COVID-19: Critical discussion on the applications and implications of chemicals in sanitizers and disinfectants

Prospect of nanomaterials as antimicrobial and antiviral regimen

In recent years studies of nanomaterials have been explored in the field of microbiology due to the increasing evidence of antibiotic resistance. Nanomaterials could be inorganic or organic, and they may be synthesized from natural products from plant or animal origin. The therapeutic applications of nano-materials are wide, from diagnosis of disease to targeted delivery of drugs. Broad-spectrum antiviral and antimicrobial activities of nanoparticles are also well evident. The ratio of nanoparticles surface area to their volume is high and that allows them to be an advantageous vehicle of drugs in many respects. Effective uses of various materials for the synthesis of nanoparticles impart much specificity in them to meet the requirements of specific therapeutic strategies. The potential therapeutic use of nanoparticles and their mechanisms of action against infections from bacteria, fungi and viruses were the focus of this review. Further, their potential advantages, drawbacks, limitations and side effects are also included here. Researchers are characterizing the exposure pathways of nano-medicines that may cause serious toxicity to the subjects or the environment. Indeed, societal ethical issues in using nano-medicines pose a serious question to scientists beyond anything.

Comprehensive insight into triclosan-from widespread occurrence to health outcomes

Humans are exposed to the variety of emerging environmental pollutant in everyday life. The special concern is paid to endocrine disrupting chemicals especially to triclosan which could interfere with normal hormonal functions. Triclosan could be found in numerous commercial products such as mouthwashes, toothpastes and disinfectants due to its antibacterial and antifungal effects. Considering the excessive use and disposal, wastewaters are recognized as the main source of triclosan in the aquatic environment. As a result of the incomplete removal, triclosan residues reach surface water and even groundwater. Triclosan has potential to accumulate in sediment and aquatic organisms. Therefore, the detectable concentrations of triclosan in various environmental and biological matrices emerged concerns about the potential toxicity. Triclosan impairs thyroid homeostasis and could be associated with neurodevelopment impairment, metabolic disorders, cardiotoxicity and the increased cancer risk. The growing resistance of the vast groups of bacteria, the evidenced toxicity on different aquatic organisms, its adverse health effects observed in vitro, in vivo as well as the available epidemiological studies suggest that further efforts to monitor triclosan toxicity at environmental levels are necessary. The safety precaution measures and full commitment to proper legislation in compliance with the environmental protection are needed in order to obtain triclosan good ecological status. This paper is an overview of the possible negative triclosan effects on human health. Sources of exposure to triclosan, methods and levels of detection in aquatic environment are also discussed.

Understanding of environmental pollution and its anthropogenic impacts on biological resources during the COVID-19 period

The global outbreak of the COVID-19 pandemic has given rise to a significant health emergency to adverse impact on environment, and human society. The COVID-19 post-pandemic not only affects human beings but also creates pollution crisis in environment. The post-pandemic situation has shown a drastic change in nature due to biomedical waste load and other components. The inadequate segregation of untreated healthcare wastes, chemical disinfectants, and single-use plastics leads to contamination of the water, air, and agricultural fields. These materials allow the growth of disease-causing agents and transmission. Particularly, the COVID-19 outbreak has posed a severe environmental and health concern in many developing countries for infectious waste. In 2030, plastic enhances a transboundary menace to natural ecological communities and public health. This review provides a complete overview of the COVID-19 pandemic on environmental pollution and its anthropogenic impacts to public health and natural ecosystem considering short- and long-term scenarios. The review thoroughly assesses the impacts on ecosystem in the terrestrial, marine, and atmospheric realms. The information from this evaluation can be utilized to assess the short-term and long-term solutions for minimizing any unfavorable effects. Especially, this topic focuses on the excessive use of plastics and their products, subsequently with the involvement of the scientific community, and policymakers will develop the proper management plan for the upcoming generation. This article also provides crucial research gap knowledge to boost national disaster preparedness in future perspectives.

