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Since late 2023, the Metropolitan City of Milan and surrounding areas (northern Italy) have been experiencing a resurgence of measles, with most cases detected starting from January 2024. During this brief period, we observed measles in travellers from endemic areas, participants in international events, vaccinees and healthcare workers. Indigenous cases have also been identified. Even though we have not yet identified large and disruptive outbreaks, strengthening surveillance and vaccination activities is pivotal to help limit the impact of measles spread.
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Virus del Sarampión , Sarampión , Humanos , Virus del Sarampión/genética , Sarampión/epidemiología , Sarampión/prevención & control , Brotes de Enfermedades , Vacunación , Italia/epidemiología , Vacuna AntisarampiónRESUMEN
As a reference laboratory for measles and rubella surveillance in Lombardy, we evaluated the association between SARS-CoV-2 infection and measles-like syndromes, providing preliminary evidence for undetected early circulation of SARS-CoV-2. Overall, 435 samples from 156 cases were investigated. RNA from oropharyngeal swabs (N = 148) and urine (N = 141) was screened with four hemi-nested PCRs and molecular evidence for SARS-CoV-2 infection was found in 13 subjects. Two of the positive patients were from the pandemic period (2/12, 16.7%, March 2020-March 2021) and 11 were from the pre-pandemic period (11/44, 25%, August 2019-February 2020). Sera (N = 146) were tested for anti-SARS-CoV-2 IgG, IgM, and IgA antibodies. Five of the RNA-positive individuals also had detectable anti-SARS-CoV-2 antibodies. No strong evidence of infection was found in samples collected between August 2018 and July 2019 from 100 patients. The earliest sample with evidence of SARS-CoV-2 RNA was from September 12, 2019, and the positive patient was also positive for anti-SARS-CoV-2 antibodies (IgG and IgM). Mutations typical of B.1 strains previously reported to have emerged in January 2020 (C3037T, C14408T, and A23403G), were identified in samples collected as early as October 2019 in Lombardy. One of these mutations (C14408T) was also identified among sequences downloaded from public databases that were obtained by others from samples collected in Brazil in November 2019. We conclude that a SARS-CoV-2 progenitor capable of producing a measles-like syndrome may have emerged in late June-late July 2019 and that viruses with mutations characterizing B.1 strain may have been spreading globally before the first Wuhan outbreak. Our findings should be complemented by high-throughput sequencing to obtain additional sequence information. We highlight the importance of retrospective surveillance studies in understanding the early dynamics of COVID-19 spread and we encourage other groups to perform retrospective investigations to seek confirmatory proofs of early SARS-CoV-2 circulation.
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COVID-19 , Sarampión , Anticuerpos Antivirales , COVID-19/epidemiología , Humanos , Inmunoglobulina A , Inmunoglobulina G , Inmunoglobulina M , Italia/epidemiología , ARN Viral/genética , Estudios Retrospectivos , SARS-CoV-2/genéticaRESUMEN
Whole genome sequences of SARS-CoV-2 obtained from two patients, a Chinese tourist visiting Rome and an Italian, were compared with sequences from Europe and elsewhere. In a phylogenetic tree, the Italian patient's sequence clustered with sequences from Germany while the tourist's sequence clustered with other European sequences. Some additional European sequences in the tree segregated outside the two clusters containing the patients' sequences. This suggests multiple SARS-CoV-2 introductions in Europe or virus evolution during circulation.
