Influenza B virus (IBV) is more likely to cause complications than influenza A virus (IAV) and even causes higher disease burden than IAV in a certain season, but IBV has received less attention. In order to analyze the genetic evolution characteristics of the clinical strain IBV (B/Guangxi-Jiangzhou/1352/2018), we constructed genetic evolution trees and analyzed the homology and different amino acids of hemagglutinin and neuraminidase referring to the vaccine strains recommended by World Health Organization (WHO). We found that strain B/Guangxi-Jiangzhou/1352/2018 was free of interlineage reassortment and poorly matched with the vaccine strain B/Colorado/06/2017 of the same year. We also determined the median lethal dose (LD₅₀) and the pathogenicity of strain B/Guangxi-Jiangzhou/1352/2018 in mice. The results showed that the LD₅₀ was 10^5.9 TCID₅₀ (median tissue culture infective dose), the IBV titer in the lungs reached peak 1 d post infection and the mRNA level of the most of inflammatory cytokines in the lungs reached peak 12 h post infection. The alveoli in the lungs were severely damaged and a large number of inflammatory cells were infiltrated post infection. The study demonstrated that the clinical strain IBV (B/Guangxi-Jiangzhou/1352/2018) could infect mice and induce typical lung inflammation. This will facilitate the research on the pathogenesis and transmission mechanism of IBV, and provide an ideal animal model for evaluation of new vaccines, antiviral and anti-inflammatory drug.
Amino Acids/genetics* ; Animals ; Antiviral Agents/pharmacology* ; China ; Cytokines/metabolism* ; Hemagglutinins/metabolism* ; Humans ; Influenza B virus/pathogenicity* ; Influenza, Human/virology* ; Mice ; Neuraminidase/genetics* ; Orthomyxoviridae Infections/virology* ; Phylogeny ; RNA, Messenger/metabolism* ; Virulence/genetics*

OBJECTIVE: To perform a systematic review to assess the effectiveness and safety of Reduning Injection versus neuraminidase inhibitors in treatment of influenza. METHODS: The MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), Chinese Bio-medical Literature and Retrieval System (Sinomed), China National Knowledge Infrastructure Database (CNKI), China Science and Technology Journal Database (VIP), Wanfang Data Knowledge Service Platform and ClinicalTrails.gov were systematically searched from inception dates to May 2021 for randomized controlled trials (RCTs) exploring Reduning Injection alone or in combination with neuraminidase inhibitors in patients with influenza. Statistical analysis was performed using RevMan 5.4 and Stata 15.1. The qualities of the involved studies were assessed by the risk of bias according to the Cochrane handbook. The evidence quality of each outcome was evaluated by GRADEpro GDT. RESULTS: Twelve trials with 1,460 patients were included. The included studies had a certain unclear or high risk of bias. Reduning Injection appeared to be more effective in shortening the fever clearance time (MD: -16.20 h, 95% CI: -19.40 to -12.99, 7 trials, 814 patients, I²=94%, very low certainty), fever alleviation time (MD: -4.09 h, 95% CI: -4.22 to -3.96, 3 trials, 366 patients, I²=0%, low certainty), cough alleviation time (MD: -21.34 h, 95% CI: -41.56 to -1.11, 2 trials, 228 patients, I²=89%, very low certainty), fatigue alleviation time (MD: -31.83 h, 95% CI: -36.88 to -26.77, 2 trials, 270 patients, I²=0%, low certainty), sore throat alleviation time (MD: -28.66 h, 95% CI: -32.23 to -25.10, 1 trial, 150 patients, low certainty), and improving the total effective rate (RR: 1.15, 95% CI: 1.06 to 1.25, 10 trials, 1,074 patients, I²=76%, very low certainty). Besides, Reduning Injection seemed generally safe. CONCLUSIONS This study provided low or very low evidence indicating Reduning Injection may be effective in the treatment of influenza and might be safe. Further rigorously designed studies are needed to confirm the effectiveness and safety of Reduning Injection and support it as a recommendation for influenza.
Humans ; Neuraminidase ; Influenza, Human/drug therapy* ; Drugs, Chinese Herbal ; Antiviral Agents

