Evaluation of electrostatic sprayers and foggers for the application of disinfectants in the era of SARS-CoV-2

Although research has shown that the COVID-19 disease is most likely caused by airborne transmission of the SARS-CoV-2 virus, disinfection of potentially contaminated surfaces is also recommended to limit the spread of the disease. Use of electrostatic sprayers (ESS) and foggers to rapidly apply disinfectants over large areas or to complex surfaces has emerged with the COVID-19 pandemic. ESSs are designed to impart an electrostatic charge to the spray droplets with the goal of increasing deposition of the droplets onto surfaces, thereby promoting more efficient use of the disinfectant. The purpose of this research was to evaluate several spray parameters for different types of sprayers and foggers, as they relate to the application of disinfectants. Some of the parameters evaluated included the spray droplet size distribution, the electrostatic charge, the ability of the spray to wrap around objects, and the loss of disinfectant chemical active ingredient due to the spray process. The results show that most of the devices evaluated for droplet size distribution had an average volume median diameter ≥ 40 microns, and that four out of the six ESS tested for charge/mass produced sprays of at least 0.1 mC/kg. A minimal wrap-around effect of the spray deposition onto a cylindrical object was observed. The loss of disinfectant active ingredient to the air due to spraying was minimal for the two disinfectants tested, and concurrently, the active ingredient concentrations of the liquid disinfectants sprayed and collected 3 feet (1 meter) away from the spray nozzle do not decrease.

Biologia Futura: use of biocides during COVID-19-global reshuffling of the microbiota

Aim The article reviews the current usage of biocides during this lockdown period for sanitizing our living areas due to the pandemic and discusses the pros and cons. Subject COVID-19 spread like wildfire to over 200 countries of the world across all continents. The causative agent, novel coronavirus (SARS-CoV-2) is being counter attacked by a thorough application of disinfectants and sterilants. However, the virus mutated over 30 times during this global pandemic, creating panic and leading to enhanced pathogenicity and consequently to more stringent sanitation measures for controlling it. However, excessive use of different types of biocides for disinfecting surfaces is highly alarming in several cases. Extensive application of biocides affects the microbial flora, leading to an abrupt decrease in the number and diversity of beneficial microbes that may directly affect the functioning of nutrient cycles. Results The increased concentration of biocides in agricultural land via surface water or pond water indirectly affect the soil and water ecosystem, soil aggregation and fertility. This will also lead to the flourishing of resistant strains due to loss of competition from the other species, which fail to persist after prolonged use of biocides. Conclusion It is necessary to realize the environmental impacts of biocides and sterilants. It is the right time to stop their entry into the agricultural ecosystem by following adequate management strategies and complete neutralization.

Humidifier disinfectant, sodium dichloroisocyanurate (NaDCC): assessment of respiratory effects to protect workers' health

In South Korea, it has been found that biocides used to control and eliminate harmful organisms are used as humidifier disinfectants and cause lung disease in users. Hence, efforts have been focused on studying the toxicity of biocides in workers who handle them. The purpose of this study was to evaluate the effects of inhalation exposure to sodium dichloroisocyanurate (NaDCC) to protect the health of workers handling NaDCC. F344 rats were exposed to 0.8-, 4-, and 20-mg/m3 of NaDCC for 6 h per day, 5 days per week for 14 days, and the recovery period after exposure was 14 days. In the 20-mg/m3-exposure group, we observed a decrease in food intake in females, a weight loss in males, and a decrease in partially active thromboplastin time in males and females 2 weeks after exposure. We noted a decrease in white blood cells in males in the 4- and 20-mg/m3-exposed groups. Both males and females in the 20-mg/m3 group and males in the 4-mg/m3 group showed irritation in the larynx related to test substance exposure. However, these findings were not observed in the recovery group. The main target organs affected by repeated 2-week inhalation exposure to NaDCC were the nasal cavity and larynx in the upper respiratory tract. The No Observed Adverse Effect Level (NOAEL) was considered to be 0.8 mg/m3 because effects related to NaDCC exposure were observed even at of 4 mg/m3, and these effects were found to be reversible.

Scalable in-hospital decontamination of N95 filtering face-piece respirator with a peracetic acid room disinfection system

BACKGROUND

Critical shortages of personal protective equipment, especially N95 respirators, during the coronavirus disease 2019 (COVID-19) pandemic continues to be a source of concern. Novel methods of N95 filtering face-piece respirator decontamination that can be scaled-up for in-hospital use can help address this concern and keep healthcare workers (HCWs) safe.

METHODS

A multidisciplinary pragmatic study was conducted to evaluate the use of an ultrasonic room high-level disinfection system (HLDS) that generates aerosolized peracetic acid (PAA) and hydrogen peroxide for decontamination of large numbers of N95 respirators. A cycle duration that consistently achieved disinfection of N95 respirators (defined as ≥6 log10 reductions in bacteriophage MS2 and Geobacillus stearothermophilus spores inoculated onto respirators) was identified. The treated masks were assessed for changes to their hydrophobicity, material structure, strap elasticity, and filtration efficiency. PAA and hydrogen peroxide off-gassing from treated masks were also assessed.

RESULTS

The PAA room HLDS was effective for disinfection of bacteriophage MS2 and G. stearothermophilus spores on respirators in a 2,447 cubic-foot (69.6 cubic-meter) room with an aerosol deployment time of 16 minutes and a dwell time of 32 minutes. The total cycle time was 1 hour and 16 minutes. After 5 treatment cycles, no adverse effects were detected on filtration efficiency, structural integrity, or strap elasticity. There was no detectable off-gassing of PAA and hydrogen peroxide from the treated masks at 20 and 60 minutes after the disinfection cycle, respectively.

CONCLUSION

The PAA room disinfection system provides a rapidly scalable solution for in-hospital decontamination of large numbers of N95 respirators during the COVID-19 pandemic.

Scalable in-hospital decontamination of N95 filtering face-piece respirator with a peracetic acid room disinfection system

BACKGROUND

Critical shortages of personal protective equipment, especially N95 respirators, during the coronavirus disease 2019 (COVID-19) pandemic continues to be a source of concern. Novel methods of N95 filtering face-piece respirator decontamination that can be scaled-up for in-hospital use can help address this concern and keep healthcare workers (HCWs) safe.

METHODS

A multidisciplinary pragmatic study was conducted to evaluate the use of an ultrasonic room high-level disinfection system (HLDS) that generates aerosolized peracetic acid (PAA) and hydrogen peroxide for decontamination of large numbers of N95 respirators. A cycle duration that consistently achieved disinfection of N95 respirators (defined as ≥6 log10 reductions in bacteriophage MS2 and Geobacillus stearothermophilus spores inoculated onto respirators) was identified. The treated masks were assessed for changes to their hydrophobicity, material structure, strap elasticity, and filtration efficiency. PAA and hydrogen peroxide off-gassing from treated masks were also assessed.

RESULTS

The PAA room HLDS was effective for disinfection of bacteriophage MS2 and G. stearothermophilus spores on respirators in a 2,447 cubic-foot (69.6 cubic-meter) room with an aerosol deployment time of 16 minutes and a dwell time of 32 minutes. The total cycle time was 1 hour and 16 minutes. After 5 treatment cycles, no adverse effects were detected on filtration efficiency, structural integrity, or strap elasticity. There was no detectable off-gassing of PAA and hydrogen peroxide from the treated masks at 20 and 60 minutes after the disinfection cycle, respectively.

CONCLUSION

The PAA room disinfection system provides a rapidly scalable solution for in-hospital decontamination of large numbers of N95 respirators during the COVID-19 pandemic.

Promotion of Surgical Masks Antimicrobial Activity by Disinfection and Impregnation with Disinfectant Silver Nanoparticles

BACKGROUND

The COVID-19 pandemic is requesting highly effective protective personnel equipment, mainly for healthcare professionals. However, the current demand has exceeded the supply chain and, consequently, shortage of essential medical materials, such as surgical masks. Due to these alarming limitations, it is crucial to develop effective means of disinfection, reusing, and thereby applying antimicrobial shielding protection to the clinical supplies.

