scholarly journals Influenza Virus Propagation in Embryonated Chicken Eggs

Author(s):  
Rena Brauer ◽  
Peter Chen
2020 ◽  
Vol 65 (3) ◽  
pp. 159-166
Author(s):  
V. A. Marchenko ◽  
S. V. Barashkova ◽  
I. A. Zelinskaya ◽  
Y. G. Toropova ◽  
E. V. Sorokin ◽  
...  

It has now been established that blood vessels are target for influenza, but the mechanism by which the influenza virus affects the cardiovascular system is unknown. The aim – adaptation of influenza virus A/St. Petersburg/48/16 H1N1(pdm09) to mature Wistar rats, as these animals are the main experimental model for studying the pathology of the cardiovascular system. Material and methods. Passage of influenza A virus (IAV) in embryonated chicken eggs, intranasal inoculation of rats with virus-containing material s, production of pulmonary homogenate, determination of IAV titer in embryonated chicken eggs, detection of histological changes in lung and pulmonary vessels. Results. The article presents the results of the adaptation of influenza virus A/St. Petersburg/48/16 H1N1(pdm09) to mature Wistar rats. The infectious titer of the virus in the homogenates of infected rats lungs at the last stage of adaptation was 7.0 lg EID50/ml. Histological studies revealed pronounced changes in the respiratory tract (spasm of bronchioles, submucosal edema, desquamation of ciliated epithelium of bronchioles) and pulmonary vessels (spasm, desquamation and swelling of endotheliocytes, dissociation and swelling of the elastic membrane and media). In order to identify IAV in blood vessels and lung tissues, an immunohistochemical study was performed using monoclonal antibodies to NP antigen of IAV. Conclusion. The data obtained allow us to conclude that the strain of influenza virus A/St. Petersburg/48/16 H1N1(pdm09) was adapted to mature Wistar rats maintaining virulent properties. The infectious titer of the virus at the last stage of adaptation was 7.0 lg EID50/ml. IAV identification is confirmed by immunohistochemical examination.


2017 ◽  
Vol 91 (23) ◽  
Author(s):  
Mahmoud M. Naguib ◽  
Reiner Ulrich ◽  
Elisa Kasbohm ◽  
Christine L. P. Eng ◽  
Donata Hoffmann ◽  
...  

ABSTRACT The cocirculation of zoonotic highly pathogenic avian influenza virus (HPAIV) of subtype H5N1 and avian influenza virus (AIV) of subtype H9N2 among poultry in Egypt for at least 6 years should render that country a hypothetical hot spot for the emergence of reassortant, phenotypically altered viruses, yet no reassortants have been detected in Egypt. The present investigations proved that reassortants of the Egyptian H5N1 clade 2.2.1.2 virus and H9N2 virus of the G1-B lineage can be generated by coamplification in embryonated chicken eggs. Reassortants were restricted to the H5N1 subtype and acquired between two and all six of the internal segments of the H9N2 virus. Five selected plaque-purified reassortant clones expressed a broad phenotypic spectrum both in vitro and in vivo. Two groups of reassortants were characterized to have retarded growth characteristics in vitro compared to the H5N1 parent virus. One clone provoked reduced mortality in inoculated chickens, although the characteristics of a highly pathogenic phenotype were retained. Enhanced zoonotic properties were not predicted for any of these clones, and this prediction was confirmed by ferret inoculation experiments: neither the H5N1 parent virus nor two selected clones induced severe clinical symptoms or were transmitted to sentinel ferrets by contact. While the emergence of reassortants of Egyptian HPAIV of subtype H5N1 with internal gene segments of cocirculating H9N2 viruses is possible in principle, the spread of such viruses is expected to be governed by their fitness to outcompete the parental viruses in the field. The eventual spread of attenuated phenotypes, however, would negatively impact syndrome surveillance on poultry farms and might foster enzootic virus circulation. IMPORTANCE Despite almost 6 years of the continuous cocirculation of highly pathogenic avian influenza virus H5N1 and avian influenza virus H9N2 in poultry in Egypt, no reassortants of the two subtypes have been reported. Here, the principal compatibility of the two subtypes is shown by forcing the reassortment between copassaged H5N1 und H9N2 viruses in embryonated chicken eggs. The resulting reassortant viruses displayed a wide range of pathogenicity including attenuated phenotypes in chickens, but did not show enhanced zoonotic propensities in the ferret model.


