Cleaning Protocol Research Articles

Microbial Contamination Risk and Disinfection of Radiation Protective Garments.

Healthcare-associated infections are a major public health concern for both patients and medical personnel. This has taken on greater urgency during the current COVID-19 pandemic. Radiation Personal Protective Equipment (RPPE) may contribute to risks of microbial contamination. This possibility was tested in 61 personal or shared-use lead aprons and thyroid collars at Columbia Presbyterian Irving Medical Center. Fifty percent tested positive for either bacterial or fungal contamination, mostly around the neckline of lead vests and thyroid collars. Repeated testing of garments some weeks to months later confirmed continued presence of microbial contamination. The possibility that hospital-approved disinfection agents could degrade the radio-protective features of these garments was also examined. Samples of identical construction to garments in regular use were subjected to either daily or weekly wipes with hypochlorite or alcohol-based hospital-approved cleaning agents for 6 mo. A third group of samples was maintained in contact with the cleaning agents for 6 mo. All samples were fluoroscoped four times during the study. None demonstrated any degradation in radioprotection. All samples were photographed monthly. Physical degradation of the outer plastic covering by concentrated hypochlorite and limited mechanical damage around stitched seams of the samples cleaned daily with alcohol was noted. Based on the high prevalence of microbial contamination, regular cleaning and disinfection protocols should be implemented. Regular cleaning with medical-facility-approved cleaning and disinfecting agents is likely to be effective at reducing the microbial load and unlikely to result in significant reduction in radioprotective properties of these garments.

A Critical Review of Disinfection Processes to Control SARS-CoV-2 Transmission in the Food Industry.

Industries of the food sector have made a great effort to control SARS-CoV-2 indirect transmission, through objects or surfaces, by updating cleaning and disinfection protocols previously focused on inactivating other pathogens, as well as food spoilage microorganisms. The information, although scarce at the beginning of the COVID-19 pandemic, has started to be sufficiently reliable to avoid over-conservative disinfection procedures. This work reviews the literature to propose a holistic view of the disinfection process where the decision variables, such as type and concentration of active substances, are optimised to guarantee the inactivation of SARS-CoV-2 and other usual pathogens and spoilage microorganisms while minimising possible side-effects on the environment and animal and human health.

114 - Hype the Wipe! a Clean Protocol to Stop the Spread of Clostridium Difficile on a Hematopoietic Stem Cell Transplant Unit

114 - Hype the Wipe! a Clean Protocol to Stop the Spread of Clostridium Difficile on a Hematopoietic Stem Cell Transplant Unit

Reappraising Elements of the Aseptic Technique in Dermatology: A Review.

Dermatologic procedures are performed under varying degrees of antisepsis, and no clear guidelines exist regarding the role of the aseptic technique in dermatology. This review aims to clarify the terminology surrounding surgical asepsis and examines the importance of various components of the aseptic technique in cutaneous surgery. Included are studies examining optimal glove type, surgical instruments, skin antisepsis, and cost-reducing protocols. Our review highlights that most dermatology procedures are not performed under completely sterile conditions due to the lack of environmental and foot traffic controls in dermatology offices. In addition, for some outpatient procedures, such as for minor excisions and Mohs surgery before reconstruction, elements of the clean technique can be used without increasing infection rates. However, data on the feasibility of a clean protocol for Mohs reconstruction is conflicting. Future prospective, randomized trials analyzing various components of the aseptic technique in dermatology are greatly needed so that guidelines can be established for practicing dermatologists.

Combining pulsed xenon ultraviolet disinfection with terminal manual cleaning helps reduce the acquisition rate of methicillin-resistant Staphylococcus aureus

The clinical effectiveness of ultraviolet light (UV) disinfection remains unclear. This study aimed to investigate the effect of adding pulsed xenon UV (PX-UV) disinfection to the terminal cleaning protocol on the rate of methicillin-resistant Staphylococcus aureus (MRSA) acquisition at a Japanese hospital. The use of a PX-UV disinfection device was added to the manual terminal cleaning protocol applied after the discharge or transfer of patients treated in the intensive and high care units. We used a Poisson regression model to examine the incidence of MRSA acquisition, based on the study period, PX-UV intervention status, unit type, and the rate of consumption of alcohol-based hand rub (ABHR). Approximately 86% of the rooms in the intervention units were terminally disinfected with the PX-UV device. In the intervention units, the incidence of MRSA acquisition decreased from 3.56 per 1,000 patient-days in the nonintervention period to 2.21 per 1,000 patient-days in the intervention period. Moreover, the use of PX-UV disinfection decreased the risk of MRSA acquisition (incident rate ratio: 0.556; 95% confidence interval, 0.309-0.999; P = .0497). ABHR consumption did not affect the risk of MRSA acquisition. Adding PX-UV disinfection to terminal manual cleaning reduced the rate of MRSA acquisition.

