sodium-hypochlorite and troclosene

This review aims to provide relevant, aggregate information about a variety of disinfectants and antiseptics, along with potential utility and limitations. While not exhaustive, this review's goal is to add to the body of literature available on this topic and give interventional providers and practitioners an additional resource to consider when performing procedures.. In the current SARS-CoV2 epidemiological environment, infection control and costs associated with healthcare-associated infections (HAIs) are of paramount importance. Even before the onset of SARS-CoV2, HAIs affected nearly 2million patients a year in the USA and resulted in nearly 90,000 deaths, all of which resulted in a cost to hospitals ranging from US$28 billion to 45 billion. The onset SARS-CoV2, though not spread by an airborne route, has heightened infection control protocols in hospitals and, as such, cast a renewed focus on disinfectants and their utility across different settings and organisms. The aim of this review is to provide a comprehensive overview of disinfectants used in the inpatient setting.

Topics: Chlorine Compounds; Cross Infection; Disinfectants; Ethanol; Formaldehyde; Glutaral; Humans; Hydrogen Peroxide; Iodophors; Oxides; Peracetic Acid; Phenol; Povidone-Iodine; Quaternary Ammonium Compounds; Sodium Hypochlorite; Triazines

Household water treatment using sodium hypochlorite (NaOCl) has been recognized as a cost-effective means of reducing the heavy burden of diarrhea and other waterborne diseases, especially among populations without access to improved water supplies. Sodium dichloroisocyanurate (NaDCC), which is widely used in emergencies, is an alternative source of chlorine that may present certain advantages over NaOCl for household-based interventions in development settings. We summarize the basic chemistry and possible benefits of NaDCC, and review the available literature concerning its safety and regulatory treatment and microbiological effectiveness. We review the evidence concerning NaDCC in field studies, including microbiological performance and health outcomes. Finally, we examine studies and data to compare NaDCC with NaOCl in terms of compliance, acceptability, affordability and sustainability, and suggest areas for further research.

Topics: Developing Countries; Diarrhea; Disinfectants; Humans; Sodium Hypochlorite; Triazines; Water Microbiology; Water Purification; Water Supply

Chlorine-based disinfectants are commonly used in rooms of patients with Candida auris, but there is uncertainty regarding optimal concentrations that provide efficacy while minimizing the potential for adverse effects. We found that 2 chlorine-based disinfectants were effective against C auris with 1 minute of contact time at concentrations of 4,000 parts per million or higher. Lower concentrations were effective only with increased contact times that may not be practical in real-world health care settings.

Topics: Candida; Disinfectants; Dose-Response Relationship, Drug; Sodium Hypochlorite; Time Factors; Triazines

Pathogens in drain biofilms pose a significant risk for hospital-acquired infection. However, the evidence of product effectiveness in controlling drain biofilm and pathogen dissemination are scarce. A novel in-vitro biofilm model was developed to address the need for a robust, reproduceable and simple testing methodology for disinfection efficacy against a complex drain biofilm.. Identical complex drain biofilms were established simultaneously over 8 days, mimicking a sink trap. Reproducibility of their composition was confirmed by next-generation sequencing. The efficacy of sodium hypochlorite 1000 ppm (NaOCl), sodium dichloroisocyanurate 1000 ppm (NaDCC), non-ionic surfactant (NIS) and peracetic acid 4000 ppm (PAA) was explored, simulating normal sink usage conditions. Bacterial viability and recovery following a series of 15-min treatments were measured in three distinct parts of the drain.. The drain biofilm consisted of 119 mixed species of Gram-positive and -negative bacteria. NaOCl produced a >4 log. Drains are one source of microbial pathogens in healthcare settings. Microbial biofilms are notoriously difficult to eradicate with conventional chemical biocidal products. The development of this reproducible in-vitro drain biofilm model enabled understanding of the impact of biocidal products on biofilm spatial composition and viability in different parts of the drain.

