Background: The burden of hospital-acquired infections (HAIs) equates to 3.5 million cases, resulting in more than 90 000 deaths and 2.5 million disability-adjusted life years (DALYs) across Europe. Biological spills pose infection and safety risks for both patients and staff, so spill management is of strategic importance for containment. There is limited evidence as to the efficacy of spill kits currently in use with regard to infection control management. Aim: To understand the perceptions of health professionals when using different spill kit systems. Data collection involved videos and interviews with simulated patients and health professionals (n=24). Simulated spills/scenarios were used to compare the use of both two standard (incumbent) and BIOPERL+ spill kit interventions. Data analysis was iterative and informed by the Framework Method of Analysis. Findings: The BIOPERL+ kit facilitates rapid identification of the appropriate spill kit to use; locating and understanding instructions in both kit types highlight how individuals learn and absorb information; there were positive views on the efficacy of the granules to absorb blood, urine, faeces and vomit of both kit types; the larger scoop of the BIOPERL+ kit was seen as a benefit, facilitating ease of use; concerns were raised over potential cross-contamination and the environmental impact of plastic components used in the kits. Conclusion: The ‘one size fits all’ of the BIOPERL+ kit identified it as the spill kit to use for all biological spills, whereas choice of the two incumbent kits depended on spill type. Locating and understanding instructions in both kit types highlighted how individuals learn and absorb information differently, which may have implications for clinical practice. Participants perceived that all kits had minimal to strong odour, yet the incumbent kits emitted a chlorine-type odour, potentially posing a health risk. The BIOPERL+ large scoop size was seen as more efficacious for spillage containment compared with the smaller plastic scoop of the incumbent kits. Participants also perceived that the incumbent kits could be a source of potential cross-contamination when reusing component parts. The cardboard materials used in the BIOPERL+ kit were perceived as a benefit, potentially having less of an impact on the environment. The study identified that the BIOPERL+ kit is an effective, safe novel intervention that is both appropriate for managing human spills and environmentally friendly.
Candida auris and Staphylococcus aureus are associated with a wide range of infections, as they exhibit multidrug resistance - a growing health concern. In this study, gaseous ozone, and ultraviolet-C (UVC) radiation are applied as infection control measures to inactivate dry biofilms of these organisms on polystyrene surfaces. The dosages utilised herein are 1000 and 3000 ppm.min for ozone and 2864 and 11592 mJ.cm(-2) for UVC. Both organisms showed an increased sensitivity to UVC relative to ozone exposure in a bespoke decontamination chamber. While complete inactivation of both organisms (>7.5 CFU log) was realized after 60 mins of UVC application, this could not be achieved with ozonation for the same duration. However, a combined application of ozone and UVC yielded complete inactivation in only 20 mins. For both treatment methods, it was observed that dry biofilms of S. aureus were more difficult to inactivate than dry biofilms of C. auris. Compared to dry biofilms of C. auris, micrographs of wet C. auris biofilms revealed the presence of an abundance of extracellular material after treatments. Interestingly, wet biofilms were more difficult to inactivate than dry biofilms. These insights are crucial to preventing recalcitrant and recurrent infections via contact with contaminated polymeric surfaces. [GRAPHICS]
The growth and attachment of highly resistant biofilms on/to polymer-based surfaces, including reusable medical devices is a significant health concern in infection control. The increasing prevalence of the multidrugresistant yeast, Candida auris, has recently garnered immense interest as a contributor to healthcare-associated infections. In this study, we investigate the potential of disinfection processes (ozone, UVC, and ozone + UVC) to inactivate C. auris biofilms (NCPF 8971), grown on polystyrene surfaces. A bespoke decontamination chamber is used to expose the substrate for 20-60 mins, corresponding to ozone doses between 1000 and 3000 ppm.min and UVC doses between 2864 and 11,592 mJ/cm(2), respectively. The performance of these 3 treatment methods against the biofilms and vegetative/planktonic cells of the organism is comparatively evaluated. While complete inactivation (> 8 log(10) reduction, CFU/mL) of the vegetative cells is observed within 40 mins by all methods, the biofilms proved considerably difficult to inactivate. Only 3.3 log(10) reduction was achieved using ozone for 40 min, whereas 7.2 log(10) reduction was obtained using UVC for 40 min. A hybrid application of ozone and UVC improved the decontamination efficacy compared to their independent applications (i.e., ozone only and UVC only). Scanning electron microscopy results yielded new insights into the inactivation mechanisms; thus providing the needed foundation for newer developments in oxidation-based processes for biofilm mitigation and control.
