Search Results (37)

This study explored the distribution and genetic characteristics of respiratory pathogens in outpatients with acute respiratory infections (ARIs) in Yangon, Myanmar, during the 2023 rainy season. Among 267 patients who tested negative for influenza, RSV, and SARS-CoV-2 using rapid diagnostic tests, 84.6% were positive for at least one pathogen according to a multiplex polymerase chain reaction (PCR) assay, the BioFire^® FilmArray^® Respiratory Panel 2.1. The most common viruses detected were rhinovirus/enterovirus (RV/EV) at 37.8%, respiratory syncytial virus (RSV) at 22.4%, and human metapneumovirus (hMPV) at 10.0%. These pathogens co-circulated mainly from July to September, with RV/EV consistently predominant. Symptom comparison among RV/EV-, RSV-, and hMPV-infected patients showed similar clinical features, though fever was more common in hMPV cases. Among RV/EV-positive patients, 59.3% had single infections, while 40.7% experienced co-infections, especially with RSV and adenovirus. Genotyping identified 28 types from five species, primarily RV-A and RV-C, which were genetically diverse. One EV-D68 case was also found, emphasizing its potential risk. This study underscores the genetic diversity and clinical impact of RV/EV and stresses the importance of ongoing molecular surveillance in Myanmar’s post-COVID-19 context to inform effective public health responses. Full article

Respiratory viruses continue to present serious health challenges to human wellness. Growing evidence suggests that the more severe and damaging effects and symptoms of influenza, rhinovirus (RV), respiratory syncytial virus (RSV), and COVID-19 may primarily result from their common ability to disorganize the body’s healthy immune response. The simultaneous over-stimulation of several reactive oxygen species (ROS) pathways and concurrent suppression of bioavailable Nitic Oxide (NO) contribute to an immune disbalance that can lead to cellular oxidative distress and an excessive inflammatory response. This study evaluated the real-time, acute ability of a single, orally administered 50 mg encapsulated dose of a plant-based dietary supplement (“PB-Blend”), compared to 1000 mg of Vitamin C as a positive control, to modulate multiple ROS associated with a dampened immune response, as well as NO and other markers of inflammation, in a cohort recovering from a moderate course of COVID-19. This randomized, double-blind study was performed on 28 individuals 18–24 days after a moderate COVID-19 infection. Participants were orally supplemented with a single encapsulated dose of either 50 mg of PB-Blend or 1000 mg Vitamin C as a positive control. Changes in the levels of bioavailable NO (measured as circulating NOHb) were assessed, as well as the ex vivo cellular formation of mitochondrial, NOX2-, iNOS-, and TNFα-dependent ROS. All parameters were measured in real time before ingestion (baseline), and then at 30, 60, 120, and 180 min after administration. ROS were measured using a portable electron paramagnetic resonance (EPR) spectrometer. Inflammatory, immunity (hsCRP and TNFα plasma levels), interleukin (IL1, IL6, IL8, and IL10), cytokine (IFNγ, TNFα, and NF-κB), and immunoglobulin (IgA, IgM, IgG, and IgE) profiles were also followed. In addition to laboratory and cell function investigations, we performed clinical cardio ergometry, blood O₂ saturation, and respirometry examinations. As hypothesized, the collected baseline data from this study group confirmed that mitochondrial, NOX2, and iNOS enzymatic systems were strongly involved in the generation of ROS at 18–24 days following a positive COVID-19 PCR test. Acute single-dose supplementation of 50 mg PB-Blend had a multifunctional impact on ROS and significantly inhibited the following: (a.) mitochondrial ROS levels by up to 56%; (b.) iNOS by up to 60%; and (c.) NOX2-dependent ROS generation by up to 49%. Moreover, 1000 mg Vitamin C supplementation exhibited narrower ROS-mitigating activity by solely inhibiting NOX2-dependent ROS generation by 45%. Circulating NOHb levels were significantly increased after PB-Blend administration (33%), but not after Vitamin C administration. PB-Blend and Vitamin C exhibited similar potential to reduce ex vivo high dose TNFα (200 ng/mL)-induced H₂O₂ formation. These results suggest that 50 mg of PB-Blend has the potential to modulate disbalanced mitochondria, iNOS, and NOX2 enzymatic systems that can be engendered during respiratory viral infection and subsequent recovery. Moreover, PB-Blend, but not Vitamin C, showed potential to upregulate bioavailable NO, which is known to decline under these conditions. Based upon these observations, PB-Blend could be considered an alternative to, or to be used in tandem with Vitamin C in applications that promote immune support and recovery during seasons of heightened respiratory viral risk (e.g., “flu season”). Full article

