-
International Journal of Environmental... May 2023We assessed the disinfection efficacy of an ozone generator prototype in ambulances used to transport patients with coronavirus disease (COVID-19). This research...
We assessed the disinfection efficacy of an ozone generator prototype in ambulances used to transport patients with coronavirus disease (COVID-19). This research consisted of three stages: in vitro tests using microbial indicators, such as and , which were experimentally inoculated onto polystyrene crystal surfaces within a 23 m enclosure. They were then exposed to ozone at a 25 ppm concentration using the ozone generator (Tecnofood SAC) portable prototype, and the decimal reduction time (D) was estimated for each indicator. The second stage involved the experimental inoculation of the same microbial indicators on a variety of surfaces inside conventional ambulances. The third stage consisted of exploratory field testing in ambulances used to transport patients with suspected COVID-19. During the second and third stages, samples were collected by swabbing different surfaces before and after 25 ppm ozonisation for 30 min. Results suggested that ozone was most effective on (D = 2.65 min), followed by (D = 3.14 min), (D = 5.01 min) and (D = 5.40 min). Up to 5% of the microbes survived following ozonisation of conventional ambulances. Of the 126 surface samples collected from ambulances transporting patients with COVID-19, 7 were positive (5.6%) for SARS-related coronavirus as determined on reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). Ozone exposure from the ozone generator prototype inside ambulances at a concentration of 25 ppm for 30 min can eliminate gram positive and negative bacteria, yeasts, and viruses.
Topics: Humans; Disinfection; Ozone; Ambulances; Peru; Pandemics; COVID-19; Staphylococcus aureus; Escherichia coli
PubMed: 37239505
DOI: 10.3390/ijerph20105776 -
Scientific Reports Apr 2023The sterilization characteristics of active species generated by an atmospheric dielectric barrier discharge plasma using air and oxygen at the inner surface of silicone...
The sterilization characteristics of active species generated by an atmospheric dielectric barrier discharge plasma using air and oxygen at the inner surface of silicone tubing were investigated. A dielectric barrier discharge torch plasma device was installed at one end of the tube and generated long-lived active species that flowed into the tube. A strip-type biological indicator with a 10-cell bacterial spore was placed at the opposite end of the 60 cm tube. Sterilization was completed within 30 min by active particles generated from the air plasma. The main factors contributing to the sterilization by air plasma were HNO and NO. When organic materials (keratin, aspartic acid, and dipicolinic acid) reflecting components of the bacterial spore, were treated by the sterilization procedure there was little effect on dipicolinic acid. Keratin was oxidized by ozone and NO generated from the oxygen and air plasmas, respectively. Aspartic acid underwent little change in composition from ozone generated from the oxygen plasma, whereas nitro (NO), nitroso (NO), and aldehyde (CHO) groups were formed from ozone and NO generated from the air plasma.
PubMed: 37117603
DOI: 10.1038/s41598-023-34243-3 -
Medical Gas Research 2023Oral biofilm formation is the main reason for both caries progression and soft tissue diseases. Preventing the formation and promotion of biofilm has been known as the...
Oral biofilm formation is the main reason for both caries progression and soft tissue diseases. Preventing the formation and promotion of biofilm has been known as the first attempt to prevent the development of caries and soft tissue problems in the oral cavity. The present study aimed to assess the effect of ozone and its combined use with chlorhexidine (CHX) and fluoride on the complex biofilm formation of pediatric patients under in situ conditions. Extracted bovine teeth were sterilized and cut into 2 × 3 mm sections. The samples were placed in removable maxillary plates and 10 healthy individuals (6 boys, 4 girls; aged 7-14 years) were asked to wear these plates for 6, 24 and 48 hours. Afterwards, the tooth samples were removed, and anti-plaque agents were applied to the time-related plaque formation. Plaque thickness and viable bacterial percentages were detected by confocal laser scanning microscopy. All materials used in the study decreased the plaque formation and the percentage of viable microorganisms compared with the control group (physiological saline). In 6- and 24-hour biofilm evaluations, ozone-CHX was the most effective group in decreasing the plaque thickness (P > 0.05). Ozone-CHX and Ozone-Fluoride groups were found to be better in 48-hour biofilm assessments in caries-free group (P > 0.05). Ozone-CHX group showed a better inhibitory effect on the viability of microorganisms in 6-, 24- and 48-hour biofilm formations (P < 0.05). Although CHX has been known as the gold standard for inhibiting the oral biofilm formation, according to the results of the study, gaseous ozone and its combined use with CHX have shown better results in reducing the biofilm thickness and viable bacterial percentages of in situ formed time-related biofilm formation in pediatric patients. The use of gaseous ozone can be preferred in clinical conditions in pediatric patients instead of the CHX agents.