The human defensins are a group of cationic antimicrobial peptides that range in size from 2 to 5 kDa and share a common structural motif of six disulphide-linked cysteines. Several naturally occurring human α- and β-defensins have been identified over the past two decades. They have a wide variety of antimicrobial effects, and their potential to avoid the development of resistance to antimicrobial treatment makes them attractive as therapeutic agents. Human defensins have recently been the focus of medical and molecular biology studies due to their promising application in medicine and the pharmaceutical industry. This work aims to provide a comprehensive summary of the current developments of human defensins, including their identification, categorization, molecular features, expression, modes of action, and potential application in medical settings. Current obstacles and future opportunities for using human defensins are also covered. Furthermore, we shed light on the potential of this class as an antiviral agent, particularly against SARS CoV-2, by providing an in silico-based investigation of their plausible mechanisms of action.
BackgroundBiofilms on dry hospital surfaces can enhance the persistence of microorganisms on dry harsh clinical surfaces and can potentially act as reservoirs of infectious agents on contaminated surfaces.AimThis study was conducted to quantify the transfer of viable Staphylococcus aureus cells from dry biofilms through touching and to investigate the impact of nutrient and moisture deprivation on virulence levels in S. aureus.MethodsDry biofilms of S. aureus ATCC 25923 and a defective biofilm-forming ability mutant, S. aureus 1132 were formed in 24 well plates under optimised conditions mimicking dry biofilm formation on clinical surfaces. Microbial cell transfer was induced through the touching of the dry biofilms, which were quantified on nutrient agar. To investigate the impact of nutrient and moisture deprivation on virulence levels, dry and standard biofilms as well as planktonic cells of S. aureus ATCC 25923 were inoculated into Galleria mellonella and their kill rates compared.Findings & ConclusionResults of this study showed that viable cells from dry biofilms of S. aureus ATCC 25923 were significantly more virulent and readily transferrable from dry biofilms through a touch test, therefore representing a greater risk of infection. The biofilm-forming capability of S. aureus strains had no significant impact on their transferability with more cells transferring when biofilm surfaces were wet. These findings indicate that dry biofilms on hospital surfaces may serve as a reservoir for the dissemination of pathogenic microorganisms in hospitals, thus highlighting the importance of regular cleaning and adequate disinfection of hospital surfaces.
Pseudomonas aeruginosa is a growing concern in healthcare associated infections and poses significant risk to those with serious underlying health conditions. The antimicrobial resistance traits of the pathogen and ability to form biofilms make effective mitigation and disinfection strategies difficult. Added to this challenge is the role that free-living amoebae such as Acanthamoeba play in the detection, disinfection, and transmission of P. aeruginosa. P. aeruginosa can survive intracellularly within amoebae, which has the potential to limit detectability and permit transmission into high-risk areas. Herein, we have screened for the presence of Acanthamoeba species and P. aeruginosa within a functioning general hospital in Scotland using a culture and molecular approach, noting their presence at several sites over a 4-month period, particularly within floor drains connecting patient rooms. In addition, microbiome analysis revealed amoebae harbour a unique microbial community comprised primarily of Pseudomonas species that were not readily detected using microbiome sequencing techniques on environmental swabs. Having demonstrated that both organisms were consistently present in hospital settings, we investigated the relationship between Acanthamoeba and P. aeruginosa in the laboratory, showing that i) Acanthamoeba growth rate is increased in the presence of Pseudomonas biofilms and viable Pseudomonas persist within the amoebae and ii) hydrogen peroxide-based disinfectants are significantly less effective against an isolate of P. aeruginosa in the presence of Acanthamoeba than when the bacteria are incubated alone. These findings suggest that amoebae, and other protists, can influence the detection and persistence of P. aeruginosa in high-risk areas and should be considered when implementing mitigation strategies.