Evaluation of cleaning and disinfection protocols for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) on different hospital surfaces.

Since SARS-CoV-2 is able to survive on inanimate surfaces, we analysed samples of several healthcare settings, to carry out a disinfection protocol assessment. Despite the accuracy of strategies set up to increase the effectiveness of the study, none of the samples showed the presence of viral specific RNA fragments.

Environmental Recovery of Nosocomial Bacteria in a Companion Animal Shelter Before and After Infection Control Procedures.

While the effects of cleaning and disinfection practices on the reduction of environmental nosocomial bacteria are well-established in human and large animal veterinary hospitals, how animal movements within animal health care facilities influence environmental bacterial recovery is poorly understood. During three consecutive weeks, 155 electrostatic wipes were collected from the environment pre- and post-cleaning only or following disinfection from seven target locations within an animal shelter. All samples were cultured, and isolates were identified using a matrix-assisted laser desorption ionization—time of flight mass spectrometry. Social network analysis of animal movements during the sampling period was performed to estimate the level of connectivity of the seven target locations. The relationship between bacterial levels and connectivity estimates of the target locations were investigated using a negative binomial regression model with a random effect of sampling areas. Overall, our results indicate a significant reduction in the total bacterial contamination with disinfection when compared to cleaning only [Coefficient (Coef.) = −1.72, 95% Confidence Interval (CI) = −3.09, −0.34, P = 0.015]. Higher total bacterial contamination was significantly more likely in sampled areas with less animal movement connectivity (Coef. = −0.32, 95% CI = −0.49, −0.15, P ≤ 0.001). Pseudomonas aeruginosa and ampicillin resistant Enterobacteriaceae (Escherichia coli, Enterobacter spp. and Klebsiella spp.) were present in the animal holdings and in the shelters' veterinary clinic environment at all sampling times. Our findings demonstrate that cleaning followed by disinfection practices are effective at reducing environmental bacterial levels. Areas with less animal connectivity are more likely to have a higher bacterial contamination. These areas could represent environmental reservoirs for bacterial infection and should be targeted with effective cleaning and disinfection protocols.

Salmonella prevalence and persistence in industrialized poultry slaughterhouses

Salmonella contamination sources and transmission routes were studied in 5 Belgian poultry slaughterhouses. Samples from the slaughter and cutting line after cleaning and disinfection were collected, as well as neck skin samples and thighs during slaughter of the first flock. In total, 680 swab and water samples were taken from the slaughter line before slaughter. In all slaughterhouses, Salmonella was notwithstanding cleaning and disinfection still isolated from the slaughter line before start of activities. The prevalence of Salmonella in the plucking area was 10.4% (38/365) (hanging area: 5.0%, scalding tank: 5.8%, plucking machine: 17.0%); in the evisceration room, 1.5% (2/138); and in the cutting area, 2.0% (3/149). No Salmonella (0/28) was found in samples from the chilling line. On neck skin samples taken from the various lines, Salmonella prevalence was 16.1% (48/299) after plucking, 16.0% (48/300) after evisceration, 23.3% (70/300) after chilling; on thighs, prevalence was 10.0% (24/240). Nine Salmonella serotypes were identified of which Salmonella Infantis was the most common serovar (53.8%), especially in slaughterhouse A. Two contamination causes were identified; first, although all flocks had an official Salmonella negative status, this was in one case incorrect and led to an enormous contamination of the neck skins of the flock and the slaughterline (i.e., cooling water). Second, molecular typing revealed cross-contamination from flocks slaughtered 1 d before sampling. Salmonella was apparently not always eliminated by the cleaning and disinfection process and able to contaminate the carcasses of the first slaughtered flock. In conclusion, the results of this study provided practical insights for poultry production to further improve their Salmonella control, for example, Salmonella status determination closer to the slaughter date, to adapt cleaning and disinfection protocols especially for critical machinery and better hygienic designed equipment.

