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Journal of Food Protection Apr 2022Our previous survey revealed the poor microbial quality of leafy green vegetables and the presence of Salmonella on these vegetables grown and sold in Accra, Ghana. This...
ABSTRACT
Our previous survey revealed the poor microbial quality of leafy green vegetables and the presence of Salmonella on these vegetables grown and sold in Accra, Ghana. This study validated the efficacy of some cleaning and sanitation methods (tap water, salt solution, lemon juice, and vinegar) commonly used by Ghanaian households, by comparing them with the performance of several sanitation approaches used by the U.S. fresh produce industry (chlorine, peracetic acid, and ozonated water) in reducing Salmonella populations on leafy green vegetables. Cabbage and lettuce leaves inoculated with each of three Salmonella cocktails were treated with sterile water and the previously mentioned six sanitizers. The efficacies of the treatments were evaluated by using the standard plate count assay. The effect of the treatments on the sensory quality of treated vegetables was evaluated by a 97-member consumer panel in the United States. Treatments with citric and acetic acid were as effective as chlorine and peracetic acid in reducing Salmonella counts on vegetable leaves. Ozonated water was less effective than the two organic acids but equally as effective as treatment with the salt solution. Rinsing vegetables with water did not significantly reduce Salmonella counts (P > 0.05). Cabbage leaves treated with citric acid, vinegar, and water were more preferred (P ≤ 0.05) by the consumer panel, while chlorine-treated cabbage leaves were the least preferred. Lettuce samples treated with citric acid and water were more preferred, and salt-treated samples were least preferred. Among the vegetable sanitation methods used by Ghanaian households, treatments with citric and acetic acid are effective in inactivating Salmonella without adversely affecting the sensory quality of treated vegetables.
Topics: Colony Count, Microbial; Disinfectants; Food Microbiology; Ghana; Lactuca; Plant Leaves; Salmonella enterica; Sanitation; Vegetables
PubMed: 35051280
DOI: 10.4315/JFP-21-365 -
Environmental Science and Pollution... May 2022Organisms are increasingly exposed to ultraviolet (UV) rays of sunlight, due to the thinning of the ozone layer and its widespread use in sterilization processes,...
Organisms are increasingly exposed to ultraviolet (UV) rays of sunlight, due to the thinning of the ozone layer and its widespread use in sterilization processes, especially against the SARS-CoV-2 virus. The present study was conducted with the purpose of evaluating the damages of UV-A and UV-C radiations in Allium cepa L. roots. The effects of two different types of UV on some physiological, biochemical, cytogenotoxic, and anatomical parameters were investigated in a multifaceted study. Three groups were formed from Allium bulbs, one of which was the control group. One of the other groups was exposed to 254 nm (UV-C) and the other to 365 nm (UV-A) UV. Growth retardation effect of UV was investigated with respect to germination percentage, total weight gain, and root elongation, while cytogenotoxicity arisen from UV exposure was analyzed using mitotic index (MI) and chromosomal aberration (CA) and micronucleus (MN) frequency. Oxidative stress due to UV application was investigated based on the accumulation of malondialdehyde (MDA) and the total activities of superoxide dismutase (SOD) and catalase (CAT) enzymes. Also, anatomical changes induced by UV-A and UV-C were analyzed in root meristematic cells. UV treatments caused significant reductions in growth-related parameters. Both UV treatments caused a significant increase in MDA levels and induction of SOD and CAT enzymes in root meristematic cells. A decrease in MI and an increase in the frequency of MN and CAs were observed in root tip cells, indicating the cytogenotoxic effect of UV application. Anatomical damages such as epidermis cell damage, cortex cell damage, necrotic zones, giant cell nucleus, and indistinct transmission tissue occurred in cells exposed to UV. All of the physiological, biochemical, cytogenetic, and anatomical damages observed in this study were more severe in cells treated with UV-C compared to UV-A. This study suggested that UV exposure triggered growth inhibition, cytogenotoxicity, oxidative stress, and meristematic cell damages in A. cepa roots depending on the wavelength.
Topics: Allium; COVID-19; DNA Damage; Onions; Plant Roots; SARS-CoV-2; Superoxide Dismutase
PubMed: 35032264
DOI: 10.1007/s11356-021-18147-1 -
International Journal of Environmental... Dec 2021The contamination of ambulances with pathogenic agents represents a potential threat for the public health, not only for common pathogens but also for severe acute...