The Lesson Learned from the COVID-19 Pandemic: Can an Active Chemical Be Effective, Safe, Harmless-for-Humans and Low-Cost at a Time? Evidence on Aerosolized Hypochlorous Acid

The COVID-19 pandemic has underlined the importance of disinfectants as tools to prevent and fight against coronavirus spreading. An ideal disinfectant and sanitizer must be nontoxic to surface contact, noncorrosive, effective, and relatively inexpensive as it is hypochlorous acid (HOCl). The present work intended to evaluate, on different surfaces, the bactericidal and virucidal effectiveness of nebulized HOCl and test its safety usage in 2D and 3D skin and lung models. Our data showed that HOCl at the dose of 300 ppm did not affect cellular and tissue viability, not their morphology. The HOCl bactericidal properties varies with the surface analyzed: 69% for semi-porous, 96-99.9% for flat and porous. This discrepancy was not noticed for the virucidal properties. Overall, this study showed that nebulized HOCl can prevent virus and bacteria growth without affecting lung and skin tissues, making this compound a perfect candidate to sanitize indoor environments.

Assessment of compliance to packaging and labeling regulatory requirements of locally manufactured alcohol-based hand sanitizers marketed in Addis Ababa, Ethiopia

Background

Following the emergence of the global Coronavirus Disease-2019 (COVID-19) pandemic, alcohol-based hand sanitizers (ABHS) have been extensively used as one of the effective methods of preventing its transmission. The products are dispensed over the counter and used by the general population. Growing concerns have been reported, however, regarding the quality, efficacy and compliance to regulatory requirements calling for objective evidence that can facilitate proactive regulatory measures.

Objectives

The study aimed at assessing the level of compliance to packaging and labeling regulatory requirements of selected locally manufactured ABHS products marketed in Addis Ababa, Ethiopia.

Methods

A cross-sectional study design was employed to randomly collect 25 locally manufactured ABHS products from retail outlets located in Addis Ababa. The manufacturers were grouped under four categories considering their experience in manufacturing, resources and technical capacities. The collected samples were evaluated for compliance to packaging and labeling information regulatory requirements and the results subjected to descriptive analysis.

Results

Majority of the products were found to meet most of the packaging, general product description and manufacturer-related information requirements. However, concerning gaps were observed in storage, precaution and warning-related labeling information requirements. The overall compliance of the selected products (to a total of 29 requirements under 5 categories) was 56.9%. The highest level of compliance was for general product information requirements (80.2%) followed by packaging and manufacturer-related requirements accounting for 76.8% and 75.0%, respectively. Low level of compliance was observed for storage condition and precautions (10.2% and 42.4%, respectively). Better overall compliance to packaging and labeling requirements (62.9%) were observed by large pharmaceutical and cosmetics manufacturers, while the lowest compliance level was recorded for medium level pharmaceuticals and cosmetics manufacturers.

Conclusions

Even though most of the selected products were able to comply with the majority of packaging, product description and manufacturer-related requirements, gaps were observed in essential labeling information requirements. Considering the extensive use of ABHS products among diverse population groups and the potential risks associated with inappropriate use of the products, improving regulatory law enforcement practices, strengthening continuing education of manufacturing personnel and raising public awareness is very timely.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40545-022-00456-6.

Clostridium perfringens Spores in Urology Hospitals

Background: Clostridium spp. spores are resistant to many factors, including alcohol-based disinfectants. The presence of clostridial spores in a hospital environment may lead to infection outbreaks among patients and health care workers. Objective: This study aimed to detect clostridial spores in aurology hospital using C diff Banana Broth™ and assess the antibiotic sensitivity and toxinotypes of isolates. Methods: After diagnosing COVID-19 in medical staff and closing an 86-bed urology hospital in 2020 for H2O2 fogging, 58 swabs from the hospital environment were inoculated to C diff Banana Broth™, incubated at 37°C for 14 days, checked daily, and positive broths were sub-cultured anaerobically for 48 h at 37°C. After identification, multiplex PCR (mPCR) was performed for Clostridium perfringens, C. difficile toxin genes, and MIC determination. Results: In this study, 16.58 (~ 28%) strains of Clostridium spp. were cultured: 11 - C. perfringens, 2 - C. baratii, and 1 each of C. paraputrificum, C. difficile, and C. clostridioforme. Moreover, C. difficile produced all toxins, and 11 C. perfringens consisted of 1 cpa, 7 cpb2, 2 cpiA, and 1 cpb gene-positive. All isolates were sensitive to metronidazole, vancomycin, moxifloxacin, penicillin/tazobactam, and rifampicin. Two out of the 11 C. perfringens strains were resistant to erythromycin and clindamycin. Conclusions: Regardless of the performed H2O2 fogging, antibiotic-resistant, toxigenic strains of C. perfringens (69%) obtained from the urology hospital environment were cultured using C diff Banana Broth™, indicating the need to develop the necessary sanitary and epidemiological procedures in this hospital.