2-Aminoimidazoles as potent inhibitors of contaminating brewery biofilms

Cleaning and disinfection protocols are not always able to remove biofilm microbes present in breweries, indicating that novel anti-biofilm strategies are needed. The preventive activities of three in-house synthesized members of the 2-aminoimidazole class of anti-biofilm molecules were studied against 17 natural brewery biofilms and benchmarked against 18 known inhibitors. Two 2-aminoimidazoles belonged to the top six inhibitors, which were retested against 12 defined brewery biofilm models. For the three best inhibitors, tannic acid (n° 1), 2-aminoimidazole imi-AAC-5 (n° 2), and baicalein (n° 3), the effect on the microbial metabolic activity was evaluated. Here, the top three inhibitors showed similar effectiveness, with baicalein possessing a slightly higher efficacy. Even though the 2-aminoimidazole was the second-best inhibitor, it showed a lower biocidal activity than tannic acid, making it less prone to resistance evolution. Overall, this study supports the potential of 2-aminoimidazoles as a preventive anti-biofilm strategy.

Cost-Benefit Analysis of Allowing Additional Time in Cleaning Hospital Contact Precautions Rooms

Increasing cleaning time may reduce hospital-acquired transmission of Clostridioides difficile, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococcus (VRE). We constructed a cost-benefit model to estimate the impact of implementing an enhanced cleaning protocol, allowing hospital housekeepers an additional 15 minutes to terminally clean contact precautions rooms. The enhanced cleaning protocol saved the hospital $758 per terminally-cleaned room when accounting for only C. difficile. Scaling up to a hospital with 100 cases of C. difficile/year, and the US annual C. difficile incidence, cost savings were $75,832/year and $169.8 million/year, respectively. These results may inform infection control strategic decision-making and resource allocation.

General Practitioners' Practice premises and Risk of Viral Cross-Transmission: A French Observational Multicenter Study.

Background:The common areas of general practitioners’ practices (eg, reception, secretariat, waiting room, toilets) are places at risk of cross-transmission of viral diseases such as COVID-19, however risk is poorly documented.Aim:To evaluate the risks of viral cross-transmission in general practitioners’ practices based on the organization of the common areas of the premises.Design and setting:Cross-sectional multicenter observational study in randomly selected general practitioners’ practices in a French department (Seine-Maritime). The practices were included in 4 strata (1, 2, 3–5, or ≥6 general practitioners).Method:Each practice was visited and a questionnaire describing practice organization, cleaning of the premises, screening of high-risk patients was completed on site and observation of the premises).Results:Data collection started in December 2019 and was discontinued due to the national lockdown related to the global SARS-CoV-2 pandemic. Eighty-two practices were analyzed. A hydroalcoholic solution was available in 7.3% of practices and surgical masks in 1.2%. In a majority of waiting rooms, the minimum distance between chairs facing each other was >2 m (78.0%), but was more frequently 1 m for chairs at 90° (53.7%). Overall, 79.3% of waiting rooms could be properly ventilated and waste bins were present in 23.9% of cases. A cleaning protocol was reported in 39.2% of practices.Conclusion:The COVID-19 epidemic allowed the national dissemination of standard precautions. It will be interesting to monitor over the next few years whether the renewed consideration of standard precautions to prevent viral cross-contamination will be maintained over time.

Cleaning and Surface Treatment Protocols for Repair of Aged Y-TZP with Composite Resin.