BACKGROUND
The contamination of ambulances with pathogenic agents represents a potential threat for the public health, not only for common pathogens but also for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The aim of this project was to exploits the germicidal effect of the UVC radiation at 254 nm to sanitize the patient's compartment of ambulances with an advanced UltraViolet SANitizing System (UV-SAN) and assess its relevance for avoiding the spread of COVID-19 and other drug resistant pathogens.
METHODS
The system is equipped with UVC lamps that are activated when the ambulance compartment is empty and sanitize the environment in less than 15 min. An Ozone sensor continuously monitors the gas concentration, ensuring it does not exceed threshold value harmful for patients and operators' health. The system is relying on GNSS data and a satellite communication link, which allow to monitor and record traceability (when, where and what) of all the sanitation operations performed. This information is real-time monitored from a dedicated web-application.
RESULTS
UVC irradiation efficiently reduced SARS-CoV-2 virus titer (>99.99%), on inanimate surfaces such as plastic, stainless steel or rubber, with doses ranging from 5.5 to 24.8 mJ/cm and the UV-SAN system is effective against multi drug resistant (MDR) bacteria up to >99.99%, after 10 to 30 min of irradiation.
CONCLUSIONS
UV-SAN can provide rapid, efficient and sustainable sanitization procedures of ambulances.
Topics: Ambulances; COVID-19; Disinfection; Humans; SARS-CoV-2; Ultraviolet Rays
PubMed: 35010590
DOI: 10.3390/ijerph19010331 -
Scientific Reports Dec 2021The performance of ozonation for the removal of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) using Escherichia coli and Pseudomonas...
The performance of ozonation for the removal of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) using Escherichia coli and Pseudomonas aeruginosa carrying ARGs from hospital wastewaters was evaluated in this study. Bacterial inactivation was determined using plate count methods and real time PCR for ARG damage (Sul1, bla, bla, bla and qnrS). The reduction rate of bacterial cells and ARGs was increased by different amounts of transferred ozone dose from 11 to 45 mg/L. The concentration of 10 cfu/ml bacteria was reduced to an acceptable level by ozone treatment after a 5 min contact time, Although the removal rate was much higher for concentrations of 10 cfu/ml and 10 cfu/ml bacteria. Overall, the tendency of gene reduction by ozonation from more to less was 16S rRNA > sul1 > bla > bla > qnrS > bla. Given that plasmid-borne ARGs can potentially be transferred to other bacteria even after the disinfection process, our results can provide important insights into the fate of ARGs during hospital wastewater ozonation.
Topics: Anti-Bacterial Agents; Disinfection; Drug Resistance, Bacterial; Escherichia coli; Genes, Bacterial; Hospitals; Iran; Ozone; Polymerase Chain Reaction; Pseudomonas aeruginosa; RNA, Ribosomal, 16S; Wastewater; Water Purification
PubMed: 34972828
DOI: 10.1038/s41598-021-04254-z -
Waste Management (New York, N.Y.) Feb 2022The Covid-19 pandemic has certainly changed behaviour patterns in many aspects of life, such as the management of solid wastes inside residential spaces. The goal of...
The Covid-19 pandemic has certainly changed behaviour patterns in many aspects of life, such as the management of solid wastes inside residential spaces. The goal of this research work is to study an ozone generator device as a disinfection and sterilization tool for these wastes in dwellings themselves, thus re-establishing the selective collection to take them back to the recycling chain. In addition, an approach to the risk verification is made. The methodology is based on an experimentation with a device designed to be as cheap as possible. A room like a bedroom is used as a test bed to apply the device, but with no people inside the room to avoid risks. The results show that the device is feasible, concluding that risks are acceptable if its use is correct and appropriate equipment is available to be applied and controlled, all without prejudice of the rigorous control by the competent authorities that approve its use.
Topics: COVID-19; Disinfection; Humans; Ozone; Pandemics; SARS-CoV-2
PubMed: 34942557
DOI: 10.1016/j.wasman.2021.11.041 -
Poultry Science Feb 2022Methods to control microbial contamination in confined livestock facilities are important to the health of both animals and workers. In addition, bacterial contamination...
