Log10 TCID50 Research Articles

PSIV-6 Blood biomarkers of oxidative stress in offspring from dams infected with bovine viral diarrhea virus during late-term gestation

Abstract The objective of this experiment was to examine the impact of dams infected with bovine viral diarrhea virus (BVDV) during late gestation on inflammatory blood biomarkers in their offspring. Fetal infection with BVDV before d 125 to 150 of gestation results in the birth of immunotolerant, persistently infected (PI) calves. Infection of BVDV during late gestation results in transient fetal infections (TI). It was hypothesized that offspring of dams transiently infected with BVDV on d 175 of gestation would have greater inflammatory blood biomarkers than control offspring. Unvaccinated, yearling Hereford heifers (n = 24), seronegative for antibodies to BVDV1 and BVDV2 were bred by artificial insemination with X chromosome-bearing sperm from an Angus sire. On d 175 of pregnancy, heifers were intranasally inoculated with either Dulbecco’s Modified Eagle Medium + 2% horse serum (sham control) or 4.0 log TCID50 noncytopathic type 2 BVDV to generate control and transient infected calves, respectively. All BVDV-inoculated dams seroconverted by d 14 post-inoculation and all sham-inoculated control dams remained seronegative. Twelve, seronegative control heifer calves were born to the control dams, and 11 seropositive (to type 2 BVDV) TI heifer calves were born to BVDV-inoculated dams. All offspring were raised on pasture until weaning. At weaning, all calves were transported to our feedlot research facility, housed in one group feedlot pen, and transitioned to a high-energy concentrate-based diet until reaching an approximate body weight (BW) of 600 kg. Upon arrival, all animals received a standard heifer growth implant containing 200 mg of testosterone propionate and 20 mg of estradiol benzoate, a modified live viral vaccine containing IBR-BRSV-PI3, and were dewormed. Jugular blood samples were obtained every 28 d until harvest (280 d on feed) and analyzed for biomarkers of inflammation. Data were analyzed as a randomized block design with the MIXED procedures of SAS. There was a treatment x time interaction (P < 0.05) for plasma ceruloplasmin and the oxidized form of glutathione. On d 0 and 28 of the feeding period, all biomarkers were similar across treatments. By d 56 of the feeding period, ceruloplasmin (P < 0.03) and the oxidized form of glutathione (P < 0.01), indicators of chronic inflammation, were increased in plasma samples from TI heifers compared with controls. These parameters remained greater in TI heifers compared with controls throughout the feeding period. There were no treatment or treatment x time interactions for plasma interferon (INF)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and haptoglobin. These data suggest that TI heifers may be experiencing a greater level of oxidative stress later in the finishing period. This research was supported by USDA-NIFA Grant #2019-67015-29866.

PSIV-15 Effect of transient fetal bovine viral diarrhea virus infection on postnatal growth, estimated dry matter digestibility, glucose concentrations, and carcass characteristics

Abstract Fetal infection of bovine viral diarrhea virus (BVDV) before d 125 to 150 of gestation results in the birth of immunotolerant, persistently infected (PI) calves. Infection of BVDV during late gestation results in transient fetal infections (TI). Unvaccinated, yearling Hereford heifers (n = 25), seronegative for antibodies to BVDV1 and BVDV2, were bred by artificial insemination with X chromosome-bearing sperm from an Angus sire to examine the impact of TI on postnatal growth, estimated dry matter digestibility, blood glucose concentrations, and carcass characteristics. On d 175 of pregnancy, heifers were intranasally inoculated with either DMEM + 2% horse serum (sham control) to generate control calves or 4.0 log TCID50 noncytopathic type2 BVDV to generate TI calves. All sham-inoculated control dams remained seronegative, and all BVDV-inoculated dams seroconverted by d 14 post-inoculation. Sham-inoculated control dams (n = 12) and BVDV-inoculated dams (n = 12) gave birth to live calves. All control offspring were seronegative, and all TI offspring were seropositive for antibodies to type 2 BVDV at birth. All offspring were raised on pasture until weaning. At weaning, all calves were transported to our feedlot research facility, housed in one group feedlot pen, and transitioned to a high-energy concentrate-based diet until reaching an approximate BW of 600 kg. Upon arrival at the feedlot, all animals received a standard heifer growth implant, a modified live viral vaccine containing IBR-BRSV-PI3 and were dewormed. Heifer BW and jugular blood samples were collected every 28 d. On d 84 of the feeding period, titanium dioxide was added to the diet of 12, age-paired, individually fed, heifers (3 control and 3 TI heifers; approximately 1 yr of age) for 28 d and used to estimate dry matter digestibility. After approximately 280 d on feed heifers were transported to a USDA-inspected abattoir and harvested. The TI heifers had lighter birth weights (P < 0.03) and final BW (P < 0.04) when compared with control heifers. Average daily gain was greater (P < 0.01) in control compared with TI heifers. Blood glucose concentrations were similar between control and TI heifers at all sampling time points. Dry matter intake of individually fed heifers was similar across treatments. TI heifers had a 2.2% lesser (P < 0.05) dry matter digestibility and lighter (P < 0.01) hot carcass weights compared with controls. These data suggest that TI fetal BVDV infection negatively impacts growth throughout the feeding period, possibly by impacting gastrointestinal tract function. This research was supported by USDA-NIFA Grant # 2019-67015-29866.