Topics: Biofilms; Cross Infection; Disinfectants; Disinfection; Hospitals; Peracetic Acid; Reproducibility of Results; Sodium Hypochlorite; Surface-Active Agents; Triazines; Water Supply

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

Topics: Benzalkonium Compounds; Brassica; Colony Count, Microbial; Color; Disease Outbreaks; Disinfectants; Fast Foods; Food Contamination; Food Handling; Food Microbiology; Microbiota; Salmonella typhimurium; Sodium Hypochlorite; Triazines; Ultrasonic Waves

Microbial contamination is an unavoidable problem in industrial processes. Sodium hypochlorite (SH) is the most common biocide used for industrial disinfection. However, in view of the current societal concerns on environmental and public health aspects, there is a trend to reduce the use of this biocide as it can lead to the formation of organochlorinated carcinogenic compounds. In this work the efficacy of SH was assessed against Escherichia coli in planktonic and biofilm states and compared with three alternative chlorine-based biocides: neutral electrolyzed oxidizing water (NEOW), chlorine dioxide (CD) and sodium dichloroisocyanurate (NaDCC). The planktonic tests revealed that SH had the fastest antimicrobial action, NaDCC exhibited the highest antimicrobial rate and NEOW caused the highest antimicrobial effects. Additionally, NEOW was the biocide that allowed the highest formation of reactive oxygen species (ROS). In biofilm control, NEOW and CD were the most efficient biocides causing 3.26 and 3.20 log CFU·cm

Topics: Biofilms; Chlorine Compounds; Disinfectants; Equipment Contamination; Escherichia coli; Industrial Microbiology; Microbial Viability; Oxides; Reactive Oxygen Species; Sodium Hypochlorite; Time Factors; Triazines; Water

The ability of Clostridium difficile to form highly resilient spores which can survive in the environment for prolonged periods causes major contamination problems. Antimicrobial 405 nm light is being developed for environmental decontamination within hospitals, however further information relating to its sporicidal efficacy is required. This study aims to establish the efficacy of 405 nm light for inactivation of C. difficile vegetative cells and spores, and to establish whether spore susceptibility can be enhanced by the combined use of 405 nm light with low concentration chlorinated disinfectants. Vegetative cells and spore suspensions were exposed to increasing doses of 405 nm light (at 70-225 mW/cm(2)) to establish sensitivity. A 99.9% reduction in vegetative cell population was demonstrated with a dose of 252 J/cm(2), however spores demonstrated higher resilience, with a 10-fold increase in required dose. Exposures were repeated with spores suspended in the hospital disinfectants sodium hypochlorite, Actichlor and Tristel at non-lethal concentrations (0.1%, 0.001% and 0.0001%, respectively). Enhanced sporicidal activity was achieved when spores were exposed to 405 nm light in the presence of the disinfectants, with a 99.9% reduction achieved following exposure to 33% less light dose than required when exposed to 405 nm light alone. In conclusion, C. difficile vegetative cells and spores can be successfully inactivated using 405 nm light, the sporicidal efficacy can be significantly enhanced when exposed in the presence of low concentration chlorinated disinfectants. Further research may lead to the potential use of 405 nm light decontamination in combination with selected hospital disinfectants to enhance C. difficile cleaning and infection control procedures.

Topics: Chlorine Compounds; Clostridioides difficile; Decontamination; Disinfectants; Drug Synergism; Light; Microbial Sensitivity Tests; Oxides; Sodium Hypochlorite; Spores, Bacterial; Triazines

In Ebola Virus Disease (EVD) outbreaks, it is widely recommended to wash living things (handwashing) with 0.05% (500 mg/L) chlorine solution and non-living things (surfaces, personal protective equipment, dead bodies) with 0.5% (5,000 mg/L) chlorine solution. Chlorine solutions used in EVD response are primarily made from powdered calcium hypochlorite (HTH), granular sodium dichloroisocyanurate (NaDCC), and liquid sodium hypochlorite (NaOCl), and have a pH range of 5-11. Chlorine solutions degrade following a reaction highly dependent on, and unusually sensitive to, pH, temperature, and concentration. We determined the shelf-life of 0.05% and 0.5% chlorine solutions used in EVD response, including HTH, NaDCC, stabilized NaOCl, generated NaOCl, and neutralized NaOCl solutions. Solutions were stored for 30 days at 25, 30, and 35°C, and tested daily for chlorine concentration and pH. Maximum shelf-life was defined as days until initial concentration fell to <90% of initial concentration in ideal laboratory conditions. At 25-35°C, neutralized-NaOCl solutions (pH = 7) had a maximum shelf-life of a few hours, NaDCC solutions (pH = 6) 2 days, generated NaOCl solutions (pH = 9) 6 days, and HTH and stabilized NaOCl solutions (pH 9-11) >30 days. Models were developed for solutions with maximum shelf-lives between 1-30 days. Extrapolating to 40°C, the maximum predicted shelf-life for 0.05% and 0.5% NaDCC solutions were 0.38 and 0.82 hours, respectively; predicted shelf-life for 0.05% and 0.5% generated NaOCl solutions were >30 and 5.4 days, respectively. Each chlorine solution type offers advantages and disadvantages to responders, as: NaDCC is an easy-to-import high-concentration effervescent powder; HTH is similar, but forms a precipitate that may clog pipes; and, NaOCl solutions can be made locally, but are difficult to transport. We recommend responders chose the most appropriate source chlorine compound for their use, and ensure solutions are stored at appropriate temperatures and used or replaced before expiring.

