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1.
Int J Environ Res Public Health ; 19(1)2021 12 29.
Article in English | MEDLINE | ID: covidwho-1580792

ABSTRACT

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/cm2 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.


Subject(s)
Ambulances , COVID-19 , Disinfection , Humans , SARS-CoV-2 , Ultraviolet Rays
2.
Front Immunol ; 12: 750386, 2021.
Article in English | MEDLINE | ID: covidwho-1515534

ABSTRACT

Antibodies targeting Receptor Binding Domain (RBD) of SARS-CoV-2 have been suggested to account for the majority of neutralizing activity in COVID-19 convalescent sera and several neutralizing antibodies (nAbs) have been isolated, characterized and proposed as emergency therapeutics in the form of monoclonal antibodies (mAbs). However, SARS-CoV-2 variants are rapidly spreading worldwide from the sites of initial identification. The variants of concern (VOC) B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma) and B.1.167.2 (Delta) showed mutations in the SARS-CoV-2 spike protein potentially able to cause escape from nAb responses with a consequent reduction of efficacy of vaccines and mAbs-based therapy. We produced the recombinant RBD (rRBD) of SARS-CoV-2 spike glycoprotein from the Wuhan-Hu 1 reference sequence in a mammalian system, for mice immunization to isolate new mAbs with neutralizing activity. Here we describe four mAbs that were able to bind the rRBD in Enzyme-Linked Immunosorbent Assay and the transmembrane full-length spike protein expressed in HEK293T cells by flow cytometry assay. Moreover, the mAbs recognized the RBD in supernatants of SARS-CoV-2 infected VERO E6 cells by Western Blot under non-reducing condition or in supernatants of cells infected with lentivirus pseudotyped for spike protein, by immunoprecipitation assay. Three out of four mAbs lost their binding efficiency to completely N-deglycosylated rRBD and none was able to bind the same recombinant protein expressed in Escherichia coli, suggesting that the epitopes recognized by three mAbs are generated by the conformational structure of the glycosylated native protein. Of particular relevance, three mAbs were able to inhibit Wuhan SARS-CoV-2 infection of VERO E6 cells in a plaque-reduction neutralization test and the Wuhan SARS-CoV-2 as well as the Alpha, Beta, Gamma and Delta VOC in a pseudoviruses-based neutralization test. These mAbs represent important additional tools for diagnosis and therapy of COVID-19 and may contribute to the understanding of the functional structure of SARS-CoV-2 RBD.


Subject(s)
Antibodies, Monoclonal/pharmacology , Antibodies, Neutralizing/pharmacology , Antibodies, Viral/pharmacology , Epitopes/immunology , SARS-CoV-2/drug effects , Spike Glycoprotein, Coronavirus/immunology , Angiotensin-Converting Enzyme 2/genetics , Animals , Binding Sites, Antibody/immunology , COVID-19/drug therapy , Cell Line, Tumor , Chlorocebus aethiops , Female , Glycosylation , HEK293 Cells , Humans , Mice, Inbred BALB C , Neutralization Tests , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Vero Cells
3.
Antioxidants (Basel) ; 10(11)2021 Nov 10.
Article in English | MEDLINE | ID: covidwho-1512080

ABSTRACT

The COVID-19 pandemic represents an unprecedented global emergency. Despite all efforts, COVID-19 remains a threat to public health, due to the complexity of mass vaccination programs, the lack of effective drugs, and the emergence of new variants. A link has recently been found between the risk of developing a severe COVID-19 infection and a high level of oxidative stress. In this context, we have focused our attention on natural compounds with the aim of finding molecules capable of acting through a dual virucidal-antioxidant mechanism. In particular, we studied the potential of grapefruit seed extracts (GSE) and their main components, belonging to the class of limonoids. Using chemical and biological approaches including isolation and purification of GSE, antioxidant and virucidal assays, we have shown that grapefruit seed constituents, belonging to the class of limonoids, are endowed with remarkable virucidal, antioxidant and mitoprotective activity.

