Residual biomass from surfactin production is a source of arginase and adsorbed surfactin that is useful for environmental remediation.

Lipopeptides are important secondary metabolites produced by microbes. They find applications in environmental decontamination and in the chemical, pharmaceutical and food industries. However, their production is expensive. In the present work we propose three strategies to lower the production costs of surfactin. First, the coproduction of surfactin and arginase in a single growth. Second, extract the fraction of surfactin that adsorbs to the biomass and is removed from the growth medium through centrifugation. Third, use microbial biomass for the remediation of organic and inorganic contaminants. The coproduction of surfactin and arginase was evaluated by factorial design experiments using the LB medium supplemented with arginine. The best conditions for surfactin production were 22 h of growth at 37 °C using LB supplemented with arginine 7.3 g/L. Almost similar conditions were found to produce highest levels of arginase, 24 h and 6.45 g/L arginine. Decontamination of phenol and copper from artificial samples was attained by treatment with residues from lipopeptide production. Thus, cell suspensions and wash-waters used to extract surfactin from the biomass. Cell suspensions were used to successfully remove hydroquinone. Cell suspensions and wash-waters containing surfactin were successfully used to recover copper from solution. Specific monitoring methods were used for phenol and metal solutions, respectively a biosensor based on tyrosinase and either atomic absorption flame ionization spectrometry or absorbance coupled to the Arduino™ platform. Therefore, we report three alternative strategies to lower the production costs in lipopeptide production, which include the effective recovery of copper and phenol from contaminated waters using residues from surfactin production. Sustainable and profitable production of surfactin can be achieved by a coproduction strategy of lipopeptides and enzymes. Lipopeptides are collected in the supernatant and enzymes in the biomass. In addition, lipopeptides that coprecipitate with biomass can be recovered by washing. Lipopeptide wash-waters find applications in remediation and cells can also be used for environmental decontamination.

Treatment technologies for pharmaceutical effluents-A scientometric study.

Treatment of highly polluted pharmaceutical effluents is a major challenge all over the world for technical and economic considerations. In this study, scientometric study is performed on the application of various methods for the treatment of pharmaceutical effluents to explore further developments. In this regard, a total of 1964 documents were retrieved from the Web of Science (WoS) database using a set of relevant keywords to cover all published documents. The extracted documents were subjected to scientometric study including the contributed authors, publications, citations received, contributing countries and institutions as well as the subject categories. From the data retrieved, the status of scientific knowledge on the subject history and current trends were identified and scientific gaps were critically discussed. Publications in this area started to appear since the sixties and were considerably promoted around the beginning of 2000s. Scientific publications of years 1960-2018 followed sigmoidal trend. It was found that leading countries are China and the United States in terms of scientific output on treatment technologies for pharmaceutical effluents. Among the active journals published, "Water Research" has received the most citations. A detailed discussion on the science and developments in this field is provided including the potential applications of scientometry.

Activity of Hospital Disinfectants against Vegetative Cells and Spores of Clostridioides difficile Embedded in Biofilms.

Clostridioides difficile spores can survive in the environment in either mono- or mixed-species biofilms. However, no previous studies have investigated chemical disinfection of C. difficile spores embedded in biofilms. Thus, the purpose of this study was to assess the in vitro effectiveness of hospital disinfectants against C. difficile spores embedded within biofilms. Five unique C. difficile strains embedded in three different biofilm types grown for 72 or 120 h were exposed to seven different hospital disinfectants. C. difficile abundance [as log(number of CFU/milliliter)] was calculated after manufacturer-determined contact times along with biofilm biomass and microscopy. The primary analysis compared differences between C. difficile vegetative cell and spore counts as well as amounts of biomass after exposure to disinfectants. C. difficile vegetative cells and spores were recovered from biofilms regardless of the type of biofilm growth or biofilm growth time. No disinfectant was able to completely eliminate C. difficile from the biofilms. Overall, Clorox, ortho-phthalaldehyde (OPA), and Virex were most effective at killing C. difficile spores regardless of biofilm age, ribotype, or wash conditions (whether biofilms are washed or unwashed) (P = 0.001, each). Clorox and OPA were also effective at killing total vegetative cell growth (P = 0.001, each), but Virex was found to be ineffective against vegetative cell growth in biofilms (P = 0.77). Clorox and Virex were most effective in reducing biomass, followed by Nixall, OPA, and Vital Oxide. No disinfectant was able to completely eliminate C. difficile embedded within biofilms although differences among disinfectants were noted. Future research will be required to determine methods to eradicate this persister reservoir.