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Betacoronavirus/genética , Infecciones por Coronavirus/diagnóstico , Coronavirus/genética , Genoma Viral/genética , Neumonía Viral/diagnóstico , ARN Viral/genética , Síndrome Respiratorio Agudo Grave/diagnóstico , Viaje , Secuenciación Completa del Genoma/métodos , Betacoronavirus/aislamiento & purificación , COVID-19 , China , Coronavirus/clasificación , Coronavirus/aislamiento & purificación , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/transmisión , Alemania , Humanos , Italia , Epidemiología Molecular , Pandemias , Filogenia , Neumonía Viral/epidemiología , Neumonía Viral/transmisión , Mutación Puntual , ARN Viral/aislamiento & purificación , SARS-CoV-2 , Síndrome Respiratorio Agudo Grave/virologíaRESUMEN
Background: During recent years, various mumps outbreaks have occurred among populations vaccinated for mumps worldwide. In Italy, improving routine coverage with two doses of measles, mumps and rubella (MMR) vaccine is one of the key strategies to eliminate measles and rubella. To monitor the effect of the vaccination programme on the population, the surveillance of these vaccine-preventable diseases has been implemented. This provided the opportunity to evaluate the accuracy of the clinical diagnosis of those diseases, including mumps. In fact, vaccinated children may develop a variety of diseases caused by a series of different viruses [Epstein-Barr virus (EBV), parainfluenza virus types 1-3, adenoviruses, herpes virus and parvovirus B19] whose symptoms (i.e. swelling of parotid glands) may mimic mumps. For this reason, laboratory diagnosis is essential to confirm clinical suspicion. Methods: The accuracy of clinical diagnosis of mumps was evaluated by differential diagnosis on EBV in Italy, a country at low incidence of mumps. This retrospective study investigated whether the etiology of 131 suspected mumps cases with a negative molecular/serological result for mumps virus, obtained from 2007 to 2016, were due to EBV, in order to establish a diagnosis. Results: Differential diagnosis revealed a EBV positivity rate of 19.8% and all cases were caused by EBV type 1. Conclusions: This study confirms the importance of a lab based differential diagnosis that can discriminate between different infectious diseases presenting with symptoms suggestive of mumps and, in particular, emphasize the importance to discriminate between mumps and EBV-related mononucleosis.
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Errores Diagnósticos/estadística & datos numéricos , Infecciones por Virus de Epstein-Barr/diagnóstico , Infecciones por Virus de Epstein-Barr/epidemiología , Herpesvirus Humano 4/aislamiento & purificación , Paperas/diagnóstico , Adolescente , Adulto , Niño , Preescolar , Diagnóstico Diferencial , Femenino , Humanos , Lactante , Italia/epidemiología , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Reproducibilidad de los Resultados , Estudios Retrospectivos , Incertidumbre , Adulto JovenRESUMEN
BACKGROUND: Arthropod-borne viruses (Arbovirus) play an important role among emerging and re-emerging infectious diseases and in the spreading of infections in new geographic areas. Although some arboviral infections may be asymptomatic or mild flu-like illnesses, many occur as severe forms of meningitis and meningoencephalitis. OBJECTIVES: To assess whether arboviral infections may be associated with occupational risk, in a population of agricultural and forestry workers potentially at high risk for arthropods bite and sting. METHODS: A seroprevalence survey for arboviruses belonging to the genera Flaviviruses (West Nile, Tick-borne encephalitis and Usutu viruses) and Phlebovirus (Toscana virus) was carried out in Grosseto province (Tuscany, Italy). One hundred and one serum samples of occupationally exposed workers and 100 serum samples of not exposed workers were analyzed using commercial and home-made serological assays. Serological data were obtained in 2012 and analyzed according to demographic characteristics, recollection of insect-bites, and time spent in outdoor activities. RESULTS: A total seropositivity of 10% (21/201) was observed for Toscana virus. No difference in seroprevalence for Toscana virus was observed among the exposed (10/101) versus the not exposed (11/100) workers. No seropositivity for West Nile, Usutu and Tick-borne encephalitis viruses was detected. CONCLUSIONS: Although circulation of Toscana virus is recognized in the study area, our results did not reveal a higher risk for workers exposed to arthropods bite and sting. Health surveillance programs remain useful to monitor the potential emergence of arboviruses.
