Re: Confirmation of Avian Influenza H7N2 Infection
The most common recombination events end up with the acquisition of a short region (either because the acquisition is short, or the new portion is trimmed back to a small region). Any recombinant has to compete with the two parental strains, so large acquisitions may not be very competitive.
In the past I described the concurrent acquistion by a single nucleotide polymorphisms (the difference of one letter) onto multiple genetic backgrounds in Egypt, Russia, and Ghana. In each case the single nucleotide was appeneded onto the genetic background in the given region. This addition was on 11 sequences representing 6 H5N1 backgrounds.
The same thing happened with M230I. In one series, the sequencing encoding the M230I on the H5N1 in Egypt matched the sequence in H7N3, so the acquisition of M230I involve a single nucleotide and the the amino acid at position 230 changed from M to I.
It is this type of change that would convert H5N1 to a more efficient transmitter. In Egypt, there were 5 human isolates with M230I (4 had the coding seen in H5N1 in Germany, and 1 had the coding seen in H7N3 seen in England last year). There were also H5N1 poultry isolates with M230I. Most had the version seen in H7N3.
In addition to the efficient transmission in the Gharbiya cluster, all human cases with H5N1 containing M230I were fatal.
Originally posted by Niko
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In the past I described the concurrent acquistion by a single nucleotide polymorphisms (the difference of one letter) onto multiple genetic backgrounds in Egypt, Russia, and Ghana. In each case the single nucleotide was appeneded onto the genetic background in the given region. This addition was on 11 sequences representing 6 H5N1 backgrounds.
The same thing happened with M230I. In one series, the sequencing encoding the M230I on the H5N1 in Egypt matched the sequence in H7N3, so the acquisition of M230I involve a single nucleotide and the the amino acid at position 230 changed from M to I.
It is this type of change that would convert H5N1 to a more efficient transmitter. In Egypt, there were 5 human isolates with M230I (4 had the coding seen in H5N1 in Germany, and 1 had the coding seen in H7N3 seen in England last year). There were also H5N1 poultry isolates with M230I. Most had the version seen in H7N3.
In addition to the efficient transmission in the Gharbiya cluster, all human cases with H5N1 containing M230I were fatal.
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