Antiviral Effects of Ozonated Water for Handwashing Against SARS-CoV-2 Omicron Variant Using the E1052-20 Test Method of the American Society of Testing Materials International

ABSTRACT Alcohol-based hand rubs are generally recommended for infection control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hand hygiene agents, including ozonated water (OW), have been used as an alternative because alcohol-based products may cause skin damage. A few reports are available on the virucidal activity of OW against SARS-CoV-2; therefore, this study examined the inhibitory effect of 0.4, 1.0, and 4.0 ppm OW on the Omicron variant infection to VeroE6 cells expressing transmembrane protease serine 2 by calculating the median tissue culture infectious dose (TCID50) using the E1052–20 test method of the American Society of Testing Materials International. Additionally, viral RNA copies were measured in culture supernatants of control or OW. Each OW concentration demonstrated ≥5.6 log10 TCID50 reduction, corresponding to ≥99.999% reduction of infectious virus, while the control phosphate-buffered saline showed no inactivation effect. More than 5 log10 copies/mL reduction of viral RNA was observed in the culture supernatant of each OW compared with the control. These findings suggest that exposure of SARS-CoV-2 to at least 0.4 ppm OW for 5 s is sufficient for viral inactivation and that OW can be used as an alternative hand hygiene agent to prevent SARS-CoV-2 infection.

Persistence of two coronaviruses and efficacy of steam vapor disinfection on two types of carpet

BackgroundCoronaviruses, a group of highly transmissible and potentially pathogenic viruses, can be transmitted indirectly to humans via fomites. To date, no study has investigated their persistence on carpet fibers. Establishing persistence is essential before testing the efficacy of a disinfectant.MethodsThe persistence of BCoV and HCoV OC43 on polyethylene terephthalate (PET) and nylon carpet was first determined using infectivity and RT-qPCR assays. Then, the disinfectant efficacy of steam vapor was evaluated against both coronaviruses on nylon carpet.ResultsImmediately after inoculation of carpet coupons, 32.50% of BCoV and 3.87% of HCoV OC43 were recovered from PET carpet, compared to 34.86% of BCoV and 24.37% of HCoV OC43 recovered from nylon carpet. After incubation at room temperature for 1 h, BCoV and HCoV OC43 showed a 3.6 and > 2.8 log10 TCID50 reduction on PET carpet, and a 0.6 and 1.8 log10 TCID50 reduction on nylon carpet. Based on first-order decay kinetics, the whole gRNA of BCoV and HCoV OC43 were stable with k values of 1.19 and 0.67 h− 1 on PET carpet and 0.86 and 0.27 h− 1 on nylon carpet, respectively. A 15-s steam vapor treatment achieved a > 3.0 log10 TCID50 reduction of BCoV and > 3.2 log10 TCID50 reduction of HCoV OC43 on nylon carpet.ConclusionBCoV was more resistant to desiccation on both carpet types than HCoV OC43. Both viruses lost infectivity quicker on PET carpet than on nylon carpet. Steam vapor inactivated both coronaviruses on nylon carpet within 15 s.

Antiviral Activity of Graphene Oxide-Silver Nanocomposites Against Murine Betacoronavirus.