PURPOSE

Therefore, in this work, we developed a novel, economical, and straightforward approach to promote antimicrobial activity to surgical masks by impregnating silver nanoparticles (AgNPs).

METHODS

Our strategy consisted of fabricating a new alcohol disinfectant formulation combining special surfactants and AgNPs, which is demonstrated to be extensively effective against a broad number of microbial surrogates of SARS-CoV-2.

RESULTS

The present nano-formula reported a superior microbial reduction of 99.999% against a wide number of microorganisms. Furthermore, the enveloped H5N1 virus was wholly inactivated after 15 min of disinfection. Far more attractive, the current method for reusing surgical masks did not show outcomes of detrimental amendments, suggesting that the protocol does not alter the filtration effectiveness.

CONCLUSION

The nano-disinfectant provides a valuable strategy for effective decontamination, reuse, and even antimicrobial promotion to surgical masks for frontline clinical personnel.

Does washing medical devices before and after use decrease bacterial contamination?: An in vitro study

ABSTRACT

Surface treatment of medical devices may be a way of avoiding the need for replacement of these devices and the comorbidities associated with infection. The aim of this study was to evaluate whether pre- and postcontamination washing of 2 prostheses with different textures can decrease bacterial contamination.The following microorganisms were evaluated: Staphylococcus aureus, Staphylococcus epidermidis, Proteus mirabilis and Enterococcus faecalis. Silicone and expanded polytetrafluoroethylene vascular prostheses were used and divided into 3 groups: prostheses contaminated; prostheses contaminated and treated before contamination; and prostheses contaminated and treated after contamination. Treatments were performed with antibiotic solution, chlorhexidine and lidocaine. After one week of incubation, the prostheses were sown in culture medium, which was incubated for 48 hours. The area of colony formation was evaluated by fractal dimension, an image analysis tool.The antibiotic solution inhibited the growth of S epidermidis and chlorhexidine decrease in 53% the colonization density for S aureus in for both prostheses in the pre-washing. In postcontamination washing, the antibiotic solution inhibited the growth of all bacteria evaluated; there was a 60% decrease in the colonization density of S aureus and absence of colonization for E faecalis with chlorhexidine; and lidocaine inhibited the growth of S aureus in both prostheses.Antibiotic solution showed the highest efficiency in inhibiting bacterial growth, especially for S epidermidis, in both washings. Lidocaine was able to reduce colonization by S aureus in post-contamination washing, showing that it can be used as an alternative adjuvant treatment in these cases.

Is skin disinfection before subcutaneous injection necessary? The reasoning of Certified Nurses in Infection Control in Japan

Nurses continue to disinfect the skin before administering subcutaneous injections as a standard process in clinical settings; despite evidence that disinfection is not necessary. To implement evidence-based practice, it is critical to explore why this gap between "evidence" and "practice" exists. This study aimed to describe the reasons offered by Certified Nurses in Infection Control (CNIC) in Japan for performing skin disinfection before subcutaneous injection. Adopting an inductive qualitative design, interviews were conducted with 10 CNIC in 2013. According to the participants, skin disinfection before subcutaneous injection: (a) was common practice; (b) may have been beneficial if it was omitted; (c) adhered to hospital norms; (d) prevented persistent suspicion of infection; (e) had no detrimental effect; (f) was an ingrained custom; and (g) involved a tacit approval for not disinfecting in home care settings. The themes (c) and (g) were cited as the main reasons affecting decision-making. The CNIC administered injections following skin disinfection in hospitals in accordance with hospital norms. On the contrary, outside the hospital, they administered subcutaneous injections without skin disinfection. All themes except (b) and (g) reflect the barriers and resistance to omitting skin disinfection, while (g) shows that it is already partly implemented in home care settings. It is necessary to create a guideline for skin disinfection before subcutaneous injection that considers the quality of life of patients at home, their physical conditions, and the surrounding environment at the time of injection, in addition to the guidelines applicable in hospitals.

Effect of potassium iodide supplementation and teat-dipping on iodine status in dairy cows and milk iodine levels

Two experiments were designed to determine the effects of dietary iodine and teat-dipping on the iodine status of dairy cows and their milk. Eight mid-lactation Holstein dairy cows with an initial body weight of 642 ± 62 kg and 145 ± 21 d in milk were studied for 2 periods over 44 d. In period 1, all cows were fed a basal diet supplemented with potassium iodide (KI) (10 mg I/Kg DM) for 8 d with no teat-dipping. In period 2, a pre-milking teat-dipping was applied for 10 d followed by no teat-dipping before milking (udder wash without iodine) and then post-dipping treatment was applied for 5 d. Feeding KI increased concentrations of iodine in serum, urine, and milk (P < 0.05). Switching from the KI supplementation to no iodine addition resulted in an immediate decrease of iodine in serum, urine, and milk (P < 0.05). Post teat-dipping resulted in increased iodine levels in serum, urine, and milk (P < 0.05). However, pre-milking teat-dipping did not affect iodine concentration compared to post-dipping. A 250 mL cup of milk from the control and KI-supplemented diets would provide 29.4% and 68.4%, respectively, of the adult-recommended dietary allowance for iodine. In conclusion, milk iodine concentration could be effectively enhanced by KI supplementation and teat-dipping practices.

Efficacy and safety of disinfectants for decontamination of N95 and SN95 filtering facepiece respirators: a systematic review

BACKGROUND

Decontaminating and reusing filtering facepiece respirators (FFRs) for healthcare workers is a potential solution to address inadequate FFR supply during a global pandemic.

AIM

The objective of this review was to synthesize existing data on the effectiveness and safety of using chemical disinfectants to decontaminate N95 FFRs.

METHODS

A systematic review was conducted on disinfectants to decontaminate N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO feed, and MedRxiv. Two reviewers independently determined study eligibility and extracted predefined data fields. Original research reporting on N95 FFR function, decontamination, safety, or FFR fit following decontamination with a disinfectant was included.

FINDINGS AND CONCLUSION

A single cycle of vaporized hydrogen peroxide (H₂O₂) successfully removes viral pathogens without affecting airflow resistance or fit, and maintains an initial filter penetration of <5%, with little change in FFR appearance. Residual hydrogen peroxide levels following decontamination were within safe limits. More than one decontamination cycle of vaporized H₂O₂ may be possible but further information is required on how multiple cycles would affect FFR fit in a real-world setting before the upper limit can be established. Although immersion in liquid H₂O₂ does not appear to adversely affect FFR function, there is no available data on its ability to remove infectious pathogens from FFRs or its impact on FFR fit. Sodium hypochlorite, ethanol, isopropyl alcohol, and ethylene oxide are not recommended due to safety concerns or negative effects on FFR function.

Evaluation of an electrostatic spray disinfectant technology for rapid decontamination of portable equipment and large open areas in the era of SARS-CoV-2

In the setting of the coronavirus disease 2019 pandemic, efficient methods are needed to decontaminate shared portable devices and large open areas such as waiting rooms. We found that wheelchairs, portable equipment, and waiting room chairs were frequently contaminated with potential pathogens. After minimal manual precleaning of areas with visible soiling, application of a dilute sodium hypochlorite disinfectant using an electrostatic sprayer provided rapid and effective decontamination and eliminated the benign virus bacteriophage MS2 from inoculated surfaces.

