which was not the case for DCOIT and medetomidine. DCOIT and medetomidine might pose an environmental risk as they have been reported to occur in different exposure scenarios or analytical surveys at concentrations only 2-3 times lower than the respective EC10. Reported environmental concentrations of TPBP are few but clearly lower than the EC10 values reported here, suggesting current risk of TPBP to copepods to be moderate.

Fibrous Catalyst-Enhanced Acanthamoeba Disinfection by Hydrogen Peroxide.

PubMed

Kilvington, Simon; Winterton, Lynn

2017-11-01

Hydrogen peroxide (H2O2) disinfection systems are contact-lens-patient problem solvers. The current one-step, criterion-standard version has been widely used since the mid-1980s, without any significant improvement. This work identifies a potential next-generation, one-step H2O2, not based on the solution formulation but rather on a case-based peroxide catalyst. One-step H2O2 systems are widely used for contact lens disinfection. However, antimicrobial efficacy can be limited because of the rapid neutralization of the peroxide from the catalytic component of the systems. We studied whether the addition of an iron-containing catalyst bound to a nonfunctional propylene:polyacryonitrile fabric matrix could enhance the antimicrobial efficacy of these one-step H2O2 systems. Bausch + Lomb PeroxiClear and AOSept Plus (both based on 3% H2O2 with a platinum-neutralizing disc) were the test systems. These were tested with and without the presence of the catalyst fabric using Acanthamoeba cysts as the challenge organism. After 6 hours' disinfection, the number of viable cysts was determined. In other studies, the experiments were also conducted with biofilm formed by Stenotrophomonas maltophilia and Elizabethkingia meningoseptica bacteria. Both control systems gave approximately 1-log10 kill of Acanthamoeba cysts compared with 3.0-log10 kill in the presence of the catalyst (P < .001). In the biofilm studies, no viable bacteria were recovered following disinfection in the presence of the catalyst compared with ≥3.0-log10 kill when it was omitted. In 30 rounds' recurrent usage, the experiments, in which the AOSept Plus system was subjected to 30 rounds of H2O2 neutralization with or without the presence of catalytic fabric, showed no loss in enhanced biocidal efficacy of the material. The catalytic fabric was also shown to not retard or increase the rate of H2O2 neutralization. We have demonstrated the catalyst significantly increases the efficacy of one-step H2O2 disinfection systems using highly resistant Acanthamoeba cysts and bacterial biofilm. Incorporating the catalyst into the design of these one-step H2O2 disinfection systems could improve the antimicrobial efficacy and provide a greater margin of safety for contact lens users.

Commercial Biocides Induce Transfer of Prophage Φ13 from Human Strains of Staphylococcus aureus to Livestock CC398.

PubMed

Tang, Yuanyue; Nielsen, Lene N; Hvitved, Annemette; Haaber, Jakob K; Wirtz, Christiane; Andersen, Paal S; Larsen, Jesper; Wolz, Christiane; Ingmer, Hanne

2017-01-01

Human strains of Staphylococcus aureus commonly carry the bacteriophage ΦSa3 that encodes immune evasion factors. Recently, this prophage has been found in livestock-associated, methicillin resistant S. aureus (MRSA) CC398 strains where it may promote human colonization. Here, we have addressed if exposure to biocidal products induces phage transfer, and find that during co-culture, Φ13 from strain 8325, belonging to ΦSa3 group, is induced and transferred from a human strain to LA-MRSA CC398 when exposed to sub-lethal concentrations of commercial biocides containing hydrogen peroxide. Integration of ΦSa3 in LA-MRSA CC398 occurs at multiple positions and the integration site influences the stability of the prophage. We did not observe integration in hlb encoding β-hemolysin that contains the preferred ΦSa3 attachment site in human strains, and we demonstrate that this is due to allelic variation in CC398 strains that disrupts the phage attachment site, but not the expression of β-hemolysin. Our results show that hydrogen peroxide present in biocidal products stimulate transfer of ΦSa3 from human to LA-MRSA CC398 strains and that in these strains prophage stability depends on the integration site. Knowledge of ΦSa3 transfer and stability between human and livestock strains may lead to new intervention measures directed at reducing human infection by LA-MRSA strains.

Commercial Biocides Induce Transfer of Prophage Φ13 from Human Strains of Staphylococcus aureus to Livestock CC398

PubMed Central

Tang, Yuanyue; Nielsen, Lene N.; Hvitved, Annemette; Haaber, Jakob K.; Wirtz, Christiane; Andersen, Paal S.; Larsen, Jesper; Wolz, Christiane; Ingmer, Hanne

2017-01-01

Human strains of Staphylococcus aureus commonly carry the bacteriophage ΦSa3 that encodes immune evasion factors. Recently, this prophage has been found in livestock-associated, methicillin resistant S. aureus (MRSA) CC398 strains where it may promote human colonization. Here, we have addressed if exposure to biocidal products induces phage transfer, and find that during co-culture, Φ13 from strain 8325, belonging to ΦSa3 group, is induced and transferred from a human strain to LA-MRSA CC398 when exposed to sub-lethal concentrations of commercial biocides containing hydrogen peroxide. Integration of ΦSa3 in LA-MRSA CC398 occurs at multiple positions and the integration site influences the stability of the prophage. We did not observe integration in hlb encoding β-hemolysin that contains the preferred ΦSa3 attachment site in human strains, and we demonstrate that this is due to allelic variation in CC398 strains that disrupts the phage attachment site, but not the expression of β-hemolysin. Our results show that hydrogen peroxide present in biocidal products stimulate transfer of ΦSa3 from human to LA-MRSA CC398 strains and that in these strains prophage stability depends on the integration site. Knowledge of ΦSa3 transfer and stability between human and livestock strains may lead to new intervention measures directed at reducing human infection by LA-MRSA strains. PMID:29270158

Characterization of Electrochemically Generated Silver

NASA Technical Reports Server (NTRS)

Adam, Niklas; Martinez, James; Carrier, Chris

2014-01-01

Silver biocide offers a potential advantage over iodine, the current state of the art in US spacecraft disinfection technology, in that silver can be safely consumed by the crew. Low concentrations of silver (<500 ppb) have been shown to kill bacteria in water systems and keep it safe for potability. Silver does not require hardware to remove it from a water system, and therefore can provide a simpler means for disinfecting water. The Russian segment of the International Space Station has utilized an electrochemically generated silver solution, which is colloidal in nature. To be able to reliably provide a silver biocide to drinking water by electrochemical means would reduce mass required for removing another biocide such as iodine from the water. This would also aid in crew time required to replace iodine removal cartridges. Future long term missions would benefit from electrochemically produced silver as the biocide could be produced on demand and requires only a small concentration to be effective. Since it can also be consumed safely, there is less mass in removal hardware and little consumables required for production. The goal of this project initially is to understand the nature of the electrochemically produced silver, the particle sizes produced by the electrochemical cell and the effect that voltage adjustment has on the particle size. In literature, it has been documented that dissolved oxygen and pH have an effect on the ionization of the electrochemical silver so those parameters would be measured and possibly adjusted to understand their effect on the silver.

Biocidal efficacy of monochloramine against planktonic and biofilm-associated Naegleria fowleri cells.

PubMed

Goudot, S; Herbelin, P; Mathieu, L; Soreau, S; Banas, S; Jorand, F P A

2014-04-01

Free-living amoebae (FLA) in aqueous systems are a problem for water network managers and health authorities because some are pathogenic, such as Naegleria fowleri, and they have also been reported to operate as reservoirs and vectors of several pathogenic bacteria. Therefore, to better control the occurrence of such amoebae, we evaluate the efficacy of monochloramine against planktonic forms (trophozoites and cysts) and also biofilm-associated cells of N. fowleri as FLA are often associated with biofilms. From a freshwater biofilm growing in a pilot reactor and inoculated with N. fowleri, we obtained Ct values ranging from 4 to 17 mg Cl2 min l(-1) at 25°C and pH 8·2 on both planktonic and biofilm associated cells. In addition, the inactivation pattern of biofilm associated was intermediate between those of trophozoïtes and cysts. The monochloramine efficiency varies with the life stage of N. fowleri (trophozoïte, cyst, and biofilm-associated). The sensitivity to disinfectant of amoeba, that is, trophozoïtes and cysts, in the biofilm life stage is as high as that of their planktonic cyst form. This study gives Ct values for cysts and biofilm-associated N. fowleri. This may impact on water treatment strategies against amoebae and should be considered when controlling N. fowleri in man-made water systems such as cooling towers or hot water systems. © 2014 The Society for Applied Microbiology.

Occurrence and overlooked sources of the biocide carbendazim in wastewater and surface water.

PubMed

Merel, Sylvain; Benzing, Saskia; Gleiser, Carolin; Di Napoli-Davis, Gina; Zwiener, Christian

2018-08-01

Carbendazim is a fungicide commonly used as active substance in plant protection products and biocidal products, for instance to protect facades of buildings against fungi. However, the subsequent occurrence of this fungicide and potential endocrine disruptor in the aqueous environment is a major concern. In this study, high resolution mass spectrometry shows that carbendazim can be detected with an increasing abundance from the source to the mouth of the River Rhine. Unexpectedly, the abundance of carbendazim correlates poorly with that of other fungicides used as active ingredients in plant protection products (r 2 of 0.32 for cyproconazole and r 2 of 0.57 for propiconazole) but it correlates linearly with that of pharmaceuticals (r 2 of 0.86 for carbamazepine and r 2 of 0.89 for lamotrigine). These results suggest that the occurrence of carbendazim in surface water comes mainly from the discharge of treated domestic wastewater. This hypothesis is further confirmed by the detection of carbendazim in wastewater effluents (n = 22). In fact, bench-scale leaching tests of textiles and papers revealed that these materials commonly found in households could be a source of carbendazim in domestic wastewater. Moreover, additional river samples collected nearby two paper industries indicate that the discharge of their treated process effluents is also a source of carbendazim in the environment. While characterizing paper and textile as overlooked sources of carbendazim, this study also shows the biocide as a possible ubiquitous wastewater contaminant that would require further systematic and worldwide monitoring due to its toxicological properties. Copyright © 2018 Elsevier Ltd. All rights reserved.

Monitoring the performance of innovative and traditional biocides mixed with consolidants and water-repellents for the prevention of biological growth on stone.

PubMed

Pinna, Daniela; Salvadori, Barbara; Galeotti, Monica

2012-04-15

In this study, some mixtures of consolidants or water-repellent products and biocides developed to prevent biological growth, were tested over time on three stone substrates with different bioreceptivity. The performance of both traditional (tetraethylorthosilicate, methylethoxy polysiloxane, Paraloid B72, tributyltin oxide, dibutyltin dilaurate) and innovative compounds (copper nanoparticles) was assessed using colour measurements, the water absorption by contact sponge method, and observation under stereo and optical microscopes. The application of the mixtures had also the purpose of controlling re-colonization on stone after a conservation treatment. The study site was the archaeological Area of Fiesole; the mixtures were applied in situ to sandstone, marble and plaster which had been cleaned beforehand. An innovative aspect of the study is that, by using non-invasive methods, it also permitted monitoring the mixtures' effectiveness in preventing biological growth. The monitoring results made it possible to assess the bioreceptivity of the treated stones (sandstone, marble, plaster) over a period of almost three years. The results showed that the mixtures of consolidants or water-repellent products with biocides were effective in preventing biological growth on both a substrate with low bioreceptivity like plaster and a substrate with high bioreceptivity such as marble. The innovative mixture of nano-Cu particles with a water-repellent yielded good results in terms of preventing biological colonization. Moreover, they apparently did not affect the substrates' colour. Mixtures of nano-Cu particles with a consolidant and a water-repellent hold great promise for preventing re-colonization of stone after conservation treatment. Copyright © 2012 Elsevier B.V. All rights reserved.

Reduction of health care-associated infection indicators by copper oxide-impregnated textiles: Crossover, double-blind controlled study in chronic ventilator-dependent patients.

PubMed

Marcus, Esther-Lee; Yosef, Hana; Borkow, Gadi; Caine, Yehezkel; Sasson, Ady; Moses, Allon E

2017-04-01

Copper oxide has potent wide-spectrum biocidal properties. The purpose of this study is to determine if replacing hospital textiles with copper oxide-impregnated textiles reduces the following health care-associated infection (HAI) indicators: antibiotic treatment initiation events (ATIEs), fever days, and antibiotic usage in hospitalized chronic ventilator-dependent patients. A 7-month, crossover, double-blind controlled trial including all patients in 2 ventilator-dependent wards in a long-term care hospital. For 3 months (period 1), one ward received copper oxide-impregnated textiles and the other received untreated textiles. After a 1-month washout period of using regular textiles, for 3 months (period 2) the ward that received the treated textiles received the control textiles and vice versa. The personnel were blinded to which were treated or control textiles. There were no differences in infection control measures during the study. There were reductions of 29.3% (P = .002), 55.5% (P < .0001), 23.0% (P < .0001), and 27.5% (P < .0001) in the ATIEs, fever days (>37.6°C), days of antibiotic treatment, and antibiotic defined daily dose per 1,000 hospitalization days, respectively, when using the copper oxide-impregnated textiles. Use of copper oxide-impregnated biocidal textiles in a long-term care ward of ventilator-dependent patients was associated with a significant reduction of HAI indicators and antibiotic utilization. Using copper oxide-impregnated biocidal textiles may be an important measure aimed at reducing HAIs in long-term care medical settings. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Regenerable Iodine Water-Disinfection System

NASA Technical Reports Server (NTRS)

Sauer, Richard L.; Colombo, Gerald V.; Jolly, Clifford D.

1994-01-01

Iodinated resin bed for disinfecting water regenerated to extend its useful life. Water flows through regeneration bed of crystalline iodine during regeneration. At other times, flow diverted around regeneration bed. Although regeneration cycle was manually controlled in demonstration, readily automated to start and stop according to signals and stop according to signals from concentration sensors. Further benefit of regeneration is that regeneration bed provides highly concentrated biocide source (200 mg/L) when needed. Concentrated biocide used to superiodinate system after contamination from routine maintenance or unexpected introduction of large concentration of microbes.

Biocidal treatment and preservation of liquid fuels

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

Siegert, W.

1995-05-01

Strict microbiological limit values are the result of damage caused by microorganisms in fuels. With MAR 71, a biocide based on methylenebisoxazolidine, a product is available which has been tested and approved by leading car manufacturers, the mineral oil industry, and NATO. Depending on the degree of microbiological contamination, different decontamination concepts are presented, and recommendations for the treatment of fuels which are contaminated when purchased are given. In order to avoid recontamination, planning principles or the new design of tanks are necessary. The possibility of convenient, economical and regular drainage is a key factor.

The microbiology of Lascaux Cave.

PubMed

Bastian, F; Jurado, V; Nováková, A; Alabouvette, C; Saiz-Jimenez, C

2010-03-01

Lascaux Cave (Montignac, France) contains paintings from the Upper Paleolithic period. Shortly after its discovery in 1940, the cave was seriously disturbed by major destructive interventions. In 1963, the cave was closed due to algal growth on the walls. In 2001, the ceiling, walls and sediments were colonized by the fungus Fusarium solani. Later, black stains, probably of fungal origin, appeared on the walls. Biocide treatments, including quaternary ammonium derivatives, were extensively applied for a few years, and have been in use again since January 2008. The microbial communities in Lascaux Cave were shown to be composed of human-pathogenic bacteria and entomopathogenic fungi, the former as a result of the biocide selection. The data show that fungi play an important role in the cave, and arthropods contribute to the dispersion of conidia. A careful study on the fungal ecology is needed in order to complete the cave food web and to control the black stains threatening the Paleolithic paintings.

Why does Kevlar decompose, while Nomex does not, when treated with aqueous chlorine solutions?

PubMed

Akdag, Akin; Kocer, Hasan B; Worley, S D; Broughton, R M; Webb, T R; Bray, Travis H

2007-05-24

Kevlar and Nomex are high-performance polymers which have wide varieties of applications in daily life. Recently, they have been proposed to be biocidal materials when reacted with household bleach (sodium hypochlorite solution) because they contain amide moieties which can be chlorinated to generate biocidal N-halamine functional groups. Although Nomex can be chlorinated without any significant decomposition, Kevlar decomposes under the same chlorination conditions. In this study, two mimics for each of the polymers were synthesized to simulate the carboxylate and diaminophenylene components of the materials. It was found that the p-diaminophenylene component of the Kevlar mimic is oxidized to a quinone-type structure upon treatment with hypochlorous acid, which then decomposes. However, such a mechanism for the Nomex mimic is not possible. In this paper, based upon these observations, a plausible answer will be provided to the title question.

Susceptibility of vancomycin-resistant and -sensitive Enterococcus faecium obtained from Danish hospitals to benzalkonium chloride, chlorhexidine and hydrogen peroxide biocides.

PubMed

Alotaibi, Sulaiman M I; Ayibiekea, Alafate; Pedersen, Annemette Frøling; Jakobsen, Lotte; Pinholt, Mette; Gumpert, Heidi; Hammerum, Anette M; Westh, Henrik; Ingmer, Hanne

2017-12-01

In Danish hospitals, the number of infections caused by vancomycin-resistant Enterococcus faecium (VRE faecium) has dramatically increased in recent years. Hospital disinfectants are essential in eliminating pathogenic microorganisms, and reduced susceptibility may contribute to hospital-associated infections. We have addressed whether clinical VRE faecium display decreased biocide susceptibility when compared to vancomycin-sensitive Enterococcus faecium (VSE faecium) isolates. In total 12 VSE faecium and 37 VRE faecium isolates obtained from Danish hospitals over an extended time period were tested for susceptibility towards three commonly applied biocides, namely benzalkonium chloride, chlorhexidine and hydrogen peroxide. For benzalkonium chloride, 89 % of VRE faecium strains had a minimal inhibitory concentration (MIC) of 8 mg l -1 , whereas for VSE faecium, only 25 % of the strains had an MIC of 8 mg l -1 . For chlorhexidine, the MIC of 95 % of VRE faecium strains was 4 mg l -1 or higher, while only 33 % of VSE faecium strains displayed MIC values at the same level. In contrast, both VRE and VSE faecium displayed equal susceptibility to hydrogen peroxide, but a higher minimal bactericidal concentration (MBC) was found for the former. The efflux activity was also assessed, and this was generally higher for the VRE faecium strains compared to VSE faecium. VRE faecium from Danish hospitals demonstrated decreased susceptibility towards benzalkonium chloride and chlorhexidine compared to VSE faecium, where the use of chlorhexidine is particularly heavy in the hospital environment. These findings suggest that biocide tolerance may characterize VRE faecium isolated in Danish hospitals.