Interaction of Bioactive Compounds of Moringa oleifera Leaves with SARS-CoV-2 Proteins to Combat COVID-19 Pathogenesis: a Phytochemical and In Silico Analysis

Novel SARS-CoV-2 claimed a large number of human lives. The main proteins for viral entry into host cells are SARS-CoV-2 spike glycoprotein (PDB ID: 6VYB) and spike receptor-binding domain bound with ACE2 (spike RBD-ACE2; PDB ID: 6M0J). Currently, specific therapies are lacking globally. This study was designed to investigate the bioactive components from Moringa oleifera leaf (MOL) extract by gas chromatography-mass spectroscopy (GC–MS) and their binding interactions with spike glycoprotein and spike RBD-ACE2 protein through computational analysis. GC–MS-based analysis unveiled the presence of thirty-seven bioactive components in MOL extract, viz. polyphenols, fatty acids, terpenes/triterpenes, phytosterols/steroids, and aliphatic hydrocarbons. These bioactive phytoconstituents showed potential binding with SARS-CoV-2 spike glycoprotein and spike RBD-ACE2 protein through the AutoDock 4.2 tool. Further by using AutoDock 4.2 and AutoDock Vina, the top sixteen hits (binding energy ≥  − 6.0 kcal/mol) were selected, and these might be considered as active biomolecules. Moreover, molecular dynamics simulation was determined by the Desmond module. Interestingly two biomolecules, namely β-tocopherol with spike glycoprotein and β-sitosterol with spike RBD-ACE2, displayed the best interacting complexes and low deviations during 100-ns simulation, implying their strong stability and compactness. Remarkably, both β-tocopherol and β-sitosterol also showed the drug- likeness with no predicted toxicity. In conclusion, these findings suggested that both compounds β-tocopherol and β-sitosterol may be developed as anti-SARS-CoV-2 drugs. The current findings of in silico approach need to be optimized using in vitro and clinical studies to prove the effectiveness of phytomolecules against SARS-CoV-2.

In vitro assessment of skin sensitization, irritability and toxicity of bacteriocins and reuterin for possible topical applications

Bacteriocins and reuterin are promising antimicrobials for application in food, veterinary, and medical sectors. In the light of their high potential for application in hand sanitizer, we investigated the skin toxicity of reuterin, microcin J25, pediocin PA-1, bactofencin A, and nisin Z in vitro using neutral red and LDH release assays on NHEK cells. We determined their skin sensitization potential using the human cell line activation test (h-CLAT). Their skin irritation potential was measured on human epidermal model EpiDerm™. We showed that the viability and membrane integrity of NHEK cells remained unaltered after exposure to bacteriocins and reuterin at concentrations up to 400 µg/mL and 80 mg/mL, respectively. Furthermore, microcin J25 and reuterin showed no skin sensitization at concentrations up to 100 µg/mL and 40 mg/mL, respectively, while pediocin PA-1, bactofencin A, and nisin Z caused sensitization at concentrations higher than 100 µg/mL. Tissue viability was unaffected in presence of bacteriocins and reuterin at concentrations up to 200 µg/mL and 40 mg/mL, respectively, which was confirmed by measuring cytokine IL-1α and IL-8 levels and by histological analysis. In conclusion, the current study provides scientific evidence that some bacteriocins and reuterin, could be safely applied topically as sanitizers at recommended concentrations.