Production of Bacillus amyloliquefaciens OG and its metabolites in renewable media: valorisation for biodiesel production and p-xylene decontamination.

Biosurfactants are important in many areas; however, costs impede large-scale production. This work aimed to develop a global sustainable strategy for the production of biosurfactants by a novel strain of Bacillus amyloliquefaciens. Initially, Bacillus sp. strain 0G was renamed B. amyloliquefaciens subsp. plantarum (syn. Bacillus velezensis) after analysis of the gyrA and gyrB DNA sequences. Growth in modified Landy's medium produced 3 main recoverable metabolites: surfactin, fengycin, and acetoin, which promote plant growth. Cultivation was studied in the presence of renewable carbon (as glycerol) and nitrogen (as arginine) sources. While diverse kinetics of acetoin production were observed in different media, similar yields (6-8 g·L-1) were obtained after 72 h of growth. Glycerol increased surfactin-specific production, while arginine increased the yields of surfactin and fengycin and increased biomass significantly. The specific production of fengycin increased ∼10 times, possibly due to a connecting pathway involving arginine and ornithine. Adding value to crude extracts and biomass, both were shown to be useful, respectively, for the removal of p-xylene from contaminated water and for biodiesel production, yielding ∼70 mg·g-1 cells and glycerol, which could be recycled in novel media. This is the first study considering circular bioeconomy to lower the production costs of biosurfactants by valorisation of both microbial cells and their primary and secondary metabolites.

Ultraviolet (UV)-reflective paint with ultraviolet germicidal irradiation (UVGI) improves decontamination of nosocomial bacteria on hospital room surfaces.

An ultraviolet germicidal irradiation (UVGI) generator (the TORCH, ClorDiSys Solutions, Inc.) was used to compare the disinfection of surface coupons (plastic from a bedrail, stainless steel, and chrome-plated light switch cover) in a hospital room with walls coated with ultraviolet (UV)-reflective paint (Lumacept) or standard paint. Each surface coupon was inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus faecalis (VRE), placed at 6 different sites within a hospital room coated with UV-reflective paint or standard paint, and treated by 10 min UVC exposure (UVC dose of 0-688 mJ/cm2 between sites with standard paint and 0-553 mJ/cm2 with UV-reflective paint) in 8 total trials. Aggregated MRSA concentrations on plastic bedrail surface coupons were reduced on average by 3.0 log10 (1.8 log10 Geometric Standard Deviation [GSD]) with standard paint and 4.3 log10 (1.3 log10 GSD) with UV-reflective paint (p = 0.0005) with no significant reduction differences between paints on stainless steel and chrome. Average VRE concentrations were reduced by ≥4.9 log10 (<1.2 log10 GSD) on all surface types with UV-reflective paint and ≤4.1 log10 (<1.7 log10 GSD) with standard paint (p < 0.05). At 5 aggregated sites directly exposed to UVC light, MRSA concentrations on average were reduced by 5.2 log10 (1.4 log10 GSD) with standard paint and 5.1 log10 (1.2 log10 GSD) with UV-reflective paint (p = 0.017) and VRE by 4.4 log10 (1.4 log10 GSD) with standard paint and 5.3 log10 (1.1 log10 GSD) with UV-reflective paint (p < 0.0001). At one indirectly exposed site on the opposite side of the hospital bed from the UVGI generator, MRSA concentrations on average were reduced by 1.3 log10 (1.7 log10 GSD) with standard paint and 4.7 log10 (1.3 log10 GSD) with UV-reflective paint (p < 0.0001) and VRE by 1.2 log10 (1.5 log10 GSD) with standard paint and 4.6 log10 (1.1 log10 GSD) with UV-reflective paint (p < 0.0001). Coating hospital room walls with UV-reflective paint enhanced UVGI disinfection of nosocomial bacteria on various surfaces compared to standard paint, particularly at a surface placement site indirectly exposed to UVC light.