Objectives: We aimed to analyze the landscape of viral respiratory illnesses (VRIs) in a large metropolitan area in Southern California with a focus on the COVID-19 pandemic. Methods: We conducted a retrospective cohort study within the UCLA Health System, which evaluated children aged 0–5 years who received comprehensive respiratory viral panel (cRVP) testing during August–February of 2018–2023. The patient demographics, disease severity, and clinical course were specifically compared during the pandemic. Predictors of significant VRI were determined by multivariate logistic regression. Results: A total of 1321 children underwent cRVP testing, and 753 positive subjects were identified during the study period. Rhinovirus (RV) was by far the most frequent virus detected across 5 years, even during the COVID-19 pandemic, followed by respiratory syncytial virus (RSV). Along with RSV and human metapneumovirus, RV was identified as an independent risk for significant disease and occurred irrespective of co-infection with other viruses. Conclusions: RV was the most common viral pathogen in young children, even during the height of the COVID-19 pandemic, and was an independent driver of moderate-to-severe disease, particularly in children with comorbidities. Ethnic disparities were also observed as a risk for significant disease, underscoring the need for targeted interventions and heightened clinical vigilance in pediatric populations. Full article

Rhinoviruses and respiratory enteroviruses remain among the leading causes of acute respiratory infections, particularly in children. Little is known about the genetic diversity of enteroviruses and rhinoviruses in pediatric patients with acute respiratory infections in Russia. We assessed the prevalence of human rhinoviruses/enteroviruses (HRV/EV) in 1992 children aged 0 to 17 years hospitalized with acute respiratory infections during the 2023–2024 epidemic season using PCR. The detection rate of HRV/EV was 11% (220/1992). We performed typing of 58 HRV and 28 EV viruses by partial sequencing of the VP1 gene. Rhinovirus A was the most common among HRV, followed by rhinovirus C; rhinovirus B was detected in only three cases. Enteroviruses were represented by all four species, with the EV-D68 genotype being the most frequently detected. Phylogenetic analysis of the VP1 fragment of EV-D68 showed that all our sequences belonged to the B3 subclade. We identified the first case of EV-C105 infection in Russia in a two-year-old girl hospitalized with pneumonia. Phylogenetically, the Novosibirsk strain EV-C105 was closely related to a strain discovered in France in 2018. This research helped to fill a critical gap in understanding the epidemiological landscape of HRV/EV in pediatric populations within Russia. Full article

Rhinovirus C (RV-C) infection can trigger asthma exacerbations in children and adults, and RV-C-induced wheezing illnesses in preschool children correlate with the development of childhood asthma. Surfactant protein A (SP-A) plays a critical role in regulating pulmonary innate immunity by binding to numerous respiratory pathogens. Mature SP-A consists of multiple isoforms that form the hetero-oligomers of SP-A1 and SP-A2, organized in 18-mers. In this report, we examined the efficacy of SP-A to antagonize RV-C infection using the wild-type (RV-C15) and reporter-expressing (RV-C15-GFP) viruses in differentiated nasal epithelial cells (NECs) from asthmatic and non-asthmatic children. We also determined the antiviral mechanism of action of SP-A on RV-C15 infection. The native SP-A was purified from alveolar proteinosis patients. The recombinant (r) SP-A1 and SP-A2 variants were expressed in FreeStyle™ 293-F cells. SP-A reduced the fluorescent focus-forming units (FFUs) after RV-C15-GFP infection of NECs by 99%. Both simultaneous and 4 h post-infection treatment with SP-A inhibited RV-C15 and RV-C15-GFP viral RNA load by 97%. In addition, the antiviral genes and chemokines (IFN-λ, IRF-7, MDA-5, and CXLC11) were not induced in the infected NECs due to the inhibition of RV-C propagation by SP-A. Furthermore, SP-A bound strongly to RV-C15 in a dose- and Ca²⁺-dependent manner, and this interaction inhibited RV-C15 binding to NECs. In contrast, rSP-A1 did not bind to solid-phase RV-C15, whereas the rSP-A2 variants, [A₉₁, K₂₂₃] and [P₉₁, Q₂₂₃], had strong binding affinities to RV-C15, similar to native SP-A. This study demonstrates that SP-A might have potential as an antiviral for RV infection and RV-induced asthma exacerbations. Full article