The high infectivity of coronaviruses has led to increased interest in developing new strategies to prevent virus spread. Silver nanoparticles (AgNPs) and graphene oxide (GO) have attracted much attention in the antiviral field. We investigated the potential antiviral activity of GO and AgNPs combined in the nanocomposite GO-Ag against murine betacoronavirus MHV using an in vitro model. GO, AgNPs, and GO-Ag characterization (size distribution, zeta potential, TEM visualization, FT-IR, and EDX analysis) and XTT assay were performed. The antiviral activity of GO-Ag nanocomposites was evaluated by RT-qPCR and TCID50 assays. The results were compared with free AgNPs and pure GO. Cell growth and morphology of MHV-infected hepatocytes treated with GO-Ag composites were analyzed by JuLI™Br. Immunofluorescence was used to visualize the cell receptor used by MHV. Ultrastructural SEM analysis was performed to examine cell morphology after MHV infection and GO-Ag composite treatment. A significant reduction in virus titer was observed for all nanocomposites tested, ranging from 3.2 to 7.3 log10 TCID50. The highest titer reduction was obtained for GO 5 µg/mL - Ag 25 µg/mL in the post-treatment method. These results were confirmed by RT-qPCR analysis. The results indicate that GO-Ag nanocomposites exhibited better antiviral activity compared to AgNPs and GO. Moreover, the attachment of AgNPs to the GO flake platform reduced their cytotoxicity. In addition, the GO-Ag composite modulates the distribution of the Ceacam1 cell receptor and can modulate cell morphology. Graphene oxide sheets act as a stabilizing agent, inhibiting the accumulation of AgNPs and reducing their cellular toxicity. The GO-Ag composite can physically bind and inhibit murine betacoronavirus from entering cells. Furthermore, the constant presence of GO-Ag can inhibit MHV replication and significantly limit its extracellular release. In conclusion, GO-Ag shows promise as an antiviral coating on solid surfaces to minimize virus transmission and spread.

Inactivation Validation of Ebola, Marburg, and Lassa Viruses in AVL and Ethanol-Treated Viral Cultures.

High-consequence pathogens such as the Ebola, Marburg, and Lassa viruses are handled in maximum-containment biosafety level 4 (BSL-4) laboratories. Genetic material is often isolated from such viruses and subsequently removed from BSL-4 laboratories for a multitude of downstream analyses using readily accessible technologies and equipment available at lower-biosafety level laboratories. However, it is essential to ensure that these materials are free of viable viruses before removal from BSL-4 laboratories to guarantee sample safety. This study details the in-house procedure used for validating the inactivation of Ebola, Marburg, and Lassa virus cultures after incubation with AVL lysis buffer (Qiagen) and ethanol. This study's findings show that no viable virus was detectable when high-titer cultures of Ebola, Marburg, and Lassa viruses were incubated with AVL lysis buffer for 10 min, followed by an equal volume of 95% ethanol for 3 min, using a method with a sensitivity of ≤0.8 log10 TCID50 as the limit of detection.

Development of a paper-based fluorescent carbon quantum dots MIPs sensor for selective detection of lumpy skin disease virus.

Lumpy skin disease (LSD) is a contagious viral disease caused by the Lumpy Skin Disease virus (LSDV), a member of the Capripoxviridae family. Traditional LSDV diagnostic procedures proved to have challenges in terms of cross reactivity as well as limited sensitivity and specificity. Herein, we combined molecularly imprinted polymers (MIPs) and quantum dots (QDs) technology to develop a paper-based turn on fluorescence sensor for rapid, sensitive and selective detection of LSDV. Under optimal conditions, the sensor showed linear enhancement in fluorescence intensity with the increase of LSDV concentration and exhibited a detection limit of 101 log10 TCID50 per ml. It also presented high specificity towards LSDV compared to other viruses viz sheep pox virus (SPV). Furthermore, the proposed sensor was successfully tested with spiked and real LSDV samples, proving its potential to serve as a sensitive selective sensor for LSDV diagnosis. Based on our knowledge, this is the first record of a paper-based diagnostic sensor for LSDV utilizing a CQDs-MIPs turn-on mechanism.

Phase II Trial of the Impact 0.5% Povidone-Iodine Nasal Spray (Nasodine®) on Shedding of SARS-CoV-2.

