Evolutionary mechanisms involved in the virulence of infectious salmon anaemia virus (ISAV), a piscine orthomyxovirus

AbstractInfectious salmon anaemia virus (ISAV) is an orthomyxovirus causing a multisystemic, emerging disease in Atlantic salmon. Here we present, for the first time, detailed sequence analyses of the full-genome sequence of a presumed avirulent isolate displaying a full-length hemagglutinin-esterase (HE) gene (HPR0), and compare this with full-genome sequences of 11 Norwegian ISAV isolates from clinically diseased fish. These analyses revealed the presence of a virulence marker right upstream of the putative cleavage site R267 in the fusion (F) protein, suggesting a Q266→L266 substitution to be a prerequisite for virulence. To gain virulence in isolates lacking this substitution, a sequence insertion near the cleavage site seems to be required. This strongly suggests the involvement of a protease recognition pattern at the cleavage site of the fusion protein as a determinant of virulence, as seen in highly pathogenic influenza A virus H5 or H7 and the paramyxovirus Newcastle disease virus

Prevalence and subtypes of Influenza A Viruses in Wild Waterfowl in Norway 2006-2007

The prevalence of influenza A virus infection, and the distribution of different subtypes of the virus, were studied in 1529 ducks and 1213 gulls shot during ordinary hunting from August to December in two consecutive years, 2006 and 2007, in Norway. The study was based on molecular screening of cloacal and tracheal swabs, using a pan-influenza A RT-PCR. Samples found to be positive for influenza A virus were screened for the H5 subtype, using a H5 specific RT-PCR, and, if negative, further subtyped by a RT-PCR for the 3'-part of the hemagglutinin (HA) gene, encompassing almost the entire HA2, and the full-length of the neuraminidase (NA) gene, followed by sequencing and characterization. The highest prevalence (12.8%) of infection was found in dabbling ducks (Eurasian Wigeon, Common Teal and Mallard). Diving ducks (Common Goldeneye, Common Merganser, Red-breasted Merganser, Common Scoter, Common Eider and Tufted Duck) showed a lower prevalence (4.1%). In gulls (Common Gull, Herring Gull, Black-headed Gull, Lesser Black-headed Gull, Great Black-backed Gull and Kittiwake) the prevalence of influenza A virus was 6.1%. The infection prevalence peaked during October for ducks, and October/November for gulls. From the 16 hemagglutinin subtypes known to infect wild birds, 13 were detected in this study. Low pathogenic H5 was found in 17 dabbling ducks and one gull

Gut bacteria at 6 months of age are associated with immune cell status in 1-year-old children

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Fetal thoracic circumference and lung volume and their rlation to fetal size and pulmonary artery blood flow

Objective: Research on early origins of lung disease suggests the need for studying the relationships of thoracic and lung size with fetal size and pulmonary circulation. The primary aim of this study is therefore to explore the associations between fetal thoracic circumference, lung volume, and fetal size. We also aim to assess if lung volume and thoracic circumference are associated with fetal pulmonary artery blood flow velocity measures. Methods: Cross-sectional assessment of singleton pregnancies from the general population (n = 447) at 30 gestational weeks (GW) was performed using ultrasound measurement of fetal thoracic circumference, lung volume, head and abdominal circumference, and femur length. We obtained Doppler blood flow velocity measures from the proximal branches of the fetal pulmonary artery. Associations between variables were studied using Pearson's correlation and multiple linear regression analyses. Results: Both thoracic circumference and lung volume correlated with fetal size measures, ranging from r = 0.64 between thoracic circumference and abdominal circumference, to r = 0.28 between lung volume and femur length. Adjustment for gestational age, maternal nicotine use, pre-pregnancy body mass index, and fetal sex marginally influenced the associations with abdominal circumference. The correlations of thoracic circumference and lung volume with pulmonary artery blood flow velocity measures were weak (r ≤ 0.17). Conclusion: We found moderate to low correlation between thoracic circumference, lung volume, and fetal size at 30 GW. The closest relationship was with the abdominal circumference. We found low correlations of thoracic circumference and lung volume with pulmonary artery blood flow velocity measures.publishedVersio

Sars-cov-2 viremia is associated with inflammatory, but not cardiovascular biomarkers, in patients hospitalized for covid-19

Background COVID‐19 may present with a variety of cardiovascular manifestations, and elevations of biomarkers reflecting myocardial injury and stress are prevalent. SARS‐CoV‐2 has been found in cardiac tissue, and myocardial dysfunction post‐COVID‐19 may occur. However, the association between SARS‐CoV‐2 RNA in plasma and cardiovascular biomarkers remains unknown. Methods and Results COVID MECH (COVID‐19 Mechanisms) was a prospective, observational study enrolling consecutive, hospitalized patients with laboratory‐confirmed infection with SARS‐CoV‐2 and symptoms of COVID‐19. Biobank plasma samples used to measure SARS‐CoV‐2 RNA and cardiovascular and inflammatory biomarkers were collected in 123 patients at baseline, and in 96 patients (78%) at day 3. Patients were aged 60±15 (mean ± SD) years, 71 (58%) were men, 68 (55%) were White, and 31 (25%) received mechanical ventilation during hospitalization. SARS‐CoV‐2 RNA was detected in plasma from 48 (39%) patients at baseline. Patients with viremia were more frequently men, had more diabetes mellitus, and lower oxygen saturation. Patients with viremia had higher concentrations of interleukin‐6, C‐reactive protein, procalcitonin, and ferritin (all <0.001), but comparable levels of cTnT (cardiac troponin T; P=0.09), NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide; P=0.27) and D‐dimer (P=0.67) to patients without viremia. SARS‐CoV‐2 RNA was present in plasma at either baseline or day 3 in 50 (52%) patients, and these patients experienced increase from baseline to day 3 in NT‐proBNP and D‐dimer concentrations, while there was no change in cTnT. Conclusions SARS‐CoV‐2 viremia was associated with increased concentrations of inflammatory, but not cardiovascular biomarkers. NT‐proBNP and D‐dimer, but not cTnT, increased from baseline to day 3 in patients with viremia. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04314232