Efficacy of surface disinfectant cleaners against emerging highly resistant gram-negative bacteria

PubMed Central

2014-01-01

Background Worldwide, the emergence of multidrug-resistant gram-negative bacteria is a clinical problem. Surface disinfectant cleaners (SDCs) that are effective against these bacteria are needed for use in high risk areas around patients and on multi-touch surfaces. We determined the efficacy of several SDCs against clinically relevant bacterial species with and without common types of multidrug resistance. Methods Bacteria species used were ATCC strains; clinical isolates classified as antibiotic-susceptible; and multi-resistant clinical isolates from Klebsiella oxytoca, Klebsiella pneumoniae, and Serratia marcescens (all OXA-48 and KPC-2); Acinetobacter baumannii (OXA-23); Pseudomonas aeruginosa (VIM-1); and Achromobacter xylosoxidans (ATCC strain). Experiments were carried out according to EN 13727:2012 in quadruplicate under dirty conditions. The five evaluated SDCs were based on alcohol and an amphoteric substance (AAS), an oxygen-releaser (OR), surface-active substances (SAS), or surface-active-substances plus aldehydes (SASA; two formulations). Bactericidal concentrations of SDCs were determined at two different contact times. Efficacy was defined as a log10 ≥ 5 reduction in bacterial cell count. Results SDCs based on AAS, OR, and SAS were effective against all six species irrespective of the degree of multi-resistance. The SASA formulations were effective against the bacteria irrespective of degree of multi-resistance except for one of the four P. aeruginosa isolates (VIM-1). We found no general correlation between SDC efficacy and degree of antibiotic resistance. Conclusions SDCs were generally effective against gram-negative bacteria with and without multidrug resistance. SDCs are therefore suitable for surface disinfection in the immediate proximity of patients. Single bacterial isolates, however, might have reduced susceptibility to selected biocidal agents. PMID:24885029

Infectious Disease: Connecting Innate Immunity to Biocidal Polymers

PubMed Central

Gabriel, Gregory J.; Som, Abhigyan; Madkour, Ahmad E.; Eren, Tarik; Tew, Gregory N.

2007-01-01

Infectious disease is a critically important global healthcare issue. In the U.S. alone there are 2 million new cases of hospital-acquired infections annually leading to 90,000 deaths and 5 billion dollars of added healthcare costs. Couple these numbers with the appearance of new antibiotic resistant bacterial strains and the increasing occurrences of community-type outbreaks, and clearly this is an important problem. Our review attempts to bridge the research areas of natural host defense peptides (HDPs), a component of the innate immune system, and biocidal cationic polymers. Recently discovered peptidomimetics and other synthetic mimics of HDPs, that can be short oligomers as well as polymeric macromolecules, provide a unique link between these two areas. An emerging class of these mimics are the facially amphiphilic polymers that aim to emulate the physicochemical properties of HDPs but take advantage of the synthetic ease of polymers. These mimics have been designed with antimicrobial activity and, importantly, selectivity that rivals natural HDPs. In addition to providing some perspective on HDPs, selective mimics, and biocidal polymers, focus is given to the arsenal of biophysical techniques available to study their mode of action and interactions with phospholipid membranes. The issue of lipid type is highlighted and the important role of negative curvature lipids is illustrated. Finally, materials applications (for instance, in the development of permanently antibacterial surfaces) are discussed as this is an important part of controlling the spread of infectious disease. PMID:18160969

Microwave synthesis of ZnO@mSiO₂ for detailed antifungal mode of action study: understanding the insights into oxidative stress.

PubMed

Mitra, Shouvik; Patra, Prasun; Pradhan, Saheli; Debnath, Nitai; Dey, Kushal Kumar; Sarkar, Sampad; Chattopadhyay, Dhrubajyoti; Goswami, Arunava

2015-04-15

A simple chemical method has been devised for deliberate incorporation of zinc oxide nanoparticles (ZNPs) within mesoporous nanosilica (mSiO2) matrix to yield zinc oxide nanoparticles embedded in mesoporous nanosilica (ZnO@mSiO2). ZnO@mSiO2 inhibited the growth of four strains of fungi in a dose dependant manner. A series of biochemical assays revealed generation of oxidative stress from ZnO@mSiO2 for such biocidal response. We proposed transient superoxide and its subsequent conversion to H2O2 played a pivotal role behind such biocidal response as revealed from our systematic evaluation. This resulted morphological alteration of fungi through increase in number of facets, in correlation we found up-regulation in oxidative stress related genes. Bioavailability within the fungal sample was confirmed from microscopic, spectroscopic, biophysical techniques. Protein carbonylation of fungal species was the chemical outcome of such above mentioned stress and quantified by high performance liquid chromatography (HPLC) via subsequent hydrazone derivatization. Several in vitro and in vivo evaluations revealed the biocompatibility of ZnO@mSiO2. Altogether this report claims a new biocidal agent with a detailed mode of action focusing on the origin and quantification of oxidative stress through biophysical and biochemical techniques for the first time for real time applications. Copyright © 2014 Elsevier Inc. All rights reserved.

Intercellular adhesion and biocide resistance in nontypeable Haemophilus influenzae biofilms

PubMed Central

Izano, Era A.; Shah, Suhagi M.; Kaplan, Jeffrey B.

2009-01-01

Respiratory infections caused by nontypeable Haemophilus influenzae (NTHi) are a major medical problem. Evidence suggests that the ability to form biofilms on mucosal surfaces may play a role in NTHi pathogenesis. However, the factors that contribute to NTHi biofilm cohesion remain largely unknown. In this study we investigated the biofilm growth and detachment phenotypes of eight NTHi clinical strains in vitro. We found that the majority of strains produced biofilms within 6 hours when cultured statically in tubes. Biofilm formation was inhibited when culture medium was supplemented with proteinase K or DNase I. Both enzymes also caused significant detachment of pre-formed NTHi biofilms. These findings indicate that both proteinaceous adhesins and extracellular DNA contribute to NTHi biofilm cohesion. Treatment of NTHi biofilms cultured in centrifugal filter devices with DNase I, but not with proteinase K, caused a significant decrease in fluid convection through the biofilms. These results suggest that extracellular DNA is the major volumetric component of the NTHi biofilm matrix. Mechanical or enzymatic disruption of NTHi biofilms cultured in microtiter plates significantly increased their sensitivity to killing by SDS, cetylpyridinium chloride, chlorhexidine gluconate, povidone iodine and sodium hypochlorite. These findings indicate that biocide resistance in NTHi biofilms is mediated to a large part by the cohesive and protective properties of the biofilm matrix. Understanding the mechanisms of biofilm cohesion and biocide resistance in NTHi biofilms may lead to new methods for treating NTHi-associated infections. PMID:19490830

Physical and chemical control of released microorganisms at field sites

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

Donegan, K.; Seidler, R.; Matyac, C.

1991-01-01

An important consideration in the environmental release of a genetically engineered microorganism (GEM) is the capability for reduction or elimination of GEM populations once their function is completed or if adverse environmental effects are observed. The decontamination treatments of burning and biocide application, alone and in combination with tilling, were evaluated for their ability to reduce populations of bacteria released on the phylloplane. Field plots of bush beans sprayed with the bacterium Erwinia herbicola, received the following treatments: (1) control, (2) control + till, (3) burn, (4) burn + till, (5) Kocide (cupric hydroxide), (6) Kocide + till, (7) Agri-strepmore » (streptomycin sulfate), and (8) Agri-strept + till. Leaves and soil from the plots were sampled -1, 1, 5, 8, 12, 15, 19, and 27 days after application of the decontamination treatments. Burning produced a significant and persistent reduction in the number of bacteria whereas tilling, alone or in combination with the biocide treatments, stimulated a significant and persistent reduction in the number of bacteria, whereas tilling, alone or in combination with the biocide treatments, stimulated a significant increase in bacterial populations that persisted for several weeks.« less

Biocidal Potential and Chemical Composition of Industrial Essential Oils from Hyssopus officinalis, Lavandula × intermedia var. Super, and Santolina chamaecyparissus.

PubMed

Ortiz de Elguea-Culebras, Gonzalo; Sánchez-Vioque, Raúl; Berruga, María Isabel; Herraiz-Peñalver, David; González-Coloma, Azucena; Andrés, María Fé; Santana-Méridas, Omar

2018-01-01

This work presents the biocidal (insecticidal, ixodicidal, nematicidal, and phytotoxic) effects and chemical compositions of three essential oils obtained from the industrial steam distillation (IEOs) of hyssop (Hyssopus officinalis L.), lavandin (Lavandula × intermedia or L. × hybrida var. Super), and cotton lavender (Santolina chamaecyparissus L.). Their chemical composition analyzed by gas chromatography coupled to mass spectrometry showed 1,8-cineole (53%) and β-pinene (16%) as the major components of H. officinalis, linalyl acetate (38%) and linalool (29%) of L. × intermedia; and 1,8-cineole (10%) and 8-methylene-3-oxatricyclo[5.2.0.0 2,4 ]nonane (8%) in S. chamaecyparissus. The biocidal tests showed that L. × intermedia IEO was the most active against the insect Spodoptera littoralis and toxic to the tick Hyalomma lusitanicum, IEO of H. officinalis was strongly active against S. littoralis, and finally, S. chamaecyparissus IEO was a strong antifeedant against the aphid Rhopalosiphum padi, toxic to H. lusitanicum and with moderate effects against Leptinotarsa decemlineata, S. littoralis, and Lolium perenne. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

Halloysite clay nanotubes for controlled release of protective agents.

PubMed

Lvov, Yuri M; Shchukin, Dmitry G; Möhwald, Helmuth; Price, Ronald R

2008-05-01

Halloysite aluminosilicate nanotubes with a 15 nm lumen, 50 nm external diameter, and length of 800 +/- 300 nm have been developed as an entrapment system for loading, storage, and controlled release of anticorrosion agents and biocides. Fundamental research to enable the control of release rates from hours to months is being undertaken. By variation of internal fluidic properties, the formation of nanoshells over the nanotubes and by creation of smart caps at the tube ends it is possible to develop further means of controlling the rate of release. Anticorrosive halloysite coatings are in development and a self-healing approach has been developed for repair mechanisms through response activation to external impacts. In this Perspective, applications of halloysite as nanometer-scale containers are discussed, including the use of halloysite tubes as drug releasing agents, as biomimetic reaction vessels, and as additives in biocide and protective coatings. Halloysite nanotubes are available in thousands of tons, and remain sophisticated and novel natural nanomaterials which can be used for the loading of agents for metal and plastic anticorrosion and biocide protection.

Test methods for estimating the efficacy of the fast-acting disinfectant peracetic acid on surfaces of personal protective equipment.

PubMed

Lemmer, K; Howaldt, S; Heinrich, R; Roder, A; Pauli, G; Dorner, B G; Pauly, D; Mielke, M; Schwebke, I; Grunow, R

2017-11-01

The work aimed at developing and evaluating practically relevant methods for testing of disinfectants on contaminated personal protective equipment (PPE). Carriers were prepared from PPE fabrics and contaminated with Bacillus subtilis spores. Peracetic acid (PAA) was applied as a suitable disinfectant. In method 1, the contaminated carrier was submerged in PAA solution; in method 2, the contaminated area was covered with PAA; and in method 3, PAA, preferentially combined with a surfactant, was dispersed as a thin layer. In each method, 0·5-1% PAA reduced the viability of spores by a factor of ≥6 log 10 within 3 min. The technique of the most realistic method 3 proved to be effective at low temperatures and also with a high organic load. Vaccinia virus and Adenovirus were inactivated with 0·05-0·1% PAA by up to ≥6 log 10 within 1 min. The cytotoxicity of ricin was considerably reduced by 2% PAA within 15 min of exposure. PAA/detergent mixture enabled to cover hydrophobic PPE surfaces with a thin and yet effective disinfectant layer. The test methods are objective tools for estimating the biocidal efficacy of disinfectants on hydrophobic flexible surfaces. © 2017 The Society for Applied Microbiology.

Efficacy of chemical disinfectants for the containment of the salamander chytrid fungus Batrachochytrium salamandrivorans.

PubMed

Van Rooij, Pascale; Pasmans, Frank; Coen, Yanaika; Martel, An

2017-01-01

The recently emerged chytrid fungus Batrachochytrium salamandrivorans (Bsal) causes European salamander declines. Proper hygiene protocols including disinfection procedures are crucial to prevent disease transmission. Here, the efficacy of chemical disinfectants in killing Bsal was evaluated. At all tested conditions, Biocidal®, Chloramine-T®, Dettol medical®, Disolol®, ethanol, F10®, Hibiscrub®, potassium permanganate, Safe4®, sodium hypochlorite, and Virkon S®, were effective at killing Bsal. Concentrations of 5% sodium chloride or lower, 0.01% peracetic acid and 0.001-1% copper sulphate were inactive against Bsal. None of the conditions tested for hydrogen peroxide affected Bsal viability, while it did kill Batrachochytrium dendrobatidis (Bd). For Bsal, enzymatic breakdown of hydrogen peroxide by catalases and specific morphological features (clustering of sporangia, development of new sporangia within the original sporangium), were identified as fungal factors altering susceptibility to several of the disinfectants tested. Based on the in vitro results we recommend 1% Virkon S®, 4% sodium hypochlorite and 70% ethanol for disinfecting equipment in the field, lab or captive setting, with a minimal contact time of 5 minutes for 1% Virkon S® and 1 minute for the latter disinfectants. These conditions not only efficiently target Bsal, but also Bd and Ranavirus.

Environmental risk assessment of biocidal products: identification of relevant components and reliability of a component-based mixture assessment.

PubMed

Coors, Anja; Vollmar, Pia; Heim, Jennifer; Sacher, Frank; Kehrer, Anja

2018-01-01

Biocidal products are mixtures of one or more active substances (a.s.) and a broad range of formulation additives. There is regulatory guidance currently under development that will specify how the combined effects of the a.s. and any relevant formulation additives shall be considered in the environmental risk assessment of biocidal products. The default option is a component-based approach (CBA) by which the toxicity of the product is predicted from the toxicity of 'relevant' components using concentration addition. Hence, unequivocal and practicable criteria are required for identifying the 'relevant' components to ensure protectiveness of the CBA, while avoiding unnecessary workload resulting from including by default components that do not significantly contribute to the product toxicity. The present study evaluated a set of different criteria for identifying 'relevant' components using confidential information on the composition of 21 wood preservative products. Theoretical approaches were complemented by experimentally testing the aquatic toxicity of seven selected products. For three of the seven tested products, the toxicity was underestimated for the most sensitive endpoint (green algae) by more than factor 2 if only the a.s. were considered in the CBA. This illustrated the necessity of including at least some additives along with the a.s. Considering additives that were deemed 'relevant' by the tentatively established criteria reduced the underestimation of toxicity for two of the three products. A lack of data for one specific additive was identified as the most likely reason for the remaining toxicity underestimation of the third product. In three other products, toxicity was overestimated by more than factor 2, while prediction and observation fitted well for the seventh product. Considering all additives in the prediction increased only the degree of overestimation. Supported by theoretical calculations and experimental verifications, the present study developed criteria for the identification of CBA-relevant components in a biocidal product. These criteria are based on existing criteria stated in the regulation for classification, labelling and packaging of substances. The CBA was found sufficiently protective and reliable for the tested products when applying the here recommended criteria. The lack of available aquatic toxicity data for some of the identified relevant components was the main reason for underestimation of product toxicity.

Superb hydroxyl radical-mediated biocidal effect induced antibacterial activity of tuned ZnO/chitosan type II heterostructure under dark

NASA Astrophysics Data System (ADS)

Podder, Soumik; Halder, Suman; Roychowdhury, Anirban; Das, Dipankar; Ghosh, Chandan Kr.

2016-10-01

Reactive oxygen species (ROS) is the most dominating factor for bacteria cell toxicity due to release of oxidative stress. Hydroxyl radical (·OH) is a strong oxidizing ROS that has high impact on biocidal activity. This present paper highlights ·OH influenced antibacterial activity and biocidal propensity of tuned ZnO/chitosan (ZnO/CS) nanocomposite against Pseudomonas putida (P. putida) in the absence of light for the first time. For this purpose, the CS proportion was increased by 25 % (w/w) of ZnO during the preparation of ZnO/CS nanocomposite and a systematic study of different ROS like superoxide anion (O 2 ·- ), hydrogen peroxide (H2O2) and ·OH production as well as their kinetics was carried out both under UV irradiation and in dark by UV-Vis spectroscopy using NBT dye, starch and iodine reaction and fluorescence spectroscopy using terephthalic acid. The decoration of ZnO nanoparticles (ZnO·NPs) with CS tuning was characterized by XRD and FTIR spectroscopy, revealing sustained crystallinity and surface coating of ZnO NP (size about 24 nm) by CS molecule. The hybridization of ZnO nanoparticles with CS@50 wt% (w/w) resulted superior biocidal activity (81 %) within 3 h in dark mediated by optimum production of ·OH among all ROS. Here we have proposed the enhanced production of ·OH in ZnO/CS due to generation of holes by entrapment of electrons in acceptor level formed in nanocomposite for the first time, and the acceptor levels were probed by Positron annihilation lifetime spectroscopy. The increase in non-positronium (non-Ps) formation probability (I2) in ZnO/CS nanocomposite confirmed the acceptor levels. This work also confirms surface defect-mediated ROS generation in dark, and zinc interstitials are proposed as active defect sites for generation of holes and ·OH for the first time and confirmed by steady-state room temperature photoluminescence spectroscopy. Finally, a plausible mechanism was hypothesized focusing on hole generation in ZnO NP and hole transfer from CS for the first time, and a heterostructure of type II was proposed.

