Volume 17, Number 11—November 2011
Dispatch
Influenza B Viruses with Mutation in the Neuraminidase Active Site, North Carolina, USA, 2010–11
Table 2
Percentage composition of isoleucine and valine at position 221 in the neuraminidase of virus isolates and clinical specimens with reduced susceptibility to oseltamivir and peramivir, North Carolina, USA, 2010−11 influenza season*
Strain designation | Date of collection |
Clinical specimen
|
Virus isolate
| |||
---|---|---|---|---|---|---|
% Isoleucine | % Valine | % Isoleucine | % Valine | |||
B/North Carolina/02/2010 | 2010 Nov 10 | NA | NA | 20 | 80 | |
B/North Carolina/11/2010 | 2010 No 29 | 5 | 95 | 38 | 62 | |
B/North Carolina/06/2010 | 2010 Dec 6 | NA | NA | 15 | 85 | |
B/North Carolina/07/2010 | 2010 Dec 6 | NA | NA | 19 | 81 | |
B/North Carolina/08/2010 | 2010 Dec 7 | NA | NA | 24 | 76 | |
B/North Carolina/10/2010 | 2010 Dec 17 | 8 | 92 | 13 | 87 | |
B/North Carolina/12/2010 | 2010 Dec 20 | 9 | 91 | 15 | 85 | |
B/North Carolina/13/2010 | 2010 Dec 21 | 10 | 90 | 17 | 83 | |
B/North Carolina/03/2011 | 2011 Jan 5 | 38 | 62 | 36 | 64 | |
B/North Carolina/06/2011 | 2011 Jan 24 | 7 | 93 | 15 | 85 | |
B/North Carolina/01/2011 | 2011 Feb 1 | 11 | 89 | 13 | 87 | |
B/North Carolina/02/2011 | 2011 Feb 1 | 8 | 92 | 14 | 86 | |
B/North Carolina/07/2011 | 2011 Jan 31 | 8 | 92 | 15 | 85 | |
B/North Carolina/08/2011 | 2011 Feb 10 | F | F | 12 | 88 | |
B/Memphis/20/1996 | NA | NA | NA | 100 |
0
*NA, not available; F, failed in pyrosequencing analysis. 10% is the standard cutoff value for the presence of a single-nucleotide polymorphism because of limitations of the pyrosequencing assay. |
*NA, not available; F, failed in pyrosequencing analysis. 10% is the standard cutoff value for the presence of a single-nucleotide polymorphism because of limitations of the pyrosequencing assay.