Academic literature on the topic 'Disinfectant Concentration'

Disinfectants are regularly used for cleansing poultry slaughterhouses to control microorganisms. However, the microorganisms such as bacteria are developing resistance to disinfectant(s) and complicate control of bacterial infections. The aim of this study was, therefore, to determine disinfectant susceptibility/resistance patterns manifested by bacteria (to commonly used disinfectants), which were isolated from intestines of slaughtered indigenous chickens in Nairobi, Kenya. The method used was agar well diffusion, and the six disinfectants (their active ingredients are in brackets) tested were as follows: Kupacide® (glutaraldehyde; benzalkonium chloride); TH4+® (didecyl dimethyl ammonium HCl; dioctyl dimethyl ammonium HCl; octyl decyldimethyl ammonium HCl; alkyl dimethyl ammonium HCl; and glutaraldehyde); Noro cleanse® (glutaraldehyde; coco-benzyl-dimethyl-ammonium chloride); Dettol® (chloroxylenol); Savlon® (chlorhexidine gluconate; cetrimide; and N-propylalcohol); and Jik® (sodium hypochlorite). At recommended user concentration by the manufacturer, isolates showed various resistance to the respective disinfectants. E. coli isolates were resistant to five of the tested disinfectants (Jik®, TH4+®, Noro cleanse®, Dettol®, and Kupacide®); however, they were susceptible to Savlon®; Staphylococcus isolates were resistant to disinfectants to Jik® and TH4+® and susceptible to the rest disinfectants; Streptococcus isolates were only resistant to Jik® and susceptible to the remaining disinfectants. Some E. coli and Staphylococcus isolates showed resistance to more than one disinfectant. This study has demonstrated resistance of the bacterial isolates to various disinfectants at recommended user concentrations, although some of them were susceptible at higher concentration(s) and lower concentrations. This will interfere with the cleansing of the respective premises, resulting in contaminated products, which may end-up causing disease in the humans consuming them. Hence, it is recommended that one ascertains the efficacy of respective disinfectant by carrying out disinfectant susceptibility testing to know the effective ones and the appropriate concentration to use.

Six commercial disinfectants were tested for their efficacy in inactivating hepatitis A virus in solution or attached to agri-food surfaces. Disinfectant I contains 10% quaternary ammonium plus 5% glutaraldehyde;disinfectant II contains 12% sodium hypochlorite; disinfectant III contains 2.9% dodecylbenzene sulfonic acid plus 16% phosphoric acid; disinfectant IV contains 10% quaternary ammonium; disinfectant V contains 2% iodide; and disinfectant VI contains 2% stabilized chlorine dioxide. Among these, disinfectants I and II were shown to be the most effective in inactivating hepatitis A virus in solution. The efficacy of these disinfectants was further tested against hepatitis A virus attached to common agri-food surfaces, including polyvinyl chlorine, high-density polyethylene, aluminum, stainless steel, and copper. Disinfectant II was shown to be the most effective, with a maximum inactivation level of about 3 log10. The inactivation efficacy was shown to be affected by the concentration of the active ingredient, the contact time between the disinfectant and the contaminated surfaces, and the incubation temperature. In general, hepatitis A virus was shown to be highly resistant to most disinfectants tested, and high concentrations of active ingredient were needed to achieve acceptable inactivation levels.

Background: The prevalence of disinfectant resistance in Pseudomonas aeruginosa is on the rise. P. aeruginosa is the most common bacteria isolated from cases of microbial keratitis. Many multi-purpose contact lens disinfectant solutions are available to decontaminate contact lenses before use and to help reduce the incidence of infections. However, with increasing disinfectant resistance, the effect of multi-purpose disinfectant solutions may diminish. The goal of this study was to examine genes associated with disinfectant resistance in ocular isolates of P. aeruginosa and understand the strain’s susceptibility to different multipurpose disinfectant solutions. Methods: Seven potential disinfectant resistance genes were used in BLASTn searches against the whole genomes of 13 eye isolates of P. aeruginosa. A microdilution broth method was used to examine susceptibility to four different multipurpose disinfectant solutions. Results: All strains possessed the sugE2, sugE3 and emrE (qacE) genes. The sugE1 and qacEdelta1 genes were present in 6/13 isolates. No strains contained the qacF or qacG genes. All tested disinfectant solutions had the ability to kill all test strains at 100% concentration, with some strains being susceptible at 1:8 dilutions of the disinfecting solutions. However, the presence of disinfectant resistance genes was not associated with susceptibility to multi-purpose disinfectants. Conclusion: All four tested contact lens disinfectant preparations are effective against P. aeruginosa isolates regardless of the presence of disinfectant resistance genes.