COVID-19 lockdown and natural resources: a global assessment on the challenges, opportunities, and the way forward

BACKGROUND

The Coronavirus (COVID-19) is a global pandemic caused by SARS-CoV-2, which has an enormous effect on human lives and the global environment. This review aimed to assess the global scientific evidence on the impact of COVID-19 lockdown on natural resources using international databases and search engines. Thus, the unprecedented anthropause due to COVID-19 has positive and negative effects on natural resources.

MAIN BODY

This review showed that the unprecedented pandemic lockdown events brought a negative impact on the physical environment, including pollution associated with a drastic increase in person protective equipment, deforestation, illegal poaching and logging, overfishing, disruption of the conservation program and projects. It is noted that the spread of pandemic diseases could be aggravated by environmental pollution and a rapid increase in the global population. Despite these negative impacts of COVID-19, the anthropause appear to have also several positive effects on natural resources such as short term reduction of indoor and outdoor environmental pollutants (PM2.5, PM10, NO2, SO2, CO, and CO2), reduction in noise pollutions from ships, boats, vehicles, and planes which have positive effects on aquatic ecosystems, water quality, birds behaviour, wildlife biodiversity, and ecosystem restoration.

CONCLUSION

Therefore, governments and scientific communities across the globe have called for a green recovery to COVID-19 and implement multi-actor interventions and environmentally friendly technologies to improve and safeguard sustainable environmental and biodiversity management and halt the next pandemic.

Impact of the COVID-19 pandemic on household disinfectant consumption behaviors and related environmental concerns: A questionnaire-based survey in China

Considering the potential hazardous effects of disinfectant residues on environment, organisms and biodiversity, the sharp rise in use of disinfectants during COVID-19 pandemic has been considered highly likely to cause worldwide secondary disasters in ecosystems and human health. This questionnaire-based survey investigated the impact of COVID-19 outbreak on household disinfectant product consumption levels and behavior of 3667 Chinese residents. In particular, in the context that no strategy is currently available to minimize the disinfectant pollution, based on the similarities between disinfectants and pharmaceuticals, we proposed a perspective of ecopharmacovigilance (EPV), which is an effective measure to minimize the environmental risks posed by pharmaceuticals using drug administration protocols, for disinfectant environmental risk management. The public's environmental perceptions, attitudes and the related practices regarding household disinfectant consumption from an EPV perspective were also included in the study. The results showed that the COVID-19 outbreak caused a tremendous rise in the public's household disinfectant consumption and usage levels in China. After the COVID-19 outbreak, the chlorine-based and alcohol-based disinfectants were considered as the most preferred products for household disinfection and hand sanitization, respectively. Importantly, the Chinese public's environmental perceptions and practice on disinfectants were poor. Less than half respondents had positive attitudes toward the source control of disinfectant pollution. The population groups including females, the middle aged adults, those having healthcare professional background, as well as the higher-educated could be focused on to develop targeted efforts for the future control of disinfectant pollution in environment.

Experimental analysis of solar powered disinfection tunnel mist spray system for coronavirus prevention in public and remote places

There is a pressing need to accelerate the development of advanced technologies to prevent Coronavirus in large gatherings. The present system is an integration of tunnel disinfectant spray system and solar setup which utilises the solar energy to power a pump which pushes the required amount of chemical mixture into the nozzles of the spray system in order to eliminate any incoming virus or bacteria on the clothes of a particular person without wetting it. Data was gathered for a mall in New Delhi related to occupancy levels before and after lockdown. A 47% and 35% spike in energy and disinfectant mixture to pump was evaluated on weekends. A 70% reduction in operating cost was registered for solar based system in comparison to non-solar setup. Optimum conditions by considering efficiency and cost effectiveness evaluated are 8 number of nozzles, nozzle angle 55 degrees spray pressure 200 bar, and pressure 200 bar.

