resistance, page-9

2009-11-22

TamiFlu Resistance #13 from Italy: Novel with Swine Inclusion plus 4 Rare PF11 Amendments

The thirteenth TamiFlu Resistant specimen with a publicly available sequence, A/Pavia/21, was deposited Friday at GenBank with only Segment 6 (NA). The sample is contemporary and was taken 2009-11-16 on a nasal swab from a host with no gender or age identification in Pavia, a city of 71,000 in the Lombardy region of north central Italy. This Neuraminidase is remarkable due to the number and range of polymorphisms though the sequence is truncated 35 bases from the end.
Pavia21 is the most hypermorphic TamiFlu-Resistant PF11 strain seen since the oddities from the immuno-compromised patients in Washington. Four changes other than H275Y is unusual in a single sequence.

We are quite impressed with the Influenza reservoir's ability to recycle data between serotypes without reassortment. Unless this sample were exposed to low level radiation during incubation, a series of accumulative recombinations have occurred over a very short time period or a triple co-infection enlisted all variants to build Pavia21 within a single host using an adaptation event to smooth the topping.

The most probable explanation is an accumulation of recombinations across the hypermorphic Catalonia region then exporting data to Italy via wild birds with a single co-incident adaptation event within the eventual host. Additionally, our team would not be at all surprised to find 225E on the HA of this patient's virus if the data is eventually published.

At any measure, another new background is now carrying TamiFlu Resistance in a central flyway for Influenza's primary transportation vector, wild birds.