Point-of-use (POU) gravity-driven household water purifiers have been proven to be a simple, low-cost and effective intervention for reducing the impact of waterborne diseases in developing countries. The goal of this study was to compare commonly used water disinfectants for their feasibility of adoption in low-cost POU water purifiers. The potency of each candidate disinfectant was evaluated by conducting a batch disinfection study for estimating the concentration of disinfectant needed to inactivate a given concentration of the bacterial strain Escherichia coli ATCC 11229. Based on the concentration of disinfectant required, the size, weight and cost of a model purifier employing that disinfectant were estimated. Model purifiers based on different disinfectants were compared and disinfectants which resulted in the most safe, compact and inexpensive purifiers were identified. Purifiers based on bromine, tincture iodine, calcium hypochlorite and sodium dichloroisocyanurate were found to be most efficient, cost effective and compact with replacement parts costing US$3.60–6.00 for every 3,000 L of water purified and are thus expected to present the most attractive value proposition to end users.

The germicidal efficacy of four common disinfectants used for different purposes was tested against two common pathogens namely Escherichia coli and Staphylococcus aureus . The disinfectants (Dettol, Jik, Izal and Purit) were diluted with sterile distilled water to achieve different concentrations (100%, 50%, 25%, 12.5% and 6.25%) and they were tested on the two organisms using Agar well diffusion method. The plates were allowed to incubate for 24 hours at 37°C.The germicidal efficiency of the disinfectants was evaluated by measuring the zone of inhibition of each disinfectant based on their varying concentrations. Dettol was observed to have the highest inhibition at 100% concentration and was more germicidal on E. coli than S. aureus with Minimal Inhibitory Concentration (MIC) value of 1:16 dilution against the two test organisms. This was closely followed by Jik which also showed more inhibitory activity against E. coli at the initial concentration recording the second highest inhibition rate compared to other disinfectants, but its efficacy decreased as the concentration dropped. Jik exhibited MIC value of 1:8 and 1:2 dilutions for Staphylococcus aureus and Escherichia coli respectively. Purit showed more inhibitory activity on S. aureus with 3.8mm zone of inhibition as against 1.3mm at 100% concentration, recording MIC value of 1:8 dilution on S. aureus and 1:16 dilution for E. coli . The disinfectant Izal was observed to be the lowest as it did not inhibit the growth of any of the organisms, indicating resistance of the organisms to the disinfectant at all concentrations. All the disinfectants apart from Izal inhibited the two test isolates. Only Dettol proved to be best among them. Therefore, Dettol is encouraged to be used in homes to prevent pathogenic infection.

The effectiveness of the process of photoactivation of aqueous solutions has been proven by studies conducted in the article. As a method of exposure, UV radiation is low-cost and natural, so there is a need to study the effect of ultraviolet radiation on aqueous disinfectant solutions and to determine effective methods of irradiation. Accordingly, there is a need to investigate the effect of UV radiation on disinfectants, in particular on their antimicrobial properties and to determine the effective effect of ultraviolet radiation on the tool. The high pressure mercury arc lamp DRT-400 lamp was used as a source of ultraviolet radiation. The surface of the aqueous solution was at a distance of 0.25 m under a source of UV radiation. The photoactivated liquid was applied to the agar medium immediately after inoculation of bacteria. The growth of colonies of microorganisms was recorded 24 hours after application of the treated disinfectant solution. At the Department of Electrical Engineering, Electromechanics and Electrical Technologies of NULES of Ukraine measurements of pH, redox potential of disinfectant solutions immediately after irradiation were carried out. Graphical dependences of changes of disinfecting properties are received. It is established that ultraviolet radiation significantly changes the pH and redox potential of aqueous solutions of disinfectants. The intensity of the parameter change is characteristic of ultraviolet radiation at an exposure of 5-15 minutes. Irradiation of сoncentrated disinfectant based on quaternary ammonium and glutaraldehyde «Keno Cid 210» solution for 5 minutes effectively inhibits the growth properties of microorganisms. The concentration of the irradiated aqueous disinfectant solution can be 5 times lower than the concentration of the non-irradiated.