The purpose of this study was to evaluate the cleaning and surface treatment techniques in the repair of aged and contaminated yttrium oxide-stabilized tetragonal polycrystalline zirconia (Y-TZP). From a total of 80 specimens of Y-TZP, 60 were subjected to aging simulation in a buccal environment with degradation in an autoclave for 24 hours (127°C/1.5 bar) and contaminated with Streptococcus mutans. The surfaces were cleaned with a triple syringe (air/water jet; n = 20) or isopropyl alcohol (n = 20), or by prophylaxis (n = 20) with pumice and water. The remaining 20 specimens comprised the control group. All specimens were then treated with silicatization (n = 10 per group) or adhesive (n = 10 per group) and repaired with composite resin. Analyses of shear strength, failure mode, and roughness were performed by electron microscopy. Data were analyzed by two-way analysis of variance (ANOVA) and t test (α = .05). Statistical significance was set at P < .05. Two-way ANOVA was significant for aging and surface treatments (P = .049), but was not significant for surface cleaning (P = .05). ANOVA results were statistically significant for surface treatments (P < .0001), with higher resistance for the silicatization groups. The failure mode was mostly adhesive for all specimens. The roughness was not significant for aging and control groups (P > .05). Triple-syringe and prophylaxis cleansing followed by silicatization was the most efficient treatment for the repair of aged and contaminated Y-TZP. There is reduced repair efficiency with the aging of Y-TZP.

Disinfection of Environmental Surfaces and Articles Used for COVID 19 Patient

Disinfection of environment surfaces and articles used for COVID 19 patient plays an important role in reducing indirect transmission of SARS-CoV-2 – the virus responsible for COVID-19. Depending on the type of surface, SARS-CoV-2 can remain viable between eight hours to several days. The surfaces are contaminated when virus-containing droplets land on surfaces, or when someone with contaminated hands touches these surfaces. Virus contamination in both health care as well as non-health care settings can be reduced by good disinfection practices. Cleaning and disinfection is fundamental because it kills any remaining germs on the surface and thereby reduces the spread of germs. Therefore disinfection of the health care environment is vital in reducing infection rate. Following strict cleaning and disinfection protocols is the key to make sure that the patient as well as the health care worker remains safe. It is also important to increase awareness on how to clean and disinfect the articles used for Covid patient, so that the disease not spread to other patients and at the same time health care workers are protected. The disinfectant and its concentration should be carefully selected to avoid or minimize toxic effects on household members and also avoid damaging surfaces.

Green synthesis of silver nanoparticles from Aloe vera leaf extract and its antimicrobial activity

Abstract Extensive use of nanoparticles attracted an increased interest in sustainable strategies for its synthesis; which can possibly offer additional advantages. Green synthesis from plant source can offer a clean protocol with many additional qualities contributed by the phytocomponents involved in capping of nanoparticles. In this study, we employed the green synthesis of silver nanoparticles (AgNPs) using the inner gel extract of Aloe vera leaf. Characterisation of the green synthesised AgNPs were done from the spectral analysis of UV–Visible spectrophotometer and Fourier transform infrared spectrometer. Visible observation of colour change and UV–Visible absorption spectrum with plasmon peak at 400 nm confirmed the formation of AgNPs. The FTIR spectra suggested the role of the functional groups in acemannan, the major bioactive polysaccharide of Aloe vera gel, in the formation of AgNPs by acting as a reducing and stabilizing agent. The disc diffusion study indicated an increased antimicrobial activity for green synthesised AgNPs against gram positive Staphylococcus aureus and gram negative Escherichia coli, Pseudomonas aeruginosa and Enterobacter sps. This synergic effect of AgNPs and phytocomponents involved in its capping against the microbes indicates the influence of particle parameters like capping components on the activity of AgNP. These observations open up new possibilities for exploiting Aloe vera gel extract mediated AgNPs in many biomedical applications.

Preferential Loss of High Trace Element Bearing Inner Calcite in Foraminifera During Physical and Chemical Cleaning

AbstractTrace elements (TEs) in the calcite shells of foraminifera are widely used in paleoceanographic reconstructions. Nearly all TE analytical protocols include cleaning to remove contaminant phases. Understanding, how the TE composition is altered during physical and chemical cleaning is of utmost importance in ensuring the accuracy of paleoclimate reconstructions. Aggressive cleaning steps that include corrosive reagents are commonly used to clean shells with elevated Ba/Ca and Mn/Ca ratios, under the assumption that these elements are elevated due to diagenetic overprinting. We provide evidence that elevated intrashell Ba/Ca, Mn/Ca, and Zn/Ca ratios are lattice bound and a primary signal incorporated into inner calcite during calcification in the nonspinose species Neogloboquadrina dutertrei and Pulleniatina obliquiloculata. We first demonstrate, using laser ablation depth profiling analyses, that aggressive cleaning following the full cleaning protocol traditionally used to eliminate Mn and Ba contamination, preferentially removes inner (ontogenic) calcite and favors the low Ba/Ca, Mn/Ca, Zn/Ca, and Mg/Ca crust/cortex calcite. In a separate experiment, we demonstrate that mechanical fragmentation of bulk shells prepared for solution analysis also preferentially removes inner calcite and favors the low TE crust/cortex calcite. Preferential loss of the ontogenic calcite decreases Ba/Ca, Mn/Ca, and Zn/Ca ratios by 50%–90% in N. dutertrei and P. obliquiloculata shells. This biases foraminiferal TE results toward lower values and may yield data that is problematic for the interpretation of downcore records.