Methods to control microbial contamination in confined livestock facilities are important to the health of both animals and workers. In addition, bacterial contamination is also a food safety issue. The most common disinfection technique employed in livestock facilities is the application of oxidizing agents (e.g., potassium peroxymonosulphate, chlorine, hydrogen peroxide, ozone). However, these techniques are associated with a number of limitations (e.g., toxicity, high cost, corrosiveness). Recently, engineered water nanostructures (EWNS) generated using an electrospray system was found effective in inactivating foodborne bacteria. Thus, this study investigated the efficacy of EWNS generated using a laboratory-scale electrospray system in inactivating bacteria found in poultry facilities. The effects of various operating conditions (distance between the injector and grounded electrode of the electrospray system, applied voltage, liquid pH and conductivity, liquid flow rate, and treatment time) on the efficacy were also assessed. In these various experiments, airborne bacterial samples were collected from a pullet room using tryptic soy agar plates and then exposed to EWNS under varying conditions. After treatment, the plates were incubated at 37°C prior to colony counting. Reductions in bacterial concentrations up to 1.26 logs were obtained. The results indicate that the EWNS generated by the electrospray system can be a potential chemical-free alternative to conventional disinfection methods. Future tests will focus on scaling up the system for larger scale trials.
Topics: Animals; Bacteria; Chickens; Disinfectants; Disinfection; Female; Nanostructures; Poultry; Water
PubMed: 34922044
DOI: 10.1016/j.psj.2021.101580 -
Cureus Sep 2021Personal protective equipment (PPE) is urgently sought during public health crises. It is necessary for the safety of both the patient and the healthcare professional....
OBJECTIVE
Personal protective equipment (PPE) is urgently sought during public health crises. It is necessary for the safety of both the patient and the healthcare professional. Yet during the recent COVID-19 pandemic, PPE scarcity in many countries, including the United States, has impacted the level of care for patients and the safety of healthcare personnel. Additionally, the implementation of mandatory mask mandates for the general public in many countries forced individuals to either reuse PPE, which can contribute to poor hygiene, or buy PPE in bulk and thereby contribute to the scarcity of PPE. In this study, we investigate the possibility of using a cost-effective ozone sterilization unit on contaminated N95 masks as an alternative to current sterilization methods.
METHOD
This protocol examined ozone's ability to decontaminate N95 mask fabric that was exposed to a surrogate virus (). Once the sterilization unit achieves an ozone concentration of ~30 ppm, a 60-minute or 120-minute sterilization cycle commences. Following the sterilization cycle, we investigated the amount of viable virus on the slide using a viral plaque assay and compared it to a non-sterilized, control slide. Furthermore, we carried out trials to investigate the safety of an ozone sterilization device, by measuring the levels of ozone exposure that individuals may experience when operating the sterilization unit post-cycle.
RESULTS
We showed that a 120-minute sterilization cycle at ~30 ppm achieves a 3-log reduction in viral activity, thereby complying with industry and U.S. Food and Drug Administration (FDA) standards. Further, we demonstrated that when following our protocol, the ozone exposure levels for a simple sterilization unit to be used at home complied with federal and industry standards.
CONCLUSION
Ozone may have the potential to decontaminate masks and other PPE.
PubMed: 34722033
DOI: 10.7759/cureus.18228 -
The Journal of Hospital Infection Jan 2022Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease 2019, has caused millions of deaths worldwide. The virus is... (Review)
Review
BACKGROUND
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease 2019, has caused millions of deaths worldwide. The virus is transmitted by inhalation of infectious particles suspended in the air, direct deposition on mucous membranes and indirect contact via contaminated surfaces. Disinfection methods that can halt such transmission are important in this pandemic and in future viral infections.
AIM
To highlight the efficacy of several disinfection methods against SARS-CoV-2 based on up-to-date evidence found in the literature.
METHODS
Two databases were searched to identify studies that assessed disinfection methods used against SARS-CoV-2. In total, 1229 studies were identified and 60 of these were included in this review. Quality assessment was evaluated by the Office of Health Assessment and Translation's risk-of-bias tool.
FINDINGS
Twenty-eight studies investigated disinfection methods on environmental surfaces, 16 studies investigated disinfection methods on biological surfaces, four studies investigated disinfection methods for airborne coronavirus, and 16 studies investigated methods used to recondition personal protective equipment (PPE).