The results of research bactericidal properties of new domestic disinfectant «Alkisept–100» that based on a glutaraldehyde, didecyldimethylammonium chloride, alkyldimethylbenzylammonium chloride and aminotrismethylenephosphonic acid. Was found bactericidal dilution (BD), bactericidal concentration (BC), phenol coefficient (FC) and protein index (PI). Most susceptible to the effect of disinfectant was test-cultures of P. vulgaris, where cell death came on the 10 and 30 minutes exposures at concentrations of 0.26 and 0.18%, respectively. The action of disinfection preparation for gram-positive bacteria S. aureus, vegetative cells of B. subtilis vegetative cells and cultures of S. typhimurium test-cell death drew under these conditions at concentrations of 0.72 and 0.52%, respectively. Gram-negative bacteria E. coli were more susceptible to disinfectant and cell death drew for these exposures at concentrations of 0.52 and 0.37 %, respectively. BD of this disinfectat were 1.96 and 1.4 higher times for E. coli and S. aureus, respectively, from BD phenol, and in the presence of protein activity investigated disinfection preparation is reduced to 2.74 times. The efficacy of disinfection preparation of microorganisms on surfaces in the decontamination of test objects. It is established that test cultures of E. coli and S. aureus (without organic impurities) at 0.1% concentration of disinfectant is ineffective. For spore form of B. subtilis disinfection preparation concentration at 4.0%. Is ineffective At the 1.0–1.5% and higher concentrations is effective for surface treatment of wood, metal and tile that are contaminated with organic substances and objects subject to veterinary controls, and for elimination spore forms of microorganisms at its working concentration of desinfectant should be 5.0% or higher, the exposure in 120 minutes or more. Proved that the disinfectant «Alkisept–100» in a production environment at a concentration of 1.0% by wet surface irrigation facilities for animals and working solution 0.25–0.3 liters per 1 square meter with an exposure of 2 hours, showing high disinfectant properties.

The first and the main link in the system of prevention of the occurrence and distribution of avian influenza and Newcastle disease is monitoring and the effective prophylaxis of the above diseases. At the same time the conducting of disinfection of the objects of veterinary control is an important stage in the system of veterinary and sanitary measures. A number of disinfectants that contain different classes of chemical compounds as active substances have been developed and proposed for practical use. The large-scale production of disinfectants and their introduction into practice is impossible without the preliminary laboratory assessment of their antimicrobial properties, the determination of the spectrum of their biocidal effect and physical, chemical and toxicological properties. The aim of our work was to study the virucidal properties of a new aldehyde disinfectant using the test models of the viruses of Newcastle disease and avian influenza. The experiments to study virucidal properties of the disinfectant regarding the viruses of avian influenza and Newcastle disease have been carried out at the Department for Avian Diseases Study of the National Scientific Center ‘Institute of Experimental and Clinical Veterinary Medicine’ in accordance with the guidelines ‘Methods for determining and evaluating the safety and quality of disinfectants and disinfecting detergents used in the production, storage, transportation and sale of products of animal origin’ (Kotsiumbas et al., 2010). The determination of the virucidal properties of the disinfectant has been conducted in two stages: stage 1 — the determination of the virucidal activity of the product by the suspension method; stage 2 — determination of the virucidal activity of the product on test objects. As a result of the research conducted by the suspension method the presence of the virucidal properties of the innovative disinfectant (the mixture of quaternary ammonium compounds — 25%, glutar aldehyde — 11%, isopropanol, non-ionic surfactants) for the viruses of avian influenza and Newcastle disease has been determined. It has been found that the above preparation completely inactivated the infective properties of viruses when used in the concentration of 0.1%, with the interval of 30 minutes and in the concentration of 0.5% — 15-minute interval. It has been proved that the use of the disinfectant in 0.1% concentration for 30 minutes disinfected the test objects (wood, metal, tile, textile) that were contaminated by the pathogenic agents of avian influenza and Newcastle disease