Clean protocol for deoxygenation of epoxides to alkenes via catalytic hydrogenation using gold

Au NP catalyst combined with triethylphosphite, P(OEt)3, is remarkably more reactive than solely Au NPs for the selective deoxygenation of epoxides to alkenes.

787. Evaluation of Clostridioides difficile Environmental Contamination Surrounding C. difficile Patients vs. non-C. difficile Patients in Outpatient Infusion Centers

Background Clostridioides difficile infection (CDI) is the most common cause of healthcare-associated infection. CDI and non-CDI patients (pts) are often treated at the same time in outpatient infusion centers (OICs). This proximity may allow horizontal transfer of spores. However, C. difficile (C. diff) spores are ubiquitous in nature and baseline contamination rates at OICs are unknown. The purpose of this pilot study was to determine toxigenic C. diff contamination in the OIC surrounding CDI pts receiving bezlotoxumab compared to non-CDI pts receiving another infusion in the same OIC before and after cleaning.MethodsOIC contamination rates were assessed at baseline, after infusion and after cleaning the environment of CDI pts receiving bezlotoxumab compared to non-CDI pts receiving other infusions. For each pt receiving an infusion, 11 areas were sampled at each time period; the infusion chair (n=4), medical and non-medical equipment (n=3), and the floor surrounding the infusion chair (n=4). Five high traffic control areas per sampling day were included. Swabs were cultured anaerobically and PCR was used to identify toxin genes. Proportion of toxigenic C. diff positive samples were compared between CDI and non-CDI pts for each time point. Cleaning was performed using a standard protocol of bleach (CDI pt) or non-bleach (non-CDI pt) products.ResultsSamples (n=709) were obtained from 10 pts in each group (329 CDI, 330 non-CDI, 50 high-traffic) from 7 OICs over 4 months. Overall, 55 patient area cultures (8%) were positive for C. diff. Positive sampling areas were highest for floors (13%) followed by infusion chairs (7%) and equipment (4%). Baseline contamination in high traffic areas was 6%. Contamination rates (Table 1) for CDI were 7% at baseline, higher after infusion (15%) and lower after cleaning (5%). For non-CDI pts, rates were similar at baseline (8%), after infusion (6%) and after cleaning (9%).Table 1. Proportion of toxigenic C. difficile-positive samples in the environment of CDI and non-CDI patients. ConclusionCompared to non-CDI pts, CDI pts had similar baseline but lower after cleaning contamination rates. These preliminary results suggest that with a proper cleaning protocol in place, the presence of CDI patients in an OIC does not increase the likelihood of C. diff transmission for other at-risk populations.Disclosures Kevin W. Garey, PharmD, MS, FASHP, Merck & Co. (Grant/Research Support, Scientific Research Study Investigator) Richard L. Hengel, MD, Merck & Co. (Other Financial or Material Support, Grant Steering Committee Member) Timothy E. Ritter, MD, Merck & Co. (Other Financial or Material Support, Grant Steering Committee Member) Ramesh V. Nathan, MD, FIDSA, Merck & Co. (Other Financial or Material Support, Grant Steering Committee Member) Engels N. Obi, PhD, Merck & Co. (Employee) Lucinda J. Van Anglen, PharmD, Merck & Co. (Grant/Research Support)

Two novel protocols for cleaning residual simethicone and fluid in patient‐ready duodenoscopes