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Agricultura/estadística & datos numéricos , Infecciones por Arbovirus/epidemiología , Enfermedades Profesionales/epidemiología , Exposición Profesional/efectos adversos , Adulto , Animales , Infecciones por Arbovirus/sangre , Infecciones por Arbovirus/virología , Arbovirus/aislamiento & purificación , Encefalitis Transmitida por Garrapatas/epidemiología , Femenino , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Enfermedades Profesionales/sangre , Enfermedades Profesionales/virología , Vigilancia de la Población , Prevalencia , Estudios Retrospectivos , Factores de Riesgo , Estudios Seroepidemiológicos , Encuestas y Cuestionarios , GarrapatasRESUMEN
In 2013, the majority of the WHO/EUR countries reported an annual incidence of >1 case per one million population indicating that the elimination target is far from being met. Thus, there is the urgent need to uncover and analyze chains of measles virus (MV) transmission with the objective to identify vulnerable groups and avoid possible routes of introduction of MV variants in the European population. The analysis of molecular epidemiology of MV B3 strains identified in 2014 has shown that four different variants co-circulated in Italy, including the strain that caused a cruise-line ship outbreak at the beginning of the year.
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Variación Genética , Virus del Sarampión/genética , Sarampión/epidemiología , Sarampión/virología , Brotes de Enfermedades , Pruebas con Sangre Seca , Genotipo , Humanos , Incidencia , Italia/epidemiología , Sarampión/etnología , Sarampión/transmisión , Virus del Sarampión/clasificación , Virus del Sarampión/fisiología , Filogenia , ARN Viral/genética , Orina/virologíaRESUMEN
Natural products are a rich source of bioactive molecules that have potential pharmacotherapeutic applications. In this study, we focused on Artemisia annua (A. annua) and its enriched extracts which were biologically evaluated in vitro as virucidal, antiviral, and antioxidant agents, with a potential application against the COVID-19 infection. The crude extract showed virucidal, antiviral and antioxidant effects in concentrations that did not affect cell viability. Scopoletin, arteannuin B and artemisinic acid (single fractions isolated from A. annua) exerted a considerable virucidal and antiviral effect in vitro starting from a concentration of 50 µg/mL. Data from Surface Plasmon Resonance (SPR) showed that the inhibition of the viral infection was due to the interaction of these compounds with the 3CLpro and Spike proteins of SARS-CoV-2, suggesting that the main interaction of compounds may interfere with the viral pathways during the insertion and the replication process. The present study suggests that natural extract of A. annua and its components could have a key role as antioxidants and antiviral agents and support the fight against SARS-CoV-2 variants and other possible emerging Coronaviruses.
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Artemisia annua , COVID-19 , SARS-CoV-2 , Antioxidantes/farmacología , Antioxidantes/metabolismo , Artemisia annua/metabolismo , Extractos Vegetales/farmacología , Extractos Vegetales/metabolismo , Antivirales/farmacología , Antivirales/metabolismoRESUMEN
COronaVIrus Disease 2019 (COVID-19) is a newly emerging infectious disease that spread across the world, caused by the novel coronavirus Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2). Despite the advancements in science that led to the creation of the vaccine, there is still an urgent need for new antiviral drugs effective against SARS-CoV-2. This study aimed to investigate the antiviral effect of Paulownia tomentosa Steud extract against SARS-CoV-2 and to evaluate its antioxidant properties, including respiratory smooth muscle relaxant effects. Our results showed that P. tomentosa extract can inhibit viral replication by directly interacting with both the 3-chymotrypsin-like protease and spike protein. In addition, the phyto complex does not reduce lung epithelial cell viability and exerts a protective action in those cells damaged by tert-butyl hydroperoxide , a toxic agent able to alter cells' functions via increased oxidative stress. These data suggest the potential role of P. tomentosa extract in COVID-19 treatment, since this extract is able to act both as an antiviral and a cytoprotective agent in vitro.