Topics: Male; Female; Humans; Animals; Cattle; Child; Chlorhexidine; Anti-Infective Agents, Local; Fluorides; Ozone; Biofilms
PubMed: 37077117
DOI: 10.4103/2045-9912.372820 -
Environmental Science & Technology May 2023Chlorine-based disinfection for drinking water treatment (DWT) was one of the 20th century's great public health achievements, as it substantially reduced the risk of... (Review)
Review
Chlorine-based disinfection for drinking water treatment (DWT) was one of the 20th century's great public health achievements, as it substantially reduced the risk of acute microbial waterborne disease. However, today's chlorinated drinking water is not unambiguously safe; trace levels of regulated and unregulated disinfection byproducts (DBPs), and other known, unknown, and emerging contaminants (KUECs), present chronic risks that make them essential removal targets. Because conventional chemical-based DWT processes do little to remove DBPs or KUECs, alternative approaches are needed to minimize risks by removing DBP precursors and KUECs that are ubiquitous in water supplies. We present the "Minus Approach" as a toolbox of practices and technologies to mitigate KUECs and DBPs without compromising microbiological safety. The Minus Approach reduces problem-causing chemical addition treatment (i.e., the conventional "Plus Approach") by producing biologically stable water containing pathogens at levels having negligible human health risk and substantially lower concentrations of KUECs and DBPs. Aside from ozonation, the Minus Approach avoids primary chemical-based coagulants, disinfectants, and advanced oxidation processes. The Minus Approach focuses on bank filtration, biofiltration, adsorption, and membranes to biologically and physically remove DBP precursors, KUECs, and pathogens; consequently, water purveyors can use ultraviolet light at key locations in conjunction with smaller dosages of secondary chemical disinfectants to minimize microbial regrowth in distribution systems. We describe how the Minus Approach contrasts with the conventional Plus Approach, integrates with artificial intelligence, and can ultimately improve the sustainability performance of water treatment. Finally, we consider barriers to adoption of the Minus Approach.
Topics: Humans; Drinking Water; Artificial Intelligence; Water Pollutants, Chemical; Water Purification; Disinfectants; Disinfection; Halogenation
PubMed: 37074125
DOI: 10.1021/acs.est.2c09389 -
Industrial & Engineering Chemistry... Mar 2023The control of infectious diseases can be improved via carefully designed decontamination equipment and systems. Research interest in ozone (a powerful antimicrobial... (Review)
Review
The control of infectious diseases can be improved via carefully designed decontamination equipment and systems. Research interest in ozone (a powerful antimicrobial agent) has significantly increased over the past decade. The COVID-19 pandemic has also instigated the development of new ozone-based technologies for the decontamination of personal protective equipment, surfaces, materials, and indoor environments. As this interest continues to grow, it is necessary to consider key factors affecting the applicability of lab-based findings to large-scale systems utilizing ozone. In this review, we present recent developments on the critical factors affecting the successful deployments of industrial ozone technologies. Some of these include the medium of application (air or water), material compatibility, efficient circulation and extraction, measurement and control, automation, scalability, and process economics. We also provide a comparative assessment of ozone relative to other decontamination methods/sterilization technologies and further substantiate the necessity for increased developments in gaseous and aqueous ozonation. Modeling methodologies, which can be applied for the design and implementation of ozone contacting systems, are also presented in this review. Key knowledge gaps and open research problems/opportunities are extensively covered including our recommendations for the development of novel solutions with industrial importance.