Approximately 42-95% of working channels have been reported to show the presence of residual fluid despite endoscope reprocessing. The aim of this study was to design two novel protocols for cleaning residual simethicone and demonstrate its efficiency by evaluating the residual fluid and cleanliness in the working channels of patient-ready duodenoscopes. The designed protocol for cleaning residual simethicone was implemented in manual cleaning and/or high-level disinfection (HLD). The residual fluid inside the working channels was estimated by visual inspection. Adenosine triphosphate (ATP) values were evaluated to determine cleanliness after manual cleaning. Manual cleaning with novel simethicone cleaning protocol demonstrated a significant decrease in fluid droplets (14.6±29.9 vs 0±0, P<0.001) and ATP values (157±196 relative light units [RLUs] vs 52±41 RLUs, P=0.031). HLD with simethicone cleaning protocol, using either enzymatic detergent with effective for cleaning simethicone or cleaning time set in the automatic endoscope reprocessor program for 8min, demonstrated significant decrease in the number of fluid droplets. Follow-up after the implementation of the simethicone cleaning protocol showed a significant decrease in fluid droplets (37.4±41.0 vs 2.1±5.5, P=0.003) and ATP values (271±268 RLUs vs 82±136 RLUs, P=0.021). Simethicone cleaning protocol is advantageous for significantly decreasing fluid droplets and ATP values within endoscope working channels. After manual cleaning with the simethicone cleaning protocol, in particular, no retained fluid droplet was observed in patient-ready duodenoscopes.

An Improved Cleaning Protocol for Foraminiferal Calcite from Unconsolidated Core Sediments: HyPerCal—A New Practice for Micropaleontological and Paleoclimatic Proxies

Paleoclimatic and paleoceanographic studies routinely rely on the usage of foraminiferal calcite through faunal, morphometric and physico-chemical proxies. The application of such proxies presupposes the extraction and cleaning of these biomineralized components from ocean sediments in the most efficient way, a process which is often labor intensive and time consuming. In this respect, in this study we performed a systematic experiment for planktonic foraminiferal specimen cleaning using different chemical treatments and evaluated the resulting data of a Late Quaternary gravity core sample from the Aegean Sea. All cleaning procedures adopted here were made on the basis of their minimum potential bias upon foraminiferal proxies, such as the faunal assemblages, degree of fragmentation, stable isotope composition (δ18O and δ13C) and/or Mg/Ca ratios that are frequently used as proxies for surface-ocean climate parameters (e.g., sea surface temperature, sea surface salinity). Six different protocols were tested, involving washing, sieving, and chemical treatment of the samples with hydrogen peroxide and/or sodium hexametaphosphate (Calgon®). Single species foraminifera shell weighing was combined with high-resolution scanning electron microscopy (SEM) and synchrotron X-ray microtomography (SμCT) of the material processed by each of the cleaning protocols, in order to assess the decontamination degree of specimen’s ultrastructure and interior. It appeared that a good compromise between time and cleaning efficiency is the simultaneous treatment of samples with a mixed hydrogen peroxide and Calgon solution, while the most effective way to almost completely decontaminate the calcareous components from undesirable sedimentary material is a two-step treatment—initially with hydrogen peroxide and subsequently with Calgon solutions.

Machine Learning Approaches for Detecting Parkinson’s Disease from EEG Analysis: A Systematic Review

Background: Diagnosis of Parkinson’s disease (PD) is mainly based on motor symptoms and can be supported by imaging techniques such as the single photon emission computed tomography (SPECT) or M-iodobenzyl-guanidine cardiac scintiscan (MIBG), which are expensive and not always available. In this review, we analyzed studies that used machine learning (ML) techniques to diagnose PD through resting state or motor activation electroencephalography (EEG) tests. Methods: The review process was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All publications previous to May 2020 were included, and their main characteristics and results were assessed and documented. Results: Nine studies were included. Seven used resting state EEG and two motor activation EEG. Subsymbolic models were used in 83.3% of studies. The accuracy for PD classification was 62–99.62%. There was no standard cleaning protocol for the EEG and a great heterogeneity in the characteristics that were extracted from the EEG. However, spectral characteristics predominated. Conclusions: Both the features introduced into the model and its architecture were essential for a good performance in predicting the classification. On the contrary, the cleaning protocol of the EEG, is highly heterogeneous among the different studies and did not influence the results. The use of ML techniques in EEG for neurodegenerative disorders classification is a recent and growing field.