Topics: Calcium Compounds; Chlorine Compounds; Disinfectants; Disinfection; Drug Stability; Ebolavirus; Hand Disinfection; Hemorrhagic Fever, Ebola; Humans; Sodium Hypochlorite; Triazines

The aim of this study was to determine the effect of household bleach, a sodium dichloroisocyanurate (NaDCC)-based disinfectant and an eco-friendly cleaning agent (EFCA) on four Staphylococcus aureus strains, including two isolated from community infections. The products were assessed using the suspension (EN 1276) and surface (EN 13697) tests, while biofilm activity was determined using the 96-well plate method. Bleach and NaDCC caused > 5 log reduction in viable counts within 5 min in suspension, whilst on surfaces the reduction was < 3 log. Bleach at 5000 ppm free available chlorine completely eradicated MSSA NCTC 13297 and PVL CA MSSA biofilms within 10 min, but not at 500 and 50 ppm, NaDCC was less effective against biofilms. The EFCA demonstrated no antimicrobial activity. It is of concern that at the recommended "use" dilution, bleach did not eradicate biofilms. Although increasing contact time and/or concentration should improve the activity, this may not be acceptable to the user.

Topics: Biofilms; Citrates; Cyclohexenes; Disinfectants; Ethanol; Lactic Acid; Limonene; Microbial Sensitivity Tests; Sodium Citrate; Sodium Hypochlorite; Staphylococcus aureus; Terpenes; Triazines

Sodium dichloroisocyanurate (NaDCC) is a chemical agent that acts against microorganisms in a manner similar to that of sodium hypochlorite by releasing free available chlorine. NaDCC has been approved by the WHO for the emergency treatment of water and by the US EPA for routine treatment of water. Previous studies assessing the effectiveness of NaDCC for the treatment of water implied that NaDCC should have a wide array of disinfecting effects beyond the treatment of planktonic cells in potable water. In this study the biocidal effects of NaDCC against Pseudomonas aeruginosa cells in different growth modes including planktonic cells and biofilms were explored. The data showed that a 60% dilution of the standard NaDCC solution was effective in the treatment of both P. aeruginosa planktonic cells and biofilms.

Topics: Biofilms; Disinfectants; Disinfection; Drinking Water; Plankton; Pseudomonas aeruginosa; Sodium Hypochlorite; Triazines; Water Purification

Almost a billion persons lack access to improved drinking water, and diarrheal diseases cause an estimated 1.87 million deaths per year. Sodium dichloroisocyanurate (NaDCC) tablets are widely recommended for household water treatment to reduce diarrhea. Because NaDCC is directly added to untreated water sources, concerns have been raised about the potential health impact of disinfection by-products. This study investigated trihalomethane (THM) production in water from six sources used for drinking (0.6-888.5 nephelometric turbidity units) near Arusha, Tanzania. No sample collected at 1, 8, and 24 hours after NaDCC addition exceeded the World Health Organization guideline values for either individual or total THMs. Ceramic filtration, sand filtration, cloth filtration, and settling and decanting were not effective mitigation strategies to reduce THM formation. Chlorine residual and THM formation were not significantly different in NaDCC and sodium hypochlorite treatment. Household chlorination of turbid and non-turbid waters did not create THM concentrations that exceeded health risk guidelines.