Short- and Long-Term Transcriptomic Responses of Escherichia coli to Biocides: a Systems Analysis

The mechanisms of the bacterial response to biocides are poorly understood, despite their broad application. To identify the genetic basis and pathways implicated in the biocide stress response, we exposed Escherichia coli populations to 10 ubiquitous biocides. By comparing the transcriptional responses between a short-term exposure (30 min) and a long-term exposure (8 to 12 h) to biocide stress, we established the common gene and pathway clusters that are implicated in general and biocide-specific stress responses. Our analysis revealed a temporal choreography, starting from the upregulation of chaperones to the subsequent repression of motility and chemotaxis pathways and the induction of an anaerobic pool of enzymes and biofilm regulators. A systematic analysis of the transcriptional data identified a zur-regulated gene cluster to be highly active in the stress response against sodium hypochlorite and peracetic acid, presenting a link between the biocide stress response and zinc homeostasis. Susceptibility assays with knockout mutants further validated our findings and provide clear targets for downstream investigation of the implicated mechanisms of action.IMPORTANCE Antiseptics and disinfectant products are of great importance to control and eliminate pathogens, especially in settings such as hospitals and the food industry. Such products are widely distributed and frequently poorly regulated. Occasional outbreaks have been associated with microbes resistant to such compounds, and researchers have indicated potential cross-resistance with antibiotics. Despite that, there are many gaps in knowledge about the bacterial stress response and the mechanisms of microbial resistance to antiseptics and disinfectants. We investigated the stress response of the bacterium Escherichia coli to 10 common disinfectant and antiseptic chemicals to shed light on the potential mechanisms of tolerance to such compounds.

The use of disinfection tunnels or disinfectant spraying of humans as a measure to reduce the spread of the SARS-CoV-2 virus

In endeavouring to mitigate the spread of the SARS-CoV-2 virus, a concerning practice of spraying individuals with disinfectant via so-called 'disinfection tunnels' has come to light. The Allergy Society of South Africa supports the World Health Organization in strongly condemning all human spraying, owing to lack of efficacy and potential dangers, especially to patients with coexisting allergic conditions.

Molecular Profiling on Surface-Disinfected Tomato Seeds Reveals High Diversity of Cultivation-Recalcitrant Endophytic Bacteria with Low Shares of Spore-Forming Firmicutes

Seeds are known to harbor diverse microorganisms offering protective effects on them with the prospects of quick root colonization at germination, selective recruitment as endophytes, and possible vertical transmission. The study was undertaken to assess the gross seed-internal bacterial community in tomato and to confirm if spore-forming Firmicutes constituted major seed endophytes adopting cultivation versus molecular approach on surface-sterilized seeds. Testing the initial seed wash solutions of "Arka Vikas" and "Arka Abha" cultivars showed > 1000 bacterial cfu per dry seed, largely Bacillus spp. Tissue homogenates from surface-disinfected seeds did not show any cultivable bacteria on enriched media for 1-2 weeks, while 16S rRNA V3-V4 taxonomic profiling revealed a huge bacterial diversity (10-16 phyla per cultivar). Proteobacteria formed the dominant phylum (65.7-69.6% OTUs) followed by Firmicutes, Actinobacteria, Bacteroidetes, and a notable share of Euryarchaeota (1.1-3.1%). Five more phyla appeared common to both cultivars in minor shares (Acidobacteria, Planctomycetes, Chloroflexi, Spirochaetes, Verrucomicrobia) with the ten phyla together constituting 99.6-99.9% OTUs. Class level and family level, the cultivars displayed elevated bacterial diversity, but similar taxonomic profiles. Arka Vikas and Arka Abha showed 114 and 107 genera, respectively, with 63 common genera constituting 96-97% OTUs. Psychrobacter formed the dominant genus. Bacillus and related genera constituted only negligible OTU share (0.16-0.28%). KEGG functional analysis showed metabolism as the major bacterial community role. One-month-old in vitro seedlings showed the activation of some originally uncultivable bacteria uninfluenced by the OTU share. The study reveals a high diversity of cultivation-recalcitrant endophytic bacteria prevailing in tomato seeds with possible vertical transmission and significant roles in plant biology.

Protection and disinfection policies against SARS-CoV-2 (COVID-19)

In late December 2019, reports from China of the incidence of pneumonia with unknown etiology were sent to the World Health Organization (WHO). Shortly afterwards, the cause of this disease was identified as the novel beta-coronavirus, SARS-CoV-2, and its genetic sequence was published on January 12, 2020. Human-to-human transmission via respiratory droplets and contact with aerosol infected surfaces are the major ways of transmitting this virus. Here we attempted to collect information on virus stability in the air and on surfaces and ways of preventing of SARS-CoV-2 spreading.

The Formation, Persistence, and Resistance to Disinfectant of the Erysipelothrix piscisicarius Biofilm

Erysipelothrix piscisicarius is an emergent pathogen in fish aquaculture, particularly in the ornamental fish trade. Very little is known on the biology of this pathogen; however, the recurrence of infection and disease outbreaks after removing the fish from a system and disinfecting the tank suggest its environmental persistence. Moreover, biofilm lifestyle in E. piscisicarius has been suspected but not previously shown. The purpose of this study was to investigate the formation of biofilms on an abiotic surface in Erysipelothrix spp. We used hydroxyapatite-coated plastic pegs to demonstrate the attachment, growth, and persistence of E. piscisicarius on abiotic surfaces in both fresh and marine environments and to investigate the susceptibility of this pathogen to different disinfectants that are used in the aquaculture industry. E. piscisicarius formed biofilms that persisted significantly longer than planktonic cells did in both freshwater and saltwater over a period of 120 h (P = 0.004). The biofilms were also more resistant to disinfectants than the planktonic cells were. Hydrogen peroxide was the most effective disinfectant against E. piscisicarius, and it eradicated the biofilms and planktonic cells at the recommended concentrations. In contrast, Virkon and bleach were able to eradicate only the planktonic cells. This information should be taken into consideration when developing biosecurity protocols in aquaculture systems, aquariums, and private collections.

Cannula and circuit management in peripheral extracorporeal membrane oxygenation: An international survey of 45 countries

Effective and safe practices during extracorporeal membrane oxygenation (ECMO) including infection precautions and securement of lines (cannulas and circuits) are critical to prevent life-threatening patient complications, yet little is known about the practices of bedside clinicians and data to support best practice is lacking. Therefore, the aim of this study was to identify and describe common line-related practices for patients supported by peripheral ECMO worldwide and to highlight any gaps for further investigation. An electronic survey was conducted to examine common line practices for patients managed on peripheral ECMO. Responses were obtained from 45 countries with the majority from the United States (n = 181) and United Kingdom (n = 32). Standardised infection precautions including hand hygiene, maximal barrier precautions and skin antisepsis were commonplace for cannulation. The most common antisepsis strategies included alcohol-based chlorhexidine gluconate (CHG) for cannula insertion (53%) and maintenance (54%), isopropyl alcohol on circuit access ports (39%), and CHG-impregnated dressings to cover insertion sites (36%). Adverse patient events due to line malposition or dislodgement were reported by 34% of respondents with most attributable to ineffective securement. Centres 'always' suturing peripheral cannula sites were more likely to experience a cannula adverse event than centres that 'never' sutured (35% [95% CI 30, 41] vs 0% [95% CI 0, 28]; Chi-square 4.40; p = 0.04) but this did not meet the a priori significance level of <0.01. An evidence-based guideline would be beneficial to improve ECMO line management according to 78% of respondents. Evidence gaps were identified for antiseptic agents, dressing products and regimens, securement methods, and needleless valves. Future research addressing these areas may provide opportunities for consensus guideline development and practice improvement.