Abstract Background The infamous multidrug-resistant (MDR) bacterium Acinetobacter baumannii is becoming a nightmare in intensive care units across the globe. Since there are now very few effective antimicrobial agents, it is necessary to explore unconventional resources for novel antimicrobials. This study investigated the potential antimicrobial activity of Origanum majorana L. against A. baumannii employing multiple approaches including antimicrobial susceptibility, fractionation, ultra-performance liquid chromatography–high-resolution mass spectrometry (UPLC-HRMS) dereplication, and in silico analysis for target/ligand identification. Results On the extremely pathogenic MDR strain A. baumannii AB5075, O. majorana L. has shown a significant growth inhibitory effect (MIC = 0.675 mg/mL). The polar 50% methanol fraction was the most active (MIC = 0.5 mg/mL). The UPLC-HRMS dereplication of the bioactive fraction detected 29 metabolites belonging to different chemical classes. Justicidin B, one of the identified metabolites, was projected by preliminary in silico analysis to be the most highly scoring metabolite for binding with molecular targets in A. baumannii with a Fit score = 8.56 for enoyl-ACP reductase (FabI) (PDB ID: 6AHE), suggesting it to be its potential target. Additionally, docking, molecular dynamics simulation, and bioinformatics analysis suggested that this interaction is similar to a well-known FabI inhibitor. The amino acids involved in the interaction are conserved among different MDR A. baumannii strains and the effectiveness could extend to Gram-negative pathogens within the ESKAPE group. Conclusions Origanum majorana L. extract exhibits antimicrobial activity against A. baumannii using one or more metabolites in its 50% methanol fraction. The characterized active metabolite is hypothesized to be justicidin B which inhibits the growth of A. baumannii AB5075 via targeting its fatty acid synthesis.
Recent evidence indicates that microbial biofilm aggregates inhabit the lungs of COPD patients and actively contribute towards chronic colonization and repeat infections. However, there are no contextually relevant complex biofilm models for COPD research. In this study, a meta‐analysis of the lung microbiome in COPD was used to inform development of an optimized biofilm model composed of genera highly associated with COPD. Bioinformatic analysis showed that although diversity matrices of COPD microbiomes were similar to healthy controls, and internal compositions made it possible to accurately differentiate between these cohorts (AUC = 0.939). Genera that best defined these patients included Haemophilus , Moraxella and Streptococcus. Many studies fail to account for fungi; therefore, Candida albicans was included in the creation of an interkingdom biofilm model. These organisms formed a biofilm capable of tolerating high concentrations of antimicrobial therapies with no significant reductions in viability. However, combined therapies of antibiotics and an antifungal resulted in significant reductions in viable cells throughout the biofilm (p < 0.05). This biofilm model is representative of the COPD lung microbiome and results from in vitro antimicrobial challenge experiments indicate that targeting both bacteria and fungi in these interkingdom communities will be required for more positive clinical outcomes.
Ozone - a powerful antimicrobial agent, has been extensively applied for decontamination purposes in several industries (including food, water treatment, pharmaceuticals, textiles, healthcare, and the medical sectors). The advent of the COVID-19 pandemic has led to recent developments in the deployment of different ozone-based technologies for the decontamination of surfaces, materials and indoor environments. The pandemic has also highlighted the therapeutic potential of ozone for the treatment of COVID-19 patients, with astonishing results observed. The key objective of this review is to summarize recent advances in the utilisation of ozone for decontamination applications in the above-listed industries while emphasising the impact of key parameters affecting microbial reduction efficiency and ozone stability for prolonged action. We realise that aqueous ozonation has received higher research attention, compared to the gaseous application of ozone. This can be attributed to the fact that water treatment represents one of its earliest applications. Furthermore, the application of gaseous ozone for personal protective equipment (PPE) and medical device disinfection has not received a significant number of contributions compared to other applications. This presents a challenge for which the correct application of ozonation can mitigate. In this review, a critical discussion of these challenges is presented, as well as key knowledge gaps and open research problems/opportunities.
