The appearance of new respiratory virus infections in humans with epidemic or pandemic potential has underscored the urgent need for effective broad-spectrum antivirals (BSAs). Bioactive compounds derived from plants may provide a natural source of new BSA candidates. Here, we investigated the novel phytocomplex formulation SP4™ as a candidate direct-acting BSA against major current human respiratory viruses, including coronaviruses and influenza viruses.
View Article and Find Full Text PDFBioassays are the main tool to decipher bioactivities from natural resources thus their selection and quality are critical for optimal bioprospecting. They are used both in the early stages of compounds isolation/purification/identification, and in later stages to evaluate their safety and efficacy. In this review, we provide a comprehensive overview of the most common bioassays used in the discovery and development of new bioactive compounds with a focus on marine bioresources.
View Article and Find Full Text PDFHuman respiratory syncytial virus (RSV) is an important cause of acute lower respiratory infections, for which no effective drugs are currently available. The development of new effective anti-RSV agents is therefore an urgent priority, and Host-Targeting Antivirals (HTAs) can be considered to target RSV infections. As a contribution to this antiviral avenue, we have characterized the molecular mechanisms of the anti-RSV activity of MEDS433, a new inhibitor of human dihydroorotate dehydrogenase (hDHODH), a key cellular enzyme of de novo pyrimidine biosynthesis.
View Article and Find Full Text PDFThe human cytomegalovirus (HCMV) US12 gene family contributes to virus-host interactions by regulating the virus' cell tropism and its evasion of host innate immune responses. US21, one of the 10 US12 genes (US12-US21), is a descendant of a captured cellular transmembrane BAX inhibitor motif-containing gene. It encodes a 7TMD endoplasmic reticulum (ER)-resident viroporin (pUS21) capable of reducing the Ca content of ER stores, which, in turn, protects cells against apoptosis.
View Article and Find Full Text PDFcauses a wide spectrum of diseases varying from mild to life threatening, despite antibiotic treatment. Nanoparticle application could facilitate the foreign pathogen fight by increasing the antimicrobial effectiveness and reducing their adverse effects. Here, we designed and produced erythromycin-loaded chitosan nanodroplets (Ery-NDs), both oxygen-free and oxygen-loaded.
View Article and Find Full Text PDFIntroduction: In the vineyard, yeast communities impact the ripening and fermentation of grapes and are influenced by geographical location, climate, and soil characteristics. Despite the great advancement in our knowledge of the vineyard mycobiota, a key step of the process leading to the definition of the vineyard yeast community is still poorly understood: if geography, climate, and soil influence the mycobiota, potentially through selection, where do the yeast originate from, and how can they reach the vineyard? In this perspective, it is currently acknowledged that forests host several yeast species and that insects, particularly social wasps, can vector and maintain the yeasts known to populate the vineyard. Alas, the conveyance, fostered by insects, of yeasts from the forest to the vineyard has not been proven yet.
View Article and Find Full Text PDFDental implants have dramatically changed the rehabilitation procedures in dental prostheses but are hindered by the possible onset of peri-implantitis. This paper aims to assess whether an anodization process applied to clinically used surfaces could enhance the adhesion of fibroblasts and reduce bacterial adhesion using as a reference the untreated machined surface. To this purpose, four different surfaces were prepared: (i) machined (MAC), (ii) machined and anodized (Y-MAC), (iii) anodized after sand-blasting and acid etching treatment (Y-SL), and (iv) anodized after double acid etching (Y-DM).
View Article and Find Full Text PDFThe pharmacological management of influenza virus (IV) infections still poses a series of challenges due to the limited anti-IV drug arsenal. Therefore, the development of new anti-influenza agents effective against antigenically different IVs is therefore an urgent priority. To meet this need, host-targeting antivirals (HTAs) can be evaluated as an alternative or complementary approach to current direct-acting agents (DAAs) for the therapy of IV infections.