COVID-19: Eco-friendly hand hygiene for human and environmental safety

The Coronavirus disease-2019 (COVID-19) outbreak is caused by a highly pathogenic novel coronavirus (SARS-CoV-2). To date, there is no prescribed medicine for COVID-19. Frequent handwashing with soap and the use of alcohol-based hand sanitizers is recommended by WHO for hand hygiene and to prevent the spread of COVID-19. However, there are safety concerns associated with the use of soaps and alcohol-based hand sanitizers. Therefore, the review aims to highlight the health and environmental concerns associated with the frequent use of soaps/detergents and alcohol-based hand sanitizers amid COVID-19. The potential of some of the natural detergents and sanitizing agents as eco-friendly alternatives to petrochemical-based soaps and alcohol-based hand rubs for hand hygiene are discussed. The market of soaps and hand sanitizers is expected to grow in the coming years and therefore, future research should be directed to develop eco-friendly soaps and hand sanitizers for human and environmental safety.

Alcohol-Based Hand Sanitizers in COVID-19 Prevention: A Multidimensional Perspective

The global use of alcohol-based hand sanitizers (ABHS) as an important means of controlling the transmission of infectious disease has increased significantly as governments and public health agencies across the world advocated hand hygiene as a preventative measure during the COVID-19 pandemic. Although the performance of these products is most commonly defined as a function of their alcohol concentration, they are multifaceted products in which an interplay of several factors is important in determining efficacy. This paper discusses the interplay between ABHS input (formulation) factors and output (product performance) factors in the context of a multidimensional perspective using a novel representative paradigm. In the model, represented in the form of a three-dimensional tetrahedron, each of the faces represents inputs in the manufacturing of the ABHS product, which are the type and amount of alcohol, the inactive ingredients, the formulation and the manufacturing practices. The four corners of the tetrahedron represent the product performance factors which include product efficacy, sensory characteristics, usage and compliance and product safety. The multidimensional approach to the formulation and evaluation of ABHS shows that several factors contribute to the effectiveness and utility of these products. The paradigm provides a useful framework for manufacturers of ABHS and related healthcare products.

New threatening of SARS-CoV-2 coinfection and strategies to fight the current pandemic

Coronavirus disease (COVID-19) is a global pandemic. The COVID-19 outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has overloaded healthcare systems that need medication to be rapidly established, at least to minimize the incidence of COVID-19. The coinfection with other microorganisms has drastically affected human health. Due to the utmost necessity to treat the patient infected with COVID-19 earliest, poor diagnosis and misuse of antibiotics may lead the world where no more drugs are available even to treat mild infections. Besides, sanitizers and disinfectants used to help minimize widespread coronavirus infection risk also contribute to an increased risk of antimicrobial resistance. To ease the situation, zinc supplements' potentiality has been explored and found to be an effective element to boost the immune system. Zinc also prevents the entry of the virus by increasing the ciliary beat frequency. Furthermore, the limitations of current antiviral agents such as a narrow range and low bioavailability can be resolved using nanomaterials, which are considered an important therapeutic alternative for the next generation. Thus, the development of new antiviral nanoagents will significantly help tackle many potential challenges and knowledge gaps. This review paper provides profound insight into how COVID-19 and antimicrobial resistance (AMR) are interrelated and the possible implications and current strategies to fight the ongoing pandemic.

Implications of COVID-19 Pandemic on the Emergence of Antimicrobial Resistance: Adjusting the Response to Future Outbreaks

The net effect of the coronavirus disease 2019 (COVID-19) pandemic and the response to it on the emergence of antimicrobial resistance is yet unknown. Positive impacts on the spread of multiresistant pathogens and infections in general may be observed with the implementation of general preventative measures for the spread of infectious disease such as social distancing, reduced travel and increased personal hygiene. This pandemic has accelerated the development of novel technologies, such as mRNA vaccines, that may be used to fight other diseases. These should be capitalized upon to manage the ongoing antimicrobial resistance pandemic in the background. However, it is likely that the COVID-19 pandemic is fueling the emergence of antimicrobial resistance due to high rates of inappropriate antimicrobial prescribing, the high use of biocides and the interruption of treatment for other conditions. Clinical uncertainty driven by the lack of effective diagnostics and practice of telemedicine may have driven the inappropriate use of antimicrobials. As pathogens know no borders, increased focus is needed for infectious diseases still threatening low- and middle-income countries such as tuberculosis. Stewardship measures for future outbreaks should stress the importance of social distancing and hand washing but discourage the overuse of disinfectants and antimicrobials that are not proven effective.

