Destruction mechanisms of ozone over SARS-CoV-2

In this pandemic SARS-CoV-2 crisis, any attempt to contain and eliminate the virus will also stop its spread and consequently decrease the risk of severe illness and death. While ozone treatment has been suggested as an effective disinfection process, no precise mechanism of action has been previously reported. This study aimed to further investigate the effect of ozone treatment on SARS-CoV-2. Therefore, virus collected from nasopharyngeal and oropharyngeal swab and sputum samples from symptomatic patients was exposed to ozone for different exposure times. The virus morphology and structure were monitored and analyzed through Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Atomic Absorption Spectroscopy (AAS), and ATR-FTIR. The obtained results showed that ozone treatment not only unsettles the virus morphology but also alters the virus proteins’ structure and conformation through amino acid disturbance and Zn ion release from the virus non-structural proteins. These results could provide a clearer pathway for virus elimination and therapeutics preparation.

Atomic force microscopy analysis of native infectious and inactivated SARS-CoV-2 virions

SARS-CoV-2 is an enveloped virus responsible for the Coronavirus Disease 2019 (COVID-19) pandemic. Here, single viruses were analyzed by atomic force microscopy (AFM) operating directly in a level 3 biosafety (BSL3) facility, which appeared as a fast and powerful method to assess at the nanoscale level and in 3D infectious virus morphology in its native conformation, or upon inactivation treatments. AFM imaging reveals structurally intact infectious and inactivated SARS-CoV-2 upon low concentration of formaldehyde treatment. This protocol combining AFM and plaque assays allows the preparation of intact inactivated SARS-CoV-2 particles for safe use of samples out of level 3 laboratory to accelerate researches against the COVID-19 pandemic. Overall, we illustrate how adapted BSL3-AFM is a remarkable toolbox for rapid and direct virus analysis based on nanoscale morphology.

CHALLENGES OF TIO2-COMPOSITE, AS A VISIBLE ACTIVE PHOTOCATALYST MATERIAL FOR SARS-COV-2 ANTIVIRAL COMPARED WITH THE OTHER VIRUSES

The efforts in dealing with COVID-19 in various aspects are continuously being carried out, such as the photocatalytic process. Interestingly, TiO2 plays an important role as an environmentally friendly photocatalyst with a visible and UV absorption range. The increase in the antiviral performance of this compound is further maximized by formulating TiO2-based composites and doping it to reduce the bandgap. This review aims to determine the challenges of TiO2-based composite as a visible active photocatalyst material for SARS-CoV-2 antiviral. It presents a discussion of the photocatalytic function of TiO2, by comparing the secondary data obtained from viruses that have been successfully degraded by the SARS-CoV-2. The literature search led to the analysis of the photocatalyst quality, structure, composition, and the degraded viruses. This comparison was based on the photocatalyst’s general constituents, such as protein and RNA. The virus morphology as observed in the secondary data was successfully destroyed by hydroxyl radicals resulting from the photocatalytic processes. It was observed that TiO2 photocatalyst generated ROS, capable of inactivating various viruses, therefore, it has the potential in fighting against the SARS-CoV-2. Moreover, further research is needed in photocatalyst design, its role, and the overall mechanism of virus inactivation.

Direct visualization of native infectious SARS-CoV-2 and its inactivation forms using high resolution Atomic Force Microscopy

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for COVID19, a new emerging pandemic affecting humans. Here, single viruses were analyze by atomic force microscopy (AFM) operating directly in a level 3 biosafety (BSL3) facility, which appeared as a fast and powerful method to assess infectious virus morphology in its native conformation, or upon inactivation treatments, at the nanoscale level and in 3D. High resolution AFM reveals structurally intact infectious and inactivated SARS-CoV-2 upon low concentration of formaldehyde treatment. This protocol allows the preparation of intact inactivated SARS-CoV-2 particles for safe use of samples out of level 3 laboratory, as revealed by combining AFM and plaque assays, to accelerate researches against the COVID-19 pandemic. Overall, we illustrate how adapted BSL3-atomic force microscopy is a remarkable toolbox for rapid and direct virus identification and characterization.

SARS-CoV-2: Problems and uncertainties

The virus morphology and structure are studied first, in a second part to update the diagnostic laboratory techniques, the problems they pose and the current uncertainties of many of them.

Repurposing Papaverine as an Antiviral Agent against Influenza Viruses and Paramyxoviruses

ABSTRACT Influenza viruses are highly infectious and are the leading cause of human respiratory diseases and may trigger severe epidemics and occasional pandemics. Although antiviral drugs against influenza viruses have been developed, there is an urgent need to design new strategies to develop influenza virus inhibitors due to the increasing resistance of viruses toward currently available drugs. In this study, we examined the antiviral activity of natural compounds against the following influenza virus strains: A/WSN/33 (H1N1), A/Udorn/72 (H3N2), and B/Lee/40. Papaverine (a nonnarcotic alkaloid that has been used for the treatment of heart disease, impotency, and psychosis) was found to be an effective inhibitor of multiple strains of influenza virus. Kinetic studies demonstrated that papaverine inhibited influenza virus infection at a late stage in the virus life cycle. An alteration in influenza virus morphology and viral ribonucleoprotein (vRNP) localization was observed as an effect of papaverine treatment. Papaverine is a well-known phosphodiesterase inhibitor and also modifies the mitogen-activated protein kinase (MAPK) pathway by downregulating the phosphorylation of MEK and extracellular signal-regulated kinase (ERK). Thus, the modulation of host cell signaling pathways by papaverine may be associated with the nuclear retention of vRNPs and the reduction of influenza virus titers. Interestingly, papaverine also inhibited paramyxoviruses parainfluenza virus 5 (PIV5), human parainfluenza virus 3 (HPIV3), and respiratory syncytial virus (RSV) infections. We propose that papaverine can be a potential candidate to be used as an antiviral agent against a broad range of influenza viruses and paramyxoviruses. IMPORTANCE Influenza viruses are important human pathogens that are the causative agents of epidemics and pandemics. Despite the availability of an annual vaccine, a large number of cases occur every year globally. Here, we report that papaverine, a vasodilator, shows inhibitory action against various strains of influenza virus as well as the paramyxoviruses PIV5, HPIV3, and RSV. A significant effect of papaverine on the influenza virus morphology was observed. Papaverine treatment of influenza-virus-infected cells resulted in the inhibition of virus at a later time in the virus life cycle through the suppression of nuclear export of vRNP and also interfered with the host cellular cAMP and MEK/ERK cascade pathways. This study explores the use of papaverine as an effective inhibitor of both influenza viruses as well as paramyxoviruses.

Complete Genome Sequence of vB_BveP-Goe6, a Virus Infecting Bacillus velezensis FZB42

ABSTRACT The new virus vB_BveP-Goe6 was isolated on the host organism Bacillus velezensis FZB42. The virus morphology indicated its association with the genus Phi29virus . The genome of vB_BveP-Goe6 (19,105 bp) comprises a linear chromosome with a GC content of 39.99%. The genome harbors 26 putative protein-coding genes and a noncoding packaging RNA.