Application of slightly acidic electrolyzed water and ultraviolet light for Salmonella enteritidis decontamination of cell suspensions and surfaces of artificially inoculated plastic poultry transport coops and other facility surfaces

The efficiency of combination treatment of slightly acidic electrolyzed water (SAEW) and ultraviolet light (UV) for inactivation of Salmonella enteritidis (S. enteritidis) on the surface of plastic poultry coops and other facility surfaces was evaluated in the presence of organic matter. The bactericidal activities of SAEW, UV + SAEW, and composite phenol (CP) for inactivating S. enteritidis were also compared. Moreover, a model of UV + SAEW treatment of plastic transport coops with different times and available chlorine concentrations (ACC) was developed using multiple linear regression analysis. There are differences between SAEW and CP inactivation of S. enteritidis on coops, stainless steel, and glass surfaces (P < 0.05), and there are no differences between SAEW and CP on tire surfaces (P > 0.05). Disinfection of some rough material surfaces with SAEW treatment alone under feces interference on poultry farms may need a longer treatment time and/or a higher ACC than smooth surfaces. The combined treatment of UV and SAEW showed higher inactivation efficiency of S. enteritidis compared to CP and SAEW treatment alone (P < 0.05) in pure cultures or on the facility surfaces. A complete 100% inactivation of S. enteritidis on plastic poultry coop surfaces was obtained by using UV + SAEW with an ACC of 90 mg/L for more than 70 s. The established model had a good fit that was quantified by the determination coefficient R² (0.93) and a lack of fit test (P > 0.05). The bactericidal efficiency of UV + SAEW increased with greater ACC and increasing time. The findings of this study indicate that the combination treatment of UV and SAEW may be a promising disinfection method and could be used instead of SAEW alone, especially on rough materials in the presence of organic matter on poultry farms.

Decontamination of aerosolised bacteria from a pig farm environment using a pH neutral electrochemically activated solution (Ecas4 anolyte)

An electrochemically activated solution (ECAS), generated by electrolysis of a dilute sodium chloride solution in a four-chamber electrolytic cell (Ecas4), was tested as a sanitising aerosol in eliminating bacteria from the environment of a weaning room vacated 24-48h earlier, at a continuous flow pig farm. An ultrasonic humidifier was used to fill the environment with a fog (droplets with diameters of 1–5 μm) containing 0.25 ppm of hypochlorous acid. The weaning room was fogged for 3 min at 30 min intervals during five hours of aerosol disinfection. An innovative sample treatment with propidium monoazide dye in conjunction with cyclonic air sampling was optimised and adapted for discerning live/dead bacteria in subsequent molecular quantification steps. Without fogging, total bacterial load ranged from 5.06 ± 0.04 to 5.75 ± 0.04 Log₁₀ CFU/m³. After the first hour of fogging, a 78% total bacterial reduction was observed, which further increased to > 97% after the second hour, > 99.4% after the third and 99.8% after the fourth hour, finally resulting in a 99.99% reduction from the farm environment over five hours. Unlike the current formaldehyde spray disinfection protocol, which requires a long empty period because of its hazardous properties, this economically viable and environmentally friendly disinfection protocol may significantly lower downtime. Moreover, ECAS fogging can be easily adapted to a variety of applications, including the elimination of pathogens from livestock farm air environment for disease prevention, as well as decontamination after disease outbreaks.

Limited association between disinfectant use and either antibiotic or disinfectant susceptibility of Escherichia coli in both poultry and pig husbandry

BACKGROUND

Farm disinfectants are widely used in primary production, but questions have been raised if their use can select for antimicrobial resistance. The present study examined the use of disinfectants in poultry and pig husbandry and its contribution to the antibiotic and disinfectant susceptibility of Escherichia coli (E. coli) strains obtained after cleaning and disinfection. On those field isolates antibiotic susceptibility was monitored and susceptibility to commonly used active components of farm disinfectants (i.e. glutaraldehyde, benzalkoniumchloride, formaldehyde, and a formulation of peracetic acid and hydrogen peroxide) was tested.

RESULTS

This study showed a high resistance prevalence (> 50%) for ampicillin, sulfamethoxazole, trimethoprim and tetracycline for both production animal categories, while for ciprofloxacin only a high resistance prevalence was found in broiler houses. Disinfectant susceptibility results were homogenously distributed within a very small concentration range. Furthermore, all E. coli strains were susceptible to in-use concentrations of formaldehyde, benzalkoniumchloride and a formulation of peracetic acid and hydrogen peroxide, indicating that the practical use of disinfectants did not select for disinfectant resistance. Moreover, the results showed no indications for the selection of antibiotic resistant bacteria through the use of disinfectants in agricultural environments.

CONCLUSION

Our study suggests that the proper use of disinfectants in agricultural environments does not promote antibiotic resistance nor reduce E. coli disinfectant susceptibility.

Direct and Indirect Effect of Chlorhexidine on Survival of Stem Cells from the Apical Papilla and Its Neutralization

INTRODUCTION

Several irrigants have been used for disinfection in regenerative endodontic procedures including chlorhexidine (CHX). In this context, the antibacterial properties of disinfectants are mainly in focus of research even though they may have an undesirable impact on the fate of stem cells. In this study, we hypothesized that CHX has both a direct effect when applied to stem cells of the apical papilla (SCAPs) and an indirect effect when SCAPs are exposed to dentin previously conditioned with CHX.

METHODS

Cell toxicity was evaluated in vitro using the CellTox green fluorescence assay (Promega, Madison, WI) and CellTiter-Glo (Promega) after SCAPs were exposed directly to a dynamic concentration range of CHX; apical papilla explant cultures were stained with ApopTag (Merck Millipore, Billerica, MA) after culture with CHX. Furthermore, standardized slabs from human dentin were treated with CHX and consecutively rinsed in EDTA, L-α-lecithin (Sigma-Aldrich, St Louis, MO), or L-α-lecithin followed by EDTA. After that, SCAPs were cultured on the slabs for 5 days, and cellular viability was determined (indirect effect). Data were treated nonparametrically and analyzed using the Krukal-Wallis test (P ≤ .05).

RESULTS

Direct exposure of SCAPs to CHX highly affected cell viability at concentrations above 10^-3%, whereas lower concentrations had no adverse effect. During the initial 60 minutes, concentrations of 10^-2% CHX or higher resulted in early pronounced toxicity with a maximum effect within 15 minutes after exposure. Likewise, CHX-conditioned dentin slabs were detrimental to SCAP survival; however, the deleterious effects were completely reversed by neutralization with L-α-lecithin.

CONCLUSIONS

Chlorhexidine is toxic to SCAPs when applied directly or indirectly via conditioned dentin. If applied for a short time and neutralized by L-α-lecithin, it can be a gentle and cell-preserving disinfectant before endodontic regeneration.

In situ evaluation of a persistent disinfectant provides continuous decontamination within the clinical environment

Microbial bioburden associated with the built environment can impact the rate of health care-associated infection acquisition; higher bioburden results in a greater incidence of health care-associated infections. Two disinfectants registered by the US Environmental Protection Agency and a trial disinfectant were evaluated for their ability to limit the establishment of bioburden subsequent to application under in situ conditions on patient bed rails within a medical intensive care unit. Bioburden samples were collected immediately prior to disinfection and at 1, 6, and 24 hours after application. The trial disinfectant was engineered to provide continuous disinfection over a 24-hour period. Each disinfectant was able to significantly control bioburden for the first hour. In comparison, the persistent agent was found superior for all time points when compared to a dilutable quaternary ammonium agent, and it was significantly better for controlling bioburden for 2 of the 3 times points for the disinfectant with ethanol and quaternary ammonium as its agent.

Use of germicides in health care settings-is there a relationship between germicide use and antimicrobial resistance: A concise review

Despite the widespread use of disinfectants and antiseptics in hospitals, acquired resistance to current disinfectants has rarely been reported. Germicides, as with medications, should only be used when their benefit as demonstrated by scientific studies exceeds possible risks to human health or the environment.

Service evaluation of alcohol-release door plates: an addition to hand hygiene

A service evaluation was designed to examine the effect of installation of alcohol-releasing Surfaceskins doorplates on routine alcohol hand gel hygiene use by healthcare workers. There was an approximate doubling increase in healthcare worker use of alcohol hand gel dispensers following the installation of Surfaceskins doorplates in two operating theatre suites. No evidence was found that Surfaceskins doorplates replaced routine hand hygiene. It is concluded that these devices represent a useful adjunct to routine hand hygiene practice in healthcare environments, and potentially in other settings (e.g. washrooms, restaurants) where frequent contact with doors could undermine infection prevention practice.