Due to the absence of elaborated effi cient means for specifi c prevention of bovine tuberculosis, it is ex- tremely important to detect and eliminate the source of infection and to take veterinary and sanitary preven- tive measures. Here the critical role is attributed to disinfection, which breaks the epizootic chain due to the elimination of pathogenic microorganisms in the environment and involves the application of disinfectants of different chemical groups. Aim. To study the tuberculocidal properties of new disinfectants DZPT-2 and FAG against atypical mycobacteria Mycobacterium fortitum and a TB agent Mycobacterium bovis. Methods. The bacteriological and molecular-genetic methods were used. Results. It was determined that DZPT-2 prepara- tion has bactericidal effect on M. fortuitum when used in the concentration of 2.0 % of the active ingredient (AI) when exposed for 5–24 h, while disinfectant FAG has a bactericidal effect in the concentration of 2.0 % when exposed for 24 h. Disinfectant DZPT-2 in the concentration of 2.0 % of the AI, when exposed for 5–24 h, and FAG preparation in the concentration of 2.0 %, when exposed for 24 h, and with the norm of consump- tion rate of 1 cubic decimeter per 1 square meter disinfect the test-objects (batiste, wood, glazed tile, metal, glass), contaminated with the TB agent M. bovis. Conclusions. Disinfecting preparations of DZPT-2 in the concentration of 2.0 % of AI when exposed for 5 h and FAG in the concentration of 2.0 % when exposed for 24 h may be used in the complex of veterinary and sanitary measures to prevent and control TB of farm ani- mals. The possibility of using the polymerase chain reaction as an additional method of estimating tuberculo- cide activity of disinfectants was proven.

Introduction. Effective sanitation strategies for poultry farms require an appropriate selection of the disinfectant based on the contaminants present and their sensitivity to the disinfectants. Aim. The current study investigated the prevalence of streptococci/micrococci in poultry farms of Bangladesh and the efficacy of commercial disinfectants (Savlon, Lysol, Quatovet, Virkon S, and Virocid) along with alcohol against these pathogens to adopt appropriate strategies. Materials and Methods. Conventional approaches and the 16S rRNA gene sequencing were performed to confirm the isolates at the species level along with microtiter biofilm assay to determine their biofilm-forming ability. Efficacy of the disinfectants was tested against those isolates using agar well diffusion and minimum inhibitory concentration (MIC) test by broth dilution method using different dilutions of the disinfectants. Results. Staphylococcus lentus (n = 32), Micrococcus luteus (n = 7), and Micrococcus aloeverae (n = 4) were confirmed among 102 presumptively screened streptococci/micrococci isolates from 43 samples. No single disinfectant showed equally high efficacy against all three bacterial species in agar well diffusion test, although Virocid showed the lowest MIC against all three of them. Lysol was least effective among the commercial disinfectants by both MIC and diffusion method, although each commercial disinfectant was more effective than alcohol. Considering both the average diameter of the inhibition zones and the MIC values, efficacy can be interpreted as Virocid > Quatovet > Savlon > Virkon S > Lysol. Although the efficacy decreased with decreasing concentration, the disinfectants retained a satisfactory level of efficacy at 50% concentration. Among test pathogens, M. aloeverae was the most sensitive to the disinfectants and the weakest biofilm producers, whereas 4/14 S. lentus and 1/5 M. luteus were strong biofilm producers, which may cause more reduction in the efficacy in environmental conditions. Conclusion. As no ideal disinfectant was found in the study, the efficacy of the disinfectants should be routinely evaluated and validated to ensure the sanitation standards in the poultry sector.

Disinfection of the municipal water systems is mostly achieved by means of chlorine addition at water treatment plants known as sources. Thus, there should be an adequate chlorine concentration at the source for an effective disinfection throughout the system by considering upper and lower limits of disinfectant. However, since the disinfectants are reactive and decays through the system, chlorine added at the source may not be enough to maintain desired disinfectant residuals which may lead to water quality problems in the water distribution system. Moreover, the disinfectants such as chlorine has also an effect to be carcinogen due to formation of disinfectant by-products. Thus, the system should balance the amount of disinfectant supplied while minimizing the health risk. In such a case, it is recommended that one or more booster disinfection stations can be located throughout the system. Such a method can provide more uniform distribution of the chlorine concentration while reducing the amount of the disinfectant used. In this thesis, optimum scheduling, and injection rates of the booster disinfection stations have been searched. The objective is to minimize the injected mass dosage rate subjected to the provision of adequate and more uniform residual concentration in the network. Determination of variable network hydraulics and chlorine concentrations is held out by EPANET network simulation sofware. A C++ code was developed to interface with EPANET by means of the EPANET Programmer&#039<br>s Toolkit for linear optimization of the disinfectant mass dosage rate applied to the network.