Topics: Chlorine; Diarrhea; Disinfectants; Disinfection; Fresh Water; Halogenation; Sodium Hypochlorite; Tanzania; Triazines; Trihalomethanes; Water Microbiology; Water Pollutants, Chemical; Water Purification; Water Supply; World Health Organization

Because of spore formation, Bacillus anthracis is considered the most resistant biological warfare agent known. The present study aimed to assess and compare well-known decontamination routes to inactivate the spores on daily-use environmental tools contaminated previously. To simulate the agent, Bacillus atrophaeus was used. Various environmental samples (such as tile, fabric clothing, wood, protective suit, glass, paper, soil, water, plastic, and metal) that may be contaminated after a biological incident were used as test carriers and inoculated with B. atrophaeus. Sodium hypochlorite, free chlorine, autoclaving, ethylene oxide, hydrogen peroxide, ultraviolet irradiation, and boiling decontaminated the samples. Glutaraldehyde (2%) and free chlorine solution (10,000 mg/L) were also found to be effective in decontaminating the samples and are recommended as alternatives to the use of sodium hypochlorite solution. Soil, tile, paper, and metal were determined to be the most difficult materials to decontaminate. It was concluded that 5% hypochlorite adjusted with acetic acid might also be used for decontamination. Decontamination strategies to reduce contamination of the environment by biological warfare agents need to be applied to mitigate the number of victims, in terms of prominent characteristics like cost-effectiveness and user-friendliness.

Topics: Bacillus anthracis; Bacillus subtilis; Bioterrorism; Ceramics; Decontamination; Disinfectants; Equipment Contamination; Ethylene Oxide; Glutaral; Humans; Metals; Paper; Sodium Hypochlorite; Soil Microbiology; Spores, Bacterial; Triazines

The antimicrobial and cytotoxic effects of sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) were evaluated and compared in vitro. The minimal inhibitory concentration and minimal bactericidal concentration of NaOCl and NaDCC were tested for Streptococcus sobrinus, Streptococcus salivarius, Enterococcus faecalis, and Streptococcus mutans. The cytotoxic effect was assessed by using human fibroblast tissue culture. Survival rate was assessed by a protein determination method. Results showed that the minimal inhibitory concentration and minimal bactericidal concentration values of NaOCl and NaDCC for the tested bacteria were in a similar range. NaDCC in concentrations higher than 0.02%, and NaOCl in concentrations higher than 0.01% were lethal to fibroblasts. In conclusion it seems that both agents were very effective in killing bacteria, and their cytotoxicity to fibroblasts in tissue culture was similar.

Topics: Anti-Infective Agents, Local; Cell Survival; Chlorine; Culture Techniques; Disinfectants; Enterococcus faecalis; Fibroblasts; Humans; Microbial Sensitivity Tests; Skin; Sodium Hypochlorite; Streptococcus; Streptococcus mutans; Streptococcus sobrinus; Triazines

Topics: Disinfectants; Disinfection; Ear Canal; Humans; Sodium Hypochlorite; Syringes; Triazines

The role of membrane fatty acid composition in the resistance of Pseudomonas aeruginosa ATCC 15442 to the bactericidal activity of Quaternary Ammonium Compounds (QACs) was investigated. The strain was grown in a medium with increasing concentrations of a QAC, benzyldimethyltetradecylammonium chloride (C14) and two non-QACs, sodium dichloroisocyanurate and tri-sodium phosphate. In the presence of C14 only, the strain was able to grow in concentrations higher than the minimal inhibitory concentration. As the strain adapted to C14, resistance to bactericidal activity of the same biocide increased. For the non-QACs, no change was noted when cells were grown in the presence of biocides. The C14-adapted cells showed variations in membrane fatty acid composition. A hierarchical clustering analysis was used to compare all fatty acid compositions of cultures in the presence, or not, of the three biocides used here and another QAC studied previously. The clusters obtained underlined specific variations of membrane fatty acids in response to the presence of QACs. Furthermore, with a simple linear regression analysis, a relationship was shown between the membrane fatty acids and the resistance developed by the strain against the bactericidal activity of C14.