4.
Sci Rep ; 11(1): 21725, 2021 11 05.
Article in English | MEDLINE | ID: covidwho-1504567

ABSTRACT

SARS-CoV-2 enters the intestine by the spike protein binding to angiotensin-converting enzyme 2 (ACE2) receptors in enterocyte apical membranes, leading to diarrhea in some patients. Early treatment of COVID-19-associated diarrhea could relieve symptoms and limit viral spread within the gastrointestinal (GI) tract. Diosmectite, an aluminomagnesium silicate adsorbent clay with antidiarrheal effects, is recommended in some COVID-19 management protocols. In rotavirus models, diosmectite prevents pathogenic effects by binding the virus and its enterotoxin. We tested the trapping and anti-inflammatory properties of diosmectite in a SARS-CoV-2 model. Trapping effects were tested in Caco-2 cells using spike protein receptor-binding domain (RBD) and heat-inactivated SARS-CoV-2 preparations. Trapping was assessed by immunofluorescence, alone or in the presence of cells. The effect of diosmectite on nuclear factor kappa B (NF-kappaB) activation and CXCL10 secretion induced by the spike protein RBD and heat-inactivated SARS-CoV-2 were analyzed by Western blot and ELISA, respectively. Diosmectite bound the spike protein RBD and SARS-CoV-2 preparation, and inhibited interaction of the spike protein RBD with ACE2 receptors on the Caco-2 cell surface. Diosmectite exposure also inhibited NF-kappaB activation and CXCL10 secretion. These data provide direct evidence that diosmectite can bind SARS-CoV-2 components and inhibit downstream inflammation, supporting a mechanistic rationale for consideration of diosmectite as a management option for COVID-19-associated diarrhea.


Subject(s)
COVID-19/drug therapy , Chemokine CXCL10/metabolism , NF-kappa B p50 Subunit/metabolism , SARS-CoV-2 , Silicates/chemistry , Adsorption , Aluminum Compounds/chemistry , Angiotensin-Converting Enzyme 2/metabolism , Anti-Inflammatory Agents , Binding Sites , Caco-2 Cells , Chromatography, Liquid , Clay , Diarrhea/etiology , Diarrhea/therapy , Enterocytes/metabolism , Gastroenterology , Humans , Magnesium Compounds/chemistry , Mass Spectrometry , Molecular Docking Simulation , Molecular Dynamics Simulation , Protein Binding/drug effects , Protein Domains , Rotavirus , Silicates/metabolism
6.
Ann Ist Super Sanita ; 57(2): 121-127, 2021.
Article in English | MEDLINE | ID: covidwho-1271021

ABSTRACT

INTRODUCTION: The Istituto Superiore di Sanità (ISS) has been asked for rapid technical and scientific advice to the State and Regions during Sars-CoV-2 pandemic preparedness. METHODS: An ad hoc Working Group on Scientific Literature updates (WG SL) was set up at ISS (March-May 2020) to screen pre-prints and peer reviewed papers from arXiv, medRxiv, bioRxiv, and Pubmed to provide a real time knowledge and empirical evidence addressed to health-workers. RESULTS: The WG SL screened a total of 4,568 pre-prints and 15,590 peer reviewed papers, delivered as daily summary report of pre-print selection for ISS President activity in the National Scientific Technical Committee framework and a weekly open access publication (COVID Contents) on peer-reviewed papers of interest for health professionals, monitored by a satisfaction questionnaire. CONCLUSIONS: Promoting heath literacy, with a cross-cutting approach is a powerful heritage of Public Health Institutes and a proven effective non pharmacological intervention.


Subject(s)
COVID-19 , Health Personnel , Informatics , Pandemics , Civil Defense , Evidence-Based Medicine , Health Literacy , Humans , Italy
7.
Clin Microbiol Infect ; 27(2): 289.e5-289.e7, 2021 Feb.
Article in English | MEDLINE | ID: covidwho-909116

ABSTRACT

OBJECTIVES: To evaluate whether the increase of temperature can influence the environmental endurance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: Virus was inoculated on a plastic surface and harvested at predefined time-points in parallel at 20°C-25°C (room temperature; RT) and at 28°C (June temperature; JT). Samples were tested by TCID50 titres on Vero cells. RESULTS: Our results confirm that fomite transmission of the emerging SARS-CoV-2 is possible: the virus reserved its ability to infect cells for up to 84 hours at both RT and JT on a plastic surface, with TCID50 viral titres of 0.67 and 0.25 log10, respectively. At RT, an important reduction in the viral titre, from 4 log10 to 3 log10 TCID50, was observed during the first 24-36 hours. At JT, the same decay was observed more rapidly (between 8 and 12 hours), The rate of viral inactivation by D-value was 24.74 hours at RT and 12.21 hours at JT. CONCLUSIONS: This remarkable difference between the two temperatures suggests that virus vitality can be influenced by the environmental temperature and that the hot season could reduce the probability of COVID-19 transmission.


Subject(s)
Environmental Microbiology , SARS-CoV-2/physiology , Animals , COVID-19/transmission , COVID-19/virology , Chlorocebus aethiops , Fomites/virology , Humans , Microbial Viability , Temperature , Vero Cells , Viral Load , Virus Inactivation
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