Einführung: Enterobacter (E.) cloacae subsp. cloacae sind wichtige Humanpathogene, insbesondere bei stationär untergebrachten Patienten. Sie sind in der Lage, Medizinprodukte zu kontaminieren, und es wurde über nosokomiale Krankheitsausbrüche in Verbindung mit der Kolonisation von chirurgischen Utensilien berichtet. Es ist daher wichtig, die Wirksamkeit und Effizienz von Desinfektionsmitteln gegenüber dieser Bakterienart zu bestimmen. Ziele: Die aktuelle Studie wurde durchgeführt, um nachzuweisen, ob Peressigsäure, Ethanol, Benzalkoniumchlorid und Natriumhypochlorit, welche weit verbreitet in kommerziellen Desinfektionsmitteln enthalten sind, eine ausreichende Wirksamkeit gegen multiresistente, von Patienten im Krankenhaus isolierte, E. cloacae aufweisen. Material und Methoden: Sechs multiresistente E. cloacae Isolate, die von Patienten in einem klinischen Umfeld gewonnen wurden, wurden getestet und mit dem E. cloacae Typstamm verglichen. Die Studien wurden in vitro mit Peressigsäure, Ethanol, Benzalkoniumchlorid und Natriumhypochlorit nach den Richtlinien der Desinfektionsmittel-Kommission des Verbundes für Angewandte Hygiene e.V. durchgeführt. Die Tests umfassten qualitative und quantitative Suspensionstests zur Bestimmung der bakteriziden Wirkung, den sogenannten Keimträgertest und die Bestimmung der minimalen Hemmkonzentrationen. Ergebnisse: Die Studienergebnisse zeigten, dass multiresistente E. cloacae Stämme genauso empfindlich gegenüber Desinfektionsmitteln waren wie der Typstamm. Organische Belastung interagierte stark mit Natriumhypochlorit und minderte dadurch seine Wirksamkeit, während Peressigsäure und Ethanol nicht durch organische Verunreinigung beeinflusst wurden. Die Kontaktzeit hatte nur einen geringen Einfluss auf die bakterizide Wirkung. Im Gegensatz dazu spielten bei Benzalkoniumchlorid organische Verunreinigung und die Kontaktzeit eine wichtige Rolle. Insgesamt waren die minimalen Hemmkonzentrationen und die bakterizid wirksamen Konzentrationen niedriger als die für kommerzielle Produkte gebräuchlichen Konzentrationen. In den Keimträgertests hatte das Trocknen auf einer glatten Oberfläche einen Einfluss auf das Überleben eines Stammes von E. cloacae. Die Ergebnisse zeigten auch, dass sich die Wirksamkeit der Desinfektionsmittel in den verschiedenen verwendeten Tests deutlich unterscheiden kann. Die Ergebnisse waren schwer mit anderen Studien zu vergleichen, da eine internationale Durchführungsrichtlinie für die Prüfung der Wirksamkeit von Desinfektionsmitteln gegen multiresistente Bakterien fehlt. Fazit: Peressigsäure, Ethanol, Benzalkoniumchlorid und Natriumhypochlorit eignen sich zur Desinfektion von multiresistenten E. cloacae. Die Wirksamkeit von Natriumhypochlorit und Benzalkoniumchlorid wird jedoch stark durch organische Stoffe beeinflusst. Dies unterstreicht die Bedeutung geeigneter Reinigungsmaßnahmen vor der Desinfektion. Wenn dies erfolgt ist, erweisen sich die getesteten Desinfektionsmittel gegen multiresistente E. cloacae genauso effektiv wie gegen den Typstamm.:1. Introduction ............................................................ 1 2. Literature Review ....................................................... 3 2.1 Enterobacteriaceae ..................................................... 4 2.1.1 General properties ................................................... 4 2.1.2 Enterobacter cloacae complex ......................................... 4 2.2 Multidrug-resistant bacteria and disinfectant “resistance” ............. 6 2.3 Disinfectant testing ................................................... 7 2.4 Active substances investigated in this study ........................... 8 2.4.1 Peracetic acid (PAA) ................................................. 8 2.4.2 Ethanol (ETH) ........................................................ 9 2.4.3 Benzalkonium chloride (BKC) .......................................... 9 2.4.4 Sodium hypochlorite (NaOCl) .......................................... 10 3. Materials and Methods ................................................... 11 3.1 Materials .............................................................. 11 3.2 Methods ................................................................ 14 3.2.1 Culture and storage of bacteria ...................................... 14 3.2.2 Preparation of disinfectants and the neutralizing agent .............. 14 3.2.3 Minimum inhibitory concentration (MIC) ............................... 15 3.2.4 Qualitative suspension test .......................................... 15 3.2.5 Quantitative suspension test.......................................... 16 3.2.6 Surface disinfection without mechanical action (germ carrier test) ... 16 3.2.7 Statistical analysis ................................................. 17 4. Results ................................................................. 18 4.1 Minimum inhibitory concentrations ...................................... 18 4.2 Qualitative suspension tests ........................................... 18 4.3 Quantitative suspension tests .......................................... 21 4.4 Surface disinfection without mechanical action (germ carrier test) ..... 24 5. Discussion .............................................................. 28 6. Summary ................................................................. 31 7. Zusammenfassung ......................................................... 33 8. References .............................................................. 35 9. Appendix ................................................................ 