Developmental neurotoxicity of different pesticides in PC-12 cells in vitro

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

Christen, Verena

The detection of developmental neurotoxicity (DNT) of chemicals has high relevance for protection of human health. However, DNT of many pesticides is only little known. Furthermore, validated in vitro systems for assessment of DNT are not well established. Here we employed the rat phaeochromocytoma cell line PC-12 to evaluate DNT of 18 frequently used pesticides of different classes, including neonicotinoids, pyrethroids, organophosphates, organochlorines, as well as quaternary ammonium compounds, the organic compound used in pesticides, piperonyl butoxide, as well as the insect repellent diethyltoluamide (DEET). We determined the outgrowth of neurites in PC-12 cells co-treated with nerve growth factor andmore » different concentrations of biocides for 5 days. Furthermore, we determined transcriptional alterations of selected genes that may be associated with DNT, such as camk2α and camk2β, gap-43, neurofilament-h, tubulin-α and tubulin-β. Strong and dose- dependent inhibition of neurite outgrowth was induced by azamethiphos and chlorpyrifos, and dieldrin and heptachlor, which was correlated with up-regulation of gap-43. No or only weak effects on neurite outgrowth and transcriptional alterations occurred for neonicotinoids acetamiprid, clothianidin, imidacloprid and thiamethoxam, the pyrethroids λ-cyhalothrin, cyfluthrin, deltamethrin, and permethrin, the biocidal disinfectants C12-C14-alkyl(ethylbenzyl)dimethylammonium (BAC), benzalkonium chloride and barquat (dimethyl benzyl ammonium chloride), and piperonyl butoxide and DEET. Our study confirms potential developmental neurotoxicity of some pesticides and provides first evidence that azamethiphos has the potential to act as a developmental neurotoxic compound. We also demonstrate that inhibition of neurite outgrowth and transcriptional alterations of gap-43 expression correlate, which suggests the employment of gap-43 expression as a biomarker for detection and initial evaluation of potential DNT of chemicals. - Highlights: • The developmental neurotoxicity (DNT) of biocides is poorly known. • We assessed different classes of biocides for DNT in PC-12 cells. • DNT was shown by neurite outgrowth (NOG) and transcriptional changes. • Azamethiphos, chlorpyrifos, dieldrin and heptachlor showed DNT. • NOG correlated with induction of gap-43 which is an important determinant for DNT.« less

New biocide guanidine-containing nanocomposites

NASA Astrophysics Data System (ADS)

Gorbunova, Marina; Lemkina, Larisa

2014-08-01

New water-soluble nanocomposites based on Ag and copolymers of 2,2-diallyl-1,1,3,3-tetraethylguanidiniumchloride with N-vinylpyrrolidone [poly(AGC-VP)] and vinylacetate [poly(AGC-VA)] have been developed. The average silver particle size ranged from 52 to 62 nm for poly(AGC-VA) and from 28 to 30 nm for poly(AGC-VP), with the corresponding UV-vis absorption peak position at 405-410 nm. The using of copolymers resulted in improvement in bactericide properties of composites. Following these results, the newly developed nanocomposite scaffold may be considered for new water-soluble medicines and biocides.

Development of a preprototype hyperfiltration wash water recovery subsystem

NASA Technical Reports Server (NTRS)

1981-01-01

The use of hyperfiltration as a mode of reclamation of waste water on board an extended mission spacecraft was investigated. Two basic approaches are considered with respect to hyperfiltration of wash water recovery. The initial approach involves the use of a hollow fiber permeator and a tubular module, operating at ambient temperature. In this system, relatively large doses of biocides are used to control microbial activity. Since biocides require a long contact time, and many have adverse dematological effects as well as many interact with membrane material, a second approach is considered which involves operating at pasturization temperature.

Biocidal quaternary ammonium resin

NASA Technical Reports Server (NTRS)

Janauer, G. E.

1983-01-01

Activated carbon (charcoal) and polymeric resin sorbents are widely used in the filtration and treatment of drinking water, mainly to remove dissolved organic and inorganic impurities and to improve the taste. Earlier hopes that activated carbon might "disinfect' water proved to be unfounded. The feasibility of protecting against microbial infestation in charcoal and resin beds such as those to be incorporated into total water reuse systems in spacecraft was investigated. The biocidal effect of IPCD (insoluable polymeric contact disinfectants) in combination with a representative charcoal was assessed. The ion exchange resins (IPCD) were shown to adequately protect charcoal and ion exchange beds.

NDELA and nickel modulation of triazine disposition in skin.

PubMed

Baynes, Ronald E; Brooks, James D; Barlow, Beth M; Riviere, Jim E

2005-10-01

Cutting fluids can become contaminated with metals (e.g., nickel, Ni) and nitrosamines (e.g., N-nitrosodiethanolamine, NDELA) and there is concern that these classes of contaminants can modulate dermal disposition and ultimately the toxicity of cutting fluid additives, such as irritant biocides (e.g., triazine). Biocides are added to these formulations to prevent bacterial degradation of commercial cutting fluids. The purpose of this study was to assess the dermal absorption and skin deposition of 14C-triazine when topically applied to porcine skin in an in vitro flow-through diffusion cell system as aqueous soluble oil (mineral oil, MO) or aqueous synthetic (polyethylene glycol, PEG) mixtures. 14C-Triazine mixtures were formulated with NDELA and/or Ni, or with a combination of three additional cutting fluid additives; namely, 5% linear alkylbenzene sulfonate (LAS), 5% triethanolamine (TEA) and 5% sulfurized ricinoleic acid. Neither Ni nor NDELA was absorbed during these 8-h studies. However, 14C-triazine absorption ranged from 2.72 to 3.29% dose in MO and 2.29-2.88% dose in PEG with significantly greater triazine absorption in MO than PEG when all additives and contaminates were present. The difference between these two diluents was most pronounced when NDELA and/or Ni were present in cutting fluids. These contaminants also enhanced triazine deposition on the skin surface and skin tissues especially with PEG-based mixtures. In essence, the dermal disposition of irritant biocides could be dependent on whether the worker is exposed to a soluble oil or synthetic fluid when these contaminants are present. Workers should therefore not only be concerned about dermatotoxicity of these contaminants, but also the modulated dermal disposition of cutting fluid additives when these contaminants are present in cutting fluid formulations.

Human Health Risk of Ingested Nanoparticles That Are Added as Multifunctional Agents to Paints: an In Vitro Study

PubMed Central

Kaiser, Jean-Pierre; Roesslein, Matthias; Diener, Liliane; Wick, Peter

2013-01-01

Microorganisms growing on painted surfaces are not only an aesthetic problem, but also actively contribute to the weathering and deterioration of materials. A widely used strategy to combat microbial colonization is the addition of biocides to the paint. However, ecotoxic, non-degradable biocides with a broad protection range are now prohibited in Europe, so the paint industry is considering engineered nanoparticles (ENPs) as an alternative biocide. There is concern that ENPs in paint might be released in run-off water and subsequently consumed by animals and/or humans, potentially coming into contact with cells of the gastrointestinal tract and affecting the immune system. Therefore, in the present study we evaluated the cytotoxic effects of three ENPs (nanosilver, nanotitanium dioxide and nanosilicon dioxide) that have a realistic potential for use in paints in the near future. When exposed to nanotitanium dioxide and nanosilicon dioxide in concentrations up to 243 µg/mL for 48 h, neither the gastrointestinal cells (CaCo-2) nor immune system cells (Jurkat) were significantly affected. However, when exposed to nanosilver, several cell parameters were affected, but far less than by silver ions used as a control. No differences in cytotoxicity were observed when cells were exposed to ENP-containing paint particles, compared with the same paint particles without ENPs. Paint particles containing ENPs did not affect cell morphology, the release of reactive oxygen species or cytokines, cell activity or cell death in a different manner to the same paint particles without ENPs. The results suggest that paints doped with ENPs do not pose an additional acute health hazard for humans. PMID:24358264

Bioluminescence inhibition assays for toxicity screening of wood extractives and biocides in paper mill process waters.

PubMed

Rigol, Anna; Latorre, Anna; Lacorte, Sílvia; Barceló, Damià

2004-02-01

The risk associated with wood extractives, biocides, and other additives in pulp and paper mill effluents was evaluated by performing a characterization of process waters and effluents in terms of toxicity and chemical analysis. The individual toxicity of 10 resin acids, two unsaturated fatty acids, and three biocides was estimated by measuring the bioluminescence inhibition with a ToxAlert 100 system. Median effective concentration values (EC50) of 4.3 to 17.9, 1.2 to 1.5, and 0.022 to 0.50 mg/L were obtained, respectively. Mixtures of these three families of compounds showed antagonistic effects. Chemical analysis of process waters was performed by liquid chromatography- and gas chromatography-mass spectrometry. Biocides such as 2-(thiocyanomethylthio)-benzotiazole (TCMTB) (EC50 = 0.022 mg/L) and 2,2-dibromo-3-nitrilpropionamide (DBNPA) (EC50 = 0.50 mg/L) were the most toxic compounds tested and were detected at concentrations of 16 and 59 microg/L, respectively, in a closed-circuit recycling paper mill. Process waters from kraft pulp mills, printing paper mills, and packing board paper mills showed the highest concentration of resin acids (up to 400 microg/L) and accounted for inhibition percentages up to 100%. Detergent degradation products such as nonylphenol (NP) and octylphenol (OP) and the plasticizer bisphenol A (BPA) were also detected in the waters at levels of 0.6 to 10.6, 0.3 to 1.4, and 0.7 to 187 microg/L, respectively. However, once these waters were biologically treated, the concentration of detected organic compounds diminished and the toxicity decreased in most cases to values of inhibition lower than 20%.

Evaluation of Reduced Susceptibility to Quaternary Ammonium Compounds and Bisbiguanides in Clinical Isolates and Laboratory-Generated Mutants of Staphylococcus aureus

PubMed Central

Furi, Leonardo; Ciusa, Maria Laura; Knight, Daniel; Di Lorenzo, Valeria; Tocci, Nadia; Cirasola, Daniela; Aragones, Lluis; Coelho, Joana Rosado; Freitas, Ana Teresa; Marchi, Emmanuela; Moce, Laura; Visa, Pilar; Northwood, John Blackman; Viti, Carlo; Borghi, Elisa; Orefici, Graziella

2013-01-01

The MICs and minimum bactericidal concentrations (MBCs) for the biocides benzalkonium chloride and chlorhexidine were determined against 1,602 clinical isolates of Staphylococcus aureus. Both compounds showed unimodal MIC and MBC distributions (2 and 4 or 8 mg/liter, respectively) with no apparent subpopulation with reduced susceptibility. To investigate further, all isolates were screened for qac genes, and 39 of these also had the promoter region of the NorA multidrug-resistant (MDR) efflux pump sequenced. The presence of qacA, qacB, qacC, and qacG genes increased the mode MIC, but not MBC, to benzalkonium chloride, while only qacA and qacB increased the chlorhexidine mode MIC. Isolates with a wild-type norA promoter or mutations in the norA promoter had similar biocide MIC distributions; notably, not all clinical isolates with norA mutations were resistant to fluoroquinolones. In vitro efflux mutants could be readily selected with ethidium bromide and acriflavine. Multiple passages were necessary to select mutants with biocides, but these mutants showed phenotypes comparable to those of mutants selected by dyes. All mutants showed changes in the promoter region of norA, but these were distinct from this region of the clinical isolates. Still, none of the in vitro mutants displayed fitness defects in a killing assay in Galleria mellonella larvae. In conclusion, our data provide an in-depth comparative overview on efflux in S. aureus mutants and clinical isolates, showing also that plasmid-encoded efflux pumps did not affect bactericidal activity of biocides. In addition, current in vitro tests appear not to be suitable for predicting levels of resistance that are clinically relevant. PMID:23669380

Marketing netcoatings for aquaculture.

PubMed

Martin, Robert J

2014-10-17

Unsustainable harvesting of natural fish stocks is driving an ever growing marine aquaculture industry. Part of the aquaculture support industry is net suppliers who provide producers with nets used in confining fish while they are grown to market size. Biofouling must be addressed in marine environments to ensure maximum product growth by maintaining water flow and waste removal through the nets. Biofouling is managed with copper and organic biocide based net coatings. The aquaculture industry provides a case study for business issues related to entry of improved fouling management technology into the marketplace. Several major hurdles hinder entry of improved novel technologies into the market. The first hurdle is due to the structure of business relationships. Net suppliers can actually cut their business profits dramatically by introducing improved technologies. A second major hurdle is financial costs of registration and demonstration of efficacy and quality product with a new technology. Costs of registration are prohibitive if only the net coatings market is involved. Demonstration of quality product requires collaboration and a team approach between formulators, net suppliers and farmers. An alternative solution is a vertically integrated business model in which the support business and product production business are part of the same company.

Marketing Netcoatings for Aquaculture

PubMed Central

Martin, Robert J.

2014-01-01

Unsustainable harvesting of natural fish stocks is driving an ever growing marine aquaculture industry. Part of the aquaculture support industry is net suppliers who provide producers with nets used in confining fish while they are grown to market size. Biofouling must be addressed in marine environments to ensure maximum product growth by maintaining water flow and waste removal through the nets. Biofouling is managed with copper and organic biocide based net coatings. The aquaculture industry provides a case study for business issues related to entry of improved fouling management technology into the marketplace. Several major hurdles hinder entry of improved novel technologies into the market. The first hurdle is due to the structure of business relationships. Net suppliers can actually cut their business profits dramatically by introducing improved technologies. A second major hurdle is financial costs of registration and demonstration of efficacy and quality product with a new technology. Costs of registration are prohibitive if only the net coatings market is involved. Demonstration of quality product requires collaboration and a team approach between formulators, net suppliers and farmers. An alternative solution is a vertically integrated business model in which the support business and product production business are part of the same company. PMID:25329615

Enhanced chlorhexidine skin penetration with eucalyptus oil

PubMed Central

2010-01-01

Background Chlorhexidine digluconate (CHG) is a widely used skin antiseptic, however it poorly penetrates the skin, limiting its efficacy against microorganisms residing beneath the surface layers of skin. The aim of the current study was to improve the delivery of chlorhexidine digluconate (CHG) when used as a skin antiseptic. Method Chlorhexidine was applied to the surface of donor skin and its penetration and retention under different conditions was evaluated. Skin penetration studies were performed on full-thickness donor human skin using a Franz diffusion cell system. Skin was exposed to 2% (w/v) CHG in various concentrations of eucalyptus oil (EO) and 70% (v/v) isopropyl alcohol (IPA). The concentration of CHG (μg/mg of skin) was determined to a skin depth of 1500 μm by high performance liquid chromatography (HPLC). Results The 2% (w/v) CHG penetration into the lower layers of skin was significantly enhanced in the presence of EO. Ten percent (v/v) EO in combination with 2% (w/v) CHG in 70% (v/v) IPA significantly increased the amount of CHG which penetrated into the skin within 2 min. Conclusion The delivery of CHG into the epidermis and dermis can be enhanced by combination with EO, which in turn may improve biocide contact with additional microorganisms present in the skin, thereby enhancing antisepsis. PMID:20860796

Essential Oils of Plants as Biocides against Microorganisms Isolated from Cuban and Argentine Documentary Heritage.

PubMed

Borrego, Sofía; Valdés, Oderlaise; Vivar, Isbel; Lavin, Paola; Guiamet, Patricia; Battistoni, Patricia; Gómez de Saravia, Sandra; Borges, Pedro

2012-01-01

Natural products obtained from plants with biocidal activity represent an alternative and useful source in the control of biodeterioration of documentary heritage, without negative environmental and human impacts. In this work, we studied the antimicrobial activity of seven essential oils against microorganisms associated with the biodeterioration of documentary heritage. The essential oils were obtained by steam distillation. The antimicrobial activity was analyzed using the agar diffusion method against 4 strains of fungi and 6 bacterial strains isolated from repositories air and documents of the National Archive of the Republic of Cuba and the Historical Archive of the Museum of La Plata, Argentina. Anise and garlic oils showed the best antifungal activity at all concentrations studied, while oregano oil not only was effective against fungi tested but also prevented sporulation of them all. Orange sweet and laurel oils were ineffective against fungi. Clove, garlic, and oregano oils showed the highest antibacterial activity at 25% against Enterobacter agglomerans and Streptomyces sp., while only clove and oregano oils were effective against Bacillus sp. at all concentrations studied. This study has an important implication for the possible use of the natural products from plants in the control of biodeterioration of documentary heritage.

Essential Oils of Plants as Biocides against Microorganisms Isolated from Cuban and Argentine Documentary Heritage

PubMed Central

Borrego, Sofía; Valdés, Oderlaise; Vivar, Isbel; Lavin, Paola; Guiamet, Patricia; Battistoni, Patricia; Gómez de Saravia, Sandra; Borges, Pedro

2012-01-01

Natural products obtained from plants with biocidal activity represent an alternative and useful source in the control of biodeterioration of documentary heritage, without negative environmental and human impacts. In this work, we studied the antimicrobial activity of seven essential oils against microorganisms associated with the biodeterioration of documentary heritage. The essential oils were obtained by steam distillation. The antimicrobial activity was analyzed using the agar diffusion method against 4 strains of fungi and 6 bacterial strains isolated from repositories air and documents of the National Archive of the Republic of Cuba and the Historical Archive of the Museum of La Plata, Argentina. Anise and garlic oils showed the best antifungal activity at all concentrations studied, while oregano oil not only was effective against fungi tested but also prevented sporulation of them all. Orange sweet and laurel oils were ineffective against fungi. Clove, garlic, and oregano oils showed the highest antibacterial activity at 25% against Enterobacter agglomerans and Streptomyces sp., while only clove and oregano oils were effective against Bacillus sp. at all concentrations studied. This study has an important implication for the possible use of the natural products from plants in the control of biodeterioration of documentary heritage. PMID:23762760

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

PubMed Central

Christensen, Ellen G.; Gram, Lone; Kastbjerg, Vicky G.