A Phase II trial was conducted to determine if nasal disinfection with a commercial Good Manufacturing Practice-manufactured 0.5% povidone-iodine nasal spray (Nasodine®) may be a useful adjunct in the management of COVID-19 by reducing viral shedding and prevention of transmission of SARS-CoV-2. The aim was to confirm the results from a human single-dose pilot study by assessing repeated and frequent doses on nasal shedding of SARS-CoV-2 from adult subjects with confirmed COVID-19. A multicenter, randomized, double-blinded, placebo-controlled Phase II clinical trial involving adults with early COVID-19 symptoms. Baseline nasal swabs were collected to quantify pretreatment SARS-CoV-2 nasal viral load, followed by Nasodine treatment eight times daily over 3 calendar days. Daily nasal swabs were collected post-dose to assess the impact of treatment on nasal viral load, measured by log10 TCID50 in quantitative culture. Nasodine subjects exhibited significantly improved reduction in viral load (log10 TCID50) on Days 2-4 compared to placebo recipients (p = 0.028), rate of nasal clearance of viable virus (p = 0.032), and complete (100%) nasal and throat clearance of the virus by Day 5. No difference was seen in antigen shedding as measured by time transition from Rapid Antigen Test (RAT) positivity to RAT negativity. A total of 20 doses of Nasodine® nasal spray administered over 2.5 days significantly reduced the titers of viable SARS-CoV-2 virus in the nasal passages of COVID-19 subjects. This is the first study demonstrating the efficacy of a tolerable intranasal formulation of povidone-iodine on viral shedding in COVID-19 subjects. Nasal disinfection may diminish viral transmission to others. 2 Laryngoscope, 134:3947-3952, 2024.

Titanium Dioxide Nanoparticles: A Novel Approach for Inhibiting Human Papillomavirus

Nanotechnology products such as titanium dioxide nanoparticles (TiO2-NPs) can be used for viral infections because of their unique characteristics. The current study aimed to determine the impact of TiO2-NPs on HPV type 1 and 2 infections. The characterization of these NPs was performed using dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD). The MTT assay was used to determine the toxic impacts of TiO2-NPs on BHK-21 cells. The efficiency of TiO2-NPs was performed using several parameters, including TCID50 and RT-PCR assays. An indirect immunofluorescence assay (IFA) was performed to estimate the inhibitory impact of TiO2-NPs on viral antigen expression, and Acyclovir was used as a reference medicine. When the human papilloma type 1 and 2 viruses exposed to TiO2-NPs at high doses (100 μg/mL) produced 0.3, 1.1, 2.3, and 3.3 log10 TCID50 decreases in infective virus load when compared with control viruses (P<0.0001), these TiO2-NPs doses were related to 24.9%, 35.1%, 47.2%, 59.5%, and 66.6% inhibition percentages that were determined depending on the viral titer as compared to virus control. It is concluded that TiO2-NPs have strong potential for the treatment of face and labial lesions caused by papillomaviruses 1 and 2 and could be used in topical formulations.

Attenuation of a Field Strain of Infectious Laryngotracheitis Virus in Primary Chicken Culture Cells and Adaptation to Secondary Chicken Embryo Fibroblasts

The establishment of commercial infectious laryngotracheitis virus (ILTV) live-modified vaccines has relied on serial passaging in chicken embryo (CEO) and tissue culture (TCO) for attenuation. The objective of this study was to attenuate and adapt a virulent CEO-related ILTV field strain (6340) in immortalized cells (LMH), primary chicken embryo kidney cells (CEK), chicken embryo liver cells (CEL), and chicken embryo fibroblasts (CEF). CEFs were refractory to parent ILTV, LMH cells produced low virus yields (~2.5 log10 TCID50 per mL), while CEK and CEL cells produced higher viral titers (≥log10 6.0 TCID50 per mL). After 52 passages in CELs, the cytopathic effect (CPE) was observed not only in hepatocytes but also in CEL fibroblasts. Once CPE was evident in CEL fibroblasts, 20 further passages in CEFs with viral titers reaching yields of ~4.4–5.5 log10 TCID50 per mL were performed. The attenuation of CEF-adapted viruses was evaluated after intra-tracheal and conjunctival inoculation in 28-day-old broilers by assessing clinical signs at five days post-inoculation (DPI). Virus CEL cells passages 80, 90, and 100, and CEF passages 10 and 20 were significantly attenuated compared to the parental strain. This is the first report of the attenuation of a virulent field CEO-related ILTV strain (RFLP Group V) in CEF cells—a cell type from a different embryonic germ layer (mesoderm) than ILTV target cells—the respiratory epithelium (endoderm). This finding underscores the potential use of CEF adaptation for the development of a live-attenuated ILTV vaccine.

Small Molecules Targeting 3C Protease Inhibit FMDV Replication and Exhibit Virucidal Effect in Cell-Based Assays.