49 Acknowledgments ............................................................ 50<br>Introduction: Enterobacter (E.) cloacae subsp. cloacae are important human pathogens, particularly in hospitalized patients. They tend to contaminate various medical devices and nosocomial outbreaks have been reported to be associated with the colonization of surgical equipment. Therefore, it is critical to determine the efficacy and effectiveness of disinfectants against this bacterial species. Objectives: The current study was undertaken to prove whether single active ingredients (i.e. peracetic acid, ethanol, benzalkonium chloride, and sodium hypochlorite) of widely used commercial disinfectants provide proper efficacy against multidrug-resistant human isolates of E. cloacae. Material and Methods: Six multidrug-resistant E. cloacae isolates obtained from patients in a clinical setting were tested and compared to the E. cloacae type strain. The studies were performed in vitro using peracetic acid, ethanol, benzalkonium chloride and sodium hypochlorite following the guidelines specified by the Disinfectants Commission within the Association of Applied Hygiene. Tests included determination of minimum inhibitory concentrations, bactericidal values by qualitative and quantitative suspension tests, and so-called germ carrier tests. The influence of exposure time and organic load on bacteriostatic and bactericidal concentrations was evaluated for each disinfectant using the two-tailed Mann-Whitney U-test. Results: Study results showed that multidrug-resistant E. cloacae strains were equally susceptible to disinfectants as the type strain. Organic matter highly interfered with sodium hypochlorite thereby decreasing its efficacy whereas peracetic acid and ethanol were not influenced by organic soiling. Contact time had only a minor effect on bactericidal values. This was in contrast to benzalkonium chloride where organic soiling and contact time played an important role. On the whole, minimum inhibitory concentrations and bactericidal concentrations were lower than in-use concentrations of commercial products. Drying on smooth surfaces in the carrier tests had an effect on the survival of one E. cloacae strain. Results also showed that efficacious values determined by the different tests used may differ distinctly. Results were difficult to compare with other studies because an international practical standard for testing disinfectant efficacy against multidrug-resistant bacteria is missing. Conclusion: Peracetic acid, ethanol, benzalkonium chloride and sodium hypochlorite are suitable to disinfect multidrug-resistant E. cloacae but the effectiveness of sodium hypochlorite and benzalkonium chloride is strongly influenced by organic matter. This underlines the importance of proper cleaning measures before disinfection. When this is done, the tested disinfectants proved to be as efficient against multidrug-resistant E. cloacae as against the type strain.:1. Introduction ............................................................ 1 2. Literature Review ....................................................... 3 2.1 Enterobacteriaceae ..................................................... 4 2.1.1 General properties ................................................... 4 2.1.2 Enterobacter cloacae complex ......................................... 4 2.2 Multidrug-resistant bacteria and disinfectant “resistance” ............. 6 2.3 Disinfectant testing ................................................... 7 2.4 Active substances investigated in this study ........................... 8 2.4.1 Peracetic acid (PAA) ................................................. 8 2.4.2 Ethanol (ETH) ........................................................ 9 2.4.3 Benzalkonium chloride (BKC) .......................................... 9 2.4.4 Sodium hypochlorite (NaOCl) .......................................... 10 3. Materials and Methods ................................................... 11 3.1 Materials .............................................................. 11 3.2 Methods ................................................................ 14 3.2.1 Culture and storage of bacteria ...................................... 14 3.2.2 Preparation of disinfectants and the neutralizing agent .............. 14 3.2.3 Minimum inhibitory concentration (MIC) ............................... 15 3.2.4 Qualitative suspension test .......................................... 15 3.2.5 Quantitative suspension test.......................................... 16 3.2.6 Surface disinfection without mechanical action (germ carrier test) ... 16 3.2.7 Statistical analysis ................................................. 17 4. Results ................................................................. 18 4.1 Minimum inhibitory concentrations ...................................... 18 4.2 Qualitative suspension tests ........................................... 18 4.3 Quantitative suspension tests .......................................... 21 4.4 Surface disinfection without mechanical action (germ carrier test) ..... 24 5. Discussion .............................................................. 28 6. Summary ................................................................. 31 7. Zusammenfassung ......................................................... 33 8. References .............................................................. 35 9. Appendix ................................................................ 49 Acknowledgments ............................................................ 50