Introduction This study aimed to quantify the impact of the COVID-19 pandemic on access and inequalities in primary care dental services among children and adults in Scotland. Methods Access was measured as any NHS Scotland primary care dental contacts derived from administrative data from January 2019 to May 2022, linked to the area-based Scottish Index of Multiple Deprivation for children and adults, and related to population denominator estimates from National Record Scotland. Inequalities for pre-pandemic (January 2019-January 2020) and recent (December 2021-February 2022, and March 2022-May 2022) periods for both children and adults were calculated and compared using the slope index of inequality and relative index of inequality. Results Following the first lockdown (March 2020) there was a dramatic fall to near zero dental contacts, followed by a slow recovery to 64.8% of pre-pandemic levels by May 2022. There was initial widening of relative inequalities in dental contacts in early 2022, which, more recently, had begun to return to pre-pandemic levels. Conclusion COVID-19 had a major impact on access to NHS primary dental care, and while inequalities in access are apparent as services recover from lockdown, these inequalities are not a new phenomenon.
The utilization of gaseous ozone (a powerful oxidant) in air, for disinfection and sterilization purposes, has been extensively studied for diverse applications; however, the optimal deployment of this technology for textile disinfection is deserving of further research attention and is this the focus of this work. In this study, the penetration efficiency of ozone gas into hard-to-reach regions of different garment types is critically examined. The impacts of garment packing density, hanging orientation and ozonation duration are also considered, and the resultant disinfection efficiencies are comparatively analyzed. An ozonation chamber fitted with remote ozone detection is utilized for the ozonation of fabric swatches inoculated with Escherichia coli bacteria. The number of colony-forming units per cm2 and the bacterial lawn area fraction are evaluated pre- and post-ozonation to quantify the level of disinfection. This study shows that the attainment of sufficient ozone concentrations in hard-to-reach regions of different garment types coupled with the inter-garment spacing utilized are vital for effective decontamination. This study also demonstrates the effectiveness of ozonation as a necessary technology for decontamination, particularly in this era, where the sterilization of textiles and other materials is paramount for public health and safety.
BACKGROUND:In Arabic countries, no research has focused on the experience of patients with indwelling urinary catheters. This cross-sectional study is the first to evaluate the catheter-specific quality of life (QoL) of patients living with a urinary catheter in Egypt.METHODS:This study was conducted from April to September 2017, using a convenience sample of patients from a University Hospital. Data were collected using the International Consultation on Incontinence Questionnaire-Long-Term Catheter QoL (ICIQ-LTCQoL) instrument, along with a demographic datasheet.RESULTS:141 were enrolled, with 47.5% inpatients, 52.5% outpatients. A total of 70.9% reported problems with catheter function, and 92.2% reported that the catheter affected their daily lives. Place (inpatient or outpatient) was significantly associated with the total score of the ICIQ-LTCQoL (mean difference (MD) 6.34 (95% CI: 3.0 to 9.73)) and both subscales (catheter function subscale: MD = 4.92 (95% CI: 2.12 to 7.73) and lifestyle impact subscale: MD = 1.44 (95% CI: 0.3 to 2.63)), suggesting that outpatients have poorer QoL than inpatients. Moreover, catheter material was significantly related to the catheter function domain with Silicone Foley Catheter (100% Silicon) users experiencing poorer QoL related to catheter function than those with Latex Foley Catheter (Silicon-coated) (MD 4.43 (95% CI: 0.62 to 8.24). Workers/employees were found to have poorer QoL than those who were retired (MD = 4.94 (95% CI: 0.3 to 9.63)).CONCLUSION:The results highlight the necessity of assessing function and concern regarding urinary catheter use and its impact on QoL, as well as its determinants. Evidence-based educational programs should be designed to enhance patients' self-care abilities to relieve their sense of distress and enhance their confidence in caring for their catheters.