Topics: Adaptation, Physiological; Benzalkonium Compounds; Disinfectants; Drug Resistance, Microbial; Fatty Acids; Membrane Lipids; Pseudomonas aeruginosa; Quaternary Ammonium Compounds; Regression Analysis; Sodium Hypochlorite; Triazines

Macerates of bovine brain infected with bovine spongiform encephalopathy (BSE) agent, and rodent brain infected with the 263K or ME7 strains of scrapie agent, were subjected to porous-load autoclaving at temperatures between 134 and 138 degrees C for < or = 60 min. Bioassay in rodents showed that none of the regimens produced complete inactivation. Homogenates of BSE-infected bovine brain were exposed for < or = 120 min to solutions of sodium hypochlorite or sodium dichloroisocyanurate containing < or = 16,500 ppm available chlorine. There was no detectable survival of infectivity after the hypochlorite treatments but none of the dichloroisocyanurate solutions produced complete inactivation. Homogenates of BSE-infected bovine brain, and rodent brain infected with the 263K and ME7 strains of scrapie agent, were exposed for < or = 120 min to 1M or 2M sodium hydroxide but no procedure produced complete inactivation of all agents tested.

Topics: Animals; Cattle; Disinfection; Encephalopathy, Bovine Spongiform; Hot Temperature; Mice; Mice, Inbred C57BL; PrPSc Proteins; Scrapie; Sodium Hydroxide; Sodium Hypochlorite; Triazines

Spores of Bacillus subtilis NCTC 8236 were treated with biocides and then subjected to various revival procedures. Sodium hydroxide (optimum concentration 25 mmol l-1) revived a small portion of glutaraldehyde-treated spores but not of spores exposed to formaldehyde, polyvinylpyrrolidone-iodine (PVP-I), Lugol's iodine, sodium hypochlorite or sodium dichloroisocyanurate (NaDCC). Post-treatment heat shock (at 70 degrees or 80 degrees C) increased the numbers of colony-forming units (cfu) of formaldehyde-injured spores. Coat-extraction procedures had the greatest effect on iodine-pretreated spores. The uptake of iodine and chlorine was more rapid and occurred to a greater extent with outgrowing, germinating and especially coat-deficient spores than with mature, resting spores.

Topics: Antiviral Agents; Bacillus subtilis; Capsid; Disinfectants; Endopeptidase K; Formaldehyde; Glutaral; Hot Temperature; Iodides; Pronase; Serine Endopeptidases; Sodium Hydroxide; Sodium Hypochlorite; Spores, Bacterial; Staining and Labeling; Triazines

The susceptibility of duck hepatitis B virus (DHBV) to the virucidal effects of sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) was compared to hepatitis B virus (HBV) with the aim of using the duck as a model for studying HBV disinfection. Using viral DNA polymerase (DNAP) as a target, inhibition of DNAP activity by chlorine disinfectants was found to be concentration-dependent but independent of contact time. Two minute exposure of minimal effective concentrations of sodium hypochlorite (domestic bleach: 3600 ppm and industrial bleach: 3180 ppm) and sodium dichloroisocyanurate (3000 ppm available chlorine) to DHBV- and HBV-rich plasma totally inhibited DNA polymerase activity. DHBV particles in DHBV-carrier duck plasma (10(4.5) ID50/mL) were treated with these concentrations and inoculated intravenously into 18 one-day old ducklings (six animals/disinfectant). Analysis of plasma (0, 7 and 14 days post-infection) and post-mortem liver (14 days post-infection) by DNA hybridization techniques showed that DHBV DNA was undetectable in samples from all animals inoculated with disinfected virus particles. However, post-inoculation plasma and liver of 18 of 18 control ducklings inoculated with untreated virions were positive for DHBV DNA. These results show for the first time that total inhibition in vitro of hepadnavirus DNA polymerase activity by chemical disinfectants is predictive of inactivation of infectivity in vivo.

Topics: Animals; Disinfectants; Disinfection; DNA, Viral; Ducks; Hepadnaviridae Infections; Hepatitis B virus; Hepatitis B Virus, Duck; Humans; Hypochlorous Acid; Liver; Models, Biological; Sodium Hypochlorite; Triazines

A new microbial bioluminescence assay has been used to monitor the loss of mutagenicity on inactivation of methotrexate by active chlorine-based agents. The drug was degraded to products that were non-active in this mutagen detection system, in agreement with previously described work. Presept granules appear to be a suitable alternative to sodium hypochlorite for inactivating solutions and surface spills of methotrexate. The bioluminescence assay appears to have potential for monitoring clean-up and decontamination procedures in areas where cytotoxic agents are used.