Mutagenicity of cigarette butt waste in the bacterial reverse mutation assay: The protective effects of ß-caryophyllene and ß-caryophyllene oxide.

Cigarette filters pose a serious litter and toxic waste disposal problem, because of their not biodegradability and to the leaching of toxins in the environment. Therefore, cigarette butts need to be manipulated as special waste, with potential risks to human health and environment. In the present study, the genotoxic potential of a methanol extract from commonly discharged cigarette butts (CBE) was evaluated in the bacterial reverse mutation assay on Salmonella typhimurium TA98 and TA100 and Escherichia coli WP2uvrA strains, both in the absence and presence of the S9 exogenous metabolic activator. Furthermore, the ability of the natural sesquiterpenes ß-caryophyllene (CRY) and ß-caryophyllene oxide (CRYO) to inhibit the mutagenicity of CBE was studied as a possible preventive strategy. In order to identify the potential antimutagenic mechanisms, three different protocols (pretreatment, cotreatment, and posttreatment) were applied. CBE showed to increase the number of revertant colonies in all the strains tested in presence of S9, so resulting mutagenic. In the antimutagenicity assay, both CRY and CRYO significantly reduced the revertant colonies induced by CBE, although with different potency and specificity. For both sesquiterpenes, the antimutagenicity was strong in all experimental conditions, except for the cotreatment of CRY with CBE in WP2uvrA, which produced a moderate inhibition. Both desmutagenic and bioantimutagenic mechanisms seem to be involved in the antimutagenicity of the test substances. Taking into account the potential genotoxicity of cigarette butts, CRY and CRYO appear as possible further candidates as environmental decontaminants against this hazardous waste. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1319-1328, 2016.

Sensitivity and antioxidant response of forest species seedlings to the atrazine under simulated conditions of subsurface water contamination.

Atrazine is an herbicide with a high soil leaching capacity, contaminating subsurface water sources. Once the water table is contaminated, riparian species can be exposed to atrazine. In this way, understanding the impacts of this exposure must be evaluated for planning strategies that minimize the effects of this herbicide on native forest species. We aimed to evaluate forest species' sensitivity and antioxidant response to exposure to subsurface waters contaminated with atrazine, as well the dissipation this herbicide. The experiment was conducted in a greenhouse in a completely randomized design, with three replications and one plant per experimental unit. The treatments were arranged in a 2 × 10 factorial. The first factor corresponded to the presence or absence (control) of the atrazine in the subsurface water. The second factor comprised 10 forest species: Amburana cearensis, Anadenanthera macrocarpa, Bauhinia cheilantha, Enterolobium contortisiliquum, Hymenaea courbaril, Libidibia ferrea, Mimosa caesalpiniifolia, Mimosa tenuiflora, Myracrodruon urundeuva, and Tabebuia aurea. The forest species studied showed different sensitivity levels to atrazine in subsurface water. A. cearensis and B. cheilantha species do not have efficient antioxidant systems to prevent severe oxidative damage. The species A. macrocarpa, E. contortisiliquum, L. ferrea, and M. caesalpiniifolia are moderately affected by atrazine. H. courbaril, M. urundeuva, and T. aurea showed greater tolerance to atrazine due to the action of the antioxidant system of these species, avoiding membrane degradation events linked to the production of reactive oxygen species (ROS). Among the forest species, H. courbaril has the most significant remedial potential due to its greater tolerance and reduced atrazine concentrations in the soil.

Perspectives for Photocatalytic Decomposition of Environmental Pollutants on Photoactive Particles of Soil Minerals.