Enteroviruses have been a historical concern since the identification of polioviruses in humans. Wild polioviruses have almost been eliminated, while multiple species of non-polio enteroviruses and their variants co-circulate annually. To date, at least 116 types have been found in humans and are grouped into the species Enterovirus A–D and Rhinovirus A–C. However, there are few available antiviral drugs, especially with a universal pharmaceutical effect. Here, we demonstrate that peptide P25 from EV-D68 has broad antiviral activity against EV A–D enteroviruses in vitro. P25, derived from the HI loop and β-I sheet of VP1, operates through a conserved hydrophilic motif -R---K-K--K- and the hydrophobic F near the N-terminus. It could prevent viral infection of EV-A71 by competing for the heparan sulfate (HS) receptor, binding and stabilizing virions by suppressing the release of the viral genome. P25 also inhibited the generation of infectious viral particles by reducing viral protein synthesis. The molecular docking revealed that P25 might bind to the pocket opening area, a potential target for broad-spectrum antivirals. Our findings implicate the multiple antiviral effects of peptide P25, including blocking viral binding to the HS receptor, impeding viral genome release, and reducing progeny particles, which could be a novel universal anti-enterovirus drug candidate. Full article

Rhinovirus C (RV-C) infects airway epithelial cells and is an important cause of acute respiratory disease in humans. To interrogate the mechanisms of RV-C-mediated disease, animal models are essential. Towards this, RV-C infection was recently reported in wild-type (WT) mice, yet, titers were not sustained. Therefore, the requirements for RV-C infection in mice remain unclear. Notably, prior work has implicated human cadherin-related family member 3 (CDHR3) and stimulator of interferon genes (STING) as essential host factors for virus uptake and replication, respectively. Here, we report that even though human (h) and murine (m) CDHR3 orthologs have similar tissue distribution, amino acid sequence homology is limited. Further, while RV-C can replicate in mouse lung epithelial type 1 (LET1) cells and produce infectious virus, we observed a significant increase in the frequency and intensity of dsRNA-positive cells following hSTING expression. Based on these findings, we sought to assess the impact of hCDHR3 and hSTING on RV-C infection in mice in vivo. Thus, we developed hCDHR3 transgenic mice, and utilized adeno-associated virus (AAV) to deliver hSTING to the murine airways. Subsequent challenge of these mice with RV-C15 revealed significantly higher titers 24 h post-infection in mice expressing both hCDHR3 and hSTING—compared to either WT mice, or mice with hCDHR3 or hSTING alone, indicating more efficient infection. Ultimately, this mouse model can be further engineered to establish a robust in vivo model, recapitulating viral dynamics and disease. Full article

Enterovirus genomic replication initiates at a predicted RNA cloverleaf (5′CL) at the 5′ end of the RNA genome. The 5′CL contains one stem (SA) and three stem-loops (SLB, SLC, SLD). Here, we present an analysis of 5′CL conservation and divergence for 209 human health-related serotypes from the enterovirus genus, including enterovirus and rhinovirus species. Phylogenetic analysis indicates six distinct 5′CL serotypes that only partially correlate with the species definition. Additional findings include that 5′CL sequence conservation is higher between the EV species than between the RV species, the 5′CL of EVA and EVB are nearly identical, and RVC has the lowest 5′CL conservation. Regions of high conservation throughout all species include SA and the loop and nearby bases of SLB, which is consistent with known protein interactions at these sites. In addition to the known protein binding site for the Poly-C binding protein in the loop of SLB, other conserved consecutive cytosines in the stems of SLB and SLC provide additional potential interaction sites that have not yet been explored. Other sites of conservation, including the predicted bulge of SLD and other conserved stem, loop, and junction regions, are more difficult to explain and suggest additional interactions or structural requirements that are not yet fully understood. This more intricate understanding of sequence and structure conservation and variability in the 5′CL may assist in the development of broad-spectrum antivirals against a wide range of enteroviruses, while better defining the range of virus isotypes expected to be affected by a particular antiviral. Full article