Topics: Biological Assay; Chlorine; Decontamination; Luminescent Measurements; Methotrexate; Mutagenicity Tests; Sodium Hypochlorite; Solutions; Triazines

Spores of Bacillus subtilis NCTC 8236 exposed at 22 degrees C to test biocides (alkaline glutaraldehyde, an iodophor, Lugol's solution, sodium hypochlorite and sodium dichloroisocyanurate) demonstrated varying degrees of injury to stressing agents (sodium hydroxide, sodium lauryl sulphate, polymyxin B sulphate or cetylpyridinium chloride) incorporated into a recovery agar medium. This injury to stressing agents was expressed mainly during outgrowth.

Topics: Bacillus subtilis; Cetylpyridinium; Chlorine; Disinfectants; Glutaral; Iodine; Polymyxin B; Povidone; Sodium Dodecyl Sulfate; Sodium Hydroxide; Sodium Hypochlorite; Spores, Bacterial; Triazines

Solutions of chlorine-releasing agents (CRAs) show varying activity against Bacillus subtilis spores; sodium hypochlorite (NaOCl) shows higher activity than sodium dichloroisocyanurate (NaDCC) which is more active than chloramine-T. Investigations with coat- and cortex-extracted spores indicate that resistance to CRAs depends not only on the spore coat but also the cortex. Whereas extraction of alkali-soluble coat protein increased sensitivity to NaOCl and NaDCC, degradation of coat and cortex material was required to achieve significant activity with chloramine-T. NaOCl (in the presence and absence of NaOH) and NaDCC (in the presence of NaOH only) produced degradation of spore coat and cortex material which may be related to their rapid sporicidal action at low concentrations under these conditions. By contrast, chloramine-T produced no degradation of cortex peptidoglycan and was only effective against normal and alkali-treated spores at high concentrations, requiring extraction of peptidoglycan with urea/dithiothreitol/sodium lauryl sulphate (UDS) or UDS/lysozyme to achieve significant activity at low concentrations. Results suggest that the sporicidal action of CRAs is associated with spore coat and cortex degradation causing rehydration of the protoplast allowing diffusion to the site of action on the underlying protoplast.

Topics: Bacillus subtilis; Chloramines; Disinfectants; Dithiothreitol; Muramidase; Peptidoglycan; Picolinic Acids; Sodium Dodecyl Sulfate; Sodium Hydroxide; Sodium Hypochlorite; Spores, Bacterial; Tosyl Compounds; Triazines; Urea

Topics: Body Fluids; Disinfection; Humans; Sodium Hypochlorite; Triazines

Sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) were more active against Bacillus subtilis 8236 spores in both viability and in germination and outgrowth studies than were polyvinylpyrrolidone-iodine (PVP-I) and Lugol's solution. Of the two chlorine compounds studied NaOCl proved to be the more active. The two iodine-containing compounds gave contrasting results with the Lugol's solution demonstrating increased antibacterial activity with increasing available iodine concentration. The antibacterial behaviour of PVP-I, however, reflected the more complex nature of aqueous iodine-surfactant mixtures. Initially, non-complexed iodine concentration (the active species) increased with increasing total available iodine concentration, resulting in increasing antibacterial activity. However, due to changes in the physical properties of the mixture, a maximum concentration of non-complexed iodine was reached so that a further increase in total available iodine resulted in a decrease in non-complexed iodine concentration and consequently a decrease in the antibacterial activity of the solution was observed. A greater inhibitory effect was observed in subsequent germination and outgrowth studies when spores were pre-treated with respective biocide than when untreated spores were added to germination media containing biocide at t = 0. This may reflect a combination of different contact times plus the neutralizing effect of the germination media on such halogen compounds.