Author(s):  
Thongchai Taechowisan ◽  
Tipparat Samsawat ◽  
Chanjira Jaramornburapong ◽  
Weerachai Phutdhawong ◽  
Waya S. Phutdhawong

Aims: The purpose of this study was to synthesis novel amine-geldanamycin hybrids (AGH) and evaluate their biological properties. Study Design: Experimental study. Place and Duration of Study: The study was carried out at the Department of Microbiology and Department of Chemistry, Faculty of Science, Silpakorn University, from December 2019 - November 2020. Methodology: Three new amine-geldanamycin hybrids (AGH); compounds 2 to 4 were synthesised by nucleophilic substitution of geldanamycin (1). The solubility, cytotoxicity, antiviral activity and molecular docking analyses were carried out. Results: The solubility of AGH in water was 1.918-5.571 mM, higher than that of compound 1. Compound 2 exhibited weak cytotoxicity activity against Vero and LLC-MK2 cells, with IC50 values of 229.19 and 330.58 µg/ml, respectively. All compounds inhibited influenza virus propagation in embryonated chicken eggs at the lowest amount of 1.25 µg per egg. They interacted positively with Hsp90, showing a binding free energy (DG) of -112.00 to -116.34 kcal/mol, which indicated lower Hsp90 affinity compared with that of geldanamycin (-133.06 kcal/mol) and 17-dimethylamino ethylamino-17-demethoxygeldanamycin (-136.55 kcal/mol), despite being bound in the similar active site. For the viral absorption, only AGH inhibited hemagglutination at a concentration of 25 µg/ml. Conclusion: The study findings revealed, through molecular docking analysis, that the development of AGH improved the antiviral activity. The AGH inhibited not only influenza virus propagation, but also viral absorption. Therefore, AGH could be considered a new choice for antiviral agents.


2009 ◽  
Vol 84 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Zhongying Chen ◽  
Weijia Wang ◽  
Helen Zhou ◽  
Amorsolo L. Suguitan ◽  
Cindy Shambaugh ◽  
...  

ABSTRACT Several live attenuated influenza virus A/California/7/09 (H1N1) (CA09) candidate vaccine variants that possess the hemagglutinin (HA) and neuraminidase (NA) gene segments from the CA09 virus and six internal protein gene segments from the cold-adapted influenza virus A/Ann Arbor/6/60 (H2N2) virus were generated by reverse genetics. The reassortant viruses replicated relatively poorly in embryonated chicken eggs. To improve virus growth in eggs, reassortants expressing the HA and NA of CA09 were passaged in MDCK cells and variants exhibiting large-plaque morphology were isolated. These variants replicated at levels approximately 10-fold higher than the rate of replication of the parental strains in embryonated chicken eggs. Sequence analysis indicated that single amino acid changes at positions 119, 153, 154, and 186 were responsible for the improved growth properties in MDCK cells and eggs. In addition, the introduction of a mutation at residue 155 that was previously shown to enhance the replication of a 1976 swine influenza virus also significantly improved the replication of the CA09 virus in eggs. Each variant was further evaluated for receptor binding preference, antigenicity, attenuation phenotype, and immunogenicity. Mutations at residues 153, 154, and 155 drastically reduced viral antigenicity, which made these mutants unsuitable as vaccine candidates. However, changes at residues 119 and 186 did not affect virus antigenicity or immunogenicity, justifying their inclusion in live attenuated vaccine candidates to protect against the currently circulating 2009 swine origin H1N1 viruses.


2015 ◽  
Vol 28 (4) ◽  
pp. 192-200 ◽  
Author(s):  
Neda Barjesteh ◽  
Jennifer T. Brisbin ◽  
Shahriar Behboudi ◽  
Éva Nagy ◽  
Shayan Sharif

2008 ◽  
Vol 82 (10) ◽  
pp. 5079-5083 ◽  
Author(s):  
Jeffrey Meisner ◽  
Kristy J. Szretter ◽  
Konrad C. Bradley ◽  
William A. Langley ◽  
Zhu-Nan Li ◽  
...  

ABSTRACT The replicative properties of influenza virus hemagglutinin (HA) mutants with altered receptor binding characteristics were analyzed following intranasal inoculation of mice. Among the mutants examined was a virus containing a Y98F substitution at a conserved position in the receptor binding site that leads to a 20-fold reduction in binding. This mutant can replicate as well as wild-type (WT) virus in MDCK cells and in embryonated chicken eggs but is highly attenuated in mice, exhibiting titers in lungs more than 1,000-fold lower than those of the WT. The capacity of the Y98F mutant to induce antibody responses and the structural locations of HA reversion mutations are examined.


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