Early-stage Management of Complex Wounds Using Negative Pressure Wound Therapy With Instillation and a Dressing With Through Holes

INTRODUCTION

An early-stage decision clinicians often make in the management of complex wounds is which method of wound preparation will be appropriate for the patient. This decision can be affected by numerous wound and patient risk factors that present challenges and may make surgical debridement difficult in patients with complex wounds. Recently, negative pressure wound therapy with instillation and dwell time (NPWTi-d) using a novel reticulated open-cell foam dressing with through holes (ROCF-CC) was shown to aid in the loosening and removal of thick exudate and nonviable tissue from wounds.

OBJECTIVE

The authors present their experiences of using NPWTi-d with ROCF-CC, along with rationales for wound care decisions.

MATERIALS AND METHODS

Patients received antibiotics and surgical debridement when appropriate. Therapy selection and parameters were based on a decision-tree model for wound care management that takes into consideration patient and wound information. Most patients received NPWTi-d with ROCF-CC for a duration of 5 to 8 days; however, 1 patient received NPWTi-d with ROCF-CC for more than 30 days due to the wound extent and severity. Therapy consisted of instilling saline or quarter-strength sodium hypochlorite solution with dwell times of 3 to 10 minutes, followed by 2 hours or 3.5 hours of NPWT either at -100 mm Hg or -125 mm Hg.

RESULTS

There were 6 patients (3 men, 3 women; average age, 58.5 years) treated. Wound types included 3 pressure ulcers, 1 necrotizing soft tissue infection, 1 perianal abscess, and 1 large abdominal wound. Patient comorbidities included obesity, type 2 diabetes, and radiation therapy. In all cases, progression of wound healing was observed with no complications. This method produced viable granulation tissue and wound bed preparation; however, patients were not followed to closure or grafting.

CONCLUSIONS

These cases help support the use of NPWTi-d with ROCF-CC as a viable option for wound care providers in the early-stage management of complex wounds.

Slow delivery of biocide from nanostructured, microscaled, particles reduces its phytoxicity: A model investigation

Nano-engineered delivery systems have emerged as possible solutions for more efficient pest management in agriculture. Likewise for nanostructured drug delivery systems (DDS) in medicine, the use of biocide delivery systems (BDS) brought concerns on their toxicology on non-targeted organisms. Plants, for instance, are the foundation of the ecosystem, acting as primary actor in the food chain and is associated with the whole biodiversity, being strictly related to human health. This is a very important consideration to fully understand the benefits of using delivery systems for crop protection and production. Herein, a biocide delivery system was prepared by loading nanostructured, microscaled, biogenic silica particles with thymol, a known phytotoxicant. The resulting system contains 120 mg of thymol per gram of silica and displays slow release features. The Allium cepa bioassay was chosen to demonstrate how the toxicity and cellular damages induced by thymol can be significantly reduced through a slow, controlled, release strategy. The lower mobility of the reference particles associated with slow-delivery features reduced the toxicity and cellular damages caused by thymol in the plant genetic model.

[Superficial surgical site infections in dermatologic surgery]

Surgical site infections (SSIs) in dermatologic surgery are rare, but when they do occur they can cause unnecessary suffering in patients, delayed healing, and result in poor scar cosmesis. The etiology and pathogenesis of SSIs in dermatologic surgery are not completely understood and most current preventative measures lack strong scientific evidence. Focusing on dermatologic surgery, this article provides an updated overview of the subject with data summarizing relevant studies.

Evaluation of a biocide footbath solution in the occurrence and healing of digital dermatitis lesions in dairy cows: A clinical trial

The objective of this study was to evaluate the effect of the implementation of different footbathing practices using a new biocide solution (Pink-Step™, Qalian, France) in the healing and the occurrence of bovine digital dermatitis (bDD) lesions. The investigation was conducted through a controlled within cow clinical trial in which the hind feet of cows from each farm were allocated either to the control group or to a moderate (MR) or (IR) intensive footbath-regimen groups. The trial involved 1036 cows (2072 feet) from 10 dairy farms located in western France where bDD was endemic. Split-footbaths were placed at the exit of the milking parlor of each farm, allowing the biocide to be administered to one side of the cows while using the other empty side as a negative control. The administration frequency for MR was of 2 days/week/1st-month, then 2 days/2 weeks/2nd-month, and then 2 days/month, and for IR was of 2 days/week/1st-2nd months, and then 2 days/2 weeks. Footbaths were administered during 140 days (approx.), and feet were evaluated for the at least once a month in the milking parlor. Nested survival models were used to estimate the relative impact of the footbath regimens and other concomitant risk factors on the time that bDD lesions occurred or healed. No effect of Pink-Step™ was evidenced on the bDD occurrence during the trial. The risk for bDD occurrence was increased by poor feet cleanliness at both the cow (HR 1.69, CI 1.21-2.39) and farm level (HR 2.06, CI 1.44-2.94). Otherwise, the use of Pink-Step™ in an IR was effective in improving the healing of bDD lesions (HR 1.79, CI 1.12-2.88). The time to healing was also improved in inactive lesions (HR 2.19, CI 1.42-3.37). Conversely, the time to healing was delayed in feet receiving hoof-trimming (HR 0.41, CI 0.26-0.62), in cows with a contralateral bDD lesion (HR 0.32, CI 0.22-0.46) or in late lactation (HR 0.61, CI 0.43-0.85), and finally in farms with more than 100 cows (HR 0.48, CI 0.34-0.67). These findings reinforce the crucial role of hygiene in bDD dynamics and highlight the importance of implementing multiple control measures simultaneously, such as hygiene improvements in the barn, early detection and treatment of bDD lesions and the correct usage of individual and collective treatments. The implementation of Pink-Step™ represents a promising strategy for reducing the persistence of bDD lesions in affected herds.

Attachment strength and on-farm die-off rate of Escherichia coli on watermelon surfaces

Pre-harvest contamination of produce has been a major food safety focus. Insight into the behavior of enteric pathogens on produce in pre-harvest conditions will aid in developing pre-harvest and post-harvest risk management strategies. In this study, the attachment strength (S_R) and die-off rate of E. coli on the surface of watermelon fruits and the efficacy of aqueous chlorine treatment against strongly attached E. coli population were investigated. Watermelon seedlings were transplanted into eighteen plots. Prior to harvesting, a cocktail of generic E. coli (ATCC 23716, 25922 and 11775) was inoculated on the surface of the watermelon fruits (n = 162) and the attachment strength (S_R) values and the daily die-off rates were examined up to 6 days by attachment assay. After 120 h, watermelon samples were treated with aqueous chlorine (150 ppm free chlorine for 3 min). The S_R value of the E. coli cells on watermelon surfaces significantly increased (P<0.05) from 0.04 to 0.99 in the first 24 h, which was primarily due to the decrease in loosely attached population, given that the population of strongly attached cells was constant. Thereafter, there was no significant change in S_R values, up to 120 h. The daily die-off rate of E. coli ranged from -0.12 to 1.3 log CFU/cm². The chlorine treatment reduced the E. coli level by 4.2 log CFU/cm² (initial level 5.6 log CFU/cm²) and 0.62 log CFU/cm² (initial level 1.8 log CFU/cm²), on the watermelons that had an attachment time of 30 min and 120 h respectively. Overall, our findings revealed that the population of E. coli on watermelon surfaces declined over time in an agricultural environment. Microbial contamination during pre-harvest stages may promote the formation of strongly attached cells on the produce surfaces, which could influence the efficacy of post-harvest washing and sanitation techniques.

Patient perceptions of chlorhexidine bathing: A pilot study using the health belief model

BACKGROUND

Many studies investigating daily chlorhexidine gluconate (CHG) bathing as an infection control intervention to decrease health care-associated infections have focused on reduction of infection and colonization; few studies have assessed CHG bathing compliance, work system factors, facilitators, and barriers to implementation.

METHODS

This is a combination retrospective/prospective pilot study conducted at a large academic teaching hospital that implemented daily CHG bathing across all inpatient units. CHG compliance and patient refusal were calculated on the basis of documentation in the electronic medical record. We used the health belief model to guide semistructured interviews with patients about knowledge and barriers related to CHG bathing.

