Detection of influenza and non-influenza respiratory viruses in lower respiratory tract specimens among hospitalized adult patients and analysis of the clinical outcome

Antiviral Properties of Moringa oleifera Leaf Extracts against Respiratory Viruses

Moringa oleifera (M. oleifera) is a plant widely used for its beneficial properties both in medical and non-medical fields. Because they produce bioactive metabolites, plants are a major resource for drug discovery. In this study, two different cultivars of leaves of M. oleifera (Salento and Barletta) were obtained by maceration or microwave-assisted extraction (MAE). We demonstrated that extracts obtained by MAE exhibited a lower cytotoxic profile compared to those obtained by maceration at concentrations ranged from 25 to 400 µg/mL, on both Vero CCL-81 and Vero/SLAM cells. We examined their antiviral properties against two viruses, i.e., the human coronavirus 229E (HCoV-229E) and measles virus (MeV), which are both responsible for respiratory infections. The extracts were able to inhibit the infection of both viruses and strongly prevented their attack and entry into the cells in a range of concentrations from 50 to 12 µg/mL. Particularly active was the variety of Salento that registered a 50% inhibitory concentration (IC50) at 21 µg/mL for HCoV-229E and at 6 µg/mL for MeV. We identified the presence of several compounds through high performance liquid chromatography (HPLC); in particular, chlorogenic and neochlorogenic acids, quercetin 3-O-β-d-glucopyranoside (QGP), and glucomoringin (GM) were mainly observed. In the end, M. oleifera can be considered a promising candidate for combating viral infections with a very strong action in the early stages of viral life cycle, probably by destructuring the viral particles blocking the virus-cell fusion.

Influenza A virus replicates productively in primary human kidney cells and induces factors and mechanisms related to regulated cell death and renal pathology observed in virus-infected patients

Introduction

Influenza A virus (IAV) infection can cause the often-lethal acute respiratory distress syndrome (ARDS) of the lung. Concomitantly, acute kidney injury (AKI) is frequently noticed during IAV infection, correlating with an increased mortality. The aim of this study was to elucidate the interaction of IAV with human kidney cells and, thereby, to assess the mechanisms underlying IAV-mediated AKI.

Methods

To investigate IAV effects on nephron cells we performed infectivity assays with human IAV, as well as with human isolates of either low or highly pathogenic avian IAV. Also, transcriptome and proteome analysis of IAV-infected primary human distal tubular kidney cells (DTC) was performed. Furthermore, the DTC transcriptome was compared to existing transcriptomic data from IAV-infected lung and trachea cells.

Results

We demonstrate productive replication of all tested IAV strains on primary and immortalized nephron cells. Comparison of our transcriptome and proteome analysis of H1N1-type IAV-infected human primary distal tubular cells (DTC) with existing data from H1N1-type IAV-infected lung and primary trachea cells revealed enrichment of specific factors responsible for regulated cell death in primary DTC, which could be targeted by specific inhibitors.

Discussion

IAV not only infects, but also productively replicates on different human nephron cells. Importantly, multi-omics analysis revealed regulated cell death as potential contributing factor for the clinically observed kidney pathology in influenza.

Prognostic factors of virus-associated pneumonia other than COVID-19 in adults

OBJECTIVE

To determine prognostic factors of virus-associated pneumonia other than coronavirus disease 2019.

METHODS

We retrospectively studied patients suffering from virus-associated community-acquired pneumonia, and who were admitted to Saitama Cardiovascular and Respiratory Center from 2002 to 2020. Prognostic factors were analyzed by univariable and multivariable regression analysis of patient demographics, laboratory data, chest imaging, severity on admission, and initial treatment.

PATIENTS

HIV-positive patients, those with non-resected lung cancer or receiving chemotherapy, and those with COVID-19 were excluded. Included were 363 patients diagnosed by nucleic acid amplification method, paired sera, and rapid diagnostic tests.

RESULTS

A CURB-65 score of ≥3 was significant by univariable analysis for 60-day mortality but was nonsignificant by multivariable analysis. The poor prognostic factors that were significant by multivariable analysis (p < 0.05) included immunosuppressive state due to systemic corticosteroid or immunosuppressant administration, acute kidney injury on admission, and corticosteroid administration initiated within 5 days or 5 days to 2 weeks from onset.

CONCLUSION

A CURB-65 score of ≥3, which is considered to indicate severe pneumonia, was of limited value for predicting mortality of virus-associated pneumonia. We showed patients' underlying diseases and complications to be independent factors of poor prognosis for 60-day mortality. Timing of the initiation of corticosteroid administration remains to be elucidated.

Influenza A and B Viruses in Fine Aerosols of Exhaled Breath Samples from Patients in Tropical Singapore

Influenza is a highly contagious respiratory illness that commonly causes outbreaks among human communities. Details about the exact nature of the droplets produced by human respiratory activities such as breathing, and their potential to carry and transmit influenza A and B viruses is still not fully understood. The objective of our study was to characterize and quantify influenza viral shedding in exhaled aerosols from natural patient breath, and to determine their viral infectivity among participants in a university cohort in tropical Singapore. Using the Gesundheit-II exhaled breath sampling apparatus, samples of exhaled breath of two aerosol size fractions ("coarse" > 5 µm and "fine" ≤ 5 µm) were collected and analyzed from 31 study participants, i.e., 24 with influenza A (including H1N1 and H3N2 subtypes) and 7 with influenza B (including Victoria and Yamagata lineages). Influenza viral copy number was quantified using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Infectivity of influenza virus in the fine particle fraction was determined by culturing in Madin-Darby canine kidney cells. Exhaled influenza virus RNA generation rates ranged from 9 to 1.67 × 105 and 10 to 1.24 × 104 influenza virus RNA copies per minute for the fine and coarse aerosol fractions, respectively. Compared to the coarse aerosol fractions, influenza A and B viruses were detected more frequently in the fine aerosol fractions that harbored 12-fold higher viral loads. Culturable virus was recovered from the fine aerosol fractions from 9 of the 31 subjects (29%). These findings constitute additional evidence to reiterate the important role of fine aerosols in influenza transmission and provide a baseline range of influenza virus RNA generation rates.

Outcomes of corticosteroid treatment in critical Ill adult patients with respiratory viruses-related community acquired pneumonia - a propensity-matched case control study

OBJECTIVES

To assess the outcomes of corticosteroid treatment in critically ill patients with respiratory virus-related community-acquired pneumonia (CAP).

MATERIALS/METHODS

Adult patients who were admitted to the intensive care unit and had a polymerase chain reaction-confirmed diagnosis of respiratory virus-related CAP were included. Patients with and without corticosteroid treatment during the hospital course were retrospectively compared using a propensity score-matched case-control analysis.

RESULTS

From January 2018 to December 2020, 194 adult patients were enrolled with 1:1 matching. The 14-day and 28-day mortality rates did not differ significantly between patients treated with and without corticosteroids (14-day mortality: 7% versus 14%, P = 0.11; 28-day mortality: 15% versus 20%, P = 0.35). However, multivariate analysis by using a Cox regression model revealed that corticosteroid treatment was an independent factor predicting decreased mortality (adjusted odds ratio, 0.46; 95% confidence interval, 0.22-0.97, P = 0.04). Subgroup analysis revealed lower 14-day and 28-day mortality rates in patients younger than 70 years treated with corticosteroids than in those not treated with corticosteroids (14-day mortality: 6% versus 23%; P = 0.01 and 28-day mortality: 12% versus 27%; P = 0.04).

CONCLUSIONS

Non-elderly patients with severe respiratory virus-related CAP are more likely to benefit from corticosteroid treatment than elderly patients.