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COVID-19 , Humanos , Antivirales/uso terapéutico , SARS-CoV-2 , Antioxidantes/farmacología , Tratamiento Farmacológico de COVID-19 , Extractos Vegetales/farmacología , Músculo LisoRESUMEN
The emergence of the new pathogen SARS-CoV-2 determined a rapid need for monoclonal antibodies (mAbs) to detect the virus in biological fluids as a rapid tool to identify infected individuals to be treated or quarantined. The majority of commercially available antigenic tests for SARS-CoV-2 rely on the detection of N antigen in biologic fluid using anti-N antibodies, and their capacity to specifically identify subjects infected by SARS-CoV-2 is questionable due to several structural analogies among the N proteins of different coronaviruses. In order to produce new specific antibodies, BALB/c mice were immunized three times at 20-day intervals with a recombinant spike (S) protein. The procedure used was highly efficient, and 40 different specific mAbs were isolated, purified and characterized, with 13 ultimately being selected for their specificity and lack of cross reactivity with other human coronaviruses. The specific epitopes recognized by the selected mAbs were identified through a peptide library and/or by recombinant fragments of the S protein. In particular, the selected mAbs recognized different linear epitopes along the S1, excluding the receptor binding domain, and along the S2 subunits of the S protein of SARS-CoV-2 and its major variants of concern. We identified combinations of anti-S mAbs suitable for use in ELISA or rapid diagnostic tests, with the highest sensitivity and specificity coming from proof-of-concept tests using recombinant antigens, SARS-CoV-2 or biological fluids from infected individuals, that represent important additional tools for the diagnosis of COVID-19.
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The current SARS-CoV-2 pandemic and the likelihood that new coronavirus strains will emerge in the immediate future point out the urgent need to identify new pan-coronavirus inhibitors. Strigolactones (SLs) are a class of plant hormones with multifaceted activities whose roles in plant-related fields have been extensively explored. Recently, we proved that SLs also exert antiviral activity toward herpesviruses, such as human cytomegalovirus (HCMV). Here we show that the synthetic SLs TH-EGO and EDOT-EGO impair ß-coronavirus replication including SARS-CoV-2 and the common cold human coronavirus HCoV-OC43. Interestingly, in silico simulations suggest the binding of SLs in the SARS-CoV-2 main protease (Mpro) active site, and this was further confirmed by an in vitro activity assay. Overall, our results highlight the potential efficacy of SLs as broad-spectrum antivirals against ß-coronaviruses, which may provide the rationale for repurposing this class of hormones for the treatment of COVID-19 patients.
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COVID-19 , Humanos , Antivirales/farmacología , Antivirales/química , SARS-CoV-2 , Péptido HidrolasasRESUMEN
BACKGROUND: The European Regional Office of the World Health Organization (WHO/Europe) developed a strategic approach to halt the indigenous transmission of measles in its 53 Member States by 2015. In view of the goal of measles elimination, it is of great importance to assess the circulation of wild-type measles virus (MV). Genetic analysis is indispensable to understand the epidemiology of measles. METHODS: Urine and saliva samples were collected between May 2002 and December 2007, in order to find the origins and routes of wild type measles virus circulation. RT-PCR was performed on a total of 414 clinical samples of patients from different Italian regions. The results confirmed the genome presence in 199 samples, out of which 179 were sequenced. The sequences were genotyped by comparing the fragment coding for the carboxyl terminus of the nucleoprotein (450 nucleotides) with that one of the WHO reference strains. RESULTS: From the year 2002 to the year 2007 phylogenetic analysis of measles sequences showed a predominant circulation of the D7 genotype in the Italian territory for the years 2002-2004. This genotype was replaced by D4 and B3 genotypes in the biennium 2006-2007. During the same period C2, A, D5 and D8 genotypes were also detected. CONCLUSIONS: Genetic characterization of wild-type MV provides a means to study the transmission pathways of the virus, and is an essential component of laboratory-based surveillance. Knowledge of currently circulating measles virus genotype in Italy will help in monitoring the success of the measles elimination programme and will contribute to evaluate the effectiveness of future vaccination campaigns.
