Re: Avian Pathol. Molecular evolution of H5N1 highly pathogenic avian influenza viruses in Bangladesh between 2007 and 2012
Source: http://www.scidev.net/south-asia/hea...cientists.html
Mutant bird flu virus worry Bangladeshi scientists
28/04/14
Naimul Haq
Speed read
H5N1 virus found acquiring genes from other bird flu virus strains
Strains in circulation are different from the one that caused the 2007 bird flu outbreak
The bird flu virus is adapting to new winged hosts such as crow, quail and duck
[DHAKA] The highly 'pathogenic' or disease-causing bird flu virus 'H5N1' is continuously mutating and evolving in Bangladesh, necessitating stricter surveillance and biosecurity measures, new research reports caution.
A team of scientists from the Bangladesh Agricultural University (BAU), Mymensingh and the Bangladesh Livestock Research Institute (BLRI), Savar, who studied how H5N1 virus evolved at the molecular level since the country's first outbreak in 2007, report that newer strains have replaced the older ones.
The H5N1 virus acquired a crucial gene from a low disease-causing bird flu virus 'H9N2'; and accumulated single-point genetic changes that have the potential to modify the way the virus gets hinged to the host. The scientists have published details of their research in Avian Pathology and Preventive Veterinary Medicine this month...
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Avian Pathol. Molecular evolution of H5N1 highly pathogenic avian influenza viruses in Bangladesh between 2007 and 2012
[Source: Taylor and Francis Online, full page: (LINK). Abstract, edited.]
Avian Pathology, Volume 43, Issue 2, 2014
Molecular evolution of H5N1 highly pathogenic avian influenza viruses in Bangladesh between 2007 and 2012
DOI: 10.1080/03079457.2014.898244
M. E. Haque<SUP>a</SUP>, M. Giasuddin<SUP>b</SUP>, E. H. Chowdhury<SUP>a</SUP> & M. R. Islam<SUP>a</SUP><SUP>*</SUP>
<SUP></SUP>
pages 183-194
Received: 13 Oct 2013 - Accepted: 28 Jan 2014 - Published online: 01 Apr 2014
Abstract
In Bangladesh, highly pathogenic avian influenza (HPAI) virus subtype H5N1 was first detected in February 2007. Since then the virus has become entrenched in poultry farms of Bangladesh. There have so far been seven human cases of H5N1 HPAI infection in Bangladesh with one death. The objective of the present study was to investigate the molecular evolution of H5N1 HPAI viruses during 2007 to 2012. Partial or complete nucleotide sequences of all eight gene segments of two chicken isolates, five gene segments of a duck isolate and the haemagglutinin gene segment of 18 isolates from Bangladesh were established in the present study and subjected to molecular analysis. In addition, full-length sequences of different gene segments of other Bangladeshi H5N1 isolates available in GenBank were included in the analysis. The analysis revealed that the first introduction of clade 2.2 virus in Bangladesh in 2007 was followed by the introduction of clade 2.3.2.1 and 2.3.4 viruses in 2011. However, only clade 2.3.2.1 viruses could be isolated in 2012, indicating progressive replacement of clade 2.2 and 2.3.4 viruses. There has been an event of segment re-assortment between H5N1 and H9N2 viruses in Bangladesh, where H5N1 virus acquired the PB1 gene from a H9N2 virus. Point mutations have accumulated in Bangladeshi isolates over the last 5 years with potential modification of receptor binding site and antigenic sites. Extensive and continuous molecular epidemiological studies are necessary to monitor the evolution of circulating avian influenza viruses in Bangladesh.
Permalink: http://dx.doi.org/10.1080/03079457.2014.898244
Citation information: PubMed / Received: 13 Oct 2013 Accepted: 28 Jan 2014 Published online: 01 Apr 2014
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