With the advent of the COVID-19 pandemic, there has been a global incentive for applying environmentally sustainable and rapid sterilization methods, such as ultraviolet-C radiation (UVC) and ozonation. Material sterilization is a requirement for a variety of industries, including food, water treatment, clothing, healthcare, medical equipment, and pharmaceuticals. It becomes inevitable when devices and items like protective equipment are to be reused on/by different persons. This study presents novel findings on the performance of these sterilization methods using four microorganisms (Escherichia coli , Staphylococcus aureus , Candida albicans , and Aspergillus fumigatus) and six material substrates (stainless steel, polymethyl methacrylate, copper, surgical facemask, denim, and a cotton-polyester fabric). The combination of both ozone and UVC generally yields improved performance compared to their respective applications for the range of materials and microorganisms considered. Furthermore, the effectiveness of both UVC and ozone was higher when the fungi utilized were smeared onto the nonabsorbent materials than when 10 μL droplets were placed on the material surfaces. This dependence on the contaminating liquid surface area was not exhibited by the bacteria. This study highlights the necessity of adequate UVC and ozone dosage control as well as their synergistic and multifunctional attributes when sterilizing different materials contaminated with a wide range of microorganisms.
For decades, ozone has been known to have antimicrobial properties when dissolved or generated in water and when utilized in its gaseous form on different substrates. This property (the ability to be used in air and water) makes it versatile and applicable to different industries. Although the medium of ozonation depends on the specific process requirements, some industries have the inherent flexibility of medium selection. Thus, it is important to evaluate the antimicrobial efficacy in both media at similar concentrations, an endeavor hardly reported in the literature. This study provides insights into ozone's efficacy in air and water using two Gram-negative bacteria (Escherichia coli NTCC1290 and Pseudomonas aeruginosa NCTC10332), two Gram-positive bacteria (Staphylococcus aureus ATCC25923 and Streptococcus mutans), and two fungi (Candida albicans and Aspergillus fumigatus). For gaseous ozonation, we utilized a custom-made ozone chamber (equipped with ultraviolet lamps), whereas an electrolysis oxygen radical generator was applied for ozone generation in water. During gaseous ozonation, the contaminated substrates (fabric swatches inoculated with bacterial and fungal suspensions) were suspended in the chamber, whereas the swatches were immersed in ozonated water for aqueous ozone treatment. The stability of ozone nanobubbles and their resulting impact on the aqueous disinfection efficiency were studied via dynamic light scattering measurements. It was observed that ozone is more effective in air than in water on all tested organisms except Staphylococcus aureus. The presented findings allow for the adjustment of the treatment conditions (exposure time and concentration) for optimal decontamination, particularly when a certain medium is preferred for ozonation.
Background The COVID-19 pandemic led to significant changes in the provision of dental services, aimed at reducing the spread of respiratory pathogens through restrictions on aerosol generating procedures (AGPs). Evaluating the risk that AGPs pose in terms of SARS-CoV-2 transmission is complex, and measuring dental aerosols is challenging. To date, few studies focus on intra-oral suction. This study sought to assess the effectiveness of commonly used intra-oral suction devices on aerosol mitigation. Methods Ultrasonic scaling and high-speed handpiece procedures were undertaken to generate aerosol particles. Multiple particle sensors were positioned near the oral cavity. Sensor data were extracted using single board computers with custom in-house Bash code. Different high-volume and low-volume suction devices, both static and dynamic, were evaluated for their efficacy in preventing particle escape during procedures. Results In all AGPs the use of any suction device tested resulted in a significant reduction in particle counts compared with no suction. Low-volume and static suction devices showed spikes in particle count demonstrating moments where particles were able to escape from the oral cavity. High-volume dynamic suction devices, however, consistently reduced the particle count to background levels, appearing to eliminate particle escape. Conclusions Dynamic high-volume suction devices that follow the path of the aerosol generating device effectively eliminate aerosol particles escaping from the oral cavity, in contrast to static devices which allow periodic escape of aerosol particles. Measuring the risk of SARS-CoV-2 transmission in a dental setting is multi-factorial; however, these data suggest that the appropriate choice of suction equipment may further reduce the risk from AGPs.