Topics: Bacillus subtilis; Disinfectants; Iodides; Povidone-Iodine; Sodium Hypochlorite; Solutions; Spores, Bacterial; Triazines

Using a quantitative suspension test method, the antiviral activity of sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) against human immunodeficiency virus (HIV) was investigated. Viral suspensions were prepared containing 10(4)-10(5) syncitial forming units ml-1 in 0.9% saline or 0.9% saline containing 10% v/v plasma to simulate clean and dirty conditions. A syncitial inhibition assay on C8166 lymphoblastoid line was used to determine viral titre. Results indicate that satisfactory disinfection (3-4 log reduction in 2 min) can be achieved using NaDCC and NaOCl at concentrations of 50 ppm and 2500 ppm available chlorine (AvCl2) for clean and soiled conditions respectively. For treatment of blood spillages, the addition of NaDCC and NaOCl solutions (10,000 ppm) to equal volumes of contaminated blood (giving a final AvCl2 concentration of 5000 ppm of blood) was sufficient to produce total kill within 2 min. For treatment of spillage material, chlorine-releasing powder formulations--which produce higher AVCl2 concentrations and achieve containment of spillage material--offer an effective alternative.

Topics: Antiviral Agents; Disinfection; Environmental Microbiology; Evaluation Studies as Topic; HIV-1; Humans; Sodium Hypochlorite; Sterilization; Triazines

A comparison has been made of the activity against Pseudomonas aeruginosa of sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) solutions containing 0-40% and 0-70% horse serum respectively. The degree of inactivation of NaOCl and of NaDCC solutions by different concentrations of horse serum is expressed in terms of a neutralization coefficient, which demonstrates that NaDCC solutions are less prone to inactivation by serum than are NaOCl solutions, the disparity diverging as serum concentration is increased. In 30% serum an NaDCC solution containing 4000 ppm of available chlorine exhibited similar bactericidal activity to an NaOCl solution containing 17,000 ppm available chlorine.

Topics: Blood; Disinfectants; Pseudomonas aeruginosa; Sodium Hypochlorite; Triazines

The efficacy of nine disinfectants on Mycobacterium smegmatis was tested in the presence of sputum, using quantitative suspension and carrier tests. Glutaraldehyde, povidone iodine, and chlorhexidine gluconate produced at least a 6-log10 reduction in CFU in all tests. Four disinfectants (sodium dichloroisocyanurate, phenol, ethanol, and sodium hypochlorite) were not as effective in the carrier tests as in the suspension tests; this difference ranged from a 1- to a 5-log10 reduction in CFU. The efficacy of ethanol and sodium hypochlorite was further reduced (3- and 1-log10 reductions in CFU, respectively) in the presence of sputum. The quaternary ammonium compound and iodophor were ineffective in all tests. The findings of this study demonstrate the need for a quantitative carrier test such as the one presented here.

Topics: Aerosols; Chlorhexidine; Colony Count, Microbial; Disinfectants; Ethanol; Glutaral; Humans; Mycobacterium; Phenol; Phenols; Povidone-Iodine; Sodium Hypochlorite; Sputum; Triazines

Topics: Disinfectants; Drug Stability; Sodium Hypochlorite; Solutions; Tablets; Triazines

The antibacterial activity of unbuffered sodium dichloroisocyanurate (NaDCC) (pH 6.6) and of sodium hypochlorite (NaOCl) buffered to pH 7.2, 9.0 and 10.6 was compared. Under clean conditions, solutions of NaDCC at pH 6.6 or NaOCl at pH 7.2 and 9.0 with 100-200 mg l-1 available chlorine showed satisfactory disinfectant activity against vegetative bacteria. Sporicidal action required higher concentrations of both agents, and NaOCl at pH 7.2 showed most activity. In the presence of organic matter NaDCC offers significant advantages over NaOCl, a 3000 mg l-1 solution of NaDCC giving satisfactory activity in the presence of plasma concentrations up to 20% v/v compared with NaOCl solutions at pH 7.2, 9.0 and 10.6 which were inactivated at chlorine concentrations up to 5000 mg l-1. Although NaOCl pH 10.6 showed satisfactory disinfectant activity under clean conditions, our results indicate that formulations at this pH should not be used where sporicidal action is required or where substantial organic soiling is anticipated.