The literature shows that both in laboratory and in industrial conditions, the photocatalytic oxidation method copes quite well with degradation of most environmental toxins and pathogenic microorganisms. However, the effective utilization of photocatalytic processes for environmental decontamination and disinfection requires significant technological advancement in both the area of semiconductor material synthesis and its application. Here, we focused on the presence and "photocatalytic capability" of photocatalysts among soil minerals and their potential contributions to the environmental decontamination in vitro and in vivo. Reactions caused by sunlight on the soil surface are involved in its normal redox activity, taking part also in the soil decontamination. However, their importance for decontamination in vivo cannot be overstated, due to the diversity of soils on the Earth, which is caused by the environmental conditions, such as climate, parent material, relief, vegetation, etc. The sunlight-induced reactions are just a part of complicated soil chemistry processes dependent on a plethora of environmental determinates. The multiplicity of affecting factors, which we tried to sketch from the perspective of chemists and environmental scientists, makes us rather skeptical about the effectiveness of the photocatalytic decontamination in vivo. On the other hand, there is a huge potential of the soils as the alternative and probably cheaper source of useful photocatalytic materials of unique properties. In our opinion, establishing collaboration between experts from different disciplines is the most crucial opportunity, as well as a challenge, for the advancement of photocatalysis.

The Antibacterial Efficacy of Far-UVC Light: A Combined-Method Study Exploring the Effects of Experimental and Bacterial Variables on Dose-Response.

Far-ultraviolet C light, with a wavelength of 200-230 nm, has demonstrated broad-spectrum germicidal efficacy. However, due to increased interest in its use as an alternative antimicrobial, further knowledge about its fundamental bactericidal efficacy is required. This study had two objectives. Firstly, it investigated experimentally the Far-UVC dose-response of common bacteria suspended at various cell densities in transparent buffer, ensuring no influence from photosensitive suspending media. Increasing doses of Far-UVC were delivered to Enterococcus faecium, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus in PBS at 101, 102, 103, 105 and 107 CFU·mL-1, with surviving colony-forming units enumerated (n ≥ 3). Secondly, through a systematised literature review, this work sought to explore the impact of genus/species, Gram type, cell form, cell density and irradiance on dose-response. The screening of 483 publications was performed with 25 included in the study. Data for 30 species were collated, analysed and compared with the experimental results. Overall, Gram-positive species showed greater resilience to Far-UVC than Gram-negative; some inter-species and inter-genera differences in resilience were identified; endospores were more resilient than vegetative cells; the results suggested that inactivation efficiency may decrease as cell density increases; and no significant correlation was identified between irradiance and bactericidal dose effect. In conclusion, this study has shown Far-UVC light to be an effective decontamination tool against a vast range of bacterial vegetative cells and endospores.

Laboratory evaluation of the broad-spectrum antibacterial efficacy of a low-irradiance visible 405-nm light system for surface-simulated decontamination.

Purpose: Lighting systems which use visible light blended with antimicrobial 405-nm violet-blue light have recently been developed for safe continuous decontamination of occupied healthcare environments. This paper characterises the optical output and antibacterial efficacy of a low irradiance 405-nm light system designed for environmental decontamination applications, under controlled laboratory conditions. Methods: In the current study, the irradiance output of a ceiling-mounted 405-nm light source was profiled within a 3×3×2 m (18 m3) test area; with values ranging from 0.001-2.016 mWcm-2. To evaluate antibacterial efficacy of the light source for environmental surface decontamination, irradiance levels within this range (0.021-1 mWcm-2) at various angular (Δ Ï´=0-51.3) and linear (∆s=1.6-2.56 m) displacements from the source were used to generate inactivation kinetics, using the model organism, Staphylococcus aureus. Additionally, twelve bacterial species were surface-seeded and light-exposed at a fixed displacement below the source (1.5 m; 0.5 mWcm-2) to demonstrate broad-spectrum efficacy at heights typical of high touch surfaces within occupied settings. Results: Results demonstrate that significant (P≤0.05) inactivation was successfully achieved at all irradiance values investigated, with spatial positioning from the source affecting inactivation, with greater times required for inactivation as irradiance decreased. Complete/near-complete (≥93.28%) inactivation of all bacteria was achieved following exposure to 0.5 mWcm-2 within exposure times realistic of those utilised practically for whole-room decontamination (2-16 h). Conclusion: This study provides fundamental evidence of the efficacy, and energy efficiency, of low irradiance 405-nm light for bacterial inactivation within a controlled laboratory setting, further justifying its benefits for practical infection control applications.