Nanoparticles as antimicrobial and antiviral agents: A literature-based perspective study

The scientific explorations of nanoparticles for their inherent therapeutic potencies as antimicrobial and antiviral agents due to increasing incidences of antibiotic resistance have gained more attention in recent time. This factor amongst others necessitates the search for newer and more effective antimicrobial agents. Several investigations have demonstrated the prospects of nanoparticles in the treatment of various microbial infections. The therapeutic applications of nanoparticles as either delivery agent or broad spectrum inhibition agents in viral and microbial investigations can no longer be overlooked. Their large surface area to volume ratio made them an indispensable substance as delivery agents in many respect. Various materials have been used for the synthesis of nanoparticles with unique properties channelised to meet specific therapeutic requirement. This review focuses on the antibacterial, antifungal, and antiviral potential of nanoparticles with their probable mechanism of action.

Environment and COVID-19: Pollutants, impacts, dissemination, management and recommendations for facing future epidemic threats

Coronavirus disease 2019 (COVID-19) has become a global pandemic. Its relationship with environmental factors is an issue that has attracted the attention of scientists and governments. This article aims to deal with a possible association between COVID-19 and environmental factors and provide some recommendations for adequately controlling future epidemic threats. Environmental management through ecosystem services has a relevant role in exposing and spreading infectious diseases, reduction of pollutants, and control of climatic factors. Pollutants and viruses (such as COVID-19) produce negative immunological responses and share similar mechanisms of action. Therefore, they can have an additive and enhancing role in viral diseases. Significant associations between air pollution and COVID-19 have been reported. Particulate matter (PM2.5, PM10) can obstruct the airway, exacerbating cases of COVID-19. Some climatic factors have been shown to affect SARS-CoV-2 transmission. Yet, it is not well established if climatic factors might have a cause-effect relationship to the spreading of SARS-CoV-2. So far, positive as well as negative indirect environmental impacts have been reported, with negative impacts greater and more persistent. Too little is known about the current pandemic to evaluate whether there is an association between environment and positive COVID-19 cases. We recommend smart technology to collect data remotely, the implementation of "one health" approach between public health physicians and veterinarians, and the use of biodegradable medical supplies in future epidemic threats.

Potential of Cell-Free Supernatant from Lactobacillus plantarum NIBR97, Including Novel Bacteriocins, as a Natural Alternative to Chemical Disinfectants

The recent pandemic of coronavirus disease 2019 (COVID-19) has increased demand for chemical disinfectants, which can be potentially hazardous to users. Here, we suggest that the cell-free supernatant from Lactobacillus plantarum NIBR97, including novel bacteriocins, has potential as a natural alternative to chemical disinfectants. It exhibits significant antibacterial activities against a broad range of pathogens, and was observed by scanning electron microscopy (SEM) to cause cellular lysis through pore formation in bacterial membranes, implying that its antibacterial activity may be mediated by peptides or proteins and supported by proteinase K treatment. It also showed significant antiviral activities against HIV-based lentivirus and influenza A/H3N2, causing lentiviral lysis through envelope collapse. Furthermore, whole-genome sequencing revealed that NIBR97 has diverse antimicrobial peptides, and among them are five novel bacteriocins, designated as plantaricin 1 to 5. Plantaricin 3 and 5 in particular showed both antibacterial and antiviral activities. SEM revealed that plantaricin 3 causes direct damage to both bacterial membranes and viral envelopes, while plantaricin 5 damaged only bacterial membranes, implying different antiviral mechanisms. Our data suggest that the cell-free supernatant from L. plantarum NIBR97, including novel bacteriocins, is potentially useful as a natural alternative to chemical disinfectants.