RESULTS

Of the 31 patients interviewed, 74% reported using CHG soap during their stay. Average compliance documented in the electronic medical record was 78% with a range of 57%-91% among all hospital units. Sixteen percent of patients declined CHG bathing, and refusal ranged from 3%-29% among all units. Major themes about CHG bathing from patient interviews include low perceived susceptibility to infection, high degree of trust in medical professionals, low knowledge of benefits of CHG, and low perceived self-efficacy in preventing HAIs.

CONCLUSIONS

Educating patients about CHG bathing appears to be a critical factor in decreasing patient refusal of CHG bathing.

Proceedings of the 2017 Viral Clearance Symposium Session 5: Facility Risk Mitigation

The discussion on facility risk mitigation was included for the first time at the 2017 Viral Clearance Symposium. A few topics were discussed in this session, including sanitization/cleaning against viruses, viral segregation, as well as the definition of a "functionally closed" system.Virus inactivation by disinfectants is critical for the biotechnology industry. The efficacy can differ, depending on whether applied to surfaces, in solutions, or in gas phases, as well as the respective disinfectants (i.e., peracetic acid/hydrogen peroxide-based, hypochlorite-based, or glutaraldehyde-based).Most equipment used in the biotech industry can be cleaned or sanitized by alkaline solutions. Many of these methods were studied regarding their virus reduction potential and were defined considering alkaline concentration, time, and temperature.Virus clearance may be compromised if cross contamination or carryover happens from an early step with potentially a higher level of virus to a later step in the purification process (i.e., after virus removal or inactivation). Critical potential carryover (V_cpc) is defined as the volume of carryover that will significantly affect the overall virus clearance of a purification process. Based on the evaluation of critical potential carryover, mitigation actions can be introduced to avoid such carryover.Appropriate segregation within manufacturing facilities is required by regulators and utilized by manufacturers to ensure that the final product has appropriate safety margins. However, consensus around basic definitions and approaches related to facility segregation is lacking. To address this gap, the member companies of the Consortium on Adventitious Agent Contamination in Biomanufacturing have begun a project with the goal of developing a definition for a "functionally closed" manufacturing system.LAY ABSTRACT: The discussion on facility risk mitigation was included for the first time at the 2017 Viral Clearance Symposium. The topics discussed in this session included sanitization/cleaning against viruses, viral segregation, as well as the definition of a "functionally closed" system.Virus inactivation by disinfectants is critical for the biotechnology industry. The efficacy can differ, depending on whether applied to surfaces, in solutions, or in gas phases, as well as the respective disinfectants.Most equipment used in the biotech industry can be cleaned or sanitized by alkaline solutions. Many of these methods were studied regarding their virus reduction potential and were defined considering alkaline concentration, time, and temperature.Virus clearance may be compromised if cross contamination or carryover happens from an early step with potentially a higher level of virus to a later step in the purification process (i.e., after virus removal or inactivation).Regarding segregation within manufacturing facilities, the member companies of the Consortium on Adventitious Agent Contamination in Biomanufacturing have begun a project with the goal of developing a definition for a "functionally closed" manufacturing system. During this session, the current definition was discussed.

Disinfection of Blood Pressure Cuffs and Electrocardiographic Telemetry Leads With 0.5% Hydrogen Peroxide Wipes

BACKGROUND

Disinfection of frequently touched surfaces in the hospital is critical for providing safe care. Because of their complex intricate surfaces, blood pressure cuffs and electrocardiographic telemetry leads may be harder than other equipment to disinfect.

OBJECTIVE

To determine the effectiveness of 0.5% hydrogen peroxide wipes in cleaning and disinfecting inpatient hospital surfaces, including hook and loop (Velcro) fasteners of blood pressure cuffs and electrocardiographic telemetry leads.

METHODS

A prospective study of an inpatient telemetry unit was designed to measure the persistence of a UV indicator and the presence of bacterial colonization on electrocardiographic telemetry leads and blood pressure cuffs. Call buttons and patient trays were used as control surfaces, because they are often touched but are easy to disinfect via standard practices.

RESULTS

A total of 392 samples were collected between July 11 and August 3, 2016, and cultured for microorganisms. Among the cultures, 247 (63%) had at least 1 colony-forming unit. After adjustments in a multivariable analysis, odds of a contaminated surface (≥ 10 colony-forming units) after final cleaning with 0.5% hydrogen peroxide wipes were 3.70 times greater for patient trays than for blood pressure cuffs (P = .03) and 3.80 times greater for telemetry leads than for blood pressure cuffs (P = .04). The UV indicator persisted longer on blood pressure cuffs and telemetry leads than on patient trays or call buttons (P < .001).

CONCLUSION

Wipes with 0.5% hydrogen peroxide adequately disinfect blood pressure cuffs but not telemetry leads.

[Disinfection of injection ports - a systematic overview of optimal scrub-time]

Central venous catheter bloodstream infections are an important cause of hospital-acquired infection with increased morbidity, mortality and cost. The incidence varies between countries and even hospitals. Needleless connector hubs are used on virtually all intravascular devices and colonization of these is considered the cause of much of the postinsertion catheter-related infections through breaks in aseptic technique and failure to disinfect properly. This systematic review evaluated 165 search hits on hub disinfection practices with particular emphasis on the time of scrubbing the connector for 15 sec but also the impact of measures of education and compliance. We found no randomized controlled trials (RCT) that addressed the question of scrubbing time but four in vitro studies and two clinical studies (one Swedish and one American) supported the instruction to scrub the hub for 15 sec.  Where studied, compliance with disinfection protocols was found to be surprisingly low. Though the optimal technique or disinfection time has not formally been identified through RCTs, nevertheless scrubbing with chlorhexidine-alcohol for 15 sec is seen as a reasonable recommendation and consistent with conclusions of three big reviews during the past three years (two from the UK, and one from Australia/USA).

The microbial killing capacity of aqueous and gaseous ozone on different surfaces contaminated with dairy cattle manure

A high reactivity and leaving no harmful residues make ozone an effective disinfectant for farm hygiene and biosecurity. Our objectives were therefore to (1) characterize the killing capacity of aqueous and gaseous ozone at different operational conditions on dairy cattle manure-based pathogens (MBP) contaminated different surfaces (plastic, metal, nylon, rubber, and wood); (2) determine the effect of microbial load on the killing capacity of aqueous ozone. In a crossover design, 14 strips of each material were randomly assigned into 3 groups, treatment (n = 6), positive-control (n = 6), and negative-control (n = 2). The strips were soaked in dairy cattle manure with an inoculum level of 10⁷–10⁸ for 60 minutes. The treatment strips were exposed to aqueous ozone of 2, 4, and 9 ppm and gaseous ozone of 1and 9 ppm for 2, 4, and 8 minutes exposure. 3M™ Petrifilm™ rapid aerobic count plate and plate reader were used for bacterial culture. On smooth surfaces, plastic and metal, aqueous ozone at 4 ppm reduced MBP to a safe level (≥5-log₁₀) within 2 minutes (6.1 and 5.1-log₁₀, respectively). However, gaseous ozone at 9 ppm for 4 minutes inactivated 3.3-log₁₀ of MBP. Aqueous ozone of 9 ppm is sufficient to reduce MBP to a safe level, 6.0 and 5.4- log_10, on nylon and rubber surfaces within 2 and 8 minutes, respectively. On complex surfaces, wood, both aqueous and gaseous ozone at up to 9 ppm were unable to reduce MBP to a safe level (3.6 and 0.8-log₁₀, respectively). The bacterial load was a strong predictor for reduction in MBP (P<0.0001, R² = 0.72). We conclude that aqueous ozone of 4 and 9 ppm for 2 minutes may provide an efficient method to reduce MBP to a safe level on smooth and moderately rough surfaces, respectively. However, ozone alone may not an adequate means of controlling MBP on complex surfaces.