TET-Yeasate: An engineered yeast whole-cell lysate-based approach for high performance tetracycline degradation.

The widespread of tetracycline (TC) residues in anthropogenic and natural environments pose an immediate threat to public health. Herein, we established the TET-Yeasate, an approach based on whole-cell lysate of engineered yeast, to mitigate the TC contamination in environment. The TET-Yeasate is defined as the biological matrix of whole cell lysate from engineered yeast that containing TC-degradative components (Tet(X), NADPH, Mg2+) and protective macromolecules. The TET-Yeasate was able to efficiently eliminate TC residues in tap water (98.8%), lake water (77.6%), livestock sewage (87.3%) and pharmaceutical wastewater (35.3%) without necessity for exogenous addition of expensive cofactors. The TET-Yeasate was further developed into lyophilized form for ease of storage and delivery. The TET-Yeasate in lyophilized form efficiently removed up to 74.6% TC residue within 0.25 h. In addition, the lyophilization confers promising resilience to TET-Yeasate against adverse temperatures and pH by maintaining degradation efficacy of 85.69%-97.83%. The stability test demonstrated that the biomacromolecules in lysate served as natural protectants that exerted extensive protection on TET-Yeasate during the 14-day storage at various conditions. In addition, 5 potential degradation pathways were elaborated based on the intermediate products. Finally, the analysis indicated that TET-Yeasate enjoyed desirable bio- and eco-safety without introduction of hazardous intermediates and spread of resistance genes. To summary, the TET-Yeasate based on whole cell lysate of engineered yeast provides a cost-effective and safe alternative to efficiently remove TC residues in environment, highlighting the great potential of such whole-cell based methods in environmental decontamination.

Strategies to Prevent Transmission of Candida auris in Healthcare Settings.

Purpose of Review: Candida auris, a recently recognized yeast pathogen, has become a major public health threat due to the problems associated with its accurate identification, intrinsic and acquired resistance to antifungal drugs, and its potential to easily contaminate the environment causing clonal outbreaks in healthcare facilities. These outbreaks are associated with high mortality rates particularly among older patients with multiple comorbidities under intensive care settings. The purpose of this review is to highlight strategies that are being adapted to prevent transmission of C. auris in healthcare settings. Recent Findings: Colonized patients shed C. auris into their environment which contaminates surrounding equipment. It resists elimination even by robust decontamination procedures and is easily transmitted to new patients during close contact resulting in outbreaks. Efforts are being made to rapidly identify C. auris-infected/C. auris-colonized patients, to determine its susceptibility to antifungals, and to perform effective cleaning and decontamination of the environment and isolation of colonized patients to prevent further transmission. Summary: Rapid and accurate identification of hospitalized patients infected/colonized with C. auris, rapid detection of its susceptibility patterns, and appropriate use of infection control measures can help to contain the spread of this highly pathogenic yeast in healthcare settings and prevent/control outbreaks.

Evaluation of an aerosolized hydrogen peroxide disinfection system for the reduction of Clostridioides difficile hospital infection rates over a 10 year period.

BACKGROUND: Clostridioides difficile infections (CDI) cause significant morbidity and mortality in healthcare facilities worldwide. We examined the use of an aerosolized hydrogen peroxide (aHP) disinfection system for reduction of CDI rates. METHODS: We conducted a retrospective analysis of CDI rates at an acute care facility over a 10-year period. The first 5-year period investigated the before and after implementation of an aHP system followed by another 5-year period of continued use on CDI rates. RESULTS: The before and after period showed a reduction in CDI rates from 4.6 per 10,000 patient days down to 2.7 per 10,000 patient days after implementation (P < .001). The second study period for the continued aHP use exhibited a consistent decrease in CDI rates to 1.4 per 10,000 patient days at the end of the study. CONCLUSIONS: The addition of a touchless aHP whole room disinfection system as part of terminal cleaning resulted in a significant reduction in CDI rates that have been sustained year after year.