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Virus del Sarampión/clasificación , Virus del Sarampión/genética , Sarampión/epidemiología , Sarampión/virología , Análisis por Conglomerados , Variación Genética , Genotipo , Humanos , Italia/epidemiología , Virus del Sarampión/aislamiento & purificación , Epidemiología Molecular , Datos de Secuencia Molecular , Filogenia , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Saliva/virología , Análisis de Secuencia de ADN , Orina/virologíaRESUMEN
Toscana sandfly fever virus (TOSV) is an arthropod-borne virus transmitted to humans by sandfly vectors. It has been associated with human cases of meningitis and meningo-encephalitis mainly occurring during the warm season. We performed a retrospective serological study to evaluate TOSV circulation in Palermo, Sicily, and to compare TOSV seroprevalence in patients with neurological symptoms and in a control group of patients without neurological symptoms. When sera from 155 patients with and without neurological symptoms were evaluated, the rate of overall TOSV IgG reactivity was 17.4%. Patients with neurological symptoms showed a higher percentage of TOSV IgG positivity than control patients (25% versus 10.8%). TOSV exposure was confirmed by virus neutralization tests which also detected a Naples virus (SFNV) infection. TOSV should be considered as an etiologic agent in the differential diagnosis of fever and meningo-encephalitis in Sicily.
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Anticuerpos Antivirales/inmunología , Enfermedades del Sistema Nervioso/inmunología , Virus de Nápoles de la Fiebre de la Mosca de los Arenales/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades del Sistema Nervioso/epidemiología , Enfermedades del Sistema Nervioso/etiología , Enfermedades del Sistema Nervioso/virología , Estudios Retrospectivos , Estudios Seroepidemiológicos , Sicilia/epidemiologíaRESUMEN
Hantaviruses include several zoonotic pathogens that cause different syndromes in humans, with mortality rates ranging from 12 to 40%. Most commonly, humans get infected through the inhalation of aerosols or dust particles contaminated with virus-containing rodent excreta. Hantaviruses are specifically associated with the host species, and human cases depend on the presence and the dynamics of reservoir hosts. In this letter, we report the identification of Dobrava-Belgrade virus (DOBV) in the yellow-necked mouse (Apodemus flavicollis) from Italy. The virus was detected in the mountainous area of the province of Udine, bordering Austria and Slovenia, during an event of enhanced mortality in wild mice and voles. Despite serological evidence in rodents and humans that suggested the circulation of hantaviruses in Italy since 2000, this is the first virological confirmation of the infection. Phylogenetic analyses across the whole genome of the two detected viruses confirmed the host-specificity of DOBV sub-species and showed the highest identity with viruses identified in Slovenia and Croatia from both A. flavicollis and humans, with no signs of reassortment. These findings highlight the need for ecologists, veterinarians and medical doctors to come together in a coordinated approach in full compliance with the One Health concept.
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Infecciones por Hantavirus , Orthohantavirus , Animales , Austria , Italia/epidemiología , Ratones , Murinae , FilogeniaRESUMEN
Subacute sclerosing panencephalitis (SSPE) is a late complication of measles virus infection that occurs in previously healthy children. This disease has no specific cure and is associated with a high degree of disability and mortality. In recent years, there has been an increase in its incidence in relation to a reduction in vaccination adherence, accentuated by the COVID-19 pandemic. In this article, we take stock of the current evidence on SSPE and report our personal clinical experience. We emphasise that, to date, the only effective protection strategy against this disease is vaccination against the measles virus.
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COVID-19 , Sarampión , Panencefalitis Esclerosante Subaguda , COVID-19/prevención & control , Niño , Humanos , Sarampión/epidemiología , Sarampión/prevención & control , Virus del Sarampión , Pandemias , Panencefalitis Esclerosante Subaguda/epidemiología , Panencefalitis Esclerosante Subaguda/etiología , Panencefalitis Esclerosante Subaguda/prevención & control , Vacunación/efectos adversosRESUMEN
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.
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Microbiología Ambiental , SARS-CoV-2/fisiología , Animales , COVID-19/transmisión , COVID-19/virología , Chlorocebus aethiops , Fómites/virología , Humanos , Viabilidad Microbiana , Temperatura , Células Vero , Carga Viral , Inactivación de VirusRESUMEN
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.
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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.
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Ambulancias , COVID-19 , Desinfección , Humanos , SARS-CoV-2 , Rayos UltravioletaRESUMEN
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.