PubMed: 36943762
DOI: 10.1021/acs.iecr.2c03754 -
The Science of the Total Environment Jun 2023The widespread COVID-19 pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) necessitated measures aimed at preventing the spread of...
The widespread COVID-19 pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) necessitated measures aimed at preventing the spread of SARS-CoV-2. To mitigate the risk of fomite-mediated transmission, environmental cleaning and disinfection regimes have been widely implemented. However, conventional cleaning approaches such as surface wipe downs can be laborious and more efficient and effective disinfecting technologies are needed. Gaseous ozone disinfection is one technology which has been shown to be effective in laboratory studies. Here, we evaluated its efficacy and feasibility in a public bus setting, using murine hepatitis virus (a related betacoronavirus surrogate) and the bacteria Staphylococcus aureus as test organisms. An optimal gaseous ozone regime resulted in a 3.65-log reduction of murine hepatitis virus and a 4.73-log reduction of S. aureus, and decontamination efficacy correlated with exposure duration and relative humidity in the application space. These findings demonstrated gaseous ozone disinfection in field settings which can be suitably translated to public and private fleets that share analogous characteristics.
Topics: Mice; Animals; Humans; COVID-19; Ozone; SARS-CoV-2; Decontamination; Staphylococcus aureus; Pandemics; Anti-Infective Agents; Disinfection
PubMed: 36907397
DOI: 10.1016/j.scitotenv.2023.162704 -
Journal of Maxillofacial and Oral... Dec 2022A comparative study of pain and healing in post-dental extraction sockets treated with ozonated water/oil and normal saline.
AIM
A comparative study of pain and healing in post-dental extraction sockets treated with ozonated water/oil and normal saline.
PURPOSE
The present study was conducted to evaluate the efficacy of ozonated water/oil in reducing pain and enhancing healing and swelling following dental extractions and surgical removal of impacted mandibular third molars.
PATIENTS AND METHODS
Clinical trial was conducted involving 50 individuals requiring two-stage bilateral removal of tooth of which 25 patients were for asymptomatic bilateral extractions and 25 patients for surgical removal of asymptomatic bilaterally similar impacted mandibular third molars. The patients were divided into two groups following a split-mouth design: In group I, sterile ozonated water was irrigated in the sockets after extraction for 2 min on study side and normal saline on the control side following extraction. In group II, transalveolar extractions/surgical extraction of impacted mandibular III molars were carried out under copious irrigation with sterile ozonated water on study side and normal saline irrigation on control side evaluated by independent observer on 2nd, 4th and 7th day for the efficacy of ozonated water/oil in reducing pain and enhancing healing in post-dental extraction sockets.
RESULTS
The use of ozonated water/oil increased the healing rate in all extraction cases, except in 4% of cases in which they did not show any effect of healing in extraction sockets on 7th postoperative day. The use of ozonated water/oil did not show any effects on the healing rate in impaction cases in all postoperative days. The use of ozonated water/oil showed decreased incidence of pain in subjects of both extraction and impaction cases.
PubMed: 36896071
DOI: 10.1007/s12663-020-01486-w -
Frontiers in Veterinary Science 2023Bacterial endometritis is one of the major problems in equine reproduction and usually treated with antimicrobial drugs. The study aimed to compare the effects of...