The open-source drug library, namely, MMV Pandemic Response Box, contains 153 antiviral agents, a chemically and pharmacologically diverse mixture of early-stage, emerging anti-infective scaffolds, and mature compounds currently undergoing clinical development. Hence, the Pandemic Response Box might contain compounds that bind and interfere with target molecules or cellular pathways that are conserved or shared among the closely related viruses with enterovirus A71 (EV-A71). This study aimed to screen antiviral agents included in the Pandemic Response Box for repurposing to anti-EV-A71 activity and investigate the inhibitory effects of the compounds on viral replication. The compounds’ cytotoxicity and ability to rescue infected cells were determined by % cell survival using an SRB assay. The hit compounds were verified for anti-EV-A71 activity by virus reduction assays for viral RNA copy numbers, viral protein synthesis, and mature particle production using qRT-PCR, Western blot analysis, and CCID₅₀ assay, respectively. It was found that some of the hit compounds could reduce EV-A71 genome replication and protein synthesis. D-D7 (2-pyridone-containing human rhinovirus 3C protease inhibitor) exhibited the highest anti-EV-A71 activity. Even though D-D7 has been originally indicated as a polyprotein processing inhibitor of human rhinovirus 3C protease, it could be repurposed as an anti-EV-A71 agent. Full article

This study aims to analyze the epidemiological and pathogenic characteristics of an outbreak primarily caused by respiratory syncytial virus (RSV), human rhinovirus (HRV), and human metapneumovirus (HMPV) in a kindergarten and primary school. The outbreak was investigated by field epidemiological investigation, and the common respiratory pathogens were screened by RT-PCR detection technology. The attack rate of this outbreak was 63.95% (110/172). Main symptoms included cough (85.45%), sore throat (60.91%), and sneezing (60.00%). Multifactorial logistic regression analysis revealed that continuous handwashing and mouth and nose covering when sneezing were protective factors. All 15 collected throat swab specimens tested positive for viruses, with HMPV as the predominant pathogen (80.00%), followed by HRV (53.33%), and two cases of positive respiratory syncytial virus (13.33%). Among them, six samples showed coinfections of HMPV and HRV, and one had coinfections of HMPV and RSV, resulting in a coinfection rate of 46.67%. Genetic sequencing indicated that the HMPV genotype in this outbreak was A2c, and the HRV genotype was type A, resulting in a coinfection outbreak of HMPV, HRV, and RSV in schools and kindergartens, suggesting that multi-pathogen surveillance of respiratory tract infections should be strengthened. Full article

The human adenovirus (HAdV) is a common pathogen in children that can cause acute respiratory virus infection (ARVI). However, the molecular epidemiological and clinical information relating to HAdV among hospitalized children with ARVI is rarely reported in Russia. A 4-year longitudinal (2019–2022) study among hospitalized children (0–17 years old) with ARVI in Novosibirsk, Russia, was conducted to evaluate the epidemiological and molecular characteristics of HAdV. Statistically significant differences in the detection rates of epidemiological and virological data of all positive viral detections of HAdV were analyzed using a two-tailed Chi-square test. The incidence of HAdV and other respiratory viruses such as human influenza A and B viruses, respiratory syncytial virus, coronavirus, parainfluenza virus, metapneumovirus, rhinovirus, bocavirus, and SARS-CoV-2 was investigated among 3190 hospitalized children using real-time polymerase chain reaction. At least one of these respiratory viruses was detected in 74.4% of hospitalized cases, among which HAdV accounted for 4%. A total of 1.3% co-infections with HAdV were also registered. We obtained full-genome sequences of 12 HAdVs, which were isolated in cell cultures. Genetic analysis revealed the circulation of adenovirus of genotypes C1, C2, C5, C89, and 108 among hospitalized children in the period from 2019–2022. Full article

The human rhinovirus (RV) is a positive-stranded RNA virus that causes respiratory tract diseases affecting both the upper and lower halves of the respiratory system. RV enhances its replication by concentrating RNA synthesis within a modified host membrane in an intracellular compartment. RV infections often occur alongside infections caused by other respiratory viruses, and the RV virus may remain asymptomatic for extended periods. Alongside qualitative detection, it is essential to accurately quantify RV RNA from clinical samples to explore the relationships between RV viral load, infections caused by the virus, and the resulting symptoms observed in patients. A reference material (RM) is required for quality evaluation, the performance evaluation of molecular diagnostic products, and evaluation of antiviral agents in the laboratory. The preparation process for the RM involves creating an RV RNA mixture by combining RV viral RNA with RNA storage solution and matrix. The resulting RV RNA mixture is scaled up to a volume of 25 mL, then dispensed at 100 µL per vial and stored at −80 °C. The process of measuring the stability and homogeneity of RV RMs was conducted by employing reverse transcription droplet digital polymerase chain reaction (RT-ddPCR). Digital PCR is useful for the analysis of standards and can help to improve measurement compatibility: it represents the equivalence of a series of outcomes for reference materials and samples being analyzed when a few measurement procedures are employed, enabling objective comparisons between quantitative findings obtained through various experiments. The number of copies value represents a measured result of approximately 1.6 × 10⁵ copies/μL. The RM has about an 11% bottle-to-bottle homogeneity and shows stable results for 1 week at temperatures of 4 °C and −20 °C and for 12 months at a temperature of −80 °C. The developed RM can enhance the dependability of RV molecular tests by providing a precise reference value for the absolute copy number of a viral target gene. Additionally, it can serve as a reference for diverse studies. Full article