In current times of increasing global decontamination concerns, sustainable and environmentally-friendly technologies that possess rapid and effective disinfection capabilities are necessary for public health and safety. In this study, we evaluate the potential of ozone-based technology to reveal its immense potential in disinfection applications. Ozonated water generated by an electrolytic method was utilised to quantify ozone retention as a function of mineralogical composition for microbial decontamination. The impacts of temperature and detergent concentration on ozone concentration are critically analysed, as well as ozone’s decomposition and stain removal characteristics. In addition, fabric swatches inoculated with known concentrations of environmental microbes (Escherichia coli, Staphylococcus aureus, Candida albicans, and Aspergillus fumigatus) are washed with ozonated water to ascertain the impact of wash duration on bacterial removal efficiency. The results show significant improvement in the stability and retention potential of ozone in mineral water at low temperature and in the presence of a detergent. The experiments demonstrate first-order decomposition kinetics of ozone in aqueous formulations. The disinfection potency of ozone is also substantiated by a significant removal of microbiota on the fabric utilised (up to 7 log reduction for the bacteria analysed), thus making it effective for sterilisation applications. This also reduces the need for toxic chemicals or chemicals with toxic by-products (e.g., chlorine) for large-scale decontamination operations in various industries.
Ozone treatment is an eco-friendly and cost-effective approach to achieve material disinfection, and this disinfection method is of utmost importance in the present global pandemic. The efficacy of ozone's oxidative potential on common microorganisms has been extensively studied, particularly in the food and water treatment industries. However, little is still understood regarding its antimicrobial capabilities for the treatment of textile substrates in air. In this study, fabric swatches inoculated with bacterial and fungal suspensions are exposed to ozone for different durations and at different ozone concentrations. Pathogenic bacteria (Escherichia coli, Staphylococcus aureus), and fungi (Aspergillus fumigatus, and Candida albicans), are the microbes utilised in this study. The efficacy of ozone is demonstrated by the complete removal of microbiota on the tested swatches when a concentration and exposure duration of 20 ppm and 4 mins are respectively maintained in a test ozone chamber. We expect the insights from this work to guide the development of new ozonation techniques capable of rapid sterilisation in industrial & public settings.
(p=4.3x10 -4 ), respectively. Fatty acid binding protein 4 (FABP4) and CD44, involved in surfactant regulation, were decreased in COPD, log2FC of -0.4 (p=8.0x10 -3 ) and -0.7 (p=1.1x10 -5 ), respectively. Histamine and hypoxanthine metabolites were increased in COPD, log2FC of 0.8 (p=2.5x10 -2 ) and 1.0 (p=4.0x10 -2 ), respec-tively, which could indicate immune-dysregulation and inflam-mation. Surfactant lipid levels were decreased in COPD, specifically, PC, PG, and PI, log2FC of -2.1 (p=2.6×10 -7 ), -2.4 (p=5.3×10 -8 ) and -1.5 (p=9.0×10 -6 ), respectively. Conclusions We used a multiomics approach to comprehensively describe surfactant dysregulation in a well-characterised COPD cohort, with an aim to generate novel insights into key aspects of this biology within the COPD lung. Further mechanistic studies could help to understand the role this plays in pathological mechanisms and allow novel therapeutic target identification.
Haemophilus influenzae is the most common cause of bacterial infection in the lungs of chronic obstructive pulmonary disease (COPD) patients and contributes to episodes of acute exacerbation which are associated with increased hospitalization and mortality. Due to the ability of H. influenzae to adhere to host epithelial cells, initial colonization of the lower airways can progress to a persistent infection and biofilm formation. This is characterized by changes in bacterial behaviour such as reduced cellular metabolism and the production of an obstructive extracellular matrix (ECM). Herein we discuss the multiple mechanisms by which H. influenzae contributes to the pathogenesis of COPD. In particular, mechanisms that facilitate bacterial adherence to host airway epithelial cells, biofilm formation, and microbial persistence through immune system evasion and antibiotic tolerance will be discussed.