Bacterial endometritis is one of the major problems in equine reproduction and usually treated with antimicrobial drugs. The study aimed to compare the effects of intrauterine ozone application and systemic antibiotic treatment (trimethoprim-sulfadimethoxine) on intrauterine bacterial growth and possible side effects on the endometrium in a clinical setting. Mares ( = 30) with signs of endometritis (positive uterine bacterial culture and cytological findings) were assigned randomly to different treatments: intrauterine insufflation of an ozone-air-mix (240 ml, 80 μg ozone/ml) twice at a 48 h-interval (Ozone; = 10), systemic antibiotic therapy with trimethoprim-sulfadimethoxine (30 mg/kg, p.o., twice daily) for 5 days (TMS; = 10), or intrauterine insufflation of air (240 ml, sterile-filtered) twice at a 48 h-interval (air; = 10). Endometrial biopsy for histological examination was obtained before the treatment. Histological examination revealed no differences among groups. A control examination, including transrectal ultrasound, bacterial culture, cytological evaluation, and biopsy, was performed 7 days after the last treatment. Overall bacterial growth was reduced in every group after the treatment ( < 0.05), irrespective of the therapy [Ozone: 4/9 (positive culture after treatment/number of mares), TMS: 3/10 and Air: 6/10; > 0.05]. However, Ozone and TMS ( < 0.05) were more effective in reducing growth of gram-negative bacteria as compared to Air ( > 0.05). No effects on the number of polymorphonuclear granulocytes (cytology) were observed ( > 0.05). In conclusion, trimethoprim-sulfadimethoxine and intrauterine ozone insufflation are safe treatment options for bacterial endometritis in mares but the efficacy of both treatments in reducing bacterial growth did not result in a complete absence of intrauterine bacterial growth.
PubMed: 36777673
DOI: 10.3389/fvets.2023.1102149 -
International Journal of Pharmaceutics Mar 2023Hydrogels are extensively used in the biomedical field, as drug delivery systems, wound dressings, contact lenses or as scaffolds for tissue engineering. Due to their... (Review)
Review
Hydrogels are extensively used in the biomedical field, as drug delivery systems, wound dressings, contact lenses or as scaffolds for tissue engineering. Due to their polymeric nature and the presence of high amounts of water in their structure, hydrogels generally present high sensitivity to terminal sterilization. The establishment of an efficient sterilization protocol that does not compromise the functional properties of the hydrogels is one of the challenges faced by researchers when developing a hydrogel for a specific application. Yet, until very recently this aspect was largely ignored in the literature. The present paper reviews the state of literature concerning hydrogels sterilization, compiling the main findings. Conventional terminal sterilization methods (heat sterilization, radiation sterilization, and gas sterilization) as well as emerging sterilization techniques (ozone, supercritical carbon dioxide) are covered. Considerations about aseptic processing are also included. Additionally, and as a framework, hydrogels' polymeric materials, types of networks, and main biomedical applications are summarily described.
Topics: Hydrogels; Sterilization; Contact Lenses; Polymers; Water; Tissue Engineering
PubMed: 36736965
DOI: 10.1016/j.ijpharm.2023.122671 -
Scientific Reports Feb 2023This paper presents a proof-of-concept study establishing effectiveness of the Active Plasma Sterilizer (APS) for decontamination in planetary protection. The APS uses...
This paper presents a proof-of-concept study establishing effectiveness of the Active Plasma Sterilizer (APS) for decontamination in planetary protection. The APS uses Compact Portable Plasma Reactors (CPPRs) to produce surface dielectric barrier discharge, a type of cold plasma, using ambient air to generate and distribute reactive species like ozone used for decontamination. Decontamination tests were performed with pathogenic bacteria (Escherichia coli and Bacillus subtilis) on materials (Aluminum, Polycarbonate, Kevlar and Orthofabric) relevant to space missions. Results show that the APS can achieve 4 to 5 log reductions of pathogenic bacteria on four selected materials, simultaneously at 11 points within 30 min, using power of 13.2 ± 2.22 W. Spatial decontamination data shows the APS can uniformly sterilize several areas of a contaminated surface within 30 min. Ozone penetration through Kevlar and Orthofabric layers was achieved using the CPPR with no external agent assisting penetration. Preliminary material compatibility tests with SEM analysis of the APS exposed materials showed no significant material damage. Thus, this study shows the potential of the APS as a light-weight sustainable decontamination technology for planetary protection with advantages of uniform spatial decontamination, low processing temperatures, low exposure times, material compatibility and the ability to disinfect porous surfaces.
Topics: Decontamination; Bacillus subtilis; Sterilization; Plasma Gases; Escherichia coli; Ozone
PubMed: 36732555
DOI: 10.1038/s41598-023-29049-2