Foot-and-mouth disease (FMD) is a highly contagious disease in cloven-hoofed animals, caused by the foot-and-mouth disease virus (FMDV). It is endemic in Asia and Africa but spreads sporadically throughout the world, resulting in significant losses in the livestock industry. Effective anti-FMDV therapeutics could be a supportive control strategy. Herein, we utilized computer-aided, structure-based virtual screening to filter lead compounds from the National Cancer Institute (NCI) diversity and mechanical libraries using FMDV 3C protease (3Cpro) as the target. Seven hit compounds were further examined via cell-based antiviral and intracellular protease assays, in which two compounds (NSC116640 and NSC332670) strongly inhibited FMDV, with EC50 values at the micromolar level of 2.88 µM (SI = 73.15) and 5.92 µM (SI = 11.11), respectively. These compounds could inactivate extracellular virus directly in a virucidal assay by reducing 1.00 to 2.27 log TCID50 of the viral titers in 0-60 min. In addition, the time-of-addition assay revealed that NSC116640 inhibited FMDV at the early stage of infection (0-8 h), while NSC332670 diminished virus titers when added simultaneously at infection (0 h). Both compounds showed good FMDV 3Cpro inhibition with IC50 values of 10.85 µM (NSC116640) and 4.21 µM (NSC332670). The molecular docking of the compounds on FMDV 3Cpro showed their specific interactions with amino acids in the catalytic triad of FMDV 3Cpro. Both preferentially reacted with enzymes and proteases in physicochemical and ADME analysis studies. The results revealed two novel small molecules with antiviral activities against FMDV and probably related picornaviruses.

Cell culture adaptation of Avipox viruses isolated from different species of birds

Avianpox (AP) is an infectious, slow spreading viral disease that has been reported to affect numerous species of birds including poultry. There is very limited information available regarding the molecular and biological characteristics of the avipox viruses (APVs) circulating in India. In the present study, APVs from fowl [FP/As- K(R)], pigeon [P2/ As- K9(R)] and duck [D2/ As- N] origin isolated from natural outbreaks of the disease in different areas of Assam were selected for adaptation in different cell culture. All the three isolates were propagated in chicken embryo fibroblast (CEF) primary cell culture and Vero cell line and their propagation was confirmed by observing virus specific cytopathic effects (CPE) and by performing PCR targeting the 4b gene of APV. All three isolates were adapted in the CEF primary culture with production of virus specific CPE. However, a high degree of CPE was observed in the cultures infected with the fowl isolate from an earlier passage (P-11) in comparison to the other two isolates. Even the time required for completion of CPE was considerably less in case of the fowl isolate. The log TCID50 of the fowl isolate was found to be 4.18 ± 0.11, 5.29 ± 0.06 and 6.29 ± 0.13, respectively in the 5th, 15th and 20th passage, which was higher in comparison to the other two isolates. Interestingly, none of the isolates showed any virus specific CPE in vero cell line on propagation till the 10th passage. Moreover, all the passages were found to be negative by PCR.

Disinfection of influenza a viruses by Hypocrellin a-mediated photodynamic inactivation

BackgroundInfluenza A viruses can be transmitted indirectly by surviving on the surface of an object. Photodynamic inactivation (PDI) is a promising approach for disinfection of pathogens. MethodsPDI was generated using Hypocrellin A (HA) and red light emitting diode (625–635 nm, 280 W/m2). Effects of the HA-mediated PDI on influenza viruses H1N1 and H3N2 were evaluated by the reduction of viral titers compared to virus control. After selection of the HA concentrations and illumination times, the applicability of PDI was assessed on surgical masks. Reactive oxygen species (ROS) were determined using a 2′-7′-dichlorodihydrofluorescein diacetate fluorescence probe. ResultsIn solution, 10 μM HA inactivated up to 5.11 ± 0.19 log10 TCID50 of H1N1 and 4.89 ± 0.38 log10 TCID50 of H3N2 by illumination for 5 and 30 min, respectively. When surgical masks were contaminated by virus before HA addition, PDI inactivated 99.99% (4.33 ± 0.34 log reduction) of H1N1 and 99.40% (2.22 ± 0.39 log reduction) of H3N2 under the selected condition. When the masks were pretreated with HA before virus addition, PDI decontaminated 99.92% (3.11 ± 0.19 log reduction) of H1N1 and 98.71% (1.89 ± 0.20 log reduction) of H3N2 virus. The fluorescence intensity of 2′,7′-dichlorofluorescein in photoactivated HA was significantly higher than the cell control (P > 0.05), indicating that HA efficiently generated ROS. ConclusionsHA-mediated PDI is effective for the disinfection of influenza viruses H1N1 and H3N2. The approach could be an alternative to decontaminating influenza A viruses on the surfaces of objects.