Evaluation of a bipolar ionization device in inactivation of antimicrobial-resistant bacteria, yeast, Aspergillus spp. and human coronavirus.

BACKGROUND: The efficacy of bipolar ionization in the healthcare setting has yet to be proven. A major limitation of studies sponsored by industry has been the assessment of efficiency within test chambers in which ozone levels are not adequately controlled. AIM: To assess the effectiveness of bipolar ionization against antimicrobial-resistant bacteria, fungi and human coronavirus within a controlled test chamber designed to mitigate the effect of ozone. METHODS: Bacteria- and fungi-inoculated gauze pads, and human coronavirus 229E-inoculated stainless steel plates were placed within the vicinity of the AIO-2 bipolar ionizer and left at room temperature (2 h for coronavirus and 4 h for bacteria and fungi). FINDINGS: Four hours of exposure to bipolar ionization showed a 1.23-4.76 log reduction, corresponding to a 94.2->99.9% colony-forming units/gauze reduction, in Clostridioides difficile, Klebsiella pneumoniae carbapenemase-producing K. pneumoniae, meticillin-resistant Staphylococcus aureus and multi-drug-resistant S. aureus. A 1.2 log 50% tissue culture infectious dose reduction in human coronavirus was observed after 2 h. CONCLUSION: The assessment of bipolar ionization systems merits further investigation as an infection control measure.

Candida auris: Epidemiology, Diagnosis, Pathogenesis, Antifungal Susceptibility, and Infection Control Measures to Combat the Spread of Infections in Healthcare Facilities.

Candida auris, a recently recognized, often multidrug-resistant yeast, has become a significant fungal pathogen due to its ability to cause invasive infections and outbreaks in healthcare facilities which have been difficult to control and treat. The extraordinary abilities of C. auris to easily contaminate the environment around colonized patients and persist for long periods have recently resulted in major outbreaks in many countries. C. auris resists elimination by robust cleaning and other decontamination procedures, likely due to the formation of 'dry' biofilms. Susceptible hospitalized patients, particularly those with multiple comorbidities in intensive care settings, acquire C. auris rather easily from close contact with C. auris-infected patients, their environment, or the equipment used on colonized patients, often with fatal consequences. This review highlights the lessons learned from recent studies on the epidemiology, diagnosis, pathogenesis, susceptibility, and molecular basis of resistance to antifungal drugs and infection control measures to combat the spread of C. auris infections in healthcare facilities. Particular emphasis is given to interventions aiming to prevent new infections in healthcare facilities, including the screening of susceptible patients for colonization; the cleaning and decontamination of the environment, equipment, and colonized patients; and successful approaches to identify and treat infected patients, particularly during outbreaks.

Prevention of Infection due to Clostridium (Clostridioides) difficile.

Clostridium (Clostridioides) difficile infection (CDI) causes significant morbidity and mortality in the United States every year. Prevention of CDI is difficult because of spore durability and requires implementation of multipronged strategies. Two categories of prevention strategies are infection control and prevention and risk factor reduction. Hand hygiene, contact precautions, patient isolation, and environmental decontamination are cornerstones of infection control and prevention. Risk factor reduction should focus on antibiotic stewardship to reduce unnecessary antibiotic use. If CDI incidence remains higher than the institution's goal despite these measures, then special measures should be considered.

Structural-Phase Catalytic Redox Reactions in Energy and Environmental Applications.

The structure-property engineering of phase-based materials for redox-reactive energy conversion and environmental decontamination nanosystems, which are crucial for achieving feasible and sustainable energy and environment treatment technology, is discussed. An exhaustive overview of redox reaction processes, including electrocatalysis, photocatalysis, and photoelectrocatalysis, is given. Through examples of applications of these redox reactions, how structural phase engineering (SPE) strategies can influence the catalytic activity, selectivity, and stability is constructively reviewed and discussed. As observed, to date, much progress has been made in SPE to improve catalytic redox reactions. However, a number of highly intriguing, unresolved issues remain to be discussed, including solar photon-to-exciton conversion efficiency, exciton dissociation into active reductive/oxidative electrons/holes, dual- and multiphase junctions, selective adsorption/desorption, performance stability, sustainability, etc. To conclude, key challenges and prospects with SPE-assisted redox reaction systems are highlighted, where further development for the advanced engineering of phase-based materials will accelerate the sustainable (active, reliable, and scalable) production of valuable chemicals and energy, as well as facilitate environmental treatment.