View Article and Find Full Text PDFBackground: A few studies suggest that particulate matter (PM) exposure might play a role in bronchiolitis. However, available data are mostly focused on the risk of hospitalization and come from retrospective studies that provided conflicting results. This prospective study investigated the association between PM (PM and PM ) exposure and the severity of bronchiolitis.
View Article and Find Full Text PDFThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the coronavirus disease 2019 (COVID-19), ranging from asymptomatic conditions to severe/fatal lung injury and multi-organ failure. Growing evidence shows that the nasopharyngeal microbiota composition may predict the severity of respiratory infections and may play a role in the protection from viral entry and the regulation of the immune response to the infection. In the present study, we have characterized the nasopharyngeal bacterial microbiota (BNM) composition and have performed factor analysis in a group of 54 asymptomatic/paucisymptomatic subjects who tested positive for nasopharyngeal swab SARS-CoV-2 RNA and/or showed anti-RBD-IgG positive serology at the enrolment.
View Article and Find Full Text PDFPurpose: Medium versus low weight (MW vs LW) chitosan-shelled oxygen-loaded nanodroplets (cOLNDs) and oxygen-free nanodroplets (cOFNDs) were comparatively challenged for biocompatibility on human keratinocytes, for antimicrobial activity against four common infectious agents of chronic wounds (CWs) - methicillin-resistant (MRSA), and - and for their physical interaction with cell walls/membranes.
Methods: cNDs were characterized for morphology and physico-chemical properties by microscopy and dynamic light scattering. In vitro oxygen release from cOLNDs was measured through an oximeter.
The aim was to evaluate the antibacterial efficacy and penetration depth into dentinal tubules of a solution of chitosan nanodroplets (NDs) loaded with Benzalkonium Chloride (BAK). Seventy-two human single-root teeth with fully formed apex were used. Cylindrical root dentin blocks were longitudinally sectioned and enlarged to a size of a Gates Glidden drill #4.
View Article and Find Full Text PDFChronic wounds (CWs) are typically characterized by persistent hypoxia, exacerbated inflammation, and impaired skin tissue remodeling. Additionally, CWs are often worsened by microbial infections. Oxygen-loaded nanobubbles (OLNBs), displaying a peculiar structure based on oxygen-solving perfluorocarbons such as perfluoropentane in the inner core and polysaccharydes including chitosan in the outer shell, have proven effective in delivering oxygen to hypoxic tissues.
View Article and Find Full Text PDFBackground: Milk is considered an important source of bioactive peptides, which can be produced by endogenous or starter bacteria, such as lactic acid bacteria, that are considered effective and safe producers of food-grade bioactive peptides. Among the various types of milk, donkey milk has been gaining more and more attention for its nutraceutical properties.
Methods: 17D10 and subsp.
Although coronaviruses (CoVs) have long been predicted to cause zoonotic diseases and pandemics with high probability, the lack of effective anti-pan-CoVs drugs rapidly usable against the emerging SARS-CoV-2 actually prevented a promptly therapeutic intervention for COVID-19. Development of host-targeting antivirals could be an alternative strategy for the control of emerging CoVs infections, as they could be quickly repositioned from one pandemic event to another. To contribute to these pandemic preparedness efforts, here we report on the broad-spectrum CoVs antiviral activity of MEDS433, a new inhibitor of the human dihydroorotate dehydrogenase (DHODH), a key cellular enzyme of the de novo pyrimidine biosynthesis pathway.
View Article and Find Full Text PDFEngineering microbial strains combining efficient lignocellulose metabolization and high-value chemical production is a cutting-edge strategy towards cost-sustainable 2 generation biorefining. Here, protein components of the Clostridium cellulovorans cellulosome were introduced in Lactococcus lactis IL1403, one of the most efficient lactic acid producers but unable to directly ferment cellulose. Cellulosomes are protein complexes with high cellulose depolymerization activity whose synergistic action is supported by scaffolding protein(s) (i.