Photodynamic Treatment of Titanium Dioxide Nanoparticles is a Convenient Method of Adenoviral Inactivation

Today, the search for safe ways to inactivate pathogens is becoming especially relevant in connection with the coronavirus pandemic. Standard methods using chlorides and ultraviolet irradiation have disadvantages related to toxicity and low efficiency. Photodynamic inactivation involving nanoparticles is already used to disinfect water and air from microorganisms and enveloped viruses such as human herpes simplex virus, vesicular stomatitis virus, human immunodeficiency virus, and hepatitis B and C viruses. The aim of this work was to evaluate the possibility of the inactivation of human adenovirus type 5 in an organic medium using titanium dioxide irradiated with ultraviolet light. Methods. The nanosized titanium dioxide material was obtained by the thermal decomposition of a suspension of hydrated titanium dioxide TiO(OH)2 (metatitanic acid). The analysis of the morphology of the TiO2 nanopowder was carried out using electron scanning microscopy (SEM), which showed that TiO2 nanopowder contains soft aggregates of nanoparticles mostly 20‒30 nm in size. Cytotoxicity, virulicidal and antiviral action of titanium dioxide were determined by standard methods using (3-(4,5-dimathylthiazol-2-yl)-2,5-dipheniltetrazolium bromide (MTT). The titanium dioxide suspension was irradiated at a distance of 20 cm from 1 to 30 min with a bactericidal UV lamp (OBB15P, BactoSfera, Poland (254 nm)). The concentration of nanoparticles for irradiation was 1.0 mg/mL. Adenovirus suspension with titer 6.0 log10 TCID50 /mL was added to the nanoparticles immediately after irradiation. The titer of virus synthesized in the presence of titanium dioxide was determined by the end of the virus dilution, which causes 50% of the cytopathic effect of the virus on cells. All studies were performed in three replicates; the number of parallel determinations was three. Results. A dose-dependent effect of titanium dioxide nanoparticles on the viability of Hep-2 cells was revealed. At the NPs concentration of 1 mg/mL, quite a low cell viability was observed (32—39%), with a decrease in concentration to 0.1 and 0.01 mg/mL, the NPs were less toxic (cell viability was in the range of 62—90%). The TiO2 NPs dissolved in glycerin-water had no virulicidal effect, as the virus titer was similar to the control values. Instead, NPs dissolved in propanediol-ethanol reduced the infectious titer of the virus by 6.0 log10, which indicates their high virulicidal effect. The absence of an antiviral effect was shown when NPs were added to infected cells. A decrease in the virus titer by 4.5‒5.0 log10 was recorded uponitsinteracting with irradiated NPs for 1‒30 min. The effect persisted for 3 h after exposure to NPs. Conclusions. The cytotoxic, virulicidal, and antiviral effects of optically active TiO2 nanoparticles were determined in optimal conditions. Regardless of the solvent, NPs had low toxicity at a concentration of 0.1 mg/mL. The TiO2 NPs dissolved in glycerin-water had no virulicidal effect; but dissolved in propanediol-ethanol reduced the infectious titer of the virus by 6.0 log10, which indicates its high virulicidal effect. NPs in a propanediol-ethanol solution, irradiated with UV for 1‒30 min, completely inhibited adenovirus reproduction. NPs in a glycine-water solution reduced the virus titer by 0.5 log10. The control with NPs without irradiation slightly reduced the virus titer (by 0.45 log10). The ability of NPs to completely inactivate adenovirus was maintained for 3 h. It was shown for the first time that the non-enveloped HAdV5 virus could be efficiently inactivated by UV-induced TiO2 photocatalysis.

Comparative Virucidal Activities of Essential Oils and Alcohol-Based Solutions against Enveloped Virus Surrogates: In Vitro and In Silico Analyses.