The purpose was to discuss the infection status of human parainfluenza virus type 3 (HPIV-3) in children with acute respiratory tract infection(ARTI) in Qingdao, Shandong province, and to analyze the gene characteristics of HPIV-3 hemagglutinin-neuraminidase protein (HN). This study was a cross-sectional study. A total of 1 674 throat swab samples were collected randomly from children with ARTI, in the three hospitals (Qingdao Women and Children's Hospital, West Coast Branch of Affiliated Hospital of Qingdao University, Laoshan Branch of Affiliated Hospital of Qingdao University) from January 2018 to December 2019. Multiplex real-time fluorescence RT-PCR was performed to screen HPIV-3 positive specimens. For HPIV-3 positive specimens, nested PCR was used to amplify the full-length HN gene of HPIV-3. The HN gene was sequenced and compared with the representative strains of HPIV-3 in GenBank, and the phylogenetic tree was established. As results, this study collected 1 674 samples, in which there were 90 HPIV-3 positive samples showed and the detection rate was 5.37%. Among positive specimens, the number of samples from children under 6 years old was 88, accounting for 97.78%. HPIV-3 positive cases were mainly distributed in spring and summer. The full-length sequences of 44 HPIV-3 HN genes were obtained by nested PCR method. Sequence alignment and evolutionary analysis showed that the HPIV-3HN gene belonged to the C3a and C3b branches of C3 genotype, with 30 strains of subtype C3a and 14 strains of subtype C3b. The nucleotide and amino acid homology of the amplified 44 strains of the HPIV-3 HN gene in Qingdao were 97.0%-100.0% and 98.5%-100.0%, respectively. In conclusion, from 2018 to 2019, the C3a and C3b branches of HPIV-3 C3 genotype were circulating prevalent in Qingdao, Shandong province. HN gene variation rate was low, but showed certain regional characteristics in evolution.
Child ; Child, Preschool ; Cross-Sectional Studies ; Female ; Hemagglutinins ; Humans ; Neuraminidase ; Parainfluenza Virus 3, Human/genetics* ; Phylogeny ; Respiratory Tract Infections/epidemiology* ; Viral Proteins

neuraminidase, no antigenic mutation was observed throughout all passages when cultured in MDCK-Sky3851 cells. On the other hand, mutations occurred in three amino acid sequences (H156R, G186S, S219F) in hemagglutinin up to 15 passages when cultured in eggs.CONCLUSION: H3N2 influenza virus cultured in eggs could lead mutations in amino acid sequence of hemagglutinin, distinct from the corresponding virus cultured in cells for which no antigenic mutation was observed. These findings suggest that cell culture is a more stable and effective way of production with lower risk of antigenic mutations for the manufacture of influenza vaccines.]]>
Amino Acid Sequence ; Animals ; Cell Culture Techniques ; Cell Line ; Chickens ; Eggs ; Erythrocytes ; Guinea Pigs ; Hand ; Hemagglutination ; Hemagglutinins ; Humans ; Influenza Vaccines ; Influenza, Human ; Neuraminidase ; Orthomyxoviridae ; Ovum ; Sequence Analysis ; Specific Pathogen-Free Organisms

neuraminidase. Additionally, the HA assay results showed a significant positive correlation with the infectious viral titer. Our results suggest that assessing the HA activity of PDCoV may be a useful diagnostic method for investigating and surveilling PDCoV infections.]]>
Coronavirus ; Diarrhea ; Erythrocytes ; Hemagglutination ; Methods ; Neuraminidase ; Population Characteristics ; Swine ; Trypsin ; Virion

Neuraminidase (NA) cleaves the glycosidic bond linkages of sialic acids to release the mature virions from infected cells and has been an attractive therapeutic target for anti-influenza agents. In our ongoing investigation of NA inhibitors in mushroom extracts, we found that the extract the fruiting body of Glaziella splendens potently inhibited neuraminidase. The fruiting bodies of G. splendens were extracted and partitioned successively with hexane, ethyl acetate, and butanol. The ethyl acetate soluble-layer was subjected to silica gel and Sephadex LH-20 column chromatographies, and MPLC to obtain five compounds (1–5). Their structures were determined by spectroscopic methods. NA inhibitory activity of these compounds was evaluated using NAs from recombinant rvH1N1, H3N2, and H5N1 influenza A viruses. One compound (1) was elucidated as a new azaphilone derivative, and four compounds (2–5) were identified as entonaemin A, comazaphilone D, rubiginosin A, and entonaemin B, respectively. Compounds 3 and 4 showed considerable inhibitory activity against three types of neuraminidases with the IC₅₀ values of 30.9, 41.8, and 35.7 µM for 3 and 46.5, 50.4, and 29.9 µM for 4, respectively. This study reveals that the fruiting bodies of G. splendens possess azaphilone derivatives with the NA inhibitory activity. This is the first report on the isolation of neuraminidase inhibitors from the fruiting bodies of G. splendens.
Agaricales ; Chromatography ; Fruit ; Influenza A virus ; N-Acetylneuraminic Acid ; Neuraminidase ; Sialic Acids ; Silica Gel ; Virion