When contagious diseases occur, there is a tangible threat of rampant spread of infection, incurring huge economic losses in animal deaths and decreased animal productivity. Thus, preventing pathogenic flora concentration in rooms where birds and animals are raised from exceeding permissible levels ranks first among veterinarian and sanitary concerns. When birds are kept on the floor during feeding, germ and dust concentration increases nine to ten times against normal. Ample research shows that ultraviolet (UV) radiation possessing a bactericidal effect is the most promising and environmentally friendly method of cleansing the air from harmful germs.

&lt;em&gt;Abstract.&lt;/em&gt;—A water filtration and ozone disinfection system was installed at the U.S. Fish and Wildlife Service’s Northeast Fishery Center in Lamar, Pennsylvania to treat a surface water supply that is used to culture sensitive and endangered fish. The treatment system first passes the surface water through drum filters operated with 60-m sieve panels in order to exclude the majority of debris, algae, and organisms larger than the sieve openings. After microscreen filtration, two variable speed pumps are operated in parallel to supply between 400 and 2,400 µmin to the ozone treatment system. Ozone contained within an approximately 95% oxygen feed gas is transferred in to the water (at 0.5–0.7 bar) through a downflow bubble contactor following each pump. The ozonated water is then collected and piped to a 15.1-m3 ozone contact column. The contact column provides approximately 20, 10, or 6.7 min of plug-flow contact time for water flows of 760, 1,500, or 2,270 L/min, respectively. A dissolved ozone probe at the outlet of the ozone contact chamber continuously monitors the dissolved ozone concentration discharged from the contact tank. A proportional- integral-derivative feedback control loop is used to adjust the concentration of ozone generated (and thus added) in order to maintain the dissolved ozone residual discharged from the ozone disinfecting contact tank at a preselected set point (nominally 0.2 mg/L). The water discharged from the ozone disinfecting contact tank then flows by gravity through a second 32.1-m3 contact tank, which provides additional time for the dissolved ozone to decompose. Any dissolved ozone remaining in the water exiting the second contact vessel is air-stripped, along with any large dissolved oxygen supersaturation, as the water flows by gravity through a forced-ventilated cascade column. This treated water then flows by gravity to the fish culture systems. The ozone system was evaluated during a start-up period from March through June of 2002. During this period, the ozonation and filtration system was found to consistently inactivate bacteria and exclude the majority of debris larger than the microscreen openings, even during extreme changes in surface water quality produced by storm events. Design and performance details are provided to offer insight into the strengths and weaknesses of the individual treatment processes.

&lt;em&gt;Abstract.&lt;/em&gt;—A water filtration and ozone disinfection system was installed at the U.S. Fish and Wildlife Service’s Northeast Fishery Center in Lamar, Pennsylvania to treat a surface water supply that is used to culture sensitive and endangered fish. The treatment system first passes the surface water through drum filters operated with 60-m sieve panels in order to exclude the majority of debris, algae, and organisms larger than the sieve openings. After microscreen filtration, two variable speed pumps are operated in parallel to supply between 400 and 2,400 µmin to the ozone treatment system. Ozone contained within an approximately 95% oxygen feed gas is transferred in to the water (at 0.5–0.7 bar) through a downflow bubble contactor following each pump. The ozonated water is then collected and piped to a 15.1-m3 ozone contact column. The contact column provides approximately 20, 10, or 6.7 min of plug-flow contact time for water flows of 760, 1,500, or 2,270 L/min, respectively. A dissolved ozone probe at the outlet of the ozone contact chamber continuously monitors the dissolved ozone concentration discharged from the contact tank. A proportional- integral-derivative feedback control loop is used to adjust the concentration of ozone generated (and thus added) in order to maintain the dissolved ozone residual discharged from the ozone disinfecting contact tank at a preselected set point (nominally 0.2 mg/L). The water discharged from the ozone disinfecting contact tank then flows by gravity through a second 32.1-m3 contact tank, which provides additional time for the dissolved ozone to decompose. Any dissolved ozone remaining in the water exiting the second contact vessel is air-stripped, along with any large dissolved oxygen supersaturation, as the water flows by gravity through a forced-ventilated cascade column. This treated water then flows by gravity to the fish culture systems. The ozone system was evaluated during a start-up period from March through June of 2002. During this period, the ozonation and filtration system was found to consistently inactivate bacteria and exclude the majority of debris larger than the microscreen openings, even during extreme changes in surface water quality produced by storm events. Design and performance details are provided to offer insight into the strengths and weaknesses of the individual treatment processes.