The large-scale use of alcohol (OH)-based disinfectants to control pathogenic viruses is of great concern because of their side effects on humans and harmful impact on the environment. There is an urgent need to develop safe and environmentally friendly disinfectants. Essential oils (EOs) are generally recognized as safe (GRAS) by the FDA, and many exhibit strong antiviral efficacy against pathogenic human enveloped viruses. The present study investigated the virucidal disinfectant activity of solutions containing EO and OH against DENV-2 and CHIKV, which were used as surrogate viruses for human pathogenic enveloped viruses. The quantitative suspension test was used. A solution containing 12% EO + 10% OH reduced > 4.0 log10 TCID50 (100% reduction) of both viruses within 1 min of exposure. In addition, solutions containing 12% EO and 3% EO without OH reduced > 4.0 log10 TCID50 of both viruses after 10 min and 30 min of exposure, respectively. The binding affinities of 42 EO compounds and viral envelope proteins were investigated through docking analyses. Sesquiterpene showed the highest binding affinities (from -6.7 to -8.0 kcal/mol) with DENV-2 E and CHIKV E1-E2-E3 proteins. The data provide a first step toward defining the potential of EOs as disinfectants.

Antiviral activity of biosynthesized copper nanoparticle by Juglans regia green husk aqueous extract and Iron nanoparticle: molecular docking and in-vitro studies.

The interaction between nanoparticles (NPs) and viruses is attracting interest because of the antiviral potential of NPs. This study aims to investigate the antiviral potential of NPs against Herpes simplex virus types 1 (HSV-1). Molecular docking studies were conducted by Molegro virtual docker software. An extract of Juglans regia green husk was utilized to biosynthesize copper-oxide nanoparticles (CuNPs). The cytotoxicity of NPs was evaluated by MTT assay. Different treatment assays were conducted. Another assay was designed to employ the concentration of 300 μg/ml of CuNPs, which is the highest concentration that did not precipitate. Finally, chemically synthesized Iron oxide nanoparticles (FeNPs) were utilized to adsorb CuNPs. The antiviral effect of FeNPs was investigated, separately. Docking results confirmed that NPs could interact with the HSV-1 glycoproteins and prevent viral entry. MTT assay results illustrated that the minimum non-toxic concentration (MNTD) of CuNPs is 100 μg/ml which did not exhibit antiviral properties. Employing a noncytotoxic concentration of FeNPs (300 mg/ml) in combination with cytotoxic concentration of CuNPs (300 μg / ml), eliminated the cytotoxicity effects of CuNPs. Exposure of the virus with the combination of CuNPs and FeNPs resulted in 4.5 log10 TCID50 reductions in HSV-1. While treating HSV-1 with only FeNPs reduced the titer of virus by 3.25 log10 TCID50. The results highlight that combination of CuNPs and FeNPs have antiviral activity against HSV-1. Moreover, FeNPs demonstrated antiviral properties against HSV-1 separately.

Investigation of the Inhibition Activity of Aluminium Oxide Nanoparticles for Herpes Simplex Type 1.

Several studies have shown that Herpes simplex type 1 )HSV-1 (is one of the viruses resistant to medications, so potential antiherpetic agents need to be evaluated. This study aimed to evaluate the impact of Aluminum Oxide Nanoparticles (Al2O3-NPs) on HSV-1 infection. Characterization of Al2O3-NPs was performed using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), dynamic light scattering (DLS), and high-resolution transmission electron microscopy (HRTEM). The MTT test was used to investigate the toxicity action of Al2O3-NPs on viable cells. Quantitative Real-Time PCR (qRT-PCR)and TCID50 assays were used to achieve the antiherpetic performance Al2O3-NPs.Indirect immunofluorescence assay (IFA) was performed to determine the inhibitory impact of Al2O3-NPs on viral antigen expression, and acyclovir was utilized as a standard agent in all tests. HSV-1 subjected to Al2O3-NPs at the maximum non-toxic concentration (100 μg / mL) leads to a decrease of 0.1, 0.7, 1.8, and 2.5 log10 TCID50 in the infectious titer relative to virus control (P<0.0001). This concentration of Al2O3-NPs was correlated with 16.9%, 47.1 %, 61.2 %, 72.5 % and 74.6 % inhibition rates, calculated based on HSV-1 viral load compared to virus control. Our results have shown that Al2O3-NPs have a robust antiviral activity against HSV-1. This function demonstrates excellent potential for using Al2O3-NP in topical formulations for treating orolabial or genital herpetic lesions.

A Novel Application of Zinc Oxide Nanoparticles for Inhibition of Molluscum contagiosum Virus Infection.

