Rhiza Labs FluTracker Forum

From PF11 Blog

2009-12-04

Spain Introduces 2 November Sequences with Cross-Segment Pairing from Fatal Cases in the Ukraine

The HA and NA cross segment pairing of silent polymorphisms noted on the four fatal 225G cases from the Ukraine has now been tracked to 29 sequences around the globe on a cumulative study showing a quantifiable density in Spain.

• HA:syn413K encoded from A1281G, AAa->AAg *
• NA:syn407V encoded from T1221C, GTt->GTc *

* SNP Matches the 4 fatal flashfire cases

The most recent public database entries at GenBank are from Spain and were sampled in November 2009.

• HA and NA CatNS7362 TamiFlu Resistant
• HA and NA CatS1827

This background appears to be fertile ground and receptive to both major polymorphisms of interest today:

• HA 225G correlated with deep lung damage and one "low reactor" vaccine antisera challenge result
• NA 275Y conferring TamiFlu Resistance

The depth of this background continues to increase with 2 TamiFlu Resistant strains reported in 2 days. The persistance of this cross segment correlation may signal a viral genetic acquisition response to widespread TamiFlu usage. These silent polymorphisms are suggestive of an intermediate stage that is moving in the direction of antiviral resistance and continued Receptor Binding Domain revisions due to antiviral blanketing.

http://pf11.blogspot.com/2009/11/norway ... oding.html

2009-11-30
Norway Provides Distinct 225G Coding from Lung in September Male Fatality
A/Norway/3206-3 HA and NA, sampled on 2009-09-01 from the post-mortem lung of a male fatality imports a new 225G to Norway.

Only CatNS2001 and CatNS2008 from early August carry this variant Glycine coding at amino acid 225 that is seen as T717A, GGt->GGa. Neither of the cross segment pair, HA syn413K or NA syn407V, appears in this sample. Norway3206 carries a second HA polymorphism at 140S, a change found only 3 times within the reservoir, but found elsewhere in 1918 specimens, H5N1 Avian, Seasonal 2007, 2008, 2009 and the red-winged tinamou from 2008.

The Norway NA shows one residue of interest at syn291V, a change that is found in 102 sequences including TamiFlu Resistant HK2369, Almati01, Tomsk01, Poland and with deep penetration through Italy and Catalonia.

Two different codings for Glycine at residue 225 at this early stage of the pandemic demonstrates an ability within ΣPF11 for an individual strain to adapt quickly.