This paper presents a study of traditional netting materials subjected to disinfecting chemicals during fish farming and treatment of net cages. A series of tests were performed in order to study the effect of various concentrations of disinfecting chemicals on the tensile strength of Raschel knitted Nylon netting materials. Simulated spill of diluted hydrogen peroxide to the jump fence during de-lousing did not affect the strength of the applied new and used knotless nylon netting samples. Hydrogen peroxide reacted with biofouling forming gas bubbles, but this did not result in reduced netting strength. The performed tests did not indicate any effect on netting strength from a simulated single, traditional bath disinfection as performed at service stations applying the disinfectant Aqua Des containing peracetic acid. However, increasing the Aqua Des concentration from 1 to 10 % resulted in a strength reduction of 3–6 %. Simulated spill of concentrated Aqua Des on the jump fence of a net with copper coating residuals resulted in a severe reduction in strength of 45 %. This strength loss was probably a consequence of chemical reaction between copper and Aqua Des, and uncoated netting did not experience any loss in strength subjected to the same chemical exposure. These findings from application of Aqua Des should also apply to other peracetic acid disinfection chemicals with trade names as for example Perfectoxid and Addi Aqua.

In recent years there is an increase in consumption of food products and the supply of fresh vegetables to the consumer is getting more and more popular. However, this group of products is among the fastest perishing products. It is because of environmental and internal factors in vegetables during storage are unavoidable. During the preparation for the market vegetables are being cleaned, washed, sanded, sorted and dried. This consumes a lot of energy and water. Different technological measures are used to reduce the consumption of natural resources during the preparation of products for the market and to slow down their quality changes. Ozone is an effective measure to slow down product bio destruction. Ozone usage in small doses as a disinfectant is recognized as safe. Although there are a lot of publications in the usage of ozone, but its impact on vegetable qualitative indicators has not been sufficiently investigated. There is a lack of research in the analysis of the effects of ozonated water, which can be successfully used in vegetable washing technologies. The article analyzes the effect of ozonated water treatment on fresh carrots colour and quantity of carotenoids. The obtained data showed that the use of ozonated water in concentration of 1.53 ± 0.09 mg L-1 did not have an effect on the amount carotenoids accumulated in the products. Also, ozonated water did not have significant effect on the colour of products.

Chlorine disinfection is one of the most common used techniques to eliminate the ballast water organisms. However safety risks during handling and onboard storage of chlorine gas or HOCl solutions are subjects of concern. Electrochemical generation of active chlorine on board would eliminate such unfavorable features of chlorine disinfection. The characteristics of seawater have a direct effect on the capability of an electrochemical system to function successfully. Seawater contains a wide range of salts at various concentrations and combinations. Additionally, coastal seawater may also contain ammonia beside domestic based organic pollutants. The aim of this study is to determine the effect of ammonia which will go under electrochemical process during disinfectant production. It is figured out that ammonia leads to less total and free available chlorine concentrations in electrochemically generated disinfectant. Consequently, the presence of ammonia increases the volume of disinfectant needed to disinfect the same amount of biomass. This work has been conducted within the project “BaWaPla — Sustainable Ballast Water Management Plant”, funded by the European Union under contract number 031529, which is started at 15/11/2006 and finalized at 15/05/2010.

Biocidal products (disinfectants) are intensively used in nursing homes to control and prevent the spread of microorganisms and healthcare associated infections. We checked the hygiene of the surfaces intended for multiple use and the microbial population present on these surfaces. In three different areas, we noticed the working protocol and the biocidal products in use. The surfaces of the devices were sampled with swabbing before use, after use and after disinfection. Identification and quantification of microorganisms was performed using classical culture methods and MALDI-TOF method. The results showed that some devices were contaminated before use. Of particular concern is the fact that microorganisms remain on the devices even after disinfection in concentrations from 1 to 300 cfu/mL. In complex microbial communities on surfaces and with intensive use of disinfectants, the acquired bacterial resistance to disinfectants can develop, which can consequently lead to increased bacterial resistance to antibiotics.