View Article and Find Full Text PDFWe recently reported that some clinically approved antifungal drugs are potent inhibitors of human cytomegalovirus (HCMV). Here, we report the broad-spectrum activity against HCMV of isavuconazole (ICZ), a new extended-spectrum triazolic antifungal drug. ICZ inhibited the replication of clinical isolates of HCMV as well as strains resistant to the currently available DNA polymerase inhibitors.
View Article and Find Full Text PDFEmergence of drug resistance and adverse effects often affect the efficacy of nucleoside analogues in the therapy of Herpes simplex type 1 (HSV-1) and type 2 (HSV-2) infections. Host-targeting antivirals could therefore be considered as an alternative or complementary strategy in the management of HSV infections. To contribute to this advancement, here we report on the ability of a new generation inhibitor of a key cellular enzyme of de novo pyrimidine biosynthesis, the dihydroorotate dehydrogenase (DHODH), to inhibit HSV-1 and HSV-2 in vitro replication, with a potency comparable to that of the reference drug acyclovir.
View Article and Find Full Text PDFArch Dis Child
October 2021
Background: It has been speculated that the SARS-CoV-2 was already widespread in western countries before February 2020.
Methods: We gauged this hypothesis by analysing the nasal swab of infants with either bronchiolitis or a non-infectious disease admitted to the Ospedale Maggiore, Milan (one of the first epicentres of SARS-CoV-2 outbreak in Europe) from November 2019.
Results: The SARS-CoV-2 RNA was never detected in 218 infants with bronchiolitis (95 females, median age 4.
Persistent hypoxia is a main clinical feature of chronic wounds. Intriguingly, oxygen-loaded nanodroplets (OLNDs), filled with oxygen-solving 2H,3H-decafluoropentane and shelled with polysaccharides, have been proposed as a promising tool to counteract hypoxia by releasing a clinically relevant oxygen amount in a time-sustained manner. Here, four different types of chitosan (low or medium weight (LW or MW), glycol-(G-), and methylglycol-(MG-) chitosan) were compared as candidate biopolymers for shell manufacturing.
View Article and Find Full Text PDFBackground: There is limited knowledge on the origin and development from CD34 precursors of the ample spectrum of human natural killer (NK) cells, particularly of specialized NK subsets.
Objective: This study sought to characterize the NK-cell progeny of CD34DNAM-1CXCR4 and of other precursors circulating in the peripheral blood of patients with chronic viral infections (eg, HIV, hepatitis C virus, cytomegalovirus reactivation).
Methods: Highly purified precursors were obtained by flow cytometric sorting and cultured in standard NK-cell differentiation media (ie, SCF, FLT3, IL-7, IL-15).
Antimicrob Agents Chemother
September 2020
Posaconazole (PCZ) is a clinically approved drug used predominantly for prophylaxis and salvage therapy of fungal infections. Here, we report its previously undescribed anti-human cytomegalovirus (HCMV) activity. By using antiviral assays, we demonstrated that PCZ, along with other azolic antifungals, has a broad anti-HCMV activity, being active against different strains, including low-passage-number clinical isolates and strains resistant to viral DNA polymerase inhibitors.
View Article and Find Full Text PDFAll humans are colonized by a vast diversity of microbes (bacteria, archaea, protozoa, yeast, and fungi; collectively referred to as the microbiota) and viruses (the virobiota). This latter group includes viruses infecting prokaryotic cells (bacteriophages), viruses infecting eukaryotic-host cells, and virus-derived genetic elements present in host chromosomes. Although these eukaryotic viruses are mostly known to be pathogens, they are also able to establish mutualistic relationships with humans.
View Article and Find Full Text PDFThe influenza A virus (IAV) is a continuous health threat to humans as well as animals due to its recurring epidemics and pandemics. The IAV genome is segmented and the eight negative-sense viral RNAs (vRNAs) are transcribed into positive sense complementary RNAs (cRNAs) and viral messenger RNAs (mRNAs) inside infected host cells. A role for the secondary structure of IAV mRNAs has been hypothesized and debated for many years, but knowledge on the structure mRNAs adopt in vivo is currently missing.
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