Norovirus recovery from floors and air after various decontamination protocols.

BACKGROUND: The dispersal of airborne norovirus (NoV) particles from the floor after contamination with faeces or vomit is a challenge for infection control, as this pathogen is infectious at low doses. Therefore, it is imperative to establish a safe protocol for floor decontamination. AIM: To assess the presence of residual NoV-GII particles on floors and airborne particles following various floor decontamination procedures. METHODS: Two types of floor (vinyl and granite) were contaminated intentionally with 10% human faeces, positive for NoV-GII. Two decontamination protocols were implemented: cleaning followed by disinfection using 1% sodium hypochlorite, and cleaning followed by disinfection using a manual ultraviolet C (UV-C) light device. Swab samples were taken from the floors, and air samples were obtained using an air sampler. The TaqMan method for real-time reverse transcription-quantitative polymerase chain reaction was employed for analysis. FINDINGS: The disinfection protocol using 1% sodium hypochlorite after cleaning proved to be more effective than cleaning followed by UV-C light exposure (P<0.001). Viral particles were detected in 27 of 36 air samples after cleaning, with no significant difference between the two floor types. On average, 617 genome copies/sample were identified in air samples after cleaning, but the number decreased gradually after disinfection. CONCLUSION: NoV-GII can be aerosolized during floor cleaning, and its particles may be inhaled and then swallowed or can settle on surfaces. Therefore, residual viral particles on floors must be fully eliminated. Cleaning followed by 10 min of 1% sodium hypochlorite disinfection proved to be the superior decontamination protocol.

Surface microbial contamination in a dental department. A 10-year retrospective analysis

Health care-associated infections may not only occur in a hospital setting, but also in dental clinics. Insufficient environmental decontamination could be one of the risk factors. In this retrospective study, we documented and analyzed the results of surface microbial contamination in a dental university-based department over an observation period of ten years. It was the aim of this investigation to identify general tendencies and potentially problematic sites on a long-term basis allowing suggestions for further improvement. Surface microbial contamination in the Department of Reconstructive Dentistry at the University Center for Dental Medicine in Basel, Switzerland, was evaluated on a regular basis using contact plates. Data gained between January 2007 and December 2016 was collected and summarized for statistical analysis. Although the overall surface microbial contamination was relatively low during the observation period, significant differences depending on localization and test sites were detected. Certain sites, such as the handle of the dentist's chair and computer surfaces, remained problematic. Continuous monitoring of surface microbial contamination can help to improve the hygiene level in a dental set-up. Further improvement might be achieved by avoiding hand-touch handles whenever possible and by relying on flat and easy-to-clean surfaces within the reach of the bacterial aerosol. However, during interventions that may pose a higher risk for the patient, additional measures should be taken by working under almost sterile conditions and by avoiding direct hand contact with problematic sites.

The efficacy of self-disinfecting bedrail covers in an intensive care unit.

BACKGROUND: Hospital surfaces are considered important vectors in the spread of nosocomial pathogens. This study evaluated microbial counts on novel antimicrobial bedrail covers over a 2-week period in a critical care environment. METHODS: Disposable bedrail covers (Aionx Inc, Hershey, PA) made of a copper and silver polymer and capable of conducting an imperceptible surface potential, were installed in a case-control manner on a series of occupied intensive care unit beds. Seventeen bedrails were covered with the study bedrail surface, and 17 were left uncovered. Two hundred seventy-two microbial surface cultures were obtained from both study and control bedrails and analyzed for microbial growth by bacterial enumeration and speciation. RESULTS: The bedrails covered with the study surface demonstrated >80% average decrease in colony forming units across the study period of 15 days. CONCLUSIONS: These novel, detachable bedrail covers successfully demonstrated significant bacterial count reduction in an intensive care unit setting. This may have implications for acquisition of hospital-acquired infections.