Topics: Bacillus subtilis; Disinfectants; Hospitals; Hydrogen-Ion Concentration; Microbial Sensitivity Tests; Plasma; Sodium Hypochlorite; Solutions; Spores, Bacterial; Staphylococcus aureus; Triazines

A comparison of commercial sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) products was made. Solutions of NaOCl and NaDCC containing the same levels of available chlorine (av.Cl) exhibited very similar bactericidal activities, despite significant differences in pH. A level of 12.5 ppm av. Cl achieved a greater than 5 log 10 reduction of Staphylococcus aureus in 2 min. A level of 5 ppm av.Cl achieved a greater than 5 log 10 reduction of Pseudomonas aeruginosa in 2 min whilst approximately 100 ppm av.Cl achieved the same reduction in the presence of 1% horse serum, and approximately 200 ppm av.Cl in the presence of 2% horse serum, indicating inactivation levels of around 95 and 97.5% respectively. Tablets of NaDCC were stable but solutions were unstable and decomposed much faster than NaOCl solutions of the same strength. Batch-to-batch variability of different NaOCl and NaDCC products was investigated; whilst NaDCC products always contained the minimum level of av.Cl specified, concentrated NaOCl products sometimes did not due to inherent instability.

Topics: Disinfectants; Drug Stability; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Sodium Hypochlorite; Solutions; Staphylococcus aureus; Tablets; Triazines

Nine postmilking teat dips were evaluated by an experimental challenge model against either Staphylococcus aureus, Streptococcus agalactiae, or both. Formulations containing .9 and .6% sodium hypochlorite, 1% sodium dichloro-s-triazene-trione, .55% chlorhexidine gluconate, and .35% povidone iodine reduced incidence of Staphylococcus aureus infections 56.8, 28.3, 75.9, 92.5, and 77.9%. Incidence of infections with Streptococcus agalactiae was reduced 48.1 and 63.2% by 1.7 and 1% sodium dichloro-s-triazene-trione formulations. The 1% chlorhexidine gluconate and .35% povidone iodine products reduced Streptococcus agalactiae infections 71.0 and 67.0%. Three experimental 1% iodophor formulations reduced Streptococcus agalactiae infections 28.9, 44.8, and 50.7%. The experimental challenge model was refined further and provided an efficient method to determine efficacy of postmilking teat dips.

Topics: Administration, Topical; Animals; Cattle; Chlorhexidine; Disinfectants; Drug Evaluation; Female; Iodophors; Mammary Glands, Animal; Mastitis, Bovine; Povidone-Iodine; Sodium Hypochlorite; Staphylococcal Infections; Staphylococcus aureus; Streptococcal Infections; Streptococcus agalactiae; Triazines

To evaluate products intended for disinfection of water in swimming pools a quantitative suspension test was designed based on the principle of the Dutch standard suspension test (SST). As artifical swimming pool water a buffered bovine albumin solution (BBAS) was used. The microbicidal potency of BBAS chlorinated with sodium hypochlorite (NaOC1) for 5 min to free chlorine concentractions of 0.3, 0.5 and 1 mg/1 appeared to meet the tentative standard of 4 decimals reduction (D.R.) within 5 min against the bacterial test strains used, e.g. Staph, aureus, Str. faecalis, P. aeruginosa, E. coli and Prot. mirabilis. Usually an exposure time of 30 s was sufficient to obtain this reduction. The kill C. albicans to that extent approx. 1 mg/1 free chlorine was needed. The redox potential of BBAS chlorinated as described above amounted to approx. 600 mV or higher values. When BBAS was chlorinated for 5 min with sodium dichloroisocyanurate (NaDCC) addition of 8 mg/1 of this substance was required to obtain about the same microbicidal potency as that of BBAS chlorinated with NaOC1 to 0.3 mg/1 free chlorine. The redox potential in the former solution was found to be above 600 mV. The microbicidal potency of BBAS chlorinated for 5 minutes with 2 mg/1 NaDCC was virtually zero and with 4 mg/1 NaDCC suboptimal. These findings correlated well with the redox potentials of 262 mV and 432 mV, respectively, measured in the latter solutions. Addition of cyanuric acid to BBAS before chlorination resulted in lower killing rates, although the free chlorine concentration, determined with the FAS-DPD method, seemed to be increased. It is concluded that in swimming pool water chlorinated with chloroisocyanurates the redox potential might be a better indicator for the microbicidal potency than the free chlorine concentration determined with the FAS-DPD method.

Topics: Albumins; Bacteria; Disinfectants; Disinfection; Methods; Oxidation-Reduction; Sodium Hypochlorite; Suspensions; Swimming Pools; Triazines; Water Microbiology

Topics: Bacteria; Candida albicans; Disinfectants; Hydrogen-Ion Concentration; Sodium Hypochlorite; Species Specificity; Triazines