The subtype H9N2 avian influenza virus greatly threatens the Chinese poultry industry, even with annual vaccination. Waterfowl can be asymptomatically infected with the H9N2 virus. In this study, three H9N2 virus strains, designated A/Goose/Jiangsu/YZ527/2011 (H9N2, Gs/JS/YZ527/11), A/Goose/Jiangsu/SQ119/2012 (H9N2, Gs/JS/SQ119/12), and A/Goose/Jiangsu/JD564/2012 (H9N2, Gs/JS/JD564/12), were isolated from domestic geese. Molecular characterization of the three isolates showed that the Gs/JS/YZ527/11 virus is a double-reassortant virus, combining genes of A/Quail/Hong Kong/G1/97 (H9N2, G1/97)-like and A/Chicken/Shanghai/F/98 (H9N2, F/98)-like; the Gs/JS/SQ119/12 virus is a triple-reassortant virus combining genes of G1/97-like, F/98-like, and A/Duck/Shantou/163/2004 (H9N2, ST/163/04)-like. The sequences of Gs/JS/JD564/12 share high homology with those of the F/98 virus, except for the neuraminidase gene, whereas the internal genes of Gs/JS/YZ527/11 and Gs/JS/SQ119/12 are closely related to those of the H7N9 viruses. An infectivity analysis of the three isolates showed that Gs/JS/SQ119/12 and Gs/JS/YZ527/11 replicated well, with seroconversion, in geese and chickens, the Gs/JS/JD564/12 did not infect well in geese or chickens, and the F/98 virus only infected chickens, with seroconversion. Emergence of these new reassortant H9N2 avian influenza viruses indicates that these viruses can infect both chicken and goose and can produce different types of lesions in each species.
Animals ; Asian Continental Ancestry Group ; Chickens ; Geese ; Humans ; Influenza A Virus, H7N9 Subtype ; Influenza A Virus, H9N2 Subtype ; Influenza in Birds ; Neuraminidase ; Population Characteristics ; Poultry ; Sequence Analysis ; Seroconversion ; Vaccination

BACKGROUND/AIMS: Due to advances in diagnostic techniques, clinicians are more frequently performing influenza diagnostic tests and referring to their test results ahead of the administration of neuraminidase inhibitors (NAIs). To investigate the clinical significance of the time from symptom onset to laboratory diagnosis, we reviewed the clinical characteristics of adult patients with influenza who had an early laboratory diagnosis (ED) or a late laboratory diagnosis (LD) at one of four tertiary care centers during a seasonal outbreak of influenza. METHODS: Clinical data were collected from 1,405 adults during the 2013 to 2014 influenza season. A patient was regarded as receiving an ED or LD if he/she received an influenza diagnostic test at 0 to 1 or 4 to 7 days after symptom onset, respectively. Early NAI therapy and late NAI therapy were defined as the administration of NAI ≤ 2 or > 2 days after symptom onset, respectively. RESULTS: Nearly half of the patients (47.0%) received an ED (n = 661), whereas 13.5% (n = 190) received a LD. Patients with a LD had initial symptoms of cough, sputum production, and dyspnea and experienced pneumonia, antibiotic therapy, hospitalization, and admission to the intensive care unit more often than those with an ED. NAI therapy and early NAI therapy were less frequent in patients with a LD than those with an ED. Of the analyzed baseline characteristics, age ≥ 50 years, influenza B infection, and diagnosis using a polymerase chain reaction test were significantly associated with a LD. CONCLUSIONS: LD was associated with inappropriate antiviral therapy and complicated presenting features in adult patients with seasonal influenza. ED of influenza should be emphasized, especially for older adults.
Adult* ; Antiviral Agents ; Clinical Laboratory Techniques ; Cough ; Delayed Diagnosis* ; Diagnosis ; Diagnostic Tests, Routine ; Dyspnea ; Hospitalization ; Humans ; Influenza, Human* ; Intensive Care Units ; Neuraminidase ; Pneumonia ; Polymerase Chain Reaction ; Seasons* ; Sputum ; Tertiary Care Centers

Influenza is an acute respiratory disease caused by the influenza virus. Each year, it causes a significant disease burden, especially in older adults. Furthermore, influenza pandemics occasionally occur because of antigenic change. Common signs and symptoms of influenza include fever, cough, sore throat, headache, myalgia, and runny nose. Severe cases may progress to pneumonia, which causes shortness of breath, tachycardia, hypotension, and the need for supportive respiratory interventions. Mild cases are self-limited and supportive care is sufficient. Antiviral treatment shortens the clinical course if it is administered within 48 hours from the onset of disease. Neuraminidase inhibitors, such as oseltamivir, zanamivir, and peramivir, are widely used. Although annual vaccination is the best means of prevention, its effectiveness can vary from year to year and among different age and risk groups.
Adult ; Cough ; Dyspnea ; Fever ; Headache ; Humans ; Hypotension ; Influenza, Human ; Myalgia ; Neuraminidase ; Nose ; Orthomyxoviridae ; Oseltamivir ; Pandemics ; Pharyngitis ; Pneumonia ; Tachycardia ; Vaccination ; Zanamivir

Antiviral drugs on influenza are important in the control program of influenza. Options for influenza treatment are currently limited to using the neuraminidase inhibitors (NAIs). Given limited effectiveness of NAIs and related resistance, there remains an urgent need for the development of influenza antiviral drugs that can improve the efficacy and provide low propensity of viral resistance. Several influenza-related antiviral drugs that are currently under the late-stage clinical trials all appear differently in the mechanism of action. It is hoped that when new antiviral drugs are licensed, care and outcomes of severe influenza cases will be improved.
Antiviral Agents/therapeutic use* ; Drug Resistance, Viral ; Enzyme Inhibitors/therapeutic use* ; Humans ; Influenza, Human/drug therapy* ; Neuraminidase/therapeutic use*