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 agents. The purpose of the present study was to determine if sublethal biocide concentrations affected antibiotic susceptibility in L. monocytogenes. Exposure of L. monocytogenes strains EGD and N53-1 to sublethal concentrations of Incimaxx DES (containing peroxy acids and hydrogen peroxide) and Triquart Super (containing quaternary ammonium compound) in four consecutive cultures did not alter the frequency of antibiotic-tolerant isolates, as determined by plating on 2× the MIC for a range of antibiotics. Exposure of eight strains of L. monocytogenes to 1 and 4 μg/ml triclosan did not alter triclosan sensitivity. However, all eight strains became resistant to gentamicin (up to 16-fold increase in MIC) after exposure to sublethal triclosan concentrations. Gentamicin-resistant isolates of strains N53-1 and 4446 were also resistant to other aminoglycosides, such as kanamycin, streptomycin, and tobramycin. Gentamicin resistance remained at a high level also after five subcultures without triclosan or gentamicin. Aminoglycoside resistance can be caused by mutations in the target site, the 16S rRNA gene. However, such mutations were not detected in the N53-1-resistant isolates. A combination of gentamicin and ampicillin 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. PMID:21746948

Light and dark-activated biocidal activity of conjugated polyelectrolytes.

PubMed

Ji, Eunkyung; Corbitt, Thomas S; Parthasarathy, Anand; Schanze, Kirk S; Whitten, David G

2011-08-01

This Spotlight on Applications provides an overview of a research program that has focused on the development and mechanistic study of cationic conjugated polyelectrolytes (CPEs) that function as light- and dark-active biocidal agents. Investigation has centered on poly-(phenylene ethynylene) (PPE) type conjugated polymers that are functionalized with cationic quaternary ammonium solubilizing groups. These polymers are found to interact strongly with Gram-positive and Gram-negative bacteria, and upon illumination with near-UV and visible light act to rapidly kill the bacteria. Mechanistic studies suggest that the cationic PPE-type polymers efficiently sensitize singlet oxygen ((1)O(2)), and this cytotoxic agent is responsible for initiating the sequence of events that lead to light-activated bacterial killing. Specific CPEs also exhibit dark-active antimicrobial activity, and this is believed to arise due to interactions between the cationic/lipophilic polymers and the negatively charged outer membrane characteristic of Gram-negative bacteria. Specific results are shown where a cationic CPE with a degree of polymerization of 49 exhibits pronounced light-activated killing of E. coli when present in the cell suspension at a concentration of 1 μg mL(-1).

Antifouling paint booster biocides (Irgarol 1051 and diuron) in marinas and ports of Bushehr, Persian Gulf.

PubMed

Saleh, Abolfazl; Molaei, Saeideh; Sheijooni Fumani, Neda; Abedi, Ehsan

2016-04-15

In the present study, antifouling paint booster biocides, Irgarol 1051 and diuron were measured in ports and marinas of Bushehr, Iran. Results showed that in seawater samples taken from ports and marinas, Irgarol was found at the range of less than LOD to 63.4ngL(-1) and diuron was found to be at the range of less than LOD to 29.1ngL(-1) (in Jalali marina). 3,4-dichloroaniline (3,4-DCA), as a degradation product of diuron, was also analyzed and its maximum concentration was 390ngL(-1). Results for analysis of Irgarol 1051 in sediments showed a maximum concentration of 35.4ngg(-1) dry weight in Bandargah marina. A comparison between the results of this study and those of other published works showed that Irgarol and diuron pollutions in ports and marinas of Bushehr located in the Persian Gulf were less than the average of reports from other parts of the world. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tire tread wear particles in ambient air--a previously unknown source of human exposure to the biocide 2-mercaptobenzothiazole.

PubMed

Avagyan, Rozanna; Sadiktsis, Ioannis; Bergvall, Christoffer; Westerholm, Roger

2014-10-01

Urban particulate matter (PM), asphalt, and tire samples were investigated for their content of benzothiazole and benzothiazole derivates. The purpose of this study was to examine whether wear particles, i.e., tire tread wear or road surface wear, could contribute to atmospheric concentrations of benzothiazole derivatives. Airborne particulate matter (PM10) sampled at a busy street in Stockholm, Sweden, contained on average 17 pg/m(3) benzothiazole and 64 pg/m(3) 2-mercaptobenzothiazole, and the total suspended particulate-associated benzothiazole and 2-mercaptobenzothiazole concentrations were 199 and 591 pg/m(3), respectively. This indicates that tire tread wear may be a major source of these benzothiazoles to urban air PM in Stockholm. Furthermore, 2-mercaptobenzothiazole was determined in urban air particulates for the first time in this study, and its presence in inhalable PM10 implies that the human exposure to this biocide is underestimated. This calls for a revision of the risk assessments of 2-mercaptobenzothiazole exposure to humans which currently is limited to occupational exposure.

Novel silver-based nanoclay as an antimicrobial in polylactic acid food packaging coatings.

PubMed

Busolo, Maria A; Fernandez, Patricia; Ocio, Maria J; Lagaron, Jose M

2010-11-01

This paper presents a comprehensive performance study of polylactic acid (PLA) biocomposites, obtained by solvent casting, containing a novel silver-based antimicrobial layered silicate additive for use in active food packaging applications. The silver-based nanoclay showed strong antimicrobial activity against Gram-negative Salmonella spp. Despite the fact that no exfoliation of the silver-based nanoclay in PLA was observed, as suggested by transmission electron microscopy (TEM) and wide angle X-ray scattering (WAXS) experiments, the additive dispersed nicely throughout the PLA matrix to a nanoscale, yielding nanobiocomposites. The films were highly transparent with enhanced water barrier and strong biocidal properties. Silver migration from the films to a slightly acidified water medium, considered an aggressive food simulant, was measured by stripping voltammetry. Silver migration accelerated after 6 days of exposure. Nevertheless, the study suggests that migration levels of silver, within the specific migration levels referenced by the European Food Safety Agency (EFSA), exhibit antimicrobial activity, supporting the potential application of this biocidal additive in active food-packaging applications to improve food quality and safety.

ITCS Test Strip Development and Certification

NASA Technical Reports Server (NTRS)

Carrigan, Caitlin; Adam, Niklas; Pickering, Karen; Gazda, Daniel; Piowaty, Hailey

2011-01-01

Internal coolant loops used for International Space Station thermal control must be periodically monitored for system health, including pH, biocide levels and any indication of ammonia. The presence of ammonia, possible via a microleak in the interface between the internal and external thermal control systems, could be a danger to the crew. The Internal Thermal Control System (ITCS) Sampling Kit uses test strips as a colorimetric indicator of pH and concentrations of biocide and free ammonia. This paper describes the challenges in designing an ammonia colorimetric indicator in a variable pH environment, as well as lessons learned, ultimately resulting in a robust test strip to indicate a hazardous ammonia leak.

Antibacterial activity of silver-killed bacteria: the "zombies" effect

NASA Astrophysics Data System (ADS)

Wakshlak, Racheli Ben-Knaz; Pedahzur, Rami; Avnir, David

2015-04-01

We report a previously unrecognized mechanism for the prolonged action of biocidal agents, which we denote as the zombies effect: biocidally-killed bacteria are capable of killing living bacteria. The concept is demonstrated by first killing Pseudomonas aeruginosa PAO1 with silver nitrate and then challenging, with the dead bacteria, a viable culture of the same bacterium: Efficient antibacterial activity of the killed bacteria is observed. A mechanism is suggested in terms of the action of the dead bacteria as a reservoir of silver, which, due to Le-Chatelier's principle, is re-targeted to the living bacteria. Langmuirian behavior, as well as deviations from it, support the proposed mechanism.

[Cytotoxicity of chemicals used in household products: 1997- 2004].

PubMed

Ikarashi, Yoshiaki; Kaniwa, Masa-aki; Tsuchiya, Toshie

2005-01-01

The cytotoxicities of chemicals used in household products were evaluated using a neutral red (NR) uptake assay. The chemicals tested during 1997-2004 were rubber additives (accelerators, antioxidants and retarders), solvents, plasticizers and biocides, such as antimicrobials, fungicides, preservatives used in paints, paper, wood and plastic products. The cytotoxicity potential of each chemical was classified by determining the concentrations inducing 50% reduction of NR uptake into Chinese hamster fibroblast V79 cells compared to control (IC50). In vivo eye irritancy of each chemical was estimated by the IC50 value. Most biocides tested showed strong cytotoxicity and had a high probability of inducing strong eye irritation.

Current Knowledge on Listeria monocytogenes Biofilms in Food-Related Environments: Incidence, Resistance to Biocides, Ecology and Biocontrol.

PubMed

Rodríguez-López, Pedro; Rodríguez-Herrera, Juan José; Vázquez-Sánchez, Daniel; López Cabo, Marta

2018-06-05

Although many efforts have been made to control Listeria monocytogenes in the food industry, growing pervasiveness amongst the population over the last decades has made this bacterium considered to be one of the most hazardous foodborne pathogens. Its outstanding biocide tolerance capacity and ability to promiscuously associate with other bacterial species forming multispecies communities have permitted this microorganism to survive and persist within the industrial environment. This review is designed to give the reader an overall picture of the current state-of-the-art in L. monocytogenes sessile communities in terms of food safety and legislation, ecological aspects and biocontrol strategies.

Antibacterial polymer coatings.

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

Wilson, Mollye C.; Allen, Ashley N.; Barnhart, Meghan

2009-09-01

A series of poly(sulfone)s with quaternary ammonium groups and another series with aldehyde groups are synthesized and tested for biocidal activity against vegetative bacteria and spores, respectively. The polymers are sprayed onto substrates as coatings which are then exposed to aqueous suspensions of organisms. The coatings are inherently biocidal and do not release any agents into the environment. The coatings adhere well to both glass and CARC-coated coupons and they exhibit significant biotoxicity. The most effective quaternary ammonium polymers kills 99.9% of both gram negative and gram positive bacteria and the best aldehyde coating kills 81% of the spores onmore » its surface.« less

Human Health Concenrs of the Metalworking Fluid Components

NASA Astrophysics Data System (ADS)

Gerulová, Kristína; Buranská, Eva; Soldán, Maroš

2017-06-01

The exploration of 209 available Material safety data sheets of 85 straight oils, 46 emulsions, 51 semi-synthetics and 27 synthetics was carried out to provide a report on the most used components defined as dangerous substances. As many as 217 of different substances of which 15 were identified as biocides, 17 as corrosion inhibitors or neutralizing agent, 17 were lubricity improvers and 38 different base fluids, lubricity solvents or surfactants, while 93 substances were not identified specifically and 37 substances occurred only once. This article is focused on the list of biocides, neutralizing agents and corrosion inhibitors identified in all types of MWFs and their possible health effects.

In-Flight Water Quality Monitoring on the International Space Station (ISS): Measuring Biocide Concentrations with Colorimetric Solid Phase Extraction (CSPE)

NASA Technical Reports Server (NTRS)

Gazda, Daniel B.; Schultz, John R.; Siperko, Lorraine M.; Porter, Marc D.; Lipert, Robert J.; Flint, Stephanie M.; McCoy, J. Torin

2011-01-01

The colorimetric water quality monitoring kit (CWQMK) was delivered to the International Space Station (ISS) on STS-128/17A and was initially deployed in September 2009. The kit was flown as a station development test objective (SDTO) experiment to evaluate the acceptability of colorimetric solid phase extraction (CSPE) technology for routine water quality monitoring on the ISS. During the SDTO experiment, water samples from the U.S. water processor assembly (WPA), the U.S. potable water dispenser (PWD), and the Russian system for dispensing ground-supplied water (SVO-ZV) were collected and analyzed with the CWQMK. Samples from the U.S. segment of the ISS were analyzed for molecular iodine, which is the biocide added to water in the WPA. Samples from the SVOZV system were analyzed for ionic silver, the biocide used on the Russian segment of the ISS. In all, thirteen in-flight analysis sessions were completed as part of the SDTO experiment. This paper provides an overview of the experiment and reports the results obtained with the CWQMK. The forward plan for certifying the CWQMK as operational hardware and expanding the capabilities of the kit are also discussed.

High performance polypyrrole coating for corrosion protection and biocidal applications

NASA Astrophysics Data System (ADS)

Nautiyal, Amit; Qiao, Mingyu; Cook, Jonathan Edwin; Zhang, Xinyu; Huang, Tung-Shi

2018-01-01

Polypyrrole (PPy) coating was electrochemically synthesized on carbon steel using sulfonic acids as dopants: p-toluene sulfonic acid (p-TSA), sulfuric acid (SA), (±) camphor sulfonic acid (CSA), sodium dodecyl sulfate (SDS), and sodium dodecylbenzene sulfonate (SDBS). The effect of acidic dopants (p-TSA, SA, CSA) on passivation of carbon steel was investigated by linear potentiodynamic and compared with morphology and corrosion protection performance of the coating produced. The types of the dopants used were significantly affecting the protection efficiency of the coating against chloride ion attack on the metal surface. The corrosion performance depends on size and alignment of dopant in the polymer backbone. Both p-TSA and SDBS have extra benzene ring that stack together to form a lamellar sheet like barrier to chloride ions thus making them appropriate dopants for PPy coating in suppressing the corrosion at significant level. Further, adhesion performance was enhanced by adding long chain carboxylic acid (decanoic acid) directly in the monomer solution. In addition, PPy coating doped with SDBS displayed excellent biocidal abilities against Staphylococcus aureus. The polypyrrole coatings on carbon steels with dual function of anti-corrosion and excellent biocidal properties shows great potential application in the industry for anti-corrosion/antimicrobial purposes.

Biofilm formation and biocides sensitivity of Pseudomonas marginalis isolated from a maple sap collection system.

PubMed

Lagacé, L; Jacques, M; Mafu, A A; Roy, D

2006-10-01

The susceptibility of planktonic and biofilm cells of Pseudomonas marginalis toward four commonly used biocides at different temperatures (15 and 30 degrees C) and biofilm growth times (24 and 48 h) was assessed. Using the MBEC biofilm device, biofilm production in maple sap was shown to be highly reproducible for each set of conditions tested. Biofilm formation was influenced by growth temperature and time. A temperature of 15 degrees C and incubation time of 24 h yielded fewer CFU per peg and showed fewer adhered cells and typical biofilm structures, based on scanning electron microscopy observations as compared with other conditions. Minimal biofilm eradication concentration values for P. marginalis were significantly greater (P. < 0.001) than were MBCs for planktonic cells and for every biocide tested, with the exception of minimal biofilm eradication concentration values for peracetic acid at 15 degrees C and 24 h. Sodium hypochlorite and peracetic acid sanitizers were able to eliminate P. marginalis biofilms at lower concentrations as compared with hydrogen peroxide- and quaternary ammonium-based sanitizers (P < 0.001). According to the results obtained, sodium hypochlorite and peracetic acid sanitizers would be more appropriate for maple sap collection system sanitation.

Legionella in Puerto Rico cooling towers

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

Negron-Alviro, A.; Perez-Suarez, I.; Hazen, T.C.

1988-12-31

Water samples from air conditioning cooling towers receiving different treatment protocols on five large municipal buildings in San Juan, Puerto Rico were assayed for various species and serogroups of Legionella spp. using direct immunofluorescence. Several water quality parameters were also measured with each sample. Guinea pigs were inoculated with water samples to confirm pathogenicity and recover viable organisms. Legionella pneumophila (1-6), L. bozemanii, L. micdadei, L. dumoffii, and L. gormanii were observed in at least one of the cooling towers. L. pneumophila was the most abundant species, reaching 10{sup 5} cells/ml, within the range that is considered potentially pathogenic tomore » humans. A significantly higher density of L. pneumophila was observed in the cooling tower water that was not being treated with biocides. Percent respiration (INT) and total cell activity (AODC), were inversely correlated with bacterial density. This study demonstrates that Legionella spp. are present in tropical air-conditioning cooling systems, and without continuous biocide treatment may reach densities that present a health risk.« less

Induction of Fatty Acid Composition Modifications and Tolerance to Biocides in Salmonella enterica Serovar Typhimurium by Plant-Derived Terpenes▿

PubMed Central

Dubois-Brissonnet, Florence; Naïtali, Murielle; Mafu, Akier Assanta; Briandet, Romain

2011-01-01

To enhance food safety and stability, the food industry tends to use natural antimicrobials such as plant-derived compounds as an attractive alternative to chemical preservatives. Nonetheless, caution must be exercised in light of the potential for bacterial adaptation to these molecules, a phenomenon previously observed with other antimicrobials. The aim of this study was to characterize the adaptation of Salmonella enterica serovar Typhimurium to sublethal concentrations of four terpenes extracted from aromatic plants: thymol, carvacrol, citral, and eugenol, or combinations thereof. Bacterial adaptation in these conditions was demonstrated by changes in membrane fatty acid composition showing (i) limitation of the cyclization of unsaturated fatty acids to cyclopropane fatty acids when cells entered the stationary phase and (ii) bacterial membrane saturation. Furthermore, we demonstrated an increased cell resistance to the bactericidal activity of two biocides (peracetic acid and didecyl dimethyl ammonium bromide). The implications of membrane modifications in terms of hindering the penetration of antimicrobials through the bacterial membrane are discussed. PMID:21131520

Phytochemical profiling as a solution to palliate disinfectant limitations.