Molluscum contagiosum virus (MCV) is an infection caused by the molluscum contagiosum virus. Antiviral medications used to treat MCV infections have several problems, including drug-resistant and toxicity. As a result, improving safe, innovative, and effective antiviral drugs is critical. Therefore the current study aimed to investigate ZnO-NPs effects on M. contagisum infection and molluscum contagiosum virus replication, among the main exciting viruses that menace human health. The antiviral activity of zinc oxide nanoparticles (ZnO-NPs) against MCV infection was investigated in this work. FESEM and TEM electron microscopy were used to examine the nanoparticles. The cytotoxicity of the nanoparticles was assessed using the MTT assay, and anti-influenza effects were detected using RT-PCR and TCID50. An indirect immunofluorescence experiment was used to investigate the inhibitory effect of nanoparticles on viral antigen expression. In all tests, acyclovir was employed as a control. Compared to virus control, post-exposure of MCV with ZnO nanoparticles at the highest dose but is not toxic (100 g/mL) resulted in 0.2, 0.9, 1.9, and 2.8 log10 TCID50 reductions in infectious diseases virus titer (P=0.0001). This ZnO-nanoparticles level was accompanied by an inhibition percentage (17.8%, 27.3%, 53.3%, 62.5 %, and 75.9%), respectively, measured based on viral load compared with the virus control. Compared to the positive control, fluorescence emission intensity in virally infected cells that administrated ZnO nanoparticles was statically decreased. Our findings demonstrated that ZnO-NPs have antiviral effects against the MCV. This property indicates that ZnO-NP has a high potential for usage in topical formulations to treat facial and labial lesions.

Infectivity and transmissibility of an avian H3N1 influenza virus in pigs

In 2019 a low pathogenic H3N1 avian influenza virus (AIV) caused an outbreak in Belgian poultry farms, characterized by an unusually high mortality in chickens. Influenza A viruses of the H1 and H3 subtype can infect pigs and become established in swine populations. Therefore, the H3N1 epizootic raised concern about AIV transmission to pigs and from pigs to humans. Here, we assessed the replication efficiency of this virus in explants of the porcine respiratory tract and in pigs, using virus titration and/or RT-qPCR. We also examined transmission from directly, intranasally inoculated pigs to contact pigs. The H3N1 AIV replicated to moderate titers in explants of the bronchioles and lungs, but not in the nasal mucosa or trachea. In the pig infection study, infectious virus was only detected in a few lung samples collected between 1 and 3 days post-inoculation. Virus titers were between 1.7 and 4.8 log10 TCID50. In line with the ex vivo experiment, no virus was isolated from the upper respiratory tract of pigs. In the transmission experiment, we could not detect virus transmission from directly inoculated to contact pigs. An increase in serum antibody titers was observed only in the inoculated pigs. We conclude that the porcine respiratory tract tissue explants can be a useful tool to assess the replication efficiency of AIVs in pigs. The H3N1 AIV examined here is unlikely to pose a risk to swine populations. However, continuous risk assessment studies of emerging AIVs in pigs are necessary, since different virus strains will have different genotypic and phenotypic traits.

Berbamine Hydrochloride Inhibits African Swine Fever Virus Infection In Vitro

African swine fever virus (ASFV) causes a viral disease in swine with a mortality rate of approximately 100%, threatening the global pig industry's economic development. However, vaccines are not yet commercially available, and other antiviral therapeutics, such as antiviral drugs, are urgently needed. In this study, berbamine hydrochloride, a natural bis-benzylisoquinoline alkaloid isolated from the traditional Chinese herb Berberis amurensis, showed significant antiviral activity against ASFV. The 50% cytotoxic concentration (CC50) of berbamine hydrochloride in porcine alveolar macrophages (PAMs) was 27.89 μM. The antiviral activity assay demonstrated that berbamine hydrochloride inhibits ASFV in a dose-dependent manner. In addition, a 4.14 log TCID50 decrease in the viral titre resulting from non-cytotoxic berbamine hydrochloride was found. Moreover, the antiviral activity of berbamine hydrochloride was maintained for 48h and took effect at multiplicities of infection (MOI) of 0.01, 0.1, and 1. The time-of-addition analysis revealed an inhibitory effect throughout the entire virus life-cycle. A subsequent viral entry assay verified that berbamine hydrochloride blocks the early stage of ASFV infection. Moreover, similar anti-ASFV activity of berbamine hydrochloride was also found in PK-15 and 3D4/21 cells. In summary, these results indicate that berbamine hydrochloride is an effective anti-ASFV natural product and may be considered a novel antiviral drug.