G743A in Kuwait H5N1
Recombinomics Commentary 18:45
February 21, 2008
H5N1 sequences from Kuwait are being released at GenBank. These sequences, from all eight gene segments, are from isolates from the outbreak beginning in February, 2007. As described previously, these sequences are clade 2.2.3 and trace back to the wild bird outbreak at Uvs Lake in Mongolia in the summer of 2006. The outbreak was massive and on a par with the wild bird outbreak a year earlier at Qinghai Lake.
This strain was subsequently detected in southern Korea at the end of 2006, which was followed by the outbreak in Kuwait. The releases sequences are closely related to the wild bird sequences subsequently detected in Germany and Krasnodar. Reports indicate similar sequences were also found in the Czech Republic and France in the summer, followed by outbreaks in England, Poland, northeastern Germany and Romania last year as well as an ongoing outbreak in Saudi Arabia.
The outbreak in Kuwait happened when NA G743A began to appear in isolates from Egypt and Moscow. The seven NA sequences from Kuwait also have G743A, raising the possibility that these Kuwait sequences were donors for the G743A acquisitions in Egypt. These sequences could also serve as precursors for the sequences which were subsequently detected in Europe. All closely related sequences from 2007 isolates in Europe also have G743A. However, the polymorphism has also been added to other genetic backgrounds in western Africa in Ghana and Nigeria.
This concurrent acquisition of G743A onto multiple genetic backgrounds is most easily explain by homologous recombination. Explaining these acquisitions by adaptive mutations would be difficult.
A/chicken/Kuwait/KISR2/2007
A/chicken/Kuwait/KISR3/2007
A/chicken/Kuwait/KISR5/2007
A/chicken/Kuwait/KISR6/2007
A/chicken/Kuwait/KISR7/2007
A/chicken/Kuwait/KISR8/2007
A/chicken/Kuwait/KISR9/2007
Media Links
Recombinomics Presentations
Recombinomics Publications
Recombinomics Paper at Nature Precedings