PubMed

Malheiro, J; Gomes, I; Borges, A; Bastos, M M S M; Maillard, J-Y; Borges, F; Simões, M

2016-10-01

The indiscriminate use of biocides for general disinfection has contributed to the increased incidence of antimicrobial tolerant microorganisms. This study aims to assess the potential of seven phytochemicals (tyrosol, caffeic acid, ferulic acid, cinnamaldehyde, coumaric acid, cinnamic acid and eugenol) in the control of planktonic and sessile cells of Staphylococcus aureus and Escherichia coli. Cinnamaldehyde and eugenol showed antimicrobial properties, minimum inhibitory concentrations of 3-5 and 5-12 mM and minimum bactericidal concentrations of 10-12 and 10-14 mM against S. aureus and E. coli, respectively. Cinnamic acid was able to completely control adhered bacteria with effects comparable to peracetic acid and sodium hypochlorite and it was more effective than hydrogen peroxide (all at 10 mM). This phytochemical caused significant changes in bacterial membrane hydrophilicity. The observed effectiveness of phytochemicals makes them interesting alternatives and/or complementary products to commonly used biocidal products. Cinnamic acid is of particular interest for the control of sessile cells.

Evaluation of sessile microorganisms in pipelines and cooling towers of some Iranian industries

NASA Astrophysics Data System (ADS)

Setareh, M.; Javaherdashti, R.

2006-02-01

Microbiologically influenced corrosion (MIC) is a kind of electrochemical corrosion that is enhanced by the effect of certain microorganisms including sessile bacteria. In this investigation, more than 200 samples collected from different systems of Iranian refineries have been examined (by culturing methods and observations) for corrosion-enhancing, biofilm-producing microorganisms such as sulfate-reducing bacteria (SRB), iron-oxidizing bacteria (IOB), heterotrophic biofilm-forming bacteria (HBB), and some eukaryotes such as fungi. This study showed the presence of microorganisms, such as SRB, HBB, thermophillic HBB, and yeasts, except for IOB. It was also revealed that biocides are used to reduce the number of planktonic (floating) bacteria, instead of the number of sessile bacteria, that form biofilms. Using surfactants, or washing with chemicals like chlorine or organic acids in overhauls, may destroy the biofilm and free the residential bacteria into the bulk solution, thus exposing them to the biocide. For thick biofilms, a chlorine or acid wash may also yield the same results.

Determination of diffusion coefficients of biocides on their passage through organic resin-based renders.

PubMed

Styszko, Katarzyna; Kupiec, Krzysztof

2016-10-01

In this study the diffusion coefficients of isoproturon, diuron and cybutryn in acrylate and silicone resin-based renders were determined. The diffusion coefficients were determined using measuring concentrations of biocides in the liquid phase after being in contact with renders for specific time intervals. The mathematical solution of the transient diffusion equation for an infinite plate contacted on one side with a limited volume of water was used to calculate the diffusion coefficient. The diffusion coefficients through the acrylate render were 8.10·10(-9) m(2) s(-1) for isoproturon, 1.96·10(-9) m(2) s(-1) for diuron and 1.53·10(-9) m(2) s(-1) for cybutryn. The results for the silicone render were lower by one order of magnitude. The compounds with a high diffusion coefficient for one polymer had likewise high values for the other polymer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Colorimetric Solid Phase Extraction (CSPE): Using Color to Monitor Spacecraft Water Quality

NASA Technical Reports Server (NTRS)

Gazda, Daniel B.; Nolan, Daniel J.; Rutz, Jeffrey A.; Schultz, John R.; Siperko, Lorraine M.; Porter, Marc D.; Lipert, Robert J.; Flint, Stephanie M.; McCoy, J. Torin

2010-01-01

In August 2009, an experimental water quality monitoring kit based on Colorimetric Solid Phase Extraction (CSPE) technology was delivered to the International Space Station (ISS). The kit, called the Colorimetric Water Quality Monitoring Kit (CWQMK), was launched as a Station Development Test Objective (SDTO) experiment to evaluate the suitability of CSPE technology for routine use monitoring water quality on the ISS. CSPE is a sorption-spectrophotometric technique that combines colorimetric reagents, solid-phase extraction, and diffuse reflectance spectroscopy to quantify trace analytes in water samples. In CSPE, a known volume of sample is metered through a membrane disk that has been impregnated with an analyte-specific colorimetric reagent and any additives required to optimize the formation of the analyte-reagent complex. As the sample flows through the membrane disk, the target analyte is selectively extracted, concentrated, and complexed. Formation of the analyte-reagent complex causes a detectable change in the color of the membrane disk that is proportional to the amount of analyte present in the sample. The analyte is then quantified by measuring the color of the membrane disk surface using a hand-held diffuse reflectance spectrophotometer (DRS). The CWQMK provides the capability to measure the ionic silver (Ag +) and molecular iodine (I2) in water samples on-orbit. These analytes were selected for the evaluation of CSPE technology because they are the biocides used in the potable water storage and distribution systems on the ISS. Biocides are added to the potable water systems on spacecraft to inhibit microbial growth. On the United States (US) segment of the ISS molecular iodine serves as the biocide, while the Russian space agency utilizes silver as a biocide in their systems. In both cases, the biocides must be maintained at a level sufficient to control bacterial growth, but low enough to avoid any negative effects on crew health. For example, the presence of high levels of iodine in water can cause taste and odor issues that result in decreased water consumption by the crew. There are also concerns about potential impacts on thyroid function following exposure to high levels of iodine. With silver, there is a risk of developing argyria, an irreversible blue-gray discoloration of the skin, associated with long term consumption of water containing high concentrations of silver. The need to ensure that safe, effective levels of biocide are maintained in the potable water systems on the ISS provides a perfect platform for evaluating the suitability of CSPE technology for in-flight water quality monitoring. This paper provides an overview of CSPE technology and details on the silver and iodine methods used in the CWQMK. It also reports results obtained during in-flight analyses performed with the CWQMK and briefly discusses other potential applications for CSPE technology in both the spacecraft and terrestrial environments.

Critical physiological factors influencing the outcome of antimicrobial testing according to ISO 22196 / JIS Z 2801.

PubMed

Wiegand, Cornelia; Völpel, Andrea; Ewald, Andrea; Remesch, Markko; Kuever, Jan; Bauer, Janine; Griesheim, Stefanie; Hauser, Carolin; Thielmann, Julian; Tonndorf-Martini, Silke; Sigusch, Bernd W; Weisser, Jürgen; Wyrwa, Ralf; Elsner, Peter; Hipler, Uta-Christina; Roth, Martin; Dewald, Carolin; Lüdecke-Beyer, Claudia; Bossert, Jörg

2018-01-01

Bactericidal materials gained interest in the health care sector as they are capable of preventing material surfaces from microbial colonization and subsequent spread of infections. However, commercialization of antimicrobial materials requires proof of their efficacy, which is usually done using in vitro methods. The ISO 22196 standard (Japanese test method JIS Z 2801) is a method for measuring the antibacterial activity of daily goods. As it was found reliable for testing the biocidal activity of antimicrobially active materials and surface coatings most of the laboratories participating in this study used this protocol. Therefore, a round robin test for evaluating antimicrobially active biomaterials had to be established. To our knowledge, this is the first report on inaugurating a round robin test for the ISO 22196 / JIS Z 2801. The first round of testing showed that analyses in the different laboratories yielded different results, especially for materials with intermediate antibacterial effects distinctly different efficacies were noted. Scrutinizing the protocols used by the different participants and identifying the factors influencing the test outcomes the approach was unified. Four critical factors influencing the outcome of antibacterial testing were identified in a series of experiments: (1) incubation time, (2) bacteria starting concentration, (3) physiological state of bacteria (stationary or exponential phase of growth), and (4) nutrient concentration. To our knowledge, this is the first time these parameters have been analyzed for their effect on the outcome of testing according to ISO 22196 / JIS Z 2801. In conclusion, to enable assessment of the results obtained it is necessary to evaluate these single parameters in the test protocol carefully. Furthermore, uniform and robust definitions of the terms antibacterial efficacy / activity, bacteriostatic effects, and bactericidal action need to be agreed upon to simplify communication of results and also regulate expectations regarding antimicrobial tests, outcomes, and materials.

Critical physiological factors influencing the outcome of antimicrobial testing according to ISO 22196 / JIS Z 2801

PubMed Central

Völpel, Andrea; Ewald, Andrea; Remesch, Markko; Kuever, Jan; Bauer, Janine; Griesheim, Stefanie; Hauser, Carolin; Thielmann, Julian; Tonndorf-Martini, Silke; Sigusch, Bernd W.; Weisser, Jürgen; Wyrwa, Ralf; Elsner, Peter; Hipler, Uta-Christina; Roth, Martin; Dewald, Carolin; Lüdecke-Beyer, Claudia; Bossert, Jörg

2018-01-01

Bactericidal materials gained interest in the health care sector as they are capable of preventing material surfaces from microbial colonization and subsequent spread of infections. However, commercialization of antimicrobial materials requires proof of their efficacy, which is usually done using in vitro methods. The ISO 22196 standard (Japanese test method JIS Z 2801) is a method for measuring the antibacterial activity of daily goods. As it was found reliable for testing the biocidal activity of antimicrobially active materials and surface coatings most of the laboratories participating in this study used this protocol. Therefore, a round robin test for evaluating antimicrobially active biomaterials had to be established. To our knowledge, this is the first report on inaugurating a round robin test for the ISO 22196 / JIS Z 2801. The first round of testing showed that analyses in the different laboratories yielded different results, especially for materials with intermediate antibacterial effects distinctly different efficacies were noted. Scrutinizing the protocols used by the different participants and identifying the factors influencing the test outcomes the approach was unified. Four critical factors influencing the outcome of antibacterial testing were identified in a series of experiments: (1) incubation time, (2) bacteria starting concentration, (3) physiological state of bacteria (stationary or exponential phase of growth), and (4) nutrient concentration. To our knowledge, this is the first time these parameters have been analyzed for their effect on the outcome of testing according to ISO 22196 / JIS Z 2801. In conclusion, to enable assessment of the results obtained it is necessary to evaluate these single parameters in the test protocol carefully. Furthermore, uniform and robust definitions of the terms antibacterial efficacy / activity, bacteriostatic effects, and bactericidal action need to be agreed upon to simplify communication of results and also regulate expectations regarding antimicrobial tests, outcomes, and materials. PMID:29558480

Photodegradation of octylisothiazolinone and semi-field emissions from facade coatings

NASA Astrophysics Data System (ADS)

Bollmann, Ulla E.; Minelgaite, Greta; Schlüsener, Michael; Ternes, Thomas A.; Vollertsen, Jes; Bester, Kai

2017-01-01

Amongst others, 2-octyl-isothiazol-3(2 H)-one (OIT) is used as film preservative in water-based polymer resin paints and renders to prevent the growth of moulds and bacteria. It is known that biocides leach from facades with rainwater and end up in the environment via stormwater runoff. In the present study the leaching and fate of OIT used in facade coatings was determined under natural conditions. Potential phototransformation products were initially identified in laboratory experiments using UV-light. Afterwards, the leaching of OIT and seven degradation products were studied on artificial walls equipped with organic top coatings formulated with OIT. A mass balance, including the leached and remaining amounts of OIT and its seven transformation products, can explain up to 40% of the initial amount of OIT. The OIT remaining in the material after 1.5 yr is by far the largest fraction. The study shows that in the assessment of biocides in coating material, transformation products need to be taken into account both in leachate and remaining in the material. Furthermore, in case of volatile degradation products, the emissions to air might be relevant.

Photodegradation of octylisothiazolinone and semi-field emissions from facade coatings.

PubMed

Bollmann, Ulla E; Minelgaite, Greta; Schlüsener, Michael; Ternes, Thomas A; Vollertsen, Jes; Bester, Kai

2017-01-27

Amongst others, 2-octyl-isothiazol-3(2 H)-one (OIT) is used as film preservative in water-based polymer resin paints and renders to prevent the growth of moulds and bacteria. It is known that biocides leach from facades with rainwater and end up in the environment via stormwater runoff. In the present study the leaching and fate of OIT used in facade coatings was determined under natural conditions. Potential phototransformation products were initially identified in laboratory experiments using UV-light. Afterwards, the leaching of OIT and seven degradation products were studied on artificial walls equipped with organic top coatings formulated with OIT. A mass balance, including the leached and remaining amounts of OIT and its seven transformation products, can explain up to 40% of the initial amount of OIT. The OIT remaining in the material after 1.5 yr is by far the largest fraction. The study shows that in the assessment of biocides in coating material, transformation products need to be taken into account both in leachate and remaining in the material. Furthermore, in case of volatile degradation products, the emissions to air might be relevant.

Photodegradation of octylisothiazolinone and semi-field emissions from facade coatings

PubMed Central

Bollmann, Ulla E.; Minelgaite, Greta; Schlüsener, Michael; Ternes, Thomas A.; Vollertsen, Jes; Bester, Kai

2017-01-01

Amongst others, 2-octyl-isothiazol-3(2 H)-one (OIT) is used as film preservative in water-based polymer resin paints and renders to prevent the growth of moulds and bacteria. It is known that biocides leach from facades with rainwater and end up in the environment via stormwater runoff. In the present study the leaching and fate of OIT used in facade coatings was determined under natural conditions. Potential phototransformation products were initially identified in laboratory experiments using UV-light. Afterwards, the leaching of OIT and seven degradation products were studied on artificial walls equipped with organic top coatings formulated with OIT. A mass balance, including the leached and remaining amounts of OIT and its seven transformation products, can explain up to 40% of the initial amount of OIT. The OIT remaining in the material after 1.5 yr is by far the largest fraction. The study shows that in the assessment of biocides in coating material, transformation products need to be taken into account both in leachate and remaining in the material. Furthermore, in case of volatile degradation products, the emissions to air might be relevant. PMID:28128314

Risk assessment of herbicides and booster biocides along estuarine continuums in the Bay of Vilaine area (Brittany, France).

PubMed

Caquet, Th; Roucaute, M; Mazzella, N; Delmas, F; Madigou, C; Farcy, E; Burgeot, Th; Allenou, J-P; Gabellec, R

2013-02-01

A 2-year study was implemented to characterize the contamination of estuarine continuums in the Bay of Vilaine area (NW Atlantic Coast, Southern Brittany, France) by 30 pesticide and biocide active substances and metabolites. Among these, 11 triazines (ametryn, atrazine, desethylatrazine, desethylterbuthylazine, desisopropyl atrazine, Irgarol 1051, prometryn, propazine, simazine, terbuthylazine, and terbutryn), 10 phenylureas (chlortoluron, diuron, 1-(3,4-dichlorophenyl)-3-methylurea, fenuron, isoproturon, 1-(4-isopropylphenyl)-3-methylurea, 1-(4-isopropylphenyl)-urea, linuron, metoxuron, and monuron), and 4 chloroacetanilides (acetochlor, alachlor, metolachlor, and metazachlor) were detected at least once. The objectives were to assess the corresponding risk for aquatic primary producers and to provide exposure information for connected studies on the responses of biological parameters in invertebrate sentinel species. The risk associated with contaminants was assessed using risk quotients based on the comparison of measured concentrations with original species sensitivity distribution-derived hazardous concentration values. For EU Water Framework Directive priority substances, results of monitoring were also compared with regulatory Environmental Quality Standards. The highest residue concentrations and risks for primary producers were recorded for diuron and Irgarol 1051 in Arzal reservoir, close to a marina. Diuron was present during almost the all survey periods, whereas Irgarol 1051 exhibited a clear seasonal pattern, with highest concentrations recorded in June and July. These results suggest that the use of antifouling biocides is responsible for a major part of the contamination of the lower part of the Vilaine River course for Irgarol 1051. For diuron, agricultural sources may also be involved. The presence of isoproturon and chloroacetanilide herbicides on some dates indicated a significant contribution of the use of plant protection products in agriculture to the contamination of Vilaine River. Concentration levels and associated risk were always lower in estuarine sites than in the reservoir, suggesting that Arzal dam reduces downstream transfer of contaminants and favors their degradation in the freshwater part of the estuary. Results of the additional monitoring of two tidal streams located downstream of Arzal dam suggested that, although some compounds may be transferred to the estuary, their impact was probably very low. Dilution by marine water associated with tidal current was also a major factor of concentration reduction. It is concluded that the highest risks associated to herbicides and booster biocides concerned the freshwater part of the estuary and that its brackish/saltwater part was exposed to a moderate risk, although some substances may sometimes exhibit high concentration but mainly at low tide and on an irregular basis.

Removal of Burkholderia cepacia biofilms with oxidants

NASA Technical Reports Server (NTRS)

Koenig, D. W.; Mishra, S. K.; Pierson, D. L.

1995-01-01

Iodine is used to disinfect the water system aboard US space shuttles and is the anticipated biocide for the international space station. Water quality on spacecraft must be maintained at the highest possible levels for the safety of the crew. Furthermore, the treatment process used to maintain the quality of water on research must be robust and operate for long periods with minimal crew intervention. Biofilms are recalcitrant and pose a major threat with regard to chronic contamination of spacecraft water systems. We measured the effectiveness of oxidizing biocides on the removal and regrowth of Burkholderia (Pseudomonas) cepacia biofilms. B. cepacia, isolated from the water distribution system of the space shuttle Discovery, was grown in continuous culture to produce a bacterial contamination source for biofilm formation and removal studies. A 10(7) CFU ml-1 B. cepacia suspension, in distilled water, was used to form biofilms on 3000 micrometers2 glass surfaces. Rates of attachment were measured directly with image analysis and were found to be 7.8, 15.2, and 22.8 attachment events h-1 for flow rates of 20.7, 15.2, and 9.8 ml min-1, respectively. After 18 h of formation, the B. cepacia biofilms were challenged with oxidants (ozone, chlorine, and iodine) and the rates of biofilm removal determined by image analysis. Fifty percent of the biofilm material was removed in the first hour of continous treatment with 24 mg l-1 chlorine or 2 mg l-1 ozone. Iodine (48 mg l-1) did not remove any measurable cellular material after 6 h continuous contact. After this first removal of biofilms by the oxidants, the surface was allowed to refoul and was again treated with the biocide. Iodine was the only compound that was unable to remove cellular debris from either primary or secondary biofilms. Moreover, treating primary biofilms with iodine increased the rate of formation of secondary biofilms, from 4.4 to 5.8 attachment events h-1. All the oxidants tested inactivated the B. cepacia associated with both primary and secondary biofilms. The amount of biocide needed to inactivate 50% of planktonic B. cepacia in 10 min at 25 degrees C was 8.4, 0.5, and 0.2 mg l-1 for iodine, chlorine, and ozone, respectively. The data suggest that iodine maynot be the best chemical for treating of biofilms when removal of cellular material is required.