Dimensional Accuracy of Alginate Impressions Using Different Methods of Disinfection With Varying Concentrations

This study investigated the effect of 1% and 5.25% of sodium hypochlorite (NaOCl) as spray and immersion solutions on the dimensional accuracy of an irreversible hydrocolloid impression material. Impressions of master models were taken using irreversible hydrocolloid impression material, which was then treated with NaOCl 1% or 5.25% solution, either by spaying or immersion, for 5 minutes, or not treated to act as control. The impressions were then poured with stone, and the dimensional accuracy was determined from the mean of six measurements taken between fixed points using a digital caliper. No significant dimensional changes of gypsum casts obtained from irreversible hydrocolloid impression material sprayed with NaOCl solution were observed, whereas significant change in dimensional accuracy occurred when the casts were immersed in NaOCl solution. Based on dimensional stability alone it would be more appropriate to disinfect irreversible hydrocolloid impression material by spraying it with NaOCl solution rather than immersing it.

Attenuating Effect of Zinc and Vitamin E on the Intestinal Oxidative Stress Induced by Silver Nanoparticles in Broiler Chickens

Silver nanoparticles (AgNPs) have been increasingly used as antimicrobial and disinfectant. However, intestinal model studies have shown that AgNPs induce oxidative stress. Hence, this study aims to investigate the effects of dietary supplemental zinc (Zn) and vitamin E (VE; α-tocopherol acetate) on attenuating AgNP-induced intestinal oxidative stress in broiler chickens. The chickens were divided into two groups as follows: (1) control group fed with a corn-soybean meal basal diet and (2) nano group, received drinking water containing 1000 mg/kg AgNPs. All the nano-exposed birds were divided into six dietary treatment groups, namely, the basal diets supplemented with (1) 60 mg/kg Zn as ZnSO₄, (2) 120 mg/kg Zn, (3) 100 mg/kg VE, (4) 200 mg/kg VE, (5) 60 mg/kg Zn and 100 mg/kg VE, and (6) 120 mg/kg Zn and 200 mg/kg VE. Results showed that the AgNPs significantly reduced the body weights of the broilers after 42 days of oral administration of AgNPs (P < 0.05), and this effect was not alleviated by any of the dietary treatments. The activity of superoxide dismutase (CuZn-SOD) increased in all the AgNP-treated birds (P < 0.05); however, CuZn-SOD did not increase in birds fed with basal diet supplemented with 200 mg/kg VE. In this treatment, the VE exerted an antioxidant effect to prevent the activation of the CuZn-SOD enzyme. Furthermore, supplementing Zn increased the activities of catalase and glutathione peroxidase in the jejunal mucosa (P < 0.05), which were accompanied with increased malondialdehyde levels (P < 0.05) in the broilers. AgNP exposure resulted in a significant messenger RNA (mRNA) upregulation of toll-like receptor 4 (TLR4) and TLR2-1 in the jejunal mucosa (P < 0.05). However, supplemental ZnVE did not reduce TLRs' mRNA expression, except for the diminished TLR2-1 mRNA levels in birds fed with basal diet supplemented with 120 mg/kg Zn and 200 mg/kg VE. We concluded that although dietary Zn and VE supplementation did not attenuate growth depression effect of AgNP, it however attenuates intestinal oxidative stress in AgNP-treated broiler chickens.

Effects of contact time and concentration on bactericidal efficacy of 3 disinfectants on hard nonporous surfaces

This study investigated the influence of contact time and concentration on bactericidal efficacy of 3 types of disinfectants (accelerated hydrogen peroxide [AHP], quaternary ammonium compounds [Quats], and sodium hypochlorite) on stainless steel surfaces using Environmental Protection Agency procedure MB-25-02. We found that bactericidal efficacy was not reduced at contact times or concentrations immediate lower than label use values, but all 3 disinfectants were significantly less bactericidal at significantly lower than label use contact times and concentrations. Overall, the bactericidal efficacy of the sodium hypochlorite disinfectant was most tolerant to the decreases of contact times and concentrations, followed closely by AHP disinfectant, and Quat disinfectant was most affected by contact time and concentration.

Daily bathing strategies and cross-transmission of multidrug-resistant organisms: Impact of chlorhexidine-impregnated wipes in a multidrug-resistant gram-negative bacteria endemic intensive care unit

BACKGROUND

Health-care associated infections are a major cause of morbidity and mortality in critical care units. The aim of this study is to evaluate the effectiveness of chlorhexidine gluconate (CHG)-impregnated wipes in the daily bathing of patients in an intensive care unit (ICU) to prevent cross-transmission and colonization by multidrug-resistant organisms (MDROs) METHODS: Prospective cohort study with an intervention of 11 months. The intervention consisted of using CHG-impregnated wipes for the daily bathing of patients on mechanical ventilation or colonized by MDROs. Monthly trends in the number of patients colonized by MDROs and the incidence of nosocomial infections were evaluated.

RESULTS

A total of 1,675 patients were admitted to the unit during the intervention period, and 430 (25.7%) were bathed with chlorhexidine wipes. A significant decrease was observed in the incidence of colonization by MDROs over the months (β = -0.209; r² = 0.549; P = .027), and in the number of patients colonized compared with the equivalent period of the previous year (22.0% vs 18.4%; P = .01). No significant decrease was observed in the incidence of nosocomial infection between the two periods (4.11% vs 4.57%; P = .355). No dermatologic problems were observed in the treated patients.

CONCLUSIONS

The use of CHG-impregnated wipes reduces cross-transmission and colonization by MDROs in the ICUs in an endemic situation because of multidrug-resistant Enterobacteriaceae.

Evaluation of Novel Process Indicators for Rapid Monitoring of Hydrogen Peroxide Decontamination Processes

Geobacillus stearothermophilus spores on stainless steel discs are routinely used as biological indicators for the validation of hydrogen peroxide bio-decontamination processes. Given ongoing concerns about the reliability and response time of biological indicators, we explored the potential for an enzyme-based approach to decontamination process evaluation. Thermostable adenylate kinase enzyme was coated onto a solid support and exposed to hydrogen peroxide vapour, in parallel with standard commercial 6-log biological indicators, during a series of vapour-phase hydrogen peroxide cycles in a flexible film isolator. The exposed biological indicators were enumerated to define the degree of kill at different time intervals and the results compared to the thermostable adenylate kinase values, as determined by measuring adenosine triphosphate produced by residual active enzyme. Both biological indicators and the thermostable adenylate kinase indicators exhibited a biphasic inactivation profile during the process. There was significant variance between individual cycles, with some cycles showing complete inactivation of the biological indicators to the limit of detection of the assay, within 6 min, whereas biological indicators in some cycles were inactivated at a time greater than 12 min. The log-kill of the biological indicators at intermediate time points were plotted and compared to the fully quantifiable measurements derived from the thermostable adenylate kinase indicators at the same time points. The results demonstrated very similar inactivation profiles for the enzyme and for the biological indicators, thus it was possible to define a relationship between relative light units measurement and biological indicator kill. This indicates that it is possible to use thermostable adenylate kinase measurement as a direct measure of vapour-phase hydrogen peroxide bio-decontamination performance, expressed in terms of log reduction. Because thermostable adenylate kinase measurement can be achieved within a few minutes of vapour-phase hydrogen peroxide cycle completion, compared with a minimum of 7 days for the evaluation of biological indicator growth, this offers a potentially valuable tool for rapid vapour-phase hydrogen peroxide bio-decontamination cycle development and subsequent re-qualification.LAY ABSTRACT: Pharmaceutical product manufacture is performed in controlled cleanroom and closed chamber environments (isolators) to reduce the risk of contamination. These environments undergo regular decontamination to control microbial contamination levels, using a range of methods, one of which is to vaporize hydrogen peroxide (a chemical disinfectant) into a gas or an aerosol and disperse it throughout the environment, killing any microorganisms present. Biological indicators, which consist of a small steel coupon carrying a population of bacterial spores that are more resistant to hydrogen peroxide than are most microorganisms, are placed within the environment, and then tested for growth following treatment to ensure the process was effective. Confirmation of growth/no growth (and therefore hydrogen peroxide cycle efficacy) can take up to 7 days, which significantly increases time and cost of developing and confirming cycle efficacy. This study tests whether a new technology which uses a robust enzyme, thermostable adenylate kinase, could be used to predict biological indicator growth. The study shows this method can be used to confirm hydrogen peroxide cycle efficacy, by predicting whether the BI is killed at a specific time point or not and results are obtained in a few minutes rather than 7 days. This potentially offers significant time and cost benefits.