Type I and III interferons are among the most important antiviral mediators. Increased susceptibility to infections has been described as being associated with impaired interferon response in asthmatic patients. In this work, we focused on the modulation of interferon dysfunction after the rhinovirus infection of airway epithelial cells. Therefore, we tested polyinosinic:polycytidylic acid (poly I:C), a TLR3 agonist, as a possible preventive pre-treatment to improve this anti-viral response. In our human study on asthma, we found a deficiency in interferon levels in the nasal epithelial cells (NEC) from asthmatics at homeostatic level and after RV infection, which might contribute to frequent airway infection seen in asthmatic patients compared to healthy controls. Finally, pre-treatment with the immunomodulatory substance poly I:C before RV infection restored IFN responses in airway epithelial cells. Altogether, we consider poly I:C pre-treatment as a promising strategy for the induction of interferon response prior to viral infections. These results might help to improve current therapeutic strategies for allergic asthma exacerbations. Full article

Introduction: The need for effective therapeutic regimens for non-critically ill patients during the COVID-19 pandemic remained largely unmet. Previous work has shown that a combination of three aromatic plants’ essential oils (CAPeo) (Thymbra capitata (L.) Cav., Origanum dictamnus L., Salvia fruticose Mill.) has remarkable in vitro antiviral activity. Given its properties, it was urgent to explore its potential in treating mild COVID-19 patients in primary care settings. Methods: A total of 69 adult patients were included in a clinical proof-of-concept (PoC) intervention study. Family physicians implemented the observational study in two arms (intervention group and control group) during three study periods (IG_{2020, n=13}, IG_{2021/22, n=25}, and CG_{2021/22, n=31}). The SARS-CoV-2 infection was confirmed by real-time PCR. The CAPeo mixture was administered daily for 14 days per os in the intervention group, while the control group received usual care. Results: The PoC study found that the number and frequency of general symptoms, including general fatigue, weakness, fever, and myalgia, decreased following CAPeo administration. By Day 7, the average presence (number) of symptoms decreased in comparison with Day 1 in IG (4.7 to 1.4) as well as in CG (4.0 to 3.1), representing a significant decrease in the cumulative presence in IC (−3.3 vs. −0.9, p < 0.001; η² = 0.20) on Day 7 and on Day 14 (−4.2 vs. −2.9, p = 0.027; η² = 0.08). Discussion/Conclusions: Our findings suggest that CAPeo possesses potent antiviral activity against SARS-CoV-2 in addition tο its effect against influenza A and B and human rhinovirus HRV14 strains. The early and effective impact on alleviating key symptoms of COVID-19 may suggest this mixture can act as a complementary natural agent for patients with mild COVID-19. Full article

The recent global emergence of the SARS-CoV-2 pandemic has accelerated research in several areas of science whose valuable outputs and findings can help to address future health challenges in the event of emerging infectious agents. We conducted a comprehensive shotgun analysis targeting multiple aspects to compare differences in bacterial spectrum and viral presence through culture-independent RNA sequencing. We conducted a comparative analysis of the microbiome between healthy individuals and those with varying degrees of COVID-19 severity, including a total of 151 participants. Our findings revealed a noteworthy increase in microbial species diversity among patients with COVID-19, irrespective of disease severity. Specifically, our analysis revealed a significant difference in the abundance of bacterial phyla between healthy individuals and those infected with COVID-19. We found that Actinobacteria, among other bacterial phyla, showed a notably higher abundance in healthy individuals compared to infected individuals. Conversely, Bacteroides showed a lower abundance in the latter group. Infected people, regardless of severity and symptoms, have the same proportional representation of Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Fusobacteriales. In addition to SARS-CoV-2 and numerous phage groups, we identified sequences of clinically significant viruses such as Human Herpes Virus 1, Human Mastadenovirus D, and Rhinovirus A in several samples. Analyses were performed retrospectively, therefore, in the case of SARS-CoV-2 various WHO variants such as Alpha (B.1.1.7), Delta (B.1.617.2), Omicron (B.1.1.529), and 20C strains are represented. Additionally, the presence of specific virus strains has a certain effect on the distribution of individual microbial taxa. Full article