Iodine-Rich Imidazolium Iodate and Periodate Salts: En Route to Single-Based Biocidal Agents.

PubMed

He, Chunlin; Hooper, Joseph P; Shreeve, Jean'ne M

2016-12-19

Two classes of iodine-rich salts that consist of iodine-rich cations and iodate (IO 3 - ) or periodate (IO 4 - ) anions were synthesized. The synthesis of analogous I 3 O 8 - salts was more difficult because of poor solubility and hydrolytic instability. All iodine-rich salts were fully characterized by infrared, 1 H nuclear magnetic resonance, and 13 C nuclear magnetic resonance spectroscopy as well as elemental analyses. The molecular structures of compounds 15 and 24 were elucidated by X-ray single-crystal diffraction. Additionally, the heats of formation were calculated with Gaussian 03. The detonation properties and biocidal efficiency were calculated and evaluated using CHEETAH 7.

Regulatory requirements for biocides on the market in the European Union according to Directive 98/8/EC.

PubMed

Rasmussen, K; Chemin, P; Haastrup, P

1999-06-30

In early 1998, the European Commission and Parliament adopted a new Directive concerning the placing on the market of biocidal products. The Directive is to be implemented in the member states by May 2000. The member states are currently concerned with the national implementation into legislation whereas the Commission is setting up the proposal for a review programme for the existing active substances and the products in which they are used. This paper describes the effort currently undertaken (up to the end of December 1998) to define the procedures to be used and characterise the substances covered. Copyright 1999 Elsevier Science B.V.

How to control bio-slime in condenser cooling system water

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

Freymark, S.

1979-08-01

A number of oxidizing and non-oxidizing biocides are currently used for biocontrol. However, yesterday's solution to slime-fouling problems may not apply today in view of tightening effluent restrictions on chlorine. Thus, selection of biocontrol compounds can not be made indiscriminately. In selecting alternative biocontrol compounds, consideration should be given not only to costs but to effectiveness of the biocide in each particular application, taking into consideration cooling water quality, type of microbiological fouling and discharge restrictions. Thoughtful selection of the biocontrol compound(s), alone or in combination with surface-active agents, is essential for maintaining maximum microbiological control in condenser cooling watermore » systems.« less

Antibacterial and antiviral study of dialdehyde polysaccharides

NASA Astrophysics Data System (ADS)

Song, Le

Concerns for microbial contamination and infection to the general population, especially the spread of drug-resistant microorganisms, have greatly increased. Polymeric biocides have been found to be a feasible strategy to inactivate drug-resistant bacteria. However, current polymeric biocide systems involve multi-step chemical reactions and they are not cost-effective. Desirable antimicrobial systems need to be designed to be environmentally friendly, broad-spectrum effective against microorganisms, flexible for various delivery methods and economically affordable. We demonstrated that dialdehyde polysaccharides (including dialdehyde starch and dialdehdye cellulose) were broad-spectrum polymeric biocides against gram-positive/negative bacteria, bacteriophages and human virus. These polymers can be easily converted from starch and cellulose through one-step periodate oxidation. Destructions of microorganism by dialdehyde polysaccharides have been achieved in aqueous suspension or by solid surface contact. The dialdehdye functions of dialdehdye polysaccharides were found to be the dominant action against microorganism. The reactivity of the dialdehyde functionality was found to be pH-dependent as well as related to the dispersion of dialdehyde polysaccharides. Degradation of dialdehyde starch during cooking was confirmed. Degradation of dialdehyde starch was more liable in alkaline condition. Carboxylic acid and conjugated aldehyde functionalities were the two main degradation products, confirmed from the spectroscopic studies. The pH effect on the polysaccharide structure and the corresponding antimicrobial activity was very complicated. No decisive conclusions could be obtained from this study. Liner inactivation kinetics was found for dialdehyde starch aqueous suspension against bacteria. This linear inactivation kinetics was derived from the pseudo-first chemical reaction between the dialdehyde starch and the bacteria. The established inactivation kinetics was successfully predicated the response of bacteria to dialdehyde starch with time. Inactivation of bacteria by dialdehyde starch was speculated to be the crosslinking-interaction between the dialdehyde starch and the bacterial surface. Amino groups of bacterial surfaces were blocked by dialdehyde starch. This crosslinking action was also suggested from the preliminary study of the bacterial dehydrogenase activity. However, membrane damage was found in the dialdehdye starch treated bacteria from the fluorescent study.

How representative is pesticide monitoring in Swiss streams?

NASA Astrophysics Data System (ADS)

Munz, Nicole; Wittmer, Irene; Strahm, Ivo; Leu, Christian; Stamm, Christian

2013-04-01

The surveillance of surface water quality in Switzerland is the task of the 26 cantons. This includes the assessment of the level of pesticide pollution. Each of the cantons may follow different procedures, which makes a comparison difficult and cumbersome. Nevertheless, in this study presents the main results of the first nation-wide compilation and interpretation of cantonal and federal monitoring data as well as results from specific research projects on agricultural and urban pesticides are presented. Overall, more than 345'000 concentration data of 281 biocidal compounds have been analyzed. This set of substances includes 203 compounds that have been registered either only as agricultural plant protection (N = 149) product or only as urban biocide (N = 18), but also some (N = 36) which were registered for both uses. This data set contains 70 out of the 100 most sold agricultural plant protection products in 2010. A comparable assessment for the representativeness of the biocide data is hardly possible due to a lack of systematic use data. The data stem from 565 measuring sites. However, these sites are not representative for all size classes of the Swiss stream network. While about 75% of the total length of the stream network is made up by small streams (Strahler order 1 and 2), only 28% of the measuring sites are located on such streams. In combination with the sampling strategies that have been used - about 50% grab samples and 50% composite samples - it can be concluded that the 2% of measured values > 100 ng L-1 most probably severely underestimates the true level of pesticide pollution in the Swiss stream network. In the future, more emphasis has to be put on small streams, where higher concentrations are expected and thus also actual ecological effects.

Long-term biobarriers to plant and animal intrusions of uranium tailings. [24% trifluralin, 18% carbon black, and 58% polymer

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

Cline, J.F.; Burton, F.G.; Cataldo, D.A.

1982-09-01

The objective of this project was to develop and evaluate the effectiveness of physical and chemical barriers designed to prevent plant and animal breachment of uranium mill tailings containment systems for an extended period of time. A polymeric carrier/biocide delivery system was developed and tested in the laboratory, greenhouse and field. A continuous flow technique was established to determine the release rates of the biocides from the PCD systems; polymeric carrier specifications were established. Studies were conducted to determine effective biocide concentrations required to produce a phytotoxic response and the relative rates of phytotoxin degradation resulting from chemical and biologicalmore » breakdown in soils. The final PCD system developed was a pelletized system containing 24% trifluralin, 18% carbon black and 58% polymer. Pellets were placed in the soil at the Grand Junction U-tailings site at one in. and two in. intervals. Data obtained in the field determined that the pellets released enough herbicide to the soil layer to stop root elongation past the barrier. Physical barriers to subsurface movement of burrowing animals were investigated. Small crushed stone (1 to 1 1/2 in. diameter) placed over asphalt emulsion and multilayer soil seals proved effective as barriers to a small mammal (ground squirrels) but were not of sufficient size to stop a larger animal (the prairie dog). No penetrations were made through the asphalt emulsion or the clay layer of the multilayer soil seals by either of the two mammals tested. A literature survey was prepared and published on the burrowing habits of the animals that may be found at U-tailings sites.« less

Evaluating the environmental hazard of industrial chemicals from data collected during the REACH registration process.

PubMed

Gustavsson, Mikael B; Hellohf, Andreas; Backhaus, Thomas

2017-05-15

Registration dossiers for 11,678 industrial chemicals were retrieved from the database of the European Chemicals Agency, of which 3566 provided a numerical entry for the corresponding predicted no effect concentration for the freshwater environment (PNEC). A distribution-based examination of 2244 of these entries reveals that the average PNEC of an industrial chemical in Europe is 238nmol/L, covering a span of 9 orders of magnitude. A comparison with biocides, pesticides, pharmaceuticals and WFD-priority pollutants reveals that, in average, industrial chemicals are least hazardous (hazard ranking: industrial chemicals≪pharmaceuticals

The effect of the molecular orientation on the release of antimicrobial substances from uniaxially drawn polymer matrixes.

PubMed

Iconomopoulou, S M; Voyiatzis, G A

2005-03-21

A new method of controlled release of low molecular weight biocides incorporated in polymer matrixes is described. The molecular orientation of uniaxially drawn biocide doped polymer films is suggested as a significant parameter for controlled release monitoring. Triclosan, a well-established widespread antibacterial agent, has been incorporated into high density polyethylene (HDPE) films that have been subsequently uniaxially drawn at different draw ratios. The molecular orientation developed was estimated utilizing polarized mu-Raman spectra. Biocide incorporated polymer films, drawn at different draw ratios, have been immersed in ethanol-water solutions (EtOH) and in physiological saline. The release of Triclosan out of the polymer matrix was probed with UV-Vis absorption spectroscopy for a period of time up to 15 months. In all cases, although the film surface of the drawn samples exposed to the liquid solution was higher than the undrawn one, the relevant release rate from the drawn specimens was lower than the non-stretched samples depending on the molecular orientation developed during the drawing process. A note is made of the fact that no significant molecular orientation relaxation of the polyethylene films has been observed even after such a long time of immersion of the drawn films in the liquid solutions.

From Broad-Spectrum Biocides to Quorum Sensing Disruptors and Mussel Repellents: Antifouling Profile of Alkyl Triphenylphosphonium Salts

PubMed Central

Martín-Rodríguez, Alberto J.; Babarro, Jose M. F.; Lahoz, Fernando; Sansón, Marta; Martín, Víctor S.; Norte, Manuel; Fernández, José J.

2015-01-01

‘Onium’ compounds, including ammonium and phosphonium salts, have been employed as antiseptics and disinfectants. These cationic biocides have been incorporated into multiple materials, principally to avoid bacterial attachment. In this work, we selected 20 alkyl-triphenylphosphonium salts, differing mainly in the length and functionalization of their alkyl chains, in fulfilment of two main objectives: 1) to provide a comprehensive evaluation of the antifouling profile of these molecules with relevant marine fouling organisms; and 2) to shed new light on their potential applications, beyond their classic use as broad-spectrum biocides. In this regard, we demonstrate for the first time that these compounds are also able to act as non-toxic quorum sensing disruptors in two different bacterial models (Chromobacterium violaceum and Vibrio harveyi) as well as repellents in the mussel Mytilus galloprovincialis. In addition, their inhibitory activity on a fouling-relevant enzymatic model (tyrosinase) is characterized. An analysis of the structure-activity relationships of these compounds for antifouling purposes is provided, which may result useful in the design of targeted antifouling solutions with these molecules. Altogether, the findings reported herein provide a different perspective on the biological activities of phosphonium compounds that is particularly focused on, but, as the reader will realize, is not limited to their use as antifouling agents. PMID:25897858

Downhole Transformation of the Hydraulic Fracturing Fluid Biocide Glutaraldehyde: Implications for Flowback and Produced Water Quality.

PubMed

Kahrilas, Genevieve A; Blotevogel, Jens; Corrin, Edward R; Borch, Thomas

2016-10-18

Hydraulic fracturing fluid (HFF) additives are used to enhance oil and gas extraction from unconventional shale formations. Several kilometers downhole, these organic chemicals are exposed to temperatures up to 200 °C, pressures above 10 MPa, high salinities, and a pH range from 5-8. Despite this, very little is known about the fate of HFF additives under these extreme conditions. Here, stainless steel reactors are used to simulate the downhole chemistry of the commonly used HFF biocide glutaraldehyde (GA). The results show that GA rapidly (t 1/2 < 1 h) autopolymerizes, forming water-soluble dimers and trimers, and eventually precipitates out at high temperatures (∼140 °C) and/or alkaline pH. Interestingly, salinity was found to significantly inhibit GA transformation. Pressure and shale did not affect GA transformation and/or removal from the bulk fluid. On the basis of experimental pseudo-second-order rate constants, a kinetic model for GA downhole half-life predictions for any combination of these conditions within the limits tested was developed. These findings illustrate that the biocidal GA monomer has limited time to control microbial activity in hot and/or alkaline shales, and may return along with its aqueous transformation products to the surface via flowback and produced water in cooler, more acidic, and saline shales.

Glyceryl trinitrate and caprylic acid for the mitigation of the Desulfovibrio vulgaris biofilm on C1018 carbon steel.

PubMed

Li, Y; Zhang, P; Cai, W; Rosenblatt, J S; Raad, I I; Xu, D; Gu, T

2016-02-01

Microbiologically influenced corrosion (MIC), also known as biocorrosion, is caused by corrosive biofilms. MIC is a growing problem, especially in the oil and gas industry. Among various corrosive microbes, sulfate reducing bacteria (SRB) are often the leading culprit. Biofilm mitigation is the key to MIC mitigation. Biocide applications against biofilms promote resistance over time. Thus, it is imperative to develop new biodegradable and cost-effective biocides for large-scale field applications. Using the corrosive Desulfovibrio vulgaris (an SRB) biofilm as a model biofilm, this work demonstrated that a cocktail of glyceryl trinitrate (GTN) and caprylic acid (CA) was very effective for biofilm prevention and mitigation of established biofilms on C1018 carbon steel coupons. The most probable number sessile cell count data and confocal laser scanning microscope biofilm images proved that the biocide cocktail of 25 ppm (w/w) GTN + 0.1% (w/w) CA successfully prevented the D. vulgaris biofilm establishment on C1018 carbon steel coupons while 100 ppm GTN + 0.1% CA effectively mitigated pre-established D. vulgaris biofilms on C1018 carbon steel coupons. In both cases, the cocktails were able to reduce the sessile cell count from 10(6) cells/cm(2) to an undetectable level.

Exploring the sensitivity of the zone of inhibition test for leachable biocides from paper and board food contact materials, and improvements thereof.

PubMed

Castle, L; Kelly, J; Jickells, S M; Johns, S M; Mountfort, K A

2012-01-01

The zone of inhibition method to test the release of biocides from paper and board food contact materials was evaluated. The method tests the paper by placing a small specimen directly onto culture plates of Bacillus subtilis and Aspergillus niger. The principle is that any extractable biocide will diffuse from the paper into the surrounding nutrient medium and so inhibit growth of the microorganism in the vicinity. The test was found to have insufficient sensitivity for assuring food safety, where detection limits for migration at or below the mg l(-1) (parts per million) level are needed. Also, the test does not mimic the actual or foreseeable conditions of use since most paper/board materials are not intended for direct contact with an aqueous medium for up to 3 days at 30°C (B. subtilis) or 25°C (A. niger), which are the incubation conditions used. The sensitivity of the test was increased approximately 100-fold by preparing a concentrated extract of the paper to be tested and applying this extract to the assay via a blank paper carrier. This was done using methanol as a good solvent for most biocides, as a proof of principle. Other solvents or food simulants could be used to mimic the conditions of use intended for the particular paper/board samples under examination, e.g. contact with dry, fatty, aqueous or acidic foods, hot or cold. Twenty-four plain (unconverted) paper and board samples and 100 food packaging samples were evaluated using the modified procedure. The results revealed that the method has been developed to the stage where background cytotoxic action of normal paper constituents gives a weak response. Unlike the original method, therefore, the modified method with its improved sensitivity and the facility to link with the intended food contact conditions may be considered a suitable bioassay screening test to complement chemical analysis of paper/board for composition and migration.

Micro/nanoreservoirs for controlled release of active species in smart functional coatings =

NASA Astrophysics Data System (ADS)

Maia, Frederico Calheiros

This work reports one possible way to develop new functional coatings used to increase the life time of metallic structures. The functionalities selected and attributed to model coatings in the frame of this work were corrosion protection, self-sensing and prevention of fouling (antifouling). The way used to confer those functionalities to coatings was based on the encapsulation of active compounds (corrosion inhibitors, pH indicators and biocides) in micro and nanocontainers followed by their incorporation into the coating matrices. To confer active corrosion protection, one corrosion inhibitor (2-mercaptobenzothiazole, MBT) was encapsulated in two different containers, firstly in silica nanocapsules (SiNC) and in polyurea microcapsules (PU-MC). The incorporation of both containers in different models coatings shows a significant improvement in the corrosion protection of aluminum alloy 2024 (AA2024). Following the same approach, SiNC and PU-MC were also used for the encapsulation of phenolphthalein (one well known pH indicator) to introduce sensing properties in polymeric coatings. SiNC and PU-MC containing phenolphthalein acted as corrosion sensor, showing a pink coloration due to the beginning of cathodic reaction, resulting in a pH increase identified by those capsules. Their sensing performance was proved in suspension and when integrated in coatings for aluminium alloy 2024 and magnesium alloy AZ31. In a similar way, the biocide activity (antifouling) was assigned to two polymeric matrices using SiNC for encapsulation of one biocide (Dichloro-2-octyl-2H-isothiazol-3-one, DCOIT) and also SiNC-MBT was tested as biocide. The antifouling activity of those two encapsulated compounds was assessed through inhibition and consequent decrease in the bioluminescence of modified E. coli. That effect was verified in suspension and when incorporated in coatings for AISI 1008 carbon steel. The developed micro and nanocontainers presented the desired performance, allowing the introduction of new functionalities to model coatings, showing potential to be used as functional additives in the next generation of multifunctional coatings.