Attitudes and practices of Irish hospital-based physicians towards hand hygiene and hand rubbing using alcohol-based hand rub: a comparison between 2007 and 2015

BACKGROUND

Hand hygiene is the cornerstone of infection prevention and control practices, and reduces healthcare-associated infections significantly. However, international evidence suggests that medical doctors demonstrate poor compliance.

AIM

To explore and compare practices and attitudes towards hand hygiene, particularly hand rubbing using alcohol-based hand rub (ABHR), among hospital-based physicians in Ireland between 2007 and 2015.

METHODS

In 2007, a random sample of doctors in a large teaching hospital was invited to complete a postal survey using a validated questionnaire. In 2015, the study was replicated among all doctors employed in a university hospital group, including the setting of the original study, using an online survey. Data were analysed using SPSS and Survey Monkey.

FINDINGS

Predominately positive and improving attitudes and practices were found, with 86% of doctors compliant with hand hygiene before patient contact in 2015, compared with 58% in 2007. Ninety-one percent of doctors were compliant after patient contact in 2015, compared with 76% in 2007. In 2015, only 39% of respondents reported that they 'almost always' used ABHR for hand hygiene. However, this represents 13.5% more than in 2007. Stated barriers to use of ABHR included dermatological issues, poor acceptance, tolerance and poor availability of ABHR products.

CONCLUSION

Greater awareness of hand hygiene guidelines and greater governance appear to have had a positive impact on practice. However, despite this, practice remains suboptimal and there is scope for substantial improvement. Continued and sustained efforts are required in order to build on progress achieved since the World Health Organization hand hygiene guidelines were published in 2009.

Minimum lethal concentration of sodium hypochlorite for the amphibian pathogen Batrachochytrium dendrobatidis

Sodium hypochlorite (NaOCl) is the active ingredient in household bleach and is commonly used as a disinfectant to clean equipment contaminated by the amphibian pathogen Batrachochytrium dendrobatidis (Bd) in lab husbandry and field studies. We conducted a series of replicated exposure trials using a single Global Pandemic Lineage Bd isolate from Panama (JEL 310) and concentrations of NaOCl ranging from 0.006% to 0.6% for exposure times ranging from 30 seconds to 15 minutes to determine the minimum lethal concentration of NaOCl for this isolate of Bd. Sodium hypochlorite completely killed Bd at a concentration of 0.03% during a 15-minute exposure time, while 0.12% NaOCl was effective at all exposure times (30s-15min).

Enhanced terminal room disinfection and acquisition and infection caused by multidrug-resistant organisms and Clostridium difficile (the Benefits of Enhanced Terminal Room Disinfection study): a cluster-randomised, multicentre, crossover study

BACKGROUND

Patients admitted to hospital can acquire multidrug-resistant organisms and Clostridium difficile from inadequately disinfected environmental surfaces. We determined the effect of three enhanced strategies for terminal room disinfection (disinfection of a room between occupying patients) on acquisition and infection due to meticillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, C difficile, and multidrug-resistant Acinetobacter.

METHODS

We did a pragmatic, cluster-randomised, crossover trial at nine hospitals in the southeastern USA. Rooms from which a patient with infection or colonisation with a target organism was discharged were terminally disinfected with one of four strategies: reference (quaternary ammonium disinfectant except for C difficile, for which bleach was used); UV (quaternary ammonium disinfectant and disinfecting ultraviolet [UV-C] light except for C difficile, for which bleach and UV-C were used); bleach; and bleach and UV-C. The next patient admitted to the targeted room was considered exposed. Every strategy was used at each hospital in four consecutive 7-month periods. We randomly assigned the sequence of strategies for each hospital (1:1:1:1). The primary outcomes were the incidence of infection or colonisation with all target organisms among exposed patients and the incidence of C difficile infection among exposed patients in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT01579370.

FINDINGS

31 226 patients were exposed; 21 395 (69%) met all inclusion criteria, including 4916 in the reference group, 5178 in the UV group, 5438 in the bleach group, and 5863 in the bleach and UV group. 115 patients had the primary outcome during 22 426 exposure days in the reference group (51·3 per 10 000 exposure days). The incidence of target organisms among exposed patients was significantly lower after adding UV to standard cleaning strategies (n=76; 33·9 cases per 10 000 exposure days; relative risk [RR] 0·70, 95% CI 0·50-0·98; p=0·036). The primary outcome was not statistically lower with bleach (n=101; 41·6 cases per 10 000 exposure days; RR 0·85, 95% CI 0·69-1·04; p=0·116), or bleach and UV (n=131; 45·6 cases per 10 000 exposure days; RR 0·91, 95% CI 0·76-1·09; p=0·303) among exposed patients. Similarly, the incidence of C difficile infection among exposed patients was not changed after adding UV to cleaning with bleach (n=38 vs 36; 30·4 cases vs 31·6 cases per 10 000 exposure days; RR 1·0, 95% CI 0·57-1·75; p=0·997).

INTERPRETATION

A contaminated health-care environment is an important source for acquisition of pathogens; enhanced terminal room disinfection decreases this risk.

FUNDING

US Centers for Disease Control and Prevention.

Rates of iatrogenic ventriculitis before and after the use of an alcohol-impregnated external ventricular drain port cap

Iatrogenic ventriculitis is a potential complication of ventriculostomy drain placement. In this study, an alcohol-impregnated external ventricular drain port cap was added to a standardized ventriculostomy placement bundle. Rates of ventriculitis were reduced postintervention, but this finding did not reach statistical significance.

Perspectives of using of "aseptic" drains for abdominal drainage

AIM

Aim of the study was to evaluate the effectiveness of using different types of drain tubes to prevent and reduce the drain-associated infection rate of abdominal drainage procedures.

MATERIALS AND METHODS

80 cases of used so called "standard", "coladerm" and "chlorhexidine" drain tubes for abdominal drainage were analysed. "Standard" drain tubes were used 35 times and "coladerm" and "chlorhexidine" tubes - 20 and 25 times respectively. There were adopted in different elective and emergency so called "clean", "potentially contaminated" and "contaminated" abdominal surgical procedures. The drain tubes were removed between 2 to 14 days after the operations followed by the bacteriological study in search of bacteria growth on the surface of drainage tubes were examined.

RESULTS

Of all 35 cases of used "standard" drain tubes the bacterial growth was found in 23 cases, that means 65,7%; of 20 cases of drains covered by "coladerm" polymer the bacterial growth was found in 6 cases (30%) and only in 3 cases of 25 cases of drain tubes covered by polymer and "chlorhexidine" were positive, that means 12%. The most interesting data were obtained considering the so called "clean" and "contaminated" operations. After the so called "clean" operations the bacterial growth using "standard" drain tubes was found almost in 50% of cases and in 8,3% of cases using "chlorhexidine" drain tubes. After the "potentially contaminated" and "contaminated" operations the bacterial growth was found in 68,2% using "standard" tubes, and using "coladerm" and "chlorhexidine" drain tubes - in 50% and 16,7% respectively.

CONCLUSIONS

In our limited experience using of new antimicrobial polymeric composites as coatings mean the adhesion of bacteria and formation of biofilm at drainage tubes is prevented, which can significantly reduce the drain-associated infection rate.

KEY WORDS

Abdominal drainage, Bacterial growth, Infection rate.