CONCLUSIONS
Several household and hospital disinfection agents and ultraviolet-C (UV-C) irradiation were effective for inactivation of SARS-CoV-2 on environmental surfaces. Formulations containing povidone-iodine can provide virucidal action on the skin and mucous membranes. In the case of hand hygiene, typical soap bars and alcohols can inactivate SARS-CoV-2. Air filtration systems incorporated with materials that possess catalytic properties, UV-C devices and heating systems can reduce airborne viral particles effectively. The decontamination of PPE can be conducted safely by heat and ozone treatment.
Topics: COVID-19; Disinfection; Humans; Pandemics; Povidone-Iodine; SARS-CoV-2
PubMed: 34673114
DOI: 10.1016/j.jhin.2021.07.014 -
Antimicrobial Resistance and Infection... Oct 2021With the current COVID-19 pandemic, many healthcare facilities have been lacking a steady supply of filtering facepiece respirators. To better address this challenge,...
BACKGROUND
With the current COVID-19 pandemic, many healthcare facilities have been lacking a steady supply of filtering facepiece respirators. To better address this challenge, the decontamination and reuse of these respirators is a strategy that has been studied by an increasing number of institutions during the COVID-19 pandemic.
METHODS
We conducted a systematic literature review in PubMed, PubMed Central, Embase, and Google Scholar. Studies were eligible when (electronically or in print) up to 17 June 2020, and published in English, French, German, or Spanish. The primary outcome was reduction of test viruses or test bacteria by log3 for disinfection and log6 for sterilization. Secondary outcome was physical integrity (fit/filtration/degradation) of the respirators after reprocessing. Materials from the grey literature, including an unpublished study were added to the findings.
FINDINGS
Of 938 retrieved studies, 35 studies were included in the analysis with 70 individual tests conducted. 17 methods of decontamination were found, included the use of liquids (detergent, benzalkonium chloride, hypochlorite, or ethanol), gases (hydrogen peroxide, ozone, peracetic acid or ethylene oxide), heat (either moist with or without pressure or dry heat), or ultra violet radiation (UVA and UVGI); either alone or in combination. Ethylene oxide, gaseous hydrogen peroxide (with or without peracetic acid), peracetic acid dry fogging system, microwave-generated moist heat, and steam seem to be the most promising methods on decontamination efficacy, physical integrity and filtration capacity.
INTERPRETATION
A number of methods can be used for N95/FFP2 mask reprocessing in case of shortage, helping to keep healthcare workers and patients safe. However, the selection of disinfection or sterilization methods must take into account local availability and turnover capacity as well as the manufacturer; meaning that some methods work better on specific models from specific manufacturers.
SYSTEMATIC REGISTRATION NUMBER
CRD42020193309.
Topics: COVID-19; Decontamination; Equipment Reuse; Humans; N95 Respirators
PubMed: 34635165
DOI: 10.1186/s13756-021-00993-w -
New Biotechnology Jan 2022The COVID-19 pandemic has generated a major need for non-destructive and environmentally friendly disinfection methods. This work presents the development and testing of...
The COVID-19 pandemic has generated a major need for non-destructive and environmentally friendly disinfection methods. This work presents the development and testing of a disinfection process based on gaseous ozone for SARS-CoV-2-contaminated porous and non-porous surfaces. A newly developed disinfection chamber was used, equipped with a CeraPlas™ cold plasma generator that produces ozone during plasma ignition. A reduction of more than log 6 of infectious virus could be demonstrated for virus-contaminated cotton and FFP3 face masks as well as glass slides after exposure to 800 ppm ozone for 10-60 min, depending on the material. In contrast to other disinfectants, ozone can be produced quickly and cost-effectively, and its environmentally friendly breakdown product oxygen does not leave harmful residues. Disinfection with ozone could help to overcome delivery difficulties of personal protective equipment by enabling safe reuse with further applications, thereby reducing waste generation, and may allow regular disinfection of personal items with non-porous surfaces.
Topics: Disinfection; Equipment Contamination; Masks; Ozone; Porosity; SARS-CoV-2; Virus Inactivation
PubMed: 34626837
DOI: 10.1016/j.nbt.2021.10.001