The use of poloxamer hydrogels for the assessment of biofilm susceptibility towards biocide treatments.

PubMed

Gilbert, P; Jones, M V; Allison, D G; Heys, S; Maira, T; Wood, P

1998-12-01

Poloxamer F127 is a non-toxic, di-block copolymer of polyoxyethylene and polyoxypropylene. Aqueous solutions (30% w/v) show thermoreversible gelation, being liquid at temperatures < 15 degrees C and robust gels at temperatures > 15 degrees C. Chilled poloxamer (30% in tryptone soya broth) was mixed with an inoculum of Pseudomonas aeruginosa (10(4) cfu ml-1) and placed as 100 microliters drops onto separate glass cover-slips. These were placed into sealed Petri dishes containing moistened cotton wool and incubated at 35 degrees C. Viable counts could be performed on the poloxamer gels by transfer of the coverslips to diluents at < 15 degrees C. Growth curves in the gels and in liquid batch cultures were indistinguishable from one another with stationary phase cell densities, being approximately 5 x 10(10) cfu ml-1 in each at 16 h. SDS-PAGE of cell envelope preparations showed the poloxamer-grown cells to exhibit a biofilm rather than planktonic phenotype. Susceptibility towards various concentrations of chlorhexidine, iodine and hydrogen peroxide was assessed for 10 min at 35 degrees C for suspensions of broth-grown cells and for incubated poloxamer-gels (1 and 16 h). The gels were immersed in biocide, on their glass supports, before transfer to neutralizer at 10 degrees C where dissolution was complete within 5 min. Further serial dilutions and plate counts were made. While modest decreases in susceptibility towards all biocides were associated with incorporation of the inoculum with the gel (1 h incubation), substantial changes were noted after prolonged incubation and adaptation to a biofilm phenotype (16 h incubation). The gel populations mimic the localized high cell densities observed in biofilms and will also be subject to the same nutrient and chemical gradients as found within natural biofilms. Thermoreversible gelation enables complete recovery of the test inoculum without further trauma. They therefore provide an effective model for assessing biofilm susceptibility towards biocides and would be suitable for screening programmes.

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

PubMed

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

2015-02-10

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

Microbiological and near IR studies of leather from hides presoaked in formulations that can remove hardened bovine manure

USDA-ARS?s Scientific Manuscript database

New efficient eco-friendly soaking methods are urgently needed to clean raw hides for storage and shipment abroad of ~ 35M bovine hides produced annually in USA. High concentrations of surfactant(~0.15% w/w) and biocide(~0.10% w/w) in commonly used soaking solution are functional for eliminating mic...

Activity of two strobilurin fungicides against three species of decay fungi in agar plate tests

Treesearch

Juliet D. Tang; Tina Ciaramitaro; Maria Tomaso-Peterson; Susan V. Diehl

2017-01-01

The objective of this study was to examine the toxicity of strobilurin fungicides against wood decay fungi in order to assess their potential to act as a co-biocide for copper-based wood protection. Two strobilurin fungicides, Heritage (50% azoxystrobin active ingredient) and Insignia (20% pyraclostrobin active ingredients), and copper sulfate pentahydrate were tested...

Mechanical performance of a biocompatible biocide soda-lime glass-ceramic.

PubMed

López-Esteban, S; Bartolomé, J F; Dí Az, L A; Esteban-Tejeda, L; Prado, C; López-Piriz, R; Torrecillas, R; Moya, J S

2014-06-01

A biocompatible soda-lime glass-ceramic in the SiO2-Na2O-Al2O3-CaO-B2O3 system containing combeite and nepheline as crystalline phases, has been obtained at 750°C by two different routes: (i) pressureless sintering and (ii) Spark Plasma Sintering. The SPS glass-ceramic showed a bending strength, Weibull modulus, and toughness similar values to the cortical human bone. This material had a fatigue limit slightly superior to cortical bone and at least two times higher than commercial dental glass-ceramics and dentine. The in vitro studies indicate that soda-lime glass-ceramic is fully biocompatible. The in vivo studies in beagle jaws showed that implanted SPS rods presented no inflammatory changes in soft tissues surrounding implants in any of the 10 different cases after four months implantation. The radiological analysis indicates no signs of osseointegration lack around implants. Moreover, the biocide activity of SPS glass-ceramic versus Escherichia coli, was found to be >4log indicating that it prevents implant infections. Because of this, the SPS new glass-ceramic is particularly promising for dental applications (inlay, crowns, etc). Copyright © 2014 Elsevier Ltd. All rights reserved.

A flow-through aqueous standard generation system for thin film microextraction investigations of UV filters and biocides partitioning to different environmental compartments.

PubMed

Ahmadi, Fardin; Sparham, Chris; Pawliszyn, Janusz

2017-11-01

In this paper problems associated with preparation of aqueous standard of highly hydrophobic compounds such as partial precipitation, being lost on the surfaces, low solubility in water and limited sample volume for accurate determination of their distribution coefficients are addressed. The following work presents two approaches that utilize blade thin film microextraction (TFME) to investigate partitioning of UV filters and biocides to humic acid (dissolved organic carbon) and sediment. A steady-state concentration of target analytes in water was generated using a flow-through aqueous standard generation (ASG) system. Dialysis membranes, a polytetrafluoroethylene permeation tube, and a frit porous (0.5 μm) coated by epoxy glue were basic elements used for preparation of the ASG system. In the currently presented study, negligible depletion TFME using hydrophilic-lipophilic balance (HLB) and octadecyl silica-based (C18) sorbents was employed towards the attainment of free concentration values of target analytes in the studied matrices. Thin film geometry provided a large volume of extraction phase, which improved the sensitivity of the method towards highly matrix-bound analytes. Extractions were performed in the equilibrium regime so as to prevent matrix effects and with aims to reach maximum method sensitivity for all analytes under study. Partitioning of analytes on dissolved organic carbon (DOC) was investigated in ASG to facilitate large sample volume conditions. Binding percentages and DOC distribution coefficients (Log K DOC ) ranged from 20 to 98% and 3.71-6.72, respectively. Furthermore, sediment-water partition coefficients (K d ), organic-carbon normalized partition coefficients (Log K OC ), and DOC distribution coefficients (Log K DOC ) were investigated in slurry sediment, and ranged from 33 to 2860, 3.31-5.24 and 4.52-5.75 Lkg -1 , respectively. The obtained results demonstrated that investigations utilizing ASG and TFME can yield reliable binding information for compounds with high log K OW values. This information is useful for study of fate, transport, and ecotoxicological effects of UV filters and biocides in aquatic environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Control of biological growth in recirculating cooling systems using treated secondary effluent as makeup water with monochloramine.

PubMed

Chien, Shih-Hsiang; Chowdhury, Indranil; Hsieh, Ming-Kai; Li, Heng; Dzombak, David A; Vidic, Radisav D

2012-12-01

Secondary-treated municipal wastewater, an abundant and widely distributed impaired water source, is a promising alternative water source for thermoelectric power plant cooling. However, excessive biological growth is a major challenge associated with wastewater reuse in cooling systems as it can interfere with normal system operation as well as enhance corrosion and scaling problems. Furthermore, possible emission of biological aerosols (e.g., Legionella pneumophila) with the cooling tower drift can lead to public health concerns within the zone of aerosol deposition. In this study, the effectiveness of pre-formed and in-situ-formed monochloramine was evaluated for its ability to control biological growth in recirculating cooling systems using secondary-treated municipal wastewater as the only makeup water source. Bench-scale studies were compared with pilot-scale studies for their ability to predict system behavior under realistic process conditions. Effectiveness of the continuous addition of pre-formed monochloramine and monochloramine formed in-situ through the reaction of free chlorine with ammonia in the incoming water was evaluated in terms of biocide residual and its ability to control both planktonic and sessile microbial populations. Results revealed that monochloramine can effectively control biofouling in cooling systems employing secondary-treated municipal wastewater and has advantages relative to use of free chlorine, but that bench-scale studies seriously underestimate biocide dose and residual requirements for proper control of biological growth in full-scale systems. Pre-formed monochloramine offered longer residence time and more reliable performance than in-situ-formed monochloramine due to highly variable ammonia concentration in the recirculating water caused by ammonia stripping in the cooling tower. Pilot-scale tests revealed that much lower dosing rate was required to maintain similar total chlorine residual when pre-formed monochloramine was used as compared to in-situ-formed monochloramine. Adjustment of biocide dose to maintain monochloramine residual above 3mg/L is needed to achieve successful biological growth control in recirculating cooling systems using secondary-treated municipal effluent as the only source of makeup water. Copyright © 2012 Elsevier Ltd. All rights reserved.

Antifouling activities of β-cyclodextrin stabilized peg based silver nanocomposites

NASA Astrophysics Data System (ADS)

Punitha, N.; Saravanan, P.; Mohan, R.; Ramesh, P. S.

2017-01-01

Self-polishing polymer composites which release metal biocide in a controlled rate have been widely used in the design of antimicrobial agents and antifouling coatings. The present work focuses on the environmental friendly green synthesis of PEG based SNCs and their application to biocidal activity including marine biofouling. Biocompatible polymer β-CD and adhesive resistance polymer PEG were used to functionalize the SNPs and the as synthesized SNCs exhibit excellent micro fouling activities. The structural and optical properties were confirmed by XRD and UV-visible techniques respectively. The particle surface and cross sectional characteristics were examined by SEM-EDS, HR-TEM, AFM and FTIR. The surface potential was evaluated using ZP analysis and assessment of antibiofouling property was investigated using static immersion method.

In vitro susceptibility of spiroplasmas to heavy-metal salts.

PubMed

Whitmore, S C; Rissler, J F; Davis, R E

1983-01-01

The susceptibility of six spiroplasma strains to heavy-metal salt was characterized in terms of minimal inhibitory concentrations and minimal biocidal concentrations in broth tube dilution tests. The strains were most susceptible to mercuric chloride and silver nitrate; less susceptible to copper sulfate, cobalt chloride, lead nitrate, and cadmium sulfate; and least susceptible to nickel chloride and zinc sulfate. Spiroplasma citri strains Maroc R8A2 and C189 were the most susceptible to five of eight heavy-metal salts, and honeybee spiroplasma strain AS576 and Spiroplasma floricola strain 23-6 were generally the least susceptible. The difference between the minimal biocidal concentrations and the minimal inhibitory concentrations was greater for certain heavy-metal salts than for others.

New Generation Agent Defeat Weapons: Energetic N,N'-Ethylene-Bridged Polyiodoazoles.

PubMed

Zhao, Gang; Kumar, Dheeraj; He, Chunlin; Hooper, Joseph P; Imler, Gregory H; Parrish, Damon A; Shreeve, Jean'ne M

2017-11-27

Sodium salts of iodine-rich pyrazole and imidazole with 1-(2-bromoethyl)-5-aminotetrazole are useful precursors for energetic N,N'-ethylene-bridged polyiodoazoles. Compounds 1-3 were characterized with IR, and 1 H and 13 C NMR spectroscopy as well as elemental analyses. The molecular structures of 1 and 2 were confirmed by using single crystal X-ray diffraction. Heats of formation were calculated using Gaussian 03 and detonation properties and biocidal efficiency were calculated with CHEETAH 7. The decomposition products of 1-3 destroy microbes more effectively than some previously reported biocides since the thermal decomposition occurs at below 400 °C without addition of oxidizer or combustion adjuvant. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Encapsulation of Antifouling Organic Biocides in Poly(lactic acid) Nanoparticles

PubMed Central

Kamtsikakis, Aristotelis; Kavetsou, Eleni; Chronaki, Konstantina; Kiosidou, Evangelia; Pavlatou, Evangelia; Karana, Alexandra; Papaspyrides, Constantine; Detsi, Anastasia; Karantonis, Antonis; Vouyiouka, Stamatina

2017-01-01

The scope of the current research was to assess the feasibility of encapsulating three commercial antifouling compounds, Irgarol 1051, Econea and Zinc pyrithione, in biodegradable poly(lactic acid) (PLA) nanoparticles. The emulsification–solvent evaporation technique was herein utilized to manufacture nanoparticles with a biocide:polymer ratio of 40%. The loaded nanoparticles were analyzed for their size and size distribution, zeta potential, encapsulation efficiency and thermal properties, while the relevant physicochemical characteristics were correlated to biocide–polymer system. In addition, the encapsulation process was scaled up and the prepared nanoparticles were dispersed in a water-based antifouling paint in order to examine the viability of incorporating nanoparticles in such coatings. Metallic specimens were coated with the nanoparticles-containing paint and examined regarding surface morphology. PMID:28952560

Evaluation of zosteric acid for mitigating biofilm formation of Pseudomonas putida isolated from a membrane bioreactor system.

PubMed

Polo, Andrea; Foladori, Paola; Ponti, Benedetta; Bettinetti, Roberta; Gambino, Michela; Villa, Federica; Cappitelli, Francesca

2014-05-28

This study provides data to define an efficient biocide-free strategy based on zosteric acid to counteract biofilm formation on the membranes of submerged bioreactor system plants. 16S rRNA gene phylogenetic analysis showed that gammaproteobacteria was the prevalent taxa on fouled membranes of an Italian wastewater plant. Pseudomonas was the prevalent genus among the cultivable membrane-fouler bacteria and Pseudomonas putida was selected as the target microorganism to test the efficacy of the antifoulant. Zosteric acid was not a source of carbon and energy for P. putida cells and, at 200 mg/L, it caused a reduction of bacterial coverage by 80%. Biofilm experiments confirmed the compound caused a significant decrease in biomass (-97%) and thickness (-50%), and it induced a migration activity of the peritrichous flagellated P. putida over the polycarbonate surface not amenable to a biofilm phenotype. The low octanol-water partitioning coefficient and the high water solubility suggested a low bioaccumulation potential and the water compartment as its main environmental recipient and capacitor. Preliminary ecotoxicological tests did not highlight direct toxicity effects toward Daphnia magna. For green algae Pseudokirchneriella subcapitata an effect was observed at concentrations above 100 mg/L with a significant growth of protozoa that may be connected to a concurrent algal growth inhibition.

Disinfection efficacy of chlorine and peracetic acid alone or in combination against Aspergillus spp. and Candida albicans in drinking water.

PubMed

Sisti, Maurizio; Brandi, Giorgio; De Santi, Mauro; Rinaldi, Laura; Schiavano, Giuditta F

2012-03-01

The aim of the present study was to evaluate the fungicidal activity of chlorine and peracetic acid in drinking water against various pathogenic Aspergillus spp. and Candida albicans strains. A. nidulans exhibited the greatest resistance, requiring 10 ppm of chlorine for 30 min contact time for a complete inactivation. Under the same experimental conditions, peracetic acid was even less fungicidal. In this case, A. niger proved to be the most resistant species (50 ppm for 60 min for complete inactivation). All Aspergillus spp. were insensitive to 10 ppm even with extended exposure (>5 h). The combination of chlorine and peracetic acid against Aspergillus spp. did not show synergistic effects except in the case of A. flavus. Complete growth inhibition of C. albicans was observed after about 3 h contact time with 0.2 ppm. C. albicans was less sensitive to peracetic acid. Hence the concentrations of chlorine that are usually present in drinking water distribution systems are ineffective against several Aspergillus spp. and peracetic acid cannot be considered an alternative to chlorine for disinfecting drinking water. The combination of the two biocides is not very effective in eliminating filamentous fungi at the concentrations permitted for drinking water disinfection.

Virulence Inhibitors from Brazilian Peppertree Block Quorum Sensing and Abate Dermonecrosis in Skin Infection Models

PubMed Central

Muhs, Amelia; Lyles, James T.; Parlet, Corey P.; Nelson, Kate; Kavanaugh, Jeffery S.; Horswill, Alexander R.; Quave, Cassandra L.

2017-01-01

Widespread antibiotic resistance is on the rise and current therapies are becoming increasingly limited in both scope and efficacy. Methicillin-resistant Staphylococcus aureus (MRSA) represents a major contributor to this trend. Quorum sensing controlled virulence factors include secreted toxins responsible for extensive damage to host tissues and evasion of the immune system response; they are major contributors to morbidity and mortality. Investigation of botanical folk medicines for wounds and infections led us to study Schinus terebinthifolia (Brazilian Peppertree) as a potential source of virulence inhibitors. Here, we report the inhibitory activity of a flavone rich extract “430D-F5” against all S. aureus accessory gene regulator (agr) alleles in the absence of growth inhibition. Evidence for this activity is supported by its agr-quenching activity (IC50 2–32 μg mL−1) in transcriptional reporters, direct protein outputs (α-hemolysin and δ-toxin), and an in vivo skin challenge model. Importantly, 430D-F5 was well tolerated by human keratinocytes in cell culture and mouse skin in vivo; it also demonstrated significant reduction in dermonecrosis following skin challenge with a virulent strain of MRSA. This study provides an explanation for the anti-infective activity of peppertree remedies and yields insight into the potential utility of non-biocide virulence inhibitors in treating skin infections. PMID:28186134

Mechanism of Sporicidal Activity for the Synergistic Combination of Peracetic Acid and Hydrogen Peroxide.

PubMed

Leggett, Mark J; Schwarz, J Spencer; Burke, Peter A; McDonnell, Gerald; Denyer, Stephen P; Maillard, Jean-Yves

2016-02-15

There is still great interest in controlling bacterial endospores. The use of chemical disinfectants and, notably, oxidizing agents to sterilize medical devices is increasing. With this in mind, hydrogen peroxide (H2O2) and peracetic acid (PAA) have been used in combination, but until now there has been no explanation for the observed increase in sporicidal activity. This study provides information on the mechanism of synergistic interaction of PAA and H2O2 against bacterial spores. We performed investigations of the efficacies of different combinations, including pretreatments with the two oxidizers, against wild-type spores and a range of spore mutants deficient in the spore coat or small acid-soluble spore proteins. The concentrations of the two biocides were also measured in the reaction vessels, enabling the assessment of any shift from H2O2 to PAA formation. This study confirmed the synergistic activity of the combination of H2O2 and PAA. However, we observed that the sporicidal activity of the combination is largely due to PAA and not H2O2. Furthermore, we observed that the synergistic combination was based on H2O2 compromising the spore coat, which was the main spore resistance factor, likely allowing better penetration of PAA and resulting in the increased sporicidal activity. Copyright © 2016 Leggett et al.

Mechanism of Sporicidal Activity for the Synergistic Combination of Peracetic Acid and Hydrogen Peroxide

PubMed Central

Leggett, Mark J.; Schwarz, J. Spencer; Burke, Peter A.; McDonnell, Gerald; Denyer, Stephen P.

2015-01-01

There is still great interest in controlling bacterial endospores. The use of chemical disinfectants and, notably, oxidizing agents to sterilize medical devices is increasing. With this in mind, hydrogen peroxide (H2O2) and peracetic acid (PAA) have been used in combination, but until now there has been no explanation for the observed increase in sporicidal activity. This study provides information on the mechanism of synergistic interaction of PAA and H2O2 against bacterial spores. We performed investigations of the efficacies of different combinations, including pretreatments with the two oxidizers, against wild-type spores and a range of spore mutants deficient in the spore coat or small acid-soluble spore proteins. The concentrations of the two biocides were also measured in the reaction vessels, enabling the assessment of any shift from H2O2 to PAA formation. This study confirmed the synergistic activity of the combination of H2O2 and PAA. However, we observed that the sporicidal activity of the combination is largely due to PAA and not H2O2. Furthermore, we observed that the synergistic combination was based on H2O2 compromising the spore coat, which was the main spore resistance factor, likely allowing better penetration of PAA and resulting in the increased sporicidal activity. PMID:26637595

Legionella spp. in Puerto Rico cooling towers

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

Negron-Alvira, A.; Perez-Suarez, I.; Hazen, T.C.

1988-10-01

Water samples from air conditioning cooling towers receiving different treatment protocols on five large municipal buildings in San Juan, P.R., were assayed for various Legionella spp. and serogroups by using direct immunofluorescence. Several water quality parameters were also measured for each sample. Guinea pigs were inoculated with water samples to confirm pathogenicity and recover viable organisms. Legionella pneumophila serogroups 1 to 6, L. bozemanii, L. micdadei, L. dumoffii, and L. gormanii were observed in at least one of the cooling towers. L. pneumophila was the most abundant species; its density reached 10{sup 5} cells per ml, which is within themore » range that is considered potentially pathogenic to humans. A significantly higher density of L. pneumophila was observed in the cooling tower water that was not being treated with biocides. Percent respiration (INT) and total cell activity (acridine orange direct count) were inversely correlated with bacterial density. This study demonstrates that Legionella spp. are present in tropical air-conditioning cooling systems and that, without continuous biocide treatment, they may reach densities that present a health risk.« less

Caenorhabditis elegans Predation on Bacillus anthracis: Decontamination of Spore Contaminated Soil with Germinants and Nematodes.

PubMed

Schelkle, Bettina; Choi, Young; Baillie, Leslie W; Richter, William; Buyuk, Fatih; Celik, Elif; Wendling, Morgan; Sahin, Mitat; Gallagher, Theresa

2017-01-01

Remediation of Bacillus anthracis -contaminated soil is challenging and approaches to reduce overall spore levels in environmentally contaminated soil or after intentional release of the infectious disease agent in a safe, low-cost manner are needed. B. anthracis spores are highly resistant to biocides, but once germinated they become susceptible to traditional biocides or potentially even natural predators such as nematodes in the soil environment. Here, we describe a two-step approach to reducing B. anthracis spore load in soil during laboratory trials, whereby germinants and Caenorhabditis elegans nematodes are applied concurrently. While the application of germinants reduced B. anthracis spore load by up to four logs depending on soil type, the addition of nematodes achieved a further log reduction in spore count. These laboratory based results suggest that the combined use of nematodes and germinants could represent a promising approach for the remediation of B. anthracis spore contaminated soil. Originality-Significance Statement: This study demonstrates for the first time the successful use of environmentally friendly decontamination methods to inactivate Bacillus anthracis spores in soil using natural predators of the bacterium, nematode worms.

Treatment of waste metalworking fluid by a hybrid ozone-biological process.

PubMed

Jagadevan, Sheeja; Graham, Nigel J; Thompson, Ian P

2013-01-15

In metal machining processes, the regulation of heat generation and lubrication at the contact point are achieved by application of a fluid referred to as metalworking fluid (MWF). MWFs inevitably become operationally exhausted with age and intensive use, which leads to compromised properties, thereby necessitating their safe disposal. Disposal of this waste through a biological route is an increasingly attractive option, since it is effective with relatively low energy demands. However, successful biological treatment is challenging since MWFs are chemically complex, and include biocides specifically to retard microbial deterioration whilst the fluids are operational. In this study remediation of the recalcitrant component of a semi-synthetic MWF by a novel hybrid ozone-bacteriological treatment, was investigated. The hybrid treatment proved to be effective and reduced the chemical oxygen demand by 72% (26.9% and 44.9% reduction after ozonation and biological oxidation respectively). Furthermore, a near-complete degradation of three non-biodegradable compounds (viz. benzotriazole, monoethanolamine, triethanolamine), commonly added as biocides and corrosion inhibitors in MWF formulations, under ozonation was observed. Copyright © 2012 Elsevier B.V. All rights reserved.

Virucidal properties of metal oxide nanoparticles and their halogen adducts.

PubMed

Häggström, Johanna; Balyozova, Denitza; Klabunde, Kenneth J; Marchin, George

2010-04-01

Selected metal oxide nanoparticles are capable of strongly adsorbing large amounts of halogens (Cl(2), Br, I(2)) and mixed halogens. These solid adducts are relatively stable thermally, and they can be stored for long periods. However, in the open environment, they are potent biocides. Herein are described studies with a number of bacteriophage MS2, phiX174, and PRD-1 (virus examples). PRD-1 is generally more resistant to chemical disinfection, but in this paper it is shown to be very susceptible to selected interhalogen and iodine adducts of CeO(2), Al(2)O(3), and TiO(2) nanoparticles. Overall, the halogen adducts of TiO(2) and Al(2)O(3) were most effective. The mechanism of disinfection by these nanoparticles is not completely clear, but could include abrasive properties, as well as oxidative powers. A hypothesis that nanoparticles damage virons or stick to them and prevent binding to the host cell is a consideration that needs to be explored. Herein are reported comparative biocidal activities of a series of adducts and electron microscope images of before and after treatment.

In Vitro Antifungal Activity of Burkholderia gladioli pv. agaricicola against Some Phytopathogenic Fungi

PubMed Central

Elshafie, Hazem S.; Camele, Ippolito; Racioppi, Rocco; Scrano, Laura; Iacobellis, Nicola S.; Bufo, Sabino A.

2012-01-01

The trend to search novel microbial natural biocides has recently been increasing in order to avoid the environmental pollution from use of synthetic pesticides. Among these novel natural biocides are the bioactive secondary metabolites of Burkholderia gladioli pv. agaricicola (Bga). The aim of this study is to determine antifungal activity of Bga strains against some phytopathogenic fungi. The fungicidal tests were carried out using cultures and cell-free culture filtrates against Botrytis cinerea, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, Sclerotinia sclerotiorum and Phytophthora cactorum. Results demonstrated that all tested strains exert antifungal activity against all studied fungi by producing diffusible metabolites which are correlated with their ability to produce extracellular hydrolytic enzymes. All strains significantly reduced the growth of studied fungi and the bacterial cells were more bioactive than bacterial filtrates. All tested Bulkholderia strains produced volatile organic compounds (VOCs), which inhibited the fungal growth and reduced the growth rate of Fusarium oxysporum and Rhizoctonia solani. GC/MS analysis of VOCs emitted by strain Bga 11096 indicated the presence of a compound that was identified as 1-methyl-4-(1-methylethenyl)-cyclohexene, a liquid hydrocarbon classified as cyclic terpene. This compound could be responsible for the antifungal activity, which is also in agreement with the work of other authors. PMID:23208371

Control of methicillin-resistant Staphylococcus aureus in planktonic form and biofilms: a biocidal efficacy study of nonthermal dielectric-barrier discharge plasma.

PubMed

Joshi, Suresh G; Paff, Michelle; Friedman, Gary; Fridman, Greg; Fridman, Alexander; Brooks, Ari D

2010-05-01

Bacterial contamination of surfaces with methicillin-resistant Staphylococcus aureus (MRSA) is a serious problem in the hospital environment and is responsible for significant nosocomial infections. The pathogenic contaminants form biofilms, which are difficult to treat with routine biocides. Thus, a continuous search for novel disinfection methods is essential for effective infection control measures. This demonstration of a novel technique for the control of virulent pathogens in planktonic form as well as in established biofilms may provide a progressive alternative to standard methodology. We evaluated a novel technique of normal atmospheric nonthermal plasma known as floating-electrode dielectric-barrier discharge (FE-DBD) plasma against a control of planktonic and biofilm forms of Escherichia coli, S aureus, multidrug-resistant methicillin-resistant S aureus (MRSA) -95 (clinical isolate), -USA300, and -USA400, using widely accepted techniques such as colony count assay, LIVE/DEAD BacLight Bacterial Viability assay, and XTT (2,3-Bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) assay. Exposure of free living planktonic forms of E coli, S aureus, and MRSA were rapidly inactivated by DBD plasma. Approximately 10(7) bacterial cells were completely (100%) killed, whereas 10(8) and 10(9) were reduced by approximately 90% to 95% and 40% to 45%, respectively, in less than 60 seconds (7.8 J/cm(2)) and completely disinfected in < or =120 seconds. In established biofilms, the susceptibility of MRSA USA400 was comparable with USA300 but less susceptible than MRSA95 (clinical isolate), S aureus, and E coli (P < .05) to FE-DBD plasma, and plasma was able to kill MRSA more than 60% within 15 seconds (1.95 J/cm(2)). The killing responses were plasma exposure-time dependent, and cell density dependent. The plasma was able disinfect surfaces in a less than 120 seconds. Application of DBD plasma can be a valuable decontamination technique for the removal of planktonic and biofilm-embedded bacteria such as MRSA -USA 300, -USA 400, methicillin-sensitive S aureus (MSSA), and E coli, the more common hospital contaminants. Of interest, E coli was more resistant than S aureus phenotypes. Copyright (c) 2010 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Marine Science Aids the Development of Antifouling Coatings,

DTIC Science & Technology

new toxic additives, tributyltin antifouling compounds and biocidal organometallic polymers. Future developments which may arise from fundamental biochemical research work on marine organisms are indicated. (Author)

Synthesis of ethylene maleic anhydride copolymer containing fungicides and evaluation of their effect for wood decay resistance

Treesearch

George C. Chen

2008-01-01

The aim of the present study was to combat wood decay based on the approach controlled-release biocides from polymers. The possibility of introducing polymer-bonded fungicides into the cell lumens was investigated. The synthesis of ethylene maleic anhydride copolymer containing pentachlorophenol (penta) and 8-hydroxy quinoline (8HQ) in N, N dimethyl formamide is...

Biotransformation of Tin.

DTIC Science & Technology

1981-05-26

of tributyltin moiety, Bu3Sn’ ( TBT ). rBT-resistant organisms from the Chesapeake. Bay were found to accumulate tributyltin . This accumulation did not...biotrans- formations of tributyltin moiety, Bu3Sn+ ( TBT ). TBT -resistant organisms chraz: from the Chesapeake Bay were found to accumulate tributyltin ...experiments (ref.l1). TRIBUTYLTIN DEGRADATION STUDIES As tribut,.ltin cation ( TBT ) is one of the most active biocidal agents extensively incorporated in

Reactivity of Dazomet, a Hydraulic Fracturing Additive: Hydrolysis and Interaction with Pyrite

NASA Astrophysics Data System (ADS)

Consolazio, N.; Lowry, G. V.; Karamalidis, A.; Hakala, A.

2015-12-01

The Marcellus Shale is currently the largest shale gas formation in play across the world. The low-permeability formation requires hydraulic fracturing to be produced. In this process, millions of gallons of water are blended with chemical additives and pumped into each well to fracture the reservoir rock. Although additives account for less than 2% of the fracking fluid mixture, they amount to hundreds of tons per frack job. The environmental properties of some of these additives have been studied, but their behavior under downhole conditions is not widely reported in the peer-reviewed literature. These compounds and their reaction products may return to the surface as produced or waste water. In the event of a spill or release, this water has the potential to contaminate surface soil and water. Of these additives, biocides may present a formidable challenge to water quality. Biocides are toxic compounds (by design), typically added to the Marcellus Shale to control bacteria in the well. An assessment of the most frequently used biocides indicated a need to study the chemical dazomet under reservoir conditions. The Marcellus Shale contains significant deposits of pyrite. This is a ubiquitous mineral within black shales that is known to react with organic compounds in both oxic and anoxic settings. Thus, the objective of our study was to determine the effect of pyrite on the hydrolysis of dazomet. Liquid chromatography-triple quadrupole mass spectrometry (LC-QQQ) was used to calculate the loss rate of aqueous dazomet. Gas chromatography-mass spectrometry (GC-MS) was used to identify the reaction products. Our experiments show that in water, dazomet rapidly hydrolyses in water to form organic and inorganic transformation products. This reaction rate was unaffected when performed under anoxic conditions. However, with pyrite we found an appreciable increase in the removal rate of dazomet. This was accompanied by a corresponding change in the distribution of observed reaction products. Our results indicate the need to determine specific mineral-additive interactions to evaluate the potential risks of chemical use in hydraulic fracturing.

Development and application of a microwave-assisted extraction and LC/MS/MS methodology to the determination of antifouling booster biocides in sea mullets (Mugil cephalus) organisms.

PubMed

Franco-Barrios, Alejandro; Torres-Padrón, María Esther; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José Juan

2014-01-01

A method is presented for the extraction, preconcentration, and determination of two commonly used booster biocides, Irgarol 1051 and diuron, in samples of muscle and liver tissues from Mugil cephalus by microwave-assisted extraction (MAE) followed by SPE for the preconcentration and cleanup step, coupled with LC/MS/MS. The optimum conditions for MAE were established as power 200 W and irradiation time 4 min. Using these conditions, the LOD was 0.13 ng/g for diuron and 0.10 ng/g for Irgarol 1051. The recoveries calculated at three concentration levels (0.5, 5, and 50 ng/g) were greater than 74%. Repeatability was less than 7.5% and reproducibility less than 12.7%. The optimized method was used to monitor these compounds in M. cephalus from different harbors of Gran Canaria Island. The samples were collected bimonthly and processed following the optimized method. High levels of Irgarol 1051 (6.9 +/- 1.03 ng/g) were found in the liver, while diuron was undetected. However, diuron was found in the muscle (1.41 +/- 0.45 ng/g). The proposed sentinel organism could be used in tropical and subtropical regions to continuously biomonitor for booster biocides over long periods of time. This technique could be a useful tool for improving the management of ocean and coastal waters.

A survey of antifoulants in sediments from Ports and Marinas along the French Mediterranean coast.

PubMed

Cassi, Roberto; Tolosa, Imma; de Mora, Stephen

2008-11-01

Due to deleterious effects on non-target organisms, the use of organotin compounds on boat hulls of small vessels (<25 m) has been widely prohibited. The International Maritime Organisation (IMO) resolved that the complete prohibition on organotin compounds acting as biocides in antifouling systems should commence in 2008. As a result of restrictions on the use of organotin based paints, other antifouling formulations containing organic biocides have been utilised. This survey was conducted to assess the contamination of replacement biocides in the marine environment following the ban of TBT-based paints. Surface sediments samples were collected in the major ports and marinas along the France Mediterranean coastline (Cote d'Azur) and analysed for organotin compounds, Irgarol 1051, Sea-nine 211, Chlorothalonil, Dichlofluanid and Folpet. Every port and marina exhibited high levels of organotin compounds, with concentrations in sediments ranging from 37 ng Sn g(-1) dry wt in Menton Garavan to over 4000 ng Sn g(-1) dry wt close to the ship chandler within the port of Villefranche-sur-Mer. TBT degradation indexes suggested that fresh inputs are still made. Among the other antifoulants monitored, only Irgarol 1051 exhibited measurable concentrations in almost every port, with concentrations ranging from 40 ng g(-1) dry wt (Cannes) to almost 700 ng g(-1) dry wt (Villefranche-sur-Mer, ship chandler).

A simple and rapid method for optical visualization and quantification of bacteria on textiles

PubMed Central

Stiefel, Philipp; Schneider, Jana; Amberg, Caroline; Maniura-Weber, Katharina; Ren, Qun

2016-01-01

To prevent bacterial contamination on textiles and the associated undesired effects different biocidal coatings have been investigated and applied. However, due to health and environmental concerns anti-adhesive coatings preventing the binding of bacteria would be favored. To develop such anti-adhesive coatings simple assays for reliable and fast screening are beneficial. Here an easy-to-handle, robust and rapid assay to assess bacteria on textiles utilizing a tetrazolium salt was reported. The assay allowed direct eye visualization of the color change of the textiles containing bacteria, facilitating fast screening. Quantification of the adhered bacteria could be done by generating standard curves which correlate the staining intensity to cell numbers. An additional advantage of the described assay is that with the same detection method anti-adhesive and biocidal effects can be investigated. The method was applied to different coatings, using Pseudomonas aeruginosa and Staphylococcus aureus as model organisms. The detection limit was found to be between 2.5 * 106 and 9.4 * 108 for P. aeruginosa and between 1 * 106 and 3.3 * 108 for S. aureus. The anti-adhesive coating PLUMA was demonstrated to reduce bacterial adhesion without killing them, whereas the biocidal coating TH22-27 caused a clear reduction in the number of viable cells. PMID:28004762